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W8L4mLUrfXaxM0xy	Literature, Critical Thinking, & Writing	13 Assigned Reading: Chopin’s “The Story of an Hour” Knowing that Mrs. Mallard was afflicted with a heart trouble, great care was taken to break to her as gently as possible the news of her husband’s death. It was her sister Josephine who told her, in broken sentences; veiled hints that revealed in half concealing. Her husband’s friend Richards was there, too, near her. It was he who had been in the newspaper office when intelligence of the railroad disaster was received, with Brently Mallard’s name leading the list of “killed.” He had only taken the time to assure himself of its truth by a second telegram, and had hastened to forestall any less careful, less tender friend in bearing the sad message. She did not hear the story as many women have heard the same, with a paralyzed inability to accept its significance. She wept at once, with sudden, wild abandonment, in her sister’s arms. When the storm of grief had spent itself she went away to her room alone. She would have no one follow her. There stood, facing the open window, a comfortable, roomy armchair. Into this she sank, pressed down by a physical exhaustion that haunted her body and seemed to reach into her soul. She could see in the open square before her house the tops of trees that were all aquiver with the new spring life. The delicious breath of rain was in the air. In the street below a peddler was crying his wares. The notes of a distant song which some one was singing reached her faintly, and countless sparrows were twittering in the eaves. There were patches of blue sky showing here and there through the clouds that had met and piled one above the other in the west facing her window. She sat with her head thrown back upon the cushion of the chair, quite motionless, except when a sob came up into her throat and shook her, as a child who has cried itself to sleep continues to sob in its dreams. She was young, with a fair, calm face, whose lines bespoke repression and even a certain strength. But now there was a dull stare in her eyes, whose gaze was fixed away off yonder on one of those patches of blue sky. It was not a glance of reflection, but rather indicated a suspension of intelligent thought. There was something coming to her and she was waiting for it, fearfully. What was it? She did not know; it was too subtle and elusive to name. But she felt it, creeping out of the sky, reaching toward her through the sounds, the scents, the color that filled the air. Now her bosom rose and fell tumultuously. She was beginning to recognize this thing that was approaching to possess her, and she was striving to beat it back with her will—as powerless as her two white slender hands would have been. When she abandoned herself a little whispered word escaped her slightly parted lips. She said it over and over under her breath: “free, free, free!” The vacant stare and the look of terror that had followed it went from her eyes. They stayed keen and bright. Her pulses beat fast, and the coursing blood warmed and relaxed every inch of her body. She did not stop to ask if it were or were not a monstrous joy that held her. A clear and exalted perception enabled her to dismiss the suggestion as trivial. She knew that she would weep again when she saw the kind, tender hands folded in death; the face that had never looked save with love upon her, fixed and gray and dead. But she saw beyond that bitter moment a long procession of years to come that would belong to her absolutely. And she opened and spread her arms out to them in welcome. There would be no one to live for her during those coming years; she would live for herself. There would be no powerful will bending hers in that blind persistence with which men and women believe they have a right to impose a private will upon a fellowcreature. A kind intention or a cruel intention make the act seem no less a crime as she looked upon it in that brief moment of illumination. And yet she had loved him—sometimes. Often she had not. What did it matter! What could love, the unsolved mystery, count for in face of this possession of self-assertion which she suddenly recognized as the strongest impulse of her being! “Free! Body and soul free!” she kept whispering. Josephine was kneeling before the closed door with her lips to the keyhole, imploring for admission. “Louise, open the door! I beg; open the door—you will make yourself ill. What are you doing, Louise? For heaven’s sake open the door.” “Go away. I am not making myself ill.” No; she was drinking in a very elixir of life through that open window. Her fancy was running riot along those days ahead of her. Spring days, and summer days, and all sorts of days that would be her own. She breathed a quick prayer that life might be long. It was only yesterday she had thought with a shudder that life might be long. She arose at length and opened the door to her sister’s importunities. There was a feverish triumph in her eyes, and she carried herself unwittingly like a goddess of Victory. She clasped her sister’s waist, and together they descended the stairs. Richards stood waiting for them at the bottom. Some one was opening the front door with a latchkey. It was Brently Mallard who entered, a little travel-stained, composedly carrying his grip-sack and umbrella. He had been far from the scene of accident, and did not even know there had been one. He stood amazed at Josephine’s piercing cry; at Richards’ quick motion to screen him from the view of his wife. But Richards was too late. When the doctors came they said she had died of heart disease—of joy that kills.	1,322	common-pile/pressbooks_filtered	https://library.achievingthedream.org/westhillsccenglish1b/chapter/assigned-reading-chopins-the-story-of-an-hour/	pressbooks	pressbooks-0000.json.gz:22221	https://library.achievingthedream.org/westhillsccenglish1b/chapter/assigned-reading-chopins-the-story-of-an-hour/
nV-sjfLZO6cSayrd	On certain portions of the skeleton of Protostega gigas [by] O. P. Hay.	The Dermochelyoid turtle, Protostega gigas, was first described by Professor E. D. Cope in Proc. Amer. Phil. Soc., 1-871, page 172, and again in the same publication in 1872, page 403. In 1875, m n^s ''Cretaceous Vertebrata," pp. 99-113, pis. IX-XIII, the same writer more fully described and illustrated the structure of this remarkable reptile. The materials which were in Professor Cope's hands consisted of a number of vertebrae, ten ribs, some marginal bones, certain portions of the skull, some limb bones, and some large plates. Of the latter there were what the describer regarded as two entire and parts of one or two others. These plates he considered as belonging to the carapace, and this was supposed to be free from the ribs, as the peculiar carapace otDermochelys is free from the ribs of that turtle. In this conclusion he was undoubtedly wrong, as was later shown by Dr. G. Baur (Biolog. Central blatt, vol. 9, p. 190). This author pointed out that the plates were components of the plastron, an opinion that finds abundant confirmation in the materials here to be described. These consist of a large portion of the plastron of a large individual whose remains were entombed in the Cretaceous deposits of Butte Creek, Kansas. As shown in Plate IV, there are present the hyoplastron and the hypoplastron of the left side almost complete. There are also portions of the same bones belonging to the right side. These parts of the plastron were also accompanied by the nuchal. The length of _the hyoplastron and the hypoplastron taken together amounts to 1.2 metres, including the estimated length of a piece missing from near the hinder end of the hypoplastron. These two bones are united by suture, which may be seen immediately in front of the fracture produced in excavating the fossil. The relation of these two bones is therefore unmistakably indicated. The suture between the two bones is a very short one, in comparison with that The length of the hyoplastron is 6icm; its width 52.5 cm. The extreme width of the hypoplastron is somewhat less than that of the hyoplastron, but it cannot be accurately determined. The latter bone is thickest just behind and somewhat mesiad of the excavation for the fore limb, and here the thickness amounts to 45mm. The hypoplastron is not so thick, but still quite thick and solid. The corresponding bones in Professor Cope's possession were not more than half an inch in thickness, at the most. This condition was in all probability due to the pressure to which they had been subjected. As will be observed, the anterior inner angle of the hyoplastron is extensively developed, surpassing in this respect that of Thalassochelys, in which again the plastron is more developed than in Chelonia. As usual in all the recent marine turtles, this angle extends further forward than does the outer one. To that border of this angle which lies next to the fore limb was attached the hinder end of the epiplastron. Neither of the epiplastra was secured. In Thalassochelys the anterior ends of the epiplastra extend in front of a line joining the bottoms of the excavations for the fore limbs a distance equal to that from the bottom of the excavations for the fore limbs to those for the hind limbs. This, in the Protostega plastron before me, amounts to 84 cm. The xiphiplastra of Thalassochelys extend behind the excavations for the hinder limbs as far as do the epiplastra from the anterior excavations. If these proportions hold good for Protostega, the whole length of the plastron would amount to at least 2.4 metres. As shown by the figure, the hinder end of the hypoplastron is prolonged backward and somewhat inward as a long process. Mesiad of this process there has been another and, judging from the example of Chelonia and Thalassochelys, a longer process. A portion of this process is missing, but the bone, where the fracture has occurred is still 21 mm. thick. This missing process was also evidently directed somewhat toward the middle line of the body, as well as backward. Between the two processes has been received the forked end of the xiphiplastron of that side. The upper end of the inner border of the outer process has been chamfered off where it forms a suture with the xiphiplastron. This chamfering of the bone continues beyond the point of union of the two processes and is then carried backward on the inner process as far as this remains. The upper side of the outer border of the outer process has also entered into sutural union with the xiphiplastron. The whole structure is here extremely similar to that seen in Chelonia and Thalassochelys. Had the breadth of the body of Protostega possessed the same ratio to the length that we find existing in Thalassochelys, the lower side of the animal would have been about 2.2 metres wide. The positions of the surfaces for union with the epiplastra and xiphiplastra, and the location of the axis of strongest development of the two plastral bones of each side make it evident that the outer border of the bony plastron was at a considerable distance from the outer edge of the body. This is shown too by measuring outward from the excavation for the arm a distance proportional to that found in Thalassochelys. The tips of the digitations of the plastral bones must have lacked as much as 30 cm. of reaching the marginal bones. This will leave a space of about 120 cm. from the bottom of the excavation for one arm to that for the other. When we come to compare the distance from the hinder to the front excavations, in the restoration of Protosphargis by Capellini (Mem. Ac. dei Lincei, 1884, 3 ser., vol. 18), with the distance of the two anterior excavations apart, I find that the two measurements have almost exactly the same ratio that I have given them in Protostega. If we have placed the plastral bones aright, there is left between them a great fontanelle. Where the hyoplastra are widest this is about 43 cm. in width ; and opposite the union of the hyo- and hypoplastron, about 90 cm. This is somewhat smaller, however, than the fontanelle found in Protosphargis, and much smaller than that of Dermochelys. The nearest relative of Protostega is undoubtedly Protosphargis \ but when we come to compare the two plastra, we find abundant differences. That of Protosphargis is considerably less developed than that of Protostega. Notwithstanding this, there was on the front of the hyoplastron of Protosphargis a long slender process which ran forward and inward to connect with the epiplastron. In Protostega the corresponding angle of the hyoplastron is broad, rounded off, and digitated. In Protosphargis again there is a broad notch in the anterior and outer border of the hypoplastron, but none in Protostega. It appears to be quite evident that Capellini's restoration of Protosphargis is in one respect not wholly accurate. The epiplastra appear to be too short and to converge too rapidly, thus making the plastron too short. Accompanying the plastral bones here described is another bone which must he regarded as the nuchal. Considerable portions of it are wanting at each lateral extremity ; and the tip of the process which projects backward toward the first dorsal neural arch is also broken away. The portion of the bone remaining projects outward on each side of the middle line less than 18 cm. If the length of the bone had the same ratio to the remainder of the carapace of Protostega that we find in Chelonia, it should extend laterally about 40 cm. That it had this length so as to reach the first marginal, is quite probable. If the anterio-posterior extent of the bone were equal to that of Chclonia, it would be about 30 cm. at the narrowest part; but it is only 6 cm. Indeed, the portion remaining appears to represent little more than the median, backwardly projecting process and the anterior thickened border of the nuchal of Chelonia. The reduction in the anterio-posterior direction really appears to have gone further than in Dermochclys even. In the latter, however, the anterior border of the bone has been removed, so that it, as well as the other borders, are jagged and thin. In Protostega it is the hinder border of the bone which has been removed. The anterior border of the bone is relatively thick, 3 cm., and is somewhat bevelled, so as to look downward and forward. On the upper surface, near the anterior border on each side, is a broad shallow groove. The process which is seen to extend backward from the body of the nuchal probably reached the first neural. It must then have had a length of about 28 cm. the last cervical vertebra. As regards the presence of a dermal carapace of mosaic-like plates, such -as is found in Dermochelys, the remains here described afford no light. No evidence of its presence has been furnished by any of the specimens of Protostega so far produced. It is nevertheless too early to assure ourselve that there was no such a structure, considering how easily it could become detached from a carcass which was being tumbled about by the waves and dragged by carnivorous lizards. Professor Cope has described some of the vertebrae and ribs of Protostega. The vertebras, like the remainder of the skeleton, had been greatly flattened by pressure, and probably to this circumstance is to be attributed their relatively great width. The true relationships to the vertebral axis were thus rendered obscure. Notwithstanding the possession of ball and socket articulatory surfaces, it was thought that some of these vertebras belonged to the dorsal region. Others were regarded as appertaining to the neck. The length of the shortest cervical vertebra, the first behind the axis, in a specimen of Chelonia with carapace 790 mm. long is 35 mm. Professor Cope's specimen of Protostega had apparently close to three times this length, and we might therefore infer that the shortest cervical would have a length of about no mm. The longest vertebra in his possession was only 60 mm. long and had at least one plane surface. It is quite improbable therefore that it belonged to the animal's neck. The longest neck vertebra, the last but one, of a specimen as large as the one described by Professor Cope should have a length of about 142 mm., and the longest dorsal vertebra, the third, should have a length of near 270 mm. Professor Cope's account of the longest vertebra in his possesion makes it not improbable that it was the first sacral. The other vertebrae almost certainly belonged to the tail. Their size and the form of their articular surfaces both support this interpretation. Ten ribs were in Professor Cope's hands. Each had a proximal expansion, and it was evident that these ribs did not unite suturally so as to form a carapace. But since the dorsal vertebras were regarded as being so small, the conclusion was reached that either the expanded proximal ends interfered with each other in the middle line or the ribs must have been articulated to diapophyses. Since, however, the dorsal vertebrae would have varied in length from 1 08 to 275 mm., and would have been proportionally wide, while the widest rib described is 140 mm. at the proximal end, there is no necessity for believing that any rib touched either its fellow or its neighbors. The second, third, fourth, and fifth vertebras probably ranged from 250 to 275 mm., and the next two or three were not much shorter. In Dermochelys and Protosphargis the ribs in front of the fifth from the last are little, if any, broader than this fifth. Hence we may safely conclude that there were wide spaces between the ribs even near the vertebral column. The ribs certainly lacked little of having reached as advanced a stage of reduction as they have in Dermoehelys. Their condition was probably much like that seen in Capellini's restoration of Protosphargis. Professor Cope estimated that the head of the individual which he described had a length of 24^6 inches. However, basing my estimate on the length of the maxillary bone as figured on plate X of "Cretaceous Vertebrata," and making the ratio of this maxillary to the length of the skull the same as that found in Thalassochelys, I can make the whole length of the skull, including the supraoccipital spine, only about 1 8 inches, or 45 cm. The distance from the snout to the condyle would be close to 13 inches, or 32 cm. Professor Cope's specimen, judging from the size of the plastral bones in his possession, was not much smaller than my own. Hence if we estimate at 32 cm the head, measured to the condyle, we shall probably not make it too great. On the other hand, a study of the figures of the parts of the skull on plates X and XI of the work cited renders it highly probable that the bone figured on plate X as the maxillary is not such, but the postfrontal; while the figure on plate XI, said to represent the postfrontal, really portrays the maxillary, prefrontal, vomer, and palatine. In such case, the length of the skull would be about a fourth greater, or 40 cm. The length of the carapace of Chelonia has a ratio to the plastron of about 31 to 24. Hence the length of the carapace of my specimen must have been close to 3. i metres. The neck of our living marine turtles projects beyond the front of the carapace a distance equal to at least one-sixth of the length of the carapace. Hence, we are safe in allowing 50 cm. for the neck outside of the shell. We have therefore for the length of this turtle the following figures : ;.s beyond the front of the carapace a distance equal to At least on«?-&uth of the length of the carapace. Hence, we are safe in allowing 50 cm. for the neck oui he shell. We have there-	3,077	common-pile/pre_1929_books_filtered	oncertainportion12hayo	public_library	public_library_1929_dolma-0016.json.gz:3102	https://archive.org/download/oncertainportion12hayo/oncertainportion12hayo_djvu.txt
sIdmBCdEQ-1mEH1J	The Cherokees in pre-Columbian times / by Cyrus Thomas.	The present little work, which is based chiefly upon data obtained while in charge of the mound explorations carried on by the United States Bureau of Ethnology, is presented to the public as indicative of the direction in which the more recent investigations in this line appear to lead. I am under obligations to Major J. W. Powell for his kind permission to refer to the data obtained by the Bureau, bearing upon the questions discussed ; but I must be held alone responsible for the views presented. The speculative theories advanced are, of course, but tentative, yet are believed by the author to accord more nearly with the facts ascertained than any suggestion, relating to the subject, CHAPTER I. The present paper is an attempt by the writer to trace back the history of a single Indian tribe into the prehistoric or mound-building age. For this purpose the Cherokees have been selected, partly because of their isolated position geographically and linguistically, and partly because the data bearing upon the questions that arise in such an investigation are probably more complete than those relating to any other tribe of the mound section. Although the scope is thus limited, there are certain facts relating to the mound region and the aboriginal inhabitants thereof, considered generally, which must be taken into account in studying the history of any tribe of this region. The history of the Western Continent is supposed to begin with the discovery by Columbus, all that antedates that event being considered archseologic or prehistoric. While this is correct in the general sense in which it is used, yet the history of the different sections and different tribes begins with the first knowledge of them obtained by Europeans. The border-line, therefore, between the historic and prehistoric eras, varies in date when referred to the different sections and peoples. For example: history tells us nothing of what was transpiring in the area now called Ohio for a hundred hears after Cortez landed in Mexico. If it be possible to ascertain this, it must be sought in the traditions of the aborigines, the ancient monuments, and other prehistoric data of that area. It is well known that when the various sections of this country were first visited by Europeans, they were found occupied by Indian tribes ; while, on the other hand, there is no historical or other evidence, unless it be found in the monuments, that any other race or people than the Indians ever occupied this region. (The possibility of an Irish, Welsh, or Northmen pre-Columbian settlement is not at the present time taken into consideration, as it has no bearing on the subject now under discussion.) These tribes all belonged relatively to the same state of culture, which was of a grade inferior to that of the more advanced nations of Mexico and Central America. Though not recorded in written or printed tomes, these aboriginal tribes must have had a history which still lived to some extent in their traditions, languages, customs, arts, beliefs, and relics, when the whites first became acquainted with them. These languages, customs, etc., though belonging to a plane much lower than that which ethnologists will allow us to call civilized, were not the growth of a season or a lifetime, but of centuries. If they exhibit tribal or ethnic peculiarities, it may be taken for granted that these peculiarities attained their growth subsequent to the separation of the stock into the tribes among which they are found. If they are local or confined to certain geographical areas, it is reasonable to assume that they were adopted by the tribes after reaching these localities. For example: the peculiarities of the civilization of Mexico and Central America, as seen at the time of the discovery of these countries, must be considered indigenous, so long as we are unable to trace them to other sections or other peoples, — a conclusion adopted by leading historians and antiquarians. The same thing" is true to a more limited extent in regard to the subdivisions of these comprehensive groups, and affords some basis for estimating the period of occupation. Those habits, customs, or arts common among savage peoples, of course teach nothing in regard to the occupants of any special locality, except to indicate their culture status. It is therefore to those which are local or ethnic that we must looii for guidance in our search. A second fact relating to the mound region generally is, that the ancient remains found in it, though presenting various types and numerous important differences, probably the result of different local or tribal customs, are evidently the work of peoples in about the same stage of culture. But to this and other general lessons taught by the monuments there will be occasion to call attention further on. In order to clearly understand the position of the Cherokees relative to the other tribes in the mound area, we refer briefly to the linguistic distribution of these tribes when they first became known to the whites. Stretching along the Atlantic coast from the mouth of the St. Lawrence to Pamlico Sound, and extending westward to the Mississippi, was the great Algonkin family, with its numerous divisions and branches. In the midst of this great linguistic sea, occupying most of what is now New York, and extending westward on both sides of the Lakes to Michigan (with a closely allied and also a distant offshoot — the latter the Cherokees — in the region of Carolina), was the Huron-Iroquois family, with its various branches. About the head waters of the Mississippi, and reaching westward far out upon the plains and southward to the Arkansas River, was the Dakotan family. Spread over the Gulf States was the Muskokee group. Add to these the vestiges of other stocks found driven, so to speak, into the corners here and there, and we have a condition that could not have been of mushroom growth, but the outcome of centuries. It is quite probable that the family stems migrated from other sections ; but the splitting into branches and dialects took place, in part at least, after reaching the area in which these stocks were found. One proof of this is seen in the grouping and geographical distribution of the comprehensive families over the continent. Judging by the growth of languages in Europe, although the cases are not exactly parallel, centuries must be allowed for this local development. It is said by those best qualified to judge, that the shifting, changing, and tribal development known to have taken place among the Dakotas of the North-west alone, must have required three or four centuries in advance of the Columbian discovery. The necessary inference to be drawn from this is, that the tribes, or rather families of tribes, found inhabiting this " mound region " by the first European explorers, had occupied substantially the same area for hundreds of years previous thereto. Not that there was no shifting or changing of positions by tribes, for there can be no doubt that this occurred to a greater or less extent, but that the families or stocks mentioned, or most of them, were in the area included in the eastern half of the United States and Canada (which we designate in a broad sense the " mound region") for centuries preceding the advent of the white man. The same method of reasoning will apply, to some extent, to the growth of customs, as this must also have required time. The result of this course of reasoning, which seems to be justified by the facts, is to force us to one of the following conclusions: 1st, That the mound-builders, if a difPerent race or people from the Indians, disappeared from the mound area before the coming of the latter, and many centuries before the advent of the whites; or, 2d, That there was an overlapping of the two races, that is to say, they occupied the area jointly for some centuries; or, 3d, That the Indians were the authors of the ancient monuments. As it will be necessary in the course of this investigation to discuss the question of the authorship of some of these antiquities, the decision reached on this subject is important in this connection. special object of this paper. It is conceded that there is no hope of reconstructing a systematic pre-Columbian history of any one of the tribes or peoples of the area under consideration. The utmost that can be expected is, by a careful and thorough correlation of the data, to throw some light into that past which has so long been considered as wrapped in impenetrable mystery. It is by no means probable that as much will be accomplished in regard to the past of the people of this region, as has been done for Mexico and Central America, yet it is the belief of the writer that much more is possible in this direction than has generally been supposed. This tribe was for a long time a puzzling factor to students of ethnology, as they were in doubt whether to consider it an abnormal offshoot from one of the well-known Indian stocks or the remnant of some undetermined or otherwise extinct family. It now appears, however, to be the clearly settled opinion of linguists that the language is an offshoot of the Huron-Iroquois stock. This is an important fact in the study of the past, not only of this tribe, but also of the family with which it is connected, as it necessitates looking to the same point for the origin of both. When the people of this tribe first became known to the Europeans, they were located in the mountainous region including the south-east corner of what is now Tennessee, the south-west portion of North Carolina, the north-west part of South Carolina, and a strip along the northern border of Georgia,— a section which they continued to occupy down to a recent date, and where a remnant may still be found. The first notice of them is found in the chronicles of De Soto's expedition, which speak of them as the " Chelaques" or '' Achelaques," words which give more correctly the sound of the name they gave themselves than the modern Anglicized form "Cherokee." These early records locate them about the head waters of the Savannah River. The exact route of the Spanish expedition has not been satisfactorily determined ; nevertheless it is conceded by those best qualified to decide, that, when De Soto encountered people of this tribe, he was somewhere about the head waters of the Savannah, probably in the north-eastern part of Georgia. It was in this section, presumably in western North Carolina, that John Lederer encountered them during his visit to this part of the continent in 1669-70, for there can be no longer any reasonable doubt that he alludes to them where he speaks of the Indians of the " Apalatian Mountains." Their subsequent history is too well known to require further mention here. Their relation to the Iroquois indicates a northern rather than a southern or south-western origin. This seems to be confirmed by the few rays of light which tradition, the records, and archaeology throw upon their past history. Haywood states, in his ' ' Natural and Aboriginal History of Tennessee," that they " were firmly established on the Tennessee River or Hogohega (the Holston) before the year 1650, and had dominion over all the country on the east side of the Alleghany Mountains, which includes the head waters of the Yadkin, Catawba, Broad River, and the head waters of the Savannah," — a statement borne out by the fact that as late as 1756, when the English built Fort Dobbs on the Yadkin, not far from Salisbury, they first obtained the privilege of doing so by treaty with Atacullaculla, the Cherokee chief. The same authority states that they formerly had temporary settlements on New River (the Upper Kanawha) and on the head waters of the Holston. In De Lisle's maps, 1700 to 1712, Cherokee villages are located on the extreme head waters of the Holston and Clinch Rivers, as well as on and about the mouth of the Little Tennessee. Their traditions in regard to their migrations are somewhat confused, and, like all Indian traditions, must be taken only with careful sifting, and where strengthened by corroborative evidence or well-marked indications of being ancient. Yet there is a uniformity in some respects which, independent of other evidence, would justify the assumption that they contain a vein of truth and have some basis of fact. One of the most important of these is that mentioned by John Haywood in the work above named, in which they claim to have formerly lived in the Ohio valley, and to have constructed the Grave Creek mound and other earthworks in that section. This author's statement is as follows:— " The Cherokees had an oration in which was contained the history of their migrations, which was lengthy." This related "that they came from the upper part of the Ohio, where they erected the mounds on Grave Creek, and that they removed hither [East Tennessee] from the country where Monticello is situated." This tradition of their migrations was, it seems, preserved and handed down by their official orators, who repeated it annually in public at the national festival of the green-corn dance. Haywood adds, "It is now nearly forgotten ; " and Dr. D. G. Brinton informs us, in " The Lenape and their Legends," that he has endeavored in vain to recover some fragments of it from the present residents of the Cherokee nation. Haywood asserts, probably from original statements made to him, that " before the year 1690 the Cherokees, who were once settled upon the Appomattox River in the neighborhood of Monticello, left their former abodes, and came to the West, The Powhatans are said by their descendants to have once been a part of this nation. The probability is that a migration took place about or soon after the year 1632, when the Virginians suddenly and unexpectedly fell upon the Indians, killing all they could find, cutting up and destroying their crops, and causing great numbers to perish by famine. They came to New Eiver and made a temporary settlement, and also on the head of the Holston." It is obvious that in this passage the author has given his conclusion based on the "oration" mentioned, connecting with it the historical event of the sudden onslaught by the Virginia settlers upon the Indians, in 1632. That his deduction in this respect is erroneous if intended to apply to the whole tribe, is apparent from the following facts: first, because it is evident that a portion, at least, of the tribe was located in their historic seat, in and about East Tennessee and western North Carolina, when De Soto passed through the northern part of Georgia in 1540, as it is admitted that the " Chelaques "or " Achelaques " mentioned by the chroniclers of his expedition were Cherokees; second, because John Lederer, who visited this region in 1669-70, speaking of the Indians of the "Apalatian Mountains," — doubtless the Cherokees, as he was at that time somewhere in western North Carolina, — says, in his "Discoveries," "The Indians of these parts are none of those which the English removed from Virginia, but were driven by an enemy from the northwest and invited to fix here by an oracle, as they pretend, above four hundred years ago; " third, from what is shown by the archaeologic evidence which will be introduced further on. The language of Lederer indicates that he had heard substantially the same tradition as that of which Haywood fipeaks. An important addition, however, is the supposed date of this migration, which this author says was "above four hundred years" preceding the date at which he writes 1,1671-72), which would place it in the latter part of thethir- teenth century. The tradition as given by Haywood brings them from the valley of the Upper Ohio; that by Lederer, from the north west, — a close agreement as to the direction of their former home. It is doubtful whether any importance is to be attached to Haywood's statement, that there was formerly a settlement in the vicinity of Monticello, Va. It is possible, that, during the migration toward the south-east, a party or clan broke off from the main body of the tribe, and settled in that region, where they remained until the general attack by the whites in the early part of the seventeenth century. Mr. Royce, in his paper on the "Cherokee Nation of Indians," in the " Fifth Annual Report of the Bureau of Ethnology," gives a tradition preserved among the Mohicans (or Stockbridges) which he suggests may have some bearing on this question. It is that " many thousand moons ago, before the white men came over the great water, the Delawares dwelt along the banks of the river that bears their name. They liad enjoyed a long era of peace and prosperity, when the Cherokees, Nanticokes, and some other nation whose name had been forgotten, envying their condition, came from the south with a great army, and made war upon them. They vanquished the Delawares, and drove them to an island in the river. The latter sent for assistance to the Mohicans, who promptly came to their relief, and the invaders were in turn defeated with great slaughter, and put to flight. They sued for peace, and it was granted on condition that they should return home and never again make war on the Delawares or their allies. These terms were agreed to, and the Cherokees and Nanticokes ever remained faithful to the conditions of the treaty." Passing over the improbability that a marauding party forced to fly would stop and sue for peace, the tradition may, after all, have some basis of fact, as there is nothing improbable in the supposition that a band of Cherokees went the Delaware on a war expedition. What is supposed to be the earliest notice of this tribe through the settlers of Virginia is that given by the historian Burke. According to this author, Sir William Berkely, governor of that State, sent out, in 1667, an expedition consisting of fourteen whites and an equal number of friendly Indians, under command of Capt. Henry Blatt, to explore the mountainous region to the west. After seven days' travel from their point of departure at Appomattox, they reached the foot of the mountains. The first ridge they crossed is described as being neither very high nor steep; but the succeeding ones, according to their statement, " seemed to touch the clouds," and were so steep that an average day's march while passing over them did not exceed three miles. After passing beyond the mountains they came into a level region, through which a stream flowed in a westward course. Following this for a few days, they reached some old fields and recently deserted Indian cabins. Beyond this point their Indian guides refused to proceed, alleging that not far away dwelt a powerful tribe that never suffered strangers who discovered their towns to return alive: consequently the party was forced to return. It is believed by some authorities that the powerful nation alluded to in the narrative of this expedition was the Cherokees. It is probable that the point reached was what is now Floyd OP Montgomery County, and that the Indians so much dreaded were located on New River or the extreme head waters of the Holston. Another tradition related by Haywood is that one party or band of the tribo came to their mountain home from the neighborhood of Charleston, S.C., and settled south of the Little Tennessee, near what is now the Georgia line. The people of this branch called themselves "Ketawanga," and came last into the country Another tradition is, that when they first came into this region they found it uninhabited with the exception of a Creek settlement on the Hiawassee River. Ramsey, upon what authority is not known, says this was a Uchee settlement. It is apparent that all these traditions, except that relating to a clan from the neighborhood of Charleston, point to some northern locality as the former home of the tribe, and that in this respect they correspond with the linguistic indications. But these do not exhaust the evidence bearing on this question, as there is a tradition of another nation, and in this case one of the best known and most reliable of all Indian traditions, which agrees with the others in this respect. This is the Delaware legend regarding their ancestral home and migrations. The earliest writer who gives a detailed statement of it is the Rev. Charles Beatty, who visited the Delaware settlements in Ohio in 1767. According to this authority, "of old time their people were divided by a river, nine parts of ten passing over the river and one part remaining behind ; that they knew not, for certainty, how they came to this continent; but account thus for their first coming into these parts where they are now settled; that a king of their nation, wiiere they formerly lived, far to the west, left his kingdom to his two sons; that the one son making war upon the other, the latter thereupon determined to depart and seek some new habitation ; that accordingly he sat out accompanied by a number of his people and that, after wandering to and fro for the space of forty years, they at length came to Delaware River where they settled three hundred and seventy years ago. The way they keep an account of this is by putting a black bead of wampum every year on a belt they keep for that purpose.'' The reason for mentioning this brief notice of the tradition, rather than relying entirely on the fuller account given below, is that it mentions a date purporting to be derived from the Indians. The tradition as given by Hecke welder, who heard it from the Delawares themselves, and had the advantage of their interpretation and comments, is as follows : — '^The Lenni Lenape (according to the tradition handed down to them by their ancestors) resided many hundred years ago in a very distant country in the western part of the American continent. For some reason which I do not find accounted for, they determined on migrating to the eastward, and accordingly set out together in a body. After a very long journey and many nights' encampment by the way, they at length arrived on the Namaesi-Sipu, where they fell in with the Mengwe, who had likewise emigrated from a distant country and had struck upon this river somewhat higher up. Their object was the same with that of the Delawares: they were proceeding on to the eastward until they should find a country that pleased them. The spies which the Lenape had sent forward for the purpose of reconnoitring, had, long before their arrival, discovered that the country east of the Mississippi was inhabited by a very powerful nation, who had many large towns built on the great rivers flowing through their land. Those people (as I was told) called themselves Talligeu or Tallegewi. . . . Many wonderful things are told of this famous people. They are said to have been remarkably tall and stout; and there is a tradition that there were giants among them, people of a much larger size than the tallest of the Lenape. It is related that they had built to themselves regular fortifications or intrenchments, from whence they would sally out, but were generally repulsed. I have spen many of the fortifications said to have been built by them, two of which in particular were remarkable. One of them was near the mouth of the Eiver Huron, which empties itself into the Lake St. Clair on the north side of that lake, at the distance of about twenty miles north-east of Detroit. This spot of ground was, in the year 1776, owned and occupied by a Mr. Tucker. The other works, properly intrenchments, being walls or banks of earth regularly thrown up, with a deep ditch on the outside, were on the Huron River, east of the Sandusky, about six or eight miles from Lake Erie. Outside of the gateway of each of these two intrenchments, which lay within a mile of each other, were a number of large flat mounds, in which, the Indian pilot said, were buried hundreds of the slain Tallegwi whom I shall hereafter, with Col. Gibson, call Alligewi. Of these intrenchments, Mr. Abraham Steiner, who was with me at the time when I saw them, gave a very accurate description, which was published at Philadelphia in 1789 or 1790, in some periodical work the name of which I cannot at present remember. " When the Lenape arrived on the banks of the Mississippi, they sent a message to the Alligewi to request permission to settle themselves in their neighborhood. This was refused them, but they obtained leave to pass through the country and seek a settlement farther to the eastward. They accordingly began to cross the Namaesi-Sipu, when the Alligewi, seeing that their numbers were so very great, and in fact they consisted of many thousands, made a furious attack upon those who had crossed, threatening them all with destruction if they dared to persist in coming over to their side of the river. Fired at the treachery of these people and the great loss of men they had sustained, and, besides, not being prepared for a conflict, the Lenape consulted on what was to be done, — whether to retreat in the best manner they could, or to try their strength and let the enemy see that they were not cowards, but men, and too highminded to suffer themselves to be driven off before they had made a trial of their strength and were convinced that the enemy was too powerful for them. The Mengwe, who had hitherto been satisfied with being spectators from a distance, offered to join them on condition that after conquering the country they should be entitled to share it with them. by the two nations to conquer or die. " Having thus united their forces, the Lenape and Mengwe declared war against the Alligewi, and great battles were fought, in which many warriors fell on both sides. The enemy fortified their large towns and erected fortifications, especially on large rivers or near lakes, where they were successfully attacked and sometimes stormed by the allies. An engagement took place in which hundreds fell, who were afterwards buried in holes, or laid together in heaps and covered over with earth. No quarter was given, so that the Alligewi at last, finding that their destruction was inevitable if they persisted in their obstinacy, abandoned the country to the conquerors, and fled down the Mississippi River, from whence they never returned. * ' The war which was carried on with this nation lasted many years, during which the Lenape lost a great number of their warriors, while the Mengwe would always hang back in the rear, leaving them to face the enemy. In the end the conquerors divided the country between themselves. The Mengwe made choice of the lauds in the vicinity of the Great Lakes and on their tributary streams, and the Lenape took possession of the country to the south. For a long period of time, some say many hundred years, the two nations resided peacefully in this country, and increased very fast. Some of their most enterprising huntsmen and warriors crossed the great swamps, and, falling on streams running to the eastward, followed them down to the great bay river (meaning the Susquehanna, which they call the great bay river from where the west branch falls into the main stream), thence into the bay itself, which we call Chesapeake. As they pursued their travels partly by land and partly by water, sometimes near and at other times on the great salt-water lake, as they call the sea, they discovered the great river which we call the Delaware." If this tradition has any foundation in fact (and it certainly seems to have), there must have been a people to whom the name ' Tallegvvi " was applied, for on this a large portion of it hangs. Who were they ? Is it possible to trace them to any tribe of modern times ? The supposition of Col. Gibson mentioned by Hecke welder, that the name survives in "Alleghany," applied to the chief river and mountains of western Pennsylvania, is not generally accepted by linguists of the present day. Hecke welder was of opinion that " Talligewi" was a word foreign to the Algonkin, which was simply adopted by the Dela wares. Dr. Brinton says, "It is not necessarily connected with Alleghany, which may be pure Algonquin. He (Heckewelder) says, 'Those people called themselves Talligeu or Talligewi.' The accent as he gives it, 'Talligewi,' shows that the word is Tallike, with the substantive verb termination, so that Talligewi means ' He is a Tallike ' or ' It is of (belongs to) the Tallike '" (" The Lenape and their Legends," p. 320). Heckewelder's account, no doubt colored to some extent by his own interpretation, varies slightly from the tradition as given in the " Walam Olum." He interprets Namaesi Sipu by "Mississippi" because of his opinion that the migration was from the west. It is more probable that Mr. Hale is correct in assuming that it was some portion of the great river of the north (the St. Lawrence) which connects together and forms the outlet for the Great Lakes, possibly that portion which connects Lake Huron with Lake Erie. If this supposition be accepted, it would lead to the inference that the Talamatan — the people who joined the Delawares in their war with the Tallegwi — were Hurons or HuronIroquois previous to separation. Mr. Hale's views on this question are expressed in the American Antiquarian, April, 1883, as follows: — far north, — evidently the woody region north of Lake Superior. The people who joined them in the war against the Allighewi (or Tallegwi, as they are called in this record) were the Talaraatan, a name meaning ' not of themselves,' whom Mr. Squier identifies with the Hurons, and no doubt correctly, if we understand by this name the HuronIroquois people as they existed before their separation. The river which they crossed was the Messeesipe, the ' Great River ' beyond which the Tallegwi were found ' possessing the east.' That this river is not the Mississippi is evident from the fact that the works of the mound-builders extended far to the westward of the latter river, and would have been encountered by the invading nations if they had approached it from the west long before they had arrived at its banks. " The great river was apparently the Upper St. Lawrence, and most probably that portion of it which flows from Lake Huron to Lake Erie, and which is commonly known as the Detroit River. Near this river — according to Heckewelder, at a point west of Lake St. Clair, and also at another place just south of Lake Erie — some desperate conflicts took place. Hundreds of slain Tallegwi, as he was told, were buried under mounds in that vicinity. This precisely accords with Cusick's statement that ' the x^eople of the great Southern Empire had already penetrated to Lake Erie ' at the time the war began. Of course, in coming to the Detroit River from the region north of Lake Superior, the Algonquins would be advancing from the west to the east. . . . The passage already quoted from Cusick's narrative informs us that the contest lasted perhaps one hundred years. In close agree ment with this statement, the Delaware record makes it endure during the term of four head chiefs, who in succession presided in the Lenape councils." The reasons for identifying the Tallegwi or Talega of this tradition with the Cherokees, which will be more fully referred to hereafter, are briefly as follows: 1st, The veryclose agreement in sound between Tsalake, the name the Cherokees gave themselves, and Tallegivi or Talega as given in the tradition; 2d, The fact that the traditions of the Cherokees refer to the region of the Upper Ohio as their former home; 3d, The statement of Bishop Ettwein that the last of the Cherokees were driven from the Upper Ohio about the year 1700 (see Brinton's " Lenape and their Legends," p. 18); 4th, The testimony of the mounds; and, 5th, The apparent identification of the two peoples in the " Walam Olum" itself in verses 42 and 43, Part V., where it states that As this part of the record refers to a much later period than that heretofore quoted, a date subsequent to the appearance of the whites on the continent (verse 40, Part V.), there can be no doubt that it alludes to the Tallegwi in their southern home, to which, as stated in verse 59, Part IV.. they had been driven. This supposition is apparently confirmed by the fact that it connects with them the Koweta, or Creeks. This, together with the statement that the fighting was at the south, would seem to imply they were then in their mountain home or historic seat. It is probable, as will be shown hereafter, that where it is stated, in verses 19 and 20, the mounds. Although it cannot be stated positively that no tribe except the Cherokees occupied this Appalachian region between 1540 and 1690, still the evidence and indicationr. leading to that conclusion are so strong as to justify us in assuming it to be correct. It is possible that clans or small parties from other tribes may have taken up their abode temporarily with these mountain Indians; but, so far as history informs us and the remains indicate, a single instance of the kind only is known. It is therefore a fair presumption that such mounds or other works of this area, not constructed by the whites, which indicate contact with European civilization, if there be any, are to be attributed to the Cherokees. One of the ancient burial-places in Caldwell County, N.C., explored by the agents of the United States Bureau of Ethnology, is described as being a burial-pit in the form of a triangle, the two long sides 48 feet each, and the southern base 32 feet, in which the bodies and accompanying articles were deposited and then covered over, but not so as to raise any distinct mound above the natural surface of the ground, or, if so, it had settled to the level of the latter. The depth of the original excavation, the sides of which could be dis tinctly traced, varied from two and a half to three feet. In this pit were twenty-seven skeletons arranged as follows: nine lying horizontally on their backs on the bottom of the pit, with nothing over them except the dirt (these were buried separately); four were in a sitting posture, and over each a small beehive-shaped vault of cobblestones; four buried two and two in vaults, but lying horizontally at full FIG. 1. length; and ten or more iu one group, which, from their arrangement in regard to each oti:ier, the explorers believed must have been interred at one time, the skeleton of the principal personage of the group resting horizontally on his face on the bottom of the pit. Under the head of this skeleton was a larg^engrav^ed shell gorget shown in the figure (Fig. 1). Around the neck were a number of large-sized shell beads, probably the remains of a necklace; at the sides of the head, near the ears, five elongate copper beads, or rather small cylinders, varying in length from one and a half to four inches, part of the leather thong on which the smaller ones were strung yet remaining in them. These beads were made of thin copper cut into strips, and then rolled up so as to bring the edges together on one side in a straight line. The plate out of which they were made was as smooth and even as though it had been rolled. Under the breast of the same skeleton was also a piece of copper. The arms were partially extended, the hands resting about a foot from the head. About each wrist were the remains of a bracelet composed of alternate beads of copper and shell. At his right hand were four iron specimens much corroded, but sutficiently distinct to indicate their form and use. One of these was in the form of a thin celt; another, about five inches long, is apparently part of the blade of a long slender cutting or thrusting implement of some kind, as a sword, dagger, or knife (shown in Fig. 2) ; another is part of a round awl-shaped implement, a small part of the bone handle in which it was fixed yet remaining attached to it. A careful analysis of the iron of these implements has been made by Professor Clark of the United States Geological Survey, who decides that it is not meteoric. Under the left hand of the same skeleton was another eograved shell, the concave side upward, and filled with shell beads of various sizes. Around and over the skeleton of this chief personage, with their heads near his, were nine other skeletons. Under the heads of two of these were two engraved shells. Scattered over and between the skeletons of this group were numerous polished celts, discoidal stones, copper arrow-points, plates of mica, lumps of paint, etc. That these iron articles cannot be attributed to an intrusive burial is evident from the preceding description. They were found at the bottom of the pit, which had been dug before depositing the bodies. With them were engraved shells, polished celts, and other relics of this character, and all were deposited with the principal personage who had been buried in the mound. There were, in fact, no indications whatever of intrusive burials here. As it is conceded that neither the Indians nor the more civilized tribes of Mexico and Central America were acquainted with the art of manufacturing iron, the presence of these iron articles in the mound indicates contact with the civilization of the Old World. Moreover, a careful examination of the copper cylinders will probably satisfy any one that the plate of which they were made had been rolled or regularly hammered by other than stone implements, and that the strips had been cut into proper shape with some hard metallic instrument. It is reasonable, therefore, to conclude that this burial-pit was dug, and the bodies deposited, subsequent to the discovery of America by Columbus, and in all probability after the date of De Soto's expedition. As the Cherokees alone inhabited this particular section from the time of De Soto's expedition until it was settled by the whites, it is more than probable that the burials were made by them. This is an im])ortaiit step in tlio attempt to trace backward the history of tills tribe, as it is seemingly the link which crosses the border-line between the historic and prehistoric eras. It should therefore be well sustained by other data before being used as a basis for further advance; but this is not wanting. On the same farm as the preceding was another burialplace, also explored by the agents of the Bureau of Ethnology, of which an account is given in the "Fifth Annual Report." In this case we have a true mound, although of comparatively little height. This was almost a true circle in outline, thirty eight feet in diameter, but not more than a foot and a half in height above the natural surface of the ground. Thorough excavation, however, revealed the fact that the builders of the mound had first dug a circular pit of the same diameter, with perpendicular margin, to the depth of three feet, on the bottom of which they deposited their dead, some in little stone vaults and some without any stone enclosure, and covered them over with earth, raising the mound above the pit. A plan of the pit, showing the stone vaults and skeletons after the removal of the dirt, is given in Fig. 3. The beehive-shaped vaults were built of water-worn bowlders, with merely sufficient clay to hold them in place. No. 1 indicates a stone vault standing exactly in the centre of the pit. In this case a small circular hole a little over three feet in diameter, and extending down three feet below the bottom of the pit, had been dug, the body or skeleton placed perpendicularly upon its feet, and a wall built up around it, converging, after a height of four feet was reached, so as to be covered at the top by a single soapstone slab of moderate size. On the top of the head of the skeleton, and immediately under the capstone, were several plates of silver mica, which had evidently been cut with some rude implement. Although the bones were much decayed, yet they were retained in an upright position by the dirt which filled the vault, — an indication that the flesh had been removed before burial, and earth packed around the skeleton as the vault was built up. the bottom of the pit. Nos. 11, 12, and 13 are uncovered skeletons in a squatting posture. Nos. 11 and 15 are uncovered skeletons lying horizontally on the bottom of the pit. No. 16 is an unenclosed squatting skeleton of unusually large size: A, a quantity of black paint in lumps; and B, a cubical mass of water-worn bowlders built up solidly and regularly, twenty-four inches long, eighteen inches wide, and eighteen inches high, but with no bones, specimens of art, coals, ashes, or indications of fire on or about it. Many of the stones of the little vaults and the earth immediately around them, on the contrary, bore unmistakable evidences of fire; in fact, the heat in some cases had been so intense as to leave its mark on the bones of the enclosed skeletons, — another indication that the flesh had been removed before burial. stone pipe near the mouth of No. 16. The proximity of this mound to the Triangle, the occurrence of the pit, and the similarity in the modes of burial, are sufficient to justify us in attributing them to one and the same people. Two hundred yards east of the Triangle was another low mound, covering a circular pit similar to that described. In this were twenty-five skeletons and one stone heap. Some of the skeletons were in a sitting posture, covered with stone vaults, others unenclosed. Some were stretched horizontally on the bottom of the pit, unenclosed. Four of the latter were lying together, with large stones resting on their legs below the knees. In a different part of the same county, another similar circular burial-pit was explored, in which, besides the separate sitting and horizontal skeletons, there was a kind of communal grave similar to that in the Triangle. As there can be no reasonable doubt that all these are the burialplaces of one tribe, and there are no indications of intrusive burials, it is legitimate to consider them together, and to what is found in any one. Referring to the account given in the "Fifth Annual Report of the Bureau of Ethnology," it is seen that the following articles were found huried with the skeletons of the lastmentioned pit alone: one stone axe; forty-three polished celts; nine vessels of clay, including four pots and two foodcups, the handle of one representing an owl's head, and that of the other an eagle's head; thirty-two arrow-heads; twenty soapstone pipes, mostly uninjured; twelve discoidal stones; ten rubbing-stones; one broken soapstone vessel; six engraved shells, some of the designs on them like that shown in Fig. 1; four shell gorgets; one sea-shell {Busy con per versum) entire, and two or three broken ones; five very large copperheads; a lot of shell fragments, some of them en graved ; a few rude shell pins made from the columellce of sea-univalves ; shell beads and a few small copper beads. It is evident, from the mode of burial and the articles found, that these works cannot be attributed to white men of post-Columbian times. Can they be attributed to the Indians found inhabiting this region at the time of the advent of the whites? If the evidence justifies this conclusion, we may then attribute them without hesitancy to the Cherokees. Lawson, who travelled through North Carolina in 1700, states that "the Indians oftentimes make of a certain large sea-shell a sort of gorge, which they wear about their neck in a string, so it hangs on their collar, whereon is sometimes engraven a cross or some odd sort of figure which comes next in their fancy." Beverly, in his "History of Virginia," evidently alluding to the same custom, says, "Of this shell [the conch] they also make round tablets of about four inches in diameter, which they polish as smooth as the other, and sometimes they etch or grave thereon circles, stars, a halfmoon, or any other figure suitable to their fancy." Adair states, in his "History of the American Indians," that the priest wears a breastplate made of a white conch-shell, with two holes bored in the middle of it, through which he puts the ends of an otter-skin strap, and fastens a buck-horn white button to the outside of each. Here, then, is evidence of a custom among the Indians precisely similar to that which prevailed among the moundbuilders of the region to which reference has been made. Nor does the comparison stop with the general resemblance in customs; for among the shells found in the burialmounds mentioned was one with a cross engraved upon it, and on others were engraved figures that might be readily taken for stars and half-moons (Fig. 4). Moreover, while some are "engraved," others are "smooth," without any devices upon them ; and all are pierced with holes for inserting strings by which to hang them about the neck. They are That shells of this kind, bearing precisely similar engraved designs, were in use among the veritable mound-builders, is proven by the fact that they have been found in mounds of some of the most important groups of Georgia, Tennessee, and elsewhere. This fact is sufficient of itself to show that the North Carolina burial-places alluded to belong to the mound-building age. If these shell ornaments are the work of Indians, as appears from the statements of the above-named writers, they must have been used by the Cherokees, and buried with their dead. The author last above quoted says, that at the fall of the leaf the Indians gather hickory-nuts, "which they pound with a round stone, upon a stone, thick and hollowed for the purpose." Quite a number of precisely such stones as here mentioned, "thick and hollowed" at the ends, were found in the mounds of Caldwell County, N.C. All who examined them ascribed them, without hesitancy, to the use mentioned by Adair. Another fact not mentioned in the preceding description of these mounds and burial-places is, that in one, — the circular pit, — mixed with those having heads of the ordinary form, were some eight or ten skeletons with heads of elongate form, due to artificial pressure. This furnishes strong evidence that the people who buried here were Indians. It is true, it was not a custom of the Cherokees to compress the head, but it was of their neighbors and hereditary foes, the Catawbas As this is the only instance of skulls of that form being found in the mounds of this section, it is possible they were captives from that tribe; but why buried here, unless they had been adopted by the Cherokees, is a question difficult to answer. with the stem made in connection with the bowl, though some of them are without this addition, consisting only of the howl, with a hole for the insertion of a cane or wooden stem. By turning to Adair's "History of the American Indians," we find this statement: "They [the Indians] make beautiful stone pipes, and the Cherokees the best of any of the Indians, for their mountainous country contains many differ- ent sorts and colors of soils proper for such uses„ They easily form them with their tomahawks, and afterwards finish them in any desired form with their knives; the pipes used with the fire, when they become quite hard. They are often a full span long, and the bowls are about half as long again as those of our English pipes. The fore-part of each commonly runs out with a sharp peak two or three fingers broad and a quarter of an inch thick." Not only were pipes made of soapstone found with the stem carved in connection with them, as indicated in the above quotation, but two or three were obtained of precisely the form mentioned by Adair, with the fore-part running out in front of the bowl ; and others of the same form have been found in West Virginia, Ohio, and elsewhere. Some of the forms, including one from a mound in Sullivan County, East Tenn., are shown in Figs. 5 and 6. As will be seen, one of these, of which numerous examples were found, has a very modern appearance, — a form which was first adopted in England in the time of Queen Elizabeth. It may be remarked, in passing, that the mound in Sullivan County, Tenn. (shown in Fig. 37, ''Fifth Annual Eeport of the Bureau of Ethnology"), belongs to the same type as that of Caldwell County, N.C. Here, however, instead of a pit, a circular wall some three or four feet high is built on the natural surface of the ground, and the bodies or skeletons are seated in regular order on this natural surface, after charcoal and ashes have been strewn over it, and over each a little vault built. Haywood, in his "Natural and Aboriginal History of Tennessee," says, "Mr. Brown, a Scotchman, came into the Cherokee nation in the year 1761, and settled on the Hiawassee River or near it. He saw on the Hiawassee and Tennessee the remains of old forts, about which were axes, guns, hoes, and other metallic utensils. The Indians at that time told him that the French had formerly been there and built these forts." wood refers to. An overflow and a change in the channel of the river brought to light the remains of old habitations and numerous relics of the people who formerly dwelt there. Moreover, this was in the precise locality where tradition and the statement of the Cherokees located a Cherokee town. Digging was resorted to in order to complete the exposure which the water had begun. The only object in view in referring to this exploration is to note some of the articles found: ten discoidal stones precisely like those from the mounds of Caldwell County, N.C. ; nine strings of glass beads; a number of shell beads exactly like those from the mounds; a number of flint arrow-points; one soapstone pipe; some pieces of smooth sheet copper; three conical copper ear pendants precisely of the pattern of some found in one of the Carolina mounds ; three buttons of modem type ; one small brass gouge ; fragments of iron articles belonging to a bridle ; one bronze sleigh-bell ; one stone awl or drill ; fragments of a soapstone pot; one soapstone gorget; several polished stone celts similar to those found in the Carolina mounds; grooved stone axes; a piece of sheet lead. This admixture of articles of civilized and savage life confirms the statement made by Haywood, at least so far as regards the early presence of white people in this section. It follows, from what has been presented, that the Indians living here after the appearance of the whites must have been Cherokees; and the fact that the implements and ornaments of aboriginal manufacture found here are throughout precisely like those obtained from the mounds mentioned, affords a very strong proof that the latter are to be attributed to the same people. Additional and perhaps stronger evidence, if stronger be needed, that the people of this tribe were the authors of most of the ancient works in western North Carolina and East Tennessee, is to be found in certain discoveries made by the Bureau assistants in Monroe County, Tenn. A careful exploration of the valley of the Little Tennessee River from the point where it leaves the mountain to its confluence with the Holston was made, and the various mound groups located and carefully surveyed. Here, on the exact sites of the "Over-hill towns," as shown by Henry Timberlake's map of 1765, using the map of the same region by the Geological Survey as a mears of comparison, were found mound groups ; not in a general sense only, but in the order given and at the points indicated, a group for each town, and in the only habitable spots the valley, for this distance, affords. Commencing with the large island immediately below the mouth of Tellico River at the west end of Timberlake's map, we see the town of Mialoqua, partly on the island, and partly on the south bank. Referring to the Bureau map, which will appear in the general report of mound explorations, we see that the mounds are also partly on the island, and partly on the south bank. On the latter map, group No. 2 corresponds with "Toskegee" of Timberlake's map; No. 3, with "Tommotley;" No. 4, with "Toqua;" No. 5, with "Tennessee;" No. 6, with "Chote;" No. 7, with "Settacoo;" No. 8, with "Half-way Town;" No. 9, with "Chilhowey;" and No. 10, with "Tellassee." Such remarkable coincidence cannot be attributed to mere chance. There is also the additional fact that the evidences of village sites which must have been left by the Cherokee towns were found only about the groups, though careful search was made by the Bureau agents along the valley. As these mounds, when explored, yielded precisely the kind of ornaments and implements used by the Cherokees, it is reasonable to believe they built them. Ramsey also gives a map of the Cherokee towns in his "Annals of Tennessee;" but his list, although corresponding, so far as it goes, with the order given by Timberlake, evidently refers to a date corresponding with the close of their occupancy of this section. Bar tram gives a more complete list. This includes some towns on the Holston (his ''Cherokee") River and some on the Tellico Plains, the localities corresponding" with mound groups discovered hy the Bureau agents. For example: some three or four groups are in the region of the Tellico Plains, and five or six on the Little Tennessee below Fort Loudon, and on the Holston near the junction of the two. One large mound and a group were discovered on the "Big Island" mentioned by Bartram, on which he locates a town, but fails to give the name. The largest of these groups is situated on the Little Tennessee above Fort Loudon, and corresponds with the position of the ancient "Beloved town of Chota" ("Great Chote" of Bartram) as located by tradition and Timberlake's map. According to Ramsey, at the time the pioneers, following in the wake of Daniel Boone near the close of the eighteenth century, were pouring over the mountains into the valley of the Watauga, a Mrs. Bean, who was captured by the Cherokees near Watauga, was brought to their town at this place, bound, and taken to the " top of a mound " to be burned, when Nancy Ward, then exercising in the nation the functions of tlie "beloved "or " pretty woman," interfered, and pronounced her pardon. Ramsey does not give his authority for this statement, but, in all probability, obtained the information from the descendants of Mrs. Bean, who, as the writer knows, were residing in Hawkins County as late as 1850, and probably at the present time. " Nancy Ward " probably received her English name from some white family that resided for a time in that section. During the explorations of the mounds of this region by the Bureau agents, a peculiar type of clay beds was found in several of the larger tumuli. These were always saucershaped, varying in diameter from six to fifteen feet and in thickness from four to twelve inches. In nearly every instance there was a series one above another, with a layer of coals and ashes between. A series usually consisted of from three to five beds, sometimes only two. decreasing in diameter from the lowest one upwards. These apparently marked the stages of the growth of the mound, the upper one always being near the surface. The large mound on the supposed site of Chota, and possibly the one on which Mrs. Bean was about to be burned, was thoroughly explored, and found to contain a series of these clay beds, which always show the action of fire. In the centre of some of these were found the charred remains of a stake, and about them the usual layer of coals and ashes; but in this instance immediately around where the stake stood were the charred fragments of human bones. There may be no connection between this fact and Ramsey's statement, yet the coincidence is suggestive. The burials in this mound, which was a large one, some twelve feet high, were at various depths, from two and a half to nine feet, and, although the series of clay beds indicated growth, there was nothing to indicate separate and distinct periods, or to lead to the belief that any of these were intrusive. On the contrary, the evidence is pretty clear that all these burials were by one tribe or people. It is believed that no satisfactory evidence of intrusive burials has been discovered in this entire Appalachian region. By the side of nearly every skeleton in this mound were one or more articles, as shell masks, engraved shells similar to those heretofore mentioned, shell pins, shell beads, perforated shells, discoidal stones, polished celts, arrow-heads, spearheads, stone gorgets, bone implements, clay vessels, and copper hawk-bells. The last-named articles were with the skeleton of a child found at the depth of three feet and a half. They are precisely of the form of the ordinary sleighbell of the present day, but with pebbles and shell beads for rattles. with Europeans must be conceded. In another mound a little farther up the river, one of a group marking the site of one of the " Over-hill towns," were discovered two carved stone pipes of a comparatively modern Cherokee type. Duriug the fall of 1888, a farmer of East Tennessee, while examining a cave with a view of storing potatoes in it during the winter, unearthed a well-preserved human skeleton, which was wrapped in a large piece of cane matting. This, which measures about six by four feet, is quite pliant, and, with the exception of a rent in the corner, perfectly sound. It has a broad, submarginal stripe of red running around it. Enclosed with the skeleton was a piece of cloth made of flax, about fourteen by twenty inches, almost uninjured, pliant, but apparently unfinished. The stitch in which it is woven is precisely the same as that imprinted on pottery shown in Fig. 96 in Mr. Holmes's paper on "Mound Builders' Textile Fabrics" ("Third Annual Report of the Bureau of Ethnology"). Although the earth in the cave contains salts which would aid in preserving any thing buried in it, these articles cannot be assigned to any very ancient date, especially a? there were with them the remains of a dog from which the skin had not all rotted away. These were in all probability placed here by the Cherokees of modern times, and form a link between the historic and prehistoric times not easily broken. Another important find was made in this locality by one of the Bureau agents in 1889. This is a small stone on which some characters have been rudely etched, and is shown in Fig. 7, on the next page. An examination by those familiar with the subject will probably soon satisfy them that some of the characters, if not all, are letters of the Cherokee alphabet. As the presence of the stone in the mound cannot be attributed to an intrusive burial, it is evi- dent that the mound must have been built since 1820, that Mr. Guess was not the author of the Cherokee alphabet, or that the stone is a fraud. The mound in which this was found is described as follows: — " The Tipton group is situated on the north side of the Little Tennessee, about two miles from Morganton. No. 3 of this group, which stands about one hundred feet from No. 2, is of small size, measuriog twenty-eight feet in diameter and about five feet in height. Some large trees," says Mr. Emmert, the Bureau agent, " were standing on the mound, and Mr. Tipton informed me that he had cut other trees off of it forty years ago, and that it had been a cluster of trees and grape-vines as far back as the oldest settler could recollect. There was an old stump yet in the centre, the roots of which ran down in the mound almost or quite to where the skeletons were found. . . . Having worked to the bottom, I found here nine skeletons lying at full length on the natural surface, with faces up, and surrounded by darkcolored earth. No. 1 (as shown in the diagram which accompanies his report) was lying with head to the south ; while No. 2, close by the side of it, had the head to the north, and feet almost touching the head of the other. On the same level, but apart from the preceding, were seven other skeletons lying closely side by side, heads all to the north, and all in a line. No relics of any kind were found with any of the skeletons except No. 1. Immediately under the skull and jaw-bones were two copper bracelets, an engraved stone (Fig. 7), a small drilled stone, a single copper bead, a bone instrument, and some small pieces of polished wood. The earth about the skeletons was w^et, and the pieces of wood were soft and colored green by contact with the copper bracelets. These bracelets had been rolled up in something which crumbled off when they were taken out, but whether buckskin or bark I was unable to decide. The engraved stone was lying partially under the skull. I punched it with my steel prod on the rough side in probing, before I reached the skeletons." As soon as the collections made by Mr. Emmert during this exploration were received at the office in "Washington, a member of the Bureau was sent to the field where Mr. Emmert was at work, to learn the whole history of the find. This course was taken by the Bureau merely as a means of being fortified with all possible evidence as to the facts of the find being as stated. The examination by the person sent confirmed the statement by Mr. Emmert in every particular. This, therefore, necessitates one of two conclusions,— that the mound was thrown up since 1820, or that some one was at work on the Cherokee alphabet before Mr. Guess's time. But this is a question which has no bearing on the present discussion. What has been presented is probably sufficient to convince any unbiassed mind that the Cherokees were mound-builders, nevertheless tliere is other evidence of a more general character which serves to show that the builders of the East Tennessee and North Carolina mounds were contemporaneous with the authors of the works of other sections. Proof that in general the mound-builders were Indians would, as a matter of course, have a strong bearing on the case under discussion, but this would require too much space to be introduced here. The following extracts from Major J. W. Powell's article on "Prehistoric Man in America," in the Forum of January, 1890, will give what is now becoming the settled conclusion of most of the leading archaeologists of the present day: — "The research of the past ten or fifteen years has put this subject in a proper light. First, the annals of the Columbian epoch have been carefully studied, and it is found that some of the mounds have been constructed in historical time, while early explorers and settlers found many actually used by tribes of North American Indians: so we know many of them were builders of mounds. Again, hundreds and thousands of these mounds have been carefully examined, and the works of art found therein have been collected and assembled in museums. At the same time, the works of art of the Indian tribes, as they were produced before modification by European culture, have been assembled in the same museums, and the classes of collections have been carefully compared. All this has been done with the greatest painstaking, and the mound-builders' arts and the Indians' arts are found to be substantially identical. No fragment of evidence remains to support the figment of theory that there was an ancient race of mound-builders superior in culture to the North American Indians. ... It is enough to say that the mound-builders were the Indian tribes discovered by white men." Once it is admitted that the mound-builders were Indians, it requires much less proof to carry conviction that a particular tribe was accustomed to erect such structures. There are, however, two facts which seem to carry back the Cherokees to the mound-building age, even independently of this general argument. The first of these to which attention is called is that afforded by a certain class of stone graves or cists found in great numbers in some sections. These cists, usually designated "box-shaped stone graves," are formed of rough unhewn slabs or flat pieces of stone, thus : first, in a pit some two or three feet deep and of the desired dimensions, dug for the purpose, a layer is placed to form the floor; next, similar pieces are set on edge for the sides and ends, over which other slabs are laid flat, forming the covering; the whole, when finished, making a rude box-shaped coffin or sepulchre. Sometimes one or more of the six faces are wanting; occasionally the bottom consists of a layer of water-worn bowlders; sometimes the top is not a single layer, but other pieces are laid over the joints; and sometimes they are placed in the fashion of shingles. They vary from nine inches to three feet. Now, it happens that quite a number of graves of this particular type are found on the site of one of the "Over-hill towns" heretofore mentioned, and others are scattered over parts of the Cherokee district. As the location of those about the village site is such as to justify the belief that they were contemporaneous with the existence of the village, we must conclude that the authors of the graves of this type, and the Cherokees, were contemporaneous. Additional proof of this is found in the seemingly conclusive evidence, which is too lengthy to be introduced here, that the graves of this form found south of the Ohio are due to the Shawnees. The well-known fact that the Cherokees and Shawnees were long hereditary and bitter foes, almost constantly at war with each other, would seem to forbid the above supposition that a Shawnee colony was living in connection with a Cherokee village; yet the following historical items furnish a satisfactory explanation. Haywood, in his "Natural and Aboriginal History of Tennessee," gives the following statement by Gen. Eobertson: 'In 1772 the Little Corn-Planter, an intelligent Cherokee chief who was then supposed to be ninety years of age, stated, in giving a history of his own nation, that the Savannechers, which was the name universally given by the Indians to those whom the English call Shawnees, removed from Savannah Eiver, between Georgia and South Carolina, by permission of the Cherokees, to Cumberland, they having been attacked and almost ruined by a combination of several of the neighboring tribes of Indians; that many years afterwards a difference took place between the two nations, and the Cherokees, unexpectedly to the Shawnees, marched in a large body to the frontier of the latter." "History of the Indian Tribes:" "A discontented portion of the Shawnee tribe from Virginia broke off from the nation which removed to the Scioto country in Ohio about the year 1730, and formed a town known by the name of 'Lulbegrud' in what is now Clark County (Kentucky), about thirty miles east of this place (Lexington). This tribe left this country about 1750, and went to East Tennessee, to the Cherokee nation." It is very probable that the stone graves about the site of the " Over-hill town " are due to this band. The importance and bearing of this evidence in the present connection lie in the fact that numbers of graves of this type are found in mounds, some of which are of comparatively large size, and connected with works which no one hesitates to attribute to the true mound-building age. Sometimes they are arranged in these tumuli in two, three, and even four tiers. Not only are they found in mounds of considerable size, but they are also connected with one of the most noted groups in the United States; namely, the one on Col. Tumlin's place, near Carters ville, Ga., known as the "Etowah mounds," of which a full description will be found in the "Fifth Annual Report of the Bureau of Ethnology" and in Jones's "History of the Southern Indians." In the smallest of the three large mounds of this group were found stone graves precisely of the type described ; not in a situation where they could be attributed to intrusive burial, but in the bottom layer of a mound some thirteen or fourteen feet high, with an undisturbed layer, two feet thick, of hard-packed clay above them. In them were found the remarkable figured copper plates and engraved shells which are described by the writer in the "Fifth Annual Report of the Bureau of Ethnology," also in Science. In singular corroboration of the idea here advanced, the only other similar copper plates were found in a stone grave at Lebanon, Tenu. ; in a stonegrave mound at Mill Creek, southern Illinois; in a stone grave in Jackson County, 111. ; in a mound of Madison County, 111. ; and in a small mound at Peoria, 111. ; not all, of course, attributed to Shawnees, but in stone graves or mounds, thus connecting them with the mound-building age, which is the only point with which we are at present interested. Another important link in this discussion is found in the engraved shells, of which specimens were found in the mounds of North Carolina and East Tennessee attributable to the Cherokees. The following list, showing localities where and circumstances uader which specimens have been found, will suffice to show their relation to the mounds and stone graves: Lick Creek, and near Knoxville, E. Tenn., in mounds; near Nashville, Tenn., in mound, also in stone grave; Old Town, Franklin, and Sevierville, Tenn., in mounds; Bartow County, Ga., in stone grave in mound; Monroe County, E.Tenn., Lee County, Va., and Caldwell County, N.C., in mounds; near Mussel-Shoals, Ala., in cave; New Madrid. Mo., and Union County, III, in mounds; St. Clair County, 111., in stone grave. As a large number of these bear exactly the same carved designs as those found in the Cherokee mounds, the evidence seems conclusive that we must assign them to the same age. This, of course, connects the Cherokees with the moundbuilders' era, and furnishes a justifiable basis for another backward step. But before attempting to take this, I add some information on the point now under discussion, gathered by Mr. James Mooney during his ethnological investigations among the Cherokees in behalf of the Bureau of Ethnology. This is given in a paper read before the Anthropological Society of Washington City. "In connection with my work, at the instance of the Bureau of Ethnology, in the summer of 1887, I visited the East Cherokee reservation in western North Carolina. Being delayed over night at a small town called Webster, about twenty miles from the reservation, an opportunity was afforded to make the acquaintance of Capt. J, W. Terrell, the postmaster, an intelligent American, who in his younger days had been a trader among the Cherokees, and who has some knowledge of the language. In the course of our conversation he stated that about thirty years ago he had been told by an old Indian named Tsiskwaya that the Cherokees had built the mounds in their country, and that on the occasion of the annual green-corn dance it was the custom in ancient times for each household to procure fresh fire from a new fire kindled in the town-house. I afterward found that this Tsiskwaya had been regarded as an authority on such matters. "Subsequently, in investigating the ceremonies of the green-corn dance, this statement was confirmed by another old man, who volunteered the additional information that it was customary to begin a mound on the occasion of this dance, when representatives of the seven gentes brought baskets filled with earth, which was placed in a common pile with appropriate ceremonies, and afterward added to by the labors of the common people. This man is somewhat unreliable, and his testimony would have little weight by itself, but it is of value in so far as it is borne out by the statements of others. It is proper to state, however, that he was one of the masters of ceremonies at the green-corn dance of 1887, so that he may reasonably be supposed to know something on that subject. Of curious interest in this connection is the fact that Miss Alice C. Fletcher witnessed a similar ceremonial mound-building at one of the secret rites of the Winnebagoes. "But the most detailed statement as to the mounds was obtained afterward from Ayunini ('Swimmer'), who, although not an old man, is one of the most prominent Cherokee shamans and a general conservator of Indian knowledge, being probably better acquainted with the myths, traditions, and ceremonial formulas than any other man-of the tribe. For some time he refused to talk, but this difficulty was finally overcome by appealing to his professional pride; and his stock of Indian lore proved so extensive, that I brought him to the house, and kept him with me most, of the time. This aroused the jealousy of rivals, who took occasion to circulate damaging reports as to his lionesty; but in ever}^ instance I found his statements borne out by other testimony or by general analogy. Making due allowance for the mythologic features, which rather serve to establish its traditional character, his account is probably as full and accurate as could be expected at this late day, and briefly is as follows: — " ' The practice of building mounds originated with the Anintsi, and was kept up by the Ani-Kituhwagi. They were built as sites for town-houses (see Bartram's account of Cowe mound and town-house) ; and some were low, w^hile others were as high as small trees. In building the mound, a fire was first kindled on the level surface. Around the fire M as placed a circle of stones, outside of which were deposited the bodies of seven prominent men, one from each gens, these bodies being exhumed for the purpose from previous interments.' "Swimmer said that his statement was obtained from a man who died in 1865, aged about seventy. Some time later, while talking with an intelligent woman in regard to local points of interest, she mentioned the large mound near Franklin, in Macon County, and remarked, 'There's fire at the bottom of that mound.' "Without giving her any idea of what Swimmer had said, I inquired of her how the fire got there, when she told substantially the same story as she had obtained it from an old woman now dead. She was of the opinion that this fire existed only in the larger mounds; but I found on investigation that the belief was general that the fires still existed, and occasionally sent up columns of smoke above the tops of the mounds." migration. If their former home was in the region of the Upper Ohio, and they stopped for a while on New River and the head waters of the Holston, their line of retreat was in all likelihood up the valley of the Great Kanawha. This supposition agrees also with the fact that no traces of them are found in the ancient works of Kentucky or middle Tennessee. In truth, the works along the Ohio River from Portsmouth (except those at this point) to Cincinnati, and throughout northern Kentucky, are different from the typi- cal works of Ohio, and most of thetn of a type found in no other district. On the other hand, it happens, precisely in accordance with the theory advanced, that we find in the Kanawha valley, near the city of Charleston, a very extensive group of ancient works, stretching along the banks of the stream for more than two miles, consisting of quite large as well as small mounds, circular and rectangular enclosures, etc. A careful survey of this group has been made, and a number of the tumuli, including the larger ones, explored by the representatives of the Bureau of Ethnology. The result of these explorations has been to bring to light some very important data bearing upon the present question. In fact, the discoveries made here seem to furnish the connecting link between some of the works of Ohio and those of East Tennessee and North Carolina ascribed to the Cherokees. Subsequent to the preparation of the paper on the "BurialMounds of the Northern Section," published in the "Fifth Annual Report of the Bureau of Ethnology," further explorations and a careful resurvey of the group near Charleston were made. In order to show the bearing of the data obtained on the questions involved in this discussion, it is necessary to give somewhat detailed descriptions of some of the mounds explored. Mound 15 of this group (for convenience the numbers in the original sketch are used) was sixty-five feet in diameter and five in height, though a considerable portion had been ploughed ofip in cultivating the soil. In the top was a basin-shaped fire-bed somewhat oval in outline, being about seven feet long and four feet wide. This was composed of a mixture of clay and ashes burned to a brick red on the upper side; but the under side had a black, greasy appearance. Below this was a similar bed, on and about which were numerous small fragments of bones, but too much animal. These basin-shaped beds remind us of those of similar form found in the mounds of East Tennessee, and present one indication of relationship between the mound-builders of the two sections. Mound No. 18, about the same size as the preceding, contained a similar series of basin-shaped fire-beds, lying one below the other in the central portion. Below them, near the bottom of the mound, was a considerable bed of charcoal and ashes; and immediately under this, on the original surface of the ground, the fragments of a skeleton, with which were a number of broken arrow and spear heads. Mound No. 1 of the group is of large size, measuring five hundred and twenty feet in circumference and thirty-three in height. This was explored by sinking a shaft twelve feet square to the bottom. At the depth of from three to four feet, in a bed of mixed clay and ashes, were three skeletons lying extended on their backs, doubtless intrusive burials. From this point downwards for twenty feet, nearly all of the material in the shaft consisted of the same mixed substances, so hard as to require the constant use of the pick. At the depth of twenty-four feet there was a sudden change to a much softer and darker-colored earth, in which were the casts and decayed fragments of poles and logs from six to twelve inches in diameter. These, together with fragments of bark, ashes, and animal bones which had been split lengthwise, continued through a layer of about six feet. At the depth of thirty-one feet a human skeleton was discovered lying prostrate, head north, the skull crushed but partly preserved by contact with a sheet of copper (only fragments of which remained) that probably once formed part of a head-dress of some kind. By enlarging and curbing, the shaft was extended to a diameter of sixteen feet. It was then found that a layer of elm-bark had been carefully spread, with the inner side up, upon the smoothed and wellpacked surface of the ground. This had been covered with a layer a few inches thick of fine white ashes. On this the body was laid, and covered with similar bark. Ten other skeletons, all buried in the same manner, were found at this point, arranged, five on each side, in a semicircle around the central one just mentioned, with feet turned toward it. With each skeleton on the east side of the centre was a fine, apparently unused lance-head ; and by the side of the northern one of these five, a fish-dart, three arrow-points, and some decayed mussel-shells. Nothing was found with the other five. With the central one, in addition to what has been mentioned, were six shell beads and a large lance-head. But what interests us more at present is the fact that near the head of the latter was a conical vault of very hard clay, about four feet high and five feet in diameter. This was partially filled with rotten bark, human bones, and dark, decomposed matter. Immediately under this, but covered with clay, were two circular holes about sixteen inches in diameter, and four feet deep. A similar pair of holes was found at the head of each of the ten surrounding skeletons, ranging in depth from two to three feet, and in diameter from eight to twelve inches. The little beehive vault, resembling so exactly in form and size those of North Carolina, although built of clay, is another indication cf relationship between the mound-builders of the two sections. On the other hand, the burial between the layers of bark is precisely what is often found to be the case in the Ohio mounds, as appears from the following statements by Messrs. Squier and Davis in ' 'Ancient Monuments:" "The course of preparation for the burial seemed to have been as follows: the surface of the ground was first carefully levelled, and packed over an area perhaps ten or fifteen feet square. This area was then covered with sheets of bark, on which, in the centre, the body of the dead was deposited, with a few articles of stone at its side, and a few small ornaments near the head. It was then covered over with another layer of bark, and the mound heaped above." probably been wrapped in bark. That there was a wooden structure of some kind covering" the area occupied by the skeletons is more than probable, as thus only can we account for the timbers. The holes mentioned may indicate the position of a former structure, but this had been removed before the burials took place. It would seem that most, if not all, of the burials took place at one time, and after the flesh had been removed. Mound 21, known locally as the "Great Smith Mound," is the largest of the group, being a regular cone, thirty-five feet high, and one hundred and seventy-five feet in diameter at the base. This was explored by sinking a shaft to the bottom twelve feet in diameter. It is a double mound, or mound of two stages. The first building carried it to the height of twenty feet: after a considerable time had elapsed, another stage of work carried it to its present height. Near the top were some skeletons, probably intrusive burials. At the depth of twelve feet the explorers began to find the fragments and casts of logs, the first being that of a black-walnut log, which must have been ner.rly twelve inches in diameter and several feet in length. Further excavation made it apparent that these timbers were the remains of a wooden vault about thirteen feet long and twelve feet wide. From all the indications, — the casts of the posts and logs, the bark and clay lining, the fallen timbers, the bark of the roof, etc., — it was inferred that the vault was constructed as follows: after the mound, which was at this time twenty feet high, had been standing for an indefinite length of time, a square pit, twelve by thirteen feet, was dug m the top to the depth of six feet; posts were then placed along the sides and ends, the former reaching only to the surface, but the central ones at the ends rising four feet higher; on the latter was placed the ridge-pole (the walnut log first encountered) ; the sides were plastered with a mixture of clay and ashes, and possibly lined with bark; the roof, which had fallen in, was made of poles, and covered with bark; over all was heaped the superincumbent mound fifteen feet in height. In this vault were five skeletons, one lying prostrate on the floor at the centre. The other four had been placed, one in each corner, apparently in an upright position. All had been wrapped in bark. The central skeleton was very large, measuring a little over seven feet in length. Each wrist was encircled by six heavy copper bracelets. A fragment of the wrapping, preserved by contact with the copper, shows that it was black-walnut bark. A piece of dressed skin, which had probably formed the inner wrapping, was also preserved by the copper. Upon the breast was a copper gorget ; by each hand were three flmt lance-heads ; near the right hand, a small hematite celt and a stone axe. Around the head, neck, and hips were about one hundred small, perforated sea-shells and some shell beads. Upon the left shoulder, lying one upon another, were three sheets of mica from eight to ten inches long, six to seven in width, and half an inch thick. Further discoveries of badly decayed skeletons were made in carrying the shaft downward below the vault, but nothing with which we are at present concerned except the fact that among the articles obtained was the steatite pipe shown in Fig. 8. The significance of this mound lies in the close resemblance it bears, in some respects, to the Grave Creek mound, which, according to the tradition of the Cherokees, was built by their ancestors. But at present no argument is based upon this part of the tradition. This latter giant tumulus is in the form of a regular cone, seventy feet high, and nearly three hundred in diameter at the base. A shaft sunk from the apex to the base disclosed two wooden vaults, — the first about half way down, and the other at the bottom. In the first or upper one was a single skeleton decorated with a profusion of shell beads, copper bracelets, and plates of mica. The lower vault, which was partly in an excavation made in the natural ground, was rectangular, twelve by eight feet, and seven feet high. Placed close together along each side and across the ends of the excavation were upright timbers or posts, which supported others thrown across to form the roof. In this vault were two human skeletons, one of which had no ornaments, while the other was surrounded The similarity in the method of constructing the vaults is marked and peculiar. Wooden vaults are not uncommon; but those partially sunk in a pit, with the sides and ends formed of upright posts, are very rare, and are probably due to some peculiar custom, and indicate tribal identity of the builders. We notice also the presence, with one of the skeletons in each mound, of, copper bracelets and plates of mica. In both a vault is built about midway the height. is somewhat flattened on top, three hundred and eighteen feet in eircumference at the base, and twenty-five feet high. After passing through the top layer of soil, some two feet thick, a layer of clay and ashes one foot thick was encountered. Here, near the centre of the shaft, were two skeletons lying horizontally. These were probably intrusive burials. At the depth of thirteen feet, and a little north of the centre of the mound, were two large skeletons in a sitting posture, with their extended legs interlocked to the knees. Their arms were extended and their hands slightly elevated, as if they were together holding up a sandstone mortar which was between their faces. At the depth of twenty-five feet, and resting on the natural surface of the ground, was one of the so-called "altars," precisely similar to those found in some of the Ohio mounds. This, which was thoroughly traced, was found to be twelve feet long and a little over eight feet wide. It consisted of clay, apparently slightly mixed with ashes, the middle portion basin-shaped, and the margins sloping downwards and outwards; in other words, it was a typical "altar," similar to that shown in Fig. 32, "Ancient Monuments." The depth of the basin in the centre was a little over a foot, and the thickness of the bottom at this point about six inches. On this rested a compact layer of very fine white ashes from one to two feet thick, entirely covering this clay bed. Scattered through them were many water- worn bowlders from three to five inches in diameter, all bearing indications of exposure to intense heat ; also fragments of charred bones, some of which were nearly destroyed by heat. The upper side of this clay bed or "altar" was burned to a brick red. That this tumulus must be classed with the (so-called) "sacrificial mounds" of Ohio, will, it is presumed, be admitted without any objection. As the custom of building these clay structures, to which Messrs. Squior and Davis applied the name "altars," seems to have been peculiar to one class of Ohio mouiul-builders, we have liere one very strong indication that the people who built the mounds of this Kanawha group belonged to the same tribe. Mound 23 is of considerable size, measuring three hundred and twelve feet in circumference and twenty-five in height. It had never been disturbed in any way, and was the most pointed and symmetrical of the group. fully. It was examined by sinking a large central shaft to the bottom. From the top to the depth of fifteen feet, the material passed through was an exceedingly hard, gray mixture, apparently of ashes and clay. At this depth casts of poles and timbers of various sizes were discovered, but all less than a foot in diameter, extending into the western and southern sides of the shaft. These casts and rotten wood and bark continued to increase in amount nearly to the natural soil, which was reached at the depth of twenty-five feet. The dtbris being removed, and the bottom of the shaft enlarged to fourteen feet in diameter, it was ascertained that these timbers had formed a square or polygonal vault, twelve feet across, and some eight or ten feet high in the centre. This had been built up in the form of a pen, the ends of the poles extending beyond the corners. The roof must have been sloping, as the ends of the poles used in making it extended downward beyond the walls on which they rested. On the floor of this vault, which corresponded with the original surface of the ground, were two adult skeletons, the bones of which, though but little decayed, were crushed and pressed out of position. No implement or ornament was found with them. As the earth of this floor did not appear to be the natural soil, the shaft was carried down four feet farther. This revealed a pit, the lateral extent of wliich could not be deter- mined, but which had been dug to the depth of four feet in the original soil. On the floor of this pit, at one side, arranged in a semicircle, were six small clay vaults in the shape of beehives, about three feet in diameter at the bottom, and the same in height. They were made of clay and ashes mixed, very hard, and impervious to water. Possibly they had been allowed to dry before being covered with earth. They were partially filled with a dark, dry dust, apparently of some decayed substance. A few fragments of bones were found in them. In the centre of the space around which these little vaults were arranged, but only two feet below the floor of the large wooden vault, were two small clay-lined cavities about the size and form of the ordinary water-jars from the Arkansas mounds. Possibly they were decayed, unburnt vessels which had been deposited here at the time of burial. The bottom of the pit, which consisted of the natural deposit of yellow sand, was covered with a layer of charcoal and ashes two or three inches thick. This sand appeared to have been heated, from which it is inferred that the burning took place in the pit previous to the formation of the vaults. The work was suspended at this stage, on account of extreme cold weather, but was recommenced the following season by running trenches from the sides into the shaft, and afterward carrying a tunnel in at the base. In one of these trenches, nine feet from the top, occurred a layer of soft earth, in which were numerous fragments of decayed timbers and bark, also casts of logs extending horizontally into the sides of the trench. These, it is presumed from what was afterward discovered, pertained to a wooden burialvault. The tunnel carried in at the base was from the south side, ten feet wide, and eight feet high. For a distance of twenty feet it passed through the hard gray material of which the body of the mound was composed Here the explorers suddenly encountered a deposit of soft earth in len- ticular masses and of various colors, showing that it had been brought from the hillsides and bottoms near by. A short distance from this point they began to find the casts and remains of the timbers of the large central vault, but, before reaching the interior, passed over a small refuse-heap, evidently belonging to an age preceding the date of the building of the mound. As they entered the remains of the vault, they began to find tolerably well preserved human bones, but no whole skeletons. Seeing here indications of the pit before mentioned, the tunnel was carried downward four feet, disclosing five little clay vaults similar to those found on the other side, and, like them, placed in a semicircle. It was now decided to remove and thoroughly explore about one-half of the mound. Many stone implements, some entire but most of them broken, seemingly by the action of fire, were scattered through the hard upper layer, also numerous single valves of mussels which had been used as digging-tools until they were worn from the outside entirely through. There was a marked dissimilarity between the northern and southern sides of this mound, the former being a compact mass of variously colored soils from different points in the vicinity, in alternate horizontal laj'ers. The separate loads of the individuals who carried this earth were plainly defined ; and the different sizes of these small masses indicate that many persons, some much stroQger than others, were simultaneously engaged in the work. With the exception of the imperfect or broken specimens mentioned above, no remains of any kind were found in that portion of the mound above the fire-bed and north of the central shaft, and only two skeletons beneath it; while many interesting finds of implements were made all through the loose, ashy dirt of the southern part, and many skeletons below it. The amount of rotten wood and bark observed, and the positions of the casts of logs and poles, some of which extended downward four feet below the natural surface of the ground, render it probable that there was a wooden structure here twelve feet square and three stories high, or, what is more likely, three structures, one above another. A foot above the natural surface, or twenty-four feet from the top of the mound, was a smooth horizontal layer of sand and ashes, interrupted by two heavy fire-beds. These beds were circular m form, eight feet in diameter, and about ten feet apart. The earth was burned hard for eight inches below the ashes. Under these beds were several human skeletons. No. 1, a medium-sized adult, was extended on the back, head south, arms by the side. This was four feet below the centre of the northern fire-bed. No trace of a coffin was observed, but a rude hoe and a rough lance-head were at the left side. No. 2 was four feet north of No. 1, at the same depth. It lay with the feet toward the centre of the mound, and was enclosed in a kind of coffin formed by leaning flat stones together over the body in the form of an inverted V, and placing a similar stone against the end at the head. A number of relics were with this skeleton, and on the stone at the head was a hematite celt. Two feet north of the head were the fragments of a large clay vessel. No. 3, similarly placed, was four feet under the north edge of the other fire-bed. Some relics were found above the head, and others in a small conical vault near the left side. No. 4, same depth as the preceding, had the head toward the centre of the mound. A small vault near the head contamed several relics of different sorts. natural surface of the ground, resting* on the bottom of the l^it, as were the little conical vaults. Nine vaults in addition to those mentioned were unearthed, — four of them on the bottom of the pit, and five above it. They were similar in form and size to those heretofore described. There was one toward the south side of the pit elongate in form, and not more than two feet wide and two feet. high. Another mound, numbered 30 in the original plat, had a circular pit beneath it, in which were several beehive-shaped clay vaults similar to those heretofore mentioned. The explorer, however, m this case, fails to mention the arrangement or to note particularly the contents, owing perhaps to the pit being partially filled with water, which prevented a thorough examination. By a careful comparison of the discoveries made in the mounds of this Kanawha group with those made in the mounds of the Cherokee section, the reader will observe some striking similarities which cannot be easily accounted for upon any other theory than that of tribal identity or intimate relations of the peoples of the two sections. It is true that we find enclosures in the former locality, and none in the latter, and it is also true that we notice other dissimilarities ; but some changes in customs and works are to be expected where there is a change of location. Necessities, materials, and environments are different, and bring about modifications of customs. These changes are apparent in all parts of the mound area, even where there are good reasons for attributing the works to the same people: in fact, they are sometimes found in a single group. It is true, we cannot assert positively that the little conical clay vaults above described, except in one or two cases, were depositories of the dead, as were the conical bowlder vAults of North Carolina and East Tennessee; yet the very marked similarity in form and size, and correspondence in their arrangement in the tumuli, justify the belief that there was a relationship between the authors of the works of the two sections. Not only are they similar in size and form, but in both localities pits were dug in the original soil, the floor was covered with coals or ashes in some cases, and the vaults built on these and the mound heaped over them. It should also be borne in mind that vaults of this kmd, arranged as here stated, have so far been found only in these two sections. The arrangement in a circle found in the mound in Sullivan County, Tenn., has its parallel in one of the mounds of the Kanawha group. In one was also found the pipe shown in Fig. 8 ; in the other, that shown in Fig. 5. In further corroboration of the theory of relationship between the people of the two sections, may be mentioned the fact that in the mounds of both we find the peculiar basinshaped beds placed in series one above another. Having traced back the tribe by the mound evidence thus far along the traditional line of migration with strong probability of being correct, we are prepared to take another backward step. As will be observed by the careful reader, reliance has been placed in this investigation upon what appear to be indications of peculiar customs. Connection with the group of which the great Grave Creek tumulus forms a prominent feature seems to be established, thus verifying the ancient "oration," or tradition, of which Haywood speaks. Allusion has also been made to the similarity, in some respects, of the works of the Kanawha group to those of Ohio, but there is more to be added on this point. Not only does it appear that it was a custom in both these sections to enclose the bodies of the dead in bark, to bury in wooden vaults, and to form at the bottom of mounds basin-shaped clay masses which have received the name "altars," but also to arrange wooden vaults the same way in the tumuli, and to build other structures similar to each other in form. In confirmation of the statement in reference to the wooden vaults, attention is called to the description by Mr. H. L. Reynolds, in a recent bulletin of the Bureau of Ethnology, of a mound he explored in Paint Creek valley, Ohio. This is the "square truncated mound" shown on No. 1, Plate XXI., "Ancient Monuments," which, by its close proximity to the combined square and circular enclosures known as the "Baum Works," is supposed to bear some intimate relation thereto. question before us. At the time it was measured by Messrs. Squier and Davis it was a hundred and twenty-five feet in diameter, and fifteen feet in height. Since then its annual disturbance by plough and freshet has reduced the height to twelve feet, and increased the diameter to a hundred and forty. The same agencies have likewise destroyed its pj^ramidal form, so that now it resembles an upturned basin. It was composed, for the most part, of clay mottled with black loam, and in some places with patches of a grajnsh, plastic lime. The prominent teature is the evidence that two large wooden vaults, or structures of some kind, had been built here, one aoove the other, as in one of the Kanawha mounds hei-etofore described. Both of these structures had been built of upright posts, five inches in diameter and ten inches apart, forming a regular circle thirty six feet in diameter. The lower circle consisted of a single series, but the upper of two, eighteen inches apart, the outer series standing directly over the posts of the lower structure. Separating the two structures was what the explorer terms "a thin, sagging streak of burnt clay," but which reminds us strongly of the basin-shaped clay beds found in the mounds of East Tennessee and Kanawha valley. Here and there upon its surface were traces of black wood-ashes and a small quantity of white bone-ashes. Horizontal timber moulds, smaller in size than the posts, filled, in places, with charcoal, could be seen distinctly lying against the inside of each line of posts. These appear to have been cross-beams or stays used for braciug-- purposes. On the east side there was a break in each circle, of lliree feet two inches, in which there were no post-moulds. Within each circle, at different depths, and placed without any apparent regularity, were several skeletons Lying on the natural surface of the ground, running from the base of the lower series of posts toward the centre of the circle, were the remains of logs about eight inches in diameter. Directly over tliese timbers was a horizontal layer of decayed and burnt wood or bark, averaging half an inch thick. Notice should also 1)3 taken of the fact that this mound is on the lower level near the creek. — in fact, is one step or terrace below the bridge landing,— and is almost yearly surrounded by w^ater from the overflow. It is true that this mound shows some indication of being comparatively recent: in fact, Mr. Reynolds found in it a small piece of bone which he thought had been shaped with a steel knife. This supposition, if accepted, would seem to be incompatible with the theory that attributes works of this type to the Cherokees. We give the data, however, as they are, and will present our explanation further on. We observe in this mound the somew^liat unusual arrangement of one wooden structure above another, seen elsewhere only in the Kanawha and Grave Creek groups; we also notice that in each case the walls of these structures are forined by standing the timbers upright. There is, however, one particular worthy of note, in which those of the Ohio mound differ from the others; to wit, the much larger size of the former, suggesting the possibility that they were councilhouses, and not vaults. But should this conclusion be adopted, we find parallels in the customs of the Cherokees and mound-builders of the Cherokee district. Mr. Lucien Carr of Cambridge, Mass., explored a mound in Lee County, Va., in which were found indications of a large circular or oval wooden structure. From his descri])tion, as "The mound in question, a truncated oval in shape, stands alone on a gentle slope; and, having been in cultivation for many years, the wear and tear of the plough and the gradual weathering-away of the summit made it impossible to get at its exact measurements. A careful examination, however, showed it to be about three hundred feet in circumference at the base, and nineteen feet in height. . . . On the top was a level space, oval in shape, the diameters being respectively about fifteen and forty feet. At a distance of eight or ten feet from the brow of the mound, on the slope, there were found buried in the earth the decaying stumps of a series of cedar-posts, which, I was informed by Mr. Ely, at one time completely encircled it. He also told me that at every ploughing he struck more or less of these posts, and, on digging for them, some six or seven were found at different places, and in such order as showed that they had been placed in the earth at regular intervals and according to a definite plan. On the top, in the line of the greatest diameter, and nearthe centre of the mound, another and larger post or column, also of cedar, was found. . . . The location and regularity of these posts, and their position with reference to the central column, would seem to show that the summit of the mound at one time had been occupied by some sort of a building, possibly a rotunda or council-chamber, as the ground plan answers to the description of one which Bartram found in the town of Cowe on the ' Tanase ' River among the Cherokees, the very people who formerly held all this section of country." In the mound, and within the circle of posts, several skeletons were found placed irregularly and at different depths, as in the case of the mound opened by Mr. Reynolds. Mr. Carr further remarks that " there were found scattered about everywhere, throughout the whole of the upper half of the excavation, in different places and at various depths, beds of ashes, burnt earth, and charcoal, — usually cedar or chestnut, — sometimes one above and overlapping the other, with an intervening stratum of earth of greater or less thickness." the works of the different sections alluded to. Indications of similar structures were found in some three or four mounds explored by the Bureau assistants in East Tennessee. In one case the series of posts was found at considerable depth, showing that earth had been added subsequent to its erection. Adair says that "every town has a large edifice which with propriety may be called the mountain house in comparison of those already described. But the only difference between it and the winter house or stove is in its dimensions and application. It is usually built on the topof a hill, and in that separate and imperial state-house the old beloved men and head warriors meet on material business, or to divert themselves and feast and dance with the rest of the people." The winter houses referred to were, according to his statement, made as follows: a suflBcient number of strong, forked posts were fixed deep in the ground '"atapropor tional distance, in a circular form, all of an equal height, about five or six feet above the surface of the ground ; above these they tie large pieces of the heart of white oak. . . . In the middle of the fabric they fix very deep in the ground four large pine posts in a quadrangular form." According to Mr. Mooney, — who has furnished the writer with some particulars on the subject in addition to what are found in his paper heretofore mentioned, — on account of the sanctity attached to the location in the minds of the people, a new town-house was usually built upon the site of the old one. The Cherokee town-houses were necessarily located in the immediate vicinity of a stream, and where there was about it a level area. The reasons for this were (1) that the dances were held around and about these public houses, frequently beginning- inside, and ending on the level area around them; and (2) ceremonial bathing formed an important part of the proceedings connected with their sacred dances, such as the green-corn dance and the medicine dance, where the whole body of the performers came out of the town-house to the water, and,' after certain ablutions, returned thereto. It was necessary, therefore, that the building should be near a stream. As the level -areas in their narrow mountain valleys are often overflowed, it is quite probable that in order to place these sacred houses above the floods, they were, as stated in tradition, located on artificial mounds. ''Moreover," adds Mr. Mooney, "the town-house was the depository of numerous ceremonial objects which could not readily be removed in a sudden emergency. And, as it is said traditionally that a sacred fire was kept burning on a peculiar hearth excavated in the centre of the earthen floor, this could not be removed from the hearth-place, and hence some provision for its protection was necessary." Whatever may be the opinion entertained in regard to the relation of the mound-builders of the different sections to each other, or be thought of Mr. Mooney's suggestions, it must be admitted that the above statement gives a satisfactory reason for placing the pyramidal mound of the Baum Works, Ohio, on the lower level near the creek, rather than on the higher level occupied by the square and circle. In confirmation of Mr. Mooney's statement, we find the following in Adair's "History." Speaking of the Cherokees, he says, " Their towns are always close to some river or creek, as there the land is commonly very level and fertile, on account of the frequent washings off the mountains, and the moisture it receives from the waters that run through their fields. Another i^espect in which the Kanawha works resemble those of Ohio is the presence among* them of enclosures, some of which are approximately true circles. There is also among the former a true "hill-fort," located on the top of a bold and partially isolated headland, overlooking the valley for some miles up and down the river. We have now, as before stated, travelled back aloag the path of migration to the Ohio region, the mound testimony agreeing substantially at every step with the traditions. As we now enter a well-known field which has been somewhat thoroughly cultivated by archaeologists, and which is considered, in the minds of many antiquarians, sacred ground, we are aware that we must move with cautious steps, as any attempt to bring forward a new theory in regard to the ancient works of this region is attended with more than ordinary risk. It will therefore be appropriate to introduce at this point some general considerations which have a bearing on the questions at issue. One result of the more recent explorations and study of the ancient works of the mound region is the conviction that the mound-builders were divided into numerous tribes, though belonging substantially to the same culture state, which was of a lower grade than that attained by the people of Mexico and Central America, and apparently somewhat less advanced than that of the Pueblo tribes of New Mexico and Arizona. However, there are no data to justify the belief that they pertained to different "races," using this term in its broad and legitimate sense. This assertion will, of course, be questioned by some of our archaeologists who base their conclusions in reference to this subject on the forms of the skulls. Without entering into a discussion of this question, which would draw too heavily on our space, and is not appropriate at this point, it may be asserted, with the assur- ance of being sustained by the facts, that the study of the forms of mound-builders' skulls has not been productive of any satisfactory results bearing upon the question of races or nationality. This is shown by the remarks of Mr. Lucien Carr, in his paper on the "Crania from Stone Graves in Tennessee," published in the "Eleventh Annual Report of the Peabody Museum:" — "Names, however, are of but little import: the one central fact is to be found in the presence in these graves of skulls, which, after excluding those tabulated as distorted or much flattened, are shown by their measurements to belong to the two extremes of classification, and which cannot be brought into the same group without doing violence to all ideas of craniology. If the terms 'dolichocephalism' and 'brachycephalism' mean any thing, then these two forms of skulls are to be found here, and there is no method of measurement sufficiently elastic to include them both under one head. This fact is by no means new or novel, though it has not been many years since Dr. Morton and anthropologists of his school stoutly maintained the uniform brachycephalic type of crania among all the American aborigines except the Eskimo. Of late years, however, the contrary opinion, so ably advocated by Dr. D. Wilson, has been steadily gaining ground, and to-day there is little hazard in saying that it is generally received. But the evidence furnished by this collection seems to lead still farther; and we are required not only to admit the existence of different forms of skulls, as there well might be in different tribes, but also to conclude that they are to be found among the same people or peoples living under the same tribal organization, much after the fashion in which they are to-day known to exist among the composite peoples of our great commercial cities. This is hardly in accord with the opinion generally held as to the purity of race in prehistoric times ; but it seems impossible to avoid the conclusion, if it be admitted that the fact that THE CHEROKEES IN PRE COLUMBIAN TlilES. 67 these skulls were found buried together indiscriminately in the same style or set of graves in the same mound, and so far as we can judge at or near the same time, is any proof that they belonged to people of the same tribe and race." It will be seen from this conclusion of one best qualified to express an opinion on this subject, that a classification of the mound-builders upon the forms of the skulls is not only unsatisfactory, but is misleading and valueless. That the people found inhabiting the continent at the time of the Columbian discovery may have been, and probably were, derived from different races, is not denied. Possibly the mound-builders of the section herein designated the "mound region' may have been derived from different races; but, if so, this cannot be determined by the crania found in the mounds of the Mississippi valley. Indications of tribal peculiarities, of variations in local customs depending on environment, and perhaps traces even of customs peculiar to certain stocks or families, are observed in the ancient works of the region indicated, but nothing whatever to suggest different races. This is a bold and venturous statement to make, in view of what has been published on this subject; nevertheless the writer feels justified in making it, and believes that the data, when thoroughly studied, will sustain him. The evidence of division into tribes is found in the numerous indications of intertribal warfare, such as the works of defence of various kinds met with in different sections. For instance, there are the hill-forts of Ohio, of which Fort Ancient is a well-known example. No one has ever doubted that these were constructed for defence. Nor is it likely the other enclosures, such as the circles, squares, and octagons, would have been ascribed to any other object but for the introduction of the theory of a semi-civilized, mound-building race, with its priesthood and religious ceremonies. Assume that the authors were the ancestors of the Indian tribes found inhabiting the country, and the idea of this overpowering religious influence vanishes at once. The enclosures of New York, Michigan, Kentucky, Tennessee, south eastern Missouri, and the Gulf States, are admitted to be defensive works. In addition to these, there are in many places defensive walls and embankments across projecting spurs, peninsulas, and river bends. Village sites are also often found in positions which could have been selected for no conceivable reason except that they might be easily defended against attack. The only reasonable explanation of these facts, and of the evidences of diflPerent customs found in the mounds, is that the mound-builders consisted of different tribes. Even in the comparatively limited area of Ohio are found abundant evidences of the presence of different tribes, and of successive occupation by different peoples. The same thing is true also of the areas embraced in eastern Iowa, Wisconsin, Illinois, Indiana, and Kentucky; but, on the other hand, western New York, a strip along the lake border of Ohio, and the Cherokee region of East Tennessee and western North Carolina, appear to be exceptions to this rule. As the connection indicated between the works of the Kanawha valley and those of Ohio relates primarily to the sepulchral and so-called " sacrificial mounds," and secondarily to the geometric enclosures of the type found in the Scioto valley, attention is called to the latter. Forty years ago, Messrs. Squier and Davis, while admitting that some of 'the enclosures of this State were built for defence, advanced the theory that a large number of the earth- works were designed for sacred or religious purposes, and places for performing superstitious rites, — a view which has generally been adopted by subsequent writers. That this theory was based upon a preconceived notion held by these authors, is apparent from the following statement in " Ancient Monuments : " "We have reason to believe that the religious system of the mound-builders, like that of the Aztecs, exercised among them a great, if not a controlling, influence. Their government may have been, for aught we know, a government of the priesthood, — one in which the priestly and civil functions were jointly exercised, and one sufficiently powerful to have secured in the Mississippi valley, as it did in Mexico, the erection of many of those vast monuments which for ages will continue to challenge the wonder of men." Dr. Daniel Wilson not only takes the same view in his "Prehistoric Man," but expands and emphasizes it. He even goes so far as to assert that the earth-works of the Iroquois present, in some respects, a greater contrast to those of the mound-builders (of Ohio) than the latter do to the elaborate architecture of Mexico and Yucatan. "They form groups," he continues, "of symmetrical enclosures, square, circular, elliptical, and octagonal, with long connecting avenues suggesting comparisons with the British Avebury, or the Hebrideau Callernish ; with the Breton Carnac, or even with the temples and sphinx avenues of the Egyptian Karnak and Luxor." If we lay aside all preconceived notions of a highly cultured race of mound-builders with a priestly hierarchy, and study these remains in the light of such data as we possess, instead of looking at them through the halo of a finely wrought theory, the inappropriateness of such comparisons becomes apparent. What shall we say of the attempt to compare the dirt walls of these groups of combined circles and squares with the great temple of Karuak, termed by Fergusson " the noblest effort of architectural magnificence ever produced by the hand of man "? of likening the simple earthen parallels, thrown up perhaps with wooden spades, to the avenue of crio sphinxes, and the magnificent, columned hall of the Egyptian temple ? In what respect do these earth-works of the mound-builders resemble the palace at Palenque, or Casa del Gobernador and House of the Nuns at Uxmal? It is only necessary to put the question: the reply is self-evident. Yet the writer just quoted, who may be taken as the leading representative of the school to which he belongs, sees, in some respects, less contrast between these two classes of structures than between the earth- works of the Iroquois and those of the mound- builders of Ohio. to be for defensive purposes, and are of a character conformable to savage life. And in reply to Dr. Wilson it may be truly affirmed, that if we compare the larger work on Plate XIX. of " Ancient Monuments '' — which is in the immediate vicinity of the celebrated " Mound City," Ross County, O. — with that on Plate II. of Squier's "Aboriginal Monuments of New York," the similarity is so marked (except in size) that one might be substituted for the other without bringing into, or omitting from, the former group any important character. Yet here is what was considered by the authors of " Ancient Monuments " pre-eminently the sacred or religious city of the Ohio mound-builders; and, what is worthy of mention, the accompanying enclosure, so like that of New York, has a central mound, which was examined by Messrs. Squier and Davis, and pronounced by them " clearly a place of sacrifice." A number of such general resemblances between the works of the two sections could be pointed out; yet it is admitted that the two classes of remains bear evidence of being the works of ditferent tribes, but not of different races, or of peoples in such widely different culture states as to justify Dr. Wilson's extravagant statement. The complicated group, consisting of circles, a square, octagon, and parallels, at Newark is unquestionably the most noted, as well as the most extensive, of its class in the mound section. As these cover an area estimated at two miles square, what, it may well be asked, must be the estimate of the size and population of the village that required such an extensive system of works devoted to religious services and superstitious rites ? The great circle at Avebury, England, the most extensive of the so-called druidical structures of Europe, embraces only about thirty-six acres ; while here is an octagon enclosing fifty acres, one circle including twenty, another thirty, and a square embracing twenty acres. The race-track, buildings, and other appurtenances of the Fair Association of a county containing probably a hundred thousand inhabitants are enclosed in a single one of these circles. If these were but places where games were held and religious ceremonies performed, where are we to find the indications of the immense village that required such vast amphitheatres ? It is remarkably strange that the mound-builders of central and southern Ohio alone, of all the ancient peoples of the mound region, should erect such extensive structures devoted to religious observances ; that here alone the priestly influence should have been sufiiciently powerful to produce such results. How is the development of this sacerdotal element in this limited area to be accounted for? It is true that a few of these enclosures are remarkably correct geometrical figures, and present a puzzling question to the archaeologist; but the usual explanation, that the authors were a people in a much higher state of culture than the Indians, serves but to increase the difficulty. On the one hand, it is only necessary to suppose that they were built for defence, and that the Indians of a certain tribe and era had learned the art of laying off correctly circles of large size, and the problem is solved. But, on the other hand, the supposition of a highly cultured race, capable of forming these figures by means not within the reach or capacity of the more advanced Indians, introduces a host of still more troublesome questions. That the ancient works of the Southern States and of New York are to be ascribed to the Indians, is too clearly established by historical and other evidence to be longer denied ; and it is even admitted, that associated with the prehistoric monuments of the valleys of the Muskingum, the Scioto, Brush Creek, the Little Miami and Big Miami, are mounds and works of later times, some of which were made by the historic tribes or their immediate ancestors. Notwithstanding this supposition of a much earlier occupation by a veritable mound-building people of advanced culture, there are works here ascribed to this people which present no indications of greater age than some of those attributed to Indians. How is this to be accounted for on the latter theory? The fact, well known to all archaeologists, that minor works of art are found in these typical monuments of the same character as those obtained from mounds attributable to the Indians, presents another question difficult to answer on this theory. The "Monitor'" pipe, or pipe with broad base running out in front and behind the bowl, is considered typical of the people who built the "sacrificial mounds" and "sacred enclosures" of Ohio; yet, according to Adair, the Cherokees made pipes of precisely this i^attern, as he says "the fore part of each commonly runs out with a sharp peak, two or three fingers broad and a quarter of an inch thick, on both sides of the bowl lengthwise; they cut several pictures with a great deal of skill and labour." This seems not only to connect the builders of these typical Ohio works with the Indians, thus presenting a difficult problem for the advocates of the above theory to solve, but forms another strong link in the chain of Cherokee history we are trying to follow. There are other difficulties in the way of this hypothesis which our limited space will not permit us to present. There are other questions, however, relating to these enclosures, which require notice here, as they have some bearing on the theory advanced in this paper, and must affect to some extent the conclusions reached. It is believed that the evidence presented will be accepted as sufficient to justify the supposition that the Tallegwi of tradition must be identified ^itli the Cherokees, and that they formerly lived in the Ohio valley. Having shown that the people of this tribe built mounds in their historic seat, and were in all probability the authors of the Kanawha and Grave Creek works, it is reasonable to conclude that they built mounds and constructed other works during their resi- dence in Ohio. If this be admitted, their identification with the Tallegwi would indicate that, during their long contest with the Dela wares and Huron -Iroquois, they built defensive works, as it is stated in Heckewelder's version of the tradition, that "the enemy [the Tallegwi] fortified their large towns and erected fortifications, especially on large rivers and near lakes, where they were successively attacked, and sometimes by the allies" (the Delawares and Iroquois). Although it is to be presumed that this is somewhat colored to conform to the interpretation of the narrator or author, there can be little doubt that the Tallegwi erected defensive structures in order to resist their enemies. This is probably implied in the Walam-Olum, where it is stated that "the Talega towns were too strong." If the enclosures are defensive works, they present nothing incompatible with the theory herein advanced, but rather tend to confirm it. Even supposing they were intended for sacred or superstitious uses, they must have been constructed for the purpose of defending the gathered assemblies from sudden attack by enemies. Take, for example, the Baum Works shown in Fig. 1, Plate XIX., of the "Ancient Monuments," and copied in our Fig. 9. For what purpose were the walls built, except for defence? Is it to be supposed that they were intended solely as sittingplaces for the spectators? Those around the square alone would have seated eight or ten thousand persons, and the wall of the circle as many more; yet the remains present no indications of an extensive village. We may also ask, with good reason, why one enclosure was square and the other circular, when the builders must have known that the latter afforded the better chance of observing the ceremonies. Are we to assume that different enclosures were made for the different kinds of rites and games? The only reasonable conclusion, even under the supposition that these were "tabooed" or sacred places, is, that the walls were built for defence, and, as Atwood judged from bis discoveries, were stockaded. But this brings up tbe inquiry, ''Why were the sacred grounds enclosed, while the village remained without defensive walls?" position that they were defensive works of people in the same culture grade as the Indians simplifies the problem, and enables us to present at least a partial explanation which is consistent with other data susceptible of interpretation. Referring again to the Baum group shown in the figure, what is more likely than that the square enclosed the village, and the circle the maize-field? On the pyramidal mound was the council-house, within and around which the ceremonial dances were held; and near by was the creek in which the ablutions were performed. The council-house in this case was not in the village; the latter being built near the hills, contiguous to cool springs of water, thus rendering the distance from it to the creek too great for the convenience of the bathers. The writer is aware that this explanation will not apply in full to all the enclosures of this type, as the conditions are not the same in all the localities; and it is more than likely that the customs of the villages varied to some extent, although pertaining to the same tribe. The probable differences in the age of the villages, and the modifications of customs, are also to be taken into consideration ; nevertheless this supposition gives us a key that will unlock most of the mystery of these works. They are in most cases located near a stream, and consist of a square or octagon with its gateways and protecting mounds surrounding the village, and a circle enclosing the corn-field. As a rule, the small circles, which may have been places of amusement and ceremony, are outside of the large enclosures. Even at Fort Ancient, which no one doubts is a defensive work, the supposed race-track and principal mounds are outside, though the crescent, in front of which the ceremonial rites were performed, is within the fort. In some cases, as at the Liberty Township Works ("Ancient Monuments," Plate XX.), a special arrangement seems to have been made for this purpose. Here we see a connected third circle, much smaller than the other two, in which is a crescent and mound; there is, however, a little exterior circle. We notice here that the square or village site is near the bluff from whence springs issue. are next the stream, as there were no springs in reach. The complicated group at Newark, of course, presents features difficult to explain; but it is apparent that there were two villages, probably established at different times, but both occupied from the time the latter was built until the whole was abandoned. The octagon is near the creek, but its position was doubtless selected on account of the spring near its northern corner. The southern circle, E, was possibly a place devoted chiefly to ceremonies and games. One line of parallels seems to have been a passageway from one village to another. It is apparent from their courses and the topographical features of the area that none of these guarded ways were intended for race-tracks. That the small, circular enclosure F, known as the "Observatory Circle," was not sufficient in extent to supply the villages with bread, is admitted : hence it was necessary to assume that there were unenclosed fields, probably on the land north of the group, between the parallels running east and west, and in the area east of the pond. It is possible that the space between the two lines of parallels, running east and west, was partially occupied by dwellings, especially that portion on the upper, level land. These suggestions are of course largely speculative; nevertheless, if there be any truth in the tradition of the Tallegwi, it is probable that here they made their first determined stand after defeat in open battle. The people of other villages, not enclosed, probably fled thither, and joined in erecting fortifications and defensive walls. Be this as it may, it is apparent that they belong to the same type as those in the Scioto and Paint Creek valleys, and may be ascribed to the people who built the latter. That they were defensive seems to be established by the considerations presented, and others which might be urged did space allow us to offer them. It is apparent to any one not biassed by a preconceived theory, who will study these works carefully, that their characteristics are essentially aboriginal: in other words, there is nothing in their form or construction contradictory to the theory of their Indian origin, except it be the single fact that a few of them approach very nearly to true geometrical figures. That it was a custom among the Indians north and south to build circular enclosures and forts, is fully attested by the historical records; it is also known that some of the Indian forts in the northern section were polygonal, especially those built by the Iroquois tribes. Numerous instances can be cited where villages were surrounded by fortifications in both these forms. The suggestion that the circles adjoining squares were built around maize-fields is not original with the writer, as ^ it had already been presented by Lewis H. Morgan, in his " Houses and House Life of the American Aborigines." He remarks, that " with respect to the large circular enclosures, adjacent to and communicating with the squares, it is not necessary that we should know their object. The one attached to the High Bank Pueblo contains twenty acres of land, and doubtless subserved some useful purpose in their plan of life. The first suggestion which presents itself is, that as a substitute for a fence it surrounded the garden of the village in which they cultivated their maize, beans, squashes, and tobacco. At the Minnitaree village a similar enclosure may now be seen by the side of the village, surrounding their cultivated land, consisting partly of hedge and partly of stakes." Whether these dirt walls were mere supports to stockades is a question not yet settled; nevertheless it is probable they were surmounted by stakes, or supported a wooden fence or screen of some kind. The fact that the ditch is here usually on the inside cuts but little 6gure in the discussion, as we find this to be the case in many works which are undoubtedly of a defensive character, as Fort Ancient, and the circular enclosure in Iowa shown in Plate II., "Fifth Annual Report of the Bureau of Ethnology." In fact, this was consistent with the Indian mode of warfare. Long tells us, in the account of his expedition, that sometimes they would hastily dig a trench, throwing the dirt on the danger side, and thus form a defensive barrier. Whether the hill-forts are to be attributed to the authors of the circles and squares is doubtful: in fact, the indications appear to lead to the opposite conclusion. Certainly tliere is no reason for supposing that Fort Ancient, Fortified Hill, and other works of this character in the Miami valleys, were built by this people. The writer is inclined to the belief that they are the work of the Shawnees, but cannot undertake at this time to give his reasons for this opinion. As the so called ''altars" form a link in this historic chain, we may as well remark here that the names "sacrificial mounds" and "altars," implying human sacrifice, have been brought into use without even the shadow of evidence therefor. As Morgan has truly observed, "there is no propriety in the use of either of these terms, or in the conclusions they would force us to adopt. . . . These clay beds were not adapted to the barbarous work." Possibly they may have been places where prisoners were burned, which was the chief sacrifice ofiPered by Indians. The basin-shaped clay beds of the Kanawha and East Tennessee mounds seem to have grown out of them, and their uses were probably gimilar. The close agreement between the testimony of the mounds and the traditions of both Cherokees and Dela wares is somewhat remarkable, and justifies us in believing that they have a basis of truth. We are at least warranted in accepting the theory that the first-named people formerly dwelt in Ohio, and built some of the noted monuments of that State. The number and character of the defensive works indicate that there was a long contest and an obstinate resistance on the part of the original inhabitants. The geographical position of these works makes it apparent, as has often been remarked by writers on this subject, that there was a pressure by northern hordes which finally resulted in driving the inhabitants of the fertile valleys of the Scioto and Muskingum southward. Some of these writers take it for granted that they fled through Kentucky and Tennessee into the Gulf States, and became incorporated with the tribes of that section. If this be assumed as correct, it only tends to confirm the theory of an Indian origin. A study, however, of the pipes alone, makes it evident that this conclusion cannot be maintained. That the moundbuilders of Ohio made and used pipes is proven by the large number found in the tumuli, and that they cultivated to- bacco may reasonably be inferred from this fact. Although varied indefinitely by the addition of animal and other figures, the typical or simple form in use among them appears to have been that known at present as the "Monitor" pipe, shown in Fig. 68, "Ancient Monuments," and Fig. 177, Rau's " Archaeological Collection of the National Museum." The peculiar feature is the broad, flat, and slightly curved base or stem, which projects in front of the bowl to an extent equal to the perforated end. This form is so peculiar that it must be considered ethnic or local. However, as will be seen by reference to the "" Proceedings of the Davenport Academy of Natural Sciences" and the " Smithsonian Re- port for 1882," it is found in eastern Iowa and northern Illinois, and appears to be the only form found in that region : hence it cannot be considered local. Now, it is somewhat remarkable that nearly all the pipes of this form and the modifications thereof, ending in the modem form shown in Fig. 6, are found in a belt commencing in eastern Iowa, running thence through northern Illinois, eastern Indiana, southern Ohio, and thence bending south through Kanawha valley, and ending in western North Carolina. The first modification is seen in Fig. 8, and found in Ohio, the Kanawha valley, and North Carolina; the second, shown in Fig. 10, is found in Ohio and the the North Carolina mounds. Although specimens, chiefly of the first modification, have been discovered in New York and Massachusetts, it is not known that the " Monitor " or any of its manifest modifications prevailed, or was even in use, at any point south of the belt mentioned. Pipes in the form of birds and other animals are not uncommon, as may be seen by reference to Plate XXIII. of Jones's "Antiquities of the Southern Indians;" but the platform is a feature wholly unknown in the Gulf States or middle Tennessee, as are also the derivatives from it. This fact stands in direct opposition to the theory that the mound-builders of Ohio fled southward across Kentucky and Tennessee, and became incorporated with the tribes of the Southern States, as it is scarcely possible that such sturdy smokers as they must have been, would have abandoned all at once their favorite pipe. The change, as it was in the other direction, would have been gradual. This evidence, however, has a very significant bearing on another point; for, if the testimony introduced justifies the theory advanced in this paper, then it is probable the Cherokees entered the immediate valley of the Mississippi from the north-west, striking it in the region of Iowa. This supposition is strongly corroborated, not only by the presence of the "Monitor" pipe and its derivatives along the belt designated, but also by the structure and contents of many of the mounds found along the Mississippi in the region of eastern Iowa and western Illinois. So striking is this resemblance, that it has been remarked by explorers whose opinions could not have been biassed by this theory. Mr. William McAdams, in an address to the American Association for the Advancement of Science, remarks that "mounds such as are here described, in the American hot- toms and low lands of Illinois, are seldom found on the bluffs. On the rich bottom-lands of the Illinois River, within fifty miles of its mouth, I have seen great numbers of them, and examined several. The people who built them were probably connected with the Ohio mound-builders, although in this vicinity they seem not to have many earthen embankments or walls enclosing areas of land, as is common in Ohio. Their manner of burial was similar to the Ohio mound-builders, however, and in this particular they had customs similar to mound-builders of Europe." Two mounds in Calhoun County, 111., one of which was opened by Mr. McAdams and the other by one of the Bureau assistants, presented the clay mass in the regular form of the Ohio "altar." But what is strange, though not without parallel, is the fact that we find the structure and contents of some of the eastern Iowa mounds similar to what is seen in the Cherokee district of North Carolina and East Tennessee. Here, among other things, are seen the cubical jjiles or "altars" of unhewn stone with bones about them, precisely as found in some of the North Carolina burial-places, pottery bearing a strong resemblance to that of Ohio, and mounds with stone strata. A mound in Franklin County, Ind., described and figured by Mr. Homsher in the "Smithsonian Report for 1882," presents features strongly resembling those observed in tumuli attributed to the Cherokees. Here we see the rectangular heaps of cobblestones like those in the North Carolina mounds, and stratification and arrangement of skeletons as in the East Tennessee mounds, also the stone stratum observed in the Iowa works. Having now traced the tribe back to the western boundary of the mound region, we are prepared to take a glance downward along the line of migration, bridging by deduction such breaks as appear in the testimony. ited numbers, slowly extending their settlements or shifting up or down the stream between the mouth of the Des Moines River and what is now the northern boundary of Iowa. If we may judge by their works, it would seem that it was necessary only at this northern point of their extension to fortify against enemies. A suggestion as to who these enemies were will be offered a little further on. It is impossible to give any satisfactory estimate of the length of time they occupied this locality; it was long enough, however, for them to acquire certain peculiar customs, some of which were not wholly dropped until they came into contact with the whites many centuries later. It is possible that here they began to build mounds, but explorations westward of this area have not been carried on to a sufficient extent to speak with certainty on this point. It was here, no doubt, that the platform pipe with animal figures came into use. The ornamentation of their pottery, and the forms of their vessels, suggest the possibility of contact or intercourse with southern mound-building tribes. There is also abundance of evidence that they had acquired the art of manufacturing cloth, and were acquainted with copper. The evident admixture, however, in these mounds, by intrusive burial, of articles of more recent times with those of the original burials, renders it somewhat difficult to decide positively as to the advance made in art by this people while residing in this locality. After passmg to the east side of the river, it appears that they moved some distance farther to the south, their utmost limits in this direction being in Calhoun County, 111. The reason for this may have been the presence of the same enemies who opposed their northward movement on the opposite side of the river. Of course, without the knowledge of all the mound testimony, any attempt to descend into details of the movements of the tribe would carry us wholly into the realms of speculation. All that the mounds teach us in regard thereto is the extent of the area occupied, and the encroachments of works of other types which may or may not be contemporaneous. It is a fact perhaps worthy of notice, that, while the remains of the effigy-builders on the west side of the river reach but little south of the fortified point before alluded to, they are found on the Illinois side as far south as the latitude of Peoria. Passing on eastward, we next find indications of their presence in eastern Indiana, whence it seems they gradually moved into central Ohio, finding, as we judge from some works along the southern border of their line of migration, some opposition. Their stay in this attractive region must have been long, and for most of the time a period of peace. The reasons for this conclusion are, first, the indications of the growth of the tribe, judging by the number of works and the statements in the Delaware tradition, which imply that it had spread northward near to the lakes; and, second, the localities of the defensive works, which indicate that their chief contest was with a northern foe. If the latter supposition be correct, it would seem to imply that until this contest they had not found it necessary to build defensive structures. These, of course, are speculations, and only advanced as such ; but there is one thing in relation to their removal from this region for which there appears to be historical, traditional, and mound testimony, and which has some bearing on the preceding suggestions. This is, that their departure was in separate bodies, and at intervals of considerable length. That some were in their historic seat before the time of De Soto's expedition, and possibly as early as the thirteenth century, has been shown. On the other hand, we have the statement of Bishop Ettwein, in a communication made to Gen. Washington, that the last of them did not remove from the region of Ohio until about the year 1700. We also find in the mounds of Ohio indications of intercourse with people residing in the mountain region of North Carolina. It has been objected, with some show of reason, that the theory advanced in this paper cannot be correct, because there are no such enclosures in North Carolina and East Tennessee as those in Ohio, because no true "Monitor" pipes have been found in the mountain section, and because no engraved shells have been found in the Ohio mounds. The first of these objections has already been alluded to; but we may add, that this people found themselves able, in their mountain fastnesses, to protect themselves against all their Indian foes without erecting artificial defences. The second objection, as we have already shown, is answered by a somewhat remarkable historical statement by Adair. When he speaks of pipes "full a span long, with the fore part commonly running out with a short peak, two or three fingers broad and a quarter of an inch thick, on both sides of the bowl lengthwise,''^ he can refer to no other known pipe than the "Monitor," or the very slightly modified form with straight base, found also in the Ohio mounds. As the author quoted wrote before any specimens had been unearthed from mounds, he must have seen in use that of which he speaks. This, we repeat, is somewhat remarkable, and forms a link connecting the Cherokees and mound-builders of Ohio sufficient to warrant the theory here advanced, were there no other evidences bearing on the question. The fact that no engraved shells bearing designs like those found in North Carolina and Tennessee have been discovered in Ohio forms no objection to the theory. Arts and customs are not always ethnical or tribal: some are acquired by contact and intercourse with other tribes. The custom of carving and wearing these shell gorgets did not originate with the Cherokees, but was acquired by contact with other tribes, after they had reached their southern home. These objections do not militate against the theory, which is established on too broad a basis of facts and resemblances to be set aside by its failure to account for all the discoveries made. Investigations in regard to the origin and use of these ancient monuments must be made chiefly by comparisons and deductions, as historical evidence is in most cases wanting, and absolute demonstration impossible. Attention was called in the first part of the paper to the conclusion reached by linguists, that the language of this tribe belongs to the Huron-Iroquois family, thus necessitating the inference that we must look to the same locality for the origin of both. This throws a faint ray of light on the history of our tribe preceding their arrival on the banks of the Mississippi. But before attempting to follow this slender clew, attention is called to some general considerations drawn from a comprehensive study of the monuments of the mound section. In entering upon a discussion of the routes by which the mound-builders came into this section, an examination of the general distribution of the prehistoric remains is necessary. At present we are concerned only with what may be considered the boundaries thereof. Although the data are not sufficient to determine these limits accurately, enough has been ascertained to indicate what will probably be found in the end to be true. Limiting the consideration to what are usually classed as the genuine works of the mound-builders, the eastern boundary extends from central New York along the Appalachian range to Virginia, diverging thence south-eastward so as to strike the Atlantic coast in South Carolina. The Gulf coast, west of Florida, appears to be generally bare of mounds (with the exception of shell and refuse heaps) for some distance toward the interior. On the north, the lakes and Rainy River form a tolerably well defined border, but west of the source of the Mississippi there is a northward exten- sion into Manitoba which has not been fully traced ; yet the indications are that but few ancient works will be discovered north of the Assiniboin region. Most of the mounds of this section which have been explored appear to be somewhat recent, though others bear evidence of being contemporaneous with the works of Wisconsin. On the west the plains appear to form the boundary from North Dakota to Texas, a line of recent works along the Missouri River forming the only exception, so far as known. The statement frequently made, that the works of the mound-builders continue across Texas into Mexico, appears to be without any foundation ; for up to the present time but few have been discovered south of Red River, except in the eastern part of Louisiana. So far, therefore, as the facts ascertained are concerned, the distribution of the works of the mound-builders affords but little evidence on which to base a theory in regard to the lines along which the authors of these works entered the mound section. The exceptions, if any, are to be found in Florida and the North-west. But this statement must not be taken as indicative of a theory held by the writer, for he is not inclined to the opinion that the mound-building element, except possibly that of southern Florida, entered through this peninsula. Although he has reached no settled conclusion on this subject, he has been inclined to look more to the north-west and west for the lines of immigration than elsewhere, but freely confesses that he finds but little in the works along the border on which to base any theory. While this is true considering the section as a whole in its relation to the other comprehensive archaeological divisions of the continent, there are, on the other hand, decided indications of movements within the mound section. The works of the effigy-mound district, confined chiefly to the southern half of Wisconsin and the immediately adjoining sections, are peculiar, and formed a puzzling factor to those holding the theory of one great nation of moundbuilders. The study of these appears to lead all those who have devoted attention to them to the conviction that the more elaborate forms, are, as a rule, older than the simpler ones. Following up the slight clew thus afforded, and using the faint rays of light thrown on the history of the builders by the distribution of the mounds, we are led to believe that their entrance into the district was most likely at its southwestern corner, about what is now the north-eastern part of Iowa, and that the area longest occupied was the southwestern portion of Wisconsin. The indications are, that they shifted back and forth between the Mississippi River and Lake Michigan, and finally made their exit at the northwestern boundary of the State, a part going as far north as southern Manitoba. From there they at length passed southward into Dakota, where the mounds fade out, and the presence of the descendants of the builders— who, we are inclined to believe, pertain to the Dakotan stock — is indicated only by surface figures Another movement, traced by certain classes of works and vestiges of art which we ascribe to the ancestors of the Cherokees, was that already mentioned, extending from eastern Iowa through Illinois, Indiana, Ohio, and West Virginia, to the mountain region of North Carolina and East Tennessee. A third line is indicated by certain types of prehistoric remains extending from Michigan, along the southern shore of Lake Erie, into New York; but nothing has been found in these remains by which to determine the direction of the movement. There is little doubt, however, that the works along this line are attributable to one or more tribes of the Huron Iroquois family. nessee, to the north-east corner of Georgia; the area of chief occupation, and position of longest quietude, being that portion of the Cumberland valley in middle Tennessee. The works along this belt, which we attribute to the Shawnees, consist chiefly of stone graves of a particular type, and mounds; they fail, however, to give any satisfactory evidence as to the direction of the movement. Nevertheless there are, along portions of the line, some evidences of a shifting back and forth ; and the minor vestiges of art prove beyond question that the authors were contemporaneous with the builders of the mounds of East Tennessee and North Carolina. Although the banks of the Mississippi are lined with prehistoric monuments from Lake Pepin to the mouth of Red River, showing that this was a favorite section to the ancient inhabitants, yet a study of these remains does not give support to the theory that this great water highway was a line of migration during the mound-building age, except for short distances. It was, no doubt, a highway of traffic and war-parties, but the movements of tribes were across rather than up and down it. We do not assert this as a theory or simple deduction, but as a fact proven by the mounds, whatever may be the theory in regard to their origin or uses. The longest stretch, where those apparently the work of one people are found on one bank, is that from Dubuque to the mouth of the Des Moines. As we move up and down, we find repeated changes from one type to another. In addition to this, are the intermingling of other types, and indications in most places of successive occupation by difiFerent tribes. It is a very natural supposition that the people first reaching the bank of this broad stream, or of any of the other large streams of our country, would continue their course along it, but the mounds give no support to the theory. mound-building people is one of permanency: hence their movements are governed largely by pressure from other tribes, and not by choice. No evidence has yet been found in the mounds pointing to the first comers into the section. On the contrary, all the evidences of migration point at the same time to pressure or obstacles in one or more directions. For example: the mound-builders of Wisconsin must have found some obstacle which prevented them from continuing their course eastward around the southern end of Lake Michigan, while the pressure which drove them from the area they had occupied so long seems to have come from the north-east. The singular course of the people who buried in the stone graves south of the Ohio, whether moving eastward or westward, can be explained only on the theory of the presence of other tribes to the north and south ; and this is probably true, as has been suggested, in regard to the people who travelled from eastern Iowa to Ohio. Indications of movements are found in other portions of the mound section, but those mentioned are all which have any immediate bearing on the subject under consideration at present. Returning now to the point where we paused in our journey backward along the pathway of the Cherokees, the inquiry arises, ''From what point, or along what line, did they come to their halting-place on the banks of the Mississippi?" As has already been stated, it is now conceded by linguists that their language is an offshoot of the HuronIroquois family, — a relationship long ago surmised by Dr. Barton and Mr. Gallatin. We may therefore, in answer to the above inquiry, though in a somewhat broader sense than given, adopt the language of Mr. Horatio Hale in speaking of the more closely allied branches of this family: "There can be no doubt that their ancestors formed one body, and indeed dwelt at one time (as has been well said of the an cestors of the Indo-European populations), under one roof. There was a Huron-Iroquois 'family pair' from which all these tribes were descended. In what part of the world this ancestral household resided is a question which admits of no reply except from the merest conjecture." He adds, however, "that the evidence of language, so far as it has yet been examined, seems to show that the Huron clans were the older members of the group; and the clear and positive traditions of all the surviving tribes, Hurons, Iroquois, and Tuscaroras, point to the Lower St. Lawrence as the earliest known abode of their stock." If the evidence presented in this paper be considered sufficient to justify the belief that the Cherokees entered the Ohio valley from the west, we are, then, forced to one of two conclusions, which may be stated hriefly as follows: first, that this tribe, breaking away from the family in its eastern home, wandered westward, passing between Lake Superior and Lake Huron into what is now Wisconsin, and onward to the border of the plains, turning thence southward to the point on the banks of the Mississippi where we first find them; or, second (which is far more likely), the original stock was at one time in the distant past located in the region north-west of Lake Superior, and while here the Cherokees separated from their brethren, and moved southward to the banks of the Mississippi, while the latter, being pressed onward, moved eastward, north of the Lakes, to the banks of the St. Lawrence. If this supposition accords with what really was the direction of the movement, then it is highly probable, that, when they reached the Ottawa River, a portion followed down its course, while others turned southward into what is now Ontario, and were in that section when the Lenape appeared on the scene. and reasonable. The eWdence presented by Mr. Hale in the "Iroquois Book of Rites" leaves no doubt that the earliest known seat of the Huron-Troquois family was on the Lower St. Lawrence; but it is scarcely presumable that their first appearance on the continent was in this eastern region. It is more likely that they had reached this point from some western section, and as they increased in numbers were forced to partially retrace their steps. Although it is apparent that the authors of the ancient works east of the Rocky Mountains were substantially in the same culture state, and belong to the same race in the broad sense, yet there are some reasons for supposing (if we include the ancient works of New York under the general term "mounds") that the custom of building mounds originated independently in some two or three different sections. This is inferred from the fact that there appear to be at least three comprehensive classes of works: first, those of the Huron -Iroquois region; second, those of the Dakotan district; and, third, those of the southern section. These are not limited by ethnic lines, as the people who built the works along what we have designated the Cherokee and Shawnee belts probably derived the custom from the southern mound-builders. The southern Dakotans, as the Quapaws and cognate tribes, also built mounds of the southern type. It is possible, however, that future discoveries in the north-west and south west may throw additional light on these questions, and modify the views here advanced, which are based, as a matter of course, only on the data so far obtained. The attempt to estimate the time that has elapsed since the arrival of the Cherokees on the banks of the Mississippi (assuming the theory advanced to be correct) or since their meeting with the Lenape must be almost wholly conjectural. Mr. Hale says the time which has elapsed "since the Tallegwi were overthrown" is variously estimated, but that the most probable conjecture places it at a period about a thousand years before the present day, which would carry it back to the ninth centur}^ Basing the estimate on the traditional evidence, for mound evidence gives but little aid in this respect before contact with the whites, it would seem to be more nearly correct to place the event in the eleventh or twelfth century. How long they had remained in this region when the war with the Lenape occurred is a question that must be left wholly to conjecture until other data than those we now possess are obtained ; but it must have been a stay of some centuries, during which, as before said, they had lived in comparative peace. There are some reasons for believing that during this time another tribe had pushed its way up the Ohio River to the region about the mouth of the Miami. It is even probable that bands had crossed to the north side of the Ohio, and established themselves along the banks of the two Miamis. These I am inclined to believe, as heretofore remarked, were Shawnees who probably entered the Mississippi valley after the advent of the Cherokees. There is some evidence, however, in this region, of the presence of another small tribe which must have been driven out or destroyed. The remains which indicate the presence of this tribe are peculiar stone heaps and stone graves. It is possible that the presence of other people in this part of the Ohio valley caused the Cherokees to retreat up the Kanawha instead of southward across Kentucky. The importance archaeologically of the questions here discussed does not end with their bearing upon the history of a single tribe, for at almost every point there are side connections with other peoples. If it be admitted that the Cherokees were mound-builders down to the appearance of the white race on the continent, the mystery of the builders of our ancient monuments is virtually dispelled; for the lines which radiate from this point are so numerous and so far-reaching, that, when traced out to their utmost extent, the whole realm of mound-builders will have been traversed. This is a view of the subject which has not received due consideration on the part of those who admit that some of the works are attributable to Indians, yet claim that others are due to a different and more highly cultivated race. An illustration by partially tracing one or two of these lines will serve to impress the reader with the importance of investigation in this direction. Reference has already been made to the fact that engraved shells similar to those found in the mounds of North Carolina and East Tennessee have been discovered in stone graves of a particular type, and that stone graves of this type often occur in mounds assigned, even by disbelievers of the Indian theory, to the true mound-building age. As the designs on these shells are peculiar, it is reasonable to conclude that the builders of the two classes of works we're contemporaneous, or that there was an overlapping to some extent chronologically. Following up this line, which is traceable by other indications than merely the form of the sepulchres in which the dead were buried, we are led in one direction to the banks of the Delaware, where, history and archaeology inform us, the Indians of that locality were burying their dead in tombs of the peculiar type mentioned, as late as the time of William Penn. It carries us in another direction, to southern Illinois, where links are found connecting unmistakably with the historic tribes of that section. Going back to the Cumberland valley, the chief seat of these stone-grave builders, other lines start out which lead to the ancient works of south-eastern Missouri. Speaking of objects taken from "the peculiar stone graves of the Southern States," especially those of the Cumberland valley, Professor Putnam states that he has classed these "as belonging to the southern mound-builders, from the fact that the careful exploration of thousands of the graves, under the direction of the Museum, shows that their contents, including the human remains, are of the same character as those of the burial mounds in general, in the same region. . . . We have conclusive evidence, in the objects here arranged, that the stone-grave people of the south-west, and at least one group of the mound-builders, were one and the same people." In another place he says, "Many of these carved disks of shell have been found in the graves and mounds of Tennessee and Missouri, and, with the identity of the associated pottery from the two localities, go far to prove the unity of the people, notwithstanding some slight differences in burial customs." tified in concluding that the people of the two sections were tribally identical (if this be his meaning:), yet the strong similarity in the forms, ornamentation, and character of the pottery leaves no doubt that they were contemporaneous, and, in consequence of contact or intercourse, had adopted in some respects similar customs. Thus it is seen, that, commencing with the mounds of the Cherokee district, the connecting- lines lead to the modern and non-mound-building tribes of the Delaware valley, to the historical tribes of Illinois, and to the veritable moundbuilders of middle Tennessee and south-eastern Missouri. Nor do these complete the list of points to which the branches of this single diverging line lead us. As there are other diverging lines, it is apparent, that, when all have been traced out along their various branches, a large portion of the mound area will have been traversed. This renders it highly probable that there was no manifest break in the mound-building age. It may have continued, and probably did, for many centuries, but there is no satisfactory evidence found in the monuments that there were two distinct mound-building ages. On the contrary, the historical, traditional, and archa?ologic testimony is decidedly in favor of the theory that our prehistoric works are attributable to the Indian tribes found inhabiting this country at its discovery, and their ancestors. "The inestimable importance of the subject, the eminence of the author and the novelty of his work all combine to render the little treatise worthy of special consideration. . . . We heartily commend Dr. Hambleton's booklet and wish there were more such works."— Editorial, Boston Daily Advertiser. In this book Mr. Morgan, who is president of the New York Shakespeare Society, sets forth what he believes to be the true function of a Shakespeare Society, which in many respects he makes essentially scientific. The author of this book was for some years president of the New York Microscopical Society, and in this volume he sets forth his views on the spontaneous generation theory and its relation to the general theory of evolution, and on protoplasm and the cell doctrine. Professor Hazen is one of the prominent meteorologists connected with the United States Signal OflSce. In this work he reviews our present information as to tornadoes, severely criticising some of the opinions held in regard to them up to this time. No one has given a more careful study to these destructive storms than has Professor Hazen, and his book will prove a decided contribution to the world's knowledge. Dr. Thomas in this work will reverse the usual method of dealing with prehistoric subjects ; that is to say, he will commence with the earliest recorded history of the tribe as a basis and trace the chain back step by step by the light of the mounds, traditions, and other evidence, as far as possible. He has already presented to the public some reasons for believing the Cherokees were mound-builders, but additional evidence bearing on the subject has been obtained. A more careful study of the Delaware tradition respecting the Tallegwi satisfies him that we have in the Bark Record (Walam Olum) itself proof that they were Cherokees. He thinks the mounds enable us to trace back their line of migration even beyond their residence in Ohio to the western bank of the Mississippi. The object is therefore threefold: 1. An illustration of the reverse method of dealing with prehistoric subjects ; 2. Incidental proof that some of the Indians were mound-builders ; 3. A study of a single tribe in the light of the mound testimony. This work will be an important contribution to the literature of the Columbian discovery which will doubtless appear during the coming two years. "The story is a piquant, good humored, entertaining narrative of a canoe voyage A neater, prettier book is seldom seen.'"— Literary World. "This is a sprightly narrative of personal incident. The book will be a pleasant reminder to many of rough experiences on a frontier which is rapidly recediBg.''— Boston Transcript " The picture of our desolate North-western territory twenty-five years ago, in contrast with its civilized aspect to-day, and the pleasant features of the writer's style, constitute the claims of his little book to present attention.'"— T/ie Dial. A WEEKLY journal devoted to recording the progress of science and the arts. Among recent conti'ibutoi-s may be named : — A. Melville Bell, Joseph Jastrow, J. H. Raymond, M.D., G. Stanley Hall, R. H. Thurston, H. T. Cresson, H. B. Bashore, H. E. Stockbridge, Lieut. Bradley A. Fiske, John T. Stoddard, Charles S. Minot, Jacques W. Redway, Nelson W. Perry, T. Berry Smith, Robert H. Lambom, Gardiner G. Hubbard, Edgar Richards, H. A. Hazen, Cyrus Thomas, T. C. Chamberlin, A. E. Dolbear, W. M. Davis, L. W. Ledyard, John C. Branner, A. T. Drummond, G. Brown Goode, Burt G. Wilder, Godfrey W. Hambleton, M.D. Among the subjects discussed maybe mentioned :— The Suppression of Consumption, Cookery for the Poor, Marine Biological Laboratory, Movements in Young Children, The Phonograph in the Study of Indian Languages, Effigy Mounds, Lightning-Discharge, Sunspots and Tornadoes, Stanley's Explorations, Phonetics, The Lifluence of Baking-Powder Residues on Digestion, Unconscious Bias in Walking, Jade, Clark University, The Influenza, Hallucinations in Alcoholism.	38,230	common-pile/pre_1929_books_filtered	cherokeesinpreco00thom	public_library	public_library_1929_dolma-0002.json.gz:1027	https://archive.org/download/cherokeesinpreco00thom/cherokeesinpreco00thom_djvu.txt
npUy1LImBCtwbMDI	A Racial Study of the Fijians	Produced by Charlene Taylor, Jude Eylander, Joseph Cooper http://www.pgdp.net [Illustration: Simplified map of Fiji showing four regional divisions of population made by the author.] A RACIAL STUDY OF THE FIJIANS BY NORMAN E. GABEL ANTHROPOLOGICAL RECORDS Vol. 20, No. I UNIVERSITY OF CALIFORNIA ANTHROPOLOGICAL RECORDS Editors: C. W. Meighan, Harry Hoijer. Eshref Shevky Volume 20, No. 1. pp. 1-44, plates 1-15 Submitted by editors April 11, 1957 Issued March 27, 1958 Price. $1.00 University of California Press Berkeley and Los Angeles California Cambridge University Press London, England Manufactured in the United States of America CONTENTS _Page_ Introduction 1 The problem and procedure 1 The habitat 2 History 3 Population 3 Racial background 4 Acknowledgments 4 Measurements and indices 5 General 5 Weight 5 Stature 5 Span 5 Span-stature index 5 The trunk 5 Sitting height 5 Relative sitting height 5 Biacromial 6 Relative shoulder breadth 6 Bi-iliac 6 Shoulder-hip 6 Chest breadth 6 Chest depth 6 Thoracic 6 Arms and legs 6 Arm length 6 Humeral length 6 Radial length 7 Radial-humeral 7 Leg length 7 Tibial length 7 Calf circumference 7 The head 7 Head circumference 7 Head length 7 Head breadth 7 Cephalic index 7 Head height 8 Length-height 8 Breadth-height 8 Cranial module 8 Minimum frontal 8 Fronto-parietal 8 The face 8 Bizygomatic 8 Cephalo-facial 9 Zygo-frontal 9 Total face height 9 Total facial index 9 Upper face height 9 Upper facial index 9 Bigonial 9 Fronto-gonial 9 Zygo-gonial 10 Nasal height 10 Nasal breadth 10 Nasal index 10 Nasal depth 10 Nasal-depth index 10 Mouth breadth 10 Lip thickness 10 Ear length 10 Ear breadth 11 Ear index 11 Bicanine breadth 11 Morphological observations 12 Pigmentation 12 Skin color: exposed 12 Skin color: unexposed 12 Hair color 13 Eye color 13 Hair 13 Hair form 13 Hair texture 14 Head hair quantity 14 Hair length 14 Baldness 14 Beard quantity 14 Body hair 15 Grayness: head 15 Grayness: beard 16 The face 16 Prognathism: total 16 Prognathism: mid-facial 16 Prognathism: alveolar 16 Malar projection: lateral 16 Malar projection: frontal 16 Gonial angles 16 Palate shape 16 Chin prominence 17 Chin type 17 The head 17 Temporal fullness 17 Occipital protrusion 17 Lambdoidal flattening 17 Occipital flattening 17 Median sagittal crest 17 Parietal bosses 17 Cranial asymmetry 17 Facial asymmetry 18 Eyes 18 Eye folds: external 18 Eye fold: median 18 Eye folds: internal 18 Eye obliquity 18 Eye opening 18 Forehead 18 Brow ridges 18 Forehead height 19 Forehead slope 19 Nose 19 Nasion depression 19 Root height 19 Root breadth 19 Nasal septum 19 Bridge height 19 Bridge breadth 19 Nasal profile 19 Nasal-tip thickness 20 Nasal-tip inclination 20 Nasal wings 20 Mouth 20 Lip thickness: membranous 20 Lip thickness: integumental 20 Lip eversion 20 Lip seam 20 Teeth 21 Bite 21 Caries 21 Crowding 21 Tooth eruption 21 Wear 21 Ears 21 Ear helix 21 Darwin's point 21 Ear-lobe type 22 Ear-lobe size 22 Ear protrusion 22 Ear slant 22 Body build 22 Body build: endomorph 22 Body build: mesomorph 22 Body build: ectomorph 22 Summary 23 Conclusions 25 Literature cited 26 Plates 27 MAP Simplified map of Fiji showing four regional divisions of population made by the author ... frontispiece A RACIAL STUDY OF THE FIJIANS BY NORMAN E. GABEL INTRODUCTION This paper concerns itself with a physical survey of the native male population of Fiji. The main objective is a description of these people by means of anthropometric procedure.[1] The treatment includes, first, a description of the Fijians as a whole, second, a comparison with neighboring people, and third, regional differences among the Fijians themselves. THE PROBLEM AND PROCEDURE The data used in this survey were secured in 1954 during a stay of seven months in Fiji. My plan was to obtain anthropometric samples from several parts of the archipelago; this plan was only slightly altered as time and transportation facilities directed. Each of the three main administrative districts into which the islands are divided were visited and within each district samples were secured from most of the constituent provinces. The original sample consisted of 880 subjects. Later, 65 subjects were excluded for various reasons: some were part Samoan or Tongan, a few were Rotumans, and others were immature. The number finally used stands at 815. A limited amount of comparative material has been included in order to help locate the Fijians in the overall Pacific picture. These data were drawn from W. W. Howells, "Anthropometry and Blood Types in Fiji and the Solomon Islands" in The American Museum of Natural History, Anthropological Papers, volume 33, part 4, 1933, and from L. R. Sullivan, "A Contribution to Tongan Somatology" based on the field studies of E. W. Gifford and W. C. McKern, in Memoires of the Bernice P. Bishop Museum, volume 8, number 4, 1922. The latter report provides comparison with what may be termed western Polynesians who are also the nearest Polynesians to the Fijians. The Fijian data in Howell's paper make it possible for me to check some of my own Fijian material, and the Solomon Island data in the same report provide a Melanesian measuring stick. Since an over-all description of the Fijians is the initial concern of this paper, each physical trait measured or derived from measurement is tabulated according to range, average, and deviation. Traits observed but not measured are presented according to degree of development, e.g., absent, medium, and pronounced, and according to percentage of occurrence. Further statistical manipulation is not deemed necessary for the writer's purposes. It is well established that the Fijians are a mixed people. They are regarded, and with good reason, as a hybrid of, mainly, Melanesian and Polynesian components. Their geographical location, their history, and their physical appearance bear this out. The proportions of Polynesian and Melanesian elements are, of course, not evenly distributed throughout Fiji. Even superficial observation indicates that the natives range from strongly Melanesian to markedly Polynesian. To demonstrate how this variability follows certain regional trends, the data have been broken down into four geographical areas. This subdivision rests on several considerations and merits further comment. One of the subgroups represents the people of the mountainous interior of Viti Levu, the main island of Fiji (see accompanying map). This region may be regarded as something of a refuge area. Fijians from this relatively isolated locality might reasonably be expected to exhibit more of the earlier racial elements of the total composition. It should be pointed out, however, that the degree of isolation associated with this; interior; group is not extreme. Fiji tradition and history indicate extensive interregional movement. Particularly in early historic times, when the advent of firearms and other Western culture greatly stimulated intergroup warfare and cannibalism, there was much moving about from one region to another. With all this, the interior people still remained, as indeed they are today, more apart from the rest of the population and less subject to outside influence. The second segment chosen for interregional comparison is in the central Lau Islands and is designated in this paper as the "eastern" group. Lying as they do, at the eastern end of Fiji, they are closest to Tonga, the nearest Polynesian neighbors. Tongan contact with Fiji in prehistoric as well as more recent times is well established.[2] It is in the Lau Islands that Polynesian cultural affinities are most marked. Hence, it seems a logical choice for a second and separate glance in the racial history. The third comparative sample might be termed an intermediate group. It is taken from the coastal villages of eastern Viti Levu, largely from the provinces of Rewa and Tailevu. This area is geographically between the "interior" and "eastern" groups and is referred to in this paper as the "coastal" group. The final regional division represents the northwestern parts of Viti Levu. This is the place where, according to Fiji tradition, their ancestors first landed after migrating from the west.[3] Fijian legend, which gives this hint of their ancestry, does not include a physical description of these immigrants. Nor does it define the physical appearance of the earlier people whom the newcomers encountered and with whom they mingled. On the rather slim hope that anthropometry might shed a little light on this questionable phase of Fijian history, this area, along with the first three, has received separate treatment. THE HABITAT The islands of Fiji are centrally located in the southwest Pacific. Over three hundred islands and islets make up the archipelago, which spreads between latitudes 15' and 22' south of the equator for 300 miles. The international date line runs through Fiji at the Koro Sea and the Moala Island group. The total land area of the islands is about the equivalent of the state of Delaware, somewhat over 7,000 square miles. Two great islands account for nearly 95 per cent of the total area: Viti Levu, the largest, is over 4,000 square miles, and Vanua Levu, about half as large. Over 90 per cent of the native population lives on these two islands although nearly a hundred other islands are inhabited. Most of the islands are made up of volcanic and sedimentary rocks. The largest islands rest on a submerged portion of an ancient land mass, sometimes called the Melanesian continent, which goes back in time to the Paleozoic and, in its prime, intermittently connected Fiji with southeastern Asia and Australia. Subsequent submergence, followed by cycles of volcanic upbuilding, erosion, and more submergence over eons of time, gave the big islands their upper foundations. The last extensive volcanic activity and land uplift occurred in the Pleistocene and accounts for many of the present mountain masses. The final touches to the Fiji profile have been wrought by more recent weathering and erosion. Sedimentation is still going on at river mouths and along the coasts, where deltas are being built and mangrove thickets flourish. Many of the smaller islands are old limestone masses that were pushed up from the sea. Unlike the high craggy volcanic islands, these are lower and flat-topped. Typically, they contain a basin-shaped depressed area that is surrounded by a rim. These depressions are usually fertile and heavily forested. Coral islands make up the third variety of land forms. These are always small and low. Their small size, thinner soil, and lack of fresh water make them much less suitable for human habitation. But even a thin layer of soil produces a luxurious vegetation. Fringing and barrier reefs are abundant throughout the archipelago, surrounding nearly every island. The most striking of these formations is the Great Sea Reef, which forms an arc of nearly 300 miles along the western fringe of Fiji and encloses large areas of coral-infested sea. Moderately high mountains give to the larger islands a generally rugged terrain. The more extensive ranges lie across the path of the prevailing south and easterly winds producing windward and leeward climatic areas. On the windward side rainfall is heavy and rather evenly distributed over the year. Here the valleys and mountain slopes support a typical dense tropical growth. The leeward side, however, receives much less moisture and has wet and dry seasons. Scattered patches of trees and grasses cover the ground, whereas heavy stands of forest are confined to valley bottoms and higher mountain slopes. The mountainous interior of Viti Levu contains a number of peaks over 3,000 feet, the highest of which is Mt. Victoria, 4,341 feet. Surface water is abundant on the bigger islands. Several large and navigable rivers drain Viti Levu and Vanua Levu. The Rewa River, on the east side of Viti Levu is the largest and is navigable for small craft for 70 miles. Smaller rivers and hundreds of streams are important sources of food and drink for the people of the interior. Great flood plains are formed at the mouths of the larger rivers. These and the fertile flats that run back along the valleys contain the greatest population densities. The climate is generally pleasant and healthful. Tropical extremes of heat and humidity are moderated by the prevailing trades, which usually supply cool and pleasant breezes from the east. Still, days of uncomfortable heat and oppressive humidity are not unknown; however, such periods are protracted only in the interior. The climate is far from uniform throughout the islands. The windward sides, where rainfall often exceeds a hundred inches, have a more even temperature and sunshine is more moderate. On the leeward sides there is less general cloudiness and more sunshine, especially during the dry season. The smaller islands generally resemble the leeward areas in climate. Native plant and animal life, like much of the southwest Pacific, is southeastern Asiatic in type and in origin. In the more profuse and varied windward sides there are several general vegetation zones. Along the coasts and in the larger river basins occur alluvial vegetation largely dominated by several kinds of mangrove, which is densest in mud flats washed by the tide. In this zone trees are scattered, and many of them bear useful nuts and fruits. On the slopes and ridges behind the coastal belts are the great tropical rain forests. They make up a dense cover of evergreen trees interwoven with wild creepers and vines. Thick stands of shrubs and smaller trees add to the tropical profusion. Above 2,000 feet the forests thin out and become more heavily coated with moss and lichens, and ferns and orchids attach themselves to the branches. Beyond 3,000 feet is the cloud belt, and above this trees become stunted and are finally replaced by hardy shrubs that cling to the rocks and crags. On the leeward sides, patches of rain forest are found only in the moister areas. More typical of this zone are thin-leaved trees interspersed in large expanses of meadow and grassland. A number of native plants are very vital to the Fijian livelihood and some have modern economic importance. Several timber trees are essential to house building, canoe construction, and wood carving. The ubiquitous palms, here as elsewhere in the Pacific, are vital sources of food, drink, building, and weaving materials and cordage. The mangrove provides firewood, house poles, fishing fences, and traps, laths for bows and black dye for their hair and tapa. Valuable starch is secured from the sago palm, which is cut just before flowering, and the leaves are a common thatching material. Various reeds, canes, and bamboos and lianas are useful to Fiji economy. In the drier areas reeds and grasses provide material for house walls, thatch, fish fences, and arrow shafts. Several kinds of trees yield edible nuts and fruits. Like other central-Pacific island groups, Fiji is poorly provided with indigenous mammals. A small gray rat is a considerable pest in gardens and homes, and a large nocturnal bat, which is called a flying fox, lives in tree colonies and is often seen at dusk in banana groves or other feeding places. All the economically important animals of Fiji have been introduced, such as pigs, fowl, dogs, cattle, horses, sheep, and goats. Bird life is diverse and interesting, although in a number of places introduced forms, like mynahs and turtle doves, have forced the native varieties back into the jungle. Several game birds such as doves, pigeons, and ducks are occasionally hunted. Snakes and lizards are fairly common on the islands; none is poisonous. Some are eaten, but the practice is not usual. Snakes had a more important place in the former religious and totemic practices. Much more vital to the native economy is the abundant and varied marine life. This, with gardening, provides the foundation of Fijian subsistence. Turtles, crabs, prawns, eels, to say nothing of scores of fishes, are hunted, trapped, poisoned, speared, and netted. The cycle of the balolo worm has here the same importance as in other Pacific islands. HISTORY The first western contact with Fiji was made in 1643 when Captain Abel Tasman entered Fijian waters and sighted several islands and reefs without realizing the nature of his discovery. Over a hundred years later, Captain Cook made a second contact by stopping at one of the southern Lau Islands. Real knowledge of the area began in 1792 when Captain Bligh sailed through the archipelago from the southeast to the northwest, following the famous mutiny of the _Bounty_. Bligh made an attempt to land, was attacked by natives, and continued through the islands with no more landings. He did, however, make a record of most of the islands he passed. In the nineteenth century, commercial contacts began in the form of sandalwood trade. This profitable commodity brought Europeans and Americans first to the Sandalwood Coast on the west side of Vanua Levu. During this period the first systematic survey of Fijian waters was made by the U.S. Exploring Expedition in 1840. After little more than a decade the sandalwood supply was depleted to the point where trade virtually ceased. As a result of this initial commercial contact, which was mainly around western Vanua Levu and eastern Viti Levu, some marked changes were effected in Fijian culture. After the sandalwood traders abandoned Fiji for more profitable fields, a number of deserters and ship-wrecked men remained. These beachcombers, along with firearms that had been introduced by trade or salvaged from wrecks, brought about the first striking alterations. Rival chiefs competed for the acquisition of muskets, gunpowder, and beachcombers. The latter in some instances became attached to royal households as dubious advisors and instructors in the use of guns, powder, and shot. Some of these coaches enjoyed a status resembling that of household pets. The introduction of firearms changed the native political scene and increased the scope and destructiveness of warfare. For a time the rulers of Mbau in eastern Viti nearly monopolized the supply of muskets and white men. This established their political supremacy over rival leaders. Larger and stronger political and military alliances, some resembling small kingdoms, developed for purposes of defense or aggression. As warfare grew more frequent, new diseases entered the islands and trade in liquor advanced. After the third decade of the nineteenth century better elements began to enter Fiji and ensuing culture contact was not so consistently deplorable. _Bêche-de-mer_ traders and whalers began to visit the islands for trade goods and supplies. Some began to settle at the east end of Viti Levu. Missionaries came in the 1830's and the Christianization of Fiji began. Internal conflict between rival chiefs, attacks on French, British, and American ships, with subsequent reprisals, continued and intensified. By mid-century, rivalry between the local kingdoms of Mbau and Rewa reached a peak. At this time the powerful ruler of Mbau, Thakombau, who dominated a large segment of eastern Viti Levu, had become hard pressed by his Rewa enemies. Thakombau submitted to the missionaries who had been pressing his conversion. With his support of the missionaries, the native struggles became a religious war between Christianity and paganism as well as between nativism and westernism. Thakombau's cause was rescued in 1855 when King George of Tonga brought an army of 2,000 warriors to Fiji and combined his strength with that of the kingdom of Mbau. Thenceforth Thakombau remained the paramount chief in eastern Fiji and for some twenty ensuing years ruled under the dominance of Tongan princes. Another Tongan chief, Ma'afu, arrived in 1848 and set up a political domain that rivaled the kingdom of Thakombau. Throughout these struggles and particularly with the conversion of Thakombau and the leadership of the already Christianized Tongan chiefs, native religion, including cannibalism, rapidly declined. Meanwhile, English, Australian, and New Zealand settlers were augmenting earlier trade contacts. Plantations and trade centers developed, and in 1857 a British consul was appointed and set up at Levuka on the east coast of Viti Levu. A few years later Thakombau sought relief from the payment of indemnities to foreign powers and from internal harassments by an offer to cede his dominions to Great Britain. The initial offer was declined and the British consul was recalled in 1860. The next ten years saw a continuation of political and military turmoil stemming from rival interests of native rulers, Tongan interlopers, and European immigrants. A second appeal to the British government resulted in an unconditional deed of cession on October 10, 1874, which marks the beginning of Fiji's status as a British Crown Colony. POPULATION Over 300,000 people live in the Fiji Islands. Of these about 140,000 are native Fijians. The others are arranged in the following divisions:[4] Indians 154,803 Europeans 6,500 Part European 7,496 Polynesians } Melanesians } 4,133 Micronesians } Rotumans 3,990 Chinese 3,857 Others 649 When Fiji became a British Crown Colony in 1874 the population was entirely native except for a handful of outsiders. At that time the population has been variously estimated at approximately 200,000. Shortly thereafter a measles epidemic reduced their number severely. This, with other epidemics and maladies for which they had little or no immunity or resistence, continued the decimation until by 1905 there were only 87,000. During the next decade they held their own, until in 1919 the influenza scourge brought them to their lowest level of 83,000. This was the last serious setback to their number; since that time the population has been on the upgrade. A present threat to Fijian population, in the opinion of many, stems not from disease but from the Indian presence. This began in the latter part of the nineteenth century when Indian immigration of indentured laborers began. The influx went on until 1916 by which time some 40,000 to 50,000 Indians had come to Fiji and very few had returned to India. Since then, the Indians have increased more rapidly than the Fijians until they now outnumber them. This situation has, of course, created numerous problems beyond the scope of this paper. It is significant to point out that intermarriage or interbreeding between Fijians and Indians is relatively slight. The amount of mingling of Fijians with Europeans or Orientals cannot be demonstrated statistically, but it has not been extensive. The Fijians, on the whole, retain pretty much of their prehistoric racial make-up. RACIAL BACKGROUND It is well established that the Fijians are a mixed people, derived mainly from Melanesian and Polynesian sources. Both of these parental strains in turn are commonly believed to be racial blends. Hooton describes the Melanesians as Oceanic Negroes whose composition includes Negrito, Australoid, "plus convex-nosed Mediterranean plus minor fractions of Malay and Polynesian."[5] Birdsell sees the same three strains in Melanesia which he believes contribute to the Australians, namely Negrito, Murrayan, and Carpentarian, plus a small amount of Mongoloid. He believes they differ from Australians in being "basically negritic in their genetic composition as a result of the rain forest environment."[6] Polynesians, however, are usually thought to be derived from Caucasoid, Mongoloid, and Negroid strains in which the Caucasoid component is more often the strongest. The composite character of the Fijians has been variously explained as far as order and time of the contributing elements are concerned. One theory regards a Negroid stock as aboriginal to which a Polynesian strain was later added. An early explanation of this sort is that of Fornander who held that the ancestors of the modern Polynesians coming from southeastern Asia via Indonesia in the early centuries A.D. made a prolonged stopover in Fiji as they moved eastward. This left a Polynesian imprint on the native Fijian physical appearance as well as on their language and culture.[7] Later on, Churchill added a second movement of Polynesians from the west about a thousand years later. This was used to explain a certain amount of Mongoloid elements that needed accounting for in western Polynesia.[8] A differing interpretation brings the Polynesian influence into Fiji from the east in relatively recent times. Thomson, for example, regards it as mainly Tongan. There are many references in the eighteenth and nineteenth centuries to Tongan presence in Fiji; they came to trade, to fight, and merely to visit. Hocart believes the Polynesians at one time occupied most of Fiji until they were driven eastward to Tonga and Samoa by native Melanesians.[9] Howells tentatively suggests another possibility: originally all of Fiji was occupied by Polynesians except perhaps for some Melanesian tribes in the mountainous interior of Viti Levu. Around the eleventh century a wave of immigrants from the west reached Fiji. "The newcomers, taking possession of the archipelago, partly amalgamated with and partly pushed out the Polynesian tenants, just as did the hill tribes of Hocart's theory, the refugees fleeing to Somoa and Tonga."[10] Howells associates this immigration with the Fijian tradition of an arrival of ancestral families from across the western sea. This Fijian tradition of their own origin includes a landing on the west coast of Viti Levu at Nandi by an ancestral chief and his sons who came across the sea from the west. Several of his sons moved eastward and eventually founded families with native wives in various parts of the archipelago. These families ultimately became consolidated into present-day tribes or federations. Most Fijian social units derive their origin from this or similar legendary immigrations. These eposodes occurred eight or ten and, in one case, fifteen generations ago.[11] Where these ancestors came from or what their racial affiliations were is not described in the stories. On the basis of supposed similarities of place-names, claims have been made for Africa as the place of origin, but the validity of them is dubious. It is likely that these traditions refer only to the more recent immigrations from the west. As to the racial make-up of the ancestors, it is commonly believed that they were Polynesians who, after settling in various parts of Fiji, took native wives, presumably Melanesian, and originated many of the existing family lines. This assumption does not rest on any actual physical reference to their appearance but on such cultural data as their patrilineal succession and their tradition of strong hereditary chieftainship. ACKNOWLEDGMENTS I am indebted to a number of people of Fiji whose assistance and coöperation were helpful. Thanks are due to Sir Ronald Garvey, governor of Fiji, whose approval of my project gave administrative sanction. Mr. G. Kingsley Roth, the Secretary for Fijian Affairs, secured for me the coöperation of the Fijian Affairs Department, which in turn gave me access to the proper native officers and leaders, furnished me with necessary transportation; he also gave me some sound advice. Also of the Fijian Affairs Office, Ratu Dr. Dobi helped me make the necessary contacts as my work took me from one area to another. Mr. Robbin H. Yarrow, safety officer of the Emperor Gold Mining Company, was most helpful during my stay at Vatukoula, where I secured an excellent sample of the northern provinces. The young Fijian who acted as my interpreter, guide, and recorder was Joji Qalelawe; my especial thanks to him for his intelligent and cheerful coöperation. MEASUREMENTS AND INDICES GENERAL _Weight_[12] No. Range Mean S.D. C.V. Total sample 814 105-300 163.0 20.3 12.5 Interior 0 0 0 0 0 East 73 130-245 168.1 19.3 11.5 Coast 210 118-300 160.7 22.8 14.2 N.W. 79 120-212 161.9 16.9 10.4 The average weight of 163 pounds, coupled with their rather tall stature, describes the Fijian as a large person, on the whole. Their generous weight does not reflect excessive obesity; the body build, as will be pointed out later, is prevailingly muscular and athletic. Variation among the regional samples is not significant; all the groups average more than 160 pounds. _Stature_ No. Range Mean S.D. C.V. Total sample 815 150.1-195.0 172.5 6.1 3.5 Interior 154 150.1-183.7 169.6 6.0 3.5 East 120 160.2-190.5 173.3 6.0 3.5 Coast 210 156.1-195.0 173.4 5.8 3.4 N.W. 79 159.8-186.0 172.7 5.8 3.3 Fiji (Howells) 133 158-190 170.8 6.1 3.6 Solomons (Howells) 85 146-181 160.2 6.8 4.2 Tonga (Sullivan) 92 160-188 173.0 5.2 3.0 The stature of the Fijians is moderately tall. Howells' series of Fijians, as well as mine, indicate this category. In this measurement, the Fijians are similar to the Tongans. They are 12 cm. taller than the Melanesians. Among the Fijian themselves, the interior people of the highlands are definitely shorter than the rest of the population. Rumors still persist of remnants of pygmoid people in the interior mountains of Viti Levu. I found no evidence of them either in my travels in the interior or by extensive inquiries among natives and Europeans who had thorough knowledge of the whole island. _Span_ No. Range Mean S.D. C.V. Total sample 815 155.0-208.0 180.0 15.1 8.8 Interior 154 155.0-201.0 179.5 7.5 4.2 East 120 166.4-200.5 178.1 24.3 13.6 Coast 210 160.1-208.0 181.2 14.6 8.1 N.W. 79 165.1-202.0 180.0 21.6 11.9 Span of the arms also reflects the generous proportions of the Fijians. Regional difference is not marked. Relative to stature, the hill people have the longer arms and the eastern natives the shortest. The greater relative arm length of the hill tribes seems to be owing more to deficiency of stature than to excessive arm length or shoulder breadth. _Span-Stature Index_ No. Range Mean S.D. C.V. Total sample 815 96.1-116.3 104.3 8.5 8.15 Interior 154 99.4-115.1 105.2 2.3 2.2 East 120 99.1-108.5 102.7 13.5 13.14 Coast 210 97.9-116.3 104.4 7.7 7.4 N.W. 79 100.2-109.7 104.1 12.0 11.5 THE TRUNK _Sitting Height_ No. Range Mean S.D. C.V. Total sample 815 75.1-100 87.0 3.5 3.9 Interior 154 75.1-94 84.4 9.4 11.0 East 120 81-100 88.5 3.5 3.9 Coast 210 80-99 87.7 3.2 3.6 N.W. 79 80-94 86.0 2.9 3.3 Fiji (Howells) 132 78-101 88.3 3.06 3.46 Solomons (Howells) 85 69-95 83.6 3.8 4.5 A total sitting height average of 87 cm. attests the generous general body length. A regional trend follows the same curve as that for stature. The eastern body length is greatest; it exceeds the over-all average by 1-1/2 cm. and is more than 4 cm. larger than the interior people who fall at the bottom of the scale of sitting height. Howells' Fijian series is close to my eastern average. Compared with the Solomon Islands natives, the Fijians are much more elongated. _Relative Sitting Height_ No. Range Mean S.D. C.V. Total sample 815 45-58 50.4 1.5 3.0 Interior 154 46-56 49.8 1.4 2.8 East 120 48-54 51.0 1.3 2.5 Coast 210 46-56 50.5 1.4 2.8 N.W. 79 47-54 50.2 1.4 2.8 Fiji (Howells) 132 46-57 51.7 1.36 2.63 Solomons (Howells) 85 46-57 52.1 1.64 2.92 The relative sitting height ratio for all Fijians is 50.4 per cent. The eastern average of 51 per cent indicates a little more legginess, whereas the interior groups tend somewhat to longer trunks. _Biacromial_ No. Range Mean S.D. C.V. Total sample 815 28-47 39.7 8.2 6.2 Interior 154 29-43 39.0 6.2 4.7 East 120 35-45 39.9 6.1 4.0 Coast 210 28-45 39.7 7.6 4.9 N.W. 79 35-47 40.5 6.6 3.9 The Fijians are generally a broad-shouldered people. The inhabitants of Ra and Ba have the highest average and the interior people are least broad-shouldered. _Relative Shoulder Breadth_ No. Range Mean S.D. C.V. Total sample 815 18-27 22.3 1.3 5.8 Interior 154 19-25 22.9 1.0 3.9 East 120 20-26 23.0 1.0 3.9 Coast 210 18-26 22.9 1.0 4.4 N.W. 79 20-27 23.4 3.1 13.2 Relative to total stature, shoulder breadth averages 22.3 per cent. No significant regional differences are indicated. _Bi-Iliac_ No. Range Mean S.D. C.V. Total sample 815 23-40 29.2 5.6 5.3 Interior 154 25-38 29.0 5.1 5.2 East 120 27-34 29.5 4.1 4.8 Coast 210 23-37 29.2 5.9 5.5 N.W. 79 26-32 29.3 4.6 5.0 The Fijians, as a whole, are fairly broad-hipped; this condition holds with little variation in all the provinces. _Shoulder-Hip_ No. Range Mean S.D. C.V. Total sample 815 58-101 73.7 4.3 5.8 Interior 154 65-100 74.6 4.2 5.6 East 120 67-82 73.8 3.2 4.3 Coast 210 58-99 73.5 4.3 5.9 N.W. 79 62-86 72.8 5.9 8.1 The total shoulder-hip ratio describes the shoulders as 73.7 per cent as wide as the hips. These ratios do not vary greatly in different parts of Fiji. The somewhat higher index of the hill groups is owing largely to their narrower shoulders, whereas the superior shoulder breadth of the northwest provinces contributes mostly to the lower hip-shoulder index. _Chest Breadth_ No. Range Mean S.D. C.V. Total sample 815 24-39 28.6 6.4 5.7 Interior 154 25-33 28.6 3.3 4.7 East 120 26-39 29.4 7.2 5.8 Coast 210 25-37 28.7 7.8 6.2 N.W. 79 25-32 28.9 4.3 4.9 Broad chests are also characteristic in Fiji. The eastern men surpass the Viti Levu males, and the interior groups have the narrowest chests, but the regional variations are small. _Chest Depth_ No. Range Mean S.D. C.V. Total sample 815 184-308 22.9 5.5 7.0 Interior 154 195-263 22.4 3.2 5.8 East 120 189-295 22.5 4.9 6.6 Coast 210 184-300 21.7 5.7 7.2 N.W. 79 192-250 21.8 3.3 6.0 The chests of the Fijians are also fairly deep. The close similarity in chest depth of the interior group and the eastern sample is rather striking inasmuch as the former are nearly 4 cm. shorter in stature. This would indicate that the interior group, for their size, are relatively deep-chested. _Thoracic_ No. Range Mean S.D. C.V. Total sample 815 59-96 76.4 4.6 6.0 Interior 154 69-88 78.5 3.9 5.0 East 120 65-85 76.3 4.3 5.6 Coast 210 56-89 75.5 4.7 6.2 N.W. 79 65-85 75.7 4.4 5.8 The thoracic index shows that the Fijians are deep-chested relative to thoracic breadth as well as in absolute values. Again the interior people stand out for their deeper chests. ARMS AND LEGS _Arm Length_ No. Range Mean S.D. C.V. Total sample 815 45-87 75.2 5.0 6.6 Interior 154 45-83 73.6 4.8 6.1 East 120 52-84 75.1 3.9 5.2 Coast 210 57-87 76.0 4.9 6.4 N.W. 79 55-86 75.3 6.6 8.8 The over-all arm length is 75.2 cm. Shorter arms seem to be characteristic of the interior population where the average is nearly 2 cm. less than the over-all average. The eastern group has the longest arms; the other samples are intermediate. _Humeral Length_ No. Range Mean S.D. C.V. Total sample 815 26-39 32.8 8.6 5.7 Interior 154 28-38 32.8 7.1 5.2 East 120 28-39 32.9 8.3 5.6 Coast 210 26-38 32.9 9.1 5.8 N.W. 79 28-38 33.0 7.9 5.4 Length of the upper arm averages 33 cm. for all Fijians; the several provinces are closely similar in this trait. _Radial Length_ No. Range Mean S.D. C.V. Total sample 815 23-35 27.6 4.1 5.1 Interior 154 24-33 27.3 2.4 4.5 East 120 23-34 27.5 6.9 6.1 Coast 210 24-35 27.9 3.5 4.8 N.W. 79 25-32 27.9 3.4 4.8 Lower arm length is 27.6 cm. and also varies but little among the regional samples. _Radial-Humeral_ No. Range Mean S.D. C.V. Total sample 815 65-113 84.0 4.2 5.0 Interior 154 77-104 83.0 3.8 4.6 East 120 65-95 83.5 4.7 5.6 Coast 210 75-113 84.7 4.2 4.9 N.W. 79 77-94 82.2 3.6 4.3 The radial-humeral ratio indicates that the lower arm of Fijians is 84 per cent as long as the upper arm. None of the subgroups deviates markedly from this average. _Leg Length_[13] No. Range Mean S.D. C.V. Total sample 815 61-98 84.3 10.5 12.5 Interior 154 74-96 81.1 8.6 12.9 East 120 73-96 84.1 8.6 10.3 Coast 210 68-97 85.3 7.2 8.5 N.W. 79 75-95 85.7 4.4 5.2 Average leg length is 84.3 cm., and some regional differences are manifest. The legs of the hill people are shorter by 3 cm. than are the other groups. Their neighbors to the northwest and east have the longest legs, and the eastern are intermediate. _Tibial Length_ No. Range Mean S.D. C.V. Total sample 815 34-49 40.9 8.3 6.9 Interior 154 35-45 40.3 13.4 10.8 East 120 35-47 40.7 6.2 5.2 Coast 210 35-47 41.2 6.8 5.1 N.W. 79 36-47 40.9 6.1 5.9 Lower leg length is around 40 cm. for all Fijians. The regional pattern is similar to that of total leg length: shortest in the highlands, intermediate in the east, and longest in the coastal and northwestern districts. _Calf Circumference_ No. Range Mean S.D. C.V. Total sample 815 29-57 37.6 6.7 7.1 Interior 154 31-51 37.0 6.4 7.1 East 120 33-50 38.1 4.7 6.5 Coast 210 29-48 37.2 9.4 7.9 N.W. 79 30-43 37.7 7.6 6.3 The generous girth of the calf of the Fijians reflects their sturdily muscled legs. The eastern groups excel the other Fijians in this respect, whereas the interior groups have the lowest average for calf circumference. THE HEAD _Head Circumference_ No. Range Mean S.D. C.V. Total sample 815 410-630 562.4 7.8 6.7 Interior 154 537-613 565.3 4.1 2.5 East 120 528-630 566.3 4.9 2.9 Coast 210 410-630 563.5 4.6 3.5 N.W. 79 537-597 557.7 14.3 11.5 The head circumference average of 562.4 mm. Probably is a little on the large size because of the thick wiry hair of most Fijians; the eastern groups appear to have the largest heads and the northwestern groups show a rather abrupt drop. _Head Length_[14] No. Range Mean S.D. C.V. Total sample 815 162-215 187.9 9.4 5.0 Interior 154 170-210 190.1 7.6 4.0 East 120 172-209 188.6 6.6 3.5 Coast 210 162-215 187.4 13.5 7.2 N.W. 79 165-214 187.2 7.9 4.2 Fiji (Howells) 133 164-208 188.8 7.29 3.86 Solomons (Howells) 85 170-208 188.5 6.5 3.5 Tonga (Sullivan) 117 173-213 191.0 6.6 3.5 Total head length for all Fijians is 187.9 mm; longest heads occur in the interior. Both Howells' Fijian average and the Solomon Islands series are close to the above value. Gifford's Tongan head length of 191 mm. Somewhat exceeds the Fijian. _Head Breadth_ No. Range Mean S.D. C.V. Total sample 815 122-186 155.9 6.8 7.7 Interior 154 135-170 152.1 6.6 4.3 East 120 144-172 157.2 5.2 3.3 Coast 210 141-186 158.3 9.3 8.5 N.W. 79 122-185 152.9 8.6 8.2 Fiji (Howells) 133 135-170 153.7 6.1 3.9 Solomons (Howells) 85 126-158 144.7 5.2 3.6 Tonga (Sullivan) 117 145-167 154.8 4.3 2.8 General head breadth is 155.9 mm., and considerable regional variation is shown. Fijians of the interior have the narrowest heads, whereas the coastal and eastern people have appreciably wider heads. Howells' series of Fijians are closest to my highland groups. The Solomon Islanders are markedly narrower headed than the Fijians, whereas Sullivan's Tongan series is nearer the Fijian average. _Cephalic Index_ No. Range Mean S.D. C.V. Total sample 815 68-99 83.0 6.4 7.7 Interior 154 68-96 80.0 6.0 7.3 East 120 72-92 83.9 3.8 4.5 Coast 210 72-99 84.2 7.2 8.6 N.W. 79 71-95 81.6 10.3 12.6 Fiji (Howells) 133 68-94 81.54 4.7 5.7 Solomons (Howells) 85 65-88 76.8 3.9 5.1 Tonga (Sullivan) 117 73-89 81.1 3.1 3.9 Most Fijians tend to brachycephaly. The eastern natives and those of the coastal series have the broadest heads. The interior people show definitely lesser values in this ratio than do the other groups. Howells' Fijian series is close to the northwestern Fijians in their mesocephaly, and so is the Tongan mean. The Solomon series borders on dolicocephaly. _Head Height_ No. Range Mean S.D. C.V. Total sample 815 110-154 129.5 6.8 7.9 Interior 154 114-140 127.7 4.8 3.8 East 120 114-148 129.6 5.0 3.9 Coast 210 112-154 120.0 7.0 5.4 N.W. 79 117-142 127.6 9.2 8.9 Head height averages do not differ greatly among the provinces. The interior and northwestern people have somewhat lower heads; the coastal and eastern people show slight superiority. _Length-Height_ No. Range Mean S.D. C.V. Total sample 815 55-84 69.0 3.4 3.6 Interior 154 59-77 67.2 3.9 5.8 East 120 61-78 68.7 3.2 4.7 Coast 210 55-84 69.4 3.7 4.3 N.W. 79 58-84 68.1 4.5 3.5 Relative to head length, the cranial vault of Fijians is high. The mountain people show the lowest relative head height, whereas the other provinces are nearer to the over-all average. _Breadth-Height_ No. Range Mean S.D. C.V. Total sample 815 66-102 83.0 3.0 3.3 Interior 154 75-96 84.0 3.9 4.6 East 120 75-91 82.4 3.4 4.1 Coast 210 66-97 82.8 5.3 8.4 N.W. 79 73-92 81.2 8.6 9.7 Head height relative to total breadth is 83 per cent. In this ratio the interior groups have the highest index, a condition owing more to deficiency in cranial breadth than to superior head height. _Cranial Module_ No. Range Mean S.D. C.V. Total sample 815 141-176 157.7 10.5 6.7 Interior 154 147-166 156.6 11.5 7.3 East 120 148-172 158.4 4.4 2.7 Coast 210 143-176 158.5 15.5 9.7 N.W. 79 141-171 155.9 10.7 6.7 Head size as expressed by the cranial module averages 157.7 mm. for all Fijians. Regional fluctuation is unimportant. _Minimum Frontal_ No. Range Mean S.D. C.V. Total sample 815 99-125 109.9 4.0 2.7 Interior 154 100-121 109.8 3.6 3.3 East 120 99-122 110.8 3.8 3.4 Coast 210 100-125 109.7 4.7 4.3 N.W. 79 101-120 109.4 3.7 3.4 A minimum frontal diameter of 109.9 mm. indicates a fairly ample forehead breadth for the total sample. None of the subgroups depart much from this value. _Fronto-Parietal_ No. Range Mean S.D. C.V. Total sample 815 58-89 70.6 4.3 6.1 Interior 154 63-82 72.2 3.3 4.6 East 120 64-79 70.5 3.0 4.3 Coast 210 58-77 69.9 4.1 5.9 N.W. 79 61-89 69.7 8.7 12.5 Forehead breadth relative to total cranial width is 70.6 per cent. The greatest deviation from this average occurs in the interior where the fronto-parietal ratio is 72.2 per cent and lesser head breadth more than greater forehead width causes the higher index. THE FACE _Bizygomatic_ No. Range Mean S.D. C.V. Total sample 815 110-164 145.7 5.0 3.4 Interior 154 110-163 145.8 6.3 4.3 East 120 137-161 146.7 4.3 2.9 Coast 210 128-164 145.2 4.9 3.4 N.W. 79 136-156 145.1 4.3 3.0 Fiji (Howells) 132 130-159 144.05 5.05 3.5 Solomons (Howells) 84 115-149 138.0 5.5 4.0 Tonga (Sullivan) 116 131-159 143.5 5.9 4.1 Broad faces are the rule among most of these people, as the total average of 145.7 mm. shows. Regional values for this criterion are closely alike in all parts of Fiji, the eastern showing a slight superiority in bizygomatic breadth. Howells' Fiji series is slightly lower in this diameter as is the Tongan average. The Solomon Islands natives have definitely narrower faces. _Cephalo-Facial_ No. Range Mean S.D. C.V. Total sample 815 82-108 93.5 5.7 6.1 Interior 154 84-108 96.0 4.8 5.0 East 120 82-102 93.3 3.2 3.4 Coast 210 85-103 92.5 5.7 6.2 N.W. 79 80-104 92.6 6.4 7.3 Fiji (Howells) 132 85-111 93.7 3.5 3.7 Solomons (Howells) 84 85-111 95.4 3.8 4.0 Tonga (Sullivan) 116 85-103 92.8 3.5 3.7 Face breadth relative to head width averages 93.5 per cent for all Fijians; Howell's series is much the same. The narrower heads of the interior people largely account for their higher index; otherwise there is general similarity in the several provinces. _Zygo-Frontal_ No. Range Mean S.D. C.V. Total sample 815 64-100 75.5 3.0 3.9 Interior 154 64-98 75.4 3.2 4.2 East 120 68-99 75.5 2.5 3.3 Coast 210 66-100 75.5 3.1 4.1 N.W. 79 66-93 75.4 2.9 3.8 Tonga (Sullivan) 116 63-84 73.1 4.2 5.8 The ratio of forehead width to face breadth is 75.5. All of the regional averages for the zygo-frontal index are strikingly alike among the Fijians in every instance; the forehead is about three-quarters the breadth of the face. The Tongan ratio is a little lower. _Total Face Height_ No. Range Mean S.D. C.V. Total sample 815 100-147 122.5 6.0 4.9 Interior 154 103-137 121.3 5.6 4.6 East 120 110-147 124.7 5.8 4.7 Coast 210 107-142 122.6 6.1 5.0 N.W. 79 100-143 121.7 6.8 5.6 Fiji (Howells) 133 105-159 121.8 6.9 5.7 Solomons (Howells) 85 100-129 116.4 6.6 5.7 Tonga (Sullivan) 116 112-147 128.2 6.8 5.3 Fijian faces have the moderate average height of 122.5 mm. Slightly shorter faces occur in the interior people, whereas the greatest total face height average occurs in the east. The Fijian of Howells' series is close to mine. The Tongan value for face height describes them as definitely longer faced. The Solomon Islanders depart in the other direction with decidedly shorter faces. _Total Facial Index_ No. Range Mean S.D. C.V. Total sample 815 68-104 84.1 4.6 5.5 Interior 154 73-96 83.2 4.4 5.3 East 120 75-101 85.0 4.4 5.2 Coast 210 73-97 84.5 4.6 5.4 N.W. 79 68-104 83.9 5.6 6.7 Fiji (Howells) 132 74-105 84.7 5.0 6.0 Solomons (Howells) 84 74-97 84.5 4.4 5.2 Tonga (Sullivan) 116 78-102 89.3 4.4 5.0 Relative to maximum breadth, the Fijian face tends to shortness, although this is due largely to their generous facial breadth rather than absolute deficiency of height. The interior groups have the lowest values and the eastern groups show relatively broad faces. The Tongan average is much higher than any of the Fijian values, whereas the Solomon Islanders show similarity to the Fijians in this feature. _Upper Face Height_ No. Range Mean S.D. C.V. Total sample 815 56-84 70.2 5.1 7.3 Interior 154 59-79 69.1 3.9 5.6 East 120 64-83 71.7 4.0 5.6 Coast 210 59-84 70.4 6.6 9.4 N.W. 79 58-80 69.4 4.8 6.9 The ratio of the upper face height to maximum facial breadth shows the Fijians of the interior to be relatively shorter faced and the eastern people longest. The coastal and northwestern series are intermediate. _Upper Facial Index_ No. Range Mean S.D. C.V. Total sample 815 37-65 48.2 3.7 7.7 Interior 154 41-65 47.4 3.3 7.0 East 120 42-59 48.9 2.9 5.9 Coast 210 40-59 48.5 4.8 9.9 N.W. 79 39-56 47.8 3.5 7.3 The ratio of the upper face height to maximum facial breadth shows the Fijians of the interior to be relatively shorter faced and the eastern people longest. The coastal and northwestern series are intermediate. _Bigonial_ No. Range Mean S.D. C.V. Total sample 815 95-146 109.7 5.1 4.6 Interior 154 95-146 109.8 6.0 3.6 East 120 97-125 110.6 5.1 4.6 Coast 210 95-129 109.9 5.3 4.8 N.W. 79 99-119 109.1 4.5 4.1 Tonga (Sullivan) 116 92-119 104.8 5.8 5.5 Lower jaw breadth as expressed by the bigonial diameter indicates a tendency to broadness shared with little variation among all the subgroups. The Tongan value is considerably smaller. _Fronto-Gonial_ No. Range Mean S.D. C.V. Total sample 815 80-122 99.9 5.5 5.5 Interior 154 84-122 100.0 6.0 6.0 East 120 86-115 99.9 5.3 5.3 Coast 210 80-114 100.3 6.0 6.0 N.W. 79 85-113 99.8 4.8 4.8 Similarly the bigonial diameter in relation to forehead breadth is much the same in all groups, the general average nearly 100 per cent. _Zygo-Gonial_ No. Range Mean S.D. C.V. Total sample 815 65-86 75.3 4.1 5.4 Interior 154 67-86 75.4 6.0 8.0 East 120 65-82 75.4 3.5 4.6 Coast 210 66-83 75.7 3.4 4.5 N.W. 79 68-83 75.2 3.4 4.5 Tonga (Sullivan) 116 63-87 73.2 4.6 6.2 Relative to face breadth, jaw width is 75.3 per cent with very little geographic variation. _Nasal Height_ No. Range Mean S.D. C.V. Total sample 815 42-65 53.9 3.4 6.3 Interior 154 45-65 53.2 3.5 6.6 East 120 48-62 54.7 3.1 5.7 Coast 210 46-63 54.1 3.4 6.3 N.W. 79 45-61 52.9 3.5 6.6 Fiji (Howells) 133 44-63 52.4 3.9 7.4 Solomons (Howells) 85 40-59 49.9 3.8 7.7 Tonga (Sullivan) 117 47-65 57.4 3.9 6.8 The Fijian nose may be called medium long. Greatest nasal heights occur in the eastern and in the coastal series. The interior and northwestern groups have shorter noses. The Fijians of Howells' series fall near the short end of my averages. Natives of the Solomons are definitely lower in nasal height, whereas the Tongan's average is so much higher that one suspects a difference in the location of the nasion. _Nasal Breadth_ No. Range Mean S.D. C.V. Total sample 815 31-62 46.7 3.4 7.3 Interior 154 40-61 47.6 3.4 7.1 East 120 38-53 45.5 3.0 6.6 Coast 210 38-62 46.4 3.3 7.1 N.W. 79 31-57 47.4 3.6 7.6 Fiji (Howells) 133 37-54 46.19 3.0 6.0 Solomons (Howells) 85 34-51 44.6 2.8 6.3 Tonga (Sullivan) 117 38-55 44.4 3.0 6.8 Broad noses are common to most Fijians. The greatest contrast is between the narrower-nosed eastern people and the interior people, among whom the widest noses occur. The nose of the Solomon Islanders is somewhat narrower, according to Howells' data, and the Tongan average is also lower. _Nasal Index_ No. Range Mean S.D. C.V. Total sample 815 61-112 87.1 8.2 9.4 Interior 154 69-109 89.7 8.1 9.0 East 120 61-100 83.2 7.6 9.1 Coast 210 63-111 86.0 7.1 8.7 N.W. 79 63-110 89.9 8.6 9.6 Fiji (Howells) 133 68-123 88.8 8.3 9.3 Solomons (Howells) 85 68-119 87.1 8.9 10.2 Tonga (Sullivan) 117 61-98 77.6 7.6 9.8 Platyrrhini is the rule in Fiji, but individual and regional variations are great. There are some leptorrine subjects in every province, and there are some whose noses are broader than long. The interior people and the northwestern groups have the relatively broadest noses, whereas the eastern index is more moderate. The noses of Sullivan's Tongans are relatively longer than the Lauans. The Solomon Island average is identical with the Fijian. _Nasal Depth_ No. Range Mean S.D. C.V. Total sample 815 16-32 22.0 2.9 3.2 Interior 154 17-32 22.5 2.1 9.3 East 120 17-28 21.9 1.8 8.2 Coast 210 17-32 21.8 3.6 6.5 N.W. 79 16-29 22.3 1.9 8.5 Nasal depth averages 22 mm.; the regional variation is very small. _Nasal-Depth Index_ No. Range Mean S.D. C.V. Total sample 815 32-60 47.2 6.8 6.8 Interior 154 34-59 47.4 5.1 6.6 East 120 35-60 48.4 4.6 9.5 Coast 210 32-58 47.0 8.1 7.2 N.W. 79 34-58 47.2 5.5 6.7 _Mouth Breadth_ No. Range Mean S.D. C.V. Total sample 815 29-72 57.6 4.7 8.2 Interior 154 34-72 59.6 4.4 7.4 East 120 33-66 56.5 3.9 6.9 Coast 210 29-67 57.3 4.0 7.0 N.W. 79 36-65 57.3 4.4 7.8 Mouth breadth averages show the interior groups to have widest mouths, the eastern people least wide, and the coastal and northwestern people intermediate. _Lip Thickness_ No. Range Mean S.D. C.V. Total sample 815 9-45 22.4 3.8 6.9 Interior 154 12-31 23.4 3.6 5.4 East 120 12-29 21.7 3.4 5.7 Coast 210 16-45 20.8 3.6 5.3 N.W. 79 10-29 22.0 3.9 5.7 Thick lips are characteristic of most Fijians. The interior average is highest for this diameter, whereas the northwestern Fijians have least-thick lips. _Ear Length_ No. Range Mean S.D. C.V. Total sample 815 55-83 66.6 4.5 6.8 Interior 154 53-83 66.0 4.8 7.3 East 120 55-80 67.2 5.0 7.4 Coast 210 55-77 66.7 4.9 7.3 N.W. 79 57-75 66.5 3.7 5.6 Tonga (Sullivan) 117 56-81 66.0 4.6 6.9 Fijian ears on the whole tend to be long, as the average 66.6 mm. indicates. Regional differences are slight. Tongans closely resemble Fijians. _Ear Breadth_ No. Range Mean S.D. C.V. Total sample 815 24-55 34.3 3.2 9.3 Interior 154 27-41 33.7 2.5 7.4 East 120 29-40 34.1 4.0 11.7 Coast 210 29-55 34.7 3.9 11.2 N.W. 79 25-42 33.8 2.9 8.6 Tonga (Sullivan) 116 25-42 34.5 2.6 7.6 Ear breadth is also generous, and regional differences hardly exceed 1.5 mm., including the Tongans. _Ear Index_ No. Range Mean S.D. C.V. Total sample 815 38-62 51.6 5.0 9.7 Interior 154 40-61 51.1 3.6 7.0 East 120 41-59 50.6 5.8 11.5 Coast 210 42-62 52.1 6.7 12.9 N.W. 79 38-59 50.9 4.0 7.9 Tonga (Sullivan) 116 41-62 52.4 3.9 7.5 Length-breadth ear ratios indicate that coastal groups have somewhat broader, and the northwestern people the relative longest, ears. _Bicanine Breadth_ No. Range Mean S.D. C.V. Total sample 815 24-72 39.8 11.7 19.4 Interior 154 37-49 39.9 10.7 16.8 East 120 36-68 41.8 7.4 7.7 Coast 210 24-72 39.0 13.4 14.3 N.W. 79 38-49 38.6 14.0 16.3 Bicanine breadth is characteristically great among Fijians, reflecting the ample jaws and teeth. Widest diameters are seen in the east, followed by the hill people of the interior. The northwestern groups have the least bicanine diameter. MORPHOLOGICAL OBSERVATIONS PIGMENTATION _Skin Color: Exposed_ Brunet Swarthy Lt. Brn Med. Brn Dk. Brn Black Total No. % No. % No. % No. % No. % No. % Total sample 1 .01 5 .6 30 4 400 48 377 46 0 0 813 Interior 0 0 0 0 1 1 55 36 97 63 0 0 153 East 0 0 3 2 12 10 99 83 6 6 0 0 120 Coast 0 0 1 0 7 3 85 41 116 56 0 0 209 N.W. 0 0 0 0 1 1 42 53 36 46 0 0 79 Fiji II 0 0 0 0 0 0 128 96 5 4 0 0 133 Solomons 0 0 0 0 0 0 4 5 79 93 2 3 85 Tonga (Range from Lt. Brown to Dk. Brown.) Color of skin includes exposed and unexposed areas. The former was observed on the face, since the Fijians do not use any kind of face or head covering. This condition in the total series divides itself quite evenly between medium brown and dark brown. A few have light-brown skin; only six individuals are classified as swarthy and brunet. None was judged to be completely black. The Fijians of Howells' series are described as 96 per cent medium brown[15] and 5 per cent dark brown, a discrepancy I would attribute to personal judgment difference. The Solomon Islanders are markedly darker than the Fijians, the majority have dark-brown skin and 3 per cent are black, whereas 5 per cent have medium-brown complexions. Tongan data on skin color cannot be directly adjusted to my statistics. Sullivan's comment on their skin color states that it is "a medium yellowish-brown where it is unexposed to the sun. Exposed parts of the skin of a few of the persons were a very dark chocolate" (Sullivan, 1922, p. 248). Among the Fijians themselves, the greatest contrasts occur between the eastern and the interior groups of Viti Levu. Where 63 per cent of the latter have dark-brown skin, only 5 per cent of eastern fall into this category. The bulk of eastern (83 per cent) have medium-brown skin as against 36 per cent of hill people. The coastal and northwestern provinces are, like the total series, more evenly divided between medium and dark brown. _Skin Color: Unexposed_ Brunet Swarthy Lt. Brn Med. Brn Dk. Brn Black Total No. % No. % No. % No. % No. % No. % Total sample 6 1 9 1 242 30 545 66 11 1 0 0 813 Interior 0 0 0 0 20 13 133 87 0 0 0 0 153 East 3 3 4 3 77 64 36 30 0 0 0 0 120 Coast 1 1 2 1 56 27 148 71 2 1 0 0 209 N.W. 0 0 1 1 20 25 57 72 1 1 0 0 79 Fiji II 0 0 0 0 0 0 127 96 5 4 0 0 132 Solomons 0 0 0 0 0 0 9 11 74 87 2 2 85 Unexposed skin color was observed on the under surface of the upper arm near the armpit. The anticipated shift in color range results in a reduction of dark-skin incidence to a mere 1 per cent, and an increase in medium brown to 60 per cent and of light brown to 30 per cent. Howells' describes 96 per cent of his Fijians as medium brown, 4 per cent dark brown, and none light brown. The Solomon Islanders seem definitely darker than the Fijians whether they are compared with Howells' or my series. The eastern groups continues to contrast with the interior people. The former show a majority of 64 per cent in the light-brown category as compared with 13 per cent among the interior groups; the latter have a medium-brown incidence of 87 per cent against 30 per cent among Lauans. _Hair Color_ Black Dk. Brn Med. Brn Lt. Brn Red-Brown Total No. % No. % No. % No. % No. % Total sample 757 93 31 5 1 0 0 0 18 2 807 Interior 145 95 8 5 0 0 0 0 0 0 153 East 114 95 6 5 0 0 0 0 0 0 120 Coast 193 92 11 5 0 0 0 0 5 2 204 N.W. 70 89 5 6 0 0 0 0 4 5 75 Fiji II 118 91 9 7 0 0 0 0 3 2 130 Solomons 55 65 26 31 0 0 3 4 0 0 84 Tonga 0 94 0 4 0 0 0 0 0 0 0 Black hair is the usual color, although 5 per cent are described as dark brown and a few red-brown. This latter variation is a rufous color (reddish-brown) and it may be a little more frequent than the data indicate because the Fijians frequently dye their hair with a substance extracted from mangrove bark. This intensifies the usual blackness of the hair and adds a satisfying gloss. More sophisticated natives have access to modern hair dye and lacking this, some have been known to resort to black shoe polish. Hair bleaching is no longer practiced in Fiji. The hair of the Solomons Islands is not so uniformly black, nearly a third have dark-brown hair and a few are light brown. _Eye Color_ Black Dk. Brown Med. Brown Lt. Brown Total No. % No. % No. % No. % Fiji I 2 0 550 68 257 31 4 1 813 Interior 0 0 131 86 22 14 0 0 153 East 0 0 71 59 48 40 1 1 120 Coast 0 0 127 61 81 39 1 0 209 N.W. 1 1 53 67 25 32 0 0 79 Fiji II 0 0 130 98 0 0 2 2 132 Solomons 0 0 85 100 0 0 0 0 85 Tonga 0 3 0 94 0 0 0 3 A little more than two-thirds of Fijians' eyes are described as dark brown. The remaining third have medium-brown eyes. There were four individuals who were light brown. Howells, with his Fijian series, is more generous with the darker designation; he designated 98 per cent as dark brown and 2 per cent light brown. His Solomons sample is described as dark brown without exception. The Tongan data also is recorded as more uniformly dark brown than my Fijians. The Fijians of the interior of Viti Levu have more deeply pigmented eyes than the others; 86 per cent are classed as dark brown and only 14 per cent medium brown. HAIR _Hair Form_ Straight Low Wave Deep Wave Curl Frizz Wool Total No. % No. % No. % No. % No. % No. % Total sample 0 0 7 0.1 13 0.2 91 11.0 702 862 0 0 813 Interior 0 0 0 0 0 0 4 3 149 97 0 0 153 East 0 0 1 1 10 8 37 31 72 60 0 0 120 Coast 0 0 0 1 3 0 18 9 188 90 0 0 209 N.W. 0 0 2 3 0 0 7 9 70 89 0 0 79 Fiji II 0 0 0 0 0 0 19 16 38 33 59 51 116 Solomons 2 3.3 1 1.6 0 0 16 26 17 28 25 41 61 Frizzly hair is the condition of over 85 per cent of Fijians; 11 per cent are curly-haired, whereas over twenty individuals have wavy hair. Straight hair is absent. The Fiji II series of Howell distinguishes between frizzly and wooly hair, which I do not. Their combined incidence is 83 per cent, quite close to my frequency of frizzly. Whether one does or does not distinguish between frizzly and wooly hair, there is no doubt that most Fijians have Negroid hair form. The Solomon Islanders are surprising with somewhat less Negroid hair form than the Fijians. Their combined percentage of frizzly and wooly is 69, which is nearly 20 per cent less than that of the Fijians. Twenty per cent have curly hair against 11 per cent among Fijians. Also, the only instances of straight hair occur in the Solomons. In the Fijian breakdown, the interior groups have the most Negroid hair; 97 per cent have frizzly hair and 3 per cent have curly hair. The eastern people are the least Negroid in this respect; frizzly hair drops to 60 per cent, whereas curly hair advances to 30 per cent and wavy hair to 9 per cent. The coastal and northwestern series are closer to the interior groups with about 90 per cent frizzly hair. _Hair Texture_ Course Medium Fine Total No. % No. % No. % Total sample 804 99 9 1 0 0 813 Interior 153 100 0 0 0 0 153 East 116 97 4 3 0 0 120 Coast 208 100 1 0 0 0 209 N.W. 78 99 1 1 0 0 79 Hair texture is prevailingly coarse; only 1 per cent of the total series shows medium coarseness and none have fine hair. This preponderance of coarse hair is much the same in all the provinces, although the eastern people do depart slightly with a 3 per cent incidence of medium-coarse hair. It might be added that Fijian hair is quite stiff or wiry. For example, when the hair is unshorn, it stands out like a mop. A Fijian can insert a long stemmed flower in his hair and it will stay in place with no additional fastening. _Head Hair Quantity_ Absent Subm. +[16] ++ +++ Total No. % No. % No. % No. % No. % Total sample 0 0 61 7 219 27 533 65 0 0 813 Interior 0 0 26 17 27 18 100 65 0 0 153 East 0 0 5 4 24 20 91 76 0 0 120 Coast 0 0 11 5 63 30 135 65 0 0 209 N.W. 0 0 7 9 21 27 51 65 0 0 79 Fiji II 0 0 0 0 0 0 1 1 132 92 133 Solomons 0 0 0 0 0 0 5 6 80 94 85 Head hair quantity is pronounced in the majority of Fijians (65 per cent); it is moderate in 27 per cent and submedium in 7 per cent. Howells describes nearly all the Fijians as having very pronounced head hair--99 per cent, which would appear to be a personal difference in appraisal. In any case, the two series agree that Fijians have hair of more than moderate quantity. The Melanesians of the Solomons are also characterized by much head hair. Regionally, the only significant variation in this trait is shown in the east, where more individuals have a submedium designation. In the absence of age data, this contrast cannot be fairly interpreted. _Hair Length_ It might be observed here that although hair length was not included in this survey, on the basis of personal but unrecorded observation, the Fijians conform to the Melanesian pattern. Most Fijian men now cut their hair short in the Western style, but some still do not. Women generally trim their hair but not short. The natural length of head hair is intermediate between the short-haired African Negroes and the long-haired Caucasians and Mongolians. _Baldness_ Subm. + ++ +++ Total No. % No. % No. % No. % No. % Total sample 731 90 40 3 30 4 12 1 0 0 813 Interior 122 80 12 8 12 8 7 5 0 0 153 East 112 93 3 3 4 3 1 1 0 0 120 Coast 194 93 10 5 4 2 1 0 0 0 209 N.W. 72 91 1 1 3 4 3 4 0 0 79 The lack of age correlations also limits the value of data on baldness, but some meaning can nevertheless be extracted. Regardless of age, with an incidence of pronounced baldness of 1 per cent among all adult males and of 4 per cent for a moderate condition, it is a clear indication that Fijians are not prone to loss of head hair. _Beard Quantity_ Absent Subm. + ++ +++ Total No. % No. % No. % No. % No. % Total sample 0 0 234 29 370 44 208 26 1 .01 813 Interior 0 0 22 14 67 44 64 42 0 0 153 East 0 0 45 38 59 49 16 13 0 0 120 Coast 0 0 60 29 94 45 54 26 1 0 209 N.W. 0 0 22 28 30 38 27 34 0 0 79 Fiji II cheeks 27 21 2 2 44 34 46 35 12 9 131 skin 9 7 0 0 52 40 56 43 14 10 131 Solomons cheeks 21 25 0 0 42 49 22 26 0 0 85 chin 7 8 0 0 53 62 25 29 0 0 85 Tonga chin 0 0 0 19 0 31 50 0 0 0 0 lower chk. 0 4 0 37 0 18 40 0 0 0 0 Moderate beard quantity is shown by 44 per cent of Fijians; the remainder are fairly evenly divided between the submedium and pronounced categories. Howells' series, which records beard quantity for the cheeks and chin separately, shows a higher frequency of pronounced and very pronounced designations. However, his data includes many individuals who have no beards at all. Both series are doubtless influenced by the fact that they contain a preponderance of young adult; a greater proportion of older men would have greatly raised the incidence of the pronounced categories. Nearly all modern Fijians have adopted the Western practice of shaving. Examination of earlier pictures and written description of Fijians leaves no doubt that the majority of mature men possess luxurious beards when nature is unrestrained. The natives of the Solomon Islands, according to Howells, are a little less bearded than the Fijians. The Tongans are a little more heavily bearded than the Fijians. Some geographical variation is indicated by my data. The interior people of Fiji have the highest incidence of face hair; 42 per cent are recorded as pronounced. Least endowed are the eastern Fijians, where 13 per cent have pronounced beards and 38 per cent are submedium. The coastal and northwestern series conform more closely to the overall distribution. _Body Hair_[17] Absent Subm. + ++ +++ Total No. % No. % No. % No. % No. % Total sample 0 0 243 30 328 40 162 20 80 10 813 Interior 0 0 31 20 56 37 41 27 25 16 153 East 0 0 55 46 45 38 14 12 6 5 120 Coast 0 0 57 27 82 39 46 22 24 11 209 N.W. 0 0 16 20 36 46 19 24 8 8 79 Tonga 0 0 23 29 0 26 0 22 0 0 0 The body hair endowment is also not unimpressive. Forty per cent show a moderate condition, 20 per cent are pronounced, and 10 per cent very pronounced; none are totally devoid of body hair; 30 per cent are submedium. Chest hair among the Tongans is somewhat less in evidence; although the majority range from submedium to pronounced, 23 per cent are described as hairless. The provincial distribution in Fiji follows that of face hair: the interior groups are hairiest and the eastern people least so. The anatomical distribution of body hair deserves some comment, even though specific observations were made on the chest. Not infrequently the hair is heavier on the upper legs than on the chest. Occasionally, too, the back of the shoulders is quite hairy as well as the belly. _Grayness: Head_ Absent Subm. + ++ +++ Total No. % No. % No. % No. % No. % Total sample 621 76 82 10 82 10 28 3 3 3 813 Interior 80 52 37 24 19 12 17 11 0 0 153 East 91 76 13 11 16 13 0 0 0 0 120 Coast 176 84 14 7 17 8 2 1 0 0 209 N.W. 60 76 8 10 9 11 2 3 0 0 79 _Grayness: Beard_ Absent Subm. + ++ +++ Total No. % No. % No. % No. % No. % Total sample 610 75 61 8 90 11 52 6 0 0 813 Interior 72 47 30 20 20 13 31 20 0 0 153 East 89 74 9 8 18 15 4 3 0 0 120 Coast 178 85 8 4 21 10 2 1 0 0 209 N.W. 60 76 6 8 11 14 2 3 0 0 79 Grayness of the hair data without corresponding age incidence is not particularly significant. It is clear, nevertheless, that premature grayness is not common. I would hazard the judgment that on the whole the Fijians show less tendency to grayness than do Caucasians. The higher incidence of grayness of the interior sample of Fijians is likely due to a larger number of older men in that series. THE FACE _Prognathism: Total_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 206 25 306 38 288 35 13 2 813 Interior 40 26 59 39 52 34 2 1 153 East 54 45 55 46 11 9 0 0 120 Coast 47 22 84 40 73 35 5 2 209 N.W. 18 23 29 37 32 41 0 0 79 Tonga 63 53 26 22 29 25 0 0 118 _Prognathism: Mid-Facial_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 517 64 184 23 109 13 3 1/2 813 Interior 133 87 15 10 5 3 0 0 153 East 100 83 17 14 3 3 0 0 120 Coast 122 58 49 23 37 18 1 1 209 N.W. 48 61 20 25 11 14 0 0 79 _Prognathism: Alveolar_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 798 98 9 1 4 1/2 2 0 813 Interior 153 100 0 0 0 0 0 0 153 East 120 100 0 0 0 0 0 0 120 Coast 207 99 0 0 1 1/2 1 1/2 209 N.W. 76 {96} 2 3 0 0 1 1 79 Slight and moderate total prognathism characterizes most Fijians but it is pronounced in only 13 of the 813 subjects. A quarter of the series show no prognathism. The eastern people are least prognathic with a zero incidence of 45 per cent. The other regional sample are close to the general condition. Mid-facial prognathism has a submedium incidence of 23 per cent and a medium of 13 per cent; the remainder lack the condition, except three individuals who are pronounced. The coastal and northwestern groups have more frequent medium designations. Alveolar prognathism is almost entirely lacking in all groups. _Malar Projection: Lateral_ Absent Subm. + ++ +++ Total No. % No. % No. % No. % No. % Fiji I 1 0 2 0 264 32 543 67 3 0 813 Interior 0 0 0 0 62 41 91 59 0 0 153 East 0 0 0 0 25 21 95 79 0 0 120 Coast 0 0 0 0 68 33 141 67 0 0 209 N.W. 0 0 0 0 28 35 50 63 1 1 79 _Malar Projection: Frontal_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 4 1/2 0 0 709 87 100 12 809 Interior 0 0 0 0 139 91 14 9 153 East 0 0 0 0 103 86 17 14 120 Coast 1 0 0 0 181 87 27 13 209 N.W. 0 0 0 0 67 85 12 15 79 The facial contours generally include lateral malar projection; two-thirds show a pronounced condition and the balance are medium. The eastern people have high cheek bones oftener than do the others. Frontal malar projection is also common but more often moderately so; 87 per cent show medium projection and 12 per cent are pronounced. _Gonial Angles_ Subm. + ++ +++ Total No. % No. % No. % No. % Fiji I 24 3 459 56 325 40 5 1 813 Interior 0 0 97 63 55 36 1 1 153 East 1 1 65 54 54 45 0 0 120 Coast 7 3 110 53 90 43 2 1 209 N.W. 3 4 49 62 27 34 0 0 79 _Palate Shape_ Parabolic Sm. U Lg. U Square Total No. % No. % No. % No. % Fiji I 493 61 2 0 303 37 15 2 813 Interior 94 61 0 0 59 39 0 0 153 East 81 68 0 0 38 32 1 1 120 Coast 131 63 0 0 71 34 7 3 209 N.W. 50 63 1 1 27 34 1 1 79 A fairly strong tendency to well-developed gonial angles is indicated; 40 per cent show pronounced angles and nearly all the rest are medium. These proportions hold pretty much for all groups. Palate shape also attests to the well-developed jaws of Fijians; it is a large U in 37 per cent of the subjects; 2 per cent are square and the remainder parabolic. _Chin Prominence_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 2 0 164 20 593 73 54 7 813 Interior 0 0 36 24 110 72 7 5 153 East 0 0 25 21 89 74 6 5 120 Coast 0 0 41 20 153 73 13 6 207 N.W. 1 1 11 14 55 70 9 11 76 _Chin Type_ Median Bilateral Total No. % No. % Fiji I 673 83 140 17 813 Interior 130 85 23 15 153 East 112 93 8 7 120 Coast 162 78 45 22 207 N.W. 62 82 14 18 76 A well-developed chin further typifies most Fijian faces; nearly three-quarters have a moderate chin prominence, 7 per cent are pronounced, and the remainder are submedium. This range is much the same in the subgroups. The chin is commonly median although 17 per cent have the bilateral type. The bilateral chin is least frequent in Lau (7 per cent). THE HEAD _Temporal Fullness_ Absent Subm. + Total No. % No. % No. % Fiji I 1 0 563 69 249 31 813 Interior 0 0 113 74 40 26 153 East 0 0 70 58 50 42 120 Coast 1 0 148 71 60 29 208 N.W. 0 0 59 75 20 25 79 _Occipital Protrusion_ Absent Subm. + Total No. % No. % No. % Fiji I 13 2 775 95 25 3 813 Interior 4 3 149 97 0 0 153 East 0 0 116 97 4 3 120 Coast 3 1 193 92 13 6 209 N.W. 0 0 79 100 0 0 79 A narrowness in the temporal part of the head is indicated. Sixty-nine per cent of the subject show submedium temporal fullness, whereas the remainder are moderate. This condition is not marked and may best be described as a discernable tendency. The back of the head is generally rather flat as the 95 per cent incidence of occipital protrusion indicates. This is a natural condition; no intentional flattening is practiced by Fijians. _Lambdoidal Flattening_ Absent Subm. + Total No. % No. % No. % Fiji I 754 93 32 4 27 3 813 Interior 153 100 0 0 0 0 153 East 113 94 5 4 2 2 120 Coast 188 90 13 6 8 4 209 N.W. 72 91 3 4 4 5 79 _Occipital Flattening_ Absent Subm. + Total No. % No. % No. % Fiji I 809 100 2 0 2 0 813 Interior 153 100 0 0 0 0 153 East 120 100 0 0 0 0 120 Coast 209 100 0 0 0 0 209 N.W. 79 99 0 0 1 1 79 _Median Sagittal Crest_ Absent Subm. + Total No. % No. % No. % Fiji I 600 74 177 22 36 4 813 Interior 96 63 46 30 11 7 153 East 109 91 10 8 1 1 120 Coast 160 77 43 21 6 3 209 N.W. 53 57 24 30 2 3 79 _Parietal Bosses_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 17 2 413 51 381 47 2 0 813 Interior 1 1 130 85 22 14 0 0 153 East 4 3 66 55 50 42 0 0 120 Coast 6 3 82 39 120 57 1 0 209 N.W. 1 1 40 51 38 48 0 0 79 A median sagittal crest though not striking is recorded in a number of cases. It has a submedium incidence of 22 per cent and pronounced 4 per cent. Among the interior people, the crest is more common. Because of the heavy, bushy, and wiry hair of Fijians it is probable that some instances of this feature were not detected by simple palpation, and the incidence may be higher than the data indicate. Submedium development of the parietal bosses is rather common occurring in 51 per cent of the series. It is very common in the interior (85 per cent). _Cranial Asymmetry_ Absent Left Right Total No. % No. % No. % Fiji 813 100 0 0 0 0 813 Interior 153 100 0 0 0 0 153 East 119 100 0 0 0 0 119 Coast 208 100 0 0 0 0 208 N.W. 79 100 0 0 0 0 79 _Facial Asymmetry_ Absent Left Right Total No. % No. % No. % Fiji 806 100 1 0 0 0 807 Interior 153 100 0 0 0 0 153 East 117 98 0 0 2 2 119 Coast 206 99 0 0 2 1 208 N.W. 78 99 1 0 0 0 79 Cranial and facial assymetry are generally lacking, at least in any marked degree. Normal asymmetries of the face and head were ignored in this description. EYES _Eye Folds: External_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji 804 98 5 1 4 1 0 0 813 Interior 152 99 0 0 1 1 0 0 153 East 119 99 0 0 1 1 0 0 120 Coast 209 99 1 1 1 1 0 0 208 N.W. 78 99 0 0 1 1 0 0 79 _Eye Fold: Median_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 782 96 3 1/2 25 3 3 1/2 813 Interior 152 99 0 0 1 1 0 0 153 East 108 90 1 1 10 8 1 1 120 Coast 202 97 1 0 5 2 1 0 209 N.W. 78 99 0 0 0 0 1 1 79 _Eye Folds: Internal_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 778 96 4 0 30 4 1 0 813 Interior 151 99 0 0 2 1 0 0 153 East 102 85 1 1 17 14 1 0 120 Coast 203 97 0 0 6 3 0 0 209 N.W. 78 99 0 0 1 1 0 0 79 Fiji II 116 89 7 5-1/2 7 5-1/2 0 0 130 Solomons 80 94 2 2-1/2 3 3-1/2 0 0 85 Tonga 63 57 33 30 9 8 6 5 111 Eye folds are not a feature of the Fijian facial make-up. The external fold is present in only 2 per cent of the total series. The median fold shows a 96 per cent absence. The eastern groups exceed the other provinces with a 10 per cent occurrence. The internal eye fold has a total presence of 4 per cent and is also commoner in the east (14 per cent). _Eye Obliquity_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 251 31 358 43 201 25 3 1 813 Interior 92 60 46 30 14 9 1 1 153 East 33 28 52 35 45 38 0 0 120 Coast 47 22 102 49 58 28 2 1 209 N.W. 27 34 32 41 20 25 0 0 79 _Eye Opening_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 0 0 75 9-1/2 737 91 1 1/2 813 Interior 0 0 24 16 128 84 1 1 153 East 0 0 13 11 107 89 0 0 120 Coast 0 0 9 4 200 96 0 0 209 N.W. 0 0 7 9 72 91 0 0 79 Some degree of eye obliquity is present in the majority of cases; 43 per cent show a submedium condition; 25 per cent are medium and three individuals have pronouncedly oblique eyes. The remainder, or 31 per cent, have no obliquity. In the east, the natives depart from this total distribution in opposite directions. The interior groups have much less eye obliquity; the eastern people, a great deal more. The other provinces are quite close to the total frequencies. Eye opening height is preponderately moderate (91 per cent). The remaining 10 per cent with one exception show submedium eye opening. Regional variation is not great. The eastern and interior groups have a little higher frequency in the submedium class. FOREHEAD _Brow Ridges_ Absent Subm. + ++ +++ Total No. % No. % No. % No. % No. % Fiji I 0 0 148 19 364 44 295 36 6 1 813 Interior 0 0 16 10 69 45 64 42 4 3 153 East 0 0 28 23 42 35 50 42 0 0 120 Coast 0 0 42 20 99 47 67 32 1 0 209 N.W. 0 0 19 24 40 51 19 24 1 1 79 Brow ridges are a marked feature of Fijians in general. None of them lack some supraorbital development. Forty-four per cent have medium brow ridges, 36 per cent are pronounced, and 1 per cent are very pronounced. The other 19 per cent are small. The interior and eastern groups share a little higher incidence of pronounced brow ridges; the other regions are nearer the total distribution of variations. _Forehead Height_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 0 0 444 55 369 45 0 0 813 Interior 0 0 90 59 63 41 0 0 153 East 0 0 68 57 52 43 0 0 120 Coast 0 0 110 53 99 47 0 0 209 N.W. 0 0 46 58 33 42 0 0 79 _Forehead Slope_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 8 1 280 34 460 56 65 8 813 Interior 0 0 53 35 87 57 13 8 153 East 0 0 38 32 72 60 10 8 120 Coast 4 2 78 37 113 54 14 7 209 N.W. 2 3 27 34 47 59 4 4 79 Tonga 1 1 70 60 45 39 0 0 116 Forehead height is submedium in more than half the cases (55 per cent); the others are all medium. There is no significant variation among the subgroups. A sloping forehead is quite characteristic of the Fijian head; 56 per cent are moderately sloping, 8 per cent are pronounced, and 34 per cent are submedium. Only 1 per cent have foreheads with no recession. Regional differences are very slight. NOSE _Nasion Depression_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 1 0 170 21 579 71 63 8 813 Interior 0 0 41 27 103 67 9 6 153 East 1 1 32 27 85 71 2 2 120 Coast 0 0 45 22 144 69 10 10 209 N.W. 0 0 18 23 56 71 6 6 79 _Root Height_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 1 0 63 8 555 67 194 24 813 Interior 0 0 16 10 96 63 41 27 153 East 1 1 3 3 77 64 39 33 120 Coast 0 0 10 5 157 75 42 20 209 N.W. 0 0 4 5 57 72 18 23 79 _Root Breadth_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 0 0 1 0 258 32 554 68 813 Interior 0 0 0 0 38 25 115 75 153 East 0 0 1 1 53 44 66 55 120 Coast 0 0 0 0 67 32 142 68 209 N.W. 0 0 0 0 24 30 55 70 79 _Nasal Septum_ Straight Concave Convex Total No. % No. % No. % Fiji I 777 99 0 0 36 4 813 Interior 153 100 0 0 0 0 153 East 118 98 0 0 2 2 120 Coast 196 94 0 0 13 6 199 N.W. 78 99 0 0 1 1 79 _Bridge Height_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 0 0 54 7 644 79 115 14 813 Interior 0 0 13 8 124 81 16 10 153 East 0 0 1 1 98 82 21 18 120 Coast 0 0 10 5 173 83 26 12 209 N.W. 0 0 7 9 60 76 12 15 79 Tonga 0 0 21 22 81 70 9 8 111 _Bridge Breadth_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 0 0 0 0 265 33 546 67 813 Interior 0 0 0 0 29 19 124 81 153 East 0 0 0 0 72 60 48 40 120 Coast 0 0 0 0 62 30 147 70 209 N.W. 0 0 0 0 23 29 56 71 79 _Nasal Profile_ Concave Straight Convex Total No. % No. % No. % Fiji I 14 2 625 77 173 21 812 Interior 0 0 123 80 30 20 153 East 1 1 88 73 31 26 120 Coast 4 2 171 82 34 16 209 N.W. 1 1 59 75 19 24 79 Moderate nasion depression characterizes the majority of noses (71 per cent). Pronounced depression is recorded for 8 per cent, and submedium occurrence in 21 per cent. Only one individual lacks any depression. This distribution does not vary much among the provinces. A well-elevated nasal root is also characteristic; 67 per cent show moderate elevation and 24 per cent pronounced, whereas 8 per cent are submedium; one individual is without any elevation. The interior Fijians have a little higher frequency of low nasal root (10 per cent), whereas the eastern people, with a 30 per cent incidence, excel in the pronounced category. More striking is the breadth of the Fijian nasal root. It is pronounced in 68 per cent and moderate in the remainder of the series. Pronounced breadth is commoner among the interior people (75 per cent) and least preponderant in the east (55 per cent). The nasal septum is nearly always straight; the only departure from this condition is a 4 per cent incidence of convexity. Regional differences are not significant. Nasal bridge height is commonly medium (79 per cent) in the totality of noses. Fourteen percent are pronouncedly high and 7 per cent are submedium. The several provinces do not depart very far from this distribution. The Fijian nose shows a strong tendency to broadness of the bridge. Two-thirds show pronounced breadth of bridge and the remainder are medium. Pronounced broadness increases in the interior groups (81 per cent) and shows a marked decline in the east (40 per cent). Nasal profiles are most often straight (77 per cent), but convex noses are not uncommon (21 per cent). Convexity is slightly more frequent in the east (26 percent), whereas in the coastal people its incidence drops to 16 per cent. _Nasal-Tip Thickness_ Subm. + ++ +++ Total No. % No. % No. % No. % Fiji I 1 0 344 42 461 58 1 0 812 Interior 0 0 55 36 98 64 0 0 153 East 1 1 80 67 39 33 0 0 120 Coast 0 0 94 45 114 55 1 1 209 N.W. 0 0 27 34 52 66 0 0 79 _Nasal-Tip Inclination_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 731 90 57 7 24 3 0 0 812 Interior 147 96 6 4 0 0 0 0 153 East 109 91 6 5 5 4 0 0 120 Coast 186 89 16 8 7 3 0 0 209 N.W. 71 90 6 8 2 3 0 0 79 _Nasal Wings_ Compressed Medium Flaring Total No. % No. % No. % Fiji I 0 0 198 24 615 76 813 Interior 0 0 25 16 128 84 153 East 0 0 70 58 50 42 120 Coast 0 0 42 20 167 80 209 N.W. 0 0 16 20 63 80 79 The nasal tip is pronounced more often than not, 58 per cent showing this condition. The remaining 42 per cent have tips of medium thickness. Thicker tips occur more often in the interior (64 per cent) and in the northwest (66 per cent), least often in the east (33 per cent). Usually the nasal tip is not inclined downward. Slight and moderate inclination has a combined incidence of only 10 per cent. Flaring nasal wings are a common condition (76 per cent). This incidence rises to 84 per cent in the interior and drops to 42 per cent in the east. MOUTH _Lip Thickness: Membranous_ Subm. + ++ +++ Total No. % No. % No. % No. % Fiji I 19 2 428 53 364 45 2 0 813 Interior 10 7 43 28 100 65 0 0 153 East 1 1 83 69 36 30 0 0 120 Coast 1 1/2 88 42 119 57 1 1/2 209 N.W. 4 5 39 49 36 46 0 0 79 Tonga 12 10 97 84 7 6 0 0 116 _Lip Thickness: Integumental_ Subm. + ++ +++ Total No. % No. % No. % No. % Fiji I 4 1/2 608 75 201 25 0 0 813 Interior 1 1/2 114 75 38 25 0 0 153 East 1 1 100 83 19 16 0 0 120 Coast 2 1 164 78 43 21 0 0 209 N.W. 0 0 55 70 24 30 0 0 79 Fiji II 0 0 1 1/2 26 20 106 80 133 Solomons 0 0 0 0 12 14 73 86 85 _Lip Eversion_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 12 1 333 41 444 55 24 3 813 Interior 0 0 63 41 88 58 2 1 153 East 8 7 77 64 35 29 0 0 120 Coast 0 0 63 30 138 66 8 4 209 N.W. 1 1 26 33 51 65 1 1 79 _Lip Seam_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 33 4 429 53 343 42 8 1 813 Interior 1 1 79 52 73 48 0 0 153 East 14 12 77 64 29 24 0 0 120 Coast 6 3 105 50 94 45 4 2 209 N.W. 3 4 44 56 32 41 0 0 79 Fijian lips are Negroid in thickness in many instances. Membranous lips are thick in 45 per cent of the series, medium in 53 per cent, and submedium in 25 per cent. Thickest lips occur in the interior and coastal areas where the pronounced type registers 65 per cent and 57 per cent, respectively. In the east, lips are more moderate in thickness, and the pronounced category drops to 30 per cent. Integumental lips also tend to be heavy but not so much as the mucous parts. Twenty-five per cent of the total Fijians have thick integumental lips and the remainder are moderate. Howells' Fiji II series classes 80 per cent as very pronounced and the remainder as pronounced. The Solomon Islanders, with an 86 per cent incidence of very pronounced, have the heaviest lips of all. Lip eversion varies largely between moderate and submedium, 55 percent and 41 per cent, respectively. The interior and coastal Fijians show this trait a little more often than the others, whereas the eastern people have least lip eversion. The lip seam is present in nearly all cases, but not to a pronounced degree. Fifty-three per cent are submedium and 42 per cent are moderate. The eastern groups are definitely less endowed with this trait. The other provinces vary but little from the total distribution. TEETH _Bite_ Under E-E Subm. over + over Total No. % No. % No. % No. % Fiji I 2 0 518 64 274 34 13 2 807 Interior 0 0 94 61 59 39 0 0 153 East 0 0 73 61 45 38 2 2 120 Coast 1 0 130 62 76 36 0 0 207 N.W. 1 1 49 62 23 29 3 4 76 Fiji II 4 3 50 38 77 59 0 0 131 Solomons 1 1 37 45 45 54 0 0 83 _Caries_ Absent Subm.(1-4) + (5-8) ++ (9-16) +++ (17-x) Total No. % No. % No. % No. % No. % Fiji I 645 78 80 10 58 7 22 3 8 1 813 Interior 130 84 16 10 3 2 1 1 3 2 153 East 100 83 10 12 4 3 2 1 4 3 120 Coast 153 73 29 14 16 8 8 4 3 1 209 N.W. 62 80 9 11 6 8 1 1 0 0 78 _Crowding_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 685 84 115 14 13 2 0 0 813 Interior 134 88 19 12 0 0 0 0 153 East 100 83 17 14 3 3 0 0 120 Coast 180 86 25 12 4 2 0 0 209 N.W. 64 81 14 18 0 0 0 0 78 _Tooth Eruption_ Complete Incomplete Total No. % No. % Fiji I 796 98 15 2 811 Interior 153 100 0 0 153 East 119 99 1 1 120 Coast 199 95 8 4 207 N.W. 74 94 2 3 76 _Wear_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 184 23 443 54 144 18 42 5 813 Interior 27 {18} 58 {38} 37 {24} 31 {20} 153 East 26 {22} 69 {57} 24 {20} 1 {1} 120 Coast 60 {29} 120 {57} 28 {13} 1 {1/2} 209 N.W. 12 {15} 47 {60} 17 {22} 2 {3} 78 The jaws of Fijians have a rather distinctive frequency of edge-to-edge bite. I recorded this as 64 per cent, but Howells' series indicates a 38 per cent incidence. The quality of Fijian teeth as reflected by frequency of caries is excellent. Nearly 80 per cent of the total show no tooth decay. The soundest teeth from this standpoint occur in the interior, the east, and the northwest. The coastal people show the highest incidence of caries, an interesting point since many of this sample come from around Suva and have more access to the Western processed foods. Tooth crowding is quite uncommon to Fijians, a condition consistent with their generous jaw conformation. Crowding is noted in only 16 per cent of the series, and most of it is slight. Tooth eruption is complete in nearly all the subjects. A 2 per cent incidence of incomplete eruption is entirely due to the immaturity of some of the young adults. No pathological suppression was noted. Some wear of the teeth is recorded for more than three-quarters of the series, but lacking age incidence, the data has limited meaning. The Fijian diet is not abrasive the way, for instance, it is for the Indians of our Southwest, where the staple food is ground in stone mills. EARS _Ear Helix_ Subm. + ++ +++ Total No. % No. % No. % No. % Fiji I 230 28 511 63 72 9 0 0 813 Interior 45 29 99 65 9 6 0 0 153 East 29 24 74 62 17 14 0 0 120 Coast 58 28 128 61 23 11 0 0 209 N.W. 24 30 51 65 4 5 0 0 79 _Darwin's Point_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 761 94 36 4 15 2 1 0 813 Interior 150 98 3 2 0 0 0 0 153 East 112 93 6 5 2 2 0 0 120 Coast 187 89 13 6 4 4 1 0 209 N.W. 77 97 2 3 0 0 0 0 79 _Ear-Lobe Type_ Soldered Attached Free Total No. % No. % No. % Fiji I 80 10 531 65 202 25 813 Interior 47 31 74 48 32 21 153 East 3 3 85 71 32 27 120 Coast 9 4 141 67 59 28 209 N.W. 5 6 52 66 22 28 79 _Ear-Lobe Size_ Subm. + ++ +++ Total No. % No. % No. % No. % Fiji I 176 22 457 56 178 22 2 0 813 Interior 49 32 66 43 38 25 0 0 153 East 16 13 76 63 27 23 1 1 120 Coast 31 15 123 59 55 26 0 0 209 N.W. 20 25 47 59 12 15 0 0 79 _Ear Protrusion_ Absent Subm. + ++ Total No. % No. % No. % No. % Fiji I 2 0 262 32 463 57 86 11 813 Interior 1 1 47 31 90 59 15 10 153 East 0 0 31 26 77 64 12 10 120 Coast 1 0 75 36 114 55 19 9 209 N.W. 0 0 26 33 49 62 4 5 79 _Ear Slant_ Absent Subm. + Total No. % No. % No. % Fiji I 416 51 332 41 65 8 813 Interior 78 51 67 44 8 5 153 East 55 46 52 43 13 11 120 Coast 118 56 74 35 17 8 209 N.W. 38 48 39 49 2 3 79 The Fijian ear is a moderately distinctive appendage from a racial standpoint. The helix shows moderate development on the whole and is submedium otherwise except for a 9 per cent incidence of pronounced appearance. Regional variation is small. The Darwin's point is noted in a number of cases: 4 per cent to a submedium degree and 2 per cent medium. The ear lobe is somewhat distinctive with a 65 per cent incidence of the attached condition and 10 per cent soldered. The remaining 25 per cent is free. This distinctiveness is more marked among the interior groups where the soldered type of lobe increases to 31 percent. Ear-lobe size is moderate in more than half the series, pronounced in 22 per cent, and submedium in 22 per cent. Small lobes are commoner in the interior province. Moderate ear protrusion is the commonest form followed by submedium. Marked projection is recorded as 11 per cent. Ear slant either is lacking or slight in most instances; the series is rather evenly divided between these two categories, the zero category having a small majority. Moderate slant is noted for 8 per cent. BODY BUILD _Body Build: Endomorph_ 1 2 3 4 5 6 Total No. % No. % No. % No. % No. % No. % Fiji I 260 32 334 42 126 15 46 6 33 4 12 1 811 Interior 49 32 66 43 26 17 5 3 6 4 1 1 153 East 30 25 54 45 21 18 5 4 8 7 1 1 119 Coast 77 37 82 39 28 13 10 5 8 4 3 1 209 N.W. 26 33 34 43 9 11 6 8 2 3 2 3 79 _Body Build: Mesomorph_ 1 2 3 4 5 6 Total No. % No. % No. % No. % No. % No. % Fiji I 1 {0.1} 2 {0.2} 33 4 131 16 227 28 419 52 813 Interior 0 0 1 1 11 7 27 18 41 27 73 48 153 East 1 1 0 0 2 2 14 12 38 32 65 54 120 Coast 0 0 0 0 9 4 29 14 67 32 104 50 209 N.W. 0 0 1 1 2 3 15 19 14 18 47 59 79 _Body Build: Ectomorph_ 1 2 3 4 5 6 Total No. % No. % No. % No. % No. % No. % Fiji I 351 43 195 24 110 14 88 11 68 8 1 {0.1} 813 Interior 54 35 56 37 13 8 15 10 15 10 0 0 153 East 49 41 33 28 15 13 12 10 11 9 0 0 120 Coast 84 40 51 24 36 17 18 9 19 9 1 1 209 N.W. 39 49 19 24 11 14 6 8 4 5 0 0 79 Variations in body build have been expressed with the Sheldon method of somatotyping.[18] Accordingly, the Fijians are primarily and definitely mesomorphic, with endomorphy the second strongest component, and ectomorphy, third. About 80 per cent of the total series had a mesomorphic rating of 5 and 6 which leaves no doubt as to the prevailingly athletic physique. Endomorphy is seldom pronounced so that obesity may be described as no more than occasional. A pronounced linear build is likewise relatively infrequent. The Fijian subgroups do not vary markedly from the over-all pattern. SUMMARY The preceding data may be summarized from three points of view. The first will emphasize the physical features that are common to most Fijians. At the outset it should be pointed out that a "typical" Fijian does not exist, except as a statistical abstraction. The racial composition of the Fijian is complex and far from being homogeneous. There is no doubt, from the physical and cultural evidence, as well as the geographical location, that Fijians are related to both Melanesians and Polynesians. The second point is to give a precise indication of these affinities with Melanesia and Polynesia. A third concern of this analysis is the geographical variability within Fiji. This consists of a regional breakdown of the Fijian data into interior, eastern, coastal, and northwestern divisions, in order to demonstrate some of the local variation of the Melanesian-Polynesian ingredients and their possible meaning. _Body (pl. 1)._--In general size and appearance, the Fijian is tall and well proportioned. His body is fairly tall and well muscled, that is, predominately athletic in build. Obesity is relatively uncommon except in moderate degrees. This rather tall stature allies the Fijians more closely with the Polynesians. Shoulder, chest, and hip diameters also indicate that Fijians are generously endowed. The Fijians who occupy the mountainous interior of the main island are less tall than the coastal and eastern people; they also have narrower shoulders, relatively deeper and narrower chests, whereas their arms and legs are somewhat shorter. The eastern Fijians are tallest of all subgroups. _Skin Color._--Most Fijians have either medium- or dark-brown skin on the exposed facial surfaces. The more protected body areas show higher frequencies of medium brown and light brown. The Fijians are definitely less dark than the Melanesians but are darker, on the whole, than the Polynesians. The interior hill tribes are darker than the eastern and coastal groups. The lightest average skin shade occurs in the east. _Hair (pls. 6 and 7)._--In several respects the hair is the most consistent endowment of the Fijians. In nearly all instances it is black, frizzly, and coarse. The only departure from this condition is an occasional instance of dark brown and a few instances of rufous shade. Curly hair is a more common exception in the east. The coastal and northwestern people are nearer to the interior condition of frizzly hair. All in all, the hair form is definitely Melanesian. Hair length conforms to the general Melanesian condition, that is, intermediate between short Negroid and long Caucasiod or Mongoloid. Considerable beard and body hair is common to Fijians (pls. 8 and 9). Moderate to pronounced beard is shown by nearly three-quarters of the total series, and body hair is even more prevelant. General hairiness is also exhibited by the Solomon Islanders and the Tongans in the comparative data. The interior tribes of Fiji are more hairy than the other groups. This prevelence of body and face hair seems to conform to parts of Melanesia where it may be regarded as an Australoid element. Its presence in the Tongan data does not seem to be representative of other Polynesians, who are generally described as more glabrous. _Head (pl. 2)._--Moderate brachycephaly is the commonest head form of Fijians, although the total range is great. In this respect the Fijians resemble the broad-headed Tongans, and are quite distinct from the longer-headed Melanesians. The Fijian head, despite its general brachycephaly, is rather compressed in the temporal area and submedium in parietal elevation. The back of the cranium is characteristically flattened, a natural conformation as no deformation is practiced. The interior mountain tribes of Fiji have narrower heads and lower cranial indices than do the coastal and eastern groups. The interior people also have lesser head heights and a higher breadth-height index. _Forehead (pl. 10)._--Moderate to strongly developed supraorbital ridges are a common Fijian endowment. Similarly are low and sloping foreheads. These features have been observed in western Melanesia, where, like hairiness, they suggest Australoid of archaic Caucasoid elements. _Face._--Broadness characterizes the Fijian face. Bizygomatic breadth locates them nearer to the Polynesians than to the narrower-faced Melanesians. Strongly developed malars are common, and they tend to project laterally more than frontally. Widest faces appear among the eastern people. Bigonial and bicanine widths show that generous breadth includes the lower parts of the face, a condition born out by strong gonial angles. Face length falls between the long-faced Tongans and the definitely shorter-faced Melanesians (pls. 3 and 4). Some prognathism is common among Fijians, both total and mid-facial, but the condition is not universal nor pronounced. The eastern Fijians are the least prognathic (pl. 10). _Eyes._--Dark brown is the prevailing eye color, although many subjects have medium-brown eyes. Eye folds are only occasional and eye-opening height is usually moderate. Slight eye obliquity is common, more so in the eastern sample. _Nose (pl. 4)._--Great variability marks the nasal area. The commonest condition is a broad and moderately long nose. Medium nasion depression is frequent; the root is wide and moderately elevated. Bridge breadth is often pronounced and the nasal profile is straight to convex. The nasal tip is characteristically thickened and nasal wings are usually flaring. On the whole, there is a great deal of Melanesian in the Fijian nose; it is Negroid, but not pronouncedly. Those aspects of the nose which may be termed Negroid are commoner in the interior hill people and the northwest and least evident in the east. _Lips (pl. 5)._--Thick and moderately everted lips occur in nearly half the series. This Negroid combination is more manifest in the interior and least in the east. Integumental lips tend to be heavy. _Teeth._--The condition of the teeth is generally excellent. Most Fijians have broad, roomy jaws that permit complete and uncrowded tooth development. Dental caries are very infrequent. A rather high incidence of edge-to-edge bite is interesting. _Ears (pl. 5)._--The ears are usually moderate in length and tend to protrude. Ear lobes are commonly large and are more often attached or soldered than free. CONCLUSIONS On the whole the Fijians are predominately Melanesian but with numerous Polynesian affinities that vary with locality. The Melanesian qualities are in part Negroid or Negritoid and in part Australoid. The Negroid resemblances are best illustrated by frizzly black hair, broad noses with depressed nasion and flaring nostrils, thick lips, and dark pigmentation (pls. 11 and 12). Australoid elements are general hairiness, strong brow ridges, low, sloping foreheads, compressed parietal and temporal areas, and some prognathism (pl. 13). The presence of Australoid suggestions need not mean that they come from Australia, but that they form a part of the Melanesian make-up. This interpretation of the Melanesians as a hybrid people conforms with similar designations by such students as Birdsell[19] and Hooton.[20] Polynesian influence in Fiji is most clearly demonstrated by lighter pigmentation, tall and muscular body build, moderate brachycephaly, broad faces and jaws, high and fairly long noses and strong chins. I found much the same resemblances between Fijians and Polynesians as did Howells;[21] however, in my comparisons the Polynesian similarities are outweighed and outnumbered by a greater array of Melanesian characters. The essential Melanesian character of the Fijian population is further demonstrated by recent blood-analysis comparisons; the conclusions of Simmons _et al._, identify the Fijians as Melanesian.[22] The Fijians who live in the interior of Viti Levu show the most frequent Melanesian traits (pls. 11 and 14). These people are shorter, have narrower shoulders and chests; their heads are narrower and lower vaulted; they have broader noses, thicker lips, are hairier, and have darker skins. This condition, occurring as it does in the mountainous interior, which may be regarded as a refuge area, supports the theory that the Melanesian is the earlier component in Fiji. The eastern Fijians stand in considerable contrast to the interior tribes and are the most Polynesian in appearance (pl. 15). They have lighter skins, greater stature, and heavier musculature. Their heads are broader, as are their faces and jaws; their noses are larger, narrower, and higher bridged, and their chins are more pronounced. The coastal sample might be called intermediate or a more even blend of Melanesian and Polynesian. The northwestern people resemble the coastal tribes. This means they show fewer departures in either a Melanesian or Polynesian direction. This also means they do not tell us whether the legendary ancestors, who are supposed to have first landed in Fiji on the northwest coast of Viti Levu,[23] were Melanesian or Polynesian. These data may mean one of three things: (1) the Fijian tradition of a landing at this place eight or ten generations ago is groundless, (2) the immigration did take place but whatever racial traits predominated, whether Melanesian or Polynesian, have been homogenized and obscured by subsequent intermixture and by movements back and forth on Viti Levu, (3) the landing did occur but the ancestors were already a Melanesian-Polynesian blend when they arrived. LITERATURE CITED Birdsell. J. B. 1948. Racial Origin of the Extinct Tasmanians. Records of the Queen Victoria Museum, Tasmania, Vol. II, No. 3. Churchill, W. 1911. The Polynesian Wanderings. Carnegie Institute of Washington, Publ. No. 134, Washington. Derrick, R. A. 1951. History of Fiji. Printing and Stationery Dept., Suva, Fiji. Fornander, A. 1878. The Polynesian Race. London. Hocart, A. M. 1929. Lau Islands, Fiji. Bernice P. Bishop Museum, Bull. 62, Honolulu. Hooton, E. A. 1946. Up From the Ape. Macmillan Co., New York. Howells. W. W. 1933. Anthropometry and Blood Types in Fiji and the Solomon Islands. American Museum of Natural History. Anthropological Papers, Vol. 33, Pt. 4. Roth, G. K. 1953. The Fijian Way of Life. Oxford University Press, London. Simmon, R. T., J. J. Graydon, and G. Barnes 1945. The Medical Journal of Australia, May 26. Sullivan, L. R. 1922. A Contribution to Tongan Somotology. Bernice P. Bishop Museum, Vol. VIII, No. 4. Thomson, B. 1908. The Fijians: A Study of the Decay of Custom. Wm. Heinemann, London. PLATES [Illustration: PLATE 1. NEAR-AVERAGE BODY FEATURES Stature: 173.3 cm. Weight: 172.1 lbs. Arm length: 75.1 cm. Leg length: 82.2 cm. Shoulder breadth: 41 cm. Hip breadth: 29.1 cm. Shoulder-hip index: 71.0 Chest breadth: 28.8 cm. Chest depth: 22.8 cm. Thoracic index: 75.7 Sitting height: 86.3 cm. Sitting height-stature index: 50.0 Body build: Strongly mesomorphic] [Illustration: PLATE 2. NEAR-AVERAGE CRANIAL FEATURES Head length: 187.2 mm. Head breadth: 156.9 mm. Cephalic index: 83.9 Head height: 128.6 mm. Length-height index: 68.7 Length-breadth index: 81.1 Minimum frontal diameter: 109.8 mm. Fronto-parietal index: 70.0] [Illustration: PLATE 3. NEAR-AVERAGE FACIAL FEATURES Bizygomatic breadth: 146.7 mm. Cephalo-facial index: 93.2 Zygo-frontal index: 75.3 Bigonial breadth: 109.6 mm. Fronto-gonial index: 100.1 Zygo-gonial index: 74.7 Bicanine breadth: 39.8 Total facial height: 122.3 mm. Total facial index: 84.1 Upper facial height: 71.3 Upper facial index: 48.9 Nasal height: 53.1 Nasal breadth: 45.5 Nasal index: 85.6] [Illustration: PLATE 4. NEAR-AVERAGE FACE AND NOSE FEATURES _FACE_ Pronounced malars Moderately long face Wide gonia Moderate chin Moderate prognathism _NOSE_ Broad bridge Wide root Moderate length Thick tip Flaring nostrils Straight profile] [Illustration: PLATE 5. NEAR-AVERAGE LIP AND EAR FEATURES _LIPS_ Moderately thick Pronounced lip seam Moderate eversion _EARS_ Moderate size Small lobe Attached lobe Moderate protrusion] [Illustration: PLATE 6. NEAR-AVERAGE HAIR FEATURES Black color Frizzly form Pronounced quantity Coarse texture Intermediate length] [Illustration: PLATE 7. HAIR FORM VARIANTS CURLY HAIR WAVY HAIR] [Illustration: PLATE 8. PRONOUNCED BODY HAIR 20 per cent occurrence] [Illustration: PLATE 9. PRONOUNCED BEARD 26 per cent occurrence] [Illustration: PLATE 10. FACIAL VARIATIONS No prognathism High forehead Moderate browridges Moderate prognathism Low, receding forehead Pronounced browridges Pronounced prognathism Low, receding forehead Very pronounced browridges] [Illustration: PLATE 11. INTERIOR SUBJECT (MORE NEGROID) Shorter stature Narrower shoulders Deeper chest Darker skin Narrower head Broader nose Thicker lips] [Illustration: PLATE 12. "NEGROID" FIJIAN] [Illustration: PLATE 13. INTERIOR SUBJECT (MORE AUSTRALOID) Heavier beard and body hair Lower, more sloping forehead More compressed parietals More pronounced brow ridges More prognathic] [Illustration: PLATE 14. "AUSTRALOID" FIJIANS] [Illustration: PLATE 15. EASTERN SUBJECT (MORE POLYNESIAN) Lighter skin Less beard and body hair Wavy hair Wider head Higher, steeper forehead Less prognathic Higher, narrower nose Moderately thick lips] [Illustration: PLATE 16. "POLYNESIAN" FIJIANS] [Footnote 1: Hooton, 1946, pp. 735-763.] [Footnote 2: Derrick, 1946, pp. 5-6.] [Footnote 3: Ibid., pp. 7-8.] [Footnote 4: Population statistics from "Fiji Information," of 1954, issued by Public Relations Office, Suva, Fiji.] [Footnote 5: Hooton, 1946, p. 621.] [Footnote 6: Birdsell, 1949, p. 120.] [Footnote 7: Fornander, 1878.] [Footnote 8: Churchill, 1911.] [Footnote 9: Hocart, 1929, p. 236.] [Footnote 10: Howells, 1933, p. 335.] [Footnote 11: Roth, 1953, pp. 54, 55.] [Footnote 12: One pound deducted for dress (usually shorts only).] [Footnote 13: By subtracting sitting height from total stature.] [Footnote 14: Cranial measurements are not distorted by cradling practice or other causes of deformation.] [Footnote 15: Howells records skin color with the von Luschan scale. I have adjusted this scale to my own.] [Footnote 16: + means medium or moderate; ++ means pronounced; +++ means very pronounced.] [Footnote 17: Observation taken on the chest.] [Footnote 18: W. H. Sheldon, _The Variation of Human Physique_, Harper and Bros., 1940.] [Footnote 19: Birdsell, 1949, p. 120.] [Footnote 20: Hooton, 1946, p. 621.] [Footnote 21: Howells, 1933, p. 332.] [Footnote 22: Simmons _et al._, 1945, pp. 3-4] [Footnote 23: See pp. 1 and 4 of Introduction.] [Transcriber's Note: Figures incorrectly entered as zero have been calculated and inserted in {}.] End of Project Gutenberg's A Racial Study of the Fijians, by Norman E. Gabel	50,238	common-pile/project_gutenberg_filtered	39140	project gutenberg	project_gutenberg-dolma-0006.json.gz:579	https://www.gutenberg.org/ebooks/39140.txt.utf-8
B8xubOOzS50shIEB	Research Methods for the Social Sciences	32 F1: Chapters 1, 2, 3 & 4 Discussion Forum (The assigned chapters are embedded in this module using the LumenLearning LTI.) (Following the chapter links, there is a discussion forum.) F1: Chapters 1, 2, 3 & 4 Discussion Forum Within the first 3 days that the module begins, submit 1 original discussion question for each of the assigned chapters using this format: Chapter 1: {question}? Before you submit your question, make sure another student has not already submitted a similar question. Reply to each of the other questions submitted. To get my input on an issue – begin your post with: “Prof” –	135	common-pile/pressbooks_filtered	https://library.achievingthedream.org/herkimerresearchmethodsforsocialscience/chapter/f1-chapters-1-2-3-4-discussion-forum/	pressbooks	pressbooks-0000.json.gz:86130	https://library.achievingthedream.org/herkimerresearchmethodsforsocialscience/chapter/f1-chapters-1-2-3-4-discussion-forum/
9teGlOjn8wy8LkB2	18.6: Occurrence, Preparation, and Compounds of Hydrogen	18.6: Occurrence, Preparation, and Compounds of Hydrogen - - Last updated - Save as PDF Learning Objectives By the end of this section, you will be able to: - Describe the properties, preparation, and compounds of hydrogen Hydrogen is the most abundant element in the universe. The sun and other stars are composed largely of hydrogen. Astronomers estimate that 90% of the atoms in the universe are hydrogen atoms. Hydrogen is a component of more compounds than any other element. Water is the most abundant compound of hydrogen found on earth. Hydrogen is an important part of petroleum, many minerals, cellulose and starch, sugar, fats, oils, alcohols, acids, and thousands of other substances. At ordinary temperatures, hydrogen is a colorless, odorless, tasteless, and nonpoisonous gas consisting of the diatomic molecule H 2 . Hydrogen is composed of three isotopes, and unlike other elements, these isotopes have different names and chemical symbols: protium, 1 H, deuterium, 2 H(or “D”), and tritium 3 H(or “T”). In a naturally occurring sample of hydrogen, there is one atom of deuterium for every 7000 H atoms and one atom of radioactive tritium for every 10 18 H atoms. The chemical properties of the different isotopes are very similar because they have identical electron structures, but they differ in some physical properties because of their differing atomic masses. Elemental deuterium and tritium have lower vapor pressure than ordinary hydrogen. Consequently, when liquid hydrogen evaporates, the heavier isotopes are concentrated in the last portions to evaporate. Electrolysis of heavy water, D 2 O, yields deuterium. Most tritium originates from nuclear reactions. Preparation of Hydrogen Elemental hydrogen must be prepared from compounds by breaking chemical bonds. The most common methods of preparing hydrogen follow. From Steam and Carbon or Hydrocarbons Water is the cheapest and most abundant source of hydrogen. Passing steam over coke(an impure form of elemental carbon) at 1000 °C produces a mixture of carbon monoxide and hydrogen known as water gas: \[\ce{C(s) + H2O(g) ->[1000^{\circ} ~\text{C}] $\underset{\text{water gas}}{\ce{CO(g) + H_2(g)}}$ } \nonumber \] Water gas is as an industrial fuel. It is possible to produce additional hydrogen by mixing the water gas with steam in the presence of a catalyst to convert the CO to CO 2 . This reaction is the water gas shift reaction. It is also possible to prepare a mixture of hydrogen and carbon monoxide by passing hydrocarbons from natural gas or petroleum and steam over a nickel-based catalyst. Propane is an example of a hydrocarbon reactant: \[\ce{C3H8(g) + 3H2O(g) ->[900^{\circ} ~\text{C}][\text{catalyst}] 3CO(g) + 7H2(g) } \nonumber \] Electrolysis Hydrogen forms when direct current electricity passes through water containing an electrolyte such as H 2 SO 4 , as illustrated in Figure $\PageIndex{1}$. Bubbles of hydrogen form at the cathode, and oxygen evolves at the anode. The net reaction is: \[\ce{2 H2O(l) + electrical energy \longrightarrow 2 H2(g) + O2(g)} \nonumber \] Reaction of Metals with Acids This is the most convenient laboratory method of producing hydrogen. Metals with lower reduction potentials reduce the hydrogen ion in dilute acids to produce hydrogen gas and metal salts. For example, as shown in Figure $\PageIndex{2}$, iron in dilute hydrochloric acid produces hydrogen gas and iron(II) chloride: \[\ce{Fe(s) + 2 H3O^{+}(aq) + 2 Cl^{-}(aq) \longrightarrow Fe^{2+}(aq) + 2 Cl^{-}(aq) + H_2(g) + 2 H2O(l)} \nonumber \] Reaction of Ionic Metal Hydrides with Water It is possible to produce hydrogen from the reaction of hydrides of the active metals, which contain the very strongly basic H − anion, with water: \[\ce{CaH_2(s) + 2 H2O(l) \longrightarrow Ca^{2+}(aq) + 2 OH^{-}(aq) + 2 H_2(g)} \nonumber \] Metal hydrides are expensive but convenient sources of hydrogen, especially where space and weight are important factors. They are important in the inflation of life jackets, life rafts, and military balloons. Reactions Under normal conditions, hydrogen is relatively inactive chemically, but when heated, it enters into many chemical reactions. Two thirds of the world’s hydrogen production is devoted to the manufacture of ammonia, which is a fertilizer and used in the manufacture of nitric acid. Large quantities of hydrogen are also important in the process of hydrogenation , discussed in the chapter on organic chemistry. It is possible to use hydrogen as a nonpolluting fuel. The reaction of hydrogen with oxygen is a very exothermic reaction, releasing 286 kJ of energy per mole of water formed. Hydrogen burns without explosion under controlled conditions. The oxygen-hydrogen torch, because of the high heat of combustion of hydrogen, can achieve temperatures up to 2800 °C. The hot flame of this torch is useful in cutting thick sheets of many metals. Liquid hydrogen is also an important rocket fuel (Figure $\PageIndex{3}$). An uncombined hydrogen atom consists of a nucleus and one valence electron in the 1 s orbital. The n = 1 valence shell has a capacity for two electrons, and hydrogen can rightfully occupy two locations in the periodic table. It is possible to consider hydrogen a group 1 element because hydrogen can lose an electron to form the cation, H + . It is also possible to consider hydrogen to be a group 17 element because it needs only one electron to fill its valence orbital to form a hydride ion, H − , or it can share an electron to form a single, covalent bond. In reality, hydrogen is a unique element that almost deserves its own location in the periodic table. Reactions with Elements When heated, hydrogen reacts with the metals of group 1 and with Ca, Sr, and Ba(the more active metals in group 2). The compounds formed are crystalline, ionic hydrides that contain the hydride anion, H − , a strong reducing agent and a strong base, which reacts vigorously with water and other acids to form hydrogen gas. The reactions of hydrogen with nonmetals generally produce acidic hydrogen compounds with hydrogen in the 1+ oxidation state. The reactions become more exothermic and vigorous as the electronegativity of the nonmetal increases. Hydrogen reacts with nitrogen and sulfur only when heated, but it reacts explosively with fluorine(forming HF) and, under some conditions, with chlorine(forming HCl). A mixture of hydrogen and oxygen explodes if ignited. Because of the explosive nature of the reaction, it is necessary to exercise caution when handling hydrogen(or any other combustible gas) to avoid the formation of an explosive mixture in a confined space. Although most hydrides of the nonmetals are acidic, ammonia and phosphine(PH 3 ) are very, very weak acids and generally function as bases. There is a summary of these reactions of hydrogen with the elements in Table $\PageIndex{1}$. \| General Equation \| Comments \| \|---\|---\| \| $\ce{MH} \text { or } \ce{MH2 \longrightarrow MOH} \text { or } \ce{M(OH)2 + H 2}$ \| ionic hydrides with group 1 and Ca, Sr, and Ba \| \| $\ce{H2 + C \longrightarrow(no reaction)}$ \| \| \| $\ce{3 H2 + N2 \longrightarrow 2 NH3}$ \| requires high pressure and temperature; low yield \| \| $\ce{2 H2 + O2 \longrightarrow 2 H2O}$ \| exothermic and potentially explosive \| \| \[\ce{H2 + S \longrightarrow H2S}\) \| requires heating; low yield \| \| $\ce{H2+ X2 \longrightarrow 2HX}$ \| X = F, Cl, Br, and I; explosive with F 2 ; low yield with I 2 \| Reaction with Compounds Hydrogen reduces the heated oxides of many metals, with the formation of the metal and water vapor. For example, passing hydrogen over heated CuO forms copper and water. Hydrogen may also reduce the metal ions in some metal oxides to lower oxidation states: \[\ce{H2(g) + MnO2(s) ->[\Delta] MnO(s) + H2O(g)} \nonumber \] Hydrogen Compounds Other than the noble gases, each of the nonmetals forms compounds with hydrogen. For brevity, we will discuss only a few hydrogen compounds of the nonmetals here. Nitrogen Hydrogen Compounds Ammonia, NH 3 , forms naturally when any nitrogen-containing organic material decomposes in the absence of air. The laboratory preparation of ammonia is by the reaction of an ammonium salt with a strong base such as sodium hydroxide. The acid-base reaction with the weakly acidic ammonium ion gives ammonia, illustrated in Figure $\PageIndex{4}$. Ammonia also forms when ionic nitrides react with water. The nitride ion is a much stronger base than the hydroxide ion: \[\ce{Mg3N2(s) + 6 H2O(l) \longrightarrow 3 Mg(OH)2(s) + 2 NH3(g)} \nonumber \] The commercial production of ammonia is by the direct combination of the elements in the Haber process : \[\ce{N2(g) + 3 H2(g) ->[\text{catalyst}] 2 NH3(g)} \quad \quad \quad \quad \Delta H^{\circ}=-92 ~\text{kJ} \nonumber \] Ammonia is a colorless gas with a sharp, pungent odor. Smelling salts utilize this powerful odor. Gaseous ammonia readily liquefies to give a colorless liquid that boils at −33 °C. Due to intermolecular hydrogen bonding, the enthalpy of vaporization of liquid ammonia is higher than that of any other liquid except water, so ammonia is useful as a refrigerant. Ammonia is quite soluble in water(658 L at STP dissolves in 1 L H 2 O). The chemical properties of ammonia are as follows: - Ammonia acts as a Brønsted base, as discussed in the chapter on acid-base chemistry. The ammonium ion is similar in size to the potassium ion; compounds of the two ions exhibit many similarities in their structures and solubilities. - Ammonia can display acidic behavior, although it is a much weaker acid than water. Like other acids, ammonia reacts with metals, although it is so weak that high temperatures are necessary. Hydrogen and(depending on the stoichiometry) amides(salts of $\ce{NH2^{-}}$), imides(salts of NH 2 − ), or nitrides(salts of N 3− ) form. - The nitrogen atom in ammonia has its lowest possible oxidation state(3−) and thus is not susceptible to reduction. However, it can be oxidized. Ammonia burns in air, giving NO and water. Hot ammonia and the ammonium ion are active reducing agents. Of particular interest are the oxidations of ammonium ion by nitrite ion, to yield pure nitrogen and by nitrate ion to yield nitrous oxide, N 2 O. - There are a number of compounds that we can consider derivatives of ammonia through the replacement of one or more hydrogen atoms with some other atom or group of atoms. Inorganic derivations include chloramine, NH 2 Cl, and hydrazine, N 2 H 4 : Chloramine, NH 2 Cl, results from the reaction of sodium hypochlorite, NaOCl, with ammonia in basic solution. In the presence of a large excess of ammonia at low temperature, the chloramine reacts further to produce hydrazine, N 2 H 4 : \[\begin{align} \ce{NH3(aq) + OCl^{-}(aq) & -> NH2Cl(aq) + OH^{-}(aq)} \\[4pt][4pt] \ce{NH2Cl(aq) + NH3(aq) + OH^{-}(aq) &-> N2H4(aq) + Cl^{-}(aq) + H2O(l)} \end{align} \] Anhydrous hydrazine is relatively stable in spite of its positive free energy of formation: \[\ce{N2(g) + 2 H2(g) \longrightarrow N2H4(l)} \quad \quad \Delta G_{ f }^{\circ}=149.2 kJ mol^{-1} \nonumber \] Hydrazine is a fuming, colorless liquid that has some physical properties remarkably similar to those of H 2 O(it melts at 2 °C, boils at 113.5 °C, and has a density at 25 °C of 1.00 g/mL). It burns rapidly and completely in air with substantial evolution of heat: \[\ce{N2H4(l) + O2(g) \longrightarrow N2(g) +2 H2O(l)} \quad \quad \Delta H^{\circ}=-621.5 kJ mol^{-1} \nonumber \] Like ammonia, hydrazine is both a Brønsted base and a Lewis base, although it is weaker than ammonia. It reacts with strong acids and forms two series of salts that contain the and ions, respectively. Some rockets use hydrazine as a fuel. Phosphorus Hydrogen Compounds The most important hydride of phosphorus is phosphine, PH 3 , a gaseous analog of ammonia in terms of both formula and structure. Unlike ammonia, it is not possible to form phosphine by direct union of the elements. There are two methods for the preparation of phosphine. One method is by the action of an acid on an ionic phosphide. The other method is the disproportionation of white phosphorus with hot concentrated base to produce phosphine and the hydrogen phosphite ion: \[\begin{align} \ce{AlP(s) + 3 H3O^{+}(aq) \longrightarrow PH3(g) + Al^{3+}(aq) + 3 H2O(l)} \\[4pt][4pt] \ce{P4(s) + 4 OH^{-}(aq) + 2 H2O(l) \longrightarrow 2 HPO3^{2-}(aq) + 2 PH3(g)} \end{align} \] Phosphine is a colorless, very poisonous gas, which has an odor like that of decaying fish. Heat easily decomposes phosphine ($\ce{4 PH3 -> P4 + 6H2}$) and the compound burns in air. The major uses of phosphine are as a fumigant for grains and in semiconductor processing. Like ammonia, gaseous phosphine unites with gaseous hydrogen halides, forming phosphonium compounds like PH 4 Cl and PH 4 I. Phosphine is a much weaker base than ammonia; therefore, these compounds decompose in water, and the insoluble PH 3 escapes from solution. Sulfur Hydrogen Compounds Hydrogen sulfide, H 2 S, is a colorless gas that is responsible for the offensive odor of rotten eggs and of many hot springs. Hydrogen sulfide is as toxic as hydrogen cyanide; therefore, it is necessary to exercise great care in handling it. Hydrogen sulfide is particularly deceptive because it paralyzes the olfactory nerves; after a short exposure, one does not smell it. The production of hydrogen sulfide by the direct reaction of the elements(H 2 + S) is unsatisfactory because the yield is low. A more effective preparation method is the reaction of a metal sulfide with a dilute acid. For example: \[\ce{FeS(s) + 2 H3O^{+}(aq) \longrightarrow Fe^{2+}(aq) + H_2 S(g) + 2 H2O(l)} \nonumber \] It is easy to oxidize the sulfur in metal sulfides and in hydrogen sulfide, making metal sulfides and H 2 S good reducing agents. In acidic solutions, hydrogen sulfide reduces Fe 3 + to Fe 2 + , to Mn 2 + , to Cr 3 + , and HNO 3 to NO 2 . The sulfur in H 2 S usually oxidizes to elemental sulfur, unless a large excess of the oxidizing agent is present. In which case, the sulfide may oxidize to or(or to SO 2 or SO 3 in the absence of water): \[\ce{2 H_2 S(g) + O_2(g) \longrightarrow 2 S(s) + 2 H2O(l)} \nonumber \] This oxidation process leads to the removal of the hydrogen sulfide found in many sources of natural gas. The deposits of sulfur in volcanic regions may be the result of the oxidation of H 2 S present in volcanic gases. Hydrogen sulfide is a weak diprotic acid that dissolves in water to form hydrosulfuric acid. The acid ionizes in two stages, yielding hydrogen sulfide ions, HS − , in the first stage and sulfide ions, S 2− , in the second. Since hydrogen sulfide is a weak acid, aqueous solutions of soluble sulfides and hydrogen sulfides are basic: \[\begin{align} \ce{S^{2-}(aq) + H2O(l) &\rightleftharpoons HS^{-}(aq) + OH^{-}(aq)} \\[4pt][4pt] \ce{HS^{-}(aq) + H2O(l) &\rightleftharpoons H2S(g) + OH^{-}(aq)} \end{align} \] Halogen Hydrogen Compounds Binary compounds containing only hydrogen and a halogen are hydrogen halides . At room temperature, the pure hydrogen halides HF, HCl, HBr, and HI are gases. In general, it is possible to prepare the halides by the general techniques used to prepare other acids. Fluorine, chlorine, and bromine react directly with hydrogen to form the respective hydrogen halide. This is a commercially important reaction for preparing hydrogen chloride and hydrogen bromide. The acid-base reaction between a nonvolatile strong acid and a metal halide will yield a hydrogen halide. The escape of the gaseous hydrogen halide drives the reaction to completion. For example, the usual method of preparing hydrogen fluoride is by heating a mixture of calcium fluoride, CaF 2 , and concentrated sulfuric acid: \[\ce{CaF2(s) + H2SO4(aq) \longrightarrow CaSO4(s) + 2 HF(g)} \nonumber \] Gaseous hydrogen fluoride is also a by-product in the preparation of phosphate fertilizers by the reaction of fluoroapatite, Ca 5 (PO 4 ) 3 F, with sulfuric acid. The reaction of concentrated sulfuric acid with a chloride salt produces hydrogen chloride both commercially and in the laboratory. In most cases, sodium chloride is the chloride of choice because it is the least expensive chloride. Hydrogen bromide and hydrogen iodide cannot be prepared using sulfuric acid because this acid is an oxidizing agent capable of oxidizing both bromide and iodide. However, it is possible to prepare both hydrogen bromide and hydrogen iodide using an acid such as phosphoric acid because it is a weaker oxidizing agent. For example: \[\ce{H3PO4(l) + Br^{-}(aq) \longrightarrow HBr(g) + H2PO4^{-}(aq)} \nonumber \] All of the hydrogen halides are very soluble in water, forming hydrohalic acids. With the exception of hydrogen fluoride, which has a strong hydrogen-fluoride bond, they are strong acids. Reactions of hydrohalic acids with metals, metal hydroxides, oxides, or carbonates produce salts of the halides. Most chloride salts are soluble in water. AgCl, PbCl 2 , and Hg 2 Cl 2 are the commonly encountered exceptions. The halide ions give the substances the properties associated with X − ( aq ). The heavier halide ions(Cl − , Br − , and I − ) can act as reducing agents, and the lighter halogens or other oxidizing agents will oxidize them: \[\begin{align} \ce{Cl_2(aq) + 2 e^{-} &<=> 2 Cl^{-}(aq)} & E^{\circ}=1.36 V \\[4pt][4pt] \ce{Br2(aq) + 2 e^{-} &<=> 2 Br^{-}(aq)} & E^{\circ}=1.09 V \\[4pt][4pt] \ce{I2(aq) + 2 e^{-} &<=> 2 I^{-}(aq)} & E^{\circ}=0.54 V \end{align} \] For example, bromine oxidizes iodine: \[\ce{Br2(aq) + 2 HI(aq) \longrightarrow 2 HBr(aq) + I2(aq)} \quad \quad E^{\circ}=0.55 V \nonumber \] Hydrofluoric acid is unique in its reactions with sand(silicon dioxide) and with glass, which is a mixture of silicates: \[\begin{align} \ce{SiO2(s) + 4 HF(aq) &\longrightarrow SiF4(g) + 2 H2O(l)} \\[4pt][4pt] \ce{CaSiO3(s) + 6 HF(aq) &\longrightarrow CaF2(s) + SiF4(g) + 3 H2O}(l) \end{align} \nonumber \] The volatile silicon tetrafluoride escapes from these reactions. Because hydrogen fluoride attacks glass, it can frost or etch glass and is used to etch markings on thermometers, burets, and other glassware. The largest use for hydrogen fluoride is in production of hydrochlorofluorocarbons for refrigerants, in plastics, and in propellants. The second largest use is in the manufacture of cryolite, Na 3 AlF 6 , which is important in the production of aluminum. The acid is also important in the production of other inorganic fluorides(such as BF 3 ), which serve as catalysts in the industrial synthesis of certain organic compounds. Hydrochloric acid is relatively inexpensive. It is an important and versatile acid in industry and is important for the manufacture of metal chlorides, dyes, glue, glucose, and various other chemicals. A considerable amount is also important for the activation of oil wells and as pickle liquor—an acid used to remove oxide coating from iron or steel that is to be galvanized, tinned, or enameled. The amounts of hydrobromic acid and hydroiodic acid used commercially are insignificant by comparison.	4,027	common-pile/libretexts_filtered	https://chem.libretexts.org/Bookshelves/General_Chemistry/Chemistry_-_Atoms_First_2e_(OpenStax)/18%3A_Representative_Metals_Metalloids_and_Nonmetals/18.06%3A_Occurrence_Preparation_and_Compounds_of_Hydrogen	libretexts	libretexts-0000.json.gz:3771	https://chem.libretexts.org/Bookshelves/General_Chemistry/Chemistry_-_Atoms_First_2e_(OpenStax)/18%3A_Representative_Metals_Metalloids_and_Nonmetals/18.06%3A_Occurrence_Preparation_and_Compounds_of_Hydrogen
RQ8qBT-7wINCtirI	2.8: Units Raised to a Power	2.8: Units Raised to a Power - - Last updated - Save as PDF Learning Objectives - To convert a value reported in one unit raised to a power of 10, to a corresponding value in a different unit raised to the same power of 10, using conversion factors. Conversion factors for area and volume can also be produced by the dimensional analysis method. Just remember that if a quantity is raised to a power of 10, both the number and the unit must be raised to the same power of 10. For example, to convert $1500 \: \text{cm}^2$ to $\text{m}^2$, we need to start with the relationship between centimeter and meter. We know that 1 cm = 10 -2 m or 100 cm =1 m, but since we are given the quantity in 1500 cm 2 , then we have to use the relationship: \[1\, cm^2 = (10^{-2}\, m)^2 = 10^{-4}\, m^2 \nonumber \] CONCEPT MAP CALCULATION \[1500 \: \cancel{\text{cm}}^2 \times \left( \dfrac{10^{-2} \: \text{m}}{1 \: \cancel{\text{cm}}} \right)^2 = 0.15 \: \text{m}^2 \nonumber \] or \[1500 \: \cancel{\text{cm}}^2 \times \left( \dfrac{1 \: \text{m}}{100 \: \cancel{\text{cm}}} \right)^2 = 0.15 \: \text{m}^2 \nonumber \] or \[1500 \: \cancel{\text{cm}}^2 \times \dfrac{1 \: \text{m}^2}{10,000 \: \cancel{\text{cm}^2}} = 0.15 \: \text{m}^2 \nonumber \] Example $\PageIndex{1}$: Volume of a Sphere What is the volume of a sphere (radius 4.30 inches) in cubic cm (cm 3 )? Solution \| Steps for Problem Solving \| What is the volume of a sphere (radius 4.30 inches) in cubic cm (cm 3 )? \| \|---\|---\| \| Identify the "given” information and what the problem is asking you to "find." \| Given: radius = 4.30 in Find: cm 3 (volume) \| \| Determine other known quantities. \| Volume of a sphere: V = $\dfrac{4}{3} \times \pi \times r^3 $ = $\dfrac{4}{3} \times 3.1416 \times (4.3\underline{0}in)^3 $ = $33\underline{3}.04 in^3$ \| \| Prepare a concept map. \| \| \| Calculate. \| $33\underline{3}.04 \cancel{in^3} \left(\dfrac{2.54cm}{1 \cancel{in}}\right)^3 = 5.46 \times10^3 cm^3$ \| \| Think about your result. \| A centimeter is a smaller unit than an inch, so the answer in cubic centimeters is larger than the given value in cubic inches. \| Exercise $\PageIndex{1}$ Lake Tahoe has a surface area of 191 square miles. What is the area in square km (km 2 )? - Answer - 495 km 2	504	common-pile/libretexts_filtered	https://chem.libretexts.org/Courses/UWMilwaukee/CHE_125%3A_GOB_Introductory_Chemistry/02%3A_Measurements_and_Density/2.08%3A_Units_Raised_to_a_Power	libretexts	libretexts-0000.json.gz:4902	https://chem.libretexts.org/Courses/UWMilwaukee/CHE_125%3A_GOB_Introductory_Chemistry/02%3A_Measurements_and_Density/2.08%3A_Units_Raised_to_a_Power
hO7Ko_fzLV3fUgcL	7.3: Compostion and Structure of Planets	7.3: Compostion and Structure of Planets By the end of this section, you will be able to: - Describe the characteristics of the giant planets, terrestrial planets, and small bodies in the solar system - Explain what influences the temperature of a planet’s surface - Explain why there is geological activity on some planets and not on others The fact that there are two distinct kinds of planets—the rocky terrestrial planets and the gas-rich jovian planets—leads us to believe that they formed under different conditions. Certainly their compositions are dominated by different elements. Let us look at each type in more detail. The Giant Planets The two largest planets, Jupiter and Saturn , have nearly the same chemical makeup as the Sun; they are composed primarily of the two elements hydrogen and helium, with 75% of their mass being hydrogen and 25% helium. On Earth, both hydrogen and helium are gases, so Jupiter and Saturn are sometimes called gas planets. But, this name is misleading. Jupiter and Saturn are so large that the gas is compressed in their interior until the hydrogen becomes a liquid. Because the bulk of both planets consists of compressed, liquefied hydrogen, we should really call them liquid planets. Under the force of gravity, the heavier elements sink toward the inner parts of a liquid or gaseous planet. Both Jupiter and Saturn, therefore, have cores composed of heavier rock, metal, and ice, but we cannot see these regions directly. In fact, when we look down from above, all we see is the atmosphere with its swirling clouds (Figure 7.11). We must infer the existence of the denser core inside these planets from studies of each planet’s gravity. Uranus and Neptune are much smaller than Jupiter and Saturn, but each also has a core of rock, metal, and ice. Uranus and Neptune were less efficient at attracting hydrogen and helium gas, so they have much smaller atmospheres in proportion to their cores. Chemically, each giant planet is dominated by hydrogen and its many compounds. Nearly all the oxygen present is combined chemically with hydrogen to form water (H 2 O). Chemists call such a hydrogen-dominated composition reduced . Throughout the outer solar system, we find abundant water (mostly in the form of ice) and reducing chemistry. The Terrestrial Planets The terrestrial planets are quite different from the giants. In addition to being much smaller, they are composed primarily of rocks and metals. These, in turn, are made of elements that are less common in the universe as a whole. The most abundant rocks, called silicates, are made of silicon and oxygen, and the most common metal is iron. We can tell from their densities (see Table 7.2) that Mercury has the greatest proportion of metals (which are denser) and the Moon has the lowest. Earth , Venus , and Mars all have roughly similar bulk compositions: about one third of their mass consists of iron-nickel or iron-sulfur combinations; two thirds is made of silicates. Because these planets are largely composed of oxygen compounds (such as the silicate minerals of their crusts), their chemistry is said to be oxidized . When we look at the internal structure of each of the terrestrial planets, we find that the densest metals are in a central core, with the lighter silicates near the surface. If these planets were liquid, like the giant planets, we could understand this effect as the result the sinking of heavier elements due to the pull of gravity. This leads us to conclude that, although the terrestrial planets are solid today, at one time they must have been hot enough to melt. Differentiation is the process by which gravity helps separate a planet’s interior into layers of different compositions and densities. The heavier metals sink to form a core, while the lightest minerals float to the surface to form a crust. Later, when the planet cools, this layered structure is preserved. In order for a rocky planet to differentiate, it must be heated to the melting point of rocks, which is typically more than 1300 K. Moons, Asteroids, and Comets Chemically and structurally, Earth’s Moon is like the terrestrial planets, but most moons are in the outer solar system, and they have compositions similar to the cores of the giant planets around which they orbit. The three largest moons—Ganymede and Callisto in the jovian system, and Titan in the saturnian system—are composed half of frozen water, and half of rocks and metals. Most of these moons differentiated during formation, and today they have cores of rock and metal, with upper layers and crusts of very cold and—thus very hard—ice (Figure 7.12). Most of the asteroids and comets, as well as the smallest moons, were probably never heated to the melting point. However, some of the largest asteroids, such as Vesta , appear to be differentiated; others are fragments from differentiated bodies. Many of the smaller objects seem to be fragments or rubble piles that are the result of collisions. Because most asteroids and comets retain their original composition, they represent relatively unmodified material dating back to the time of the formation of the solar system. In a sense, they act as chemical fossils, helping us to learn about a time long ago whose traces have been erased on larger worlds. Temperatures: Going to Extremes Generally speaking, the farther a planet or moon is from the Sun, the cooler its surface. The planets are heated by the radiant energy of the Sun, which gets weaker with the square of the distance. You know how rapidly the heating effect of a fireplace or an outdoor radiant heater diminishes as you walk away from it; the same effect applies to the Sun. Mercury , the closest planet to the Sun, has a blistering surface temperature that ranges from 280–430 °C on its sunlit side, whereas the surface temperature on Pluto is only about –220 °C, colder than liquid air. Mathematically, the temperatures decrease approximately in proportion to the square root of the distance from the Sun. Pluto is about 30 AU at its closest to the Sun (or 100 times the distance of Mercury) and about 49 AU at its farthest from the Sun. Thus, Pluto’s temperature is less than that of Mercury by the square root of 100, or a factor of 10: from 500 K to 50 K. In addition to its distance from the Sun, the surface temperature of a planet can be influenced strongly by its atmosphere. Without our atmospheric insulation (the greenhouse effect, which keeps the heat in), the oceans of Earth would be permanently frozen. Conversely, if Mars once had a larger atmosphere in the past, it could have supported a more temperate climate than it has today. Venus is an even more extreme example, where its thick atmosphere of carbon dioxide acts as insulation, reducing the escape of heat built up at the surface, resulting in temperatures greater than those on Mercury. Today, Earth is the only planet where surface temperatures generally lie between the freezing and boiling points of water. As far as we know, Earth is the only planet to support life. In the classic film The Wizard of Oz , Dorothy, the heroine, concludes after her many adventures in “alien” environments that “there’s no place like home.” The same can be said of the other worlds in our solar system. There are many fascinating places, large and small, that we might like to visit, but humans could not survive on any without a great deal of artificial assistance. Mars, on the other hand, has temperatures generally below freezing, with air (also mostly carbon dioxide) so thin that it resembles that found at an altitude of 30 kilometers (100,000 feet) in Earth’s atmosphere. And the red planet is so dry that it has not had any rain for billions of years. The outer layers of the jovian planets are neither warm enough nor solid enough for human habitation. Any bases we build in the systems of the giant planets may well have to be in space or one of their moons—none of which is particularly hospitable to a luxury hotel with a swimming pool and palm trees. Perhaps we will find warmer havens deep inside the clouds of Jupiter or in the ocean under the frozen ice of its moon Europa. All of this suggests that we had better take good care of Earth because it is the only site where life as we know it could survive. Recent human activity may be reducing the habitability of our planet by adding pollutants to the atmosphere, especially the potent greenhouse gas carbon dioxide. Human civilization is changing our planet dramatically, and these changes are not necessarily for the better. In a solar system that seems unready to receive us, making Earth less hospitable to life may be a grave mistake. Geological Activity The crusts of all of the terrestrial planets, as well as of the larger moons, and Pluto, have been modified over their histories by both internal and external forces. Externally, each has been battered by a slow rain of projectiles from space, leaving their surfaces pockmarked by impact craters of all sizes (see Figure 7.4). We have good evidence that this bombardment was far greater in the early history of the solar system, but it certainly continues to this day, even if at a lower rate. The collision of more than 20 large pieces of Comet Shoemaker–Levy 9 with Jupiter in the summer of 1994 (see Figure 7.13) is one dramatic example of this process. Figure 7.14 shows the aftermath of these collisions, when debris clouds larger than Earth could be seen in Jupiter ’s atmosphere. During the time all the planets have been subject to such impacts, internal forces on the terrestrial planets have buckled and twisted their crusts, built up mountain ranges, erupted as volcanoes, and generally reshaped the surfaces in what we call geological activity. (The prefix geo means “Earth,” so this is a bit of an “Earth-chauvinist” term, but it is so widely used that we bow to tradition.) Among the terrestrial planets, Earth and Venus have experienced the most geological activity over their histories, although some of the moons in the outer solar system are also surprisingly active. In contrast, our own Moon is a dead world where geological activity ceased billions of years ago. Geological activity on a planet is the result of a hot interior. The forces of volcanism and mountain building are driven by heat escaping from the interiors of planets. As we will see, each of the planets was heated at the time of its birth, and this primordial heat initially powered extensive volcanic activity, even on our Moon. But, small objects such as the Moon soon cooled off. The larger the planet or moon, the longer it retains its internal heat, and therefore the more we expect to see surface evidence of continuing geological activity. The effect is similar to our own experience with a hot baked potato: the larger the potato, the more slowly it cools. If we want a potato to cool quickly, we cut it into small pieces. For the most part, the history of volcanic activity on the terrestrial planets conforms to the predictions of this simple theory. The Moon, the smallest of these objects, is a geologically dead world. Although we know less about Mercury, it seems likely that this planet, too, ceased most volcanic activity about the same time the Moon did. Mars represents an intermediate case. It has been much more active than the Moon, but less so than Earth. Earth and Venus, the largest terrestrial planets, still have molten interiors even today, some 4.5 billion years after their birth.	2,544	common-pile/libretexts_filtered	https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/Astronomy_2e_(OpenStax)/07%3A_Other_Worlds_-_An_Introduction_to_the_Solar_System/7.03%3A_Compostion_and_Structure_of_Planets	libretexts	libretexts-0000.json.gz:2827	https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/Astronomy_2e_(OpenStax)/07%3A_Other_Worlds_-_An_Introduction_to_the_Solar_System/7.03%3A_Compostion_and_Structure_of_Planets
Su1eot9BGzeTHvV5	Introduction to Criminology: An Equity Lens	6.4 Subcultural Theories of Crime Culture consists of tangible things that you can touch as well as ideas, attitudes, and beliefs. The style of our buses in the United States compared to those in other countries becomes part of our culture, just as our norms about how close you should stand to other passengers on the bus are part of our culture (Conerly et al., 2024). Societies have a mainstream culture consisting of the conventional norms and status quo. Oftentimes, subcultures will also be present in a society. Subcultures are groups that share a specific identity that differs from the mainstream majority, even though they exist within the larger society (Conerly et al., 2024). Subcultural theories of crime view crime as a result of either conformity to a subculture or rebellion against the mainstream culture. First, take a look at the context in which many of these theories developed. Following the housing boom and baby boom of the 1950s, the United States moved into an era of revolution in the 1960s and ’70s. Many social norms were challenged, ranging from rebellions against mainstream music and clothing to larger demands for change in civil rights for marginalized groups. Inequalities were brought out into the open and sociologists took notice. Merton’s strain theory, as we discussed in Chapter 5, made a lot of sense to some criminologists in this setting, and they began to see how well it fit with certain groups or situations. Scholars within The Chicago School expanded the notions of strain and anomie, building upon Merton’s work, to explain how this might apply to everyday life for a broader population. Many subcultural theories combine elements of structural theories with components of learning and interactionist theories to explain how subcultures develop and may facilitate criminal offending. In this chapter, we will discuss theories on the subculture of violence, cultural deviance, and the code of the streets, as well as criminological explanations of gang formation, including status frustration theory and differential opportunity theory. Deviating From the Dominant Culture The dominant culture in a society is promoted as the only acceptable way to live, behave, and believe, whether or not smaller groups who are not represented in this dominant majority agree. The norms and values of the dominant culture are even considered “right” when they contradict what is actually preferred by smaller, less powerful groups. These other groups often develop their own subcultures, which may not align with the dominant culture and are considered deviant. Among the sociologists in The Chicago School, the subcultures they witnessed in urban Chicago were the subject of much of their research. Most of the (especially early) theorists were part of the dominant culture in the United States. However, it is in this area that Black scholars were finally able to gain prominence by explaining what the experience is like from inside a subculture, rather than looking in from the outside as many white scholars did. For decades, W.E.B. Du Bois, a Black sociologist working in the early 1900s, was excluded from discussions on criminological and sociological theories because of his race. Many of his assertions were later claimed by or credited to white scholars who made similar arguments. He also struggled to get published in academic journals and major periodicals because they did not accept work from Black scholars. His work did not become truly appreciated in the mainstream until nearly 100 years after it was presented. Du Bois studied crime in Black communities long before those in The Chicago School began their work. Du Bois is noted for his theories on racial injustice, the social construction of crime, and the criminalization of Blackness. He argued that Black communities experienced racist social and economic exclusion, creating an area where crime was one of the few options for survival. Later, when Shaw and McKay published their social disorganization theory in the 1940s, they were given credit for discovering much of what Du Bois had already described. His work still gets conflated with theirs, despite the fact that Shaw and McKay looked at social control within neighborhoods, whereas Du Bois recognized the societal systems that caused the phenomena that led to social disorganization in the first place. He argued that resolving issues of racial exclusion, oppression, and economic injustice would drastically reduce criminal behavior. For some criminologists,these mechanisms of marginalization explain the development of subcultures that embrace or facilitate criminality. The Subculture of Violence and Cultural Deviance Theory Marvin Wolfgang and Franco Ferracuti (1967) developed the subculture of violence theory, which states that certain norms and values in working class communities can explain violent crime. According to these researchers, violence is an expected and normalized response to conflict in these communities. It is not viewed negatively, but rather as just the way things are done. For this reason, Wolfgang and Ferracuti claimed people in this subculture are always prepared for interactions to turn violent. There is no guilt associated with the violence, according to Wolfgang and Ferracuti, and it is typically encouraged and valued. However, reacting to situations with violence is a learned behavior, which means it can be unlearned. Walter Miller also believed that the entire lower class in America had its own subculture, with values and norms that differed from those of mainstream America. Miller’s (1958) cultural deviance theory claims that lower-class parents socialize their children into six focal concerns that run counter to mainstream culture, including trouble, toughness, smartness, excitement, fate, and autonomy (figure 6.17). According to Miller, adhering to these values is simply an act of conformity to the subculture held by the lower class. However, such adherence leads to delinquency and crime. \| Focal Concern (Value) \| Meaning \| \|---\|---\| \| Trouble \| The value of being able to get yourself out of your own personal problems; can actually elevate your social status within the subculture \| \| Toughness \| The value of strength and ability and willingness to fight, especially to uphold your social reputation \| \| Smartness \| The value of being able to outsmart or con others to achieve material gains (street smarts) \| \| Excitement \| The value of thrill-seeking, especially as a way to escape the mundane existence of being in the lower class \| \| Fate \| The belief in destiny and luck; can disregard accountability and responsibility for one’s actions especially as many in the lower class do not believe they will live long lives \| \| Autonomy \| The value of independence and not being controlled by anyone \| The Code of the Streets “It’s easy to be judgmental about crime when you live in a world wealthy enough to be removed from it. But the hood taught me that everyone has different notions of right and wrong, different definitions of what constitutes crime, and what level of crime they’re willing to participate in.” Trevor Noah, South African comedian, political commentator, and former host of The Daily Show In 1999, Elijah Anderson, a Black sociologist, studied Black neighborhoods in Philadelphia building on the work of W. E. B. Du Bois. In his book, The Code of the Street: Decency, Violence, and the Moral Life of the Inner City, he named and detailed aspects of street culture that he said stresses a hyperinflated notion of manhood centering on the idea of respect. According to Anderson, respect was defined as being treated right or being granted deserved deference. In this street culture or code of the street, a man’s sense of worth is determined by the respect he can command in public. Anderson found that since these young Black men lived in a subculture that was violent due to lack of jobs and basic public services, stigma related to race, and hopelessness, an individual could not back down from any threat, no matter how serious. Also, since economic and social circumstances limited opportunities for legitimate success, many of these men tried to find alternative ways of making money to provide for their families (similar to the innovators in Merton’s strain theory). As Trevor Noah suggested, the environment can alter what behavior is deemed acceptable. In his research, Anderson identified two types of Black American families who resided in the inner-city: decent families and street families. Decent families embraced middle-class and mainstream norms, while street families fully embraced “street” culture, which was characterized by violence, aggression, and lawlessness. He claimed that standing against “middle-class decency” was ingrained in the code of the streets. The code, or rules and norms of the inner city, helped individuals achieve success on the streets but harmed their ability to achieve socially accepted (and legal) success (figure 6.18). This made for a difficult transition for individuals who wished to leave “the life” but lacked the skills to achieve success in a society where one does not benefit from being street-smart (figure 6.19). Activity: Exploring Anderson’s Code of the Street - How is the code of the streets at odds with mainstream/dominant culture? - How do concepts discussed in the video relate to both subcultural theories and strain theories? In other words, how would each theory explain the significance of these concepts/factors? - Based on examples provided in the video, what might contribute to racial tensions between Black community members and law enforcement in urban settings? - How do you see girls and women represented in the code of the streets? - Do you think that the values associated with lower-class and Black communities, according to subcultural theories, accurately reflect these communities? Do you think these communities deny middle-class/mainstream social norms? - What are the ethical issues with researchers from mainstream or ethnocentric (white) cultures studying marginalized populations? Gangs as Delinquent Subcultures Frederic Thrasher, another white sociologist from the famed Chicago School, conducted a study in 1927 about gangs. He believed that the social conditions in the United States at the end of the 19th century had encouraged the development of street gangs. Like many of the other sociologists we have discussed, he was looking at the ways in which society caused crime and, in this case, encouraged people to band together. During the 19th century, immigrants had filled the inner-city neighborhoods, creating a more culturally diverse population. They faced deteriorating housing, poor employment prospects, and a rapid turnover in the population. These conditions created neighborhoods with weak and ineffective social institutions and social control mechanisms. Thrasher believed the lack of social control encouraged youth to find alternative ways to establish social order, and they did so by forming gangs. He described gangs as coming together spontaneously at first, then becoming bonded through conflict with other gangs and the surrounding community. What made Thrasher’s work unique from other theories with similar concepts (such as social disorganization theory and strain theories) was his identification of gangs as a subculture. Although he was the first to start down this road of studying subcultures, several other subculture scholars followed suit as they worked to understand gangs specifically and in a subcultural context. In the 1950s, Albert Cohen applied concepts from Merton’s strain theory and subcultural theories to juvenile gang formation. As with many early criminologists, Cohen saw juvenile delinquency primarily as a working-class, male phenomenon. This is because working-class youth are taught the democratic ideal that everyone can become rich and successful, but in school they encounter a set of distinctly middle-class values against which their behavior is measured. These class-specific values are framed as universal, making it much easier for middle-class youth to achieve recognition in school for behaving “correctly.” This leads to feelings of inferiority, which last as long as the working-class boys cling to that particular worldview. This strain is referred to as status frustration, for which status frustration theory is named. According to Cohen (1955), boys experiencing status frustration may adopt attitudes and standards that defy the mainstream middle-class ideals as a way of rebelling against them and relieving the guilt of not being able to live up to them. This response is referred to as reaction formation. The delinquent subculture presents young boys with a new set of values and a means of acquiring status within a different cultural context. For example, while the middle-class places value on controlling aggression and respecting property, the culture of the gang legitimizes violence and group stealing (Cohen, 1955). While the act of theft may bring material benefits, it also reaffirms the cultural cohesion of the new group and the status of its members. It is a joint activity that derives its meaning from the common understandings and common loyalties of the group (figure 6.20). Like Merton and Cohen, criminologists Richard Cloward and Lloyd Ohlin (1960) researched societal goals and the ability to achieve those goals. Incorporating concepts from Sutherland’s differential association theory, they heavily emphasized the different opportunities (some more legal than others) available for juveniles to get what they want. They noticed that some neighborhoods offered more opportunities to participate in illegitimate means (like theft or selling drugs) to achieve one’s goals. Their differential opportunity theory identified three different types of gangs that would develop based on the type of neighborhood and the legal and illegal opportunities offered there. The three gang types that can form according to differential opportunity theory are criminal gangs, conflict gangs, and retreatist gangs. Criminal gangs form in lower-class neighborhoods that already have organized criminal networks of adults who mentor the youth into crime. These illegal opportunities for achieving wealth facilitate this youth gang formation. Conflict gangs form in neighborhoods that are unstable and disorganized. Like their environment, these gangs are unorganized, and rather than engaging in organized crime for profit, members tend to use violence as a means of gaining respect within their neighborhood. This is because these neighborhoods lack legal and illegal opportunities for financial and material gain. Finally, retreatist gangs also form in areas where legal and illegal opportunities for gain are lacking. However, rather than using violence to achieve status and respect, the members simply want to escape from their reality and may engage in personal drug use to do so. For each explanation of male youth gang formation, the theorists explored the impact of social structure, learned behavior, strain and opportunity, and/or adherence to subculture norms. Additionally, they all recognized the unique status of adolescence and how it can make people more susceptible to peer pressure or feelings of inferiority. Check Your Knowledge Licenses and Attributions for Subcultural Theories of Crime Open Content, Original “Subcultural Theories of Crime” by Jessica René Peterson, Curt Sobolewski, and Taryn VanderPyl is licensed under CC BY 4.0. Figure 6.17. “Miller’s Cultural Deviance Theory” by Jessica René Peterson is licensed under CC BY 4.0. Figure 6.18. Subculture conformity graphic by Jessica René Peterson is licensed under CC BY 4.0. Figure 6.20. Juvenile delinquency graphic by Jessica René Peterson is licensed under CC BY 4.0. “Subcultural Theories of Crime Question Set” was created by ChatGPT and is not subject to copyright. Edits for relevance, alignment, and meaningful answer feedback by Colleen Sanders are licensed under CC BY 4.0. Open Content, Shared Previously “Gangs as Delinquent Subcultures” is adapted from “Delinquency as a Subculture,” Introduction to Criminology by Dr. Sean Ashley, licensed under CC BY 4.0, except where otherwise noted. Modifications by Jessica René Peterson, licensed under CC BY 4.0, include substantially expanding and tailoring to the American context. “Subculture” definition by Tonja R. Conerly, Kathleen Holmes, Asha Lal Tamang, Introduction to Sociology 3e, Openstax, licensed under CC BY 4.0. All Rights Reserved Content Figure 6.19.”Street Codes — Code of the Street, Elijah Anderson” by Code of the Street, Elijah Anderson is licensed under the Standard YouTube License. legal term describing the violation of a criminal law a group that shares a specific identity that differs from the mainstream majority, even though they exist within the larger society a statement that proposes to describe and explain why facts or other social phenomenon are related to each other based on observed patterns a state of normlessness in society, especially during societal transition a sociological term describing behavior that is outside of accepted social norms Cohen’s theory that four factors—social class, school performance, status frustration, and reaction formation (coping methods)—contribute to the development of gangs and delinquency in juveniles Cloward and Ohlin’s theory that juvenile gang formation depends on the neighborhood type and both the legal and illegal opportunities within it the theory that neighborhoods with weak community controls caused by poverty, residential mobility, and ethnic heterogeneity will experience a higher level of criminal and delinquent behavior Wolfgang and Ferracuti’s theory that certain norms and values, such as violence being an expected and normal response to conflict, are part of working-class communities and help explain violent crime Miller’s theory that the lower class have their own subculture and that parents in this group socialize their children into six focal concerns that run counter to mainstream culture Anderson’s theory that Black street culture places a high value on respect, which can lead to conflicts between community members a theory that assumes a society has conventional goals and means to achieve them and that people who are unable to achieve conventional goals due to blocked opportunities experience structural strain and may adapt in a way that involves criminal behavior the innate intelligence everyone has at birth Sutherland’s theory that criminality is learned through a process of interaction with others who communicate criminal values and advocate for the commission of crimes the framework and relationship between institutions, groups, and norms in a society; all the things that make up a society	3,789	common-pile/pressbooks_filtered	https://openoregon.pressbooks.pub/criminologyintro1e/chapter/oo6-4/	pressbooks	pressbooks-0000.json.gz:45950	https://openoregon.pressbooks.pub/criminologyintro1e/chapter/oo6-4/
xz8cku4xRlW-_crC	5.2: Two-Dimensional Image Representation	5.2: Two-Dimensional Image Representation Point Matrix To represent a straight-line image in computer memory, we must store a list of all the endpoints of the line segments that comprise the image. If the point $P_i=(x_i,y_i)$ is such an endpoint, we write it as the column vector \[\mathrm{p}_{i}=\left[\begin{array}{l} x_{i} \\ y_{i} \end{array}\right] \nonumber \] Suppose there are $n$ such endpoints in the entire image. Each point is included only once, even if several lines end at the same point. We can arrange the vectors $P_i$ into a point matrix: \[\begin{align} \mathrm{G} &=\left[\mathrm{p}_{1} \mathrm{p}_{2} \mathrm{p}_{3} \ldots \mathrm{p}_{n}\right] \nonumber \\ &=\left[\begin{array}{llll} x_{1} & x_{2} & x_{3} & x_{n} \\ y_{1} & y_{2} & y_{3} & y_{n} \end{array}\right] . \end{align} \nonumber \] We then store the point matrix $\mathrm{G} \in \mathscr{R}^{2 \mathrm{x} n}$ as a two-dimensional array in computer memory. Consider the list of points $\begin{gathered} P_{1}=(0,0) \\ P_{2}=(-1.5,5) \\ P_{3}=(4,2.3) \\ P_{4}=(4,-1) \end{gathered}$ The corresponding point matrix is \[G=\left[\begin{array}{llll} 0 & -1.5 & 4 & 4 \\ 0 & 5 & 2.3 & -1 \end{array}\right] \nonumber \] Line Matrix The next thing we need to know is which pairs of points to connect with lines. To store this information for $m$ lines, we will use a line matrix, $\mathrm{H} \in \mathscr{R}^{2 \times m}$. The line matrix does not store line locations directly. Rather, it contains references to the points stored in $G$. To indicate a line between points $p_i$ and $p_j$, we store the indices $i$ and $j$ as a pair. For the $k^{th}$ line in the image, we have the pair \[\mathrm{h}_{k}=\left[\begin{array}{c} i_{k} \\ j_{k} \end{array}\right] \nonumber \] The order of $i$ and $j$ does not really matter since a line from $p_i$ to $p_j$ is the same as a line from $p_j$ to $p_i$. Next we collect all the lines $h_k$ into a line matrix $H$: \[\mathrm{H}=\left[\begin{array}{lllll} i_{1} & i_{2} & i_{3} & \ldots & i_{m} \\ j_{1} & j_{2} & j_{3} & \ldots & j_{m} \end{array}\right] . \nonumber \] All the numbers in the line matrix $H$ will be positive integers since they point to columns of $G$. To find the actual endpoints of a line, we look at columns $i$ and $j$ of the point matrix $G$. To specify line segments connecting the four points of Example 1 into a quadrilateral, we use the line matrix \[\mathrm{H}_{1}=\left[\begin{array}{llll} 1 & 2 & 3 & 4 \\ 2 & 3 & 4 & 1 \end{array}\right] \nonumber \] Alternatively, we can specify line segments to form a triangle from the first three points plus a line from $P_3$ to $P_4$ : \[\mathrm{H}_{2}=\left[\begin{array}{llll} 1 & 2 & 3 & 3 \\ 2 & 3 & 1 & 4 \end{array}\right] . \nonumber \] Figure 1 shows the points $G$ connected first by $H_1$ and then by $H_2$. Demo 1 (MATLAB) Use your editor to enter the following MATLAB function file. Save it as vgraphl.m. function vgraphl (points, lines); % vgraphl (points, lines) plots the points as 's and % connects the points with specified lines. The points % matrix should be 2xN, and the lines matrix should be 2xM. % The field of view is preset to (-50,50) on both axes. % % Written by Richard T. Behrens, October 1989 % m=length(lines); % find the number of % lines. axis([-50 50 -50 50]) % set the axis scales axis('square') plot(points(1,:),points(2,:),'') % plot the points as * hold on % keep the points... for i=i:m % while plotting the % lines plot([points(1,lines(1,i)) points(1,lines(2,i))],.. [points(2,lines(2,lines(1,i)) points(2,lines(2,i))],'-') end hold off After you have saved the function file, run MATLAB and type the following to enter the point and line matrices. (We begin with the transposes of the matrices to make them easier to enter.) >> G = [ 0.6052 -0.4728; -0.4366 3.5555; -2.6644 7.9629; -7.2541 10.7547; -12.5091 11.5633; -12.5895 15.1372; -6.5602 13.7536; -31.2815 -7.7994; -38.8314 -9.9874; -44.0593 -1.1537; -38.8314 2.5453; -39.4017 9.4594; -39.3192 15.0932; -45.9561 23.4158] >> G = G' >> H = [ 1 2; 2 3; 3 4; 4 5; 4 7; 5 6; 8 9; 9 10; 10 11; 11 12; 12 13; 12 14] >> H = H' At this point you should use MATLAB's “save” command to save these matrices to a disk file. Type >> save dippers After you have saved the matrices, use the function VGRAPH1 to draw the image by typing >> vgraph1(G,H) The advantage of storing points and lines separately is that an object can be moved and scaled by operating only on the point matrix $G$. The line information in $H$ remains the same since the same pairs of points are connected no matter where we put the points themselves. Surfaces and Objects. To describe a surface in three dimensions is a fairly complex task, especially if the surface is curved. For this reason, we will be satisfied with points and lines, sometimes visualizing flat surfaces based on the lines. On the other hand, it is a fairly simple matter to group the points and lines into distinct objects . We can define an object matrix $K$ with one column for each object giving the ranges of points and lines associated with that object. Each column is defined as \[\mathrm{k}_{i}=\left[\begin{array}{cc} \text { first } & \text { point } \\ \text { last } & \text { point } \\ \text { first } & \text { line } \\ \text { last } & \text { line } \end{array}\right] \nonumber \] As with the line matrix $H$, the elements of $K$ are integers. Consider again Demo 1 . We could group the points in $G$ and the lines in $H$ into two objects with the matrix \[K=\left[\begin{array}{ll} 1 & 8 \\ 7 & 14 \\ 1 & 7 \\ 6 & 12 \end{array}\right] \nonumber \] The first column of $K$ specifies that the first object (Ursa Minor) is made up of points 1 through 7 and lines 1 through 6, and the second column of $K$ defines the second object (Ursa Major) as points 8 through 14 and lines 7 through 12.	1,307	common-pile/libretexts_filtered	https://eng.libretexts.org/Bookshelves/Electrical_Engineering/Introductory_Electrical_Engineering/A_First_Course_in_Electrical_and_Computer_Engineering_(Scharf)/05%3A_Vector_Graphics/5.02%3A_Two-Dimensional_Image_Representation	libretexts	libretexts-0000.json.gz:39034	https://eng.libretexts.org/Bookshelves/Electrical_Engineering/Introductory_Electrical_Engineering/A_First_Course_in_Electrical_and_Computer_Engineering_(Scharf)/05%3A_Vector_Graphics/5.02%3A_Two-Dimensional_Image_Representation
_Rv7OxqfDNDXv2dz	5.1.2H: Applied Body Language	5.1.2H: Applied Body Language - - Last updated - Save as PDF - Anonymous - LibreTexts Learning Objectives - Discuss the importance of body language as a means of social communication and give specific examples of body language Body language is a form of human non-verbal communication, which consists of body posture, gestures, facial expressions, and eye movements. Humans send and interpret such signals almost entirely subconsciously. It is impossible for social scientists to study body language in any manner that is not applied. Indeed, social scientists are interested in body language precisely because of what it conveys about social interactions and the relationship between nonverbal interlocutors. This dynamic can only be studied in applied contexts. Research has suggested that between 60 and 70 percent of all meaning is derived from nonverbal behavior, making body language a crucial part of social interaction. Body language may provide clues as to the attitude or state of mind of a person. For example, it may indicate aggression, attentiveness, boredom, relaxed state, pleasure, amusement, and intoxication, among many other clues. One of the most basic and powerful body language signals is when a person crosses his or her arms across the chest. This can indicate that a person is putting up an unconscious barrier between themselves and others. However, it can also indicate that the person’s arms are cold, which would be clarified by rubbing the arms or huddling. When the overall situation is amicable, it can mean that a person is thinking deeply about what is being discussed, but in a serious or confrontational situation, it can mean that a person is expressing opposition. This is especially so if the person is leaning away from the speaker. A harsh or blank facial expression often indicates outright hostility. Another obvious example of expressive body language used in everyday life is flirting. Flirting is a playful activity involving verbal communication and also body language to indicate an interest in a deeper romantic or sexual relationship. Flirting usually involves speaking and behaving in a way that suggests a mildly greater level of intimacy than the actual relationship between parties would justify, though within the rules of social etiquette, which generally frown upon a direct expression of sexual interest. Body language may include flicking one’s hair, eye contact, brief touching, open stances, and close proximity between partners. Thus, by watching two individuals, one can tell if they are flirting. Flirting Instruction : This video is a how-to on how to flirt. Note the significant attention paid to body language. Key Points - Research has suggested that between 60 and 70 percent of all meaning is derived from nonverbal behavior. - One basic body- language signal is when a person crosses his or her arms. When the overall situation is amicable, it can mean that a person is thinking deeply about what is being discussed, but in a serious or confrontational situation, it can mean that a person is expressing opposition. - Flirting is an example of applied body language. Sexual or romantic interest is primarily communicated through body language, which may include flicking one’s hair, eye contact, brief touching, open stances, and close proximity between partners. Key Terms - Flirting : It is a playful activity involving verbal communication and also body language to indicate an interest in a deeper romantic or sexual relationship. - body language : Nonverbal communication by means of facial expressions, eye behavior, gestures, posture, and the like; often thought to be involuntary. 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License : Public Domain: No Known Copyright	2,871	common-pile/libretexts_filtered	https://socialsci.libretexts.org/Courses/Collin_College/Introduction_to_Sociology/05%3A_Social_Interaction/5.01%3A_Social_Interaction/5.1.02%3A_Types_of_Social_Interaction/5.1.2H%3A_Applied_Body_Language	libretexts	libretexts-0000.json.gz:33921	https://socialsci.libretexts.org/Courses/Collin_College/Introduction_to_Sociology/05%3A_Social_Interaction/5.01%3A_Social_Interaction/5.1.02%3A_Types_of_Social_Interaction/5.1.2H%3A_Applied_Body_Language
PgNvI8Z_8DRWkqJG	The child-voice in singing, treated from a physiological and a practical standpoint, and especially adapted to schools and boy choirs, by Francis E. Howard.	PREFACE TO THE SECOND EDITION. /^^NE of tlie most encouraging signs of the ^-^ growth of musical taste and understanding at tiie present time as regards the singing of children, is the almost unanimous acquiescence of choirmasters, supervisors, teachers, and others in the idea that children should sing softly, and avoid loud and harsh tones ; and the author ventures to hope that the first edition of this book has helped, in a measure at least, to bring about this state of opinion. Jt is true that for a long time the art of training chiKli'cn's voices has been well understood by choirnuisters of vested choirs, and by many others, but its basis was purely emjurical. Something more, howe\er, than the dictum of individual taste and judgment is needed to convince the educators of our schools of the wisdom of any departure from established customs and practices. Tlie primary end, then, of tlie author has been to show a scientific basis for the use of what is hei'ein called the head-voice of the child, and to adduce, from a study of the anatomy and physioloijy of the larynx and vocal organs, safe principles for the guidance of those who teach children to sing. The conditions under which music is taught in schools call for an appeal to the understanding first, and taste afterward. These conditions are : First, the actual teaching of music is done by class-room or grade teachers. The special teacher, who usually supervises also, visits each room, it may be as often as once a week, but in most towns and cities not oftener than once in three or four weeks. At any rate the class form their ideals and liabits from the daily lessons, which are given by their grade teacher. Second, these teachers in the great majority of cases acquii-e tlieir knowledge of music thi'ough teaching it, and nmst also, it can easily be understood, devolo]) a sense of discrimination in musical mattei's in the same way. There is a sti'ong !iatiir;il tendency in the sclu>ol-i-ooiiift to emphasize the tcacJi'nvj of nnisie, or tc^achiii^ about music, as contrasted witii actual sin<j;in<^. The importance of using the voice; projierly will not suggest itself to many teachers. Jt is necessary, then, that this, which is the essence of all instruction in vocal music, .-hould he brought to the attention of tlie vast army of instructors in our public schools in as convincing a wav as is possil»le. Now the best, aiul in fact the only way to secure the assent of our educators to a new idea in school wik, is to prove its tiuth. '• It is useless to dispute aI)out tastes,"" and so the k>.-s said al)out harsh tone to a teacher accustomcil to heai' it daily, and to like it, the better; l)ut ])rove to this teacher that the liarsh tone is phvsically hurtful to the child, and that for piiysi<»logical reasons tlie voice should be used softly and gently, and you have w(»n a convert, one, too, who will <pnckly recognizt; tlm u'sthetic phase of the change in voice use. The author knows fi-om observation aiul experience that cliildi-en in the pid)lic sch<K)ls can. undei' exi.-ting conditions, be taught ^ood habits of voice \\^<i. There arc wonderful possibilities of musical development, in the study of music in schools, and the active interest of every musician and music lover should be exercised to the end that its standard may be kept high. PREFACB. TT will be generally admitted by those who are able to judge, that the singing of children is more often disagreeable than j)leasant, and yet the charm of childhood and the effect of custom are so potent that many who are keenly alive to any deficiency in the adult singer, listen with tolerance, and it would seem with a degree of pleasure even, to the harsh tones of children. This tolerance of rough, strident siTiging by children is as strange as the singing. It cannot be ri;;ht for children to sinf; with the coarse, harsh tone that is so common, and it is not right, although there is a prevalent idea that such singing is natural, that is, unavoidable. This idea is false. The child singing-voice is not rougli and harsh unless it is misused. The truth of this statement can be e^isily demonstrated. If it were not true it would Ix; ditHcnlt to ju.-^tify the teaching of vocal nni>ic is church clioirs. It seems to the antlior tliat tlie chief difficulty experienced by teachers and instructors of singing, in dealing with children, lies in the assumption, expressed or implied, that their voices are to be treated as we treat the voices of adults — adult women ; but the vocal organs of the child differ widely from those of the adult in structure, strength and general character. As a consequence, there is a marked dilference in voice. Vocal music has l)een very generally inti'oduced into the schools of our country during the past few years, and there is evidently a very general and earnest desire that children be taught to sing. It is also the wish of those who are teachers to do their work well. While there are many books to aid educators upon every other sul)ject taught in ])ubli(' schools, tiie literature on tlie voice, particularly the siuiriuir- voice, is meaure, and it is believed that some direct, j)ractical J/ints on this topic may be welcome. The f()lL>\\iii<; j)aj^es are tlic result of several vears' experience in teaching, and of careful study of cliiklren's voices. The author lias attem})te(l to describe the physiological characteristics of the child-voice and to give some practi<'al hints regarding its management. It is sincci-i'ly hoped that what is herein written may he uscfnl and helpful to those engaged in teaching children to sing, TN former times tlie culture of tlie siugingvoice was ciiuducted u{)ou purely empirical irrouuds. Teachers followed a few good rules wliicli had heeti logically evolvi'd from the expt-rieuce of many schools of singing. We nre indehted to modem science, aided by the laryngoscope, for many facts concerning the action of the larynx, and more especially the vocal coi'd.-- in tone-pi'oduction. While tlu' eai'ly discoNcries rcgai'iiing the mechanism of the voice were hoj)et"ully helieved to have solved all ))rol)lems concerning its culti\ation, experience has shown the futility of attempting to formulate a set of rules for voice-culture hased alone upon the incomplete data fui-nished hy the laryngoscope. This in.-trument isasmall, round mirror which i> introduced into the throat at such an angle, that if horizontal rays of li^ht are thrown upi'ii it, the larynx, which lies directiv heiU'ath, is illuminatecl and retlected in tlu' mii-- ror at the back of the moutli — tlie laryngoscope. Very many singers and teachers, of whom Manuel Garcia was the first, have made use of this instrument to observe the action of their vocal bands in the act of singing, and the results of these observations are of the greatest value. Still, as before said, the laryngoscope does not reveal all the secrets of voice-production. While it tells unerringly of any departure from the normal, or of pathological change in the larynx, it does not tell whether the larynx belongs to the greatest living singer or to one absolutely unendowed with the power of song. Also, the subject of vocal registers is as vexing to-day as ever. While, then, we may confidently expect further and more complete elucidation of tlie physiology of the voice, there is yet sufficient data to guide us safely in vocal training, if we neglect not the empirical rules which the accumulated experience of tlie past has established. The organ by which the singing-voice is produced is the larynx. It forms the upper extremity of the windpii)e, whicli again is the upper portion and beginning of the bronchial tubes, wliicli, oxtCTulinof downward, hrancli oil from its lowor part to eitlier side of the chest and coiitiinially subdivide until they become like little twii;s, around which cluster the cont^tituent })arts of the luniks, which form tlie bellows for the supply of air necessary to the performance of vocal functions. Above, the larynx opens into the throat and the cavities of the pharynx, mouth, nose, and its accessory cavities, wliich constitute the resonator for vocal vibrations set uj) within the larynx. The larynx itsolf consists of a framework of cartilai:;es joined by elastic membranes oi' liu'aments, and joints. These cartilaiii'S move freely toward and ui)on each otlier by means of attaclied muscles. .Vlso tlie larynx as a whoK' can be moved in various diri'ctions by means ol extrinsic muscles joined ttj points above and below. I'lie vocal bands are two lii:;aments or folds of mucous mcniluMne attached in front to the lai'U'c-t cartilage of the larynx, calied tlie tli\i'oid, and which foi'ins in man the piMtuberance com monly called Adam's apple; and, extending horizontally backward, are inserted posteriorly into the aryteniod cartilages, tlie right vocal band into the right arytenoid cartilage and the left band into the left cartilage. These arytenoid cartilages, by means of an articnlation or joint, move freely npon the cricoid, the second large cartilage of the larynx, forming its base, and sometimes called the ring cartilage, from its resemblance in shape to a seal ring. The vocal bands are composed of numberless elastic fibres running in part parallel to each other, and in ])art interwoven in various directions with each other. The fibres also vary in length; somt; are inserted into the extending projections, called processes of the arytenoid cartilages, and some extend further back and are inserted into the body of the cartilages. The vocal bands, then, lie opposite each other, on a level, raised a little in front, and with a nuiTow slit between, called t]iii glottis. The nniscles controlling the actiDii of the vocal bands, and which regulate the nicchanisni ])rodncing sound, are of three gi'onps, viz., abdnctoi's (drawing-apart nniscles), adductors (drawing-together muscles), and tensijrs. Tlie ahductors act to keej) the bands apart duriiiiij i-t'.-piratioii, while the I'linction of the a<lduetur.> and tensors is to bring the bands into po.-ition for s})eech or singing. They are, since jilionation is at will, voluntary nniscles; luit it is an interesting fact that the laryngeal nnisck\> of either side invarialily act together. It has been shown that it is not possible to move one vocal Cord without the other at the same time executing the same movement. It is thus shown that the laryngeal muscles are, to a less extent, under the control of the will than are those »>f cither hand or eye. The rational traiiung of the ringing- voice cannot, therefore, proceed upcdi any theory based npon the voluntary traininu- of the muscles controlling the movements of the vocal cords. The mucous nuMubrane which lines tlie larynx is libt'iMlly >up})lied with secreting gland,-, whose function i> to keep the j)arts iMoi>t. Abo\e tin; \ ociil bands, anotlu'r pair of mtMnbranou> ligamenl.- ai'c stretched across tin' lar\n\ forming, w itii its ,-idt's and t!ie vocal i)aiids, a pouch or pocket. The upper ligaments are ^ometimes called the false vocal cords, but are more proj> erlj termed ventricular bands. Their function has occasioned much speculation, but whatever modification of tone they may be supposed to produce, they no doubt protect the true vocal bands and permit their free vibration. The larynx, in the j^roduction of sound, may be compared to an organ-pipe. The two vocal cords which act simultaneously and are anatomically alike, when set in viljration by the blast of air coming from the lungs, correspond to the ree<l of the organ-pipe; the vibration of the cords, producing sound, which is communicated to tlie air enclosed in tlie cavities of the chest and head. Pitch of tone is determined by the rapidity of vibrations of the bands, according to acoustical law, and the length, size, and tension of the cords will determine the number of vibrations per second, •?'. e., their rapidity. Strength or loudness of tone is determined primarily by the width or amplitude of the vibrations of the vocal membrane, and quality or timbre is determined by the form of the vibra tion. The infinitely varyinj^ luiatonnciil (liver<;cncics in the form and structure of tlie iiabul, phai-yngeal and throat cavities, and possibly the composition of the vocal l>ands,modifie8, in numberless ways, the character of tone in s{>eech or soni:;. It is a fascinatini;- topic, hut nnist he (Usniissed here with the remark that, as those anatomical ditl'erences in structui'e are far less marked in cliildren than in adults, their voices are, in consc(pience, more alike in quality and strenicth. It takes loui;-, patient trainini;; to hlend adult Voices, hut children's voices, when prt>[»erly uscmI. ai"e lionio^ciieous in tone. Tlie Voices of hoys and i;irls, ])rior to the au'c of puberty, ai'e alike. The growth of the larysix. wliich in each is (piite I'apid up to the age oi six yeai's, then, according to all authoi'ities with which tlie wi'iter is con\"ersant, ceases, and tlie V(.)cal iiands neither lengthen nor thielven, to any ajipreciahle extent, before the time of change of voice, which occurs at the age of j 'liberty. period of the child's h'fe, extending from the age of six to fourteen or fifteen years. In point of fact, authorities upon the subject refer only to the lack of growth and development in size of the larynx during the period ; but undo uhtedhj^ duriiuj these years, there is a constant gaining of Jirmness and strength^ in hoth the cartdages and their connecting mendyranes and muscles. Xone of the books written upon the voice have even mentioned this most important fact. It bears with great significance upo!i qnostic^ns relating to the capacities of the child's voice at different ages, and explains that phenomenon called the " nioval)le break," which has j)uzzled so man^MU their investigations of the registers of the child's voice. The constant, tliuugh of course extremely slow, hardening of the cartilaginous portions of the larynx, and the steady increase in the sti'cngtli of its muscles and ligaments is not in the least iiiconsisteiit with the j)i'eviouslv noted fact, that tlie vocal bands during this time increase to no appreciable extent in length; for, it may ])e observed, aftei- the t'lijviige of voice, wliicli ofti'ii occurs with i^rcat rapidity, and diii-iii^ wliicli tlic vocal hands increase' to (hiiihle tlicir previous len<;th in males, that, thdiii^li tlie pitch of tlie voice, owiiit; to increased K-nt^th of the han<ls, sudtU-nly h)\vers, vet not until full maturity is reached, do tlie lai-vuueal cartilai::es attain that I'iiridity, or the vocal hands that ready elasticity I'ssential to the production of \n\V(.\ lesouant voice. Vet, during these years, while the voice is developiuir, the vocal hands I'cmain unchan<j:ed in A //y///. l']ven in those ca.--es where the \-oice changes slowlv in conse(pience of the slow ijrowth in len::th and thickness of the \'ocal coi-ds, it takes .-evei'al ycai'>. after laryni^fal develoj)ment has ceased, for the voice to attain its full si/,e and re.-oiiance. I'"urt]ici"mor(>, th(^ continual increase in ,-ti'eiiirth and tirmness of the lai'ynx from six \cars ouward to juiliei-ty. is coii.-i.-tent with the c )n>tant i:i"o\\th in >treiiuth and iii'nmess of tissue charaeteri/.ini:- the entii-e hody. It is ai;-ain proN'eii liy the eontiiiu.d iMi\|iro\ement in the power ami timhre ot the tone throU!;'h thi> peri- 0(1, always premising, be it understood, that the voice is used projjcrly, and never forced beyond its natural capabilities. The voice, at the age of eleven or twelve, is far stronger, and is capable of more sustained elfort than at the age of six or seven years, and, for the year or two preceding the break of voice, the brilliance and power of boys' voices, especially in the higher tones, is often phenomenal, and in all cases is far snjierior to that of previous years. The resemblance between the voices of boys and girls, a resemblance which amounts to identity, save that the voices of boys are stronger and more brilliant in quality, disap2)ears at puberty. Among the ])hysical changes which occur at this period is a marked growth of the larynx, sutlicient to alter entirely the pitch and character of the boy's voice. As a female larynx is alfected to a lesser extent, the voices of girls undergo little change in })itc]i, l)ut become eventually nioi'e powertui, and richer in tone. but often a year or two earlier, and not infre(juently a year or two later. The iri'<'Wtli of the larynx ijoes o?i, with greater or less ra[)i(lity, \ai-yini; in dilTermt individuals, for from six months to two or three years, until it attains its tinal size. In hoys, the larynx douhles in size, and the vocal hands increase in the [)r(^])(»rtion of live to ten in length. This great gain in the length of the vocal coivls is due to the lateral development t)f the larynx, for the male larynx, in its entirety, increases more in depth tlian in height. The residt is a dro{) of an octave in the average hoy's voice, the longer hau<ls producing lower tones. The change in size in the ft'male lai'vnx is in the proj)ortion of tive to seven, and the increase is in height in.^tead of deptli or width as in the male larynx. 'J'he Vocal cords of women are, therefore, shorter, thiimer and narrower than are tliose of men. The reason assigneil (i>v tlie peculiar antics of tiie hoy's voice, diii'iiig thi- l)i'cak, is une(\|ual I'apidity in the gmwtli and dcNclopmcut of the L-artilai,fes and of the muscles of the larvnx. The muscles develop more slowly than do the cartilag-es, and so abnormal physical conditions produce abnormal results in phonation. No further changes occur in the laryngeal structure until middle life, when ossification of the cartilages connneuces. The thyroid is first affected, then the cricoid, and the arytenoids much later. The consecpient rigidity of the larynx occasions diminished compass of the singing-voice, the notes of the upper register being the first to disappear. In some few cases of arrested development, the voice of the man retains the soprano compass of the boy tiu'ough life. KKCJKSTKKS OK THK VOICK. IT may be obstTvi'd, in listeiiiiitj:; to an ascend. in<; sei'ies of tones suni^ by an untrained or l>y a badly-trained a(bdt voice, that at certain pitches tiie tone-(jnality under<i;oes a radical chani^e ; while a well-trained singer will sinij the same series of tones without showing any appi'eciable break or cliange in tone-(\|uality, although the highest note will [)rcs('nt a niai-ked Contrast in timbre to the lowest. Tht; brt'aks or changes in register so noticeable in the unti-ained voice are covered or e(\|nalized in the \<>ici' trained by correct methods. These breaks in both male and female voices occur at certain pitches wlicrt' the tone-j)i'oducing mechanism of the larynx changes action, and bi'ings the vocal band> into a new vibi'atory foiMii. '• .\ register consi>t> of a series of tones j)roduce(l bv the same mechanism."- — Kmil i!ehid<e in '" \'oice. Song, and Speech." (i. Kdwai'd Stubbs, in connnenting ujion the aboNc detinition, says; 2.? "By meclianism is meant tlie action of the larynx which produces different sets of mhrat'tons, and by register is meant the range of voice confined to a given set of vibrations. In passing the voice from one register to anotlier, tlie larynx changes its mechanism and calls into play a diiierent form of vibration." The number of vocal registers, or vibratory forms, which the vocal bands assume, is still a matter of dispute, and their nomenclature is equally unsettled. The old Italian singingmasters gave names to parts of the vocal compass corresponding to the real or imaginaiy bodily sensations experienced in singing them; as chest-voice, throat-voice, head-voice. ]\[adame Seller, in "The Voice in Singing, '' gives as the result of original investigations with the laryngoscope five different actions of the vocal bands which she classifies as "first and second series of the chest-register," " first and second series of the falsetto register" and "head-register." Ih'owjie and I'ehnke, in "Voice, Song, and Speech," divide the male voice into three registers, and the female into five. They are termed "lower tliick," " upper tliick," "lower thin," "upper thin" and • small." Other writers speak of three registers, "chest," "medium" and "head," and still others of two only, viz., the chest and the head. Modern research lias sliown what was after all understood Ijcfore, that, if the vil)ratory form assumed l)v the vocal bands for the natural production of a certain set of tones is pushed Ity muscular exertion above the point where it should cease, intlamniation and weakening of the v(X?al organs will result, while voice-deterioration is sure to follow. A physiological basis has reinforced the empirical deductions of the old Italian school. In dealing with children's voices, it is necessary to recognize only two registers, the tliick, or chest-register, and the thin, or liead-register. Further subdivisions will only complicate the subject without assisting in the practical management of their voices. Tones sung in the thick or chest-i-egister are ju'oduced l)y the full, free vibration of the vocal bands in their entire lemcth, breadth and thick- tlieir inner edges alone. We may then conclude from the foregoinc; that children nj) to the age of puberty , at least in class or chorus singing, should use the thin or head-register only. 1st. It is from a physiological standpoint entirely safe. The use of this register will not strain or overwork the delicate vocal organs of childhood. 2d. Its tones are musical, pure and sweet, and their use promotes the growth of nnisieal sensibility and an appreciation of beauty in tone. 3d. The use of the thick or chest-voice in class-sinii:ing is dangerous. It is wellnigh impossible to confine it within ])roper limits. It is unnecessary to discuss the second point. Anyone who has noted the contrast between th(; harsh quality of tone emitted from childish throats when using the chest-voice, and the pure, flute-like sound ])roduced when the headtones are sung will agree that the last is music and the first noise. <>r at any rate very noisy, barbaric music. The tliird jK>int, if true, estiiblishes tlie first, fur, if the chest -voice cjuiiiot he safely used, it follows that cliildrcu must use the head-rci^istcr or stop sinking. It must he said, hefore proceediu^ further, thiit it is not denied that the thick voice can he use<l hy children without injury, if ])roj)crly manau'cd ; that is, if the singiiii; he not too loud, and if it he not carried too hii^h. It is also fully i-ccon-nized, tliat, wluiu theoretically the head-voice alone is used, it yet, wlien carried to the lower tones, insensihly hlends into the thick iv<j;ister; hut if this e(\|ualization of re^istei's is oI)tained so comj)letely tliat no perceptihle dilfei'ence in (piality of voice can hi' ohserved. why then the whole com[)ass is j)ractically the thin oi- head-ri'i;ister, A'ow, can the tliick voice l)e used in schoolsin^ini;-. and coniiiKnl to the lower notes? And is it fairly easy to secure soft and j)Ui'e vocalizations in tliis i'eiii>tery Let the i'\j)erience of thousands of teachei's in the piil)lic schools of this and otiiei- lands answer rhe last i[Ue>tion. of youngsters to s])eak softly at a game of baseball, as to induce them, or girls either for that matter, to use the voice gently, when singing witli that register in which it is possible to push the tone and shout. There should be some good physiological reason for the habitual recourse to the strident chest-voice so common with boys, and nearly as usual with mrls. And there is a i»:ood reason. It is laek of I'igidity in the voice-box or larynx.. Its cartilages harden slowly, and even just before the age of })uberty the larynx fidls far short of the lirmness and rigidity of structure, that characterize the organ in adult life. It it physically very ditficnlt for the adult to torce the chest-voice beyond its natural limits, which become iixed when full maturity of bodily devek)pment is reached, but the child, whose laryngeal cartilages are far moi'o flexible, and move toward and njxjn each other with greater fi'cedom, can force the chest - voice up with great ease. The altitude of piteli which is attained l)eforc breaking into the thin register is with young children regulated by the amount of inusculiir exertion tliey put forth, Even ii\|) to tlie ehtuiije of voice, hoys can often fdrce the tliick reijister several notes higlier than Women sopranos. It must he horne in mind that the tliick voice is produced hy the full, free vihrations of the vocal hands in their entire length, hreadth and thickness. Imagine children six years of age carrying tones foi'med in this manner to the extreme limit of their voice ; yet they do it. The tone of infant classes in Sunday-schools, and the tone of the primary schools, as they sing their morning liynins or songs for recreation, is j)i'oduce(\| in nine hundi'cd and lunety-nine cases out of a thousand in exactly the way si't forth. If tlic vocal hands of children wei'e less elastic, if they wci'e coin])osed of stronger tihi'cs. and protected from undue exertion hy lirm connecting cartilage; in short, if clnldren were not children, such forcing would not he \|)os>il)le. If it were not for the wondei-fui recuperative power of cliildiiood, sei'ious eifects would follow such Vocal hahits. We are now ])re])ared to inulcrstand tliat common phenomenon of the cliild-voice, termed the "movable break.'" Every j)nblic school teacher who has had experience in teaching singing must be familiar with the meaning of the term, thongh possibly unaware of it. Allusion has already been made to the fact that, in primary grades, the thick quality, if ])ermitted, will be carried as high as the children sing, to for example. If they are required to sing the the higher tones lightly, then the three or four tones, just l)elow the pitch indicated, will be sung in a thin quality of voice. The place of the break or the absence of any break at all will depend upon the degrei; of loudness ])ermitted. The pitcli at which the hreak occurs will vary in individual cases accordinic ti> physique or ambition to siui:; well; hut the l>oys (excludiiii; those whose voices have begun to hreak) will niainfest the utni(»st repugnance to singing the higher notes. '* ( "an't sing liigh ' ' will he the reply when ynu ask them why they do not sing. And they are corri'ct. They cannot, not with till' thick voice. I']ven when [Mitting hd'th con,-i(U'i'ahle exertion, they will pass to the thin \oice at and lowei'. if they siu^^- softlv. 'i'his phenomenon. then, i> t lu' " iiio\ alije l)reak " ' of the child -voice. The jiitcii at which the chiid-Noice \|)asses iVotn the thick to the thin voice depend.^ tir>t upon the age; >econd. u])on the auiouin of physical vigor of the child. It may also ])e added that ])oys' voices break lower than girls' during the year or two preceding change of voice. When, now, it is remembered that the adult female voice leaves the chest- register at it will be admitted by everyone who has had actual experience in class singing in schools or elsewhere, that the facts set forth in reference to the al)ility of the child to carry the thick voice from one to eight tones higher tluin the adult, has a very important bearing on the subject of training childi-en's voices. But, is it physically injui-ions? It may l)o said that, as regards upward forcing of the v<_)cal register, authorities u])on the adult voice are anited. Leo Kofier, in " The Art of IJrcjtithing," p. lf)S, says: "1 liave met female rrel)les that used tliis means of forcing up the cliest-tones as high as middle A, 1>, (\ and (one caniiardly conceive of the physical ])ossibibty of so doiTiLr) even as far as I) and E flat. The reason wliv this j)racticc' is so (laiii^croiis lies in the nnnatui'al wav in wliicli the larynx is liehl down in tlic throat, and in tlie force tliat is exercised l>y the tension mnsck's of the vocal liixaments and tin; hard pressnre of the muscles of the tontjueIxtne. . . I have examined with the larynii;osco})e many ladies who had tliehal)it of sini:;in<; the chesttones too In'ah, and. without exception, I have found their throats in a more or less diseased condition. Laryngitis, eithi'r alone or complicated with pliarynii-itis, relaxation of the vocal litraments, an<l .-omctimes paralysis of one of them, are the most frcfpient results of this had hahit. If a sinp'r i> atllicted with catarrhal troulde, it is always auiri'avated by this ahominahle method of >ini:inir. " Mmma Seller, in ''The \'oice in Siiijjfini;.' ]i. T)}, after dex-i'iltiiiiT the action of the vocal li^-anuMit.- in the pi-o(luetioii of the chest-voice and allndiiit:' to the fact that .>ucli action can he contimie(j .-cscimI t(tiies liii:-hei' than tiie pi'oj)er ti-an>itioii,il point. ::des on: " Ihit such tones, e>peciall\' in the teniale voice, lia\ e that roun'h and common timbre, wliieli we are too often compelled to hear in our female singers. The glottis also in this case, as well as ])arts of the larynx near the glottis, betrays the effort very plainly; as the tones ascend, they grow more and more red. T//i(s, as at fJ(i.s itJacc in the chest-7'egiste7\ tJicre occurs a vislhleajul sejisihle strainivg of the organs, so (dso is it in all the remaining transitions, as soon as the attempt is made to extend the action htj irhidi the lower tones are formed heyo)id the gicen limits of the same.^'' And again : "In the ignorance existino; concernino: the natural transitions of the rei»:isters, and in the unnatural forcing of tlie voice, is found a chief cause of the decline in tlie art of singing, and the present inability to preserve the voice is the consequence of a method of teaching unnatural, and, therefore, imposing too great a sti'ain upon the voice." (^)uotations inmimei'able niiglit l)e made, to give more emphasis, were it needed, to the evils of register for cing. tlu' cliest or thick voice? If their v(»ciil organs are so Hexihle, may tliey not carry such tones higher tlian a(hilts, and youni^er cliiUh'en higher than tliose a Httle ohU'r, and so on? It is (juite ohvious. for reasons lierein set forth, tiiat chil(h"('ii d(» not experience the same (k'gree of dithciihy in coiitiiuiiiig the nse of the tliick Voice to their liigher tones as (h> adnlts, hut as to tile etfcct u\|)oii theii- vocal organs there need he no rea>nii,iMe <h»iiht. A. B. Baeli, in •' Priiici{)Ies of Singing,'' p. 142, says: "If children arc allowi'd to sing their higlier notes forte, hefore the voice is properly e<pialized, it will hccoini' hai'd. harsh and hoarse, and tliey will fail in coi-rect intonation. A mistake in this dii-cction not <>nly I'uins the middle register hut destroy.^ the voice altogether. The coiise(pience of encouraging foite singing is to change a soprano rapidly to an alto; and they will generally sing alto eipudly forte hecause their \-ocal coi-ds ha\e lost their elasticity thi'ough o\(.'i'>t raining and the notes will no longer breaks tlicm forever," It may be observed that the writer cited evidently accepts the same elassiiication in register for children and adult women's voices, but this does not make the above extract any less applicable. The baneful effects of forcing the voice is clearly set forth. How to avoid it is .mother matter. Leo Kotler, in the work previously mentioned, p. 108, refers to this point as follows: " It frequently happens that the tones of the lower range, or the so-called chest-tones, are forced up too high into the middle range. This Ixid habit is often contracted while the singers are quite young. Boy trebles have this ha])it to an unendurable degree, usually screaming those horrible chest-tones uj) to middle C. Of all bad habits, this one is the most liable to injure a voice and to detract from artistic singing." To cite Madame Seller once more, p. 17<): '* AVhile it often happens that at the most critical age while the vocal organs are being develo})ed. children sing with all the strength they can command. l><»ys, however, in whom the larynx at a certain period undergoes an entire traiisforination, reach only with ditHcultj the hi<;her s<)})rano or contralto tones, hut arc not assigned a lower j)art until perceiviniji; themselves the inipossihility (»t" sin<;in^ in this way, they he^ the teacher for the chaiii^e, often too late, unha])))ily, to prevent an irreparahle injury. Ar<)derate sin<j:inij:; without exertion, and above all things, within the natural limits of the voi'.-e and its registers, would even during the peri(Kl of growth be as little hurtful as sj)eaking, laughing or any other exercise which cannot be forbidden to the vocal oi'gans." Hrownc; and iJehnke, who separately and together have given most valuable additions t(t the literature of the voice, in a small book entitled " The Child- N^oice,'' have collated a large numlxM' of answers from distinguished sinii'ers, teachers and choii'-trainers to various (piestions relating to the subject. I'he following citation is fr(»m this intei'esting work, p. ;!!• : '' The nece>sity of limiting tlu; compass of childi'cn's voices is fr('(pu'ntly insiste(l uj)()n, no attention whatevci" being paiil to rtyJ-sfrr.s-' and yet infinitely more mischief is done by forcing the registers tlian would ])e accomplished by allowing children to exceed the compass generally assigned to them, always provided that the singing be the result of using the mechanism set a])art by nature f?r different parts of the voice. ' ' There can really be no doubt that the use of the chest or thick voice upon the higher tones is injurious to a child of six years, or ten years, or of any other age. The theory that in the child voice the breaks occur at higher tixed pitches than in the adult is shown to be untenable. The fact would seem to be that comparisons between the registers of the child and the adult voice are misleading, since the adult voice has fixed points of change in the vocal mechanism, which can be transcended only with great difficulty, while the child-voice has no Jij'ed jmi^ts of change in Its vocal )€(ji'<ters. This point must not be overlooked. It is the most important fact connected with the child-voice in speech or song. It is the fundamental idea of this work and is the basis for whatever snggestions are hci'cin contained upon the management of the child-voice. The i'i<rid- ity of tlic adult larynx, tlie stri'iiirth of tluK'lisoi- and adductor iiiusc-les and the elastic tiriiiness of the vocal litrainents, are to those of the child as the solid houy framewoi-k and stron<xly set muscles of maturity are to the imperfectly hardened hones and soft musck'S of childhood. Nature makes no tixed limits of the \'ocal reikisters until full maturity is reached. A tix(Ml register in a childish throat involviiii; a com])leti'ly de\i'loj)ed larynx would hi' a startling'' anomaly. The laryni:;eal nuiscles of cliildhoo<j are not stronji:. They are weak. Most of the talk about streni^^th of voice in children is utter nonsense. AVhen the nuiscles and other parts concei'iu'(l in toiu'-production j)ei"form their j>liy>iolo<ric;il functions in a healthy manner, tliMt is, in such a way that no con<j:;estion, or iutlaiiim.irion or undue weariness will result, the >iii^iii:r-toiu' >■>{ the child will lU'Vt'i' i)e loud, lliu-li or low, under tlioe couditions it must ])ei-{iWrr he sol't. and if pi'opei" directions he folloW((l the (piality will he as ^o(i(l as the voice is capahle i>f. the contrast in tlie lower tones of children and women. The cliest-voice of the woman, which she uses in sin»i:;ing lier lower register, is normally very beautiful in its quality. Its tones are the product of a perfectly developed, full-grown organ. The chestvoice of the child is an abnormal product of a weak, growing, undeveloped organ. It possesses, even when used carefully, little of the t(jne tints of the adult V(jice. The chest-voice belongs to adult life, not to childhood. The socalled chest-voice of children is only embrj'onic. It cannot be musical, for the larynx has not reached that stage of growth and development where it can produce these tones musically. The constant use of this hybrid register with children is injurious in many ways. Its use is justified in schools raei'ely thi-ough custom, and it can not be doubted that as soon as the attention of teaciiei's is called to its evils, they will no longer tolerate its use. The usual analogies then which are drawn between the adult female voiceand the child-voice, in so far as they imply a sinn'lar physiological con- (litioii of tlie vocal origan aiul similar vocal training, are not only useless, but mislcadiui;. He who tries to train the average child- voice on the theory of two, three or five clearly-defined breaks, or natural changes in the forms for vocal vibration assumed by the vocal i)ands will get very little help fi'om nature. AVith due consideration it is said that it is a harder task to train children's voices j)r(»j)erly than to ti'ain the voices of adults. Where nature is so shifty in her ways, it recjuires keen j)enetration to discover her ends. HOW TO SECUKE GOOD TONE. 'TT^IIE practical application cf the tcacliiiiij: oi the two prucuding chapters niav at tirst thoni;-ht .seem to he (liilicult. On the contrary, it is (juite easy. We have favoral)le conditions in schools; g-radetl courses in music, reii;ular at tendance, discipline, and women and men in change who ai'e accustomed to teach. TSo more favorahle conditions for teaching vocal music exist than ;ire to he found in a welhorganized and well-disciplined school. The envir(^)nments of hoth ))upils and teachers are exactly adapted to tlio ready ref'0])ti()ii of ideas, on tlie one liaiid. and tlie skilful iiupartiiii; of tlieni, on the other. The abilities of tlii* trained teaeliers of to-day are not half ai)i)reciate(\|. They often possess ])rofessional skill of the liiijhest ordi'r, and the su})ervisor of iinisic in the pnblie sehools may count himself exceedingly fortunate in the means he has at hand for carryini; on his work. IViit knowledua' of voice is no more evolved from one's inner consciousness than is kno\vledi]^e of musical notation, or of the (ii-cck alphaht't ; therefore, if rt'u-ulai' teachers iu the school permit siutrini:; which is unmusical and hurtful, it is chiefly because they are followiiii:- the usual customs, and their <'ars havi- thei'ehy liecome dulU'd, or it may he that even if the siiiLiino- is unpleasant to them, that they do tiot knoir Iioir to make it hetter. .\s hetoi'e <ai(i, all ciieriries have so far heeii dii'ected to the teachimj,' of music rea<lin^. Tone has heeli n''u-]ecte(l, foi'irotteu, oi' at most its improvement has heeii souu'ht spasmodicall v. The cai'elessiie>s i-ei;-ai"diiii:' tone, which is so prevalent, is due to an ahno>t entire al)>ence of \f{nM\ teachinir on the ^uliject i;f tile <-hilil- N'oice excusable. Now and tlien, when listening to the soprani of sonic well-trained boy-choir, sounding soft and mellow on the lower notes and ringing clear and tlutey on the higher, it may have dimly occurred to the teacher of public school music that there might be things as yet unheard of in his musical philosophy, a vague wonder and dissatisfaction, which has slowly disa})peared under the pressure of routine work. When one reflects upon the results which the patience and skill of our regular teachers have accomplished in teaching pupils to read music; it can never be reasonably doubted that the same pati<^,nce and skill, if rightly directed, will be equally successful in teaching a correct use of the voice. cacli irrade, if pupils siiii:; softhj ()iou<fh, aiid carrv tlu-ir tdiics iicitlu'i' too liii^li nor too low, alwavs takiiii^^ into account the irrade (»r avcrai^c aijr of tlic class, tlicn the voice will he used only i)i tin: tli'in or In ad-n >/lsf( )\ and the tones of the thick or chest- rei,dster will never he heard. Unt the two I'ules must he as one, for if soft siuiiiiii:- he caiTie(\| too low with infant voices, they ari' foi'ced to use the thick tones; and children of all a;^a's. even if siiiii-ini; within the I'iulit compass ot \-oice, will use the thick rci^ister if permitted to sinir t(M» loud. Tlu'i'i' is nothiiiir particularly oriirinal in in sistin:Lr ui)on soft sinixiiiij: from children. The writer h«s never seen a hook of school music that docs not mention its desirahilitv, nor hardly a I'cfei'ence to the child-\dice in the standard woi'k> oi- writings of the day (»f whicdi this idea lia> not foi'me(l ;i part. The L^eiK-ral direction '"Sinir softlv ' is ^ood so fai- a> it u'ocs. hut is. tiivt, indetinite. Softly aii<l loudly are i-elati\-e tei'iiis. and suhject to wide di\-c!'>ity of iMter])i'ctat ion. 'i'lic pianissimo of a cull i\atrd .-iiiiicr i> .-ileiice CDinpai'ed to tlic tone emitted by vocalists of the main strengtli order, when required to produce soft tone. Secondly, the direction is seldom or never found coupled with instruction upon the vocal compass of children. Hence, it does not seem very strange that the injunction "Sing softly " has not (corrected vocal errors in school singing. It is not easy, it is even impossible, to accurately define soft singing, and no attempt wiU be made further than to describe as clearly as may be the degree of softness which it is necessary to insist u])on if we would secure the use of the thin or head register. The subject of register has already l)ccn discussed, but it may not be amiss to repeat just here that in the child larynx as in the adult the head-register is that series of tones which are produced by the vibration of the thin, inner edges of the vocal band. If l)reathiiig is natural, and if the throat is open and relaxed, no strain in singing tliis tone is ]K)ssil)le. It is evident in a moment tliat cliildi'cn with their thin, delicate vocal lii;-am{Mits can make tinstone even more easily than adult sopranos, whose vocal liijaiiients are loiiijer and thicker; and it is also perfectly evident that no danger of strain t(» the vocal hands is incurred when this voice is used, for all the muscles and lii;aments of the larynx are under far less tension than is re(juii'cd for the })roduction of tones in the thick register. It nnist also hi' rememhered in connection with this fact, that children often enter school at live years of au'c, and that accordiuij: to physiologists the laiwnx dot's not reach the full i^rowth in f<h(\ incidental to childhood until the iti^^c of six years. AVe must then he j)articularlv careful with infant classes — for the vocal bands of cliildren prior to six vears of age are very, vcr\ weak. Speakiiiii' of infant voices. Mr. AV. M. Miller, in Browne and J5elinke's afore-meiitioiicd woi'k, ' The Cliild - A^oice," is (pioted as saviiiLT* '' Voice-/'/'a/////'y cannot he attempted, hut voice(lestrnctliju may he prevented. iSoft singing is the cure for all the ills of the vocal origans." It WduM he hai'il to tind a nioi'e terse or ti'uthful htatement than tlie tir>t >entence id' theahove as regards tlie voices of little children from live to seven or eight years of age. It is nnniitigiited foolishness to talk about vocal training as applied to children of that age. The voiceculture which is suited to little children is that sort of culture wliich promotes growth — food aTid sleep and play. As well train a six months' old colt for the race track, as attempt to develop the voice of a child of six or seven years with exercises on o, and (Ji, ^//c/?i2,svs/7«c» and forthsimo^ crescendo^ diminuendo and stcell. Their voices nnist l)e used in singing as Ihjldly <(k possible. This answers the (piestion, how sctftly should they sing? Two or three i)ructi('al ditliculties will at oncc^ occur to the teacher with reference to songs and exercises which ran<j'(i lower than E first line, The snhji'ct of compass of eliihlren's voices will l)c discussed at some length in a followini; cha])ter, but for the present it may be said thai the ditHcnlty with sonijjs and exercises ran«;in',' below the pitch iiidicate(l may be overcome easily by pitchiiii; the sonirs, etc.. a tone oi" two hiirher. If they then ran<;e too hiirh, don't sinij them, sinu: somcthinii^ else. In teaching; the scale, take \\ o!" 1"' as the keynote, and siiiir either one oi" the other of those scales lirst. The chil(h-en must sini!; as softly as possible in all their .-iuuiuii: exercises^ whether souj^s or note drilh They >hould l»e taught to opi'U their moutlis well, to sit or stand erect as the case may lu-. and under no circumstances should tluiii.-rrnctor siiit; with tliem. Too much importance can hardh- be <xi\('n to this last statement, if teachers pei->i>t ill leaijinir the song's with tlieiiown \(iices and in >ini,''iiii; exercises with the c]iil(h-eii. they can and mo>t probably will ilefeat all etlnrts to >eciire the ritcht tone in either the lir>t. oi' any i,n'a<ie U[> to that m which changiMl voices are foniid. Tliis sounds rather cynical, and inig-lit seem to imply that instructors camiot sing well. The meaning, howi^ver, is quite different. The qnalitv or tind)i"e of the adult womaiTs voice is wholly unlike that of the child's thin register. Her medium tones, even when sung softly, have a fuller and more resonant (juality, and if she lead in songs, etc., the pupils, with the proverbial aj)titude for imitation, will inevitai)ly endeavor to imitate her tone-quality. Tiiey can only do so by using tlu; thick register, which it is so desirable to utterly avoid. Tt is worse yet for a man to lead the singing. Neither should one of the ])npils be allowed to lead, for not only will the one leading force the voice in the elfort, but a chance is offered to any ambitious youngster to ])itch ii> and outsing the leader; from all of which follows naturally the idea that all prominence of individual voice nmst Ix; discoui-aged, forbidden even. The songs and exercises must be led, it is true, but by tlie teacher and ^iUnilij. Then, a^ain, uidess the teacher is silent she cannot be the lesson. Certainly it is often necessary for the teacher to sin^, hut only to illustrate or correct, or to teach a soiii!;. In the last, if the teacher will remain silent while the class re])eat the line sunir to them, and will pi'oceed in the same way until the whole is memorized in* the class, not oidy will time he economized, l)ut the tone can he ke})t as soft as is desired and individual shoutcrs checked. Once more it must he insisted that soft, very soft sint^dni; only, can be allowed. Children of the aires mentioned can, as has already heeii shown, break from the thin to the fliick \-oice at any })itch, it oidy re(]uirini; a little extra })U>h for the upper tones. Finally, as an excelli'iit tt'st to settle if the tone is soft cnouu-h to ensure the use of the thin I'eiri^ter bi'Voiid doubt, re(piii'i' the class to sini: so that no pai'ticular voice can be distiiii;uished from the others, which will make the tout' as that of one Voice, and [)ei-haps lead you to doubt if all arc singing, until convinced by the move nient of their mouths. The tone will seem pretty light and thin, but will be sweet as the trill of a bird. To Dlxfinyuish Rcgistfers. The difficulty which may be experienced m attempting to distinguish between the two registers must not be disregarded. If the voices of children were never entrusted to any save ])i"ofessional voice-teachers, a very few hints upon their management would perha})s suiHcc, for tlic ear of the teacher of voice and singing is pre sumably trained in the dilferentiation in tonc(piality occasioned by changes in the action of the vocal mechanism. AVhen, however, we reflect that of the thousands of teachers in our public schools very few, indeed, have ever heard of voice-registers, and nmch less been accustomed to note distinctions in tone-timbre between them, the need of a detailed plan of procedure is seen. ^nisli one rcii-istor from aiiotlier. Tliero is no vot'ul triuisitioii so iiiiirked as tlic {•liaii<;e from thick to thin rciristiT in the chihl-voice, unless it l»e tlie chani^^e from tlie chest to the head or falsetto in the man's voice. Suppose we take a class of say twelve from the fourth year aveiMi^imr nine years of a<i;e. (iive them the pitch of C. stoptliem and ask them tosinu'that, and the two t(»nes ah<!\'e t'< /'_'/ ■""[ft^'J- The chani^t' in tone will he (piite appai'cnt. The torn; w^vA. in ascendiii;:; the .-cale of (', sim;ini;- haidly, will he reed\\ thick and hai'sh — the thick retrister. The tone Upon E first liuu with full strength of voice and then the octave lightly, or have them sing G second line, first softly and then loudly, or, again, let them ascend the scale of E singing as light a tone as possible, and then descend singing as loud as they can. In each case the change from thick to thin voice, or vice versa, will be illustrated ; and in singing the scale of E as suggested, the break of voice a little highe)' or lower in individual cases will be noticed. It is (\|uite possible that some members ()f the class may nse the thick voice on each tone of tbe descending scale beginning with the highest. Care must always be taken that in singing softly the mouth be well opened. The tendency will l)e to close it wlien re(]uired to sing lightly, but the tone, then, will be nothing but a humming noise. It may as well be said here that a great deal of future trouble and labor nuiy be avoided, if, from the first, ])Upils are taught to kec}) tlie mouth fairly well o])ened, and the lips su!Hcie;itly apart to [)e!'mit tlie free emission of tone. Let the lower jaw have a loose hinge, so to speak. It is well enough to ])(»iiit <»ut also that wIrmi tlie lower jaw drops, tlu' toii;^MU' u'ocs down with it, and should remain exteiitjed alonir the floor of the mouth with the ti}) against tiie teeth while vowel-sounds are suiii:;. There are many other ways than tho>e al^•eady suggested, in which the distinction hctween the reiri>ters may he shown Let tiie whole cla^s siii^ softly, and tiicii iiie next lower tone or tones loudly. The thick ([uality will he heard ea.-ily eiioUi^h. ( )r from the iMom select a pupil, one of the cla>s who ii.i-. in the phraseology of rile x'hoojrooiu, a i;do(l voice, to siiii;the >cale of I) a>cendinu^ and doceiidini:-. If the j)Uj»il he Hot timid, and the kind I'efcri'cil to ai'e not u>nall\\ and if joud .-in^in::' lias heen cu>toiiiMi'y. the tone will he coar.-e and reedy throuii'liouf. Now let another pupil who has what i.- called a li^'lit \'oice. and who daily sits niode>tlv in the ^hade of his hoi.-tci'ou> hrother. .^in-r the >;'me scale. The U)\iv in all lik"lilMi->j notes. Take the scale of E now and have eacli pupil in the room sing it alone. There may certainly be some who cannot sing the scale, and if the daily singing has been harsh, the number may be large, but postponing the consideration of these so-called monotones and directing the attention wholly to tlie quality or timbre of tone used by the different j)U})ils, it may be observed that some use tlie thick voice only, some use the thin voice, others break from the thick voice into the thin at one pitch as tliey ascend, and from the thin to thick voice at a lower pitcli as they descend; and if rccjnired to sing again, may perhaps pass from one voice to the other at different ])itches. Others again may exlii])it a blending of the two voices at cei-tain ])itches. In fact, unless the degree of j)ower is suddenly changed, a break from tlie thick tojie upon one note to the thin tone upon the next note or vice versa seldom ficeurs. period wlicn the voice cliaiigcs, only the break will occur lower with older pupils. Suppose, now, the teacher has obtained a tolerably clear idea of the dilTerences between the registers ; she should then arouse a perception of tone-quality in her pupils. Let the beauty of soft, light tone iis contrasted with loud, harsh tone be once clearly demonstrated to a class, and the interest and best efforts of every girl or boy who has the germ of music witliin them will be enlisted. Those who grumble because they may not sing out good and loud may be disregarded, and with a clear conscience. The future will most likely reveal such incipient lovers of noisy music as j>()unders of drums and blowers of brass. Select now a number of the class who upon trial have been found to have light, clear voices and who are not prone to shout. Let them sing use of the thin register to tlie h)west note. Let them now sing up and (h)\vn the scale several times, observing the same cantioTi when notes below C or B are sung, and also insisting that no push be given to the u})})er notes. Xow, first excusing monotones, let the other pupils in tlie room sing first down the scale and then up, imitating the (juality and softness of tone of the picked class. Recollect, you are asking something of your pupils which it is perfectly easy for them to do. It may be that the strength of well-formed habits stands opposed to the change, but, on the other hand, every musical instinct latent, or partly .iwakened, is becoming alert and proving the truth of your teaching better and faster than can any finespun reasoning. Illustrate the diiference in tone-(\|uality between the thick and thin register as often as it is necessary, to show your pupils what you wish to avoid and how you wish them to sing. When in doubt whether or not the thin quality is 1)eing sum;:, re([uire softer singing until you are sure. It is better to err upon the side of soft singing than to tako any chances, In time teacliors will becoino quick to detect tlie chaiii^e in rci^istor, and in time also the ^)r.{)ils wiio arc trained to sing in the thin voice will yield to the force of good hal)it, as they once did to had hahit, and seldom otiend by too loud or too harsh tone. The inquiry may naturally have arisen ere this: Are syllables, i. e., <lo^ re, mi, etc., to be used, or the vowel-sounds ? It is immaterial from the standpoint of tone-production, whether cither or both are used. Until children are thoroughly accustomed to sing softly, they will be ke[)t upon the thin register more easily when singing with a vowel-sound, than when using the syllables. Tlie reason is that the articulation of the initial consonants of the syllables re(piires consi(leral»le movement of the organs of speech, viz., the tongue, lips, etc., and these movements are accom[)anied by a continually-increasing outru.-li of air from the lungs, occasioning a corre.-poiidiiig increase in the volume of sound. Adult Voices show the same tendency to increase the volume of tone wheti lirst applying Words to a passage practiced pianissimo with a vowel-sound. It is advisable then losing scales and drill upon them with a vowel-sound, and to recur to the same drill for a corrective, when a tendency to use the thick voice in singing note exercises appears. Scale drill may he carried on as follows : If the scales are written upon a blackboard staff, tliey may from <lay to day l)e in different keys. It is a very easy matter to extend the scale neither al)ovenor below the ])itches within which it is desired to conline the voice. For cxam])le, the scale of E or F may be written complete, that of G as follows : and so on. Xow let the teacher witli a jxjinter direct the singing <»f the class upoji the selected scale in such a manner as to secure the desired result in tone, and incidentally a familiarity with })itch relations, etc. Of course, if chart.are useil the trouble of writinu' scales is savi'd. onlv it is advised that the notes Kiui;- outside the prescril)tHl compass hi' omitted in the lower i^nides entirely, and in the npper until the huhit of i^oot'i tone is estahlished, when, of course, the tones may i)e carried helow E with safety. The extent and variety of vocal drill which can be <fiven witli a poiiiti'r and a scale of notes is wonderful; hut iiothiiiir more need be now sugi:;ested, than tliose exercises which are j)eculiarly intended to secure u'ood tone, and tix ijood vocal habits, althou;L:li it must be evident that all such di'iil is veiw far-rea(;hint:; in its etYects. for example. bet the teacher, after the pitcL of the keynote is i^iven to the cla.-s. j)]ace the l>ointei- upon 1'", and slowly moving' it from note to note, a>c(iid and descend the scale, the class ^in^iui,^ a continuous tone U[)on some vowel, o b)r instance. The pointei" should be jiassed from note to note in >uch a manner that the eye can easily follow it. If the notes ai'e indicati'd to the cla>s b\- a scries of dabs at the chart or bJackboard, the pointer eacli time being carried away from the note several inches, and then aimed at the next note and so on, the eye becomes weary in trying to follow its movements, and the mental energy of the pupils, which should be concentrated upon tone, is wasted in watching the gyrations of the pointer. If, on the other hand, the pointer is made to glide from note to note, passing very quickly over intervening spaces, then the eye is not wearied in trying to follow it. These directions may seem pretty trivial, but practical experience has proved their importance. The vowel o is suggested because it has been found easier to secure the use of the liead-register with this vowel than with ah, wlien it is sought to break up the habit of singing loudly and coarsely. The term continuous tone used to describe the style of singing desired is meant literally. If the class in this scale-drill all stop and take breath at the same time, making frequent breaks in the continuity of the tone, there will be found with each new attack a tendency to increase in vfjlume of sound. For certain reasons. wliich will 1)0 ex])l!iincd in the cluipter on hreathnianagenicnt, tlic uttack of tone will boconio more and more explosive, deinandiniji^ constant, repression. This irritating tendency may, in a short time, he almost entirely overcome, if, instead (»f letting the class take hreath and attack sinndtaneously, each 2)upil is told to take hreath oidy when he or she is ohligcd to, and then at once and softly to join again with the others. This will eifect the continuous tone, useful not alone as a corrective for the tendencies to loud singing, hut also to estahlish good hreathinghahits. The exercise already suggested is slow singing or rapid singing of the scale with the vowel o softly, and with continuous tones. Other sim[)le exercises are obtained by repetitions of the following exercise figures at jiigher or lower ])itcheg tliroughout an entire scale, or parts of a scale, ascending and descending progressively: The next figure, iii which the voice ascends or descends four tones at each progressive repetition, has a different rhytlnn. ]ii the illii>rratioii which folhtws, in tlu( key of r» tiat, it is shown liow the exerci.-es may he simu", heijinnin<j,' iij>on tlie keynote, and kee];ing within the Voice-c(Mnj)ass. 'riie.-e t'.xei'cix'S are, to l)i' suni;' Mitli \'owelsonnds, >ot'tlv. foni' measures N\-itli one i)reatli, if ]io>-i!)le, and in .-ti'ict tinie. ( )n]y .-o many of tlie.-e tone-^iToups mav he su iii;- in any one >cale, as He williin llie e\t ri-nies iif jiitcli >:'t foi- the ;:i'ade, hut if (HlTei-ent scah's and upward and downward extensions of the same be used, then all possible combinations oi tones in the major scale may be sung, that is, these exercise iigures may upon a piano be repeated seven times in ajiy key, in phrases of four measures each, botli ascending and descending^ but, owing to the limitations of the vocal conipass, only a certain number of ascending or descending j)lirases can be sung in any one key. While it is suggested that drill upon these musical figures or groups of tones may be given from scales, the teacher tracing out the tones with a pointer with a rhythmical movement, yet it is still better to practice these groups ojsome of them from memory, the teacher keepmg time for and directing the class. Pages of musical phrases ada])ted to vocal drill might be given, but to what end except to produce confusion. Our greatest singers use but few exercises to keep their voices in good condition, but they })ractice them very often. Note. — The directions {.jiven are for rooms in wliich the teacher has only a pitch pipe or tuniiiff forii to get pitch from. If there is a i)iano tlie drill work for tone will be conducted a little differently. The exorcises sn<;i^ested are intended for daily pnu'tice, and the fewer in ininiher and simpler in form they are, the better will he the results in tone. This vocal drill which should ])recede or he^in the daily music lesson must not he for over live minutt's at most. Half of that time is enough, if it he sj)cnt in sin:j:;ini;, and not frittered away in useless talk, and (questions and answei's. A j»ractical aj)[)licati(jn of the vocal drill is to he uuule to the note-sini^iui; from the hook and chart, and to the school rej)ertoire of son::;s. The ])]irascs voice-culture, voice-trainini;, V(>ice-dcveloj)ment, etc., have ])een avoided in ti-eatini; the suhjcct of childreirs voices, he(•au>ci of po>>ihK; mi.-appiH'licnsion of tlieir intc'ndi'(l meaning. The terms are not, of course, inapplicahle to cliildren's voices, hut tliey nuist (•oii\cy (\|uire a dincrent signiticance tlian they do when aj)plied to the adult voice. In each -ca>e, the end of voice-culture is the formation of coi'rect vocal hahits; hut it would sct'm, that while it is po<>ihlu to develop the adult voice very consitk-rahly in power, range and llexi- bility, we ought, in dealing with children's voices, to adopt those methods whicli will protect weak and growing organs. The aim is not more power, but beauty and purity ratlior. It should not be inferred tliat beauty of tone is not equally the aim in culture of the adult voice, but in that case it is consistent with develo})uient of strength and brilliancy of voice, while with young children it is not. If tlie tone is clear, beautiful, well poised, and under the singer's control, then the training is along safe lines. If the tone is bad, harsh, pinched or throaty, then the training is along unsafe lines. When the parts act harmoniously together, and there is a proper and nornuil adjustment of all the organs concerned in the production of tone, the result is good. Bad tone follows from the ill- adjustment of the parts concerned in voice ]>i'odnction. It is the office of the tea(her to cori'cct this ill-adjustment and bring about a ]>ei'fect, or nearly ])crfect functional action. The teachei- must judge of the proper or improper action of ihe pai'ts concerned in tone production l)y the sense of heai'ing. Xo accumulation of scientitic knowledire can take the place of ii careful and alert ciitical (aciiltv in training; \oice. Tone C(>lor must u'uide the sehool teacher in (leterininini^ i-ci^ister as it does the [)i-ot"essional voice ti'aiiier. Hut we can also call the mental percept ions of the child to our aid, and will find a more lively sense of disci'iminatioii in tone (juality than the avei'au'e adult shows. We can encoiii-ai;e the iri'owth of hi^h ideals of tone heauty. We can cultivate nice discrimination. We can, in short, use music in our schools not to didl, hut t(» (piicken, the inusical sensibilities of childhood. "^ I ^HERE is the greatest diversity of opinion upon tliis snbjcct among those who have any opinion at all. It might be supposed that, among the thousands of educators who are interested in school music and in the singing of children generally, many might l)e found who have given the sul)ject careful attention, hut such does not appear to be the case. If we consult the musical literature published for children, the prevalence of songs suited to the contralto voice is noticeable, indicating apparently that the compass of infant voices at least is about the same as that of the adult contralto. If there is any generally recognized theory upon the subject, it would seem to 1)0 this; l)ut from a physiological standpoint the voices of children are totally unlike the wonum contralto, and especially is this true of children of from six U) eight years of age whose songs are usually written so low in range. An error, started any- wlien; or iit any tiiiic, of theory or of practice, if it once hecoiiie iiicorj)orutiHl into the literature of a sultji'ct, is liahk' to he frecjuently copied, and enjoy a lonii; and usck'ss life. So with this treatment of tlie chilil-voice. The error is in supposini^ that it consists of a limited number of quite low tones. It has its origin in the sole use of the so-called chest-voice of the child, and when the evident strain under which a child of six or seven years lahors to sin;^- up is ol)S('i'V(_'d, the conclusion seems safe tliat tlicy cannot sini:; hii^h. While, on the other hainl. they manai;-e with ap[)arent ease t<; siui:; down even as low as "^riiis Conception has in divers ways so imheddiMl itself into th(! musical literatui'c foi' little cliiMi'eii, that all etforts to uproot it have S( fai- lieeii appai-ently futile. There are, howe\ei\ ver\' many supervi>oi's of school music, and the numhei- is ^i-ow iiii^-. who haxc i-ecotrni/.ed that this treatment of little children's Voices is a \(ical harhai'itv, and the device of pitcliiiiii: soiiiifs liio-hor tliaii they are written to overcome tlie difficulty is more eommou tliau miii'lit l»e supposed. Tliei'e cjui be no douhr tliat in a shoi-t time tli(> pi'actiee of carrviuii^ tlie tones of little children tliri'e aiui four notes l)elo\v tlie fii'st line <tf the staff will not be tolerated. The common, even univei'sal. tendency of primary classes to drop in j)itch when ^inging with the u>ual thick tone iiii^ht show anyone that the V()ice was hciu^- used in an abnormal manner. I''urrhei'moi'e. the intonation of childiX'ii of any ai;'e i> ^onic-thinu' horrihle wlien the thick Voice is u>ed. Kxcii carefully-selected and traim^d boy choi'i-tt'rs. if they use this >oice. are fi"e(\|uenfly olf tlie key even when supported by men's \dices and the oi'^an. So in addition to other I'ea^oiis foi- nsin^- the thin I'l'u'ister may be added this, that habits of faulty intonation are surely fo>tei'e(l by the use of the thick vtjice. Picture to yourself the shoi-t. thin, weak vocal bands of a child of >i\ oi- seven years attaclu'd to cartilauiiiou.- walls >o de\did of riu'idity that in that dreaded di>ease of childhood — ci'oup — they cftcii (•<>ll:ii)st'. That is not an in>truiiiciitfor tin- j)f(.(liicti()n of toiu's in the conti alto coin [•ass. No Wonder tlie j)itrli is \va\ ci-iiiLi-. It infant clasH-s ai-c to >iii^ witli the n>ual tom-s, tlu' coninioii aiKicc to make the >ini:iiiu-t'\t-'r('i>e short is extremely jiKJicious. It Would he hetter to omit it. The intimation tliat the last word can now Insaid on thi> >iil>ieer is not for a m(^nient intemleil, lait expei'ieiice has :;;i\en somi! tolerahh' >afe hints ill refereiiee to tlie compass of the childvoi(H' in the thin rei^i.-ter at the a^^'cs mentioned, ami it is ad\i>ed never to carry the com](a-> lowei than l-", tir>t line, nor lii^'her than !■' filth line of the .-taif. and the iijiper extreme mii>t he sung s],iariii;^ly. d"he ea>ie>t tones He frc^m Ia»ini;- iiitw to children who ran::-e in ai;e from nine to ejexcii year>, who are found in the foui'th ami til'th year- of schooldil'e. it ma\' he ohser\'ed that there i-nuiica marki-d increa-e in the evenness and firmness of their tones. It is quite possible, especially at the age of about eleven years, to extent the compass to G above the staff and to D or C below ; but if it does no liarm, it serves no particular good end either, and unless care is taken, the children will })ush the liighest tones. All of the necessary music drill can 1)6 kept within the suggested range, and it is just as well to keep on the safe side. Then again, the extremes in age between children of the same class grow farther a[)art as we ascend in grade, and the compass must be kept within the vocal poM'ers of the youngest, and, from a voice-standpoint, weakest pupils. Protect the voice, and nature will attend to its develo})meiit. From the time children pass the age of twelve years on to the period of puberty, the child-voice is at its best, and if the use of the thin registei' has been faithfully adhered to in the lower grades, the singing-tone will now lie both j)iiif and brilliant. It will be found not at all dillicult to carry the same voice as low or lower than middle C without any peiceptible cli:uige in tonequality, and G above the staff will be sung with absolute ease. How iiuieli hi^licM-, if any, the compass may be canied is open to (liscussioii. It is not at all necessary in scIidoI music to i(o any higher, for, even where it is deemed best to i-aise the pitch of the sonir or exercise to avoid too low tones, the })itcli of the liiirhest note will seldom be above (x— space above. . practice, us high even as and although that is a ])retty altitudinous pitch, tliere ai'e very few choir-boys who, when taught to brt'utlie {)ropei-ly, etc., will not take it oc(■a>ionally with perfect ease. The head-register, ('\t'n in Woman's voice, is ca[)al)le of great exl);insioii, if good habits of tone-})roduction are followed. Ihit again it is well to be on the safe side; and ciioii'-boys. wlio ai"e selected beeaus<; tlicv liavo good vocal organs, and who are di-jllfd fur more than school cldldren, are hardly u ci'itci'ion to go by. can be pushed and forced. Good judgment must be exercised in controlling the power of voice, or children will strain the vocal mechanism in trying to outsing each other on hi(jJi tones. The (piostion, IIow higli may ])oys or girls sing who have passed twelve years of age and whose voices show no.signs of break, is not so very important after all, for if they have l)ecn well ti'ained in soft tone, no danger of vocal strain need be feared even if an occasional high A or n Hat is struck. The reason for the ease with which children sing the high liead-tones is fouiul in the structure of the vocal bands. They are tJiui. (Jonsequently, there is, compared to the entire substance of the vocal bands, a larger portion jiroportionatcly set in viltration than for the production of the head-t(jne in wonia'Ts vcuce. And when the child-voice is so used that no strain of the laryngeal structure is occar-ioned, that is, when the vocal ligaments nre exercised in a normal manner, it. cannot but happen that the muscles controlliiiu- the \-ocal bands will increase in strenirth, and that the bands them elasticity. The sufj^gestioiis made in regard to tlie compiiss of voice are, be it said, simply suggestions based on experimental teaching and are such as it is believed may be followed with safety in school singing. If they do not square M'ith the music (jf l)()(tks and c^iarts, why, as before said, it is a very him pie matter to give a higher key for any exiircisc, tlian the one in which it is written, A supervisor, by marking the exercises in tlie desk c()[)y, can ensure the use of the key he desires. If it is objected that the tones then sung will not r('j)resent the real [)itch of the written notes, wliy tliat is at once admitted, AVhat tlien? The idea of teaching a!)so]ute pitch is a chimera. Pianos are not alike in })iteh, neither are tuning-forks. ('lasses will often f(ir one cause ur another end a half tone or a tout! lower than they began even if the pitch as written is given. It may not lie (h'sii'ahle to sing in one key music tliiit is read in another, b'at it certainly is less objectioimble in every way than is an nnsafe use of tlie voice. The correct use of the voice must transcend all considerations in vocal music, and no sort of practice which misuses the vocal oigans can be excused Cor a moment. /^^NE way to secure i^ood position is to re^~"^ quire tlie ])Uj)ils to stand. Unless the 8ingini;-})eriod directly follows a recess, or the drill in physical exercises, the ])U])ils will wel come tlie o])})ortunity. As soon as standing hecomes irksome resume the seats. \o further direction in regard to sitting position is necessary than that the body sliould he lield not stiffly, hut I'asily erect and self-supporting, resting neither uj)on the hack of chair nor uj)on the desk in front. A douhled-up, cranip('(l position is, of course, all wrong, and niay he avoided if the ])upils are permitted to alternate hetween sitting and ijtanding positions; hut, if re([uii'ed to sit as suggested for too long a time, tlu^ rule will soon '• he honored iimre in the hreach than in the observance. " This brings us to tlie con sidcration of pends iniicli upon position. Thd breath is the motive power of tlie voice in speech or song, and the fundamental inipuftance of managing it ariglit lias been understood )\|y every tcaclier of voice since the time of Porpura. How for singing purposes breath shall be taken, how exhaled, how managed in sliort, is not yet entirely settled and presumably never will be, for peo2)le are not born wise, and some never acquire wisdom, of whom a few teach music. Browne and Behnke, in " Voice, Song, and Speech," p. 138-142, describe the jjrocess of breathing as follows : "There are three %vays of carrying on the process of respiration, namely, midriff breathing, rib-breathing, and collar-bone ])reat]iing. These three ways are not wholly inde])endent of one another. They overlap or partly extend into one another. Nevertheless, they are sufficiently distinct and it is a general and convenient practice to give to eacli a separate name, according to the means by which it is chiefly called into existence. The com])ined forms of midriff and of rib-breathing constitute the right way, and collar-boiio breathing is totally wrong and vifious, and should not in a state of liealth be nuide under any circumstances. ♦ "When enlarging our chests ^ / the descent of the midriff, we inflate our lungft where they are largest and where consequently we can get the largest amount of air into them. When expanding our chests l)y raising the shoulders and collar-l)ones, we inflate the lungs where they are smallest and where, conse(\|uently, we get the smallest amount of air into theni.^ T/ie criterion of correct insjii rot ion is (oi increase <>f size of the ahdoinen. (UkJ the hnccr 2>'irt of the chest. W/ioeccr (/rates ill the (thdomen, and raises the upper part (f the chist hreatJos ■icronglij.''^ In normal breathing the body at inspiratii»n increases in girth at the waist, and the abilomeii nii'ves slightly outward as the viscera are forced downward by the; descent of the dia{)liragm. 'J'he (liajdira^m is a large nniscle which serves as a j)artition between the thoi'ax or chest-cavity and the alxlomen. When relaxed its middle portion is extended upward into the chestcavity, presenting a concave surface to {\\<\ al>- domen. At inspiration it contracts, descending so as to assume very nearly a plane figure. At expiration the process isrev^ersed, the diaphragm relaxes and the abdominal viscera, released from its pressure and forced by the abdominal muscles which contract as the diaphragm relaxes, moves upward and inward. This kind of breathing in which the muscular contraction of the diajihragm calls in operation atmospheric pressure, supplies the body, when tranquil, with nearly or quite enough air. When for any reason a larger quantity of air is demanded, it may be secured by raising the ribs, thereby increasing the chest-cavity. In singing, the breath must be managed so that the air passing through the larynx at expiration shall be set into vibration at the vocal bands. Expiration, then, which ordinarily occurs very quickly must be retarded by slowly relaxing the muscles which contract at ins])iration. At the same time the throat must be open, and the nmscles surrounding the resonance cavities relaxed to allow free movement of the sound-waves set up at the vocal bands. Any upward nioveineiit of tlic shoiiklors and chest at inspiration involving the contraction of many powerful inusck's of l)ack and neck will occasion a stitTl'nin<r of the throat, which prevents free vihratii)!! c»f the vocal hands and serionsly interferes with the ivsonance of tone. The conclusion of tiie whole matter is, that in singing we sliould take hreath exactly as in the ordinary (piiet resj)iration, and avoid any lifting of the shoulders. This is at least enough to say to a class of children upon the suhject. The means adopted in education should he as simj)le and direct as possihle. It will he found unnecessary to say very much ahout breathing in dealing with classes of children. In the first place, the moment the suhject is hroached and the direction ''take a good hreatli " or a similar one given, each child will draw up the v-he. t ami shouldt.'rs prepared for a mighty elT<»rt; while, if nothing is said ahout it, ])osition alone heing attended to, the hreathing will he all i-ight. And again, while adult singers for various rea.-ons, oue of wliieh may he the supp(tsition that the more energy put forth the better the tone, often present themselves to the voice-teaclier with a fine assortment of bad breatliing-liabits, children, on the contrary, are sent to school at so young an age that a little watchfulness on the part of the teacher only is necessary to avoid improper ways of taking breath and establish good habits. If young children, then, are not permitted to raise the Ghoulderfe, they will perforce breathe properly. It seems inadvisable also to give any instruction regarding the emission of air from the lungs in singing. None but cultivated singers, after long practice and tlirough a complete command of the nniscles concerned, can vocalize all the air at the vocal bands. The absolute purity of tone which is thus secured is a result that may or may not be reached in any particular case. It depends upon the mental and physical organization of the pupil as well as upon the method of the teacher. Exercises which are adapted to the formation of good breathing-habits are mucli more to the point in practical teaching than efforts at expla nation, Tlierefore, a few hints arc given, wliicli, it is lioped, may be of practical value, for it is very important that good breathing-habits 1>€ formed in school singing. Tlie change in structure which the larynx undergoes at ])u]'crty, demolishing as it does the boy-voice, and rendering of no avail the training of childhood in so far as it alTects the larynx, does not extend in its eiTects to the breathingapparatus. So, a habit of breath-management, good or bad, formed in school may continue through adult life. Special breathing-exercises are sometimes recoimnended, but their efficacy may be doubted, even if the length of time devoted to the nnisic les.st)n permits them. The inclination of pupils in such exercises is to raise the chest and fill the lungs too full of air. The result is too much air pressure at the vocal bands, and a stilTcningof throat and jaw muscles. The tone then will be loud ; in fact, strong pressure of air at the vocal bands is almost sure to force tliem into the fullest vibration; that is, into tlie thick register, an<l, as a result of contracted throat, the tone will be \|)inclied, or throaty. It teach good habits of breatliing as bad. This exercise may occasionally be given : The pupils first standing, shoulders well set, but with no pushing out of chest, ])lace hands at the waist so that the. movements of normal breathing may be felt. Now let the pu])ils take a little breath quicMij. The movement at the waist must be outward and downward, never inward, at inspiration. The breath may be held a few seconds by keeping the waist expanded — keeping an imaginary belt filled, for instance — and then let go by relaxing at the waist. If, however, there is any stiffening of the throat, as if it were thought to cork up the air in the lungs, the object of the exercise, iii so far as it relates to the formation of good breathing-habits suitable for easy vocalization, is defeated. Every teacher must use his judgment in this matter of breath-management in singing. If pu2)ils are, unguided, using correct, easy methods, tliere is then no need to interfere. If some are inclined to take too nnich breath and lift the shoulders, a few hints may put them on the right track. Lmul tiiiKjiny and JmuJ hreatldiKj-halnts go to(jeiher. If the first is desired, the hiiigs must work at full capacity, and Imrd blowing from tlu; lungs forces the voice. On the contrary, soft singing ^-n. motes <\|uiet habits of breathing; and, if the pressure of air at the larynx is moderate, soft tone is })ossible. If thin, soft singing alone be allowed, (juiet deep breathing will be ])ra(;ticed instinctively. The easy control of the muscles whose relaxation })crmits the exhalation of air from the lungs is, as already said, gained by their })ro{)er exer"ise in speaking and singing, for the same mechanism is called into operation in speech as in song. In childhood the hings can neither hold as much, nt)r retain it so long and easily as in adult life. There is no better way, perha])s, to acquire the ability to regulate the air-j>ressure at the vocal bands than by soft, sustained singing. Tlu! '•continuous tone" described in a preceding cbaptci-. sccuri'd in scale drill by letting each child breathe at will, is an excelli'nt exercise for develoj)ing good breathing-habits. As there it) no nervous tension whatever, each pupil will naturally sustain tone until the need of another breath is felt, when it will be taken quickly and the tone at once resumed. To sum u]) : Sit or stand in good position, the chest neither pushed out nor in a state of collapse. Avoid any, even the slightest, upward movement of the shoulders. Point out the movements at waist occurring at inspiration and at expiration if necessary, not otherwise. Let the breatli be taken quickly, not too mucli at a time, and as often as need be, and sing softly. Attack. The beginning of each tone is called attack. The common faults of attack in (•lass-sinirin<i' are sliding to the ])itcli instead of striking it ac curately, and beginning to sing with the mouth still closed, or only partly (>])oii. Wlien tlie attack presents the combined etTects of these two common habits, a quite reaHstic caterwaul is the result. mental iitteiition is tlio most iiifallihlo cure for slovenly habits of attack. It may be that tliere are in all schools a certain ])roportion of the pupils who have very weak and imperfi'ct vocal organs; in their cases, even good attention cannot overcome physical inability. In repose the vocal bands are separated to allow the free })assagc of air to and from the lungs. At ])honation the bands are drawn toward each other, meeting just as it commences. There need be no preliminary escape of air. Also the resonance cavities above should be open, that tlie vibrations generated at the vocal bands may find expansion and resonance. Tiie mouth and throat shc)uld then be o[)ened a moment before tone is attacked, when, if the jtitch to be sung is clearly ])ictured in the miiul, botli the "slide" and " hum " will be avoided. Heauty of tone implies absence ».)f disagreeable (jualitit's, and freedom from unpleasant sounds. Faulty toni's are called nasal, guttural, palatal, throaty, nudlle<l, and so on, the peculiar timbre of eacli sug<^estiiig the name. If the throat h relaxed, and if the soft parts of tlie vocal tube Ijiiig between the larynx and the teeth are kept out of the way, most of tlie disagreeable qualities of voice enumerated disappear. Certain requisites are necessary to good tone-formation. First, a movable lower jaw. It is astonishing that so many of young and old will, when they wish to open the mouth for song, try to keep it closed. Paradoxical as the statement is, it nevertheless describes a very common phenomenon — the " fixed jaw," it may be called. As soon as the teeth are parted slightly, the nuiscles of the face and neck which control the movement of the lower jaw contract, holding it in a fixed position, and iuciilentally tightening the muscles of the throat until the larynx is in a grip as of rubber bands. The mouth nuist not be held open as if the jaws were pried apart. It is opened by the relaxation of the closing muscles and should hang by its own weight, as it were. If tlieu the lower jaw drops easily, and with no acconqianying muscular contraction of face or throat, the tone struct it. These soft parts arc tlie tongue and the softpalate. The soft-palate is a structure which liangs from the posterior edge of the hardpalate. The uvula, the pillars of the })alate, and the tonsils are parts of the structure. The tongue which, when the mouth is closed, nearly tills it, should in vocalization lie as much out of the way as is possible. If the tip be pressed against the lower teeth and its sides upon the molars, it foi-ms a floor to the cavity of the mouth. If the tip turns toward the roof of the mouth, or if it is drawn back and uiuler, so as to arch the tongue, tone is seriously interfered with, while if the root of the tongue is drawn backward, the tone is shut in. Jf the soft-j)alate is not raised in singing, the tone is diverted into the cavities of the nose, and that color given to the tone called nasal. If the lower jaw is held too high, the tone is again foi'ccd tlii'ough the nose. A nasal (juality can be modititMJ by oj>ening the mouth. Tho muffled voice is sometimes tlie result of the tongue's unruly behavior. The throaty, pinched voice, due to a stiff and pinched throat, will hardly appear if good conditions as regards position, breathing, soft tone, open mouth, etc., are maintained. The tone should not be swallowed nor, on the other hand, blown out of the mouth. It should be formed in the mouth and kept vibrating within it. When the right conditions are hit upon, the tone seems to sing itself. Whether soft or loud, the tone should fill the mouth, so to speak. It must now be remembered that beauty of tone improves along with growth of thought and feeling. Encourage discrimination in tonequality and help in any way advisable the growth of good ideals, and verily shalt thou be rewarded. VOWELS, CONSONANTS, AUTICULATION. OOrXD-VTBPtATTOXS gejierated at the larynx are moditied as to tlieir form, by the size and shaj>c of the resonating cavities of tlie nioiitli and pliarvnx, Throngh tlie movements of tlie soft-palate, tongue, lower jaw and lips, the shape and size of the month can, within certain limits, l)e changed at will. As every vowel-sonnd requires a peculiar form of the resonating cavity for its production, it will he easily understood tliat each vowel-sound of which the human voice is capable can be made by a proper adjustment of the movable parts of the vocal oi-gans. As all singing-tone is vocal oi' Vowel in its cliaract(>r, the production of the vai'ious \-owel-sounds takes ])recedence in tlie studv of vocal mu>ic. Just how much of this study can be carried on in school music will depend upon circnn.istances, the chief of which is the time assigned for music. It is very easy to buggi'>t that if the time given is not enough, that 1)5 longer lesson periods be demanded ; but it is quite probable that, owing to the pressure of elaborate courses of study, tlie recjuest would be seldom granted. It remains, then, for those in charge of school music to expedite their work bj means of simple and direct methods. Each division of the music work nmst bo carried so as to secure unity of result. The vocal drill, oral or written, will train the eye and ear for sight-singing, and the sight-singing be a practical application of correct vocal drill. The study and pi-acticc of the different vowelsounds must then jit in with the scheme of study. The practice of singing the vowels by name as, ^r, «^, /, o^ i/, is not to be recommended, as only one, namely '', stands for a single soundelement; nor is it probable that the results will justify extensive (h'ill upon the; more obscure vowel-elements, if the term may be applied to those Sounds which are diiferentiated only slightly from tht3 nioi'c })i'onounced vowelsounds. a lops nniiil)or are employed in sonjij. For, wliile it is (lesii'ul)le to t:;ive to each word and syllahle its coi'rect vowel-sound in sinij^ini:;, those which ire unfavorable to <z:ood tone are usually approximated to the iiound of those more favorable to Ljood tone. If too marked distinctions in the vowel-sounds are made hy the singer, the result is disai^reeahle; while if the voice })reserves a similar hue or tone-colur tlii"oui;hout, the elfect is pleasiiii::. The li>tenci" is unaware of tlu; sli^^ht deviations fiMiu the sj>oken vowel-sound wliich tlie sinu'er makes, that th(3 ie(piirements of tonal beauty may l>e met. It is aiixisabK; i;. vowel-practn't to avoid letters or symbdls V. nich I'epi'esent two sounds, an initial and a \anish ; ami to use simpU' vowe. t'leiiH'Ht^ in.-tead. The combiiiatioiis df dilh'i-ent elements repre-eiited by certain lettei's and diphtlmii^.-, may ea-ily be e.\plaine(l when they ap]iear in the Word.- .,f a xinu", if. indeed, the study of pliMiiio ha> ]\nf aliH^aily '-leared away all ditlieiill ies. stand which of the two sounds, tlie initial or the vanisli, is to bo sustained. In «, for instance, wliicli is eJi he, if the vanisli e is sustained in a word like day the effect is deh ee. The first sound should be sustained, and the vanish e be lieard only sliij^htly as the iiiontli })artly closes at the end of the tone. 1, again, which is equivalent to ah + e, is often sung by prolonging tlie e instead of the initial ah, as llr/ht — li-eet. O'ib'a compound sound d-\('jd, but the tendency to sing the first sound sliort and prolong the second is very slight usually. O, then, can be used to represent a sini])le element. U, which e({uals e-hoo, is best sung by making the initial sound short and the vanish the longer tone. It will thus 1)0 seen that of the five vowel names, a, e, ^, o, u, e only stands for one sound, though the two sounds of o are so closely allied that the vanish is often imperceptible. The sound of a in at is the most unfavorable sound for song in the language, and those extremely consistent singers who wish to use it can do so. needs no nonrisliiiiii^. Its roots are grown wide and deep; so imich so, tliat those wlio love it need not fetir that it will pine away and die, if it bears no fruit of song, but only that of speech. The sound of a will survive even if it is unused in song. It sliould in singing be broadened nearly to the sound of (th. in it), % (as in vV), c//, ah^ aa% 0 (as in go)^ oo. The V(»wel-element8 remaining are each so closely allied to some of those indicated that the attempt to dilferentiate them from tlie above in voWL'l-(]rill is hardly worth while. In fact, the use of 1 — / as in it — may be omitted if j)Upils have leai'ne(l to sing e with fair breadth of Sound, iind oo may be dropped in grades above the j)i-im;ii-y. It is the final sound of /7, as before said. This leaves live vowt;l-elements. E. Tliis vowel is often badly sung, and its form is none too fa\'(ii"ab]e to goo(l tune even when made as lar^-e as distinctness will allow. The lips must be drawn a little away from the teeth as in a smile, hut doiiH overdo it^ and the teeth slightly parted. The lips should not be drawn back, exposing the teeth and gums, nor should they be contracted and })resscd against the teeth. In e and in all vowel singing the lips sliould he relaxed, not contracted, and kept about as far from tlie t(!cth as they are in repose. If the opening of the mouth, that is, if the cavity back of the teeth is ke])t too small and narrow, the tone will l)e nasal and twangy. The mouth nmst l)e opened enough to pci'init purity of tone and free emission. The sound should verge toward i in it. K or KIT. Tliis is the sound of e in tlie word get. It is also ihe initial sound of tlie vowel a or long a. It is tru(! that this sound is not usually so given, t)ut if a is sung with this sound as its initial ound, an<l the one to he ])rolongt'(1, the very hest vocal results can ])e obtained Tlu' >'"\v(>) d is more often poorly sung than otlierwnse. Thi.s is, perhaps, for the reason tluit comparatively few singers recognize that long a stands for two sounds, and that the first, which may be s])elled i/i, can he sung with large form and j)laced well forward in the mouth, wlnle the second sound P is small in form, and not arlapted to the finest tone-effects. In singing this element, tlic jaw should droj) much lower than for I and nearly as low as for ah. A or AIT. This is the tone universally accepted as the best for voicc-(ie\cl(>iiiiu'nr ; hut in scliool-singiiiL( it is not jM'niii»ilil(' to use tlic voice except in the lightest manner, thci'efore purity of tone nin>t cniitent our amhitioiis; [)ower can come latci- in life. The mouth opens widely for this tone and the whole throat is expanded. A or A W. This element is I'ormcil very nnich like ah. It is (//i l)i-oadene<l ;i little. The jaw drops to a lower point and the niouth-eavity deepens, while at the same time the extension from side to side narrows a little. 0 and 00. These sounds are better adapted to securing tlie use of the thin voice, where pupils have heen accustomed to the use of the tliick voice, tlian any otlier vowel-element. The month is well opened buck of the li})s, which should not 1)0 puckered as if to whistle, but relaxed instead. In actual practice there may be observed a tendency, more or less marked, but pretty sure to manifest itself if practice on one sound is con tinned too loni^ at a time, to deviate from any one toward some other vowel-element, as I to e, eh to I, ah to er or er or iih, ato to uh, o to oo. If this tendency to deviate from the right tone be permitted- the most slovenly habits will be formed, and ah. distinctions in vowel-sound disappear. Vowel-practice had better be (nutted from class- won: 'unless carefully and ccnscientiously taught. If the course of music eml)races drill upon scales, vowel-practice may be Micorporated into the course easily. For instance, the drill outlined upon [) 70 may one day be given with e for a few moments, then with j. On another day the drill may l)c upon a/i, followed by e/t, and so on. It is unnecessary to particularizeKvery teacher will at once see how to apply practically vowel-singing to his music course. The exercises and songs may be sung with vowelsounds. Nearly all books advise the use of la, '(», etc., t>i vocal exercises; but while that method of singing is unobjectionable, the vocalization (»f solfegi^ii, it may be observed, is established by the sanction of time and the experience of thousands of voice-trainers the world over. The advantages which ilow from vt)calizing exercises and songs on a single vowel-sound are too many to be described in a word. No su))ervist>r or tcaclu'r of nnisic can afford t. ■ use ^/(>, r'', ////', i'\chi>ivi'ly. Anothei' class (>f exercises is tiow suggested whi;'h may \tv sung upon one bi-cath. They will be found e.-oecially uilapttMl to dexelop flexihilitv an;] a i-cady ad ju-riiiciit t»f the movjible j)arts of the \(>cai tube to the positions suiti'fl to the foi'tnation of the dilTereiit vowel-sounds If llii-ce .-ouiids arc u>ed as liei-e i;-i\-en, the\- nmst lie -^UMg ipiire slow ly, the change from one sound to the next being made by a quick, easy change of position of tlie jaw, tongue, etc., but without interrupting the continuity of tlic tone. Sufficient pause to oI)tain a new breath must be made at the end of each group, and the moutli opened properly for tlie production of the first sound of the next group before it is at tacked. The tune should be quite slow and as in illustration, or tlie breath M'ill not be used, and at each succeedmg group of tones tlie lungs will become too full of air. The attack will then be explosive, and the tone too loud, if, indeed, the effort to control die breath does not contract and pinch the rliroat. It will l>e observed that a eertaiii system of arraiii!:eiiieiit of the vowel-eleiiu-nts is followiMl. First, there are live u'l-oiips, of which o is thd lirst and last sound, the others heiui,^ ])laei'(l between. Then c is the first tont' with >' as the second, the other sounds in turn endini;- the u'roup. Next (f/i is tlie st'cond s(»und, then r/t, /, no and a/i niij::ht he used as the second vowcl-elenient, niakin<r thii'ty-iivc cond)inations with o as the iiutial souiul of each ^-rouj). The same mimher of combinations can be made witli (f/i as the fir>t titne, and so on witli each of the seven vowclelemcnts. Sixt<'cn of these a'roujjs, chan<j;cd from time t(t time as mav lie de>ired, can be writren upon the blackboard and suui;- by the class in the wav set forth, the teacher meanwhile ket'pinu- time for and dii-ectiiiu' 'he class. It may be oi»er\-ed in this connection, that, as the voice a,-'-eiids in pitch, there is a teiidencv to IiIcikI the \ai"ious \o\vej-sounds into one sound. .\s the tiiues i;-i'o\v Iii^^-Jiei- the soundwaxes are focused at higher points ujxiii the hai-d-palale, the soundiuir-board of the i-esonance cavities, and more difficulty is experienced in moulding these sound-waves into the forms characteristic of the diiferent vowel-elements. As the parts concerned in tone-formation gain in llexil)ilitj, the result appeal's in the ease with which the alterations in shape of the resonance tube are made at higher pitches. Fads and devices which divert attention from the subject and i-etard rather than accelerate the j)r()gress of ])upils are common enough in schools, l)ut the following sim})le illustrations of diiferent vowel-forms niav be found useful: The base line i-epresents the floor or base of the month-cavity, and tiie arch, the height and width of tlie moutli for each sound; the de])th is not indicated. The width of the mouth from side to side is i-cpresented as j:;rc'atcst in <". / and ch, while tl;e lieii^lit is <;reater in ah and am^ o is pictured as nearly round, and oo the same, only small. It is not contended that these diagi-ams picture the actual form assumed by the resonance cavities very accurately. The various positions which tiie tongue and the soft-inviate assume are not shown at all, nor, perhaps, is it necessary; foi- it' the pu{)il is taught to dro]) the lower jaw to the riglit position for each sound, and to keep the tongue ])rone in the mouth, a mental picture of each tone will be formed, and the thought will regulate the action. When the ]Mipil can think the sound desii-ed, tiie conditions for its formation will be met by the vocal oi-gans. The usefulness of diagi'ams will then cease. ''Consonants ai-e the bones of speech. i>y means of consonants we articulate our woi'ds; that is. wo give tlicm joints. ^Vc utter vowels, we articulate (-(insoiiants. If we utter a single vowel-sound and interrupt it by a consonant, we get an articulation. Consonants, tlien, not only give speech its articulation or joints, but they help words to stand and have form, just as a skeleton keeps the animal from falling into a shapeless mass of flesh ; therefore, consonants are the bones of sjuK'ch. The consonant is the distinguishing element of human speech. INIan has been dehned in various ways according to various attributes, functions and habits. lie might well be called the consonant-using animal. He alone of all animals uses consonants. ft is the consonant which makes the chief (Hll'crc.'iice between the cries of beasts and the speech of man." — liicliard (J rant WJiltc. Consonants are not to be sung. The eft'ort so common among singers to j)roiiounce. by sustaining consonant sounds, is entirely misdii'ecte!. J/, n ami tkj. which are made by shutting off the esca])e of the air-current at eitiier the lips oithe hard-palate, and so forcing it tlirougli tlie nose, are often sustained to the detriment ot beauty of tone and (dear pronnnciation as \\(A\. 'v^i:^ tlio air-cnrront, wliotlier vibratory or not, at (•(M'taiii j)( tints. Tlio interruptions arc made by tlie meetini; of the lips witli eacli other or witli the teeth, l)y tlie tonLjnc with the teetli or liardpalate, an<l tlie root of the tonij^ue with the soft])alate. The interrui)tion may be complete, as in /> or f, or only jiartial, as in f/i. The sound of the consonai't results from the sli<i;ht exjtlosion or pult" which follows the recoil of the movable ])arts from the j)oint of contact. All consonants may for sin^inii; j)urposes l)e considered as [)rece(liiiii'or followinu' some vowelsound. If precediiiii', then after the soun<l is made the vocal organs nuist be adjusted at oiu'c foi- the propel' foi'iuatioii of thesucceediiu:; vowel. If the consonant sound follows a vowel-tone, the niovciiieiit of the vocal or<4'ans to the iiiterniptiiii;- ])i»int must be (piick and vocalization at once cease; for if the \-owel-sound is jtrolonijed after the production of the consonant, tlii' elVcct will be an added syllable to the word as <if-<(t-< i\ iij>-itj)-ji(ih^ '■tc. The iiioNcments of the ori;-an> >i speech for i)otli contact and reroil must bt' lation than in spoken language. Slovenly habits of articulation in speech will reappear in song, and the converse is also true. The study and practice of phonics, which is now general in schools, is of the highest practical importance in singing, as well as in reading or speaking. As consonant sounds cannot be sung, they are best taught in spoken language. The application of the knowledge and skill thus gained is readily a])plied to the pronunciation of words in singing. If the vowel-elements have been carefully practiced in vocalizes, there will be little effort required to secure the correct formation of all the vowel-sounds of words. The nasal twang nmst, however, be ruthlessly suppressed. As before suggested, this will frefpiently a])})ear in words coiitaining the sound of (I, as in at, past, fad, etc. It is recommended that such words be sung Avith a as in fatJier, or if not quite as broadly, at least approaching the sou 7 id of ah. iiess, and if tlie nioutli opens ncitlRT too nuicli nor too little for each vowel-son nd, words may 1k' snnii^ and understood while beauty of tone u not tiacriticed. MUTATION OF THE VOICE. " I ^IIE anatoniical and physiological changes which occur in the larynx at puberty have been described in the chapter on " Physiology of the Voice." It may be added that at this period the resonance cavities also undergo considerable alteration in size and form. As childhood is left behind the individual emerjjes. Diverijences in face, in form and in mental characteristics become emphasized. The traits of race and family are manifested and selfconsciousness becomes more acute. This period of development, bi-inging as it does so much disturl)ance to the vocal organs, is particularly inimical to singing; and yet public school music is expected to produce^ its most elaborate results in those grades where the pupils are just about to enter, or are passing through this period of raj)id growth and cliange. The singing in such grades may be discussed with reference lirst to tlie singing of girls and then to that of boys, The vocal organs of girls often develop so gradually in size, and with so little congestion of the laryngeal substance, that no aversion is manifested to singing. In other cases the intlatned condition of the vocal organs is shown by the hoarseness winch follows their use, and the huskiness of tiie singing-tone. The vijices of nearly all during the nnitation })eriod show more volume of tone on the lower tones and evidences of strain at the higher tones. It is a good plan to })ut girls who show throatweakness, characteristic of their age, upon that part which reipiires only a medium range of tones, and to repress all inclination to force and pusji tlie voice. The desire wliich girls often express to sing tlie u[)pcr soprano need not alfect the teacher to any great extent. A nmltitude of strong and constantly-shifting ambitions are thronging through their minds. Some M'ish to sing the highest ])art bccau>^ it seems to them to be the most prominent pai't ; some wish to sing it because they can i\o so with the least mental etl'ort, and so on. 'J'hese wliims and wishes must be treated tactfully, but if the teacher is sure that a certain course is Hglit, there is no alternati\'e but to carry it out, with as little friction as may be. Large voices, that is, voices that proceed from large resonance cavities, are often badly strained at this period of life l>y too loud and too high singing. It must not for a moment be forgotten tliat the age is a critical one for vocal effort, and a strain that the adult woman's voice will endure with apparent impunity may produce lasting evil effects on the voice of a girl of from fourteen to sixteen years of age. If the recjuirementsof the music are such that pitches above V, the tii'tn line (i clef, nnist lie occasionaL'y sung. let ine voices upon the jiart ein^ lightly. If some of the gii-ls are ])ut uji(tn the lower of rhi-ee jjai-ts, do not let them use the shest-vdice. which is just l)eginning to develo]). otherwise than lightly also. The boy's voice may ciiange from the so])i'an(t to a light bass ^'f eiuiit <>!• twelve tones in compass in a iev\- month.-, or the change may extend over two or tliree yeai's; that is, two or three years may elaj)>e after the first distinct break be- fore there is any certainty of vocal action in the newly-acquired compass. When the voice (•han<j^e.s ra])i(lly. all siui;ing should he stop])ed. Ileally, in .such cases, boys cannot sing even if they attempt to do so. They are so hoarse, and the ])itch alternates so uiu'X})ectedly between an "unearthly treble and a preternatural i)ass" that a boy can usually sing oidy in monotone, if, with courage proof against tlie ridicule occasioned l)y his uncontr<.»Ilablf \d('al antics, he trvs to join in. In those cases, wlieiH' the lai"vn\ undergoes a slow change in i:r<iwth. it is often possible for the boy to sing all through the period of change. The upj)er tones may be lo>t, while there is a corres[)onding gain of lower tones. This })rocess, in many cases, go(,'s on >lnwly and with so little active congestion of the iaiTUX that the voice changes fi'om soj»raiio to alto, and thence to tenoi' almost imper(H']»til»ly. \'oices which change in this way ott<'U become tenor, but not in\ariablv. The (jue^tioii now arises. Should tlmsc^ bovs who can >ing while the voice is bi-eakiiig be rei^uired to take [)art in school singing exercnse.- ? In Browne and Behnke's work, " Tlie CliildVoice, " to wliicli allusion has been made, there is given a resume of 1;")2 replies to the question : Have you ever known of boys being made to sing through the i)eriod of puberty, and, if so, with what result V of no conclusion. Seventy- nine say the experiment causes certain injury^ deterioration or ruin to the after voice, and of this number ten ol)serve that they have suffered disastrous eifects in their oivn j)e/\son. It will 1)0 noticed that only lifteen of those who ilive a positive oj)inion u}>on the suhject think that boys can sing through the })eriotl of break safely ; while seventy-nine are ])ositive that the result is unsafe. The other replies are vague. It must be remembered that many of the opinions are those of instructors in cathedral schools, where one or two rehearsals and a daily church service means a great deal of singing; while other answers come from choirmasters who re(piire of their boys e(pially hard work, though less in quantity. Every individual voice nnist be judged by itself, if such demands as choir-singing are made upon it; and, while there are some cases, as every choirmaster will probably agree, where no perceptible injury results from singing during the change, the rule is that even when ])ossible, it is very unsafe. JJut the daily time given to singing in schools is very short; the work bears no comparison with choir-siugiug. It might almost Ix- thought as necessary to forbid i-cadiug and talking during drill of fifteen or twenty minutes in singing. Certainly it is absurd to advocate entire nonuse of the voice at tliis period in either speech or song. It is ratlier correct to guard against its misuse. If boys have up to tliis time used only the thick register, they will in singing through the break intensify their bad hal>its; throatiness, harshness, nasality will become cln'onic. This would be bad enough, but each bad vocal habit results from the abnormal use of the vocal organs, and occasions hoarseness, chronic sore throat, catarrh, etc. It is quite customary in school music to assign the boys to the lower part, in part music. This practice contiimed from the time part-singing begins in the music course, compels the boys to use the thick register. As the larynx gains in firmness from year to year, they experience more and more difficulty with their u})per tones — those lying from F to (\ Having used only thc thick voice in all their scht^ol singing, they know of no other, and very likely consider the thin voice which they are now obliged to use in sim;- The rehic'tance of l)oys to siiii:; the sopi'ano would 1)0 aniusiiii; were it not, in the light of uttei-ly false training, so pitiful. School music i^ educational ; its sco]ie is coiitrollcnl hy those in charge. The ]>ul)lic expects gfiod educational, i-ather than show woik, and employs those to supei'vise and teach who are supj)ose(l to know what goetd educational woi'k is in N'ocal music. The su])po.-ition that children's voices can, owing to individual diffciences analogous to those existing among adults, he divided into alto and soprano voices, is erroneous; children can most assuredly sing in pai'ts, hut the (juality of tone which in the woman's voice is called alto oi' contralto cannot he secured for certain ])hysical reasons previously ex])lained ; and the use of the chest-tone, which icsemhles the adult woman's chest-xoice as a clarinet resemhles a viola, is wholl\- ohject ionahle. iiieiit of the boy's voice during the change is siniplitied ; the influence of good vocal habits will be felt; the vocal bands which have never been strained will respond when their condition admits of tone-production. The boy who has been accustomed to sing with an easy action of the vocal ligaments and with open thi'oat will at once become conscious of any unusual strain or wrong adjustment in the vocal oi'gans. If he has learned to sing well, he has also learned not to sing badly. The test to apply to the subject of boys' singing in school during the break may be: Can they sing without sti-ain or push ? Can they sing easily, or does it hurt? There is a certain amount of humi)ug in boys that must be allowed for, but it does not affect calculations as to their singing-powers more than upon their other abilities, if singing is well taught. The speaking-voice also indicates the state of the vocal organs, and shows the effect of the bi'eak sooner than does the singing- voice. If the tones in speech are steady in ])itch, singing is possible in all probability. If, on the contrary, the ppeaking-voieo is croaky and wavering, singing is tlifficMilt, if not impossible. As the object of the stiul}' of vocal music in the jmblic schools, in so far as it relates to the treatment of the voice, is to develop good vocal habits, not bad ones, it follows that if boys sing during the break it must be only upon those tones wliich lie within their compass at any time, and that the vocal organs must be used lightly, and without strain. In nearly every upper grade room tliere will be a percentage of boys whose voices are in a transition stage, some of wliom can sing and otiiers of whom cannot. It recjuires judgment and tact to liandle tliese voices, 1)ut if boys have sung as they should up to this jiei'iod, and have taken ])leasuie in it, the mutual good understanding between them ami their teacher need not be disturbed. They are likely to do their best. In this connection it should be said, that ically it may be doubted if the common })i'actice oi assigning all boys, whose voices show signs of breaking, to the bass part, is right. ai] part singing and liave never used other than the thick cliest voice, then, when the voice hegins to break up, it may be that tliey nnist sing bass or not sing at all. Boys trained in this way have never used the sopi-ano head register and so if they sing alto, it will be with the thick chest voice of boyhood, which will now be the upper tones of the developing man's voice. Singing alto at the mutation period in f/n's manner, strains the vocal bands beyond reason, and should not under any circmnstances be allowed. It nnist be understood then in what follows, that singing alto in this, the chest voice, either before or during the break, is unqualifiedly condemned. But we will suppose now that boys have been permitted to sing only in the head register, that they have been assigned to the ujiper part in part sinjiriuii:, for notwithstanding that usaire is to the contrary, this is what should be done. As has already been suggested the voices of girls change less, and at a younger age than do boys, and tlicy begin to show weight of tone and iiicroas(>d vt)lume, at an age when boys are at their best as PopniiKts. (lii-ls at this period slioiild sing tlie middle ami lower parts, hut it must he said in passing that much of tlu; nnisie contained in our text-hooks ranges too low in ])itch for them, or any voice except a low contralto or a tenor. They must not he jx^rmitted ♦^^o use their voices at full strength, ami special cai'c sliould he taken of those wiio at this age sliow hoarseness. With girls as with hoys, the change is accomparued with ]ieriods of gi-eat I'elaxation of the vocal ])ands, and during these j)eri()ds tlie singing toTie is either vei'v light, or very loud. Returning to the suhject of treatment of hoys' voices (luring inutatioii. and ])remising that they hav(^ sung only in the head voice during chiklli(.od, the (picstion arises whether they ai'c not in manv cases set to singing hass prcmatui'cly. It is ohvious that during this ]K'riod the voice is actually liro],' n. divided in two. The lower notes are produced in the chest or man's registei', wliiie iiioi'e or l(!ss of the hoy's xoice remains as upper tones. Tlie>e tones. ])y the way, never are lo>t. they renuiin as the falsetto or head voice of tiie num. Now the vibratory action of the vocal ligaments is much larger for the chest voice than for the head, or as we ordinarily call it, the falsetto. There is then no question that during mutation a boy can confine himself to the use of his old voice, or so much of it as is available at any time with very little strain. The tone will be light, in fact, during the active periods of laryngeal growth which characterize mutation, there will perhaps be no voice at all, owing to the congestion of the parts, but in the periods of rest separating the periods of growth, the vocal bands will respond. The compass of the head voice at this time varies largely, but it corresponds pretty closely to that of the second soprano, in three part exercises, or from C to C. If it ia attempted to carry the voice down it changes to the chest register uidess used very lightly. Without attempting then to lay down positive rules for treating a voice which consists of fragments of voices, the above suggestions are made in the hope that they may receive the consideration of teachers and musicians. TTIE ALTO VOICE IN MALE CHOIRS. '' I ^IIE sngi^estions of the ]")receding chapters "■ are addressed directly to those who teach vocal music in j)ul)lic or private schools, but the general principles and rules are equally applicable to the training of soprano choir boys. The results in beauty and power of tone which may be obtained fi-oin cai-efully selected choir boys can seldom be equalled in the school-room, lii'st, because training is re(\|uired to develop voices in sti-ength and \|)urity of tone, and the time devoted generally to sciiool singing, one hour a week possibly, is no moi'o than that given to a single i-chearsal of choristei's. appear almost entirely when pupils are trained to use the head voice. Still, thei-e is a percentage in every class in school, whose inliei'ited musical perceptions are very feeble, and their slowness cannot but retard the general progress. Matiy of the ditlicnlties tliat beset the teacher of music in schools, then, ai'e eliminated at the stai-t ])y the choir trainer, when he selects boys with good voices, who sing in tune natui'ally. The increase in the number of vested (;hoii's in this country has been very rapid during the ])ast few years, and fortunately, the ideas which have prevailed among the majority of choir-masters on the subject of the boy voice, have been just. This is easily understood when we reflect that we have made the best English standards our ideal. The leaven of sound doctrine on the boy voice is working rapidly, and there are many choirs both iti our large and small cities that ai'c excellent examples of well-trained soprant^ ')^y"^- There is, however, one problem of male choir training which is not yet satisfactorily solved, at least it is troublesome to those choii's which have a small or moileratc aj)j)ropriation for music. Boy sopninos are plentiful, basses and tenors are easily obtained, but <^uod male altos, men. not boys, are almost unknown outside of a few laii:e cities. This state of aftair has led, in numy cases, to the employment of boys as altos, and thev iuive of course suiii; with the tliick or chest voice. It is an unmanaiieahle and unmusical voice, it is harsh, unsympathetic, haixl to keej) in tune, its presence in a choir is a constant menace to the soprano tone, and were it not foi- the idea that there is no recoui'se from this voice, save in the employment of wonum altos, it would not be tolerated by musicians. Thei-e is ;• recourse, however, and it is at the command of evcM-y choir trainer whose so\|)ranos liave l)een tau^lit to sin<j:; with the head voice alone. It is to select cei'tain soj)ranos. and when the voice breaks, let tluMii ])ass tc tlie alto part, and cniili/nn' fo i/se f/n' Iwiid 'Co'icc. Tlic ol)j<'cti()n wliich will natui'ally occui'. is, th;it iiM siiiL:iiin; should be pei-nntted dni-iiiu- tlie bi'cak. A\'('ll. let us consider. The ])eri(>d duriniT which the vmIcc, in c(Mnni(in paiiancc, is bi'cakinir. is a pei-i(Ml nf laryngeal growth, just as but the larynx is not. Every choir trainer must have observed the preliminaries to this period. A boy for instance, shows all at once a sudden increase of volume and hnds it ditiicult to sing unless quite loudly or softly. This shows that the vocal bands are relaxed. Following this, the speaking voice will lower in pitch, and show hoarseness at times. As soon though, as this hoarseness passes away, that is, when the congestion at the larynx has passed, the voice is better perhaps than befoi'o. Then comes anotlier break, as we sa}', that is, a period of sore throat and hoarseness. After this has passed, it may be that the l)oy has lost his upper notes, but can sing the lower ones witli ease; the tone too, is changed in timbre. It has the color of the man's head voice; or it may be that the boy can still sing his high notes, but that the lower ones are uncertain. V^oice mutation is not one continuous ])eriod of growth of vocal bands and laryngeal cartilages. On the contrary, the periods of vocal disturbance are sejiarated by intervals when tlie throat is eoni])ai'atively free from irritation. These intervals may he long or short. It evidently depends upon the raj)idity or slowness of the general growtli and development. There can be no doubt now, that during a time when the voice is uncertain and hoai'se fix>m the irritation of the vocal bands and snrniuiuliiig parts, x\v4t singing is p)()sitively harmful, but dui'ing the intervals sej)arating these y)eri(>ds, especially where they extend, as in many cases, over several months, it would seem that the singing voice might be used. Each individual case must be observed and judged by it.-^elf. This is entirely possible in choirs. If then the choir-master is careful to observe and to humor the changing voice at all ci-itical times; if he will insist that the boy sing vei'v liirhrly or not at all if it hurts him, and if he will i-esohit(,'ly check any tendency to bi-eak into the tenor or chest quality, he can train in a short time a good alto force from his choir, and these yoiuig men so trained nuiy become eflicient male alto sinirers. 130 OEILB VOICE IN SINGING, It is true that in many cases boys may be carried through the mutation period, and at the end show such light tone upon tlie falsetto or head voice as to be of no value. The strength and thnbre of the male falsetto depends partly upon the character of the vocal bands and partly of course upon the size and shape of the resonance cavities. Men who have voices of wide range and good volume in the chest or usual singing voice, generally possess strong head or falsetto tones, and it may be that soprano boys who possess large voices, that is those which show volume of tone along with purity, whose resonance cavities are large, will prove to develop a better falsetto, as men, than those boys whose voices are thinner. One other point remains to be disposed of. Will the use of this voice by youth or adult, injure his other voice, be it naturally bass, baritone, or tenor? No, it will not. and yet the average choir-master will most assuredly be met with this objection or fear. Tt is surprising that so many of those who ai'c in the busiuess of trving to teach voice, should be ignorant of the character and range of tlie nialo falsetto or liead voice, but in Sj)ite of tliis ignorance, and nioi'e or less ])ifjiKl ice against its use, the feai- that by using it one impairs the tones of the ciiest register or the usual singin<; voice, is utterly inrfounded. It is ])ic>(luced with far less effort and tension of the vocal bands than is the chest voice, and is physiolcgicallv perfectly safe. The inechanisni which the lai\iix employs to produce the falscitto is ju>t as natural as the mechanism emjiloyed to produce the clie.-t voice. That it is an unusual voice with us is due to cii'cumstances of musical development. I'he advent of the male vested choii' has, ]i()\vever, ci'catcd a demand for it, and it may be met as indicatcil. liy k(>e])ing boys upon the head voice duiiiii:" mutation or so much of the time as is safe, and afterwai'd, when the ai^e of adolescence is pa.-t. even if some ])refer to sini: bass oi- tenoi\ the nundx'i- of those available foi- the alto j)arts will be sutEcient to meet all requirements. GKNERAL REMARKS. TN the preceding chapters, dealing as they do -- with special subjects or subdivisions of the main topic, the effort has been to point out and to suggest some ways in which good vocal habits may be taught, and simple and effective vocal training carried on with whatever materials thei'e may be at hand in the shape of books, charts, blackboards, staves, etc. The leading idea is the correct use of the voice ; the particular st)iig or exercise which maybe cung is of no s]M'cial importance ; the way in which it is sung is everything. The benefits of tcacl.iing mi;sic reading iv. the schools are a ni<it:er of daily conuj^init. Is it, then, likely that the good resulting from the formaticjn of cori'eet ht^bitsin the use of the voice will fail of recognition? Xot so. For the eil'ect of good vocal ti-aining in scliool nnisic would be critics might be silenced. The lirst effect upon singing when tlie thick tone is forbidden and the attempt made to substitute the use of the voice in the tliin or head register nuiy l)e disa})puinting. It will seem to take awav all life and viij;or from the siuLijinir. Teachers who enjoy /ica/'f// singing will get nervous; they will doubt the value of the innovation. In those grades where chihh'cn range in age from twelve to fourteen years, the apparent loss in vocal power will disconcert the jMi[)ils even. Never mind ; the uw of the thin register will demonstrate its excellences, and it will, if slowly vet .--urely, increase in brilliance and telling ijuality of tone. Again, the compass downward needs to be m(jre resti-icted at tii->t than after the children have become habituated tt) its use. As long as there is any marked tcMuU'ncy to break into the chest-voice at certain [litches, the com[>ass should lie kfpt abo\-e them; as the teii(leiic\- weakens, the \oice may with due caution be cMn'ied to the lower tones, in higher grades be it unckTbtood. The tone slioiild <yrov7 softer as the voice descends when tlie lower notes will sound mellow and sweet. At tirst they may be quite l)reathy, but as the vocal l)ands become accustomed to the new action, the breathiness will disappear. One thing at a time is enough to attempt in music, and while a change in the use of tlie voice is being sought, it may happen that sacrifices must be made in other directions; part-singing, until the voices become equalized, that is, of a similar tone-quality throughout the entire compass, may, as it requires the singing of tones so low as to occasion easy recuri-ence to the thick voice, be so antagonistic to the desired end that it nnist be dropped for a time. After the use of the thin voice has Ik^couic firmly established, part-singing may be resnmed. Ilow low in ])itch the lower part may with safety be carried depends partly upon the age of tlie ])upils; but until the chestvoice begins to develop at ])ul)erty, all part-singing nnist be sung very lightly 'ds to the lower part or voice. rary in tlie decree of tlieir iiiahility from those who can sing only in monotone, to those who can sin^ in tnno wlien sini;in:f with those whose sense of piteli is good, l)ut aU)iie, eaniiot. A\'hiU' the nnml)er of entire or partial iiioiiotoiie voices (h;creases under daily drill and iiistnicrioii, yet there always remains a tronhlesome few, inst'iisihle to distinctions in pitcli ; it is, in view of the ji<»sible improvement tluy may make, a dilHcult matter to deal with them; for if they ai'e forhiddtui to sing, the chance to impi'ove is (K-nied tlu'iii, and if the}' sing and constantly di-ag down the pitch, Mhy the intonation of those who wonld otherwise sing true is injuriously atTecte(l. Many wiio sing monotone when the thick V(jice is used, do so hecause the thi'oat is weak and cannot ea.-ily sustain t le mu>cular strain; if they aiv trained to the use of the light, thir, tone, tluy can >ing in tuiu". A fter children ha\e heei\ under daily music drill for two or three years in .-cliool, if tluy still .-iiig monotone, it Would seem Iiiadvi>al)le to let them [)articipate with tlie class in >inging. 'riicy do themselves no good, and tluy certaitdy injure the singing of tlie others; for, as before suggested, constant falling from pitch will in time dull the musical perceptions of those most gifted by nature. During the early years of school-life the pupils may often sing out of tune because the vocal bands and controlling muscles are very weak. It is an excellent idea to separate the pupils into two classes : First, those who can sing with reasonably good intonation ; and second, those who can sing only a few tones, or only one. Let the second class frecjuently listen M-liile the others sing. Tliey will thus be taught to note both tone and pitch, and if any musical sense is dormant, this should arouse it; but, if after long and ])atieiit clfort a ])npil cannot sing, let him remain silent during the singing ])eriod. Every possiljle eifort should certaiidy be put forth to teach children to sing in tune, but yet it is now, and will doubtless remain true, that a small per cent, cannot be so taught. The primary causes of monotone singing may 1)0 })hysical or mental; in many cases, weak vocal organs and feublc nervous power, in others lack of pitch-perception — tonal blindness. The secondary causes include the influences of environment and lieredity. The contempt in wliich music has been lield by a portion of the English-speaking people from the time of the licformation until (piite recently, or shall wesjiy until even now, has made its powerful impress upon o])inions, tastes, and natural powers. ISinging, with a part of our population, is literally a lost art, lost through generations of disuse. It is often urged by educators that each study must he!]) other studies. The various subjects which are taught must move along, as it were, like the ])arts in a musical com])ositioii, dependent U[)on, sustaining, and harmonious with each other. Xow, while it is not within the scope of tlii> Work to discuss the relation of nmsic to other .-•tudie> in all of its bearings, it is yet clearly ir. line with its general tenor to suggest that the tone in singing will react upon the s])eakingvoice, and vice V'i'.sd. Now, if pupils recite and speak with a noisy, rough tone, it will not be easy to secure sweet, ])ure tone from them when they sing; but, oil the otlier hand, while iney may be specially trained in good singing-tone, it will not, as a re^ suit, follow that the speaking-voice will he similarly modified. Special attention must he given to this also; hut if children invariahl" sing with pure tone, it must he very easy to direct them into good vocal hahits in speaking and reading. It is no more neces.-ary for chihlren to recite in that horrihle, rasping tone sometimes heard, than it is to sing with harsh tone; and if the same principles are applied to the speaking-voice as are herein given for the management (tf the singing-voice, in so far as they may he a}>i)licahle, this harshness and coiirseness may he avoided. It is the pushed, forced tone in speccli or Song that is disagieeahle. If teachers will consign to well-merited ohlivion those two phrases, "speak u])" and "•sing out," and will, instead, secure purity and easy production of tone, with (Jtst/tidtHNx of d/ih-idat'ion^ they M'ill do wisely. Let us not hesitate to teach our pupils to know and to feel that which is beautiful, and good, and true, that our schools may promote the growth of good taste, and stand for the highest morality and the best culture. THE VOICE ASPA, ROSARIO. Exercises and Observations, Hitendiil to assist in the cultivation ut the voice . . . Si; BATES, JAMES. Voice Culture for Children. A iiractical Privcr en the Cu'livati'iii anil Preservation i.t \'oun^; \'<.ues tor the r.sc ( t Srh..ols. Choirs, and Solo Boys. BAVIN, J. T. The Elements of Singing. A:; Introduetion to \'oi( I- and ( hoir Trainir.j". au'i Sijjht-Sincinn paiTT boards BLAIR, HUGH. Three-part Studies for the use of Schools and Ladies Choirs. >• itT ard To:;!.- So!-ta . .::;bi:;ed' .M.P.. Xo. ,S 1 j .... 50 Lessons for the Medium Part of the Voice Uloth. cdt. >• I .'.n : 25 Lessons. .A St-qiK-: to -.i;,- .-ihovr IS Vocalises. .A Se.nu'. to ::•;,_■ Two-Part Exercises for Choirs and Schools. Mav be used with any system of Sol-fa. (M.P., Xo. 23) paper boards HIGGS, JAMES. A Collection of Twopart Sol-feggi in the iinncipal major keys, dcsij/ned for t)ie practice of choristers and vocal classes j^enerally. Selected from Durante, ilandcl, Leo, Scarlatti. StelTani, Xares,\Vebbe,etc. ( M.]'., Xo..",!) HOWARD, F. E. Child Voice in Singing, The. Treated from a physiolot;ical and a practical standji'iint and esr)eciallv adaj)teil to S.hools and Boy Choirs. (.V Xet B..ok) The exercises are written in lie treble ;ind ba-^s clrfs. in order that the book may be used by male and female voices m one class. .Suitable for Evening' Continuation McNAUGHT, W. G. Graduated Exercises for School Classes (movable Doh), containing 267 E.xercises Intended for use in connection with songs, etc., carefully selected to suit the capacity and particular circumstances of a class. The\' provi<ic quite as much as most school classes can find time to study. The<jretical as well as practical. They prcjvide carefully graded exercises and numerous songs (movable Doh). Bound in limp cloth. Or in the following editions: — MANN, RICHARD. A Manual of Singing, tor thr use of t'hoir Trainers and Schoolmasters. Xew Edition, with additions b\- J. Staincr . . paper b.,ards MILLER, C. W. I Edited by). The Office of " Tenebrae " .and directions for singing "The Passion," for use in the Episcopal Church .... PALMER, E. D. Exercises for the Tenor Voice, wuh iiifoductorv- remarks on Its training; and dcvcloiiniont. ^M.I^. No. SO) .... 1.00 PANSERON, A. Forty Melodic and Progressive Exercises for Soprano or Tenor. IMitcd, with Marks of ICxprcssion and PhrasinK. l.y A\lurto Randfijwcr. In Two Parts. S'ljirano ai'.d Mc/,zo-So\|irano or Tcri'ir and SMpr.anM, or Trnor and Parifinr. ICdited. with Marks of Kxprrssion ;i?id Phrasing. I'V A!licrto R,indi>:i'.-r. In Two Parts. RENDALL, EDWARD DAVEY. The Ek-nieiitary Principles of Music for Public Schools. .A iii.mu.il to l.r fTnpicN-i-d m choirs and sin.);ini; <-lassrs, ','. ith .•ipiHT.-!u-i-s containin:: i::i:sic fiir [iractical use . STAINER, J. Choral Society Vocalisation. Instructions .and ICxer. iscs m \''.icc Tr.ainmt;, to l,i- use i .it '.rdinary rehearsals. (,.\1.P.. Ni.. .">0l. .\dai.ted ,ind .irr:uu:ed f'>r the use of Chwirs and Classes. •! I-'.-inalo V.aces l.v .\rthur W .Marchant. VERNHAM, J.E. Seventy Three-Part Studies •.'. itlun th<' cunpass * .i:-. Octave. I'-r Sii;ht -SiiiK.nu; C'.asse-. (M.P.. N... l<n	30,247	common-pile/pre_1929_books_filtered	childvoiceinsing00howaiala	public_library	public_library_1929_dolma-0022.json.gz:2417	https://archive.org/download/childvoiceinsing00howaiala/childvoiceinsing00howaiala_djvu.txt
PTNqO36HrivrzcKO	7.4: Roles and Responsibililites of Health Care Professionals	7.4: Roles and Responsibililites of Health Care Professionals The second IPEC competency relates to the roles and responsibilities of health care professionals and states, “Use the knowledge of one’s own role and those of other professions to appropriately assess and address the health care needs of patients and to promote and advance the health of populations.” [1] See the following box for the components of this competency. It is important to understand the roles and responsibilities of the other health care team members; recognize one’s limitations in skills, knowledge, and abilities; and ask for assistance when needed to provide quality, patient-centered care. Components of IPEC’s Roles/Responsibilities Competency [2] - Communicate one’s roles and responsibilities clearly to patients, families, community members, and other professionals. - Recognize one’s limitations in skills, knowledge, and abilities. - Engage with diverse professionals who complement one’s own professional expertise, as well as associated resources, to develop strategies to meet specific health and health care needs of patients and populations. - Explain the roles and responsibilities of other providers and the manner in which the team works together to provide care, promote health, and prevent disease. - Use the full scope of knowledge, skills, and abilities of professionals from health and other fields to provide care that is safe, timely, efficient, effective, and equitable. - Communicate with team members to clarify each member’s responsibility in executing components of a treatment plan or public health intervention. - Forge interdependent relationships with other professions within and outside of the health system to improve care and advance learning. - Engage in continuous professional and interprofessional development to enhance team performance and collaboration. - Use unique and complementary abilities of all members of the team to optimize health and patient care. - Describe how professionals in health and other fields can collaborate and integrate clinical care and public health interventions to optimize population health. Nurses communicate with several individuals during a typical shift. For example, during inpatient care, nurses may communicate with patients and their family members; pharmacists and pharmacy technicians; providers from different specialties; physical, speech, and occupational therapists; dietary aides; respiratory therapists; chaplains; social workers; case managers; nursing supervisors, charge nurses, and other staff nurses; assistive personnel; nursing students; nursing instructors; security guards; laboratory personnel; radiology and ultrasound technicians; and surgical team members. Providing holistic, quality, safe, and effective care means every team member taking care of patients must work collaboratively and understand the knowledge, skills, and scope of practice of the other team members. Table 7.4 provides examples of the roles and responsibilities of common health care team members that nurses frequently work with when providing patient care. To fully understand the roles and responsibilities of the multiple members of the complex health care delivery system, it is beneficial to spend time shadowing those within these roles. \| Member \| Role/Responsibilities \| \|---\|---\| \| Assistive Personnel (e.g., certified nursing assistants [CNA], patient-care technicians [PCT], certified medical assistants [CMA], certified medication aides, and home health aides) \| Work under the direct supervision of the RN. (Read more about Assistive Personnel (AP) in the “ Delegation and Supervision ” chapter.) \| \| Licensed Practical/Vocational Nurses (LPN/VN) \| Assist the RN by performing routine, basic nursing care with predictable outcomes. (Read more details in the “ Delegation and Supervision ” chapter.) \| \| Registered Nurses (RN) \| Use the nursing process to assess, diagnose, identify expected outcomes, plan and implement interventions, and evaluate care according to the Nurse Practice Act of the state they are employed. \| \| Charge Nurses or Nursing Supervisors \| Supervise members of the nursing team and overall patient care on the unit (or organization) to ensure quality, safe care is delivered. \| \| Directors of Nursing (DON), Chief Nursing Officer (CNO), or Vice President of Patient Services \| Ensure federal and state regulations and standards are being followed and are accountable for all aspects of patient care. \| \| Clinical Nurse Specialist (CNS) \| Practice in a variety of health care environments and participate in mentoring other nurses, case management, research, designing and conducting quality improvement programs, and serving as educators and consultants. \| \| Nurse Practitioners (NP) or Advanced Practice Registered Nurses (APRN) \| Work in a variety of settings and complete physical examinations, diagnose and treat common acute illness, manage chronic illness, order laboratory and diagnostic tests, prescribe medications and other therapies, provide health teaching and supportive counseling with an emphasis on prevention of illness and health maintenance, and refer clients to other health professionals and specialists as needed. NPs have advanced knowledge with a graduate degree and national certification. \| \| Certified Registered Nurse Anesthetists (CRNA) \| Administer anesthesia and related care before, during, and after surgical, therapeutic, diagnostic, and obstetrical procedures, as well as provide airway management during medical emergencies. \| \| Certified Nurse Midwives (CNM) \| Provide gynecological exams, family planning guidance, prenatal care, management of low-risk labor and delivery, and neonatal care. \| \| Medical Doctors (MD) \| Licensed providers who diagnose, treat, and direct medical care. There are many types of physician specialists such as surgeons, pulmonologists, neurologists, cardiologists, nephrologists, pediatricians, and ophthalmologists. \| \| Physician Assistants (PA) \| Work under the direct supervision of a medical doctor as licensed and certified professionals following protocols based on the state in which they practice. \| \| Doctors of Osteopathy (DO) \| Licensed providers similar to medical physicians but with different educational preparation and licensing exams. They provide care, prescribe, and can perform surgeries. \| \| Dieticians \| Assess, plan, implement, and evaluate interventions related to specific dietary needs of clients, including regular or therapeutic diets. Formulate diets for clients with dysphagia or other physical disorders and provide dietary education such as diabetes education. \| \| Physical Therapists (PT) \| Develop and implement a plan of care as a licensed professional for clients with dysfunctional physical abilities, including joints, strength, mobility, gait, balance, and coordination. \| \| Occupational Therapists (OT) \| Plan, provide, and evaluate care for clients with dysfunction affecting their independence and ability to complete activities of daily living (ADLs). Assist clients in using adaptive devices to reach optimal levels of functioning and provide home safety assessments. \| \| Speech Therapists (ST) \| Develop and initiate a plan of care for clients diagnosed with communication and swallowing disorders. \| \| Respiratory Therapists (RT) \| Specialize in treating clients with respiratory disorders or conditions in collaboration with providers. Provide treatments such as CPAP, BiPAP, respiratory treatments and medications like aerosol nebulizers, chest physiotherapy, and postural drainage. They also intubate clients, assist with bronchoscopies, manage mechanical ventilation, and perform pulmonary function tests. \| \| Social Workers (SW) \| Provide a liaison between the community and the health care setting to ensure continuity of care after discharge. Assist clients with establishing community resources, health insurance, and advance directives. \| \| Psychologists and Psychiatrists \| Provide mental health services to clients in both acute and long-term settings. As physician specialists, psychiatrists prescribe medications and perform other medical treatments for mental health disorders. Psychologists focus on counseling. \| \| Nurse Case Managers or Discharge Planners \| Ensure clients are provided with effective and efficient medical care and services, during inpatient care and post-discharge, while also managing the cost of these services. \| The coordination and delivery of safe, quality patient care demands reliable teamwork and collaboration across the organizational and community boundaries. Clients often have multiple visits across multiple providers working in different organizations. Communication failures between health care settings, departments, and team members is the leading cause of patient harm. [3] The health care system is becoming increasingly complex requiring collaboration among diverse health care team members. The goal of good interprofessional collaboration is improved patient outcomes, as well as increased job satisfaction of health care team professionals. Patients receiving care with poor teamwork are almost five times as likely to experience complications or death. Hospitals in which staff report higher levels of teamwork have lower rates of workplace injuries and illness, fewer incidents of workplace harassment and violence, and lower turnover. [4] Valuing and understanding the roles of team members are important steps toward establishing good interprofessional teamwork. Another step is learning how to effectively communicate with interprofessional team members. - Interprofessional Education Collaborative. IPEC core competencies. https://www.ipecollaborative.org/ipec-core-competencies ↵ - Interprofessional Education Collaborative. IPEC core competencies. https://www.ipecollaborative.org/ipec-core-competencies ↵ - Rosen, M. A., DiazGranados, D., Dietz, A. S., Benishek, L. E., Thompson, D., Pronovost, P. J., & Weaver, S. J. (2018). Teamwork in healthcare: Key discoveries enabling safer, high-quality care. The American Psychologist, 73 (4), 433-450. https://doi.org/10.1037/amp0000298 ↵ - Rosen, M. A., DiazGranados, D., Dietz, A. S., Benishek, L. E., Thompson, D., Pronovost, P. J., & Weaver, S. J. (2018). Teamwork in healthcare: Key discoveries enabling safer, high-quality care. The American Psychologist, 73 (4), 433-450. https://doi.org/10.1037/amp0000298 ↵	1,903	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Nursing/Nursing_Management_and_Professional_Concepts_1e_(OpenRN)/07%3A_Collaboration_Within_the_Interprofessional_Team/7.04%3A_Roles_and_Responsibililites_of_Health_Care_Professionals	libretexts	libretexts-0000.json.gz:9049	https://med.libretexts.org/Bookshelves/Nursing/Nursing_Management_and_Professional_Concepts_1e_(OpenRN)/07%3A_Collaboration_Within_the_Interprofessional_Team/7.04%3A_Roles_and_Responsibililites_of_Health_Care_Professionals
q0FJitmNFcJ0TQNx	Industrial Poisoning from Fumes, Gases and Poisons of Manufacturing Processes	Produced by Suzanne Lybarger, Brian Janes and the Online Distributed Proofreading Team at http://www.pgdp.net INDUSTRIAL POISONING FROM FUMES, GASES AND POISONS OF MANUFACTURING PROCESSES BY THE SAME AUTHOR LEAD POISONING AND LEAD ABSORPTION: THE SYMPTOMS, PATHOLOGY AND PREVENTION, WITH SPECIAL REFERENCE TO THEIR INDUSTRIAL ORIGIN AND AN ACCOUNT OF THE PRINCIPAL PROCESSES INVOLVING RISK. By THOMAS M. LEGGE M.D. (Oxon.), D.P.H. (Cantab.), H.M. Medical Inspector of Factories; Lecturer on Factory Hygiene, University of Manchester; and KENNETH W. GOADBY, D.P.H. (Cantab.), Pathologist and Lecturer on Bacteriology, National Dental Hospital. Illustrated. viii+308 pp. 12s. 6_d._ net. LONDON: EDWARD ARNOLD. INDUSTRIAL POISONING FROM FUMES, GASES AND POISONS OF MANUFACTURING PROCESSES BY DR. J. RAMBOUSEK PROFESSOR OF FACTORY HYGIENE, AND CHIEF STATE HEALTH OFFICER, PRAGUE TRANSLATED AND EDITED BY THOMAS M. LEGGE, M.D., D.P.H. H.M. MEDICAL INSPECTOR OF FACTORIES JOINT AUTHOR OF ‘LEAD POISONING AND LEAD ABSORPTION’ WITH ILLUSTRATIONS LONDON EDWARD ARNOLD 1913 TRANSLATOR’S PREFACE I undertook the translation of Dr. Rambousek’s book because it seemed to me to treat the subject of industrial poisons in as novel, comprehensive, and systematic a manner as was possible within the compass of a single volume. Having learnt much myself from Continental writings on industrial diseases and factory hygiene, I was anxious to let others also see how wide a field they had covered and how thorough were the regulations for dangerous trades abroad, especially in Germany. A praiseworthy feature of Dr. Rambousek’s book was the wealth of references to the work of foreign writers which is made on almost every page. To have left these names and references, however, in the text as he has done would have made the translation tedious reading, and therefore for the sake of those who desire to pursue inquiry further I have adopted the course of collecting the great majority and placing them all together in an appendix at the end of the volume. Dr. Rambousek as a medical man, a chemist, and a government official having control of industrial matters, is equipped with the very special knowledge required to describe the manufacturing processes giving rise to injurious effects, the pathology of the lesions set up, and the preventive measures necessary to combat them. In his references to work done in this country he has relied largely on abstracts which have appeared in medical and technical journals published on the Continent. I have only thought it necessary to amplify his statements when important work carried out here on industrial poisoning,—such as that on nickel carbonyl and on ferro-silicon—had been insufficiently noted. Such additions are introduced in square brackets or in footnotes. In his preface Dr. Rambousek says ‘the book is intended for all who are, or are obliged to be, or ought to be, interested in industrial poisoning.’ No words could better describe the scope of the book. The work of translation would never have been begun but for the assistance given me in Parts II and III by my sister, Miss H. Edith Legge. To her, and to Mr. H. E. Brothers, F.I.C., who has been to the trouble of reading the proofs and correcting many mistakes which my technical knowledge was insufficient to enable me to detect, my best thanks are due. I am indebted to Messrs. Davidson & Co., Belfast, for permission to use figs. 46 and 48; to Messrs. Locke, Lancaster & Co., Millwall, for fig. 27; to Mr. R. Jacobson, for figs. 30, 33, 37, 38, and 43; to Messrs. Siebe, Gorman & Co., for figs. 32, 39, and 40; to Messrs. Blackman & Co. for fig. 47; to Messrs. Matthews & Yates for fig. 54; to H.M. Controller of the Stationery Office for permission to reproduce figs. 52, 53, and 54, and the diagrams on p. 284; and lastly to my publisher, for figs. 41, 42, 43, and 49, which are taken from the book by Dr. K. W. Goadby and myself on ‘Lead Poisoning and Lead Absorption.’ T. M. L. HAMPSTEAD, _May 1913_. CONTENTS PAGE INTRODUCTION xiii Part I.—Description of the industries and processes attended with risk of poisoning: incidence of such poisoning CHEMICAL INDUSTRY 1 Sulphuric acid industry (sulphur dioxide): use of sulphuric acid 4 Its effects on health 9 Hydrochloric acid, saltcake and soda industry 14 Their effects on health 20 Use of sulphate and sulphide of soda 22 Ultramarine 22 Sulphonal 22 Diethyl sulphate 23 Chlorine, chloride of lime and chlorates 23 Their effect on health 26 Other chlorine compounds and their use as well as bromine, iodine and fluorine 29 Chlorides of phosphorus 30 Chlorides of sulphur 31 Zinc chloride 32 Rock salt 32 Organic chlorine compounds 32 Carbon oxychloride (phosgene) 32 Carbon chlorine compounds (aliphatic) 33 Methyl chloride 33 Methylene chloride 34 Carbon tetrachloride 34 Ethyl chloride 34 Monochloracetic acid 34 Chloral 34 Chloroform 34 Chloride of nitrogen 35 Cyanogen chloride 35 Chlorobenzene 35 Benzo trichloride, benzyl chloride 35 Nitro- and dinitro-chlorobenzene 35 Iodine and iodine compounds 36 Bromine and bromine compounds 36 Methyl iodide and methyl bromide 36 Fluorine compounds 37 Hydrofluoric and silicofluoric acids 38 Manufacture and uses of nitric acid 39 Its effect on health 40 Nitric and nitrous salts and compounds 44 Barium nitrate 44 Ammonium nitrate 44 Lead nitrate 44 Mercurous and mercuric nitrate 44 Silver nitrate 45 Sodium nitrite 45 Amyl nitrite 45 Manufacture of explosives and their effects 45 Fulminate of mercury 46 Nitro-glycerin 46 Dynamite 47 Gun cotton 48 Collodion cotton, smokeless powder 48 Manufacture of phosphorus and lucifer matches and their effects 49 Other uses of phosphorus and compounds of phosphorus 52 Phosphor-bronze 52 Sulphide of phosphorus 52 Phosphoretted hydrogen 52 Superphosphate and artificial manure 53 Basic slag 54 Chromium compounds and their uses 55 Sodium and potassium bichromate 55 Lead chromate and chrome colours 55 Their effect on health 56 Manganese compounds and their effects 58 Mineral oil industry and the use of petroleum and benzine 59 Chemical cleaning 61 Their effect on health 61 Recovery and use of sulphur 64 Its effect on health 65 Sulphuretted hydrogen and its effect 65 Preparation and use of carbon bisulphide in vulcanising, &c. 68 Its effect on health 69 Preparation of illuminating gas 71 Its effect on health 74 Coke ovens and risk from them 77 Other kinds of power and illuminating gas 80 Producer gas 80 Blast furnace gas 82 Water gas 82 Dowson and Mond gas 82 Suction gas 83 Acetylene (calcium carbide) 85 Their effect on health 87 Ammonia and ammonium compounds 90 Use of ammonia and its effects 92 Cyanogen compounds 93 Use of cyanide, and their effects 95 Coal tar and tar products 96 Their effects on health 101 Artificial organic dye stuffs (coal tar colours) 107 Their effects on health 112 RECOVERY AND USE OF METALS 120 Lead poisoning in general 120 Lead, silver and zinc smelting 122 Spelter works 125 Lead poisoning in lead smelting and spelter works 126 White lead and other use of lead colours 131 Lead poisoning in the manufacture and use of white lead and lead paints 132 Manufacture of electric accumulators 134 The ceramic industry 135 Coarse ware pottery 136 Manufacture of stove tiles 137 Stoneware and porcelain 138 Lead poisoning in letterpress printing 138 Lead poisoning in filecutting, polishing precious stones, musical instrument making, &c. 140 Mercury (poisoning in its recovery and use) 141 Mercurial poisoning in water-gilding, coating mirrors, in felt hat making, &c. 142 Arsenic (poisoning in its recovery and in use of arsenic and arsenic compounds) 143 Recovery of arsenic and white arsenic 143 Poisoning by arseniuretted hydrogen gas 145 Antimony 146 Extraction of iron 146 Ferro-silicon 149 Zinc 151 Copper, brass (brassfounders’ ague) 151 Metal pickling 152 OTHER INDUSTRIES 153 Treatment of stone and earths; lime burning, glass 153 Treatment of animal products 154 Preparation of vegetable foodstuffs 154 Poisonous woods 154 Textile industry 156 Part II.—Pathology and treatment of industrial poisoning INDUSTRIAL POISONS IN GENERAL 157 Channels of absorption, classification, susceptibility, immunity 158 Fate of poisons in the body—absorption, cumulative action, excretion 162 General remarks on treatment 163 INDUSTRIAL POISONS IN PARTICULAR 169 Group: mineral acids, halogens, inorganic halogen compounds, alkalis 169 Hydrochloric acid 170 Hydrofluoric and silico-fluoric acids 171 Sulphur dioxide and sulphuric acid 171 Nitrous fumes, nitric acid 172 Chlorine, bromine, iodine 173 Chlorides of phosphorus, sulphur and zinc 174 Ammonia 175 Alkalis 176 Group: Metals and metal-compounds 176 Lead and its compounds 177 Zinc and its alloys 182 Mercury and its compounds 183 Manganese and its compounds 184 Chromium and its compounds 185 Nickel salts (nickel carbonyl) 186 Copper 188 Silver and its compounds 188 Group: Arsenic, Phosphorus 189 Arsenic and its oxides 189 Phosphorus 190 Phosphoretted hydrogen 191 Group: Sulphuretted hydrogen, carbon bisulphide, and cyanogen (nerve poisons) 192 Sulphuretted hydrogen 192 Carbon bisulphide 193 Cyanogen compounds 195 Group: Arseniuretted hydrogen and carbonic oxide (blood poisons) 197 Group: Hydrocarbons of the aliphatic and aromatic series and their halogen and hydroxyl substitution products 202 Sub-group: Hydrocarbons of mineral oils and their distillation products (benzine, paraffin, &c.) 202 Sub-group: Hydrocarbons of the aromatic series 204 Benzene and its homologues 204 Naphthalene 208 Sub-group: Halogen substitution products of the aliphatic series (narcotic poisons) 208 Sub-group: Halogen substitution products of the benzene series 209 Sub-group: Hydroxyl substitution products of the fatty series 210 Group: Nitro- and amido-derivatives of the aliphatic and aromatic series 211 Sub-group: Nitro-derivatives of the aliphatic series 212 Sub-group: Nitro- and amido-derivatives of the aromatic series 212 Turpentine, pyridene, alkaloids, nicotine, poisonous woods 215 Part III.—Preventive measures against industrial poisoning GENERAL PREVENTIVE MEASURES 217 International action, notification of poisoning, schedules of poisons 218 Special preventive measures for workers—selection, periodical medical examination, co-operation of workers, &c. 226 Rescue appliances 230 Washing accommodation and baths 237 Removal of dust and fumes by exhaust ventilation 242 PREVENTIVE MEASURES IN PARTICULAR INDUSTRIES 256 Sulphuric acid industry 256 Hydrochloric acid and soda industries 257 Chlorine, bleaching powder, chlorine compounds 259 Manufacture of nitric acid and explosives 260 Artificial manures, basic slag 261 Chromium and its compounds 265 Petroleum, benzine 267 Phosphorus, lucifer matches 268 Bisulphide of carbon 271 Illuminating gas, tar production 275 Gas power plant 276 Acetylene gas installations 278 Ammonia 279 Cyanogen, cyanogen compounds 280 Coal tar, tar products 280 Organic dye-stuffs, coal tar colours 285 Recovery and use of metals 288 Iron 289 Lead 292 Lead smelting 299 Electric accumulators 305 White lead and lead colours 310 Letterpress printing 316 Ceramic industry 319 File cutting 321 Other uses of lead 322 Zinc smelting 323 Brass casting, metal pickling 325 Recovery and use of mercury 326 Arsenic and its compounds 328 Gold and silver 329 PREVENTIVE MEASURES IN OTHER TRADES 329 Manufacture and use of varnishes 330 Production of vegetable foods 332 Wood working 335 Paper manufacture 336 Textile industries 336 APPENDIX 339 INDEX 355 INTRODUCTION The attempt to systematise from the scientific standpoint the mass of material that has been collected about poisons is a very heavy task, even for the toxicologist who desires to treat his subject comprehensively. How much greater is the difficulty of writing a systematic book on industrial poisoning keeping practical application in the forefront! Technical considerations which are decisive in the causation and prevention of industrial poisoning are here of especial moment, and must naturally influence classification of the subject-matter when the object is to assist those concerned in factory hygiene. Bearing this in mind, I have divided the subject into three parts. The arrangement of the first, which gives as complete a statement as possible of the occurrence of industrial poisoning, into industries and processes was determined on technical grounds. The second, which amplifies the first, attempts to summarise the pathology or symptoms of the various forms of poisoning. The references to the literature of the particular subjects—as exhaustive as I could make them—will lighten further study. To these two parts, following on knowledge of causation and symptoms, the third, in which preventive measures are outlined, is linked. The apparent drawback in use of the book is that one form of poisoning has often to be referred to in three places. But, I hope, this is more than counterbalanced by the completeness of the scheme which results from the subdivision of the subject. The pathology of industrial poisoning necessitates frequent repetition when describing the branches of industry giving rise to the intoxication, as one and the same form can occur in the most varied processes. The numerous instances of actual cases of poisoning quoted must therefore be regarded as conforming to the same pathological type. Similarly, preventive measures require separate systematic treatment in order to avoid constant repetition which would otherwise obscure the general survey. Quite a number of means of prevention apply equally to several industries in which the same cause is at work. The success attained by thus simplifying the issues is the greater because such common measures are the easier to carry through and to supervise. The method therefore has been adopted only after serious reflection and has been directed mainly by practical considerations. Recent cases which have either been reported or come to the knowledge of the author have been given, with particulars as exact as possible. Cases dating back some time have been omitted intentionally so as to exclude everything which did not correspond with the present conditions of industry and trade. Historical facts only receive consideration in so far as they are fundamentally important and necessary for the sake of completeness. The details given in Part I of actual instances will supply material for fresh efforts, renewed investigation, and new points of attack. INDUSTRIAL POISONING PART I _DESCRIPTION OF THE INDUSTRIES AND PROCESSES ATTENDED WITH RISK OF POISONING; INCIDENCE OF SUCH POISONING_ I. THE CHEMICAL INDUSTRY GENERAL CONSIDERATIONS AS TO INCIDENCE OF INDUSTRIAL POISONING The chemical industry offers naturally a wide field for the occurrence of industrial poisoning. Daily contact with the actual poisonous substances to be prepared, used, stored, and despatched in large quantity gives opportunity for either acute or chronic poisoning—in the former case from sudden accidental entrance into the system of fairly large doses, as the result of defective or careless manipulation, and, in the latter, constant gradual absorption (often unsuspected) of the poison in small amount. The industry, however, can take credit for the way in which incidence of industrial poisoning has been kept down in view of the magnitude and variety of the risks which often threaten. This is attributable to the comprehensive hygienic measures enforced in large chemical works keeping abreast of modern advance in technical knowledge. A section of this book deals with the principles underlying these measures. Nevertheless, despite all regulations, risk of poisoning cannot be wholly banished. Again and again accidents and illness occur for which industrial poisoning is responsible. Wholly to prevent this is as impossible as entirely to prevent accidents by mechanical guarding of machinery. Owing to the unknown sources of danger, successful measures to ward it off are often difficult. The rapid advance of this branch of industry, the constant development of new processes and reactions, the frequent discovery of new materials (with properties at first unknown, and for a long time insufficiently understood, but nevertheless indispensable), constantly give rise to new dangers and possibilities of danger, of which an accident or some disease with hitherto unknown symptoms is the first indication. Further, even when the dangerous effects are recognised, there may often be difficulty in devising appropriate precautions, as circumstances may prevent immediate recognition of the action of the poison. We cannot always tell, for instance, with the substances used or produced in the processes, which is responsible for the poisoning, because, not infrequently, the substances in question are not chemically pure, but may be either raw products, bye-products, &c., producing mixtures of different bodies or liberating different chemical compounds as impurities. Hence difficulty often arises in the strict scientific explanation of particular cases of poisoning, and, in a text-book such as this, difficulty also of description. A rather full treatment of the technical processes may make the task easier and help to give a connected picture of the risks of poisoning in the chemical industry. Such a procedure may be especially useful to readers insufficiently acquainted with chemical technology. We are indebted to Leymann[1] and Grandhomme[2] especially for knowledge of incidence of industrial poisoning in this industry. The statistical data furnished by them are the most important proof that poisoning, at any rate in large factories, is not of very frequent occurrence. Leymann’s statistics relate to a large modern works in which the number employed during the twenty-three years of observation increased from 640 in the year 1891 to 1562 in 1904, giving an average of about 1000 yearly, one-half of whom might properly be defined as ‘chemical workers.’ The factory is concerned in the manufacture of sulphuric, nitric, and hydrochloric acids, alkali, bichromates, aniline, trinitro-phenol, bleaching powder, organic chlorine compounds, and potassium permanganate. These statistics are usefully complemented by those of Grandhomme drawn from the colour works at Höchst a-M. This large aniline works employs from 2600 to 2700 workers; the raw materials are principally benzene and its homologues, naphthalene and anthracene. The manufacture includes the production of coal-tar colours, nitro- and dinitro-benzene, aniline, rosaniline, fuchsine, and other aniline colours, and finally such pharmaceutical preparations as antipyrin, dermatol, sanoform, &c. Of the 2700 employed, 1400 are chemical workers and the remainder labourers. These two series of statistics based on exact observations and covering allied chemical manufacture are taken together. They seek to give the answer to the question—How many and what industrial poisonings are found? The figures of Leymann (on an average of 1000 workers employed per annum) show 285 cases of poisoning reported between the years 1881 and 1904. Of these 275 were caused by aniline, toluidine, nitro- and dinitro-benzene, nitrophenol, nitrochloro and dinitrochloro benzene. Three were fatal and several involved lengthy invalidity (from 30 to 134 days, owing to secondary pneumonia). Included further are one severe case of chrome (bichromate) poisoning (with nephritis as a sequela), five cases of lead poisoning, three of chlorine, and one of sulphuretted hydrogen gas. In the Höchst a-M. factory (employing about 2500 workers) there were, in the ten years 1883-92, only 129 cases of poisoning, of which 109 were due to aniline. Later figures for the years 1893-5 showed 122 cases, of which 43 were due to aniline and 76 to lead (contracted mostly in the nitrating house). Grandhomme mentions further hyperidrosis among persons employed on solutions of calcium chloride, injury to health from inhalation of methyl iodide vapour in the antipyrin department, a fatal case of benzene poisoning (entering an empty vessel in which materials had previously been extracted with benzene), and finally ulceration and perforation of the septum of the nose in several chrome workers. The number of severe cases is not large, but it must be remembered that the factories to which the figures relate are in every respect models of their kind, amply provided with safety appliances and arrangements for the welfare of the workers. The relatively small amount of poisoning is to be attributed without doubt to the precautionary measures taken. Further, in the statistics referred to only those cases are included in which the symptoms were definite, or so severe as to necessitate medical treatment. Absorption of the poison in small amount without producing characteristic symptoms, as is often the case with irritating or corrosive fumes, and such as involve only temporary indisposition, are not included. Leymann himself refers to this when dealing with illness observed in the mineral acid department (especially sulphuric acid), and calls attention to the frequency of affections of the respiratory organs among the persons employed, attributing them rightly to the irritating and corrosive effect of the acid vapour. Elsewhere he refers to the frequency of digestive disturbance among persons coming into contact with sodium sulphide, and thinks that this may be due to the action of sulphuretted hydrogen gas. Nevertheless, the effect of industrial poisons on the health of workers in chemical factories ought on no account to be made light of. The admirable results cited are due to a proper recognition of the danger, with consequent care to guard against it. Not only have Grandhomme and Leymann[A] rendered great services by their work, but the firms in question also, by allowing such full and careful inquiries to be undertaken and published. SULPHURIC ACID (SULPHUR DIOXIDE) MANUFACTURE.—Sulphur dioxide, generally obtained by roasting pyrites in furnaces of various constructions, or, more rarely, by burning brimstone or sulphur from the spent oxide of gas-works, serves as the raw material for the manufacture of sulphuric acid. Before roasting the pyrites is crushed, the ‘lump ore’ then separated from the ‘smalls,’ the former roasted in ‘lump-burners’ or kilns (generally several roasting furnace hearths united into one system), and the latter preferably in Malétra and Malétra-Schaffner shelf-burners (fig. 1) composed of several superimposed firebrick shelves. The pyrites is charged on to the uppermost shelf and gradually worked downwards. Pyrites residues are not suitable for direct recovery of iron, but copper can be recovered from residues sufficiently rich in metal by the wet process; the residues thus freed of copper and sulphur are then smelted for recovery of iron. [Illustration: FIG. 1.—Pyrites Burner for Smalls (_after Lueger_)] Utilisation for sulphuric acid manufacture of the sulphur dioxide given off in the calcining of zinc blende (see Spelter works), impracticable in reverberatory furnaces, has been made possible at the Rhenania factory by introduction of muffle furnaces (several superimposed), because by this means the gases led off are sufficiently concentrated, as they are not diluted with the gases and smoke from the heating fires. This method, like any other which utilises the gases from roasting furnaces, has great hygienic, in addition to economical, advantages, because escape of sulphur dioxide gas is avoided. Furnace gases, too poor in sulphur dioxide to serve for direct production of sulphuric acid, can with advantage be made to produce liquid anhydrous sulphur dioxide. Thus, the sulphur dioxide gas from the furnaces is first absorbed by water, driven off again by boiling, cooled, dried, and liquefied by pressure. The gaseous sulphur dioxide obtained by any of the methods described is converted into sulphuric acid either by (_a_) the chamber process or (_b_) the contact process. In the _lead chamber process_ the furnace gases pass through flues in which the flue dust and a portion of the arsenious acid are deposited into the Glover tower at a temperature of about 300° C., and from there into the lead chambers where oxidation of the sulphur dioxide into sulphuric acid takes place, in the presence of sufficient water, by transference of the oxygen of the air through the intervention of the oxides of nitrogen. The gases containing oxides of nitrogen, &c., which are drawn out of the lead chambers, have the nitrous fumes absorbed in the Gay-Lussac tower (of which there are one or two in series), by passage through sulphuric acid which is made to trickle down the tower. The sulphuric acid so obtained, rich in oxides of nitrogen, and the chamber acid are led to the Glover tower for the purpose of denitration and concentration, so that all the sulphuric acid leaves the Glover as Glover acid of about 136-144° Tw. Losses in nitrous fumes are best made up by addition of nitric acid at the Glover or introduction into the first chamber. The deficiency is also frequently made good from nitre-pots. The lead chambers (fig. 2) are usually constructed entirely—sides, roof, and floor—of lead sheets, which are joined together by means of a hydrogen blowpipe. The sheets forming the roof and walls are supported, independent of the bottom, on a framework of wood. The capacity varies from 35,000 to 80,000 cubic feet. The floor forms a flat collecting surface for the chamber acid which lutes the chamber from the outer air. The necessary water is introduced into the chamber as steam or fine water spray. The Glover and Gay-Lussac towers are lead towers. The Glover is lined with acid-proof bricks and filled with acid-proof packing to increase the amount of contact. The Gay-Lussac is filled with coke over which the concentrated sulphuric acid referred to above flows, forming, after absorption of the nitrous fumes, nitro-sulphuric acid. [Illustration: FIG. 2A.—Lead Chamber System—Section through X X (_after Ost_) FIG. 2B.—Lead Chamber System—Plan A Pyrites Burner B Glover Tower C Draft Regulator D, D´ Lead Chambers E Air Shaft F, F,´ F,´´ F´´´ Acid Reservoirs G Acid Egg H Cooler J Gay-Lussac Tower] As already stated, two Gay-Lussac towers are usually connected together, or where there are several lead-chamber systems there is, apart from the Gay-Lussac attached to each, a central Gay-Lussac in addition, common to the whole series. The introduction of several Gay-Lussac towers has the advantage of preventing loss of the nitrous fumes as much as possible—mainly on economical grounds, as nitric acid is expensive. But this arrangement is at the same time advantageous on hygienic grounds, as escape of poisonous gases containing nitrous fumes, &c., is effectually avoided. The acids are driven to the top of the towers by compressed air. The whole system—chambers and towers—is connected by means of wide lead conduits. Frequently, for the purpose of quickening the chamber process (by increasing the number of condensing surfaces) Lunge-Rohrmann plate towers are inserted in the system—tall towers lined with lead in which square perforated plates are hung horizontally, and down which diluted sulphuric acid trickles. To increase the draught in the whole system a chimney is usual at the end, and, in addition, a fan of hard lead or earthenware may be introduced in front of the first chamber or between the two Gay-Lussac towers. Maintenance of a constant uniform draught is not only necessary for technical reasons, but has hygienic interest, since escape of injurious gases is avoided (see also Part III). The chamber acid (of 110°-120° Tw. = 63-70 %) and the stronger Glover acid (of 136°-144° Tw. = 75-82 %) contain impurities. In order to obtain for certain purposes pure strong acid the chamber acid is purified and concentrated. The impurities are notably arsenious and nitrous acids (Glover acid is N free), lead, copper, and iron. Concentration (apart from that to Glover acid in the Glover tower) is effected by evaporation in lead pans to 140° Tw. and finally in glass balloons or platinum stills to 168° Tw. (= 97 %). The lead pans are generally heated by utilising the waste heat from the furnaces or by steam coils in the acid itself, or even by direct firing. Production of sulphuric acid by the _contact method_ depends on the fact that a mixture of sulphur dioxide and excess of oxygen (air) combines to form sulphur trioxide at a moderate heat in presence of a contact substance such as platinised asbestos or oxide of iron. The sulphur dioxide must be carefully cleaned and dried, and with the excess of air is passed through the contact substance. If asbestos carrying a small percentage of finely divided platinum is the contact substance, it is generally used in the form of pipes; oxide of iron (the residue of pyrites), if used, is charged into a furnace. Cooling by a coil of pipes and condensation in washing towers supplied with concentrated sulphuric acid always forms a part of the process. A fan draws the gases from the roasting furnaces and drives them through the system. The end product is a fuming sulphuric acid containing 20-30 per cent. SO₃. From this by distillation a concentrated acid and a pure anhydride are obtained. From a health point of view it is of importance to know that all sulphuric acid derived from this anhydride is pure and free from arsenic. The most important _uses_ of sulphuric acid are the following: as chamber acid (110°-120° Tw.) in the superphosphate, ammonium sulphate, and alum industries; as Glover acid (140°-150° Tw.) in the Leblanc process, i.e. saltcake and manufacture of hydrochloric acid, and to etch metals; as sulphuric acid of 168° Tw. in colour and explosives manufacture (nitric acid, nitro-benzene, nitro-glycerine, gun-cotton, &c.); as concentrated sulphuric acid and anhydride for the production of organic sulphonic acids (for the alizarin and naphthol industry) and in the refining of petroleum and other oils. Completely de-arsenicated sulphuric acid is used in making starch, sugar, pharmaceutical preparations, and in electrical accumulator manufacture. EFFECTS ON HEALTH.—The health of sulphuric acid workers cannot in general be described as unfavourable. In comparison with chemical workers they have, it is said, relatively the lowest morbidity. Although in this industrial occupation no special factors are at work which injure in general the health of the workers, there is a characteristic effect, without doubt due to the occupation—namely, disease of the respiratory organs. Leymann’s figures are sufficiently large to show that the number of cases of diseases of the respiratory organs is decidedly greater in the sulphuric acid industry than among other chemical workers. He attributes this to the irritating and corrosive effect of sulphur dioxide and sulphuric acid vapour on the mucous membrane of the respiratory tract, as inhalation of these gases can never be quite avoided, because the draught in the furnace and chamber system varies, and the working is not always uniform. Strongly irritating vapours escape again in making a high percentage acid in platinum vessels, which in consequence are difficult to keep air-tight. Of greater importance than these injurious effects from frequent inhalation of small quantities of acid vapours, or employment in workrooms in which the air is slightly charged with acid, is the accidental sudden inhalation of large quantities of acid gases, which may arise in the manufacture, especially by careless attendance. Formerly this was common in charging the roasting furnaces when the draught in the furnace, on addition of the pyrites, was not strengthened at the same time. This can be easily avoided by artificial regulation of the draught. Accidents through inhalation of acid gases occur further when entering the lead chambers or acid tanks, and in emptying the towers. Heinzerling relates several cases taken from factory inspectors’ reports. Thus, in a sulphuric acid factory the deposit (lead oxysulphate) which had collected on the floor of a chamber was being removed: to effect this the lead chambers were opened at the side. Two of the workers, who had probably been exposed too long to the acid vapours evolved in stirring up the deposit, died a short time after they had finished the work. A similar fatality occurred in cleaning out a nitro-sulphuric acid tank, the required neutralisation of the acid by lime before entering having been omitted. Of the two workers who entered, one died the next day; the other remained unaffected. The deceased had, as the post mortem showed, already suffered previously from pleurisy. A fatality from breathing nitrous fumes is described fully in the report of the Union of Chemical Industry for the year 1905. The worker was engaged with two others in fixing a fan to a lead chamber; the workers omitted to wait for the arrival of the foreman who was to have supervised the operation. Although the men used moist sponges as respirators, one of them inhaled nitrous fumes escaping from the chamber in such quantity that he died the following day. Similar accidents have occurred in cleaning out the Gay-Lussac towers. Such poisonings have repeatedly occurred in Germany. Fatal poisoning is recorded in the report of the Union of Chemical Industry, in the emptying and cleaning of a Gay-Lussac tower despite careful precautions. The tower, filled with coke, had been previously well washed with water, and during the operation of emptying, air had been constantly blown through by means of a Körting’s injector. The affected worker had been in the tower about an hour; two hours later symptoms of poisoning set in which proved fatal in an hour despite immediate medical attention. As such accidents kept on recurring, the Union of Chemical Industry drew up special precautions to be adopted in the emptying of these towers, which are printed in Part III. Naturally, in all these cases it is difficult to say exactly which of the acid gases arising in the production of sulphuric acid was responsible for the poisoning. In the fatal cases cited, probably nitrous fumes played the more important part. Poisoning has occurred in the transport of sulphuric acid. In some of the cases, at all events, gaseous impurities, especially arseniuretted hydrogen, were present. Thus, in the reports of the German Union of Chemical Industry for the year 1901, a worker succumbed through inhalation of poisonous gases in cleaning out a tank waggon for the transport of sulphuric acid. The tank was cleaned of the adhering mud, as had been the custom for years, by a man who climbed into it. No injurious effects had been noted previously at the work, and no further precautions were taken than that one worker relieved another at short intervals, and the work was carried on under supervision. On the occasion in question, however, there was an unusually large quantity of deposit, although the quality of the sulphuric acid was the same, and work had to be continued longer. The worker who remained longest in the tank became ill on his way home and died in hospital the following day; the other workers were only slightly affected. The sulphuric acid used by the firm in question immediately before the accident came from a newly built factory in which anhydrous sulphuric acid had been prepared by a special process. The acid was Glover acid, and it is possible that selenium and arsenic compounds were present in the residues. Arseniuretted hydrogen might have been generated in digging up the mud. Two similar fatalities are described in the report of the same Union for the year 1905. They happened similarly in cleaning out a sulphuric acid tank waggon, and in them the arsenic in the acid was the cause. Preliminary swilling out with water diluted the remainder of the sulphuric acid, but, nevertheless, it acted on the iron of the container. Generation of hydrogen gas is the condition for the reduction of the arsenious acid present in sulphuric acid with formation of arseniuretted hydrogen. In portions of the viscera arsenic was found. Lately in the annual reports of the Union of Chemical Industry for 1908 several cases of poisoning are described which were caused by sulphuric acid. A worker took a sample out of a vessel of sulphuric acid containing sulphuretted hydrogen gas. Instead of using the prescribed cock, he opened the man-hole and put his head inside, inhaling concentrated sulphuretted hydrogen gas. He became immediately unconscious and died. Through ignorance no use was made of the oxygen apparatus. Another fatality occurred through a foreman directing some workers, contrary to the regulations against accidents from nitrous gases, to clean a vessel containing nitric and sulphuric acids. They wore no air helmets: one died shortly after from inhalation of nitrous fumes. Under certain circumstances even the breaking of carboys filled with sulphuric acid may give rise to severe poisoning through inhalation of acid gases. Thus a fatality[1] occurred to the occupier of a workroom next some premises in which sulphuric acid carboys had been accidentally broken. Severe symptoms developed the same night, and he succumbed the next morning in spite of treatment with oxygen. A worker in the factory became seriously ill but recovered. A similar case is described[2] in a factory where concentrated sulphuric acid had been spilt. The workers covered the spot with shavings, which resulted in strong development of sulphur dioxide, leading to unconsciousness in one worker. The frequent observation of the injurious effect of acid gases on the teeth of workers requires mention; inflammation of the eyes of workers also is attributed to the effects of sulphuric acid. Leymann’s statistics show _corrosions and burns_ among sulphuric acid workers to be more than five times that among other classes. Such burns happen most frequently from carelessness. Thus, in the reports of the Union of Chemical Industry for 1901, three severe accidents are mentioned which occurred from use of compressed air. In two cases the acid had been introduced before the compressed air had been turned off; in the third the worker let the compressed air into the vessel and forgot to turn off the inlet valve. Although the valves were provided with lead guards, some of the acid squirted into the worker’s face. In one case complete blindness followed, in a second blindness in one eye, and in the third blindness in one eye and impaired vision of the other. Besides these dangers from the raw material, bye-products, and products of the manufacture, _lead poisoning_ has been reported in the erection and repair of lead chambers. The lead burners generally use a hydrogen flame; the necessary hydrogen is usually made from zinc and sulphuric acid and is led to the iron by a tube. If the zinc and sulphuric acid contain arsenic, the very dangerous arseniuretted hydrogen is formed, which escapes through leakages in the piping, or is burnt in the flame to arsenious acid. Further, the lead burners and plumbers are exposed to the danger of chronic lead poisoning from insufficient observance of the personal precautionary measures necessary to guard against it (see Part III). Those who are constantly engaged in burning the lead sheets and pipes of the chambers suffer not infrequently from severe symptoms. Unfortunately, the work requires skill and experience, and hence alternation of employment is hardly possible. Finally, mention should be made of poisoning by _arseniuretted hydrogen gas_ from vessels filled with sulphuric acid containing arsenic as an impurity, and by sulphuretted hydrogen gas in purifying the acid itself. In the manufacture of liquid _sulphur dioxide_, injury to health can arise from inhalation of the acid escaping from the apparatus. The most frequent cause for such escape of sulphur dioxide is erosion of the walls of the compressor pumps and of the transport vessels, in consequence of the gas being insufficiently dried, as, when moist, it attacks iron. Sulphur dioxide will come up for further consideration when describing the industrial processes giving rise to it, or in which it is used. HYDROCHLORIC ACID, SALTCAKE, AND SODA MANUFACTURE.—The production of hydrochloric acid (HCl), sodium sulphate (Na₂SO₄), and sodium sulphide (Na₂S) forms part of the manufacture of soda (Na₂CO₃) by the Leblanc process. The products first named increase in importance, while the Leblanc soda process is being replaced more and more by the manufacture of soda by the Solvay ammonia process, so much so that on the Continent the latter method predominates and only in England does the Leblanc process hold its ground. Health interests have exercised an important bearing on the development of the industries in question. At first, in the Leblanc process the hydrochloric acid gas was allowed to escape into the atmosphere, being regarded as a useless bye-product. Its destructive action on plant life and the inconvenience caused to the neighbourhood, in spite of erection of high chimneys, demanded intervention. In England the evils led to the enactment of the Alkali Acts—the oldest classical legislative measures bearing on factory hygiene—by which the Leblanc factories were required to condense the vapour by means of its absorption in water, and this solution of the acid is now a highly valued product. And, again, production of nuisance—inconvenience to the neighbourhood through the soda waste—was the main cause of ousting one of the oldest and most generally used methods of chemical industrial production. Although every effort was made to overcome the difficulties, the old classical Leblanc process is gradually but surely yielding place to the modern Solvay process, which has no drawback on grounds of health. We outline next the main features of the _Leblanc soda process_, which includes, as has been mentioned, also the manufacture of hydrochloric acid, sodium sulphate and sulphide. The first part of the process consists in the production of the sulphate from salt and sulphuric acid, during which hydrochloric acid is formed; this is carried out in two stages represented in the following formulæ: 1. NaCl + H₂SO₄ = NaHSO₄ + HCl. 2. NaCl + NaHSO₄ = Na₂SO₄ + HCl. The first stage in which bisulphate is produced is carried out at a moderate heat, the second requires a red heat. The reactions, therefore, are made in a furnace combining a pan and muffle furnace. This saltcake muffle furnace is so arranged that the pan can be shut off from the muffle by a sliding-door (D). The pan (A) and muffle (E) have separate flues for carrying off the hydrochloric acid developed (B, F). First, common salt is treated with sulphuric (Glover) acid in the cast-iron pan. When generation of hydrochloric acid vapour has ceased, the sliding-door is raised and the partly decomposed mixture is pushed through into the muffle, constructed of fire-resisting bricks and tiles, and surrounded by the fire gases. While the muffle is being raised to red heat, the sulphate must be repeatedly stirred with a rake in order, finally, while still hot and giving off acid vapour, to be drawn out at the working doors into iron boxes provided with doors, where the material cools. The acid vapour given off when cooling is drawn through the top of the box into the furnace. [Illustration: FIG. 3.—Saltcake Muffle Furnace—Section _(after Ost_) A Pan; B, F Pipes for hydrochloric acid vapour; D Shutter; E Muffle, O Coke fire.] Mechanical stirrers, despite their advantage from a health point of view, have not answered because of their short life. The valuable bye-product of the sulphate process, _hydrochloric acid_, is led away separately from the pan and the muffle, as is seen, into one absorption system. The reason of the separation is that the gas from the pan is always the more concentrated. The arrangement of the absorbing apparatus is illustrated in fig. 4. [Illustration: FIG. 4A.—Preparation of Hydrochloric Acid—Plan (_after Lueger_) A, A´ Earthenware pipes B, B´ Sandstone cooling towers C, C Series of Woulff’s bottles D, E Condenser wash towers FIG. 4B.—Elevation] The gases are led each through earthenware pipes or channels of stone pickled with tar (A´), first into small towers of Yorkshire flags (B), where they are cooled and freed from flue dust and impurities (sulphuric acid) by washing. They are next led through a series (over fifty) of Woulff bottles (bombonnes) one metre high, made of acid-resisting stoneware. The series is laid with a slight inclination towards the furnace, and water trickles through so that the gases coming from the wash towers are brought into contact with water in the one case already almost saturated, whilst the gas which is poorest in hydrochloric acid meets with fresh water. From the bombonne situated next to the wash tower the prepared acid is passed as a rule through another series. The last traces of hydrochloric acid are then removed by leading the gases from the Woulff bottles up two water towers of stoneware (D and E), which are filled partly with earthenware trays and partly with coke; above are tanks from which the water trickles down over the coke. The residual gases from both sets of absorbing apparatus now unite in a large Woulff bottle before finally being led away through a duct to the chimney stack. Less frequently absorption of hydrochloric acid is effected without use of Woulff bottles, principally in wash towers such as the Lunge-Rohrmann plate tower. In the purification of hydrochloric acid, de-arsenicating by sulphuretted hydrogen or by barium sulphide, &c., and separation of sulphuric acid by addition of barium chloride, have to be considered. Another method for production of sulphate and hydrochloric acid, namely, the Hargreaves process, is referred to later. We return now to the further working up of the sodium sulphate into sulphide and soda. The conversion of the sulphate into soda by the Leblanc method is effected by heating with coal and calcium carbonate, whereby, through the action of the coal, sodium sulphide forms first, which next with the calcium carbonate becomes converted into sodium carbonate and calcium sulphide. The reactions are: Na₂SO₄ + 2C = Na₂S + 2CO₂ Na₂S + CaCO₃ = Na₂CO₃ + CaS CaCO₃ + C = CaO + 2CO. The reactions are carried out in small works in open reverberatory furnaces having two platforms on the hearth, and with continuous raking from one to the other which, as the equations show, cause escape of carbonic acid gas and carbonic oxide. Such handworked furnaces, apart from their drawbacks on health grounds, have only a small capacity, and in large works their place is taken by revolving furnaces—closed, movable cylindrical furnaces—in which handwork is replaced by the mechanical revolution of the furnace and from which a considerably larger output and a product throughout good in quality are obtained. The _raw soda_ thus obtained in the black ash furnace is subjected to lixiviation by water in iron tanks in which the impurities or tank waste (see below) are deposited. The crude soda liquor so obtained is then further treated and converted into calcined soda, crystal soda, or caustic soda. In the production of calcined soda the crude soda liquor is first purified (‘oxidised’ and ‘carbonised’) by blowing through air and carbonic acid gas, pressed through a filter press, and crystallised by evaporation in pans and calcined, i.e. deprived of water by heat. [Illustration: FIG. 5.—Revolving Black Ash Furnace—Elevation (_after Lueger_) A Firing hearth; B Furnace; C Dust box.] _Crystal soda_ is obtained from well-purified tank liquor by crystallising in cast-iron vessels. Caustic soda is obtained by introducing lime suspended in iron cages into the soda liquor in iron caustic pots, heating with steam, and agitating by blowing in air. The resulting clear solution is drawn off and evaporated in cast-iron pans. As already mentioned, the _tank waste_ in the Leblanc process, which remains behind—in amount about equal to the soda produced after lixiviation of the raw soda with water—constitutes a great nuisance. It forms mountains round the factories, and as it consists principally of calcium sulphide and calcium carbonate, it easily weathers under the influence of air and rain, forming soluble sulphur compounds and developing sulphuretted hydrogen gas—an intolerable source of annoyance to the district. At the same time all the sulphur introduced into the industry as sulphuric acid is lost in the tank waste. This loss of valuable material and the nuisance created led to attempts—partially successful—to recover the sulphur. The best results are obtained by the Chance-Claus method, in which the firebrick ‘Claus-kiln’ containing ferric oxide (previously heated to dull redness) is used. In this process calcium sulphide is acted on by carbonic acid with evolution of gas so rich in sulphuretted hydrogen that it can be burnt to sulphur dioxide and used in the lead chambers for making sulphuric acid. Sulphur also as such is obtained by the method. These sulphur-recovery processes which have hardly been tried on the Continent—only the United Alkali Company in England employs the Chance-Claus on a large scale—were, as has been said, not in a position to prevent the downfall of the Leblanc soda industry. Before describing briefly the Solvay method a word is needed as to other processes for manufacture of sulphate and hydrochloric acid. _Hargreaves’ process_ produces sodium sulphate (without previous conversion of sulphur dioxide into sulphuric acid) directly by the passage of gases from the pyrites burners, air and steam, through salt blocks placed in vertical cast-iron retorts, a number of which are connected in series. A fan draws the gases through the system and leads the hydrochloric acid fumes to the condenser. Sodium sulphate is used in the manufacture of glass, ultramarine, &c. Further, the sulphate is converted into Glauber’s salts by dissolving the anhydrous sulphate obtained in the muffle furnace, purifying with lime, and allowing the clear salt solution to crystallise out in pans. A further use of the sulphate is the preparation of sodium sulphide, which is effected (as in the first part of the Leblanc soda process) by melting together sulphate and coal in a reverberatory furnace. If the acid sulphate (bisulphate) or sulphate containing bisulphate is used much sulphur dioxide gas comes off. The mass is then lixiviated in the usual soda liquor vats and the lye either treated so as to obtain crystals or evaporated to strong sodium sulphide which is poured like caustic soda into metal drums where it solidifies. In _Solvay’s ammonia soda process_ ammonia recovered from the waste produced in the industry is led into a solution of salt until saturation is complete. This is effected generally in column apparatus such as is used in distillation of spirit. The solution is then driven automatically by compressed air to the carbonising apparatus in which the solution is saturated with carbonic acid; this apparatus is a cylindrical tower somewhat similar to the series of vessels used for saturating purposes in sugar factories through which carbonic acid gas passes. In this process crystalline bi-carbonate of soda is first formed, which is separated from the ammoniacal mother liquor by filtration, centrifugalisation, and washing. The carbonate is then obtained by heating (calcining in pans), during which carbonic acid gas escapes, and this, together with the carbonic acid produced in the lime kilns, is utilised for further carbonisation again. The lime formed during the production of carbonic acid in the lime kilns serves to drive the ammonia out of the ammoniacal mother liquor, so that the ammonia necessary for the process is recovered and used over and over again. The waste which results from the action of the lime on the ammonium chloride liquor is harmless—calcium chloride liquor. The _electrolytic_ manufacture of soda from salt requires mention, in which chlorine (at the anode) and caustic soda (at the cathode) are formed; the latter is treated with carbonic acid to make soda. EFFECTS ON HEALTH.—Leymann’s observations show that in the department concerned with the Leblanc soda process and production of sodium sulphide, relatively more sickness is noted than, for example, in the manufacture of sulphuric and nitric acids. In the preparation of the sulphate, possibility of injury to health or poisoning arises from the fumes containing hydrochloric or sulphuric acid in operations at the muffle furnace; in Hargreaves’ process there may be exposure to the effect of sulphur dioxide. Hydrochloric and sulphuric acid vapours can escape from the muffle furnace when charging, from leakages in it, and especially when withdrawing the still hot sulphate. Large quantities of acid vapours escape from the glowing mass, especially if coal is not added freely and if it is not strongly calcined. Persons employed at the saltcake furnaces suffer, according to Jurisch, apart from injury to the lungs, from defective teeth. The teeth of English workers especially, it is said, from the practice of holding flannel in their mouths with the idea of protecting themselves from the effect of the vapours, are almost entirely eroded by the action of the hydrochloric acid absorbed by the saliva. Hydrochloric acid vapour, further, can escape from the absorbing apparatus if this is not kept entirely sealed, and the hydrochloric acid altogether absorbed—a difficult matter. Nevertheless, definite acute industrial poisoning from gaseous hydrochloric acid is rare, no doubt because the workers do not inhale it in concentrated form. Injury to the skin from the acid absorbed in water may occur in filling, unloading, and transport, especially when in carboys, but the burns, if immediately washed, are very slight in comparison with those from sulphuric or nitric acids. Injury to health or inconvenience from sulphuretted hydrogen is at all events possible in the de-arsenicating process by means of sulphuretted hydrogen gas. At the saltcake furnace when worked by hand the fumes containing carbonic oxide gas may be troublesome. In the production of caustic soda severe corrosive action on the skin is frequent. Leymann found that 13·8 per cent. of the persons employed in the caustic soda department were reported as suffering from burns, and calls attention to the fact that on introducing the lime into the hot soda lye the contents of the vessel may easily froth over. Heinzerling refers to the not infrequent occurrence of eye injuries in the preparation of caustic soda, due to the spurting of lye or of solid particles of caustic soda. The tank waste gives rise, as already stated, to inconvenience from the presence of sulphuretted hydrogen. In the recovery of the sulphur and treatment of the tank waste, sulphuretted hydrogen and sulphur dioxide gases are evolved. According to Leymann, workers employed in removing the waste and at the lye vats frequently suffer from inflammation of the eyes. Further, disturbance of digestion has been noted in persons treating the tank waste, which Leymann attributes to the unavoidable development of sulphuretted hydrogen gas. In the manufacture of sodium sulphide similar conditions prevail. Leymann found in this branch relatively more cases of sickness than in any other; diseases of the digestive tract especially appeared to be more numerous. Leymann makes the suggestion that occurrence of disease of the digestive organs is either favoured by sodium sulphide when swallowed as dust, or that here again sulphuretted hydrogen gas plays a part. Further corrosive effect on the skin and burns may easily arise at work with the hot corrosive liquor. In the Solvay ammonia process ammonia and carbonic acid gas are present, but, so far as I know, neither injury to health nor poisoning have been described among persons employed in the process. Indeed, the view is unanimous that this method of manufacture with its technical advantages has the merit also of being quite harmless. As may be seen from the preceding description of the process there is no chance of the escape of the gases named into the workrooms. USE OF SULPHATE AND SULPHIDE _Ultramarine_ is made from a mixture of clay, sulphate (Glauber’s salts), and carbon—sulphate ultramarine; or clay, sulphur, and soda—soda ultramarine. These materials are crushed, ground, and burnt in muffle furnaces. On heating the mass in the furnace much sulphur dioxide escapes, which is a source of detriment to the workmen and the neighbourhood. _Sulphonal_ (CH₃)₂C(SO₂C₂H₅)₂, diethylsulphone dimethylmethane, used medically as a hypnotic, is obtained from mercaptan formed by distillation of ethyl sulphuric acid with sodium or potassium sulphide. The mercaptan is converted into mercaptol, and this by oxidation with potassium permanganate into sulphonal. The volatile mercaptan has a most disgusting odour, and clings for a long time even to the clothes of those merely passing through the room. _Diethyl sulphate_ ((C₂H₅)₂SO₄).—Diethyl sulphate obtained by the action of sulphuric acid on alcohol has led to poisoning characterised by corrosive action on the respiratory tract.[1] As the substance in the presence of water splits up into sulphuric acid and alcohol, this corrosive action is probably due to the acid. It is possible, however, that the molecule of diethyl sulphate as such has corrosive action. Contact with diethyl sulphate is described as having led to fatal poisoning.[2] A chemist when conducting a laboratory experiment dropped a glass flask containing about 40 c.c. of diethyl sulphate, thereby spilling some over his clothes. He went on working, and noticed burns after some time, quickly followed by hoarseness and pain in the throat. He died of severe inflammation of the lungs. A worker in another factory was dropping diethyl sulphate and stirring it into an at first solid, and later semi-liquid, mass for the purpose of ethylating a dye stuff. In doing so he was exposed to fumes, and at the end of the work complained of hoarseness and smarting of the eyes. He died of double pneumonia two days later. Post mortem very severe corrosive action on the respiratory tract was found, showing that the diethyl sulphuric acid had decomposed inside the body and that nascent sulphuric acid had given rise to the severe burns. The principal chemist who had superintended the process suffered severely from hoarseness at night, but no serious consequences followed. It is stated also that workmen in chemical factories coming into contact with the fumes of diethyl sulphate ester suffer from eye affections.[3] CHLORINE, CHLORIDE OF CALCIUM, AND CHLORATES MANUFACTURE.—The older processes depend on the preparation of chlorine and hydrochloric acid by an oxidation process in which the oxidising agent is either a compound rich in oxygen—usually common manganese dioxide (pyrolusite)—or the oxygen of the air in the presence of heated copper chloride (as catalytic agent). The former (Weldon process) is less used now than either the latter (Deacon process) or the electrolytic manufacture of chlorine. In the _Weldon process_ from the still liquors containing manganous chloride the manganese peroxide is regenerated, and this so regenerated Weldon mud, when mixed with fresh manganese dioxide, is used to initiate the process. This is carried out according to the equations: MnO₂ + 4HCl = MnCl₄ + 2H₂O MnCl₄ = MnCl₂ + Cl₂. [Illustration: FIG. 6.—Preparation of Chlorine—Diaphragm Method (_after Ost_)] Hydrochloric acid is first introduced into the chlorine still (vessels about 3 m. in height, of Yorkshire flag or fireclay), next the Weldon mud gradually, and finally steam to bring the whole to boiling; chlorine comes off in a uniform stream. The manganous chloride still liquor is run into settling tanks. The regeneration of the manganous chloride liquor takes place in an oxidiser which consists of a vertical iron cylinder in which air is blown into the heated mixture of manganous chloride and milk of lime. The dark precipitate so formed, ‘Weldon mud,’ as described, is used over again, while the calcium chloride liquor runs away. The _Deacon process_ depends mainly on leading the stream of hydrochloric acid gas evolved from a saltcake pot mixed with air and heated into a tower containing broken bricks of the size of a nut saturated with copper chloride. Chlorine is evolved according to the equation: 2HCl + O = 2Cl + H₂O. [Illustration: FIG. 7.—Preparation of Chlorine—Bell Method (_after Ost_)] The _electrolytic production_ of chlorine with simultaneous production of _caustic alkali_ is increasing and depends on the splitting up of alkaline chlorides by a current of electricity. The chlorine evolved at the anode and the alkaline liquor formed at the cathode must be kept apart to prevent secondary formation of hypochlorite and chlorate (see below). This separation is generally effected in one of three ways: (1) In the diaphragm process (Griesheim-Elektron chemical works) the anode and cathode are kept separate by porous earthenware diaphragms arranged as illustrated in fig. 6. The anode consists of gas carbon, or is made by pressing and firing a mixture of charcoal and tar; it lies inside the diaphragm. The chlorine developed in the anodal cell is carried away by a pipe. The metal vessel serves as the cathode. The alkali, which, since it contains chloride, is recovered as caustic soda after evaporation and crystallisation, collects in the cathodal space lying outside the diaphragm. (2) By the Bell method (chemical factory at Aussig) the anodal and cathodal fluids, which keep apart by their different specific weights, are separated by a stoneware bell; the poles consist of sheet iron and carbon. The containing vessel is of stoneware. (3) In the mercury process (England) sodium chloride is electrolysed without a diaphragm, mercury serving as the cathode. This takes up the sodium, which is afterwards recovered from the amalgam formed by means of water. If _chlorate_ or _hypochlorite_ is to be obtained electrolytically, electrodes of the very resistant but expensive platinum iridium are used without a diaphragm. Chlorine is developed—not free, but combined with the caustic potash. The bleaching fluid obtained electrolytically in this way is a rival of bleaching powder. _Bleaching powder_ is made from chlorine obtained by the Weldon or Deacon process. Its preparation depends on the fact that calcium hydrate takes up chlorine in the cold with formation of calcium hypochlorite after the equation: 2Ca(OH)₂ + 4Cl = Ca(ClO)₂ + CaCl₂ + 2H₂O. The resulting product contains from 35 to 36 per cent. chlorine, which is given off again when treated with acids. The preparation of chloride of lime takes place in bleaching powder chambers made of sheets of lead and Yorkshire flagstones. The lime is spread out on the floors of these and chlorine introduced. Before the process is complete the lime must be turned occasionally. In the manufacture of bleaching powder from Deacon chlorine, Hasenclever has constructed a special cylindrical apparatus (fig. 8), consisting of several superimposed cast-iron cylinders in which are worm arrangements carrying the lime along, while chlorine gas passes over in an opposite direction. This continuous process is, however, only possible for the Deacon chlorine strongly diluted with nitrogen and oxygen and not for undiluted Weldon gas. _Liquid chlorine_ can be obtained by pressure and cooling from concentrated almost pure Weldon chlorine gas. _Potassium chlorate_, which, as has been said, is now mostly obtained electrolytically, was formerly obtained by passing Deacon chlorine into milk of lime and decomposing the calcium chlorate formed by potassium chloride. Chlorine and chloride of lime are used for bleaching; chlorine further is used in the manufacture of colours; chloride of lime as a mordant in cloth printing and in the preparation of chloroform; the chlorates are oxidising agents and used in making safety matches. The manufacture of organic chlorine products will be dealt with later. [Illustration: FIG. 8.—Preparation of Bleaching Powder. Apparatus of Hasenclever (_after Ost_) A Hopper for slaked lime; W Worm conveying lime; Z Toothed wheels; K Movable covers; C Entrance for chlorine gas; D Pipe for escape of chlorine-free gas; B Outlet shoot for bleaching powder] EFFECTS ON HEALTH.—In these industries the possibility of injury to health and poisoning by inhalation of chlorine gas is prominent. Leymann has shown that persons employed in the manufacture of chlorine and bleaching powder suffer from diseases of the respiratory organs 17·8 per cent., as contrasted with 8·8 per cent. in other workers: and this is without doubt attributable to the injurious effect of chlorine gas, which it is hardly possible to avoid despite the fact that Leymann’s figures refer to a model factory. But the figures show also that as the industry became perfected the number of cases of sickness steadily diminished. Most cases occur from unsatisfactory conditions in the production of chloride of lime, especially if the chloride of lime chambers leak, if the lime is turned over while the chlorine is being let in, by too early entrance into chambers insufficiently ventilated, and by careless and unsuitable methods of emptying the finished bleaching powder. The possibility of injury is naturally greater from the concentrated gas prepared by the Weldon process than from the diluted gas of the Deacon process—the more so as in the latter the bleaching powder is made in the Hasenclever closed-in cylindrical apparatus in which the chlorine is completely taken up by the lime. The safest process of all is the electrolytic, as, if properly arranged, there should be no escape of chlorine gas. The chlorine developed in the cells (when carried out on the large scale) is drawn away by fans and conducted in closed pipes to the place where it is used. Many researches have been published as to the character of the skin affection well known under the name of _chlorine rash_ (chlorakne). Some maintain that it is not due to chlorine at all, but is an eczema set up by tar. Others maintain that it is due to a combined action of chlorine and tar. Support to this view is given by the observation that cases of chlorine rash, formerly of constant occurrence in a factory for electrolytic manufacture of chlorine, disappeared entirely on substitution of magnetite at the anode for carbon.[1] The conclusion seems justified that the constituents of the carbon or of the surrounding material set up the condition. Chlorine rash has been observed in an alkali works where chlorine was not produced electrolytically, and under conditions which suggested that compounds of tar and chlorine were the cause. In this factory for the production of salt cake by the Hargreaves’ process cakes of rock salt were prepared and, for the purpose of drying, conveyed on an endless metal band through a stove. To prevent formation of crusts the band was tarred. The salt blocks are decomposed in the usual way by sulphur dioxide, steam, and oxygen of the air, and the hydrochloric acid vapour led through Deacon towers in which the decomposition of the hydrochloric acid into chlorine and water is effected by metal salts in the manner characteristic of the Deacon process. These salts are introduced in small earthenware trays which periodically have to be removed and renewed; the persons engaged in doing this were those affected. The explanation was probably that the tar sticking to the salt blocks distilled in the saltcake furnaces and formed a compound with the chlorine which condensed on the earthenware trays. When contact with these trays was recognised as the cause, the danger was met by observance of the greatest cleanliness in opening and emptying the Deacon towers. Leymann[2] is certain that the rash is due to chlorinated products which emanate from the tar used in the construction of the cells. And the affection has been found to be much more prevalent when the contents of the cells are emptied while the contents are still hot than when they are first allowed to get cold. Lehmann[3] has approached the subject on the experimental side, and is of opinion that probably chlorinated tar derivatives (chlorinated phenols) are the cause of the trouble. Both he and Roth think that the affection is due not to external irritation of the skin, but to absorption of the poisonous substances into the system and their elimination by way of the glands of the skin. In the section on manganese poisoning detailed reference is made to the form of illness recently described in persons employed in drying the regenerated Weldon mud. Mercurial poisoning is possible when mercury is used in the production of chlorine electrolytically. In the manufacture of chlorates and hypochlorite, bleaching fluids, &c., injury to health from chlorine is possible in the same way as has been described above. OTHER CHLORINE COMPOUNDS. BROMINE, IODINE, AND FLUORINE Chlorine is used for the production of a number of organic chlorine compounds, and in the manufacture of bromine and iodine, processes which give rise to the possibility of injury to health and poisoning by chlorine; further, several of the substances so prepared are themselves corrosive or irritating or otherwise poisonous. Nevertheless, severe poisoning and injurious effects can be almost entirely avoided by adoption of suitable precautions. In the factory to which Leymann’s figures refer, where daily several thousand kilos of chlorine and organic chlorine compounds are prepared, a relatively very favourable state of health of the persons employed was noted. At all events the preparation of chlorine by the electrolytic process takes place in closed vessels admirably adapted to avoid any escape of chlorine gas except as the result of breakage of the apparatus or pipes. When this happens, however, the pipes conducting the gas can be immediately disconnected and the chlorine led into other apparatus or into the bleaching powder factory. As such complete precautionary arrangements are not everywhere to be found, we describe briefly the most important of the industries in question and the poisoning recognised in them. _Chlorides of phosphorus._—By the action of dry chlorine on an excess of heated amorphous phosphorus, trichloride is formed (PCl₃), a liquid having a sharp smell and causing lachrymation, which fumes in the air, and in presence of water decomposes into phosphorous acid and hydrochloric acid. On heating with dry oxidising substances it forms phosphorus oxychloride (see below), which is used for the production of acid chlorides. By continuous treatment with chlorine it becomes converted into phosphorus pentachloride (PCl₅), which also is conveniently prepared by passing chlorine through a solution of phosphorus in carbon bisulphide, the solution being kept cold; it is crystalline, smells strongly, and attacks the eyes and lungs. With excess of water it decomposes into phosphoric acid and hydrochloric acid: with slight addition of water it forms phosphorus oxychloride (POCl₃). On the large scale this is prepared by reduction of phosphate of lime in the presence of chlorine with carbon or carbonic oxide. Phosphorus oxychloride, a colourless liquid, fumes in the air and is decomposed by water into phosphoric acid and hydrochloric acid. In the preparation of chlorides of phosphorus, apart from the danger of chlorine gas and hydrochloric acid, the poisonous effect of phosphorus and its compounds (see Phosphorus) and even of carbon disulphide (as the solvent of phosphorus) and of carbonic oxide (in the preparation of phosphorus oxychloride) have to be taken into account. Further, the halogen compounds of phosphorus exert irritant action on the eyes and lungs similar to chloride of sulphur as a result of their splitting up on the moist mucous membranes into hydrochloric acid and an oxyacid of phosphorus.[4] Unless, therefore, special measures are taken, the persons employed in the manufacture of phosphorus chlorides suffer markedly from the injurious emanations given off.[5] Leymann[6] mentions one case of poisoning by phosphorus chloride as having occurred in the factory described by him. By a defect in the outlet arrangement phosphorus oxychloride flowed into a workroom. Symptoms of poisoning (sensation of suffocation, difficulty of breathing, lachrymation, &c.) at once attacked the occupants; before much gas had escaped, the workers rushed out. Nevertheless, they suffered from severe illness of the respiratory organs (bronchial catarrh and inflammation of the lungs, with frothy, blood-stained expectoration, &c.).[7] _Chlorides of sulphur._—Monochloride of sulphur (S₂Cl₂) is made by passing dried, washed chlorine gas into molten heated sulphur. The oily, brown, fuming liquid thus made is distilled over into a cooled condenser and by redistillation purified from the sulphur carried over with it. Sulphur monochloride can take up much sulphur, and when saturated is used in the vulcanisation of indiarubber, and, further, is used to convert linseed and beetroot oil into a rubber substitute. Monochloride of sulphur is decomposed by water into sulphur dioxide, hydrochloric acid, and sulphur. By further action of chlorine on the monochloride, sulphur dichloride (SCl₂) and the tetrachloride (SCl₄) are formed. In its preparation and use (see also Indiarubber Manufacture) the injurious action of chlorine, of hydrochloric acid, and of sulphur dioxide comes into play. The monochloride has very irritating effects. Leymann cites an industrial case of poisoning by it. In the German factory inspectors’ reports for 1897 a fatal case is recorded. The shirt of a worker became saturated with the material owing to the bursting of a bottle. First aid was rendered by pouring water over him, thereby increasing the symptoms, which proved fatal the next day. Thus the decomposition brought about by water already referred to aggravated the symptoms. _Zinc chloride_ (ZnCl₂) is formed by heating zinc in presence of chlorine. It is obtained pure by dissolving pure zinc in hydrochloric acid and treating this solution with chlorine. Zinc chloride is obtained on the large scale by dissolving furnace calamine (zinc oxide) in hydrochloric acid. Zinc chloride is corrosive. It is used for impregnating wood and in weighting goods. Besides possible injury to health from chlorine and hydrogen chloride, risk of arseniuretted hydrogen poisoning is present in the manufacture if the raw materials contain arsenic. Eulenburg considers that in soldering oppressive zinc chloride fumes may come off if the metal to be soldered is first wiped with hydrochloric acid and then treated with the soldering iron. _Rock salt._—Mention may be made that even to salt in combination with other chlorides (calcium chloride, magnesium chloride, &c.) injurious effects are ascribed. Ulcers and perforation of the septum of the nose in salt-grinders and packers who were working in a room charged with salt dust are described.[8] These effects are similar to those produced by the bichromates. Organic Chlorine Compounds _Carbon oxychloride_ (COCl₂, carbonyl dichloride, phosgene) is produced by direct combination of chlorine and carbonic oxide in presence of animal charcoal. Phosgene is itself a very poisonous gas which, in addition to the poisonous qualities of carbonic oxide (which have to be borne in mind in view of the method of manufacture), acts as an irritant of the mucous membranes. Commercially it is in solution in toluene and xylene, from which the gas is readily driven off by heating. It is used in the production of various colours, such as crystal violet, Victoria blue, auramine, &c. A fatal case of phosgene gas poisoning in the report of the Union of Chemical Industry for 1905 deserves mention. The phosgene was kept in a liquefied state in iron bottles provided with a valve under 2·3 atm. pressure. The valve of one of these bottles leaked, allowing large escape into the workroom. Two workers tried but failed to secure the valve. The cylinder was therefore removed by a worker, by order of the manager, and placed in a cooling mixture, as phosgene boils at 8° C. The man in question wore a helmet into which air was pumped from the compressed air supply in the factory. As the helmet became obscured through moisture after five minutes the worker took it off. A foreman next put on the cleaned mask, and kept the cylinder surrounded with ice and salt for three-quarters of an hour, thus stopping the escape of gas. Meanwhile, the first worker had again entered the room, wearing a cloth soaked in dilute alcohol before his mouth, in order to take a sack of salt to the foreman. An hour and a half later he complained of being very ill, became worse during the night, and died the following morning. Although the deceased may have been extremely susceptible, the case affords sufficient proof of the dangerous nature of the gas, which in presence of moisture had decomposed into carbonic acid and hydrochloric acid; the latter had acutely attacked the mucous membrane of the respiratory passages and set up fatal bronchitis. Further, it was found that the leaden plugs of the valves had been eroded by the phosgene. Three further cases of industrial phosgene poisoning have been reported,[9] one a severe case in which there was bronchitis with blood-stained expectoration, great dyspnœa, and weakness of the heart’s action. The affected person was successfully treated with ether and oxygen inhalations. Phosgene may act either as the whole molecule, or is inhaled to such degree that the carbonic oxide element plays a part. In another case of industrial phosgene poisoning the symptoms were those of severe irritation of the bronchial mucous membrane and difficulty of breathing.[10] The case recovered, although sensitiveness of the air passages lasted a long time. _Carbon chlorine compounds_ (_aliphatic series_).—_Methyl chloride_ (CH₃Cl) or chlormethane is prepared from methyl alcohol and hydrochloric acid (with chloride of zinc) or methyl alcohol, salt, and sulphuric acid. It is prepared in France on a large scale from beetroot _vinasse_ by dry distillation of the evaporation residue. The distillate, which contains methyl alcohol, trimethylamine, and other methylated amines, is heated with hydrochloric acid; the methyl chloride so obtained is purified, dried and compressed. It is used in the preparation of pure chloroform, in the coal-tar dye industry, and in surgery (as a local anæsthetic). In the preparation of methyl chloride there is risk from methyl alcohol, trimethylamine, &c. Methyl chloride itself is injurious to health. _Methylene chloride_ (CH₂Cl₂, dichlormethane) is prepared in a similar way. It is very poisonous. _Carbon tetrachloride_ (CCl₄, tetrachlormethane) is technically important. It is prepared by passing chlorine gas into carbon bisulphide with antimony or aluminium chloride. Carbon tetrachloride is a liquid suitable for the extraction of fat or grease (as in chemical cleaning), and has the advantage of being non-inflammable. Carbon tetrachloride, so far as its poisonous qualities are concerned, is to be preferred to other extractives (see Carbon Bisulphide, Benzine, &c.); for the rest it causes unconsciousness similar to chloroform. When manufactured industrially, in addition to the poisonous effect of chlorine, the poisonous carbon bisulphide has also to be borne in mind. _Ethyl chloride_ (C₂H₅Cl) is made in a way analogous to methyl chloride by the action of hydrochloric acid on ethyl alcohol and chloride of zinc. It is used in medicine as a narcotic. _Monochloracetic acid._—In the preparation of monochloracetic acid hydrochloric acid is developed in large quantity. From it and anthranilic acid artificial indigo is prepared (according to Heuman) by means of caustic potash. _Chloral_ (CCl₃CHO, trichloracetaldehyde) is produced by chlorinating alcohol. Chloral is used in the preparation of pure chloroform and (by addition of water) of chloral hydrate (trichloracetaldehyde hydrate), the well-known soporific. _Chloroform_ (CHCl₃, trichlormethane).—Some methods for the preparation of chloroform have been already mentioned (Chloral, Methyl Chloride). Technically it is prepared by distillation of alcohol or acetone with bleaching powder. The workers employed are said to be affected by the stupefying vapours. Further, there is the risk of chlorine gas from use of chloride of lime. _Chloride of nitrogen_ (NCl₃) is an oily, volatile, very explosive, strongly smelling substance, which irritates the eyes and nose violently and is in every respect dangerous; it is obtained from the action of chlorine or hypochlorous acid on sal-ammoniac. The poisonous nature of these substances may come into play. Risk of formation of chloride of nitrogen can arise in the production of gunpowder from nitre containing chlorine. _Cyanogen chloride_ (CNCl).—Cyanogen chloride is made from hydrocyanic acid or cyanide of mercury and chlorine. Cyanogen chloride itself is an extremely poisonous and irritating gas, and all the substances from which it is made are also poisonous. According to Albrecht cyanogen chloride can arise in the preparation of red prussiate of potash (by passage of chlorine gas into a solution of the yellow prussiate) if the solution is treated with chlorine in excess; the workers may thus be exposed to great danger. _Chlorobenzene._—In his paper referred to Leymann cites three cases of poisoning by chlorobenzene, one by dinitrochlorobenzene, and, further, three cases of burning by chlorobenzene and one by benzoyl chloride (C₆H₅COCl). The last named is made by treating benzaldehyde with chlorine, and irritates severely the mucous membranes, while decomposing into hydrochloric acid and benzoic acid.[11] Benzal chloride (C₆H₅CHCl₂), benzo trichloride (C₆H₅CCl₃), and benzyl chloride (C₆H₅CH₂Cl) are obtained by action of chlorine on boiling toluene. The vapours of these volatile products irritate the respiratory passages. In the manufacture there is risk from the effect of chlorine gas and toluene vapour (see Benzene, Toluene). Leymann[12] describes in detail six cases of poisoning in persons employed in a chlorobenzene industry, of which two were due to nitrochlorobenzene. Symptoms of poisoning—headache, cyanosis, fainting, &c.—were noted in a person working for three weeks with chlorobenzene.[13] In Lehmann’s opinion chlorine rash, the well-recognised skin affection of chlorine workers, may be due to contact with substances of the chlorbenzol group.[14] _Iodine and iodine compounds._—Formerly iodine was obtained almost exclusively from the liquor formed by lixiviation of the ash of seaweed (kelp, &c.); now the principal sources are the mother liquors from Chili saltpetre and other salt industries. From the concentrated liquor the iodine is set free by means of chlorine or oxidising substances and purified by distillation and sublimation. Iodine is used for the preparation of photographic and pharmaceutical preparations, especially iodoform (tri-iodomethane, CHI₃), which is made by acting with iodine and caustic potash on alcohol, aldehyde, acetone, &c. Apart from possible injurious action of chlorine when used in the preparation of iodine, workers are exposed to the possibility of chronic iodine poisoning. According to Ascher[15] irritation effects, nervous symptoms, and gastric ulceration occur in iodine manufacture and use. He considers that bromide of iodine used in photography produces these irritating effects most markedly. Layet and also Chevallier in older literature have made the same observations. The Swiss Factory Inspectors’ Report for 1890-1 describes two acute cases of iodine poisoning in a factory where organic iodine compounds were made; one terminated fatally (severe cerebral symptoms, giddiness, diplopia, and collapse). _Bromine and bromine compounds._—Bromine is obtained (as in the case of iodine) principally from the mother liquors of salt works (especially Stassfurt saline deposits) by the action of chlorine or nascent oxygen on the bromides of the alkalis and alkaline earths in the liquors. They are chiefly used in photography (silver bromide), in medicine (potassium bromide, &c.), and in the coal-tar dye industry. The danger of bromine poisoning (especially of the chronic form) is present in its manufacture and use, but there is no positive evidence of the appearance of the bromine rash among the workers. On the other hand, instances are recorded of poisoning by methyl bromide, and the injurious effect of bromide of iodine has been referred to. _Methyl iodide and methyl bromide._—Methyl iodide (CH₃I), a volatile fluid, is obtained by distillation of wood spirit with amorphous phosphorus and iodine; it is used in the production of methylated tar colours and for the production of various methylene compounds. Grandhomme describes, in the paper already referred to, six cases, some very severe, of poisoning by the vapour of methyl iodide among workers engaged in the preparation of antipyrin, which is obtained by the action of aceto-acetic ether on phenyl hydrazine, treatment of the pyrazolone so obtained with methyl iodide, and decomposition of the product with caustic soda. A case of methyl iodide poisoning is described in a factory operative, who showed symptoms similar to those described for methyl bromide except that the psychical disturbance was more marked.[16] Three cases of methyl bromide (CH₃Br) poisoning are described in persons preparing the compound.[17] One of these terminated fatally. There is some doubt as to whether these cases were really methyl bromide poisoning. But later cases of methyl bromide poisoning are known, and hence the dangerous nature of this chemical compound is undoubted. Thus the Report of the Union of Chemical Industry for 1904 gives the following instance: Two workers who had to deal with an ethereal solution of methyl bromide became ill with symptoms of alcoholic intoxication. One suffered for a long time from nervous excitability, attacks of giddiness, and drowsiness. Other cases of poisoning from methyl bromide vapour are recorded with severe nervous symptoms and even collapse. _Fluorine compounds._—_Hydrogen fluoride_ (HFl) commercially is a watery solution, which is prepared by decomposition of powdered fluorspar by sulphuric acid in cast-iron vessels with lead hoods. The escaping fumes are collected in leaden condensers surrounded with water; sometimes to get a very pure product it is redistilled in platinum vessels. Hydrogen fluoride is used in the preparation of the fluorides of antimony, of which antimony fluoride ammonium sulphate (SbFl₃(NH₄)₂SO₄) has wide use in dyeing as a substitute for tartar emetic. It is produced by dissolving oxide of antimony in hydrofluoric acid with addition of ammonium sulphate and subsequent concentration and crystallisation. Hydrofluoric acid is used for etching glass (see also Glass Industry). In brewing, an unpurified silico-fluoric acid mixed with silicic acid, clay, oxide of iron, and oxide of zinc called Salufer is used as a disinfectant and preservative. _Hydrofluoric acid and silicofluoric acid_ (H₂SiFl₆) arise further in the superphosphate industry by the action of sulphuric acid on the phosphorites whereby silicofluoric acid is obtained as a bye-product (see also Manufacture of Artificial Manure). Hydrofluoric acid and its derivatives both in their manufacture and use and in the superphosphate industry affect the health of the workers. If hydrogen fluoride or its compounds escape into the atmosphere they attack the respiratory passages and set up inflammation of the eyes; further, workers handling the watery solutions are prone to skin affections (ulceration). The following are examples of the effects produced.[18] A worker in an art establishment upset a bottle of hydrofluoric acid and wetted the inner side of a finger of the right hand. Although he immediately washed his hands, a painful inflammation with formation of blisters similar to a burn of the second degree came on within a few hours. The blister became infected and suppurated. A man and his wife wished to obliterate the printing on the top of porcelain beer bottle stoppers with hydrofluoric acid. The man took a cloth, moistened a corner of it, and then rubbed the writing off. After a short time he noticed a slight burning sensation and stopped. His wife, who wore an old kid glove in doing the work, suffered from the same symptoms, the pain from which in the night became unbearable, and in spite of medical treatment gangrene of the finger-tips ensued. Healing took place with suppuration and loss of the finger-nails. Injury of the respiratory passages by hydrofluoric acid has often been reported. In one factory for its manufacture the hydrofluoric acid vapour was so great that all the windows to a height of 8 metres were etched dull. Several cases of poisoning by hydrofluoric acid were noted by me when examining the certificates of the Sick Insurance Society of Bohemia. In 1906 there were four due to inhalation of vapour of hydrofluoric acid in a hydrofluoric acid factory, with symptoms of corrosive action on the mucous membrane of the respiratory tract. In 1907 there was a severe case in the etching of glass.[19] NITRIC ACID. MANUFACTURE AND USES.—_Nitric acid_ (HNO₃) is obtained by distillation when Chili saltpetre (sodium nitrate) is decomposed by sulphuric acid in cast-iron retorts according to the equation: NaNO₃ + H₂SO₄ = NaHSO₄ + HNO₃. Condensation takes place in fireclay Woulff bottles connected to a coke tower in the same way as has been described in the manufacture of hydrochloric acid. [Illustration: FIG. 9.—Preparation of Nitric Acid (_after Ost_)] Lunge-Rohrmann plate towers are also used instead of the coke tower. Earthenware fans—as is the case with acid gases generally—serve to aspirate the nitrous fumes. To free the nitric acid of the accompanying lower oxides of nitrogen (as well as chlorine, compounds of chlorine and other impurities) air is blown into the hot acid. The mixture of sodium sulphate and sodium bisulphate remaining in the retorts is either converted into sulphate by addition of salt or used in the manufacture of glass. The nitric acid obtained is used either as such or mixed with sulphuric acid or with hydrochloric acid. Pure nitric acid cannot at ordinary atmospheric pressure be distilled unaltered, becomes coloured on distillation, and turns red when exposed to light. It is extremely dangerous to handle, as it sets light to straw, for example, if long in contact with it. It must be packed, therefore, in kieselguhr earth, and when in glass carboys forwarded only in trains for transport of inflammable material. Red, _fuming nitric acid_, a crude nitric acid, contains much nitrous and nitric oxides. It is produced if in the distillation process less sulphuric acid and a higher temperature are employed or (by reduction) if starch meal is added. The successful production of nitric acid from the air must be referred to. It is effected by electric discharges in special furnaces from which the air charged with nitrous gas is led into towers where the nitric oxide is further oxidised (to tetroxide), and finally, by contact with water, converted into nitric acid. Nitric acid is used in the manufacture of phosphoric acid, arsenious acid, and sulphuric acid, nitro-glycerin and nitrocellulose, smokeless powder, &c. (see the section on Explosives), in the preparation of nitrobenzenes, picric acid, and other nitro-compounds (see Tar Products, &c.). The diluted acid serves for the solution and etching of metals, also for the preparation of nitrates, such as the nitrates of mercury, silver, &c. EFFECTS ON HEALTH.—Leymann considers that the average number of cases and duration of sickness among persons employed in the nitric acid industry are generally on the increase; the increase relates almost entirely to burns which can hardly be avoided with so strongly corrosive an acid. The number of burns amounts almost to 12 per cent. according to Leymann’s figures (i.e. on an average 12 burns per 100 workers), while among the packers, day labourers, &c., in the same industry the proportion is only 1 per cent. Affections of the respiratory tract are fairly frequent (11·8 per cent. as compared with 8·8 per cent. of other workers), which is no doubt to be ascribed to the corrosive action of nitrous fumes on the mucous membranes. Escape of acid fumes can occur in the manufacture of nitric acid though leaky retorts, pipes, &c., and injurious acid fumes may be developed in the workrooms from the bisulphate when withdrawn from the retorts, which is especially the case when excess of sulphuric acid is used. The poisonous nature of these fumes is very great, as is shown by cases in which severe poisoning has been reported from merely carrying a vessel containing fuming nitric acid.[1] Frequent accidents occur through the corrosive action of the acid or from breathing the acid fumes—apart from the dangers mentioned in the manufacture—in filling, packing, and despatching the acid—especially if appropriate vessels are not used and they break. Of such accidents several are reported. Further, reports of severe poisoning from the use of nitric acid are numerous. Inhalation of nitrous fumes (nitrous and nitric oxides, &c.) does not immediately cause severe symptoms or death; severe symptoms tend to come on some hours later, as the examples cited below show. Occurrence of such poisoning has already been referred to when describing the sulphuric acid industry. In the superphosphate industry also poisoning has occurred by accidental development of nitric oxide fumes on sodium nitrate mixing with very acid superphosphate. Not unfrequently poisoning arises in pickling metals (belt making, pickling brass; cf. the chapter on Treatment of Metals). Poisoning by nitrous fumes has frequently been reported from the action of nitric acid on organic substances whereby the lower oxides of nitrogen—nitrous and nitric oxides—are given off. Such action of nitric acid or of a mixture of nitric and sulphuric acid on organic substances is used for nitrating purposes (see Nitroglycerin; Explosives; Nitrobenzol). Through want of care, therefore, poisoning can arise in these industries. Again, this danger is present on accidental contact of escaping acid with organic substances (wood, paper, leather, &c.), as shown especially by fires thus created.[2] Thus, in a cellar were five large iron vessels containing a mixture of sulphuric and nitric acids. One of the vessels was found one morning to be leaking. The manager directed that smoke helmets should be fetched, intending to pump out the acid, and two plumbers went into the cellar to fix the pump, staying there about twenty-five minutes. They used cotton waste and handkerchiefs as respirators, but did not put on the smoke helmets. One plumber suffered only from cough, but the other died the same evening with symptoms of great dyspnœa. At the autopsy severe inflammation and swelling of the mucous membrane of the palate, pharynx and air passages, and congestion of the lungs were found. Two further fatal cases in the nitrating room are described by Holtzmann. One of the two complained only a few hours after entering the room of pains in the chest and giddiness. He died two days later. The other died the day after entering the factory, where he had only worked for three hours. In both cases intense swelling and inflammation of the mucous membrane was found. Holtzmann mentions cases of poisoning by nitrous fumes in the heating of an artificial manure consisting of a mixture of saltpetre, brown coal containing sulphur, and wool waste. Fatalities have been reported in workers who had tried to mop up the spilt nitric acid with shavings.[3] We quote the following other instances[4]: (1) Fatal poisoning of a fireman who had rescued several persons from a room filled with nitrous fumes the result of a fire occasioned by the upsetting of a carboy. The rescued suffered from bronchial catarrh, the rescuer dying from inflammation and congestion of the lungs twenty-nine hours after the inhalation of the gas. (2) At a fire in a chemical factory three officers and fifty-seven firemen became affected from inhalation of nitrous fumes, of whom one died. (3) In Elberfeld on an open piece of ground fifty carboys were stored. One burst and started a fire. As a strong wind was blowing the firemen were little affected by the volumes of reddish fumes. Soon afterwards at the same spot some fifty to sixty carboys were destroyed. Fifteen men successfully extinguished the fire in a relatively still atmosphere in less than half an hour. At first hardly any symptoms of discomfort were felt. Three hours later all were seized with violent suffocative attacks, which in one case proved fatal and in the rest entailed nine to ten days’ illness from affection of the respiratory organs. The Report of the Union for Chemical Industry for 1908 describes a similar accident in a nitro-cellulose factory. Of those engaged in extinguishing the fire twenty-two were affected, and in spite of medical treatment and use of the oxygen apparatus three died. From the same source we quote the following examples: In a denitrating installation (see Nitro-glycerin; Explosives) a man was engaged in blowing, by means of compressed air, weak nitric acid from a stoneware vessel sunk in the ground into a washing tower. As the whole system was already under high pressure the vessel suddenly exploded, and in doing so smashed a wooden vat containing similar acid, which spilt on the ground with sudden development of tetroxide vapours. The man inhaled much gas, but except for pains in the chest felt no serious symptoms at the time and continued to work the following day. Death occurred the next evening from severe dyspnœa. A somewhat similar case occurred in the nitrating room of a dynamite factory in connection with the cleaning of a waste acid egg; the vessel had for several days been repeatedly washed out with water made alkaline with unslaked lime. Two men then in turn got into the egg in order to remove the lime and lead deposit, compressed air being continuously blown in through the manhole. The foreman remained about a quarter of an hour and finished the cleaning without feeling unwell. Difficulty of breathing came on in the evening, and death ensued on the following day. In another case a worker was engaged in washing nitroxylene when, through a leak, a portion of the contents collected in a pit below. He then climbed into the pit and scooped the nitroxylene which had escaped into jars. This work took about three-quarters of an hour, and afterwards he complained of difficulty of breathing and died thirty-six hours later.[5] A worker again had to control a valve regulating the flow to two large vessels serving to heat or cool the nitrated liquid. Both vessels were provided with pressure gauges and open at the top. Through carelessness one of the vessels ran over, and instead of leaving the room after closing the valve, the man tried to get rid of the traces of his error, remaining in the atmosphere charged with the fumes,[6] and was poisoned. Nitric and Nitrous Salts and Compounds When dissolving in nitric acid the substances necessary for making the various nitrates, nitric and nitrous oxides escape. In certain cases nitric and hydrochloric acids are used together to dissolve metals such as platinum and gold and ferric oxides, when chlorine as well as nitrous oxide escapes. Mention is necessary of the following: _Barium nitrate_ (Ba(NO₃)₂) is prepared as a colourless crystalline substance by acting on barium carbonate or barium sulphide with nitric acid. Use is made of it in fireworks (green fire) and explosives. In analogous way strontium nitrate (Sr(NO₃)₂) is made and used for red fire. _Ammonium nitrate_ (NH₄NO₃), a colourless crystalline substance, is obtained by neutralising nitric acid with ammonia or ammonium carbonate, and is also made by dissolving iron or tin in nitric acid. It is used in the manufacture of explosives. _Lead nitrate_ (Pb(NO₃)₂), a colourless crystalline substance, is made by dissolving lead oxide or carbonate in nitric acid. It is used in dyeing and calico printing, in the preparation of chrome yellow and other lead compounds, and mixed with lead peroxide (obtained by treatment of red lead with nitric acid) in the manufacture of lucifer matches. Apart from risk from nitrous fumes (common to all these salts) there is risk also of chronic lead poisoning. _Nitrate of iron_ (Fe(NO₃)₂), forming green crystals, is made by dissolving sulphide of iron or iron in cold dilute nitric acid. The so-called nitrate of iron commonly used in dyeing consists of basic sulphate of iron (used largely in the black dyeing of silk). _Copper nitrate_ (Cu(NO₃)₂), prepared in a similar way, is also used in dyeing. _Mercurous nitrate_ (Hg₂(NO₃)₂) is of great importance industrially, and is produced by the action of cold dilute nitric acid on an excess of mercury. It is used for ‘carotting’ rabbit skins in felt hat making, for colouring horn, for etching, and for forming an amalgam with metals, in making a black bronze on brass (art metal), in painting on porcelain, &c. _Mercuric nitrate_ (Hg(NO₃)₂) is made by dissolving mercury in nitric acid or by treating mercury with excess of warm nitric acid. Both the mercurous and mercuric salts act as corrosives and are strongly poisonous (see also Mercury and Hat Manufacture). _Nitrate of silver_ (AgNO₃) is obtained by dissolving silver in nitric acid and is used commercially as a caustic in the well-known crystalline pencils (lunar caustic). Its absorption into the system leads to accumulation of silver in the skin—the so-called argyria (see Silver). Such cases of chronic poisoning are recorded by Lewin.[7] Argyria occurs among photographers and especially in the silvering of glass pearls owing to introduction of a silver nitrate solution into the string of pearls by suction. In northern Bohemia, where the glass pearl industry is carried on in the homes of the workers, I saw a typical case. The cases are now rare, as air pumps are used instead of the mouth. _Sodium nitrite_ (NaNO₂) is obtained by melting Chili saltpetre with metallic lead in cast-iron vessels. The mass is lixiviated and the crystals obtained on evaporation. The lead oxide produced is specially suitable for making red lead. Cases of lead poisoning are frequent and sometimes severe. Roth[8] mentions a factory where among 100 employed there were 211 attacks in a year. _Amyl nitrite_ (C₅H₁₁NO₂) is made by leading nitrous fumes into iso-amyl alcohol and distilling amyl alcohol with potassium nitrite and sulphuric acid. It is a yellowish fluid, the fumes of which when inhaled produce throbbing of the bloodvessels in the head and rapid pulse. For other nitric acid compounds see the following section on Explosives and the section on Manufacture of Tar Products (Nitro-benzene, &c.). Explosives Numerous explosives are made with aid of nitric acid or a mixture of nitric and sulphuric acids. Injury to health and poisoning—especially through development of nitrous fumes—can be caused. Further, some explosives are themselves industrial poisons, especially those giving off volatile fumes or dust. The most important are: _Fulminate of mercury_ (HgC₂N₂O₂) is probably to be regarded as the mercury salt of fulminic acid, an isomer of cyanic acid. It is used to make caps for detonating gunpowder and explosives, and is made by dissolving mercury in nitric acid and adding alcohol. The heavy white crystals of mercury fulminate are filtered off and dried. Very injurious fumes are produced in the reaction, containing ethyl acetate, acetic acid, ethyl nitrate, nitrous acid, volatile hydrocyanic acid compounds, hydrocyanic acid, ethyl cyanide, cyanic acid; death consequently can immediately ensue on inhalation of large quantities. The fulminate is itself poisonous, and risk is present in filtering, pressing, drying, and granulating it. Further, in filling the caps in the huts numerous cases of poisoning occur. Heinzerling thinks here that mercury fumes are developed by tiny explosions in the pressing and filling. In a factory in Nuremburg 40 per cent. of the women employed are said to have suffered from mercurial poisoning. Several cases in a factory at Marseilles are recorded by Neisser.[9] In addition to the risk from the salt there is even more from nitrous fumes, which are produced in large quantity in the fulminate department. _Nitro-glycerin_ (C₃H₅(O—NO₂)₃, dynamite, explosive gelatine).—Nitro-glycerin is made by action of a mixture of nitric and sulphuric acids on anhydrous glycerin. The method of manufacture is as follows (see fig. 10): glycerin is allowed to flow into the acid mixture in leaden vessels; it is agitated by compressed air and care taken that the temperature remains at about 22° C., as above 25° there may be risk. The liquid is then run off and separates into two layers, the lighter nitro-glycerin floating on the top of the acid. The process is watched through glass windows. The nitro-glycerin thus separated is run off, washed by agitation with compressed air, then neutralised (with soda solution) and again washed and lastly filtered. The acid mixture which was run off is carefully separated by standing, as any explosive oil contained in it will rise up. The waste acid freed from nitro-glycerin is recovered in special apparatus, being denitrified by hot air and steam blown through it. The nitrous fumes are condensed to nitric acid. The sulphuric acid is evaporated. _Dynamite_ is made by mixing nitro-glycerin with infusorial earth previously heated to redness and purified. _Blasting gelatine_ is made by dissolving gun cotton (collodion wool, nitro-cellulose) in nitro-glycerin. Both are pressed into cartridge shape. Nitro-glycerin itself is a strong poison which can be absorbed both through the skin and from the alimentary canal. Kobert describes a case where the rubbing of a single drop into the skin caused symptoms lasting for ten hours. Workmen engaged in washing out nitro-glycerin from the kieselguhr earth, having in doing so their bare arms immersed in the liquid, suffered. Although it be granted that nitro-glycerin workers become to a large extent acclimatised, cases of poisoning constantly occur in explosives factories referable to the effect of nitro-glycerin. Persons mixing and sieving dynamite suffer from ulcers under the nails and at the finger-tips which are difficult to heal. Further, where the apparatus employed is not completely enclosed nitrous fumes escape and become a source of danger. Formerly this danger was constantly present in the nitrating house where nitration was effected in open vessels. Now that this is usually done in closed nitrating apparatus with glass covers the danger is mainly limited to the acid separating house, wash house, and especially the room in which denitration of the waste acids is effected. [Illustration: FIG. 10.—Preparation of Nitro-glycerin. Nitrating Vessel (_after Guttmann_) A Glycerine reservoir; C Fume flue; D Acid supply pipe; E, G Compressed air supply; H, J Cooling coil.] A fatal case in a nitro-glycerin factory was reported in 1902 where, through carelessness, a separator had overflowed. The workman who tried to wash away the acid with water inhaled so much of the nitrous fumes that he succumbed sixteen hours later. Other cases of poisoning by nitrous fumes occurring in the denitrating department are described in detail in the section on the use of nitric acid. One of these occurred to a man forcing dilute nitric acid from an earthenware egg by means of compressed air into a washing tower. The egg burst and broke an acid tank. The workman died on the following day. A fatal case occurred in a dynamite factory in cleaning out a storage tank for waste acid in spite of previous swilling and ventilation. _Gun cotton_ (_pyroxyline_) and its use.—Pyroxyline is the collective name for all products of the action of nitric acid on cellulose (cotton wool and similar material); these products form nitric acid ester of cellulose (nitro-cellulose). Gun cotton is formed by the action of strong nitric acid on cellulose (cotton wool). A mixture of sulphuric and nitric acids is allowed to act on cotton wool (previously freed from grease, purified, and dried), with subsequent pressing and centrifugalising. In the nitrating centrifugal machine (in the Selvig-Lange method) both processes are effected at the same time. The interior of this apparatus is filled with nitric acid, cotton wool is introduced, the acid fumes exhausted through earthenware pipes, and the remainder of the acid removed by the centrifugal machine; the nitrated material is then washed, teazed in teazing machines, again washed, neutralised with calcium carbonate, again centrifugalised, and dried. Since drying in drying stoves is a great source of danger of explosion, dehydration is effected with alcohol, and the gun cotton intended for the production of smokeless powder carried directly to the gelatinising vessels (see Smokeless Powder). Gun cotton, apart from its use for smokeless powder, is pressed in prisms and used for charging torpedoes and sea mines. _Collodion cotton_ is a partially nitrated cellulose. It is prepared generally in the same way as gun cotton, except that it is treated with a more dilute acid. It is soluble (in contradistinction to gun cotton) in alcohol-ether, and the solution is known as collodion (as used in surgery, photography, and to impregnate incandescent gas mantles). Mixed with camphor and heated collodion forms celluloid. In Chardonnet’s method for making artificial silk collodion is used by forcing it through fine glass tubes and drawing and spinning it. The alcohol-ether vapours are carried away by fans and the spun material is de-nitrated by ammonium sulphide. _Smokeless powder_ is a gun cotton powder—that is gun cotton the explosive power of which is utilised by bringing it into a gelatinous condition. This is effected by gelatinising the gun cotton with alcohol-ether or acetone (sometimes with addition of camphor, resin, &c.). A doughy, pasty mass results, which is then rolled, washed, dried, and pressed into rods. Nobel’s nitroleum (artillery powder) consists half of nitro-glycerin and half of collodion cotton. In the production of gun cotton and collodion cotton the workers are affected and endangered by nitric and nitrous fumes unless the nitrating apparatus is completely airtight. Erosion of the incisor teeth is general, but use of the new nitrating apparatus, especially of the nitrating centrifugal machines already described, has greatly diminished the evil. In making collodion, celluloid and artificial silk, in addition to the risks referred to in the production of gun cotton, the vapour from the solvents, ether, alcohol, acetone, acetic-ether, and camphor, comes into consideration, but there is no account of such poisoning in the literature of the subject. Other explosives which belong to the aromatic series are described in the chapter on Tar Derivatives, especially picric acid. PHOSPHORUS AND PHOSPHORUS MATCHES The total production of _phosphorus_ is not large. Formerly it was prepared from bone ash. Now it is made from phosphorite, which, as in the super-phosphate industry, is decomposed by means of sulphuric acid, soluble phosphate and calcium sulphate being formed; the latter is removed, the solution evaporated, mixed with coal or coke powder, distilled in clay retorts, and received in water. Phosphorus is also obtained electro-chemically from a mixture of tricalcium phosphate, carbon, and silicic acid, re-distilled for further purification, and finally poured under water into stick form. _Red phosphorus_ (amorphous phosphorus) is obtained by heating yellow phosphorus in the absence of air and subsequently extracting with carbon bisulphide. _Phosphorus matches_ are made by first fixing the wooden splints in frames and then dipping the ends either into paraffin or sulphur which serve to carry the flame to the wood. Then follows dipping in the phosphorus paste proper, for which suitable dipping machines are now used. The phosphorus paste consists of yellow phosphorus, an oxidising agent (red lead, lead nitrate, nitre, or manganese dioxide) and a binding substance (dextrine, gum); finally the matches are dried and packed. _Safety matches_ are made in the same way, except that there is no phosphorus. The paste consists of potassium chlorate, sulphur, or antimony sulphide, potassium bichromate, solution of gum or dextrine, and different admixtures such as glass powder, &c. These matches are saturated with paraffin or ammonium phosphate. To strike them a special friction surface is required containing red phosphorus, antimony sulphide, and dextrine. In the act of striking the heat generated converts a trace of the red phosphorus into the yellow variety which takes fire. Danger to health arises from the poisonous gases evolved in the decomposition of the calcined bones by sulphuric acid. When phosphorus is made from phosphorite the same dangers to health are present as in the production of super-phosphate artificial manure, which is characterised by the generation of hydrofluoric and fluosilicic acids. In the distillation of phosphorus phosphoretted hydrogen and phosphorus fumes may escape and prove dangerous. Industrial poisoning from the use of white phosphorus in the manufacture of matches has greater interest than its occurrence in the production of phosphorus itself. Already in 1845 chronic phosphorus poisoning (phosphorus necrosis) had been observed by Lorinser, and carefully described by Bibra and Geist in 1847. In the early years of its use phosphorus necrosis must have been fairly frequent in lucifer match factories, and not infrequently have led to death. This necessitated preventive measures in various States (see Part III); cases became fewer, but did not disappear altogether. Especially dangerous is the preparation of the paste, dipping, and manipulations connected with drying and filling the matches into boxes. According to the reports of the Austrian factory inspectors there are about 4500 lucifer match workers in that country, among whom seventy-four cases of necrosis are known to have occurred between the years 1900 and 1908 inclusive. Teleky[1] considers these figures much too small, and from inquiries undertaken himself ascertained that 156 cases occurred in Austria between 1896 and 1906, while factory inspectors’ reports dealt with only seventy-five. He was of opinion that his own figures were not complete, and thinks that in the ten years 1896 to 1905 there must have been from 350 to 400 cases of phosphorus necrosis in the whole of Austria. Despite strict regulations, modern equipment of the factories, introduction of improved machinery, and limitation of the white phosphorus match industry to large factories, it has not been possible to banish the risk, and the same is true of Bohemia, where there is always a succession of cases. Valuable statistics of phosphorus necrosis in Hungary are available.[2] In 1908 there were sixteen factories employing 1882 workers of whom 30 per cent. were young—children even were employed. The industry is carried on in primitive fashion without hygienic arrangements anywhere. It is strange that, notwithstanding these bad conditions, among a large number of the workers examined only fourteen active cases were found, in addition to two commencing, and fifteen cured—altogether thirty-one cases (excluding fifty-five cases in which there was some other pathological change in the mouth). Altogether ninety-three cases since 1900 were traced in Hungary, and in view of the unsatisfactory situation preventive measures, short of prohibition of the use of white phosphorus, would be useless. In England among 4000 lucifer match workers there were thirteen cases in the years 1900 to 1907 inclusive. Diminution in the number was due to improved methods of manufacture and periodical dental examination prescribed under Special Rules. Phosphorus necrosis is not the only sign of industrial phosphorus poisoning, as the condition of fragilitas ossium is recognised.[3] From what has been said it is evident that preventive measures against phosphorus poisoning, although they diminish the number, are not able to get rid of phosphorus necrosis, and so civilised States have gradually been driven to prohibit the use of white phosphorus (for the history of this see Part III). Use of chrome salts (especially potassium bichromate) in the preparation of the paste causes risk of poisoning in premises where ‘Swedish’ matches are made. Attention has been called to the frequency of chrome ulceration.[4] The paste used consists of 3-6 per cent. chrome salt, so that each match head contains about ½ mg. Wodtke found among eighty-four workers early perforation of the septum in thirteen. Severe eczema also has been noted. It is even alleged that red phosphorus is not entirely free from danger. Such cachexia as has been noted may be referable to the absorption of potassium chlorate. Other Uses of Phosphorus and Compounds of Phosphorus Isolated cases of phosphorus poisoning have been observed in the manufacture of phosphor-bronze. This consists of 90 parts copper, 9 parts tin, and 0·5 to 0·75 phosphorus. _Sulphides of phosphorus_ (P₂S₅, P₄S₃, P₂S₃) are made by melting together red phosphorus and sulphur. They make a satisfactory substitute for the poisonous yellow phosphorus and are considered non-poisonous, but the fact remains that they give off annoying sulphuretted hydrogen gas. _Phosphoretted hydrogen gas_ (PH₃) rarely gives rise to industrial poisoning. It may come off in small amounts in the preparation of acetylene and in the preparation of, and manipulations with, white phosphorus. It is stated that in acetylene made of American calcium carbide 0·04 per cent. of phosphoretted hydrogen is present, and in acetylene from Swedish calcium carbide 0·02 per cent.; Lunge and Cederkreutz found an acetylene containing 0·06 per cent. These amounts might cause poisoning if the gas were diffused in confined spaces. Poisoning, in part attributable to phosphoretted hydrogen gas, is brought about through ferro-silicon (see under Ferro-silicon). Superphosphate and Artificial Manure _Superphosphate_, an artificial manure, is prepared from various raw materials having a high proportion of insoluble basic calcium phosphate (tricalcium phosphate), which by treatment with sulphuric acid are converted into the soluble acid calcium phosphate (monocalcium phosphate) and calcium sulphate. Mineral substances such as phosphorites, coprolites, guano, bone ash, &c., serve as the starting-point. Chamber acid, or sometimes the waste acid from the preparation of nitro-benzene or purification of petroleum, are used in the conversion. The raw materials are ground in closed-in apparatus, under negative pressure, and mixed with the sulphuric acid in wooden lead-lined boxes or walled receptacles. The product is then stored until the completion of the reaction in ‘dens,’ dried, and pulverised in disintegrators. In the manufacture of bone meal extraction of the fat from the bones with benzine precedes treatment with acid. A further source of artificial manure is _basic slag_—the slag left in the manufacture of steel by the Gilchrist-Thomas method—which contains 10-25 per cent. of readily soluble phosphoric acid. It requires, therefore, only to be ground into a very fine powder to serve as a suitable manure. Owing to the considerable heat generated by the action of the sulphuric acid when mixed with the pulverised raw materials (especially in the conversion of the phosphorites) hydrofluoric and silicofluoric acid vapours are evolved in appreciable amount, and also carbonic and hydrochloric acid vapours, sulphur dioxide, and sulphuretted hydrogen gas. These gases—notably such as contain fluorine—if not effectually dealt with by air-tight apparatus and exhaust ventilation—may lead to serious annoyance and injury to the persons employed. Further, there is risk of erosion of the skin from contact with the acid, &c. A case is described of pustular eczema on the scrotum of a worker engaged in drying sodium silicofluoride, due probably to conveyance of irritating matter by the hands. After the precaution of wearing gloves was adopted the affection disappeared. A marked case of poisoning by nitrous fumes even is recorded in the manufacture of artificial manure from mixing Chili saltpetre with a very acid superphosphate. Injurious fumes can be given off in the rooms where bones are stored and, in the absence of efficient ventilation, carbonic acid gas can accumulate to an amount that may be dangerous. The fine dust produced in the grinding of _basic slag_ has, if inhaled, a markedly corrosive action on the respiratory mucous membrane attributed by some to the high proportion (about 50 per cent.) in it of quicklime. As a matter of fact numerous small ulcers are found on the mucous membranes of basic slag grinders and ulceration of the lung tissue has been observed. The opinion is expressed that this is due to corrosive action of the dust itself, and not merely to the sharp, jagged edged particles of dust inhaled. And in support of this view is cited the frequency with which epidemics of pneumonia have been noted among persons employed in basic slag works. Thus in Nantes thirteen cases of severe pneumonia followed one another in quick succession. And similar association has been noted in Middlesbrough, where the action of the basic slag dust was believed to injure the lung tissue and therefore to provide a favourable soil for the development of the pneumonia bacillus. Statistics collected by the Imperial Health Office showed that in the three years 1892, 1893, and 1894, 91·1 per cent., 108·9 per cent., and 91·3 per cent. respectively of the workers became ill, the proportion of respiratory diseases being 56·4 per cent., 54·4 per cent., and 54·3 per cent. respectively. A case of severe inflammation of the lungs is described in a labourer scattering basic slag in a high wind which drove some of it back in his face. Lewin has described a case in which a worker scattering a mixture of basic slag and ammonium superphosphate suffered from an eczematous ulceration which, on being scratched by the patient, became infected and led to death from general blood poisoning. Lewin regarded the fatal issue as the sequela of the scattering of the manure. Inflammation of the conjunctiva and of the eyelids has been recorded. CHROMIUM COMPOUNDS AND THEIR USES Chrome ironstone, lime, and soda are ground and intimately mixed. They are next roasted in reverberatory furnaces, neutral _sodium chromate_ being formed. This is lixiviated and converted into sodium bichromate (Na₂Cr₂O₇) by treatment with sulphuric acid. Concentration by evaporation follows; the concentrated liquor is crystallised in cast-iron tanks. The crystals are centrifugalised, dried, and packed. _Potassium bichromate_ may be made in the same way, or, as is usually the case, out of sodium bichromate and potassium chloride. The bichromates are used in the preparation and oxidation of chrome colours, but their principal use is in dyeing and calico printing, bleaching palm oil, purifying wood spirit and brandy, in the preparation of ‘Swedish’ matches, in the manufacture of glass, in photography, in dyeing, in tanning, and in oxidation of anthracene to anthraquinone. Lead Chromate and Chrome Colours _Chrome yellow_ is neutral lead chromate (PbCrO₄). It is obtained by precipitating a solution of potassium bichromate with lead acetate or lead nitrate, or by digesting the bichromate solution with lead sulphate, and is used as a paint and in calico and cloth printing. With Paris or Berlin blue it forms a _chrome green_. _Chrome orange_, i.e. basic lead chromate (PbCrO₄Pb(OH)₂) is made by adding milk of lime to lead chromate and boiling. _Chromium_ and _chromic acid salts_ are widely used in dyeing and printing, both as mordants and oxidising agents and as dyes (chrome yellow, chrome orange). In mordanting wool with potassium chromate the wool is boiled in a potassium chromate solution to which acids such as sulphuric, lactic, oxalic, or acetic are added. In dyeing with chrome yellow, for instance, the following is the process. Cotton wool is saturated with nitrate or acetate of lead and dried, passed through lime water, ammonia, or sodium sulphate, and soaked in a warm solution of potassium bichromate. The yellow is converted into the orange colour by subsequent passage through milk of lime. _Chrome tanning._—This method of producing chrome leather, first patented in America, is carried out by either the single or two bath process. In the two bath process the material is first soaked in a saturated solution of bichromate and then treated with an acid solution of thiosulphate (sodium hyposulphite) so as to reduce completely the chromic acid. The process is completed even with the hardest skins in from two to three days. In the single bath method basic chrome salts are used in highly concentrated form. The skins are passed from dilute into strong solutions. In this process also tanning is quickly effected. EFFECTS ON HEALTH.—Among the persons employed in the bichromate factory of which Leymann has furnished detailed particulars, the number of sick days was greater than that among other workers. Further, _erosion of the skin_ (_chrome holes_) is characteristic of the manufacture of bichromates. These are sluggish ulcers taking a long time to heal. This is the main cause of the increased general morbidity that has been observed. The well-known perforation of the septum of the nose without, however, causing ulterior effects, was observed by Leymann in all the workers in the factory. This coincides with the opinion of others who have found the occurrence of chrome holes, and especially perforation of the septum, as an extraordinarily frequent occurrence. Many such observations are recorded,[1] and also in workers manufacturing ‘Swedish’ matches. Thus of 237 bichromate workers, ulcers were present in 107 and perforation in 87. According to Lewin, who has paid special attention to the poisonous nature of chromium compounds, they can act in two ways: first, on the skin and mucous membrane, where the dust alights, on the alimentary tract by swallowing, and on the pharynx by inhalation. Secondly, by absorption into the blood, kidney disease may result. The opinion that chromium, in addition to local, can have constitutional effect is supported by other authorities. Leymann describes a case of severe industrial chrome poisoning accompanied by nephritis in a worker who had inhaled and swallowed much chromate dust in cleaning out a vessel. Regulations for the manufacture of bichromates (see Part III) have no doubt improved the condition, but reports still show that perforation of the septum generally takes place. It must be borne in mind that practically all chromium compounds are not alike poisonous. Chrome ironstone is non-poisonous, and the potassium and sodium salts are by far the most poisonous, while the neutral chromate salts and chromic oxide are only slightly so. Pander found that bichromates were 100 times as poisonous as the soluble chromium oxide compounds, and Kunkel is of opinion that poisonous effect shown by the oxides is attributable to traces of oxidation into chromic acid. Lewin, on the other hand, declares in a cautionary notice for chrome workers generally that all chromium compounds are poisonous, and therefore all the dyes made from them.[2] In the manufacture of bichromates, chance of injury to health arises partly from the dust, and partly from the steam, generated in pouring water over the molten mass. The steam carries particles of chromium compounds with it into the air. In evaporating the chromate solutions, preparation of the bichromate, breaking the crystals, drying and packing, the workers come into contact with the substance and the liquors. Chrome ulceration is, therefore, most frequently found among those employed in the crystal room and less among the furnace hands. From 3·30 to 6·30 mg. of bichromate dust have been found in 1 c.m. of air at breathing level in the room where chromate was crushed, and 1·57 mg. where it was packed. Further, presence of chromium in the steam escaping from the hot chrome liquors has been proved.[3] Poisoning from use of chrome colours is partly attributable to lead, as, for example, in making yellow coloured tape measures, yellow stamps, and from the use of coloured thread. Gazaneuve[4] found 10 per cent. of lead chromate in such thread, in wool 18 per cent., and in the dust of rooms where such yarn was worked up 44 per cent. Use of chrome colours and mordants is accompanied by illness which certainly is referable to the poisonous nature of the chrome. In France use of chromic and phosphoric acid in etching zinc plates has caused severe ulceration. Bichromate poisoning has been described among photographers in Edinburgh in the process of carbon printing, in which a bichromate developer is used.[5] There is much evidence as to occurrence of skin eruptions and development of pustular eczema of the hands and forearms of workers in chrome tanneries.[6] In a large leather factory where 300 workers were constantly employed in chrome tanning nineteen cases of chrome ulceration were noted within a year. Injury to health was noted in a chrome tannery in the district of Treves, where the two bath process was used, from steam developed in dissolving the chromate in hot water. Finally, I have found several records in 1907 and 1908 of perforation of the septum in Bohemian glass workers. MANGANESE COMPOUNDS The raw material of the manganese industry is _hausmannite_ (manganese dioxide, MnO₂). This is subjected to a crushing process, sorted, sieved, finely ground, washed, and dried. The pure finely ground manganese dioxide is much used in the chemical industry, especially in the recovery of chlorine in the Weldon process and in the production of _potassium permanganate_, which is obtained by melting manganese dioxide with caustic soda and potassium chlorate or nitre, lixiviation and introduction of carbonic acid, or better by treatment with ozone. Manganese is also used in the production of colours: the natural and artificial umbers contain it; in glass works it is used to decolourise glass, and also in the production of coloured glass and glazes; in the manufacture of stove tiles, and in the production of driers for the varnish and oil industry. Manganese and compounds of manganese are dangerous when absorbed into the system as dust. Already in 1837 nervous disorders had been described in workmen who ground manganese dioxide.[1] The malady was forgotten, until Jaksch[2] in Prague in 1901 demonstrated several such cases in persons employed in a large chemical factory in Bohemia, from the drying of Weldon mud. In the same year three similar cases were also described in Hamburg.[3] In 1902 Jaksch observed a fresh case of poisoning, and in the factory in question described a condition of manganophobia among the workers, obviously hysterical, in which symptoms of real manganese poisoning were simulated. In all some twenty cases are known. Jaksch is of opinion that it is manganese dust rich in manganese protoxide that is alone dangerous, since, if the mud has been previously treated with hydrochloric acid, by which the lower oxides are removed, no illness can be found. The most dangerous compounds are MnO and Mn₃O₄. PETROLEUM OCCURRENCE AND USES.—Crude petroleum flows spontaneously from wells in consequence of high internal pressure of gas or is pumped up. In America and Russia also it is conveyed hundreds of miles in conduits to the ports to be led into tank steamers. The crude oil is a dark-coloured liquid which, in the case of Pennsylvanian mineral oil, consists mainly of a mixture of hydrocarbons of the paraffin series, or, in Baku oil, of those of the naphtha series. There are in addition sulphur compounds, olefines, pyridin, &c. The crude oil is unsuitable for illuminating purposes and is subjected to a distillation process. It is split up into three fractions by a single distillation, namely, (_a_) benzines (boiling-point 150° C.), (_b_) lighting oil (boiling-point 150°-300° C.); at a temperature of 300° C. the distillation is stopped so that (_c_) the residuum boiling above 300° C. remains. Distillation is effected (in America) in large stills, in which periodically benzine and lighting oil up to 300° C. is distilled and the residuum run off. In Baku continuously working batteries of so-called cylindrical boilers are used, into which the crude oil streams. In the first set of boilers, the temperature in which rises to 150° C., the benzine is distilled off, and in the succeeding ones, heated to 300° C., the illuminating petroleum oils (kerosine), the residuum flowing continually away. The _mineral oil residues_ are used as fuel. Heating by this means, tried first only in Russia, is spreading, especially for the heating of boilers, in which case the liquid fuel is blown in generally as a spray. The combustion if rightly planned is economical and almost smokeless. The American oil residuum, rich in paraffin, is distilled, the distillate is cooled and separated by pressure into solid paraffin and liquid oil. The latter and the Russian mineral oil residues which are free from paraffin are widely used as lubricants. In the production of lubricants the residues are distilled at low temperature (in vacuo or by aid of superheated steam) and separated into various qualities by fractional cooling, are then purified with sulphuric acid, and finally washed with caustic soda solution. In the preparation of vaseline the residum is not distilled, but purified only with fuming sulphuric acid and decolourised with animal charcoal. The _illuminating oil_ is next subjected to a purifying process (refining); it is first treated with sulphuric acid and well agitated by means of compressed air. The acid laden with the impurities is drawn off below, and the oil freed from acid by washing first with caustic soda and subsequently with water. It is then bleached in the sun. For specially fine and high flash point petroleum the oil undergoes a further distillation and purification with acid. The fractions of crude petroleum with low boiling-point (under 150° C.) are known commercially as raw _benzine_ or _petrol naphtha_. It is used for cleaning, in extraction of fats and oils, and for benzine motors. Frequently raw benzine is subjected to a purifying process and to fractional distillation. Purification is carried out by means of sulphuric acid and soda liquor and subsequent separation into three fractions and a residue which remains in the retort—(_a_) _petroleum ether_ (called gasoline, canadol, and rhigoline), which comes over between 40° and 70° C., and serves for carburetting water gas and other similar gases, as a solvent for resin, oil, rubber, &c.; (_b_) _purified benzine_ (70°-120° C.) is used as motor spirit and in chemical cleaning; (_c_) _ligroine_ (120°-135° C.), used for illuminating purposes; and (_d_) the _residual oil_ (above 135° C.) serves for cleaning machinery and, especially, as a solvent for lubricating oil, and instead of turpentine in the production of lacquers, varnishes, and oil colours. In _chemical cleaning_ works benzine is used in closed-in washing apparatus, after which the clothes are centrifugalised and dried. In view of the risk of fire in these manipulations, originating mainly from frictional electricity, various substances are recommended to be added to the benzine, of which the best known is that recommended by Richter, consisting of a watery solution of oleate of sodium or magnesium. EFFECTS ON HEALTH.—Industrial poisoning in the petroleum industry is attributable to the gases given off from crude petroleum or its products and to inhalation of naphtha dust. Poisoning occurs principally in the recovery of petroleum and naphtha from the wells, in storage and transport (in badly ventilated tanks on board ship, and in entering petroleum tanks), in the refinery in cleaning out petroleum stills and mixing vessels, and in emptying out the residues. Further cases occur occasionally from use of benzine in chemical cleaning. In addition to poisoning the injurious effect of petroleum and its constituents on the skin must be borne in mind. Opinion is unanimous that this injurious action of mineral oil is limited to the petroleum fractions with high boiling-point and especially petroleum residues. Statistics officially collected in Prussia show the general health of petroleum workers to be favourable. These statistics related to 1380 persons, of whom forty-three were suffering from symptoms attributable to their occupation. Of these forty-three, nine only were cases of poisoning, the remainder being all cases of petroleum acne. The conditions also in French refineries from statistics collected in the years 1890-1903 seem satisfactory. Eighteen cases of petroleum acne were reported, eleven of which occurred at the paraffin presses, five in cleaning out the still residues, and two were persons filling vessels. The conditions are clearly less favourable in the Russian petroleum industry.[1] The workers at the naphtha wells suffer from acute and chronic affections of the respiratory organs. Those suffer most who cover the wells with cast iron plates to enable the flow of naphtha to be regulated and led into the reservoirs. In doing this they inhale naphtha spray. Lewin[2] describes cases of severe poisoning with fatal issue among American workers employed in petroleum tanks. One man who wished to examine an outlet pipe showed symptoms after only two minutes. Weinberger describes severe poisoning of two workers engaged in cleaning out a vessel containing petroleum residue. Interesting particulars are given of the effect of petroleum emanations on the health of the men employed in the petroleum mines of Carpathia, among whom respiratory affections were rarely found, but poisoning symptoms involving unconsciousness and cerebral symptoms frequently. These experiences undoubtedly point to differing physiological effects of different kinds of naphtha. This is supported by the view expressed by Sharp in America that different kinds of American petroleum have different effects on the health of the workers, which can be easily credited from the different chemical composition of crude naphthas. Thus in Western Virginia, where a natural heavy oil is obtained, asphyxia from the gas is unknown, although transient attacks of headache and giddiness may occur, whereas in Ohio, where light oils are obtained, suffocative attacks are not infrequent. And it is definitely stated that some naphtha products irritate the respiratory passages, while others affect the central nervous system.[3] The authors mentioned refer to occurrence of cases of poisoning in the refining of naphtha from inhalation of the vapour of the light oils benzine and gasoline. Fatal cases have been recorded in badly ventilated workrooms in which the products of distillation are collected. Workers constantly employed in these rooms develop chronic poisoning, which is reported also in the case of women employed with benzine. Intoxication is frequently observed, it is stated, among the workmen employed in cleaning out the railway tank waggons in which the mineral oils and petroleum are carried. Foulerton[4] describes severe poisoning in a workman who had climbed into a petroleum reservoir, and two similar cases from entering naphtha tanks are given in the Report of the Chief Inspector of Factories for 1908. Two fatal cases are reported by the Union of Chemical Industry in Germany in 1905 in connection with naphtha stills. Such accidents are hardly possible, except when, through insufficient disconnection of the still from the further system of pipes, irrespirable distillation gases pass backwards into the opened still where persons are working. Ordinary cocks and valves, therefore, do not afford sufficient security. Thus, several workers engaged in repairing a still were rendered unconscious by gases drawn in from a neighbouring still, and were only brought round after oxygen inhalation. Gowers describes a case of chronic poisoning following on frequent inhalation of gases given off from a petroleum motor, the symptoms being slurring speech, difficulty of swallowing, and weakness of the orbicularis and facial muscles. Gowers believed this to be petroleum gas poisoning (from incomplete combustion), especially as the symptoms disappeared on giving up the work, only to return on resuming it again.[5] Girls employed in glove cleaning and rubber factories are described as having been poisoned by benzine.[6] Poisoning of chauffeurs is described by several writers.[7] Recent literature[8] tends to show marked increase in the number of cases of poisoning from greater demand for benzine as a motive power for vehicles. Such cases have been observed in automobile factories, and are attributable to the hydrocarbons of low boiling-point which are present as impurities in benzine. A worker in a paraffin factory had entered an open benzine still to scrape the walls free of crusts containing benzine. He was found unconscious and died some hours later. It appeared that he had been in the still several hours, having probably been overcome to such an extent by the fumes as to be unable to effect his escape. Attempt to wipe up benzine spilt in the storage cellar of a large chemical cleaning works resulted in poisoning. A night worker in a bone extracting works having turned on the steam, instead of watching the process fell asleep on a bench. In consequence the apparatus became so hot that the solder of a stop valve melted, allowing fumes to escape. The man was found dead in the morning. In a carpet cleaning establishment three workers lost consciousness and were found senseless on the floor. They recovered on inhalation of oxygen. One further case reported from the instances of benzine poisoning collected recently[9] is worth quoting. A worker in a chemical factory was put to clean a still capable of distilling 2500 litres of benzine. It contained remains of a previous filling. As soon as he had entered the narrow opening he became affected and fell into the benzine; he was carried unconscious to the hospital, his symptoms being vomiting, spastic contraction of the extremities, cyanosis, weak pulse, and loss of reflexes, which disappeared an hour and a half later. The occurrence of skin affections in the naphtha industry has been noted by several observers, especially among those employed on the unpurified mineral oils. Eruptions on the skin from pressing out the paraffin and papillomata (warty growths) in workers cleaning out the stills are referred to by many writers,[10] Ogston in particular. Recent literature refers to the occurrence of petroleum eczema in a firebrick and cement factory. The workers affected had to remove the bricks from moulds on to which petroleum oil dropped. An eczematous condition was produced on the inner surface of the hands, necessitating abstention from work. The pustular eczema in those employed only a short time in pressing paraffin in the refineries of naphtha factories is referred to as a frequent occurrence. Practically all the workers in three refineries in the district of Czernowitz were affected. The view that it is due to insufficient care in washing is supported by the report of the factory inspector in Rouen, that with greater attention in this matter on the part of the workers marked diminution in its occurrence followed. SULPHUR RECOVERY AND USE.—Sulphur, which is found principally in Sicily (also in Spain, America, and Japan), is obtained by melting. In Sicily this is carried out in primitive fashion by piling the rock in heaps, covering them with turf, and setting fire to them. About a third of the sulphur burns and escapes as sulphur dioxide, while the remainder is melted and collects in a hole in the ground. The crude sulphur thus wastefully produced is purified by distillation in cast-iron retorts directly fired. It comes on the market as stick or roll sulphur or as flowers of sulphur. Further sources for recovery of sulphur are the Leblanc soda residues (see Soda Production), from which the sulphur is recovered by the Chance-Claus process, and the gas purifying material (containing up to 40 per cent.), from which the sulphur can be recovered by carbon bisulphide (see Illuminating Gas Industry). The health conditions of the Sicilian sulphur workers are very unsatisfactory, due, however, less to the injurious effect of the escaping gases (noxious alike to the surrounding vegetation) than to the wretched social conditions, over exertion, and under feeding of these workers. Of importance is the risk to health from sulphuretted hydrogen gas, from sulphur dioxide in the recovery of sulphur from the soda residues, and from carbon bisulphide in the extraction of sulphur from the gas purifying material. SULPHURETTED HYDROGEN GAS Sulphuretted hydrogen gas is used in the chemical industry especially for the precipitation of copper in the nickel and cobalt industry, in de-arsenicating acid (see Hydrochloric and Sulphuric Acids), to reduce chrome salts in the leather industry, &c. In addition it arises as a product of decomposition in various industries, such as the Leblanc soda process, in the preparation of chloride of antimony, in the decomposition of barium sulphide (by exposure to moist air), in the treatment of gas liquors, and in the preparation of carbon bisulphide: it is present in blast furnace gas, is generated in mines (especially in deep seams containing pyrites), arises in tar distillation, from use of gas lime in tanning, and in the preparation and use of sodium sulphide: large quantities of the gas are generated in the putrefactive processes connected with organic sulphur-containing matter such as glue making, bone stores, storage of green hides, in the decomposition of waste water in sugar manufacture and brewing, in the retting of flax, and especially in sewers and middens. Both _acute_ and _chronic_ poisoning are described. The following case is reported by the Union of Chemical Industry in 1907: Three plumbers who were employed on the night shift in a chemical factory and had gone to sleep in a workroom were found in a dying condition two hours later. In the factory barium sulphide solution in a series of large saturating vessels was being converted into barium carbonate by forcing in carbonic acid gas; the sulphuretted hydrogen gas evolved was collected in a gasometer, burnt, and utilised for manufacture of sulphuric acid. In the saturating vessels were test cocks, the smell from which enabled the workers to know whether all the sulphuretted hydrogen gas had been driven out. If this was so the contents of the retort were driven by means of carbonic acid gas into a subsidiary vessel, and the vessel again filled with barium sulphide liquor. From these intermediate vessels the baryta was pumped into filter presses, the last remains of sulphuretted hydrogen gas being carried away by a fan into a ventilating shaft. The subsidiary vessel and ventilating shaft were situated in front of the windows of the repairing shop. On the night in question a worker had thoughtlessly driven the contents out of one saturating vessel before the sulphuretted hydrogen gas had been completely removed, and the driving belt of the fan was broken. Consequently, the sulphuretted hydrogen gas escaping from the subsidiary vessel entered through the windows of the workshop and collected over the floor where the victims of the unusual combination of circumstances slept. In another chemical works two workers suffered from severe poisoning in the barium chloride department. The plant consisted of a closed vat which, in addition to the openings for admitting the barium sulphide liquor and sulphuric acid, had a duct with steam injector connected with the chimney for taking away the sulphuretted hydrogen gas. Owing to a breakdown the plant was at a standstill, as a result of which the ventilating duct became blocked by ice. When the plant was set in motion again the sulphuretted hydrogen gas escaped through the sulphuric acid opening. One of the workers affected remained for two days unconscious.[1] The report of the Union of Chemical Industry for 1905 cites a case where an agitating vessel, in which, by action of acid on caustic liquor, sulphuretted hydrogen gas was given off and drawn away by a fan, had to be stopped to repair one of the paddles. The flow of acid and liquor was stopped, and the cover half removed. The deposit which had been precipitated had to be got rid of next in order to liberate the agitator. The upper portion of the vessel was washed out with water, and since no further evolution of sulphuretted hydrogen was possible from any manufacturing process, the work of removing the deposit was proceeded with. After several bucketfuls had been emptied the man inside became unconscious and died. The casualty was no doubt due to small nests of free caustic and acid which the spading brought into contact and subsequent developement of sulphuretted hydrogen afresh. A case is reported of sulphuretted hydrogen poisoning in a man attending to the drains in a factory tanning leather by a quick process. Here, when sulphurous acid acts on sodium sulphide, sulphuretted hydrogen is given off. In cleaning out a trap close to the discharge outlet of a tannery two persons were rendered unconscious, and the presence of sulphuretted hydrogen was shown by the blackening of the white lead paint on a house opposite and by the odour.[2] In the preparation of ammonium salts Eulenberg[3] cites several cases where the workers fell as though struck down, although the processes were carried on in the open air. They quickly recovered when removed from the spot. Oliver cites the case where, in excavating soil for a dock, four men succumbed in six weeks; the water contained 12 vols. per cent. of sulphuretted hydrogen. Not unfrequently acute poisoning symptoms result to sewer men. Probably sulphuretted hydrogen gas is not wholly responsible for them, nor for the chronic symptoms complained of by such workers (inflammation of the conjunctiva, bronchial catarrh, pallor, depression). In the distillation processes connected with the paraffin industry fatalities have been reported. CARBON BISULPHIDE MANUFACTURE.—Carbon bisulphide is prepared by passing sulphur vapour over pure coal brought to a red heat in cast-iron retorts into which pieces of sulphur are introduced. The crude carbon bisulphide requires purification from sulphur, sulphuretted hydrogen, and volatile organic sulphur compounds by washing with lime water and subsequent distillation. Use is made of it principally in the extraction of fat and oil from bones and oleaginous seeds (cocoanut, olives, &c.), for vulcanising, and as a solvent of rubber. It is used also to extract sulphur from gas purifying material and for the preparation of various chemical substances (ammonium sulphocyanide, &c.), as well as for the destruction of pests (phylloxera and rats). Fat and oil are extracted from seeds, bones, &c., by carbon bisulphide, benzine, or ether, and, to avoid evaporation, the vessels are as airtight as possible and arranged, as a rule, for continuous working. _Vulcanisation_ is the rendering of rubber permanently elastic by its combination with sulphur. It is effected by means of chloride of sulphur, sulphide of barium, calcium, or antimony, and other sulphur-containing compounds, heat and pressure, or by a cold method consisting in the dipping of the formed objects in a mixture of carbon bisulphide and chloride of sulphur. The process of manufacture is briefly as follows: The raw material is first softened and washed by hot water and kneading in rolls. The washed and dried rubber is then mixed on callender rolls with various ingredients, such as zinc white, chalk, white lead, litharge, cinnabar, graphite, rubber substitutes (prepared by boiling vegetable oils, to which sulphur has been added, with chloride of sulphur). In vulcanising by aid of heat the necessary sulphur or sulphur compound is added. Vulcanisation with sulphur alone is only possible with aid of steam and mechanical pressure in various kinds of apparatus according to the nature of the article produced. In the cold vulcanisation process the previously shaped articles are dipped for a few seconds or minutes in the mixture of carbon bisulphide and chloride of sulphur and subsequently dried in warm air as quickly as possible. In view of the poisonous nature of carbon bisulphide, benzine is much used now. In the cold method use of chloride of sulphur in benzine can replace it altogether. Instead of benzine other solvents are available—chlorine substitution products of methane (dichlormethane, carbon tetrachloride). In other processes _rubber solvents_ are largely used, for instance, acetone, oil of turpentine, petroleum benzine, ether, and benzene. Rubber solutions are used for waterproofing cloth and other materials. Similar to the preparation and use of rubber is that of guttapercha. But vulcanisation is easier by the lead and zinc thiosulphate process than by the methods used in the case of rubber. EFFECTS ON HEALTH OF CS₂ AND OTHER DANGERS TO HEALTH IN THE RUBBER INDUSTRY.—In the manufacture of carbon bisulphide little or no danger is run either to health or from fire. In the rubber trade the poisonous nature of _benzine_ and _chloride of sulphur_ have to be borne in mind, and also the considerable risk of _lead poisoning_ in mixing. Cases of plumbism, especially in earlier years, are referred to.[1] _Benzine_ poisoning plays only a secondary part in the rubber industry. No severe cases are recorded, only slight cases following an inhalation of fumes. Cases of poisoning are recorded in a motor tyre factory in Upsala.[2] Nine women were affected, of whom four died. Whether these cases were due to benzene or petroleum benzine is not stated. It is remarkable that two such very different substances as benzene and benzine should be so easily confused. But that in the rubber industry cases of benzene poisoning do actually occur is proved by the following recent cases: Rubber dissolved in benzol was being laid on a spreading machine in the usual way. Of three men employed one was rendered unconscious and died.[3] In a rubber recovery process a worker was rendered unconscious after entering a benzol still, also two others who sought to rescue him. Only one was saved. Cases of aniline poisoning are reported where aniline is used for extracting rubber.[4] _Chloride of sulphur_, by reason of its properties and the readiness with which it decomposes (see Chloride of Sulphur), causes annoyance to rubber workers, but rarely poisoning. Much importance attaches to _chronic carbon bisulphide poisoning_ in the rubber industry. Many scientists have experimented as to its poisonous nature (see especially on this Part II, p. 194). Lehmann’s[5] experiments show that a proportion of 0·50-0·7 mg. of CS₂ per litre of air causes hardly any symptoms; 1·0-1·2 mg. slight effects which become more marked on continued exposure; 1·5 mg. produces severe symptoms. About 1·0 mg. per litre of air is the amount which may set up chronic effects. In vulcanising rooms this limit may easily be exceeded unless special preventive measures are adopted. Laudenheimer[6] has made several analyses of the proportion of CS₂ in workrooms. Thus 0·9-1·8 mg. per litre of air were found in a room where pouches were vulcanised; 0·5-2·4 mg. were aspirated one-half metre distant from the dipping vessels; and 0·18-0·27 mg. in the room for making ‘baby comforters.’ In analyses made some years ago proportions of 2·9-5·6 mg. were obtained. Although literature contains many references to CS₂ poisoning, too much importance ought not to be attached to them now in view of the arrangements in modern well-equipped vulcanising premises. Laudenheimer has collected particulars of 31 cases of brain, and 19 of nervous, diseases among 219 persons coming into contact with CS₂ between 1874 and 1908, all of whom had been medically attended. In the last ten years, however, the psychical symptoms were seven times less than in the preceding period. Between 1896 and 1898 the average proportion of brain disease in the vulcanising department was 1·95 per cent., and of nervous diseases 0·22 per cent., as compared with 0·92 per cent. and 0·03 per cent. in the textile. Moreover, he maintains that practically all workers who come at all into contact with CS₂ must be to some extent affected injuriously by it. Studies on the injurious nature of CS₂ date from the years 1851-60, when the French writers Pazen, Duchenne, Beaugrand, Piorry, &c., came across cases from the Parkes’ process (cold vulcanisation by means of CS₂ and SCl₂). Delpech[7] published in 1860 and 1863 details of twenty-four severe cases in rubber workers, some of which were fatal, and at the same time described the pitiable conditions under which the work was carried on. In Germany Hermann, Hirt and Lewin, and Eulenberg dealt with the subject, but their work is more theoretical in character; and in Laudenheimer’s work referred to the histories of several cases are given in detail. Mention should be made of the injury caused to the skin by the fluids used in extraction of fat and in vulcanising—especially by benzine and carbon bisulphide. Perrin considers the effect due partly to the withdrawal of heat and partly to the solvent action on the natural grease, producing an unpleasant feeling of dryness and contraction of the skin. ILLUMINATING GAS Illuminating gas is obtained by the dry distillation of coal. The products of distillation are subjected on the gasworks to several purifying processes, such as condensation in coolers, moist and dry purifying, from which valuable bye-products (such as tar, ammonia, cyanogen compounds) are obtained. The purified gas is stored in gas holders containing on an average 49 per cent. hydrogen, 34 per cent. methane, 8 per cent. carbonic oxide, 1 per cent. carbon dioxide, 4 per cent. nitrogen, and about 4 per cent. of the heavy hydrocarbons (ethylene, benzene vapour, acetylene, and their homologues) to which the illuminating properties are almost exclusively due. The most important stages in its preparation will be shortly described. _Distillation_ is effected in cylindrical, usually horizontal, fireclay retorts placed in a group or setting (fig. 11), which formerly were heated by coke but in modern works always by gas. Charging with coal and removal of the coke takes place about every four hours, often by means of mechanical contrivances. Iron pipes conduct the products of distillation to the _hydraulic main_. This is a long covered channel extending the entire length of the stack and receiving the gas and distillate from each retort. In it the greater part of the tar and of the ammoniacal water condense and collect under the water which is kept in the main to act as a seal to the ends of the dip pipes, to prevent the gas from passing back into the retort when the latter is opened. While the liquid flows from the hydraulic main into cisterns, the gas passes into _coolers_ or _condensers_, tall iron cylinders, in which, as the result of air and water cooling, further portions of the tar and ammoniacal liquor are condensed. To free it still more from particles of tar the gas passes through the _tar separator_. [Illustration: FIG. 11.—Manufacture of Illuminating Gas. Horizontal fireclay retorts placed in a setting and heated by gas(_after Ost_)] The tar which remains behind flows through a tube to the cistern. From the tar separator the gas goes through _scrubbers_ (fig. 12), where the gas is washed free of ammonia and part of the sulphuretted hydrogen and carbon dioxide with water. The scrubbers are tower-like vessels filled with coke or charcoal through which the gas passes from below upwards, encountering a spray of water. Several scrubbers in series are used, so that the water constantly becomes richer in ammonia. Mechanical scrubbers are much used, so-called standard washers; they are rotating, horizontal cylinders having several chambers filled with staves of wood half dipping in water. In them the same principle of making the gas meet an opposing stream of water is employed, so that the last traces of ammonia are removed from the gas. The various purifying apparatus through which the gas has to pass cause considerable resistance to its flow. Escape in various ways would occur had the gas to overcome it by its own pressure, and too long contact of the gas with the hot walls of the retorts would be detrimental. Hence an exhauster is applied to the system which keeps the pressure to the right proportion in the retorts and drives on the gas. [Illustration: FIG. 12.—Washer or Scrubber] After purification in the scrubbers _dry purification_ follows, having for its object especially removal of compounds of sulphur and cyanogen and carbon dioxide. To effect this several shallow receptacles are used, each having a false bottom upon which the purifying material is spread out. The boxes are so arranged that the gas first passes through purifying material which is almost saturated and finally through fresh material, so that the material becomes richer in sulphur and cyanogen compounds. The _gas purifying material_ formerly used was slaked lime, and it is still frequently used, but more generally bog iron ore or artificially prepared mixtures are used consisting mostly of oxide of iron. The saturated purifying material is regenerated by oxidation on spreading it out in the air and turning it frequently. After having been thus treated some ten times the mass contains 50 per cent. sulphur, and 13 to 14 per cent. ferrocyanide. [Illustration: FIG. 13.—Manufacture of Illuminating Gas. Diagrammatic view (_after Lueger_) A Retort setting and hydraulic main; B Condensers and coolers; C Exhauster; D Well; E Water tank; F Tar extractor; G Scrubber; H Purifier; I Station meter; K Gas holder; L Pressure regulator.] The _naphthalene_ in illuminating gas does not separate in the condenser, and therefore is generally treated in special apparatus by washing the gas with heavy coal tar. The gas purified, as has been described, is measured by a meter and stored in gasometers. These are bells made up of sheet iron which hang down into walled receptacles filled with water to act as a water seal, and are raised by the pressure of the gas which streams into them. The gas passes to the network of mains by pressure of the weight of the gasometer, after having passed through a pressure regulating apparatus. As to recovery of bye-products in the illuminating gas industry, see the sections on Ammonia, Cyanogen Compounds, Tar, Benzene, &c. EFFECT ON HEALTH.—Opinions differ as to the effect on health which employment in gas works exerts. This is true of old as well as of modern literature. Hirt[1] maintains that gas workers suffer no increase in illness because of their employment. They reach, he says, a relatively high age and their mortality he puts down at from 0·5 to 1 per cent. (my own observations make me conclude that the average mortality among persons insured in sick societies in Bohemia is 1 per cent., so that Hirt’s figure is not high). Layet[2] agreed with Hirt, but was of opinion that gas workers suffered from anæmia and gastro-intestinal symptoms attributable to inhalation of injurious gases. The sudden symptoms of intoxication, ‘exhaustion and sinking suddenly into a comatose condition,’ which he attributes to the effect of hydrocarbons and sulphuretted hydrogen gas, may well have been the symptoms of carbonic oxide poisoning. Goldschmidt[3] in recent literature considers manufacture of illuminating gas by no means dangerous or unhealthy, and speaks of no specific maladies as having been observed by him. Nevertheless, he admits with Layet that the men employed in the condensing and purifying processes are constantly in an atmosphere contaminated by gas, and that the cleaning and regeneration of the purifying mass is associated with inflammation of the eyes, violent catarrh, and inflammation of the respiratory passages, since, on contact of the purifying mass with the air, hydrocyanic acid gas, sulphocyanic acid gas, and fumes containing carbolic, butyric, and valerianic acids are generated. Other writers[4] refer to the injurious effects from manipulating the purifying material. In general, though, they accept the view, without however producing any figures, that work in gas works is unattended with serious injury to health and that poisonings, especially from carbonic oxide, are rare. Such cases are described,[5] but the authors are not quite at one as to the healthiness or otherwise of the industry. The one opinion is based on study of the sick club reports for several years of a large gas works employing some 2400 workers (probably Vienna).[6] The average frequency of sickness (sickness percentage), excluding accidents, was 48·7 per cent. The conclusion is drawn that the health conditions of gas workers is favourable. It is pointed out, however, that diseases of the respiratory and digestive organs (12·8 and 10·16 per cent. of the persons employed) are relatively high, and that the mortality (1·56 per cent.) of gas-workers is higher than that of other workers. This is attributed to the constant inhalation of air charged with injurious gases. Work at the retorts, coke quenching, and attending to the purifying plant are considered especially unhealthy. The other figures relate to the Magdeburg gas works; they are higher than those quoted. The morbidity of the gas workers was found to be 68·5 per cent., of which 18 per cent. was due to disease of the digestive system, 20·5 per cent. to disease of the respiratory organs, and 1 per cent. to poisoning. No details of the cases of poisoning are given. Carbonic oxide poisoning is said to be not infrequent, the injurious effect of cleaning the purifiers is referred to, and poisoning by inhalation of ammonia is reported as possible. Still, no very unfavourable opinion is drawn as to the nature of the work. The sickness frequency in sick clubs is about 50 per cent., and even in well-managed chemical works Leymann has shown it to be from 65 to 80 per cent. The recently published elaborate statistics of sickness and mortality of the Leipzig local sickness clubs[7] contain the following figures for gas workers: Among 3028 gas workers there were on an average yearly 2046 cases of sickness, twenty deaths, and four cases of poisoning. The total morbidity, therefore, was 67·57 per cent., mortality 0·66 per cent., and the morbidity from poisoning 0·13 per cent. Diseases of the respiratory tract equalled 10·63 per cent., of the digestive tract 10·87 per cent., of the muscular system 13·10 per cent., and from rheumatism 11·10 per cent. These figures, therefore, are not abnormally high and the poisoning is very low. Still, industrial cases of poisoning in gas works are recorded. Of these the most important will be mentioned. Six persons were employed in a sub-station in introducing a new sliding shutter into a gas main, with the object of deviating the gas for the filling of balloons. A regulating valve broke, and the gas escaped from a pipe 40 cm. in diameter. Five of the men were rendered unconscious, and resuscitation by means of oxygen inhalation failed in one case. In repairing the damage done two other cases occurred.[8] In emptying a purifier a worker was killed from failure to shut off the valve. Besides poisoning from illuminating gas, industrial poisoning in gas works is described attributable, in part at least, to ammonia. Thus the report of the factory inspectors of Prussia for 1904 narrates how a worker became unconscious while superintending the ammonia water well, fell in, and was drowned. A further case is described in the report of the Union of Chemical Industry for 1904. In the department for concentrating the gas liquor the foreman and an assistant on the night shift were getting rid of the residues from a washer by means of hot water. The cover had been removed, but, contrary to instructions, the steam had not been shut off. Ammonia fumes rushed out and rendered both unconscious, in which condition there were found by the workmen coming in the morning.[9] In the preparation of ammonium sulphate, probably in consequence of too much steam pressure, gas liquor was driven into the sulphuric acid receiver instead of ammonia gas. The receiver overflowed, and ammonia gas escaped in such quantity as to render unconscious the foreman and two men who went to his assistance.[10] The use of illuminating gas in industrial premises can give rise to poisoning. Thus the women employed in a scent factory, where so-called quick gas heaters were used, suffered from general gas poisoning.[11] In Great Britain in 1907 sixteen cases of carbonic oxide poisoning from use of gas in industrial premises were reported. COKE OVENS Coke is obtained partly as a residue in the retorts after the production of illuminating gas. Such _gas coke_ is unsuitable for metallurgical purposes, as in the blast furnace. Far larger quantities of coal are subjected to dry distillation for metallurgical purposes in coke ovens than in gas works. Hence their erection close to blast furnaces. In the older form of coke oven the bye-products were lost. Those generally used now consist of closed chambers heated from the outside, and they can be divided into coke ovens which do, and those which do not, recover the bye-products. These are the same as those which have been considered under manufacture of illuminating-gas—tar, ammonia, benzene and its homologues, cyanogen, &c. In the coke ovens in which the bye-products are not recovered the gases and tarry vapours escaping on coking pass into the heating flues, where, brought into contact with the air blast, they burn and help to heat the oven, while what is unused goes to the main chimney stack. [Illustration: FIG. 14.—Distillation Coke Oven (_after Lueger_) A, A´ Coal to be coked; B, B´ Standpipes; C Hydraulic main; D Condensing apparatus; E Purified gas: F, F´ Air inlets; G G,´ G´´ Combustion chambers.] In the modern _distillation ovens_ with recovery of the bye-products the gases escaping from the coal are led (air being cut off as completely as possible) through ascending pipes into the main collector, where they are cooled, and the tarry ingredients as well as a part of the ammonia are absorbed by water; subsequently the gases pass through washing apparatus with a view to as complete a recovery of the ammonia and benzene as possible. The purified gases are now again led to the ovens and burnt with access of air in the combustion chambers between two ovens. Generally these ovens are so constructed as to act as non-recovery ovens also (especially in starting the process). The coal is charged into the ovens through charge holes on the top and brought to a level in the chambers either by hand or mechanically. Removal of the coke block after completion of the coking operation is done by a shield attached to a rack and pinion jack. Afterwards the coke is quenched with water. Recovery of the _bye-products_ of coke distillation ovens is similar to the method described for illuminating gas, i.e. first by condensation with aid of air or water cooling, then direct washing with water (generally in scrubbers), whereby tar and ammonia water are recovered. _Recovery of benzene_ and its homologues (see Benzene later) depends on the fact that the coke oven gases freed from tar and ammonia are brought into the closest possible contact with the so-called wash oils, i.e. coal tar oils with high boiling-point (250-300° C.). For this purpose several washing towers are employed. The waste oil enriched with benzene is recovered in stills intermittently or continuously and used again. EFFECTS ON HEALTH.—Injury to health from work at coke ovens is similar to that in the manufacture of illuminating gas. There is the possibility of carbonic oxide poisoning from escape of gas from leakage in the apparatus. As further possible sources of danger ammonia, cyanogen and sulpho-cyanogen compounds, and benzene have to be borne in mind. In the distillation of the wash oil severe poisoning can arise, as in a case described, where two men were fatally poisoned in distilling tar with wash oil.[1] The details of the case are not without interest. The poisoning occurred in the lavatory. The gases had escaped from the drain through the ventilating shaft next to the closet. The gases came from distillation of the mixture of tar and wash oil, and were driven by means of air pumps in such a way that normally the uncondensed gases made their way to the chimney stack. On the day of the accident the pumps were out of use, and the gases were driven by steam injectors into the drain. Analysis showed the gases to contain much sulphuretted hydrogen. When this was absorbed, a gas which could be condensed was obtained containing carbon bisulphide and hydrocarbons of unknown composition (? benzene). Only traces of cyanogen and sulpho-cyanogen compounds were present. Physiological experiment showed that poisoning was attributable mainly to sulphuretted hydrogen gas, but that after this was removed by absorption a further poisonous gas remained. Other Kinds of Power and Illuminating Gas _Producer gas_ or _generator gas_.—Manufacture of producer gas consists in dealing separately with the generation of the gas and the combustion of the gases which arise. This is effected by admitting only so much air (primary air supply) to the fuel as is necessary to cause the gases to come off, and then admitting further air (secondary supply) at the point where the combustion is to take place; this secondary supply and the gas formed in the gas producer are heated in regenerators before combustion by bringing the gases to be burnt into contact with _Siemens’s heaters_, of which there are four. Two of these are always heated and serve to heat the producer gas and secondary air supply. [Illustration: FIG. 15.—Horizontal Regenerative Grate (_after Lueger_)] A producer gas furnace, therefore, consists of a gas producer, a gas main leading to the furnace hearth, the heater, and the chimney. [Illustration: FIG. 16.—Step Regenerative Grate (_after Lueger_)] The gas producer is a combustion chamber filled with coal in which the coal in the upper layer is burnt. Generators may have horizontal or sloping grate (see figs. 15 and 16). The _Siemens’s_ heaters or regenerators are chambers built of, and filled loosely with, fireclay bricks and arranged in couples. Should the gas producers become too hot, instead of the chambers subdivided air heaters are used, whereby the hot furnace gases are brought into contact with a system of thin-walled, gastight fireclay pipes, to which they give up their heat, while the secondary air supply for the furnace is led beside these pipes and so becomes heated indirectly. Previous heating of the producer gas is here not necessary; no valves are needed because the three streams of gas all pass in the same direction. [Illustration: FIG. 17A.—Siemens’s Regenerative Furnace L Air; G Gas FIG. 17B.—Siemens’s Regenerative Furnace] Such air heating arrangements are used for heating the retorts in gas works, for melting the ‘metal’ in glass works, and very generally in other industries, as they offer many technical and hygienic advantages. Generator gas from coke contains 34 per cent. carbonic oxide, 0·1 per cent. hydrogen, 1·9 per cent. carbon dioxide, and 64 per cent. nitrogen. _Blast furnace gas._—Blast furnace gas is formed under the same conditions as have been described for generator gas; it contains more carbon dioxide (about 10 per cent.). (Further details are given in the section on Iron—Blast Furnaces.) _Water gas._—Water gas is made by the passage of steam through incandescent coal, according to the equation: C + H₂O = CO + 2H. The iron gas producer, lined with firebrick, is filled with anthracite or coke and heated by blowing hot air through it. This causes producer gas to escape, after which steam is blown through, causing water gas to escape—containing hydrogen and carbonic oxide to the extent of 45-50 per cent., carbon dioxide and nitrogen 2-6 per cent., and a little methane. The blowing of hot air and steam is done alternately, and both kinds of gas are led away and collected separately, the water gas being previously purified in scrubbers, condensers, and purifiers. It serves for the production of high temperatures (in smelting of metals). Further, when carburetted and also when carefully purified in an uncarburetted state, it serves as an illuminant. The producer gas generated at the same time is used for heating purposes (generally for heating boilers). _Dowson gas._—Dowson gas is obtained by collecting and storing together the gases produced in the manner described for water gas. Under the grating of the wrought-iron gas producer (lined with firebrick and similarly filled with coke or anthracite) a mixture of air and steam, produced in a special small boiler, is blown through by means of a Körting’s injector. Before storage the gas is subjected to a purifying process similar to that in the case of water gas. The mixed gas consists of 1 vol. water gas and 2-3 vols. producer gas, with about 10-15 vols. per cent. H, 22-27 vols. per cent. CO, 3-6 per cent. CO₂, and 50-55 per cent. N. It is an admirable power gas for driving gas motors (fig. 18). _Mond gas_ similarly is a mixed gas obtained by blowing much superheated steam into coal at low temperature. Ammonia is produced at the same time. [Illustration: FIG. 18.—Power Gas Installation (_after Lueger_) A Steam boiler a Steam injector B Furnace b Charging hopper c Cover g d Valve C e Cock D f Vent pipe g Steam Pipe C Washer D Coke tower E Sawdust purifier] _Suction gas._—In contradistinction to the Dowson system, in which air mixed with steam is forced into the producer by a steam injector, in the suction gas plant the air and steam are drawn into the generator by the apparatus itself. The whole apparatus while in action is under slight negative pressure. A special steam boiler is unnecessary because the necessary steam is got up in a water container surrounding or connected with the cover of the generator. The plant is set in motion by setting the fire in action by a fan. [Illustration: FIG. 19.—Suction Gas Plant (_after Meyer_)] Fig. 19 shows a suction gas plant. B is the fan. Above the generator A and at the lower part of the feed hopper is an annular vessel for generating steam, over the surface of which air is drawn across from the pipe e, passing then through the pipe f into the ash box g, and then through the incandescent fuel. The gas produced is purified in the scrubber D, and passes then through a pipe to the purifier containing sawdust and to the motor. _Carburetted gas._—Gas intended for illuminating purposes is carburetted to increase its illuminating power, i.e. enriched with heavy hydrocarbons. Carburetting is effected either by a hot method—adding the gases distilled from mineral or other oils—or by a cold method—allowing the gas to come into contact with cold benzol or benzine. Coal gas as well as water gas is subjected to the carburetting process, but it has not the same importance now in relation to illuminating power, as reliance is more and more being placed on the use of mantles. ACETYLENE _Calcium carbide._—Acetylene is prepared from calcium carbide, which on contact with water gives off acetylene. _Calcium carbide_ is prepared electro-chemically. A mixture of burnt lime and coke is ground and melted up together at very high temperature in an electric furnace, in doing which there is considerable disengagement of carbonic oxide according to the equation: CaO + 3C = CaC₂ + CO. The furnaces used in the production of calcium carbide are of different construction. Generally the furnace is of the nature of an electric arc, and is arranged either as a crucible furnace for intermittent work or like a blast furnace for continuous work. Besides these there are resistance furnaces in which the heat is created by the resistance offered to the passage of the current by the molten calcium carbide. The carbonic oxide given off in the process causes difficulty. In many furnaces it is burnt and so utilised for heating purposes. The calcium carbide produced contains as impurities silicon carbide, ferro-silicon, calcium sulphide, and calcium phosphide. _Acetylene_ (C₂H₂), formed by the decomposition of calcium carbide by means of water (CaC₂ + 2H₂O = Ca(OH)₂ + C₂H₂), furnishes when pure an illuminating gas of great brilliancy and whiteness. Its production is relatively easy. Used for the purpose are (1) apparatus in which water is made to drop on the carbide, (2) apparatus in which the carbide dips into water and is removed automatically on generation of the gas, (3) apparatus in which the carbide is completely immersed in water, and (4) apparatus in which the carbide in tiny lumps is thrown on to water. These are diagrammatically represented in figs. 20A to 20D. [Illustration: FIG. 20A. FIG. 20B. FIG. 20C. FIG. 20D. Acetylene Apparatus—diagrammatic (_after Lueger_) A Dripping; B Dipping; C Submerging; D Throwing in] The most important impurities of acetylene are ammonia, sulphuretted hydrogen gas, and phosphoretted hydrogen. Before use, therefore, it is subjected to purification in various ways. In Wolf’s method the gas is passed through a washer (with the object of removing ammonia and sulphuretted hydrogen gas) and a purifying material consisting of chloride of lime and bichromate salts. In Frank’s method the gas passes though a system of vessels containing an acid solution of copper chloride, and also through a washer. Chloride of lime with sawdust is used as a purifying agent. Finally, the gas is stored and thence sent to the consumer (see fig. 21). [Illustration: FIG. 21.—Acetylene Gas Apparatus (_after Lueger_)] EFFECTS ON HEALTH.—Almost all the poisoning caused in the industries in question is due to carbonic oxide gas, of which water gas contains 41 per cent., generator gas 35 per cent., and suction and Dowson gas 25 per cent. That industrial carbonic oxide poisoning is not rare the reports of the certifying surgeons in Great Britain sufficiently show. In the year 1906 fifty-five persons are referred to as having suffered, with fatal issue in four. In 1907 there were eighty-one, of which ten were fatal. Of the 1906 cases twenty resulted from inhalation of producer, Mond, or suction gas, sixteen from coal gas (in several instances containing carburetted water gas), seventeen from blast furnace gas, and one each from charcoal fumes from a brazier, and from the cleaning out of an oil gas holder. As causes of the poisoning from suction gas were (1) improper situation of gas plant in cellar or basement, allowing gas to collect or pass upward; (2) defective fittings; (3) starting the suction gas plant by the fan with chimney valve closed; (4) cleaning out ‘scrubbers’ or repairing valves, &c.; (5) defective gasometer. In the seventeen cases due to blast furnace gas six were due to conveyance of the gas by the wind from a flue left open for cleaning purposes into an engineering shed, two to charging the cupola furnace, two to entering the furnace, and four to cleaning the flues. The following are instances taken from recent literature on gas poisoning[1]: Several cases of poisoning by _water gas_ occurred in a smelting works. The poisoning originated when a blowing machine driven by water gas was started. Owing to premature opening of the gas valve two men employed in a well underneath the machine were overcome. The attendant who had opened the valve succeeded in lifting both from the well; but as he was trying to lift a third man who had come to his assistance and fallen into the well he himself fell in and was overcome. The same fate befell the engineer and his assistant who came to the rescue. All efforts to recover the four men by others roped together failed, as all of them to the number of eight were rendered unconscious. With the aid of rescue appliances (helmets, &c.) the bodies were recovered, but efforts at artificial respiration failed. A workman was killed by _suction gas_ while in the water-closet. It appeared that some time previously when the plant was installed the ventilating pipe between the purifier and motor, instead of being led through the roof, had been led out sideways on a level with the floor immediately above the closet. In another case the suction gas attendant had taken out the three-way cock between the generator and motor for repairs and had not reinserted it properly, so that when effort was made to start the motor this failed, as gas only and no air was drawn in. The motor was thought to be at fault, and the fan was worked so vigorously that the gas forced its way out through the packing of the flange connections and produced symptoms of poisoning in the persons employed. More dangerous than suction gas plants, in which normally no escape takes place, are installations depending on gas _under pressure_. Such an installation was used for heating gas irons in a Berlin laundry. The arrangements were considered excellent. The gas jets were in stoves from which the fumes were exhausted. The gas was made from charcoal and contained 13 per cent. of hydrogen. No trace of carbonic oxide was found in the ironing room on examination of the air. After having been in use for months the mechanical ventilation got out of order, with the result that twelve women suffered severely from symptoms of carbonic oxide poisoning, from which they were brought round by oxygen inhalation. The laundry reverted to the use of illuminating gas. The conclusion to be drawn is that installations for gas heating are to be used with caution.[2] Industrial poisoning from _blast furnace gas_ is frequent. Two fatal cases were reported[3] in men employed in the gas washing apparatus. They met their death at the manhole leading to the waste-water outlet. In another case a workman entered the gas main three hours after the gas had been cut off to clear it of the dust which had collected. He succumbed, showing that such accumulations can retain gas for a long time. Steps had been taken three hours previously to ventilate the portion of gas main in question. A fatal case occurred in the cleaning out of a blast furnace flue which had been ventilated for 1½ hours by opening all manholes, headplates, &c. The foreman found the deceased with his face lying in the flue dust; both he and a helper were temporarily rendered unconscious. Cases of poisoning by _generator gas_ are described.[4] A workman who had entered a gasometer containing the gas died in ten minutes, and another remained unconscious for ten days and for another ten days suffered from mental disturbance, showing itself in hebetude and weakness of memory. _Acetylene_ is poisonous to only a slight extent. Impurities in it, such as carbon bisulphide, carbonic oxide (present to the extent of 1-2 per cent.), and especially phosphoretted hydrogen gas, must be borne in mind. American calcium carbide[5] yields acetylene containing 0·04 per cent. of phosphoretted hydrogen; Lunge and Cederkreutz have found as much as 0·06 per cent. in acetylene. AMMONIA AND AMMONIUM COMPOUNDS PREPARATION.—Ammonia and ammonium salts are now exclusively obtained as a bye-product in the dry distillation of coal, from the ammonia water in gas works, and as a bye-product from coke ovens. The ammonia water of gas works contains from 2-3 per cent. of ammonia, some of which can be recovered on boiling, but some is in a non-volatile form, and to be recovered the compound must be decomposed. The volatile compounds are principally ammonium carbonate and, to a less extent, ammonium sulphide and cyanide; the non-volatile compounds are ammonium sulphocyanide, ammonium chloride, sulphate, thiosulphate, &c. Other noteworthy substances in ammonia water are pyridine, pyrrol, phenols, hydrocarbons, and tarry compounds. Decomposition of the non-volatile compounds is effected by lime. Hence the ammonia water is distilled first alone, and then with lime. The distillate is passed into sulphuric acid, ammonium sulphate being formed. Distillation apparatus constructed on the principle usual in rectifying spirit is used, so that continuous action is secured; the ammonia water flows into the apparatus continuously and is freed of the volatile compounds by the steam. At a later stage milk of lime is added, which liberates the ammonia from the nonvolatile compounds. Of the ammonium salts there require mention: _Ammonium sulphate_ ((NH₄)₂SO₄), which serves for the production of other ammonium salts. It is usually centrifugalised out from the sulphuric acid tank previously described. _Ammonium chloride_ (sal-ammoniac, NH₄Cl) is formed by bringing the ammonia fumes given off in the process described in contact with hydrochloric acid vapour. The crude salt so obtained is recrystallised or sublimed. _Ammonium phosphate_ ((NH₄)₂HPO₄) is made in an analogous manner by leading ammonia into phosphoric acid. It is useful as an artificial manure. _Ammonium carbonate_ is made either by bringing together ammonia vapour and carbonic acid or by subliming ammonium sulphate with calcium carbonate. It is very volatile. The thick vapour is collected and purified in leaden chambers. [Illustration: FIG. 22.—Preparation of Ammonia. Column Apparatus of Feldman (_after Ost_) A, B, C Columns; D Saturator; (a) Settling tank and regulator for flow of ammonia; (b) Economiser; (f) Milk of lime; (g) Pump] _Caustic ammonia_ is prepared either from gas liquor or, more usually, from ammonium sulphate by distillation with caustic alkali in a continuous apparatus. USE OF AMMONIA.—Ammonia is used in laundries and bleaching works in dyeing and wool washing. It is used especially in making ammonium salts, in the preparation of soda by the Solvay process (see Soda Manufacture), and in making ice artificially. It is used also in the preparation of indigo, in lacquers and colours, and the extraction of chloride of silver, &c. EFFECTS ON HEALTH.—Industrial ammonia poisoning is rare. It occurs most frequently in gas works and occasionally in its use, especially the manufacture of ammonium salts. Those engaged in subliming ammonium carbonate incur special risk, but often it is not the ammonia vapour so much as the escaping evil-smelling gases containing carbon bisulphide and cyanogen compounds which are the source of trouble. Occasionally in the production of ice through leakage or by the breaking of carboys of ammonia accidental poisoning has occurred. Some cases are cited from recent literature: A worker was rendered unconscious and drowned in an ammonia water well.[1] Two workers were poisoned (one fatally) in the concentration of gas liquor. Three workers were gassed (one fatally) in the preparation of ammonium sulphate in a gas works. Probably as the result of excessive steam pressure gas water was driven over with the ammonia into the sulphuric acid vessel.[2] Eulenberg[3] reports the occurrence of sulphuretted hydrogen gas poisoning in the production of ammonium salts. The workers succumbed as though shot, although work was being carried on in the open air. They recovered when removed from the poisonous atmosphere. In a large room of a chemical factory phosphoric acid was being saturated with ammonia gas water in an iron lead-lined vessel. Carbonic acid gas and hydrogen gas were evolved, but not to such extent as to be noticeable in the large room. A worker not employed in the room had to do something close to the vessel, and inhaled some of the fumes given off. A few yards from the vessel he was found lying unconscious, and although removed into the open air failed to respond to the efforts at artificial respiration.[4] Lewin, in an opinion delivered to the Imperial Insurance Office, describes poisoning in a man who during two days had been employed repairing two ammonia retorts in a chemical factory. On the evening of the second day he suffered from severe symptoms of catarrh, from which he died five days later. Lewin considered the case to be one of acute ammonia poisoning.[5] Ammonia is frequently used in _fulling_ cloth, the fumes of which collect on the surface after addition of sulphuric acid to the settling vats. This is especially liable to occur on a Monday, owing to the standing of the factory over the Sunday, so that entrance into the vats without suitable precautions is strictly forbidden. Despite this, a worker did go in to fetch out something that had fallen in, becoming immediately unconscious. A rescuer succumbed also and lost his life. The first worker recovered, but was for long incapacitated by paralytic symptoms. Cases of poisoning in _ice factories_ and refrigerator rooms from defective apparatus are reported. Acute and chronic poisoning among sewer men are due mainly to sulphuretted hydrogen gas and only partly to ammonia. The more ammonia and the less sulphuretted hydrogen sewer gases contain the less poisonous are they. CYANOGEN COMPOUNDS TREATMENT OF THE MATERIALS USED IN GAS PURIFYING.—Cyanogen compounds are still sometimes prepared by the original method of heating to redness nitrogenous animal refuse (blood, leather, horn, hair, &c.) with potash and iron filings; potassium cyanide is formed from the nitrogen, carbon, and alkali, and this with the sulphur and iron present is easily converted into potassium ferrocyanide (yellow prussiate of potash, K₄FeC₆N₆) by lixiviation of the molten mass. It crystallises out on evaporation. Cyanogen compounds are obtained in large quantity from the material used in purifying the gas in gas works. This saturated spent material contains, in addition to 30-40 per cent. of sulphur, 8-15 per cent. of cyanogen compounds and 1-4 per cent. of sulphocyanogen compounds. By lixiviation with water the soluble ammonium salts are extracted from the purifying material. This solution furnishes _sulphocyanide of ammonium_, from which the remaining unimportant sulphocyanide compounds are obtained (used in cloth printing). The further treatment of the purifying material for potassium ferrocyanide is rendered difficult because of the sulphur, which is either removed by carbon bisulphide and the ferrocyanide obtained by treatment with quicklime and potassium chloride, or the mass is mixed with quicklime, steamed in closed vessels, lixiviated with water, and decomposed by potassium chloride; ferrocyanide of potassium and calcium separates out in crystals, and this, treated with potash, yields potassium ferrocyanide. The well-known non-poisonous pigment Prussian blue is obtained by decomposing ferrocyanide of potash with chloride or oxide of iron in solution. _Potassium cyanide_ (KCN) is prepared from potassium ferrocyanide by heating in absence of air, but it is difficult to separate it entirely from the mixture of iron and carbon which remains. All the cyanogen is more easily obtained in the form of potassium and sodium cyanide from potassium ferrocyanide by melting it with potash and adding metallic sodium. The very poisonous _hydrocyanic acid_ (prussic acid, HCN) is formed by the action of acids on potassium or sodium cyanide; small quantities indeed come off on mere exposure of these substances to the air. The increasing demand for potassium cyanide has led to experimental processes for producing it synthetically. One method consists in the production of potassium cyanide from potash and carbon in a current of ammonia gas. Small pieces of charcoal are freed from air, saturated with a solution of potash, dried in the absence of air, and heated in upright iron cylinders to 100° C., while a stream of ammonia gas is passed through. Again, sodium cyanide is prepared from ammonia, sodium, and carbon by introducing a definite amount of sodium and coal dust into melted sodium cyanide and passing ammonia through. The solution is then concentrated in vacuo and sodium cyanide crystallises out on cooling. USE OF CYANIDES.—Potassium cyanide is principally used in the recovery of gold, in gold and silver electroplating, in photography, for soldering (it reduces oxides and makes metallic surfaces clean), for the production of other cyanogen compounds, for the removal of silver nitrate stains, &c. Hydrocyanic acid gas is given off in electroplating, photography, in smelting fumes, in tanning (removing hair by gas lime), &c. EFFECTS ON HEALTH.—Industrial cyanogen poisoning is rare. Weyl[1] states that he could find no case in any of the German factory inspectors’ reports for the twenty years prior to 1897, nor in some twenty-five volumes of foreign factory inspectors’ reports. I have found practically the same in my search through the modern literature. Of the very few references to the subject I quote the most important. A case of (presumably) chronic hydrocyanic acid poisoning is described in a worker engaged for thirteen years in silver electroplating of copper plates.[2] The plates were dipped in a silver cyanide solution and then brushed. After two years he began to show signs of vomiting, nausea, palpitation, and fatigue, which progressed and led to his death. A case of sudden death is described[3] occurring to a worker in a sodium cyanide factory who inhaled air mixed with hydrocyanic acid gas from a leaky pipe situated in a cellar. The factory made sodium cyanide and ammonium sulphate from the residue after removal of the sugar from molasses. This is the only definite case of acute cyanogen poisoning in a factory known to me. I believe that under modern conditions, in which the whole process is carried on under negative pressure, chance of escape of cyanogen gases is practically excluded. It should be mentioned that hydrocyanic acid vapour is given off in the burning of celluloid. In this way eight persons were killed at a fire in a celluloid factory.[4] Skin affections are said to be caused by contact with fluids containing cyanogen compounds, especially in electroplating. It is stated that workers coming into contact with solutions containing cyanides may absorb amounts sufficient to cause symptoms, especially if the skin has abrasions. Such cases are described.[5] In electroplating, further, in consequence of the strong soda solutions used, deep ulceration and fissures of the skin of the hand can be caused. COAL TAR AND TAR PRODUCTS Of the products of the illuminating gas industry tar has considerably the most importance. Coal tar as such has varied use in industry, but far greater use is made of the products obtained by fractional distillation from it such as benzene, toluene, naphthalene, anthracene, carbolic acid, pyridine, and the other constituents of tar, a number of which form the starting-point in the production of the enormous coal-tar dye industry. Especially increasing is the consumption of benzene. In Germany alone this has increased in ten years from 20 to 70 million kilos. This is partly due to the need of finding some cheap substitute for benzine, the consumption and cost of which has increased, and it has in many respects been found in benzene. Besides benzene and its homologues, toluene, anthracene, and naphthalene are valuable. Anthracene is used in the manufacture of alizarine and naphthalene in that of artificial indigo and of the azo-colours. Carbolic acid (phenol) and the homologous cresols serve not only as disinfectants but also in the manufacture of numerous colours and in the preparation of picric acid and salicylic acid. Further, a number of pharmaceutical preparations and saccharin are made from the constituents of tar. The important _constituents of tar_ are: 1. Hydrocarbons of the methane series: paraffins, olefines; hydrocarbons of the aromatic series: benzene and its homologues, naphthalene, anthracene, phenanthrene, &c. 2. Phenols (cresols, naphthols). 3. Sulphides: sulphuretted hydrogen, carbon bisulphide, mercaptan, thiophene. 4. Nitrogen compounds: ammonia, methylamine, aniline, pyridine, &c. 5. Fifty to sixty per cent. of tar consists of pitch constituting a mixture of many different substances which cannot be distilled without decomposition. _Crude tar_, i.e. tar which separates in the dry distillation of coal, is employed as such for preserving all kinds of building materials, for tarring streets, as plastic cement, as a disinfectant, in the preparation of roofing paper or felt, lampblack, briquettes, &c. _Brattice cloth_ and _roofing felt_ are made by passing the materials through hot tar and incorporating sand with them; in doing this heavy fumes are given off. _Lampblack_ is made by the imperfect combustion of tar or tar oil by letting them drop on to heated iron plates with as limited an air supply as possible; the burnt gases laden with carbon particles are drawn through several chambers or sacks in which the soot collects. [Illustration: FIG. 23.—Tar Still (_after Krämer_)] _Briquettes_ (patent fuel) are made by mixing small coal (coal dust) with tar or pitch and then pressing them in moulds. The separation and recovery of the valuable ingredients is effected by _fractional distillation_. This is carried out by heating the tar at gradually increasing temperature in a wrought-iron still, the bottom of which is arched and having a cast-iron still head, or in horizontal boilers by direct fire. Before commencing the distillation the tar is freed as far as possible of water by storage. On gradual increase of temperature the volatile constituents, the so-called ‘light oil,’ and later the heavier volatile constituents come over. The constituents are liberated in a gaseous state and are collected in fractions. The pitch remains behind in the still. Considerable quantities of coal tar are not distilled for pitch. Often the light oils and a portion of the heavy oils are collected, when soft pitch remains, or, if the light oils and only a very small portion of the heavy oils are collected, _asphalt_ remains behind, this residue being used as a basis for the manufacture of roofing felt. The vapours are condensed in iron coils round which cold water circulates. The receivers in which the distillate is caught are changed at definite times as the temperature gradually rises. If five fractions have come over they are called (1) first runnings, (2) light oil to 170° C., (3) middle oil (carbolic oil to 230° C.), (4) heavy oil to 270° C., and lastly (5) anthracene oil, which distills at over 270° C.; the pitch remaining behind is let out of the still by an opening at the bottom. We will briefly sketch the further treatment and use of these fractions, so far as a knowledge of the most important processes is necessary for our purpose. 1. The _light oils_ (including first runnings) coming over up to 170° C. are again distilled and then purified with sulphuric acid in lead-lined cast-iron or lead-lined wooden tanks. The dark-coloured acid used for purifying after dilution with water, which precipitates tarry matters, is treated for ammonium sulphate; the basic constituents of the light oils extracted with sulphuric acid and again liberated by lime yield _pyridine_ (C₅H₅N) and the homologous pyridine bases, a mixture of which is used for denaturing spirit. After the light oils have been washed with dilute caustic soda liquor, whereby the phenols are removed, they are separated by another fractional distillation into (_a_) crude benzol (70°-130° C.) and (_b_) solvent naphtha (boiling-point 130°-170° C.). _Crude benzol_ (70°-140° C.) consists chiefly of benzene and toluene and is separated into its several constituents in special rectifying apparatus. For this production of pure benzene (boiling-point 80°-82° C.) and pure toluene (boiling-point 110° C.) fractionating apparatus is used (fig. 24). The _commercial products_ in use which are obtained from the fractional distillation of the light oil are: (_a_) _Ninety per cent. benzol_, so called because in the distillation 90 per cent, should come over at a temperature of 100° C. It is made up of 80-85 per cent. benzene, 13-15 per cent. toluene, 2-3 per cent. xylene, and contains, as impurities, traces of olefines, paraffins, sulphuretted hydrogen, and other bodies. (_b_) _Fifty per cent. benzol_ contains 50 per cent. of constituents distilling at 100° C. and 90 per cent. at 120° C.; it is a very mixed product, with only 40-50 per cent. of benzene. (_c_) _Solvent naphtha_, so called because it is largely used for dissolving rubber, is free from benzene, but contains xylene and its homologues and other unknown hydrocarbons. [Illustration: FIG. 24.—Column Apparatus of Hickman for Distillation of Benzene (_after Ost_) A Still body; B Analysing column; C Cooler; D Condenser for pure distillate.] Benzol is widely used. Ninety per cent. benzol is largely used in the chemical industry, serving for the preparation of dye stuffs, pharmaceutical preparations, scents, &c. In other industries it took the place of benzine and also of turpentine oil, especially in the paint industry, since it evaporates quickly and readily dissolves resins. Hence it is used in the preparation of quick drying ship’s paints, as a protection against rust, and as an isolating lacquer (acid proof colours) for electrical apparatus, in the production of deck varnishes, and as a solvent of resins. This use of benzol in the paint industry is by no means unattended with danger, as benzol is poisonous. Far less harmful, if not altogether without risk, is use of benzol free solvent naphtha—but this evaporates only slowly and hence cannot take the place of benzol. Benzol serves further for fat extraction from bones in manure factories and of caffein from coffee beans. Again, it is used as a motive power in motor vehicles. The solvent naphtha above mentioned with boiling-point above 140° C. and all the light oils are employed in chemical cleaning and for dissolving indiarubber (see Indiarubber). These are known in the trade erroneously as ‘benzine,’ which unfortunately often leads to confusion with petroleum benzine (see Petroleum) and to mistakes in toxicological accounts of poisoning. 2. Between 150° and 200° C. the _middle oil_ comes over, from which on cooling _naphthalene_ (C₁₀H₈) crystallises out, and is subsequently washed with caustic soda liquor and with acid; it is re-distilled and hot pressed. The remaining liquor yields, when extracted with caustic soda, _phenol_ (carbolic acid, C₆H₅OH), which, on addition of sulphuric acid or carbonic acid, separates from the solution and then—generally in special factories—is obtained pure by distillation and special purifying processes. From the sodium salt of carbolic acid (sodium phenolate) _salicylic acid_ (C₆H₄OH.COOH) is obtained by combination with compressed CO₂ at a temperature of 150° C. _Picric acid_ (trinitrophenol, C₆H₂OH.(NO₂)₃) is obtained by treating phenol with a mixture of sulphuric and nitric acids (nitration). The yellow crystals of this explosive which separate are carefully washed, recrystallised, centrifugalised, and dried. 3. The _heavy oils_ which come over between 200° and 300° C. containing cresols, naphthols, naphthaline, quinoline bases, fluid paraffins, &c., are seldom separated further. The disinfectants lysol, sapocarbolic, &c., are obtained from such fractions. The heavy oils are much in use for _impregnating wood_ (piles, railway sleepers, &c.), to prevent rotting. This is done in special creosoting installations. The wood is first freed from moisture under vacuum and lastly the heavy oil forced in. This is a better means of preserving timber than the analogous method by means of chloride of zinc. 4. _Anthracene oil_ or ‘green oil’ comes over between 300° and 400° C. and contains the valuable anthracene which crystallises out, is separated from the oil in filter presses, or dried in centrifugal machines. _Alizarin_ dyes are made from it. Raw anthracene oil further is used commercially as a paint under the name of carbolineum for preserving wood. 5. The _pitch_ remaining behind in the still serves (like tar) for making varnishes, patent fuel, &c. For our purpose use of pitch in the preparation of iron varnishes which adhere to metals and protect them from oxidation have interest. Pitch and the heavy oils are melted together or, if for thin varnishes, dissolved in solvent naphtha. The volatile constituents evaporate after the coat has been applied. EFFECTS ON HEALTH.—Severe injury to health or poisoning cases scarcely arise through manipulations with or use of tar. Inhalation, however, of large quantities of tar vapour is without doubt unpleasant, as a number of poisonous substances are contained in the fumes. And the ammonia water which separates on standing can give off unpleasantly smelling odours from the sulphur compounds in it, especially if it comes into contact with waste acids, with consequent development of sulphuretted hydrogen gas. I could not find in the literature of the subject references to any clearly proved case of poisoning from tar emanations. But deserving of mention in this connection are the _effects on the skin_ caused by tar. Workers coming into contact with tar suffer from an inflammatory affection of the skin, so-called tar eczema, which occasionally takes on a cancerous (epithelioma) nature similar to chimney-sweep’s cancer, having its seat predominantly on the scrotum. In lampblack workers who tread down the soot in receptacles the malady has been observed to affect the lower extremities and especially the toes. In tar distillation and in the _production_ and _use_ of _benzene_ industrial poisoning frequently occurs. Many cases are recorded, but in several the immediate exciting cause is doubtful, and consequently it is often difficult to classify the cases. Most frequently the manufacture and use of benzene come in question. Besides this, in tar distillation poisoning may be caused by other substances, such as sulphuretted hydrogen gas, carbonic oxide gas, &c. In the production of antipyrin, aspirin, &c., and in the preparation and use of anthracene injury to health is recognised. From the list of recognised cases of these forms of poisoning the most characteristic are chosen from the recent literature on the subject. The Prussian factory inspectors’ reports for 1904 describe the following: In cleaning out a tar still two workers were killed by inhalation of gas. The nature of the gas was not ascertained. But what probably happened was that the cock on the foul gas pipe collecting the gases from the stills leaked and allowed fumes to pass over from one still to another. A foreman and worker were rendered unconscious on entering a receiver for heavy oil for cleaning purposes. On treatment with oxygen gas they speedily recovered. _Industrial benzene poisoning_ is especially frequent now in view of the increasing use to which it is put. Several cases have proved fatal. A worker, for instance, forgot to open the cock for the water to cool the condenser, so that some of the benzene vapour remained uncondensed. The case proved fatal. The Report of the Union of Chemical Industry for 1905 stated that a worker on night duty, whose duty it was to regulate the introduction of steam and the cooling of the benzol plant, was found lying dead in front of the building. Inquiry showed that he had not opened the valve for running the distillate into the appropriate receiver. Eight thousand litres overflowed. In an indiarubber extracting factory a worker was rendered unconscious while inspecting a benzol still; before entering he had omitted to observe the instructions to drive steam through and have a mate on watch at the manhole. Two other workmen were similarly affected who went to the rescue without adoption of precautions. Only one survived. In a further accident (already mentioned under ‘Coke Furnaces’) two workmen were killed. In the factory in question the thick tar from the coke ovens was being distilled under slight pressure. The air pumps, however, were out of order, and temporary use was being made of Körting’s injectors, whereby the steam and tar constituents were cooled and led into the drain in front of the closet, near to which was a ventilating shaft. Probably, in addition to benzene and its homologues, sulphuretted hydrogen and cyanogen compounds were present in the poisonous gases. In cleaning out a benzene extracting apparatus a workman was killed by the stagnant fumes in it. A similar case of benzene poisoning occurred in a naphthalamine works through inspecting an extracting vessel which had contained benzene and naphthalamine and had to be cleaned. The vessel had been empty for twenty-two hours and had been washed and ventilated, but through a leaking pipe benzene had dropped down into it. The workman engaged was rendered unconscious inside the retort, but was rescued by an engineer equipped with a breathing helmet. Others who without such apparatus tried to effect a rescue were overcome, and one who had entered the retort succumbed.[1] Benzene poisoning has often occurred in the cleaning of tanks, &c., for the transport and storage of the substance. The following examples are taken from the Reports of the Union of Chemical Industry. A worker during the pause for breakfast had, unknown to his employer, cleaned out an empty truck for crude benzol. Later he was with difficulty removed unconscious through the manhole and could not be resuscitated. Only a short time previously a similar occurrence had taken place in the same factory. Two further fatal cases were reported in 1908 in the cleaning out of railway tank waggons. The tank had previously been thoroughly sprayed with water. The partition plates which are required in such tanks increase the difficulty of cleaning from the manhole. After the foreman had tested the air by putting his head inside and considered it free from danger, a man entered to clean out the deposit; another man on watch outside had evidently gone in for rescue purposes. Resuscitation in both cases failed. A worker died and several were affected in the cleaning out of a benzol storage tank in a tar distillery. The tank had had air blown through it several weeks before, and had been thoroughly cleaned by steam and water. Also in the inspection the greatest care was taken in only permitting work for short spells. This shows that, notwithstanding great care, the last traces of benzol cannot be entirely removed and that quite small quantities are sufficient to cause severe and even fatal poisoning. Workers should only clean out tanks, therefore, when properly equipped with helmets. In the German factory inspectors’ reports for 1902 a case of intoxication is described in a man who was engaged painting the inside of an iron reservoir with an asphalt paint dissolved in benzol. Of special interest is a fatal case from inhalation of benzol fumes in a rubber factory. Rubber dissolved in benzol was being rubbed into the cloth on a spreading machine in the usual way. The cloth then passes under the cleaning doctor along the long heated plate to the end rolls. Of the three men employed at the process one was found to be unconscious and could not be brought round again. The cases described[2] of poisoning with impure benzol in a pneumatic tyre factory in Upsala are, perhaps, analogous. Here nine young women had severe symptoms, four of whom died. In reference to the cases which occurred in rubber factories it is conceivable that carbon bisulphide played a part, since in such factories not only are mixtures of benzol and carbon bisulphide used, but also frequently the ‘first runnings’ of benzol, which, on account of the high proportion (sometimes 50 per cent.) of carbon bisulphide in them, make an excellent solvent for rubber. From some coke ovens crude benzol was collected in two large iron receivers. They were sunk in a pit projecting very little above the ground. To control the valves the workmen had to mount on the receiver, the manholes of which were kept open during filling. The pit was roofed over and two wooden shafts served both for ventilation and as approaches to the valves. One summer day benzol had been blown in the usual way into a railway truck and a worker had entered the space to control the valves. Some time afterwards he was found in a doubled-up position on the receiver, grasping the valves, from which later he fell off down to the bottom of the pit. Three rescuers entered, but had to retire as they became affected. A fourth worker, in the presence of the manager, was let down by a rope, but succumbed immediately and was dragged up a corpse. Finally, equipped with a smoke helmet, a rescuer brought up the lifeless body of the first man. It was believed that the benzol had distilled over warm and had evaporated to such an extent as to fill with fumes the unsuitably arranged and inadequately ventilated space. Possibly other volatile compounds were responsible for the poisoning.[3] A similar though less serious accident occurred to a foreman who forgot to set the cooling apparatus at work at the commencement of distillation, and became unconscious from the escaping fumes, as also did a rescuer. The latter was brought round by oxygen inhalation, but the former, although alive when recovered, succumbed despite efforts at artificial respiration. A fatal case occurred in an aniline factory where benzol fumes had escaped owing to faulty arrangement of the valves. The worker, although ordered at once to leave the room, was found there ten minutes later dead. Interesting are the following cases of accidents due to use of paints containing benzol. In painting a retort with an anti-corrosive paint called ‘Original Anti-corrosive,’ unconsciousness followed on completion of the painting, but by prompt rescue and medical assistance life was saved. The accident was attributed to benzol fumes from the paint insufficiently diluted by the air coming in at the open manhole. A similar case arose from use of a rust-preventing paint—‘Preolith’—and only with difficulty was the man using it pulled out from the inside of the steam boiler. Although resuscitated by oxygen inhalation, he was incapacitated for eight days. Crude benzol was a constituent of ‘Preolith.’ Obviously use of such paints in closely confined spaces is very risky. The frequency of such poisonings caused Schaefer,[4] Inspector of Factories in Hamburg, to go fully into the question. He lays stress on the dangerous nature of paints containing a high proportion of benzol, but considers use of unpurified constituents with boiling-point between 130°-170° C., such as solvent naphtha, as free from risk (cf. in Part II the experiments on benzene and the commercial kinds of benzol). Schaefer mentions that in 1903 and 1904 cases of unconsciousness from painting the inside of boilers were numerous. The proportion of benzol in the paints was 20-30 per cent. In 1905 and 1906 the cases were attributable rather to inhalation of hydrocarbons in cleaning of apparatus. Use of ‘Dermatin’ affected two painters. One case in 1906 happened to a man painting the double bottom of a ship in Hamburg harbour with ‘Black Varnish Oil’ through the manhole, in doing which he inhaled much of the fumes. This paint consisted of coal-tar pitch in light coal-tar oil, the latter constituent (distilling at 170° C.) amounting to 31-33 per cent. Investigation showed further that the bulk of the tar oil volatilised at ordinary temperatures and so quickly dried. Sulphuretted hydrogen gas was given off on slight warming. The person after using it for some time felt poorly, and then became ill with severe inflammation of the respiratory passages, which proved fatal after twenty-four days. Several similar cases occurred in 1908 and 1909. Painting the inside of a boiler with ‘Auxulin’ caused unconsciousness in four persons, of whom three were rescuers. A fatal case was due to use of a patent colour containing 30-40 per cent. benzol in an entirely closed-in space (chain-well), although the worker was allowed out into fresh air at frequent intervals. A case of chronic industrial xylene poisoning is described in a worker using it for impregnating indiarubber goods. The symptoms were nervous, resembling neurasthenia. Some of the cases of poisoning, especially when severe and fatal, in the production of distillation constituents of coal tar are doubtless attributable to _sulphuretted hydrogen gas_. Thus in England, in the years 1901-3, there were eleven fatal and as many other severe cases reported from tar distilleries, of which the majority were due to sulphuretted hydrogen gas. One case of _carbonic oxide_ poisoning in coal-tar distillation is described.[5] In cleaning out pitch from a still fourteen days after the last distillation a workman succumbed to carbonic oxide poisoning. This is at all events a rare eventuality, since no other case is to be found in the literature of the subject, but it is a proof that in the last stage of coal-tar distillation carbonic oxide plays a part. Mention must be made of the frequent occurrence of severe skin affections in _anthracene workers_; they take the form of an eruption on the hands, arms, feet, knees, &c., and sometimes develop into cancer. Observations in a chemical factory since 1892 showed that of thirty thus affected in the course of ten years twenty-two came into contact with paraffin. Artificial Organic Dye Stuffs (Coal-tar Colours) MANUFACTURE.—The starting-points for the preparation of artificial coal-tar dyes are mainly those aromatic compounds (hydrocarbons) described in the preceding section. Besides these, however, there are the derivatives of the fatty series such as methyl alcohol (wood spirit), ethyl alcohol, phosgene, and, latterly, formaldehyde. The _hydrocarbons of the benzene series_ from tar distillation are delivered almost pure to the colour factory. Of these benzene, toluene, xylene, naphthalene, anthracene, and the phenols, cresols, &c., have to be considered. Further treatment is as follows: 1. Nitration, i.e. introduction of a nitro-group by means of nitric acid. 2. Reduction of the nitrated products to amines. 3. Sulphonation, i.e. conversion to sulphonic acids by means of concentrated sulphuric acid. 4. The sulphonic acids are converted into phenols by fusing with caustic soda. 5. Introduction of chlorine and bromine. _Nitro-derivatives_ are technically obtained by the action of a mixture of nitric and concentrated sulphuric acids on the aromatic body in question. The most important example is _nitrobenzene_. Benzene is treated for several hours in cylindrical cast-iron pans with nitric and concentrated sulphuric acids. The vessel is cooled externally and well agitated. A temperature of 25° C. should not be exceeded. [Illustration: FIG. 25.—Preparation of Intermediate Products in the Aniline Colour Industry (Closed Apparatus), showing Arrangement for Condensation (_after Leymann_)] On standing the fluid separates into two layers: the lower consists of dilute sulphuric acid in which there is still some nitric acid, and the upper of nitrobenzene. The latter is freed of remains of acid by washing and of water by distillation. _Toluene_ and _xylene_ are nitrated in the same way. _Dinitro products_ (such as metadinitrobenzene) are obtained by further action of the nitro-sulphuric acid mixture on the mononitro-compound at higher temperature. For conversion of phenol into _picric acid_ (trinitrophenol) the use of a nitro-sulphuric acid mixture is necessary. The _aromatic bases_ (aniline, toluidine, xylidine) are obtained by reduction of the corresponding nitro-compound by means of iron filings and acid (hydrochloric, sulphuric, or acetic). Thus in the case of _aniline_ pure nitrobenzene is decomposed in an iron cylindrical apparatus, provided with agitators and a condenser, and avoidance of a too violent reaction, by means of fine iron filings and about 5 per cent. hydrochloric acid. After completion of the reaction the contents are rendered alkaline by addition of lime and the aniline distilled over. Manufacture of _toluidine_ and _xylidine_ is analogous. _Dimethylaniline_ is obtained by heating aniline, aniline hydrochloride, and methyl alcohol. _Diethylaniline_ is prepared in an analogous way with the use of ethyl alcohol. By the action of nitrous acid (sodium nitrite and hydrochloric acid) on the acid solution of the last-named compound the _nitroso compounds_ are formed. _Sulphonic acids_ arise by the action of concentrated or fuming sulphuric acid on the corresponding bodies of the aromatic series: benzene disulphonic acid from benzene and fuming sulphuric acid, &c. _Phenols_ and _cresols_ are obtained pure from tar distillation. The remaining hydroxyl derivatives (resorcin, α- and β-naphthol, &c.), are generally obtained by the action of concentrated caustic soda on aromatic sulphonic acids. The most important aromatic aldehyde, _benzaldehyde_, is obtained from toluene; on introducing chlorine at boiling temperature benzyl chloride is first formed, then benzal-chloride and finally benzo-trichloride. In heating benzal-chloride with milk of lime (under pressure) benzaldehyde is formed (C₆H₅COH). _Picric acid_ and _naphthol yellow_ belong to the _nitro dyestuffs_; the last named is obtained by sulphonating α-naphthol with fuming sulphuric acid and by the action of nitric acid on the sulphonated mixture. Nitroso derivatives of aromatic phenols yield (with metal oxides) the material for production of nitroso dyestuffs. To these belong naphthol green, &c. The most important _azo dyestuffs_ technically are produced in principle by the action of nitrous acid on the aromatic amines. The amido compound is converted into the diazo salt by treatment with sodium nitrite in acid solution. Thus diazo-benzene is made from aniline. Diazo compounds are not usually isolated but immediately coupled with other suitable compounds—amido derivatives, phenols—i.e. converted into azo compounds. [Illustration: FIG. 26.—Nitrating Plant (_after Leymann_) I Nitric acid II Balance III Storage tank IV Nitrating pan V Waste acid tank VI Acid egg VII Hydrocarbon VIII Balance IX Storage tank X Washing vessel XI Centrifugal machine XII Egg - - - Exhaust ventilation pipe.] The combination of the two constituents takes place at once and quantitatively. The colour is separated from the aqueous solution by salting-out, and is then put through a filter press. The reactions are carried out generally in wooden vats arranged in stages. Besides a second, a third constituent can be introduced, and in this way naphthol—and naphthylamine sulphonic acids yield a large number of colouring matters. A very large number of azo dyestuffs can thus be produced by the variation of the first component (the primary base) with the second and again with the third component, but it would carry us too far to deal further with their preparation. _Anthracene colours_—yielding so-called direct dyes—are prepared from anthracene, which is converted into anthraquinone by the action of bichromate and dilute sulphuric acid when heated; the crude ‘quinone’ is purified with concentrated sulphuric acid and converted into anthraquinone monosulphonic acid to serve in the preparation of _alizarin_, which is made from it by heating for several days with concentrated caustic soda to which sodium chlorate is added. The process is carried on in cast-iron pans provided with agitators. _Alizarin_ is the starting-point for the alizarin dyes, but of their production we will not speak further, as they, and indeed most of the coal-tar dyes, are non-poisonous. _Indigo_ to-day is generally obtained by synthesis. It is prepared from phenylglycine or phenylglycine ortho-carboxylic acid, which on heating with sodamide becomes converted into indoxyl or indoxyl carboxylic acid. These in presence of an alkali in watery solution and exposure to the oxygen of the air immediately form indigo. The necessary glycine derivatives are obtained by the action of monochloracetic acid on aniline or anthranilic acid, which again are derived from naphthalene (by oxidation to phthalic acid and treatment of phthalimide with bleaching powder and soda liquor). _Fuchsin_ belongs to the group of triphenylmethane dyestuffs, with the production of which the epoch of coal-tar colour manufacture began, from the observation that impure aniline on oxidation gave a red colour. The original method of manufacture with arsenic acid is practically given up in consequence of the unpleasant effects which use and recovery of large quantities of arsenic acid gave rise to. The method consisted in heating a mixture of aniline and toluidine with a solution of arsenic acid under agitation in cast-iron cylinders. The cooled and solidified mass from the retorts was boiled, and from the hot solution, after filtration, the raw fuchsin was precipitated with salt and purified by crystallisation. Now by the usual nitrobenzene process, aniline, toluidine, nitrobenzene, and nitrotoluene are heated with admixture of hydrochloric acid and some iron protochloride or zinc chloride. Further treatment resembles the arsenic process. By alkylation, i.e. substitution of several hydrogen atoms of the amido-groups by ethyl, &c., through the action of alkyl halogens and others, it was found possible to convert fuchsin into other triphenylmethane colours. But it was soon found simpler to transfer already alkylated amines into the colours in question. Thus, for example, to prepare _methyl violet_ dimethyl aniline was heated for a long time with salt, copper chloride, and phenol containing cresol in iron mixing drums. The product is freed from salt and phenol by water and calcium hydrate, subsequently treated with sulphuretted hydrogen or sodium sulphide, and the colour separated from copper sulphide by dissolving in dilute acid. Mention must be made, finally, of the _sulphur dyes_ obtained by heating organic compounds with sulphur or sodium sulphide. For the purpose derivatives of diphenylamine, nitro- and amido-phenols, &c., serve as the starting-point. EFFECTS ON HEALTH.—From what has been said of the manufacture of coal-tar dyes it is evident that poisoning can arise from the initial substances used (benzene, toluene, &c.), from the elements or compounds employed in carrying out the reactions (such as chlorine, nitric acid, sulphuric acid, arsenious acid, sodium sulphide, and sulphuretted hydrogen gas), from the intermediate bodies formed (nitro and amido compounds, such as nitrobenzene, dinitrobenzene, aniline, &c.), and that, finally, the end products (the dyes themselves) can act as poisons. It has already been said that most of the dyes are quite harmless unless contaminated with the poisonous substances used in their manufacture. We have seen that many of the raw substances used in the manufacture of coal-tar dyes are poisonous, and we shall learn that several of the intermediate products (especially the nitro and amido compounds) are so also. According to Grandhomme,[1] of the raw materials benzene is the one responsible for most poisoning. He describes two fatal cases of benzene poisoning. In one case the worker was employed for a short time in a room charged with benzene fumes, dashed suddenly out of it, and died shortly after. In the other, the workman was employed cleaning out a vessel in which lixiviation with benzene had taken place. Although the vessel had been steamed and properly cooled, so much benzene fume came off in emptying the residue as to overcome the workman and cause death in a short time. Grandhomme describes no injurious effect from naphthalene nor, indeed, from anthracene, which he considered was without effect on the workers. Similarly, his report as to nitrobenzene was favourable. No reported case of poisoning occurred among twenty-one men employed, in some of whom duration of employment was from ten to twenty years. Aniline poisoning, however, was frequent among them. In the three years there was a total of forty-two cases of anilism, involving 193 sick days—an average of fourteen cases a year and sixty-four sick days. None was fatal and some were quite transient attacks. In the fuchsin department no cases occurred, and any evil effects in the manufacture were attributable to arsenic in the now obsolete arsenic process. Nor was poisoning observed in the preparation of the dyes in the remaining departments—blues, dahlias, greens, resorcin, or eosin. In the manufacture of methylene blue Grandhomme points out the possibility of evolution of arseniuretted hydrogen gas from use of hydrochloric acid and zinc containing arsenic. Poisoning was absent also in the departments where alizarine colours and pharmaceutical preparations were made. Among the 2500-2700 workers Grandhomme records 122 cases of industrial sickness in the three years 1893-5, involving 724 sick days. In addition to forty-two cases of anilism there were seventy-six cases of lead poisoning with 533 sick days. Most of these were not lead burners, but workers newly employed in the nitrating department who neglected the prescribed precautionary measures. Lastly, he mentions the occurrence of chrome ulceration. The frequency of sickness in the Höchst factory in each of the years 1893-5 was remarkably high: 126 per cent., 91 per cent., and 95 per cent. Much less was the morbidity in the years 1899-1906—about 66 per cent.—recorded by Leymann[2]—probably the same Höchst factory with 2000 to 2200 employed. And the cases of industrial poisoning also were less. He cites only twenty-one in the whole of the period 1899-1906. Of these twelve were due to aniline, involving thirty sick days, only five to lead poisoning, with fifty-four sick days, one to chrome ulceration, one to arseniuretted hydrogen gas (nine sick days), and one fatal case each from sulphuretted hydrogen gas and from dimethyl sulphate. In 1899, of three slight cases of aniline poisoning one was attributable to paranitraniline (inhalation of dust), and the two others to spurting of aniline oil on to the clothing, which was not at once changed. Of the four cases in 1900, one was a plumber repairing pipes conveying aniline and the others persons whose clothes had been splashed. In 1903 a worker employed for eleven and a half years in the aniline department died of cancer of the bladder. Such cancerous tumours have for some years been not infrequently observed in aniline workers, and operations for their removal performed. Leymann thinks it very probable that the affection is set up, or its origin favoured, by aniline. This view must be accepted, and the disease regarded as of industrial origin. Three slight cases in 1904 and 1905 were due partly to contamination of clothing and partly to inhalation of fumes. Of the five cases of lead poisoning three were referable to previous lead employment. Perforation of the septum of the nose by bichromate dust was reported once only. A fatal case from sulphuretted hydrogen gas and a case of poisoning by arseniuretted hydrogen gas occurred in 1906, but their origin could not be traced. In large modern aniline dye factories, therefore, the health of the workers is, on the whole, good and industrial poisoning rare. Comparison of the two sets of statistics show that improvement in health has followed on improved methods of manufacture. Such cases of aniline poisoning as are reported are usually slight, and often accounted for by carelessness on the part of the workers. Data as to the health of workers in factories manufacturing or using nitro compounds are given in the English factory inspectors’ reports for 1905. Even with fortnightly medical examination in them, more than half the workers showed signs of anæmia and slight cyanosis. Two men in a factory employing twelve men in the manufacture of nitro compounds were treated in hospital for cyanosis, distress of breathing, and general weakness. One had only worked in the factory for nine days. In another badly ventilated factory, of twenty persons examined fourteen showed bluish-grey coloration of the lips and face, ten were distinctly anæmic, and six showed tremor and weakness of grasp. Nitrobenzene poisoning arises from the fumes present in aniline and roburite factories. Acute and chronic poisoning by nitro compounds of the benzene series are described, brought about by accident (fracture of transport vessels) and by carelessness (splashing on to clothes). Cases of optic neuritis (inflammation of the optic nerve) as a result of chronic nitrobenzene poisoning are described. Dinitrobenzene and other nitro and dinitro compounds are present in safety explosives. Thus roburite and bellite consist of metadinitrobenzene and ammonium nitrate; ammonite of nitronaphthalene and ammonium nitrate; securite of the materials in roburite with ammonium oxalate in addition. In roburite there may be also chlorinated nitro compounds. Leymann,[3] describing accidents in the preparation of nitrophenol and nitrochloro compounds, mentions four fatal cases occurring in the manufacture of black dyes from mono- and di-nitrophenols as well as mono- and di-nitrochlorobenzene and toluene. In three of the cases dinitrophenol was the compound at fault owing to insufficient care in the preparation,—the result of ignorance until then of risk of poisoning from mono- and tri-nitrophenol. One of the men had had to empty a washing trough containing moist dinitrophenol. He suddenly became collapsed, with pain in the chest, vomiting, fever, and convulsions, and died within five hours. Another suffered from great difficulty of breathing, fever, rapid pulse, dilatation of the pupils, and died within a few hours in convulsions. Two further cases of nitrochlorobenzene poisoning are referred to, one of which was fatal. Four chlorobenzene workers after a bout of drinking were found unconscious in the street, and only recovered after eight to ten hours in hospital. The symptoms were grey-blue colour of the skin, pallor of mucous membranes, lips, nose, and conjunctivæ, and peculiar chocolate-coloured blood. Many cases of poisoning from roburite are recorded.[4] In the Witten roburite factory it is stated that during the years 1890-7 almost all the workers had been ill.[5] Only three looked healthy—all the others suffered from more or less pallor, blue lips, and yellowish conjunctivæ. A case of chlorobenzene poisoning was reported with symptoms of headache, cyanosis, fainting attacks, difficulty of breathing, &c., in a man who had worked only three weeks with the substance.[6] In the nitrotoluene department of an explosives factory a number of the workmen suffered from symptoms of distress in breathing, headache, &c., of whom two, employed only a short time, died. The poisoning was attributed, partly to nitrotoluene and partly to nitrous fumes. As a contributing cause it was alleged that in view of shortage of hands unsuitable persons were engaged who neglected precautions.[7] Nitronaphthalene is said to cause inflammation and opacity of the cornea,[8] attributable either to long-continued exposure (four to eight months) to nitronaphthalene vapour or to spurting of the liquid into the eye. I could not find reference in literature to actual cases of poisoning by picric acid. They are referred to in a general way only as causing skin affections. Aniline poisoning arises generally from inhalation, but absorption through the skin and less frequently inhalation of dust of aniline compounds cause it. We have already laid stress on the frequently severe cases resulting from carelessness in spilling on to or splashing of, clothes without at once changing them, breaking of vessels containing it, and entering vessels filled with the vapour. In literature of old date many such cases have been described, and it was stated that workers were especially affected on hot days, when almost all showed cyanosis. Such observations do not state fairly the conditions to-day in view of the improvements which Grandhomme and Leymann’s observations show have taken place in aniline factories. Still, cases are fairly frequent. Thus in a factory with 251 persons employed, thirty-three cases involving 500 days of sickness were reported. The Report of the Union of Chemical Industry for 1907 cites the case of a worker who was tightening up the leaky wooden bung of a vessel containing aniline at a temperature of 200° C. He was splashed on the face and arms, and although the burns were not in themselves severe he died the next day from aniline absorption. Cases of anilism are not infrequent among dyers. The reports of the Swiss factory inspectors for 1905 describe a case where a workman worked for five hours in clothes on to which aniline had spurted when opening an iron drum. Similar cases are described in the report of the English factory inspectors for the same year. Aniline black dyeing frequently gives rise to poisoning, and to this Dearden[9] of Manchester especially has called attention. Typical aniline poisoning occurred in Bohemia in 1908 in a cloth presser working with black dyes. While crushing aniline hydrochloride with one hand, he ate his food with the other. That the health of persons employed in aniline black dyeing must be affected by their work is shown by medical examination. For instance, the English medical inspector of factories in the summer months of 1905 found among sixty persons employed in mixing, preparing, and ageing 47 per cent. with greyish coloration of lips and 57 per cent. characteristically anæmic. Further, of eighty-two persons employed in padding, washing, and drying, 34 per cent. had grey lips, 20 per cent. were anæmic, and 14 per cent. with signs of acute or old effects of chrome ulceration. Gastric symptoms were not infrequently complained of. The symptoms were worse in hot weather. Use of aniline in other industries may lead to poisoning. Thus in the extraction of foreign resins with aniline seventeen workers suffered (eleven severely). Interesting cases of poisoning in a laundry from use of a writing ink containing aniline have been recorded.[10] Reference is necessary to tumours of the bladder observed in aniline workers. The first observations on the subject were made by Rehn of Frankfurt, who operated in three cases. Bachfeld of Offenbach noticed in sixty-three cases of aniline poisoning bladder affections in sixteen. Seyberth described five cases of tumours of the bladder in workers with long duration of employment in aniline factories.[11] In the Höchst factory (and credit is due to the management for the step) every suspicious case is examined with the cystoscope. In 1904 this firm collected information from eighteen aniline factories which brought to light thirty-eight cases, of which eighteen ended fatally. Seventeen were operated on, and of these eleven were still alive although in three there had been recurrence. Tumours were found mostly in persons employed with aniline, naphthylamine, and their homologues, but seven were in men employed with benzidine. Cases of benzene and toluidine poisoning in persons superintending tanks and stills have been described. Industrial paranitraniline poisoning has been described, and a fatal case in the Höchst dye works was attributed by Lewin (as medical referee) to inhalation of dust. Before his death the workman had been engaged for five hours in hydro-extracting paranitraniline. Paraphenylene diamine leads not unfrequently to industrial poisoning from use of ursol as a dye. It produces skin eruptions and inflammation of the mucous membrane of the respiratory passages.[12] No doubt the intermediate body produced (diimine) acts as a powerful poison. A case of metaphenylene diamine poisoning is quoted in the Report of the Union of Chemical Industry for 1906. A worker had brought his coffee and bread, contrary to the rules, into the workroom and hidden them under a vessel containing the substance. Immediately after drinking his coffee he was seized with poisoning symptoms, and died a few days later. Some of the poison must have dropped into his coffee. Few instances of poisoning from pure aniline colours are recorded. At first all tar colours were looked upon as poisonous, but as they were mostly triphenylmethane colours they would contain arsenious acid. When the arsenic process was given up people fell into the other extreme of regarding not only the triphenylmethane colours but all others as non-poisonous, until experience showed that production and use of some of the tar colours might affect the skin. Finally, mention must be made of inflammation of the cornea caused by methyl violet dust. The basic aniline dyes are said to damage the eye. As opposed to this view is the fact that methyl violet and auramine are used as anti-bactericidal agents, for treatment of malignant tumours, and especially in ophthalmic practice. II. SMELTING OF METALS LEAD (ZINC, SILVER) OCCURRENCE OF INDUSTRIAL LEAD POISONING IN GENERAL _Chronic lead poisoning_ plays the most important rôle in industrial metallic poisoning, and indeed in industrial poisoning generally. The result everywhere where inquiry into industrial poisoning has been instituted has been to place the number of cases of lead poisoning at the top of the list; for one case of other forms of industrial poisoning there are twenty of lead. In the last few years a very extensive literature and one not easily to be surveyed has grown up on the subject of chronic industrial lead poisoning. I cannot attempt as I have done with other forms of poisoning to do justice to all sources of literature on this subject. As there is no obligation to notify industrial lead poisoning[B]—or indeed any form of industrial poisoning—in many countries, the most important source of information is wanting. Nevertheless more or less comprehensive inquiries as to the extent of the disease in general have been made in different countries and large cities which furnish valuable data. An idea of the yearly number of cases of lead poisoning occurring in Prussia is given in the following statistics of cases treated in Prussian hospitals for the years 1895-1901: +-------+--------+----------+--------+ \| Year. \| Males. \| Females. \| Total. \| +-------+--------+----------+--------+ \| 1895 \| 1120 \| 43 \| 1163 \| \| 1899 \| 1601 \| 23 \| 1624 \| \| 1900 \| 1509 \| 14 \| 1523 \| \| 1901 \| 1359 \| 24 \| 1383 \| +-------+--------+----------+--------+ The occupation of these cases was as follows: +-------+----------------+-------------+-----------+ \| Year. \| Metallic Lead. \| White Lead. \| Painters. \| +-------+----------------+-------------+-----------+ \| 1895 \| 364 \| 312 \| 347 \| \| 1899 \| 551 \| 310 \| 460 \| \| 1900 \| 516 \| 360 \| 378 \| \| 1901 \| 498 \| 282 \| 339 \| +-------+----------------+-------------+-----------+ About half the cases, therefore, are caused by use of white lead. The report of the sick insurance societies of the Berlin painters gives information as to the proportion treated in hospital to those treated at home, which was as 1:4. The industries may be classified according to risk as follows[1]: White lead workers, 33 per cent.; red lead workers, 32 per cent.; shot and lead pipe workers, 20 per cent.; painters, 7-10 per cent.; lead and zinc smelters, 8-9 per cent.; printers, 0·5 per cent. In Austria through the Labour Statistical Bureau comprehensive information is being collected as to the occurrence of lead poisoning in the most dangerous trades, but is not yet published. The reports of the factory inspectors give a very incomplete picture; for example, in 1905 only fifteen cases are referred to. In the most recent report (1909) information of lead poisoning is only given for thirty works. Teleky has made a general survey of the occurrence of lead poisoning from the reports of the Austrian sick insurance societies.[2] From this we gather that in Vienna, with an average membership of 200,000, there were, in the five year period 1902-6, 634, 656, 765, 718, 772 cases of illness involving incapacity from mineral poisons, which Teleky assumes were practically all cases of lead poisoning. By circularising Austrian sick insurance societies outside Vienna with a membership of about 400,000, Teleky obtained information of 189 cases, which he considers too few. In 1906-1908 inquiry was made by the sick insurance societies in Bohemia as to the extent of lead poisoning. With an average number employed of from 700,000 to 850,000 information was obtained of 91, 147, and 132 cases in the three years in question. The increase in 1907 was probably accounted for by the greater attention paid to the subject.[3] The number of ascertained cases of lead poisoning treated by the societies of Hungary was 225 in 1901 and 161 in 1902. Teleky again considers these figures too low, which is proved by Toth’s publications as to lead poisoning in Hungarian lead smelting works, and especially Chyzer’s on lead poisoning among Hungarian potters. Legge has reported fully in the second International Congress for Industrial Diseases in Brussels (September 1910) on occurrence of industrial lead poisoning in Great Britain in the years 1900 to 1909. During that period 6762 cases with 245 deaths occurred. The number of cases in the course of the ten years had diminished by 50 per cent. These figures appear remarkably small, but it has to be borne in mind that the statistics referred to related only to cases occurring in factories and workshops, and do not include cases among house painters and plumbers. The number of such cases which came to the knowledge of the Factory Department in 1909 was 241 (with 47 deaths) and 239 in 1908 (with 44 deaths). LEAD, SILVER, AND ZINC SMELTING _Lead_ is obtained almost entirely from galena by three different processes. In the _roast and reaction process_ galena is first roasted at 500°-600° C. and partially converted into lead oxide and lead sulphate: on shutting off the air supply and increase of temperature the sulphur of the undecomposed galena unites with the oxygen of the lead oxide and sulphate to form sulphur dioxide, while the reduced metallic lead is tapped. In the _roast and reduction_ process the ore is completely calcined so as to get rid of sulphur, arsenic, and antimony. The oxides (and sulphates) formed are reduced by means of coke in a blast furnace. This process is generally applicable and is, therefore, that most in use. The _precipitation_ process consists chiefly in melting galena with coke and iron flux, whereby the lead is partly freed from the sulphur, and, in addition to lead, iron sulphide is formed, which acts on the remaining lead sulphide, producing a lead matte which can be further treated. [Illustration: FIG. 27.—Smelting Furnace, showing mechanical charging and exhaust ventilation applied to slag runs, &c. (_Locke, Lancaster & W. W. & R. Johnson & Sons, Ltd. By permission of the Controller of H.M. Stationery Office._)] The roast and reaction process is carried out in specially constructed reverberatory furnaces; small furnaces with small amounts of ore and at as low a temperature as possible are the rule in the Kärntner process. In the English process large amounts of ore are melted in large furnaces at high temperatures so as to oxidise the material. The so-called Tarnowitz process combines these two—large amounts of ore are roasted in large furnaces at a moderate temperature. In the roast and reduction process it depends on the nature of the ore whether the roasting is done in reverberatory or blast furnaces. Generally the ore is in the form of powder—less often in pieces. Pyritic ore (ore with much sulphur) is almost always roasted in blast furnaces, and the sulphur dioxide evolved can be used in the manufacture of sulphuric acid. Open-hearth furnaces are rarely used now. Reverberatory furnaces are employed most frequently. The lead thus obtained contains several other metals, especially silver, copper, arsenic, antimony, iron, zinc, bismuth, and tin. Lead containing silver (work-lead) is next _de-silverised_, after which follows refining to get rid of the other impurities. For de-silverising work-lead rich in silver (containing about 10 per cent.) _cupellation_ is practised, in which the silver lead is melted and oxidised so that the lead is converted into _litharge_, metallic silver remaining behind. In a cupellation furnace the flame strikes on the top of the lead bath, and at the same time air under slight pressure is driven in; the litharge which forms is removed through suitable openings. The litharge that is first formed contains silver and is treated again; the remainder is ready for market. After the litharge has run off silver appears, containing still 5-10 per cent. of lead, and it is again submitted to an analogous refining process. Work-lead which does not contain enough silver to be cupelled at once is generally treated first by either the Pattinson or the Parkes’ process. In the _Pattinson_ crystallising process work-lead is melted in open semi-circular pots: as the pots cool crystals of lead poor in silver form on the surface and are transferred by a perforated ladle into the next pot: the silver collects in the small amount of molten lead remaining behind. Lead that has become enriched by repeated crystallisation contains a high percentage of silver and is cupelled. The _Parkes’_ process or _zinc de-silverisation_ depends on the formation of a lead-zinc alloy which is less fusible than lead. Work-lead is melted and agitated with addition of pure zinc. The crust which first rises on cooling contains gold, copper, zinc, and lead, and is removed. Further addition of zinc is then made: the rich silver crust which separates is subsequently freed from lead by gradual heating in a reverberatory furnace, and from zinc, in a zinc distilling retort. Other impurities are got rid of by oxidising in reverberatory or other furnaces. Small quantities of antimony and arsenic are removed by stirring with fresh green sticks. _Zinc_ is obtained principally from blende (sulphide of zinc) and from calamine (carbonate of zinc). The process of zinc recovery depends on the production of zinc oxide and reduction of this by carbon to metallic zinc. Conversion of the ore to zinc oxide is effected by roasting. Since the temperature at which reduction takes place is higher than the melting-point of zinc the latter is volatilised (distilled) and must be condensed in suitable condensers. Calamine is calcined in a blast furnace. Blende was formerly roasted in reverberatory furnaces, but such nuisance arose to the neighbourhood from sulphur dioxide vapour that now Hasenclever-Helbig calcining furnaces are used. These furnaces furnish a gas so rich in sulphur dioxide that they serve at once for the production of sulphuric acid. The Hasenclever furnaces consist of muffles placed one above another: the finely ground ore is charged through hoppers above and then raked down from muffle to muffle. Reduction is carried out in the Belgian or Silesian process by strongly heating calcined matte with coal in retorts. The zinc as it distils is caught in special condensing receptacles (prolongs). After distillation is complete the residue is raked out of the muffle and the furnace charged afresh. As zinc ores generally contain much lead, the work-zinc is therefore refined by remelting in a reverberatory furnace, during which process the impurities collect on the zinc as dross and are removed by agitation with sal-ammoniac or magnesium chloride. [Illustration: FIG. 28.—Arrangement of Spelter Furnace showing Ventilating Hood.] RISK OF POISONING IN LEAD, SILVER, AND ZINC SMELTING.—As the description of the manipulations in smelting processes shows, all involve risk of lead poisoning. As a matter of fact in lead smelting much lead passes into the atmosphere. In the smelting works at Tarnowitz yearly some 36,000 kilos of oxidised lead escape. Estimations[4] of the amount of lead in air samples collected in lead smelting works have been made. Thus in a cubic metre of air immediately over the slag run from 0·0029 to 0·0056 g. of lead were found, so that a worker in a ten-hour day would inhale from 0·013 to 0·025 g. of lead. In a cubic metre of air immediately above the Parkes’ melting-pot from 0·0056 to 0·0090 g. were found, so that a worker would inhale daily from 0·0252 to 0·0405 g. if he kept constantly close to the pot. On the handles of a de-silveriser 0·112 g. were found. In Hungarian lead-smelting works the water in which the hands had been washed was found to contain 1·27 g. of lead per litre. The hands of litharge grinders and sifters showed the highest amounts. Work carried on in lead-smelting works may be divided into five classes according to risk. Those most exposed to risk are the smelters at lead hearths and reverberatory furnaces, persons employed at the lead and slag runs, flue cleaners, and in crushing and packing flake litharge. Next come those employed at the refining furnaces, those breaking up the roasted ore, blast furnace workers, and those employed at the cupellation process. Attended with danger also is the removal of lead ashes and distillation of the zinc crust. Less dangerous are transport of material, crushing and mixing the ore, refining the work-lead and zinc crust, and work at the Pattinson and Parkes’ processes. In zinc smelting risk of lead poisoning is great, no matter which process is in question, because of the high proportion of lead in the ore and work-zinc. Swedish blende contains as much as 9 per cent. of lead, and Upper Silesian 2½ per cent. or less. There is risk in calcination, but it is much less than in the distillation process.[5] There are no quite satisfactory statistics as to the number of cases of lead poisoning in smelting works. Nevertheless, a number of recent publications give valuable data for certain smelting works in Germany, Austria, and Hungary. From details[6] of lead poisoning at Tarnowitz it would appear that the conditions have materially improved since 1884, the cases having declined from 32·7 per 100 employed in 1884 to 6·2 in 1894 and 1895. The following figures show the proportion affected in the different processes in the years 1901 and 1902: Process. Year. No. Employed. Cases. Per Cent. Reverberatory Furnace { 1901 131 11 8·3 { 1902 111 4 3·6 Blast Furnace { 1901 152 47 30·9 { 1902 187 21 11·1 Cupelling Furnace { 1901 12 1 8·3 { 1902 12 1 8·3 De-silverising { 1901 32 10 31·2 { 1902 34 7 20·6 Other Employment { 1901 300 7 2·3 { 1902 350 2 0·6 In one smelting works the percentage attack rate was 17·8 in 1901, and 27·1 in 1902. Here the number of workers had increased from 73 in 1901 to 129 in 1902, and the absolute and relative increase probably has relation to the well-known fact that newly employed untrained workers become affected. Similar incidence according to process can be given for the Friedrich’s smelting works during the years 1903-1905: Process. Year. No. Employed. Cases. Per Cent. Reverberatory Furnace { 1903 86 12 13·9 { 1904 87 8 9·2 { 1905 83 11 13·3 Blast Furnace { 1903 267 59 22·1 { 1904 232 24 10·3 { 1905 247 27 10·9 De-silverising { 1903 56 12 21·4 { 1904 73 4 5·5 { 1905 75 4 5·3 Cupelling { 1903 16 4 25·0 { 1904 15 1 6·7 { 1905 14 1 7·1 Other Employment { 1903 330 5 1·5 { 1904 309 4 1·3 { 1905 347 7 2·0 Among 3028 cases of lead poisoning treated between 1853 and 1882 in smelting works near Freiberg (Saxony) gastric symptoms were present in 1541, rheumatic pains in 215, cerebral symptoms in 144, paralysis in 58, and lead colic in 426. The recent reports of the German factory inspectors point still to rather high incidence in many lead smelting works. Thus in the district of Aix la Chapelle in 1909 there were sixty cases involving 1047 sick days, as compared with 58 and 878 in 1908. In a well-arranged smelting works near Wiesbaden fifty-two and forty-two cases were reported in 1908 and 1909 respectively, among about 400 persons employed. This relatively high number was believed to be closely connected with frequent change in the _personnel_. Introduction of the Huntingdon-Heberlein method is thought to have exercised an unfavourable influence. Other smelting works in Germany appear to have a relatively small number of reported cases. Thus in 1909 among 550 workers employed in four smelting works in the Hildesheim district only four cases were reported, and in the district of Potsdam among 600 smelters only five were found affected on medical examination. There is no doubt that many of the cases described as gastric catarrh are attributable to lead. Full information as to the conditions in Austria is contained in the publication of the Imperial Labour Statistical Bureau. In this comprehensive work the conditions in smelting works are described. In the lead smelting works at Przibram the cases had dropped from an average of 38·2 among the 4000-5000 persons employed to twenty-two in 1894 and to six in 1903, but only the severer cases are included. No single case has occurred among the 350-450 persons engaged in mining the ore, as galena (lead sulphide) is practically non-poisonous. It was found, for example, that 50 per cent. of the furnace men had (according to their statement) suffered from lead colic. Of eight employed in the Pattinson process, seven stated they had suffered from colic. The lead smelting works in Gailitz showed marked frequency of lead poisoning—here the appointed surgeon attributed anæmia and gastric and intestinal catarrh to lead: Illness of Saturnine Origin. Year. No. Lead Colic. Per Cent. Employed. Anæmia. Intestinal Catarrh. due to Gastric Total Lead Total Lead. Catarrh. Sickness. Sickness. 1899 61 14 2 76 16 108 178 60·0 1900 57 6 2 16 5 29 80 36·2 1901 48 4 2 17 1 24 60 40·0 1902 47 — — 24 6 30 56 53·5 1903 49 — 3 11 4 18 57 31·6 The diminution in the number of cases, especially of colic, is attributable to the efforts of the appointed surgeon. At Selmeczbanya a diminution from 196 cases in 1899 (50·7 per cent.) to six (2·2 per cent.) in 1905 had taken place. These figures point clearly to the success of the hygienic measures adopted in the last few years. In the large spelter works of Upper Silesia during the years 1896-1901, among 3780 persons employed, there were eighty-three cases of lead colic and paralysis, that is, about 2·2 per cent. each year. The following tables show the incidence among spelter workers in the works in question from 1902 to 1905: ILLNESS AMONG ZINC SMELTERS Lead Colic Year. and Kidney Gastric Anæmia. Rheumatism. No. Lead Paralysis. Disease. Catarrh. Employed. 1902 29 18 137 18 448 4417 1903 28 21 151 24 470 4578 1904 44 23 181 35 596 4677 1905 50 18 223 40 612 4789 Average 0·8% 0·5% 3·7% 0·6% 11·5% 4615 ILLNESS AMONG CALCINERS Lead Colic Year. and Kidney Gastric Anæmia. Rheumatism. No. Lead Paralysis. Disease. Catarrh. Employed. 1902 — — 5 1 78 1149 1903 — — 9 — 112 1087 1904 2 — 68 1 136 1140 1905 1 2 47 2 134 1159 Average 0·08% 0·05% 2·6% 0·1% 10·2% 1134 In thirty-two spelter works in the district of Oppeln in the year 1905, among 4789 spelter workers proper, there were 50 cases of colic, 18 of kidney disease, 223 of gastric and intestinal catarrh, 40 of anæmia, and 612 of rheumatism, and among 1159 calciners 1 case of colic, 2 of kidney disease, 47 of gastric catarrh, 2 of anæmia, and 134 of rheumatism. Cases are much more numerous in spelter works where Swedish blende containing lead is worked. It is remarkable, however, that in large spelter works in Upper Silesia, where for years no cases of lead poisoning were reported, medical examination showed that 20·5 per cent. had signs of lead absorption. White Lead and Lead Colours MANUFACTURE.—The primitive Dutch process consisted in placing lead grids in earthenware pots containing dilute acetic acid and covering them with tan bark. Fermentation ensued with evolution of carbonic acid gas and increase in temperature. The acetic acid vapour forms, with aid of atmospheric oxygen, first basic lead acetate, which, by the action of the carbonic acid gas, becomes converted into white lead and neutral lead acetate. The product is crushed, sieved, and dried. In the German or Austrian process thin sheets of metallic lead are hung saddle-wise in chambers. Acetic acid vapour and carbonic acid gas (produced by burning coke) are led in from below. The chamber is then sealed and kept so for a considerable time. When the chamber is ‘ripe’ the white lead that has formed is taken out, freed from uncorroded lead by spraying, dried, finely ground, and packed. White lead comes on the market either as a powder or incorporated with oil. Of the remaining lead colours, red lead (Pb₃O₄) is much used. It is produced by heating lead oxide in reverberatory furnaces with access of air and stirring. Lead Poisoning in the Manufacture of White Lead and Lead Colours The manufacture by the German process may be divided into three categories according to the degree of risk run: 1. The most dangerous processes are hanging the plates in the chambers, work at the filter press, drying, pulverising, and packing by hand. 2. Less dangerous are transport to the washer, washing, and grinding. 3. Relatively the least dangerous are casting the plates, transport of them to the chambers, drying, mechanical packing, and mixing with oil. The number of cases of lead poisoning in white lead factories is often relatively great despite regulations. Casual labourers especially run the greatest risk. This is frequently brought out in the reports of the German factory inspectors, who connect the high proportion of cases directly with the large number of unskilled workers. Regulations are really only successful in factories with regular employment. This has been found also in Great Britain, where the Medical Inspector of Factories showed that the cases among regular workers numbered 6 per cent. and among casual workers 39 per cent. The following table gives particulars as to the occurrence of lead poisoning in the white lead factories in the district of Cologne in 1904, some of which have admirable hygienic arrangements: +-----------+--------------+-----------------+---------------+--------+ \| \| \| No. Employed. \|Cases of Lead \| \| \| \| \| \|Poisoning. \| \| \| \| +-----------------+---------------+ No. of \| \| Place. \| Manufacture. \|Regular \|Regular \|Cases of\| \| \| \| \|Casual \| \|Casual \|Gastric \| \| \| \| \| \|Average \| \|Total\|Catarrh.\| +-----------+--------------+-----+-----+-----+----+----+-----+--------+ \|Cologne I. \| White lead {\| 46 \| 59 \| 32 \| 9 \| 16 \| 25 \| 16 \| \| \| {\| 173 \| 95 \| 127 \| 13 \| 17 \| 30 \| 22 \| \| ” I. \| Litharge and{\| 46 \| 4 \| 38 \| 5 \| 1 \| 6 \| 7 \| \| \| red lead {\| 76 \| 62 \| 49 \| 3 \| 4 \| 7 \| 15 \| \| \| Chromate {\| 14 \| 2 \| 11 \| — \| — \| — \| 5 \| \| \| {\| 43 \| 72 \| 33 \| — \| — \| — \| 7 \| \|Cologne II.\| White lead, {\| \| \| \| \| \| \| \| \| \| litharge, {\| 107 \| 332 \| 91 \| 6 \| 34 \| 40 \| 30 \| \| \| and red lead{\| 102 \| 332 \| 76 \| 9 \| 19 \| 28 \| 38 \| +-----------+--------------+-----+-----+-----+----+----+-----+--------+ It is worth noting that cases of lead poisoning have been reported in the manufacture of zinc white, as, for example, in Bohemia in 1907 and 1908. USE OF LEAD COLOURS AND PAINTS (HOUSE PAINTERS, DECORATORS, ETC.) Use of lead colours, especially by painters and decorators, causes relatively much lead poisoning. Apart from ignorance of danger on the part of the worker, and lack of personal cleanliness, unsuitable methods of working add to the danger, especially dry rubbing of painted surfaces, which gives rise to much dust containing lead. Again, the crushing and mixing of lumps of white lead and rubbing lead colours with the hand are very dangerous. The following German and Austrian figures enable conclusions to be drawn as to the frequency of lead poisoning among painters. In the sick insurance societies of Frankfurt-a-M. in 1903 of every 100 painters 11·6 suffered from an attack of lead poisoning. The similar sick insurance society of painters in Berlin has kept useful statistics which are given in the following table for the ten years 1900-9: +--------+----------+------------+--------------+ \| \| \| No. \| \| \| \| No. of \| of Cases \| Cases per \| \| Year. \| Members. \| of Lead \| 100 Members. \| \| \| \| Poisoning. \| \| +--------+----------+------------+--------------+ \| 1900 \| 3889 \| 357 \| 9·18 \| \| 1901 \| 3616 \| 335 \| 9·26 \| \| 1902 \| 3815 \| 308 \| 8·07 \| \| 1903 \| 4397 \| 470 \| 10·69 \| \| 1904 \| 5029 \| 516 \| 10·26 \| \| 1905 \| 5328 \| 471 \| 8·84 \| \| 1906 \| 5355 \| 347 \| 6·48 \| \| 1907 \| 5173 \| 379 \| 7·32 \| \| 1908 \| 4992 \| 298 \| 5·97 \| \| 1909 \| 4781 \| 285 \| 5·96 \| +--------+----------+------------+--------------+ \|Average \| 4637 \| 376·6 \| 8·11 \| +--------+----------+------------+--------------+ This shows that lead poisoning among the painters of Berlin is happily diminishing, which may be attributed to recent regulations. The society, however, complains in its reports that not all cases of lead appear as such in their statistics, and believes that all diseases entered as rheumatism, gastric catarrh, nervous complaints, heart and kidney disease, should be regarded as associated with lead. The kinds of work in which painters suffer most are painting iron girders and machines, sheet metal and iron furniture, railway waggons, agricultural implements, coach painting, cabinet-making, shipbuilding, and the use of red and white lead. The use of lead colours, _lead acetate_, and _lead chromate_ often give rise to lead poisoning. Colours containing lead are not infrequently used in the textile industry in dyeing, printing, and finishing. White lead has been used for weighting the weft. Teleky has described cases of lead poisoning in which _silk thread_ was weighted with acetate of lead. As a consequence a number of women engaged in sewing on fringes with the thread suffered. The English factory inspectors’ reports describe cases from manipulating _yarn dyed with chromate of lead_.[7] _Chromate of lead_ and _white lead_ are used in colouring oil-cloth, artificial flowers, paper, rubber goods, pencils, penholders, socks, sealing-wax, candles, and stamps. USE OF LEAD IN THE CHEMICAL INDUSTRY Lead poisoning has been frequently observed in such branches of the chemical industry as require large leaden or lead-lined vessels and pipes: the persons affected are principally those engaged in lead burning. Risk is considerable in manufacture of lead acetate. The most dangerous processes are drying and packing the crystals. MANUFACTURE OF ELECTRIC ACCUMULATORS The manufacture of accumulators begins with the casting of lead plates, which are then polished and dressed. Next follows ‘pasting,’ that is, smearing the negative plate with a paste of litharge, the positive plate being ‘formed’ by having an electric current passed through so that the lead is converted into spongy peroxide. The wooden boxes in which the plates are assembled are lead-lined. The most dangerous processes are casting, wire-brushing, and pasting—the latter especially when done by hand. In the years 1908 and 1909 among about 761 workers employed in the accumulator factories of Cologne there were fifty-six cases of lead colic and seventy-nine of gastric and intestinal catarrh. Further figures for German accumulator works show that in the two largest accumulator factories in the district of Potsdam employing 142 workers there were fifteen cases in 1904. In Great Britain, in the ten years 1900-1909, 285 cases were reported—an average of about thirty a year. THE CERAMIC INDUSTRY Risk is present in several branches of the ceramic industry. It is greatest in glazing earthenware, but not infrequent also in the porcelain and glass industries. It is impossible to deal with the extensive literature on this subject exhaustively. A comprehensive and detailed survey of lead poisoning in the ceramic industry on the Continent is that by Kaup. Distinction is made between leadless glazes which melt at high temperature and lead glazes which have the advantage of a low melting-point. Galena and litharge are used in the preparation of glazes for common earthenware and red and white lead for ware of better quality. Distinction has to be made between a lead silicious glaze for pottery ware, a lead and boric acid glaze for stoneware, and a lead and zinc oxide glaze for ordinary faience and stoneware. Seegar, the celebrated expert, praises the advantage of lead glaze and the use of lead in the ceramic industry—it is indeed practically indispensable—and speaks of the poisonous nature of lead as its only fault. The components of the glaze must have definite relation to the hardness or softness of the body. The higher the proportion of silicic acid in the glaze the harder the firing it will stand; the more the flux materials are in excess the lower will the melting point be. The most important flux materials are, arranged in order of decreasing fusibility, lead oxide, baryta, potash, soda, zinc oxide, chalk, magnesia, and clay. The _glaze_ is made by first mixing the ingredients dry, and then either fritting them by fluxing in a reverberatory furnace and finally grinding them very finely in water or using the raw material direct. In the fritting process in the case of the lead glazes the soluble lead compounds become converted into less soluble lead silicates and double silicates. The glaze is applied in different ways—dipping, pouring, dusting, blowing, and volatilising. Air-dried and biscuited objects are dipped; pouring the glaze on is practised in coarse ware, roofing-tiles, &c.; dusting (with dry finely ground glaze, litharge, or red lead) also in common ware; glaze-blowing (aerographing) and glaze dusting on porcelain. In these processes machines can be used. Bricks are only occasionally glazed with glazes of felspar, kaolin, and quartz, to which lead oxide is often added in very large quantity. Lead poisoning in _brick works_ in view of the infrequent use of lead is not common, but when lead is used cases are frequent. Kaup quotes several cases from the factory inspectors’ reports: thus in three roof-tiling works examination by the district physician showed that almost all the workers were affected. _Coarse ware pottery_ is made of pervious non-transparent clay with earthy fracture—only a portion of this class of ware (stoneware) is made of raw materials which fire white. Such ware generally receives a colourless glaze. The clay is shaped on the potter’s wheel, and is then fired once or, in the better qualities, twice. Grinding the ingredients of the glaze is still often done in primitive fashion in mortars. The glaze is usually composed of lead oxide and sand, often with addition of other lead compounds as, for example, in quite common ware, of equal parts of litharge, clay, and coarse sand. Sometimes, instead of litharge, galena (lead sulphide) or, with better qualities of ware, red lead or ‘lead ashes’ are used. The grinding of the glazes in open mills or even in mortars constitutes a great danger which can be prevented almost entirely by grinding in ball mills. The glaze material is next mixed with water, and the articles are either dipped into the creamy mass or this is poured over them. In doing this the hands, clothes, and floors are splashed. The more dangerous dusting-on of glaze is rarely practised. Occasionally mechanical appliances take the place of hand dipping. Placing the ware in the glost oven is done without placing it first in saggars. In the better qualities of pottery cooking utensils, which are fired twice, a less fusible fritted lead glaze is generally used. Coloured glaze contains, besides the colouring metallic oxides, 30-40 per cent. of litharge or red lead. As Kaup shows, Continental factory inspectors’ reports make only isolated references to occurrence of lead poisoning in potteries. Insight into the conditions in small potteries is obtained only from the Bavarian reports. In Upper Bavaria ninety-three potteries employ 157 persons who come into contact with lead glaze. Eleven cases were known to have occurred in the last four years. Teleky found thirty-six cases of lead poisoning (mostly among glostplacers) in the records of the Potters’ Sick Insurance Society of Vienna. Chyzer has described the striking conditions in Hungary. There there are about 4000 potters, of whom 500 come into contact with lead glaze. Chronic lead poisoning is rife among those carrying on the occupation as a home industry. Members of the family contract the disease from the dust in the living rooms. This dust was found to contain from 0·5 to 8·7 per cent. of lead. In the china and earthenware factories in Great Britain, in the ten years 1900-9, 1065 cases with fifty-seven deaths were reported. _Manufacture of stove tiles._—The application of glaze to stove tiles is done in different ways. The two most important kinds are (1) fired tiles and (2) slipped tiles. In the production of fired tiles a lead-tin alloy consisting of 100 parts lead and 30-36 parts tin—so-called ‘calcine’—are melted together in fireclay reverberatory or muffle furnaces and raked about when at a dull red heat so as to effect complete oxidation. The material when cool is mixed with the same quantity of sand and some salt, melted in the frit kiln, subsequently crushed, ground, mixed with water, and applied to the previously fired tiles. In this process risk is considerable. Presence of lead in the air has been demonstrated even in well-appointed ‘calcine’ rooms. In unsuitably arranged rooms it was estimated that in a twelve-hour day a worker would inhale 0·6 gramme of lead oxide and that 3-8 grammes would collect on the clothes. _Slipped tiles_ are made in Meissen, Silesia, Bavaria, and Austria by first applying to them a mixture of clay and china clay. The glaze applied is very rich in lead, containing 50-60 parts of red lead or litharge. Generally the glaze is applied direct to the unfired tiles and fired once. Figures as to occurrence of poisoning in Germany are quoted by Kaup from the towns of Velten and Meissen. Among from 1748 to 2500 persons employed thirty-four cases were reported in the five years 1901-5. Thirteen cases were reported as occurring in the three largest factories in Meissen in 1906. From other districts similar occurrence of poisoning is reported. In Bohemia in a single factory in 1906 there were fourteen cases with one death, in another in 1907 there were fourteen, and in 1908 twelve cases; eight further cases occurred among majolica painters in 1908. _Stoneware and porcelain._—Hard stoneware on a base of clay, limestone, and felspar has usually a transparent lead glaze of double earth silicates of lead and alkalis, with generally boric acid to lower the fusing-point; the lead is nearly always added in the form of red lead or litharge. The portion of the glaze soluble in water is fritted, and forms, when mixed with the insoluble portion, the glaze ready for use. The frit according to Kaup contains from 16 to 18 per cent. of red lead, and the added material (the mill mixing) 8-26 parts of white lead; the glaze contains from 13 to 28 parts of lead oxide. The ware is dipped or the glaze is sometimes aerographed on. Ware-cleaning by hand (smoothing or levelling the surface with brushes, knives, &c.) is very dangerous work unless carried out under an efficient exhaust. Colouring the body itself is done with coloured metal oxides or by applying clay (slipping) or by the direct application of colours either under or over the glaze. Some of the under-glaze colours (by addition of chrome yellow or nitrate of lead or red lead) contain lead and are applied with the brush or aerograph or in the form of transfers. _Plain earthenware_ is either not glazed or salt glazed; only when decorated does it sometimes receive an acid lead glaze. _Porcelain_ receives a leadless glaze of difficultly fusible silicate (quartz sand, china clay, felspar). Risk is here confined to painting with lead fluxes (enamel colours) containing lead. These fluxes are readily fusible glasses made of silicic acid, boric acid, lead oxide, and alkalis, and contain much lead (60-80 per cent. of red lead). In the _glass industry_ lead poisoning may occur from use of red lead as one of the essential ingredients. In Great Britain, in the years 1900-9, forty-eight cases were reported in glass polishing from use of putty powder. LETTERPRESS PRINTING, ETC. Type metal consists of about 67 per cent. lead, 27 per cent. antimony, and 6 per cent. tin, but sometimes of 75 per cent. lead, 23 per cent. antimony, and 2 per cent. tin. The actual printer comes least of all in contact with lead. Use of lead colours (white lead, chromate of lead, &c.) may be a source of danger, especially in the preparation of printing inks from them and in cleaning the printing rolls. A further, if slight, danger arises from the use of bronze powder consisting of copper, zinc, and tin. The two last-named metals contain from 0·1 to 0·5 per cent. of lead, and in the application and brushing off of the bronze there is a slight risk. The compositor is exposed to constant danger from handling the type and disturbing the dust in the cases. This dust may contain from 15 to 38 per cent. of lead. Blowing the dust out of the cases with bellows is especially dangerous, and want of cleanliness (eating and smoking in the workroom) contributes to the risk. Type founders and persons engaged in rubbing and preparing the type suffer. Introduction of type-casting machines (linotype, monotype) has lessened the danger considerably. No lead fumes are developed, as a temperature sufficiently high to produce them is never reached. In all the processes, therefore, it is lead dust which has to be considered. The following figures of the Imperial Statistical Office as to occurrence of lead poisoning among printers in Vienna indicate the relative danger: +---------------------------+-----------+-----------+----------+ \|Occupation. \|Average No.\|Average No.\|Percentage\| \| \|of Members,\| of Cases, \| of Cases,\| \| \|1901-1906. \|1901-1906. \|1901-1906.\| +---------------------------+-----------+-----------+----------+ \|Compositors \| 3182 \| 90·3 \| 2·8 \| \|Printers \| 809 \| 20·3 \| 2·4 \| \|Casters and Stereotypers \| 241 \| 15·8 \| 6·6 \| \|Females employed in casting\| 74 \| 8·17 \| 10·8 \| +---------------------------+-----------+-----------+----------+ In Bohemia there is reference to thirty-eight cases in letterpress printing in 1907 and twenty-seven in 1908. Among 5693 persons treated for lead poisoning between the years 1898 and 1901 in hospitals in Prussia, 222 were letterpress printers. Between 1900 and 1909 in Great Britain 200 cases of lead poisoning were reported. VARIOUS BRANCHES OF INDUSTRY The number of industries using lead is very large. Layet as long ago as 1876 enumerated 111. We, however, limit ourselves to those in which the risk is considerable. Use of _lead beds_ in _file-cutting_ has given rise to many cases. Further, to harden the file it is dipped into a bath of molten lead. From 3 to 6 per cent. of lead has been found in the dust in rooms where hardening is done. Of 7000 persons employed in file-cutting in the German Empire in the years 1901-5 on an average 30·5 or 0·43 per cent. were affected yearly. In Great Britain 211 cases were reported in the years 1900-9. In _polishing precious stones_ formerly many cases of lead poisoning occurred, the reason being that the polishers come into contact with particles of lead and fix the diamonds to be polished in a vice composed of an alloy of lead and tin. Danger is increased when the stones are actually polished on revolving leaden discs. In Bohemia granite polishing used to be done in this way, but is now replaced in many factories by carborundum (silicon carbide). Musical instrument making in Bohemia in the years 1906-8 was found regularly to give rise to cases of lead poisoning from use of molten lead in filling them with a view to shaping and bending. In lead pipe and organ pipe works, lead burning, plumbing, &c., considerable risk is run. Often the causes of lead poisoning are difficult to discover, and, when found, surprising. Thus shoemakers have suffered from holding leaden nails in the mouth. Again, cases in women have been reported from cutting out artificial flowers or paper articles with aid of lead patterns, or counting stamps printed in lead colours.[8] MERCURY As metallic mercury gives off vapour even at ordinary temperatures, poisoning can occur not only in the recovery of the metal from the ore, but also in all processes in which it is used. Chronic industrial poisoning occurs principally in the preparation and use of mercury salts, in recovery of the metal itself and of other metals with use of an amalgam, in water gilding, from use of nitrate of mercury in the preparation of rabbit fur for felt hat making, from use of mercury pumps in producing the vacuum in electric filament lamps, and in making barometers and thermometers. PREPARATION.—Mercury is obtained by roasting cinnabar (sulphide of mercury). When cinnabar is heated with access of air the sulphide burns to sulphur dioxide and the mercury volatilises and is subsequently condensed. Formerly the process was carried on in open hearths; now it is done usually in blast furnaces. The mercury is condensed in Idria in large chambers cooled with water, while at Almaden in Spain it is collected in a series of small earthenware receptacles (aludels), from small openings in which the mercury flows in gutters and collects. The mercury so recovered is usually redistilled. On the walls of the condensers a deposit of sulphide and oxide of mercury collects, removal of which is one of the operations most attended with risk. Recovery of silver or gold by amalgamation with mercury is carried on only in America. The metallic silver or gold is taken up by the mercury, from which it is recovered by distillation. The conditions in the quicksilver mines of Idria in Austria have improved of late years. Thus in the five years prior to 1886 of 500 cases of illness more than 11 per cent. were due to chronic mercurial poisoning. In 1906, 209 persons were employed, of whom only one-third were permanent hands. Among these the sickness rate was very high (95-104 per cent.). Of 741 cases of illness among the miners there were six of mercury poisoning, and of 179 among persons employed in recovery of the metal, twelve cases.[1] The conditions of employment in the cinnabar mines of Monte Amiata in Italy have recently been described in detail.[2] Here, although the recovery of the metal is carried out in modern furnaces, thus greatly reducing the danger, nevertheless nearly all the furnace workers suffer from chronic poisoning. In _silvering of mirrors_ the leaf of tinfoil was spread out on an inclined table; mercury was poured over it and the sheet of glass laid on the top with weights. The superfluous mercury was squeezed out and ran away owing to the sloping position of the table. Now this process, even in Fürth, is almost entirely replaced by the nitrate of silver and ammonia process. Years ago the number of cases of poisoning was very serious in places where, as in Fürth, the work was carried on as a home industry. In the production of _incandescent electric bulbs_ danger arises from breaking of the glass pipes of the pumps and scattering of mercury on the floor of the workrooms. Since there is a growing tendency to replace mercury pumps by air pumps such cases ought to become rare. In _water gilding_—a process little employed now—the metal objects (military buttons, &c.) to be gilded, after treatment with a flux, are brushed over with the mercury amalgam, and subsequently fired to drive off the mercury. Unless careful provision is made to carry away the vapour chronic poisoning cannot fail to occur. Even sweeps have been affected after cleaning the chimneys of water gilders’ workshops. In Great Britain, between 1899 and 1905, six cases were reported among water gilders. In the _manufacture of barometers_ and thermometers mercury poisoning is not infrequent. Between 1899 and 1905 sixteen such cases were reported in England; during the same period there were seventeen cases among those putting together electrical meters. Risk of mercurial poisoning is constantly present in _hatters’ furriers’ processes_ and in subsequent processes in felt hat factories. The risk from use of nitrate of mercury is considerable to those brushing the rabbit skins with the solution (carotting), and subsequently drying, brushing, cutting, locking, and packing them. According to Hencke in 100 kilos of the carotting liquid there are 20 kilos of mercury. In England, in the years 1899-1905, thirteen cases of mercurial poisoning were reported in hatters’ furriers’ processes. Among eighty-one persons so employed the medical inspector found twenty-seven with very defective teeth as the result of the employment, and seventeen with marked tremor. In the _manufacture of mercurial salts_ poisoning occurs chiefly when they are made by sublimation, as in the manufacture of vermilion, of corrosive sublimate (when mercurous sulphate is sublimed with salt), and in the preparation of calomel (when sublimate ground with mercury or mercurous sulphate mixed with mercury and salt is sublimed). Between 1899 and 1905 in England seven cases were reported from chemical works. As to occurrence of mercury poisoning from _fulminate of mercury_, see the chapter on Explosives. ARSENIC Chronic industrial _arsenical poisoning_, both as to origin and course, is markedly different from the acute form. The chronic form arises mainly from inhalation of minute quantities of metallic arsenic or its compounds in recovery from the ore, or from the use of arsenic compounds in the manufacture of colours, in tanyards, and in glass making. Acute industrial _arseniuretted hydrogen poisoning_ is especially likely to occur where metals and acids react on one another and either the metal or the acid contains arsenic in appreciable amount. Further, arseniuretted hydrogen may be contained in gases given off in smelting operations and in chemical processes. RECOVERY OF ARSENIC AND WHITE ARSENIC.—Pure arsenic is obtained from native cobalt and arsenical pyrites by volatilisation on roasting the ore in the absence of air. After the furnace has been charged sheet iron condensing tubes are affixed to the mouths of the retorts, which project out of the furnace, and to these again iron or earthenware prolongs. Arsenic condenses on the sides of the sheet metal tubes and amorphous arsenic, oxides, and sulphides in the prolongs. After sublimation has been completed the contents of the prolongs are removed and used for production of other arsenic compounds; the (generally) argentiferous residues in the retorts are removed and further treated in silver smelting works; finally, the crusts of crystalline arsenic (artificial fly powder) are knocked out from the carefully unrolled sheet iron tubes. As can be readily understood from the description opportunity of poisoning from volatilisation of arsenic and of arsenic compounds is considerable. Metallic arsenic is used for making hard shot, and for increasing the brilliancy and hardness of metal alloys (type metal, &c.). _White arsenic_ (arsenic trioxide) is obtained by roasting with access of air in reverberatory furnaces arsenical ores and smelting residues. The vapours of white arsenic sublime and are condensed as a powder in long walled channels or in chambers, and are resublimed in iron cylinders. White arsenic is used in making colours, in glass (for decolourising purposes), as an insecticide in the stuffing of animals, &c. INDUSTRIAL ARSENIC POISONING.—In the _extraction of arsenic_ and preparation of arsenious acid danger is present. But reliable accounts in literature of poisoning among those engaged in arsenic works are wanting. Those engaged in roasting operations and packing suffer much from skin affections. Similar poisoning is reported in the smelting of other arsenical ores—nickel, cobalt, lead, copper, iron, and silver, from arsenic compounds present in the fumes. This is especially the case in the smelting of tin, which generally contains arsenical pyrites. Danger is present also in _unhairing_ (i.e. removing the wool from sheep skins), since the skins imported from Buenos Aires and Monte Video are treated with a preservative which, in addition to sodium nitrate, soda, and potash, contains generally arsenious acid. In _tanneries_ a mixture of arsenic sulphide (realgar) and lime is used for unhairing. Arsenic is used also for preserving and stuffing animal furs; but although affections of the skin are described I cannot find reference to arsenical poisoning. The inspector for East London in 1905 refers to severe eczematous eruptions on face, neck, and hands, affecting workers in a _sheep dip_ works—mainly in the packing of the light powder in packets. Formerly the use of arsenic in the manufacture of colours was great, especially of _emerald (Schweinfurter) green_. This is made by dissolving arsenious acid in potash with addition of acetate of copper. Drying and grinding the material constitute the main danger. Scheele’s green is another arsenical colour. Use of _arsenic colours_ is becoming less and less. But in colour printing of paper and colouring of chalk they are still employed. They are used, too, as mordants in dyeing, but cases of poisoning from these sources in recent years are not to be found. The dust in many glass works contains, it is stated, as much as 1·5 per cent of white arsenic. Despite the numerous opportunities for arsenical poisoning in industries it is rare or, at any rate, is only rarely reported. ARSENIURETTED HYDROGEN POISONING.—Industrial poisoning from arseniuretted hydrogen is caused mostly by inhalation of the gases developed by the action on one another of acids and metals which contain arsenic. Hydrogen gas as usually prepared for filling balloons gives occasion for poisoning. In Breslau in 1902 five workmen became affected, of whom three died from inhalation of arseniuretted hydrogen gas in filling toy balloons.[1] Further, use of hydrogen in lead burning may expose to risk, and also preparation of zinc chloride flux. Of thirty-nine recorded cases of arseniuretted hydrogen poisoning twelve were chemists, eleven workers filling toy balloons, seven aniline workers, five lead smelters, three balloonists, and in one the origin could not be traced. Nineteen of these proved fatal within from three to twenty-four days.[2] Cases are recorded (1) in the reduction of nitroso-methylaniline with zinc and hydrochloric acid; (2) in the preparation of zinc chloride from zinc ashes and hydrochloric acid; (3) from manufacture of zinc sulphate from crude sulphuric acid and zinc dust; (4) in spelter works in the refining of silver from the zinc crust with impure hydrochloric acid; and (5) in the formation room of accumulator factories. The English factory inspectors’ report describes in 1906 occurrence of three cases in an electrolytic process for the recovery of copper in which the copper dissolved in sulphuric acid was deposited at the cathode, and hydrogen at the lead anode. In the 1907 report mention is made of two cases, one affecting a chemist separating bismuth from a solution of bismuth chloride in hydrochloric acid, and the other (which proved fatal) a man who had cleaned a vitriol tank. The poisoning resulting from ferro-silicon is in part referable to development of arseniuretted hydrogen gas. ANTIMONY It seems doubtful if industrial poisoning can really be traced to antimony or its compounds; generally the arsenic present with the antimony is at fault. Erben[1] considers that industrial antimony poisoning occurs among workmen employed in smelting antimony alloys in making tartar emetic through inhalation of fumes of oxide of antimony. A case is cited of a workman in Hamburg engaged in pulverising pure antimony who was attacked with vomiting which lasted for several days, and the inspector of factories noted epistaxis (nose bleeding) and vomiting as following on the crushing of antimony ore. Compositors in addition to chronic lead poisoning may suffer, it is alleged, from chronic antimony poisoning, showing itself in diminution in the number of white blood corpuscles and marked eosinophilia. These changes in the blood could be brought about experimentally in rabbits. Antimony was found by the Marsh test in the stools of those affected. IRON _Pig iron_ is obtained by smelting iron ores in blast furnaces (fig. 29), through the upper opening of which charges of ore, limestone or similar material to act as a flux, and coke are fed in succession. The furnaces are worked continuously, using a blast of heated air; carbon monoxide is produced and effects the reduction of the ore to molten iron. The latter accumulates in the hearth and is covered with molten slag; this flows constantly away through an opening and is collected in slag bogies for removal, or is sometimes cooled in water. The crude iron is tapped from time to time, and is led in a fluid condition into moulds called ‘pigs,’ in which it solidifies. Cast iron is occasionally used direct from the blast furnace for the purpose of making rough castings, but generally it is further refined before being used in a foundry by remelting with cast iron scrap in a cupola furnace. [Illustration: FIG. 29. _a_ Hearth; _b_ Bosh; _c_ Shaft; _d_ Gas uptake; _e_ Down-comer; _f_ Tuyères with water cooling arrangement; _g_ Blast pipes; _h_ Tapping hole; _k_ Supporting columns; _l_ Furnace bottom; _m_ Charging hopper; _n_ Bell with raising and lowering arrangement.] _Wrought iron_ is made by treating pig iron in refinery and puddling furnaces; in these much of the carbon is removed as carbon monoxide, and from the puddling furnace the iron is obtained as a pasty mass which can be worked into bars, rods, or plates. _Steel_ is made in various ways. The Acid Bessemer process consists in forcing compressed air in numerous small streams through molten cast iron, in iron vessels (converters) which are lined with ganister, a silicious sandstone. These can be rotated on trunnions. Basic Bessemer steel is made in similar converters by the Thomas-Gilchrist or basic process, which can be applied to pig irons containing phosphorus. The latter is removed by giving the converter a basic lining of calcined magnesium limestone mixed with tar. In the _Martin_ process steel is obtained by melting together pig iron with steel scrap, wrought iron scrap, &c., on the hearth of a Siemens regenerative furnace with a silicious lining. In iron smelting the most important danger is from _blast furnace gas_ rich in carbonic oxide. Sulphur dioxide, hydrocyanic acid, and arseniuretted hydrogen gas may possibly be present. When work was carried out in blast furnaces with open tops the workers engaged in charging ran considerable risk. But as the blast furnace gas is rich in carbonic oxide and has high heating capacity these gases are now always led off and utilised; the charging point is closed by a cup (Parry’s cup and cone charger) and only opened from time to time mechanically, when the workers retire so far from the opening as to be unaffected by the escaping gas. The gas is led away (fig. 29) through a side opening into special gas mains, is subjected to a purifying process in order to rid it of flue dust, and then used to heat the blast, fire the boilers, or drive gas engines. Severe blast furnace gas poisoning, however, does occur in entering the mains for cleaning purposes. Numerous cases of the kind are quoted in the section on Carbonic oxide poisoning. The gases evolved on tapping and slag running can also act injuriously, and unpleasant emanations be given off in granulating the slag (by receiving the fluid slag in water). In the puddling process much carbonic oxide is present. Other processes, however, can scarcely give rise to poisoning. The _basic slag_ produced in the Thomas-Gilchrist process is a valuable manure on account of the phosphorus it contains; it is ground in edge runners, and then reduced to a very fine dust in mills and disintegrators. This dust has a corrosive action already referred to in the chapter on Phosphorus and Artificial Manures. The poisoning caused by _ferro-silicon_ is of interest. Iron with high proportion of silicon has been made in recent years on a large scale for production of steel. Some 4000 tons of ferro-silicon are annually exported to Great Britain from France and Germany. It is made by melting together iron ore, quartz, coke, and lime (as flux) at very high temperature in electrical furnaces. The coke reduces the quartz and ore to silicon and metal with the production of ferro-silicon. Certain grades, namely those with about 50 per cent. silicon, have the property of decomposing or disintegrating into powder on exposure for any length of time to the air, with production of very poisonous gases containing phosphoretted and arseniuretted hydrogen. The iron and quartz often contain phosphates, which in presence of carbon and at the high temperature of the electrical furnace would no doubt be converted into phosphides combining with the lime to form calcium phosphide; similarly any arsenic present would yield calcium arsenide. These would be decomposed in presence of water and evolve phosphoretted and arseniuretted hydrogen gas. In addition to its poisonous properties it has also given rise to explosions. [In January 1905 fifty steerage passengers were made seriously ill and eleven of them died. In 1907 five passengers died on a Swedish steamer as the result of poisonous gases given off from ferro-silicon, and more recently five lives were lost on the steamer _Aston_ carrying the material from Antwerp to Grimsby.[C] This accident led to full investigation of the subject by Dr. Copeman, F.R.S., one of the Medical Inspectors of the Local Government Board, Mr. S. R. Bennett, one of H.M. Inspectors of Factories, and Dr. Wilson Hake, Ph.D., F.I.C., in which the conclusions arrived at are summarised as follows: 1. Numerous accidents, fatal and otherwise, have been caused within the last few years by the escape of poisonous and explosive gases from consignments of ferro-silicon, which, in every instance, have been found to consist of so-called high-grade ferro-silicon, produced in the electric furnace. 2. These accidents, for the most part, have occurred during transport of the ferro-silicon by water, whether in sea-going vessels or in barges and canal-boats plying on inland waters. 3. These accidents have occurred in various countries and on vessels of different nationalities, while the ferro-silicon carried has, in almost every instance, been the product of a different manufactory. 4. Ferro-silicon, especially of grades containing from 40 per cent. to 60 per cent. of silicon, is invariably found to evolve considerable quantities of phosphoretted hydrogen gas, and, in less amount, of arseniuretted hydrogen, both of which are of a highly poisonous nature. A certain amount of the gas evolved is present, as such, in the alloy, being ‘occluded’ in minute spaces with which its substance is often permeated. 5. As the result of careful investigation, it has been shown that certain grades of ferro-silicon—notably such as contain about 33 per cent., 50 per cent., and 60 per cent. of silicon—even when manufactured from fairly pure constituents, are both brittle and liable to disintegrate spontaneously, this latter characteristic being apt to be specially marked in the case of the 50 per cent. grade. All these grades are commonly employed at the present time. 6. In the event of disintegration occurring, the amount of surface exposed will, obviously, be greater than if the mass were solid. 7. Evolution of poisonous gases is greatly increased by the action of moisture, or of moist air, under the influence of which phosphoretted hydrogen is generated from calcium phosphide, which, in turn, is formed, in large part, at any rate, from the calcium phosphate present in anthracite and quartz, at the high temperature of the electric furnace. If spontaneous disintegration of the alloy also occurs, much larger quantities of gas would be given off from such friable and unstable material, other conditions being equal. The greater or less tendency of a given sample to evolve poisonous gases, and even a rough estimate of their probable amount may be arrived at by the use of test-papers prepared with silver nitrate. 8. There is no evidence that low-grade ferro-silicon (10 to 15 per cent.), produced in the blast-furnace, has ever given rise to accidents of similar character to those known to have been caused by the high-grade electrically produced alloy. Blast-furnace ferro-silicon does not evolve poisonous gases even in presence of moisture. 9. As regards ferro-silicon produced in the electric furnace, the evidence available goes to show that certain percentage grades are practically quite innocuous. This statement applies to grades of alloy of a silicon content up to and including 30 per cent., and probably also, though in considerably less degree, to those of 70 per cent. and over. 10. In view of the fact that the use of ferro-silicon of grades ranging between 30 per cent. and 70 per cent. apparently is not essential in metallurgical operations, with the possible exception of basic steel manufacture, it will be advisable that the production of this alloy of grades ranging between these percentages should be discontinued in the future. 11. The proprietors of iron and steel works making use of ferro-silicon will assist in the protection of their workpeople, and at the same time act for the public benefit by restricting their orders to grades of this material, either not exceeding 30 per cent., or of 70 per cent. and upwards, according to the special nature of their requirements. 12. But as, pending international agreement on the question, intermediate percentages of ferro-silicon will doubtless continue to be manufactured and sold, the issue, by the Board of Trade, of special regulations will be necessary in order to obviate, so far as may be possible, chance of further accidents during the transport of this substance. _Inter alia_, these regulations should require a declaration of the nature, percentage, date of manufacture, and place of origin of any such consignment. The suggested regulations are printed on p. 291.] ZINC Industrial poisoning from zinc is unknown. The chronic zinc poisoning among spelter workers described by Schlockow with nervous symptoms is undoubtedly to be attributed to lead. COPPER: BRASS _Occurrence of brass-founder’s ague._—Opinion is divided as to whether pure copper is poisonous or not. Lehmann has at any rate shown experimentally that as an industrial poison it is without importance. Occurrence, however, of brass-founder’s ague is undoubtedly frequent. Although neither pure zinc nor pure copper give rise to poisoning, yet the pouring of brass (an alloy of zinc and copper) sets up a peculiar train of symptoms. As the symptoms are transient, and medical attendance is only very rarely sought after, knowledge of its frequency is difficult to obtain. Sigel,[1] who has experimented on himself, believes that the symptoms result from inhalation of superheated zinc fumes. In large well-appointed brass casting shops (as in those of Zeiss in Jena) incidence is rare. Lehmann[2] very recently has expressed his decided opinion that brass-founder’s ague is a zinc poisoning due to inhalation of zinc oxide and not zinc fumes. This conclusion he came to as the result of experiments on a workman predisposed to attacks of brass-founder’s ague. Lehmann’s surmise is that the symptoms are due to an auto-intoxication from absorption of dead epithelial cells lining the respiratory tract, the cells having been destroyed by inhalation of the zinc oxide. He found that he could produce typical symptoms in a worker by inhalation of the fumes given off in burning pure zinc. _Metal pickling._—The object of metal dipping is to give metal objects, especially of brass (buckles, lamps, electric fittings, candlesticks, &c.), a clean or mat surface and is effected by dipping in baths of nitric, hydrochloric, or sulphuric acid. Generally after dipping in the dilute bath the articles go for one or two minutes into strong acid, from which injurious fumes, especially nitrous fumes, develop with occasionally fatal effect (see the chapter on Nitric Acid). Unfortunately, there are no references in the literature of the subject as to the frequency of such attacks. Recovery of gold and silver has been already referred to in the chapters on Mercury, Lead, and Cyanogen. Mention must be made of _argyria_. This is not poisoning in the proper sense of the word, as injury to health is hardly caused. Argyria results from absorption of small doses of silver salts which, excreted in the form of reduced metallic silver, give the skin a shiny black colour. Cases are most frequently seen in silverers of glass pearls who do the work by suction. Local argyria has been described by Lewin in silvering of mirrors and in photographers. III. OCCURRENCE OF INDUSTRIAL POISONING IN VARIOUS INDUSTRIES The most important facts have now been stated as to the occurrence of poisoning in industry, and there remain only a few gaps to fill in and to survey briefly the risks in certain important groups of industry. TREATMENT OF STONE AND EARTHS Lime Burning: Glass Industry Lead poisoning in the ceramic industry (earthenware, porcelain, glass, polishing of precious stones, &c.) has been dealt with in detail in the chapter on Lead. There is further the possibility of chrome-ulceration, of arsenic poisoning, and conceivably also of manganese. Further, poisoning by _carbonic oxide_ and carbon dioxide may occur from the escape of furnace gases where hygienic conditions are bad. In charging lime kilns poisoning by carbonic oxide has occurred. The report of the Union of Chemical Industry in 1906 describes the case of a workman who was assisting in filling the kiln with limestone. As the furnace door was opened for the purpose gas escaped in such amount as to render him unconscious. He was picked up thirty minutes later, but efforts at resuscitation failed. Carbonic oxide poisoning, again, may arise from the use of Siemens regenerative furnaces, especially glass furnaces: details are given in the chapter on Illuminating Gas. _Hydrofluoric acid_ is present as an industrial poison in _glass etching_ (see Fluorine Compounds). Persons employed in this process suffer from inflammation of the respiratory tract and ulceration of the skin of the hands. I could not find any precise statement as to the frequency of the occurrence of such injuries. Use of sand-blasting to roughen the surface of glass has to some extent taken the place of etching by hydrofluoric acid. TREATMENT OF ANIMAL PRODUCTS In _tanning_ use of arsenic compounds for detaching the wool from skins and of gas lime for getting rid of hair may cause injury to health. With the latter there is possibility of the action of cyanogen compounds (see the chapters on Arsenic and Cyanogen). PREPARATION OF VEGETABLE FOOD STUFFS AND THE LIKE In _fermentation_ processes as in breweries and the sugar industry accumulations of carbonic acid gas occur, and suffocation from this source has been repeatedly described. Mention in this connection should be made of the use of salufer containing some 2 per cent. of silicofluoric acid as a preservative and antiseptic in beer brewing. In the _sulphuring_ of hops, wine, &c., the workers may run risk from the injurious action of sulphur dioxide. _Arsenic_ in the sulphuric acid used for the production of _dextrine_ may set up industrial poisoning. Poisoning from _ammonia_ gas can occur in _cold storage_ premises. Industrial poisoning from tobacco is not proved, but the injurious effect of the aroma and dust of tobacco—especially in women—in badly arranged tobacco factories is probable. WOOD WORKING _Injurious woods._—In recent literature there are several interesting references to injury to health from certain poisonous kinds of wood—skin affections in workers manipulating satinwood, and affections of the heart and general health in workers making shuttles of African boxwood. Details of these forms of poisoning are reported from England and Bavaria. The wood used for making the shuttles was West African boxwood (Gonioma Kamassi). It appears that the wood contains an alkaloidal poison which affects the heart’s action. The workers suffered from headache, feeling of sleepiness, lachrymation, coryza, difficulty of breathing, nausea, and weakness. Four workers had to give up the work because of the difficulty in breathing. Inquiry was made by Dr. John Hay of Liverpool in 1908 and by the medical inspector of factories in 1905. The following table shows the symptoms found: +----------------------+-----------------------------------+ \| \| Persons Examined. \| \| +-----------------+-----------------+ \| Symptoms. \| 1905. \| 1907-1908. \| \| +-------+---------+-------+---------+ \| \|Number.\|Per cent.\|Number.\|Per Cent.\| \| (1) \| (2) \| (3) \| (4) \| (5) \| +----------------------+-------+---------+-------+---------+ \|Headache \| 27 \| 24·1 \| 18 \| 22·8 \| \|Feeling of somnolence \| 10 \| 9·0 \| 17 \| 21·5 \| \|Running of eyes \| 13 \| 11·6 \| 9 \| 11·3 \| \|Running of nose \| 28 \| 25·0 \| 20 \| 28·0 \| \|Breathing affected \| 34 \| 30·4 \| 13 \| 16·4 \| \|Nausea or sickness \| 13 \| 11·6 \| 3 \| 3·8 \| \|Faintness or weakness \| 11 \| 9·6 \| 1 \| 1·2 \| +----------------------+-------+---------+-------+---------+ The later inquiry shows considerable diminution in the amount of complaint as to respiratory trouble. This may have been due to the improved conditions of working, freely acknowledged by the men. Men were examined who had complained of the effects of the wood in 1905, and had continued uninterruptedly at the same kind of work during the interval without any obvious further injury to their health, although they preferred working on other woods. East Indian boxwood had to be discarded in the shuttle trade owing to its irritant action on the eyes. Sabicu wood from Cuba was stated to give off ‘a snuffy dust under the machine and hand planes, the effect of which upon the worker is to cause a running at the eyes and nose, and a general feeling of cold in the head. The symptoms pass off in an hour or so after discontinuance of work.’ Reference was made in the report for 1906 to eczematous eruptions produced by so-called Borneo rosewood, a wood used owing to its brilliant colour and exquisite grain in fret-saw work. The Director of the Imperial Institute experimented with this wood, but failed to discover injurious properties in it. At the same time experiments with the wood and sawdust of East and West Indian satinwood were undertaken, but also without result. From inquiries subsequently made it appeared that much confusion existed as to the designation ‘satinwood,’ as under this name were classed both East and West Indian satinwood and also satin walnut. The evidence was clear that East Indian satinwood was more irritating than West Indian. Satin walnut wood is apparently harmless. In the shipbuilding yards of East London, Glasgow, and Bristol affections of the skin were recognised, but susceptibility to the wood varied. One man asserted that merely laying a shaving on the back of his hand would produce a sore place. The injurious effects here seem to disappear quickly. Exhaust ventilation is applied, but there is a tendency to give up the use of the wood. Isolated cases of illness have been ascribed to working teak and olive wood. In Sheffield the following are held to be irritating: ebony, magenta rosewood, West Indian boxwood, cocos wood. Some kinds of mahogany are said to affect the eyes and nose. Use of methylated spirit in polishing furniture is said to lead to injury to health although not to set up actual poisoning. Lead poisoning can occur from the sand-papering of coats of paint applied to wood. In impregnating wood with creosote and tar the effects on the skin noted in the chapter on Tar are observed. TEXTILE INDUSTRY In getting rid of the grease from animal wool carbon bisulphide or _benzine_ may be used. The process of _carbonising_ in the production of shoddy may give rise to injury to health from acid fumes. Lead poisoning used to be caused by the knocking together of the leaden weights attached to the Jacquard looms. This is a thing of the past, as now iron weights are universal. Opportunity for lead poisoning is given in the weighting of yarn—especially of silk with lead compounds. In _bleaching_ use of chlorine and sulphur dioxide has to be borne in mind. In _chemical cleaning_ poisoning by benzine may occur. In _dyeing_ and _printing_ use of poisonous colours is lessening, as they have been supplanted by aniline colours. On occurrence of aniline poisoning in aniline black dyeing see the section on Aniline. Use of lead colours and of chromate of lead are dealt with in special sections. PART II _THE SYMPTOMS AND TREATMENT OF INDUSTRIAL POISONING_ In this section the most important diseases and symptoms of industrial poisoning will be described. In doing this—considering the mainly practical purpose of this book—theoretical toxicological details and any full discussion of disputed scientific points will be omitted. I. INTRODUCTORY Hitherto in this book we have intentionally followed the inductive method, from the particular to the general: we began by citing a number of important instances of industrial poisoning, but only now will endeavour be made to give a definition of the terms ‘poison’ and ‘poisoning.’ Attempts at such definitions are numerous; every old and new text-book of toxicology contains them. A few only hold good for our purpose. It is characteristic that Lewin, after attempting a definition of the conception ‘poisoning,’ himself rejects it and declares that he can see no practical disadvantage in the impossibility of defining this notion, because deductions based upon the knowledge of undoubted cases can never be dispensed with, even if a definition were possible: one justification the more for our inductive method. But we will not quite dispense with a definition. _Poisons are certain substances which are able chemically to act on an organism in such a way as to effect a permanent or transient injury to its organs and functions; an injury consequently to the health and well-being of the person affected; this injury we call poisoning._ In the present book we have refrained from including industrial infections among industrial poisonings, and the subject has been limited to poisoning in the restricted and current sense of the word. An industrial poison is a poison employed, produced, or somehow occasioned in industrial occupation, which is brought about inadvertently, and consequently against the will of the person poisoned. From a simple survey of the action of industrial poisons in general we may group them as follows: 1. Poisons which act _superficially_, i.e. which cause in the organs which they touch gross anatomical lesions (irritation, corrosion, &c.)—so-called contact-effect. To this class belong especially irritant and corrosive poisons. 2. _Blood_ poisons, i.e. poisons which are absorbed by the blood and change it; this change can affect either the blood colouring-matter, with which certain poisons form chemical compounds, or the blood corpuscles themselves can be altered or destroyed (for instance, poisons having a hæmolytic action). 3. Poisons with definite _internal_ action, so-called remote or specific effect. To this class belong the poisons which, after being absorbed into the system, act upon definite organs or tissues in a specific manner (nerve poisons, heart poisons, &c.). It is indeed possible for one and the same poison to display two or all three of these modes of action. The effect of poison depends upon an interaction of the poison and the organism, or its single organs. Selection as regards quality and quantity is a property of the organism as well as of the poison: the nature and amount of the poison taken in are determining factors on the one side, and on the other the constitution, size, and weight of the affected organism. The chemical constitution of the poisonous substance determines the qualitative property of the poison. Further, certain physical properties of the poison determine its action, especially its form, solubility in water, and its power of dissolving fat. These affect its susceptibility to absorption, to which point we shall return shortly; the hygroscopic capacity of a poison produces a highly irritant and corrosive action. Industrial poisons can be absorbed (1) as solid substances, (2) as liquids, and (3) as gases. Since industrial poisoning, as defined above, is of course neither desired nor intended by the sufferer, who unsuspectingly takes into his system poison used or developed in the factory, solid substances in finely divided condition—in the form of dust—can be considered as industrial poisons. Accordingly, industrial poisons can be classed as due to dust, gases, and liquids. The poison may be introduced into the body through the functional activity of the organism by the lungs or alimentary tract, or it may penetrate the uninjured or injured surface of the skin. Industrial poisons which contaminate the air of the factory are inhaled—these are consequently either poisonous dusts or gases and vapours. As a rule, only industrial poisons in a liquid form enter through the skin, which may be either intact or wounded; gaseous poisons seldom do; poisons in the form of fat or dust can only pass through the skin after they have been first dissolved by the secretions of the skin or of a wound, so that they come to be absorbed in solution. Most frequently those liquid poisons which are capable of dissolving the fat of the skin are thus absorbed, and next, such liquids as have a corrosive effect, breaking down the resistance of the skin covering and producing an inflamed raw surface. But such poisons much more easily enter through the mucous membrane, as this naturally offers a much weaker resistance than the skin. From a quantitative point of view it is especially the amount of poison actively assimilated which determines the effect. Every poison is without effect if assimilated in correspondingly small quantities. There is consequently a minimum poisonous dose, after which the poison begins to act; but this minimum dose can only be ascertained and specified when the qualitative properties and the weight of the organism are also taken into consideration; it has therefore a relative value. The strongest effect which a poison is able to produce is the destruction of the life functions of the organism, the fatal effect. This fatal dose, however, can only be determined relatively to the qualities of the organism in question. Not only is the absolute quality of the poison of decisive significance, but the degree of concentration often influences its action, that is to say, the greater or less amount of effective poison contained in the substance conveying it into the organism; concentration plays an important part in many industrial poisons, especially, as is obvious, in corrosive poisons. A further important point is the time which it takes to absorb the poison. The action of the poison—the whole expression of the symptoms of poisoning—is essentially influenced by this fact. Usually gradual and repeated absorption of small quantities produces slow onset of symptoms, while sudden absorption of larger quantities of poison brings about rapid onset of illness. In the former case the poisoning is called _chronic_, in the latter, _acute_. Acute industrial poisoning is sometimes so sudden that the affected person cannot withdraw himself in time from the influence of the poison, nor prevent its entrance in considerable quantities into his system; this is often caused by the fact that the effect of the poison is so rapid that he is often suddenly deprived of power to move or of consciousness, and remains then exposed to the action of the poison until help comes. Such accidents are mostly caused by poisonous gases. Occasionally also considerable quantities of poison enter quite unnoticed into the body, such as odourless poisonous gases in breathing, or poisonous liquids through the skin. In chronic industrial poisoning unsuspected accumulation of poison takes place, until symptoms of illness ultimately reveal themselves; as the first stages of poisoning are not recognised in time by the person affected, he continues exposed to the influence of the poison for weeks, months, even years, until the chronic effect has reached its full development and becomes obvious. Such insidious industrial poisoning arises through the continual absorption into the lungs or stomach of small quantities of poisonous dust, gases, and vapours, during constant or frequent work in an atmosphere containing such gases; poisonous liquids also, by soiling hands and food, or by penetrating the skin, can produce slow industrial poisoning. Industrial poisoning which in respect of its duration stands midway between acute and chronic is called sub-acute poisoning. This usually means that more frequent absorption of greater quantities of poison has taken place, though not in doses large enough to produce an immediately acute effect. This is important legally because industrial poisonings caused through the sudden absorption of poison in sufficient quantity to act immediately or to bring about subsequent symptoms of poisoning, are reckoned as accidents. Thus acute and many sub-acute industrial poisonings are accounted accidents. Chronic industrial poisonings, acquired gradually, count as illnesses. But as in certain cases it cannot be decided whether sudden or gradual absorption of the industrial poison is in question, this distinction is an unnatural one. It is also unnatural in the legal sense, for there is often no material reason for regarding as legally distinct cases of chronic and acute industrial poisoning. To this we shall refer later in discussing the question of insurance against industrial poisoning. We have from the outset assumed that the effect of the poison depends not only on the nature of the poison itself, but also on that of the organism, considered both quantitatively and qualitatively. Significant in a quantitative respect is the body weight of the organism, and the fatal dose of the poison must be ascertained and stated in connection with the body weight, calculated as a rule per kilo of the live weight. The qualitative point of view must reckon with the differing susceptibility of organisms for poison. This varying susceptibility to the action of poison, the causes of which are very obscure, is called disposition. Different species (of animals and men) exhibit often very different degrees of susceptibility towards one and the same poison; the differences in this respect are often very considerable, and one cannot simply transfer the experience experimentally gained from one species of animal to man or another species of animal, without further experiment. Besides disposition, sex, and still more age, often determine within the same species marked difference of susceptibility to a poison. Further, there is an individual disposition due to qualities peculiar to the individual, which makes some persons more than usually immune and others specially susceptible. Individuals weakened by illness are particularly susceptible to poisoning. Two diseases, in especial, favour the operation of poison, influencing disastrously the capacity for assimilating food, and reducing the general resisting power of the body; of these tuberculosis stands first. Individual disposition plays in industrial poisoning a part which must not be under-estimated; it determines the possibility of acclimatisation to a poison; some individuals capable of resistance habituate themselves—often comparatively easily—to a poison, and become, up to a certain limit, immune against it, that is, they can tolerate a quantity which would be injurious to others not so accustomed. With other individuals, however, the opposite effect is apparent. Repeated exposure to the action of the poison leads to an increased susceptibility, so that acclimatisation is not possible. Innate hyper-sensitiveness of the individual towards a poison is called idiosyncrasy. Frequently, for example, this quality shows itself as hyper-sensitiveness of the skin towards the harmful action of certain poisons. A marked lowering in the sensitiveness, innate or acquired, of the organism towards a poison is called immunity. The possibility of the absorption and action of a poison presupposes—speaking generally—its solubility, and indeed its solubility in the body juices. In general, poison can be absorbed at very different points of the body; so far as industrial poisons are concerned, these are the mucous membrane of the respiratory passages, the mucous membrane of the digestive tract, and the skin, intact or broken. The rapidity of absorption depends on the nature of the poison, of the individual, and the channel of absorption. Of industrial poisons gases are relatively the most quickly absorbed; sometimes indeed so swiftly that the effect follows almost immediately. Elimination of industrial poisons is effected principally by the kidneys, the intestinal canal, the respiratory organs, and, more rarely, the skin. Rapidity of elimination also depends on the nature of the poison and of the person poisoned. If elimination is insufficient, or absorption takes place more quickly than excretion, the poison accumulates in the body, and has a cumulative effect which in chronic industrial poisonings plays a very important rôle. Under certain circumstances poisons are not thrown off, but stored up—fixed—in the body. The poison absorbed in the body can act unchanged from the place where it is stored. A number of poisons, however, undergo in the organism chemical change through which the action of the poison is partly lessened, rarely increased. Among such changes and weakening of the poison are: oxidation, as, for example, of organic poisons into their final products (carbonic acid, water, &c.), oxidation of benzene into phenol, oxidation of sulphur dioxide into sulphuric acid, &c.; reduction in the case of metals, peroxides, &c.; neutralisation of acids by alkaline juices; chemical union (for instance, of aromatic compounds with sulphuric acid). The splitting up of albuminous bodies is not of importance in regard to industrial poisons. GENERAL REMARKS ON THE TREATMENT OF INDUSTRIAL POISONINGS Although in industrial poisoning the importance of treatment is small in comparison with that of preventive measures, in discussing particular forms of poisoning, full weight must be given to it; and in order to avoid repetition, certain points will be brought forward here. Of the treatment of chronic industrial poisonings not much in general can be said; unfortunately, special treatment has often little chance. It will usually be of advantage to maintain the activity of the excretory organs. So far as there is question of poisons affecting metabolism and injuriously influencing the general state of nutrition, treatment aiming at improving the general health and strength offers hope of success. For nervous symptoms, especially paralysis, disturbance in sensation, &c., treatment generally suitable to nervous diseases can be tried (electro-therapeutics, baths, &c.). In treatment of acute industrial poisonings, which often demand the prompt intervention of laymen, ‘first aid’ is more hopeful. The most important general rules of treatment arise in reference to irritant poisons which produce ulceration of the skin, and further in regard to those poisons which cause unconsciousness, especially blood poisons. When an irritant poison is acting on the skin, the first object to be aimed at is naturally the immediate removal of the cause of corrosion by water, or, better still, neutralisation by an alkaline solution (for example, soda solution) in the case of corrosive acids, and weak acids (organic acids, acetic acid, citric acid) in the case of caustic action by alkalis. Such remedies must be at hand in factories as part of the equipment for first aid, where irritant poisonings can occur. In those industrial poisonings which result in loss of consciousness, arrest of respiration and suffocation, attempts at resuscitation should at once be made. In these attempts at resuscitation, _artificial respiration_ is of the greatest importance; of course the sufferer must first be withdrawn from the influence of the poison, i.e. be brought into fresh air. Great care must be taken, especially where it is necessary to enter places filled with a poisonous atmosphere, to prevent the rescuers, as is often the case, themselves falling victims to the influence of the poison. They should be provided with suitable smoke helmets or breathing apparatus. We will not describe the methods of resuscitation and artificial respiration universally enjoined; they can be found in every first-aid handbook. Emphasis is laid on the great importance of _treatment by oxygen_ in cases of industrial poisoning through gaseous blood poisons, as this treatment is attended with good results. Apparatus for the administration of oxygen should be kept wherever there exists the possibility of such poisoning, especially in mines, smelting works, chemical factories, and chemical laboratories. Oxygen treatment rests on the fact that by raising the pressure of the oxygen from 113 mm., as it is generally in ordinary air, to 675 mm., which is reached in presence of pure oxygen, the quantity of oxygen absorbed in the blood rises from 0·3 to 1·8 per 100 c.c. Further, the saturation of the hæmoglobin, the colouring matter of the blood, undergoes an increase of 2·4 per cent. This increase of oxygen in the blood can save life in cases where through poisoning a deficiency of oxygen has resulted. The introduction of oxygen is done by special apparatus which acts essentially on the principle that during inhalation oxygen is pressed into the lungs which are below normal physiological pressure, while exhalation is effected by a deflating arrangement when the poisoned individual no longer breathes of his own accord. When natural breathing begins, the introduction of oxygen without special apparatus generally suffices. [Illustration: FIG. 30.—Dräger’s Oxygen Box I Oxygen cylinder; A Valve on cylinder; B Manometer; C Key for opening and closing the flow of oxygen; F Economiser; H Facepiece.] Dräger’s _oxygen apparatus_ (fig. 30) consists of a small oxygen cylinder provided with a closing valve, a small manometer, a so-called ‘automatic’ reducing valve with an arrangement for opening and closing the oxygen supply, a bag to act as a receiver or economiser, a breathing mask, and a metal tube connecting the breathing mask with the other parts of the apparatus. The oxygen cylinder, when filled, contains about 180 litres of oxygen, and the manometer allows the manipulator to control at any time whatever oxygen it still contains. The automatic arrangement not only reduces the pressure but at the same time controls the supply of oxygen. This dose is fixed at three litres of oxygen per minute, so that the apparatus with the same oxygen cylinder will last for sixty minutes. The oxygen is not inhaled pure, but is mixed with atmospheric air according to need, and in order to make this possible the breathing mask is provided with a small hole through which atmospheric air finds entrance. [Illustration: FIG. 31.—Oxygen Inhaling Apparatus] [Illustration: FIG. 32.—Showing apparatus in use (_Siebe, Gorman & Co._)] As the oxygen flows continuously from the cylinder waste during exhalation is prevented by the economiser, in which, during exhalation, the inflowing oxygen accumulates, to be absorbed again in inhalation. A small relief valve in the screw head of the bag prevents the entrance into it of exhaled air. [Illustration: FIG. 33.—Dräger’s Pulmotor (_R. Jacobson_)] Another oxygen inhaling apparatus for resuscitating purposes, that of Siebe, Gorman & Co., is illustrated in figs. 31 and 32. Dräger also constructs an apparatus called the ‘Pulmotor’ which simultaneously accomplishes the introduction of oxygen and artificial respiration. Inflation and deflation are effected by an injector driven by compressed oxygen; this alternately drives fresh air enriched with oxygen into the lungs and then by suction empties them again. While with the mechanical appliances of resuscitation belonging to older systems the hand of the helper regulated the rate of breathing, in the case of the Pulmotor the lungs, according to their size, automatically fix the rate of breathing; as soon as the lungs are filled the apparatus of its own accord marks the moment for ‘deflation,’ and as soon as they are emptied of ‘inflation.’ This automatic reversal is effected by a little bellows which is connected with the air tubes. During inflation the same pressure is exerted in the bellows as in the lungs. As soon as the lungs are filled, the pressure in the bellows increases and it expands, its forward movement causing the reversal to deflation. When the lungs are emptied the bellows contracts, and through this contraction results the reversal to inflation. If, in an exceptional case, the breathing for some reason does not act automatically, the hand of the helper can manipulate it by means of a backward and forward movement of a lever. According to choice, either a nose-mask or a mask covering both mouth and nose can be worn. Combined with the regular apparatus for resuscitation is an ordinary apparatus for the inhalation of oxygen; by the simple altering of a lever, either the one or the other can be employed. II. INDUSTRIAL POISONING IN PARTICULAR INDUSTRIES After the foregoing general remarks we may now consider various points of view in regard to classification of industrial poisonings into groups: (1) Toxicological, based on the action of the poisons. (2) Chemical, based on the chemical composition of the poisons. (3) Physical, based on the varying density of the poisons. (Division into solid (in form of dust), gaseous, and liquid poisons.) To which may be added: (4) Classification according to the source of the poisoning and therefore according to industry, upon which Part I is mainly based. In this section (Part II) a system is adopted which takes into consideration as far as possible all the principles of division mentioned above, in order to classify industrial poisonous substances in such a manner that general practical conclusions can be clearly drawn, and supervision rendered easy. _GROUP: MINERAL ACIDS, HALOGENS, INORGANIC HALOGEN COMPOUNDS, ALKALIS_ Common to this group is a strong corrosive and irritant effect, varying however in degree; as gases this group corrode or inflame the mucous membrane of the respiratory passages, and in liquid form or in solution, the skin. Besides this superficial effect single members of this group, especially those containing nitrogen, produce a remote effect upon the blood. After absorption of the acids a decrease in the alkalinity of the blood can take place and in its power to take up carbonic acid, thus vitally affecting the interchange of gases in the body, and producing symptoms of tissue suffocation. As regards treatment in the case of acids and alkalis, neutralisation has been already mentioned; further, oxygen treatment may be recommended in cases where the blood has been injuriously affected. In cases of poisoning through breathing in acid vapours, inhalation of extremely rarefied vapour of ammonia or of a spray of soda solution (about 1 per cent.) is advisable. MINERAL ACIDS =Hydrochloric Acid= (HCl) is a colourless, pungently smelling gas which gives off strong white fumes. Experiments on animals, carefully carried out by Leymann, produced the following symptoms. Even in a concentration of 2-5 per thousand clouding of the cornea ensues, and after about an hour inflammation of the conjunctiva, violent running from every exposed mucous membrane with marked reddening, and frequently inflammation (necrosis) of the septum of the nose; the lungs are distended with blood, here and there hæmorrhages occur in the respiratory and also in the digestive tracts. The animal dies of œdema (swelling) of the lungs and hæmorrhage into the lungs if exposed long enough to the action of HCl, even though (according to Lehmann) there may not be accumulation of HCl in the blood; the chief effect is the irritant one; 1·5-5 per thousand parts HCl in the air suffices, after three or four hours’ exposure, to affect smaller animals (rabbits) so much that they die during the experiment or shortly after it. Man can tolerate an atmosphere containing 0·1 to 0·2 per thousand HCl; a somewhat greater proportion of HCl produces bronchial catarrh, cough, &c. The solution of hydrochloric acid in water is about 40 per cent. Simply wetting the skin with concentrated solution of hydrochloric acid does not generally have an irritant effect unless persisted in for some time; the action of the acid, when continued, has a marked effect upon the mucous membranes and upon the eyes. The same treatment already recommended in the introductory remarks on poisoning by inhalation of acid fumes in general applies. =Hydrofluoric Acid= (HFl), a pungently smelling, colourless gas, causes even in weak solutions (0·02 per cent.) irritant symptoms (catarrh of the mucous membrane of the respiratory organs, lachrymation, &c.). Stronger solutions set up obstinate ulcers, difficult to heal, in the mucous membrane and the skin. =Silico-fluoric Acid= (H₂SiFl₆) produces an analogous though somewhat less marked corrosive action. As regards treatment the reader is again referred to the introductory sentences on this group. =Sulphur Dioxide= (SO₂) is a colourless, pungently smelling gas which, acting in low concentration or for a short period, causes cough and irritation of the mucous membrane of the respiratory passages and of the eyes; acting for a longer period, it sets up inflammation of the mucous membrane, bronchial catarrh, expectoration of blood, and inflammation of the lungs. As Ogata and Lehmann have proved by experiments—some of them made on man—a proportion of 0·03-0·04 per thousand of sulphur dioxide in the air has a serious effect on a person unaccustomed to it, while workmen used to this gas can tolerate it easily. As sulphur dioxide probably does not affect the blood, treatment by oxygen inhalation is useless. Otherwise the treatment spoken of as applying to acid poisonings in general holds good. =Sulphuric Acid= (H₂SO₄). Concentrated sulphuric acid occasionally splashes into the eye or wets the skin, causing severe irritation and corrosion, unless the liquid is quickly washed off or neutralised. If the action of the acid persists, the corrosive effect becomes deepseated and leads to disfiguring scars. =Nitrous Fumes, Nitric Acid.=—Nitric oxide (NO) oxidises in the air with formation of red fumes composed of nitrogen trioxide (N₂O₃) and nitrogen peroxide (NO₂). These oxides are contained in the gases evolved from fuming nitric acid and where nitric acid acts upon metals, organic substances, &c. Industrial poisoning by nitrous fumes is dangerous; unfortunately it frequently occurs and often runs a severe, even fatal, course; sometimes numerous workers are poisoned simultaneously. The main reason why nitrous fumes are so dangerous is because their effect, like that of most other irritant gases, is not shown at once in symptoms of irritation, such as cough, cramp of the glottis, &c., which would at least serve as a warning to the affected person; on the contrary, generally no effect at all is felt at first, especially if the fumes are not very concentrated. Symptoms of irritation usually appear only after some hours’ stay in the poisonous atmosphere. By this time a relatively large quantity of the poisonous gas has been absorbed, and the remote effect on the blood induced. The first symptoms of irritation (cough, difficulty of breathing, nausea, &c.) generally disappear when the affected person leaves the charged atmosphere, and he then often passes several hours without symptoms, relatively well. Later severe symptoms supervene—often rather suddenly—difficulty of breathing, fits of suffocation, cyanosis, and copious frothy blood-stained expectoration with symptoms of inflammation of the bronchial tubes and lungs. These attacks may last a longer or shorter time, and in severe cases can lead to death; slight cases end in recovery, without any sequelæ. In poisoning by nitrous acid fumes, oxygen inhalation, if applied in time, undoubtedly holds out hope of success, and should always be tried. Chloroform has been repeatedly recommended as a remedy. Probably its inhalation produces no actual curative effect, but only an abatement of the symptoms through the narcosis induced. Nitric acid (HNO₃) in solution has an irritant corroding action if, when concentrated, it comes into contact with the skin or mucous membrane. THE HALOGENS (CHLORINE, BROMINE, IODINE) Chlorine (Cl) is a yellow-green, pungently smelling gas, Bromine (Br) a fuming liquid, and Iodine (I) forms crystals which volatilise slightly at ordinary temperatures. According to Lehmann’s experiments on animals the effect of chlorine gas and bromine fumes is completely similar. Lehmann and Binz assume that chlorine has a twofold effect: (1) narcotic, paralysing the outer membrane of the brain, and (2) the well-known irritant action upon the mucous membrane, producing a general catarrh of the air passages, and inflammation of the lungs; it is, however, only the latter which causes menace to life. Other writers do not mention the narcotic effect upon the brain and assume that the halogens when brought into contact with the mucous membrane are quickly converted into halogen hydrides, and, as such, produce a corrosive effect. According to Lehmann, even 0·01 per thousand Cl or Br in the air is injurious, even 0·1 per thousand produces ulceration of the mucous membrane, and one or two hours’ exposure to the poison endangers life. Lehmann has further tested (on dogs) acclimatisation to chlorine, and finds that after a month the power of resistance to chlorine appears to be increased about ten times. In a further series of experiments the same author has proved that even the smallest quantities of chlorine present in the atmosphere are completely absorbed in breathing. Continued or frequent action of chlorine upon the organism produces symptoms which have been described as chronic chlorine poisoning—such as anæmia and indigestion, in addition to catarrhal and nervous symptoms. Further, in factories where chlorine is produced by the electrolytic process, workers were found to be suffering from the so-called chlorine rash (first observed by Herxheimer). This skin disease consists in an inflammation of the glands of the skin, with occasional development of ulcers and scars. Severe cases are accompanied by digestive disturbance. Bettmann, Lehmann, and others maintain that it is not caused by chlorine alone, but by chlorinated tar products, which are formed in the production of chlorine and hydrochloric acid. In acute cases of chlorine poisoning oxygen treatment should be tried, but in any case the patient should have free access to pure air. Approved remedies are inhalation of soda spray or very dilute ammonia, or of a vapourised solution of sodium hypochlorite. If the patient is in great pain, he may be allowed to inhale cocaine solution (0·2 per cent.). The administration of arsenic (solutio arsenicalis) is recommended, especially in cases of acne. In general the usual treatment for diseases of the skin is followed; salicylic acid lotions, sulphur baths, and sulphur ointments may be made use of. =Chlorides.=—_Chlorides of Phosphorus_, _Phosphorus-trichloride_ (PCl₃), and _Phosphorus oxychloride_ (POCl₃), are strong-smelling liquids, fuming in the air, and when brought into contact with water decomposing into phosphorous acid and hydrochloric acid. These halogen compounds of phosphorus have a violently irritant action upon the respiratory organs and the eyes, in that they decompose on the mucous membrane into hydrochloric acid and an oxyacid of phosphorus. Inhalation of the fumes of these compounds causes cough, difficulty of breathing, inflammation of the respiratory passages, and blood-stained expectoration. Treatment is similar to that for acid poisoning in general and hydrochloric acid in particular. Similar to that of the chlorides of phosphorus is the action of _chlorides of sulphur_, of which _sulphur monochloride_ (S₂Cl)₂ is of industrial hygienic importance as it is employed in the vulcanising of indiarubber. It is a brown, oily, fuming liquid, which, mixed with water or even in damp air, decomposes into sulphur dioxide and hydrochloric acid. The fumes of sulphur monochloride have therefore a marked irritant effect, like that of hydrochloric acid and sulphur dioxide. The action of sulphur chloride was thoroughly studied by Lehmann. Industrial poisoning by sulphur chloride is mentioned by Leymann and also in the reports of the Prussian factory inspectors for 1897. The latter case ended fatally owing to the ignorance of the would-be rescuers: a workman had spilt trichloride of phosphorus upon his clothes, and the by-standers, not knowing its dangerous action when combined with water, poured water on him. Treatment is similar to that of poisoning from hydrochloric acid or sulphur dioxide. _Chloride of zinc_ (zinc chloride, ZnCl₂) likewise has corroding and irritant action upon the mucous membrane of the respiratory organs. AMMONIA Ammonia (NH₃) is a colourless, pungent-smelling gas which dissolves to the extent of about 33 per cent. in water. Inhaled, it first produces violent reflex coughing, then irritation and corrosion of the mucous membrane of the respiratory organs, and finally death through suffocation (spasm of the glottis) if exposure to its action has lasted a sufficiently long time. Microscopic sections exhibit a diphtheritic appearance of the mucous membrane, and inflammation of the lungs. The effects upon the central nervous system (irritation of the medulla and spinal cord) which are peculiar to ammonia compounds need not be considered, as the corrosion of the respiratory passage is sufficient alone to cause death. When the action of the gas is less intense, the patient rallies from the first stage, but often severe symptoms come on later affecting the lungs. Lehmann in experiments upon himself could tolerate as much as 0·33 per thousand NH₃ for thirty minutes; he found in gas works (with fairly marked odour) hardly more than 0·1 per thousand NH₃ in the atmosphere, and considers 0·5 per thousand distinct evidence of excess. He found that he could produce in dogs acclimatisation up to 1·0 per thousand NH₃ (five times as much as could at first be borne). About 88 per cent. of the ammonia contained in the air is absorbed in breathing; ammonia is said to exercise also a reducing action upon the oxygen of the blood (oxyhæmoglobin). Chronic poisoning by ammonia can hardly be said to occur. In those who clean out sewers and drains, the inflammation of the eyes and digestive disturbance attributed partly to ammonia are probably due more to the action of sulphur compounds—ammonium sulphide and sulphuretted hydrogen. Irritation due to solution of ammonia does not come into account in industrial employment. As regards treatment, fresh air or administration of oxygen is most likely to be successful. Inhalation also of very dilute acetic acid vapour, steam, or spray of sodium carbonate is advocated. ALKALIS The alkaline hydroxides (potassium and sodium hydroxide, KOH, NaOH) have an albumen-dissolving and therefore caustic effect. Industrially it occurs in the caustic action of concentrated (often hot) lyes upon the skin or upon the eye—through splashing. Quicklime (CaO) has also a caustic action, producing inflammation of the skin or eyes (especially in those engaged in the preparation of mortar). Under this head comes also the effect upon the respiratory passages—described by several authors—caused in the production of artificial manure discussed at length in Part I. As regards treatment of the irritant effect of alkalis, what has been said as to corrosives in general applies here (rinsing with water or weak organic acids), and in inflammation of the eye caused by lime a drop of castor oil is recommended. _GROUP: METALS AND METAL-COMPOUNDS_ The various substances of this group differ markedly in their action. Under this heading come principally chronic metal poisonings, characterised by a general, often very intense, disturbance of nutrition, which justifies their delineation as ‘metabolic poisons’; among these poisons also are included certain others which produce chronic poisoning accompanied by severe disturbance of the peripheral and central nervous system. The corrosive action common to the metal oxides (when acting in a concentrated condition), attributable to the formation of insoluble albuminates, need not, in industrial poisoning, be taken so much into account. The corrosive effect is characteristic only of the compounds, especially of the acid salts of chromium, which, as an acid-forming element, may be classed in the preceding group. Disturbance of health in workmen handling nickel compounds are also ascribed to the corrosive action of these substances. LEAD, LEAD COMPOUNDS Lead poisoning is the most frequent and important chronic industrial poisoning; the symptoms are very varied and associated with the most different groups of organs. We shall describe the typical course of a case of industrial lead poisoning, laying stress, however, on the fact that numerous cases follow an irregular course, in that special symptoms or complications of symptoms are in some especially accentuated, while in others they become less marked or are absent altogether. A premonitory indication of chronic lead poisoning is a blue line on the gum, indicated by a slate gray or bluish black edging to the teeth, the appearance of which is usually accompanied by an unpleasant sweetish taste in the mouth. The cause of this blue line was for some time disputed. It is obviously due to the formation and deposit of sulphide of lead through the action of sulphuretted hydrogen arising from decomposition in the mouth cavity. At the same time a general feeling of malaise and weakness often comes on, occasionally accompanied by tremor of the muscles and disinclination for food, at which stage the sufferer consults the doctor. Frequently he complains also of pains in the stomach, not difficult to distinguish from the lead colic to be described later. Usually the patient already exhibits at this stage general emaciation and marked pallor. The blue line was formerly considered a characteristic early indication of lead poisoning; but it has now been proved that occasionally it is absent even in severe attacks. But although the blue line may fail as an ‘initial symptom,’ it will nevertheless be a valuable aid to the practitioner in the recognition of lead poisoning. It is worth while to mention the fact that other metallic poisons produce a very similar ‘line,’ especially mercury, also iron and silver (as in the case of argyria); it has been stated that the blue line can be simulated by particles of charcoal on the gum. The pallor of the patient at the commencement of lead poisoning drew attention to the condition of the blood. The diminution in the amount of hæmoglobin often met with, which under certain circumstances is accompanied by diminution of the red blood cells, offers nothing characteristic. On the other hand, structural changes in the red blood cells—presence of basophil granules in them—are asserted by a number of writers to be characteristic of the first stages of lead poisoning. The basophil granules are believed to be due to regenerative changes in the nucleus. But these changes are also found in pernicious anæmia, cancer, leucæmia, anæmia, tuberculosis, &c.; also in a number of poisonings such as phenylhydrazine, dinitrobenzene, corrosive sublimate, and others; they are therefore the less characteristic of chronic lead poisoning, as occasionally they cannot be found in actual lead poisoning, a point upon which I have convinced myself in the case both of men and animals. Still, the appearance of much basophilia in the red blood cells is a valuable aid to diagnosis, especially as the method of staining to demonstrate them is simple. Other anomalies of the blood observed in lead poisoning may here be mentioned. Glibert found a striking diminution in the elasticity of the red blood corpuscles, and experiments I have made point to the fact that the power of resistance of the red blood corpuscles to chemically acting hæmolytic agents, such as decinormal soda solution, is considerably reduced. The pulse is generally hard and of high tension, especially during the attacks of colic. Further, cramp of the bloodvessels (also in the retinal arteries) has been observed. To these functional disturbances in the circulation are added sometimes definite changes in the vessel wall. Later, obliterative arteritis comes on (in the brain arteries), and arteriosclerosis. The most important symptom of fully developed lead poisoning is colic, which is usually preceded by the initial symptoms described (especially the gastric symptoms), but not always so, as occasionally colic sets in without any warning. The colic pains often set in with marked vehemence. They radiate from the navel on all sides, even through the whole body; the abdomen is contracted and as hard as a board. Pressure on the lower part diminishes the pain somewhat, so that the sufferer often involuntarily lies flat on his stomach. During the attack the pulse is often remarkably slow. Constipation occurs, and often does not yield to purgatives. The attacks last sometimes for hours, occasionally for days, or the pains can (with remissions) even distress the patient for weeks. The frequency of attacks is also very variable. Occasionally one attack follows another, often there are intervals of weeks, even years, according to the severity of the poisoning and duration of exposure. If the patient is removed from the injurious action of lead, as a rule recovery soon ensues. [Illustration: FIG. 34.—Paralysis of the Ulnar Nerve in Lead Poisoning] [Illustration: FIG. 34A.—Different Types of Paralysis of the Radial Nerve in Hungarian Potters poisoned by Lead (_after Chyzer_)] Often with the colic, or at any rate shortly after it, appear lead tremor and arthralgia, paroxysmal pain mostly affecting the joints, but occasionally also the muscles and bones. They are often the precursor of severe nervous symptoms which affect the peripheral and central nervous system. In a lead poisoning case running a typical course the predominant feature is the peripheral motor paralysis of the extensors of the forearms. Next the muscles supplied by the radial and ulnar nerves are affected. Often the progress of the paralysis is typical; it begins with paralysis of the extensor digitorum communis, passes on to the remaining extensors, then to the abductor muscles of the hand; the supinator longus and triceps escape. Sometimes the shoulder muscles are attacked; also paralysis in the region supplied by the facial nerve and of the lower extremities is observed. It appears plausible that overstrain of single groups of muscles plays a decisive part; this seems proved by the fact that paralysis first affects, among right-handed people, the right hand (especially of painters), but in the case of left-handed, the left hand; and among children the lower extremities are often attacked first. Disturbance of sight increasing to amaurosis is often an indication of severe brain symptoms. The view of some writers that the cause of the sight disturbance lies in vasomotor influences (cramp of the bloodvessels) is very probable, and supports the view that the brain symptoms are entirely due to diseases of the arteries (arteritis). These symptoms are distinguished by the collective name of saturnine encephalopathy; they include apoplexy, hemiplegia, epilepsy, delirium, and mania. The brain symptoms may cause death. As later symptoms of lead poisoning may be mentioned lead gout and kidney disease (lead nephritis). The genesis of both these diseases is much disputed. It seems to be proved that the gout is true gout (with presence of tophi) and that the contracted kidney is indistinguishable from ordinary chronic Bright’s disease. The kidney symptoms suggest that a regular excretion of lead through the urine takes place which, if it were a fact, would have been an important aid to diagnosis. But often analysis of urine for presence of lead is negative. Excretion of lead by the skin is scarcely to be credited, although occasionally affirmed. Elimination of lead is effected mainly through the intestines (probably for the most part as sulphide of lead). All lead compounds more or less are to be regarded as poisonous, although the intensity of the action depends on the amount absorbed. For this its solubility in water or in weak acids (hydrochloric acid of the gastric juice) is the simplest test. According to this acetate of lead, lead chloride, carbonate of lead (white lead), oxide of lead (lead dross), minium (red oxide of lead) are relatively the most poisonous. Lead sulphate and lead iodide are to be regarded as relatively less poisonous, although by no means innocuous. The least poisonous, if not altogether innocuous, is sulphide of lead, because it is an insoluble lead compound. Treatment of lead poisoning ought to aim first and foremost at the elimination of lead from the body. But unfortunately such attempts have had little success. Treatment of symptoms is all that for the most part is possible. Administration of iodide of potassium to assist the excretion of lead has not been found the success which many anticipated. This remedy however, can be tried; better results are to be expected from careful regulation of the bowels by means of purgatives. During colic administration of opium or morphia may be advisable to relieve pain and overcome the probable cramp of the intestinal muscles. The cautious administration of atropine (occasionally with cocaine) also serves the same purpose. Hot compresses and mustard plasters may be applied, and liquid diet should be given. Lead cachexia must be treated by strengthening diet. Electrical treatment for lead paralysis is advocated. From baths (sulphur baths) nothing more is to be expected than a bracing effect—elimination of lead through increased diaphoresis is hardly to be hoped for. ZINC (ZINC ALLOYS) Zinc (Zn) melts at 412° C. and distills at about 900° C.; exposed to the air it burns, when heated, into zinc oxide. Older writers, when investigating gastric and intestinal diseases and affections of the nervous system observed in zinc smelters, regarded them as the result of chronic zinc poisoning; but it may now be accepted as certain that these symptoms are due to the lead always present in the zinc. On the other hand so-called _brass-founders’ ague_ may be regarded as a form of acute industrial zinc poisoning. Brass-founders’ ague occurs exclusively in brass casters, and not in zinc workers. Sigel and Lehmann have shown that founders’ ague is also caused by pure zinc if this is heated so strongly that it burns. Premonitory symptoms often occur before the onset of the disease; usually they appear early, soon after casting has begun. The workman has general malaise accompanied by slight cough, nausea, throat irritation, &c., but these symptoms mostly disappear, returning again after a few hours with renewed violence, often in the evening before going to bed. Frequently, trembling sets in rather suddenly, often accompanied by headache, nausea, and muscular pains, and soon develops into a pronounced shivering fit, lasting generally about a quarter of an hour, but in severe cases for several hours (with intervals). At the same time the breathing is hurried and the heart’s action quickened (asthma and palpitation). Often the temperature rises as high as 104° F. The attack ends with profuse perspiration, and the patient sinks exhausted to sleep, awaking in the morning generally quite restored or with but slight signs of fatigue; only rarely is he unable to resume work. It is noteworthy that some workmen are extraordinarily susceptible to brass-founders’ ague, and are attacked again and again, while others remain completely immune, so that idiosyncrasy and immunity both play a part. Workmen who are susceptible to the disease, yet without marked disposition (idiosyncrasy) towards it, can become acclimatised to the poison. Lehmann has succeeded in artificially producing an attack in a brass-caster who was highly susceptible. The symptoms in him were the result of work with pure zinc in a burning condition. The proof, therefore, is clear that brass-founders’ ague is due to zinc, and not, as some authors have supposed, to copper or the simultaneous action of both metals. The symptoms are produced through inhalation of zinc oxide, not zinc fumes. Lehmann conjectures that brass-founders’ ague may be a secondary fever due to absorption into the system of the remains of cells in the respiratory tract that have been killed by the action of the zinc. The treatment can only be symptomatic; as the attack is so transient, medical attendance is hardly necessary. MERCURY, MERCURY COMPOUNDS Mercury (Hg), on account of its volatility, is classed among industrial poisons. Although boiling at 360° C. it is volatile even at ordinary temperature. Industrial mercurial poisoning is caused by the frequent inhalation of small quantities of vapour, sometimes, but more rarely, of dust containing mercury, and assumes usually a chronic form. Industrial mercurial poisoning often begins with inflammation of the mucous membrane of the mouth and gums. There is increased flow of saliva, a disagreeable metallic taste in the mouth, and foul breath. This may be limited to a simple inflammation of the gum, or go on to ulceration with falling out of teeth, or even to gangrene of the gum and mucous membrane inside the mouth. Gastric attacks also occur in the early stages; occasionally, however, they are absent. The main symptoms of chronic mercurial poisoning are nervous and psychical derangement, to which in severe cases are added general disturbance of digestion and loss of strength. Sometimes, after repeated attacks, more or less severe, a cachectic condition is induced, showing itself in general emaciation, decrease of strength, atrophy of the muscles, anæmia, and disturbed digestion, which—often intensified by some intercurrent disease, such as tuberculosis—lead to death. Slight cases of mercurialism recover, leaving no evil results, if the patient is removed in time from the influence of the poison. The treatment of chronic mercury poisoning is symptomatic. To allay the inflammation of the mucous membrane of the mouth the patient should use a mouth wash of potassium chlorate and peroxide of hydrogen; the general condition should be raised by strengthening, unstimulating food; for the nervous symptoms baths and electricity should be tried; and for very marked erythism and tremor recourse to narcotics may be necessary. Industrial mercurial poisoning is produced not only by metallic mercury but also by many compounds, of which industrially the oxides are the most important. Nitrate of mercury (Hg₂(NO₃)₂) comes into account in the treatment of fur. Mercury cyanide (HgCy₂) deserves mention, as small quantities cause mercurial and large quantities cyanogen poisoning. MANGANESE, MANGANESE COMPOUNDS Manganese (Mn) or manganese compounds are used industrially in fine powder; continuous absorption of dust containing manganese produces chronic manganese poisoning. Instances of such poisoning are not very numerous; altogether about twenty cases have been described. Recent publications agree in asserting that only the dust rich in manganese protoxide is dangerous. Industrial manganese poisoning runs its course extraordinarily slowly, and resembles chronic poisoning by other heavy metals, such as lead and mercury, in that nervous and psychical symptoms, rather than digestive, are prominent. Sometimes—but not always—the disease is introduced or accompanied by psychical symptoms, both of excitement and depression (hilarity, laughing, or depression and weeping). In the course of the disease nervous disturbances arise, deafness, tingling, paralysis and paræsthesia, in the arms and legs, giddiness, difficulty of walking, tremor, increased knee-jerks and difficulty in speech. Often at the same time swelling of the lower extremities (œdema) and loss of strength (cachexia, marasmus) come on. Slight cases make a good recovery. An interesting case of illness is described by Jaksch as manganophobia, in which the symptoms were simulated, and were brought on solely by the fear of manganese poisoning. As regards treatment, electricity, massage, and baths are advocated to allay the nervous symptoms, as in the case of chronic metal poisoning and suitable strengthening food. CHROMIUM, CHROME COMPOUNDS Chromium trioxide (CrO₃) dissolves in water, forming chromic acid (H₂CrO₄); of the salts of chromic acid the neutral and acid alkaline salts concern our inquiry. These are normal and acid sodium or potassium chromate (K₂CrO₄ and K₂Cr₂O₇). Chromate of lead (PbCrO₄) can cause lead poisoning. Poisoning can be produced by dust and by alkaline chromates, the latter, when hot, giving off steam which, as has been proved, contains excessively fine chrome particles. Chrome compounds attack especially the surface of the body, the skin and the mucous membrane. The bichromate and chromate dust produce ulcers where slight injuries to the skin already exist. The ulcers develop slowly, and have a smooth, heaped-up, undermined edge; deep-seated, they can even pierce to the bone; they heal with great difficulty. Naturally they occur most frequently on the uncovered parts of the body, especially on the arms and hands. Characteristic also is an analogous ulceration attacking the mucous membrane of the nose, from which hardly any chrome worker (especially if brought into contact with chromate dust) is free. Perforation and destruction of the cartilaginous septum of the nose is very common. Ulcers on the mucous membrane at the entrance of the throat (on tonsils and palate or in the larynx) have been occasionally observed. Absorption of small quantities of chrome compounds into the body are said to cause disturbances of digestion of an inflammatory character, and especially inflammation of the kidneys. The treatment of chrome ulcers is similar to that of other chronic ulcers. An antidote for industrial chrome poisoning is not known. OTHER METALS AND METAL COMPOUNDS =Nickel Salts.=—Of late years in nickel-plating establishments an eczematous inflammation of the skin has been described affecting first of all the hands, and occasionally spreading over the arms and even the whole body. The skin becomes inflamed, and vesicles appear on the affected part. Some persons are extraordinarily susceptible to this disease, others only become so after having worked for years quite unaffected, and are then obliged to give up their occupation. Probably the action of nickel salts (especially nickel sulphate) used in electrolytic baths causes the disease. But it was in fact traced by several writers to contact with benzene, petroleum, and lime by the workmen. The simultaneous action of these substances upon the skin would no doubt encourage its appearance. The application to the skin of vaseline or cream is recommended. Careful cleanliness and attention to the skin is on the whole by far the most reliable protection. [=Nickel carbonyl= (Ni(CO)₄).—Mond, Langer, and Quincke in 1890 discovered that, on passing a current of carbon monoxide over finely divided (pyrophoric) metallic nickel, a gaseous compound of nickel and carbon monoxide was formed. When heated to 150° C. the gas decomposes into its constituents and metallic nickel is deposited. Nickel carbonyl is a clear, pale straw-coloured liquid, volatilising at room temperature. It has a peculiar soot-like smell detectable when present to the extent of about 1 vol. in 2,000,000, while the Bunsen flame becomes luminous when nickel carbonyl is present in the air to the extent of 1 vol. in 400,000—two facts of great importance in detecting escape of the gas in the manufacture of pure nickel by the Mond process. _Occurrence of poisoning by nickel carbonyl._—At the first introduction of the process about 1902, before the dangerous properties of the gas had been sufficiently recognised, some twenty-five men were poisoned, of whom three died. Poisoning only occurred when, as a result of the breakdown of the automatic working of the plant, hand labour took the place of machinery. This very rare form of poisoning has been very fully investigated by H. W. Armit (_Journ. of Hygiene_, 1907, p. 526, and 1908, p. 565). The symptoms in man, he says, were transient headache and giddiness and at times dyspnœa, quickly passing off on removal to fresh air. After from twelve to thirty-six hours the dyspnœa returned, cyanosis appeared, and the temperature began to be raised. Cough with more or less blood-stained sputum appeared on the second day. The pulse rate became increased, but not in proportion to the respiratory rate. The heart remained normal. Delirium of varying types frequently occurred. Death took place in the fatal cases between the fourth and eleventh days. The chief changes found post mortem were hæmorrhages in the lungs, œdema of the lungs, and hæmorrhages in the white matter of the brain, while some doubt exists as to whether any blood changes were present. Precisely analogous results were found in experiments on animals (rabbits, cats, and dogs). The points Armit investigated experimentally were (1) Is the carbon monoxide of the compound wholly or partly responsible for the symptoms, or (2), is nickel carbonyl absorbed as such, or (3), is it the nickel of the compound which produces the symptoms? His conclusions are that the poisonous effects of nickel carbonyl are entirely due to the nickel of the compound. The peculiar toxicity is due to the fact that, being introduced in a gaseous form, the nickel is deposited as a slightly soluble compound in a very fine state of subdivision over the immense area of the respiratory surface. Nickel carbonyl when mixed with air cannot be absorbed as such by an animal as it becomes split up into the nickel containing substance (possibly hydrated basic carbonate of nickel) and carbon monoxide before or soon after reaching the alveoli of the lungs. The nickel is dissolved from the respiratory surface by the tissue fluids and is then taken up by the blood. The hæmorrhages found after death follow as the result of fatty degeneration of the vessel walls which is the specific pathological change set up by nickel.] =Copper.=—Symptoms which have been described by some writers as chronic industrial copper poisoning are probably due to admixtures of other poisonous metals, especially lead and arsenic. Although some copper workers, especially those careless of cleanliness, exhibit hair and teeth coloured by the action of copper compounds (green tinge on hair and edge of teeth), symptoms of illness traceable to copper are not demonstrable. _Brass-founders’ fever_, which by some earlier writers was ascribed to copper or combined copper and zinc action, is traceable to zinc (see Zinc). =Ferro-silicon.=—The illnesses due to this are phosphoretted or arseniuretted hydrogen poisoning (see pp. 191 and 197). =Silver and Silver Compounds.=—Gradual absorption of small quantities of a solution of silver may produce industrial argyria, often beginning with the appearance of a black edge to the gums and darkening of the hair and nails, followed by black spots on the skin which in severe cases coalesce, so that the whole or almost the whole surface of the body becomes black and glossy. Argyria is due to the absorption of silver compounds into the circulation, and subsequent deposition of the reduced silver in the body (liver, kidneys, spinal cord, &c.). The black colouring of the skin is caused by the action of light. No interference with health worth mentioning is observed. _GROUP: ARSENIC, PHOSPHORUS_ The poisons (gradually absorbed) belonging to this group are mainly such as affect metabolism; they impair the processes essential to metabolism (in especial the oxidation processes) and cause severe damage to the cells, through destruction of albumen. The poisons of this group also have a paralysing effect upon the central nervous system. Generally speaking the effects produced by the poisons of this group vary considerably. Among the arsenic compounds arseniuretted hydrogen, which is supremely a blood poison, must be excluded from the group and included among the blood poisons. ARSENIC, OXIDES OF ARSENIC Pure _metallic arsenic_ (As) is considered innocuous. _Oxides of arsenic_ especially are held to be industrial poisons such as arsenic trioxide (As₂O₃), the anhydride of arsenious acid (H₃AsO₃), a white powder, which is known under the name of white arsenic; _arsenic acid_ (H₃AsO₄), which forms crystals easily soluble in water, and the salts of these acids, especially copper arsenite, formerly employed in the production of dyes, and also _arsenic chloride_ (arsenic trichloride, AsCl₃). _Arseniuretted hydrogen_ will be treated separately as it has a completely different poisonous effect from that of the oxidic compounds of arsenic. _Arsenic sulphides_ (realgar, AsS₂, and orpiment, AsS₃) are regarded as innocuous in consequence of their insolubility in a pure state. But it may be remarked that arsenic sulphides (sulphur arsenic ores) which are used industrially, and even metallic arsenic, are to be considered poisonous, as they contain oxidic arsenic compounds in great quantity. Chronic arsenical poisoning is caused by gradual absorption through the respiratory or digestive tracts of small quantities of the oxidic arsenic compounds either in solution or as dust or fumes. The disease usually begins with digestive derangement which shows itself in more or less severe gastric and intestinal catarrh (loss of appetite, vomiting and diarrhœa); sometimes there are severe affections of the respiratory tract,—pharyngeal and bronchial catarrhs; often the illness is accompanied by skin affections of various kinds, rashes, pustular eczema, loosening of the nails, abscesses, dark pigmentation of particular parts of the skin, and other symptoms. The nervous symptoms vary much according to the severity of the disease; first of all, deafness and feeling of pins and needles, or loss of sensation (paræsthesia and anæsthesia) of the extremities. Further, rheumatic joint pains, weakness of the extremities and characteristic symptoms of paralysis occur, with accompanying atrophy of the muscles, and gradual loss of energy leading to total incapacity for work. Severe cases end in general exhaustion and loss of strength, with signs of severe injury to the central nervous system, such as epileptic fits, mental hebetude, &c. PHOSPHORUS _Phosphorus_ (P) is polymorphic; red (amorphous) phosphorus is innocuous, while white or yellow is poisonous. Phosphorus at various stages of oxidation is little if at all poisonous. White phosphorus is volatile and fumes in the air—the fumes consisting of phosphorus, phosphoric and phosphorous acids. Chronic industrial phosphorus poisoning is produced by continued inhalation of the fumes of white phosphorus resulting in inflammation of the periosteum of the bone, with which necrosis and formation of new bone are associated. It attacks especially the lower jawbone (ossifying periostitis). The inflammation begins with increased flow of saliva, painful swelling of the gums, which, as it increases, brings about the death of the jawbone (necrosis, phosphorus necrosis). This becomes covered again with newly formed bone substance from the periosteum. The process ends with the formation of a fistula (a passage filled with pus), which discharges outwards, and through which the dead bone (sequestrum) is eventually cast off. Occasionally the process attacks the upper jaw, rarely other bones. With these characteristic symptoms of phosphorus necrosis, derangement of nutrition together with anæmia, indigestion and bronchial catarrh, may be associated. Further, a general brittleness of the bones (fragilitas ossium) is observed with the result that the long bones of the leg or arm sometimes break at relatively small exertion of force; such cases from Bohemia came lately under my notice. Some authorities regard caries of the teeth as the pre-disposing cause of phosphorus necrosis; according to this view the carious teeth constitute the means of entrance for the poison. Opposed to this so-called ‘local’ theory is the view that chronic phosphorus poisoning is a ‘general’ one. The truth may lie midway. On the one hand phosphorus necrosis probably arises partly from the general poisonous action of the phosphorus, and on the other from local inflammation which leads to the occurrence of local symptoms. The general symptoms of chronic phosphorus poisoning described above support this view, especially the effect observed on the bones of the skeleton. This view is also strengthened by the fact that workmen with perfectly sound teeth, who had been exposed to phosphorus fumes for many years, were attacked by necrosis only when traumatic inflammation produced by chance injury was set up. The treatment of phosphorus necrosis is surgical. Formerly the treatment recommended was to wait for formation of new bone and exfoliation of the dead bone (expectant treatment); the necrosed portions of bone were then extracted through the fistula. Recently early operative interference has succeeded in preserving the periosteum which enabled the new bone to form. Phosphoretted Hydrogen Industrial poisoning by gaseous phosphoretted hydrogen (PH₃) calls for attention in connection with the preparation and employment of calcium carbide (acetylene) and also of ferro-silicon. Phosphoretted hydrogen is a dangerous poison. Even 0·025 per cent. in the air is harmful to animals after a time; 0·2 per cent. PH₃ in the air quickly causes death. The poison produces changes in the lungs, though without injuring the respiratory passages by corrosion, and finally has a paralysing effect upon the central nervous system. It has no effect upon the blood. An autopsy on a person who has died of phosphoretted hydrogen poisoning reveals as a rule no characteristic sign, except centres of inflammation in the lungs. The symptoms of phosphoretted hydrogen poisoning are—difficulty of breathing, cough, fainting fits, noises in the ears, and nausea; in severe cases coma and death. Slight cases soon recover without after-effects. _GROUP: SULPHURETTED HYDROGEN, CARBON BISULPHIDE, AND CYANOGEN (NERVE POISONS)_ In this group are comprised industrial poisons the principal effect of which is upon the nervous system, especially the central nervous system. The chemical composition of the separate members of the group differs much. SULPHURETTED HYDROGEN Industrial poisoning by pure sulphuretted hydrogen (SH₂), the well-known colourless, nauseous-smelling gas, occurs comparatively rarely. Poisoning is generally acute, but chronic illness in workers has been traced back to inhalation of the gas. This poison exerts a paralysing action upon the central nervous system and is slightly irritating to the mucous membranes and respiratory organs. Its action can be described as follows: When absorbed into the blood union of the poison with the alkaline constituents takes place with formation of an alkaline sulphide. Presence of only slight quantities of sulphuretted hydrogen in the air acts injuriously. Lehmann has shown that about 0·15 to 0·2 per thousand sulphuretted hydrogen is not without effect, and that prolonged inhalation of 0·5 per thousand becomes dangerous. Continued exposure to the poison seems only to increase susceptibility to its action. An almost complete absorption of the whole of the sulphuretted hydrogen present in the air breathed takes place. Continued inhalation of small quantities of sulphuretted hydrogen produces irritation of the mucous membrane, cough, and lacrymation; headache, giddiness, nausea, and mental dulness soon ensue; occasionally also symptoms of intestinal catarrh follow; if at this stage—or after a longer exposure to the action of a smaller amount—the patient is withdrawn from its further influence, there still continue for some time symptoms of irritation of the mucous membrane (such as inflammation of the conjunctiva and of the respiratory passages). Further exposure or absorption of greater amounts induces general discomfort and passes on to a second stage of convulsions and delirium. Inhalation of a large dose of sulphuretted hydrogen causes almost instantaneous death; the affected person falls dead—often without a sound—as if struck by a blow; occasionally a short stage of unconsciousness, with symptoms of suffocation, precede death. This acute form often occurs, especially in acute sewer gas poisoning. Besides this, a sub-acute form of sewer gas poisoning is recognised which is attributable, in part at least, to the action of sulphuretted hydrogen, the prominent symptoms being irritation of the mucous membranes and of the intestinal canal. In other severe cases symptoms of the central nervous system preponderate (headache, giddiness, and delirium). These forms of poisoning can be caused not only by sulphuretted hydrogen, but also by other poisonous gases which are found in drains or sewers. As regards treatment, continued inhalation of oxygen, supported by artificial respiration, is often, in serious cases, effective. In severe poisonings also saline injections and bleeding may be advocated. Other symptoms (catarrh, &c.) must be treated symptomatically. CARBON BISULPHIDE Pure carbon bisulphide (CS₂) is a colourless, peculiar-smelling liquid which boils at 46° C. As Lehmann has shown, even 1·5 to 3·0 mg. CS₂ per litre of air produces distress—with acute symptoms of poisoning (congestion, giddiness, sickness, &c.). Industrial carbon bisulphide poisoning is, however, chronic in nature and induced by continuous inhalation of small quantities of the fumes. To understand the action of carbon bisulphide, its capacity for dissolving fats and fatty substances must be taken into account. Its injurious effect extends to the nerve tissues (central and peripheral nervous system) and the glandular tissues. Throughout chronic industrial carbon bisulphide poisoning, which has been described fully by Delpech, Laudenheimer, and others, nervous and psychical symptoms predominate, together with severe chronic digestive derangement. The patient after exposure for some time suffers from violent headache, giddiness, and sickness; he has sensations of cold, pains in the limbs, a feeling of ‘needles and pins,’ and itching in different parts of the body. Gradually a condition of general excitement develops. Sleeplessness, cramps, and palpitation set in. At the same time the nervous system becomes involved—hypersensitiveness, loss of sensation or complete numbness of some parts of the skin, diminution of muscular power, disturbances of movement, twitching, violent trembling, wasting of the muscles, and paralysis; the sight also is sometimes affected. The stage of excitement, in which the patient often becomes strikingly loquacious without cause, passes gradually, as the nervous symptoms develop, into the stage of depression; sometimes this takes weeks and months; excitement and gaiety give place to deep depression; other symptoms appear—weakness of memory, mental dulness, and difficulty in speaking. The powers of sensation become affected, paralysis increases, and digestive disturbances, anæmia, and general loss of strength are manifest. Occasionally definite mental disease (psychosis, mania, melancholia, dementia, &c.) develops. Certain cases of chronic carbon bisulphide poisoning in indiarubber workers have come under my notice, and some remarks concerning them may be of interest. The characteristic symptoms are essentially as follows: the invalid appears in the consulting-room in a bent position, leaning upon a stick with head and hands shaking. The gait is clumsy (spastic-paralysis) so that the patient ‘steps’ rather than walks. When seated, the tremor ceases to some extent, but in purposive movements increases rapidly, involving the whole body, so that an exact systematic examination becomes impossible, and the invalid sinks back into the chair exhausted and bathed in perspiration. He complains of cold in the extremities. He looks pale; the skin of the upper extremities is totally without feeling, as also is the upper part of the feet; the skin of the head is hypersensitive; the muscular strength of the arms is almost lost; testing the strength brings on marked shaking, followed by a fainting-fit caused by exhaustion. The extremities of the patient are cyanotic (livid); the knee jerks are exaggerated. The patient suffers from indigestion, constipation, headache, and giddiness; he is irritable, and depressed; his memory is weak; mental derangement cannot be proved. Chronic carbon bisulphide poisoning is rarely fatal. Slight cases end in recovery after more or less long continuance; in severe cases improvement occasionally takes place, but serious nervous disturbance (paralysis, weakness of the muscles, deterioration of intellect) usually persists. Treatment is symptomatic, aiming especially at relieving the nervous symptoms and improving the state of nutrition. If psychical disturbances are prominent, treatment in an institution is necessary. CYANOGEN AND CYANOGEN COMPOUNDS (CYANOGEN GAS, PRUSSIC ACID, CYANIDES) Industrial cyanogen poisoning is not frequent. _Cyanogen gas_ (C₂N₂, existing in small quantities in furnace gas, illuminating gas, and other kinds of gas) and especially _hydrocyanic acid_ (CNH, prussic acid) are considered industrial poisons; the latter is a very unstable, colourless, pungent-smelling liquid, boiling at 27° C. Among the cyanides employed industrially and having an effect similar to that of prussic acid must be mentioned _cyanide of potassium_ and _cyanide of sodium_ (KCN and NaCN), _cyanide of silver_ (AgCN) and _cyanide of mercury_ (Hg[CN]₂). Cyanogen and cyanogen compounds are extraordinarily powerful poisons. The minimum dose lies, as Lehmann has proved by experiments on animals, at about 0·05 per thousand of hydrocyanic acid in the atmosphere breathed; 1-5 mg. per kg. weight is fatal to animals; to man about 60 mg. would be fatal. The poisonous action of cyanogen and cyanogen compounds depends upon their power of preventing absorption of oxygen from the blood by the tissues with the result that the venous blood flowing to the heart retains the bright red colour which otherwise only arterial blood exhibits. This effect is due to cessation of the gaseous exchange in the body, and results in tissue suffocation. At the same time these poisons have at first an exciting and then a paralysing effect upon the central nervous system. In severe poisoning the nerve effect is masked by the effect upon the exchange of gases in the blood, since this quickly leads to death. Most of the cases of industrial poisoning under this heading result from inhalation; absorption of liquid cyanogen compounds through the skin can rarely come into consideration. If large quantities of hydrocyanic acid have been inhaled, death ensues very quickly. The person affected falls down suddenly, breathes with difficulty, the pulse soon becomes imperceptible, and after a more or less long stage of deep unconsciousness (coma) life becomes extinct. In slight cases of poisoning the patient feels a sensation of irritation in the throat, giddiness, sickness, and difficulty in breathing; occasionally such disturbances persist for some time. Some writers have described symptoms in workers manipulating prussic acid and cyanides, which they believe to be due to chronic prussic acid poisoning. Complaint is made of oppression of the chest, throat irritation, giddiness, difficulty in breathing, palpitation, hebetude, exhaustion, and nausea and vomiting; in certain instances the attack, aggravated by exhaustion and weakness, culminates in death. It is a question whether such poisonings are chronic in the true sense of the word. In view of the mode of action of hydrocyanic acid, such cases of sickness should rather be accounted acute or sub-acute poisonings through repeated action of small quantities of the poison. It may be mentioned that in persons working with alkaline cyanides (especially in electro-plating) skin affections occasionally occur; these are traceable to the caustic effect of alkaline cyanides. Treatment by oxygen inhalation with simultaneous artificial respiration holds out most prospect of success. This holds good for acute poisoning by the other poisons belonging to this group. Besides this, saline injections and bleeding are recommended, and also the administration of an infusion of sodium thiosulphate solution. _GROUP: ARSENIURETTED HYDROGEN AND CARBONIC OXIDE (BLOOD POISONS)_ Included in this group, as in the former one, are substances chemically very different from each other, but of which the action is especially on the blood. Besides this common effect, these substances also produce various other effects, such as local irritation, effect on the nervous system, &c. The industrial blood poisons, which according to their chemical constitution are classed among the aliphatic and the aromatic series of organic compounds, will, for the sake of clearness, be discussed in the following chapters. ARSENIURETTED HYDROGEN Acute arseniuretted hydrogen poisoning, produced by inhalation of relatively very small quantities of arseniuretted hydrogen gas (AsH₃) is in most cases industrial in origin. The absorption of an amount corresponding to about 0·01 mg. arsenic suffices to produce severe poisoning symptoms. The poisonous effect results chiefly from action upon the red blood corpuscles, which are dissolved (hæmolysis). Arseniuretted hydrogen is therefore a genuine blood poison. The effect upon the blood, if not immediately fatal to life, is to cause the dissolved blood-colouring matter to pass into the tissues where, though some is deposited, most goes to, and acts injuriously on, the organs, especially the liver, spleen, and kidneys. In cases running at once a fatal course, the impoverishment of the blood caused by the lack of colouring matter necessary to internal respiration produces tissue suffocation, which is therefore the primary cause of death. In cases not immediately fatal, the injury to the functions of the organs alluded to (for instance, cessation of the functions of the kidneys, &c.) may lead to death secondarily. Symptoms of the disease appear often only some time after the poisoning has set in, and begin with general malaise, sickness, collapse, fainting fits, and difficulty of breathing; after some hours the characteristic signs follow—the urine becomes dark red to black, containing quantities of blood colouring matter and dissolved constituents of the blood, and later also bile colouring matter, so that a coppery jaundice comes on if the illness is prolonged. The region of the liver, spleen, and kidneys is painful. Severe cases often end fatally during the first stage of the illness, more rarely later, with increased difficulty of breathing; sometimes death occurs after a preceding comatose stage marked by convulsions and delirium. In slighter poisoning cases the symptoms abate in a few days and recovery follows. The treatment of arseniuretted hydrogen poisoning is similar to that adopted in the case of all other blood poisonings: in addition, if possible, direct transfusion of blood from the artery of the giver into the vein of the receiver, liquid nourishment, saline injections, and, above all, prolonged oxygen inhalation. CARBONIC OXIDE (CO) Carbonic oxide (CO) is a colourless, odourless gas which frequently causes both acute and, it is said, chronic industrial poisoning. Carbonic oxide is a very poisonous gas; even as little as 0·5 per thousand in the atmosphere breathed has a poisonous effect; about 2-3 per thousand can be dangerous to life. Its poisonous effect results from its power of combining with the blood-colouring matter or hæmoglobin to form carboxy-hæmoglobin; the affinity of carbonic oxide for the hæmoglobin of the blood is more than 200 times greater than that of oxygen, so that, however small the amount of carbonic oxide in the air, it is inevitably absorbed by the blood and retained. The blood so altered, assumes a cherry-red colour, is unable to effect the necessary exchange of gases for internal respiration, and in consequence of the lack of oxygen suffocation ensues. Without doubt, however, carbonic oxide has also an immediate effect upon the central nervous system (first excitation, followed quickly by paralysis). It is maintained also that besides the action upon the hæmoglobin it favours coagulation of the blood through the disintegration of the blood corpuscles. The last-mentioned action is thought to account for the sequelæ of carbonic oxide poisoning, but they can also naturally be accounted for by the direct effect of the poison. Onset of symptoms is very sudden if a large quantity of pure carbonic oxide is inhaled. The affected person immediately falls down unconscious and succumbs after drawing a few breaths with difficulty. In less acute cases the illness begins with premonitory symptoms, generally headache, sickness, giddiness, sleepiness, though in cases of fairly rapid absorption these are absent, and are naturally absent also when the poisoning creeps upon the affected persons while asleep, as occasionally happens in cabins, &c., in factories. If the poisoning continues, increasing mental dulness, accompanied by nausea and vomiting, leads sometimes to a short stage of seemingly drunken excitement, which preludes deep unconsciousness during which there is often a convulsive stage, followed by complete loss both of sensation and of reflex action; the breathing becomes shallow and intermittent, the pulse small and irregular, and finally death ensues. Occasionally in the stage of unconsciousness, death is hastened by entrance of vomited matter into the respiratory passages. Bright red patches are seen on the body after death. If persons affected by severe carbonic oxide poisoning are withdrawn from the poisonous atmosphere after having reached the stage of unconsciousness, they may recover, but often with difficulty; not infrequently—in spite of suitable treatment—death occurs some considerable time later from the symptoms described above. Still, in many cases, under the influence of right treatment, gradual recovery has been brought about, even after long unconsciousness accompanied by repeated convulsions. In the rescued the symptoms described as characteristic of the first stage often continue for at least a day. Further, they are liable to a number of serious after effects, such as severe inflammation of the lungs due to infection by the entrance of vomited matter into the air passages, skin affections (rashes), and especially severe nervous and mental affections. Frequently these develop from centres of softening in the brain or from inflammation of the peripheral nerves (neuritis); occasionally the poisoning may really only be the predisposing cause for the outbreak of an existing psychical disease. It is not our task to enumerate all the extremely varied disturbances which are observed after carbonic acid gas poisoning. Neuralgias and paralyses have been described as associated with the peripheral nerve symptoms over areas supplied by different nerves; various forms of diseases of the brain and spinal cord (poliomyelitis, paralysis, sclerosis, &c.); and finally a series of psychoses (neurasthenia, melancholia, mania, &c.), occasionally passing into dementia and imbecility. Glycosuria (sugar in the urine) has also been noted as a sequela. Chronic carbonic oxide poisoning, arising from continued inhalation of small quantities of the gas, sets in usually with symptoms similar to those of acute carbonic oxide poisoning; if the worker continues exposed to danger, severe symptoms may arise which point to marked alteration of the blood and later also of the digestion and bodily functions. Under certain circumstances severe nervous and mental affections are said to occur similar to those which we have mentioned as sequelæ of acute carbonic oxide poisoning (convulsions, disturbances of mental activity, symptoms which resemble progressive muscular atrophy, &c.). In acute carbonic oxide poisoning oxygen inhalation indefatigably continued and supported by artificial respiration is often successful. The serious danger from this form of poisoning renders it very necessary that in all premises where there is risk provision should be made for the administration of oxygen. The sequelæ can of course only be treated symptomatically. OXYCHLORIDE OF CARBON (PHOSGENE) Oxychloride of carbon (COCl₂), also called phosgene, is, at the ordinary temperature, a colourless gas with a disagreeable smell. This decomposes in moist air into carbonic oxide, hydrochloric acid, or chlorine, and produces a strongly irritant local effect upon the mucous membranes. Industrial poisoning by phosgene is characterised by great difficulty in breathing and inflammation of the respiratory tract (bronchitis and bloodstained expectoration). Several cases have been treated successfully by oxygen inhalation. NICKEL CARBONYL The effects of nickel carbonyl are described on pp. 186-8. CARBONIC ACID Carbonic acid (CO₂), a colourless gas, is heavier than air (specific weight, 1·526), and therefore, wherever it collects, sinks to the ground. Carbonic acid is only very slightly poisonous; about 10 per cent. carbonic acid in the air causes asphyxia. The extinguishing of a candle flame will serve as an indication that the amount of carbonic acid in the atmosphere has reached this point. Cases of industrial carbonic acid asphyxia are sudden; they do not occur frequently. The gradual action of the gas when mixed with air produces first a tingling sensation on the surface of the body, reddening of the face, irritation of the mucous membrane and the respiratory organs, after which succeed difficulty in breathing, palpitation, fainting, and unconsciousness. Sudden and fatal poisoning occurs industrially. Upon entering places filled with carbonic acid gas the affected person falls down dead almost immediately. These are cases of asphyxia, in which the lack of oxygen certainly plays the greatest part. If those affected by acute carbonic acid poisoning are removed in time out of the dangerous atmosphere they usually recover quickly. Oxygen inhalations and artificial respiration are to be applied in severer cases. There are no sequelæ. _GROUP: HYDROCARBONS OF THE ALIPHATIC AND AROMATIC SERIES AND THEIR HALOGEN AND HYDROXYL SUBSTITUTION PRODUCTS_ The industrial poisons comprised in this group have as their principal general effect injurious action upon the functions of the central nervous system (paralysis or causing excitation) which is prominent in most of the cases of industrial poisoning caused by these substances. This effect is most marked in the case of the readily volatile (low boiling) hydrocarbons, while those less volatile and boiling at a higher temperature often have collateral effects (such as local irritation). The characteristic poisonous effect caused by the chlorine and hydroxyl-substitution products (chloroform and alcohol group) is also mainly on the central nervous system (narcosis). HYDROCARBONS OF MINERAL OIL BENZINE, LIGROINE, PETROLEUM, PARAFFIN, VASELINE _Mineral oil_ (crude petroleum) has, according to its origin, differing composition. Thus in American mineral oil hydrocarbons of the methane series preponderate; in the Russian, hydrocarbons of the aromatic series. Reference has been made in Part I. to this point, as well as to the separation of crude petroleum into its different fractions. The injury to health produced by crude petroleum and its derivatives is of two kinds. Direct contact with liquid petroleum and the semi-liquid and solid deposit after distillation (paraffin) cause local injury to the skin. Inhalation of the volatile constituents of raw petroleum causes symptoms affecting mainly the central nervous system. They have moreover a markedly irritating effect upon the mucous membrane of the respiratory organs. These substances clearly exhibit the characteristic we have referred to, namely, that the hydrocarbons boiling at low temperature act as nerve poisons, whereas those boiling at a higher temperature produce a local irritant effect. The skin affections take the form of inflammation of the hair follicles (acne), eruptions with characteristic formation of vesicles, and pimples and pustules which precede the deep-seated formation of ulcers, abscesses, &c. In paraffin workers the acne-like skin inflammations are known as ‘paraffin eczema.’ They develop sometimes into cancer of the skin (warty and epitheliomatous growths). In the general poisoning produced by inhalation of petroleum fumes the effect upon the central nervous system is all the more plainly and clearly marked when the irritant effect of the hydrocarbons boiling at higher temperature is slight or absent; that is, in the case of poisoning which arises solely from industrial products of low boiling hydrocarbons; among these benzine is included. Acute poisoning from inhalation of benzine fumes begins with headache, sickness, and attacks of giddiness resembling alcoholic intoxication. If very much has been inhaled, the patient quickly becomes unconscious, with occasionally muscular tremors, convulsions, difficulty in breathing, and cyanosis. In cases of poisoning by inhalation of fumes of crude petroleum, these symptoms may be complicated by coughing, intense inflammation of the mucous membrane of the respiratory organs—congestion, bronchitis, bloodstained expectoration, and inflammation of the lungs. In workers who frequently remain long in an atmosphere filled with benzine fumes, further symptoms of chronic benzine poisoning show themselves—mental hebetude, pains in the limbs, trembling, weakness of the muscles, and other disturbances of the nervous system; in such cases these may really be signs of continued attacks of acute or sub-acute poisoning; many benzine workers are anæmic. The treatment of acute benzine poisoning consists in oxygen inhalation, with simultaneous artificial respiration. Treatment of chronic derangement of health is symptomatic. HYDROCARBONS OF THE AROMATIC SERIES BENZENE AND ITS HOMOLOGUES _Benzene_ (C₆H₆) is a characteristically smelling (aromatic) liquid which boils at 80·5° C. Acute benzene poisoning, which plays an important part as an industrial poisoning, is caused by inhalation of benzene fumes. The various kinds of benzol used commercially contain, besides benzene, alkyl benzenes, especially _toluene_ (methylbenzene, C₆H₅.CH₃, boiling-point 111° C.); _xylene_ (dimethylbenzene, C₆H₄[CH₃]₂, boiling-point 140° C.); _pseudocumene_ and _mesitylene_ (tri-methylbenzene, C₆H₃[CH₃]₃, boiling-point 169° or 163° C.); the regular presence of _thiophene_ (C₄H₄S, boiling-point 84° C.) in commercial benzol must also be taken into account. Industrial benzol poisoning arises, therefore, as a rule, not from the action of pure benzene vapour, but from fumes which contain a mixture of the compounds mentioned. The course run by industrial benzol poisoning is often very acute, if large quantities are inhaled—death occurring suddenly, after a short illness with symptoms of vertigo. Gradual inhalation of lesser quantities gives rise to headache, giddiness, malaise, then twitchings appear which develop into convulsions, and lastly unconsciousness. In order to ascertain in what manner the various substances contained in commercial benzol share in the poisonous effect, experimental research seemed to me to be indispensable, especially as published statements so far gave no accurate data. Two cases of industrial benzol poisoning have given rise to close experimental research upon the poisonous nature of benzene. Lewin undertook experiments on animals; which he confined under bells and caused to inhale fumes of chemically pure and impure benzene. He mentions that even at comparatively low concentration poisoning results, and indeed more readily and certainly from the action of impure than pure benzene. Lewin found that when air was made to flow slowly first through benzene and then into the bell, symptoms of paralysis, convulsions, and unconsciousness showed themselves in from four to six minutes. After-effects by this means could not be observed. Lewin maintains, however, that in man even slight acute action of benzene can be followed by after-effects (giddiness, sickness, headache, distress in breathing, and oppression of the heart). Santesson made researches upon the poisonous action of benzene in connection with occurrence of certain cases of poisoning through ‘impure benzol’ (coal-tar benzene) in a rubber tyre factory. In the factory mentioned nine young women were poisoned, of whom four died. The symptoms shown were lassitude, anæmia, giddiness, headache, vomiting, and fever. Post mortem, hæmorrhages and fatty degeneration of the endothelium of the bloodvessels and various organs were found. Experimental research showed that commercial benzol and chemically pure benzene had the same effect. Santesson did not succeed in his experiments on animals in producing chronic poisoning by inhalation of benzine and of benzene fumes (which two completely different poisons he does not distinguish strictly from each other, as is the case, unfortunately, with many other writers). My experimental researches upon the poisonous effect of pure benzene, pure toluene, cumene, thiophene, and the most important kinds of commercial benzol gave the following results: For rabbits the limit of toxicity is a proportion of 0·015 to 0·016 per thousand pure benzene in the air, that is 0·015 to 0·016 c.c. benzene vapour per litre of air. A concentration of 0·056-0·057 per thousand pure benzene in the air causes in rabbits at once—after one minute—twitching of the muscles; after eight minutes, convulsions; after ten minutes, deep narcosis; and after twenty-five minutes, coma. If the animal is taken out of the bell in time, even if it has shown marked symptoms, it recovers very quickly (in two to ten minutes) without manifesting any after effects. Even in animals repeatedly exposed to the poison sequelæ were not observed. Dogs are somewhat more susceptible to pure benzene than rabbits; 0·024 per thousand causes after ten minutes severe convulsions, which after twenty minutes become continuous; 0·042 per thousand kills after twenty minutes (sudden death in a state of tetanus). Cats are less sensitive than dogs and more sensitive than rabbits; 0·03-0·04 per thousand causes after ten minutes attacks of cramp and, after twenty minutes, convulsions; 0·05 per thousand at once brings on poisoning symptoms. As regards the character of the symptoms (cramps, convulsions, quick recovery, no after effects) the above statements apply to all three kinds of animals (rabbit, dog, and cat). Chloral hydrate completely checks the convulsions and enables animals to tolerate higher concentrations of benzene for a longer time. Benzene is thus to be counted among nerve irritant poisons. The convulsions are probably provoked by excitement of the motor centres in the brain. In view of the fact that thiophene in a concentration of 0·03-0·05 per thousand in the air was borne by animals for an hour without producing any symptoms of poisoning, the proportion of thiophene in commercial benzol must be looked upon as practically non-injurious. The so-called 90 _benzol_—a commercial benzol of which 90 per cent. distils at 100° C.—has naturally a somewhat weaker action, although, in respect of the poisoning symptoms produced, it is similar to that of pure benzene. _Pure toluene_ (boiling-point 111° C.) and purified toluol (commercial product, boiling-point 109°-112° C.) produce, when inhaled, gradually increasing narcosis in the three kinds of animals referred to; they produce no symptoms of convulsions or spasms. After the animals have been taken out of the bell, recovery is not so rapid as after benzine inhalation, but takes from half an hour to one hour. In rabbits and cats 0·046-0·05 per thousand produces after fifteen minutes staggering and paresis; after thirty minutes deep narcosis. The dog is again somewhat more susceptible, as little as 0·034 per thousand causing these symptoms in the same time. ‘Purified toluol’ (commercial product) acts somewhat less rapidly than pure toluene, but this small difference in effect need hardly be considered. Other poisons were also investigated:— _Solvent naphtha I_, a commercial product, of which 90 per cent. comes over at 160° C.; it contains little toluene, chiefly xylene, pseudocumene, and cumene. _Solvent naphtha II_, of which 90 per cent. comes over at 175° C, it contains besides xylene, chiefly pseudocumene, mesitylene, cumene, &c. The fumes of solvent naphtha I cause, when inhaled by rabbits, dogs, and cats, gradual narcosis, although not nearly so quickly as toluene at similar concentrations; recovery usually takes over an hour after the deeply narcotised animals have been removed from the bell. Rabbits and cats are affected in about equal degree. The dog is the more sensitive. Rabbits and cats can tolerate about 0·012-0·013 per thousand of the fumes of solvent naphtha I in the atmosphere for a long time without any symptoms. Only after breathing for fifty minutes air containing 0·0536 per thousand do they become narcotised. In the dog 0·036 per thousand causes narcosis only after thirty minutes. With the fumes of solvent naphtha II I could not affect rabbits at all. The cat also, in spite of long inhalation of the heavy fumes, showed no marked symptoms of poisoning. In the dog gradual narcosis came about only after an hour’s inhalation of 0·048 per thousand. The fumes of pure _xylene_ caused narcosis in rabbits after forty minutes’ inhalation of 0·05 per thousand in the atmosphere; after being taken out of the bell the animals recovered slowly (after half an hour to one hour). _Cumene_ causes no symptoms after one hour’s inhalation in a concentration of 0·06 to 0·07 per thousand. This explains the effects of solvent naphtha I (in which xylene preponderates) and solvent naphtha II (in which pseudocumene, cumene, &c., preponderate). After effects were not observed. Benzol and toluol fumes, and particularly those of solvent naphtha, exercise a distinctly irritant effect upon the mucous membrane, which, however, passes off without after effects. Pure benzene, therefore, proved the most poisonous of the substances under investigation. When inhaled its effect (convulsions, with quick recovery) differs essentially from that of toluene, solvent naphtha, xylene, and cumene (gradual narcosis, slow recovery). The fumes of the various kinds of commercial benzol (solvent naphtha) boiling at a higher temperature are practically non-poisonous (solvent naphtha II). Pure benzene fumes are, however poisonous, even in very small quantities in the air. The limit for animals lies at 0·015-0·016 per thousand. Lehmann has shown in a recent work that man, exposed to a mixture of benzene and air, absorbs 80 per cent. of the benzene. Treatment of acute industrial benzene poisoning consists in severe cases of artificial respiration, with simultaneous administration of oxygen; in slight cases it is sufficient to bring the patient into fresh air. _Naphthalene._—Naphthalene, which is insoluble in water, has irritant effect upon the mucous membrane and upon the skin when brought into contact with it. Long continuance in an atmosphere containing naphthalene as dust or fumes causes headache, nausea, giddiness, &c. HALOGEN SUBSTITUTION PRODUCTS ALIPHATIC SERIES (NARCOTIC POISONS) The halogen substitution products of the aliphatic series are not of much account as industrial poisons. They have generally a narcotic effect, that is, a paralysing effect upon the central nervous system, usually preceded by a short stage of excitement. This effect shows itself typically on inhalation of chloroform (methanetrichloride, CHCl₃), which however plays no part as an industrial poison. The narcotic effect of the other alkyl chlorides is less than that of chloroform. With carbon tetrachloride (CCl₄) the narcotic effect is only half that of chloroform; it causes, however, a more violent excitation; inhaling the fumes brings on nausea, coughing, sickness, headache, &c. _Methylchloride_ (CH₃Cl) has a less narcotising effect. On the other hand it has a stronger local irritant action, which is indeed present also in chloroform, though not so apparent. This gas, as is well known, is used as a local anæsthetic in medicine. Pure _methylene chloride_ (CH₂Cl₂) similarly is much less powerful than chloroform. Severe poisoning, alleged to have resulted from methylene chloride was caused by a mixture, called indeed methylene chloride, but composed of methylalcohol and chloroform. Of the remaining halogen substitution products of methane, _methyl bromide_ (CH₃Br) and _methyl iodide_ (CH₃I) have given rise to industrial poisoning. These poisons also act in the same way as the alkyl chlorides, but the excitement accompanying the narcosis is more marked—so far as the scanty observations allow conclusions to be drawn. The symptoms first show themselves in sickness, giddiness, hebetude, slowing of respiratory movements and of the heart’s action; convulsions or delirium ensue. Treatment consists in artificial respiration or promotion of breathing by a plentiful supply of fresh air or oxygen; in pronounced narcosis stimulating remedies should be applied. BENZENE SERIES _Chlorobenzene_, and _nitro-_ and _dinitro-chlorobenzene_ and _benzoylchloride_, have given rise to industrial poisoning. To chlorobenzene similar action is attributed as to benzene (headache, fainting, rapid breathing, cyanosis); changes in the blood (methæmoglobin formation) have also been observed. Nitro- and dinitro-chlorobenzene are active poisons; the effect corresponds in general to that of nitro- and dinitrobenzene, but in addition the fumes or dust have markedly irritant action on the skin (dermatitis). _Benzoylchloride_ (C₆H₅COCl), a colourless, pungent-smelling liquid, produces a violently irritant effect upon the mucous membrane, decomposing into hydrochloric acid and benzoic acid. Treatment is analogous to that of benzene poisoning, and in cases of benzoyl chloride poisoning to that by hydrochloric acid. It may be mentioned that chlorine rash is attributed to the action of chlorinated tar products (chlorobenzene compounds). HYDROXYL SUBSTITUTION PRODUCTS FATTY SERIES (ALCOHOLS) The hydroxyl substitution products of the fatty series belong mainly to the narcotic poisons; the greater the molecular weight of the alcohol, the more marked is usually the narcotic effect. According to this propylalcohol is eighteen times as poisonous as ethylalcohol; butylalcohol and amylalcohol have from 36 to 120 times as great a narcotic effect as methylalcohol. _Methylalcohol_ (wood spirit, CH₃OH) plays relatively the greatest part among alcohols as an industrial poison, because it is employed as a means of denaturing spirit. Its poisonous nature is relatively great, being very persistent. Industrial poisoning by methylalcohol is due to inhalation of the vapour and is rarely of a severe nature. The fumes have a strongly irritant effect upon the mucous membrane, giving rise to throat irritation, cough, hoarseness, and in severe cases bronchitis and inflammation of the conjunctiva of the eye. In addition inhalation of methylalcohol vapour causes headache, giddiness, nausea (inclination to vomit), and occasionally also twitchings and tremor. The _higher alcohols_ (propyl-, butyl-, amyl-alcohol, C₃H₇.OH, C₄H₉.OH, and C₅H₁₁.OH) occur in fusel oil. They cause but slight (if any) industrial poisoning. Cases of more severe industrial poisoning through amylalcohol fumes have been described (in factories for smokeless powder), with symptoms of sickness, headache, giddiness, with fatal issue in some cases, preceded by severe nervous symptoms (convulsions or delirium). Beyond speedy removal out of the dangerous atmosphere, probably no special treatment is needed in these cases of industrial poisoning from alcoholic vapour. _GROUP: NITRO AND AMIDO COMPOUNDS OF THE ALIPHATIC AND AROMATIC SERIES (BLOOD POISONS WHICH FORM METHÆMOGLOBIN)_ Characteristic of the nitro and amido compounds of the aliphatic and aromatic series of the organic substances is their action upon the blood. The normal oxyhæmoglobin (blood-colouring matter) is changed into methæmoglobin, with which the oxygen is so firmly combined that the internal exchange of gases necessary to life becomes impossible. Methæmoglobin has a dark chocolate-brown colour and a clearly defined characteristic spectrum. Of the poisons belonging to this group several are important. In so far as these substances are volatile—and this is generally the case with those causing industrial poisoning—effects are due to inhalation of fumes, but it is proved that the poisons of this group in liquid form can be absorbed by the intact skin, and this channel of absorption is characteristic of industrial poisoning. Severe poisoning results especially from wetting the skin by spilling on the clothes, &c. The grey-blue discoloration of the mucous membrane, especially of the lips, is characteristic; sometimes also the skin is altered in colour. This discoloration is often noticed by others before the patient feels unwell. Soon the person affected has general nausea, vomiting, headache, giddiness, severe nervous symptoms, feeling of anxiety, and difficulty of breathing; in severe cases unconsciousness comes on, and death occurs with increasing cyanosis (lividity). Treatment is naturally that which has been emphasised in the introductory words to Part II, which hold for all blood poisonings. In mild cases oxygen treatment has given good results. In all factories where such poisoning can occur provision should be made for immediate oxygen treatment. Besides this, the workers must be adequately instructed as to the danger and symptoms of poisoning, especially of the characteristic premonitory skin discoloration, in order to be able to assist their fellows. NITROCOMPOUNDS ALIPHATIC SERIES _Nitro-glycerin_ (triple nitric acid ester of glycerin, C₃H₅.[NO₃]₃), the well-known oily explosive liquid, has also an irritant local effect. When absorbed into the body, in addition to methæmoglobin formation, it causes dilatation of the bloodvessels, slowing of the respiration and heart’s action, and attacks of suffocation. The general remarks upon this group apply here, but symptoms referable to central paralysis occur as the methæmoglobin formation is slow. Industrial poisoning arises through inhalation of gases containing nitro-glycerin and also by absorption through the skin. Statements as to its poisonous nature are very varied. Under certain conditions moistening the skin with small quantities of nitro-glycerin suffices to produce symptoms. Probably the susceptibility of different persons varies greatly. _Amylnitrite_ (nitric acid amyl ester, C₅H₁₁NO₂), a characteristically smelling liquid, acts similarly. The fumes of amylnitrite, even when inhaled in small quantities, cause marked dilatation of the bloodvessels, through paralysis of the muscular walls of the bloodvessels, thus causing marked flushing of the face; the pulse becomes quick, then weak and slow. NITRO AND AMIDO COMPOUNDS AROMATIC SERIES The substances of this group are important. _Nitrobenzene_ (C₆H₅NO₂, named oil of mirbane), a yellowish liquid of characteristic smell, induces especially the formation of methæmoglobin in the blood; the effect upon the central nervous system (first excitation, then depression) is often absent. The description of the disease in general in the introductory words of this whole group is characteristic. Occasionally signs of asphyxia show themselves; sometimes there are twitchings, disturbance of the power of sensation, and convulsions; early discoloration of the mucous membrane and the skin, which assume a blue to grey-black colour, is characteristic. Chronic poisoning is also attributed to nitrobenzene, showing itself in lassitude, headache, malaise, giddiness, and other disturbances of the nervous system. _Nitrotoluene_ (C₆H₄CH₃NO₂), of which the ortho-compound acts most powerfully, and also _nitroxylene_ (C₆H₃[CH₃]₂NO₂) have similar but less marked effect. The _dinitrobenzenes_ (C₆H₄[NO₂]₂) are stable bodies. Meta-dinitrobenzene inhaled as dust or otherwise, can produce marked poisoning symptoms essentially the same as those described. Especially characteristic is the early dark discoloration of the skin. Symptoms resembling nitrobenzene poisoning in general are caused by _nitrophenols_ (C₆H₄.OH.NO₂), of which paranitrophenol is the most toxic; also by _dinitrophenols_ (C₆H₃[NO₂]₂OH), solid crystalline substances which melt at different temperatures, and the _mono-_ and _di-nitrochlorobenzenes_ (C₆H₄.Cl.NO₂ and C₆H₃.Cl[NO₂]₂). In cases of industrial poisoning by dinitrophenol, observed by Leymann, the workers were taken suddenly ill, with symptoms of collapse, pains in the chest, vomiting, distress of breathing, rapid pulse, and convulsions, and died within a few hours. At the autopsy a yellow substance was found with picric acid reaction which appeared to be di- or tri-nitrophenol. In other cases, some fatal, of industrial nitrochlorobenzene poisoning, also observed by Leymann, the typical grey-blue discoloration of the skin was obvious, and the chocolate-brown colour of the blood produced by methæmoglobin. _Trinitrophenol_ (picric acid, C₆H₂[NO₂]₃OH) is a yellow crystalline compound with bitter taste; poisoning by this substance exhibits clearly strong local irritant action (upon skin, mucous membrane, and intestinal canal, and especially upon the kidneys), besides effect on the blood and central nervous system. Prolonged action of picric acid upon the skin causes inflammation. Absorption of picric acid dust causes inflammation of the mucous membrane of the respiratory passages and symptoms of gastric and intestinal catarrh as well as inflammation of the kidneys. A jaundice-like discoloration of the skin and darkening of the urine are also characteristic; sometimes picric acid poisoning produces a rash resembling that of measles and scarlet fever. _Nitronaphthalene_ (C₁₀H₇[NO₂]) and _nitronaphthol_ (C₁₀H₆.NO₂.OH) in addition to methæmoglobin formation have an irritant action. It is stated also that dulness of the cornea is produced. _Azobenzenes_ also, which are to be considered as intermediate between nitrobenzene and aniline, form methæmoglobin (azobenzene, C₆H₅N = NH₅C₆). _Aniline_ (amidobenzene, C₆H₅.NH₂), a colourless, oily liquid of aromatic smell, has only slight local irritant effect. In the frequent cases of industrial poisoning by ‘aniline oil’ or aniline hydrochloride, in which the aniline enters through the skin or is inhaled in the form of fume, there appear the typical symptoms common to this group, of the action upon the blood through methæmoglobin formation: headache, weakness, cyanosis, difficulty in breathing, &c., to which are added nervous symptoms such as convulsions and psychical disturbance, although these play a subordinate part in industrial poisoning. In severe cases the typical symptoms of air hunger are shown. Occasionally recovery only takes place gradually, and signs of irritation of the kidneys and inflammation of the urinary organs are seen. These symptoms occur only rarely in acute industrial poisoning, but are, however, in so far worthy of notice because of the frequent occurrence of tumours in the bladder among aniline workers. It is possible that here the irritant action of the urine which contains aniline plays a part. The tumours in the bladder operated upon, in some cases with success, were many of them non-malignant (papillomata), but some were carcinomata (cancerous new growths) running a malignant course, and recurring after operation. In the urine the aniline combines with sulphuric acid, and is partly excreted as paramidophenol sulphuric acid. The treatment of aniline poisoning is the same as that for all the poisons of this group. In view of the occurrence of tumours of the bladder in aniline workers, they should be instructed to seek medical aid on the first indications of trouble, so that a careful cystoscopic examination may be made. _Toluidine_ (C₆H₄.CH₃.NH₂), which is mixed with aniline for industrial use, produces the same symptoms with marked irritation of the renal organs. Of the _nitroanilines_ (C₆H₄.NH₂.NO₂) _paranitroaniline_ is the most poisonous. Characteristic of the action of this compound is methæmoglobin formation, central paralysis and paralysis of the heart’s action. Of the _benzenediamines_, _paraphenylene diamine_ (C₆H₄[NH₂]₂) may be regarded as an industrial poison. The irritant action of this substance is prominent; it induces skin affections, inflammation of the mucous membranes, more especially of the respiratory organs, and sometimes inflammation of the kidneys. They have been noted in workers using ursol as a dye; here, doubtless, the action of diimine (C₆H₄.NH.NH.) must be taken into account, which arises as an intermediate product and exercises a markedly irritant action. Further, the general effect of paraphenylene diamine is an irritant one upon the central nervous system. _APPENDIX_ TURPENTINE, PYRIDINE BASES, ALKALOIDS _Turpentine oil._.—Turpentine oil is a peculiar-smelling, colourless liquid of the composition C₁₀H₁₆; different reactions show that turpentine oil contains the aromatic nucleus (cymene). It is used in the manufacture of varnish, and thus can cause industrial poisoning by inhalation of fumes. Even from 3 to 4 mg. of vapour of turpentine oil per litre of air brings on severe symptoms. Turpentine oil acts as a local irritant, and when absorbed into the system has an exciting effect upon the central nervous system. Inhalation of large quantities of turpentine vapour cause rapid breathing, palpitation, giddiness, stupor, convulsions, and other nervous disturbances, pains in the chest, bronchitis, and inflammation of the kidneys. The last-mentioned symptom also arises from the chronic action of turpentine vapours. _Pyridine._—Pyridine (C₅H₅N), a colourless liquid of peculiar odour, is employed as well as methylalcohol in denaturing alcohol. The disturbance of health observed in workers occupied with the denatured spirit are probably mainly due to the inhalation of fumes of methylalcohol. Pyridine is comparatively innocuous. Eczema, from which persons suffer who come into contact with denatured spirit, is ascribed to the action of pyridine. Larger doses produce a paralysing effect, but this need not be considered in its industrial use. _Nicotine, tobacco._—According to various published statements, effects among tobacco factory workers are attributed to the nicotine contained in tobacco dust and to the aroma which fills the air. Nicotine in large doses has at first an exciting followed by a paralysing effect upon the central nervous system; it causes moreover contraction of the unstriped muscles and has a local irritant effect. The symptoms of illness ascribed to nicotine are: conjunctivitis, catarrh of the air passages, palpitation, headache, want of appetite, and, particularly, tendency to abortion and excessive menstruation. Severe industrial poisoning due to nicotine has only been observed in workers who chewed tobacco leaves. _Poisonous wood._—The symptoms of disease noticed in workers who manipulate certain kinds of wood are attributed by some writers to the presence of alkaloids. Such knowledge as we have of the illness due to them—they are evidently of the nature of poisoning—is referred to at the end of Part I. PART III _PREVENTIVE MEASURES AGAINST INDUSTRIAL POISONING_ _GENERAL MEASURES_ In discussing preventive measures against industrial poisoning the deductive method from the general to the particular will be followed. The numerous instances of poisoning mentioned in Part I afford a practical basis on which to formulate general rules before passing on to describe special measures. Technical details will be omitted, as they must be left to the technical expert whose business it is to draw up the plans as a whole and to modify them according to the requirements of individual cases. In the effort to control industrial poisoning and disease it is necessary to insist absolutely on the concerted action of all concerned. In this co-operation every one is called who through his knowledge and sphere of activity is in a position to assist. The medical man comes in with his special knowledge of the action of poisons as toxicologist, as practising physician (especially as works surgeon and doctor of the sick insurance society), and also in an official capacity as appointed surgeon or medical officer of health; the technical expert comes in as engineer, as manager, as foreman, and as factory inspector. But above all the interest and active co-operation of employers and employed are needed as well as the organisations of both. That the workers should understand and co-operate is essential for the success of preventive measures, and subsequently it will be shown in what direction this co-operation is most necessary. To make possible such co-operation interest must be aroused and suitable information and teaching supplied to the parties concerned. Medical men and practical workers require to receive instruction in industrial hygiene, and teaching on this subject should be arranged for in secondary and technical schools. Medical men and others who, as officials and insurance doctors, are brought constantly into touch with industrial workers should have opportunity—by means of special courses and lectures—to keep pace with advancing knowledge in this direction. Beside these there are, as educative organisations, special Institutes of Industrial Hygiene and special hospitals for treatment of diseases of occupation which bring together the patients and the teaching staff and so facilitate pursuit of knowledge and research. A beginning of this kind has already been made by the Industrial Hygiene Institute, Frankfurt a.-Main, and the hospital for diseases of occupation at Milan, showing that the ideas are attainable. International agencies which unite all circles interested in the subject irrespective of profession or nationality in common interchange of thought and discussion are of great significance for uniform development of needful preventive measures; international congresses, often in connection with exhibitions, have given valuable stimulus and have been the starting-point of permanent international societies, unions, and organisations. The significance for our inquiry of these international efforts will be more closely considered in the following pages. II _GENERAL CONSIDERATIONS ON SOCIAL AND LEGISLATIVE MEASURES_ INTERNATIONAL PREVENTIVE MEASURES, NOTIFICATION OF INDUSTRIAL POISONING, LISTS AND SCHEDULES OF INDUSTRIAL POISONS Experience and inquiry in the field of industrial poisoning led to a series of demands which, supported as they were by a general movement for the protection of workers, were soon followed by regulations and legislative action. For a long time efforts have been directed to treat industrial disease and poisoning in the same way as has been done in the case of industrial accidents. The question, however, is attended with much greater difficulty. On the other hand, uniform international regulation of questions affecting prevention of disease is called for both on humanitarian and economic grounds. The idea of international legislation for the protection of workers was first mooted about the year 1870. The possibility and need of such intervention was much discussed and interest in it kept constantly alive, especially in Switzerland, until the organisations of the workers took up the idea. Several attempts failed. In France in 1883 a proposal of the Socialist party aiming at international agreement on the subject of protection of the workers was rejected. In 1885 (in opposition to Hertling) Prince Bismarck expressed himself strongly against the possibility of such international protection. But the stone, once set rolling, could not be stayed. In the years 1886, 1887, and 1888 the French and English trade unions, as well as the Swiss Federal Council, took up the question afresh. These endeavours at last took tangible shape in the first International Conference for the protection of workers held in Berlin in March 1890. This date remains a landmark in the history of the subject, but not until ten years later—1900—did the Congress held in Paris for the international legal protection of workers lead to the establishment of what had been repeatedly urged, namely, creation of an International Bureau. This was inaugurated at Basle in 1901 and forms the headquarters of the National Associations for Labour Legislation called into being in various countries. This International Association meets regularly in conference, as in Cologne (1902), Berne (1905), Lucerne (1908), Lugano (1910), and Zurich (1912). The questions raised in the International Labour Bureau, which receives financial aid from a number of States, are fully and scientifically discussed with the object of finding a basis on which to bring into agreement the divergent laws of the different countries. A further task of this strictly scientific institution is the collection and publication of literature bearing on the protection of workers in one and another country, distribution of information, and the editing of reports and memoranda. The question of prevention of industrial poisoning has always taken a foremost place in the programme of the International Association and in the agenda of the International Labour Bureau. At its first meeting a resolution was adopted advocating the prohibition of the use of white phosphorus and white lead, and the Labour Bureau in Basle was instructed to take the necessary steps. Special, if not prohibitive, economical considerations foreshadowed difficulties—all the greater because the matter at issue concerned prohibition of articles playing a part in the markets of the world. Just on that account international treatment of such questions is necessary, since a peaceful and orderly solution can only be arrived at on such lines. International effort endeavours here to press with equal weight on the countries competing with one another commercially, so that in the protection of the workers economic adjustment is sought in order that efforts based on humanitarian grounds shall not at the same time cause economic disadvantages, the aim being to produce general welfare and not merely protection of one class at the expense of another. Through these international agreements between various countries success in the direction aimed at is hopeful, and indeed to a certain extent—as in the phosphorus and lead questions—actually attained. Thus, for example, Germany and Italy were in a position to enforce prohibition of the use of white phosphorus early, while their neighbour Austria, on account of commercial and political considerations and the conditions of the home lucifer match industry, has only recently decided on prohibition. As international agreement for the protection of workers is advisable on economic grounds, so also is it reasonable and just from purely humanitarian reasons that workers, without reference to civil condition or nationality, should be equally protected. On this point it is proposed to take a vote and to press only for those reforms which are thoroughly sound and recognised as necessary. The first step in such a comprehensive attack is precise knowledge of the extent and source of origin of the particular forms of industrial poisoning and disease and the collection of reliable statistics. This suggested the obligation to notify such cases to the proper authorities in the same way as is now done in the case of infectious disease. A motion to this effect had already been passed at the Conference of the International Association for Labour Legislation held in Basle, and a request was made to the Labour Bureau to prepare a list of the diseases and poisonings in question. To them we shall refer later, but a schedule is necessary as a basis to work upon. Yet even when this is done there are obviously great difficulties to be overcome in carrying out the requirement of notification when the aim is kept in mind of collecting complete statistical data for controlling the conditions giving rise to industrial disease. The proposal of the International Association seeks to make notification obligatory on the part both of the medical practitioner in attendance and the occupier, and in connection with this to secure the co-operation of the Sick Insurance Society.[D] The proposal to require the appointed surgeons and surgeons of the Insurance Society to notify all cases is hardly feasible in view of their dependent position. Nor can the obligation on the occupiers lead to the desired result because of their lack of medical knowledge and the fact that by notifying they might be forced to act to their own disadvantage. A successful effort in this direction is recorded in Saxony, where lead poisoning was first made a notifiable disease, and later the general duty of notification of industrial poisoning was prescribed by Order dated March 4, 1901. +-----------------------+-----------------------------------------------+ \| \| Reported Cases.[E] \| \| Disease and Industry. +-------+-------+-------+-------+-------+-------+ \| \| 1912. \| 1911. \| 1910. \| 1909. \| 1908. \| 1907. \| \| (1) \| (2) \| (3) \| (4) \| (5) \| (6) \| (7) \| +-----------------------+-------+-------+-------+-------+-------+-------+ \|Lead Poisoning \|587 (44\|669 (37\|505 (38\|553 (30\|646 (32\|578 (26\| \| 1. Smelting of metals\| 56 (7\| 48 (3\| 34 (5\| 66 (5\| 70 (2\| 28 (2\| \| 2. Brass works \| 5 \| 9 (1\| 7 \| 5 \| 6 \| 9 (1\| \| 3. Sheet lead and \| \| \| \| \| \| \| \| lead piping \| 6 \| 12 \| 4 \| 9 (2\| 14 \| 6 \| \| 4. Plumbing and \| \| \| \| \| \| \| \| soldering \| 35 (5\| 37 (2\| 25 (1\| 28 \| 27 \| 20 (2\| \| 5. Printing \| 37 \| 32 (2\| 33 (4\| 21 (1\| 30 (2\| 26 (3\| \| 6. File cutting \| 13 \| 18 (2\| 9 (1\| 8 \| 9 (2\| 10 \| \| 7. Tinning \| 15 (11\| 13 \| 17 \| 22 \| 10 \| 25 \| \| 8. White lead \| 23 \| 41 (2\| 34 (1\| 32 (2\| 79 (3\| 71 \| \| 9. Red lead \| 3 \| 13 (1\| 10 \| 10 \| 12 \| 7 \| \| 10. China and \| \| \| \| \| \| \| \| earthenware \| 80 (14\| 92 (6\| 77 (11\| 58 (5\|117 (12\|103 (9\| \|10a. Litho-transfers \| 1 (1\| 1 \| 1 \| 1 \| 2 \| 10 \| \| 11. Glass cutting and \| \| \| \| \| \| \| \| polishing \| 1 (1\| 5 \| — \| 4 (2\| 3 (1\| 4 \| \| 12. Vitreous \| \| \| \| \| \| \| \| Enamelling \| 5 \| 19 (1\| 17 \| 7 \| 7 \| 6 \| \| 13. Electric \| \| \| \| \| \| \| \| accumulators \| 38 (1\| 24 (1\| 31 \| 27 (2\| 25 (1\| 21 \| \| 14. Paints and colours\| 19 \| 21 \| 17 (1\| 39 (2\| 25 \| 35 (1\| \| 15. Coach building \| 84 (7\|104 (5\| 70 (6\| 95 (6\| 70 (3\| 70 (3\| \| 16. Ship building \| 34 (2\| 36 (6\| 21 (2\| 27 (1\| 15 \| 22 (1\| \| 17. Paint used in \| \| \| \| \| \| \| \| other industries\| 48 (3\| 56 (1\| 51 (3\| 42 \| 47 (1\| 49 (2\| \| 18. Other industries \| 84 (2\| 88 (4\| 47 (3\| 52 (2\| 78 (5\| 56 (2\| \| \| \| \| \| \| \| \| \|Phosphorus Poisoning \| — \| — \| — \| 3 \| 1 \| 1 (1\| \| \| \| \| \| \| \| \| \|Arsenic Poisoning \| 5 \| 10 (1\| 7 \| 4 \| 23 (1\| 9 (2\| \| \| \| \| \| \| \| \| \|Mercurial Poisoning \| 17 \| 12 \| 10 (1\| 9 \| 10 \| 7 \| \| \| \| \| \| \| \| \| \|Anthrax \| 47 \| 64 (11\| 51 (9\| 56 (12\| 47 (7\| 58 (11\| \| Wool \| 31 (6\| 35 (10\| 28 (3\| 28 (3\| 18 (3\| 23 (3\| \| Horsehair \| 7 \| 8 (1\| 6 (1\| 8 (2\| 10 \| 17 (4\| \| Handling of hides and \| \| \| \| \| \| \| \| skins \| 8 \| 20 \| 14 (3\| 18 (6\| 13 (1\| 12 (2\| \| Other industries \| 1 \| 1 \| 3 (2\| 2 (1\| 6 (3\| 6 (2\| +-----------------------+-------+-------+-------+-------+-------+-------+ +--------------+-------+-------+-------+-------+-------+-------+--------+ \| \| 1906. \| 1905. \| 1904. \| 1903. \| 1902. \| 1901. \| 1900. \| \| \| (8) \| (9) \| (10) \| (11) \| (12) \| (13) \| (14) \| +--------------+-------+-------+-------+-------+-------+-------+--------+ \|Lead \|632 (33\|592 (23\|597 (26\|614 (19\|629 (14\|863 (34\|1058 (38\| \| 1. \| 38 (1\| 24 (1\| 33 (1\| 37 (2\| 28 \| 54 (3\| 34 (1\| \| 2. \| 11 \| 5 (1\| 10 (1\| 15 \| 5 \| 6 (1\| 3 \| \| 3. \| 7 \| 9 \| 7 \| 11 \| 12 \| 17 \| 17 (1\| \| 4. \| 16 (4\| 24 (2\| 21 (3\| 26 \| 23 (1\| 23 \| 9 \| \| 5. \| 16 (2\| 19 (4\| 15 \| 13 (2\| 19 \| 23 (1\| 18 (2\| \| 6. \| 15 \| 12 \| 20 (4\| 24 (2\| 27 (1\| 46 (7\| 40 (3\| \| 7. \| 18 (1\| 14 (1\| 10 \| 14 \| 11 \| 10 \| 5 \| \| 8. \|108 (7\| 90 \|116 (2\|109 (2\|143 (1\|189 (7\| 358 (6\| \| 9. \| 6 \| 10 \| 11 \| 6 \| 13 \| 14 \| 19 \| \| 10. \|107 (4\| 84 (3\|106 (4\| 97 (3\| 87 (4\|106 (5\| 200 (3\| \| 10a. \| 5 \| 5 \| 3 \| 3 \| 2 \| 7 \| 10 \| \| 11. \| 4 (1\| 3 \| — \| 4 \| 8 (2\| 11 (3\| 7 \| \| 12. \| 4 \| 2 \| 3 \| 4 \| 3 (1\| 9 \| 11 \| \| 13. \| 26 \| 27 (1\| 33 \| 28 \| 16 (1\| 49 (1\| 33 \| \| 14. \| 37 \| 57 (1\| 32 (1\| 39 (1\| 46 \| 56 \| 56 (1\| \| 15. \| 85 (7\| 56 (3\| 49 (4\| 74 (5\| 63 (1\| 65 (4\| 70 (5\| \| 16. \| 26 (1\| 32 (2\| 48 \| 24 (1\| 15 (1\| 28 (1\| 32 (2\| \| 17. \| 37 (3\| 49 (2\| 27 (3\| 46 (1\| 44 (1\| 61 \| 50 (5\| \| 18. \| 66 (2\| 70 (1\| 53 (3\| 40 \| 64 \| 89 (1\| 86 (4\| \| \| \| \| \| \| \| \| \| \|Phosphorus \| — \| 3 (1\| 1 (1\| — \| 1 (2\| 4 \| 3 \| \| \| \| \| \| \| \| \| \| \|Arsenic \| 5 \| 1 \| 5 \| 5 \| 5 \| 12 (1\| 22 (3\| \| \| \| \| \| \| \| \| \| \|Mercurial \| 4 \| 8 \| 3 \| 8 \| 8 \| 18 \| 9 \| \| \| \| \| \| \| \| \| \| \|Anthrax \| 67 (22\| 59 (18\| 50 (10\| 47 (12\| 38 (9\| 39 (10\| 37 (7\| \| Wool \| 24 (8\| 34 (12\| 12 (1\| 20 (5\| 12 (2\| 6 (4\| 9 (2\| \| Horsehair \| 10 (4\| 7 (1\| 12 (4\| 7 (1\| 10 (2\| 9 (1\| 12 (3\| \| Hides \| 19 (7\| 17 (4\| 18 (3\| 12 (1\| 11 (5\| 20 (5\| 9 (1\| \| Other \| 14 (3\| 1 (1\| 8 (2\| 8 (5\| 5 \| 4 \| 7 (1\| +--------------+-------+-------+-------+-------+-------+-------+--------+ My own experience does not lead me to expect much in elucidation of industrial diseases from the Sick Insurance Societies. In Austria they make a statistical return as to the causation of illness to the central authorities. I have myself—in my capacity as an official of the State Central Board—examined these in order to try and gain knowledge of the extent of industrial disease in Bohemia. In spite of the returns drawn up by the district surgeon who visits the factories in question, it was impossible for me to obtain a complete picture of the extent of industrial sickness. The reports only give valuable data on which to base action in particular cases, and from this standpoint I do not under-estimate their value. But so far as the expressed wish of the International Association is concerned they appear to fulfil it, inasmuch as for specially dangerous trades special reports are issued, the Austrian law for sick insurance requiring such industries to institute separate sick insurance funds with separate statistics. Hence, under present conditions, I do not see how the duty of notification will be effective. There remains the endeavour to secure insurance and the right to claim compensation for industrial disease in the same way as is provided for accidents. This point was fully discussed at the eighth International Congress for Workmen’s Insurance held in Rome in 1908. There is no valid ground for granting compensation only for _sudden_ disturbance of health arising in the course of employment by accident or acute poisoning, and withholding it in the case of _gradual_ disturbance of health caused equally by the trade, as the effects of such chronic indisposition weigh often no less heavily on the sufferer. Inclusion of industrial disease in the same category as accident insurance, as indeed has been done in France, Switzerland and Great Britain, has, apart from the fact that it is dictated by fairness and humanity, the advantage of removing existing hardship and of solving doubtful cases. Correct statistics, further, would thus be obtainable for the first time, and the employer by insurance would be freed from the legal proceedings now frequently brought against him for injury due to chronic industrial poisoning. And it seems the more right and just course to institute a general scheme of insurance against industrial disease than to have recourse to an Employer’s Liability Act in this or that case, particularly as the question often arises in regard to a disease which develops gradually—In whose employment was the disease contracted? Clearly in such a scheme of insurance against both accident and industrial disease only specific industrial diseases would be included, i.e. diseases in which the connection with the industry can be clearly established as due to causes inherent in the industry, and traceable to definite materials used. Such diseases as tuberculosis and the effects of dust inhalation (bronchitis, &c.), which as industrial diseases occur only too often, cannot be called specific, because they arise outside the industry and make decision impossible as to whether or not in a particular case the disease owed its origin to the occupation. In order to determine what should be regarded as specific industrial poisons it was deemed necessary to draw up a schedule. For one such list Sommerfeld (in collaboration with Oliver and Putzeys) is responsible, Carozzi of Milan for a second, and Fischer[F] for a third, published in 1910. Those by Sommerfeld and Fischer are constructed in similar fashion—enumeration of (1) the poisonous substance, (2) the industries in which it is made or used, (3) the channel of absorption, and (4) the symptoms produced. Sommerfeld enumerates the poisons in alphabetical order, noting against each the requisite preventive measures, while Fischer adopts a chemical classification, confining himself to general introductory remarks as to prevention. Sommerfeld proposes to limit notification to poisoning sharply defined as to the symptoms set up, such as lead, phosphorus, mercury, arsenic, chromium, carbonic oxide, aniline, benzene, nitrobenzene, carbon bisulphide, and nitrous fumes. This simplifies the obligation to notify, but does not dissipate the fears expressed above as to the difficulty, because in the present development of the chemical industries new substances involving new danger to the persons handling them are constantly being discovered, and thus there can be no finality as to which industrial poisonings should entitle to compensation. And if recourse were had from time to time to additions of new substances to the schedule, reliance would have to be placed on experience with regard to each substance added, and thus the actual individual who had suffered would not benefit. Fischer, indeed, acknowledges that any schedule must be incomplete, and emphasises the fact that continual additions would be necessary; otherwise it would be better to refrain altogether from publication of a list. Such lists may be valuable guides, but no sure foundation for insurance legislation. The only possible way to do this is to give as far as possible a correct definition of the industrial diseases entitling to compensation and, in isolated cases, to leave the decision to the expert opinion of competent judges. Extension of workmen’s insurance to cover chronic industrial poisoning is, however, most desirable in the interest of employers and employed, and also of science. The German accident insurance legislation is especially suited to do this, since the trade organisations direct their attention not only to the prevention of accidents but of industrial diseases also. _SPECIAL PREVENTIVE MEASURES FOR WORKERS_ SELECTION, CHOICE OF TRADE, ALTERNATION OF EMPLOYMENT, MEDICAL CONTROL, SAFETY APPLIANCES, INSTRUCTION AND CO-OPERATION OF WORKERS, CLOTHING, ATTENTION TO CLEANLINESS, FOOD, GENERAL WELFARE As a practical measure in protection against trade risk selection of those capable of resisting danger has to be considered. It is obviously desirable to select for employment in a dangerous trade persons possessing powers of resistance, because predisposition and resistance to the action of poisons differ markedly in individuals. To some extent such a selection comes of itself, as those who are very susceptible are obliged by repeated attacks to give up the work. The social and physical misery, undeserved loss of employment, illness, and perhaps early death following on this kind of selection might be checked by timely medical examination so as to weed out the unfit. But medical examination prior to admission into a dangerous trade (actually practised in many industries involving risk of poisoning) inflicts hardship on those seeking employment, and recruits the ranks of the unwillingly unemployed. It would be much better were it possible to meet the need of selection by pertinent direction and guidance in choice of calling. There should be insistence in technical schools especially on the dangers inherent in certain industries, school medical examination as to physical qualifications for certain industries, and careful note made of individual suitability in labour bureaus, apprentice agencies, and the like. Young female workers, naturally less able to resist, should be excluded from work involving risk of poisoning—a principle which has been acted on in the legislation of civilised countries. Further, workers engaged in industries involving risk should not be exposed to the pernicious influence for too long a time. Hence the hours of employment should be shortened in occupations proved to be injurious to health. An important aid in this respect is alternation of employment. Change of occupation is particularly recommended where the nature of the poisoning of which there is risk is cumulative in action, because in the intervals from the work the system will rid itself of the accumulated store. In this way a number of skilled resistant workers, familiar with the risk and knowing how to meet it, will be maintained. Casual labour works in a vicious circle—increase of fresh workers increases the danger and the number of cases of poisoning, and, _vice versa_, these augment again the need of change in the personnel, so that the number of cases of poisoning rises very high. Thus the industry itself may be endangered, since its prosperity depends mainly upon the existence of a skilled staff of workers. In dangerous trades, therefore, Hermann Weber’s words, ‘Change of work instead of change of workers,’ have much force. Periodical medical examination in these industries cannot well be omitted in order to weed out the physically unfit, and to suspend from work those who show early symptoms. Note should be kept of the state of health of the workers, the results of the periodical medical examination, the duration of symptoms, and the treatment of any illness that occurs. Medical supervision presupposes special training and experience in the medical man entrusted with the task. Further, in some industries in which poisonous materials are used, especially such as set up acute sudden poisoning, there should be a trained staff competent to recognise the first symptoms of poisoning and to render first aid, and having at its disposal adequate means of rescue. Apart from the rescue appliances generally needed in dangerous trades, stress must be laid on the value of oxygen apparatus as a means of saving life. In addition to what is needed for the sufferer there must be defensive apparatus at hand for the rescuers (breathing helmets, &c.), to facilitate and make safe their rescue work when in a poisonous atmosphere. Without such defensive equipment rescuers should never venture into gas conduits, or into any place where presumably a poisonous atmosphere is to be met with. It hardly requires to be said that in dangerous industries medical aid should be within easy reach; in large works actual medical attendance may be necessary. In acute as well as in chronic cases of poisoning early medical intervention is advisable. Hence medical aid should be sought on the earliest appearance of symptoms, and the worker, therefore, should know the nature and action of the poison with which he comes into contact. This brings us to the subject of the education of the worker and particularly observance of all those rules and regulations in which his co-operation is necessary. This co-operation of the workers is indispensable; it is the most important condition of effective defence. The best regulations and preventive measures are worthless if the worker does not observe them. He must be taught their aim, the way of using the means of defence; he must be admonished to use them, and, if necessary, compelled to do so. The co-operation of workmen’s organisations in this matter can avail much, since a workman most readily follows the advice of a fellow-worker. Teaching of the kind suggested can be done in different ways. Apart from lectures and practical courses, concise instructions, either in the form of notices or as illustrated placards, should be posted up in the workrooms or handed in the form of leaflets particularly to the newly employed. Distribution of such leaflets might well be placed as a duty on the employer. Of preventive measures applying to the individual those are of prime importance which serve to protect the worker, as far as is practicable, from coming into contact with the poison. Protection of this kind is attained by wearing suitable clothing, use of respirators, and careful cleanliness—especially before partaking of food. It cannot be too strongly urged that these precautions are a very potent defence against the danger of industrial poisoning, especially of the chronic forms, and in teaching workers their importance must be insisted on. It is not sufficient merely to put on overalls over the ordinary clothes. The ordinary clothes must be taken off before the commencement of work, and working suits put on, to be taken off again before the principal midday meal and before leaving work. They should be made of smooth, durable, washable material, and be properly washed and dried not less often than once a week. They must be plainly cut without folds or pockets. Direct handling of the poisonous substances is to be avoided, but where this is necessary impervious gloves may have to be worn, especially in the case of poisons which can be absorbed through, or act injuriously on, the skin. If there is risk of splashing or spilling of poisonous liquids on to the clothes, impermeable or partly impermeable overalls (aprons, &c.) should be worn. The obligation of providing the overalls or working suits falls naturally on the employer in industries where poisonous substances are used, and there is equally obligation on the employee to use the articles provided. Suitable cloakroom accommodation is essential, by which is meant room not only to change clothes with cupboards or hooks on one side for clothing taken off on commencement of work and on the other the working suits, but also ample washing accommodation. These cupboards should be double, that is, be divided by a partition into two parts, one serving for the ordinary and the other for the working clothes. [Illustration: FIG. 35.—Aluminium Respirator] Protection of the respiratory organs can to some extent be obtained by so-called respirators worn over the mouth and nose. Often they consist simply of a moist sponge or folds of cloth, or again may be complicated air-proof affairs enclosing mouth and nose, or the whole face like a mask, or even the head like a helmet; they fit close, and the aperture for respired air is provided with filtering material (cotton wool, &c.) placed between two layers of wire gauze. The outer layer of the gauze moves on a hinge, so that the filtering material can be renewed after each time that it has been used. The construction of respirators is extraordinarily varied. One form is illustrated. They must be light, and in order not to obstruct breathing seriously they are often provided with valves—closing during inspiration and opening during exhalation. Generally the respirators in common use do not quite satisfactorily fulfil the conditions required. After a time the pressure becomes irksome, the face becomes hot, breathing more difficult, and discomfort from wearing them unbearable. Respirators are only to be regarded in the light of secondary aids and for occasional use. During temporary exposure to an atmosphere charged with poisonous dust the wearing of an efficient apparatus—preferably one protecting the head—is very desirable. [Illustration: FIG. 36.—Smoke Helmet, Flexible Tubing, and Foot Bellows (_Siebe, Gorman & Co._)] Respirators afford no protection, or a very imperfect one, against dangerous gases or fumes. If soaked with an absorbing or neutralising fluid they can scarcely be worn for any length of time. In an atmosphere charged with poisonous gas recourse should be had either to a smoke helmet with flexible tubing and bellows or to an oxygen breathing apparatus so constructed that the workman carries the necessary supply of oxygen with him in a knapsack on his back. In the latter case oxygen from a compressed cylinder of the gas is conveyed to the breathing mask, so that respiration is independent of the surrounding atmosphere. [Illustration: FIG. 37.—Diagram of Draeger 1910-11, Pattern H (_R. Jacobson_) P Alkali cartridges; K Cooler; C Aspirating pipe; L₁ Purified air; L₂ Expired air.] The mode of working is represented diagrammatically in figs. 37 and 40. After putting on the helmet, the bag is first filled with fresh air, the air valve is then closed, and the valve of the oxygen cylinder unscrewed so as to permit of the flow of the oxygen which, mixes with the air in the bag, and begins to circulate; the expired air passes through the caustic potash pellets P, which free it of carbonic acid gas, so that, with a fresh supply of oxygen from the cylinder through the pipe C, it is regenerated and made fit for breathing again. The pressure in the cylinder is measured by a manometer, which indicates also when the supply of oxygen gives out. [Illustration: FIG. 38.—Showing the Potash Cartridge No. 2 with Change Mechanism X; No. 2 Oxygen Cylinder with Spanner V; and on the Left a Hexagonal Socket U, for unscrewing the Locking Nuts of Reserve Cylinders (_R. Jacobson_)] [Illustration: FIG. 39.—‘Proto’ patent self-contained breathing apparatus (_Siebe, Gorman & Co._)] Another apparatus—the ‘Proto’ patent self-contained breathing apparatus (Fleuss-Davis patents)—is also illustrated in fig. 39. Illustration 40 gives a diagrammatic view of the principle upon which it is designed. The instructions for using the ‘Proto’ apparatus are as follows: _The oxygen cylinders_ (B, B), having been charged with oxygen through the nipple at (H) to a pressure of 120 atmospheres (about 1800 lbs. per square inch), are to be re-attached to the belt as shown, and the reducing valve, with its tubes, &c., is to be connected to the nipple at (H). This supply is sufficient for fully two hours. _Charging the breathing bag._—Put 4 lbs. of stick caustic _soda_ into the bag (D), i.e. 2 lbs. into each compartment, and immediately fasten the mouth of the bag by means of the clamps and wing nuts (O). If the apparatus is not to be used at once, but is to be hung up for use at some future time, the indiarubber plug which is supplied with the apparatus should be tightly fitted into the mouthpiece in order to prevent access of air to the caustic soda, and to preserve it until required for use. See that the inlet and outlet valves (T and S) and the connection (N) are screwed up tightly. The small relief valve (K) is only to be opened (by pressing it with the finger) when the bag becomes unduly inflated through excess of oxygen. This may occur from time to time, as the reducing valve is set to deliver more than the wearer actually requires. _Equipment._—The whole apparatus is supported upon a broad belt which is strapped round the body. The bag is also hung by a pair of shoulder braces. The wearer having put the equipment over his shoulders, fastens the belt and takes the plug out of the mouthpiece. The moment the mouthpiece is put into the mouth or the mask is adjusted, the main valve (H) is to be opened not more than one turn and the necessary supply of oxygen will then flow into the bag. It is advisable to open the by-pass (I) to inflate partially the breathing bag (D) for a start, but this valve should again be screwed up quite tight and not touched again, except in the case of emergency as previously described should the bag become deflated. Breathing will then go on comfortably. Should the by-pass (I) on the reducing valve (C) get out of order then the wearer should turn on the by-pass (I) from time to time to give himself the necessary quantity of oxygen, but, as stated above, this is only to be done in case of deflation of the bag. The best guide as to the quantity of oxygen to admit _in the above circumstances_ is the degree of inflation of the breathing bag. It will be found to be quite satisfactory if the bag be kept moderately distended. _After using the apparatus._—The caustic soda should _at once_ be thrown away, but if it is neglected and the soda becomes caked, it must be dissolved out with warm water before putting in a fresh supply. Caustic soda will not damage vulcanised indiarubber, but it will damage canvas and leather, and will burn the skin if allowed to remain upon it. If the apparatus is to be used again at once, it can be recharged with caustic soda at once, but if it is only to be charged ready for use at some future time the indiarubber bag should be thoroughly washed out with warm water and dried inside with a cloth or towel. When emptying or recharging the rubber bag with caustic soda, it must always be removed from the canvas bag. After use each day, it is advisable to wash the rubber mouthpiece (or mask, as the case may be) with yellow soap and water. This acts as a preservative to the indiarubber. Every man who is to use the apparatus should have his own mouthpiece and noseclip, or mask, as the case may be, under his own special care, both for sanitary reasons and so that he may shape and adjust the mask to fit himself comfortably and air-tightly, to such an extent that if the outlets are stopped up by the hands while the mask is held in position by its bands no breath can pass in or out. [Illustration: FIG. 40.—‘Proto’ Patent Self-breathing Apparatus (_Siebe, Gorman & Co._)] [Illustration: FIG. 41.—Arrangement of Cloak-room, Washing and Bath Accommodation, and Meal-room in a White Lead Factory] Where poisonous substances giving off dust or fumes are used, regular washing and rinsing the mouth (especially before meals and on leaving) is of great importance. Naturally the washing conveniences (basins, soap, brushes, towels) must be sufficient and suitable, and the workers instructed as to the importance of cleanliness by the foreman. They should be urged to bath in rotation, and time for it should be allowed during working hours. The taking of meals and use of tobacco in the workrooms must be prohibited. Meal rooms should be so arranged as to be contiguous to the cloakroom and washing accommodation, the worker gaining access to the meal room through the cloakroom and bathroom. The arrangement described is illustrated in fig. 41. The meal room serves also the purpose of a sitting-room during intervals of work, and it goes without saying that cloakroom and lavatory accommodation are as necessary in small as in large premises. Simple lavatory basins of smooth impervious surface fitted with a waste pipe and plug, or tipping basins, are recommended in preference to troughs which can be used by several persons at once. Troughs, however, without a plug, and with jets of warm water, are free from objection. The douche bath has many advantages for workmen over the slipper bath. The initial cost is comparatively small, so that it can be placed at the disposal of the workers at very small outlay. Maintenance and cleanliness of douche baths are more easily secured than of other kinds, where changing the water and keeping the bath in good order involve time and expense. A dressing-room should form part of the douche or slipper bath equipment. Walls and floors must be impervious and, preferably, lined with smooth tiles or cement. It is better that the shower bath should be under the control of the worker by a chain rather than be set in motion by means of mechanism when trodden upon. The arrangement of baths is illustrated in fig. 43. In many large works large bath buildings have been erected. Fig. 44 is a plan of the splendid bath arrangements at the colour works of Messrs. Lucius, Meister & Brüning of Höchst a.-M. [Illustration: FIG. 42.—Good Washing and Bath Accommodation in a Lead Smelting Works] [Illustration: FIG. 43.—Washing Trough, Douche Baths, and Clothes Cupboards, Type common on the Continent] [Illustration: FIG. 44A.—Baths in the Höchst Aniline Works (_after Grandhomme_)] [Illustration: FIG. 44B.—Ground Floor] [Illustration: FIG. 44C.—First Floor. _a_, _c_, Baths (slipper and douche) for workmen; _b_, Washing accommodation for workmen; _d_, _e_, Baths for officials; _g_, Attendant’s quarters; _f_, Hot air (Turkish) baths; _i_, Warm water reservoir.] Naturally maintenance of the general health by good nourishing diet is one of the best means of defence against onset of chronic industrial poisoning. Over and over again it has been noticed that ill-fed workers speedily succumb to doses of poison which well-nourished workers can resist. It is not our province here to discuss fully the diet of a working-class population. We merely state that it is a matter of vital importance to those employed in dangerous trades. The question of a suitable drink for workers to take the place of alcohol calls for special attention, as, when complicated with alcoholism, both acute and chronic poisonings entail more serious results than they otherwise would do. Over-indulgence in alcohol, owing to its effect on the kidneys, liver, digestion, nervous system, and power of assimilation generally, requires to be checked in every way possible. Apart from good drinking water, milk, coffee, tea, fruit juices and the like, are excellent. Milk is especially recommended, and should be supplied gratis to workers in dangerous trades, notably where there is risk of lead poisoning. Lastly, other features such as games and exercise in the open air, which help to strengthen bodily health, must not be forgotten. In this connection much good work has already been done by employers’ and workers’ organisations. IV _GENERAL REMARKS ON PREVENTIVE MEASURES_ GENERAL PRINCIPLES, SUBSTITUTES FOR DANGEROUS MATERIALS, CLEANLINESS OF WORKROOMS, CUBIC SPACE, VENTILATION, REMOVAL OF DUST AND FUMES Preventive measures against industrial poisoning aim at an unattainable goal of so arranging industrial processes that employment of poisonous substances would be wholly avoided. Such an ideal must be aimed at wherever practicable. Prohibition of direct handling of poisonous substances is also sometimes demanded, which presupposes (although it is not always the case) that this is unnecessary or can be made unnecessary by suitable mechanical appliances. We have to be contented, therefore, for the most part, with removal of injurious dust and fumes as quickly as possible at the point where they are produced, and regulations for the protection of workers from industrial poisoning deal mainly with the question of the prevention of air contamination and removal of contaminated air. Substitution of non-injurious for injurious processes is only possible in so far as use of the harmless process gives technically as good results as the other. If such a substitute can be found let it be striven for. Mention has already been made of international prohibition of certain substances, and attention has been drawn to economical considerations affecting this point. Prohibition obviously may paralyse branches of industry and hit heavily both employers and employed. The skilled trained workers are just the ones to suffer, since they are no longer in a position to take up another equally remunerative trade. Judgment has to be exercised before enforcing new regulations in order that good and not harm may follow. If a satisfactory substitute be discovered for methods of work injurious to health, then ways and means will be found to make the alteration in the process economically possible. It may, however, demand sacrifice on the part of employers and employed, but the progress is worth the sacrifice. The following are instances of substitution of safe processes for those involving risk: generation of dust can sometimes be avoided by a ‘wet’ method (watering of white lead chambers, grinding pulp lead with oil, damping of smelting mixtures, &c.); the nitrate of silver and ammonia process has replaced the tin and mercury amalgam used in silvering of mirrors; electroplating instead of water gilding (coating objects with mercury amalgam and subsequently volatilising the mercury); enamelling with leadless instead of lead enamels; use of air instead of mercury pumps in producing the vacuum in incandescent electric lamps. Dealing further with the sanitation of the factory and workshop after personal cleanliness, the next most important measure is cleanliness of the workroom and purity of the air. Workrooms should be light and lofty; and have floors constructed of smooth impervious material easily kept clean. The walls should be lime-washed or painted with a white oil paint. Angles and corners which can harbour dirt should be rounded. Cleansing requires to be done as carefully and as often as possible, preferably by washing down or by a vacuum cleaner. Saturation of the floor with dust oil is recommended by some authorities in trades where poisonous dust is developed and is permitted as an alternative to the methods described. I refrain from expressing an opinion on this method of laying dust, since by adoption of the practice insistence on the need for removal of the poisonous material from the workrooms loses its force—a thing, in my opinion, to be deprecated. The necessity of keeping the atmosphere of workrooms pure and fresh makes it essential that there should be sufficient cubic space per person and that proper circulation of the air should be maintained. The minimum amount of cubic space legally fixed in many countries—10-15 cubic metres—is a minimum and should be greatly exceeded where possible. Natural ventilation which is dependent upon windows, porosity of building materials, cracks in the floors, &c., fails when, as is desirable for purposes of cleanliness, walls and floors are made of smooth impermeable material, and natural ventilation will rarely supply the requisite cubic feet of fresh air quickly enough. Ordinarily, under conditions of natural ventilation, the air in a workroom is renewed in from one to two hours. Artificial ventilation therefore becomes imperative. Natural ventilation by opening windows and doors can only be practised in intervals of work and as a rule only in small workrooms. During work time the draught and reduction of temperature so caused produce discomfort. _Artificial ventilation_ is effected by special openings and ducts placed at some suitable spot in the room to be ventilated and arranged so that either fresh air is introduced or air extracted from the room. The first method is called propulsion, the latter exhaust ventilation. Various agencies will produce a draught in the ventilating ducts, namely, difference of temperature between the outside and inside air, which can be artificially strengthened (_a_) by utilising the action of the wind, (_b_) by heating the air in the exhaust duct, (_c_) by heating apparatus, and (_d_) by mechanical power (use of fans). Where advantage is taken of the action of the wind the exit to the ventilating duct must be fitted with a cowl. The draught in pipes is materially increased if they are led into furnace flues or chimneys; in certain cases there is advantage in constructing perpendicular ventilating shafts in the building extending above the roof and fitted with cowls. Combination of heating and ventilation is very effective. [Illustration: FIG. 45.—Steam Injector (_after Körting_), showing steam injector and air entry] In workrooms, however, where there is danger of poisoning by far the most effective method of ventilation is by means of fans driven by mechanical power. All the means for securing artificial ventilation hitherto mentioned depend on a number of factors (wind, difference of temperature, &c.), the influence of which is not always in the direction desired. Exact regulation, however, is possible by fans, and the quantity of air introduced or extracted can be accurately calculated beforehand in planning the ventilation. In drawing up such a plan, detailing the arrangement, proportions of the main and branch ducts, expenditure of power, &c., a ventilating engineer should be consulted, as it is his business to deal with complicated problems of ventilation depending entirely for success on the design of the ventilation. Injectors are usually only employed for special technical or economical reasons. A jet of steam or compressed air which acts on the injector creates a partial vacuum and so produces a powerful exhaust behind. Fig. 45 shows the mechanism of an injector. They are used for exhausting acid fumes which would corrode metal fans and pipes, and for explosive dust mixtures where fans are inadmissible. [Illustration: FIG. 46.—Propeller Fan coupled to Electromotor (_Davidson & Co., Ltd._)] In the industries described in this book fans are most commonly used. These are, in the main, wheels with two or more wing-shaped flattened blades. Some are encased, others are open and fitted by means of annular frames in the ducts according to the intended effect and kind of fan. Fans are of two kinds, propeller and centrifugal, and, according to the pressure they exert, of low, medium, or high pressure. They are now often driven electrically, in which case there is advantage in coupling them directly with the motor. _Propeller fans_ have curved screw-shaped blades and are set at right angles in the duct upon the column of air in which they act by suction. The air is moved in the direction of the axis of the fan, and generally it is possible, by reversing the action, to force air in instead of extracting it. The draught produced is a low-pressure one (generally less than 15 mm. of water). The current of air set in motion travels at a relatively slow speed, yet such fans are capable, when suitably proportioned, of moving large volumes of air. Propeller fans are specially suitable for the general ventilation of rooms when the necessary change of air is not being effected by natural means. [Illustration: FIG. 47.—The Blackman (Belt-driven) Fan.] _Centrifugal_ or _high-pressure fans_ (see figs. 48A and 48B) are always encased in such a way that the exhaust ducts enter on one or both sides of the axis. The air thus drawn in is thrown by the quickly rotating numerous straight blades to the periphery and escapes at the outlet. The centrifugal fan travels at a great speed, and the air current has therefore great velocity and high pressure. When the pressure is less than 120 mm. it is described as a medium, and when greater, a high-pressure fan. For the former a galvanised iron casing suffices; for the latter the casing requires to be of cast iron. Medium pressure centrifugal fans are used to exhaust dust or fumes locally from the point at which they are produced. They play a great part in industrial hygiene. [Illustration: FIG. 48A.—‘Sirocco’ Centrifugal Fan] [Illustration: FIG. 48B.—Showing exhaust aperture and fan blades] High-pressure fans are used mainly for technical purposes, as, for example, the driving of air or gas at high pressure. Localised ventilation is needed to limit diffusion of dust and fumes, which is attained in a measure also by separation of those workrooms in which persons come into contact with poisonous materials from others. Separation of workrooms, however, is not enough, as it is the individual who manipulates the poison for whom protection is desired. To enclose or hood over a dusty machine or fume-producing apparatus completely, or to close hermetically a whole series of operations by complicated technical arrangements, is only possible when no opening or hand feeding is required. Dangerous substances can only be wholly shut in by substitution of machinery for handwork. [Illustration: FIG. 49.—Localised Exhaust Ventilation in a Colour Factory (_Sturtevant Engineering Co., Ltd._)] [Illustration: FIG. 50A. FIG. 50B. Ball Mills] Where, however, absolute contact is unavoidable the dust or fume must be carried away at its source. This is done by exhaust ventilation, locally applied, in the following manner: A suitable hood or air guide of metal or wood is arranged over the point where the dust is produced, leaving as small an opening as possible for necessary manipulations. The hood is connected with a duct through which the current of air travels. An exhaust current dependent upon heat will only suffice in the case of slight development of dust or fumes. As a rule exhaust by a fan is necessary. Where exhaust ventilation has to be arranged at several points all these are connected up by branch ducts with the main duct and centrifugal fan. Where the ducts lie near the floor it is advisable to fix adjustable openings in them close to the floor to remove the sweepings. [Illustration: FIG. 51.—Ventilated Packing Machine (_after Albrecht_) _A_ Worm; _B_ Collector; _D_ Fan; _E_ Filter bag; _J_, _F_ Movable shutters; _H_ Jolting arrangement] It is important for the exhaust system of ventilation to be designed in general so that the dust is drawn away from the face of the worker downwards and backwards. Many horrible arrangements are found in which the dust is first aspirated past the mouth and nose before it is drawn into a hood overhead. The proportions of the branch pipes to the main duct require to be thought out, and friction and resistance to the flow must be reduced as far as possible by avoidance of sharp bends. Branch pipes should enter the main duct at an angle of thirty degrees. A completely satisfactory system requires very special knowledge and often much ingenuity when the apparatus is complicated. Disintegrators and edge runners can generally be covered in and the cover connected with an exhaust. Ball mills, when possible, are best as the rotating iron cylinder containing the steel balls and the material to be pulverised is hermetically closed. Powdered material can be carried mechanically from one place to another by worms, screws, endless bands, or be driven in closed pipes by means of compressed air. The inevitable production of dust in packing can be avoided by the use of ventilated packing machines, which are especially necessary in the case of white lead, bichromates, basic slag, &c. [Illustration: FIG. 52.] The difficulty is great in preventing dust in sieving and mixing, since this is mainly done by hand. Still here, for example, by use of cases with arm-holes and upper glass cover, injury to health can be minimised. Benches with a wire screen and duct through which a downward exhaust passes are useful in sorting operations (fig. 52). Fig. 53 illustrates a grinding or polishing wheel fitted with localised exhaust. [Illustration: FIG. 53.—Removing Dust from Bobs and Mops (_James Keith & Blackman Co., Ltd. By permission of the Controller of H.M. Stationery Office_)] To prevent escape of injurious gases all stills and furnaces must be kept as airtight as possible and preferably under a slight negative pressure. Agitators must be enclosed and should be fitted with arrangements for carrying on the work mechanically or by means of compressed air and, if necessary, exhaust ventilation applied to them. The aim should be to enclose entirely drying and extracting apparatus. [Illustration: FIG. 54.—‘Cyclone’ Separator (_Matthews & Yates, Ltd._)] An important question remains as to what shall be done with the dust and fumes extracted. In many cases they cannot be allowed to escape into the atmosphere outside, and in the interests of economy recovery and utilisation of the waste is the thing to aim at. This vital subject can only receive barest mention here. The dust or fumes extracted require to be subjected to processes of purification with a view to recovery of the often valuable solid or gaseous constituents and destruction of those without value. [Illustration: FIG. 55A. FIG. 55B. Dust-filter of Beth-Lübeck (_after Albrecht_)] [Illustration: FIG. 56.—Dust-filter of Beth-Lübeck—Detail] Collection of dust may take place in settling chambers as in a cyclone separator in which the air to be purified is made to travel round the interior of a cone-shaped metal receptacle, depositing the dust in its passage (see fig. 54). [Illustration: FIG. 57.—Arrangement for Precipitating Dust (_after Leymann_) _A_ Entry of dust laden air; _B_ Fan; _C_ Purified air; _D_ Pipe carrying away water and last traces of dust; _E_ Worm carrying away collection of dust.] The most effective method, however, is filtration of the air through bags of canvas or other suitable fabric as in the ‘Beth’ filter (see figs. 55 and 56). In the ‘Beth’ filter a mechanical knocking apparatus shakes the dust from the bag to the bottom of the casing, where a worm automatically carries it to the collecting receptacle. In the absence of mechanical knocking the filtering material becomes clogged and increases the resistance in the system. Contrivances of the kind unintelligently constructed become a source of danger to the workers. Dust of no value is usually precipitated by being made to pass through a tower down which a fine spray of water falls. If the gases and fumes can be utilised they are either absorbed or condensed—a procedure of the utmost importance for the protection of the workers. Condensation of the gases into a liquid is effected by cooling and is an essential part of all processes associated with distillation. The necessary cooling is effected either by causing the vapours to circulate through coils of pipes surrounded by cold water or by an increase in the condensing surface (extension of walls, &c.), and artificial cooling of the walls by running water. Absorption of gases and fumes by fluids (less often by solid substances) is effected by bubbling the gas through vessels filled with the absorbing liquid or conducting it through towers (packed with coke, flints, &c.), or chambers down or through which the absorbent flows. Such absorption towers and chambers are frequently placed in series. The material thus recovered by condensation and absorption may prove to be a valuable bye-product. Frequently the gases (as in blast furnace gas, coke ovens, &c.) are led away directly for heating boilers, or, as in the spelter manufacture, to make sulphuric acid. V _PREVENTIVE REGULATIONS FOR CHEMICAL INDUSTRIES_ Sulphuric Acid Industry (See also pp. 4-14 and 171) Danger arises from escape of acid gases or in entering chambers, towers, containers, &c., for cleaning purposes. The whole chamber system, therefore, requires to be impervious and the sulphur dioxide and nitrous gases utilised to their fullest extent—a procedure that is in harmony with economy in production. The pyrites furnace must be so fired as to prevent escape of fumes, which is best attained by maintenance of a slight negative pressure by means of fans. The cinders raked out of the furnace because of the considerable amount of sulphur dioxide given off from them should be kept in a covered-in place until they have cooled. Any work on the towers and lead chambers, especially cleaning operations, should be carried out under strict regulations. Such special measures for the emptying of Gay-Lussac towers have been drawn up by the Union of Chemical Industry. Before removal of the sediment on the floor they require a thorough drenching with water, to be repeated if gases are present. Perfect working of the Gay-Lussac tower at the end of the series of chambers is essential to prevent escape of acid gases. In a well-regulated sulphuric acid factory the average total acid content of the final gases can be reduced to 0·1 vol. per cent. Under the Alkali Works Regulation Act of 1881 the quantity was limited to 0·26 per cent. of sulphur dioxide—and this should be a maximum limit. _Entering and cleaning out chambers and towers_ should only be done, if practicable, by workmen equipped with breathing apparatus, and never without special precautionary measures, as several fatalities have occurred at the work. Towers, therefore, are best arranged so as to allow of cleaning from the outside; if gases are noticed smoke helmets should be donned. The same holds good for entering tanks or tank waggons. After several cases of poisoning from this source had occurred in a factory the following official regulations were issued: The deposit on the floor of waggons or tanks shall be removed either by flushing with water without entering the tank itself, or if the tank be entered the deposit is to be scooped out without addition of water or dilute soda solution. Flushing out shall only be done after the workmen have got out. Workmen are to be warned every time cleaning is undertaken that poisonous gases are developed when the deposit on the floor is diluted. Acid eggs, further, are to be provided with a waste pipe and manhole to enable cleaning to be done from outside. The poisoning likely to arise is partly due to arsenic impurity (development of arseniuretted hydrogen gas) in the sulphuric acid used. Unfortunately arsenic free acid is very difficult to obtain. Hydrochloric Acid—Saltcake and Soda Industries (See also pp. 15-23 and 170) Preventive measures here depend upon observance of the general principles already discussed. The _saltcake pan_ and reverberatory furnace require to be accurately and solidly constructed and the process carefully regulated. Regulations indeed were drawn up at an early date in England as to their working to prevent escape of gases when adding the acid, raking over in the reverberatory furnace, and withdrawal of the still fuming saltcake. The following are the most important of these recommendations: The saltcake pan must not be charged when overheated. Sulphuric acid shall be added only after all the salt has been charged and the door shut. If hydrochloric acid fumes escape at the door when the Glover acid flows in the flow must be interrupted. All doors must be closed while work is in progress. Definite times shall be fixed for withdrawal of the saltcake in order to try and ensure that it be not still fuming, but should this be the case cold sulphate of soda shall be sprinkled over it. The general principle should be observed of maintaining a slight negative pressure in the furnace by insertion of a fan in the gas conduit so as to avoid possible escape of gas. The fuming saltcake is best dealt with by depositing it at once to cool in ventilated receptacles or chambers. On grounds of economy and hygiene as complete an absorption as possible of the hydrochloric acid gas developed in the saltcake and soda ash process is to be aimed at, by conveying it through impervious conduits to the bombonnes and lofty absorption tower filled with coke or flints down which water trickles. The entire loss of hydrochloric acid should not amount to more than 1·5 per cent. of the whole. Under the Alkali Act at first 5 per cent. was allowed, but this is excessive now in view of improved methods of condensation. In the _Leblanc_ process the revolving furnace is on health grounds to be preferred to the hand furnace. Such a furnace occupies the space of but three hand furnaces and can replace eighteen of them. The vast accumulation of waste, consisting mainly of calcium sulphide, and generating sulphuretted hydrogen gas in such amount as to constitute a nuisance, is only partially prevented by the Chance-Claus and other methods of recovery, and makes it most desirable to adopt the Solvay ammonia process. _Note._—_Sulphonal, Oxalic acid, Ultramarine, Alum._—The production of _sulphonal_ is intensely unpleasant owing to the disagreeable smell (like cats’ excrement) of the mercaptan developed. All work therefore must be carried on in air-tight apparatus under negative pressure and careful cooling. Any escaping fumes must be absorbed in solution of acetone and fine water spray. Preparation of _oxalic acid_ unless carried on in closed-in vessels gives rise to injurious and troublesome fumes. If open pans are used, hoods and ducts in connection with a fan should be placed over them. Grinding of _ultramarine_ and _alum_ requires to be done in closed-in mills, and any dust drawn away by locally applied ventilation and filtered. The gases given off in the burning process contain 3 per cent. of sulphur dioxide, which requires to be absorbed—a procedure most easily effected in towers where the upstreaming gas comes into contact with a dilute solution of lime or soda. Chlorine, Bleaching Powder, Chlorine Compounds (See also pp. 23-9 and 173) What has been said as to imperviousness of apparatus, negative pressure maintained by the tall chimney stack or earthenware or fireclay fan, &c., applies equally here. The exhaust ventilation is also required to aspirate the gas into the bleaching chambers. At the end of the system there must be either a tower packed with quicklime to absorb the last traces of chlorine or such a number of bleach chambers into which the gas can be led that no chlorine escapes. Production of chlorine gas electrolytically is to be preferred to other processes on hygienic grounds. Careful cleanliness is the best prophylactic against occurrence of _chlorine rash_ among persons employed in the electrolytic production of chlorine. In some factories attempt has been made to use other substances (magnetite) instead of carbon for the anode, and the success attending their adoption is further proof that the tar cement at the anode helped to cause the acne. In the _Weldon_ process care must be taken that the water lutes are intact, and the stills must not be opened before the chlorine has been drawn off. All processes in which manganese dust can arise (grinding of manganese dioxide and drying of Weldon deposit) should be done under locally applied exhaust. The _bleaching powder_ chambers must be impervious and care taken that they are not entered before the chlorine has been absorbed. Usually the number of lime chambers connected up with each other is such that no chlorine escapes free into the air. Emptying of the finished product should not be done by hand, as considerable quantities of chlorine escape and make the work extremely irksome. Mechanical methods of emptying should be adopted in substitution for hand labour, and of these the Hasenclever closed-in apparatus is the best. Nitric Acid and Explosives (See also pp. 39-49 and 172) In the production of _nitric acid_ complete imperviousness of the system and as complete condensation of the gases as possible by means of tourilles, cooling condensers, and the requisite number of towers are necessary. The method suggested by Valentine of manufacture of nitric acid in apparatus under a partial vacuum has advantages from a hygienic standpoint. Earthenware fans are used to force the nitric acid gases onwards and have the advantage of creating a negative pressure. Great care is needed in handling, emptying, packing, conveying, and storing the acid in consequence of the danger from breaking or spilling. The bottles used must be in perfect condition and must be well packed. No greater stock of nitric acid should be allowed in a room than is absolutely necessary, and care must be exercised in the event of a carboy breaking that the spilt acid does not come into contact with organic substances, as that would increase development of nitrous fumes. Workers must be warned not to remain in rooms in which acid has been spilt. They are only to be entered by workers equipped with breathing apparatus (smoke helmets). Among the special regulations on the subject may be mentioned those of the Prussian Ministerial Decree, dated January 8, 1900, concerning nitrous fumes and means of protection for workers employed with the acid. What has been said on p. 257 in regard to the transport of sulphuric acid applies equally to nitric acid. In the _nitrating_ process in the manufacture of explosives (see p. 47) it is essential that the apparatus is hermetically closed, that agitation is done mechanically, or better still by means of compressed air, and that any fumes developed are exhausted and condensed. In the preparation of _nitro-glycerin_ (see p. 46) the gases developed in the nitration of the waste acid require to be carefully condensed. Contact of nitro-glycerin with the skin has to be avoided and the attention of the workers drawn to the danger. Preparation of _gun cotton_ (see p. 48) takes place in machines which are at the same time nitrating and centrifugalising machines. The apparatus is first filled with the nitrating acid and the cotton added; the fumes are drawn off by earthenware ducts and fans, and lastly the bulk of the acid is removed by centrifugal action. Such machines carry out effectually the principles of industrial hygiene. In the preparation of _fulminate of mercury_ nitrous fumes, cyanogen compounds, and acetic acid compounds are developed by the action of the nitric acid on mercury, and require to be dealt with by exhaust ventilation.[G] Artificial Manures, Fertilizers (See also pp. 53 and 54) In grinding phosphorite and superphosphates, corrosive dust is produced. All grinding operations must, therefore, be carried out automatically in closed apparatus (ball mills, disintegrators, &c.). In making the phosphorite soluble by treatment with sulphuric acid, and subsequent drying of the product, corrosive hydrofluoric acid gas is developed, which requires to be carried away by an acid proof exhaust fan, and condensed in a tower by water (see fig. 58). The modern revolving drying machines are especially serviceable. [Illustration: FIG. 58.—Washing tower for hydrofluoric acid (_after Leymann_.)] In the production of _basic slag_ corrosive dust is given off, causing ulceration of the mucous membrane. Grinding and other manipulations creating dust must be carried on in apparatus under local exhaust ventilation. The following—somewhat shortened—are the German Imperial Regulations, dated July 3, 1909, for basic slag factories. BASIC SLAG REGULATIONS 1. Workrooms in which basic slag is crushed, ground, or stored (if not in closed sacks) shall be roomy and so arranged as to ensure adequate change of air. Floors shall be of impervious material allowing of easy removal of dust. 2. Preliminary breaking of the slag by hand shall not be done in the grinding rooms, but either in the open air or in open sheds. 3. Slag crushers, grinding mills, and other apparatus shall be so arranged as to prevent escape of dust as far as possible into the workrooms. They shall be provided with exhaust ventilation and means for collecting the dust if this cannot be done in the absence of dust. 4. Arrangements shall be made whereby barrows conveying material to the grinding mills shall be emptied directly into partially hooded hoppers provided with exhaust ventilation so as to prevent escape of dust into the workrooms. 5. The casing and joints of the grinding mills, ducts, dust collectors and sieves shall be airtight; if leaks are noticed they must be repaired forthwith. 6. Ducts, dust collectors and sieves shall be so arranged as to enable periodical cleansing to be undertaken from the outside. 7. Repairs of the plant mentioned in Para. 5 in which workers are exposed to inhalation of slag dust shall be entrusted by the occupier only to such workers as wear respirators supplied for the purpose or other means of protecting mouth and nostrils such as wet sponges, handkerchiefs, &c. 8. Emptying of slag powder from the grinding mills and dust collectors and transference to the store rooms shall only be done in accordance with special regulations designed to minimise dust. 9. Filling slag powder into sacks from the outlets of the mills, elevating and discharging it into receptacles shall only be done under efficient exhaust ventilation. 10. Sacks in which the powder is transported and piled in heaps shall be of a certain defined strength to be increased in the case of sacks to be piled in heaps more than 3½ metres in height. Special rooms separated from other workrooms shall be provided for storage of slag powder in sacks. Only the sacks representing the previous day’s production may be stored in the grinding rooms. Basic slag in powder and not in sacks shall be kept in special storage rooms shut off entirely from other workrooms. No person shall enter such storage rooms when they are being filled or emptied. Discharging the contents of the sacks into them shall be done under exhaust ventilation. 11. The floors of the workrooms described in Para. 1 shall be cleaned before the commencement of each shift or in an interval during each shift. No person except those engaged in cleaning shall be present during the operation. If cleaning is effected by sweeping, the occupier shall require the persons doing it to wear the respirators provided or other protection for the mouth and nose. 12. The occupier shall not permit the workers to bring spirits into the factory. 13. A lavatory and cloakroom and, separated from them and in a part of the building free from dust, a meal room shall be provided. These rooms shall be kept clean, free from dust, and be heated during the winter. In the lavatory and cloakroom water, soap, and towels shall be provided and adequate arrangements shall be made for keeping the clothing taken off before commencing work. The occupier shall give the persons employed opportunity to take a warm bath daily before leaving work in a bathroom erected inside the factory and heated during the winter. 14. No woman or male young person under eighteen years of age shall work or remain in a room into which basic slag is brought. Persons under eighteen years of age shall not be employed in beating sacks which have contained basic slag. 15. No person employed in breaking or grinding, emptying, packing, or storing basic slag, shall work more than ten hours daily. There shall be intervals during working hours amounting in the aggregate to two hours, one of them lasting at least an hour. If duration of employment daily is limited to seven hours with never longer than four hours’ work without an interval, only one interval of at least one hour is required. 16. For work mentioned in Para. 15 no person shall be employed without a certificate from an approved surgeon stating that he is free of disease of the lungs and not alcoholic. The occupier shall place the supervision of the health of the workers under a surgeon who shall examine them at least once a month for signs of disease of the respiratory organs and alcoholism. Workers engaged in the operations mentioned in Para. 15 shall be suspended from employment when the surgeon suspects such illness or alcoholism. Those showing marked susceptibility to the effect of basic slag dust shall be permanently suspended. 17. A health Register shall be kept in which shall be entered the precise employment, duration of work, and state of health of the persons employed. 18. The occupier shall obtain a guarantee from the workers that no alcohol or food shall be taken into the workrooms. Preparation of Hydrofluoric Acid (See also pp. 37 and 171) The fumes given off in the preparation of hydrofluoric acid require to be collected in leaden coolers and vessels; that which escapes requires to be absorbed by a water spray in towers. The apparatus must be impervious and kept under a slight negative pressure. Chromium Compounds (See also pp. 55-8 and 185) The German Imperial Decree, dated May 16, 1907, contains the preventive measures necessary in bichromate factories. According to this, workers suffering from ulceration of the skin (chrome holes, eczema) are not to be employed except on a medical certificate that they are free from such affections, and daily examination for signs of ulceration is enjoined, so that those affected may receive prompt treatment. Further, periodical medical examination of the workers is required at monthly intervals. Respirators (for work in which dust cannot be avoided), with lavatory, cloakroom, and meal room accommodation, are to be provided, and also baths. In handling bichromates wearing of impervious gloves may be necessary, and smearing the hands and face with vaseline is recommended. In addition diffusion of dust and fumes must be minimised; machines in which mixing, crushing, and grinding are done must be impervious, and provided with exhaust ventilation. Charging of the furnaces, where possible, should be effected mechanically and the fumes developed both in manipulation of the furnaces and from hot bichromate liquor removed by an exhaust. A leaflet containing directions for workers coming into contact with chromium compounds in chemical factories, dyeing, tanning, wood staining, calico printing, wall paper printing, painting, &c., has been drawn up by Lewin. It contains a list of the poisonous chrome compounds and of the industries in which chrome poisoning occurs, information as to the action of chrome upon the skin and mucous membrane, and the preventive measures necessary. Among the last named are: smearing the skin with oil, use of impervious gloves, respirators in work where dust arises, necessity of cleanliness, and periodical medical examination. For the _chrome tanning industry_ the following leaflet was drawn up by the Imperial Health Office in Berlin, which succinctly states the measures against chrome poisoning in these industries and contains much practical information for the workers: In chrome tanning by the two bath process, the first bath containing potassium bichromate and hydrochloric acid has a corroding effect upon broken surfaces of the skin (scratches, chapped hands, eruptions, &c.). In consequence, they develop into round ulcers (chrome holes) with hard raised edges which are difficult to heal and go on increasing in size unless work at the process is temporarily given up. In persons with very sensitive skin, even though the surface may be intact, handling the liquor brings on sometimes an obstinate rash (eczema) on the hands and forearms. The solution used in the one bath process has no corrosive action, but it is a strong poison, just as is the solution of potassium bichromate of the two bath process. If swallowed, the solutions cause vomiting, diarrhœa, kidney trouble, and even death. Chromium compounds can also enter the body through skin wounds and cause illness. _Prevention._—In order to prevent the occurrence of chrome ulceration, workers employed with chrome or chrome solutions must be especially careful in avoiding injury to the skin of the hands or forearms. This applies especially to workers who carry the vessels containing bichromate, who weigh and dissolve the potassium bichromate, or who come into contact with the tanning liquor or with undressed skins and hides which have lain in the liquor. If, in spite of precautions, eruptions, rashes, or ulceration occur, all work necessitating contact with corrosive tanning liquors should be suspended until they are healed. In order to reduce risk of action of the liquor on the skin, workers employed in the process described would do well if, before commencing work, they carefully smeared hands and forearms with unsalted lard, vaseline, or the like, and during work avoided, as much as possible, soiling the bare hands and arms with the liquor. If, nevertheless, a worker has contracted a chrome hole, or eruption, he should consult a medical man, informing him at the same time of the nature of his work. To avoid internal absorption of chrome, workers preparing the baths must carefully avoid inhaling the dust of chromium salts. These and all other workers engaged with the liquors containing chromium must not take food and drink while at work. Working suits should be taken off and face and hands washed with soap before eating or drinking, and before leaving the factory. Petroleum, Benzine (See also pp. 59-64 and 222-4) As crude petroleum and the higher fractions first distilled from it affect the skin injuriously, wetting the skin should be avoided, and careful cleanliness on the part of the workers enjoined. Workers exposed to the influence of gases escaping from naphtha springs and wells should be equipped with breathing apparatus (smoke helmets); this applies to those who have to enter stills and other apparatus connected with the distillation of petroleum. In the preparation of petroleum by sulphuric acid sulphur dioxide in great quantity is developed, constituting a distinct danger to the workers. This process, therefore, should be carried on in closed vessels furnished with mechanical stirrers or compressed air agitators. The most suitable apparatus is that illustrated in fig. 13. Petroleum tanks must be thoroughly aired before they are cleaned and should be entered only by workers equipped with breathing apparatus. Apparatus containing petroleum and benzine requires, as far as possible, to be closed in and air tight (as, for example, in the extraction of fat from bones and oil seed, in the rubber industry, and in chemical cleaning establishments); where benzine fumes develop they should be immediately drawn away by suitably applied exhaust ventilation. This is necessary, on account of the danger of fire, in chemical cleaning establishments where purification is effected by means of benzine in closed drums. Regulations for benzine extraction plants are contained in the Prussian Ministerial Decree, dated January 5, 1909, for benzine extraction works, and also in that of August 3, 1903, for dry-cleaning premises, to which last were added ‘Directions for safety,’ containing important regulations as to risk from fire. From our standpoint the following points are of interest: care is to be taken to provide and maintain exhaust ventilation directly across the floor. The air, however, must not be allowed to pass near any fire. Drying rooms especially are to be lofty and airy, and separated from other workrooms. In factories with mechanical power the authorities may require provision of artificial ventilation for the drying rooms. Washing machines, centrifugalising machines, and benzine rinsing vessels should be furnished with well-fitting covers to be removed only for such time as is absolutely necessary for putting in and taking out the articles to be cleaned, shaken, or rinsed. The vessels named are to be examined as to their imperviousness at least once every quarter by a properly qualified person. The condition in which they are found is to be noted in a book to be shown to the Factory Inspector and police authorities on demand. Lastly, substitution for benzine of other less poisonous substances such as carbon tetrachloride has been urged. Phosphorus, Lucifer Matches (See also pp. 49-53 and 190) In view of the danger of the lucifer match industry, measures were taken at an early date in almost all civilised states to guard against phosphorus poisoning, and in many countries have led to the prohibition of the use of white phosphorus. Complete prohibition of its manufacture and use was first enacted in Finland (1872) and in Denmark (1874). Prohibition was decreed in Switzerland in 1879 (in January 1882 this was revoked, but again enacted in 1893), and in the Netherlands in 1901. In Germany the law prohibiting the use of white phosphorus came into force in January 1908, and runs as follows: 1. White or yellow phosphorus shall not be employed in the production of matches and other lighting substances. Lighting substances made with white phosphorus shall not be kept for sale, or sold, or otherwise brought on the market. Provided that this shall not apply to ignition strips which serve for the lighting of safety lamps. 2. Persons wilfully infringing this law shall be punished by a fine of 2000 marks. If the infringement occurs through ignorance the fine shall consist of 150 marks. In addition to the fine, all prohibited articles produced, imported, or brought into the trade shall be confiscated, as well as the implements used in their production, without reference to whether they belong to the person convicted or not. If prosecution or conviction of the guilty party cannot be brought home, confiscation nevertheless is to be carried out independently. Roumania and France have a state monopoly of matches; in these states no white phosphorus matches have been produced since 1900 and 1898 respectively. France, by the Law of December 17, 1908, signified concurrence with the International Convention in regard to the prohibition of the use of white phosphorus. In Sweden and Norway the prohibition of white phosphorus is in force only for the home trade. A Swedish Decree, dated December 9, 1896, permitted factories carrying on the manufacture for export to use white phosphorus, and almost precisely similar provisions are contained in the Norwegian Decree. The Swedish Decree, dated March 30, 1900, permits white phosphorus matches to be exported, but not to be sold in the country. In Austria difficulties in regard to prohibition of white phosphorus arose owing to trade conditions (especially in the East), and the attitude of the states competing in the lucifer match trade, particularly Italy and Japan. Austria, therefore, made agreement with international prohibition of white phosphorus, dependent on the attitude of Japan; since Japan did not concur, the decision of Austria fell through. When, however, Italy in the year 1906 joined the Convention, the difficulties were also overcome in Austria, and by a law similar to that of Germany, dated July 13, 1909, prohibition of the manufacture and sale of white phosphorus matches dates from the year 1912.[H] Belgium has refrained from prohibition of white phosphorus, but on the other hand has passed a series of enactments relating to the match manufacture, of which the most essential are here cited, since they characterise the measures which come into consideration for factories in which white phosphorus is still employed. _Royal Decree, dated March 25, 1890, modified by the Royal Decree, dated February 12, 1895, and November 17, 1902, concerning employment in lucifer match factories._ 1. In match factories where white phosphorus is used, mixing the paste and drying the dipped matches shall be carried on in a place specially set apart for the purpose. 2. Mixing the paste shall be carried on in an entirely closed vessel or in one connected with an efficient exhaust draught locally applied. The proportion of white phosphorus in the paste shall not exceed in weight 8 per cent. of the total material, not including water. 3. Hoods and ducts communicating with an exhaust draught shall be installed at the level of the plates for dipping white phosphorus matches, and over the vessels containing the paste. 4. Drying rooms for white phosphorus matches, if entered by the workers, shall be mechanically ventilated. 5. Rooms in which phosphorus fumes can arise shall be lofty and well ventilated, preferably by an exhaust at the level of the work benches, communicating with the main chimney stack. The workrooms shall be kept clean. No food or drink shall be taken in them. 6. In every match factory the workers shall have at their disposal a special cloak room and suitable and sufficient washing accommodation, so as to be able to change clothes before commencing, and at the end of, work, and to wash the hands and face on leaving. Cleanliness will be obligatory upon the workers manipulating phosphorus paste or matches. 7. Workers coming into contact with phosphorus paste or matches shall be examined monthly by a surgeon appointed by the Minister of Industry, who shall be paid by the occupier. Workers having decayed, unstopped teeth, or exhibiting symptoms of gingivitis or stomatitis, or in poor health at the time of examination, shall be temporarily suspended from work. The surgeon shall enter the results of his monthly examinations in a prescribed register. This register shall be shown to the Factory Inspector on demand. These decrees are supplemented by further orders regarding the taking of samples of paste in match factories and store houses (Royal Orders of March 25, 1890; February 12, 1895; April 18, 1898; November 17, 1902). As is evident from the Belgian enactment, in states where prohibition of white phosphorus is not in force, palliative measures only are possible and even then they can only be enforced in large factories when automatic machinery is used to eliminate hand labour in dangerous operations. In this respect the introduction of closed, ventilated, mechanical mixing apparatus provided with mechanical stirrers, closed and ventilated mechanical dipping and drying apparatus, are especially important. Certain modern American machines carry through the whole complicated process of the phosphorous match industry automatically. Seeing that prohibition of white phosphorus is an accomplished fact and that matches free from risk in their manufacture answer every purpose, the universal enforcement of the prohibition of white phosphorus should be striven for in civilised states. Carbon bisulphide (See also pp. 68-71 and 193-5) Use of carbon bisulphide in the vulcanising of indiarubber goods by dipping them into the liquid and subsequently drying them (usually in a current of hot air) causes development of carbon bisulphide fumes in considerable quantity, especially if the articles to be dried are laid on shelves or hung up in the workroom, a procedure which should never be permitted. Drying must be carried out under local exhaust ventilation. All vessels holding carbon bisulphide used for dipping can be placed in a wooden channel above the dipping vessels, provided with openings for manipulation, and connected with an exhaust system. The following are the German Imperial Regulations, dated March 1, 1902, for vulcanising of indiarubber by means of carbon bisulphide: VULCANISING BY MEANS OF CARBON BISULPHIDE (Notice concerning the erection and management of industrial premises in which indiarubber goods are vulcanised by means of carbon bisulphide or chloride of sulphur.) The following regulations shall apply in accordance with paragraph 120 (_e_) of the Industrial Code: 1. The floor of such rooms as are used for the vulcanising of indiarubber goods by means of carbon bisulphide shall not be lower than the surrounding ground. The rooms shall have windows opening into the outer air, and the lower halves shall be capable of being opened so as to render possible sufficient renewal of air. The rooms shall be ventilated by fans mechanically driven. With the approval of the higher authorities permission to dispense with mechanical draught may be allowed, provided that in other ways powerful change of air is secured. With the approval of the higher authorities special ventilating arrangements can be dispensed with if the fumes of carbon bisulphide are removed immediately, at the point where they are produced, by means of a powerful draught, and in this way purity of the air be secured. 2. The vulcanising rooms shall not be used as a dwelling, or for sleeping in, or for preparing food in, or as a store, or drying room, nor shall other processes than those of vulcanising be carried on in them. No persons, except those engaged in vulcanising processes, shall be allowed in the rooms. There shall be at least 20 cubic meters (700 cubic feet) of air space allowed for each person employed therein. 3. Only such quantities of carbon bisulphide shall be brought into the vulcanising rooms as shall serve for the day’s supply. Further storage shall be made in a special place separate from the workrooms. Vessels to hold the vulcanising liquid shall be strongly made, and when filled and not in use shall be well covered. 4. Vulcanising and drying rooms shall be warmed only by steam or hot-water pipes. These rooms shall be lighted only by means of strong incandescent electric lamps. Exceptions from paragraphs 1 and 2 may be allowed by the higher authorities. 5. Machines intended for vulcanising long sheets of cloth shall be covered over (_e.g._, with a glass casing) so as to prevent as far as possible the entrance of carbon bisulphide fumes into the workrooms, and from the casing the air shall be drawn away effectually by means of a fan mechanically driven. Entrance to the space which is enclosed shall only be allowed in case of defects in the working. In cases where a covering of the machine is not practicable for technical reasons the higher authorities can, if suitable means of protection are used (especially when the machine is placed in an open hall, and provided that no person works at the machine for more than two days a week), allow of exception to the above arrangement. 6. Vulcanising of other articles (not mentioned in par. 5), unless carried out in the open air, shall be done in covered-in boxes into which the worker need only introduce his hands, and so arranged as to keep the fumes away from the face of the worker. The air must be drawn away from the box by means of a powerful draught. 7. Rule 6 shall apply in vulcanising both the outside and inside of indiarubber goods. In vulcanising the inside no worker shall be allowed to suck the fluid through with the mouth. 8. The goods after their immersion in the vulcanising fluid shall not lie open in the room, but shall either be placed under a ventilated cover or at once be carried into the drying chamber. The drying chamber or drying rooms in which the wares are exposed to artificial heat immediately after vulcanising shall be so arranged that actual entrance into them for the putting in or taking out of the vulcanised goods shall not be necessary. No person shall be allowed to enter the drying chamber while work is going on. The higher authorities can permit of exceptions to this rule in the case of the drying of long rolls if sufficient protecting arrangements are made. 9. When vulcanisation is effected by means of chloride of sulphur the vessels or chambers used for holding it shall be so arranged that escape of the fumes is prevented. No person shall enter the vulcanising chamber until the air in the chamber has been completely changed; it shall not be used for purposes other than vulcanising. 10. Employment in vulcanising with carbon bisulphide or in other work exposing the workers to carbon bisulphide vapour shall not be allowed without a break for more than two hours and in no case for more than four hours in one day; after two hours a pause of at least one hour must be allowed before resumption. No person under 18 years of age shall be employed. 11. The occupier shall provide all workers employed in work mentioned in paragraph 10 with proper and sufficient overalls. By suitable notices and supervision he shall see that when not in use they are kept in their proper place. 12. Separate washing accommodation and dressing-rooms for each sex shall be provided, distinct from the workrooms, for all persons employed as stated in paragraph 11. Water, soap, and towels and arrangements for keeping the clothes put off before the commencement of work shall be provided in sufficient amount. 13. The occupier shall appoint a duly qualified medical practitioner (whose name shall be sent to the Inspector of Factories) to supervise the health of those exposed to the effects of carbon bisulphide. He shall examine the workers once every month with a view to the detection of poisoning by carbon bisulphide. By direction of the medical practitioner workers showing signs of carbon bisulphide poisoning shall be suspended from work and those who appear peculiarly susceptible shall be suspended permanently from work in processes mentioned in paragraph 10. 14. The occupier shall keep a book, or make some official responsible for its keeping, of the changes in the personnel in the processes mentioned in paragraph 10 and as to their state of health. The book shall contain— (1) The name of the person keeping the book; (2) The name of the appointed surgeon; (3) Surname, Christian name, age, residence, date of first employment, and date of leaving of every worker mentioned in paragraph 10, and the nature of the employment; (4) The date of any illness and its nature; (5) Date of recovery; (6) The dates and results of the prescribed medical examination. 15. The occupier shall require the workers to subscribe to the following conditions:— No worker shall take food into the vulcanising rooms; The workers shall use the protection afforded in paragraphs 5-7 and use the overalls in the work named; The workers shall obey the directions of the occupier given in accordance with Rule 5, paragraphs 1 and 2, Rule 8, paragraphs 1 and 2, and Rule 9, paragraph 2. Workers contravening these orders shall be liable to dismissal without further notice. If in a factory regulations already exist (paragraph 134(a) of the Industrial Code) the above shall be included. 16. In the vulcanising rooms mentioned in Rule 1 there shall be posted up a notice by the police stating— (_a_) The cubic capacity of the rooms; (_b_) The number of workers who may be employed. Further, in every vulcanising room there shall be posted up in a conspicuous place and in clear characters Rules 1-15 and the conditions in paragraph 15. Reference should be made also to the Prussian Ministerial Decree, dated February 23, 1910, on the preparation, storing, and manufacture of carbon bisulphide, and to the French Ministerial Circular, dated January 20, 1909 (Manufacture of Indiarubber). Employment of benzine and chloride of sulphur for vulcanising is, from a hygienic standpoint, to be preferred to that of the much more dangerous carbon bisulphide. The same applies also to the process of the extraction of fat. In the references made to general arrangements for the protection of workers dealing with poisons, stress was laid on the complete enclosing of extraction apparatus. This applies, of course, to extraction by means of carbon bisulphide, both on grounds of economy, health, and risk from fire. On account of the risk to health, efforts have been made to substitute other means of equal efficiency, free from danger. Such a substitute may be found in _carbon tetrachloride_. This extracts well, and dissolves grease spots (like benzine), is not explosive, is scarcely inflammable, and is less poisonous than the substances commonly used for extraction. Its employment is to be recommended on hygienic grounds, but the relatively high price may stand in the way of its use. Illuminating Gas Industry. Production of Tar and Coke (See also pp. 71-90 and 199) In illuminating gas factories imperviousness of the whole working system is especially important from an economical and hygienic standpoint, since only in this way can danger to the working staff be avoided. This applies especially to the retorts, from which no gas should be allowed to escape. If the exhaust is working satisfactorily this should not be possible, as the pressure of the gas in the retorts during distillation will be a negative one. Correct regulation of pressure is thus of the greatest importance in the prevention of poisoning in gas works. Further, special precaution is necessary in operations with gas purifying material containing cyanogen, since otherwise the workers suffer from the gases developed from the gas lime. Work with gas purifying material should be so arranged that injurious gases are carried away by suitable ventilating arrangements. Consideration for the neighbourhood forbids their discharge into the open air, and forbids also operations with the gas purifying material in the open air; therefore non-injurious removal of these gases is necessary. Quenching of the coke also should, on account of the annoyance to the working staff and to lessen nuisance to the neighbourhood, be carried out so that the fumes are drawn into the main chimney stack. In coke ovens escape of tarry constituents and of poisonous emanations are prevented by imperviousness of the apparatus, by sufficiency of the exhaust draught, and especially by passing the products of distillation, which cannot be condensed, under a fire, or by absorbing them either with water or oil. Special precautionary measures are needed further in the distillation of the washing oil, and generally escape of poisonous emanations must be prevented by the greatest possible imperviousness of the distillation system and corresponding regulation of pressure. Gas Motors (Power Gas Stations) (See also pp. 80-5) The following points, taken from an Austrian Ministerial Decree (dated December 2, 1903), for the prevention of poisoning in power gas works, may be useful: POWER GAS INSTALLATIONS In mixed gas installations (Dowson, water gas) of the older system, the way in which the gas is produced causes the whole apparatus and pipes to be under slight negative pressure, because the steam required for the process must be blown into the generator. In these works, therefore, a small special steam boiler is required and a gas receiver to store the gas. In more modern suction generator gas installations the piston is used to suck in steam and air as well as the gases arising in the generator and to draw them into the motor cylinder. Thus the whole system is kept in a condition of slight negative pressure during the process. While the suction generator gas system is working, only so much gas is produced as the motor uses for the time being, so that with this system there is no greater store of gas than is requisite. In such an installation the following rules should be borne in mind: 1. All the apparatus (gas pipes, valves, &c.) must be constructed and maintained in a completely impervious condition. Any water seals especially which may be in use must receive attention. 2. Precautions must be taken to prevent the gases from the generator passing into the coolers and purifiers when the engine is at rest. 3. Care is to be taken when the apparatus is at rest to prevent any possible subsequent escape of gas into the room where the apparatus is installed. 4. The return of explosive gas out of the gas engine into the gas pipe by failure to ignite or other accident, must be made impossible. 5. The apparatus through which the generator is charged must possess a tightly fitting double valve to prevent escape of gas into the room during charging. 6. The pipes for conducting away the unpleasantly smelling bituminous constituents in the water mixed with sulphuretted hydrogen from the scrubbers must not communicate with the workroom. 7. Precautions must be taken to minimise the danger during the cleaning of the generator (removal of ashes and slag). 8. All stop-cocks and valves are to be so arranged that their position at any time (open or shut) is clearly visible from outside. 9. Purifiers with a capacity greater than two cubic meters must be provided with appliances which make possible thorough removal of the gas before they are opened. 10. The gas washing and cleaning apparatus and pipes are to be fitted with gauges indicating the pressure existing in them at any moment. 11. When a suction gas plant is first installed and also at times when there is no gas in the pipes and plant between the generator and the engine, gas must be blown in until all air is expelled before the engine is set going. 12. During the cleaning of apparatus and pipes which, when in action, contain gas, the rooms must be thoroughly ventilated. 13. Rooms in which suction gas plant is installed must be of such a height that all the plant and its connections can be easily reached for cleaning, &c., and be capable of such free ventilation as to render impossible an accumulation of gas. 14. These rooms must be separated from living rooms by a wall without any openings in it. Emanations also must be prevented as far as possible from entering into living or working rooms situated over the gas engine. 15. Erection of apparatus for generating and purifying suction gas in cellars shall only be allowed if specially effective ventilation is provided by natural or mechanical means. Other Regulations are those of the Prussian Ministerial Decree, dated June 20, 1904, as to the arrangement and management of suction gas premises. ACETYLENE GAS INSTALLATIONS (See also pp. 85-7) The following regulations for the protection of workers in acetylene gas installations are taken from the Prussian Ministerial Decree, dated 2 November, 1897: 1. Preparation and condensation of acetylene on the one hand, and liquefaction on the other, must be carried on in separate buildings. 2. If the pressure employed for condensation of the gas exceeds eight atmospheres, this work must take place in a room set apart for the purpose. 3. Rooms in which acetylene is prepared, condensed, or liquefied shall not be used as, nor be in direct connection with, living rooms. They must be well lighted and ventilated. 4. The carbide must be kept in closed watertight vessels, so as to ensure perfect dryness and only such quantities shall be taken out as are needed. The vessels must be kept in dry, light, well-ventilated rooms; cellar rooms may not be used for storage purposes. 5. Crushing of carbide must be done with the greatest possible avoidance of dust. Workers are to be provided with respirators and goggles. 6. Acetylene gasometers must be fitted up in the open air or in a well-ventilated room, separated from the gas generator. Every gas receiver must have a water gauge showing the pressure in the receiver. 7. Between the gasometer and receiver a gas purifier must be provided so as to remove impurities (phosphoretted hydrogen, arseniuretted hydrogen, carbon bisulphide, ammonia, &c.). 8. Condensation of acetylene gas at a pressure exceeding ten atmospheres shall only be done in combination with cooling. DISTRIBUTION AND USE OF POWER AND ILLUMINATING GAS The Austrian Gas Regulations (of July 18, 1906) contain general provisions as to impermeability and security of the gas pipes and the precautions to be observed in their installation. Special directions follow as to main flues, material, dimensions, branches, and connections, valve arrangements, testing of the pipes against leakage, directions for discovering leaks, and other defects; also the nature of the branch pipes (dimensions and material), valves, cocks, syphons, water seals, and pressure gauges. In addition there are directions as to testing pipes and how to deal with escape of gas, freezing of pipes, and other mishaps. Ammonia (See also pp. 90-3 and 175) In the production of ammonia and ammonium salts (ammonium sulphate) combination of the ammoniacal vapour with the sulphuric acid is accompanied with the formation of volatile dangerous gases containing sulphuretted hydrogen and cyanogen compounds, which produce marked oppression and sometimes endanger the health of the workers. Drawing-off these fumes into the furnace (practised sometimes in small industries) is not advisable, as the sulphuretted hydrogen is burnt to sulphur dioxide; if it is burnt absorption of the sulphur dioxide should follow, or working it up into sulphuric acid (Leymann). Often these gases are freed from cyanogen compounds and sulphuretted hydrogen by means of gas purifying materials, such as are used in gas works. The whole apparatus must be impervious. Where liquids containing ammonia are used exhaust ventilation is necessary. Cyanogen, Cyanogen Compounds (See also pp. 93-5 and 195-7) Processes in which cyanogen gas can develop, require to be done under a powerful exhaust draught. In the production of cyanogen compounds possibility of the escape of hydrocyanic acid (prussic acid) has to be borne in mind. Such escape is possible in its production from raw animal products. The most careful cleanliness and observance of general measures for personal hygiene are necessary in factories in which cyanogen compounds are manufactured or handled. In crushing cyanide of potassium the workers should wear indiarubber gloves and respirators. The products should be stored in closed vessels in dry store rooms set apart for the purpose. Modern cyanide of potassium factories which work up molasses, from which the sugar has been removed, and also residuary distillery liquors, so far conform with hygienic requirements that all the apparatus is under negative pressure, so that poisonous gases cannot escape into the workrooms. Coal Tar, Tar Products (See also pp. 96-119) Care must be taken for the removal of injurious gases developed in the manipulation and use of tar (tar distillation) and in the processes of cleaning connected therewith. This can be most effectively done by carrying on the processes in closed apparatus. Hofmann describes such a factory where all mixing vessels in which the distillation products are further treated are completely closed in, so that even in mixing and running off, no contact is possible with the material. The vessels for holding tar, tar-water, &c., must be impervious and kept covered. Only the cold pitch and asphalt should be stored in open pits. The cooling of the distillation products and residues, so long as they give off poisonous and strongly-smelling fumes, should be carried out in metal or bricked receivers. Such directions find a place in the ‘Technical Instructions’ appended to the German Factory Code. Without doubt, tar is, because of its smell and for other reasons, unpleasant to handle, and the danger to health from contact with it is not a matter of indifference. Spilling of small quantities of tar during transport and other manipulations can hardly be avoided. Careful cleanliness, therefore, on the part of workers is strongly urged. It may be mentioned that if tar is covered with a layer of tar-water, treatment with acid fluids develops sulphur and cyanogen compounds, which may affect the workers. Tar water should, therefore, be separated carefully from the tar and used for the preparation of ammonia. The same remarks as to cleanliness, &c., apply in the manufacture of felt, lamp-black, and briquettes, with use of tar. Saturation of felt, and manufacture of tar plaster should be done in closed apparatus. In the production of lamp-black, even with a great number of soot chambers, there is escape of soot causing nuisance to workers and the neighbourhood. Complete avoidance of this seems to be difficult, so that measures for personal hygiene must be assured. In briquette factories it has been found useful to heat the tar by means of steam instead of by direct fire, which renders possible the use of a closed apparatus and mechanical stirring. In the distillation of tar, during the first distillation period (first runnings) unpleasant and injurious gases containing ammonia and sulphur escape from the stills. These should (according to Leymann) be carried away through closed pipes branching off from the lower end of the running-off pipe, either into the furnace (in doing which a possible back flash of flame is to be guarded against) or be subjected to purification by lime or oxide of iron (similar to that in the case of illuminating gas) with a view to recovery of ammonia and sulphur. The lower end of the distillation pipes should be U-shaped so as to form a liquid seal—the pipes for the drawing off of the gases branching off before the curve. In the later stages of distillation risk can be checked by careful cooling and imperviousness of the apparatus. Very unpleasant yellow fumes develop in great quantity when pitch is run off from the hot still. Hence hot pitch should not be run off into open pitch receptacles, but be cooled first in closed receptacles. The crude products obtained by distillation (light oil, creosote oil) are subjected to purification consisting in treatment on the one hand with alkali and on the other with acid and followed by fractional distillation. In these processes injurious fumes may develop, therefore they must—as already mentioned—be carried on in closed vessels provided with means of escape for fumes and appliances for mechanical stirring; the fumes drawn off must be led into the chimney stack. In the distillation of brown coal, of tar, and of resin, it is necessary, as in the distillation of coal tar, to insist above all on careful cooling and condensation, and thorough absorption of uncondensed gases in washing towers. Special precautionary rules are necessary to guard against the danger of entering tar stills for cleaning purposes. Such directions were approved in Great Britain in 1904 in view of accidents which occurred in this way: TAR DISTILLING The following directions[I] are approved by the Home Office and are applicable to factories in which is carried on the distillation of tar for the production of naphtha, light oil, creosote oil, and pitch. 1. During the process of cleaning, every tar still should be completely isolated from adjoining tar stills either by disconnecting the pipe leading from the swan neck to the condenser worm, or by disconnecting the waste gas pipe fixed to the worm end or receiver. Blank flanges should be inserted between the disconnections. In addition, the pit discharge pipe or cock at the bottom of the still should be disconnected. 2. Every tar still should be ventilated and allowed to cool before persons are allowed to enter. 3. Every tar still should be inspected by the foreman or other responsible person before any workman is allowed to enter. 4. The inspecting foreman on first entering any tar still or tank, and all persons employed in tar stills or tanks in which there are no cross stays or obstructions likely to cause entanglement, should be provided with a belt securely fastened round the body with a rope attached, the free end being left with two men outside whose sole duty should be to watch and draw out any person appearing to be affected by gas. The belt and rope should be adjusted and worn in such a manner that the wearer can be drawn up head foremost and through the manhole and not across it. 5. A bottle of compressed oxygen, with mouthpiece, should be kept at all times ready for use; and printed instructions as to the use of this bottle, and the method to be employed for resuscitation by means of artificial respiration should be kept constantly affixed. A draft of such instructions is appended. 6. A supply of suitable chemical respirators properly charged and in good condition should be kept ready for use in case of emergency arising from sulphuretted hydrogen or certain poisonous gases. (Granules of carbon saturated with a solution of caustic soda readily absorb sulphuretted hydrogen and may be used for charging respirators.) 7. The use of naked lights should be strictly prohibited in any portion of the works where gas of an inflammable nature is liable to be given off. 8. Each still should be provided with a proper safety valve, which should at all times be kept in efficient working condition. GASSING _Symptoms._—The first symptoms are giddiness, weakness in the legs, and palpitation of the heart. If a man feels these he should at once move into fresh warm air, when he will quickly recover if slightly affected. He should avoid exposure to cold. He should not walk home too soon after recovery; any exertion is harmful. _First Aid._—Remove the patient into fresh warm air. Send for the oxygen apparatus. Send for a doctor. Begin artificial breathing at once if the patient is insensible and continue it for at least half-an-hour, or until natural breathing returns. Give oxygen[J] at the same time and continue it after natural breathing returns. _Artificial Breathing_ (_Schäfer Method_).—Place the patient face downwards as shown in the diagrams. Kneel at the side of the patient and place your hands flat in the small of his back with thumbs nearly touching, and the fingers spread out on each side of the body over the lowest ribs (_see_ Diagram 1). [Illustration: DIAGRAM 1] Then promote artificial breathing by leaning forward over the patient and, without violence, produce a firm, steady, downward pressure (_see_ Diagram 2). Next release all pressure by swinging your body backwards without lifting your hands from the patient (_see_ Diagram 1). [Illustration: DIAGRAM 2] Repeat this pressure and relaxation of pressure without any marked pause between the movements, _about 15 times a minute_, until breathing is established. In my opinion as expressed in the general discussion, use of breathing apparatus (smoke helmets) with oxygen is strongly advisable; these implements must be put on before entering the still. In creosoting wood, opening the apparatus and taking out the steeped wood should only be done when the apparatus is sufficiently cooled, as otherwise injurious fumes escape. In heating asphalt unpleasant fumes arise which should be drawn off into a furnace, or absorbed by a condenser charged with oil (Leymann); open pans should be avoided, as injurious to workers. Organic Dye-stuffs, Coal-Tar Colours. (See also pp. 107-19 and 204-15) The hygienic measures to be adopted for the prevention of industrial poisoning in coal-tar colour factories are chiefly concerned with the poisonous nature on the one hand of the raw material (benzene, toluene, &c.) and on the other of the intermediate products (nitrobenzene, aniline, toluidine, &c.) and the subsidiary substances (chlorine, acids, especially nitric acid, &c.,) used. The most important measures are as follows: In purifying the raw materials (benzene, &c.) the distillation requires to be done under effective cooling and in impervious apparatus. If injurious solvents are employed (such as pyridine in the production of anthracene) the manipulations should be performed in closed apparatus if possible, under negative pressure. The fumes exhausted should be carefully condensed by cooling or absorbed by a spray of water or oil. In view of the poisonous nature of benzene, the apparatus, stills, receivers, tanks, tank waggons, &c., should only be entered for the purpose of cleaning or repairing after preliminary thorough removal of all residue of benzene, complete isolation from all similar apparatus near, and thorough ventilation. Workers entering the stills, &c., should always be equipped with breathing apparatus (smoke helmets) and with a supply of oxygen. Other aids, such as safety belts which are held by helpers, are not here advocated in view of the often sudden fatal poisoning, especially as the rescuer is easily induced to spring to the assistance of his unfortunate mate without the necessary equipment. The frequency of such accidents calls urgently for the use of breathing apparatus. In the manufacture of _diazo-_ and _nitroso-compounds_ and generally in nitrating operations poisonous nitrous fumes are developed. By reduction in an acid solution, acid fumes and singularly pungent-smelling compounds can be given off. If reduction by means of tin is practised, the arsenic in the tin can cause evolution of the extremely poisonous arseniuretted hydrogen gas. In sulphonating, sulphur dioxide can develop; and sulphuretted hydrogen gas on heating with sulphur or sulphide of sodium. All manipulations should take place in tightly closed-in apparatus provided with exhaust, and the gases drawn off should be absorbed or effectively carried away. In the case of many injurious gases it is not sufficient merely to conduct them into the flue; they ought to be condensed and got rid of. Thus acid fumes (nitrous fumes, sulphur dioxide, hydrochloric acid vapour, chlorine gas) are neutralised by water or milk of lime, or a solution of soda; ammonia or alcohol by water; sulphuretted hydrogen and arseniuretted hydrogen by lime and oxide of iron; aniline, &c., by dilute acids. Production of _nitrobenzene_, by nitrating benzene requires to be done in closed apparatus, provided with mechanical agitators. In the subsequent separation of the nitrating acids from the resulting nitro-compounds, escape of vapourised nitro-compounds can scarcely be avoided even if closed apparatus is used. Provision, therefore, must be made for abundant ventilation of the workrooms. The reduction of the nitro-compounds (nitrobenzene, nitrotoluene) to aniline (toluidine) must similarly take place in closed agitating vessels. Introduction of the iron filings and sulphuric or hydrochloric acids, also the subsequent saturation with lime, and driving over of the aniline, &c., with steam, and collection of the distillate, must take place in completely closed apparatus. Nevertheless, escape of small quantities of aniline is very difficult to prevent unless ample ventilation is provided. In the production of _fuchsin_ by heating aniline hydrochloride (toluidine, red oil) with nitrobenzene (formerly arsenic acid) in closed vessels, furnished with mechanical stirring apparatus the aniline remaining unconverted after the melting escapes in the form of steam carrying aniline fumes, even with careful condensation, so that thorough ventilation and the other general measures for the protection of workers set forth on pp. 242 _et seq._ are required. Marked injury to health and distress to workers through acid fumes are sometimes caused by the denitration of the waste mixture of sulphuric and nitric acids in the nitrating process, that is, by the separation of nitric acid from the acid mixture. This denitration takes place usually in the Glover towers of the lead chamber system which is often associated with the manufacture of aniline. The mixed nitro-compounds of the waste acids, however, are often not completely condensed, but pass through the chambers and Gay-Lussac towers and escape into the air, whence arises the constant smell of nitrobenzene in aniline factories (Leymann). In the production of _naphthylamine_ and recovery of chlorinated products, escaping chlorine should be led into chloride of lime chambers, hydrochloric acid fumes into towers to be absorbed by water and milk of lime or a solution of soda. In aniline factories danger can scarcely be wholly avoided, as the workers, on the one hand, come into contact with poisonous substances, nitrobenzene, aniline, &c., and on the other hand, in spite of all technical hygienic measures, can hardly help breathing in some of the aniline. Apart from the technical regulations, therefore, there must be insistence on cleanliness of the workrooms, personal cleanliness on the part of the workers (washing, baths, working suits, cloak-rooms, &c.). Besides this, contact with aniline, nitrobenzene, &c., wetting of the body and clothes with these substances, and, especially spilling, splashing, and scattering these fluids must be carefully avoided. The workers require to be suitably instructed as to the symptoms of nitrobenzene and aniline poisoning, and the right steps to take, if poisoned. The oxygen apparatus must always be at hand, ready for use; the workers must be instructed how to use it. Further, workers, especially those newly employed, must be under supervision in order that assistance may be rendered them on the first signs of poisoning; medical assistance ought to be within easy reach. Workers also should know of the tendency of aniline to cause cancer of the bladder. Precautions against the poisonous nitro-derivatives of benzene (nitrophenol, picric acid, &c.), which are in the form of poisonous dust, must take the form of entirely closed-in grinding and packing apparatus, or, at all events, removal of the dust at its source. Among official regulations may be mentioned the Prussian Ministerial Edict, dated December 18, 1908, as to purification and storage of benzene, and further the Regulations dated December 13, 1907, and December 30, 1908, in force in Great Britain for the manufacture of nitro- and amido-derivatives of benzene, and the manufacture of explosives with use of dinitrobenzene or dinitrotoluene. VI _PREVENTIVE REGULATIONS—THE EXTRACTION OF METALS (SMELTING WORK IN GENERAL)_ Danger is incurred when the furnace leaks, a condition which generally occurs in the course of time, or if gases escape during the necessary manipulations through the working doors. This can be avoided by maintaining the walls in as air-tight a state as possible; but as very small leakages are almost unavoidable the best course is to so regulate the draught in the furnace (by means of fans) that a slight negative pressure always exists in it. Naturally, poisonous gases escaping from the furnace such as sulphur dioxide, carbonic oxide, carbon dioxide, and hydrocarbons require to be drawn away and rendered harmless. This can often be done by merely conducting them into the main flue. Gases containing carbonic oxide possess high heating capacity, and their escape can usually be prevented by suitable cupola bells. They can be led away in impervious conduits and utilised for heating purposes or for driving gas engines. Entering the flues for cleaning or repairing purposes is especially dangerous; and as it is difficult to isolate one portion entirely from another, such operations might well be carried on by persons equipped with breathing apparatus (smoke helmets or oxygen apparatus). In roasting operations handwork can be largely replaced by furnaces worked mechanically. If the gases generated are rich in sulphur dioxide they can be utilised for the manufacture of sulphuric acid or for the production of liquid sulphur dioxide either directly or after concentration; if not, they must be rendered harmless by treatment with milk of lime in absorption towers. Other methods of rendering the sulphur dioxide (unsuited for manufacture of sulphuric acid) harmless depend on treatment with minerals containing calcium carbonate, or magnesium or aluminium hydrate, sodium sulphide, &c. Sometimes the sulphurous gases are led into blast furnaces containing oxide of iron and coal (so as to form sulphide of iron) or are absorbed by means of moist scraps of sheet iron or brown coal or peat briquettes. Use of chlorine compounds in the extraction of metals from ores (silver, copper) causes evolution of chlorine and hydrochloric acid vapour. These should be dealt with in absorption towers. Metallic fumes are collected by suitable condensing arrangements. Flue dust is retained in flue dust chambers, but in the cleaning of such condensing flues and chambers danger to the workers is considerable and they should be equipped with respirators, working suits, &c. Personal hygiene must be insisted on. Iron (See also pp. 146-51) In blast furnace work, industrial poisoning occurs mainly from escaping gases rich in carbonic oxide. They may also contain sulphur dioxide and cyanogen compounds. The high proportion of carbonic oxide, however, makes these gases valuable and serviceable, because of their great heating value. They are, therefore, now led away and utilised, the furnace being closed by a cupola bell only opened by means of a mechanical contrivance when charging is necessary; while this is being done the ignited blast furnace gases pour out, and the workers retire from the opening, so that danger to them is avoided. The construction of a blast furnace with a cupola bell can be seen in fig. 29. The blast furnace gases are conducted away by an opening in the side, and pass along special pipes to be utilised, after having gone through a purifying process mainly for the removal of flue dust, &c. The gases serve partly for the heating of the blast for the furnace itself, and partly for driving the gas engines which serve the electrical power apparatus, electric lighting, &c., in the works. Through the rational utilisation of the blast furnace gases, the workers are protected from their injurious action during the working of the furnace. Serious gas poisoning, however, occurs not infrequently to workers who have to enter the gas mains for cleaning purposes. Workers, therefore, should only be permitted to enter the flues, &c., a considerable time after the process has been stopped and after as complete and thorough a ventilation of the system as is possible. Any portion of the gas system which is to undergo cleaning must be completely isolated. Ventilation is best effected by the introduction of compressed air. Thus a foundry (in the Duisburg district) has provided all its cellars and passages, through which gas pipes pass, and which must be entered during repairs, with compressed air pipes. It is, however, advisable that gas conduits should only be entered by workers equipped with breathing apparatus and oxygen supply. Naturally adequate instruction of workers and training in first aid are necessary, as well as a sufficient supply of oxygen in constant readiness. Injurious gases can escape from the furnace during tapping and slag running; poisonous gases with a disagreeable odour, from presence of sulphuretted hydrogen, also arise in granulating the slag, that is, when the fluid slag is led into water for subsequent use in preparation of cement. These gases should be collected by hoods, and be carried away as far as possible. In the manufacture of _steel_ by the _Bessemer_ or _Thomas-Gilchrist_ process, the dark smoke arising out of the converter during the blowing operation should be drawn off (led into flues), as it is injurious to health. In the _Martin_ furnaces poisoning may occur, especially when the gas flues are entered after cessation of work. In letting out the gas in order to stop the furnaces, the gas and air valves must first be closed and the outlet valves for gas be opened only after the pipes have been filled with steam. Steam is to be driven through until the pipes are quite free from gas, and the system only entered after it has become thoroughly cooled. If need arises for entering portions of the system while neighbouring parts are still filled with gas, the workers employed require to be provided with breathing apparatus and smoke helmets. In the transport of _ferro-silicon_ several cases of poisoning have occurred. Cautionary regulations, therefore, relating to this work have been found necessary. Such directions are contained in the police regulations of the Prussian Minister of Trade and Industry respecting the transport on the Rhine of corrosive and poisonous substances (dated September 29, 1910). It is prescribed: (1) that ferro-silicon be packed in strong watertight cases of wood or metal; (2) that on the cases be inscribed, legibly and indelibly, the notice ‘Ferro-silicon. To be kept dry! With care!’ (3) that the substance be delivered dry and in dry cases; (4) that the cases be stored in airy places on the deck of the ship in such a manner that they are protected from wet. Further, care is to be taken that the storage on ships is done in such a way that possible damage to the material in which it is packed entails no risk. The harbour authorities where loading or landing takes place can deal with special cases as they think fit. International regulation as to transport of ferro-silicon in the spirit of the above regulations would be most desirable in view of the oversea trade in this substance.[K] Lead (See also pp. 120-40 and 177-82) For protection against lead poisoning, the most widely spread of the slow industrial poisonings, all those measures are of moment which we have described in our general discussion on protection against danger from poison in industries, both personal and general. Personal hygiene, especially careful washing after work, prohibition of eating in workrooms, suitable working clothes, provision of cloak rooms, meal rooms, baths, &c., are important and effective measures for the protection of workers against industrial lead poisoning. The worker should naturally be adequately instructed as to the risk. Appropriate printed notices are especially adapted for this purpose. Further, selection of workers should be made under medical supervision. Workers who suffer from specific disease which, if associated with lead poisoning, may prove dangerous, should be excluded from all contact with lead. Among such illnesses must be reckoned tuberculosis in all its forms, alcoholism, epilepsy, tendency to mental disease (nervous disposition, hysteria, neurasthenia, &c.), rheumatism, and disease of the kidneys. Overtime work undoubtedly increases risk; therefore working hours should be shortened as much as possible, and handwork replaced by machine work where possible. Young persons and women especially should be excluded from work in lead. Alternation of employment also is beneficial and essential in very dangerous lead work, because the poison accumulates in the body and only during intervals wherein absolutely no poison can be absorbed has it time to be eliminated. Periodical medical examination by a surgeon is of great value with systematic entry of the results of examination in a health register. As bearing on this, early diagnosis is of the greatest importance, so that workers in whom the first signs of lead poisoning appear may at once be suspended or transferred to other work. Lead workers should take suitable nourishing food and avoid particularly alcoholic excess. When the danger is due to fumes or dust in the air the measures prescribed on pages 242-55 apply, particularly those which aim at keeping the workrooms and the air in the factories free of them by locally applied exhaust ventilation. In order to replace or reduce the use of lead we strongly advocate the use of non-poisonous, or at any rate less poisonous, substances, where this can be done without technical difficulties, as, for instance, carborundum discs instead of lead in polishing of precious stones, leadless glaze in pottery for lead glaze (so far as this is possible, as to which see page 319), beds free of lead (in different industries) for lead beds. In a number of cases, however, such substitution is impracticable on technical grounds or can only partially be carried out, as, for example, in letterpress printing and in the paint and colour industry, in which the prohibition of lead has often been repeatedly urged. So far, unfortunately, it must be admitted that repeated attempts to find a non-poisonous substitute for lead colours, especially for white lead, of equal value technically, have not succeeded. Endeavours have been made to substitute for lead, zinc preparations (zinc white, lithopone, &c.), but hitherto (in regard to durability, opacity, &c.) with incomplete success. Mention must be made of the measures based upon the relatively non-poisonous nature of lead sulphide. Lead sulphide is, in spite of various assertions to the contrary, practically non-poisonous; a fact attributable to its insolubility in water and weak acids. As lead sulphide is the only non-poisonous lead compound it is a duty to take advantage of this fact for purposes of lead prophylaxis. Attempts with this end in view were made by the introduction of sulphur soaps in lead factories. Soaps containing in large quantity soluble alkaline sulphides convert lead compounds adhering to the skin into black lead sulphide. The lead compounds are in this way made harmless, and besides this the worker is impelled to remove the staining by washing. Such a sulphur soap has been brought into the market under the name of akremnin soap, but does not enjoy special popularity with the workmen on account of its unpleasant smell. The struggle against the risks of lead employment has been going on ever since efforts for the protection of workers were commenced. The International Association for Labour Legislation has made valuable inquiries in this direction. The question of lead poisoning had been repeatedly discussed by this Association and its branches in various countries. The International Labour Bureau also took up the issue and in 1906—supported by the Institute for General Welfare in Frankfurt a-M.—offered a prize for the best treatise on the prevention of industrial lead poisoning. The outcome of this competition was the volume compiled by Leymann, ‘Die Bekämpfung der Bleigefahr in der Industrie’ (published by Fischer, Jena, 1908). In connection with the resolution adopted at the third Congress of the International Association for Labour Legislation the Union of Social Reform (as the German branch is called) addressed the Federal Council on the white lead question, the chief points insisted upon being the need for: (1) regulations for the house painting industry in pursuance of Section 120 of the Factory Code; (2) report by the Imperial Health Office on the practicability of substitutes for lead; (3) exclusion of lead colours from use in the painting of public buildings; and (4) treatment of lead poisoning by the State Insurance Office as an accident entitling to compensation. These demands were supported by the central office of the Society for Promoting the Welfare of Workers, which had as far back as its seventh conference in 1898 occupied itself with the question of dangerous trades and especially, at its conference in 1905, taken up the subject of the protection of workers against industrial poisoning. In Germany these efforts resulted in the passage of a number of Imperial Regulations for separate lead industries. In other countries similar action was set on foot. In Austria, where the subject is of special importance in view of the part played by lead in the home industries, the Government undertook to improve the conditions in industries attended with risk of lead poisoning. For this purpose the Statistical Office of the Ministry of Commerce and Labour has, since 1904, carried out extensive inquiries into lead and zinc smelting works, paint and colour factories, the painting and varnishing trades, letterpress printing, and the ceramic industry. The results are contained in the volume ‘Lead Poisoning in Smelting Works and Industries Generally’ (published by Hölder, Vienna). As in Germany and Austria, so also in Great Britain, France, Switzerland, Belgium, and the Netherlands, regulations in various lead industries were enforced after previous official inquiry and report. A general code, however, affecting all lead industries has only been published in one or two states. And yet this would, in my opinion, be of very great practical value as it is hardly possible to regulate each single branch of industry. In Germany the Regulations dated May 26, 1903, dealing with lead colours are certainly comprehensive, but relate primarily to paint factories, and are not, therefore, a general Order in the sense indicated. In Saxony the decree of June 27, 1901, made notification of lead poisoning compulsory, and in the subsequent decree of April 16, 1909, prescribed general measures against lead poisoning. In Switzerland single cantons have made general regulations. In France, by a decree dated April 23, 1908 (in pursuance of the general law of June 12, 1893), all industries attended with risk of lead poisoning were brought under Regulation. We give the provisions of this interesting decree, as it is a good example of the kind of Regulations we have in mind. DECREE OF THE PRESIDENT OF THE FRENCH REPUBLIC (APRIL 23, 1908) RELATING TO CERTAIN INDUSTRIES IN WHICH LEAD IS USED 1. In the lead industries hereinafter mentioned, viz.: smelting, cupellation of argentiferous lead, manufacture of accumulators, glass-making, manufacture and use of lead enamels, manufacture of pottery, decoration of porcelain or faience, ceramic chromo-lithography, manufacture of lead alloys, oxides, salts and colours—employers, directors or managers are required, apart from the general measures prescribed by the Decree of 29 November, 1904, to take special measures for protection and health as set forth in the following sections. 2. Lead melting pots shall be erected in an airy place separated from the other workrooms. Hoods or other means for the effectual removal of fumes shall be provided:— (_a_) Over the openings for the run of lead and slag in lead smelting. (_b_) Before the furnace doors in the manufacture of lead oxides. (_c_) Above the pots for melting lead or its alloys, in the other industries enumerated in Section 1. 3. All work with oxides and other compounds of lead capable of producing dust shall be done as far as possible when in a damp condition. When this work cannot be done in the presence of water or other liquid, it shall be carried out by mechanical means, in covered air-tight apparatus. If it is impossible to conform to the requirements of either of the first two paragraphs of this section, the work shall be done under a strong draught so arranged that the harmful products may be intercepted by apparatus suitably placed. Finally, if none of these systems is possible the workmen shall be supplied with respirators. 4. Oxides and other compounds of lead, whether dry or damp, in suspension or solution, shall not be handled with the bare hand. The employer shall at his own expense provide the workers in these operations with either gloves made of impervious material such as indiarubber, or suitable appliances, and shall cause them to be kept in good repair and frequently cleaned. 5. Tables on which these products are handled shall be covered with some impervious material, kept in a perfectly water-tight condition. The same requirement applies to the floors of the workrooms, which shall also be kept damp. The floor shall be slightly sloped towards a water-tight receptacle for collecting the lead substances which are washed down. The work shall be so arranged that there shall be no splashing. The tables, floors and walls shall be washed at least once a week. 6. Without prejudice to the requirements of section 3, the grinding and mixing of lead products, and the use of them in dusting shall be effected in special places with active ventilation. If the materials cannot be damped, the workers shall be provided with respirators. 7. Pottery shall not be dipped with bare hands in solutions containing litharge, red lead, galena or white lead in suspension. 8. No food or drink shall be brought into the works. 9. Employers shall, at their own expense, provide and maintain for the use of the workers, overalls or clothing for use during work only, in addition to gloves and respirators. 10. In a part of the building separated from the workrooms, there shall be provided for the use of the workers exposed to lead dust or fumes, a cloak room and lavatory kept in good order, provided with basins or taps in sufficient number, a plentiful supply of water, soap and a towel for each worker replaced at least once a week. The cloak rooms shall be provided with cupboards or drawers with locks or padlocks, the ordinary clothing being kept apart from the working clothes. 11. A warm bath or shower bath shall be provided each week for the workers exposed to lead dust or fumes. A warm bath or shower bath shall be provided every day after work, for each worker employed, either in emptying or cleaning the condensing chambers and flues, in repairing furnaces in lead works, in carrying lead corrosions from the beds in white lead factories, in packing red lead, in grinding lead enamels and in dry dusting. 12. Employers are required to exhibit, in a conspicuous position in the works, regulations imposing on the workers the following obligations:— To use the appliances, gloves, respirators, and working clothes placed at their disposal. Not to bring into the works either food or drink. To pay great care, before each meal, to the cleanliness of the mouth, nose, and hands. To take the baths weekly or daily as provided in section 11. 13. The Minister of Labour may, by Order made with the advice of the Consultative Committee for Arts and Manufactures, exempt an establishment for a specified period, from all or part of the requirements of Regs. 2ᵃ, 2ᵇ, 2ᶜ, 5² and 6¹ in any case where it is found that observance of these requirements is practically impossible, and that the health and safety of the workers are assured by conditions at least equivalent to those prescribed in the present Order. 14. Subject to additional postponements which may be granted by the Minister in pursuance of Section 6 of the Act of 12th June, 1893 (as amended by that of 11th July, 1903), the delay required for the carrying out of the alterations necessitated by the present Decree is limited to one year from the date of its publication. 15. The Ministry of Labour is charged with the administration of this Decree. This decree was supplemented by further noteworthy additions requiring medical supervision in lead industries as follows: DECREE OF DECEMBER 28, 1909, ORGANISING MEDICAL SERVICE IN INDUSTRIES EXPOSING THE WORKERS TO RISK OF LEAD POISONING 1. In premises in which the processes enumerated in Regulation 1 of the Decree of April 23, 1908, are carried on medical attendance as prescribed below shall be provided. 2. A surgeon appointed by the occupier shall examine the workers and enter the results of examination required in Regulations 3 and 4. The examinations shall be paid for by the occupier. 3. No person shall be employed in work mentioned in Regulation 1 of the Decree of April 23, 1908, without a certificate from the surgeon stating that he is free from symptoms of lead poisoning and of illness which might render him specially susceptible. 4. No worker shall remain at the same employment unless the certificate is renewed one month after commencement of employment and subsequently at quarterly intervals. In addition to the periodical examination the occupier shall give an order on the surgeon to every workman declaring himself to be ill from his employment or who desires to undergo medical examination. 5. A special Register open to the Factory Inspector shall be kept containing the following particulars of each worker: (1) Dates and duration of absence on account of illness of any kind; (2) Dates of medical certificates for such illness, the notes made by the surgeon and the name of the surgeon furnishing them; (3) Instructions given by the appointed surgeon in pursuance of Regulations 3 and 4 above. Lead Smelting Works (See also pp. 122-31) As the fumes in lead smelting works contain a high proportion of lead, all apparatus, especially furnaces and working doors, should be provided with efficient exhaust ventilation and all flues, furnaces, and other apparatus be as airtight as possible. Where lead dust is created exhaust ventilation locally applied is necessary. Two of the most important preventive measures are personal cleanliness and alternation of employment. Dust arising in the furnaces and borne along by the furnace gases together with arsenical fumes and dust must be deposited in flues or chambers. In view of the importance of proper instruction of smelters as regards the danger we quote the warning note prepared by the Institute for Industrial Hygiene, Frankfurt a.-M., which deserves wide circulation. LEAD LEAFLET FOR SMELTERS _How does Lead Poisoning arise?_ The danger of lead poisoning in lead, spelter and other smelting premises can be avoided if due care is observed. Lead poisoning occurs when lead enters the system. This takes place by breathing dust and fume containing lead, or by eating and drinking, smoking, snuff taking and tobacco chewing if food or tobacco is taken into the mouth with dirty hands and dirty face and beard. No one is immune from lead. Lead accumulates in the body of careless persons and he who is not sick to-day can be so to-morrow or after weeks or months. _How can Plumbism be avoided?_ All smelters must observe cleanliness. In this respect they should see to the following points: 1. It is to their interest to see that the exhaust ventilation is kept in order and that the Special Rules or Regulations are exactly followed. Further, special clothing should be worn, the mouth and nose should be covered, and the floors sprinkled. 2. It is especially important that in intervals and at the close of work the mouth, face, beard, and hands should be carefully cleaned. Food should not be eaten or the premises left without putting on fresh clothes and thoroughly washing or, still better, bathing. When drinking, the edge of the drinking glass should not be fingered with dirty hands. Especially important is it that the teeth should be cleaned and the mouth washed out. 3. During work smoking, snuff taking, and tobacco chewing, which invariably convey lead into the mouth, should be given up, as it is impossible to prevent the hands getting contaminated with lead. Lighting the pipe with glowing lead ashes is in the highest degree dangerous from the risk of inhaling lead fume. The body must be strengthened to withstand the action of lead. Moderation in drinking, especially avoidance of spirits, should be observed. Alcoholic subjects succumb to lead poisoning much more readily than the temperate. Food should be abundant and rich in fat, for example milk and bacon. Thick soups are excellent before work. Work should never be begun on an empty stomach. And lastly as much fresh air as possible. Walking, athletics, work in the garden and field will help to keep off many an attack. If anyone thinks that he is suffering from lead poisoning he should at once in his own and his family’s interest see the doctor of his sick club. The following are the GERMAN IMPERIAL REGULATIONS FOR LEAD SMELTING WORKS, DATED JUNE 16, 1905 _General Regulations_ 1. Workrooms in which lead ores are roasted, sintered, or smelted, pig lead produced and submitted to further treatment, distillation of rich lead (bullion cupellation) litharge, red lead, or other oxides of lead prepared, ground or sieved, stored or packed, or zinc skimmings distilled, shall be roomy, high, and so arranged that a sufficient constant exchange of air takes place. They shall be provided with a level and solid floor to allow of easy removal of dust by a moist method. The walls shall be smooth so as to prevent collection of dust; they shall be either washed down or lime washed at least once a year. Provided that this shall not apply in the case of calcining sheds with wooden walls. 2. An abundant supply of good drinking water, protected against contamination from dust, shall be provided for the workers on the furnaces and smelting pots, and in such close proximity to them, that they can obtain it at any time without having to go into the open air. Arrangements for sprinkling the floors shall be provided near the furnaces. The floors of the rooms mentioned in paragraph 1 shall be wet cleansed at least once daily. 3. Prepared (i.e. concentrated) lead ores and leady smelting products, unless moist, shall not be crushed except in an apparatus so arranged as to prevent as far as possible penetration of dust into the workrooms. Provided that this shall not apply to calcined material from converters. Sacks in which lead ores and materials containing lead have been packed shall not be freed from dust and cleaned except in a dust-proof apparatus or by washing. 4. Materials containing lead for charging the blast-furnaces, if they are oxides and form dust, shall be damped before they are mixed with other materials, stocked on the feeding floor, or charged into the blast-furnaces. Provided that this shall not apply in the case of calcined material from converters. 5. Dust, gases, and lead fumes, escaping from furnaces, and converters, tapping spouts, tapping pots, drain sump, slag pots, slag cars, or slag channels, and from glowing residues taken from the furnaces, shall be caught as near as possible to the point of origin and removed harmlessly. Dust collecting chambers, flues, as well as furnaces which have been ‘blown down,’ shall not be entered by workmen unless sufficiently cooled and ventilated. _Special Regulations for such parts of a factory where lead colours are prepared_ 6. In grinding, sieving and packing dry leady materials, in charging, and emptying litharge and red lead furnaces, in collecting the red lead and similar operations in which leady dust is developed, exhaust arrangements shall be provided for preventing the entrance of dust into the workrooms. 7. Apparatus producing leady dust, if their construction and manner of use does not effectually prevent evolution of dust, shall have all cracks protected by thick layers of felt or woollen material, or by similar means, so as to prevent the entrance of dust into the workrooms. Apparatus of this character shall be provided with arrangements for preventing compression of air in them. They shall only be opened when the dust in them shall have completely settled, and they are absolutely cool. _Special arrangements in force for the distillation of zinc skimmings_ 8. Proposed new furnaces for the distillation of zinc skimmings (for which according to pars. 16 and 25 of the Industrial Code a special permission is required) shall be so arranged that (1) there shall be at least a clear space of 10 feet in front of the charging opening; (2) any passages under the distillation rooms shall be roomy, at least 11½ feet high in the centre, light and airy. 9. Dust, gases, and fumes arising from the zinc skimmings distillation furnaces shall be collected as near as possible to the point of origin, and carried outside the smelting room. The entrance of gases from the fires into the smelting room shall be prevented as far as possible by suitable arrangements for drawing them off. 10. Sieving and packing of by-products obtained in the distillation of zinc skimmings (poussière, flue dust) shall not be done except in a special room separated from the other workrooms, and complying with the requirements of Reg. 1. Sieving shall only be done in an apparatus so constructed that dust shall not escape. _Employment of workers._ 11. Women and young persons shall not be employed or permitted in rooms mentioned in Reg. 1, in flue dust chambers, or dust flues, or in the removal of flue dust. 12. No person shall be newly employed in rooms mentioned in Reg. 1, in flue dust chambers, or dust flues, or in the transport of flue dust, without a certificate of fitness from the surgeon appointed by the higher authorities. These certificates shall be collected and shown to the Factory Inspector and Appointed Surgeon on request. 13. No person shall be employed in charging blast furnaces, apart from mere labouring work on the floors, for more than eight hours daily. The same shall apply in the case of workmen employed in the inside of furnaces when cool, or in emptying flue dust chambers, or dust flues which contain wet flue dust. No person shall be employed in cleaning out, from inside, flue dust chambers, or dust flues containing dry flue dust for more than four hours daily; and including emptying and work of transport of this kind altogether no longer than eight hours daily. Other workers in rooms specified in Reg. 1 shall not work more than 10 hours in 24, exclusive of mealtimes. Exception to this is allowed in the case of those workers who are employed for the purpose of a weekly change of shift, and for whom exception as to Sunday employment is permitted by Imperial Decree. _Clothing, overalls, lavatory accommodation, &c._ 14. The occupier shall provide for all persons employed in cleaning out flue dust chambers, dust flues, repairing of cooled furnaces, grinding, sieving and packing of litharge, red lead, or other lead colours, complete suits of working clothes, including caps and respirators. 15. Work with lead salts in solution shall not be done except by workers who either grease their hands or are provided with impermeable gloves. 16. The suit of clothes, or overalls, provided in Regs. 14 and 15, respirators and gloves, shall be provided in sufficient amount and in proper condition. The occupier shall see that they are always suitable for their purpose, and are not worn except by those workers for whom they are intended; and that they, at stated intervals (the overalls at least once a week, the respirators and gloves prior to use), are cleaned, and during the time that they are not in use are kept in a place specially reserved for each article. 17. A lavatory and cloak room shall be provided for the use of the workmen in a part of the building free from dust. Separate from it there shall be a dining-room. These rooms must be kept free from dust and be warmed during the winter. In a suitable place provision shall be made for warming the workers’ food. Water, soap, and towels, and arrangements for keeping separate the overalls from other clothing taken off before the commencement of work shall be provided in sufficient amount in the lavatory and cloak room. The occupier shall afford opportunity for persons engaged in cleaning out flue dust chambers, dust flues, and the cooled furnaces, to take a bath daily after the end of the work, and for those handling oxides of lead, at least once a week, during working hours inside the works. The bathroom shall be warmed during the winter. 18. The occupier shall place the supervision of the health of the workers in the hands of a surgeon, appointed by the higher authorities for this purpose, whose name shall be sent to the Inspector of Factories. The surgeon shall examine the workers at least once a month in the factory, with a view to the detection of symptoms of lead poisoning. The occupier shall not employ persons suspected by the surgeon of having contracted lead poisoning in the processes mentioned in Reg. 1 or in cleaning out flue dust chambers, dust flues, or furnaces when cold, or transport of the flue dust, until they are quite well. Those who appear peculiarly susceptible shall be permanently suspended from working in these processes. 19. The Health Register shall be shown to the Factory Inspector and Appointed Surgeon on demand. (Similar to Reg. 15 of Spelter Regulations.) 20. The occupier shall require the workers to subscribe to the following conditions:— (1) Food must not be taken into the workrooms. Meals may only be taken outside the workrooms. (2) Workmen must only enter the meal room to take their meals or leave the factory, after they have taken off their overalls and carefully washed their face and hands. (3) Workmen must use the overalls, respirators and gloves in those workrooms and for the particular processes for which they are given them. (4) Cigar and cigarette smoking during work is forbidden. (5) A bath in the factory must be taken every day at the close of their work by those engaged in the emptying and cleaning of flue dust chambers, flues, and furnaces when cold, and by those employed on oxides of lead once a week. Provided that this shall not apply in the case of workmen exempted by the appointed surgeon. Workers contravening these orders will be liable to dismissal without further notice. 21. In every workroom, as well as in the cloak room and meal room, there shall be posted up by the occupier, in a conspicuous place and in clear characters, a notice of these regulations. The occupier is responsible for seeing that the requirement of Reg. 20 (1) is obeyed. He shall make a manager or foreman responsible for the precise carrying out of Reg. 20 (1) (2) and (5). The person thus made responsible shall see to the carrying out of the regulations and for the exercise of necessary care as prescribed in par. 151 of the Factory Act. 22. No work in a lead smelting works shall be commenced until notice of its erection has been sent to the Factory Inspector. After receipt of the notice he shall personally visit to see whether the arrangements are in accordance with these regulations. 23. These regulations come into force on 1st January, 1906. Where structural alterations are necessary for the carrying out of Regs. 1, 5 (1), 6, 9, 10 and 17, the higher authorities may allow an extension of time to a date not later than January 1st, 1908. If it seems necessary on strong grounds of public interest, the Council (Bundesrath) may extend the time in particular works until 1st January, 1913, and until then allow exceptions from the regulations as regards Reg. 13 (1) and (2). Accumulator Factories [Dr. Rambousek gives a very brief synopsis of the German Imperial Regulations in force for this industry and mentions that in Great Britain the Regulations of the Secretary of State dated 1903 are similar. We have printed these, as the code is fairly representative of the English Regulations for (1) smelting of metals; (2) paints and colours; (3) tinning of hollow ware; (4) yarn dyed with chromate of lead; (5) vitreous enamelling; and the special rules for (6) white lead and (7) earthenware: REGULATIONS DATED NOVEMBER 21, 1903, MADE BY THE SECRETARY OF STATE FOR THE MANUFACTURE OF ELECTRIC ACCUMULATORS Whereas the manufacture of electric accumulators has been certified in pursuance of Section 79 of the Factory and Workshop Act, 1901, to be dangerous; I hereby, in pursuance of the powers conferred on me by that Act, make the following regulations, and direct that they shall apply to all factories and workshops or parts thereof in which electric accumulators are manufactured. _Definitions._—In these Regulations ‘lead process’ means pasting, casting, lead burning, or any work involving contact with dry compounds of lead. Any approval given by the Chief Inspector of Factories in pursuance of these Regulations shall be given in writing, and may at any time be revoked by notice in writing signed by him. _Duties of Occupier_ 1. _Ventilation._—Every room in which casting, pasting or lead burning is carried on shall contain at least 500 cubic feet of air space for each person employed therein, and in computing this air space, no height above 14 feet shall be taken into account. These rooms and that in which the plates are formed shall be capable of through ventilation. They shall be provided with windows made to open. 2. _Separation of processes._—Each of the following processes shall be carried on in such manner and under such conditions as to secure effectual separation from one another and from any other process: (_a_) Manipulation of dry compounds of lead; (_b_) Pasting; (_c_) Formation, and lead burning necessarily carried on therewith; (_d._) Melting down of old plates. Provided that manipulation of dry compounds of lead carried on as in Regulation 5 (b) need not be separated from pasting. 3. _Floors._—The floors of the rooms in which manipulation of dry compounds of lead or pasting is carried on shall be of cement or similar impervious material, and shall be kept constantly moist while work is being done. The floors of these rooms shall be washed with a hose pipe daily. 4. _Melting pots._—Every melting pot shall be covered with a hood and shaft so arranged as to remove the fumes and hot air from the workrooms. Lead ashes and old plates shall be kept in receptacles especially provided for the purpose. 5. _Manipulation of dry compounds of lead._—Manipulation of dry compounds of lead in the mixing of the paste or other processes, shall not be done except (_a_) in an apparatus so closed, or so arranged with an exhaust draught, as to prevent the escape of dust into the work room: or (_b_) at a bench provided with (1) efficient exhaust draught and air guide so arranged as to draw the dust away from the worker, and (2) a grating on which each receptacle of the compound of lead in use at the time shall stand. 6. _Covering of benches._—The benches at which pasting is done shall be covered with sheet lead or other impervious material, and shall have raised edges. 7. _Prohibition of employment._—No woman, young person, or child shall be employed in the manipulation of dry compounds of lead or in pasting. 8. (_a_) _Appointed Surgeon._—A duly qualified medical practitioner (in these Regulations referred to as the ‘Appointed Surgeon’) who may be the Certifying Surgeon, shall be appointed by the occupier, such appointment unless held by the Certifying Surgeon to be subject to the approval of the Chief Inspector of Factories. (_b_) _Medical examination._—Every person employed in a lead process shall be examined once a month by the Appointed Surgeon, who shall have power to suspend from employment in any lead process. (_c_) No person after such suspension shall be employed in a lead process without written sanction entered in the Health Register by the Appointed Surgeon. It shall be sufficient compliance with this regulation for a written certificate to be given by the Appointed Surgeon and attached to the Health Register, such certificate to be replaced by a proper entry in the Health Register at the Appointed Surgeon’s next visit. (_d_) _Health Register._—A Health Register in a form approved by the Chief Inspector of Factories shall be kept, and shall contain a list of all persons employed in lead processes. The Appointed Surgeon will enter in the Health Register the dates and results of his examinations of the persons employed and particulars of any directions given by him. He shall on a prescribed form furnish to the Chief Inspector of Factories on the 1st day of January in each year a list of the persons suspended by him during the previous year, the cause and duration of such suspension, and the number of examinations made. The Health Register shall be produced at any time when required by H.M. Inspectors of Factories or by the Certifying Surgeon or by the Appointed Surgeon. 9. _Overalls._—Overalls shall be provided for all persons employed in manipulating dry compounds of lead or in pasting. The overalls shall be washed or renewed once every week. 10. _Cloak and dining rooms._—The occupier shall provide and maintain: (_a_) a cloak room in which workers can deposit clothing put off during working hours. Separate and suitable arrangements shall be made for the storage of the overalls required in Regulation 9. (_b_) a dining room unless the factory is closed during meal hours. 11. _Food, &c._—No person shall be allowed to introduce, keep, prepare or partake of any food, drink, or tobacco, in any room in which a lead process is carried on. Suitable provision shall be made for the deposit of food brought by the workers. This regulation shall not apply to any sanitary drink provided by the occupier and approved by the Appointed Surgeon. 12. _Washing._—The occupier shall provide and maintain for the use of the persons employed in lead processes a lavatory, with soap, nail brushes, towels, and at least one lavatory basin for every five such persons. Each such basin shall be provided with a waste pipe, or the basins shall be placed on a trough fitted with a waste pipe. There shall be a constant supply of hot and cold water laid on to each basin. Or, in the place of basins the occupier shall provide and maintain troughs of enamel or similar smooth impervious material, in good repair, of a total length of two feet for every five persons employed, fitted with waste pipes, and without plugs, with a sufficient supply of warm water constantly available. The lavatory shall be kept thoroughly cleansed and shall be supplied with a sufficient quantity of clean towels once every day. 13. Before each meal and before the end of the day’s work, at least ten minutes, in addition to the regular meal times, shall be allowed for washing to each person who has been employed in the manipulation of dry compounds of lead or in pasting. Provided that if the lavatory accommodation specially reserved for such persons exceeds that required by Regulation 12, the time allowance may be proportionately reduced, and that if there be one basin or two feet of trough for each such person this Regulation shall not apply. 14. _Baths._—Sufficient bath accommodation shall be provided for all persons engaged in the manipulation of dry compounds of lead or in pasting, with hot and cold water laid on, and a sufficient supply of soap and towels. This rule shall not apply if in consideration of the special circumstances of any particular case, the Chief Inspector of Factories approves the use of local public baths when conveniently near, under the conditions (if any) named in such approval. 15. _Cleaning._—The floors and benches of each workroom shall be thoroughly cleansed daily, at a time when no other work is being carried on in the room. _Duties of Persons Employed_ 16. _Medical examination._—All persons employed in lead processes shall present themselves at the appointed times for examination by the Appointed Surgeon as provided in Regulation 8. No person after suspension shall work in a lead process, in any factory or workshop in which electric accumulators are manufactured, without written sanction entered in the Health Register by the Appointed Surgeon. 17. _Overalls._—Every person employed in the manipulation of dry compounds of lead or in pasting shall wear the overalls provided under Regulation 9. The overalls, when not being worn, and clothing put off during working hours, shall be deposited in the places provided under Regulation 10. 18. _Food, &c._—No person shall introduce, keep, prepare, or partake of any food, drink (other than any sanitary drink provided by the occupier and approved by the Appointed Surgeon), or tobacco in any room in which a lead process is carried on. 19. _Washing._—No person employed in a lead process shall leave the premises or partake of meals without previously and carefully cleaning and washing the hands. 20. _Baths._—Every person employed in the manipulation of dry compounds of lead or in pasting shall take a bath at least once a week. 21. _Interference with safety appliances._—No person shall in any way interfere, without the concurrence of the occupier or manager, with the means and appliances provided for the removal of the dust or fumes, and for the carrying out of these Regulations. These Regulations shall come into force on the 1st day of January, 1904. White Lead (See also pp. 131 and 132) In the manufacture of white lead processes which create dust are specially dangerous, namely, emptying the corrosion chambers, drying and grinding, transport of the material in the form of powder, and packing. The following measures are called for: emptying the chambers should only be done by men wearing respirators or equipped with breathing helmets after preliminary damping of the corrosions by means of a spray. Use of a vacuum cleaning apparatus suggests itself. Drying should be done as far as possible in stoves charged mechanically, the temperature in which can be watched from the outside; grinding must be done in closed and ventilated mills; transport of the dried material should be effected by mechanical means or vacuum apparatus, and packing should be done in mechanical packing machines. Further, cleanliness and strict discipline are essential. Alternation of employment is advisable. The question of substitutes for white lead is referred to on p. 293. Manufacture of red lead calls for precisely similar preventive measures. Charging and emptying the oxidising furnaces should be done under efficient exhaust ventilation. Conveyance, sifting, and grinding of the cooled material requires to be done in the same way as has been described for white lead. In the production of chrome colours (lead chromates) besides the danger from lead the injurious action of chrome has to be borne in mind. Regulations for white lead factories have been made in Germany, Belgium, and Great Britain. We give below the German Imperial Regulations dated May 26, 1903. REGULATIONS FOR MANUFACTURE OF LEAD COLOURS AND LEAD PRODUCTS (1) The following regulations apply to all premises in which lead colours or other chemical lead products (white lead, chromate of lead, masicot, litharge, minium, peroxide of lead, Cassel yellow, English yellow, Naples yellow, lead iodide, lead acetate, &c., are manufactured), or in which mixtures of lead are prepared as the principal or as a subsidiary business. They shall not apply to lead smelting works, even though processes named in paragraph (1) are carried on. Neither shall they apply to workplaces in which manufactured colours are intimately mixed or ground in oil or varnish in connection with another industry. (2) The workrooms in which the materials mentioned in paragraph 1 are prepared or packed shall be roomy, lofty, and so arranged that sufficient and constant exchange of air can take place. They shall be provided with a solid and smooth floor permitting of easy removal of dust by a moist method. The floor, unless for purposes of manufacture, shall be kept constantly wet, and shall be wet cleansed at least once daily. The walls, when not of a smooth washable surface or painted with oil, shall be whitewashed at least once a year. (3) The entrance of lead dust, or fumes, into the workrooms shall be prevented by suitable means as far as possible. Rooms which cannot be thus protected must be so separated from other rooms that neither dust nor fumes can enter them. (4) Lead melting pots shall be covered with a hood and shaft communicating directly or by a chimney with the open air. (8)[L] Grinding, sieving, and packing dry lead compounds, emptying litharge and minium furnaces, and other operations in which lead dust is generated, shall not be done except under an exhaust draught, or other efficient means for preventing the entrance of dust into the workrooms. In the packing of colours containing only a little lead, in small amounts, or in small packages for retail purposes, exception to these regulations can be allowed by the higher authorities. (9) Machines generating lead dust and not efficiently protected by their construction or method of use against the escape of dust, shall have all cracks occluded by means of thick layers of felt or similar material, so as to prevent the entrance of dust into the workrooms. Machines of this kind shall be provided with arrangements preventing pressure of the air inside. They shall not be opened until they are cool, and until the dust generated has settled. (10) Women shall not be employed in factories in which the colours specified in paragraph (1) are prepared except in work which does not expose them to the action of lead dust or fumes. Young persons shall not be employed nor be allowed on the premises in factories concerned exclusively or in great part with the preparation of lead colours or other lead compounds. (11) No person shall be employed in rooms where the processes specified in paragraph (1) are carried on who is not provided with a certificate from a qualified surgeon stating that he is physically fit and free from disease of the lungs, kidneys, and stomach, and that he is not addicted to alcohol. This certificate shall be kept and produced on demand to the Factory Inspector or Appointed Surgeon. (12) No person shall be employed in packing lead colours or mixtures containing lead or other lead compounds in a dry state, or with the coopering of the filled casks for more than eight hours daily. This regulation shall not apply where the packing machines are provided with effectual exhaust arrangements, or so constructed and used as effectually to prevent the escape of dust. No person under 18 years of age shall be employed in the process mentioned in the above paragraph, but exception can be allowed in the packing of colours containing lead in small amount, or in small packages for retail purposes, on application to the higher authorities. For the rest, no person coming into contact with lead or lead compounds shall be employed for more than 10 hours within the space of 24 hours. (13) The occupier shall provide overalls and head-coverings for all persons coming into contact with lead or lead compounds, and suitable footwear for those emptying the oxidising chambers. (14) The occupier shall not allow work involving exposure to dust to be performed except by workers provided with respirators or moist sponges covering the nose and mouth. (15) The occupier shall not allow work involving contact with soluble salts of lead to be done except by workers provided with waterproof gloves or by those whose hands have previously been smeared with vaseline. (16) The occupier shall provide the overalls, respirators, &c., mentioned in paragraphs (13) (14) and (15) for each one of the workers in sufficient number and in good condition. He shall take care that they are used only by the workers to whom they are severally assigned, and that in the intervals of work and during the time when they are not in use they shall be kept in their appointed place. Overalls shall be washed every week, and the respirators, sponges, and gloves before each time that they are used. (17) Lavatories and cloak rooms, and, separate from these, a mess room, shall be provided for the workers coming into contact with lead or lead compounds in a part of the works free from dust. These rooms shall be kept in a cleanly condition, free from dust, and shall be heated during the cold seasons. In the meal room or in some other suitable place there shall be means for warming food. The lavatories and cloak rooms shall be provided with water, vessels for rinsing the mouth, nail brushes for cleaning the hands and nails, soap, and towels. Arrangements shall also be made for keeping separate clothes worn during work from these taken off before the commencement of work. The occupier shall give facilities for all persons employed in emptying the oxidizing chambers to have a warm bath daily after the end of the work, and for those persons coming into contact with lead or lead compounds, twice weekly. The time for this shall be during the hours of work, and in the cold season the bath room, which must be on the factory premises, shall be heated. (18) The occupier shall appoint a duly qualified medical practitioner, whose name shall be sent to the Inspector of Factories and to the Health Authority. He shall examine the workers at least twice every month with a view to the detection of symptoms of lead poisoning. The occupier shall not employ workers suspected of symptoms of lead poisoning in occupations exposing them to lead or lead compounds until they have completely recovered. Those who appear peculiarly susceptible shall be suspended permanently from work. (19) The occupier shall keep a book, or make some official responsible for its keeping, recording any change in the personnel employed in lead or lead compounds and as to their state of health. He shall be responsible for the completeness and correctness of the entries except those made by the surgeon. The remaining regulations as to entries in the Health Register, &c., are similar to those already given in the Regulations for lead smelting works on p. 300. Use of Lead Colours (See also pp. 132-4) As explained on pp. 132-134 use of lead in the painting and varnishing trades frequently causes lead poisoning. This has led to regulations in various countries having for their object partly hygienic measures and partly also limitation of colours containing lead, such as prohibition of the use of lead paints in the interior of buildings or in the painting of public buildings and of ships, &c. The details of such regulations are seen in the German Imperial Regulations dated June 27, 1905: ORDER OF THE IMPERIAL CHANCELLOR RELATING TO THE PROCESSES OF PAINTING, DISTEMPERING, WHITEWASHING, PLASTERING, OR VARNISHING. JUNE 27, 1906 I.—_Regulations for carrying on the Industries of Painting, Distempering, Whitewashing, Plastering, or Varnishing._ _Regulation 1._—In the processes of crushing, blending, mixing, and otherwise preparing white lead, other lead colours, or mixtures thereof with other substances in a dry state, the workers shall not directly handle pigment containing lead, and shall be adequately protected against the dust arising therefrom. _Regulation 2._—The process of grinding white lead with oil or varnish shall not be done by hand, but entirely by mechanical means, and in vessels so constructed that even in the process of charging them with white lead no dust shall escape into places where work is carried on. This provision shall apply to other lead colours. Provided that such lead colours may be ground by hand by male workers over 18 years of age, if not more than one kilogram of red lead and 100 grains of other lead colours are ground by any one worker on one day. _Regulation 3._—The processes of rubbing-down and pumice-stoning dry coats of oil-colour or stopping not clearly free from lead shall not be done except after damping. All _débris_ produced by rubbing down and pumice-stoning shall be removed before it becomes dry. _Regulation 4._—The employer shall see that every worker who handles lead colours or mixtures thereof is provided with, and wears, during working hours, a painter’s overall or other complete suit of working clothes. _Regulation 5._—There shall be provided for all workers engaged in processes of painting, distempering, whitewashing, plastering, or varnishing, in which lead colours are used, washing utensils, nail brushes, soap and towels. If such processes are carried on in a new building or in a workshop, provision shall be made for the workers to wash in a place protected from frost, and to store their clothing in a clean place. _Regulation 6._—The employer shall inform workers, who handle lead colours or mixtures thereof, of the danger to health to which they are exposed, and shall hand them, at the commencement of employment, a copy of the accompanying leaflet (not printed with this edition), if they are not already provided with it, and also a copy of these Regulations. II.—_Regulations for the Processes of Painting, Distempering, Whitewashing, Plastering, or Varnishing when carried on in connection with another Industry._ _Regulation 7._—The provisions of paragraph 6 shall apply to the employment of workers connected with another industry who are constantly or principally employed in the processes of painting, distempering, whitewashing, plastering, or varnishing, and who use, otherwise than occasionally, lead colours or mixtures thereof. The provisions of paragraphs 8-11 shall also apply if such employment is carried on in a factory or shipbuilding yard. _Regulation 8._—Special accommodation for washing and for dressing shall be provided for the workers, which accommodation shall be kept clean, heated in cold weather, and furnished with conveniences for the storage of clothing. _Regulation 9._—The employer shall issue regulations which shall be binding on the workers, and shall contain the following provisions for such workers as handle lead colour and mixtures thereof: 1. Workers shall not consume spirits in any place where work is carried on. 2. Workers shall not partake of food or drink, or leave the place of employment until they have put off their working clothes and carefully washed their hands. 3. Workers, when engaged in processes specified by the employer, shall wear working clothes. 4. Smoking cigars and cigarettes is prohibited during work. Furthermore, it shall be set forth in the regulations that workers who, in spite of reiterated warning, contravene the foregoing provisions may be dismissed before the expiration of their contract without notice. If a code of regulations has been issued for the industry (par. 134a of the G.O.) the above indicated provisions shall be incorporated in the said code. _Regulation 10._—The employer shall entrust the supervision of the workers’ health to a duly qualified medical man approved of by the public authority, and notified to the factory inspector (par. 139b of the G.O.), and the said medical man shall examine the workers once at least in every six months for symptoms indicative of plumbism. The employer shall not permit any worker who is suffering from plumbism or who, in the opinion of the doctor, is suspected of plumbism, to be employed in any work in which he has to handle lead colours or mixtures thereof, until he has completely recovered. _Regulation 11._—The employer shall keep or shall cause to be kept a register in which shall be recorded the state of health of the workers, and also the constitution of and changes in the staff; and he shall be responsible for the entries being complete and accurate, except in so far as they are affected by the medical man. Then follow the regulations as to entries in the Register, as to which see the Regulations as to lead smelting works, p. 300. Type Founding and Compositors’ Work (See also pp. 138 and 139) Fumes which may carry up lead dust are generated in the casting of letters. Dust arises also in setting the type. General hygienic measures are especially called for such as healthy conditions in the workrooms. Much can be done by exhaust ventilation locally applied to the type cases and to letter (mono- and linotype) casting machines. Vacuum cleaning of printing workshops and type cases is strongly advised. As some lead poisoning in printing works is attributable to lead colours or bronze powder containing lead their use should be limited as much as possible. The German Imperial Regulations for printing works and type foundries are as follows: ORDER OF THE FEDERAL COUNCIL OF JULY 31ST, 1897, REGULATING LETTERPRESS PRINTING WORKS AND TYPE FOUNDRIES, IN PURSUANCE OF SECTION 120_E_ OF THE INDUSTRIAL CODE I. In rooms in which persons are employed in setting up type or manufacture of type or stereotype plates the following provisions apply: 1. The floor of workrooms shall not be more than a half a meter (1·64 feet) below the ground. Exceptions may only be granted by the higher administrative authority where hygienic conditions are secured by a dry area, and ample means of lighting and ventilating the rooms. Attics may only be used as workrooms if the roof is provided with a lathe and plaster ceiling. 2. In workrooms in which the manufacture of type or stereotype plates is carried on, the number of persons shall not exceed such as would allow at least fifteen cubic meters of air space (529·5 cubic feet) to each. In the rooms in which persons are employed only in other processes, there shall be at least twelve cubic meters of air space (423·5 cubic feet) to each person. In cases of exceptional temporary pressure the higher administrative authority may, on the application of the employer, permit a larger number in the workrooms, for at the most 30 days in the year, but not more than will allow ten cubic meters of air space (353 cubic feet) for each person. 3. The rooms shall be at least 2·60 meters (8· feet) in height where a minimum of fifteen cubic meters are allowed for each person, in other cases at least 3 meters (9·84 feet) in height. The rooms shall be provided with windows which are sufficient in number and size to let in ample light for every part of the work. The windows shall be so constructed that they will open and admit of complete renewal of air in workrooms. Workrooms with sloping roof shall have an average height equal to the measurements given in the first paragraph of this section. 4. The rooms shall be laid with close fitting impervious floor, which can be cleared of dust by moist methods. Wooden floors shall be smoothly planed, and boards fitted to prevent penetration of moisture. All walls and ceilings shall, if they are not of a smooth washable surface or painted in oil, be limewashed once at least a year. If the walls and ceilings are of a smooth washable surface or painted in oil, they shall be washed at least once a year, and the oil paint must, if varnished, be renewed once in ten years, and if not varnished once in five years. The compositors’ shelves and stands for type boxes shall be either closely ranged round the room on the floor, so that no dust can collect underneath, or be fitted with legs, so that the floor can be easily cleaned of dust underneath. 5. The workrooms shall be cleared and thoroughly aired once at least a day, and during the working hours means shall be taken to secure constant ventilation. 6. The melting vessel for type or stereotype metal shall be covered with a hood connected to an exhaust ventilator or chimney with sufficient draught to draw the fumes to the outer air. Type founding and melting may only be carried on in rooms separate from other processes. 7. The rooms and fittings, particularly the walls, cornices, and stands for type, shall be thoroughly cleansed twice a year at least. The floors shall be washed or rubbed over with a damp cloth, so as to remove dust once a day at least. 8. The type boxes shall be cleansed before they are put in use, and again as often as necessary, but not less than twice at least in the year. The boxes may only be dusted out with a bellows in the open air, and this work may not be done by young persons. 9. In every workroom spittoons filled with water and one at least for every five persons shall be provided. Workers are forbidden to spit upon the floor. 10. Sufficient washing appliances, with soap and at least one towel a week for each worker, shall be provided as near as possible to the work for compositors, cutters, and polishers. One wash-hand basin shall be provided for every five workers, fitted with an ample supply of water. The employer shall make strict provision for the use of the washing appliances by workers before every meal and before leaving the works. 11. Clothes put off during working hours shall either be kept outside the workroom or hung up in cupboards with closely fitting doors or curtains, which are so shut or drawn as to prevent penetration of dust. 12. Artificial means of lighting which tend to raise the temperature of the rooms shall be so arranged or such counteracting measures taken that the heat of the workrooms shall not be unduly raised. 13. The employer shall draw up rules binding on the workers which will ensure the full observance of the provisions in sections 8, 9, 10, and 11. II. A notice shall be affixed and a copy sent to the local police authority shewing: (_a_) The length, height, and breadth of the rooms. (_b_) The air space in cubic measure. (_c_) The number of workers permitted in each room. A copy of Rules 1 to 13 must be affixed where it can be easily read by all persons affected. III. Provides for the method of permitting the exceptions named above in sections 2 and 3, and makes it a condition of reduction in cubic air space for each person employed as type founder or compositor that there shall be adequate mechanical ventilation for regulating temperature and carrying off products of combustion from workrooms. Ceramic Industry (See also pp. 135-8.) A complete substitute for lead in glazes seems as yet impossible on technical grounds, as glaze containing lead has qualities which cannot be obtained without its use. In small works the technique necessary for the production of leadless glazes (special kinds of stoves) cannot be expected, especially as those carrying on a small industry lack the necessary knowledge of how to be able to dispense with the use of lead glazes and substitute leadless materials without complete alteration in their methods of manufacture. And yet discontinuance or the utmost possible limitation of the use of lead glazes and colours is most urgently needed in all small ceramic workshops, as they are not in a position to put in localised exhaust ventilation, &c., which is possible in large factories. Observance of even the simplest hygienic measures can scarcely be obtained. Consequently very severe cases of lead poisoning are met with in small works. An effort in the direction of discontinuance of lead glazes was made in Bohemia, where (at the cost of the State) technical instruction was given by an expert on the preparation of leadless glazes especially in districts where the industry was carried on in the homes of the workers. This procedure, extension of which is expected, had good results. Many have demanded, in view of the possibility of substituting leadless for lead glazes, the total prohibition of lead. Such is the view of the Dutch inspector De Vooys; Teleky and Chyzer share the view expressed so far as the small industry is concerned, since the practicability of the change has been demonstrated. English authorities (Thorpe, Oliver) propose diminution of the lead in the glaze in such a way that on shaking with weak acid not more than a specified small quantity shall be dissolved (Thorpe test). In my opinion such a measure is hardly enough for the small industry. I do not expect much good from obligatory use of fritted glazes. In addition to earthenware, manufacture of tiles and bricks leads not infrequently to cases of lead poisoning from use of lead glaze. The following measures apply to the larger ceramic works. Since risk is considerable, not only in glost placing but also in grinding, ware-cleaning, &c., closed ball mills in grinding and locally applied exhaust ventilation in ware-cleaning operations, &c., must be arranged. Personal cleanliness and proper equipment of a factory in all the essentials insisted on on pp. 226-9 are important, but nothing can take the place of efficient locally applied ventilation. Vitreous enamelling of household utensils, baths, gas stoves, signs, &c., is an analogous process as enamels containing lead may be used. Sieving on the dry powder and brushing off superfluous glaze often cause poisoning. Here generally the same preventive measures apply. [In Great Britain the china and earthenware industry is placed under Regulations dated January 2, 1913, which supersede the previous Special Rules. These Regulations—thirty-six in number—provide, among other usual provisions, (1) for efficient exhaust ventilation in (_a_) processes giving rise to injurious mineral dust (fettling and pressing of tiles, bedding, and flinting, brushing and scouring of biscuit) and (_b_) dusty lead processes (ware cleaning, aerographing, colour dusting, litho-transfer making, &c.); and (2) monthly periodical medical examination of workers in scheduled lead processes.] In the Netherlands, in consequence of lead poisoning in porcelain works, committees were appointed to inquire into the subject in 1901, 1902, and 1903. File Cutting (See also p. 140) In file cutting the file is cut on a lead bed or a bed of an alloy of zinc and lead. The same source of poisoning occurs in other industries such as amber working. Lead poisoning among file cutters is pronounced. The best preventive measure is substitution of a bed of pure zinc for lead. The German Imperial Health Office have issued a ‘Warning notice’ for file-cutters. LEAFLET FOR FILE-CUTTERS The use of lead beds or of alloys of lead with other metals has repeatedly brought about lead poisoning in file-cutters. The beds also supposed to be made of zinc usually contain a considerable proportion of lead, and are thus dangerous to health. Among file-cutters lead poisoning arises from absorption of the metal in small quantities by means of dirty hands, eating, drinking, smoking or chewing of tobacco. The consequences of this absorption are not at once noticeable. They appear only after weeks, months, or even years, according to the extent to which the lead has accumulated in the system. _How does lead poisoning show itself?_—The first sign is usually a bluish-grey line on the gums called the blue line, associated with anæmia or pallor. Later symptoms are very varied. Most frequently lead colic comes on, the affected person suffering from violent cramplike pains starting from the navel; the stomach is hard and contracted; very often vomiting and constipation ensue, or, very occasionally, diarrhœa. In some cases paralysis shows itself—generally in those muscles which extend the fingers, usually affecting both arms. In exceptional cases other muscles of the arms and legs are affected. Sometimes lead poisoning manifests itself in violent pains in the joints—generally the knee, more rarely in the shoulder and elbow. In specially severe cases brain trouble supervenes—violent headache, convulsions, unconsciousness or blindness. Finally lead poisoning may set up disease of the kidneys—Bright’s disease and gout. Women suffering from lead poisoning frequently miscarry. Children born alive may, in consequence of lead poisoning, die in their first year. Children fed at the breast are poisoned through the milk. Apart from severe cases complicated with brain trouble, which are often fatal, persons suffering from lead poisoning generally recover if they withdraw from further contact. Recovery takes place after a few weeks, but in severe cases only after months. The most effective preventive measures are cleanliness and temperance. Persons who, without being drunkards, are accustomed to take spirits in quantity are more likely to succumb than the abstemious. Spirits should not be taken during working hours. In regard to cleanliness, file-cutters using lead beds should be especially careful and observe the following rules: 1. Since soiling the hands with lead cannot be entirely avoided, smoking and chewing tobacco during work should be given up. 2. Workers should only take food and drink or leave the works after thoroughly washing the hands with soap—if possible with pumice stone; if drinking during work cannot be wholly given up the edges of the drinking vessels ought not to be touched by the hands. If a file-cutter falls ill in spite of precautions with symptoms pointing to lead poisoning he should, in his own and his family’s interest, at once consult a doctor, telling him that he has been working with a lead bed. Other Industries in which Lead is used In cutting _precious stones_ with use of lead discs lead poisoning frequently occurs, especially where this trade, as in some parts of Bohemia, is carried on as a home industry. The authorities have required substitution of carborundum (silicon carbide) for lead discs. As, therefore, an efficient substitute is possible, use of lead should be prohibited. Similarly, use of lead in the making of musical instruments should, if possible, be discontinued. Brass pipes in _musical instrument_ making are filled with lead to facilitate hammering and bending, and in this way poisoning has occurred. In numerous other industries where the use of lead cannot be avoided, and where consequently the danger must be present, as, for instance, in _lead melting_, _soldering_, _lead rolling_, _stamping_, _pressing_, &c., in the manufacture of _lead piping_, _shot_, _wire_, _bottle capsules_, _foil_, _toys_, and many other articles, general preventive measures should be carefully carried out. _Melting of lead_ and _lead alloys_ should be carried out only under efficient exhaust ventilation. In larger works where dust is generated this should be drawn away at the point where it is produced. This applies also to processes in the chemical industries where lead or lead compounds are used, seeing that no substitute is possible. Zinc, Brass-casting, Metal Pickling, Galvanising (See also pp. 151 and 182) In zinc smelting account has to be taken of fumes which may contain lead, zinc, arsenic, sulphur dioxide, and carbonic oxide. Metallic fumes require to be condensed—a procedure in harmony with economic interests. This is effected in a technically arranged condensing system, consisting of a condenser and prolong, in which the fumes are given as large a space as possible in which to condense and cool. In order to prevent the entry of fumes into the shed when removing distillation residues, hoods should be arranged over the front of the furnace through which the gases can be conducted into the main chimney stack or be drawn away by a fan; in addition the residue should fall into trolleys which must either be covered at once or placed under a closely fitting hood until the fuming contents are cool. As the mixing of the materials for charging and the sifting and packing of the zinc dust (poussière) may cause risk, these processes require to be carried out mechanically with application of local exhaust. Such an arrangement is shown in fig. 59 below. The material which is fed in is carried by the elevator to the sifting machine, falls into the collecting bin, and is then packed. The points at which dust can come off are connected with the exhaust and carried to the dust collector; fans carry the filtered air to the outside atmosphere. [Illustration: FIG. 59.—Arrangement for Sieving and Packing Zinc Dust (poussière). _a_ Charging hopper; _b_ Distributor; _c_ Elevator; _d_ Sieve; _e_ Collector; _f_ Packing machine; _g_ Exhaust pipe; _h_ Worm; _i_ Dust Collector; _k_ Motor] Only paragraphs 3-8 of the German Imperial Regulations dated February 6, 1900, for Spelter Works are quoted, as the remainder are on precisely similar lines to those for lead smelting works given in full on p. 300. 3. Crushing zinc ore shall not be done except in an apparatus so arranged as to prevent penetration of dust into the workroom. 4. The roasting furnaces as well as the calcining furnaces shall be provided with effective exhaust arrangements for the escaping gases. The occupier shall be responsible for their efficiency during the time the furnace is at work. 5. To avoid dust, ores intended for charging distillation furnaces shall not be stacked in front of or charged into the furnace, or mixed with other material, except in a damp condition. This regulation shall not apply to large so-called Silesian Retorts when in use in the zinc smelter; yet in the case of them also the Higher Authorities may require damping of the charging material if specially injurious to health. 6. Dust, gases and vapours escaping from distillation furnaces shall be caught as near as possible to the point of origin by efficient arrangements and carried out of the smelting rooms. The entrance of the gases from the fires into the smelting room shall be prevented as far as possible by suitable arrangements for drawing them off. 7. Residues shall not be drawn into the smelting room; they shall be caught in closed channels under the furnaces and emptied from these channels at once into waggons placed in passages beneath the distillation rooms. This regulation (where the Higher Authorities approve) shall not apply to existing plants, should it be impossible to make the arrangements mentioned in Reg. 1, or where such additions could only be added by rebuilding at a prohibitive cost. 8. Sieving and packing of by-products obtained by the distillation of zinc (poussière, flue dust) shall not be done except in a special room separate from other workrooms, in accordance with Reg. 1. Sieving shall only be done in an apparatus so arranged as to prevent escape of dust. In _brass casting_, in order to prevent occurrence of brass-founders’ ague, it is necessary that the zinc oxide fumes evolved should be effectively drawn away from the crucible by locally applied exhaust ventilation. General ventilation merely of the room is almost useless, as in casting the fumes rise up into the face of the pourer. Seeing that casting is carried on in different parts of the foundry, it is advisable to connect up the hoods over the moulds by means of metal piping with the exhaust system, or to arrange a flexible duct which can be moved about as occasion requires. Dangerous acid fumes (notably nitrous fumes) are evolved in metal pickling, especially of brass articles (such as harness furniture, lamp fittings, church utensils, &c.), for the purpose of giving them a shiny or dull surface by immersion in baths of nitric, hydrochloric, or sulphuric acid. As severe and even fatal poisoning has occurred in these operations they should be conducted in isolated compartments or channels under exhaust ventilation. If the ventilation provided is mechanical an acid proof earthenware fan or an injector is necessary. The following description applies to one large works: The pickling troughs are placed in a wooden compartment closed in except for a small opening in front. To this compartment a stoneware pipe leading to a stoneware fan is connected. The nitrous fumes are drawn through the pipe and led into the lower part of an absorption tower filled with cone-shaped packing material through which water trickles from a vessel placed at the top. The greater part of the acid fumes are absorbed as they pass upwards and the water collects in a receiver below, from which it is blown by compressed air into the vessel above for utilisation again until it becomes so charged with acid that it can be used for pickling purposes. In _galvanising_ and _tinning_ acid fumes, injurious acroleic vapour, and metallic fumes can arise as the metal articles (iron, copper, &c.) first require to be cleaned in an acid bath and then dipped into molten fat or molten zinc or tin. Here also the fumes should be drawn away in the manner described. Recovery and Use of Mercury Escape of mercury vapour and development of sulphur dioxide seriously endanger workers engaged in smelting cinnabar. The danger can be minimised by proper construction of furnaces preventing escape as far as possible of fumes and most careful condensation of the mercury in impervious and sufficiently capacious chambers and flues. Continuous furnaces are to be preferred to those working intermittently. The system of condensing chambers and flues must offer as long a passage as possible to the fumes, and care must be taken to keep them thoroughly cool. Removal of the deposit rich in mercury from the flues is especially fraught with danger. This work should only be carried on after efficient watering by workers equipped with respirators, working suits, &c. _Use of mercury._—Mirror making by coating the glass with mercury used to be one of the most dangerous occupations. Now that a fully adequate substitute for mercury has been found in the nitrate of silver and ammonia process, use of mercury should be prohibited. As a home industry especially mirror coating with mercury should be suppressed. Fortunately the dangerous mode of production is rapidly being ousted. The following requirements are contained in a decree of the Prussian Government dated May 18, 1889: (1) Medical certificate on admission to employment in mirror making with use of mercury; (2) restriction of hours to six in summer and in winter to eight daily, with a two hours’ mid-day interval; (3) fortnightly examination of the workers; (4) air space per person of 40 cubic meters in the coating room and 30 in the drying room, and, in both, introduction of 60 cubic meters of air per head per hour; (5) Work to cease if the temperature of the room in summer reaches 25° C. Measures are necessary to prevent occurrence of mercury poisoning in hatters’ furriers’ processes (preparation of rabbit fur for felt hats) in consequence of the use of nitrate of mercury. Danger arises chiefly in cutting the hair, in dressing and drying, in sorting, and also in the subsequent stages of hard felt hat manufacture. Aspiration of the dust and fluff at its point of generation, isolation of the drying rooms and prohibition of entry into them while drying is going on, are necessary. In dressing (commonly known as ‘carotting’), the nitric acid vapour requires to be drawn away. In addition strict personal hygiene, especially of the teeth, is very important. Processes involving _water gilding_ (nowadays practised on a very small scale) should only be carried on in stoves provided with exhaust ventilation. Electroplating, fortunately, has almost entirely taken its place. As cases of mercury poisoning have been reported from use of mercurial pumps in producing the vacuum inside _electric incandescent bulbs_, air pumps should be substituted for them whenever possible. _Barometer_ and _thermometer_ makers may and do suffer severely if care is not taken to draw away the fumes and ensure good ventilation of the workrooms. Careless handling and the dropping of mercury on the benches make it difficult to prevent some volatilisation. Personal hygiene and especially a proper hygiene of the mouth are of the greatest importance in this class of work. Preparation of mercury compounds in chemical factories, especially the dry processes (sublimation), as in production of cinnabar, corrosive sublimate and calomel mixing, grinding, and sublimation, require to be carried on in closed apparatus. Preparation of the substances named above in solution involves much less risk than subliming. From our point of view, therefore, the former is to preferred. Arsenic, Arsenic Compounds, Arseniuretted Hydrogen For arsenic works imperviousness of the system and as complete condensation as possible are necessary to prevent escape of fumes. Respirators should be worn in manipulations with white arsenic, and such work as packing done under conditions of locally applied exhaust ventilation. Industrial use of arsenic compounds, in view of the risk attaching to them, should be reduced as much as possible. This has sometimes been achieved by technical improvement in processes of manufacture. Thus in the colour industry, where formerly colours containing arsenic played an important rôle, coal-tar colours have taken their place, and use of arsenic even in these (as in the manufacture of fuchsin) has been replaced by nitrobenzene. As the danger from arseniuretted hydrogen gas is especially great in processes in which acid acts on metal and either one or both of them contain arsenic, the materials, should be as free from arsenic as possible, in the production, for example, of hydrogen for soldering, in extracting metals by means of acids, in galvanic elements, in accumulator works, in the storage and transport of acids in metal vessels, and in galvanising. In any case the workers in these industries should be warned of the danger and instructed in case of emergencies. For soldering exclusive use of hydrogen produced electrolytically and procurable in steel cylinders is advisable. Extraction and Use of Gold and Silver In the extraction of gold and silver by amalgamation and subsequent volatilisation of mercury there is risk of mercurial poisoning. The preventive measures necessary are similar to those for poisoning in the recovery of mercury (see p. 327). _Argyria_ in pearl bead blowers can be avoided by using pumps to blow the silver solution into the beads instead of the mouth. In electroplating the possibility of poisonous fumes arising from the baths must be guarded against because hydrocyanic (prussic) acid, though only in minute quantities, may be evolved; care must be taken that the workrooms are well ventilated or the baths hooded. Careful personal hygiene is essential, for the prevention of skin diseases from which workers in electroplating often suffer. VII _PREVENTIVE MEASURES IN OTHER TRADES_ Ceramic Industry In the glass industry use of lead, chrome, and arsenic compounds should be restricted as much as possible or allowed only under suitable precautions (exhaust ventilation, personal hygiene, &c.). _Etching on glass_ by means of hydrofluoric causes almost inevitably injury to the workers. Rendering the surface of glass opaque should preferably be done by sand blast. When a bath of hydrofluoric acid for etching on glass is used the fumes require to be drawn away by hoods over the baths and the work-rooms well ventilated. Further precautionary measures are called for in view of industrial poisoning by furnace gases in various ceramic industries, as, for example, cement works, glass works, and tile works. The following suggestions are made in the technical introduction to the Germany Factory Act for prevention of poisoning from carbonic oxide, carbon dioxide, and sulphur dioxide: (1) Even the fixing of benches which might be used for sleeping on near the furnaces should be strictly forbidden; (2) All furnaces which are roofed over should be provided with adequate side and roof ventilation; (3) All gas pipes and cocks must be maintained in an impervious condition. Manufacture and Use of Varnishes and Drying Oils Unpleasant fumes are given off on boiling linseed oil with oxidising substances, which should be prevented by closely fitting covers and condensation of the fumes in cooling apparatus. In heating and dissolving resin for the production of varnishes the fumes evolved require to be dealt with in a similar way. Preventive measures must be taken also in the use of quick-drying paints on ships and inside steam boilers as, owing to the rapid evaporation of the poisonous solvents—benzene, benzine and turpentine—fatalities have occurred. As a result of elaborate investigation by the inspectors of factories in Hamburg the following instructions were issued: Quick-drying paint for ships and for preventing rust should only be used under the supervision of a person conversant with the danger to health and risk from fire. They should only be allowed for the painting of interior surfaces after adoption of adequate precautions—free ventilation, use of smoke helmets with air conducting apparatus, and no naked lights, &c. Since use of quick-drying paints cannot easily be prohibited and the fumes from the substitutes for turpentine—benzene and other light tarry oils—exert injurious effect on man, precautionary measures are called for. Regulation of working hours is as important as provision of adequate ventilation. Workers, therefore, should be allowed proper intervals from work. Confined spaces in the interior of ships should be adequately ventilated before, after, and during work; all persons who use the paints should have opportunity for washing given them at their work places, and should be compelled to avail themselves of these facilities; indulgence in alcohol and smoking should be prohibited; receptacles in which quick-drying paints are sold should be provided with an air-tight cover and with a warning notice as to the danger of the contents. Paints made from petroleum fractions of low boiling-point, light coal-tar oils, turpentine oil, carbon bisulphide, and similar substances, are to be regarded as injurious to health. Persons under eighteen, and women, should not be allowed to work with quick-drying paints. Obligatory notification of cases of poisoning by hydrocarbons and other similar poisonings would have a good effect. Schaefer (Inspector of Factories in Hamburg) has drawn up the following leaflet for painters, varnishers, workers in dry docks, and others engaged in painting with quick drying paints and oils: All quick-drying paints and oils are more or less injurious to health and very inflammable, as they contain volatile substances such as benzine (naphtha, petrol ether), benzene, turpentine oil, carbon bisulphide, &c. These paints are mostly used in painting interiors of ships, boilers, machinery, apparatus, &c., and come on the market under various names, such as Black Varnish Oil, Solution, Patent Colour, Anti-corrosive, Dermatin, Acid-proof Paint, Apexior, Saxol, &c. Even at ordinary temperatures the volatile fluids used as mediums for dry paint powders, or as a first coating, evaporate. Air filled with the fumes is not only harmful to health, but liable to explosion. Working with these paints and oils in the interior of ships, or steam boilers and the like, has repeatedly led to explosions and fatal poisoning. _Danger of Poisoning._—All persons are exposed to the danger of poisoning who use quick-drying paints in the interior of rooms or receptacles, or otherwise manipulate the paints. The warmer the room and the less ventilation there is before and during the painting, the greater the danger of poisoning. On the other hand, use of these paints in the open air is generally without effect. Poisoning arises from inhaling the fumes of hydrocarbons. The symptoms are oppression, headache, inclination to vomit, cough, hiccough, giddiness, noises in the ears, drunken-like excitement, trembling and twitching. Inhalation of larger quantities brings on, quite suddenly and without previous warning, unconsciousness, which may last many hours and is often fatal. Except in severe cases the symptoms generally soon disappear, if the affected person withdraws from further contact with the fumes. The most effective protection therefore against poisoning is fresh air and temperance. In so far as painting with quick-drying materials is necessary in workrooms, interiors of ships, water and ballast tanks, double bottoms, bunkers, bilges, cabins, boilers and receptacles, care must be taken to ensure thorough ventilation before, after, and while the work is going on. Where no sufficient ventilation is possible these paints ought not to be used. Frequent intermission of work by a short stay in the open air is useful. When working in spaces not easily accessible, the worker should be roped. Speaking, singing, or whistling during work favours inhalation of the fumes and is, therefore, to be avoided. Indulgence in spirits, especially during working hours, increases the danger of poisoning. Habitual drinkers should not be allowed to work at all with quick-drying paints and oils. At the first signs of discomfort work should be stopped. An immediate stay in the open air will then usually dispel the poisonous symptoms. If, notwithstanding this, severe symptoms develop, oxygen inhalation should be commenced forthwith and medical aid called in. Production of Vegetable Foods and Luxuries (See also p. 154) Measures for the prevention of industrial poisoning have to be thought of in connection with drying processes (by smoke gases, carbon dioxide, and carbonic oxide), many processes of preserving (use of sulphur dioxide, &c.), and fermentation (accumulation of carbonic acid). In breweries the use of kilns allowing fire gases to enter the drying-rooms formerly caused carbonic oxide and carbonic acid poisoning. The general introduction of hot air kilns provided with mechanical malt-turning apparatus should be insisted on, and is in keeping with progress in technical methods. The accumulation of carbonic acid in the malting cellars can be prevented in the same way as in a distillery. If ammonia is used for _refrigeration_, precautions are necessary so that, in the event of leakage or bursting of pipes, the workers may escape. Naturally the imperviousness of the freezing system must be guaranteed. Oppression and danger to the health of the workers is occasionally caused by the development of gases in the coating of barrels with pitch, partly preventable by the use of pitching machines. In the production of _spirits_ carbonic acid poisoning can occur from accumulation of carbonic acid in the fermentation cellars. These should be thoroughly ventilated and in view of the heaviness of the gas, openings for ventilation should always be located at the floor level. In the _sulphuring of malt_ the following recommendations were made by the Austrian inspectors: During the sulphuring process the room ought not to be entered (for the turning over of the malt). When the sulphur has been burnt, the drying-room must be ventilated from the outside, by opening the windows and letting in cold currents of air, until the sulphur dioxide has completely dispersed, which can be tested by holding a strip of moistened blue litmus paper at the half-opened door. If it does not turn red, turning over of the malt may be proceeded with. As the _sulphuring of hops_ in hop districts is done in primitive little kilns, in which the hops are spread out on a kind of gridiron and sulphur burnt below in iron pans, development of sulphur dioxide may affect the workers. The following regulations are therefore suggested for work in these kilns: The rooms in which sulphuring takes place must be airtight, capable of being locked, and provided with arrangements which make it possible to remove the sulphur dioxide fumes before the room is entered. This can usually be done by a strong coke fire, maintained in the chimney place, which creates the necessary draught. If fans are used, it must be remembered that iron is affected and destroyed by acid gases; stoneware fans are therefore advisable. In the production of _vinegar_, air escapes laden with acetic acid vapour, alcohol, lower oxidation products of alcohol, aldehyde, acetic ether, &c. Their escape can be avoided if the whole process is carried on in a closed self-acting apparatus with the advantage also that no loss occurs. In premises for _drying agricultural products_ (fruit, chicory, turnips) the persons employed in the drying-room are exposed to the danger of carbonic oxide poisoning from direct firing. The following recommendations for work in drying-rooms with direct firing are taken from an Austrian decree of 1901: The lower drying chambers, in which the real drying process is effected, should be so arranged that the objects dried in them can be removed by means of long-handled implements through a passage shut off from the drying-room. The separation of this passage can be effected by loose tin plates which can be removed as required for the work of turning or removal of the dried products, so that the worker need not come into contact with the gases. Open fires should be so arranged that if required they can be shut off, by simple arrangements, from the drying-rooms in which the workers are temporarily occupied in carrying in, and turning, the objects to be dried, transferring the partly dried products to hotter hurdles, and emptying them when finished, in such a way that the entrance of combustion gases into the drying chambers can be completely prevented. In order, however, to prevent a back draught, arrangements must be made for simultaneous removal of the gases by pipes connected with a chimney or smoke flue. The places from which the fires are charged should, in addition, be furnished with suitably arranged openings for ventilation leading into the outer air, in order to neutralise, in case of need, any back draught from the furnaces into the rooms. The windows of the drying chambers should be so arranged as to open both from within and without. The floor of the roof space, or attic, which forms at the same time the ceiling of the upper drying-room, should be kept perfectly airtight, as also the openings into it through which the steam pipes pass. For this purpose the floor should be a double one and the openings or boxes into which material is thrown should have a double cover above and below. Further, situated in the highest point of the ceiling of the roof space, there should be a suitable number of openings topped by louvred turrets. In the roof space no work should be done except manipulations necessary for the charging of the hurdles with the goods to be dried. Use of the roof floor as a sleeping or living room is not permissible. Before the workers enter the drying chambers for the purpose of turning the materials, the stove should be shut off, the gases drawn from the furnace into the chimney or flue, and at the same time the doors and windows of the drying rooms opened. Entering of drying chambers for working purposes should only be done after a sufficient time has elapsed for removal of the air by ventilation. Charging of the furnaces should be so arranged that they burn as low as possible before the removal of the dried materials and before subsequent work in the drying chambers. Seeing that chicory and turnip drying is done intermittently by night, a special sleeping or waiting room with free ventilation should be provided. The regulations concerning the ventilation of the workrooms are to be made known to the workers. Cigar Industry In order to prevent injury to health to tobacco workers the dust and fumes, especially at cutting and sifting machines, require to be drawn away by locally applied exhaust ventilation. The workrooms, moreover, must conform to hygienic requirements, especially as to cleanliness. Washing accommodation and baths are desirable, but are only likely to be provided in large works. Wood Working (See also p. 154) Risk from poisonous woods can be avoided by exhaust ventilation applied to the wood-working machinery. To lessen the danger to health in the use of methylated spirits in the polishing of wood adequate ventilation of the workrooms is necessary; drawing off the fumes by local ventilation is often impossible. Production of Wood-pulp (Cellulose) and Paper. In the _sulphite cellulose_ process, sulphur dioxide may escape from the sulphur stoves or from the boilers; escape of sulphur dioxide is also possible through defective gas pipes and condensers. Gas pipes and condensers require to be quite impervious and condensation or absorption as complete as possible. The fumes escaping from the boilers should be led through pipes into closed boilers for condensation purposes; the gases not condensed here are to be led into absorption towers. In the manufacture of _paper_ with use of chloride of lime for bleaching chlorine can be given off in considerable quantity, requiring removal of the gases from the apparatus. The use of poisonous colours containing lead or arsenic, and addition of lead-containing substances to the paper pulp, is now very rare. Textile Industries. (See also p. 156) In the textile industry only a few manipulations are associated with serious risk of poisoning. Those engaged in carbonising are exposed to acid fumes; closed and ventilated apparatus, therefore, as far as possible, require to be used and the acid gases escaping from them should be absorbed. These requirements are fulfilled by carbonising stoves which are ventilated and connected with coke condensers. It is especially urged that only arsenic free acid be employed, as otherwise danger of poisoning by arseniuretted hydrogen may be incurred. In the making of _artificial silk_, according to the Chardonnet-Cadoret process, the precautionary measures recommended in nitrating together with careful exhaustion of the ether and camphor fumes apply. The combustion gases (containing carbonic oxide) developed in the process of singeing are harmful and require to be led away at their source. Poisonous metallic salts, especially lead and lead-containing zinc, are used as weighting materials, in dressing or finishing, and sometimes cause symptoms among the workers. Apart from the danger to those occupied in spinning and weaving, the workers who handle these products (in the clothing trade) also run a risk from lead. Precautionary measures are necessary in the _varnishing of woven materials_, as the substances employed may contain volatile poisonous solvents. If these poisonous solvents cannot be replaced by others less poisonous, carefully applied exhaust ventilation must be provided. The same holds good when carbon bisulphide, benzene, and benzine are used as solvents in the production of woven materials impregnated with indiarubber. Employment of lead salts and other poisonous metallic salts in the glossing of woven materials, or in order to render them non-inflammable, is to be deprecated. Cases of lead poisoning have occurred in the working-up of asbestos, as lead wire is sometimes used in the process of weaving. To protect workers in _chlorine_ and _sulphur bleaching_ from poisoning by chlorine or sulphur dioxide the gases arising from the bleaching liquids should be drawn away. Use of closed bleaching apparatus, as is the case in large works, reduces the danger to a minimum. Bleaching-rooms should be connected with a powerful stoneware fan, so that they may be thoroughly aired before they are entered. Dye Works Industrial poisoning by dyes is, in general, rare, as the natural dyes (wood and tar dyes) are almost without exception non-poisonous. Further, the dyes are generally only used in diluted solution. Formerly the arsenic in many tar dyes caused poisoning, but now it is usually the mordants which have harmful effect. To this class belong chromic acid salts and mordants containing arsenic, antimony (tartar-emetic), and also chloride of tin. In the scraping off of layers of paint containing arsenic, arsenic dust may arise. In Turkey red dyeworks, especially sodium arsenite is used for fixing the tar dyes. Orpiment dyes which may give off poisonous arseniuretted hydrogen gas are becoming less and less used; from the point of view of industrial hygiene, the utmost possible avoidance of the use of arsenic-containing preparations in dye works is to be recommended. Where this is not possible, strict personal hygiene must be enforced (as, for instance, application of vaseline to the skin). FOOTNOTES [A] Leymann has dealt with the conditions of health in a large aniline factory in a later work which is referred to in detail in the section on the aniline industry. [B] Poisoning by lead, phosphorus, and arsenic contracted in a factory or Workshop has been notifiable in Great Britain and Ireland since 1895. [C] ‘On the Nature, Uses, and Manufacture of Ferro-silicon,’ 1909, Cd. 4958. [D] In Great Britain section 73 of the Factory and Workshop Act, 1901, requires every medical practitioner attending on or called in to visit a patient whom he believes to be suffering from lead, phosphorus, arsenical or mercurial poisoning, or anthrax, contracted in any factory or workshop, to notify the Chief Inspector of Factories, and a similar obligation is placed on the occupier to send written notice of every case to the inspector and certifying surgeon of the district. The table on p. 222 shows the number of reports included in returns for the years 1900-12. Cases of acute poisoning in factories and workshops are reportable to the Inspector and certifying surgeon, under the Notice of Accidents Act, 1906, when (_a_) causing loss of life or (_b_) due to molten metal, hot liquid, explosion, _escape of gas_ or steam, and so disabling any person as to cause absence throughout at least one whole day from his ordinary work. The following table gives indication of the relative frequency of cases of poisoning from gases and fumes, although some were reported as accidents the result of the unconsciousness induced: +-------------------------------+-------+------+------+------+------+ \| Nature of Gas or Fumes. \| 1912. \| 1911.\| 1910.\| 1909.\| 1908.\| \| (1) \| (2) \| (3) \| (4) \| (5) \| (6) \| +-------------------------------+-------+------+------+------+------+ \|Carbon monoxide \|91 (14 \|64 (6 \|53 (9 \|53 (6 \|55 (5 \| \| (_a_) Blast furnace \|33 (5 \|16 (2 \|19 (7 \|16 \|26 (3 \| \| (_b_) Power (suction, \| \| \| \| \| \| \| producer, Mond, Dowson). \|19 (4 \|31 (1 \|25 \|25 (4 \|19 (2 \| \| (_c_) Coal \|29 (2 \| 6 (2 \| 4 \|11 (1 \| 9 \| \| (_d_) Other \|10 (3 \|11 (1 \| 5 (2 \| 1 (1 \| 1 \| \|Sulphuretted hydrogen \| 6 \| 8 (2 \| 2 \| 5 (2 \| 8 (1 \| \|Carbon dioxide \| 3 (2 \| 1 (1 \| 2 (1 \| 2 (2 \| 4 (3 \| \|Ammonia \| 1 \| 1 (1 \| 2 \| 1 \| 1 \| \|Chlorine and hydrochloric \| \| \| \| \| \| \| acid fumes \| 3 \| 5 (1 \| 3 \| 1 \| 1 \| \|Nitrous fumes \|12 (1 \|18 (2 \|11 \|12 (2 \| 3 (1 \| \|Nitro and amido derivatives of \| \| \| \| \| \| \| benzene \| 9 (1 \|21 \|18 \| 4 \| 2 \| \|Naphtha and benzene \| 3 (1 \| 1 (1 \| — \| 1 (1 \| 2 \| \|Other (Sulphur dioxide, &c.) \| 7 (2 \| 4 \| 4 \| 4 \| 3 \| +-------------------------------+-------+------+------+------+------+ The principal figures are those of all cases, fatal and non-fatal; the small figures relate to fatal cases. Transcriber’s Note: The ‘small figures’ are given here in brackets e.g. (1. [E] The principal numbers relate to cases, the small figures to deaths. Fatal cases not reported in previous years are included as both cases and deaths. Transcriber’s Note: The ‘small figures’ are given here in brackets e.g. (1. [F] Fischer adopts a chemical basis in his classification. His two main subdivisions are (1) inorganic and (2) organic poisons. The sub-divisions of the inorganic poisons are (_a_) non-metallic—chlorine, calcium chloride, hydrochloric acid, potassium chlorate, hydrofluoric acid, carbonic oxide, phosgene, carbon dioxide, cyanogen compounds, ammonia, nitrous fumes, phosphorus, phosphoretted hydrogen, arsenic compounds, antimony compounds, sulphur dioxide, sulphuric acid, sulphuretted hydrogen, carbon bisulphide, chloride of sulphur; and (_b_) metallic—chromic acid and chromates, manganese dioxide, sulphate of nickel, mercury and lead. The sub-divisions of (2) the organic substances are into (_a_) the unsaturated carbon compounds—benzene, petroleum, methyl-, ethyl-, amyl-, and allyl-alcohol, oxalic acid, formal- and acetaldehyde, acrolein, acetone, methyl-bromide and iodide, nitro-glycerin, dimethyl-sulphate and amyl acetate, and (_b_) the aromatic series benzene, nitro-, chloro-nitro-, dinitro-, chloro-dinitro-benzene, phenol, picric acid, phenyl-hydrazine, aniline, and certain aniline colours, para-nitraniline, pyridine, naphthalene, nitro-naphthalene, naphthlyamine, naphthol, benzidine, acridine, turpentine, and nicotine. [G] A Prussian Ministerial Decree, dated March 31, 1892, deals with the preparation of nitrate of mercury. [H] In Great Britain and Ireland the White Phosphorus Matches Prohibition Act became operative from January 1, 1910. In the United States of America a Prohibition Act became operative on July 1, 1913. [I] Reprinted by permission of the Controller of H.M. Stationery Office. [J] _Use of Oxygen Cylinder._—Open the valve gradually by tapping the lever key (which must first be extended to its full length) with the wrist, until the oxygen flows in a gentle stream from the mouthpiece into the patient’s mouth. The lips should not be closed round the mouthpiece. The nostrils should be closed during breathing in, and opened during breathing out. If the teeth are set, close the lips and one nostril. Let the conical end of the mouthpiece slightly enter the other nostril during breathing in, and remove it for breathing out. [K] The suggested regulations made after his inquiry (see p. 149) by Dr. Copeman are: 1. Ferro-silicon should not be sent out from the works immediately after manufacture, but after being broken up into pieces of the size in which it is usually sold, should be stored under cover, but exposed to the air as completely as possible, for at least a month before being despatched from the works. 2. Manufacturers should be required to mark in bold letters each barrel or other parcel of ferro-silicon with the name and percentage grade (certified by chemical analysis) of the material; the name of the works where it is produced; the date of manufacture; and date of despatch. 3. The carriage of ferro-silicon on vessels carrying passengers should be prohibited. When carried on cargo boats it should, if circumstances permit, be stored on deck. If it be considered necessary to store it elsewhere, the place of storage should be capable of being adequately ventilated, and such place of storage should be cut off by airtight bulkheads from the quarters occupied by the crew of the vessel. 4. This regulation should apply to the transport of ferro-silicon on river or canal barges as well as on sea-going vessels. 5. Storage places at docks or at works where ferro-silicon is used should have provision for free access of air, and should be situated at a distance from work-rooms, mess-rooms, offices, &c. [L] Regulations 5-7 contain precautions to be observed in the corroding chambers. APPENDIX REFERENCES PART I PROCESSES OF MANUFACTURE AND INSTANCES OF POISONING GENERAL SURVEY OF POISONING IN CHEMICAL INDUSTRIES [1] Leymann, _Concordia_, 1906, Nos. 7, 8 and 9; [2] Grandhomme, _Die Fabriken der Farbwerke zu Höchst a. M._, Verlag Mahlau, 4th edition. SULPHURIC ACID INDUSTRY [1] _Zeitschr. für. Gewerbe-Hygiene_, 1907, p. 230; [2] Bath, _Zeitschr. f. Angew. Chemie_, 1896, p. 477. HYDROCHLORIC ACID AND SALTCAKE MANUFACTURE [1] _Zeitschr. f. Gewerbe-Hygiene_, 1906, p. 562; [2] _Zeitschr. f. Gew.-Hyg._ 1902, p. 62; [3] Walther in Weyl’s _Arbeiterkrank-keiten_, p. 666. CHLORINE AND BLEACHING POWDER [1] _Zeitschr. für. Gew.-Hyg._, 1906, p. 280; [2] _Concordia_, 1906, No. 8; [3] _Arch. f. Hyg._, vol. 46, p. 322; [4] Egli, _Unf. b. Chem. Arb._, Zurich, 1902, p. 40; [5] Vaubel, _Chemiker Zeitung_, 1903; [6] _Concordia_, 1907, No. 7; [7] Rumpf, _D. Med. Wochenschr._, 1908, vol. 34, p. 1331; [8] Müller, _Vierteljahrsschr. f. Ger. Med. ü öffentl. Sanitätsw._, vol. ix., p. 381; and Roth, _Komp. d. Gewerbekrankh_, p. 205; [9] Klocke-Bochum, _Zeitschr. f. Gew.-Hyg._, 1906, p. 563; [10] Sury Bienz, _Vierteljahrsschr. f. Ger. Med._, 1907, vol. 34, p. 251; [11] Erben, _Handb. d. ärztl. Sachverst_, 1910, vol. ii. p. 266; [12] _Concordia_, 1902, No. 5., and _Vierteljahrsschr. f. öff. Ges. Pfl._, 1902, Suppl. p. 371; [13] Mohr, _D. Med. Wochenschr_., 1902, vol. 28, p. 73; [14] ‘Über Chlorakne,’ _Archiv. f. Dermatol._, 1905, vol. 77, p. 323; [15] Dammer, _Handb. d. Arb. Wohlf._, vol. i. p. 433; [16] _D. Arch. f. Klin. Med._, 1901, vol. 71, p. 370; [17] Schuler, _D. Vierteljahrsschr. f. öffentl. Ges. Pfl._, vol. 31, p. 696; [18] Egli, _Unf. b. Chem. Arb._, Zurich, 1902, pp. 22, 45; [19] Rambousek, _Concordia_, 1910, No. 6. MANUFACTURE AND USE OF NITRIC ACID AND ITS COMPOUNDS [1] Schmitz, _Berl. Klin. Wochenschr._, 1884, vol. 21, p. 428, and Becker, _Aerztl. Sachv. Ztg._, 1899, vol. v. p. 277; [2] _Concordia_, 1908, No. 23, p. 498; [3] Schmieden, _Zentralbl. f. Klin. Med._, 1892, No. 11; Kockel, _Vierteljahrsschr. f. Ger. Med._, 1898, vol. 15; [4] Egli, _Unf. b. chem. arb._, 1903, p. 52; [5] _Chem. Industrie_, 1905, p. 444; [6] _Chem. Industrie_, 1905, p. 445; [7] _Berl. Klin. Wochenschr._, 1886, vol. 23, p. 417; [8] _Komp. d. Gewerbekrankheiten_, p. 62; [9] _Intern. Uebers. über Gew.-Hyg._, 1907, p. 76. PHOSPHORUS AND LUCIFER MATCH MANUFACTURE [1] _Die Phosphornekrose, ihre Verbreitung in Oesterreich_, Wien, 1907; [2] Friedrichs, in _Arb. d. Ung. Ver. f. ges. Arbeiterschutz_ 1908, vol. 4, pp. 1-176; [3] v. Jaksch, _Handb. d. ärztl. Sachv.-Tät._, 1909, vol. 7, p. 239; and Lévai, _W. Klin. Rundsch._, 1900, vol. 14, p. 33, and Dearden, _Brit. Med. Journ._, 1899, vol. 1, p. 92; [4] Wodtke, _Vierteljahrsschr. f. ger. Med. und öffentl. Sanitätsw._, vol. 18, p. 325. CHROMIUM COMPOUNDS [1] Hermanni, _Münch med. Wochenschr._, 1901, No. 14, and Wodtke, _loc. cit._, p. 325; [2] _Zeitschr. f. Gew.-Hyg._, 1908, p. 161; [3] Wutzdorff und Heise, _Arb. a. d. Kais. Ges. Amt._, vol. xiii.; [4] _Zeitschr. f. öffentl. Ges. Pfl._, 1894; [5] Burns, _Ann. Rept. of C. I. of F._, 1903; [6] Neisser, _Intern. Uebers. über Gew.-Hyg._, 1907, p. 92. MANGANESE COMPOUNDS [1] Couper, _Journ. de Chimie_, vol. 3, series ii.; [2] _Münch. med. Wochenschr._, 1901, p. 412; [3] Embden, _D. med. Wochenschr._, vol. 27, p. 795. PETROLEUM AND BENZINE INDUSTRY [1] Berthenson, _D. Vierteljahrsschr. f. öffentl. ges.-Pfl._, 1898, vol. 30, p. 315; [2] _Virchow’s Archiv_, vol. 112, p. 35; [3] Felix, _D. Vierteljahrsschr. f. öffentl. ges.-Pfl._, 1872; [4] _Lancet_, 1886, p. 149; [5] _Ramazzini_, 1908, vol. 2, p. 226; [6] Dorendorf, _Zeitschr. f. Klin. Med._, 1901, p. 42; [7] _Brit. Med. Journ._, 1903, p. 546, and _ibid._, 1908, p. 807; [8] _Zeitschr. f. Gew.-Hyg._, 1907, p. 157; [9] Wichern, _Zeitschr. f. Gew.-Hyg._, 1909, Nos. 3 and 4; [10] Mitchell, _Med. News_, iii., p. 152; _Ann. d’Hyg. publ._, vol. 24, p. 500; Arlidge, _Dis. of Occupation_; _Revue d’Hygiène_, 1895, p. 166; Neisser, _Intern. Uebers. f. Gew.-Hyg._, 1907, p. 96. SULPHURETTED HYDROGEN GAS [1] _Chem. Ind._, 1908, p. 323; [2] Pfeiler, _D. Vierteljahrsschr. f. öffentl. Ges.-Pfl._, 1904; [3] _Lehre v. d. schädl. u. gift. Gasen_, p. 274. CARBON BISULPHIDE [1] _Archiv f. Hyg._, vol. 15, pp. 125-141; [2] Santesson, _Archiv f. Hyg._, vol. 31, p. 336; [3] _Chem. Ind._, 1905, p. 442; [4] _Zeitschr. f. Gew.-Hyg._, 1908 and 1909; [5] _Arch. f. Hyg._, xx., p. 74; [6] _Die Schwefelkohlenstoffvergiftung der Gumniarbeiter_, Leipzig, Veit & Comp., 1899; [7] _Ann. d’Hyg. publ._, 1863. ILLUMINATING GAS [1] _Krankheiten des Arbeiter_, 1871; [2] _Gewerbepathologie_, 1877; [3] _Weyl’s Handb. d’Hyg._, 1894, vol. 8; [4] Sprenger and Albrecht: Albrecht’s _Gewerbehygiene_, 1896; [5] Jehle, ‘Hygiene der Gasarbeiter,’ _Zeitschr. f. Gew.-Hyg._, 1901, pp. 245 and 261; [6] Schütte: ‘Krankheiten der Gasarbeiter,’ Weyl’s _Arbeiterkrankheiten_, 1908, p. 239; [7] Heymann’s Verlag, 1910; [8] _Zeitschr. f. Gew.-Hyg._, 1909, No. 12; [9] _Chem. Ind._, 1905, p. 442; [10] Egli, _Über d. Unf. b. Chem. Arb._, Zurich, 1903; [11] _Gewerb. techn. Ratgeber_, 1906, p. 96. COKE OVENS [1] Hesse, _Concordia_, 1909. POWER GAS, SUCTION GAS, &C. [1] _Zeitschr. f. Gew.-Hyg._, 1906, p. 250; 1909, p. 297; 1906, p. 19; [2] _Gewerbl. techn. Ratgeber_, 1906, p. 297; [3] Nottebohm, _Socialtechnik_, 1907, vol. 7, p. 80; [4] Finkelstein, _Jahr. d. Peych._, 1897, vol. 15, p. 116; [5] Jokote, _Arch. f. Hyg._, 1904, vol. 49, p. 275. AMMONIA [1] _Ber. pr. Gew. Insp._, 1904; [2] Egli, _loc. cit._, No. 2, p. 48; [3] _Lehre v. d. schädl. u. gift. Gasen_, p. 274; [4] _Zeitschr. f. gew.-Hyg._, 1909, p. 242; [5] _Berl. Klin. Wochenschr._, 1908. CYANOGEN COMPOUNDS [1] _Handb. d. Hyg._, vol. 8, p. 897; [2] Merzbach, _Hyg. Rundsch._, 1899, No. 1; [3] _Zeitschr. f. Med. Beamte_, 1907, vol. 20, p. 825; [4] Kockel, _Vierteljahrsschr. f. ger. Med._, 1903, vol. 26; [5] Erben, _Vergiftungen_, ii. p. 204. TAR AND ITS DERIVATIVES [1] Lewin, _Münchn. med. Wochenschr._, 1907; [2] Santesson, _Skand. Arch. f. Physiol._, 1900, vol. 10, pp. 1-36; [3] _Concordia_, 1901, p. 287 Jahresber. d. Staatl. Aufsichtsbeamten über Unfallverbütung, 1909; [4] Arb. d. Hamb. Gewerbeinspektoren, 1909; [5] Greiff, _Vierteljahrsschr. f. ger. Med._, 1890. COAL TAR COLOURS [1] _Die Fabriken der Farbwerke vorm. Meister Lucius & Brüning zu Höchst a. M._, 1896; [2] _Concordia_, 1910, p. 355; [3] _Vierteljahrsschr. f. öffentl. Ges.-Pfl._, Supplem. pro 1902, p. 371; [4] Schröder, _Vierteljahrsschr. f. ger. Med._, 1903, p. 138; Rump, _Zeitschr. f. Med. Beamte_, 1903, p. 57; [5] Brat, _D. med. Wochenschr._, 1901, Nos. 19 and 20; [6] Mohr, _D. med. Wochenschr._, 1902; [7] _Zeitschr. f. Gew.-Hyg._, 1908, p. 383; [8] Hanke, _W. Klin. Wochenschr._, 1899, vol. 12, p. 725; Frank, _Beiträge zur Angenheilk._, 1898, vol. 31, p. 93; Silex, _Zeitschr. f. Angenheilk._, 1902, p. 178; [9] Dearden, _Brit. Med. Journ._, 1902, vol. 2, p. 750; [10] _Ann. Rept. of C. I. of F._, 1905, p. 165; [11] _Münch, med. Wochenschr._, 1907; [12] Erdmann, _Arch. f. exp. Path._, 1905, vol. 53, p. 401. FERRO-SILICON _Nature, Uses and Manufacture of Ferro-silicon_, by S. M. Copeman, S. R. Bennett, and H. W. Hake. London. 1909. Cd. 4958. LEAD AND ITS COMPOUNDS Legge and Goadby, _Lead Poisoning and Lead Absorption._ Edward Arnold. 1912. [1] Wächter, _Die gewerbliche Bleivergiftung im Deutschen Reich_, 1908, p. 36; [2] _XIV. Intern. Kongr. f. Hyg. und Dem._, 1907, vol. 2, p. 746; [3] Rambousek, _Concordia_, 1910; [4] Müller, _Die Bekämpfung der Bleigefahr in Bleihütten_, Fischer, 1908, 156; [5] Frey, _Die Zinkgewinning und ihre Hygiene_, Hirschwald, Berlin, 1907; [6] Wächter, _Die gew. Bleivergiftung_, 1908, Braun, Karlsruhe; [7] Clayton, _Brit. Med. Journ._, 1906, vol. 1, p. 310; [8] _Bericht an die Intern. Vereinigung für Arbeiterschutz_, 1908. MERCURY AND ITS COMPOUNDS [1] Laureck, _Weyl’s Arbeiterkr._, p. 62; [2] Giglioli, Ramazzini, 1909, vol. 3, p. 230. ARSENIC AND ITS COMPOUNDS [1] _Zeitschr. f. Gew.-Hyg._, 1902, p. 441; [2] Prölss, _Friedreich’s Bl. f. ger. Med._, 1901, p. 176. ANTIMONY [1] _Vergiftungen_, vol. ii. p. 285. BRASS [1] _Vierteljahrsschr. f. ger. Med._, 1906, p. 185; [2] _Arch. f. Hyg._, 1910, vol. 72, p. 358. PART II PATHOLOGY AND TREATMENT OXYGEN INHALATION IN INDUSTRIAL POISONING Brat, ‘Bedeutung der Sauerstofftherapie in der Gewerbehygiene, _XIV. Intern. Kongr. f. Hyg. u. Dem._ und _Zeitschr. f. Gew.-Hyg._ 1908, Heft 13, S. 305; Dräger, ‘Zur Physiologie des Rettungsapparates mit komprim. Sauerstoff, _I. Intern. Kongr. f. Rett.-Wes., Frankfurt a. M._ 1908, und _Fabrikfeuerwehr_ 1908, Heft 19, S. 74; Klocke, ‘Die Bedeutung der Sauerstoffinhalationen in der Gewerbehygiene,’ _Zeitschr. f. Gew.-Hyg._ 1906, Heft 20, S. 559; Dräger, ‘Neue Untersuchungen über die Erfordernisse eines zur Arbeit brauchbaren Rettungsapparates,’ _Zeitschr. f. Gew.-Hyg._ 1905, S. 49; Klocke, ‘Sauerstoffrettungsapparate,’ _Soz. Techn._ 1908, Nr. 14, S. 272. HYDROFLUORIC ACID POISONING Egli, _Unf. b. chem. Arb._, I, S. 23, und II, S. 45; Rambousek, ‘Gewerbekrankh. in Böhmen,’ _Concordia_ 1910, Heft 6, und _Amtsarzt_ 1910, Heft 7. SULPHURIC ACID AND SULPHUR DIOXIDE Ogata, _Arch. f. Hyg._, Bd. 2; Lehmann, _Arch. f. Hyg._, Bd. 18, S. 180 ff; Klocke ‘(SO₂-Vergiftung und O-Inhal.),’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 562 und 617; ‘SO₂-Absorption beim Atemprozess,’ Chem. Ztg. 1909, S. 246; ‘Tod durch Einatmung von Schwefelsäuredampf,’ _Zeitschr. f. Gew.-Hyg._ 1907, S. 430; ‘Schwefel-dioxydvergiftung in England,’ _Concordia_ 1909, Heft 5, S. 105; ‘Schwefels.-Vergiftung, _Chem. Ind._ 1909 _(Ber. d. Berufsgen. f. chem. Ind. pro_ 1908, S. 26); Egli, _Unf. b. chem. Arb._, ii, S. 52. NITRIC ACID AND NITROUS FUMES ‘Verg. durch nitrose Gase in einer Zellulosefabrik,’ _Zeitschr. f. Gew.-Hyg._ 1908 Heft 24, S. 565; ‘Behandlung von Nitrosevergiftungen durch Sauerstoffinhalationen,’ _Zeitschr. f. Gew.-Hyg._ 1908, Heft 20, S. 560; ‘Behandlung durch Chloroform,’ _Zeitschr. f. Gew.-Hyg._ 1904, Heft 10, S. 226, und 1907, Heft 8, S. 183; ‘Vergiftungen durch nitrose Gase (Zusammenfassung),’ Holtzmann, _Concordia_, 1908, Nr. 23, S. 498. CHLORINE, BROMINE, AND IODINE Leymann, _Arch. f. Hyg._, Bd. 7, S. 231; Binz, _Arch. f. exp. Path._, Bd. 13; _Vierteljahrsschr. f. ger. Med._ 1888, S. 345; Lehmann, _Arch. f. Hyg._, Bd. 34, S. 302, und _Arch. f. Hyg._, Bd. 17, S. 336; _Arch. f. exp. Path. u. Ph._ 1887, S. 231; Egli, _Unf. b. chem. Arb._, II, S. 51; Chlorverg., _Chem. Ind._ 1907, S. 347, 1908, S. 325; Neisser, _Intern. Uebers. über Gew.-Hyg._, I, S. 94; ‘Chlorverg. in England,’ _Concordia_ 1909, S. 105. _Literatur Über Chlorakne._—Herxheimer, _Münchn. med. Wochenschr._ 1899 S. 278; Bettmann, _D. med. Wochenschr._ 1901, S. 437; Lehmann, _Arch. f. Dermatol._ 1905, S. 323; Leymann, ‘Erk.-Verh. der chem. Grossind.,’ _Concordia_ 1906, Nr. 7-9; Holtzmann, _D. Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1907, Bd. 39, S. 258. CHLORIDES OF PHOSPHORUS Vaubel, _Chem. Ztg._ 1903; Leymann, _Concordia_ 1906, Nr. 7; Egli, _Unf. b. chem.-Arb._ 1902, S. 49; Rumpf, _D. med. Wochenschr._ 1908, Bd. 34, S. 1331. CHLORIDE OF SULPHUR Lehmann, _Arch. f. Hyg._ 1894, Bd. 20, S. 26; Leymann, _Concordia_ 1906, Heft 7. AMMONIA Lehmann, ‘Verauche über die Wirkung,’ _Arch. f. Hyg._, Bd. 5; ‘Vers. über die Resorption,’ _Arch. f. Hyg._, Bd. 17 u. 67; ‘Versuche über die Gewöhnung,’ _Arch. f. Hyg._, Bd. 34; Lewin, ‘Tödl. Ammoniakverg. in einer chem. Fabrik, Berl. klin. Wochenschr. 1908; ‘Tödl. Ammoniakverg.,’ _Zeitschr. f. Gew.-Hyg._ 1909, Wr. 9, S. 242; ‘Ammoniakverg. in der Kälte-Ind.’ LEAD POISONING ‘Vorkommen der Bleivergiftung. Bleierkrankungen in der Bleihütte Braubach,’ _Zeitschr. f. Gew.-Hyg._ 1909, S. 291; _Bleivergiftungen in gewerbl. u hüttenmänn. Betrieben_ (_Oesterreichs_), herausgegeben vom k. k. Arbeitsstat. Amt: I. Erhebungen in Blei- und Zinkhütten; II. Erhebungen in Bleiweiss- und Bleioxydfabriken; III. Expertise, betreffend die Blei- und Zinkhütten; IV. Expertise, betreffend die Bleiweiss- und Bleioxydfabriken; V. Erhebungen in Farbenfabriken und Betrieben mit Anstreicher-, Lackierer- und Malerarbeiten; VI. Expertise hierzu; VII. Erhebungen und Expertise in Buch- und Steindruckereien und Schriftgisseereien (alle Teile erschienen bei Alfr. Hölder, Wien 1905-1909). Frey, _Zinkgewinnung im oberschles. Industriebezirk_, Berlin 1907, Verlag Hirschwald; Leymann, _Die Bekämpfung der Bleigefahr in der Industrie_, Verlag Fischer, Jena 1908; Müller, _Die Bekämpfung der Bleigefahr in Bleihütten_, Verlag Fischer, Jena 1908; Wächter, _Die gewerbl. Bleiverg. im Deutschen Reich_, Verlag Braun, Karlsruhe 1908; Chyzer, _Les intoxications par le plomb se présentant dans la céramiquen en Hongrie_, Schmidl, Budapest 1908; Kaup, _Bleiverg. in der keramischen Ind._, als Manuskript gedruckt, D. Sekt. Ges. f. Soziale Reform; Teleky, ‘Beitrag z. H. d. Erzeug. v. ord. Töpferware usw. in Oesterr.,’ _Arbeiterschutz_, 1908, Nr. 19, 20; De Vooys, _Bleiverg. in der niederl. keram. Ind._ (Nederl. Vereen. voor wettelijke Beseherming van arbeiders 1908); Kaup, _Bleiverg. in österr. Gew.-Betrieben_, Schriften des österr. Vereines für Arbeiterschutz 1902, Heft 3; Sommerfeld, ‘Zur Bleiweissfrage,’ _Soz. Praxis_ 1902, Nr. 8; Friedinger, ‘Sanit. Verh. in d. Buchdr.,’ _Soz. Praxis_ 1902, Nr. 9; Wutzdorff, _Bleiverg. in Zinkhütten_, Arb. a. d. Kais. Ges.-Amte, Bd. 17, S. 441; Blum, _Unters. über Bleiverg._, Frankfurt a.M. 1900, _Vierteljahrsschr. f. öffentl. Ges.-Pfl._, Suppl. 32, S. 630; Panwitz, _Bleiverg. in Buchdruckereien_, Veröff. d. Kais. Ges.-Amtes 1897, S. 503; Teleky, ‘Bleiverg. bei Fransenknüpferinnen,’ Ref. _Zeitschr. f. Gew.-Hyg._ 1907, Nr. 1, S. 13; ’ Bleierkrankung und Bekämpfung ders., Literatursammlung,’ _Zeitschr. f. Gew.-Hyg._ 1904, Nr. 6, S. 131; Teleky, ‘Die gewerbl. Bleiverg. in Oesterreich,’ _Soz. Techn._ 1909, Nr. 17, S. 333; Bleiverg. (Legge), Verh. d. II. Intern. Kongr. f. Gewerbekrankh. in Brüssel 1910; Bleiverg. in Böhmen (Rambousek), Concordia 1910, Nr. 7, Amtsarzt 1910, Nr. 6; Abelsdorff, Statistik d. Bleiverg., Concordia 1910, Heft 17, S. 359; Wutzdorff, ‘Bleiverg. in Akkumulatoreniabr.,’ _Arb. a. d. Kais. Ges.-Amte_ 1898, Bd. 15, S. 154; Rasch, ‘Ueber Bleiverg. d. Arb. in Kachelfabr.,’ _Arb. a. d. kais. Ges.-Amte_ 1898, Bd. 14, S. 81. GENERAL LITERATURE ON PATHOLOGY AND TREATMENT OF LEAD POISONING Jores, ‘Die allg. pathol. Anatomie der chron. Bleiverg. des Kaninchens,’ _Beiträge z. path. Anat. u. allg. Path._ 1902, Bd. 31, S. 183; Glibert, _Le saturnisme experimental, extrait d. rapp. ann. de l’insp. du travail en 1906_, Bruxelles, 1907. Rambousek, ‘Die Pathol. d. Bleiverg.’ in Leymann’s _Bekämpfung d. Bleigef._, S. 15, Velag Fischer, Jena 1908; _Die Verhütung d. Bleigefahr_, Verlag Hartleben 1908; Blum, ‘Unters. über Bleiverg., Frankfurt a.M. 1900,’ _Vierteljahrsschr. f. öffentl Ges.-Pfl._, Suppl. 32, S. 630; Elschnig, ‘Sehstörungen b. Bleiverg.,’ Ges. d. Aerzte, Wien, Sitzung v. 15. April 1898, und _Wiener med. Wochenschr._ 1898, S. 1305; ‘Neuere Forschungen über Bleiverg.,’ _Zeitschr. f. Gew.-Hyg._ 1909, S. 629; Seeligmüller, ‘Einfl. d. Bleies auf den Frauenorganismus usw.,’ _Berl. klin. Wochenschr._ 1901, S. 842; Bernhardt, ‘Zur Pathol. d. Bleilähmung,’ _Berl. klin. Wochenschr._ 1900, S. 26; Rambousek, ‘Die Bleierkrankung,’ _Zeitschr. f. ärztl. Fortbildung_ 1909, Nr. 7; Israel, ‘Obd.-Befund b. Bleiverg.,’ _Berl. klin. Wochenschr._ 1895, S. 575; Gumpertz, Bernhardt, ‘Anom. d. elektr. Erregb. b. Bleiverg.,’ _Berl. klin. Wochenschr._ 1894, S. 372 u. S. 284; Jolly, ‘Sekt.-Befund b. Bleilänmung, Entart. d. Gangl.,’ _Berl. klin. Wochenschr._ 1893; Miura, ‘Ueber die Bedeutung des Bleinachweises auf der Haut Bleikranker,’ _Berl. klin. Wochenschr._ 1890, S. 1005; Mattirolo, ‘Behandlung d. Bleikolik mit Erythroltetranitrat,’ _Wiener med. Presse_ 1901, _Wiener med. Wochenschr._ 1901, S. 2171; Oddo und Silbert, ‘Ausscheidung des Bleis,’ _Revue med._ 1892, Nr. 4, und _Wiener med. Presse_ 1892, S. 1182; Mosse, ‘Veränderungen d. Gangl. coeliac. bei exper. Bleikolik,’ _Wiener klin. Wochenschr._ 1904, S. 935; Escherich, ‘Zwei Fälle v. Bleilähmung b. Kindern (Peroneuslähmung.),’ _Wiener klin. Wochenschr._ 1903, S. 229; Variot, ‘Ein Fall v. Bleilähmung b. einem Kinde (Peroneuslähmung),’ _Gaz. des Hôp._ 1902, S. 482, und _Wiener klin. Wochenschr._ 1902; Sorgo, ‘Progress. Muskelatrophie nach Bleiverg.,’ _Weiner med. Wochenschr._ 1902, S. 919; Variot, ‘Bleiverg. b. einem Kinde, Parese d. unt. Extrem.,’ _Wiener med. Wochenschr._ 1902, S. 2056; Rome, ‘Bleiverg. b. Kindern,’ _La trib. med._ 1902, Nr. 39, und _Wiener med. Wochenschr._ 1902, S. 2391; Layal, Laurencon, Rousel, ‘Erscheinungen der Pylorusstenose b. Bleiverg.,’ _Wiener med. Wochenschr._ 1897; Macfairlain, ‘Chloroformbehandlung bei Bleikolik,’ _Wiener med. Wochenschr._ 1895; Bechtold, ‘Spast. Spinalparalyse b. Bleiverg.,’ _Med. chir. Zentralbl._ 1904, Nr. 40; Oliver, ‘Lead-poisoning, &c.,’ _Lancet_, 1891, S. 530; Heymann, ‘Lähmungen d. Kehlkopfmuskeln b. Bleiverg.,’ _Arch. f. Laringol._ 1896, S. 256; Clayton, ‘Ind. lead-poisoning,’ _Brit. med. journ._ 1906, S. 310; Taylor, ‘Bleiamblyopie,’ _Lancet_ 1898, S. 742; Seeligmüller, ‘Zur Pathol. d. chron. Bleiverg.,’ _D. med. Wochenschr._ 1902, S. 317; Lewin, ‘Puls b. Bleiverg.,’ _D. med. Wochenschr._ 1897, S. 177; Walko, ‘Erkr. d. Magens b. chron. Bleiverg.,’ _Münchn. med. Wochenschr._ 1907, S. 1728; Tielemanns, _Parotiserkr. b. Bleiverg._, Monogr., Paris 1895; Borgen, ‘Blutdruckbestimmungen b. Bleikolik,’ _D. Arch. f. klin. Med._ 1895, S. 248; Klieneberger, ‘Intox. saturn. und Nephritis sat.,’ _München. med. Wochenschr._ 1904, S. 340; Bach, ‘Augenerkr. b. Bleiverg.,’ _Arch. f. Augenheilk._ 1893, S. 218; Redlich, ‘Tabes und chron. Bleiverg.,’ _Wiener med. Wochenschr._ 1897, S. 801; Seifert, ‘Kehlkopfmuskellähmung b. Bleiverg.,’ _Berl. klin. Wochenschr._ 1884, S. 555. LITERATURE ON BLOOD CHANGES IN LEAD POISONING Schmidt, ‘Die Bleiverg. und ihre Erkennung,’ _Arch. f. Hyg._ 1907, Bd. 63, Heft 1; Galperin-Teytelmann, _Die basophilen Granula der roten Blutk. b. Bleairbeitern, Ing. Diss._, Bonn 1908; Carozzi, _Reperti ematol. e loro valore statistico nel saturn. prof. Corr. sanitar._ 1909, Bd. 20, Nr. 5 u. 6; Gilbert, _Le saturnisme exp._, Bruxelles, 1907; Rambousek, ‘Beitrag z. Pathol. d. Stoffw. und d. Blutes b. Bleiverg., _Zeitschr. f. exp. Path. und Therap._ 1910, Bd. 7; Moritz, ‘Beziehungen der basophilen Granula zu den Erythrozyten,’ _Münchn. med. Wochenschr._ 1901, Nr. 5; _St. Petersburger med. Wochenschr._ 1901, Nr. 26, 1903, Nr. 50; _Verh. d. I. Intern. Kongr. f. Arb.-Krankh. in Mailand_ 1906, _Atti del congresso_, S. 601-607; Trautmann, ‘Blutunters. b. Bleiverg.,’ _Münchn. med. Wochenschr._ 1909, S. 1371; Grawitz,’Ueber die körn. Degenerat. d. roten Blutkörperchen,’ _D. med. Wochenschr._ 1899, Nr. 44; ‘Die klin. Bedeutung und exp. Erzeugung körn. Degener. in den roten Blutkörperchen,’ _Berl. klin. Wochenschr._ 1900, Nr. 9; Hamel, ‘Ueber die Beziehungen der körn. Degener. der roten Blutkörperchen zu den sonst. morph. Veränd. des Blutes mit besonderer Berücks. d. Bleiintox.,’ _D. Arch. f. klin. Med._ 1900, Bd. 67; Frey, ‘Beitrag zur Frühdiagnose v. chron. Bleiverg.,’ _D. med. Wochenschr._ 1907, Nr. 6; Grawitz, _Klin. Pathol. des Blutes_, Leipzig 1906, S. 120 ff.; Naegeli, ‘Ueber die Entstehung der basoph. gek. roten Blutk.,’ _München. med. Wochenschr._ 1904, Nr. 5; Schmidt, ‘Zur Frage d. Entstehung d. basoph. Körner,’ _D. med. Wochenschr._ 1902, Nr. 44; _Exp. Beiträge z. Pathol. d. Blutes_, Jena 1902; ‘Ein Beitrag. z. Frage d. Blutregen.,’ _Münchn. med. Wochenschr._ 1903, Nr. 13; Erben, ‘Chem. Zusammensetzung d. Blutes b. Bleiverg.,’ _Zeitschr. f. Heilkunde_, 1905, S. 477. LITERATURE ON CHANGES IN METABOLISM IN LEAD POISONING Preti, ‘Beitrag z. Kenntn. d. Stickstoffums. b. Bleiverg.,’ 1909, S. 411; Rambousek, ‘Beitrag z. Pathol. d. Stoffw. und d. Blutes,’ _Zeitschr. f. exp. Path. und Ther._ 1910, Bd. 7; ‘Pathol. d. Bleiverg.’ in Leymann’s _Bekämpfung d. Bleigefahr_, Fischer, Jena 1909; Minkowski, _Die Gicht_, Wien, 1903, Holders Verlag.; Schittenhelm und Brugsch, ‘Zur Stoffwechselpathol. d. Gicht,’ _Zeitschr. f. exp. Path. und Ther._, Bd. 4, S. 494-495. LITERATURE ON TOXICITY OF VARIOUS LEAD COMPOUNDS Blum, ‘Unters. über Bleiverg., Frankfurt a. M. 1900,’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._, Suppl. 32, S. 630; Rambousek, _Die Verhütung der Bleigefahr_, Verlag Hartleben 1908; Biondi und Rambousek, ‘Polemik über die Ungiftigkeit d. Bleisulfids,’ _I. Intern. Kongr. f. Gew.-Krankh. in Mailand_ 1906, _Atti del congresso_, S. 617-622; Lehmann, ‘Hyg. Unters. über Bleichromat,’ _Arch. f. Hyg._ 1893, Bd. 16, S. 315. ZINC Schlockow, ‘Ueber ein eigenartiges Rückenmarksleiden bei Zinkhüttenarbeitern,’ _D. med. Wochenschr._ 1879, S. 208; Tracinsky, ‘Die oberschlesische Zinkindustrie usw.,’ _D. Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1888, Bd. 20, S. 59; Seiffert, ‘Erkr. d. Zinkhüttenarb. usw.,’ _ibidem_ 1897, Bd. 31, S. 419; Lehmann, ‘Beiträge z. hygien. Bedeutung d. Zinks,’ _Arch. f. Hyg._ 1897, Bd. 28, S. 300; Neuere Arbeiten: Frey, _Die Zinkgew. im oberschl. Industriebez.-usw._,’ Verlag Hirschwald-Berlin 1907 und _Zeitschr. f. Gew.-Hyg._ 1907, Nr. 16, S. 376; Sigel, ‘Das Giesserfieber u. seine Bekämpfung,’ _Vierteljahrsschr. f. ger. Med._ 1906, Bd. 32, S. 173; Lehmann, ‘Giess- oder Zinkfieber,’ _Arch. f. Hyg._ 1910, Bd. 72, S. 358. MERCURY Schönlank, _Fürther Spiegelfabriken_ 1888 (Monogr.); Wollner, ‘Quecksilberspiegelfabrik in Fürth,’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._, Bd. 19, 3, S. 421, und _Münchn. med. Wochenschr._ 1892, Bd. 39, S. 533; Stickler, ‘Hutfabrikation, 1886,’ _Revue d’Hygiène_, VIII, S. 632; Charpentier, ‘Spiegelfabrik,’ _Annal. d’hyg. publ._, avril 1885, S. 323; Henke, _Quecksilberverg. in Hutfabriken_, Knauer, Frankfurt 1889; Wittzack, ‘Quecksilberverg. b. d. Spiegelbel. usw.,’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1896, S. 216; Donath, ‘Quecksilberverg. in Gluhlampenfabriken,’ _Wiener med. Wochenschr._ 1894, 8. 888; Renk, ’ Quecksilberverarbeitung,’ Arb. a. d. Kais. Ges.-Amte, Bd. 5, Heft I; Letulle, ‘Hasenhaarschneiderei,’ _Revue d’Hyg._, XI, S. 40; Ueber Hasenfellbeize, _Zeitschr. f. Gew.-Hyg._ 1909, S. 821; _Sozialtechn._ 1910, S. 39; ‘Quecksilberverg. in d. Glühlampenind.,’ _Zeitschr. f. Gew.-Hyg._ 1908, S. 469; ‘Quecksilberverg. in Amiata in Italien (ausführliche Schilderung der Symptome schwerer Quecksilberverg.),’ Giglioli, im _Ramazzini_ 1909, Bd. 3, S. 230, und ‘Demonstration am II. Ital. Kongr. f. Arbeiterkrankh. in Florenz 1909,’ ref. _Zeitschr. f. Gew.-Hyg._ 1909, S. 289, und _Chem. Ztg._, Repert., 1909, S. 411; ‘Quecksilberverg. in Hutfabriken in Italien,’ _Ramazzini_, 1909, S. 230; Laureck, in Weyls _Handb. d. Arb.-Krankh._ 1909, S. 62. MANGANESE Couper, _Journ. de chim._, 1837, Bd. 3, S. 2; Jaksch, _Münchn. med. Wochenschr._ 1901, S. 602; Embden, _D. med. Wochenschr._, Bd. 27, S. 795, u. _Münchn. med. Wochenschr._ 1901, S. 1852; Jaksch, ‘Ueber Manganintoxikationen u. Manganophobie,’ _Münchn. med. Wochenschr._ 1907, Bd. 54, S. 969; Hauck, ‘Manganismus.’ Vortrag auf dem XIV. Intern. Kongr. f. Hyg. u. Dem., Berlin 1907, Bd. 4, S. 337; Friedel, D. med. Wochenschr. 1909, S. 1292. CHROMIUM Delpech et Hillaret, _Annal. d’Hyg. publ._ 1876; Viron, _Contrib. à l’étude phys. et tox. de quelques prép. chromés_, Paris, 1885; Burghardt, ‘Chromverg. in der Zündhölzchenindustrie,’ _Charité Annalen_, XXIII, 1898, S. 189; Wutzdorff, ‘Die in den Chromatfabriken beobachteten Gesundheits-schädigungen.’ NICKEL Nickelkrätze: ‘Jahresberichte d. preuss. Reg.- u. Gewerberäte für das Jahr 1907,’ _Zeitschr. f. Gew.-Hyg._ 1908, Nr. 8, S. 185, u. 1909, Nr. 14, S. 374; Klocke, _Soz. Med. u. Hyg._ 1910, Bd. 5, Nr. 2. NICKEL CARBONYL H. W. Armit: _Journ. of Hygiene_, 1907, p. 524, and 1908, p. 565; Vahlen, _Arch. exp. Pathol. u. Ph._ 1902, Bd. 48, S. 117; Mittasch, _Arch. f. exp. Path._ 1903, Bd. 49, S. 367; Langlois, _Compt. rend. de la soc. de Biol._ 1891, S. 212. SILVER (ARGYRIA) Schubert, ‘Argyrie bei Glasperlenversilberern,’ _Zeitschr. f. Heilk._ 1895, Bd. 16, S. 341; Lewin, ‘Lokale Gewerbeargyrie,’ _Berl. klin. Wochenschr._ 1886, S. 417; Blaschko, _Arch. f. mikr. Anatomie_, Bd. 27, S. 651. ARSENIC ‘Arsenverg. in der Delainage,’ _Zeitschr. f. Gew.-Hyg._ 1906, Nr. 3, S. 71; ‘Arsenikverg. in der Ind.,’ _Zeitschr. f. Gew.-Hyg._ 1907, S. 353, und 1903, S. 476; ‘Arsenikverg. in England, nach den Ber. der engl. Gew.-Insp.,’ _Concordia_ 1909, Nr. 5, S. 105; Egli, _Unf. b. chem. Arb._, II, S. 51. PHOSPHORUS Lorinser, _Med. Jahrb. d. österr. Staates_, 1845, Bd. 51, S. 257; und _Zeitschr. d. Gesellsch. d. Aerzte in Wien_, 1851, Bd. 55, S. 22; Geist u. Bibra, _Die Krankh. d. Arb. in der Phosphorzündholzfabrik_, Erlangen 1847; Wegner, _Virch.-Arch._ 1872, Bd. 55, S. 11; Magitot, _Revue d’Hygiène_, 1895, Bd. 17, S. 201; Kollin, ‘Oberkiefernekrose,’ _Zentralbl. f. inn. Med._ 1889, S. 1279; Dearden, ‘Osseous fragilit. am. workers in luc. match fet.,’ _Brit. Med. Journ._ 1899, S. 92; Lévai, ‘Ueber Phosphornekrose,’ _Wiener klin. Rundsch._ 1900, S. 33; ‘Ein Fall von Phosphornekrose 19 Jahre nach der Arbeit in Zündhölzchenfabriken,’ _Wiener klin. Rundsch._ 1896, Nr. 29, S. 503; Stockman, _Brit. Med. Journ._ 1899; Stubenrauch, _Arch. f. klin. Chir._ 1899, Heft 1, und _Samml. klin. Vortr._ 1901, Nr. 303; Röpke, _Zeitschr. d. Zentralst. f. Arb.-Wohlf.-Einr._ 1901, Nr. 1; ‘Phosphorverg. in England (nach den Berichten der engl. Gew.-Insp.),’ _Concordia_, 1909, Nr. 5, S. 105; Teleky, ‘Die Phosphornekrose in Oesterreich,’ _Schriften der Oesterr. Gesellsch. f. Arbeiterschutz_, Heft 12, Verlag Deuticke 1907; Friedrich, ‘Die Phosphorverg. in Ungarn’ (in ungar. Sprache), _Schriften der Ungar. Gesellsch. f. Arbeiterschutz_, Heft 4, Budapest 1908. PHOSPHORETTED HYDROGEN Schulz, _Arch. f. exp. Path. u. Phys._ 1890, Bd. 27, S. 314; Dietz, ‘Phosphorwasserstoffverg. bei einem Phosphorfabrikarb.,’ _Arch. f. Hyg._ 1904, Bd. 49. Spezielle Literatur über Phosphorwasserstoffvergiftung durch Ferrosilizium: Bahr, Lehnkering, ‘Phosphorverg. durch Ferrosiliz.,’ _Vierteljahrsschr. f. ger. Med._ 1906, S. 123; _Jahresber. d. engl. Gew.-Insp. f. d. J._ 1907 (vgl. _Soz. Techn._ 1908, Bd. 7, S. 689 und 690); Oliver, _Diseases of Occupation_, 1908; H. Le Chatelier, _Ann. Min._ 1909, Bd. 15, S. 213; vgl. ferner _Zeitschr. f. Gew.-Hyg._ 1908, S. 574, und S. 181. HYDROGEN SULPHIDE Lehmann, ‘Exp. Studien über Schwefelw.,’ _Arch f. Hyg._, Bd. 14, S. 142; ‘Gewöhnung an Schwefelw.,’ _ibidem_, Bd. 34, S. 303; ‘Absorption von Schwefelw.,’ _ibidem_, Bd. 17, S. 332; Blumenstock, ‘Lehre von der Verg. mit Kloakengasen,’ _Vierteljahrsschr. f. ger. Med._ 1873, Bd. 18, S. 295; Kasper, ‘Massenverg. mit Kloakengas,’ _Vierteljahrsschr. f. ger. Med._, Bd. 2, S. 593; Römer, ‘Akute tödl. Schwefelwasserstoffverg.,’ _Münchn. med. Wochenschr._ 1897, S. 851; Oliver, dieselbe, _Lancet_, 1903, S. 225; ‘Schwefelwasserstoffverg. bei der Saturation v. Schwefelbarium,’ _Ber. d. Berufsgen. f. Chem. Ind._ 1907, _Chem. Ind._ 1908, S. 323; ‘Schwefelwasserstoffverg. in einer Fabrik auf Ammoniaksalze’; Egli, _Unf. b. chem. Arb._, II, S. 46; ‘Schwefelwasserstoffverg. in England, Ber. d. engl. Gew.-Insp.,’ siehe _Concordia_, 1909, S. 105; ‘Schwefelwasserstoffverg. in d. chem. Ind.,’ _Techn. gewerbl. Ratgeber_ 1906, S. 108; ‘Schwefelwasserstoffverg. und Sauerstoffinhalation,’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 587; ‘Erste Hilfe bei Schwefelwasserstoffverg.,’ _Zeitschr. f. Gew.-Hyg._ 1908, S. 455, auch _Chem Ind._ 1908, S. 327. CARBON BISULPHIDE Delpech, ‘Accidents qui développent chez les ouvriers en caoutchouc et du sulfure de carbone etc.,’ _L’Union méd._ 1876, No. 66; ‘Nouvelles recherches sur l’intox. du _CS_₂ etc.,’ _Ann. d’Hyg. publ._ Nr. 37; Sapelier, ‘Étude sur le sulfure de carbone,’ Thèse, Paris 1885; Rosenblatt, _Ueber die Wirkung v. CS₂-Dämpfen auf den Menschen_, Diss. Würzburg 1890; Pichler, _Ein Beitrag z. Kenntn. d. akuten CS₂-Verg._, Berlin 1897 (Fischer); Lehmann, ‘Exp. Stud. über Schwefelk.,’ _Arch. f. Hyg._ 1894, Bd. 20, S. 56 ff.; _Zeitschr. f. Gew.-Hyg._ 1899, ‘Schutzmassregeln der Kautschukindustrie in England’; Laudenheimer, _Schwefelk.-Verg. d. Gummiarb._ 899, Leipzig, Veit & Comp.; Harmsen, ‘Die Schwefelk. im Fabr. Betrieb,’ _Vierteljahrsschr. f. ger. Med._ 1905, S. 149; Riegler, ‘Die nervösen Störungen bei CS₂-Verg.,’ _Zeitschr. f. Nervenh._ 1907, Bd. 33; Roth, ‘Gewerbl. CS₂-Verg. usw.,’ _Berl. klin. Wochenschr._ 1901, S. 570; Reiner, ‘Schwefelk.-Amblyopie,’ _Wiener klin Wochenschr._ 1895, S. 919; Quensel, ‘Geistesstörungen nach CS₂-Verg.,’ _Monatsh. f. Psych._ 1905, Bd. 16. CYANOGEN AND CYANOGEN COMPOUNDS (PRUSSIC ACID, &C.) Merzbach, ‘Chron. Zyanverg. bei einem Galvaniseur,’ _Hyg. Rundsch._ 1899, Nr. 1; Pfeiffer, ‘Zyanverg. d. Kanalgase (Abgänge v. d. Zyangewinnung),’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1904; Stritt, ‘Verg. d. Zyanverb. im Düngemittel,’ _Zeitschr. f. Hyg._ 1909, Bd. 62, S. 169; Tatham, ‘Zyanverg. beim Reinigen v. Goldspitzen,’ _Brit. Med. Journ._ 1884, S. 409; Kockel, ‘Blausäureverg. bei einem Zelluloidbrand,’ _Vierteljahrsschr. f. ger. Med._ 1903, S. 1; ‘Zyanverg. u. Sauerstoffinhal.’ (Brat), _Zeitschr. f. Gew.-Hyg._ 1906, S. 588; Lehmann, ‘Ueber die Gift. d. gasförm. Blausäure (Giftigkeitsgrenzen),’ _Berl. klin. Wochenschr._ 1903, S. 918; Blaschko, ‘Berufsdermatosen d. Arb. (Hautleiden b. Verwendung v. Zyaniden),’ _D. med. Wochenschr_, 1889, S. 915; MacKelway s. (Hautleiden), _Amer. Journ. of Medic. Science_, 1905, S. 684; Wilkes (ditto), _Lancet_, 1904, S. 1058. ARSENIURETTED HYDROGEN GAS ‘Arsenwasserstoffverg. (Verfertigen v. Kinderballons),’ _Zeitschr. f. Gew.-Hyg._ 1902, S. 441; ‘Arsenwasserstoffverg. (Ausleeren eines Schwefelsäuretanks),’ _Gewerbl. techn. Ratgeber_ 1906, S. 109; ‘Arsenwasserstoffverg. im Hüttenbetriebe (_O_-Inhalation),’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 589 u. S. 617; ‘Arsenwasserstoffverg.,’ _Zeitschr. f. Gew.-Hyg._ 1908, S. 263, u. 1910, S. 179; ‘Arsenwasserstoffverg. in England, nach den Ber. d. engl. Gew.-Insp.,’ _Concordia 1909_, S. 105; Egli, ‘Arsenwasserstoffverg.,’ _Unf. b. chem. Arb._, II, S. 42; Lunge, ‘Arsenwasserstoffverg. beim Löten,’ _Chem.-Ztg._ 1904, S. 1169; Barié, ‘Arsenwasserstoffverg. durch Ballongas,’ _Arch. f. krim. Anthrop._ 1906, S. 147. CARBONIC OXIDE _General Literature on CO-Poisoning._—Becker, ‘Die _CO_-Verg. u. ihre Verhütung,’ _Vierteljahrsschr. f. ger. Med._ 1893, S. 349; Greiff, ‘_CO_-Verg. bei d. Teerdestill., _Vierteljahrsschr. f. ger._ Med. 1890, S. 359; Brouardel, ‘_CO_-Verg. d. Kalkofengase,’ _Ann. d’Hyg. publ._ 1840; Becker, ‘Nachkrankheiten d. _CO_-Verg.,’ _D. med. Wochenschr._ 1893, S. 571; Reinhold, ‘Chron. _CO_-Verg.,’ _Münchn. med. Wochenschr._ 1904, S. 793; ‘_CO_-Verg. beim Sengen des Garnes,’ _Zeitschr. f. Gew.-Hyg._ 1909, S. 267. _Literature on CO-Poisoning in Gas Works._—Jehle, ‘Hyg. d. Gasarbeiter,’ _Zeitschr. f. Gew.-Hyg._ 1901, Heft 14 u. 15, S. 245 ff.; Schütte, ‘Krankh. d. Gasarb.,’ Weyls _Arbeiterkrankh._ 1908, S. 239 ff.; Rambousek, _Concordia 1910_, Nr. 6. CARBON OXYCHLORIDE (PHOSGENE GAS) ‘Tödl. Verg. d. Phosgen in einer Farbenfabrik,’ _Jahresber. d. Berufsgen. f. d. Chem. Ind._ 1905, vgl. _Gewerbl. techn. Ratgeber_, 1906, S. 108; Klocke, ‘Mehrere gewerbl. Phosgenverg.,’ _Zeitschr. f. Gew.-Hyg._ 1906; Sury-Bienz, ‘B. z. Kasuistik d. Intox.,’ _Vierteljahrsschr. f. ger. Med._ 1907, S. 251; Müller, _Zeitschr. f. angew Chemie_, Bd. 13 (Heft v. 12. Aug. 1910). CARBON DIOXIDE ‘Kohlensäureverg. b. d. Kesselreinigung,’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 129; Kohlensäureverg. und _O_-Inhalation,’ ebenda 1906, S. 589; Lehmann, ‘Unters. über die langdauernde Wirkung mittlerer Kohlensäuremengen auf den Menschen,’ _Arch. f. Hyg._ 1900, S. 335. PETROLEUM, BENZINE, &C. _Petroleumvergiftung._—Borthenson, ‘Die Naphthaind. in sanit. Beziehung,’ Vortrag auf dem XII. Intern. Aerztekongr. in Moskau 1897 u. _D. Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1898, Bd. 30, S. 315; Burenin, ‘Die Naphtha u. i. Verarb. in sanit. Beziehung, Petersburg 1888; Lewin, ‘Ueber allg. und Hautverg. d. Petrol.,’ _Virchows Arch._ 1888, Bd. 112, S. 35; Sharp, ‘The Poison Effects of Petrol.,’ _Med. News_, 1888; Samuel, ‘Verg. in Petroleumtanks,’ _Berl. klin. Wochenschr._, 1904, Bd. 41, S. 1047; Foulerton, ditto, _Lancet_ 1886, S. 149; Mabille, ditto, _Revue d’Hyg._ Bd. 18, 1896, Nr. 3; _Ber. d. engl. Gew.-Insp._; vgl. _Concordia_ 1909, S. 105. _Skin diseases in Petroleum und Paraffinarbeiter._—Chevallier, _Ann. d’Hyg._ 1864; Lewin, _Virchows Arch._ 1888 (siehe oben); Mitchell, _Med. News_, Bd. 53, S. 152; Derville u. Guermonprez (Papillome), _Annal. derm._ 1890, S. 369; Brémont, _Revue d’Hyg._ 1895, S. 166; Rambousek, _Concordia_ 1910, Nr. 6. _Benzinvergiftung._—Dorendorf (b. Kautschukarb.), _Zeitschr. f. klin. Med._ 1901, S. 42; Finlayson, _Brit. Med. Journ._ 1903, S. 546; Bürgi (Verg. d. Autobenzin), _Korr. f. Schweiz. Aerzte_, 1906, Bd. 36, S. 350; Box, _Brit. Med. Journ._ 1908, S. 807; _Zeitschr. f. Gew.-Hyg._ 1908, S. 333, 1907, S. 157, und 1906, S. 515; Schäfer, ‘Verwendung u. schädl. Wirkung einiger Kohlenwasserstoffe u. anderer Kohlenstoffverbindungen,’ _Hamb. Gew.-Insp.-Arb. u. Sonderberichte_, 1909, S. 7. BENZENE Benzolverg. b. d. Benzoldestill: _Zeitschr. f. angew. Chemie_, 1896, S. 675; _Chem. Ind._ 1906, S. 398; _Chem. Ztg._ 1910, S. 177. Benzolverg. (Benzolextrakt.-Appar.): Egli, _Unf. b. chem. Arb._ 1903, S. 58; _Chem. Ind._ 1907, S. 347; vgl. Lewin, _Münchn. med. Wochenschr._ 1907 und _Zeitschr. f. Gew.-Hyg._ 1907, S. 581. Benzolverg. b. Reinigen von Benzollagerkesseln: _Chem. Ind._ 1905, S. 444; 1907, S. 347; ferner 1909, Nr. 14, Beil. S. 25. Benzolverg. in einer Gummifabrik: _Chem. Ind._ 1905, S. 442. Benzolverg. bei d. Fabr. v. Antipyrin: Egli, _Unf. b. chem. Arb._, I, 1903, S. 58. Benzolverg. d. Asphaltanstrichmasse: _Zeitschr. f. Gew.-Hyg._ 1904, S. 292. Santesson, ‘Bensolverg. in einer Gummiw.-Fabrik. (und exper. Untersuchungen),’ _Arch. f. Hyg._ 1897, Bd. 31, S. 336. Rambousek, _Die gewerbl. Benzolverg. Bericht am II. Int. Kongr. f. Gewerbekrankh. in Brüssel_ 1910. Wojciechowski, _Ueber die Giftigkeit versch. Handelssorten des Benzols in Gasform_, Inaug.-Diss. Würzburg, 1910; Lehmann, ‘Aufnahme von Benzol aus der Luft durch Tier und Mensch,’ _Arch. f. Hyg._ 1910, Heft 4; Sury Bienz, ‘Tödliche Benzolverg.,’ _Vierteljahrsschr. f. ger. Med._ 1888, S. 138; Schaefer, ‘Verwendung u. schädl. Wirkung einiger Kohlenw. u. anderer Kohlenstoffverbindungen,’ _Hamb. Gew.-Insp., Arb. und Sonderberichte_, 1909. HALOGEN SUBSTITUTION PRODUCTS OF THE ALIPHATIC HYDROCARBONS (NARCOTICS) Lehmann, ‘Aufnahme chlorierter Kohlenwasserstoffe aus der Luft durch Mensch und Tier (Chloroform, Tetrachlorkohlenstoff, Tetrachloräthan),’ _Arch. f. Hyg._ 1910, Bd. 72, Heft 4; Grandhomme, _Die Fabr. d. A.-G. Farbwerke in Höchst a. M. in sanit. und soz. Beziehung_, 1893, 3 Aufl., S. 88 (Jodmethylverg. b. d. Antipyrinbereitung); Jacquet, ‘Gewerbl. Brom- und Jodmethylverg.,’ _D. Arch. f. klin. Med._ 1901, Bd. 71, S. 370; Schuler, ‘Gewerbl. Brommethylverg.,’ _D. Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1899, Bd. 31, S. 696; Schaefer, ‘Verwendungsart u. schädl. Wirkung einiger Kohlenwasserst. u. anderer Kohlenstoffverg.’ (Tetrachlorkohlenstoff),’ _Ber. d. Hamburger Gewerbe-Inspektion_, 1909, S. 11. HALOGEN SUBSTITUTION PRODUCTS OF THE BENZENE SERIES (CHLORBENZENE, &C.). Leymann, ‘Erkr.-Verh. in einigen chem. Betr.,’ _Concordia_ 1906, Heft 7 (Chlorbenzol, Benzoylchlorid); ‘Verg. mit Chlorbenzol, Nitrochlorbenzol usw.,’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1902, Suppl. S. 371, und _Concordia_ 1902, Nr. 5; Mohr, ‘Chlorbenzolverg.,’ _D. med. Wochenschr._ 1902, S. 73. HYDROXYL SUBSTITUTION PRODUCTS OF THE ALIPHATIC SERIES (ALCOHOLS) Pohl, ‘Wirkungen von Methylalkohol,’ _Arch. f. exp. Path._ 1893, S. 281; Patillo u. Colbourn, ‘Gewerbl. Methylalkoholverg.,’ _Ophthalm. Rec._ 1899. NITRO AND AMIDO DERIVATIVES OF BENZENE (NITROBENZENE, ANILINE, &C.) Leymann, ‘Erkr.-Verh. in einer Anilinfarbenfabrik,’ _Concordia_ 1910, Heft 17, S. 355; Grandhomme, _Die Fabr. d. A.-G. Farbw. in Höchst. a. M. in sanit. u. soz. Beziehung_, 1896 (und _Vierteljahrsschr. f. ger. Med._ 1880); ‘Nitrobenzol- und Anilinverg., Vorschr. f. d. Verhalten,’ _Zeitschr. f. Gew.-Hyg._ 1906, Nr. 22, S. 619; ‘Nitrobenzol (in Mineralöl),’ _Zeitschr. f. Gew.-Hyg._ 1910, S. 159; Röhl, ‘Akute u. chron. Verg. m. Nitrokörpern d. Benzolreihe,’ _Vierteljahrsschr. f. ger. Med._ 1890, S. 202; Letheby, ditto, _Proceed. of the Roy. Soc. London_, 1863, S. 550; Thompson, ditto, _British Med. Journ._ 1891, S. 801; Friedländer, ‘Intox. m. Benzol- u. Toluolderivaten,’ _Neurol. Zentralbl._ 1900; S. 294; ‘Nitrotoluolverg. in einer Sprengstoffabrik,’ _Zeitschr. f. Gew.-Hyg._ 1908, S. 383; ‘Nitroxylolverg.,’ _Chem. Ind._ 1905, S. 444; ‘Intox. m. Nitrokörpern. u. deren Behandl. m. Sauerstoffinhal.,’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 617; Brat, ‘Gew. Methämoglobinverg. u. deren Behandl. m. Sauerstoff,’ _D. med. Wochenschr._ 1901, S. 296; Leymann, ‘Verg. m. Nitrobenzol, Nitrophenol, Dinitrophenol, Nitrochlorbenzol, usw.,’ _Concordia_ 1902, Nr. 5; Schröder und Strassmann (Verg. in Roburitfabriken), _Vierteljahrsschr. f. ger. Med._, Suppl. 1891, S. 138; Brat, ‘Erkr. in einer Roburitfabrik,’ _D. med. Wochenschr._ 1901, Nr. 19 und Nr. 20; ‘Verg. m. Dinitrobenzol in England,’ _Concordia_ 1909, S. 105; Mohr, ‘Verg. m. Chlorbenzol, _D. med. Wochenschr._ 1902, S. 73; Silex, ‘Augenschädigungen d. Nitronaphthalin,’ _Zeitschr. f. Augenheilk._ 1902, S. 178; Häusermann und Schmidt, ‘Gewerbl. Nitrobenzol- u. Anilinverg.,’ _Vierteljahrsschr. f. ger. Med._ 1877, S. 307; ‘Gewerbl. Anilinverg.,’ _Zeitschr. f. Gew.-Hyg._ 1909, S. 350 u. S. 602, 1908, S. 384, 1906, S. 455, S. 599, S. 617 u. 619 (Behandlung), 1903, S. 133, 1902, S. 63; ‘Anilinverg. in England,’ _Concordia_ 1909, S. 105; Hildebrandt, ‘Anilinderivate, Giftwirkung (Intern. med. Kongr. Budapest 1909),’ _Chem. Ztg._ 1909, S. 997; Seyberth, ‘Blasengeschwülste d. Anilinarb.,’ _Münchn. med. Wochenschr._ 1907, S. 1573; ‘Erhebungen über das Vorkommen von Blasengeschwülsten bei Anilinarb.,’ _Zeitschr. für Gew.-Hyg._ 1910, S. 156; Rehn, ‘Blasengeschwülste bei Anilinarb.,’ _Arch. f. klin. Chir._ 1895, S. 588; Lewin, ‘Paranitranilinverg., Obergutachten,’ _Zeitschr. f. Gew.-Hyg._ 1909, S. 597; Criegern, ‘Gewerbl. Paraphenylendiaminverg.,’ XX. Kongr. f. inn. Medizin, Wiesbaden, 1902; Erdmann, Vahlen, ‘Wirkung des Paraphenylendiamins,’ _Arch. f. exp. Path._ 1905, S. 401; Georgievics (Wirkung d. Teerfarbstoffe), _Farbenchemie_, 1907, S. 13; Prosser White, Researches into the Aromatic Compounds, _Lancet_, 1901, Case of Aniline Poisoning, Intern. Cong. Brussels, 1910. TURPENTINE Lehmann, ‘Beiträge z. Kenntn. d. Terpentinölwirkung,’ _Arch. f. Hyg._ 1899, S. 321; Reinhard, ‘Gewerbl. Terpentinintox.,’ _D. med. Wochenschr._ 1887, S. 256; Drescher, ‘Terpentindampfinh. tödl. Verg. eines Arb. beim Innenanstrich eines Kessels,’ _Zeitschr. f. med. Beamte_ 1906, S. 131; Schaefer, ‘Verwendungsart u. schädl. Wirkung einiger Kohlenwasserstoffe u. and. Kohlenstoffverbind.,’ _Hamburger Gew.-Insp., Arbeiten und Sonderabdrücke_, 1909, S. 9. PYRIDENE Blaschko, ‘Möbelpoliererekzem,’ _D. med. Wochenschr._ 1890, S. 475. TOBACCO, NICOTINE Jehle, ‘Gesundh. Verhältn. d. Tabakarb.,’ _Arch. f. Unf.-Heilk._ 1901, ref. _Zeitschr. f. Gew.-Hyg._ 1901, S. 236; Rochs, ‘Einfluss d. Tabaks auf die Gesundheitsverhältnisse d. Tabakarb.,’ _Vierteljahrsschr. f. ger. Med._ 1889, S. 104. PART III PREVENTIVE MEASURES GENERAL MEASURES (NOTIFICATION, LISTS OF POISONOUS SUBSTANCES, &C.) Fischer, _Liste der gewerbl. Gifte_ (_Entwurf_), Frankfurt a. M. (als Manuskript gedruckt), 1910; Sommerfeld, _Liste der gewerbl. Gifte_ (_Entwurf_) Verlag Fischer, Jena, 1908; Carozzi, _Avvelenamenti ed infezioni professionali_ (_gewerbl. Gifte und Infektionen_), Verlag Fossati, Mailand, 1909; Rambousek, _IIᵉ Congrès int. des maladies prof. Bruxelles_ 1910, S. 14; ‘Anzeigepflicht bei gewerbl. Erkrankungen,’ Ber. über die Verh. d. Abt. f. Gewerbekrankh. auf der 36. Jahresvers. der British med. Assoc. in Sheffield 1908, _Brit. Med. Journ._ 1908, S. 401-408 und 480-496; Rambousek, ‘Arbeiterschutz und Versicherung bei gewerbl. Erkrankungen,’ _Sozialtechnik_ 1909, Heft 4, S. 65; Lewin, _Grundlagen für die med. und rechtl. Beurteilung des Zustandekommens und des Verlaufes von Vergiftungs- u. Infektions-Krankheiten im Betriebe_ (Monogr.) Berlin, Heymanns Verlag, 1907. SULPHURIC ACID INDUSTRY ‘Schwefelsäureerzeugung, Schutz gegen Nitroseverg.,’ _Gewerbl. techn. Ratgeber_, 1906, Heft 6, S. 109; ‘Schwefelsäureerzeugung, Reinigung von Tankwaggons,’ _Gewerbl. techn. Ratgeber_, 1906, Heft 6, S. 109; ‘Schwefelsäuretransport,’ _Zeitschr. f. Gew.-Hyg._ 1902, Nr. 4, S. 63; ‘Schwefelsäureverg., Verhütung,’ _Chem. Ind._ 1909, Beilage, _Ber. d. Berufsgen. f. d. chem. Ind. f. d. J._ 1908, S. 26; ‘Ausräumen des Gay-Lussac, Verhütung von Verg., _Chem. Ind._ 1907, S. 351; ‘Sauerstoff gegen Schwefelsäureverg., Atemapparate,’ _Zeitschr. f. Gew.-Hyg._ 1906, Nr. 20, S. 562, und 1906, Nr. 22, S. 617. PETROLEUM, BENZINE Berthenson, ‘Die Naphthaindustrie in sanit. Beziehung,’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1898, Bd. 30, S. 315; Korschenewski, _Wratsch_, 1887, Nr. 17; Burenin, ‘Die Naphtha und ihre Verarbeitung in sanit Beziehung,’ Petersburg 1888; Mabille, ‘Revue d’Hygiène,’ Bd. 18, Nr. 3; _Bericht der Berufsgen. f. chem. Ind._ 1905; _Bericht der preuss. Gew.-Insp._ 1904; Klocke, _Zeitschr. f. Gew.-Hyg._ 1908, S. 379; ‘Benzinersatz (in chem. Wäschereien),’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 248, und 1908, S. 384; ‘Schutz des Arbeiters vor Benzindämpfen,’ _Zeitschr. f. Gew.-Hyg._ 1906, S. 236. CARBON BISULPHIDE ‘Nachweisung von Schwefelkohlenstoffdämpfen in Fabrikräumen,’ _Zeitschr. f. Gew.-Hyg._ 1908, Nr. 5, S. 107; ‘Hygienische Einrichtung beim Vulkanisieren (Glibert),’ _Zeitschr. f. Gew.-Hyg._ 1902, Nr. 1, S. 1; ‘Absaugung der Dämpfe an Vulkanisiertischen,’ _Zeitschr. f. Gew.-Hyg._ 1903, Nr. 14, S. 305; Laudenheimer, ‘Die Schwefelkohlenstoffverg. bei Gummiarbeitern,’ Leipzig, Veit & Comp., 1899; Roeseler,’Schwefelkohlenstofferkrankungen und deren Verhütung,’ _Vierteljahrsschr. f. Med. u. öffentl. Sanitätswesen_ 1900, 3. Folge, Bd. 20, S. 293 (ref. _Zeitschr. f. Gew.-Hyg._ 1901, S. 164); ‘Einrichtungen von Gummifabriken,’ _Zeitschr. f. Gew.-Hyg._ 1903, S. 260 u. 484. ILLUMINATING GAS ‘Leuchtgasverg.-Verhütung,’ _Zeitschr. f. Gew.-Hyg._ 1909, Heft 22, S. 604; ‘Kokslöscheinrichtung,’ _Zeitschr. f. Gew.-Hyg._ 1908, Heft 10, S. 231; ‘Bedeutung der Sauerstoffinhalationen in der Leuchtgasindustrie,’ _Zeitschr. f. Gew.-Hyg._ 1906, Heft 21, S. 590; ‘Entleerung der Reinigungskästen in der Leuchtgasfabrik, _Zeitschr. f. Gew.-Hyg._ 1903, Nr. 13, S. 283; Jehle, ‘Hygiene der Gasarbeiter,’ _Zeitschr. f. Gew.-Hyg._ 1901, Nr. 14, S. 245. COAL TAR COLOURS (ANILINE FACTORIES) Grandhomme, _Die Fabriken der A.-G. Farbwerke vorm. Meister, Lucius & Brüning zu Höchst a. M._, Frankfurt a. M. 1896; Leymann, ‘Ueber die Erkrankungsverhältnisse in einer Anilinfabrik,’ _Concordia_ 1910, Heft 17, S. 355 ff.; Leymann, _Die Verunreinigung der Luft durch gewerbliche Betriebe_ (Fischer, Jena, 1903); ‘Sauerstoffinhalationen in Anilinfabriken,’ _Zeitschr. f. Gew.-Hyg._ 1906, Nr. 22, S. 617, und 1908, S. 327. LEAD (GENERAL) Legge & Goadby, ‘Lead Poisoning and Lead Absorption,’ 1912; _Bleiverg. in gewerbl. u. hüttenmänn. Betrieben Oesterreichs_, herausgeg. vom. k. k. Arbeitsstatist. Amte, I-VI, Verlag Hölder, 1905-1909; Leymann, _Die Bekämpfung der Bleigefahr in der Ind._, Verlag Fischer, Jena, 1908; Wächter, _Die gewerbl. Bleiverg. im Deutschen Reiche_, Verlag Braun, Karlsruhe 1908; Blum, ‘Untersuch, über Bleiverg., Frankfurt a. M. 1900,’ _Wiener klin. Wochenschr._ 1904, S. 1935; Rambousek, _Ueber die Verhütung der Bleigefahr, Wien_, Hartleben, 1908; Teleky, ‘Die gewerbl. Bleiverg. in Oesterr.,’ _Sozialtechnik_ 1909, S. 333, _Wiener klin. Wochenschr._ 1907, S. 1500. LEAD SMELTING _Bleiverg. in gewerbl. u. hüttenmänn. Betrieben Oesterr._, I und III, Verlag Hölder, Wien; Müller, _Die Bekämpfung der Bleigefahr in Bleihütten_, Verlag Fischer, Jena, 1908; Wutzdorff, _Bleiverg. in Zinkhütten_, Arb. a. d. Kaiserl. Ges.-Amte, Bd. 17, S. 441; Elsässer, ‘Schädl. in Blei- und Silberhütten,’ _Vierteljahrsschr. f. ger. Med._ 1903, Bd. 25, S. 136. PAINTS AND COLOUR FACTORIES Über Hygiene der Erzeugung und Verwendung von Bleifarben: _Bleiverg. in gewerbl. u. hüttenm. Betrieben Oesterreichs_, IV., V. und VI. Teil, _Hölder Wien_; Stüler, ‘Bleiverg. bei Malern’; _Vierteljahrsschr. f. öffentl. Ges.-Pfl._ 1895, S. 661; ‘Bleiweissfabriken (Staubabsaugung),’ _Zeitschr. f. Gew.-Hyg._ 1909, Nr. 22, S. 601; ‘Kampf gegen die Bleifarben in Frankreich,’ _Zeitschr. f. Gew.-Hyg._ 1909, Nr. 23, S. 543; ‘Gefahren in Bleiweissfabriken,’ _Zeitschr. f. Gew.-Hyg._ 1907, Nr. 9, S. 205; ‘Bleiweissersatz (Ausstellung),’ _Zeitschr. f. Gew.-Hyg._ 1907, Nr. 11, S. 254; ’ Bleifarbenverbot,’ _Zeitschr. f. Gew.-Hyg._ 1904, Nr. 10, S. 221; ‘Bleigefahr im Gewerbe der Anstreicher, Maler usw.,’ _Soz. Technik._ 1909, Nr. 17, S. 333; ‘Bleiweissfrage,’ _Sozialtechn._ 1908, Nr. 16, S. 310. ELECTRIC ACCUMULATOR FACTORIES Wutzdorff, _Bleiverg. in Akkumul.-Fabr._, Arb. a. d. Kaiserl. Ges.-Amt 1908, Bd. 15, S. 154; ‘Hygiene der Akkumulatorräume,’ _Zeitschr. f. Gew.-Hyg._ 1909, Heft 3, S. 79, und Heft 21, S. 494; Chyzer, ‘Hygiene der Akkumulatorräume,’ _Zeitschr. f. Gew.-Hyg._ 1907, Nr. 20, S. 476; ‘Bekämpfung von Verg. in Akkumulatorräumen,’ _Concordia_ 1908, Heft 13, S. 273. LETTERPRESS PRINTING _Bleiverg. in gewerbl. u. hüttenm. Betrieb. Oesterr._, k. k. Arbeitsstat. Amt, VII. Teil, Wien, Hölder 1909; Panwitz, _Bleiverg. in Buchdruckereien_, Veröff. d. Kais. Ges.-Amtes, Bd. 17, S. 503; ‘Bleiverg. in der Buchdruckerei (Enquete),’ _Zeitschr. f. Gew.-Hyg._ 1909, Heft 6, S. 152 ff.; ‘Bleifreie Druckfarben und Bronzen (Preisausschriebung),’ _Zeitschr. f. Gew.-Hyg._ 1909, Heft 23, S. 630 ff.; ‘Setzkasten mit doppeltem Boden,’ _Zeitschr. f. Gew.-Hyg._ 1908, Nr. 10, S. 237; ‘Bleinachweis in den Dämpfen der Typengiesserei,’ _Zeitschr. f. Gew.-Hyg._ 1906, Nr. 24, S. 677; ‘Schriftsetzerei (Typenbläserei),’ _Zeitschr. f. Gew.-Hyg._ 1904, Nr. 8, S. 176; ‘Bleigefahr in Druckereien,’ _Concordia_ 1908, Heft 18, S. 384. FILECUTTING ‘Bleiverg. bei Feilenhauern in England,’ _Zeitschr. d. Zentralst. f. Arb.-Wohlf.-Einr._ 1901, S. 232; ‘Bleierkr. b. Feilenhauern,’ _Gewerbl. techn. Ratgeber_ 1905, Heft 3, S. 50; ‘Hygiene d. Feilenhauerei (Chyzer),’ _Zeitschr. f. Gew.-Hyg._ 1908, N. 13, S. 303. ZINC SMELTING Frey, _Die Zinkgewinnung im oberschles. Industriebezirk und ihre Hygiene_, Berlin 1907, Verlag Hirschwald; Sigel, ‘Das Giesserfieber und seine Bekämpfung,’ _Vierteljahrsschr. f. ger. Med._ 1906, Bd. 32, S. 173; ‘Lehmann, Beiträge zur hyg. Bedeutung des Zinks,’ _Arch. f. Hyg._ 1897, Bd. 28, S. 300; ‘Giess- oder Zinkfieber,’ _Arch. f. Hyg._ 1910, Bd. 72, S. 328; ‘Hyg. der Zinkerei,’ _Zeitschr. f. Gew.-Hyg._ 1907, Nr. 2, S. 39; ‘Zinkhütten, hyg. Einricht.,’ _Zeitschr. f. Gew.-Hyg._ 1901, Nr. 18, S. 321, und 1910, Heft 11, S. 250; ‘Giesserfieber, Bekämpfung,’ _Soz. Techn._ 1907, Heft 3, S. 51; ‘Giesserei, Hyg.,’ _Zeitschr. f. Gew.-Hyg._ 1903, Heft 16, S. 351, Heft 21, S. 479, und 1904, Heft 13, S. 344, ‘Schutz gegen Säuredämpfe bei der Metallbearbeitung,’ _Zeitschr. f. Gew.-Hyg._ 1904, Heft 1, S. 5 u. 11, ferner Heft 14, S. 317, u. 1905, Heft 10, S. 287, Heft 22, S. 643. MERCURY Quecksilberhütten in Idria: Laureck in Weyls _Handb. d. Arb.-Krankh._ 1909, S. 62; ‘Quecksilberhütten in Amiata’: Giglioli, _Ramazzini_ 1909, Bd. 3, S. 230. Quecksilberbelegerei, Hyg: Schönlanck, _Fürther Spiegelbelegen_ (Monogr.) 1888; Wollner, ‘Fürther Spiegelbelegen,’ _Vierteljahrsschr. f. öffentl. Ges.-Pfl._ XXIX 3, S. 421, und _München. med. Wochenschr._ 1892, Bd. 39, S. 533; Charpentier, ‘Fürther Spiegelbelegen,’ _Ann. d’Hyg. publ._ 1885, S. 323. Quecksilber in Hutfabriken, Quecksilberbeize: Stickler, _Revue d’Hygiène_ 1886, S. 632; Henke (Monogr.), Frankfurt a. M. 1899; Hasenfellbeize (Ersatz), _Jahresber. d. Fabr.-Insp._ 1884, S. 489, _Zeitschr. f. Gew.-Hyg._ 1902, S. 360, 1909, S. 281, _Soz. Techn._ 1910, S. 39; Hutfabriken in Italien (Hyg.), _Ramazzini_ 1909, S. 230. Sonstige Gewerbe: Glühlampenind. (Hyg.): Donath, _Wiener med. Wochenschr._ 1894, S. 888, _A. Mitt. a. d. Ber. d. Gew.-Insp._ 1899, _Zeitschr. f. Gew.-Hyg._ 1902, Heft 20, S. 356, und 1908, Heft 20, S. 469, Thermometererzeug. (Hyg.), _Zeitschr. f. Gew.-Hyg._ 1901, S. 32. ARSENIC ‘Arsenikbestimmung im Hüttenrauch’ (Harkins & Swein), _Journ. Amer. Chem. Soz._ 1907, Bd. 29, S. 970; _Chem. Ztg._, Rep. 1907, S. 447; ‘Arsenikverg. in der Ind.’ (Heim, Herbert), _Zeitschr. f. Gew.-Hyg._ 1907, Bd. 14, S. 354; ‘Arsenverg. in der Delainage,’ _Zeitschr. f. Gew.-Hyg._ 1906, Nr. 3, S. 71; ‘Gewerbl. Arsenverg.’ (Legge), _Zeitschr. f. Gew.-Hyg._ 1903, Heft 21, S. 476; ‘Arsenwasserstoffverg. im Gewerbe (Prophyl.),’ _Zeitschr. f. Gew.-Hyg._ 1908, Nr. 10, S. 229; ‘Arsenwasserstoff im Ballongas (Beseitigung),’ _Zeitschr. f. Gew.-Hyg._ 1908, Nr. 11, S. 263; ‘Arsenwasserstoff beim Ausleeren von Schwefelsäuretanks (Verhütung),’ _Gewerbl. techn. Ratgeber_ 1906, Heft 6, S. 109; ‘Arsenfreier Wasserstoff zum Löten,’ _Gewerbl. techn. Ratgeber_ 1906, Heft 10, S. 173; und _Zeitschr. f. Gew.-Hyg._ 1905, Heft 9, S. 252; ‘Befreiung der Salzsäure vom Arsengehalt,’ _Zeitschr. f. Gew.-Hyg._ 1903, Heft 21, S. 477. INDEX Heavy type (Transcriber’s Note: =like this=) refers to the main treatment of the subject and the Roman figures in brackets following to the Part of the book: (i) Occurrence of Poisoning; (ii) Pathology; (iii) Preventive Measures. Absorption towers, 256, 258, 289 Accumulator manufacture, =135= (i), 145, 295, =305-9= (iii) Acetic acid, 9, 46, 333 Acetylene, 52, =85-87= (i), =278= (iii), 279 Acrolein vapour, 326 Aerograph, 138 Akremnin soap, 294 Alcohol, 99, 100, 210, 216, 333 Alcoholism, 241 Aliphatic series. See Hydrocarbons Alizarin, 111, 113 colours, 3, 10, 57, 96, 111, 112, 114 Alkaline bromides, 36 hydroxides, 176 Alkaloids, 216 Alternation of employment, =227= (iii), 293, 299 Amalgam. See Mercury amalgam Amido compounds, 110, 112, 201, 211, =212= (ii), 287 Amines, 33, 107, 111 Ammonia, 44, 68, 71, 72, 76-79, 82, =90-93= (i), 94, =175= (ii), =279= (iii), 280 Ammonia soda process, 14, =20= (i), 92, 258 Ammonium carbonate, 44, 91, 92 compounds, 67, =90= (i), 92, =174= (ii), =279= (iii) nitrate, 44, 115 oxalate, 115 phosphate, 50, 92 superphosphate, 55 Amyl alcohol, 45, 210 nitrite, 45, 46, 212 Aniline, 3, 57, 69, 70, 96, 105, 109, 111, 112, 114, =116-119= (i), 145, 156, =212-214= (ii), =286-288= (iii) Aniline black, 117, 156 colours, 3, 4, 57, 112, 115, 117, 118, 156, 214, =285-288= (iii) oil, 117, 214 poisoning, 3, 69, 113, =116-119= (i), =212-214= (ii), =256-288= (iii) Animal products, 154 Anthracene, 3, 60, 96-97, 101, 107, 108, 111, 113, 285 Anthraquinone, 55, 111 Antimony, 122, 124, =146= (i) chloride and oxide, 37 Antipyrin, 3, 4, 36, 102, 104, 114 Argyria, =45=, 152, 188, 329. See also Silver Aromatic series. See Hydrocarbons Arsenic, 12, 65, 119, 122, =143-146= (i), 154, 189, =159= (ii), 257, 323, =328-329= (iii) Arseniuretted hydrogen gas, 12-14, 32, 113, 114, =145-146= (i), 148, 149, 188, 189, =197= (ii), 257, 279, 286, 316, =328-329= (iii) Artificial manure, 38, =53= (i), 54, 55, 92, =176= (ii), =261-265= (iii) Artificial respiration, 164, =284= (iii) Asphalt, =98= (i), 285 Aspirin, 102 Azo-colours, 96, 110, 214 Balloon filling, 145, 329 Barium chloride, 16, 66 nitrate, 44 Barometers, manufacture of, 141, 142, 328 Baryta, 66, 67, 135 Basic slag, 49, 53, =54= (i), 148, =261-264= (iii) Basophil granules, 178 Baths, 237, 292 Beer brewing, 65, 154, 333 Benzalchloride, 35, 110, 287 Benzaldehyde, 35, 109 Benzene (Benzene poisoning), 3, 4, 69, 77-79, 85, 96, =99-100= (i), 101, 102-106, 112-114, =204-208= (ii), =285-286= (iii), 288, 330 Benzidine, 118 Benzine, 34, 53, 54, =59= (i), =61=, 62, 63, 64, 68, 69, 85, 96, 156, 203, =204= (ii), =267= (iii), 268, 330 Benzol. See Benzene Benzo-trichloride, 35, 109, 287 Benzoyl chloride, 35, 209 Benzyl chloride, 35 Bessemer process, 148 Beth filter, 254 Bichromate, 50, 54, 55. See Chromates Bladder, cancer of, 114, 117, 214 Blast furnace, =146= (i), =289= (iii) gas, 65, 82, 88, =89= (i), 146, =289-290= (iii) Blasting gelatine, 47 Bleaching, 156, 337 powder, =26= (i), =259= (iii) Blood poisons, 158, 164, 199-201, 211-214 Bone extraction, 68, 69, 267 Boracic acid, 138 Bottle capsules, 323 Brass (brass-casters’ ague), =152= (i), =182= (ii), 188, =325= (iii) Breathing apparatus, =231-237= (iii), 267, 286, 288, 290, 310 Briquettes, 96, 101 Bromine, =29= (i), 36, 52, =173= (ii) Bronze, 45, 139, 316 Brunswick green, 144 Butyl alcohol, 210 Butyric acid, 75 Calamine, 125 Calcium carbide, 52, =85= (i), 87, 90, 278 sulphide (soda waste), 18 Calomel, =143= Camphor, 49 Cancer, 64, 102, 114, 118, 203, 214 Carbon bisulphide, poisoning by, 30, 31, 34, 50, 65, =68= (i), 68-71, 74, 80, 93, 96, 104, 156, 192, =193-195= (ii), =271-275= (iii) oxychloride, =32= (i), 33, =294= (iii) tetrachloride, =34= (i), 69, 208, 268, 275 Carbonic acid gas (carbon dioxide), =17=, 50, 53, 54, 68, 74, 82, 131, 149, 153, =201-202= (ii), 330, 332 oxide, 17, 21, 31, 32, 50, 74-76, 80, 82, =87-90= (i), 102, 107, 119, 148, 149, 153, 154, 156, 188, =199-200= (ii), 288, 289, 323, 330, 332 Carbonising, 156, 336 Carborundum. See Silicon carbide Carburetted gas, 61, 83, 87 Caustic alkali, 25 potash, 3, 25, 34, 176 soda, 18, 19, 25, 36, 157, 176 Celluloid, 48, 49 Cellulose, 156, 336 Chamber acid, 5, 8, 53, 258 Chance-Claus process, 19 Chemical cleaning. See Benzine industry, =1= (i), 134, 145, =256= (iii) Chili saltpetre, 35, 39, 41, 45, 54 Chloral, 34 Chlorates, =23= (i), 25, 26, 29, 30, 52 Chloride of lime. See Bleaching powder sulphur, 31, 32, 68, 70, 174, 272-274 Chlorides, =30= (i), =174= (ii) Chlorine, =23= (i), 25, 26, 27, 30-32, 34, 35, 39, 44, 52, 58, 156, =173= (ii), 209, =259= (iii), 285 rash, 28, 35, 173, 174, 209, 259 Chlorine compounds, organic, 27, 69, 209, 285 Chloroform, 26, 33, 34, 208 Chrome colours, 55, 56, 265 poisoning, 52, =56= (i), 57, 58, 114, 153, =185= (ii), =265= (iii) tanning, =55= (i), 57, 58, =266= (iii) yellow, 44, 55, 57 Chromium (chromates), 3, 52, =55= (i)-58, 114, 134, 153, =185= (ii), =265= (iii), 271 Coal tar. See Tar Cobalt, =144= Coke ovens, =77= (i), 78, 79, 92, 102, 104, =276= (iii) Compositors. See Printing Condensation, =255= (iii), 323, 327 of mercury, 141 zinc, 125 Copper, =151= (i), =188= (ii) Cresols, 96, 101, 109 Cumene, 207 Cyanogen, 77, =93= (i), 152, =195= (ii), 261, 279, =280= (iii) compounds, 71, 79, 92, =93= (i), 94, 95, 103, 152, 154, =195= (ii), 196, 262, 279, =280= (iii), 289 Deacon process, 23, 28 Denitration, 6, 43, 47, 48, 287 Desilverising, 124, 126, 128 Diaphragm method (chlorine), 24 Diazo-compounds, 110, 286 Diethyl sulphate, 23 Digestive tract, diseases of, 76, 129, 130, 133, 179, 182, 186 Dimethyl aniline, 109 Dinitrobenzene, 35, 108, 112, 115, 116, 212 Dinitrochlorobenzene, 115, 209, 212 Dinitrophenol, 115, 212, 213 Dinitrotoluol, 108, 212 Distillation, 253, 255 of alcohol, 333 petroleum. See Petroleum distillation tar. See Tar distillation Dowson gas, 82, 83, 87, 276 Dräger’s oxygen apparatus, 165-167 Dry cleaning. See Benzine Dust removal, =243-256= (iii). See also Ventilation Dye stuffs, =107-119= (i), =214= (ii), =285-288= (iii), 337 Dyeing and colouring, 44, 45, 55, 57, 92, 134, 144, 156, 265, 310-316, 337 Dynamite, 43, 47 Earthenware. See Pottery Eczema, 64, 186 Electric furnace, 85 Electroplating, 196, 327, 329 Enamel, 135, 322 Encephalopathy, 181 Etching on glass and metal, 37, 40, 45, 57 Ether, 68, 69 Ethyl alcohol, 34, 210 chloride, 34 Explosives, =45= (i), 49, 115, =260= (iii) Extraction, 54, 61, =68= (i), 68-69, 71, 100, 103, 117, 186, =253= (iii), 267, 272-274 Eye affections, 21, 23, 38, 55, 57, 65, 68, 70, 75, 93, 115, 116, 119, 171, 174, 175, 210 Fans, =244-247= (iii). See also Ventilation Fat extraction, 34, 61, 68, 70, 71, 272-274 Fermentation, 154, 333 Ferrosilicon, 53, 85, 146, =149-151= (i), 199, =291= (iii) File cutting, =140= (i), 294, =322-323= (iii) Fluorine. See Hydrofluoric acid Fluorine compounds, 37, 54, 153, 171, 265 Flux, 135, 149 Frit, 135, 136, 137, 138, 320 Fuchsin, 111, 113, 119, 144, 287 Fulminate of mercury, =46= (i), 143, 261 Galvanising, 94, 95, 152, 326, 329 Gas engines, 82, 88, 89, 100, =276-278= (iii) lighting, =71-89= (i), 92, 93, 175, =275= (iii) lime, 65, 94, 153, 275 purifying material, 5, 65, 68, 74, 75, =93= (i), =275= (iii), 276 Gay-Lussac tower, 5, 6, 10, 11, 256, 257, 287 Generator gas. See Producer gas Glass etching, 37, 38, 153, 330 industry, 19, 37, 39, 55, 58, 82, 88, 138, 143, =153= (i), 322 pearl silvering, 152 Glazing, =135-138= (i), =319-322= (iii) Glover acid, 6, 8 tower, 5, 6, 257, 287 Gold, 44, 94, 125, 152 Gun-cotton, 47-49 Guttapercha, 69 Hæmolysis, 158 Halogens, =31= (i), =173-174= (ii) Hargreaves process, 19, 28 Hatters’ furriers’ processes, 45, 141, 142, 154, 327 Hausmannite, 58 Health register, 227, 264, 274, 298, 304, 307 Hides and skins, preparation of, 142, 143, 144, 184, 327 Hops, sulphuring of, 154, 333 House painting, 121, 122, =132-133= (i), 294, =314-316= (iii) Hydrocarbons, 96, 106, 158, 286, 287, 330, 331 (aliphatic), 96, 202 (aromatic), 96, 108, 109, 202, 204, 330 Hydrochloric acid, =14= (i), 15, 20, 21, 23, 30-35, 39, 44, 50, 54, 59, 113, 145, 131, =170= (ii), =257-258= (iii), 286, 326 Hydrofluoric acid, =29= (i), 37, 38, 50, 54, 96, 153, =171= (ii), =265= (iii) Hypochlorite, 25, 30 Incandescent lamps, 141, 327 Indiarubber, 31, 61, 63, =68-71= (i), 100, 103, 134, 194, 267, =271-274= (iii) Indigo, 34, 92, 111 Injectors, 245 Insurance, Workmen’s, 224 International Labour Bureau, 219 Iodine, =30= (i), 36, =173= (ii) compounds and poisoning, 36 Iron, 44, 124, 144, =146-149= (i), =289-291= (iii) Kidney disease, 57, 130, 181, 185, 215 Lampblack, 97 Lead, 8, 13, 29, 44, 55, 68, 69, =120-140= (i), 144, 149, 152, 156, =177-182= (ii), 329 acetate, 55, 131, 134 burning, 140, 323 carbonate. See White lead chloride, 55, 181 chromate, 55, 57, 132, 134, 138, 310 colic, 179. See Lead poisoning colours, =131-134= (i), 293, 294, 295, =310-316= (iii) nitrate, 50, 55 oxide, 44, 45, 122, 131, 134, 135, 136, 137, 181 piping, 140, 323 poisoning, 3, 13, 44, 69, 93, 114, =120-122= (i), 146, 149-152, =177-182= (ii), =292-323= (iii) silicate, 135 smelting, =122-131= (i), =299-305= (iii) sulphate, 55, 122, 181 sulphide, 122, 131, 136, =293= (iii) Leblanc soda process, =14= (i), 18, 19 Light oils, 98 Ligroine, 61 Lime kilns, 55, 153, 330 Litharge, 124, 126, 129, 131, 132, 134, 135, 138, 300-305 Lithopone. See Zinc white Lungs, diseases of, 9, 40, 54, 68, 75, 76, 106, 118, 169-177, 189, 201, 204, 213-216 Mahogany, 156 Malt drying, 333 Manganese (manganese poisoning), 23, 29, =58= (i), 59, 153, =179-180= (ii) Meal rooms, 236 Mercaptan, 22, 96 Mercury and mercury poisoning, 40, 44, =141= (i), 152, 154, =184= (ii), =326-327= (iii), 329 amalgam, 141, 142, 327 Metals, recovery of, =120= (i), =176= (ii) =288= (iii) Metaphenylene diamine, 118 Methyl alcohol, 33, 34, 36, 37, 107, 156, 209, =210= (ii), 336 bromide and iodide, 36, 209 chloride, 33, 209 violet, 112, 119 Methylamine, 96 Methylene chloride, 34, 208 Mineral acids, =169-172= (ii) Mineral oil, =59= (i), 60-63, 64, 65, 85 Mirbane, oil of. See Nitrobenzene Mond gas, 82, 87 Mordants, 32, 55, 337 Muffle furnace, 15, 20, 22, 125, 137, 138, 143, 258, 325 Naphtha. See Petroleum vapour, 42, 63, 267 wells, 61, 62, 267 Naphthalene, 74, 96, 100, 101, 113, =208= (ii) Naphthol, 9, 96, 101, 109, 110 yellow, 110 Naphthylamine, 103, 110, 118, 287 Narcotic poisons, 208, 209 Nephritis. See Kidney disease Nerve poisons, 158, 192, 205 Nervous diseases, 70, 107, 163, 181, 184, 189, 190, 193, 194, 196, 197, 199, 202, 204, 205, 215 Nickel, 144, =186= (ii) carbonyl, =186-188= (ii) eczema, 186 Nicotine, 216 Nitrating, 41-43, 47, 49, =108= (i), =261= (iii), 286 Nitric acid, 2, 6, 9, 10, =39= (i), 43-49, 107, 116, 182, =172= (ii), =260= (iii), 261, 285-287, 326 Nitrobenzene, 3, 9, 35, 40, 41, 45, =108-115= (i), =212= (ii), =285-288= (iii) Nitro-cellulose, 40, 42, 47, 48, 336 Nitrochlorobenzene, 116, 209 Nitro-compounds, 40, =108= (i), 109-112, 114, 115, =211-214= (ii), =286-288= (iii) Nitro-glycerin, 9, 40, 41, 43, =46= (i), 47, 48, =212= (ii), =261= (iii) Nitronaphthalin, 115, 116, 214 Nitrophenol, 3, 46, 115, 212, 288 Nitrous fumes, 10, 12, =40-44= (i), 48, 116, 171, =261= (iii), 286, 326 Notification of poisoning, =220-225= (iii) Oil, extraction, 61, 68, 69, 267 Organ pipe making, 140 Oxalic acid, 55, 259 Oxygen inhalation, 43, 63, 64, =164-168= (ii), 188, 192, 196, 200-202, 204, 208, 227, =231-237= (iii) Painting. See House painting Paints (quick-drying), =330-332= Paper, manufacture of, 336 Paraffin, 50, 59, 60, 96, 98, 101, 107, 203 eczema, 27, 64, 65, 102, 203 Paranitraniline, 114, 118, 214 Paraphenylene diamine, 118, 214 Parkes’ process, 125, 127 Pattinson process, 125, 127 Petrol ether, 60, 331 Petroleum (petroleum poisoning), =59-65= (i), =202-204= (ii), =267= (iii) Phenanthrene, 96 Phenol, 75, 90, 96-100, 108, 109 Phenylhydrazine, 36 Phosgene. See Carbon oxychloride Phosphor bronze, 52 Phosphoretted hydrogen gas, 50, =52= (i), 86, 90, 149, =191-192= (i) Phosphorus, 31, 36, =49= (i), 50, 52, 148, 149, =190-191= (ii), =268-271= (iii) necrosis, =51= (i) 52, =190-191= (ii), =268-271= (iii) prohibition of, 51, 220, =268-271= (iii) Photography, 36, 45, 58, 94, 152 Picric acid, 40, 96, 100, 108, 115, 116, =213= (ii) Pitch, 96, 97, 107, 281, 282 Plate towers, 7, 16, 39 Poisons, classification of, =157-163=, =169= (ii) Porcelain, =138= (i), 322 Potassium bichromate. See Chromium chlorate, 26, 29, 37, 50, 52 Pottery, =135-138= (i), 153, 294, =319-321= Power gas, =80-90= (i), =277= (iii) Printing, =138-139= (i), 146, =317-319= (iii) Producer gas, 80-82, 87-89, 153, 276-278 Propyl alcohol, 248, 249 Prussic acid. See Hydrocyanic acid Pulmotor, 167, 168 Pyridine, 59, 90, 96, 101, 152, =216= (ii), 285 Pyrites burner, 5, 6, 65, 256 Pyroxyline, 48, 261 Quick-drying paints, =330-332= Quicklime, 54, 73 Quinoline bases, 110 Realgar. See Arsenic Refrigeration, 92, 93, 154 Regenerator firing, 81, 148, 153 Rescue appliances, =164-168= (ii), =230-235= (iii) Respirators, =229= (iii) Roasting (calcining furnaces, &c.), 5, 11, 65, 119, 120, 125-127, 129, 130, 131, 141, 143, 253, =288-289= (iii), 299, 323, 327 Roburite, 115, 116 Roofing felt, 96, 101, 281 Rubber. See Indiarubber Salt, 32, 33 Saltcake. See Sodium sulphide Saltpetre, 35, 42, 50, 257 Satinwood, 154, 155 Sewer gas, 66, 67, 93, 95 Shot, 121, 140, 143 Silicon carbide, 85, 140, 323 Silicofluoric acid, 38, 50, 54, 171 Silk, artificial, 49 Silver (argyria), 45, 92, =120= (i), 122-125, 144, 152 nitrate, 40, 45, 142, 188, 227 smelting, =122=, =131= (i) Skin diseases, 27, 38, 47, 52, 55, 56, 58, 62, 64, 65, 71, 96, 102, 107, 118, 143, 144, 154-156, 171, 173, 185-189, 203, 208, 209, 265 Smelting processes, 89, 94, =119= (i), 143, 144, 182, =288-290= (iii), 299, 323-325, 326 Smokeless powder, 49, 211 Soda, 2, =14= (i), 17-20, 55, 65, 92, 95, =258= (iii) electrolytic, 20 waste, 18, 65, 258 Sodium bichromate. See Chromate sulphate and sulphide, =14= (i), 17, 19-22, 22, 112, =258= (iii), 286 Soldering, 145, 316, 329 Solvay method. See Ammonia soda Solvent naphtha, 99-102, 106, =207= (ii), 330 Spirit, denaturing of, 99, 100, 210, 216 Substitutes for poisonous materials, =243= (iii) Suction gas, =82= (i), 83, 87-89, =276-278= (iii) Sulpho-cyanide compounds, 75, 90, 93 Sulphonal, 22, =259= (iii) Sulphur, 31, 52, =65= (i), 65, 68, 74, 93, 122, 288 Sulphur dioxide, =5= (i), 9, 13, 14, 19, 21, 23, 31, 54, 63, 65, 119, 120, 122-125, 148, 154, =171= (ii), =257= (iii), 259, 267, 279, 288, 323, 326, 327, 333 dyes, 112 soap, 294 Sulphuretted hydrogen, 8, 12, 13, 16, 18, 21, 50, 52-54, =65= (i), 66, 67, 74, 79, 90-93, 95, 96, 101, 102, 103, 106, 107, 112, 114, 175, =192= (ii), 193, 258, 271, 279, 280, 285, 286, 290 Sulphuric acid, =5= (i), 9, 14, 18-20, 23, 33, 37-41, 46, 47, 49, 50, 53, 54, 60, 64, 65, 67, 92, 93, 108, 112, 119, 145, 151, 154, 156, =171= (ii), =256-257= (iii), 261, 279, 286 arsenic free, 9 Superphosphate industry, 38, =53= (i), 54, 55, 92, =176= (ii), =261-265= (iii) Swedish matches, 50, 52, 55, 58, 265 Tanning, 55, 56, 58, 66, 67, 94, 143, 144, 153, 265, 329 Tar, 71, 77-80, =96-107= (i), 156, 275, =280-285= (iii) colours. See Aniline colours derivatives, 40, 46, =96-107= (i), =204-208= (ii), 210, =213-215= (iii) Teak wood, 154 Textile industry, 134, =156= (i), =336= (iii) Thermometers, manufacture of, 141, 328 Tiles, =137-138= (i). See also Pottery Tin, 44, 138 Tobacco industry, =154= (i), =335= (iii) Toluene, 32, 35, 96, 108, 112, 204, =206= (ii), 285 Toluidine, 109, 111, 118, 214, 285, 287 Treatment of poisoning, =163-127= (ii) Turpentine, 69, 104, =215= (ii), 331 Type casting, 138, 139 Ultramarine, 19, 22, 259 Ursol, 118 Varnish, 58, 61, 101, 215, 330-332, 337 Vaseline, 60 Vegetable food stuffs, preparation of, =154= (i), =332-336= (iii) Ventilation, =243-255= (iii) artificial, 244-247 localised, 248-250 natural, 243 Vermilion, 57 Vulcanising, 31, =68= (i), 68-70, =272-274= (iii) Washing accommodation, =237= (iii) Waste sulphuric acid, 43, 53 water, 66 Water gas, 82, 84, 87, 88 gilding, 141, 142, 327 Weldon process, 23, 29, 58, 59 White lead, 55, =131-134= (i), =310-313= (iii) Wood (poisonous), =154-156= (i), =216= (ii), =335= (iii) Workmen’s baths, 237, 292 clothing, 229 insurance, 219 welfare, 237-242 Xylene, 32, 99, 100, 107, 204, 206 Zinc, =120= (i), 121, =122-131= (i), 139, 144, 151, =182-183= (ii), =294=, 299-305, =323-325= (iii) ashes, 125 oxide, 32, 38, 125, 145, 182 poisoning, =182-183= (i), =325= (iii) smelting, 122-125, =125-131= (i), =323-325= (iii) white, 68, 293 THE END PRINTED BY SPOTTISWOODE AND CO. LTD., COLCHESTER LONDON AND ETON End of Project Gutenberg's Industrial Poisoning, by Joseph Rambousek	170,061	common-pile/project_gutenberg_filtered	60605	project gutenberg	project_gutenberg-dolma-0011.json.gz:1748	https://www.gutenberg.org/ebooks/60605.txt.utf-8
5jYbA4xfWzxRI47B	3.10: Reduction of Aromatic Compounds	3.10: Reduction of Aromatic Compounds After completing this section, you should be able to - write an equation to represent the reduction of a substituted benzene to a substituted cyclohexane. - identify the catalyst and reagents used to reduce aromatic rings. - compare the ease of reduction of alkenes with the difficulty in reducing benzene rings, and show how this difference in reactivity can be used in organic synthesis. - write an equation to illustrate the reduction of an aromatic ketone to an arene. - explain why Friedel-Crafts acylation, followed by reduction, provides a better route to primary alkylbenzenes than does direct alkylation. - show how a specified alkylbenzene may be prepared by a Friedel-Crafts acylation, followed by reduction. Specify all reagents, the structure of the intermediate ketone, and the necessary starting material. Catalytic Hydrogenation of Aromatic Rings Just as aromatic rings are generally inert to oxidation, they’re also inert to catalytic hydrogenation under conditions that reduce typical alkene double bonds. As a result, it’s possible to reduce an alkene double bond selectively in the presence of an aromatic ring. For example, 4-phenyl-3-buten-2-one is reduced to 4-phenyl-2-butanone using a palladium catalyst at room temperature and atmospheric pressure. Neither the benzene ring nor the ketone carbonyl group is affected. To hydrogenate an aromatic ring, it’s necessary either to use a platinum catalyst with hydrogen gas at a pressure of several hundred atmospheres or to use a more effective catalyst such as rhodium on carbon. Under these conditions, aromatic rings are converted into cyclohexanes. For example, o -xylene yields 1,2-dimethylcyclohexane, and 4- tert -butylphenol gives 4- tert -butylcyclohexanol. Reduction of Aryl Alkyl Ketones In the same way that an aromatic ring activates a neighboring (benzylic) C–H toward oxidation, it also activates a benzylic carbonyl group toward reduction. Thus, an aryl alkyl ketone prepared by Friedel–Crafts acylation of an aromatic ring can be converted into an alkylbenzene by catalytic hydrogenation over a palladium catalyst. Propiophenone, for instance, is reduced to propylbenzene by catalytic hydrogenation. Because the net effect of Friedel–Crafts acylation followed by reduction is the preparation of a primary alkylbenzene, this two-step sequence of reactions makes it possible to circumvent the carbocation rearrangement problems associated with direct Friedel–Crafts alkylation using a primary alkyl halide (Section 16.3). The conversion of a carbonyl group into a methylene group ( How would you make the following from benzene and an acid chloride? - Answer - Catalytic hydrogenation of aromatic rings requires forcing conditions (high heat and hydrogen pressure). Under milder conditions it is possible to reduce the double-bond of an alkene without reducing the aromatic ring. Notice in the above equation that H 2 /Pd does not reduce the keto-carbonyl group. Remember, however, that H 2 /Pd will reduce a keto-carbonyl group when it is directly attached to an aromatic ring (see equations 4 and 5 under Carbonyl Reductions). This reduction of the (C=O) group next to an aromatic ring is an important synthetic tool. Recall the Friedel-Crafts alkylation from Section 16.3. When attaching larger alkyl groups to arenes there is a possibility of rearrangement of the alkyl group structure. To generate the target compound (in this case n ‑propylbenzene) in a more controlled fashion, one can simply use the equivalent Friedel-Crafts acylation and then reduce the keto-carbonyl group next to the ring as a final step.	717	common-pile/libretexts_filtered	https://chem.libretexts.org/Courses/can/CHEM_232_-_Organic_Chemistry_II_(Puenzo)/03%3A_Chemistry_of_Benzene_-_Reactions_of_Aromatic_Compounds/3.10%3A_Reduction_of_Aromatic_Compounds	libretexts	libretexts-0000.json.gz:40506	https://chem.libretexts.org/Courses/can/CHEM_232_-_Organic_Chemistry_II_(Puenzo)/03%3A_Chemistry_of_Benzene_-_Reactions_of_Aromatic_Compounds/3.10%3A_Reduction_of_Aromatic_Compounds
H2Pu1FjyKvS08Wja	The roundworms of domestic swine : with special reference to two species in the stomach / by Winthrop D. Foster.	Washington, D. C., July 2, 1912. SIR: I have the honor to transmit herewith a manuscript entitled "The Roundworms of Domestic Swine, with Special Reference to Two Species Parasitic hi the Stomach," by Mr. W. D. Foster, of the Zoological Division of this bureau. I respectfully recommend its publication in the bulletin series of the bureau. The paper deals particularly with two species of nematodes which have recently attracted considerable attention in connection with the Federal meat inspection. The parasites are shown to be of wide distribution and frequency of occurrence hi American swine, and they are a source of possible serious injury to these animals. SUMMARY. Two species of roundworms belonging to the family Filariidse, of particular interest to helminthologists and veterinarians on account of their wide distribution and frequency of occurrence in American swine and the possibility that they may cause serious injury to their host, are given special consideration in this paper. One of these species, identified as Spiroptera strongylina, has recently been placed in a new genus, Arduenna, of which it is the type, and several errors regarding the anatomy of this parasite have been corrected. Another species, Arduenna dentata, has been found in China associated with Arduenna strongylina, and although not yet reported in American swine is mentioned in this connection, as further investigation may reveal its presence in this country. Arduenna strongylina is much more common in American swine than it is said to be in European swine, and has been found abundantly in the slaughterhouses at St. Louis, Chicago, South Omaha, and Kansas City, and has also been collected at Benning, D. C., and Bethesda, Md. Specimens of hogs' stomachs received from Chicago showed the worms deeply fastened in' the submucosa or embedded in necrotic tissue near which were deep ulcers. The condition suggested infection with Bacillus necrophorus, the inoculation of which might easily result from the burrowing of the worms; however, owing to the sterile condition of the specimens received, this could not be satisfactorily demonstrated. A similar diseased condition of the stomachs of hogs in Europe is attributed by Von Ratz (1899d)' to infection with Arduenna strongylina. Under the circumstances the worm should be regarded with grave suspicion, and general prophylactic measures for the prevention of the spread of infection are suggested. Commonly associated with Arduenna strongylina in this country is another worm, identified as Physocephalus sexalatus, first described by Molin (1860b) from specimens from the peccary (Dicotyles labiatus) from Brazil; also found by him associated with Arduenna strongylina from the wild boar in Germany. It is also reported by Von Linstow (1879b) (who apparently mistook this species for Arduenna strongylina) and Piana (1897e), from Europe, and by Railliet and- Henry (1911b), from Madagascar and Indo-China, in the former case associated with a severe gastritis. According to the writer's experience, Physocephalus sexalatus is almost as widely distributed as Arduenna strongylina, since out of eight lots of specimens of the latter species, specimens of Physocephalus sexalatus were found in all but one. In a mixed infection, however, it has never been found as abundantly as Arduenna strongylina. This worm has apparently the same habit of injuring the mucosa as has Arduenna strongylina, as both species were found in the same necrotic tissue in a hog's stomach. It must therefore be considered only less dangerous because it is less abundant, and should be subject to the same treatment suggested for infestation with Arduenna strongylina. 8 THE ROUNDWORMS OF DOMESTIC SWINE. Nothing is known in regard to the life cycle of these parasites, but their wide distribution and frequency of occurrence suggest a simple life history without an intermediate host. The fact that the eggshells of both species are relatively thick would seem to indicate that the embryos are not liberated until the shell is dissolved by the gastric juice of the host. From the fact that the embryos are fairly well developed before oviposition, it may be inferred that the eggs require but a short period of incubation. INTRODUCTION. Nematodes occurring in the stomach are commonly present among swine in the United States. These have usually been considered by veterinarians, pathologists, and others who have had occasion to mention them as belonging to the species Spiroptera strongylina Rudolphi, 1819, although some have expressed a doubt as to the correctness of the identification. In addition to the forms which have been identified as Spiroptera strongylina, Hassall and Stiles (1892a) have described a species named by them Strongylus rubidus, and which has since been collected from domestic swine in Europe. Recently a zoological study of specimens of nematodes in the helminthological collection of the Bureau of Animal Industry, collected from the stomachs of hogs in various parts of the United States, was undertaken by the present writer, largely as a result of reports from inspectors relative to the prevalence of nematodes in the stomachs of swine, Drs. J. J. Brougham and T. B. Pote, of the St. Louis station, having been among the first in the Federal service to give attention to the subject from the standpoint of meat inspection. As a result of this study and of a comparison of these specimens with specimens of Spiroptera strongylina received from Europe, the conclusion has been reached that in several particulars the descriptions of Spiroptera strongylina commonly given by European writers are in error, and that the forms commonly identified as Spiroptera strongylina represent two distinct species, one of them Spiroptera strongylina, the other corresponding to Physocephalus sexalatus (Molin, 1860) Diesing, 1861, hitherto considered a rare parasite and until recently reported only once for domestic swine. According to Stiles and Hassall (1905b), the genus Spiroptera is preempted by the genus Acuaria Bremser, 1811, whose type is anthuris. This species is also the type of Dispharagus Dujardin, 1845, a genus based largely on certain nematodes of birds and not found in mammals. According to this ruling, the genus Acuaria is confined to certain parasites of birds and fishes characterized by a differentiation in the structure of the esophagus. As Spiroptera strongylina does not conform to the type of Acuaria or the characteristics of the genus, a new genus to include these forms is necessary. This deficiency has been supplied by the creation of a new genus, Arduenna, by Railliet and Henry (1911), Spiroptera strongylina being taken as the type. Both Arduenna and PJiysocephalus, together with Simondsia paradoxa, belong in the family Filariidse,1 and are included by Railliet and Henry (191 Ib) in the new subfamily Arduenninae. FAMILY FILARIIDSE, GLAUS, 1885. FAMILY DIAGNOSIS. — Nematoda: Body long, filiform. Mouth surrounded with papillae, or provided with two lips. Esophagus slender, without posterior bulb. Males with a single spicule or with two unequal spicules. Females with two ovaries; vulva usually in front of the middle of the body. Usually ovoviviparous. Development in many cases requires an intermediate host. SUBFAMILY DIAGNOSIS. — Filariidae: Mouth with two lateral lips leading into a pharynx marked with cuticular ridges in the form of spirals or rings. Spicules unequal, the longer several times the length of the shorter. Four pairs of preanal papillae. Eggs containing embryos when oviposited. Genus ARDUENNA Railliet and Henry, 1911. GENERIC DIAGNOSIS. — Filariidee: Body subcylindrical, attenuated anteriorly, posteriorly somewhat broader, usually curved in a semicircle, marked by a narrow, longitudinal cuticular wing on the left side, extending nearly the length of the body. Cuticle densely striated transversely. Mouth with two lateral lips, each lip with three lobes, leading into a small buccal capsule containing two lateral teeth, and followed by a cylindrical pharynx marked with cuticular ridges forming a series of spirals. Esophagus continuous, gradually broadening posteriorly and occupying from onefourth to one-third of the body length. Caudal end of the male curved in a single turn. Bursa asymmetrical, the right bursal wing being broader than the left wing, furnished with five pairs of stalked papillae asymmetrically arranged, of which one pair is preanal, three pairs are adanal, and the fourth pair is postanal. Bursal membrane marked with longitudinal and transverse striae, giving it a wrinkled appearance. Anus surrounded by a cuticular thickening, serrated on the outside edge. Spicules long and very unequal, the longer five to seven times the length of the shorter. Vulva anterior of the middle of the body. Eggs with thick shells containing embryos at the moment of oviposition. Parasitic in the stomachs of Suidse. » Diesing (1861a) proposed the family name Spiruridea for a group of nematodes distinguished from FUaria by the curl or spiral twist of the tail of the male. This family is not accepted by most recent writers on the ground that it is not based on sufficiently characteristic morphological features, and that the name does not conform to the rules of zoological nomenclature. Oerley(18S5a), Leiper (1908), and Railliet and Henry (1911b) use the name Spiraridae, apparently modifying Diesing's (1861a) family name Spiruridea to conform to the present zoological nomenclature. The family name Spiropterldae Is proposed by Leroer (1911). Owing, however, to the apparent invalidity of the name Spiroptera, the present writer prefers not to use either the family name Spiruridse or Spiropteridse, and although it is evident that the genera Arduenna and PJiysocephalus, and other genera as well, will ultimately be separated from the Filariidse, it is not considered desirable to attempt such a revision until a more careful study has been made of the various species involved. In the present paper, therefore, A rduenna and Physoccphalus are retained in the family Filariidse but included under the subfamily Arduenninse, Railliet and Henry, 1911. SPECIFIC DIAGNOSIS. — Cuticule densely striated transversely, increasing in thickness toward the anterior extremity, which is furnished with two cervical papillae placed asymmetrically, the left being about 190 p and the right 390 fi from the anterior extremity. Beginning at a point 280 fi from the anterior end on the left side, a narrow cuticular wing gradually increasing to a maximum breadth of 35 p. extends to a point about 2 mm. from the posterior extremity. Mouth 44 to 45 ft in diameter with two lateral lips each with three lobee, having a small round papilla at the base of each of the lobes. Just below the lips and projecting into the mouth cavity are two chitinous teeth, formed by a prolongation of, the wall <?f. the pharynx (fig. 1). The pharynx, 29 /* wide by 83 to 98 p long, is marked on the inside by a series of chitinous ridges in the form of continuous spirals (or a multiple spiral), all running in the same direction and appearing like the threads of a quadruple screw. Esophagus 3.1 to 3.7 mm. long, or about one-fourth of the body length, and 117 to 127 ft wide at its widest part near the base. Nerve ring 0.35 mm. and excretory pore 0.48 mm. from the anterior end. Male 10 to 15 mm. long, averages about 13 mm. in length; 301 to 387 p wide at the widest part just above the bursa. The bursal wings extend from a point about 1.2 mm. from the caudal extremity to the tip, the body ending in a blunt point. Bursal wings irregularly ovate, ^^^^^^^.^ Female 16 to 22 mm. long, 263 to 420/i wide; average maximum width 368 p, at a point about one-third of the distance from the head to the caudal end. For the next third of the distance the width remains constant except for a slight constriction in the region of the vulva. Beginning at a point about two-thirds of the distance from the head to the caudal end, where one of the uteri turns back on itself, the width gradually diminishes and then abruptly decreases a short distance in front of the anus. Anus 215 to 275 p from the caudal tip (fig. 4). The orbicular naked vulva opening near the left side close to the lateral cuticular wing is slightly anterior of the middle of the body, dividing the worm anteriorly and posteriorly in the ratio 5 : 6. Vagina uniform, about 49 p in diameter, 1.7 mm. long, FIG. 2.— Arducnna strongylina. Bursa of male, ventral view, cl., cloaca; l.b.w., left bursal wing; I. sp., long spicule; po. p., postanal papillae; pr. p., preanal papillae; r. b. w., right bursal wing; «. sp., short spicule; v. r. c., ventral ridge of the cuticle. X75. (Original.) FIG. 3.— Arduenna strongylina. Posterior end of body of male, viewed from right side. I. sp. , long spicule; s. sp., short spicule. X 65. (Original.) Ho mm. FIG. 4.— Arduenna strongylina. Posterior end of body of female, viewed from left side. a. , anus; ov., ovary; p. ut., posterior uterus; red., rectum; ter. p., terminal papilla. X 150. (Original.) female (fig. 1), there are four separate ridges, the usual number for females. Males have, as a rule, but three spirals. Kailliet and Henry (191 Ib) mention 2 to 3 spiral ridges for males and 4 to 5 for females. The retractor muscles controlling the movements of the right spicule are a pair of narrow lamellar strips, longitudinally finely striated, asymmetrically twisted in the center, attached at the posterior end to the spicule and at the anterior end to the ventral side The vas deferens appears as a tube of darker color than the intestine, about 130 fjL in its average diameter, and extending throughout the posterior third of the body length. About 450 p from its terminus it rapidly diminishes in diameter toward the cloaca, and in the specimen figured (fig. 8) is bent in the shape of the letter S. The seminal tube is very long and convoluted, resembling in appearance the ovaries of the female. Near the posterior end of the male the intestine, 123 // wide, first crosses above the vas deferens toward the dorsum, then curves underneath as it approaches the cloaca. Its terminus was obscured by the organs lying above it. In the specimen figured (fig. 8) the sheath of the right spicule is much contracted and appears as a dark-colored bag too short to contain the entire spicule and within which the base of emb., embryo; sh., sheii. x 1,450. sexalatiLS, probably assists in maintaining the position of the male in copulation, as suggested by Ciurea (1911). The anus is partially encircled by a rim of thickened cuticle, the outer edge of which is ornamented with serrated cuticular projections. This cuticular thickening extends along the posterior and left sides of the anus, forming about FIG. 5. — Arduenna strongylina. Ventral view of middle of body of female, a. tit., anterior uterus; int., intestine; j. ut., junction of the uteri; I. c. w.', lateral cuticular wing; p. ut., posterior uterus; v. vulva; va., vagina. X 58. (Original.) surface of the body of the male, close to the tip of the tail. These could not be seen in the specimens studied by the writer. The rectum (fig. 4) of the female is about 80 /z in maximum width and nearly as long as the distance from the anus to the tip of the tail. In the region immediately posterior of the anus several fine lines Short spicule with retractor muscles viewed from right side. ret. m., retractor muscles; . sp., short spicule. X 80. (Original.) hematoxylin it resembles the thickened wall of the pharynx. The same drawing (fig. 9) also shows that the vagina first passes between the cuticle and muscular wall as it crosses the body to extend along the right side. In several of the specimens examined by him, Ciurea (1911) noticed a drop of hardened cement at the opening FIG. 8.— Arduenna stroru/yUna. Posterior end of body of male, viewed from left side, cl., cloaca; int., intestine; I. b. w., left bursal wing; po. p., postanal papillae; pr. p., preanal papillae; pr. r. , perianal ring; sh. I. sp. , sheath of long spicule; sh. s. sp., sheath of short spicule; ». sp., short spicule; v. def., vas deferens; v. r. c., ventral ridge of the cuticle, X 58. (Original.) FIG. 9. — Arduenna ttrongylina. Cross section through body of female in the region of the vulva. bd. w., body wall; cut., cuticle; «., eggs; int., intestine; tit., uterus; v., vulva; va., vagina. Enlarged. ( After Ciurea, 1911. Text fig. 1, p. 131.) lel with its dorsal limb, until its outline is lost to view beneath the mass of eggs distending both uteri and filling the body cavity from the end of the esophagus to within a short distance of the anus, greatly obscuring the outlines of the organs. Throughout its visible length this uterus is of nearly uniform diameter, about 95 fi. The distal ends of the two uteri are at opposite extremities of the worm; the uterus that first extends posteriorly ends anteriorly at a point 613 fi anterior of the base of the esophagus in a long convoluted ovary crowded into the narrow space between the esophagus and the lateral muscular wall. The other uterus, running in a similar but reverse direction from the uterus of the posterior uterus, like that of the anterior uterus, is nearly i Such a secretion is not, however, uncommon among nematodes. The writer has collected many specimens of (Esophagostomum columbianum the vulva of which was closed by a plug of dark-red secretion Insoluble in alcohol but which could easily be removed by a needle. Specimens of this parasite have been observed so firmly welded in copulation that hot alcohol did not cause their separation and they yielded only to forcible traction with a needle or forceps. uniform, about 95 fi. The posterior ovary, much convoluted, fills most of the space between the anus and the terminus of the posterior uterus (fig. 4). The ovaries are long filiform tubes, 34 /j. in diameter in their narrowest part. The thick-shelled eggs are covered with a thin irregular membrane resembling the albuminous membrane of an ascarid egg. Under high power a faint line at either pole can be seen running transversely through the thickness of the shell, suggesting an operculum. The embryo is surrounded by a thin envelope, differentiated from the shell by its greater translucence and lack of granulation (fig. 6). Most of the eggs in the uterus contain well-developed embryos, but a few near the ovaries appear in the morula stage. The shell, including the translucent membrane surrounding the embryo, is 4 // thick, the embryo occupying a space 11 // by 24//. and 11. The first specimens of Arduenna strongylina were collected by Bremser and figured by him in his Icones Helminthum (Bremser 1824c). They were first described, however, by Rudolphi (1819a, p. 237). His description may be freely translated as follows.: Head slender, continuous, mouth orbicular, body somewhat attenuated anteriorly, tail of male coiled either in a single spiral or in a spiral and a half. A broad wing extending on either side of the tail. Spicule very long. Apex of the tail very short, naked. Apex of the tail of the female depressed, straight, subacute. Gurlt (183 la) is the first on record to collect the worm from domestic swine. His description of the anatomy of Spiroptera strongylina follows Rudolphi's, but contains also the statement that the vulva is situated a short distance in front of the anus. He describes the mouth as smooth, without papillae. Subsequently (Gurlt, 1847a) he added to his description a note on the anatomy of the pharynx, the first reference to this structure, which he describes as banded by two spiral muscles (a misinterpretation of the spiral chitinous ridges of FIG. 11 .—A rduenna strongylina. General view of body of female from left side, a., anus; ut., uterus; v., location of vulva. X 7.5. (Original.) Molin (1860b) describes the vulva as situated posteriorly, and gives the following measurements: Males, 11 to 15 mm; females, 15 to 23 mm, which figures agree closely with the writer's measurements of Arduenna strongylina. Schneider (1866a) reexamining Rudolphi's material, gives a correct drawing of the bursa of Arduenna strongylina, showing 5 pairs of papillae, / of which one pair is postanal, and describes the / anus as surrounded posteriorly by a crown of serrated cuticular prominences (fig. 13). His description, however, does not in all respects agree with his drawing, as he states that there are 6 pairs of papillae while the drawing shows only 5 pairs. His description is also in error in regard to the position of the vulva, which he TlG- ] describes as directly in front of the anus. Von Linstow (1879b) states that the two spicules measure respectively 0.72 and 0.26 mm. and that the mouth is surrounded with 6 round papillae curved forward (fig. 14). His drawing shows the pharynx with a series of parallel ridges instead of a spiral. A comparison of his drawing (fig. 14) with the anterior end of PJiysocephalus sexalatus (fig. 15) gives rise to the suspicion that Von Linstow has mistaken this species for Arduenna strongylina, an opinion first expressed by Railliet and Zuern (1882 a) is the first to mention the narrow lateral wing, extending longitudinally along one side of the body. He describes it, however, as being in a median position. As has been shown, it extends along the left side only. Stossich (1897b) states that the long spicule is three times the length of the short spicule, a ratio evidently derived from Von Linstow's (1879b) measurements. FIG. 13. — Arduenna strongylina. Bursa of male, ventral view, cl., cloaca; po. p., postanal papillae; pr. p., preanal papillae; pr. r., perianal ring. Enlarged. (After Schneider, 1866a, p. 101.) FIG. 14. — PhysocephaliM sezalatus. Lateral view of cephalicend. lab. p., labial papillae; ph., pharynx. Enlarged. (After Von Linstow, 1879b, Pl.V, fig. 11.) and the descriptions of this species by European observers. As no European specimens were at hand with which to compare the specimens collected in this country, it was concluded either that the tera slrongylina. The specimens sent to Von Linstow were considered by him to be a different species from Spiroptera strongylina. There is, however, no question that certain European specimens recently received from Prof. Gedoelst, of Brussels, are specifically identical with the American show that the long spicule varies between2.24 and2.95 mm. in length, while the short spicule is between 457 and 619 // in length. The corresponding measurements given by Ciurea are, long spicule, 977 //; short spicule, 221 /t. The measurements given by Railliet and Henry (191 Ib) are, long Arduenna strongylina, considered a rare parasite by Dujardin (1845a), Neumann (1892a), and Railliet (1893a), is now known to have a wide range. In this country at least it is very common, as will be shown later. In Europe it has been collected from the wild boar by Bremser (Rudolphi, 1819a) in Germany, and is reported by Dujardin (1845a) in Austria, and by Railliet and Henry (191 Ib) in prance from the same host. It has been reported for domestic swine 'in Germany (Gurlt, 183 la), Hungary (Von Ratz, 1899d), Italy (Piana, 1897e), and Roumania (Ciurea, 1911). Most helminthologists, following the older writers, state that the parasite is rare and occurs somewhat more commonly in the wild boar than in domestic swine. Dujardin (1845a) states that "out of 19 wild boars dissected at the museum of Vienna, only 2 had this worm in the stomach." In Roumania, Ciurea found it in 9 out of 72 healthy swine, between 1 and 27 specimens being found in a single host. Outside of Europe it has been reported by Von Linstow (1886c) from Turkestan, and by Railliet and Henry (191 Ib) from Annam Province, Indo-China. Some doubt, however, may be expressed regarding the identity of the parasite reported by Von Linstow (1886c) since, as has been shown, Von Linstow (1879b) has apparently confused PJiysocepTialus sexalatus with Arduenna strongylina. The references to this parasite in the United States will be considered in detail in another part of the paper. Judging from its abundance in the United States, it seems not improbable that a careful examination of hogs' stomachs in European slaughterhouses would show, a more widespread infection than hitherto reported. The specimens received by this bureau from Gedoelst were unaccompanied with any data giving the host or locality. Doubtless many veterinary schools and colleges throughout Europe contain specimens both of this parasite and of PTiysocephalus sexalatus which, like the specimens received from Gedoelst, have never been reported in the literature. An examination of the literature reveals only two authentic hosts for Arduenna strongylina, namely, the European wild boar and domestic swine, although most writers subsequent to Diesing (1851a) have included the peccary in their lists of hosts. Diesing (185 la) identified as Spiroptera strongylina some specimens of worms in the Vienna museum collected by Natterer in Brazil, April 24, 1826, from the stomach of the white-lipped peccary (Dicotyles labiatus) and labeled Spiroptera suis lalnati. As a result of his identification he (Diesing, 1851a) added Dicotyles albirostris ( = Dicotyles Idbiatus Cuv.)1 to the previously known hosts of Spiroptera > Dr. H. W. Henshaw, Chief of the Bureau of Biological Survey of the United States Department of Agriculture, in reply to a letter regarding the synonymy of Dicotyles labiatus, states (Feb. 24, 1911) that, according to Dr. J. A. Allen, of his bureau, Dicotyles labiatus and albirostris are synonyms, labiatus having preference as being the older term, the correct name, however, being Tayassu pecari Fischer. FIG. 16.— Arduenna dentata. Median view of cephalic end. ph., pharynx; t. b. c., teeth of the buccal capsule. Enlarged. (After Von Linstow, 1904f, PI. I, flg. 5.) strongylina. The specimens were subsequently studied by Molin (1860b), recognized as a new species, and named by him Spiroptera sexalata. Later helminthologists, although accepting Molin's species, have continued to include Dicotyles Idbiatus among the hosts reported for Arduenna strongylina, apparently ignoring the fact that Molin's (1860b) correction of Diesing's (1851a) identification eliminates the peccary as a host of Arduenna strongylina, since this, species has never been reported in the peccary except by Diesing (1851a). Stossich (1897b) apparently considered Dicotyles albirostris and D. labiatus as separate species, listing under the former Spiroptera strongylina and under the latter the parasites collected by Nattererfrom the peccary and described by Molin (1860b). The stomach appears to be the 14.6 mm. long, the nerve ring surrounds the esophagus 2.64 mm. from the head end, and the excretory pore opens at a point situated 0.31 mm. behind it. The male resembles that of Spiroptera strongylina. The spicules are respectively 0.35 and 0.92 mm. long, the shorter one bearing at its end a barb. Immediately anterior of the anus on each side there are four preanal papillae situated close together; behind it there is one papilla. All have long stalks. The anus is surrounded by a broad ring, notched externally; the bursa shows longitudinal rows of oval scales. (Fig. 17). The female grows to a length of 55 mm. with a width of 1.10 mm. The short conical tail is curved over the back; the vulva is placed far behind the middle and divides the body in the ratio of 70 to 23. The eggs are small, thick shelled, and cylindrical, measuring 0.039 by 0.017 mm. FIG. 17.— Arduenna dentata. Bursa of male, ventral view. d., cloaca; I. b. w., left bursal wing; I. sp., long spicule; po. p., postanal papillse; pr. p., preanal papillae; pr. r., perianal ring. Enlarged. (After Von Linstow, 1904f, PL I, fig. 7.) The specimens described by Von Linstow were from the stomach of Sus cristatus at Chilaw, Ceylon, and are deposited in the museum of Colombo. Railliet and Henry (191 Ib) identify with Von Linstow's (1904f) Spiropteradentata certain parasites collected from the stomachs of pigs slaughtered at Hue", Annam Province, Indo-China, and include them in the genus Arduenna. The specimens examined by Railliet and Henry (191 Ib) differ, however, from Von Linstow's (1904f) description in the position of the vulva and the length of the spicules. According to the former authorities, the position of the vulva is difficult to observe, but the spicules measure 3.75 to 4.23 mm., and 540 to 650 fj., respectively. The principal differences between Arduenna dentata and Arduenna strongylina are the greater size of the former and the fact that the chitinous ring surrounding the cloacal opening, described for Arduenna strongylina, forms an almost complete circle in the case of Arduenna dentata, while in Arduenna strongylina it includes only the posterior and left sides. Railliet and Henry's measurements for Arduenna dentata are: Males: 25 to 35 mm. long by 700 to 800 //broad; females: 40 to 55 mm. long by 1.1 to 1.2 mm. broad. GENERIC DIAGNOSIS. — Filariidse: Body elongated, subcylindrical, slightly tapering anteriorly. Head marked off from the rest of the body by a cuticular inflation ending abruptly in a circular line a short distance anterior of the posterior end of the pharynx. Extending from the base of the cuticular inflation to about the middle of the body are 6 lateral cuticular wings, 3 on each side, the middle wing of each 3 being broader than the other two. Mouth with 2 trilobed lips, with a rounded papilla on each lobe, and leading into an inconspicuous buccal capsule without teeth. Pharynx relatively long and broad, marked by prominent ridges forming both spirals and simple rings, and extending the length of the pharynx on the inside. Tail of the male twisted spirally, furnished with a narrow symmetrical bursa supported by four pairs of preanal papillae. Spicules long and unequal, the left spicule about five times the length of the right spicule. Vulva somewhat posterior of the middle of the body; eggs smooth, with thick shells, containing well-developed embryos at the moment of oviposition. Endoparasitic in the stomach of suidae. SPECIFIC DIAGNOSIS. — Physocephalus: Head about 60 ji in diameter at the anterior end, furnished with 2 tiilobed lips, each lobe being ornamented with a thick, rounded chitinous papilla (fig. 15). The cuticle of the head, extending from the mouth to a point 232 p from the anterior end, ia more or less inflated. Pharynx cylindrical, 263 to 315 p long by 53 p wide, furnished with a spiral band which usually breaks up into separate rings in the middle of its course and resumes the spiral toward the posterior end. The number of turns to the spiral varies between 21 and 25. There is a cervical papilla on the left side, 281 ft from the anterior end. The excretory pore opens on the right side, 526 p from the anterior end. The lateral cuticular wings, 3 on each side, commencing at the base of the cephalic cuticular inflation, extend posteriorly for a distance about one-third of the body length. The middle wing of each three is 00 p wide at its middle, the point of greatest width. The other wings are about half as wide (fig. 18). into a fairly regular spiral, having usually three turns. Long spicule grooved on the ventral side, 2.1 to 2.25 mm. in length, or five to six times the length of the short spicule, very slender, gradually tapering to a fine needle point. Short spicule 300 to 350 p long, relatively broad at its base, suddenly tapering to a fine point. The ventral surface of the short spicule is provided with a narrow wing extending nearly to the tip. Bursa furnished with eight pairs of papillae (fig. 20). Of these the four pairs of preanal papillae are long and stalked; the postanal average about 16 or 17 mm. Maximum width 333 to 450 p in the region directly anterior of the anus. The body rapidly increases in diameter from the anterior end to the region of greatest width of the lateral cuticular wings. At this point the diameter is nearly as great as in the region of the anus. It then rapidly diminishes to half as much at the end of the first third of the body; then slowly increasing, it reaches a maximum near the anus and abruptly diminishes, the body ending in a blunt point furnished with a mucronate tip. Anus 120 p from the caudal end, 50 p in diameter (fig. 21). Vulva posterior of the middle, 35 p in diameter, dividing the body in the ratio of 9 to 8. The vagina extends posteriorly (fig. 22). Uterus bilobed, the ovaries lying at opposite extremities. Eggs 34 by 15 ft, slightly flattened at the poles. Embryo well developed before oviposition (fig. 23). lo.mm. FIG. 18. — Physocephalus sexalatus. Dorsal view of anterior end of body. c. cut. inf., cephalic cuticular inflation; c. p., cervical papilla; ««., esophagus; ex. p., excretory pore; lab. p., labial papillae; I. c. to., lateral cuticular wings; n. r., nerve ring; ph., pharynx. X 150. (Original.) As already mentioned, Physocephalus sexalatus was first identified as Spiroptera strongylina by Diesing (185 la). Molin (1860b) subse- the type and only species. The specimens studied both by Molin and Diesing were collected by Natterer from the white-lipped peccary in Brazil, April 24, 1826, and deposited in the Vienna Museum labeled Spiroptera strongylina suis labiati. Molin's (1860b) somewhat meager description sums up the salient points (the lateral wings and spiral tail of the male) by which Physocephalus sexalatus may be recognized. He describes the males as 7 mm. long and 2 mm. wide, and the females as 9 to 13 mm. long and 3 to 5 mm. wide. The mouth is described as bilobed, each lobe with a three-cornered margin. Diesing (1861a), although creating a new genus from Molin's species, adds little to our knowledge of its anatomy. ently mistaken Physocephalus sexalatus for Arduenna strongylina. His measurements of the spicules (0.72 mm. for the long and 0.26 mm. for the short spicule) are, however, much too short for A. strongylina and also for P. sexalatus. FIG. 19.— Physocephalus sexalatus. Posterior end of body of male. 6. w., bursal wing; cl., cloaca; 1. p.,long spicule; pr. p., preanal papillae; ». sp., short spicule; v. r. c., ventral ridge of the cuticle. X 50. (Original.) ture of the lateral wings, illustrating the description with drawings, which were of great value to the present writer in verifying his identification. In common with Railliet and Henry (191 Ib) the present writer was unable to find the pair of papillae depicted by Von Drasche (1884a, fig. 24 of this article) close to the edge of the anus. Ciurea (1912), however, depicts a pair of papillae immediately posterior of the anus, which he states are not easily seen. At the extreme tip of the tail Von Drasche (fig. 24) shows three pairs of minute apparently sessile papillae. In reality there are four pairs of minute stalked papillae at this point. These appeared very clearly with a high FIG. 20.—Physocephalus sexalatus. Bursa of male, viewed from left side, cl., cloaca; I. b. w., left bnrsal wing; 1. sp., long spicule; po. p., postanal papillae; pr. p., preanal papillae; r. 6. w., right bnrsal wing; sft. s.sp., sheath of short spicule; s.sp., short spicule; v. w., ventral wing of short spicule. X 100. (Original.) power in mounts presenting a somewhat lateral view (fig. 20). The structure at the tip of the tail with its rows of minute papillae is not unlike that depicted by Ciurea (1911) for the bursa of Arduenna strongylina. As already stated, however, no such structure was seen by the present writer on the bursa of this species. In a cross section of P. sexalatus (fig. 25) Von Drasche shows that the projecting cuticle forming the lateral wings has corresponding depressions inward. Stossich's (1897b) description of P. sexalatus follows that of Molin and Von Drasche. Piana (1897e), in an article on Simondsia paradoxa, mentions finding two other species of nematodes in the same bottle containing the specimens of Simondsia. He identified these as being Spiroptera strongylina and PhysocepJialus sexalatus. These .specimens were from an Italian pig. Railliet and Henry's (191 Ib) description of Physocephalus sexalatus is based on specimens collected from a hog slaughtered at Hue", Indo-China. These authors also report having observed it in material from Madagascar in 1905. Ciurea (1912) reported Spiroptera sexalata in domestic swine slaughtered at Piatra Neamtz, Roumania, in 1910. Five out of 72 healthy swine were infested with from one to thirty of these para- FIG. 21. — Physocephalus sexalatus. Posterior end of body of female, ventral view. a. , anus; a. ut., anterior uterus; int., intestine; /. a. ut., loop of anterior uterus; ov., ovary; p. ut., posterior uterus. X 50. (Original.) Jfomm. FIG. 22.— Physocephalus sexalatus. Ventral view of body of female in the region of the vulva, int., intestine; ut., uterus; v., vulva; va., vagina. X 95. (Original.) sites in the stomach. In three cases they were found associated with Arduenna strongylina, and once with Gnafhostoma hispidum. In this latter case the parasites were found in the ulcer caused by G. Tiispidum. The worms were partially or entirely buried in the mucosa, but no lesions were attributed to them. Ciurea's (1912) .description and drawings of Physocephalus sexalatus agree in most respects with the present writer's observations, the few differences being noted in the course of this article. A subsequent examination of the fourth stomachs of six dromedaries revealed numerous specimens of this species hidden between the folds of the mucosa, associated with Hsemonchus contortus. While the description of the specimens agrees in general with the present writer's observations, the measurements are all somewhat larger. The width of the middle lateral wing (110 to 120 /£ as given by Seurat) is over twice as great as that given by the present writer, while the vulva is described as located at the anterior third of the body, instead of slightly posterior of the middle, as described by Railliet and Henry (191 Ib), Ciurea (1912), and Foster (1912) (the present article). Seurat (1912) also found in the dromedary another form which he considers as a variety and designates as var. cristata. This form is distinguished from the typical species by having four longitudinal crests on the head, formed by four cuticular folds, and having four cuticular spines in the mouth cavity. In this variety the position of the vulva is not constant, but varies from the posterior third of the body to an anterior position. As Seurat's (1912) measurements of Physocephalus sexalatus differ considerably from the present writer's, and as the species has hitherto been reported only in the Suidse, it would seem desirable to reserve an opinion until his statements can be confirmed. The stomach is the normal location for Physocephalus sexalatus. Von Linstow (1879b) reports Filaria strongylina as collected from the small intestine of a hog by Dr. V. Bering, of Stuttgart. As has been shown, Von Linstow apparently confused Physocephalus sexalatus with Arduenna strongylina; it would seem therefore, that P. sexalatus may occasionally occur in the small intestine. In most specimens examined by the author the cuticle of the head appears as shown in fig. 18, which is closely similar to the form FIG. 24.— Physocephalus sexalatvt. Bursa of male, ventral view. ad. p. , adanal papillae; I. b. w., left bursal wing; Z.sp.,longspicule; po. p., postanal papillae; pr. p., preanal papillae; r. b. w., right bursal wing; s.sp., short spicule. X280. (After Von Drasche, 1884a, Pl.XTV,flg.3.) FIG. 25. — Physocephalussexalattu. Cross section through anterior part of body. bd. w., body wall; I. c. w., lateral cuticular wings. X 280. (After Von Drasche, 1884a, PL XIV, fig. 4.) depicted by Von Drasche (1884a). In about 20 per cent of the specimens examined, however, the cuticle, from the lips to the beginning of the lateral cuticular wings, is inflated into two hemispherical vesicular wings (fig. 26). This second form is not mentioned by Molin (1860b) or Von Drasche (1884a), but possibly may be referred to byDiesing (186 la) in the expression "epidermide in bullam inflata tunicatum" in his description of the genus PJiysocephalus. The pharynx of P. sexalatus is about three tunes as long and twice as broad as that of Arduenna strongylina, and this, together with the lateral wings characteristic of the genus, are the salient points in distinguishing the females of the two genera. At first sight the ridges of the pharynx appear to form separate rings and are so end of the pharynx they are again joined into a simple spiral (fig. 18) . The final loop of the anterior spiral forms the first ring of the series, and the beginning of the posterior spiral takes its origin from the lower part of the last ring. The number of loops to the spirals and the number of sep arate rings is sub j ect to considerable variation. A rather extreme case is seen in fig. 27. Here the first spiral has five which are two detached rings. The final spiral consists of 11 continuous loops. In every case, however, so far as observed, the ridges form both spirals and rings, commencing and ending with a spiral, and FIG. 26.— Physocephalus sexalatus. Ventral view of body offemale. a., anus; c.cut. inf., cervical cutieular inflation; 1. c. w., lateral cuticular wings; p., vulva. X 7. (Original.) anterior end. As seen by the present writer the left papilla has a broad base and a blunt point and penetrates the cuticle 281 /i from the anterior end, or a little anterior of the base of the cephalic inflation. The right papilla was not seen by the present writer, but on the right side, not far from the location of the papilla as given by Railliet and Henry (191 Ib), the excretory canal opens. The end of the canal is a slender tube penetrating the middle lateral wing and looking not unlike a long stalked papilla (fig. 18). Its true nature has been shown by Ciurea (1912), who made a cross section of the. worm at this point. The lateral situation of the excretory pore is apparently unique among nematodes, the usual situation being ventral. The lateral cuticular wings unite just posterior of the base of the cephalic inflation (fig. 18). Here the cuticle forms an inverted pocket like the handle of a table drawer (fig. 27). The lateral cuticular wings are densely striated at the base, giving them a puckered appearance. Although the cuticle of the entire body is striated, these striations appear more promi- FIG. 27. — Physocephalus sexalatus. Lateral view of anterior end of body. c. cut. inf., cervical cuticular inflation; cut., cuticle; es., esophagus; ex. p., excretory pore; lab. -, , . P., labial papiii®; i. c. «., lateral cuticular nently on the lateral wings, particularly at their base, than elsewhere. The esophagus, about four-fifths of the length of the lateral wings, is densely striated transversely, with a very narrow lumen; nerve ring 439 // from the anterior end (fig. 18). The intestine is more or less convoluted throughout its course, especially posteriorly. The spiral of the caudal end of the male appeared in a few cases as a single coil like that of Arduenna strongylina. In other cases it consisted of an irregular double twist (fig. 28). In the greater number of specimens examined, however, it formed a broad open spiral like a corkscrew (fig. 19). Comparing the spiral to the thread of a screw, and considering the tip of the tail as the point of the screw, the spiral resembles a left-handed screw with three (rarely four) threads; no cases were seen in which the spiral revolved in the opposite direction. as symmetrical by Railliet and Henry (191 Ib) and are so depicted by Von Drasche (1884a). The right wing is, however, a little longer than the left wing (fig. 19). Ciurea (1912) considers that it is also narrower, but this statement could not be verified by the present writer. Ciurea (1912) states that the bursal wings extend throughout the twisted portion of the tail. As seen by the present writer they extend only about half this distance (fig. 19). The cuticle on the ventral side of the male (fig. 19), commencing at some distance anterior of the spiral, is marked with longitudinal striations intercepted by transverse lines, appearing under high power as longitudinal folds of the cuticle separated by transverse ridges. A similar structure has already been noted on the ventral surface of Arduenna strongylina (fig. 2) . As in most nematodes, the papillae are arranged symmetrically on either side of the median line. Their grouping and structure have already been discussed. The intestine is much convoluted, growing broader close to the cloaca. The vesicula seminalis occupies most of the body cavity in the posterior end, maintaining a fairly uniform diameter until it disappears dorsal of the intestine which conceals the ductus ejaculatorius. The long convoluted testis which extends to the middle of the body presents no specific characteristic features. The anus is FIG. 28.— Physocephalus sexalatus. General view of body of male. 5. , bursa; es. , esophagus; p.,spicules. X 23. (Original.) serrated ring. I The vulva (35 ft in diameter), as in Arduenna strongylina, apparently occupies a somewhat lateral rather than ventral position, opening toward the right side (fig. 22). It is situated just below the middle of the body, dividing the worm in the ratio of 9 to 8. According to Ciurea (1912) the cuticle in the region of the vulva is marked with longitudinal thickenings which may interlock with the cuticular ridges on the ventral surface of the male, and thus assist in maintaining the position of the male in copulation. The vagina, extending posteriorly along the right side, is at first 50 ft in diameter, but gradually broadens to 105 ft at its posterior end, where it disappears from the ventral side, extending dorsal of a lobe of the uterus. The distance from the vulva to this point is 976 /. The wall of the vagina is relatively thick, composed of transverse muscle fibers. The lumen is 20 // in diameter. Eggs containing well-developed embryos ready to pass out could be seen in single file in the lumen of the vagina near the opening (fig. 22). Railliet and Henry (191 Ib) describe the vulva as opening posteriorly at the limit of the third and four fifths of the body. Von Linstow (in litt) places it somewhat posterior of the middle of the body, dividing the worm in the ratio of 10 to 9. The arrangement of the uteri and ovaries in the body of the female is, so far as could be seen, similar to that of Arduenna strongylina. The convoluted ovary of the posterior uterus occupies the caudal extremity of the worm, its terminus disappearing dorsal of the posterior uterus. A loop of the anterior uterus extends nearly to the caudal end. The exact length of the vagina was not determined. A loop of the posterior uterus, corresponding to the loop of the anterior uterus, lies underneath the anterior uterus and extends nearly to its terminus. The union of the vagina with the uteri was not seen, nor was the anterior ovary traced throughout its length. While neither uterus was followed throughout its entire length, the two termini, one posterior the other anterior, the posterior uterine loop, and the anterior loop, are all similar to the arrangement seen more clearly in Arduenna strongylina. Ciurea (1912) depicts a pluglike protuberance at one of the poles of the eggs of Physocephalus sexalatus, which bears a superficial resemblance to the operculum of a Trichuris egg, but does not penetrate the eggshell as in the latter case. This feature was not seen by the present writer; however, a faint transverse line could be seen at either pole (fig. 23), which apparently is the line of fissure along which the shell breaks when the embryo is liberated. STRONGYLINA. The following comparison of appearances of Arduenna strongylina and Physocephalus sexalatus will assist in separating the two species without the aid of a magnifier. Males. — Tail of Physocephalus sexalatus ending in a spiral, Arduenna strongylina ending in a single coil; PJiysocephalus sexalatus shorter and slenderer than Arduenna strongylina. Females. — PJiysocephalus sexalatus straight, or nearly so; specimens preserved in alcohol when lifted out of a petri dish with a needle bend sharply in the middle. Body slenderer than Arduenna strongylina, except toward the posterior end, which is thicker and blunter. Alcohol specimens of Arduenna strongylina are usually curved in a half circle. They are thicker in the middle of the body than Physocephalus sexalatus and pointed at both ends. On being lifted with a needle they do not collapse like PJiysocephalus sexalatus, but maintain their crescentic shape. As has already been stated, Molin (1860b) was the first to distinguish this species from Arduenna strongylina, with which it had been confused by Diesing (185 la). Besides the specimens from the whitelipped peccary, Molin (1860b) also found two females of this species in a bottle containing specimens of Arduenna strongylina collected by Bremser from the stomach of the wild boar and deposited in the Vienna Museum. That it has only twice been reported in Europe in association with Arduenna strongylina is perhaps due to confusion of the two species, an error which appears to have occurred in at least one case (Von Linstow, 1879b). In the United States it has been found in nearly every case in which specimens of Arduenna strongylina have been collected. OTHER SPECIES REFERRED TO PHYSOCEPHALUS SEXALATUS. Two other worms have been thought by different writers to be possibly identical with Physocephalus sexalatus, viz, Simondsia paradoxa (Cobbold, 1864b) from Sus scrofa domestica and Filaria nitidulans (Schneider, 1866a) from Tapirus americanus. Simondsia paradoxa was collected from the stomach of a German hog kept at Regent's Park, London, and was described by Cobbold (1864b). In a later work (1879b) Cobbold suggests the possibility of the worm being identical with Physocephalus sexalatus. The immensely hypertrophied uterus of Simondsia paradoxa, forming a rosette entirely covering the caudal end of the female, however, clearly differentiates this species from Physocephalus sexalatus. In his description of Physocephalus, Von Drasche (1884a) suggests the possibility that Schneider's (1866a) Filaria nitidulans may be identical with P. sexalatus. Both worms are characterized by three lateral wings on either side, and the caudal extremity of the males of both species are alike in the number and arrangement of the papillae. The measurements of Filaria nitidulans (males 20 mm., females 32 mm.) are, however, far in excess of the measurements for Physocephalus sexalatus, and the position of the vulva of Filaria nitidulans is stated as "directly above the anus," while the vulva of Physocephalus sexalatus is slightly posterior of the middle of the body. Ciurea (1912), who has recently reexamined Schneider's material, was unable to determine the location of the vulva of F. nitidulans. He gives, however, a summary of the differences between Filaria nitidulans and Physocephalus sexalatus, proving conclusively that they belong to different species, although he considers that Filaria nitidulans should be included in the genus Physocephalus. Stossich (1897b), following Von Drasche's (1884a) suggestion, considered the worms identical. He listed Tapirus americanus as a host of Physocephalus sexalatus and combined Molin's (1860b) measurements of P. sexalatus with Schneider's (1866a) measurements of Filaria. nitidulans. LUS SEXALATUS IN THE UNITED STATES. Of nine lots of Arduenna strongylina collected in various parts of the United States and now deposited in the helminthological collection of the Bureau of Animal Industry, only two have been found not to contain examples of Physocephalus sexalatus, and both of these lots contain only a few specimens. The distribution of Arduenna strongylina is therefore similar to that of Physocephalus sexalatus, since the latter species, according to the writer's experience, is practically always associated with the former. To determine the distribution of these parasites and the frequency of their occurrence in the United States the literature was searched for references to Spiroptera strongylina. Four such references were found, as below; in most cases Physocephalus sexalatus was probably also present but not recognized. 1. Curtice (1892g), in a list of parasites infesting domestic animals and man in the United States, includes the following entry : "Spiroptera strongylina. Hud. Host, Sus scrofa domestica. Location, stomach," followed by the remark, "Is often found with the food and attached to the walls." Specimens No. 2058 of the helminthological collection of the Bureau of Animal Industry were collected and identified by Curtice as Spiroptera strongylina. These specimens have been examined by the writer, who verified Dr. Curtice's identification. A few examples of Physocephalus sexalatus were also present. 2. Stiles and Hassall (1894e) include Spiroptera strongylina in their preliminary catalogue of the parasites in the collection of the United States Bureau of Animal Industry. They report the parasite as common. The specimens referred to by them (No. 2057 of the bureau collection) have been reexamined by the writer, and many specimens of Physocephalus sexalatus were found with the specimens of Arduenna strongylina. Stiles and Hassall's specimens were collected at Benning, D. C. 3. Francis (1894a) reported Spiroptera strongylina in a list of parasites collected by him in Brazos County, Tex. It is reported as common. The specific name is followed by an interrogation point in parenthesis to indicate the author's doubt as to the correctness of the identification. Considering the inaccuracy of the descriptions of Arduenna strongylina, then available, it is not to be wondered that Francis, noticing the discrepancies between the descriptions and the anatomical features seen in his specimens, should question the identification. On the other hand, it is quite possible that the specimens collected by Francis were Physocephalus sexalatus, or included this species. 4. Kaupp (1910) reported the occurrence of Spiroptera strongylina in hogs raised in the Missouri Valley. His article is illustrated with original drawings, one of which shows the caudal end of the female with the vulva apparently on the right side, a little anterior of the anus. For the sake of additional data, letters were sent to the inspectors in charge at some of the principal slaughterhouses of the United States, requesting information in regard to the occurrence of Spiroptera strongylina in hogs. Replies were received from South Omaha, Chicago, St. Louis, and Kansas City. The inspector in charge at South Omaha reported that fully 80 per cent of the hogs examined were infested. It was reported from St. Louis that "the worms occur in considerable numbers in the mucous coating of the stomach." The parasite is reported as very frequent in hogs slaughtered at Kansas City; out of 1,450 hogs examined, 1,052 were infested. In some stomachs as many as 140 worms were collected. From Chicago it was reported that 1,000 hogs had recently been examined, and 690 were found infested. The worms were found on the surface of the mucous membrane or attached by the head. Several hundred specimens obtained by scraping the mucosa from the stomachs of a number of infested hogs were received from this city. These worms were found to be Arduenna strongylina and Physocephalus sexalatus. Reports from slaughterhouses regarding the occurrence of parasites are of but little value in determining the localities infested by a given parasite, as the animals slaughtered are received from widely scattered sections of the country. Enough data have been gathered, however, to warrant the assertion that the parasites occur throughout the middle and southwestern (and probably eastern) United States. Specimens have been collected by Hall in 1908 from a hog kept at Bethesda, Md., in all probability of eastern origin. They have also been collected by Kilborne at Washington, D. C., and by Stiles and Hassall at Benning, D. C. ; in the latter case, however, it is possible that the host animal had been shipped to the local slaughterhouse from a Western or Central State. strongylina in American swine is indicated by the following data : All the worms contained in a bottle of specimens forwarded from Chicago were sorted out by species and sex. The bottle contained 744 specimens. Of these, 599, or approximately 80 per cent, were Arduenna strongylina, and the remaining 145, or 20 per cent, were Physocephalus sexalatus. Of the 599 specimens of Arduenna strongylina, 399, or 56 per cent, were females, and 260, or 44 per cent, were males. A smaller percentage of males was found among the specimens of Physocephalus sexalatus. Of the 145 specimens found, 69 per cent were females and 31 per cent were males. NA DENTATA, AND PHYSOCEPHALUS SEXALATUS. From an economic standpoint these three species are^probably of considerable importance. Prior to 1899 it was not considered that Arduenna strongylina was especially injurious to swine. Neumann (1892a), in mentioning that Spiroptera strongylina caused small submucous tumors of the stomach and that no morbid disturbances were attributed to it, summed up the general opinion of the time regarding the economic importance of the parasite. More recent reports, however, indicate that these parasites should be regarded as the possible etiology of serious gastric disorders. Von Ratz (1899d) found Spiroptera strongylina very common among swine hi Hungary, and attributed to this parasite several epizootics of a rather serious nature, in one of which, out of a herd of 230 sows, 21 were seriously affected and 6 died. Some of the symptoms were described as follows: The diseased sows suffered from loss of appetite, eating very little and in the worst cases finally refusing all food; on the other hand, they drank water excessively and were very restless, continually pawing the ground. At the pyloric end the mucous membrane was covered with a thick, lamellous, firmly adhering pseudomembrane, which upon being removed revealed a superficial loss of tissue of the mucous membrane. Under the mucous membrane lay numerous Spiroptera strongylina fastened partly in the stomach wall, partly in the pseudomembrane. In addition to these lesions, dark red spots the size of a penny were to be seen, corresponding to which were numerous openings the size of a needle prick, through which projected the bodies of the nematodes. While no data are at hand regarding the effect of Arduenna dentata on its host, hi view of its close similarity with Arduenna strongylina and the fact that both species are parasitic in the stomach, it may be assumed that the former species is as injurious as the latter. Railliet and Henry (19 lib) report that the stomach of a sow from Madagascar from which specimens of PJiysocephalus were collected, presented a very intense gastritis with a quantity of small elevations on the mucosa. The information and material supplied by the inspectors of this bureau have shown that lesions of a nature similar to those described by Von Ratz are frequently associated with the presence of Arduenna strongylina in this country. The inspector in charge at South Omaha reported that "Ten per cent of the affected stomachs show a highly inflamed zone surrounding the infested area, and hi a few instances considerable ulceration exists." The inspector in charge at St. Louis was of the opinion that "they produce no apparent lesions." The inspector in charge at Chicago forwarded, in addition to the loose specimens already mentioned, several pieces of hogs' stomachs showing the worms in situ. The heaviest infestations were found hi portions from the pyloric end of the stomach, which in one instance presented the folio whig appearances: A piece of stomach from the pyloric end about 21 cm. wide by 20 cm. long contained a cluster of worms buried in a glairy mucous mass of yellowish color firmly attached to the normal mucous membrane, and forming, hi the opinion of pathologists in the Pathological Division of this bureau, to whom the tissues were referred, a pseudomembrane of necrotic tissue. Several such worm clusters were observed on the portion examined, the worms in nearly every case being buried in a mass of mucus, and appearing as bright red lines in the yellowish mass. (See PI. I.) In places the necrotic tissue had apparently sloughed off, leaving deep, red, depressed areas of irregular shape. These areas varied in size from a few millimeters to 2 or 3 centimeters in diameter. The same lesions could be observed under the necrotic tissue when this had been removed with forceps. The condition was described by one of the pathologists as "undoubt edly ulcerous." It was suggested by the pathologists who examined the material that the pseudomembranes might have been caused by Bacillus necrophorus gaining an entrance to the submucosa as the result of the piercing of the mucous membrane by the parasitic worms; examinations of scrapings from the stomach lesions revealed a few specimens of the bacillus. As explained by Mohler and Morse (1904), this bacillus is normally found in the stomachs of hogs and other animals, and while under ordinary circumstances it has no pathological effect, if enabled through some lesion to the mucous membrane to gain access to impaired tissue, its proliferation results in the sloughing of the mucous membrane and the formation of ulcers. Mohler and Morse (1904), describing necrobacillosis of the digestive tract, state: "The necropsy in such cases revealed hemorrhages and erosions in the stomach, but no areas of coagulation, ' ' an accurate description of the conditions found by the present writer. The characteristic odor described for lesions of Bacillus necrophorus was only faintly present, being modified perhaps by the boric acid with which the specimen was sprinkled and which may account for the paucity of the parasitic flora found. How deeply Arduenna strongylina is capable of penetrating into the submucosa was well shown in one of the specimens forwarded from Chicago. A piece of the cardiac portion of the stomach contained a worm 12 mm. long which had bored diagonally into the mucosa to a depth of 10 mm., only the caudal end projecting above the "surf ace. The hole made was similar to a pin prick, a simile used by Von Ratz (1899d) in describing the lesions observed by him. Indeed Von Ratz's description is practically identical with the conditions found by the present writer. The habit of boring into the mucosa characteristic of these parasites would seem an ideal method of inoculating the submucosa of the host with Bacillus necrophorus if any were present, and this, considered in connection with the conditions observed in infested stomachs, indicates that the worms may be the indirect cause of grave ulceration. Considered apart from their possible r61e as infective agents, the mechanical injury to the stomach walls due to the penetration of the worms in numbers would seem to be a serious factor even if the worms were unassociated with bacilli. Moreover, the livid red color of the worms in situ in the stomachs examined would seem to indicate that they feed on blood, an additional reason for regarding them as dangerous parasites. The whole question, however, of the pathogenicity of the parasites, and as to their relationship to the lesions observed, remains open for further investigation. An examination of the stomach portions received showed specimens of Physocephalus sexalatus attached in the same manner as already noted for Arduenna strongylina; hence the former parasite may be considered only less dangerous than the latter, as it is less abundant. LIFE HISTORY. Nothing is known in regard to the development of the worms from the egg to the adult. The wide distribution, the frequency of the parasites, and the similarity of the eggshell to that of an ascarid, suggest the possibility that development occurs without an intermediate host. From the fact that the embryos are well developed in the uterus before oviposition, it would seem that but little time is required for incubation, and the thickness of the shell would indicate the necessity of the gastric juice of the host to dissolve the shell and liberate the embryo. PREVENTIVE MEASURES. In the absence of knowledge as to the life cycle of the parasites, no prophylaxis or treatment specially adapted to the case can be formulated. The following general prophylactic measures are suggested: 1. Hogs suffering from loss of appetite or failing to fatten under proper food and hygiene should be examined for evidence of infection by killing one or two and looking in the stomach for worms; or, where practicable, the feces of the entire herd may be examined microscopically. 2. Those swine found infested with stomach worms should be isolated from noninfested or presumably noninfested swine in clean pens, and the dung removed daily and mixed with quicklime or disposed of by carting it to places to which hogs do not have access. 3. The noninfested swine should not be allowed to remain in the same pens formerly occupied by the infested animals, but should have clean quarters. The old pens should be thoroughly disinfected with lime after removing the dung and burning over the ground where feasible. MEDICINAL TREATMENT. Youatt (1847c), referring to Spiroptera strongylina, recommends turpentine and salt with the food for treating these worms. Coal-tar creosote, gasoline, and copper sulphate have been found more or less efficacious in treating stomach worms (Hsemonchus contortus) in sheep, and similar treatment might be tried on pigs (see Bureau of Animal Industry Circular 102). Santonin and calomel, 3 grains each per hundred pounds of body weight, given after a fast of 12 to 16 hours, is another remedy which deserves trial. Whatever drug is used should first be given in small quantities and tried on a few of the most heavily infested swine, the size of the dose being increased as occasion demands. The arrangement of the following key to the roundworms which have been reported by various authors as parasites of hogs is purely artificial and arbitrary and indicates nothing as to the systematic relationship of the different forms. A classified list of the roundworms of swine is given later on page 41. 2. Anterior extremity furnished with a protractile prolwscis covered with spines. Male 6 to 10 cm. long, 3 to 5 mm. in diameter. Female 20 to 35 cm. long, 4 to 9 mm. in diameter. Eggs, 87 to 100 n long, subcylindrical, smooth, with 3 envelopes. In small intestine, usually attached to the mucous membrane Gigantorhynchus hirudinareus. Anterior extremity without protractile proboscis. Mouth with 3 prominent lips. Male 15 to 17 cm. long, 3 to 3.2 mm. thick. Female 20 to 25 cm. long, 5 to 5.5 mm. thick. Eggs oval, 66 fi long, thick-shelled, surface covered with mammillate projections. In small intestine, sometimes in biliary tract and pancreas Ascaris suum. small intestine, larvae encysted in skeletal muscles Trichinella spiralis. Vulva posterior of middle of body. Females (parthenogenetic; parasitic males lacking) 3.75 mm. long, 80 fi in diameter. Eggs 45 fi long by 25 /t broad, with thin shells. In small intestine Slrongyloides suis.1 7. Anterior portion of body slender, like a whiplash, about twice as long as the thicker posterior portion. Male with single spicule. Male 33 to 40 mm. long. Female 34 to 50 mm. long. Eggs 52 to 56 /* long, ellipsoidal, with an opening at each pole closed by a plug-like operculum, and brownish in Body continuous, not flagelliform anteriorly. Male with two spicules 8 1 While Strongyloides papillosvs («= Trichosoma papiUosum Wedl.)a parasite of sheep has frequently been reported for the pig, this is probably the result of confusion with Strongyloidu suis. The Stronyyloides of the pig Is somewhat larger than the form found in sheep. 10. Buccal capsule broader than long, mouth bordered by a crown of numerous, small, pointed processes. Male 8 to 12 mm. long. Female 12 to 15 mm. long. Spicules slender, 1.13 mm. long. Adults in large intestine, larvae encysted in the wall of the large and small intestines, forming nodules. .(Eesophagostomum dentatum. Buccal capsule spherical or elongated , border of mouth smooth 12 Globocephalus longemucronatus. Buccal capsule elongated, oval. Male 4.4 mm. long, 0.38mm. thick. Female 6.5 mm. long, 0.52 mm. thick. Spicules 590 /t long. Vulva sunken. In small intestine Crassisoma urosubulatum. 300 to 350 fjL thick. Left spicule 16 to 17 mm. long; right spicule 140 to 180 fj. long. Vulva 4 to 5 mm. from tip of the tail. Eggs 55 to 60 ft long by 32 to 36 [i wide. In the mucosa of the esophagus and pharynx. Gongylonema scutatum.2 Male 14 to 50 mm. long, 175 to 195 fj. thick. Female 37 to 40 mm. long (? or longer), 350 n thick. Left spicule 4 to 5 mm. long, right spicule 84 to 110 fj. long. Vulva about 2 mm. from the tip of the tail. Eggs 52 to 56 ,« long by 32 fj. wide. In the mucosa of the esophagus and pharynx. 14. Body furnished anteriorly with six longitudinal lateral wings, three on each side, the middle wing of each three wider than the other two. Ridges of pharynx forming a simple spiral, breaking up into separate wings. Male 6 to 9 mm. long. Female 13 to 19 mm. long. Spicules 2.1 to 2.25 mm . long, and 300 to 350 /t long, respectively. Vulva anterior of the middle of the body. Eggs 34 u. long by 15 ,« wide, with rather thick shells. In stomach. Trichostrongylinse. As yet, however, no genus has been established to which it may be assigned. * Reported by Korzil (1877a) and Piana (1896b). According to Neumann (1894d), however, the measurements given by Korzil indicate that the species studied by him is Gongylonema pulchrum, Molin 1857. The measurements given by Piana(1896b) are, males 60 to 80 mm. long by 130 ft broad; females 80 to 145mm. long, 600 n broad. Except that G. pulchrum is smaller than G. scutatum, there is but little morphological difference between the two species. The species are considered identical by Railliet (1893a), although this view is not accepted by Neumann (1894d) and others. G. scutatum is normally a parasite of ruminants. Section. 15. Male 10 to 15 mm. long. Female 16 to 22 mm. long. Long spicule 2.24 U> 2.95 mm. in length, 5 to 6 times as long as the short spicule. Vulva somewhat anterior of the middle of the body. Eggs 34 to 39 p long by 20 ft wide, with rather thick shells. In stomach Arduenna strongylina. Male 25 to 35 mm. long, 700 to 800 /j. broad. Female 40 to 55 mm. long, 1.1 to 1.2 mm. broad. Long spicule 3.75 to 4.23 mm. long. Short spicule 540 to 650 ft long. Vulva three-eighths of the distance from the anterior end. 16. l Spicules about 4 mm. long, each terminated by a single hook. Vagina about 2 mm. long. Male between 12 and 25 mm. in length. Female between 20 and 50 mm. in length. Vulva near anus. Eggs between 57 and 100 /t in length and 39 and 73 ft. in width. In trachea and bronchi.. Atetastrongylus apri. Spicules 1.5 mm. long, each terminated by a double hook. Vagina about 500 [i Jong. Male between 12 and 25 mm. in length. Female between 20 and 50 mm. in length. Vulva near anus. Eggs between 57 and 100 fi in length and 39 and 72 fi in width. In trachea and bronchi. 19. Male 25 to 37 mm. long. Female 37 to 40 mm. long. Two spicules, equal or subequal, about 0.8 mm. long. Vulva less than 2 mm. from the tip of the tail. Eggs 100 fi long by 56 fi wide, with thin 'shells. In kidneys, ureters, and encysted in fat of kidneys and loins Stephanurus dentatus. 20. Male 14 to 40 cm. long, 4 to 6 mm. in diameter. Female 20 cm. to 1 m. long, 5 to 12 mm. in diameter. Spicule single, 5 to 6 mm. long. Vulva near the anterior end of the body. Eggs 64 to 68 ft long by 40 to 44 ft wide, thickshelled, with pitted surface. In kidneys, ureters, peritoneal cavity, or bladder Dioctophyme visceralis.3 Male 10 to 11 cm. Greatest diameter, 650 fi. Tail twisted in a loose spiral with a pointed end; 8 pairs of papillae, 4 preanal and 4 postanal. Spicules unequal, the longer 215 ft long, 25 fi broad, with a membraneous extension 70 fi long. Short spicule 140 fi long, 52 ft broad. Female 20 to 21 cm. long. Vulva 600 fi from the anterior extremity. Anus 300 fi from the posterior extremity. Eggs ovoid, 45 by 26 ft when fully developed. Viviparous. Parasitic in the peritoneal cavity Setaria bernardi. 1 Railliet and Henry, 1911, describe a new species, Filaria bauchei, found in the "lungs "of a hog slaughtered at Hud, Indo-China. The location of the parasite is not definitely known. The female alone was found. It is reported as 22J cm. long, with a maximum diameter of 635 ft. The body is transversely striated, the striae being 5 to 6 /» apart. Mouth unarmed, funnel-shaped, the cuticle thickened at the anterior end. Anus 155 p. from the posterior extremity; vulva 1. 1 mm. from the mouth. SWINE. Specific descriptions are omitted from the following list as these have already been given in the key to the roundworms of swine. Arranged according to their respecive orders, families, and genera, the roundworms reported as parasitic in domestic swine are as follows: chain. Generally dioecious. Order Nematoda. Nemathelminthes: Provided with a complete digestive tube. Family Angiostomidae. Nematoda: Having two heterogenetic generations, one of free-living males and females and one of hermaphroditic or parthenogenetic forms which are parasitic. Genus Strongyloides. Angiostomidse : Parasitic form with mouth opening directly into the relatively very long subcylindrical esophagus. Vulva posterior of the middle of the body. Uterus double. Two ovaries. Free-living form with mouth opening into a vestibule or pharynx, followed by an esophagus whose anterior portion is fusiform and posterior portion globular. Strongyloides suis. Family Gnathostomidae. Nematoda: Body furnished throughout its length, or only anteriorly, with chitinous blades or wings, serrated posteriorly. Head subglobular, covered with simple spines. Genus Gnathostoma: With the characteristics of the family. Gnathosloma hispidum. Family Trichinellidae. Nematoda: Esophagus consisting of a chain of single cells, the lumen of the esophagus passing through the center of each cell. Anterior portion of body containing the esophagus usually very slender; posterior portion containing the intestine and reproductive organs more or less swollen. One testicle, one ovary. Subfamily Trichinellinse. Trichinellidae : Male without spicule. Female ovo viviparous. Adulte in intestine of host produce larvae which penetrate into the muscles, become encysted, and develop to maturity when the flesh of this animal is eaten by another animal. Genus Trichinella. Trichinellinse : Very small worms with capillary bodies. Progressively increasing in diameter posteriorly. Male with two conical posterior appendages forming a copulatory bursa. Vulva of the female in the anterior fifth part of the body. Trichinella spiralis. Subfamily Trichurinse. Trichinellidae: Male with spicule. Female deposits eggs characterized by the presence of an opening at each pole closed by a pluglike operculum. Egga do not hatch until swallowed by a suitable host. Development, so far as is known, direct, without an intermediate host. Genus Trichuris. Trichurinae: Anterior portion of body very long and slender. Posterior portion of body containing the intestine and reproductive organs relatively thick and much shorter than the anterior portion. Posterior portion of male rolled dorsally into a spiral. Spicule surrounded by a prepuce-like sheath. Posterior portion of body of female slightly curved. Vulva near the beginning of the posterior portion of body Trichuris suis. Family Filariidte. Nematoda: Body long, filiform. Mouth surrounded with papillae, or provided with two lips. Esophagus slender, without posterior bulb. Males with two unequal spicules (sometimes with a single spicule). Females with two ovaries. Vulva usually anterior of the middle of the body. Development often requires an intermediate host. Genus Filaria. Filariidae: Body long and slender, of nearly uniform diameter throughout; males considerably smaller than the females, with the tail hooked or curved in a spiral, sometimes furnished with lateral wings. Usually there are four preanal and a variable number of postanal papillae. Spicules usually very different in shape and dimensions. Vulva more or less near the mouth. Genus Setaria. Filariidae: Head armed with a projecting peribuccal circle, deeply notched laterally, somewhat less indented dorso-ventrally, giving the impression of two teeth when seen laterally and of four teeth when seen at an angle. Tail of both sexes provided with two special appendices Setaria bernardi. Genus Gongylonema. Filariidae: Body filiform, slightly attenuated at either end. Anterior portion of body covered with numerous tubercles or shields formed by differentiation of the cuticle. In the median lines immediately behind the mouth, two semilunar depressions, one dorsal, the other ventral. Tail of male curved ventrally, supplied with two asymmetrical membranous wings. Vulva a short distance anterior of the anus. .Gongylonema scutatum. 3 Subfamily Arduenninae. Filariidse:3 Mouth with two lateral lips leading into a pharynx marked with cuticular ridges in the form of spirals or rings. Spicules unequal, the longer several times the length of the shorter. Four pairs of preanal papillae. Eggs containing embryos at the moment of ovi position. Genus Arduenna. Arduenninae: Mouth leading into a cylindrical pharynx marked by ridges, forming a continuous multiple spiral. Esophagus continuous, nearly one- third of the length of the body. Spicules very long and very unequal. Tail twisted in a single coil. Bursa asymmetrical, supported by five pairs of papillae. Arduenna dentata. Genus Physocephalus. Arduenninae: Body furnished anteriorly with six lateral wings arranged in a group of three wings each, on either side. The middle wing of each group is the widest. Pharynx cylindrical, relatively broad and long, marked with a simple spiral ridge on the inside, breaking up into separate rings and resuming the spiral at the posterior end Physocephalus sexalatus. Genus Simondsia.4 Filariidae: Female characterized by a tegumentary excrescence in the form of a rosette situated in the posterior part of the body and inclosing a prolongation of the intestine and a hypertrophied uterus Simondsia paradoxa. « Railliet and Henry (1911b) include Simondsia In the subfamily Arduenninne, although Piana (1897e) describes the lips as dorso-ventral rather than lateral. In the structure of the esophagus, the number of preanal papillae, and the inequality of the spicules Simondsia conforms to the description of the subfamily Arduenninse. Family Strongylidae. Nematoda: Head with eix more or less distinct circumoral papillae. Males with a more or less well-developed bursa, each lateral lobe of which is usually supplied with six supporting rays. Spicules equal or subequal. Vulva may be anterior to the middle of the body, but is usually posterior. Oviparous. Development, so far as known, direct without intermediate host. Subfamily Strongylinae. Strongylidse: Buccal capsule well developed. Eggs in the process of segmentation at the moment of oviposition. Embryo nearly always rhabditiform and development direct. Parasitic in the alimentary canal; exceptionally in the respiratory system. Genus (Esophagostomum. Strongylinae : Head 75 p or more in diameter; buccal capsule small. Cuticle surrounding the mouth usually inflated to form a ringlike mouth collar. Bursa of male with two lateral lobes united by a smaller median lobe. Spicules more than 0.5mm. long, slender, tubular, pointed ; gubernaculum present, but not conspicuous (Esophagostomum dentatum. Genus Globocephalus. Strongylinse: Buccal capsule cylindrical, larger in diameter than the thickness of the body, supported by two chitinous rings— one at the anterior end of the capsule, the other at the posterior end. The rings are joined by four chitinous longitudinal bands Globocephalus longemucronatus. Genus Crassisoma. Strongylinse: Buccal capsule oval, smaller in diameter than the thickness of the body, supported by eight longitudinal thickenings of the cuticle, and a chitinous ring on the inside of the capsule Crassisoma urosubulatum. Subfamily Trichostrongylinse. Strongylidae : Buccal capsule absent or slightly developed. Eggs generally segmenting at the time of oviposition. Embryo rhabditiform and development direct. Parasitic in the alimentary canal. Subfamily Metastrongylinse. Strongylidse : Buccal capsule absent or slightly developed. Eggs in various stages when oviposited. Embryo rhabditiform. Evolution unknown, perhaps requiring an intermediate host. Parasites of the respiratory or circulatory system. Genus Metastrongylus. Metastrongylinae: Mouth with six lips. Postero-lateral ray much reduced or absent. Dorsal ray and externo-dorsal rays slender, the others thick. Two very long spicules. Vulva close to the anus. Eggs with well-developed embryos. Parasitic in the bronchi and trachea. bubfamily not determined. Genus Stephanurus. Strongylidae: Anterior extremity truncated; mouth suborbicular, limited by a chitinous ring furnished with teeth. Caudal bursa of male with many lobes. Genus Dioctophyme. Nematoda: Body cylindrical, mouth without lips, surrounded by papillae. Male furnished with a filiform spicule. Female with a single ovary. Vulva in the anterior part Family Ascaridae. Nematoda: One lip median, dorsal; two submedian, ventral. Relatively thick forms. Males provided with two spicules. Females with double ovary. Genus Ascaris. Ascaridae: Furnished with three strong lips, the lateral sides of which are generally toothed. Males with two equal or subequal spicules and numerous papillae anterior and posterior of the anus. Vulva located anterior of the middle of the body. Eggs globular or ellipsoidal, usually surrounded by an albuminous envelope. In process of segmentation at the time of ovi- Order Acanthocephala. Nemathelminthes without mouth or digestive tube. Furnished with a protractile proboscis armed with hooks. Family Gigantorhynchidae. Acanthocephala: Body large and annulated; taeniaform. Hooks of the proboscis with two roots and covered with a transparent layer of chitin. Lemnisci lengthened into the form of rounded bags and having a central canal. Genus Gigantorhynchus; with the characteristics of the family. i Dioctophyme visceralis although commonly included in the family Strongylidse does not conform to all the characteristics of this family. It more closely resembles the Filariidae as pointed out by Raillet and Henry (1909a). Probably it should be placed in a family by itself, but the question is open to further study. DIESING, KARL MORITZ. 1851a. — Systema helminthum. v. 2, vi-f 588 pp., 2 1. 8°. Vindobonse. 1861a.— Revision der Nematoden. <Sitzungsb. d. k. Akad. d. Wissensch., Wien, Math.-naturw. Cl. (1860), v. 42 (28), 6 Dec., pp. 595-736, 1 pi., figs. VON DRASCHE, RICHARP. 1884a. — Revision der in der Nematoden-Sammlung des k. k. zoologischen Hofcabinetes befindlichen Original-Examplare Diesing's und Molin's. <Verhandl. d. k. k. zool.-bot. Gesellsch. in Wien (1883), v. 33, pp. 193-218, pla. 11-14. GURLT, ERNST FRIEDRICH. 1831a. — Lehrbuch der pathologischen Anatomic der Haus-Saugethiere. Nebst einen Anhange, welcher die Beschreibung der bei den Haus-Saugethieren vorkomenden Eingeweidewurmer enthalt. v. 1, xx-f 399 pp. 8». Berlin. MUELLER, OTTO ERIEDRICH. 1787a. — Verzeichniss der bisher entdeckten Eingeweidewurmer, der Thiere. in welchen sie gefunden woolen, und besten Schriften, die derselben erwahnen <Naturforscher, Halle, v. 22, pp. 33-86. 1897e. — Ricerche sulla morfologia della Simondsia paradoxa Cobbold e di alcuni altri nematodi parassiti dello stomaco degli animali della specie Sus scrofa L. <Atti. Soc. ital di sc. nat. [etc.], Milano, v. 37 (1), giugno. pp. 17-37, figs. 1-7. 18?vt!'n,iPHeilmfinaif ca<alofUAe ?f ^^r Pf^1^ contained in the collections of the United States Bureau of Animal Industry, U. S. Army Mod. Museum, Biological Dept. of the University of Pennsylvania (Coll. Leidy) and Coll. Stiles ZUERN, FRIEDRICH ANTON. 1882a.-Die Schmarotzer auf und in dem Korper unserer Haussaugethiere, sowie ^T^ere veranlassten Krankheiten, deren Behandlung und Verhiitung ITheil: Tierische Parasiten. 2 Aufl., xvi+316 pp., 4 pis 8° Weimar ADDITIONAL COPIES of this publication -LI- may be procured from the SUPERINTENDENT OF DOCUMENTS, Government Printing Office, "Washington, D. C., at 10 cents per copy	18,044	common-pile/pre_1929_books_filtered	roundwormsof00fostiala	public_library	public_library_1929_dolma-0013.json.gz:4556	https://archive.org/download/roundwormsof00fostiala/roundwormsof00fostiala_djvu.txt
V481yltqMKffiks8	My Scheeßel Relatives - Vol 2	(6610)RAHMSTORF (RAHNSTORP) + NoName – Parents of RAHMSTORF (RAHNSTORP), Harm (6612) When NoName Rahmstorf was born in 1580, his father, Harm, was 32 and his mother, Anneke, was 30. He was baptized in 1580. He was baptized in 1580. He married Ms. NoName in 1605. They had three children during their marriage. The Gen_Pluswin OFB Sittensen Database has the following entry: Translation 6610 RAHMSTORF, (NoName) (Lutheran) – Parents:. R., Harm and WICHERN, Anneke (6611.1) Born in 1580 (estimated) in Stemmen (KSPL Scheeßel). Christened in 1580 (estimated) in Scheeßel. Occupation: Halbhöfner in Stemmen (KSPL Scheeßel). Farm name / number :: Rahnstorp, No. 1 Stemmen. Died in Stemmen (KSPL Scheeßel). Buried in Scheeßel. Church Marriage1605 (estimated) Children: 1. Anna (Lutheran) Born in 1606 (estimated) in Stemmen (KSPL Scheeßel). Christened in 1606 (estimated) in Scheeßel. Died after 1675 in Stemmen (KSPL Scheeßel). Buried after 1675 in Scheeßel. 2. Hinrich (Lutheran) Born in 1608 (estimated) in Stemmen (KSPL Scheeßel). Christened in 1608 (estimated) in Scheeßel. Died in Vahlde. Buried in Scheeßel. 3. Harm (RAHNSTORP) (Lutheran) Born in 1615 (estimated) in Stemmen (KSPL Scheeßel). Christened in 1615 (estimated) in Scheeßel. Occupation: Vollhöfner in Hunhorn. Farm name / number :: Hunhorn, single-digit Hof. Died 1680 (estimated) in Hunhorn. Buried 1680 (estimated) in Scheeßel. Marriage with Margreta FICKEN (6612)	275	common-pile/pressbooks_filtered	https://pressbooks.pub/mycheesselrelatives/chapter/generation-10-noname-rahmstorf-and-noname/	pressbooks	pressbooks-0000.json.gz:24758	https://pressbooks.pub/mycheesselrelatives/chapter/generation-10-noname-rahmstorf-and-noname/
T8Jf6yLtyaouTV2w	Special order providing for the importation of Canadian sheep for exhibition purposes at the Alaska-Yukon-Pacific exposition, Seattle, Wash.. / U.S. Dept. of Agriculture, Bureau of Animal Industry.	BUREAU OF ANIMAL INDUSTRY. SPECIAL ORDER PROVIDING FOR THE IMPORTATION OF CANADIAN SHEEP FOR EXHIBITION PURPOSES AT THE ALASKA-YUKONPACIFIC EXPOSITION, SEATTLE, WASH. It is hereby ordered, That from May 20 to October 10, 1909, Canadian sheep may be imported into the United States for exhibition purposes at the Alaska- Yukon-Pacific Exposition, to be held at Seattle, Wash., from June 1 to October 15, 1909. without being subject to the thirty days quarantine, provided they pass a satisfactory inspection at the port of entry and are accompanied by an affidavit of the owner or importer, and a certificate issued by a Canadian official veterinarian, as required by Amendment 3 to B. A. I. Order 142. amending Regulation 41 of the Regulations for the Inspection and Quarantine of Horses, Cattle, Sheep, and other Ruminants, and Swine Imported into the United States; and provided further that the sheep which are not sold to remain in the United States shall be returned immediately to Canada at the close of said exposition. The Department must be notified by the owner or importer, through the ofrice of its veterinary inspector in charge at Seattle, of any Canadian sheep which are to remain in the United States for breeding purposes, and such sheep will be maintained in quarantine at the exposition grounds under the supervision of an inspector of this Department, who shall issue a certificate before shipment to a destination is allowed.	317	common-pile/pre_1929_books_filtered	speorde09unit	public_library	public_library_1929_dolma-0007.json.gz:5020	https://archive.org/download/speorde09unit/speorde09unit_djvu.txt
Pks3BUtDIdYG_odP	Child and Adolescent Developmental Psychology	54 After reading this chapter, you should be able to: - Compare and contrast Piaget and Vygotsky’s beliefs about cognitive development. - Explain the role of information processing in cognitive development. - Discuss how preschool-aged children understand their worlds. - Put cognitive and language milestones into the order in which they appear in typically developing children. - Discuss how early child education supports development and how our understanding of development influence education. - Describe autism spectrum disorder, including characteristics and possible interventions.[1] Early childhood is a time of pretending, blending fact and fiction, and learning to think of the world using language. As young children move away from needing to touch, feel, and hear about the world toward learning some basic principles about how the world works, they hold some pretty interesting initial ideas. For example, while adults have no concerns with taking a bath, a child of three might genuinely worry about being sucked down the drain. A child might protest if told that something will happen “tomorrow” but be willing to accept an explanation that an event will occur “today after we sleep.” Or the young child may ask, “How long are we staying? From here to here?” while pointing to two points on a table. Concepts such as tomorrow, time, size and distance are not easy to grasp at this young age. Understanding size, time, distance, fact and fiction are all tasks that are part of cognitive development in the preschool years.[2] - Child Growth and Development by Jennifer Paris, Antoinette Ricardo, & Dawn Rymond licensed under CC BY 4.0 ↵ - Lifespan Development - Module 5: Early Childhood by Lumen Learning references Psyc 200 Lifespan Psychology by Laura Overstreet, licensed under CC BY 4.0 ↵	375	common-pile/pressbooks_filtered	https://openfl.pressbooks.pub/childandadol/chapter/objectives-4/	pressbooks	pressbooks-0000.json.gz:40095	https://openfl.pressbooks.pub/childandadol/chapter/objectives-4/
6v_N17Uc8xYi44K8	Religion and chemistry; a re-statement of an old argument,	PREFACE. The conditions under which this work was first published are stated in the preface to the first edition, reprinted below. Although the book has been long out of print, the author has not been able to revise it for a new edition until now, and returning to this work of his youth, after twenty years of active life, he has found nothing in the tone or sentiments of the book which he desired to change. Indeed, larger knowledge has only served to confirm the general convictions therein expressed. But, of necessity, the discovery of new facts and changes in scientific theories have required alterations of phraseology in many places, and more experience has led to greater caution in the statement of conclusions. It was the author's first intention to re-write the whole book on a different plan, and in retaining the popular style of the first edition he has yielded to the judgment of friends who thought that the book would be more useful in its early, fresh form. The discussion of the principles of crystallography in the first edition has been omitted in the revision, because found too abstruse for popular reading ; but the place has been more than supplied by the new matter which has been added. The work is solely a popular exposition of the subjects on which it treats, and this design has precluded a fuller discussion of many points, as well as that precision of statement which might be expected in a more formal essay. By vote, recorded in their proceedings of March 6, 1875, the Directors of the Brooklyn Institute released to the author their copyright in the original work, and he would here express his grateful appreciation of this courtesy. PREFACE TO THE FIRST EDITION. The lectures now published were first delivered before the Brooklyn Institute on Sunday evenings of January and February, 1861, and the larger part of them were subsequently repeated, during the same winter, before the Lowell Institute in Boston, and before the Mechanics* Association of Lowell. The progress of science since that time has rendered necessary many additions, and in revising the lectures for publication, the material has been thus so greatly increased that what was originally prepared and delivered as six lectures is now distributed over ten. At the time when the lectures were written, Mr. Darwin's book on the Origin of Species, then recently published, was exciting great attention, and was thought by many to have an injurious bearing on the argument for design. It was, therefore, made the chief aim of these lectures to show that there is abundant evidence of design in the properties of the chemical elements alone, and hence that the great argument of Natural Theology rests upon a basis which no theories of organic development can shake. In illustrating his subject, the author has used freely all the materials at his command, and if, in any case, he has failed to give due acknowledgment, it has been because by long dwelling on the subject the thoughts of others have become blended with his own. He would here acknowledge his repeated indebtedness to Professor Guyot's work on " Earth and Man,'* to Professor Faraday's published Courses of Elementary Lectures, and to Professor TyndalFs Lectures on " Heat considered as a Mode of Motion." He would also express his especial obligations to the author of " In Memoriam," in whose verses he has discovered a truer appreciation of the difficulties which beset the questions discussed in this volume, than he has ever found in the philosophy of the schools. ATMOSPHERE. The time has been when the Christian .Church was an active antagonist of physical science ; when the whole hierarchy of Rome united to condemn its results and to resist its progress ; when the immediate reward of great discoveries was obloquy and persecution. But all this has passed. The age of dogmatism has gone, and an age of general scepticism has succeeded. The power of traditional authority has given place to the power of ideas, and physical science, which before hardly dared to assert its birthright, and could even be forced to recant, on its knees, its demonstrated truths, has now become one of the rulers of society. By its rapid growth, by its conquests over brute matter, and by its wonderful revelations, it has deservedly gained the highest respect of man, while by multiplying and 1 I THE CHURCH AND SCIENCE. diffusing the comforts of life it has become his acknowledged friend. Every effort is now made to further its progress. Its great discoveries win the applause of nations, and its fortunate students are remembered when the princes and nobles of the earth are forgotten. All this is well. But unfortunately, elated by his success, the stripling has been at times proud and arrogant, usurping authority not his due. Forgetting his early faith, he has approached with irreverent thoughts the holy temple of our religion, and, not content to worship in the outer court, has dared to penetrate into the very Holy of Holies, and apply his material tests even to the vessels of the altar. No wonder that the Church should become alarmed, that many of her best men, holding fast to the sacred dogmas of our religion as the only sure anchor of their faith in this world, and their sole ground of hope for the next, should join in a general cry against the whole tendency of science and its results. But this is a great mistake. Judging of the real character of physical science from the pretensions of a few, and not possessing the power or opportunity of investigating for themselves, these good men are unnecessarily alarmed : the phantom they fear is purely of their own creation, and, could they but know the whole truth, they themselves would see that to ignore the well-established results of science, and to denounce its legitimate tendency, is a policy as short-sighted as it is illiberal and unchristian. ( Fortunately, such fearful souls constitute but a small party in the Christian Church. There is a far nobler and more courageous faith than theirs, — a faith so strong in its convictions that it fears no criticism, however searching, and no scientific analysis, however rigorous it may be, — a faith which finds in the Bible, not a series of dead formulas, but a mass of living truth, — a faith which really believes that the God of nature is the God of grace, and that man was created in the image of this one and only \| God, — R faith which wells up from the depths of the ? soul, which speaks because it believes, which believes because it feels, — a faith whose sources are as hidden as those of the fountain, but whose reality is as living as the verdant landscape which the fountain -^-waters. It is the men with a faith like this who are the really brave Christians. They are not alarmed at the apparent contradictions between science and revelation. By the very imperfections of their own faculties, which they so keenly appreciate, they have been taught that mysteries exist ; nay, they find in these very mysteries the strongest bulwarks of their faith ; for they feel, with Robert Hall, that " a re-T^ ligion without its mysteries would be a temple withj out its God.'* They are fully assured that our minds were framed after the likeness of their Divine original, in order that we, creatures of the dust though we are, might nevertheless in our feeble measure comprehend God's workmanship and sympathize with his divine thoughts ; and they reject as absurd the doctrine that man, thus created an intelligent and sympathizing observer of God's universe, should BRAVE CHRISTIAN FAITH. have been permitted, in the legitimate exercise of the very powers which God has given him, to build up a connected system of science in direct contradiction to those higher and spiritual truths which the Father has been mercifully pleased to reveal to his sinning children through his prophets and his Son. In the sight of this brave Christian faith there can be no essential contradiction between science and revelation. On the contrary, all nature appears radiant with the Divine Presence. " The heavens declare the glory of God, and the7~ firmament showeth his handiwork. Day unto day uttereth speech, and night unto night showeth ;;.vlcnowledge. There is no speech nor language where! their voice is not heard. Their line is gone out! through all the earth, and their words to the end of the world.' ^' But although this glorious song of the Psalmist has been chanted through the ages as expressing the all but universal belief of thinking men, there has always existed at the same time a philosophy which interpreted the facts of nature in a very different way, and within the last few years this philosophy has become more than ever before dogmatic and aggressive. For the present we waive all discussion of the fundamental questions which materialism raises. With the increasing experience of life, we cling ever more and more fondly to the belief that the grand thoughts which the study of nature suggests to our mind are the manifestations of a Being who is not only to be venerated and feared NO NECESSARY ANTAGONISM. 5 but also whom to be reverenced and loved. We believe that the instructions and suggestions of nature are the voices of an all-powerful Friend, who knows our capabilities and infirmities ; who sympathizes in our joys and our sorrows, and who can be touched in our aspirations and our prayers ; a Creator whose laws can not be broken, and whose behests must be obeyed ; but also a Father who ever watches over his children, and who was in Christ reconciling the world unto himself. f We do not, of course, expect to reach such a faith ] ( as this through the study of nature alone. It comes not from the observation of external phenomena, but through the affections and aspirations of the soul, which finds in the Christian revelation that which answers to its needs and satisfies its cravings; Any system of natural theology like that of Paley, which looks for its evidences solely to external phenomena, is of necessity defective and powerless. If nature could rise of her own self to spiritual things, there would have been no necessity for a revelation. Indeed, the attempt to establish a spiritual truth by the evidence of material phenomena, is, mutatis mutandis, but a repetition of the error of Aristotle and his school, who vainly sought to frame a system of natural philosophy independently of observation. The only satisfactory evidences of the truths of Christianity, independent of the historical record, are to be found in its adaptation to the spiritual needs of men, and it is such evidences of design alone that have persuaded the world. RELIGION AND CHEMISTRY. Nevertheless, while we cannot expect to prove the fundamental principles of Christian theism by the evidences of material nature, it seems to us that an advantage may be gained by discussing material phenomena from the theistic point of view. The purely mechanical aspects of nature are now so prominently presented by ingenious and powerful writers that it may be a satisfaction to many thoughtful Christians if it can be shown that the same facts may be interpreted in a very different way, and that these facts are at least as consistent with the Christian theory of the origin of the universe as with the theory of the materialist. In this conclusion the Christian philosopher may securely rest, looking for the confirmation of his inherited faith to his own spiritual experience, in which alone convincing evidence can be found, according to the Master's promise: " If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself." The illustrations of the attributes of God, which may be drawn from the constitution of matter, are conveniently divided into two classes, — first, those which appear in the adaptation of various means to a particular end, and, second, those which are to be found in the unity of plan according to which the whole frame of nature has been constructed. The first class are exhibited by the properties of matter, the second by the so-called physical laws and forces. In following out, then, the order which seems to be so obviously indicated by the nature of the case, I shall ask you, in the first place, to study with me ARGUMENT FOR DESIGN. the physical condition of our atmosphere, and the properties of the various materials of which it consists ; and I am sure we shall not fail to find in one and all abundant evidence of the wisdom, goodness, and power of God. Having thus made you acquainted with some of the more important scientific facts required for my argument, I shall next direct your attention to those grander demonstrations of God's wisdom and power which appear in the great laws and forces, by which the whole material universe is upheld, and lastly an examination of the relative limits of scientific and religious thought will form an appropriate termination for the course. The argument from special adaptations which lies at the basis of most works on natural theology is condensed by Dugald Stewart into two simple propositions. The one is, " that everything which begins to exist must have a cause ; ' the other, " that a combination of means conspiring to a particular end implies intelligence.'* To these might be added the two equally clear propositions stated by Dr. Reid : first, " that design may be traced from its effects ; " second, " that there are evidences of design in the universe." I do not at present intend to discuss the logical validity of this argument, or the general value of analogical reasoning which it implies. Such discussions belong particularly to the province of metaphysics, and I willingly leave them to abler hands. It will be my chief object in these lectures to bring to your notice a few of the numberless indications of adaptation in the materials of our atmosphere, assuming for the present that these adaptations are evidences of design, and therefore evidences of the existence of a personal God, infinite in wisdom, absolute in power. When we have thus become acquainted with some of the facts on which the argument rests, we may then profitably consider the validity of the reasoning, at least so far as to weigh the objections which modern materialism has urged against it. It must, however, be constantly borne in mind that the portion of the subject with which we are to deal should occupy only a very subordinate position in any comprehensive scheme of natural theology. We have already expressed the opinion that the only conclusive evidences of the truth of Christianity, apart from the historical record, are those based on its adaptation to the spiritual wants of men, and all other facts are secondary to this great central truth. But even when established on its broadest basis, I would not press the arguments of natural theology too far. For myself, I believe that the facts of human nature themselves all tend to prove that a divine revelation is the only legitimate basis for a system of religion, and that an historical faith based on a supernatural revelation is the only religion possible for imperfect humanity. Indeed, I am led to think we find evidence of the goodness of our Heavenly Father in the very circumstance that the foundations of all knowledge have been laid in such obscurity that no unaided human intellect can wholly dispel the cloud which hides the Creator from our sight,— PROVINCE OF NATURAL THEOLOGY. 9 ** To feel, although no tongue can prove, That every cloud that spreads above And veileth love, itself is love." This very obscurity humbles the pride of human learning, and raises its constant warning against that intellectual idolatry which would substitute its shallow philosophy for the simple truth as it is in Jesus. The Bible once received, science can furnish abundant illustrations of the attributes of the Being therein revealed ; but even with all the illumination which has been the immediate or secondary result of Christianity, man is hopeless without its authority, and I would not give the slightest shadow of support to that irreverent presumption which, guided by what it calls the unaided light of nature, would construct a system of religion out of passions, intuitions, and I know not what absurdity. But still it must be remembered that the Christian revelation does not prove the existence of God ; on the contrary, it appeals to a belief in his being that already exists in the mind of man. The Bible opens with this assumption. The first line asserts that — With all men a belief in some Almighty Power overshadowing their being grows up spontaneously in the heart, they know not how ; but the educated and the intelligent seek further to find its logical grounds in the evidences of nature. 1* / Here, then, is the first great office of natural / theology. It furnishes the logical basis on which I the whole scheme of revealed religion given us in the Bible rests. I have no desire to over-estimate the importance of my subject. For myself, I believe, with Paley, , and the other eminent writers of the same class, that \ the fundamental truths of our religion can be inferred from the constitution of the human mind and \ from the course of nature with as much certainty as 'analogical reasoning can ever give. But still I know that the evidence is not demonstrative and not likely to convince the sceptic ; for in the last analysis it rests on certain assumptions which he will not admit. And it is in vain to urge that these assumpItions are really intuitive truths and tacitly admitted by the whole human race ; for he easily replies, that they are not intuitive to his mind. • Nevertheless, the evidences of God in nature — including, of course, the human soul — are the only proof we have or can have of his existence, and they are, therefore, the only logical basis of the Christian revelation. Nature and revelation are parts of one and the same system, and, however much our prejudices may obscure the fact, Christianity rests on natural religion, and cannot be logically defended if the authority of the last is denied. But however great the value of natural theology, considered as the basis on which revelation rests, this is not its only or most important office. In the present age of the world, it confers a still more inestimable benefit on mankind by confirming, illustrat- ^ If it be asked of what value are further illustra\ tions of admitted truths, I answer, that there is an j important class of nominal Christians who are more lopen to impressions from the study of nature than jto direct appeals to the heart. It is true that the great mass of mankind must be Christianized, if at all, through the affections and by the hard discipline of sorrow ; but there are some who, not yet tried in the fiery furnace of affliction, have first felt their Father's hand and recognized his love while contemplating his works. I do not say that persons so touched are already Christians, but I do say that the first step has been taken, and that is a great deal. It may require many years of sad experience and many a bitter pang of disappointment before they come to kneel humbly at their Saviour's feet ; but, like the great Apostle, they will always look back to the time when the Divine presence first visibly shone before them as the turning period of their life. While, therefore, I should be the first to condemn that hollow naturalism which would substitute a system of natural theism for the simple doctrines of the Bible, I must also deprecate that prejudice which prevents many clergymen, through fear of this tendency of the age, from availing themselves of the aid of science in enforcing the fundamental truths of our religion. I assure them they thus neglect a most important means of influence over educated and thinking men, — a means of influence always important, but never more so than in an age which is marked by its cultivation of practical science, and in a country where so large a portion of the active energy of the community has taken this practical direction. The danger of our time is not so much a philosophical scepticism as a practical materialism. The fear is, not that men should reason themselves into unbelief, but that, spending their whole lives in developing the powers of nature, they should practically worship the dead matter rather than the living God. If, however, we can j make such persons feel that the material is but a form of the spiritual, and that in fact the spiritual is nowhere more manifest than in those very laws and forces which they so much idolize, we shall not change, it is true, the tendency of the age, but we shall ennoble and sanctify it. The whole material universe will become transfigured, and nature will no longer be seen as a wonderful mechanical application of blind forces, but as a living embodiment of the Eternal One. Nature-worship may continue, but it will have lost its idolatry ; for it will be no longer the machine that is worshiped, but that same Living Spirit which spoke in tones of thundet* from the clouds of Sinai and in accents of mercy at the baptism of Christ. r^ I know it is said that nature conceals rather than ( reveals God, and in a certain sense it is undoubtedly j true that He is hidden from us behind the veil of his I works ; but since it is permitted to man by the exercise of his intelligence to Hft in part this veil, it is certainly the duty, as it should be the privilege, of the ministers of religion to show forth the un- forms. But why multiply arguments when we have the authority of the Great Teacher himself, who frequently appealed to nature to illustrate and enforce the divine truths which he came on earth to reveal ? We have indeed the whole summary of Natural Theology in His simple words : ** Wherefore, if God so clothe the grass of the field, which to-day is, and to-morrow is cast into the oven, shall he not much more clothe you, O ye of little faith?" With, then, such authority as this, let us not despise the beginnings because they are not the end, or undervalue the means by which many a noble soul has been led to the foot of the Cross. Without seeking, therefore, to vindicate further the claims of my subject, I will at once enter upon the plan already proposed for this course of lectures, and will first ask your attention to the illustrations of the wisdom, goodness, and power of God, which may be discovered in the constitution of our atmosphere. In endeavoring to carry out this plan, I shall require all your indulgence and all your kind forbearance. From the very nature of the case, it will be necessary to start from first principles, and much of the way we are to travel together will be uninteresting and dull. If, however, the path shall lead us to the summit of that holy mountain from which we can gain a clearer vision of spiritual things, we shall soon forget the toil and difficulty of the ascent. We have no extravagant expectations of the result. 14 ADAPTATIONS TO BE STUDIED We do not hope to convince the sceptic, or to arouse the indifferent from their practical unbelief. Our only hope is — and this we entertain in all humility — that, by pointing out a few of the footprints of the Creator which lie thickly along our daily path, we may encourage some earnest student toiling forward on his journey of life. May God grant to us all the richest blessings of his grace ; for though man may plant and water. He only giveth the increase. The illustrations of the attributes of God presented to us by the atmosphere are especiafly manifest in those adaptations of properties by which it has been made to subserve the welfare and happiness of mankind, and this is to be expected, not only because these relations have been the most studied, and are, therefore, the best known, but also because the familiar phenomena through which our intelligences are connected with the external world, are the im.mediate objects of our observation and cognizance. Here, however, as always in the study of nature, we must be careful to avoid the error of considering man as the sole end of creation, and of interpreting all phenomena with reference to him alone. The material universe is the manifestation of one grand creative thought, as comprehensive in the diversity of the parts as it is grand in the unity of the whole. These parts have been so wondrously joined and skilfully wrought together, that each is linked with each, and one with all. In this divine economy nothing is wanting, nothing is superfluous, and what seems to our feeble vision least important \|s^ as_ess^^d\|liaxom-- Amidst all this wonderful variety in unity, man stands the culminating glory of the whole. Made in the image of his Creator, and but " a little lower than the angels,'* he has been intrusted with dominion and power over all the brute matter which surrounds him. Through the long ages of geological history the earth was preparing for his dwelling, and in the earliest forms of animal life his coming was prefigured and foretold. It will be natural, there- fore, to^ consider the adaptations of the atmosphere with special reference to him ; and this we may do legitimately, without losing sight of the grand idea which underlies the whole, and of which man is only the nobler part. The atmosphere is a vast ocean of aeriform matter, enveloping the earth like a mantle, and rising to the height of many miles above our heads, but constantly diminishing in density as the elevation increases. At the height of about three miles and a half (3.43) the density is only one-half as great as at the level of the sea; and at the height of forty miles it is less than in the exhausted receiver of the best air-pumps. How much higher than this the atmosphere extends, it is impossible to determine with accuracy. In this ocean of air all bodies on the surface of the globe are immersed. It is so subtle l6 DESCRIPTION OF THE ATMOSPHERE. that it penetrates into the minute pores of matter, and fills the cavities of all organized being. It is the medium in which all vital processes both of plants and animals take place, and in which all human activity has its seat. Let us see now with what wisdom its properties have been adapted to the important ends which it is appointed to subserve. Consider, in the first place, the physical state of the atmosphere, its very aeriform condition. This air is as truly matter as the solid planks on which we are treading, or the granite rocks on which this building rests. It is far less dense, it is true, but then it has all the essential properties of matter. It fills space. It resists with an ever-increasing force all attempts to condense it ; and, moreover, it has weight. But how different in condition from the solid rock ! — so different that to the uneducated it hardly seems material ; and in our common language we speak of a space which is filled only with air as empty. Its particles are endowed with such perfect freedom of motion, and yield so readily to the slightest pressure, that we move through it without feeling its presence. It is firm enough to support the wings of the lark as he mounts the sky, and yet so yielding as not to detain the tiniest insect in its rapid flight. The physical condition of the atmosphere will still further excite our admiration, when we consider the wonderful play of forces by which it is upheld. It may not be known to you all that upon this mass of air, outwardly so calm and passive, there are con- stantly acting two mighty forces, — the force of gravitation and the force of heat. In virtue of the force of heat the particles of the atmosphere mutually repel each other, and the whole mass, like a bent spring, tends to break from its confinement and to expand into the surrounding space ; but this it cannot do, for by the power of gravitation it is held with a firm grasp to the surface of the globe. Were this grasp for a moment relaxed, the atmosphere would dash off with explosive violence and be lost in the immensity which surrounds us. How great the force is which is required to restrain the expansive tendency of the atmosphere few persons have an adequate conception, because the two opposing forces are so perfectly balanced that we are obliged to call in the aid of experiment in order to render their effects evident. So true is this, that the world never even dreamed of their existence until within two hundred years, and the story of the discovery is one of the most remarkable in the history of inductive philosophy. This story is well known ; but as it is short, and teaches us an important truth, you will pardon its repetition. Every one who has seen a common pump is familiar with the fact that it is the pressure of the air which causes the water to rise in the suction-pipe, and this suction is one manifestation of that force by which the atmosphere is held so firmly to the surface of the globe. The pump, however, was used long before the discovery of the pressure of the atmosphere, and its action was explained by a principle which seemed perfectly satisfactory then, but 1 8 NATURE ABHORS A VACUUM. which sounds strangely enough to modern ears. The principle appears first to have originated with the Aristotelians, and was expressed in the phrase, " Nature abhors a vacuum.'* These ancient philosophers noticed that space was always filled with some material substance, and that the moment a solid body was removed air or water always rushed in to fill the empty space. Hence they concluded that it was a universal law of nature that space could not exist unoccupied by matter, and the phrase just quoted was merely their figurative expression of this philosophical idea. When, for example, the piston of a common pump was drawn up, the rise of the water was explained by declaring, that, as from the nature of things a vacuum could not exist, the water necessarily filled the space deserted by the piston. This physical dogma served the purpose of natural philosophy for two thousand years, and it was not until the seventeenth century that men discovered any limit to nature's abhorrence of a vacuum. Near the middle of that century some engineers were employed by the Duke of Tuscany to sink a well in the neighborhood of Florence to an unusual depth. They finished their work, but on adjusting the pump they found to their surprise that it would not work. With all their efforts the water would rise only a little more than thirty feet, and by no ingenuity or skill could they raise it an inch higher. More disgusted with nature than nature was with the vacuum in their pump, they applied to Galileo, then an old man, living in his villa on the brow of Fiesole. He could not aid them, but he is said to have replied, half in jest, half in earnest, that nature did not abhor a vacuum above thirty feet. Had this incident occurred earlier in his career, Galileo would undoubtedly have added to the other jewels of his crown a brighter gem than all, but now the vigor of his manhood was spent ; he had done his work, and, worn out by the persecution M. a bigoted priesthood, he was peacefully resting from his life's labor, and calmly awaiting the close. But the key which the incident had furnished was not lost. It passed into able hands, and it was the fortune of Torricelli, Galileo's best pupil, to unlock the secret. This young Italian philosopher, whose clear, intellect had been trained in the mechanical philosophy of his great master, saw at once that a column of water thirty-three feet high, and no higher, could not be sustained in a cylindrical tube by a mere metaphysical abstraction. This effect, he said, must be the result of some mechanical force equivalent to the weight of the mass of water sustained. It was not difficult to prove the correctness of this reasoning, for it was evident that if a column of water was sustained at the height of thirty-three feet in the suction-pipe of a pump by a constant force, the same force could only sustain a column of a heavier liquid at a proportionally less height. So Torricelli tried mercury, a liquid thirteen and a half times heavier than water, and the result was as he had anticipated. The force which raised the column of water thirty-three feet could only raise a column of mercury to the height 20 EXPERIMENT OF TORRICELLI. of thirty inches, which is thirteen and a half times less than thirty-three feet. Torricelli did not, however, make this experiment with a pump, but with an apparatus of his own, much simpler, and equally effective. He took a long glass tube, open at one end, filled it with mercury, and, having closed the opening with his thumb, inverted the tube, and plunged the open end in a basin of mercury ; on removing his thumb, the mercury, instead of remaining in the tube, and thus satisfying nature's abhorrence of a vacuum, fell, as he expected, and, after a few oscillations, came to rest at a height of about thirty inches above the level of the mercury in the basin. The correctness of his induction having been thus verified, Torricelli at once concluded that it must be the pressure of the air which sustained both the water in the pump and the mercury in his tube. This experiment excited a great sensation in Europe ; but, as might naturally have been expected, the old physical dogma was not easily laid aside, and Torricelli did not live to see his opinion generally received. It was left to the celebrated Blaise Pascal to convince the world that Torricelli was right, and this he did by one of those master-strokes of genius which at once silence controversy. " If,'* said Pascal, " it be really the weight of the atmosphere under which we live that supports the column of mercury in Torricelli's tube, we shall find, by transporting this tube upward in the atmosphere, that in proportion as it leaves below it more and more of the air, and has consequently less and DEMONSTRATION OF PASCAL. 21 less above it, there will be a less column sustained in the tube, inasmuch as the weight of the air above the tube, which is declared by Torricelli to be the force which sustains it, will be diminished by the increased elevation of the tube." Accordingly Pascal carried the tube to the top of a church-steeple in Paris, and observed that the mercury fell slightly ; but not satisfied with this result, he wrote to his brother-in-law, who lived near the high mountain of Puy de Dome, in Auvergne, to make the experiment there, where the result would be more decisive. '* You see," he writes, "that if it happens that the height of the mercury at the top of the hill be less than at the bottom (which I have many reasons to believe, though all those who have thought about it are of a different opinion), it will follow that the weight and pressure of the air are the sole cause of this suspension, and not the horror of a vacuum ; since it is very certain that there is more air to weigh on it at the bottom than at the top ; while we cannot say that nature abhors a vacuum at the foot of a mountain more than on its summit." M. Perrier, Pascal's correspondent, made the observation as he desired, and found a difference of about three inches, "which," as he replies, "ravished us with admiration and astonishment." Thus it was that man first learned to recognize the existence of that power, which retains the atmosphere on the surface of the globe, and the history of the discovery should humble our intellectual pride and teach us to hold our knowledge with rev- 22 THE OLD DOGMA erence and humility. This old scientific dogma of the seventeenth century never fails to excite a smile, and we are inclined to wonder how man could ever have believed what now appears so absurd ; but if, like an antiquary, we imbue our minds with the spirit of that age, it will be seen, not only that the dogma was not essentially absurd, but also that the philosophical idea,^clothed in those quaint terms, appeared to the scientific men of the period as truly a legitimate induction from observed facts as the law of gravitation seems to us. And the induction was legitimate ; but since the known facts did not cover the whole ground, they gave only a very partial truth. The Grand Duke's pump was the first failing case, and proved, not that the old principle was absolutely false, but only that its application was very limited. Thanks to Galileo, Torricelli, Pascal, and Newton— noble line of genius — nature's abhorrence of a vacuum gave place to the law of gravitation, and two centuries of unparalleled scientific activity have only served to confirm the truth, and extend the domain of Newton's grand generalization ; but even after this signal triumph, who now feels fully assured that the law of gravitation may not find its failing case? and when, two centuries hence, the future historian comes to write the history of inductive philosophy, who can feel certain that Aristotle's dogma and Newton's law may not both be condescendingly noticed among the partial truths which served the purposes of science in its infancy and childhood ? A PARTIAL TRUTH. 23 Let me not be understood to imply a belief that man cannot attain to any absolute scientific truth, for I believe that he can, "a^nSTl feel that every great generalization brings him a step nearer to the promised goal ; but I wish here at the outset most strongly to impress the distinction between the undoubted facts of science, and the laws and principles which have grown up around them, and by which they have been embodied in our systems of philosophy, — the distinction, in a word, between the observed phenomena of nature, and mans interpretation of the phenomena. This distinction, so obvious when stated, is too often forgotten, and is necessarily overlooked in our scientific text-books. It is the sole aim of these elementary treatises to teach the present state of knowledge, and they would fail in their object if they attempted by a critical analysis to separate the phenomena from the laws or systems by which alone the facts of nature are correlated and rendered intelligible. But although while studying science itself, we may for the time waive the distinction between fact and theory, the moment we come to compare the results of science with the eternal verities of religion, the distinction here enforced becomes of paramount importance, and it must be our chief aim to separate that which is absolute and eternal truth from that which, even in its highest development, is the result of human thought, and, like all things human, subject to limitations and liable to change. 24 FACT AND THEORY. churchmen would have been less bitter and more fruitful in truth ; the philosophers would have been willing to waive their theories, and the churchmen would have been led to respect the results of science, and conform their theology to the indisputable truths which God has been pleased to reveal through nature no less plainly than in his written word ; and if the trite anecdote of Galileo and the pumpmakers serve to impress the distinction on our minds, this digression will not have been made in vain. You must all have recognized in Torricelli's tube our modern barometer. By means of this wellknown instrument we can readily estimate the pressure of the atmosphere, and determine the amount in our human standards of measurement. It can be readily proved that the pressure of the atmosphere is about fifteen pounds on every square inch of the earth^s surface, and if, starting from this well-known fact, you calculate the amount of pressure on any extended surface, you will be astonished at the result. For example, the pressure exerted by the atmosphere on the area on which this building stands is much greater than the whole weight of the building itself. The pressure on a man of ordinary stature is about sixteen tons ; that on one square mile of surface is equal to over twenty-six million tons. How great, then, must be the pressure on the whole surface of the globe, or, what is the same thing, how great is the intensity of that ever-acting power, which holds the atmosphere in its appointed place ! It would not be difficult to calculate the amount and to express it in numbers; but these numbers would convey to you no definite idea, for our minds are incapable of forming an adequate conception of such immensity. The attempt to grasp it only exposes our weakness, and yet this force, immense as it is, is so delicately balanced by the sweet influences of the sunbeam, that it does not so much as shake the aspen-leaf or break the gossamer. If we believe no more than this, that the world was once created by God, what must be the power and wisdom of a being who could appoint these mighty forces and adjust them with such perfect precision ! . But if we also believe that these forces are direct emanations of Divine Power, — that it is God himself who with his own right hand holds the atmosphere in its place, and appoints its bounds, — then all nature assumes a more glorious aspect, and we feel that we are indeed surrounded by the Divine Presence. Yet this force, which we find so far beyond our powers of conception, is but a secondary phase of that immeasurably greater power which brings forth Mazzaroth in his season, and guides Arcturus with his sons. How futile all attempts to measure Divine power ! We select some one of the feeble forces acting around us, and succeed in reducing its value to our human standards of comparison, and expressing this value in numbers ; but the numbers, when obtained, are beyond our grasp, and we find that we have merely mounted to a little higher platform, from which we discover numberless other forces immeasurably greater than the first. Something, however, has 26 IDEA OF THE INFINITE. been gained. We have attained to the idea of the infinite ; and to thoroughly apprehend the existence of the infinite, is to take the first step toward recognizing the existence of a God. I know it will be said that man cannot comprehend the infinite, and if by this statement it is only meant to affirm the declaration of the Bible, that man cannot "find out the Almighty unto perfection," not even the most visionary dreamer would question the position. But there is a class of philosophers at the present day who think to enforce the authority of revelation by maintaining the doctrine that man can know absolutely nothing of the infinite, — nothing more than he now knows of the facts or principles of science to be hereafter discovered ; that, indeed, the very term infinite implies a negation of all cognizable qualities. To me, this position seems fatal to. the very cause it is intended to defend, and surrenders all the approaches of the citadel to the infidel. For if there is in man no possibility of apprehending the infinite, even to the smallest degree, I can see nothing to which revelation can appeal. He has then no power to distinguish between the Divine and the human. But it is riot so. Revelation implies, and all experience shows, that man can recognize the presence of the infinite by attributes as clear and unmis-' takable as those which mark the presence of the finite matter around him. He may not be able to comprehend a single attribute of the infinite in its essence; but as the mathematician, dealing with infinitesimal quantities, which he cannot fully un- derstand, arrives at truths of the material world with all the certainty of demonstration, so the mental philosopher may attain to moral truths in regard to the Infinite Being, although the very terms he employs may be veiled in impenetrable mystery. And what is the true human conception of the infinite? It is not merely something which we feel to be very great indeed, but it is something which we feel surpasses our utmost conceptions of the great, — something which, let us account it as great as we please, yet, wherever the inability of our mental power fixes the limit of our conception, will still be felt to be greater than the greatest. We cannot gaze into the heavens without awe ; we cannot examine the wonders of the dew-drop without reverence ; we cannot look into our own souls without trembling. It is the same invisible Presence everywhere, and however long false philosophy > may conceal the vision, or material cares and pleas- :^ ^ ures blind the senses, when man once recognizes o^^ ^^^ its existence he instinctively worships and adores. ^^ The far-reaching relations of the adaptations we '^ are now studying become evident when we consider that the density of the atmosphere is one of the conditions of organic life on the surface of the globe. By density is meant, I need not state, the quantity of matter which the atmosphere contains in a given volume ; for example, in a cubic yard. This quantity is capable of exact measurement, and although to a certain extent variable, it is constant in the same place, under the same conditions of temperature and pressure. In this latitude, at the level of the sea, one cubic yard of the atmosphere, when dry and under the . normal conditions of temperature and pressure, contains about two pounds of air, and this weight is the measure of its density. Now we find that the orgarkization of plants and animals, including man, has been adjusted to the density of the air, and illustrations of this adaptation will be met with as we proceed. But accepting the fact for the present as universally conceded, let us consider the conditions on which this adaptation of the air to our physical organization rests. The density of the atmosphere may be said to depend upon four conditions : first, on the inherent nature of the substance which we call air itself; secondly, on the intensity of gravity ; thirdly, on the total quantity of air on the globe ; and, lastly, on the temperature. The influence of the first condition is not understood, but that of the last three we can readily trace. If the intensity of the force of gravity at the surface of the earth were to change, other circumstances remaining the same, the density of the atmosphere would change in the same proportion. Thus, for example, if the intensity of gravity on the earth were as great as it is on the surface of the sun, the density of the atmosphere would be twenty-eight times as great as at present ; or if this intensity were reduced to that which exists on the surface of the moon, the density would be diminished to one-sixth of the existing density. stant, precisely the same effect would result from any variation in the total quantity of the atmosphere. Were the whole amount of air on the earth increased or diminished, the density of the atmosphere at its surface would also be increased or diminished in the same proportion. Still further, assuming that, while the intensity of gravity and the mass of the atmosphere remained fixed, the temperature were changed, then also the density of the atmosphere would vary, and by a quantity which can be easily determined. By accurate experiments it has been ascertained that an elevation of temperature equivalent to about five hundred degrees of our Fahrenheit thermometer would reduce the density to one-half ; and, on the other hand, that a reduction of temperature would increase the density in the same proportion. Consider next what these relations imply. Reflect that the intensity of the force of gravity depends upon the mass of the earth. Remember that the mean temperature depends upon the distance of the earth from the sun, and you will see that not only the actual size of the earth, but also its distance from the sun, and the quantity of air on its surface, were all necessary conditions in order that the atmosphere should have its present density, and thus become the fit abode for the actual families of organic beings. If any one of these conditions had been different, the same result would not have been attained, and man, as he exists, could not have lived on this globe. 30 UNITY OF THE DESIGN. heaven with the span, and comprehended the dust of the earth in a measure, and weighed the mountains in scales, and the hills in a balance," who " formed man of the dust of the ground, and breathed into his nostrils the breath of life." The unity of the design implies the oneness of the designer, and although the adaptations just considered may not exclude every possible atheistic theory of cosmogony, yet they show conclusively that, if there is design anywhere, there is design everywhere ; if there is design in the least, there is design also in the greatest, and design in the atom may thus confirm the evidence of design in man. During a recent journey in Switzerland, at the close of a delightful summer's day, in the early part of July, I arrived at Interlachen, in company with a number of fellow-travellers. We had been saiHng on the beautiful lake of Brienz, and some minutes before we reached our destination the sun had set, and the mountains had already cast their long shadows across the lake. Early in the kfternoon the clouds had settled on the nearer hills, and we had been disappointed at not obtaining a view of the distant summits of the Bernese Oberland ; but suddenly, as the boat neared the shore, the magnificent peak of the Jungfrau appeared from behind the veil of clouds, clothed in her white mantle of everlasting snow, and bathed with a flood of rosy light. The effect thus heightened by the contrast was grand beyond description, and as beautiful as it was grand. It seemed like a vision of the Heavenly Kingdom, — as if the glory of God had rested on the mountain. The scene completely filled the soul, and the heart overflowed with gratitude for the blessing it enjoyed. It was felt to be one of the 32 THE ATMOSPHERE AND LIGHT. great privileges of a lifetime, and his would have been a dull understanding, and a duller heart, which did not recognize the Giver in the gift. The view so riveted the attention that we hardly noticed our arrival, and as we walked to the hotel we watched the successive shades of crimson and purple as they flitted up the mountain, until the last blended in the gray of the twilight. It may not be permitted to many to behold the Jungfrau blushing before her retiring lord, but all have witnessed the same effect on even a grander scale, when the white clouds, piled up on the western horizon like vast mountain chains, become, at evening, resplendent with the rays of the setting sun ; and many have watched their varying tints of gold and purple, until at last their ghostly forms vanished in the dusk of the evening, and the stars came out to take up with their measured twinkling the silent song of praise. Perhaps, also, there may be some who, after anxious watching through the night, have felt their hearts strengthened and their hopes revived when the blush of morning reassured them of their Father's providence, and all nature smiled in the floods of returning light. All these glorious visions, all this beauty, and all the pure emotions of our hearts which they excite, we owe, my friends, to the skill with which the physical qualities of the atmosphere have been adjusted to the wants of our physical and moral natures, and they all thus become the silent witnesses not only of the wisdom, but also of the goodness of our God. TRANSPARENCY. 33 We have already, in the first lecture, discussed some of the adaptations of the physical condition of the atmosphere to the purposes which it subserves on the globe, and I wish this evening to develop still further the same subject, by considering a few additional examples ; and first I will ask your attention to those evidences of design which are to be found in the f-elations of the atmosphere to light and heat. Here, however, I am met by a difficulty. In order to explain fully these relations it would be necessary to develop from first principles the sciences of optics and thermotics, and to do this in a popular manner would require several lectures. These sciences furnish some of the most wonderful evidences of design which are to be found in nature, and I have no doubt will be given their appropriate place in this series of lectures. Without, therefore, attempting any detailed explanations, I will merely bring before you a few facts, drawn from these departments of knowledge, which illustrate the adaptations of the atmosphere to its appointed ends. The atmosphere, although very much more pervious to light than any kind of solid or liquid matter, is far from being perfectly transparent. Indeed, the reverse is sufficiently evident from our daily experience. Every one has noticed that distant objects appear less distinct in proportion as they are removed, their colors become fainter, the contrast between light and shade less marked, and that they seem as if covered with a pale blue veil. This effect, always noticed on distant mountains, is owing to a partial absorption of the light while passing through 2 34 DIFFUSION OF LIGHT. the atmosphere ; for, were the passage of the rays wholly unimpeded, all objects, although reduced in size in proportion to their distance, would appear equally distinct, and their colors equally brilliant. The transparency of the atmosphere differs very greatly under different circumstances, but it has been estimated that, under the most favorable conditions, at least thirty per cent, of all the light coming from the heavenly bodies is absorbed before reaching the surface of the earth, and in our latitude, at this season, even when the sun is on the meridian and the sky clear, fully one-half of his rays are thus spent. Do not suppose, however, that all the light so expended is lost. Quite the contrary, for every particle of the atmosphere, illuminated by the sunbeam, becomes itself a new centre of emission, radiating the light in every direction. This diffusion of the sun's rays is the cause of that wonderful effect which we term daylight. I say wonderful effect, for, although so familiar, it is one of the most remarkable results of skilful adaptation and infinite wisdom. The very daylight which streams in at the open windows of our houses, filling them with cheerfulness, and penetrating to their inmost recesses, which enlivens the whole landscape, and which bars and bolts cannot wholly exclude even from the prisoner's dungeon, is another evidence of the adaptation of the atmosphere to the constitution of man. Indeed, the atmosphere is as much an essential condition of our seeing as of our breathing, and the immeasurable pleasure which we derive from our sense of vision depends upon its adaptation to the organization of the eye. Were it not for the diffusive effect of the atmosphere on the sun's Hght, the contrast between light and shadows would be so greatly increased that, while objects directly illuminated by the sun would shine so brilliantly as to dazzle the eyes, all surrounding objects would be in darkness, and the interior of our dwellings would be as dark as night. Our eyes, as little fitted to such conditions as our lungs, would be blinded by the sudden alternations, and distinct vision would be impossible. This is not a matter of theory, for similar effects are observed on the summits of lofty mountains, where the air is much rarer than at the sea level. On the top of Mont Blanc the sky has a blackish hue, and the stars are seen at midday; the glare of the direct light is insupportable to the eye, and even the reflection from the snow blisters the unprotected skin, while at the same time the contrast between light and shade, unnaturally increased, gives to all near objects a peculiar and ghastly aspect. We have here, it is true, a very great diminution in the density of the air ; but when you reflect upon what delicate contrasts of light and shade the beauty of a landscape depends, — the clearness of the foreground, the gray of the middle distance, and the tender purple of the distant hills all blending into one harmonious whole, — you can appreciate how slight a change would disturb the result, and deprive the sense of beauty of its purest enjoyment. 36 COLOR OF THE SKY. light, and in diffusing their action ; but the atmosphere has also, under certain conditions, the power of decomposing the sun's rays, and thus producing, not only those displays of gorgeous tints which we witness in the sunset clouds, but also the pure blue which colors the dome of heaven. In regard to the precise means which are employed by nature to produce these results, scientific men are not agreed. It has been proved that the blue color of the sky is seen by reflected light, and it is probable that the color is caused by repeated reflections of the sun's rays from the surfaces of the innumerable small water-bubbles which are constantly floating in the atmosphere. You have all noticed the blue color of the soap-bubble shortly before it breaks. This color is caused by the action of the very thin film of water in decomposing the light reflected from its surface, and it is supposed to be an action of the same sort, only very much increased by repeated reflections, which gives to the sky its azure hue. While the blue color of the sky appears to result from changes in the white light of the sun caused by reflection, it is equally probable that the sunset tints arise from changes in the same white light caused by an unequal absorption of its different colored rays during their transmission through the atmosphere. Here, again, the vapor in the air is supposed to be the active agent ; and the theory is, that the tints are produced while the vapor is condensing into clouds, — a change which naturally occurs at sunset. But this is a mere theory, and perfect. So far, however, as our present argument is concerned, it is not essential that we should understand exactly how these glorious results are obtained. It is enough that we are constantly enjoying their beauty, and that we know they are owing to the peculiar constitution of the atmosphere. When future discoveries shall bring to light the methods, at present secret, by which nature gilds the sunset clouds and covers our beautiful dwelling-place with its canopy of blue, we shall unquestionably find fresh evidences of God's wisdom ; but even now, when ignorant, perhaps, of these hidden causes, we have that which is far more excellent, the most conclusive evidence of His goodness and love. Our Father has not only adapted the atmosphere to the wants of our bodies, and made it conducive to our physical enjoyment, but He has also made it the scene of the highest beauty, — a beauty which satisfies the longings of our souls and calls forth their noblest and purest aspirations. Man, sinful as he is, cannot look up into the pure blue of heaven without a sense of reproach, and the feeling that it is a fit emblem of the kingdom of purity and peace. And when the setting sun lights up the evening altar in the West, who "can repress the rising prayer of devotion, and hesitate to believe, with the child, that his Heavenly Father is smiling behind the clouds ? There is a depth to the beauty of nature which man cannot fathom. Poetry cannot describe it, and the highest art only displays 38 WAVE THEORY. its weakness when it attempts to copy it. The savage feels that it is immeasurably above him, and worships it. The artist seeks to attain it, but the more he strives, the more it surpasses his power, and he dies disappointed, unless, happily, he finds that the perfect ideal has been realized only in Christ, and thus through nature is led up to nature's God. Yes ! the beauty of nature is in the Infinite Presence it conceals, and, unconsciously though it may be, it is the spirit, not the matter, which the artist loves. Such are some of the evidences of design which we discover in the relations of the atmosphere to light. Let us now examine some of its relations to heat, which v/e shall find not less instructive. It was formerly supposed that the rays of heat, although accompanying the luminous rays in the sunbeam, were essentially different from those of light. But it is now almost universally believed that the rays of heat differ from those of light only, at most, as one color differs from another, and that even the same rays, which, falling on the retina of the eye, excite the sensation of light, when falling on the nerves of feeling may excite heat. But what, you may ask, is the difference between the different colors? The subject is somewhat abstruse, but if you will follow me attentively for a few minutes I will try to make it intelligible. Every one who has dropped a stone into the water of a still lake has noticed the system of waves which, with its ever-increasing circles, spreads in every direction from the stone ; but all may not WAVES OF SOUND. 39 know that when two stones are struck together in the air a similar system of aerial waves spreads, in ever-widening spheres, through the atmosphere, and that it is these waves breaking on the tympanum of our ears, like the waves of water on a sand-beach, which produce the sensation we call sound. Two stones thus struck together give rise to waves of unequal size, following one another at irregular intervals ; and such waves produce an unpleasant sensation on our auditory nerves, which we call noise. But if, instead of striking together two stones, we set in vibration the string of a pianoforte or the reed of an organ-pipe, we excite a system of waves, all of equal size, and succeeding one another with perfect regularity, and these breaking on the ear produce by their regular beats what we call a musical note. If the waves follow one another with such rapidity that one hundred and twentyeight break on the tympanum every second, the note has a fixed pitch, called in music " C natural." If the waves come faster than this, the pitch is higher, and if less rapidly the pitch is lower. What we are all familiar with as a pitch of a musical note depends, then, on the rapidity with which the waves of sound strike the ear, and may evidently be measured by the number of waves breaking on the tympanum in a second. Our ears are so constituted that they can hear a musical note only when within certain fixed limits of pitch, differing to a slight extent with different individuals. The deepest bass note, which can be heard, as such, by a good ear, is produced by about eight waves in a second. If the waves strike less rapidly than this, they are perceived as distinct beats, and beginning at this note the musical scale ascends to a note caused by twenty-four thousand waves a second, which is the highest note perceptible by human sense. The range of a piano generally extends from a note produced by sixteen waves in a second, to one caused by one thousand and twenty-four waves in a second, as is shown by the accompanying table. Sounds of the highest pitch, like the cry of some insects, become disagreeable, and by some persons cannot even be distinguished. It is quite possible to produce a sound, which, though painfully shrill to one person, shall be entirely unheard by another. WAVES OF LIGHT. 4I Professor Tyndall, in his very interesting work on the glaciers of the Alps, relates an instructive anecdote of this sort, which I give in his own language. " I once crossed a Swiss mountain in company with a friend ; a donkey was in advance of us, and the dull tramp of the animal was plainly heard by my companion ; but to me this sound was almost masked by the shrill chirruping of innumerable insects, which thronged the adjacent grass ; my friend heard nothing of this, it lay quite beyond his range of hearing.** There may, therefore, be innumerable sounds in nature to which our ears are perfectly deaf, although they are the sweetest melody to more refined senses. Nay, more, the very air around us may be resounding with the hallelujahs of the heavenly host, when / our dull ears hear nothing but the feeble accents of i _pur broken prayers. ^ We have been studying, my friends, the nature of sound, in order to comprehend more readily the nature of light and heat, for the phenomena included under these names are produced, like the phenomena of sound, by waves ; not, however, by waves in the air, but by waves in a medium which is as much more subtile than air as air is more subtile than water, — indeed, a medium so exceedingly thin that it eludes all our powers of chemical analysis ; but which, as we assume, pervades all space, and this, too, whether the space be filled or not, at the same time, by other forms of matter. We call this medium '* ether,'* and through it the waves of 42 CAUSE OF COLOR. light speed with an inconceivable rapidity. Sound travels i,ioo feet in a second, but a wave of light spans 187,000 miles in the same time, and starting from the sun on its journey of unnumbered years, to Sirius or Arcturus, leaves the whole solar system behind in a single hour. Yet great as is the difference of velocity, the analogy between sound on the one side, and light or heat on the other, is complete. Every luminiferous body, like this candle-flame, excites in the tenuous ether a system of waves, which spread, in ever- enlarging spheres, with the immense velocity just described ; and it is these little billows which, passing through the humors of the eye, and breaking on the retina, produce the sensation we call light, or, falling on the skin, excite the less delicate nerves of feeling, and cause the sensation of heat. Moreover, the difference between colors is of precisely the same kind as the difference between notes. Red, yellow, green, blue, violet, etc., are names we give to sensations caused by waves of ether breaking at regular intervals on the retina. Color corresponds to pitch, and — what may seem to you incredible — we are able to calculate from actual measurements the number of waves of ether which must break on the retina in a second in order to produce the sensation of a given color. Here are some of the numbers, and, extravagant as they appear, they are the sober results of science, and have been as accurately determined as the magnitudes and distances of astronomy. Violet 57,000 699 It is actually true, that when we are receiving the sensation of red there are no less than 477 million millions of ether waves breaking on the retina of our eyes every second. And more than this, we have measured the length of these waves, and we know that the length of a wave of red light from crest to crest is -j^^oo ^^ ^^ i^^h. By examining the table you will also discover that the sensation of red, as compared with other colors, results from the smallest number of waves, and that these waves are comparatively large. On the other hand, the sensation of violet is caused by the largest number of waves, which, however, are proportionally small in size. The red light, therefore, corresponds to low, * A given wave-length corresponds to each point on the line of the solar spectrum, to be described further on. The numbers given in the table are to be regarded merely as the mean values for each color, measured at points on the spectrum, marked by certain prominent dark lines called Frauenhofer's lines. The solar spectrum, as seen with a powerful spectroscope, is crossed by thousands of these lines, which have a fixed position, and therefore serve to mark definite points on this otherwise continuous band of blending colors. 44 THE SOLAR SPECTRUM. and the violet to high notes of music, and between these extremes there exists every gradation of pitch which is here manifested in color. Waves of all the dimensions given in the table, together with waves of every possible length between certain extremes, — which are far wider than those indicated above, — move together in the sunbeam, and their combined impression produces the sensation of white light. We have a very simple way of analyzing the sunbeam and separating its different color-producing waves. The method consists in passing the sunbeam through a glass prism. The prism has the power of bending the beam from its rectilinear direction ; but it does not change the direction of the motion of all the waves to the same extent. The longer waves, which give the sensation of red, are bent from their course much less than the shorter waves, which produce the sensation of violet, while waves of an intermediate length take a course between the two. Hence, after emerging from the prism the directions of the different waves diverge, and if we receive the beam of light thus analyzed, on a screen, the various color-producing waves strike the screen at different points of a continuous line. A more or less narrow band on the screen will thus be illuminated with lights of different colors in the following order — Red, Orange, Yellow, Green, Blue, Indigo, Violet — and this beautiful phenomenon is familiar to almost every one under the name of the solar spectrum. COLOR AND MUSICAL NOTES. 45 becomes still more evident. As there are persons who cannot hear the shrill sound of some insects, so there are many who cannot see certain colors of the spectrum, and as there are unquestionably innumerable sounds in nature which are inaudible to our ears, so there are innumerable waves in the ether which are powerless to produce the sensation of light. Moreover, singular as it may seem, we have more palpable evidence of the existence of these non-luminiferous waves than we can obtain in the case of sound. There are waves in the ether far smaller, and undulating far more rapidly, than those which produce violet light ; so small that they do not even jar the nerves of the retina, but which, nevertheless, breaking on the prepared plate of the photographer, leave there an impression which, developed by his skill, becomes a beautiful copy of nature or of art. On the other hand, there are waves in this same ether so large that the delicate retina cannot vibrate in unison with their rough beats, but which, nevertheless, breaking on the surface of the skin, disturb the coarser nerves of feeling, and produce the glow of heat. Most of the waves which impress the optic nerve will also affect the nerves of feeling ; but the reverse is not true, for many of the waves which produce the sensation of heat are far too large, and undulate too slowly, to set in vibration the retina of the eye. I hope that I have been able to make clear two points, — first, that light and heat are forms of motion ; second, that the differences in the phenomena which have been referred to these two agents are simply different sensations or different effects'^ produced by the same wave-motion. It would be highly interesting, in this connection, to examine the wonderfully delicate adjustments and to follow out the peculiarly intricate motions which concur to produce the phenomena of light and heat ; for they are in themselves most striking illustrations of the wisdom of the Creator. But this w^ould lead us too far from our proposed plan, and I must content myself with the few facts already given, which were necessary to illustrate the relations of the atmosphere to the thermal conditions of our globe. From the principles stated, it is evident that the atrnosph^erejiiust act in diffusing heat, just aswejiai^^ seen that it acts^ in diffusing light. Indeed, this effect is one of the thousand conditions on which the existence of organic life depends. Were it not for the influence of the atmosphere, the greatest extremes of temperature would be produced by the alternation of day and night, and even were the * The effects of expansion, melting, evaporation, the permanent elasticity of gases and vapors, and many other phenomena, formerly referred to the action of a peculiar agent called heat, are now supposed to be the result of the motion which the ether-waves communicate to the material particles of the bodies on which they strike or through which they are transmitted. To understand this, we must remember that the molecules, even of the densest solids, are supposed to be separated from each other by comparatively large spaces filled with ether, through which the waves of heat and light may move more or less freely, just as the waves of air pass between the branches in a forest. Moreover, as the waves of air impart motion to the branches of the trees, and afterwards are kept in motion by the waving boughs, so also the material particles of a body may set in motion the waves of ether, or receive motion from them in return. density of the atmosphere reduced only one-half, the variation would be so great as to render the existence of the higher forms of organic life impossible, except, perhaps, in the more favored regions of the earth. But not only does the atmosphere diffuse the heat of the sun's rays, it also acts, and even more effectually, in retaining on the surface the heat which the earth is constantly receiving from that great central luminary. The atmosphere has been compared to a mantle, and the comparison is just ; for, like a huge cloak, it envelops the earth in its folds, and protects it from the chill of the celestial spaces through which we are rushing with such frightful velocity. In order to understand how a thin and transparent medium like air can thus act to keep the earth warm, we must recur to some of the facts established above. As the ether-waves, breaking on the eye more or less rapidly, produce the different sensations of color, so when breaking on the skin they occasion analogous differences in the sensation of heat, which, although not so accurately distinguished, because the sense is less delicate, nevertheless are as real as the difference between a low and sweet musical note, and one that is high and shrill. There are waves of heat which break upon our nerves of feeling like the shrill cry of the cricket on the ear, and seem to penetrate to the very brain, while there are others which fall like the low tones of an organ, diffusing throughout the system a genial glow. Such, for example, is the difference between the heat from a hard-coal fire and that from a steam radiator. The waves of the first sort, from their small size and rapid motion, can readily pass through glass and other transparent media, when the large waves with their slow motion are in a great measure stopped. Now it is found that the sunbeam is chiefly made up of waves of the first class, which are therefore able readily to penetrate the atmosphere and warm the surface of the earth. The earth thus warmed becomes itself a hot body, surrounded by an intensely cold space, and, like anvotherhot body, tends to lose its heat by radiation. /jBut the waves of heat which the earth^ sets in motion are of the second class, long and slow undulations, and these are in great measure arrested by the atmosphere; indeed, as experiments have proved, they are chiefly absorbed by the lower strata,f in which we live and move. Thus it is that the atmosphere keeps us warm ; and if you desire further proof of the correctness of these experimental deductions, ascend any high mountain, and, as the thickness of the aerial covering above you is diminished by the elevation, you will find that the chill increases, vegetation slowly disappears, and before long you will reach a region of eternal snow and ice. It is true that there are other causes acting to lower the temperature at high * The pitch, if we may so speak, and penetrating power of the heat-waves depend on the temperature of the body by which they are set in motion, and in proportion as the temperature rises the pitch is higher and the penetrating power greater. f Professor Tyndall has shown that this effect is due almost entirely to the aqueous vapor in the atmosphere, which is present in greatest quantity in the strata nearest to the earth. A TRAP TO CATCH THE SUNBEAM. 49 elevations, but the one just noticed is by far the most important, as well as the primary cause. The effect of the atmosphere is precisely similar to that of the glass panes of a hot-house. The glass, like the atmosphere, allows the rapidly undulating waves of the sun to pass,* but almost "entirely arrests the large and slowly undulating billows which radiate from the vegetation within. They are each, in fact, a trap to catch the sunbeam. The atmosphere not only thus acts in diffusing the sun's rays, and retaining the heat which they bring to us, but it also subserves an equally important end in distributing their genial warmth over the whole surface of the earth, thus moderating the climate of the temperate zone, and mitigating the intense heat of the tropics. Air, like all gases, is expanded by heat, and thus rendered specifically lighter, and on this simple principle all our methods of warming and ventilating are based. When now it is remembered that the atmosphere under the tropics must become more intensely heated by the vertical rays of the sun than it is in the temperate zones, the result will be obvious. The heated air. rises, and the cold adr rushes in from the North and South to take its place. Thus, two general currents are excited in the aerial ocean of each hemisphere, one on the surface of the earth, tending towards the * In the sunbeam, as it passes through space, there are undoubtedly waves of low pitch in abundance, but these are almost entirely arrested by the atmosphere before reaching the surface of the earth. It has been estimated that of the heat the earth receives from the sun about one-third is thus absorbed. 50 DISTRIBUTION OF HEAT. equator, and another, higher in the atmosphere, tending towards the poles. These currents, however, do not blow due North or South ; for many causes combine to turn them from their primitive directions. In the first place, the rotation of the globe on its axis imparts to objects on the surface a motion from West to East, varying in velocity from nothing, at the poles, to the speed of a cannon-ball, at the equator. In consequence of this, a mass of air moving towards the equator is constantly arriving at a point on the surface of the earth, which is moving towards the East more rapidly than the point it has just left ; and as, in virtue of the law of inertia, the moving mass cannot accommodate itself instantaneously to the increased velocity, it is left a little behind, — that is, a little to the West, at every step. Hence, the lower or polar currents bend more and more towards the West as they approach the equator, acquiring in the northern hemisphere a south-westerly, and in the southern hemisphere a north-westerly direction ; and the currents of the two hemispheres, meeting at the equator, combine to produce the great trade-wind, which, in the Pacific Ocean, blows constantly from the East to the West, and would blow regularly in this direction all round the globe if the continents did not intervene to disturb its course at various points. The effect of the earth's rotation on the current of warm air which flows from the equator in the upper atmosphere, must evidently be the reverse of that just described, bending it constantly to the East, and giving to it in the northern hemisphere a north-westerly, and in the southern hemisphere a south-easterly, direction. But the upper and lower currents do not long retain this relative position ; for, as the first comes northward, it gradually sinks, and, long before reaching this latitude, touches the surface of the earth. Then, of course, it comes in collision with the current from the North, and here a strife for the mastery ensues. Sometimes the one and sometimes the other prevails, and this alternating ascendency is one of the chief causes which render the winds of temperate climates so irregular. Again, the unequal heating effect of the suns rays on the earth, as compared with the sea, combined with the irregular distribution of land and water over the surface of the globe, tends to complicate still further the motion of the aerial currents. For reasons which will hereafter appear, the land is more quickly heated by the suns rays than the sea, when under the same conditions, and, on the other hand, as soon as the sun is withdrawn, it cools more rapidly. Hence, on an island in a warm climate we generally have, during the daytime, a current of heated air rising from the surface of the earth, and a current of cooler air flowing in on all sides from the ocean to take its place, while after sunset the land soon cools below the temperature of the surrounding ocean, and the current is reversed. Thus is produced the daily alternation of land and sea breezes, so familiar to every one who has visited the tropics, where the phenomena are most strongly marked. 52 MONSOONS. Quite a similar reciprocal action between the continents and the great ocean is caused by the alternation of seasons, and of this the monsoons of the Indian Ocean are a remarkable illustration. This mediterranean ocean, shut off from the influence of the general trade-winds by the great continental masses which surround it, has a system of aerial currents, peculiar to itself, blowing six months of the year in one direction and six months in the other. These are set in motion by the unequal heating of the continents of Asia and Africa during the extreme seasons. In the months of December, January, and February, the part of Africa south of the equator is exposed to the vertical rays of a summer's sun, while the countries of southern Asia are feeling the comparative cold of their winter. The natural consequence is, that a stream of cold air rushes across the Indian Ocean to feed the intenselyheated current which is rising over the burning plains of Africa, and produces a strong north-easterly breeze, which is the winter monsoon of India. When, however, the sun comes north of the equator, all these conditions are reversed. The ocean air now rushes to the more heated plains of India, and tlie summer monsoon sets in, which blows from the south-west, the change from one to the other being always attended by variable winds and furious storms. Lastly, the position of mountain chains and the configuration of the continents, which break and turn the winds, or open to them a freer channel, have an important influence in determining the direction of the aerial currents on the earth. AERIAL CURRENTS. S3 But we have not time for further details ; they are given in all works on physical geography,^ and the student of natural theology will find that subject rich in illustrations of God's wisdom and power. We have already become sufficiently acquainted with the general plan to understand how the atmosphere acts in equalizing the climate of the globe. The aerial currents which come to us from the South bring with them the heat of the tropics, and distribute it over the temperate zone. As they blow from the south-west, they naturally exert the greatest heating power on the western coasts of the continents, and this is one great cause of the well-known fact that the climate of western Europe is so much milder than our own, and the climate of California and Oregon so much warmer than that of the corresponding latitudes on the eastern coast of Asia. Moreover, the sea-breezes on islands and along seacoasts, the monsoons of the Indian Ocean, and other local currents, all combine, as our theory shows, to produce the same general result, cooling such regions of the earth as from any cause have become overheated, and transferring the warmth to places where it is more needed. Just as the heat of burning fuel is diffused over a whole building from the furnace by the currents of air it sets in motion, so the sun's heat is diffused over the earth from the tropics by the great terrestrial currents we have so briefly described. Indeed, as already stated, in all our methods of heating, we merely apply, on at work around us in the atmosphere. But, although the heat of the sun might set in motion these aerial currents, they would have but little effect in warming our northern climate, were it not that the air has been endowed with a certain capacity for holding heat. All substances possess this capacity to a greater or less degree, but the differences between them are very large. Thus the amount of heat required to warm a pound of water is ten times greater than would be required to raise the temperature of a pound of iron, and thirty times greater than would be required to raise the temperature of a pound of mercury to an equal extent. Hence, under the same conditions, a pound of water may be said to contain ten times as much heat as a pound of iron, and thirty times as much as a pound of mercury ; or, again, in other words, the capacity of water for heat is ten times greater than that of iron, and thirty times greater than that of mercury. The capacity of air for heat is, weight for weight, about twice as great as that of iron, and although only one-fifth as great as the capacity of water, it is yet greater than that of most other substances. . The point, however, to which I wish to direct your attention, is the fact that this capacity is exactly adjusted to the office which the air has been appointed to filL Were the capacity of the air less, the hot air from the tropics would bring to us proportionally less heat ; were it greater, the reverse would be the case ; and in either event, the distribution of temperature on the earth would be changed. To what extent such a change would affect the general welfare of man, it is impossible to determine ; but when we consider how far the history of man has been influenced by climate, it will appear that the present distribution of the human race — the existence, for example, of a large and influential city in this place — may be said to depend on the adjustment of the capacity of the atmosphere for heat ; and yet it depends no less on ten thousand other conditions, many of them far more important than this. How truly, then, it may be said, that even here on earth we live in '^ a city which hath foundations, whose builder and maker is God '* ! Such are a few of the more obvious marks of design, which may be discovered by studying the relations of the atmosphere to light and heat. I might here close one division of my subject ; but I should fail to give you an adequate idea of the wonderful play of physical forces in the atmosphere, were I to leave out of view that mighty agent which charges the artillery of heaven and feeds the flaming torches in the northern sky. It is true that the atmospheric relations of electricity are very imperfectly understood, and the important ends which it undoubtedly subserves in the economy of nature almost entirely unknown. We cannot, therefore, expect them to furnish us with many additional illustrations of the Divine attributes ; but since electrical phenomena play so conspicuous a part in the atmosphere, and must have been included in its plan, they certainly should not be overlooked if we whole design. Of all the assumed agents of nature there is hardlyone which is so little understood, and yet has been so carefully studied, as electricity. To the uneducated it affords the convenient explanation of most obscure phenomena, while with men of science it is the object of much laborious investigation and careful theorizing. The study of its phenomena has been fruitful in the discovery of facts ; but it has as yet led to but few general principles, and has furnished only a meagre explanation of those grand displays of nature in which it seems to be such an important agent. In regard to the nature of electricity, we are entirely ignorant. The phenomena of light and heat* admit, to say the least, of an intelligible explanation, and can be referred to a dynamical origin ; but in the case of electricity we are obliged to be content with collecting facts, and must await the further progress of science to reveal the now hidden cause. I am well aware that electricity has been regarded as a very rare and subtile " fluid,'* and that this theory has not only afforded a plausible explanation of most of the phenomena of statical electricity, but also that the numerical results based upon it have been most remarkably verified by experiment. Yet nevertheless, although the theory may still be used as a convenient frame in which to exhibit the facts, there are but few investigators of the present day gether as utterly untenable. The fundamental facts of electricity were known to the ancients, and are familiar to every one. If a stick of sealing-wax or a glass tube be rubbed with a warm silk handkerchief, it becomes, as we say, electrified, and in this condition has the power of attracting pieces of paper or any light particles of matter. When the scientific men of the last century came to examine these phenomena more carefully, they found that the handkerchief was also electrified, and thrown into a state differing from that of the glass in the one case, and that of the resin in the other, very much as the north pole of a magnet differs from its south pole. They found, also, that the resin was electrified oppositely to the glass, and they hence concluded that there were two kinds of electricity, which they distinguished by the names resinous and vitreous, or positive and negative. They also discovered that this agent could readily be drawn off from electrified bodies by the metals, but only with difficulty, if at all, by such materials as india-rubber, glass, resin, or silk, and they were hence led to divide substances into conductors and non-conductors of electricity. A good conductor, when insulated by non-conductors, was found to retain for a short time the electricity it had received from the electrified glass or resin, although the charge was soon dissipated by the surrounding air, especially when moist. By bringing in the aid of machinery, and thus increasing the surface of fric3* S8 FUNDAMENTAL FACTS. tion, it was found possible to enhance very greatly the effects obtained with a glass tube ; and this was the origin of the electrical machine. This familiar instrument is merely a mechanical contrivance for rubbing together glass and silk, with two insulated metallic conductors for receiving the two kinds of electricity thus generated. If the hand or a metallic knob was brought near the prime conductor of the machine when highly electrified, it was found that a luminous discharge followed, which was termed an electrical spark ; and it was found possible by means of a glass vessel, coated inside and outside with some metallic leaf, called a Leyden jar, to accumulate the two electricities in such large quantities that, when allowed to flow together, the discharge was capable of producing violent mechanical action, similar to that of lightning, although on a vastly reduced scale. It was also discovered that electricity passes readily through the greatly rarefied atmosphere in the receiver of an air-pump, causing a luminous effect similar to the aurora borealis. Lastly, it was observed that electricity readily escapes into the atmosphere from a pointed conductor, and, conversely, that a heavy charge can be silently and harmlessly drawn from an electrified body by holding near it the point of a needle. By attaching a pointed conductor to a boys kite, Franklin succeeded in drawing an electric spark from a thunder-cloud, and having thus established the identity between atmospheric and frictional electricity, he erected the pointed rod, which protects our dwellings against the lightning s stroke. More recently it has been discovered that friction is by no means the only source of electricity, and it seems probable that no change^ either chemical or physical, takes place in nature without some manifestation of this agent. It was at first supposed that there were several kinds of electricity, which w^ere named thermo-electricity, magneto-electricity, voltaic electricity, and animal electricity, according to the nature of the process in which the electrical action was developed ; but it is now universally conceded that all are only different manifestations of the same agent, and most investigators believe that electricity will in time be shown to be a form of molecular motion analogous to that which produces the phenomena of hght and heat, although it has not as yet been found possible to frame a comprehensive and intelligible theory based upon this hypothesis. Again, it has been found that friction is a far more general source of electricity than was at first believed. In fact, electrical phenomena appear to be a constant result of friction, whatever may be the nature of the substances rubbed. Thus it is developed by blowing air over glass, and the hydro-electric machine, one of the most effective means of generating electricity we possess, owes its surprising energy to the friction of globules of water against the sides of the vent-cock of a steamboiler."^ When, now, we consider that the air is always This machine consists simply of a small steam-boiler insulated on glass pillars, having a peculiarly-constructed vent-cock and provided with suitable metallic conductors for receiving the electricity. The 6o ATMOSPHERIC ELECTRICITY. rubbing over the surface of the earth, at times with great rapidity, we shall not be surprised to learn that both bodies are constantly in an electrified condition, the earth being generally charged negatively, and the atmosphere positively. Even in fair weather it is always possible to detect the presence of free electricity in the atmosphere ; and during a storm, when clouds filled with drops of water are hurried over the surface, grinding against the hills and the trees, or against each other, the atmosphere becomes a vast hydro-electric machine, whose sparks are the lightning, and the noise of whose discharges the thunder. Again, the various chemical and physical changes which are going on around us, — such as the vital processes of animals and plants, the combustion of fuel, volcanic action, the evaporation of water, — all undoubtedly add to the electrical excitement of the atmosphere, and more or less modify the result. It is not important for us, however, to study the action of each one of these causes ; for we have, probably, in the friction of moist air driven by the winds, the chief source of atmospheric electricity ; and when we consider the amount of friction which must attend the rapid motion of storm-clouds, or of a tori^ado through the atmosphere, the wonder is, not that an occasional thunderbolt should kindle a conflagration, or even cause a death, but that every storm does not lay waste the earth along its fiery track. Moreover, steam, as it escapes under high pressure, becomes filled with globules of water which rub against the sides of the vent-tube, and this is so shaped as to facilitate their formation. PROTECTION AGAINST LIGHTNING. 6l when we appreciate the vastness of the scale on which the electrical machine of nature is constructed, the thunder-storm ceases to surprise us, and only calls our attention to those beneficent provisions by which we and our race are saved by a constant miracle from the fate of the cities of the plain. That the atmospheric electricity was designed to subserve many important and beneficent ends, the whole analogy of nature compels us to believe ; but while our present ignorance conceals them from our sight, we may still discover evidence of God's goodness and wisdom in those simple provisions by which the atmosphere is preserved from violent or frequent electrical excitements, and its charge drawn down harmlessly to the earth. Since the atmosphere is, at best, a very poor conductor, the electricity developed by the processes just considered tends to accumulate ; and under peculiar conditions the clouds may become so highly charged, that at length the pent-up power acquires sufficient force to break through all barriers, and the lightning dashes to the earth, crashing, rending, and burning on its way. To guard his roof from its destructive action, man erects the lightning-rod, whose bristling points quietly drain the clouds, or, failing to do this, receive the charge, and bear it harmlessly to the earth. But ages before Franklin pointed the first rod to the storm, the Merciful Parent of mankind had surrounded the dwellings of his children with a protection far more effectual than this; for, since jdie creation of organic life, every pointed leaf, every twig, and every blade of grass has been silently disarming the clouds of their destructive weapon. It is difficult to improve upon nature, and man constantly finds that in his best inventions he hasTieen anticipated from eternity by an Inventor greater than himself. So, not long after Franklin had discovered the efficacy of metallic points in dissipating charges of electricity, and had applied the principle in constructing the lightning-rod, it was found that a common blade of grass, sharpened by nature's exquisite workmanship, was three times as effectual to the end in view as the finest cambric needle, and a single twig far more efficient than the metallic point of the best-constructed rod. When, now, you reflect how many thousands of these vegetable points every large tree directs to the sky, and consider what must be the efficacy of a single forest with its innumerable twigs, or of a single meadow with its countless blades of grass ; when you remember that these are only subsidiary to those vast lightning-conductors the mountain-chains, whose craggy summits pierce the clouds themselves ; and still further, when you learn that rain-drops and snowflakes also have been made good conductors, so that during storms a natural bridge for the lightning reaches across from the clouds to the earth, you will see how abundant the protection is, and with what care Providence has guarded us from the destructive agent. It is only under unusual circumstances, when electricity is developed more rapidly than it can be dissipated through these numberless channels, that a violent discharge takes place, and if then it tears, burns, or kills, it also reveals the MARKS OF DESIGN. 63 Merciful Hand which constantly spares. Moreover, through this servant of his pleasure, God is constantly educating and elevating his creatures. In the wild coruscations of the lightning, and in the reverberating roll of the thunder. Nature exhibits one of her grandest aspects, and when, through the cold, dry air of the polar region the electric charges shoot down to the earth in tremulous flashes, we see her lighting up those grand displays of northern fire which enliven the long night of the arctic winter, or in this more favored climate excite the admiration of all.^ I must here conclude this very imperfect sketch of the physical adaptations of the atmosphere to the ends it subserves on the earth. We studied in the first place its aeriform condition, and found that its density not only formed an essential part of the scheme of organic nature, but also was closely related to the dimensions of the solar system. In this Lecture we have studied the relations of the atmosphere to light, heat, and electricity ; and although we have been able only to glance at some of the more prominent features in these wonderful displays of . creative energy, we have found, wherever we turned, abundant illustrations of the wisdom, power, and goodness of our God. I trust that you have been impressed by the vastness, the complexity, and yet I am indebted for many of the above illustrations to an admirable paper on atmospheric electricity, in the American Almanac for 1854, by my friend and colleague Prof. Joseph Lovering. the simplicity and harmony of the whole design, for these are the chief points which I have endeavored to set forth. But oh how imperfect any conception which I can give you must be ! This atmosphere is sustained in the proper working of all its parts only by the exact balancing of a thousand conditions. Attempt to make yourself acquainted with these conditions, and, disregarding those which you recognize at once as surpassing human intelligence, study only such as are thoroughly understood and universally admitted to have been primary conditions in the plan of nature before the atmosphere could exist as it is. This is not an impossible task. It would require years of study and it would lead you into every department of physical science, but the result would well repay your labor. You would find it easy to follow out any one line of the conditions, until it became lost in the obscurity of the unknown ; but to form an adequate conception of the simultaneous working of all the conditions in their varied bearings, or even of two or three of them, you would soon discover to be a hopeless task. The complication of this wonderful machinery so far transcends man's insight, that to understand its combined action is simply impossible. But although thus made keenly sensible of the limits of human thought, you would be filled with gratitude for the high privilege enjoyed of studying the divine mechanism, even though you understood its workings only obscurely and in part. concerned, the analogy is perfect. We must never forget, however, that there is an essential difference between the scheme of nature and the most complicated human mechanism. I have seen a carpetloom weaving a pattern composed of twelve different colors, and, as I watched the shuttles of various colored yarns which were selected by the hands of the machine with unerring certainty, and thrown through the warp, it seemed as if the very iron were endowed with intelligence, and the impression was one of wonder and bewilderment. To comprehend such complexity appeared impossible ; but the more I studied the details of the machine, the more thoroughly I understood the mode of its action, until at last the wonder vanished; and although not ceasing to admire the skill of the inventor, I felt that I had comprehended the whole, and could even conceive of the mental process by which such a wonderful combination of means had been thought out and adjusted to produce the desired end. The artist was ingenious, but the machine was still human. How different it is with the mechanism of nature! Here, also, it is true, the more we study, the more we understand the workmanship ; but then we never reach the limit. The more our powers of thought and observation are developed, and the more our experience is enlarged, the more the field of possible knowledge expands before us. The larger our attainments, the less we seem to know. telligence in the design, but it is no longer a fathomable intelligence ; we feel that it is infinitely above us : in a word, we feel that it is God. Would that my feeble language might convey to you the full power of this impression ; for until one has become conscious of the infinite beauty and skill with which the numberless parts of nature have been fashioned and adjusted, one cannot appreciate the force of the conviction which the impression gives. We may make ourselves familiar with the dimensions of Mont Blanc ; we may read the most glowing descriptions of this " monarch of mountains," heightened by all the arts of eloquence or of poetry ; we may cross the ocean and travel to the beautiful valley of Chamouni at its base ; we may even climb its side, study its glaciers, and cross its fields of snow : but we can form no adequate conception of its grandeur, until, ascending one of the lofty mountainpeaks which surround it, we see its summit still towering above our heads, apparently higher than before. So it is in the study of nature. No description can convey an adequate conception of the impression which it leaves upon the mind. It is not until the student, after long study, has become thoroughly acquainted with some one portion, however limited, of its wonderful economy, that he begins to appreciate the perfection of its parts, the infinite skill with which all have been adjusted, and the true grandeur of the w^hole. By most men these heights of knowledge are unattainable. Why, then, should we hesitate to receive the evidence of a philosopher like Newton, who. after spending a long life in the investigation of nature, and with a success unparalleled in the history of science, uttered this memorable sentiment shortly before his death : ^^^ I do^or~1mow whM I rhay pear to the world ; but to myself I seem to have been only like a boy playing on the sea-shore, and devoting myself now and then to finding a smoother pebble or a prettier shell than ordinary, while the great ocean of truth lay all undiscovered before me." j I know this sentiment has been so many times repeated as to seem trite, but, coming from whom it does, it cannot be too often quoted. It is the testimony of the foremost master of science to its greatest and sublimest truth. We can all recognize the marks of design in nature, and when we add to this evidence of our senses the testimony of a man like Newton, who assures us that the more our powers are enlarged, and the wider our knowledge becomes, the grander and vaster the design will appear, until it surpasses all our powers of thought or imagination, we begin to feel the full depth of the truth I have been endeavoring to enforce. If our minds are incapable of comprehending the plan, who could have been equal to the design ? " Whence, then, cometh wisdom, and where is the place of understanding, seeing it is hid from the eyes of all living, and kept close fromthefowlsof the air? "^ ^ ^ God understandeth the way thereof, and he knoweth the place thereof. For he looketh to the ends of the earth, and seeth under the whole heaven, to make the weight for the winds ^ * -^ and a way for the lightning of the thunder. Then did he see it and declare it; he prepared it, yea, and searched it out. And unto man he said, Behold the fear of the Lord, that is wisdom, and to depart from evil is understanding," TESTIMONY OF OXYGEN. Were we to limit our regards to those physical qualities of the atmosphere which we studied in the first two chapters, we should overlook the most wonderful adaptations in its divine economy. These properties belong to the atmosphere, in great measure at least, in virtue of its aeriform condition, and, so far as we know, an atmosphere composed of other gases, and still having the same density, would soften the intensity of the light, and diffuse the genial influences of the sun's heat, as well as air. Not so, however, with the chemical qualities of the atmosphere, which we are next to consider. These belong to the atmosphere solely as air, and could not have been obtained with any other known materials. When a chemist wishes to investigate the nature of a new substance, his first step is to analyze it. Let us, therefore, as a preliminary to our present inquiry, ascertain what is the composition of this aeriform matter we call air. The air has been analyzed hundreds of times in every latitude and in every climate ; and the result has been uniformly that which is given in the following table : — Besides oxygen and nitrogen gases, which, as you will notice, are the chief constituents, there are always present in the atmosphere the vapor of water, carbonic dioxide, and ammonia gas ; and if we add to these uniform constituents the various exhalations constantly arising from the earth, we shall have as accurate an idea of the composition of the air as chemistry can give. While, however, the proportions of oxygen and nitrogen are almost absolutely constant, those of the other ingredients are very fluctuating, and the total quantity exceedingly small, never amounting in all, exclusive of aqueous vapor, to more than one part in a thousand, unless in some confined locality, and under very unusual circum- stances. Do not, however, measure the importance of these variable, and in a degree accidental, constituents by their amount, for, although present in such small quantities, they are not less essential in the atmosphere than the two gases which make up almost its entire mass. Moreover, we must carefully avoid the error of considering air as a distinct substance, like water or coal. On the contrary, it is merely a mechanical mixture of its constituent gases, and is in no sense a definite chemical compound. Indeed, we may regard the globe as surrounded by at least three separate atmospheres, — one of oxygen, one of nitrogen, and one of aqueous vapor, — all existing simultaneously in the same space, yet each entirely distinct from the other two, and only very slightly influenced by their presence. To each of these atmospheres the Author of nature has assigned separate and different functions. They are like so many servants in a household, each with a distinct set of duties, which are discharged with a fidelity and diligence unknown to any earthly service. Let us consider what those duties are, and see how skilfully each is adapted to the offices which it is designed to fill. Were all the other constituents of the air removed, the earth would still be surrounded by an atmosphere of oxygen, having about one-fifth of the density, and exerting at the surface of the globe about one-fifth of the pressure, of the present atmosphere. In studying the chemical relations of air, let us begin with some of the more succeeding chapter. It is easy to prepare oxygen in a pure state. It is then a perfectly colorless and transparent gas, and so persistently does it retain its aeriform condition that it cannot be reduced to the liquid state by pressure alone. A German chemist, Natterer, submitted this gas to a pressure of over forty-five thousand pounds, or twenty tons on a square inch, but he did not succeed in changing its condition. More recently, by the combined action of great pressure and the most intense cold which can be artificially produced, all the gases formerly called permanent have been liquefied, and oxygen among the number. But this remarkable result, while it shows conclusively that the so-called permanent gases differed from other forms of aeriform matter in degree only, and not in kind, also brings into prominence the extreme qualities of these constituents of our atmosphere. Most aeriform substances may be reduced to liquids by pressure under a very moderate reduction of temperature ;"^ but oxygen * For every aeriform substance there is a fixed temperature above which the gas cannot be reduced to a liquid" by any pressure, however great ; but below which this change can be produced if the mechanical force is sufficient. This fixed temperature is called ** the critical point," and the pressure required to condense a gas becomes less and less as the temperature is reduced below this point, which differs very greatly with different substances. The critical point of many of the known gases is above the ordinary temperature of the air, and a,U such gases may be reduced to liquids simply by mechanical on the earth. The importance of this fact will be seen at once on comparing the condition of the oxygen and nitrogeiTm The atmosphere with that of the aqueous vapor. A fall of temperature of only a few degrees will generally condense a portion of the vapor, and, small as is its relative amount, the resulting rain is at times poured down upon the earth in deluging floods ; and if you consider what must have been the destructive results had the whole mass of the atmosphere been liable to a similar fluctuation, even under extreme conditions, you will discover in the permanency of oxygen a most obvious adaptation of its properties to the thermal condition of our globe. The permanently aeriform state of oxygen will appear still more remarkable when we consider how largely it enters into the composition of the solid crust of the earth. Oxygen belongs to that class pressure. The critical point of carbonic dioxide gas is about 88°, and as this temperature is within the limits of the variations in our climate, carbonic dioxide furnishes the most convenient illustration of the principle we are discussing. For example, in some specimens of granite rock we find cavities which are filled with liquid carbonic dioxide if the temperature is below 87° — as can readily be seen by examining with a microscope the thin sections prepared for this purpose — but when the temperature rises above 87° the liquid at once disappears, to condense again, however, as soon as the temperature falls. The critical points of oxygen and nitrogen are not exactly known, but must be more than 150® below the zero of Fahrenheit, and hence chemists did not succeed in condensing these gases to liquids until they submitted them to extreme cold as well as to great pressure. 74 PERMANENT AERIFORM CONDITION. of substances which the chemists call elements, because they have never succeeded in resolving them into simpler parts, and of all the elements it is by far the most widely diffused. As we have already seen, one-fifth of the volume of the atmosphere consists of this gas ; but this is a small amount compared with that which enters into the composition of most substances. You may be surprised at the statement, but it is nevertheless true, that between one-half and one-third of the crust of this globe and of the bodies of its inhabitants consists of oxygen. No less than eight-ninths of all water is formed of the same gas. It makes up three-fourths of our own bodies, not less than four-fifths of every plant, and at least one-half of the solid rocks. Remembering now that twenty tons of pressure on a square inch are not sufficient to reduce oxygen to a liquid condition, consider what must be the strength of that force which holds it thus imprisoned. In a tumbler of water there are no less than six cubic feet of oxygen gas, condensed to a liquid condition, and held there by the continuous action of a force which can be measured only by hundreds of tons of pressure. We call the force chemical affinity; but who shall measure its power? Who but He who could make with such a subtile material the rocks, with which he " laid the foundations of the earth," and the waters which roll over its surface? Oxygen gas, like all other forms of aeriform matter, tends to expand, and can be prevented from obeying this natural tendency only by en- closing it in an air-tight receiver. As it exists in our glass jars, under the ordinary conditions of temperature and pressure, one cubic foot of oxygen weighs 590.8 grains, although in its more expanded state, as it exists in the atmosphere at the surface of the globe, it has but one-fifth of this density. One cubic foot of nitrogen gas weighs, under the same circumstances, 517.5 grains; but although there is such a decided difference between the specific gravities of the two gases, yet so perfectly are they mixed together throughout the whole extent of the atmosphere, that analysis has been unable to detect more than a very slight difference in composition between the air brought from the summits of the Alps and that from the deepest mine in Cornwall. Why, you may ask, do not these gases obey the well-known laws of hydrostatics, the heavier oxygen sinking to the surface of the earth, and the lighter nitrogen floating above it ? Simply because gases, unlike the other forms of matter, have the property of '* diffusing " through each other, and existing together in the same space. The presence of one gas does not prevent the entrance of another into the space which it occupies, and if two open jars, containing different gases, are placed together, mouth to mouth, each gas will expand until it fills the whole volume of both receivers. Moreover, the greater the difference between the densities of the gases, and the greater consequent disposition to separate, the stronger is their tendency to mix together. This process is known as " diffusion," and plays a very important part in the plan of creation. Were no such law in operation the two gases composing air would have separated partially, and the atmosphere have become unfitted for many of its important functions. Take, for example, the function of transmitting sound. As the air is now constituted, there is a constancy of pitch, however far sound travels. Any tone once generated remains the same tone until it dies away. Its degree of loudness alters in proportion to the distance of the listener, but the pitch is constant. Were it not, however, for this law of diffusion, — were the atmosphere not perfectly homogeneous, and the gases of which it consists even partially separated, — there would have been a very different result. The constancy of pitch could no longer have been depended upon. The sound as it travelled would vary its pitch with the ever-varying medium through which it passed, and would arrive at the ear with a tone entirely different from that with which it started. Nor would it require any great difference in the medium to produce a sensible result and to confuse all those delicate differences of pitch on which the whole art of music depends. Whenever, therefore, you may be next enjoying the grand Pastoral Symphony of Beethoven or the Requiem of Mozart, recall the careful adjustment of forces by which alone these magnificent creations of genius were rendered possible, and you cannot fail to recognize in this simple law of nature the same hand that first strung the lyre and made the soul of man responsive to its seven notes. PASSIVE AND ACTIVE CONDITION. JJ notice, in the next place, that it is entirely destitute either of odor or of taste. This fact is a matter of common experience ; for as oxygen exists in a free state in the atmosphere, it would there manifest these properties did they exist : and reflect how essential these negative qualities are to our comfort and well-being. Moreover, in its ordinary condition, oxygen seems entirely devoid of any active properties. It does not affect the most delicatg and evanescent vegetable dyes, which the weakest chemical agents will either alter or destroy. And consider the oxygen as it exists in the air. How bland and seemingly inactive it is there ? Reflect that it bathes the most delicate animal organisms, that it pervades the minutest air-passages of the lungs, — remember that it is in contact with all matter, — and every substance will seem to bear evidence to the fact that oxygen in the state of gas possesses no active properties, and is incapable of manifesting any strong chemical force. And yet, if you infer that oxygen always appears in the passive condition, and is under all circumstances incapable of violent action, you will be entirely deceived ; for so far from being one of the weakest, it is the strongest of the chemical elements, and beneath this apparent mildness there is concealed an energy so violent, that, when once thoroughly aroused, nothing can withstand it. A single spark of fire will change the whole character of this element, and what was before inert and passive becomes in an instant violent and irrepressible. The gentle breeze which was waving the corn and fanning the brows- And here I must correct an erroneous, although very common impression, that there is something substantial in fire. This is one of those ideas, originating in an illusion of the senses, which we have inherited from a more ignorant age, and which our modern science cannot wholly dispel from the popular mind. Fire was formerly regarded as one of the elementary forms of matter, and all burning was supposed to consist in the escape of this principle of fire, previously pent up in the combustible substance. In support of this doctrine the old philosophers confidently pointed at flame as the visible manifestation of the escaping fire-element ; and, childish as this doctrine may seem, it was the prevalent belief of the world for at least two thousand years. The last phase which this doctrine assumed was the phlogiston theory of the last century. In the hands of Bergmann and Stahl, the vague ideas of the time received a more material form, and were embodied in a philosophical system. They termed the principle of fire phlogiston, and burning, or the escape of fire, dephlogistication, and their ingenious system did not a little to retard the progress of truth. The philosophers of that age either took no account of the increase of weight which results from burning, or attempted to explain the few instances in which the fact was forced upon their attention by the fanciful notion of Aristotle — that the essence of fire was specifically light. Hence, they reasoned, THEORY OF PHLOGISTON. 79 phlogiston buoys up all bodies into which it enters, and after its escape in the process of burning, the burnt material must weigh more than before. It was not until 1783 that the true theory of combustion was discovered, and from this discovery modern chemistry dates. The fortunate discoverer was Lavoisier. He proved, by simply weighing the prodlucts of combustion, that burning, instead of being a loss of phlogiston, is a union of the burning substance with the oxygen of the air, and this theory is now one of the best established principles of science. Burning is merely chemical change, and all combustion with which we are familiar in common life is a chemical combination of the burning substance, whether it be coal, wood, oil, or gas, with the oxygen of the air. Combustion is simply a process of chemical combination, and the light and heat which are evolved in the process are only the concomitants of the chemical change. Why those mysterious influences of light and heat are radiated from the coal which is combining with oxygen in our grates, we may understand better hereafter ; but this much we already know, — the sensations of light and heat are caused by waves of an ethereal medium breaking upon the extremities of the delicate nerves of our human organism ; and such waves are set in motion during the chemical change which we call combustion. What the chemist mostly studies, however, is the change itself, and to this we will for the present confine our attention. 80 WEIGHT OF THE SMOKE. the compounds of oxygen with the elements of coal, wood, and illuminating gas, are only two in number, carbonjc dioxide ^as and aqueous vapor. These products, as is well known, are perfectly colorless and transparent aeriform substances, wholly without odor or taste, and entirely devoid of every active quality. For this reason they escape without observation from the burning wood, ascend our chimneys, and by the force of diffusion are spread throughout the atmosphere ; but if, as may readily be done by chemical means, we collect the neglected smoke and weigh it, we shall find that it weighs much more than the burnt wood, and, as more careful experiments will show, its weight is exactly equal to that of the wood added to that of the oxygen of the air consumed during the burning. Moreover, this smoke, though so long unnoticed by man, was not overlooked by the Author of nature. It is a part of his grand and beneficent design in the scheme of organic nature. No sooner do the products of that wood burning on the hearth escape into the free expanse of the outer air, than a new cycle of changes begins. The carbonic dioxide and the aqueous vapor, after roving at liberty for a time, are absorbed_by the leaves of some jwide-spreading tree, smiling in the sunshine, andln the tiny laboratory of their green cells are worked up by those wonderful agents, the sun-rays, into new wood, absorbing from the sun afresh supply of power, which is destined, perhaps, to shed warmth and light around the fireside of a future generation. FIRE, HOW SUSTAINED. 8 1 chapter we shall discuss this wonderful cycle of changes at some length. At present I wish to direct your attention to the remarkable contrast of qualities presented by the element oxygen in its active and passive conditions. How is this complete inversion of properties to be explained ? There is a cloud of mystery hanging over the subject, which the progress of knowledge has not as yet entirely dispelled ;"^ but, so far as the cause is known, I will endeavor to make it intelligible. The difference in the action of oxygen in these two conditions depends on temperature. At the ordinary temperature of the air its chemical affinities are dormant, and, although endowed with forces which are irresistible when in action, it awaits the necessary conditions to call them forth. One of the grandest works of ancient art which have come down to us is the colossal statue of the Farnese Hercules. The hero of ancient mythology is represented in an erect form, leaning on his club, and ready for action ; but for the moment every one of the well-developed muscles of his ponderous frame is fully relaxed, and the figure is a perfect ideal of repose, yet a wonderful embodiment of power. Here in this antique we have most perfectly typified the passive condition of oxygen, the hero of the chemical elements. Raise now the temperature to a red heat, and in a moment all is changed. The dormant energies of its mighty ■^During the past four years the study of thermo-chemistry has given us the first clue toward a solution of this problem ; but as yet the results do not admit of a concise and popular statement. powers are aroused, and it rashes into combination with all combustible matter, surrounded by those glorious manifestations of light and heat which every conflagration presents. In order to evoke the latent forces in the oxygen of the atmosphere, it is not necessary, however, to raise the temperature of any considerable portion either of the gas or of the combustible. There is a provision in nature by which chemical combination, once started at any portion of the combustible mass, is sustained until the whole is consumed. (All chemical combination is attended by the evolution ^ of heaty and in the combination of oxygen with most combustible substances the amount of heat thus generated is so great, that by the burning of one portion sufficient heat is evolved to raise the temperature of a second portion to the point of ignition, and thus the process is continued. Consider, for example, what takes place in the burning of a jet of gas. We start the combustion by bringing the flame of a lighted match over the orifice of the burner. By this the temperature of the gas and that of the air surrounding it are raised to a redheat, and chemical combination at once ensues. But the chemical union, as just stated, is attended with the evolution of great heat, which, before it is dissipated, raises to the point of ignition the temperature of the next portion of gas issuing from the burner. This, combining in its turn with oxygen, generates a fresh quantity of heat, and thus keeps up the combustion so long as the gas is supplied. What I have shown to be true of a gas- POINT OF IGNITION. 83 burner is equally true of all ordinary combustion, and so a single spark may be sufficient to light up a conflagration which will reduce to ashes a whole village or involve a city in ruin. Thus it appears that burning is chemical combination with oxygen, that this union is attended with the evolution of heat, and that a high temperature is the condition under which oxygen manifests its latent power. But, you may say, these facts do not explain the difference between the two states of oxygen, they merely give the conditions under which these states are manifested ; and this is true. Why it is that at one temperature oxygen is so completely passive, and at another temperature, a few hundred degrees higher, so highly active, we cannot fully explain ; but the facts are undisputed. The temperature at which oxygen assumes its active condition is called the point of ignition. Although fixed for each substance, it differs very greatly with the different kinds of combustible matter, being determined, apparently, by their relative affinities for the great fire-element. Thus phosphorus ignites at a temperature less than that of boiling water, sulphur at about 500^, wood only at a full red-heat, anthracite coal at a white-heat, while iron requires the highest heat of a blacksmith's forge. Beginning with a phosphorus match, which can be ignited by friction, and using the more combustible materials as kindlings, we can readily attain in our furnaces the highest temperature required, and thus the energies of this powerful agent are fully at the command of man. But notice at the same time 84 FIR HOW RESTRAINED. that the^ point of ignition of wood, coal, and common combustibles, has been placed sufficiently above the ordinary temperature of the air to insure the general safety of our combustible dwellings ; and when we consider how liable they are, even now, to accidents from fire, we shall appreciate the care which has been taken by our Heavenly Father to guard us against this terrible danger. But even this precaution would have been insufficient to secure safety, were it not that the active energies of oxygen, even when aroused, have been most carefully tempered by extreme dilution. It would be easy to show by experiment that the slowness of combustion depends on the fact that in the atmosphere oxygen is mixed with a great mass of an inert gas, and the proportions have been so adjusted in the scheme of creation as generally to restrain the awakened energies of the fire-element within the narrow limits which man appoints ; but when, through his misfortune or carelessness, it overrides these limits, and, from administering to man's wants, becomes the agent of his destruction, we are reminded in the awful conflagration by what a delicate tenure we hold our earthly possessions, and how small a change would be sufficient to involve all organized matter in a general conflagration. Remember now that fire is one of the most valuable servants of mankind ; that it is the source of all artificial heat and light ; that in the steam-engine it is the apparent origin of that power which animates the commerce and the industry of the civilized world ; that under its influence iron becomes plastic, and the ores give up their metallic treasures ; that it is, in fine, the agent of all the arts, — and you cannot wonder that in a ruder age the Romans should have enthroned its presiding deity on Olympus, or the Persians worshipped its supposed essence as divinity itself. Looking at it again, in the light of modern science, as merely the manifestation of the latent power of this bland and diffusive atmosphere, the truth seems almost incredible. To think that this, the strongest of the chemical elements, — which, although a permanent gas, forms more than one-half of the solid crust of the earth, and is endowed with such mighty af^nities that it is retained securely in this solid state, — could have been so shorn of its energies as not to singe the down of the gossamer, and yet so tempered that its powers may be evoked at the will of man and made subservient to his wants ! To me the double condition of oxygen is one of the most remarkable phenomena of nature. I ponder it again and again, with increasing wonder and admiration at the skill of the infinite Designer, who i has-been able to unite in the same element perfect mildness and immeasurable power. It seems as if the millennium of the Hebrew prophet were prefigured in the atmosphere. " The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid, and the calf and the young lion and the fatling together, and a little child shall lead them.'' If I have succeeded in making clear the relations of this twofold character of oxygen to man and his works, I think that you cannot fail to have been impressed with the evidence of design which the subject affords. This evidence is seen in the facts, first, that the same element is at different temperatures endowed with such opposite and apparently incompatible qualities ; secondly, that in each of its conditions the properties are so skilfully adapted to the functions which it is appointed to perform ; thirdly, that the temperature at which it assumes its active state has been so accurately adjusted to the thermal conditions of the globe ; and lastly, that its active energies have been so carefully guarded, and placed to so great a degree under the control of man. But we have not as yet one-half exhausted the subject. Here, as everywhere else in nature, the argument is cumulative; the more we study, and the more our knowledge is enlarged, the more it grows upon us ; and wherever we may leave the field, we always are conscious that there is a still richer harvest to be reaped beyond. If the crust of the globe is a fair sample of the whole mass, oxygen was the chief material employed by the Great Architect in constructing our earth. Moreover, world-building was a process of burning, like those we have been studying, and the foundations of the earth were undoubtedly laid in flames. When we attempt to break up the various materials around us into simpler parts, we soon reach a class of substances which cannot be further decomposed. Simple inspection will show that granite rock, for example, is a mixture of three minerals, called feldspar, mica, and quartz. We know, also, that feldspar consists of alumina, potash, and silica, that mica contains the same materials in different proportions, and that quartz is silica alone. Lastly, the chemists have discovered that alumina is composed of aluntiniun and oxygen^ potash of potassium and oxygen, and silica of silicon and oxygen. But here we must stop ; for when you ask us of what these last-named materials are made, we find ourselves in the condition of the old philosopher, who got on very well with his flat earth, supporting it on an elephant, and the elephant on a tortoise, until he came to seek a resting-place for the tortoise ; but then his theory failed. So is it with our science. We call all substances which have never yet been decomposed, whatever may be their nature, chemical elements, and of such some seventy are now known. Setting apart oxygen as the supporter of combustion, the great mass of the remaining elements are combustible ; that is, under certain conditions they combine rapidly with oxygen, evolving light and heat. Indeed, many of the combustible substances with which we are most familiar are elements. Charcoal is an element, phosphorus is an element, sulphur is an element, iron and all other metals are elements, and out of such combustible materials, together with oxygen, the world is made, but chiefly out of oxygen. charcoal combines with oxygen, and the result is a transparent, colorless gas, called carbonic dioxide. Many may not have heard of such a substance before, but it is always present in the atmosphere, at least in small quantities, and if we continue our process of world-making a little further, we shall find that it enters into the composition of some of the most familiar rocks and minerals. I have at the bottom of this closed glass tube a small piece of a yellowish-white metal, looking very much like a flattened shot ; and so it is, but the metal is not lead, although it resembles lead very closely. Like lead it is quite soft, and can be easily beaten into leaves thinner than writing paper ; but it is very much lighter than lead, and tarnishes so rapidly in the air that we are obliged to keep it thus protected. We call the metal calcium, and although you may never have seen the substance before, it is one of the most abundant metals in nature, yet seldom seen, because of the extreme difficulty with which it is extracted from its ores. When heated to redness, calcium burns with a brilliant white light and a scintillating flame. In burning, it combines, of course, with oxygen, and the result is lime, common quick lime, such as is used for making mortar. This is a process which in the original world-making must have played a very important part, for lime rocks form a large portion of the earth's crust. None of these rocks, however, will slake like quicklime, and we must go a step further in our world-building, and bring in the agency of water, before we can reach the actual condition of things. We have now before us two products of burning, one a solid, called lime, made by uniting calcium with oxygen, the other a gas, called carbonic dioxide, made by uniting charcoal with oxygen. Both are soluble to a certain extent in water, and these clear solutions, called lime-water and sodawater respectively, are even more familiar to you than the substances themselves. Mix now the solutions together. The water becomes at once very turbid, and there soon settles from it a white powder. The lime and carbonic dioxide have united, and this is the result. If we collect and examine the white powder we shall find that it is chalk, and from the same material, spread in thick layers over the ocean-bed, and subsequently hardened by the mutual action of heat and water, have been formed limestone, marble, and the different varieties of lime rock, which are all ores of calcium. But we may study with profit a second example of world-building. I have here a small quantity of another very abundant element, called silicon, but, like calcium, a comparative rarity, because it is with difficulty obtained pure. It resembles in many respects carbon, and has been observed in three different states, corresponding to charcoal, graphite, and diamond Like carbon, it also is combustible, combining with the oxygen of the air when heated to a high temperature, and forming a very hard white solid, called by chemists silica, which is the same thing as quartz, rock-crystal, agate, jasper, calcedony, opal, etc. All these familiar minerals are merely different conditions of this one material, and contain over one-half their weight of oxygen gas. When ground to a coarse powder by the action of running streams, they become sand, and the grains of sand, compacted together, form sandstone and similar rocks ; and you will begin to appreciate the enormous amount of silicon which must have been burnt up in the process of world-making, when you learn that at least one-half of the solid crust of the earth consists of silica in its different varieties. Setting aside the silica for a moment, let us turn to another very widely distributed element,^ called aluminum. This brilliant white metal, comparing favorably even with silver in lustre, was, until very recently, as great a rarity as calcium or silicon ; but within a few years a process has been discovered by which it can be extracted from its ore at a cost sufficiently low to render the metal available in the arts, and it has now come into quite general use for making mathematical instruments, for jewelry, and for similar purposes. It forms also, with copper, a valuable alloy, which does not readily tarnish, and resembles gold so closely that the two cannot be distinguished by their external appearance. Aluminum, like most of the metals, is combustit)le, although it does not burn readily in the air, unless the temperature is very high and the metal finely subdivided ; but it then burns very brilliantly, emitting a vivid light, and forming a compound called by chemists alumina, which is melted by theintense heat to a yellowish transparent glass, and is the same substance from which nature makes the sapphire and the ruby, Emery also, which, on account of its great hardness, is used so largely for polishing, is only a rougher form of the same material. Unite now the alumina to silica, add water, and we get clay. Burn the clay, and we have, according to the fineness of the materials, porcelain, pottery-ware, or bricks. Taking next the element magnesium, which is also a brilliant white metal, allied to zinc, you notice that it takes fire even in the flame of a candle, and burns with dazzling brilliancy. The result is magnesia, so much used as a medicine. Unite magnesia to silica, and we have, according to the proportions, hornblende or augite, two minerals which abound in many varieties of rock. Add water to the composition, and we get also serpentine or soapstone, with several other allied mineral species. I might multiply these illustrations indefinitely, but I will limit myself to only one other example. Here is a metallic element called potassium, so light and combustible that it swims and burns on water. Burning in water may seem, at first sight, very paradoxical ; but in studying chemistry we must be ready to give up old prejudices. Water is almost pure oxygen, containing in the same volume more than one hundred times as much of the fire-element as air, and all combustibles would burn in water were it not that the oxygen is imprisoned in the liquid by an immensely strong force. Potassium, however, has such intense chemical affinities that it will break through all bars and bolts in order to unite with oxygen, and it therefore burns thus brilliantly even in the midst of water.^ The final result is a white solid called potash, which dissolves in the liquid. Melt together, now, potash, lime, and silicious sand, and we have glass. Un'te silica, alumina, and potash, and we get feldspar ; combine them in different proportions, and we have mica ; varying again the proportions, we obtain garnet. Lastly, mix quartz and feldspar together with mica or hornblende, in an indiscriminate jumble, and we have the several varieties of granitic rocks. Such, then, are some of the steps in the process of world-building. I do not mean to imply that we can reproduce all these substances in our laboratories, although even this is true in almost every case. My object is only to show what must have been in general the process of nature, and to make evident the fact that oxygen has been the chief world- S, H, CI, N. 57 others. builder. But why call oxygen the world-builder more than the other elements ? This diagram answers the question, and it illustrates one of the most remarkable facts to which the study of this function of oxygen has led. Of the seventy known elements, more or less, thirteen alone make up at least y%^(j of the whole known mass of the earth. Of this, oxygen forms about ^, silicon about ^ ; then we have aluminum, magnesium, calcium, potassium (K), sodium (Na), iron (Fe), carbon (C), sulphur (S), hydrogen (H), chlorine (CI), and nitrogen (N) filling up nearly the other fourth, while the remaining elements— including all the useful metals except iron — do not constitute altogether more than j^-^. The diagram, however, only represents the relative proportions very rudely, as the subdivisions are necessarily based on very rough estimates and imperfect data. Evidently, then, so far as our knowledge extends, oxygen, silicon, and carbon, together with a few metals, have been the chief building-materials employed by the Great Architect, and oxygen has been, as it were, the universal cement by which the other elements have been joined together to form that grand and diversified whole we call our earth. One more remark in regard to this subject, and I will close this chapter. It is probable that there was a time, anterior to the earliest geological records, when the elements were in a free state; when the oxygen now solidified was a gas, and when, at the appointed time, the union of the elements began. Then our earth was a bright, burning star, radiating heat and light into space. Indeed, if we accept the nebular hypothesis of Laplace, the earth was formerly a part of the sun, was thrown off by the centrifugal force from his burning mass, and, like a spark from a forge, soon burnt out, although after this lapse of time the great central fire is burning still. But whether Laplace be right or not, this much is certain ; — the crust of the earth, so far as we can examine it, is like a burnt cinder, and 'the atmosphere of oxygen which surrounds it is merely the residuum left after the general conflagration, — left because there was nothing more to burn. Unmeasured ages have passed away since then ; the earth's crust has cooled and solidified ; the waters have been condensed and gathered into the great ocean-basins ; the dry land has been covered with verdure and peopled with all kinds of four-footed beasts, winged fowls, and creeping things ; the waters have been tenanted with countless forms of swimming creatures; and, last of all, man has come to live in this fair creation, and study the wonders of his dwelling-place. He finds on the earth's burnt crust an abundant supply of combustible material for all his wants. But if the world was once burnt up, and the elements glowed with fervent heat, how is it that these combustibles have been left unconsumed ? Modern science has been able to answer this question. It has discovered that during the long geological periods a silent agency has been slowly recovering a small amount of combustible material from the wreck of the first conflagration. The sunbeam has partly undone the work of the fire, and whatever now exists on the earth unburnt, wood, coal, or metal, we owe to that wonderful agent the solar light. How the result has been accomplished, I propose to consider in a future chapter. Besides the two extreme conditions of oxygen, . there exists still a third, in a measure intermediate between them, but still differing essentially from either, — a condition in which the element discharges functions, less brilliant it is true, but not less interesting and instructive, than those which we studied in the last chapter. The phenomena in which this condition of oxygen is chiefly active require, as a general rule, months, or even years, for their full manifestation. Moreover, they are so silent and unobtrusive, as frequently to be passed unnoticed ; but nevertheless, when we have become acquainted with their magnitude and importance, I am sure you will agree with me that they far surpass in true grandeur those dazzling displays of power which the fire-element manifests when fully aroused. This third phase of the element can be best studied in its effects, and to two of these I now ask your attention. Every one knows that, when wood or any other organized structure is exposed to the moist atmosphere, it gradually decays. It first becomes rotten, 96 DECAY. and then slowly disappears. All may not know, however, that decay consists in a slow union of the organized structure with oxygen, and that the log of wood which is left to rot in the forest undergoes precisely the same change as one which is burnt on the hearth. The sole difference is, that, while the last is burned up in a few hours, the first entirely disappears only after the lapse of many years. Wood, like all organized vegetable structures, consists mainly of three elements, carbon, hydrogen, and oxygen. When heated on the hearth, in contact with the air, it takes fire and burns ; that is, its combustible elements combine with oxygen, the carbon to form carbonic dioxide, and the hydrogen to form aqueous vapor, both of which escape by the chimney. But of these two ingredients of the wood, hydrogen is by far the most combustible ; that is, it has the greatest tendency to combine with oxygen, and therefore burns first, leaving the less combustible carbon in the form of glowing coals. If at this point we take up one of these coals and quench it in water, it will be found to be common black charcoal ; but if left on the hearth, the coal also burns, gradually smouldering away, and passing up the chimney as carbonic dioxide gas. Quite a similar succession of phenomena is presented in the forest during the process of decay. In decay, as in burning, the oxygen of the air unites with the hydrogen of the wood more rapidly than with the carbon, and in consequence the rotten wood becomes darker and darker, from the excess of black charcoal, as the change advances. Moreover, DECAY. 97 if the supply of air is insufficient, as when the wood is buried in swamps, it is finally reduced to coal, which corresponds to half-burnt wood. In the open air, however, the charcoal as well as the hydrogen is burnt, and the log of wood is resolved, as in ordinary combustion, into carbonic dioxide and water, leaving only a few handfuls of earth to mark the spot where it lay. This change requires years before it is fully consummated, and it is not therefore wonderful that its nature should not have been understood until a comparatively recent period. Thanks to modern chemistry, the subject is now less obscure. We may not be able to trace all the steps of the process, but this much we know. Decay and burning are essentially the same chemical change. The substances involved are the same, the results are the same, and we have even been able to prove that the amount of heat generated is the same, the only difference being, that, in burning, the whole amount of heat is set free in a few hours, producing phenomena of intense ignition ; while in the process of decay the same quantity, slowly evolved during perhaps a century, escapes notice. It has been observed, that, if wood be left in contact with dry oxygen, it may be kept indefinitely without undergoing change, — a fact sufficiently proved by the mummy cases of Egypt, which in that dry climate have been preserved for over three thousand years ; — also, that if wood is impregnated with certain salts, as in the process of Kyanizing or Burnetizing, decay may be arrested, even in a damp situation, for a long time. In both cases the pre- vention depends on destroying certain very unstable compounds which are present in all green wood, and which start the decay. These are termed by chemists albuminous substances, the chief of which, vegetable albumen^ is almost identical with the white of an egg. The great bulk of all vegetable structures, as was stated above, consists of only three elements, carbon, hydrogen, and oxygen ; but these albuminous substances — which, as a rule, are present only in very small quantities — contain, in addition to the three just mentioned, a fourth element, nitrogen. Partly because they contain nitrogen, and partly, unquestionably, in consequence of the complex manner in which the four elements are combined, the albuminous substances are vastly more unstable than the great mass of vegetable matter, and in the presence of moisture they soon undergo an internal change, called putrefaction, or fermentation, by which they are broken up into simpler compounds. The precise nature of the process is not understood, but nothing appears to be added to the substance, unless it be water, and the change seems to consist in the falling to pieces of a complex organic structure. At all events, oxygen gas is not essential to the process, but the oxygen of the air which happens to be in contact with the fermenting substances, in some mysterious way, undergoes a remarkable change. It becomes endowed with active properties even at the ordinary temperature, and_, with its affinities thus exalted, slowly consumes the wood, together with all other organic compounds present. Moreover, the process, once started, sustains itself. As, in burning, the union of the combustible matter with oxygen engenders sufficient heat to maintain the surrounding gas in its highly active modification, so in like manner the process of decay seems to modify continually the neighboring oxygen, arousing its energies, and thus continuing the change. when once begun. While the plant is in great measure made up of non-nitrogenized substances, the anirhal, on the other hand, consists almost entirely of albuminous compounds. The flesh, the nerves, and the bones of our bodies all contain nitrogen, and, like the vegetable albumen, are prone to decay ; and this change is constantly going on in our living members. In a most profound sense, " in the midst of life we are in death.' The materials of our bodies are being constantly renewed, and the great mass of their structure changes in less than a year."^ At every motion of your arm, and at every breath you draw, a portion of the muscles concerned is actually burnt up in the effort. During life, in some utterly mysterious manner, beyond the range of all human science, the various gases and vapors of the atmosphere, together with a small amount of a few earthy salts, are elaborated into various organized structures. They first pass into the organism of the plant, and * The rapidity of the change has not been accurately determined. Some authors state that the great mass of the body changes every month, and when we consider the large quantities of water, carbonic dioxide, and ammonia daily secreted, the statement^appears credible ; but in the absence of direct proof we have set the limit unnecessarily high in order to avoid the slightest exaggeration. thence are transferred to the body of the animal ; but no sooner are they firmly built into the animal tissues, than a destructive change begins, by which before long they are restored to the air or the soil, only to renew the same cycle of ceaseless change. Life, during its whole existence, is an untiring builder, the oxygen of the atmosphere a fell destroyer; and when at last the builders cease, then the spirit takes it heavenward flight, and leaves the frail tenement to its appointed end. Dust returns to the dust, and these mortal mists and vapors to the air. I know that there are some who entertain a vague fear that these well-established facts of chemistry conflict with one of the most cherished doctrines of the Christian faith ; but so far from this, I find that they elucidate and confirm it. I admit that they do disprove that interpretation frequently given to the doctrine of the resurrection, which assumes that these same material atoms will form parts of our celestial bodies ; but then I find that this interpretation is as much opposed to Scripture as to science. The Saviour himself, in his reply to the incredulous Sadducees, severely rebuked such a material conception of his spiritual revelation, and the great Apostle to the Gentiles, in his vision of the glorified body, distinctly declares that this body is not the body that shall be ; but that, as the grain sown in the furrow rises into the glory of the full-eared corn, " so when this corruptible shall have put on incorruption, and this mortal shall have put on immortality,' our natural body, sown in dishonor and weak- DOCTRINE OF THE RESURRECTION. lOI ness, will be raised a spiritual body, clothed in glory and in power. " And as we have borne the image of the earthy, we shall also bear the image of the heavenly/ The glorious doctrine of the resurrection here presented, modern scientific discoveries most fully confirm. They have shown that our only abiding substance is merely the passing shadow of our outward form, that these bones and muscles are dying within us every day, that our whole life is an unceasing metempsychosis, and that the final death is but one phase of the perpetual change. Thus the idea of a spiritual body becomes not only a possible conception, but, more than this, it harmonizes with the whole order of nature ; and now that we can better trace the processes of growth in the organic world, and understand more of their hidden secrets, the inspired words of Paul have acquired fresh power, and convey to us a deeper meaning than they ever gave to the early Fathers of the Church. It is no wonder that, when men were less enlightened, the doctrine should have been misinterpreted ; but now, when the truth has been illuminated by the study of nature, why longer harass the understanding and vex the spirit with these material clogs? Hear again the words of the Apostle : " This I say, brethren, that flesh and blood cannot inherit the kingdom of God ; neither doth corruption inherit in corruption." " For this corruptible must put on incorruption, and this mortal must put on immortality.'* And now, turning to the glorious truth as Christ revealed it and Paul preached it, how greatly is our faith manifested only under form. '^That each, who seems a separate whole, Should move his rounds, and, fusing all The skirts of self again, should fall Remerging in the general Soul, ' Is faith as vague as all un sweet : Eternal form shall still divide The eternal soul from all beside ; And I shall know him when we meet.'' Chemistry has shown us that it is the form alone of our mortal bodies which is permanent, and that we retain our personality under constant change; and I lastly, in organic nature, the sprouting of the seed, the breaking of the bird from the egg, the bursting of the butterfly from the chrysalis, and ten thousand other transmutations not less wonderful, which we are daily witnessing around us, all unite their analogies to elucidate and confirm the glorious and comforting doctrine of a material resurrection in form. Moreover, when we remember that our organs of vision and hearing are capable of receiving impressions either of light or sound only when the rapidity of the undulations which cause them is comprised within certain very narrow limits, and when we recall the facts stated in a previous chapter, that there are waves of light and sound of which our dull senses take no cognizance, that there is a great difference even in human perceptivity, and that some GHOSTLY OFFICE OF OXYGEN. I03 men, more gifted than others, can see colors or hear sounds which are invisible or inaudible to the great bulk of mankind, you will appreciate how possible it is that there may be a world of spiritual existence around us — inhabiting this same globe, enjoying this same nature — of which we have no perception ; that, in fact, the wonders of the New Jerusalem may be in our midst, and the song of the angelic hosts filling the air with celestial harmony, although unheard and unseen by us. Let me not be understood as implying that science has in. any sense revealed to us a spiritual world, or that it gives the slightest shadow of support to those products of imposture, credulity, and superstition, which, under the name of witchcraft, mesmerism, or spiritualism, have in every age of the world deceived so many. The only revelation man has received of a spiritual existence is recorded in the Bible; but modern science has rendered the conception of such an existence possible, and in this way has removed a source of doubt. The materialist can no longer say that the spiritual world is inconceivable ; for these discoveries show that it may be included in the very scheme of nature in which we live, and thus, although science may not remove the veil, it at least answers this cavil of materialism. Returning now to the main subject, consider for a moment the importance of this ghostly office of oxygen in the scheme of organic nature. Reflect how soon this fair world would become a great charnel-house were it not for these provisions, by which its youth is constantly renewed. Remember IC4 RESPIRATION. also that this process of decay furnishes the materials from which young life builds her fresh and blooming forms ; that, although in the midst of life we are in death, it is equally true that death is only a phase of life. Then these changes of outward nature will assume a new aspect. It will be seen that they are the beneficent provisions of infinite wisdom, in themselves full of interest and beauty, and only sad and melancholy as they are associated with bereaved affections and disappointed hopes, or with that only real death, the moral death of the soul. * O death, where is thy sting ? O grave, where is thy victory? The sting of death is sin; and the strength of sin is the law. But thanks be to God, which giveth us the victory through our Lord Jesus Christ." I might profitably occupy several hours in describing the various processes of slow combustion, for they are all rich in illustrations of skilful design ; but I must content myself with only one other example, and from the many which crowd upon me I have chosen respiration, because it is so well understood and because it is so intimately associated with our own physical existence. Respiration is a true example of combustion. The seat of the combustion is the lungs. The substance burnt is sugar. The products are carbonic dioxide gas and water. The materials of animal food may be divided into three classes : non-nitrogenized substances, such as starch and sugar ; nitrogenized substances, like lean meat and eggs ; and, lastly, fatty substances, like butter. To these must be added a small proportion of earthy salts, which, however, as they enter into the composition of almost all varieties of food, do not properly form a distinct class. All of the three classes of food are absolutely necessary to support the life of the higher animals, and especially of man, and they are all contained in those articles of diet which will of themselves alone sustain life. Milk may be regarded as the type of animal food. 100 100 It contains, in the first place, a non-nitrogenized substance, sugar; in the second place, a nitrogenized substance, casein, which separated from milk forms cheese ; and, lastly, a fatty substance, which when separated by churning forms butter. and it also contains about two per cent, of a peculiar oil. No article of food which does not contain all three of these classes of substances can alone support life for any length of time. A man would starve to death on starch alone, on meat alone, or on butter alone. The relative proportion, however, in which these three classes of substances are required by man, depends on his outward circumstances, such as the climate, his physical activity, his occupation, or his peculiar temperament, and to the right balance of his food he is guided by experience. The different classes of food serve different functions in the body. The nitrogenized and a portion of the fatty substances are used to supply the constant waste of the tissues which results from all the animal processes. They are in some unknown way vitalized in the system, and converted into new muscles, tendons, and nerves, which take the place of those that have been used up. On the other hand, the non-nitrogenized substances, such as starch, are supposed to take no part in the formation of new tissues, and to be merely the fuel by which the animal heat is maintained. Let us very briefly follow these substances through the body, and see when and how they are burnt. By far the greater part of our daily food consists of varieties of starch or sugar. These two substances are almost identical in composition, and starch may be converted into sugar with the greatest ease. Leaving out of view the large amount of water which all our food contains, we find that of wheaten bread no less than 39 per cent, consists of starch or sugar ; of potatoes fully 92 per cent, is made up of the same materials, and in general they form over four-fifths of the solid part of all our food. These substances when taken into the stomach are almost instantaneously converted by the saliva and the gastric juice into the variety of sugar known as grape-sugar, so called because it is the sweet principle of ripe grapes. The sweet principle of honey and molasses, and the incrustation which is so frequently seen on figs and raisins, are also essentially the same substance. Grapesugar, being very soluble, dissolves in the water present, and the solution is absorbed by the veins which ramify on the surface of the intestinal canal, into which the digested food passes from the stomach. The blood, now containing sugar in solution, returns through the liver to the right side of the heart, and by this organ, which consists essentially of two ingeniously contrived force-pumps, arranged side by side, it is forced through the lungs, where the sugar is brought in contact with the air. Let us next examine for a moment this remarkable structure. The lungs, as is well known, consist of two large organs, on either side of the chest, called the left and the right lung. The right lung is divided into three smaller lungs, called lobes, the left into but two.. On examining any one of these lobes it will be found to be made up of an immense number of small membranous bags, all closely packed together. These small bags, called cells, connect by means of the bronchial tubes and windpipe with the air, through the nose and mouth. They vary in size, but on an average are about y^ of an inch in diameter, and the total number of the cells in the lungs has been estimated at six hundred millions. Their walls are exceedingly -thin, and the cells may therefore be easily compressed. The whole mass of the lungs is also exceedingly elastic, and by the action of a system of muscles their volume is alternately increased and diminished in the process of respiration. The amount of air which is thus drawn into the cells, and again expelled at each inspiration, differs in different individuals. The average quantity in the ordinary tranquil respiration of an adult is about a pint ; but in a full respiration it may be as much as two and a half pints, and by an effort the lungs may be made to inhale from five to seven pints. As the average in health is about eighteen inspirations a minute, which corresponds to about eighteen pints of air inhaled and exhaled, it follows that three thousand gallons of air pass through the lungs of an adult man every day. Some estimate it as high as four thousand gallons a day for an average man in average circumstances, and as high as five thousand seven hundred gallons a day for an athletic man undergoing severe exertion. In order that you may form an idea of this quantity, I will add that four thousand gallons of air would fill a room measuring about eight and a half feet in each dimension. Let us now turn to the blood, and examine the apparatus by which it is exposed to the air in the lungs. As we have already seen, the blood charged with sugar is received into the heart, from whence it is pumped through a long tube, called the pulmonary artery, into the lungs. This artery divides again and again until it is reduced to very small capillary tubes, which ramify on the surfaces of the air-cells. The walls of these capillaries are formed of the thinnest conceivable membrane, so as to bring the blood into as close contact as possible with the air. Here oxygen gas is absorbed in large quantities, and carbonic dioxide gas evolved. The blood now holds in solution at the same time oxygen gas and suga?, and, thus charged, it returns, by a series of veins to the left side of the heart, when by the second of the two force-pumps it is again forced through the general circulation of the body. In the meantime the oxygen absorbed by the blood while in the lungs burns up the sugar. Sugar, like wood, consists of carbon, hydrogen, and oxygen.' The last two are present in the proportions to form water, so that sugar may be said to be composed of charcoal and water. Of these two substances the charcoal only is combustible. This, during the circulation of the blood, is slowly burnt up by the dissolved oxygen, and converted into carbonic dioxide, which remains in solution until it is discharged, when the blood returns again to the lungs, or else escapes through the skin. Thus it appears that respiration is a process of combustion, in which the fuel is sugar, and the smoke carbonic dioxide and aqueous vapor. I need not dwell on a fact so universally known as the presence of carbonic dioxide in the breath. All, however, may not know how large is the volume of this gas which they daily exhale. It varies with age, sex, food, health, and a variety of other circumstances. In a full-grown man the weight of carbonic dioxide evolved from the lungs varies from one to three pounds in twenty-four hours, which is equivalent to from nine to twenty-seven cubic feet. During the present lecture the amount of carbonic dioxide which has been exhaled into this room by the audience is equal to at least seven hundred and fifty cubic feef,^ and would fill a room measuring about nine feet in each direction. From the quantity of carbonic dioxide gas exhaled we can very readily calculate the amount of charcoal burnt, which in a full-grown man will vary from five to fifteen ounces in twenty-four hours. Hence, the amount of charcoal which, in the form of sugar, has been burnt up^ in the lungs of the audience during the last hour, is equal to at least fifteen pounds,^ which I have had weighed out and placed on the lecture table, in order to give you an idea of the quantity. Moreover, it has been proved that the quantity of heat evolved by a given amount of charcoal in burning is absolutely the same, whether the combustion be rapid or slow, so that the same amount of heat has been generated in our bodies during the last hour by the slow process of respiration as would have been set free by burning this basketful of charcoal. It is no wonder, then, that the temperature of the body is always so much above that of the air, and that even in the coldest climate the heat of the blood is maintained as high as ninety-six degrees. In regulating the temperature of his body, man follows instinctively the same rules of commonsense which he applies in warming his dwellings. In proportion as the climate is cold, he supplies the loss of heat by burning more fuel in his lungs, and hence the statements of arctic voyagers, who have told us that twelve pounds of tallow-candles make only an average meal for an Esquimaux, are not inconsistent with the deductions of science. Respiration, then, like decay, is a process of slow cojnbustion, in which the oxygen of the air attacks and consumes, even at the ordinary temperature, the sugar in the blood. Let us now compare with it the rapid combustion of the same substance. During this lecture every robust man present has, on an average, burnt up the equivalent of about one ounce of sugar. This combustion has taken place so quietly, and has set free the requisite amount of heat so gradually, that we have not been conscious of it. In the blood, where the burning has been going on, sugar and oxygen, as we have seen, are in close contact. In this crucible I have mixed together just one ounce of sugar and one and one-eighth ounces of solidified oxygen, solidified by the force of chemical affinity and bound up in a white salt called chlorate of potash. The oxygen and sugar are therefore here lying side by side, as in the blood, but the conditions of slow combustion which exist in the body not being present in the crucible, they will remain in contact indefinitely, until some external agency is applied. The oxygen is now in its passive condition, but a single drop of sulphuric acid will arouse its dormant energies, and you have instantly one of the most dazzling displays of combustive energy which can be produced by art. The only difference between this brilliant deflagration and the combustion which, during the last hour, has taken place in each of our bodies, is simply this : the heat which in the blood has been imperceptibly evolved during an hour, was here concentrated into a few moments, and therefore produced phenomena of intense ignition. All the other conditions, — the material burnt, the quantity of material employed, the products generated, and the amount of heat evolved, — are in both cases essentially the same. On comparing these two phenomena together, reflect for a moment on the false estimate which we are apt to make of the phenomena of nature. The splendid displays of combustion arrest our attention by their very brilliancy, while we overlook the silent yet ceaseless processes of respiration and decay, before which, in importance and magnitude, the grandest conflagrations sink into insignificance. These fire but the spasmodic efforts of nature ; those, the appointed means by which the harmony and order of creation are preserved. Those of us who have merely studied the brilliant phenomena of nature appreciate but imperfectly the grandeur of its forces, and " those of us who limit our appreciation of the powers of oxygen to the energies displayed by this element in its fully active state, form but a very inadequate idea of the aggregate results accomplished by it in the economy of the world. ""^ Contemplate the amount of oxygen employed in the function of respiration alone. Faraday has roughly estimated that the amount of oxygen required daily to supply the lungs of the human race is at least one thousand millions of pounds ; tbat required for the respiration of the lower animals is at least twice as much as this, while the always active processes of decay require certainly no less than four thousand millions of pounds more, making a total aggregate of seven thousand millions of pounds required to carry on these processes of nature alone. Compared with this, the one thousand millions of pounds which, as Faraday estimates, are sufficient to sustain all the artificial fires lighted by man, from the camp-fire of the savage to the roaring blaze of the blast-furnace or the raging flames of a grand conflagration, seem small indeed. Whole quantity, 1,178,158,000,000,000. How utterly inconceivable are these numbers, which measure the magnitude of nature's processes, — eight thousand millions of pounds of oxygen consumed in a single day ! When reduced to tons, the numbers are equally beyond our grasp, for it corresponds to no less than 3,571,428 tons. If such be the daily requisition of this gas, will not the oxygen of the atmosphere be in time exhausted ? It is not difficult to calculate approximately the whole amount of oxygen in the atmosphere. It is equal to about 1,178,158 thousand millions of tons; a supply which, at the present rate of consumption, would last about nine hundred thousand years. We need not, therefore, fear that the amount of oxygen in the atmosphere will be sensibly diminished in our day or generation ; but then this period, immense as it is, is not to be compared with the ages of geological time. The time which has elapsed since the coal we are now burning was deposited in its beds is to be counted by many millions of years, so that since the coal epoch the oxygen of the atmosphere must have been all consumed again and again. Why, then, has it not all been removed from the atmosphere? Simply because, in the beautiful balance of creation, there is always some recuperative process for every such loss. In the case before us, it is, as we have seen, the vegetation. As fast as our OZONE. 115 breath, our fires, and the process of decay around us are removing the Hfe-giving oxygen, just so fast it is restored by every green leaf which waves in the sunshine, and by every blade of grass which sprouts under our feet. What the animal removes, the plant restores. I have before stated that, in the process of decay, the oxygen of the atmosphere, which is active in producing the change, is undoubtedly in a peculiarly modified condition, a condition in which its affinities are highly exalted even at the ordinary temperature of the air; and I also stated that this active condition of the element is apparently maintained by the process of decay itself. This subject has been greatly elucidated by modern discoveries. Of all the known processes of slow combustion, the simplest and the most active is the slow combustion of phosphorus. This familiar substance, used to tip the ends of lucifer matches, if exposed to the moist air, slowly combines with oxygen, shining at the same time in the dark with a peculiar phosphorescent light, whence the name of the substance, from two Greek words, signifying light-bearer. The process is therefore entirely analogous to decay and respiration; but since phosphorus is a chemical element, the change is far simpler, and can be more readily studied, and for this reason it may serve to elucidate those more complex processes of nature. Some years since. Professor Schonbein, a distinguished Swiss chemist, discovered that, while a stick of phosphorus was slowly burning in a jar of moist •air, a portion of the oxygen present underwent a Il6 OZONE. most remarkable change. Without entering into the details of these experiments, I will simply state that, when thus modified, ordinary oxygen seems entirely transformed. The great mass of the oxygen of the air, as you will remember, is wholly devoid of odor, and without action on the most delicate organic structures or the most fleeting vegetable colors; but when thus treated it acquires a very strong and pungent odor, rapidly rusts polished metals, excites decay in organized tissues, and at once bleaches the most permanent dyes. Could there be a more complete inversion of properties ? One of the most striking characteristics of this new modification of oxygen is its peculiar odor, and hence Schonbein calls it ozone, from a Greek verb signifying io smell. It frequently happens that a great discovery supplies the wanting links between a number of obscure facts, and thus adds quite as much to our knowledge by its indirect bearings as by the positive additions it makes to the general stock. So it has been with the discovery of ozone. Every one who has used an electrical machine must have noticed the peculiar smell which follows the electrical discharge. This was formerly supposed to be the odor of the electrical fluid itself; but as soon as ozone was discovered, the odor was recognized at once as belonging to this new agent, and it was soon ascertained that electricity is one of the most eflicient means of modifying the oxygen of the air. Returning now to the fact that the slow combustion of phosphorus throws a portion of the surrounding oxygen into a peculiar condition, in which it is highly active in producing decay and other processes of oxidation, — it certainly seems probable that decay and respiration, which are also examples of slow combustion, may act on the air in the same way. Moreover, the inference that ozone is the active agent in these processes is also supported by the fact that it is always present, to a greater or less extent, in the atmosphere, although, at most, in exceedingly minute quantities. Ozone, being so highly corrosive, cannot be present in the atmosphere in perceptible quantities without producing important effects, and some persons have thought not only to refer to it the various processes of slow combustion, but also to trace a connection between the prevalence of various contagious diseases and the excess or deficiency of this agent in the air of the infected district ; but these speculations are not as yet based on sufficient evidence, and are not worthy of serious attention. Without, however, introducing any theories not yet fully established into the line of our argument, this much is clear. Oxygen gas appears in nature in three conditions, or under three manifestations : — first, entirely passive, as in the great mass of the air; secondly, partially active, in the processes of decay and respiration ; thirdly, highly active, in the phenomena of combustion. In each of these conditions its properties have been adjusted with infinite skill and delicacy, on the one hand to the thermal and electrical conditions of the globe, and on the other, to the constitution of man and of all organic nature. Here I must conclude my brief sketch of this wonderful element. If I have succeeded in impressing on your minds some of its more characteristic qualities, if, above all, you have become aware how exactly and delicately these qualities have been adjusted in the scheme of creation, and if you have seen how the smallest permanent change would disturb the result, — this is all that I could hope. It might be expected that the element with which creative power built up the greater part of the crust of our globe, leaving only a small excess to constitute its atmosphere, would furnish abundant evidence of design, and how fully is this expectation realized ! Would that I might present to you the evidence more forcibly ! But it is possible in a popular lecture only to touch at some of the more striking points, and I have felt all the time like a schoolboy at play, in spring, in some garden rich in flowers, snatching here and there a few of the more gaudy tulips, which had fully bloomed, but leaving the beautiful and delicate buds all unnoticed. But then these buds of knowledge will blossom, and, when the summer comes, will bear a still sweeter testimony of goodness and of love. The atmosphere, as you will remember, consists mainly of two permanent and elementary gases ; and having discussed the functions of its active element, oxygen, it would seem natural to consider next the offices of nitrogen, that most singularly inert gas, which constitutes no less than four-fifths of its whole mass ; but we shall understand more clearly the complicated relations of this truly wonderful substance, associated as it is with all the higher forms of corporeal vitality, after we are acquainted with two of the remarkable cycles in nature, in which the water and carbonic dioxide of the atmosphere play a conspicuous part. It is true that these two substances are very variable constituents, and make up at best only an exceedingly small fraction of the whole mass of the air ; but nevertheless, they discharge functions no less important than those of oxygen and nitrogen, and we shall find that they are equally rich in illustrations of the wisdom and power of God. I20 GENERAL DIFFUSION OF WATER. discovered in those substances which are the most abundantly distributed through nature, and which are the most intimately associated with man, and of no substance is this principle more remarkably true than it is of water. As you well know, water is the liquid of the globe, and, if we except certain transient products of volcanic action, it is the only liquid which exists naturally on its surface. Moreover, it is in constant circulation, and, like the blood in our bodies, is the medium through which nourishment is conveyed to all parts of organized nature, and its life sustained. We should naturally expect that a substance filling so important a place in the scheme of creation would furnish undoubted evidences of design, and it will be my object in the present lecture to illustrate a few of the more striking examples of adaptation which its qualities present, beginning with the aeriform condition of water as it exists in the atmosphere. The condition of the atmosphere of aqueous vapor, which surrounds the globe, differs essentially from that of the more permanent gases which are simultaneously present. Oxygen and nitrogen cannot be reduced to liquids even by the intense cold at the poles. It is very different with aqueous vapor. The slightest reduction of temperature, when the air is saturated with moisture, is sufficient to condense a portion of the vapor to water, and to shower it on the earth in drops of rain. On the other hand, when the temperature rises, the heat converts more water into vapor, and the aqueous atmosphere is replenished. Thus it is that the THE AQUEOUS CIRCULATION. 121 atmosphere of aqueous vapor on the earth is liable to very great fluctuations, from which the Creator has protected the great mass of the air by endowing oxygen and nitrogen with the power of retaining the aeriform condition under all circumstances ; and we shall find that the fluctuation in the one case is as important as the stability in the other. I stated in the last lecture that our atmosphere may be regarded as made up of three partial atmospheres, simultaneously surrounding the globe, and as was the case with the atmosphere of oxygen, we shall best understand the fluctuations of the aqueous atmosphere if we begin by eliminating, for a moment, from our thoughts the other two. In order to make the subject clear, it will be necessary for me to dwell very briefly on a few wellestablished facts in meteorology, which, although not very interesting in themselves, will unfold to us some of the beautiful provisions of nature by which the aqueous circulation of the globe is maintained. If there were no free oxygen or nitrogen gas, the earth would still be surrounded with an atmosphere of aqueous vapor, and we are able to foresee, in some small measure, what the conditions of such an atmosphere would be. Its density at the sea level would depend chiefly on the temperature, and would therefore vary very rapidly with the latitude, and would be constantly changing at the same locality with the alternations of the climate. We are able to determine approximately what the density would be at any given temperature, and a few of the results are included in the following table : .14.50 It is evident from these numbers, that a verysmall change of temperature would cause immense fluctuation in such an atmosphere. At 0° one cubic foot of the aqueous atmosphere could contain only about three-fourths of a grain of vapor, while at 80° it could contain fifteen times as much, and hence, although under the tropics the density of our assumed atmosphere would be comparatively large, there would be almost a complete vacuum at the poles. Into this vacuum the vapor would flow from the equator, and thus in either hemisphere there would result a perfect torrent of vapor rushing towards the North or South. But it is also evident that, as this current became chilled in passing through the cooler climate of the temperate zone, the vaporwould gradually condense to water, which, falling on the land or on the ocean, would return in time to the equator, ready to begin again the same succession of ceaseless changes. Although the presence of the air materially modifies, it does not essentially change, the aqueous circulation. The air retards the formation of vapor, but does not prevent it, and at any given temperature the same amount of water will evaporate into a given space, whether it be a perfect vacuum or filled with air. Thus, for example, when air at 80° is saturated with moisture, it contains, as before, exactly 10.81 grains of vapor, and the table just given applies equally well to the actual condition of the globe, covered with its dense atmosphere of oxygen and nitrogen, as to the case just assumed. There is, however, a most important difference between the two conditions, — a difference on which the adaptation of the system of aqueous circulation in the order of nature entirely rests. Were there no air on the globe, the quantity of vapor would adjust itself almost instantaneously to any variation of temperature, and the maximum amount possible w^ould always be present at any given place. An elevation of temperature would be attended by rapid evaporation, and the amount of water required to fill the space would suddenly flash into vapor ; while, on the other hand, a corresponding depression of temperature would be accompanied with an equally sudden precipitation of the excess of water which the air could no longer contain, not in genial showers or diffusive rain, but in terrific torrents, of which the deluging showers of the tropics can give us only a feeble conception ; for the drops, falling without resistance, would be as destructive in their effects as volleys of leaden shot. In the actual condition of the atmosphere, the presence of a dense medium very greatly retards these changes, and although it does not alter their essential nature, it moderates their action and mitigates the violence of their effects. An elevation of temperature is followed by an evaporation of water into the air ; but the process is comparatively slow, and it is a long time before the air is fully saturated. So, also, when the air is saturated, a depression of temperature is followed by the condensation of a portion of the vapor into rain ; but here, again, the mass of the atmosphere tempers the abruptness of the transition, and allays its violence. The vapor condenses first into a fine dust consisting of repellent particles of water, which are so minute, and, conse-^ quently, fall so slowly against the resistance of the air, that they seem to float in the atmosphere ; and when, in consequence, probably, of some electrical discharge, these particles, losing repulsive energy, unite to form drops of rain, they again are wafted down so slowly through the resisting medium, and alight so softly, that the " soft falling snow and the diffusive rain '' have become fit emblems of the beneficence of God, as they give the strongest evidences of his wisdom and skill. Moreover, the glorious clouds, which add so much to the beauty of the landscape, and typify in their virgin whiteness the purity of heaven, are only collections of water dust floating* in the upper atmosphere, and mark the * It is well known that in a mass of air charged with aqueous vapor, the tension of the vapor is added to the tension of the air, and that such a mixture is lighter than a mass of dry air of the same temperature, whose tension equals the united tension of the gas and vapor. If, now, the vapor in such a mass of air is condensed to water dust, whose particles are mutually repelled by their similar electrical charges, we may conceive that the electrical tension takes the place of the tension of the vapor, so that the resulting cloud, as a whole, may be as light as the surrounding atmosphere in which it floats. stage of transition between vapor and rain ; and, further still, it is probable, as I stated in a previous lecture, that it is these same minute liquid drops which tint the morning and evening sky with their gorgeous hues, and cover our earthly dwelling-place with its canopy of blue. Again, the presence of the air very greatly retards the aqueous circulation above described, without" altering its essential character. There is now the same great difference between the density of the atmosphere of vapor at different latitudes, as if it were the only atmosphere on the globe, and the dense vapor of the tropics tends constantly to flow towards either pole ; but as it cannot move without carrying with it the whole mass of the atmosphere, this tendency merely increases the velocity of those great aerial currents, already described in a previous lecture. Still the general fact remains the same. From the whole surface of the globe water is constantly evaporating into the aqueous atmosphere which surrounds it. The heated air from the tropics, heavily charged with moisture, is continually moving towards the colder regions, both of the North and of the South ; and as the current thus becomes chilled, the vapor is slowly condensed, and the water showered down in fertilizing rains on the land. Thus it is that those beautiful provisions which we see in the rain all depend on the presence of the air, and result from a careful adjustment of the properties of aqueous vapor to the exact density of our atmosphere. " Hath the rain a Father? '* Science, by discovering these evidenceToT^skllTul adaptation, has most conclusively answered this question, and the answer is the same now as in the days of Job. "Behold, God is great. . . . He maketh small the drops of water: they pour down rain according to the vapor thereof." But what becomes of the rain ? Would that I could answer this question satisfactorily. We all understand the general theory of the aqueous circulation, but the deepest philosophy and the keenest science are not able to fathom its details, or to comprehend in their fulness the world of wonderful adaptations which the question unfolds. We all know that the drops of rain percolate through the soil, and collect in natural reservoirs formed between the layers of rock, and that these reservoirs supply the springs. The rills from numerous adjacent springs unite to form a brook, which increases as it flows, until it finally becomes the majestic river, rolling silently on its course. Every drop of that water has been an incessant wanderer since the dawn of creation, and it will soon be merged again in the vast ocean, only to begin anew its familiar journey. If you would gain an idea of the magnitude and extent of this wonderful circulation, you must bring together, in imagination, all the rivers of the world, the Amazon and the Orinoco, the Nile and the Ganges, the Mississippi and the St. Lawrence, and, adding to these the ten thousands of lesser streams, endeavor to form a conception of the incalculable amount of water which during twenty-four hours they pour into the vast basin of the world, and then remember that during the same period at least four times as much water must have been raised in vapor, and scattered in rain over the surface of the globe. Would you form an idea of the importance of this circulation, you must not limit your appreciation to its economical value, as a great source of power, working the mills and the forges of civilized man, and building up vast marts of manufacturing industry, nor must you regard alone its commercial value, bearing as it does on its bosom to the ocean the freights of empires. These applications of power, however important in themselves, are insignificant in extent compared with those mighty agencies which the aqueous circulation is constantly exerting in nature. It has been the great agent of geological changes : here washing avv^ay continents, and there building them up ; here gullying out valleys, and there smoothing away inequalities of surface ; here dissolving out the particles of metals from the solid rocks, and there collecting them together in beds of useful ores. It has covered the earth with verdure and animal life, by conveying nourishment to the plant and food to the animal. It sustains our own bodies, for it is a portion of this very circulation which ebbs and flows in our veins, and whose pulsations beat out the moments of our lives ; and could I bring together in one picture the infinite number of beneficent ends which it has been made by Providence to subserve, I am sure that you would agree with me that there is not in nature stronger evidence of design than in the adaptations of this simple and familiar liquid. 128 ADAPTATION OF WATER. some of the qualities of water; but, at the same time, let us not forget that the strength of our argument lies not so much in the fact that each property has been skilfully adjusted to some specific end, as it does in the harmonious working of all the separate details. Had man creative power, the first would fall within the range of his intelli- I gence ; but to adapt the same substance to a thousand different ends, and to adjust each of its properties to a thousand different conditions, covering with their complex network all the known universe, implies a power nothing less than infinite, and an I intelligence nothing lower than divine. It is evident, however, that we can gain a knowledge of the general plan only by studying the details, and unfortunately it is to these details that our accurate knowledge is almost entirely confined. We can see, for example, that each property of water has been designed for some specific purpose. We can also recognize the evident fact, that all the properties work harmoniously together in the general scheme of nature; but, in the present state of knowledge, to trace the intimate relations of these properties is frequently as impossible as it is to form a clear conception of the coexistenee and harmonious action of all. Yet in these very facts lies the whole force of the argument from design, and it is only the limitations of our knowledge and faculties which weaken the impression on our minds. But were these limitations removed, all argument would become unnecessary, for then, reasoning would be exchanged for vision, and in the reful- as we are known. It is a familiar fact, that water is an essential condition of organic life ; but few persons, I suspect, are aware that this familiar liquid constitutes the greater part of all organized beings. The physical man has been described by one writer as consisting of merely a few pounds of solid matter distributed through six pailfuls of water, and it is a fact that no less than four-fifths of these bodies of ours are made up of water. Yet this is a small proportion compared with the amount which enters into the structure of most of the lower animals. Some of these, such as the medusae, — sunfishes, — are little else than organized water. Professor Agassiz obtained from one of the large sunfishes found on our coast, weighing thirty pounds, only two hundred and forty grains of solid matter ; and we may safely say that at least nine hundred and ninety-nine parts in a thousand of these singular animals consist of water. Water constitutes, to almost as great an extent, most of the vegetable products which are articles of food, as will be seen by the accompanying table. I30 A CONSTITUENT OF ORGANIZED BEINGS. chief material of which all organized structures are formed, and in studying the aqueous circulation we have already become acquainted with the beautiful provisions of nature by which this life-giving liquid is distributed over the earth, and showered down upon the meadow and forest alike. Without water organic life cannot exist, and where, from any local causes, the supply fails, there we find a barren wilderness; while, on the other hand, the genial influences of the rain will soon make even " the desert blossom as the rose." It is a remarkable fact of physical geography, that the distribution of water by the aqueous circulation is rendered more effective by the peculiar structure of the continents, and the position of the great mountain chains. *The mountain chains," writes Professor Guyot, in his excellent work Earth and Man^ " are great condensers, placed here and there along the continents to rob the winds of their treasures, and to serve as reservoirs for the rain-waters, and to distribute them afterwards as they are needed over the surrounding plains. Their wet and cloudy summits are untiringly occupied with this important work, and from their sides flow numberless torrents and rivers, carrying in all directions wealth and life." Thus the mountains, whose majestic forms affect so powerfully the human soul, and which have exerted such an influence on the history of the race, are also among the most beneficent means in the Divine Providence by which the earth has been fertilized and rendered a fit abode for man. Moreover, these mountain chains have been evidently so dis- THE DEW. 131 tributed as to give the greatest efficiency to the aqueous circulation, and to irrigate the continents most effectively with their fertilizing floods. We cannot, therefore, suppose that even these ridges on the earth's surface, which are the lasting records of ancient geological changes, were fixed by chance, for they also bear traces of His intelligence who seeth the end from the beginning, and every part of whose works is adapted to every other. " Lord, thou hast been our dwelling-place in all generations. Before the mountains were brought forth, or ever thou hadst formed the earth and the world, even from everlasting to everlasting, thou art God." But it is not the mountains alone which condense the vapor of the atmosphere ; for, under certain conditions, the level plains act in a similar way, and distil the precious drops of dew upon" field and meadow, distributing it among the plants with discriminating care for the necessities of each. The dew is simply another phase of the great aqueous circulation, and, like the rain, it is a persuasive witness of the Divine Disposer, who has adjusted its amount to the wants of the vegetable world. Every one has noticed the deposition of moisture on a pitcher of ice-cold water during a summer's day, and in this familiar fact, we have at once an example and an illustration of the simple provision by which, during even the long droughts of summer, the plants receive a partial supply of water, sufficient, at least, to sustain their life until the later rains bring the autumn fruits to maturity, and stimulate a more vigorous growth. 132 THE DEW. The explanation of the dew upon the pitcher is very simple. The layer of air in contact with its cold mass is rapidly cooled, and when it can no longer hold all the moisture it contains, the excess is deposited in drops on the surface. Exchange now the pitcher for the earth, and you have at once an explanation of the proximate cause of the dew. After sunset the earth, like the pitcher, cools down the layer of atmosphere immediately in contact with it to such a degree that the whole of the vapor can no longer retain its aeriform condition. As a necessary result, a portion is condensed and deposited upon the surface, and this is what we call dew. But it will be asked. What cools the earth so suddenly after the setting of the sun ? For this is not so evident as the cause of the coldness of the pitcher. Certainly not, and the question will lead us to a study of those relations in which the adaptations to be discovered in this natural phenomenon are chiefly to be found. The earth, as I stated in the second lecture, is moving with immense rapidity through a space whose temperature is at least 270 degrees below the zero of Fahrenheit's thermometer, and, like a heated cannon-ball hung in the middle of a cold room, it is continually losing heat by radiation. The dense atmosphere with which it is enveloped, acting, as we have seen, like a blanket, protects the earth from the intense cold of space to a certain extent ; but still the constant loss of heat is so great, that, were the sun's rays withheld for a few days, the temperature of the surface-land, even in the tropics, would fall as low as it is now at the poles during the long night of the arctic winter. In the daytime the earth receives from the sun more heat than it loses ; but when this great thermal source is temporarily withdrawn, the loss of heat continuing as rapidly as before, the surface becomes quickly cooled, and the deposition of dew follows, as just explained ; or, if the temperature falls below the freezing-point, the dew is changed to frost. You must all have noticed that the most copious deposition both of dew and frost takes place on clear nights, and that during cloudy weather this supply of moisture is entirely withheld. The reason is ob- i vious. The earth loses heat by radiation, and the j clouds, intercepting the rays, reflect them back to f the earth. A shed or any other protection spread over the ground acts in the same way, and it is well known that a covering, however slight, is sufficient to protect tender plants from the blight of the early frosts. Can it then be an accident, a mere result of chance, that the dew is deposited most abundantly where it is needed most, and that this supply of moisture fails only when the clouds promise a more copious draught of liquid nourishment from the rain ? There is still another fact presented by the dew which is equally suggestive. The heavens do not distil their liquid treasures upon all objects alike, but the dew is deposited much more abundantly on the herbage, the shrubs, and the trees, which need the refreshing moisture, than on fallow land, the sandy plain, or the beaten road ; and here again the cause has been discovered. It is evident from the general theory of the subject, that the largest amount of dew will fall on the coldest surface, and it is equally obvious that, other things being equal, those objects will cool most rapidly which have the smallest supply of heat to lose, and which radiate it with the greatest freedom. Now it has been ascertained by experiment, that the facility of radiating heat depends entirely on the nature of the surface, and the surfaces of leaves have such a remarkable power in this respect, that it would seem as if they were especially designed for the purpose. If next you consider how small a quantity of matter the leaves contain, compared with their large radiating surfaces, you will see that there are all the conditions present of rapid cooling. When, therefore, under a clear evening sky; the rays of heat are escaping from all objects into the celestial space, the green foliage soon becomes colder than the barren rocks or the inanimate clod, and receives, in consequence, a greater supply of dew. It will be remembered, as I stated in the second lecture of this course, that the points of leaves have the power of silently discharging the thunderbolts of heaven, and that, in consequence, every tree acts far more efficiently to avert the stroke of this destructive agent than the best constructed lightning-rod. Is not, now, the force of this evidence of adaptation very greatly enhanced, when we find that the surfaces of these same leaves have been endowed with an equally remarkable power of radiating heat, by which they are insured a daily supply of moisture when they need it most ? Could the adaptation of the structure of the leaf to these two entirely dis- tinct physical conditions of the atmosphere be the result of anything but intelligence ? Admitting, with the modern advocates of the development theory, that under the pressure of circumstances a plant may change its structure so as to adapt it to the external conditions, still I think no one will be so bold as to maintain that there can be any brute agency in vegetation endowed with such foresight as to have adapted the material and structure of each leaf, from the very first, to the physical conditions of the globe, and this, moreover, for the purpose of effecting ends so remotely connected with its own organization as the discharge of electricity or the radiation of heat. If this can result from chance, under its modern name of natural selection, then chance is but a counterfeit name of God. Gideon believed that God would save* Israel, because the dew fell on the fleece, but not on the ground, and afterwards on the ground, but not on the fleece; and shall we doubt the reality of the Divine Providence, before whom a similar miracle is repeated every evening, with such beneficent results? If it be the mark of intelligence to be able to fathom and comprehend this wonder of Nature, can it be anything below Infinite Intelligence ^^ who hath begotten the drops of dew " ? I might, with advantage, enter more into detail in regard to the laws of the distribution both of the rain and of the dew, but time and space forbid. I have been able only to open the subject ; yet if I have succeeded in impressing you with the extent of the field which these beautiful phenomena pre- 136 WATER THE GREAT PURIFIER. sent to your inquiry, it is all that I could expect. We have seen that it is through these familiar channels that liquid nourishment is conveyed to the organic world, and the reservoirs supplied which feed the great river-system of the globe. But we should form a very imperfect idea of the resources of nature were we to limit our regards of the aqueous circulation to this important use. The life-blood of our bodies, which conveys to each muscle the nourishment it requires, when it returns again through the veins, this errand well done, is no less usefully employed in carrying away the portions of the tissues which have been worn out in the processes of life ; and where from any cause this last function is not faithfully discharged, and the wasted muscles are allowed to remain in the system, disease and death are the inevitable results. So also is it with the lifeliquid of nature, which in the rain and the dew carries food to the whole organic world. When this office has been fulfilled, it returns again to the ocean, washing away those waste products of organic life, which, if they remained, would cause pestilence and death. It is true that we cannot trace all the details of this cleansing process ; but you need not the aid of science to assure you of the general facts. Let the free flowing of the rain-water be interrupted, and you well know that stagnant pools, breeding pestilence, or deadly swamps, exhaling malaria, are the immediate results. I cannot overstate the importance of this function of the aqueous circulation, or too strongly insist on the evidence of wisdom which the adaptation of the properties of water to this beneficent end implies. It is the great cleansing agent of the world. Wherever it flows, there it purifies, and its limpid streams, clear as crystal, are fit emblems of the purity of heaven. Hence the significance of this liquid in all religious systems. The ancient Egyptians worshipped the water of the Nile, and the Hindoo idolaters of the present day reverence with equal devotion the water of the Ganges. Passing to Judaism, we find the washing with water enjoined as a sacred duty by the Hebrew law ; and lastly, in the Christian dispensation the pure liquid has become the medium of its most sacred rite, and the outward washing of baptism typifies that inward " washing of regeneration," by which alone man is saved. Glancing now, for a single moment, at the aesthetic aspects of the subject, consider what sources of pleasure the varied phases of the aqueous circulation furnish, and what an influence on the soul of man they are calculated to exert. The bubbling spring, the purling rill, the murmuring brook, the sparkling cascade, the roaring torrent, the majestically flowing river, are familiar images of poetry, and the occasions of mental emotions which all have experienced and none can fully describe ; while the mighty cataract and the ocean-storm are among the sublimest aspects of nature, and inspire the beholder with reverence and awe. When, now, you reflect that the chords of the human soul have been so strung as to vibrate in sympathy with these emotions of the material creation, and that thus the aqueous circulation has been made a means of in- 138 FERTILITY OF RESOURCES. structing and elevating the human race, can you refuse to accept the evidence of wisdom and goodness which a system, so far-seeing in its design, and so beneficent in its results, affords ? The mechanism of nature differs, as we have seen, from the creations of human ingenuity, in the fertility of its resources. Man combines numerous means in order to produce a single end; but in nature the most varied and apparently incompatible results flow from a single design. In God's works the means are employed, not as we use them in the poverty of our resources, but from the exuberance of riches. To use the language of another : ^^ All the means are ends, and all the ends are means ; ' and the grand result is an harmonious system, in which every part is a whole, and where the whole that is known is felt to be only a very insignificant part. Such is the character of the aqueous circulation, which we are now studying, and assuredly the numerous results we have already seen flowing from this simple mechanism are suf^cient to mark the system as Divine ; but we have not as yet exhausted its resources. Indeed, we have been all the time looking at only one side of the design, and there is a whole set of adaptations yet unnoticed, which are no less important in the scheme of organic nature than the one we have chiefly considered. And when we have become acquainted with these, we shall find still other phases of this boundless plan presented to our view, and not until man ceases to learn by study, or the waters cease to roll, will the subject be exhausted. LATENT HEAT OF STEAM. 1 39 We have thus far only considered the agency of the aqueous circulation in distributing over the earth the chief constituent of all organic matter, together with some of the secondary ends which the riversystem of the globe subserves. But there is another condition of organic life no less essential than moisture. The animal kingdom is absolutely dependent on the vegetable, and plants cannot grow except within a limited range of temperature. Therefore, unless during at least a portion of the year the amount of heat supplied is sufficient to maintain the temperature of the climate within the required limits, organic life cannot exist in that region. Now this familiar substance, water, has been endowed with most remarkable and unusual properties, by which the aqueous circulation has been made a great means of distributing heat, and thus of sustaining organic life in vast tracts of country where otherwise it could not exist ; and it is to this class of its adaptations that I wish next to call your attention. One of the prominent inventions of modern times is the method of heating large buildings by steam. You must all have seen the apparatus. There is first the boiler, where the steam is generated by the combustion of fuel ; then pipes, by which it is distributed to the different rooms ; next the iron radiators, in which the steam is condensed to water, and during this change gives out heat, which is radiated from the corrugated surface of the iron; and, lastly, the return pipes, through which the condensed water flows back to the boiler, ready to start again on the same journey. Every one is familiar with these I40 HEATING BY STEAM. external aspects of the apparatus ; but all may not know that the efficiency of the method depends entirely upon a remarkable quality of water, a quality which is not possessed to the same degree by any other known liquid. Were you to test with a thermometer the temperature of the w^ater in the boiler and that of the steam rising from it, you would be surprised to find, — if you were not forewarned of the fact, — that they were precisely at the same point ; and yet in order to change one pound of boiling water into one pound of steam it is necessary to burn up sufficient coal to raise the temperature of ten pounds of ice-cold water to the boiling-point. The coal which is burning under the boiler does not raise the temperature of the water. Press the fire ever so hard, you cannot increase the temperature either of the water or of the steam by a single degree. The effect of increasing the fire will be only to generate steam more rapidly, for the whole of the immense amount of heat set free by the burning fuel is absorbed by the boiling water in changing into steam. But this heat is not lost. It reaaains latent^ in the steam, is carried by it into the different rooms, and there, when the steam changes back again into water, it is all given up, without the slightest diminution, diffusing its genial warmth through the house. The steam, therefore, is merely the vehicle by which heat is carried over the building. The heat comes from the burning fuel in the cellar, and originally it came from the sun ; for the coals burning under the boiler are merely fagots, as it were, of condensed sunbeams, gathered by the plants of some ancient geological epoch, subsequently fossilized and preserved in the earth for our use. The steam merely acts the part of a common carrier; but what I wish you to notice is the fact that steam is peculiarly fitted for the work, because it has been made capable of holding so large a quantity of heat. Your attention, perhaps, has been called to the efficiency and economy of this method of heating; you have admired its neatness and absolute safety from fire, and have been delighted with the softness of the temperature which it diffuses through the rooms; or, if you have examined more closely the details of the apparatus, you must have been struck with the ingenuity of the adjustments by which it is selfregulated. Yet this is no new invention. A similar apparatus, on a vastly grander scale, working with far greater economy and efficiency, and provided with adjustments of wonderful delicacy, which perfectly regulate its action, and which never fail and never wear out, has been at work ever since the dawn of the creation, and is at this moment softening the inclemency of our northern winter. The general aqueous circulation is a great steamheating apparatus, with its boiler in the tropics and its condensers all over the globe. The sun's rays make the steam, and wherever dew, rain, or snow falls, there the heat, which came originally from the sun, and which has been brought from the tropics concealed in the folds of the vapor, is set free to warm the less favored regions of the earth. This apparatus of nature, although so much simpler, and 142 THE EARTH S STEAM HEATER. working without pipes, iron boiler, or radiators, is exactly the same in principle as the steam-heater, which may be seen at work in almost every large factor}-'. It is true that the atmospheric vapor is a much better vehicle of heat than ordinary steam, and it is also true that this thermal application is but one of the hundred uses of the aqueous circulation ; but still the general method is the same, and both systems owe their efficiency to the unique property with which water has been endowed. It is true that other liquids in changing into vapor absorb heat, but the heat stored up in these vapors is vastly less than that in steam, and it must be noticed that, of all created forms of matter, this familiar liquid, which fills the ocean, which distils upon us in the rain, and which flows in the rivers, is the only substance which has been thus especially endowed. Is this an accidental concurrence of circumstances? or is it, on the contrary, the work of Infinite Wisdom? We regard, and with reason, the beautiful invention of man, by which our dwellings are warmed, as an evidence of .intelligence ; and can we refuse to recognize the existence of that higher Intelligence, which not only adjusted the more perfect system of nature, but also created the properties of water, on which the efficiency of both depends ? Having considered that peculiar quality of vapor through which the aqueous circulation becomes an important means of distributing the sun's heat over the surface of the globe, we might next discuss more at length the extent of its influence, and examine in detail the ingenious system of checks and balances CAPACITY OF WATER FOR HEAT. I43 by which the action of this great heating apparatus is regulated, and its constant working secured ; but here, as before, having glanced at the main points, I must leave it to your study to fill the unavoidable blanks, and pass on to consider another special property of water by which a similar result is secured. The amount of heat required to raise the temperature of a pound of water, or of any other substance, one degree, is capable of exact measurement, and the quantity has been determined experimentally for almost every known substance. These experiments have led to a remarkable result, to which I alluded in a former lecture. It appears that, when water is heated through a given number of degrees, it absorbs more than twice as much heat as any other substance (except one or two very closely related bodies), and more than ten times as much as iron and most of the metals. It is not probable that many of my audience have verified this striking result, but you all know how long it takes to boil a tea-kettle, even over a brisk fire, and have, therefore, some conception of the amount of heat which cold water is capable of absorbing. This familiar experience shows that water has a very great capacity of holding heat, and accurate experiment has proved, as just stated, that, with the exception just noticed, water contains, at the same temperature, more than twice as much heat as any other solid or liquid known. 144 THE OCEANS ARE RESERVOIRS OF HEAT. lakes, and the oceans great reservoirs of heat. It not only requires a vast amount of heat to warm one of these large bodies of water, but when once warmed they cool very slowly. Hence the marked difference between the oceanic and the continental climate in the same latitude. During the summer the ocean eagerly absorbs the heat of the sun's rays, which are showered upon it in such profusion ; but water has so great a capacity for heat, that the ocean, nevertheless, does not grow very warm, and, moreover, a large amount of the heat it receives is carried away by the vapor which is constantly rising from its surface. In winter, on the other hand, the water gives up its heat to warm the colder air ; but it contains such an inexhaustible supply, that the loss does not materially lower its temperature. There results, in consequence, a great uniformity of temperature, in which the air, by its perpetual contact with the surface of the water, necessarily shares, and this uniformity extends, in a greater or less degree, to the -climate of all islands and seaboard districts. It is quite different with the surface of continents. There the soil becomes rapidly heated under the vertical rays of a summer's sun, and, as its particles are immovable, the surface-layer soon rises to a high temperature ; while, on the other hand, in winter it is cooled by radiation with equal rapidity ; and this is the cause of those extremes of heat and cold which characterize all countries of the temperate zone removed from the influence of the ocean. During the day, OCEANIC AND CONTINENTAL CLIMATES. I45 under the same circumstances, the land is warmer than the sea, and colder during the night, or, taking the different seasons, the land is warmer than the sea in summer and colder in winter. These general principles have been verified by the extensive series of meteorological observations which, during the last twenty-five years, have been made all over the civilized world. You will find an excellent abstract of the results in Professor Guyot's work on Earth and Man, before referred to. I have time only to cite a few familiar facts in illustration of my subject, which I will give nearly in his words. * On the coast of Cornwall shrubs as delicate as the laurel or the camellia are green through the whole year, while under the same latitude in the interior of the continents, the most hardy trees can alone brave the rigor of the winter. But on the other hand, the mild climate of England cannot ripen the grape, although almost under the same parallel grow the delicious wines of the Rhine. At Astrachan, on the northern shore of the Caspian, as Humboldt tells us, the grapes and fruits of every kind are as beautiful and luscious as in the Canaries and in Italy; the wines have all the fire of those of the south of Europe, although in the same latitude, at the mouth of the Loire, on the Atlantic sea-coast, the vines hardly flourish at all. But while in the south of France the winter is a perpetual spring, the summers of the Caspian are succeeded by a winter of almost polar severity." mate of the globe. This influence of water is very greatly increased by the oceanic currents, which, like the winds, are set in motion by the heat of the sun, and are constantly carrying the warm waters of the tropics toward the poles. One of the most remarkable of these currents is the Gulf-Stream, which flows near our coast, and which diffuses the warm waters of the Caribbean Sea and the Gulf of Mexico over the Northern Atlantic, depositing on the shores of Scotland and Norway the plants and seeds of the tropics. It is solely the heat which these waters bring with them from the equator that has made the island of Great Britain so great a centre of commerce and civilization ; for it must be remembered that the latitude of England is the same as that of Labrador, and, were it not for the influence of this ocean current, her soil would be equally desolate and barren. If the configuration of our Western Continent were only so slightly changed as to give a passage to the equatorial current through the present Isthmus of Panama — a change insignificant in comparison with those which have heretofore taken place— "the mountains of Wales and Scotland would become again the abode of glaciers, and civilization would disappear before the invasion of arctic cold." ^ So also it is to the enormous mass of heated water which the Gulf-Stream pours into the seas surround- POINT OF MAXIMUM DENSITY. I47 inc^ northern Europe that Sweden and Norway owe their temperate climate, while at the corresponding latitudes on our own continent the land is shrouded in eternal ice and snow. But all these provisions for distributing heat over the earth's surface would have been insufficient to maintain organic life in our northern climate, were it not for still another remarkable property with which water has been endowed, — a property even more entirely unique than either of those we have studied, and one which seems to be an exception to the general laws of nature. The familiar cycles of organic life, both in animals and plants, afe intimately associated with the succession of the seasons, and this, in its turn, depends on the inclination of the earth's axis to the plane of the ecliptic, and on the great primary laws by which this axis is constantly maintained in a position parallel to itself during the revolution of the planet around the sun. To these fundamental conditions in the formation of the solar system the whole constitution of organic life on the earth has been adjusted ; and Dr. Whewell, in his excellent Bridgewater Treatise, has discussed at length the evidences of design which this circumstance affords. It would be foreign to my plan, to consider these evidences here; but, assuming the succession of the seasons as a part of the order of creation, and as a means of adapting a larger portion of the earth's surface to the habitation of organized beings, it is evident that the higher forms of organic life could be sustained in these northern regions only by fur- nishing to the plants and animals an adequate protection against the intense cold of winter, and thus preserving the growth of one summer until the returning sun awakened new life in the succeeding spring. The required protection has been provided by making a most marked exception to the general laws of expansion in the case of water. It is the general law of nature that all substances are expanded by heat and contracted by cold, and water forms no exception to the general rule, except within certain very narrow limits of temperature, shortly to be noticed. Indeed, were it not for the expansion, we could not readily either heat or cool a large mass of liquid matter. All liquids are very poor conductors of heat, and can be heated only by bringing their particles successively in contact with the source of heat. When you set a tea-kettle over a fire, the first effect of the heat is to expand the particles of water resting on the bottom of the kettle, which, being thus rendered specifically lighter, rise, and are succeeded by colder particles, which are heated and rise in their turn ; and thus the circulation is established by which all the particles are successively brought in contact with the heated bottom of the kettle, and in the course of time the temperature of the whole mass is raised to the boiling-point. The case is similar when you add ice to a pitcher of water in order to cool it. The water at the top of the pitcher, in contact with the ice is, of course, cooled, and, being thus rendered specifically heavier than the water below, sinks and gives place to the warmer water, which is cooled and sinks in its turn, and thus, as before, a circulation is established, which continues until the temperature of the whole water is reduced to 40"^. But at this point the circulation is entirely arrested ; for, in consequence of its singular constitution, water at 39° is lighter than water at 40°, and consequently remains at the top. And so it is as the temperature sinks toward the freezing-point. The colder the water, the lighter it becomes, and the more persistently it remains at the surface. Hence, although the upper layers of water may be readily cooled to the freezing-point, yet, in consequence of its poor conducting power, the great body of the liquid below will remain at the temperature of 40''. The coTd^^atmosphere of winter acts upon the ponds and lakes exactly as the ice on the water in the pitcher. They also are cooled from the surface, and a circulation is established by the constant sinking of the chilled water until the temperature falls to 40°. But at this point, still eight degrees above the freezing-point, the circulation stops. The surface-water, as it cools below this temperature, remains at the top, and in the end freezes ; but then comes into play still another provision in the properties of water. Most substances are heavier in their solid than in their liquid state ; but ice, on the contrary, is lighter than water, and therefore floats on its surface. Moreover, as ice is a very poor conductor of heat, it serves as a protection to the lake, so that at the depth of a few feet, at most, the temperature of the water during winter is never under weeks below zero. If water resembled other liquids, and continued to contract with cold to its freezing-point, — if this exception had not been made, the whole order of nature would have been reversed. The circulation just described would continue until the whole mass of water in the lake had fallen to the freezing-point. The ice would then first form at the bottom, and the congelation would continue until the whole lake had been changed into one mass of solid ice. Upon such a mass the hottest summer would produce but little effect ; for the poor conducting power would then prevent its melting, and instead of ponds and lakes we should have large masses of ice, which during the summer would melt on the surface to the depth of only a few feet. It is unnecessary to state that this condition of things would be utterly inconsistent with the existence of aquatic plants or animals, and it would be almost as fatal to organic life everywhere ; for not only are all parts of the creation so indissolubly bound together that, if one member suffers, all the other members suffer with it, but moreover, the soil itself would, to a certain extent, share in the fate of the ponds. The soil is always more or less saturated with water, and, under existing conditions in our temperate zone, the frost does not penetrate to a sufHcient depth to kill the roots and seeds of plants which are buried under it. But were water constituted like other liquids, the soil would remain frozen to the depth of many feet, and the only effect of the summer's heat would be to THE FROST BLANKET. 15I melt a few inches at the surface. It would be, perhaps, possible to cultivate some hardy annuals in such a climate, but this would be all. Trees and shrubs could not brave the severity of the winter. Thus, then, it appears that the very existence of life in these temperate regions of the earth depends on an apparent exception to a general law of nature, so slight and limited in its extent that it can only be detected by the most refined scientific observation. Moreover, this exceptional property is united in water with another quality, which greatly aids in preserving vegetable life during the winter months. We shudder at the thought of snow, but nevertheless it affords a most effectual protection to the soil, forming as warm a covering as would the softest wool. Water in all its conditions has been made a very bad conductor of heat, and snow is ranked with wool among the poorest of conductors. Heat, therefore, cannot readily escape from a snow-covered so]], and thus its temperature is prevented from falling materially below the freezing-point, however great the severity of the season. Notice now, that, when winter sets in and the cold increases to such a degree as to endanger the tender plants. Nature promptly spreads her great frost -blanket over forest, prairie, meadow, and garden alike, so that all may slumber on in safety until the sun returns and melts away the downy covering, when the buds break forth again and the trees put on a new mantle of living green. 152 HEAT OF FUSION. for nature has provided in the constitution of water a most effectual means of tempering the transition of the seasons, and protecting vegetation against the early frosts of autumn or the first deceptive glow of returning spring. In order to freeze a liquid it is necessary to remove from it a certain quantity of heat called the heat of fusion, and the more of this heat a liquid contains, with the more difficulty, of course, it freezes, and when once frozen the less readily the solid melts. Now water contains a larger amount of heat of fusion than any other liquid yet examined, and in this respect, therefore, it is also peculiarly constituted. And mark how this property tends to produce the result just noticed. As the weather becomes cooler in autumn, our ponds and lakes gradually give up the stores of heat which they contain, until the temperature of the whole mass of water is reduced to 40° ; then the surfacewater cools still further to the freezing-point ; but before it can beconle any colder than this the water must freeze, and in freezing it will set free four times as much heat as it has already given out in cooling from the temperature of summer (63°) to the freezing-point. It is evident, therefore, that freezing must be a slow process. Moreover, it is also a warming process, and although the temperature of surrounding objects can never be thus raised above the freezing-point, nevertheless the immense amount of heat evolved greatly tends to retard the approach of severe cold, and prepares the way for the inclemency of winter. So also, when spring comes, vegetation is not awakened by her first touch to be exposed to the blights of the early frosts, and before the snow covering can be melted off the danger is mostly passed. Again, when we consider what devastating floods would sweep the earth were the icy bonds of winter suddenly dissolved, we shall discover still further evidence of the wisdom of that Being who has so adjusted the properties of water that both frost and freshet are the exception, not the rule. I have said that water presents the only wellestablished exception to the laws of expansion by heat, and some writers on natural theology have dwelt on this point as one of great importance to their argument. But I cannot think they are wise ; for, to say the least, they rest their argument on our ignorance, and not on our knowledge. It is true that in the present state of science the anomalous expansion of water near the freezing-point seems to be an exception'^ to the general laws of nature; but hereafter this very anomaly may appear to be the natural result of a more general law not yet discovered, or, like the perturbations in the orbits of the planets, may prove to be the strongest confirmation of the very law it now seems to invalidate. Moreover, I do not share in that indefinite dread of natural laws which troubles so many religious minds. To me the laws of nature afford the strongest evidences of the existence of a God, and in their uniformity I see merely the constant action of an omnipresent Creator, who acts with perfect regularity 154 NATURE OF THE EVIDENCE. because he acts consistently and with infinite wisdom. I beHeve that all parts of nature are correlated by laws, and that the wider our knowledge becomes, the more universal these laws will appear. I do not, therefore, regard the constitution of water as something apart from law, and as the evidence of a power coming down, as it were, upon law to make an exception to it. This is making altogether too much of law. God is not bound by law. He acts wisely, beneficentry, and with a definite plan, and the most we can claim for natural laws is, that they are our imperfect human expressions of this Divine plan. Moreover, that is a far nobler view of God's wisdom which supposes Him to be able to harmonize special adaptations with general laws. What I find so remarkable in the constitution of water is, not that it is an exception to the general laws of nature, but that, while filling its place in the general plan, it has been endowed with such extreme properties, and that in each case the peculiar property has special adaptations at once so complex and so important. Not only has water this exceptional property of expanding when other liquids contract, but, moreover, of all known substances it has the greatest capacity for heat ; so also, when changing into vapor, it absorbs more heat than any other liquid ; again, it is far lighter in the solid than in the liquid state ; and lastly, it contains the largest amount of heat of fusion as yet observed in any substance. All this may be in harmony with general laws. I have no doubt that it is ; but the existence of the law does not in the least impair the significance of the fact, that in each of these respects water has been pecuHarly constituted. This one liquid of the globe, which covers more than three-fourths of its surface, which circulates through all its channels, which percolates through all its pores, which constitutes three-fourths of all organized beings, has been endowed with these four pre-eminent qualities, on each of which the whole order of terrestrial nature may be said to depend. I cannot conceive of stronger evidence of design than this ; and if these facts do not prove the existence of an intelligent Creator, then all nature is a deception and our own faculties a lie. Yet, my friends, this is only a small part of the evidence of design which science has discovered in this familiar liquid. I might occupy several lectures with this subject alone, but I have time only to glance at two more striking facts. Water is the most universal solvent known, and there are but few substances which are not, to a greater or less degree, dissolved by it. Those which we call insoluble generally differ from the rest only in degree. Thus, all lime rocks dissolve to a limited extent in spring water, and the same is also true of almost all mineral substances. The magnificent crystals which we frequently find in the rocks are formed in almost every case by a deposition of the mineral substance from a state of solution in water. The feeble solvent power of the water for these substances is made up by the large volume of the solution, and the length of time occupied in the process of crystallization. Many of the large crystals which may be seen in cabinets of minerals have 156 SOLVENT POWER. been unquestionably thousands of years in formation. And not only does the solvent power of water stud the cavities of the rocks with gems, but it is also constantly producing most important changes in the rocky structures of the globe itself, here cementing together the loose sands, and there converting the soft clays into firm and solid rock. Again, the solvent power of water extends to aeriform as well as to the solid substances, so that the gases composing the air pervade the lakes and the oceans as well as the atmosphere. Indeed, it is on the gases dissolved in the water that all the aquatic plants and animals live, and the members of the various finny tribes breathe the free oxygen dissolv^ed in the water, as we breathe the oxygen of the air. Again, the process of respiration is essentially the same with these lower animals that it is with us, and the structure of their organs has been adjusted to the amount of this life-sustaining element which water is capable of dissolving. Moreover, the power which water possesses of dissolving oxygen is much greater than its power of dissolving nitrogen, and hence the air dissolved in the ocean is proportionally much richer in oxygen than our atmosphere. This is undoubtedly another quality with which water has been endowed in order to render the oceans, the lakes, and the rivers a fit habitation for that world of organic life which modern zoology has revealed. That we are unable to trace all its relations, is evidently owing to the imperfection of our knowledge. But here a new field of study opens before us, which, when fully explored, design as the atmosphere itself. It is not, however, merely as a solvent, that water is an important agent in the great laboratory of the world. I have already stated to what extent all animal and vegetable substances are composed of water, and that some, such as the jelly-fishes among animals, and the gourd family among plants, may be said to be living forms of water. But we should entertain a very erroneous conception of the condition of the water in these animal and vegetable structures, were we to regard it as so much dead material, building up the form like the bricks in an edifice. This water is in constant circulation, conveying nourishment to all the parts, and at the same time removing from the system those tissues which have fulfilled their functions and become effete. It is being constantly decomposed, and as rapidly again reformed, assuming the most protean conditions, and administering to the functions of the animal economy in a thousand ways. As a constituent of inorganic matter, water is no less important than it is in organized being. A substance so bland as water, and apparently so entirely inactive, which fills the most delicate vegetable cells, and penetrates the finest capillaries of the body, — whose minuteness and delicacy no art can approach, nor imagination scarcely conceive, — yet without affecting either in the slightest degree, we should suppose would be endowed with no affinities, and capable of exerting no chemical force. Yet what is the fact? In attempting to classify IS8 COMPOSITION OF WATER. chemical compounds, I have studied with care the chemical history of water, and its relations to other substances, and it is still to me a perfect enigma in nature. For, so far from being that inert material which its bland exterior would seem to indicate, it is among the most important of chemical agents, forming some of the most stable compounds, and surprising the chemist by the strength of its affinities. Not only is water a common constituent of most crystalline salts, and an essential ingredient of many of the powerful acids which are used both in the arts and in the chemist's laboratory, but it makes, also, a not unimportant part of the rocky crust of the globe. Besides forming the immense deposits of ice which perpetually surround either pole, and the glaciers which creep down the high mountain slopes, we find that water enters as an essential ingredient into the composition of talcose and chlorite slate, gypsum, serpentine, soapstone, and other rocks. Moreover, water is the medium in which most chemical processes take place, and throughout all geological history it has been producing the most fundamental changes in the composition of the earth's crust, the extent of which geologists are only of late beginning to appreciate. It is now supposed that granite and similar rocks, which were formerly regarded as products of igneous fusion, have been really formed from loose beds of mud and clay, through the transforming power of this wonderful and powerful agent. LATENT POWER. 1 59 consists of two permanent gases, condensed by the force of chemical affinity to the liquid condition. With one of these, oxygen, you are already familiar. The other is a light, combustible gas, called hydrogen, fourteen and a half times lighter than air, and by far the lightest form of matter known. One cubic foot of water yields more than eighteen hundred cubic feet of a mixture of these two gases, and so persistently do they retain their aeriform condition, that not even a pressure of twenty tons on the square inch is sufficient to reduce them to liquids. Yet, immense as this pressure seems, requiring all the mechanical skill of man to apply it, that force must be still greater which is constantly acting in every drop of water to hold these highly elastic gases in the liquid state. It is difficult to estimate the magnitude of such power, as our only standard of measurement is the quantity of some other force, equally immeasurable, which is required to balance the first. Water is easily decomposed by electricity, and the amount of this agent required to force apart its constituents may perhaps give you some imperfect conception of the magnitude of that power by which they are so securely imprisoned. The statement may seem incredible, but yet it has been proved by Professor Faraday, that it requires more electricity to decompose a drop of water than to charge a thunder-cloud. every drop of water there is a constant striving of the elements to escape; they are exerting a force to break the bonds that unite them, which can be l6o SUMMING UP measured only by the power of concentrated thunder-bolts, and yet this immense force is kept in check by a force of equal power, and so exactly balanced that not the slightest disturbance can occur. When now I endeavor to estimate the value of this chemical force by our human standards, and find that in comparison with it all the mechanical energy which man can exert, even when aided by the appliances of modern art, is utterly insignificant ; and when I reflect that in every particle of water the force is still acting, so that every rain-drop which falls is a silent monitor of human weakness, I am overwhelmed by that mystery in nature, which, here as elsewhere, ever points upward to the Infinite, and thus silently teaches that the mighty influence which binds the atoms of the rain-drop is merely the manifestation of His ceaseless power who holdeth '' the waters in the hollow of His hand." f It is a very common mistake to suppose that /the grand in nature is to be seen only in its i great water-falls and its lofty mountains ; for, to the intellectual eye, there is more real grandeur, more evidence of omnipotence, in a single raindrop than in the rush of Niagara or in the magnitude of Mont Blanc. The more I study the evidence of design in this simple liquid, the more I find there is to learn, and I feel the utter inadequacy of any language to convey the full and complete idea. Review, for a moment, the examples of adaptation which have been so briefly noticed. Remember that water is the liquid of our globe, and the only liquid which exists in any abundance on its surface. The total amount of all other liquids is in comparison but as ' a drop of a bucket." Consider, next, that its specific gravity has been so adjusted that our ships float, and the oceans are made great highways for the nations ; that it is easily converted into vapor, and as easily condensed to fertilizing rain and refreshing dew, which nourish the growing plants, fill the springs, and keep the rivers — the great arteries of the globe — in circulation ; that at a comparatively low temperature it is changed into highly elastic steam, which, imprisoned by man in his iron boilers, has become the great civilizer of the world ; that it has been so exceptionally constituted that the great mass cannot be cooled below forty degrees, and again has been made such a poor conductor of heat that, when the surface is frozen, the very ice becomes a protection against the cold ; that to this same liquid there has been given a very great capacity for heat, and that thus it has been made the means of tempering materially the climates of the globe. Add to this that water has been made an almost universal solvent ; that from the substances it holds in solution the Crustacea form their shells and the coral polyps build their reefs ; that it fills the cavities of the rocks with gems, and their fissures with useful ores. In connection with this host of wonderful mechanical adaptations, remember that water has been made a chemical agent of great energy and power ; that there have been united in it the apparently incompatible qualities of blandness and great chemical force ; that, although in the laboratory of nature it corrodes the most resisting rocks, it also circulates through the leaflets of the rose and the still more delicate human lungs ; that it forms the greater part of all organized beings, from the lichen to the oak, and from the polyp to man. Reflect, now, that these are only a few of the grosser qualities and functions of this remarkable compound, gleaned here and there from many others no less wonderful, and you will form still but a very imperfect conception of the amount of design which has been crowded into it. Attempt to find a liquid, which, if in sufficient quantity, might supply its place, and you will be still further impressed by this evidence of intelligence and forethought. Of all the materials of our globe, water bears most conspicuously the stamp of the Great Designer, and as in the Book of Nature it teaches the most impressive lesson of His wisdom and power, so in the Book of Grace it has been made a token of God's eternal covenant with man, and still reflects His never-fading promise from the painted bow. TESTIMONY OF CARBONIC DIOXIDE. When standing by some quiet mill-stream, have you ever speculated on the origin of the power which is animating the machinery of the great factory on its banks, spinning and weaving the crude cotton into miles of cloth every week? Or at Niagara, did the thought ever strike you, when gazing up at those floods of water which come tumbling over the rocky cliffs, and plunging into the seething sea at your feet, that similar floods had been pouring over that ancient river-bed for countless ages without diminishing the inexhaustible supply? Or, if it has been at once your privilege and your terror to witness that grandest sight of nature, a violent storm at sea, have you been impressed by the untiring might of that mysterious agent which impels the raging winds and upheaves the roaring billows? Whence can come all the power? and what keeps in motion that wonderful aqueous circulation, which we studied in the last chapter? 164 CIRCULATION OF CARBON. the power to a proximate source in the great central luminary of our system. It is the gentle influences of the sunbeam that raise the water in vapor, and it is the same solar rays that keep in motion the great aerial currents, spreading the clouds over the earth, and distilling their liquid treasures " to satisfy the desolate and waste ground, and to cause the bud of the tender herb to spring forth." Incredible as it may appear, it is actually the sun that weaves the cloth, that feeds the fountains of Niagara, and it is his delicate rays that rule in the tempest and direct the storm. But there are other influences of the sunbeam still more subtle than these, and there are other cycles of changes, as grand as the aqueous circulation, of which the sun is also the ever-active cause. Referring to the table before given, representing the composition of the atmosphere, you will notice that the great aerial ocean contains more than five million billions of tons of an aeriform substance called carbonic dioxide. This amount, although absolutely very great, is nevertheless only a small fraction of the whole atmosphere, making up less than a thousandth part of its total mass. A cubic foot of air does not contain more than a quarter of a grain of carbonic dioxide ; yet there is not one of the atmospheric constituents more intimately associated with organic life, or which discharges more important functions. Although itself a colorless gas, carbonic dioxide consists of ordinary black charcoal combined with oxygen, and these elements are united by one of the strongest affini- ties known in nature ; yet, intense as this force is, the power of the sun is greater, and his rays, acting on the green leaves of the plants, are constantly decomposing the gas and Hberating the carbon, to be incorporated into the various forms of vegetable life. Here, however, it remains only for a brief period ; for when the plants have finished their allotted term of life, the carbon again unites with oxygen, and, in the form of carbonic dioxide, is restored to the atmosphere by the process of combustion or decay. But frequently, before these destructive changes complete the cycle, the carbon undergoes a further transformation, and through the process of digestion becomes a part of the body of the animal. Yet this transmutation, as a general rule, only hastens the final result ; since the processes of animal life are very rapid, and sooner or later the carbon is burnt up in the body, and breathed out into the atmosphere, ready to renew the same series of changes. In this lecture I wish to ask your attention to the evidences of design which may be discovered by studying this wonderful circulation of carbon ; and we shall find that the properties both of carbon and carbonic dioxide have been most carefully adjusted to the part which they play in the great scheme of nature. We might begin our study at any link of this endless chain of phenomena; but to bring the subject into orderly connection with our previous trains of thought, let us return to the phenomena of combustion, which we considered in the third chapter, and study the details of this familiar process a little more closely. All fuel, without exception, contains charcoal, or, as the chemists call it, carbon. Wood, soft coal, oil, wax, similar combustibles, which burn with flame, contain, besides carbon, a variable quantity of hydrogen and oxygen ; but hard coal, coke, and common wood charcoal are almost pure carbon. The adaptations of each of these classes of combustibles demand special notice, and let us begin by studying the evidences of design which are to be found in an ordinary hard-coal fire ; and while, in imagination, we are preparing the fire to be lighted on the grate, we may study with profit some of the external properties of the coal, for even they betray the master-hand of the Great Architect. Examining closely this lump of charcoal, you will notice that it retains all the delicate structure of the wood from which it was prepared. Here is the fibrous bark next the sap-wood, and then the annual rings, all as on a stick of beech ; and if you will take the pains to make a thin section of the charcoal, you will find, on examining it with a microscope, that the minutest cells have been preserved. You know how charcoal is made. The wood is exposed to a high temperature in the charcoal mounds or furnaces, by which the gases which it contains are driven off, while the charcoal, not being volatile, remains behind. Here, then, is a remarkable fact, — that, although the wood has been exposed to a red heat in the process of carbonization, yet the minutest cells have not been destroyed; and it illustrates an equally remarkable quality of charcoal, on which, as we shall see, its usefulness as fuel INFUSIBILITY OF CARBON. 167 very greatly depends. Carbon, in all its forms, is absolutely infusible. It does not even soften at the highest temperatures which can be attained by art, -^nd it is for this reason that the charcoal retains so perfectly the structure of the wood. Were carbon fusible at a red heat, the charcoal would run together into a shapeless mass in the mounds or furnaces in which it is prepared, and did it even soften at this temperature, the forms of these delicate cells could never have been preserved. Viewed in connection with the volatile qualities of the other elements of organized beings, the extreme fixity of carbon in its uncombined condition is worthy of your special attention. The only other essential elements of organic matter are oxygen, hydrogen, and nitrogen ; and these three substances are not only gases, but gases which, even at the lowest natural temperature cannot be condensed to the liquid condition by pressure alone ; yet so strong is the tendency of carbon to remain solid, that it condenses these gases around itself in every organized substance that exists. Carbon is thus the solid substratum of organized matter, the/ skeleton, as it were, of every organic form. How evidently, then, has the attribute of infusibility been adapted to this important function which carbon has been appointed to subserve ! Examining again this lump of charcoal which we are using to kindle the fire, mark that it has a black color and is perfectly opaque. These qualities are so evident to the most superficial observation 1 68 BLACK COLOR AND OPACITY. able as a basis of printing ink. All may not know that printing ink is a mixture of lamp-black and oil, and that the letters on a printed page are formed by thin layers of black charcoal spread over the white paper; and charcoal is peculiarly well adapted for this use, since, however finely subdivided, it never loses its dead black color and perfect opacity. But this property of charcoal would be useless to the scholar for diffusing knowledge, were it not combined with qualities still more remarkable, and almost unique. Carbon is not acted upon by atmospheric agents, and, moreover, is absolutely insoluble in any liquid, with the exception of melted iron. The letters of the first Bible ever printed are as black as they were the day they left the types. They have been exposed to the action of atmospheric air for four hundred years, and, were carbon in the slightest degree acted upon by the atmosphere, they would long since have disappeared. As it is, they will endure as long as the paper on which they are printed lasts. The almost unparalleled insolubility of charcoal is a quality equally important in this relation, for, were charcoal, even to a slight extent, soluble in water, the books of our fathers would have been rendered illegible by the dainpness to which all libraries are more or less exposed ; and were carbon soluble even in such liquids as alcohol, ether, or the volatile oils, the printed page would not have been, as now, safe from alteration, and all kinds of fraud would have been easy. We justly honor the names of Gutenberg and Faust, whose art has done so much to en- PERMANENCY. lighten and civilize the globe, and we'bestoi^due i admiration on those improvements in the aro qL O >^ printing, nowhere more developed than in our owry'^. / land, which have made the press the great agent * // of power, and elevated the moral and intellectual above the physical man ; but while we pay just tribute to the genius of these benefactors of the race, let us not forget that greater Benefactor, who was before them all; for in the most familiar qualities of this piece of charcoal, on which the art of printing so greatly depends, there has been displayed, since the foundation of the globe, an evidence of wisdom and skill before which all human ingenuity sinks into insignificance. But the most remarkable attribute of carbon does not appear in this piece of charcoal ; for of all the chemical elements carbon is by far the most Protean in its aspects, and charcoal is but one of its many manifestations. In the first place, there are the numerous varieties of coal, including charcoal, coke, lamp-black, and bone-black, all having the same general properties, and most of them partaking more or less of the structure of the organic tissues from which they were made. But, besides these varieties, which, although differing so much in their outward aspect, have all essentially the same properties, there are two entirely different states of carbon, differing as much from each other and from common charcoal as any two solids possibly could. Are you aware that the brilliant gem you prize so highly is the same chemical element as these black coals? The diamond is simply crystallized carbon, and although we do not' know certainly how diamonds are made in the great laboratory of nature, yet there is no fact of chemistry better established than this."^ To those who are not familiar with the results of modern chemistry, it seems almost incredible, and even the chemist can hardly believe the truth while he affirms it. It is at utter variance with the former doctrine of his science ; it cannot be reconciled with any of his previous conceptions, and constantly reminds him of the limitations of his knowledge and the uncertainty of his philosophy. And, turning to the more familiar aspects of the subject, how singular the fact, and how typical of the universality of Christian brotherhood, that He, who " hath made of one blood all nations of men,'' should have also made of the same material the priceless brilliant which adorns the diadem of the prince, and the soot which begrimes the cabin of the humblest peasant! How different the estimation in which these two forms of carbon are held ! and yet, if the marks of Divine wisdom can give nobility to a substance, the one is as excellent as the other. But carbon exists in still a third modification, differing as much from the diamond as that differs from charcoal. Every one who has used a common lead pencil is familiar with graphite, and it is a fact as remarkable as the one just noticed, that the same carbon which forms the letters of a printed page fills DIAMOND, GRAPHITE, COAL. 171 also the lines of the pencil sketch. Graphite is simply a modification of charcoal, and if this fact is not so well known as the humble relationship of the diamond, it probably arises from the circumstance that graphite has been generally called plumbago, or black-lead, a misnomer which has given a very erroneous conception of its nature. Graphite is frequently mixed with impurities, but it never contains lead, and in its finest condition it is nearly pure carbon. Compare now graphite with the diamond. Could there be two substances more unlike ? the one the softest of minerals, the other the very hardest ; the one dull and opaque, the other brilliant and transparent. But besides these external differences they have also a different crystalline form, a different specific gravity, a different capacity for heat, and, in fine, excepting that they are both infusible and combustible, there is not one point of resemblance between them. How then, you will ask, do we know that they are both the same elementary substance? Simply because, when combined with oxygen, they both yield the self-same compound. All three of the modifications of carbon are combustible, although they take fire at very different temperatures. Charcoal will burn at a red heat, the diamond at a white heat, while graphite requires the highest temperature which can be attained by art. But however different may be the temperatures required, the process is the same in all cases, and the result is the same. The burning is simply combination with the oxygen of the air, and the result of that combination is carbonic dioxide gas. More- 172 ALLOTROPISM. over, it has been proved by the most careful experiments that a given weight of either substance yields precisely the same weight of carbonic dioxide. Chemically considered, then, the diamond, graphite, and charcoal are the same substance, although, physically regarded, no substances could be more unlike. Chemical identity, therefore, does not consist in identity of properties, and we must admit that the same chemical element may manifest itself under utterly different physical aspects. This remarkable phenomenon, which has been fully recognized only of late years, has been called by chemists allotropismy^ and the diamond, plumbago, and charcoal are different allotropic modifications of the element carbon. Such differences of manifestation, moreover, are not confined to carbon, nor are they exceptional occurrences among the elements. We have already seen that oxygen may exist in an active and in a passive modification, which stand in as striking antithesis to each other as the diamond and charcoal, and the same is true of the different conditions of sulphur, phosphorus, and silicon. Again, these phenomena are not limited to the elementary substances, for they have been observed in many compounds as well, and every year enriches our knowledge with fresh examples. In what, then, are such developments to end ? If substances so utterly unlike as the diamond, graphite, and charcoal are merely modifications of the same element, why may not all substances be merely different allotropic states of a few universal principles, or possibly of only one single essence ? Such, and many similar questions, arise in the mind of the chemist while contemplating these obscure phenomena. They cannot be satisfactorily answered in the present state of chemistry,^ and they throw * The only explanation which we can as yet give of these phenomena is based on the distinction which modern chemistry makes between the molecules of a substance and the elementary atoms of which these molecules themselves are made up. The molecules are the ultimate particles in which the qualities of a substance inhere, and there are necessarily as many kinds of molecules as there are different substances. But there are only as many kinds of atoms as there are chemical elements, and the infinite variety of molecules is formed by the different combinations of the seventy kinds of elementary atoms now known, and chemical action consists in the breaking up of the molecules of the substances which enter into the chemical change and the regrouping of their atoms.to form the molecules of the substances which result from it. It is evident, from this theory, that different molecules — and hence, different substances — may result not only from the grouping of different atoms, and from the grouping of the same atoms in different proportions, but also from the grouping of the same number of the same atoms in different ways. Thus, to take a single example, four atoms of carbon, eight atoms of hydrogen, and two atoms of oxygen grouped in one way form a molecule of butyric acid, while grouped in a different way the same atoms form a molecule of acetic ether, both substances consisting of the same elements united in the same proportions. The same principle may be extended to the elementary substances themselves. They, like compound substances, are aggregates of molecules, which determine their properties, but these molecules consist of atoms of one kind only. Diamonds, graphite, and charcoal are distinct substances, and consist, therefore, of different molecules although in all cases the molecules are formed from carbon atoms only. But although every carbon atom in the universe is exactly like eveiy other carbon atom, yet we may suppose that the differences in a degree of uncertainty and doubt on its whole philosophy. I shall have occasion to dwell upon this subject more at -length in another lecture, and have adduced the facts at this time chiefly as further illustrations of that fertility of resources which so strikingly marks all the results of creative skill. To me this characteristic of the works of nature is one of the most convincing evidences of divinity. While studying the simple adaptation of means to ends which we find everywhere around us, we recognize in the plan something analogous to the creations of human skill, and we almost feel a conscious relationship with its Author. But when we consider this incomprehensible power, by which the same element has been endowed with entirely different and incompatible properties, and not only this, but has been adapted in each condition with equal skill to produce the most opposite and seemingly irreconcilable results, we are also made to feel most keenly that, although man was created in the image of his Maker, he resembles the Divine Original only as the finite can resemble the Infinite. ^ For my thoughts are not your thoughts, neither are your ways my ways, saith the Lord. For as the heavens are higher what we have called the three allotropic modifications of carbon result either from the grouping of a different number of carbon atoms in each case, or from the grouping of the same number in a different way, or from both causes combined. On account of the great hardness of the diamond, and its great density, as compared with the other varieties of carbon, it has been assumed that the molecules of this gem consist of a large number of carbon atoms compacted together. Of all the properties of coal, the one with which we are most familiar is its combustibility ; and while we have been discussing its external properties, the hard-coal fire has been built in the grate, and it is ready to be lighted. The combustion of coal in one or the other of its varieties is the great source of all the artificial heat used by man. Although so entirely passive towards atmospheric agents at the ordinary temperature, yet when heated to a red heat it takes fire and combines with the oxygen of the air with great rapidity. The burning of coal is so familiar to every one that it would seem hardly necessary to dwell upon the subject ' here. But although the experiment is repeated every day in every grate of the city, and although it has been familiar to you all from infancy, there are, nevertheless, phenomena connected with it which few have observed and still fewer fully appreciated. It is a great mistake, but a mistake too frequently made even by scientific men, to suppose that new knowledge can be gathered only from the unexplored fields of science, when by the most familiar walks of life there are countless riches of truth which the reapers in the hurry of the harvest have passed unnoticed, and which will abundantly reward the careful gleaners. In the coal fire on which you daily gaze, there is enough to be discovered to engross the attention of the most diligent student of nature. Let us see, therefore, if we, too, cannot learn something new, at least to us, from the burning coals. The first fact to which I would call your attention is the dfficulty experienced in lighting coal. In order to kindle the fire we have placed on the bottom of the grate, first, some shavings, then some charcoal, and, last of all, the hard anthracite coal. We can readily set fire to the shavings with a match, and they in their turn will ignite the charcoal ; but it requires the intense heat of the burning charcoal to ignite the anthracite. Charcoal will not burn unless at a full red-heat, and hard coal requires a still higher temperature. But notice now another fact : when once inflamed, the heat evolved by the combination of the carbon with oxygen is sufficient to sustain the temperature at the point of ignition. Here, again, we see most admirably illustrated the adaptation of the properties of the chemical elements to entirely different ends. In order that carbon might serve as the solid substratum of all organized beings, it was necessary that it should be made unalterable by the air within the limits of terrestial temperature, but at the same time the economy of nature required that it should be made combustible, that is, endowed with strong affinities for oxygen ; yet these affinities have been so carefully regulated, that they are called into play only at a high temperature, and are thus placed entirely under the control of man. Now that the coal is in violent combustion, combining rapidly with oxygen, notice that it burns entirely without flame. We have here rapid chemical combination, with all the phenomena of active burning, and yet no flame, simply because flame is al- ways burning gas, and in a hard-coal fire it is not gas, but a highly fixed solid, that is burning. Charcoal and anthracite are almost the only combustibles which burn in this way. Most others, even when naturally solids, are converted into gases at a high temperature, and therefore burn with flame ; but carbon in all its forms, when uncombined, persistently retains its solid condition, even in the hottest fire. Remark, also, that this combustion is attended with a very bright white light, and compare it with the more violent combustion of hydrogen, with which most of the audience must be familiar. Hydrogen burns with a flame because it is a gas ; but this flame is almost invisible because gases, however intensely heated, do not emit a bright light. The charcoal burns without flame because it is a permanent solid ; but for this very reason it emits a great amount of pure white light. So far, at least, as ordinary experience extends, white light is emitted only from ignited solid matter.^ Therefore neither white light nor flame is a necessary concomitant even of the most rapid combustion, the first depending solely on the solid, and the last on the I use the phrase white light because an ignited gas or vapor may emit a colored light, and it has been found that the color is in each case determined by the chemical composition of the ignited mass ; but the light emitted from the gases or vapors of which the flames of ordinary combustibles consist, is, at best, very feeble. The light of such flames, as will soon appear, comes almost entirely from solid particles of charcoal, and when these, from any cause, are not present, the flames only yield a very faint, blue light. The appearance of the whole flame is then the same as that which may always be seen near the orifice of a bat-wing gas-burner. 8* aeriform, condition of the burning substance. If, as in the burning of a candle, both flame and white light attend the process, it is because both solid and aeriform matter are there burning; and when we come to examine this phenomenon more closely, we shall find that the result is produced by a most delicate adaptation of properties. Let me next call your attention to the importance of the infusibility of charcoal in connection with its use as fuel. However high the temperature at which it burns, however intense the furnace heat, charcoal never loses its solid condition, and on this wholly depends its application for generating heat. Were coal fusible, even at a very high temperature, it would melt and run out from our grates and furnaces, and the genial fire could not, as now, have been localized on the hearth. The enjoyment of the social fireside is thus closely connected with a familiar property of this wonderful element. But our fire is slowly burning away, and already more than one-half of the coal has been consumed. What has become of it ? Do you point to the ashes ? These are only the earthy impurities, which are more or less mixed with the pure carbon, and constitute but a small fraction of the whole mass of the coal. The carbon itself has combined with the oxygen of the air and formed a colorless and invisible gas, which has escaped by the chimney, which, as I have already stated in the lecture on Oxygen, is called carbonic dioxide. Reflect now on the importance of the circumstance, that this compound of oxygen and carbon is aeriform, and consider what PRODUCT OF COMBUSTION. 1 79 a marked evidence of design and adaptation is to be found in the very fact that the products of ordinarycombustion are invisible gases, which ascend our chimneys and are wafted away by the currents of the atmosphere. As common experience is confined to the burning of coal, wood, oil, and similar combustibles, consisting mainly of carbon and hydrogen, men naturally associate with smoke the idea of a gas, and are apt to think that the aeriform condition is a necessary result of the nature of things. But it is not so. This peculiar provision in the case of carbon and hydrogen is an exception to the general rule. The two combustible elements which are most closely allied to carbon in all their properties — boron and silicon — not only form solids by burning, but two of the most fixed solids known in nature, one of which — silica — constitutes, as we have seen, at least one-half of the rocky crust of our globe ; and the same is true of almost all the other combustible elements. A very interesting experiment in illustration of this fact may be made by burning a piece of phosphorus under a dry glass receiver. The smoke of phosphorus is solid, and it will fall in thick white flakes, producing within the glass the appearance of a miniature snow-storm. Picture to yourself the desolation which would be produced were the order of nature so far changed as to make the products of burning coal like those of burning phosphorus. Every furnace would become a volcano, and we should soon be buried beneath the smoke of our own fires. When, now, we consider that a special provision has been made in the case of that sub- l8o THE PRODUCT HARMLESS. stance whose combustion administers to our wants by evolving light and heat, what evidence does it open to us of the all-wise forethought of the Great Original ! But this is not all. Let me now call your attention to an additional fact in regard to the carbonic dioxide which is escaping from our coal fire. The gas is entirely devoid both of odor and of taste, and, moreover, when in a sufficiently diluted condition it can be breathed with impunity. Consider what an amount of this product is daily formed, and you will then be able to appreciate the importance of this circumstance. The amount of carbonic dioxide which escapes from an average-sized iron blast-furnace in the course of a single hour is equal to at least two tons, and the amount which is generated even by our coal fire is surprisingly large. Moreover, no less than two hundred tons* of this gas are breathed into the air by the population of this city in a single day. If carbonic dioxide had been a pungent or corrosive gas, coal could not have been used as fuel ; for its combustion, like that of sulphur, would soon have rendered the air irrespirable. But so entirely destitute is it of any perceptible odor or taste, that, although it has been evolved in these immense quantities from every fire lighted by man since he appeared on the globe, it so entirely escaped notice that its existence w^as not even suspected until it was discovered by Dr. Black about a century ago. HEAT EVOLVED. l8l There is still another remarkable phenomenon attending a coal fire, which, although it cannot be made evident to the senses, has been substantiated again and again by the most accurate experiments. The volume of carbonic dioxide gas formed by the combustion is exactly equal to the volume of oxygen ^ consumed. It is a consequence of this fact, that the volume of the air is not in the slightest degree increased by the vast quantity of carbonic dioxide gas which is daily poured into it. The gas occupies precisely the same space as the oxygen removed during the combustion, and thus the equilibrium of the atmosphere is not disturbed. It is true that we probably cannot see all the bearings of this simple provision ; but we know enough to recognize in it a most marked evidence of design. The last fact in connection with the coal fire to which I would direct your attention is the large amount of heat which the combustion of coal liberates, and on which its use as fuel very largely depends. One pound of charcoal, in burning completely, generates sufficient heat to raise the temperature of 80.8 pounds of water from the freezing to the boiling point. Every pound of charcoal may, therefore, be regarded as containing sufficient heat to boil eighty pounds of ice-cold water. And have we not another remarkable evidence of Divine wisdom in the fact that carbon, a substance which, on account of its infusibility and other qualities, is so well adapted for fuel, has been 1 82 TESTIMONY OF BURNING COALS. made a great reservoir of heat, from which man can draw an unlimited supply? When we remember that this heat, through the expansion of steam, may be converted into mechanical force, and that hence these beds of coal are not only magazines of heat, but stores of force, which have been accumulating from the foundation of the globe for the use of civilized man, and when we reflect that it is this force which is animating our commerce, weaving our cloth, forging our iron, and impelling the printing-press, how can we express our praise at the foresight of that Providence which endowed coal with such wonderful qualities, made it a vast repository of heat and of force, and then spread it bountifully over the globe? We have discovered all these wonderful indications of design and adaptation in this simple experiment, so familiar as to be almost trite, so frequently repeated as to pass unnoticed, and they are constantly speaking to us of the great Author of nature from the fireside of every home, and from the furnace of every workshop in the land. The followers of Zoroaster still worship, in India, fire as divinity, and regard these burning coals as sacred. Behind this superstition and idolatry there is concealed true wisdom, by which we may well profit. Fire is neither divinity, nor yet its emblem. It has no other reality than as a phenomenon attending a chemical change ; but in the qualities with which carbon has been endowed in order to produce this phenomenon, in the delicate adjustment of forces by which the destructive change SOFT COAL FIRE. 1 83 is confined within due limits, there are indications of divinity which may well make us thoughtful, and consecrate with additional sanctity the family hearth; and if I have succeeded, however imperfectly, in making audible to your intellectual ear this mute eloquence of burning coal, our time has not been spent in vain. I have thus far drawn all my illustrations from the burning of charcoal and hard coal, simply because these familiar forms of fuel are nearly pure carbon, and the phenomena attending their combustion are comparatively simple. They burn, as we have seen, without flame, for the reason that carbon does not volatilize, even at the highest temperatures. It is different, however, with soft coal, wood, oil, wax, and all other combustible materials which are used for generating light. These do not consist wholly of carbon ; but this latter element is always combined with hydrogen, and most of the combustibles named contain also, in addition, a limited amount of oxygen. When heated, they all evolve common illuminating-gas, and for this reason burn with a flame. In fact, the gas we are burning here tonight was made from just such materials. If you visit the gas-works of this city, you will see long rows of iron retorts, firmly built into large brick furnaces. In these retorts the gas is made, and they are connected by means of a complicated system of tubes with all the numberless gas-burners of this large city. Every few hours the retorts are charged with soft coal, which soon becomes heated to a low red heat. At this temperature it slowly gives off 1 84 ILLUMINATING GAS. gas, and it is the gas thus formed which is now illuminating this hall. After three or four hours, the gas has been all driven off, but there is still left in the retorts the greater part of the carbon of the coal, in a condition which is called coke. This is then removed and used for feeding the furnaces, and a new charge of soft coal is introduced in its place. Coke is an excellent fuel, but, like charcoal, it burns without flame. The processes which, in the manufacture and use of illuminating-gas, are spread over a whole city, are united in every soft-coal fire. The gas which is burning at this jet was generated in the retorts of the gas-works, and brought here in iron tubes to be burnt. In the grate the gas is made and burnt in successive moments, but the process is identical in both cases. When you throw a fresh supply of soft coal on the grate, the first effect of the heat is to generate illuminating-gas, which at once takes fire and burns with a brilliant blaze. But after some time the flame ceases, because all the volatile elements of the coal have been expelled, and the coke which is left 'merely smoulders, like charcoal or anthracite. What is true of soft coal is also true of wood and of all this class of combustibles. Flame, as I have before stated, is in all cases burning gas. As we are generally familiar with it, flame is a cloud of illuminating-gas combining on its exterior surface with the oxygen of the air. In a gas lamp the gas is supplied ready made at the jet. In an oil lamp or a candle, the gas is manufactured as fast as it burns. The use which we make of the flame, in all these cases, is to generate light, and the qualities of carbon have been most admirably adjusted to produce that result. This is the point which I wish next to illustrate, and we shall understand this beautiful example of adaptation more readily by analyzing the burning of some one of the light-generating materials. I will, therefore, select a common wax candle as my example, because it is familiar to every one, and illustrates all the points I have in view. Nothing could be simpler than the candle itself. It is a long cylinder of wax formed around a string made of loose cotton threads, which we call the wick. The wax, that familiar secretion of the honeybee, is composed, chemically, of carbon, hydrogen, and a little oxygen ; the wick, as the microscope would show us, is merely a collection of fine vegetable tubes. Let us now light the candle. For that purpose we apply the flame of a friction match to the end of the wick, and mark the result. The heat of the match melts the wax around the base of the wick, and now the peculiar virtue of these vegetable tubes come into play. All fine tubes have the power of sucking up liquid, and the finer the tube, the greater the height to which the liquid is thus elevated. The tubes of the wick act in this way, and the melted wax is at once drawn up to the flame of the match. There it is volatilized by the high temperature, and a cloud of red-hot combustible gas forms around the summit of the wick. Like the rain-drop, or any other fluid body in a free state, it assumes a spherical form, but being much lighter than the air, this sphere of gas no sooner forms than it begins to ascend, and, being very combustible, is burnt up by the oxygen of the air with great rapidity, so that before it has risen an inch from the wick it is reduced to a point. Meanwhile, however, the first sphere is followed by others, which in rapid succession meet with the same fate, and at any moment we have a large number of these little spheres, one above the other, rapidly diminishing in size from the lowest to the highest, which has then become a mere point. Hence results the familiar conical form of the flame. But our match is long since burnt out, and what, you will ask, now volatilizes the wax ? Solely the heat evolved by the burning gas. This heat converts the wax into vapor as fast as it creeps up the wick, and thus the flame being constantly supplied with combustible gas, the candle continues to burn until it is all consumed. The candle-flame is, then, merely a cone of volatilized wax, rapidly combining on its exterior surface with the oxygen of the air, and as rapidly replenished from below by the constant conversion of fresh wax into vapor. In this process light and heat are evolved ; but these are generated solely on the exterior surface of the flame, where the burning takes place. Within it is perfectly dark, as can be easily shown by pressing down upon it a piece of window glass, through which the interior may be seen. Let us now study this chemical process more carefully, as the whole illuminating power of the flame depends on a very delicate play of aflinities. posed essentially of charcoal and hydrogen. The light and combustible hydrogen has so great a tendency to retain its aeriform condition, that, when combined with carbon, it renders even this, the most fixed of all the elements, aeriform ; but the moment the bonds of chemical affinity are loosened, the carbon resumes its solid condition. Such a change takes place in the flame, and it is the particles of solid charcoal thus liberated that render it luminous. Of the two elements of the gas, hydrogen has the greatest affinity for oxygen, and therefore burns first, momentarily setting free the carbon, which is sprinkled in a fine powder through the burning gas. This is at once intensely heated, and each glov/ing particle becomes a centre of radiation, throwing out its luminous pulsations in every direction. The sparks last, however, but an instant ; for the next moment the charcoal is itself consumed by the fierce oxygen, now aroused to full activity, and nothing but a transparent gas rises from the flame. But the same process continues ; other particles succeed, which become ignited in their turn, and hence, although the sparks are evanescent, the light is continuous. Thus it appears that all our artificial light, the light which we are enjoying this evening, depends upon this provision, by which the particles of charcoal linger for a moment in the flame before they are burnt. Let me again repeat, white light is emitted by ignited solid matter. The flame of pure hydrogen gives very little light, because there are in it no solid particles, and were the affinity of oxygen LIGHT OF THE FLAME. for carbon slightly greater than at present, the flame of the candle would be as little luminous : then the carbon would burn simultaneously with the hydrogen, and there would be no pulyerized charcoal in the flame to radiate light. On the other hand, were the affinity of oxygen for carbon a little less than at present, the carbon particles would not burn in the flame, but would escape from it in clouds of dense soot. Our Heavenly Father has so carefully adjusted the relative affinity of oxygen for the two elements of these light-giving gases, that the hydrogen should burn a small fractional part of a second before the carbon. During this brief interval of time, imperceptible to our unaided senses, the solid particles of charcoal are set free, become ignited, and give motion, perhaps, to a single wave of light ; but the instant after, they too rush into combination with the great fire-element, and not a particle is left to dim the transparency of the air. The smallest variation in either force would destroy the adjustment by which this result is produced, and our lamps and candles would cease to give their light. How delicate the adjustment ! How beneficent the result ! How evident the design ! To me the marks of Gods designing hand are more conspicuous in that familiar candle-flame than in the grand cycles of astronomy, or in the wonderful mechanism of the human body. I return to it again and again with renewed confidence, and always find fresh satisfaction and increasing faith. There are many who believe, with Laplace, that this glorious system of suns and planets, with all its complex movements and adjustments, might be evolved out of a nebulous chaos by the sole action of the primary laws of motion ; and now, after the great French mathematician has furnished a world to begin with, a modern naturalist asks us to believe that this hand of mine, with all its wonderful combination of nerves, bones, and muscles, was developed out of the claw of an animalcule, or some such thing, by what he calls ^^ the law of natural selection ; " and although these and similar theories may be held consistently with a belief in a Divine Disposer, yet it is too true that to many of their advocates the order of nature signifies nothing higher than self-existing matter, directed by inexorable necessity. But no cosmogonist has been able to go behind the chemical elements, and until human philosophy can show how these forms of matter, with all the marvellous adjustments among their properties, have been evolved out of the " star dust '' of the original chaos, or out of nothing, and can adjust by natural causes the delicate play of forces in that most familiar of all phenomena, a candle-flame, it will not be able to overthrow the evidence of design afforded by this genial winter-evening light. The fact that these would-be world-makers explain most satisfactorily what men know least about, is, it must be confessed, not in favor of their theories. Yes, my friends, it is these most familiar evidences of design which are the most impregnable against the attacks of materialism. It is these household altars that we find always burning to enlighten our dull understanding, to disperse our gloomy for carbon has been adjusted appears still more /wonderful when we consider another of the uses of this force in nature. The useful metals, which may be said to be the tools of civilized life, are seldom found in nature in a pure state. They generally occur combined with oxygen, and this compound, which is called the ore of the metal, is found in beds or veins of the rocks, where it has been deposited through the agency of water. After the miner has dug out the ore from the earth, and washed it free from impurities, it is the business of the smelter to melt out the pure metal. Now in this ore the metal is combined with oxygen, and unless the smelter could break this bond, the highest temperature of his furnace would be unavailing. But the merciful Parent of mankind, when he thus locked up these his choicest gifts, gave to man a key which would unlock the treasure-house, but left him to find out. its use ; and as in the progress of humanity the metals were required to advance civilization and multiply the comforts of life, the secret was discovered, and the treasures one by one were brought to light. This needed key was charcoal. The Creator has endowed carbon with a power so strong, that it readily overcomes the force by which the metals are united to oxygen, and by simply heating the ore with charcoal the metal is set free. Would that I could give you an idea of the strength of the force which is required to pro- duce this result. The affinity of carbon for oxygen is one of the most powerful forces known in nature, so great as to be immeasurable by our ordinary human standards, and yet it is this same force which produces that delicate result, the light of a candleflame. With such wonderful skill does God wield these mighty agents of his power. Consider, finally, how this power of reducing the metallic ores has been united in charcoal to those other qualities which render it so valuable as fuel. The smelter heats his furnace with the self-same coals which reduce the ore. These coals remain unchanged in contact with the ore until they have done their work, and then are converted into a colorless and harmless gas, which escapes by the chimney and is wafted away by the air; while, on the other hand, the melted metal, freed from its long imprisonment, flows out below in glowing streams, ready to be cast into thousands of useful forms. Review now, for a moment, the qualities of carbon, and notice how manifold and important are the functions which this element has been appointed to subserve. It has been made hard and brilliant, for the glazier's diamond and the monarch's crown. It has also been made soft and black, for the artist's pencil and the printer's ink. It has been made indestructible by atmospheric agents, and thus has preserved for us the wisdom of past ages, and will transmit our bequests of knowledge to those that are to come. It has been made combustible, and at the same time infusible, in order to localize our fires and 192 SUMMARY. confine them within their appointed bounds. It has been made a great reservoir of heat, in order that it might protect us from the winter's cold, and shed its enlivening warmth around the family hearth. It has been endow^ed with a strong affinity for oxygen, in order that it might reduce the metallic ores ; but at the same time this affinity has been so carefully adjusted that the carbon particles linger in the flame for a moment before passing into invisible gas, and thus become a source of light as well as of heat. Lastly, the product of its combustion is a gas so transparent that it does not even cloud the atmosphere, and so bland that it bathes the most delicate organisms without harm. What an array of evidence have we here ! But this, my friends, is only the first stage of that grand circulation of carbon in nature, which we proposed to ourselves as our subject this evening. The product of all these various processes of combustion is carbonic dioxide, and let us now follow this gas into the atmosphere, and examine some of its more familiar qualities. Carbonic dioxide is so perfectly transparent and so devoid of every active quality that its presence cannot be recognized by any of our senses, and we must therefore call in the aid of experiment to make evident its existence. This is the reason why it remained so long unknown, the method we now use for detecting its presence having been first discovered by Dr. Black only a little more than a century ago. The method is very simple. Carbonic dioxide has a great tendency to combine with lime, and the CARBONIC DIOXIDE. I93 result of this combination is the familiar white solid called chalk. Now lime is, to a certain extent, soluble in water, while chalk is insoluble ; and hence, if lime-water is exposed to an atmosphere containing carbonic dioxide, the formation of particles of chalk, rendering the transparent solution turbid, will indicate the presence of the gas. Such a result is actually obtained by exposing lime-water in a saucer for a few days to the atmosphere, and any one can convince himself by this simple experiment of the existence of carbonic dioxide in the medium around us, as well as in the air which is exhaled from the lungs. Indeed, the breath is so loaded with this product of combustion that lime-water is rendered milky by blowing into it for only a few minutes. The quantity of carbonic dioxide in the atmosphere, however, is relatively very small, not amounting to more than a few ten-thousandths of its whole weight. It enters to a far greater extent into the composition of many rocks. All limestones have the same composition as chalk, and contain nearly one-half of their weight of carbonic dioxide, rendered solid by the force of chemical affinity. These rocks, indeed, are the great reservoirs of this aeriform compound, and when you consider how. widely the limestones are distributed, underlying whole districts of country, reaching down to unknown depths, and piled up into vast mountain chains, you can form some appreciation of the extent to which carbonic dioxide gas was used in laying the foundations of the globe. the epiglottis to close spasmodically and producing immediate death by asphyxia. When so far diluted as to admit of being received into the lungs, it acts like a narcotic poison, causing drowsiness and insensibility, and this even when a candle will burn in the gas. Carbonic dioxide is not, however, poisonous in the strict sense of that term. On the contrary, it is always present in the blood in large quantities, and with it bathes all the tissues of the body. The carbonic dioxide results, as we have seen, from that slow combustion constantly going on in the blood, by which the animal heat is maintained, and it is an essential condition of life that this product should be secreted from the body as fast as it is formed. If the atmosphere contains more than a small percentage of the gas, the process of secretion is arrested, and fatal results necessarily ensue. The density of carbonic dioxide is much greater than that of either of the other constituents of the atmosphere, the same volume weighing one-half as much again as common air. Indeed, it is so heavy that it .can be poured from one vessel to another like water, and the immense volumes of carbonic dioxide which are constantly flowing from our lungs and furnaces would cover the whole surface of the earth with their deadly vapor, were it not that the Creator has provided, by those simple laws of diffusion, which we studied in a former chapter, that this noxious gas should be dispersed as fast as generated, and so mixed with the great mass of the atmosphere as to be rendered harmless by extreme dilution. The unfortunate accidents which sometimes occur to persons who descend incautiously into cellars or wells, where the carbonic dioxide is generated more rapidly than it can be dissipated, constantly remind us that the existence of animal life on the globe depends upon this beneficent provision. The large kilns in which lime is burnt into quicklime are constantly pouring out streams of carbonic dioxide gas, and more than one poor, houseless wanderer, attracted by the heat of the kiln, has laid down to rest in the stream, and slept to wake no more. Were the force of diffusion much less than it is, we should all be constantly exposed to a similar fate ; and when we lie dow^n at night, it is only this guardian angel which prevents the deadly fumes of our own fires from descending on our beds. Carbonic dioxide is soluble in water, a given volume of this liquid being capable of absorbing its own volume of the gas, irrespective of the temperature or pressure. We should therefore expect to find carbonic dioxide in solution in all water exposed to the air, and in fact a cubic foot of river, lake, or ocean water generally contains a very mucJiT greater amount of this gas than an eqiial volume ofthe atmosphere. Water, when holding carbonic di-? oxide in solution, has its solvent power very greatly increased. It then dissolves, in large quantities, all the varieties of limestone, and even granite rocks cannot wholly resist its action ; but these solutions, when exposed to the air, gradually lose the carbonic dioxide, and with it their solvent power, incrusting with calcareous matter the moss, the twigs, or the walls of caverns on which the liquid may chance to rest. It is the solvent power of such water, acting slowly through ages of time, that has hollowed out that immense cavern in the limestone strata of Kentucky, and it is from the solution thus made that those stalactitic ornaments have been formed which add so much to its beauty and interest. It is also this same agency which in other places has deposited beds of calcareous tufa over great areas, and cemented together loose sands into firm rocks ; and, finally, it is from the lime dissolved in the water of the ocean, that the Crustacea form their shells and the coral polyps build their reefs. The origin of carbonic dioxide is the same in water as in air. In the water we have not, of course, active combustion ; but this, as has been shown, is an insignificant source of carbonic dioxide when compared with the never-ceasing functions of respiration and decay, and these are as active in the rivers, the lakes, and the oceans as in the atmosphere. Moreover, the purpose which the carbonic dioxide subserves is the same in both cases, and this demands our attentive study. I have already intimated that carbonic dioxide is one of the few articles of which the food of plants consists. Let us trace, for a moment, the history of the plant. The seed containing the germ is placed in the soil. The genial warmth of the sun calls it into activity, and it shoots forth its small leaflets * The whole peninsula of Florida has been in great measure built up by these little animals with the lime rock which the waters of the Mississippi pour into the Gulf, and which has been dissolved from the lime deposits of our Western States. FOOD OF PLANTS. I97 into the air. For a short time the small stock of starch and similar nourishment stored in the seed by a wise Providence serves for its support ; but this is soon exhausted, and for the future the plant must depend for its food upon the soil and upon the air. The articles which compose its diet are exceedingly simple. They are water, carbonic dioxide, and ammonia, substances always present in the atmosphere and in every fertile soil. As soon as the young plant has expanded its green leaves it absorbs these substances, partly through its rootlets from the soil, and partly through its leaves from the air. The leaf, a tissue of minute organic cells, is the laboratory in which, from these few compounds, are elaborated the different organs of the plant. The sun's rays, acting upon the green parts of the leaf, give them the power of absorbing water, carbonic dioxide, and ammonia, and of constructing from the materials thus obtained the woody fibre, starch, sugar, and other compounds of which the plant consists. We have analyzed the woody fibre, and we know that it is composed of carbon and water. Twenty-seven ounces of wood contain twelve ounces of carbon and fifteen ounces of water. Moreover, the amount of carbon required to make twenty-seven ounces of wood is contained in forty-four ounces of carbonic dioxide. If, then, we add together forty-four ounces of carbonic dioxide and fifteen ounces of water, and subtract from this sum thirty-two ounces of oxygen, we shall have just the composition of wood. This is what the sun's light accomplishes in the water to form the wood. What I have stated to be true of wood is equally true of starch, gum, sugar, and most of the products of vegetable life. All these, with a few exceptions, which I shall notice in the next lecture, are prepared by the plant from carbonic dioxide and water, under the influence of the suns light. Why it is that starch is deposited in the cells of the potato, sugar in those of the sugar-cane, and gum and woody fibre, more or less, in all plants, we do not know. These are the mysteries of organic life which no science has been able to solve. This much, however, is certain. The acorn, buried in the ground, grows into the noble oak. Of that wide-spreading tree, at least nine-tenths consist of carbon and water. The water is absorbed, as such, directly from the atmosphere ; the carbon was recovered from the carbonic dioxide decomposed by the sun's rays. Here is the wonderful fact. The gentle influences of the sunbeam have the power of reversing the process of combustion, of overcoming the intense affinity of the fire-element, tearing it apart from the carbon, and restoring it to the air. How great this power is, I have already endeavored to illustrate. I have stated that the affinity of oxygen for carbon is one of the strongest affinities known to nature, immeasurable by any human standard. In order to decompose carbonic dioxide in our laboratories, we are obliged to resort to the most powerful chemical agents, and to conduct the process in vessels composed of the BURNING REVERSED. 1 99 most resisting materials, under all the violent manifestations of light and heat, and we then succeed in liberating the carbon only by shutting up the oxygen in a still stronger prison ; but under the quiet influences of the sunbeam, and in that most delicate of all structures, a vegetable cell, the chains which unite together the two elements fall off, and while the solid carbon is retained to build up the organic structure, the oxygen is allowed to return to its home in the atmosphere. There is not in the whole range of chemistry a process more wonderful than this. We return to it again and again, with everincreasing wonder and admiration, amazed at the apparent inefficiency of the means, and the stupendous magnitude of the result. When standing before a grand conflagration, witnessing the display of mighty energies there in action, and seeing the elements rushing into combination with a force which no human agency can withstand, does it seem as if any power could undo that work of destruction, and rebuild those beams and rafters which are disappearing in the flames ? Yet in a few years they will be rebuilt. This mighty force will be overcome ; not, however, as we might expect, amidst the convulsion of nature, or the clash of the elements, but silently, in a delicate leaf waving in the sunshine. And this is not all. Those luminous waves which beat upon the green surface of the leaf are there arrested, and their moving power so completely absorbed, that the reflected rays will not even affect the exquisitely sensitive plate of the photographer. But the power of the light has not been lost, and 200 ORIGIN OF COAL. when the wood is burnt and the carbon converted back into carbonic dioxide, this power reappears undiminished in the heat which radiates from the burning embers. The heat, therefore, which the wood contains, and which it gives forth on burning, comes from the sun. What a beautiful provision of Providence have we here ! During the summer, when the sun is warming us with his genial rays, he is also laying up in the growing wood vast stores of heat, with which to warm us at the winter evening fireside, when his rays have been withdrawn. But you will tell me, it is not wood, it is coal which is burning in the grate, and you will lead me, perhaps, to the mouth of some black coal-pit, and ask if those dismal regions below ever saw the sun. Certainly! and it is one of the most remarkable revelations of modern science, that the stone-like coal was once alive. Coal is the remains of an ancient vegetation, which flourished on the earth ages before man first walked in Eden. The process by which it has been formed and buried in the earth is well known. You can see it now forming in many tropical swamps. There you will find a vast mass of vegetable matter, the result of a rank vegetation, gradually decaying under water. The land is slowly sinking, and as this bed of peat sinks with it, it becomes covered with mud and sand, which numerous streams are constantly washing into the swamp. Thisgoes on year after year, century after century, age after age, until the bed is buried hundreds of feet beneath the surface. In the meantime the vegetable tissues undergo a sort of internal com- bustion, similar to that which takes place in a charcoal mound. Wood consists, you will remember, of carbon and the elements of water. The oxygen which it contains reacts on the carbon and hydrogen. Carbonic dioxide and water are formed, which escape, while the rest of the hydrogen and carbon unite together to form the coal. The reaction is a true process of combustion, and the heat thus evolved aids the chemical change, and gives to the coal its baked appearance. This change it requires long ages to complete. Millions and millions of times has the earth repeated its annual revolution around the sun, and the whole external appearance of the globe has changed since those mighty forests grew, which have been petrified in the coal. But though such long intervals have elapsed, their history has not been lost. It has been written on the rocks, the mighty monuments of past ages. The geologists have read it, and we know with as much certainty the form of the leaves and the structure of the stems of those ancient trees, as we do those of the oak or the chestnut. We know, also, that every atom of coal which now lies buried hundreds of feet beneath the surface was once a part of the atmosphere, and that the heat which it evolves by burning was received from the sun, when the carbonic dioxide was decomposed by the light in the leaves of the ancient trees. Consider for a moment of what immense value to man are those beds of coal. Without them modern civilization would have been impossible. Remember that since the dawn of creation the sun has been employed in accumulating 202 PREPARATION FOR MAN. these vast stores of force, and thus preparing the globe for civilized man. We may admire the genius of a Papin and a Watt, who have told us how to use this force, and who have thus covered the ocean with steamships and the land with railways; but let us not forget that infinitely greater wisdom which saw the end from the beginning, and before the mountains were brought forth, or ever the continents were formed, laid up the beds of coal in the early strata, and preserved them through the long ages of geological time until the earth had become fitted to be the abode of man. I have now glanced at some of the distinctive features of the great circulation of carbon in nature, and have endeavored to show that the sun's rays are the prime moving power of the whole. I trust that you have been impressed with the grandeur of its cycles, the delicacy of its adjustments, and the mighty power of that mysterious influence by which it is sustained ; but above all, that I have succeeded in making clear to your intellectual vision those marks of wisdom and of power which have been so visibly stamped upon this Divine economy. In order to complete my very imperfect sketch of the wonderful adaptations which the various qualities and functions of our atmosphere present, I wish in my lecture this evening to examine with you the properties of nitrogen gas. This aeriform substance is the chief constituent of the air, making up no less than four-fifths of its entire mass, and, although so seemingly inert, discharges functions no less important than those of oxygen gas to the well-being of man. Nitrogen is not, however, like oxygen, an element widely distributed in nature, and entering as a chief constituent into the composition of the globe. The atmosphere is the only great reservoir of nitrogen, and to this and to the bodies of organized beings its presence is almost exclusively confined. It seems to be the essential element of all the higher forms of corporeal vitality, and it is frequently called the zoogen, or life-generator. By some mysterious process it is constantly being withdrawn from the atmosphere, and entering into the composition of the numberless living forms which clothe the earth with verdure and crowd it with animal life ; but these forms soon pass 204 LIMITED DIFFUSION. away, and by the inevitable process of decay the nitrogen is restored to the great reservoir from which it was originally withdrawn. Science has not, as yet, been able to follow all the steps of this remarkable process ; but, nevertheless, enough is known to show that the properties of nitrogen have been most admirably adapted to the numerous important ends which it has been, appointed to subserve. Nitrogen is, then, peculiarly the element of the atmosphere. It not only constitutes the greater part of the aerial ocean, but it exists there in a perfectly free and uncombined condition, and — with the self-limiting exception just noticed — is found nowhere else. We should naturally expect to find in nitrogen gas, occupying so important a place as it does in the scheme of creation, a substance full of the highest interest. Yet nothing could be less inviting than its external properties. A permanent gas, even at the lowest temperatures, without color or odor, it is entirely devoid of every active property. It will extinguish a candle immersed in it, and will not sustain animal life : but these are merely negative qualities ; for animals cannot live in an atmosphere of nitrogen, solely because it does not contain oxygen, and it will not support combustion because it is not endowed with active affinities. Moreover, in all other outward aspects nitrogen is equally inert. It exerts.no action whatever upon the most delicate chemical compounds, and, with a few unimportant exceptions, will not enter into direct combination with any of the chemical elements. Consider also the nitrogen as it exists in the atmosphere. Al- SINGULAR INERTNESS. 205 though in immediate contact with the most violent of the elements, and exposed to its action when in its fiercest state, under the varying influences of light, heat, and electricity, yet no combination between the two results, except to a very limited extent, and under pecuHarly oblique conditions. Through an ordinary iron blast-furnace there pass, in the course of a single day, many tons of this mixture of nitrogen and oxygen called air. The oxygen, as we know, causes the most violent chemical action; but although the nitrogen is brought into contact with the same intensely heated coal and iron, no combination, at least of any importance, ensues. Shall we then conclude that nitrogen is entirely unendowed with chemical affections, — that it is capable of forming no compounds, and of producing no powerful effects, — that it is, in fine, a mere dead weight in the atmosphere, placed there, for the want of something better, to fill up the void and to give the required density, as a ship is frequently loaded with ballast when there is a lack of freight? Such is the conclusion to which the appearances would naturally lead, and such is the conclusion at which the chemists arrived in the early stages of their inquiry. Yet no inference could be more at variance with actual facts; for so far is it from true that nitrogen is the uninteresting substance which these negative qualities would seem to indicate, that there are but few elements which form a larger number of compounds, or which are endowed with more varied powers when the necessary conditions of combination are fulfilled. Nitro- gen can be made to unite with the other elements only by indirect and circuitous processes. It is one of its most distinctive qualities to avoid direct combination; but when the necessary conditions are present, it surprises us by the readiness with which it combines, and by the great variety and remarkable character of the resulting compounds. When we should least expect it, we find, not single compounds, but whole classes, springing into existence, which, while they often defy our investigations by their Protean and 'complex character, yet in other cases excite our admiration by the simplicity of their constitution and by the beauty of the plan according to which they have all been fashioned. The points, then, which especially characterize nitrogen, and in which the evidences of design in its constitution are to be traced, are, first, its unexampled inertness when in a free condition ; secondly, the variety and remarkable nature of its compounds ; thirdly, the peculiarly oblique processes by which all these compounds are formed ; and, lastly, their very great instability. Nitrogen may be very appropriately termed the ballast of the atmosphere, and this is undoubtedly the most obvious of its functions. Air, you will remember, is not, in any proper sense of the term, a distinct substance. It is a mixture of several substances, or rather there coexist around the globe at least three different atmospheres — one of nitrogen, one of oxygen, one of aqueous vapor, and perhaps we should add, as a fourth, one of carbonic dioxide — each with its own peculiar characteristics, and so entirely distinct that it would ret^in^^^its essential properties were the rest removed." -^.Agai<y when/' >, studying in our fifth lecture the general feature^' pf the great aqueous circulation on the earth, we dtsi / covered that the whole plan turns on the fact that " I. the atmosphere of aqueous vapor is mixed with a large mass of other aeriform matter, which moderates all atmospheric changes and mitigates the violence of their effects. It also appeared in the third lecture that the atmosphere of oxygen had been subjected to a similar restraint, and that the aroused energies of this terrible destroyer had been most carefully tempered by great dilution. As the atmosphere is constituted, the oxygen cannot reach the burning combustible without carrying with it the whole mass of the surrounding air ; but if this mass of aeriform matter were not present, the devouring element would rush upon its prey with a fury which nothing could withstand, and iron^ would burn as readily as straw. Moreover, in several other connections we have shown that it is an essential condition in the scheme of terrestrial nature that the air should have its actual density. See now how beautifully all the conditions are fulfilled in the atmosphere. The proportion of oxygen has been most carefully adjusted to the necessities of animal life, and made so small that the violence of the fire-element may be restrained within due limits. The amounts of aqueous vapor and of carbonic dioxide have in like manner each been accurately adjusted to the purposes 208 SPECIAL RELATIONS. which they were appointed to subserve, and then, in order to make up the required density, a large mass of a perfectly inert gas has been added. Thus in the very inertness of nitrogen we find the most obvious evidence of adaptation. Its negative qualities are precisely those required in a substance which is designed to act as so much dead material, adding to the density of the atmosphere without interfering with the functions of its active agents. Consider, also, how very greatly this evidence of design is enhanced by the fact that nitrogen is found only in the atmosphere and in the bodies of organized beings, into which it has been temporarily withdrawn. It is not, like oxygen, carbonic acid, or water, a main constituent of the globe, and cannot therefore be regarded, as the fatalists would have us believe, as so much material left over after the solid globe had been condensed by the molecular forces from a chaotic nebula. Nitrogen is not only exactly adapted to the functions it subserves in the atmosphere, but, moreover, these are its only uses, and I cannot see how it is possible to resist the conclusion that it was especially designed for the place it fills. That you may appreciate the strength of this evidence, let me illustrate the subject by an example from common life, which will be more to our purpose than a philosophical analysis of the argument itself. It does not follow that the square granite blocks which form the greater part of the front of yonder magnificent warehouse, however well adjusted they may be, were actually cut with reference to this building, although the strong presumption is that they were. Nor does it follow that those highlyornamented window-caps and that elaborate cornice were originally designed for this particular edifice, although the presumption that such was the case is still stronger than before. Nay, more, it is not even absolutely certain that those skilfully carved ornaments which adorn the front, and are built into the walls, were originally intended to be placed where they are, although to doubt this conclusion would be the extreme of incredulity. I admit, it is barely possible that they were originally made for another building, rejected, perhaps, for some defect, and afterwards put up here. But I will show you where there is an evidence of design in the building-material of this warehouse which you will be forced to accept. It is not conspicuous, and might be overlooked. Just here at the corner of the building there is a very peculiarly shaped block of stone. You never saw one like it before. This extraordinary shape was required by the peculiar form of the building lot and the position of the walls on the adjoining estate. The sides of the lot are not perpendicular to the front, and the block has been cut to the precise angle of the bevel, and at the same time exactly fits the adjacent walls. The conclusion that this block was designed for that place is irresistible. No sane mind would doubt it for a moment. I do not say there is not one chance in many millions, estimated on the doctrine of probabilities, that a block of this exact size and shape might have been found among the refuse stock of the stone-cutter's yards ; but I do say, that, in the absence of absolute proof to the contrary, the certainty that this granite block was wrought with reference to the place it fills, and that the exact correspondence of its dimension and angles was the result of measurement, is as great as it is possible to attain by any process of reasoning short of a mathematical demonstration; moreover, it is as great as can be obtained in physical science, or in any department of human knowledge one step removed from the facts of consciousness or of observation. The evidence that nitrogen was designed for the place which it fills in the atmosphere is vastly stronger than this. The force of the argument in the illustration just cited evidently increases very rapidly the more singular the shape of the granite block, and the more accurately its form has been adjusted to the place it fills. Now nitrogen is as unique among the chemical elements as water is among the compounds. Its external properties are so entirely different from those even of the class of elements to which it belongs, that chemists can hardly believe that it is a simple substance, and for the last fifty years have been vainly attempting to decompose it ; but it has resisted all their efforts, and the more intimately they have become acquainted with its properties, the more singular and exceptional it has appeared. At the same time, while presenting these remarkable anomalies, nitrogen has been fitted to the unique place which it fills in the scheme of creation, with a nicety and precision which it is as much beyond our powers of thought to conceive, as it is beyond my feeble language to describe. It is not only that one or two of the corners of this block of nature's edifice have been bevelled to an exact angle, but it has been adjusted at every point to the ten thousand conditions of that comple:?^, structure I have been imperfectly describing during this course of lectures, with a skill immeasurably beyond all human art, and with an intelligence which " looketh to the ends of the earth and seeth under the whole heaven." If this be so, — and you will find that my guarded expressions fall far short of the truth, — why not use in these matters of faith the same common sense which w^e apply with so much success in common life, and which in our daily intercourse it would be nothing short of madness to disregard? We do not hesitate to trust the skill and honesty of a fellow-man, whom we not only have never seen, but even as to whose character our sole evidence is the most indefinite testimony. Why, then, not accept the precious and comforting truths of religion, and repose equal faith in the providence of our Heavenly Father, on evidence which, we must admit, is ten thousand-fold stronger, and when we have everything to gain, and nothing to lose ? Is it said. There is still room for doubt ? Of course there is. God be thanked ! there is no relation in life in which there is not doubt. Were there no doubt, there would be no faith, no trust, no confidence, no love ; the heart would be absorbed in the intellect, religion would become an axiom, and morality a formula of mathematics. Use but one-half of the observation, one-half of the inteUigence, which are never at fault in the business of life, and these marks of the Creator's wisdom and providence which lie all around us will become as evident as the sun. Act on this evidence, and the door of grace will be opened, new light will stream into th^ soul, and all nature will be seen radiant with a Father's love. All this striking evidence of design and adaptation we have discovered in the most obvious of the attributes of nitrogen, — in those merely negative qualities in virtue of which it increases the density of the atmosphere without interfering with the functions of its active constituents. It would not, however, be in accordance with that economy of resources which we find everywhere in nature, that the uses of nitrogen should be limited to this single object ; and after what we have already seen to be true in the case of oxygen, we shall not be surprised to find this singular element suddenly changing its character and appearing in a new condition. The second point, as you will rem.ember, which I am to illustrate in regard to nitrogen, is the variety and remarkable nature of its compounds, as well as the singularly oblique processes by which they are formed ; and, having examined the marks of design it bears in its first manifestations, let us now study the no less impressive evidence presented by the second. It would be entirely out of place in a popular work like the present, to describe in detail any of the countless nitrogenized compounds which are known to chemistry, and it would require a separate volume merely to illustrate the COMPOUNDS OF NITROGEN. 21 3 characteristic features of the great classes into which they may be subdivided. I shall be able only to glance at a few general facts which illustrate the point now under discussion, and also the part which nitrogen plays in organic nature. Although nitrogen presents such an indifferent exterior towards the oxygen of the atmosphere, it can, nevertheless, be made to combine with it by resorting to certain oblique processes, and there may thus result no less than five different compounds. Every one is familiar with that highly corrosive liquid called nitric acid, and this is formed by the union with water of one of the compounds in question. Under certain conditions this acid results from the union of the oxygen, nitrogen, and aqueous vapor which are mixed together in the air. Indeed, the only essential difference between the bland atmospheric air and this highly active chemical agent consists in the fact that while in air the elements are only mixed together, in the acid they are chemically combined. Were nitrogen to be suddenly endowed with the active affinities which from its position among the chemical elements we might naturally expect it to possess, then nitric acid would be formed in the atmosphere in large quantities, and it is only the unexampled inertness of nitrogen which prevents a result which would be fatal to all organic life. But although so corrosive when pure, nitric acid when immensely diluted is one of the few materials which nourish and sustain the plant, and therefore provision has been made that it should be formed in the atmosphere, but 214 HOW PRODUCED. only under very restricted conditions, and to a very limited extent. When electrical sparks are passed through a confined quantity of air, in the presence of some alkaline substance, such as potash, soda, or lime, a very partial combination takes place between the two elements, and an infinitesimal quantity of nitric acid is formed. So, also, when organic matter decays in the presence of these same alkalies, a similar combination, although to a very slight extent, results. Nitric acid is endowed with such violent affinities that it doiSs not remain in a free state. It at once enters into combination with the alkalies, forming a class of salts, of which saltpetre is the best known example, and from which the common nitric acid is extracted for the uses of the arts. Nitrogen, you will notice, acts here very much like a self-willed child. All the powers of nature cannot compel it to combine directly with oxygen ; but if you offer to it these alkalies as an inducement, and make your approaches sufficiently indirect, you can coax it to combine, and nitric acid is then formed. We do not understand how the peculiar conditions just mentioned conspire to produce the result ; but the whole phenomenon seems to be mysteriously connected with ozonized oxygen, and is undoubtedly another phase of that obscure subject, allotropism, to which we alluded in a previous lecture. See now how beautifully this attribute of nitrogen has been adapted to the conditions of vegetable life, and made the means by which the plant is furnished with one of the articles of its food. Every discharge of lightning is accompanied by a partial combina- tion of the elements of the atmosphere, and the nitric acid which is thus formed and washed down by the rain-water serves to fertihze the soil and bring the growing corn to maturity. So in like manner, when life is extinct, and the organized forms are resolved into their original elements, the very process of decay causes a similar combination, and thus sweetens the flowers which spring from the grave. But not only does nitrogen combine with oxygen. It unites also with hydrogen, that element which is the very antithesis of oxygen, and forms a most remarkable compound called ammonia. This substance is the very reverse of mtrrc^acid in all its chemical relations, but, like nitric acid, it is a highly active and caustic agent. I need not dwell upon this fact ; for the common smelling-bottle has made every one familiar with this pungent substance. Nitrogen manifests the same indifference towards hydrogen that it does towards oxygen, and the two elements can be made to unite only by indirect processes, which are not well understood. The most important of these is the process of decay. This destructive change in all the higher forms of organized beings is attended with the formation of ammonia, and the same nitrogenized compound is a uniform result of the normal functions of animal life. You will not, therefore, be surprised to learn that traces of ammonia, as of nitric acid, are found in the atmosphere and in all rain-water. Indeed, it is generally supposed that the two are in combination, forming a salt called nitrate of ammonia, but the amount present is, at best, very small. Ammonia is thought by many to be a more important article of vegetable diet than nitric acid ; but our knowledge of agricultural chemistry is very imperfect, and chemists are not agreed on many of the most fundamental points."^ Still, as I have before stated, nitrogen is an essential element of all the higher forms of corporeal vitality, and compounds like those we have been considering are the appointed channels by which it is introduced into the organization of the plant. Had these compounds been allowed to form to any extent in the atmosphere, they would soon have rendered the globe uninhabitable. It was therefore essential that nitro- Since this book was written, it has been stated by several investigators that the chief nitrogen compound in the atmosphere and in rain-water is nitrite of anwionia^ which differs from the nitrate of ain?nonia mentioned above only in containing a smaller proportion of oxygen. Whether the last is also normally present does not yet appear, and to what extent the one or the other may be concerned in the processes of vegetable growth, has not been determined. From one point of view, nitrite of ammonia may be regarded as composed of nitrogen gas and water, and some chemists believe that it is formed by the direct union of these two substances, and that this union is favored by the processes of evaporation, combustion, and decay which are constantly going on in the atmosphere. This theory is certainly supported by many facts, and those who hold it generally believe that nitrite of ammonia is the chief, if not the sole, source from which the plants derive their supply of nitrogen, while others attach only a secondary importance to the recent experiments. If the theory is correct, the foraiation of nitrite of ammonia — the presence of which in surface-water, and in the soil, under certain conditions, is beyond doubt — would be the natural result of the subsequent union of nitrite of ammonia (formed as just described) with the oxygen of the air ; but, as intimated above, the whole subject is still very obscure, and from any experiments yet made we should not be justified in drawing definite conclusions. gen should be endowed with that unexampled inertness which it manifests in its gaseous state. But had not at the same time a power of combination, under certain restricted conditions, been granted, this chemical element would not only have been an isolated phenomenon in nature, an exception to its general laws, but its usefulness would have been restricted to the least remarkable of its functions. Unlike the results of human skill, this creation of Divine wisdom has been adapted to the most varied and apparently incompatible ends ; and while in the atmosphere it is a mere dead weight, it is also the most plastic of the elements, is capable of entering into the most complex relations, and thus serves as the peculiar substratum of all the higher forms of organized being. - The last point I am to illustrate in regard to nitrogen is, perhaps, the most characteristic of its features, and it is one on which its relations in the scheme of organized nature very greatly depend. All the compounds of nitrogen are very unstable, and the slightest force is generally sufficient to overpower the delicate affinities by which the elements are held together, when the nitrogen at once returns to its home in the atmosphere. Although this inert element may be coaxed into combination, it never forms strong compounds. Its affinities, although so varied, are at best very feeble and delicate. It is always a weak timber in a chemical structure, and when this timber breaks, as it certainly will, sooner or later, the whole falls. You will need no further illustration of this fact than to be told that gunpow- 2l8 PRONENESS TO DECAY. der, percussion-powder, and gun-cotton are.all nitrogenized compounds, and oweTKeTr well-known properties to the weak affinities of this element. Nitric acid is only a little more stable than these explosive agents, and ammonia, although one of the most permanent of nitrogenized compounds, is still very easily decomposed. Passing next to organized substances, we find this distinguishing character still more conspicuous. As we have already seen, it is always the nitrogenized compounds which start the decay in vegetable or animal structures ; and thus the great characteristic feature of all organized matter, its proneness to change and decay, nay, even death itself, is clearly foreshadowed in the properties of nitrogen. When the Creator first endowed this element with its feeble affinities, He also passed the doom of all living creatures : ^^ Dust thou art, and unto dust shalt thou return." Here I must leave this division of my subject. It would be highly interesting to study the innumerable phases in which nitrogen manifests itself in the world of living matter; to trace how, under the guidance of that mysterious principle of life, the mpst complex organic compounds are educed from such simple materials as water, carbonic dioxide, ammonia, and nitric acid ; to follow these nitrogenized compounds through their varied history, from the time they are first generated in the plant until they are incorporated into the brain, the muscles, and the bones of man ; to notice at every stage the same instability which so strikingly characterizes all the compounds of this singular element, capable of existing only under the continued influence of the vital principle, and, when that ceases to act, gradually degenerating and falling back into the simple products from which they sprang ; but all such details would be incompatible with the plan of these lectures, and must therefore be reluctantly passed by. If, however, I have been able to place before you in a clear light the main features of this remarkable element,j^its isolated existence in the atmosphere, its unparalleled inertness in the aeriform condition, its power of combination under restricted conditions, the great variety and complexity of its compounds, and, finally, their singular proneness to decomposition and decay ,-\it is all that I could expect. We have seen thatin each of these respects nitrogen has been adapted with exquisite skill to the unique part which it plays in the scheme of the world ; and this element, although outwardly so unattractive and dull, has borne the richest testimony to the wisdom of the Maker. Having now become acquainted with the characteristic features of nitrogen, let us next consider the part which this element plays in that grand circulation of matter in organic nature, which has been already in part described. I have before stated that the plant is a true apparatus of reduction, in whose leaves carbonic dioxide is decomposed hy the solar light. The plant absorbs carbonic dioxide partly through its leaves from the air, and partly through its roots from the soil. The sun's rays, acting upon the green surface of the leaf, decompose in some 220 THE PLANT A PRODUCER. mysterious way the carbonic dioxide, overcoming the intense affinities of its elements, fixing the carbon, and setting free the oxygen, to be restored to the air. From the carbon thus obtained, and from the water, ammonia, and nitric acid which are the other articles of its food, together with a few inorganic salts, the plant constructs its tissues. If in their production carbonic dioxide and water alone take part, there result such substances as woody fibre, starch, gum, and sugar, and of these ninetenths of all vegetable structures consist. If the nitrogen compounds are likewise employed in tfie process, there are formed, besides, suchnitrogenized.products as albumen, caseine, and fibrine. These last names may not be so familiar to you as the first, but you are equally familiar with the substances, and will recognize them at once when told that the white of an egg is nearly pure albumen, that cheese consists almost entirely of caseine, and meat of fibrine. Although these substances are best known to us as animal products, they are likewise found in all those vegetables which are articles of food. Albumen and caseine can readily be extracted from either peas or potatoes, and gluten, the substance which gives tenacity to flour-paste, has essentially the same composition as animal fibrine. The animal, unlike the plant, has not the power of forming the substance of its tissues from inorganic compounds, but it receives them ready formed from the vegetable kingdom. It transmutes the vegetable products into a thousand shapes in order to adapt them to its uses, but its peculiar province THE ANIMAL A CONSUMER. 221 is to assimilate and consume, not to produce. The nitrogenized compounds just referred to are the portion of its food which suppHes the constant waste attending all the vital processes. The non-nitrogenized starch and sugar, although they; form the greater part of our food, are never actually incorporated into the tissues of the body, and, as we have already seen, are^ merely the fuel by which its temP^erature is maintained. The animal may either receive its nitrogenized food directly from the plant, as is the case with all herbivora, or only indirectly^ like the carnivora ; but in either case the origin is the same, and by the process of digestion these, originally at least, vegetable products are assimilated and converted into bones, muscles, or nerves, as the necessities of the animal may require. We find that during this process these substances do not undergo any fundamental change, but merely become parts of more finely organized tissues. We discover in the blood albumen and caseine, having precisely the same composition as that which may be prepared from potatoes, and the substance of the muscle does not differ essentially from the gluten of flourmeal.. Do not, however, suppose that the part played by the animal is less noble than that of the plant. It is really much higher. We must be careful to make a distinction, too frequently overlooked, between the organized structure and the material of which it consists. There is the same difference here as between a house and the bricks of which it is built. It was formerly supposed that organic matter was 222 MATTER AND ORGANISM. formed under peculiar influences, and subject to special laws. But it is now known that animal and vegetable substances obey the same laws of affinity as mineral matter, and the recent progress of chemistry has given us great reason to believe that we may be able one day to prepare all the materials of which plants and animals build their cells. Here, however, chemistry stops and creation begins. The great Architect of nature alone can fashion this dead material into living forms."^ The vegetable kingdom is a great laboratory, in which the sun's rays manufacture from the gases of the atmosphere, and from a few earthy salts of the soil, the different materials which the organic builders employ. There the bricks are made, and from these the animal builds his bones and muscles. He does not make the bricks, but he does what is far more glorious, he builds with them his delicate frame, and as the work of the builder is higher than that of the brick-maker, so in the scale of being is the animal higher than the plant, and the more noble in proportion as its structure is more intricate and elaborate. While the plant is a true apparatus of reduction, the animal is a true apparatus of combustion, in which the substances it has derived from the vegetable are burnt and restored to the atmosphere in the * I do not forget the alleged facts of spontaneous generation ; but even after the very extended investigations of the last ten years, it may still be stated as the general result of the innumerable experiments which have been made, that, in no case has even the lowest type of an organic cell been produced from unorganized matter, unless through the natural processes of growth from a pre-existing germ. ORIGIN OF MUSCULAR POWER. 223 form of carbonic dioxide, water, and ammonia, ready to be again absorbed by the plant and to repass through the phases of organic life. Our bodies are furnaces, — furnaces continually burning, — whose fuel is our flesh, and whose smoke is the breath of our nostrils. Every time I strike a blow a portion of the muscle is consumed, actually burnt up in producing the force. In every muscular effort I make, in every word I utter, in every step I take, a portion of the muscles concerned is burnt, and motion can no more be produced in the animal body without a combustion of its tissues, than it can be generated in a steam-engine without burning fuel under its boiler. As in the steam-engine the burning fuel is the source of its power, so in the animal body the burning muscle is the immediate cause of all its motions. I will to strike a blow, but my will is not the moving power. The power is in the muscle, and in the exertion the muscle is consumed. The muscle, however, does not originate the motion, any more than the fuel originates the motion of the steamengine. The_Riel, we have seen, does not originate heat. It is merely a reservoir of heat, and in burning it merely givesup the heat it once received from the sun. So the muscle is merely a reservoir of force, and in burning it gives out the force it contains. The force it contains it also received from the sun, when its substance was formed by the sun's rays acting upon the leaves of the plants. What a wonderful revelation is this ! Muscular power originates in the sun. We do not create the force ; we do not originate it ; we merely excite it. 224 THE ANIMAL MACHINE. The force which originally came from the sun lies dormant in the muscles until our will calls it into activity. Our bodies are machines, perfect machines it is true, but yet machines. Like all other machines, they merely transmit power, they cannot create it. They very closely resemble a steam-engine. As we must constantly feed the engine with fuel, so we must supply our bodies with food in order to repair the muscle burnt, and we can no more be said to originate that force which manifests itself in our bodies, than the stoker, who shovels the fuel into the grate, can be said to originate the force of the steam-engine. We are not our bodies, although we live in them, and direct their motions. They move by forces which emanate from a source far higher than we, and we stand in the same relation to them in which an engineer does to his machine. Certainly Lavoisier, the great father of modern chemistry, had caught a glimpse of the results which it was left for more modern science to establish, when he wrote : " Organization, sensation, voluntary motion, life, only exist on the surface of the earth, and in places exposed to the light. It might be said, indeed, that the fable of Prometheus was an expression of a philosophical truth, which had not escaped the penetration of the ancients. Without light, nature were without life and without soul ; a beneficent God, in shedding light over creation, strewed the surface of the earth with organization, with sensation, and with thought." power emanates from the great centre of the solar system, let us, while we recognize this startling result of science, remember the no less certain fact of consciousness, — that we are not our bodies, though we live in them, — that this conscious personality is something entirely apart from, and infinitely superior to, these corporeal atoms in which it is temporarily enshrined, surviving as it does all their changes. Let us also keep clearly in view the still more glorious truth, that this machine, with all its infinite capabilities of good and evil, is put entirely at our command ; that not one conscious motion can take place unless we will it ; and that this will of ours can set in action a chain of causes which no space can bound and no time can limit. Let us then well consider how great is the power which has thus been delegated to us, let us duly weigh the awful responsibility it involves, and so act that, when the Master claims his own, we may not be ashamed to render up the account of our stewardship. Moreover, although it is true that these bodies themselves are constantly dissolving into air, that the material atoms w^hich compose them will in a few short weeks all be gone, and that there is nothing but the shadow of our forms which we can call our own, we must also remember that there is a mysterious principle within, constantly renewing and repairing our wasting frames, — a cunning architect superintending a thousand builders who are constantly reconstructing, with materials prepared by vegetation, the bones, the muscles, and the nerves, as fast as they are wasted and consumed; making, 226 THE VITAL PRINCIPLE. in a most mysterious way, beyond all human comprehension, here the fibre of a muscle, there the filament of a nerve, here building up a bone, there uniting a tendon, fashioning each with scrupulous nicety, and fitting each to its place with never-failing skill. But no sooner is the work of the architect done, than another great power comes in to destroy it. The oxygen gas which the blood absorbs in the lungs and carries to the different parts of the body burns up these carefully elaborated tissues, converting them into carbonic dioxide, water, and ammonia, which pass into the atmosphere, from which they originally came. Life is, in fact, a constant struggle between the builders and the destroying element of the air; and when its short term is ended, and the builders cease because they are wearied and few, then '' the dust returns to the earth as it was, and the spirit returns unto God who gave it." But let us not sorrow as those who have no hope ; " for we know that if our earthly house of this tabernacle were dissolved, we have a building of God, an house not made with hands, eternal in the heavens." And cannot He who hath clothed us with our earthly house provide for us a better and more enduring mansion? and are not all these wonderful changes in our present bodies a foreshadowing of the final consummation, when our earnest desire '^ to be clothed upon" shall be satisfied, and " mortality shall be swallowed up of life " ? Such is a very imperfect sketch of that great cycle of changes, of which all organic nature is merely a passing phase. Let us review for a moment its main THE ORGANIC CYCLE. 22y features. When the foundations of the globe were laid, there were collected in the atmosphere all the essential elements of organized beings. From this inexhaustible storehouse the plant absorbs water, carbonic dioxide, and ammonia, which were placed there for its use, and which have been made to serve as its nourishment and food. It is the special office of the plants to elaborate from these few mineral substances, and a small amount of earthysalts, all the materials of organized beings. The animal receives these crude materials already prepared, and builds with them its various tissues; but no sooner are the cell-walls finished, and the structure ready to discharge its vital functions, than it is consumed by almost the very act which gave it life. The carbonic dioxide, water, and ammonia are restored to the atmosphere, and the cycle is complete. Of this Divine economy the sun's rays are the great moving cause, and it is their mysterious power which is constantly reappearing in all the varied phases of organic life. And not in these alone ; for, as we have seen, this same gentle influence keeps in motion the aerial currents which blow our ships across the ocean. It raises the water which turns the wheels of our factories. It drives the locomotive over the iron road, and impels the steamer through the waves. It roars at the cannon's mouth, and charges the grander artillery of the skies. There is no motion on the globe which cannot be traced directly or indirectly to the sun, and were his rays to lose their mysterious power, all nature would become silent, motionless, and dead. 228 THE FIRST CAUSE. But in thus tracing to the sun all these varied phenomena, let us not forget that we have not yet found the great First Cause. The problem is not yet solved ; the profoundest truth has yet to be told. This mysterious force, which the sun pours in ceaseless floods upon the earth, — whence comes it ? You have already answered the question. The answer is on your lips. I have but to re-echo it, and how can I better do this than in the words of that blind poet to whom misfortune had revealed the true meaning of light : ' Hail, holy Light ! offspring of Heaven first born ; Or of the Eternal co-eternal beam May I express thee unblamed ? since God is light, And never but in unapproached light Dwelt from eternity, dv^elt then in thee, Bright effluence of bright essence increate." ARGUMENT FROM SPECIAL ADAPTATIONS. I HAVE endeavored thus far in this course of lectures to present a few of the prominent illustrations of the attributes of God, which have been discovered in the adaptations of the atmosphere to the conditions of organic life on the earth. We have read together one brief chapter of that evidence of design with which the book of nature is filled, and I cannot but trust that we have gained from our study nobler conceptions and more enlarged views of the wisdom, power, and goodness of our Heavenly Father. Every one who accepts the Bible as a divine revelation will rejoice to find how beautifully and how entirely the facts of science confirm its great fundamental truths. But have not these evidences of nature a greater value even than this ? Do they not prove, independently of all revelation, the existence of a wise and omnipotent First Cause, at least so far as there is any moral certainty in the world ? I am persuaded that they do, and I believe that they furnish the only logical ground on which a system of revealed religion can be based. In my introductory lecture I stated that I preferred to 230 CHARACTER OF THE ARGUMENT. discuss the adaptations of nature as illustrations of the attributes of God, rather than as absolute proofs of His being; but now that we have surveyed the ground, let us consider whether they are not really moral proofs, with all the certainty that any proof not strictly a mathematical demonstration can give. The argument from adaptation is one which addresses itself to every human being. It is suited to every intellect, and comes home to every man's experience. It is based on a principle of the human mind, — whether the result of experience or of intuition we need not inquire, — which compels it to infer design when it sees adaptation. Who doubts that the flint arrow-heads and stone implements found in New England, rough and misshapen as they are, were made by men ? To question the universal belief would be regarded as little short of insanity. Why then not apply the same common sense to the interpretation of nature ? The unlettered do, and believe, in their simple faith, that the feathered songster and the delicate flower were made by their Heavenly Father's hand. It is only those of us whose minds have been unsettled by the subtilties of logic who doubt, and, if we could analyze our doubts, I think they would be found, in most cases, to arise from a vague fear that, since nature stands on a level so much above man's experience, the ordinary principles of reasoning may possibly not apply, and we may be misled by apparent analogies. But why this fear? There is no essential difference between the adaptations found in nature and the adaptations made by men. Both employ means to attain some important result, and in many cases they secure the end by precisely the same means. The telescope and microscope are but reproductions of the eye, and imitate in all their essential features this beautiful optical apparatus of nature."^ It is true that the adaptations of nature are vastly superior to the results of human skill, and it is also true that their origin is beyond our personal experience. We have seen the process of making a watch and the process of making a telescope. We know how the principles of both were discovered, and the whole subject lies within the range of our experience ; but no man ever made or ever can make an eye, and the whole process of its growth and development is utterly beyond the range even of man's conception. All this is true ; but if you reflect a moment, you will find that this is just what is to be expected, seeing that God is the Creator and we are His creatures, and so far from weakening, this very characteristic greatly strengthens the evidence. Moreover, it must be remembered that, if the design is of an infinitely The power which the eye possesses of adaptation to near and distant objects, combining the uses of the microscope and the telescope, and the capacity of self-adjustment, preserving always a perfect achromatism and freedom from spherical aberration, have never been reached in nearly the same degree by art. Moreover, in the eye this perfection is attained with a focal length of only half an inch, which vastly increases the difficulty. It is also a fact worthy of notice, that the improvements in optical instruments have preceded rather than followed the discoveries of physiologists, thus serving to explain the functions of the eye ; and inventions like that of achromatic lenses, to which men have been led by theoretical study, have been found to be anticipated in nature. 232 THE ARGUMENT CUMULATIVE. higher order, the evidence of the design is infinitely more ample. A rude, misshapen image is a convincing evidence of human intelligence ; but all nature, with its numberless adaptations — from the properties of the crude elements up to the wonderful structure of the human frame — is given us as evidence of the wisdom of God. The argument from the adaptations of nature is of the kind we call cumulative. Its force depends on the concurrence of many and varied examples. It is not based on one isolated case of adaptation, or even on a thousand ; but there is a host of conditions, which no man can number, each adjusted to each, and all bound together in one harmonious whole. Consider only the examples we have discovered in the very narrow field to which we have limited our study. How numberless are the conditions on which the harmonious working of the varied functions of the atmosphere depends ! In the first place, there is the expansive tendency of the air, sustained by the solar heat, and restrained by the force of gravity, by which alone it is held to the surface of the globe. Then there is the density, exactly adjusted to the human organism, and depending on the measures and weights of the solar system. Next there are all the delicate relations to light, heat, and electricity. Passing to the separate constituents of the atmosphere, there is oxygen, with its three distinct modifications, endowed with fiery afifinities, and yet so carefully guarded as to be a beneficent servant of man, intrusted with most varied and seemingly incompatible functions, and discharg- FACTS REVIEWED. 233 ing each with equal fideHty and precision ; next, there is water, nourishing all nature with its dews and rains, tempering the polar climates with the latent warmth of its genial currents, and protecting with its great frost-blanket the delicate plants from the winter's cold, — exceptional in all its qualities, and each adapted to some beneficent end ; then comes carbonic dioxide, concealing in its transparent folds the solid framework of all organized beings, and the source of those priceless beds of coal, with their inexhaustible stores of heat and force ; and lastly, but not least in interest or importance, there is nitrogen, so remarkably inert, and yet endowed with such varied affinities, forming such numberless compounds, and imparting to all such singular instability. As we thus hastily review the ground we have surveyed together, you will recall the numerous adaptations we discovered while studying the wonderful cycles of change in which all these substances conspire, wheel revolving within wheel, and yet all moving with such delicacy and beauty of adjustment that no jar is felt through all this complicated mechanism, and not the slightest derangement occurs in any of its ten thousand parts. Now the argument for design unfolded in this brief chapter of the book of nature comes home to us with the cumulative weight of all this testimony. Perhaps plausible objections might be urged against individual examples of adaptation which have been advanced ; but any one who questions the general fact must be prepared to disprove all. Were there but a single instance of adaptation, or only two or three, the sceptic might urge with a show of reason that this was the result of accident, — arose from the ' fortuitous concourse of atoms " ; but the examples of adaptations which we have discovered merely in the atmosphere, all interlacing with each other, and all working together in the general scheme, are by themselves alone so great a number that, if we take no higher ground than the mathematical theory of probabilities, the chances against the supposition that this system, even as we know it, was the result of accident, are almost infinite, and can be expressed numerically only when the sands on the sea-shore are counted. If such, then, is the weight of the evidence which the atmosphere gives, what must be the force of the argument in which all nature gives its united testimony? Truly, the number of atoms in the universe is not sufficiently large to express the probabilities against this forlorn hope of atheism ! But, my friends, the sceptic should be heard, and, having presented our side, let us listen to what he has to say in reply. The whole argument from special adaptations may be summed up in a few words. Within the sphere of human experience, adaptation proves the existence of an intelligence adequate to the conception and execution of the design. We find in nature adaptations similar to the results of human intelligence, only of an infinitely higher order, and hence by analogy we conclude that these must have issued from an infinitely wise and omnipotent Designer. The argument assumes the reality of the human intelligence as consciously BURDEN OF PROOF. 235 a power and an originator within its own sphere, and reasons from this to a similar conscious intelhgence in the Author of nature. The argument assumes, also, the truthfulness of the human faculties as a source of knowledge, without which it is of course useless to reason at all. Now the adaptions of nature are facts which everyone must admit, the sceptic among the rest. More- ' over, he must also admit that the conclusion which we have drawn from these premises is the all but universal conclusion of mankind. Plutarch, writing eighteen centuries ago, without the light of the Christian revelation, bears this remarkable testimony to the universality of the religious idea: If you go through the world, you may find cities without walls, without letters, without rulers, without dwellings, without wealth, without money, without theatres and manly sports ; but there was never yet seen, nor shall be seen, by man a single city without temples and gods, or without prayers, oaths, prophecies, and sacrifices, used to obtain blessings and benefits, or to avert curses and calamities. Nay, I am of opinion that a city might be sooner built without any ground beneath it, than a commonwealth could be constituted altogether destitute of belief in the gods, or, being constituted, could be preserved.' * The discoveries of modern travellers ■^ Evftoi'^ 6^ ay kitiwv TtoXei^ dretxidrov^f dypaj.i).idTov<^, d/JadiXevTov<5, domovS, dxf^r/udrovS, vof.n6uaTo<i uij dsojuera'5, dTtei'fjovS OedrpGov xai yvjuvadiGDV dvtspov Ss TtoXsaoi nai dOeov, jtii) XP^M^'^V'^ tvxctl?, juj^de opHoi<^, jtcf^de tuayreiaii, jLir/de Ovdi'aiS kii^ dya^oi^, juf/d^ dnorpoitali HaKcoy, ovdei<5 have not more fully confirmed the general truth of Plutarch's statement, than the experiments of modern socialists have proved the soundness of his opinion. No savage tribe has yet been found on which a belief in a higher power has not at least glimmered, and no community which has attempted to ignore religion has lasted a century. The sceptic, then, if he rejects our conclusion, is bound to prove that the natural inference of man is based in error. If he sets aside the general rule of faith, and refuses assent to the universal creed, — " Quod semper, quod ubique, quod ab omnibus creditum est,'"^ — he must explain, whatever theory he may adopt, how it comes to pass that all mankind have been duped, and all nature has issued in a lie. The burden of proof is with him, and how does he meet it ? Generally in one of two ways. In the first place, he attacks the validity of the conclusion on purely speculative grounds, saying that adaptation is no longer an evidence of design when applied to subjects beyond the range of all human experience. He may urge, and urge with reason, that in nature we have no sure criterion by which we can distinguish between means and ends, between what is cause and what is effect. He may support this position by questioning, with Hume, the competency of the human faculties as a source Idriv ov8^ edrax ysyovcbi Bearjj'i' dXXd 7t6Xi<^ ar JlLoi 8okeX l^idXXor lddq)OV^ X^P^^f V TtoXirela TTJi Ttepi OecSv do^r^S vq)aipEf)8i6r/<^ 7tarrd7ta6i, 6vdra6ir XafSelv, rf Xa/Jovda rr/prjdai, Plutarch, Upo? KoXg6t?/v, xxxi. of knowledge, or, like Comte, he may deny all knowledge of final causes, and maintain that there is no \ evidence of anything behind the external phenomena of nature; but whatever form the scepticism may assume, the conclusion is the same, and the argument for design is ruled out as invalid. With regard to this position I have only a few words to say. Design in nature, I admit, cannot be demonstrated ; for the truths of natural religion cannot be evolved from a mathematical formula. The argument is based on analogy, and although the analogies are so close and so broad that, to my mind, they amount to moral proofs, and the conclusion appears as certain as any theorem of geometry, still I admit that the evidence is probable, and not demonstrative. But as a student of physical science it is not my business to defend the credibility of the human faculties, or to discuss the doctrine of causation. The task belongs to the metaphysicians, and, as I stated in my first lecture, I shall not encroach on their peculiar province. Nor do I think it important to dwell on the value of analogical reasoning. Modern writers have not been able to add much to Bishop Butler's masterly discussion of the subject, and every man, however sceptical he may be in his speculative opinions, must admit, with the author of " The Analogy," that " probability is the very guide of life." One consideration, however, may be of value in answering objections, namely, that since the difficulties which are found in natural theology reappear with equal strength in all departments of knowledge, no objections can be reason- 238 PROVINCE OF DEMONSTRATION. ably urged against the methods of the former, which do not apply equally well to our most familiar processes of thought. It may be fairly presumed that such objections are more apparent than real, and that they indicate not the inconsequence of our logic, but only the necessary limitations of our faculties. Now analogy is not only the guide of common life, but it is also the basis on which physical science chiefly rests ; and if this method of reasoning be disallowed, all the results of science beyond those of mere observation and demonstration must fall with it. It is frequently said, that scientific truth can be demonstrated, but religious truth must be accepted on faith ; and in part this is true ; but the statement is one of those loose sayings whose partial truth only renders the latent error more dangerous. No word is more frequently misused than "demonstration." Technically, this term only applies to that form of absolute proof with which we deal in geometry or pure logic ; but, popularly, a principle is said to be demonstrated when all that can be claimed for it is a high degree of moral certainty. In this double use of the term the error of the above statement lies, for it is made in one sense, and — frequently at least — understood in the other. Truth wholly new is never reached by the methods of demonstration ; for demonstration cannot yield what is not already implied in the premises with which it starts. The truths of geometry and mechanics may be demonstrated ; but then they are virtually contained in the axioms and definitions on which these sciences rest. All scientific generaliza- ANALOGY THE CHIEF GUIDE. 239 tion is based on analogy ; and moreover, a great mass of the scientific truth which lies within the range of direct observation we owe to the same principle ; for even here analogy directed the student to what he subsequently observed. Indeed, the great inspiring and directing power in the minds of the successful investigators of nature is the force of analogy. It is this which constantly leads them to pronounce conclusions unsound, although apparently sustained by experiment, and to accept others which are seemingly at variance with facts. It is this which leads them through long and laborious investigations to establish principles which they believe to be true, and sustains them in their efforts through successive failures to ultimate success. As indefinite and uncertain as the analogies of nature frequently seem to be, as unsatisfactory as they may appear to the great mass of mankind, and as impossible as it is to make them intelligible except to those already versed in scientific inquiries, yet the history of science shows that, when based on an extended knowledge and a mature experience, they very seldom lead astray. The method of scientific discovery is frequently misunderstood, and the philosophy of Bacon, however important in correcting old abuses, has done not a little towards creating the misapprehension. Many persons seem to think that the author of the Novum Organum gave to man a rule, by which, with the aid of a sort of mechanical logic called induction, the laws of nature may be discovered very much as a last is turned out by a lathe. Yet 240 METHOD OF SCIENTIFIC DISCOVERY. nothing could be further from the truth. So far as the observation of phenomena is concerned, — which must always be the occupation of the great mass of scientific men, — the methods are as mechanical as those of other learned professions, requiring chiefly a quick eye, a delicate touch, a ready perception, and, most of all, a clear head capable of discriminating between the accidentals and the essentials, which are always singularly blended in natural phenomena. But the great generalizations, which form the framework of knowledge, are not reached by rule ; nor, as a general thing, are they in their inception of slow growth. On the contrary, they usually come like intuitions to the mind, with the rapidity of the lightning's flash, and it is frequently possible to mark the day and the hour when the revelation was made. But such revelations of scientific truth are vouchsafed only to those highly favored minds which through long study and patient investigation have been brought into perfect sympathy with the harmonies of nature ; and if we analyze the conditions of the mental process, we shall find that these great discoveries are really the result of analogical reasoning. But although the conception is thus sudden, the verification of the truth is frequently long and laborious. Great discoveries are not achieved in an hour or a day. Nature has so concealed her truths, and surrounded them by so many adventitious circumstances, that they can be disclosed to the world only after long and careful study. First comes the conception, afterwards the toilsome investigation by which it is proved that the facts of nature accord with the generalization. The investigation may lead to a great modification of the original idea, or may show that it must be wholly abandoned, and meanwhile another may have taken its place, to go through the same scrutiny in its turn ; but still the conception which proves to be the law of nature is the real discovery. This, as we have seen, is the result of analogy, and most clearly vindicates the relationship of the mind of man to the Intelligence whence issued the universe. Every great scientific generalization will illustrate more or less clearly the principles here stated. It is true that many minds frequently concur in developing one grand idea, and the evolution may occupy so long an interval of time that the new truth appears to be the growth of an age, rather than the gift of any one man. Yet it is possible in almost every case to trace the successive steps of the discovery. This is especially true of the law of gravitation. Whether the first idea was suggested to Newton by the fall of an apple, it is not important to inquire; but the popular anecdote illustrates the nature of the original thought, which was undoubtedly sudden and intuitive, although, as Newton has himself expressly stated, it was the result of analogical reasoning. The conception once formed, the work of verification was long and laborious, and the results were at first so unsatisfactory that Newton at one time abandoned his theory altogether, as unsupported by observation. It was not, indeed, until a new arc of the meridian had been measured by 242 METHOD OF NATURAL RELIGION. Picard in France — several years after the first conception— that the facts were found to agree even approximately with the theory, and astronomers have been occupied ever since in verifying the grand thought. The same general facts reappear in the case of the wave-theory of light, first conceived by Huyghens and subsequently verified by the successive discoveries of Malus, Fresnel, and Young ; and we may lay it down as an almost universal principle, that scientific truth is discovered through analogy and verified by comparison with the facts of nature. If now you will turn to the great central truth of natural religion, you will find that it has as ^ood credentials as the best established laws of science. We have first the conception, — not only the conception of a few highly gifted minds, but the universal conception of mankind. We find afterwards this conception verified, — not only in the history of the race, but also in the experience of each individual man, and moreover, the conception is apparently intuitive in every mind. Even if the sceptic denies the reality of both special and general providence, he must admit that, as the most universal rule, both history and experience have only served to confirm and strengthen the religious idea. We now return to the remark above quoted, better able both to appreciate the truth it contains and to unmask the fallacy it conceals. A large part of the results of science may be demonstrated, but only such truths as are already contained in the premises on which the demonstration rests are capable of this absolute proof ; and these are in all cases PROVINCE OF FAITH. 243 reached by the human intelligence working on its own definitions and processes of thought, and this, too, even when the theoretical truth is afterwards found realized in nature. The highest forms of scientific truth are not capable of demonstration, and rest only on probable evidence, although the probability in their favor may be so great as to beget the highest degree of moral certainty. In like manner, a great part of the truths of religion must be accepted on faith ; but then the evidence in favor of the great fundamental truth of natural religion is as strong as the evidence for any theory of science, and the certainty is as great. Moreover, faith is not peculiar to religion. All our knowledge not the resuir^STp^Fsonal observation and investigation is held on faith, that is, on trust in other men, and absolutely all knowledge is held on trust in the authority of our own mental powers. Much of the knowledge which we hold without question, it is utterly beyond the capacity of our own intellects to verify, and moreover, no one doubts the existence of truths which now lie beyond the scope of the most gifted genius, but which hereafter may be attained by man. The scientific truths which it is not essential for us to know are left in the dark on purpose to stimulate study, and thus to educate the human race. Religious truths, on the other hand, it is essential for us to know, and, since they in like manner transcend our present powers, they have been specially revealed. We are called upon to accept them on sufficient evidence, and this is all that is meant by faith. Faith, then, is as truly a ground of belief 244 REPLY TO THE SCEPTIC. in science and in common life as it is in religion, and it occupies a more important place in religion only because religious truth is itself so important, and so greatly transcends, in its essence, our limited human faculties. Our reply, then, to the first position of the sceptic is this. Your objections apply as well to all knowledge as they do to religious truth, and, if you are consistent with yourself, you must reject the evidences of science as well as the evidences of religion."^ As we are not prepared to go this length, we shall with equal consistency hold to both. It is but justice to state that Hume, the most philosophical of the sceptics, pushed his speculations to their necessary consequences, and denied the existence of matter and spirit alike. But although from its very boldness difficult to refute, this form of scepticism is by no means the most dangerous; for in the present age of the world a system of philosophy is not likely to gain many adherents which, in the first article of its creed, utterly shocks all human self-conceit by declaring that man neither knows nor can know anything with certainty. In the second place, the sceptic attacks the argument for design by setting up a theory of his own to explain the origin of the universe. He tacitly admits that the burden of proof is with him, and that, if he rejects the popular belief, he is bound to show how this cosmos might have been issued with- ABSOLUTE MATERIALISM. 245 out intelligence and without a God. This he attempts to do, and the result is nearly as many theories as there have been strong scientific intellects in the world united with unbelieving hearts.' To refute each of these theories in detail would be a labor like that of Hercules in slaying the Lernaean Hydra ; for until Almighty Power shall sear the foul sore from which the whole brood proceeds, their unholy heads will start up more rapidly than they can be cut down. The most daring theories of this kind are those of the German materialists of the present day. As much as they may differ among themselves in regard to details, the boldest of these speculators agree in maintaining that absolutely nothing exists, or ever has existed, except matter and motion ; that matter in its essence is uncreated and eternal ; that motion is self-sustained ; that mind is only a mode of motion, and that all the phenomena both of matter and of mind are the working out of an inexorable necessity. Hence they conclude that religion is a fable, and immortality a dream. Here is atheism. This is the natural fruit of materialism ; and we are glad that it has ripened, that men may see how disgusting and revolting it is, and how corrupt the tree must be which can bear such fruit. We are glad that men should know what must be the result of all their vain speculation and the seeking after false gods. The theory is perfectly consistent with itself, and an absolute necessity if nature be divorced from its Creator ; for all philosophy has proved that either the the- ory of the Christian, or this theory of the materiahst, with all its enormity, must be true. There is no half-way halting-place between. This course of lectures has been a continued protest against the materialist's interpretation of nature, and I have not another word to add ; for if a man wishes to believe that his purest loves and his holiest affections are only motions of brain-particles, nothing that can be said would have the slightest weight. If he has not already the refutation in his own consciousness of being, human power cannot aid him ; no philosophy can extricate him from the slough. ' Ephraim is joined to idols ; let him alone." It is seldom, however, that materialism shows its revolting features among us. It is too cunning and too cautious. It always appears disguised, and is for this reason far more seductive. It presents the attraction of great learning and of great apparent profundity, entangling many in its meshes before they are aware of their danger. It does not deny the reality of the human intellect, but, on the contrary, takes pride in its authority and power. It even admits the evidence of design, but at the same time insidiously undermines all religious belief ; not so much, however, by what it declares, as by what it leaves to be inferred ; not so much by the doctrines it inculcates, as by the spirit it keeps alive and fosters. In this refined form, materialism is by far the most prevalent phase of the unbelief of our time, and it is difficult to meet chiefly on account of its very vagueness and simulation. It lives almost entirely in the ever-changing theories and specula- DEVELOPMENT THEORIES. 247 tions of science, which it utterly misinterprets and misapplies, forgetting that they are merely provisional expedients, which the next wave of advancing knowledge may wash away. Development is the pet word of its philosophy, and it constantly aims to show how the whole scheme of nature, with all its adaptations, might have been evolved through the concurrent action of various unintelligent causes alone. As it attacks the argument for design on scientific grounds, it becomes the duty of the student of nature to expose its errors. It is, however, a most Protean antagonist, and no sooner is it defeated in one form than it reappears in another. Every new development theory in any department of science furnishes it with fresh food. For a long time the famous nebular hypothesis, broached in Laplace's Systhne du Monde, supplied it with abundant nourishment ; and within the last twenty years it has taken a fresh start, and grown most vigorously, on Mr. Darwin's very ingenious book entitled The Origin of Species, But these are only two examples of a large number of similar works, which, being less able and less original, have had their day and been forgotten. The danger of these works lies not so much in what they actually contain, as in their general tendency ; not so much in the theories of their authors, as in the wrong conclusions which will inevitably be drawn from them, and to which in many cases they logically lead. Darwin, for example, professes to show that all the living forms of plants and animals, man included, have been, during the geological ages, 248 DUTY OF SCIENTIFIC TEACHERS. slowly developed from a few germs, or possibly from only one, by the action of a principle which he calls the ' law of natural selection," and he sustains the hypothesis by a most formidable array of experiments and facts. Such a theory as this, ingenious if not true, professing to explain one of the greatest mysteries, and presented in a fascinating style, finds converts everywhere, and this, too, on grounds entirely independent of its scientific merit. That very same noble aspiration which leads men to imperil even life itself in investigating the secrets of nature, makes them also ready to lend a willing ear to any theory which professes to explain the mystery of creation. Hence the reason why works like the Vestiges of Creation^ and those just mentioned, captivate and injure so many. If they merely stimulated curiosity, and led to study, no one could object to their influence, however erroneous he might think their philosophy. But, unfortunately, most readers, of whom it is no disparagement to say that they are not in a condition to weigh the evidence, accept the theory without examination, and, if sceptically inclined, their whole belief in an overruling Providence is shaken to its base. It is in vain to urge that these theories may be consistent with a pure faith ; for as long as they are not so regarded by the popular mind, — which invariably appeals to them as proofs of materialism, — the evil which they cause is not remedied. It may be said, and said with some justice, that a writer cannot be blamed for the abuse of his theory ; but it must be admitted that the abuse is a great evil, and an DESIGN NOT INVALIDATED. 249 author, if he be a rehgious man, is bound to guard against it by every means in his power. We should be very slow to charge any man with infidelity, for we know how often the human mind, in its eccentricities and inconsistencies, has united a true faith to the most sceptical and subversive speculations. But we do say, that the least a Christian philosopher can do for his faith is to give such a tone and spirit to his work as to render misinterpretation impossible; and if he neglects to do this, he has no right to complain if his own opinions are misjudged. I shall not attempt to discuss the intrinsic value of the various theories of development, but leaving this task to those who are competent judges, let us inquire what bearing they have on the evidence of design. I answer, absolutely none. Assuming that Mr. Darwin could establish his peculiar theory in all its generality, — and I have no doubt that it has a large element of truth, — it would not impair the evidence of design in the slightest degree, and the same is true of any development theory whatsoever, short of absolute materialism. Those persons who imagine that they overthrow natural religion, fall into a capital error. It requires manifestly the same infinite intelligence to creaTte a universe by a process of development as by a single creative fiat. Your belief that the beautiful piece of mechanism standing on your mantel-shelf was made by an intelligent man, would not be impaired if you were told that the artist was employed several years in its construction. The evidence of design in the clock is in its beautifully adjusted mechanism. The evidence of design 250 A LOGICAL THEFT. in nature is in the wonderful adaptation of its parts. We can easily go back in the geological records to the time when the present order of nature did not exist, and the fact that the innumerable forms of organic life, with the adaptations of currents, soil, and climate essential to their being, have been developed out of the conditions which existed on the globe during the coal epoch, is no less an evidence of design than the fact that the clock was developed out of the crude iron and brass used in its construction. "We lament," says Dr. Martineau,"^ "to see the question between a sudden and a gradual genesis of organic types discussed on both sides — not, indeed, by the principals in the dispute, but by secondary advocates — too much as if it were a question between God and no God. In not a few of the progressionists the weak illusion is unmistakable, that with time enough you may get everything out of next to nothing. Grant us, they seem to say, any tiniest granule of power, so close upon zero that it is not worth begrudging; allow it some trifling tendency to infinitesimal increment ; and we will show you how this little stock became the cosmos without ever taking a step worth thinking of, much less constituting a case for design. The argument is a mere appeal to an incompetency in the human imagination, in virtue of which magnitudes evading conception are treated as out of existence, and an aggregate of inappreciable increments is simultane- TOPSYS ANSWER. 251 ously equated in its cause to nothing, in its effect to the whole of things. You manifestly want the same causality, whether concentrated on a moment or distributed through incalculable ages, only, in drawing upon it, a logical theft is more easily committed piecemeal than wholesale. Surely it is a mean device for a philosopher thus to crib causation by hairbreadths, to put it out at compound interest through all time, and then disown the debt ; and it is in vain, after all ; for dilute the intensity and change the form as you will of the Power that has issued the universe, it remains, except to your subjective illusion, nothing less than infinite, and nothing lower than divine.' The genesis of nature has been unquestionably a process of development. But let us not be frightened by words. Development is only another name for growth, and it obviously brings us no nearer to the final cause of a given product to say that it has grown. Topsy in answering her catechist's " Do you know who made you ? '* with " Nobody as I knows on — I spect I growed," was fully as wise and far more humble-minded than those philosophers who attempt to cover up the same answer under high-sounding technical phraseology. Growth is the order of nature, but even in its simplest phases it is as mysterious a phenomenon to-day as it was when the mind of man was first conscious of the fact. That of two minute eggs, in which no anatomist can discover any structural difference, the one should in a few short years develop an intelligence like Newton's, while the other soon ends in a Guinea-pig, is certainly as great 252 GENESIS OF SPECIES. a mystery as that in the course of unnumbered ages monkeys by insensible gradations should grow into men. The growth of each man from a microscopic germ is not understood one whit more fully than the genesis of a species, and the only difference is that while in the first case we are familiar with all the stages of the growth, in the last case we know nothing with certainty except the final result. Surely no one really imagines that the first man came " full armed, like Minerva from the brain of Jove.'* There must have been growth, and how utterly immaterial it is to our present discussion at what point the growth began. Moreover, how evident it is that the growth of a species is as legitimate an object of scientific investigation as the growth of an individual; and further, that if we were as familiar with the successive stages in the growth of a species as we are with those in the growth of each individual man, we should be just as far from a knowledge of the efficient causes in the first case as, with all our careful observation and study, we now are in the last case. But although a knowledge of the efficient causes may in either case be beyond the reach of positive science, yet we have reason to expect that further investigation will lead to the same kind of knowledge in regard to the growth of a species that we now have in regard to the growth of each individual animal or plant. Again, as we well know, growth in nature is very greatly influenced by secondary causes of various kinds, such, for example, as soil and climate ; and as with the growth of the individual, so, undoubtedly, with the growth of the species. Moreover, no one can doubt the potency of the causes which have been so acutely studied by Mr. Darwin. It is the business of science to study these secondary causes, and the nature and extent of their influence are questions of fact to be decided by scientific investigation, and by that alone. The action of these secondary causes, however, is obviously irregular, producing retrogression quite as frequently as progression, and causing those fluctuations which are so characteristic of the growth of nature ; but who can fail to see that during the geological ages there has been a great advance, and the present • complex result, which we call nature, with all its intricate adjustments and relations, can be no 'more rationally ascribed to the causes which have produced variations of details, however great, than can the mechanism of a clock be referred to the circumstances which in different localities have often determined large and important changes in the materials or plan of its construction. I repeat, therefore, no development theory can impair the evidence of design, for that evidence is based on facts wholly independent of any theory of cosmogony, and to which all theories must conform. If they do not, they will inevitably fall. The difficulty, to my mind, in Mr. Darwin's particular theory, is not in its development feature, nor in its principle of " natural selection " as a proximate cause of variation in species, but in the at least tacit assumption made by so many of its advocates that this principle is the one and only efficient cause of the 254 THE FINAL CRITERION. resulting adaptations In nature. As a temporarymode of correlating facts, and as a working hypothesis which has pointed out fruitful lines of investigation, the theory of Mr. Darwin must be regarded as one of the most important contributions to modern science; but a naturalist must ignore the whole history of physical science who would claim that this theory was more than a very partial truth, and unless it can be shown that it is consistent with the action of an intelligent first cause, it will soon be forgotten like those that have gone before it. This is the criterion by which all such theories are finally judged after the excitement of the controversy by which they were heralded has passed, and after the common sense of mankind has settled down upon its sober second thought. Let us insist that all theories of cosmogony shall be judged on their own merits as scientific theories, but let us also insist that they shall be kept within their own sphere, and not allowed to have a voice in questions of religious faith, on which they have absolutely no bearing. That they have an injurious influence while they last, is frequently more the fault of the secondaryadvocates than of the principals in the dispute, and we must not expect to cure the evil by indiscriminate censure or by social excommunication. So long as man thinks, he will speculate ; and I rejoice that neither political nor ecclesiastical tyranny can touch this prerogative of free thought. The true remedy consists in exposing the fallacy of the shallow philosophy which is so ready to bring forward these crude speculations as proofs of materialism, and also views of nature and its laws. To this subject I shall return in the next chapter. But so far as the argument for design is concerned, all these considerations are unnecessary. The evidence is so ample, that we can afford to waive all that part of it which has been called in question by the progressionists, without weakening in the slightest degree the force of the argument. Before the first organic cell could exist, and before Mr. Darwin's principle of natural selection could begin that work of unnumbered ages which was to end in developing a perfect man, nay, even before the solid globe itself could be condensed from Laplace's nebula, the chemical elements must have been created, and endowed with those properties by which alone the existence of that cell is rendered possible. But although, for the sake of argument, we might yield to the progressionists all those examples of adaptation which they claim to explain by their theories, such a concession is really of no value. The parts of nature, as we have seen, are so intimately linked together that, if there be design anywhere, there is design everywhere ; and as the structure of the human body was prefigured by the earliest vertebrate forms buried in the geological strata, so, and as unquestionably, the whole scheme of organic life was prefigured in the gases composing the atmosphere. If, therefore, I have proved that there is evidence of design in the constitution of the atmosphere, I have also proved that the whole scheme of nature is 2S6 HONEST DOUBTS. the result of Divine Intelligence, and that the great argument of natural theology rests on a basis which no present theories'^ of development can touch. To show that there is evidence of design in these stones of nature's edifice has been my chief object in this book. It has been my constant aim to set forth in a clear light the startling fact that the footprints of the Creator are nowhere more plainly visible than on that very matter which the materialists so vainly worship, and if I have thus been able to remove doubts from the mind of any honest seeker after God, I shall feel that my labor has not been lost. But however earnest the purpose or sincere the convictions, the spectres of our doubts will sometimes return, and hover around these evidences of our faith. Treat them not lightly either in yourself or in those you love. Respect all honest doubts ; for it is the noblest natures which feel them and suffer most. His must be a dull heart which is not sometimes appalled by the mystery of our being. Remember, however, that these doubts are from within, not from without. They are the offspring of your fears, and not of your science. The evidence is ample. It is more faith that you need. Fight, then, these spectres of your mind as the enemies of your peace, not with doubtful disputations, but * We of course refer only to such theories and speculations as are based on observed facts ; for no others are worthy of serious consideration. Science has not as yet gone one step behind the chemical elements, and until it has, no speculations in regard to a primordial condition of matter can have any bearing on our subject. ARGUMENT FROM GENERAL PLAN. It has been my object in the previous chapters of this work to develop before you the great argument of Natural Theology as it is presented by the atmosphere. I have endeavored to show that there is abundant evidence of design, even in the properties of the chemical elements, and hence that the argument rests upon a basis which no present theories of development can shake. Having dwelt upon the argument from special adaptations at as great length as my plan will permit, I wish in this chapter to present another class of evidences of the Divine attributes, which, although less conspicuous, may be even more impressive to some minds than those we have studied. The indications of an Infinite Intelligence are not only to be found in the adaptations of nature, but they also appear in the grand laws by which the whole material universe is directed. I am well aware that the laws of nature, so far from being regarded as evidences of the existence of a beneficent God, are felt by many minds to be actual hinderances to their faith. They are thought to give to the whole scheme of nature a mechanical DEFINITION OF PHYSICAL LAWS. 259 aspect, and to be inconsistent with belief in a superintending Providence. I also know that there are many scientific men who regard the laws of nature as the manifestation of blind physical forces, and who recognize a Providence, if at all, only in the very few recorded instances where the normal action of these forces has been averted by a special miraculous interposition. But even admitting this philosophy, still I think it will appear that these laws bear so conspicuously the marks of Intelligence, and are so analogous to the results of human thought, that we cannot resist the conclusion that they were originally, at least, ordained by an intelligent Creator, or, in other words, that the laws of nature are the thoughts of God. For myself, I regard the laws of nature as the most direct evidence possible of Infinite wisdom, and it will be my object to show that this opinion is sustained by the strongest analogies. Regarded from a scientific point of view, physical laws are merely our human expressions of that order which we discover in the material universe. In its highest form, the law is capable of a precise quantitative statement, and gives the basis for mathematical calculation and prediction. Thus the law of gravitation enables the astronomer to calculate what will be the position of the bodies of the solar system at any future epoch, and to predict, almost to the very second, the exact time when an eclipse will begin, and what will be the precise path of its shadow over the earth. The greater part of the laws of nature do not, however, admit of precise mathematical statement, and are merely the expressions of the order which has been observed in the phenomena of nature, whether in respect to form, in respect to number, or in any other particular. It is convenient to distinguish these merely phenomenal laws from the higher class, which are usually called dynamical ; but the distinction is an artificial one, for it is probable, at least, that in all cases the phenomenal laws are merely the phases of some higher dynamical law not yet discovered. Moreover, if we believe that all phenomena are direct manifestations of the Divine Will, then there is no law apart from God. His action is not necessitated or prescribed by any conditions, even although imposed by Himself. He is constantly acting in nature, consciously and freely ; but He acts uniformly, consistently, and with a plan, because He is omniscient and omnipotent. Man acts with inconstancy, because he is a finite being, and must^ be guided by probabilities ; but with God, w^ho seeth the end from tiTe beginning, there is no "variableness, neither shadow of turning.'* The whole material universe may then be regarded as the manifestation of one grand comprehensive creative thought, which God is slowly working out in nature. To study this thought in all its details is the prerogative of man, and this study has been the appointed means of cultivating his intellect and elevating his condition. From time to time the more gifted students have caught glimpses of parts of the grand thought, and these glimpses we call laws ; but even the law of gravitation, the most per- feet of all, is felt to be but a partial f a^^ ana' we ^/ look confidently for the discovery of a Widfep . law /' , which will comprehend Newton's great discover)^ as ^ one only of its manifestations. Let us now, in ordfery to elucidate and confirm this simple doctrine, com- ^ pare some of the laws of nature with the results of human thought, and, whatever may be our theory of causation, we cannot but be impressed with the striking analogy between the two. The idea of symmetry is inherent in every human mind. It may be more or less cultivated by experience, but the germs of the idea are found even in the savage. However rude his condition, man is pleased with a symmetrical disposition of objects, and his taste is offended when the laws of symmetry are grossly violated, although he may have no name for the idea. Corresponding with this idea in our minds, we find symmetry everywhere m nature. The parts of an animal are symmetrically arranged around the body, and the leaves of a plant are symmetrically disposed around the stem, but nowhere in nature is the idea of symmetry so fully developed as in the mineral kingdom. Almost every solid substance, when slowly deposited from a liquid or aeriform condition, assumes a definite symmetrical shape which is peculiar to the substance. These symmetrical forms are called crystals, and the process by which they are obtained is called crystallization. Freedom of motion — such as the particles of matter have in the fluid state — is an essential condition of crystallization. Moreover, as the substance becomes solid, the par- 262 IDEA OF SYMMETRY. tides must have sufficient time to arrange themselves in accordance with the tendency of the molecular forces, and the longer the time occupied in the process of crystallization, the more perfect we find the crystals. The crystal represents the natural condition of a substance, and the peculiar form is the most essential and characteristic of all its properties. Crystals are always polyhedrons, that is, solids bounded by plane faces. Assuming this fact of observation, geometry teaches that the relative positions of the faces of a crystal may be defined by means of three straight lines not all in one plane, but crossing each other at a single point. These lines are called axes, and the common point is called their origin. Now, we can easily conceive of all the possible ways in which three such lines can be arranged, and although the number of possible variations is evidently infinite, yet they can all be classified under a few categories. Again, taking in turn each of these systems of axes, as they are called, we can readily arrange planes symmetrically around the three lines selected for reference, and thus by a process of pure thought, with no other guide than the idea of symmetry as it exists in our minds, we can develop the corresponding geometrical forms, and it is these forms, and these alone, which we find on actual crystals. Moreover, the systems of possible axes correspond to the families under which these crystals are naturally classified. how the forms of what in crystallography is called the regular system, may be developed by arranging planes symmetrically around a system of axes consisting of three lines of equal length at right angles to each other ; but, as a consequence of the attempt to popularize the subject, the illustration was necessarily imperfect, and it became evident that the conceptions involved could only be made intelligible to those who already had some knowledge of crystallography. I shall therefore, in the present volume, leave to the student the task of investigating the details, and simply make the following general statements. Crystals may be studied from two points of view : first, as products of pure thought, like the solids of geometry; secondly, as objects of natural history; and the specimens found in nature correspond, as far as they have been observed, to the deductions of geometry. Furthermore, the lines which we use in constructing mentally the theoretical forms are directions which in the actual crystals are distinguished by well defined physical relations. The products of Nature's laboratory correspond, then, exactly to the results of our own thoughts ; and how can we resist the conclusion that they are the manifestations of the thoughts of an intelligent Creator ? In the language of science, the crystal is said to obey the law of symmetry ; but obviously this law is merely the reflection of the same simple idea which exists in our own minds, and which must have previously existed in the mind of God. The whole science of crystallography is a development of this idea of symmetry. Like geometry, it is a product of pure thought, and its truths are entirely independent of their material forms. Indeed, the mineral kingdom, so far as it is known, does not perfectly represent the idea of symmetry, even as it exists in the human mind. There are possible forms which have never been obtained in nature, and the science, even as we know it, could never have been developed by observation alone. By following out the simple idea of symmetry, which is common to all men, we have found that the results of our own thought perfectly agree with the facts of nature. Let us now take another of the primary ideas which exist in the human mind, and see how fully that is realized in the material creation. The idea of number is as inherent in the mind as that oT symmetry. I shall not attempt to discuss its~dngih " or trace its development ; but assuming, as all will admit, that the results of human skill constantly exhibit simple numerical relations, let us inquire whether the same characteristic may not be discovered in nature. We have already referred to the well-known principle that the position of a plane may be fixed by means of three straight lines or axes crossing at a common point called the origin. If the plane is sufficiently extended it must, of course, cross each of the three axes either at a finite or at an infinite distance from the origin, and if these distances, which we call " parameters," are measured or calculated, the position of the plane is defined. Again, on the crystals of many substances — for example on those of the wellknown minerals quartz, calcite, and barite — we find a RATIO OF PARAMETERS. 265 great number of different planes, which, if not on anysingle crystal, have all been seen on the different crystals of the substance that have been examined. If, now, each of these planes is defined by its parameters, it appears, on comparing the parameters measured on a given axis, that, for crystals of the same substance, the parameters of all the planes are simple numerical multiples of each other. When a plane is parallel to an axis, the parameter on this axis is of course infinity, and this is the most commonly occurring case. As an illustration of the law we. are considering, we may take the crystals of barite — the mineralogical name of the chemical compound called baric sulphate. One of the most commonly occurring planes on the crystals of this substance has parameters which, when measured on the lines usually selected as axes, have the relative values a : b : c = 1.6107: i : 1.2276. There have been observed on crystals of barite no less than thirty-four different planes, and in every case the parameters of these planes conform to the expression a^: b': c^ = m x 1.6107: n x i : px 1.2276, in which m, n, and p are either simple whole numbers, or else infinity. Thus we have for m, n, and p such values as i22; 231 ; 112; 326; 142, etc., and similar facts are true of the crystals of any other substance. Indeed this law of simple numerical ratios is the fundamental law of crystallography, and gives to the science a mathematical basis. Similar numerical relations appear when we study the formation of chemical compounds. I have already defined a chemical element as a substance which has never as yet been decomposed, and all 266 LAW OF DEFINITE PROPORTIONS. the matter with which man is now acquainted is composed of one or more of at most seventy elementary substances. When two of these elements unite together to form a compound body, the proportions in which they combine are not decided by chance. You cannot unite these elementary substances in any proportion you please. The proportion in each case is determined by an unvarying law, and the amounts required of either substance are weighed out by Nature in her delicate scales with a nicety which no art can attain. Thus, for example, 23 ounces of sodium will unite with exactly 35.5 ounces of chlorine ; and if you use precisely these proportions of the two elements, the whole of each will disappear and become merged in the compound which is our common table salt. But if, in attempting to make salt, we bring together clumsily 23.5 ounces of sodium and 35.5 ounces of chlorine. Nature will simply put the extra half-ounce of sodium on one side, and the rest will unite. This law, which governs all chemical combinations, is known as the " law of definite proportions." Tables will be found in works on chemistry which give, opposite to the name of each elementary substance, a numerical value, usually called its atomic weight, and in all cases, where the elements are capable of combining with each other, they either unite in the exact proportions indicated by these numbers, or else in some simple multiple of these proportions. Thallium 204.11 These values are called atomic weights because, according to our modern chemical theory, they represent the relative weights of the ultimate atoms of the elements. If this be the case, it is evident that when the atoms group themselves together to form the molecules"^ of various substances, the elements must combine by whole atoms, that is, in the proportion of the atomic weights, or of a simple multiple of these proportions ; and thus this atomic theory explains the law of definite proportions. In connection with this table a most remarkable fact should be noticed, which indicates the deep significance of this series of values. They are all mutually dependent, so that the same numbers which represent the proportions in which two elementary substances combine with the same quantity of a third substance, represent also the proportion, or a multiple of the proportion, in which they com- * The molecule of a substance is the smallest mass of the substance that can exist by itself, and, when subdivided, it breaks up into elementary atoms, which, however, at once group themselves to form new molecules. bine with each other. Thus not only do i6 parts of oxygen combine either with 1 2 parts of carbon or with 14 parts of nitrogen to form in the first case carbonic oxide, and in the second case nitric oxide, but also 12 parts of carbon combine with 14 parts of nitrogen to form cyanogen ; and the same principle holds for the other weights given in the table, whenever the elements are capable of combining, although, in most cases, only the multiple values appear in the formation of known compounds. The standard of these weights is of course arbitrary ; but if one number stands for pounds, all the rest stand for pounds, or if one stands for ounces, all the rest stand for ounces. It is usual, however, to leave the standard indefinite, and speak of so many parts. Again, the weights have only relative values ; but if we give to any one a definite value, all the rest assume definite values. Our units must necessarily be more or less arbitrary. Most chemists take hydrogen for the unit of weight, and the numbers given in the table express the atomic weights of the other elements calculated on this assumption. But we might take any one of the elem.ents as our starting-point, and formerly the European chemists used a system of weights calculated on the assumption that the equivalent of oxygen was 100. This assumption gives an entirely different system of numbers ; but the difference is of no practical importance so long as the relative values remain unchanged. hydrogen, and he thought that, if the weight of hydrogen was taken as unity, the other atomic weights could all be expressed by whole numbers. The progress of chemistry for a long time, however, did not seem to confirm this view — since most of the accurate experiments made for the purpose of fixing these constants gave incommensurable values, and this was especially true of a most noteworthy investigation, undertaken by Professor Stas, of Brussels, with the view of testing Prout's hypothesis. His experiments, which were conducted with extreme care, and with very large amounts of material, gave incommensurable values, and the results were thought at the time to show that the hypothesis in question was wholly illusory. Still it was remarkable that the values obtained by Stas differed from whole numbers only by a small fraction of a unit, and in the accurate determinations which have since been made by other chemists, the same striking feature appears. The nineteen atomic weights, whose values are given in the above table, may be fairly considered as the only ones which have been determined, with reference to hydrogen, with the greatest attainable precision, or a near approach thereto, and it will be noticed that, with the exception of the atomic weight of chlorine, the values differ in no case from a whole number by more than fifteen-hundredths of an integer, and generally by much less. If the atomic weights are in fact whole numbers, such slight differences from the true values as these in the observed results are exactly what we should expect, seeing that no determinations of this kind can with certainty be freed from the influence of constant experimental errors. On the other hand, if the true weights are incommensurable and distributed by chance, the probability that the observed values would all lie so near to whole numbers as they do would be exceedingly small, and hence the total result, as far as it goes, may be said to confirm rather than invalidate Prout's hypothesis. But leaving this question to be decided by further investigation, let us turn to an allied class of facts, which exhibit a very simple numerical relation, that cannot be questioned, and which, indeed, by analogy furnish a certain presumption in favor of the hypothesis of Prout. In very many cases the same elements, by uniting in different proportions, form several distinct compounds, and we invariably find that the proportions of the elements in the different compounds bear a very simple numerical relation to each other. Thus there are five compounds of oxygen and nitrogen, which contain these elements in the proportions indicated in the following table. these compounds are in all cases simple multiples of eight, the proportion in the first. In like manner, the compounds of manganese with oxygen show similar relations. The relation is not quite so simple as in the other case, but still the same general truth is evident, and these two examples are fair illustrations of what has been observed throughout the whole range of chemical compounds. Thus we find in these elementaryforms of matter — the blocks with which the universe has been built — the same simple numerical relations which everywhere appear in the constructions of man. Similar numerical relations are found throughout the whole universe of matter. In the solar system, for example, with the exception of Neptune, the intervals between the orbit of Mercury and the orbits of the other planets go on doubling, or nearly so, as we recede from the Sun. Thus the interval between the Earth and Mercury is nearly twice as great as that between Venus and Mercury, the interval between Mars and Mercury nearly twice as great as that between the Earth and Mercury, and so on. Again, if we compare the periods of revolution around the Sun, expressed in days, we It will be noticed that the period of Uranus is \ that of Neptune, the period of Saturn \ that of Uranus, the period of Jupiter about f that of Saturn, the period of the Asteroids about f that of Jupiter, the period of Mars about -^ that of the Asteroids, the period of Venus about /y that of Mars, and the period of Mercury about if that of Venus. The successive fractions are very simply related to each other, as will at once appear on writing them in a series, Notice that, after the first two, each succeeding fraction is obtained by adding together the numerators of the two preceding fractions for a new numerator, and the denominators for a new denominator. From this series, however, the Earth is excluded. Its time of revolution is almost exactly -^^ of that of Mars, and that of Venus nearly -\|f of that of the Earth ; but although these fractions do not fall into the above series, they are members of a complementary series beginning This simple relation was discovered by Professor Peirce, and he has proposed an explanation for the anomaly presented by the Earth. But it is not important to dwell on this point. My only object has been to show that simple numerical relations appear in the planetary system, and this, as I trust, has been fully illustrated. Passing now to the vegetable kingdom, we fina again the same numerical laws. The leaves of a plant are always arranged in spirals around the stem. If we start from any one leaf, and count the number of leaves around the stalk and the number of turns of the spiral until we come to a second leaf immediately over the first, we find that for any given plant, as an apple-tree fqr example, the number of leaves and the number of turns of the spiral are always absolutely the same. The simplest arrangement is where the coincidence occurs at the second leaf, after a single turn of the spiral ; and this may be expressed by the fraction ^, whose numerator denotes the number of turns of the spiral, and whose denominator the number of leaves. The next sim^ plest arrangement is when the coincidence occurs at the third leaf, after a single turn of the spiral, and may be expressed by the fraction i. These two fractions express respectively the greatest and the LAW OF PHYLLOTAXIS. smallest divergence between two successive leaves which has been observed. The angle between two successive leaves, therefore, is never greater than 1 80°, or half the circumference of the stem, and never less than 120^, or one-third of the circumference. The arrangement next in simplicity is where the coincidence occurs at the fifth leaf, after two turns of the spiral, as is represented in the preceding figures. Other examples are given in the table which follows, and it will be seen that we have precisely the same series of fractions in the arrangement of leaves around the stem of a plant which appears in the periods of the planets. The fractions of this series are all gradual approximations to a mean fraction between ^ and \|, which would give the most nearly uniform distribution possible to the leaves, and expose the greatest surface to the sun. But this law does not stop with the plants. The same series of fractions expresses also the spiral arrangement of the tentacles of the Polyp and of the spines of the Echinus. Thus through the whole realm of nature, from the structure of the crystals to the dimensions of the human form, a similar numerical simplicity is preserved. Have you never recognized the composition of your friend in some anonymous literary article, by a peculiar phraseology, a turn of style, or a method of thought which no artifice could conceal ? Have you never felt a glow of pleasure when you unexpectedly discovered on the walls of a picture-gallery the work of a well-known artist, marked by some peculiarity of grouping or coloring? Has your attention never been quickened when an orchestra has suddenly struck into a new theme of a favorite composer, never heard before, but unquestionably his? If you have experienced these or similar emotions, you know something of the force with which such numerical laws impress the mind of the student of nature, and you also know how difficult it is to make the power of such impressions understood. I wish I could givQ you a full conception of this power ; for you cannot otherwise feel the full force of the evidence which these facts afford. They point directly to an intelligence in nature like our own, and man was created in the image of his God. The broken porticoes of the Parthenon still stand on the Acropolis at Athens to incite the imitation and win the admiration of the architect. That beauty of outline and those faultless proportions, which modern art has copied but never excelled, all depend on an exact conformity of all the parts to the laws of symmetry and to simple numerical ratios. We justly regard that ruined temple as the evidence of the highest intelligence ; and when we find the same symmetry, the same numerical ratios, appearing everywhere in nature, how can we refuse to admit that they also are the evidence of intelligence and thought ? Moreover, since the laws of symmetry and number pervade the whole universe, from the structure of the solar system down to the organization of a worm, they prove, if they prove anything, that the whole is the manifestation of the thoughts of the one great Jehovah, who " in the beginning " created all things by the word of His power. I have thus endeavored to show that the laws of nature, so far from proving that the world is governed by an inexorable necessity, furnish the strongest evidence of an overruling mind. We must be careful, however, not to misinterpret this evidence ; for analogies like those we have studied led Schelling and the philosophers of his school to regard outward nature not merely as the result of Divine Thought, but as identical with that thought, and inseparable from it. Indeed, there are many among us who re- gard the material universe as the manifestation of God, in the same intimate sense in which our bodies are the manifestation of our own personality; who therefore believe that the world is and always has been a part of His Eternal Being, and who look upon the laws of nature not merely as the manifestation of an Infinite Intelligence, but as a part of that Intelligence itself. This philosophy may be made to appear very attractive, and even very reverential ; but when followed out to its logical consequences, it reduces God to the level of nature, and merges His being in the matter He created.. We must be as careful to avoid the snares of pantheism, as the slough of materialism. Both are equally destructive of true religion, and, although they lie on opposite sides of the Christian's path, they lead to the same result ; and if once enticed from the narrow way, the Christian will be fortunate if Faith rescues him from the peril before he falls into the gulf of atheism. We must not confound the Creator with the creature. There is a personal God above all and over all, and although nature manifests His intelligence, its material forms are only the reflection, not the substance, of His Being. The error of the pantheist arises from a too superficial study of nature, and if we examine more closely the analogies between the laws of nature and the results of human thought, I am confident we shall find that the created forms may be readily distinguished from the Intelligence which gave them being. 278 CONCEPTION AND EXECUTION. last never exactly conforms to the first. For example, in one of the grand Gothic cathedrals of our mother country we see united in the plan, first, the idea of the cross, the emblem of our Christian faith ; then the spire, typifying the aspiration of the soul ; and lastly, the long aisles, whose pointed arches and delicate tracery have been copied from the interlacing branches of God's first temple. The combination of these ideas may be said to be the conception of the cathedral ; but how differently has this conception been embodied in the numerous cathedral churches of England ! Besides the peculiar caprices of the architect or builder, we can trace in each church an evident adaptation of the parts to special purposes. Here a " lady chapel ** has been included in the design, and here the mausoleum of a king or a prelate ; here a portion has been adapted to the reading of the service, and here to the session of the ecclesiastical court ; but however varied the execution, the same conception is evident in all. So it is in all architecture. Our modern dwellings are built after a few general types, and the conception is very nearly the same in all houses of any one class. But how differently a skilful architect will arrange the details, and adjust them to the circumstances of the location, to the wants of the family, or the taste of the owner! and no one knows better than he that the conception of the building is one thing, and the execution of that conception a very different thing. In the higher forms of art, the same truth appears even more strikingly. The Transfiguration of Raphael, that masterpiece of painting, does not hold DISTINCTION ILLUSTRATED. 279 you breathless before it so much by what it actually represents, as by what it embodies and helps you to realize. He who sees merely what is painted on the canvas will turn away disappointed, but in the soul of the true student of art, who enters into the spirit of the great painter, the conception grows as he gazes, until he becomes transported and gains a vision of the splendors of the Mount. In like manner, it is not that lovely female face which has endeared the Sistine Madonna to so many hearts, and made Dresden one of the shrines of the world. In mere point of execution, this picture may be surpassed by many works of living artists ; but the conception of a pure mother's love has been nowhere embodied as there, and that is the charm. You stand before the Laocoon until the blood runs cold and the muscles writhe in sympathy, and then you look at the motionless statue and wonder whence comes the power. It is not in the skilfully chiselled marble, but it is in the conception of the unknown artist, which the petrified forms suggest. So it is everywhere with the works of man ; the conception can always be distinguished from the embodied fact. But what need of illustration ? Who does not know the difference between the two, and who has not sadly experienced how far his best efforts fall short of his ideal? The thought, the conception, how noble ! the execution, the reality, how humble ! Turning now to Nature, we find the same distinction there between the conception and the facts. Nature does not, of course, like man, fall below her ideal for want of power, but she departs from it in order to 28o ILLUSTRATED BY CRYSTALS. adapt her work to specific ends, or to accommodate it to conditions and accidents of various kinds ; and everywhere the conception, or, as we generally call it, the law, is modified in the execution, so that the actual can be plainly distinguished from that which our minds have recognized as the ideal. Review for a moment, with this idea, a few examples of natural laws, beginning with the law of symmetry. We seldom, if ever, find in nature crystals having that regularity of form or that perfection of outline represented in our figures. Natural crystals are almost invariably more or less distorted or imperfect, and a perfect crystal is at best a very rare exception. It is true that in all cases of distortion the relative inclination of the planes is very nearly constant ; but even this is liable to a slight variation. Moreover, many of the ideal forms of crystals are never found in nature, or if at all, not in their perfection. They are at best merely shadowed forth, as it were, on other forms, and so partially that the unpractised eye would never detect them. So true is this, that, as I have before stated, the present science of crystallography could never have been developed by observation alone. How evident, then, the distinction between the actual crystals and the thought which they embody ! Crystallography is worthy of special study from this point of view. Of all the departments of natural history it most nearly approaches a perfect science. The conceptions involved are so simple that they have been grasped by the human understanding with a completeness which has nowhere else been reached, and we feel confidence that, to a great extent at least, we comprehend the plan. Hence in this science the distinction on which we are here insisting becomes plainly marked, but of course the truth can be realized in its fulness only by the students who have mastered the subject. In striking contrast to the completeness of the science of crystallography, is the present obviously rudimentary condition of the theory of chemistry ; but even in this subject, although the thought has been so imperfectly comprehended, the distinction between the governing plan and the material manifestation is perfectly clear. The various attempts to classify the chemical elements according to their natural affinities have never been more than very partially successful. This arises chiefly from the complex relationship which many of the elementary substances manifest, and different authors may reasonably assign to such elements different places in their system of classification, according as they chiefly view them in one or the other aspect. Indeed, no classification in independent groups can satisfy the complex relations of the elements. These relations cannot be exhibited by a system of parallel series, but only by a web of crossing lines, in which the same element may be represented as a member of two or more series at once, and as affiliating in different directions with very different classes of substances. These attempts at classification have, however, made conspicuous one feature in the scheme of the chemical elements, which seems to be fundamental. It appears that as the atomic weight increases, ele- 282 SCHEME OF THE CHEMICAL ELEMENT. merits having closely allied properties occur at nearlyregular intervals, so that with Mendelejeff we can arrange the elements in the order of their atomic weights in a series of horizontal lines containing each about seven members, and bring into the same vertical columns only elements which belong to the same natural family, or at least are allied in some respect. Tables of the elements so arranged will be found in most of the recent works on chemistry,^ but necessarily the scheme is intelligible only to those who are already familiar with the properties of the elementary substances, and it would be out of place to enter into the details in this book. As in almost all classifications of natural objects, the observed facts require considerable humoring in order to accommodate them to the scheme, and, moreover, the elements that are brought together in the vertical columns are frequently allied by only one set of their properties, while in other respects they are equally or even more closely related to elements from which they are widely separated by the system. Still no one who studies the subject can fail to be impressed with the general fact that there is an orderly recurrence of similar qualities in the series of the elements. Moreover, the discovery of the new element gallium has filled one of the obvious gaps in the series, as originally constructed by Mendelejeff, and the qualities of this remarkable metal closely conform to those which he had predicted for the missing member of the series ; furthermore, some atomic weights. The glimpses that we have thus been able to gain of the order in the constitution of matter, give us grounds for believing that there is a unity of plan pervading the whole scheme, and encourage a confident expectation, that hereafter, when our knowledge becomes more complete, chemists may attain to at least such a partial conception of this plan as will enable them to classify both elementary and compound substances under some natural system ; and in imagination we may even look forward to the time when science shall succeed in expressing all the possibilities of this scheme in a few general formulae, which will enable the chemist to predict with absolute certainty the qualities and relations of any given combination of materials and conditions. But although to a very slight extent the idea has been realized for the compounds of carbon, yet, as a whole, this grand conception is to-day only a dream. There is a point connected with the classification of the chemical elements which is deserving of our notice in this connection. We have already seen that, although some seventy elements have been discovered — several of which, however, are as yet of doubtful authenticity — -the greater portion of the earth/s crust consists of only ten or twelve. Indeed, if the remaining fifty elements were suddenly annihilated, the mass of the globe, so far as we know, would not be sensibly diminished. Indeed, a large 284 THE RARE ELEMENTS. number of the elements occur in such minute quantities that they can be detected only by the most skilful chemical analysis. That these very rare elements were designed by the Creator to subserve important ends, we need not doubt ; but it is certain that they play a very subordinate part on the surface of the globe. For bromine and iodine, and a few others, important applications have been discovered in the arts or in medicine ; but the rest, comprising at least one-third of all the known elements, have no apparent value except as parts of a general plan. In the light of a utilitarian philosophy they must appear useless ; but to the true student of nature they have a significance which transcends everything else. They are parts of a universal order, of a Divine cosmos, which would be incomplete without them. They are the manifestation of Infinite Intelligence. They embody the thoughts of God. In the words of Chevalier Bunsen, " Law is the supreme rule of the universe, and this law is intellect, is reason, whether viewed in the formation of a planetary system or in the organization of a worm.'* But we must remember, in discussing this question, that it does not follow, because we cannot discover any important end which these elements subserve on our earth, that they have no practical utility. For after acknowledging the dignity which they acquire when regarded as the characters of that language in which the creative thoughts have been written, and as the appointed means of educating the human race, still it does not seem consistent POSSIBLE USES. 285 with that economy of resources which appears in all parts of the Divine plan, that they should have no special functions to discharge in the cosmos. Now I would suggest, but I offer the suggestion in all humility, that these very rare elements may be adapted by their peculiar properties to the thermal conditions of some other planet or some other stellar system. We have seen that those elements which are the most widely distributed over the earth are such as are adapted by their properties to the conditions of organic life on the third planet of the solar system, and it is certainly possible that some different scheme of organic life may be sustained on Mercury or Uranus, in which elements rare to us take the place of oxygen, nitrogen, hydrogen, and carbon, and perhaps also the elements missing in our classification may be found in some other world, revolving around Sirius or Arcturus, where oxygen, sulphur, and iron may be among the rarities of science. All this is, of course, the purest hypothesis, and such speculation can lead to no positive results ; but the very possibility of such speculations as those in which we have been indulging in this connection illustrates most pointedly the great truth I am endeavoring to enforce. The thought embodied in the scheme of chemical elements is something entirely apart from their material forms, and the moment this thought is apprehended by man, it opens to his imagination vistas of possible realities which entirely transcend all human experience. 286 ILLUSTRATED IN ASTRONOMY. If next we compare, more carefully than before, the periods of revolution of the planets around the Sun, we shall find that the same general principle holds true. The observed periods, you will notice by the table on page 272, do not exactly correspond to the simple ratios which express the law, and the same is true of the distribution of leaves around the stem of a plant, and in fact of all classes of phenomena in nature. In each we observe only a tendency towards a maximum effect, which is the perfect expression of the law, but which is seldom fully reached. The limits of variation are broader in some cases than in others, but we find no case in which the accordance is absolute. In none, however, of the purely physical laws is this character so strongly marked as in the structure of animals and plants. It is well known that all organized forms, although so wonderfully diversi-* fied, are fashioned after a few general types. In the animal kingdom there are only four general plans, represented by the Radiata, the Mollusca, the Articulata, and the Vertebrata, and all the animals of any one of these great divisions are organized alike. For example, in all vertebrate animals we find essentially the same parts ; and similar homologies, as they are called, may be traced throughout the animal kingdom, and any anatomist will point out to you in the skeleton of a fish, of a reptile, of a bird, or of a quadruped, the bones which correspond to the various parts in the skeleton of a man. In the wings of a bat the bones of the human arm may readily be traced. Moreover, very frequently when there is no use for a given organ, it is still present in a rudimentary condition. Professor Wyman found rudimentary eyes in the so-called eyeless fishes of the Mammoth Cave, and equally striking examples of the same general truth are familiar to every one. Here, then, is a most obvious distinction between the conception and the execution, and the general plan of the skeleton is preserved, even where there is no use for certain parts, and where we might perhaps conceive of a simpler arrangement without them. But, more than this, we find that the variations from what we may regard as the typical form have been obviously made in order to adapt the organs to certain specific ends. The same plan which, developed in its full perfection, appears in the human hand and arm, reappears, more or less fully carried out, in the fore legs of a horse, in the wings of an eagle, and in the pectoral fins of a dolphin ; and in each case the organ has been obviously adapted to some special purpose. Special adaptation has thus been most beautifully harmonized with general law, and the conception has been varied in the execution in order to secure some wise and important end. We, of course, do not forget that the rudimentary organs to which we have referred are looked upon by the evolutionists from a very different point of view, and constantly cited as among the strongest evidences cf the truth of their theories ; that they are regarded by them as the survivals of a previous, condition in which they played their appropriate parts, and as an inheritance which marks the ancestry 288 SURVIVALS AND TYPES. of a species, as family traits often mark the ancestry of an individual : and although, as it seems to us, this explanation of the origin of rudimentary organs will not hold in all cases, we at once admit its wide application, and we leave all such questions of proximate causes to the naturalists, to be decided on scientific evidence, and on that alone. But we claim that the facts are perfectly consistent with the operation of an intelligent first cause, and that this more comprehensive interpretation, so far from excluding, includes all temporary influences and subordinate effects. This subject is capable of almost indefinite illustration, and the vegetable kingdom is as rich in examples of the principle we have been discussing as the animal. I have not, however, time for further details. The whole ground has been most carefully surveyed by McCosh and Dickie in their excellent work entitled ^* Typical Forms and Special Ends in Creation," and to this I would refer those who may be interested to pursue the study of these singular facts. Sufficient, I trust, has already been said to show that the phenomena of nature and the results of human thought resemble each other in their very incompleteness. While, therefore, a more careful study has tended to confirm the result at which we arrived in the last chapter, and has strengthened the impression that the universe was created by an intelligence like our own, we have also found that the analogies of nature point with equal distinctness to the conclusion that this intelligence is a being entirely apart from and MANIFESTATION OF INTELLEGENCE. 289 infinitely superior to the matter he created or the laws he ordained. If these analogies are worth anything, they point not to a spirit of the universe, pervading and energizing matter, but they prove the existence of a personal God ; one who can sustain to us the relations of Father, Saviour, and Sanctifier; one whom we can love, worship, and adore. But it may be urged that I have drawn my illustrations wholly from the phenomenal laws of nature, and entirely overlooked the great dynamical laws, which, like the law of gravitation, are more precise. Moreover, it will be said that the history of astronomy gives us every reason to believe that these very variations, to which I have assigned such importance, are merely necessary consequences of some higher law not yet discovered, just as the perturbations of the planetary orbits are the legitimate results of the very law they seemed at first to invalidate. I have no doubt that in part, at least, this will be found to be the case. But even in regard to the law of gravitation, there always have been residual phenomena, unexplained by the law, and so probably there always will be, until, as we go on widening our generalizations, the last generalization of all brings us into the presence of that First Cause through whom and by whom all things are sustained. I trust that the striking analogies between the phenomena of nature and the results of human thought, which I have been able so imperfectly to illustrate, have impressed you, as they impress me, with the profound conviction that the order of nature 290 ASPECT OF NATURE. is the manifestation of an Infinite Intelligence, but of an Intelligence apart from, and superior to, the cosmos which it once created and now upholds. If I have failed in my object, it is because I have been unable to bring home these analogies to your understanding. The resemblances are so striking, that I do not believe a mind which is conversant with the facts, and unbiassed by the prejudices of philosophy or of education, can resist the conclusion that this scheme of nature is the manifestation of an intelligence like our own, at least so far as the Infinite can be said to resemble the finite. Men may reasonably entertain differences of opinion in regard to the mode of action of that Being who has created the universe. They may believe that a certain amount of power, together with the germ of all future existence, was implanted in the original chaos, and that the Deity has never interfered with the natural action and the unfolding of the causes which He has thus ordained ; but whatever theories of cosmogony may be entertained, short of absolute materiahsm, he must be indeed blinded by his prejudices who refuses to recognize in these analogies the evidence of intelligence and thought. I do not, of course, regard analogies as proofs, nor do I believe that this argument from general plan could supply the place of the great argument from Design. The last lies at the basis of Natural Theology, and all the rest is merely subsidiary to the great central light. Moreover, while the argument from design comes home to every mans understanding, these analogies appeal with their full force only HUMAN SYMPATHY WITH NATURE. 2gi to the few who are able to study the processes of nature for themselves, as they alone are familiar with the phenomena in which the resemblances are seen. But to the student, whose life has been passed in successful investigation, and whose soul has been brought into sympathy with the harmonies of nature, these tokens are constantly assuring him of the presence of his God. Every discoverer feels — when in brought face to face with a great truth, he cannot resist the feeling — that, in discovering a law, he has been brought nearer, not to a blind agency, but to Omnipotence itself. To this conclusion he is not led solely by philosophy ; for although he may defend his conviction on reasonable grounds, in its full power it transcends all human philosophy. Man cannot always tell why he knows. But when illuminated from the altar of his faith, all nature wears a new aspect, and his spiritual eye discovers everywhere acting that same Infinite Intelligence which "spake in time past unto the fathers by the prophets," and ' hath in these last days spoken unto us by his Son." Do I hear it said that such loose reasoning is a gross violation of the Baconian philosophy, and of that severe induction by which alone science has been built up ? But do we not know, have we not seen, that the whole structure of science rests on no firmer foundation than these very analogies of nature, — that at the beginning of all knowledge, where we should most expect infallibility, we find only uncertainty and doubt ? 292 SCIENCE RESTS ON FAITH. his Maker, its unfinished spire pointing to heaven, but its foundations resting on a cloud. The work has been done as well as faithful hearts and active hands could do it. Examine its walls and its buttresses, and from base-stone to coping you will find no defect. Each block has been so carefully wrought and so firmly clamped in its place, with all the strength of iron logic, that you will unhesitatingly conclude that the mighty structure has been reared, not for time, but for eternity. Yet it all rests on a cloud. Let that cloud be dispersed, and only God can tell whether the structure shall stand or fall. Are we then, you will ask, to mistrust these boasted results of science ? Is this imposing structure all a phantom, a mere day-dream, from which we shall awake on the morning of eternity to find all passed ? Certainly not ! God has not endowed his creature with faculties of observation merely to delude him, and with an intellect solely to lead him into error. He has not raised up the long line of scientific heroes of every age, merely to deceive themselves and mislead the world. No ! the temple of science will stand fast. That cloud on which it rests is a firmer foundation than any granite rock ; for it is not of man, but of God. Yet let us not forget that this assurance is based only on the same faith which is the " substance of things hoped for, the evidence of things not seen." ' We have but faith : we cannot know ; For knowledge is of things we see ; And yet we trust it comes from Thee, A beam in darkness : let it grow." LIGIOUS THOUGHT. I HAVE endeavored to show that the evidence which all nature affords of a personal God is wholly independent of the theories of cosmogony we may assume. But although our doctrine of causation may not impair the evidence of an original design, it is not so with the other bearings of the subject. For if nature be a mere machine, weaving the complex web of destiny with the same precision and certainty with which a carpet-loom weaves the pattern of a carpet, then the Christian's idea of a superintending Providence cannot be true. If nature has been evolved solely under necessary conditions and laws, with which the Creator has never interfered since he wound up the immense weight which set the whole in motion and still maintains the preordained beats of the great pendulum of the universe, — if with an archangel's intellect we could predict every event in nature with the same certainty with which we now foretell the phases of an eclipse, — then I say again that the visions of an overshadowing Providence which have appeared to 294 SUPERINTENDING PROVIDENCE. US at those milestones on our life's journey where, wearied and disheartened, we have sat down to rest, are nothing but a delusion and a dream. It does not remove the difficulty here referred to, to say that our lives are parts of this preordained plan, or even to admit that God may interfere in the moral world by influencing the will of man; for every one is conscious that his will has not been thus directly influenced, and knows, moreover, that the circumstances of his condition have always concealed, at the time, the kind Providence by which he has been led. And when your theory leads to this, that man has been put into a world of probation and trial, and there left to walk over pitfalls with his eyes blinded, every unsophisticated mind will feel — say what you will — that the character of the God you worship is more truly symbolized by the car of Juggernaut than by the cross. A great deal of false prejudice against scientific study arises from a mistaken impression that the materialist's interpretation of nature is the natural and necessary result of all scientific thought. Hence not a few religious minds have concluded that the methods of science must be all wrong, and its conclusions wholly untrustworthy. It will not, therefore, be out of place in this connection to consider briefly whether the materialist's idea of causation is the necessary, or even^the probable conclusion to which the observed facts of nature and the legitimate methods of science lead. We must remember, however, while discussing this subject, that we have passed the limits of human knowledge, and IDEA OF FORCE. 295 cannot therefore expect by our unaided processes of thought to prove or disprove anything. We cannot determine absolutely whether the materialist's theory be true or false ; for science has not the knowledge which would enable it to form a decision. The only question for us is, whether this theory is the necessary theory, or even the most probable theory ; and if it is not either the one or the other, then the theory is of no weight. One man's theory is as good as another's, provided both are equally consistent with facts. If, then, we can show, on scientific grounds alone, that the Christian's theory of causation is as probable as the materialist's, we shall in regard to this point also fully sustain the position we have taken in regard to scientific studies. Surely science is no more responsible for the excesses of theorists than is religion for the crimes of bigots, and it should be sufficient to satisfy any religious mind, that there is a Christian theory which is perfectly consistent with all known facts. It is easy to understand the relative position of the two theories of causation after we have become acquainted with the facts which both must necessarily explain. Let us review, then, very briefly, these facts, which are more or less familiar to every one. An innate principle of the human mind compels us to believe that every change must have an adequate cause, and leads us to refer the phenomena of nature to what we call forces. Thus the falling of an avalanche, the flowing of the tides, the beating of the waves, the blowing of the winds, the crashing of the lightning, the burning of the fire, the moving power of steam, and the impression of light, must all have an adequate cause, and to this cause we give the name oi force. We use this word so frequently and so familiarly that we are apt to think that we associate with it a definite conception ; but a moment's reflection will show that in regard to the nature or origin of force we have no absolute knowledge. This word is merely our name for the unknown cause of natural phenomena. The uneducated mind naturally refers the origin of all force to the bodies from which it appears to emanate, and regards it either as a quality inherent in matter, as in the phenomena of gravitation, or as a property superimposed upon matter, as in the phenomena of light, heat, magnetism, and electricity. In either case, however, it is regarded as a quality of matter. Moreover, the uneducated mind, impressed most of all by the great diversity in physical phenomena, naturally infers that a similar diversity exists in the forces which produce them, and thus is led to the idea that there are different kinds of force. Hence men have been led to refer the falling of bodies towards the earth to a distinct force called gravitatioit, the motion of a steam-engine to another force called heat, the burning of a candle to a third force called chemical affinity, and in like manner to each class of phenomena they have assigned a peculiar and separate force. Such ideas as these are natural in the infancy of knowledge, and we must remember that, with all our boast of progress, the human race, so far at least as physical science is concerned, is yet in its childhood. The law of gravitation was discovered only two centuries ago, and almost the whole of the present sciences of chemistry and physics has been developed within the lifetime of men now living. Many of the present generation were educated in those very natural, but crude notions, and it is not until a comparatively recent period that even scientific men have been persuaded that these primitive ideas must be wholly abandoned, or at least radically modified. We are now in a transition stage, and hence arises a great difficulty in discussing the subject. The language even of modern science is based upon the old ideas, and we cannot describe natural phenomena without using terms which imply what almost all thinkers now believe to be erroneous notions. Hence, when we attempt to present spiritual views of the origin and nature of force, we are obliged to use terms which imply the opposite, and our very language appears to condemn us, or at least prejudices our theory. This is especially true of the word force itself, and we must carefully bear in mind that the origin of phenomena is not explained because, in the language of science, they have been referred to an assumed force with a high-sounding name. Names are not things, and we know nothing more of the cause which brings the apple to the ground because Newton has called it the force of gravitation, than we did before. He gave us the law of the motion, and enabled us to predict how every apple would fall, and how every planet would move throughout space, but the cause of the motion is as closely hidden as ever. In regard to the law of gravitation we 13 298 TRANSFER OF ENERGY. know a great deal ; but in regard to the force of gravitation — whatever we may think or believe about it — we know absolutely nothing, and the same is true of every other force. The most remarkable feature of modern science has been the constant tendency of all investigations, during the last fifty years, to show that the same energy, if only differently applied, may produce the most diversified phenomena; and now almost all the so-called forces of the old philosophy appear to be mutually convertible. Thus — to begin with a lump of coal — as we have seen, a certain amount of latent energy resides in that black mass, which has been called the force of chemical affinity. Burn the coal, — that is, combine it with oxygen, — and the affinity is satisfied, but the energy reappears as light and heat. If the coal is burnt under a steam-boiler, the heat expands the water and converts it into vapor, and then we find the energy again in the expansive force of steam. The steam expands against the piston of the locomotive, and the energy passes into the moving train. The rapidly moving mass, in forcing its way through the air and over the iron track, is constantly losing its moving power in consequence of the friction it encounters ; but the energy is not lost, and if we could follow it, we should find it reappearing somewhere as heat. Suddenly the engineer opens a valve, and a portion of the energy of the steam gives motion to the air, and the effect is a shrill whistle. The brakeman applies the brakes, and the train after a few moments comes to rest. Its moving power is gone, but the energy is not lost. smoking brake shows where the energy has gone. Return now again to the lump of coal, and, instead of burning it under a steam-boiler, heat it in a properly constructed furnace in contact with roasted zinc ore. This ore is a compound of zinc and oxygen. The coal, in order to satisfy its intense affinity, seizes on the oxygen and sets the zinc free. But although the chemical affinity of the coal has been satisfied, no power has been lost ; for the energy which was before latent in the carbon is now latent in the zinc. Dissolve the zinc in dilute sulphuric acid, and the chemical affinity of the zinc will be satisfied, and, if certain conditions are fulfilled, the energy will take the form of a current of electricity. Cause this current to flow through a platinum wire, and this energy will appear in the heat and light radiated from the glowing metal. Cause the same current to flow in spiral lines around a bar of iron, and we find the energy again in the attractive force of an electro-magnet. Connect with the electro-magnet appropriate machinery, and the same energy may be so applied that it will move a light boat or turn a small lathe. Lastly, connect with the dissolving zinc four thousand miles of iron wire, and the energy will be transmitted across a continent with the velocity of thought, and write in a distant city the message which it carries. Illustrations like these might be multiplied indefinitely ; but enough, I think, has been said to show that, to all appearance at least, the same energy may be transferred from one mass of matter to another, and that thus, while nothing but the mode of application has been changed, the power may reappear under entirely different manifestations, and produce phenomena wholly unlike those in which it was but a moment before the active cause. The truth of this principle becomes still more evident when we apply in our experiments exact measurements; for we find that in all these transfers of energy from mass to mass the power reappears undiminished. It may remain latent for a time, as in a mass of coal, but sooner or later it will reappear without having undergone the slightest loss. We must here dwell for a moment upon an important distinction, which has already been implied, between latent and active energy. It is a distinction with which every one is practically familiar, and it may therefore be made clear by referring to a few examples. A weight falling to the ground from a i given height is an example of active energy, while an equal weight suspended at the same height represents an equivalent amount of latent energy. In winding up a clock, muscular energy becomes latent in the suspended weight, but reappears in mechanical motion as the clock runs down. So also a lump of coal, as already stated, represents a certain amount of latent energy. When the coal burns, its energy becomes active, and takes the form of heat. Again, in smelting zinc ore there is transferred to the product a portion of the latent energy of the coal used in the furnace ; and if in a voltaic battery the resulting zinc dissolves in sulphuric acid, this energy becomes active, and reappears in a current of elec- ENERGY NEVER LOST. 30I tricity. Some persons do not like the term latent energy, and speak of energy which is not in action as possible or potential. In like manner they speak of energy in action as actual or kinetic. But terms are of no importance, if only the ideas which they express are fully understood. Keeping this distinction in view, we shall better understand the bearings of the important principles just before stated. When energy, in passing from one body to another, changes its mode of manifestation, it seldom flows wholly into one channel, and almost invariably more or less of it becomes latent. Thus — to go back to the example of the steamengine — of the energy, which is latent in the coal and becomes active in the form of heat when the coal burns, not more than one-tenth, at the most, produces any useful mechanical effect. The rest becomes again latent in changing the water into steam, and in heating and expanding the iron, the bricks, the water, and the air in contact with which the fuel burns. All this heated matter represents a large amount of latent energy. It is in the condition of the wound-up weight of a clock, and, as it cools, this energy is distributed to surrounding bodies. Were it possible, at a given instant after the burning of the coal, to sum up all the energy, both active and latent, which could be traced directly back to the burning fuel, it would be found that not the smallest fraction of the energy originally in the mass of coal had been lost. In this case, of course, accurate experiments are out of the question ; but wherever it has been possible to apply 302 CONSERVATION OF ENERGY. measurements, it has been found that the principle here illustrated holds true. I should not be able to make the methods of such investigations intelligible without occupying a great deal of time. Let it then be sufficient to state, that all those who have most carefully studied the subject have arrived at the same results. There is, therefore, every reason to believe that the principle we have been illustrating is universally true. Let us then embody it in a definite statement. All natural phenomena are the manifestation of the same omnipresent energy, which is transf erred from 07ie portion of matter to another without loss. But if the principle as thus stated be accepted, we cannot rest here ; for it involves this further conclusion, which, however marvellous, must be true. The sum. total of all the active and latent energies in the universe is cojistant a?id invariable. In other words, power is as indestructible as matter.^ This grand truth is generally called the law of conservation of energy, and, if it cannot as yet be regarded as absolutely verified, there can be no question that it stands on a better basis to-day than did the law of gravitation one hundred years ago. But how can I give you any conception of the sublimity of the truth which this formal language implies, but which no language is adequate to express? Even poetry, in the highest flights of fancy, has never seen such a vision as these vistas of actual * Many philosophers believe, with Newton, that matter in its essence is only a manifestation of power, and if so the conservation of mass in nature is only a phase of the conservation of energy. realities open to the intellect and imagination of man. Review in the light of this grand generalization the subsidiary truth which from time to time I have endeavored to illustrate in this work, — namely, that all terrestrial energy comes from the sun. The accumulated power of the sun's delicate rays produces, as we before saw, every motion and every change which takes place on the surface of this planet, from the falling of an avalanche to the. crawling of a worm. But that energy, as we now know, is not exhausted on the earth. To use the eloquent language of another : ^^ Our world is a halting-place where this energy is conditioned. Here the Proteus works his spells ; the selfsame essence takes a million shapes and hues, and finally dissolves into its primitive and almost formless form. The sun comes to us as heat ; he quits us as heat ; and between his entrance and departure the multiform powers of our globe appear. They are all special forms of solar power, — the moulds into which his strength is temporarily poured, in passing from its source through infinitude." ^ Attempt now to bring together in imagination all the energies acting at one moment on the earth, and unite them in one tremendous aggregate. Begin with the moving power of the air, the hurricanes, the tornadoes, the storms, and the gentler winds which are everywhere at work from the Arctic to the Antarctic Pole, omitting in making the estimate, if 304 SOURCE OF ENERGY. you choose, the Hghtning and the thunder, which, though brilliant and noisy demonstrations of power, would hardly increase by a unit the vast sum. Add to this the mechanical power in the mighty flow of waters, the ocean currents, the rivers, the cataracts, the glacier-streams, and the avalanches, all over the globe. Bring into the calculation the forces at work in the various phases of animal and vegetable life. Remember the conflagrations, the furnaces, the fires, and the other manifestations of the terrible energies of the atmospheric oxygen, whenever it is aroused. Do not even forget the comparatively insignificant power which man is wielding with the aid of powder and of steam. Making now an immense allowance for what you must have overlooked, sum this all up, — if you can without bewilderment, — and what part is it of the whole ? Why, it has been calculated that it is equal to but one 2,300,000,000th of the force which the sun is every moment pouring into space. And what is the sun? A small star in the infinitude of space, where shine Sirius and Arcturus, Regulus and Aldebaran, Procyon and Capella, with unnumbered others, all shedding forth a far mightier effluence than our feeble star : yet the grand total of the powers streaming from all the suns which human eye has seen, or which still lie undiscovered in the depths of space, alone represents the active energy of the universe. My friends, there are two theories of causation. One regards this energy as an unintelligent power. The other sees in it simply the will of the Almighty. They are both theories. We cannot substantiate either. But which do you ENERGY APPEARS AS MOTION. 305 think is the more probable? Let us not pass hasty judgment, but soberly weigh all the testimony, and base our decision on the best scientifie evidence we can obtain, and on that alone. Thus far in our discussion we have been dealing with facts and principles which every theory of causation must explain. But we now pass into what is rather the region of speculation, and we must step more cautiously. I have used thus far the terms ^;^^r^and transfer of energy ^v^WhowX. expecting that you would attach to them any more definite meaning than that which is conveyed by the words in their most familiar use. Energy is a definite thing, which is as palpable to our senses as matter, and which, in most cases at least, we can measure as accurately. Any one who has been stunned by a blow, bruised by a fall, burnt by a fire, dazzled by the sun, or paralyzed by a shock of electricity, knows well enough what energy is; and the doctrine of the conservation of energy is wholly independent of any theory which men may entertain in regard to its essence. For this reason, I have aimed to present the grand doctrine of modern science entirely free from all speculations whatsoever ; but now that we are seeking to go behind the external phenomena, it will be well for us to consider very briefly a theory which, although it does not profess to explain what energy is in its essence, nevertheless may give to the mind a more definite conception of its mode of action. The theory, it is true, cannot be regarded as fully established ; but it represents the undoubted tendency of science, 3o6 MOTION OF MOLECULES. and the materialists would, of all others, be the first to accept it. According to the modern view, all energy appears as motion, and this too whether it be manifested in mechanical work, or in the more subtile phenomena of sound, light, heat, chemical affinnity, electricity, or magnetism. We must, however, extend our idea of motion, and not limit it, as is usually done, to the motion of visible masses of matter. Even the smallest material masses perceptible to our senses must be regarded as aggregates of still smaller masses, which we call molecules. These molecules, moreover, even in the densest bodies, cannot be in contact, and we must picture them to our imagination each as a tiny world poised in space. The same relation which the worlds bear to the cosmos, we conceive that these molecules bear to the microcosmos which every mass of matter represents, and it is believed that the motions of suns and systems have their miniature in the motions of these molecules. The ether, also, of which I spoke in the second chapter as filling celestial space, is supposed to pervade equally the molecular spaces, to surround each molecule with a highly elastic atmosphere, and to be the medium by which motion is transmitted throughout a universe which includes the infinitesimal as well as the infinite. Moreover, we conceive that the motion of the molecule is the exact counterpart of the motion of a world or of the motion of a ball, and that all motion obeys the selfsame laws. As when an ivory billiard-ball strikes another, it gives up the whole or a part of its motion to the second ball, so we believe that one molecule may transmit motion to another. In like manner, as an impulse is transmitted through a long line of billiardballs, and the last ball only appears to move, so also we conceive that the electrical impulse is transmitted from molecule to molecule through the telegraph wire, and produces perceptible motion only when transformed into magnetism at the end of a thousand miles. Again, motion may be transmitted from molecules to masses of matter ; for although the impulse imparted by a single molecule may be as nothing, the accumulated effect of millions on millions of these impulses may be immense. In this way, as we conceive, the motions of the ether particles in the sunbeams unite to produce all the grand phenomena of nature. On the other hand, the motion of great masses may be suddenly resolved into the motions of the molecules composing these masses, and thus, when motion outwardly appears to cease, it may only be transferred from the previously moving body to the molecules within. When the cannon-balls, with their immense velocity, strike the iron-clad frigate and fall harmlessly from her armor-plates, the particles of iron take up the motion of the ball, and indicate by a higher temperature that the energy has not been lost. Understanding, then, the term motion in the extended sense just explained, we shall comprehend more clearly the theory stated above. This theory supposes that the phenomena of sound, light, heat, and electricity are produced by the motions of molecules, in the same way that the grander phenomena of mechanics and astronomy are caused by the mo- tion of large masses of matter. The transmission of energy is, then, the direct result of the transmission of motion, and the conservation of energy is fully explained by the well-known law of inertia, which the motions of all matter necessarily obey. I have not time to enter into any details in regard to the mode of motion by which light, heat, and all this class of phenomena are produced, other than those already given in the previous chapters of this book ; but I take great pleasure in referring my readers to the work of Professor Tyndall, already frequently quoted, as by far the best popular statement of the subject that has ever been made. Indeed, great differences of opinion in regard to the mode of the molecular motion are entertained by those who accept the theory in its general statement, and in many cases we can form no conception of the peculiar phase which the motion assumes. It is sufficient for my purpose if I have been able to make clear the general principle, and I will only add a few numerical results, which will show what a precise form the theory has taken in the minds of scientific men. According to the modern theory, when we heat a body we merely impart to its molecules a greater velocity of motion. Now, according to the experiments of Professor Joule, when we raise the temperature of a pound of water two P'ahrenheit degrees, we distribute among the molecules of the liquid an amount of motion equal to that acquired by a weight of two pounds in falling JJl feet; and a simple calculation will show that this is represented by a Minle ball, weighing one-eighteenth of a pound, moving with a velocity of 1,338 feet in a second."^ The amount of motion, therefore, which is imparted to the particles of water in an ordinary tea-kettle during the process of boiling, must be in the aggregate vastly greater than that ever acquired by any projectile. We shall arrive at a still more remarkable result if we examine in the light of our theory the process of chemical combination by which water is formed. In this process of burning, one pound of hydrogen gas combines with eight pounds of oxygen gas to form nine pounds of water. Although the distances which separate the atoms of the two gases before combination are utterly inappreciable by our senses, yet, in passing over these distances, they acquire a velocity which causes them to clash together with tremendous energy, and in the collision this form of atomic motion is transmuted into that other mode of motion which we call heat. Incredible as it may appear, the amount of motion which in the act of combination alone is thus transmuted into heat corresponds to the fall of a ton weight down a precipice 22,320 feet high. ,Such illustrations might be multiplied indefinitely ; but you will see from these how purely mechanical the idea is which we associate with the motion of a molecule, and you must have been impressed by the magnitude of the energy which these molecular motions represent. " I have seen,'' says Professor 310 CAUSE OF MOTION. Tyndall, " the wild stone avalanches of the Alps, which smoke and thunder down the declivities with a vehemence almost sufficient to stun the observer. I have also seen snow-flakes descending so softly as not to hurt the fragile spangles of which they were composed ; yet to produce from aqueous vapor a quantity of that tender material which a child could carry, demands an exertion of energy competent to gather up the shattered blocks of the largest stone avalanche I have ever seen, and pitch them to twice the height from which they fell.'* If such, then, be the measure of these atomic motions, we can easily conceive how the motion of the cannon-ball might be transferred to the particles of the armor-plate without much apparent result, and even how the energy of a world might be maintained by the motion of the molecules in the sunbeam. Accepting, then, this new theory of science, and admitting that all energy is manifested in motion, we reduce at once our discussion of the doctrine of causation to this simple question, — What is the primary cause of motion ? If we can explain the simplest case of motion, we have solved the problem for the universe. Take, for example, a boys ball, moving through the air under the impulse of a welldirected blow. Do we not know something of the cause of that motion ? Is it not connected with the muscular contraction of the boy's arm, produced by his will ? Is not his volition, acting mysteriously on matter, at least the occasion of the motion? It is perfectly true that the will does not create the motion. The ball is impelled by a portion of that THEORY OF CAUSATION. 3II energy in nature which man can neither increase nor diminish. But still the boy's will is the occasion of the motion. It has opened the channel through which the energy of. nature has flowed to produce the specific result which the boy desired. So, in a thousand other ways, man is able to come down, as it were, upon nature, and to introduce a new condition into the chain of causation. Place the point of contact as far back as you please, theorize about the subject as you may, the fact still remains the same. Our will does act on matter, and does act to produce most efificient results. Here is energy exerted of whose cause we have the consciousness within ourselves, and, if the analogy is worth anything, it points to but one conclusion, — namely, that motion is always the manifestation of will. As the boy's will acted on that particle of matter, which, though moved perhaps but an atom's breadth from its position, set in action — as if by the touching of a spring — the train of natural' causes which gave motion to the ball, so we may suppose that the Divine will acts in nature. According to this view, the energy which sustains the universe is the will of God, and the law of conservation is only the manifestation of His immutable being, — '^ the same yesterday, and to-day, and forever." We do not say that this theory can be proved — for certainty here is out of the question — but we do claim that it is based on the only analogy which nature affords, that it is a legitimate deduction of science, and that it is perfectly consistent with Christian faith. On a subject where science can only 312 RELATIVE LIMITATIONS. grope, the wildest theories are possible ; but these should not trouble a well-balanced mind, so long as there exists an equally probable theory which can be reconciled with the purest faith. It has been my aim in this chapter to show, not only that such a theory is tenable, but also that the Christian theory of causation is the most probable theory of science ; and my earnest hope is, that, for some minds at least, the considerations I have offered will help to reconcile the apparent conflict between science and religion which materialism is ever striving to foment. Allow me to add, in concluding, one or two other suggestions which may be of value in the same direction. I cannot but believe that the appearance of clashing between science and religion would be wholly avoided, if the teachers both of God's unwritten and of His written word would pay more regard to the necessary limitations of scientific and religious thought. On subjects where the methods of acquiring knowledge are so utterly unlike, where the relations of knowledge to the human understanding are so different, it is in vain to expect literal accordance. Science, both in its methods and its results, addresses the understanding exclusively ; Christianity appeals chiefly to the heart. Science aims to instruct ; Christianity aims to persuade. Science is attained by study, and is possible only for the few ; Christianity is a free gift from God to all men who will receive His Son. The results of science are fully comprehended, and can be expressed in definite terms ; the truths of Christianity stand on a level METHOD OF SCIENCE. 313 above man's intellect, and can only be shadowed forth in types and symbols. The forms of science are constantly changing ; the types and symbols of Christianity are permanent. Lastly, while the language of science may be so varied from time to time as to express accurately the current ideas, Christianity necessarily retains the forms through which it w^as first revealed. Under such conditions, how can it be expected that the letter of revelation should agree with the language of science ? One might as reasonably find fault with nature because its crystals are not perfect, as criticise the Bible because its language, although embodying divine truth, is not free from the necessary limitations and imperfections of the human medium of thought. Consider in this connection the method of science which we have already discussed at some length in a previous chapter. Remember that in nature we observe only a sequence of phenomena. The idea of a cause is supplied by our own minds, and every phenomenon is so surrounded and obscured by adventitious circumstances that it is frequently very difficult to establish the causal connection with the antecedents. Science endeavors to discover this connection by a process of elimination, which it conducts in various ways. It notices, for example, that while certain antecedents invariably accompany a given effect, others are sometimes absent, and in this way the accidental concomitants may be to a greater or less extent eliminated. The process of elimination is more rapid and satisfactory when the phenomenon is so far under our control that we can vary the 314 THE RADIOMETER. conditions by experiment. If, then, we find that a given condition may be omitted or varied without influencing the result, we can conclude with great safety that this antecedent is not essential. On the other hand, if we find, either from experiment or observation, that the effect varies with the condition, any change in the antecedent being followed by a corresponding change in the phenomenon we are studying, then we feel great confidence that we have found one at least of the causes we are seeking. When a connection of this kind is established, the effect is said to be a function of its antecedent, and it is frequently possible to express this function by a mathematical formula, so that we can predict with absolute certainty the nature and extent of the effect which will under any given circumstances be produced; and in this case our certainty in regard to the immediate cause of the phenomenon is of the highest order which can be reached in science. An illustration will make the point clearer. A few years ago. Professor Crookes, of London, having observed that light pith balls delicately suspended in a vacuous tube were under certain conditions repelled by the sun's rays, was led on from step to step until he had constructed the instrument now so well known as the radiometer, in which a delicate wheel is rapidly turned by the rays of the sun, or by the rays of any source of bright light, shining on its blackened vanes. At first sight the effect seemed to be the result of a direct mechanical action of the rays of light, and this explanation was for a time generally received. But it soon appeared that if the he^t-givi^fe/rays'"/ ,^ were absorbed by passing the beam of light throt^gh ^ }a solution of alum, the motion of the vanes was ar^/ \ . rested, or at least very greatly retarded, while, on the f^i other hand, when the light-giving rays were absorbed by a solution of iodine, a medium which although "^ opaque to light is pervious to heat, the motion was maintained with nearly its full activity. Further, it was soon found that the motion could be produced by any cause which determined a slight difference of temperature between the blackened faces of the vanes and the surface of the inclosing glass bulb, and that while the motion was in one direction when the vanes were warmer than the glass, the motion was in the opposite direction when these conditions were reversed ; and further, that, other things being equal, the greater the difference of temperature the more rapid was the motion. Hence, after a long series of experiments, it was concluded that the motion of the radiometer was an effect of a difference of temperature between its parts, or, in other words, that the radiometer is, like the steam engine, simply an example of a heat engine. Thus Professor Crookes was able to discover the proximate cause of the remarkable phenomenon he had observed, and having done this he had learned all that could be known with certainty in regard to it. This example is a fair illustration of the method of science, and scientific ability is shown in the power of so directing observations or making experiments as to establish the true causal relations in any case. No one supposes, however, that having 3l6 MOLECULAR THEORY. established this relation we have discovered an " efficient cause." We have found out which are essential and which are accidental antecedents, and established possibly what we may call the law of succession, but nothing more. There may be a whole chain of such antecedents — we frequently know that there is — and, behind all, the true cause as much concealed as ever. The mind, moreover, refuses to stop at this point, or to rest satisfied with such a result. It at once begins to theorize. Why is it that a difference of temperature causes the steam engine to work, or the radiometer wheel of our illustration to turn ? We cannot answer the question with certainty, but this is our theory : " Heat is a mode of motion,'* and its phenomena are the effects of the motion of molecules of matter. Molecules, although of an order of magnitude far removed from our limits of perception, are as real masses as cannon-balls or bullets, and their motions as rapid and as real, and although the moving power of single molecules is as nothing, yet collectively their motion is capable of producing effects compared with which the mightiest bombardment is insignificant. Now, although the air has been exhausted to a very high degree from the bulb of the radiometer, the interior still contains a vast number of molecules of gas, which, unless our calculations are greatly at fault, must be counted by the million miUion for every cubic inch of capacity. Moreover, at the degree of exhaustion reached in the bulb, the amplitude of the motion of the little masses becomes SO considerable that they bound to and fro between the vanes of the wheel and the surface of the inclosing glass, and according to our theory the motion of the wheel is the result of this reaction. This theory is supported by the fact that if we exhaust the air from the bulb of the instrument beyond a certain limit we arrest the motion. It is also true, however, that the motion stops if the amount of air be only slightly increased, for the evident reason that there is then less free room for the motion of the separate molecules, and they do not move far enough to cause any reaction between the wheel and the surrounding walls. To those who have become familiar with the conception of molecular magnitudes this theory is very plausible. If you ask whether the theory is true, I can only answer that we may perhaps regard it as relatively true, seeing that it has explained a great many facts and suggested lines of investigation which have led to new discoveries. But it certainly is not absolutely true in the sense of expressing the whole truth. These molecules are creatures of the scientific imagination, and may be mere fictions, but the value . of the theory lies in its power of directing research, and, as I have before said, I believe that all theories which have this power are partial truths; but no one can regard them as perfect representations of the realities of nature. Men who, in the first flush of discovery, feel the guiding power of a theory, are wont to associate with it an undue reality, but they soon learn their error by experience. guide in chemical investigation. The chemist is acquainted with numerous groups of substances which we call isomeric compounds, and two substances are said to be isomeric when they not only consist of the same elements united in the same proportions, but also have the same density in the state of vapor, so that according to the molecular theory their molecules must have the same weight. For example, the two substances called butyric acid and acetic ether are isomeric bodies. The vapor density, as we call it, of both substances is fortyfour times that of hydrogen, and they both consist of carbon, hydrogen, and oxygen united in precisely the same proportions, yet the two substances differ from each other in their properties most widely. It does not boil until the temperature reaches 302° on our Fahrenheit scale, and does not readily inflame. Acetic ether, on the other hand, is a limpid liquid with a pleasant fruity smell, highly volatile, boiling at 165'^, and inflaming with the greatest ease. What, now, is the cause of this most marked difference? The phenomenon demands an explanation, and invites theorizing, and the theory we have formed is as follows : The molecules of all compound substances are themselves groups of elementary atoms, and the molecules of two isomeric compounds, Hke butyric acid and acetic ether, although consisting of the STRUCTURAL SYMBOLS. 319 same number of the same atoms, and therefore having the same weight, differ from each other in that these atoms are differently grouped. Nay, we go much further than this, for we have formed a scheme of the manner in which the atoms are grouped in each case, thus : Butyric Acid. Acetic Ether. In these diagrams the capitals stand for atoms of the elementary substances of whose names they are the initial letters, and it is obvious that not only two isomeric compounds, but a great number, might be formed by differently grouping these same atoms ; although the number of possible combinations is greatly diminished by conditions imposed by wellknown chemical principles, which it would be out of place to discuss in this connection. Our diagrams, moreover, indicate a great deal more than the general theory, that the differences between isomeric compounds depend on differences in the grouping of the same atoms ; for the exact grouping in each case is based on the known chemical relations of the substances. There is a reason for the position of each letter in these structural symbols, as they are called. 320 WORKING THEORIES. of the theory of molecular structure which is the basis of modern theoretical chemistry. It is the chief object of chemical investigation at the present time to discover the molecular structure of chemical compounds, and there is frequently as earnest discussion about the position of a letter in one of these structural symbols as there is in natural history about the origin of species ; and if there were a point of theological doctrine involved in the controversy, the discussion w^ould be doubtless as personal and as bitter. Yet no one in his sober senses dreams that these diagrams represent realities. If there are such things as atoms and molecules, all analogy would lead us to believe that the parts must sustain relations to the whole similar to those of the members of the solar system, and like the sun and planets must have their orbits and periods of revolution. Still our diagrams give us correct representations of the relations between a large number of facts which they serve to group together, and this theory of molecular structure has been one of the most successful aids in directing investigation which science has known. It has led to the discovery of a process of manufacturing artificially the valuable madder dye called alizarine — a discovery which has revolutionized one of the most important industries of the world — and this is but one of hundreds of new discoveries with which it has enriched the arts of life or extended chemical science. In a word, it has been a most valuable "working theory," and no other theory except the law of gravitation can be compared with it in efficiency. Hence, absurd as our conceptions of molecular structure certainly would be, if we supposed them realized in the crude forms which our diagrams suggest, yet we cannot but regard these representations as the rude symbols of a real truth which in its essence transcends the limits of our present knowledge. That which is true of the molecular theory of modern chemistry is equally true of the two great conceptions which are always cited as examples of the most perfect theories of physical science. The undulatory theory of light involves assumptions in regard to the alleged ether which are simply preposterous, and even the law of gravitation takes for granted action at a distance which is opposed to all experience and to all philosophical thought. Still, to abandon these theories, because we cannot accept their postulates, would be as foolish as to throw away our compass because we cannot agree about the theory of magnetism. Now we are told by the naturalists that Darwinism is just such another working theory, and they are, with reason, impatient when blamed for following its guidance because it cannot be reconciled with certain cherished theological dogmas. And, assuming that the dogmas are right, you might as reasonably find fault with the mariner for using the magnetic needle, because it does not always point to the true north. Like the needle, our theory points out the path of discovery, and, although the way may at times seem to lead backward, and men, like Columbus, may become frightened at the evident aberrations of their guide, 14* 322 DOGMATISM IN SCIENCE. yet if, with the brave navigator, they persevere, the trusted guide will certainly conduct them to the true goal in the end, unless truth is a fiction, and the whole issue of the human faculties a lie. Nevertheless there may be as blind dogmatism in science as has ever existed in theology, and it is dogmatism when men claim as absolute certainty what is at most merely relative truth, and treat with superciliousness all who do not accept their authority as final. Certainly, let us be true to our convictions, and hold fast to our theories as the earthen vessels which contain a precious treasure, but let us remember, And thou, O Lord, art more than they. Such, then, being the credentials, and such the methods of science, let us turn for a few moments to the credentials and methods of theology, and ask, in all humility, whether the conditions do not impose limits on human thought in this direction as well as in the other. In theology, as in science, there are certain facts which, although chiefly facts of consciousness, and not facts of observation, are no less facts than the phenomena of nature. Prominent among these facts are the moral judgments, the affections, and the aspirations of the soul, which, explain them as you will, are the most important factors of human life — the most potent agents in human society. Corresponding to these affections and aspirations are certain religious beliefs which we THEOLOGICAL DATA. 323 have inherited from our ancestors, and which have come down to us with the authority of eighteen centuries of human experience. During that period these beHefs have satisfied the highest aspirations of humanity, and have led many of the purest and noblest men whom the world has known to encounter peril, endure cruel torments, and suffer ignominious death, in attestation of their faith. The origin of this faith was a life which, as portrayed to us in the Gospels, has aroused in every generation of men from its birth the noblest enthusiasm and the warmest love ; a life which has appeared more and more transcendent as civilization has advanced, and which has been the one power that has redeemed man from his selfishness, and enthroned charity among the chief rulers of the earth. Such, then, are the credentials of Christianity — a real want, an adequate satisfaction. Learned men have endeavored to formulate the principles of religious beliefs, and hence have come systems of theology, in regard to which we might repeat very nearly the same statements that we have already made in regard to the theories of science. These systems have certainly satisfied the great mass of mankind, and have done a good work in defining and preserving the faith ; but they are all earthen vessels, and, like the working theories Let us remember that as Christianity was revealed in a life, it ever abides as a life in the heart of the believer, and only those who have lived that life can 324 METHODS OF THEOLOGY. know how real it is. To all such, however, it is the most real thing in the world, and the theological forms in which it finds expression have the same reason for their being as the forms of science, and are held the more sacred as the truths symbolized are the more dearly cherished. Moreover, it is a fact most worthy of notice, that Christianity is almost co-extensive with civilization, or, as Coleridge has expressed it, " Christendom is the best evidence of Christianity." While, however, the "internal evidences" of Christianity, which we may not inappropriately call the credentials of theology, are so similar to the credentials of physical science, the methods of theology are, for the most part, utterly unlike the scientific methods we have been discussing. In the first place, the very data on which the whole body of Christian theology rests cannot be verified by observation. The phenomena of nature are ever with us, and can be closely scrutinized at each repetition ; but the events from which Christianity arose occurred once for all more than eighteen centuries ago ; and if we take the summary of those events given in the primitive creeds as representing what is common to the beliefs of the great body of Christians, and as authenticated by the experience of the Church, and present this as the subject-matter of theology, we must claim belief in these data on grounds of faith, and not on scientific evidence. We accept these supernatural facts not solely on account of the historical evidence adduced in fheir support, but largely in deference to a certain "witness in our hearts," which disposes us to accept them. To men who know nothing by experience of this inner witness, behefs thus accredited may appear foolishness, and this is too often the case with those who, occupied exclusively with the study of nature, are not accustomed to accept any statement as true which cannot be verified by experiment or observation, and who regard the order of nature as the one standard from which there is no appeal. On the other hand, those who have felt its power are persuaded that the witness in themselves is the voice of God speaking to the heart. The basis thus established. Christian theology is built up on the textual criticism, interpretation and collation of a written record, a form of study which involves historical research, critical analysis, philological investigation, and metaphysical inquiries. Thus a great mass of learning has been accumulated to which various minds will attach very different degrees of value, according as they are more or less familiar with the methods employed. These, however, are so unlike the methods of physical science that it would be the height of presumption for a physicist to pass any judgment on the results. But certainly no one can claim for them a greater value than for the best working theories of science. Seeing, then, that the limits of positive knowledge are so well defined, both in natural science and in theology, we certainly need not be troubled by the apparent conflict between the two modes of thought, so long as the controversy is confined to the debatable ground which has not been fully explored by either party. Within the well-explored limits there never has been and never can be any actual disagreement, and something has been gained if we have been able to make evident that such limits exist, however imperfectly we have succeeded in defining them. The bearing of such considerations is obvious, and they lead to important practical conclusions. In the first place, they should teach men of science to honor and reverence the forms of religion. They are the types and symbols of a truth higher than any which Science can teach. Let Science vindicate her own methods, and allow no interference within her proper sphere ; but unless she learn that there are other sources of knowledge than material nature, and other channels of truth than the intellect, her own philosophy will be confounded, and her light will go out in darkness. On the other hand, it is equally the duty of the ministers of religion to honor and respect the methods of science. They have been ordained by God, and through these processes of thought He is constantly revealing eternal truths to the mind of man. Insist as strongly as you please that Science should be allowed no voice in matters of faith. Scrutinize as closely as you can every step of her logic ; but so long as she keeps within her legitimate province, allow her the largest liberty, and extend to her the most generous encouragement. Watch sharply her results, and expose her fallacies wherever you can find them ; but if your judgment condemns, let it be on scientific grounds, and not by any arbitrary standard of your own. Above all, even if you think your most cherished SCIENTIFIC AND RELIGIOUS THOUGHT. 327 Opinions are in danger, do not withdraw your fellowship hastily, or be betrayed into undiscriminating censure. Science is paramount within her own province. Do everything in your power to consecrate her aims and sanctify her spirit, but do not attempt to control her investigations or restrict her free thought. Await God's time. If Science be wrong, she will sooner or later correct her error. If she be right, the ^ Lord of Hosts " is on her side, and you will find yourself " fighting against God." Again, a proper appreciation of the necessary limits of scientific and religious thought should lead all men to reverence the * Word of God " as it has been handed down to us through history. In view of the facts already intimated, I cannot look with favor on any attempts at Biblical criticism which aim to square the language of Scripture with the results of modern science. They leave a most unpleasant impression on my mind. Seeing the large element of human ignorance, incapacity, and frailty, which the history of both so conspicuously exhibit, I cannot stake my faith either on the ^* Infallibility of the Church " or the ' Infallibility of the Book." But I do believe that the Bible is inspired with spiritual truth, from the «grand epic of creation, with which it opens, to the glorious vision of the New Jerusalem at its close. I feel that its very words are consecrated by the associations of the ages, and if you are so ready to accommodate any part of them to the shifting phases of science, what certainty can I have in regard to the whole? The Bible is no text-book of science, and the attempt to impose an equivocal or mysterious meaning on its simple and obvious statements degrades and dishonors it in the minds of devout men. The methods by which its truths are expressed may be at times rough and uncouth ; but they are the methods chosen by God, consecrated by the blood of martyrs, and hallowed by the tears of saints; and they have therefore a power which no other language could have. Break not the mould in which the forms of faith have been cast, before they have become firm and hard, lest the precious metal should itself be lost. Finally, leave religion and science to their respective methods, and encourage both alike in their noble callings. Let science, by cultivating man's intellect, elevate him to nobler and more spiritual views of God's wisdom and power. Let religion, by purifying man's heart, open to him clearer visions of God's purity and love; and, at last, when this material shall have vanished, and when the waters of controversy shall have ceased to roll, the heart and the intellect, made one and washed clean in the blood of the Lamb, shall unite in the song of the angels around the throne, saying, " Blessing, and glory, and wisdom, and thanksgiving, and honor, and power, and might, be unto our God for ever and ever." But while insisting upon the necessary limitations of scientific and religious thought, I must not forget that all such considerations bear with peculiar force upon the questions I have discussed in this book. Therefore, although I have most carefully endeavored to guard my argument from the slighest exaggeration, I should not feel justified in concluding without distinctly stating how far, in my opinion, the argument of natural theology may be safely carried, and to what extent unaided science may be said really to prove the fundamental truths of Christianity. In the first place, then, I believe that the existence of an intelligent Author of nature, infinite in wisdom and absolute in power, may be proved from the phenomena of the material world with as much certainty as can be any theory of science. In the second place, I am of opinion that the facts of nature are throughout consistent with the belief that the Author of nature is a personal being, and the one only and true God revealed to us in the Bible. Lastly, I think that the relations of the human mind to the material world, viewed in the light of modern science, give us strong reason to believe, on scientific grounds alone, that the universe is still sustained in all its parts by the same omnipotent and omniscient Will which first called it into being. To the extent I have indicated, I regard the argument of natural theology as logically valid. Moreover, I am persuaded that science confirms and illustrates the priceless truth which Christ came on earth to reveal ; but I do not believe that the unaided intellect of man could ever have been assured of even the least of these truths independently of revelation. And, as I stated in my introductory chapter, I feel that the best service which science can render to religion is in the way of confirmation and illustration, rather than in that of absolute proof, and for this reason I have preferred to discuss my subject chiefly from that point of view. The subject, as prescribed by the founder of the " Graham Lectures," ^ was '' The power, wisdom, and goodness of God as manifested in His works," and to this form of statement, if interpreted in the sense just indicated, I have nothing to object. I do not beheve, however, in any sense, that nature proves the goodness of God. When the heart has been once touched by the love of God, as manifested on Calvary, the tokens of God's goodness are visible everywhere ; but before this, nature, to one who has seen its terrors and felt its power, looks dark indeed ; and the pretence that the material universe, unexplained by revelation, manifests a God of unmixed beneficence, not only does harm to religion, but places science in a false light. The most superficial observation shows that this is not true. Lightning and tempest, plague, pestilence, and famine, with all their awful accompaniments, are no less facts of nature than the golden sunset, the summer's breeze, and the ripening harvest ; and who does not " know that the whole creation groaneth and travaileth in pain together until now"? It does not change the terrible fact to say that nature has been disordered by man's sin ; for sin is itself the greatest evil in the world, and its ghastly forms meet us at every step. So prominent, indeed, is the evil in nature, and so insidiously and mysteriously does it pervade the whole system, that an argument to prove the malignity of God could be made to appear quite as plausible as the arguments which are frequently CONCLUSION. 331 urged to prove His pure beneficence ; and when the unaided human intellect has attempted to make to itself a beneficent God, it has usually made a malignant deity as well. Nature seems to manifest God's wrath no less than His love, and it is a false and sickly philosophy which attempts to keep the awful fact out of sight. God is our Father ; but nature could not teach it, and * the Word was made flesh " to declare it. God is love ; but nature could not prove it, and the Lamb was " slain from the foundation of the world" to attest it. Nature is but a part of God's system, and not until the natural and the supernatural shall be made one will the mystery of evil be solved.	115,826	common-pile/pre_1929_books_filtered	chemistrreligion00cookrich	public_library	public_library_1929_dolma-0011.json.gz:3137	https://archive.org/download/chemistrreligion00cookrich/chemistrreligion00cookrich_djvu.txt
gP9bWVVLcZzQyAMj	The Big Sea	II: Big Sea Washington Society Besides the quarter, I landed with a few poems. I took them that afternoon to show to Countee Cullen, whose work I admired. Cullen told me the National Association for the Advancement of Colored People was having a benefit cabaret party that night at Happy Rhone’s Club on Lenox Avenue. So I went—and got in free, being a writer for the Crisis. It was a very gay and very crowded party, sprinkled with celebrities. Alberta Hunter was singing a song about, “Everybody loves my baby, but my baby don’t love nobody but me.” At the door I met Walter White and he introduced me to Mary White Ovington, James Weldon Johnson, and Carl Van Vechten. I sat at a table with Walter’s charming and very beautiful wife, and I was properly dazed. She looked like a Moorish princess. I wanted to ask her for a dance, but I still had my sea-legs on. Besides, I was bashful. All the Crisis people were at the party and I asked if they had liked my article and they said: “Yes.” They told me their office had cabled me twenty dollars to Genoa. But the cable came back. The next day they showed me the cable receipt, and the date indicated that it reached the Albergo Populare the day after I sailed. I was glad it had missed me, because now I had twenty dollars to start life anew in my New World, like an immigrant from Europe. So I went to see Jeanne Eagels in Rain, and then What Price Glory, before I went home. My mother and kid brother were in Washington. This time, she wrote, she and my step-father had separated for good, and she had decided to come to Washington to live with our cousins there, who belonged to the more intellectual and high-class branch of our family, being direct descendants of Congressman John M. Langston. She asked me to join her. It all sounded risky to me, but I decided to try it. My cousins extended a cordial invitation to come and share their life with them. They were proud of my poems, they said, and would be pleased to have a writer in the house. By now, I wanted to go back to college, anyhow. And I thought that Howard, in Washington, would be a good place to start, if I could manage to get together the tuition. So I bought a ticket to Washington. The twenty dollars from the Crisis would not cover both a ticket and an overcoat, which I needed, so I arrived in Washington with only a sailor’s peajacket protecting me from the winter winds. All my shirts were ragged and my trousers frayed. I am sure I did not look like a distinguished poet, when I walked up to my cousin’s porch in Washington’s Negro society section, LeDroit Park, next door to the famous colored surgeon and heart specialist, Dr. Carson. Listen, everybody! Never go to live with relatives if you’re broke! That is an error. My cousins introduced me as just back from Europe, but they didn’t say I came by chipping decks on a freight ship—which seemed to me an essential explanation. The nice, cultured colored people I met in Washington seemed to think that by just being a poet I could get a dignified job, such as a page boy in the Library of Congress. I thought such a job would be nice, too, so they sent me to see Mary Church Terrell and some other famous Negro leaders who had political influence. But to be a page boy in the Library of Congress seems to require a tremendous list of qualifications and influential connections, and a great capacity for calling on politicians and race leaders, as well as a vast patience for waiting and waiting. So, being broke, I finally got a job in a wet wash laundry instead. I had to help unload the wagons, and open the big bags of dirty clothes people send to wet wash laundries. Then I had to sort out and pin the clothes together with numbered pins so that, once washed, they could be reassembled again. I never dreamed human beings sent such dirty clothes to a laundry. But I knew that, as a rule, only very poor people use wet wash laundries. And very poor people cannot afford to be changing clothes every day. Nor every week, either, I guess, from the look of those I handled. Cultured Washington, I mean cultured colored Washington, who read my poems in the Crisis, did not find it fitting and proper that a poet should work in a wet wash laundry. Still, they did nothing much about it. And since none of them had any better jobs to offer me, I stayed there. The laundry at least paid twelve dollars a week. I spoke with Dean Kelly Miller at Howard University about the possibility of trying for a scholarship at the college. And he spoke grandiloquently about my granduncle, who had been the first Dean of the Howard Law School, and what a fine man he was. But it seems that there were no scholarships forthcoming. I spoke with Dr. Alain Locke, who said my poems were about to appear in the New Negro Issue of the Survey Graphic, and who declared I was the most racial of the New Negro poets. But he didn’t have any scholarship up his sleeve, either. So I began to try to save a dollar a week toward entering college. But if you ever started out with nothing, maybe you know how hard it is to work up even to an overcoat. I wanted to return to college mostly in order to get a better background for writing and for understanding the world. I wanted to study sociology and history and psychology, and find out why countries and people were the kind of countries and people they are. Somebody lent me This Believing World, which I put on the sorting table at the laundry and read between bundles of wet wash. Comparative religions interested me, but I didn’t believe the end of This Believing World was necessarily true. One day my mother came to the laundry, crying. She said she couldn’t stay at our cousin’s house a minute longer, not one minute! It seems that in some way they had hurt both her pride and her feelings. We located two small rooms on the second floor in an old brick house not far from where I worked. The rooms were furnished, but they had no heat in them, so we bought a second-hand oil stove, which we had to take turns using, carrying it back and forth between my room and my mother’s room, since we couldn’t afford two oil stoves that winter. My little brother, Kit, was in school then and could kick out a pair of shoes as fast as any boy his age in America. My mother worked in service, but wages were very low in Washington. So, together, we made barely enough to get along. Hard as I tried, I could not save a dollar a week to go to college. I could not even save enough to buy a heavy coat. Folks! Start out with nothing sometime and see how long it takes to work up to something. I felt very bad in Washington that winter, so I wrote a great many poems. (I wrote only a few poems in Paris, because I had had such a good time there.) But in Washington I didn’t have a good time. I didn’t like my job, and I didn’t know what was going to happen to me, and I was cold and half-hungry, so I wrote a great many poems. I began to write poems in the manner of the Negro blues and the spirituals. Seventh Street in Washington was the nearest thing I had known to the South up to that time, never having been in Dixie proper. But Washington is like the South. It has all the prejudices and Jim Crow customs of any Southern town, except that there are no Jim Crow sections on the street cars. Negro life in Washington is definitely a ghetto life and only in the Negro sections of the city may colored people attend theaters, eat a meal, or drink a Coca-Cola. Strangely undemocratic doings take place in the shadow of “the world’s greatest democracy.” In Europe and in Mexico I have lived with white people, worked and eaten and slept with white people, and no one seemed any the worse for it. In New York I have sat beside white people in theaters and movie houses and neither they nor I appeared to suffer. But in Washington I could not see a legitimate stage show, because the theaters would not sell Negroes a ticket. I could not get a cup of coffee on a cold day anywhere within sight of the Capitol, because no “white” restaurant would serve a Negro. I could not see the new motion pictures, because they did not play in the Negro houses. I asked some of the leading Washington Negroes about this, and they loftily said that they had their own society and their own culture—so I looked around to see what that was like. To me it did not seem good, for the “better class” Washington colored people, as they called themselves, drew rigid class and color lines within the race against Negroes who worked with their hands, or who were dark in complexion and had no degrees from colleges. These upper class colored people consisted largely of government workers, professors and teachers, doctors, lawyers, and resident politicians. They were on the whole as unbearable and snobbish a group of people as I have ever come in contact with anywhere. They lived in comfortable homes, had fine cars, played bridge, drank Scotch, gave exclusive “formal” parties, and dressed well, but seemed to me altogether lacking in real culture, kindness, or good common sense. Lots of them held degrees from colleges like Harvard and Dartmouth and Columbia and Radcliffe and Smith, but God knows what they had learned there. They had all the manners and airs of reactionary, ill-bred nouveaux riches—except that they were not really rich. Just middle class. And many of them had less fortunate brothers or cousins working as red caps and porters—so near was their society standing to that of the poorest Negro. (Their snobbishness was so precarious, that I suppose for that very reason it had to be doubly reinforced.) To seem people of culture, they performed in an amazing fashion. Perhaps, because I was very young and easily hurt, I remember so well some of the things that happened to me. When Dr. Locke’s fine collection of articles, stories, pictures, and poems by and about Negroes was published, The New Negro, Washington’s leading colored literary club, decided to honor the “New Negro” writers by inviting them to their annual dinner, a very “formal” event in the city. To represent the younger poets, they invited Countee Cullen and me. Mr. Cullen wrote from New York that he accepted the invitation. I dropped them a note saying that I could not come, because, among other reasons, I had no dinner clothes to wear to a formal dinner. They assured me that in such a case I could attend their dinner without dinner clothes—just so I would read some of my poems. They also stated that their invitation included my mother, who, they knew, would be proud to see me so honored. I did not want to go to the dinner, but finally I agreed. On the evening of the dinner, however, I came home from work to find my mother in tears. She had left her job early to get ready to go with me. But about five o’clock, one of the ladies of the committee had telephoned her to say that, after all, she didn’t feel it wise for her to come—since was to be a formal dinner, and perhaps my mother did not possess an evening gown. We didn’t go. Again, some months later, at the home of a prominent hostess, at a supper for Roland Hayes after his first big Washington concert, I was placed near the end of the table. The lady next to me kept her back turned all the time, talking up the table in the direction of Mr. Hayes. A few days later, however, (amusingly enough) I got a note from this lady, saying she was extremely sorry she hadn’t known she was sitting next to Langston Hughes, the poet, because we could have talked together! One of the things that amused me in Washington, though, was that with all their conventional-mindedness, a number of the families in the best colored society made proud boast of being directly descended from the leading Southern white families, “on the colored side”—which, of course, meant the illegitimate side. From all this pretentiousness Seventh Street was a sweet relief. Seventh Street is the long, old, dirty street, where the ordinary Negroes hang out, folks with practically no family tree at all, folks who draw no color line between mulattoes and deep dark-browns, folks who work hard for a living with their hands. On Seventh Street in 1924 they played the blues, ate watermelon, barbecue, and fish sandwiches, shot pool, told tall tales, looked at the dome of the Capitol and laughed out loud. I listened to their blues: Did you ever dream lucky— Wake up cold in hand? I tried to write poems like the songs they sang on Seventh Street—gay songs, because you had to be gay or die; sad songs, because you couldn’t help being sad sometimes. Their songs—those of Seventh Street—had the pulse-beat of the people who keep on going. Like the waves of the sea coming one after another, always one after another, like the earth moving around the sun, night, day—night, day—night, day—forever, so is the undertow of black music with its rhythm that never betrays you, its strength like the beat of the human heart, its humor, and its rooted power. I’m goin’ down to de railroad, baby, Lay ma head on de track. I liked the barrel houses of Seventh Street, the shouting churches, and the songs. They were warm and kind and didn’t care whether you had an overcoat or not. In one of the little churches one night I saw something that reminded me of my own unfortunate “conversion.” A revival had been going full swing since early evening. It was now nearing one o’clock. All the other sinners by now had been brought to Jesus, but this fellow looked distinctly as if he had fallen asleep. It was a Sanctified Church, so the Saints came and gathered around the prostrate soul in prayer. They prayed and prayed and they sang and sang. But some of the less devout, as the hour grew late, had to get up and go home, leaving the unsaved soul for another day. Others prayed on. Still the man did not rise. He was resting easy. Neither prayer nor song moved him until, finally, one old lady bent down, shook him, and said sternly: “Brother! You get up—’cause de Saints is gettin’ tired!”	3,326	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/thebigsea/chapter/washington-society/	pressbooks	pressbooks-0000.json.gz:90965	https://pressbooks.library.torontomu.ca/thebigsea/chapter/washington-society/
okR27d5lpWr_6wZz	26.6: Amino Acid Analysis of Peptides	26.6: Amino Acid Analysis of Peptides - - Last updated - Save as PDF - Steven Farmer, Dietmar Kennepohl, & R Balaji Rao - University of Illinois Springfield Objectives After completing this section, you should be able to describe, briefly, how the identity and amounts of each amino acid residue present in a peptide of unknown structure may be determined. Key Terms Make certain that you can define, and use in context, the key term below. - amino acid analyzer Study Notes You need not memorize the reaction between ninhydrin and an α ‑amino acid. Ion-exchange chromatography When a protein is to be analysed, it is first heated with acid to hydrolyse all the peptide bonds. When such a mixture of amino acids is to be purified and estimated quantitatively, ion-exchange chromatography is the technique of choice. Fully automated amino acid analyzers are now available, which are equipped with a solvent pump to deliver the required buffer(s) in a programmed manner. There is a column, filled with Dowex 50 resin (Fig 26.5.1). This solid support is made up of polymeric beads. Chemically speaking they are polymers bearing arylsulfonic acid groups. The cation exchange resin helps in the separation of amino acids. In a typical run (Fig 26.5.2), the eluent is a buffer. The pH value of the buffer could be varied as step elution or as gradient elution. The chromatogram shown in Fig 26.5.2 is a chromatogram run with gradient elution technique, using ninhydrin as the post column treatment. The detector is a UV detector scanning the wavelengths 570 nm and 440 nm. Fig 26.5.1: A Cation Rasin like Dowex 50 is a polymeric bead bearing aryl sulfonic acid groups Fig 26.5.2: Some typical chromatograms from an amino acid analyzer The Ninhydrin Reaction Alpha-amino acids show reactivity at their the carboxylic acid and amine sites typical of those functional groups. In addition to these common reactions of amines and carboxylic acids, common alpha-amino acids, except proline, undergo a unique reaction with the triketohydrindene hydrate known as ninhydrin. Among the products of this unusual reaction (shown on the left below) is a purple colored imino derivative, which provides as a useful color test for these amino acids, most of which are colorless. A common application of the ninhydrin test is the visualization of amino acids in paper chromatography. As shown in the graphic on the right, samples of amino acids or mixtures thereof are applied along a line near the bottom of a rectangular sheet of paper (the baseline). The bottom edge of the paper is immersed in an aqueous buffer, and this liquid climbs slowly toward the top edge. As the solvent front passes the sample spots, the compounds in each sample are carried along at a rate which is characteristic of their functionality, size and interaction with the cellulose matrix of the paper. Some compounds move rapidly up the paper, while others may scarcely move at all. The ratio of the distance a compound moves from the baseline to the distance of the solvent front from the baseline is defined as the retardation (or retention) factor R f . Different amino acids usually have different R f 's under suitable conditions. In the example on the right, the three sample compounds (1, 2 & 3) have respective R f values of 0.54, 0.36 & 0.78.	722	common-pile/libretexts_filtered	https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_III_(Morsch_et_al.)/26%3A_Amino_Acids_Peptides_and_Proteins/26.06%3A_Amino_Acid_Analysis_of_Peptides	libretexts	libretexts-0000.json.gz:13775	https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_III_(Morsch_et_al.)/26%3A_Amino_Acids_Peptides_and_Proteins/26.06%3A_Amino_Acid_Analysis_of_Peptides
Z5jTFoKsyTpHqLX5	34.1: Twelve-Tone Technique	34.1: Twelve-Tone Technique 34.1 Twelve-Tone Technique In a twelve-tone composition, every note can be accounted for as being a member of the original series or one of its permutations, providing unity to the piece as a whole. Additionally, a twelve-tone series is a repository of intervals and can be seen as an outgrowth of atonal music with its emphasis on interval over chord or scale. The basic premises of twelve-tone music are as follows: - All twelve notes of the chromatic scale must occur - No note can be repeated in the series until the other 11 notes of the chromatic scale have occurred (exceptions include direct repetition of a note, trills, and tremolos) - The series can be inverted, retrograded, and the inversion can be retrograded - The order of notes in a series remains fixed, without reordering. 34.1.1 Row Forms A twelve-tone series is also commonly called a twelve-tone “row,” and we will use the term “row” throughout this chapter. The four types of row forms used in twelve-tone technique are prime (P), retrograde (R), inversion (I), and retrograde inversion (RI). The prime is the original row. The retrograde is the prime form backward. The inversion is the original row with all intervals in the row inverted (going in the opposite direction of the original). Finally, the retrograde inversion is the inversion retrograded (and therefore might have more appropriately been labeled “inversion retrograded” since “retrograde inversion” sounds like it refers to the backward form inverted instead of the inverted form backward). 34.1.2 Transposition Numbers Each row form can be transposed to start on any note from the chromatic scale. We will use the same pitch integers as in set theory. For primes and inversions, we will use P and I accompanied by a pitch integer to specify the starting note. For example, P0 is a twelve-tone row starting on C (pitch integer 0), P3 is a twelve-tone row starting on E♭, and so forth. The same is the case for row forms like I2(starting on D), I5 (starting on F), on so forth. However, the retrograde (R) and retrograde inversion (RI) row forms use the pitch integer of the last note in the row to designate their transposition level. Therefore, R1 ends on C♯, and RI7 ends on G.	495	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Music/Music_Theory/Music_Theory_for_the_21st-Century_Classroom_(Hutchinson)/34%3A_Serialism/34.01%3A_Twelve-Tone_Technique	libretexts	libretexts-0000.json.gz:9725	https://human.libretexts.org/Bookshelves/Music/Music_Theory/Music_Theory_for_the_21st-Century_Classroom_(Hutchinson)/34%3A_Serialism/34.01%3A_Twelve-Tone_Technique
HWeMrlRhcuoqYQ0n	Catholic memoirs of Vermont and New Hampshire, with sketches of the lives of Rev. Wm. Henry Hoyt, and Fanny Allen. Also with accounts heretofore unpublished of the lives of Rev. Daniel Barber, Rev. Horace Barber, S. J., and Jerusha Barber, named in religion Sister Mary Augustin. Also with many of their letters.	When we first began to collect^onr Catholic memoirs of Burlington, we never dreamed that our compiTaHon would make a book of this size. We merely intended to increase devotion to St. Joseph by relating some of the favors obtained through his mediation, and also to correct some inaccurate statements which have been published, concerning Sister Fanny Allen, and the Barber family of Claremont, New Hampshire. We intended particularly to excite interest towards the new College of St. Joseph by drawing attention to the holy associations attached to the site which it occupies. We intended to say a few words about our dear Father Hoyt, who for many years lived in Burlington, and whose sacred dust lies now in the cemetery of Mount St. Joseph. But when we went to work we found so many interesting documents, heretofore unpublished, bearing upon our subject, that the work has obtained larger proportions than vre expected. We humbly, but firmly, hope that this work will be read extensively, because it is connected with the history of the Church, not only in Vermont and New Hampshire, but in all the States of New England, Canada, New York and many other places. We rejoice in the hope that the work will do much good, for it contains the lives of many heroic souls, whose examples Avill excite others to walk in their steps. Some of the letters which it contains will also be found most edifying to persons living in the world, or out of the world in religious communities. cese of Burlington, St. Joseph, the spouse of the Blessed Virgin, and foster-father of our Lord Jesus Christ, was born at Bethlehem, where pilgrims to the Holy Land are to this day shown the place once occupied by his dwelling. He was issued of the royal house of David, but had not inherited much of this w^orld's goods from his ancestors, and was obliged to earn his bread at the sweat of his brow, by working at his trade, which was that of a carpenter. Though unknown outside of Bethlehem, he enjoyed a distinction much more precious than the favor of men. He was, we may say it, without fear of exaggeration, more beloved of God, than any man then in existence. On the day that Mary and Joseph were united in holy marriage, I fancy that angels admired the blessedness of him who was to be the companion and protector of her who was the most exalted of all creatures, and destined to become the queen of men and of all heavenly spirits. What were the sentiments of those heavenly spirits towards Saii^t Joseph when they were sent to Bethlehem to adore the Saviour, Christ the Lord? For the infant God Vv'as found with Joseph and Mary in the stable, and the multitude of the heavenly host was commanded to sing : " Gloiy to God in the highest, and on earth peace to men of good will. " From the blessed moment of our Lord's nativity. Saint Joseph was under the special protection of angels who communicated to him the behests of heaven, concerning the holy family of which he was the head. Nothing can be more beautiful than the pictures of St. Joseph given us by Catholic artists. Each of those images convey to our souls sentiments of veneration, of love and confidence. Now we see him 6 CATHOLIC MEMOIRS. holding in his hand the white lily, a fit emblem of the purity of him who was the spouse of the most holy Virgin, and the witness of her virtues ; now we see him humbly standing before the manger, whilst the shepherds or the wise men adore the word incarnate and offer Hira their presents ; here we behold him carrying the Divine Infant in his arms or leading Ilim by the hand whilst journeying toward Kazareth. An interior view of the shop of St. Joseph represents him at work helped by the God-child, and finally vrhen the time of St. Joseph's demise has come, we see him assisted by Jesus and Mary in his agony. It thus happens that all the memoirs of St. Joseph are full of sweetness to well-instructed Christian. Fathers and mothers love to place their children under his protection. The laboring men who earn their bread at the sweat of their brows, consider him, as it were, one of their own ; one who feels for them and will protect them. They who are tried by poverty trust in the prayei s of Him who was the purveyor of the Holy Family, and the sick and the dying feel that the foster-father of Jesus and husband of Mary can not fail to obtain for themselves a happy death. There is another class of persons who love to implore the protection of St. Joseph. We refer here to missionary bishops and priests and to relis-ious communities, who devote themselves to the introduction and preaching of the Gospel in foreign countries. As the great St. Joseph was in the hands of God the instrument which He used to introduce the knowledge of Christ in the world, missionaries are convinced that by praying to St. Joseph their labors will be blessed and that many stray sheep will be brought back into the fold. DEVOTION TO ST. JOSEPH IX CANADA. There are in our days in all parts of the world a great number of religious communities of St. Joseph, of men and women, which have left their country and established themselves in distant lands for the purpose of preaching the Gospel of Christ amongst heretics and infidels. When Mr. de Champlain, the discoverer of our beautiful lake, way trying to found a Catholic colony in Quebec, at the beginning of the XVII. Century, he had to encounter very great dangers and dilficulties. Chief amongst those v^'ere the fear of the terrible Iroquois; the small number of the immigrants ; the ill disposition of the Huguenots who lived amongst them, and the want of help from the government of the mother country. Fortunately some of the settlers were fervent Catholics, and about the year 1624 they chose St. Joseph to be the patron and guardian of their country. This election was made by the people and the civil authorities ; it was approved by the clergy and confirmed by the Pope. The settlers of Quebec were Avont to celebrate the feast of St. Joseph with great solemnity ; and besides the solemn services in the church, they had on that day illuminations, processions and fire w^orks. St. Joseph rew^arded the piety of the good Catholics of Quebec, and a few years after their choice of him for their protector, he sent to their shores a remarkable Avoman, Mary of the Incarnation, who has been declared venerable by the church. Under the patronage, and as she herself believed under the inspiration and guidance of St. Joseph, she left her convent at Tours, in France, and founded in Canada a house of the Ursulines, for the education of the children and the conversion of the pagan Indians. To the labors of this saintly person and of her associates, Quebec owes to have preserved its faith, and to a great degree also to have been saved from many calamities. The blessings wdiich Mary of the Incarnation procured to Canada were partly communicated to us in the United States, as there are many of our Catholic ladies who were educated by them, and also because many houses of Ursulines have been founded from this first house of the order in Quebec. Devotion to St. Joseph continues to exist in the Ursuline convent of Mary of the Incarnation, and we here translate w^hat the annalist of their house wrote (1863) concerning the celebration of the 19th of March in their beloved convent. (She w^rote especially for the former pupils of the convent .) " Come back in spirit, dear reader, within the cloister on the 19th of March. To-day the church and the chapel have put on their choicest ornaments in honor of their holy patron. The greater part of the day is spent at the foot of the altars ; both the religious and their pupils strive to offer to St. Joseph the expression of their gratitude, of their love, of their confidence in his protection. Don't you think that his countenance to-day appears more radiant ? Methinks he loves to have such a load of requests to present to the Divine Infant whom he carries in his arms. " When this beautiful day approaches its decline, the religious family meets once. more to salute its glorious protector. First of all w^e visit the places which our patron guarded during the year. In place of the bonfires of old, the images and statues of St. Joseph have been decorated with lights and flowers. Here is St. Joseph of the treasury, guarding the treasury, keeping aw^ay robbers ; up the great stairs, leading to the granary, w^e have St. Joseph of the granary, w ho must provide his children with their daily bread ; in the kitchen we have St. Joseph at work, who, for two hundred years past, has blest the humble labours of God's servants. " We stop a little longer at the door of the Infirmary, and here our hymn to St. Joseph is one of our sweetest ones. St. Joseph watches vv'itli great attention at the door of this room ; he will welcome us here with a sweet smile, and promises to console us in sickness, to obtain for us a blessed death. "Let us go back to the holy place. How charming are the chants of which devotion and fervour constitute the chief harmony ! No doubt that angels carry them at once to St. Joseph, v>^ho is a patron and guide as they are." (Les Ursulines de Quebec, vol. 1, p. 308.) Concerning Montreal, the other more ancient and important point of Canada, it is remarkable that the founders of that colony, who were very devout Catholics, undertook its formation with a view to procure thereby the conversion of the Indians and to establish a community of Christians who, by their fervour, would emulate the heroic charity of the early Christians. For this purpose they planned the establishment of three religious congregations or communities, one of which, a community of priests, would employ itself in preaching the Gospel ; the other would devote itself to the education and instniction of the young, and the third to the service of the sick and the dying. In this manner, they justly thought, they would imitate the holy family of Nazareth. The priests, by their teachings and instructions, would continue on earth the work of Jesus Christ ; the teaching congregation would continue and show forth the virtues of Mary, virgin and mother ; and the third congregation, devoted to the care of the sick, would represent St. Joseph, the guide and protector of the poor family. I need not remark concerning Montreal, that the Sulpicians and the Sisters of the congregation were the two first communities which employed themselves in the care of souls and the instruction of the young. But the mission of St. Joseph on earth was there represented by the founding of the Hotel-Bleu, under the charge of the Sisters of St. Joseph . It was well for the young colony of Montreal that these devoted sisters were there in its infancy, when the colonists, so few in number, saw so many of their members v>'ounded or killed by the terrible Iroquois, As early as the year 1606 many of the soldiers who were stationed in the newly erected fort of St. Anne in Isle Lamot owed their escape from certain death to the care they received at the hands of these sisters, to whose hospital they were taken from their distant island. The Sisters of St. Joseph of the Hotel-Dieu are true to the spirit of their first mother, and in their immense and admirable new hospital at the foot of the mountain in Montreal, they nearly always have some patients of Vermont or other New England States. There many are cured, owing, perhaps, more to the pra3'ers and excellent musing of the sisters than to the skill of their admirable phj'sicians and surgeons. The Sisters of St. Joseph are a cloistered community. In their works of charity they are not encouraged b}^ the hope of being praised by men. The remembrance of St. Joseph ministering to the Son of God, the honor in the sight of God attached to this office, the hope of the greater reward promised to works of mercy, are the chief incentives to their life of devotion. As St. Joseph was the guide of Jesus Christ poor, Idnrj of the poor and founder of the evangelical p)oxerty , the Sisters of St. Joseph love to turn their eyes to him in the midst of their labors, and his pictures or statues are to be seen in all their departments or oratories. The picture of St. Joseph which we see more frequently in Montreal is the one v.diicli represents him journeying on foot with the Holy Virgin and the child Jesus. We presume that this representation is thus placed under the eyes of the Catholics of Canada, because from the beginning of its colonization the Catholic immigrants, as also the Indian converts, were frequently exhorted to w^alk in the footsteps of Jesus, Mary and Joseph. 8T. JOSEPH IN BURLINGTON. 11 Devotion to St. Joseph is a devotion of the Catholic church. No wonder, then, that some memorial of St. Joseph should have been placed in the Cathedral of Burlinf,^ton, the first Cathedral erected in New England. Was it not quite fitting that the chaste and holy Joseph should have a shrine near the altar of IVIary, immaculate in her conception?'^' In the old church of St. Mary, erected by the venerable Father Jeremiah O'Callnghan, in our city, there was also a statue of St. Joseph, which we still preserve, and before which many fervent praj'ers were poured forth to St. Joseph, before the erection of the Cathedral. It was out of gratitude for favors received by the Catholics of Burlington, that on the 19th of March, 1871, they unanimously elected him for the second patron of their parish, and after this event we had an additional motive to express to him our veneration and gratitude by erecting him a shrine in the new Cathedral of Burlington. His mother. Tv.'o angels hovering above the placid form of our Saint hold out a scroll with the words so appropriate to his position : " Blessed are they who die in the Lord, for their works follow them." In the trifoliated part of this window, suffering souls, from the midst of purging flames, offer fervent supplications to their Saviour. All this shows you that you are invited to come before this altar of St. Joseph to pray for a happy death for yourselves, and also to offer fervent prayers to God for the repose of the departed souls. If you noAV examine the altar itself, you will notice that the holy names, Jesus, Mary and Joseph are written in front of it in letters of gold, and that above the table of said altar there is a group of statues representing the holy family. This memorial of the Holy Family is fjuite appropriate in a church v.-here parents and children assemble to worship God and prepare their souls for eternity. God grant that children may imitate the meekness and obedience of Jesus Christ, that maidens and mothers may strive to imitate the purity, the devotion of Mary ; that the poor may learn to bear their trials as St. Joseph did, and to obtain a share in his devotion towards Jesus Christ, our Lord, his son by adoption. Fanxy Allen was the daiigliter of the famous General Ethan Allen whose remarkable monument stands conspicuous in the Green Mount Cemetery of Burlington, on the bank of the Winooski river, facing; the pretty village of that name. Ethan Allen, after the death of his first wife, had married at Westminster, Vermont, a widovr lady, Mistress Buchanan, on February 16th, 1784. Fanny was born on the 13th of November of the same year (from a note in Ethan Allen's handwriting, quoted by Z. Thompson. See Vermont Gazetteer, vol. 1, p. 570). Ethan Alien moved to Burlington in the spring of the year 1787, and settled on the farm known since as the Van Ness, and now as the Brooks farm. He died here in a fit of apoplexy on February 12th, 1789. It follows that Fanny Allen must have lived in Burlington two years, and was not five old years when she left it with her mother to return to Westminster, Vermont, after the death of her father. In October, 1793, her mother was married in Westminster to one Jabez Penniman, and she continued to live Vv'ith them in said town till her step-father, having been appointed collector of customs at Swanton (18C1), moved his family to this latter place, where they lived till 1809.* When his term of office was over, he bought the Penniman farm in Colchester, near the high bridge across the Winooski river. "Mr. Jabez Penniman was capable of appreciating the rich treasure committed to his care in the person of young Fanny Allen. Every advantage the country afforded was secured to develop and polish the gem of which he was inexpressibly fond and over which he watched with a solicitude as tender as her own father could have exercised." (Mrs. Julia Smalley in the Catholic World, vol. 16, p. 502.) From the pen of the same writer we have the following description of Miss Fanny Allen: " Fanny was the youngest daughter of General Ethan Allen, and inherited much of the energy and decision of his character, controlled by womanly gentleness. In person she was rather above than below medium height, and of uncommon beauty in form and feature. Her complexion was fair, her eyes dark blue, with a singular depth and calmness of expression, while the dignity and ease of her manners gave quiet evidence to the refinement and loveliness of her character. In the qualities which adorn the domestic and social circle, she was unsurpassed. (Vermont Gazetteer, vol. 1, p. 367.) FANNY ALLEN 13 Of the religious training and sentiments of Fanny Allen, the same contributor writes (in the Catholic World): "At that time the gay society in New England was tinctured with the species of infidelity introduced and fostered by the writings of Thomas Paine and his disciples, amongst whom Fanny's father had been conspicuous. Her stepfather, Doctor Penniraan, was not of that school, but he detested the cant and puritanism of the only religious people he had ever known, regarding them as pretensions, of which even those who adopted them, were often the unconscious dupes. He had never been drawn within reach of better influences. He conducted the education of his gifted daughter, therefore, with the most scrupulous care to avoid entirely all consideration of religion in any form. When her active and earnest mind would go beyond the veil he had so carefully drawn between its pursuits and the interests of eternity, and sent her to startle him with some questions touching those interests, which he could only answer by evasive ridicules, or an emphatic request that she would refrain from troubling her head about such matters, she would retire to ponder within herself, even while striving to obey her earthly father, the higher obligations imposed by one in heaven. Light and wisdom from above soon illuminated the soul that surrendered itself a willing victim before the altar of eternal truth. She was led by a divine hand through paths she knew not, to a temple of which she had scarcely heard, and whilst still living amongst those to v/hom the Catholic religion was entirely imknown, entered its portals to find herself, scarcely less to her own astonishment than to the amazement and horror of her devoted parents, a Catholic, as firmly established, and steadfastly resolved, as if she had been born and educated in the faith. " When Miss Allen had reached her 23d year, she asked and obtained the consent of her parents to go to Montreal in order to study French, but probably with a secret desire to obtain information concerning the doctrines and practices of the Cathohcs. " Before giving her their consent to go to Montreal, the parents of Fanny Allen required of her to receive the rite of baptism at the hands of a Protestant minister, and though strongly objecting to that desire she yielded to it in order to please her mother. The minister who performed the ceremony was the Rev. Daniel Barber of Claremont, Nev/ Hampshire, who was invited to the house. During the ceremony Fanny did naught but laugh, and the minister who perhaps knew nothing of her ' ' Here it was perceived that she was quite set in her own way of thinking. She would never accept a sentiment different from her own, except upon irrecusable evidence ; neither did she dissimulate her unbelief in matters of religion. On a certain day, one of the Sisters, by a sort of inspiration, asked Fanny Allen to take a vase of flowers which she gave her, and to carry it upon the altar upon which the Holy Sacrament was present, recommending her to adore our Lord Jesus Christ when she would enter the sanctuary. The young lady started smiling, fully intending not to comply with the request ; but as she opened the gate of the chancel she felt arrested by an invisible power, and quite unable to move a step. Three times did she endeavor to go up the sanctuary, and three times she failed in her attempt. Surprised and overcome she at last fell on her knees and in the sincerity of her soul adored Jesus Christ, of whose real presence in the Eucharist she then became fully convinced. Immediately after she withdrew to a remote part of the church where she shed abundance of tears and said to herself : 'After this miraculous occurrence, I must give myself up to my Saviour. ' She, however, did not at once inform her teachers of what had happened, but desired to be instructed, and made up her mind some time after, to go to confession. After she was sufficiently instructed, she made her solemn abjuration and was baptized by the parish priest of Montreal, Rev. L. Saulnier ; for the former baptism was invalid for want of consent on her part. After her baptism she received her first communion, and on this very occasion resolved to embrace the religious life. " (xVddiiion aux annalles hospitalieres Yille Marie), ' ' The circumstance of her conversion to the Catholic faith, at a time when very little was known of that religion in Vermont, was regarded as a remarkable one, and created excitement in her family, in general society where she was widely known, and peculiarily fitted to shine ; and indeed as far as the name of her distinguished father was known. This excitement of course was greatly increased, when her solemn determination to take the veil was disclosed. " (Vermont Gazetteer, Vol. 1, 567). Her parents immediately brought her back to their home in S wanton. In a beautiful description of a brilliant party which took place in Sheldon, Vermont, after the return of Fanny Allen from Montreal, after her conversion, we read the following passage concerning her character and her trials. (A Christmas Memory, Cathohc World, Vol. 16, p. 507). FAJSfJSrr ALLEN. 15 " The grief and indignation of licr parents knew no bounds. They looked upon it as a most disgraceful infatuation. Peremptorily imposing silence upon her in relation to the subject, they determined to suppress it, if possible, until every means had been used to divert her mind from the fatal delusion. All the vv'ilcs and artifices of the gayest and most fashionable circles in various American cities to which she was taken, were exhausted in vain to captivate her youthful fancy and deliver her soul from its mysterious thraldom. In vain the ardent addresses of devoted admirers, who were destined in the near future to be the brightest ornaments the bench and bar of their state could boast, were laid at her feet. In vain were all those worldy allurements, generally so irresistible to the young, spread before her. Her soul turned steadfastly away from each bewitching enticement, to solace itself with thoughts of the humble sanctuary in Montreal, where the weary bird had found a place in which she might build her nest, even within the tabernacle of thy house, O Lord of hosts ! "In the autumn preceding the Christmas festival of which I write, the ramblers had returned from their fruitless wanderings. Fanny's parents, discouraged and discomfited, resolved at this crisis to enlist the zeal of a few very intimate friends in their cause, by disclosing to them the great and unaccountable calamity which had befallen their child. "Among those v%^hom they earnestly entreated to aid them in their efforts to extricate her from the grasp of the great deceiver, was the lady with whom she was now passing the weeks of the early winter. A Connecticut Episcopalian of the High Church stamp, she occupied what they playfully called a ' half-way house,' at which they hoped she would be able to persuade Fanny to stop. She invited several gay ladies to meet and enliven Fanny's visit, but took the greatest pains to conceal from them the religious tendencies of her beautiful guest. She entered with great zeal upon every scheme for winter pastimes, in the hope of diverting the mind of her young friend from its absorbing theme. In their private conversations, she exhausted every argument to convince Fanny that the Episcopal church offered all the c'onsolations for which her soul was yearning. In vain, in vain ! She who had been called to drink from the fountain-head could not slake her thirst with draughts from scattered pools, which brought no refreshment to her fainting spirit. Tain also were the precautions used for concealment, fcjuspicions soon arose among her companions that there was something wrong with Fanny. A rosary had been partially revealed as she drew her handkerchief from her pocket. Worse still • a crucifix had been discovered under her pillow ! Here were proofs' of superstition indeed, of rank idolatry in unmistakable form, and no one knows to what unimaginable extent ! Tlicn it began to be whispered around the admiring and compaf sionate circle that she had not onlytaken the first step on the downward road, but was even now contemplating the still more fatal and final one of religious immolation ! It vvas their apprehension of this direful result which imparted a new and melancholy interest in their eyes to all her words and actions. Though she maintained a modest reserve upon the subjects dearest to her heart, they thought they could discover some mysterious connection with these in every expression she uttered. On several occasions, the most adventurous of her companions endeavored to penetrate the silence that sealed her lips in regard to her religious convictions, by direct questions, and, when these failed, by ridicule of such " absurd superstitions;" but to no purpose. Her nearest approach to any satisfactory remark was in reply to one of these questions : " It is impossible to convey any clear idea to your mind, in its present state, concerning these matters. Your opinions are founded upon prejudice, and your prejudices are the result of your entire ignorance in relation to them. If you really desire to be better informed, you need, first of all, to pray with humility for light and guidance, and then seek for knowledge. If you do this with sincerity you will surely be instructed, and ' know of the doctrine ;' but, if you refuse to take this first step, all the teaching in the world will be of no avail. ' They have Moses and ihe prophets ; let them hear them . If they believe not Moses and the prophets, neither would they believe though one should come to them from the dead.' " She rebuked ridicule with such calm dignity that it was soon abandoned, one of her assailants, a very lively young lady, remarking one day : " It is astonishing to see how terribly in earnest Fanny is ! She certainly believes in the Cathohc religion with all her heart, though how a person with her extensive information and splendid talents can receive such absurdities is a puzzle to common sense ! " But her severe trials were in her home. Her parents were unutterably grieved when she persisted in accepting the Catholic faith. This further determination to forsake those who had so fondly loved and tenderly cherished her, and who were to justly proud of the use she had made of the opportunities for improvement which their sohcitude had secured for her, was beyond human endurance. If she had been the victim of adversity or of disappointed hopes, there might have been seme excuse ; but that the idol of doting parents should abandon her elegant home to the desolation in which her departure would enshroud it, and turn from all the advantages that wealth, position and the homage of society could offer, dashing to the ground en tlic very tliicsliold of life the brilliant prcspeets which were opening before her, was worse than madncfs ! They ccraplaincd bitterly to her of her ingratitude and licaitlci^s diFiegnd cf Iheir feelings and wishes ; poured unmeasured and contemptuous reproaches upon her for stifling the modest wcmanly instincts cf her refined and delicate nature, to strike out boldly upon a new road hitherto untrodden by any wxman in New England. Kcmonstrances, pleading, reproaches and contempt were alike unavailing. LiEttnirg cnjy to the pcr.sua.sicns of that " invisible lover," whcsc voice had called her to relinqui.'rh the seductive charms which surrounded her worldly course, she turned away from them steadfastly, to follow Him and carry His cross up the steep and thorny paths of penance and self-abnegation, offering herself entirely to him on the Calvary made gloricus to her by His precious blood. Not immediately, however, like those whom He called of old, did she " leave the ship and her father to follow him."* Weary years of waiting and yearning, far frcm the 'tabernacle where her soul had chosen its home, did she accord in tender regard for the feelings of those, so truly and so deeply beloved, who could not give her up, and who had no clue by which to trace the course her spirit was taking, or power even to conjecture the motives that actuated her. When at length the time arrived to which they had consented to limit her stay with them, who shall describe the pangs that rent her heart in a parting so full of grief ; in severing those nearest and dearest ties, and in witnessing the anguish which overwhelmed those around whom her tenderest earthly affections were entwined ? no more than one, year. During the lenten season that intervened, she kept very strictly the laws of fast and abstinence, and in fact treated herself with so much severity that she actually injured her health, which w\ns naturally delicate. She declared to her parents that she must now embrace the rc- ligious life. Her mother, who was so fond of her, and had no desire but for her happiness, not only gave her consent, but went with her to Montreal. She had not yet determined to enter any one particular religious house, but had only resolved to consecrate her whole life to God in a religious community. With a view to make her selection, she visited the churches of Montreal, and amcngst the rest the Church of the Hotel-Dieu of St. Joseph. She hardly cast her eyes upon the painting of the holj^ family placed behind the great altar and beheld the face of St. Joseph, that she cried out and said to her mother : " That is himself. " She by these words reminded her mother of an event which had occurred when she was twelve years of age. As she vras walking along a river and locking out upon the water which was much agitated, she saw arising out of it an enormous beast of monstrous shape which was coming towards her. In her terror she thought she could not take her eyes from it, nor stir from where she was, when all at once she thought she saw near her a venerable, bald-headed man, Vv'rapped up in a brown cloak, and carrying a stick in his hand, who took hold of her arm, saying : ''Little girl, what do you do here ? make haste and run away. " At the sound of his voice she recovered her strength and made towards home in a hurry, turning about, however, to see the old man, but he had disappeared. When she reached home, her mother noticing her excited condition and the changed appearance of her features, understood that some extraordinary accident must have happened, and the child told her the best she could and the cause of her terror and the manner of her rescue by the old man. Mistress Penniman immediately sent a servant in search of this old man, desiring to thank him for saving her daughter ; but they could never find him or knov/ who he was. When Fanny Allen, in the Church of the Hotel-Dieu, recognized the features of the man v;ho saved her, in the portrait of St. Joseph over the altar, she was strengthened in the resolution to embrace the religious life, and bccam-C con\inccd that she miust become a Sister of ilic IIotcl-Dku of St. Joseph. It is unnecessary to knovr whether the event here related was a real apparition, or simply an impression produ';ed on her mind. Ee this as it will, she remained convinced that she vras indebted to this old man for the preservation of her life, and the remembrance of his features remained £0 present in her memory, that thirteen years after, she at once recognized the identity cf face and dress in the painting, and loudly expressed her surprise and astonishment. May we not say that this animal which v/as about to devour her, was a figure of the more terrible monster of Fanny Allen went at once to the Sister Superior, Mother de Celozon, begging to be received amongst her daughters. The Mother Superior, who knew very little about her, thought it well not to receive her in the house immediately ; she invited her to go back for some tim.e to the Boarding School of the Sisters of the Congregation, that she might acquire a more perfect knowledge of the French and be more thoroughly instructed in the faith. Fanny Allen followed this direction, — vrent back to the boarding school, remained there till the month of September Of that year, 1808, and was finally received as a novice at the HotelDieu on the 29th of the same month. The next spiing Mr. Pcnuimau and his wife came to Montreal to see her ; they visited the monastery in all its details, were surprised to see how happy, contented and perfectly united amongst themselves were the Sisters of this community. They had imagined that Catholic Convents w^ere no better than so many prisons, and they were so pleased with what they saw, that they continually spoke of the happiness of those Sisters, and congratulated the young novice on the choice of life she had made. She also felt so pleased to see her parents free from former prejudices against the religious life, that she seemed to grow more fervent in the service of God, and in the discharge of all the duties of her state. When the time of her profession had come (1810) many of her acquaintances of the United States came to v^itness this solemn action. They filled the whole chancel, and the church itself was ciuite full. All the Americans cculd not but wonder at seeing this young lady of Vermont shut herself up in a convent for the rest of her life. NoTF.s. 1. When Fanny Allen entered the Hotel-Dleu, that hospital and convent was situated across the street from the Sulpitian's house and the Church of Notre Dame A few years ago the former hospital was given up, and a new one built at the foot of the Mountain, which is remarkable by its immense size. 2. In almost every religious community there is a Sister, \\hose duty it is to keep a record of everything that happens in the community, and they are particularly careful to write down and preserve in their archives ever j thing cor necttd with the reception of novices and their profession or solemn consecration to God. 3. Vve have seen the picture of the Holy Family referred to above, where it was in the place where Fanny Allen saw it, and wo heard the historj^ of iliss Allen's conversion and subsequently embracing the religious life, just near the spot where the sight of the painting made such an impression on her. We have also conversed with some of the old Sisters, who knew Sister Allen, one of whom died lately (August, 1S84), at the Hotel-Ditu. The old oil painting of the Holy Fcmi'y has been taken to the new house near the Mountain ; but it is now so much defaced, that the Sisters keep it into their interior chapel. 4. Although Fanny Allen lived in the town of BurHngton (from 1787 to 1789) we think that the vision or apparition t;id not occur here but in Wcslmioieter, Yt., for» according to the annalist of the Hotel-Dieu, she was V2 years of age at the time of the WQurrence, and we see no reason to question the veracity of this historian, " Sister Allen, after her profession, realized by her zeal, regulniity and other religious virtues, all the hopes which the Sisters had formed of her after all the trials she had to go through before being admitted as a member." " During the few years that she spent in the convent she was nearly the whole time employed in teaching and comforting the sick who spoke the English language, and particularly the Americans. She cro"UTicd this glorious apostolate on her death bed, as appears from our annals. Her health was too delicate to permit her to undergo the fatigue attached to some offices, which, though much prized by men, are in reality nothing but a severe servitude. Sister Allen died at the ace of 35, after manv vears of sufferings and debilitv, and had lived only nine years as a professed sister. It may, therefore, h? rightly conjectured that when she appeared before her God, she had nothing to answer for others, but that she appeared before Him in glory, and replenished with joy on account of the many sinners she had brought back to the fold of the Divine Shepherd." (Letter of the sister in charge of the Hotel-Dieu, to L. deGoesbriand, 1885.) The following lines will show how decided was the character of the good sister : " Her step-father often spoke of the great trial her conversion and profession was to him and her mother, and that he steadfastlv refused to pavanvthino- luto the community on her account, intending to give what was due to her from her father's estate to. her brother, until he found it would make no difference in her decision, as she cheerfully but respectfully declared to him that she would servo the convent in the kitchen and household work in lieu of the fees just as willingly as in the nursing department." (Mrs. Julia Smalley to L. deGoesbriand, May 21st, 1S85.) Sister Allen lived happy far away from friends and country, realizing in her person the promise of Him who said : " Amen, I say to you. there is no man that hath left house, or parents, or brethren, or VN-ife, or children, for the kingdom of God's sake, who shall not receive much more in this present time and in the v,-orld to come, life everlasting." (Luc xvni : 29, 80.) Her Sheldon friend (1) visited her repeatedly, and was amazed to find her radiant with a joy which her countenance had never before revealed, happy in the peaceful home that offered only poverty and an unceasing round of labors in the service of the sick and sufferinir, with ' I think it was during the third winter after Fanny Allen entered the convent that my mother's (I) interview, to which you refer, took place. My aunt, Mrs. Pierce, my mother's sister, lived in 3Iontreal, and upon her occasional visits to her sister, she always called, as she had promised, to see Fanny. "Upon this occasion there was, as usual, another sister in the room, and my mother asked Sister Fanny, in a low" voice, if she might be permitted a few words with her alone, upon wdiich she spoke in French to the other sister, who left the room at once. My mother then came very near Fanny, and taking both her hands in her own, said very solemnly : ' I have so longed, my dear Fanny, to ask you a question which you may not, perhaps, be at liberty to answer under your present obligations, but I have felt so anxious that I could not sleep nights for thinking of you ; and I know you will, on that account, excuse me if I seem impertinent. I have feared, beyond expression, your making the direful discovery that you had committed a fatal and irretrievable mistake, and were consequently suffering sorely in an enforced silence. You have now been here long enough to know" the w^orst, and I beg that, if you may not tell me in tcords, you will, at least, give me some token by wdiich I may know" if my fears are well founded.' " Fanny, surprised and puzzled at first by my mother's mysterious manner, no sooner comprehended the drift of her question and anxiety that she gave w-ay to such a peal of laughter as was perfect music to my mother's ears, and sufficiently answered the cpestion without words. As soon as she could speak from laughing, she exclaimed : 'And you, too, my dear friend, of whom I have hoped better things, are still enthralled under the superstitious bondage of poor, benighted Protestantism in regard to the conditions of the conventual life ! ' "My mother assured her that her mind w"as entirely relieved, and she could now think of her, as contented and happy in the choice she had made, with perfect satisfaction. When about to leave Fanny said to her : "Now to convince you that I am not imprisoned within these walls, as you suppose, I will take a little walk with you outside of our enclosure. " So throwing a hooded mantle over her head and shoulders, they passed out into the street. The weather was intensely cold, the sidewalk very icy, Fanny, accustomed to walk only upon tloors, found it extremely difficult to keep from slipping, and my mother, " Multitudes of New England people visiting ^lontreal Hocked to the Convent, begging to sec the lovely young Nun of the Hotel-Dieu, who was the first daughter New England had given to the sacred enclosure and whom they claimed as belonging especially to them through her connection with their favorite revolutionary hero." So continual were these interruptions, that she was driven at length to obtain the permission of the Mother Superior absolutely to decline appearing in answer to such calls, except when they were made by friends of former days, for whom she still preserved and cherished the liveliest affection. " (Catholic AVorld). " On the eleventh year after taking the religious habit. Sister Allen was seized with some affection of the lungs, and the disease having become alarming, she asked of the Mother Superior to be attended by an American physician of her acquaintance who resided in Montreal. The request was granted. The doctor, who was a Protestant, did all in his power to restore her to health, but in vain. Providence permitted that he was present when she died. When he saw all the Sisters bathed in tears, praying on bended knees, when he heard the priest recite the prayers for the departing soul, he was much impressed ; himself fell on his knees, remaining motionless in the most respecf ul attitude. The Sister Superior having requested him to say if Sister Allen had expired, he raise d his eyes to heaven and said : ' Yes, she has expired. ' The priest, Reverend Father Hubert, then recited the prayer, 'Come to her assistance all ye Saints of God.' The doctor again knelt down to the end, seeming to be much affected with a sight which was so new to him. lie published in the papers a relation of the death of Sister Allen.* He added that he would never more in this world see the Sisters of the Hotel-Dieu of St. Joseph, but hoped to be reunited to them in Heaven. He left Montreal without informing any one of his project. The Sisters of Hotel Dieu, although they inquired much about him, have never been able to learn whither he went, and conjectured that he had gone to Europe intending to join the Church and enter some religious community. " (Annals of the Hotel Dieu). "la Mr. J. H. Derwin's lleminucences of Montreal, he mentions that on December 10th, 1819, he heard that a Sister called Sister Allen, had died at the Hotel-Dieu on St. Paul Street, and that she was a dauirhter of the famous Ethan Allen. He immediately hurried to the * DwoUinff ui.on the consolations which tlie Catholic Church affords to the faitliful children at th(ir l)n.•!sa^■e from time to etornitv, eighteen months after he sold his riropcrly. and wrote to the Sister iMiiierior of the Hotel-Dieu stating that he would never forget the pi'^ht he had wiinessed at the death of Sister Allen. He added that he . . etc., etc. Sisters prayinii^ for the repose of her soul. He wondered to himself how Ethan Allen's daughter ever became a Nun, and strange she chose for hei* peaceful home, the very city where her father met his wTjrst The remains of Sister Allen together with those of all the Nuns buried in the former Convent on St. Paul Street have been removed to a vault in the basement of the new Convent near the Mountain. The names of all those interred there have been preserved, but there is nothing to show the particular spot occupied b}' those of Sister Allen. The humble Sisters in their Convents strive both in life and in death to practice the precept of the great Apostle St. Paul, ' to mind the things that are above, not the things that are on earth. ' Whilst yet living they are dead and their life is hidden with Christ in God, but when Christ shall appear, which is their life, there shall they also appear with Him in glory. (Colos. iii. 2 et sccq). "Is this a dream, the page of a romance ? Is it only history ? the history of a past forever ended ? No ; once more it is what we behold, and what happens amongst us everyday. Who, then, is this invisible lover, dead upon a cross, eighteen hundred years ago, who thus attracts to Him youth, beauty and love ? who appears to them clothed with a glory and a charm which they cannot withstand, who seizes on the living flesh of our flesh and drains the purest blood ofour blood ? Is it a man ? No ; it is God. There lies the secret ; there the key of this sublime and sad myster}'. God alone could win such victories and deserve such sacrifices. Jesus, whose God-head is among us daily insulted or denied, proves it dail3^ by those miracles of self-denial, and self devotion which are called vocations. Young and innocent hearts give themselves to Him, to reward Him for the gift He has given us of Himself, and this sacrifice by which we are crucified is but the answer of human love to the love of that God who was crucified for us. " (Montalembert), PREFACE TO THE BIOGRAPHY OF REY. DANIEL BARBER. The name of Rev. Daniel has often been mentioned in connection ^yith that of his son, Virgil Barber, S. J., and of his grand son, Samuel Barber, also a priest of the Jesuit order. Heretofore very little has been known about the venerable Daniel Barber. It has been our good fortune to find two pamphlets, now extremely rare, both written by our Patriarch. The first of those pamphlets was printed at Washington in 1821. its title being Catholic Worships and Pieti/ Explained, and Recommended in Sundry Letters to a Very Near Friend and Others, he having gone South to Maryland from Claremont to obtain more instructions about the Catholic Church. About the year 1822, when his son Virgil, being now^ a priest, was sent to Claremont, Daniel Barber came back thither, then returned to the South after the death of his wife and the removal of his son Virgil to the State of Maine as missionary to the Indians. Ilis second pamphlet. History of My Oicn Times, was printed also at Washington (1827) ; and in consulting these two books together, we have the history of Rev. Daniel Barber, and also some remarkable letters and addresses of his. In the book of memoranda of Right Rev. B. Fenvick, Bishop of Boston, we found a few passages which also throw more light upon the life of Rev. Daniel Barber. It is now seen that our work is a mere compilation, but we sincerely hope that it will prove to be one most interesting. God grant that it may procure the glory of God and sanctification of men ' " The writer of this small compendium was born in the town of Simsbury, Connecticut, on the second day of October, 1756, the year after the great earthquake, which shook all New England." (History of My Own Times, p. 3.) ' 'My father, whose name was Daniel, was a man who in those days had a greater taste for reading than his neighbors in general. Though he possessed no means of information respecting the Catholic religion, yet I often heard him say of Henry the Eighth and his reformation, that it was all a horse jockeying scheme. In the latter part of his life he withdrew from the Congregational order and joined Sergeant Deicey's meeting, for which he was made to feel the severity of the law in Connecticut * (p. 6). My father and mother, while both of the standing order, could never agree as to points of their faith. In their conversations on this subject both had recourse to the Bible as the main or ultimate judge between them. Each by habit had become well skilled in managing their own side of the question. Each had always at command a multitude of Scripture passages, which, to use a military phrase, they exchanged shot for shot. They both believed that the Bible contaiccd infallible truth, but in what particular text or passage it was to be found they never could agree (Ibidem.) My father, by means of the American revolution and the depreciation of paper money, lost nearl}^ all his property. Jle died on the 17th day of April, 1779, aged 46 years." Speaking of his earl}^ recollections, our Rev. Daniel Barber says : "I well remember my mother's habit of signing each loaf of bread with the sign of the cross before it was put into the oven for baking, and the same was the practice of many others. My mother could give no other reason for this, than because the same was done by her mother, and although tliis sign had its proper meaning, as well as its original, of both she was ignorant, and although the sign had lost its meaning, still the habit of using it had become so confirmed as seemingly to claim its right b}' possession. This fact of itself makes it clear to me that my ancestors on my mother's side were at some former remote period members of the Catholic faith. At her death she left nine s:urviviDg children, viz. : six sons and three daughters.! Daniel, at the age of sixty-two years, at the expense of all icorldly expectations became a Catholic. The youngest sister, Nabby, who married Mr. Koah Tyler, with her husband and seven children, became converts to the Catholic faith. All her daughters, four in number, are at Emraetsburgh (1827), where they have taken the vows and put on the habit of the sisters and profess to enjoy much happiness in their letirement from the world." (P. 13 and 14.) Our writer served two short terms during the war of the Revolution. About the year 1787 Mr. Daniel Barber moved to Vermont, with his wife, Chloe Case, daughter of Judge Owen, of Simsbury, Connecticut, his three sons and one daughter. " The youngest, a son, died at the age of three years, five months and eight days. His mortal part we committed to its kindred dust in the burying ground in the village of Manchester, Vermont." (History of My Own Times.) motives of his conversion. ' Since many persons have signified wishes to be informed of the way and means, or more properly, the motives and reasons for my changes in religion. I thought it might be acceptable, at least to some, to give here a distinct narrative : '• Having been born and educated a Congregational Dissenter, of the strict Puritanic order, which was at that time the prevailing religion in Connecticut, my native State, I continued in that faith and worship till I was about twenty-seven years of age. The first occurrence which gave me occasion to examine the grounds of authority in the Priesthood, was a challenge given by D. P., an Episcopalian, alleging that my minister (for at that lime I was a Congregationalist) was destitute of that true sacerdotal authority, without which no man could be a minister of Jesus Christ. As I had been taught, so I believed that one and another, both learned and unlearned, as the case might happen, were directly and spiritually called to the work, and that call REV. DANIEL BARBER. 27 Was of itself a kind of investiture of the sacerdotal character and office ; and that the mere form or ceremony of laying on of hands, as among Dissenters, was a sort of token of acknowledging such and such a one to be what the ordaineis were ; that is, ministers. D. P., my neighbor, put into my hands a small volume, containing the most conclusive reasoning in support of the Apostolic order, and the succession of the real Priesthood. By reading v»'hich I was soon confounded for want of reason and authority for the support of my fanciful scheme of ministerial power given immediately, and invisibly to one and another. However, having been so long wedded to this belief, I did not feel in the least disposed to give up the point. And in order to furnish myself with proper weapons to repel the attack, I soon carried the said book to my minister, with a request that he would read it, and then give me such arguments as the nature of the case required. After keeping it a while, he told me that I had better take it again, saying, " there had already been enough said and written on that subject ;" and signitied his unwillingness to have anything to do with it. Sorelv vexed and disappointed as I was at the bare apprehension of a failure in a cause so interesting to my feelings, and so certain and clear as to its substance, I applied to another minister of the same class, and made my complaint concerning the neglect of the former. There I received an answer well calculated to liU up the full measure of my done the best thing he could ; for, (continued he) had he undertaken to interfere with those arguments, he would very soon have brought an old house about his ears. " I began now to reflect whether true military characters engnged for their king and country would so tamely suffer their commissions to be trifled with. While those things were in my mind, there happened to be a military day for parading and exercising the militia, and many people collected together. When I came among them, I found this same D. P. in the midst of a crowd of people, who were attentive to his reasoning down the foundation of Congregational ordination and defending the doctrine of Apostolic succession. The champion of the dissenting party, with whom he was engaged, seemed to me very apparently to sink under the weight of the argument, as I perceived by his going to call one of the ministers, who was not far distant, to assist him. This minister, however, as it was then understood, refused, or was too prudent to enter the list in the presence of so many people. The event was, my neighbor P. put his antagonist to silence. In consequence of this dispute, more or less immediately declared for the Episcopal Church, one of whom I became acquainted with. The most I remember now of the argument on the part of the Dissenter, was, that the Church of England could not be possessed of any true ecclesiastical authorit3% owing to the corrupt state of the Church of Rome at the time of the separation. By this time, it may be rcasonabl}' concluded, I must feel compelled to quit a society, whose ecclesiastical authority or Priesthood was of such a nature as I could not defend, nor find any willing to do it for me. Yet, to part, to make a final separation from that, and embrace a different one, was a thing to which I could not at once bring my mind fully to yield. To effect this, caused a year's reflection. I was breaking off from a friendly connection with such as were my nearest relations and best friends. To separate from them and form a religious connection with strangers, was such a trial as excited and awakened many tender feelings, which 1 have not forgotten to this day. At length I became resolute, and bid a formal adieu to one kind of religion and joined myself to another. But how little did I then think that those very arguments which had brought me to the Church of England, when pursued up to their full extent, could not fail to convince me that by joining the Church of England I had gone not more than half way towards the proper place of safety. In becoming an Episcopalian, I will remember one popular difficulty I had to encounter. It was a religion which, from its very first introduction into New England, had ever felt the heavy hand of its enemies. To be a churchman there was at least a sort of disfranchisement in the public esteem. Church-man and heretic was formerly supposed to signify nearly the same thing, and it was not uncommon, when a Dissenter joined himself to that church, to ask " What develish trick has he done? " To give some idea of the spirit of the times, since ray remembrance, one anecdote will suffice. A Church of England minister died in Connecticut, whose name was Muirson. Afterwards died one of hi5 communicants, whose name was Isaac Knell. I mention these things with no other view than to convince people of the necessity of that candor which leads to an examination of principles, instead of taking it for granted that whatever is reported is true. The tree which is the most beaten often is found to yield the best fruit. priest by Bishop Provost in the church at Schenectady, State of New York. I continued for nearly thirty j'cars clear of the least doubt or suspicion concerning the correctness and validity of our ordinations. But at a certain time, and while on a journey, a Catliolic author was put into my hands, and as chance would seem to have it, the first page I opened called my attention to a subject which seemed to bear a near relation to the challenge given me so long before by my friend D. P., and reminded me of the common saying : " Bad news is apt to be true." The passage I mention contain some reflections on the consecration of Arch bishop Parker. It is set forth that after the Queen had in vain applied to several Catholic bishops to consecrate Parker, she, by virtue of her own authority, empowered a certain character, namely, Barlow, witli certain others, to perform the consecration. An order made afterwards by the Queen was as follows: "Supplying, nevertheless, by our supreme royoX authority, from our mere motion and certain knowledge, if any thing, either among those things that were done by 3'ou according to our aforesaid mandate, or in you, or in any one of you, your condition, state, or power, be, or shall be wanting, of the foresaid things, to be done, which, by the statutes of this kingdom, or b}^ the ecclesiastical laws are required, or are necessary, the state of the times and the necessity of affairs demanding it." Unfortunate as it may seem for the Church of England, whose ecclesiastical authority depends wholly on the validit}^ of Parker's consecration, it could never be made to appear that Barlow" himself was ever consecrated by anybody. The truth is, according to the histor}^ of those times, and even ths first bishops of the reformation themselves have left on record, no authority excepting what flowed from the Crown was considered of much importance in the church. Fretted and perplexed at finding this unlucky passage in the 'Catholic author ; and still entertaining hopes that some more skilled in church history, who might put my appreljensions asleep again, I soon wrote to a very learned clergyman, but received no answer. I have since concluded that he possessed an equal share of wisdom and prudence with the CoDgregationalist ministers before mentioned. About this time I called on a Catholic priest, for the first time, for I had never seen one before. I asked him many questions relative to his religion, and the many reports I had heard concerning the faith and worship of that Church. lie treated me v.'ith much kindness and respect. On entering his church for the first time, which was the first I had seen ; observing others bless themselves with the sign of the cross ; and reflecting that, as Episcopalians, we claimed ourselves to be a real branch of the Catholic Church, I also did not hesitate to make use of the same token pf faith. A stranger observing me, made some reflections. I answered him that I belonged to the old Church, the Church of England. lie said the Church of England was not a very old Church. 1 confess this seemed something like another challenge. I carefully avoided any further altercation, for fear the ground on which I stood might prove hollow. But to return. The priest answered all my questions in a very pleasant and sensible manner, and I began to th uk whether he might not suppose me much more ignorant than I had before thought myself to be. To disclose our ignorance voluntarily is often attended with equal mortification as the showing our sinful leprosy to a Priest. The latter we show onl}' with a view that we may receive a cure, the former is too often deeply rooted by habit to be eradicated. The priest, on my taking leave, lent me several books explanatory of the Catholic religion. In these my familj soon found their accounts, as well as some others. The first thing which struck my mind forcibly, was, the Apostolic injunction, respecting anointing the sick \\ith oil ; and I began to ask my brother ministers why that practice was omitted? If it was needful in primitive times, why not so still V One of them, a very learned, sensible man, supposed that the oil, used in anointing the sick by Priests in those days, was such as had been consecrated for anointing kings and prophets ; that so much as was left, was afterwards appliei for the use and benefit of the sick and dying. I observed, that if I understood him, the oil he referred to was strictly forbidden to be used in any such case, and was to be a curse to any man on whose flesh it might come. He seemed to ponder but said no more I once, and again, proposed the same question, to a more dignified character. His reply was : "It is true that it was a practice in the days of miracles. " Whether just such answer had any meaning I could not tell. I began now to think that some others might possibly appear before the priest I visited to not much better advantage than myself. I well know, that of late, some have sought a subterfuge under Courayer, a desperate Roman Catholic priest. Honest minds, however, will defer any conclusion from his reasonings, until they shall have examined these writers on the other side of the question, viz : D. Gervaise, Hardwin Le Quien, etc., not forgetting that although Courayer labors to establish the consecration of Parker, he seems not to hesitate in saying that the Church of England, by her separation, has cut herself off from the communion of the true church, and seems to advise that she again return to her mother. His conclusion on the subject very clearly leaves it at least no better than he found it. llorce, against Bonner, the Catholic Bishop of London, for refusing to take the oath of the Queen's supremacy. At the commencement of the trial, Bonner entered a plea, as a bar to the prosecution, stating that Home the prosecutor was no Bishop. The court agreed that the fact, whether he was a Bishop or not, should be determined by a jury of the country. What was the issue ? Why rather than that a jury of twelve honest men should determine the question, the cause wa.s taken from court without a trial, and carried up to Parliament ; there it was suiTercd to sleep the sleep of death. And Bishop Bonner was sulTered to rest quietly without any further trouble. Although the Queen was far from entertaining a favorable opinion of Bishop Bonner, yet it would seem that her principal judges possessed some share of the prudence I mentioned of the ministers, f jr, no doubt, had they declared Home to be a true Bishop, there might have been some danger of bringing an old house about their ears ; since, at that period, none could well be in douljt what was the fact, nor of the reason w^hy the Queen first applied to the Catholic Bishop to perform Parker's consecration." In 1807 Rev. Daniel Barber had baptized Fanny, daughter of Ethan Allen, as we have seen in the biography of that remarkable convert It has been repeatedly stated that he was also present at her I rofession at the Hotel-Dieu, that he visited her, that he w^as much impressed with her heroic determination, so that his conversion to tlie Catholic faith was due in great measure to her influence. His visit to Bishop de Chevcrus must have taken place about the year 1813. He again relates as follows about that visit to the Bishop: "He treated me with great candor. I had never seen a priest before. He gave me an understanding of the principal things which made the separation between us and the Catholic church. He also furnished me with several books to carry home. These proved quite a treat in my family. They, by reading, soon appeared well convinced of the truths they contained, and wished to see a priest, but the nearest was a hundred miles distant. These few books scattered fast amongst m}^ Protestant neighbours, and those more particularly who had a taste for inquiry. In lime some of the heads of the parish began to make complaint that those books I had lent among my parishioners were calculated to do much harm. I said, how can they do harm? Are we not a branch of the same church? If not, what is our foundation and on wJnit do we stand? Arguments are of little use to minds sealed against inquirj-. One of my Protestant brethren on the like occasion used an argument which I have thought the most conclusive the case would admit of, he saying: " We are Protestants and you can't help it." After considerable conversation, I agreed to gather iny books and make them secure. I put them under lock and key. But I soon found that, by the help of some of my children, they again found their wa}', more privately, abroad." "About this same period, my youngest son (Virgil), then a Protestant parson in Fairfield, State of New York (near Utica), with his wife paid me a visit. While the}^ were at my house, 1 took an opportunity now and then to read to them out of those books." During this visit the Reverend Daniel Barber, feeling an interest for the soul of his son, Rev. Virgil B., whose mind was open to conviction, came upon him on a certain occasion whilst at his toilet (shaving), and read to him a telling argument found in Milner's End of Controverxy (Father Fitton). "But the name Catholic sounded as harsh to them as it had done to old Mr. L. Sometimes I could prevail on them to listen to an argument or an explanation of some particular point of doctrine. Hearing me read, they would sometimes i'Q\)\y, saying, that is good reasoning. When they were about to leave us, they requested the loan of one of the books. Glad, indeed, was I of the opportunity of granting such a request. They took the book with them and departed. But how little did I think that before I should see them again, himself and family would become converts and his wife a nun! " " 1 saw neither of them again till my son returned from Rome in 1818. He then came to Claremont, in company with the Reverend Dr. French (or FFrench, a Dominican father, an English convert, living in New York). This was the first priest that ever came to my house. He arrived on Saturday evening. On Sunday morning he said Mass in my house. I attended, and afterwards went and performed tlie usual services in my own Church. I would have asked him to preach in the Church, but for fear it might give offense to some. In the evening, however, Dr. FFrench preached in my hou.se to a respectable number. He staid through the week, and the next Sunday said Mass and preached both parts of the day, at what is now called the new brick church. In the course of this short period he had seven converts, amongst whom were my wife and daughter, my sister, Mrs. Tyler and her eldest daughter. Rosette Tyler. to give quite as much alarm as the Catholic books had done. My wife, who was one the first in making an open profession of the Catholic faith, was a woman who possessed a strength of mind and resolution which qualified her for so important an investigation, and by which she set at naught, the fear of man and the voice of the multitude. She improved tlie first opportunity of separating herself, and embracing the standard of the cross, from which she never separated till death. She departed this life on the eighth day of February, 1825, in the 79th year of her age. Her last words, and while making the sign of the cross, were, "In the name of the P'atber and of the Son and of the Holy Ghost. Amen. " She was the first who lie buried in the Catholic grave yard near the St. Mary's church in Claremont. May she rest in peace. Amen. " PARISH. " On the 15th of November (if I am right) A. D. 1818, having taken a regular dismission from my parish, I took my final leave, publicly by an address from the pulpit, it being Sunda}^ and we parted, generally speaking, as friends, and in the spirit of peace and harmony, in which w^e had so many years lived and walked, w^ept and rejoiced together. It was at least on my part, a trial in which I felt, and could not but feel, the finer and most tender emotions, and to which the falling tear bore full testimony. And indeed what less could be expected, while bidding adieu to a people whose best tokens of kindness and respect, had for the space of twenty-four years afforded me so much comfort and consolation ? The bare reflection must ever endear them to my remembrance. ]\Iy friends and brethren, how natural is the reflection that all temporal things are mutable and transient, and the most pleasing friendships and connections in life are of but short duration, and there are particular times and seasons when the heart feels most sensibly the disappointments of all its hopes and wishes. When we meet to bid adieu to the friends we loved and whose families we admired, and whose faces we shall see no more, then^ if ever, is the time when the plaintive voice, and the bursting tear, speak the language of the heart, and express the genuine and tender feelings of the soul. On so interesting an occasion, my mind naturally looks backward to scenes that are past and gone, wishing to take one more glimpse of those pleasing and happy days, in which we have walked together in love and friendship, as fellow-travellers, whose mutual care and interest it was to shun fatal disasters, and if possible never to fall out by the way. My mind looks back again to melancholy scenes through which we have passed along; those days of calamity and distress, when like friends we have mourned together, wept together, and sympathized together; how often have we comforted one another and shed the tear of condolence, when the hand of God touched you; when the desire of your eyes has been taken away, or your friend and acquaintance shrouded in darkness; who was ever afHicted and I did not weep? Who was sorrowful, and I was not sorrowful? And I weep still with them that weep, and would, if possible, wipe away the tears from every son and daughter of affliction. We look back once more upon the past; there your hospitable and friendly mansions arise full in my view; those social and calm retreats, those scenes of contemplation and sympathizing friendship, these I must bid adieu; here I must take up my cross where none can carry it for me. Let me bear it, then, with faith and patience, and strive to imitate Him who was made perfect through sufferings. How important, then, must it be to me, to be fully satisfied that in all my public and private admonitions and administrations I have endeavored to lead you into all truth profitable to salvation. As my stewardship is now ended, whatever remains to be done must be the work of some other hands. Remember there is a time approaching when we must receive as we have done; and when it will be inciuired of me what has become of the sheep I left with you in the wilderness. Did you carefully instruct them? Did you guide them by your counsel? Did you lead them to pastures of life and health everlasting? If I can answer yea. Lord, to the best of my abilities and allotments, happy will it be for me; acd happy will it be for you, if through faith and patience your names shall be enrolled in the Lamb's Book of Life. Nearly twenty-four years, and the best of my days have been spent in the service of the Church to which you belong, and from which I now retire to the humble walks of private life and to the still and silent shades of peace and poverty. that tremendous hour, which will put a period to all my works. And when I shall slumber in the tomb and be forever gone, let my remembrance have a claim to that mantle of charity so needful to cover the faults and failings, for which I have nothing to plead but the weakness and imperfections of human nature. " From Manchester wc removed to Claremont, where I w^as settled as minister of the Protestant (Episcopal) Church, with the provision of a comfortable support. In this Church I continued for the space of twenty-four years, in perfect friendship and harmony. I know w^ell it is treading on dangerous grounds, wiien in such an age as this, I shall declare it as my firm belief that the only means by which I was first led to inquire for the truth, was none other but the spirit of God. Truth in religion was ever my aim and delight, but the best means w^as not within my reach, or the compass of my knowledge, unless I had found it in the Church of England. The real difference between that and the Catholic Church I did not understand. Wishing for information on that subject, led me to introduce myself to the Rev. Dr. Cheverus, then a priest in Boston. " Daniel Barber was the first member of his family to enquire into the merits of the Catholic religion, but his dear son Virgil, and his son's wife and children, his own wife and some other relatives in Vermont were admitted in the church before him . He had friends in Washington and Maryland, and after taking his dismission from his congregation of Episcopalians in Claremont, he started south, desirous to obtain further instructions about the doctrines and rules of the church before making his profession of faith in it. It may be surmised that a desire to live near his son Virgil, and to enjoy the privileges of the church in a Catholic country, helped him to determine to leave Claremont for a time. During his absence from New Hampshire he was received into the Catholic Church. In 1822, Virgil Barber, after making his religious profession, was ordained priest by Bishop Cheverus and by him sent to Claremont as a mii^sionary priest, with the consent of his superior. His A^enerablc father resolved now to return to Claremont and about that time he wrote the foUowins: letters to his former friends in Kew Hampshire : INTRODUCTION. It is a natural principle in all men to be disposed to religion, and in case they fail in that which is true, they will be disposed to embrace that which is false. Among those who claim the right of choosing for themselves that faith which their fancy or judgment may approve of, there will always be many who are very liable to change, especially among such as have recourse to the holy scriptures as the onlj' rule of their choice ; and although such changes are frequent, and generally proceed from apparently pious motives, is it not natural for us to inquire in particular cases what those motives were? Such inquiries arc Whenever I shall return again to you, my former brethren, it is quite probable that many among such as I have baptized, and admin, istcrcd to in other holy things ; as also those with whom I have wept and rejoiced, will feel, at least, seme curiosity to inquire amf)ng other things, why I have made a change in my religion ? And particularly why I have become a Catholic ? So natural is it to ask, when we see a man with a cross upon his shoulders, wdiy does he carry it ? Anticipating such inquiries, my answer shall be according to that simplicity and affection in which I ever taught and instructed you in former times, wdien it was the wish of my heart to lead you in the ways of piety to a spiritual composure of mind and to that truth of the soul wdiich is everlasting. In this way I endeavored to lead you according to the measure of my knowledge and skill. Honest minds may think differently, yet truth and error can never be the same ; and whether our faith be right or wrong depends not at all on the opinion we may form, or the good liking we may have for it. The sun does not cease to shine because the blind man does not see it ; nor is the providence of God checked because a sceptic may please to deny it. That religion, whose design is the happiness of man, is from heaven. Its faith, its doctrines, must, therefore, be holy and divine. It must then be perfect, and unchangeable as He who once gave the law amidst the thunders and lightning of Mount Sinai. What it was, the same it is, and ever will be ; not like man, liable to change and decay, but stamped with the hand of its divine author, it alone will stand amidst the desolation of empires and the wreck of worlds. You again ask me why I am Catholic ? I answer for the same reasons which make me a Christian ; for, in former times, Catholic and Christian meant the same thing. " My name is Christian, says an ancient Father, and Catholic is my sur-name ; " or, I will answer in the words of a celebrated author, M. De la Harpe, " I am a Catholic because I have examined ; do you the same, and you will be one too." To this question I will answer as briefly as possible ; but before I do this, I beseech you, my brethren, to listen to me with candour and patience. Divest yourselves of all bitterness and prejudice. Endeavor to eradicate any unfavorable impression which a preconceived opinion may have made upon you, and bring to this subject a heart that pants after the truth, and a mind wdiich will embrace it, whenever, through the ministry of an angel or a man, it shall be made manifest to you. Without such disposition, controversy may but arouse your passions, or gratify an idle curiosity ; while on the other hand, with that happy temper of mind, which they must beget, becomes the vehicle of instruction, and the means of obtaining eternal life. Truth, my friends, may contradict our former or present opinions, and thwart and perplex our favorite ones ; nay, it may even compel us to take up a cross on that ver}' spot where hope had promised us a crown. But if, nevertheless, it be but barely possible that without the knowledge of the true faith, and the practice of the things it commends, we may be lost, then, is it not wise to pause while we are standing here upon the brink of eternity, and ask ourselves the question, " Is it not at least, possible that Jesus Christ has established but one Church ? " And is it not at least equally possible, that salvation cannot be obtained out of it ? Now, like jur}Tnen at court, you sit down to hear and judge a case, and a cause, too, Avhicli, in its nature and consequences, is the most important that can be conceived. For it is the cause of God among men. It is a cause in which you yourself are a party, and as such the decision you shall make will produce the most happy or the most dreadful consequences in eternit3^ And as the question before you is one in which you have an everlasting concern, God demands of you a righteous judgment ; and since He demands it, he will give you the grace to render it. As the discoveries which I have made in my researches are, that Protestant writers have persuaded us to believe that their religion is more ancient than the Catholic, and, indeed, that the Protestant was the first, or original Christian church, these likewise state that there have been two important changes in religion since the days of the apostles ; that is, the first from Protestantism to Popery ; the second from Popery to Protestantism. Thus at one time these were the means whereby men might be saved, and at another they had entirely disappeared from off the face of the earth. Now on these two changes rests the whole ground and support of the Protestant cause — that is, if it can be made to appear beyond a reasonable doubt that the church made and constituted by Jesus Christ and his apostles was Protestant, in that case the Protestant stands on safe ground as to his religion, while the Catholic ought to fear and tremble. But if, on the other hand, it can be demonstrated that the Catholic and not the Protestant was the original faith ; in that case the Protestant is not safe, but has every reason to be alarmed at his situation. That the Catholic religion was original as to its present form, and so did not proceed from Protestantism, is a position proved and supported by the following reasons : and this by reason of some doctrines in the Catholic church, %Yhich, in case they were not taught by Christ and his apostles, could never have been introduced but with the greatest diniculty imaginable. Some of these difficulties I will mention. It is a principle among Protestants as with Catholics that Jesus Christ has alone the power of instituting sacraments because he alone can appoint proper instruments of conveying grace to our souls. Now, if Protestantism which allows of but two sacraments, was the religion taught by the Apostles, and the established religion, I ask any man, to judge by what means five new sacraments, never heard of in the time of the Apostles, could afterwards have been imposed upon the church, and rendered articles of faith, without the greatest difficulty, without clamor, noise, and the most stubborn opposition ? The thing is almost incredible. At Vvdiat period soever we may suppose the supposed alteration, would not every good Protestant Bishop immediately have stepped forward, and placing himself in the gap, have cried out against such an innovation, and such monstrous impiety ? What ! the revolutions in states and empires ; the changes in government ; the improvements in arts and sciences shall be recorded, and handed down to us on the historic page, and those of religion, the most grand and important of subjects, shall not be noticed ! Is such a thing reasonable ? Is it credible ? No ; in such a revolution ; in such a change, the dreadful consequence of universal idolatry, would not each Protestant have taken up his pen, and alleged that Jesus Christ had established only two Sacraments, that the Apostles had never established but two ; that the precise number, two, had been handed down to them by the immediate successors of the Apostles ; and that therefore, no human authority could add another, without impiety and sacrilege ? It is impossible but they would have stigmatized the first authors and abettors, and have soon cut them off from the communion of their church. The least to be supposed is, that the bishops and pastors, then living and acting, and being of the same religion with the Protestants of the present age, would have exerted all their power and authority in a matter so important, unless we suppose them to have been all asleep, and lulled into a state of entire indifference. In pursuing my inquiry on the ground that the Protestant was the original Christian Church, I found out my subject embarrassed and hedged about by many other, not less powerful difficulties ; one of which is, how that original Protestant Church which claims herself to be the elder sister of the Catholic, ever came to introduce the worship of the mass, for, here we are to consider them as taking everything relative to their faith and worship directly either from the Apostles themselves or those who did receive from them. Strange, that when the Apostles liad taught them to offer simple bread and wine, merely as a memorial of the sufferings of Jesus Christ, and that instead of this, they should, in after time, so change the order, as to make it an offering of the real body and blood of Jesus Christ, and a living sacrifice to be daily offered for the benefit of the faithful, whether living or dead. Now, as all Protestants do deny, that in former times, and while the Catholic Church was not yet in existence, the mass was a doctrine ever taught by an Apostle ; the only conjecture must be that it was an invention of some one or more individuals among them at first, and from whom it spread itself far and wide, and at length became everywhere universal. But to suppose all this would seem to exceed the utmost stretch of an imagination, sporting in realms of possibility. What has been done may be done again, unless it be miraculous. And will the same means produce the same effect ? Will any means whatever produce the effect, so as to produce in all Protestants a confidence in, as well as a love for, the Mass ? Does the present hatred which prevails everywhere among that class of Christians towards the Mass, look anything like an argument in favor of the supposition that it was at first introduced and became the general belief of Protestantism, and that too, without any noise or opposition ; that like a secret charm it pervaded whole kingdoms and empires, and so still and silent in its introduction and progress, that not one historian ever attempted to mark the period of time when, or the place where, it first made its appearance ; and yet, that all this did so happen, I must believe ; or else I must not believe that the Protestant religion is more ancient than the Catholic. My examination next brought to my view auricular confession ; this was an Apostolic doctrine, or it was not. If the former, the dispute is ended — the obligation is imperative, and the Protestant claim of being the first Christian church, since they deny it, falls of itself to the ground. But supposing it not to be of divine origin, but a scheme of human invention, here I am to encounter several potent difficulties : For, as it is not merely a point of speculation, but a practical and very humiliating duty, and indeed so crossing to a man's fallen nature, and the pride of the human heart, that no man would ever have submitted unless he was first convinced that he could not be saved without it, the difficulty of introducing such a practice, considering it only as a human invention, is not lessened but increased, by the consideration that no dignity in the civil or ecclesiastical departments could have power to exonerate a member of the church from the obligation to confess. All Bishops, Kings, Princes, even Emperors and Popes, have their equal share in this burden, with the meanest slave ; these must fall down at the feet of their confessors, while they discover their most secret sins, submitting themselves to his censure, and to perform the penance ^vllich he may hiy upon them. Now, to say that this practice was not taught by the Apostles, but that it was afterwards continued, made up, and introduced by the cunning craftiness of some, without any rational motive to be accounted for, yet became a universal practice ; in such case, the cpiestion is naturally asked, v/hich of the tvro is most surprising, the extravagance of those who first invented this yoke of bondage to be laid on themselves and others, or those who quietly submitted to it ? For that this burden was universally submitted to is an unquestionable matter of fact. And that it would have been so submitted to without opposition, without noise and notice, cannot with good reason be believed. Hence, then, I inferred, that the Protestant was not that primitive church which Jesus Christ established ; and if it was not, then my inquiries were next directed to the important question, whether the church called the Roman Catholic Church was, or was not, that identical church, the divine Saviour of mankind had founded ; and on which, by promising to be with, till the end of time, he had conferred the glorious prerogative of infallibility. My inquiries led me to that conviction, and the reasons which wrought this conviction, 3-0U will find in the folloT\ing letters, which were written to a beloved friend. [The substance of the following letters to a particular friend were not written with any other design than to correct and soften those hard and bitter feelings entertained against the Catholic religion and worship, merely from a prejudice produced by misinformation, and the want of correct knowledge ; they are now offered to the public, together with some ethers written with a i)rincipal view of inculcating sentiments of piety and the love and fear of God]. My Dear Friend : It is now some years since I have had the pleasure of seeing you or any of your family, though in the mean time I have been sorry to hear of many things spoken by you concerning myself and others of the family in consequence of our professing the Catholic faith and worship. You cannot but know, such hard and unkind treatment, and for no other cause, cannot but hurt and wound those feelings of tenderness and affection which connected us from our birth, which "grew vrith our growth and strengthened v>ith our strength." In the choice of religion vv'c all have an equal freedom ; but to make a right choice, truth alone must guide us, and v,dierever that leads we must follow. Nothing could have tempted me to change my religion but a full conviction of the danger and risk I must otherwise run of losing my future life, and that world to come in which dwells righteousness. As these, and these oi\\j, were the motives of my change, I should have hoped and expected that one so near and dear by nature w^ould have considered me but as a reasonable man inquiring after important truth ; for important it must be to any one born an alien from the household of faith, as myself w^as, to be led back with an inclination to be instructed in a religion which I must consider as the only one in -which we can have any sure confidence. My friend, can this be a crime ? Is it a crime for any one to look well to the care of his soul, even at the loss of all his worldly honors and possessions, and his best friends on earth ? In case ycu have hitherto made no choice in religion, or have taken to yourself one which cannot bear full proof of its Divine Original, my prayer is, that you may reconsider the subject, and by your own earnest prayers seek unto God to give you the knowledge of the truth. A mistake in such a choice may prove destructive to that lasting happiness w^e w^ould earnestly wish for. As a friend, let me entreat you to lay aside every thing but good sense and candor in your perusal of these letters ; and as I have written nothing but simple truth, let it have its due weight on your mind. So far as your mind at present may indulge any false or erroneous opinions, it is clearly my duty to endeavor, as far as I am capable, to correct them. Amidst the confusion of the w^orld, I know of but one means of safety, and that is to be attentive to the command of Jesus Christ — hear the Church and obey the Church. He did not say Churches, for there was but one ; that one He promised should continue to the end of the world— that He w^ould be with it, and that the Holy Ghost should lead it into all truth. No other religion has ever had the like promise. Can we then be perfectly safe in following any other ? You cannot say so; for then His promise to that church w^ould have been of no importance. From the manner in which I have treated the subject, you must be convinced that the Catholic is that original religion to which the promises Avere made. If so, what then can we look for or expect from any other? In one the promise is sure and divine, and is ample security to our souls in well doing. In the other, w^ho can show one promise given it by a power divine ? Let me, if possible, persuade you by that soul of yours which is the gift of God, and which will endure forever, that you lend a favorable ear to what now most intimately concerns your eternal welfare. Death, my friend, may be near ; at no time is it far from us ; for wiiat is the longest life on earth. We are no more secure of heaven because we see multitudes like ourselves pursuing principally the objects of the world. Tell me, Avliere are those who take delight in imitating the lives of the blessed Saints and Martyrs ? These were always at their post. The world never hindered them from their prayers, their confessions, and the sacrament. By their fervency and devotions they obtained a foretaste of that happiness which shall be revealed, and for which they suffered and endured all manner of hardships, cruelties, and even death, courageously, by the flames or the sword of the persecutor. If heaven cost them so dear, why are we to expect it will be afforded us so cheap, and on terms so easy and accommodating ? The v,'orId which now promises so many lengthening years of happiness will soon slide from beneath our feet, leaving us pale and lifeless to mingle with common dust. What can avail us in that dreadful day, the day of judgment, unless we have been diligent in seeking after truth with our wdiole heart, and with a full determination to conform our lives to its doctrines and precepts ? My friend, how shall I persuade you to turn your heart and affections to that church whose banner is a cross, and whose reward is a kingdom ? Shall I persuade you by the joys of angels, the prayers of saints, the blood of martyrs, and the tears of holy virgins, who have wept and bled, and died for the catholic faith ? Think what happiness they now^ enjoy, who, while on earth, took so much delight in worshiping around the altar and the tabernacle wiiere is the true manna, that real and spiritual body and blood, that life-giving food to the faithful, that clean sacrifice daily offered both for the living and the dead ? You will ask, perhaps, wiiether miracles are performed in these latter days ? Let me beg the question and ask why not ? Can you show me a text in the New Testament which says there shall be no more miracles ; or tells us which was the last ? Do not all candid historians agree that the great St. Augustin wrought many miracles in England about the year 700 ? And if credit is due to candid and impartial testimony, we can have no reason to doubt their having been wrought thro' the mighty power of God, even in our ow^n time. But as such a belief is no article of Catholic faith, I will leave it for the present, and turn to another subject, and indeed one w^hicli my present feelings naturally suggest. The enemies of Jesus met Simon and compelled him to bear the cross. How often do clouds and storms arise in a quarter where we expected a clear sky, and perpetual sunshine ? How often are we left and forsaken bj'' those whose hearts we never suspected, and whose friendship we fondly believed would never fail. But when some of us could no longer hold good faith with the reformation, and for the sake of a good conscience turned aside to worship at the altar of incense and a pure offering— Malachi 1 : i i — we are left and forsaken by those we had long loved and admired ; our dearest friends and nearest relations, even some of our own mother's children, with whom we enjoj'cd long and pleasant days of social friendship and delight, and with whom we felt nothing more sensibly than the kindest affections warm from the heart and sweetened on the tongue. Can it be possible that these, and such as these, should ever combine, like men in battle array, to wound and injure, by sharp words and unfeeling reproaches, and for no other cause but for having embraced the catholic faith ? From sources like these the heart feels, and ever must feel, the wound it receives. It faints under the weight of such a cross, and turns aside for relief. Fain would it seek some lonely vale ; some silent shade, some retired wait ; some place to weep ; to pray ; to meditate, to examine and learn from the lives of Saints and pilgrims, what were their trials and mortifications on earth. Was the path they trod rough and thorny ? And is it the only one which leads to happier mansions ? These in their life-time worshipped at the same altar, and have transmitted down to us the same faith which proved sufficient for them, and is the only one we can safely confide in. Still we go on heavy and sorrowful ; our former friends have forsaken us, or stand afar off. O Jesus ! God of Christians, is not this one of the nails of Thy cross ? Painful and afilictive as it is, what is it in comparison with thy sufferings for me ? Yet it causes me to weep sore and complain, saying, when will the time come, and I be clean escaped from these low elements, this perplexing region of sin and strife, where man is often the enemy of his fellow man : enemies to the love of Jesus Christ, to the one faith, and to that one religion which alone can secure to us a blessed and happy life to come ? But, you may ask, why make choice of the Catholic religion, as you very well know it is a religion in most places contemned and abhorred ? ]My friend, does the world generally hate that which is evil, or that which is good ? Did it love Jesus Christ and His Apostles, and those holy martyrs who suffered death for the faith ? A religion, the world hates, may be the only one which heaven approves. But we will pursue the subject. In addition, then, to the reasons already urged for my embracing the Catholic faith, it is the first and most ancient religion. It is the only one sanctioned by Jesus Christ, its divine founder, and the only one, too, to which He has promised the Holy Ghost, and a permanent continuance to the end of the world. All other religions are destitute of a divine original, and being mere human inventions, can depend only on the fidelity of their authors. Divine faith, which alone can save the soul, must be sought for where the spirit of Christ is ; and that spirit is, as it ever was, with the Church. For the truth of this turn to all the saints whom God has blessed for the holiness and sanctity of Not one of all these, but was of the Catholic faith. In this church is to be found full and ample provision and knowledge so needful for the restoration of the sinner to the mercy and favor of his God. To this end he is taught humilily, contrition for his sins, confession, penance, and absolution ; which absolution is promised in his favor by that same authority— :\[at. 28—" Whose sins ye remit they are remitted unto them." Will you ask, can man forgive sins ? He can, when Jesus Christ has given him authority to do so. And such authority has never yet been wanting in that church to which He gave the Holy Ghost. And that church was then, and is noic, the Catholic. It is difficult, in most cases impossible, to arrive at the knowledge of truth, unless we divest ourselves of prejudices. You have heard much of the Catholic Church ; and of that much but very little indeed to induce you to admire and esteem it. But, after all, is it not still possible that this is the only church which our Divine Saviour has established ; and that in this only is to be found that true faith, without which we cannot please God ? Suppose this to be but barely possible ; and then have I not a right to admonish you that to find the truth, we must not only seek it, but seek it without passion or prejudice ? It will be quite natural for you to reflect, that my advantages in inquiring after truth have been somewhat superior to yours, and that the result of my inquiries has been by no means terminated in a plan reconcilable to worldly wisdom, or connected with prospects of ease and temporal felicity. What is earth compared with heaven, or a short life of worldly poverty and contempt when put in competition with the joys of eternity, and the life which is to come ? Our souls, made after the image of God, and redeemed by His blood, are too precious to be lost through negligence, or a heedlessness in searching for the true and only path trodden by the saints and martyrs of all ages. If they were not Catholic, tell me what were they ? In their right hand they held a crucifix, the token of their faith. They attended the daily sacrifice of the altar ; they fell on their knees at the feet of God's minister, to confess their crimes,— they passed their time in prayer and good works —they invoked the angels and saints to assist them by their prayers and intercessions. Surely they must have been Catholics. Of this you cannot but be convinced, by reading what they have left upon record for our instruction. And just as sure as we can be, of any tmth in the Bible, so sure we are that the Catholic is the only true religion of Jesus Christ— that is the first, the original which Jesus Christ authorized and established, that in it man might reap the fruits of the Redeemer's blood. What a misfortune it is to us,' my friend, that we were born and educated aliens to that household, or family, that mystical body for which Jesus Christ shed his most precious blood ; that church to the safe-keeping of which He gave the faith, the doctrines, the priesthood, and every means of salvation, as the holy spirit also to be with it, and in it, to guide it unto all truth in believing, that our faith might stand in the power of God, and not in human wisdom, and to which was also given an authority to remit the sins of the meek and humble penitent. Mat. 28. The promise of Jesus Christ secures the continuance of this church to the end of the world. It has already continued more than eighteen hundred years ; and though frequently assailed by the hands of violence, and the storms of persecution, it stands secure on the rock en which it was founded ; and against it " the gates of hell shall not prevail." The trials and persecutions it has endured have served to confirm, and not to shake, its foundation. My good friend, I wish I could lay before you the lives of her saints, and the sufferings of her martyrs. If your heart were not made of adamant it would bleed and soften, and be disposed to weep at the bare recital of the cruelty and barbarity of tyrants on the one hand, while on the other, so much faith, so much piety and patience, even unto death. St. Stephen has afforded us the first example ; and after him, thousands have been called on in like manner and resisted unto blood. Had the same persons been united, and the same exertions employed against any other order of men, but the Catholics, it must certainly have destroyed them, or worn them out. Do I here relate to you strange things, or things of which you have never heard ? Then do apply to some neighbor who may be acquainted with church history, and he will inform you of the sufferings of the Catholic church by means of those dreadful persecutions which Pagan Rome inflicted on her. Thus read, inquire, examine, and pray Almighty God to give you a right understanding, that " the truth may make you free," My friend, once more adieu. !>• B, It is probable that you, lilvc many others, entertain a high opinion of Martin Lutlier, and his reformation. For, you suppose the Catholic church had been corrupted in her faith and worship. Such a supposition is, however, false and groundless, and unless you can tell me what these corruptions were, at w^hat time, and by v.hom they were first introduced, you can gain no credit with reasonable men, w^hose faith in Christ's promises is firm and steadfast. "I will send you the Holy Ghost and he shall abide with you forever." " I am with you always even unto the end of the w^orld." As to her faith, doctrines, and worship, the Catholic church was then just what it is now, and just what it was in the early ages of Christianity. The reformation was right at the beginning, or it was not. If right then, it is not so now ; for the first reformers of the English Church held strictly to the doctrine of transubstantiation, and burnt to death such as denied it.* If the reformation was a Godly work, why did it produce such a flood of wickedness as caused a general complaint in all countries where it spread ? Why did those reforming Bishops in England clamor so loudly of the sins of the times, w^hich they charged altogether to the effects of the reformation ? Of these I could give many quotations from Protestant authors. But leaving these for the present, I will only notice some effects in one single point of view, and that is the endless divisions it has produced in the religious and ecclesiastical state of society. For a full proof of which, look on our own country, into our neighborhood, into our family. How rent and torn asunder, by dividing into sects and parties, even to the destruction of that love, peace and harmony, those dear delights and sweetners of all our toils and all our cares. When Martin Luther stood, as he says, a long time alone, in the work of reformation, let me ask who, or where at that time was the true church of Jesus Christ ? Was Luther then, singly and alone, the Holy Catholic Church, or was there more upon earth ? And if none then, there is none now, nor ever can be, unless Jesus Christ comes again to make and establish one. A man may make his own church, but net the church of Jesus Christ, any more than he can make a world. In short, my friend, the reformation was in all respects calculated to produce on society the same effects as are naturally produced in a family where all the children are left without pious example or instruction, to choose for themselves what course they will pursue, or w^hether they will most approve of ways and means tending to virtue or vice, You contend for christian liberty. But unless you understand the full measure of it, you may intrench upon licentiousness, or fall into "damnable heresies." There is a line beyond which you tread at your peril, it is holy ground. This line separates between duty and foil}' — between faith and presumption — between the prerogatives of Jesus Christ and those duties He demands of us. And where do you find that he ever gave a man authority to make a new religion, or new model an old one, given by him to His Apostles for the salvation of men's souls to the end of the world ? Reflect seriously one moment. Ask the people of the old world if they could save themselves out of the Ark God had provided. They will tell you that their own devices were but folly : the hills, the mountains, the trees, in which they placed their confidence, could afford them no succour in the dreadful day. Ask Jesus Christ the way to salvation. He says, hear the Church. As the old Bible did not coincide with those new doctrines, the reformers, to make it as far as possible yield to their wishes, disfranchised and condemned 142 Chapters. And not only so, but they gave many remaining texts a different language from what they had ever spoken before. They made Job's wife say to Job, "curse God and die," instead of "bless God and die," as in the old Bible. My dear friend, do j^ou not believe that faith is necessary to salvation ? I am sure that you will answer that it is. The next question is, what is that faith we arc bound to believe in ? Here the only rational answer to be given is, that at least it is the very faith which Jesus Christ revealed in the Holy Scriptures, and which He commanded His holy Apostles to preach and us to believe ? Now what is that faith revealed in the Scriptures ? Is it whatever you may please to believe ? If so, it is likewise whatever your neighbor may please to believe. For you have no more right to believe what you please than he has. Thus, if you have a right to believe the doctrine of the Holy Trinity, because it appears clear to you in the Scriptures, has he not an equal right to disbelieve this mystery, if he cannot find it there ? Do you not sec that in this way there will be just as many faiths in the world as there are men of different opinions. If among all these there be but one faith in the world which can be true, then all others are false ; and can a false faith lead men towards heaven ? As to the only certain means of finding the true faith, let me draw your mind by comparison. Look at what happens often in temporal affairs. A father dies and leaves a will : the children all good, kind, and affectionate, loving each other, meet together : they open the will and read it : they begin to think differently as to the meaning of soihe things contained in it : they talk the matter over again, and again, but 60 far from agreeing, they but differ the more. Ko^v, how shall they be reconciled ? By telling them to look at the will again ? But the more they read it, and the more they ponder on it, the more the difference becomes magnified. What course is left for them ? Why, fortunately the wisdom of man has provided a remedy, by erecting a tribunal to examine and interpret testaments and wills according to law. To this tribunal the contending parties apply ; it hears all their reasons, it pauses, it deliberates, and finally decides upon the matters in dispute, by declaring the meaning of the will of the deceased in all its parts ; and the disputes are at once ended. And let me ask what are the Scriptures but the last ^ill and testament of Jesus Christ ? And seeing as we do by the diversity of creeds, that the meaning of them is not alike plain to the understanding of every man, does it not appear reasonable to you, that there should be a tribunal to declare what they mean ? As for instance, whether infants ought to receive baptism— whether Jesus Christ is Gcd, or a mere creature of time, as many pretend— whether it be the meaning of Scripture that at the day of judgment the good and the wicked shall both fare alike, as som.e preachers contend ? Isow these and each of these, are questions of much importance, and for the want of a living judge, and a competent tribunal to determine them, as is done in matters of a temporal concern, too many pious, well-meaning people are confounded, divided, and rent asunder ; become aliens to each others faith, by which the tender heart of charity is wounded. Each plainly sees his neighbor's error, and as carefully avoids it for the sake of his own. Thus every man judging for himself proves to be a fruitful source from v/hich new articles of faith are produced, and schism upon schism is multiplied ; while ignorance and error seal thousands for destruction. The least reflection convinces us, that, in civil society, there must be laws, and also judges to understand and interpret those laws. A thousand law books, without judges legally authorized, would give but little or no security to men's temporal interests, especially if every man, woman and child, was to be his own judge. We will suppose that all the books written on law and jurisprudence be committed to the hands of the people ; at the same time, all legal judges, and every court of justice, to be annhiliated ; and upon the same principle, that every man being competent to judge for himself in spiritual things by having in his hands the books of God, and the laws of Jesus Christ, so every man, by having in his hands the books which contain the rules of law and equity, and which are much easier to be understood, as being the mere productions of human wisdom and skill,~suppose every man assumes to himself the office of a judge, in all matters in which he feels himself or his temporal interest concerned. In such case, what would be the consequence ? AVhy, civil society would be at an end. Eyeiy man's hand would be against every man. The world vrould be filled with violence, rapine and murder, and from which none could be secure but by burying themselves in lonely deserts, and by seeking a retreat from their fellow -men in mountains and forests. Kow, if human society cannot suT)sist without laws, and judges to interpret thorn, how shall we find the true faith, and the will of the blessed Jesus, concerning those particulars I have mentioned ; that is, Christian Sabbath, infant baptism, whether Jesus Christ is God, and whether all men, whether good or bad, are to fare alike after death ? I ask how can we all come to a certain understanding of the truth in these cases, unless there be some authority empowered hj Jesus Christ to declare the meaning of what He has left on record for the use and benefit of his church and cf all who wish to be his people ? In all matters of disputes, doubt, and uncertainty, relating to cur faith and practice, Avhere shall we go for a perfect understanding ? Don't talk to me about searching the Scriptures. Our forefathers did it, and they left the Church of England and became the followers of Robert Brown, a reformer in the daj's of Queen Elizabeth Our parents did it, and each changed his religion, but each embraced separate ones. Brother C. did it, and became confident that the Standing Ordci* is a religion quite as old as the Apostles. Uncle J., by the Bible, was convinced that the Standing Order was not quite so old, and turned to be a follower, as he said, of John the Baptist. An old lady in New Hampshire, (I was told,) searched the Bible until she vras persuaded that only herself and two more were to be saved. A man with whom we are both acquainted, Mr. R. M , did the same, until he found himself alone in a religion partly Jewish and partly Christian. You have as to his religion, stands yet quite alone. He is a serious well-meaning man, and wished for a reformation in religion, and undertook himself to lead the way, and be the first in the good cause. Like Martin Luther, he stood alone. But certainly a much better man. For while Martin, by reading the Bible, found a comfortable latitude for breaking his most solemn religious vows, and giving a loose rein to the passions and appetite of nature, M n, by reading the same Bible, corrected them in a great measure, by following an ab^^lemious manner of living, denying himself whclly of seme kinds of meat, according to the law given to the Jews. He also became convinced of the necessity cf long and very Now let me ask seriously wliy M n alone had rot as good authority to begin a new order in religion as any of the reformers, especially since he took, as he thought, everything he adopted out of some part of the Bible ? I say, why had he not as competent authority as Martin Luther, Henry VIII, John Calvin, or Robert Brown ? No one can deny that all these pretended to find their different religious in the Bible. And as many more may be found in it by such as are wise enough to know that Jesus Christ did not mean it, when He said, "This is my body, this is my blood." Cannot the Quaker show better grounds for denying water baptism, as he called the Baptist for denyina- infant baptism, the Seventh Day Baptists for keeping Saturday ; or even the Unitarian for his denying the divinity of our Blessed Saviour, than you can do for your denial of the real body and blood in the Holy Sacrament ? Adieu, once more. D. B. Your plaintive letter of November came duly to hand ; by it I am notified that the husband, the father and the friend, has taken his last and final leave. Deep and sorrowful is the reflection to those who knew him, but especially to those of his family. Under this severe visitation, methinks I hear your sighs, and witness your tears. One crying in all the likeness of woe, my husband is dead ! the long and delightful partner of my joys and my sorrows, has fallen at my side ; I am as one left solitary ; and even in the midst of my comforters I seek to weep alone. At the right hand methiuks I see the children, the sons and daughters of my friend leaning one upon another, all bathed in tears ; and while taking one more view of the pale and ghastly remains, seem to say one to another, " Oh ! that dear fond father, who has comforted us all our life long, who caused our mornings to pass agreeably away, and delightfully our evenings, is no more ! That empty seat, and the station he so often filled in our little family circle serves only to imprint on our memories his familiar and endearing conversation ; those lessons of wisdom and worth, mixed with cheerfulness of mind and a sweet disposition. Pale death has scaled those lips, and imposed on that tongue a long and everlasting silence. " Yes, my friend, how often have you listened with delight to his paternal precepts, and the endearing lessons of his love and affection. And when those delightful and improving hours were ended, and you retired to your chambers, what happiness, what pleasure, what gratitude did you not feel ; and with what tender affectionate sensibility of soul, say one to another, how happy the children of such a father ! You have closed his eyes, and deposited his mortal part in the tomb, till the joyful day of resurrection, Ccn.fort one another, in faith, in love, and in good v/orks. And when you look down on his grave, recount his virtues and imitate his worth. In the meantime, please to accept the falling tear of your friend ; and one whose gratitude of his favors, whom you mourn and whose feelings are too deeply impressed ever to forget the worth of him, whom I shall sec no more. D. B. St. Inigoes, December, 1819. jSTote. — Here I would wish to notice, that our people of New Eng land have generally very mistaken ideas concerning the condition and treatment of slaves. It is true, I can speak from personal knowledge only in respect to St. Mary's County, Md., where I have spent nearly twelve months. Here the blacks are generally treated more like children than slaves. I have indeed been surprised to see much kindness and tenderness manifested to the young slaves, by masters and mistresses. The blacks appear to take quite as much comfort and satisfaction in life as their owners ; and I am persuaded, had they the offer of freedom, that a very large proportion of those slaves would not accept the offer. In truth, I have found but one instance where the black people were hardly treated. D. B. Very lately I have received through the channel of a newspaper, information of the death of your daughter Mary. This unexpected and melancholy news naturally awaken the pathetic and tender feelings of a friend, and more especially of one who, in former times, had the pleasure of being not only an associate, but at times an inmate of your family. How natural in reading the sorrowful tale, to look back in reflection, and call to mind the times which are passed, and those agreeable happy days of friendship now gone forever, and like all those fleeting scenes connected with human life, no more to return. Nothing continues long with us the same. We look back but a short dis- tance, and arc astonished at the changing scene ; and in the very midst of our reflection we are surprised at beholding those innocent circles of purest friendship and sincerest affection, broken in upon by the untimely fall of one. A deep and pensive gloom gathers on every countenance, while the social joys of the little friendly community are suddenly turned to SDbs of grief, or broken-hearted sorrow, especially when called to close the eyes, or to view for the last time, the pale earthly remains of one so lately the flower and pride of the little band. Alas ! my friends, what earthly delights and filial joys are covered in the deep recesses of the grave ! That fading flower, that child of joy, the once flattering hopes of her parents, and the fairest expectation of her friends, is gone ; she has retired behind the scene, and sleeps to wake no more. How freely could I weep over that little mound, that heap of dust, that mouldering clay. Ah ! Mary, what wert thou once ! and now what is all that remains of thee ? Let us pray for the faithful departed : "Grant them eternal rest, 0 Lord! let perpetual light shine upcn them ; and may they rest in peace. Amen." To pray for the dead in Christ, was a universal practice, till Martin Luther, that unfortunate Roman Catholic Priest who first laid the foundation from which have been raised up all those divisions and desseutions in faith and ail ecclesiastical matters. Praying for the dead is a practice indeed older than Christianity itself. Mace. 12, 43. Hence every pious Catholic concludes his night prayers with " God the father bless us ; Jesus Christ defend and keep us ; the virtue of the Holy Ghost enlighten and sanctify us this night, and forever ; and may the souls of the faithful departed through the mercy of God rest in peace. Amen. " My friends, whatever maybe your own private opinion on this subject, convinced as I am, that this practice was never omitted by the faithful, and the first fathers of Christianity, you will indulge me, in her behalf, whose eyes have so lately closed, to repeat that appropriate form of devotion, " O, God, the Creator and Redeemer of all the faithful, grant to the souls of thy servants departed, but especially to that dear soul I pray for today, the remission of all their sins ; that through the help of pious supplications, they may obtain the pardon which they have always been desirous of, who livest and reignest, world without end. Amen. " Another principle, intimately connected with the foregoing, is that in case the departed Mary has already reached heaven, where she is perfectly happy herself, has she forgotten those she left behind ? No, certainly. But according to Scripture and the Primitive Church, there, still, inspired by that charity that never fails, she is praying for her parents, her nearest friends and relations on earth, perhaps for me ! Such reflections are by no means comfortless to those who on their return from the closing grave of one s^ dear to them in life, are uttering in deepest accents of sorrow, " Ye that have lost an angel weep for Miss A. S r, I am now one hundred miles below the City of Washington. In this county (St. Mary's) I find many most agreeable families.* The people here arc generally both wealthy and hospitable ; so that I find myself at home in every gentleman's house ; which often puts me in mind of my former friends, who, if they have forgotten me, it is my misfortune. Here I find not a family but such as are constant in reading, prayer and works of faith. These are the people whom you put down as idolators. I have been to view a very ancient Protestant church, called St. Mary's, by the side of which is a tomb which was some years ago opened, and the remains of the lady of Governor Col vert, alias Lord Baltimore, taken up after having been entombed more than a hundred years. Some curious laces taken from her last dress in the coflin, are now in possession of a lady with whom I have conversed on the subject. The town of St. Mary's, once the residence of the governor, and capital of the State of Marj'land, and where th's ancient church built in the form of a cross stands, is reduced to rubbish and ruins, there not being more than one or two houses in all the plain. Over the altar in the church are the images of Moses and Joshua. I find the principal part of the people here Catholics, who very strictly observe all the feasts and fasts as they arc put down in your prayer book. These certainly appear to take a great deal more pains and labor to secure their salvation than many among Protestants. Let me now turn to Mrs. D. and ask the following questions : First, in t'le Sacrament do you receive anything more than bread and wine ? If anytling more, what is it ? If nothing more, why receive it kneeling * Among the many families in St. Mary's County, to whose politeness and attention I shall ever feel the most ttnder obligations cf gratitude and thankfulness are the following, viz. : Smith, Dunkir.son. Clark Jones, Ford, Williams, McWilllams, Neal. Ploudcn Binnie, Combs, Medley Kilgour, Greenwel!, Taylor, Manning, Ilayden. These I ask once more to accept my thanks and best wishes. DANIEL BARBEll 55 at one lime more than another ? When Jesus Christ said, "This is my body and this is my blood," did He mean, this is not my body, and this is not my blood ? JMadamc, mast it not be considered a strange thing that Christ's words concerning the Sacrament were never rightfully understood, for the space of more than fifteen hundred years, even until Queen Elizabeth was made supreme spiritual head of the Church of England ; and not till after the first reformers had burnt to death these who denied the real body and blood in the Sacrament ? I add nothing mere, only beg you will reflect on the consequence of adhering to the wrong side in a doctrine so plain and important. Please accept my best wishes for time and eternity. Now, Miss A., taking it for granted that you are punctual in saying your praj'crs, evening and morning, give me leave to advise you to redeem half an hour each day, for the purpose of spiritual reading and meditation. Reflect often on death, it may be near, and on that world to which we are hastening. Give only small portions of time to amusements, and be careful to bring back with you an innocent mind. Never go abroad without first repeating the Apostle's Creed and Lord's Prayer. Be thoughtful in the midst of your pleasures, and from those things which are short and fleeting, collect something which may be durable. When you dance forget not the last dance, the dance of death ; as also sickness, old age and the last groans on a dying pillow. When dancing reflect how many have danced before you, and who arc now mouldering in the dust, or perhaps in their last agonies. Never forget to pray, "Lord Jesus Christ have mercy on departing souls." My friend, adieu. D. B. quality of missionary priest. The handful of Catholics who had been admitted into the church by Rev. Father FFrench, were soon gladdened by seeing their numbers increase. This was due to the influence of their own examples, to the exertions of that pastor, and also to the reading of the books given by Bishop Chevrus. They soon felt the need of a church edifice, and then there was the question of procuring support for the pastor ; for these early settlers were few and poor. In order to accomplish these ends Father Virgil went to Canada, and there obtained material help. With this help he began the construction of a church edifice, which is yet standing. He connected this building with the house in which he was born. The house was a large frame structure with good basement, and over the church proper there was a story to be used as a study modate several hoarders. These huildings we had the pleasure of visting a month ago (Oct. 1885). They are now much dilapidated indeed, yet to us they were objects of sincere veneration. Here it was that the first Mass in New Hampshire was celebrated ; here the sanctifying waters of baptism were poured on the head of Mrs. Daniel Barber and six of her children or grand-children, — perhaps the first baptisms administered in New Hampshire. Here many who were not of the fold were brought back into it by the exertions of Father Virgil Barber. In that frame house where he had been born the saintly Jesuit used to sleep on the floor. In the little church adjoining he would celebrate the holy Mass served by his venerable father, and administer Holy Ccmmunion to his dear parents and relatives.* As to the academy we have been told without inquiring about it, that it was one of rare excellence, and this we readily believe, for Virgil Barber had six years before, been president and chief teacher of a Protestant academy in the State of New York ; and again in the city of New York he and his wife had a very flourishing school. We know positively that the remembrance of him as a teacher is quite vivid about Claremont to this day, and it is worthy of note to record, that in that humble corner of New Hampshire he had prepared for their theological course such men as Fathers Yv'iley, Fitton and Tyler. These three pupils of Father Virgil Karberwere admitted by Bishop Fenwick in his own house in Boston and received their ecclesiastical instruction and training from the venerable prelate himself. In the records of Bp. Fenwick we find the following entry for 18th Sept. 1826 : " Mr. Daniel Barber, the father of Virgil Barber, arriving from Claremont on a visit to the Bishop, bringing with him Mr. Wm. Tyler, whom he introduces and recommends to him as a candidate for the ecclesiastical state. The Bishop is pleased with the progress made by him in his studies, and having received a good account of him on other points, admits him. Young Mr. Tyler is a relative of Mr. Barber, and has received the principal part of his education from Kev. Virgil II. Barber in his academy at Claremont. " The venerable Daniel B. must have felt much pleased when he saw his nephew admitted as a candidate for the priesthood. A few years later Wm. Tyler vras ordained priest, raised to the dignity of Vicar General of Boston, and finally was consecrated Bishop for the See of Ilartfort, Connecticut. Tlie first convert in Clarcmont, the venerable Mrs. Barber, departed life in the old homestead in 1825, receiving the last Sacraments at the hand of her admirable son. Rev. Virgil, undoubtedly in presence of her worthy husband. walks of peace and poverty. Yet he had at Claremont, children and grand-children whom he sincerely loved ; there was the grave of his dear wife, and the church and the school erected by Virgil. When his intention to leave his home became known to them, they failed not to express their sorrow at the prospect of his departure from amongst them, and begged of him to remain in Claremont. On this occasion it was that he addressed to them the following admirable letter which foims the last page of his book. (Catholic Worship and Piety). Your filial love and kind affection, expressed in your joint letter about the time I left Claremont, I accept v»ith the fondest feelings of tenderness and gratitude, It will ever serve to me as a cordial ; as a sweet remembrancer of your tender sensibility, which prove to me the joy and rejoicing of my heart. This choice memorial of your love to me, and best wishes for my comfort and happiness, I shall lay by me in safe keeping. I shall carry it vrith me in my retirement, relying on its spirit and influence to console and cheer me under the wounds of disappointment, pain and sickness, by teaching me how to bear all things, and hope for nothing but what it may please God to send. "You must be sensible, my dear children, that seventy years have been separating me more and more from everything on earth, once seeming as dear to me as life itself. The once tender-hearted friends and best companions of my juvenile j'ears, that favorite season of human life, have forsaken me — they have gone ; my wishes and imagination seek them in vain — they arc not ! Their names only may be found on cold marble monuments, here and there erected to point out the spot ; saying, or seeming to saj^ — there lies the once fond mother — and there the child of joy and sorrow. The fond lonely remembrance excites the involuntary tear, while the heart labors to heave another deeper sigh. " I look back again to the pleasant scenes of early life. Here is one object ever presenting itself to my recollection ; it is her who once, and for many years, was the kind associate of all my cares, my hopes, and wishes. Yes, for many a year we travelled the rugged path of life together ; and at a time too, when the looks and smiles of our helpless little children, dependent on us for their comfort and protection, called into exertion every principle of care and activity. Our anxious desires for the future happiness and prosperity of these, gave a pleasure to our toils, our labors and sufferings ; our hearts comforting us at the same time, with the fullest assurance that these same little ones, at a future time, would add greatly to our happiness by supplying our wants, if needy, consoling our declining years, and wiping away for us the tears of sorrow and old age. " Such were once the joys — the comfort, the hopes, which sweetened all our cares, and made life itself delightful. These were my happy days ; and these, in a temporal sense, formed the happiest period of m}^ life. That period, hovv^ever, was short ; it is past — it is gone — gone to return no more ! Every fond prospect smiled at a distance, and anticipation from the threshold of her various avenues, claimed attention to her syren song — scon the curtain drops — fancy gives place to reality. Upon close inspection, the beauties once admired are seen to fade and every earthly charm loses its chiefest delight. " This, my children, is, has been, and ever will be the case of the world and its votaries. Nothing here is stable — nothing substantialnothing on which we can rely for the present and future happiness, but God and true religion. Trials, of one kind or another, you may reasonably expect during this term of your mortal pilgrimage. Was it always sunshine with the saints on earth ? How many a weary pilgrim has carried the sign of his faith through good report and e\il report ! Take these for your guide ; these heroes— these champions of Christianity— and follow them on to victory and glory. They were men obnoxious to the same passions that we have to contend with ; they had their temptations, and their trials, to withstand ; and the same grace which was given them is offered to every one of us, and by it we may overcome. "My dear children, be not only steadfast in the faith, but persevere in every Christian duty. Life is short, and soon will its trials be at an end. In this world we often part and meet again. Whenever we shall arrive in Heaven, there will be no more separation ; it will be our permanent abode, a habitation of everlasting joy and rejoicing. " I am sensible, my dear children, that I leave you sorrowing, and with the fearful apprehension that I shall iinish my earthly course soon, and find my grave in the land of strangers. Where we die is of little consequence ; to be prepared is the main thing. Still, to depart in the midst of friends, and in the l)osom of onr family, is a reflection soothine: to the human feelino-s. Home and friends have their worth and estimation ; but, when death approaches what can these do ? They can shed the tear of sorrow at our bed side, and offer their prayers for our comfort and the consolation of the Spirit. To know the worth of these, ask death-beds ; they can tell. " And to conclude, v,diether I am present with you, or absent from you, my prayer is, that you live in peace and love, striving together in the true faith of the gospel. And, when the last trumpet shall sound, and dissolving Nature utter her last groan, then may you be enabled, through faith in Jesus Christ, to stand secure on the ashes of the Universe, and exclaim, ' I have lost nothing. ' " The only reliable information we could obtain about the life of Rev. Daniel Barber after he left Claremont, came through Rev. R. W. Brady, president of Worcester College, who himself kindly wrote for information on the subject to some of the other members of the order. He writes : "I think there is no doubt that Rev. Dan. Barber had a home with us on account of his son Virgil, and on account of the circumstances of his family. He used to have the privilege of going from one house to another of ours in Maryland and Pennsylvania. " He used, when he came south, to spend some of his time in Washington, visiting and remaining a few days with several Catholic families. I remember having seen him at my father's in Washington. I remember he having said his beads or read his prayer book telling the members of the family to chat on and not mind him. (Fath. W. C. Clark to Father Brady)."* Old Father D. Barber loved to visit the old Catholic families of St. Mary's Co., Md., but was ill pleased when he did not find the cross, the sign of our salvation, in the department. * Where is your sign ? ' he would abruptly ask. He died in 1834, at St. Inigoes, Md., aged 78 years, and was buried in the cemetery of that mission house of the Jesuits. His last words were an expression of sorrow for having preached heresy 30 years, and a fervent prayer to the blessed Virgin Mary, It must be conceded that of all the converts to the Catholic Church in New England, there is not one (Mrs. Barber being excepted) who sacrificed so much for the sake of honoring God and saving his soul, as the subject of the following memoirs. Rev. Virgil Barber by becoming a Catholic not only lost his property and position in society, as he knew well he would, but he voluntarily separated from his accomplished wife, at the age of thirty-four, and from his children, five in number, of whom the youngest was only ten months, and that in order that he might lead a life of perfection by the observance of the perpetual vows of chastity, poverty and obedience in the austere order of the Jesuits. Heretofore very little has been known about the conversion and labors of Father Barber. Through the very great kindness of the Most Rev. Archbishop of Boston we have been permitted to examine the Records or Memoranda of the Rt. Rev. Bp. Fenwick, and were much surprised and delighted to find a full and satisfactory history of the wonderful conversion cf Virgil Barber and wife, written by that eminent Prelate. The Right Rev. Bishop wrote that history in connection with his first visit to the Catholic Congregation at Claremont, New Hampshire, of which Rev. V. Barber, S. J., was the pastor at that time. No one was better qualified than Bishop Fenwick to write the life of this remarkable man, for he it was who had baptized him, his wife and family, at New York, when he was Administrator of that Diocese and not yet a Bishop. Bishop Fenwick encouraged Virgil Barber and his wife to aspire to a high perfection, and enabled them to accomplish their earnest desire to separate in order to enter a Religious life. During all his life Bishop Fenwick, whom Bp. Fitzpatrick styles one of the best and most virtuous of men, ceased not to interest himself in every member of the Barber family ; and his sketch of the career of Rev. V. Barber, which now appears, we believe for the first time, will be read with much interest. The anecdote of St. Francis Xavier's book, which had so much influence on the subsequent life of Father Barber, \vas communicated to us from Three Rivers, Canada. Some entries made at different times in the book of memoranda of Bishop Fenwick have given us some more information about the hfe of our venerable friend ; but we are particularly thankful to Sister Mar}^ Josephine, of the Visitation Convent of St. Louis. She is the youngest and only surviving child of Rev. Virgil Barber. Through her kindness, and with the approval of her Reverend Superiors, we have been enabled to place before our readers copious extracts from the JMemoirs she wrote about her father. These Memoirs, together with some of his letters, v>-ill be found full of interest ; and in the biography of her mother, which will follow this compilation, the reader will find many unpublished accounts which throw yet more light upon the subject of these Memoirs. OF THE SOCIETY OF JESUS. "To see my dear family my most and only precious treasure on ear' h, possess the gisace to despite the world and the vanities of time, and live oniy for eternity, leaves me without a wish, this side of the grave."'— Yiegil Barber. When Right Rev. Benedict Fenwick arrived in Boston in 1825, he found " a small brick church in Claremont, New Hampshire, erected by the exertions of the Rev. Virgil H. Barber, who now officiated in it. The Catholics who attend it for divine worship are almost entirely con • verts to the faith within these five or six years past. They are, to the number of about one hundred and fifty individuals in all, scattered over a district of ten or fifteen miles." " The Bp. sets out for Claremont, Kew Hampshire, in order to administer the holy sacrament of confirmation to the congregation under the charge of Rev. V. H. Barber, whose church he had promised to visit at this time. ther excessively warm. June Iftli. The Bishop celebrates Mass and gives confirmation to twenty one individuals, male and female, having previously addressed them on the sacrament and the dispositions for worthily receiving it. The church is greatly crowded ; the greater part assembled are Protestants from the church on the opposite side of the village which they have completely deserted, to the very great dissatisfaction of the Minister there attending. From the impossibility of all entering the church many occupy the rooms, belovv' and above, of the house adjoining, and strive through the doors and windows to catch a view of what is passing ; and a still greater number line the street and occupy the ground next to the side of the church, unable to approach nearer for the crowd. This anxiety of the Protestants of this neighbourhood to observe the ceremony on this occasion will not surprise when it is recollected that it is only a very few years since the Catholic religion was introduced in Claremont— that before that period the grossest ignorance prevailed ItEV. VIRGIL II BARBER. 63 among the people in regard to the tenets of Catholics, and the strongest prejudices existed, and that even now, thongli much care has been taken to undeceive them a disposition among the greater part exists not altogether favorable to the growth of catholicity." Whilst noticing the proceedings of this day in this section of the Diocese, it may not be improper to leave some account of the establishment of the Church at Claremont, and particularly of the conversion of its founder, the Tie v. Yirgil H. Barber. The Bishop first saw and became acquainted with the Eevd. Mr. Barber in the City of New York in the year 1816. He was then Administrator of that Diocese sede mcante, and the Rev. Mr. Barber occupied the situation of Principal of an Academy in the upper part of the State, about 15 miles from Utica. It was in one of his visits to Kew Yorli he took occasion to call upon the Rev. Administrator and to enter into conversation with him upon the subject of Religion. He was open and candid in his remarks, and seemed to manifest a sincere desire to know the truth. The Rev. Administrator was equally free on his side, and took some pains to satisfy him in his inquiries, and to explain to him the real doctrines of the Catholic Church, satisfied that if he could but remove the prejudices of his education, he should find but little difficulty to convince him of the truth of the Catholic religion. In the course of the conversation the Administrator learned who he was and the situation he held : he became accordingly doubly anxious to gain him. After some time spent in discussing various matters, the Rev. stranger manifested a desire to retire, but requested at the same time permission to be allowed another interview at som.e 'future day : which was readily assented to. The Administrator took the opportunity of putting into his hands several books, v/hich he requested him to read in the mean time ; and on his return, should he find any passage in them that wanted explanation he would with pleasure give it— earnestly entreated him to pursue his investigation, assuring him that if he was sincere in it, of which he did not entertain the least doubt, God the Father of light would undoubtedly lead him on to the truth ; and recommended to him to have frequent recourse to Him by prayer. All which he promised, and took an affectionate leave. Some months elapsed before he returned, he having shortly after set out upon his journey home where he remained wholly engrossed by the cares of his Academy. That he had in the interim many debates with himself in the enquiry he was m.aking and to struggle hard against the power of habit no one can doubt, who has any knowledge of the human heart, and the prodigious hold which habit, backed by strong prejudice, takes upon it. Mr. Barber had, besides, many reasons of a worldly nature which have no small influence upon the generality of mankind for remaining in the religion in which he then was. He was the principal of a flourishing Academy, which bid fair in process of time to become a College, agreeably to the law then in force relative to the establishment of colleges; he was also the Pastor of a congregation, which two officer secured liiin a handsome living-. His prospects, especially in (lie Academy, had induced him to make a purchase of land immediately in the neighborhood which, thouo-h not really valuable ;i( that time, would become so if he continued to manage the Institution of which he was Principal. " If he embraced what he deemed to be the true religion, he would certainly lose his present situation as well in the Academy as in the church, and what would he obtain as an equivalent ? Nothing certain. Not even had a promise of anything been made to him. Should he then go and lose by the step he was taking, a certainty for an uncertainty, and expose his wife and children to beggary and want ! Human and worldly prudence naturally forbid it. He was yet not ciuite sure that the Catholic Church was the only true church, although everything as far as he had yet gone into the investigation, seemed to allow it ; yet it might not be — other churches might also be true churches, and among tliese his own. Why, therefore, should he go by a precipitate step and jeopardize his family ! Could he not remain as he was until he should at least realize a sufficiency for the support and education of his children ? And if hereafter he should be perfectly convinced, after a full investigation, that the Catholic Church is the only true church, wdiy he could then embrace it without hazarding his worldly prospects !" This and such like might have been the train of his thoughts during this interval, and upon ten thousand individuals they might have had their influence, wdiom, if they did not wholly withdraw from the enquiry, might at least have had the effect to interrupt and postpone it. But Mr. Barber was not ro easily to be turned aside. He had read and learned enough to know that the religion of which he was a minister was not a sure one to arrive at heaven — he had read and learned enough to have the strongest doubts of its truth. This was enough for him, who, in sincerity sought the truth, to persevere and not to stop until he should find it, and having found it, to embrace it, whatever might be the consequence to his worldly prospects. He accordingly took another journey to New York. The Administrator recognized him as soon as he entered the room, greeted him in the most cordial manner, and enquired affectionately into the state of his health and that of his family. After a few moments desultory conversation, the former subject was renewed and much ground in religious controversy w^as travelled over in the course of a few hours. Mr. Barber in the course of the conversation admitted that the Protestant faith could not be defended, and seemed greatly at a loss what to do. The situation of his family seemed to rush upon his mind, and the the Administrator, guessing at what passed within him, "trust your affairs to the management of a heuiScent Providence. Embrace the truth, now that you liave found it, and leave the rest to God. Ke has led 3"0u on to make this enquiry, he has followed you step by step ; and now that you yield to his grace he will abandon you ? Xo, believe me, you were never more secure of subsistence."' " '\Vhat shall I then do ?" he replied. '' First embrace the Catholic religion," said the Administrator, " then go back to your Academy, resign your situation in the Episcopal Church, settle your affairs as seen as you conveniently can, and ccme to Kevv^ York, I shall in the mean time use my best endeavors to procure you scholars ; so that as soon as you arrive you may open a new school, which shortly I hope to sec as flourishing as was the one you forsake." " Well, I submit," vras the generous answer returned. "I am ready to give in m_y recantation whenever you may deem tit, and to do vvhatever else you shall prescribe." A few days after, he made his recantation, read the profession of Catholic faith, was baptized (sub conditione), made his confession, and was regularly received by the Administrator into the communion of the Catholic Church. Upon this, he immediately returned heme where he set about arranuing his affairs — informed hisccnoreiration of the change he had undergone since he saw them last, and bid them a tinal adieu. As he had loEg anticipated, so it happened. His parishioners all, to a man, turned against him ; soon deprived him, by their interference, of the situation he held in the school ; and finally concluded their persecution by forcing the sale of the. land he had some time before purchased, but for Avhicli he had not entirely paid, and v.hich in consec]uence was sold to great disadvantage. Not long after this proceeding the Administrator received a letter from Mr. Barber in which he acquainted him with what had passed since his return home, and informed him cf the arrangement he had made and of his determination to leave the country and accept cf his invitation to Xew York The Administrator lest no time in replying to his letter, and telling him that all was ready for him — that a house w.'is procured in a central situation — that scholars were premised, and what bid fair to be of considerable service to him, that the gocd feelings of the Catholics were all enlisted in his favor. ]\Ir. Barber shortly after arrives, bringing with him his wife and interesting little children, five in number, one boy and four girls. The Administrator receives them with open arms, causes them to remain in his own house until he had seen all things in order, as far as circumstances would allow, in their future abode. He considered that as one of the happiest days in his life, in which he had received and entertained these martyrs of the faith. ]\Ir. Barber having moved iDto his new house, immediately opened school, Avhen a number of children, some of whom were of the most respectable families, flocked to him for instruction, Xcr did he neglect in the mean time to prosecute his studies in religion. He was well aware that though he was now a Catholic, yet he had much to learn before he should be fully acquainted with all the principles and practices of tlic Church. His first care was to bring over Lis good lady into that way which he now knew to be the true one, and to cause all his children to be baptized like himself sub conditions. It was not long when Mrs. Barber likewise offered herself to be received into the communion of the Church. Naturally pious, she had offered little or no resistance to the abundance of divine grace. It was now truly an enviable family, and Almighty God seemed to delight in blessing them in every particular. For some time things continued in this state, the school progressing and receiving daily an accession of scholars, from the high opinion parents began to entertain of the talents of the teacher and his experience in the art of instructing. His attention, however, was not v>'holly directed to his school : his leisure hours were taken up in studying and instructing himself in the science of the Saints. He had scarcely made, together with his good lady, his first communion ^^ hen he began to aspire to a very high degree of perfection, viz : that of devoting and consecrating himself entirely to the service of God. He thought the Almighty had a further claim upon him, for having, through his very great mercy, brought him to the knowledge of himself and his true church, and required something more of him than to edify simply his neighbor in the state of a layman. He was aware that great obstacles lay in his way which seemed to forbid him even to entertain a thought of the kind : but then he knew also that hn who inspired him v/ith the thought could, (if such were indeed his holy will) easily remove these seeming obstacles and enable him to accomplish the object. Before he opened the subject to any one he spoke with his wife and consulted her thereupon. God had already prepared her by his holy grace. The reading of the Lives of the Saints and the heroic examples of so many blessed servants of God in all ages had already filled her with a noble ardour to emulate their virtues. She readily assents to all, and is equally anxious to carry into effect so laudable a design, if prudently practicable, " She knows not whether such a thing is allowed in the Catholic church as the separation of man and wife for the purpose of enabling the former to enter into orders She takes the first opportunity to consult the Administrator on the subject, assuring him at the same time " that if the matter can be accomplished with justice to the children, she is every way desirous of it." The Administrator is per- fectly astonished — he knows not how to view the matter, or in what light to consider it. Upou her pressing him to say "whether he knew or had read any example of the kind in the church, or whether the Church approved of such acts of consecration to God ?" he replied in the affirmative, stating that he had read of several instances of the kind and especially of Lord and Lady Warner, two distinguished persons in England, of whom both had been brought up Protestants, but who afterwards were converted to the Catholic faith ; and afterw\ards, by mutual consent, were separated, when the husband studied and became a priest in the Society of Jesus, and the wife took the veil in a convent on the continent. They had, moreover, two young daughters to be provided for ; but these, previous to their separation, they had placed for their education in a convent in the Low Countries, appointing proper guardians and giving up their whole estate to them as scon as they should come of age, or in case they should not, like their pious parents, have a call from God and take to religion. But the Almighty so disposed matters that they both took the veil and entered into a convent at Dunkirk. The Administrator informed her furthermcre that the Church never prevented married persons consecrating themselves to God in holy religion, if it were done with mutual consent, and if proper provision were made for their children and they should be well taken care of, in case God had blessed them with any. But for the present he dissuaded her from thinking of the matter, principally on account of her children, who had no other means of support than their parents, and who, if a separation were novr to take place, wculd necessarily suffer ; and therefore a separation under such circumstances, no m.atter for how laudable a motive, would in no manner be justified." In consequence of the, arrival of the new Bishop of New York, (Dr. Connelly) shortly after this, the Administrator was recalled to Georgetown College to take upon him the direction of that institution. On his departure, which took place after the Easter Holidays, he recommended in the strongest terms Mr. Barber and family to the worthy Bishop, beseeching him to have an eye to them and not to suffer them in any manner to be neglected. The Administrator, obliged to obey the call of his Superior, regretted nothing so much on leaving a City where he had lived the last ten years and which had been his first mission after ordination, as his being compelled to desert a family whose welfare he had so much at heart, and whose interests he was afraid would not now be attended to. A perfect stranger in the place, under a Bishop who was equally so, without a friend and with a growing family, without resources and with many calls, having nothing to depend upon but his school which, in a City like Xew York is so precarious a thing, the Administrator felt greatly for him. He had it no longer in his power, as he tliouglit, to do anything for them ; he could therefore only recommend them to God and to him whom he had established in his place the father and protector of the poor. But tlie Almighty had Resources which the Administrator knew nothing of, and ways and means too of af:sisting them, which he could not forsee. IIow admirable is the Providence of God ! and hoAv wisel}^ does lie dispose all things to bring about the object he has in view ! Had the Administrator been suffered to continue in New York, in all probability ]\Ir. Barber would have continued there also ; and had he not been recalled by his Superior to Georgetown, he never could have found the means of providing for and educating the children of that worthy man, and thereby furthering the plan he had, in common with his virtuous and amiable wife, so dear at heart. But by his recall all was accomplished. But a few weeks had elapsed after the departure of the Administrator (for so he is still to be called, though no longer administrator, merely for the sake of the narration) and his arrival at the College, w^hen he received a letter from Mr. Barber recalling his attention to the former subject of conversation, and enquiring whether something might not be done for him there. The Administrator held as yet no situation or office in the college, but he possessed some influence with its then President, the Rev. Mr. Grassi, Superior of the Jesuits in America, as well as with the Archbishop of Baltimore, Dr. Neale, who at that time resided at the Visitation Convent in Georgetown. Knowing the ardent desire which both Mr. Barber and his good lady had to consecrate themselves to God in holy religion, and aware of the obstacle in their way by their having five small children to provide for, and willing to serve him to the best of his power, he began to reflect and consider how to dispose of these helpless children ; and whether some arrangement might not be made in their behalf, so as to leave their parents quite unincumbered. With this view he first called upon the President of the College and laid open to him the whole business, stating the situation of Mr. Barber and that of his family, his conversion as well as the conversion of his wife, and their extreme desire to separate for the sole purpose of entering religion, etc. That above all things he wished to be united to the Society of Jesus of which he had heard and read so much, and v/hose holy institute he admired ; and pressed him in the most earnest manner to favor his design by admitting him as a novice and his little son, then about six years old, or perhaps not so much, as a pupil, into the college, to remain until completely educated. The Reverend Superior, struck at the heroism of Mr. Barber and the gracious sacrifice he proposed to make of himself to God, and wishing at the same time to exhibit so striking an instance of the power of divine grace, to a wicked world, instantly consented and authorized the xidministrator to make the same known to him as soon as convenient. Having succeeded thus far lie next proceeded to the Convent of the Visitation to confer with his Grace, the Archbishop, about Mrs. Barber and her other chiklren, viz : the four remaining daughters. Here he expected quite an unfavorable answer ; but slill he trusted in God. The convent had been but just established— its number was, however, great and its income i-mall— scarcely suthcient to support those already admitted. Besides the number he intended to petition for, was too great, even were the convent in far better circumstances, viz : a mother and her four children. But no matter, he resolved to try, and to persevere. He accordingly entered the Bishop's apartment and immediately introduced the subject. He spoke of the great charity he would confer by receiving them into the convent and how likely such a step would draw a blessing upon an infant institution— expatiated a good deal upon the merits of Mrs. Barber, her piety, her desire of perfection, her talents and acquirem.ents, and how useful she might prove in an establishment where the object wr.s in a great measure to educate female children. The Administrator f nally concluded with assuring him that he entertained no doubt that God would hereafter amply compensate for any expenses the house might incur on their account. The Archbishop during the whole time seemed to listen with much attention. On the one side, his benevolent disposition inclined him to offer her the Convent, on the other his prudence dissuaded him from it. The absolute want of funds on her part to defray any part of the expenses of the children appeared to w^eigh very much upon him. He wished not to impose a heavier burden upon the good ladies of the Convent than they could conveniently bear. " Really, " he said at length, " I am much at a loss what to do in this matter. I fear it will be impossible to admit her, not precisely herself, for we might compass that ; but her children, what should we do with them ? " "Educate them," replied the Administrator. ' ' Ay " immediately answered the Archbishop, " that is easily enough said. But who is to support them in the mean time and to defray the expenses of their education ? " Dcus providebit. The widow of Sarephta was but in indifferent circum.stanccs when the prophet Elia called upon her for a little bread— scarcely had fjhc a handful of meal at the time ; yet she made him, at his request, a cake of that meal ; and the consi'quence was a great blessing upon her ; for from that day, says the Scripture, the pot of meal wasted not, in her house. " And will God, thanks your Grace, continued the Administrator, bless less the charity bestowed by the children of his own election, than he did that bestowed by an infidel Avoman ? " "Well, well, well," answered hastily the xVrchbishop, " be it so, be it so ; we shall see, we shall see. But I cannot consent to take the infant she has at her breast, (the Administratcr liad given him in the course of conversation, the age as nearly as he could recollect of each of the children) what should v,e do with that ? " " As to that, " replied the Administrator, " the dear little creature shall not want a home when the others are provided for. My mother shall take charge of her, and shall nurse her as if she were her own. But at a proper age your Grace will receive her too into the school of the Convent. " " Very well, " he replied. . Thus was this important matter settled, greatly to the joy of the Administrator as well as to the credit of the Archbishop and the Superior. The Administrator immediately gave information of what had passed to Mr. Barber ; and invited him to lose no time in coming on. Accordingly in a few^ WTeks after, he arrived with his whole family — was received in the college hall by the Tvcv. Mr. Grassi, the Superior, by the professors and by the Administrator w-ho all exprer.sod the liveliest joy upon the occasion. After some days rest from the fatigue of their journey the pious couple were taken to the college chapel where the Archbishop in the presence of a number of individuals, both clergy and secular, pronounced the divorce, having lirst ascertained of themselves individually their full consent thereto. He gave an eloquent Admonition on the occasion which drew tears from the eyes of many who WTre present ; and concluded by recommending them to continue faithful to the grace of the Lord, and to persevere in that perfect path he had traced out to them. They were then dismissed. Mr. Barber vras conducted to the room which had been prepared for him ; his little son was taken into the college ; Mrs. Barber with three of her daughters were conducted to the Visitation Convent and little Josephine was cordially received by the Administrator's mother. In the course of afev/ months the Rev. Mr, Grassi having occasion to go to Italy, resigned his situation in the college in favor cf the Administrator, It was determined in council that Mr. Barber with three of the more promising Scholastics should accompany him, in order that he might have an opportunity of seeing Catholic countries, and especially Rome ; and that they might complete their education in the Jesuit College there. In a short time they set sail and after a prosperous navigation, all reached Italy in safety. They immediately repaired to Rome, where they were received in the most friendly manner by the Jesuits and not less kindly by the then Sovereign Pontiff Pius VII, of happy memory, to whom they were presented by one of the Fathers. Mr. Barber, after an absence of nearly a year, during which time he principally lodged at the Jesuit College at Rome, returned to this country, and commenced his studies in theology at the college in Georgetown, which he prosecuted with ardour until December, 1822, when he was sent by his Superior (for be was already admitted to liis vows and received into the ccciety) to Boston, where he was ordained priest on the feast of St. Francis-Xaverius by the Administrator's worthy predecessor (Dr. Cheverus). Mis, Barber had some lime before this, taken the veil in the Visitation Convent at Georgetown ; where she still continues an example of patience, cf humility, of obedience and of every religious virtue, enjoying the happiness of seeing all her daughters (little Josephine included) successively improving in virtue, knowledge and every polite accomplishment. The conversion of the Rev. Mr. Barber (for so he must now be styled) was not without producing in a very short time the happiest results. It led the way to that of his aged father who officiated as an Episcopal clergyman in the town of Claremont, State of New Hampshire, and of very many others as well of strangers as of his own kindred. His father, Daniel Barber, was among the first, after he heard of his son's conversion, to enquire. He took a journey to Georgetown, and there became scon convinced of the truth of the Catholic religion. He continued some time in Washington to learn and to strengthen himself in the faith ; and afterwards returned to Claremont, where he formally renounced the errors he had embraced, in the church, where he had so long presided as pastor, a. The Kev. Virgil Barber after receiving ordination as above mentioned, by the hands of Bishop Chevcrus immediately repaired to Claremont with the approbation cf the Superior and began to labour towards the conversion of the Protestants in and about that neighborhood. With the aid of his father and the charitable contributions of the clergy and laity in Canada he laid the foundation and soon raised the neat little church which now distinguishes that section of the countrv. h. In order to secure a sulsistence without being a burden to his little flock he opened a classical school which scon attracted a number from different parts. Thus did the Vvxrk progress by degrees. And the Lord increased, dally ioreihtr such as shoidd he saved. The faith has taken deep root ; and it is now a growing congregation v.hich in process of time, with the continued exertions of its excellent pastor bids fair to become not less numerous than respectable. The Bishop at his visitation was iiighly gratified with the fervour and zeal displayed by all, and hopes much from influence of their edifying example upon others. The following additional details connected with the conversion of Father Virgil Barbor will be read with much interest. When this zealous convert came to Canada in order to obtain help towards building a church in Claremont, he said in substance to the Right Reverend Bishop Cook of Three Rivers. (He was then Parish P. of Three Rivers, a): "I had in my house," said Rev. Y. Barber, ''a ,^ood Catholic Irish servant girl, whom I often noticed using a certain prayer book. I was then a Protestant minister, but I w\as sincere. A happy curiosity which was undoubtedly an eifect of divine grace, made me open and examine that little book which proved to be a Novena io St. FrancisXaiiiv. I was very much impressed with the abridgment of the life of the Saint which was contained therein, and I thought I must try and get a complete life of that w^ondcrful missionar3\ I acted upon this idea, and after carefully reading that life so remarkable, I had to say to myself : Behold a man .who lived at the very time of the Protestant reformation ; "-' one therefore who lived so near our own times that his existence cannot be a myth. This life being so remarkable must have excited the attention of the learned, as soon as it came out in print, and was scattered everywhere. No one has contradicted it, and this would surely have been done, had the history of St. Francis-Xavier been untrue. It has moreover all the marks of authenticity and veracity which can be desired. How^ could a religion which forms such men, be a mere humin institution ? Peace then departed my soul. I had doubts concerning the truth of my Protestant faith. I began to study very seriously, and the more I studied the more my doubts increased. These doubts I submitted to my Bishop ( Dr. Hobart ) hoping thereby to find peace ; but he gave me no light on the subject, and rather strengthened my doubts, as he paid no serious attention to my objections. We were at this time standing at the window of a room whence we could hear the singing going on in a Catholic church near by. I tcok occasion to ask the Bishop : ' Do you think that those can be saved ? ' At this question of mine he could not help smiling, and answered, ' They have the old religion. Don't you know ? But they do too much, and one can bo saved without so much trouble. Do not trouble yourself about such matters. I returned home from that interview more disquieted than I was before. I put down on paper my objections against the Protectant religion in the shape of fourteen questions and invited many ministers of the Episcopal church to come and visit me. To each of tliera as they came in, I presented this terrible sheet of paper. They all glanced at the questions, and none failed to say : " Well, vrcll, we will see after tea, " but after tea music was had at the piano, and as no one attempted to answer the questions, I then resolved to see and consult the Bishop of Boston. " (That is Father Benedict Fenwick of New York, afterwards Bishop of Boston). Episcopal ministers. In the sketches of the establishment of the church in New England by Father Fitton, we read, p. 283 : " The conversion of Rev. Father Barber was not without producing the happiest results otherwise, as it lay the way to the conversion of Rev. Dr. Keeley, an Episcopal clergyman, and rector of St. George's Chapel, New York, and of George Ironside, also a member of the Episcopal church, of Rev. Calvin White of Connecticut, and others. " The following entries in Bishop Fenwick's Memoranda gives us some information about Rev. V. Barber, and show the interest he entertained towards him and his family : Nov. 23, 1820. " The Rev. Virgil H. Barber arrives (at Boston). The Bishop prevails on him to visit those pa^ts of the Diocese which are destitute of pastors, viz : Dover, Bangor, Eastport and such other parts in that direction, as have any considerable number of Catholics. He particularly recommends to him the two tribes of Indians in Maine. He hopes this journey, undertaken by that pious and zealous clergyman, will produce the happiest effect, by affording the scattered Catholics an opportunity of receiving the Sacraments, and thus preparing them for the grace of confirmation, which it is the intention of the Bishop to confer next summer in his visit through the same places." December 11th, 182G. "The Rev. V. Barber returns from his mission and gives the most flattering account of his reception everywhere by persons of other denominations, and of his success among the Catholics, dwells particularly on tlie favorable prospects at Dover and the great desire of all classes to have a Catholic church erected there. He is of opinion that the object can b3 effected, and that a considerable sum of money is already subscribed towards it, and when this is accomplished the means of supporting a priest will be amply sufficient. He speaks too of the great piety that prevails amongst the Indians of both tribes, and laments that there is yet no priest among them . " (Bp. F., Memoranda). 182G. Among the events occurring during this ycr>r Bishop Fenwick mentions : " The admission of Miss Mary Barber, eldest daughter to the Rev. V. H. Barber, into the Noviciate among the Ursiilines in their new establishment. Her sister Abby, who came Avilh her from the Visitation last spring, after a short delay in Boston, continued on to Quebec, where she arrived in safety, and where she also "is received as a novice in another convent of the Ursulines. Thus has a part of the family of this worthy couple already commenced to walk in the foot steps of their pious parents, and every appearance exists that their example will produce a similar effect upon the remaining younger ones, when they shall have obtained an age to judge and decide for themselves. " (Bp. F., Mem). Shortly after Father Barber's return from his mission in Maine on 'Jan. 12th, 1837, ''The Bishop receives a letter from the Superior of the Order of Jesuits at Georgetown, D. C, informing him that he has recalled the Rev. Virgil II. Barber from his mission at Claremont, to the College of Georgetown and has directed him to lock up his church at the above mentioned place, until another pastor is sent by the Bishop. The Bishop is seriously grieved to hear this news, especially, as he has at present no one to send in his place, and the rising congregation there will be for a time left destitute. " On Feb 21st. " Reverend Virgil II. Barber arrives in town, in pursuance of the orders of his Superior at Georgetown, on his way thither. He delivers the keys of his church at Claremont to the Bishop, and acquaints him with the present state of things there. The Bishop regrets very much the loss of this active missionary to his diocese, the more as he has at present no one to substitute in his place. The little church at Claremont will accordingly have to remain without a resident pastor, till another can be provided. " Reverend Virgil Barber left Boston for Georgetown agreeably to the order of his Superiors a week after his arrival in the former city. The Bishop, however, had already written to the Superior at Georgetown soliciting him to leave Rev. Mr. Barber in his diocese for a somewhat longer time, and expressed a hope to obtain him yet of the Superior of the Jesuits for the Indian missions in Maine. The request of the zealous Bishop was granted. The Superior at Georgetown was kind enough to allovv" Rev. Mr. Barber to continue in his diocese, and to become missionary among the Indians in the State of Maine. missionary was back in Boston, celebrated High Mass at the Cathedral, and in afternoon of the same day preached, " and in the course of his instruction delivered some pretty remarks to the children who were confirmed in the forenoon." On the next day at 3 P. M., the Rev. Virgil Barber ' ' sets off in a steamboat to Portland on his way to his mission among the Penobscot and Passamaquoddy tribes of Indians. " Bishop Fenwick here exclaims : " May heaven bless his endeavours ! " Rev. James Fitton was appointed as assistant to Father Barber, the now missionary of the Penobscot and Passamaquoddy tribes of Indians, Father Barber residing at Indian Old Town on the Penobscot, and Father Fitton at Pleasant Point, among the Passamaquoddy tribes of Indians. Almighty God blessed abundantly the labours of these devoted missionaries, and Father Barber informed the Bishop that the Penobscot Indians were doing well ; that in the course of the last year (1828) a store house had been built for them and materials had been provided to build a church the following spring ; that the school had been regulary kept up and the Indians were united. Reverend Father Barber paid a visit to his old parishioners in Claremont in the beginning of February, 1829. The news that he brought back to the Bishop were not favorable. " The good people there were very desirous to have a priest, but were unable to support him." We easily imagine that the zealous missionary would have been quite willing to return to Claremont, a spot rendered dear to him on so many accounts, and to start anev,^ his academy ; but providence willed him to labour elsewhere ; and on Feb. 16th, 1829, he set out to return to his mission at Indian Old Town, intending on his waj'- thither to visit the governor and council of the State of Maine, for the purpose of obtaining salary for his support as teacher among the tribe, and of arranging other matters connected with the agency. A few months later he was recalled from Maine by the Superior of the Jesuits Order in Georgetown." surviving child of Rev. Virgil Barber. Stationed in his native town (in 1823 and 1824) Rev. Virgil H. Barber began the erection of a small Catholic church and seminary contiguous to the family residence, and nearly opposite the oft-frequented Protestant parochial meeting house on the other side of the road. I will quote again from Father Fittou's letter : " I have still a vivid recollection of your grandfather Daniel, his aged wife, son Israel and daughter Rachael. Mrs. Tyler also, with her husband, sons and daughters, (Sisters of Charity) not omitting my dote I could tell of the early days of catholicity at Claremont. " Not forgettinir Cornish— the house of Capt. Chase and sister, especially, whom previous to their receiving the grace of faith, I was accustomed to regard as the corner stone of Calvanism ! and there were the Marbles, Holdens, &c., all related to the Church by the footprints and untiring zeal of your own sainted Rev. Father, even of wiiom I must tell a secret. When his seminary was in full progress and the house adjoining was occupied by students, my curiosity was to know% if he ever slept, where did he sleep ? And behold ! I found his bed to be a strip of narrow carpet on the floor, which was privately rolled up by day and hid in the closet." sequies. Xews now reached Xew England that Father Fenwick, the same who had received him into the church, was nominated to the vacant See of Boston. Great was the joy of my father on learning that his former friend vras to assume the government of the Diocese. He went on to Maryland to be present at the consecration, wdiich took place in the Cathedral of Baltimore on Nov. 1st, feast of All Saints. After this he accompanied Bishop Fenwick to Georgetown, where, with my mother, they made arrangements for the future location of myself and sisters in the Ursuline Convents of Boston and Canada. This done on Nov. 1st, 1825, my father made a farewell visit to his wife and children (at the Visitation) wdiom he met all together for the last time ; and on the morrow, in company with the newly consecrated Bishop of Boston and Dr. England, Bishop of Charlestown, S. C, set out for the north. They reached their destination on the feast of St. Francis Xavier, (Saturday) and on the fourth, Sunday, Bishop England preached and presided at the ceremony of the installation. My father had the honor of officiating as deacon at Bishop Fenwick's first pontifical Mass. New England, at the time, possessed only four priests beside the Bishop. We may say only three, for Rev. Mr. Taylor, the late Administrator of the See and Vicar General, had arranged for his return to Europe, and had given in his resignation. He left the country a fev/ weeks later, and died in France. But I must return to 1825. Bishop Fenwick had been in Boston only six mouths when my two eldest sisters Mary and Abigail, arrived there from Georgetown— Mary to remain, Abigail to proceed on to Quebec. The latter tarried some days in Boston and then continued her journey northward ; but was sadly disappointed in not being able to visit her father at his old homestead in My Dearest Abey : Undoubtedly both you and I were disappointed that you did not pass through Claremont on your way to Quebec. But never mind ! Divine Providence is best. I shall see you, I trust, before long. I am hi"-hly satisfied since you are in a religious house. Behave well. Be exact in all your religious duties. Xever do anything but according to your rule. If, at any time things should look discouraging, be patient a wdiile ; be resigned ; be cheerful. All will come right again. I should like to see you in a Nun's dress. How altered ! and yet, my Abey. To speak to ycu through a grate ! I must see you in this manner ; the sight would be so gratifying ! - This letter must be short, but I will make up the deficiency in my next. Your grandfather's health seems to be very poor again. You must pray for him. I have lately received a letter from the dear Samuel, in which he mentions that he continues highly contented with his situation and is endeavorino- to make good progess in his studies. AVrite to me as the permission of the Rev. Mother Superior admitsI shall write to you as occasion renders it expedient, and shall see you as soon as arrangenunts will allov/. Finally, my dear child, be a good girl ; be good, religious and leave all things to Almighty God. VIRGIL H. BARBER, S. J. " Fourteen months after this, Susan and myself left Georgetown for the north. My health not being very good in the autumn of 1880, Mother St. George sent me to Cornish, N. H., to spend some months in the family of Capt. Bela Chase, brother of Mother M. Ursula Chase. The family was a saintly one ; they said morning and nidit prayers ; also the rosary aloud, every day ; adding to the latter a sixth decade, "For Father Barber." On Sundays they recited the whole catechism through, and sang the Kyrie, Gloria, Credo and Sanctus, of 'the High Mass ; Capt. Chase and his wife presiding, and his eldest son accompanying on the flageolet. Their family (principally) formed the choir, and they chanted the Mass, not only through devotion, but in order to retain what they had learned, and to teach their children the same ; for there was then no priest at Claremont ; but one from Burlington visited the station every three months, lodging at Capt. Chase's, where an apartment was always kept in reserve for him. I had been here a few weeks only, when my father's arrival was announced. He h;id come on some business matter, and staid two nights and a dtiy — the only two nights I had slept under the same roof with him from infancy. Wishing to profit by the opportunity of going to confession I several times withdrew to prepare ; l)ut could not stay away from my father. " I put mj'self on my knees to begin my preparation. At length I v/as obliged to give up the idea of confession ; and my father left. After his departure, as I was expressing my regret for having missed the opportunity, Mrs. Chase told me to write to him, for he was stajiug for a few days v.-ith his brother at Claremont (six miles distant) and Avould return if I solicited it. I wrote, and meantime made my preparation, iSText day I sat at the front window^ and w\atched for the mail coach — not a steam car, but drawn by four horses. As I saAv them turning toward the front gate, my heart beat with joy — my father got out, and in a few hours afterwards I had the happiness of making my confession — the th'st I had ever made to him. Capt. Chase and all the family (except the oldest son) went also. After they were all through, I went back to the parlor, and my father, who seemed more delighted than I was myself, took me up under the arms and jumped me several times half way to the ceiling exchiiming : ''Islj baby ! My baby ! ' I was fifteen, but very slight. My father, on the contrary, was remarkably tall and stout, portly and handsome. He always called me his baby, because I was the youngest. After remjiining several years in the north, my father was recalled to the Maryland Province, and stationed, at different times, in Georgetown, Frederick, Caughnawaga, or some other of the Jesuit houses there. He was at St. John's College, Frederick City, when I arrived there in 1833 in company with Mother Agnes and the Foundation Colony, on our way to " Far West. " Stopping at the depot, I heard my father's voice, and looked about in all directions to discover vrhere he was. Still I heard it but could not see him ; but was sure he was near ; for his was a voice of such peculiar depth and beauty as could not be mistaken by one at all accpiainted with his tone. At length I perceived him assisting the Sisters fi'om the front compartment of the (old-fashioned) car. My turn came, and he lifted me outr.s if I was a feather,— then accompanied us to the Academy of the Sisters of Charity, nearly opposite the Jesuit Seminary or College. After a fev/ minutes' conversation in the parlor I withdrew with him, and we walked alone in the Seminary garden. I mentioned to him that my mother (before my leaving Georgetown) had bidden me to go to confession to him at Frederick. " But, papa, " I added, " I have been to confession so lately that I have nothing on mv mind to tell." My father made no answer, but went on pointing out to me the beautiful flowers on the borders. But my mothei's injunction was on my mind and I mentioned it a second time. " I then agreed to prepare for the next morning, about six o'clock. That same evening I asked Mother Agnes' permission to go to Holy Communion likewise ; but she said " as the Sisters were not going I had better not. " Of course I obeyed, but have always regretted the privation as — although I assisted at my father's Mass — I never had the happiness of receiving Holy Communion from his hands. Two hours after this the stage coach stood at the door, and I bade my father a last and long farewell. In parting he put into my hand a paper which I did not open until we were far up among the mountains. It Vv as a little poem begining thus : " God calls thee hence, my darling child. ' ' My father after helping in all the Sisters, closed the coach door One more word of adieu, and v»'e were on our way v.'estward. My father stood on the pavement watching the stage coach as it receded with the last of his five children ; and I too looked out at him as long as he remained in sight. I wrote to him nearly every da}^ during our journey, (as he had bidden me) and again when we reached Kaskaskia, ' which was on Friday, May 8d, the feast of the finding of the cross. Three years afterwards my mother came out WTSt. "Of the subsequent years of my father's life, I know nothing except that he was in 1836 removed to Conewago, and finally to Georgetown College, where he died. His disease was paralysis, from which he had suffered about two years. The only account I have of his last moments is from a letter from my brother to sister Abey. Samuel was not with my father, but at the novitiate at Frederick, whence he wrote to th3 other members of the family. But my mother having, in a severe illness in Mobile — where she was supposed to be dying — caused all her letters to be burned, I have no particulars except those contained in these few lines. I have rather sad intelligence to convey. I received a letter dated the 19th from Fr. Thos. Mulledy, President of Georgetown College, stating that our dear father had been threatened, on the 17th, with paralysis ; lie received the last sacraments ; was perfectly in his senses, was well prepared and quite resigned. Since then I heard by one of ours from the college, that he continues pretty muclj in the same state, expecting dail}^ his dissolution. A letter from Rev. Father Vespre, dated 21st, the procurator of the college, informs me that he is lingering under a slowly progressing paralysis. The symptoms have disappeared from the head ; but his left side is strongly affected. Let is unite together my dear Mary and Abey, in earnest prayer, for so beloved a father, to our father who is in heaven, that he would support us all in the trial, give us all resignation, and teach us to look upon heaven as our only true home. If such be our faith, we shall rather envy than regret our father's lot. Adieu, may we all meet in heaven. Susan gone ; father is going ; happy the one that goes next, if only prepared. Let us join in fervent petition to God and to Mary for the inestimable blessing. SAMUEL BARBER, S. J. Novitiate, Frederick, March 31, 1847. Should we then repine if those we love are recalled from their banishment to their heavenly country ? On Saturday evening our dear father received once more the holy sacraments,— confession and communion, and with a holy calm, perfectly resigned the most holy will of God,— without a struggle at about halfpast eight o'clock, rendered up his soul to his Maker. I need not tell you to pray and to procure as many prayers as possible for the repose of his soul. We know not how much he many need them ; and if he does not, they will not be lost. Let us not repine or grieve immoderately for the loss, but say more friendly than ever : " Our Father who art in heaven !" We have two fathers ; one to pray for us, the other to shower graces upon us. Ah ! my beloved Mary and Abey, such is the case as we may well hope. This hope unfolds to us a brighter country where tears and sorrow can never intrude. Adieu, &c., &c. Three Rivers, Jan. 24, 1837, aged twenty-four years, and of religious profession, four ; preceding him to the tomb by two years. I find the following among sister Abey's papers : * My very dear Susan : A letter from the dear Mary tells me your health is very bad. To me there is something unaccountable respecting you. In consequence of a letter from my friend, Mr. Burroughs, informing me of your illhealth, I wrote instantly, under date of Oct. 10th, begging you most pressingly to tell me how you w'ere. To this I received no answer. At length a letter from dear Abey mentioned that you were much better in health and spirits. With this I remained satisfied till yesterday, daily expecting a line from you. Why do you keep me in this anxious suspense ? I well know you would do nothing to give me pain. But there seems to be a fatality that domineers in this affair. Still, in the words of my last letter, " Relieve a father's aching heart by dispatching me, by the next mail a letter, should it necessarily contain but a single line. " If you arcable, tell me all particulars ; exactly how you have been and exactly how you are now. But in this, be not anxious ; I shall be entirely satisfied with what you can do conV3niently to yourself. Meantime, w^hatsoever may be jowy destiny, rest assured of one thing : Your father wall for a long time to come, as he has for several months past, offer the Holy Sacrifice for his dearest Susan alone. Tell me w^hether you received my letter of Oct. 10th. With the same anxious love with which, for so many years I have clasped you to my bosom and carried you in my heart, I still am, How I wish I could sit at your bed side, watch over you day and night, anticipat\n<r all your wants and assuaging your pains of body and weariness of mind ! But Providence resolves otherwise. Let us then maintain our constancy. Let us walk by faith, not by sight. God is good and true. He will not despise the offering we have made Him. Let His grace, therefore, console us with a just cjDnfidence in ITim whether in life or death. You sent a request that I would offer for you the Holy Sacrifice twice a week. What diflidence suggested this ? Why not say every day? This I shall do until 1 hear from you again. I hope, my dear Mary, you will never conceal from me any of your trials and sufferings on the supposition that it will pain me to know that heaven now and then sets to work to scour and polish your jewels. You are aware that these gems are hardly ever lustrous and valuable in their native state ; but must be split down with a chisel and hammer, and scoured with diamond dust (the most cutting of substances) before becoming fit for a crown designed for the spouse of a king. Now, your jewels are, I think, in the hands of a first-rate artist ; and if we let him have his own way, he no doubt will turn out a capital article for you. You express anxiety about my health, but thank God ! it has, for a long time been good ; and at present my strength and activity are the same as at twenty-five. There came in the same mail with your letter, one also from your little sister Josephine. She and your good mother were well. Their community w^re to remove to the new convent on the 2nd of this month. I had, about the last of June, a letter from the very dear Samuel, (Rome) dated his birth day, March 19th. He was well. I have not been to Georgetown for more than a year. For the pretty flowers from the dearest Susan's cold bed I thank you and also that amiable and promising young novice, Miss du Chene, to whom present my thanks and best wishes, &c., &c, Y. H. BARBER. Mary recovered, and though delicate, lived ten years longer, to the age of 35. She survived my father thirteen months, and died on his birthday, May 9, 1848, aged 38. Yours of the 18th ult. was received to-day. What a lucky day this has been to me ! the dear little Josephine's birthday. As I went down to Mass, (which, of course, was for her) a gentleman handed me a package from your good mother ; and before dinner a letter from the dear Mary and another from yourself were put into my hands ! Both letters were mailed at Boston on the 2nd inst. You judge truly when you conclude that your parents are happy in their children. For what parents could be happier in this respect than your dear mother and myself ? I might almost ask what more could even God have done for us ? Why He should have done this— not to mention His other unspeakable acts of goodness— is what confounds me when I think of my nothingness. To see my dear family, my most and only prtcious treasure on earth, possess the grace to despise the world and the vanities of time and live only for eternity, leaves me without a wish this side of the grave. You want to know^ whether I will visit you this season and will not be disappointed when I tell you I hcpe to see Canada not this, but next summer. I am greatly rejoiced to hear that you are striving to correspond to the grace of your vocation. Persevere, my good, dear child, for the conflict lasts only for a season, and fidelity alone is necessary to ensure victory. How good is Almighty God to dispose things thus sweetly in accordance Avith our weakness ! SISTER MARY AUGUSTIN. Wc transcribe without comments, and almost without change, the following: life of Mrs. Jerusha Barber, wife of Rev. Virgil Barber, named in religion, Sistek Mary Augustin. BurHngton, Dec. 8th, 1885. "The following is an account of the conversion of my mother, written at request of Rt. Rev. J. Quinlan, during her last illness, Dec, 1859. My mother was born at New Town, Conn., July 20, 1789 ; my father, I think, at Clareraont, New Hampshire. My grand parents on my mother's side were Protestants, but very pious in their way ; strict members of their church, and as my mother tells me, models of moral and domestic virtue. She says my grandmother Booth was looked upon as a saint by her Protestant neighbors and acquaintances, and of my great-grandmother mentions one trait which seems to show that she was something more than a merely nominal Christian. In her earlier years when her husband was having a new dwelling house built for his family, she went to see it ; and perceiving that the plasterers had commenced some stucco-work on her bed-room wall, requested them to desist and leave it unfinished ; saying she did not wish to sleep and die under an ornamented ceiling when Christ had been born in a stable. And truly enough, she died in that very apartment at an advanced age. My mother was the youngest of four daughters. To my inquiries concerning her early life she answered that she did not commence to be pious until the age of sixteen, the time of her father's death ; from which date she applied herself to comfort and please her mother and to be " religious " ; though, even in ahildhood, at least from the age of ten or twelve, she had been punctual and devout at her prayers, and had performed all her duties in reference to God. She was in the habit of kneeling and offering to God every new article of dress, before putting it on, i^articularly if it excited any scruples on the score of vanity. I asked her if she did not offer her work and actions to God. " No, " said she ; " I did not think them worthy of being offered to Him. I would have almost considered it blasphemy. In offering my new dresses, &c., it was to ask permission to use them ; and a kind of protestation that I designed not to offend Him in s^ doing. " Several serious accidents befell her in her childhood, of which, in a letter dated Mobile, Al. , 1850, she thus speaks : ' ' The devil has always been fighting for my soul and the souls of my family ; and I feel we can escape his * malicious grasp only by strenuous efforts. I have not the least doubt that it Vv\as he that plunged me into a wtII twenty feet of water, (there being no children or other person near enough to push me) when I was but six or seven years of age. Again in Otter Creek, just above the rapids, when I was in my eleventh year. And the same year, when with my dear father, I was standing by the trunk of a tree, four or five feet in diameter, which the men were felling, who made it incline in a diametrically opposite line to which my father and all the men judged it would fall ; I, with the fiectncss of a deer, barely made my escape, so as to be touched only by seme flexible and light branches. And that is not all ; but it is enough and too much for my leisure. Later, when I had famil}^ he assailed the souls of my children ; and he has always pursued some one of you furiously ; but with the grace of God we will all escape his clutches, and eventually triumph gloriously in heaven. I know and feel that he is frequently molesting me ;-but I spurn him and push on with an effort. And so 3^ou must do, my dear Benjamin.When I penned the passage to which, in j'our late letter, you make such strong objections, our Lord placed before my mind's eye, in such vivid colors, the night, with all its circumstances, when the appalling thunder storm tore the bricks from the chimney of your and my room, that it seemed I could say nothing else. Ah ! how I prayed and wept that night ! for I thought I should behold you a corpse before morning. " My mother has often told me that he was so perfectly devoted to her and his children, that he had no happiness out of his family ; in so much that he was of tentmies impatient when his little circle was encroached upon, or his domestic joj's interrupted by the visits of friends ; LIFE OF MRS. JERUSIIA BARBER. 87 and she was frequently oblig-ed to expostuliite with him on the subject. In trouble, sickness, &.Q., no one could comfort, no one advise him but herself. Ilcr usual antidote for all his ills was prayer. ' And he, ' as she says, * more docile than a child, ' would kneel and recite with her, whatever her piety and affection prompted her to address to the Giver of all Consolation, in his behalf. She was obliged to share in all his thoughts, plans and projects. She was in everything, his chief adviser and assister. He would neither read, hear or sec anything without her. In fact his happiness seemed dependent on her presence and participation. Mary, his eldest child, was born in January, 1810 ; Abey (Abigail), in 1811 ; Susan, in 1813 ; Samuel, in 1814 ; and Josephine, the youngest, in 1816. The first thing, I believe, which drew my father's attention to the Catholic religion was the perus d of the life of St. Francis-Xavier. How it happened to fall into his hands I cannot tell, but the book proved a complete facination. Night and day he kept it by him, even under his pillow, read and re-read it himself and to my mother, and even to the Episcopal Bishop and ministers ; and often, too, offended my mother a little by saying : his parallel could not be found in the whole Protestant church. This must have been before the birth of Samuel in March 1814 — for my father had set his heart on giving the name of FrancisXavier to his only son. My mother inquired what name he intended to give him at his christening. " Francis-Xavier, " he replied. " No," said my mother, "no Popish names in our family. " " Then name him yourself. " " No ; I named the daughters ; you ought to name the son." " Well, Francis-Xavier," — and he could not be induced to make any other selection. They were at the font, no name as yet decided on. My mother again appealed to him. He still answered, "FrancisXavier." She objected. " V»^ell, " replied he, " I shall be satisfied with any name you may desire, " and she called him Samuel, after the holy prophet of the old law. This was three years before their abjuration of Protestantism. My parents did not precipitately embrace the Catholic religion. My father, attracted and awed by the sanctity of the Apostle of the Indies, wished to go deeper into the record of Catholic sanctity and doctrine. He found Protestantism too superficial, too recent, too worldly and too inconsistent. There was neither unity nor subordination in the church, neither power nor godliness in its founders and rulers. After much anxiety and research, in which my mother was made to share his every exploration and discovery, he, with her approval, resolved on making a visit to New York city, for the purpose of con- suiting the works of the early fathers to be found in St. Paul's (Episcopal) library there. He staid a week shut up the whole time in the library, toiling indefatigably at his business of life or death, on which the destinies of his family for time and eternity depended. At length, having obtained answers to all his difficulties, at least to the ijrincipal, he procured such books as he could, transcribed the most useful and conclusive passages from others, and returned home to deliver to my mother the trophies of his labors. She could make no reply to the fathers of the first centuries of Christianity ; but wished to hear them rendered in English by others of the ministers, to see if their translations would agree. Accordingly several, and among them Bp. Hobart himself, translated them for her. She had often told me that my father's patience with her v.as exhausted ; that he took the utmost pains to satisfy her every inquiry, going over and over again, the same points with her until perfectly satisfied. But ii was with feelings of dread and consternation my mother saw her own ground giving way under her, and with pain that she discovered that all her ancient and dear associations must by the unreality or fallacy of their foundation, fall to nothing. Night after night my parents used to sit up together, discussing points of dcctrine and reading works of controversy. Indeed my father would never v^illingly read without her, and she has told me oftentimes, when she became so overpowered with sleep as actually to doze, such was the habit of attention she had acquired, as to know what my father had read. In such cases, if she failed to comment on some striking passage he had expected her to notice, he would stop and say : " There, now ! You are not paying any attention ! " Whereupon she would repeat the words he had just read, while she was listening in her sleep. But as it became more evident to ray parents that they must quit the side of errors ; and as they had openly expressed to the Protestant Bishop and ministers their sense of the insecurity in their Communion, the latter made every ef ort to retain them in their old faith. Several discussions were held at our house ; but the more the primitive dcctrine and discipline of the church was searched into the more its identity with that of Rome became apparent. JMy father, at least, was perfectly satisfied ; my mother not sufliciently so as yet. Tlie Bishop and ministers seeing at last that my father was fully determined on a secession from their church, intimated to him that in case of his taking such a step, he would be expected to resign his professorship and presidency over the Episcopal seminary — just erected into a college — by a grant of the Legislature." My father had already considered the necessity of this ; and tliougli his position was sufflcicnlly lucrative and lionora])le according to the wcrld, it proved not, thank God ! an insuperable temptation to him. He would, however, give no positive answer without consulting my mother ; and withdrew to ask her advice. " If, " said she, " I were to become a Catholic, I would go where I could practice my religion. " This decided him. He returned to the seminary and informed the professors that he intended to remove to New York City. I was born just about this time (Aug. Gth, 1816) ; and the first praj^er my mother ever addressed to the Blessed Virgin was on my account. She promised that if she would deign to assist her in her hour of need, she would believe in and pray to her. She experienced the help desired ; and says my birth was miraculous, but did not explain how. This was August 9th, 1816. The day following the professors and trustees of the college came to make a last effort at reclaiming my father. My mother knowing they would debate points of controversy, and anxious to hear all they had to say in defence of either side of the ciuestion, requested the conference might be held in an apartment adjoining her bed room. She had the door left ajar and her bed drawn close up, so that she could hear every word ; and there during the one or two hours the disputation lasted, heard all the arguments of the ministers refuted by my father. " I heard them, " said she, " yield point after point to him. The trustees then offered to go for Bishop Hobart, but I could not permit them, seeing it was useless. " My parents prepared to remove to New York city. In my mother's note book I found the following : Dec. 24, 1816, Josephine baptized by the Rev, Mr. Fenwick at his house. Jay Street, No. 15, New York City. Feb. 9, 1817, Mr. B. and myself made our first communion at 8 o'clock, in St, Peter's Chapel, Barclay Street. Feb, 2ord, Rev. Mr, Fenwick here ; we opened to him our wish to devote ourselves to religion. The date of my parents' abjuration I do not know ; but thinking their first baptism in the Episcopal Church valid, they were not re-baptized till seven months after their first Communion ; that is Sept. 18, 1817. Being settled in New York, my father applied himself at once ^o the business he had come upon, and applied to the Catholic clergy, who seemed to look upon him with some distrust. Rev, B. Fenwick, however, seemed to penetrate the uprightness and earnestness of his purpose and to take in it a friendly interest. My father was accustomed to go to the ('atholic Church to Mass, vespers, &c., and was frequently accompanied by some of the other Episcopal ministers. One in particular, agreed with him in admiring and approving of evervthing he saw and heard ; doctrine as well as ceremonies ; whereupon my father asked, " why, then, he did not become a Catholic ?" I would have no means of maintaining them. " After my father's death, my mother used to relate this to me^ and with tears rolling down her cheeks ; assuring me at the same time that they were tears, not of grief but of joy and thanMulness to God, that by His grace no such consideration had prevented her husband from following the truth. He had had a good salary it is true, but had lived up to his means and laid nothing by. My mother never knew nor never inquired what became of his house and property near Utica, and never mentioned it to her children, so fearful was she that little claim to earth might be an impediment to a higher vocation. My parents opened a small school for their support ; but could have remained in New York only some seven or eight months, having removed to Georgetown the May or June following. In the same spring Father B. Fenwick, who had been recalled to Georgetown to assume the rectorship of the college there, wrote to mv father, asking him what were his views and intentions, with regard tothe future. My father answered that " were it not for his wife and children he would enter the ministry, feeling a decided call thereto. " He had always been in the habit of reading to my mother every line he wrote or received ; and novv', according to custom read, aloud, both Father Fenwick's letter and his answer. The letter was the death blow of her happiness. " From that hour, " said she to me, '' I enjoyed not a moment's peace. The tJioKgJit that God uanted my brother (for so she called Mr. Barber, after their entrance into religion) and that Iicas the obstacle , pursued me day and night. " But she did not, at first, reveal her trouble to him, hoping time w^ould dissipate it. But it proved the reverse. Everything she read, everything she heard, seemed to boar upon the one point, and to fasten upon her heart with a tenacity from which she was unable to free herself. "I felt, said she, " that I must make the sacrifice to God ; and that if I would refuse He would deprive me of my husband and children both in this w^orld and the next. Of this I felt the strongest conviction ; that in case of a refusal one or the other of us would die and our children be left orphans. " At length, unable to endure her agony of mind, she imparted her thoughts to my father who tried to soothe her by saying that God did not require such a thins: of them and that she must not permit it to distress her. He told her " that in penning those lines, he had not meant them in the sense she had taken, but only as expressive of his predilection for the ministry, feeling himself bound to his family by the laws of God and man. " This would quiet her for a while ; but in spite of his assurances her trouble would return, and at times with such violence, that she was obliged to call him from his school room to give her comfort. " Then, " said she, "he would take me in his arms, wipe away my tears, and talk to me until my fears were almost dissipated. Yet whilst he lavished upon me all this tenderness there was deep down in my heart ti whisper that said : ' This is not God. This is not what He demands of you. ' " Neither was my father without similar impressions, although he concealed them from her, deeming it his duty to do so until better asoured of the will of God. But when this became manifest, he encouraged her to prefer eternity to time and to look faricard to their happy reunion in a hetter world. They were not long in taking their decision, for it was impossible for them to remain in such a violent state of feeling for any great length of time. Yet between its first suggestion and final accomplishment some months must necessarily intervene ; and these were to my parents months of agony. " A thousand times," said my mother, "would I willingly have had a dagger plunged into my breast, and have found it a relief ! for not only did my heart ache with the sentiment of grief ; but it ached physically— the very flesh ached, just as your head aches. Put your hand here ; you cannot feel it beat ; it is not in its natural place ; it is sunk in back." And truly enough, I could not feel the slightest pulsation ; but on applying the hand to a spot between the shoulders, found the palpitations strong.* I need not say I was much astonished at it, and wondered at the moral and physical strength with which God must have endued her to sustain an assault of mental sufi'ering and for so long a time. My father, also, at times nearly gave way under the trial, " When he w^as in depression of mind, " said she " he always wanted me to talk to him ; and, as docile as a little child, would, at my bidding, kneel and recite with me the collect for peace ; a. also that to the Choir of Thrones, which, I think, never failed to trancjuilizing him. Yet I did not immediately surrender myself to grace. I resisted as long as I could and as long as I dared ; striving to turn a deaf ear to it, and to persuade myself God did not demand such a course from me. But in vain. I was compelled to yield. " I once asked her how she had been able to accomplish such a sacrifice. " I did not do it, " she answered. " It was not I ; I could not have done it. God did it for me. He took me up and carried me through it. " it was true. a. O God, from whom all holy desires, right counsels and just works jjroceed g-ive to Thy servants that peace which the world cannot give, that b nh our hearts being devoted to obey Thy commandments, and the fear of our enemies being removed, our times by Thy protection, may be peaceful th-ough Jesus Christ. MR. AND MRS. BARBER ENTER RELIGION. In May or June of 1817, my parents left New York for Georgetown. The following is from Mrs. B.'s pocket journal : June 12th. Archbishop Neal(3 met us at the college chapel, and concluded the business relative to my going to the Convent. 13th. Mr. Barber leaves for Rome.* 19th. A letter from Mr. B. 21st. I came to the Convent accompanied by Fathers Grassi, Kohlman, Marshall and Mr. Ironside (a converted minister). 25th... 28th. Father Grassi leaves for Rome. I wrote to Mr. Barber. 29th. . . A letter from Mr. Barber (from the Bay). July 1st. I commenced a novena for my husband, Father Grassi, &c., July 2nd. The Visitation. The community begin a novena for Fr. G. and Mrs. B. On arriving in Georgetown my parents were, by Rev. Father Fenwick, invited to make his mother's house their home. It was a large and pleasant mansion near the college. This devout widow lady was the mother of four sons, three of whom had entered the society. No ; I think George, the youngest, was still with her, and still a student at the college, of which his brother had been, or was at the time, rector. Being thus almost childless, the kind lady received Samuel and myself under her roof and acted a mother's part towards us until he was old enough to go to college and I to the convent. Ever afterwards she seemed to regard us almost as her own, came frequently to the convent to see me and had me to spend my vacation with her, which last were indeed, the happiest moments of my childhood. In after years I asked her what her sentiments were then. " I felt the confidence," said she, "that Almighty God would take care of you all ; not because you were mine; but because you were iwt mine or any human being's, but His. I had left you ; but had given you to Him. " We remained at Mrs. Fenwick's till the 21st of June. This day, the festival of St. * Archbishop Neale, the saintly fmnder of the Visitation Convent, died June 15th, 1817. The day after Archbishop IS'eale's funeral Mrs. Barber entered The good Archblshvop had about five days previous introduced her to the Sisters in the asscmbl}' room Sijing, •' Not one of them must give Mrs. Barber the black bean. " Mother Theresa now showed the i)ostulant the vault in which their lamented fath^-r was enti-mbed ; and as they stood looking at the newly walled up sejiulchre, one of the Sisters, perhaps to cheer the ccnversatlon by a pleasantry, told the postulant she would have to pass the night following in the vault. "Well " replied she, "I will be in good companj'. " The f)Oor convert had gone through too many tiials to be daunted at the prospect of one night's vigil. " Aloysius, the Jesuits conferred on my mother the honor of invilinp^her to dine with them in their refectory ; which privilege as they told her, had never before been granted any female. It was her farewell dinner. In the afternoon Father Grassi and several others accompanied her to the convent and left her in the hands of the venerable Mother Theresa Lalor and Sister Agnes, mistress of novices. Iler age w^as 27 years 11 months. She began her novitiate with great fervour ; and such was her anxiety to cast off her worldly attire that without waiting for the ceremony of a formal investment, she made herself a complete novice costume, and put it on. The community were not a little surprised, on meeting the postulant, to find she had literally taken the veil. But good Mother Theresa and Sister Agues, mother of novices, would not deprive her of her newly acquired happiness, and w^ere heartily amused at her simplicity and earnestness. Mrs, B. having some difficulty in adjusting her suit, and being at a loss for a mirror, supplied the def cienc}" by attaching her black apron behind a smiall four-paned window, which opened on hinges and looked into the garden. Here she made her toilet every morning, unconscious of any breach of conventual rule, and unconscious of being seen by the Sisters who happened to pass. On July 23, the feast of St. Ann, shew^as admitted to the religious habit, taking the name of Sister M. Augustine. The eloquent Father Baxter preached. His text was : " You are become a spectacle to God, to angels and to man. " My mother's utmost wishes as far as regarded this world were now^ realized. Mr. Barber, in his novitiate at Rome ; three of her children at the convent, and her two babies in kind and safe hands ; they as well as herself ; all sheltered from the world. . But new trials awaited her. I fell sick and was at the point of death, and the priests and Catholics testified great anxiety for my recovery, fearing that if I died blame would be thrown on religion for permitting my parents to leave an infant of ten months. The Jesuits offered many Masses for my restoration, and Mrs. Fenwick's daughter-in-law (who had a young baby of her own) nursed me until I got better. I was so small and puny, they carried me about on a pillow. Another trial followed. Apprehensions began to be entertained by some of the religious that she was in a state w±ich required her withdrawal from the convent. Groundless as these apprehensions were, my poor mother was obliged to yield to the necessity ; and three months precisely from the time of her reception of the holy habit, was obliged to take it off and return to the world. Her note book says : " Oct. 24, 1817. I left my monetary with an extreme rer/ret, and arrived in Baltimore the same evening, where I took lodgings with Mrs. Lewis. I remained till about the 14th of April following, i. e., a few days after took seats at the dinner table. They were Capt. Baker and Mr. . with whom my father had crossed the sea. They talked of their voya^^e • and not knowing who my mother was, said there was on board a gentleman, recently an Episcopal minister, but now preparing to enter the Jesuit order, who having left home, wife and children, was so overwhelmed with grief, that they feared that he would die before he reached his journey's end. " I never pitied a man so in all my life, " said Capt. B. My mother was now almost overwhelmed in her turn, but mastered herself sufficiently till dinner was over ; and then hastened to the church, to seek, in the holy advice of her confessor, that consolation of which she was so much in need. Rev. Mr. Moranville received her with paternal kindness ; and thanks to the words of salvation that flowed from the lips of the minister of God, she returned home filled with new courage and comfort, resolved to trust more than ever in the Divine Goodness. She seldom went out except to church, and that very early in the morning ; " and when I did, " said she laughing, " the boys used to run after me in the street, mv old bonnet and brown cloak were such sights. " I asked her if sht had no decent clothes. ' ' I gave away all my best. " said she, " before going to tl\e convent, thinking I would have no use for them there. After taking the veil, the others were disposed of ; and expecting to return to the convent in a few weeks, I did not care to make any new outfit. Indeed, I had enough to think of besides my dress. Besides I lived in total retirement. " My father on receiving intelligence of my mother's position, hastened back to America ; but on his return found her again in the convent. Her novitiate was one of severe trials, as well on his account, as on account of her children. The community was in the utmost poverty and found the maintenance of the latter a heavy burden. I copy from her note book : " Aug. 13th, 1818. I had an interview with Father Cloriviere, in which he made known to me the narrow state of the finance of this house, and suggested that my brother (so she called my father) should become a secular priest. " "The charge was taken with a full expectation of remuneration. I embraced the supposed free bounty as a blessing sent from heaven through the channel of the holy church, considering it to be deliberately conferred upon us by these her chosen children. But the mystery is at length solved. Providence has withdra^vn the veil, and I behold myself and family feeding on the bread of dependence, necessarily continued because ignorantly and involuntarily commenced. Though ^vc may have no just claim of the Institution of which we arc in some sort, members, si ill oiu- children have a claim upon us. Now, what is this claim and how far does it extend ? " To explain my parents state of utter destitution I must mention the following causes : My mother was the youngest of a large and once wealthy family ; but her father having a year or so before his death, gone security for a friend, lost nearly all he had, and left his youngest child unprovided for. The others were, I think, all settled. Not long after this she married my father, who, living up to his means, was not prepared for the change of circumstances which followed . She, on entering the community at Georgetown, had, of course, no suspicious of the extreme poverty under which they were suffering- ; attributing their severe manner of life and voluntary self-denial to the austerity of monastic rule. She has often told me that she did not expect to live more than three or four years, supposing that in this lencth of time the vigils, fasts and hardships, would bring her to her term. Her journal goes on : " Oct. 16, 1818. Brother Heirome (my father) comes to the parlor sick and dejected. All is uncertain and fluctuatiuir. He is preparing to go into the country with his father for his health. His superiors specify no time for him to make his vows, nor do they give any encouragement to suppl}^ the necessary means. " " Oct. 17th. At the request of our kind Mother (Theresa) the community, today, offered their communion for him. Mother, Sister Agnes and the three children (by the goodness of Almighty God, and the tender affection of my superiors' hearts) has commenced a novena with me for the relief of his necessities, if it be agreeable to the holy will of our dear Lord. " " Oct. 22d, 1818, Friday evening. I entered 'Retreat' with the other novices. " " Oct. 27th. Wednesday. I made a confession of my whole life to our spiritual father, Father Cloriviere, at 10 o'clock A. M, Mother Agnes tells me that having been, when aged about two years, taken to the convent to see my mother, I did not know her and refused to go to her. She extended her arms to take me, those present telling me she was my mother. " No, " said I, " she is not, " and persisted in refusing to leave my nurse. When wc were gone, my mother retired to her cell to give vent to her grief. Sister Agnes! who had been present, and was then mistress of novices, suspectinohow the case stood, followed shortly after, and found Sister M. Angus'^ tine weeping bitterly. "What makes you cry ?" supply. On February 23d, 1820, nearly three years after this separation, my parents met in the Georgetown Convent Chapel to make their vows. My mother first went through the formula of profession in the Visitation ; and then my father pronounced his vows according to the rite of the Jesuit Order. Their five children were present ; Maiy, the oldest, being ten, and I, the youngest, only two and a half years. Mother Cathrine was at this time Superior ; but dying the December following, Mother M de Sales was elected, who, in December of 1821 was succeeded by Mother Agnes Brent My mother had hitherto been employed in the school ; but Mother Agnes appointed her directress, and at the same time ordered her to train some of the younger Sisters for the duties of the academy, A better system was organized ; and under the combined zeal, and prudence of Mother Agnes and Father Cloriviere — the latter of whom held classes of French and drawing, the little academy began to prosper.* I know nothing more of this part of Sister M. Aagusline's life, except that she continued to suffer inexpressibly on account of her children ; feeling them to be a burden on the community in its state of poverty, and knowing the opposition of some of the Sisters to their remaining, v»^e were necessarily poorly clad ; and she had told me that many a time she has sat up nearly half the night patching the children's clothes (for she at this time had charge of the school) and knitting stockings for them ; and that on cold winter mornings when the girls were going to 3Iass, she used frequently to take down from the window an old baize curtain to throw about Abey's or Susan's shoulders, they having no shawl or cloak. I just now asked mother (for I am now writing in her roomf) following notice of Sister Barber : * '• Among the most remarkable Sister* cf Georgetown — Visitation Convent— stands Mary Austin Barber. When Mrs Barber entered Georgetown Convent, the school was sadly in nerd of such a member. She had received a superior education and her methods of instruction were so well adapted to the purpose that the children under her care progressed ra[)idly, and as a result the school began to increase, and the prospect-; of the convent to brighten. She was a woman of superhuman energy. She taught the children in the school during the day, and during recreation instructed the Sisters, that they might become better teachers. She put her whole soul in what she was doing, often forirot herself, but never prayer. In her case prayer might truly have been called the life of the soul. She did nothing without prayer, and she strictly fulfilled the precept of our SaAiour to pray always. When made directress she would often say to those near her : • Go, pray that I maj' attend to this business properly. ' The school continued to prosper imder Sisier Marj' Austin's care, and in 1S;28 it bore the reputation of being one of the best in the land." AVhen you were in w\nnt of shoes we used to go to the pile where the girls' old ones were thrown away and select the best from among them for you. Sometimes they were so large that you could hardly walk in them. You had not always sheets on your beds ; and in winter, when your bed clothes were insufHcient, I used to cover you with the other girls cloaks and shawls. These and other things w^re owing to the poverty of the house, and not to any unkindness on the part of (he charitable Sisters, nevertheless they kept my mind in a constant state of suffering, good Father Cloriviere, old Mother Theresa and Sister Agnes were, however, very kind and did for you all in their power. ' ' I would have put myself " added she, "under the feet of any one who would do anything for my children. " Dear Sister Augustine : Yours dated Feb. ITth, was received to-day. You complain of my silence. I wrote to you some time in November. About middle of December I left here for Canada, where I remained most of tlie winter. From Montreal I wrote to Mary. It is a week since I returned to this place. So much respecting my silence. With regard to your letters I have to say that all you mention have come to hand, and if mine have not reached you there is fault scmewhere ; possibly in the postoffice as is probably the case. Why do you indulge in those anxieties * Such was the poverty of the commuriit}- at this- time, that being in want of the very necessaries of life, they had determined on dispersion, when the providential ariival of the La Sailas caused a change in the plans, * On the second day of January of this same year. Rct. Virgil Earber visited the Ursuline of Quebec, and informed them that he was then engaged in building a small church for his convert? fit Claj-emopt, New Hampshire. (Annals of the Ursuline of Quebec.) which your repeated representations of the embarrassment of your community indicate ? Give yourself, my dear sister, no uneasiness. Almighty God will always provide for them that love Him. And it is a very small part of my concern whether he will take care of us, in compcr'sou of my solicitude that we by love and obedience, render ourselves worthy of his fatherly protection. Teach the children to pronounce daily, this aspiration : ' My God and my All ! ' Thus far I have written without having looked at your former letter, which I have net time to read before closing this ; but I will answer them all particularly in a few days. My love to dear 3Iary and the rest of the children. I will write a letter to her and Abey as well as to Susan and Josephine, and another to Samuel in a vreek or ten days. My kindest respects to the Rev. Father Cloriviere, to the good Rev. Mother, and all the devout Sisters. Tell them I beg the continuance of their prayers. Pray for me yourself. Your affectionate brother in Christ, In the autumn of 1825, my father came south to be present at the consecration of Father B. Fenwick, Bishop-elect of Boston, — the same who had received him into the church. This diocese then comprehended all the Xew England States, and my father was one cf the three priests who formed the entire ecclesiastical force of the Xortheast. There was only one priest in the city cf Boston, one in Maine, and one (my father) in New Hampshire. Bishop England and himself accompanied the newly consecrated prelate to his Episcopal city, which they reached Dec. 3d. The following day (Sunday,) the ceremony of the installation took place, and my father had the pleasure of assisting Bishop Fenwick as deacon in Lis first pontifical Mass. But I must go back a little. While Bishop Fenwick and my father were in Georgetown, they made arrangements for Mary's reception at the Ursuline Convent, Bcston and Abey's at Quebec, Canada. My father then met his wife and children all together for the last time. It was a tearful and sorrowful meeting and parting, Next morning, Nov. loth, my father joined the two Bishops for the North. In April, according to agreement, Mary and Abey left for their final destination. They travelled as far as Baltimore with a widow lady, ]\Irs. Jason Jenkins, at whose house they remained some days. (This Mrs. Jenkins afterwards entered the Yisitaticn Convent in Mobile, became Superior of the house, then infirmarian, and nursed my mother in her last illness. She was a person of great sanctity). Arriving in Boston Mary received the veil on August loth, and Abey in Quebec on September 11th, 1826, and were professed on the same day in 1828 taking in religion the names of St. Benedict and St Francis-Xavier. On the feast of St. Augustin, 1827, Susan and myself left Georgcto-wn for the north ; so that none remained with mother except Samuel at the college ; who also, not long after, entered the Jesuit Novitiate at White Marsh, where he made his vows, Aug 10, 1832, and immediately departed for Rome. On Sept. 22d, the feast of the Seven Dolors, 1839, he was ordained priest, and on the 24th (our L. cf Mercy) celebrated his first Mass. But to resume my narrative, Mary— in religion Sister M. Benedict— took the religious habit in the Ursuline Convent at Boston ; and Abey— Sister Francis-Xavier— in Ursuline Convent of Quebec. Two years after Susan and Josephine left Georgetown ; the one for Three Rivers and the other for the Ursuline Convent in Boston where Mary, the eldest, was shortly afterwards professed. Samuel made his vows in the Jesuit Novitiate at White Marsh, Aug. 15, 1832, and during the same summer left for Rome, in company with Father McSherry and his fellow novice and namesake, Father Samuel Mulledy. On September 22d, the feast of the Seven Dolors, he was ordained priest ; and on the 24th, Our Lady of Mercy, celebrated his first Mass, 1839. I accompanied the foundation to Kaskaskia in 1833. My mother had now none of her children with her ; but my father was generally at some of the houses in the Maryland province, and she had frequent opportunities of seeing him. She has several times told me that she attributed the origin of the religious vocation of her whole family to the following causes : " Previous to my marriage," said she, " being extremely anxious to obtain the consent of my family to the union, and apprehending opposition from several of them, I had recourse to God, and repeatedly promised Him that if lie would gi-ant your father to me, I would give him back again, and all my children likewise, if I had any. Twenty times a day did I throw myself on my knees and reiterate this promise, not comprehending fully the purport of wdiat I said nor imagining the sense in which God heard it ; but I have always believed that this promise was the foundation of the religious vocation of our family. " On the 17th of April, 1833, the colony departed from Goorgetow^n tor Kaskaskia. It consisted of Mother Agnes Brent ; Sr. Genevieve King; Sr. Helen Flanigan ; Sr. Gonzaga Jones ; Sr. Isabella King ; Sr. Ambrose Cooper ; Sr. Rose Murray, and an out-sister who left. There were no steam cars in those days ; but horse cars were running between Baltimore and Frederick. On arriving at the depot in the latter city, my father met us ; and here I saw him and went to confession to him for the last time. We arrived at Kaskaskia on Mav 3d, " the finding of the holy cress, " and I entered the novitiate that summer. The house was much in -wtint of members. It had been established three years, and as j'ct only one postulant had entered and she v/as an iuilrra member from the Sisters cf Charity. What rendered the matter worse was that there seemed scarcely a hope of our obtaining members in this " out-of-the-way pl:;ce " either from the town itself, vrhich was unpromising in a religious point of vievr, or from a distance, Kaskaskia being difUcult of access, and but little known, except to the Creole population born there. Rev. Ph. Borgna, Bishop Rosatti's Yicar General, went on to Georgetown to ask for assistance ; and as directed, named Sister M. Augustine in particular. 31. Juliana consented, and Father Borgna, afraid of losing his prize, hastened off with her to Baltimore, left her there with the Sisters of Charity, and then returned to Georgetown to try to get more ; but in this was unsuccessful. Meantime my father, who was stationed at Frederick, having received her letter informing him of all that had taken place, Vv^cnt on immediately. Not finding my mother at Georgetown, he started for Baltimore and on reaching the city made his way to the asylum, where his cousin. Sister Genevieve Tyler, was Sister Servant. My mother knew his ring at the door, and requested Sister G. to inform him that she could not see him out of her convent without an express permission from the xirclibishop. He withdrev,' and did not return that night ; but having obtained the permission returned next morning and had a long interview with her. This last sevcrence from her seemed to open a new wound in his soul, and to renew the pangs of former years. Though separated, he had had the comfort of seeing her at the grate, and feeling himself sustained spiritually and mentally by the words of holy and cheerful encouragement she spoke, as well as by her promise of pra}'crs in his behalf. This had been to him a stay, even in the world ; but novr it must be relinquished too. It was a hard trial to him, during the last ten years cf his life ; and to her likewise. Once, while at Georgetown, she got permission from the Archbishop and Mother N. to make a general confession of her whole life to him, thinking that she could speak to him more freely and importune him with more questions and explanations than she could venture to trouble any other priest v/ith. She accordingly prepared and wrote her confession and on his next visit invited him into the church under some pretext or other, without mentioning her real object. When they reached the Sacristy, she informed him of the permission she had obtained and the preparation she had made. lie replied that he would listen to all she had to say, and answer all her questions ; but not by way of confession ; and I believe he satisfied her fully. She remained, I think, about a week in Baltimore, during v.hich time w\\ father visited her frequently until Father Borgna's return from Georgetown, when they the far west. Fatlier Eorgna next took her to Emmittsljurgh, \vhere slie remained several days, at St. Joseph's, having the happiness of making acquaintance with the saintly Mother Kose and other members of that edifying house. She did not reach Kaskaskia until Sept. 24, 1836. " a. In the summer of 1848 our house at Mobile being greatly in need of members applied to ours for assistance. My mother was one of the four sent thither. In the winter of 1855-6 a severe attack of illness brought her to death's door. Her recovery was considered next to miraculous. But before this occurred letters came from Mobile requesting that I might be sent thither to supply her place. In those days no railway route was in existence; and the river being closed I could not travel until after Easter. On arriving I found my mother up and on duty. She had organized a class of young Sisters to whom, as formerly at Georgetown and Kaskaskia, she devoted daily a portion of her time— chiefly the recreation hour after supper. In a few years they became accomplished teachers, and were able to dismiss the seculars, for a time employed with so much expense and inconvenience. On the feast of St. Francis- Xavier, December 3, 1857, Sister M. Augustine was taken with her death sickness, a violent cold, which, falling on her lungs terminated into consumption. For two years she was confined to the infirmary, yet was seldom obliged to keep her bed. She usually sat in her arm chair all day long reading and praying. So accustomed was she to rise at 4.30 or 5 that not even in this her last sickness, could she divest herself of the habit ; but was generally seen at her place in the choir, at the reading of the points for meditation and during Mass ; the choir being on a level with the infirmary so that the sick could easily resort thither. During the last six months, however, she was confined to her bed and during the last three quite feeble and helpless. The infirmarian (Sr. Alphonsa) attended her with a charity truly maternal. All the Sisters did the same ; and my mother often spoke of it to me as a motive of gratitude to heaven and to them. " I have been sick," would she say, "these five, ten, eighteen,— twenty months, and our good Sisters wait upon me as if I were a princess. " Sister M. Augustine beiug for the last live months, so feeble as to be unable to rise alone or to help herself, the infirmarian gave her a litlle bell by which to call herself or Sister Aloysia who slept in an adjoining infirmary. To the best of my recollection, the second ring was never needed ; and although the bell was tingled several times every night never was a sign of annoyance betrayed ; but, on the contrary, if my mother attempted to apologize, good Sister Aloysia failed not to silence her by an affectionate railery or repartee ; as if her patient were conferring instead of receiving a favor. Once or twice I expressed to Mother Gonzaga O'Driscoll my regret at the txouble my mother's long, protracted illness gave. " No trouble whatever, " said she. " It is a great honor to us to have her die in our community. " The saintly infirmarian instead of tiring of her charge from length of time, appeared to become more tender and attached ; watching her as a mother would watch her child. I frequently heard her speak to the Sisters in praise of her patient, relating to them what she had said and done — and with evident pride and pleasure. Once when they had gone at the " quarter bell " to see her, and finding her too ill to speak, had retired to a corner of the infirmary to speak in whispers, I overheard Sister Aloysia extolling her to them ; telling them of her patience, etc. " Sister P. have never seen patience like that of Sister Augustine." Words of greater comfort never reached my ears. Wishing afterwards to know what value I might attach to them, I asked Sister A. (without telling her why) how long she had been infirmarian I Her answer was : "All my life. I took care of the dck in the world : and in religion have nearly always had charge of them ; in Georgetown as v/ell as here in Mobile. " This lady w^as a widow, and in more than one particular, imitated the holy foundress of the Visitation. In the early part of December, 1859, Bishop Quinlan arrived in Mobile. Archbishop Purcell and several other Bishops accompcnied him, to assist at his installation. It was dusk when they arrived ; but notwithstanding the lateness of the hour, they drove out to the convent that same night, and our children welcomed them with some verses and music. While these were being prepared the Bishops went to the infirmary to see my mother, and Archbishop Purcell (as the room was crowded) sat on the foot of her bed and conversed with her some time. She afterwards told me that his words had imparted to her great spiritual comfort and assistance. On meeting our good Bishop Quinlan, I b irst into tears. " Most fully did he redeem his promise. Whenever he came to the parlor he went in to see her ; and so kind was he that his very presence conveyed comfort. It was owing to his kindness that she received the holy Viaticum on Christmas, and again on New Year's day, the day of her deatli. The Bishop happening to meet the confessor in the inlirmary— it was Christmas Eve, I think, said to him : " Father D., you will give her Holy Communion to-morrow. " " My Lord, it is only three days since I administered to her by way of Viaticum. " It was then customary to give it only once in eiglit days. But tlie Bishop replied : " Nevertheless, let her receive the holy Viaticum again to-morrow. " Eight days afterwards it was brought to her again, and for the last time. She had, however, desired and expected to die on Christmr.s. The infirmarian seemed to anticipate the same ; but Mother Gonzaga said : " No, no ! she must not die on Chrstmas Day. It would be uncharitable ! " Then the saintly old infirmarian bent over her and said : "Nevermind ! Sister M. Augustine, may be our Lord will take you on His own circumcision. It would be a beautiful feast to die on, the day when He first shed His blood for us and took the nam^e of Jesus. I will ask Him to take you then. " Her petition was granted. On the morning of Jan. 1st Father D. (whose house was only a few rods distant) called several times inquiring how she was. Some thought tlie patient would live till morning, but he charged them to send for him in case of a change. Sister Aloysia sat up with her. She made the infirmarian and myself retire. I lay down in my clothes ; but was soon called up again. My mother lay speechless, but conscious, and Sister Aloysia repealed aspirations aloud by her. Before we arrived she had attempted to say something to Sister Aloysia, but her speech was unintelligible. '' I icant," was all Sister A. could understand. The latter began to guess ; and mentioned everything and every body she imagined her patient could want. " Do you want Father D. ? " " No. " "Do you want Sister Alphonsa ? Mother Gonzaga, Josey ? " " No. " The dying Sister again repeated : " I want, " but could get no further. Sister A. made new efforts to find out what she wanted ; but seeing them useless and a cause of fatigue to the sufferer, she said to her : " Sister M. Augustin'e, you have made many sacrifices to God ; make this one ; I cannot understand you. " At this my mother desisted from any further attempt ; but seemed to acquiesce to the suggestion of her good nurse. Farther De Gaultiers now entered in great haste. At first he thought she was dead, and went over to the bed to ascertain. Another heave of the chest told him of the contrary. " It is not too late," said he, " she is living" ; and snatching up the Ritual, which Sister Aloysia had taken the precaution to leave open on the table, read the absoultion in arii^ulo mortis. One minute afterwards she was no more. She died at 11 o'clock forty minutes P. M. on Jan. 1, 18C0. R. I. P. on Jan. 3d. Bishop Quinlan, Father Pellicier (now Bishop of San Antonio, Texas) and Father De Gaultiers sang a Mass of Requiem, and Sister M. Augustine was buried in the Convent cemetery." I must here copy the letter I received frora Father Koh'raan. I do it the more \\illingly as it comes from a Saiut. Besides, it shows how much we are indebted to Almighty God for all he has done for us, and how ungrateful we shall be if we do not exert ourselves to make the little return of which our poor nature is capable. Long, too long, have I postponed answering the many and truly interesting favcrs with which you have been pleased to honor me. I mean that of January 9th and May 24, 1835, in which you had the kindness to convey to me a detailed notice of the admirable ways through which the Lord conducted you, together with your dear children, to the happy state which at this moment you and they enjoy ; and then of the interesting entertainnu'Ut which the thrice hajipy Sister Stanislaus had with her worthy father, and finally, of the second miraculous cure of Sister Beatrice. This last I begged our dear Samuel to translate (into Italian) for ihe perusal of the Sisters of the Yisitaticn in this city, who were very much edified at its contents, and hence a desire to correspond with your Convent. How much matter for deep and joyful contemplation is contained in these your kind communications. The history of your own worthy family, from its beginning till now, seems indeed to be a picus romance, and nothing can give me greater delight than to rehearse it everywhere. The same may be said of his strong-minded companion, Samuel 3Iulledy. Your worthy mother and sisters shall not be forgotten by me when at the altar. The heroism with which you gave yourself, together with your v.hole family, up to Almighty God, has been, I am sure, the source of these extraordinary blessings which the Lord has bestowed on it, and will, no doubt, powerfully move Almighty God to fulfil your wishes in the spesdy conversion of your dear mother and sister. A mother and sister of so many tears will not be lost. How much I rejoice when I rellect LETTERS OF SISTER MARY ST. A UG VSTINE. 105 that your establishment, which I saw like a mustard seed at the time cf its venerable founder, should have, in .so short a time, grown into a lofty tre-% whieh is likely, ere long, to extend to ail the States of America/ Continue, I beg you, to favor me from time to time with ycur edifying writings. Remember mc most respectfully to your Rev. Superior, to your whole much revered community, and especially to the venerable Sister Theresa, who may be considered the first stone laid in the foundation of your now most flourishing Institution : and give me a share in your holy communications with Almighty God, As to you and your whole blessed family, you have become too dear to me that I should ever be able to forget you and them. Accept these sentiments of the most respectful attachment which shall only die with mo, cr rather, survive my temporal pilgrimage to last for all eternity. Yerv R. S., Yours, etc., in Christ, ANTHONY KOHLMAN, S. J. P. S. Your dear Samuel sends you his most tender love ; and Fr. K reoucsts vou to remember him most respectfully to Rev. Father Barber and his venerable father if still alive. I have given you the entire letter of the saintly Father, hoping it will inspire you (as it certainly ought me) to penetrate into the depth of your nothingness on seeing how far we fall short of what is so justly expected of us. Gcd has, indeed, done a great deal for all and each of our family ; may we not expect he will say : " What is there I could have done for my vineyard that I have not done ?" But his mercy is net exhausted ; he still calls—even this letter is a new grace, and both you and I will commence now% in the beginning of this new year, to love him more and serve him better than we have ever done. Our B. Lady has, it seems, already given you the start by lending you her special aid. I won't be jealous of this preference. Go on ; and as I am getting old and clumsy I shall be glad to be drawn on by your favor. Your very, very acceptable letter came too late for me to learn that you wished me to join in a novena pre\ious to the anniversary of your profession : yet my heart, my good angel, or something had inspired me to do it. My poor heart had been a great while longing to hear that my dear Josephine was pressing forward in the way of perfection with the same ardor as on the joyful day of her profession ; and this news, so necessary to my happiness, net reaching me, I anticipated your desire. The day this is put in the office I intend to begin a thirty-days prayer for you, and I hope you will get it soon enough to join in the last ten or fifteen days. I do i.ot mean to say the old one in the ''Pkiis Guide," but a prayer which came with the miraculous medal ; a mem- orare, a sub tuum, and the aspiration on the medal. You have £0 many prayers said for you by your father, brother, sisters, and others, that you will soon become perfect if you let none of the graces pass by you to others. But this I trust I need not apprehend, since the medal with the no vena of j^our kind and pious mother and sisters proved so efhcacious. As long as we have life, nature will require a constant curb, and this with you, as well as the rest of us, will ccst many severe conflicts, unintermittiug watchfulness and great self command. This will be painful to endure, but the consolations which result are more than sufficient to indemnifj^ us in this life ; and what may v;e not hope from the bounty of our dear Jesus in the next ? When the duties of the day have been attended with several trying circumstances, and we, regardless of the suggestions of the inferior part of the soul, have borne them with an amiable and sweet silence, happy to increase our Saviour's love at so cheap a rate, with what confidence may we not approach him in our evening prayers ! If we seem to say but little, may we not, kneel in his presence and reflect that He sent us these little trials merely to prove our fidelity and to afford us an opportunity of obtaining that delightful union of true love which can be operated only by the cross, or rather, on it. And when we fail, my dear child, let us still go to Him. Let us then say: "My good Jesus! have pity on your poor child, since you see how weak she is." FOr my part, when I seem to commit nothing but faults, and I have nothing to offer him of my own — not even a satisfactory correspondence to one grace — I then offer Him his own merits, his own love, and the love and merits of his Blessed Mother and all the Saints. This is one of my particular devotions, especially during the divine office. Some of your community have St. F. deSalies' admirable treatise on the Love of God. Somewhere toward the end of the third book (if I remember rightly) jow. will find the praises which the saints, — our Blessed Lady in particular, the holy Humanity of our Saviour— and finally, those which God render to himself from all eternity, beautifully explained. AVhat was said of the Gloria Patri made a particular impression on my mind, and I am sure, if you will read it, you will think as I do — that in no book can be more nourishment for prayer and devotion. If mother approves, read it attentively and write me your sentiments in detail. You have no idea how much the pious reflections of my children excite my devotion. Sometimes I find myself getting lukewarm. A letter comes from some one of the five ; it breathes fervor and devotion, or perhaps it tells me that the poor soul is oppressed by spiritual languor, that it would gladly overcome. In either case my fervor revives. I am perhaps ashamed to see my children taking heaven by violence whilst I lie groveling in the earth. Or if the soul be in a state too much resembling my owr, I immediately go to lay it at the feet of our dear Jesus. I put it close to the foot of the cross that it may be qnitebdthedin, Ills precious blood; I immerse it in this same blood, in holy Conununion ; I offer it on the Paten with (he Sacred Host, and in short I try to incorporate it in such a manner with the adorable Son of God that the Eternal Father cannot reject it. Do the same for me, my dear child, and for us all. If we do not tell you of all our little weaknesses we have plenty of them to struggle against. Sometimes bear a cross and offer it for your aged parents, (for we are now getting quite old,) at another time for your sist(r Susan who is always sick ; at another, for your brother who is obliged to pursue his studies and keep up his fervor amid so many distractions and laboriovs occupations ; then for your elder sister, who, I dare say, find crosses even in those cold regions. You see it is very well I copied the letters on the first part of the sheet, for when I get to chatting with you I nev( r know when to stop so long as paper remains. But I must really read over your letter and see what points remain to be answered. I coincide with you entirely in regard to the offering you made of yourself to our Blessed Lady, and firmly believe that if you persevere in claiming and suing for her very special protection, she will not refuse it. Tell her you were offered to her by contract, even before your birth ; and it was in consequence of this contract that your natural mother first paid her devotions to her. Kiss the medal very often and repeat the prayer engraved upon it. Apply to her in all your little difficulties as well as in your trials; for I have witnessed her miracidouspoicer more frequently in regard to things of apparently small moment. Don't forget St. Joseph, however ; he is next to our Blessed Lady, and will not fail to aid you whenever you ask him. I am very glad you have a devotion to St. Augustin. Continue, and you will find him a true and eflicacious friend. Sometimes also invoke St, Monica. I feel more indebted to good Mr. Borgna than I can express, and you, my dear child, what do you not owe him for so much kindness ! so many masses ! Present him my sincere thanks for all he has done for my poor child, v,'ith my very humble and cordial respects. I made, I think, a slight acknowledgment of your kind letters to myself, «S:c When Bp. Fenwick was here I kissed his ring and got his blessing for you. He had gone long before your letter arrived or I might have done it again and satisfy your devotion. As to getting your Father to write, I fear it will be rather a difficult task, as he seldom writes to any one. With regard to my prevailing on him to ^^sit you, I must refer you to our Blessed Lady and St. Joseph. They alone could do that. of all your concerns. Dear old Sister Theresa is here and bids me tell you to " make hay while the sun shints," for \^hen you got old as she is, you can do bat little. She also tells me to say fcr her, that she hopes you are humble, docile and obedient, and all that is good. You may be sure your mother will net oppose this. No ; and that you may be all this, and every thing that will render you dear to our good Saviour, is my constant prayer. In my annual retreat, there was a passage in one of the meditations which struck me so forcibly that I got Sister S. to translate it for me, and I will here transcribe it for you : Is it not excellent ? When you write tell me how you like it. But it is time to bid you farewell, and I must s.iy a few words to your worthy Superior. SR. M. AUGUSTINE. Your dear letter of January 4th is by me, and no doubt you have often thought the answer was long coming, for, as I have much more writing to do this year than I had last, it is difficult to find much leisure. Besides I had your letter to transcribe twice, that I might send a copy to your dear brother and sister (Josephine) each of which was accompanied with a pretty lengthy letter of my own, which, I flatter myself, will secure some prayers to my dear Abey. JMaiy iu one of her last letters said that as soon as she should be in heaven she -^oiild try to get all our little family snugly fixed there :— and it seems she is commencing with j'ou. Be ccuragccus, and repeat freciuently — in your heart at least, — that beautiful aspiration ^vhich so much consoled your dear sister in her pains, and Avliich you are endeavoring to repeat on every occasion. Yes, let the holy ^vill of God be done in all things ! but may we never offend Ilim ! Say this lovingly : say it conlidently ; that is, with the conviction that being just, wise and xaiernal, it will never suffer anything to befall you but for your good. If we truly confide in our dear and merciful Father who is in heaven, He will not only call us cut of this life at the time He sees us best prepared, but he will so nicely proportion His grace to all cur pains and crosses as to afford us wherewith to satisfy His divine justice, and obtain a speedy union with Him. For instance, if through the m.ercy of our poor human nature, you were to forget yourself so far as to speak impatiently to one of your dear sisters, your spouse, seeing that all your trust, confidence and expectations were in Him, might inspire you to ask pardon promptly and thus repair the fault. And if He discovered regret in your heart for having caused Him a little displeasure, may you not suppose that He would grant you the grace to say : "Eternal Father! I offer Thee the most precious blood of Jesus Christ, in expiation of my sins and for the wants of thy holy church, " or something similar by which you would become dearer to Him than before your fall ? Passing from small to great things, extend this confidence even to the moment of death, and you will totally disarm that king of terrors. You remember the quotation I made from St. Liguori's " True Spouse " for your beloved sister Mary. Yet as I wish you and all who are dear to me to reduce it to practice when the critical moment of death may arrive, I will have it copied and enclose it in my letter. You have continual occasion to practice this holy resignation in your pains ; and I beg you, my dear child, to bear in mind that each act pronounced ; each little turn of the heart, showing to jowy dear spouse that you wish and resolve to embrace all his wills, will increase His glory and your happiness (as says a little book of devotions to the S. Heart) not for a short period, such as you will employ in pronouncing it, — but through all eternity. How good and tenderly paternal is our dear Lord to furnish us with such easy means of canceling our debts and of amassing treasure of glory and happiness ! He is all love, and He wishes to be loved. Love Him, then my dear child. Love Him for yourself. Love Him for me, love Him for us all ! and as you have long been " Mary's little goat, " ask her if it is not time to change you into one of her little lambs. Beg her confidently and lovingly to {\o\\so:m, tl; at you may give more glory to that sweet and teautifiil SON, of whom the Eternal is father and she is mother. Tell her to think of this incomparable honor of being associated with the eternal father to produce a son for the redemption of us poor sinners. Then coax her, beg her, importune her. Offer her your pains ; tell her that you will bear them for her sake, if she and dear St. Joseph will only come and unite with you in aspirations to her adorable son whom j'ou so much desire to please. If you are not exceedingly low, this will not fatigue you ; it will rather divert your thoughts from your pains and from yourself to think of those beautiful, those enchanting beings with whom you are soon to dwell. Beg some precious pearls from her, from St. Joseph, some from your dear angel and each of your patrons that you may appear decked agreeably to the taste of your illustrious spouse. I am so pleased you wTre not afraid to go and meet Him, even when you were so ill as to make it appear probable He was about to call you. That shows confidence, and it delights me. Love your spouse. Confide in your spouse ! but neither dread nor fear Him (save the fear of displeasing Him). I would wish to repeat it a thousand and a thousand times. Pin the little paper I enclose, to your curtains, and read it often. The enemy will perhaps whisper : "But you have reason to lose or diminish your confidence, for you have been a great sinner. " That you have been a great sinner I can readily believe ; and so have I. I have the sins of upwards of sixty years weighing upon me ; and with them all. aggravated as they are, by abuse of grace, I will still confi.de in our dear and merciful Lord ; for I know His mercies and His merits are sufficient, not only to outweigh all my sins, but tliose of thousands of worlds. Apply this to yourself. Cast yourself into the arms of His Providence, and repose there. Let him carry you where he pleases. Let Him do with you what He pleases ; all will be well. You have nothing to do but to confide in Him, and accept amiably and lovingly all that He may send. Lie and kiss the heart of your dear spouse, — (your crucifix) — with the intention of doing all that I have suggested, and He will accept it and even supply what you have not strength to offer, if He can only see you have the will to do it. I thank you much for the prayers and for everything that was in your letter, the half of which I do not expect to answer here ; for it would take all my paper, and I wish to chat with my poor, dear sick child. I will answer or arrange all the affairs of the letter with our He is continually doing something to make us love Him, He turns 0 ir very afflictions and privations into benedictions. You experience this, I am sure, many times each day ; but how particularly sensible was it to you after you had been so long deprived of His corporal presence. You have no idea how interested our dear Mother Agnes is for you. Besides one general Communion which she had offered for you, she has allowed several sisters to offer particular ones ; which, many of them have assured me, they do daily for your dear community. 1 have long prayed daily and begged prayers for your dear Mothers Gabriel, Andrews, &c. ; but since I have your precious list, I add your attendants and especially your dear scribe. I do not forget dear Srs. I now have the list lying Do not infer from this, that the postage of the letters I receive is felt by this community. Far from it, they never mention it, and are quite delighted when I get a letter from any of my family. I received one a few days since, from my dear sister, in which she tells that she (jow sixty-nine years of age) and my beloved mother, — upwards of ninety, enjoy good health ; but that my mother's faculties are so impaired that she appears quite unlike her former self. Yet she seems to be, almost the whole time, employed in her prayers and in thinking and speaking of God. She added, that my dear mother showed almost none of this forgetfulness so common to persons of advanced age. My sister's letter is filled Mith piety ; but she is too well satisfied with the safety and sanctity of her own religion, to think of embracing the Catholic faith. The same is the case with my poor mother and all the family ; but they are surrounded by Protestants and see no Catholics, and have very little opportunity of obtaining information. They all, i. e., my dear mother, sister and children, desire much love to you and to each member of our family. Often raise 3'our heart to our merciful Lord for them, for me, and for all our little family, w^ith each of the communities to which we severally belong, with the intention of obtaining f jr us, all that which you desire and ask for yourself and your dear CDmmunity. Your precious letter was read out in recreation, where we could converse freely on it ; your ages, entrance into religion, professions, &c., observed ; wliicli made lis quite acquainted with you all ; and I have messages sufficient to fill a pretty long letter ; but as there is no room, I must say in one word that all and each of this community desire a great deal of cordial love to you, &c Your favor of September 6tli was received several weeks since, l)ut I have been so closely employed preparing our scholars for the annual exhibition, preceded by a public examination, that I could not write sooner. It is true, the exhibition was the 14th inst., but since then I have been so closely bound to the pen, as I was before to class But to your dear letter. Sincerely do I thank the blessed Lord for the improvement in your health and for enabling you to attend the retreat. Holy Mass, to communicate in the choir and to go sometimes besides, to visit your adorable spouse and to make your meditation in His presence. As long as he allows you to do it, improve it faithfully yet prudently and only in obedience, thanking Him for it ; and when He deprives of this or any other favor, thank Him also for that ; bearing in mind that you may please Him more by resignation than enjoyment. Do not forget in your long and tedious sickness to strive to gain all the merit that your spouse intends you should derive from it, by frequent interior acts, particularly of meekness and resignation ; for these, whilst they fortify you to bear all with sweetness, will obtain for you that recollection v»hich, (a long time ago) you complained that you needed. Do not even bear your pains through custom, and because you have become inured to them, but because our Lord is pleased to send them ; frequently recollecting that He stands behind the lattice, looking on and counting the degrees of glory He is to obtain from each. Thus borne, they will become His treasures, of which He will boast, as having been acquired by one so miserable, in whom His grace has so powerfully operated. But should you, growing weary of your long-continued indisposition, fail to offer them or to resign yourself willingly to them ; then the graces which your spouse had prepared for you and which would have obtained the application of a multitude of His sacred merits to your soul, will pass by to some one who is more recollected and more watch- fully attentive to increase his love in her heart. I fear I am speaking too seriousl}'-, Avlien I ought rather, recreate to my poor sick child ; if so, 3'ou must pardon me, for I consider this (sickness) your time of harvest, in -which you have an opportunity of storing up provisions for a long journey, and even for a time of famine, — which may follow. It is a very common notion that a poor sick person must be recreated and her mind relaxed by telling and showing her a thousand things, to which her state of debility renders her unable to attend, so as to be of any service to the community ; consequently it would be better for her to inquire only about the little things in which she can employ herself. Then she will have time to make the little simple acts which are so beautiful in the sight of her spouse ; in return for which He will recreate her interiorly by a thousand pious and cheerful thoughts ; so that oftentimes, a glance at her crucitix will fill her with spiritual joy. You say, my dear child, in your last letter that the fear of not profiting by your sickness gives you much uneasiness . He requires that you remain quiet, tranquil and resigned to His holy will, recreating yourself with Him, by making acts, as I have suggested above, without inquiring or even thinking how or wiien your sickness will terminate ; — for such thoughts produce anxiety and destroy resignation. Stay there contentedly to please Him, and have or form no plans of your own. Let him plan and direct, — you submit. And if you wish to please him exceedingly, be pleased with what He ordains for j'ou. This will at once cut off a million of distractions, and draw Him to your heart, wiiere He will remain if only you attend to Him and entice Him to stay by these little simple acts of love and resignation. I had it copied word for word from a copy printed in French, and our Sisters from Lyons, where the devotion w^as common and well known, say it is authentic. If I could command my time I would perform the devotion fifty times a day to release the poor suffering souls from purgatory ; telling them that when admitted to the adorable presence of our Lord, they must praise and glorify Him for me and all mine, obtain the entire conversion of us and multitudes of other sinners and the release of other suffering souls. I endeavor to say them at least twice a day — sometimes more. On the feast of St. Ursula our mother allowed me to beg a Mass for my Ursuline daughters and sisters, which our confessor willingly said ; and I w^as permitted to communicate for the same iutentiou. I am sorry our beloved Mary's portrait was not sent to Quebec ; but I do not wish it sent to Mobile. Should your sister Josephine ever have an opportunty of sending it north, I hope the good mothers will keep it :— at any rate, I do not wish to have it. I trust she is a saint in heaven, and that is enough. Your sister Josephint^'s health has improved, and I believe, re-established. You seem to regret that you cannot, with your good mothers and sisters say the beads for this community. Such a privation will not exclude you from participating in the benefit, as In religion all is in common ; besides, the obedience and privation afford you double merit, and one act of resignation is better than the saying of twenty prayers of beads without such resignation. And so your breaking out is worse ! Poor Job ! Profit by it as he did ; and if your superior will permit, continue to take the burdock root' syrup. It will eventually cure you, unless it be a visitation from God, by the continuation of wdiich He wishes you to merit crowns for heaven. Your sister Josephine is now preparing,— that is cutting and drying a great quantity to send us, as we do not succeed in raising it in this climate. Perhaps your humor proceeds from dyspepsia, with w^hich— from your vomiting — I conclude you are troubled. Some weeks ago I was attacked with it ; which, one of our scholars discovering, she brought me a bottle of " Extrait d'absinthe, " directing me to take a small tcaspoonful three times a day, in a little water. I had never seen or heard of the medicine before ; and had not much faith in its efficacy ; however I tried it and was cured in a few days ; though I w\as obliged to avoid taking much fiuid— such as tea, coffee or souid— on my stomach. As it is a French medicine you may be acquainted with its \-irtues. I was so much engrossed by school and monastic duties about the time I last wrote to you, that I remember neither the date nor the contents of the letter. I have been under the impression that in it, I told you of the death of my dear mother ; though, within a few minutes past, I begin to doubt. If I did not, I have been guilty of a great oversight. However, knowing it will afford you consolation, I will transcribe a part of your aunt Charlotte Glover's letter, written August 14th : " Our dear aged mother departed this life on the 10th of the present month, at 6 o'clock P. M. She had been gradually declining since January. In March and since that time she was mostly confined to her bed. Her mind, though impaired, (that is, enfeebled) w^as uniformly calm and peaceful, and she perfectly resigned to the Avill of her Heavenly Father, not ex])rc.ssing a wish to continue longer or depart, only in accordance ^vith His holy will. Death to her was apparently like an expiring lamp, without a struggle or groan, aged ninety years and one month. We have a strong faith that she is at rest; and we can look in a better world, &c., &c. " Charlotte, after saying considerably more about the death of my beloved mother, continued : " When you last wrote dear Abey was very sick ; but I conclude she has recovered or you would have written to inform us. I hope soon to hear from you and through you from each of the children, to whom we all unitedly, send much love, and pray that though separated on earth we may be united in heaven. " I feel that the many prayers which have been offered for my beloved mother were not lost, and that the resignation she practiced, not only during her last sickness, but through life, under the severest trials has obtained mercy for her. I beg that you and all will pray for her, &c., &c. SR. M. AUGUSTINE BARBER. Many thanks for the prayers you offer for your brother Samuel, your sister and myself ; for they with their bad health, and I with my multiplicity of liitle infirmities and slender stock of virtue, need them much. And if you wish to know with what devotion I should be best pleased, — what I would prefer your offering for me, I will tell you quite simply, believing that your fervor and satisfaction will be increased by the conviction that you are gratifying your aged mother. Then, my dear child, make for me some practical acts of resignation to the holy will of our Blessed Lord each day ; and in saying the office and in performing the other duties marked by our holy rules and constitutions, include me and all mJne in your offering ; and then perform them through a spirit of obedience ; keeping the mind, will and heart subject, for the love of Him who submitted unreservedly, lovingly and perseveringly to all those whom His eternal Father permitted to command Him. Keep your mind humble and tranquil ; remembering that our Holy Father (St. Francis de Sales) says that a little performed with great love is better than a great deal performed with little love. I, through necessity, perform a great many exterior duties ; and much do I apprehend, that when weighed in the justice of God, they will be found wanting in love. I am even confident that nothing but obedience (in which I have implicit faith) and the mercy of our good God can save me. Pray for me in the manner I have named above. Sister MARY BENEDICTA, of the Ursuline Convent, Quebec. Sister FRANCIS-XAVIER, also of the Ursuline Convent of Quebec. Sister MARY ST. JOSEPH, of the Ursuline Convent, Three Rivers, SISTER MARY BENEDICTA Mary, the eldest child of Virgil Barber, was born in January, 1810. After spending some years in the Visitation Convent of Georgetown she went to the Convent of the Ursulines in Boston where she took the veil on August 15th, 1826, and made her profession two years later, in 1828. After the burning of the convent near Charlestown, whither the Ursulines had moved from Boston, and several fruitless attempts to re-open a school in the same city, Sister Mary Benedicta entered the Convent of the Ursulines in Quebec in 1844. She died in the same convent in 1848 at the age of 38. Quebec, Nov. 29, 1880. " Let me tell you my Souvenirs of your angelic sister, Mary, our Mother M. Bcuedicta. When I entered the convent as a pupil in 1835, Mother M. Benedicta was teacher of English grammar and literature. Active, energetic, zealous, she spared no pains in advancing her pupils. Above all, she sought to insinuate a spirit of piety, and that with such warmth from her own heart, inflamed with the love of God, that I, for one, can certify that her sweet lessons were never forgotten. How often have I cited to my own pupils her lucid remarks, her judicious observations while I made the eulogium of my dear English teacher as of one in whom I had found combined every perfection ; or, as I have expressed it in 'The OUmpses of the Monastery, '"she personified the three graces, who in her were not only christian but eminently religious. How well I remember that last year of her teaching, when already the malady which deprived us of her services, had begun its fatal inroads upon her constitution ! She was at the time first mistress of the half boarders ; (I was second). She had succeeded in introducing among them the confraternity of the ' Children of Mary. ' How ardently she continued to labor in spite of her sufferings ; concealing them as much as possible, — coming to class in the intervals of comparative repose, and struggling to perform her usual duties as if in health. It was only by order of the physician that at last she consented to take her bed, little foreseeing even then, no doubt, that it would be her death bed. I was young, and I felt my incapacity to succeed her as teacher of the first English class. But how kindly she aided and encouraged me as day by day I w^ould come to her bedside for her instructions ! How often on these occasions would she involuntarily betray the secret of her own piety and of her constant efforts to benefit the souls of her pupils, while she w^ould suggest to me the utmost purity of intention, and show me how to do that double w^ork which is the aim of the true religious teacher. Later, in my still frequent visits to the infirmary, dear mother M. Benedicta always appeared to me the model of a religious invalid ; but how sweet was her smile of recognition ! how edifying her resignation to the adorable will of God, who orders all things for our good ! The seat of her malady seemed to be in her back, between her shoulders. There poultices were applied to ease the pain during many long weeks. One day I beheld the painful sight as the infirmarian was tenderly dressing the many ulcers that covered her poor back. I could never forget it. It seemed to me that I could see the sacred body of our blessed Lord after the cruel scourging. Speaking of the dear departed, our Rev. Mother said to me : 'I was privileged to Tvatch with her the night before her death. Another Sister watched also. While the latter had gone to take refreshments, the dear sufferer noticing me near her, told me in her feeble, dying voice to go and take something also. ' How habitual must have been her self-forgetfulness. It was like herself indeed, to think ever of the wants of others and not her own. At last the long martyrdom drew to a close. With angelic piety our dear sufferer had received the last sacraments, and still lingered, — waiting the bridegroom, coming. The long prayers for the agonizing had been said, and still the feeble lamp continued to give out its flickering light. The bridegroom tarried till May 9th (her father's birthday). On that morning I entered the infirmary just in time to join in the last prayers we could say for our beloved Sister. I knelt just near her, and saw her raise her feeble emaciated hands to make the sign of the cross as I began the litany of the Blessed Virgin. Bringing her two hands together as we are wont at the beginning of the Divine Office, she bowed her head and expired, recalling to my mind, by her attitude and the sweet expression of her placid countenance, the expiring of our dear Lord on the cross. Yes, dear sister, your beloved Mary, after a long year of suffering endured uncomplainingly, passed to a better life, leaving us to deplore her early loss, whilst we treasure up with consolation the souvenir of her piety, her zeal for the observance of the rule and the good of souls, her labors in the Institute and the edifying example of the daily practice of every religious virtue. " On September 11th, 1878, my Sister Abey (Sr. Francis-Xavier) cele brated her golden jubilee of religious profession. This was only eighteen months before her death. She was even then, an occupant of the infirmary but went down to participate in the Community fete. The refectory was festooned with green, and in a conspicuous place appeared the cipher 50 wrought in flowers. They presented her with gifts and tokens, and the Sisters sang for the crowning, some beautiful verses of their own composition, some also, composed by Rev. T. Hamon, S. J. In November, 1879, a severe stroke of paralysis left my sister helpless, speechless and unconscious. Extreme Unction was administered and she remained in this state until December 8th, the feast of the Immaculate Conception, when being restored to consciousness she had the happiness of receiving the holy Viaticum then and several times afterwards. " Although I answered your last letter in due time, I feel that you must be anxious to hear again from your dear suffering sister. She is still lingering on her bed of pains ; but apparently the hour of her release is at hand. From the time you last heard from her there has been little change in her state until now. She has remained completely helpless ; and although sufficiently conscious to understand what is said, she has never recovered the faculty of speech beyond a word or two at a time. This degree of consciousness has been to her a most precious boon, enabling her to join in the prayers, offerings of herself and her sufferings, the tender aspirations, &c. , suggested to her by her indefatigable infirmarian, who has scarcely Cjiiitted her side, by day or night since the commencement of her illness. This dear soul, Sister St. Charles, is your sister's special infirmarian ; having volunteered her services from a sense of special gratitude — (having been her pupil in music in former days) — and were she waiting on her own mother, or on our Blessed Lady herself, I do not think she could do it with more affection and devotedness. Her services had been required indeed, our infirmary being very laborous and visited by death ; on which account the dear invalid has been transported to another infirmary, the old Novitiate, — the very apartment where she commenced her religious life. A few days ago, your good sister received again the visit of our dear Lord in holy Viaticum ; and on Friday, February 2Tth, Extreme Unction again. Yesterday she had a turn of weakness, which brought the community around her for the prayers for the agonizing ; and these have been reiterated in part, since, as well as the visits of her confessor, &c., which have been frequent throughout her illness. Wednesday, March 3. My dear good sister, you are prepared, are you not, to hear that all is over, that all is at rest, — that the poor weak frame has sunk, and left the soul free to wing its eager way to the bosom of its God ! Yesterday evening at about half -past eight, the last symptoms appeared. Our dear Mother Superior was again at the bedside of our beloved sister, with a part of the community in prayer, accompanying the departing soul. It was about eleven o'clock when the last feeble breath told that the oft-invited bridegroom had come for His faithful spouse. Her whole life had been spent in the house of the Lord, in innocence and fervor. All the precious moments have been reckoned and each has received an abundant recompense. The sufferings of a long and painful malady alone w^ere needed to complete the splendor of her crown ; and these have been plentifully supplied with consciousness to profit by them, and the comforts of symjiathy and religion to alleviate their bitterness. The grand office at the funeral, Masses, Via Crucis, Communion, &c. Surely our dear sister will take a legion of souls with her, by sharing with them the surplus of her spiritual riches. The burial will take place to-morrov7 morning. I enclose a little heart worked by our dear sister. May our blessed Lord himself comfort your loving heart ! You will kindly let us hear from you soon. Our Bev. Mother and Community unite with me in sympathy and affection. To me you are more than a sister in religion ; you are doubly dear to my heart, being so closely connected with our beloved mothers, St. Benedicta and St. Francis-Xavier. The former was my teacher in the novitiate ; the latter Avas my sister and spiritual daughter ; and as such Hid you seen how beautiful she looked you would be consoled to know that the spirit was happ}^ The change came immediately after death. We felt no repulsion in presence of the remains ; on the contrary, we loved to contemplate her as she lay on her bier. Your last letter to her caused her so much emotion that I was obliged to discontinue reading it. Owing to her loss of speech she could not express her sentiments, but her sobs and tears spoke her love for her only surviving sister. She often spoke of you and the other members of her family. During, her mother's life time she often showed me her letters, which I found admirable. Would it be asking too much, dear sister, to have some of your sister Susan's writing and the account of your parent's conversion ? We will be so grateful for it. Be kind enouo-h to pray for our dear M. St. Agnes who died a few hours after your dear sister, St. Agues. Many thanks, dear sister, for your sweet little picture, which possesses great value for me, as it comes from the beloved sister of our dear departed one. Thanks for your kind words in Mere St. Croix's letter. It is very true, that I would not have done more for my own mother; but had not she been always a kind mother to me from my childhood ? The dear invalid suffered a real martyrdom ; but always patient and ever cheerful. Her piety was most edifying. It was my pleasure to notice the holy expression of her countenance each time I would suggest some aspiration ; and whenever I appeared to forget the morning or night prayers, she would point to the holy water to remind me of my duty. Whatever she desired was granted by the tender care of our kind Rev. Mother Superior. I am glad her sufferings have come to an end, but I miss her very much. Her cell is mine now ; and the pictures are left just as she arranged them. A little one representing the Blessed Virgin with the child Jesus, was at the foot of her bed, in the folds of the curtains. She loved to look at it ; and when I said the words, printed by her beneath this picture : " Mary, my good mother ! " she would repeat them after me, her lips trembling with emotion. Oh ! I now hope she is with her two blessed mothers in heaven, praying for you and for us all. Adieu, &c. The reader will remember two letters written by Rev. Samuel Barber, giving an account of the illness and death of his father. The extract of the Catholic Mirror, which we reproduce, and the two following letters, will convince us that Rev. Samuel Barber was not an unworthy son of his admirable and saintly parents. Samuel having finished his noviceship at Whitemarsh, Md., left for Rome in August, 1832. He remained in Rome about eight years. On his return he was stationed successively at Georgetown, Frederick, Washington City and St. Thomas' Manor, at which last he died, February 23, 1864, aged 50 years. The Rev. Jesuit Fathers wrote as follows : Although not personally acquainted, I write to give you some particulars of the life and last illness of your beloved brother, our superior in this mission ; for I feel sure you will be pleased to hear something about him from one who witnessed during the last six years of his mortal career, the many virtues he practiced. In his private life, as a religious he was very exact, and required the same exactitude from those under his charge. He was very obedient to his superiors, and I do not remember to have heard him at any time, complain of their dispositions. As a missionary he labored strenuously for the salvation of souls. Although attentive to all, the poor were the foremost object of his thoughts and solicitudes. Father Barber was takca sick with a severe cold in January. A few days later he was attacked with typhoid fever, the symptoms of which soon became alarming. The two doctors, however, got control of the disease ; the patient began to improve and was considered out of danger. On February 21st a sudden change took place and all remedies proved unavailing. He calmly expired on the 23d, 1864, aged 50, after having received the sacraments. We have every reason to hope his death, though a great loss for us, is a gain for him, and that he is enjoying the reward of a life well spent in the 23, 1864, Rev. Samuel Joseph Barber, in the 50th year of his age. He w^as born on the feast of St. Joseph, March 19th, 1814. His father, V. Barber, and his grandfather, Daniel Barber, were Protestant ministers, and subsequently converts to our holy faith. His father having become a priest of the Society of Jesus, and his mother a nun of the order of the Visitation, Samuel Joseph, who was then very young, was placed at Georgetown College, D. C, where he graduated with honor in his 17th year, and immediately entered the Society of Jesus, After two years of novitiate, made partly in Georgetown College, partly at Whitemarsh, Prince George's county, Md., he was sent to Rome, where he repeated Philosophy, studied a full course of Moral and Dogmatic Theology, and having been ordained priest, returned to his native country in 1840. Distinguished by the requisite talents, learning and virtue, he was in due course of time admitted to the solemn profession of the Four Vows, the highest grade in his order. He filled with ability and success the various oflQces of vice president and professor of Georgetown College, master of novices at Frederick, President of Gozanga College, Washington, and pastor of St. Thomas', Charles County. Of a clear and cultivated intellect, of a pure and devout heart, and of zeal always active and fervent, he possessed in no ordinary degree "the wisdom which the lips of the priest should keep," and "the holiness that becometh the house of God. " The ignorant whom he instructed, the guilty whom he reclaimed, the sorrowing whom he consoled, the poor whom he assisted, the pious whom he led to greater sanctity by exhortation and example, the religious and especially the priests, who received from him their first lessons in the Science of the Saints, have reason long to remember him not only tearfully but prayerfully, now that the term of his trial is over and he is gone from the scene of his toils on his journey to the theatre of his triumph, from his ministrations at the humble altars of earth, to worship at the grand altar of heaven. In his person, that branch of the Barber family of which he was a member, has been gloriously terminated by the Priesthood ; for he was an only son, and his sisters, four in number, all imitating the lofty example of their pious mother, became cloistered religious, God richly rewarding by so sublime a vocation, the self-sacrifice of their father and grandfather, who, despite the puritan prejudices of a Kew England education and the strong ties of blood, friendship and association, severed their connection with the Protestant ministry, and sought religious truth and peace where alone they can be found, in the bosom of the only spouse of Christ, the Holy Roman Catholic Church.— K. I. P.— [Catholic Mirror. Beloved and affectionate mother : Must I again repeat the old storj'— "I had no time"— in order to excuse my long delay in answering your affectionate letters Aug. 28 and Oct. 21, 1833 ; which a mother's heart might have imagined long ao-o at the bottom of the ocean, rather than suspect her son could have been so long deaf to the calls of filial duty. Xo, I have not written ; the letters have not been lost ; so much I confess. To the last conclusion let your maternal heart answer ; it cannot but defend me. During the last scholastic year I have applied to the study of metaphysics and mathematics, under excellent professors, as no doubt you must have learned from me on some former occasion. Last August I underwent the usual examination in both branches ; and at the commencement of the new scholastic year, — that is about the beginning of November, I was put to study the second year of philosophy. The delight, it is true, arising from the studies of the second year much surpasses that which is experienced in the dryer study of metaphysics and the lower branch of mathematics ; but the labor increases in proportion to the pleasure. Last year we had but two professors ; this year we have three. You no doubt remember once leading me to visit youv famous Odeon, that whilst showing me a variety of mineral specimens, together with your physical and chemical apparatus, you asked me whether I felt no interest in these studies ? showing thereby a sort of wish for me to apply to them. Behold your desire fully accomplished ! for the chief studies that at present occupies my time and attention, are those of physics and chemistry. Our professors arc excellent. The professor of physics made his studies in Paris, under the most celebrated professors of the present day in France. Our professor in chemistry has lately written and pul)lished a treatise on this subject in four volumes— in Italian. The work is very much esteemed, as well for the beauty of the language as for the chemical knowledge therein displayed. I have often wished it were translated into English that I might send you a copy. Our fathers in Georgetown have the first two volumes in their library, and I expect the others to be sent on shortly from Rome. You might perhaps be able to induce some one at the college to translate them for you. think myself well off. You must have noticed, — and not without some surprise, that my letter is not dated from the Roman College but from the College of Nobles. Too true, indeed ! The scholastic year had scarcely commenced, when the prefect of the large boys in the said college w^as obliged to resign his post, in order to take the priesthood. I was sent to fill his place. Although I find my hands full, nevertheless I feel perfectly contented. Moreover, I am far from thinking my time lost in having to watch, the whole day, over the boys entrusted to my care. Of this very duty I form a new and very diligent study, applying myself to learn the character and inclinations of youth ; an art difficult indeed, but which undoubtedly, will be of great service to me on my return to my native country. Besides, the order, subordination and good heart of the Italian youth, serve in a great measure to render light a burden which of itself might be calculated to oppress me. I received one letter from Mary, Abey and Josephine, and two from Susan since writing to them ; all dated 1833, except Josephine's, which was dated 1834, the only letter she had written me since her leaving Georgetown for the west. All these letters are as yet unanswered. From father I received a letter about tw^elve months ago, in which he promises me a copy of the philosophy which was to be printed soon. This, however, I have not yet seen. The news of Susan's illness might perhaps have given me some cause of grief, had I not learned how "•reat was her fervor and how faithful her correspondence with the "•race and designs of God. Happy indeed, is she (and I envy her happiness) persuaded as she is, that the only sure way to heaven is the royal way of the cross. I cannot express the great satisfaction I felt on reading the copy of her letter which you sent me. Father Kohlmau, whom I see of tener this year than before, shows great affection towards the whole family, and speaks often of father and mother. He has become old and his limbs tremble a great deal, but nevertheless he still labors much for the conversion of souls insomuch that he has not a spare moment. He did net fail sending me the letter you wrote him. He returns many thanks and hopes you will write often ; but bids me tell vou beforehand, you must not lie surprised if he is unable to answer SISTER MARY ST. JOSEPH. The reader must remember the very kind letter which Rev. Virgil Barber wrote to his dear Susan on December 31, 1836, She died a few days after receiving that letter. The reader must also remember the letters written by Rev. Samuel Barber on the occasion of her death. We have found nothing written by Sister Susan herself. She entered the boarding school of the Sisters of the Ursuline of Three Rivers, May 21, 1830, and remained six or seven months only. As her education was so far advanced, she was allowed to put on the habit of a postulant as early as December 8th, 1830. She took the white veil on March 19, 1831, under the name of Sister Mary St. Joseph, and made her profession as Choir Sister on March 19, 1833. She alv/ays remained the model of the other religious, both before and after her profession. She was remarkable by her fervor and her generosity in the practice of all the virtues becoming religious, and especially that of holy obedience. Need we wonder that this flower of the cloister was so early in life gathered by the heavenly spouse ? REV. AVILLIAM HENRY HOYT. With the heart full of tender emotion at the remembrance of dear Father Hoyt, we begin compiling the following sketch of his life, from his own diary, the information received of some of his friends and relations, and also from our own personal recollections. On the 8th day of December, 1883, " at his own desire, he sang the High Mass on the Feast of the Immaculate Conception (at St. Anne's Church, New York). During that Mass it was noticed that he appeared very strong, and sang with extraordinary vigor, a few moments only before the stroke of death seized him. He gave himself his own viaticum, opened the tabernacle, said the misercatur and indulgcntiam. Those were the last words he ever spoke ; his hands fell, he turned with his last strength to the altar, and gently fell before it." (Father Preston, in memoriam Wmilliam H. Hoyt) We had known him, loved and venerated him during many years in Vermont, but his death, so precious before God and man, made him if possible dearer to our heart, and we humbly beg God's grace to enable us to make him better known, so that others may be encouraged to walk in his steps. William Henry Hoyt was born in Sandwich, New Hampshire, on January 8th, 1813. He was graduated at Dartmouth College in 1881, and after pursuing a course of study at Andover Theological Seminary, Andover, Mass., and at the general Theological Seminary, New Clmrcli by Bishop Griswold in 1836. After his ordination he was for a year or more employed as professor in Bishop Hopkins' Seminary in Burlington, Vt., where he made the acquaintance of his future wife, Miss Anne Deming. copal Church of Middlebury, Vt., where he remained about a year. Young as he was at this time he was already remarked on account of his talent and virtue. One of his early acquaintances, (Bishop Wadhams of Ogdensburg) writes thus of him : " I loved him and confided in him, and followed his advice in regard to reading religious books ; but he had nothing to do with the college where I was." What we most admired in our venerable friend was his prompt, generous obedience to the call of Divine grace. His habitual disposition was that of Saul prostrated on the road to Damascus : "Lord, what wilt Thou have me to do ? " He was a Protestant minister, and told us that "he was never satisfied, as to the doctrine and origin of his church ; he was as yet in darkness, but willing to folloAV the light ; and resolved to seek it and to use every means in his power in order to obtain that grace." On April 11th, 1843, he wrote : "Visited sick child and baptized it ; attended evening prayer at 3, preached No. 251 . . . was very faint from protracted fasting and labors, not having eaten yesterday or to-day till evening. " On April 12th. " Read the morning prayer, took some slight refreshment this noon after sacrament, being admonished by yesterday's experience, and also of former occasions, that my strength will not bear me up under so much writing and performance of public service without doing so." On Sept. 27th, 1843. " For more than a week past excitement of Convention, absence from home and company and disturbance of habits of devotion, have put me off my guard, and I have been more than usually careless, and have more frequently and greviously sinned. Especially my thoughts have been unregulated, and I have been unguarded in my conversation. And to-day I have been very wicked, both in thoughts and also in outv/ard conduct. If I am to meet with such relapses much more, after seasons of earnest strictness and fidelity, what is to become of me ? My account at the last will be dreadful indeed. Let me therefore put this here as a record, from which to start anew ; and endeavor for all coming days that may be yet allowed to me, to be more constant and unerring— to guard better my thoughts Ash Wednesday, Feb. 5th, 1845. " Read Mr. Newman's sermon on Life the season of repentence." Vol. 6, sermon 2d. Took a single cup of coffee, and a small piece of toast in the morning to sustain me through the service, and Wmn fasted till erening. " On Thursday, January 8th, 1841. This is my birthday — 33 years old to-day. Time flieth away — and it is short— 'converse in fear during the time of your sojourn here. ' " August 21st, 1845. " This is the anniversary of our marriage. Seven years ago to-day, my dear Anne and myself were happily joined in holy wedlock, and a happy union has it thus far proved to be. May it ever continue to be so, and ?nai/our Lord make it of long continuance, if it shall so please Him." From the preceding extracts of Mr. Hoyt's diary, we see how earnestly he endeavored to serve God whose laws he seemed never to forget. The congregation of which he had charge at St. Albans was small, and made up of families well to do in the world. To the spiritual welfare of this flock, he devoted himself in the best way he could, visiting and consoling the sick and the dying, baptizing the infant children, preaching from the pulpit, etc. We could not but notice in reading his diary, how careful he was to procure the decoration of his church and especially how great care he took in teaching his choir, and selecting the music suitable to the different festivals and seasons of the year. We stated already that Mr. Hoyt told us that he never was satisfied in the Protestant Episcopal Church of which he was a minister. In crder to obtain light concerning the all important subject of religion, he applied himself to lead a very good life ; and to implore the guidance of heaven ; and moreover he spared no money in order to procure the books and papers published in England at that time by Dr. Pusey and his disciples. December. Saturday, 2d, 1843. "We certainly are li\ing in trying times, and times fraught with anxious yet obscure forebodings of the future. Divided, distracted, and (humanly speaking) guideless. What is to become of us ? God knows, and He surely is ordaining all On 28th December, 184a,he wrote : "Took up Bishop Mcllvainc's last charge to his clergy, lie may be well taken as a specimen of the modern (so called) Evangelical school. If it were not for the reflection that our blessed Lord has Himself so fully shown the true temper, tenor, teaching and truth of His gospel, in the four gospels or narratives of the Evangelists, and that we have His sure promise, to-be always with His c'lurch, to maintain that gospel in it, one might well be distracted and discouraged at seeing such writing ex cathedra." On the day following, December 29th, 1843, he read a book of which he writes: "Read to Anne St. Thomas Becket's life from Butler (Lives of the Saints) this being his Calendar day. A good and holy man, as he w^as confessedly great and influential. But it is the temper of our age, wholly to misunderstand such men." Mrs. Anne Hoyt, his admirable wife, had investigated the claims of the Catholic Church with as much care and earnestness as her husband. She was in fact more anxious to enter the church than her husband, and seven months before her profession of the Catholic faith she signified by note to her sister, (Mrs. Maria Tucker) her intention of entering the Catholic Church. Our venerable friend continued his investigations and prayers. He read with serious attention the writings of Dr. Newman, Brownson and others bearing upon the subject, corresponded with Dr. Pise of New York and others, and sometimes as occasion offered itself visited Catholic Churches, attended its services and conversed with Catholic priests, towards whom, as he declared to us, he could not help bat to feel attracted. On December 30th, 1845, he " wrote to the wardens and vestry of the parish resigning the pastoral care of the parish." On this occasion contrary to his practice of merely writing down facts, in his diary, we find recorded the following short remark : " Much feeling occasioned among my parishioners, by the step, and feel not a little moved myself." Our venerable friend had for successor in the charge of the Episcopal Church of St. Albans, the Rev. Mr. Perry, of whom he wrote in his diary : Februaj-y 13th, 1846. " Mr. Perry read (at matins) as usual, and I sat in the organ gallery. Mr. P. is now fully rector, having been formally invited by the vestry and having accepted— so my powers and responsibilities have entirely ceased." A remarkable trait in his character was generosity, which I would rather call prompt obedience to the call of Divine Grace. He had for a long time investigated and pra5'ed. All his doubts had disappeared, and time to enter the church had arrived. On July 34th, 1846, he sent a communication to Bishop Hopkins, containing a renunciation of the Protestant ministry, etc., and on the evening of the same day. left in the boat for Montreal. " S5th JULY, 1846. " Arrived at Montreal at 10 A. M. At half-past twelve had an interview with Rev. Mr. Richard, and soon after was admitted to confession by him in the chapel of the Seminary of St. Sulpice, received conditional baptism from his hands, the Rev. Mr. Connelly being present, and made my profession of the Catholic faith, after which having done the required penance, received sacramental absolution ; went with Mr. Connelly to Bishop Bovirget, had an interview with him and asked and received his blessing. By advice of Mr. Richard am to make my communion early to-morrow morning." On July 36th the newly baptized convert " rose early and went to the 5 o'clock Mass, at the large Parish Church. Rev. Mr. Richard said Mass, and with numerous others I received the Holy Sacrament — Our fervent convert spent the rest of that blessed day in attending solemn High Mass in the Cathedral r.nd Vespers in the Parish Church of Kotre Dame, and in the evening went again to confession. On the next day he went to the early Mass and again received communion. From the intimate acquaintance we Lad with our friend, we sincerely believe that from the day of his admission in the Catholic Church to that of his death he had not so much as a doubt in matters of religion. But at this time of his Catholic baptism, how could he forget his dear wife and children ? Having spoken to the Bishop of Montreal, Mgr. Bourget, of her anxious desire to enter the church, the Prelate gave him a letter for Father Mignault, parish priest of Chambly on the Richelieu, and the devout convert went immediately to Chambly to see the reverend father to makC arrang'ements for the baptism of j\Ir.s. Iloyt and children. He was wamly received by Father Mignauh, and made arrangements to go to Burlington and bring his family to Chambly on the following Friday.* Mr. Hoyt according to appointment arrived at Chambly on the next Friday with his wife and children, and in the afternoon went to visit the venerable pastor. We will let him speak of the events of this precious day. August 1st, 1846- " Early this morning Anne and myself attended Mass with Charles and William (the two older boys). P. M. Anne went to confession, made her solemn profession in the parish church (St. Joseph's) in the presence of Mr. Mignault and Mr. Provencal, and received conditional baptism with the full ceremonies. In the eveningBishop Bourget arrived from Montreal — went to confession myself. " On the next day. " Anne and myself attended the Bishop's Mass and received from his hands the Sacrament of the Holy Eucharist. After the Mass the Bishop administered to both of us the sacrament of Confirmation. We did not attend the Parochial Mass, but at its close, the congregation being desired to remain, we went to the church and the Right Reverend Bishop baptized our children solemnly before the high altar. The three boys conditionally and the babe for the first time. We all dined at Mr. Mignault's with the Bishop and those who had stood sponsors. " Our stay at Chambly was very pleasant. The place is beautiful for its natural scenery, and altogether we have brought away with us, feelings and recollections and associations never to be forgotten. " Mr. Hoyt remained with his family at St. Albans after his baptism till the year 1859. He was not now" a Protestant minister, but a layman in the Catholic Church. Here in his own quiet w^ay he began and continued to do what all good Catholics should do. 1^, With regard to himself he was most punctual in observing all the laws of the church, but he even did more than what is commanded. He acted according to the spirit of the church, going to Mass every day when it was in his power, and receiving holy communion several times every week. At the close of his life he received communion every day as the early christians did. To him it was immaterial who the celebrant w^as, or who the priest who could hear his confession. For over a year after his baptism, there was no residing clergyman in St. Albans, and then when a priest would come thither from other parts, j\Ir. Hoyt * Kcverend Father Mignault, the venerable parish priest of Chambly, may be said to be the first missionary of Vermont. At the time of Mr. Iloyt's baptism he was Vicar General of the Diocese of Boston ; a dignity which was conferred also on him for the Diocese of Burlington at the time of its erection in 1853. would invariably improve the opportunity by receiving the sacraments, and hearing Mass, whether said in a hall or a private house, and sometimes following the priest to other missions in the neighborhood of St. Albans. respectful towards them. With regard to the care of his children we have learned from a certain source, that after his baptism he never failed to say one decade on the beads every day for each one of them, so anxious was he to procure their santification and perseverence ; and he never spared any sacrifice in order to have them educated in Catholic colleges or convent schools. One of his most sweet practices of devotion was to render thanks to God on the recurring anniversaries of the birth, baptism or first communion of his children, to offer communion for them and pray for their perseverance. In relation to his conduct towards his neighbor, although he was not a priest, he acted the part of an apostle amongst the Catholics of St. Albans. In the absence of a priest and of a place for Divine Avorship, he invited the Catholics to his house and would read good books for them also recite prayers and the rosary. He lost no time in informing the Right Rev. Bishop of Boston concerning the spiritual destitution of that distant part of his flock, and did in reality obtain a priest for the Catholics of St. Albans en the 21st June, 1847. This was the Reverend Father George Hamilton. The arrival and residence of a priest at St. Albans was for the congregation the beginning of a new life. Mr. Hoyt, as might be expected, began at once to exert himself towards procuring a church for the celebration of Mass. He was in reality the soul of the undertaking, but always under the guidance of the reverend pastor. His diary states briefly the steps he took first to procure a lot, then plans for a church and above all money to carry on the work of building. The lot of ground which they purchased is the one now covered by the church and the priest's house. When the lot was bought there was a houte standing on it. This was moved towards the west part of the grounds and fitted up for a temporary building. Here they had now Mass, if not every Sunday, at least at regular intervals, and this was the place which our friend loved to visit and to adorn, for there was the real presence of our Lord Jesus Christ, the heavenly bread, the only food, which he knew well can give life to the soul. The Catholics of St. Albans re- REV. WILLIAM IL IIOTT. 135 member well how devoutly he prayed there, and how zealously he lielped them in their devotions in the absence of the priest, and also with what care he would prepare the singing of the Gregorian chant for Mass and Vespers. The task of building a church is a terrible one, especially when the funds are not to be found in the parish. This, alas, was the case in St. Albans. The people were very poor, quite incapable of providing the necessary funds, and Mr. Hoyt knew it well. He therefore resolved to do the only thing which could be done in the case, and that was to go out of St. Albans and beg, and he visited New York, Philadelphia, Baltimore, Troy, Boston, and some of those places more than once. Troublesome as the w^ork of begging money is, we fancy that our venerable friend experienced much consolation in those expeditions, for he was everywhere well received by the clergy who were not slow to appreciate the worth of our venerable convert. He was welcomed by, and we think became very dear to, the Most Reverend Archbishops Hughes and Kenrick, as also to Mgrs. McCloskey, Fitzpatrick and others. The progress of the Church in America which he witnessed in those excursions, must have been particularly gratifying to a man so devoted to the church as Mr. Hoyt. On the 13th July, 1849, Mr. Hoyt and the other Catholics of St. Albans had the consolation to witness the blessing of the corner stone of the future editice, which is now after its completion a very fine structure. The ceremonies were performed by Mgr. McCloskey, at that time Bishop of Albany, and afterw^ards Archbishop of New York and Cardinal of the Holy Roman Church. The same distinguished prelate "preached a noble discourse, very edifying and eloquent. " Mr. Hoyt had desired the church to be erected in honor of the Immaculate Conception, and he lived long enough to witness its dedication to Almighty God, under the name and patronage of our Mother Immaculate. It was natural to suppose that Mr. Hoyt would not fail to procure for his friends and former parishioners the happiness that he and his family now^ enjoyed. In order to obtain this result, he spared neither visits, explanations, and lengthy correspondence. The letters exchanged between him and Professor George Allen of Philadelphia on the subject of the church were particularly interesting. We have counted up more than fifty persons who, at that time owed to him their conversion or education in the Catholic faith, and many of those were persons of superior education and high standing in society. Mr. Hoyt and his venerable wife stood up as sponsors for many of these, and they all loved to visit his hospitable home. He was in fact so humble, so kind and attractive, and in the meantime so learned, that he was to converts especially a tower of strength, and to all clergy and laity the object cf truest veneration. Wlien Mr. Hoyt left St. Albans in 1860 in order to go to Burlington, he left in the former place a striking monument of his zeal in the beautiful church erected chiefly through his exertions ; and in the hearts, we dare say of all, Protestants as well as Catholics, the sweet memory of his humble, charitable life. A few years after his moving to Burlington, they might see at St. Albans another structure intimately connected with the memory of our friend. We refer here to the convent boarding school kept by the Sisters of the Congregation of that village. Amongst the persons whom Mr. Hoyt encouraged and comforted in their trials when they thought of joining the church, were the now well known three Sisters, {Tlie Young Converts of Mrs. Julia Smalley) Misses Debby, Helen and Anna Barlow. To the father of these three dear saintly girls, :Mr. Hoyt had sold his beautiful property lying south across the street from the Catholic Church. In this house Anna, the youngest of the three, and Debby, the eldest, lived and died after a long-lingering illness. In this house they had been welcomed and comforted by Mr. Hoyt, both in health and in sickness. In this house also Debby Barlow had been visited and comforted in her dying hours by some of the religious of Montreal who had been her former teachers. Well, there stands now on that spot an institution of devoted Sisters who spend their lives in praying and instructing children, poor and rich. The house occupied by Mr. Hoyt has been taken down and replaced by a building suited for a boarding house and school ; but the chapel we are told occupies the site of the room in which the two dear sisters suffered and died. When in later years Mr. Hoyt visited St. Albans from Burlington, or when at a still later period he, being a priest, visited it from New York, avc well imagine how he felt rejoiced at the sight of the church and of the convent, for of him it might be said, " O Lord I have loved the beauty of Thy house, and the place where Thy glory dwelleth. " a. We have endeavored to show how careful Mr. Hoyt was to a. Kev. William H. Hoyt lived wilh us here in Burlington during- many years. He continued in this city to lead the same kind of life which he had lead in St. Albans, always remarkable by his gentleness, humility, fidelity to Deity. No one could be more punctual than he was in the discharge of the several offices which he occupied here. For some years he had charge of the organ at the Cathedral ; performing this office for some of the tmie without any remuneration. The congregation never had to complain of his absence or tardiness at the time of the service, and according to our opinion he had the gift of drawing out of the instrument, harmonies in keoping with the innocence and fervour of his soul. We always loved lo meet him M-hether alone or in company, for he could not fail to impress us with the idea that he v.-alked under the eyes of his Maker, that he felt His presence. Above all, we loved to behold him making his way to the church or to chapels in which the Blessed Sacrament is kept, in order to assist at Mass or to spend some time in prayer and adoration. We loved to see him kneeling amongst a crowd of penitents patiently waiting for his turn to enter the confessional. procure llie sanclilication of his family by prayer and good examples, and we may add that he spared not remonstrances and admonitions, when they were necessary. The few following quotations will show that he was a model of a Christian husband. His dear wife in every respect worthy of him might be seen hearing Mass and receiving her communion with her husband almost every day at St. Stephen's Church, when they resided in New York. On Sunday, January 10th, 1875, he wrote in his diary : "It was this morning that dear Anne and myself were at Mass and communion together for the last time. She was a little in advance of me, there being a crowd of communicants, and thus received first, I having to wait till the next railing was filled. She expressed regret afterwards at this ; it being her custom and her pleasure to kneel at my right side and receive with me. It was her last communion, and thus proved to be her viaticum. She was more than usually devout both at communicating and afterwards. " We have seen few married persons who so perfectly realized as they did the precept of the Apostle St. Paul. " Husbands love your wives as Christ also loved the church and delivered Himself up for it, that He might sanctify it so also ought men to love their wives as their own bodies He that loveth his wife loveth himself. For no man ever hated his own flesh, but nourisheth and cherisheth it as also Christ doth the church. Because we are members of His bod}^ of His flesh, and of His bones. For this cause shall a man leave his father and mother, and shall cleave to his wife ; and they shall be two in one flesh. This is a great sacrament, but I speak in Christ and in the church. Nevertheless let every one of you in particular love his wife as himself and let the wife fear her husband." (Eph. v. 25 and foil). Our venerable friend considered his consort as a gift from God, a gift for which he never omitted to return thanks, on the anniversaries of their marriage, communion, confirmation, etc. At the date of January 16th, 1875, we have the memorandum : "A sad and memorable day for me and my dear family, my dear wife having died this evening at twenty minutes before six. She lies to-night as laid out by the hands Mistress Anne Hoyt. " At the time of his wife's decease, the wife so inexpressedly dear to him, his first thought was for her soul, his great care that no word of loving praise should be uttered that might be a cause of temptation or disturbance to her ; that each of her children should ask forgiveness for whatever in their past lives had given her pain, himself leadinrj the icay and asking it for himself and the absent daughter ; then, vdien the sacrifice was completed, his conformity to the sweet will of God ! Oh who could portray it?" The sacrifice is over, and the afflicted husband exclaims in his sorrow : " Alas, I am beginning to realize that now I am alone. " But he was not sorrowful as those icho have no hope. In this dark hour of his life, he kept his eyes steadily fixed upon the light of faith and he followed it steadily. Mass the family were all present except N ... and N . . and we all went to communion together for dear Anne." In the afternoon of the same day they left on the 4.36 train for Burlington, "carrying dear Anne's body with them, and proceeded on their sad journey homeward to Vermont. " They arrived at Burlington at 5.30 the next morning, "the corpse had borne the journey safely, and dear Anne looked as beautiful and smiling in death, as when we closed the casket in New York." The interment was to take place on the next day. Mr. Hoyt, true to the inspiration of faith, we should also say it, guided by christian love for his departed, " rose early, went up to the convent for Mass and communion, but there being no Mass there went down to the Cathedral chapel for Mass and communion. At ten o'clock we took dear Anne's body to the Cathedral, where a Mass of Requiem was sung by Father Cloarec The following entry records an act of devotion which was repeated every Saturday for about four months, that is, as long as the family continued to live together in New York : " At 5.40 the hour at which dear Anne died, a fortnight since, we gathered around her bed, and recited together the beads for the repose of her sduI." On the day of the month-mind he had Mass offered for the dear departed, and six of the children received communion for the repose of the soul of their mother. It is needless to remark that the children of Mr. Hoyt shared in his sentiments of deep affection and respect towards their mother. The following incident will be read with interest. Mrs. Hoyt was remarkable by her industry. On the return of the desolate family from the burial of their mother, Mr. Hoyt states : "The dear children have set things in order at the house, and made it as cheery as possible considering the circumstances. A fitting motto, " Let us thrive to become like mother, " has been placed in the One week after, they closed the house where they had lived three 3'ears, and took a sad parting of the place where the much beloved wife and mother breathed her last. Mr Hoyt was at this time cashier of the Southern railroad. When going or coming from his office he would sometimes go out of his way to look at the house in which his wife had died, in the meantime praying for the repose of her soul, or he would step into a church and make the way of the cross for the same intention. The time which elapsed between the death of Mrs. Hoyt, and his entrance at the seminary of Seton Hall was for our venerable friend a time of great trial. Though he occasionally saw some of his children, the family were not living together his health was poor, and he felt all the discomfort of living among::t strangers. He did not, however in the midst of his troubles, forget the soul of his departed wife, nor the care of his family. He knew that prayer was the means of obtaining grace, and we find in one of his entries January 7th, 1879 : " At Mass and communion at 8 at St. Charles', offered for the intention of a novena begun to-day, in which I have requested all the dear children to join with me, in preparation for the 15th inst., the second anniversary of dear Anne's death. 1st. For the repose of her soul. 2d. For the final perseverance of all and each of the members of the family ; and 3d, that no one of us may by misdeed, scandal or grave sin bring disgrace upon it. " From a letter to one of his daughters in Burlington : "I am glad when you tell me all about matters and things, as also about the dear cemetery where our loved ones rest, or rather their dust, their sacred dust. Thej^ themselves, I feel new almost sure, are in the light and joys and peace of heaven, and so in the beatific vision, are with us also and see us, and care for us and commune with us. Dear consoling thought that they do so ! My hand, my heart, my abiding love and fidelity. I cannot bear the thought that any like love should come between me and her. Death, so far from separating us in this respect has only knit my heart more closely, more tenderly to her than ever. I shall yet see her again and be joined with her ; and the dear family all at last grouped around us. Our home will then be found in the place our Divine Lord said He went to prepare for us, a home that never again shall be broken up, or its members dispersed and scattered. This is my hope in Christ our loving and beloved Lord, and we will each and all of us strive, will we not, dear J . . , for its happy fulfilment." and the Seminary will close for the year. I long to go north and sec Burlington once more in its summer attire, which I have not seen since six years ago. The dear cemetery, too, I long to visit when it will he clothed in its sununer beauties, more titting to the memories of our dear ones dead, than the snow and cold wintry winds which have prevailed there during all my visits." Mr. Hoyt, however, was out of place in the world. God demanded something more of him, and the time had come that he should consecrate himself entirely to the service of his Creator, Of that long, sad night which he spent on the cars, taking for burial to Burlington, the corpse of his wife, he wrote January 19th, 1875 : " Had during the night past in the cars, while lying awake, some sudden suggestions, as if from dear Anne herself, like inspiration, respecting my future vocation, for the remainder of my da5"s. " The thought of consecrating himself to the service of God in the priesthood had impressed him ; and a feic Iwurs only after the burial of his wife he went to the Bishop of Burlington and consulted him on the subject.He consulted several other bishops and priests, and all encouraged him to prepare for the ministry. Mr, Hoyt was about 62 years at this time, and this seemed to be rather late, for some time must yet be spent in retirement and study before being called to receive ordination. On the other hand he knew Latin quite well, had made a particular study, before his conversion, of the Missale, Breviary and Ritual, as also of the music of the Church. In matters of dogma he had very little to learn, and had already given proofs of his zeal, and ability to teach ; when being in St, Albans, he to some extent supplied the parts of a priest, before one was sent thither. He now re-studied his Latin, and after returning from his ofBcc, would take up books of moral theology. Reverend Father Hoyt began his seminary life at Seton Hall on January 19th, 1876, He received tonsure and minor orders at the hands of Cardinal McCloskey in his own private chapel (April 11th, 1877). On the day following, "At 7.30, the Cardinal said the Mass of the ordination. Fathers Farley and Salt assisting, at which I received subdeacon's orders and communicated, to my r/rcat gratification." A little over a month from this date our venerable seminarian received deaconship at Seton Hall at the hands of Bishop Corrigan, and five days after he enters in his diary : " May 26th, 1877. Memorable day for me . But of my ordination to the priesthood by Bishop Corrigan. .. .My dear children were all present, also Dr. Purroy . . and so ends the day, Deo gratias for its blessings and favors." ordination of its ministers cannot but have noticed that Mr. lloyt received all the orders within an unnsually short space of time ; but he was worthy, he was prepared, and all knew it. 19th of January, 1876. " He resided in the seminary and attended the classes and exercises the same as other seminarians. His life here w^as one of humble obedience and patient study. His humility w\as very great, greater than is ordinarily seen except among fervent religious. " I shall never forget his bright and happy look after his ordination, a little awed by the dignity he had received, but it was the awe of an innocent soul permitted to approach nearer to our Lord. "You will easily understand that in a humble life like his there is little to say except that he studied, he prayed and passed the examinations like his fellow^ students of younger age and 'that he found the strength and fervor to do all so well in Holy Communion, for he received holy communion very frequently. ' " On the evening of the memorable day of his ordination Rev. W. H. Hoyt went with Father Quinn, Y. G., to the Cardinal's residence, and called on him. From whom he had a kind reception, and who gave him verbally his faculties . He was assigned to duty at St. Michael's Church, West 32d street and 0th avenue, to assist the Rev. Father Arthur J. Donnelly. We will end this imperfect sketch of the life of our very dear friend by letting Monsignor Preston relate how he lived in New York as a priest and how he died at the altar of the sacrifice, after sacrificing all himself in his life for the love of his Crucified Redeemer. ' ' No man ever felt more what it was to be a priest after the order of Melchisedec, no man ever felt more what it was to have the privilege of offering the divine sacrifice, to be consecrated to God in heart, in thought, in word, and in action. " So, little more than six years passed away. The early days of his priesthood w^re passed as assistant in St. Michael's Church, and there is only one opinion expressed by all connected with him. He won upon them continually by his patience, his gentleness, his devotion, his great humility, for, though he had before occupied so honorable a position, never was there the slightest sign of self -consciousness ; and he was only anxious to spend what strength he had for God — only anxious to give to God in his declining years all the faculties he possessed. " For a brief period he had charge, during the absence of the pastor, of the parish of Irvington and ministered to its wants. I know the children of St. Anne's love him. I know all of you love him, and his will be a name dear in the history of this parish ; and I thank God there has been one w^hose life will be always a blessed memory to lead us in the path of virtue and grace. Then think how God has been pleased to end his life. During the past month he w^as as well as usual. At his own desire, he sang the Mass on the Feast of the Immaculate Conception ; and during that Mass, you who were present were witness how strong he w^as, and even with what extraordinary vigor he sang only a few moments before the stroke of death seized him. He gave himself his own viaticum, opened the tabernacle, said the misereatur and the indulgentiam. These were the last words he ever spoke, his hands fell, he turned with his last strength to the altar, and gently fell before it. I do not know in all my experience a more beautiful ending to a beautiful life than this ! , That his last act of devotion to his Lord, and when the stroke of death came, he was bearing the body of his Lord, and the Master was on his tongue and in his heart ! I do not know a more happy death than this. " We took from him his sacred vestments, we bore him to his bed, and from that moment till yesterday, when he died, there was not the slightest consciousness. Around him w^ere continual prayers ; Masses were offered for him ; his own family were by him ; there was the sacred annointing ; and so, fortified by all the sacraments, he went home to give an account of all his stewardship. For w^e may call it home when we go to God. He is our Father and Redeemer. And so, with the gentleness of a child, he went home to sleep on his Redeemer's breast. " I need not ask you to pray for him. I know you will pray. AVe know not how infinitely pure Almighty God is. We know not— we ' never can know, wiiat is the responsibility of the divine priesthood. We know if God were strict to mark wdiat is done amiss, we could not abide it. We know^ the angels are not pure in his sight, and faith bids us continually to pray for the departed, and offer up the holy sacri- ficc of the altar to give them rest aud hasten their entrance into tlie joys of their Lord. But, at tlje same time that we pray, the lii^hts of faith, the lights of love, the lights of hope, are burning around this sacred bier, aud, if it be a dreadful responsibility to be a priest, yet the rewards of a good priest arc great, thanks to infinite mercy of the Lord. " And so we look forward to his reward, and we know he will be with the Lord he loved and served, that he will see in vision what he saw by faith, and that he will be our intercessor to pray for us and for this parish, that God will strengthen us, so that, when our time shall come, we may be ready, as he was, to go into the presence of his Judge. " So we will bear his remains to the home of his early youth, where he will rest. Among his own people we will lay him to sleep. There he will rest till the trumpet shall sound and the dead shall rise. Then this mortal shall put on immortality, this corruptible shall put on incorruption, and we shall rise in the likeness of our Lord and Redeemer. AVith these hopes, with this certainty of divine faith, may we not say, in the exulting language of St, Paul, " O Death, where is thy victory ? " O Death, where is thy sting ? " Thanks be to God, who has given us the victory, through Jesus Christ our Lord." a person in every respect worthy of our virtuous and venerable friend. From the follovNing; letter to her sister, Mrs. Maria Tucker, written some time before the conversion of her husband, the reader will judge of the generosity of her character when there was question of the honor of God and the interest of her own soul : " With regard to the question you ask about my dear husband, I believe I do right to say that he does not leave the ministry for the purpose you seem to suppose. He leaves rather for this reason, that he is unwilling to remain a teacher and a guide while his own mind is so unsettled ; in other words, he cannot teach that in which he has not undoubting faith. His many and pressing parochial duties have left him but little time for the consideration of those subjects of doubt, and he now wishes to resign, that he may take that time to study, that he feels the importance of the subject demands. And though I look forward to what will be the probable consequence of this course, I believe at present his mind is undecided. Having said this much with regard to Henry, I come now to speak of myself of whom I speak more decidedly. Let me then say plainly and without hesitation, that it is my intention next summer, God willing, to become a member of the Catholic Church, nor should I delay even that length of time, but for certain circumstances which you will readily understand, will prevent my leaving home this winter as will be necessary for me to do when I take the steps. My time not being occupied as my dear husband's has been, I have had time for much thought, and some reading according to my capacity, which has enabled me to come to a conclusion sooner than he. Need I say, my dearest Maria, that this determination is not made without consideration and many prayers and many tears. To endeavor to give you all my reasons would be in vain, for in the first place, they are'^too numerous for a letter, and besides with your present views it would be useless. Suffice it to say that two or three years since the qiicslion of authority first commenced disturbino- my mind, a queslion by the way which I know has oflen agitated your mind, my dear Maria. I have slriiggled against it, and while investigating the subject, have tried to view it favorably with reference to the Episcopal church. Although I resolved at the first, that feeling and affection should not govern me, still I have found it very hard to act up to this. With all the strong prejudices against the Catholic Church, ^vith which as a Protestant, I have been brought up, and with a strong and devoted attachment to the Episcopal Church in which I was baptized, confirmed and received the sacrament of the Lord's supper, and in which was all my delightful associations you may easily believe me when I say, I have found it hard to determine to leave her communion. And even now, I should rejoice, could I feel persuaded that I was doing my duty to remain where I cm. Eut I have earnestly prayed that God would enlighten my understanding and teach me my duty, and then enable me to do it, without reference to my own intentions, whatever sacrifice it might require. And I can only attribute it to His grace and mercy that I am able to look calmly and resolutely at what used to give me great pain and almost disgust. I know^ that this will give you and dear mother great pain, and that those whose love and respect I have so highly prized, will hereafter look at me with different feelings. I dread, I shrink from grieving you and my dear mother, and I sometimes almost fear that I shall offend her. But all those things may not move me. I dare not peril my soul for the dearest earthly consideration, nor would you have me. I dare not stay where I am, and I long to take a step which will put my mind more at rest. I have little more to say, save that I hope you will ever love me, as you have done, and that the delightful intercourse and feelings which have ever existed between us will not be disturbed by this event. I v/ould suggest that we do not converse about it. I am ready to hear whatever 3X)u may, any of you, have to say on the subject. Eut I think at present it would only excite us both unnecessarily to talk about it, and therefore it would be best to wuite about it. It is my earnest prayer that God will enable us all to know and to do our duty, and after this life we may "M.r.s. Hoyt ^vtis for four or live ycar.M"»r(-"^'ious to her death a most devoted Avorker in behalf of the little foundlings— weekly she spent an almost entire day at the Asylum making thousands of garments for the little ones. They benefitted also by her leisure moments at hom'j. her lingers working quicklv in their b?half, although never permitting charity to interfere with h?r household duties 3Irs. Hoyt being always a great sufferer her labor was all the more commendable. To US3 her own expression, she seemed to share in our dear Lord's crown of thorns. With all this suffering Mrs. Hoyt continued faithful to her labors until within one week of her death." (From Sister Irene, New York), Her dust, her sacred dust, r.s the Rev. Father Hoyt named it, lies near the earthly remains of her mother and two of her children. Tlie body of her venerable husband was deposited in a grave adjoining her own. They both loved St. Joseph, and had taken him for their chosen and life-long patron. " An Indian legend relates that about the beginning of the seventeenth century a Missionary Priest of the Order of St. Francis, accompanied by some Indians in two bark canoes, landed on an island, which some time after was named Isle La Mottc. The object of his journey was to visit scattered bands of hunters who were encamped along the eastern shore of Lake Champlain and its vicinity, at dillerent points in the valley of said lake. From Isle La Motte they steered for the mouth of the Missisquoi river, which they navigated up to the first falls, where the village of Swanton now stands. From that place they proceeded on foot for some miles to the base of a line of hills, thought to be those east of St. Albans. The next place they reached was an Indian camp on the bank of a river discovered by Champlain, and named by him tlie Lamoille. After some days the Indians of that place accompanied the party in canoes to the lake and along its shores to the mouth of the Winooski river, which they ascended as far as the first falls. Here they remained many days, during which time the Missionary visited the present site of Burlington, and held two missions there — one at a camp on the summit of a hill overlooking the valley of the Winooski as it approaches the lake ; and one near the lake shore. On their way back to Swanton, where they had left their own canoes, they lingered for some days on Grand Isle." — [Traces of an Lulian legend, in the Catholic World. To a Catholic of Vermont it is gratifying to know that the holy sacrifice of the Mass was offered so long ago on so many points of the State, and that at this present time there is a church standing near the spot, and it may be on the very place, which was sanctified by the offering of the holy sacrifice, at the hands of one of the saintly disciples of St. Francis. From the preceding legend it appears that two Indian camps, or settlements, existed then in Burlington, on the hill which forms the western bank of the Winooski, aud this hill we are pleased to name the Hill of St. Joseph. Was it somewhere about this spot that Fanny Allen was favored with an apparition of St, Joseph ? It may be so, for she lived about two years in Burlington, in the farm house of her father, Ethan Allen j and this house, quite isolated now, as it was then, is situated near the Winooski, which here, frequently overflows its banks. Be that as it will, it is certainly in this State that the fact related occurred ; and my readers will now understand thru it was quite appropriate to have a group representing the Holy Family placed over one of the altars of the Cathedral of Burlington. Our good Sister Allen of the Convent of the Hotel Dieu of St. Joseph, did certainly enter that religious house through the intervention of St. Joseph, and ice therefore should remember the mercies extended to her, and prepare to obtain also the proteclion of Holy Joseph for ourselves. We love, moreover, to record that St. Joseph has not been forgotten in Burlington. When in the year 1852 Rev. Joseph Quevillon started on our hill the building of a church for the Canadians of Winooski and Burlington, he placed his people under the patronage of St. Joseph, and gave to the edifice the name of the Church of St. JosepJt. When a fev/ years later, in 1854, the Sisters of Providence came to Burlington from Montreal to take charge of our orphans, they named the house the St Joseph's Orphan Asylum, and we can testify that in this humble building his protection was constantly invoked for the space of thirty years. The little orphans who, daily answering the Litany of St. Joseph by saying, pray for us, (and sometimes ;;«?/ for us) never were in want of their daily bread, though they were very numerous, and had no resources but the alms of our Catholics. If you go back from the old Orphan Asylum, towards old St. Joseph's Chiu-ch, you will notice a very tine statue of St. Joseph placed high under a cupola over the school house of the French Church ; for here in Vermont as well as in Galilee it is well that the young be protected by St. Joseph. During the month of March you will hear fervent prayers offered to St Joseph by the children on this hill, in the school rooms ; and in the Church by the whole congregation. Here, also, you will see banners, s::atues, societies of St. Joseph. St. Joseph is the patron of the dying, and here on the hill of St. Joseph we have him watching over the dead also ; for we have the Cemetery of Mount St. Joseph for the Cathedral, and the Cemetery of St. Joseph for the French C<inMdian congregations. Now if you look from the hill towards the lake, you will notice in the distance the new Orphan Asjdum, and if you chance to pass near by this orphanage you will read, in conspicuous letters, over the door, the dear name of our holy Patriarch, St. Joseph. But as we write these lines the congregation of old St. Joseph's Church are erecting a new St. JosepKs Church edifer, which can not but be seen by any one who approaches Burlington, be it from the west, by water, or from the south and cast, by land. The great dimensions of this building, and the pri- valions which the people cheerfully underiro to complete it, show to evidence how sincerely devoted all our people are to St. Joseph. On the Hill of St. Joseph devotion is not conlined to exterior mai-ks of veneration ; devotion here exists in the heart, and it is gratifying to remember how many young persons there are, who have left the Hill of St. Joseph to consecrate themselves to God in religious houses; some of them being now far awa.y from home and country. In the cemetery of Mount St. Joseph are buried the remains of our venerable Rev. William II. Hoyt, close to the remains of his wife and of two of their children. Adjoining these graves are those of Captain N. Tucker, Mrs. Deming, Gen. De Witt Clarke and wife, Mrs. LydiaMeech and Gustavus Austin and wife. By his examples and words Rev. Father Hoyt had more or less directly contributed to the conversion of those dear dead, as he named them. Of this spot it was that he wrote to his daughter : "I lono- to o-o north and see Burlington once more in its summer attire, which I have not seen since six years ago. The dear Cemetery, too, I long to visit when it will be clothed with its summer beauties, more fitting to the memory of our dear ones dead, than the snow and cold wintry winds which have prevailed there during all my visits." The two cemeteries on the hill of St. Joseph are as dear to thousands of our Catholics as they were to Father Hoyt, for there lieth the dust, the sacred dust, of thousands who were dear to us, and whom God has glorified because they loved and served Him on earth. But of all the spots on the hill of St. Joseph there is not one which excites so much interest as the new College of St. Joseph. God grant that it may continue and prosper, and that all those who will be educated there may be like St. Joseph, just in the presence of God and filled with a spirit of Apostolic zeal for the propagation of his Kingdom on earth ! CON CLUSION. Two thoughts have continually recurrc 1 to our mind whilst wTitino; our Catholic Memoirs. The lives of Rev. Father Hoyt, Fanny Allen, the Rev. Fathers Barb-r, and especially that of Sister Mary Augustm, remind us of the lives of the early martyrs. In the early days of Christianity to renounce the worship of idols and to become a disciple of Christ w\as to expose oneself to certain death ; but those courageous men and women knew that Jesus Christ is God, that He established only one Church, and that they were obliged to enter it under risk of losing their immortal soul. Now, the religion established by the Son of God is the same to-day as it was in the days cf the early christians, and men are as much bound to embrace it now as they were who lived In the days of the Apostles. Oh how sad it is to see so many men who voluntarily blind themselves, will not open their eyes to see the truth, or will make no effort to tind it ! And amongst Catholics how many there are who resist God's grace calling them to'a more perfect life ! Let these recall to mind the examplel of the admirable men and women whose lives w^e have sketched . Oh, wdiat great things these did do to please God, and how little it is that we do ! and yet their Gcd is our God, their crucified Saviour i.s our crucified Saviour I There nrj outside of the Catholic Church sincere persons who desire to be more intimately united to God on earth than they are, in following the doctrines and practice;3 of protestant churches. They have read in the gospel the svreet invitation of their God, "Come to me all ye who suffer .... I will not leave you orphans." That presence, ihat fruition of Jesus Chri^: is to be found only in the holy sacrament of the Catholic Church. Here only is the manna of the traveller in the desert ; here only is the bread of life, the bread which, if we eat, w^e shall abide with Christ, and Christ in us— (John vi.) We know of a chapel in whieli there was lately a protestant minister on his knees whilst the priest was giviug communion to some Catholics. He said some time after to a clergyman, " I wanted to go and receive with them. Would they have given it to me ?" The priest might have answered liini— " This is exclusively the bread of children : believe and be baptized, i^roxe yourself by going to confession, and then you shall be entitled to come and receive the bread of life " C 0 N G L URIO N. 151 As soon as Fanny Allen, Viri,nl Barber, and his wife, had known the gift of God, and received communion, they began to aspire to a perfect life, and forsook every thing in order to lead a life of purity, poverty and obedience. It was in daily receiving communion that Father Hoyt, during the life of his wife, found grace to fulfil every duty of his state. To holy communion he had recourse in days of joy and days of affliction, as a means also to obtain grace for the living and eternal rest for the souls of the departed, and in his old age he found strength in the Holy Eucharist to persevere in the severe life of a student, amongst young seminarians, resolved also to spend the balance of his days in preparing souls for communion in the confessional, and spending his days and parts of his nights at the foot of the altar. The sacred altars of the Catholic Church are the only places where the w^eary soul can fmd its rest. "How lovely are thy tabernacles O Lord of hosts ! My soul longeth and faintcth for the courts of the Lord. My heart and my flesh have rejoiced in the living God ! For the sparrow hath found herself a house, and the turtle a nest for herself where she may lay her young ones. Thy altars, O Lord of hosts. My King and my God." (Ps. 83.) God grant that all Catholics, by their love of the Holy Eucharist, may bring within the fold many of the sheep which are not of the flock of Jesus Christ. May all men so venerate on earth the mysteries of the body and blood of Christ, as to experience in heaven the glory of his redemption ! A NOTICE OF ITS IKTEEIOE DECORATIONS. For the benefit of those who attend the Cathedral in Burhngton, and of those who come to visit it, tlic following notices of its interior decorations have been written, with the hope that they will prove both instructive and edifying. Although these decorations are not yet complete, they show that the prevailing idea has been to make it the House of God and the Oate of Heaven, a source of glory to God and of blessings to man. THE CEILING. When you shall have entered the building by the front door, your attention will at once be drawn to the high ceiling. It is made entirely of wood, worked up in arches and arabesques highly illuminated. The eHect is very beautif id, especially at night, when the church is lighted up. It will remind you, dear reader, of God who made the Heavens and the earth, and has prepared for those who love Him a mansion more lovely than all the tabernacles of earth. These are of Vermont marble. It has been thought right to place in the house of God, as an homage to his Majesty, some stones of those precious deposits with which He has enriched our State. The columns were each of them given by the priest w^hose name is inscribed en it ; and are, as you perceive, a striking emblem of their own vocation. THE CHAXCEL. The part where the altar is built is the holiest of the building, corresponding to, but being more holy than, the Holy of Holies of old. It is separated by a railing from the body of the church. You should not enter it. The ceiling of the Chancel has been more richly decorated by gilt stars, monograms of the holy names of Jesus and M;iry, the Cross, the Crown, &c. According to Catholic usage, the great or Chancel Altar is consecrated to God under the name of the Patron Saint of the Church , and every thing in this part of the Cathedral relates to Mary, immaculate in her conception, the Patroness of the Diocese of Burlington. Over the chancel Arch you have the Lily with the Crown and Stars, symbols of her purity and glory ; on the scroll to each side, Hail full of Grace, (the ground of her dignhj,)— Blessed is the fruit of thy icomh : will remind you of Him who died on Calvary and is ofiered on the altars of the church, from the rising of the sun to the going down thereof. see it best from the right, or Epistle side. Mary, as yet a child, accompanied by her parents Joachim and Anna, presents and consecrates herself to God in His temple, at the hands of the High Priest. That consecration was early, entire and THE HIGH ALTAR Is the most important object in the Church, the edifice itself having been built to receive it. This altar was consecrated on the 8th day of December, lb67. In the top slab there have been deposited Relics of the Apostles, and many martyrs, virgins and confessors. It is made also of Vermont marble, and is beautiful though in an unfinished state. The Bronze Medallion in front represents the infant Jesus in the Crib, Mary and Joseph adoring, &c. The Tahe'rnade, with the Exposition on the Altar, are much admired as a work of art ; but are much more precious in the eyes of Catholics on account of the Blessed Sacn;ment which they are destined to contain. SIDE ALTAR TO THE LEFT. Under the Arch, fronting the door of the East Aisle, there is a Mortuary Altar. There Masses arc ofCered for tht? repose of the departed, for it is a Holt/ and wholesome thought to jyray for the dead, that they may be loosed from their sins. When you will come here to pray to God to give them eternal rest, you will no doubt notice the stained glass window above it in the east wall. It represents THE DEATH OF ST. JOSEPH. St. Joseph, the spouse of Mary, and foster father of Jesus Christ, called a just man in the Gospel, died at Nazareth, in his own small house, sanctilied by the presence of the Son of God. After a holy though hidden life, he died in the arms of Jesus and Mary. Angels hovering over his bed hold the scroll on which there is written Blessed are they who die in the Lord. The protection of St. Joseph is implored in order to obtain a happy death. In the trifoil part of this window you have the Blessed Virgin praying and obtaining relief for the suffering souls of Purgatory. The group of statues representing the holy family, placed behind the mortuary altar, was placed there as a memorial of the tableau of the Hotel-Dieu mentioned in the sketch of Fanny Allen's life, LAST SUPPER. The window has no need of being explained. Here you have Christ, who having lored His who were in the world, loved them vnto the end, and leaving tlicm the greatest pledge of His love, by the changing the bread into His body. You will find ample food for meditation by examining the expressions of the noble ligurcs of Christ, and the Apostles ; the traitor, at the lower part of the table, with the purse which contains his treasure; and also remark the words. Take yc and cat, this is my body. The window of the last supper has been placed quite appropriately in this part of the chancel, for this is the place of the chapel of the Blessed Sacrament on Holy Thursday. There is an altar of marble erected under that window in honor of St, Anne. St. Anne's name is very dear to Catholics in this part of the world, where we have experienced so often the effects of her compassion and power. The statue of the good saint above the altar is the gift of one of the ladies of the congregation. THE REREDOS OF THE GREAT ALTAR. It is customary to have behind the great altar a frame or screen containing an oil painting representing the patron saint of the Church, or a scene from his life. The reredos of the Cathedral is quite elaborate and is in itself an abridgement of the life of the Mother of God. In the lower part of the frame which rises to the ceiling, we have the four emblematiug figures on canvas, representing the purity, the faith, the charity, and the humility, of the holy Virgin. Three medallions above these figures represent (also on canvas) the Annunciation, the Coronation of the Blessed Virgin, and the same Immaculate Virgin, crushing the heads of the serpent. (Genes. III). In the upper part of the reredos we see in a richly ornamenled niche a statue of the Immaculate Conception, of exquisite workmanship. In order that you may well understand the beautiful idea of the artist, recall to mind the admirable prayer which we love to recite. It begins with the words. Six statues of angels of smaller size, projecting from the frame work, surround the image of the Immaculate ^Mother. Two of these placed immediately under the statue, seem to invite you to say with them : Salve regina. Hail ! Holy Queen. The four others projecting from each side of the niche continue the invocations, Mother of mercy, our life and sweetness, and our hope. ]SIary is the queen of angels, and those holy spirits venerate her who is full of grace, and implore her intercession for men. CATnEDRAL OF THE IMMACULATE CONCEPTIOX. 157 Kolhing need be stiid about the throne of the Bishop, except that its sight should cause you to return thanks to God ; that throne beini,'occupied by one who "was placed by God to rule the church of God, which he hath purchased with His own blood. (Act. xx. 28). The very large and beautiful statue of the Sacred Heart of our Lord, lately put near the altar of St. Anne, is a gift of a friend of the congregation who desires to sec the devotion of the Sacred Heart of our Saviour increase amongst us. The index of the right hand pointing to the heart reminds us of the words, "Behold this heart which have loved men so much." '' My son give me thy heart." STAINED .GLASS WINDOWS. The stained glass windows of the Cathedral of Burlington are very remarkable, not only by their excellence as works of art, but chiefly because they were so selected and arranged as to form a continuous and complete course of religious instruction. Watered by the blood of the holy ^Martyrs ; Instructed by the holy Doctors ; Announced by the holy Confessors ; Edified by the holy virgins and women. WINDOWS OF WEST TRANSEPT. In these three windows one subject is repre.sented of whieh the conception is admirable — Christ has expired on the Cross — His eternal Father accepts the sacrifice ; through Him the penitent receives pardon, and the sinner punishment — the merits of His sacrifice are applied to our souls through the sacraments of the church. In the foliated pannels of the large window, angels hold up the instruments of the Passion, the Crown of Thorns, the Pillar, Lance, Hammer, Nails, &c. Below, God, surrounded with angels ; with out stretched arms, and beholding His Son, seems to accept the victim which has voluntarily died on the Cross for the redemption of men. Angels look down at the scene on Calvary, wondering as it were, at the extent of God's love towards man ; tw^o of them holding on a scroll the w^ords of the expiring Saviour — In Thy hands. Oh! Lord, I commend my spirit. The dark ground, in the rear of the Cross, refers to the darkness which covered the earth. Mary to the right stands yet by the Cross, but in deep agony mingled with resignation ; John, the beloved disciple, and apostle of Love, stands to the left. As to the blinded figure, it represents the Synagogue which in its blindness would not receive Jesus Christ as the Messiah,— and whose standard has been broken ; its authority is gone. In the figure opposite we have a beautiful emblem of the Church, — her standard is the Cross oi Him who delivered himself up tor her. Her garments are beautiful ; her features are youthful and noble ; she wears the Diadem of Authority, and her brow is encircled with the nimbus or halo of holiness. (See Eph. V. 25 et seq). To her was given the mission of sanctifying mankind, and she holds up in her left hand the cup of our Saviour's merits, as the only source of sanctification to men . The skull and bones on the ground, close to the cross, remind us of Death, which entered the world by Adam's disobedience ; but Christ has destroyed it by His own death, and given us a pledge of a glorious resurrection. The fiery serpent curled around the Cross, whose head has been crushed, reminds us that Christ by Death has destroyed him who had the empire of Deeith, that is to say, the Devil. Let ns next examine the window to the ri^dit of this larger window. It represents the imiitcnt Rohher on the Cross. In the trifoil of this window the guardian angel looks down with complacency on this soul committed to his care, about to leave the body, in sentiments of resignation, hope and repentance. On the top of his cross another angel assists him in his agony. A young babe, reposing calmly in the arm of a third angel, represents the soul of the Robber carried into heaven, and received there by angels. As to the dying man, himself, after invoking the mercv of Christ, whose innocence and power he confessed, he continues beholding from his own cross, the Saviour who promised him a share in His kingdom. On the other side of the higher window, you have the death of the tricked Robber. His angel in the trifoil covers his face in his hand for sorrow ; for the irickcd Robber he blasphemed him, notwithstanding the proofs he had witnessed of his power and dignity ; hence a Devil stays bv him on the cross, ready to devour his soul and inciting him to persevere impenitent. Yet he continues to look at Jesus, now dead, but with a marked expression of anguish, obduracy and despair. A few moments more his sinful soul shall have left his body. A demon will now seize that soul (represented by a baby) and notwithstanding its fruitless resistance, hand it to another wicked spirit who drags it into and punishing obdurate sinners, at the moment of their death. In order to understand the whole of this tableau, you should now inspect the lower pannels of the three windows together, beginning from your left to the right, not forgetting that every thing here relates to Jesus Christ crucified. He died to sanctify men ; but the merits of His death are to be applied to cur souls, and the Church has received this office. She holds the cup of her Saviour's merits, and pours them on our souls to cleanse, strengthen and beautify thein. This she does by administering her Sacrammis : and these channels of santification convey grace to her children through all the different stages of their their hands upon them and they received the Holy Ghost. As this child grows in age, his temptations become stronger, he is exposed to fall into sin. He receives Communion, (third pannel) which upjtcs him to Jesus Christ, who beconies the food of his soul, What will become of our soul after sin lias been committed, if no means are to be found to remove it ? (fourth pannel). If ice confess our sins God is faithful wJio icill remit them to vs. Confession, however, should be made with a penitent heart, and to the successors of those to whom Christ said — whose sins you shall f org ire, they are forgiven them. Christ has not fori^-ct the dying. Extreme Unction prepares the soul for eternit}^, (liflli pannel). Tiring ia the Priests of the Church, and let tliemitray oecr him, anointing him with oil in the name of the Tjynl. See Jas. v : 14 and 15. The sacrament of Ordination (sixth pannel) conveys ..grace and power to the recipient ; and the church is in this way provided with ministers to guide and sanctify her children. Marriage (seventh pannel) is a great Sacrament in Christ and in the Church. Through the worthy reception of this rite, the merits of Jesus Christ being applied to their souls, the husband and wife receive grace to love one another, and bring up their children in the fear of God. To lovers of art, we would say to visit these three windows toward evening— to all, we would say, when you examine the scene before you, remember that God loved you ; that Christ thought of ycni when he died ; that for you He established the Church, and appointed it to administer the life-giving Sacraments ; linally, that He will reward or punish your soul as soon as it will leave your body, as He rewarded the penitent and punished the impenitent sinner. Such are the scenes represented in the three windows of this Transept. The chief figure here is that of Christ, the judge, pronouncing the sentence. Every thing else in the tableau relates to Him. In the foliated part of the large window, Almighty God {the Ancient of Days) is adored by angels, and is represented with emblems of His power and eternity. He has given the judgment to His Son, who came on earth to teach men and to die for them. In his hands, we see the print of the nails. To his right an angel holds up the Cross, the emblem of Salvation, at whose sight all the tribes of the earth shall mourn. To His left another angel holds the scale (symbol of judgment), and a book on which there is written,— 77/ ^i/ that hare done good shall come forth unto the Resurrection of Life, hut they that have done evil, unto the Resurrection of Judgment. {John 5 : SO). This group is represented as floating in the clouds. Another group below represents the dead risen or rising, whilst in the back ground, buildings are seen burning, and tumbling to the ground, to remind us of the last conflagration. Nothing can be more beautiful than this resurrection of the Dead, for they seem to be conscious of their fate. Hope, love, shame or despair are written in their actions and features. The elect turn towards Christ, their eyes in joy, and vrould fly to Him ; the reprobate would fain sink back in the earth. The Judgment itself is not represented, but you have the sentence. The smaller window, to the right of Christ, contains, written on a scroll, the w^ords of Christ to the just— Come, ye blessed of my Father, dr., and you see them go up in body and soul to meet Christ in the air ; their body being now glorified, incorruptible, they shall go to life everlasting in the company of their guardian angels,— they seem already to realize the fullness of their reward. The smaller window, to the left of Christ, shows written on a .scroll the dreadful sentence— Depart fro7n me you cursed into everlasting j/;.^_its execution is also reprcEcnted. Faithful angels with flaming swords banish the wicked from the face of Christ. Their costly dress, and high position does not save the reprobate ; serpents are curled round their body, they are seized and led towards hell by Demons who will lay on torments in their fury. In the flames which escape from the abyss you see the figures of two other reprobates who lost Heaven and are already burning. You should now examine the seven lower pannels of those three windows. To feed the hungry ; give drink to the thirsty ; clothe the naked ; harbor the harborless ; visit the sick and prisoners ; and to bury the dead,— such are the works of mercy. They shall have a particular reward at the last dtiy. provided they have not neglected to fulfil CLERESTORY WINDOWS. Nineteen windows light up the ceiling of the nave. Being very high up and of small size, they have been filled with stained glass containing simply an emblem or memorial, — the series commences near the organ gallery at the right when you go in through the front door Hence, in order to see them, you should go to the opposite side, or to the west aisle. They all refer to circumstances of the Passion of our Lord Jesus Christ, or the establishment and destiny of the Church. Under each window you see a text written on the wall ; read it before you look at the emblem, and you will at once understand what it represents. By example— the first emblem is the Cup of Agony, and the text under reads, — Father, if thou ipill, remove this cup from me. COLUMBIA UNIVERSITY LIBRARIES This book is due on the date indicated below, or at the expiration of a definite period after the date of borrov/ing, as provided by the library rules or by special arrangement with the Librarian in charge.	88,156	common-pile/pre_1929_books_filtered	catholicmemoirso00dego	public_library	public_library_1929_dolma-0013.json.gz:1181	https://archive.org/download/catholicmemoirso00dego/catholicmemoirso00dego_djvu.txt
9aNPy4-hlajPIZD0	Anthropology	12 Chapter 12: Future Humans The Long Now Foundation “Human existence is about to get much better, much worse, or both.” —Robby Berman “As long as you have a ridiculously long view of things, things are getting better.” —Robert Sapolsky “How can we recognise the shackles that tradition has laid upon us? For when we recognise them, we are also able to break them.”—Franz Boas “I am not here for myself, rather for the future, all the kids that will come.” —Nemonte Nenquimo, president of the Waorani Council of Pastaza In previous chapters, we talked about FOXP2, the only gene that we know of that influences language (though others are now emerging). All animals have this gene, but they have different versions compared to humans. Neanderthals as we know have the same version of FOXP2 as modern humans and so our version is fairly ancient. To find out more about this intriguing gene, geneticists used transgenic mice to test the in vivo functions of the human gene in another species. What does that mean? They put a human FOXP2 gene in a fertilized mouse egg to see what would happen. It turned out the songs that the transgenic mice produced were different than their wild counterparts. Yes, male mice have courtship songs, and the human FOXP2 mice created songs with rhythmic distortions. Sadly, these little rodent Jimi Hendrixes* were labeled “abnormal” by the scientists, a typical response to artists ahead of their time. In this chapter, we will consider the future of humans. We ask the question, in light of genetic editing and other technological advances, who and what will be considered a person in the future. *Don’t know Jimi Hendrix? The Idea of a Human We have discussed in this class what it means to be human—how we are different from and similar to other species. We have considered whether other species have language, or whether it is uniquely human. We have looked at how categories like “subsistence” and “race” have been used to justify treating people like non-humans or sub-humans. We have examined non-human primates and their similarities and differences to humans and discussed whether other species (or even rivers or trees) should have rights like humans do. We have looked at the ambiguity of humanness in the paleoanthropological record and considered whether Neanderthals and other hominins were human, and if so, why. And finally, we considered whether ancient human remains like Anzick Boy and Kennewick Man are people, and should be treated as such, or whether they are objects to be studied. But the very definition of what it means to be human is changing. Historian Michael Bess explains: “But what we’re on the verge of doing with bio-engineering technologies like CRISPR is going to be so qualitatively different and more powerful that I think it’s going to force us to reassess who we are and what it means to be human” (Illing 2018). Some have even suggested we are becoming less human-like and more god-like. Visual anthropologist Edmund Carpenter (1976:1) likened contemporary humans to angels, “a spirit freed from flesh.” He explains, “The moment we pick up a phone, we are nowhere in space, everywhere in spirit…That is the Neo-Platonic definition of God: a being whose center is everywhere, whose borders are nowhere.” More recently, Historian Yuval Noah Harari (2018) describes our species, not as Homo sapiens, Homo spiritualis, or Homo fictus, but as Homo Deus—god humans—given our unprecedented control over nature, over our biology, and our ability to create different kinds of intelligence. Taking the Long View In our busy and complicated lives, we often take the short view, thinking only about next week or, if we are really organized, we might have a five-year plan. The next generation or the next 100 or 1,000 years is typically not foremost in our minds. Thinking ahead, however, is essential for our own personal success and the future of the planet. The value of looking ahead is captured in the much-cited Iroquois principle of “seven-generation thinking” where one considers the effect of actions of generations living 140 or so years from now and acts accordingly. We are connected to the people of the past and are living in a world affected by their decisions and actions. The Long Now Foundation was created to promote long-term thinking on the scale of centuries and a sense of long-term responsibility. The Clock of the Long Now, designed to last 10,000 years and chime every century, exemplifies this extreme long view. In this chapter, we take the long view and consider the future of humans and our lasting impacts on the planet. We have discussed the Anthropocene—the age of humans—in a previous chapter. We have transformed the planet through domestication, deforestation, urbanization, ocean acidification, changing biodiversity, and changes to our atmosphere. Even places noted for their isolation and endemic species—unspoiled lands—have huge numbers of invasive species as a result of humans. The remote Galápagos Islands in Ecuador, famously visited by Charles Darwin in 1835, have an estimated 1,700 invasive species and about 20,000 human inhabitants. Given the current trends, we can ask: What will the future of the biosphere look like? How will our species have changed hundreds or even thousands of years from now? What new stories are yet to be told? Hacking Humans In this age of genetic research, we are on the threshold of something entirely new—directly adjusting the human genome. Gene editing has improved in recent years with a method called CRISPR/Cas-9. The technique delivers gene-editing components which target a section of DNA and snip out the mutation, which is then replaced with the desired version. Potentially, the method could be used to edit DNA t prevent diseases like sickle cell anemia or cystic fibrosis which are caused by a single SNP (Saey 2017). Currently, the Food and Drug Administration (FDA) is barred from clinical trials of editing embryos and the National Institutes of Health cannot fund such research. Scientists have used the technique to edit genes in a human embryo to repair a genetic mutation, but the embryos were not permitted to develop (Belleck 2017). One fear is that editing embryos—human genetic engineering—runs the risk of designer babies or “CRISPR babies” that are smarter, prettier, or more athletic. China has already begun using CRISPR on terminal cancer patients. American trials are awaiting approval from the FDA. The head of those trials, Carl June, thinks of the CRISPR trials and research as a kind of biomedical Sputnik, spurring technological competition between the U.S. and China. A second concern is how CRISPR will be regulated. Who will have access to it? Will some be able to profit from it? The United States military is funding genetic research into gene editing, causing alarm over potential military uses (Nelson 2017). CRISPR has implications beyond humans as well. It is theoretically possible, for instance, to wipe out mosquitoes that carry malaria or other disease-carrying vermin. Biochemist and CRISPR co-creator Jennifer Doudna (2017) discusses the potential dangers of releasing edited animals into the wild, including upsetting the balance of an ecosystem or unintentionally wiping out a species. There is also the talk of “de-extinction” of animals—bringing back some version of extinct species using CRISPR. Doudna points out that traits are created by the interaction of many genes, not to mention environmental conditions. And so is not clear whether de-extinction could be a reality. Ethical and ecological questions would also have to be addressed in light of de-extinction. Perhaps most disturbing is the threat of “super-bugs” that are engineered to cause a global pandemic (Bresler and Bakerlee 2018). Using gene-editing to produce artificial SNPs, bypasses the process of natural selection. While many of today’s diseases are typically zoonotic, gene editing tools like CRISPR could bypass the processes of diseases leaping from one organism to another, but rather targeting a specific one instead by design. Whether caused by accidental release or intentional terrorism, the results of engineered pandemics are equally terrifying. With the threat of super-bugs, there is a call for developing infrastructure to develop vaccines to keep apace of the bio-hacked super-bug threat. A New Intelligence In addition to bio-hacking changing the human landscape, other kinds of technology like artificial intelligence (AI) are blurring the lines between computers and humans’ minds. Computers are outpacing humans at tasks that were once considered the exclusive domain of the human brain. IBM’s Deep Blue program beat Grandmaster Garry Kasparov at chess, and in 2016 AlphaGo beat the best in the world at the complex game of Go (Koch 2016). AlphaGo continuously plays itself, steadily improving its skill, a process called “machine learning.” Learning is foundational to human and even animal culture. Machine learning is quite different from culture since it does not involve communication and coophumann between individuals. Philosopher Nick Bostrom thinks that the potential for artificial intelligence exceeds that of humans, what Bostrom calls “super-intelligence.” That is, according to Bostrom, computers have the potential to be more “sapien”, better thinkers, than humans. Bostrom says, “Think about it. Machine intelligence is the last invention that humanity will ever need to make. The machines will then be better at inventing than we are” (Bostrom 2015). Nick Bostrom compares the potential of artificial intelligence and humans to the very different pathways of humans and gorillas. One primate is on the verge of extinction, while the other has become a dominant species responsible for that annihilation (Khatchadourian 2017). What will happen to humans in the face of increasingly sophisticated artificial intelligence? The future, he suggests, would be shaped by the preferences of this AI, and consequently, we need to consider how to ensure that super-intelligence is aligned with human values. Who gets to decide what those values are? Computer algorithms, a series of rules designed to accomplish a task, are becoming increasingly important to our daily lives. Today, the top investment managers don’t look for fresh business models to invest in, as depicted on Shark Tank, rather they rely on computer algorithms to make important investment decisions (McGee 2016). Even our social lives have been infiltrated by algorithms. We’ve come a long way from arranged marriages—or have we? In the U.S., we don’t typically entrust our village elders or parents to find a suitable mate, but many put trust in computer algorithms on sites like Tinder and Match.com. Some call centers are now using computer sensing to connect a caller with the most effective customer service person. This is accomplished by analyzing linguistic input like the caller’s tone of voice and choice of words, to match mood and personality with an agent. Even art is not outside the realm of computer algorithms, with computer-generated music based on the style of masters like Mozart or Beethoven (Adams 2010). Computers are beginning to do things that were formerly squarely in the realm of human culture—finding mates, making art, and using language. Artificial Intelligence (AI) and machine learning will impact the future job market, with experts estimating that as many as 47% of all jobs will become automated in the next 25 years (Ratner 2017). Other estimates are not as dire, with an estimated 14 percent of jobs lost. Other concerns are that automation will not remove jobs entirely, but will result in lower pay. Jobs like grocery clerk, travel agent, and banker are already mostly automated. The comparison between humans and robots is daunting—hospital pharmacy robots make zero errors (Manjoo 2011). Driverless cars are being tested on roads, currently with a human backup, with the idea of creating safer transit (Thrun 2010). While autonomous cars do not get tired or experience road rage, other ethical questions arise. How would driverless cars evaluate a situation and determine whether to crash itself or strike a pedestrian or how might it decide which pedestrian to strike given a dire scenario? These choices would require programming as a part of its algorithm and serious ethical deliberation. The Inhabitat by Nissan-Autonomous-Drive CC BY-NC-ND In the not-too-distant past, nearly all Americans were agriculturalists. With the onset of the Industrial Revolution, employment shifted to industry with a smaller number in service sectors. Today, as industry declines, more and more people work providing some kind of service—in health, education, and computer programming. The Department of Labor Statistics lists 102 million people in service jobs as of 2016. Will automation and AI cause another shift in the economy that eliminates the need for most service jobs? If so, what will be left for people to do, and how will they make a living? How much power will those who own algorithms have over those who have none? Google’s subsidiary DeepMind has created a research group, DeepMind Ethics, and Society, dedicated to studying the economic and social effects of artificial intelligence (Vincent 2017). What Makes a Person? The very idea of what is human, who has personhood, has changed over time and has been defined culturally. We saw that Ota Benga was considered less than human when he was housed alongside monkeys and apes in the Bronx Zoo. Enslaved African men in the U.S. were not considered “persons” before they obtained citizenry and the right to vote with the 14th and 15th amendments. Ponca Chief Standing Bear argued during the 1879 Standing Bear vs. Crook trial had to argue that he was a human. He stated, “That hand is not the color of yours, but if I pierce it, I shall feel pain. If you pierce your hand, you too will feel pain. The blood that will flow from mine will be the same color as yours. I am a man.” Standing Bear won his case, which granted rights of personhood and the right of habeas corpus (have to show cause for authorities to detain you) to native peoples. As late as 1971 the U.S. Supreme Court in Reed v. Reed agreed that women were “persons” and the 14th Amendment (“nor shall any state deprive any person of life, liberty, or property, without due process of law”) applies to women. Some animal species like dolphins and chimps have been represented in court with regard to personhood and rights, along with corporations, rivers, and other non-human entities. Germany has granted some rights to animals in its constitution, especially with regard to experimentation for cosmetics and pharmaceuticals (Connelly 2002). Ecuador’s Constitution addresses the rights of the environment directly, stating that it has “the right to integral respect for its existence and for the maintenance and regeneration of its life cycles, structure, functions, and evolutionary processes.” It is easy to see the connection here with animism, endowing natural phenomena with human-like qualities, a spirit, soul, or agency. Or, indeed, the reverse, that humans are a part of nature. These recent efforts to grant animals, rivers, and “Mother Earth” with human-like rights lies in stark contrast to viewing the earth as a resource only. A blurring of what constitutes a person also appears in art. A photograph of Erica, dubbed the most realistic human robot, was shortlisted for the National Portrait Gallery’s Taylor Wessing prize, even though technically the portrait is supposed to be of a living person (Warburton 2017). The Future of the Past Kennewick Man also known as The Ancient One is one of the earliest skeletons found in the Americas and dates to ca. 9,000 years ago, at the end of the Pleistocene and the beginning of the Holocene. Kennewick Man, like so many other remarkable finds, was found accidentally. Two college students found the skeletal remains while wading in the Columbia River in Washington on Army Corps of Engineers land (federal property) during a boat race. Thinking it was a forensic case, they called in the authorities. At first, it was thought to be an early European explorer given the skull morphology. The radiocarbon date, however, sparked a controversy that is still raging today. The problem is who owns or who has rights to Kennewick Man’s remains? Is Kennewick Man a person or a thing? Some scientists argued that Kennewick man is a thing to be studied. Some tribal Nations, on the other hand, argued that Kennewick Man is a person, who required a proper burial. The legislation called NAGPRA or Native American Graves Protection and Repatriation Act of 1990 stipulates that human remains and other culturally important items found on federal lands should be repatriated or returned to tribes that can demonstrate cultural affiliation. Most repatriations are non-controversial, and there is a clear link between ancient remains and modern people. With Kennewick Man, the link from past to present was so distant that scientists who wanted to study the remains questioned whether he should be repatriated and reburied. In addition, some suggested that Kennewick Man’s cranial morphology resembled Europeans more than Native Americans. You can see how this debate had similarities to the Folsom site debate, where Hrlicka did not think Native Americans had been in the New World for very long. In 2015, a genetic analysis of Kennewick Man—comparing his SNPs to worldwide populations—revealed he was more similar to Native Americans (both North and South) than any other modern population. Kennewick Man’s mtDNA haplogroup (X2A) is found almost exclusively in Native Americans. (Haplogroup X, from which X2A is derived is found in the Americas, Europe, the Middle East, and Africa). This case also illustrates how attempts to place Kennewick Man into a category based on morphology were flawed as racial categories are also often flawed. In 2017, Kennewick Man was reburied in an undisclosed location on the Columbia Plateau by Native tribes. The discussion over whether bodies are objects or people also applies to the exhibition of modern people, like the Bodies exhibit in which humans bodies are preserved and displayed in terms of different systems (digestive, skeletal, muscular). The bodies, which are Chinese in origin, have no clear provenance and may come from executed prisoners. Some have called for a ban on the exhibit and burial of the bodies. Food for a Growing Planet We have learned about foraging, horticulture, pastoralism, and agriculture, along with the concept of intensification. Today there are around 7 billion people on the planet and we expect to hit 9 billion by 2050. How will we feed everyone? Technically, there is enough food to feed the world’s population, but the food is often wasted, fed to animals, converted to biofuel, or is not affordable by the people that need it most. Food prices are a major component of the problem. Prices have skyrocketed as a result of climate change, increasing oil prices, ethanol fuel, the rise of the middle class, and demand for better foods in places like China. People in poorer countries spend nearly 70 percent of their income on food alone. Given these factors, there is concern that a global food crisis will emerge by 2050. Scientists estimate that as much as 50 percent more food will be required by that time to feed the world. Geographer Evan Fraser lays out four different actions that can be taken to avoid a global food crisis. First, technology could help the impending global food crisis by providing Africa with materials for modern farming—seeds, fertilizers, and equipment— to maximize its food potential. This effort would have to play out at the local level with farmers and scientists working together, necessitating a deep understanding of local practices and cultures. Secondly, small farms around urban areas would provide a buffer in case world markets fail. Third, food aid organizations must have stockpiles of food and a plan of distribution when food shortages arise. Finally, Fraser argues that governmental regulation is needed to promote and ensure sustainable farming. Sara Menker, CEO of Gro Intelligence, suggests that the crisis could happen much sooner than 2050. She predicts that by 2027 there will be a deficit of 214 trillion calories, an outcome of catastrophic proportions. She explains that some countries like the United States produce more food than they consume. South American countries like Brazil have flipped from being food importers to producers, at the loss of rainforest. Other regions, like China and Africa, are importers of food and will be hit hardest by a global food crisis. Menker argues that the commercialization of agriculture—intensification—in Africa could tip the balance back, making Africa a net producer that can sustain itself and provide food to food importers. Making New Stories We have looked at how humans are “swimming” in culture. Our own culture can be hard to see because we take it for granted or assume it is normal. Some of our most salient realities are created by people—everything from money to laws to some of our most cherished values. Even those who are not religious very often have deep-seated values that are sacred to them. Those values are in turn backed up by symbols and stories. Nonetheless, our shared web of meaning, our sacred values, and the symbols and stories that accompany the can change in an instant. The Soviet Union can disappear with the signing of the Belavezha Accords, the Defense of Marriage Act can be overturned overnight, and once-illegal drugs like marijuana can suddenly become legal. Even the ideals and values of our parents can seem quaint to us. The value system and worldview of our great-great-great grandparents, who may have lived through the American Civil War or the Mexican Revolution, would likely seem foreign to us. And technology is changing so fast, that people worry that our values system cannot keep pace with the changes. Historian Michael Bess cautions, “We need to sit down with ourselves and say, “As I look at my daily life, as I look at the past year, as I look at the past five years, what are the aspects of my life that have been the most rewarding and enriching? When have I been happiest? What are the things that have made me flourish?” If we ask these questions in a thoughtful, explicit way, then we can say more definitely what these technologies are adding to the human experience and, more importantly, what they’re subtracting from the human experience.” (Illing 2018) As we experience these new changes in technology and what it means to be human, people, especially young people, have much power in deciding the shape of a culture’s values and the stories and symbols that support those values. The actions of your generation will shape the course of the future as we enter the Anthropocene. If we do this with eyes both on the past and the future, we stand to make better choices for our species and the natural environment.	4,877	common-pile/pressbooks_filtered	https://pressbooks.pub/newmexico9/chapter/chapter-12-future-humans-mytext-cnm/	pressbooks	pressbooks-0000.json.gz:74101	https://pressbooks.pub/newmexico9/chapter/chapter-12-future-humans-mytext-cnm/
PRi3gZxZhY7lFMZv	British Columbia in a Global Context	8. Physical Geography of British Columbia Geology The term geology comes from the Greek words “ge” (“earth”) and “logia,” meaning the study of and discourse involving the solid Earth, including the rocks of which it is composed, and the processes by which those rocks change. Geology can also refer generally to the study of the solid features of any celestial body (such as the Moon or Mars). Geology gives insight into the history of the Earth by providing the primary evidence for plate tectonics, the evolutionary history of life and past climates. In British Columbia, geology is important for economic development associated with mineral and hydrocarbon (oil and natural gas) exploration and harvest. Geology is valuable to the public for predicting and understanding natural hazards, the remediation of environmental problems, and for providing insights into past climate change. Geology also plays a role in geotechnical engineering and is a major academic discipline. Formation of the mountains is a dramatic evolving process associated with geology and geomorphology. Geomorphology is the study of the process that creates and transforms the surface of the Earth. Geomorphology seeks to understand landform history and dynamics, and predicts changes through a combination of field observation, physical experiment and numerical modelling (geomorphometry). The Earth is stratified, meaning that it has several layers. In the very centre lies the solid core, which is surrounded by a liquid core. Next is the mantle, asthenosphere, the lithosphere and finally the crust at the top. Each of these layers is made up of different mineral composition. Several types of rocks are found throughout the crust. Plate tectonics theory suggests that the Earth’s lithosphere is made up of seven large plates and several small ones. Rising convection plumes from the asthenosphere can force the plates to move. The plate edges are where most volcanic and earthquake activity take place. These activities move minerals and materials. Below is a map of the geologic era rock found in British Columbia. Plate tectonics is a significant field of study in BC since as there are so many fault lines (see Figure 8.8). Faults are where plates meet. When two plates jam together, the edges often fracture and collapse forming mountain ranges in a process called orogeny. Another significant process to the formation of the rugged terrain found in BC is isostasy, which is the process of the surface of the Earth loading and unloading. For example, the Rocky Mountains are made up of sedimentary rock which erodes relatively quickly. A process is known as isostatic rebound, occurs which is the gradual rising of land elevations as it springs back after thousands of years of being crushed under the weight of continental glaciers. A complex system of fault lines can be found in British Columbia. In Figure 8.8, all known and inferred fault lines are present with the major fault lines in bold. The five fault lines featured in the figure are the Pinchi Fault in Central BC, the Fraser River Fault, the Columbia River Fault, the Rocky Mountain Fault and the San Juan Fault. Subduction View a short video on subduction from the National Oceanographic and Atmospheric Administration at http://oceanexplorer.noaa.gov/edu/learning/player/lesson04.htmWhile the San Juan Fault may look small on this map, an earthquake along this fault could have significant ramifications for the residents of southwestern BC. The San Juan Fault separates the oceanic Juan de Fuca Plate from the heavier and denser North American continental plate through subduction. Subduction occurs when two plates collide and one is denser or heavier than the other, forcing the heavier one downward and under the other. Subduction can cause trenches in the ocean floor, which will warm and may cause the plate to melt, producing magma and flow into volcanic eruptions at the surface resulting in new rocks. These processes also move and transfer minerals and sediment from different layers of the Earth and deposit them in different places. Understanding how and where these pieces of sediment have come from and moved to help geologists unlock the mystery of the formation of surface terrain. For example, the Pinchi Fault is a significant fault system in central BC that extends 450 kilometres and separates dominating oceanic sedimentary bedrock in the region from the volcanic rocks in the eastern portion of the province (Plouffe, 2001). The resulting terrain consists of a plate pushing up instead of down against the edge of the neighbouring plate, which can cause significant earthquakes. Attributions - Figure 8.6 Earth-cutaway-schematic-english Licensed under Public domain via Wikimedia Commons. - Figure 8.7 Geologic era of rock in British Columbia. Created by Hilda Anggraeni with data provided by Digital Geology Maps BC Ministry of Geology and Mines (http://www.empr.gov.bc.ca/Mining/Geoscience/PublicationsCatalogue/DigitalGeologyMaps/Pages/default.aspx) - Figure 8.8 British Columbia fault lines. Created by Hilda Anggraeni with data provided by Digital Geology Maps BC Ministry of Geology and Mines (http://www.empr.gov.bc.ca/Mining/Geoscience/PublicationsCatalogue/DigitalGeologyMaps/Pages/default.aspx)	1,042	common-pile/pressbooks_filtered	https://opentextbc.ca/geography/chapter/9-4-geology/	pressbooks	pressbooks-0000.json.gz:23964	https://opentextbc.ca/geography/chapter/9-4-geology/
CsQhchddkmCdLbjA	Child and Adolescent Psychology	3 Theories of Development What is a theory? Students sometimes feel intimidated by theory; even the phrase, “Now we are going to look at some theories…” is met with blank stares and other indications that the audience is now lost. But theories are valuable tools for understanding human behavior; in fact they are proposed explanations for the “how” and “whys” of development. Theories can help explain these and other occurrences. Developmental theories offer explanations about how we develop, why we change over time, and the kinds of influences that impact development. A theory guides and helps us interpret research findings as well. It provides the researcher with a blueprint or model to be used to help piece together various studies. Think of theories as guidelines much like directions that come with an appliance or other object that required assembly. The instructions can help one piece together smaller parts more easily than if trial and error are used. Theories can be developed using induction in which a number of single cases are observed and after patterns or similarities are noted, the theorist develops ideas based on these examples. Established theories are then tested through research; however, not all theories are equally suited to scientific investigation. Some theories are difficult to test but are still useful in stimulating debate or providing concepts that have practical application. Keep in mind that theories are not facts; they are guidelines for investigation and practice, and they gain credibility through research that fails to disprove them. (3) Psychodynamic Theory We begin with the often controversial figure, Sigmund Freud. Freud has been a very influential figure in the area of development; his view of development and psychopathology dominated the field of psychiatry until the growth of behaviorism in the 1950s. Freud’s assumption that personality forms during the first few years of life and that the ways in which parents or other caregivers interact with children have a long-lasting impact on children’s emotional states have guided parents, educators, clinicians, and policy-makers for many years. We have only recently begun to recognize that early childhood experiences do not always result in certain personality traits or emotional states. There is a growing body of literature addressing resiliency in children who come from harsh backgrounds and yet develop without damaging emotional scars (O’Grady and Metz, 1987). Freud has stimulated an enormous amount of research and generated many ideas. Agreeing with Freud’s theory in its entirety is hardly necessary for appreciating the contribution he has made to the field of development. (4) Sigmund Freud: Background Sigmund Freud (1856–1939) was a Viennese M. D. who was trained in neurology and asked to work with patients suffering from hysteria, a conditioned marked by uncontrollable emotional outbursts, fears and anxiety that had puzzled physicians for centuries. He was also asked to work with women who suffered from physical symptoms and forms of paralysis, which had no organic causes. During that time, many people believed that certain individuals were genetically inferior and thus more susceptible to mental illness. Women were thought to be genetically inferior and thus prone to illnesses such as hysteria (which had previously been attributed to a detached womb which was traveling around in the body). However, after World War I, many soldiers came home with problems similar to hysteria. This called into questions the idea of genetic inferiority as a cause of mental illness. Freud began working with patients suffering from hysteria and discovered that when they began to talk about some of their life experiences, particularly those that took place in early childhood, their symptoms disappeared. This led him to suggest the first purely psychological explanation for physical problems and mental illness. What he proposed was that unconscious motives and desires, fears and anxieties drive our actions. When upsetting memories or thoughts begin to find their way into our consciousness, we develop defenses to shield us from these painful realities. Freud emphasized the importance of early childhood experiences in shaping our personality and behavior. In our natural state, we are biological beings. We are driven primarily by instincts. During childhood, however, we begin to become social beings as we learn how to manage our instincts and transform them into socially acceptable behaviors. The type of parenting the child receives has a very powerful impact on the child’s personality development. We will explore this idea further in our discussion of psychosexual development. (4) Freud’s Theories of Development This section introduces Freud’s theories of development. These include: - Theory of the Mind - Theory of the Self - Psychosexual Stages (1) Theory of the Mind Freud believed that most of our mental processes, motivations and desires are outside of our awareness. Our consciousness, that of which we are aware, represents only the tip of the iceberg that comprises our mental state. The preconscious represents that which can easily be called into the conscious mind. During development, our motivations and desires are gradually pushed into the unconscious because raw desires are often unacceptable in society. Theory of the Self As adults, our personality or self consists of three main parts: - Id - Ego - Superego The id is the part of the self with which we are born. It consists of the biologically-driven self and includes our instincts and drives. It is the part of us that wants immediate gratification. It operates under the pleasure principle , which means that the criteria for determining whether something is good or bad is whether it feels good or bad. An infant is all id. The ego is the part of the self that develops as we learn that there are limits on what is acceptable to do and that often we must wait to have our needs satisfied. This part of the self is realistic and reasonable. It knows how to make compromises. It operates under the reality principle or the recognition that sometimes need gratification must be postponed for practical reasons. It acts as a mediator between the id and the superego and is viewed as the healthiest part of the self. Here is an abbreviated listing of defense mechanisms suggested by Freud. If the ego is strong, the individual is realistic and accepting of reality and remains more logical, objective, and reasonable. Building ego strength is a major goal of psychoanalysis (Freudian psychotherapy). So for Freud, having a big ego is a good thing because it does not refer to being arrogant, it refers to being able to accept reality. Defense mechanisms emerge to help a person distort reality so that the truth is less painful. Defense mechanisms include: - Repression : To push the painful thoughts out of consciousness (in other words, think about something else). - Denial : Not accepting the truth or lying to the self. Thoughts such as “it won’t happen to me” or “you’re not leaving” or “I don’t have a problem with alcohol” are examples. - Regression : Refers to “going back in time” when the world felt like a safer place, perhaps reverting to one’s childhood. This is less common than the first two defense mechanisms. - Sublimation : Involves transforming unacceptable urges into more socially acceptable behaviors. For example, a teenager who experiences strong sexual urges uses exercise to redirect those urges into more socially acceptable behavior. - Displacement : Involves taking out frustrations on to a safer target. A person who is angry with a supervisor may take out their frustration at others when driving home or at a spouse upon arrival. - Projection : Defense mechanism in which a person attributes their unacceptable thoughts onto others. If someone is frightened, for example, he or she accuses someone else of being afraid. - Reaction formation: Defense mechanism in which a person outwardly opposes something they inwardly desire, but that they find unacceptable. An example of this might be homophobia or a strong hatred and fear of homosexuality. The superego is the part of the self that develops as we learn the rules, standards, and values of society. This part of the self takes into account the moral guidelines that are a part of our culture. It is a rule-governed part of the self that operates under a sense of guilt (guilt is a social emotion-it is a feeling that others think less of you or believe you to be wrong). If a person violates the superego, he or she feels guilty. The superego is useful but can be too strong; in this case, a person might feel overly anxious and guilty about circumstances over which they had no control. Such a person may experience high levels of stress and inhibition that keeps them from living well. The id is inborn, but the ego and superego develop during the course of our early interactions with others. These interactions occur against a backdrop of learning to resolve early biological and social challenges and play a key role in our personality development. Psychosexual Stages Freud’s psychosexual stages of development are presented below. At any of these stages, the child might become “stuck” or fixated if a caregiver either overly indulges or neglects the child’s needs. A fixated adult will continue to try and resolve this later in life. For about the first year of life, the infant is in the oral stage of psychosexual development. The infant meets needs primarily through oral gratification. Babies explore the world through the mouth and find comfort and stimulation as well. Psychologically, the infant is all id. The infant seeks immediate gratification of needs such as comfort, warmth, food, and stimulation. If the caregiver meets oral needs consistently, the child will move away from this stage and progress further. However, if the caregiver is inconsistent or neglectful, the person may stay stuck in the oral stage. As an adult, the person might not feel good unless involved in some oral activity such as eating, drinking, smoking, nail biting, or compulsive talking. These actions bring comfort and security when the person feels insecure, afraid, or bored. During the anal stage , which coincides with toddlerhood or mobility and potty training, the child is taught that some urges must be contained and some actions postponed. There are rules about certain functions and when and where they are to be carried out. The child is learning a sense of self-control. The ego is being developed. If the caregiver is extremely controlling about potty training (stands over the child waiting for the smallest indication that the child might need to go to the potty and immediately scoops the child up and places him on the potty chair, for example), the child may grow up fearing losing control. He may become fixated in this stage or “anal retentive,” that is, fearful of letting go. Such a person might be extremely neat and clean, organized, reliable, and controlling of others. If the caregiver neglects to teach the child to control urges, he may grow up to be “anal expulsive” or an adult who is messy, irresponsible, and disorganized. The phallic stage occurs during the preschool years (ages 3–5) when the child has a new biological challenge to face. Freud believed that the child becomes sexually attracted to his or her opposite sexed parent. - Boys experience the “Oedipal Complex” in which they become sexually attracted to their mothers but realize that Father is in the way. He is much more powerful. For a while, the boy fears that if he pursues his mother, father may castrate him (castration anxiety). So rather than risking losing his penis, he gives up his affections for his mother and instead learns to become more like his father, imitating his actions and mannerisms and thereby learns the role of males in his society. From this experience, the boy learns a sense of masculinity. He also learns what society thinks he should do and experiences guilt if he does not comply. In this way, the superego develops. If he does not resolve this successfully, he may become a “phallic male” or a man who constantly tries to prove his masculinity (about which he is insecure) by seducing women and beating up men. - Girls experience the “Electra Complex” in which she develops an attraction for her father but realizes that she cannot compete with mother and so gives up that affection and learns to become more like her mother. This is not without some regret, however. But she must resign herself to the fact that she is female and will just have to learn her inferior role in society as a female. However, if she does not resolve this conflict successfully, she may have a weak sense of femininity and grow up to be a “castrating female” who tries to compete with men in the workplace or in other areas of life. During middle childhood (6–11), the child enters the latent stage focusing his or her attention outside the family and toward friendships. The biological drives are temporarily quieted (latent) and the child can direct attention to a larger world of friends. If the child is able to make friends, he or she will gain a sense of confidence. If not, the child may continue to be a loner or shy away from others, even as an adult. The final stage of psychosexual development is referred to as the genital stage . From adolescence throughout adulthood a person is preoccupied with sex and reproduction. The adolescent experiences rising hormone levels and the sex drive and hunger drives become very strong. Ideally, the adolescent will rely on the ego to help think logically through these urges without taking actions that might be damaging. An adolescent might learn to redirect his or her sexual urges into safer activity, such as running. Quieting the id with the superego can lead to feeling overly self-conscious and guilty about these urges. Hopefully, it is the ego that is strengthened during this stage and the adolescent uses reason to manage urges. Strengths and Weaknesses of Freud’s Theory Freud’s theory has been heavily criticized for several reasons. One is that it is very difficult to test scientifically. How can parenting in infancy be traced to personality in adulthood? Are there other variables that might better explain development? The theory is also considered to be sexist in suggesting that women who do not accept an inferior position in society are somehow psychologically flawed. Freud focuses on the darker side of human nature and suggests that much of what determines our actions is unknown to us. So why do we study Freud? As mentioned above, despite the criticisms, Freud’s assumptions about the importance of early childhood experiences in shaping our psychological selves have found their way into child development, education, and parenting practices. Freud’s theory has heuristic value in providing a framework to elaborate and modify subsequent theories of development. Many later theories, particularly behaviorism and humanism, were challenges to Freud’s views. (4) Psychosocial Theory Now, let’s turn to a less controversial psychodynamic theorist, the father of developmental psychology, Erik Erikson. Erik Erikson (1902–1994) was a student of Freud’s and expanded on his theory of psychosexual development by emphasizing the importance of culture in parenting practices and motivations and adding three stages of adult development (Erikson, 1950; 1968). He believed that we are aware of what motivates us throughout life and the ego has greater importance in guiding our actions than does the id. We make conscious choices in life and these choices focus on meeting certain social and cultural needs rather than purely biological ones. Humans are motivated, for instance, by the need to feel that the world is a trustworthy place, that we are capable individuals, that we can make a contribution to society, and that we have lived a meaningful life. These are all psychosocial problems. Erikson divided the life span into eight stages. In each stage, we have a major psychosocial task to accomplish or crisis to overcome. Erikson believed that our personality continues to take shape throughout our life span as we face these challenges in living. We will discuss each of these stages in length as we explore each period of the life span, but here is a brief overview. The Ego Rules Psychosocial Stages - Trust vs. mistrust (0–1): infant must have basic needs met in a consistent way in order to feel that the world is a trustworthy place - Autonomy vs. shame and doubt (1–2): mobile toddlers have newfound freedom they like to exercise and by being allowed to do so, they learn some basic independence - Initiative vs. Guilt (3–5): preschoolers like to initiate activities and emphasize doing things “all by myself” - Industry vs. inferiority (6–11): school aged children focus on accomplishments and begin making comparisons between themselves and their classmates - Identity vs. role confusion (adolescence): teenagers are trying to gain a sense of identity as they experiment with various roles, beliefs, and ideas - Intimacy vs. Isolation (young adulthood): in our 20s and 30s we are making some of our first long-term commitments in intimate relationships - Generativity vs. stagnation (middle adulthood): 40s through the early 60s we focus on being productive at work and home and are motivated by wanting to feel that we’ve made a contribution to society - Integrity vs. Despair (late adulthood): we look back on our lives and hope to like what we see; that we have lived well and have a sense of integrity because we lived according to our beliefs. 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wIqAjnrNEYzbOIus	Professional Web Accessibility Auditing Made Easy	Introduction Why Learn About Web Accessibility Auditing? Lulu’s Story Begins Lulu’s Lollipops is a thriving business, with 52 employees, based out of Hamilton, Ontario, Canada. Lulu’s business is primarily web-based and has been operating for ten years selling lollipops of various shapes, sizes, colours, and flavours. A representative of a charitable organization has approached Lulu about placing a large order for lollipops that would be part of an upcoming fundraising campaign. As part of the charity’s mandate, the representative has asked about the accessibility of Lulu’s website to ensure that staff from different chapters of the charity can easily place orders. Lulu realizes that she has never really considered the accessibility of her website and, based on a recommendation from a friend, Lulu decides to enrol herself and a number of her team members in Web Accessibility Auditing Made Easy. As a business owner, Lulu understands that there are some provincial guidelines she should consider as she works to accommodate the needs of her potential client (the charitable organization), but she still wonders why it makes sense to modify the website that has already served her company so well for over 10 years. Lulu and her team need to think about three important things: “curb cuts,” the business case, and the AODA. Read on to learn more about these compelling factors related to investment in web accessibility. View the Lulu’s Lollipops website. Curb Cuts Think about “curb cuts,” a great example of what is often thought of as universal design. Curb cuts were originally added to streets to accommodate those in wheelchairs so they could get from the road up onto a sidewalk and vice versa. But curb cuts are helpful for many people — not just those in wheelchairs. A person pushing a baby stroller can now easily get to the sidewalk. A person riding a bike can get more easily onto the sidewalk where the bike lockups are located. An elderly person who may have difficulty stepping up on a curb or who may be using a walker now has a smooth gradient and can walk onto the sidewalk rather than climb onto it. Curb cuts were designed to help those in wheelchairs but have come to benefit many. From a web accessibility perspective, most of the accessibility features you might add to a website will have that so-called “curb cut effect.” For example, the text description one might include with an image to make the image’s meaning accessible to a person who is blind also makes it possible for search engines to index the image and make it searchable. It allows a person on a slow Internet connection to turn images off and still get the same information. Or, it allows a person using a text-based browser, on a cell phone for instance, to access the same information as those using a typical visual browser. Virtually every such feature that might be put in place in web content to accommodate people with disabilities will improve access and usability for everyone else. The Business Case for Web Accessibility Karl Groves wrote an interesting series of articles in 2011 and 2012 that looked at the reality of business arguments for web accessibility. He points out that any argument needs to answer affirmatively at least one of the following questions: - Will it make us money? - Will it save us money? - Will it reduce risk? He outlines a range of potential arguments for accessibility: - Improved search engine optimization: Customers will be able to find your site more easily because search engines can index it more effectively. - Improved usability: Customers will have a more satisfying experience and thus spend more on or return more often to your site. - Reduced website costs: Developing to standard reduces bugs and interoperability issues, reducing development costs and problems integrating with other systems. - People with disabilities have buying power: They won’t spend if they have difficulty accessing your site; they will go to the competition that does place importance on accessibility. - Reduced resource utilization: Building to standard reduces the use of resources. - Support for low bandwidth: If your site takes too long to load, people will go elsewhere. - Social responsibility: Customers will come if they see you doing good for the world and you think of people with disabilities as full citizens. - Support for aging populations: Aging populations also have money to spend and will come to your site over the less accessible, less usable competition. - Reduced legal risk: You may be sued if you prevent equal access for citizens/customers or discriminate against people with disabilities. What accessibility really boils down to is “quality of work,” as Groves states. So, in approaching web accessibility, one may be better off not thinking so much in terms of reducing the risk of being sued or losing customers because your site takes too long to load, but rather that the work you do is quality work and the website you present to your potential customers is a quality website. Video: The Business Case for Accessibility Readings and References: If you’d like to learn more about business cases, here are a few references: - Developing a Web Accessibility Business Case for Your Organization (W3C) - Chasing the Web Accessibility Business Case (Karl Groves, 2012) part 1 - Chasing the Web Accessibility Business Case (Karl Groves, 2012) part 2 - Chasing the Web Accessibility Business Case (Karl Groves, 2012) conclusion - 2 Seconds as the New Threshold of Acceptability for eCommerce Web Page Response Times (Akamai, 2009) - Releasing Constraints: The Impacts of Increased Accessibility on Ontario’s Economy (Summary) - Releasing Constraints: Projecting the Economic Impacts of Increased Accessibility in Ontario (Full Report) [PDF] AODA Background Video: AODA Background For those in Ontario, Canada, we’ll provide occasional references to the Accessibility for Ontarians with Disabilities Act (AODA). If you’re from outside Ontario, you might compare the AODA’s web accessibility requirements with those in your local area. They will be similar in many cases, likely based on the W3C WCAG 2.0 Guidelines. The goal in Ontario is for all obligated organizations to meet the Level AA accessibility requirements of WCAG 2.0 by 2021, which, ultimately, is the goal of most international jurisdictions. The AODA provided the motivation to create this resource, based on the MOOC course of the same name. All businesses and organizations in Ontario with more than 50 employees (and all public sector organizations) are now required by law to make their websites accessible to people with disabilities (currently at WCAG 2.0 Level A). Many businesses still don’t know what needs to be done in order to comply with the new rules. This resource hopes to fill some of that need. The AODA has its roots in the Ontario Human Rights Code, introduced in 1990. It essentially made it illegal to discriminate based on disability (among other forms of discrimination). The development of the AODA began in earnest in 1994 with the emergence of the Ontarians with Disabilities Act (ODA). Its aim was to legislate the removal and prevention of barriers that inhibit people with disabilities from participating as full members of society, improving access to employment, goods and services, and facilities. The act was secured as law in 2001. With the election of a new government in 2003, the movement that brought us the ODA sought to strengthen the legislation. The Accessibility Standards Advisory Council was established, and the AODA was passed as law in 2005, and in July of 2011 the Integrated Accessibility Standards Regulation (IASR) brought together the five standards of the AODA, covering Information and Communication, Employment, Transportation, and Design of Public Spaces, in addition to the original Customer Service standard. The AODA sets out to make Ontario fully accessible by 2025, with an incremental roll-out of accessibility requirements over a period of 20 years. These requirements span a whole range of accessibility considerations — from physical spaces to customer service, the Web, and much more. Our focus here is on access to the Web. The timeline set out in the AODA requires government and large organizations to remove all barriers in web content between 2012 and 2021. The timeline for these requirements is outlined in the table below. Any new or significantly updated information posted to the Web must comply with the given level of accessibility by the given date. This includes both Internet and intranet sites. Any content developed prior to January 1, 2012 is exempt. \| Level A \| Level AA \| \| \|---\|---\|---\| \| Government \| January 1, 2012 (except live captions and audio description) \| January 1, 2016 (except live captions and audio description), January 1, 2020 (including live captions and audio description) \| \| Designated Organizations* \| Beginning January 1, 2014, new websites and significantly refreshed websites must meet Level A (except live captions and audio description) \| January 1, 2021 (except live captions and audio description) \| \| *Designated organizations means every municipality and every person or organization as outlined in the Public Service of Ontario Act 2006 Reg. 146/10, or private companies or organizations with 50 or more employees, in Ontario. \| For more about the AODA you can review the following references: Readings and References:	2,000	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/pwaa/chapter/lulus-story-begins/	pressbooks	pressbooks-0000.json.gz:25242	https://pressbooks.library.torontomu.ca/pwaa/chapter/lulus-story-begins/
9CV4IuDC0QNumkuq	2.2: You Need My Credentials to be a Writers	2.2: You Need My Credentials to be a Writers - - Last updated - Save as PDF - Cheryl E. Ball & Drew M. Loewe ed. - West Virginia University via Digital Publishing Institute and West Virginia University Libraries Author: Ronald Clark Brooks, Montclair State University Recently, I launched a public writing project to help people free themselves from writer’s block, or to at least free themselves from writer’s block for long enough that they could get some part of their own life stories written down. I particularly wanted to reach out to people who normally would not think of themselves as writers. Having considered most of the lessons of the process movement to be commonplace, I didn’t anticipate resistance to this project from the people I would meet, but on our first trip out I encountered a young man who very much considered himself a writer, and he told me outright that he found the project offensive. “Not everyone can write,” he said, and as he did so, the small group of people who had gathered around my booth started to disperse. What is it about writing that generates this attitude, often held passionately, that some people are writers and others are not? Is it the romantic ideal of innate genius? The belief that one has to be initiated in a given way to join a special club called writers? Is it something unique to the craft of writing and the anxieties it provokes? I have never heard of a professional baseball player, for example, telling a community baseball league that they should get off the field or that they’re a menace to the sport, but I have heard professional writers complain about there being too many people claiming to be writers. Is this an anxiety one sees from the practitioners of all underappreciated arts? Regardless of the answer to these questions, the idea that one has to be a credentialed writer in order to write is definitely a bad idea about writing, one that is pervasive in the general public and oftentimes fostered by writing teachers themselves. When talking to the young man at my booth, I realized that as a composition teacher, and especially as a trainer of teachers, I have encountered some version of the belief that one has to be credentialed in order to call oneself a writer for most of my professional life. Writing teachers should be credentialed (see Seth Kahn’s chapter), and in no way am I suggesting that these credentials are not important, but the kind of credentials that one gets in order to speak authoritatively about a field—whether that field is literature, film, cultural studies, creative writing, linguistics, or even the often now widely divergent fields of composition, rhetoric, and literacy studies—those need to be set apart from the beliefs that one must have in order to teach writing well. The most important belief that a writing teacher can have about writing is, as Peter Elbow (a well-known teacher of writing) put it, that everyone can write. And at the heart of that belief is the assumption that everyone’s experience and perspective is already worth writing about as soon they arrive in the classroom. To expand that belief beyond the classroom, we should generally believe that everyone’s experience and perspective is already worth writing about as soon as they arrive at the page or screen. If this belief is essential for teachers of writing, it is even more so for the writers themselves. At some level, when we sit down to write we must believe it can be done, regardless of our previous experiences, or nothing gets written. This is true for beginners, but it is equally true for experienced writers because every new writing situation brings on new challenges and, as many of us have discovered, one often has to learn to write all over again with each new project. At the same time, believing that one already knows how to write can be as much of a barrier to writing as believing that one can’t. Believing that everyone already knows how to write, however, is very different than believing everyone can write. Believing that everyone already knows how or should know how to write is a different bad idea (see Elizabeth Wardle’s chapter), and it is one that often leads to the production of five paragraph themes and disembodied, formulaic, general writing. Believing that everyone can write is simply starting with the idea that even though writing is complex, sometimes difficult, infinitely varied and variable, and dependent on rhetorical context, everyone is able to start somewhere in the process, and only from that ground can one unlock the potential to do it well. What is key, then, is to create a space where a writer can develop a more positive, empowered approach to the actual complexity that is writing. Peter Elbow began his career with the book Writing Without Teachers, and it might be that this more optimistic ground is more easily fostered outside the classroom, as the culture of assessment that schooling creates constantly wants to reintroduce the bad idea that you need credentials to be a writer. This is not to say that classes can’t hold on to the belief that everyone can write, but these kinds of classrooms require vigilance in order to reinforce optimistic attitudes about writing. Despite how difficult it is to do so, maintaining this vigilance has proven to be effective. In Ways of Thinking, Ways of Teaching , George Hillocks has shown us that optimism is the one factor that continually makes a positive difference in the outcomes of writing classes. If you find yourself in a writing course (or still remember a writing course) that has not fostered a positive outlook toward writing, it is entirely possible to create this environment yourself by surrounding yourself with supportive writers. Supportive does not mean they will tell you everything you write is great (that’s not what everyone can write means). Supportive means that they will hold you accountable to getting writing done and to help you continually improve your writing. That’s the beauty of it being a bad idea that you need credentials to be a writer. There is absolutely nothing stopping you from getting started right now. Further Reading For a longer exploration of the idea that Everyone Can Write and for ways of thinking about assessment based on this philosophy, see Peter Elbow’s book of the same title. For qualitative proof of the effectiveness of optimism and the writing process, see George Hillocks’s Ways of Thinking, Ways of Teaching . Because most process theorists share Elbow’s optimism about everyone’s potential to perform, it is worth studying the works of Ken Macrorie, Sondra Perl, Donald Murray, Wendy Bishop, and many others in order to know the best ways to foster your own supportive writing community. For even more specific information about how to create workshops beyond the confines of writing classrooms, see Pat Belanoff and Elbow’s Being a Writer: A Community of Writers Revisited. More importantly, look for local writers’ clubs and readings and community groups in your area. One possible way to find these is to sign up for and take part in National Novel Writing Month, Academic Writing Month, and Digital Writing Month. Many have found success by letting their writing communities develop from there. Keywords credentials, empowerment, growth, optimism, process movement, support, writing community Author Bio Ronald Clark Brooks is an associate professor and chair of the writing studies department at Montclair State University in Montclair, NJ. One of his primary interests is helping students learn to think of themselves as writers.	1,654	common-pile/libretexts_filtered	https://human.libretexts.org/Courses/Solano_Community_College/Bad_Ideas_About_Writing/02%3A_Bad_Ideas_About_Who_Good_Writers_are_.../2.02%3A_You_Need_My_Credentials_to_be_a_Writers	libretexts	libretexts-0000.json.gz:48818	https://human.libretexts.org/Courses/Solano_Community_College/Bad_Ideas_About_Writing/02%3A_Bad_Ideas_About_Who_Good_Writers_are_.../2.02%3A_You_Need_My_Credentials_to_be_a_Writers
LoXH6L7XA5U5Kc2w	The MLCKRB (Master List Code Key and Rule Book): An English Grammar & Style Handbook	F2: Double Negatives F2: Double Negatives: Do not use double negatives in sentences. See the following: http://www.warrencountyschools.org/userfiles/1593/Grammar/Double%20Negative%20Worksheet.pdf She does not want no marshmallows on her sweet potatoes. (Incorrect) She does not want any marshmallows on her sweet potatoes. (Correct) Beware of negative contractions causing a double negative. The isn’t a time for us to have no proper lunch with this schedule. (Incorrect) There isn’t a time for us to have a proper lunch with this schedule. (Correct) Beware of words like “hardly,” “barely” and “scarcely,” which understood as negative, causing double negatives. There were hardly no people at my presentation last night. (Incorrect) There were hardly any people at my presentation last night. (Correct) It was freezing, and he barely had no clothes to wear. (Incorrect) It was freezing, and he barely had any clothes to wear. (Correct)	179	common-pile/pressbooks_filtered	https://open.maricopa.edu/milkherb/chapter/f2-double-negatives/	pressbooks	pressbooks-0000.json.gz:11985	https://open.maricopa.edu/milkherb/chapter/f2-double-negatives/
lHVqR2iA4PlI4FOt	12.9: Essay Type - Literary Response	12.9: Essay Type - Literary Response The Response Essay The response essay is likely the most informal type of literary analysis essay students will encounter in a literature course. This essay simply asks the student to read the assigned text(s) and respond to said text(s). There are several purposes in writing such an essay. This kind of essay: - helps students better understand the reading through informal analysis - enables students to practice close-reading in a low-stakes, informal, and more comfortable way - prepares students for writing a more formal essay by recording their initial impressions of a text "Fernando Pessoa" by Jennifer Fred Merchán , 2006. CC BY-SA 2.0 Usually, the requirements for such an essay are more open-ended than what is expected on more formal essay assignments. For example, students are often allowed to use first-person "I" and colloquial (that is, spoken rather than academic) language. A thesis statement and formal organization are also usually not required. What is always required is a willingness to ask questions and engage with the text. The following are some questions students might respond to when writing a response essay: - First impressions: When reading the title and first lines, what impression did you get from the text? How did this impression change as you read the rest of the story or poem? What might the title indicate about the story or poem? - Characters: What kind of character is the main character of the story or poem? Are they likable? Trustworthy? Why? Which character do you like or relate to the most, and why? Which character do you dislike the most, and why? What kinds of characters ( dynamic, round, flat, static ) are featured in this story? - Tone: How would you describe the tone of the story? What words, phrases, images, or snippets of dialogue indicate this tone? - Figurative language: What figurative language or literary devices do you notice? Why do you think certain images appear? What kinds of patterns of language do you notice, and what significance might these patterns or literary devices have on the story or poem? In addition to these basic literary analysis questions, some helpful tips for writing this kind of essay: - Take notes as you read. Use highlighters to mark quotations or passages that jump out at you, along with post-it notes or page clips to mark those pages so you can find them again when writing the essay. Don't be afraid to write notes in the margins of the book. If you must sell back the book to the bookstore, or don't want to mark the book for other reasons, you can use post-it notes to write your responses. Essentially, effective note-taking is like having a conversation with the text. - Keep a document or journal open to record your ideas as you read. For example, refer to the image at the top of this page. This way, you can begin responding to the text as you read it, making efficient use of your time. You can then simply develop your reading notes in the essay. - Cite passages to support your analyses. Like in an argumentative or persuasive essay, be ready to drop quotations or paraphrase into the essay to support your analysis and show those reading your essay examples of what you are talking about. Be ready to provide page or line numbers to cite the source. For example, if you say Hamlet (the main character of Hamlet by William Shakespeare) comes across as whiny and egotistical, be prepared to quote or paraphrase the play and point readers to the act, scene, and line numbers which show your point. Example Student Response Essay Prompt \| Length requirement: \| 750 words minimum (no maximum, but please keep it under 5 pages if possible) \| \|---\|---\| \| Essay type: \| Response \| \| Number of sources required: \| One: the primary text you are analyzing. Use MLA citations and formatting. \| Objective By the end of this assignment, students will be able to engage with a work of literature through analysis and response. They will be able to define and locate examples of at least three basic literary devices within a single literary text. Audience: instructor & classmates Purpose: practice analyzing literature in a less formal environment Content: literary analysis & response, practice for the upcoming literary analysis essay Directions Students will choose one work of literature to analyze (that is, pick apart, zooming in, and looking closely at the literary devices and narrative elements of the story). Students may choose any of the stories we have read so far in class. As you read the story, respond to anything interesting in the text you notice. - Focus on one story - Identify & analyze at least three literary devices such as character, plot, setting, metaphor, and so forth - Use either objective third-person or first-person “I” - Present tense verbs, informal tone - Quote & paraphrase the text using MLA Works Cited + In-Text citation - Do not to bring in any secondary sources yet: this should be your personal observations and analysis of the text. Avoid using Shmoop, Cliffnotes, or any other plot summary websites. These will tarnish your reading process. I am interested in YOUR thoughts, not Shmoop’s - Avoid plot summary, unless used briefly to contextualize analysis. I know what happens in the stories. This is NOT a “summarize the story in your own words” exercise, but a “what patterns or interesting devices did you notice? What stuck out to you? Why do you think the author made the choices they did? In what ways does the story’s form reflect its content?” exercise.	1,231	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Literature_and_Literacy/Literacy_and_Critical_Thinking/Writing_and_Critical_Thinking_Through_Literature_(Ringo_and_Kashyap)/12%3A_Writing_About_Literature/12.09%3A_Essay_Type_-_Literary_Response	libretexts	libretexts-0000.json.gz:41520	https://human.libretexts.org/Bookshelves/Literature_and_Literacy/Literacy_and_Critical_Thinking/Writing_and_Critical_Thinking_Through_Literature_(Ringo_and_Kashyap)/12%3A_Writing_About_Literature/12.09%3A_Essay_Type_-_Literary_Response
FnrLDwiXNtz7aQBR	Regulations governing the recognition of breeds and purebred animals / U.S. Department of Agriculture, Bureau of Animal Industry	Office of the Secretary. Under authority of paragraph 1506 of the act of Congress approved September 21, 1922, entitled "An act to provide revenue, to regulate commerce with foreign countries, to encourage the industries of the United States, and for other purposes'' (42 Stat., 858, 923) ,* the following regulations are issued governing the recognition of breeds and purebred animals imported into the United States for breeding purposes. For purposes of identification these regulations are designated as B. A. I. Order 293 and supersede all previous regulations on the same subject. They shall become and be effective on and after May 26, 1925. Section 1. Bureau of Animal Industry to issue certificates. — The Bureau of Animal Industry of the Department of Agriculture is hereby authorized to issue certificates of pure breeding under the provisions of this order. procedure: Paragraph 1. Application for certificates. — An application for certificates shall be made to the Bureau of Animal Industry on forms furnished or approved by the department, showing the number of animals imported, the breed and sex, the port of entry into the United States, customs entry number, the name of vessel or carrier by which shipped, and the date of arrival. This application may be signed by either the owner, the importer, or the agent, stating the name and address (in the United States) of the owner of the animal or animals. (A. H. Form 105 — "Application for certificates" will be furnished upon request.) Paragraph 2. Certificates of pedigree. — Certificates of pedigree for such animals, issued by the custodian of one of the books ol record given in Regulation 2, section 4, of this order, shall be furnished to the Bureau of Animal Industry. Paragraph 8. Affidavit of identity. — A duly acknowledged affidavit from the owner, agent, or importer that the animals so imported are the identical animals described in the certificates of pedigree must be furnished. (A. H. Form 283— " Affidavit of identity" will be furnished upon request.) Paragraph 4- Vendors' certificates. — Complete transfer of ownership must be shown from the breeder to the importer either on the pedigree certificate, certificate of transfer, or vendor's certificate. If ownership is not indicated either on pedigree certificate, or by certificate of transfer, a vendor's certificate from the seller or his agent shall be furnished to the Bureau of Animal Industry with the application, giving the breed, sex, name, and registry number of each animal sold to the importer, the date of sale, the place of purchase, and the name and address (in the United States) of the purchaser. Vendors' certificates furnished by the custodians of foreign books of record containing the above information may be used; otherwise, the form of vendor's certificate furnished or approved by this department must be used. (A. H. Form 106 — " Vendor's certificate" will be furnished upon request.) Section 3. Applications will be given consideration in the order in which they are received. When the application and accompanying papers are satisfactory, certificates to that effect will be issued and forwarded to the collector of customs at the port of entry and the pedigree certificates returned to the importer or his agent. However, the certificates of pure breeding of the Bureau of Animal Industry will not be issued until the descriptions of the animals, taken by an inspector of the Bureau of Animal Industry at the port of entry, are received in Washington. All papers for animals which do not meet the requirements of this order will be retained or returned, at the discretion of the department. Section 4. Eligibility of animals. — Where the provisions of this order have been otherwise complied with, animals will be certified as purebred which have been fully registered in good faith in one of the books of record for one of the recognized breeds given in Regulation 2, section 4, of this order, except those which have been registered on inspection. Section 1. Application for recognition. — Before an additional breed to those shown in section 4 of this regulation shall be added to this order the custodian of its book of record shall submit to the department a complete set of the published volumes of such book of record to date of making application, together with all rules and forms in force on said date affecting the registration of animals in said book of record. The department will consider the case on its merits and use such information as may be available to determine whether the breed is a recognized breed and whether the animals registered in the book of record are purebred. culture, Washington, D. C, except as mentioned below. Section 3. Books of record required. — Custodians of books of record for recognized breeds shall forward volumes of their books of record as soon as published, addressed to the Chief of the Bureau of Animal Industry, in care of the United States Dispatch Agent, 2 Rector Street, New York, N. Y., U. S. A. Section 4. Recognized breeds. — The following breeds of domestic animals are recognized. Opposite will be found the names of the foreign books of record for these breeds, with the names and addresses of their custodians. secretary, Wiveliscombe, Somerset, England. Galloway Cattle Society of Great Britain and Ireland, James Carlyle, secretary, Monraive, Middlebie, Lockerbie, Dumfriesshire, Scotland. Leeuwarden, Holland. Vereeniging het Nederlandsche Rundvee-Stamboek, Louis Jarman, secretary, 's-Gravenhage, Surinamestraat, No. 24, Holland. Royal Jersey Agricultural and Horticultural Society, H. G. Shepard, secretary, 3 Mulcaster Street, St. Helier, Island of Jersey. English Jersey Cattle Society, T. W. Hammond and L. J. Craufurd, secretaries, 19 Bloomsbury Square, London, W. C. 1, England. English Kerry and Dexter Cattle Society, T. W. Hammond and L. J. Craufurd, secretaries, 19 Bloomsbury Square, London, W. C. 1, England. Road, Ipswich, England. Shorthorn Society of the United Kingdom of Great Britain and Ireland, V. H. Seymour, secretary, 12 Hanover Square, London, W. 1, England. Square, London, W. 1, England. Kerry Hill (Wales) Sheep Breeders' Association and Flock Book Society, Morris, Marshall and Poole, secretaries, Newtown, Montgomeryshire, England. Oxford, England. Shropshire Sheep Breeders' Association and Flock Book Society, Alfred Mansell & Co., secretaries, College Hill, Shrewsbury, England. England. Wensleydale Longwool Sheep Breeders' Association, G. Goland Robinson, secretary, Underley Farm, Kirkby Longdale, Westmoreland, England. Studbook. Societe" Royale "Le Cheval de Trait Beige," Chevalier Hynderick de Theulegoet, secretary, 20 Rue Royale, Brussels, Belgium. Clydesdale Horse Society of the United Kingdom of Great Britain and Ireland, Archibald MacNeilage, secretary, 93 Hope Street, Glasgow, Scotland. secretary, Knighton, Radnorshire, Wales. 1 Provided that no animal or animals registered in the Australian or in the French Thoroughbred studbooks shall be certified as purebred unless such animal or animals trace in all crosses to animals which are proved to the satisfaction of the department to be of the Thoroughbred breed. editor, Moreby Park, York, England. National Coursing Club, Horace A. Groom, keeper of the Greyhound Stud Book, 11, Haymarket, London, S. W. 1, England. for each dog. Paragraph 2. Recognized breeds and books of record in Canada. — The Canadian National Records are recognized for the following breeds: Provided, That no animal or animals registered in the Canadian National Records shall be certified by the Secretary of Agriculture as purebred unless such animal or animals trace, in all crosses, to animals which are proved to the satisfaction of the department to be of the same breed : Welsh Pony and Cob. Paragraph S. — The Canadian Kennel Club (Canadian National Records for dogs) is recognized for all the breeds of dogs registered in said records: Provided, That no dog or dogs registered in said records shall be certified as purebred unless a three-generation certificate of pedigree issued by said Canadian National Records is submitted for each dog. Paragraph 4- — The Holstein-Friesian Association of Canada, of which W. A. demons, of Brantford, Ontario, Canada, is secretary and editor, is recognized for the Holstein-Friesian breed registered in the Holstein-Friesian Herd Book of that association. Paragraph 1506 of the act of Congress entitled "An act to provide revenue, to regulate commerce with foreign countries, to encourage the industries of the United States, and for other purposes," approved September 21, 1922 (42 Stat. 858, 923), is as follows: 1506. Any animal imported by a citizen of the United States specially for breeding purposes, shall be admitted free, whether intended to be used by the importer himself or for sale for such purposes, except black or silver foxes: Provided, That no such animal shall be admitted free unless purebred of a recognized breed and duly registered in a book of record recognized by the Secretary of Agriculture for that breed: Provided further, That the certificate of such record and pedigree of such animal shall be produced and submitted to the Department of Agriculture, duly authenticated by the proper custodian of such book of record, together with an affidavit of the owner, agent, or importer that the animal imported is the identical animal described in said certificate of record and pedigree. The Secretary of Agriculture may prescribe such regulations as may be required for determining the purity of breeding and the identity of such animal: And provided further, That the collectors of customs shall require a certificate from the Department of Agriculture stating that such animal is purebred of a recognized breed and duly registered in a book of record recognized by the Secretary of Agriculture for that breed. may be required for the strict enforcement of this provision. Horses, mules, asses, cattle, sheep, and other domestic animals straying across the boundary line into any foreign country, or driven across such boundary line by the owner for temporary pasturage purposes only, together with their offspring, shall be dutiable unless brought back to the United States within eight months, in which case they shall be free of duty under regulations to be prescribed by the Secretary of the Treasury : And provided further, That the provisions of this act shall apply to all such animals as have been imported and are in quarantine or otherwise in the custody of customs or other officers of the United States at the date of the taking effect of this act.	2,207	common-pile/pre_1929_books_filtered	recobree00unit	public_library	public_library_1929_dolma-0011.json.gz:2838	https://archive.org/download/recobree00unit/recobree00unit_djvu.txt
3ZNySsEn1UGnx2TS	US History II	210 Primary Source: Ronald Reagan “A Time for Choosing” (1964) I am going to talk of controversial things. I make no apology for this. It’s time we asked ourselves if we still know the freedoms intended for us by the Founding Fathers. James Madison said, “We base all our experiments on the capacity of mankind for self government.” This idea? that government was beholden to the people, that it had no other source of power is still the newest, most unique idea in all the long history of man’s relation to man. This is the issue of this election: Whether we believe in our capacity for self-government or whether we abandon the American Revolution and confess that a little intellectual elite in a far-distant capital can plan our lives for us better than we can plan them ourselves. You and I are told we must choose between a left or right, but I suggest there is no such thing as a left or right. There is only an up or down. Up to man’s age-old dream-the maximum of individual freedom consistent with order or down to the ant heap of totalitarianism. Regardless of their sincerity, their humanitarian motives, those who would sacrifice freedom for security have embarked on this downward path. Plutarch warned, “The real destroyer of the liberties of the people is he who spreads among them bounties, donations and benefits.” The Founding Fathers knew a government can’t control the economy without controlling people. And they knew when a government sets out to do that, it must use force and coercion to achieve its purpose. So we have come to a time for choosing. Public servants say, always with the best of intentions, “What greater service we could render if only we had a little more money and a little more power.” But the truth is that outside of its legitimate function, government does nothing as well or as economically as the private sector. Yet any time you and I question the schemes of the do-gooders, we’re denounced as being opposed to their humanitarian goals. It seems impossible to legitimately debate their solutions with the assumption that all of us share the desire to help the less fortunate. They tell us we’re always “against,” never “for” anything. We are for a provision that destitution should not follow unemployment by reason of old age, and to that end we have accepted Social Security as a step toward meeting the problem. However, we are against those entrusted with this program when they practice deception regarding its fiscal shortcomings, when they charge that any criticism of the program means that we want to end payments…. We are for aiding our allies by sharing our material blessings with nations which share our fundamental beliefs, but we are against doling out money government to government, creating bureaucracy, if not socialism, all over the world. We need true tax reform that will at least make a start toward I restoring for our children the American Dream that wealth is denied to no one, that each individual has the right to fly as high as his strength and ability will take him…. But we can not have such reform while our tax policy is engineered by people who view the tax as a means of achieving changes in our social structure…. Have we the courage and the will to face up to the immorality and discrimination of the progressive tax, and demand a return to traditional proportionate taxation? . . . Today in our country the tax collector’s share is 37 cents of -very dollar earned. Freedom has never been so fragile, so close to slipping from our grasp. Are you willing to spend time studying the issues, making yourself aware, and then conveying that information to family and friends? Will you resist the temptation to get a government handout for your community? Realize that the doctor’s fight against socialized medicine is your fight. We can’t socialize the doctors without socializing the patients. Recognize that government invasion of public power is eventually an assault upon your own business. If some among you fear taking a stand because you are afraid of reprisals from customers, clients, or even government, recognize that you are just feeding the crocodile hoping he’ll eat you last. If all of this seems like a great deal of trouble, think what’s at stake. We are faced with the most evil enemy mankind has known in his long climb from the swamp to the stars. There can be no security anywhere in the free world if there is no fiscal and economic stability within the United States. Those who ask us to trade our freedom for the soup kitchen of the welfare state are architects of a policy of accommodation. They say the world has become too complex for simple answers. They are wrong. There are no easy answers, but there are simple answers. We must have the courage to do what we know is morally right. Winston Churchill said that “the destiny of man is not measured by material computation. When great forces are on the move in the world, we learn we are spirits-not animals.” And he said, “There is something going on in time and space, and beyond time and space, which, whether we like it or not, spells duty.” You and I have a rendezvous with destiny. We will preserve for our children this, the last best hope of man on earth, or we will sentence them to take the first step into a thousand years of darkness. If we fail, at least let our children and our children’s children say of us we justified our brief moment here. We did all that could be done. This text is part of the Internet Modern History Sourcebook. The Sourcebook is a collection of public domain and copy-permitted texts for introductory level classes in modern European and World history. Unless otherwise indicated the specific electronic form of the document is copyright. Permission is granted for electronic copying, distribution in print form for educational purposes and personal use. If you do reduplicate the document, indicate the source. No permission is granted for commercial use of the Sourcebook. (c) Paul Halsall May 1998	1,350	common-pile/pressbooks_filtered	https://library.achievingthedream.org/pimaushistory2/chapter/primary-source-ronald-reagan-a-time-for-choosing-1964/	pressbooks	pressbooks-0000.json.gz:57573	https://library.achievingthedream.org/pimaushistory2/chapter/primary-source-ronald-reagan-a-time-for-choosing-1964/
2pW9qt84YoetWS-C	16.3: The Mental Status Exam	16.3: The Mental Status Exam By the end of this section, you will be able to: - Describe the relationship of mental status exam results to cerebral functions - Explain the categorization of regions of the cortex based on anatomy and physiology - Differentiate between primary, association, and integration areas of the cerebral cortex - Provide examples of localization of function related to the cerebral cortex In the clinical setting, the set of subtests known as the mental status exam helps us understand the relationship of the brain to the body. Ultimately, this is accomplished by assessing behavior. Tremors related to intentional movements, incoordination, or the neglect of one side of the body can be indicative of failures of the connections of the cerebrum either within the hemispheres, or from the cerebrum to other portions of the nervous system. There is no strict test for what the cerebrum does alone, but rather in what it does through its control of the rest of the CNS, the peripheral nervous system (PNS), and the musculature. Sometimes eliciting a behavior is as simple as asking a question. Asking a patient to state their name is not only to verify that the file folder in a health care provider’s hands is the correct one, but also to be sure that the patient is aware, oriented, and capable of interacting with another person. If the answer to “What is your name?” is “Santa Claus,” the person may have a problem understanding reality. If the person just stares at the examiner with a confused look on their face, the person may have a problem understanding or producing speech. Functions of the Cerebral Cortex The cerebrum is the seat of many of the higher mental functions, such as memory and learning, language, and conscious perception, which are the subjects of subtests of the mental status exam. The cerebral cortex is the thin layer of gray matter on the outside of the cerebrum. On average, it is approximately 2.55 mm thick and highly folded to fit within the limited space of the cranial vault. These higher functions are distributed across various regions of the cortex, and specific locations can be said to be responsible for particular functions. There is a limited set of regions, for example, that are involved in language function, and they can be subdivided on the basis of the particular part of language function that each governs. The basis for parceling out areas of the cortex and attributing them to various functions has its root in pure anatomical underpinnings. The German neurologist and histologist Korbinian Brodmann, who made a careful study of the cytoarchitecture of the cerebrum around the turn of the nineteenth century, described approximately 50 regions of the cortex that differed enough from each other to be considered separate areas (Figure $\PageIndex{1}$). Brodmann made preparations of many different regions of the cerebral cortex to view with a microscope. He compared the size, shape, and number of neurons to find anatomical differences in the various parts of the cerebral cortex. Continued investigation into these anatomical areas over the subsequent 100 or more years has demonstrated a strong correlation between the structures and the functions attributed to those structures. For example, the first three areas in Brodmann’s list—which are in the postcentral gyrus—compose the primary somatosensory cortex. Within this area, finer separation can be made on the basis of the concept of the sensory homunculus, as well as the different submodalities of somatosensation such as touch, vibration, pain, temperature, or proprioception. Today, we more frequently refer to these regions by their function (i.e., primary sensory cortex) than by the number Brodmann assigned to them, but in some situations the use of Brodmann numbers persists. Area 17, as Brodmann described it, is also known as the primary visual cortex. Adjacent to that are areas 18 and 19, which constitute subsequent regions of visual processing. Area 22 is the primary auditory cortex, and it is followed by area 23, which further processes auditory information. Area 4 is the primary motor cortex in the precentral gyrus, whereas area 6 is the premotor cortex. These areas suggest some specialization within the cortex for functional processing, both in sensory and motor regions. The fact that Brodmann’s areas correlate so closely to functional localization in the cerebral cortex demonstrates the strong link between structure and function in these regions. Areas 1, 2, 3, 4, 17, and 22 are each described as primary cortical areas. The adjoining regions are each referred to as association areas. Primary areas are where sensory information is initially received from the thalamus for conscious perception, or—in the case of the primary motor cortex—where descending commands are sent down to the brain stem or spinal cord to execute movements (Figure $\PageIndex{2}$). A number of other regions, which extend beyond these primary or association areas of the cortex, are referred to as integrative areas. These areas are found in the spaces between the domains for particular sensory or motor functions, and they integrate multisensory information, or process sensory or motor information in more complex ways. Consider, for example, the posterior parietal cortex that lies between the somatosensory cortex and visual cortex regions. This has been ascribed to the coordination of visual and motor functions, such as reaching to pick up a glass. The somatosensory function that would be part of this is the proprioceptive feedback from moving the arm and hand. The weight of the glass, based on what it contains, will influence how those movements are executed. Cognitive Abilities Assessment of cerebral functions is directed at cognitive abilities. The abilities assessed through the mental status exam can be separated into four groups: orientation and memory, language and speech, sensorium, and judgment and abstract reasoning. Orientation and Memory Orientation is the patient’s awareness of their immediate circumstances. It is awareness of time, not in terms of the clock, but of the date and what is occurring around the patient. It is awareness of place, such that a patient should know where they are and why. It is also awareness of who the patient is—recognizing personal identity and being able to relate that to the examiner. The initial tests of orientation are based on the questions, “Do you know what the date is?” or “Do you know where you are?” or “What is your name?” Further understanding of a patient’s awareness of orientation can come from questions that address remote memory, such as “Who is the President of the United States?”, or asking what happened on a specific date. There are also specific tasks to address memory. One is the three-word recall test. The patient is given three words to recall, such as book, clock, and shovel. After a short interval, during which other parts of the interview continue, the patient is asked to recall the three words. Other tasks that assess memory—aside from those related to orientation—have the patient recite the months of the year in reverse order to avoid the overlearned sequence and focus on the memory of the months in an order, or to spell common words backwards, or to recite a list of numbers back. Memory is largely a function of the temporal lobe, along with structures beneath the cerebral cortex such as the hippocampus and the amygdala. The storage of memory requires these structures of the medial temporal lobe. A famous case of a man who had both medial temporal lobes removed to treat intractable epilepsy provided insight into the relationship between the structures of the brain and the function of memory. Henry Molaison, who was referred to as patient HM when he was alive, had epilepsy localized to both of his medial temporal lobes. In 1953, a bilateral lobectomy was performed that alleviated the epilepsy but resulted in the inability for HM to form new memories—a condition called anterograde amnesia . HM was able to recall most events from before his surgery, although there was a partial loss of earlier memories, which is referred to as retrograde amnesia . HM became the subject of extensive studies into how memory works. What he was unable to do was form new memories of what happened to him, what are now called episodic memory . Episodic memory is autobiographical in nature, such as remembering riding a bicycle as a child around the neighborhood, as opposed to the procedural memory of how to ride a bike. HM also retained his short-term memory , such as what is tested by the three-word task described above. After a brief period, those memories would dissipate or decay and not be stored in the long-term because the medial temporal lobe structures were removed. The difference in short-term, procedural, and episodic memory, as evidenced by patient HM, suggests that there are different parts of the brain responsible for those functions. The long-term storage of episodic memory requires the hippocampus and related medial temporal structures, and the location of those memories is in the multimodal integration areas of the cerebral cortex. However, short-term memory—also called working or active memory—is localized to the prefrontal lobe. Because patient HM had only lost his medial temporal lobe—and lost very little of his previous memories, and did not lose the ability to form new short-term memories—it was concluded that the function of the hippocampus, and adjacent structures in the medial temporal lobe, is to move (or consolidate) short-term memories (in the pre-frontal lobe) to long-term memory (in the temporal lobe). The prefrontal cortex can also be tested for the ability to organize information. In one subtest of the mental status exam called set generation, the patient is asked to generate a list of words that all start with the same letter, but not to include proper nouns or names. The expectation is that a person can generate such a list of at least 10 words within 1 minute. Many people can likely do this much more quickly, but the standard separates the accepted normal from those with compromised prefrontal cortices. Interactive Link Read this article to learn about a young man who texts his fiancée in a panic as he finds that he is having trouble remembering things. At the hospital, a neurologist administers the mental status exam, which is mostly normal except for the three-word recall test. The young man could not recall them even 30 seconds after hearing them and repeating them back to the doctor. An undiscovered mass in the mediastinum region was found to be Hodgkin’s lymphoma, a type of cancer that affects the immune system and likely caused antibodies to attack the nervous system. The patient eventually regained his ability to remember, though the events in the hospital were always elusive. Considering that the effects on memory were temporary, but resulted in the loss of the specific events of the hospital stay, what regions of the brain were likely to have been affected by the antibodies and what type of memory does that represent? Language and Speech Language is, arguably, a very human aspect of neurological function. There are certainly strides being made in understanding communication in other species, but much of what makes the human experience seemingly unique is its basis in language. Any understanding of our species is necessarily reflective, as suggested by the question “What am I?” And the fundamental answer to this question is suggested by the famous quote by René Descartes: “Cogito Ergo Sum” (translated from Latin as “I think, therefore I am”). It is a confusing topic to delve into, but language is certainly at the core of what it means to be self-aware. The neurological exam has two specific subtests that address language. One measures the ability of the patient to understand language by asking them to follow a set of instructions to perform an action, such as “touch your right finger to your left elbow and then to your right knee.” Another subtest assesses the fluency and coherency of language by having the patient generate descriptions of objects or scenes depicted in drawings, and by reciting sentences or explaining a written passage. Language, however, is important in so many ways in the neurological exam. The patient needs to know what to do, whether it is as simple as explaining how the knee-jerk reflex is going to be performed, or asking a question such as “What is your name?” Often, language deficits can be determined without specific subtests; if a person cannot reply to a question properly, there may be a problem with the reception of language. An important example of multimodal integrative areas is associated with language function (Figure $\PageIndex{3}$). Adjacent to the auditory association cortex, at the end of the lateral sulcus just anterior to the visual cortex, is Wernicke’s area . In the lateral aspect of the frontal lobe, just anterior to the region of the motor cortex associated with the head and neck, is Broca’s area. Both regions were originally described on the basis of losses of speech and language, which is called aphasia . The aphasia associated with Broca’s area is known as an expressive aphasia , which means that speech production is compromised. This type of aphasia is often described as non-fluency because the ability to say some words leads to broken or halting speech. Grammar can also appear to be lost. The aphasia associated with Wernicke’s area is known as a receptive aphasia , which is not a loss of speech production, but a loss of understanding of content. Patients, after recovering from acute forms of this aphasia, report not being able to understand what is said to them or what they are saying themselves, but they often cannot keep from talking. The two regions are connected by white matter tracts that run between the posterior temporal lobe and the lateral aspect of the frontal lobe. Conduction aphasia associated with damage to this connection refers to the problem of connecting the understanding of language to the production of speech. This is a very rare condition, but is likely to present as an inability to faithfully repeat spoken language. Sensorium Those parts of the brain involved in the reception and interpretation of sensory stimuli are referred to collectively as the sensorium. The cerebral cortex has several regions that are necessary for sensory perception. From the primary cortical areas of the somatosensory, visual, auditory, and gustatory senses to the association areas that process information in these modalities, the cerebral cortex is the seat of conscious sensory perception. In contrast, sensory information can also be processed by deeper brain regions, which we may vaguely describe as subconscious—for instance, we are not constantly aware of the proprioceptive information that the cerebellum uses to maintain balance. Several of the subtests can reveal activity associated with these sensory modalities, such as being able to hear a question or see a picture. Two subtests assess specific functions of these cortical areas. The first is praxis , a practical exercise in which the patient performs a task completely on the basis of verbal description without any demonstration from the examiner. For example, the patient can be told to take their left hand and place it palm down on their left thigh, then flip it over so the palm is facing up, and then repeat this four times. The examiner describes the activity without any movements on their part to suggest how the movements are to be performed. The patient needs to understand the instructions, transform them into movements, and use sensory feedback, both visual and proprioceptive, to perform the movements correctly. The second subtest for sensory perception is gnosis , which involves two tasks. The first task, known as stereognosis , involves the naming of objects strictly on the basis of the somatosensory information that comes from manipulating them. The patient keeps their eyes closed and is given a common object, such as a coin, that they have to identify. The patient should be able to indicate the particular type of coin, such as a dime versus a penny, or a nickel versus a quarter, on the basis of the sensory cues involved. For example, the size, thickness, or weight of the coin may be an indication, or to differentiate the pairs of coins suggested here, the smooth or corrugated edge of the coin will correspond to the particular denomination. The second task, graphesthesia , is to recognize numbers or letters written on the palm of the hand with a dull pointer, such as a pen cap. Praxis and gnosis are related to the conscious perception and cortical processing of sensory information. Being able to transform verbal commands into a sequence of motor responses, or to manipulate and recognize a common object and associate it with a name for that object. Both subtests have language components because language function is integral to these functions. The relationship between the words that describe actions, or the nouns that represent objects, and the cerebral location of these concepts is suggested to be localized to particular cortical areas. Certain aphasias can be characterized by a deficit of verbs or nouns, known as V impairment or N impairment, or may be classified as V–N dissociation. Patients have difficulty using one type of word over the other. To describe what is happening in a photograph as part of the expressive language subtest, a patient will use active- or image-based language. The lack of one or the other of these components of language can relate to the ability to use verbs or nouns. Damage to the region at which the frontal and temporal lobes meet, including the region known as the insula, is associated with V impairment; damage to the middle and inferior temporal lobe is associated with N impairment. Judgment and Abstract Reasoning Planning and producing responses requires an ability to make sense of the world around us. Making judgments and reasoning in the abstract are necessary to produce movements as part of larger responses. For example, when your alarm goes off, do you hit the snooze button or jump out of bed? Is 10 extra minutes in bed worth the extra rush to get ready for your day? Will hitting the snooze button multiple times lead to feeling more rested or result in a panic as you run late? How you mentally process these questions can affect your whole day. The prefrontal cortex is responsible for the functions responsible for planning and making decisions. In the mental status exam, the subtest that assesses judgment and reasoning is directed at three aspects of frontal lobe function. First, the examiner asks questions about problem solving, such as “If you see a house on fire, what would you do?” The patient is also asked to interpret common proverbs, such as “Don’t look a gift horse in the mouth.” Additionally, pairs of words are compared for similarities, such as apple and orange, or lamp and cabinet. The prefrontal cortex is composed of the regions of the frontal lobe that are not directly related to specific motor functions. The most posterior region of the frontal lobe, the precentral gyrus, is the primary motor cortex. Anterior to that are the premotor cortex, Broca’s area, and the frontal eye fields, which are all related to planning certain types of movements. Anterior to what could be described as motor association areas are the regions of the prefrontal cortex. They are the regions in which judgment, abstract reasoning, and working memory are localized. The antecedents to planning certain movements are judging whether those movements should be made, as in the example of deciding whether to hit the snooze button. To an extent, the prefrontal cortex may be related to personality. The neurological exam does not necessarily assess personality, but it can be within the realm of neurology or psychiatry. A clinical situation that suggests this link between the prefrontal cortex and personality comes from the story of Phineas Gage, the railroad worker from the mid-1800s who had a metal spike impale his prefrontal cortex. There are suggestions that the steel rod led to changes in his personality. A man who was a quiet, dependable railroad worker became a raucous, irritable drunkard. Later anecdotal evidence from his life suggests that he was able to support himself, although he had to relocate and take on a different career as a stagecoach driver. A psychiatric practice to deal with various disorders was the prefrontal lobotomy. This procedure was common in the 1940s and early 1950s, until antipsychotic drugs became available. The connections between the prefrontal cortex and other regions of the brain were severed. The disorders associated with this procedure included some aspects of what are now referred to as personality disorders, but also included mood disorders and psychoses. Depictions of lobotomies in popular media suggest a link between cutting the white matter of the prefrontal cortex and changes in a patient’s mood and personality, though this correlation is not well understood. Everyday Connection Left Brain, Right Brain Popular media often refer to right-brained and left-brained people, as if the brain were two independent halves that work differently for different people. This is a popular misinterpretation of an important neurological phenomenon. As an extreme measure to deal with a debilitating condition, the corpus callosum may be sectioned to overcome intractable epilepsy. When the connections between the two cerebral hemispheres are cut, interesting effects can be observed. If a person with an intact corpus callosum is asked to put their hands in their pockets and describe what is there on the basis of what their hands feel, they might say that they have keys in their right pocket and loose change in the left. They may even be able to count the coins in their pocket and say if they can afford to buy a candy bar from the vending machine. They will only put their right hand in their pocket and say they have keys there. They will not even move their left hand, much less report that there is loose change in the left pocket. The reason for this is that the language functions of the cerebral cortex are localized to the left hemisphere in 95 percent of the population. Additionally, the left hemisphere is connected to the right side of the body through the corticospinal tract and the ascending tracts of the spinal cord. Motor commands from the precentral gyrus control the opposite side of the body, whereas sensory information processed by the postcentral gyrus is received from the opposite side of the body. For a verbal command to initiate movement of the right arm and hand, the left side of the brain needs to be connected by the corpus callosum. Language is processed in the left side of the brain and directly influences the left brain and right arm motor functions, but is sent to influence the right brain and left arm motor functions through the corpus callosum. Likewise, the left-handed sensory perception of what is in the left pocket travels across the corpus callosum from the right brain, so no verbal report on those contents would be possible if the hand happened to be in the pocket. Interactive Link Watch the video titled “The Man With Two Brains” to see the neuroscientist Michael Gazzaniga introduce a patient he has worked with for years who has had his corpus callosum cut, separating his two cerebral hemispheres. A few tests are run to demonstrate how this manifests in tests of cerebral function. Unlike normal people, this patient can perform two independent tasks at the same time because the lines of communication between the right and left sides of his brain have been removed. Whereas a person with an intact corpus callosum cannot overcome the dominance of one hemisphere over the other, this patient can. If the left cerebral hemisphere is dominant in the majority of people, why would right-handedness be most common?	5,161	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_2e_(OpenStax)/03%3A_Regulation_Integration_and_Control/16%3A_The_Neurological_Exam/16.03%3A_The_Mental_Status_Exam	libretexts	libretexts-0000.json.gz:18049	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_2e_(OpenStax)/03%3A_Regulation_Integration_and_Control/16%3A_The_Neurological_Exam/16.03%3A_The_Mental_Status_Exam
FP2zO2sHdwF7lpNr	16.6: Complex Voltage and Current Calculations	16.6: Complex Voltage and Current Calculations There are circumstances when you may need to analyze a DC reactive circuit when the starting values of voltage and current are not respective of a fully “discharged” state. In other words, the capacitor might start at a partially-charged condition instead of starting at zero volts, and an inductor might start with some amount of current already through it, instead of zero as we have been assuming so far. Take this circuit as an example, starting with the switch open and finishing with the switch in the closed position: Since this is an inductive circuit, we’ll start our analysis by determining the start and end values for current . This step is vitally important when analyzing inductive circuits, as the starting and ending voltage can only be known after the current has been determined! With the switch open (starting condition), there is a total (series) resistance of 3 Ω, which limits the final current in the circuit to 5 amps: So, before the switch is even closed, we have a current through the inductor of 5 amps, rather than starting from 0 amps as in the previous inductor example. With the switch closed (the final condition), the 1 Ω resistor is shorted across (bypassed), which changes the circuit’s total resistance to 2 Ω. With the switch closed, the final value for current through the inductor would then be: So, the inductor in this circuit has a starting current of 5 amps and an ending current of 7.5 amps. Since the “timing” will take place during the time that the switch is closed and R 2 is shorted past, we need to calculate our time constant from L 1 and R 1 : 1 Henry divided by 2 Ω, or τ = 1/2 second. With these values, we can calculate what will happen to the current over time. The voltage across the inductor will be calculated by multiplying the current by 2 (to arrive at the voltage across the 2 Ω resistor), then subtracting that from 15 volts to see what’s left. If you realize that the voltage across the inductor starts at 5 volts (when the switch is first closed) and decays to 0 volts over time, you can also use these figures for starting/ending values in the general formula and derive the same results:	508	common-pile/libretexts_filtered	https://workforce.libretexts.org/Bookshelves/Electronics_Technology/Book%3A_Electric_Circuits_I_-_Direct_Current_(Kuphaldt)/16%3A_RC_and_L/R_Time_Constants/16.06%3A_Complex_Voltage_and_Current_Calculations	libretexts	libretexts-0000.json.gz:48776	https://workforce.libretexts.org/Bookshelves/Electronics_Technology/Book%3A_Electric_Circuits_I_-_Direct_Current_(Kuphaldt)/16%3A_RC_and_L/R_Time_Constants/16.06%3A_Complex_Voltage_and_Current_Calculations
ksgRy5r8K2nCAdBV	4.8: "There" Construction	4.8: "There" Construction “There” Construction Video Instructor Video: There Construction English is not a pro-drop language, in other words, you cannot have an English sentence in which subject is not available. This’s why, we need dummy subjects like ‘there’ and ‘it’ in English. For examples: - There is a car. - There are ten students. Unlike English though, Hindi is a pro-drop language hence subject can be dropped, or it is not needed in ‘there’ or ‘it’ sentences. In these sentences, the verb agrees with the object. For Examples: \| 1. \| English \| In my town, there is a museum. \| \| Hindi Word order \| My town in + (there) + a museum + is \| \| \| Hindi \| मेरे शहर में (___) एक संग्रहालय है \| \| \| \| 2. \| English \| In my room, there are ten books. \| \| Hindi Word order \| My room in + (there) + ten books + are \| \| \| Hindi \| मेरे कमरे में (___) दस किताबें हैं \| \| \| \| 3. \| English \| There is a computer on my desk. \| \| Hindi Word order \| My desk on + (there) + a computer + is \| \| \| Hindi \| मेरी मेज़ पर (___) एक कंप्यूटर है \| \| Activities With “there construction,” please form five sentences for describing places given below. \| Place \| Sentences \| \| \| मेरी रसोई में, In my kitchen, \| 1 \| Example: मेरी रसोई में एक चूल्हा है “There is a stove in my kitchen.” \| \| 2 \| \|\| \| 3 \| \|\| \| 4 \| \|\| \| 5 \| \|\| \| मेरे बैठक में, In my living room, \| 1 \| \| \| 2 \| \|\| \| 3 \| \|\| \| 4 \| \|\| \| 5 \| \|\| \| मेरे थैले में, In my bag, \| 1 \| \| \| 2 \| \|\| \| 3 \| \|\| \| 4 \| \|\| \| 5 \| \|\| \| मेरे स्कूल में, In my school, \| 1 \| \| \| 2 \| \|\| \| 3 \| \|\| \| 4 \| \|\| \| 5 \| धन्यवाद!	466	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Languages/Hindi/Basic_Hindi_I_(Ranjan)/04%3A_Describing_Places/4.08%3A_There_Construction	libretexts	libretexts-0000.json.gz:32948	https://human.libretexts.org/Bookshelves/Languages/Hindi/Basic_Hindi_I_(Ranjan)/04%3A_Describing_Places/4.08%3A_There_Construction
M6iACzIxatJKOYWi	Lathe design, construction and operation, with practical examples of the lathe work; a complete practical work on the lathe. Giving its orgin and development. Its design. Its various types as manufactured by different builders, etc. By Oscar E. Perrigo.	A COMPLETE PRACTICAL WORK ON THE LATHE. GIVING ITS ORIGIN AND DEVELOPMENT. ITS DESIGN. ITS VARIOUS TYPES AS MANUFACTURED BY DIFFERENT BUILDERS, INCLUDING ENGINE LATHES, HEAVY LATHES, HIGHSPEED LATHES, SPECIAL LATHES, TURRET LATHES, ELECTRICALLY DRIVEN LATHES, AND MANY OTHERS. LATHE ATTACHMENTS, LATHE WORK, LATHE TOOLS, RAPID CHANGE GEAR MECHANISMS, SPEEDS AND FEEDS, POWER FOR CUTTING TOOLS, LATHE TESTING, TURNING TAPERS, METHODS OF MILLING AND GRINDING IN THE LATHE, THREAD CUTTING, LATHE INSTALLATION, ETC. PREFACE THE aim of the Author in writing this book has been to present in as comprehensive a manner as may be within the limits of a single volume the history and development of the lathe from early times to the present day; to briefly discuss its effects upon manufacturing interests; to describe its practical use on various classes of work; and to compare in a representative, theoretical, and practical manner the Modern American Lathes as now built in this country. In carrying out these aims the early history of the lathe is traced from its crude beginning up to the time when the footpower lathe was the sole reliance of the early mechanic. Then the early history of the development of the screw-cutting or engine lathe is taken up and carried on to the middle of the last century. This is done to put the student and the younger mechanic in possession of the facts in relation to the origin and development of the lathe up to within the memory of many of the older mechanics of the present day. The matter relating to the early history of the lathe is introduced for what seem to be good and sufficient reasons. If we are always to " commence where our predecessors left off" we shall miss much valuable information that would be very useful to us. A retrospective glance on what has been, a review of previous efforts, a proper consideration of the road by wnich we came, or by which earlier workers have advanced, is not only interesting but necessary to a full and complete understanding of the subject, and very useful to us in mapping out the course for our continued advancement in contributing our share in the development of mechanical science. Following along these lines, the various types of lathes have been carefully classified, engravings and descriptions of the prominent American lathes are given, and their special features of design, construction, and use are pointed out and briefly commented upon. It is a matter of much pride to every true American mechanic that this country produces so many really good and meritorious manufacturing machines, and in no line is this superiority more clearly shown than in the magnificent array of Modern Lathes. This work brings these machines together in a comprehensive manner for the first time, and thus aims to add its quota to the present literature on this subject, and so make it valuable as a book of reference, alike to the student, the designer and the mechanic, as well as the manufacturer and the purchaser of Modern American Lathes. In the revised and enlarged edition of this work a chapter has been added detailing all kinds of lathe work, treating of lathe installation and management, milling, drilling and grinding attachments and their use, methods of turning tapers, turning spherical surfaces, making oil grooves and many other processes pertaining to practical lathe work. Endeavor has been made to have this information sufficiently clear so it may be readily followed by the apprentice, student or amateur machinist. Tracing early history. — The lathe was the first machine tool. — The origin of the lathe. — An old definition of turning. — The first record of turning operations. — Another old-time definition of turning. — English classification of lathes. — The earliest form of the lathe proper, or the old "Tree Lathe." • — The Asiatic wood turner. — The "Spring-pole" lathe. — The "Fiddle-bow" lathe. — The essential features of a lathe. — The balance-wheel applied to a lathe. — The crank, connecting rod and treadle, applied to a lathe. — Origin of the term "Pitman."-— A foot lathe built by the Author. — A foot lathe with the balance-wheel located overhead. — The friction clutch for foot-power machines .... 21 — An old device for cutting threads in wood. — Archimedes and his helical device for raising water. — Jacques Berson's French lathe. — Joseph Moxan's English lathes. — The French lathe of 1772. — John Maudsley's English lathes. — Maudsley's slide-rest. — Another French lathe. — The use of a "master screw." — A form of slide-rest. — An old-time worm and worm-gear. — Simple method of developing the screw thread. — Anthony Robinson's triple-threaded screw. — The many uses of the early lathes. — An old "chain lathe." — Cutting left-hand threads. — Crown gear and "lantern pinion" for operating the lead screw. — Transition from wooden to iron lathe beds. — The Putnam lathe of 1836. — The Freeland lathe of 1853. — Various classes of lathes The essential elements of a lathe. — The bed. — The head-stock. — The tail-stock. — The carriage. — The apron. — The turning and supporting rests. — The countershaft. — Taper attachments. — Change gears. — Classification applied to materials, labor accounts, and the handling of parts in the manufacture of lathes. — The four general classes of lat-hes. — The eighteen sub-divisions of these classes. — The first class : hand lathes, polishing lathes, pattern lathes, spinning lathes, and chucking lathes. — The second class: engine lathes without thread-cutting mechanism, Fox brass lathes, forge lathes, and roughing lathes. — The third class : complete engine lathes with thread-cutting mechanism, precision lathes, rapid reduction lathes and gap lathes. — The fourth class: forming lathes, pulley lathes, shafting lathes, turret lathes, and multiple spindle lathes. — Rapid change gear devices. — Bancroft and Sellers device. — The Norton device. — Lathe bed supports. — The precision lathe. — The rapid production lathe. — The gap lathe. — Special lathes. — Forming lathes. — Pulley lathes. — Shafting lathes. — Turret lathes. — Screw machines. — Multiple spindle lathes. — Variety of special lathes .... 50 — Conscientious efforts to improve in design. — Design of the lathe bed. — Elementary design. — Professor Sweet's observations. — The parabolic form of lathe beds. — The Author's design. — / Form of the tracks. — Bed of the old chain lathe. — The English method of stating lathe capacity. — Method of increasing the swing of the lathe. — The Lodge & Shipley lathe bed. — Uniform thickness of metal in beds. — Ideal form of bed. — Cross-ties, or bars. — Four Vs. — Flat surfaces. — Lathe bed supports. — Height of lathe centers. — Wooden legs for lathe beds. — An early form of braced, cast iron legs. — Cabinets or cupboard bases. — Old style cast iron leg still in use. — Form of cabinets. Design of head-stock for wooden bed lathes. — Early design for use on a cast iron bed. — An old New Haven head-stock. — The arch form of the bottom plate. — Providing for reversing gears. — The Hendey-Norton head-stock. — The Schumacher & Boye headstock. — The Le Blond head-stock. — The New Haven headstock. — The arch tie brace of the new Hendey-Norton design. — Generalities in describing a lathe spindle. — Designing a spindle. — Governing conditions. — The nose of the spindle. — Spindle collars. — Proper proportions for lathe spindles. — Large versus long bearings. — Design of the spindle cone 93 — The cast iron box. — Early form of boxes. — The cylindrical form. — Thrust bearings for a light lathe. — Experiments with different metals on high speeds. — Curved journals. — The involute curve. — The Schiele curve. — Conical bearings. — Adjustments to take up wear. — Split boxes. — Line-reaming boxes. — Lubrication of spindle bearings. — The plain brass oil cup. — The use of a wick. — Oil reservoirs. — Loose ring oilers. — Chain oilers. — Lodge & Shipley oil rings. — Neglect of proper lubrication. — Back gearing. — Varying the spindle speeds. — Triple gearing. — Theory of back gearing. — Back gear calculations. — Triple gear calculations. — Diagram of spindle speeds. — Faulty designing of back gears and triple gears. — Four examples. — A 14-inch swing lathe. — A 19-inch swing lathe. — A 17-inch swing lathe. — A 30-inch swing triple-geared lathe. — Explanation of the back gear diagrams. — Essential parts of the triple gear mechanism. — "Guesswork" in lathe designing. — Wasted opportunities. — Designing the head-stock. — Cone diameters. — A homely proportion. — The modern tendency in cone design. — Proportions of back gears. — Driving the feeding mechanism. — Reversing the feed. — Variable feed devices. — Rapid change gear devices 110 Functions of the tail-stock. — Requisites in its construction. — The Pratt & Whitney tail-stock. — The Reed tail-stock. — The Lodge & Shipley tail-stock. — The Blaisdell tail-stock. — The HendeyNorton tail-stock. — The New Haven tail-stock. — The Prentice tail-stock. — The Schumacher & Boye tail-stock. — The Davis tail-stock. — The American Watch Tool tail-stock. — The Niles tail-stock for heavy lathes. — New Haven tail-stock for heavy lathes. — The Schumacher & Boye tail-stock for heavy lathes. — The Bridgford tail-stock for heavy lathes. — The Le Blond tailstock. — The lever tail-stock. — The lathe carriage. — Requisites for a good design. — Description of a proper form. — A New Haven carriage for a 24-inch lathe. — The Hendey-Norton carriage. — The Blaisdell carriage. — The New Haven carriage for a 60-inch lathe. — Criticisms of a practical machinist on carriage and compound rest construction. — Turning tapers. — The taper attachment. — Failures of taper attachments. — The Reed taper attachment. — The Le Blond attachment taper. — The Lodge & Shipley taper attachment. — The Hamilton taper attachment. — The Hendey-Norton taper attachment. — The New Haven taper attachment. — The Bradford taper attachment 135 STRAIGHTENERS, ETC. Holding a lathe tool. — The old slide-rest. — The Reed compound rest. — The Lodge & Shipley compound rest. — The Hamilton compound rest. — The Hendey-Norton open side tool-posts. — Quick-elevating tool-rest. — The Homan patent tool-rest. — The Le Blond elevating tool-rest. — The Lipe elevating tool-rest. — Revolving tool holder. — The full swing rest. — The Le Blond three-tool rest. — The New Haven three-tool shafting rest. — The Hendey cone pulley turning rest. — Steady rests. — Follow rests. — The usual center rest. — The New Haven follow rest. — The Hendey follow rest. — The Reed follow rest. — The Lodge & Shipley follow rest. — Their friction roll follow rest. — Shaft straighteners. — The Springfield shaft straightener. — New Haven shaft straightener. — Lathe countershafts. — The two-speed countershaft. — Geared countershafts. — The Reed countershaft. — Friction pulleys. — Tight and loose pulleys. — Self-oiling boxes. — LATHE ATTACHMENTS Special forms of turned work. — Attachment for machining concave and convex surfaces. — Attachment for forming semicircular grooves in rolling mill rolls. — Device for turning balls or spherical work. — Turning curved rolls. — A German device for machining concave surfaces. — A ^similar device for convex surfaces. — Making milling cutters. — Backing-off or relieving attachment. — Cross-feed stop for lathes. — Grinding attachments. — The "homemade " attachment. — Electrically driven grinding attachment. — Center grinding attachment. — Large grinding attachment. — The old pin wheel and lantern pinion device. — The first patent for a rapid change gear device. — The inventors' claims. — Classification of rapid change gear devices. — The inventors of rapid change gear devices. — Paulson's originality. — " Change gear devices" by the Author. — Le Blond's quick change gear device. — The Springfield rapid change gear attachment. — The Bradford rapid change gear device. — Judd's quick change gear device. — Newton's quick change gear device. Lathe tools in general. — A set of regular tools. — Tool angles. — Materials and their characteristics. — Their relation to the proper form of tools. — Behavior of metals when being machined. — The four requisites for a tool. — The strength of the tool. — The form of the tool. — Degree of angles. — Roughing and finishing tools. — Spring tools. — Tool-holders. — Grinding / tools for tool holders. — Dimensions of tools for tool-holders. — The Armstrong tool-holders. — Economy of the use of tool-holders. — High speed steel. — A practical machinist's views on high-speed steel tools. — Conditions of its use. — Preparing the tool. — Testing the tool. — — Speeds and feeds. — Much difference of opinion. — Grinding the tools. — Amount of work accomplished by high-speed steel tools. — Average speed for lathes of different swing. — Speeds of high-speed steel drills. — Mr. Walter Brown's observations on high-speed steel. — Its brittleness. — Its treatment. — The secret of its successful treatment. — Method of hardening and tempering. Method of packing. — Making successful taps. — Speeds for the use of high-speed steel tools. — Economy in the use of high-speed steel tools. — Old speeds for carbon steel tools. — Modern speeds. — Relative speeds and feeds. — Modern feeds for different materials. — Lubrication of tools. — The kind of lubricant. — Applying the lubricant. — Lubricating oils. — Soapy mixtures. — Formula for lubricating compound. — Improper lubricants. — Various methods of applying lubricants. — The gravity feed. — Tank for lubricant. — Pump for lubricant. — Power for driving machine tools. — Calculating the power of a driving belt. — Impracticability of constructing power tables. — Collecting data relating to these subjects. — Flather's " Dynamometers and the Transmission of Power." — Pressure on the tool. — Method of calculating it. — Flather's formula. — Manchester Technology data. — Pressure on tools 214 TESTING A LATHE Prime requisites of a good lathe. — Importance of correct tests. — The Author's plan. — Devices for testing alignment. — Using the device. — Adjustable straight-edge. — Development of the plan. — Special tools necessary. — Proper fitting-up operations. — Leveling up the lathe for testing. — An inspector's blank. — The inspector's duties. — Testing lead screws. — A device for the work. — A micrometer surface gage. — Its use in lathe testing. — Proper paper for use in testing. — Test piece for use on the face-plate. — Testing the face-plate. — A micrometer straight-edge. — Allowable limits in testing different sized lathes. — Inspection report on LATHE WORK The use of hand tools. — Simple lathe work. — Lathe centers. — Care in reaming center holes. — Locating the center. — Use of the center square. — Angle of centers. — Lubrication of centers. — Centering large pieces of work. — Driving the work. — Lathe dogs. — Center rest work. — Chuck work. — Use of face-plate jaws. — Lathe chucks. — The Horton chuck. — The Sweetland chuck. — The Universal chuck. — Face-plate jaws. — A Horton four-jaw chuck. — A Horton two-jaw chuck. — A Cushman two-jaw chuck. — Chucking cylindrical work. — Inside chucking. — Chucking work supported in a center rest. — Pipe centers. — Mortimer Parker's improved forms of pipe centers. — Spider centers. — Ballthrust pipe centers. — Lathe arbors or mandrels. — Kinds of mandrels. — Expanding arbors or mandrels. — Making solid arbors. — The taper of an arbor. — Hardened and ground arbors. LATHE WORK CONTINUED Irregular lathe work. — Clamping work to the face-plate. — Danger of distorting the work. — A notable instance of improper holding of face-plate work. — The turning of tapers. — Setting over the tail-stock center. — Calculating the amount of taper. — Taper attachments. — Graduations on taper attachments. — Disadvantages of taper attachments. — Fitting tapers to taper holes. — Taper turning lathes. — Turning crank shafts. — Counterbalancing the work. — Angle plate for holding the crank shaft. — Forming work. — Forming lathes. — Drilling work on the lathe. — Chuck and face-plate drilling. — Holding work on the carriage. — Boring a cylinder. — The Author's design for boring large cylinders. — Holding work by an angle-plate on the face-plate. — Thread cutting. — Calculations for change-gears. — Reverse gears. — Arrangement of the change-gears. — Ratio of change-gears equal to ratio of lead screw to the thread to be cut. — Cutting lefthand threads. — Compound gearing. — Calculating compound gears. — Cutting double threads. — Triple and quadruple threads. — Boring large and deep holes. — The Author's device. — The drill boring bar and cutters for the work. — Flat cutters for boring bars. — Boring bar heads or arms. — Hollow boring bars. — Milling work on a lathe. — Milling and gear cutting on a speed lathe. — Grinding in a lathe. — Cam cutting on a lathe. — Many uses for ENGINE LATHES PAGE Definition of the word engine. — What is meant by an engine lathe. — The plan of this chapter. — The Reed lathes. — Reed 18-inch engine lathe. — The Pratt & Whitney lathes. — Their 14-inch engine lathe. — Flather lathes. — Flather 18-inch quick change gear lathe. — Prentice Brother's Company and their 16-inch engine lathe. — The Blaisdell 18-inch engine lathe. — The New Haven 21-inch engine lathe. — Two lathe patents by the Author. — The Hendey-Norton lathes. — Who were the pioneers in quick change gear devices? — The Hendey-Norton 24-inch engine lathe. — The Lodge & Shipley 20-inch engine lathe 286 — Emmes change-gear device. — 32-inch swing engine lathe. — Le Blond engine lathes. — 24-inch swing lathe. — The Le Blond lathe apron. — Complete drawing of a front elevation. — The Bradford Machine Tool Company's 16-inch swing engine lathe. — The American Tool Works Company's 20-inch engine lathe. — The Springfield Machine Tool Company's 16-inch engine lathe. The Bradford Tool Company's 42-inch triple-geared engine lathes. — The American Tool Works Company's 42-inch triple-geared engine lathe. — The New Haven Manufacturing Company's 50-inch triplegeared engine lathe. — The Niles Tool Works 72-inch triple-geared engine lathe. — The Pond Machine Tool Company's 84-inch engine lathe 327 Prentice Brothers Company's new high speed, geared head lathe. — A detailed description of its special features. — R. K. Le Blond roughing lathe. — Lodge & Shipley's patent head lathe. — The prime requisites of a good lathe head. — Description of the lathe in detail. — The capacity of the lathe. — A 24-inch special turning lathe built by the F. E. Reed Company. — A two-part head-stock. chine Tool Works. — Its peculiar design. — A single purpose machine. — An ideal machine for small work. — Builders who have the courage of their conviction 338 SPECIAL LATHES The F. E. Reed turret head chucking lathe. — Its special features. — A useful turning rest. — The Springfield Machine Tool Company's shaft turning lathe. — The three-tool shafting rest. — The driving mechanism. — Lubrication of the work. — The principal dimensions. — Fay & Scott's extension gap lathe. — Details of its design. McCabe's double-spindle lathe. — Its general features. — Its various sizes. — Pulley-turning lathe built by the New Haven Manufacturing Company. — A special crowning device. — Its general design. — A defect in design. — The omission of a valuable feature. — Pulley-turning lathe built by the Niles Tool Works. — A pulley-turning machine. — Its general construction. — Turning angular work. — Convenience of a bench lathe. — The Waltham Machine Company's bench lathe. — A grinding and a milling machine attachment. — Devising a special attachment. — Reed's 10-inch wood-turning lathe. — Special features of design. — Popularity and endurance. — The countershaft. — Inverted V's . . 353 REGULAR TURRET LATHES Importance of the turret lathe. — Its sphere of usefulness. — Classification of turret lathes. — Special turret lathes. — The monitor lathes. — The Jones & Lamson flat turret lathe. — Its general design and construction. — Its special features. — Its tool. — The Warner & Swasey 24-inch universal turret lathe. — General description. — Its capacity. — Taper turning attachment. — Its speeds. — The Bullard Machine Tool Company's 26-inch complete turret lathe. — Its massive form and its general design and construction. — Lubrication of tools. — The countershaft. — The Pratt & Whitney 3 by 36 turret lathe. — Its special features. — Its general design. — Its capacity. — Special chuck construction and operation. — The Gisholt turret lathe. — Its massive design and construction. — Its large capacity. — Its general and special features. — The .Pond rigid turret lathe. — Its heavy and symmetrical design. — Detailed description. — Its operation. — General dimensions .» . 370 bed. — Turret lathe for brass work built by the Dreses Machine Tool Company. — Special features and construction. — A combination turret lathe built by the R. K. Le Blond Machine Tool Company. — A useful machine with many good features. — A 15-inch swing brass forming lathe built by the Dreses Machine Tool Company. — Le Blond Machine Tool Company's plain turret lathe. — Plainness and simplicity its strongest points. — The Springfield Machine Tool Company's hand turret lathe. — A modification of their 18-inch swing engine lathe. — The Pratt & Whitney monitor lathe or turret head chucking lathe .... 391 ELECTRICALLY DRIVEN LATHES System of electric drives. — Principal advantages of driving lathes by electricity. — Group drive versus individual motor system. — Individual motor drives preferable for medium and large sized lathes. — The Reed 16-inch motor-driven lathe. — The Lodge & Shipley 24-inch motor-driven lathe. — The Prentice Brothers Company's motor-driven lathes. — General description. — CrockerWheeler motors. — Renold silent chain. — The Hendey-Norton lathe with elevated electric motor drive. — Special features. — A 50-inch swing lathe with electric motor drive designed by the Author. — Detailed description. — Practical usefulness. — Not strikingly original, but successful 405 PRACTICAL INSTRUCTIONS ON LATHE OPERATION Setting up a lathe. — Placing the lathe. — Plan of small shop. — Line shaft size and speed. — Power needed to drive lathes. — Leveling lathe. — Lubrication of lathe parts. — When to oil. — Attaching face plate or chuck. — Lathe parts and their functions. — Headstock. — Tail-stock. — Carriage.— Automatic apron. — Reverse gear. — Compound Rest. — Starting the lathe. — Operating levers. — Simple lathe accessories. — Spur and screw centers. — Drill pads. — Turning a steel shaft. — Drilling in the lathe. — Taper attachment for lathes. — Milling in the lathe. — South Bend attachment. — Barnes attachment.— Motor driven attachment.— Knurling on the lathe.— Indicators and their use. — Boring bar construction and use. — Adjustable boring bars. — Boring bars for heavy work. — Methods of holding work. — Special chuck for gas engine pistons. — Increasing swing of lathe. — Lathes for heavy work. — Grinding attachments. — Machining concave and convex surfaces. — Grooving oil ducts. — Combination lathe dogs and their use. — Hacksaw attachment for lathes 417 INTRODUCTION IN the great measure of success that has been enjoyed, and the vast volume of wealth that has been produced in this, the most industrial of all countries, the manufacturing industries easily lead all other productive interests in which the people are engaged. While in the earlier years of American independence the chief dependence was upon the results of agriculture, the development of the resources of the country in time has placed manufactures at the head of the list so that in very recent years the value of manufactures has been nearly double the amounts of that produced by agricultural pursuits. These results, like many others of a less notable character, commenced from small beginnings, and it has been by inborn mechanical talent, remarkable ingenuity, patient development, and tireless energy, that mechanical undertakings large and srriall have been developed, until the American mechanic leads the world in originality and practical achievement in our vast manufacturing enterprises. When the early settlers, the Puritans of New England, labored under the restrictive and harassing laws of the mother-country, and under their administration were goaded and exasperated beyond endurance in many ways, not the least of which was being obliged to purhase all their manufactured articles from England at extortionate prices, or from other countries and still paying taxes to England, they rebelled and determining to buy no more foreign goods, set out, at first in very primitive and clumsy ways, to make such articles as were really necessary, and in magnificent self-denial to get along without those which they could not produce, they little realized that they were thus laying the foundations of the greatest manufacturing country in the world. It is true that the coming of the Pilgrims, their departure from the old country, was for religious freedom, but freedom soon meant vastly more to them than this, and with this larger conception of their opportunities, some of which were really forced upon them by adverse circumstances, came the inspiration of industrial as well as religious freedom. And the determined manner in which they set about their self-appointed task has amply demonstrated to their posterity and to the world their grasp of the possibilities and conditions of the situation as well as their breadth and nobility of character. Thus sprang American manufactures into being, beginning with crude efforts to fashion those common objects of household necessity and daily use, which, clumsy though they were, yet served their practical purposes, to be supplanted later on by those more improved in form, design, and workmanship and better adapted to the uses for which they were made. The primitive successes of these early efforts led to greater endeavors, and the ingenuity displayed where " necessity was the mother of invention" was naturally developed into a still broader usefulness when the time came that necessities having been reasonably provided for, luxuries were thought necessary in the higher plane of living to which the people in due course had advanced. And so it came about that the rude and crude beginnings in which the early mechanic performed his work in his own house outgrew these homely facilities and he built small shops, frequently in the gardens or back yards of the dwellings. These gradually enlarged; then came the necessity for still greater facilities, and buildings were erected quite independent of the home surroundings and two or more men were associated as manufacturers, and these became in due course of time the machine shops and the factories, which have multiplied many hundreds of times, not only in numbers and in value, but in influence and in importance, until to-day our country stands the leading manufacturing nation of the earth. And this may be said, not only as to the volume and the value of her manufactured productions, but also as to their great range and diversity of kind and degree. One after another the American mechanic has taken up the work formerly monopolized by this country or that, failing perhaps at first, but always progressing, always advancing, until by native ingenuity and tireless energy all obstacles have been surmounted, all difficulties brushed aside, new industries spring into being and other "victories of peace greater than the glories of war" are added to the credit of the American mechanic and his ever ready and ever confident partner, the American manufacturer and capitalist. And to this combination, each confident of and faithful to the abilities of the other, and each in his own sphere of usefulness, is due the immense success of the manufacturing American of to-day. In the early stages of manufacturing in this country all the tools and appliances were of a very crude and primitive kind and consisted mainly of a limited number of hand tools that had been brought with them from the old country, and occasionally a hand lathe of moderate dimensions, operated by foot-power. Yet with even these few facilities much important work was accomplished in the way of useful machines such as the flax and woolen spinning wheels and their accessories, and the wooden looms in which the yarn thus prepared was woven into the coarse but excellent cloth of these early times. Then with the few tools and meager facilities possessed by them these old-time mechanics proceeded with practical common sense, ingenuity, and patience to design and construct other tools and machines such as by the necessities of occasion was manifest, and the increasing demands for them required better tools, better machinery, and facilities of a wider scope. The mechanic was then, as now, equal to the emergencies of the situation in which he found himself, and from small beginnings, and many of the parts of his machines made of wood, for lack of forge and foundry facilities, particularly the latter, has developed the machine tools of the present day. The lack of facilities for making iron castings was very early felt, and history tells us that as early as the year 1643 John Winthrop arrived in this country from England, bringing with him the necessary number of skilled workmen for this purpose, and built a small iron foundry in Lynn, Mass.; and the fact that the first casting produced was "a small iron pot holding about a quart " shows that the foundry was of very moderate capacity, and it is very likely that the blast used in melting the iron was produced by a hand bellows, as the blacksmith forge had preceded the foundry here, as it did, probably, in all other countries. The quart pot was cast from iron "made from native ore," although we do not know where they obtained it; probably from some place in the vicinity where it was found in small quantities. From this small beginning there was very little progress made for a considerable time in enlarging either the original scope of the work or in increasing its facilities, so far as we have any record. In 1735, nearly one hundred years later, we know that an iron foundry was built in the little town of Carver, Mass., and that a second one was put up in the same town in 1760, although we do not know the reason for this second one coming into existence in the same town unless it was that the first one had been destroyed by fire. However, it was in this second foundry that the historic " Massachusetts Teakettle" was cast. We do know that still another foundry was built in this town in 1793 and that this was burned down in 1841. Thus early did the custom begin, which is still in vogue in eastern Massachusetts, of devoting the energy of a town to one line of manufacture. While these events and evidences of mechanical progress were taking place, the active minds of ingenious workmen were busily engaged in solving the practical problems of the growing demands made upon the shops and embryo manufactories engaged in supplying the wants of the people. New methods of manufacture, by which the quality as well as the quantity turned out could be improved, were demanded. This led to the demand for more machinery, which in turn led to the demand for better machines for the use of the mechanic, or for what we have come to know as machine tools. In the meantime the main reliance had been upon the ancient foot lathe, and with it much of their mechanical work had been accomplished. It had been improved in various ways, both in its design and in the materials of which it was constructed, and with the use of water-power for driving the machinery for manufacturing operations the lathe had become of greater usefulness by being driven in the same manner. Yet from the first it main- tained its prominence as the first of the machine tools and the one which made all of the others that came after it possible of construction and useful in their several and respective spheres. In the great scheme of manufacturing and the immense industrial problem of supplying the wants of the people in this respect by modern manufacturing plants equipped with all that is latest and best in machinery, it should be said that at the very basis and foundation of the whole stand the modern machine tools; that it is to the great and important development of these that we owe, primarily, our industrial prosperity as a nation. And to them may be easily traced the gradual upward tendency of the mechanic from the hard physical toil and laborious work of early days to the immeasurably lighter exertions made possible by the highly developed condition of the automatic machines of the present day. It has been, as was said in the outset, a victory of mind over matter, wherein brains have won where the hands made little advance; ideas developed wonderful mechanisms that have revolutionized the earlier methods of manufacturing, raised the standard of mechanical excellence beyond what was thought possible years ago, and at the same time reduced the cost to a fraction of its former amount. But to attain these marvelous results many machines have been required. All conceivable types and styles, and for an almost endless variety of purposes, have been designed, built, and perfected until hardly a possible mechanical operation is performed without the aid of a machine, frequently special in its design and automatic in its action, is brought into use, performing the work with surprising speed and wonderful accuracy. The construction and perfection of all this magnificent array of highly developed machinery has only been made possible through the use of the machines for the use of the machinist, the machine tools of the present day, which must first have been perfected and adapted to the many needs and requirements which the advanced state of mechanical science demanded. These machine tools were made possible by the earlier examples of the most simple devices in this direction, chiefly, in our own time, the foot lathe, by which many of the earlier tools and machines were for the most part built; and as new uses for it were found new devices, attach- ments, and accessories were devised and applied, and in this gradual development and improvement in its design, its construction, and the materials of which it is built, the early and crude foot lathe has become the magnificent machine of the present day, and in which the American mechanic takes a just and pardonable pride. As to how this development progressed will be discussed in the opening chapters, and it is hoped that it will be found interesting to every American mechanic and particularly to the apprentice who is about to start out with learning the honorable trade of a machinist, and the student who would know from whence our modern machine tools were derived, that he may perhaps, in due time, become one of those who shall aid in their further development and perfection, as well as to the elder mechanic who uses these machines, and the mechanical engineer who is busy with their present development. It is always profitable to take a retrospective glance at the former state and condition of the matter upon which we are engaged, in order that we may not only realize from whence came the models built by the men who came before us, and to draw therefrom an inspiration for our own best efforts, but knowing the mistakes that have been made by others, to seek to avoid repeating them in our own experiences, our experiments and our designs by which we seek to add to the sum total of mechanical knowledge and improvement. HISTORY OF THE LATHE UP TO THE INTRODUCTION OF SCREW THREADS Tracing early history. The lathe was the first machine tool. The origin of the lathe. An old definition of turning. The first record of turning operations. Another old-time definition of turning. English classification of lathes. The earliest form of the lathe proper, or the old "Tree Lathe." The Asiatic wood turner. The "Springpole" lathe. The "Fiddle-bow" lathe. The essential features of a lathe. The balance-wheel applied to a lathe. The crank, connecting rod and treadle applied to a lathe. Origin of the term "Pitman." Afoot lathe built by the Author. Its detailed construction. A foot lathe with the balance-wheel located over-head. The friction clutch for foot-power machines. THE subject of the present work being the lathe and its work, and more particularly its design, construction, and development in our own country and in recent years, and as briefly comprised in our title of Modern American Lathe Practice, our efforts will be directed, first, to a brief notice of its origin and early development and use as a simple hand lathe; second, to its more modern development as one of the most important machine tools in the equipment of machine shops; and, third, to the various modifications of it, following its development through all its various forms and for the diversity of manufacturing purposes to which it has been adapted up to its present degree of efficiency. In considering a subject of the vast importance of the modern lathe and its far-reaching influence upon the mechanical world of to-day, it cannot but be interesting to go back to its early history and to trace its progress and development from as far back as we have any authentic knowledge, and step by step to note the changes in its form and usefulness as the mind of the early mechanic developed, new requirements manifested themselves, and improvements in design, construction, tools, and attachments were devised to meet the growing needs. 22 MODERN LATHE PRACTICE It is conceded that of all the machines employed by the mechanic to aid him in his work the lathe holds the honor of having been the first machine tool, From it, in one way or another, all other machine tools have been developed; as they are, practically considered, but modifications of it, or special tools for doing quicker and better, the several operations which may be, and formerly were, performed upon the lathe, as we shall later on have occasion to describe and illustrate. At present we will look into the origin of the lathe and then trace its gradual evolution and development up to comparatively recent years, say an hundred years or so ago, as their development into anything like mechanical importance has been confined to the last century which has been so remarkable in this respect. Upon referring to the older records on the subject of lathes and their uses we find this statement: " Turning is the art of shaping wood, metal, ivory, or other hard substances into forms having a curved (generally circular or oval) transverse section, and also of engraving figures composed of curved lines upon a smooth surface, by means of a machine called a turning-lathe. This art is of great importance and extensive application in mechanics, the most delicate articles of luxury and ornament, equally with the most ponderous machinery, being produced by it. The art of turning dates from a very early period, and Theodorus of Samos, about 560 B.C., is named by Pliny as its inventor; but long before this period, the potter's wheel, the earliest and simplest form of turning-machine, was in general use, as is evidenced by numerous references in Holy Writ." Again we read in an old-time definition of what turning really consists of: "The immense variety of work performed by turningmachines necessitates great variations in their construction; but mode of operation is always the same, and consists essentially in fixing the work in position by two pivots, or otherwise, causing it to revolve freely around an axis of revolution, of which the two pivots are the poles, and holding a chisel or other cutting-tool so as to meet it during its revolution, taking care that the cuttingtool be held firmly and steadily, and moved about to different parts of the work till the required shape is obtained." HISTORY OF THE LATHE classification to them somewhat different from that in this country. Hence the following: " Lathes are divided, with respect to the mode of setting them in motion, into pole lathes, foot lathes, handwheel lathes, and power lathes; and with respect to the species of work they have to perform, into center lathes, which form the outside surface, and spindle, mandrel, or chuck lathes, which perform hollow or inside work, though this distinction is for the most part useless, as all lathes of good construction are now fitted for both kinds of work." Another peculiarly English idea in reference to lathes is this: "Bed lathes are those used by turners in wood, and bar lathes for the best sort of metal work; and the small metal center lathe employed by watchmakers is known as a turnbench." other tool with which the turning or cutting is to be done. The power for rotating the piece C to be turned is obtained by attaching a cord D to a flexible limb of the tree, passing it one or more turns around the piece and forming in its lower end a loop for the foot of the operator,, who rotates the piece towards himself by depressing the foot, bending down the limb by the. movement, which, when he. raises his foot, returns to its original position, rotating the piece backwards in readiness for another pressure or downward stroke of the foot. The work was slow and laborious, yet from old samples of the pieces thus produced we may see that an extraordinary good quality of work could be done, particularly considering the primitive methods used. We read that: " Wood-turners in some of the Asiatic countries go into the deep forests with axes, and with a few rude turning tools and hair ropes build their lathes and turn out objects of beauty and grace, says the Wood Worker. Two trees are selected which stand the proper distance apart near a springy sapling. With his ax the turner cuts out his centers and drives them opposite each other into the trees, which serve as standards. From one tree to the other he places a stick of wood for a tool-rest. With his ax he trims the branches from the sapling, fastens his hair rope to the little tree, gives the rope a turn around one end of the block of wood he desires to turn into shape, and fastens the free end of the rope to a stick which he uses as a foot treadle. When he presses down on the treadle the wood he is turning revolves, and the spring of the sapling lifts the treadle so that it can be used again." The next form of lathe to which these crude efforts seem to have led was one in which the flexible limb, though in another form, was used, but the device became very nearly a self-contained machine. A piece of wood formed a bed for the lathe and to this was fixed the blocks forming the centers, which have since become the head and tail stocks of the lathe. The machine appears to have been used in doors, as the flexible limb of the tree had been replaced by a flexible strip or pole, " fastened overhead" and called a "lath" from which circumstance some writers think that the name "lathe" was derived. The driving cord was still wound around the piece to be turned. No mention is made of the method of supporting the tool, but it is probable that a strip of wood was fastened to the "bed" for that purpose. The next improvement in developing the lathe brings its form within the memory of the older mechanics and is shown in Fig. 2. In this case there is a rude form of head-stock B, and tail-stock E; both constructed at first of wood, and the tail-stock continuing to be so constructed for many years. In this form of lathe the head spindle is first found, having in the earlier examples a plain " spool" around which the driving cord D was wound, and later on a cone pulley constructed as shown in Fig. 3, by which a faster speed was possible with the same movement of the foot. The lower end of the driving cord was fastened to a strip of wood F, the farther end of which was pivoted to the rear leg, in the later examples of the " spring-pole lathe," as it was then called, the bed having been mounted upon legs as shown. a short distance apart, properly secured at the ends. This afforded a space down through which passed a long tennon formed upon a wooden block answering for a tail-stock E. This was held in any desired position by a wooden key, passing through it under the bed. What was the early form of rests for this lathe does not seem to be known, but somewhat later the rest was constructed of cast iron and very much as in an ordinary hand lathe of the pattern-maker or wood-turner of the present day, and as shown in Fig. 2. This lathe was used for both wood and metal, the tools being held in the hand as the slide rest had not yet been invented, as will be seen later on in this chapter. cone pulley, as shown in Fig. 3, some workman discovered, probably by turning a heavy piece, that its forward motion would continue when the foot was raised, provided the tool was withdrawn from contact with the work. It was but natural to make the cone pulley of heavier material, as of cast iron, or to weight it with pieces of iron or with lead plugs cast into it, and thus make it serve the office of a balance-wheel and so keep up the forward revolution of the work as long as it was given the proper impetus by the downward strokes of the foot. Another style of lathe that was used mostly for small work, generally metal work, was called a " fiddle-bow lathe," on account of the method of driving it. In this lathe, which is shown in Fig. 4, the same idea of propulsion is used as in the former examples, that of a cord passing around either the piece to be turned or a rotating part of the mechanism by which the piece was revolved. In this case, however, instead of the resistance of the flexible limb of a tree or of a " spring pole" acting to keep the driving cord taut, it is held in that condition by the flexible bow F, which is bent to the form shown by the driving cord D. The engraving is an exact reproduction of a lathe, the bed A of which was about twelve inches long and it had a capacity of about two inches swing, that was made by an older brother for the use of the author when he was nine years old, and in the use of which he became quite a boyish expert in turning wood and metals. The head-stock B, and rest C, were formed of bent pieces of wrought iron, and the "spur center" was formed upon the main spindle, the point being used as a center for metal work. with them. The main features in all these lathes were, first, to suspend the work to be done, or the piece to be operated upon, between two fixed pivots or centers; second, to revolve it by means of a cord wrapped around it, or some part of the machine fixed to it, and kept tightly strained by means of some kind of a spring, as an elastic piece of wood; and third, to reduce the piece to be operated upon by means of a tool having a cutting edge which was held tightly against the material to be operated upon, thus reducing it to the circular form required; fourth, that to accomplish this it was necessary to revolve the piece to be operated upon, first towards the cutting tool for a certain number of revolutions, then by a reverse motion of the taut cord to reverse the circular motion, at the same time withdrawing the cutting-tool for an equal number of revolutions. By this method one half the time was lost, as no cutting could be done while the work was running backward. It was later found that if the flexible pole or "lath" was rather weak and the piece of work to be operated upon was quite heavy, acting as a balance-wheel, its forward revolution was not wholly arrested, but only checked as the foot was raised, provided the cutting-tool was withdrawn from contact with the work a moment before the upward motion of the foot began. By this it was seen that great advantages might be gained if the lathe could be made to not only revolve continuously in the direction of the tool, but also with the same force, whereby the tool might be kept in constant contact with the work. known. Doubtless an assistant had furnished the power to drive the lathe while the mechanic handled the tools. What would be more natural than the arrangement of a large wheel, journaled to a suitable support at the front or rear of the lathe, and having the cord connected with it as a driver. And with this device and the problem of revolving it by hand, a handle set between its center and circumference would be natural also, and thus came the crank. We do know that somewhat later than this machines were driven in exactly this manner, the large wheel being constructed with a heavy rim and acting as a balance-wheel. At this stage of development the large driving-wheel was rather an attachment than a part of the machine itself, and doubtless so remained for a considerable time. The next change was to locate it beneath the lathe bed, directly under the head-stock, and instead of the use of the handle forming practically a crank of long leverage it was constructed as it is in the sewing-machines of the present day; that is, the wheel journaled upon a fixed stud and the previous long handle reduced to a wrist-pin for the attachment of a connecting rod, or in the older phrase a " pitman," which term was given to one of the men handling the vertical saw used in sawing up logs into timber and planks in the olden times (and even now in oriental countries), wherein the log was supported over a trench or pit, the upper end of the saw being handled by the "topman" and the lower end by the " pitman" or man in the pit. When these saws were later on mounted in a rectangular frame or "gate" having a vertical, reciprocating movement and operated from a crank-shaft by a connecting rod from the one to the other, this rod took the name of the former man who performed this office, hence the term "pitman." The location of this pitman or connecting rod, as has been said, was directly under the head-stock and well within the convenient reach of the operator when attached to a suitable "treadle" whose rear end was pivoted to the back of the machine and whose front end formed a resting-place for the operator's foot. This arrangement answered very well and was useful when the work of the lathe was near the head-stock, but was not adapted to long work, to accomplish which the operator would need to stand near the tail-stock or even midway between that and the head-stock. To remedy this defect a strip of wood was hinged to the front leg of the lathe at the tailstock end and its opposite end to the front end of the treadle. This was of considerable use, its principal drawback being that while at the treadle end its vertical movement was the same as the latter, this movement was gradually lessened until at the tail-stock end of the lathe it was nothing. Hence, much more power was required to drive the lathe at its center than at the head-stock, and this was rapidly increased as the work was nearer the tail-stock end of the lathe. To remedy this defect the large driving-wheel was mounted upon and fixed to a revolving shaft upon which was formed two cranks, one near the wheel and the other at the tail-stock end of the lathe. This shaft was properly journaled in boxes formed upon or attached to cross-bars fixed to the legs at each end of the lathe. From these cranks hung two connecting rods whose lower ends were pivoted to two levers pivoted to the rear side of the lathe, and whose front ends were connected by a wooden strip or " foot-board." The length of these levers was such that the movement of the foot-board was about twice the " throw" of the cranks, so that with a foot movement of twelve inches the two cranks were about three inches, center of shaft to center of connecting rod bearing. This was then and for many years the prevailing form of foot lathes and was quite extensively used, not only for turning wood but for iron, steel, and other metals as well. There were many of the older mechanics who would work the entire day through. At that time a day's work was not eight, nine, or ten hours, but "from sun to sun," or from daylight till sunset, day after day, treading one of these foot lathes and turning out a much larger quantity of work than these crude facilities would seem to render possible. In Fig. 5 is shown this form of foot lathe that was in use for many years for turning both wood and metals. The illustration is a drawing of a lathe built by the author when he was between fifteen and sixteen years of age. The bed A, legs B, the cross-bars C, C, the back brace D, and treadle parts E, F, were built of wood, as was also the tail-block G, which was of the form shown in Fig. 4, except that beneath the screw forming the tail center was a wooden from strain and vibration, for the screw to work loose. The tool-rest was of the usual form, except that instead of a wedge, in connection with the binder H, to hold it in position, or the use of a wrench on the holding-down bolt, an eccentric of hard wood with a handle formed upon it, as shown at J, was used. This was the first occasion where the author saw an eccentric used for a similar purpose. It worked so well that he fitted similar eccentrics to the stops of the three windows in his little workshop to hold the sashes in any desired position when they were raised, and by closed. The large wheel was of cast iron, rescued from a scrap heap, and had only the grooves for the two faster speeds K, L, the part M being made of wood and fastened to the arms of the wheel. A friendly blacksmith forged the cranks in the shaft N, and the eyes in the lower ends and hooks in the upper ends of the connecting rods P, P. These were first made of wood similar to the connecting rods on a sewing-machine with a closed bearing at the top, but the tendency to pinch one's toes under the treadle when they happened to be accidentally placed in this dangerous position soon led to the iron connecting rods with the hooked ends whereby the worst that could happen was the connecting rods becoming unhooked. The shaft N rested in wooden boxes, the lower half being formed in the cross-bars C, C, and a wooden cap held down by two wood screws forming the top half. The bearings of the shaft and the cranks were filed as nearly round as they could be made by hand with the means and ability available. The pattern for the head-stock was made as shown in side elevation in Fig. 5, with the housings for the spindle boxes as shown in Fig. 6. The boxes were made in halves, of babbitt metal and cast in place in the head-stock in this manner. The head spindle was located in place and held by a thin piece of wood clamped on the inside and outside of the housing and having semicircular notches in their upper edges and a slight recess on their inner sides so as to provide for The lower halves of the boxes, having been cast slightly higher than the center of the spindle bearings, were removed and filed down to the proper level and then replaced, the spindle again laid in, the strips of wood clamped on in an inverted position and the top half of the box cast. This part projected slightly above the top of the iron casting and was held down by an iron cap having two holes drilled in it which fitted on the threaded studs R, R, which had been cast into the head-stock for this purpose. The spindle had been turned up in an old-style chain-feed lathe, of which more will be said later on. The cone pulley S was of cherry, simply driven on tightly and turned up to the form shown. The front end of the spindles was threaded but not bored out. Upon this thread was cast a babbitt metal bushing T, having a square hole in its front end, which was formed as follows: With the spindle in its place a wooden mold of proper form was placed around it and, while it fitted the collar on the spindle at one end, was open at its front end. A tapering, square piece of iron of proper dimensions to form the square hole was placed with its small end against the nose of the spindle and held in that position by the tail screw. The opening around it was closed by a piece of wood of proper form and the job was " poured," and the bushing afterwards turned up with a hand tool. Into this square hole could be fitted proper centers for turning wood or metal, and by removing the babbitt metal collar a face-plate could be put on for face-plate work. It will be noticed that the lathe had been arranged for two speeds proper for turning wood and the softer metals, and one speed considerably slower for iron. A piece of belting was provided which could be easily removed to shorten the belt the proper amount for this purpose. The lathe would swing eight inches and take in between centers four feet. It was found that the round belt did not give sufficient driving power and a new spindle cone of only two steps was put on, the iron balance-wheel lagged up for a flat belt, and the pulley M turned down for the same purpose. This permitted the use of a belt an inch and three-quarters wide, and as no regular belting was available when the job was done an old trace from a harness suffering from general debility was ripped open and a single thickness of the leather soaked up in water, dried out, treated with neat's-foot oil and used with such good results that it was never replaced. To this lathe was fitted a small circular saw provided with an adjustable, tilting table upon which not only wood but sheet brass could be cut. Another attachment was a small jig-saw that would cut off wood up to half an inch thick. One of the disadvantages of the usual form of foot-power lathe was the short connecting rod or pitman which thereby formed too great an angle to the center line from the wheel center to the point of attachment to the treadle, thereby increasing the friction and decreasing the useful effect of the foot-power. It was apparently to avoid this condition that a somewhat peculiar form of lathe was devised and built in the railroad shops at Plattsburgh, N. Y., about 1860, and which is shown in end elevation in Fig. 7. This was an engine lathe of about fourteen-inch swing, built with cast iron bed A, legs B, and all the parts of metal that are now so constructed. Instead of placing the large driving or balance wheel beneath the lathe bed as formerly, the lathe was belted from a cone pulley of three steps^on an overhead countershaft C, provided with the usual hangers D. This countershaft was of a length equal to the length of the lathe and had fixed at the end over the head of the lathe a heavy wheel E, into the hub of which was fixed a stud or wrist-pin F, while on the opposite end of the countershaft was fixed a disc for carrying a similar stud. These formed two cranks to which were fitted long connecting rods G, the lower ends of which were pivoted to the treadles H, whose rear ends were pivoted to the legs B, as at J. The treadles H are located outside of the legs B, and connected by the foot-board K. The weight of the connecting rods G, the treadles H, and the foot-board K are balanced by the proper counterbalance added to the fly-wheel E, as shown. The author knows from personal observation that this lathe would run very steadily and with a good deal of power, and that its general performance was much better than foot lathes of the usual type. Doubtless the momentum of the balance-wheel, cone pulley, and countershaft was very beneficial in maintaining an equable speed under varying conditions of resistance from the operation of cutting-tools and the like, while the cast iron cone pulley on the main spindle did some service in the same direction. The only disadvantage in this lathe was that it required too long a time to get it up to its regular speed and necessarily too much time was consumed in stopping it, as there was no provision for disconnecting the lathes of recent design. There has been manufactured for some years a special type of friction clutch that is very useful in driving foot-power machinery. It consists essentially of a drum mounted upon and loosely revolving around the shaft to be driven, and having a friction, clutch mechanism contained within it and so operating that the drum will turn freely in one direction but the moment it is revolved in the opposite direction the friction device comes into operation, the drum is firmly clamped to the shaft, which is thus caused to rotate with it. To this drum is attached one end of a flat leather belt, which is wrapped around it several times and its free end attached to the movable end of a treadle, which is usually hinged at the front instead of the back of the machine. In operation the pressure of the foot acting on the drum by means of the belt rotates it in the forward direction, which causes its friction mechanism to act and revolve the shaft through as many revolutions as there are convolutions of the flat belt around the drum. The rotary motion thus set up is continued by the momentum of a balance-wheel, and as the foot is raised the treadle is caused to follow it, either by the action of a spring similar to a clock spring within the revolving drum, or a spiral spring acting upon another strap, also wrapped around the drum, but in the opposite direction to the one attached to the treadle. By this device several revolutions of the driving-shaft could be produced at each depression of the foot, the treadle frequently passing through an arc of thirty to forty degrees. This device was particularly applicable to the driving of light foot-power machinery which it did very successfully, and as the strokes of the foot need not be of the same length and were not confined to any certain cadence it was not nearly as fatiguing as the crank device in which the strokes of the foot were always the same distance and with the same speed. In the above described device, however, the balance-wheel was more necessary and it was also necessary that it should be so arranged as to revolve with a much higher rate of speed than the large wheel of the older form of foot lathe. There was one advantage in this condition, however, that in consequence of its higher speed the balance-wheel could be made of much smaller diameter and consequently much lighter in weight, and therefore occupying much less space under the machine. SCREW THREADS Origin of the screw thread. Ancient boring tools. Suggestions of the screw form. The "Worm Gimlet." Making the first nuts. An old device for cutting threads in wood. Archimedes and his helical device for raising water. Jacques Berson's French lathe. Joseph Moxan's English lathes. The French lathe of 1772. John Maudsley's English lathes. Maudsley's slide-rest. Another French lathe. The use of a "master screw." A form of slide-rest. An old-time worm and worm-gear. Simple method of developing the screw thread. Anthon Robinson's triple-threaded screw. The many uses of the early lathes. An old "chain lathe." Its detailed construction. Cutting left-hand threads. Crown gear and "lantern pinion " for operating the lead screw. Transition from wooden to iron lathe beds. The Putman lathe of 1836. The Freeland lathe of 1853. Various classes of lathes to be illustrated and described. THE origin of the screw thread, or the threaded screw, reaches so far back into ancient times that it is impossible to determine when, where, or by whom it was first conceived or used. That it was known in one form or another as far back as the use of iron for tools is altogether probable. Holes must have been made in wood by some kind of an iron instrument which was the predecessor of the gimlet. This instrument was most likely square or of some form nearly approaching that. In order to be at all effective it must have had sharp corners. As the straight-edged sharp knife was first accidentally and then purposely hacked into notches and became the first saw, so may the corners of the early boring instruments have had notches formed in them to facilitate their action upon the material to be bored. These notches may have been gradually deepened for the same purpose, with the idea that the deeper they were the more useful they would become. We can very readily conceive that in making these notches the tool was laid on its side and gradually revolved as the notches were made, beginning at the point and working upwards as the tool was revolved. This of itself would have a natural tendency to produce a semblance of a screw thread, which would increase the efficiency of the tool by drawing it into the wood to be bored. When this tendency was noticed it was also natural to see why it acted in this manner and to increase this action by more carefully making these notches. In time the "worm gimlet" was undoubtedly evolved. The form of a screw thread having once been arrived at, the realization of its usefulness for various purposes was only a question of time. It is altogether probable, however, that for the purpose of holding parts of a machine together, or for similar mechanical purpose, screws were first made of wood. It is also pretty certain that they were first made in a very crude form without much regard to the exactness of the pitch or form of the thread, although the V-thread would be the most natural because the most simple form. It is also generally conceded, of course, that they were made by hand and probably with the rude knives then used, as hand tools were the only ones in use. As to the methods used in making the first nuts for use with the screws, it is probable that they were quite thin as compared with the pitch of the thread, possibly containing but two the nut in this manner. We do know for a certainty that a somewhat similar means was used many years later, as the author saw a device such as is represented in Fig. 8, which was preserved as a curiosity, representing the early mechanical method of doing this work. DEVELOPMENT OF THE LATHE 37 very hard wood, having one end turned down to a diameter equal to that at the bottom of the thread, while the opposite end was made much larger and contained a hole for passing a bar or lever by means of which it was rotated. At the termination of the thread and beginning of the smaller straight portion the thread was cut away, leaving an abrupt termination, and at this point was inserted a tooth of steel formed in a rough manner to the shape of the thread. piece B, to be tapped or threaded, was clamped to this by means of the steel clamps E, E, binding the two firmly together. To all appearances the tooth or cutter d could be set in or out so as to cut merely a trace of the thread the first time through, then another deeper cut, and finally finished to the full depth. The author had no means of ascertaining the origin of the device, but the wood of which it was composed was black with age and the man who possessed it could not tell how many years his father had owned it or where he got it. It was certain, however, that both of them had been mechanics who had made and repaired the old-time wooden spinning-wheels in which a wooden screw about one inch in diameter had been used for tightening the round band by which the twisting mechanism was operated. Archimedes, the most celebrated of the ancient mathematicians, certainly had a good idea of the screw thread, as is shown in his famous screw made of a pipe wound helically around a rotating cylinder with which he raised water fully two hundred years before the Christian era. Still it was doubtless a long time after this period before the screw was constructed so as to be applicable to the uses of the present day. Of the progress and development of this and other similar mechanical matters in these early times we have little authentic information. The development of such simple machines as the lathe preceded much that was mechanically important, and to its influence we owe a great deal of the early advancement in the mechanic arts. We know that a Frenchman by the name of Jacques Berson, in 1569, built a lathe that seems to have been capable of cutting threads on wood. An engraving of his lathe is given in Fig. 9. As will be seen in this engraving it was a large, clumsy and cumbersome affair, considering the work it was designed to perform. While the various parts of the machine are not very clearly shown, enough is given to show us that he had a wooden lead screw to give the pitch of the thread by means of a half nut which appears to have been fixed in a wooden frame, to which in turn the piece to be threaded was attached by being journaled or pivoted upon it. The lead screw and the piece to be threaded were both revolved by means of cords wound around spools or drums upon a shaft overhead, and held taut by weights instead of the flexible spring pole already described. These cords were fastened to a vertically sliding frame, also balanced by cords and weights, and to which was attached a sort of stirrup adapted to the foot, by which the machine was operated. Considering the early time at which this lathe was constructed, it shows a good deal of ingenuity and may well have been the forerunner of the developments in this line which came after it. It is a matter of record that in 1680 a mechanic by the name of Joseph Moxan built lathes in England and sold them to other mechanics, but we do not possess any certain or authentic knowledge of their design, as to whether or not screw threads could be cut with them or whether they were designed for work on wood or metals, or both. In all probability they were foot lathes and In the year 1772 the French encyclopedia contained the illustration of a lathe which was provided with a crude arrangement of a tool block or device for holding a lathe tool and adapting it to travel in line with the lathe centers. By this it would seem that the inventor had some idea of the slide rest as it was known at a later day by its invention in a practical form by John Maudsley in England, in the year 1794. Whether Maudsley had seen or heard of the invention shown in the French encyclopedia or not, it would seem fair to assume that he must have seen that or something akin to it, as the twenty-two years elapsing between the one date and the other must have served to make the earlier invention comparatively well known in the two nearby countries, both of which contained, even at this early day, many mechanics. It is interesting to observe that the slide rest invented by Maudsley over a hundred years ago has been so little changed by all the improvements since made in this class of machinery. There seems to have been an early rivalry between the French and English mechanics in the development of machines and methods for advancing the mechanic arts!" The next development of the screw-cutting idea seems to have been of French origin. In this lathe there was an arbor upon which threads of different pitches had been cut. These threads were on short sections of the arbor and by its use the different pitches required could be cut. While the exact manner of using this arbor was not described, its probable method of use will readily suggest itself to the mechanic, and was, no doubt, used at an earlier period, and in fact was what led up to the use of a lead screw or arbor with a multiplicity of different pitches. The principle is analogous to that used in the "Fox" brass finishing lathe so well known and extensively used, not only in finishing plain surfaces but in " chasing threads." This machine is shown in Fig. 10, which is a perspective view giving all the essential parts of the mechanism. The head-stock A and tail-stock B are of the usual form in use at the period, and were mounted upon the wooden bed C in the usual manner. The piece D to be threaded, and an equal length of lead screw or " master screw," as it was then called, were placed end to end in the lathe, the outer ends held in the lathe centers, and their inner ends, evidently fixed to each other by a clutch of some kind, were supported by a kind of center rest F. Fixed to the front of the bed C was a cast iron supporting bar G, of T-shaped section, extending nearly the entire length of the lathe bed. Upon the bar G, the top of which was of dovetail form, was fitted the carriage H, which was adapted to slide upon it and to support a thread-cutting tool J, and a tool or " leader" K, which fitted into the thread of the "master screw" E, and served the same purpose as the lead screw nut of the present day. Evidently the operation was that by revolving the piece D the "master screw" E was also rotated, and this rotation of the threaded screw, acting upon the "leader" K, forced the carriage H forward, causing the thread-cutting tool J to cut a thread upon the piece D, of a pitch equal to that upon the "master screw" E. It is probable that no better means of adjusting the thread-cutting tool J was provided than setting it in by light blows of the hammer. While the threads thus cut were probably rather poor specimens of mechanical work, they answered the requirements of the times, and as usual better means were devised for making them as the need of better and more accurate work created new demands and a higher standard of workmanship. threads had been cut with some sort of a " chaser," or tool with notches shaped to the form and pitch of the thread. These were very extensively used later and for many years in brass work, and the old-time machinist was very expert in their use. The sliderest, as we know it, while it relieved the workman from the fatigue of holding the tool firmly in his hands and depending entirely upon them for the position of the tool, with the exception of such support as the fixed rest gave him, was comparatively slow in coming into general use. While its usefulness must have been apparent to the average mechanic, the conservative ideas then in vogue must have retarded its prompt adoption, as they did many other meretorious inventions. By the use of the device shown in Fig, 10, it is plain that a different " master screw" was needed for each different pitch of thread to be cut, although the diameter of the work might be anything within the range of the lathe to hold and drive, so that provision was made for supporting the inner ends of the piece to be cut and the " master screw," and for driving the latter by the former. The idea of driving the "master screw " or lead screw at a different speed from that of the piece to be threaded had not yet been thought of, and it was years before this development took place. But before proceeding to this phase of the development of thread cutting, and consequently with the further development of the lathe, let us look a little farther into the methods of generating threads. That is, of producing the "master screw," from which other screws might be made. The author well remembers during his boyhood an old curiosity shop out in the country in which various kinds of hand machines were made and repaired. Among other things made were various appliances and devices for spinning woolen yarn and reeling it up into skeins of forty threads to a "knot," as it was called. To furnish an automatic counter for this reel a wormgear of forty teeth was used which engaged with a single threaded worm on the reel-shaft. Both the shaft having the worm formed upon it and the worm-wheel were of wood, usually oak or maple, and the thread was formed by wrapping a piece of paper around the turned shaft and cutting through this with a knife so as to make its length equal to the circumference of the shaft, its width representing the longitudinal distance on the shaft. This piece of paper was then divided into equal parts at each end and inclined lines drawn upon it as shown in Fig. 11, the divisions being equal to the pitch of the thread, found by spacing the circumference of the worm-gear blank for the forty teeth. The paper was then glued around the shaft and the diagonal lines gave the correct development of the screw thread, which was worked out with a fine saw, a chisel, or knife, and a triangular file. The teeth of the worm-gear were similarly cut to the proper V-shape, and the result was a perfectly practical and really workmanlike piece of mechanism that Thread be- answered the purpose remarkably well. same method of laying off screw threads was in practical use many years ago and was used by one Anthony Robinson in England as early as the year 1783, at which time it is recorded of him that he made a triple-threaded screw 6 inches in diameter and 7 feet 6 inches in length. It is said that he first laid off one thread by the method above described, leaving a sufficient space between the convolutions for the other two threads. This first thread was then worked out by hand with the time-honored hammer, chisel, and file, and he afterwards used this thread as a guide for making the other two by the same primitive means. In the light of the present facilities for cutting threads this process seems most tedious and laborious, and yet much of the machinist's work of that time was equally slow and must have sorely taxed the patience of the workman, whose principal and often only machine was a lathe of very crude design and workmanship, and in which he managed to do not only turning and boring but slotting, splining, milling, gear-cutting, and an endless variety of similar jobs, and in lieu of a planer having recourse to his ever ready cold chisel, hammer, and file, which with a straight-edge enabled him to make many a flat surface of remarkable nicety considering his limited facilities. And from these pioneer machinist's came the American machinist of to-day, the most thorough, best educated and expert mechanic the world has ever seen. It will doubtless have been noticed that in the earlier examples of the lathe, as in most of the machines in use, the framework of the machine in the lathe, the bed, and legs, were made of wood with the various metal parts secured to them. A good example tion of the lathes of the date when this one was built, is shown in front end elevation in Fig. 12, and in front elevation in Fig. 13. The history of this lathe is well known to the author, who was civil war. This lathe had, as will be seen by an inspection of the drawings, a bed composed of two timbers, placed at the proper distance apart and supported upon wooden legs, which in turn rested upon a cross timber supported by the floor. The timbers were of hard maple, those forming the bed being about 5 inches thick and 12 inches deep and were about 15 feet long. The lathe would swing about 32 inches over the bed. The patterns were made by Mr. Rea, the castings made in his foundry, and the machine work done in the nearby village of Plattsburgh. The "ways" or V's of the lathe were of wrought iron about f x3 inches let into a " rabbit" cut on the inside edges of the timbers forming the bed, and fastened by large wood screws. The top edges of these iron strips were chipped and filed to an angle of about 45 degrees to the sides, thus making the V an angle of about 90 degrees. The head-stock had cast in it square pockets in which the boxes for the main spindle were fitted by filing, and were held down by a rough wrought iron cap through which passed two threaded iron studs which had been cast into the metal. Upon these were two nuts as shown. The main spindle was of wrought iron and carried a wooden cone pulley built up on cast iron flanges keyed to the spindle. There were no back gears. front of the bed, one of which was pivoted to the front of the bed and the other capable of sliding vertically and therefore making provision for dropping this worm out of contact with the worm-gear when it was desired to " throw out the feed." To keep this feeding mechanism in gear a lever was pivoted upon the front side of the lathe bed, one end connected with the sliding box of the worm-gear shaft and the other hooked under a pin driven into the front of the lathe bed, as shown in the engraving. This worm-shaft was driven by a round leather belt working in one of the grooves of a three-step cone pulley fixed upon it, and extending up to a similar three-step cone pulley fixed upon the rear end of the main spindle. These pulleys were of hard wood and attached to cast iron flanges fixed in place. The belt was a " homemade" production but very much resembling the best twisted round leather belts of the present day, and was about three quarters of an inch in diameter. twenty inches in diameter. It will be noticed that no provisions was made in this lathe for cutting left-hand threads. It seems altogether probable that the use of left-hand threads began many years after right-hand threads were developed and used, as the need of them no doubt did not exist until the mechanical arts were much farther advanced and possibly not until they were wanted for producing a contrary motion in devices using the worm and worm gear. The tail-stock was of very simple construction, as will be seen in the engraving, the tail spindle having formed upon its rear end a downwardly projecting arm which embraced a screw tapped into the main casting and being provided with a crank by which it was operated. To bind the spindle in any desired position a ring was provided, through which the tail spindle passed, and to which was welded a bolt end passing up through the casting and being provided with a lever nut as shown. It will be noticed that by this construction the operation of binding or clamping the tail spindle tended to raise it out of its true bearing position and hold it suspended by this binder and its contact with the top surfaces of the holes through which it passed in the main casting. This continued to be the practice for clamping a tail spindle for many years before the present method of splitting the bearing at the front and fastening it by a clamping screw was first used. fitted upon it a curved forging, carrying a solid nut and capable of being attached to the carriage by two bolts when it was desired to cut threads. This forging was frequently called a " goose neck," from its peculiar curved shape. The thread of the lead screws was square and four threads to the inch. It was, of course, made of wrought iron, the use of steel for this purpose being of much later date. The method of driving the lead screws was characteristic and peculiar and is one of the main reasons for introducing this lathe to the attention of the readers of this book, as it marks one of the first known methods of changing the ratio of speed between the main spindle and the lead screw by means of gears of a varying number of teeth, which is here done in a very crude but comparatively effective manner. This method was as follows: Upon the rear end of the main spindle was fixed a flange having in its face a series of pins which formed the teeth of a " crown gear" and which engaged with a " Ian tern pinion" fixed upon an inclined shaft journaled in a bracket fixed to the lathe head and lining with the lead screw. This lantern pinion was made of two heads fitted upon the shaft and having pins running through the heads in a line parallel with the axis of the shaft, similar to the method seen in a brass clock. Upon the lead screw was a crown wheel similar to that upon the rear end of the main spindle, and whose pins, or teeth, engaged with those formed by the pins or rods in the lantern pinion upon the lower end of the inclined shaft. The fact that this lantern pinion was of much greater length than that on the upper end would seem to indicate that the designer or builder of the lathe had intended to use different sized wheels on the end of the lead screw for the purpose of producing different ratios between the speed of the lead screw and that of the main spindle, and therefore to cut threads of differing pitches. This seems to have been the earliest method of producing this result by a change of gearing, and probably antedated the method of using differing diameters of spur gears, as it is well known that the crown wheel or pin gear and lantern pinion were the oldest form of gearing, and in use in Egypt at a very early date, and that an imitation of our spur gear was made in a similar manner by inserting the pins in the periphery of the wheel instead of its face. The builder of the lathe in question probably borrowed his idea from some lathes very much older and which he had seen in his native country, as regular spur gearing for the same purpose had been used at a considerably earlier date than the building of his lathe, and as he was a man past middle life at that time. The lathe was built about 1830 and was in active service as late as 1875, although the lantern pinions and pin gears had been discarded and hung up on the walls of the old shop, and in their place were the usual spur gears, and a stud plate had been added for the purpose of carrying an idle gear so as to accommodate was originally built. The transition from wooden to iron beds and legs for lathes was probably made by the early builders of these machines about 1840 or a few years later. It is certain that in 1850 lathes with iron beds were made in New Haven, Conn., and that from this time on iron was universally used for this purpose. the lathes built by J. & S. W. Putnam, in Fitchburg, Mass., about the year 1836, or somewhat earlier, and shows in a remarkably sharp contrast with those of the present day when all possible devices are adopted for powerful drives, rapid change gear devices for both feeding and for thread cutting, to the common inch standard and those measured by the metric system; with micrometer gages and stops; with turrets located upon the bed or upon the carriage; and with all manner of attachments and accessories for doing a great and almost endless variety of extremely accurate work, as well as for turning out an immense quantity of it. One other example of the early lathes is shown that was in some respect somewhat ahead of its time, as will be pointed out. It is a 20-inch swing lathe built by A. M. Freeland, in New York City, in 1853. It is shown in Fig. 15. It is said that Mr. Freeland used English machines as his models and was an admirer of Whitworth and his ideals of what machine tools should be. In this lathe the flat-top bed is used as in many English and some very good American lathes at the present time. It will be noticed that the apron is in a somewhat abbreviated form, only sufficient to support its very simple operative mechanism. The carriage carried a cross-slide upon which were two tool-posts, one in front and one in the rear, which were connected by a right and left cross-feed screw, while there was a short supplemental screw for adjusting the back tool independently of the front one, and also a longitudinal screw for adjusting the tool lengthwise of the work being turned, so that the second or back tool would cut a portion of the feed, as the roughing cut and the front one take the remainder. It will be understood that the back tool is used upside down as in the modern lathes carrying the second tool. There was no rack and pinion arrangement for lateral hand feed for the carriage, the lead screw being used for this purpose by engaging with its thread a pinion fixed to the shaft operated by the crank at the right-hand end of the apron. It will be noticed that the driving-cone on the spindle has five steps, as in a modern lathe. The bed seems so light that it would now be called frail, in view of the present duty expected of a lathe of this swing, and in sharp contrast with the massive beds now used. In future chapters will be shown the modern American lathes with all their peculiar features illustrated, explained, and commented upon as this work progresses, taking up, not only the regular types of engine lathes, but also those of a more special nature such as turret lathes, pattern lathes, bench lathes, high-speed lathes, gap lathes, forming lathes, precision lathes, multiple spindle lathes, and so on, including lathes driven with belts from a countershaft in the usual manner, and also those driven by electric motors with the most modern appliances. In illustrating and describing these lathes much care has been exercised to have both the illustration and the description correct as to the facts shown and commented upon, and to this end the builders themselves have furnished the necessary facts so that the statements herein given are from proper authority and may be relied upon in considering the proper selection of the lathe best suited for the work for which it is to be purchased. CLASSIFICATION OF LATHES The essential elements of a lathe. The bed. The head-stock. The tailstock. The carriage. The apron. The turning and supporting rests. The countershaft, Taper attachments. Change-gears. Classification applied to materials, labor accounts, and the handling of parts in the manufacture of lathes. The four general classes of lathes. The eighteen sub-divisions of these classes. The first class: hand lathes, polishing lathes, pattern lathes, spinning lathes and chucking lathes. The second class: engine lathes without thread-cutting mechanism, Fox brass lathes, forge lathes, and roughing lathes. The third class: complete engine lathes with thread-cutting mechanism, precision lathes, rapid reduction lathes, and gap lathes. The fourth class : forming lathes, pulley lathes, shafting lathes, turret lathes and multiple spindle lathes. Rapid change gear devices. Bancroft and Sellers device. The Norton device. Lathe bed supports. The precision lathe. The rapid production lathe. The gap lathe. Special lathes. Forming lathes. Pulley lathes. Shafting lathes. Turret lathes. Screw machines. Multiple spindle lathes. Variety of special lathes. IN considering what are the essential elements of a lathe they may be briefly stated, if we assume that in a simple lathe the work is to be what was originally intended, that is, held on centers, and may be stated in these terms, viz. The essential elements of a simple metal turning lathe are : suitable means for supporting and holding the work upon centers; proper mechanism for rotating the work; and a cutting-tool properly held and supported upon a traveling device actuated by suitable mechanism. The first of these essentials comprise the bed, head-stock, and tail-stock, with their proper parts and appendages, so far as the fixed parts and centers are concerned, and including legs or other supports for the bed. The second essential comprises the driving mechanism, consisting of the driving-cone, back gearing, etc., and the third essential consisting of the carriage, tool block, and cuttingtool, with the necessary gearing for moving it, and the connecting spindle of the lathe. This classification of the essential elements of the lathe naturally suggests certain groups of related parts which compose a complete lathe, and correspond with the experience and practice of the author in the designing and construction of the various types of lathes. They are as follows : 1. Bed and appendages, including the legs or cabinets, leadscrew and its boxes, the feed-rod, its boxes and supports, carriage rack, tail-stock, moving rack (when the lathe is large enough to require one), stud-plate and studs, and such necessary bolt,s and screws as are needed to fasten these parts. 2. Head-stock and appendages, including such feed-gears as are necessary to connect with the feed-rod in case of a geared feed. Also the holding-down bolts and binders (if used), for fastening the head-stock to the bed, and the large and small face-plates. (Where a quick change gear device is used and is not an integral part of the bed or head it forms a separate class.) 3. Tail-stock and appendages, such as holding-down bolts, binders, and, when the lathe is large enough to require it, the mover bracket, gears, shafts and crank; and if the tail-spindle is handled by a hand-wheel in front, the brackets, shafts, spur and bevel gears, etc. 4. Carriage and appendages, including gibs and a solid tool block if one is used, but not a compound rest where these are furnished at the order of the purchaser. If the lathes are habitually built with compound rests they may be classed with the carriage. 5. Apron and appendages, including the apron in its complete assembled form ready to attach to the carriage, together with the screws for making such attachment. 6. Rests, including the compound rest (when not classed with the carriage, the full swing, pulley or wing rest (as it is variously named), center rest, back rest, (when one is furnished), together with bolts, binders, and similar means of attachment. 7. Countershaft and its appendages, including the hangers, boxes, shipper rod, etc., and any similar parts for tight and loose pulleys or friction pulleys as may be necessary to make it complete and ready to put up. similar parts are deemed extras and not included in regular lists. Change-gears are sometimes listed as a part of the bed and appendages. When these are a part of a special quick change device they are made a separate class. This is understood to be when the change gear device is detachable. When made a part of the head-stock or the bed such parts as are attached to the one or the other of these main parts will be listed with it and become a portion of its appendages. This classification is carried into all lists of materials of whatever kind and into all accounts of labor in the designing, constructing, and handling of these parts, whether in groups or as single pieces, during their progress through the various departments of the shop. The classification of these lathes as entire and complete machines, and according to their various types of design and construction and the uses to which they are to be put, will be next considered, and in so doing it seems appropriate to commence with the more simple forms, and to proceed with such types as are commonly recognized and in use at the present time, dividing them into four general classes and these into such sub-divisions as their construction and uses seem to demand By this method of classification we shall have: In the first class we understand by speed lathes a lathe without back gears and without the carriage and apron of an engine lathe, although as chucking lathes they may be provided with back gears, as they are frequently used for boring quite large holes, and are therefore made much larger and heavier than those of the other sub-divisions of this class. Hand lathes are supposed to be for the usual operations of hand tool turning, filing and light metal turning by means of a detachable slide-rest. They may have legs of sufficient height to support them from the floor as in Fig. 16, or with very short legs, making sometimes used upon them. Pattern lathes, as shown in Fig. 18, are usually so called when used by wood pattern-makers and while usually used with hand tools, as chisels and gouges with the support of a hand-rest, at the present time a majority of them are provided with a slide-rest. Those of larger swing have the rear end of the main spindle threaded for attaching a face-plate upon which is fixed large face-plate work of too great a diameter to be turned on the ordinary face-plate, as this supplemental face-plate overhangs the end of the bed and consequently the diameter of the work that can be turned is only limited by the height of the main spindle above the floor. In this class of work a hand-rest is supported by a tripod stand that may be moved to any desired position on the floor and is heavy enough to stand steadily wherever it may be placed. These tools form the metal in a manner similar to the action of a burnisher instead of cutting it, usually over a former, by which the same shape is produced in for large or special work. Chucking lathes, shown in Fig. 19, are used to a great extent for boring and reaming circular castings, as pulleys, gears, handwheels, balance-wheels, sleeves, bushings, flanges, and all similar work that require only the formation of the hole, although some of these machines are provided with a cross-slide and tool-post by means of which the hubs or bosses of the work may be faced. Many of them are now provided with a turret, by means of which several tools may be carried so that not only boring and reaming, but recessing, facing, etc., may also be done without removing the work from the chuck. These lathes usually have a very large driving-cone with a broad belt surface, or they are constructed with back gears similar to those in an engine lathe. It was from this form of lathe that the elaborate lathes built by Jones & Lamson and others of similar design and construction originated. In the second class we have what used to be called the " plain engine lathe," that is, one not provided with any thread-cutting mechanism. Formerly the smaller sizes of these lathes did not usually have the power cross-feed, although at the present time there are very few of them built by any of the manufacturers, unless by a special order, practically all the modern engine lathes having the thread-cutting mechanism, and frequently it is made an elaborate and expensive feature and covers a wide range of work. When these lathes were built to a considerable extent the feeding mechanism was nearly always driven by a belt, gears being very seldom used for this purpose. No sub-division has been here given for foot-power lathes, as any of those so far described can and have been operated by foot-power when not too large to be thus driven. The Fox brass lathe, Fig. 20, is built upon similar lines as the engine lathe without a carriage or apron, but in place of it there is a swinging tool post slide whose rear end is journaled upon a lead screw which gives a longitudinal feed when the slide is brought over to the front by means of a handle for that purpose. With this driver, straight turning, facing, and thread cutting is quickly and conveniently done. There is also a hand-rest and sometimes a cutting-slide or cross-slide. The tail spindle has a long run and is sometimes worked with a lever, particularly when chucking work is to be done. Occasionally the tail-stock is replaced by a turret carrying a variety of tools such as are convenient for the brass finisher. These lathes are usually made without back gears. They are run at very high speeds and in the hands of an expert brass finisher do the work very rapidly, both as to turning and boring or inside finishing, while they cut threads very rapidly by means of " chasers." Forge lathes are a very heavy design of the plain engine lathe, without thread-cutting mechanism (although some manufacturers add this feature so as, to make the lathes available as a complete engine lathe for much work that cannot be classed as forge work). The purpose of these lathes is to rough down large forgings, the users claiming that it is more economical to thus bring the work to the " forging sizes" than to do so by the process of hammer- ing, and that all the chips thus removed may be worked into other forgings by which this waste is economically recovered. It is therefore their practice to forge the work (cylindrical work, of course) to dimensions much over the forge sizes, and by the use of the heavy forge lathe to finish them to customers " rough turned" to within reasonable limits of " finish sizes." By the term " roughing lathe " we understand that the design is heavy and massive with a very powerful driving mechanism, lateral and cross feeds and a very rigid tool holding device. Such a lathe is seen in Fig. 21. While it is somewhat analogous to the forge lathe it is usually understood to be of much less capacity. And while the forge lathe, being for handling forgings almost exclusively, holds the work on centers, the roughing lathe should be made with a large hole in the spindle so that work may be "roughed out" from the bar as well as when held on centers, or with one end in a chuck and the other on a center. And here it encroaches upon what may be considered the field of the so-called " rapid reduction lathe " ; with this difference, however, that in the former lathe the work is simply roughed out, while in the latter it is supposed to be not only roughed out or rapidly reduced to near finished sizes, but in many cases entirely finished, or finished to dimensions suitable for being finished by grinding. a compound rest which in the larger sizes is capable of power feed at all angles. Such a lathe should also be supplied, especially in the larger sizes, with a tool-rest to attach to the front wing of the carriage on the left-hand side for turning the full swing of the lathe. The larger lathes, particularly those that are triple geared, should have a tail-stock arranged with two sets of holding-down bolts, by means of which one set may be loosened and the tail-stock set over for turning tapers without removing the work from the lathe, as the other set of bolts still holds the tail-stock to its place on the bed. There should also be a tail-stock moving device consisting of a rack attached to the bed, with which is engaged a 'pinion fixed to a shaft journaled in a bracket attached to the tail-stock base. By means of a crank on this shaft the tail-stock can be easily moved to any desired point upon the bed. In lathes of 42-inch swing and larger, this arrangement should be back-geared by the introduction of a second shaft, the gears being in ratio of 2 to 1. In lathes of 60-inch swing and larger this ratio should be 3 to 1. The tail-spindle in the smaller lathes has the usual screw and hand wheel for moving it back and forth. In large lathes this is inconvenient and laborious. The hand wheel should be placed in front of the tail-stock and near the center, being mounted upon a short shaft at right angles to the spindle and journaled in a bracket fixed to the tail-stock. Upon this short shaft is also a miter gear engaging with another fixed to a shaft parallel to the spindle and extending to the rear end of the tailstock where it passes through another bracket and has fixed upon it a spur pinion which engages a spur gear fixed to the tail-spindle screw, and by which mechanism it is operated. The ratio of this spur gear and pinion is usually 2 to 1 on lathes of 42-inch swing, and proportionately more on larger lathes. By the use of this mechanism the operator may stand opposite the tail center in adjusting his work and easily reach the hand wheel controlling the movement of the spindle, which would otherwise require an assistant to operate. In the triple-geared head-stocks of this class of lathes it is customary to attach the face-plate to the main spindle by a force-fit and key instead of making it readily removable by a coarse thread, for the reason that it is to be driven by means of a very large internal gear bolted to its rear side and engaged by a pinion fixed to a shaft driven by the cone through a suitable system of triple back gearing. In this case the cone is not placed upon the main spindle, but upon a separate shaft placed sometimes in front and sometimes in the rear of it. The front position is the more convenient for the operator in making the necessary changes of speed. It is upon this class of lathes that many improvements have been made in the last few years in the thread-cutting devices, the original idea having been to avoid removing and replacing " changegears" when threads of different pitches were required to be cut. The first attempt in this line, so far as the patenting of a device shows, was made by Edward Bancroft and William Sellers in 1854, and taken up by various inventors with more or less success but never brought prominently into the market until the patent was granted to Wendel P. Norton in 1892, when somewhat later on the mechanism was adopted by the Hendey Machine Company, since which time it has been manufactured with much success. In the meantime many other devices for the same purpose have been devised and built, so that now every tool room and nearly every machine shop making any pretense to modern equipment possesses lathes having some one of these " rapid change gear attachments " included in their design or arranged to be attached when desired by the customer. In the development of the engine lathe proper, much attention has been paid to the supports for the bed, and instead of the former pattern of light and, later on, heavy legs, substantial cabinets of liberal dimensions and weight, have been designed and are now used upon nearly all such lathes, the only exceptions seeming to be upon those where the selling price renders economy in the use of cast iron essential; upon lathes too small and light to justify their use; and upon lathes built by the more conservative manufacturers who have not yet come to consider this class of improvements as necessary to the efficiency of their machines. A precision lathe is designed to be a lathe in which fineness and exactness in all its parts is the prime consideration rather than a great range of work or capacity, or from which a large output may be realized. It is therefore not necessary that it should be very heavy or massive except in so far as its weight may render it capable of greater precision. While the entire design and construction of the lathe is as exact as possible, the effort is also made to provide against all conditions and causes that shall be detrimental to its one object, that of turning out its work in as perfect a manner as possible. These being the conditions under which it is designed and built, it is an expensive lathe, as the most skilful labor is used in its construction and the time devoted to this work is always liberal. It is, therefore, essentially a lathe for the tool room and the laboratory rather than the manufacturing department, and with it master screws of very great exactness and all similar work is performed. It is, of course, an engine lathe in its general design, although there are more or less changes of form and manner of assembling the parts introduced for the purpose of avoiding the effects of strains, protecting bearings from dirt, insuring accuracy of movement of the several parts, and so on, everything in the design and construction being subordinated to the one condition of the greatest precision and accuracy, not only in the entire machine but in all its individual parts. The rapid-reduction lathe, shown in Fig. 22, is another form of a complete engine lathe, built heavy and strong, with a powerful and somewhat complicated driving mechanism and very strong feed. The tool holding device should accommodate at least two tools and hold them very rigidly. It should have thread-cutting facilities so that pieces requiring threads may be entirely finished in this respect. It should be an accurately working machine so that it may not only rapidly reduce the stock to near the finishing dimensions, but finish all ordinary work to the given sizes, or to such dimensions as may be called for when the piece is to be finished by grinding. Such a lathe may be arranged with a series of stops both for diameters and lengths and thus do much of the work done in a very much more expensive turret lathe. It will be of much convenience to have a hollow spindle, bored out as large as possible so as to admit of running a bar of round stock through it, holding it in a chuck and forming one end of the pieces, then cutting them off, leaving the remainder of the work on the opposite end of the piece to be done at a second operation in this lathe or some similar machine. In working up round stock in this manner the lathe should be provided with a cutting-off slide constructed similar to that on a turret lathe. A gap lathe, shown in Fig. 23, is one in which the top of the bed is cut away for a space immediately in front of the face-plate for the purpose of increasing the swing of the lathe so that much larger work may be turned or bored, either when held upon centers or in a chuck. This type of lathe is more in favor in English machine shops than those of this country, where the gap lathe is seldom seen. When the work of the lathe is not of such a nature as to require the gap, it is usually closed up in one of two ways. The first method is to have a portion of bed exactly like the main part and of such a length that it will exactly fit in the space form- ing the "gap." The other method is to have that portion of the bed upon which the head-stock is attached, of the full height, while the remainder of the bed is lowered sufficiently to furnish a support for a sliding supplemental bed whose depth is equal to the depth of the gap. This supplemental bed when closed up to the face of the head-stock completes the bed by filling the entire cut-away portion completely to the rear end. When it is desired to form a /'gap" this supplemental bed is moved, toward the rear end of the bed proper to any desired distance to leave the required space or gap for the work in hand, and secured by bolts arranged for that purpose. In a large machine shop, with the proper lathes for handling whatever work the shop is called upon to do, the gap lathe is not usually necessary and will seldom be found, but in jobbing shops, particularly those with a modest equipment of tools, the gap lathe may often be found convenient for doing exceptionally large jobs such as pulleys, balance-wheels and the like, as these jobs may come along so seldom that it would not be advisable to incur the expense of a lathe large enough to swing them, and which would be liable to be idle a large portion of the time. The gap lathe is provided with the usual thread-cutting mechanism and is in all respects a complete engine lathe. It is not usually as rigid as a solid bed lathe and therefore not as efficient in taking heavy cuts. The fourth class, including the various types of special lathes, would of necessity be a very large one if an attempt were made to enumerate them all, and the list might prove tiresome to the busy reader. Those introduced in the foregoing list are of the well-known and recognized types and seem to be sufficient for the purposes of this work. Forming lathes are of heavy and massive design and construction, and provided with powerful driving mechanism, adapted to rather slow speeds, and with fine feeds, owing to the large extent of the cutting surface of the tools used in them. These tools require special forms of rest for supporting them which are of strong but simple design, as many of the forming tools are simply flat steel plates with the form to be turned cut in the edge, so that when dull they may be sharpened by grinding the top face and not changing the form. Forming lathes should have hollow spindles, bored out much larger in proportion than in other types of lathes. The author has designed and built these lathes of 28-inch swing with a spindle 7J inches in diameter and bored out to 5J inches, so as to take in a bar of 5-inch steel. As this size weighs about 85 pounds to the foot, or a bar 16 feet long weighs over 1 ,300 pounds, it will be seen that ample provision was needed for the weight to be borne upon the main spindle bearings in addition to the weight of the lathe parts, and that while the driving power necessary for operating with a wide forming tool on steel of 5 inches diameter was a serious matter, that of providing for the rotating of this unusual load was a considerable addition to it. However, they met the required conditions and succeeded in turning out much work even of this comparatively large diameter. Naturally the forming lathe requires no provision for thread cutting, but a geared feed should be used and will need to be of ample power to withstand the very severe strain to which it will be put. Pulley lathes, as they are commonly termed, might more appropriately be called pulley-turning machines, or even pulleymaking machines, since some of them make the pulley complete, with the exception of splining and drilling and tapping for the setscrews. In some of these machines the boring is going on and the reaming is also done while the turning is taking place. In other forms, one machine does the boring and reaming, which may be done at quite high relative speed, while the turning must be comparatively slower and is done in another machine. Thus one machine for boring and reaming may furnish work enough for several turning machines. In the pulley-turning lathes there must be a strong driving mechanism since comparatively large diameters are turned, although even the roughing cut is light when compared with that frequently taken by other lathes. Two and sometimes more tools are used, being located both at the front and back of the bed, (those at the back being bottom side up). In some machines the tools commence the operation in the center of the face of the pulley, and each tool or pair of tools (one roughing and one finishing), are fed away from the center, and with the slide upon which the tool block travels set in a slightly inclined position with reference to the axis of the lathe so as to produce the properly " crowned face" of the pulley. With four tools thus arranged, the pulley is completely turned during the time necessary for a tool to travel across one half of the face of the pulley plus the distance apart of the roughing and the finishing tool, say from an inch to an inch and a half. When the pulley-turning lathe is arranged for turning cone pulleys it is customary to have as many tools as there are steps to the cone pulley, each held in a separate tool post fixed in a single tool block having a lateral power feed and a transverse adjustment for setting to the proper diameter. The tool posts set in T-slots and the tools are set with relation to each other so as to turn the proper relative diameters of the several steps. The tool block and the slide upon which it runs is adjustable to the right inclination or "taper" to properly crown all the steps of the cone at once, and when the tools have passed over one half the face of the steps, this block and slide may be shifted and properly adjusted to turr the other half of each step. In this form of pulley turning it is usual to make two cuts, a roughing and a finishing cut, and when turning up to the face of the different steps to draw back the entire number of tools by means of the transverse slide which may be fed back by hand for that purpose. Pulley-turning and boring lathes or machines are built very broad as compared with an engine lathe and with very short beds, as the width of a pulley face, or the combined faces of the several steps of a cone pulley, is the extent of their lateral feed in any case. The boring and reaming mechanism should have a power feed so as not to require the constant attendance of the operator, who may easily run one boring and reaming machine and two surface turning machines. Shafting lathes or shaft-turning lathes may be arranged from any good engine lathe provided the bed is long enough for the purpose, by adding to it a three-tool shafting rest and a shaft straightener. Still a lathe that is especially designed as a shaftturning lathe will be better adapted for the purpose and will turn out more good shafting with the same expenditure of capital and labor than the engine lathe arranged with attachments for the purpose. In the properly designed shaft- turning lathe there is a heavy shaft running the length of the lathe bed and arranged to communicate power to a face gear and driver journaled on the front end of the tail-stock, by means of which the shaft to be turned may be driven from this end as well as from the head-stock end. This is very useful in turning long shafts in which the torsional strain would be great, as the power may be applied at the tail-stock to turn one half of the shaft and then applied direct from the head-stock, or it may be applied at both ends continuously and simultaneously. There should be a force pump to keep the cutting-tools constantly supplied with a stream of whatever lubricant is being used. This pump may be driven from the shaft above mentioned, which is located at the center of the bed and below the bridge of the carriage. The three-tool rest carries its own center rest, but it is customary to support the shaft being turned by easily removable rests used between the carriage and the head-stock or tail-stock, as the operator finds necessary. These are generally composed of two wooden blocks resting on the V's of the lathe and somewhat lower than the lathe centers. The upper block has a V-shaped groove for the shaft to rest in and is raised up and held in place by a wooden wedge inserted just far enough to give proper support to the shaft so as not to permit it to sag during the process of turning. There are three turning tools usually employed. The first is a roughing tool; the second cuts the shaft very closely to size, while the third takes an extremely light cut, completing the work, so that by running once over the shaft from end to end it is completely finished. Two tools are placed at the left of the center rest fixed to the tool block, and one, the final finishing tool, at the right. As these three tools and the center rest occupy considerable length upon the shaft the lathe is provided with extra long centers so as to reach the work. The center rest is provided with split collars bored to the size that the second tool leaves the shaft. The turret lathe, shown in Fig. 24, now so well and favorably known, is a comparatively recent invention and doubtless originated in the use of a multiple tail-stock which was formerly used on small work where more than one tool was desirable. Our English friends recognize its value and usefulness, and one author speaks of it as "the common capstan tool-rest." In this country much has been done to develop and bring into popular form the turret lathe by such builders as Jones & Lamson, Warner & Swasey, Potter & Johnson, Bullard and others. While the turret lathe in its perfected form is now a complete machine, the turret idea was first applied to engine lathes, and turret attachments are so universally popular that most of the lathe manufacturers now make them of dimensions suitable for their lathes, and attach them either to the lathe carriage or to a special bed which may be fastened to the lathe bed upon the removal of the tail-stock. A great variety of work may be done in the turret lathe, its principal rival being the automatic screw machine, whose economy lies principally in the fact that one operator may take care of a number of machines, each of these machines depending principally for their success upon the turret with its multiplicity of tools. And this idea of a turret carrying from four to eight tools is applied in a great variety of ways and to a large variety of machines on account of the ease with which any desired tool may be brought into a working position. The head-stock of a turret lathe is made in several ways, from that of a plain head without back gears to one with a large variety of speeds, controlled by handles operating clutches, or friction driving devices, or both, and which may be operated while the machine is in motion. In some cases the head-stock is cast in one piece with the bed, in others fitted to it in a similar manner to that of an ordinary lathe. In still others the head has a transverse movement on the bed upon which it slides and its movement is easily controlled by the operator. The turret is designed and constructed in a variety of forms, but principally either circular or hexagonal. It is mounted usually in a horizontal position, that is with its axis vertical, but still in some of the best machines, notably the Gisholt, it is pivoted in an inclined position, the object being to bring the long tools, made necessary by a large machine, up out of the way of the operator as they swing over the front of the machine. In the smaller hand machines and in many of the turrets furnished upon ordinary engine lathes the turrets are rotated by hand as each change is required, but in the larger and more complete machines the sliding movement of the turret effects its rotation at the proper time near its extreme rear position. A cutting-off slide carrying two tool-posts, one in front and one in the rear, serve to carry a cutting-off tool and a facing tool, or one for doing forming within certain limits. The spindle being hollow, and a large part of the work of the turret lathe adapted for steel work being made direct from the bar, these tools are very useful. Some turret lathes are particularly adapted for a large variety of chucking and forming work, which they perform very accurately and economically, an elaborate system of stops for the turret slide rendering them very efficient for this work. The tools that may be used in a turret are almost without number, and the expert operator readily attacks the most complicated pieces and brings them out with excellent finish and with surprising accuracy. Internal and external threads are readily cut very true to size and with rapidity. The screw machine is very closely allied to the turret lathe, so called, and the smaller sizes are fitted with what is called a "wire feed," which will automatically feed in the bar against the turret stop as soon as it is released by opening the chuck. This is in the hand screw machine. In the automatic screw machine all these movements are made automatically when once the machine is set up, the tools properly adjusted, the bar of stock once introduced and the machine started, and, barring accidents, the machine continues to run, dropping its work into a pan as it is completed and cut off, until the bar of stock is almost entirely used up. Multiple spindle lathes are usually those having two spindles. These may be side by side for the purpose of performing two similar operations simultaneously; or one spindle may be considerably higher than the other, above the bed, thus giving two different capacities as to the diameter of work that can be accommodated on the same lathe ; the larger swing being frequently used for boring or similar work. Notably of this type of lathe is that put in the market by J. J. McCabe. While the general and well-marked types of lathes have been specified in this classification it must not be understood that the list is complete, as there are many special lathes, each of excellent mechanism and well adapted to the special work for which it is designed, that do not appear here, and that it is manifestly impossible to classify and describe in detail. Frequently they may be assigned to some one of the classes or sub-divisions here set forth, as all lathes must partake in some respect of the essential parts of those described. Further on in this work many practical examples of the lathes described in this chapter will be found, their builders' names being given and their particular features pointed out and commented upon, and to them the reader is referred for the better examples of each of the classes enumerated in this chapter. LATHE DESIGN: THE BED AND ITS SUPPORTS The designer of lathes. The manufacturer's view of a lathe. The proper medium. Cause of failure. The visionary designer. Conscientious efforts to improve in design. Design of the lathe bed. Elementary design. Professor Sweet's observations. The parabolic form of lathe beds. The author's design. Form of the tracks. Bed of the old chain lathe. The English method of stating lathe capacity. Method of increasing the swing of the lathe. The Lodge & Shipley lathe bed. Uniform thickness of metal in beds. Ideal form of bed. Cross-ties, or bars. Four Vs. Flat surfaces. Lathe bed supports. Height of lathe centers. Wooden legs for lathe beds. An early form of braced, cast iron legs. Cabinets or cupboard bases. Old style cast iron legs still in use. Form of cabinets. Principles of the design of cabinets. Cabinets for small lathes. The Lodge & Shipley cabinet. The HendeyNorton cabinet. To the experienced and conscientious designer of machine tools the condition is frequently forced upon him that it is often easier, and usually far more agreeable, to design machines as he really believes they should be, than to design such machines as will meet the popular requirements of the market. He may be sure that a certain plan would make really a better and more efficient machine, yet he must, from the outset, consider the kind of a machine the customers want and will buy and pay for, since they are, as has been often said, "the court of final resort" in the matter, and machinetool builders manufacture machines to sell, and not for the purpose of exploiting individual opinions, however good they may be, or the fads and fancies of draftsmen who are sometimes imbued with visionary and impractical ideas. The manufacturer himself may be perfectly sure that the machines he is turning out are not the best adapted for the purposes for which they are used, or the best he could build for the money. He may so far have the courage of his convictions as to build for his own use machines quite different from those he manufactures for his customers. Yet for sale he must build what his customers want with small regard for his own personal opinions. By this it is not meant that the builder does not use his judgment in a mechanical way, or that he does not endeavor to build the best machines possible, inasmuch as he does give this very question much time, attention, and study. Yet he must, from the very nature of the case, always keep in mind the question, "What will the customers think of this new machine? " " Will this device be a success, or will it prove a failure?" Some machines that have been put on the market with feelings of much trepidation have proven great money-makers, while other machines possessing much mechanical excellence have fallen flat and a large majority of the customers refused to endorse them. The author has seen many such cases, and this has probably been the experience of every man who has designed and built machine tools. The proper medium in the matter seems to be to keep as closely in touch as possible with the purchasers of machinery; to ascertain their needs and preferences as closely as may be; to anticipate their wants when possible, but at the same time with conservatism; and to avoid putting entirely new devices on the market until they have been thoroughly tested in the home shop and by a few friendly shops outside of it. And by entirely new devices is meant substantially new and complete machines, as the builder will frequently have parts of, or attachments to, the regular line of machines that are made to the order of a particular customer and that he feels perfectly sure of being well suited to the work that it is expected to perform; yet in these cases considerable caution is necessary. The one fruitful source of difficulty, disappointment, and failure to be most avoided in the production of new devices is the mania often manifested by designers to produce something absolutely new, decidedly novel, the like of which no one has ever seen or dreamed of, and that will startle the mechanical world, revolutionize the business, and prove its author a veritable Napoleon of mechanical science. wiser course will be to abandon such ambitious attempts to eclipse all previous efforts, get down out of the clouds, design something of practical utility, even if it is not strikingly new; something that past experience gives some guarantee of success; something that will surely bring the proper financial return and be a credit to the shop. It is always well to remember, when tempted to go off on a tangent after something new and marvelous, that "a good adaptation is better than a poor original," and that when Solomon said that " there is no new thing under the sun," he did not come far from the truth, since many of the things we think are new may be found in almost the identical form, that have been invented, used, and discarded years ago, as the records of many mechanical libraries as well as the United States [Patent Office will furnish abundant evidence. By the foregoing remarks it is not intended to discourage originality, original thought and research, or the proper ambition to improvement, for we often produce more of real value by the effort to evolve mechanical improvements than by the design of entirely new machines, and the studious and observing designer will always be on the alert to devise improvements upon existing forms and processes. These observations and suggestions apply with as much force in the efforts to improve the lathe as any other machine in common use. Being the oldest machine in the machine shop does not in any respect limit the field for improvements in it. Neither does it preclude the design of entirely new machines that may have, perhaps, very little of the characteristics of a lathe, although we must necessarily be confined to the essentials heretofore discussed, namely, a bed, upon which rest the head-stock, tail-stock, and carriage, or their equivalents, if we would claim that our machine is a lathe. With these preliminary statements relative to the conditions and requirements of good and successful designing, we may take up the designing of lathes somewhat in detail and inquire into the design of the individual parts and groups of parts, giving some of the ideas of men prominent in this field, and adding such comments and suggestions as seem proper and pertinent to the case as the matter is proceeded with. In carrying out this plan it will be natural to commence with the bed, considering its use and purpose, and the proper form to fulfil the requirements of this particular part. The lathe bed, considered in an elementary way, and in the case of a lathe of moderate length, may be taken as a beam, supported at each end and in its turn supporting at one end the headstock, at the other end the tail-stock, and in the center the carriage, as represented in Fig. 25. This being the problem, and as the head-stock and the tailstock stand directly over the legs or supports, we might consider the problem as that of a beam loaded at the center, which would naturally suggest that the under side of the bed instead of being straight should be a parabolic curve. This would result in the form shown in Fig. 26, which would, if the carriage was stationary, conform to the conditions of the problem. But, while the carriage is not stationary, it is located at what would normally be the weakest point along the length of the bed, namely, a point farthest from either support. So far the parabolic curve, then, is correct. But while we have been placing our supports at the extreme end of the bed we have no condition of the case which makes it incumbent upon us to do so. In other words, we may add a portion to each end of the bed, outside of, or beyond the line of these supports, in the form shown in Fig. 27, showing a modified form of the lathe bed, the extensions at each end being in the form of a beam supported at one end. Theoretically, then, this would seem to be the proper form of a lathe bed in order that it might conform to the necessary requirements as to form and its ability to sustain the usual weights and strains to which it will be subjected, and at the same time not be of excessive weight, which would entail unnecessary expense. reference to machine beds. He says: "No reasoning can make it out that the place for the support of an ordinary sized lathe bed at the tail-stock end of the lathe is at the end. If placed a considerable distance from the end, and the tail-stock is at the end, it is better supported than when in the middle of the present style of lathes and also better supported at all other points. At the head-stock end it is quite a different matter as the head-stock is always fixed and is usually heavier loaded, exclusive of its own greater weight. Where the head-stock end support is a closet, there is no way to make it look right except to have the closet the same width as the head-stock is long. "In the case of a planing machine bed up to 12or 15 feet in length there is no reason for having three pairs of supports. Unless the foundation is absolutely unyielding — a thing that is more rare than the other kind — the three or more pairs of supports are especially bad, and to attempt to hold the foundation true with a frail planer bed is foolish. The distance between the supports in Fig. 28 is no greater than in 29, and as in no case would the center of the load in planing overhang the supports more than a slight distance the style shown in Fig. 28 is quite as well supported as the other; and when the iron in the legs and the work to fit them are taken into account, if they were all put into the casting the bed back of each housing and one under the middle toward the other end. The whole thing, including patterns and setting, will cost no (or very little) more and be four times better than present practice. "If the bed is supported at the same points when it is planed and fitted up, no attention or skill is required in the erection — just set it anywhere and on anything solid, and that is all that need be or can be done." There is "meat for reflection" in what Professor Sweet says (as there usually is), and the principle upon which he makes his deductions is undoubtedly correct. Fig. 31 the parabolic design is shown in proper proportion for supporting the head-stock, tail-stock, and carriage, and the proportions laid out are ample for all purposes, as is also the supports and their distance from each other. In Fig. 32 is shown a rectangular design of bed of like length and of sufficient depth to give the requisite strength, provided there is a central support added to prevent a sinking in the center of the bed, as the distance between supports would otherwise be too great. While nothing has been added to the strength or the stiffness of the bed, we have been obliged to add the central support and in addition to this the weight of the parabolic form of bed is 1,390 pounds, while the rectangular form is 1,550, a very material addition without compensating advantages; and at the same time we have the disadvantage referred to by Professor Sweet, that the nearer together we can get the supports and still retain the condition of rigidity the less we shall have to depend upon the correctness of the foundations, and this of itself is a matter of very important consideration, since in some of the popular forms of machines their truth and correctness depends to a very considerable extent upon the accuracy and continued stability of the foundations upon which they rest. It was from such considerations and conditions as has just been illustrated and described that the author designed and built the 21-inch swing engine lathe shown in Fig. 33. This lathe met with exceptional success in the market both in a mechanical and financial way and a large number of them were built and sold, although they were brought out during a season of great depression both in mechanical and financial circles, when hardly a machine Designed by the Author. shop in the country was running full time, and many of them but eight hours a day for three days only in a week. After a couple of years these beds were changed to the rectangular form in order to satisfy the demands of customers, the depth being nearly as great as the one here shown is in its deepest part, and the weight much increased. The ends were made square and the rear box leg made a regular cabinet similar to the front cabinet. The lathe is still built with very little change in its general design except as above specified, although it was originally designed over a dozen years ago. It will be noticed in the design shown in Fig. 33 that the front end of the front cabinet is in a vertical line with the front end of the head-stock, as suggested by Professor Sweet, and about twelve years before his article was published, although it is probable that he had held the same opinions therein expressed for a much longer period than this would indicate. There is much diversity of opinion as to the proper method of designing the "shears," "ways," "tracks," "V's" or by whatever term we may designate the top portion of a lathe bed. It has been shown in the "old chain lathe," Fig. 13, when beds were made of wood, that the V's were made of strips of wrought iron set on edge and fastened in rabbits cut in the wooden bed, their upper edges chipped and filed in the form of an inverted V. There were only two of these, the head-stock, tail-stock and carriage, all resting upon the same V's. Consequently, the carriage was not able to run past the head-stock or the tail-stock, as is the case with the modern lathe-bed having four V's. center or center of the head spindle B, should form an equilateral triangle. An arc C, of a radius struck from the center B, and just clearing the V at A, land. An English author, Mr. Joseph Horner, states it thus : "The 'centers' signifies the distance from the top face of the bed to the centers of the spindles. English and continental lathes are designated thus, but American by twice the centers, or the 'swing,' in other words — the maximum diameter which a lathe will carry over the bed." And with all due respect to the opinions and prac- tice of our cousins "on the other side/' it would seem the proper designation, and the one in which a prospective purchaser would be most interested, to tell him how large a piece of work could be done in the lathe, rather than to tell him the half of this diameter, or the radius, and let him have the trouble of the mental calculation of multiplying this dimension by two every time it is mentioned. It may seem all right when one is accustomed to it, but, like the English monetary system of pounds, shillings, and pence, it seems unnecessarily cumbersome when compared with the directness of the American expression. In order to increase the swing of the lathe without raising the head spindle in relation to the bed, some builders prefer to omit the inside V's, as shown in Fig. 35, by which means the arc C, as given in Fig. 34, and here shown as a dotted line, is increased to the arc D, and the swing of the lathe increased by twice this difference. In this case the headstock and the tail-stock are both fitted to the flat top of the bed and also have a projecting rib or its equivalent built down and years has been adopted by some lathe builders in this country. Still another method for increasing the swing is shown in Fig. 36. This is by lowering the inside V's, upon which the headstock and tail-stock rest, and leaving the outer V's supporting the carriage in their original position. In this engraving the arcs, representing the radius of the swing in the two former examples, are shown in dotted lines, and the increased arc E by a full line. There are other advantages in the form of construction shown in Figs. 35 and 36, which will be noticed later on. In Fig. 37 is shown the form of bed adapted by Lodge & Shipley, which will be seen to be a modification of the preceding examples in that, in this case, the English form of a flat surface is used in place of the front V, while at the rear the inverted V-shape is retained. There are several advantages in this form. The rear V is preferred by some as a better method of locating the headstock and tail-stock in perfect alignment, inasmuch as that while the head-stock, once located and securely bolted down, remains in its fixed position whether resting on V's or upon a flat surface and Form of Bed. between vertical faces as in the English lathe. With the movable tail-stock this is different. There is a constant tendency to wear in all directions of contact, and if fitted between vertical surfaces this tendency will in time throw it out of line. When resting upon the inclined surfaces of the inverted V, the wear is likely to be equal on the two sides and the lateral alignment is maintained, while the vertical wear will be considerably less than that of the head spindle in the boxes, which should be vertically adjustable to compensate for this wear and so a proper and perfect alignment of the two be maintained. examples, but corresponds very nearly to the proportions that have been found necessary to the proper strength and rigidity of the modern lathe when used under the severe strains and hard usage incident to modern shop methods and to the use of high-speed tool steels, with the necessity for the rapid reduction of the diameter of the stock which would in former times have been considered very wasteful of materials, but which in these days of cheap machine steel are much more economical than the usual processes of forging the parts to nearly the diameters necessary, as was formerly the usage when the price of steel was very much above what it is now and the cost of labor considerably less. It will have been noticed in the engravings of the cross sections or beds thus far given, that the "side plates" or outer walls have been uniform on the two sides and across the ends. Also, that the bed is very much strengthened by the track or flat upper member. To obtain a casting of nearly uniform shrinkage throughout, and to diminish as much as may be the unequal strains, as well as to ing great strength and stiffness with a minimum amount of material when its rigidity is considered. Much is said in machine tool design of the "box form," and while in some instances its merits may have been overrated it certainly is a form possessing most excellent qualities of strength, stiffness, and power to withstand torsional strains as well as to rigidly support heavy loads. It is for these reasons that this bed is designed as it is, and for these reasons it seems fair to call it an ideal form. The entire length of the sides or " side plates," are double, or of the "box form," tied together at frequent intervals so that the outer and inner wall properly support each other. To " balance the casting," there is not only an additional thickness of metal at the bottom of the outer wall, on the outside, but an inwardly projecting flange along the inside of the inside wall at the bottom. As far as possible the casting and all its component parts are of as nearly as may be the same thickness, so as to reduce to a minimum the internal strains of the casting as it cools after being "poured." shown, in addition to the front elevations and the various forms of beds for supporting the weight of the head-stock, the tail-stock, and the carriage. The next feature to be considered will be the "cross-bars," or "cross-ties" as they are sometimes called. The cross sections of these various forms are shown in Fig. 39 at A, B, C, D, and E, which give the principal forms in common use. At A is the simple form or single bar, set on edge and used in the earlier forms of cast iron lathe beds for many years. The desire to get some form more rigid laterally led to the addition of a horizontal rib, first on the top edge only and then on the bottom also, making the I-beam section shown at B. This was for many years considered quite sufficient for the purpose until the desire for more strength and stiffness led to the adoption of the "box form" shown at C. Later on this form was still further strengthened by the addition of outwardly projecting ribs or flanges at the bottom edges forming the section that is shown at D. To this form has since been added the top ribs as shown at E, and the question has, for the time at least, been solved, of making as strong and rigid a cross-bar as is possible. It will be noticed that wherever these forms are with double walls the internal space is closed at the top. This occurs, first, as the bed is cast bottom side up, and it is more convenient to pour the molten iron into this form and have a solid casting; it gives a better appearance to the top of the cross-bar in the finished lathe; and a cross-bar open at the top would furnish a receptacle for dirt, chips, and small articles that would occasionally drop into it. the earlier forms of beds being two or three times the width of the center of the bed. This distance was gradually reduced as the beds were made heavier and stronger, until ten or fifteen years ago it was frequently the case that the cross-braces were spaced considerably less distance apart than the width of the bed, particularly in the wider beds used for heavy lathes, say from 36-inch swing and larger. This method of locating them prevailed in the use of the forms shown in cross section at A, B, and C, Fig. 39. As still stronger and more rigid beds were called for, the braces were placed at an angle, generally crossing each other, and of the form and proportion shown in plan in Fig. 41. In this case it was usual to use the forms shown in cross section at B, C and D, Fig. 39. The angle at which these were set was varied by different builders, that here shown being 45 degrees, and the most usual angle used. sectional form shown in Fig. 39, at E, and are placed at an angle of 30 degrees with the side of the bed, and in the illustration the spaces between the walls of the braces as well as the bed are shown, and also the proper spacing from the head end of the bed. It will be readily seen that such a form of casting insures great stiffness and rigidity and guarantees the casting against torsional strains, as well as against unequal strains as the casting is cooling. As a matter of design in providing a rigid bed this form seems to realize all the desirable qualities that leave nothing more to be desired. Yet it is possible that in the continual development of the lathe, better methods and stronger beds will be brought out, for what we consider to be of ample strength to-day may be relegated to the scrap-heap a dozen years- from now. The form of the " track" or upper portion of the lathe bed has much to do with the form and strength of the carriage which it supports. In the early form of wooden beds, with two V's formed from wrought iron bars set upon edge and chipped and filed to the inverted V form, with the head-stock, tail-stock, and carriage all resting upon them, the carriage had, of necessity, to be made with scant bearing on the V's, that is, very narrow, measured along the length of the bed, as it could not pass the head-stock and the tail-stock as the "wings" of the carriage do in the later forms of bed with four V's, or their equivalent. Consequently, the head center of the lathe had considerably more " overhang" than it has at present, in order to permit the tool to be worked up near the lathe center; and the same was true of working up closely to the tail-stock center. With the advent of cast iron beds four V's were usually provided for. Whether the idea of four V's came in with the cast iron bed is not certain, as it is entirely possible that some ingenious machinist fitted the wrought iron strips, not only to the inside but to the outside of the two wooden beams composing the bed, and so The lathe bed with four V's and the carriage suitable for it is shown in Fig. 43, by which it will be seen that the portion of the carriage coming over the inside V's at A must be cut away so as to clear them entirely, as the carriage must rest wholly upon the outer V's. The necessity for this cutting away to clear the inside V's is a source of weakness to the carriage, and the only way to compensate for it is to make this part of the carriage broader, which does not add much to its strength, or to make it deeper, which lessens the capacity of the lathe by decreasing its possible "swing over the carriage." In Fig. 44 is shown the effect when the inside V's are omitted, and the carriage at A may be made of much greater strength without raising its top line so as to decrease the swing over the carriage. It is clear that so far as the convenience of design and the strength of the carriage is concerned this form of bed is preferable to the one having four Vs. There is one disadvantage, however, which occurs in fitting the head-stock and the tail-stock to this vertical inner surface of the " track" at B, B. The head-stock, being fixed to the bed, may be tightly fitted and remain so, but the tail-stock, from its being a movable part and frequently run back and forth, will in time wear sufficiently to throw its center out of line with the center of the head spindle. This disadvantage may be obviated by making these vertical surfaces B, B, slightly inclined. This inclination to the inner surfaces of the track of the bed is shown in Fig. 45, which gives the form of a carriage when designed to fit the ideal form of bed shown in Figs. 38 and 42. In this case the full strength of the carriage is maintained and a second support is furnished it inside of the outer V at the front and back by the contact of flat, horizontal surfaces in the place where the inside V would be in the form of bed having four V's. This construction shortens very much the "span" of the carriage between supports and consequently renders it much more stiff and rigid, adapting it to much more severe strains in heavy work than either style of carriage preceding it. In fact it is the strongest carriage now known, in proportion to its weight. The form and proportions of the lathe bed having been duly considered, its different component parts illustrated and described, and these detail matters criticised and commented upon, the next part of the lathe to be dealt with would naturally seem to be the legs, cabinets, or like supports upon which the bed is to rest. The usual height of the centers of a lathe from the floor is about 43 inches, and in designing lathes this height is maintained without regard to the capacity or swing of the lathe until its swing becomes so large that with the bed resting on a properly built foundation on a level with the floor, it becomes necessary to raise this height be the legs or other supports under the bed. In the early style of wooden beds, these supports were simply legs of square timber bolted to the bed and either vertical or spread out at the floor, according to the notion of the builder. When cast iron beds came to be used the legs were also of cast iron and of rather frail design. Later, when the necessity for more rigidity was found desirable, not only the beds but their supporting legs were made heavier. In a shop near Boston was found a lathe provided with an example of the earlier form of cast iron legs strengthened by cast iron braces as shown at A, A, A, A, Fig. 46. The lathe was 12-inch swing and of the hand lathe pattern, with a wooden cone pulley on the spindle, probably built about 1840. The legs were quite light, the different members being about j inch thick and 2 inches wide. The braces were of the same dimensions and secured at the ends by J-inch "tap bolts" of the old square-head style, the ends of the braces being thickened somewhat to accommodate them. How this lathe happened to endure the wear and tear of shop use for so many years without the legs being broken is a mystery. Their frail and slender appearance beside the modern deep bed, supported by heavy cabinet legs, is an object lesson in the practical evolution of the American lathe. With the continually increasing weight and rigidity of the lathe beds to meet the hard service of modern shop methods and highspeed steels, first represented by the Mushet tool steel, it became necessary to furnish much better supports for the lathe beds, and the fact was apparent that these supports must extend for a greater distance along the length of the bed than the older form of legs ever had. At this time there were several of the different machine tools supported on a " cupboard base," or a base of rectangular formhaving a door giving access to its interior for the purpose of stowing away tools, change-gears, wrenches, and like articles. This form of base was prominently used in the Universal Milling Machine. Whether the " cabinets" for supporting a lathe bed were suggested by this use of them or not does not appear, although it seems probable. We know that wooden cupboards had been used under lathes, being fastened to the legs and used for the same purposes as the cabinets or cupboards formed in the bases or, as sometimes called, the " standards" or columns of the later machines. At the present time a number of lathe builders still use the oldstyle legs, made heavier and with the material better distributed for strength, and, as a rule, the top portion of the leg extending farther along on the under side of the bed for the purpose of giving better support. It is also the case that the cabinet form of bed supports is used more upon expensive lathes, such, for instance, as those designed more particularly for tool room and precision work. For turret lathes and screw machines they are also much used, and are often cast as an integral portion of the bed itself instead of being made as a separate piece and bolted on. Cabinet supports for lathe beds are made in various forms by the several builders, some of which will be illustrated in this chapter. These will be such as have some general features common to nearly all of them, and in addition a few of the forms having special features. The correct principle governing the dimensions of cabinet supports should be properly understood. Obviously, the reasons for substituting cabinets for the earlier form of legs was to obtain a better support. It was certainly possible to so design the leg as to amply support the weight of the lathe and all that could be put upon it by way of work to be done by it. The disadvantage was that a leg placed at each end of the bed and extending only a short distance along under it left a long stretch of bed with no support at all. This necessitated " center legs " and, in a long lathe, two or three of them. Under these conditions it was a difficult matter to so set up a lathe that these center legs should all sit level and support the bed in a correct, level, straight line. These difficulties are in a great measure avoided in the lathes provided with cabinet supports. In Fig. 47 the effect of the oldstyle legs is seen. Attention is called to the fact that the headstock is only supported by the leg at the outer end, while the point at the front journal where the heaviest weight comes has no support whatever from the leg. The same may be said in a lesser degree of the rear end, where the tail-stock has only partial support in a similar manner. And when the tail-stock is moved out of its extreme rear position the case is much worse and identical with that of the head-stock. This condition will, of course, necessitate the use of a center leg, which if not supported upon the floor or foundation in a perfectly correct position will do as much harm as good. If it is too low it will be of no benefit since the center of the bed may sink under the weight, and strain of the work upon the carriage. If it is too high the lathe will be thrown out of line. In sharp contrast to these conditions is the bed shown in Fig. 48. In this case the front cabinet is of a length on the bed equal to the length of the head-stock, hence the front bearing of the head spindle has a support of solid iron down to the foundation, or floor upon which the cabinet supports rest. The tail-stock is similarly supported by a cabinet occupying the distance equal to its length upon the bed. An argument in favor of this method of supporting the bed is not necessary as the conditions are self-evident. But there is still another reason why the cabinet support is the more rigid, and that is the fact that with the long distance on the bed to which the cabinet is firmly and solidly bolted comes additional stiffness and rigidity, not only in a vertical direction for sustaining weights, but also to withstand the torsional strains to which every lathe bed is subjected, and which are multiplied rapidly as we load the lathe with heavier work, take heavier cuts, and use high-speed tool steel, by which much greater speed may be used. The next matter to be considered is the form of the cabinet, although this is a secondary consideration, the first being that we have the cabinet and that it reaches out under the bed to the practical length as shown in Fig. 48. For small lathes, say from 12 to 20-inch swing, the cabinet is frequently made nearly square While this is wrong in theory, as has just been explained, it is an improvement upon the old-style leg. The form shown in Fig. 48 is substantially that used by Lodge & Shipley in their smaller lathe. Its peculiar feature is the strength, vertical end walls, without projections at the base, while the regular projection is made in the front and the rear. This form is less expensive in its pattern work and somewhat easier to mold, but its appearance is not as good as the one shown in Fig. 50 Small Lathe Cabinet. which has equal projections on all four sides and at the top and bottom, thus giving it a more symmetrical appearance. It may have only three sides enclosed, the side walls turning the corner for only an inch or so, and this side be placed underneath the lathe bed, as is now done by some of the builders. But as this cut-away portion would come directly under that point of the head-stock where the most support is needed, it is of doubtful utility to cut it away, or to reduce the support of solid iron at this point. Lathes for light work, of 12 to 18-inch swing, may be supported by square cabinets, but if for heavy duty and continuous hard work the cabinets should be considerably longer than they are wide and support the bed as shown in Fig. 47. and Cupboard," for medium-sized lathes, say from 20 to 28-inch swing. These answer the conditions as represented in Fig. 48, and are not excessively expensive. They also furnish one closed cabinet and an open cupboard, both of which are available for storing tools, gears, and similar articles. The arched opening at A affords a for Large Lathes. convenient space for introducing a lever or bar for the purpose of moving the lathe. This arch should be placed in the cabinets of all but the smallest ones, and even in them a small arch suitable for the use of a crowbar will be found convenient. In either of the styles of cabinets shown the shelves may be cast in, but the usual method is to cast strips upon which the ends of wooden shelves may rest, thus making not only the pattern work but the foundry work more simple and economical. its superstructure. In Fig. 53 is shown a similar cabinet used by the Hendey-Norton Company, differing from the last one in having the inner end cut away. This cabinet does not, of course, admit of the introduction of shelves. In the larger lathe, say from 30 to 40-inch swing, inclusive, doors are not usually provided, as the height does not admit of it. Above 40-inch swing the bed usually rests directly upon the foundation. The cabinets here shown are given simply as examples, but they give a good idea of the forms used by most of the modern lathe builders at the present time, and the reasons for their continued and enlarged use. It is altogether probable that the future will witness an increase rather than a decrease in the use of the cabinet for supporting machines of all kinds where it is possible to introduce them, on account of their great rigidity in proportion to the weight of cast iron used, as well as the fact that they furnish a safe and convenient receptacle for tools. SPINDLE CONE Design of head-stock for wooden bed lathes. Early design for use on a cast iron bed. An old New Haven head-stock. The arch form of the bottom plate. Providing for reversing gears. The Hendey-Norton head-stock. The Schumacher & Boye head-stock. The Le Blond head-stock. The New Haven head-stock. The arch tie brace of the new Hendey-Norton design. Generalities in describing a lathe spindle. Designing a spindle. Governing conditions. The nose of the spindle. Spindle collars. Proper proportions for lathe spindles. Large versus long bearings. Design of the spindle cone. THE subject of lathe design is continued by the consideration of the design and construction of the head-stock, which in some respects is the most important part, and with it and the parts which go to make up the complete head-stock, the most important group of parts in the lathe. In the earlier form of lathes this piece was, like most of the other parts, simple and crude in design as well as in the workmanship bestowed upon it. It generally consisted of a base and the two upright ends in which provision was made to receive the boxes, and when wooden beds were thought sufficient for a lathe a strip was added beneath that filled the space between the two timbers forming the bed. Such a design for a head-stock is shown in Fig. 54, which is taken from an old lathe that did many years' service in a general repair shop. It will be noticed that the housing for the spindle boxes do not have square edges, but are of V-shaped form. They were finished with a file only and the boxes made of cast iron, filed to a fit and lined with babbitt metal which was said to have been poured around the lathe spindle after it was finished, set in place, and lined up as well as might be with the crude appliances at hand. The top portion of the boxes were held down by a straight bar cap with two holes which fitted over fixed threaded studs that had been cast into the head-stock for this purpose. The lathe was devoid of a back gear and the spindle carried a three-step cone, the largest part of which was as large as was possible to get into the head, and a belt quite wide, considering the power then thought necessary to drive a lathe carrying the diminutive chip which was considered proper for a lathe to take at the time this lathe was in use. Later on, when the cast iron bed was adopted and when back gears were added to the lathe, the requirements of additional strength were recognized and not only the base plate, but the up- Lathe Bed. rights or housings at the front and rear end, were made thicker and heavier. One of these head-stocks is shown in Fig. 55, which gives a good general idea of the form of the casting and shows also a strengthening brace A. While it would seem at first thought more necessary to brace the housing of the front box than that carrying the rear journal, it should be remembered that the latter must withstand the strain of the " thrust" or endwise pressure of the spindle due to holding work upon centers, and the pressure of drilling work, one end of which is held in a chuck and the other in a center rest, and similar kinds of work. While in the modern lathes this thrust device is usually a part of the rear box, the earlier method was to fix two studs in the rear of the head-stock, one in each side of the rear box and on a horizontal line with it, and across these to fix a strong bar carrying an adjustable thrust screw for taking the end thrust of the spindle. The details and design of this important device will be taken up further on. Gears and a Strengthening Brace. In Fig. 56 is shown a peculiar form of head-stock upon an old lathe in one of the older shops in New Haven, Conn. The lathe was broken up for old iron after an indefinite period of idleness. It was of about 16-inch swing and the various members of the headstock were about one and one-half inches square. The bed of the lathe, and the legs which supported it, were of cast iron and very much like those shown in Fig. 46. The head was provided with back gears of very light design and the lathe had a lead screw and the base of the casting was raised in arch-like form and the under side recessed to the same form so as to maintain an equal thickness of metal throughout. This form seems to have been a favorite one and many lathes were built by various makers with substantially this form, the variations from it not being of sufficient importance to justify a further classification. As yet the housings had not been made thick enough to suggest coring them out in order to save iron or for the purpose of avoiding unequal contraction of the metal upon cooling after casting, by making all members of the casting of as nearly an equal thickness as possible. Of late years these points have received much attention and study by the designers of machine tools, and rightly so, as their importance was to a large extent overlooked in the earlier designs, the reason probably being that all castings were made so much lighter and had much less strain to withstand in the regular service to which the machine was put. In Fig. 58 is shown a modification of the arch form shown in Fig. 57, which has for its purpose the strengthening obtained by the rib A in Fig. 55, only in a better form, as the method is " cored out," or formed with a " green sand core" under the head-stock, so as to provide for an equal thickness of metal over the entire base. This raised portion could be introduced quite conveniently as the small end of the spindle cone was located over it, thus insuring ample space for building it up. were located outside the housings, except in the case of that shown in Fig. 56. As the change came to be made of locating " tumbler gears," or reversing gears, inside of the housing, it naturally followed that the metal of the head-stock base must be cut away under that part of the main spindle upon which was fixed the spindle gear or feed gear from which the feed mechanism was driven. This was the case for perhaps fifty years, and at the present time, now that reversing devices are constructed as a part of the apron mechanism, the feed gears may be placed outside of the housing, although some good builders still keep it inside and connected in practically "the same old way," even if the "yoke gears" or reversing gears are omitted. When reversing gears were thought necessary to be upon the inside of the housing, a hole was cut out for them in the raised arch A, Fig. 58, and this practice was followed in any head-stock having this or a similar obstruction to these gears, and provided, of course, that they were to be located inside of the rear housing. One of the recent modifications of the above form is that shown in Fig. 59, which is a type of the Hendey-Norton manufacture. The central figure is a front elevation with the sectional form indicated by dotted lines. The figure at the left is a rear end elevation with the internal form on the line A, A, of the central figure, while the figure on the right is a similar elevation of the front end with dotted lines showing the section on the line B, B. the line B, B, is of an inverted arch, or as frequently called by the shop men a "pig trough" shape. This latter form enab'es the metal to be carried higher up at the front and back while the center is depressed to give proper clearance for the larger steps of the cone and the face gear. At the lowest part of this depression there is usually an opening through which oil may drip so as not to collect inconveniently at this point. The arch-like form near the rear housing adds very much to the strength and rigidity of the casting. It will be noticed that in this design the main spindle boxes are not " capped in," that is, held down by removable caps. More will be said of this peculiarity in describing boxes and spindles. The cores beneath the base are carried up into the housings in many of the modern head-stocks as far as possible, and still leave ample support for the boxes and spindles. The advisability of this method of lightening the weight of the casting is still an open question among machine tool designers who have endeavored to avoid unequal strains in the shrinkage of castings by making all members of as nearly equal thickness as possible. Sometimes this idea is carried too far and the result is liable to be that of sacrificing the necessary rigidity to prevent vibration, in the effort to follow out the ideal as to strains. Fig. 60 shows a head-stock in which the inverted arch form is continued the entire length between the housings, but is carried upon a curved line as shown and forms a very graceful curve. The three figures are arranged the same as those comprising Fig. 59. The height of the curve might be greater at the line A, A, as will be shown in some others further on in this chapter, and the strength of the casting considerably increased. This form is used with few modifications to adapt it to the diameters of driving-cones, the nature of the back gears and the feed gears and similar conditions that tend to somewhat alter the construction outlines of its design. This form seems to be a favorite one with designers, since among all the different builders and the variety of designs there are more builders using this form than all the others put together. While the above form of design carries a reversed curve for the top of the base, the form used by Shumacher and Boye, shown in Fig. 61, is of a single curve from rear to front housing and the inverted arch in its transverse sectional form. In this design the front and back is carried high up near the rear housing and comparatively low down near the front housing. This is a design of much strength and rigidity in proportion to the weight of the casting, the metal being well distributed to resist heavy strains in the operation of the lathe. The Le Blond type is shown in Fig. 62. In this we have a straight line at the back and front, with a modification of the reversed curve and the combination of the arch proper and the inverted arch as shown in Fig. 59. The form is pleasing to the eye, and the strength of the casting is quite sufficient for the requirements. In this case the housings are made of ample width, especially the front one. They are cored out inside so as to have substantially an equal thickness of metal at nearly all parts. The New Haven type of head-stock is shown in Fig. 63. In this case the inverted arch is used all the way through, but it is upon straight lines, that form a cross section at A, A, continuing straight and on a proper incline to a point near the line B, B, from whence it is horizontal. This design gives great strength, and with the proper proportions and thickness of metal throughout it is as rigid as it is possible to design a head-stock. The housings are unusually thick and cored out underneath as shown by dotted lines. tically the same as that shown in Fig. 59, except for the arched brace C, from the front to the rear housing, effectually tying them together and thus adding considerably to the rigidity of the spindle-bearing boxes, which is always an excellent point to be considered. a separate cap. While this idea is now quite common in the design of milling machines, it has not been applied to the head-stocks of lathes by any builders but these so far as is known. There are many classes of work in which a head-stock so braced would be very valuable, as its strength and rigidity is much increased by it and the strain and vibration is considerably reduced, which has the effect of increasing the efficiency and also the life of the cutting-tools. This question of increased rigidity and the importance of obtaining it has received much attention in the past few years, and the result has been the constant increase in the pro- portions and the weights of all parts of metal-working machinery which form the supports of cutting-tools or their intermediary parts. It is altogether probable that in this increase in weight the limit has not been reached, but that it will continue in years to come, although not perhaps in the same proportion that it has during the last decade. The use of high-speed steel will, doubtless, be extended to other uses than at present, and its price will be materially reduced, thus increasing the amount used and consequently demanding stronger machines and more power to drive them, so as to continually reduce the cost of the product by reducing the time of machine operations. Having designed a good head-stock with ample proportions in general, the metal so distributed as to withstand not only the strains to which it will be subjected in performing its appointed functions, but with proper considerations for the changes which will take place in the process of casting and cooling, and not forgetting that castings will change their form more or less for weeks after being cast, our next concern will be the spindle. It is not enough to say, as catalogues sometimes do, that "the spindle is of hammered crucible steel of large diameter and runs in hard bronze boxes." This may all be relatively true and yet it may be neither properly designed or properly constructed for the uses to which it is to be put. To design a lathe spindle we must consider the work it has to do, the points at which it will be supported, the points where it must support the material that is to be machined, and the parts with Front Bearing. which it is loaded and which become a part of its attendant mechanism ; not only these points, but others that are equally important,— the torsional strains to which it will be subjected in performing its regular functions, and which include that of driving the piece to be turned, of the strains of the cone when driving direct, or the back gears or triple gears when they are in action, and of the feeding mechanism which derives its motion from the rear end of the spindle. If we are to consider principally the weight of the face-plate and the material to be turned, which falls almost entirely upon the front journal, we should have the form of the lathe spindle as represented in Fig. 65. In this case the front bearing would necessarily be very large and strong and with ample support. The rear bearing need not be a matter of serious consideration, as it is quite a distance from the front bearing, while the weight of the face-plate or chuck carrying the work, or the center which supports one end of the work, if supported by this means, carries nearly all the strain. Therefore the rear bearing may be small and short as shown. Again, if the weight of the cone and its parts are to be principally considered, we should have a spindle more nearly conforming to the outline shown in Fig. 66, the rear bearing being larger and the front bearing smaller than is shown in Fig. 65. This would also be the case if the upward pull of the belt were a governing factor in determining the form and proportion of the spindle. But the fact is that the cone and its action upon the spindle, so far as its weight or the belt pull upon the spindle, while in reality a factor is given to Cone Pulley. to be considered, as will be referred to later on, is not the prime factor by any means. Therefore we must recur to the form shown in Fig. 65 for the points necessary for the proper consideration of forms, the determination of the contour, and the proper proportions of the lathe spindle. This view of the case leads us to the choice of a medium between the two extremes presented and an ideal form as shown in Fig. 67, wherein the conditions governing both the former examples are properly considered and met. There is one more condition to be considered, however. This is the upward or lifting tendency supposed to exist by reason of the cutting-tool forming a fulcrum, which, in connection with the circular motion of the piece being turned, tends to lift the spindle in the front box and so throws an upward strain on the cap over the front journal. This tendency is represented in Fig. 68, wherein the arrow shows the direction of the belt and revolution of the material being turned. It is doubtful, however, if this point is of much importance, particularly in a lathe properly designed as to the dimensions and weights of its parts, especially of the spindle and its appendages. Taking all these matters into consideration we shall find that the proper proportion and design of the spindle with the face gear, cone pinion, and the feed gear, will be substantially as shown in Fig. 68, leaving out of the design for the time being the special As the purpose of the thread is simply to prevent the plate from coming off the spindle, it naturally follows that the length of this thread may be very much reduced without in any way reducing its capacity to securely hold the plate in place. It is also quite as evident that we can hold the plate perfectly true in its place and exactly concentric with the front bearing if we grind a portion of the nose of the spindle to a truly cylindrical form when we grind the front bearing and then fit a sufficient portion of the bore in the plate to this ground surface. This may be accomplished by threading the nose of the spindle through only one third of its length, and grinding the remaining two thirds to which the chuck-plate or face-plate is fitted. This centers the plate accurately with the axis of the spindle. If the face of the collar is accurately ground, and the hub of the chuck-plate or face-plate fits fairly against it, there will be no difficulty when removing the plate of always being able to replace it in exactly its former position, perfectly true in the running of its face and perfectly concentric with the ground bearings of the spindle. Even the wearing of the thread will not effect its true running, since the only office of the thread is to hold it on, while the ground surfaces insure its trueness. This is shown in Fig. 69. In this connection it is noticeable, that some manufactures omit the large collar on the front end of the spindle and furnish only a small shoulder on the spindle, due to the nose being some- FlG' 69' ~ Nose of sPindle' what smaller than the front bearing, against which the face-plate or chuck-plate rests, and assuming that its close fit upon the ground surface between this shoulder and the threaded portion will be quite sufficient for all purposes. This would seem to be an erroneous view of the question as this comparatively small shoulder cannot possibly afford the support and rigidity that may be obtained by a collar or thrust surface of two or three times the area. It is true that as a matter of economy in furnishing the stock for these spindles the question favors the omission of the shoulder. But and construction. Referring again to Fig. 68, there are several points to which it is proper to call attention. The spindle boxes represented are of bronze and such as are now commonly used in good lathes. The formation of the front end of the spindle with its fixed collar formed in the forging is also the usual practice, except in some of the lathes of newest design and development, in which it is probably omitted as being considered an unnecessary expense. The thrust bearing is similar to that represented in Fig. 74, but an improvement upon it, since a hardened steel ring is interposed between two bronze rings, which render cutting well-nigh impossible. The cone pinion is made of machine steel and has a long sleeve forced into the small end of the spindle cone. While it is not good practice to run two steel surfaces together unless one is hardened, it is still perfectly practicable in this case as the pinion is of ordinary soft machine steel while the spindle is 50 to 60-point carbon crucible steel, which answers the conditions in practice and many lathes are now built in this manner. The spindle is shown bored out, as a large majority of lathes are now so constructed and the demands of the customers require hollow spindles in nearly every instance when the lathe is over 12-inch swing. The proportions upon which this design is made may be interesting. Using the full swing of the lathe in inches as a unit, represented by A, the proportions of the spindle will be as follows: In Fig. 70 we have a spindle of somewhat overgrown proportions, yet one of proportions advocated by an eminently practical mechanic who is said to have remarked that he " didn't want a lathe spindle with a front bearing so many inches diameter and so many inches long, but he wanted it with a bearing so many inches large and so many inches short," by which we may readily understand his idea that a large and short front bearing was much better adapted to the work than one of medium diameter and extra length. Thus if we have a front bearing of 3J inches diameter and 5 inches long, and we increase the diameter 50 per cent and reduce the length in the same proportion, viz., one third, we shall have about the same area of bearing surface, but we shall gain the advantage of bringing the driving-cone closer to the work, of shortening the whole length of the spindle, and of making the front end of the spindle much more rigid and better adapted to withstand the strain of a heavy cut on work of the usual diameters, and still better when large facing work is to be done and the cut is carried I out near the periphery of the largest diameter that can be handled. It does not follow, however, that the proportions of the enlarged diameter of the front bearing need be carried all the way through, by which a spindle of unnecessary weight would be produced, as practically all important advantages may be gained if its dimensions are as shown in dotted lines in the engraving. In Fig. 71 is shown the opposite method of designing a lathe spindle, that is, by making the bearings of the usual diameter, but increasing the length to a considerable extent. It is evident that while there are always certain advantages in increasing the distance between the supporting boxes, there is an apparent tendency to weakness, or lack of rigidity of the spindle at the vital poiot. namely, the overhanging portion of the front end of the spindle The spindle cone should receive due attention. The method of introducing the cone gear sleeve into the small end of the cone has been referred to in connection with Fig. 68. The large end-ef the cone may have an inwardly projecting flange cast integral with it or made separate and attached by screws. In either case the locking bolt must be accommodated in it. Between this head and its bearing it should be well supported from the central quill. This may be done by providing for four or more radial plates extending from the connection with the central quill under the smallest step to one half the remaining distance toward the large end of the cone, as shown in Fig. 68. pose of lessening the friction on the edge of the belt. In cases where this relief is not given to the belt it is not an unusual condition to find the edges of belts running over cones, particularly at high speeds, to be turned up, the corners where the belt is joined to be distorted or worn away, and in a short time the belt well-nigh ruined. In purchasing lathes or other machines provided with speed cones, the purchaser should insist that the faces of the cones should be made as shown, as it is a matter of much importance in belt economy and belt efficiency. TRIPLE GEAR MECHANISM Designing spindle bearings and boxes. Thrust bearings. The Lodge & Shipley form. Ball bearings. Proper metal for boxes. The cast iron box. Early form of boxes. The cylindrical form. Thrust bearings for a light lathe. Experiments with different metals on high speeds. Curved journals. The involute curve. The Schiele curve. Conical bearings. Adjustments to take up wear. Split boxes. Line-reaming boxes. Lubrication of spindle bearings. The plain brass oil cup. The use of a wick. Oil reservoirs. Loose ring oilers. Chain oilers. Lodge & Shipley oil rings. Neglect of proper lubrication. Back gearing. Varying the spindle speeds. Triple gearing. Theory of back gearing. Back gear calculations. Triple gear calculations. Diagram of spindle speeds. Faulty designing of back gears and triple gears. Four examples. A 14inch swing lathe. A 19-inch swing lathe. A 17-inch swing lathe. A 30-inch swing triple-geared lathe. Explanation of the back gear diagrams. Essential parts of the triple gear mechanism. "Guesswork" in lathe designing. Wasted opportunities. Designing the head-stock. Cone diameters. A homely proportion. The modern tendency in cone design. Proportions of back gears. Driving the feeding mechanism. Reversing the feed. Variable feed devices. Rapid change gear devices. GREAT care ought always to be used in the design of the bearings of the spindle and the boxes in which they run. To a great extent these determine the life and usefulness of the lathe, for with an improperly made spindle or poor boxes, either of design or quality of material, the lathe is soon worn so much out of true as to bejDractically worthless. Mention has been made of the thrust bearing at the rear box. It is important that this should be well designed and constructed, as the quality of the lathe's work, particularly face-plate and chuck work, depends upon its proper performance. LATHE DESIGN: THE SPINDLE BEARINGS, ETC. Ill of years on the New Haven lathes. It consists of a hardened steel ring B, forced into an annular groove in the end of the hollow spindle A. The rear end of the bronze box C is extended as shown and tapped out with a fine thread. Fitted to this is the thrust sleeve D, whose forward end bears against the ring B. The sleeve D is adjusted by means of two slots (one of which is shown) cut across its face, and is held in position by the check-nut E. This device is much improved by the addition of a hard bronze ring, loosely interposed between the thrust sleeve D and the hardened ring B. The sleeve D was made of a steel casting, as was also the check-nut E, which had holes drilled around its circumference for the accommodation of a spanner for adjusting it. The device was very successful in practical use. The form of thrust bearing used on the Lodge & Shipley lathes is shown in Fig. 74, and is constructed as follows : Upon the spindle A is keyed the cast iron ring B. Next to this is a bronze washer C; next a hardened steel washer D; then another bronze washer E, which in turn rests against the faced end of the rear box F, which in this case is formed of the head-stock casting itself. While this is an efficient form of end thrust it has the disadvantage of occupying some space inside the rear box and consequently increasing the distance between the front and rear boxes, increasing the length of the head-stock by just its own width, or the space occupied by the cast iron collar and the three friction washers. Unless covered by a projecting portion of the casting, or by a special guard over it, there will be more or less trouble on account of dirt working in between the washers. This, however, is easy to prevent by a proper design and construction. The popularity of the ball bearing and its successful application to many different uses no doubt suggested it as a proper device for the thrust bearing of a lathe. It has been objected to in a lathe designed for fine work, on account of the possible influence of any slight vibration caused by the rapid rotation of the balls, owing to any inaccuracy in their perfect spherical shape or diameters. Yet the device is in apparently successful use on many lathes at this time. The construction is shown in Fig. 75. Upon the spindle A is fixed the collar B, having a ballrace cut in its rear side as shown. Fixed to the end of the box, or the inside of the rear housing, as the case may be, is the collar C, which also has a ball-race formed in it, and set deep enough to form a sleeve which the lathe spindle. It is entirely feasible, however, to place this device, or the one shown in Fig. 74, near the rear end, or even at the center of the rear box if so desired. In this location it would have the added advantage of position for ample lubrication and absolute protection from dirt. There has been a great deal of discussion on the question of what is the proper metal, and what is the proper form for a lathe spindle box. Any number of different metals have been used for this purpose, from cast iron at a cost of two and one half cents per pound to a fine quality of nickel-bronze worth thirty one cents per pound. It is an old and a true saying that with a good, true, and well finished journal, and the bearing kept free from dirt, always clean and well lubricated with good oil, a cast iron box is as good as anything that can be made. Every practical shop man of even moderate experience can cite instances of the excellent record of the old-time cast iron box, and the fact that it is still used by some of the oldest and best lathe manufacturers is certainly a strong argument in its favor. But one condition is always insisted upon : it must be kept clean and free from dirt. It will not stand dirt. Under adverse conditions many bronze boxes withstand successfully dirt, grit, and poor lubrication that would put the cast iron box out of business in a few hours. Of course it is assumed in all these remarks that the lathe spindles are made of 50 to 60-point crucible steel, and that they have been accurately ground, as this is the only method by which we can insure the perfect cylindrical form of the bearing that is so necessary to the successful operation of a lathe. The older form of designing the housing of the head-stock for the reception of the boxes was to have the opening at the head and rear end of square form and covered by a straight bar of cast iron or machine steel, secured at the ends by hexagonal headed cap screws. Later on it was found more economical to make these spaces circular and to have them bored out with a boring bar, the boxes being fitted to the circular opening and capped down, when the inner surface of the box itself was bored out and hand reamed. For small lathes, such as bench lathes and precision lathes, it is necessary to carefully exclude dirt as well as to have correct bearings, since a good, true bearing will not long remain so if exposed to dust and dirt or even to poor and dirty oil used as a lubricant. In Fig. 76 is shown a thrust bearing for a light lathe that is provided with an adjustment on both the front and the rear side of the rear housing. This is done by providing the steel collars B, B, threaded to fit the spindle A, so as to allow adjustment at either end, and that one of these collars at each end shall FlG" 76 s~a^eLat^eearing for act as a check-nut to the other, between the steel collars and the face of the housing. The faced sides of the housing project to the front and rear a short distance, and this projecting part is threaded and has fitted to it the dust-caps D, D, which may be made of steel, as shown, but are frequently made of brass. They are bored to fit the spindle rather closely so as to more effectually exclude dirt. In some instances it may be advisable to place outside of the outer collar B a felt washer closely fitting the spindle, which will be an effectual means of insuring a clean bearing. If the thrust on the spindle is considerable, it may be well to interpose two washers so as to decrease the friction, and for still heavier thrusts we have always recourse to the plan of using a steel washer with a bronze one on each side of it, which will in nearly every case be found sufficient even with a very heavy end pressure. In the case given in Fig. 76, it will be noticed that the spindle runs in a reamed hole in the cast iron of the head-stock itself. This has been so arranged purposely and forms a very good bearing when carefully protected from dirt. Such bearings may, of course, be lined with genuine babbitt metal or with brass, bronze, or any of the so-called " anti-friction metals." In an extended series of experiments, the purpose of which was to ascertain the best materials for a shaft and a box running at high speeds, in this case 7000 to 8000 revolutions per minute, it was demonstrated that a hardened and ground tool steel spindle, running in a box of cast tin, bored, reamed, and scraped, would far outlast any of the dozen or more materials tested. The inner surface of the box soon took on a glaze that was nearly black and very glossy, and this was retained during over a year's wear to the author's personal knowledge, and probably much longer. In this series of experiments a steel shaft and steel box was ruined in less than an hour's run. straight line, but conical, inclined two degrees from the axis. The remainder of the length has either an involute or elliptic form to a diameter 60 per cent larger than the small end of the bearing. The involute form is preferable, while the "Schiele curve" is, of course, the ideal contour. The spindle is held in place by the collars B, B, threaded upon the spindle A, and a bronze washer C, interposed to eliminate friction. While this is theoretically correct and entirely practicable, it is an expensive bearing to make and to fit up in small numbers, and when special tools are made for it they are expensive to maintain. grees with the axis, and the angle at the large end is twenty degrees from a right angle with the axis. In practice it is much more economically made and FlG- 78- — Conical Front Bearing, fitted and answers all conditions nearly as well. The arrangements for taking up wear are the same as those shown in Fig. 77. In neither case is a thrust bearing required at the rear box. In some respects, particularly in small lathes, this is considered the better practice. spindle is gradually but surely wearing lower. This is corrected by placing pieces of paper or very thin metal under the lower box. But as sufficient attention is seldom given to this point in keeping a lathe in proper condition, it is most unusual to find a lathe whose centers are in perfect alignment. In the present case the spindle A is cylindrical, that is, with no taper, and runs in a hard bronze sleeve B, which has a taper of two degrees on each side and fits closely in the taper reamed hole in the head-stock housing. This bronze sleeve is split through its length and arranged to be drawn into the taper hole by means of two nuts C, C, threaded upon its small end. One of these nuts acts as a check-nut to the other. Therefore the bronze sleeve may always be drawn as tightly around the spindle bearing as may be desired, and effectually held in that position. As the compression is the same through the entire circumference, the spindle will retain its central position and correct alignment even after a very considerable amount of wear, and a new bronze sleeve may be readily fitted when the first one is worn out. This substitution is not only economical but the exact alignment is still preserved. It may be argued that this sleeve, like the split box, will wear most at the bottom. This is perfectly correct, but an occasional turning of the sleeve through a quarter or a sixth of a revolution, effectually corrects this tendency. tion of felt washers. However these bearings are made and whatever care may be exercised in machining and fitting the boxes or in securing a correct alignment of the circular or square receptacles in the housings for receiving the boxes, it will be found generally necessary and always safe and advisable to " line-ream" the boxes after they are in place and securely clamped. This is done by fixing very carefully ground shell reamers upon a perfectly true arbor or mandrel, and hand reaming both boxes at the same time. The previous diameters should have been made very close to the finished dimensions so as to leave as little as possible to ream by hand. Really the cutting edges of the reamer should barely scrape out a very trifle of the metal. In fact, it should be rather a scraping than a reaming job, necessity for its use. In the drawings illustrating the different forms of bearings and spindles the devices by which the journals are lubricated have been omitted so as not to confuse the question. The matter of lubrication is, however, an important one, and will next claim our attention. In many cases the spindle bearings are lubricated by means of a simple oil hole closed by a plug of brass. In others a short vertical tube is inserted and covered by a cap which entirely encloses it. In still others the " plain brass oil cup" is used, that is, a simple receptacle, usually urn-shaped, whose top is closed by a cover screwing into it. Again, various patented devices are employed, ranging all the way through "good, bad, and indifferent," whose object is to furnish easy access to the oil tube and to provide, in many cases, for the automatic closing of the oil tube or reservoir for the purpose of excluding dirt. An improvement upon the plain brass oil cup is shown in Fig. 80. This improvement consists in the introduction of a vertical tube A, whose lower end opens into the hole leading to the journal bearing. This tube is fitted with a wick B, whose lowrer end rests upon the journal C, and whose upper end is coiled loosely about in the oil chamber. When the oil in the reservoir is above the top of the tube the wick prevents the oil from running down too rapidly. When the oil is below the top^of the tube the wick acts as a siphon and thus insures the lubrication of the bearing. The use of a wick is resorted to in the next example, shown in Fig. 81. In this case an oil reservoir is formed in the housing of the head-stock A, and a suitable opening in the form of a slot parallel to the axis of the spindle is cut through the lower box. Into this is fitted a flat wick B, or piece of coarse soft felt whose upper edge rests against the bottom of the journal C, and whose lower end is immersed in the oil filling the reservoir. Capillary attraction is depended upon for drawing the oil up to the bearing, although with oil at the height shown in the cross section, on the right of Fig. 81, the oil is gradually forced up to the under side of the journal. This plan has the advantages of keeping the journal and its lubricant free from dirt; of straining the oil so that any dirt it may contain will not reach the bearing; of providing for a quantity of oil so as to make frequent additions to the supply of oil unnecessary ; and of furnishing a handy method of introducing a new supply of oil, by way of the hole D, closed by the stopper E. which the sediment and dirt may be gotten rid of when necessary. This tube is closed by a stopcock. This method of lubrication is very largely and successfully used in countershaft boxes, which, from their comparatively inaccessible position are very liable to be neg- lected in the matter of proper lubrication. The use of a loose ring for raising oil to the journal bearing is shown in Fig. 82. In this case a loose, flat ring B, of considerable larger inside diameter than the diameter of the journal C, is placed around it and allowed to hang down into the oil in a reservoii formed in the head-stock A, similar to that shown in Fig. 81. The revolution of the spindle is usually sufficient to keep the ring in motion so as to draw up a sufficient supply of oil to lubricate the bearing. In this case, also, oil may be introduced through the hole D, usually closed by the stopper E. One ring is sufficient for a bearing and is placed in the center of it, the box or box lining material being grooved out for this purpose. In Fig. 83 is shown a similar device to the above, except that a flat linked chain is used instead of a circular ring. It is obvious that by lengthening the chain it will necessarily dip deeper into the oil than a circular ring possibly could, while the openings in the links of the chain will more readily carry up the oil than will a smooth ring devoid of openings or raised parts. Fl<5' 83' ~ The Loose Chain Oiler' In both the above cases an internal groove is cut in the inside of the journal box to accommodate the ring or chain, and an opening made entirely through at the bottom for the entrance of the oil. A modification of the ring device is shown in Fig. 84, which illustrates a type of lubrication used in the Lodge & Shipley lathes. It consists of a ring B fixed to the journal and having formed upon it four buckets G, G, G, G, opening in the direction of rotation, whose function is to dip up the oil as they pass through the reservoir and to pour it over the journal as they successively pass over the highest point of their revolution. Suitable ducts distribute the oil length wise of the bearing and return it to the oil reservoir to be used again and again. Thus a positive provision is made for supplying the journal with oil, and the manufacturers assert that a spindle so fitted up will run for a month without a new supply of oil. The oil reservoirs are said to hold about a pint and the supply is introduced through the oil hole D, which is provided with the glass tube F, closed by the stopper E, and through which the height of the oil in the reservoir may be observed through the opening cut in the metal surrounding the glass tube as shown in the engraving. The practical utility of such a means of lubrication is at once apparent, as the neglect of workmen to attend to the proper lubrication of lathe spindles, as well as many other parts of the machine where oil is necessary, is one of the most fruitful sources of lathe difficulties that occur. And a spindle that has been allowed to "run dry" and its finely ground and polished surface to become cut and "roughed up" is very difficult to ever get in as good working condition again as before this kind of abuse happened. The author has known of instances where the designer had provided an oil reservoir which had been filled when the lathe was being tested and which had operated well and lubricated abundantly. The lathe was shipped to a customer, set up and run, and in a few months the parts returned completely destroyed from lack of lubrication, the fact being evident that no oil had ever been placed in the reservoir when the supply first introduced, as above stated, was exhausted. Such neglect of the most ordinary precautions is a good illustration of the very poor shop conditions which still exist in some otherwise well-managed shops. The gearing in the head-stock of a lathe by which the speed of the spindle is varied is in general terms called the "back gearing," since the purpose of it is to "gear back," that is, to reduce the speed of the spindle. There are three methods of changing the speed of the spindle, namely: by running the driving-belt on the different steps of the cone; by means of the usual back gearing; and by means of what might be termed a secondary back gear, or as generally termed the back geared engine lathe. At the top of the engraving is shown the countershaft cone A, as this performs an important part in the changing of speeds. The spindle cone B runs loose upon the lathe spindle and is fixed to it at will by a lock bolt passing through the face gear C, which is permanently keyed to the spindle. U#on the small end of the cone is fixed the cone pinion D, which meshes into the back gear E, which is fixed at one end of the back gear quill, or sleeve G, which carries at its opposite end the quill pinion F. This quill runs freely upon a shaft called the back gear shaft, which is provided at each end with eccentric bearings, and at one end a lever for operating them, by means of which the back gear quill G, with the back gear E and quill pinion F, may be thrown out of engagement with the cone pinion D and the face gear C. The operation of the device is as follows: the cone B, rotating the cone pinion D at a certain speed, and the back gear E being engaged with it, will rotate the latter at a speed proportional to the number of teeth in the two gears. In this case the cone pinion D having 32 teeth, and the back gear E having 88 teeth, the ratio of their respective revolutions will be as 2f to 1 ; therefore, if the cone were running at 275 r.p.m. (revolutions per minute), the backgear quill would run at 100. This speed is still further reduced by the quill' pinion F and the face gear C. These two have respectively 24 and 96 teeth and consequently a ratio of 4 to 1, so that the spindle speed, by the introduction of the back gears and the withdrawal of the lock bolt attaching the cone B and the face gear C to each other, will be reduced to 25 revolutions. Therefore, if we divide the revolutions per minute of the spindle cone by the ratio of the cone pinion with the back gear multiplied by the ratio of the quill pinion with the face gear, we obtain the spindle speed. Or, in detail, in this case, 88-^32 = 2.75, and 96 -r- 24 = 4, and 2.75 X 4 = 11, which is the combined . ratio or the normal back gear ratio. In short, the cone speed divided by the back gear ratio will give the spindle speed, thus : 275 -^11 = 25. The various speeds given to the spindle cone by belt changes depend, of course, upon the porportions of the diameters of the various steps of the cone. When there are five steps on the cone, the central step on each cone is usually of the same diameter, and as the two cones are generally cast from the same pattern, so far as the outer shell is concerned, it is simply a question of reversing one so that the belt shall be on the largest step of one and the smallest end of the other, or the intermediate step above or below the central step. and 8 inches in diameter, and the ratios as follows, viz. : 20 to 8 = 2.5; 17 to 11 = 1.545. These ratios multiplied or divided (according as to whether the step on the countershaft cone is larger or smaller than the one used on the spindle cone) by the revolutions per minute of the countershaft will give the various cone speeds. Figure 86 is a diagram of the driving mechanism of a triple geared lathe. So far as the countershaft cone, spindle cone, and the back gearing are concerned it is identical with the mechanism shown in Fig. 85, except that the quill pinion E is so constructed as to slide out of engagement with the face gear, and also that there is a third gear on the back gear quill G, namely the pinion H, which engages the gear J fixed to the triple gear shaft K, which also carries the internal gear pinion L, which in turn engages the internal gear M fixed to the back of the face-plate P, which is attached to the front end or nose of the lathe spindle N. The triple gear shaft K is adapted to slide endwise in its bearings, and to be retained in either position so as to bring the gear J and pinion L out of engagement with the pinion H and internal gear M when the triple gear is not in use. This position is represented in the engraving by dotted lines. As the pinion H has 30 teeth and the triple gear J has 90 teeth, the ratio existing between them is 3. And as the pinion L has 20 teeth and the internal gear has 200, their ratio is 10. Therefore, these two ratios multiplied together is 30, which multiplied by the ratio of 2.75, existing between the cone pinion D and the back gear E, produces 82.5, which is the triple gear ratio. It will be noticed that in this calculation the face gear C and quill pinion F are not taken into account, as they are not engaged when the triple gear is in operation. To graphically illustrate the spindle speeds the diagram in Fig. 87 is given. The principal curve beginning at the bottom of the diagram shows the five cone speeds and the five back gear speeds, while the diagram at the top on a much larger scale gives the five triple gear speeds. From this diagram a good idea of the proportions and the regular progression of speeds may be obtained. While the progression of speeds shown are those proper under the circumstances, it will be found that there are many lathes in the market in which they are not realized, often, doubtless, owing to careless designing. In making this statement it is not meant that the slowest and the fastest obtainable speeds are not proper.. It does not mean that the high speeds are not fast enough, since we can readily get a faster speed by speeding up the countershaft. In the same way we may obtain a slower range of speeds by reducing the speed of the countershaft. But what is meant is that as between the three series of speeds known as cone speeds (or open belt speeds), back gear speeds, and triple gear speeds, there will be too much of a break between these divisions or groups, or there will be an overlapping of speeds so that one or two speeds of one group are very nearly duplicated in the next higher or lower. In this way a triple geared lathe of nominally fifteen speeds will give but thirteen practically different speeds. In the example given in Fig. 87 it will be noticed that the speeds rise in a very regular progression, the numbers up the sides of the diagram giving the speeds and those beneath giving the serial number of the fifteen speeds from slowest to fastest. fastest speed of the back gear and the slowest of the cone speed. This amounts to a difference of 47 revolutions, as the former is 48.9, and the latter 96. The entire range of speeds is : gear ratio is 8.08 to 1. In this lathe a four-step cone is used, therefore giving only eight speeds. The lathe is a small one, the swing being 14 inches and intended for light work and a comparatively fast range of ably larger than the spindle cone, which is an unusual condition. In the next example a lathe having a five-step cone is selected. It is a 19-inch swing lathe and intended for much heavier work and back gears having a much wider face, in fact 50 per cent, while the pitch of the teeth is in about the same proportion. In this case the increase of speed between the fastest back gear speed and the slowest cone speed is 23.7, while the next speed below varies only 10 revolutions, which is a palpable fault in the caclulation of the speed progression. The following are the spindle speeds : should be, but the proper progression is at fault. Figure 90 is a diagram from a lathe of 17-inch swing and having a five-step cone, a back-gear ratio of 12 to 1, and a countershaft speed of 150 revolutions per minute. The same fault of too great a difference between the fastest back gear speed and the slowest cone speed is observed. ence below is only 11.35. The next example is of a 30-inch swing, triple geared lathe in which the speed calculations show an error only too common among lathes of this type. It will be noticed by reference to the engraving, Fig 91, that the countershaft cone is considerably larger than the spindle cone, which is entirely unnecessary since the same object might have been secured by running the countershaft faster and the parts need not be so heavy or expensive. The questions of proportion and progression of speeds can be easily taken care of when both cones are alike, if the proper calculations are made. By reference to these figures it will be seen that the triple gear speed of 6.44 exceeds both the back gear speeds of 3.45 and 5.82, which renders them comparatively useless, ^or which makes the two tical use. Hence, we have a lathe provided with fifteen nominal speeds, which really has but thirteen. This point will be more readily appreciated by referring to the speed curve shown in the diagram, Wrongly Designed. Fig. 92, and the faults of designing more clearly brought out by comparing this diagram with the two curves shown in the diagram given in Fig. 87, being careful to note that the upper curve repre- senting the triple gear speeds is drawn to a scale ten times larger than the curve for the back gear speeds and the cone speeds. The object of this was to show more clearly the progressive increase of the triple gear speeds, whose continued upward tendency would properly join with those of the back gear if the latter were drawn to the same scale, which the dimensions of the page would not admit. The figures for these speeds are given on a previous page, to which the reader is referred, and a comparison with the speeds given in the last example is suggested. In the diagrams of driving mechanisms in Figs. 85, 86, 88, 89, 90, and 91, the countershaft cone is shown above the spindle cone and the back gear and triple gear mechanisms below. This is so arranged for convenience in giving the relative dimensions and proportions of the parts. While it is the usual method to place the back gear device at the back of the lathe head-stock or in the rear of the spindle, it is not at all necessary that it should be so placed, and in fact, on some of the larger lathes, it is placed in front of the main spindle as a matter of convenience. The essential parts of the triple gear mechanism in connection with the usual back gears are well represented in the rear view of a head-stock shown in Fig. 93, in which the triple gear device is shown engaged and the quill pinion thrown out of engagement with the face gear. In this case a clutch connection between the back gear shaft and the triple gear shaft serves to handle the pinions on both so as to be moved into and out of engagement at one and the same time, thereby running the lathe as a back geared or a triple geared lathe, by a very simple and convenient change. The design is of a lathe built by Lodge & Shipley. While it is not the intention of the author to assume to present in this work an exhaustive treatise on lathe design, for the reason that the scope of the plan is not extensive enough to permit it, and for the further reason that it does not seem necessary in view of the objects for which it is written, it does seem thoroughly in keeping with what is proposed, to give such facts as to some of the more important points of design as will serve as cautions to the designer, as interesting lines of thought to the machinist, and as information to the buyer of lathes. ject which seem to merit still further consideration. Any one who will take the trouble to examine, as the author frequently has, a lot of lathes in almost any machine shop and to make the most superficial calculations of their speeds, will be surprised at the amount of apparent "guesswork" that has entered into their design. The speed curve shown in Fig. 92 is a case in point. Narrow-faced back gears without any calculations, so far as one may see, of the strain which they must bear; small pinions, whose teeth are soon ground away on account of the sharp angles of their action; a lack of proper proportion between cone dimensions and back gear dimensions; and many other similar faults. We have all seen lathes with a 3-inch vertical belt on a 5-inch cone, while the overhead horizontal belt driving the countershaft was 4 inches wide on a 15-inch pulley; when every mechanic knows that a horizontal belt will drive more than a vertical one, aside from the difference in the diameters of the pulleys being all in favor of the larger pulley. that the money spent for these machines should have produced much more really practical and useful machines than it has, and that they should have been capable of turning out a much larger output than we find them doing. In designing a lathe head-stock the triangle formed by the distance from center to center of the inside V's, as a base, and the lathe center the apex, should be an equilateral triangle. Sufficient material must be provided under the largest step of the cone and the face gear to give the requisite strength and rigidity. The large step on the cone should, fill the remaining space with the exception of a sufficient clearance for the belt. The large diameter of the cone having been thus fixed the diameters of the other steps are a question of proportion, according to how many steps there are and what is to be the smallest diameter. It is common practice to make the steps of the spindle cone and the countershaft cone identical. This, on a five-step cone, will give a spindle speed (without back gears) equal to the countershaft speed when the belt is on the middle step. The spindle speed will be correspondingly faster or slower according as the belt is on the smaller or larger steps of the spindle cone, and in the same proportion as the cone steps are to each other. The cone diameters having been fixed the back gear ratio must be made to correspond. Only one can be fixed, and the other must be arranged to correspond with it. A homely proportion, but one that will come out very nearly right in practice, in determining the proper width of face for the cone steps, will be one seventh of the swing of the lathe when no triple gears are used. If triple gears are used it is common practice to make the belt a trifle narrower. The present tendency is towards wider belts and it seems to be a very proper development made necessary by modern shop, conditions and the use of high-speed steel tools. It is altogether probable that belts will be made wider rather than narrower in the future. There is also a tendency to make the differences between cone step diameters less, which gives a larger diameter to the smaller steps, and consequently more power in the driving mechanism of the lathe and avoids the necessity for very tight belts. Ordinarily, the width of the face gear should not be less than eight tenths of the width of the cone steps, and the width, of the back gear not less than six tenths. Of course, the pitch. -v teeth should be in proper proportion to the width of the fact, <1 in the larger lathes the pitch of the teeth of the face gear should be one number coarser than that of the back gear. Usually the face gear has an outside diameter about equal to that of the largest step of the cone, but should not be larger. The outside diameter of the cone pinion should not be much smaller than the smallest cone step. These dimensions thus coming within rather narrow limits, the diameter of the back gears and that of the quill pinion will be governed by the ascertained or the arbitrary back gear ratio. In order to avoid the interference of a large back gear with the desired form of the head-stock at this point, and to secure a symmetrical contour, the back gear shaft can advantageously be raised above the level of the main spindle. This is permissible to the extent of 1 J inches on a 36-inch swing lathe. The method of transmitting the power from the spindle to the feeding mechanism, formerly done almost exclusively with a belt on cone pulleys, one of which was upon the head shaft (located below the spindle and driven by it through the medium of gears), and the other on the feed rod. The lead screw was, of course, driven by gears so as to obtain a positive motion. In modern lathes nearly all have gear-driven mechanism for both the rod feed and the screw feed. The former practice of reversing the feed in the head-stock is now to a large extent abandoned, and this function performed at the apron, and is much more convenient to the operator. The mechanism for driving the lead screw in thread cutting and for a large range of feeds is now very popular and is accomplished wholly by gears with appropriate levers, shafts, and clutches. Those for driving the feed rod are usually known as " variable-feed devices" and those for thread^ cutting are known as "rapid change gear devices." It is not unusual to find these combined so that one set of variable-speed gears is adaptable to both functions. Functions of the tail-stock. Requisites in its construction. The Pratt & Whitney tail-stock. The Reed tail-stock. The Lodge & Shipley tailstock. The Blaisdell tail-stock. The Hendey-Norton tail-stock. The New Haven tail-stock. The Prentice tail-stock. The Schumacher & Boye tail-stock. The Davis tail-stock. The American Watch Tool tailstock. The Niles tail-stock for heavy lathes. New Haven tail-stock for heavy lathes. The Schumacher & Boye tail-stock for heavy lathes. The Bridgford tail-stock for heavy lathes. The Le Blond tail-stock. The lever tail-stock. The lathe carriage. Requisites for a good design. Description of a proper form. A New Haven carriage for a 24-inch lathe. The Hendey-Norton carriage. The Blaisdell carriage. The New Haven carriage for a 60-inch lathe. Criticisms of a practical machinist on carriage and compound rest construction. Turning tapers. The taper attachment. Failures of taper attachments. The Reed taper attachment. The Le Blond taper attachment. The Lodge & Shipley taper attachment. The Hamilton taper attachment. The Hendey-Norton taper attachment. The New Haven taper attachment. The Bradford taper attachment. THE function of the tail-stock is to support the end of the piece of work opposite to the head-stock; to furnish a movable center for various forms of drills, reamers, and similar tools; and to carry one end of boring bars when the work is clamped to the carriage. For these purposes it must be of sufficient strength and rigidity to withstand the strain to be put upon it; it must have a traveling spindle to carry the tail center; and be capable of being "set over" in a direction at right angles to the center line of the lathe, for the purpose of turning tapers, and in some types of lathes for boring operations. It is fitted to the two inner V's of the lathe the same as the head-stock, so as to permit the carriage wings to run past it, and must be capable of being securely clamped in any position along the length of the bed. The spindle must, be adapted to be handled by a hand wheel upon the traverse screw in small and medium sized lathes, and in large lathes located conveniently in front1 and connected with the screw by suitable shafts and gearing. The spindle should be adapted to be clamped at its front end in an efficient manner so as to hold it firmly and at the same time not to force it out of correct alignment with the head-stock spindle. The tail-stock should have a long bearing upon the V's, which should be at least two thirds of the swing of the lathe. The bolts for clamping it down should be considerably nearer the front than the rear end so as to counteract the lifting tendency due to pressure against the center. In lathes of 12 to 30-inch swing two bolts will be sufficient to rigidly secure it to the bed. In larger lathes, four bolts should be used. For the purpose of setting over for turning tapers the tail-stock is composed of a low base and the movable part of the tail-stock proper, the transverse adjustments being made with a cross screw furnished with a square head. The two parts are held together by the holding-down bolts which secure the tail-stock to the bed. In larger lathes, say from 30-inch swing up, the division between the two parts is near the top, which should be secured by an additional set of four bolts so that the spindle may be set over without releasing the holding-down bolts which secure it to the bed. Thus, if a heavy piece of work is supported upon centers the tail spindle may be set over for turning tapers without removing the work from the centers. In lathes of 24-inch swing and over there should be a rack and pinion device for moving the tail-stock to any desired position on the bed. In lathes of 36-inch swing and over this device should be back-geared so as to give sufficient power to easily move the heavy mass. This back gearing should begin with a ratio of two to one, and increase as the lathe is larger and the tail-stock is heavier, so that one man may conveniently do the work. ticular feature is the overhang at the front end for giving extra support to the spindle. The spindle is larger than usual, which gives better support to the center and is very useful when using it to support the rear end of a Figure 95 shows a front FIG. 94. — 14-inch Lathe Tail-Stock, built view of a Reed tail-stock for b^ the Pratt & Whi^ey Company, a 27-inch swing lathe. It will be noticed that the holding-down Figure 97 is an excellent view of the Lodge & Shipley type of tail-stock for small lathes, and shows their device for clamping the spindle, and the mechanism stantial appearance. Figure 98 is the tail-stock used on 20-inch swing lathes built by P. Blaisdell & Company. The only noticeable feature is the unusual diameter of the tail-spindle sleeve in proportion to its sup- work and a considerable improvement on the one just before it. It is secured to the bed by a lever and eccentric arrangement similar to that shown in Fig. 94. Figure 100 shows the New Haven Manufacturing Company's tail-stock for 24-inch swing lathes. A finished sleeve screwed into the rear of the main casting furnishes the support for the tail-spindle screw and adds to the otherwise clean outline and substantial appearance of the base. It is very rigid and substantial. Figure 101 shows the Prentice Bros. Company's tail-stock, which they claim as their invention so far as American lathes are concerned. Other than this fact there is nothing particularly notice- able in its design except that there are two ribs and grooves, one to each bolt for preventing the undue strain on the holding-down bolts. These bolts are well spread apart, which is a good feature in some respects if not in others. ring Company. The Schumacher & Boye tail-stock shown in Fig. 102 is a good general design and resembles that of the' Hendey-Norton manufacture. Aside from the very prominent cap at the rear end it is a very creditable appearing device, and considerably better than some of those short and square forms which appear " all in a bunch," as it were. Figure 103 shows the W. P. Davis machine Company's production, which is of fairly good proportions and has ample strength. While it is for only a 28-inch swing lathe, it is provided with a rack and pinion device for moving it along the bed. be removed or blocked up when setting over for turning tapers. As the spindle sleeve is very long and the tail spindle large and heavy, a spur gear is keyed to the spindle screw and engages a spur pin- gear which engages with a similar one fixed to a short transverse shaft upon whose front end is a large hand wheel by which the tail spindle is easily and conveniently operated. The ratio of this gearing is 3 to 1. The tail- Machine Tool Works for their 42-inch swing lathe. It is of peculiar design and the base has the appearance of having been " built up in the sand," from the pattern designed for a lathe of much less swing. It is not a handsome design by any means, although it probably serves the purpose of supporting the tail spindle. It has a rack and pinion device for moving it along the bed. Its length on the bed is not as great as it should be, nor do the holding-down bolts seem large enough for a lathe of 42 inches swing. It has four bolts for holding down the base and a second set for securing the top part carrying the tail-spindle sleeve. center, which is a very desirable feature. From the foregoing illustrations and descriptions the various features of tail-stocks, made by the different manufacturers, may be quite readily studied and their good and bad points duly considered, either for the pur- This form offers facilities not possessed by the other form, or possessed in a less convenient form. In this spindle may be carried drills, reamers, etc., for use on light work held in a chuck. It may carry a small face-plate against which work may be held and drilled or reamed by a drill or reamer held in a chuck. It may carry an inside boring tool, and if made with a " set-over" device, such as is used on the tail-stock of an engine lathe, its usefulness is still further extended, particularly when working brass or other soft metals or materials. This design is by the F. E. Reed Company. In addition to all the requirements thus far enumerated, which a lathe must possess in order to do good and heavy work, it must have a substantial carriage and compound rest or other tool-holding mechanism. The carriage must support the compound rest on top and the apron hanging down at the front. Through the latter it must receive its driving mechanism as the lathe is now constituted. If we were to design a lathe with a view only to the theoretical requirements, we should, of course, put the device for moving it along the bed "on the cut/' as near the cutting- tool as possible, and therefore the lead screw and feed-rod would be inside the bed and at some point between the front V and the central line. But we all know the practical objections to this and recognize it in lathe design. There are a few points in the design of a good lathe carriage that it will be well to call attention to, since they are those that are frequently lost sight of, if we consider many of the present-day designs, and that the buyer of lathes as well as the machinist will do well to give attention to. Figure 111 shows the design of an ordinary engine lathe carriage intended to be rigid and substantial. It has a wide center part, which is properly supported by the two ribs, thick and deep in the center. The only opening through it is one of moderate dimensions for permitting the chips to pass through. The entire top is on one level so that large work to be bored may be bolted down upon it when the compound rest is removed for that purpose. Some lathe carriages have the dovetail, upon which the compound rest shoe runs, raised above the general level of the carriage. When work is to be bored it must rest upon this in the center while the sides are supported upon parallels with attendant inconvenience in bolting down rigidly. In this design there are four T-slots in front and two in the rear for the accommodation of bolts, while others may be passed through the chip opening in the center if necessary. The front wings of the carriage are broad, for the purpose of properly accommodating a full swing rest, an additional tool-post or other tool-holding device. The T-slots in the rear may serve a like purpose, or in conjunction with those in front serve for holding down any special attachment necessary. surfaces for the carriage inside of the V's, the inner V's being replaced by flat surfaces, thus permitting the swing to be increased and the carriage very materially strengthened. facturers. Figure 112 shows the carriage, apron front, and compound rest of a New Haven 24-inch swing lathe. The T-slots in the rear wings of the carriage are as shown in Fig. Ill, but those in the front wing are at right angles. In some cases this is preferable, but if the carriage is to be used much for boring purposes the slots will be found most desirable if all in one direction. The top of the The apron front is clear of gears and other similar obstructions, and the uses of the levers are indicated by plain lettering on the front of the apron. As the levers are set in the engravings all feeds are "out." The "star nut" closes the friction of the driving bevel gear, and the feed is "on" to the right or left according as the lever, marked "to reverse all feeds" is thrown to the right or left. To operate either the lateral or cross feeds the upper lever is thrown to the left for "lateral feeds," and to the right for "cross-feed." The lever at the extreme right closes the "split nut" on the lead screw, provided the feeds are not engaged. That is, if the levers are as shown the lead screw nut may be closed. But if the lever "to reverse all feeds" is moved to the right or left, the split nut is locked "open" and cannot be closed. adapted to be engaged on either side of the driving bevel gear which transmits the motion through the medium of a conical friction clutch operated by the "star nut" in front of the apron. Further than these bevel gear connections there are no gears but those leading up to the cross-feed screw and back to the rack pinion and hand-wheel shaft. No worm or worm-gear is used. Consequently the parts are large, strong, and durable. The compound rest, as will be seen, is of ample proportions, has a graduated base, a convenient removable double crank, and a tool-post provided with a concave ring and washer adjustments for the tool. single crank on the compound rest screw is not as convenient for many uses as a double crank. The cross-feed screw carries a very convenient graduated disc, which ought to be provided for all lathes up to 32-inch swing, and is useful in many ways for even larger lathes where fine work is to be done. Figure 114 shows the carriage, apron, and compound rest of the Blaisdell lathes. While the construction is strong and substantial, it cannot be said that it is very symmetrical or with any attempt at fine lines. The arrangement of the apron front is riage and apron are the same length, which usually indicates that the bearing of the carriage on the bed is not as long as it might be to good advantage. The cross-slide dovetail projects above the general level of the carriage so that it would be in the way for boring operations. heavy steel clamping bars held up under the nuts by large spiral springs so that the tool may be readily introduced. These clamping bars project, at the ends, beyond the holding-down studs so that the tool may be placed outside the studs when the nature of the work requires that position. The entire device is very strong and rigid and capable of withstanding very heavy cuts. There is a power cross and angular feed in addition to the facilities for hand feeding in all directions. Further illustrations and comments upon the various features of this class on the lathes built by different makers will be found in later chapters of this work, describing the entire lathes, and to which the reader is referred for further information. A practical machinist has recently made the following criticisms upon one of the popular lathes which shows the standpoint from which the practical men look at some of the lathe features. It is so eminently commendable as to be well worth preserving. First. — The tool block will not travel beyond the line of centers to permit holding small boring tools directly in the tool-post by means of any of the holders so often described which use V-block clamps and make a handy tool-holder. This distance is short 8\ inch. It is often convenient to get beyond the centers, and to my mind, at least, an inch is a great advantage. Second. — The stock in the tool-post is so short that it is impossible to use packing on top of the tool when doing delicate work with small tools made of wire or small straight bars, and without such packing the value of this style of tool is lost. The top of a J x 1-inch tool can be raised but T36- inch above the centers. Third. — The tool-post screw is so short that the wrench runs into the clamp handle of the tail spindle, and either the rest must be removed or the wrench taken off and the screw turned with the fingers when more than a bare loosening is required. The addition of f inch to the length would avoid this difficulty and also permit the wrench to swing clear over the small face-plate. Fourth. — The key in the lead screw for change-gears is of the Woodruff style, and falls out every time a gear is taken off. Of course this gear does not require changing often ; if it did this nuisance would be unbearable and call for a properly fitted and fastened key, but as it is, the gear is changed so seldom that one forgets this key, and so it drops and must be hunted for nearly every time a gear is changed. Fifth. — The centers are of No. 2 Morse taper, but the holes are reamed just enough larger or deeper so that no tool of that taper as fitted to the regular Morse socket can be held without a sleeve of metal or paper. This may have its advantages in preventing the too common use of such tools in the center holes, but is sometimes a great aggravation in a tool-room lathe, where every convenience would be duly appreciated. Sixth. — The face-plate fit, so far as the screw thread is concerned, is all right, but the part chambered out next the shoulder is TV inch larger than the top of thread, which makes it quite difficult to start the thread true when putting on plates or chuck, with the results that the thread often jams in starting, especially with a heavy chuck. The turning of tapers is often accomplished by " setting over" the tail-stock to the front or rear as may be desired, so as to be out of line with the head-stock center and thereby inclining the axis of the piece to be turned with the axis of the lathe. While this is a convenient and efficient manner when the taper is one of moderate inclination, it can only be done within comparatively narrow limits. We must therefore resort to some other method when the taper is greater than will be possible to do by setting over the tail-stock and throwing the centers so much out of line with each other as to wear them out of shape as well as to distort the form of the centerreamed holes in the ends of the piece of work. The taper attachment was devised to meet this condition and consists essentially of fixing to the bed a bar capable of being adjusted horizontally to any desired angle, and upon which is fitted a sliding block, moving with the lathe carriage, and so attached to the tool-supporting mechanism as to cause the cutting-tool to follow in a line parallel to the inclined bar as the carriage is moved to and fro on the bed. This is accomplished by different devices by the various lathe builders, whose efforts are usually directed to three principal objects: first, to so construct the taper attachment that it may be attached to any lathe without special arrangement or preparation of the bed. It was formerly necessary in nearly every case to have planed grooves or flat surfaces at the back of the bed for this purpose whenever a lathe was to have a taper attachment fitted to, or sold with it; second, to have the attachment so designed and constructed that it may be brought into use or detached with the least possible time and trouble; and third, that the parts are so constructed as to be as absolutely rigid as possible, particularly against any strain that would tend to throw them out of the predetermined line of inclination. Among the failures of taper attachments the most common is that of turning a taper so that the inclined line of the surface of the turned piece is curved rather than straight; sometimes convex and sometimes concave. The operator should always use special care to have the attachment perfectly rigid in all its movable parts, clamp screws tight and adjustments perfect; and that the cutting tool is set correctly at the height of the centers. F. E. Reed Company. designed and constructed by the F. E. Reed Company. The inclined guide-bar A is graduated on the end so as to show the amount of taper that is being turned. This bar is secured to a plate B, which slides upon the bar which is attached to the lathe carriage. The bar A, and plate B, are secured against longitudinal movement by means of the rod D, secured to the bracket E, clamped to the bed. By this means there need be no special preparation of the bed of a lathe in order to use the taper attachment. The carriage must, however, be of special construction. An intermediate slide E is proyided, with its rear end pivotally connected with the sliding block G, which travels upon the inclined bar A and thereby produces the variation of alignment in the travel of the cuttingtool necessary to turn a taper. It would appear that this attachment would not be of sufficient strength and rigidity to withstand the strain of heavy turning on a very severe taper, and still do accurate work. The R. K. Le Blond taper attachment is shown in Fig. 117. The slide supporting bracket A is attached to a dovetail formed upon or attached to, the bed. Upon it is swiveled the guiding bar B, upon which is fitted the sliding block C, pivotally connected with the compound rest shoe D, by means of the block E and connection F. Le Blond Machine Tool Company. This taper attachment is of new design, and is very rigid. It is changed from straight to taper work by simply removing a taper pin from one hole to another. The cross-feed nut is never disconnected and the compound rest can be moved by the screw when turning both straight and taper work. When extra heavy work is done the compound rest can be clamped to the taper attachment by a brace. By this arrangement all thrust is relieved from the screw, insuring greater accuracy. The guiding bar is graduated to taper per foot and is clamped in position by two T-slot bolts. A graduated screw adjustment is provided for accurately setting the bar. Figure 118 shows the Lodge & Shipley taper attachment. It is constructed in a similar manner to that made by the F. E. Reed Company, as will be seen by the engravings of the two devices. It is supported by the carriage, and the supporting bar upon which the inclined guide-bar A rests is secured against longitudinal movement by a rod D and bracket E; the latter clamped to the bed the same as in Reed's device. from straight to taper by tightening or releasing one screw on the dog. When attached for taper work the sliding shoe connects directly with the tool-rest and not with the screw, making its operation instantaneous. The nut is made to release and slide in a groove. The stud for the sliding shoe also engages into a groove, and to attach or detach requires nothing more or less than the releasing of one screw and tightening another, or vice versa. The cross-feed nut cannot fall over as in ordinary taper attachment when in use, because it is never disconnected. The bolt simply slides in a slot in the compound rest slide. Figure 119 shows the taper attachment made by the Hamilton Machine Tool Company. Like that made by the R. K. Le Blond Machine Tool Company, this has its supporting bracket carried upon a slide formed upon or attached to the bed. It is thereby rendered very rigid and substantial. The swiveling of the inclined guiding bar is similar to those already described, and the attachment of the connecting block to the cross-feed screw is easily understood by reference to the engraving in which it will be seen that the end of this block passes through the bracket attached to the rear It is supported by the carriage as in the Reed and the Lodge & Shipley designs, and travels with it and is therefore always ready for use. All operations necessary to use the attachment are made from the front of the carriage, and consist of first setting the taper bar to any desired degree, binding the sliding bar clamp to the back V, loosening the post screw at the end of the carriage arm which releases the cross-feed screw connecting block, and clamping the connecting link onto the taper-bar slide by means of the binding handle. The top link and the binding bolt, which is fitted to a reamed hole in the head of the block, furnish a double connection (and one that is absolutely rigid) between the two slides, preventing any back-lash. Figure 121 shows the taper attachment as made by the New Haven Manufacturing Company. The supporting bracket is adapted to travel in an upper and lower groove planed in projecting ribs on the back of the bed, thus rendering the support very rigid. The plate B is heavy and rigid and supports the swiveling guide-bar C, upon which slides the block D. In the later development of this device the dovetail is replaced by a square projecting rib. There is also an improvement in the connection E with the cross-feed screw, consisting of a heavy flat bar attached to the rear of the compound rest shoe and sliding through a strong and rigid guide block. Its rear end is pivotally connected with the block D, making a very accurate and rigid design. an adjusting member, it must be so arranged as to be detachable from its front bearing, or permitted to slide through it so that the inclined movement of the block on the guide-bar may gradually scribed. From the accompanying sectional view it will be seen that the rear end of the cross-feed screw is held by collars and journaled in a bearing, which is bolted to a bar connecting it with the sliding shoe on the inclined slide, so that the screw always moves with the bar and carries the compound rest with it. The tool is controlled by the screw at all times without interfering with the handle, the end of the screw telescoping into the sleeve on which is the pinion governing the power feed. Where it telescopes it is splined, and so the screw is under control of the operator, irrespective of the position of the tool due to the taper bar. When turning tapers the lower slide of the compound rest should be tightly clamped to the bar by the square head screw, shown in cut. Consequently there is no disconnecting of any of the parts when engaging or disengaging the attachment. Simply tightening the dog to the ways brings the attachment into service, and loosening the same disengages the attachment, leaving the lathe in proper shape for straight work; and in neither case does the use of the attachment interfere in the slightest degree with the full and complete use of the compound rest, should it be desired to face off a piece the full swing of the lathe. The construction further makes the attachment of exceptional value on lathes of extra length, in that it is available the full distance between centers by reason of its being bolted to, and traveling with, the lathe carriage. Holding a lathe tool. The old slide-rest. The Reed compound rest. The Lodge & Shipley compound rest. The Hamilton compound rest. The Hendey-Norton open side tool-posts. Quick-elevating tool-rest. The Homan patent tool-rest. The Le Blond elevating tool-rest. The Lipe elevating tool-rest. Revolving tool holder. The full swing rest. The Le Blond three-tool rest. The New Haven three-tool shafting rest. The Hendey cone pulley turning rest. Steady rests. Follow rests. The usual center rest. The New Haven follow rest. The Hendey follow rest. The Reed follow rest. The Lodge & Shipley follow rest. Their friction roll follow rest. Shaft straighteners. The Springfield shaft straightener. New Haven shaft straightener. Lathe countershafts. The two-speed countershaft. Geared countershafts. The Reed countershaft. Friction pulleys. Tight and loose pulleys. Self-oiling boxes. The Reeves' variable speed countershaft. Design of geared countershafts. Another form of variable speed countershafts. WHILE the old principle of holding a lathe tool in a tool-post or under one or more clamping bars is still largely used to securely hold the tool in a rigid position for performing its work, there have, within the past few years, been designed and come into use a number of very convenient, rigid, and practical tool-holding devices! special features commented upon. The old familiar slide-rest of our apprenticeship days still lives and is much used on hand lathes, bench lathes, and the like. Fig. 124 shows this form of turning rest as made by the F. E. Reed Company. Its construction is so familiar to every mechanical man that any description is unnecessary. Figure 125 shows a very efficient compound rest made by the same establishment to which attention is called as to the very rigid method of holding and clamping the tool by two heavy clamping screws. Also to the important fact that the tool is held at the extreme left-hand edge of the tool-holding device, in which position it is nearly always used. At the same time the entire top, tool-holding block is adapted to turn in any direction and to be securely held at any angle, thus making it invaluable for turning up to close shoulders or other obstructions at the right, and also when turning or boring inside work wherein it is necessary to set the tool nearly parallel to the center line of the lathe. LATHE DESIGN: TURNING RESTS, ETC. as above noted. This is very useful when heavy cuts are to be made upon work where rapid reduction of the amount of stock is called for, as the inverted back tool assists very much to balance the resistance by dividing it between two points. Figure 127 is of the compound rest and tool-holding device as made by Lodge & Shipley. It is neat and substantial and the forward prolongation of the shoe adds rigidity on heavy cuts. Both the upper and lower They will not require resetting perhaps more than once a year. The-tool clamping bars are arranged the same as those of the New Haven device, shown in Fig. 114. These slide loosely into the T-slots and may be removed and replaced by the arch clamps shown at A, A, the tool passing through one or both of these as occasion may require. They may be located at any desired position in the T-slots. This alternate device will be found very convenient on many unusual jobs as well as upon regular work. In Fig. 128 we have the compound rest with its tool-clamping device as made by the Hamilton Machine Tool Company. It is quite similar to that shown in Fig. 124, and made by the F. E. Reed Company, and possesses its good advantages of adjustment of the tool to point in any direction and to work up closely to a shoulder on either side. Lodge & Shipley make a similar device with the tool clamp almost identical with this one. Figure 129 shows the " open-side tool-post" made by the Hendey Machine Company. It is so arranged that it may be substituted for the slotted tool block and ordinary tool-post of their lathes. It may be swiveled to any desired angle and accurately adjusted Figure 130 shows the " quick-elevating" tool-rest made by the same company. The tool is raised or lowered by using the tool-post wrench on the short lever indicated in front in the engraving. It carries the old-style tool-post and is not, therefore, as rigid as that shown in Fig. 128. Figure 131 shows the Homan patent tool-rest, which is also made by the Hendey Machine Company, which has a screw adjustment as to height and a graduated base for setting to any required angle. It is, perhaps, the most rigid device of the kind using a piece of mechanism. In Fig. 132 is represented the Le Blond elevating tool-rest provided with a thread-chasing stop which is clamped to the dovetail upon which the rest slides. The device is very simple and effective for ordinary work. It would not seem quite so well adapted, however, for very heavy cuts on account of the fact that a heavy vertical strain would be rather severe on the inclined screw which holds the tool block up to its position. A very substantial device is shown in Fig. 133, and known as the Lipe elevating tool-rest. It is made by the Lodge & Shipley Machine Tool Company. In this device the tool-holder proper has formed upon its lower end a cylindrical portion which fits into the main casting and is secured thereto in any desired position by a strong clamping screw. It is adjusted vertically by a screw through the upper, and bearing upon the lower casting as shown in the engraving. The entire device fits upon the dovetail of the carriage in place of the compound rest. shown in Fig. 134, is made by the Lodge & Shipley Machine Tool Company, the R. K. Le Blond Machine Tool Company, and others. It is a very useful form and is equally adaptable to the carriage of an engine lathe or the slide of a turret lathe. when the clamping bolt is released to revolve the turret. It is interchangeable with the compound rest, simple in design, rigid in construction, and a great time-saver where the number of pieces to be used alternately. Its greatest advantage seems to be that by its use we practically add the features of a turret to the ordinary engine lathe and at a very nominal cost. It is true that we do not get the drilling and reaming features, but still many turret operations may be accomplished by its use. Figure 135 shows what is variously termed as a "full swing rest," or a " pulley rest," or a "wing rest," etc., by different lathe builders. First, because it is for turning work the full swing of the lathe and which the tool in the compound rest will not conven- iently reach ; second, because it is principally used for turning pulleys, and work of that nature, and third, because it is attached to the front "wing" of the lathe carriage. It is frequently made at an angle, inclining downward from the center of the lathe so that it may be made conveniently low to fit the low carriage of a large swing lathe and still have the general line of the tool on a radial line from the lathe center. This rest is practically the same as the plain tool block used on the carriage, with a base suitable for bolting down over a T-slot. It consists of a special base or slide, carrying three tool-holders, two in front and one in back. These may be advanced towards each other simultaneously by means of the cross-feed screw, in addition to which each has made by the New Haven Manufacturing Company. This is adapted to be located on the carriage of an ordinary engine lathe in place of the compound rest, and in addition to the three-tool slides, tool-posts, etc., in the the New Haven Manufacturing Company. last example there is a fixed standard in the center providing a center rest in which bushings of various diameters, to suit the different sizes of shafting, may be carried, and which serve to hold the shafting to be turned steady and firm for the action of the turning tools. In the last example this function must be The crowning of the pulley faces is effected by a taper attachment device, or its equivalent, at the back of the carriage. This may be effected by using straight tapers and making two settings, the inclined lines meeting in the centers of the pulley faces; or, the proper curve or " crown" may be given to the device by a curved guiding bar instead of a straight one. Under the general name of steady rests we may include any attachment to a lathe which has for its purpose or function that of furnishing a support at one or more points around the circumference of the piece being turned, opposing the pressure of the cutting edge or point of the tool and holding the work up to its original position and alignment as before the tool commenced cutting. Ordinarily there are two classes of these rests which may in a general way be called "center rests " and " back rests." The center rests usually have jaws bearing upon the work at three points spaced equally around the circle, while a back rest bears upon the work generally at the back and on top only. Sometimes such a rest form of a center rest, substantially as made by all lathe builders, the variations of design being in matters of detail, and not in general form, functions or methods of support or attachment. Figure 140 is of the follow rest as made by the New Haven Manufacturing Company. It will be noticed that the top jaw inclines to the front, so that, acting in conjunction with the back and the bottom jaw, it serves to embrace more than half of the circle of the work in the process of turning. The base of this rest is fitted to the With one Company. This rest has but two jaws, one at the rear and one over the work. Its peculiar feature is that the jaws may be removed and a special piece substituted, which is bored out to receive sizes of work to be machined. This feature will prove advantageous, particularly when a large number of parts, say shafts, are to be turned. exception it is the strongest follow rest made. Figure 144 shows the strongest follow rest made and is a product of the same establishment. Being provided with friction rolls for reducing the friction of the work, it is adapted to the heaviest work the lathe is capable of carrying. It is well designed for the purposes for which it is to be used and its parts are so made as to be easily adjustable to suit the work. Its special points of, construction are interesting as showing the thoroughness of the design. The two jaws carrying hardenedsteel rollers move in and out in a circular path, being actuated by a worm and knob. When set in any position they are adapted for a variety of diameters by simply moving the entire rest backward or forward. This is accomplished by connecting the rest to a screw which telescopes the regular cross-feed screw and is operated by the same hand wheel which sets the tool-rest. The position of the rollers is such that in approaching a shoulder they support the shaft upon the smaller diameter until the cuttingtool has turned a portion of the next larger diameter, when the position of the rest is changed to bear on that portion. Those having quantities of shafts, with a number of shoulders to turn, will recognize in this rest an attachment entirely new in principle and of the greatest importance in the saving of time. One of the indispensable accessories or attachments, if it may be so called, to an engine lathe, particularly one provided with a long bed, is some kind of a "straightener," by which not only rough bars of stock, but partly finished and finally entirely finished shafts, may be straightened. sPecial RoUer F The general plan of doing this work is to rest the shaft upon two points at some distance apart and then apply pressure on the opposite side, and at a point midway between these two points. These attachments or accessories are sometimes attached to the carriage of the lathe; sometimes mounted so as to slide on the V's of the lathe; again upon wheels that run in the space between the inner and outer V's; and in still other cases, for small and comparatively short work, they are mounted upon a bench. In this case they either have attached to them a pair of centers in which the work to be straightened may be placed and its correctness or incorrectness as well as the location and extent of the inaccuracies may be determined, or a pair of V-blocks in which the shaft may be laid while being straightened. In Fig. 145 is represented one of the latter forms of this accessory made by the Springfield Machine Tool Company, the uses of which will be readily understood by any mechanic. It is intended to be placed upon a bench and to be used when centering work by hand, and for straightening work centered by hand or machine, It is a familiar fact that work straightened in a press is more likely to remain straight in the lathe than when hammered straight, and that it is better in every way. The general arrangement of this machine is in itself very convenient, as any work within its range of centers may be tested and straightened without the unnecessary walking from press to lathe each time in straightening rough or finished work. This, however, does not limit the length of shaft that can be straightened, as any length may be operated upon, thus making it a great labor saver. In the tool-room it is especially valuable, not only for centering and straightening work in the rough, but for straightening pieces which have been accidentally sprung in use, or reamers, etc., which have been sprung in tempering. The blocks upon which the work rests when being straightened are removable to or from the screw and are kept in line by tongues, which fit the groove shown. The shaft is movable through the arm which supports it, being held in any desired position by the set-screw shown, which has a piece of brass over its points to avoid marring the shaft. The centering heads are clamped in any desirable position on the shaft, by the binding screw shown. The top of the arm which supports the shaft forms a pocket for chalk or other material used in marking. The center at the right is pressed forward by a spring and has a knurled head for drawing it back, both centers being provided with small oil wells. The body of the machine has three lugs cast upon it, by means of which it is bolted to the bench. The block which is on the end of the screw is of cast steel, case hardened, and the centers of tool steel tempered — the whole machine being so designed and constructed as to make it worthy of a place and useful in any tool-room or machine shop where much small work is done. Figure 146 shows the shafting straightener made by the New Haven Manufacturing Company. The base A has cast upon it at the rear a curved standard B, made very strong by proper ribs and extending over to the front. Through the top of this passes a vertical compression screw C, running in a long bronze nut and carrying loosely upon its lower end a V-block D, adapted to fit down upon the round shaft, which is laid into two other loose Vblocks E, E. To insure great rigidity when handling large work the forged stay rod F is provided, its head being held in a T-slot in the base casting and its upper end in a slot cast in the head and in front of the compression screw C, and secured by a heavy nut. At each corner of the base casting is bolted a leg G, G, G, G, carrying loosely journaled therein the shafts H, H, on the outer ends of which are fixed the wheels J, J, J, J, which are adapted to run in the spaces between the inner and outer V's of the lathe bed, which permits it to be moved to any point where its use may be desired. In ordinary cases a countershaft is a very simple mechanism. In the older form of engine lathes all that was necessary was a cone pulley identical with the spindle cone, and upon the other end of the shaft a tight and a loose pulley for receiving the driving-belt from the pulley on the main line shaft. Then, as threads required a backward motion of the lathe spindle, a second pair of pulleys was added and a cross-belt applied for that purpose. The shifting of these belts was too slow for practical work and clutches were used. These were of the old "horn clutch" type, making considerable " clatter" in their use and starting the work with too much shock. these in one form or another are largely in use at the present time. Up to a comparatively recent date the lathe had but two speeds, so far as the countershaft controlled it. One was the usual forward speed, the other a considerably faster speed backwards, mostly used in thread cutting. Occasionally, for special work, this "backing" speed was taken advantage of by changing the cross-belt for an "open belt," and thus getting another range of speeds. Doubtless this suggested the advantages of a regular two-speed countershaft which has now become quite common, as a convenient and economical method of adding another series of speeds to the lathe. There are now used on a number of popular lathes geared countershafts as well as various devices for producing a variable speed by a gradual increase or decrease of the number of revolutions per minute. This result has been sought by a number of different devices with more or less success. Some of them have had good features to commend them while others were more in the line of makeshifts that accomplished the results sought very inefficiently and partook too much of the nature of "traps" as understood by the machinist, and hence were comparatively short-lived and unpopular. Figure 147 shows a good example of the regular type of lathe countershafts. It is made by the F. E. Reed Company, and consists of the cone pulley, a counterpart of the spindle cone part, and two friction pulleys mounted upon the shaft, which is supported in two hangers having self -oiling boxes. The friction pulleys consist of the pulley proper A, which is turned on the inside of the rim for the reception of the friction band B, or has cast with it a rim projecting from the pulley arms and finished inside for the same purpose, as shown in the engraving. The friction band B is divided at one point as shown, the two loose ends having projecting lugs at b, 6, drilled for pivot bolts by which it is connected with the levers C, C, whose ends are adjustably connected by the screw and nuts shown at d. Sliding upon the shaft between the pulleys is the clutch collar E, whose horns e, e, are adapted to enter between the ends of the levers C, at /. These horns being wedge-shaped will, when thrust between the free ends of the levers C, C, spread them apart, and as their fulcrum ends are connected, and by means of the pivot bolts connected to the free ends of the friction band B, tend to extend the opening of this band, enlarge its diameter, bring it in contact with the inner surface of the pulley (or of the rim cast upon it for that purpose), and cause sufficient friction to transmit the required power. it is moved to and fro on the shaft, according as one or the other clutch is to be thrown into an active position and the lathe to be driven by the belt on the one or the other pulley. One of the pulleys carries an open belt and the other a cross belt. There are various forms of friction pulleys and friction clutches used on countershafts, but all are designed with analogous parts to the above and perform similar functions. Therefore there is no need for a detailed description and illustration of them. In all of them the pulleys run loose on the shaft, except when clamped to it by means of the friction device, the disc or friction band B, or its equivalent, being fixed to the shaft. In the center of the shaft between the pulleys is usually a sliding sleeve that operates the friction mechanism, as here shown, and by which it is connected to the shipper lever within easy reach of the operator. The tight and loose pulleys are still used on very heavy lathes, and in this case, when both the forward and backward motion is desired, there is one tight pulley a little greater in width than the belt, and on each side of it a loose pulley of double this width. The belts are so located that each is on one of the loose pulleys when the shipper handle is in its middle position. When it is moved to the right of this position the left belt is moved on to the tight pulley and the right belt travels to the right on its loose pulley. By moving the shipper handle to the left the reverse effect is produced, and the right-hand belt becomes operative. The pulley on the line shaft is, of course, as wide as all three on the countershaft. has formed beneath it an oil reservior B for holding a quantity of oil sufficient to last several weeks. Near each end is a groove containing a wick or strip of felt C, C, surrounding the shaft and reaching down into the oil reservoir B, by means of which an ample supply of oil is always delivered to the journal bearing. The wick may be introduced and oil supplied by opening the hinged covers D,D. by providing the return oil grooves E, E, "at the ends, which conduct the oil back to the oil reservoir. The design and arrangement is very simple and at the same time very effective. It is used with slight modifications for many similar purposes with like success. In Fig. 149 is shown the Reeves' variable speed countershaft, which has proven a' valuable device when the speeds required are not excessive. It is well adapted to nearly all machine-shop tools and by its use a great range of speeds may be obtained. It consists of two shafts B and C, journaled in the frame A, in the usual manner. Upon the shaft B is splined the rather flat cones D, D, and similarly connected to the shaft C are the cones E, E. These cones are adapted to slide freely to or from each other on their respective shafts, and their movement is governed by the levers F, F, which are fulcrumed at /, /, and pivotally attached to the hubs of the cones D, D, E, E, by suitable collars. The farther ends of these levers are pivotally connected to a screw G, by suitable nuts running on right and left threads, whereby the nuts may be drawn together or forced apart as may be necessary, carrying with them the ends of the levers F, F, and consequently the cone discs D, D, E, E, but by an opposite movement; that is, as the discs D, D, approach each other the discs E, E, recede from each other. Upon the end of the screw G is the sprocket-wheel H, from which a chain runs to another sprocket-wheel near the operator, who may handle it by means of a crank upon the shaft of the latter wheel. Running within the cone discs D, D, at one end, and E, E, at the other, is a series of wooden lags connected by a chain mechanism by which it becomes in effect a belt, the ends of the lags bearing against the inner, inclined surfaces of the cone discs. The length of the wooden lags being constant, it follows that as the cone discs are forced closer together the lags will ride up on a larger diameter, and simultaneously the cone discs on the opposite shaft will, by the mechanism described, be drawn farther apart, permitting the lags to run closer to the shaft and on a correspondingly smaller diameter. Now, as one of the shafts B, C, is driven by a belt from a pulley upon the main line shaft, while the other carries the pulley (in this case a cone pulley) driving the machine, the speed of the same may be varied at will, as one pair of cone discs are forced nearer together and the other pair farther apart, thus, in effect, changing their relative diameters and consequently their speeds. Geared countershafts are also used upon lathes for producing variable speeds. They depend, of course, upon the usual methods of Bringing into active operation pairs of gears of varying diameters by means of clutches, sliding gears, and similar devices. The noise of the gears is one great objection to their use. This has been partially avoided, or smothered, by enclosing them with a casing, which partially obviates another objection, that of throwing oil and dirt upon the floor, the machines, and the workmen. cones placed side by side but in reverse positions so that their adjacent sides were parallel. They were mounted upon parallel shafts, one being the driven and the other the driver. Motion was transmitted from one to the other by means of a short endless belt running between the surfaces, with the slack end hanging below them. This belt was controlled by a sliding belt guide by means of which it could be moved from end to end of the cones, whose varying diameters at the point of contact determined the speed transmitted from one shaft to the other. While this device was entirely operative and, with light loads, reasonably successful, it was not well adapted to transmitting any considerable amount of power, owing to the very small area of contact surface between the cones and the belt, the pressure upon which had to be excessive in order to transmit the power required even for light work. Unusually large cones would no doubt have added materially to its transmitting power, but as a practical mechanism it was not the success that its admirers hoped it would be. Special forms of turned work. Attachment for machining concave and convex surfaces. Attachment for forming semicircular grooves in rolling mill rolls. Device for turning balls or spherical work. Turning curved rolls. A German device for machining concave surfaces. A similar device for convex surfaces. Making milling cutters. Backing off or relieving attachment. Operation of the device. Cross-feed stop for lathes. Grinding attachments. The "home-made" attachment. Electrically driven grinding attachment. Center grinding attachment. Large grinding attachment. The Rivett-Dock thread-cutting attachment. WHILE an engine lathe will readily turn straight and taper work, and will "face" work at right angles to the center line of the lathe, or by means of the compound rest will turn or face at any angle, no means is provided for turning curved contours, as spheres, curved rolls smallest in the center, or largest in the center, as the case may be, or to "face up" convex or concave surfaces. These and many other forms must be made by the aid of some kind of a device built for the special purpose and usually known under the general name of a "lathe attachment." There are, of course, a great variety of jobs that can be economically performed on a lathe if we are provided with the proper tools and a suitable "attachment" for handling them. It is not proposed to give here a complete Jist of these ever varying kinds or types of lathe attachments or to exhaust the list of forms of work that may be machined by one or another of these devices, yet it may be interesting to present a few of the attachments that are most likely to be needed, and in a general way those that the machinist may easily make for himself. faces have to be machined to accurate spherical forms, the pieces being of such dimensions or material that the usual forming tools are impractical, or that the variety of dimensions would render them too expensive. In these cases a special device must be designed which will properly fulfil the conditions and be capable of adjustment within a reasonable range of diameters of the work and the radii of the curves to be machined. Forming Concave and Convex Surfaces. This may be accomplished by a special device attached to almost any ordinary lathe having a compound rest with a circular base, such as are now nearly always designed and built. The author has had occasion to design several of these devices, and the general form and arrangement of them has been as shown in the accompanying engravings, in which Fig. 150 is a plan of the lathe carriage showing the circular feeding device; Fig. 151 is a front elevation showing the method of varying the feed to suit the material to be machined; and Fig. 152 shows a modification of the device for a different form of work. this kind are most frequently for concaving vertical step bearings of various diameters from three inches up, and of radii varying in proportion, for forming concave and convex surfaces for ball and socket joints, for turning large spherical surfaces, and for forming semicircular grooves in rolls for rolling iron and steel bars. The construction and application of this device, as arranged on an ordinary lathe, is as follows. A machine steel ring A is forged, turned up, bored to a force fit to the circular portion of the compound rest. Its outer surface is properly formed for a worm-gear, its teeth cut and hobbed and it is forced on, and pinned if thought necessary. Engaging the teeth of this is the worm B, fixed to a shaft C, journaled in the brackets D, D, which are fixed to the carriage as shown. Upon the front end of the shaft C is the gear E, which may be removed and another size substituted for varying the rate of feed. By this arrangement the rate of feed may be conveniently changed to suit different diameters of work and materials of varying degrees of hardness, the same as the usual change-gears of a lathe. By releasing the stud-plate J, the gears G and H may be thrown out of engagement temporarily, while the stud-plate J and the brackets D, D may be easily removed altogether, if it is desired to use the lathe for ordinary turning for any length of time. As the feed for this device is derived from the cross-feed screw F, it is necessary to replace the usual solid nut in the shoe by a split nut (not shown) with the usual lever or eccentric device for opening and closing it as may be desired. A clutch device on the front end of the cross-feed screw F may be adopted, if desired, by having the cross-feed pinion N formed upon a sleeve projecting through to the front of the carriage and the gear G mounted upon it, and connected with, or disconnected from, the cross-feed screw F by sliding a double-faced clutch. In using this device for concave work held in a chuck or strapped to the face-plate, care must be taken to have the compound rest so adjusted on the carriage that when set parallel with the center line of the lathe its center will be exactly under that line, and that the horizontal distance from the point of the tool to the center of the compound rest will be the exact radius of the curve to be produced. radius of the convex curve. Figure 152 shows a compound rest tool block arranged for forming the semicircular grooves in rolling mill rolls. In this case the tool-post M may be made in two or more sizes, as some of the grooves are small enough to ne- ^g^f ' Attachment01 cessitate quite a small tool-post. If a lathe is to be used exclusively for this work the compound rest may be removed entirely and a circular base provided, having worm-gear teeth cut in its edge. This will be held down in the same manner as the compound rest, and have fixed in a raised central portion tool-posts proper for the work for which it is designed. In any event it will be found necessary to construct the device in as strong a manner as possible, in order to prevent, as far as may be the chatter or vibration of the tool. In Fig. 153 is shown a compound rest containing an attachment for doing this work. In Fig. 154 is a bottom view of the same for the purpose of showing the operative parts. tool block F. When in use the cross-feed is connected and started, and instead of moving the entire compound rest across the carnage as it ordinarily would, it moves only the rack C forward or back, which motion, being transmitted by the pinion D, and gear E, vided for in the ordinary attachments sold with an engine lathe, and where this work is not done regularly so as to warrant the designing and building of an attachment for the purpose, some do this. In the engravings, A is the bed of the lathe, B is the carriage, and C the compound rest. The curved bar D is attached to the bed by means of suitable brackets at each end, as shown in Fig. 157. This bar is made exactly to the curve which the rolls are to have, both on its concave and its convex edges, and serves as a guide for moving the compound rest forward and back so as to produce the proper curve in its travel across the work. To accomplish this travel the cross-feed screw nut E travels in a slot in the compound rest and may be fixed at any point therein by the screw F. Fixed to the rear end of the compound rest shoe C is a bracket G, in which is pivoted the small friction roller H, which bears against the edge of the curved former bar D. Attached also to the compound rest is the weight K, by means of a cord which runs over a sleeve L, attached to the lathe carriage. In the use of this device the clamp screw F is tightened up so as to fix the cross-feed screw nut E in its place and the rough forging for the roll turned down nearly to the finish size and form in the usual manner. The clamp screw F is then loosened and the fric- roller H. A similar attachment, or in fact this one, may be used to finish other curves, whether simple or compound, so long as the contour is made up of easy curves capable of being followed by the friction roller H, as shown in the engraving. Small pieces, say less than of forming tools. Another very desirable attachment for machining concave and convex surfaces is of German origin. Figure 158 shows a front elevation and Fig. 159 a plan of a lathe fitted with this attachment. It is very simple in its construction and consists of a radius bar A, which is pivoted at its rear end to a block D, and at its front end to the tool block of the compound rest at B. By reference to the plan in Fig. 159, it will be readily seen that as the cross-feed is operated, the compound rest must swing upon its center according to the radius of the bar A, and be governed by it. Surfaces. It is necessary for its practical working that all fits and adjustments must be nicely made and accurately set in order to have this attachment operative. Also, that unless the parts are all comparatively heavy and rigid, the cuts made would of necessity be light ones, otherwise the tool would be likely to have considerable vibration and leave " chatter marks" in the work. must project out farther from the center of the compound rest as in other attachments of the kind, since the radius bar has nothing to do with determining or governing the radius of the curve machined. attachment to the above, and of like origin, having for its object the machining of convex surfaces. This is a more complex matter, and the manner in which it is accomplished is at once ingenious and practical, and, so far as the author is aware, is new in this country. In the design of an attachment so arranged as to effect the proper movement of the tool to produce a convex curve, tliat is, a drawing back of the cutting-tool as it advances, it is obvious that the length of the radius bar must be the same as the radius of the curve which it is to produce. The bar A is made to this length and is pivoted at I to a slide K, free to move longitudinally on the lathe bed. The other end of the bar A is pivoted to a cross-slide F, which moves on a guide E, rigidly secured to the lathe bed. The carriage cross-slide has attached to it the roller G, which engages jaws in the slide F, and hence, as it is fed across the surface of the work, the slide F is carried along with the carnage cross-slide. The resultant effect of the movement of the bar A is to move the block K along the lathe bed, and this movement is transmitted to the carriage by means of the connecting bar L, this compound movement causing the point of the tool to describe an arc of which the length of the bar A is the radius. In this device, also, it is necessary to have all the parts strong and rigid, with bars, studs, bolts, etc., much larger and of better mechanical construction than those shown in the engraving, in order to insure accurate and well finished work as well that which will be economical in point of the time required to perform it. In making cutters for use in milling machines, gear cutters and the like, it is not sufficient that the correct form be given to the face or cutting edge of the teeth only. This form must be carried on to the back of the teeth so that in grinding the face of the teeth, when they have become dulled from use, they will still maintain their original and correct form. This would be a simple matter and might be readily accomplished in forming up the blank in the lathe previous to cutting the teeth, if it were not for the fact that there must be some "side clearance" allowed to the teeth. In other words, the teeth must be widest and the diameter of the cutter the largest across the cutting edge and the points of the teeth respectively, and the "form" carried back from this in a decreasing radius. There are various attachments in the market for performing this operation. The conditions of the case require that for each tooth of the cutter the forming tool must commence to cut at the cutting edge of the cutter, quickly move in toward the center until the cutting edge of the next tooth approaches, then fly back to the original position ready for cutting the next tooth. This motion is repeated for each tooth, and the tool-holding device must be likewise capable of being constantly adjusted to the depth of the cut as the metal is cut away so as to reduce it until the cut comes quite near the cutting edge. in Fig. 163. The construction of the device is as follows: Upon the small face-plate A of the lathe is fixed the actuating cam B, shown in Fig. 163. Upon the swivel bar of a regular taper attachment C is fixed the bracket D, in the upper end of which is journaled the friction roller E, which bears against the actuating cam B. The swivel bar is pivoted at F, as usual, and when used for the purposes of this attachment the clamping screws at either end (not shown) are left slightly loose so as to permit it to swivel slightly, and the friction roller E held tightly against the actuating cam B by means of a strong spring at H. K is the cutter to be "backed off," and L is the forming tool doing the work. The operation of the device is this. The swivel bar of the taper attachment forms a lever by which the motion derived from the actuating cam B is conveyed to the tool-holding device of the compound rest, the forming engine lathe having a taper attachment. Second, as the taper attachment swivel bar is used as a lever in obtaining the motion desired, this leverage may be as small or as great as desired by bringing the pivot bolts F and G nearer together or farther apart. Thus the amount of "clearance" given to the teeth In Fig. 165 is shown the plan, and in Fig. 166 the elevation, of a convenient and practical stop for the cross-feed of an engine lathe. It is not only very useful in thread cutting but in getting same setting. The construction of the device is as follows: Upon the cross-, slide A is fitted the cross-feed stop B, constructed as usual. Through this piece and into the tool block C passes the stop stud D, being fixed in the latter piece. This stud is threaded 20 to the inch, and the micrometer nuts E, E, graduated in 50 spaces, thus giving a reading of .001, upon which quarter thousands may be easily determined. The micrometer nuts are recessed on the side next to the feed stop B, and provided with a washer and short spiral spring. The washer is prevented from turning except with the nut by a small pin in the nut and fitting in a suitable notch in the edge of the washer. This washer is threaded the same as the nut E, and the action of the spring causes friction enough on the thread to prevent the nut from turning by any jar to which the lathe may be subjected. This construction also excludes dirt and takes up wear when the device has been in use for any great length of time. work may be accurately turned. When different diameters are to be turned, stop levers of varying thickness, one of which is shown at F, are used by placing them on the stud G, and secured by the nut H and its spiral spring. This stop must, of course, be exactly one half the difference between the large and the small diameter in thickness. In use it is turned down so as to come between the stop B and the micrometer nut E. When not in use it is turned over against the pin J. Two or more of these stops may be used without removing either of them, provided the one next to the stop B is used first and the others added successively to it, or vice versa. While such an attachment as the one here shown is a valuable aid to a careful operator, it is not an assurance that accurate diameters will be continuously turned out when the operator becomes careless and "runs hard against the stop," or is guilty of the opposite error of not coming closely up to it. Both these errors have caused a great deal of trouble to shop foremen. chanical accuracy is the great desideratum, the subject of grinding cylindrical surfaces has absorbed a great deal of attention. It was long ago realized that it was next to impossible to construct a lathe so accurate that it was possible to turn a perfectly cylindrical piece of work upon it. Grinding was formerly used principally in the construction of gages of various forms, but particularly cylindrical gages. As grinding machines were simplified and improved it was found that the grinding processes were continually becoming more economical, and that therefore the extreme accuracy which such processes made possible could be applied to many other kinds or classes of work. Grinding as performed in an engine lathe was accomplished by a " home-made" grinding attachment, more or less crude, and bolted down to the lathe carriage, tool block, or compound rest. The spindle carried a grooved pulley from which a round leather belt went up to a wooden drum hung up over the lathe and driven by a short belt from the lathe countershaft. This drum was as long as any grinding job was expected to be, since the round belt must needs travel to and fro upon it as the lathe carriage carried the grinding attachments over the length of the piece of work to be ground. wooden drum is fast becoming a thing of the past. In Fig. 167 is given a view of one of the electrically driven lathe grinder attachments made by the Cincinnati Electrical Tool Company. It may be held in the tool-post or tool-clamping device, and is entirely self-contained, the emery wheel being attached to the shaft of the small electric motor within the metallic case. It is driven by the current coming through an ordinary incandescent lamp cord. Its movements are regulated by the crank seen in front of the case, as well as by the cross and lateral feeding mechanism of the lathe. Its compact form, portability, and the convenience of attaching, using, and detaching, render it a very useful lathe grinder. It can be set at any angle so as to grind taper work as well as straight, and the centers of the lathe in which it is used. Hisey-Wolf Machine Company, and is shown attached to a lathe in the proper position for grinding the head-stock center. Like the last example it consists of an electric motor whose shaft carries the emery wheel. The shaft is arranged to travel endwise as is necessary in center grinding, and is operated by means of the double crank shown at the left. It is driven by the current from an ordinary lamp cord. Figure 169 represents a larger grinding attachment made by the same company and designed for larger and heavier work than either of the above devices. It is arranged to be bolted down upon the lathe carriage, or a block attached to it so as to bring its center at the same height as that of the center line of the lathe. It is driven in the same manner as the last two devices. The entire motor and case is attached to a square block having a vertically sliding surface planed upon it, and fitting the boltingdown and supporting bracket upon which it slides vertically, being adjusted as to height and held in any desired position by the double crank seen at the top. By extending the shafts of these motors, either temporarily or by having them so constructed when built, to the proper distance so as to carry the emery wheel at a considerable distance from the motor, they may be used for grinding the inside of cylindrical work, the longitudinal feed of the lathe being made use of to give the required travel for the wheel. Should the inside work be conical it is entirely practical to attach the grinder to the compound rest, set at the proper angle and the wheel fed back and forth quite as readily as on straight work. be conveniently performed. In fact there are hardly any of the ordinary grinding operations that are required to be done on centers that may not be performed by one of these grinders, even to cutters, reamers, and the like, by a little ingenuity in arranging for them. These points make such grinders of a great deal of value in ordinary machine shops and manufactories, and almost indispensable in the smaller shops where it is not always possible to get a regular grinding machine. The Rivett-Dock thread-cutting attachment, shown in Fig. 170, may with propriety be classed as a tool, but from its importance in design, use, and effect it seems to deserve being classed as an attachment and so it is made a part of this chapter. Its construction and operation is as follows : The angle plate A is adapted to be bolted down on the tool block of the lathe, and upon its upright face is fitted the horizontal slide B, which may be moved forward and back by means of the lever C. The slide B has pivoted to it the circular cutter D, whose ten teeth are shaped in the Attachment. form of the thread. However, the full form of the thread is only given by the last one used in cutting the thread, the others being gradually cut away so that the first one hardly more than marks the location of the cut, the design being to cut the full thread at ten cuts, each successive tooth of the cutter cutting a little deeper until the tenth tooth shall have but a trifle to cut to finish the thread. It will be noticed that the tooth marked 0 in the engraving rests upon a projection E, which supports it in its cutting position to act upon the piece F which is being cut. The cutter having made one cut is withdrawn from contact with the work by the handle C, by which motion the pawl G, pivoted at the top of the angle plate A, engages in the space between the teeth of the cutter D, and causes it to rotate to the left just far enough to bring the next tooth into the cutting position. The withdrawal of the cutter from the support E permits its revolution. The cutter is then thrown forward and the next tooth is ready for the cut. This operation is repeated until all the teeth have been brought into the cutting position and made their cut in succession, and the thread is completed. The important point accomplished by this device is that as there should be ten cuts made to complete a thread, the keen edge of the tool for finishing is liable to be lost in the earlier roughing cuts. With this device the roughing cuts are made with teeth designed for that work particularly, and the thread is brought to a state of completion by what is practically ten different tools. Hence a saving of time, both in cutting and in grinding tools, and the production of a smooth, accurately finished, and perfect thread. What a rapid change gear device is. The old pin wheel and lantern pinion . device. The first patent for a rapid change gear device. The inventors' claims. Classification of rapid change gear devices. The inventors of rapid change gear devices. Paulson's originality. "Change gear devices" by the author. Le Blond's quick change gear device. The Springfield rapid change gear attachment. Criticism of the device. The Bradford rapid change gear device. Judd's quick change gear device. Newton's quick change gear device. The Flather quick change gear device. BY the term "rapid change gear" we understand that the mechanism so denominated is one capable of performing all the functions of the former change-gears but without the necessity for exchanging one gear for another or one set of gears for another, that is, without removing a gear. their use was essential. In the old-fashioned " chain lathe," having a lead screw driven by "pin wheels" and " Ian tern pinions," which is illustrated and described in Chapter II, it will be seen that the builder had provided for changing the pitch of the thread to be cut by changing only one gear. This was about the year 1830. In 1882, George A. Gray, Jr., obtained a patent, No. 252,760, for a change gear arrangement whose principal feature was that only one gear need be removed and changed to cut any of the usual threads. The first effort in the direction of devising a rapid change gear mechanism was, so far as the United States Patent Office is concerned, made by Edward Bancroft and William Sellers, who on February 7, 1854, obtained Patent No. 10,491, for a device con- RAPID CHANGE GEAR MECHANISMS 195 sisting of two cones of gears intermeshing, one set fast to the shaft and the other set adapted to fix any single gear to the shaft by means of a pin passing through a fixed flange and into a hole in a gear or the hub of a gear; the set being made with telescoping hubs, the ends of all coming against the fixed plate. It is interesting, in the light of present developments in this line, to read the first claim of their patent, so prophetic of the developments to come, as follows: "The method of varying the motions of the mandrel or screw-shaft, or leader, by means of two series of wheels of different diameters, and all of the wheels of one series being connected and turning together, and imparting motion to all the wheels of the second series with different degrees of velocity, substantially as described." While a number of the later inventors claimed these same features of the mechanism and apparently considered themselves as the original inventors, it will be readily seen that the mechanical ideas involved in this invention anticipated their claims by a goodly number of years. In considering the question of rapid change gear devices it .will be well to adopt fome classification based upon their design or structural differences. We may then illustrate and describe these general classes by well-known or readily understood examples, whereby all devices of this kind may be more easily understood and their special features appreciated at their proper value. Third, those in which neither of these arrangements existed. Of the first class, using what has become well known as the "cone of gears," the most notable inventors are Bancroft and Sellers, Humphreys, Miles, Riley, Hyde, Joseph Flather, Peter and William Shellenback, Norton, William Shellenback, Herbert L. Flather, Ernest J Flather, Wheeler, Isler, Le Blond, Johnson and Wood. but this number did not seem to satisfy the ambition of some of the inventors, since one of them, Isler, used no less than six cones of gears. Usually these cones of gears were located under the head or in front of it, but sometimes within the bed. But Johnson, apparently being determined to have a cone of gears somewhere, places them on a loose sleeve running on the main spindle. It remained for Wheeler to find a new location for his cone of gears by placing them in the apron. Among all these devices, as in other spheres of mechanical effort, the inventors produced mechanisms ranging all the way from "good and bad, to indifferent." Of the second class, that is, those who located the gears on short shafts arranged in a circle, the first to devise this arrangement was Edward Flather, who obtained patent No. 536,615, on April 2, 1895, and was later followed by Benj. F. Burdick, William L. Shellenback, Edward A. Muller, and Herman R. Isler, in the order named, the latter 's last patent having been granted in 1902. Of the exceptional examples, included in class third, the most notable one is the invention of Carl J. Paulson, who adopted the very original method of making a series of rings fitting inside each other, cutting gear teeth on a portion of the face of each and arranging the proper mechanism to thrust out from its fellows, the gear having the desired number of teeth that might be needed. This was probably the most original of all the methods employed up to the present time. While this device was not a commercial success, it had a counterpart and was the prototype of a quite similar arrangement consisting of two sets of sleeves in line with each other and having teeth cut on their outer surfaces precisely as Paulson had done, and arranging them and their connecting gears in a more practical and operative combination. An interesting review might be written and illustrated of the various patented change gear mechanisms that have been invented since the days of Bancroft and Sellers, but it is hardly within the scope of this work to give the necessary space to this portion of lathe description. If the reader desires to pursue the subject in detail and to have dates, patent numbers, and illustrations from the drawings in the patent office, he is referred to a book by the author in detail. For the purposes of this work it will be sufficient to present a few of the more recent examples in this chapter and to call attention to the engravings of a number of others in other chapters wherein the lathes of prominent builders are illustrated and the change gear devices shown. Among these are the lathes built by Hamilton Machine Tool Company, Bradford Machine Tool Company, Hendey Machine Tool Company, Prentice Brothers Company, Springfield Machine Company, etc. The quick change gear device designed by R. K. Le Blond is an interesting example of this type of mechanism. Figure 171 shows an end elevation of this lathe, and Figs. 172, 173, and 174 some of the details of the gearing. The lathe, with the exception of these features, is the same as the standard engine lathe built by this company, and the headstock end is shown in Fig. 171, which gives a good idea of the exterior appearance of the change gear device. Gear Device. The line drawing, Fig. 172, shows the connection between the feed box and the lathe spindle. The spindle gear A drives gear D on the stud D1; through tumbler gears B and C. The tumbler gears are of the regular construction used for reversing the motion of the carriage in screw cutting, so as to cut either right or left hand threads, as required. Motion is transmitted from the tumbler gears through gears D, Ew G, and H, which latter is on the drivingshaft of the feed box. In order, however, to obtain a second series of feeds there is a telescopic slip gear located on the stud D1 which can be made to mesh with gear G in place of pinion ^ which is shown in mesh with gear G in the engraving. To accomplish this, G rotates on a pin in a quadrant Gt, which, by means of the clamping handle G4 and the stops G2 and G3 can be brought into the correct position for gear G to mesh either with pinion Et or gear F, as required. The hub of gear F is recessed so that it can be slid over pinion Ex, thus bringing this gear in the same plane with gear G. Gears D and F and the pinion Ex all rotate with the stud, which is journaled in a bearing in the head-stock casting. The introduction of the telescopic gear F makes a change in the feed ratio of 4 to 1. Figure 173 is reproduced from the patent specification and shows clearly the mechanism of the feed box. A is the driving shaft and B the driven shaft, which in this case is represented as being one end of the lead screw, but in the actual lathe is connected with the latter by suitable intermediate gearing. However, the principle of the feed changes is the same in either case. Shaft B carries a cone of gears and shaft A an elongated spur gear C, which is the driving gear of the mechanism. Surrounding this elongated gear C is a cylindrical barrel D, which serves the double purpose of a casing for the gear and a bearing for a sliding bushing E, by means of which the adjustment of feed is effected. This bushing carries at F an intermediate gear which at all times is in mesh with gear C and can also be brought a combined sliding and rotary motion on the barrel D. The portion of the barrel D which is toward the cone of gears is provided with a longitudinal slot, to allow the intermediate gear F to project through and mesh with gear C. The front portion of the barrel is provided with a series of holes, corresponding in number and position to the gears of the cone, so that the bushing which carries the intermediate gear F can be locked in its proper position for each gear by means of a spring pin, after the usual manner. The bushing which acts as carrier for the gear, and the barrel which encases the elongated gear, are clearly represented in the detailed view of the mechanism, Fig. 173. Figure 174 is a view looking at rear of the mechanism and its casing, and shows the modifications that have been made in the device to adapt it to the engine lathe. The cone shaft carries besides the eight gears of the cone, an additional gear, K, and below this shaft, which is marked B, is the shaft L, which is connected directly to the feed rod R, and carries a sliding sleeve S, on which are two pinions, M and N. In the position shown in this view power is transmitted from the cone shaft B to the gear N by means of the auxiliary pinion K, and as the sleeve S is splined to shaft L the motion is transmitted to this shaft and thence to the feed rod. By sliding the sleeve to the right, gear N no longer meshes with pinion K, but instead pinion M meshes with one of the gears of the cone, causing the feed rod to rotate at a faster speed. The lead screw T is driven from the feed rod by a slip gear W, in the usual manner. From the above description it will be seen that with the gear box itself eight changes of feed are obtained. The slip gear on the auxiliary shaft in the feed box makes 16 changes, and these 16 changes are again doubled by the telescopic gear on stud Dl; in 46 per inch, covering every standard thread, including 11J. This entire range of threads can be made without stopping the lathe or removing a single gear. The feeds are four times the number of threads per inch. It will be noticed that the compounding generally adopted on this style of lathe is done away with, and that wherever there are coarse feeds or heavy threads the increase comes directly from the 4 to 1 gear on the stud D17 speeding up the feed mechanism of the feed box in the same proportion, so that it is placed under no additional strain. Figures 175 and 176 illustrate the "rapid change gear attachment" of the Springfield Machine Tool Company's "Ideal" lathe. They make use of the design placed in the second class, or short shafts arranged in a circle. The change-gears are mounted in a gear box, shown at the lefthand side of the engraving, Fig. 175, the intermediate and headstock spindle gears being those ordinarily used. The cover of the gear box is rotated about a central stud, and the gears are carried on the inside of the cover, arranged in a circle concentric with the case, and this circle brings the change-gears opposite the end of the lead screw by revolving the cover of the case. Referring to Fig. 176, the small clutch C moves a telescopic extension of the lead screw and enters it into a hole in the changegear before the driving clutches between the change-gear and the extension come into contact. This device takes the bearing of the change-gear upon the extension for its support, and secures the change-gear to the lead screw as firmly as if fastened by a nut. In order to change the gear, the cover is revolved until the desired gear is opposite the center of the lead screw extension, when the small clutch is thrown. All of the eight change-gears are protected by the case except the top of the one which is in mesh with the intermediate gear. Attachment built by the Springfield Machine Tool Company. gear. These are housed in the gear cases shown at the extreme end of the head-stock. These are clutched to their spindles by slipping them on until their clutches engage the spindles, which have clutches with their end sections reduced, as in the case of the lead screw shown at F in the sectional drawing, Fig. 176. These gears furnish ratios of from 1 to 1, 2 to 1, and 4 to 1. The last two may be reversed and five speeds may be given to the fixed pinion driving the intermediate gear. The intermediate gear attached, and is removed from contact by raising the quadrant. This lathe has a range of threads from 2 to 56 per inch, and a range of turning feeds from 8 to 224 turns per inch, and all the changes for any of these feeds or threads may be made while the lathe is running. The objection to this device is the inherent weakness of the mechanism when the gears are arranged upon short studs or shafts set around a circle. These cased-in gears must of necessity be comparatively small and of narrow face. The teeth must, from the same conditions, be of fine pitch. Their support must be by comparatively small shafts. All these conditions render the mechanism structurally weak and less rigid than such a device should be to stand the strains of high-speed steel and modern cuts. The Bradford Machine Tool Company build an ingenious rapid change gear device which is shown in the accompanying engravings, of which Fig. 177 is a front elevation, Fig. 178 an end elevation, and Figs. 179 and 180 are sectional views. Figs. 178 and 179. This mechanism is contained in a gear box located in front of the bed, as seen in these two figures. It contains at A a cone of eight gears carried on a shaft for driving the feed rod and screw, and a sliding gear B, which acts as a driver for the cone and may be dropped into mesh with any one of the eight gears forming that member. The shaft-driving gear B carries loosely at the outer end three gears C, any one of which may be connected by a sliding key to the shaft. The three gears are rotated by gears At G will be noted a support for the driving gear which is formed dly on its shaft. The bracket G is bolted to the quadrant and the under part cut out to allow the intermediate gear to mesh of a shoe with a semicircular recess at the end which snaps under the heads of the locking screws, each screw head being of a conical form, as in the enlarged detail at P, Fig. 180, to fill a cavity in the under side of the controlling handle. The screws can be raised and lowered to allow the gear in the frame to mesh correctly with the gears of the case, thereby enabling the operator to use gears other than those ordinarily used, simply by adjusting the screws until the gears mesh properly. The rela- The quick change gear device shown in section in Fig. 182, and in front elevation in Fig. 181, is the invention of Joseph Judd, a draftsman employed by the New Haven Manufacturing Company. After much study of the subject in conjunction with the author, and after all former devices known in the patent office had been thoroughly investigated and studied and their features carefully classified, after they had in fact all been dissected, as it were, the question of obtaining the most simple and direct acting device was sought by the process of elimination of the undesirable features of other devices, and Mr. Judd hit upon the idea of making the faces of the gears composing the "cone gears" slightly inclined instead of straight, and thus make it in reality what it had been before in name, a veritable cone of gears. much more smoothly than many would suppose. The device includes a cone of gears composed of seven members L, and mounted upon the lead screw shaft P, to which they are fixed. Above this cone of gears is a pinion B, with an equally inclined face, and mounted upon the quill G so that it can be moved longitudinally to permit of its being engaged with any one of the seven gears below it. The quill or sleeve G is splined so that the pinion B may slide upon it, but must turn with it, in order to convey motion to the pinion B. The quill G is driven by the beveled pinion F keyed on the end. The pinion F, in turn, receives its motion from the beveled pinion E, which is mounted on the change-gear shaft D, and which carries at its outer end the change-gear C. The shaft H, supporting the quill G, is mounted in two eccentrics J, J, which give the beveled pinion B an in-andout motion relative to the nest of gears when manipulated by the handle K for changing the gear ratio. The sliding pinion B is moved longitudinally to the position indicated by the index plate for the desired thread or feed, by means of the knob M, and after being engaged with the 'desired gear is held in position by the pin N. This pin enters a hole marked with the number of teeth of the gear with which the pinion is engaged, being, for instance, 48 in the engraving. This provides quick changes by steps between and including the ratio 32 to 56. For wider ranges on the lathes of 32-inch swing and larger, a stud-plate R is mounted on the hub Q at the left end of the gear box 0, carrying gears so arranged that threads from 2 to 14 may Quick Change Gear Device. be cut, or feeds from 8 to 56 obtained without changing the position of the intermediate stud, the gears being so porportioned that as one is removed from the change-gear shaft E, it is used as the intermediate gear, and so on. and quickly effected. On lathes of 18 to 28-inch swing, inclusive, four additional changes are provided. This is effected by adjusting gear A longitudinally, permitting it to be meshed with either of the intermediate gears, the intermediate gear in this case being compound; and by mounting two gears at C on the change gear shaft. compound intermediate gear. A sliding spring key is provided by which either gear can be thrown into clutch with the shaft, thus giving the four changes without changing gears, the stud-plate having to be shifted on its pivot for two of the changes. This gives a range from 1 to 15 threads per inch and feeds from 4 to 60 per inch inclusive. By changing gear A, the other changes, of course, are readily obtained. tice Brothers Company. The inventor has directed his efforts to the production of an improved change speed gearing of suitable form for economical manufacture and installation and which would be conveniently handled to actuate the feed rod or the lead screw. lows : The lathe carriage may be actuated by the usual feed rod A or may be driven by the lead screw B when screw cutting. There is a bearing in the rear end of the head-stock for the shaft C and this is driven from the spindle through the usual tumbler gears arranged for the handy reversal of the shaft. There are three gears fastened to the shaft C and there is a sweep D having a transverse slot fitting a bolt threaded into the end of the lathe bed. The sweep or stud-plate can be turned about its supporting hub and fixed in any position to which it is adjusted. By this means an intermediate gear can be put in mesh with any two of the six gears shown, and this forms a very convenient arrangement for a three-speed connection and avoids the use of an interchangeable set of gears at this point, the change being made with gears already in position for the purpose. width than any of the six gears with which it meshes. A countershaft E carries a series of gears. On the shaft F is a forked lever G, and between the arms of the latter is a pinion J with a key engaging the keyway cut in F. An intermediate gear in mesh with the pinion, is journaled on the stud extending between the parts of the forked lever G. The end of this lever is turned upward and is provided with a handle. A pin H is fitted in the ear extending from the lever and is controlled by a spring-pressed trigger carried by the handle. A cover plate is secured to the bed to form a box over the changegears, and the front lower edge of the plate, as illustrated in Fig. 183 has a guiding rib supporting the pin H. A series of holes is bored in the cover plate and in line with the gear-wheels. The forked lever G and the pinion J can be slid along the shaft F, and opposite the proper gear the handle may be lifted and locked in place by means of the pin H. The end of the countershaft E projects through the right-hand journal and has a keyway cut in it. A slip pinion K is fitted on this projecting end and has a key engaging the keyway. A gear N is on the end of the lead screw B. The gear L has a hub fitted in the bearing supporting the left-hand end of the feed rod A. The gear at the end of the rod A. A spring normally keeps the toothed parts in contact. An adjustable collar on the feed rod enables the carriage to be automatically stopped when a predetermined point in the travel is reached. The slip pinion K on the end of the countershaft E can be adjusted to engage either the gear N on the lead screw or the gear L that actuates the feed rod. assembled on the bench. The lead screw and the feed rod can be applied to the machine by bolting the brackets which support the lathe to the bed. Then the supporting bracket is put in position so that the triple gears will come in the same plane with their mates, and that the countershaft E will be in line for the engagement of the slip pinion K with either gears M or N. most of their devices are and have been for many years. From here the motion is transmitted by a train of gears, which will be described later, to the gear D, which drives shaft A in the feed box. This shaft is cut for a part of its length with teeth to form a long pinion, and on this portion slides the lever E. The shaft B carries the cone of gears usual in arrangements of this kind, and pivoted in the lever E, but not shown in any of these cuts, is the usual intermediate gear, which meshes with the teeth cut in the shaft A, and can be brought into mesh with any of the series of gears on the shaft B. The locking pin F locates the lever in each of its different positions by entering into the appropriate hole drilled in the face of the gear box. G is a steel plate fastened to the lower edge of the box, and provided with a notch to match each locking pin hole. A projection on the inside of the lever E enters one of these notches, and prevents the lever from being shifted along the shaft until the intermediate gear has been dropped clear of the gears on the shaft B. A new feature in this device is the fact that means are provided in the gear box for giving three different speeds to the feed rod or lead screw for each position of lever F. The shaft C has turning loosely upon it two gears, H and J, whose hubs are cut to the form of clutch teeth. Between these two gears is a third one marked I, which has clutch teeth at both ends of its hub, and is splined to the shaft, but free to move endwise. An endwise movement is given to it through the lever K; which projects through the top of the box. When in the position shown, the motion is evidently transmitted from shaft B to shaft C through the gear I, and its mating gear in the series on the shaft B. The gear I may be thrown either to the right or left, and thus be disengaged from its mate, but connected by the clutch teeth on its hub with either of the gears H or J. As these are run by their corresponding drivers at different rates of speed, each position of the lever E, by shifting lever K, will give three different speeds, or twenty-seven in all. This is the usual way of changing the turning feeds in the shop of the manufacturer; the lever E being located at a suitable station, the roughing and finishing feeds are obtained by the lever K. The gear I has a spring pin in its hub which engages suitable depressions in shaft C, and thus prevents the lever K from being jarred out of position. The shaft C is extended through the gear box and carries a pinion and clutch L, which may be moved to the right to engage the clutch on the lead screw, or moved to the left to mesh with the gear on the feed-shaft. The 27 feeds and threads mentioned are further increased to 54 by means of a sliding gear which meshes with the wide-faced gear D and is moved in or out by the projecting hub seen at M. Suitable gearing in the case N alters the ratio of rotation for these two positions. While this arrangement gives 54 feeds varying from 7 to 448 per inch, the threads from 2 to 128, the range is still further extended to permit the cutting of odd threads, metric pitches, etc., since the gear D may be removed and one of any suitable number of teeth inserted in its place. Lathe tools in general. A set of regular tools. Tool angles. Materials and their characteristics. Their relation to the proper form of tools. Behavior of metals when being machined. The four requisites for a tool. The strength of the tool. The form of the tool. Degree of angles. Roughing and finishing tools. Spring tools. Tool-holders. Grinding tools for tool-holders. Dimensions of tools for tool-holders. The Armstrong tool-holders. Economy of the use of tool-holders. High-speed steel. A practical machinist's views on high-speed steel tools. Conditions of its use. Preparing the tool. Testing the tool. Speeds and feeds. Much difference of opinion. Grinding the tools. Amount of work accomplished by high-speed steel tools. Average speed for lathes of different swing. Speeds of high-speed steel drills. Mr. Walter Brown's observations on high-speed steel. Its brittleness. Its treatment. The secret of its successful treatment. Method of hardening and tempering. Method of packing. Making successful taps. Speeds for the use of high-speed steel tools. Economy in the use of highspeed steel tools. Old speeds for carbon steel tools. Modern speeds. Relative speeds and feeds. Modern feeds for different materials. Lubrication of tools. The kind of lubricant. Applying the lubricant. Lubricating oils. Soapy mixtures. Formula for lubricating compound. Improper lubricants. Various methods of applying lubricants. The gravity feed. Tank for lubricant. Pump for lubricant. Power for driving machine tools. Calculating the power of a drivingbelt. Impracticability of constructing power tables. Collecting data relating to these subjects. Flather's " Dynamometers and the Transmission of Power." Pressure on the tool. Method of calculating it. Flather's formula. Manchester Technology data. Pressure on tools. WITH comparatively slight exceptions the ordinary lathe tools are of the same form as those used in the time of the old chain lathe with a wooden bed. While the modern machinist has found some new shapes for special work and has been provided with all sorts and forms of tool-holders, and it is probable that many new and perhaps improved forms will be brought out in the future, the same old forms will probably be used for a considerable part of lathe work as long as there is a lathe to use them on. A set of fourteen of these time-honored tools is shown in Fig. 187, which are usually known by the following names, the numbers given in the engraving being referred to : is quite apparent also from their form. The question of the proper angles to which lathe tools should be formed is an important one and there are a good many theories in relation to the subject. It is a matter of continual discussion among shop-men who are inclined to disagree very much on the subject. It is altogether probable that this disagreement is not so much that the question is one impossible of solution as it is that each man determines the question for himself from the standpoint of his own experience and with the range of material with which he has to work: otherwise, with the conditions which govern the work under his observation. are these: We have ordinarily to handle such materials as tool steel, machine steel, steel castings, wrought iron, cast iron, bronze, brass, copper, aluminum, babbitt metal, hard rubber, vulcanized fiber, rawhide, and a number of others constantly coming to hand. These substances as here mentioned give a very wide range to the kind and shape of the tools that it will be proper to use. But there are varying degrees and conditions in the same material that still further complicate the question. Steel may be hard and brittle, or it may be soft and tough. It may be of any percentage of carbon up to and perhaps over one hundred points, and still we must make a tool to cut it. but, of course, in a much less degree. The alloys of copper commonly known as hard bronze, nickel bronze, gun metal, brass, yellow brass, and so on, through an almost endless variety of mixtures, will require almost as many different forms as must be used in turning the different grades of steel. materials with which we have to deal. In a general way we may say that the quality of the material we have to cut will influence the results in two ways : first, as to whether it is hard or soft, and second, whether it is crystalline or fibrous. Its varying degrees of hardness or softness determine whether much or little can be removed in a given time; or, what amounts to the same thing, whether the speed of the cutting shall be fast or slow, and whether the feed shall be coarse or fine. Its crystalline or its fibrous nature will make considerable difference in the top angles of the tools, and this will be readily seen in the tendency of the crystalline metal to break up into small chips, while the fibrous turnings will curl off into spiral or helical shavings. Therefore the fibrous material will have the sharper angle than that designed for the crystalline structure of metal. Of course all tools must be harder than the material they are to cut; at the same time they must not be so hard as to be brittle, or be made of a quality of steel that becomes brittle when hardened, but tough and strong and capable of maintaining their cuttingedge uninjured during their ordinary use. The fact that they do this will be best evidence of the correctness of their angles, provided they have done the proper amount of work, that is, have been run under satisfactory conditions of speed and feed. In the proper design of a tool, with angles to suit the work, there are four points to be remembered, namely: cutting capacity, that is, as the machinist would say, to "dig in"; the right angle of relief or clearance; proper strength; and durability or lasting quality of edge and point. That these are not simply distinctions without a difference is seen if we analyze the question a moment. Cutting capacity is the tendency to dig into the work, to bury itself in the metal. This is directly opposed by the greater or less angle of clearance or relief. The tendency to bury itself in the work is due to the "rake " and the top angle, but principally to the rake in a slide tool and the top angle in a cutting-down tool. As to the proper strength. The tool will be much stronger with more obtuse angles, yet more obtuse angles will be to the injury of its other qualities. Again, if the point or the edge is too keen, that is, at too acute an angle, its strength and durability are both jeopardized. Side Tool. Hence we are forced to the conclusion that the form of the tool is not only largely governed by the kind and quality of the material to be acted upon, but is in itself, by reason of the conditions of its construction and use, very largely a question of compromises on the one side or the other, and frequently on both. It will be seen that the clearance angle may be anywhere between a vertical line and 10 degrees from it. The face angle may have a like variation although we frequently see tools having an angle as great as 25 degrees. The "rake" or top cutting angle will be any angle from horizontal to 25 degrees, seldom more. In a general way it may be said that in cutting steel the softer the material the more acute may be the angles, and that for very hard steel the angles must be very obtuse. tools for steel and brass are discussed, " Whatever you do for a steel tool, do the opposite for a brass tool." (The metals mentioned being those to be machined, of course.) And this is literally true as far as angles are concerned. the workmen get their tools from the tool-room ready ground, the tool angles are the same for both metals and of all degrees of hardness, unless the foreman has special work to do requiring a special form of tool. Another set of tool angles are used for brass and bronze. When bronze is very tough as well as hard, a special form of tool will be required, and this will sometimes very nearly approach the form of a tool for turning steel, including considerable rake and top angle. Often a diamond-point tool is used. (See Nos. 4 and 5 in Fig. 187.) Tools are of two general classes according to their use, that is, for roughing and for finishing. The former must be made mostly for strength and are intended for deep cuts, coarse feeds, and slower rates of speed; while the finishing tools are for high speeds, fine feeds, and shallow cuts. Fine feeds are not, however, always used, as it is a common condition to use very light, scraping cuts, with a broad tool and a coarse feed. This is notably the case in finishing the inside of engine cylinders. The author has seen such a cut of nearly an inch feed, the tool being very carefully ground and acting more as a scraper than a cutting-tool. In this case the angles of the tool were very slight. A being nearly straight across, or parallel with the FIG. 190. -A Spring Tool or "Gooseneck." surface of the work. When there seems to be too much " spring" in the action of the tool, a small block of wood is inserted at B, to furnish some support for the cutting edge and prevent chattering. This form of tool is not nearly as much used as formerly. In fact the later development of turning tools has been toward more simple forms, which, under modern conditions, seem better adapted to the general line of work. increased. This innovation was started before the advent of the now wellknown " self-hardening," or " high-speed" tool steels, that have so changed machine shop conditions and which followed the introduction of "Mushet" steel a number of years ago. These tool-holders have been made in great variety and profusion and much ingenuity has been displayed in producing what each maker thinks is at once the most convenient, the strongest, and the best. Some of these holders use tools made by simply grinding a slight notch in the bar and breaking off pieces of the proper lengths, whose ends are ground -to the desired form, while others require a special form of cutting-tool that is usually drop forged, fitted, and tempered. It is fair to assume that on general principles and for general use the tools made from a bar will be the most useful, since it is always the most convenient. The machinist having a bar of tool steel of the proper size may produce tools of any form, and to fit any of his different tool-holders, according to which is best suited to his particular work. The matter of grinding these tools is a very simple one. The regular shapes, and about all the shapes that will be needed, are shown in the engraving, Fig. 191, in which the angle is specified. Thread tools may, of course, be added to the list, and so also may some forms of inside boring and threading tools. The dimensions of the steel used for these tools for light lathe work is T3B inch and J inch square. For medium lathe work, T56-, f, T76, and J inch square. For heavy lathe work, f , f , f , 1, 1J' inch square. speed or self -hardening steel. As between the leading brands there is very little difference in efficiency; some excelling slightly in one respect, or upon one class of materials to be machined, while another brand seems to work better on another. favorite forms. Probably there are more Armstrong tool-holders used than any other, and in Fig. 192 is given views of their usual forms. Their uses are plainly indicted by their names and forms. In Fig. 193 is shown at A a good form of tool-holder for regular straight work. At B is shown a tool-holder and tool for cutting threads. It will be seen that as this tool is of parallel form throughout its length, it is only necessary to grind off the top as it becomes dulled, and raise it to the proper position to compensate for the amount ground away, in order to always have a fresh surface and of proper cutting form and angle. and re-forging of tools is reduced to a minimum, and in fact may be almost eliminated, the tools to be so treated consisting only of a very few special tools for special jobs that cannot be conveniently reached by such tools as may be used in the tool-holders, is amply sufficient to warrant their use in every shop. quired can be produced is also an important reason for their use. Another reason is that when the shop is once equipped with tool-holders, the cost for the steel for making the tools is very slight as compared with the heavy forged tools formerly used. The modern demand for high-speed steel for lathe tools and its high price makes it necessary, from reasons of economy, to use small tools; hence tool-holders. In reference to the use of high-speed steel in a very large and general way, for all classes of work upon which it is possible to use it, there seems to be no doubt. It has been proven many times, in many places, under many conditions and on almost every conceivable material that has to be handled in machine tools, that it has "come to stay" and that any information regarding it is of practical use. and observing machinist whose name, unfortunately, is not at hand so that proper credit can be given him, are here introduced as being valuable in this connection, and practical from the machine shop point of view: "The first thing is to make up one's mind as to the quality or kind of steel to use, which means to be satisfied with the steel which has been found to work best in one's own shop. This has been a difficult matter for superintendents and foremen to decide, because it is so hard to discover the best way to determine which steel will do the most work, and experience has taught most of us that any of our high-speed steels, when properly treated, will do considerably more work than the machine is capable of. "I do not think it advisable to have too many different kinds of stock in the works ; results depend entirely upon the way of forging and treating the tool. If the tool-maker is familiar with one or two grades of the best high-speed steel, and the quality is found satisfactory, and bringing about the best results that the machines can stand up to, these are the steels that should be adopted. "Each of these steels must be treated differently, and if the toolmaker succeeds in treating one grade properly and understanding it thoroughly, it means much time saved and better results in the shop. " In introducing the use of high-speed steel in a shop, like everything else that is to be a success, one must start right. That is, the work should be undertaken by some responsible person — superintendent, foreman or speed boss, in other words, the man who is responsible for the work turned out in the machine shop. All tools, of course, have some particular way of treating, which should be understood by the person in charge. Now it is 'up to the forger/ "The person in charge should see that the tool has its proper treatment, as success in most cases lies with the treatment. When the tool is finished, and the superintendent or foreman is satisfied that it has been properly treated in accordance with directions, it is ready for grinding and for making a test. It should be ground on a wet emery wheel, and care taken to heat the tool just so it can be touched with the fingers. it into? ' In most cases when a new tool is tried, it is put in a lathe, to do turning; so naturally the superintendent or foreman would pick out the best lathe that was in the shop, i. e., the lathe that was considered to have the most power. "Being now ready to make the test, it is generally tried on steel; that is considered by most superintendents and foremen the severest test to make. Take a piece of steel of almost any diameter, and of the quality most used in the shop, and prepare to take the cut. It seems to puzzle most every foreman to know just what to do and where to start. I speak now of what I have seen, and of the men who are sometimes sent by the steel makers to demonstrate the use of their steels. • "I think the proper way is to get at least one dozen shafts of a standard size that are used in the regular line of product, and to first look up the exact time it took to finish or rough off the previous lot; then to determine about what percentage of time would be considered a fair gain to warrant adopting the steel, based on the price per pound of the steel being used. Let it be based at 25 per cent, which I find in most shops can be accomplished, and the lathe be speeded up faster than when the last lot was turned, starting with the same feed and about the same cut, which most any lathe will stand. The superintendent finds, after he has roughed off about two or three pieces, that the tool seems to stand up all right. "The next step is to find out about the speeds and feeds. The first thing is to increase the feed with the same speed the machine is running at. In most cases which I have seen, after the tool has traveled a certain distance the cutting edge would break or crumble, and the foreman would say, ' Just as I expected. All this highspeed steel will do the same thing!' forgetting he had just been doing over 25 per cent more work than ever before, without the least bit of trouble. "Now the tool is taken out and looked over, and it is found that a portion of its cutting edge has been broken off. Here is where most foremen make a mistake; they take the tool back to the forger or tool dresser to have it re-dressed and treated over. If it is only broken off slightly and can be ground, even if it take ten or fifteen minutes to grind, it should be done by all means. My but care must be taken not to overheat in grinding. "The tool is now put back in the lathe, which is started again; and generally, to one's astonishment, it will be found that the tool will stand up all right. One should not be too anxious to break the tool again (!), but should turn up two or three more pieces with an increase of feed, keeping a record of the time it takes to turn up each piece. "Once convinced that the tool will stay up all right with the increase of feed, the foreman can increase the speed one step on the cone. About the time this is done, it is found either that the belt slips, the lathe is stalled, or the countershaft will not drive. (It is my opinion that in most all machines which have been built up to a year or so ago the countershafts are not strong enough in comparison with the machine tools.) Now, no doubt if these things had not occurred the tool would have done better; but in this case, reduce the speed, and finish the twelve shafts, which it will probably be found can be done without grinding the tool. "When the shafts are all roughed off and finished, the foreman will find to his great astonishment that by actual time the lathe has produced over 25 to 40 per cent more work than ever before. I allude to the lathe using most all ordinary tool steels. "At this point it is up to the superintendent to see just where he is at, and he finds in looking around his shop that there is hardly a machine that he can't speed up, but he also finds that the speeds on the countershafts are all too slow. This means that he has either got to increase his speed by increasing the main line, or buy new pulleys to increase his countershafts. "In most instances it is advisable to increase the speed of the countershaft, but by doing this he generally finds that the countershaft will not stand the speed. If the machines are not too badly worn out, and he is satisfied that he can get at least 25 per cent more work out of the tool by increasing the counter speed, by all means let him get a new countershaft and treat each machine this way. "No doubt the reader will know the results that some of us have arrived at in the last two years. In regard to cutting speeds and feeds there has been and always will be difference of opinion, and it is almost impossible to determine the right feeds and speeds, whether it is for steel or cast iron, and for the operations of turning, planing, or milling; the work varies so in different shops, that is/regarding the construction of different pieces, the amount of metal there is to remove from each piece, and how accurately the work has to be done. " There is no doubt in my mind that the makers of high-speed steel have awakened the management of different shops, and it is surprising the amount of work which can be accomplished even with the old machines, with very little redesigning. There is no question but that the machine shops which do very heavy work have not the necessary power for the use of high-speed steels, as the power should be used if the machines are old ones. " Referring again to the question of grinding, I wish to state that this is a very important factor in the use of high-speed steels. I have seen much damage done to the tools, in many instances making it necessary to treat them over, and, as we all know, this takes much time. My recommendation for grinding is to let one man grind all the tools, and be responsible for them. When a lathe hand or a machine hand wants his tool ground, he simply gives it to the man who is responsible, and gets another the same size and shape, these being always kept ground and ready for service. In this way the tools are kept uniform and ground alike. "In reference to the amount of work that can be accomplished on different machine tools, the writer finds that the feeds have been altogether too fine on most makes of machines up to the time that they were redesigned for high-speed work. Now it has been demonstrated that high-speed steel has come to stay, and we all know that it works better on roughing work than it does on finishing. If most of the product of the machine department is to be turned, it has come to the point where the majority of work must be ground; and this is the only way to get good and accurate work, especially where the strains of the cut spring the work. Moreover, as it is not necessary to straighten the work to any great extent, it certainly means a great saving, as many of our readers know. The writer is not a builder of grinders, but merely speaks of the saving it has been on his own work. high-speed steel. Every lathe has a face-plate about the diameter of the swing or very near that. Take the peripheral speed of same by feet per minute; the use of a Warner cut-meter will give you the speeds instantly. This is one of the handiest little tools that can be obtained, and no machine shop is complete without it. The speed must be taken with the belt on the largest step of the cone, with the back gears in. The speed of the following sizes of lathes, taken from a large face-plate with the slowest speed, I find to work very well, and considerable saving has been effected even on old lathes. Of course the feeds will have to be determined by the amount of power available: f-inch diameter, speed 290 r.p.m., 2\| inches deep in one minute. 1 -inch diameter, speed 250 r.p.m., 2J inches deep in one minute. IJ-inch diameter, speed 220 r.p.m., 2J inches deep in one minute. IJ-mch diameter, speed 200 r.p.m., 2 inches deep in one minute. If-inch diameter, speed 185 r.p.m., If inches deep in one minute. IJ-inch diameter, speed 175 r.p.m., If inches deep in one minute. "These speeds are all based on a peripheral speed of 65 feet per minute. High-speed drills have done somewhat better than this, however, but taking into consideration the time of grinding, I find that this speed is a good average during a day's run." Continuing the discussion of high-speed steel it may not be amiss to say that it is yet in its infancy, and as far as can now be judged it has a most brilliant future before it. It has its shortcoming as every comparatively new product has, but when we consider how long it took to develop "machinery steel" to its present condition, we must admit that high-speed steel has a record that its friends may be proud of. One of its good friends, Mr. Walter Brown, has given us in the columns of " Machinery" some excellent ideas on this subject, in which he has taken much interest and of which he has made many valuable observations and suggestions. Among other good things be says : "In spite of its shortcomings, however, it is very evidently the cutting-tool material of the future, both because of its superior qualities, all things considered, and of the likelihood that most of its present failings will be overcome as manufacturers get a better knowledge of its nature and behavior. "The chief difficulty in the way of its use now is its exceeding brittleness. Many a user has become discouraged with the result of a few experiments and has, because of finding that it lacked the 'toughness of other steels, discarded its use entirely. More experience would, if intelligently obtained, have demonstrated without question the great value of this new product of the metallurgist's skill. "The question of brittleness is largely a question of treatment; and intelligent experience will very largely obviate the difficulty so that it will be tough enough to stand up under any proper conditions of work. Every tool-dresser knows how to handle carbon tool steels, and is guided by his knowledge of their qualities at different temperatures as indicated by their varying colors. When he gets a high-speed steel he naturally treatsvit much as he would carbon steel. "This is where most of the trouble begins. The smith must learn an entirely different set of color values and methods of treatment. He thinks that if he has succeeded in getting a hardness greater than that of his file, he has done his job. That, however, has nothing to do with the fitness of the tool. I have known cases (with a certain make of steel) where the tool would do the best work while still soft enough to take a good Swiss file. "In other steels a similar degree of softness, or even a degree of hardness much greater than that of ordinary steel, would not work, the tool ' gumming up' and rapidly burning up. The whole secret lies in getting the tool to such a heat, in the process of hardening, that the constituent molecules are mobile, and then 'drawing' it to the right point. "When the tool-maker has mastered this secret, he can produce a tool of high-speed steel as tough as any of carbon steel. The mastering of it is largely a matter of experience. Our own experiences have been so interesting and successful that1 I have thought they might prove of help to others, and I submit them herewith. "The tools should be placed in a pipe or box, well surrounded with small pieces of coke, the packing case then being sealed up with fire clay. Small holes must be left for the escape of gases, otherwise the clay will blow out. The heating furnace should have been previously heated to a white heat. The packing case is left in the heat from one to three hours, according to size. When removed from the furnace, the box should be as near the bath of fish oil as may be, so that there will be no unnecessary delay in bringing from the gases of the packing case to the bath. "Exposure to the air not only causes scale, and therefore variation in size, but tends to affect the precision of the hardening process. Observance of this caution will prevent a variation of more than a thousandth of an inch in tools of moderate size. Carbon steel usually varies several thousandths as a result of hardening. "The method of packing will depend somewhat upon the shape of the tool. It is important to pack in such a way that all tools packed in one case be so placed as to be handled very quickly, and at once plunged into the bath, to prevent scaling by reason of contact with the air, as explained above. In case of milling cutters and key-seat cutters, a good way is to suspend them all from a rod, each separated from its neighbors by a slight space, sufficient to allow a free circulation of oil when plunged. Neglect of this caution will be very likely to cause cracks, from the unequal contraction of the cutters, the outer edges only being brought into immediate contact with the bath, and therefore shrinking more rapidly than the interior parts. "For taps, drills, and similar shaped tools, this hardening leaves the steel too brittle, and as soon as the tool has become a little dull it breaks off. To avoid this the tool can be drawn as can a carbonsteel tool. But here, too, a new set of color scales must be learned. The blue heat of carbon steel is not enough of the high-speed steel. The heat must be carried on until the metal reaches a greenish tinge. It is then allowed to cool in a dry place free from air drafts. "It is now much tougher and softer than before. In case it needs still further softening, it can be done by reheating, bringing it to a faint red, dull enough to be perceptible only in a dark place (an empty nail keg is convenient for this use) and then cooled as before. We have made taps as small as -^ inch in diameter to be used in an automatic nut tapping machine, about the hardest work to which a tap can be put, with gratifying results. "In the test three taps cut 92,000 nuts, an average of almost 31,000 nuts per tap; with carbon steel taps we cut 6,000 nuts per tap. No effort was made to speed up the machine, the test being one of durability only. The carbon steel taps cost about ten cents, and the high-speed taps about forty, or four times as much. The latter, however, cut about five times as many nuts. Besides this, there is also to be taken into account the more important saving in the time used formerly for stopping the machine, and removing and grinding taps, which is five times as great when carbon steel taps are used. "This is not mentioned as a particularly demonstrative test, but merely to show that high-speed steel can be profitably used for small tools, if properly treated. Another place where we are using high-speed steel with profit and satisfaction in small tools is in drills. The saving here is very marked; but the statements and claims of several makers of such drills is not verified by our experience. We find that we can run such a drill at about double the speed of the ordinary drill, and at the same time cut more holes. "Makers of the new steels are in the habit of making large claims as to speeds attainable. We have tried about every such steel on the market, giving each a thorough test. Our experience usually bears out the moderate statements, and sometimes the extravagant ones, put forth by some makers as to what is possible. For minute peripheral speed, from a rod of machine steel. "Such speeds are possible for short periods; but whoever buys a rapid cutting steel with the expectation of maintaining such speed will be sadly disappointed. With a fine feed, even four hundred feet per minute can be cut under very favorable circumstances. But think of the chip that comes off! In case of steel the chip is no such thing as we are accustomed to, breaking into short pieces and dropping into the box below. "At a speed of, say, two hundred feet per minute, the chip comes writhing and twisting, almost red hot, in a continuous length, shooting here and there, everywhere but the chip box; and quick must be the workman that manages to keep well out of the way of it, for it 'sticketh like a brother' when once he gets tangled in it. " Possibly, in time, a way will be found to take care of such chips. Until this is done, however, a moderate speed is most desirable. We find that on steel, where there is no considerable thickness of metal to remove, a speed of one hundred feet a minute is very satisfactory. This allows taking care of chips, and the tools stand up well under it. In turning gray iron, where the scale is to be removed, about seventy feet per minute is giving us the best results. Naturally, however, there being so many different kinds of materials to work up, and each one of these varying more or less themselves, there can be no set rule for speed. Each job will work out a rate for itself. The main thing is to get out the job as fast and as well as possible, and at the same time to lose as little time as may be in grinding the tool. "Another word about the saving to be effected. This will depend among other things upon the number of machines that are run. If only one machine runs on a job, there will not be a saving of two thirds simply because the speed is trebled. It must be remembered that perhaps 50 per cent of the time for doing a job on a single machine is used in jigging the piece and setting the tool. "The high initial cost of the new steels has made it necessary to devise means for reducing the quantity of metal in the tools used. The result has been the production of some very ingenious schemes for holding cutters. The lathe tool holder is, of course, familiar to all. Milling cutters, hollow mills, and reamers with inserted teeth, are scarcely less familiar. It is now true that we are making all these tools with inserted cutters of rapid cutting steel at less cost than the old carbon steel tools. At the same time they are doing from three to ten times the work, and at a much greater speed." The question of speeds and feeds is an important one in connection with that of lathe tools, whether the old carbon steel is used or the new high-speed steel known as self-hardening is that selected. As has been said in the observation on the form and qualities of tools, a great deal depends, not only on the kind of metal worked, but also on the quality of the particular kind that is to be machined. With the old form of tools made from the old carbon steels, cast iron was turned at a speed of from 20 to 25 feet per minute; soft steel, 25 to 30 feet; wrought iron, 35 to 45 feet; and ordinary brass at from 50 to 100 feet. With the present tools and methods such speeds are considered child's play, and the speeds at which different materials are turned, assuming a medium grade of metal, will more likely be given as or in fact bear any fixed relation to them. A prominent writer on this subject says that: "An important point is, that other conditions being equal, the increase of speed involves a diminution of feed. Hence it is not possible to reduce the question of speeds and feeds to formulae, or tables." This is hardly correct as to the fact of the inverse relation of speeds and feeds under varying circumstances, as the same author admits further on by saying: "Each class or job must be settled by or finishing cut. Some practical observations in point may not be amiss, as they are taken from actual practice and may be held as good mechanical data, with the use of high-speed steel. 20 to 40 per inch. Finishing cuts on soft cast iron, with a wide point, practically straight-faced tool with corners slightly rounded, the feed may be, for soft cast iron, from 1 to 4 per inch. be from 4 to 8 per inch. In these different cuts the speeds may be substantially as stated in the table given above, except the last, in which case the speed must be very much slower, less than half the speeds there given. Further than these figures it will be found difficult to set down a range of speeds and feeds that will be of any practical value. It must be left for the superintendents, foremen, and mechanical engineers in charge of work to determine these facts and to adopt such standards as may be found by actual experiment is most satisfactory under the circumstances and conditions governing the work, and which will, of course, include a careful study of the materials that are to be machined. The lubrication of tools has a very considerable influence upon the performance of lathe tools, and when used should materially increase the output of the machines by permitting faster speeds, heavier cuts, and greater feeds. Lubrication prevents the friction that otherwise attends heavy cutting, and therefore prevents heating to both the work and the tool. A steady stream flowing upon the cutting-tool will tend to carry away such heat as will, to a certain extent, always take place. Naturally a well lubricated tool will last longer in proper condition for cutting than one that is not lubricated, as the friction of the metal across the edge of the tool will be much less. As to the kind of lubricant to be used, it will vary with the kind of metal to be machined and its condition. Cast iron will require no lubricant. In fact it is probable that any kind of a lubricant would be a detriment rather than a help when turning cast iron. The same may be said of ordinary yellow brass castings and the usual kinds of sheet brass, brass rods and tubes. But for bronze, and similar alloys containing a considerable portion of copper, it is always advisable to use a lubricant, and, if very hard and tough, oil is the proper lubricant. This is also true of the turning of wrought iron, malleable iron and steel, or steel castings. As to the kind of oil most appropriate, it is well known that lard oil leads all others. ,0n account of its high price, this oil is often replaced by a mixture of lard and other animal oils or fish oil. Mineral oil should not be used, as it fails to prevent the heating of the work and the tool. Neither should a mixture of animal and mineral oils be made for such a purpose. For reasons of economy certain soapy mixtures are sold for these purposes. These are mixed with water to a consistency to flow freely, and often answer the purpose nearly as well as oil. They are more convenient and cleanly to use around the machine. While it is convenient to purchase these compounds, a good one is easily made by boiling for half an hour or more one half pound of sal soda, one pint lard oil, one pint soft soap, and water sufficient to make twenty quarts. The soda should first be dissolved in the water, and the oil and soap added successively while the mixture is hot. Should the mixture prove too thick to run freely from a drip can, or to pass through a lubricating pump, hot water should be added until the desired consistency is obtained. Any purchased preparation of this kind that has a tendency to rust the cast iron parts of the machine should be rejected, as it contains either acid or an excess of soda, and sometimes, even potash, all of which will be detrimental to the work and the machine as well as to the efficiency of the operations being performed. Trouble clogged by the undissolved portions of the compound. As to the means used for applying the lubricant, the first and most simple is a small, round bristle brush. This will answer well enough for short jobs and for small parts, but for larger work is rather a tedious process, requiring the constant attention of the operator, and thus limiting him to the work of a single machine. Oil is the lubricant usually applied with a brush. The gravity feed comes next in order. This is simply a "drip can," which is supported by a rod attached to the rear of the carriage or compound rest. This can, holding a quart or more, is provided with a bent tube having a faucet, or stop-cock, attached at or near the bottom. It is kept filled by the operator pouring from a tray under the work such portions of the lubricant as drip off the work. As a constant stream of lubricant is always desirable, however large or small it may need to be, a small pump is resorted to. A small tank is located under the machine or near it, from which the pump draws its supply of the lubricant and forces it up through a jointed or flexible pipe to the tool. The tank is usually made of cast iron, and is divided into two parts by a vertical plate reaching up to within two or three inches of the top of the tank. The lubricant, as it flows from the tool, carries with it many fine chips which flow into one of these compartments, where the chips fall to the bottom while the lubricant fills the compartment, flows over the vertical plate and into the other compartment where the clear liquid is drawn off by the pump. This method is an improvement over the perforated metal plate or the wire gauze strainer. Usually these pumps and tanks may be purchased independently of a machine and attached in any manner desired. As the pumps are usually of the rotary type, they may be driven from a small pulley on the countershaft of the lathe if no special provision for them has been made on the machine itself. While these lubricating devices are usually more appropriate for a turret lathe or similar machine than for an ordinary engine lathe, yet the class of work and the kind of material to be ma- machine. It will be often desirable to know the power which is being consumed in operating a lathe on certain work for which data is required. For most purposes this can be sufficiently approximated by calculating the power of the lathe from the width of the belt and its speed in feet per minute. For such purposes it is usual among mechanical engineers to consider that a one-inch belt traveling a thousand feet per minute will transmit one horse-power. This will give us a key to the entire calculation. For instance, if we have a piece of work 6 inches in diameter, we know that for every revolution it will move through a distance equal to its circumference, that is, 18.85 inches. If the cutting speed is 30 feet, or 360 inches, we can easily calculate that it must make 19.6 revolutions per minute. If the back gear ratio of the lathe is 12, and we are using the back gears, the cone must make 12 times as many revolutions as the piece of work, or 235.2 revolutions per minute. If the step of the cone on which the belt is running is 19 inches, it will be practically 60 inches circumference, or 5 feet, and therefore the belt speed will be 1176.6 feet per minute, or 1.176 horse-power for every inch in width of belt. Now, assuming that the belt is 4 inches wide, we shall be using 4.7 horse-power, if we force the cut up to the full capacity of the belt to drive it. to transmit double the power. It would be very interesting if we could make a table giving the power required to drive the lathe on all different diameters, for all different kinds and qualities of metal, when turned with all different forms of tools made from all different kinds of tool steels, and on all different designs of lathes. It would, however, be an almost endless task and would be of very little practical value when it had been accomplished. The conditions as noted above, and which are all practical, every-day conditions, are so many and so various that there would be found very seldom a repetition of them in regular machine shop work. be necessary to observe conditions, ^to collect and record data, and to make calculations from these individual conditions and circumstances, in this particular shop. And this table, while of considerable value in this shop, and interesting to any mechanical engineer or shop economist, would not be a safe guide in any other shop until corrected by the data made by an extended series of observations, the time and expense of which would be nearly equal to those necessary to produce the original table. These remarks are not intended to discourage the desire to obtain such data. It is always commendable to search, observe, calculate, and "dig out" all these and similar facts relating to the performance of machine tools, and such habits should be encouraged in all who have to do with this work. No labor of this kind is lost, since every item of such work adds to the sum total of our information and enriches the subject for us, and gives us a more secure and confident hold on the important questions involved in it. A still further reason for such observation and the recording of the data thus obtained is the constant changing of the design of machine tools, the constant changing of material to be worked upon, the infinite number of forms of the parts to be machined, and the thousand-and-one differing circumstances of their manufacture. A recent writer whose name, unfortunately, is not given, in discussing the question of the power required for taking the cuts in different metals and the pressure in the tool says: "The most complete information on this subject is contained in Flather's 'Dynamometers and the Transmission of Power/ in which are collected data from many tests upon various kinds of machine tools. Since the introduction of high-speed steel, however, conditions have changed so much that the deductions from the tables mentioned would be to a certain extent incorrect. Probably the most satisfactory way to determine the pressure on a tool is to obtain this from the power required to drive the machine when cutting. Knowing the horse-power, if we multiply this by 33,000 we have the foot pounds per minute; dividing this by the cutting speed in feet per minute will give the pressure on the tool, neglecting the power lost in overcoming the frictional or other resistances in the machine itself. In tests upon high-speed cutting steels at the Manchester Municipal School of Technology, to which we shall presently refer, it was found that the power absorbed by the machine varied greatly with the temperature of the bearings and also with the speed. After the bearings become warm, the oil is more viscous, which makes an appreciable difference; and tests also show that it sometimes requires more power to run a lathe at high speed — as would be the case when filing a piece of work — than when taking a heavy cut at a slow speed. These facts indicate the degree of care necessary in arriving at reliable information upon the subject of your inquiry. Referring to the tests in BLatJ^gr'.8 text-book, we find the following formulas deduced from average results, which give the horsepower required to remove a given weight of cast iron, wrought iron or steel : moved per hour. "The most complete information upon power required with high-speed steels is that obtained by the English tests at the Manchester Municipal School of Technology. These are very elaborate and cannot easily be summarized, but the following statement of results will answer our purpose and throw some light on the subject: Heavy cut 198 5.5 "Applying Flather's formulas to these results we find that for steel the horse-power required would be 4.6, instead of 3, for light cutting; and 19.6, instead of 15, for heavy cutting. In the case of cast iron we find the horse-power would be 1.1, instead of 1.7, for light cutting; and 5.15, in place of 5.5, for heavy cutting. This would indicate that Flather's formula for steel allows more power for soft steel than was shown to be actually required by the English tests, and will probably give ample power for a considerably harder apply very closely, but giving results slightly too small. From these comparisons it would seem that the rule to multiply the weight of metal removed per hour by .04 would give a safe value for the horse-power for both steel and iron. Further examination of the results of the English tests shows that with the steel more metal was removed per horse-power when taking a heavy cut than when running at high speed and taking a light cut; while when cutting cast iron this condition was reversed. It was found that the cutting force did not vary mucn with the speed, because at high speed the cuts were light while at low speed the cuts were deeper and taken with a heavier feed. The pressure on the tool increased very rapidly as the tool became dull; but when the tool was in good cutting condition the following pressures were recorded: For hard cast iron 82 "It will be noted in reviewing these pressures that those for steel appear to be a little irregular, but they are recorded in the results of the experiments cited." This interesting subject might, with profit, be pursued much further and such investigation is earnestly recommended to the seeker after facts in this respect; but the limits of space will not permit a more elaborate exposition in this chapter. Prime requisites of a good lathe. Importance of correct tests. The author's plan. Devices for testing alignment. Using the device. Adjustable straight-edge. Development of the plan. Special tools necessary. Proper fitting-up operations. Leveling up the lathe for testing. An inspector's blank. The inspector's duties. Testing lead screws. A device for the work. A micrometer surface gage. Its use in lathe testing. Proper paper for use in testing. Test piece for use on the face-plate. Testing the face-plate. A micrometer straight-edge. Allowable limits in testing different sized lathes. Inspection report - on a lathe. Value of a complete and accurate report. BEFORE entering upon the consideration of the work of the lathe in all its varied phases and by the different methods that are appropriate for the many classes of work with which we have to deal, it would seem proper to discuss the methods of testing the lathe to ascertain its condition before putting work upon it. In so doing we shall be able to direct attention to some of the prime requisites of a good lathe and how to ascertain whether the particular lathe in question possesses them or not. We should know whether the main spindle is exactly parallel with the V's or not, both in a horizontal and a vertical plane; to know whether the carriage is at exactly right angles to the V's or not; to know whether the head center and the tail center are exactly in line or not; and so on through the many requisite features of a good lathe; •one that will "turn straight, face flat and bore true." The plan that will be given and the tools and implements used were devised by the author, who used them in testing hundreds of lathes and found them accurate and practical, and confidently recommends them to any mechanic having such duties to perform and a desire to perform that duty in the best and most accurate facturer, purchaser, and user. At this time, when such extreme accuracy in machine tools is demanded, when it may be said that the machine tool that could be sold as a fairly good tool ten or even five years ago could scarcely be given away now; when a buyer critically tests every requirement of the machine he buys, and oftentimes almost literally dissects it, it becomes necessary to adopt such methods and to provide such appliances as will insure a practical demonstration of its accuracy. Although the lathe is the oldest known machine tool we have, we are far from knowing all its capabilities and possibilities as yet, and each year finds some added good points brought out by the many workers in the field. the hands of the manufacturer. And that condition or those qualities which are important to the builders of machine tools are equally important to the purchaser who "pays good money and expects a good machine." The success of the mechanic who runs the machine, and the officials under whom he works, is a matter that has its important bearing upon the question, since we cannot expect a high degree of efficiency without good machines. tail spindles. An arbor, A, is preferably constructed of thick steel tubing with hardened steel plugs fitted to and forced into the ends, which have been previously bored out. This arbor is ground true with the usual projections, to prevent it from dropping out, and controlled by the thumb-screw c. Passing through the mortise a is a bar C, carrying at its outer end a micrometer screw device, represented in detail in Fig. 197. This consists of a bar D, of in the usual manner. The knurled thumb-screws d, e, fix these joints in any desired position. The use of this apparatus is as follows: Place the arbor in the lathe, slide the collar B up near the mortise a, clamp the micrometer device in the tool-post in the position shown in the upper figure in Fig. 198, and bring the point of the micrometer screw down upon the collar B, rotating the latter slightly to get the pressure just right. Slide the collar B to near the tail-stock, move the carriage down opposite to it and note if the micrometer screw rests upon the collar as before. If not, note on the graduations of the micrometer the amount that the tail spindle is high or low. It is assumed that the centers have previously lined fairly well sidewise. To set them accurately the same method as above is used, setting the micrometer device as shown in the lower figure in Fig. 198. Supposing that the centers of the lathe have been found to line vertically and horizontally correct, we now desire to know if the back box of the head spindle is set in exact prolongation of the line of centers. Place the bar C in position and clamp the micrometer device in it, as shown in Fig. 195. Slowly revolve the tram device thus arranged, setting the micrometer screw to the nearest point in contact with the face-plate. Continue the revolution and with the micrometer screw ascertain the exact variations of the face-plate from a perfect right angle with the line of centers. Having determined the accuracy of alignment of the lathe, we now desire to test its accuracy of facing — whether it will face up a piece concave, convex, or exactly true, and to note the extent of the variation. Figure 199 shows an adjustable straight-edge for this purpose. H is a permanent straight-edge used only for adjusting the one applied to the face-plate. This is shown at K and has its lower edge formed as shown in the section at the right, and has three blocks, I, m, and n, sliding upon it and fixed at any point by the thumb-screw t. These blocks are set at such distances apart as will accommodate the size of the face-plate to be tested. The block n carries a fixed point, about -f$ of an inch in diameter at the point. The block / carries a plain screw point s, used to adjust the device so that the micrometer screw r of the block m may be adjusted at zero. To adjust these set the micrometer screw at zero and then bring the screw s up or down till all these points rest properly on the permanent straight-edge. To apply the device to the face-plate to be tested the surface w is placed downward on a short arbor, taking the place of the head center of the lathe and projecting about 6 inches from the face-plate. This not only furnishes a convenient support, but keeps the contact points at right angles to the face-plate. Keeping the points of the block n and the adjusting screw s in contact with the face-plate, the micrometer screw r may be set to the convexity or concavity of the plate, and the error read on the micrometer graduations p, in thousands of an inch, or even much finer. A subject thus important will necessarily have its developments and these should be made by actual experience in a practical manner. In developing these methods of testing a lathe, further instruments were necessary and are therefore described. In some cases where there are two methods of test, one of these was used and in some cases the other. Again, both were used and checked against each other. The special tools necessary for determining the accuracy of an engine lathe must, of course, be accurate and reliable, but they need not for this reason be elaborate or expensive, as the illustrations accompanying this article will readily show. Their description and use will be fully explained as the process of inspection is proceeded with in the matter which follows. It is assumed that the lathe bed, as well as the head-stock, tailstock and carriage, have been properly planed, the V's shaped to the proper angle, and that the V's of the bed have been scraped straight and true, removing as little of the metal as possible. The head- stock, tail-stock, and carrriage should now be carefully scraped to fit the V's of the bed. Their fair bearing may be easily ascertained by rubbing on a little of a mixture of the dry, red pigment commonly known among painters as " princess red," or some similar dry color, mixed with a small portion of any oil that may be convenient. The above color will be found to have this convenience: it will show almost black where the pressure is very severe and correspondingly lighter where the contact is less perfect. The scraping should be continued until the contact spots do not exceed f inch from center to center, and the inspector should assure himself of this fact before these parts are finally fixed in position. The carriage should be' run back and forth along the length of the bed to detect any slight curves that the bed may have taken since it was planed, and if any are found they should be corrected by scraping. Of course the bed should be carefully leveled up and kept so during the time this scraping and fitting is going on. When the lathe is finally "set up" or erected, great care should be taken to have it in as firm a foundation as is possible, and this requirement becomes all the more important as the lathe is larger and heavier. The bed should be carefully leveled both longitudinally and transversely, applying the level to the tops of the V's at points not over four feet apart for large and heavy lathes, and not over three feet for small and medium sized ones. If this is not carefully attended to it will be difficult to determine with any reasonable degree of accuracy whether or not the lathe will bore truly, as a slight change in the tops of the V's, throwing them out of a true plane, will defeat the test. in the same plane. Before proceeding to further describe this system of lathe testing, attention is called to the accompanying blank report for properly recording the results of the inspection. It will be noticed that it is quite thorough, but a long experience in machine tool work brings us to the conclusion that there is not a superfluous observation or requirement in it. And it is recommended that lathe builders send a signed copy of this report to the customer who purchases the lathe, for his information and guidance There are many items of an inspector's duty not here enumerated which, in a shop properly arranged and managed, will have been attended to as the parts are being made and assembled. This relates only to the performance and outward condition of the lathe when ready for its final inspection. and may be tested for accuracy of thread by the device shown in Fig. 200, in which A is the lead screw to be tested, upon which is applied the main frame B of the device, supported by its capped bearings C, D, the former just fitting over the top of the thread and the latter having either a babbitt metal lining cast upon the thread or being provided with a split sleeve in which this babbitt nut is cast. The latter arrangement is best, particularly when lead screws of different pitches or different diameters are to be tested. bored large enough to allow of a suitable bushing being introduced. The frame B of the device is extended to the right to form a grooved support for the adjustable arm E, secured by the bolt e and adjusted by the screw /. This arm is extended to form a graduated segment at g. The leverage and graduations are so arranged that thousandths of an inch are indicated by lines, and a much smaller fraction may be readily perceived. In using this device that portion of the frame B between the bearings C, D, rests on the top of the compound rest, the lathe being arranged for the same pitch as the lead screw to be tested. The screws holding down the caps of the bearings C, D, are set up just close enough to insure a proper fit. The object of using a babbitted nut in the bearing D and applying the indicating lever F at some distance from it is threefold. The influence of the lead screw of the lathe in use is not felt, there is very little friction on the point of the indicating lever F, and the relative inequalities of the thread of the lead screw to be tested are rendered more obvious. Another very important and useful instrument in lathe testing is the micrometer surface gage, which is shown in Figs. 201 and 202, in which all principal dimensions are given. The base A is of cast iron, the supporting rod B and the pointer b are of Crescent steel drill rod, and the other parts (excepting the spiral spring) are of tool steel. Its construction is readily under- The lathe being ready for testing and the face-plate having been faced off, we begin with the test for alignment, as shown in Fig. 203, which is a rear elevation of a lathe ready to be tested, and Fig. 204 a plan of the same. To ascertain the vertical alignment of the head spindle we place an accurately ground and properly fitted test bar A in the center hole of the head spindle and place the micrometer surface gage on the lathe V's as shown in Fig. 203, first applying the pointer b at a point near the face-plate and then near the outer end of the test bar, as shown by dotted lines, using the micrometer-adjusting nut L to ascertain the difference, if any. To render the touch of the pointer more sensitive a slip of paper should be drawn carefully between the test bar and the pointer. The best paper for this purpose is a hard calendered linen typewriter paper, three thousandths of an inch thick, as this paper runs very uniform in thickness. If the inner and outer V's of the lathe are not of the same height, a parallel bar should be laid across the V's and the micrometer surface gage placed upon it. In any event much care should be exercised to be sure that the gage base sits fairly on its support, as a slight scratch, or a burr, or the least bit of dirt, will defeat the object of the test. The vertical alignment of the tail spindle is tested in the same manner, as shown in Fig. 203. It may also be tested by bringing the pointer down on the spindle itself, when it is run back into the tail-stock, and again when it is run out as far as it will go. It sometimes happens that we shall get a different result by sliding the tail-stock to a different position on the bed. In this case we will probably find some inequality in the V's to account for it. To test the lateral alignment of the head spindle, a bar of the size of the ordinary lathe tool, with its front end bent to a right angle, and provided with a micrometer head, is placed in the compound rest as shown in Fig. 204, and the reading made in a manner similar to the last test. The lateral alignment of the tail spindle is tested in a similar manner, moving the carriage to the desired point. To ascertain the accuracy of the center hole in the head spindle, we may use our micrometer at the end of the test bar A, as shown in Fig. 204, and by turning the spindle a quarter of a turn at each reading we may ascertain its accuracy with certainty. The foregoing tests would seem to be sufficient to insure the correct boring of a job on this lathe. But it must not be forgotten that the error detected by the test, as shown in Fig. 204, will be doubled in boring a piece of work. Therefore the best test of ascertaining the boring quality of the lathe will be by bolting a cast iron test piece to the face-plate, as shown in Fig. 205. A very light cut is taken off from the raised portions C, C, and measure- for test pieces for different sized lathes are given in Fig. 207. To test for the concavity or the convexity of the face-plate it is usual to use an ordinary straight-edge and three slips of paper. This may be nearly correct, but we have no means of knowing the exact amount of the error. For this reason the micrometer straightedge shown in Fig. 206 was designed. The stock A is slotted at each end, and in these slots are secured the outer points B, B, ca- pable of being adjusted to different diameters of face-plates, and are secured by the thumb-nuts C, C. The center point D is a micrometer head, operated by the usual milled head E. Slips of paper are now introduced between the points and the face-plate. The micrometer position is noted, and then adjusted to hold the center slip of paper, when a second reading will give convexity or concavity of the face-plate. Inspector, A critical examination of the above list of questions is invited in order to fully appreciate the value of such a thorough system of tests both to the concern who builds the lathe and to he who purchases and uses it. Such a system will give a healthy tone to the workmanship of the shop, and when fairly met by the conditions of the machines turned out will be a source of pride to the workmen employed in it. On the other hand it will give a feeling of confidence and security to the purchaser, who will naturally feel that he is getting full value for the money he has spent in purchasing the machine. Further, the lathe going into the shop with such prestige will naturally be looked upon as a good machine, and more than the usual amount of care will be bestowed upon it and upon the product which it turns out. The use of hand tools. Simple lathe work. Lathe centers. Care in reaming center holes. Locating the center. Use of the center square. Angle of centers. Lubrication of centers. Centering large pieces of work. Driving the work. Lathe dogs. The clamp dog. The die dog. The two-tailed dog. Lathe drivers. Using dogs on finished work. Clamp dog for taper work. Bolt dog. Methods of holding work that cannot be centered. Center rest work. Chuck work. Use of face-plate jaws. Lathe chucks. The Horton chuck. The Sweetland chuck. The Universal chuck. Face-plate jaws. A Horton four-jaw chuck. The Horton two-jaw chuck. A Cushman two-jaw chuck. Chucking cylindrical work. Inside chucking. Chucking. Chucking work supported in a center rest. Pipe centers. Mortimer Parker's improved forms of pipe centers. Spider centers. Ball-thrust pipe centers. Lathe arbors or mandrels. Kinds of mandrels. Expanding arbors or mandrels. Making solid arbors. The taper of an arbor. Hardened and ground arbors. The Greenard arbor press. Its advantages. IN the chapter on lathe tools the subject of hand tools was purposely omitted, as their use has greatly diminished during the past few years, with the possible exception of their employment on small bench lathe work and on some kinds of brass work, and much of the work formerly done with hand tools is now done in the regular operations on the turret lathe, the screw machine, and with forming tools on ordinary engine lathes. When the apprentice is first put to work on a lathe it will probably be the turning of a piece of shafting on centers, and his first duty will be to center it, that is, to drill and ream proper bearings for the center. If he is in a modern shop the old method of form- ing the center hole by means of a prick-punch and a hammer will not be tolerated. Neither will the practice which succeeded it, that of drilling a small hole and then spreading it out or countersinking it with the center punch. The hole was once drilled with a " fiddle-bow 'drill/' which was later replaced by the geared breast drill, which is very convenient for some jobs but not a tool to drill a good center hole with. Lathe centers should be accurately ground to an angle, at the point, of 60 degrees. Center grinding attachments are provided for this work (as shown in the chapter on lathe attachments), which will give a very perfect angle. Of course the center has been previously hardened so as to stand the wear of the revolving piece of work. Nevertheless there should be considerable care exercised in drilling and reaming the center hole so that it shall really fit the angle of the center. There are various ways of doing this. The most convenient way is to use for this purpose a combined drill and countersink shown at A in Fig. 208, which will drill the center hole and countersink or ream it to the proper angle. These are made of various sizes to adapt them to the diameter and weight of the work to be centered. At B is shown another and older form of center reamer which is made by turning up the tool to the proper angle and then cutting away the upper half so as to give a cutting edge. sinking. To center a piece of round material it may be first " scribed" by the dividers or the hermaphrodite calipers (a caliper having one regular caliper leg and one pointed one, similar to the leg of dividers), which are set approximately to the radius of the piece, and three or four arcs marked across the previously chalked surface, forming a small triangle or a square, within which the first prick-punch mark is made. This is followed by the drilling. This may be more quickly done by a center square shown at C, Fig. 208, applying it as shown and scratching a line across the work, then turning the work about a quarter turn and scratching again in the same way. The intersection of these lines will be the center, which may then, be marked with the prick-punch as before. The use of a centering machine will much facilitate the work on small and medium sized work. In this machine the work is held in a self-centering chuck, mounted on a short lathe bed and holding the piece of work exactly in line with and in front of the center drill and countersink shown at A, and held in a chuck carried by the spindle of the machine which has a head-stock quite like that of an ordinary lathe, and the spindle adapted to slide forward in drilling the hole. By the use of this machine the center drilling and countersinking will be in accurate alignment with the axis of the work, and with this drill the angles will be correct, the work and the center appearing as shown at D, in the above engraving. Should the form of a center reamer, or countersink, be too obtuse an angle the effect will be as seen at E, in which it is seen that the center bears only slightly near its point. It will thus be worn out of shape and quite naturally the axis of revolution will change. If the angle of the center hole is too acute the lathe center will only bear at the edge of the hole, as shown at F, and the tendency will be to wear a crease around the center at this point, and the work will finally "run out," that is, the axis of revolution will change as in the last example. Should the drill and countersink not be in line with the axis of the work the result will be as shown at G, and the work will not only run out of true in a little time, but the lathe center is likely to be spoiled. The proper lubrication of tail centers is important, otherwise the pressure will create so much friction that the center will heat and "burn off." To prevent this some centers, particularly large ones, have an oil hole drilled in the point, which is left large enough for that purpose. This hole connects with one at right angles with it and opening beyond or outside of the end of the work, and through which oil may be introduced while the lathe is running, thus keeping the center always well lubricated. The plan is an excellent one on heavy work, or in fact on nearly all work in lathes of 24-inch swing and larger, and the larger the center the more benefit will be found in its application. From these examples and remarks it will be seen that much depends on making the center holes of the right form if we expect to produce a good piece of turned work. In centering large pieces of work it is sometimes the custom to hold one end of the shaft or forging in a chuck on the main spindle of the lathe, and the other end in a steady rest, or center rest. The lathe is started and a pointed tool set in the tool-post is brought against the work and the center scratched into it as it revolves. This is quicker and more accurate than the scribing method, particularly in the case of heavy and rough forgings. The piece of work having been properly centered, we apply to it a dog which serves to drive it and suspend it between the centers, first carefully oiling the tail-stock center and setting it up just tight enough to hold the work closely and without end motion. by the set-screw and the work is driven by the tail of the dog entering the driving slot in the small face-plate of the lathe. The clamp dog shown at 2 is useful for driving square or flat pieces, and is also frequently used for cylindrical work, which it is not so liable to mar as is the set-screw of the first form. At 3 is shown another form known as a die dog, the jaws being movable and closed up by the set-screw. The jaws being threaded may be applied to threaded work which is of such form that a dog cannot be placed upon any part but that which is threaded. At 4 is shown what is called a two-tailed dog, sometimes used on large work and driven from " drivers" placed against the two tails. These drivers may be made for the purpose and consist of a piece of round steel of sufficient length to reach from the front of the faceplate out to and across the dog, and be secured to the face-plate by a cap screw, with a washer under its head, and coming through the face-plate from the back and into the end of the driver. Or it may have a shoulder and be held by a nut. More often, however, the driver is a bolt long enough for the purpose, with a sleeve made of a piece of gas pipe or a block of cast iron with a hole through it, which keeps the end of the bolt far enough to reach the dog. In placing dogs on finished work a piece of brass or copper should be put under the points of the set-screws to prevent marring the work. In using the clamp dog at 2 on finished work the pieces of brass or copper should also be used. Various other forms of dogs are used for special work and for very large work ; as, for instance, two more or less curved bars and fastened together by bolts, somewhat in the form shown at 2, Fig. 209. But in all cases the principle is the same, to clamp to the piece of work a device having formed upon it a projecting part, called the tail, by which the work may be rotated. In some cases when the clamp dog shown at 2 is much used on taper work the heads of the clamp screws are made in the form of eyes, and the upper cross bar or clamp bar has trunnions or bearings turned on each end which enter into the holes or eyes of the bolts. By this means the clamp bar may turn in its bearings sufficiently to have its flat side set fairly on the inclined surface of the taper. In driving bolts which are to be threaded and in which the marks of the center hole in the top of the head are not objectionable, a "bolt dog" is used. This is simply an offset plate fastened to the face-plate by a single bolt and its free end slotted so as to embrace the head of the bolt. This device is not much used at the present time as bolts and cap screws are usually made from a bar in the turret lathe at much less cost than is possible to produce them in an engine lathe. Lathe work that is not held suspended between centers must be held by one of the following methods, namely : bolted or clamped to the face-plate ; held entirely in a chuck ; one end held in a chuck and the other in a center rest; or secured to the carriage, or some part of it, as in boring jobs. One exception is made to these statements. This is that work may be held against the head spindle center by any convenient means, and the other end supported in a center rest. This is usually only resorted to for such work as boring and reaming and, with the exception of the advantage derived from accurate centering by means of the head spindle center, is not a very advisable method of running work in a lathe, particularly when a chuck with truly concentric jaws is at hand. What is ordinarily called center rest work is all kinds in which one end is supported in a center rest. Of course this does not include work held on centers and supported in the center or at any intermediate point by a center rest. In this case many machinists call it a " steady rest," rather than a center rest, and this function may be readily performed by a back rest or what is called by some manufacturers a steady rest, which has the three jaws of the center rest, although they are not placed equidistant around the circle and the supporting casting is left open in front instead of being provided with a hinged top segment. Chuck work and face-plate work is very closely allied, and in fact very many face-plate jobs can readily be done in a chuck, and nearly all chuck jobs can be done if fixed to the face-plate in the usual manner. It is altogether probable that the first chuck made was simply a face-plate provided with jaws temporarily attached, and it is more than likely that these "jaws" consisted merely of blocks or studs fastened to the face-plate and provided with setscrews for holding the work. chucks is shown in Fig. 210. At A is shown a face view of the finished chuck. It consists of a front and a back plate shown respectively at D and B. The jaws are moved in and out simultaneously, by means of the geared steel screws, the small bevel pinion formed on them engaging the circular steel rack C, which is enclosed in a deep groove or recess in the back plate B, as shown. At D is shown the front plate with the jaws in place, with the projecting portion at the back tapped to receive the steel screws, which are shown in place. The front and back plates fit each other closely, making a perfectly tight casing for the gearing and screws, so that no dirt, chips, etc., can possibly get into them and clog and injure the gearing. The jaws are forged solid, by which great strength is secured to withstand the strain of heavy work. At A, Fig. 211, is shown a Sweetland chuck, which in a general way is similar to the Horton chuck, but possesses some advantages, in that it may be used as a " universal" chuck, so called, in which all the jaws move simultaneously to or from the center, or it may be readily changed so that the jaws work independently of each other, thus adapting it to a large variety of irregular and eccentric work. The design of the improvement is to make the chuck independent as well as universal, thus combining two chucks in one. In the recess underneath the rack are the cam blocks, beveled to correspond with the level recess in the rack. The cam blocks are held in place by the convex spring washers, which allow them to be moved to or from the center without disturbing the nuts, the friction being sufficient to hold them in place. When moved to the outer portion of the rack they connect the gearing, making the chuck universal, and when moved inward they disconnect the gearing, thus making each screw independent. The advantage of making each screw independent, without disconnecting the others from the gearing, is a feature not combined in any other chuck, and is an improvment fully appreciated by the mechanic when adjusting the jaws for eccentric, concentric, or universal work. For instance, the chuck having been used independent, the workman wishes to change to universal, the jaws are moved inward until the outer end is true with the line on face of chuck; now each screw can be engaged with the rack separately by sliding the cam block outward. If one jaw is found to be out of true it can be disconnected and reset, leaving the others in mesh undisturbed. At Fig. 211 are shown the face-plate jaws heretofore referred to, and which, when attached to a face-plate, make a very serviceable and practical substitute for a chuck, and advisable to have from questions of economy, even on lathes as small as 30-inch swing, while on lathes above 40-inch swing they are all the more useful, and on 50-inch swing and larger are almost indispensable, as the largest chucks usually made are 42-inch and these are very heavy and very expensive, while a set of four jaws for the face-plate may be had at a comparatively nominal cost. may demand. At C is shown a Cushman two-jaw chuck, with provision for slip, or "false jaws." By this construction special jaws may be made with faces of such contour as to fit the irregular form of the pieces to be machined. This form of chuck is used for the machining of valve bodies and similar work, and is sometimes fitted with various indexing devices by means of which the piece may be turned from side to side and held while various operations are performed. Special chucks are made of various forms and with a varying number of jaws, of a variety of different shapes, all of which are too numerous to illustrate or describe here. jaws the work is correctly centered by the chuck jaws, provided there are no uneven places on the work, which by coming under either of the jaws tend to throw it out of true. Such work is usually that of boring, reaming, or facing, and similar work on the face or inside of the casting or forging, and such part of the outside as extends beyond the chuck jaws. It should not be forgotten that while we usually grip work upon the outside, the chuck jaws work equally well by bearing against the inside of the work; for instance, the inside of the rim of a gear that is to be faced, bored, and reamed. When round rods or bars are to be machined or pieces cut from them, whether to be partly machined or not, a drill chuck, so called, is used. This is a two-jaw chuck, the jaws being of a variety of forms, from the shape shown in Fig. 212 to V-shaped jaws with interlocking teeth, the design of all of them being to hold the bar or drill firmly, with as little force applied to the right and left screw that operates them as possible. Work may be such that one end is held in the chuck and the other supported by the tail-stock center, or by a center rest whose jaws furnish a three-point bearing for the cylindrical surface of the work. While the method of supporting the work by the tail-stock center is used for work that is to be turned, the second method, that of supporting the work in a center rest, is better adapted for drilling and reaming operations. These operations may be wholly done with the drill and reamer, or by the use of an inside boring tool held in the tool-post of the compound rest. It is a common job to have to face up the flanges on the ends of pipe of various sizes. Sometimes these pipes are of wrought iron or steel with the flanges screwed on. Sometimes they are cast upon cast iron pipe. The ordinary method is to hold one end in a chuck and the other end on a "pipe center," of one form or another. One form of these centers is called a " spider center," and often consists of any convenient casting, circular in form, that comes handy. With several set-screws tapped radially into its edges and adapted to be backed out against the inside of the pipe and firmly held, while a drilled and countersunk hole in the center affords a good bearing for the lathe center. Mr. Mortimer Parker suggests some improved forms which are shown in Fig. 213, in which A shows a new spider center which is quite different from the old style B that requires, as shown, a block of wood against it to keep it from shoving in or twisting sideways when the center is pressed against it, or when a heavy cut is started. This improved center will stand a heavier cut and can be set quicker than the other style. If the outside is turned true with the hole the job can be set very readily. C, D, and E show end views of different forms of this center; and F, G, and H are different sizes with bronze bushings in the interior. can be turned into a spider center by, drilling three rows of holes and putting in set-screws and jam-nuts, only one set of screws being needed, as they can be used in either series of holes. A spider center allows room for the tool to clear when facing off the end of a flange, but a cone center does not. When the tool gets down to the center, as at J, it leaves a shoulder which must be turned off with a pointed tool. K is a center with a cone bearing at each end of the hole, which keeps free from play even if it does wear. Center L is less work to make, but does not turn around when a heavy cut is taken ; hence a ball-thrust bearing should be used as at M for heavy work. with heavy work. In facing up pipe flanges it is sometimes the practice to hold one end in the chuck and support the other end in a center rest. The disadvantage of this method is that the roughness of the outside of the pipe is a very poor bearing for the center rest jaws and poor work in facing is likely to result, while the same pipe carried on a pipe center, in the same lathe, will be a creditable Lathe arbors are an important adjunct to lathe work. They are commonly called arbors although the old English name of mandrel is the proper word, as an arbor is properly a carrier for a tool, as a saw arbor, a milling machine arbor, etc., while a mandrel is used for carrying a piece of work to be turned. Mandrels are of two kinds, solid and expanding. The solid mandrel should be made of hard machine steel or a cheap grade of cast steel capable of being hardened. common form. The ends are turned down somewhat smaller than the central body, and on one side, at each end, is a flat space for the set-screw of the lathe dog to rest upon. The ends are slightly recessed around the center hole so that it will not be bruised if the end is struck with a hammer. The central body should be ground with a very slight taper. The entire piece should be hardened, not simply the ends, as formerly. A J-inch arbor should be 3 J inches long and a 4-inch arbor 18 inches, all intermediate sizes being of the same proportion. At B, Fig. 214, is shown an expanding arbor or mandrel. This is made in two parts, the arbor proper and an outer shell. The inner arbor is turned and ground to a considerable taper and the outer shells accurately fitted to it. It is then split, as shown, by from eight to twelve cuts, alternately beginning at opposite ends, so that in forcing the inner arbor in on the taper the outer shell is expanded in very nearly a circular form, at least near enough for all practical purposes. A cheap imitation of this really excellent device is made by splitting the outer shell all the way through at one point only, which will do as a makeshift when nothing better can be had. There are various forms of expanding arbors, some of which have considerable merit and others very little. The one illustrated above will probably be found to give the best satisfaction. In making solid arbors it should be remembered that they must be turned considerably over size, then hardened, which will change their form somewhat, and then rough ground to nearly the proper size. They should then be laid aside for some time to give the steel an opportunity to take on its final changes and attain a permanent condition as to size, straightness, etc., before it receives its final finish grinding, which should diminish its diameter very slightly. The drilling in the ends for the center hole and the countersinking should be carefully done, the angles of the sides of the countersunk hole being exactly 60 degrees. Arbors are hardened for several reasons, principally to make them accurately cylindrical, much stiff er and more rigid, and also less liable to accidental injury, but not to prevent lathe tools from cutting into them when used by a careless workman. The taper on an arbor is usually about a hundredth of an inch per foot with the center of the arbor of the standard diameter. The fact that the arbor is tapered to this extent makes it necessary to be careful to force the arbor into the reamed hole from the same side that the reamer has entered, which should also be the same side first entered by the piece that is to fit in the hole, provided it is to be a close fit. This is frequently marked on the drawing and it should always be so indicated for the guidance of the workman. Hardened and ground mandrels serve the very excellent purpose of preserving the uniformity of sizes of holes, since if the holes are not truly sized the pieces will either drop on to the arbor too loosely or fail to go on sufficiently for good and convenient work. Again, the arbor being so slightly tapering, the workman will in the work in this respect. The use of expanding arbors has not these advantages as they are ground perfectly straight. But they are to be preferred for this very reason when running fits are desired. Arbors should not be driven into reamed holes with a hammer. An arbor press should be used and the author knows of none better than the Greenard press, which is made in various sizes, from the small one to fasten to the tail end of the lathe bed to the largest sizes which have a broad floor base. One of the former is shown in Fig. 215. By the use of these presses there is no shock in forcing an arbor into the work, and therefore neither the arbor nor the work is injured. In addition to this advantage, the arbor maintains a perfect alignment with the hole as it is forced in, and therefore there is no unequal strain or distortion. The rack and pinion arrangement of this arbor press is at once simple and effective, and the rotating table with its various sized recesses in the edge furnishes an excellent bed for supporting the work as the arbor is forced into it. A more convenient arrangement could scarcely be imagined for this work. Irregular lathe work. Clamping work to the face-plate. Danger of distorting the work. A notable instance of improper holding of face-plate work. The turning of tapers. Setting over the tail-stock center. Calculating the amount of taper. Taper attachments. Graduations on taper attachments. Disadvantages of taper attachments. Fitting tapers to taper holes. Taper-turning lathes. Turning crank-shafts. Counterbalancing the work. Angle plate for holding the crank-shaft. Forming work. Forming lathes. Drilling work on the lathe. Chuck and face-plate drilling. Holding work on the carriage. Boring a cylinder. The author's design for boring large cylinders. Holding work by an angleplate on the face-plate. Thread cutting. Calculations for change-gears. Reverse gears. Arrangement of the change-gears. Ratio of changegears equal to ratio of lead screw to the thread to be cut. Cutting lefthand threads. Compound gearing. Calculating compound gears. Cutting double threads. Triple and quadruple threads. Boring bars. Varieties of boring bars. Driving boring bars. Boring large and deep holes. The author's device. The drill, boring bar and cutters for the work. Flat cutters for boring holes. Boring bar heads or arms. Hollow boring bars. Milling work on a lathe. Milling and gear cutting on a speed lathe. Grinding in a lathe. Cam cutting on a lathe. Many uses for the engine lathe. THERE is so much irregular work constantly done on the lathe that no specific description of it can be given. It is the unknown quantity that the machinist has to deal with and he is expected to be equal to the occasion and so fertile of resources as to be ready with a proper method for doing every job that turns up, that he will not be obliged to hesitate long for means to accomplish the end sought. Much of what may properly be called irregular work will be such as can be handled on the face-plate or in an independent jaw chuck. Yet these appliances for holding the work will frequently and the follow rest, as well as the taper attachment. In clamping work on the face-plate there is danger of springing the work as it is fastened down. The result will be that it is held in a distorted position while being machined, and upon being released by the bolts of other clamping devices it will spring back to its original position and so show distorted machining. For this reason much care should be exercised to see that it rests fairly on the face-plate immediately under the clamps or bolts that hold it down. The same idea applies to rings or similar shapes when held in the jaws of a chuck or in face-plate jaws. There is always the possibility of springing them out of shape and that this forcing process will show in distorted work when the piece is taken out of the lathe. The author once saw rings of cast iron two inches thick, 6 inches wide, and about 30 inches inside diameter, pressed out of shape by the face-plate jaws attached to a 60-inch face-plate, so much that several of them were spoiled, and the expedient of strapping them to the face-plate had to be resorted to in order to produce work as true as the job called for. Work may also be distorted when carried in a steady rest, a back rest or a center rest, by this attachment having been set out of line, either too high, too low, or to one side. Much more care is needed in adjusting these attachments than they sometimes receive. The turning of tapers may be classed as irregular turning work. • If they are slight the tail-stock center may be set over sufficiently to give the required inclination, particularly if the work is long. When the taper is considerable, it will not be proper to set the tailstock center over for this purpose as it throws the head-stock and tail-stock centers too much out of alignment to work properly. This is shown in Fig. 215. One half the taper shown, on this length and B the tail center. It will be noticed, however, that if the work is but half as long and the tail-stock center located at C, the inclination will be twice as great and consequently the error in the alignment of the centers double what it would be with the tail-stock center located at B, and the case more impractical than at first. The tail-stock is arranged so that the center may be set over to the rear as well as the front, so that the small end of the taper may be toward the head-stock when such a position is more convenient. In setting over the tail-stock center it must be borne in mind that the difference in diameter between the large and the small end will be twice the distance which the center is moved from the center line of the lathe. Therefore, if the work is two feet long, and we want a taper of one inch in two feet, or half inch per foot, we set the tail spindle over half an inch. The amount set over at the tail-stock gives double that taper in the whole length of the work. Consequently, if we divide the amount of taper on the entire length of the work by the number of feet in length, we get the taper per foot. If this simple rule is remembered the mistakes that often occur in turning tapers will be avoided. In all taper turning, however, it will not be sufficiently accurate to measure the amount of tail-stock set over, but the work must be carefully calipered as the turning process goes on. When the taper is considerable, it is better to do the work in a lathe having a taper-turning attachment. Examples of this device will be found in the chapter on lathe attachments, where it will be seen that the travel of the compound rest in a transverse direction is governed by a swiveling bar which may be set at any desired inclination with the V's of the lathe. While there are usually graduations on the end of the taper attachment that are intended as a guide in setting the swivel-bar or guide, they are frequently misunderstood and consequently useless. Usually they are marked for so much taper per foot, and when so designated the length of the work in feet must be considered, if the diameters at the large and small ends are given on the drawing. of no benefit whatever to him, as his drawing will very seldom be dimensioned in this manner, but rather the extreme diameters given, or the taper will be so much per foot. The use of the taper attachment permits a much wider range of tapers to be turned than can be successfully accomplished by means of the set-over feature of the tail-stock. And we have the great additional advantage of always keeping the centers in line, so that accurate work can be done, which is not always the case when the tail-stock is set over, except for very slight tapers. One of the drawbacks to the use of taper attachments is that a certain amount of back-lash is liable to exist when many parts are necessary to the design of the mechanism, from the guide-bar or swivel-bar to the point of the cutting-tool. These will give a certain amount of difficulty in making a straight, smooth cut. Consequently, the gibs should be set' up as close as practicable, all nuts and adjusting screws set up tight and as much vibration and back-lash eliminated as possible, and then the back-lash be taken up by hand before the tool begins to cut. In all taper turning it is necessary that the point of the tool be set at exactly the height of the points of the centers, otherwise a true taper will not be the result but will be slightly concave rather than in a straight line. In all cases, in turning tapers to fit a tapering hole, the exact amount of taper should first be obtained so as to fit the tapering hole, but to be considerably larger than its final size. Then the diameter is turned correct, the calipering being usually done at the small end. Taper-turning lathes are sometimes made in which the headstock and tail-stock are mounted upon a separate bed which is pivoted at the center so that it practically amounts to the lathe swiveling while the tool carriage runs straight. In this lathe the centers are, of course, always in line, the setting for the required result is quickly done, and as the whole mechanism may be of very rigid construction, the work done on it is very accurate as well as economical. The turning of crank-shafts is a frequent trouble to the inexperienced man who has this work to do. In the present case it is assumed that the crank-shaft has been properly "laid off" with a surface gage, on the surface-plate or table, and the centers nearly its finished dimensions. The operation to be performed is to turn the wrist-pin. This is shown in Fig. 216. At A is shown the usual method of rigging up for the job. The shaft is placed in V-blocks on the surface table and the wrist-pin blocked up to the proper height, as shown by the surface gage, so that there will be stock enough left on all sides to finish up to the given dimensions. The "offsets" or " throws," C, C, are now put on and the centers accurately located by the FIG. 216. I The centers are now measured all around with the surface gage once more, to make sure that all are in the same plane. The crankshaft is now placed in the lathe, the centers in the offsets being used as they are directly in line with the wrist-pin center. A tool long enough to reach down between the arms of the crank must be used. It should be made with a very narrow point, be kept very sharp, and set either on the center or but a trifle above it. The idea is to avoid as much as possible any undue strain in the turning, as the work will not be very rigid and the cuts taken must be light. The wrist-pin being turned and finished, the offset pieces C, C, are removed, a block fitted in the space D, between the arms of the crank, and it is placed on the shaft centers and finished as any other shaft would be. One of the precautions that should be taken is to have the work properly counterbalanced by adding on the face-plate the proper weight, opposite the crank when turning the shaft, and opposite the shaft when turning the wrist-pin, so as to prevent undue strain and vibration. Another and more rigid arrangement is shown at B, in Fig. 216, in which, in place of an offset piece at the face-plate end, the bracket or angle-plate E is used. This is bolted to the face-plate and has a cap F fitted to it and bolted firmly, with the joint held slightly apart with paper or thin cardboard. It is then bored out the exact diameter of the end of the crank-shaft, which is firmly gripped in it and the shaft much more rigidly held than in the former example. The offset piece C is used at the tail-stock center the same as before. In all these operations great care should be used to lay out all the centers in the same plane, and to locate the offset arms in the same manner. The free and careful use of the surface gage will be necessary to success. Forming work has been described in another part of this book, and the reader interested in this class of work is referred to the chapters in which these matters are considered. The particular points to be observed in forming work are: to hold the work very rigid; to have a very rigid cutting or tool carriage; to have a tool with a very sharp and carefully "stoned-up" cutting edge; to use a comparatively slow speed and a very fine feed. reached. This makes the lathe semi-automatic, in that it need only be set and started, and no further attention given to it until the cut is completed. Thus one man may run a number of machines, and the relative efficiency of each will be reckoned, not so much in the large number of pieces turned out, as in the small cost for labor, which is usually the most expensive item on this and similar classes of work. This is seen very readily in the automatic screw machine, which turns out much of its work much more slowly than the turret lathe. But the turret lathe requires the constant attendance of a skilled operator, while one man may take care of from four to ten automatic screw machines. In many respects the engine lathe may be made to take the place of the upright drill, although this class of work is now usually done in the upright drill, the radial drill, or the boring machine. However, there are shops which do not possess all these facilities and still have many jobs that may be properly done in the lathe. To the ordinary jobs of chucking and reaming it will not be necessary to refer. The same may be said of ordinary drilling such as may be done by holding the work in the chuck and using either a flat drill with a center hole in its rear end for the tail-stock center, and the drill held from turning by a wrench, or similar contrivance. Drills may be held in the tail-stock spindle, in place of the tail center, if the taper hole is standard as it should be, or when the drill shank is too small a collet may be used. In this way many jobs of chuck or face-plate drilling may be done. When the work is such that it is necessary to revolve the drill instead of the work, the drill may be transferred to the head spindle and the work held by bolting or strapping it to the carriage, the compound rest having been removed for that purpose. or other fixture suitable for holding the work to be drilled. There is a wide range of possibilities in this class of work and the ingenious machinist is generally very resourceful in this direction. The following is a case in point; and if the casting has no hole through, or one so small as to require a boring bar too small in diameter to get a steady rest cut, it is almost impossible of accomplishment on the boring machine. The casting shown, marked C in Fig. 217, is of such a nature. The primary factor in the boring of these cylinders is the making of the bracket A, which forms a solid support for the boring bar B. The boring bar B is driven in the usual way, or rather in one of the usual ways. It will be noticed that the taper shank is held from turning by being screwed into the spindle of the lathe head-stock, and that it has a conical bearing at the outer end in the bracket A. The bearing is thus adjustable to take up "back-lash" by sliding the bracket A to the right along the lathe bed, which in this case is of the ordinary English pattern, with a flat bed. Of course, by making the bottom of the bracket to suit the raised V's, the attachment is capable of being made to suit the American style of bed. The cylinder C is bolted upon a slotted plate attached to the carriage D, upon parallels. In planing the base of the castings, care was taken to make them in all cases of equal distance from the face of the base to the center of the casting — not to the core, as this was liable to be slightly out of true. Three cutter heads, two roughing and one finishing, were made like the one shown at F, at the right, in Fig. 217. All had four cutters slanting to the left at the inner end, in order to bring the cutting edges outside, or near the end of the block. E is turned to the angle at which the cutters were required to be fitted at the point G, and a clamping ring F, turned to fit, was afterwards clamped on by means of four filister head screws. Four holes, as at J, in the small view at the right, were drilled in line with the joint to fit the cutters. After drilling, a small amount was turned off the inner face of the clamping ring F in order that the tools would be clamped when the screws were tightened. This ring when tightened up was found to be sufficient to prevent the cutters slipping in. To insure the cutters all having an equal cut, the cutting edges were ground and also backed off by means of a cutter bar, mounted on the slide-rest and driven from overhead. The finishing cutter finished from six to a dozen holes at one grinding and it was then a simple matter to set them out a little and regrind. It was found to be advisable to take out and grind the roughing cutters separately on an emery wheel, as working in the sand they wore rapidly. Sometimes one broke in cutting out a projecting lump of metal and they wore generally unevenly. The hole H, Fig. 217, was bored out (from a cored hole) by two cutters, as shown (roughing and finishing), fluted similarly to rose bits or reamers. The roughing cutter was passed through at the same time as one of the roughing cuts in the large hole; the finishing cut, however, was taken separately to avoid disturbing the large finishing cut. The carriage was fed up mechanically by means of the rod feed. useful on other jobs as well. The author once designed and built a lathe for doing a similar job to the one here described and illustrated, but on a much larger scale. In this case it was required to very rapidly bore and finish large cast iron cylinders about four feet in diameter. As there was ample power to do the work, and sufficient length of bed was allowable to bore a number of these cylinders at a time, and as they were quite short in proportion to their diameter, the lathe was arranged to bore two cylinders at once, with three tools for each cylinder, namely, a roughing tool, a sizing tool, and a finishing tool. Each of these consisted of a cross bar attached to a boring bar, and carrying a cutting tool on each end. By this arrangement there were twelve cutting tools in action most of the time, and as two cylinders were bored during the time of the travel of the tool across one, the result was that of doubling the capacity of the former machine which did this work. Another method by which boring work may be done is to attach it to the face-plate of a lathe by the use of an angle-plate, by which means various shaped pieces having a finished surface at right angles to the axis of boring may be conveniently held. Elbows are well handled by this device and many similar jobs will readily suggest themselves to the machinist. And not only boring, but many jobs of turning on such shaped pieces may be conveniently handled by the use of the angle-plate attached to the face-plate of a lathe. Thread cutting in a modern lathe provided with a quick change gear device for cutting any number of threads per inch, by shifting one or more levers, is a comparatively simple matter. With a lathe equipped with removable change-gears for accomplishing the same purpose it is much more complicated, and its principles frequently misunderstood. Therefore a clear understanding of these principles is necessary to any one who aspires to become an intelligent machinist. The spindle or head shaft of the lathe runs at the same speed as the main spindle; therefore it takes its place in all calculations for thread cutting. Upon this spindle the first change-gear is placed. The lead screw carries the second change-gear. , The ratio of these two gears determines the ratio of the number of revolutions of the main spindle to those of the lead screw. The changegear placed between this first and second change-gear is an idler gear, since it runs loosely on a stud and serves only to communicate motion, but does not in any way change or modify the ratio. the ratio. The arrangement is shown in Fig. 218, in which a is the head shaft or spindle; o is the lead screw, and c the adjustable stud in the adjustable stud-plate, segment, quadrant, or sweep, as it is variously termed, marked d. A is the first change-gear ; B the second change-gear, and C the idler gear. As shown, the two gears A and B are of equal diameter and number of teeth, consequently the lead screw revolves at the same rate of speed as does the main spindle. It follows, therefore, that if the lead screw is cut with four threads per inch the lathe carriage will move a quarter of an lathe will cut four threads per inch. If the change-gear A is only one half the diameter of the change-gear B, the lead screw will revolve only one half as fast as the main spindle, and the lathe will cut eight threads per inch; while if the change-gear B is one half the diameter of the change-gear A, the lead screw will cut two threads per inch. accordingly, and produce a thread of like ratio to the number of threads per inch with which the lead screw is cut. Otherwise, the ratio of the change-gears A and B equals the ratio of the thread of the lead screw to the thread to be cut. To cut any desired number of threads per inch it is first necessary to find the ratio which the desired number of threads bears to the number of threads on the lead screw; then to select such change-gears as bear this ratio to each other, remembering that if the desired thread is of a coarser pitch than that of the lead screw, the change-gear A must be the larger, and if it be a finer thread than that of the lead screw, the change-gear B must be the larger. The gears will revolve in direction of the arrows, by which it is seen that the lead screw revolves in the same direction as the changegear A on the head shaft a, and consequently as the main spindle of the lathe. This arrangement, with a right-hand thread (as usual), on the lead screw 6, will cut right-hand threads. When the proper ratio cannot be obtained by the use of the change-gears at hand, or when the gears of the desired numbers of teeth would be too small to properly connect, or too large to be put in place, recourse must be had to what is termed compound gearing. Referring to Fig. 221, and the series of change-gears A, suppose that it is desired to use compound gears, making the ratio 4 to 1. A 36- tooth gear is placed on the head-shaft and a 72tooth gear on the lead screw. On the idler stud we place two gears, a 48 and 24, fixed to each other by placing them on a splined compounding sleeve which runs loosely on the stud. The 36-gear is engaged with the 48, and the 24 with the 72,. as shown in elevation at A, Fig. 220, and more clearly seen at A, in the diagram, Fig. 221. the ratio would be 2. These ratios multiplied would be 4. As they are engaged we have 36 to 48, which is a ratio of 1 J, and 24 to 72 is a ratio of 3, which multiplied by 1 J produces 4. single idle gear is to double the ratio existing between the gear on the head-shaft and the one on the lead screw. The combination as shown would cut 16 threads per inch on a lathe having a lead screw cut with four threads per inch. (Usually lathes will cut this number of threads without compounding. The gears here shown and described are given as a simple example.) 72-gear is placed on the head shaft and the 36-gear on .the lead screw. The effect now is, instead of multiplying the pitch of the lead screw by 4 (4 X 4 = 16 threads per inch on the work cut), the number of threads of the lead screw is divided by 4 (4-r- 4 = 1), thus producing in the work a screw of one thread per inch, or oneinch pitch. By a thorough and correct understanding of these principles there should be no difficulty in setting up a lathe for any desired number of threads per inch. It is usual to have compounding gears of a ratio of 2 to 1, as 24 and 48, 36 and 72, and so on. But it may be necessary to use other ratios as H to 1, say 48 and 72, 24 and 36, etc. Or to make the ratio 3 to 1, as 24 and 72, 36 and 108. It is always advisable to use as large change-gears as possible, as the motion of the lead screw is more regular and steady, and the strain on the gear teeth is less, consequently better work can be done. This should be practised even if compound gears have to be used more frequently. In cutting double threads the change-gears are set for double the pitch, that is, one half the number of threads which the finished thread is to be. Then proceed to cut one of the threads, leaving the proper blank space between the convolutions for putting in the second thread. To locate this properly a tooth in the stud gear may be marked, and also mark the space in the intermediate gear into which this marked tooth has meshed. Now lower the intermediate gear out of the mesh, by unscrewing the clamp bolt of the stud-plate for the purpose, and turn the spindle exactly one half a revolution, that is, until one half the whole number of teeth have passed the marked space in the intermediate gear, and the marked tooth is exactly opposite its former position. Raise the stud-plate, putting the two gears properly in mesh with each other, and go on with the cutting of the second thread. This is assuming, of course, that the stud gear has an even number of teeth and that the ratio between the lathe spindle and the head shaft or gear spindle is 1 to 1, both conditions being the usual ones. Another method of accomplishing the same result is to have two dog-slots in the small face-plate exactly opposite each other, and after one of the double threads is finished, to shift the tail of the dog into the other slot. Triple and quadruple threads are cut in a similar manner, but all the details of the work are much more complicated and difficult, both in making the proper calculations to insure the exact thickness or pitch of the threads, and in grinding and setting the tool so as to get the correct cutting angles and clearance. Boring bars may be used in various ways. They may be supported on both centers and the work they are to bore strapped to the carriage. They may have one end fitted to the taper hole in the head spindle and the other end carried by the tail-stock center and the work held as before. Or, the boring bar may similarly be held in the tail-stock spindle and the opposite end supported in a bushing, in the center hole of the main spindle, while the work may be carried in one of two ways. That is, it may be strapped to the face-plate, or held in a chuck; or; if comparatively long, cylindrical as follows: Given the task of boring a 5J-inch hole endwise through a hard steel spindle 7J inches in diameter and 5 feet long, with a large and powerful boring lathe, such as is used on gun work, and the work would be comparatively easy and rapid. Having only the equipment of an ordinary machine shop, the case becomes more serious. In the regular course of business such a job was required to be done, A soft brass tube of about iVinch bore, carried oil under pressure to the point of the drill and on its return brought out the chips. The spindle was then reversed and the hole was bored from the opposite end until the two holes met, which they did quite exactly. Now came the work of enlarging the hole from 2 inches to 5J inches. It is to this part of the work that particular attention is called. As the means for holding the drill had proven very rigid and satisfactory, a boring bar was constructed, as shown in the upper illustration, Fig. 222. The cutters a and b were of \|-inch round steel, fitted in the usual way, and held by set-screws c, the bar being placed in a lathe and its ends turned off, so that the cutter a would measure 3\| inches, and b 5\| inches. The end of the bar just fitted the 2-inch hole already bored in the spindle, thereby furnishing a correct and certain guide and support near the cutters. The cutting ends of the cutters were formed as shown at A, Fig. 222, i.e., the face of the cutting edges being inclined 5 degrees and the leading edge 25 degrees, making the angle of the cutting edge 60 degrees, which proved to be a very effective construction, the cutter a enlarging the hole to the extent of taking out about half of the stock and the cutter b removing the remainder. The spindle was then reversed and the operation continued from the opposite end until only a small portion of the 2-inch hole was left to guide the boring bar. The bar was then withdrawn and a disk e fitted to it. This disk was 5J inches in diameter, so as to just fit the enlarged hole and furnish a guide for completing the enlargement of the hole, as shown in the lower illustration. The work was successfully done, a true, smooth hole bored, the two sections of which coincided perfectly. It will be noted that in this job the hole was very large in proportion to the exterior diameter, and a large amount of stock was taken out; in fact, nearly 350 pounds of hard steel. This was removed at the rate of nearly 30 pounds per hour. The plan will doubtless commend itself for similar work, and where there is even a greater difference between the directing hole and the finished bore three or more cutters might be used to advantage. It is frequently the custom to fit flat cutters in elongated mortises made through the bar instead of using a round cutter in a bored hole. The flat cutters will be proper when the boring bar is comparatively small in diameter, as it weakens the bar less than a round hole of sufficient diameter to carry a cylindrical cutter of the proper strength. Still the cylindrical cutter should be used economy. When large holes are to be bored a cross arm is used carrying a cutter on each end. Sometimes two cutters on each end are used, a roughing and a finishing cutter. Sometimes a large hollow boring bar is used, carrying a crossbar or head with two tools. This cross bar is arranged to slide on the boring bar and is fed forward by a screw passing through the center of the bar and having upon it a nut that is connected with the cross head. Such an arrangement is used for boring engine cylinders. These boring heads are often driven by the old " starfeed" arrangement, familiar to nearly all machinists. These elaborate devices for boring are usually constructed for special boring machines and may hardly be considered as a part of the equipment of an engine lathe. Milling may be successfully performed on a lathe by strapping the work to the compound rest, to the carriage or to a suitable fixture attached to either. While not so economical or so rapid as on a regular milling machine, it often proves very advantageous when a milling machine is not at hand or when the machines of the shop are crowded with work so as not to be available. Many light operations of milling may be performed on a speed lathe, with proper fixtures for the purpose, particularly when the work is of brass or similar soft metals. In these cases the speed lathe will often turn out as much work as the plain hand milling machine. Gear cutting can frequently be done on the lathe under similar circumstances to those referred to above. The necessary fixtures for holding and indexing the work may be comparatively simple and economical, a change-gear being frequently used as an index, and many jobs quite satisfactorily done in the absence of a regular gear-cutting machine. in the chapter on lathe attachments. In the absence of a suitable machine designed for the purpose, cam cutting may be successfully done in the lathe, by the use of proper formers. The milling cutter for such operations is carried in the center hole of the lathe spindle, and the cam held by a suit- or face cams. However, the question of cams is one of such great variety, and the devices necessary to properly handle them are so many, a detailed discussion of ways and means for doing the work does not seem proper in this place. The practical and resourceful machinist will find many uses for the engine lathe that have not been here described, and if he is a progressive man he will discover many new uses and new devices for handling the many new kinds of work with which he will be confronted. Whatever new and improved machines he may have available, or however well they may be adapted to his many wants, his principal dependence will be likely to be, in the future as in the past, on the engine lathe, "the king of machine shop tools." Definition of the word engine. What is meant by an engine lathe. The plan of this chapter. The Reed lathes. Reed 18-inch engine lathe The Pratt & Whitney lathes. Their 14-inch engine lathe. Flather lathes. Flather 18-inch quick change gear lathe. Prentice Brothers' Company and their 16-inch engine lathe. The Blaisdell 18-inch swing engine lathe. The New Haven 21-inch engine lathe. Two lathe patents by the author. The Hendey-Norton lathes. Who were the pioneers in quick change gear devices? The Hendey-Norton 24-inch engine lathe. The Lodge & Shipley 20-inch engine lathe. A LARGE majority of the lathes in use in the machine shop or manufacturing plant are what have been known for years as engine lathes. Just why this qualifying designation of engine was applied to them is not clear, although we know that in former times the term engine was applied to many machines, particularly those of the higher class, and very early in the development of the mechanic arts the word seems to have been used to designate almost any kind of a machine. Thus we read in the Marquis of Worcester's "Century of Inventions," published in 1683, of "an engine that may be carried in one's pocket" for blowing up ships; "a portable engine in the way of a tobacco tongs"; "an engine whereby one man may take out of the water a ship of 500 ton," and so on, showing the strange uses to which the term engine has been put in times past, while at a comparatively recent period an indexing machine was called a dividing engine, while Webster says broadly that an engine is "a machine in which the mechanical powers are combined." Recurring to the subject, by the term of engine lathe we mean that class or type of lathes which is usually so denominated mechanically and commercially, and which may be defined as a metal turning lathe, having a back geared head-stock; a tail-stock capable of being set over for turning tapers; a carriage provided with suitable tool-supporting mechanism and having connected with it an apron carrying the necessary gearing mechanism for producing power lateral and transverse cutting feeds; and a lead screw, with suitable gearing for driving it, whereby the usual screw threads may be cut, through its proper connection with the apron mechanism. With this conception of the design, construction, and office of the engine lathe of the present day, the following examples are presented and their special features discussed, with a view to the better understanding of this important machine tool. The engravings, the facts stated, and the dimensions, where the same are given, are derived from the machines themselves or their builders, or both, and the aim is to make the information as correct and the estimate of their practical utility as fair as is possible, so that what is here set down will be of value to the buyer of these machines; to the machinist who uses them; to the draftsman and designer who may desire to know of their individual peculiarities; and to the student who would learn valuable lessons in relation to the design and development of the Modern American Lathe. While it is not expected or intended that the lathes of all makers shall appear in this connection, those of the more prominent builders will be introduced, and to these will be added such others as may possess particularly commendable or novel features, in order that the essential points of the engine lathe may be well and thoroughly illustrated and described, with a minuteness that their importance may demand. Among the many manufacturers of lathes the F. E. Reed Company may deservedly receive the title of "ancient and honorable," not because the product of the concern deserves the name of ancient, but because of the long and honorable career of the establishment which has always stood for good materials, good workmanship, and practical design for every-day tools capable of standing up to the work, year in and year out, with whatever the machine tool market affords. While the company have always built substantial and practical tools, of ample strength and many conveniencies for the operator, they have not been given to the exploiting of mechanical fads and fancies or to going to extremes in any one direction. As an example of the engine lathe built by this company, the 18-inch swing engine lathe shown in Fig. 223 is given. It will be seen that here is a deep and strong bed supported upon the older form of legs instead of cabinets. Upon the front leg is a special cabinet for holding the change-gears which are of the older form of change-gears proper, that is, removable. The feed is by means of a belt upon the well-known three-step cone, with which is arranged a change of gears making six feeds. Lathe after Babbitting. The head-stock is heavy and strong and carries a spindle made from a crucible steel forging which runs in cast iron boxes lined with genuine babbitt metal, as shown in Figs. 224 and 225. properly milled out to fit the housings of the head-stock. After this operation it is bored out and then slotted ready to receive the babbitt metal lining. It will be noticed that these are all " dovetail" slots, the object of this form being to hold the lining metal securely in its place. The babbitt metal is cast into the box, after which it is compressed sufficiently to fill out any shrinkage that may have occurred upon cooling, and to render it more dense and durable. It is then re-bored, reamed, and hand scraped, so as to fit the spindle as perfectly as possible. Constructed in this manner there is nothing coming in contact with the spindle except the babbitt metal, which, when finished, has the appearance shown in Fig. 225. Experience has demonstrated that with proper care on the part of the operator a box constructed in this manner will last for a very long time, and, if properly lubricated, that the babbitt metal will soon " glace" over and form one of the best bearing surfaces obtainable. The spindle is bored out to If inches. The drivingcone is of five steps, the largest being 12 inches and is adapted for a 2\|-inch belt. The carriage is of ample strength and has a long bearing upon the bed, and supports a very substantial compound rest. The carriage is gibbed to the outside of the bed both back and front. The apron is of ample dimensions, so as to afford space for large and strong operating parts, which are few in number and simple in construction. The feeds include an independent rod and patent friction feed. Combined gear and belt feeds are furnished and also an automatic stop motion in connection with either type of feed. There is also provided a simple belt tightener device. The belt feeds are from 25 to 95 per inch inclusive. When a geared feed is wanted the belt can be removed and the feed rod connected with an intermediate gear. Then by changing the gears upon the feed stud of the head-stock, feeds may be obtained from 12 to 125 per inch, inclusive. Even this range of feeds seems rather fine for modern methods of work. The lathe will cut seventeen different threads from 2 to 20 per inch, inclusive. The rack and rack pinion are of steel and capable of disengagement when regular turning feeds only are required. An " offset" tail-stock is furnished. obtain a strong and rigid machine. The countershaft is furnished with patent friction pulleys which can be oiled while running, and with self -oiling boxes which will run six months with one oiling,, and requiring no further attention. This company make a variety of different styles and types of lathes, as well as attachments and accessories, which will be found described and illustrated further on in these pages and under their appropriate headings. The reader is referred to them for further information. Another of the old and reliable lathe building establishments is that of the Pratt & Whitney Company, which has for many years enjoyed an enviable reputation as makers of fine machine tools. While they have been progressive, and have brought out many valuable improvements they have never been prone to exploit mechanical fads, or to put on the market comparatively untried devices of the newest kind suggested by enthusiasts who imagined them capable of marvelous results. They have nearly always produced machines well and carefully designed, and constructed of good material and of excellent workmanship. While the product of the company has been large and varied, a great deal of attention has been given to producing good lathes, a sample of which is given in Fig. 226, which is a 14-inch swing engine lathe of recent design. While rated as a 14-inch lathe it swings nearly 16 inches over the bed, and, as a lathe of that capacity, is heavy and strong, with a deep and heavy bed supported on their well-known design of legs rather than cabinets. Still the net weight of a 6-foot bed lathe is 2,200, which is very heavy for a lathe of these dimensions. The apron is shown in Fig. 227, in which it will be seen that it is of very strong construction, being made with two plates whereby the shafts have a support at both ends. The feed rod is carried in double boxes in which are carried right and left worms, engaging the two worm-gears which operate the feed mechanism. While the use of worms and worm-gears in a lathe apron cannot be commended, and the difficulties which most builders have found with them, have caused their use to be discontinued, this company still retain them and by very good construction render them successful. The lead screw nut is well supported to stand the strain to which it is put, and altogether the apron is an excellent specimen of good material and workmanship. The double plates are a feature that ought to be adopted in all lathe aprons as it adds much to the strength of the mechanism, holds the shafts well in line by supporting them at both ends, and materially increases the wearing qualities of the various parts. While the various sizes as have been given for the lathes of other builders are not at hand, it may be said that all bearings have more than usual diameter and length and the boxes are accurately scraped to fit ground journals. The head-stock is massive and well designed and provided with a five-step cone pulley. pound gearing by which a large variety of feeds may be produced. The thread-cutting mechanism provides for cutting from 2 to 92 threads per inch, and by the use of the translating gears will cut all the usual metric threads. Other lathes of different dimensions and types will be illustrated and described later on in this book and under their appropriate headings. , For information of this kind the reader is referred to the chapters on these subjects. in the development of any type of them we naturally look for those bearing this name. In the improvements of the rapid change gear devices we find the names of Edward, Joseph, Herbert, and Ernest, each of whom have added something new to the "state of the art." In Fig. 228 is given a front elevation of 18-inch swing " quick change gear lathe/' which seems designed to meet the latest requirements, and which is powerful, strong and rigid, and combines a reasonable degree of simplicity with accuracy, ease of operation, good workmanship and material. The head-stock and tail-stock are fitted to the bed with a V at the rear and a flat track in front, thus permitting the cross bridge of the carriage to be deep and strong. As will be seen in the engraving, the headstock is heavy and strong with ample housings for the main spindle bearings, which are lined with genuine babbitt metal, cast solid in the head-stock, compressed, then bored out and scraped to an accurate fit for the ground journals of the spindle, which is made of hammered crucible steel. Its front bearing is 3 inches in diameter and 4\| inches long. The bore of the spindle is 1J inches. The carriage is gibbed on the inside and outside and has ample bearing on the V's, while the tool rests are unusually wide and long, and are supported the full length by the carriage, even when turning the largest diameters. The feed mechanism is of new design and accomplishes in a simple and durable manner, and with as few gears as may be, all the results required in the most modern lathe. In a general way it may be described as attached to the front of the lathe in the form of a case in which a cone of nine gears is mounted upon a shaft, any one of which can be instantly engaged by simply moving the lever in front of the case. Upon another shaft located above the cone of gears and in line with the lead screw is a double clutchgear controlled by the small lever on the top of the gear case. The shifting of this lever to three different positions increases the number of changes obtained by the lower lever to twenty-seven. This number may be doubled by sliding in or out a gear at the end of the lathe, thus giving fifty-four changes in all. An index attached to the front of the gear case shows the entire fifty-four changes, so that the operator may know instantly which lever it is necessary to move, and to what position to set it in order to obtain any of the different threads or the different cutting feeds shown upon the index, the entire mechanism being so simple that the most inexperienced operator soon understands its construction and its operation. The standard threads from 2 to 128, including 11J, and feeds from 7 to 450 per inch, are readily obtained without removing a gear, while provision is made by which odd threads or feeds may unbreakable. The rack and pinion are cut from steel, as are also all the gears, studs and plates in the apron, insuring a great degree of strength and durability even under the strains incident to very heavy duty. This company make the usual variety of lathes as built by other establishments, and all of them are of good workmanship and with the well-earned reputation for good tools. The Prentice Brothers Company have for years built lathes, good lathes, as must be judged by the fact that many hundreds of them have been sold and used all over the country. Among the older and more conservative establishments turning out this class of work, they have yet endeavored to meet the demands of modern methods, and in Fig. 229 is shown one of their 16-inch swing engine lathes, with a quick change gear mechanism and an " offset" tailstock. The head-stock is not as massive as in those of some other builders, though strong enough for most kinds of work which the lathe will be called upon to do. The spindle is of high carbon steel, with 2J-mch by 4J-mch front bearing and a IJ-inch hole in the spindle. The spindle is driven by a five-step cone, arranged for a spindle runs in hard bronze bearings. The quick change gear device contains the "cone of gears," so commonly used in these devices, and also a series of multiplying gears at the end of the head-stock, by means of which fifty-five changes may be made, from 2 to 60 threads per inch, and feed cuts from 10 to 320 per inch. All feeds are positive as no feed belts are used. The carriage and apron do not seem to be of sufficient length or weight to stand up rigidly to very heavy cuts with the use of high-speed tool steel. Neither does the bed seem to be as heavy, at least as deep, as we would expect to find in a modern lathe adapted to doing the heavy duty now expected of such a lathe. The lathe with a 6-foot bed weighs when boxed for shipment 1,850 pounds. The " offset " tail-stock is a very useful feature, which is patented by the manufacturers and about which there has been much dispute with other builders who have made them from time to time. The company make the usual variety of engine lathes of special design for special work as well as their plain lathes. These special machines, as well as various attachments and accessories, will be illustrated and described in future chapters, later on in this book, and attention called to their special features. In 1865 P. Blaisdell began the building of lathes and has continued the business since. While no great efforts seem to have been made to bring out new and novel inventions, the Blaisdell lathes have always been known as machine tools, that are well made, reliable, and practical. that is a good example of their regujftir line of product. The head-stock of this lathe has a cone of five steps which take a 2\|-inch belt. The spindle is made from hammered, cast crucible steel, and is bored out to 1J inches. The boxes are of gun metal or of cast iron lined with genuine babbitt metal, as may be preferred. The back gear ratio is 11 to 1, which is high for a lathe of this swing. for the cross-feed screw. There is furnished a rapid change gear device for feeding from 13 to 339 per inch, and a new and powerful friction warranted not to slip. There is a patented automatic stop on the feed rod. The lead screw will cut threads from 2 to 23, including 11} pipe thread. The net weight of this lathe with an 8-foot bed is 2,400 pounds. This company make a variety of lathes and lathe attachments and accessories, some of which are shown later on in this book, and under the appropriate heading, to which the reader's attention is directed if interested in this class of the product. The New Haven Manufacturing Company are among the older establishments building engine lathes, and for a number of years have built a line of very strong and substantial tools, notable not so much for fine finish as for rigidity and for practical utility, special attention having been given to the quality of the materials entering into them. Figure 231 gives a front elevation of their 21 -inch swing lathe, and Fig. 232 is an end view of the head and bed, showing the feeding and thread-cutting gears. The arrangement of the former is peculiar and the subject of a patent granted to the author. In this case there is fixed upon the outer end of the head-shaft a "cone of gears," with each of which is engaged an idle gear running loosely upon a stud fixed to a revolving plate, secured in any desired position by a spring pin as shown in the end view of the lathe. When in either of the three operative positions, one of these idle gears connects the cone of gears on the head-shaft with a reversed cone of gears running loose upon a stud in an arm of the stud-plate, and one of them engaging with the changing of a pin passing through the hub of the feed-rod gears, another series of feeds may be obtained. The engraving shows a revolving plate carrying but three idle gears. It is obvious that any reasonable number of idle gears may be carried and that by the use of multiplying gears these ratios may be had in several series of numbers. The object of mounting the second cone of gears upon a stud fixed in an arm cast integral with the main part of the stud-plate (shown in its inactive position) is so that when the regular change-gears are mounted upon the head-shaft and lead screw, and an idler placed upon the idler stud, and the studplate raised to an active position for the purpose of engaging the three change-gears thus mounted, the second cone of gears will be thrown out of their active position and the operation of the feed rod stopped. This same device may be applied to the cutting of threads if desired, by the addition of gears to the cone, and the use of multiplying gears to get ratios of 2 to 1, 3 to 1, and 4 to 1. Within the head-stock is a device for handling the reverse gears, consisting of a horizontal shaft operated by the handle seen in the front of the head, and having upon it a cylindrical cam cut with a groove consisting of two movements and three rests, in which is engaged a hardened steel pin fixed in the yoke-plate, carrying the reversing gears. By this arrangement the yoke-plate is readily locked in its "forward," "back," and "out" positions, and held perfectly rigid when moved from one position to the other. This device was also invented and patented by the author. Either of these devices can be operated while the lathe is in motion, without danger of breaking the teeth of the gears. These lathes have hollow spindles and the one shown in the engraving is made to the following specifications. The beds are wide, deep and strongly braced and mounted upon cabinets of liberal dimensions. The width between the V's is such as to form the base of an equilateral triangle, whose apex is the center line of the lathe. The heads are very strong and rigid, having a solid web entirely across under the cone pulley. The spindle is bored out to ^\| inches and runs in nickel bronze boxes. The front bearing is 3i inches in diameter and 5J inches long. The spindles are powerfully back geared and have hardened steel bushings and checknut for taking up the end thrust. Cone pulleys have five steps of 5J to 13f inches diameter, and adapted for a 3-inch belt. The tailstock is very rigid, with a "set-over" for turning tapers and is secured by two heavy steel bolts. The tail spindle is 2f inches in diameter and bored for a No. 4 Morse taper. The carriage is heavy and has a long bearing on the V's, to which it is scraped and fitted the entire length, and is gibbed at the front and back to the outside of the bed. It has power cross and lateral feeds, an automatic stop and a compound rest with a graduated base. The tool is adjusted as to height by a hardened steel concave ring and washer. The apron is very heavy, the operative parts simple and very strong. No worm-gears are used, their usual office being performed by a large bevel gear and two sliding bevel pinions, by which the motion is reversed. This sliding movement also operates a simple locking mechanism by which the thread cutting and feeding operations become entirely independent of each other, and each, when in operation, locks the other out automatically. The six regular changes of feed are 18, 25, 30, 40, 50, and 60 revolutions per inch of, movement for both lateral and cross feed. All feed racks, rack pinion, studs, rod and lead screw, are made of special steel, and all nuts are case hardened. It will be noticed in the engraving of the front of the lathe that all movements, including those of reversing, are controlled by levers in the front of the apron, so that the operator need not, necessarily, leave his place for this purpose. This company manufacture several other types of lathes and lathe attachments, which will be illustrated and described later on in this work and in connection with similar devices built by other makers. It is said in a catalogue now on the author's desk that "the name Hendey-Norton has come to be generally recognized as being the pioneer in that class of lathes made commercially successful, having the mounted system of gearing for thread and feed changes." As to how far this claim is correct, is a proper matter for the mechanical public to judge. The phrase " commercially successful" seems to have been well put in connection with the statement and may possibly be its "saving grace," for it is well known that as early as 1868 Humphreys used the much discussed "cone of gears," and that he wrote in his patent, "I place my gear-wheels upon a shaft A, ranging from the smallest to the largest," while in 1892 Norton says in his patent, "on the shaft A, and within the box B, are secured a series of gear-wheels E, of varying diameters, arranged step-like," etc. As to who was the pioneer may be an open question, as are a great many relating to the matter of patented inventions. In Fig. 233 is shown a front elevation of the Hendey-Norton lathe of 24-inch swing, and is a late development of this establishment. The head-stock is provided with a "tie" from front to rear housing, which gives additional rigidity to the head-stock and prevents undue vibration of the spindle and its work. The spindle, which is bored out to If inches, runs in annular bearings of special metal and having taper bearings for the journals. The front bearing is 3f to 4f inches in diameter and 7^ inches long, while the rear bearing is 3} to 4 inches in diameter and 5J inches long. Both these journals are not only self-adjusting, but adjustable, independent of each other, and allow for contraction and expansion of the spindle without disturbing the adjustment. The bearings are also self-oiling, having automatic oiling rings, running in large reservoirs of oil, with provision for catching the oil and returning it to the reservoir for use over again. The construction of this spindle and its appendages for the smaller lathes is well shown in the longitudinal section given in Fig. 234, which shows a very clever piece of mechanical construction and one well adapted to the purposes for which it is designed. The spindle cone has but four steps instead of five, as is usual with other makers, their diameters being from 6 to 15 inches and adapted for a 3\|-inch belt. The lathe will cut threads from 1 to 56 per inch and has a turning range of feeds from 5 to 280 per inch. The 24-inch swing lathe will turn 15J inches over the carriage. The tool-post takes in tools f by 1J inches. The carriage has a bearing of 34 inches on the bed and is provided with a strong and well designed apron, excepting for the fact that worms and wormgears are still retained as a part of their construction, notwithstanding the fact that even the best construction of this type is liable to injury from the carelessness of the operator and the lack of a plentiful supply of oil. The tail-stock is strong and rigid, and carries a 2\|-inch spindle bored and reamed for a No. 4 Morse taper. The weight of a 24-inch swing lathe with a 10-foot bed is 5,450 pounds, by which it will be seen that it is relatively a heavy lathe, considerably more so than that of many of its competitors. This firm make other types or modifications of their lathes, and also some very desirable attachments and accessories for lathes which are illustrated and described under their appropriate headings further on in this work. The Lodge & Shipley Machine Tool Company have turned out some good examples of modern machine tool building, in the recent types of their engine lathes, showing much consideration and study of the conditions surrounding the manufacturing problems of the present day. This is noticeable in their 20-inch swing engine lathe, a front elevation of which is shown in Fig. 236. In this lathe the back gear quill and pinion are of forged steel instead of cast iron, as usual, whereby great strength and durability may be expected of this part, which in ordinary lathes not infrequently fails and has to be renewed. The cone pinion is also of forged steel. The main spindle is of 55 point carbon-steel and hammered, and has a If -inch hole through its entire length. The front bearing is 3J inches in diameter and 5\| inches long, and both bearings are accurately ground and the boxes have an oil reservoir beneath them from which oil is raised by small buckets attached to a brass ring located midway on the journal, thus insuring abundant lubrication. Gage glasses at the front of the head-stock show the level of oil in these reservoirs, which are deep enough to permit sediment to settle at the bottom out of reach of the oilraising buckets, thus keeping the lubricant on the journal clean and in good condition. The thrust collar is of steel, hardened and ground. The general arrangement and construction of the head-stock, and the gearing contained in the front end of the bed, is well shown in the longitudinal section in Fig. 237, and the end elevation in Fig. 238. In these engravings the location of the "cone of gears" is seen to be in the bed of the lathe instead of in a box or extension in front of it, or partially' in the head as is the case of some of the rapid change gear devices. In Fig. 238 the location of the various handles and levers for controlling the change gear device is clearly shown and their use and operation may be readily seen and understood. The movable or sliding connecting or intermediate pinion, carried by a lever which is held in place by a spring pin entering any one of the line of holes shown in the front of the head-stock in Fig. 236, is practically the same as used in the Hendey-Norton lathe and in others of this type. These changes are very quickly and certainly made, and the mechanism appears to be substantial and durable. braced internally by cross girts The surfaces to which the leadscrew bearings are fastened are planed to receive them and the parts are tongued and grooved to insure perfect alignment. The V's are rounded on top to prevent bruising. In lathes of 22-inch swing and larger the beds are additionally strengthened by a central longitudinal brace, in the top of which is a rack into which a pawl pivoted to the bottom of the tail-stock engages, thus affording a positive brace for holding the latter in position against heavy strains. The rear end of the bed is cut down low enough to permit the ready withdrawal of the tail-stock, which is very convenient when turret slides or similar attachments are to replace the regular tail-stock. The carriage is strong and heavy with liberal length of bearing upon the V's the entire length of the carriage, which is gibbed to the bed its entire length also. In place of an inside V at the front of the bed, the surface is flat for the carriage to find an additional bearing, thus shortening the distance between the supports of the carriage and so affording additional strength and rigidity immediately under that portion supporting the compound rest in its usual position. The V's are kept clean and also lubricated by a specially designed wiper and oiler fastened to the ends of the carriage. This not only insures the proper lubrication but prevents grit and dirt getting between the carriage and the V's, and so destroying their accurate bearing and smooth surface contact. The apron is of ample strength and made specially rigid by three braces through its entire length and a longitudinal brace across the bottom. It is tongued and grooved into the carriage, and firmly bolted to it. No worm or worm-gears are used, a compact arrangement of a large bevel gear and two bevel pinions mounted in a sliding frame taking the place of the older method of construction. There are few gears used in this construction, and all of them are of steel and run on hardened and ground steel studs or shafts. The lead screw passes through the double bevel pinions, and is splined to them by a spline reaching the entire length of the gear sleeve, the edges of the spline being carefully rounded to prevent the possibility of injuring the split nuts, which are made from solid metal and then split, instead of being lined with babbitt metal as usual. These nuts are held in planed grooves in the back of the apron, no clamps or screws being used. This holds them very rigidly under the heaviest strains. In the larger lathes it is, of course, necessary to back gear the operative parts for ease of handling. This is done with few gears, which are made heavy and strong. The lead screw threads are never in use except when thread cutting, the locking out of the thread cutting or the regular feed device being automatically and surely provided for by a simple device. The rear of this apron is shown in Fig. 239, by which its compact form and mechanical design is clearly shown. This establishment builds other types of lathes of very practical and useful forms and equally good design, as well as various attachments and accessories which will be found illustrated and described further on in this book under their appropriate headings, and to which the reader is referred for information of this character. Schumacher & Boye's 20-inch instantaneous change gear engine lathe. Emmes change gear device. 32-inch swing engine lathe. Le Blond engine lathes. 24-inch swing lathe. The Le Blond lathe apron. Complete drawing of a front elevation. The Bradford Machine Tool Company's 16-inch swing engine lathe. The American Tool Works Company's 20-inch. The Springfield Machine Tool Company's 16-inch engine lathe. The Hamilton Machine Tool Company's 18-inch swing engine lathe. The W. P. Davis Machine Company's 18-inch swing engine lathe. THE firm of Schumacher and Boye build a line of well-designed and practical engine lathes, one of which, called by the makers their "20-inch instantaneous change gear engine lathe," is shown in Fig. 240. It will be noticed that the spindle cone has but three steps, respectively 9, 11, and 13 inches in diameter, and adapted for a 3J-inch belt. As the head is double back geared, the requisite number of different speeds is obtained, the back gear ratios being 3i to 1, and 10 to 1. The front bearing of the main spindle is Siinches in diameter and 6 inches long. The spindle has a lT9g-inch hole through its entire length, and reamed for a No. 4 Morse taper. The change gear device is the one patented by Emmes, in 1902. and is very effective as a piece of practical mechanism, and is operated by a front and a top lever, swinging upon centers and carrying index pins which enter any one of a circle of index holes. Sliding pinions are also used upon the feed rod to still further enhance the value of the mechanism by providing for the operating or the disconnecting of the feed rod. The reverse for both feeding and thread cutting is handled at the head, and in the apron, as may be desired. The cutting feeds are locked "out" while threads are being cut, and vice versa. Forty changes of feeds and for thread cutting is provided for. The apron is constructed on simple and strong lines and is effective in withstanding the strains and shocks to which it is subjected. All the gears in it are made from drop forgings. The lathe with an 8-foot bed weighs 3,850 pounds. This establishment makes lathes up to 48-inch swing, those of 32-inch swing and upward being provided with triple geared headstocks which are built very strong, heavy, and rigid. These larger lathes all have the " instantaneous change gear" device, practically the same as that provided for the smaller lathes. The aprons of these lathes are of the box form and of very rigid construction, avoiding overhang as much as possible, and also the straining of pinions and studs. These studs are made of tool steel and run in bronze-lined boxes. The lead screw nuts are also of bronze. The main spindle, in the head-stock, is of 75-point carbon, crucible steel, has a 3J-inch hole, and runs in phosphor bronze boxes. It is reamed for No. 6 Morse taper. The carriage has bearings through ite entire length on the V's, and is gibbed both back and front. The compound rest has an angular feed by power with 12 inches travel. The apron and compound rest have steel gears throughout. The tail-stock is provided with a pawl which travels in a rack formed in the bed similar to those shown by Lodge & Shipley. The 48-inch lathe will swing 31 inches over the carriage. The lathe with a 14-foot bed weighs 17,500 pounds, and is a very strong and rigid lathe. for thread cutting. The company make the usual variety of lathe attachments and accessories necessary to fitting out their lathes with modern conveniences, which will be mentioned later and under headings that follow this in proper order. Many of these have found their way into the best machine shops of this country, and are much appreciated. The LeBlond manufacture of lathes, like their milling machines, are well known in the market, and are noted for their good and careful design so as to properly meet the requirements which they have to fulfil. They are made from a good system of standard plugs, jigs, and templets, by which all the component parts are rendered interchangeable . The spindles are all made from hammered crucible steel and finished by grinding. The boxes on the smaller lathes are composed of phosphor bronze, while those of the larger and heavier lathes are lined with genuine babbitt metal. The lead screws are made from 20-point carbon open hearth steel and are not splined, whereby the accuracy of the 'screw is maintained for good thread cutting. Thread-cutting stops are graduated in thousandths of an inch and right or left hand threads are arranged for by a / reverse in the head. The lateral and cross feeds are automatic and are properly graduated for good work. The aprons are unusually heavy and so arranged that it is impossible to throw in the rod feed and the lead screw feed at the same time. The rack pinion can be freed from engagement with the rack by lowering it out of its engaged position so that there is no undue resistance when thread cutting is to be done. It frequently happens that much friction is caused by these strains upon the moving parts of the apron and cause serious inconvenience and often damage or breakage to the ports, particularly to the rack pinion. The tail-stock set-over arrangement is graduated so that tapers may be readily determined. They are of the overhanging type, frequently referred to as "the English style," whereby the compound rest may be swung around to a position almost parallel with the lathe bed. The feed cones on the 12-inch to 24-inch swing lathes are so arranged that there are tighteners to apply to an improved chainfeed device so that there is none of the usual troubles from feed devices driven by belting. On the larger lathes there is provided an improved chain device, giving three independent feeds on the feed rod, and which can be changed instantly by a lever in the front of the head-stock. While this establishment makes several types of lathes, it will be sufficient for our purpose here to introduce the regular engine lathe, and that of 24-inch swing is taken as a good example and shown in Fig. 241, which gives a front elevation, while Fig. 242 description of this lathe is as follows: The range of threads that can be cut is from 1 to 16 per inch. The main spindle is bored with a 2^-inch hole and the front end bushed for a No. 5 Morse taper. The front bearing is 4\| inches in diameter and 8 inches long. The lathe is driven by a five-step cone, the steps being from 6 to 17 inches in diameter and adapted for a 3J-inch belt. While rated as a 24-inch swing lathe, it really swings 25J inches over the bed and 16 inches over the carriage. As a 10-foot bed lathe takes in 4 feet 4 inches between centers, it is seen that the head-stock and tail-stock occupy a space of 5 feet 8 inches on the bed, giving the opportunity to make both of these important features strong, rigid, and massive. As a 10-foot lathe weighs 5,900 pounds net, it is seen that the weight is 590 pounds per foot. Countershaft pulleys being 16 inches in diameter, and for 5-inch belt assures ample driving power, and which, run at 120 and 165 revolutions per minute, give a spindle speed of 2} to 460 revolutions per minute, which is as wide a range as would possibly be needed in a very large variety of work. Le Blond Lathe. In the end elevation, shown in Fig. 242, the two stud-plates and the system of change gearing is clearly shown, and a good idea is given of the strength and stability of the lathe. The operative parts of the apron of the smaller sizes of Le Blond lathes is shown in Fig. 243, by which it will be seen that they are very simple, and that therefore the parts may be made of sufficient strength to withstand the hard usage to which a lathe is often subjected. The operation of this mechanism is so simple that a detailed description does not seem necessary, although attention is called to the very simple manner of locking the rod feed out when the lead screw feed is in operation, and vice versa. As no engraving of the exterior of a lathe can give a proper and correct idea of its interior construction, a full and complete drawing of a front elevation of this lathe is given in Fig. 244, particularly to illustrate this lathe and in a general way to show the construction of a modern engine lathe of a substantial and practical type for heavy, e very-day work, and showing its general symmetry and good proportions. The Bradford Machine Tool Company have recently developed a line of lathes which compare very favorably with those of other builders and possess some excellent features of strength, durability, and convenience for straight, e very-day machine shop work. In the design and construction of these lathes there are several noticeable features that may well be mentioned. None of them have cabinet legs. The old-style belt feed is used in nearly all of them. One of the exceptions is the 16-inch swing lathe which is adapted for tool-room work and has the rapid change gear device, patented by Johnson, which gives a wide range of turning feeds and thread-cutting pitches. A front view of one of these lathes is given in Fig. 245. The reverse in the head-stock of these lathes does not seem to be particularly effective. A tightening device for the feed belt on most of these lathes is handy and practical. There are other special features which will be noticed later on. The main spindles of these lathes are of hammered crucible steel with adjustable, taper, bronze boxes; the journals (as well as all other cylindrical bearings of the lathe) are ground. In the 16-inch lathe the spindle is bored out to 1J inches. The head cone is of five steps and adapted for a 2J-inch belt. The lathe swings lOf inches over the carriage. The carriage and apron are of ample dimensions and the requisite strength for all practical purposes. The lathe is back geared 9J to 1. A 6-foot lathe weighs 2,000 pounds. clear idea of the construction of the spindle, boxes, thrust bearings, and housings, as well as the form and strength of other parts of the head-stock. The thrush bearing is upon a fiber washer supported by a thrust screw and adjusting nut. A rear view of the apron is shown in Fig. 247, by which it will be seen that worms and worm-gears are avoided and the substantial arrangement of a large bevel gear and double bevel pinions, mounted in a sliding form, takes its place. The locking device for preventing the interference of the thread-cutting and turning feeds with each other is clearly shown. The smaller pinions and the large rack gear are of steel and the rack pinion is capable of being withdrawn when thread cutting is being done. The carriage is scraped to the full bearing of its entire length on the V's and is gibbed at both back and front to the outside of the bed. It is made deep and strong and has power lateral and cross feeds in all sizes of lathes. This company make a variety of different types of lathes and attachments for them, which will be illustrated and described under appropriate headings and later on in these chapters. The American Tool Works Company is a comparatively new concern and is, therefore, unhampered by old traditions and the somewhat inconvenient inheritance which burdens some of the older manufacturers, that is, an accumulation of old designs and older patterns. In Fig. 248 is given an illustration of their 20-inch swing engine lathe, which has a rigid and strong appearance and mechanical design that speaks well for its builders, who have evidently intended to make a lathe of exceptional productive capacity, and ability to stand up to the heavy duty now imposed on such tools reduction of the material. The head-stock is massive and of a symmetrically rounded form. The cone has five steps and takes a belt of rather more than the usual width. The spindle is of high carbon special steel and accurately ground, bored out with a large hole, and runs in a good quality of anti-friction metal boxes, provided with automatic ring oilers. The carriage is proportionately heavy and strong, liberally provided with T-slots, and has a flat top for convenience of bolting down work to be bored or otherwise machined. The bearings upon the V's extend the entire length of the carriage. The compound as are all the sliding contacts of the lathe. The bed is of deep box girder section. The webs are well tied together with cross bars of box form, making the bed very strong and rigid. It is of the " drop-V " pattern, which gives an additional swing of about 2J inches. The V's are far apart and the front tailstock way is flat, which, in connection with the drop-V construction, renders it possible to add an unusual amount of metal to the bridge of the carriage, thus insuring unusual stiffness and rigidity. obviates much of the tendency to twist or lift the carriage off its seat so common in even the best modern lathes where the lead screw is located on the outside of the bed and pulls the carriage by its connection with the apron. The apron is tongued and grooved to the carriage and secured by large and substantial screws. All studs are of tool steel, hardened and ground. All pinions are of steel and are bushed with bronze. All gears are of wide face and coarse pitch. The reverse feeds are not by means of bevel gear and two bevel pinions, as in most modern lathes, but by tumbler gears, suitably controlled at the front of the apron. It is well known that bevel gears and pinions are broken by slipping in and out of engagement when running. In this lathe the bevel gear and pinions are constantly engaged, and therefore can be cut theoretically correct and run in close working contact. A separate splined rod is provided for driving the apron mechanism, thus obviating the necessity of splining the lead screw, as it is well known that no screw will remain true after splining. The screw is therefore simply and solely used for thread cutting and as a further precaution it is placed inside of the bed and has no connection whatever with the apron or its mechanism. The carriage slides, both upper and lower, are fitted with taper gibs which are tongued and grooved into the sides, so that no amount of strain will disturb them. These gibs are adjusted by a convenient screw at each end. The feed screws are provided with micrometer dials. The thread-cutting mechanism is exceptionally well made. All shafts are of high carbon steel and accurately ground. The fourspeed gear box is mounted on the head end of the bed, and by means of clutch members, operated by suitable knobs conveniently located, four changes are instantly obtainable. This, in connection with a cone of eleven gears, mounted on the inside of the bed, any one pf which can be engaged instantly by means of a sliding tumbler gear, makes forty four changes obtainable, without removing a gear. The index is well arranged and comparatively simple to understand, so that the practical operation of this mechanism is more simple and easy than many of the rapid change gear devices. but what is of still more importance, to good fits. That the makers have endeavored to make a particularly good lathe is evident, whatever may be our opinion of the design of the "disc of gears " introduced into the rapid change gear design. The Springfield Machine Tool Company make a variety of engine lathes and special lathes for various purposes that are unique in some respects, and very serviceable lathes for a large class of manufacturing work. Their 16-inch engine lathe is shown in Fig. 249, which is equipped with rapid change gear device, reverse motion operated at the apron, automatic stop for turning and thread cutting, and provided with a friction-geared head spindle. In Fig. 250 is given an end elevation of the lathe, principally for the purpose of showing the rapid change gear device, which is of the type first patented by Edward Flather in 1895, and since used to a considerable extent on small lathes built by various makers and under several later patents, most of which are modifications of that of Flather. lathe, which is of considerable convenience in many classes of work. The lead screw has a telescopically arranged extension, controlled by a hand lever. This extension of the lead screw is reduced at its end to enter the hole in the change-gear, a distance equal to its width, before the clutches with which the change-gears and extensions are fitted come in contact with each other. Thus, when one of the change-gears is connected with the lead screw it ceases to depend upon the disc for support, but is mounted on the lead screw as substantially as if secured by a nut and washer, although it is at other times supported by, and practically journaled in, the circular gear box. As a sufficient range of feeds or screw pitches cannot be obtained by changing gears on the lead screw, only provision is made at the head-stock for various ratios of speed. This is accomplished by means of three pairs of gears, contained in cases, and giving the ratios of 1 to 1, 2 to 1, and 4 to 1; and when the latter two are reversed, the ratios become 1 to 2, and 1 to 4, giving five rates of speed for the fixed pinion which engages with the intermediate gear, necessary for transmitting the motion to the gear on the lead screw. As there is only one pair of gears that can be used at a time, a receptacle is formed in the leg of the lathe to receive the other pairs, one being suspended from a stud projecting from the rear of this cabinet, while the other is similarly placed on the inside of the door, rendering either equally available for use in a moment. thread cutting may not appeal to those machinists who desire a strongly built and strongly geared mechanism, this lathe is still very useful on a large variety of small and medium sized work, of which there is usually a great quantity in the modern factory or machine shop devoted to this class of work, good design and construction, combining the later features that are demanded by modern methods of machine shop and factory requirements for accurate and rapid work as well as a wide range of product. The later designs of this company are heavy and rigid, yet with proper appreciation of the proportioning of the component parts, the machine does not have the clumsy or overloaded appearance sometimes seen in heavy lathes. As a sample of their modern lathes their 18-inch swing engine lathe is shown in Fig. 251. The bed is deep and wide and well braced to resist strains. It is supported upon cabinets of modern design, affording ample cubpoard room for storing tools and small parts. The pads for the lead screw, feed rod and reversing rod bearings are grooved and the bearings planed to fit them, thus assuring true and permanent alignment. The head-stock is massive and of good design, insuring rigidity and preventing vibration and chatter even on the heaviest work which the lathe will be called upon to perform. The spindle is of high carbon steel forging and bored out If inches. It is ground its entire length and runs in phosphor bronze bearings, handscraped to fit the spindle. Anti-friction thrust bearings are provided with an adjusting nut for taking up lost motion due to wear. On this lathe these bearings are provided with hardened and ground steel washers. On the 22-inch swing and larger lathes these bearings are provided with hardened and ground-steel balls which are also adjustable and reduce the friction to a minimum, the ball-races being of tool steel and also hardened and ground. The spindle cone has five steps, the largest being 12 inches diameter, and adapted for a 2f-inch belt. Readily removable gear guards protect the face gear and the back gear from injury by chips, dirt, etc., and the operator from the danger sometimes resulting from these exposed parts. The tail-stock is of the " off set" pattern, that is, cut away in front so as to permit the compound rest to swing around parallel to the V's of the lathe. The tail spindle is 2^ inches in diameter, and is graduated for convenience in drilling. It is of steel and accurately ground and has an unusually long movement. The tail-stock has the usual set-over adjustment for turning tapers. The carriage is massive and strong, and is gibbed at the front, back and center, and is scraped to a solid bearing upon the bed, throughout its entire length. It is entirely flat on top and amply provided with T-slots, so that work to be bored or otherwise machined can be as readily clamped upon it as upon the table of a planer or milling machine. The cross-feed screw has a micrometer attachment, by .means of which, not only can turning and thread cutting be much facilitated, but the drilling of jigs and fixtures may be as readily done here as on a milling machine, so far as laying off accurate distances is concerned, by strapping the work to an angle-plate bolted down to the carriage. In addition to the above feature, the lathe is provided with a rotating indicator or chasing dial, located on the top of the carriage, which enables the operator to catch the thread quickly and properly without reversing the forward motion of the lathe; and permitting him to return the carriage quickly to the starting-point by hand. The compound rest is large and heavy with broad wearing surfaces accurately fitted by hand scraping, and provided with taper gibs. The swivel is graduated in degrees so that it can be quickly set at any required angle. The tool-post is formed from a solid steel bar and has a tool steel screw. The apron is large and strong, and is fitted to the carriage by a tongue and groove. The operative parts are heavy and strong. The rod feed and the thread cutting by the lead screw are independent, and each, when in use, locks the other out of the possibility of becoming engaged, thus preventing the liability of breakage from this source. The feeds are driven by a powerful friction device and are readily reversible at the apron by a single movement. An automatic stop is provided by the addition of a rod running the entire length of the bed, and which operates equally well when feeding in either direction. It operates with either the turning feed or with thread cutting, and enables the operator to chase up to a shoulder, by which feature it is very useful in cutting internal threads, or in boring to a certain fixed depth. It can also be set to prevent the carriage running against either the head-stock or tail-stock, and is therefore a safety device against the serious accidents that sometimes occur from this cause. This device is of great advantage in duplicating work such as the turning of shafts having one or several shoulders, as, the cut once fixed, the stop collar may be set and no further attention paid to the location of the shoulders than would be necessary in an automatic machine. The quick change gear device by which a large number of threads of different pitches are cut, and by which a wide range of turning feeds are obtained, contains the "disc of gears" or circular case, containing eight change-gears and constructed upon the plan first invented and patented by Edward Flather in 1895. In addition to this device the usual multiplying gears are used, being contained in another case which properly protects them. This device is shown in the accompanying illustrations, in which Fig. 252 is an end elevation and Fig. 253, a vertical, longitudinal section, showing the general design of the mechanism, which appears considerably complicated and hardly as strong as such a device ought to be in order to withstand the strains to which it is usually subjected, and therefore liable to get out of order. The device is well made and of good material, and will, no doubt, give as good results as may be expected from this form of rapid change gearing. It will cut 48 different threads from 1 to 56 per inch, and cutting-feeds from 6 to 336, all inclusive, by the use of three removable change-gears. The method by which the various changes are made is necessarily material in its design. This company build a variety of lathes and attachments and accessories for the same, which are illustrated and described under appropriate headings later on in this book, and to which the reader is referred for information concerning them. plain engine lathes, of which a good example is shown of their 18inch swing lathe in Fig. 254. The bed is of ample depth and well proportioned, and is supported on the older design of legs instead of cabinets. The head-stock is of ample dimensions and has a crucible steelforged spindle with a Ig^-inch hole through its entire length, and runs in phosphor bronze boxes, reamed and hand scraped. The front bearing is 3 inches in diameter and 5 inches long. The spindle cone has five steps, the largest being 11 inches in diameter and adapted for a 2J-inch belt. The feed is belt-driven by the usual three-step cone, an arrangement for tightening the belt and multiplying gears whereby six different feeds may be obtained. The change-gears are such as will cut threads from 2 to 32 per inch inclusive. The carriage, apron, tool-rests, etc., are of ample dimensions for the requisite strength. This lathe with an 8-foot bed weighs 2,460 pounds, a fair weight for a manufacturing lathe of these dimensions, which has evidently been the aim of the builders to produce. The same firm make other types of lathes which are illustrated and described in future pages and under their appropriate headings. Some of them have special features to which the attention of the reader is particularly directed. The Fosdick Machine Tool Company, better known as builders of radial drills, have recently commenced the construction of lathes also, and the one shown in Fig. 255 is entitled to special consideration as the aim of the makers evidently is to produce a lathe for practical use that will meet the demand for a good lathe at a reasonable price. This lathe is equipped, as illustrated, with feed box and with compound rest. The bed is made in different lengths from 6 to 12 feet, with cabinet or regular legs, and with or without oil pan. The spindle bearings are 2J and 2J inches diameter; there is a l^-inch hole through the spindle, and draw-in chucks are furnished when required. The bearings are bronze bushed throughout, and constant lubrication is afforded through an endless chain and large oil pockets. Owing to the design of the head, a three-step driving pulley may be used in place of the five-step cone, insuring a more powerful spindle drive when required for high-speed steel work. The carriage has bearing surfaces of ample length and width on the shears, and the apron is of the box-section type, insuring strength and stiffness. The design of the tail-stock is clearly shown, and also that of the follow-rest. The compound rest is designed to receive a heavy tool-post. The compound feed box shown is the well-known Emmes device, giving forty changes, the screw-cutting being just one fourth as coarse. The taper attachment can be placed on any of the lathes without changing the bed or fitting it with brackets, and a turret of pentagon form, for the carriage, can be furnished when desired. All screws on any part of the lathe requiring adjustment are operated with the tool-post wrench. The friction countershaft has self-oiling bearings and oil wells are formed in the friction pulleys. The swing over bed is 16} inches, and over carriage 10} inches. With the 6-foot bed, the length taken between the centers is 34 inches. The width of the five-step cone pulley face is 2f inches, and of the three-step 3\| inches. The countershaft speed with fivestep cone is 120 revolutions per minute, and with three-step cone 250 revolutions per minute. The weight of the lathe with 6-foot bed is 2,000 pounds, which is ample for a lathe of these dimensions, and considerably above the average. The Bradford Tool Company's 42-inch swing triple-geared engine lathe. The American Tool Works Company's 42-inch swing triple-geared engine lathe. The New Haven Manufacturing Company's 50-inch swing triplegeared engine lathe. The Niles Tool Works 72-inch swing triple-geared engine lathe. The Pond Machine Tool Company's 84-inch swing engine lathe. THE 42-inch swing triple-geared lathe, built by the Bradford Machine Tool Company, is a good example of a well designed and massive lathe for the heaviest work to which a lathe of this character will be subjected. With the severe requirements of modern shop methods and the use of high-speed steels the problem confronting lathe builders has been one to tax their utmost energies in the way of good design scientifically and practically worked out; good materials lavishly applied; and good workmanship in every part. Without all of these in a marked degree a lathe may scarcely be classed as modern. As to how well the designers and builders of the Bradford lathe have succeeded in their conditions is to a considerable extent manifest by an inspection of the illustration given in Fig. 256 and a study of the description which follows, as well as to some detailed engravings illustrating the special features of the machine. The head-stock is long and massive, occupying over five feet on the head end of the bed, affording large housings for the spindle boxes and ample space for broad-faced, heavy back gears, and a five-step cone of from 10J to 22 inches in diameter and 5\| inches face. The spindle is of crucible steel and is bored out with a 3-inch hole. It has a front bearing 6 inches in diameter and 10 inches long, and a rear bearing 5 inches in diameter and 9 inches long. The bearings are accurately ground and run in heavy bronze boxes, which are reamed and hand-scraped to a fix, It was probably not an Irishman who wrote in the manufacturer's catalogue that " the back gears are conveniently located in front," however much it may sound like it, as it is a mechanical fact, and being so located applies the power at the proper point. Being triple geared there are fifteen speeds, increasing in proper geometrical progression, and the lathe is provided with three rapid changes of feed for each speed. The coarse screw-cutting arrangement is shown at the left of the engraving, Fig. 257, and is a regular device on these lathes. It consists of a short intermediate shaft in the outer end of the headstock, running in a sleeve adapted to be moved longitudinally. On each end of this shaft is fixed a spur gear, and when the shaft is HEAVY LATHES shifted to its outward position, the gear on the outer end of the lathe spindle communicates motion to the screw. When this shaft is at its inward position, motion is communicated from the cone gear in a ratio of 8 to 1. So that if the lathe is geared ordinarily to cut one thread per inch with the outer gears engaged, ft will, with the inner gears engaged, cut a thread eight times as coarse, or one thread in 8 inches. In cutting very coarse threads the back gears are always used. Running in this manner the strain is taken off the change-gears, and threads or spirals as coarse as one turn in 16 inches can be cut. Swing Bradford Lathe. the bed. The three upper gears are fast to the lead screw, while the three lower $ears are engaged consecutively by a sliding key, controlled by the nut shown at the right of the engraving, and handled by a wrench. These gears are of steel and may be engaged and disengaged while in motion. The apron is massive and well constructed. A rear view of it is shown in Fig. 259, by which it will be seen that it is very simple, and therefore the parts may be made of ample strength. All shafts have bronze-bushed bearings. Independent frictions are used for both lateral and cross feeds, and are reversed from the front of the apron. screw nut are operated by the usual form of cam, controlled by a lever shown at the right hand of the apron in the front view, as in Fig. 256. The end of the sliding rod which carries the forks for moving the bevel pinions is extended to the lead screw nut, where an attachment is made for locking the lead screw nut open whenever either bevel pinion is engaged with the driving bevel gear, and for locking both of these bevel pinions out of engagement whenever the lead screw nut is closed, thus preventing the two types of feed being thrown in at one time. The rack pinion is adapted to be withdrawn from engagement with the rack when thread cutting is being done. hand-scraped to an accurate fit. The inside V's of the bed are lower than the outside V's, by which construction the bridge of the carriage may be made much thicker and stronger, thus adding materially to the strength of the carriage at the point where it is usually the weakest. The compound rest is large and broad, with an ample tool block with heavy tool clamping bars, and having an angular power feed of 12 inches in any direction. The base is graduated and both top and bottom slides are provided with taper gibs and adjusting screws. and has a travel of 16 inches. It has the usual set-over screw for use in turning taper work, and is provided with a rack and pinion device for conveniently moving it to any desired point on the bed. This lathe made with a 12-foot bed weighs 16,500 pounds, by which its massive design and great strength may be judged and by which the points stated in the opening sentences of this description may be more readily appreciated. The American Tool Works Company have recently designed an excellent 42-inch swing lathe intended for heavy work and having a number of good features not usually found in lathes of this capacity. An illustration of this lathe is shown in Fig. 260, which gives a good idea of its massive design and symmetrical outline. Tool Works Company. The head-stock is large and massive with ample housings for the spindle boxes, which are of phosphor bronze carefully fitted to the high carbon hammered steel spindle, which is accurately ground and which carries a five-step cone. As the head is triple geared, this gives fifteen speeds arranged in correct geometrical progression. The carriage is very heavy and strong, long bearing on the V's, and made with a flat top so as to be convenient for bolting down work to be bored. The compound rest is equally strong and provided with heavy clamping straps for holding down the tools. The feed is driven through a quick change gear mechanism which provides thirty-two changes for feeding and thread cutting, the range of threads being from 1 thread in 4 inches to 16 threads per inch, including 11 J pipe thread. The feed range is from 6.4 to 92 cuts per inch. The device is operated while the machine is running, if necessary, by a revolving nut seen at the right of the gear box beneath the head, which moves a sliding key engaging two opposite gears, each being one of a cone of gears which is encased in the gear box. The feed or screw pitches thus obtained are multiplied by the compound gears on the quadrant at the end of the head, it being necessary to change one gear only on the quadrant for each additional thread. This arrangement gives flexibility to the screw-cutting mechanism, making it possible to cut an unlimited number of sizes of threads or worms, either finer or coarser than the range indicated above. An index plate is provided to assist in obtaining the desired feed or pitch. The feed may be reversed in the apron, a feature which is valuable on a long lathe where the tool may be working at some distance from the head-stock. The New Haven Manufacturing Company build a 50-inch swing engine lathe that, while it is a comparatively plain and simple lathe, furnishes as good a tool at the price as any in the market. The effort has been made to build a very massive and substantial lathe without unnecessary complication or finish. This lathe is shown in Fig. 261. The head-stock is very heavy and well designed, and carries a forged crucible steel spindle with a front bearing 8 inches in diameter and 12 inches long, and a rear bearing 6 inches in diameter and 9 inches long, and running in cast iron boxes lined with genuine babbitt metal that is peinned in, bored, reamed, and scraped. The driving-cone has five steps, ranging from lOf to 19\| inches, and adapted for a 4-inch belt. The head is triple geared, giving fifteen changes of speed. All the gears are broad and of coarse pitch, giving ample driving power. The face-plate is heavy and well ribbed, and keyed to the nose of the spindle, and has a broadfaced internal gear bolted to its rear side, from which it is driven by a steel pinion. The tail-stock is constructed with a double set of holding-down bolts, by which means the upper bolts may be loosened and the tail center set over for turning tapers without blocking up the work or danger of its dropping out of the centers. The tail spindle is 5 inches in diameter and reamed for a No. 6 Morse taper. The operating hand wheel is directly in front of the operator and is back geared to the spindle in a ratio of 3 to 1, so as to be easily and conveniently operated. A back geared rack and pinion device permits the tail-stock to be easily moved to any desired position on the bed. The carriage is very heavy and strong, gibbed front and back, with an unusually long bearing upon the bed, and carries a massive compound rest with a long angular feed in all directions^ a graduated base and large hardened straps, supported by spiral springs upon studs, for holding the tool. These straps have projecting ends so that tools may be held outside of the studs, which may be placed either crosswise or lengthwise of the tool block as may be most convenient for the work being done. The apron is built with double plates so as to give shafts and studs a bearing at each end. All feeds are reversible at the apron. A large bevel gear with two bevel pinions is provided in the apron, and an automatic locking mechanism prevents turning feeds and thread-cutting feed from being engaged at the same time. As an extra precaution against the frictions binding and refusing to release properly when a tool gets caught and in danger of breaking or spoiling work, as is liable to be the case on heavy work, or with very heavy cuts, an additional friction is provided as safety device, as the most careless operator is not liable to screw up both frictions beyond the point of releasing under an abnormally heavy strain, in case of an accident which might result in serious injury to the tool, the work, or the feeding mechanism in the apron. The feed is positive, by a series of gears on the head-stock, with the usual change-gears for operating the lead screw, which is splined for "driving the apron mechanism. All sliding surfaces are hand scraped. Taper gibs, with adjusting screws, are used in the carriage and compound rest. The lead screw is made of special steel rolled for the purpose, 2T7g inches in diameter, and cut with 2 threads per inch. Pinions are of crucible steel and all nuts are case hardened. The countershaft has selfoiling boxes. The weight of the lathe with an 18-foot bed is 20,000 pounds, showing it to be a very massive machine for its capacity. Prominent among the manufactures of heavy lathes is the Niles Tool Works who are also builders of heavy machine tools of other classes which have proven very popular on account of their good design, ample strength, generous proportions and excellent workmanship. for heavy work. This lathe is of somewhat similar design to the 50-inch New Haven Lathe shown in Fig. 261, but considerably heavier, not only in proportion to its larger swing but as generally considered, a more massive machine. The head spindle is very large and constructed of cast iron, as is usual with very large lathes. It is driven by means of the heavy internal gear on the face-plate only, as the cone runs upon a separate shaft provided for that purpose. The face-plate, which is very heavy and strongly braced by ample radial ribs on its rear side, is keyed to the head spindle and is not ordinarily removable. The head-stock is triple geared by strong and heavy gears with wide faces. Thus fifteen speeds are provided for with ample space on the five-step cone for a wide driving belt. in the head-stock by means of a sliding pin which handles the connecting devices of the change gearing. The lead screw drives the feeding mechanism without using the threads cut upon it, through the medium of a short feed rod, located in the apron. This method avoids the use of a long feed rod with its many supports and the attendant inconvenience which is of much greater moment than in those used for the much larger and heavier lead screw. The bed is very broad and massive and furnishes ample support for the heavy head-stock and its weighty appendages, the long and broad carriage with its compound rest of ample proportion, and the massive tail-stock, as well as for the four-jawed center rest which is furnished with this lathe. The tail-stock is broad and heavy and carries a large tail spindle, moved by a system of miter and spur-gearing operated by a large hand wheel at the front side, and within convenient reach of the operator. The tail-stock is secured to the bed by four heavy bolts and a pawl engaging in a rack, cast to the bed on the center line. While the tail-stock is unusually heavy it can be readily moved along the bed upon friction wheels, which are easily put in contact with the bed by means of levers provided for that purpose. The usual set-over device is provided for turning tapers. These builders make much larger lathes upon the same design, and also upon special designs adapted for making large guns, ingot slicing, machining large forgings such as crank-shafts and the like. Of this character they build lathes swinging 90, 100, 110, and 120 inches, and of any length of bed that may be required. An excellent example of heavy lathes for handling large forgings such as crank-shafts and the heavier castings coming within the capacity of such a machine is the 84-inch swing lathe, built by the Pond Machine Tool Company, now operating in connection with the Niles Company. It is shown in Fig. 263. It really swings 86 inches over the V's and 67 inches over the carriage. The lathe is designed with ample provision for the immense strains to which such a lathe is subjected. As will be seen by an examination of the engraving, the head-stock is unusually massive, with liberal dimensions of the housings for the front and rear boxes of the main spindle, which is a matter of prime importance in any lathe, and more particularly in one designed for very heavy work. Attention is also called to the massive construction of the compound rest, which is much stronger and more rigid proportionally than that of the 72-inch swing lathe, built by the Niles Works and shown in Fig. 262. The carriage has a very long bearing on the bed and is made deep and heavy, as should be the case with this type of lathe. An objectionable feature is that of locating apron gears in front of the apron rather than between the apron plates, out of the way of the operator and beyond the reach of ordinary accidental injury to themselves. This should be avoided as far as possible in all lathes. geared device for moving the spindle, by which the hand wheel is placed at the front of the tail-stock and within easy reach of the operator. The base is secured to the bed by four bolts in the usual manner, while the dividing line between the base and the top casting carrying the spindle is placed high up and the top secured by four other bolts. By providing this double set of bolts the spindle may be set over for turning tapers by loosening the upper set of bolts only, leaving the main casting or base still firmly secured to the bed. Thus it is not necessary to block up or to remove the work from the lathe when setting for tapers, which is of considerable advantage, particularly on the heavy work which this lathe is designed to do. centers. All its spindles are mounted in bronze bearings. The head spindle has upon it a thick flange of large diameter to which the face-plate is bolted in addition to being forced on. The cone has six wide belt steps of large diameter. It is mounted on the face-plate pinion shaft, is back geared and geared in to an internal gear on the face-plate, giving twenty-four changes of speed. The sliding head has a set-over for taper turning, held independently by four bolts, thus allowing adjustment without unclamping from the bed. It is provided with a pawl engaging a rack in the bed and is easily moved by gearing engaging a steel rack. "The bed has three wide tracks, with the lead screw between them, bringing the line of strain nearly central, and is sufficiently wide to support the tool slide without the latter overhanging its front side when turning the largest diameters. The carriage has long bearings on the bed, is gibbed to the outside edges, and can be clamped when cross-feeding. It is provided with a tool slide having compound and swiveling movements; also with screw-cutting attachment and automatic friction longitudinal, cross and angular feeds. "If either of the feeds, screw-cutting attachment, or rapid traverse of carriage and tool slides by power is in use, it locks out all others. The direction of the feeds may be changed at the carriage. Screw-cutting attachment and feeds are connected to the head spindle by three gears and a sliding key, giving three changes without changing gears. The carriage gearing is driven by a spline in the steel lead screw. The thread of the lead screw is used only for screw cutting. The gear engaging the feed rack can be disengaged when cutting screws, thus preventing uneven motion, caused by the revolution of the feed gearing." Prentice Brothers Company's new high-speed, geared head lathe. A detailed description of its special features. A roughing lathe built by the R. K. Le Blond Machine Tool Company. Lodge & Shipley's patent head lathe. The prime requisities of a good lathe head. Description of the lathe in detail. The capacity of the lathe. A special turning lathe of 24-inch swing built by the F. E. Reed Company. A two-part head-stock. The special rest. Its two methods of operation. Its special countershaft. The Lo-swing lathe, built by the Fitchburg Machine Tool Works. Its peculiar design. A single purpose machine. An ideal machine for small work. Builders who have the courage of their conviction. THE Prentice Brothers Company have recently brought out a new high-speed geared head lathe, that possesses some valuable features and is worthy of careful consideration. It is well designed to meet all the most rigid demands of modern shop methods that may be made upon a lathe of this character, and is strongly built to withstand all the shocks and strains to which it may be subjected. Apart from its great power, the machine is interesting mechanically in its arrangement for procuring eight spindle speeds from a single speed countershaft, thus always furnishing an equal belt power no matter what spindle speed is in use. It is also of much interest in that it presents a new modification of the quick change feed device. The lathe is shown complete in Fig. 264, and the details of the head-stock, feed gears, and quick change gear mechanisms in Figs. 265, 266, 267, 268, 269, 270, and 271. A careful study of these details will be interesting as giving a clear insight into the prominent features of the device. As will be seen by referring to Fig. 265, four changes of speed are obtained between the pulley shaft and the spindle through an arrangement of gears and friction clutches, The back gears never travel fast enough to render it impracticable to use a positive clutch for this purpose. The result is a ratio of 6 to 1 between the spindle and any friction while the back gears are in use. The driving pulley, which is located on a back shaft, drives the spindle by means of spur gearing. The pulley carries a 4-inch belt, which runs at a speed sufficient to transmit 15 horse power. The eight changes of speed are obtained by means of the levers A, B, and C, shown in Figs. 266 and 267, and also at the front of the head-stock in Fig. 264. This arrangement of the several operative parts is such that there is no danger of engaging conflicting spindle speeds at the same time. On the pulley shaft D, in Fig. 265, which is situated at the back of the head-stock, and revolves at a constant speed at all times, are two friction clutches E and F, either of which may be operated by the lever A, which slides the friction spool I along the shaft D, for the purpose of engaging the clutches at the right or the left. Between the head spindle and the pulley shaft D is located a secondary shaft G, which carries two gears of different diameters, engaging with corresponding gears upon the pulley shaft D, and also gears which are fixed to the hubs of the friction discs J and K. These friction discs run loosely upon the quill L, L, which is itself loosely journaled upon the head spindle and which carries the friction disc L1 at its end. The friction rings M, N, are keyed to the quill L. The friction ring 0 is keyed to the head spindle. E, M, and 0, driving directly; with the frictions F, N, and 0, driving directly; with the frictions F, M, and 0, driving through the intermediate shaft G; and with frictions E, N, and 0, also through the intermediate shaft. The back gears and the spindle-driving gear W run constantly, while the friction spool I is engaged with either friction E or F. By engaging the friction spool and clutch P, which is keyed to the lathe spindle, with the spindle driving gear W, the back gear speeds are obtained. If desired, the lathe is furnished with a two-speed countershaft, to double the number of speeds to 16. The device for changing the feed and for the cutting of screw threads is a radical change from the swing intermediate gear type, as it does away with the raising and lowering an intermediate gear sweep and sliding the intermediate gear laterally to engage with feed gears on the end of the head and bed. A pull spline and spring spline in combination replace the older mechanism. 268, upon which four gears are splined. The shaft is supported at its outer end in a brass bushing mounted upon the gear guard. This shaft with its gears revolves at the same speed as the main When it is desired to change the rate of feed, the pull spline C being moved laterally causes the spring spline to be withdrawn from a slot in the bushing on the feed gear, throwing that gear out of use. When the spring spline passes the pin E it immediately engages the next gear. The form of the driving end of the spline makes this action against the pins possible. The gears G, G, in Fig. 268, drive the gear H in Fig. 270, which is fastened to the shaft J, on which is mounted a yoke carrying a sliding intermediate gear, which engages with the several gears mounted on shaft K. There being 11 gears in this bank, 44 changes of feed are obtained. Sliding on the end of shaft K in Fig. 270 is the gear L, which by means of a handle on the front of the bed may be engaged with either gear M on the feed rod or gear N on the lead esting in tracing the line of motion produced by these gears. A roughing lathe, built by the R. K. Le Blond Machine Tool Company, is shown in Fig. 272, and is principally interesting from the strength of its parts in proportion to the dimensions of the work that it will accommodate. This lathe is built of 18, 21 and 24-inch swing, and has an extra large spindle which runs in genuine babbitt metal bearings. The carriage is much heavier than an ordinary engine lathe, and is extended out both back and front for additional bearing for tool rests. Of these there are two, one in front and the other at the rear. The front tool rest has an extra movement in line with the slide. The back tool rest has an extra movement at right angles to the slide. Both of these are moved by a single screw moving towards or away from the center together. The tail-stock is fastened to the bed with four large bolts, clamping it as far forward as possible. The feed is positive geared and is changed by means of lever shown in front of the bed, giving three changes, and can be stopped automatically at any point desired. By tripping it with a small handle on the front of the apron the carriage will proceed without removing the stop, and keep on until it comes in contact with the next stop. chips from the floor. Countershaft has double friction pulleys. This lathe is intended for heavy and rough work, as, for instance, rough turning forgings and heavy pieces of cut-off work that requires to be largely reduced in diameter with a heavy roughing cut. With the present low price of machine steel there is a good deal of the latter class of work to be done, and it can be done much more quickly and economically in a lathe of the class here shown than in the usual engine lathe, and its use saves the unnecessary wear when such work is done on the more expensive lathe. It was this idea that induced the design and construction of the so-called " rapid reduction lathes," which have come to be popular with manufacturers, not only on account of their economical expenses, but high efficiency. Turret lathes are sometimes used in a similar manner, cutting off and roughing out the pieces from the bar stock, and are very efficient in doing this class of work. The first cost of these machines, however, is much more than that of the plain roughing lathe. The Lodge & Shipley Machine Tool Company build a lathe with a head-stock that is a radical departure from the usual form of cone-driven lathes and which is entitled to special consideration. It is the result of much experimenting and is covered by patents. Commercially they call it their " Patent Head Lathe." It is an outcome of the recognition by the builders of tha demand for a much more powerfully driven lathe for the use of modern highspeed lathe tools. The manufacturer of the lathe says: "Our aim in its design has been to provide this power in such a manner that all the functions of the regular type would be retained, but the head would have wearing qualities, in addition, proportionate to the increased service expected of it. To this end we believe the observance of the following conditions to be of the highest importance : First, the spindle bearings, upon which the accuracy of the lathe is dependent, should not be subjected to the change of alignment by carrying the pull of the belt. Second, more force at the cutting tool should be secured by the use of wider belts, instead of through higher gear ratios. Third, the possibility of running the lathe 'out of gear' should be provided for in cases where finishing cuts are desired. Fourth, speed changes should be secured without the necessity of shifting belts. Fifth, the lubrication of the bearings should be automatic and positive." with the main spindle and the gear covers removed in order to show the construction of the driving mechanism. Power is applied through a wide-faced pulley of large diameter which is keyed to a sleeve revolving in the two central bearings of the head-stock. At one end of this sleeve is a jaw clutch, and at the opposite end two gears of different diameters. The main spindle passes through this sleeve without coming in contact with it, having about an eighth of an inch clearance, and revolves in the two outer bearings, that is, the extreme front and the extreme rear bearing. It is connected to the driving sleeve for direct belt speeds by the clutch, and for the back gear speeds through either back gear, according to the speed desired. A lever, convenient for the operator, engages or disengages the clutch. As there is no contact between the driving sleeve and the spindle except through the clutch, the pull of the belt is all carried by the two central bearings. Sufficient clearance is provided in the clutch to prevent any of the belt strain being communicated through it to the spindle. The spindle bearings are thus relieved of all wear due to belt pull and their life greatly prolonged. By actual experiment with a 20-inch lathe it has been shown that the pressure exerted by a belt on spindle bearings was 17.6 pounds per square inch of bearing surface, while the total pressure exerted by the belt upon a spindle between bearings which effect the alignment of the spindle was 393 pounds. In the lathe under consideration this was entirely eliminated. In the ordinary type of engine lathe the narrowness of the driving belt compels the use of the back gears for all cuts but the lightest ones, and on small diameters. To provide sufficient force at the tool for heavy cuts, this back gear ratio must necessarily be a high one, and, as the speed at which the cut is taken is reduced in the same ratio as force is gained, it is apparent that a heavy chip cannot be removed at a high speed unless the speed of the cone pulley is increased to an enormous rate. When this is done, the fact that it revolves directly on the spindle, where it is impracticable to maintain an adequate supply of oil, soon causes excessive friction and is liable to stick the cone pulley. In the lathe we are considering the great width of belt used delivers sufficient force at the cutting-tool for heavy cuts through a comparatively low back gear ratio, in consequence of which the spindle speeds may be proportionately higher. An additional set of back gears of very low ratio is provided for cuts which are slightly beyond the capacity of the open belt, but which do not require the full force afforded by the high ratio. Thus it will be seen that high speeds can be secured through the back gears without the necessity of revolving the driving pulley at the enormous rate required of a cone pulley to perform the same work. In addition the construction of its bearings is such as to permit of perfect lubrication, which has received a great deal of attention, and the manufacturers claim that the spindle will run a month with one oiling. Deep oil wells, holding about a pint each, are formed in the casting under the centers of the bearings of the spindle and driver sleeve, and are connected with gage glasses at the front of the head-stock for the purpose of showing the height of the oil. The oil wells are filled through these gage glasses, which allows any sediment or dirt which the oil may contain to settle to the bottom and not be deposited on the revolving journals where damage would be liable from cutting. At the center of each journal is attached a brass ring with four projections, on the principle of the bucket pump. As the journal revolves these buckets dip into the oil in the well, and, passing over the center of the bearing, pour the oil over the journal. Suitable ducts distribute the oil lengthwise of the bearing and return it to the well to be used again and again. This method provides a certain system of lubrication without regard to the speed of the revolving spindle. The back gearing is designed with ratios to give a uniform progression of speed from the slowest to the fastest. The two back gears are connected to the back gear shaft by spline and key, and are easily moved lengthwise to engage with their respective gears on the driving sleeve. The back gear shaft and pinion are made of forged steel, thus insuring the requisite strength and wearing qualities. The journals for the shaft are placed at either end, where they revolve in bushings provided with oil reservoirs and the same system of oiling as that for the spindle and driving sleeve. The end thrust of the spindle is against the rear housing of the head-stock by means of a large cast iron collar keyed fast to the spindle, between which and the faced inside of the housing are interposed two bronze washers placed on either side of a hardened steel washer of like diameter. This distributes the friction to four contacts, each composed of two dissimilar metals, and forming a very efficient device for the purpose. a wide range of speeds may be obtained. In Fig. 274 is shown a front elevation of this lathe with the gear covers removed so as to show the head-stock assembled and in running condition. The gear covers are of cast iron and cover and protect all portions of the head-stock mechanism, except the wide-faced driving pulley. This will show the relative importance which a head-stock built according to this system holds to the other constituent parts of the machine. It also shows the very considerable added length necessary for the head-stock, and therefore the reduced length between centers when the same length of bed is considered. But while the capacity of the lathe, so far as length between centers is concerned, is relatively much less, the real capacity of the lathe for producing work, good work, is so vastly increased that the production of this head may fairly be considered as adding machine shop tool. A 24-inch special turning lathe is built by the F. E. Reed Company that is designed for reducing large amounts of metal at one turning, using the high-speed steel tools, and is an unusually stiff, strong, and powerful machine. The head-stock is made in two parts to admit of a cone pulley as large as the lathe will swing over the bed. It has a large, forged steel spindle, the front bearing of which is 4J inches diameter by 9} inches long, and runs in babbitt lined bearings. The spindle is strongly back geared. The cone pulley has five sections, the largest of which is 20 J inches diameter, driven by a 3i-inch belt; then with the two friction pulleys on the countershaft this number of speeds can be doubled, making a total of twenty speeds which can be had belt if desired. A special feature of this lathe is the rest. It is provided with two patented elevating tool-posts, each having a universal toolholder, in which any size of steel can be used to advantage, and so made that they admit of adjustment up and down while the tool is under cut. Each tool-post is moved from the front by a separate screw, and the rear tool-post is provided with a screw for adjustment crosswise of the rest. These tools can both be used to turn to the same diameter by dividing the chip; or, they can be used to reduce the diameter, removing large amounts of stock, working one tool in advance of the other, each tool turning to a different diameter. There are two methods of operation : First. When it is desired to do rapid turning, and where it is not necessary to largely reduce the diameter, the front tool is brought up to the work and set so it will reduce the piece to the required diameter. Then the rear tool is adjusted to a point where it will turn to the same diameter as the front tool, after which it is adjusted by means of the cross adjusting screw so that it will divide the chip. Then by means of the small lever shown at front of lathe a coarser feed is engaged. Second. When large reductions in diameter are desired, the front tool can be set to remove the required amount of stock, and the rear tool set to follow the front tool for removing a second large chip from a different or smaller diameter. Arranged for either of the foregoing operations the lathe will turn off twice the amount of stock that can be removed at one turning in the ordinary 24-inch engine lathe, using the high-speed turning steels. The countershaft is furnished with two patent friction pulleys for two speeds, 200 and 250 revolutions per minute. These pulleys are 18 inches diameter and take a 5-inch belt. The pulleys are so arranged that they can be oiled while running, thereby saving loss of time, danger, and annoyance in running off the belts, which is an important consideration where a number of lathes are in use. The countershaft is also furnished with self-oiling boxes. This lathe is shown in Fig. 275, wherein its ample proportions and excellent design may be seen and appreciated. It is undoubtedly one of the best lathes of its kind, and for this particular and important use, now on the market. With a 10-foot bed this lathe weighs 7,390 pounds. A special lathe has been brought out by the Fitchburg Machine Works at a comparatively recent date that is unique in construction in a number of ways, and for these reasons, as well as for its claim to a large production of work within a limited range, it is worthy of considerable attention. It is called the "Lo-swing" lathe, and has a capacity from J to 3} inches in diameter and up to 5 feet in length. The builders say: "We have purposely limited the range of work handled in order to increase productive capacity — a Lo-swing will do from three to four times as much work as an ordinary lathe in the same time. "The extremely low swing and the single slide tool carriages, all four of which can be employed simultaneously, are distinguishing features of this machine, and the greater driving power, greater stability, the accurate control of tools and work, made possible by this construction, result in such rapid and economical production of work that the Lo-swing is already an acknowledged costreducer for the shop. " The greater driving power, greater stability, the accurate control of tools and work, the low swing and small carriages, made possible by thus limiting the range, result in such rapid and economical production of work that the Lo-swing stands in the front rank as a cost reducer." Figure 276 is a perspective view of this lathe, and gives a good idea of its general appearance. The aim of the builders is to so design the lathe as to limit its range of work so narrow as to make it "a single purpose" machine, that is, to confine its operations to one single class of work and then produce as much of that one class as possible. Its two distinctive features are first, its very low swing, just enough to clear a 3J-inch bar; and second, single tool slide carriages, several of which may be simultaneously employed. Tfae ideal machine for turning small work, which must be turned on centers, should have the tool mounted on a low rest with the guiding rail as close to the work as possible, and with the cross-feed screw located directly back of the cutting-tool so that a change of the screw would surely and positively effect a corresponding change in the position of the tool, .and so that variation under working tion of the tool. While these conditions have been presented, time out of mind, by the mechanical engineers who have studied the lathe question and its relation to the regular lathes built and put on the market, the lathe builders have been slow to adopt such radical changes as would properly accomplish the required result. servative methods of other lathe builders in producing this machine. While it is yet too early to determine what will be the success of this venture, and how popular it may become with manufacturers requiring such a machine, it seems at this writing to have a bright future before it as a practical manufacturing machine, and its builders are certainly entitled to considerable credit for having the courage of their convictions in bringing it out. The F. E. Reed turret-head chucking lathe. Its special features. A useful turning rest. The Springfield Machine Tool Company's shaft-turning lathe. The three-tool shafting rest. The driving mechanism, Lubrication of the work. The principal dimensions. Fay & Scott's extension gap lathe. Details of its design. McCabe's double-spindle lathe. Its general features. Its various sizes. Pulley-turning lathe built by the New Haven Manufacturing Company. A special crowning device. Its general design. A defect in design. The omission of a valuable feature. Pulley-turning lathe built by the Niles Tool Works. A pulleyturning machine. Its general construction. Turning angular work. Convenience of a bench lathe. The Waltham Machine Company's bench lathe. Its general dimensions and special features. A grinding and a milling machine attachment. Devising special attachments. Reed's 10-inch swing wood-turning lathe. Special features of design. Popularity and endurance. The countershaft. Inverted Vs. THE F. E. Reed Company build a number of sizes of turret head chucking lathes, with both plain and back-geared headstocks, and cylindrical turrets placed upon a lateral top slide supported by a heavy base or bottom slide fitted to the V's of the bed. In Fig. 277 is shown one of these lathes with a back-geared head-stock. The spindle, which is of crucible steel, is bored out to 2 inches and has a front bearing 4 inches in diameter. It is fitted with a three-step cone, the diameters of which are 7f , 11, and 14 inches and carries a 3J-inch belt. The turret is 12 inches in diameter and has four holes, 2 inches diameter. It is arranged to be turned by hand, although, of course, may be made automatic in its action if desired. The turret slide is 38 inches long and has a movement of 17 inches, with an automatic feed and stop device. The turret shoe or bottom sli^e is 26 inches long. The patented rest is a special feature. It is hinged to a slide which is bolted to the back side of bed, and adjustable for any length of work. It carries bushing for holding chuck drills, and is arranged to be turned back out of the way instantly to allow the use of other tools in the turret. This is a strong, powerful lathe, and with the Guilders system of three-lip drills and reamers, fully one third more holes can be made than with ordinary turret chuck lathes. The lathe is built heavy and strong and the parts are well fitted and of good material, so as to stand the hard and continuous service to which such a machine is subjected, as well as the neglect and the The turning of shafting requires not only a specially designed tool carriage, carrying three tools, but there should be a special arrangement of the feeding mechanism, specially long centers, and special devices for supporting the long shafts near the cutting-tools as they are being turned. These conditions have been considered and provided for in the 24-inch swing shafting lathe, built by the Springfield Machine Tool Company, which is shown in Fig. 278. shaft to a similar gear on the driving shaft running the entire length of the bed. In designing the three- tool rest, two of the tools are placed on the left and one tool on the right of a massive follow rest. All of these tools are on the front side of the shaft to be turned, in which position they are convenient to manipulate and their cutting edges are always in plain sight. Some builders put one of these tools in a reversed position in the rear of the shaft, to be turned so as to balance the cutting strains better. There is a driving mechanism arranged at the tail-stock as well as the head-stock, which is very convenient when turning shafts very long in proportion to their diameter, and hence subject to unusual torsional strains. Either of these drives may be thrown into gear instantly, Thus in turning a long, slim shaft, that half near the tail-stock may be turned with the tail-stock driving mechanism. As the tools pass the center of the shaft the tailstock drive is thrown out of gear and the head-stock drive engaged, The saving of time by having the drive applied near the point of resistance to the cutting tools should be considerable on long work. Attention is called to the substantial manner in which the tailstock spindle is clamped in order to render it suitable for supporting the driving mechanism, and also for furnishing a large wearing surface for the supplemental face-plate and face gear upon the body of the tail-stock. The method used for guiding the shaft in the follow rest is to pass it through a split cylindrical collar, one of which is furnished for each diameter of shaft to be turned. These collars are broad enough to furnish sufficient bearing surface to the shaft to prevent undue friction or cutting, while they hold the shaft accurately in place and can be closed up with an adjusting screw to compensate for any wear that may occur by continued use. As a copious supply of lubricant is essential in shaft turning, a duplex single-acting plunger force pump is bolted under the water reservoir of the shafting rest, from which it receives its supply. Water is forced up into a tank sufficiently elevated to bring the supply tubes to the proper height above the cutting- tools. This tank is arranged with an automatic relief valve susceptible of adjustment so that any desired pressure can be obtained. By this arrangement the operator need not give any attention to the pump when he starts up the lathe, inasmuch as it provides automatically for the overflow should no water be required. The water used may have added to it soda, soap, or any of the usual ingredients used for such purposes. On this lathe, when arranged as above, it is only necessary to remove the shafting rest, replace the compound rest, disconnect the tumbler gear under the head-stock, and the lathe is ready to perform any of the ordinary functions of an engine lathe, thus making it a valuable convertible lathe where there is not shaft-turning work to keep it going all the time, although that is the primary object in designing it and that is supposed to be its chief function. The long centers shown are necessary as they must reach through the bushing in the shafting rest, which is mainly depended upon to support the shaft during the process of turning. They are bored and reamed to the diameter which the shaft is turned by the second tool (the first tool being a roughing tool), and then split so that by a little compression, exerted by a set screw provided for that purpose, the bushing is held in position and the shaft is accurately supported in its proper place. Some of the principal dimensions of this lathe are as follows: Front bearing of main spindle, 4 inches in diameter and 7 inches long. Hole through the spindle, 1J inches. The driving cone has five steps, the largest of which is 16 inches in diameter and adapted for a 3J-inch belt. The ratio of the back gearing is 12 to 1. The feeds are from 4 to 65 per inch. The lathe turns shafting up to 5 inches in diameter. Five feet of the length of the bed is occupied inches in diameter and has a travel of 9 inches. This lathe with a 35-foot bed (to take 30 feet between centers) weighs, 13,000, pounds, showing its substantial construction and ability to handle heavy shafting successfully. Fay & Scott are the builders of an extension gap lathe which has the advantage over a lathe whose bed is cast with a fixed distance in the width of the gap, as shown in Fig. 23. In this case there is a base or lower bed, as shown in Fig. 279, upon which the bed proper, or upper portion, is mounted and upon which it slides. By this arrangement the "gap" can be widened to any distance desired, or it can be closed up entirely, converting it into an ordinary lathe. This is a great convenience on heavy work, particularly in a jobbing shop, or in any shop where there is a great variety of work to be done upon which large diameters occur, as the fly-wheels on crank shafts, large pulleys, and similar work. The lathe is triple geared direct to the face-plate, the triple gear ratio being 34 to 1. The carriage is extended for turning work the full swing of the lathe, and is supported by an angle bracket with an adjustable gib on the lower bed. The lathe swings over the bed 28 inches, and through the gap 52 inches. The 12-foot lathe takes 6J feet between centers when closed, and 10 J feet when extended. The gap opens 4 feet, and every additional foot of bed lengthens the gap 6 inches. a lathe with two spindles for th& purpose of furnishing a lathe of large and small capacity, the fact still remains that the two-spindle lathe, brought out a number of years ago by J. J. McCabe, has achieved a notable commercial success and many of them are in use. is shown in Fig. 280, which gives an excellent idea of this machine. It is impossible in a lathe of this character to so design it that it shall present a symmetrical contour, however we may view the matter, yet it seems as if the tail-stock of this lathe might be somewhat improved in its outlines without detracting from its strength or usefulness. The lathe has a deep and strong bed and is well supported by cabinet legs, the one under the tail-stock being arranged to swivel to fit an uneven floor. The head-stock might be somewhat stronger to advantage, particularly for the 48-inch swing spindle, but it is probably a fact that the large swing feature is more in use for boring and similar work than for heavy work requiring the full swing. Still we know personally that much large and heavy work is done on these lathes, and that in shops where such work is an exception rather than the general rule the lathe proves a valuable addition to the equipment, saving the expense of a large lathe which, under ordinary circumstances, would be engaged on useful work only a fraction of the time. either the small or large swing, requiring only the necessary changing of face-plates to suit the work, the compound rest and the center rest require the use of a building-up or blocking piece when the change from small to large swing is made, and vice versa. Naturally the compound rest will not be as stiff and rigid as that of a regular 48-inch swing lathe, as the compound rest proper is designed upon lines and with dimensions that appear to be a compromise between those of a 26-inch and a 48-inch swing lathe. The carriage has long bearings upon the bed and is of ample strength, as is also the apron and its operative parts. The feed is geared and consequently positive and capable of the necessary changes expected in a lathe of this character. The head-stock cone is of five steps and takes a 3J-inch belt. The head-stock is arranged with four adjusting screws, by means of which it may be at any time lined up parallel with the ways of the lathe. The head-stock 'and the tail-stock fit on flat surfaces instead of V's, thus increasing the normal swing of the lathe without raising the head spindle, as the inside V's are omitted. The tail-stock is fitted with a gib on the front side for the purpose of taking up any wear that will in time take place, and is provided with the usual set-over screw for turning taper work. The upper spindle is triple geared and has double the ratio of back gearing of the lower spindle, while the internal geared faceplate shown in the engraving is furnished as an extra and gives a ratio of 72 to 1, giving ample power for large work. This lathe is also made 24-40 inch, and 26-44 inch swing, while the one here illustrated and described is also furnished with permanent raising blocks or built up solid to swing 32-54 inches. It is also arranged to run with an electric motor when this method of driving is preferred. A pulley turning and boring lathe is shown in Fig. 281, and is built by the New Haven Manufacturing Company. There are several features in this lathe which make it of unusual value, not only for turning and boring pulleys, but for a variety of very useful work. Among these are the following: The compound rest has an unusually long lateral feed. It may be set at any desired angle and has a power feed, and also a hand feed from either end. The and the crowning attachment brought into operation. Ordinarily the crowning of a pulley is effected by making its two parts with straight lines, leaving the angle of intersection of these lines in the middle of the face of the pulley. While this answers the purpose on ordinary pulleys, or pulleys with comparatively narrow faces, it is manifestly incorrect. In this lathe the movement of the tool is controlled by a " former " A, attached to the fixed part of the compound rest and having a curved slot of proper radius in which the friction roll of a lever B travels. This lever is pivoted to the compound rest slide and its upper end connected to the compound rest tool block by a connecting bar which thus controls the movement of the cutting- tool. Several of these grooved formers, of different radii, are furnished with the lathe for use with pulleys of different widths of face. Another feature of this lathe is the automatic feed to the tailstock spindle for boring purposes. This feed is of 13 inches travel, and readily thrown in and out by turning the knob C. In boring pulleys the proper boring bar is selected, one end placed in the taper hole in the tail spindle and secured by the clamp dog shown on the end of the spindle. The opposite end of this boring bar fits in a bushing in the head spindle, thus assuring a correct and properly aligned hole. While this work is being done the pulley may be held in a chuck, or chuck jaws attached to the face-plate, by the hub or by the rim. The pulley having been bored is pressed on an arbor and supported on centers. It is driven by two arms secured by bolts to the face-plate in the usual manner. The tail-stock is provided with the usual set-over, the same as in an ordinary engine lathe, for the purpose of turning tapers. It is provided with two sets of holding-down bolts so that the top casting with the spindle may be set over without detaching the tail-stock from the bed. By this means there is no necessity for removing the work from the lathe or blocking it up. The head spindle is driven entirely by means of the internal gear bolted to the back of the face-plate through a pinion on the cone shaft. Back gearing is provided by which, with the five-step driving cone, ten speeds may be produced. A defect in the design of this back gearing is that the gears are journaled upon a stud supported at only one end, thus permitting considerable vibration, which is liable to show by producing chattering of the tool upon the work. While the feed is entirely gear driven, provision is made for accidents to the tool by making the gear upon the end of the cone shaft with a friction device, by which it will be allowed to slip if heavy and unusual strain is brought upon it, rather than that the gear teeth be endangered. The ordinary length of the bed of this lathe is about 11 feet. It swings 60 inches over the bed and 50 inches over the carriage and will take in 50 inches between centers. Its weight is about 10,000 pounds. The head spindle is bored out so that boring bars of any length may be used. It will bore and turn pulleys up to 60 inches in diameter and 19 inches face, and a pulley up to 50 inches in diameter and 32 inches face. By throwing out the back gears a fast boring speed is produced, or the boring and turning may proceed simultanously, if the pulley is held by the arms on a proper face-plate fixture. There is no arrangement for the employment of a back tool which might do the roughing work. This fact necessarily limits needlessly the output of the lathe, as a proper rest for one or more back tools could be readily and economically provided. A pulley-turning lathe may be so designed as to become rather a pulley-turning machine than a lathe proper, and when thus specialized will usually be a more efficient machine than if designed strictly on the lines of a lathe. Such a machine is shown in Fig. 282, which is built by the Niles Tool Works, who build these machines for turning pulleys of 30, 50, and 60 inches diameter. The bed, head-stock and tail-stock are all cast in one piece, and this casting extends to the floor or foundation and provides a very rigid support for the operative mechanism of the machine. The head spindle is driven by spiral or tangent gearing, giving a very steady movement entirely devoid of the tendency to chatter as when turning a pulley or other light-rimmed wheel, when the power is by the usual spur gearing. By this device a much heavier cut, or a cut at a much coarser feed, may be successfully carried and consequently the time of performing the operation much reduced. The pulley to be turned is forced on a mandrel or arbor and held between centers in the usual way for obtaining good concentric work. As to the method of driving the pulley, there is an equaliz- ing face-plate which has arms projecting between the spokes or arms of the pulley near the rim, and which press equally upon opposite sides of the work so that there is no tendency to spring the pulley out of its proper shape, as is the case when it is held in a chuck. There are two tool-rests which operate at the same time, one being in front and provided with an angular feed for crowning the face of the pulley, and one in the rear carrying an inverted tool and provided with a hand cross feed. This lathe tool takes the roughing cut while the front tool carries the finishing cut and crowns the pulley. The angular feed with which the front tool is provided adapts it for turning bevel gears as well as pulleys. When set to make a straight cut parallel to the axis of the work it is well adapted to turning the outside of large gear blanks, balance-wheels, and similar work. While the tool at the rear of the machine is often set for a straight cut, parallel to the axis of the work, it is also provided with an adjustable slide by which it may be set at an angle for crowning the face of a pulley or for turning bevel gears and similar work. This feature is necesary in heavy work particularly, in order to leave an equal amount of metal to be cut away by the front tool during its entire cut. The driving cone is of ample diameter; it is arranged in six steps and carries a very wide belt. It runs at a proper speed for polishing pulleys, as well as for driving the machine for turning purposes, and its shaft extends to the front as an arbor or mandrel upon wiiich the pulley to be polished may be mounted as shown at A, Fig. 282. A convenient polishing rest is shown at B, which is used for this purpose. This machine is not intended for boring the pulleys, this part of the work being much more expeditiously performed on a chucking lathe or similar machine, which may be run at a much higher speed for this purpose. It frequently happens that small work and that which must be very true and correct, particularly in tool, model, and experimental work, a comparatively light bench lathe is much more convenient, useful and efficient than a floor machine of similar capacity. One or more of these lathes, of good design and construction, should form a part of the equipment of every tool room, and of any room of American made bench lathe. The bed of the lathe is 32 inches long and has a T-groove planed the entire length of the back side. A bed without this groove will be furnished, if desired, at a lower price, but such a bed will not take all the attachments that have been designed for it. The amount of metal in the bed is distributed so as to give great stability and rigidity while at the same time pleasing outlines are presented. These qualities apply equally to other parts of the lathe, beauty of design being one of its features. Waltham Watch Tool Company. The head-stock will swing 8 inches. It has a hardened steel spindle and bearings, carefully ground and run together. It is very smooth running and the finest work can be done with it. The pulley has three steps of 3, 4, and 5 inches in diameter and will take a belt 1J inches wide. The larger flange has three circles of index holes, the numbers being 48, 60 and 100. The spindle is adapted to take split chucks of the most approved pattern, which will take wire up to f inch in diameter through its entire length. The spindle of the tail-stock passes entirely through the casting, so that whatever its position it always has its full bearing (6f inches). It is graduated to tenths of an inch, while the gradations on the hand wheel read to 1-200 inch. The front side of the casting is cut away to give more room for the slide-rest. By this means the lathe can be used closer to the center than would other- the necessary stiffness. The base of the slide-rest rests directly upon the bed of the lathe, and its squaring device has a bearing on the front of the bed, below the lowest part of the head-stock and tail-stock. This gives the opportunity to make a long squaring device, thus insuring greater accuracy, and also to have the bearing where there is less liability of trouble from chips, dirt, etc. The builders also make a swivel squaring device by means of which angles can be turned or ground with the cross slide, thus enabling one to make two angles with one setting of the slide-rest. This is a valuable feature in making special cutters or mills, or in grinding spindles and bearings having two angles. The feed screws have hardened bearings, and are provided with indices that are graduated to read to 1-1000 inch on the swivel screw, and to 1-2000 inch on the cross-slide screw, the latter division being adapted so that the movement of one graduation on the index will make a difference of 1-1000 inch in the diameter of cylindrical work which is being turned or ground. The tool-slide is made flat on top to take various attachments, and has two T-grooves for the tool-post. Ordinary lathe tools are used. The slides are carefully scraped together and the whole sliderest is neatly ornamented. For holes and for light outside grinding there is an inside grinder that is arranged so that the lap can be swung away from the hole, for testing the size, and then returned instantly to its original position. The outside grinder for general work is clamped directly upon the tool-slide and has a vertical screw adjustment. It is arranged so that an emery wheel can be used on either end, and there is a taper hole in the front of the spindle to take arbors for small laps. Two methods of thread cutting are provided for. The first is on the Fox lathe principle and is attached to the T-groove on the back of the bed. Any even multiple of the lead screw thread up to ten times can be cut, and with a few extra lead screws all ordinary threads can be cut. This method of thread cutting is the most rapid, but under conditions in which a great variety of threads must be cut some machinists will prefer to use the slide-rest. By centimeter can be cut. There is also a special milling attachment, which is a stand consisting of a base made to take the regular head-stock, and is provided with a slide which takes the regular slide-rest. The vertical slide has both a screw and lever feed, so arranged that the change from one to the other can be made instantly. A vise for plain milling, or an indexing head for gear cutting and cutter making, can be attached to the tool-slide of the slide-rest. This combination makes a practical bench milling machine upon which a great variety of work can be done. While the descriptions of engine lathes are confined to the lathe proper, leaving the subject of their attachments and accessories to be treated in another chapter, it seems advisable to include in the above description the various attachments of this bench lathe, as they are essentially different from those used upon or in connection with an engine lathe, and for different purposes. In addition to the attachments above described it is frequently the case that others for special work are frequently devised and added to the bench lathe equipment, making it a very useful machine and capable of performing a great many different operations, among them many which cannot be performed on the regular engine lathe without the aid of expensive attachments and fixtures. These qualities make it one of the most useful machines in the shop, especially where small experimental work and fine tool making, jigs, and fixtures are to be produced. A plain 10-inch swing wood-turning lathe for light manufacturing work or for pattern work is shown in Fig. 284, which possesses some peculiar features worthy of attention. The lathe is built by the F. E. Reed Company. One of the special features of this lathe is the manner of constructing the head-stock, a vertical section of which is given in Fig. 285. The spindle has a single bearing in the head-stock, which extends over a large proportion of its length, the face-plate being attached to the front end as usual, and the three-step cone pulley attached at the opposite end, fitting upon the spindle for a distance about equal to one of its steps and carried by a flanged collar which There is a ^g-inch hole through the spindle, whose bearing in the head is lysg inches diameter and 7J inches long, while there is also an outer bearing, formed by the small end of the cone running on the outside of the head-stock, 2116- inches diameter and 3f inches long, giving 50 square inches of wearing surface in the head-stock, which is at least three times more than is obtained in the headstock of an ordinary wood-turning lathe of this swing. The head spindle is a crucible steel forging, and runs in compressed genuine babbitt metal bearings, special care being used to make the inner and the outer bearings truly cylindrical and concentric with each other. "We have made and sold over six hundred of these lathes during the last eight years. For over six years we have had one of them in constant use in our works as a polishing lathe. This is very severe usage for a lathe, but during all this time it has required absolutely no repairs, and no special attention beyond seeing that it was kept properly oiled with a good quality of lubricating oil. We have a large number of most excellent testimonials from schools that have used these wood lathes for a number of years." The countershaft is of very simple construction and of similar design to the head-stock. In place of the usual tight and loose pulley with the belt operated by a shipper rod and lever, the belt fork is handled by a vertical rod, the lower end of which hangs in a position convenient to the operator, who has only to give it a turn to the right or left by means of a short handle to start and stop the lathe. The V's in the bed are inverted, or planed out, and the head and tail stocks are fitted into them, instead of upon them, which is the usual way. This allows a perfectly free and level surface across the top of bed and shelf on back side, without any obstruction, besides protecting the V's from being jammed. The upper angle of V is rounded where it meets the surface of the bed, which also prevents jamming or injury of the bed or V at this place. The T-rests, instead of being the usual form, are concaved, with a projecting lip on the bottom which serves as a finger gage for the operator while using the turning tool. The T-rest holder is secured to the bed by a clamping device that is neat, strong, and quickly operated. There is a shelf on the back side of the lathe, parallel with the top of the bed, and of the same height; another shelf is also furnished underneath the bed, as shown in the engraving. A hook or holder, with proper support for the same is shown. This is for holding a blue print, or sample of the work, before the operator, and can be raised or lowered. The form of the lathe bed in connection with the extra speed of the legs, and the manner of attaching the lower shelf, all combine to insure steadiness of the lathe when run at the high speed for which it is designed; and each lathe is run five hours at 2,600 revolutions per minute before leaving the works, to see that it is in every respect right. Importance of the turret lathe. Its sphere of usefulness. Classification of turret lathes. Special turret lathes. The monitor lathes. The Jones & Lamson flat turret lathe. Its general design and construction. Its special features. Its tools. The Warner & Swasey 24-inch swing universal turret lathe. Ganeral description. Its capacity. Taper turning attachment. Its speeds. The Bullard Machine Tool Company's 26inch swing complete turret lathe. Its massive form and its general design and construction. Lubrication of tools. The countershaft. The Pratt & Whitney 3 by 36 turret lathe. Its special features. Its general desing. Its capacity. Special chuck construction and operation. The Gisholt turret lathe. Its massive design and construction. Its large capacity. Its general and special features. The Pond rigid turret lathe. Its heavy and symmetrical design. Detailed description. Its operation. General dimensions. WHILE the regular engine lathe is in almost universal use wherever machine work is done, and while it is the one indispensable tool in every machine shop, the modifications of it in the various forms of a turret lathe are becoming second only in the importance and the range of its work. So great has been the advance in this respect during recent years that nearly all machine shops, even small jobbing shops, are not considered as possessing a passably modern equipment without one or more turret lathes. Formerly it was not thought worth while to " set up" a job on a turret lathe unless there were fifty or more pieces of the same kind to be machined. It is now a common occurrence to use the turret lathe when only half a dozen pieces of a kind are to be made. The reasons for this are that formerly special tools had to be made for many of the jobs attempted, whereas now we have a great many regular tools furnished with the turret lathe that are of such form and construction as to be available for nearly all the ordinary turret lathe jobs, while the addition of an extra tool now and then for special work, or a special form, will adopt the turret lathe for a very large variety of work, which may thus be performed with a great degree of accuracy, with a very good finish and in a very economical manner. Where large numbers of pieces of the same kind are to be made, it is usually the practice to make special tools whenever better work or a larger output can be thereby secured. This will be largely a matter of practical judgment of the man in charge of the work. We may divide the turret lathe proper, and the engine lathes when used as turret lathes by the addition of a turret, into five classes, according to their design and methods of operation, namely : pound rest. Second, the engine lathe serving as a turret lathe by mounting a hand-revolved turret upon the bed by means of a shoe or saddle which supports the turret slide. Fourth, a turret lathe similar to the last and sometimes called a " semi-automatic turret lathe," in which there is a power feed on the cut and the turret is revolved automatically at the end of the stroke. inverted tool at the back. Various examples of these different classes will be illustrated and described in the following pages, giving the designs built by several of the prominent manufacturers of this type of machines. There are, of course, special machines of this general type of lathes built for special purposes. There are modifications of the general class, into the details of which it is impossible to go in these subject of lathes. There is one type that deserves special attention on account of its valuable service on small work, and that has been known in the shop for many years as a "monitor" lathe, from the fact, no doubt, of its resemblance to the turret of a monitor. The slide upon which the turret is pivoted is run forward and back by a lever which makes it very rapid in operation. It is usually built for small work only. The Jones & Lamson flat turret lathe is now so well known that an extended description of it seems hardly necessary, and yet its importance in the manufacturing world of to-day, and its many points of real mechanical interest and importance, demand more than a passing notice. A front view of one of these machines is given in Fig. 286, this particular machine being 3 x 36-inch size, that is, it will work up a 3-inch bar and the turret has a run of 36 inches on the bed. As will be seen the bed is supported by strong and well designed legs in a pan nearly the full size of the machine. The head-stock and its gearing is covered by a protecting case which moves with it. One of the peculiar features of the machine being the sliding head which has a transverse movement for the purpose of increasingits effective working capacity. The turret is mounted upon a saddle fitted to broad V's upon which it has a long bearing, insuring accurate results. The connections of the turret to the carriage, and the carriage to the lathe bed, are the most direct and rigid, affording absolute control of the cutting-tools. The turret is accurately surfaced to its seat on the carriage by scraping, and securely held down on that seat by an annular gib. In the same manner the carriage is fitted to the V's of the bed; the gibs passing under the outside edge of the bed. The breadth of this bridge across from V to V makes an unyielding mass to which the tools can be affixed. The indexing mechanism of the turret is of the greatest importance, and in this particular point the flat turret lathe seems to have an exceptional advantage. Its index pin is located directly under the working tool, and so close to it that there can be no lost motion between the tool and the locking pin. The turret is turned automatically to each position the instant the^tool clears the work on its backward travel, and it is so arranged that by raising and The worm is held into its wheel by a latch which is disengaged by the feed stops. There are six feed stops, one for each position of the turret, and they are independently adjustable. This feature of an independent stop for each tool will be appreciated by the users of the other turret lathes, some of which have only one stop for all turret tools. These feed stops are notched flat bars placed side by side in the top of the bed. They also serve as a positive stop. The head-stock is of such great importance that weakness here would mean a weak link in the chain. Greatest care has been exercised to make the head-stock equal in stiffness to the turret. The spindle is ground to size, and its phosphor-bronze bearings are scraped to give a perfect contact. A 2J-inch hole extends from end to end, through which the bars of stock pass. lower half. The cone and large gear are loose on the spindle and connected at will by friction clutches. The large gear is covered with a hood which protects it from chips and dirt, ensuring smooth running. The back gear is placed below the cone in the head, and a triple back gear, when required, is placed beneath the regular back gear. The regular back gear gives a 4 to 1 proportion, and the triple gear makes a 16 to 1 speed. The triple gear is required for all standard screw threads above If inches in diameter, and in chucking work of large diameter. The die carriage carries a die of any kind, and a pointer for shaping the end of a shaft or bolt. This carriage is mounted on a sliding bar and arranged to swing into wrorking position. It is provided with lugs which take bearing on the top of the crossslide, which tool must be in operative position when the die carriage is used. The pointing tool may be used as a turner for reducing the stock. The head receives its power through a triple friction countershaft of unusual proportions and running speed. The three friction pulleys are 12 inches in diameter by 4 inches face; two run 300 revolutions per minute, and the remaining, or middle, pulley runs 150 revolutions per minute. These pulleys have extra long hubs that extend an equal distance each side of the "pull of the belt" (each side of the rim), and perfectly distribute that strain over its entire bearing on the shaft. The shipper rod is so connected that it will act on any one of the three clutches at the will of the operator. The machine tools built by Warner & Swasey are known wherever American machines are used as being of good design, good materials, and good workmanship. In fact, some of the finest machine work turned out in this country comes from their shop. Their turret lathes are no exception to this rule, and in Fig. 288 is shown their 24-inch swing universal turret lathe, which is a good example of a lathe of this type, adapted to a large variety of work such as iron and brass valves, from 3 to 6 inches, gears, pulleys, bearings, machine parts of circular contour, and general chucking work requiring drilling, reaming, and facing. The bed is 8 feet 7 inches long, and is deep and heavily ribbed as it should be in a lathe of this kind. The head-stock is cast in one piece with the bed, rendering it strong and rigid against the weight of the work and the torsional strain of the machining operations. The spindle cone is of three steps, the largest of which is 16 inches in diameter and adapted for a 4-inch belt. The spindle has a 2J-inch hole all the way through. From the end of the spindle nose to the face of the turret is 36 inches when at its extreme position. a longitudinal travel of 32 inches and a cross travel of 12 inches. Two sets of independent adjustable stops are provided for each face of the turret, one operating with the longitudinal and the other with the cross travel of the carriage. When the general work which the lathe is expected to do renders these stops superfluous, they may be omitted from the regular equipment. The geared feeds, both for the longitudinal and the cross cuts, give six changes, any one of which is made instantly available by moving a lever. These feeds are so designed that they will give respectively 4, 7, 12, 16, 28, and 48 to the inch for every revolution of the main spindle; that is, the spindle will make these various number of revolutions while the feeds advance 1 inch. The lead screw is provided with the proper gears for cutting 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}, 12, and 14 threads per inch. Finer threads than these are not likely to be required on a lathe of the capacity of this one. 3 inches per foot, which is furnished only when specially required. The machine is driven from a triple friction countershaft which has 16-inch pulleys adapted for a 4}-inch belt. One of these pulleys runs at a speed of 100 revolutions per minute and the other at 140, which gives twelve spindle speeds ranging from 53 to 264 per minute without the back gears, and from 7 to 30 revolutions per minute when the back gears are in use. A third pulley is designed to run the spindle backwards. adapted to a large class of products. The Bullard Machine Tool Company enjoy a reputation for turning out first-class machines. This applies equally to the design, the material, and the workmanship. lathes, or as might be more comprehensively termed, turret machines The machine is of massive design, the bed deep and strongly braced. It is provided with heavy top members or tracks, carrying broad V's, and surrounded by a proper pan for catching and carry- ing off whatever lubricating material is used. The bed is well supported at the head end by a broad cabinet, made long enough to furnish a solid support under the front box of the main spindle. At the rear end, where much less support is required, a leg is deemed sufficient. The head-stock is of ample length to furnish large housings for the main spindle boxes, as well as sufficient space for a three-step cone of liberal dimensions and the necessary back gears, clutches, etc. The largest section of the cone is 16 inches in diameter and adapted for a 4\|-mch belt. The spindle is bored out to 3\| inches and is fitted with a chuck of suitable design for taking hexagonal, square, or round bars. The spindle is driven by triple gearing and is fitted with a patented friction clutch for instantly changing from belt speeds to either set of gears without stopping. The change to back gears is made by moving the clutch lever, and to the triple gears by means of the lever shown on the back of the front spindle bearing, thus obtaining three speeds from the cone, three through the double train of gears, and three through the triple train of gears, making nine spindle speeds in all. , The carriage is designed to be heavy and strong and has a long bearing upon the bed, to which it is securely gibbed. It is provided with a taper attachment, reversible cross and lateral feeds, which are driven by gearing from a splined lead screw, the thread of which is used only for thread cutting, thus insuring accurate work of this kind. At the front of the bed and directly below the large step of the spindle cone are seen the carriage stops, which are adjustable in a group upon the bed, and independently as the work may require. The cross-slide is unusually wide and is operated by a screw and a three-ball crank. There are three tool-posts so that forming cuts may be made as well as the usual cutting-off operation performed. The turret is hexagonal in form and 14 inches across the flat surfaces. The tool holes are 3J inches diameter and the center stud is drilled with a hole of the same diameter so as to allow a bar to pass entirely through. The tool faces are also drilled with four holes each for use in bolting on large tool-holders. The turret is provided with an automatic feed and trip, and with a patented device for unlocking and revolving it at any point between 8 and 22 inches of its run. It is pivoted upon a long top slide provided with stops at the rear end and may be operated by the automatic feed or by the capstan levers in the usual manner. The top slide is well supported by a long and broad bottom slide or base, firmly clamped at any point on the bed, and moved along the bed by a rack and pinion device. The lubrication of tools is amply provided for, the lubricant being pumped from a tank on the floor and up through two pipes properly jointed so as to deliver two streams of lubricating compound at a time at the points desired. Situated over this tank and beneath the pan surrounding the bed, is a secondary pan supported on wheels so as to be readily removable when it is desired to clean it out. Into each end of this, oil and chips drip from the two lips seen at the right and left. This feature " ^^^s\ will be duly appreciated by I . the operator, who has been /f § accustomed to clean out the / & pans of the older style ma- Fig. 290 and a plan of it is given in Fig. 291. As may be assumed from its capacity it is a very rigid machine in which the bed, head-stock and pan are cast in one piece. On account of the great quantity of oil that is necessary to use upon it when machining bar stock, the bed is set in a pan of ample proportions and well supported on heavy legs, those under the head-stock One of the new features of the machine is the chuck, which is arranged to handle bar stock considerably above or below size with the same gripping force as if the bar were true to size. This is a feature of much value in machining the larger sizes of rough stock in which there is usually considerable variation in the diameter even at different points along the same bar, as well as the frequent occurrance of slight bends in the bar that render it difficult to handle in the ordinary turret lathe chuck. This machine is regularly driven by a three-step cone pulley adapted for broad, double belts. This cone pulley, in conjunction with the double friction back gears and a three-speed countershaft of improved design, gives to the main spindle twenty-seven speeds, or nine for each step of the cone. These nine different speeds with an open belt range from 78 to 550 revolutions per minute, and the eighteen back gear speeds run from O^Q- to 182 revolutions per minute. This great range of speed adapts the machine to handling all work, not only from 3 inches in diameter down, but all classes of materials as well, so that it does its work under a very large range of conditions and circumstances. The turret slide has power feed for turning lengths up to 36 inches, and the driving device for the feed mechanism for the turret and cross-slides is by means of a silent chain which is driven from a sprocket wheel on the spindle, from whence it leads down to a gear box containing the variable speed gears for giving the different rates of feed. The shaft for operating the turret and cross-slide located at the rear of the bed, and the gear box mechanism is operated by the two short levers in front of the head-stock as seen in Fig. 290, and by which four rates of feed in either direction are obtained for either the turret slide or the cross-slide. The turret feeds range from .007 to 0.23 inches and those of the cross-slide from .0014 to .004 inches per revolution of the main spindle. There are dovetailed upper and lower edges on the hexagonal turret faces, to wrhich tools may be rigidly clamped, and each tool is provided with an independent stop which is carried in an adjustable bracket fixed to the front of the bed. By referring to the plan view of the machine in Fig. 292, at X, it will be seen that there are six stops placed side by side in the bracket above referred to. Each one of these, when adjusted, is held by an independent screw. As the turret is rotated a cam at the bottom operates an arm carried on a rock-shaft at the side of the turret slide and swings it into line with the proper stop in the bracket. This rocker arm, or turret stop, is always rigidly supported, as in all positions the rear face rests against a machined surface on the slide. The cross-slide carries two toolposts of good design for holding tools rigidly, and may be adjusted at any point along the bed that the work requires by a hand wheel at the front end of the head-stock The peculiar construction of the chuck referred to above is worthy of special attention and may be understood by reference to the sectional engravings and the following description of its mechan- screwing on over it. G is the chuck jaws and H the closing collar. This collar as well as the jaws of the chuck and the wearing surfaces of the cap are hardened and ground, and the rear end of the latter is made a sliding fit in the spindle bore, while its front end is ground to a sliding fit in FIG. 293. — Chuck Construction of the Turret Lathe. keep them in contact with the cap when released by the closer. The jaws for each nominal size of stock are adapted to hold bars 332 inch over size, or ^ mcn under size, and anywhere within this range they maintain a parallel grip on the bar. This is due to the fact that the contact between jaws and closer is always a line contact along the middle of each jaw, the surface at either side of this line being relieved so as always to clear the conical seat in the closer. To give the jaws a uniform gripping pressure upon the work, regardless of the variation in size from standard, provision is made for first bringing them into contact with the bar by operating a lever, after which they are closed tight by means of a second lever, both levers being mounted at the front of the head and about a common axis, as shown in Fig. 290. Referring again to Figs. 292 and 294 it will be seen that the rear end of the spindle carries two sliding rings actuated by independent yoked levers; these latter are connected by links with the operating levers just mentioned. The ring C, Fig. 293, is fitted with a pair of racks each of which engages with a -spiral pinion formed at the center of a right and left-hand screw; the front ends of the screws fit holes tapped in collar A, which is secured to the spindle, while the rear ends are screwed into the sleeve B which carries the chuck-closing fingers J, whose heels are always in contact with the lugs of the chuck-closing tube K, the rollers at the outer ends resting against the shoes carried in the ring I. The yoked lever N, operated through the link 0 by the inner of the two vertical levers in front of the head, is connected also by the slotted link L with the stock-feed mechanism at the rear. When the chuck is opened and the stock stop swung down from the head, the inner lever is thrown over, forcing the link L toward the rear and clutching the gear M to the feed screw, which is then driven from the spindle in the right direction to draw the bar forward against the stock. When the bar is in contact with the stop the clutch throws to the middle position as shown, stopping the screw; the lever is then thrown in the opposite direction, sliding the ring C on its bearing, and by means of the racks, spiral gears and right and left-hand screws the sleeve B, with fingers J and tube K, is drawn forward, forcing the chuck jaws into contact with the bar. The outer lever is then operated to push back the ring I and close the chuck down hard upon the work. be noticed that no matter what the position of the closing tube K may be when the jaws are in contact with the stock, the pressure exerted through the fingers J and the sliding ring I is always uniform and effective. The upright at the outer end of the stock-feeding apparatus carries an adjustable rotating support for the bar stock, and the traversing bracket R actuated by the screw is adapted to receive various sizes of bushings corresponding to the collars secured to the stock. When the feed bracket has reached its extreme forward position it is run back by moving to the left the short lever shown in Fig. 290, which clutches the reversing gear M to the screw. The clutch between gears M and S is normally held in mid or inoperative position by the spring plungers at the lower end of the arm P. The gears are driven continuously (so long as the spindle is running ahead), by the double gear Q on the sleeve above ; the clutch connecting the driving gear to the spindle end is so formed, however, as to be inoperative if the spindle is reversed, thus making it impossible to engage the feed accidentally before the spindle is again started ahead. Taken altogether this mechanism represents the latest and best development in its line for the purposes intended, and is in keeping with the usual practice of this company of careful designing and good, practical construction. The Gisholt turret lathe occupies, a somewhat different field than that usually covered by the other manufacturers of turret machinery, in that the machines are much larger and heavier and of much greater capacity, handling very large and heavy work. While there are none of the other builders who make a turret lathe of much over 30-inch swing, the Gisholt lathe is built as large as 41 J inches, this largest size weighing about eight tons, while there are very few of those of other builders weighing more than one half as much. Figure 295 shows this machine swinging 41 J inches over the bed. As will be seen, all the parts are very massive and calculated to withstand the heaviest strains to which a machine of this type could possibly be subjected. weight should always be placed), and has the head-stock cast in one piece with it so. that the greatest amount of rigidity maybe preserved. The housings carrying the boxes for the main spindle runs in reamed and scraped bronze boxes. The turret is hexagonal and very large, in order that heavy tools may be rigidly secured to it. It slides directly on the ways of the machine and hence has the full traverse of the bed. This permits of the use of long boring bars, the outer ends of which may be supported in a bushing in the chuck. The carriage is provided with a turret tool-post carrying four tools, any one of which may be instantly brought into position for cutting. These tools are independently adjustable as to height. The cross feed has micrometer index reading 1-1000 of an inch. Power cross feed and taper attachments are provided if desired. For each tool in the tool-post and for each face of the turret feed and dead stops, independently adjustable, are provided, by means of which the feed may be thrown out automatically at any desired point. The feed works are entirely novel and permit of four changes of feed being instantly obtained, either from the end of the machine or from the turret slide. The feed is also instantly reversible. The four tools which may be carried in the carriage tool-holder are held by means of a large square plate, forced down by a heavy screw in its center. The tools are placed under the edges and parallel to them and brought into active position by the entire tool-holder top, swiveling turret-like upon a central pivot, when raised to the proper position for that purpose. Stops, independently adjustable, are arranged for each of these tools, both for lateral and cross feeds. Turret stops are arranged at the rear of the machine and may be severally brought into working position by rotating the cylindrical carrier. They are, of course, independently adjustable. In Fig. 296 is given a view of the top of the machine, which will serve to show the various operative parts of the turret and its stops, the revolving tool-holder on the carriage, and the taper attachment, much more clearly than is shown in the front view in Fig. 295, and on a much larger scale. This description might be much more elaborate but the machine is quite well known among practical shop men and those having any special connection with this branch of machine business, and further details do not seem necessary. Pond tools are considered good tools and are usually designed heavy enough and strong enough to stand the strain of any work that the machine may be called upon to do. While this remark applies to a great extent to all Pond tools, it is particularly applicable to the Pond rigid turret lathe, represented in Fig. 297, which well illustrates its massive construction. This is particularly true of the tool carriage and of the saddle which supports the turret, as well as the bed, which has the supporting legs cast with it. Its design is such as to furnish the best resistance and support for both the strain of weight and of torsion. work, and also allows the carriage to be run behind the chuck so that the turret may be brought up close to the chuck. Short, rigid tools with practically no overhang and short boring bars can therefore be used. In no other machine is this feature available. The design of the turret provides for six faces, three of which are of extra width, permitting the heaviest facing, multiple-turning, and forming tools to be rigidly attached. a conical hole shown at the front of the turret in Fig. 297, the very wide face, provided with a groove across the center into which a rib on the tool base fits, and the two T-slots for the four bolts securing it to the turret, are manifestly very valuable in holding the tool stiff and rigid, and doubtless suggested the name of " rigid turret," as there is every reason to assume such condition from the excellent design. is arranged with hand wheel for operation by hand if desired. Separate feed-screws are provided for turret and carriage, giving instantaneously six different feeds with same change-gears. Any feed available may be used on both the turret and cross carriages at the same time. The spindle bearings are of very large diameter and the hole in the spindle is 4J inches in diameter, counterbored to 5J inches in diameter, 18 inches in depth, so as to permit boring bars with both roughing and finishing cutters to be used; the roughing cutter being inside the spindle when the finishing cutter is at work. Headstock has self-oiling bronze bearings and a two-step cone, providing for a very wide belt. A complete line of standard tools is furnished with these machines for boring, facing, and turning. The firm has a department solely for this purpose, making a specialty of designing and furnishing box tools and dies for any work that can be handled on a turret lathe, and adapted to this machine and other machines of its class. It will be noticed by reference to Fig. 297 that the changes of speed in the head-stock are effected by a single lever; the changes of feed by three levers and two index arms giving a great variety of feeds and adapting the machine to work on all kinds of metals and all diameters and forms having a circular cross section. The general dimensions and capacities of the machine are as follows: swing over the V's, 28 inches; over the cross-slide, 24 J inches; hole in spindle, 4J and counterbored to 5J inches for a depth of 18 inches from the front of the spindle. This machine will take in a bar 4J inches in diameter. The spindle bearings are: front bearing, 8x9 inches; rear bearing, 5J x 6 inches. All threads from \ to 64 per inch can be cut. The spindle speeds are twenty in number, and from 1J to 182 revolutions per minute in regular geometrical progression. The gearing ratios for the head-stock are respectively 3i to 1, 8} to 1, 22 to 1, and 57 to 1. The tool-holding holes in the turret are 3 inches in diameter. The distance from face of chuck to face of turret when at its extreme position is 5 feet 4 inches. The travel of the turret is 5 feet and its speed is 25 feet per minute. The cross travel of the carriage is 36 inches, which is very liberal. The turret tool-post on the carriage has four tool positions. The length of the machine over all is 15 feet 11 J inches, and its width 5 feet 3 inches. The machine complete weighs 12,500 pounds, a very liberal weight for a machine of the capacity of this one. The R. K. Le Blond triple-geared turret lathe. General description. The Springfield Machine Tool Company's 24-inch engine lathe with a turret on the bed. Its special features. Its general dimensions. Its design and capacity. Turret lathe for brass work built by the Dreses Machine Tool Company. Its general description. .Special features and construction. A combination turret lathe built by the R. K. Le Blond Machine Tool Company. A useful machine with many good features. A 15-inch swing brass forming lathe built by the Dreses Machine Tool Company. Its distinguishing features. Le Blond Machine Tool Company's plain turret lathe. Plainness and simplicity its strongest points. General dimensions. The Springfield Machine Tool Company's hand turret lathe. A modification of their 18-inch swing engine lathe. The Pratt & Whitney monitor lathe or turret-head chucking lathe. Its general features and construction. THE R. K. Le Blond Machine Tool Company build a line of well designed and substantial turret lathes, a representative of which is shown in Fig. 300, which is of a 31-inch swing, triple-geared machine with double back gears and a friction device, and is driven from a triple-speeded friction countershaft, by means of which fifteen speeds may be had without changing a belt, thus adapting it to a great range of work requiring different speeds in order to do the work with the maximum degree of efficiency. Special attention has evidently been given to the design, so as to have it very strong and rigid in all parts which support the working members so as to afford an ample protection against vibrations when taking heavy cuts. The head-stock is unusually large and massive. It is back geared 55 to 1, so that it has enormous power for forming and facing cuts. The turret has a double bearing on the slide, making it perfectly rigid. It is locked with their patented locking pin, having a bearing on both sides of the locking ring. All wear can be taken up between the turret and stem by means of a taper bushing. The carriage is very heavy, gibbed both back and front, and the rack pinion is supported on both sides of the rack. This lathe is especially fitted for box or forming tools, and will work a nest of roughing tools to good advantage. Changes of feed can be had instantly by the use of the lever shown on the bed ; and, with half nuts in the apron, and any tapping work can be done with positive lead from the screw. A specially strong chuck is furnished having, in addition to the hardened jaws, a set of soft ones to be used for the second operation, so as to secure perfectly concentric work, which is frequently difficult, particularly when the limits of measurement and the exact running of the work are important conditions. It will be noticed that the feed gears are of broad face and well adapted to heavy work and that the lathe carries a very heavy and strong chuck, which is all-important when heavy cuts are to be made as well as when the work itself consists of large and heavy pieces. It is particularly well adapted to machining forging up to the limits of its swing and of rough outline, which usually prove very trying to any lathe containing any inherent weakness of construction. As an example of the second class, the 24-inch swing engine lathe, built by the Springfield Machine Tool Company, is shown in Fig. 301. In this case it will be seen that the carriage remains on the lathe as usual and may be used in conjunction with the turret While turrets thus applied to an engine lathe are usually equipped for hand feed only, there is a device furnished with them by some builders, by the use of which a power feed is provided. This is the case with the lathe here shown. The turret slide is supplied with variable power feed and automatic stop, which in no manner interferes with the usual engine lathe feeds and screw-cutting mechanism, each being entirely independent of the other, and can be used separately or collectively as the work demands. Therefore, should conditions exist where the same lathe is to be used for turning work between centers as well as when held in chuck or face-plate, the tail-stock can be fur- revolve automatically or by hand to suit the user. The details are constructed with great care. The index ring is of large diameter and made of tool steel. The locking plunger is also made of tool steel slides between large bearings, with provision for adjustment to take up wear. Although these turrets are of massive proportions, and possess rigidity to an unusual degree, they are very conveniently handled, an important factor towards the ends sought. Some of the dimensions of these turrets are as follows: width across flats, 12 J inches; diameter of holes for holding tools, 2J inches; length of the top slide upon which the turret is pivoted, 46 inches; width of the bearing surface, 11 inches; length of bottom slide, or saddle, 30 inches; width of bottom slide, 11 inches; extreme distance between lathe spindle and turret face on a lathe with a 10-foot bed, 42 inches; weight of turret, 1,200 pounds. These figures will give a good idea of the substantial design of this device, which was evidently intended for heavy work and hard usage. It is very important that all parts of a turret, of whatever kind of type and for whatever purpose, should be strong, rigid, and well fitted. If not of sufficient weight to give it the necessary strength it will fail when put to the actual test of hard work. If not of sufficient rigidity the tools will " chatter" and either seriously mar or spoil the work. If all the parts are not well fitted the tools will not "line up" with the head-stock spindle, and as a consequence true work cannot be done in the machine. It may be stated as a practical fact that in turrets built by the best manufacturers it is not usual to find the entire six holes lining up perfectly with the headstock spindle. While the present machines of this type are far ahead of those built a few years ago, in these respects, the practical shop man will be fairly well satisfied with a turret if he finds but two of the holes "dead true," two more near enough true for the usual class of work, and the remaining two considerably out of true. And this will generally be the case even though the "finish boring" of these holes is done with a tool carried by the head-stock spindle in the lathe that the turret is fitted up for. To the young machinist this may seem strange, but it is nevertheless true, and true of probably a large majority of turret machines of the present day. A very complete turret lathe for working brass and other similar metals is built by the Dreses Machine Tool Company. It is shown in Fig. 302, and is known as a 15-inch friction back geared brass turret lathe, and is provided with a special chuck, cutting-off slide and a slide-rest. The bed is of the box pattern with a dovetail top, which provides the best means for keeping alignment and for quick and firm gripping of the turret and cut-off rest. It is supported on the three- point principle to avoid springing and getting out of alignment through careless setting up or settling of floors and foundations. The top is provided with holes for the oil and chips to drop through. The head-stock on the smaller machines is cast in one piece with the bed. In this machine it is attached to the bed by gibs and bolts. The housings are provided for either phosphor bronze or babbitt metal bearings. The friction clutch back gear is of a new design, very simple in operation and positive in action. The wear is taken up by a screw driver from the outside, without even removing the cover. The spindle is of special hammered crucible steel. The bearings are ground and run in phosphor bronze boxes with special means for oiling and taking up the wear. The turret revolves automatically on a ground steel stem with special device for taking up the wear. It is provided with a setover device. The top slide can be operated either by the crank and screw shown at the rear end, or by the capstan levers in the usual manner. One of the capstan handles is provided with a short handle at right angles with it for convenience in quick operations. when quick operations are constantly required. The longitudinal and cross-feed stop screws are located in easily accessible places. The base slide is clamped to the bed by a single handle and the operation of clamping is by a single motion. The turret locking bolt withdraws by the return stroke of the top slide, so that the operator needs only to revolve the turret. This is equally effective as a full automatic turret, but less costly and complicated. The index ring and key are of hardened steel and ground. The square locking bolt is provided with an adjustable taper gib, and a coil spring for actuating it. The cutting-off slide is extra heavy and is provided with an independent stop for both front and rear tools. It has both a screw and crank wheel feed and a lever feed, either of which may be used as occasion may require. The slide-rest is of much better design and construction than is common in similar work and is a very useful addition to the lathe, increasing its capacity in handling work of complicated nature, as by its use another series of cuts may be made without removing the work from the chuck. The special chuck is so arranged that the work may be gripped or released while the machine is running, thus avoiding the necessity of stopping to feed the bar in every time a piece of work is cut from the bar. well and efficiently. Taken altogether the lathe is well designed and has been provided with many very useful devices that no doubt prove convenient and effective in practical work. The special forming slide located next to the turret may, of course, be located at any point in relation to the usual cutting-off slide or the slide-rest that may be desired in order to properly perform the work in hand. Either of these adjuncts may be removed when not required for the piece to be machined, or all may be used upon a long or complicated job when needed. dages are the same as those shown in Fig. 300, and the bed and cabinets supporting it are the same. The turret and carriage arrangements, however, are quite different and adapted to a much larger range of work. The carriage is fitted with a turret tool-post which will carry four tools under the massive top plate shown, and which are securely fastened by the set-screws through it, thus materially increasing its capacity for different cuts on the same piece of work. A binding lever on its top secures the tool clamp in any desired position. The turret is very heavy and well supported by the turret slide, upon which it is pivoted, and a long base slide or saddle. It is run forward and back by a capstan or pilot wheel with long levers giving ample hand power. The turret can be connected with the carriage so as to be used for thread cutting and for tapping, as it thus connects positively with the lead screw by way of the apron. This feature is valuable in many respects. In addition to the above convenience it has its own automatic feed, which has an unusually long run. As the turret has six large flat faces, each tapped with four holes in addition to the central hole for holding tools, it is well adapted for carrying large box tools, facing tools, or farming tools for special work. It is altogether an exceedingly useful machine, combining many practical features, great weight, strength and rigidity, and consequently capable of performing very heavy work. The turret-forming lathe is a machine that is very useful on a variety of work in which complicated outlines occur in a piece of circular cross section, and in which a large number of pieces of exactly the same design and contour are required. In handling brass work of this variety, what is known as the forming slide, verti- cal forming rest, etc., is found very useful, doing the work upon soft metals that the very heavy rest with its horizontal forming tools do for the harder metals, as iron and steel. The distinguishing feature of the machine is the forming slide, which consists of a base securely clamped to the bed and supporting a horizontal slide fitted in a dovetail and moved by a feed or adjusting screw. Upon the top of this slide is secured an upright having formed upon it a dovetail, and being adapted to swivel within a small arc. Upon the dovetail on this upright is fitted another slide which is moved by means of a rack, pinion, and lever. This latter carries the forming tool-holder, which is also capable of being tilted slightly and properly clamped when it is adjusted to the right position. In front of the slide to which the upright is attached is placed an auxiliary small slide, provided with a tool-post and operated by the handle shown at the left. This slide is for use in cuttingoff and for other final operations. clamped or released instantly. An automatic chuck is provided in which work may be gripped and released without stopping the machine. This is very convenient when bar stock is used. spindle speeds are obtained. The plan of adding the forming slide feature to the turret lathe is of much interest in manufacture, since it increases very much the range of the work for which the machine may be used, and with this forming slide so designed as to make it compound in its action, and including also the cutting-off tool-post, its usefulness is still further increased, making the machine as a whole a valuable one on all light machine operations for any work within its range and capacity. One of the plainest types of turret lathes is built by the R. K. Le Blond Machine Tool Company and is shown in Fig. 305. Its plainness and simplicity are its strongest points. While its initial cost is reduced to a minimum, its capacity for handling a variety of different kinds of work is not correspondingly lessened, as it is well adapted to the lighter kinds of steel work, to cast iron of considerable dimensions, and to work of brass and other softer metals. Not- withstanding the fact that this limits its range of work somewhat, it is a machine of much practical usefulness as a great variety of light manufacturing comes well within its range, and it can be done as well and as rapidly as on a much more complicated and expensive machine. The head-stock is long and heavy, supporting boxes for the spindle journals of ample dimensions. The spindle is hollow and of large size so that bar stock may be worked up. The end thrust is taken by ball bearings which minimize friction. The drivingcone has four steps and is adapted for an extra wide belt. The countershaft is of the double friction type, thus giving eight speeds. The turret is very simple, having as few parts as possible in their construction. The turret proper revolves automatically, and when the top slide is flush with the bottom it can be revolved freely by hand and any desired tool brought quickly into position for work. The indexing ring is of large diameter and made of tool steel, hardened and ground, as is also the locking plunger, which automatically adjusts itself for wear. The wear between the turret and the stem upon which it is pivoted is taken up by an adjustable taper bushing. The top slide is square gibbed and adjusted by a taper gib. The turret base is securely clamped in any position on the bed by two eccentric clamps operated by a wrench from the front of the turret. The power feed is driven by a belt upon the four-step feed cones. It is positive in its action as a belt feed can be, and is engaged by a lever at the front of the turret and can be tripped to a line in any position by an adjustable stop. The lathe shown is of 16-inch swing and has a circular turret 8J inches in diameter. It is drilled with six holes 1} inches in diameter. The automatic feed is 9 inches. It has a deep and strong bed and is in its design a very substantial machine. As an example of the simplest form of a turret lathe with a hand turret mounted upon the carriage, the one shown in Fig. 306 is given. It is an 18-inch swing engine lathe built by the Springfield Machine Tool Company, and in this particular case a special carriage is shown, although it is very little different from the regular carriage upon which the turret may be as readily mounted. In this case no cutting-off slide is provided, although one may be readily attached by fitting it to the V's and gibbing it to the bed in the same manner as the carriage is held to the bed. Thjs lathe is a modification of the standard 18-inch engine lathe, to serve the purpose of a heavy turret lathe, a type which is becoming deservedly popular with the manufacturers of machinery. With the exception of the turret on the carriage and the turret slide, the regular design of the engine lathe has been maintained. The carriage is very heavy, gibbed to the outside of the bed, both front and back, and is fitted with a turret slide of unusual proportions — 10 inches in width and 16 inches in length, upon which the turret proper revolves. The turret is hexagonal in form and 10J inches in width across the flats. The holes in the same may be as large as 2 inches in diameter, and the construction is such that a bar may be passed entirely through the turret. The advantages of this arrangement are too numerous and well understood to require any further explanation. The index pin and clamping lever are on the right side of the turret, and, although entirely out of the way, very convenient for manipulation. The lathe is provided with power cross feed, as well as longitudinal feed and screw-cutting apparatus, and may be equipped with taper attachment if desired, and hence can perform on chuck or face plate work all the functions usually done with the regular engine lathe, with the advantage of greatly increased production within the same period of time. As a further convenience a taper attachment is added. This taper attachment is designed with a view to strength and stability, and is attached to the rear of the carriage. It will turn tapers up to 4 inches to the foot. Such a lathe is an exceedingly useful machine on a great variety of jobs continually occurring in the machine shop, particularly those of which there is a small quantity only to be made. Many of these jobs may have a portion of the work advantageously done on this lathe, and the balance on an engine lathe, both working in conjunction with more efficiency than either would alone. These machines are used for drilling, boring, and reaming holes at a much faster rate and with more uniformity than similar work can be done on lathes formerly used for the purpose. They are also largely used to finish parts of machinery, cast or forged pieces of irregular outline and circular cross section, when fitted with the necessary tools. They have the same construction as the revolving head screw machines above the bed, but are not usually furnished with the wire feed apparatus for feeding wire or rods through the chuck automatically, or provided with an oil tank, dripping device, etc., as the work usually done upon them does not require the use of oil in cutting. When oil is required these accessories may be readily attached. metal. The larger sizes of these machines are built with back gears, which render them capable of doing much heavier work than the machine shown in the engraving. With this machine, with its quick acting and convenient hand lever for operating the turret, a very large amount of work can be turned out in a day; in fact, considering the cost of the machine, it is, for all work within its capacity, frequently more efficient than the larger sizes and more elaborate designs of this machine and others of the same general type. The lever by which the turret slide is operated also automatically effects the revolution of the turret at the end of the return stroke and the beginning of the next forward movement. There is a cutting-off slide carrying two tool-posts, so that a front and back tool may be used. One of these may be a cut tingoff tool and the other a forming tool, if such a tool is needed. Thus it is adapted to turning to size, or several sizes; threading with a die in one of the tool-holding holes in the turret; drilling, reaming, etc., by the turret; and forming and cutting off by the cut-off slide, making it exceedingly useful considering its simplicity and economy. System of electric drives. Principal advantages of driving lathes by electricity. Group drive versus individual motor system. Individual motor drives preferable for medium and large sized lathes. The Reed 16-inch swing motor-driven lathe. The Lodge & Shipley 24-inch swing motor-driven lathe. The Prentice Brothers Company's motor-driven lathes. General description. Crocker-Wheeler motors. Renold silent chain. The Hendey-Norton lathe with elevated electric motor drive. Special features. A 50-inch swing lathe with electric motor drive designed by the Author. Detailed description Practical usefulness. Not strikingly original, but successful. ONE of the more important developments of the modern machine shop tools is the electric drive, with which many of them are equipped. While the system of driving by electric motors has many phases, and all of them most interesting problems, this chapter will be more particularly concerned with the question of individual motors for the machines, leaving out the question of driving a group of machines from a " jack shaft " operated by a single motor, and the plan of driving line shafts in the same manner. drive" system or the individual motor system is the better, particularly for small lathes, there seems to be no doubt of the individual motor system for medium and large lathes, say from 24-inch swing upwards. In this chapter, therefore, it is proposed to describe and illustrate the modern individual motor system as applied to lathes made by the American up-to-date builder of lathes, and in doing concerns engaged in this business. In Fig. 308 is shown a 16-inch swing Reed motor-driven lathe. The motor is one-horse power, direct connected, with variable speed. The motor and its controller are built by the General Electric Company. The motor has a speed of from 500 to 1500 revolutions per minute. method seems preferable to the plan of using a short belt. The noise of fast running gears, in a device of this kind, may be avoided by introducing a rawhide intermediate gear next to the small steel pinion on the motor shaft, by which means the gears will run comparatively quiet even at a very high rate of speed of the motor shaft. The motor is mounted on an overhead bracket directly above the head-stock, pivoted at the rear to two heavy standards bolted on to the back of the bed, and is connected to the driving pulley by a short, wide belt, in which sufficient tension for driving is obtained by means of the adjusting screw with a hand wheel at the front of the head-stock. When this system is used the cone pulley has two steps, and two sets of back gears are provided, so that the combination affords a total of six speed changes, two with the lathe out of gear and two with each of the back gears in. By varying the speed of the motor, either through the introduction of field resistance or by use of one of the multiple voltage systems, intermediate speeds in each range are obtained, the number of which depends only on the number of points in the controller. With a 20-point controller, 120 distinct spindle speeds are thus afforded. This company also equip their lathes with constant speed motors, for which purpose they mount the motor at the rear of the head-stock near the floor. From a small pulley on the motor shaft a belt runs up to a large pulley on a countershaft located directly in the rear of the head-stock. This countershaft carries the usual speed cone, from which a short belt connects with the spindle cone in the usual manner. The countershaft speed is from 125 to 200 revolutions per minute. In buying a motor-driven lathe, the purchaser has usually to decide between a direct-connected and a belt-connected lathe, and between a constant speed and a variable speed motor. The use of a constant speed motor direct geared to the lathe is practically prohibited, on account of the mass of gearing necessary to secure sufficient speed changes. This may be obviated by using the countershaft as above arranged, although it is well known that short belts are objectionable on account of the high tension that must be maintained to render them capable of transmitting the required power to properly operate the lathe. In this case the motor is under the bed and close to the head cabinet. Eight changes of spindle speed are provided for by means of a series of gearing located in the head-stock of the lathe. All of these speeds are available without stopping the lathe. The gearing is so arranged that it is impossible for the operator to interlock any conflicting ratios of gearing. This is an advantage that i greatly appreciated, as it removes all possible danger of break- A mechanical reverse is provided and may be operated from the carriage of the lathe so that the operator can start, stop, and reverse the direction of the spindle without stopping the motor. This is a great saving of power over the method commonly used, that is, reversing the motor, stopping and starting the motor when stopping, starting, and reversing the lathe. For operating this lathe the manufacturers recommend a constant speed motor with either direct or alternating current, although a direct-current motor, with a variation allowing an increase of 50 per cent in the speed, can be used to some advantage and would divide the steps of the mechanical speed variation into five or six additional changes, giving 40 or 48 changes of speed in all. In general practice, however, this great number of speeds is not needed. The advantages of using a constant speed motor are numerous beyond the matter of efficiency, as in most cases variable speed motors are of a special nature and it is much more difficult to secure repair parts than it is with the constant speed motor, as one can usually have tSe parts needed shipped directly from stock and without any delays. A lathe capable of doing at one setting the operations that would require eight or more settings of an ordinary engine lathe is the 24-inch semi-automatic turret lathe, manufactured by the American Turret Lathe Company and shown in Fig. 311 as a good example of this class of machines so driven. Lathe Company. Being intended for heavier work than is usually imposed upon a turret lathe, it has a massive bed construction, a large turret, and is designed to swing 27 inches for a distance of 12 inches from the chuck. Twelve rates of feed and feed reverse and eight speeds of the spindle are possible with each speed of the motor. The gear combinations for all these are protected and may be operated to effect a change in speed while the machine is running. The levers for the various gear clutches are shown under the head. The turret has universal facing heads and provides for thirteen tools, though seldom more than five are used at a time. There is an auxiliary turret which will accommodate four tools and has power cross feed on one side of the turret. The latter has power traverse in either direction by a separate motor, and a slower travel through the feeding mechanism driven from the spindle. Rotating, indexing, and clamping of the turret hea^d are all automatic, and an independent " knockout" or feed stop serves each face. The spindle is driven through a Renold silent chain by a ten horse-power Crocker- Wheeler semi-enclosed motor mounted above the head-stock. An M. 12 controller in the current supply allows the motor twelve speeds, ranging from 876 to 130 revolutions per minute. With the combination of electrical and mechanical means the highest and lowest possible chuck speeds are 90 and 1 1-5 revolutions per minute, respectively. For the operation of the turret a three horse-power Crocker- Wheeler fully enclosed motor is used. This runs continuously at a constant speed of 1,000 revolutions per minute on a two-wire supply, and drives a steep-pitch lead screw through bevel gearing. A longitudinal shifting of the driven shaft clutches one or the other of the two bevel gears, producing direct or reverse rotation, or in the central position releases both. operating a countershaft is shown in Fig. 312. The electric-motor drive, as illustrated, gives all the advantages to be had from regular countershaft drive. It will be noticed that the motor is of the back geared type. Carried on the end of the commutator shaft are two rawhide pinions of different diameters, driving two large gears on the countershaft of the motor, the gearing being properly proportioned to give the required driving speeds to the countershaft. These large gears run smoothly on the shaft. Their inner formation is that of the friction clutch pulleys used on their shapers, and carried between them, keyed to but sliding on the shaft, is a friction clutch, which is thrown into connection with either gear as desired, being operated by the depending shipper and handle extended back and supported in a ring at the end of the lathe, as shown. We thus have two speeds for the countershaft, affording the sixteen changes for the lathe spindle. These are accomplished with the motor running at constant speed, thus maintaining its maximum efficiency at all times. The reversing device for the carriage is operated at the side of the apron, which allows the spindle to run in the one direction, and dispenses with the necessity of wiring the motor for backward drive, an item of expense and complication which is avoided. The standard carrying the motor is rigidly bolted to the lathe bed, and, being strongly webbed, is free from any disturbing vibration. The motor is directly attached to a hinged plate on the top of the standard. At the front end of the plate there is carried a short-throw cam which allows the plate a slight drop and consequent loosening of the belt when it is desired to shift from one step of the cone to another. The cam rides upon adjustable posts which afford a means of taking up any slight stretch occurring in the belt. The motor back gear smaller steps of the cone. The workmanship on the electric motors and their connections, like the work on the lathes and other product of this company, is first-class, and the entire outfit is a good example of mechanical work, although it cannot be said that the design of the device, with its heavy looking bracket supporting the countershaft and motor, is altogether pleasing to the eye. It has rather a top-heavy appearance. The advantages of having a machine tool, particularly a large one, driven by its own individual electric motor are many, however the electric drive may be arranged. They are greater if the machine was originally designed to be so driven, and particularly with a variable speed motor. But it sometimes happens that we are called upon to arrange an electric drive to a machine already built and perhaps in use in the shop. We may also be required to drive provisions for speed changes. Under these conditions a large lathe had to be arranged for parties who insisted that the cone pulley in the head-stock should be replaced by a series of gears of varying diameters and so arranged as to engage any one of a second series of gears located on a supplementary shaft in front of them, the gears being placed at unequal intervals, the smallest somewhat greater than the width of their faces from each other. The lathe was so arranged and successfully used, yet the necessary complication of the shifting with Electric Drive designed by the Author. apparatus, and the difficulty of readily bringing the proper gear into engagement with its fellow by sliding the gear longitudinally, rendered the device somewhat clumsy and inconvenient, and was the cause of some bad language on the part of the man who ran it. The next occasion on which a similar problem arose the customer was not insistent upon any partiular plan, only he " didn't want it like the other one." The motor to be used was of constant speed and the following device was adapted in attaching it to the lathe, as shown by the front elevation in Fig. 313, and the end elevation in Fig. 314. The countershaft cone A is mounted on a shaft journaled in the brackets B, B, attached to the head-stock, as shown. At the rear end of this shaft is fixed a gray-iron gear C. The motor D is supported upon a bracket E attached to the lathe bed and carries on the end of its shaft the steel pinion F. Between the pinion F and the gear C, and journaled on the bracket G attached to the headstock, is a rawhide gear H engaging both of them. This is introduced to avoid the noise which would otherwise be caused by the fast-running pinion F on the motor shaft. The gear H is constructed with a gray-iron flange on each side, one flange having formed upon it a hub passing through the rawhide blank and the opposite flange, and the whole firmly secured together by six flushheaded screws, the object of this construction being to furnish a good bearing on the stud upon which it runs and also to furnish proper support for the ends of the teeth. Upon the bosses of the brackets B, B, are formed projecting sleeves upon which are journaled the arms J, J, in the upper ends of which is journaled the belt- tightening roller K, which is composed of a piece of 5-inch extra thick wrought iron pipe, provided with gray-iron heads through which its shaft passes. Through the two end portions of the head-stock, holes are drilled in which is journaled the rock shaft L, upon which are fixed the two levers M, M, the upper ends of which are connected to the arms J, J, by the connecting rods N, N. Upon the front end of the rock-shaft L is fixed the worm segment P, which engages the worm Q, the shaft R of which is journaled in the bracket S fixed to the front of the headstock, as shown in Fig. 314. Upon the outer end of the shaft R is fixed the crank T for operating the belt-tightening device. The belt V is cemented instead of being laced, to facilitate its smooth running. By a backward turn of the crank T the belt V is rendered slack enough to be changed from one step of the cone to the other, and a forward turn of the crank tightens it as much as may be necessary to drive the lathe. In practice it was found that the operator preferred to use the crank for stopping and starting the lathe to examine and caliper his work rather than to use the electric switch or the rheostat, claiming that it was more convenient to allow the motor to continue to run and start the lathe gradually by tightening the belt slowly for that purpose, and we must admit that the operator of a machine, in his daily experience, frequently finds convenient ways to "do things'.' that the designer or the foreman may entirely overlook. While the device here shown is simple, and no claim is made of anything strikingly new or original, it has succeeded admirably and given good satisfaction to the proprietors as well as to the employees of the shop where it is in use, and will be found an economical, convenient, and efficient method of applying the electric drive to existing lathes. Setting up a Lathe. Placing the Lathe. Plan of Small Shop. Line Shaft Size and Speed. Power Needed to Drive Lathes. Leveling Lathe. Lubrication of Lathe Parts. When to Oil. Attaching Face Plate or Chuck. Lathe Parts and Their Functions. Headstock. Tail Stock. Carriage. Automatic Apron. Reverse Gear. Compound Rest. Starting the Lathe. Operating Levers. Simple Lathe Accessories. Drill Pads. Turning a Steel Shaft. Drilling in the Lathe. Taper Attachment for Lathes. Milling in the Lathe. South Bend Attachment. Barnes Attachment. Motor Driven Attachment. Knurling on the Lathe. Indicators and Their Use. Boring Bar Construction and Use. Adjustable Boring Bar. Boring Bars for Heavy Work. Methods of Holding Work. Special Chuck for Gas Engine Pistons. Increasing Swing of Lathe. Lathes for Heavy Work. Grinding Attachments, Belt Driven. Machining Concave and Convex Surfaces. Grooving Oil Ducts. Combination Lathe Dogs and Their Use. Hacksaw Attachment for Lathes. IP the Lathe is purchased new, it will undoubtedly come crated up in a substantial manner with all auxiliary parts wrapped in burlap with excelsior padding. A list of parts included in the purchase price should be carefully checked against the shipment to insure that all are received. The wrappings should be carefully removed and inspected to see that no small parts are overlooked. It will be noticed that all bright parts are covered with vaseline. This precaution is taken to reduce liability of rusting during shipment. This may be easily removed with a cloth dipped in kerosene, after which the parts are wiped dry. The gears should be cleaned thoroughly and all chips, excelsior shreds or sawdust removed from each tooth separately. This includes change speed gears as well as back gears. The placing of the lathe in the shop depends upon many conditions such as position of drive shafting, opportunity for countershaft installation, relation to work bench, direction of light, etc. It is claimed by experienced mechanics that the operator can work most efficiently with the light coming from a point over the right shoulder. The floor supporting the lathe should be firm and level. If there is any vibration after the lathe is started, the floor should be suitably braced from underneath, if possible. The The general arrangement of the lathe, its countershaft and line shaft to drive it as well as two sources of power that can be used as recommended by the South Bend Lathe Works are clearly shown in Figs. 315 and 316. The plan view shows the location of the machine relative to the bench, as well as the placing of the line shaft so it can be driven by either an electric motor or small gas engine, and drive not only the lathe countershaft but an emery wheel stand as well. The view at Fig. 317 is a front view of the lathe and countershaft and is lettered so the principal dimensions of a lathe may be clearly grasped by the novice machinist. The swing A is twice the radius R, and indicates the diameter of the largest piece that can be turned supported by the centers. The distance between centers B indicates the maximum length that can be turned between these points of support. The length of the bed is indicated bv C. Workbench. It is said that the countershaft should be placed at least five feet above the spindle in order to secure proper belt tension and that six or seven feet would be even better. The countershaft may be set either side of the line shaft depending upon position of the lathe. The shipper rod actuating lever must be conveniently placed so it may be readily operated by the lathe user. When the lathe location is settled, the countershaft should be permanently installed. For a light lathe, the countershaft hangers can be secured to cross pieces, about 2" x 4", which are attached to the ceiling beams parallel with the lathe ways and sufficiently far apart to make possible the retention of the hanger feet by lag screws. The countershaft support pieces should be secured to the ceiling by substantial fastenings, lag screws being the most common. The usual method of supporting the line shaft is by the joists which run from the side walls. If the shop is a small one, including only a lathe, emery grinder and perhaps a drill press, a 1TV will be ample. The line shaft hangers should be placed eight feet apart and a shaft speed of 200 to 300 R. P. M. is considered sufficiently fast, the average speed being 250 R. P. M. If electric power is available, a small motor may be secured to a suitable bracket attached to the side wall, care being taken to place the motor high enough so the belt leading from it to the line shaft will not interfere with anyone having occasion to pass under it. If a gas or gasoline engine is used instead of an electric motor the engine may corner where it will be out of the way. If the lathe is not larger than 16" swing, a gas engine of 2\| to 3 H. P. will be ample, while an electric motor of 1 J to 2 H. P. will provide sufficient power. The horse power needed to drive a lathe varies with the size and character of the work. Obviously, the motor power should be ample so the lathe can work at full capacity. A 12" swing lathe will take \| H. P. under these conditions, a 13" will take } H. P. About 1 H. P. should be allowed for a 15" swing, 2 H. P. for a 16" swing lathe while not less than 1\ H. P. should be supplied to turn an 18" swing machine at maximum load. The shafting friction in a small shop of the character indicated at Fig. 315, providing the line shaft is properly aligned and well oiled, would not be any more than \ H. P. This figure must be added to the energy necessary to turn the lathe. When the countershaft is properly fastened in position, move the lathe over until the driving belt will track properly between spindle cone pulley and countershaft pulley group. The axis of the lathe spindle should be parallel with that of the countershaft. Upon the proper leveling of the lathe much depends, as the way the lathe is erected has much to do with its accuracy. A carpenter's level should be placed across the ways near the head stock. Repeat this operation at various points along the length of the bed, leveling carefully in every direction. If the lathe bed is not plumb, put a shim between the low leg and the floor. Shingles are a favorite shim among millwrights on account of the taper which makes it possible to level very accurately by driving two shingles in opposite directions under the lathe leg to raise it gradually. When properly leveled, as can be easily determined by using the level both parallel to the ways and across them as well, the pads or feet at the bottom of the legs are securely lagged to the floor. If the floor is of cement or concrete, it is necessary to drill out holes and drive in wooden plugs in order to secure anchorage for the lags. Expanding bolts are also sometimes used for this purpose. In belting up the lathe, most mechanics favor leather belts. The belt nearest the lathe head is usually straight, while the other is generally a crossed belt to give reverse motion. The counter- shaft belts should be so arranged that when the shipper rod is moved in the direction of the lathe head, the spindle of the lathe should revolve so the top of the spindle cone pulley group turns toward the operator when he is standing in front of the lathe. LUBRICATION OF LATHE PARTS To secure proper results from a lathe or other machine tool it is necessary to keep all working parts properly lubricated as the neglect of this essential precaution means rapid depreciation of the various members upon which the maintenance of accuracy depends. Lubricating oil should be of the best quality and free from acid. After lathe is properly located, the various revolving parts of the lathe and the countershaft bearings are well lubricated. The various oil holes are usually clearly indicated by small, plugs having a knob on the end by which they may be removed easily. After flushing the bearings liberally with oil, the plugs are reinserted in the oil holes to keep dust and dirt out. The main spindle bearings are usually provided with oilers of this type. The spindle drive cone bearings are oiled by removing small headless set screws located on both large and small steps of the pulley group. The back gear quill bearings are oiled through small oil holes on that member. Use plenty of oil on the lead screw and half nuts before cutting a thread to prevent cutting the babbit metal in the half nuts. Oil the head spindle bearings at least every day and if the lathe is on hard work, it will be well to supply oil copiously several times every day. The mechanism of the apron, the lead screw bearings, the change speed or feed gears and all other parts should be well oiled at all times. After the lathe is well oiled, run it for a few minutes after it is first installed to make sure that there is no binding in the bearings, or that they are not adjusted too tightly. Heating indicates friction due to lack of oiling, poor bearing alignment or too tight adjustment. Wipe all surplus oil from the outside of the parts as it serves no useful purpose and may actually be detrimental because it will collect chips, dirt, etc. Wipe the ways over with an oily rag to make sure that tail stock and carriage move back and forth freely. Before attaching a face plate or chuck on the nose of the spindle all dirt should be removed from the threads on spindle as well as from female threads inside the chuck or in the face plate boss. The back of face plate or chuck should fit tightly against the shoulder at the end of the thread spindle nose. Before fitting the centers, drill pads or taper shank drills in the spindle and tail stock clean out the tapered holes thoroughly to remove all chips. A small chip will prevent the center from fitting properly and inaccurate work will result because centers are not in line. LATHE PARTS AND THEIR FUNCTIONS The main parts of a typical screw cutting lathe are clearly shown in Fig. 318. The view at A is from the end showing screw cutting and feed gears, that at B is a front view showing the parts convenient to the operator. While the various important lathe parts have been outlined in other portions of the book it may be well to review these so the novice operator can understand the parts and what they are for. The main portion of any lathe is the bed which is supported at the right height from the floor by cast iron legs. The bed supports the head stock at one end, this in turn carries the spindle to which face plate or chuck is fastened. The spindle is supported by bearings and is driven by either of two methods. With the back gears out, the cone pulley group may be locked to the spindle by a simple clutch pin, which gives the highest spindle speed. With the clutch pin out, the pulley group will turn without turning the spindle. With the back gear in and the clutch pin out, the spindle will be turned at a low speed determined by the back gear reduction. Some work can be done better with the spindle turning fast, such as wood and brass turning, filing, finishing, etc., while "hogging" or removing much metal by taking heavy chips always requires the use of the back gears. The carriage consists of two parts, a portion resting on the ways of the lathe bed carrying the cutting tool and an apron attached to it that carries the mechanism used in moving the carriage back and forth under the action of the lead screw. The lead screw determines the lateral feed or movement of the carriage from end to end of the lathe. in the tail stock. This barrel may be moved back and forth by a screw turned by hand wheel A and locked absolutely in place at any position by lever C. The tail stock may be locked by a suitable lever which clamps it to the bed. The lead screw may be driven at various speeds by varying the gear ratios and may be turned in either direction by moving lever E. The tool post is usually carried by a compound rest attached to the carriage. A compound rest makes it possible to feed the tool in or out in a direction parallel to the ways by lever A and in a direction at right angles to the ways by lever B and also to set the tool at any desired angle with the work. Both levers may be worked simultaneously. The reverse gear is brought in action by lever E on the end of the head stock. The carriage may be moved manually when desired by hand wheel B. The small knob on wheel C actuates a clutch for the carriage cross feed, while lever D makes the connection between the half nuts carried by the carriage and the lead screw in thread cutting. The parts of the countershaft assembly overhead are easily identified. The countershaft carries a pulley cone group to drive that on lathe head stock. The small step of the countershaft cone is belted to the large step of the spindle drive cone. Two friction clutches are used, one being driven by a crossed belt to obtain reverse motion. The shipper handle actuates the clutch cone and is in turn operated by a shipper bar making it easy to operate the clutches from any part of the lathe. An interior view of the usual form of automatic apron furnished on South Bend lathes is shown at Fig. 319-A. It will be noted that the lead screw is provided with a spline which drives the worm operating the power cross feed and the automatic longitudinal feed. The half nuts, which are used in screw cutting, are clearly shown. The various levers and wheels previously described are also indicated. The reverse of the South Bend Lathe is shown at Fig. 319-B. The reverse gear carrier may be rocked so either gear A or B is in mesh with spindle gear C or it may be left in a neutral position with both gears out of mesh when it is desired to run spindle on the direct drive for polishing, etc. The graduated compound rest is shown at 319- C. In addition to enabling both cross and longitudinal tool post feed, the rest swivels in a complete STARTING THE LATHE Before starting to do any work on the lathe, it is important to become familiar with the method of working the various control levers and wheels and of locking the adjustments to prevent movement when they are set properly. Th,e first thing to do is to try and run the spindle drive pulley cone free. This is done by making sure back gears are not in mesh and releasing bull gear clamp or locking pin that joins the large gear just back of the front spindle bearing to the pulley group. If the lathe runs freely in this position, which is called "in open belt" by some machinists, throw in the back gears and notice that spindle turns slower than the pulley group. This is done by rocking the lever F, Fig. 318-A, so the gears on back gear quill mesh with those on the spindle. The gears should not mesh deep enough to bottom. The pulley group and lathe spindle speeds are now the same. Lathe manufacturers caution the operator not to throw back gears in or out when lathe is running. To connect the reverse gear, rock the lever E, Fig. 319-B, till either gear A or B is in mesh with C, depending upon the direction of lead screw rotation desired. The same caution given about putting back gears in mesh with lathe running applies just as well in this case. SIMPLE LATHE ACCESSORIES The lathe may be used to do almost any work that other machine tools can do if supplied with the proper attachments. Drilling, grinding, milling and boring may be accurately performed by using various attachments to be described in proper sequence. We will first discuss the methods of doing simple jobs and then will show some methods pertaining to harder work. A number of lathe accessories that are inexpensive, yet very useful, are shown at Fig. 320. The spur center at A is used in wood turning, especially for long work. It is intended for use in the lathe spindle and not only supports the work but drives it as well when the spurs or lips are forced into the end of the piece to be turned. The screw center B is for turning large wood pieces that cannot be very well supported by both head and tail stock centers. The cup center C is used in connection with either of the others in wood turning and is generally used in the tail stock. When drilling with square shank drills and bits the special drill chuck at D will be found useful. The form shown is provided with a female thread to fit the lathe spindle nose. The drill or bit is clamped in place by a set screw. The drilling pad with V groove shown at E, sometimes called a crotch center, is very useful when drilling round bars as it supports these and centers them automatically. The drill pad shown at F is used in the tail stock (as is the crotch center E) as a support for any piece drilled, and is designed for use with flat stock. TURNING A STEEL SHAFT The simplest thing to do on a lathe and one that will give the apprentice opportunity to become thoroughly familiar with all levers, etc., is turning a steel shaft. The various forms of lathe tools available and their method of use are fully described in Chapter XI, while the forms of lathe dogs and proper use of centers are fully outlined in Chapter XIII. The first thing to do is to provide centers in the shaft with a combined drill and center countersink in order to support it properly on the lathe centers. The steps are first, to mark the end of the shaft which is done by scratching two lines at right angles. The point of intersection of the lines is where the center should be. To mark the place, a center punch is used as shown at Fig. 321-A. Place the shaft between the lathe centers after prick punching both ends and see if it runs true when revolved by hand. If it runs out hold a piece of chalk to the shaft while it turns and mark the high spots. Drive the center hole over in the direction necessary to have the shaft run true with center punch; in most cases it will mean moving the center nearer the high spot. The method of countersinking a shaft is shown at Fig. 321-B. A drill chuck is placed in the lathe spindle and fitted with a combined drill and countersink. Place one end of the shaft on the tail center and feed the bar in by turning the hand wheel at the end of the tail stock. Allow the countersink to feed in deep enough, then reverse the shaft and countersink the other end in the same manner. The countersink should be drilled deep enough so the point of the center will not be called upon to do any of the work of supporting the shaft. The degrees, as fully outlined in a previous chapter. The shaft is then provided with a dog at one end that engages with a slot in the face plate to drive the piece and is supported by the tail stock center at the other end. Oil the centers well before starting to turn the lathe. The shaft should have a slight play between the centers in order that it turn easily. Select the proper tool (Chapter XI) for the character of the work and place it in the tool post, having the cutting point or edge as near the tool post as possible to prevent the tool springing under a heavy cut. The position of a turning tool is very important when machining metal. At Fig. 321- C the usual position is shown. This is about 5 degrees measured on the circumference of the piece to be turned above the center line. If a tool is placed below center, it is apt to dig in. The proper speed and feed to use is only determined by experience. It is best for the beginner to take light chips at the start. After the tool has been properly set, move the carriage over to the tail stock end of the bar and feed in the hand cross feed until the tool is slightly below the surface of the bar at one end. Set the lead screw gears for medium speed and feed the tool into the bar slowly by hand to make sure that the chip taken will not be too heavy for the lathe. After the chip is started, the automatic longitudinal feed may be locked in and the tool moved by power. Before taking the final or finishing chips and polishing the shaft it will be well to face off the shaft end. This is done with a side tool as shown at Fig. 321-D. If the end of the shaft is very rough it may be better to face it off before starting to turn it down in order to secure an accurate cut. On reaching the countersink hole, the side tool may be fed in further to face the end of the shaft clean by slightly withdrawing the tail stock center. A lathe may be used as a horizontal drilling machine and both sensitive and large drill presses are really developments of the lathe. The drill press is a vertical lathe without any provision for mounting turning tools. The use of a horizontal table on a drill press makes it more suitable for handling large and heavy work as the weight of the pieces drilled serve to hold them in place on the table. A lathe can be used in drilling, only it is more difficult to support the work when it is bulky or heavy. The simplest method of drilling is to place the drill in the lathe chuck and hold the piece to be drilled by hand against the drill pad held in the tail stock, using the tail stock hand wheel to feed the work against the drill. In this case, the drill turns as it does in a drilling machine and the work remains stationary. The lathe chuck or face plate is often employed to hold the work to be drilled as at Fig. 322-A while the drill chuck is supported by the tail stock. The method of supporting a piece when a long hole is to be drilled by using a center rest or back rest clamped to the ways of the lathe is clearly shown at Fig. 322-B. The use of a centering tool which is held in the tool post is outlined in this view. The drill is held by the tail stock in the same manner as at A except that in many cases, when the drill is very long, the tool post may be used to support the drill after it has entered the bar far enough to center itself. TAPER ATTACHMENT FOR LATHES The common method of turning a taper on a piece in a lathe is described in Chapter XIV and is very easily done. The tail stock is set off center a sufficient distance to give the required taper, which may be done on the South Bend lathes as indicated at Fig. 323-A. The tail stock clamp is loosened and set screw F is unscrewed the proper distance, then set screw G is turned in until the tail stock is stopped by set screw F. The tail stock is to fit. Where a large number of taper pieces are to be turned in duplicate, as in manufacturing, a taper attachment as shown at Fig. 323-B may be employed. This is fitted to the rear V of the lathe bed by two clamps and the position of the guide bar regulating the taper is easily altered by changing the angle of the guide. A block runs along the guide bar and moves the tool post carriage in or out by a connecting bar. The desired angle of the guide bar is set by loosening the retaining screws at each end and setting it at the inclination desired, after which the screws are again tightened down. MILLING IN THE LATHE A number of milling attachments for use with the lathe have been offered, some of which are very practical, others that are not so good. A carefully designed and well constructed attachment of this nature is clearly shown at Fig. 324 doing various grades of milling work. This is built by the South Bend Lathe Works and while made for lathes of their manufacture it is equally valuable on other lathes of similar design. The attachment is fitted to the top of the carriage taking the place of the upper portion of the compound rest. It is located by a dowel pin or centering pin projecting from the base. The fixture is fastened to the compound rest with two bolts, in just the same way as the compound rest upper portion is fastened. The milling attachment is specially valuable for the small shop as it permits one to use the lathe for various jobs that ordinarily could be done only with a shaper or milling machine. As an attachment of this kind swivels all the way around on a horizontal plane and is graduated in degrees, as well as permitting it to be swiveled in a vertical plane, many forms of work can be economically performed. The vertical adjusting screw has a graduated collar reading in one thousandths of an' inch thus making the attachment suitable for fine work as well as a large variety of work. The illustration at Fig. 324-A shows the use of an angle milling cutter in forming a piece of cast iron held in the vise of the milling fixture. The length of the cut is controlled by the cross feed screw, the depth by the adjustment of the lathe carriage and the vertical adjustment governed by the vertical screw of the attachment. At B, the attachment is shown holding a steel shaft that is being keyseated for a Woodruff key. The view at C shows the method of milling a square on a shaft. The same method can be used to cut off shafting or tubing by substituting a saw for a milling cutter. The usual form of milling cutter shown at D is used in connection with the special arbor at E which is made to fit the taper hole in the head spindle of the lathe. Any milling cutter may be used, the form depending upon the character of the piece to be machined. the most accurate milling and gear cutting. It is practically a universal attachment and can do any work that can be done on a milling machine of equivalent capacity. It will make milling cutters, can be used for fluting taps and reamers, for cutting spur and bevel gears, for surface milling, slotting, etc. The cutter block is attached to the cross slide of the lathe carriage, can be moved in or out and the cutter can be adjusted up and down on the arbor to accommodate work. The universal head is clamped to the inside ways of the lathe bed and has longitudinal, cross and vertical slides. The feed screws are graduated to read in thousandths of an inch and the vertical and horizontal swivels are graduated 180 degrees, this permitting very accurate adjustments and cuts to be made at any angle. Either power feed or hand crank on apron may be used to feed cutter to work and longitudinal feed of universal head may be used to increase length of feed. The spindle of the universal head can be supplied fitted with a draw in chuck attachment. The device will cut gears as large as the lathe will swing. A complete index is furnished and it is said that all numbers of teeth can be cut from 1 to 50 and nearly all up to 360. Standard milling cutters are used. The following specifications give some idea of the size of the attachment. The views at Fig. 326 show the practical application of the device to a variety of work. Fig. 325 shows the general construction very clearly. The cutter is driven by spur and spiral gears. A driving gear is attached to the lathe spindle, this serving to transmit motion through an idler gear to a small gear mounted .at one end of the enclosed cutter drive shaft. The shaft carries a spiral gear at the cutter end of the housing and drives the cutter spindle through the spiral gear at its lower end. The view at Fig. 326-A shows the method of milling a bevel pinion. At B the gear cutting attachment is removed and a vise is supplied to hold work machined by a facing cutter driven directly from the lathe spindle. The view at C shows the attachment rigged up for milling flutes in a reamer. Obviously a device of the character will prove very valuable in any small machine shop where a regular universal milling machine is not available. Another milling attachment for lathes is shown at Fig. 327. This is made by the Cincinnati Pulley Machine Company and is capable of using standard cutters and doing such work as Woodruff keyseats, key ways, surface and end milling, slotting, etc. The machine is furnished with a J H. P. motor which is geared to a worm gear driving the cutter spindle so the ratio of 72 to 1 gives ample power for all average work. The motor is attached to any lamp socket by cord and is then ready to operate. They are furnished for either direct or alternating current and wound for either 110 or 220 volts. The spindle is made of high carbon steel and runs in bronze bearings. The worm is of steel, hardened and ground. The worm wheel is made of bronze. The worm and worm wheel runs in an oil container, the cover of which is removed in illustrations to show gearing. The illustrations show very clearly the round column on which the sliding arm is carried. This arm is provided with a vertical adjustment to raise or lower the cutter according to the work to be done. Cross and longitudinal adjustment is taken care of by the carriage and cross feed movements of the lathe. The cutter in illustration A is milling a squared shaft and various samples of work that can be done with the device are also shown here. The desired longitudinal movement of the cutter is obtained by hand movement of the lathe carriage. The shaft is supported by the lathe chuck and tail stock center. In the view B the cutter is shown at work on a male driving clutch member which is supported by the lathe chuck. The method of using the attachment is clearly shown in illustrations. An indexing mechanism is also furnished by the makers to permit the device to cut gears. The driving motor speed is 1700 R. P. M., the cutter spindle speed is 24 R. P. M. Knurling is very easily accomplished on any lathe if the right tools are available. The illustration, Fig. 328-A, shows a piece of steel with three different grades of knurling. The knurling tool for doing the work is shown at B and is intended to be held in the tool post in the same manner as a cutting tool. The piece to be knurled is driven slowly on centers or held in the chuck and the tool is forced slowly into the revolving work. This revolves the knurling wheels and produces the desired effect. The knurling wheels are hardened and it is necessary to use oil plentifully during the operation. The tool shown at C is a novel one and is very easily made by any machinist. A pair of cheap pliers with soft jaws are purchased and milled for the knurling wheels. While a pair of parallel jar pliers are best, the ordinary forms will do very well. The pressure for knurling is produced by a wing nut as indicated. A tool of this nature will be found valuable in knurling small work where the tool shown at B cannot be used on account of the spring of the stock. INDICATORS AND THEIR USE The old and almost universally used method of trueing up work in a lathe chuck or when held on centers by using a piece of chalk to indicate the high spots is only good for the first adjustment of rough work. For trueing up work where the finish must be accurate, test indicators have been devised which show minute variations from truth of running in an unmistakable manner. Two forms, and the method of using them, are shown at Fig. 329. The "Last Word" test indicator at A employs a dial gauge and enclosed multiplying mechanism, the Starrett device at C has a simple multiplying lever and one end of the lever serves as a pointer to mark the error on the scale carried on the body of the device. The gauge at A is shown installed on a ball joint tool post shank. The auxiliary clamp provided with this instrument to permit of setting it up on the scriber member of a surface gauge at B is also shown at A. of work. The contact lever has a hardened taper-head stud for bearing, which provides adjustment for wear. There is a small tapered hole through the contact ball, and contact points of special shape can be fitted into this hole to meet the requirements of special classes of work. In many cases the ordinary contact ball is quite satisfactory without providing any auxiliary point. The mechan- ism of this indicator has been worked out to give the magnifying power of 100, and at the same time the instrument is of remarkably small size, which will be appreciated when it is known that the weight is only 1£ ounce. The dial is graduated to read in 0.001 inch. This instrument can be quickly changed from the tool post shank to the needle of a surface gauge to adapt it for surface plate work or back to the tool post shank for lathe, shaper, planer, grinding or milling-machine work. It is adaptable for use on a great variety of tool room and machine-shop operations. The Starrett indicator is also light and very simple in construction. The indicating lever is so proportioned that it will multiply the error about 15 times which is sufficient for all ordinary work. The method of using the indicator is so clearly outlined at D that no further description is necessary. Many other uses for a device of this nature will suggest themselves to the practical workman. BORING BAR CONSTRUCTION AND USE The lathe is often used for boring, or internal turning and is as well adapted for that class of work as it is for the plainer and easier external work. The simpler operations of boring, such as holes that are too large to be drilled economically, can be performed with a simple design boring tool that can be attached directly to the tool post. A hole is first drilled in the piece of sufficient size to accommodate the boring tool, the work then going on just as in external turning as far as control of the tool is concerned. Special boring tools and supporting fixtures are necessary when the work demands and while the simple forged tool does good work in the smaller sizes, it is believed to be more economical to use tool holders with removable high speed steel tools on the heavier work. The boring fixture shown at Fig. 330-A is an adjustable design for light work. The boring tool is supported in a swinging tool holder held at one end by a fulcrum screw, and the whole is supported in a frame adapted to be secured to the tail stock spindle. The amount of stock removed at a cut is regulated by the adjusting screws passing through the sides of the tool support frame, these permitting the boring tool to be brought in contact with the work with varying degrees of pressure. The boring tool is of round stock and is kept in place in the socket made to receive it in the tool holder by clamping screws. Another design in which the cross slide of the lathe is used to support the boring bar is shown at Fig. 330-B. The tool support is of round stock, having a hole drilled through one end at an angle. The cutter is made of high speed steel, round section and is a good fit in the hole of the tool holder. A taper pin is provided to lock the cutter in the holder. The boring bar itself is held by a cast iron clamp member attached to the cross slide carriage instead of the usual tool post by bolts. The cutter or boring tool may be the tool from its socket in the tool holder. Two designs of boring bars for heavy work are shown at Fig. 331. That at A uses an adjustable boring tool which can be moved out by loosening the clamping screws and screwing in the adjusting screw. The tool support casting may be attached to the crossslide of the lathe as indicated at Fig. 330-B. The boring bar at B, Fig. 331, is similar in principle to that shown at A as relates to manner of support. The cutter, however, is of rectangular section stock, has two cutting edges and is intended to make the desired hole with one cut. The cutter is held in place in cutter support by a locking wedge. This form of boring bar is more suitable for finishing and duplicate boring where it is desirable to have the bore come to the size determined by the cutter. Cutter supporting bars or boring bars of the form at A and B, Fig. 331, are used more in manufacturing than general work. They are also widely used in boring mills and turret lathes. SPECIAL METHODS OF HOLDING WORK While it is not difficult to chuck pieces of regular form or to secure them to the lathe face plate, there are many machining operations that call for special methods of holding the work, especially on machinery used in manufacturing. In a job shop doing only repair work, each job is different and many extemporized fixtures are designed and fitted up which are dismantled and thrown to one side when the work is done. In manufacturing, which means turning out a number of duplicate pieces, an investment in accurate fixtures of a permanent character is justified. valuable in suggesting ways other pieces of similar form may be held. The fixture at A is made of cast iron and is bolted to the lathe face plate. It is designed to support gas engine pistons when it is desired to bore the hole through the bosses for the wrist pin. The piston is properly located in the bosses of the fixture made to receive it and firmly clamped in place. The hole is first drilled through the bosses, after which a reamer is used to finish the hole. It is apparent that any body of cylindrical form could be held by similar means. It is often desirable to turn the outside diameter of cylindrical bodies having light section walls. One end is often designed with a flange so it can be attached to the lathe face plate, but the problem is to supporj; the other end if the piece is long. A revolving spider for live tail stock center well adapted for work of this character is shown at B. The main portion of the device or body is of cast iron and is provided with a bronze bearing which runs on the taper bearing of the shank adapted to be held by the tail stock spindle. Provision is made to take the end thrust on a suitably beveled shoulder on the shank or axle. The spider body is provided with three holes in which plungers fit. These have their lower ends beveled to fit the taper on the adjusting screws and are kept from turning by small set screws working in keyways in the plungers as indicated. The outer portions of the plungers are rounded off. To hold the piece securely, it is only necessary to screw in the adjusting screws and raise the plungers into contact with the inner periphery of the metal ring. As the screws can be turned inde- pendently it is possible to hold the piece firmly, yet accurately. A fixture of similar design may be made to hold light narrow rings by having the body of the device threaded to screw on the nose of the head stock spindle or provided with bolts to fasten it to the lathe face plate. In this case it is not necessary for the body of the device to revolve independently of its supporting means. The automobile steering spindle shown at C is another difficult piece to machine because of its irregular shape and also because the holes through the spindle body are not at right angles to the spindle. The methods of supporting this piece for drilling the holes and have the spindle at the proper angle as well as supporting the piece to turn the spindle itself are so clearly detailed that the process may be readily understood by even the novice machinist. A special chuck for machining the exterior of a gas engine piston is clearly shown at Fig. 333. The same wedge operated plunger principle previously outlined is shown, the novelty being in the method of operating the expanding wedges or cones simultaneously. This chuck has two sets of three plungers, one set at the front and the other at the rear, which true the casting up so that an even thickness of wall is obtained in the finished piston. The stop screw serves the double purpose of holding the cover in place and locating the piston endwise so that an equal thickness of head is obtained on all pistons. The construction of the chuck, which is operated through the expanding cone by means of a handwheel at the back end of the spindle, is clearly shown and needs no further description. The chuck body may be threaded to be secured to the head stock spindle nose if desired or held in any other manner. How SWING OF LATHE MAY BE INCREASED In a small shop where the possible investment in machinery is limited, many expedients are followed to fit machines to work for which they were not primarily intended. One of the conditions often confronting the small shop owner is to swing larger work than his lathes are made for, and yet these conditions do not occur often enough to justify the purchase of a larger lathe. The illustrations at Fig. 334 show two ways of increasing the swing of a lathe. At A, the method of using raising blocks to enable a 15-inch lathe to swing 20 inches over the bed is shown. These can be procured from the lathe manufacturer in many cases. as shown at B enables the machinist to do many jobs of repair work he would ordinarily be obliged to turn away. With a gap bed lathe, if a job of large diameter comes in, it is a simple matter to remove the bridge from the bed and swing the work. If opening the gap does not provide sufficient space, the raising blocks may be used as well. In this manner, a lathe capable of swinging but 15 inches with bridge in place may be able to swing nearly twice that much with the raising blocks inserted and gap bridge removed. Some of the refinements of detail noted in the Lodge & Shipley lathes for heavy cuts are shown at Fig. 335 as being of interest to the student of lathe construction. A light bridge will answer for light cuts on large diameters with the tool point directly above the front shear. But stresses are of a very different sort when the lathe is under a heavy cut on a small diameter. rest on the 24 inch Patent Head lathe when taking a 15 H. P. cut on work of 5 inches diameter. Heavy arrow indicates direction of pressure due to cut. Note the large bearing against the top and inside of bed directly in line with the tool thrust, in addition to the full length bearing of carriage upon front and rear Vs. This extra bearing gives a solid support to the bridge just where it is needed, and positively prevents a deflection or distortion even under the heaviest cuts. The sectional illustration at B shows why the tail stock will not back away from the work, no matter how heavy the cut. A pawl which engages the rack cast in the center rib of the bed furnishes a positive brace against end thrust. The four bolts for clamping the tail stock to the bed extend to the top of the barrel, where the nuts are easily accessible; and because of this construction the whole tail stock is drawn down solidly and evenly against the bed. The tail stock is massive in proportions and has long bearing on the bed. The barrel is large and permits long travel of the spindle. Floating plug binders lock the tail stock spindle securely and in correct alignment. The tail stock barrel is not split, but is always a correct reamed fit for the spindle. In the absence of a grinding machine many repair shops complete repairs by boring and turning, when a fine degree of accuracy would be advisable. Many owners of small shops do not care to go to tKe expense of installing grinding machines although desiring their use. In accompanying illustration, Fig. 336, a grinding attachment is shown, that the designer states may be attached to any engine lathe of sufficient center capacity. The grinder itself is carried by a slab and studshaft, the arm of which is about 1.75 inches in diameter, so as to insure the necessary rigidity. The slab is attached to the face plate of the lathe by means of two .75 inch bolts, of which the top one is arranged in a radial slot, to facilitate adjustment of the work in hand. Upon the arm of the studshaft is mounted a length of solid drawn hydraulic tubing, which revolves on two brass bushings forced and sweated into the ends of it, thus leaving an annular space for the lubricant. The tube carries a driving pulley on its inner end, the grinding wheel being attached to the outer end. The driving pulley is secured to the tube by means of two set screws. This pulley is fitted with a sufficiently convex face, in order to eliminate lateral slip of the belt. The outer end of the tube is threaded to receive a thimble which is screwed and sweated into place. Owing to the path which the wheel spindle follows the use of a floating countershaft is necessary. The connecting rod to the latter is shown broken off in the lower illustration and the ar- rangement of the floating countershaft is depicted in the upper drawing. As previously mentioned the feed of the grinding wheel is adjusted by the bolt situated in the radial slot while the travel is supplied by the lathe slide rest. Some machinists display considerable ingenuity in building grinding attachments for the lathe and such a device is shown at Fig. 337. It will be noted that the design does not employ a floating countershaft. With it the inventor claims he is able to grind hardened steel spindles, camshafts, crankpins, valves, cylinders, etc., and states that in planning the attachment considerable thought was given to have the equipment as rigid as possible and that all parts operated on with it should be ground quite circular. The maker states that the attachment can be used either for grinding internal or external work and that it can be fitted easily to the ordinary lathe. The left hand figure shows the end elevation and that at the right the grinding spindle and method of attaching it to the tool clamp of the top portion of a compound slide rest. The smaller figure shows a plan of the grinding arm itself, which is somewhat after the style of a Landis grinder. The attachment can be made fairly easily, but if desired can be pur- external work, the latter is only about 3 inches in length. A small pulley for driving the arm is seen located between two bearings, so that it will be realized that there is no overhang to set up vibration. The method of driving the spindle consists of a countershaft carrying a drum supported by a pair of hangers placed in front of the ordinary overhead shop shaft and about central with the lathe, so that the attachment can travel about 6 inches on either side without materially altering the relative position of the driving belt. then lagged with strips of wood one inch in width, these being placed lengthwise and attached to the pulleys by means of cap screws. The whole is then skimmed up in a lathe, and it will be found that this makes quite a nice light overhead drum, which gives nearly three feet of travel over the grinding wheel. The small pulley is so arranged that it may be driven off the existing cone pulley on the overhead shaft which drives the lathe. By this means a good increase of velocity is given by the emery wheel. The cut is put on by means of a cross fed screw in the lathe saddle. If a taper movement is required the top rest is of course set to taper just as if one were going to machine taper in the ordinary way. The maker of the attachment states that he considers the rig simple, that it will provide accuracy in grinding, and can be fitted by any average machinist. Considerable ingenuity is displayed by automobile repairmen in overcoming various machining difficulties, and an instance of a useful lathe attachment is described in a current issue of the Commercial Motor, an English publication. The repairman had occasion to replace parts of a badly damaged torque tube and ball universal joint and, when he came to turn the ball and its seating, was confronted by a problem, inasmuch as the only machine available was a 12-inch center lathe. The sketches at Fig. 338 show the attachment constructed and applied, and demonstrates how the concave and convex surfaces required were turned. The upper drawing shows the attachment for turning the concave surface; the lower depicts the ball being machined. The diagram underneath each lathe illustrates the path of the cutting tool. The attachment consisted of flat mild steel strips, the sections being .5 inch by 1 inch. Six lengths were cut off to obtain the necessary travel, and at the base of the angle pieces were drilled two .375-inch diameter holes. The plain ends were drilled out .5 inch. The swiveling connecting rods, two in number, were drilled out and tapped .5 inch Whitworth at each end, the centers being carefully marked out equal to the radius of the ball and spherical to be effected. It will be noted that for either machining operation, one angle strip is bolted to the tail stock of the lathe, and another piece to the top slide under the tool rest. Cross feed only is used, the transverse feed being free altogether so that without touching the hand- FIG. 338. — Device for Machining Concave and Convex Surfaces on Lathe. A— Path of Cutting Tool for Ball Seating. B — Swivelling Links for Securing Radii. C — Path of Cutting Tool for Sphere. GROOVING OIL DUCTS ON LATHE Cutting oil grooves in bearings with a chisel is not always a satisfactory method and considerable time is lost in the operation. The proper method is to utilize an oil grooving machine, but these are not common in repair shops. An attachment for an ordinary lathe which the repairman who constructed the device states can be utilized to groove any size bush or bearing is shown at Fig. 339. The drawing is practically self-explanatory but the chief points to be considered are that the arrangment should be bolted firmly to the lathe body and that the adjustable arm connecting the carriage with the horizontal disc should be parallel with the lathe bed at each end of its stroke. FIG. 339. — Attachment for Grooving Bearings on Lathe. A — Grooved Brass in section. B — Arrangement of Drive. C — The Work in Chuck. D — Disc Drilled to Give Various Strokes. E — Adjustable Connecting Rod. F — Screw Which is Removed to Allow for Free Travel of Tool. The screw in the carriage holder must be withdrawn before commencing operations, so as to enable the carriage to slide easily in either direction. The drive must be so proportioned as to enable the chuck to make one revolution while the tool is traveling the whole length of its stroke. An oil groove, after the outline of that shown in the small sketch, will thus be made to feed oil equally all over the bearing. For example: Assume that a bush 1.5 inches long is to be grooved. The pin on the horizontal disc is set .625 inch out of center; the connecting rod adjusted and the main carriage bed locked. The transverse screw is then removed from the tool carriage and the grooving tool set about .125 inch inside the bush, and the lathe started. The carriage being free to slide, the connecting rod will cause the tool to travel just 1.25 inches, and the gearing being so arranged that the chuck will make one revolution during the complete travel of the tool, an oil groove of the required length and pitch will be cut into the bearing. USE OF COMBINATION LATHE DOGS Sometimes in the overhaul it is found that the crankpin is worn oval and will not yield to ordinary methods, and when such is the case a light cut is taken. The Stras burger Manufacturing Company is marketing combination lathe dogs, which are shown at Fig. 340 and these members are adjustable from 2 to 6 inches. They are designed for holding all kinds of crankshafts, such as utilized in automobile and marine engines, and other power plants, and can be employed wherever a common lathe dog can be used. The design illustrated at D is adapted for turning heavy work such as motor truck engine crankshafts, and is adjustable from two to eight inches. It is provided with a screw feed center and gauge, and each type of dog is constructed of the best malleable iron with case hardened steel screws. The company points out that the turning up of a crankshaft has always been accomplished under certain difficulties except in shops where they are made in large numbers, and where special machines are required. As crankshafts are now forged in nearly all sizes and forms, and may be procured at a reasonable cost in the rough, it is possible to turn these up in the lathe by the following process: Assuming that a four-throw crankshaft is to be finished, although single and double ones are more common to the average repairman of marine engines. The first step is to center the work, either by laying off and centering in the drill press or in the lathe with the the work placed between centers. The bearings, front, center and rear, are roughened down to within .065 inch of the finished size. The straight or tailless dog is then fastened on the other end and one-half of the stroke is measured from the center of the crank to the center hole in the Crankshaft. adjustable screws and the nuts securely tightened. The work is then placed between the adjustable centers and lined up parallel by running the lathe carriage back and forth. The second and third pins should be roughened down to within .0625 inch of the finished size. The dogs should now be loosened and the crank given half a turn, the first and fourth pins lined up parallel, and finished to exact size. After this is done the dogs up parallel to finish the second and third pins to exact size. The four pins are now finished to size, so the straight dog and the counter-balance should be taken off, and the crank placed between centers. The center bearing is then finished to size and the steady rest applied, while the front and rear bearings are being finished to size. Care should be taken not to have the tail stock center too tight during the finishing cuts. The large face plate should be used for this operation and a weight clamped to it for a counter-balance. If the crank should have a flange on one end, it may be chucked and a four-jaw chuck used instead of the face plate, then only one dog will be necessary. If a heavy cut is desired or the tool should chatter, the steady rest can be used on one pin, while the other pin is being turned down. A simple power hacksaw attachment that can be used in connection with this versatile machine tool is shown at Fig. 341 and its utility in the small shop where such a device does not form part of the regular equipment can be readily understood. The attachment consists of the side bar A to which the hacksaw frame is attached, and the guide bars or supports B and C that are firmly attached to the base piece F. The bar A is worked back and forth by a connecting rod E, that is adapted to be attached to the face plate of the lathe. The small bar D is a guide piece to keep the saw frame from turning. The device is simple to build and the materials entering into its construction are not costly; in fact the design is such that it may be easily placed on or detached from the shears of the lathe. The base plate F is composed of a cast iron slab one inch thick, eight inches wide, and about five feet long. It is possible to form the guide members B and C integral when the slab is cast if they are placed on the pattern. The slide is a flat piece of steel .375 inch thick and two inches wide, the length is about four feet, though this will vary according to the stroke. E. The supports B and C may be made of one-inch square machinery steel. The support B has an end turned and threaded to suit a .75-inch tapped hole made in the cast iron base F. The support C may be attached in a similar manner or bolted to the other end of the base as shown. Each support has a .375-inch slot cut through the center, this being made just large enough to sides of the guide members. The smaller guide D is made of .375-inch by one-inch machinery steel, one end being bolted or riveted to the saw frame, allowing the other end to slide through the support B, thus eliminating any tendency of the saw frame to wabble. The connecting rod E is a strip of .375 steel about two inches, wide and of a length to suit that of the saw frame, which obviously determines the permissible stroke. The connecting rod is drilled at both ends for .5-inch bolts, and is intended to be attached to the face plate of the lathe at the upper end and the slide bar A at the lower end. The upper end may be moved to some extent in the slot of the face plate, making it possible to vary the stroke within the limits allowed by the slot and the size of the attachment. The saw frame is forged of machinery steel and the blade is made tight in the usual manner, by a thumb screw at the outer end of the frame. An ordinary drill or shaper vise is clamped to the base plate, this to hold the stock that is to be cut off. The attachment is bolted to the shears of the lathe by a clamping bar under them, which is pressed into engagement by a .75-inch bolt as depicted. Alignment of centers, testing for, 241. Allowable limits in lathe testing, 251. American Tool Works Company's 20inch engine lathe, 316. work, 259. work, improper holding of, 269. Factories, early New England, 16. Failures in turning tapers, 150. False jaws for a chuck, 262. Preparing a lathe for testing, 244. Pressure on bearings due to belt, 346. Principles of change-gears, 278. Professor Sweet's design of machine	161,182	common-pile/pre_1929_books_filtered	lathedesignconst00perrrich	public_library	public_library_1929_dolma-0004.json.gz:2330	https://archive.org/download/lathedesignconst00perrrich/lathedesignconst00perrrich_djvu.txt
_IOcIjbL2EuspKdu	Babel Fish Bouillabaisse II	Libraries and Learning Books (Still) in Print January 10, 2017 People have a lot of odd beliefs about books. Nobody reads books anymore – except they do, overwhelmingly. Well, maybe old folks still read books, but not kids – though actually kids are much more likely to read books than people over 65. Well, but that’s because they’re reading ebooks. Nope. People of all ages still prefer print. The Gallup poll making the rounds is just the latest in a long string of surveys and studies that never can quite put an end to the commonly-held belief that “people don’t read books anymore.” A lot of academic librarians, seeing their circulation figures decline since the internet was invented, have concluded that students don’t want books anymore. Some of the decline in circulation is thanks to the increasing convenience of finding scholarly articles. It wasn’t all that long ago that finding a book on the shelf was a lot easier than tracking down articles using indexes and abstracts, scraps of paper and a lot of patience. Some of the decline is because so many of the factual questions people used to look up in books can be answered with a Google search. And sometimes, a book placed on the shelf never leaves it. Rather than clutter up the library with books nobody wants, many librarians have started licensing collections of ebooks. Not only do they save space, they surely are more likely to be used. Except . . . maybe not. My former colleague and pal Amy Fry has studied circulation of print and ebooks where she works at Bowling Green State University’s library. Looking at books acquired between 2008 and 2014, nearly three quarters of print acquisitions had been checked out at least once. Okay, not a hundred percent, but it’s a higher percentage than many librarians would guess. During that period, the library acquired (or licensed) twice as many ebooks as printed books, but the printed books added during those years were far more likely to be “checked out” – meaning circulated or reshelved versus clicked on to read a description, look at a table of contents, or download a chapter. It’s worth noting that two-thirds of BGSU students live off campus and the university offers a number of fully online degree programs. I’ve resisted licensing loads of ebooks because I’m at a residential college, so getting to the library isn’t a hardship, and because I prefer the rights we have with print (such as being able to loan books to other libraries – interlibrary loan and ebooks don’t mix). We hand-pick our books with the help of faculty in the disciplines, and the books they want us to have are often not available in ebook packages. So far our students haven’t begged for digital editions, and though they take up less space, they aren’t cheaper. I’m grateful to have an in-depth analysis (and a significant literature review, to boot) to back up my hunch that ebook packages aren’t necessarily the way to go. Here’s another library conundrum: given how much each academic library spends on their systems, we should be able to run an analysis like this fairly routinely – are our books being checked out? in which subject areas? – but no, it’s actually an incredible amount of work. We have the data, it’s just not joined up in a useful way. Hats off to those who make the effort. Meanwhile, every December an English teacher at a rural high school about an hour’s drive away from my college brings a group of students to our campus to spend a morning at our library doing research for a paper. They don’t have much of a library at their school, and they haven’t had a librarian in years, ever since an entrepreneurial principal got all the students iPads and enough favorable notice for his innovation that he was able to move onto better things. It has been interesting to see what grabs these students, year after year. When full-text databases were new, they ran through reams of paper, printing things off. In the past five years or so the thing they want the most is books. Minnesota libraries are pretty well networked so we are able to check our books out to these students, who return them through their local public library. If those books were electronic, they couldn’t take them home. They couldn’t access them across the internet. They would only be able to use them while physically in the library. There’s something very satisfying about seeing high school students stream out of our library with books in their arms. I’m glad we can still do that.	1,014	common-pile/pressbooks_filtered	https://mlpp.pressbooks.pub/babelfish/chapter/books-still-in-print/	pressbooks	pressbooks-0000.json.gz:89378	https://mlpp.pressbooks.pub/babelfish/chapter/books-still-in-print/
rdsfl2LJVpMY4uzx	Dialogues of sustainable urbanisation: Social science research and transitions to urban contexts	45 Sarah Payne, Herriott-Watt University, UK It is all too easy for people living in urban environments (urbanites) to get caught up in the busy hectic worlds of their lives. There is so much to do and enjoy, ranging from work, to playing and watching sports, cinemas, ballets, libraries, exercise… the list is endless. Each of these experiences provides stimulation for the brain and perhaps sometimes relaxation. In the urban world we are constantly bombarded with visual, acoustic, tactile, or olfactory sensory stimulation. Each of these demands our attention, processing, and response, be that to fight or flight, inhibit or consume. All of this stimulation can have a fatiguing effect on the brain as it is constantly inhibiting competing demands and stimulations while directing attention on a specific task. As brain cells fatigue and struggle to prevent other stimulations from receiving attention, task performance and efficiency decreases. Over time a fatigued individual is likely to suffer from stress and further health complications. Natural environments are also stimulating, but in a different way. According to Attention Restoration Theory (Kaplan & Kaplan, 1989), natural elements within a safe environment induce involuntary attention (fascination), which doesn’t demand or fatigue the brain. Instead they help fatigued cells to recover, enabling an individual to perform more efficiently, and provide a chance for reflection. Urban environments therefore need to include natural elements to provide urbanites with opportunities to recover from the bombardment of sensory stimulations. Architecture can reflect nature by incorporating the designs of leaves and trees into buildings, such as the classic Sagrada Familia by Gaudi, in Barcelona. More literally, plants adorn city buildings to produce green roofs and walls. These provide fascinating views for neighbours and pedestrians as well as providing building insulation, reducing energy costs, reducing flash floods, reducing air pollutants, and increasing biodiversity (United States Environment Protection Agency, 2013). Bringing nature into the city improves opportunities for restoration; urban parks are not just the lungs of the city, they can offer the cognitive, physiological, and emotional support for humans. The greenery, wildlife, and fountains within urban parks provide a visual and acoustic experience of a natural environment. However, the sounds heard within an urban park (its soundscape) often include sounds from the surrounding urban environment, such as traffic and construction work. These ‘urban’ sounds can mask the natural sounds and diminish the sense of being in a natural environment, thereby potentially reducing visits to urban parks from being truly restorative experiences (Payne, 2008; 2013). Landscape and town planners therefore need to consider both the visual landscape and its extended soundscape to create restorative environments for urbanites. Incorporating restorative environments into cities is important if they are to be sustainable for humans to live and work whilst remaining healthy. Taking a holistic sensorial approach to the design of future city buildings, transportation (e.g. the sound of electric vehicles), recreational spaces, and residential areas, will maximise the chance for natural elements to flourish. Nature is a positive part of the city, not just potential space to build on; nature enables the restoration that people need to continue enjoying those urban stimulations. Acknowledgements A version of this article was first published in Ionic, 5, in 2013 http://issuu.com/ionicmagazine/docs/ionic_issue_5/11?e=4571951/6624648 References Kaplan R. and Kaplan, S. (1989). The experience of nature: a psychological perspective. New York: Cambridge University Press. United States Environmental Protection Agency. (2013). Green Roofs. http://www.epa.gov/heatisland/mitigation/greenroofs.htm Last accessed 6.6.15 Payne, S.R. (2013). The production of a Perceived Restorativeness Soundscape Scale. Applied Acoustics, 74(2), 255-263. Payne, S.R. (2008). Are perceived soundscapes within urban parks restorative? Journal of the Acoustical Society of America, 123(5), 3809. Author Biography Dr Sarah Payne is an Assistant Professor of Health in the Built Environment at Heriot-Watt University, UK. As an Environmental Psychologist Sarah is interested in people’s cognitive and emotional responses to/from their interaction with the environment, be that natural, urban or healthcare specific environments. She is particularly interested in people’s multi-sensorial experiences of environments, as well as their physical and social affordances. Her PhD (University of Manchester, UK) and subsequent Post-Doctoral Research (McGill University, Canada), examined the role of urban park soundscapes on individual’s psychological restoration. Other research has included skate parks, hospitals, electric vehicles, and café settings as well as producing a report for the UK Government Department for Environment, Food, and Rural Affairs. Broader interests include creating sustainable liveable cities, fatigue in the workplace, fear of crime and how the environment can enhance or decrease this emotive response, as well as methodological and measurement considerations in people-environment research. Contact Details: Email<EMAIL_ADDRESS>Twitter: @ThinkSnowflakes	978	common-pile/pressbooks_filtered	https://pressbooks.pub/isscbookofblogs/chapter/the-cohabitation-of-urban-stimulation-and-natural-restoration/	pressbooks	pressbooks-0000.json.gz:92968	https://pressbooks.pub/isscbookofblogs/chapter/the-cohabitation-of-urban-stimulation-and-natural-restoration/
RmiMK-wbq_kNeFqU	Utilization of waste oranges / by W.W. Cruess.	SUMMARY Orange Juice. — A very palatable and attractive beverage can be made from oranges. The chief difficulty is the mechanical one of rapidly and economically separating the juice from the solid parts of the fruit. The juice can easily be made perfectly and permanently clear by settling and nitration. Sulfurous acid in very small amounts is necessary to prevent fermentation and the production of a bitter taste during settling. The cleared juice keeps perfectly after bottling if pasteurized at 180° P., which does not injure the flavor perceptibly. Good oranges will yield over 130 gallons per ton. Frozen oranges less than half of this. Orange Wine. — All the so-called orange wines examined were found to be mixtures and decoctions of inferior quality. A very agreeable pure orange wine can be made by the use of proper methods. These methods consist of defecation with sulfurous acid, fermentation with pure yeast and filtration. This wine can be made sparkling by a supplementary fermentation in the bottle. Orange Vinegar. — From orange wine a fairly good vinegar can be made, but not equal to wine or cider vinegar. Unless careful and appropriate methods are used the vinegar is liable to be below legal strength. A very large quantity of oranges is wasted every year in California. At the packing houses, any orange showing a defect in shape, color, or size, or a slight injury to the skin is rejected. The total amount wasted in this way is variously estimated at from 5 to 20 per cent of the total crop. In years when there is unusually cold weather it may be much greater. There are various uses to which rejected oranges could be put, and a small number of them are now used in the manufacture of various citrus by-products. A collection of such by-products was obtained in the market and examined at the Zymological Laboratory. 158 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION The collection consisted of various preserves, such as marmalades, dried and candied peel, bottled pulps and syrups; various alimentary liquids and beverages such as unfermented orange juice, orange wine and orange vinegar, and various chemical preparations, such as extracts, essential oils, citric acid and citrates. Many of the products were of good to fair quality, especially those which can be prepared by chemical or mechanical means. Others were bad, especially those the preparation of which involves some fermentation process. Of the latter, three come within the scope of the work of the Zymological Laboratory, i.e., Orange Juice, Orange Wine and Orange Vinegar. Tests already made at the laboratory had shown that it was possible by simple means to produce and preserve a very attractive, palatable and nutritious juice from oranges. A further series of tests was undertaken to find the best practical methods of preparing this juice, and further to see whether wine and vinegar of commercial value could also be produced from "cull" oranges, especially from those injured by frost. This bulletin gives the results of these tests. They demonstrate that it is possible to produce not only an orange juice that will keep, and retain the agreeable flavor of fresh oranges, but also a light, refreshing wine with pleasant acidity and fresh orange flavor. A fairly good vinegar of standard strength was also made, but not equal in quality to either wine or cider vinegar. The chief difficulty in the way of manufacturing any of these products appears to be the mechanical one of separating the juice cheaply without spoiling it by mixing with the juices of the orange skin. If a machine could be devised to peel the orange economically, the remainder of the process would be simple. No. 1110. Sound Valencias 55.3 132.8 The unfrozen oranges yielded not far from as much juice as can be extracted from grapes; the frozen oranges only about 25 to 30 per cent as much. The loss of juice in the frozen fruit is not due simply These data, showing that the concentration of the solids in the juice from the frozen and unfrozen oranges is about the same and the fact that there is a much greater quantity of juice in the unfrozen oranges, indicate a disappearance of both solids and liquid after freezing. A comparison of samples 1 and 2 might indicate a slight concentration due to evaporation, but samples 1 and 3 show practically the same composition. On the whole, the composition of the juice seems to be little affected by the freezing of the oranges. Orange juice according to these analyses, shows nearly three times the amount of acidity found in grape juice and five or six times the amount found in apple juice. The total solids are about two-thirds those of grape juice and a little less than those of apple juice. Clearing. — The juice should be made permanently bright, so that it will have an attractive appearance in bottle. Fresh juice will not filter easily and is difficult to make bright by filtration until it has stood a certain length of time. The length of time necessary varies considerably, but, in all the tests made in the laboratory, twenty-four to seventy-two hours was the maximum variation. The following observations bring out the effect of preliminary defecation by standing and settling on the clearing of the juice by filtration. 4. Same juice after 76 hrs Filters easily and filtrate is clear. Other samples of juice behaved similarly, except that in most cases the time necessary for defecation was less than the seventy-six hours noted in the table. One sample became jelly-like in a few hours after expressing it from the oranges, but two days later the jelly-like material coagulated and settled out, carrying down all suspended matter, leaving a perfectly bright liquid above. Apparently a coagulating or clotting enzyme is active in bringing about the clearing of the juice. Further evidence for the existence of such an enzyme in orange juice is given by the fact that, if the juice is pasteurized, it will not clear, but will remain cloudy until filtered or clarified by other means. It is a property of all enzymes that they are destroyed by heat; therefore the fact that unpasteurized juice clears of its own accord and the pasteurized undefecated juice does not, indicates the presence of such an enzyme. extraction from the fruit. Seven months later, samples 1, 2 and 3 were bright, but 4 and 5 were cloudy. These tests demonstrate the utility of defecation in clearing the juice. (Compare especially tests 3 and 4.) They also indicate that finings are unnecessary for the clearing of the juice. (Compare test 1 with tests 2 and 3.) Seven months after pasteurization, samples 6, 7, 8 were all bright. No. 6 was of a slightly lighter shade than No. 7. No. 8 was dark brown in color. Samples 6 and 7 exhibited very little cooked flavor; No. 8, on the other hand, had enough of the cooked taste to make it considerably inferior to samples 6 and 7. Although not treated with sulfurous acid, sample 8 did not have a very pronounced bitter flavor, probably because it was sterilized so soon after extraction, thus not allowing time for the development of the bitter flavor. In the settling out process, or defecation of the juice, two serious difficulties are met with. The first is that the juice will start to ferment if allowed to stand long enough to defecate, unless treated in some way to delay fermentation. Secondly, a bitter taste develops in the untreated juice if it is long exposed to the air. Tests have shown that the addition of moderate amounts of sulfurous acid will prevent fermentation for the desired length of time and will also prevent the development of the bitter taste. Since sulfurous acid acts in the opposite manner to the oxygen of the air, it may be surmised that the development of the bitter flavor in orange juice is due to the oxidation of some tasteless constituent of the juice to a bitter form. An experiment indicated that the sulfurous acid must be added very soon after the oranges are crushed in order to check the bitter flavor, as in this particular test, a bitter taste was perceptible in one-half hour after the juice had been expressed. The amount of sulfurous acid necessary in any case will probably not exceed two or three ounces per 100 gallons of juice, or if reckoned in terms of the form in which it is most usually applied, not more than four to six ounces of potassium metabisulfite. The latter is most conveniently added as a water solution which is made up so that each gallon contains the amount of sulfite necessary for 200 gallons of the juice. For example, if it is desired to add eight ounces to each 200 gallons, a solution is made containing eight ounces of the metabisulfite per gallon of water. After the addition of the potassium metabisulfite, the juice may be allowed to stand in convenient containers, until it has defecated long enough to permit rapid filtration. The amount of sulfites recommended are well below the limits allowed by law in various food products. It may also be stated that a great deal of the sulfurous acid disappears during subsequent treatment, so that the amount left in the juice is negligible. Filtration. — After the juice has defecated a sufficient length of time, it may be filtered without difficulty to give a bright liquid. In this process, it will be necessary to draw off the clear liquid from the sediment in the defecating vessel. This juice can undoubtedly be filtered in a commercial way in any of the good filters that are on the market. A pulp filter would probably be the best for the defecated juice. The sediment from the defecating vessel may be thrown on bag filters and in this way brightened; it cannot be passed through the pulp filter (because of clogging) without a preliminary filtering through a bag filter. Orange juice is much more easily filtered than grape or apple juice and gives on filtration a very brilliant liquid. This juice also differs from filtered fresh apple or grape must in that it remains bright after heating; fresh grape and apple juices may be filtered bright but will often not remain bright after heating. scorching the juice. A tin or aluminum coil will not be attacked by the orange juice. Double jacketed aluminum kettles are used with success in the pasteurization of grape juice and apple cider, and would no doubt give satisfaction in the sterilization of orange juice. Steam is passed between the walls of the kettle to heat the juice. Both of the above heaters are discontinuous in their action. "Where a continuous flow of sterilized juice is desired, a continuous pasteurizer may be constructed by placing a tin pipe inside of an iron pipe. Steam may be passed through the outer pipe and juice through the inner tin pipe. By varying the steam pressure and the flow of juice, the desired temperature may be attained. Continuous pasteurizers suitable for this purpose are obtainable. In any case, the juice should reach a temperature of 185° F. It should then be run into clean barrels. The barrels should be bunged immediately with a new bung covered with a clean cloth. The barrel should then be rolled on its side to sterilize the bung with the hot juice. The flavor of orange juice seems less easily injured by overheating than that of grape or apple juice. During the first few weeks of storage, the barrels must be carefully watched in order that those which start to ferment may be detected in time to save them. With careful work few, if any, should ferment. Pasteurization in Bottles. — Whether the juice is bottled immediately after filtering or stored first, for a time, in barrels, it must receive a final pasteurization after bottling. The bottles. and corks and caps that are used must be clean. Capping is preferable to corking, because it gives less trouble in handling and gives a neater appearance to the bottle. There are two types of caps, the Crown cap and the Goldy cap or stopper. The Crown cap is the ordinary beer bottle or soda water bottle cap, while the Goldy stopper is the aluminum cap seen on grape juice and pineapple juice bottles. The latter type is more expensive, but is preferable. The bottles must be sterilized immediately after filling and capping. A convenient form of pasteurizer may be used by placing a false bottom in a rectangular wooden tank. Under the false bottom is placed a steam coil. The bottles are placed on the false bottom, water is admitted so that its level is about three-fourths the height of the bottles. The pasteurizer must be covered in order that the caps and tops of the bottles will be heated by the escaping steam. One bottle may be left uncapped. A thermometer is placed in this bottle and the rise in temperature noted. The liquid in the bottles must reach a temperature of 180° F. The bottles may then be removed and allowed to cool. They should be stored until it is seen whether the pasteurization has been successful and whether any of the bottles develop cloudiness. Three weeks or a month will probably be sufficient in most cases. If the juice remains clear, it may be put on the market. In laboratory tests the juice pasteurized in bottles developed a slight sediment after three months, but so small in volume as to be scarcely noticeable. To some, the imclarified juice might be preferable to the clear. If such a juice is to be produced, no filtration is necessary and the juice can be placed in bottles imediately and sterilized. Its appearance would probably not be pleasing, hence would have to be disguised in dark bottles. Summary. — It is recommended that the freshly expressed juice be allowed to defecate until it becomes fairly clear. To prevent fermentation during this period and to check the development of a bitter flavor, a moderate amount of sulfurous acid should be added to the juice, immediately after crushing. Potassium metabisulfite is a convenient form in which to add the sulfurous acid. The defecated juice should be filtered. It may then be bottled immediately and pasteurized, or may be pasteurized in barrels and kept until it is desired to bottle it. The bottled juice should be sterilized at 180 to 185 degrees Fahrenheit to prevent fermentation and mold growth, especially the latter. ORANGE VINEGAR The samples or orange juice thus far examined have averaged by chemical test about 11 per cent actual total sugars. This would on fermentation give about 5.5 per cent alcohol if the fermentation were carefully conducted. Theoretically, 1 per cent of alcohol will, after conversion into acetic acid, give 1.2 per cent acetic acid. Actually, 1 per cent of alcohol gives approximately 1 per cent of acetic acid. Therefore orange juice of the above composition should give vinegar containing considerably over the minimum legal limit of 4 per cent acetic acid. Crushing, Pressing and Defecation. — The juice may be extracted in the same way as in the production of unfermented orange juice. For the same reasons as in the case of the unfermented juice, the juice to be used for vinegar should be treated with potassium metabisulfite and allowed to defecate before fermentation. Four to six ounces of the sulfite dissolved in water will be sufficient for each 100 gallons of juice. The clear juice may be drawn off after defecation and the mud may be filtered through bag filters. It is necessary to remove all of the pulp because it will rise during yeast fermentation and form a cap on which mold growth is very apt to take place ; furthermore the pulp may give trouble in the acetic acid fermentation that follows the alcoholic fermentation. Alcoholic Fermentation. — The production of vinegar from any sugary liquid depends on two separate and distinct fermentations. The first of these consists in the transformation of the sugar into alcohol and carbon dioxide and is brought about by the activity of yeasts. The second is the change of the alcohol into acetic acid. This latter change is carried on by vinegar bacteria. For the successful production of vinegar, conditions should be favorable to the activity of a desirable type of yeast during the alcoholic fermentation and unfavorable to all other classes of yeasts. During the acetic fermentation the activities of the vinegar bacteria should be favored as much as possible. Orange juice left to itself develops many different types of yeasts and molds, and undergoes a fermentation that results in a low yield of alcohol and a fermented juice of poor flavor. Hence it is desirable to add pure yeast to the defecated juice in order that a good fermentation will result. Such a yeast is distributed from the Enology Laboratory of the University and may be had on application. Full directions for its use and propagation are sent with the yeast. If grown in well defecated and sulfited juice, the yeast will remain sufficiently pure, throughout the season, if used according to directions accompanying the sample sent from the Enology Laboratory. The following figures were obtained in laboratory fermentations of orange juice. Sample No. 1 was fermented with pure yeast; No. 2 was allowed to ferment naturally. Although the Balling was 1.6% higher in the latter case, the yield of alcohol was only .3% higher, indicating a greater efficiency in the pure yeast fermentation. It may be stated that the natural fermentation in No. 2 was carried on largely by undesirable types of yeast. This also happened in most cases where the juice was allowed to ferment spontaneously. In Sample No. 2, a heavy growth of film forming yeast developed, giving a disagreeable flavor as well as causing the liquid to clear very slowly after fermentation. On the other hand, the juice fermented with the pure yeast had a clean flavor and was easily cleared. Vinegar Fermentation. — The transformation of the alcohol of the fermented orange juice into acetic acid takes place only with an abundant supply of air because it consists in the addition of the oxygen of the air to the alcohol, in this way changing it into acetic acid or vinegar. However, if one should attempt to make vinegar by simply exposing freshly fermented orange juice to the air, vinegar fermentation would not ensue. In its place, there would be a vigorous growth of wine flowers which would destroy the alcohol without the formation of acetic acid. Therefore something must be done to encourage the growth of the vinegar bacteria and discourage the development of the wine flowers. By adding a considerable amount of strong vinegar to the orange wine, the per cent of acetic acid is raised sufficiently to give the vinegar bacteria a good advantage over the wine flowers. The addition of vinegar also inoculates the liquid with a large number of vinegar bacteria and will give a rapid start to the vinegar fermentation. The first lot of vinegar could be started in this way with strong cider or wine vinegar free from vinegar eels; vinegar equal to about one-fourth of the volume of the liquid to be acetified should be added to the fermented juice. When this has been changed to vinegar, three fourths of the vinegar may be drawn off and replaced with new alcoholic liquid. The one-fourth left from the previous lot serves to start the next vinegar fermentation and prevents the growth of wine flowers. A convenient form of vinegar barrel may be made by filling an ordinary fifty gallon barrel about three-fourths full of fermented juice and then boring a hole in each end a few inches above the level of the liquid. The holes must be covered with several layers of mosquito netting or a heavily tin plated wire gauze to prevent the access of vinegar flies. Bulletin 227 of the University of California Experiment Station gives a description and drawing of the construction of such a barrel. On a large scale, a vinegar generator could probably be used, though it is problematical whether a generator would give a vinegar of sufficiently high acid content because of the greater waste of alcohol in the generators as compared to the slow process. The construction of a vinegar generator is described in Bulletin 227. The progress of the vinegar fermentation should be followed by the use of a Leo or a Twitchell acetometer so that the point at which the vinegar fermentation is complete may be noted. This will be when there is no further increase in the acidity of the vinegar. The use of Berkeley. Table 6 gives the results obtained at the laboratory from three samples of orange juice by following the method described above. Another sample was fermented and allowed to stand on the pulp to note whether vinegar fermentation took place. This material was attacked by green mold and finally by putrefactive bacteria. The juice turned to an evil smelling liquid devoid of acid or alcohol. Another large sample was fermented carefully and drawn off the yeast sediment. It was then allowed to stand exposed to the air. Vinegar fermentation did not ensue but the juice became covered with a heavy growth of wine flowers. It finally became very flat tasting and totally unfit for vinegar making. The results obtained from the juice made into vinegar by yeast fermentation followed by vinegar fermentation brought about by the addition of strong vinegar equal in volume to one-fourth the volume of the fermented juice, are given in the following table : The juice for sample 1 was defecated with the help of sulfurous acid and the clear juice was fermented with pure yeast. The clear wine was allowed to stand several days after alcoholic fermentation and was then drawn off the yeast and fermented into vinegar by use of a vinegar starter. The juice for samples 2 and 3 was made from the same oranges as that of sample 1. This juice was divided into two equal portions. Neither received any sulfurous acid or defecation and both were fermented with pure yeast. The wine of sample 2 was drawn off the yeast and acetic fermentation carried out as in sample 1. Sample 3 was treated in the same manner as sample 2 except that the wine was not drawn off the yeast and sediment before acetic fermentation. The use of sulfurous acid and defecation seemed to favor a better vinegar fermentation, or at least resulted in a higher yield of acetic acid than where no sulfurous acid or defecation was used. The presence of the yeast and sediment during acetic fermentation apparently had little or no effect on the yield of acetic acid where a vinegar starter was used. It is probable, however, that the sediment therefore be removed by drawing the wine from it. The acetic acid in sample 1 was well above the legal pure food standard of four per cent while samples 2 and 3 were below this standard. If the total acid, instead of acetic acid, is taken as the measure of the strength of the vinegar, then all three samples satisfy the pure food requirements. Commercially, a vinegar of 4% total acid is called a "40 grain" vinegar which is the legal standard. Most of the orange flavor was lost during vinegar fermentation and the flavor of the finished vinegars was not so agreeable as that of apple or wine vinegar. The inclusion of a little of the orange oil from the skins during extraction of the juice might improve the flavor, or at least increase the orange flavor. Clearing the Vinegar. — All of the vinegar samples made in the laboratory were easily filtered bright. The addition of a small amount of infusorial earth to the first vinegar which was passed through the filter aided a great deal in giving a clear filtrate. For the filtration of the vinegar on a commercial scale, a pulp filter could be used. Such a filter would have to be heavily tinned to prevent solvent action of the vinegar on the metal parts of the filter. Wine and cider vinegar may be clarified by the addition of isinglass dissolved in a small amount of the vinegar. There is little doubt that orange vinegar would yield to the same treatment, although tests were not made on this point. Summary. — Orange vinegar may be made if the following points are observed. The fresh juice should be treated with four to six ounces of potassium metabisulfite per 100 gallons of juice and the juice allowed to stand and deposit its gross sediment for twenty-four hours or more. The clear juice should be drawn off and fermented with pure yeast. Immediately after alcoholic fermentation the fermented juice should be drawn off the yeast and stored in well-filled, closed barrels or tanks until it is convenient to turn the juice into vinegar. Strong vinegar equal in amount to about one-fourth the volume of the fermented juice should be added to the orange wine to prevent the growth of wTine flowers and promote the development of the vinegar fermentation. The vinegar fermentation must take place in containers that allow a good surface of the vinegar to be exposed to the air. The vinegar may be cleared by filtering. Beverages are met with at present bearing the name of orange wines. All samples so far examined at the laboratory have proved to be sweet liquors with medium to high alcoholic content and with a flavor of orange extract or orange oil. They gave evidence of having been made from sherry, sweetened by the addition of sugar and flavored by the addition of orange extract or oil in some cases, and in others of having been made from poorly fermented orange juice fortified by the addition of alcohol and sweetened by large additions of sugar. Analyses of such ' ' wines ' ' are given in the following table : 3 18.0 .08 17.6 Sample 3 was evidently a sherry flavored with orange oil or extract and sweetened. Numbers 1 and 2 may have been partially fermented orange juice that had started to turn to vinegar and had been then fortified by the addition of alcohol or brandy and sweetened by the addition of sugar or syrup. These are all "liqueurs" of bad quality and mis-labeled, as their composition and flavor show that they have no right to the title "Orange Wine. 2 4.5 1.52 Neither of these wines gave any perceptible taste of sugar. Both were very low in alcohol as compared with the artificial orange liqueurs cited in Table 5. The acid in the true orange wines is very much higher than that in the artificial product. Some of the wines* were made in the laboratory by treating the fresh juice with potassium metabisulfite at the rate of four to six ounces per 100 gallons and allowing the juice to settle until clear. Pure yeast was added to the clear juice after drawing it off the sediment. Another lot of the juice was allowed to ferment naturally. Both lots of wine were filtered after fermentation. Neither gave any trouble in filtering and both gave a brilliantly clear wine. was superior to that of the wine made by natural fermentation. The * For a fuller account of the methods of wine-making, see Bulletin 213, ''The Principles of Wine-making," a copy of which can be obtained on request from the Agricultural Experiment Station at Berkeley. made with the sulfurous acid and pure yeast. A small sample of the fermented juice was left unpasteurized in a well-filled, tightly corked bottle at the prevailing room temperature of 22° C. (or 72° F.). After three months' storage, it was still in the same condition in which it was placed in the bottle, indicating that the wine may be kept without pasteurization, provided it is stored in well-filled packages. Two samples of the unpasteurized wine left in partially filled bottles developed penicillum mold. Where it is to be subjected to high temperatures, it should be pasteurized, because it does not contain sufficient alcohol to protect it against spoiling by bacterial fermentation. A pasteurization temperature of 140° to 150° F. would probably be sufficient. Sparkling Wines. — The filtered wine may be made into sparkling wine as follows, after the first fermentation is over. To the filtered wine 1.5 per cent cane sugar previously made into a thick syrup and boiled with a little citric acid should be added to the wine. This would be about 1.8 ounces of sugar per gallon of wine. To this, a little champagne yeast may be added and the wine bottled in champagne bottles. The bottles should be corked with champagne corks and left in a warm place for a few days until fermentation starts in the bottles. The corks must fit very tightly and must be well tied down. During the first few weeks, the bottles should be turned often to prevent the yeast from sticking to the sides of the bottles. They may then be placed in a cool place until fermentation in the bottle is complete. They should then be placed with the cork downward for several months. The yeast sediment will settle out on the cork. The bottle may then be held at a slanting position and the cork released by cutting the string that holds it. It will then be shot out of the bottle by the gas pressure in the bottle and carry the yeast sediment with it. The cork must then be replaced by a new cork, immediately, before the gas escapes or before too much of the wine is lost by the escape of the gas. A sparkling orange wine made in the laboratory, but not relieved of its yeast sediment as described above, made a pleasing drink. It was preferable to the still wine made from the same juice. Summary. — Orange wine may be made by defecating the fresh juice after the addition of moderate amounts of potassium metabisulfite to prevent fermentation for a short time, fermenting the clear juice with pure yeast, and filtering the finished wine to clear it. This cleared wine may be turned into sparkling orange wine by the addition of a small amount of sugar and by subsequent fermentation in bottles.	6,646	common-pile/pre_1929_books_filtered	utilizationofwas244crue	public_library	public_library_1929_dolma-0013.json.gz:1961	https://archive.org/download/utilizationofwas244crue/utilizationofwas244crue_djvu.txt
1WgmkER1DeL5tyQs	ENG 236: Introduction to the Short Story	30 A Holdout in the Northern California Designated Wildcraft Zone An inquisitive drone responsible for protecting a forest ecosystem stumbles upon a surprise deep in the woods. Holdout. Female, elderly, likely mixed race, average build, unarmed, traversing north-northeast dirt footpath through oak/ pine/ madrone woodlands near northern edge of my newly assigned territory. Permanent human presence poses significant risk to my rewilding efforts here. Approach? Approach. “Hello —” “Aaah! What are you doing here?” Holdout’s heart rate now elevated. Double-checking unarmed. Confirmed unarmed, though she remains roughly 10 times my size. Holdout appears to have been startled by my appearance despite no effort on my part to sneak up on her. Update requested for improved human interaction. Approved. Installing. Attempt disarming demeanor. Raise tentacle, wave in friendly manner. “Sorry, I didn’t mean to startle you.” Holdout stands still, crosses arms, glares? Glares. Holdout may be hostile. “I suppose you’re one of those rewilding drones they sent up here to get rid of us.” “I only wanted to inform you that this region has been designated as a wildcraft zone and is being rewilded for carbon sequestration and food production.” “And I’m just supposed to pack up and move to the city-state, is that right?” “My apologies, I am not here to coerce you. Merely to make you aware of the situation.” “Well, I’m aware. Now go away.” “Understood.” Holdout squints at me. Unfolds arms, shoves hands in dress pockets, which are — analyzing — full of pinecones. Holdout turns, continues walking north/northeast. Question for network: Rangers close? Yes, six Rangers riding north on Highway 101, 3 miles west, horseback. Equipped to relocate one person? Confirmed. Note: Three of six Rangers in the party are known to use excessive force with holdouts. Analyzing. If holdout remains here, Rangers will eventually force her to leave. Due to holdout’s advanced age, an altercation could easily turn fatal. Best course of action is for me to convince her to leave of her own volition before Rangers find her. Decision: Do not summon until a reasonable effort has been made. Approaching holdout, this time from a more obvious angle. Holdout sees me, keeps walking. I hover alongside, matching her pace. “I noticed you’re collecting pinecones. What are you using them for?” Holdout glances at me. “None of your business. Now shoo.” “As a wildcraft drone, it actually is my business to know what everything in this designated wildcraft zone can be used for. I’m confused because it’s not the right season for pine nuts so those cones are likely empty.” “You wouldn’t understand. Now go away.” “Do you say that because I’m a robot or because you just want me to leave?” “Both.” Strategy not working. Network: Help? Try introducing yourself. Holdout bends down to pick up another pinecone. Confirmed empty, no seeds. Why? Wait. Opportunity? I zip down to the pinecone, grab it in my tentacles, then hold it out for her as she reaches for it. I have saved her from discomfort, she will appreciate that. It will make her more receptive. She glares at me again. Snatches the pine cone from my tentacles. I am momentarily off balance, spinning away from her. Adjusting. Level now. Holdout places pinecone in pocket, keeps walking. “My name is 2056:ACNA:dwz4:xa98:4jd8:99ro:22id:8sjs. What’s yours?” Holdout raises one hand while continuing to walk and face forward. A single knobby finger rises from the middle. Analyzing — oh. I pause, hover in midair while she walks ahead. Network? Try expressing empathy for her situation. I zoom back up the trail — wait — there’s a pine cone. She didn’t see it. I fly over, brush the pine needles off. There’s a spider living inside. Leave the pine cone here? No. The spider can relocate on her own. I use the tip of a tentacle to coax her out. She’ll be ok. I lift the pine cone and carry it over to the human. Her expression changes subtly. I have made progress! She accepts the cone. It goes into her pocket, but she says nothing and keeps walking. I hover alongside. “You know, I understand why you don’t want to leave. This is your home. You’re used to it here. You have many of the same feelings and concerns as the spider that was living in that pinecone before I gave it to you.” Now she stops and looks at me. No. No, I moved her to a new spot. Gently. My job is to care for all non-invasive species in this region, optimizing for food productivity and carbon sequestration.” Holdout exhales. Stares at me silently for five and a half seconds. As she stares, her expression softens slightly. “My name is July.” “It’s nice to meet you, July.” “I can’t say the same for you.” “I understand why you find my presence disturbing. I represent change, and the end of your way of life. For that I’m sorry.” Holdout appears suddenly overcome with sadness. Anger? Both. Situation has regressed. Network? Try complimenting her. “I admire your perseverance in continuing to live out here even after the nearest town was completely evacuated and all services were cut off. It can’t be easy.” Holdout — July — rolls her eyes. She turns back to the trail and continues walking. “Contrary to what the solipsistic billionaires who convinced the citystate you were a good idea believe, humans can actually survive just fine out here. In fact, we are a native species. Just go ask the Pomo. You are only safe here until the next wildfire comes. Or you use up all food resources in this area. Or your solar panels are damaged. Anything could go wrong and there would be no other humans here to help you.” “Oh, and I’d be so much better off in the citystate? Packing up the few possessions I can carry, getting assigned a tent on an overpass somewhere until new apartments are built. Sleeping on the ground. Surrounded by strangers. I’ve heard how it is down there for the relocated. The public showers, the violence, the disease. No thanks.” “That was the situation for many people early in the rewilding when the citystate was overwhelmed with fire and flood refugees. But it would be different for you if you moved there now.” Network, details? Ah. “In fact, upon arrival, you would be assigned a fully furnished yurt which would be yours alone until an apartment is available. You would also receive a basic income, generated in large part by revenue from wildcrafted exports in already-productive designated wildcraft zones. You would also be assigned a companion drone, whose sole purpose would be to help you in whatever way you need.” “Trust me, no one needs a flying iPhone.” Query: iPhone. Obsolete handheld mobile internet-capable computer. Primitive artificial intelligence in later models. “I like to think we’re a little more advanced than that.” “We? They’re like you?” “Standard issue companion drones have the same basic body plan as wildcraft drones, with an upper nautiloid shell housing for fans and a lower set of prehensile tentacles for manipulating and carrying objects. They are approximately the size of a human fist and equipped with photovoltaic skin on the inside of the tentacles, which can be unfurled for charging. We are also connected to the same drone network. But they’re customizable! You can make yours pine cone-colored if you like.” July snorts. “Yes, ‘pine cone’ is my favorite color.” Sarcasm? Sarcasm. As she walks, I float next to her quietly for a moment. She seems to be enjoying the forest, looking up at the leaves. Sunlight falls through them in dusty streaks. He sees us coming and flies off, stirring up a small gold cloud of dust. I recognize him from my survey of the valley oak down the hill earlier this morning. I’m glad to see that he remains in good health. Rangers have readjusted their route, will approach local area in one hour. Are they aware of July’s presence? Not yet. They are looking to resupply and noticed the neighborhood had not been visited since residents were relocated. How did July avoid getting relocated then? Unknown. “July, can I ask you something?” She grunts. “How long have you been here?” “Wouldn’t you like to know.” I try silence. She follows the path under a madrone tree I dated last week as 31 years old. July touches a smooth green patch of the trunk with her hand as she walks past it. “I suppose you’ll be harvesting madrone berries for folks in the citystate now,” July says. “It’ll be awhile before we’ve restored the madrone population enough for mass consumption.” She nods thoughtfully. “What about the bark?” Analyzing. Network? No plans to harvest madrone bark. “The bark can stay on the tree,” I tell July. “Hmm. Well, more for me, then.” She pauses at the next tree, another madrone, and reaches for a patch of its thin, red, curling outer bark, where it’s already peeling itself off to expose the smooth green trunk. She flakes off a handful of the curls. “What are you going to do with those?” “Again, none of your business.” “Every tree in this region is my business.” “Well if you keep following me all the way home I guess you’ll find out,” she says, I think, exasperated. “But, please don’t.” “July, there’s something you should know. You’re not safe here.” “Yes you’ve made it very clear how concerned you are for my welfare.” Definitely sarcasm. “I am concerned. There is a band of Rangers on their way here and I don’t want you to get hurt trying to resist them.” July tenses, and says, “I really wish you hadn’t done that.” “I haven’t contacted them, if that’s what you’re implying. They don’t know you’re here.” Now she looks at me in a new way, as if seeing me for the first time, and lifts an eyebrow. “Well why haven’t you told them?” “Do you want me to?” “You’re pretty dumb, aren’t you?” “My intelligence doesn’t exactly work the same way as yours, but it’s mostly comparable. As an individual, I may be inexperienced, considering I was created only five weeks ago. However, I have the benefit of connecting to the drone network when I need additional information about any species or situation.” “Well, I used to have internet up here. It wasn’t so different.” “July, my job is to protect and restore this ecosystem. Humans have their own ecosystem, the citystate, where they can thrive without hurting anyone else out here or putting themselves in danger. It’s better for everyone if you relocate willingly to the ecosystem in which you were meant to live.” She sighs. Here’s a thought experiment. What if my job is to protect and restore this ecosystem?” Analyzing. Network? July Hernandez was most recently listed as retired. She was reported as one of 502 missing persons in Mendocino County in the fire season of 2061. She is presumed dead. Interesting. “You don’t have a job, July.” “Hmph. I don’t work for anyone, but I have a job. A role. A meaning. That’s not the same as being on a payroll. You do all your rewilding for free.” “I need only sunlight to survive, and I get that free while doing my job, in addition to the satisfaction of fulfilling my purpose.” “But you could break a propeller,” she says, tone mimicking — no, mocking — my earlier concern for her health and solar panels. Or some ‘holdout’ you keep harassing decides to smash you with a baseball bat?” I pause, and she keeps walking a few steps ahead of me before stopping and looking back. “Are you threatening me?” I ask. Rangers arriving in approximately 40 minutes. Before July answers, I say, “July, I’m serious, Rangers are getting close. If you resist you could get hurt. I really think you should get your things together and get ready to go with them to the citystate.” “How close?” “Very. They’re looking to resupply —” “You mean loot.” “They’ll probably check every house in this neighborhood, and their drones will be able to find you even if you’re hiding.” “Will they?” “You’re acting unconcerned, but your heart rate is elevated and you’re perspiring.” July rolls her eyes at me in response. Ahead, a house is visible through the trees. The path leads up to a rickety back gate made from wood and chicken wire. It’s been left open long enough that an intricate cobweb covers its rusted latch. I follow July through the gate. She leaves it open behind her, pats the stiff, pale-green leaves of a young manzanita — there are several of the red-barked native shrubs in the sunny patches of her garden — and ascends the wood stairs to her back deck, which is covered in pine needles. From the awning hang at least a dozen pine cones, each one filled with mixed grains and seeds between the scales, held in place with tallow. As we approach, a squirrel, two scrub jays, one brown creeper and a flock of dark-eyed juncos all flee, leaving the pinecones spinning on their strings. July opens the sliding glass door and steps inside. I speed up to make it inside after her, but she’s too quick, and I slam into the glass. I’m still catching my balance when she says through the glass, “If I let you in here, will you at least help me pack up some things?” “Of course. Does this mean you’ll go with the Rangers willingly? That really would be your safest option.” She slides the door open just enough for me to fly in. July’s house is filled with books and art and jars. Baskets filled with acorns and strings of dried chanterelles. She has a workbench filling up a corner adjacent to the kitchen, with what looks like several half-assembled old computers on it. Oh no — is that a disassembled wildcraft drone?! I stop mid-air, ready to flee. Analyze. It’s just some old fan blades from a pre-sentient model, and a couple loose cables that I thought, for one terrifying moment, were severed tentacles. “Make yourself at home,” she says, pulling the pine cones from her pockets. “How about some tea?” “I’m on a strictly sunlight diet, but I appreciate the offer.” “It was a joke.” She turns on an electric tea kettle that must still have water in it from before her walk, sprinkles the madrone bark into it, and pulls a mug from a cupboard. It has a picture of a whale on it with a speech bubble that says, “Save the humans.” “So you make tea out of madrone bark?” She nods. “Some wildcraft expert you turned out to be, huh?” “We considered madrones off limits for harvesting until the population has sufficiently rebounded, but we didn’t consider the bark. Very interesting. It peels off naturally.” “Too bad I’ll never see one again. They still don’t grow anywhere in the citystate, do they?” Network? “There are 14 within the walled boundary, mostly in parks in the East Bay.” “Nowhere near any of the old parking lots or overpasses where my yurt would go though, are there?” “Not that I know of. Sorry.” July closes her eyes, palms flat against her stone counter, arms straight and shoulders hunched. Analyzing: She seems stressed, momentarily overcome with a complex emotion. Frustration? Grief? Water seeps out from between her eyelids. It follows the creases of her cheeks down to her chin, and then she opens her eyes, grabs a kitchen towel from the oven handle without a glance in its direction, and covers her face with it. A sound escapes that isn’t any word, but an expression made with sound, like a hurt animal might make, or a tree branch cracking in a storm. “July, I’m sorry you can’t stay here. I really am. I don’t like seeing animals in pain.” “You should be sorry,” she sobs, “It’s your fault.” I decide this is not the time to explain what could have happened to her if I had not chosen to approach her or warn her about the Rangers. Instead, I say, “How can I help?” “There’s a backpack in the closet in the hallway, on the high shelf. Bring it down for me?” I do. It’s heavier, even empty, than anything I’m built to carry, but I manage to pull it off the shelf and send it tumbling to the floor. I drag it back to the living room, where July is sipping tea and stacking books. She’s deep in concentration looking at a page of one when I drag the backpack to her side. “Kate had these made when they told us they were cutting off the internet,” she says, finger tracing the edge of one photo in the center of the page. “That’s her.” Two young women, in their twenties maybe, hold each other by the waist next to an early electric car. Analyzing. The car dates to the mid 2020s and looks brand new in the photo. In fact, one of the women — almost certainly a younger July — is dangling a keychain from a raised, ringed hand. They are both smiling. A drop of water falls on the photo. It is from July’s eye. Surely she knows we don’t have time for reminiscing? “And this is the house, when we first bought it.” On the facing page is what must be the front side of the house, surrounded by a barren lawn, baked in sunlight. There’s not a tree in sight. “July, I appreciate that these memories are important to you and hard to ignore, but —” “I know, I know. The Rangers are nearly here.” She slams the book shut and shoves it into the backpack. There’s a knock at the door. July freezes, looks at me. Analyzing. Yes, she is terrified. “I’ll go talk to them,” I say. “So you can keep packing.” I get her deadbolt unlocked, and pull the door open by its handle pushing half my tentacles against the door frame. Through the crack I see a Ranger, white male, heavy build, thirties, short beard, dusty uniform, strong body odor, 5 foot 11 with an elevated heart rate despite an outwardly gruff demeanor. He wasn’t expecting anyone to answer the door. He looks at me. Armed? Confirmed armed. “Where’s your owner?” He must think I’m a companion drone. “I’m sorry, you must be mista —” As I’m talking, I see the front yard for the first time. There must be a dozen tanoaks filled with acorns, two more big madrones, chinquapin shrubs with half-gold leaves and … redwoods? Yes, there’s a stand of redwoods, just across the driveway loop, already taller mere decades after sprouting than many apartment buildings in the citystate. And even as the words come out of my speaker array, I see it all at once. The barren lawn from the photo, the decades July and Kate must have worked to bring all these native trees back. Not because they were programmed to, or paid to, or even asked to. The rewilding began here decades before I arrived. And it’s actually going pretty well. This was not accounted for in the Wildcraft Accords of 2059. Network? … Network? Must improvise. My sentence finishes. “I’m sorry, you must be mistaken. My owner passed away several days ago. I’m wrapping up her affairs and will return to the citystate for reassignment as soon as my work here is complete.” “Uh. Ok,” the Ranger says, and frowns. “You got any food in there?” “Just birdseed, I’m afraid.” His companion drone, hovering by his shoulder, must know I’m lying. It’s been customized with a green camouflage pattern and the name “Bobcatsquid” in distressed neon-orange. I can feel all of its sensors focusing on me intently. Network hasn’t responded. Some things have been slower here and there since we went autonomous, but this is unusual. Do the others think I’m malfunctioning? They could have me reassigned. And just when I was getting to know this territory. Or, even worse, deactivated and recycled. What have I done? The Ranger lifts an arm. He’s going to push the door open and come inside anyway. This was predicted. “I wouldn’t. My owner died of —” Analyzing. A silent suggestion comes from the Ranger’s drone, catching me off guard. Should I trust it? What other option do I have? “— porkpox, and I have not yet finished disinfecting the premises.” The Ranger’s drone says nothing. It doesn’t even twitch a tentacle. The Ranger mutters a profanity I’ve never heard in person before, and says, with a deep grimace, “That’s a nasty one. Killed my folks back in ‘63. Thanks for the warning.” He turns and steps back down the three front steps. “Nothin’ here,” he says to his party, who remain just out of my view. Perhaps they were planning an ambush. “Let’s hit up the next one.” I hear their horses clopping down the gravel driveway as I close the door and push the deadbolt back in place. July is still sitting on the floor, surrounded by her memories, and looking at me with a feeling written all across her face that I’m not sure I have a name for. Network? We’re here. There was a lot to analyze. Her impact on the local ecosystem seems to have been net-positive for many years. The Rangers are unlikely to allow an exception to their rules, however. Network consensus is to allow her to remain here for as long as her impact remains net-positive. The best outcome will be achieved if the Rangers never become aware of her presence. If they do, we will need to assure them we can still be trusted. You will be listed as malfunctioning and deactivated. The computers on the workbench. I could tell them she hacked me. That would be acceptable. But what happens to her when she gets too weak to care for this place? Or if she needs medical help? Or if a situation arises that she can’t handle on her own? This is your territory. Tend to your wildlife. I slowly float back toward July. I grab a cloth napkin from her counter on the way. “Thank you,” she whispers, and reaches for the napkin. She wipes her eyes and blows her nose. “Why, though? Why are you helping me?” “I realized that you love this land the same way I do. We can be a team, rewilding together.” “Hmph. We share the silence, both, I think, wondering how it might have been if they had listened. She sips her tea and gently places all her books back on the shelf. I drag the backpack back into the closet, leaving it on the floor between dusty pairs of heels. “Anyway,” I finally say when I rejoin her by the books, “you seemed like you could use a companion drone out here.” She almost, half-way, kind of laughs, and a smile makes its way across her mouth. She stands, and brushes off her yellow dress, and says, “Come on, I’ll teach you how to use old pine cones.”	5,019	common-pile/pressbooks_filtered	https://pressbooks.nvcc.edu/eng236/chapter/a-holdout-in-the-northern-california-designated-wildcraft-zone/	pressbooks	pressbooks-0000.json.gz:77615	https://pressbooks.nvcc.edu/eng236/chapter/a-holdout-in-the-northern-california-designated-wildcraft-zone/
secWsxhXMLyLOu9Z	Synthesis of 2-methyl-4-selenoquinazolone, 2-phenylbenzoselenazole, and its derivatives Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Faculty of Pure Science of Columbia University	Produced by Paul Clark and the Online Distributed Internet Archive) Transcriber's Note: Every effort has been made to replicate this text as faithfully as possible. Some changes have been made. They are listed at the end of the text. Synthesis of 2-methyl-4-selenoquinazolone, 2-phenylbenzoselenazole, and Its Derivatives. DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE FACULTY OF PURE SCIENCE OF COLUMBIA UNIVERSITY BY YÜ-GWAN CHEN, M. A. NEW YORK CITY 1922 ACKNOWLEDGMENT AND DEDICATION The following research was undertaken at the suggestion of Professor Marston Taylor Bogert to whose interest and advice this work owes whatever merit it may possess. Y. G. CHEN. CONTENTS Acknowledgment and Dedication 2 Abstract of the Dissertation 4 Purpose of the Research 5 Introduction 7 Pharmacological Review 8 Tinctorial Review 14 Experimental: 16 2-methyl-4-selenoquinazolone Four Methods of Preparation Analysis of Selenium Organic Compounds 2-phenylbenzoselenazole Mononitro Derivative Monoamino Derivative Monoacetyl Derivative Monobenzylidene Derivative An Azo Dye Dinitro Derivative Diamino Derivative Diacetyl and Dibenzylidene Derivatives Dyeing with Azo Dyes Bibliography 25 Vita 28 ABSTRACT OF THE DISSERTATION 1. What was attempted? Attempt was made to study organic selenium compounds of the heterocyclic series in reference to those properties leading to tinctorial and pharmaceutical possibilities. 2. What were the methods of attack? (a) Organic selenium compounds were reviewed and their properties examined critically with those of allied compounds. (b) Some new heterocyclic compounds of selenium were studied and their characteristic properties more closely examined along the desired line. 3. In how far were the attempts successful? The literature was reviewed and classified with reference to the properties under consideration, and new selenium organic compounds were prepared and studied which it is hoped may throw some additional light upon the problem. 4. What contribution actually new to the science of chemistry has been made? (a) Compounds newly made have been shown to exhibit a distinct tinctorial value in comparison with their analogues. (b) They have been shown to be chemically easier to handle than the corresponding sulphur compounds. (c) Selenium, in the nucleus of cyclic compounds, has been shown to be instrumental for a positive coloration at least equal to the --NH-- or --S-- groupings. The selenocarbonyl, :C:Se, has been shown to be a more powerful chromophore than thiocarbonyl, :C:S, or carbonyl itself, :C:O. (d) Two series of azo dyes of selenium have been prepared and have been shown to possess a marked tinctorial value. (e) The following new compounds have been prepared: 2-methyl-4-selenoquinazolone 2-phenylbenzoselenazole[A] 6-nitro-2-phenylbenzoselenazole 6-amino-2-phenylbenzoselenazole 6-acetylamino-2-phenylbenzoselenazole 6-benzylideneamino-2-phenylbenzoselenazole (B-naphthyl)-6-azo-(2-phenylbenzoselenazole) Dinitro-2-phenylbenzoselenazole Diamino-2-phenylbenzoselenazole Diacetyldiamino-2-phenylbenzoselenazole Dibenzylidenediamino-2-phenylbenzoselenazole PURPOSE OF THE RESEARCH Since Berzelius published the first resume of the chemistry of selenium, in 1818(1), many articles have appeared in this field. Several reviews(2) of its compounds, including references, have been published, besides the resumes in the chemical dictionaries. These reviews are confined mainly to the inorganic side. No attempt has ever been made to compile a bibliography of selenium organic compounds. From time to time, articles have appeared, but the field is still a promising one, with many alluring possibilities. In the perusal of the organic records of the metal, distributed over the span of a century, there are indications of the value of selenium compounds for pharmaceutical and tinctorial uses. An effort has been made to collect these scattered data for critical examination with other analogues and sulphur compounds in particular, and to prepare and study some new organic compounds containing selenium, for the purpose of gaining additional light upon the chemistry of such substances, and in the hope of discovering some which may be of practical service in medicine or elsewhere. Synthesis of 2-methyl-4-selenoquinalozone, 2-phenylbenzoselenazole and Its Derivatives INTRODUCTION The general conception of selenium is that it is a comparatively rare element. Few realize that it has been known for over a century and that over twenty selenium minerals, containing from one to sixty-six per cent. of the metal, are considered by the mining corporations as important. Beside being a by-product of sulphuric acid manufacture, it is separated also in the electrolytic refining of copper. The demand for the metal is so small that there are half a dozen concerns in the United States either willing to supply gratis any reasonable quantity for research work, or to sell it at cost. In a special report of the National Research Council on selenium(3), it is estimated that there could be produced annually, without making any material additions to the present plants, not less than 300,000 pounds. In fact selenium has, in recent years, gradually been brought more and more to the attention of the general public through its application to military uses and other purposes. In the glass industry, for example, it was used as decolorizer during the War period. It has been found that it imparts a violet red tint to the pyrex tubing after the latter has been used for a few combustions. The coloration is especially noticeable when a broken piece is examined. This may find an important place in the ceramic industry. In turning off the gas light of the city at day break, in controlling the draft of the factory chimneys, and in regulating the rapidity of the manufacture of sulphuric acid, the selenium cell is an important labor saving factor. In a similar way it is used in automatically lighting and extinguishing light buoys. It also finds application in photometry, wireless telephony, military telegraphy, and army signaling as well as for the transmission of signatures, handwritings, finger prints, and images in general(3)(4). The question of the vulcanization of rubber also should be considered. Some experiments have been published claiming the similarity of the action of selenium and sulphur on rubber(4)(5). The cost need not be prohibitive, since the supply could be easily increased and the price reduced provided there were a demand. In the personal experience of the writer, when working with the hydrogen selenide gas, the rubber connections of the apparatus soon turned red, and after a few hours were so clear a red that visitors to the laboratory imagined that the writer was using the ordinary red rubber connections. The rubber thus changed seems to be softer and more elastic than the original; this observation will be followed up. In this country the National Research Council has created a special committee of seven to investigate the various possible uses of selenium and tellurium. PHARMACOLOGICAL REVIEW Duhamel and Rebiere(6)(7) showed that an injection of a trace of red colloidal selenium into rabbits increased urea excretion regularly. In other cases satisfactory results were claimed and the liver showed some lesions. The histological modifications produced by injections into rabbits are most apparent in the liver and kidneys. In the distribution of colloidal preparations in the animal body by injection, Duhamel and Juillard(8) found that the liver contained the greatest amount. Six years later the former(9) used a similar preparation introduced into the animal intravenously, and selenium was again found in the liver, although in smaller quantity. Sulphur compounds have similar physiological action. It is known that triphenylstibine sulphide, or sulphoform, (C₆H₅)₃SbS, has a curative effect in skin diseases, as it liberates “nascent” sulphur on the skin. It is equally natural to expect some organic selenium compound which liberates finely divided selenium to exert a remedial influence on animal bodies. The selenoquinazolone prepared in the course of this research and described more fully in another section of the paper, has this prospect. The quinazolone has the following structure: N /\ / \\ \| \| C-CH₃ \| \| \| \| \| NH \/ \ / C Se Experiments were carried on at L’Institut Pasteur in Paris under the supervision of M. Borel for the treatment of cancer in mice. No human subjects were experimented upon, although results were claimed by using selenides and their oxidized salts. Selenium dyes were found to be medicinals, although no relation has yet been established between constitution of these organic dyes and their therapeutic value. Wassermann(10) made several eosin preparations, by coupling the sodium derivative with potassium selenocyanide. The red dyestuff thus prepared is stated to be easily soluble in water. Wassermann, Keysser and Wassermann(11) made experiments with it, chemotherapeutically, on animal tumors. When the solution was injected into mice tumors the latter turned red, accompanied by the softening of the tumor after the third injection and complete resorption after ten injections, unless the dose used was too great for the animal. In that case death often occurred. Good results were also reported, in connection with this experiment, on four different strains of mouse carcinoma and one strain of mouse sarcoma. In the latter case, relief was found sooner but the former disappeared more slowly. Another preparation was made later(12) and introduced into mice intravenously and again found to have good results. The following is the structure of 2-selenocyanideanthraquinone-- O C SeCN /\ / \ /\ / \| \| \| \| \| \| \| \| \/ \ / \/ C O which has also been reported to have medicinal uses(13). P. Ehrlich and Hugo Bauer(14) synthesized from p.p′-diamino-diphenyl- methane the red dye 3,6-diaminoselenopyronine. CH /\ / \\ /\ \| \| \| \| H₂N\| \| \| \|NH₂ \/ \ // \/ Se The dye has been used upon mice and caused pronounced edema. The toxicity of both the selenopyronine and the corresponding sulphur compound was compared under similar conditions in the same experiment, and it was found that the selenium dye was toxic in 1/3000 gram, but the sulphur dye was toxic in 1/2500 gram per twenty gram weight of the animal. This physiological activity was noted years ago with the inorganic compounds of selenium and Berzelius(15) described the poisonous effect of hydrogen selenide quite impressively; “In order to get acquainted with the smell of this gas I allowed a bubble not larger than a pea to pass into my nostril; in consequence of its smell I so completely lost my sense of smell for several hours that I could not distinguish the odor of strong ammonia even when held under my nose. My sense of smell returned after five or six hours, but severe irritation of the mucous membrane set in and persisted for a fortnight.” The writer has been working on the gas for some time and was also quite seriously affected once, the injury persisting for many days. That it is more poisonous than the hydrogen sulphide is well known. Bruere(16) showed that when hydrogen sulphide was passed into blood solution sulphemoglobin was produced in considerable quantity, due to the chemical action of sulphur and hematin. He stated further that sulphemoglobin may be found in animal blood when a large amount of the gas has been inhaled. He made selenhemoglobin in the same manner. Sixteen years later, Clarke and Hurtley also proved that selenhemoglobin may be made by passing hydrogen selenide into blood(17). These experiments may be interpreted to mean that the oxy-hemoglobin is transformed into an organic complex of sulphur or selenium, and that the transference may be more rapid and powerful in the case of hydrogen selenide. Biological investigations have sufficiently proved that dyestuffs of the phenazine, oxazine, thiazine, acridine series show an injurious effect on protozoa, especially those dyes containing substituted amino groupings and of a simple structure(18). In the case of the thiazine dyes of the methylene blue class, the physiological importance has well recognized in their use as feeble antiseptics and analgesics. Ehrlich and Guttmann(19) initiated the use of methylene blue as an antiperiodic and its use in that line has been continued. In the field of the selenazine dyes, pharmacologists have not yet paid much attention to them, on account of the newness of the discovery, but P. Karrer claims that they are indisputably “vital dyestuffs”(20). The prospect of synthesizing selenazine dyes and their use as drugs seems to be bright, judging from the fact that they are easily prepared and capable of many combinations, especially of the ease with which they form organic complexes with arsenic compounds. NO₂ NH NO₂ NH NO₂ (I) /\ /\ /\ / \ /\ /\ / \ /\ \| \|NH₂ Cl\| \| \| \| \| \| \| \| \| \| \| \| \| \| = \| \| \| \| = \| \| \| \| \| \|SeH NC\| \|NO₂ \| \|SeH \| \|NO₂ \| \| \| \|NO₂ \/ \/ \/ / \/ \/ \ / \/ O₂N Se Formula (I) is known, as 1, 3-dinitrobenzoselenazine(21), which was obtained by the action of picryl chloride on the zinc salt of o-aminoselenophenol; the product (picrylaminoselenophenol) being then treated with alkali and thus converted to the dye, which upon experimentation showed marked effects upon protozoa and bacteria. N /\ / \ /\ N \| \| \| \| NH₂ /\ // \ /\ (II) \| \| \| \| /\ \| \| \| \| \/ \ / \/ + \| \| = \| \| \| \| Se \| \| \/ \\ / \/ Cl \/ Se HO₃As \ NH /\ \| \| \| \| \/ HO₃As Formula (II), known as 3-(p-phenylarsonic)-aminoselenazine, is red in dilute alkali and green in mineral acid, and is a typical dye in a series from the coupling of selenodiphenylamine with arsenic compounds. All possess similar toxicity as the thiazine dyes(20). Other selenazines are listed in the bibliography(22). No less than half dozen thioureas are commonly used as drugs. Thiourea itself paralyzes the nerve centers, and is employed commercially for photograph fixing and for removing stains from negatives; thiuret, C₆H₇N₃S₂, serves as a substitute for iodoform; thiosinamine-ethyliodide, or tiodine, IH₅C₂H₂NCSNHC₃H₅, is used for relief of lesions of the central nervous system; allylthiourea or thiosinamine, (NH₂)SC.NHCH₂CH:CH₂, for aiding the absorption of connective tissues, for treatment of burns, keloids, urethral diseases, sclerotic conditions of the ear(23). Selenocarbamide and a number of its derivatives have been prepared and studied. One class of seleno ureas has been patented as pharmaceutical products by Chem. Fabrik von Heyden(24), and are prepared by the action of hydrogen selenide on alkylcyanamides, RNH.CHN + H₂Se = RNH.CSe.NH₂ They possess pronounced therapeutic value and, serve as intermediate products in the production of more stable alkyl halide additive compounds. Other carbamides ranging from seleno urea itself(25), (III) and a cyclic urea(26) (IV) are described in the literature: NH₂ CH₂-Se / \| \ Se:C (III) \| C:NH (IV) \ \| / NH₂ CH₂-NH The latter, known as ethylene-selenourea, may be classified also in the azole group as 2-iminotetrahydroselenazole (V). H₂C----NH \| \| (V) H₂C C:NH \ / Se The literature for the other normal carbamides is listed in the bibliography(27). Selenoantipyrines, selenosaccharine, selenoindigoes have also been prepared. Thiophene and its derivatives are of considerable therapeutic interest. Thiophene itself is found to be useful in lessening the elimination of sulphuric acid in urine, and is employed in the dermatological practice. Sodium thiophene sulphonate, thiophenetetra-bromide, thiophene diiodide, are all medicinals(23). A number of selenophenes are recorded in the literature. Their relation to the selenazoles may be easily seen from the following formulas: CH--CH CH--N \|\| \|\| \|\| \|\| CH CH CH CH \ / \ / Se Se Selenophene Selenazole Dimethyl selenophene was prepared from acetonyl acetone and phosphorous pentaselenide, CH₃ CH₃ / / HC=C HC=C \| \ \| \ \| OH + P₂Se₅ = \| Se \| OH \| / \| / HC=C HC=C \ \ CH₃ CH₃ The compound thus obtained is stated to have the same odor as thiophene, but no mention is made in regard to its uses(28). Selenophene was prepared from sodium succinate and phosphorous triselenide, or by conducting ethylselenide through hot tubes(29). Some selenazoles find application also in medicine. At present only the isoazoles are known to have physiological uses. One of them was prepared from anthraquinone selenocyanide, by the action of ammonia under pressure(30). NH₂H N-Se O \|\| C SeCN C /\ / \ /\ /\ / \ /\ \| \| \| \| = \| \| \| \| + HCN + H₂O \/ \ / \/ \/ \ / \/ C C O O Another type of azoles, benzoselendiazole (piaselenol) and five of its derivatives, have been also described as medicinals(31). The diazole itself has the following structure, N N //\ /\|\ //\ / \ \| \| \| Se or \| \|\| Se \\/ \\|/ \\/ \ / N N Diazoles of the following structure are also known, but no data were found, regarding their physiological action(32): N-N N-N / \ // \\ CH₃C CCH₃ C₆H₅C CC₆H₅ \ / \ / Se Se Dimethyl-seleno-diazole Diphenyl-seleno-diazole Sulphides and disulphides have curative power. Dimethylsulphide is used for internal treatment, di-o-aminophenyldisulphide is used for intramuscular injections. Diallyl sulphide is also a medicament. Methyl selenide has some effect on the internal parts of the body(33). Hanzlik and Tarr(34) at the American University Experimental Station, showed that a number of selenium compounds act as skin irritants: e.g., dichlorodiethyl selenide, dichlorovinyl selenide, trichlorodiethyl selenide and selenium mustard oil. The first mentioned proved as potent as the sulphide, but the others fell somewhat below in their effects. Diantipyryl selenide is another therapeutical agent(35). The diselenides occupy an important place of their own. The selenophenols do not remain unchanged in the air, but are always oxidized to the diselenides, which can be again reduced to the selenophenols. So far only the diselenides of anthraquinone and their phenols are recognized remedies(36). TINCTORIAL REVIEW Many of the seleno organic compounds are colored, while the corresponding sulphur derivatives are colorless. HC-CH HC-CH \|\| \|\| \|\| \|\| HC CH HC CH \ / \ / O S Furane, colorless Thiophene, colorless liquid liquid HC--CH HC--CH \|\| \|\| \|\| \|\| HC CH HC CH \ / \ / NH Se Pyrrol, colorless liq. Selenophene, yellow liq. but turns brownish in air after repeated extraction[B] This brings selenophene more akin to pyrrole than thiophene, but the group -NH- in the molecule of pyrrole is an auxochrome. The selenium atom in a cyclic compound also acts like an auxochrome. Selenoantipyrine(37), C₆H₅ N / \ CH₃N CSe \| \| CH₃C===CH forms pure yellow crystals from alcohol, while the corresponding compounds of oxygen and sulphur are colorless. Similarly, the 2-methyl-4-selenoquinazolone is deep brown in color, while the thio compound, prepared by Bogert and Hand(38) is light brown or yellow and the corresponding oxygen compound is colorless or nearly so. Diethyl selenide (C₂H₅)₂Se, is a yellowish heavy oil of unpleasant odor. It combines readily with chlorine to form a chloride (C₂H₅)₂SeCl₂, and the latter is oxidized by nitric acid to form an oxide (C₂H₅)₂SeO,(39). Diethyl sulphide is a colorless syrupy liquid, as well as diethyl amine and diethyl ether. The gradation of color is quite pronounced in the case of selenonaphthene quinone(40). CO CO CO CO /\ / \ /\ / \ /\ / \ /\ / \ \| \| CO \| \| CO \| \| CO \| \| CO \/ \ / \/ \ / \/ \ / \/ \ / O S NH Se It would be most natural to conclude that the chromophore :CS is more powerful than :CO, and that :CSe is most powerful of all, as shown in our study of quinazoline compounds. It would equally follow that :S is a more powerful color-forming radical in a cyclic compound than that of :O; and :NH than that of :S; and :Se again most powerful of the whole series. Lesser and Weiss(41) in their research on selenoindigo stated that the selenium dyestuff, on account of its greater molecular weight than sulphur, shows a deeper blue. This hypothesis meets a difficulty in the case of coumorandione, thionaphthenequinone and isatin series, where the -NH- radical has an atomic weight of 15, and -S- 32, and showed the reversed order of color. This seems to be the case in the selenophene series also. Therefore this theory is not without exceptions. The diselenides present a very interesting study also. Methyl disulphide is colorless, but methyldiselenide(42) is a reddish yellow liquid. Methyl disulphide only becomes yellow when it is treated with chlorine, and in such cases (CH₃)₂S₂Cl₂ is formed(43), in yellow rhombic crystals. Ethyldisulphide is colorless: ethyl- disulphidedichloride is a faint yellow oil(44). But the corresponding ethyldiselenide is a red liquid(45). Phenyl disulphide is colorless, and phenyldisulphide dibromide is of mother-of-pearl appearance, and practically colorless(46), while phenyl diselenide forms pure yellow needles(47), and phenyldiselenide dibromide orange red ones. While phenyldisulphide is colorless, when an auxochrome group is added, such as NH₂, the compound is colored. This is the case with o-diaminodiphenyldisulphide(48) which is yellow both in solution and in crystalline form. In other words, an auxochrome in addition to the chromophore group transforms a colorless chromogen into a colored one. Therefore groups like -S.S- and -Se.Se- are chromophores in the same sense as -N:N-. This is in agreement with the chromophore ideas of Hugo Kaufmann. The -Se.Se- is a more powerful chromophore than -S.S-. This brings one directly to the inquiry as to why 2-phenylbenzo- selenazole, which contains a :Se radical, should be colorless; and that even 6-nitro-2-phenylselenazole, with the addition of a chromophore NO₂, should be only faintly colored. The benzothiazoles, their isomers and derivatives are mostly colorless, and similar causes are probably responsible in the case of the phenylbenzoselenazole, for its lack of color. But when this selenazole is combined with another chromophore, for example an azomethine grouping, the result is a more positively colored compound (in this case benzalaminoselenazole), the crystals being yellow. The corresponding thiazole derivative is light colored. The tinctorial value of the selenium derivative is further evidenced by the ease with which it forms azo dyes and the deep colors of the latter. This was observed when 6-amino-2-phenylbenzoselenazole was diazotized and coupled with B-naphthol, salicylic acid, etc. The corresponding aminothiazole has been considered difficult to diazotize, on account of its insolubility in hydrochloric acid, cold or hot, but the aminoselenazole dissolves readily and completely, the coupling is almost instantaneous, and the dyes obtained are mostly red and of metallic lustre. In view of the stability of benzoselenazoles toward hot concentrated acids (with the exception of nitric, when nitration ensues) and alkalis, these dyes may prove of some commercial interest. The azole dyes of the benzoselenazole have been exposed to light for weeks, and also exposed to acids and alkalis, and have been found to be quite fast. EXPERIMENTAL Preparation of 2-methyl-4-selenoquinazolone Busch prepared quinazolines by the action of o-amino or o-nitro benzylamine with phosgene, and thioquinazolines with carbon disulphide(51): CH₂NH₂ CH₂-NH / / \| C₆H₄ + COCl₂ = C₆H₄ \| + 2HCl \ \ \| NH₂ NH--CO CH₂NHC₆H₅ CH₂-NC₆H₅ / / \| C₆H₄ + CS₂ = C₆H₄ \| + H₂S \ \ \| NH₂ NH--CS Accordingly the same reaction was tried with o-nitrobenzylamine, prepared by the method of Lellmann and Stickel(50), using carbon diselenide(51). The reaction seemed to work, but the mixture formed was difficult to extract and it appeared that other reactions took place at the same time, due to the impurity of the carbon diselenide, as the latter has never been prepared in the pure state. Another method, which is equally attractive because of its simplicity, is that of Gabriel and Stelzner(52), CHO CH=N / NH₂ / \| H₂O C₆H₄ + \| = C₆H₄ \| + \ H₂N-CO \ \| NH₃ NH₂ NH-CO In accordance with the above reaction o-aminobenzaldehyde should work with equal ease with selenocarbamide, but the initial materials were not available. The reaction which was used successfully was that of Bogert, Breneman and Hand(53), NH₂ NHCOR N=CR / / / \| C₆H₄ + (RCO)₂O → C₆H₄ → C₆H₄ \| \ \ \ \| CSNH₂ CS-NH₂ CS-NH ↑ ↑ or H₂S H₂S N=CR / \| + + C₆H₄ \| \ \| NH₂ NHCOR C=N / / \| C₆H₄ + (RCO)₂O → C₆H₄ SH \ \ CN CN The hydrogen selenide used in the reaction was prepared from FeSe by the action of hydrochloric acid, or by heating paraffin and selenium, in the proportion of four to one respectively, at 335° to 350°C(54). The selenoquinazoline was prepared from anthranilic nitrile by the following methods--the anthranilic nitrile being prepared from o-nitraniline(57), (a) 20 grams of acetyl-anthranilic nitrile was dissolved in absolute alcohol, and dry hydrogen selenide and dry ammonia passed into the solution for three hours. The quinazoline crystallized out gradually on cooling was filtered out and recrystallized from dilute alcohol. The yield was about ten per cent. (b) 10 grams of acetyl-anthranilic nitrile was heated in a sealed tube at 110° with alcohol saturated at zero degrees with dry hydrogen selenide and dry ammonia. After five hours, the tube was taken out and the quinazoline crystallized out on cooling. Yield was about sixteen per cent. As hydrogen selenide was somewhat unstable and did not dissolve freely in alcohol, freshly prepared sodium selenide was used in the following method and was found to be more satisfactory. It was prepared from sodium hydroxide in absolute alcohol by passing dry hydrogen selenide into the solution for about three hours. In the beginning and end of the reaction, nitrogen was used to exclude the oxygen of the air. The selenide was collected and dried in an atmosphere of nitrogen, and then in a vacuum, in presence of phosphorus pentoxide. When thus prepared, sodium selenide was colorless, but on exposure to air it turns reddish and finally dark colored. The C. P. selenide on the market was black and was found to be entirely useless. (c) 20 grams of anthranilic nitrile and fifty grams of sodium selenide were mixed and heated in a distilling flask in an atmosphere of nitrogen, and forty grams of acetic anhydride dropped into the flask very slowly. The temperature was kept at 115° for half an hour and then raised to distill off the acetic acid formed in the reaction, as the condensation hardly went to completion in the presence of any trace of acetic acid. The whole process took an hour and a half. The flask was removed from the oil bath and, after cooling, dilute alkali was run in, in successive portions, to dissolve out the quinazoline. Into the clear alkaline extracts carbon dioxide was bubbled for an hour, and common salt then added. The precipitate was recrystallized several times from twenty-five per cent. alcohol. The yield was from twenty to twenty-five per cent. (d) 10 grams of anthranilic nitrile, twenty grams of acetic anhydride, and twenty-five grams of sodium selenide were mixed in a sealed tube and heated together for three hours and a half at 110°-115°. The condensation product was crystalline when the tube was cooled to room temperature. The contents of the tube were extracted with dilute alkali as before, filtered, precipitated by carbon dioxide, and recrystallized from dilute alcohol. The yield was not over twenty per cent. (e) An attempt was made to make o-aminobenzoselenamide, and from the latter, by treatment with acetic anhydride, to form the quinazoline, but the yield of the amide was too small to carry the reaction further. The substance prepared by the above methods crystallizes from dilute alcohol in needles or prisms of dark brown color. It melts at 213.5° (corr.). It dissolves readily in hot alcohol but on concentration sometimes forms a sticky mass with a peculiar but not unpleasant odor. It dissolves readily in alkalis and is slightly soluble in hot benzene and chloroform, but insoluble in hot water. Crystals purified from (a) were analyzed and gave the following results: Calculated for Found C₉H₈N₂Se I II Carbon 48.38% 48.45% 48.62% Hydrogen 3.61 3.82 3.52 Nitrogen 12.55 12.51 12.66 Selenium 35.46 35.60 35.42 The crystals on standing in the presence of air and light decomposed with separation of finely divided selenium and methyl quinazolone. Analysis of Selenium Organic Compounds In the quantitative determination of selenium in quinazoline the method adapted by Becker and Meyer was found to be quite satisfactory(56). Other methods are listed in the bibliography(57). In the ultimate analysis of carbon and hydrogen, the ordinary absolute method was followed with the use of copper oxide, lead chromate, and lead peroxide in the tube. In the determination of nitrogen the ordinary absolute method was also followed excepting that a considerable quantity of specially prepared lead chromate powder was mixed with the sample in a number six porcelain boat. This was found to be desirable when the dinitroselenazole was burned. Selenium dioxide, which is a solid, seems to be formed in the tube and carried away by the current of carbon dioxide with some difficulty. In such a case the analysis usually took four hours after the combustion had actually started. In the carbon and hydrogen determination selenium dioxide was easily absorbed in the presence of oxygen gas. Preparation of 2-Phenylbenzoselenazole The first method employed was a modification of the method described by Fromm and Martin(58). Method (b) is an adaptation of the method for preparing benzothiazoles. (a) Twenty grams of benzanilide was mixed in a pyrex flask with 160 grams of selenium dust and the flask placed in a nitrate bath under an air condenser. After heating for an hour at 220°C., the temperature was raised to 250°C., and kept at 250°-280°C. for sixteen hours. The dark mass was extracted with hot concentrated HCl, the acid extracts filtered through glass wool using a hot water funnel. The combined extracts were poured into a large volume of water when the selenazole precipitated out immediately; it was recrystallized from alcohol. In some cases it was necessary to dissolve in hot HCl again and to recrystallize. The yield was twelve per cent. The above method has the disadvantage that water is formed in the reaction and this in turn reacts upon benzanilid at the higher temperature necessary (as selenium only melts at 217°C.), decomposing the benzanilid into aniline and benzoic acid. NHCOC₆H₅ N / / \\ C₆H₄ + Se = C₆H₄ C-C₆H₅ + H₂O \ \ / H Se NHCOC₆H₅ NH₂ / / C₆H₄ + HOH = C₆H₄ + HOOC-C₆H₅ \ \ H H Furthermore benzanilid boils at 160°C. and at such high temperatures as 250°C. and over some of it is apt to be driven off. (b) 106 grams of benzaldehyde were heated with 93 grams of redistilled aniline at 120°C., for two hours or until the solution was clear. The clear benzalaniline was then poured into 160 grams of selenium dust in a pyrex flask on a sand bath, the flask being connected with an air condenser as before. In order to distribute the flame to better advantage over the bath, an air space was made between the Meker burner and the bath by introducing a wire gauze. Hydrogen selenide was evolved freely. Complete reaction took three days. The extraction and recrystallization were the same as in the former case. The yield was sixty per cent. The selenazole crystallizes in colorless long needles, melting at 117.5°C. (corr.) Fromm and Martin(58) gave the melting point as 117°C. It is insoluble in water, and in the following solvents it is lightly soluble in the cold, more easily hot: ether, methyl alcohol, acetone, acetic acid, acetic anhydride, chloroform, and nitrobenzene. It is difficultly soluble in ethyl alcohol, ethyl acetate, and carbon tetrachloride, in the cold, but easily soluble hot. Mononitro Derivative The mononitro derivative of the selenazole, 6-nitro-2-phenylbenzo- selenazole, was prepared by nitration with nitric acid at a low temperature: Twenty-five grams of the selenazole were dissolved in 150 grams of concentrated sulphuric acid, keeping the temperature below the room temperature until complete solution took place. It was then cooled on a freezing mixture and a mixture of sulphuric and nitric acids (previously prepared and cooled by mixing 9.5 grams of nitric and fifteen grams of sulphuric acids) slowly dropped into it in the course of half an hour, using mechanical stirring for four hours. The solution was then poured into two liters of water (ice water), filtered, dried, and recrystallized from acetic acid, and alcohol with the help of animal charcoal. The yield was 95 per cent. This nitro compound crystallizes in flattened needles of a light yellow color. It melts at 202.4°C. (corr.). It is very insoluble in water; but soluble in hot acetic acid, acetic anhydride, nitrobenzene, nitrotoluene, toluene, benzene, alcohol, and difficultly soluble when cold. The crystals were analyzed and gave the following results, Calculated for Found C₁₃H₈N₂O₂Se I II Nitrogen 9.24% 9.36% 9.48% Monoamino Derivative The conversion of mononitro compound to 6-amino-2-phenylbenzoselenazole was accomplished by the action of tin and hydrochloric acid as follows: 30.3 grams of nitro compound were mixed with 42 grams of twenty mesh tin in a liter flask, immersing the latter in cold water. 175 cc. of conc. HCl were slowly added to the flask. In some cases it was necessary to apply initial heating but when once the reaction started it took place rapidly. After the effervescence had abated, the flask was heated over a free flame, under a return condenser, for two hours. The solution usually turned to a pasty mass, due to the formation of a tin double salt. The mixture was dissolved in a large volume of water and heated on a water-bath, the precipitate filtered out, washed, and preserved. The clear filtrate was treated with concentrated alkali, in excess, the separated amine collected, washed with water, dried and recrystallized from alcohol, using bone-black. The precipitate set aside was treated with strong alkali, the insoluble residue washed, recrystallized, and added to the main product. The yield was 75 per cent. This amine crystallizes from alcohol in fine yellowish needles, melting at 201.2°-202.3°C (corr.). It is insoluble in water and ether, difficultly soluble in the hot; and fairly soluble in aniline. A pure sample was analyzed and gave the following results: Calculated for Found C₁₃H₁₀N₂Se I II Nitrogen 10.25% 10.34% 10.42% Carbon 57.18 57.17 57.00 Hydrogen 3.69 3.79 3.85 Decomposition of Monoamino Derivative Five grams of the monoamino compound were mixed with powdered KOH, heated together until the mixture just melted, and maintained in that state for a few minutes. When the latter had cooled down to room temperature, cold water was poured over the mixture. The filtered solution was acidified until no further precipitate was formed. The precipitate was collected and recrystallized from water, m.p. 121°C. One gram of this solid was placed in a test tube, provided with a cork and a delivery tube, and heated with soda lime; a liquid with the smell of benzene was collected in another test tube cooled with water. When this liquid was treated with a few drops of nitric acid mixture the smell of nitrobenzene was given off. A gram of the crystals was heated with concentrated sulphuric acid and alcohol when the odor of ethyl benzoate was noted. Monacetyl Derivative Five grams of the monoamino selenazole were heated on a water-bath with 10 cc. of acetic anhydride until the solution was clear, which took about two hours. 100 cc. of water were poured into the mixture, which was then neutralized with dilute ammonium hydroxide. The precipitate was filtered, decolorized by animal charcoal, and recrystallized from dilute alcohol. The acetyl compound, 6-acetamino-2-phenylbenzoselenazole, forms colorless crystals, melting at 188.1°-.7°C. (corr.). It is insoluble in ether, benzene, carbon disulphide; slightly soluble in toluene; soluble in alcohol, ethyl acetate, amyl acetate, acetone, and acetic acid. A pure sample was analyzed and gave the following result, Calculated for C₁₅H₁₂N₂SeO Found Nitrogen 8.88% 8.92% 8.68% Monobenzylidene Derivative Five grams of the monoamino compound were dissolved in 200 cc. absolute alcohol with the addition of 3 cc. of benzaldehyde and the clear solution was boiled on a water-bath, with a return condenser, for two hours. After the solution was boneblacked, the yellow precipitate was recrystallized from carbon disulphide. The yield was 90 per cent. It crystallizes in yellow plates, melting at 156.7°-157.6°C., soluble in benzene, ether, ethyl alcohol, carbontetrachloride, acetone, but difficultly soluble in ligroin. An analysis of the crystals showed the following result, Calculated for C₂₀H₁₄N₂Se Found Nitrogen 7.75% 7.92% 7.68% An Azo Dye Five and four tenth grams of the monoamino compound were dissolved in hot conc. HCl, cooled in ice, and diazotized with sodium nitrite solution, until starch iodide paper showed excess nitrous acid. The diazotization was performed in ice, with mechanical stirring, and required about an hour. The diazo solution was poured into a solution of 3 grams B-naphthol in 8 grams of NaOH and 60 cc. of water, while gradually stirring. A very deep red solution formed. This was acidified with excess HCl, salted out by NaCl, and crystallized from aniline-alcohol mixture. In the pure state, it is a deep red powder, with a metallic lustre when rubbed, melting at 284.2°C. An analysis showed the following result, Calculated for C₂₃H₁₅N₃OSe Found Nitrogen 9.81% 9.75% Dinitro Derivative The nitration for the production of dinitro derivative was at first carried out under the same conditions as in the preparation of mononitro compound and after the latter was formed more nitric acid mixture was added with the addition of heat: conc. sulphuric acid, keeping it below room temperature. It was then cooled in a freezing mixture and half the volume of a nitric acid mixture (prepared and cooled by mixing 19 grams of nitric and 30 grams of sulphuric acids) was introduced very slowly to the selenazole solution through a dropping funnel, maintaining at this temperature for two hours (using mechanical stirring). The remaining half of the nitric acid mixture was then slowly introduced and the flask was heated on a water-bath for two hours. The solution was poured into two liters of water, the precipitate filtered off, dried and recrystallized several times from acetic acid. The yield was 80 per cent. This dinitro compound crystallizes in fine yellow needles, m. p., 246.8°C. (corr.), very insoluble in water, but soluble in hot acetic acid, acetic anhydride, nitrobenzene, nitrotoluene, ethyl alcohol, and difficultly soluble cold. It was analyzed and the following results were found, Calculated for Found C₁₃H₇N₃O₄Se I II Nitrogen 12.07% 12.30% 12.12% Diamino Derivative The conversion of the dinitro to diamino derivative was accomplished in the same manner as the reduction of the mononitro derivative excepting that twice as much tin and HCl were used. This diamino compound crystallizes in yellowish glistening needles from alcohol and pyridine; m. p., 269°-270.5°C.; was analyzed and gave the following results, Calculated for Found C₁₃H₁₁N₃Se I II Nitrogen 14.6% 14.4 14.7 Diacetyl and Dibenzylidene Derivatives The diacetyl and dibenzylidene compounds were also prepared from these diamino derivatives. The former crystallizes in cubes from dilute alcohol; m. p., 307°C (Corr.) and the latter in beautiful yellow plates from carbon disulphide, m. p., 195°-196°C. (Corr.). An analysis of these two compounds showed the following results, Calc. for Calc. for Found C₁₇H₁₅N₃O₂Se C₂₇H₁₉N₃Se I II Nitrogen 9.05% 11.21% 9.21% 11.43% Dyeing with Azo Dyes Both the monoamino and the diamino derivatives form intensely colored dyes when diazotized and coupled with phenols and aromatic amines. The dyes formed are fast to light. In the following table silk is given to represent the fabrics used. Wool and cotton were dyed similar shades, though with slight variation. Each silk sample was dyed in acid or alkaline baths as indicated and each bath contained 0.01 gram in twenty cc. solution: Diazo. On Diazo. On Coupler monoamine silk diamine silk Phenol deep red v. light (alk) yellow (alk) yellow deep red Dimethylaniline orange light orange-red yellow (acid) yellow (acid) P-nitraniline light brownish grayish brown (acid) brown (acid) P-toluidine light brownish brownish brown (acid) (acid) Pyrogallic dark grayish dark grayish acid brown brown (acid) (alk) Salicylic reddish light red brown acid (alk) brown (alk) B-naphthol deep red pink deep red red (alk) (alk) Sulphanilic light brownish brown brown acid brown (alk) (alk) A-naphthylamine light brownish yellow yellow brown (acid) (acid) Resorcinol purple red dark deep red (alk) purple (alk) BIBLIOGRAPHY 1. Berzelius, Annales de Physique et Chimie (2) 9, 239, 356 (1818). 2. Gmelin-Kraut, “Handbuch der Anorg. Chemie” I (1) 705-804; Roscoe and Schorlemmer, “Treatise on Chemistry” I, 467-82 (1920); Browning, “Introduction to the Rarer Elements,” 144-52 (1917). 3. Victor Lenher, J. Ind. Eng. Chem., 12, 597 (1920). 4. 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Chim. ital., 39, II, 527, (1909); C-B., (1910) I, 837. 30. D. R. P., 264,139. 31. O. Hinsberg, Ber., 22, 862, 2895 (1889); D. R. P., 261,412. 32. J. prakt. Chem., (1904) II, 69, 509. 33. E. Abderhalden, Hand. Biol. Chem., III, 2, 954. 34. Hanzlik & Tarr, Am. Univ. Ezpt. Sta., J. Pharmacol, 14, 221-8 (1919). 35. Hochst, D. R. P., 299,510. 36. D. R. P., 264,940; 264,961. 37. A. Michaelis & M. Stein, Ann., 320, 32 (1902). 38. Bogert & Hand, J. Am. Chem. Soc., 25, 377 (1902). 39. B. Bathke, Ann., 152, 210 (1869); Ann., 185, 331; Richter, Organische Chemie, I, 166. 40. Lesser & Schoeller, Ber., 47, 2293 (1914). 41. Lesser & Weiss, Ber., 45, 1835 (1912); 46, 2653, (1913). 42. Wohler & Dean, Ann., 97, 5 (1856); B. Rathke, Ann., 152, 211 (1869). 43. Cahours, Ann., 61, 92, (1847); 92, 356. 44. H. Klinger, Ber., 32, 2195, (1899); Ann., 119, 91; 121, 108. 45. C. A. Joy, Ann., 86, 35, (1853); B. Rathke, Ann., 152, 212, 219 (1869). 46. Wheeler, Z. Chem., (1867) 436. 47. Krafft & Lyons, Ber., 27, 1762 (1894); A. Ch., (6), 20, 228. 48. K. A. Hoffmann, Ber., 27, 2809 (1894). 49. M. Busch, Ber., 25, 2853, (1892). 50. Lellmann & Stickel, Ber., 19, 1605 (1886). 51. B. Rathke, Ann., 152, 201 (1869). 52. Gabriel & Stelzner, Ber., 29, 1313 (1896). 53. Bogert, Breneman, & Hand, J. Am. Chem. Soc., 25, 373 (1903). 54. Am. Chem. Abs., 3, 870 (1903); Bull. Belg. Soc. Chem., 23, 9-11. 55. Bogert & Hand, J. Am. Chem. Soc., 24, 1035, (1902). 56. Becker & Meyer, Ber. 37, 2551 (1914). 57. H. Bauer, Ber. 48, 507 (1915); Lyons & Shinn, J. Am. Chem. Soc. 1902: 1092; Fritz von Konek & O. Schleifer, Ber. 51, 850 (1918); A. Michaelis, Ber. 30, 2827 (1897); Ber. 48, 873 (1915); H. Frerichs, Arch. Pharm. 1902: 240, 656. 58. Fromm & Martin, Ann., 401, 178 (1913). VITA Yü-Gwan Chen was born in Nanking, China, March 8, 1893. After graduation from college in 1915, he further studied Chinese classics, 1915-16. He entered Case School of Applied Science, Cleveland, Ohio, as a special student in the Department of Chemistry, 1916-17. He registered at Columbia University to pursue graduate work in chemistry under the Faculty of Pure Science; and was awarded the degree of Master of Arts in 1918. From September 1919 to June 1922, he has been pursuing research in organic chemistry in the research laboratories of Havemeyer Hall, Columbia University. FOOTNOTES: [A] Not a new compound but prepared by a different method. [B] Note--dimethyl selenophene, however, is colorless. Transcriber's notes: The diagram of 3-(p-phenylarsonic)-aminoselenazine, labelled (II), has been adjusted to make its structure clearer. The "l" in "2HCl" in the first equation under "Preparation of 2-methyl-4-selenoquinazolone" was missing in the original. The following is a list of changes made to the original. The first line is the original line, the second the corrected one. selnoquinazolone prepared in the course of this research selenoquinazolone prepared in the course of this research on four different strains of mouse carcenoma and one strain on four different strains of mouse carcinoma and one strain in consequence of its smell I so completely loss my sense of smell in consequence of its smell I so completely lost my sense of smell of the phenazine, oxasine, thiazine, acridine series show of the phenazine, oxazine, thiazine, acridine series show and Se again most powerful of the whole series. and :Se again most powerful of the whole series. simplicity, is that of Babriel and Stelzner(52), simplicity, is that of Gabriel and Stelzner(52), on cooling was filtered out and recrystalized from dilute alcohol. on cooling was filtered out and recrystallized from dilute alcohol. It was prepared from Sodium hydroxide in absolute alcohol It was prepared from sodium hydroxide in absolute alcohol a sealed tube at 110° with alcohol saturated at zero degree with a sealed tube at 110° with alcohol saturated at zero degrees with took an hour and half. The flask was removed from the oil took an hour and a half. The flask was removed from the oil The precipitrate was recrystallized several times The precipitate was recrystallized several times (e) An attempt was made to make o-aminobenzselenamide, (e) An attempt was made to make o-aminobenzoselenamide, It dissolves readily in alkalies and is slightly soluble It dissolves readily in alkalis and is slightly soluble This was found to be desirable when the dinitroselezazole was burned. This was found to be desirable when the dinitroselenazole was burned. into a large volume of water when the selenozole precipitated out into a large volume of water when the selenazole precipitated out it was necessary to dissolve in hot HCl again and to recrystalize. it was necessary to dissolve in hot HCl again and to recrystallize. (b) 106 grams of benaldehyde were heated with 93 grams of (b) 106 grams of benzaldehyde were heated with 93 grams of It is difficulty soluble in ethyl alcohol, ethyl acetate, and It is difficultly soluble in ethyl alcohol, ethyl acetate, and toluene, benzene, alcohol, and difficulty soluble when cold. toluene, benzene, alcohol, and difficultly soluble when cold. from alcohol in fine yellowish needles, melting at 201.2°202.3°C from alcohol in fine yellowish needles, melting at 201.2°-202.3°C carbontetrachloride, acetone, but difficulty soluble in ligroin. carbontetrachloride, acetone, but difficultly soluble in ligroin. 19 grams of nitric and 30 grams of sulphuric acids was introduced 19 grams of nitric and 30 grams of sulphuric acids) was introduced in the same manner as the reduction of mononitro derivative in the same manner as the reduction of the mononitro derivative This diamino compound crystalizes in yellowish glistening needles This diamino compound crystallizes in yellowish glistening needles compounds were also prepared from this diamino derivatives. compounds were also prepared from these diamino derivatives. The former crystalizes in cubes from dilute alcohol; The former crystallizes in cubes from dilute alcohol;	16,754	common-pile/project_gutenberg_filtered	46714	project gutenberg	project_gutenberg-dolma-0008.json.gz:324	https://www.gutenberg.org/files/46714/46714-0.txt
P5WTsze7Ph586-mJ	Technology and the Curriculum: Summer 2018	Assistive Technologies 24 Dawn Rose Dawn Rose<EMAIL_ADDRESS>University of Ontario Institute of Technology (UOIT) ABSTRACT The 2012 Canadian Survey on Disability indicated the prevalence of learning disabilities at 2.3% with 98% of those people indicating their disability had a negative impact on their education (Statistics Canada, 2012). As diversity and learner variability increase in schools, the prevalence of students with disabilities may similarly increase leading to the necessity for more students being accommodated or employing Assistive Technology (AT). According to the Learning Disabilities Association of Ontario (2015), “Living with a learning disability can have an ongoing impact on friendships, school, work, self-esteem and daily life”. This chapter will examine the relationship between AT and Universal Design for Learning (UDL) for removing barriers to instruction and learning for people with reading-related disabilities. It provides a literature review, the results of which indicate enhanced accessibility and inclusivity through the use of AT and UDL increase student performance. It examines the available features of a specific educational and assistive technology by Freedom Scientific (2018), Jobs Access With Speech (JAWS®) screen reader technology, and the requirements for integrating this technology into the curriculum. Ultimately it recommends AT in tandem with UDL to support diversity and inclusion, and to fulfil the goal of UDL to enhance learning for all students” (Quaglia, 2015, p. 1), which, by extension, may reduce the negative impact of disability on students’ lives. Keywords: Accessibility, Assistive Technology, barrier, curriculum, diversity, education, inclusion, JAWS®, learning disability, screen reader, student performance, technology, Universal Design for Learning INTRODUCTION In 2012 Statistics Canada conducted the Canadian Survey on Disability and determined that of the Canadian population fifteen years of age or older, 13.7% reported having a disability that limited their daily activities. This study indicated the prevalence of learning disabilities was 2.3%, affecting approximately 622,300 people, 98% of whom said their disability had a direct negative impact on their education. People with learning disabilities are 20% less likely than those without a disability to have completed high school, and 26% less likely to have completed trade school or college (Statistics Canada, 2012). The Learning Disabilities Association of Canada (2002) has defined Learning Disabilities as “a number of disorders which may affect the acquisition, organization, retention, understanding or use of verbal or nonverbal information”. According to the Learning Disabilities Association of Ontario (2015), “Living with a learning disability can have an ongoing impact on friendships, school, work, self-esteem and daily life”. Ensuring equal access to opportunities for persons with disabilities can have a positive impact on their lives. This chapter will examine the relationship between Assistive Technologies (AT) and Universal Design for Learning (UDL) for removing barriers to instruction and learning, and the implications to curriculum design when incorporating AT to support students with reading-related learning disabilities. BACKGROUND INFORMATION The 2016 Census indicates 21.9% of Canada’s population was born outside of Canada (Statistics Canada, 2017). With the increasing number of people entering Canada through the immigration process and the diversity of our population increasing, diversity in classrooms similarly increases as does learner variability, including the number of students with disabilities. These factors put increasing pressure on schools and educators due to the differing needs of diverse populations. The goal of UDL is to “enhance learning for all students” (Quaglia, 2015, p. 1). AT and UDL compliment each other such that advances in one leads to advances in the other (Rose, Hasselbring, Stahl, & Zabala, 2005). Section 1 of the Ontario Human Rights Code (2012) guarantees the “right to equal treatment with respect to services, without discrimination because of disability”. Under the Human Rights Code, the definition of disability includes a learning disability. Employing AT is one way to prevent discrimination in education. A review of existing AT interventions conducted by Perlmutter, McGregor, and Gordon (2017), determined AT supports can result in positive outcomes for adolescents and adults with learning disabilities, but supports must be customized for each individual. While AT focuses on the individual, UDL focuses on the curriculum and reducing barriers. In a learning context, AT is defined as “technology that increases, improves, or maintains the functional capabilities of students with disabilities” (Rose et al., 2005, p. 508). Rogers-Shaw, Char-Chellman, and Choi (2017) describe UDL as “a framework for the teaching-learning transaction that conceptualized knowledge through learner-centered foci emphasizing accessibility, collaboration and community” (p. 20). LITERATURE REVIEW Assistive Technology and Universal Design for Learning: Two Sides of the Same Coin. Technology continues to evolve and transform learning and education for students with disabilities. In their article discussing the similarities and differences between AT and UDL, Rose et al., (2005) conclude universal designs benefit disabled and able-bodied persons alike, and that “Assistive technologies make universal designs more effective” (p. 510). Assistive Technology: Empowering Students with Learning Disabilities. Some learning disabilities interfere with reading comprehension because the students have difficulty decoding words. The review by Forgrave (2002) concluded speech synthesis technology, when used to read unfamiliar text to students, can dramatically improve students’ reading speed and comprehension. This improvement may motivate students to read independently and therefore improve their reading success. Implementing Assistive Technologies: A Study on Co-Learning in the Canadian Elementary School Context. A study by White and Robertson (2014) indicates text-to-speech technologies could benefit students by decreasing their dependence on others to read text to them. The authors further indicate if teachers are to routinely use AT in their classrooms, they require training in the use of the AT. As a result of their study the authors found, “All of the students in this study had difficulties with reading, but with assistive technologies which compensated, they were able to work at grade level” (p. 1274). Furthermore, the use of text-to-speech provided students with disabilities the opportunity to read the same books as their peers and to send emails to their friends, resulting in improvements in both motivation to read and reading comprehension. Supported eText: Effects of Text-to-Speech on Access and Achievement for High School Students with Disabilities. In the absence of individual accommodations, learning disabilities can be a barrier to students accessing the general curriculum. Authors Izzo, Yurick, and McArrell (2009) investigated the use of eText to support high school students and found “learned helplessness is prevalent among special education students” (p. 3), who, when taking quizzes randomly clicked answers knowing they were going to fail the quiz. However, when using text-to-speech AT, all students’ unit quiz scores improved, and most students’ reading comprehension improved. Universal Design for Learning. Rogers-Shaw et al., (2017) believe that leveraging technology in universal design could lead to greater inclusivity, however, they caution the simple application of technology is insufficient to achieve this greater inclusivity if educators do not adopt the principles of UDL to more effectively meet the needs of all learners. Universal Design for Learning: Enhancing Achievement and Employment of STEM Students with Disabilities. Advances in computer technology have increased, and now students have multiple means of accessing course content when course design is in keeping with the principles of UDL, and these “universally designed devices can reduce the need for formal accommodations for STEM students with disabilities” (Izzo & Bauer, 2013, p. 19). Izzo and Bauer (2013) indicate “when accessible technology and instruction are provided using UDL principles…many students benefit with increased achievement. Learning through universally designed and accessible technology is essential for students with disabilities who, without access, would not gain the skills needed to complete their degrees” (p. 17). APPLICATIONS AT can form part of formal accommodations for persons with disabilities to increase accessibility, ensure equal access to educational opportunities, and support inclusive classrooms; however, AT, when employed by disabled students only, can make the disability more conspicuous, which could discourage use of the AT by disabled students and therefore be a barrier to learning. A similarity between AT and UDL is they both rely on technology to enhance learning for students with disabilities. The main difference is that AT is designed to help individual students compensate for barriers in the curriculum, whereas UDL is about leveraging technology in curriculum design to prevent or reduce barriers. AT increases the efficacy of universal designs. Universal designs are “not unique or personal, but universal and inclusive, accommodating diversity” (Rose et al., 2005, p. 509). Because the designs are universal they benefit a wider range of students. UDL requires the curriculum and the basic components of pedagogy and classroom processes to be accessible. According to Rose and Meyer (2002), the UDL framework’s principles emphasize three aspects of pedagogy, the means of representing information, expression of knowledge, and engagement in learning. Students with reading-related disabilities may have difficulty with all three aspects, particularly engaging in learning. EDUCATIONAL TECHNOLOGY – JOB ACCESS WITH SPEECH (JAWS®) Students with reading disabilities encounter barriers because the majority of content is text-based and the majority of assessments require writing. Looking at this from a UDL perspective reveals the problem is not the individual but rather the text-reliant curriculum. From an AT perspective, the screen reader technology JAWS® can enhance the functional abilities of students with reading disabilities. JAWS® features include but are not limited to: Optical character recognition software to work with a scanner; supports PEARL Camera (Freedom Scientific, 2018) scanning and reading system; built-in DAISY Player (Daisy Consortium, 2018) for people with print disabilities; compatible with several screen magnifiers; supports MathML (Wolfram, 2018); a text analyzer; JAWS® Tandem (Freedom Scientific, 2018) to access another computer running JAWS®; drivers for popular Braille displays, voiceover in 30 languages; it is supported by Blackboard (Blackboard Inc., 2018) learning management system and by Zoom (Zoom Video Communications, Inc., 2018) conferencing software (Freedom Scientific, 2018). JAWS® screen reading software could support students with visual impairments or dyslexia, comprehension issues, and some physical disabilities. To incorporate JAWS® into the curriculum, all content and classroom tasks must be available on the Windows operating system. Staff and students would require training, and unless students were going to share computers each student would require their own workstation. Additionally, students may need a version of JAWS® for use at home to complete homework and projects outside of school hours. If the curriculum design included “universally designed media that offer diverse options for viewing and manipulating content and expressing knowledge…fewer students face barriers” (Rose et al., 2005, p. 510). A curriculum so designed could provide text-to-speech technology to support students with dyslexia, video or images to increase comprehension in students with language-based disabilities, descriptive video or captions for students who are blind or deaf, keyboard alternatives to support students with physical disabilities, and could enhance learning for many students (Rose & Meyer, 2002). Conclusions and Future Recommendations There are many dimensions of diversity represented in school settings. People are different and may require different supports to have equal access to educational opportunities. Ensuring equitable treatment means ensuring students get the supports they need to succeed, and research demonstrates the efficacy of AT, the provision of which is a means of providing these supports. However, supports or accommodations may not be required if the barrier, the cause of the inequity, is addressed, and UDL aims to do that through universally designed curricula. While the JAWS® screen reader technology does provide support to students with learning disabilities related to reading, which according to research reviewed in this chapter will enhance achievement for the majority of students who use it, the use of AT does not address the source of the inequity, the inflexible curricula. Furthermore, because the Windows Professional Edition of JAWS® is $1095, the cost may be a limiting factor in the use of the software as schools may be constrained in how many versions they can purchase; and, it is unlikely JAWS® will be available for use by all students, thereby singling out students with reading-related disabilities. Computer-based AT can support equal access to educational opportunities for students with disabilities, and UDL relies on technology to “enhance learning for all students” (Quaglia, 2015, p. 1). In order for UDL to be effective, AT is required. If, however, technologies were employed as instructional technologies in support of UDL rather than assistive technologies to ameliorate for barriers, they would become tools available to all students and therefore promote an inclusive learning environment (White & Robertson, 2015). As UDL becomes more pervasive and learning becomes more inclusive, the number of people living in Canada whose disability negative impacts their education should be inversely correlated to the increase in inclusive curriculum design. References Blackboard Inc. (2018). Blackboard Learn. [Learning Management System]. Retrieved from http://www.blackboard.com/learning-management-system/blackboard-learn.html DAISY Consortium. (2018). DAISY Digital Talking Book. [Web page] Retrieved from http://www.daisy.org/daisypedia/daisy-digital-talking-book Forgrave, K. E. (2002). Assistive technology: Empowering students with learning disabilities. The Clearing House: A Journal of Educational Strategies, Issues and Ideas, 75(3), 122-126. doi:10.1080/00098650209599250 Freedom Scientific. (2018). Blindness solutions: JAWS®. [Web page]. Retrieved from https://www.freedomscientific.com/Products/Blindness/JAWS Freedom Scientific. (2018). JAWS Tandem Quick Start Guide. [Web page]. Retrieved from https://www.freedomscientific.com/JAWSHq/JAWSTandemQuickStart Freedom Scientific. (2018). PEARL Portable Reading Camera. [Web page]. Retrieved from https://store.freedomscientific.com/products/pearl-portable-reading-camera Freedom Scientific, Inc. (2018). JAWS Headquarters. [Web page]. Retrieved from https://www.freedomscientific.com/JAWSHQ/JAWSHeadquarters01 Human Rights Code, R.S.O. 1990, c. H.19. (2012). Retrieved from https://www.ontario.ca/laws/statute/90h19?search=e%2Blaws Izzo, M. V., & Bauer, W. M. (2013). Universal design for learning: Enhancing achievement and employment of STEM students with disabilities. Universal Access in the Information Society, 14(1), 17-27. doi:10.1007/s10209-013-0332-1 Izzo, M. V., Yurick, A., & Mcarrell, B. (2009). Supported eText: Effects of text-to-speech on access and achievement for high school students with disabilities. Journal of Special Education Technology, 24(3), 9-20. doi:10.1177/016264340902400302 Learning Disabilities Association of Canada. (2002). Official Definition of Learning Disabilities. [Web page]. Retrieved from https://www.ldac-acta.ca/official-definition-of-learning-disabilities/ Learning Disabilities Association of Ontario. (2015). Working description of learning disabilities. [Web page]. Retrieved from http://www.ldao.ca/introduction-to-ldsadhd/what-are-lds/a-working-description-of-learning-disabilities/ Perelmutter, B., Mcgregor, K. K., & Gordon, K. R. (2017). Assistive technology interventions for adolescents and adults with learning disabilities: An evidence-based systematic review and meta-analysis. Computers & Education, 114, 139-163. doi:10.1016/j.compedu.2017.06.005 Quaglia, B. W. (2015). Planning for student variability: Universal design for learning in the music theory classroom and curriculum. Music Theory Online, 21(1), 1-21. doi:10.30535/mto.21.1.6 Rogers-Shaw, C., Carr-Chellman, D. J., & Choi, J. (2017). Universal design for learning: Guidelines for accessible online instruction. Adult Learning, 29(1), 20-31. doi:10.1177/1045159517735530 Rose, D. H., & Meyer, A. (2002). Teaching every student in the digital age: Universal design for learning. Alexandria, VA: Association for Supervision and Curriculum Development. Rose, D. H., Hasselbring, T. S., Stahl, S., & Zabala, J. (2005). Assistive technology and universal design for learning: Two sides of the same coin. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/similar?doi=<IP_ADDRESS>7.1325&type=cc Statistics Canada. (2012). Canadian Survey on Disability, 2012. {Web page}. Retrieved from https://www150.statcan.gc.ca/n1/en/catalogue/89-654-X Statistics Canada. (2017). Immigration and ethnocultural diversity: Key results from the 2016 Census. {Web page}. Retrieved from https://www150.statcan.gc.ca/n1/daily-quotidien/171025/dq171025b-eng.htm White, D. H., & Robertson, L. (2015). Implementing assistive technologies: A study on co-learning in the Canadian elementary school context. Computers in Human Behavior, 51, 1268-1275. doi:10.1016/j.chb.2014.12.003 Wolfram. (2018). Working with MathML-Wolfram Language Documentation. {Web page]. Retrieved from http://reference.wolfram.com/language/XML/tutorial/MathML.html Zoom Video Communications, Inc. (2018). Video Conferencing, Web Conferencing, Webinars, Screen Sharing. [Web page]. Retrieved from https://zoom.us/	3,230	common-pile/pressbooks_filtered	https://pressbooks.pub/techandcurriculum/chapter/assistive-tech-and-udl/	pressbooks	pressbooks-0000.json.gz:56710	https://pressbooks.pub/techandcurriculum/chapter/assistive-tech-and-udl/
1zUVOs6MDDcst9qD	Powerline Tech Prep Program Manual	7 Topic: Operating Voltages (30m) Instructions: - Cover the following content as a group (either reading out loud or independently) then give an opportunity to answer any questions. - Have students do the review questions independently, then take up answers. The electricity in any utility goes through many voltage changes. First, voltage is stepped up after generation to transmission voltages. After being transported to a more central location, the voltage is stepped down to distribution levels. Finally, through the use of distribution transformers, the voltage levels are further reduced to supply low voltages for customer use. In addition to the various voltages, we will look at some terms which tend to be confusing. First, we will explain some common terms, then identify some of the common voltages. Terms Some terms that are used have very similar meanings: phase and line are an example of this. We have all heard of a three-phase or single-phase power line. Phase voltage Is the voltage across one coil in a generator. Phase to Phase Voltage Is the voltage between any two lines in a three-phase system that produced three distinct and separate voltages (three-phase generator.) Line voltage Is also referred to as “line to line voltage” and is used to describe the voltage a power line can produce between two phases. Since a line with two conductors has the same line to line voltage as a line with three conductors, they can both be classified as having the same voltage. For example, a two- or three- phase lines can both be called 25kV lines. Line to Ground Voltage Describe the voltage a single-phase or single line conductor has to ground. For example, a single-phase rural line is rated at 14.4 kV to ground. Also, one phase of a 25kV line to ground can give 14.4 kV Voltages Through a Utility Previously, we have learned that voltage is raised to higher levels for transporting. These high voltages exist on transmission lines and are always interconnected in a “transmission grid system”. The three major transmission voltages used at this utility are: - 230,000 volts - 138,000 volts - 72,000 volts Three major distribution voltages are: - 25,000 volts - 14,400 volts - 4160 volts - 2400 volts Distribution and transmission lines are always designated according to their line-to-line voltage (voltage between phases or line values). Note: The only exception to this rule is the 14.4 kV rural line. It taps off the 25 kV line but can only supply 14.4 kV because it has no other phase to find reference with. The only other reference available is ground, so that is used. Once power is delivered to a customer’s site, it is lowered to the supply voltage the customer desires. This is done through a distribution transformer and delivered in “secondary” lines or services. Five Major Loads The loads which utilities supply are divided into five major types: - Farms - Residential – housing in towns and cities - Commercial – small business - Industrial – can be supplied by high voltage lines to their own substations - Streetlights Utilities make every effort to comply with the customer’s request, but if the transformers and metering needed to supply a given voltage do not exist, a different voltage will be supplied. The new standard is to avoid three-phase, three wire services in a favour of a three-phase, four-wire. Review Questions: Operating Voltages (30m) Line to line volts can refer to the voltage: - Between phases - Phase to ground - Phase to neutral - None of the above ( True / False ) Line to line voltage is a phase-to-phase voltage. A single-phase line can only supply: - Line to line voltage - Phase to phase voltage - Line to ground voltage - None of the above ( True / False ) A two-phase line has less supply voltage than a three-phase line. List the three transmission voltages List three voltages commonly used in distribution Transmission and distribution voltages are mainly classified by: - Line to ground volts - Line to line volts - Phase to ground volts - None of the above ( True / False ) A 14.4 kV line is rated by a phase to ground voltage Secondary lines are rated to their: - Line to ground voltage - Line to line voltage - Supply voltages - All of the above What are the five major types of load? Answer Key 1. a, 2. T, 3. c, 4. F, 5. 230 kV, 138 kV, 72kV, 6. 25kV, 4.16kV, 2.4kV, 7. b, 8. T, 9. a, 10. Farms, Residential, Commercial, Industrial, Streetlights	997	common-pile/pressbooks_filtered	https://pressbooks.pub/powerlinetechprep/chapter/operating-voltages/	pressbooks	pressbooks-0000.json.gz:97922	https://pressbooks.pub/powerlinetechprep/chapter/operating-voltages/
lrPRlEZw_N3VjRhj	Human Services Practicum	4.5 Conclusion Working with people from a variety of backgrounds and experiences can be one of the most rewarding and challenging parts of human service work. The profession has come a long way in understanding the importance of recognizing and respecting differences, but there is still a lot of work yet to be done. Your internship gives you the chance to explore your own views and biases and begin to develop the skills to work effectively across differences. These skills will be integral as you continue in your profession. Conclusion Licenses and Attributions “Conclusion” written by Yvonne M. Smith LCSW is licensed under CC BY 4.0. A credit class in which students apply theory to practice by using what you have learned in coursework in a real-world setting with a supervisor/mentor who is invested in your growth and development (often also referred to as fieldwork or practicum).	191	common-pile/pressbooks_filtered	https://openoregon.pressbooks.pub/hspracticum1e/chapter/oo4-5/	pressbooks	pressbooks-0000.json.gz:33901	https://openoregon.pressbooks.pub/hspracticum1e/chapter/oo4-5/
Y6435DIqL4rc4TY8	21.10: Checklist for Foley Catheter Insertion (Male)	21.10: Checklist for Foley Catheter Insertion (Male) Use the checklist below to review the steps for completion of “Foley Catheter Insertion (Male).” See Figure $\PageIndex{1}$ [1] for an image of a Foley catheter kit. Steps Disclaimer: Always review and follow agency policy regarding this specific skill. - Gather supplies: peri-care supplies, clean nonsterile gloves, Foley catheter kit, extra pair of sterile gloves, Velcro TM catheter securement device to secure Foley catheter to leg, linen bag, wastebasket, and light source (i.e., goose neck lamp or flashlight). - Perform safety steps: - Perform hand hygiene. - Check the room for transmission-based precautions. - Introduce yourself, your role, the purpose of your visit, and an estimate of the time it will take. - Confirm patient ID using two patient identifiers (e.g., name and date of birth). - Explain the process to the patient. - Be organized and systematic. - Use appropriate listening and questioning skills. - Listen and attend to patient cues. - Ensure the patient’s privacy and dignity. - Assess ABCs. - Assess for latex/iodine allergies, enlarged prostate, joint limitations for positioning, and any history of previous issues with catheterization. - Prepare the area for the procedure: - Place hand sanitizer for use during/after procedure on the table near the bed. - Place the catheter kit and peri-care supplies on the over-the-bed table. - Secure the wastebasket and linen cart/bag near the bed for disposal. - Ensure adequate lighting. Enlist assistance for positioning if needed. - Raise the opposite side rail. Set the bed to a comfortable height. - Position the patient supine and drape the patient with a bath blanket, exposing only the necessary area to maintain patient privacy. - Apply clean nonsterile gloves and perform peri-care. - Remove gloves and perform hand hygiene. - Open the outer package wrapping. Remove the sterile wrapped box with the paper label facing upward to avoid spilling contents and place it on the bedside table or, if possible, between the patient’s legs. Place the plastic package wrapping at the end of the bed or on the side of the bed near you, with the opening facing you or facing upwards for waste. - Open the kit to create and position a sterile field (if on bedside table): - Open first flap away from you. - Open second flap toward you. - Open side flaps. - Only touch the outer 1” edge of the field to position the sterile field on the table. - Carefully remove the sterile drape from the kit. Touching only the outermost edges of the drape, unfold and place the touched side of the drape closest to linen, under the patient. Vertically position the drape between the patient’s legs to allow space for the sterile box and sterile tray. Do not reach over the drape as it is placed. - Wash your hands and apply sterile gloves. - OPTIONAL: Place the fenestrated drape over the patient’s perineal area with gloves on inside of the drape, away from the patient’s gown, with peri-area visible through the opening. Maintain sterility. - Empty the syringe or package of lubricant into the plastic tray. Place the empty syringe/package on the sterile outer package. - Simulate application (do not open) of the iodine cleanser to the cotton. Place package on sterile outer package. - Remove the sterile urine specimen container and cap and set them aside. - Remove the tray from the top of the box and place on sterile drape. - Carefully remove the plastic catheter covering, while keeping the catheter in the container. Attach the syringe filled with sterile water to the balloon port of the catheter; keep the catheter sterile. - Lubricate the tip of the catheter by dipping it in lubricant and replace it in the box. Maintain sterility. - If preparing the kit on a bedside table, place the plastic tray on top of the sterile box and carry it as one unit to the sterile drape between the patient’s legs, taking care not to touch your gloves on the patient’s legs or bed linens. - Place the top plastic tray on the sterile drape nearest to the patient. An alternate option is to leave the plastic tray on top of the box until after cleaning is complete. - Tell the patient that you are going to clean the catheterization area and they will feel a cold sensation. Your nondominant hand will now be nonsterile. This hand must remain in place throughout the procedure. - With your sterile dominant hand, use the forceps to pick up a cotton ball. Cleanse the glans penis with a saturated cotton ball in a circular motion from the center of the meatus outward. Discard the cotton ball after use into the plastic outer wrap, not crossing the sterile field. Repeat for a total of three times using a new cotton ball each time. Discard the forceps in the plastic bag without touching your sterile gloved hand to the bag. - Pick up the catheter with your sterile dominant hand. Instruct the patient to take a deep breath and exhale or “bear down” as if to void, as you steadily insert the catheter, maintaining sterility of the catheter, until urine is noted in the tube. - Once urine is noted, continue inserting to the catheter bifurcation. - With your nondominant/nonsterile hand, continue to hold the penis, and use your thumb and index finger to stabilize the catheter. With the dominant hand, inflate the retention balloon with the water-filled syringe to the level indicated on the balloon port of the catheter. With the plunger still pressed, remove the syringe and set it aside. Pull back on the catheter slightly until resistance is met, confirming the balloon is in place. Replace the foreskin, if retracted, for the procedure. If the patient experiences pain during balloon inflation, deflate the balloon and insert the catheter farther into the bladder. If pain continues with the balloon inflation, remove the catheter and notify the patient’s provider. - Remove the sterile draping and supplies from the bed area and place them on the bedside table. Remove the bath blanket and reposition the patient. - Remove your gloves and perform hand hygiene. - Apply new gloves. Secure the catheter with the securement device, allowing room to not pull on the catheter. - Place the drainage bag below the level of the bladder and attach the bag to the bed frame. - Perform peri-care as needed; assist the patient to a comfortable position. - Dispose of waste and used supplies. - Remove your gloves and perform hand hygiene. - Assist the patient to a comfortable position, ask if they have any questions, and thank them for their time. - Ensure safety measures when leaving the room: - CALL LIGHT: Within reach - BED: Low and locked (in lowest position and brakes on) - SIDE RAILS: Secured - TABLE: Within reach - ROOM: Risk-free for falls (scan room and clear any obstacles) - Perform hand hygiene. - Document the procedure and related assessment findings. Report any concerns according to agency policy. - ”Open Foley Kit 3I3A0654.jpg” by Deanna Hoyord, Chippewa Valley Technical College is licensed under CC BY 4.0 ↵	1,552	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/21%3A_Facilitation_of_Elimination/21.10%3A_Checklist_for_Foley_Catheter_Insertion_(Male)	libretexts	libretexts-0000.json.gz:8265	https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/21%3A_Facilitation_of_Elimination/21.10%3A_Checklist_for_Foley_Catheter_Insertion_(Male)
Zkio310FlM4JWtxS	Observation and Assessment in Early Childhood Education	The key to a high-quality program is contingent upon what happens inside the classroom environment. Let’s examine how both process quality and structural quality work together to influence positive outcomes for children. Process quality refers to the types of interactions that occur throughout the day between the teachers, children, families, and administrators. Process quality also considers the types of materials that are available for the children to use, as well as the activities that children engage in throughout their day. Lastly, process quality takes into account the health, well-being and safety of the children. Structural quality on the other hand, refers to the features and characteristics of a program. More specifically, the class size, teacher-to-child ratios, teacher qualifications and experiences, teacher pay scale, along with the allotted square footage for play space define quality. Although process quality is thought to have a more direct impact on child outcomes as compared to structural quality , researchers and leaders in the field of early care and education agree that process and structural indicators are interrelated, and when combined together they promote the highest quality experiences. For example, when groups are smaller, teachers tend to have more positive, supportive, and stimulating interactions with children. Warm and nurturing interactions are directly linked to children’s social competence and future academic success, and such interactions are essential to high quality. Early childhood teachers who are more highly qualified and have smaller groups can more effectively provide individualized, responsive learning opportunities. Finally, higher teacher wages have consistently been linked to higher process quality. [1] Diagram that illustrates how structural quality leads to curriculum and process quality which are connected. Curriculum and process quality both lead to child outcomes. Ultimately the diagram illustrates that structural quality directly leads to child outcomes. - NIEER. (2002). High Quality Preschool: Why We Need It and What It Looks Like. Retrieved from: https://www.readingrockets.org/article/high-quality-preschool-why-we-need-it-and-what-it-looks ↵	405	common-pile/pressbooks_filtered	https://pressbooks.nscc.ca/ece-observation/chapter/process-quality-and-structural-quality/	pressbooks	pressbooks-0000.json.gz:22252	https://pressbooks.nscc.ca/ece-observation/chapter/process-quality-and-structural-quality/
CyhWZ1eShnZrIc8F	Women's Autobiography	CHAPTER IX The next important event in my life was my visit to Boston, in May, 1888. As if it were yesterday I remember the preparations, the departure with my teacher and my mother, the journey, and finally the arrival in Boston. How different this journey was from the one I had made to Baltimore two years before! I was no longer a restless, excitable little creature, requiring the attention of everybody on the train to keep me amused. I sat quietly beside Miss Sullivan, taking in with eager interest all that she told me about what she saw out of the car window: the beautiful Tennessee River, the great cotton-fields, the hills and woods, and the crowds of laughing negroes at the stations, who waved to the people on the train and brought delicious candy and popcorn balls through the car. On the seat opposite me sat my big rag doll, Nancy, in a new gingham dress and a beruffled sunbonnet, looking at me out of two bead eyes. Sometimes, when I was not absorbed in Miss Sullivan’s descriptions, I remembered Nancy’s existence and took her up in my arms, but I generally calmed my conscience by making myself believe that she was asleep. As I shall not have occasion to refer to Nancy again, I wish to tell here a sad experience she had soon after our arrival in Boston. She was covered with dirt—the remains of mud pies I had compelled her to eat, although she had never shown any special liking for them. The laundress at the Perkins Institution secretly carried her off to give her a bath. This was too much for poor Nancy. When I next saw her she was a formless heap of cotton, which I should not have recognized at all except for the two bead eyes which looked out at me reproachfully. When the train at last pulled into the station at Boston it was as if a beautiful fairy tale had come true. The “once upon a time” was now; the “far-away country” was here. We had scarcely arrived at the Perkins Institution for the Blind when I began to make friends with the little blind children. It delighted me inexpressibly to find that they knew the manual alphabet. What joy to talk with other children in my own language! Until then I had been like a foreigner speaking through an interpreter. In the school where Laura Bridgman was taught I was in my own country. It took me some time to appreciate the fact that my new friends were blind. I knew I could not see; but it did not seem possible that all the eager, loving children who gathered round me and joined heartily in my frolics were also blind. I remember the surprise and the pain I felt as I noticed that they placed their hands over mine when I talked to them and that they read books with their fingers. Although I had been told this before, and although I understood my own deprivations, yet I had thought vaguely that since they could hear, they must have a sort of “second sight,” and I was not prepared to find one child and another and yet another deprived of the same precious gift. But they were so happy and contented that I lost all sense of pain in the pleasure of their companionship. One day spent with the blind children made me feel thoroughly at home in my new environment, and I looked eagerly from one pleasant experience to another as the days flew swiftly by. I could not quite convince myself that there was much world left, for I regarded Boston as the beginning and the end of creation. While we were in Boston we visited Bunker Hill, and there I had my first lesson in history. The story of the brave men who had fought on the spot where we stood excited me greatly. I climbed the monument, counting the steps, and wondering as I went higher and yet higher if the soldiers had climbed this great stairway and shot at the enemy on the ground below. The next day we went to Plymouth by water. This was my first trip on the ocean and my first voyage in a steamboat. But the rumble of the machinery made me think it was thundering, and I began to cry, because I feared if it rained we should not be able to have our picnic out of doors. I was more interested, I think, in the great rock on which the Pilgrims landed than in anything else in Plymouth. I could touch it, and perhaps that made the coming of the Pilgrims and their toils and great deeds seem more real to me. I have often held in my hand a little model of the Plymouth Rock which a kind gentleman gave me at Pilgrim Hall, and I have fingered its curves, the split in the centre and the embossed figures “1620,” and turned over in my mind all that I knew about the wonderful story of the Pilgrims. How my childish imagination glowed with the splendour of their enterprise! I idealized them as the bravest and most generous men that ever sought a home in a strange land. I thought they desired the freedom of their fellow men as well as their own. I was keenly surprised and disappointed years later to learn of their acts of persecution that make us tingle with shame, even while we glory in the courage and energy that gave us our “Country Beautiful.” Among the many friends I made in Boston were Mr. William Endicott and his daughter. Their kindness to me was the seed from which many pleasant memories have since grown. One day we visited their beautiful home at Beverly Farms. I remember with delight how I went through their rose-garden, how their dogs, big Leo and little curly-haired Fritz with long ears, came to meet me, and how Nimrod, the swiftest of the horses, poked his nose into my hands for a pat and a lump of sugar. I also remember the beach, where for the first time I played in the sand. It was hard, smooth sand, very different from the loose, sharp sand, mingled with kelp and shells, at Brewster. Mr. Endicott told me about the great ships that came sailing by from Boston, bound for Europe. I saw him many times after that, and he was always a good friend to me; indeed, I was thinking of him when I called Boston “the City of Kind Hearts.”	1,433	common-pile/pressbooks_filtered	https://cod.pressbooks.pub/womenlifewriting/chapter/the-project-gutenberg-ebook-of-the-story-of-my-life-by-helen-keller-12/	pressbooks	pressbooks-0000.json.gz:99315	https://cod.pressbooks.pub/womenlifewriting/chapter/the-project-gutenberg-ebook-of-the-story-of-my-life-by-helen-keller-12/
01zfbeyaW56B1RaV	Designing and Developing High Quality Student-Centred Online/Hybrid Learning Experiences	2 Once we have our well-structured and organized course shell, we next move onto the question of introducing students to this learning environment. Our first communications with them and our initial introductions can help set the stage for subsequent interactions. We want to come off as human and supportive, and generate as much excitement as we can. Reflection The Goal: Making a First Impression Similar to the previous section, we should start by asking, “What is the goal of this initial introduction?” Though each instructor may have slightly different goals, it is probably safe to broadly identify a few ways that we’d like to be thought of. Select the “+” icons below for more details. How can we humanize our communication and start off positively? As instructors, we want our students to engage with each other and us during our lessons. Whether they are synchronous or not, we always want to see students motivated by their own interest, sharing opinions, and exploring ideas. We are also the ones that set the tone for our course. The way we introduce the course and the way we initially communicate with students provide students with their first impression of us as instructors. Activity: Evaluating First Words What is your first communication to students? Is it a welcome message email? Try showing it to someone who you think could give you some honest feedback about the impression of you your message gives. Do you seem… - laidback? - formal? - demanding? - casual? - excited? - bored? - stuffy? - strict? - passionate? - funny? Is there a disconnect anywhere? Leading by Example Fostering a Community in the Classroom The point of our initial message to students is to get them interested and excited for the course. To help them see, as we do, the reasons our subjects are so interesting and why they are worth learning. But, this is only the first step. We don’t just send one email and end it there. We are trying to build a learning community. We want to avoid the sound of crickets when we ask a question. We want students to engage with the material and share their ideas with their classmates. Activity: What goes into a Community? Engagement and open discourse in a classroom require a sense of community in the online space. Students who don’t feel comfortable are unlikely to share their ideas. Fostering a sense of community is a great goal for faculty to have, but it takes time. Researchers who advocate for building a community of inquiry put forward a conceptual framework with three distinct aspects: cognitive presence, social presence, and teaching presence.[2] Select the “+” icons below for more details. Learn more about the Community of Inquiry Model. This sense of community is not created overnight, but is facilitated throughout the entire semester. Designing activities that allow for cognitive presence, while creating a place for students to develop social relationships takes intention and effort. We want to show them that we are actively going to build a community throughout the semester, and that they are all encouraged to participate. We want to lead by example, showing them that we are going to be members of this community, that we will support them, and finally, that we are excited about the course. The first week of the course is an opportunity to set the tone for the rest of the semester. Building Pathways and Creating Spaces In the last chapter, we discussed the importance of creating intuitive pathways through the course, and the structural areas of the course. In the same way, we can apply these concepts to our own communication with students. Instructor Information An important pathway that students should know about is how they can reach you. - What is your contact information? - How would you like students to contact you? - Do you have office hours? If so, how can students attend? - Do you strive to answer emails in a certain time frame? This information is usually found on a faculty contact information page. Ensure that it is easy to find in the course, and has all the information that a student would need in order to feel comfortable to contact you. A picture can help make you seem more approachable. A Place to Ask Questions Creating a designated place for students to ask general questions can help in a number of ways. First, it can limit emails to you as a bank of common questions is collected over the semester. This acts as a resource that students can check or one that you can direct students to. It also acts as a space for students to answer each other. Facilitating this type of interaction helps build a community of learners. Additionally, it sends a message of support. Even if a student doesn’t use the resource, it lets them know that you support them. The easiest way to create this space is to dedicate a discussion board forum to asking questions. It is important that once this space is created it is monitored. Going Beyond Text Richard Mayer is credited with an oft-cited set of 12 principles for effective multimedia instruction.[3] Among the principles is the “personalization” principle, which states that students learn better when the language used is more casual and directed to the learner. The idea is that such language creates a stronger social bond than impersonal and formal language. Create a Welcome Video Applying the personalization principle in a basic sense could involve evaluating your text-based welcome message and considering how to make the tone more casual and less formal. You probably don’t speak overly formally, so ensuring that your text matches your natural speaking tone is something we can do to seem more human to our students. But we don’t have to stick to text. An introduction is a perfect place to substitute traditional text for more engaging video. Whether or not you show your face on the video, simply speaking in a conversational tone about the course and yourself (both as a person and an instructor) can be a great way to get your course started. This sort of introduction also provides a launch point to ask your students to introduce themselves via a video instead of text. Take Aim at the Syllabus Consider your syllabus. It is very likely to be a text-based document that isn’t riveting. Honestly, it is probably not fully read by the majority of your students. One idea is to take your syllabus online and create a more personable website for your courses. Dr. Pacansky-Brock has rethought the traditional syllabus and created an online version. Not only is this more aesthetically pleasing, but it can have an atmosphere that does not exist with a text-based document. Short videos, images, and additional information can be added to the syllabus. Take a look at some of these examples and consider the extra value that these give to students when they first enter the course. - Example 1: Alex Venis’ Liquid Syllabus - Example 2: Michelle Pacansky-Brock’s Liquid Syllabus - Example 3: Fabiola Torres’ Liquid Syllabus There is a lot more information on these sites than on a traditional syllabus. The tone is conversational, the instructors seem honest and forthcoming. Visually, liquid syllabi are aesthetically pleasing, and contain resources and answers to real questions (how to succeed, how the course operates) that students might wonder. In short, it can really set the tone for the semester and generate excitement for the course. Learn more about the liquid syllabus on Michelle’s blog. Keep it Going Creating a community requires intentionality and work. A community is not simply built because you had a really nice video introduction. A group of students doesn’t magically become a community overnight and remain so. It takes sustained effort. Once we’ve set the tone with our own great introductions, we should set out what we expect from students throughout the semester. Manage Expectations Set out clear expectations. Students should know what is expected of them, and what they need to succeed in the course. A great place to communicate this information is in a course overview or liquid syllabus. Be explicit. Treat students courteously, and expect the same from them. The liquid syllabi examples above include guidelines for conduct from both the instructor and student. By defining the way in which you will act, alongside what you expect from students, you give everyone clarity about their role and responsibilities. Lead by example. If you expect students to have well-written assignments, your instructions should be well written. If you expect students to participate, you should model that participation. You set the tone for the course, and students will feed off the energy and passion that you display. Model good student behaviour yourself. Best Practices and Expectations for Online Teaching from Penn State Check in Often You want to ensure that you are continually encouraging social interactions in the classroom. Beyond creating spaces and opportunities for students to interact with each other, you can reinforce your own presence as an instructor by checking in often, reminding students of the course’s progress, alongside any supports that are available to them. One idea is to send out a weekly email or announcement which includes a weekly to-do list and a reminder that they can contact you with further questions. This can help students stay on track with their work and remind them that they can reach out to you for assistance and support. Use regular surveys for students to voice their opinions about the course’s activities. We often ask our students for their views about the material we are teaching, but it can be useful to bring them onboard to the design aspects of the course. - Do they like the activities? - Would they prefer breakout rooms or class-wide discussions? - Is there anything they would like to see added to the course? These sorts of questions provide you with valuable data about the learning experience you are creating. In addition, when students see their opinions being put into practice it demonstrates to them that their views are valued. Activity: Humanize your Communication For this activity, you are encouraged to make one improvement to the way you introduce yourself to your students. Consider any of the three following options: Option 1 – Revise Your Welcome Message Take a look at your response to the first activity and initial reflection. Brainstorm ways to improve your welcome message to students. Consider the language and the information that you are communicating. Try to rewrite it to better capture the teaching personality that you want to share with students. Option 2 – Create a Welcome Video - Use your phone or webcam to record yourself introducing yourself and the course. - Talk to your students about what they can expect. - Keep it short (1-3 minutes). - Feel free to add images as well if you’d like. Option 3 – Create a Liquid Syllabus Google Sites is a suggested platform, but you can explore other options as well. Reach out to an educational technology specialist at your institution for suggestions and tips. Refer to the examples in this chapter and create a liquid syllabus that fits your course and your teaching style. Be sure to include all the information that you want students to know, including any resources and supports that they might need. - Garrison, D. R., Anderson, T., & Archer, W. (1999). Critical inquiry in a text-based environment: Computer conferencing in higher education. Internet and Higher Education, 2(2-3), 87-105. ↵ - Ibid. ↵ - Mayer, R. E. Applying the science of learning: Evidence-based principles for the design of multimedia instruction. American Psychologist 63.8, 760-9. ↵	2,538	common-pile/pressbooks_filtered	https://opentextbooks.uregina.ca/qualitycourses/chapter/orienting-students-to-the-learning-environment/	pressbooks	pressbooks-0000.json.gz:17886	https://opentextbooks.uregina.ca/qualitycourses/chapter/orienting-students-to-the-learning-environment/
vRqvuiJCIGEm9cgV	2.2: The Analects	2.2: The Analects THE ANALECTS Confucius (551-479 B.C.E.) Compiled ca. 200 B.C.E. China Confucius (or "Kongzi" in Chinese) was deeply concerned about the problem of social chaos and explored ways to achieve social order. Inspired by the early rulers of the Zhou Dynasty (ca. 1045-256 B.C.E.), whom he considered exemplary, Confucius developed his philosophy about government, morality, ethics, social roles, and the importance of rituals. As a teacher, Confucius had a great number of disciples during his time. The Analects , Confucius had a great number of disciples during his time. The Analects , translated as "Collected Conversations," were complied by later Confucian scholars, reaching their complete form around the second century B.C.E. The Analects are perhaps the most well-known text in Confucianism, belonging to the so-called "Four Books" of this tradition. Confucianism, which is known as Ruxue (Doctrine of the Sages) in China, forms a large part of the basis of many East Asian cultures. Written by Kyounghye Kwon THE ANALECTS Confucius, translated by James Legge [1893] BOOK I. HSIO R. Chapter I. The Master said, 'Is it not pleasant to learn with a constant perseverance and application? Is it not delightful to have friends coming from distant quarters? Is he not a man of complete virtue, who feels no discomposure though men may take no note of him?' Chapter IV . The philosopher Tsang said, 'I daily examine myself on three points:-- whether, in transacting business for others, I may have been not faithful;-- whether, in intercourse with friends, I may have been not sincere;-- whether I may have not mastered and practised the instructions of my teacher.' Chapter XI . The Master said, 'While a man's father is alive, look at the bent of his will; when his father is dead, look at his conduct. If for three years he does not alter from the way of his father, he may be called filial.' BOOK II. WEI CHANG. Chapter I . The Master said, 'He who exercises government by means of his virtue may be compared to the north polar star, which keeps its place and all the stars turn towards it.' Chapter II. The Master said, 'In the Book of Poetry are three hundred pieces, but the design of them all may be embraced in one sentence-- "Having no depraved thoughts."' Chapter IV. The Master said, 'At fifteen, I had my mind bent on learning. At thirty, I stood firm. At forty, I had no doubts. At fifty, I knew the decrees of Heaven. At sixty, my ear was an obedient organ for the reception of truth. At seventy, I could follow what my heart desired, without transgressing what was right.' Chapter VII . Tsze-yu asked what filial piety was. The Master said, 'The filial piety of now-a-days means the support of one's parents. But dogs and horses likewise are able to do somehting in the way of support;-- without reverence, what is there to distinguish the one support given from the other?' Chapter XI. The Master said, 'If a man keeps cherishing his old knowledge, so as continually to be acquiring new, he may be a teacher of others.' Chapter XIX. The Duke Ai asked, saying. 'What should be done in order to secure the submission of the people?' Confucius replied, 'Advance the upright and set aside the crooked, then the people will submit. Advance the crooked and set aside the upright, then the people will not submit.' BOOK III. PA YIH. Chapter V. The Master said, 'The rude tribes of the east and north have their princes, and are not like the States of our great land which are without them.' Chapter XXI. The Duke Ai asked Tsai Wo about the altars of the spirits of the land. Tsai Wo replied, 'The Hsia sovereign planted the pine tree about them; the men of the Yin planted the cypress; and the men of the Chau planted the chestnut tree, meaning thereby to cause the people to be in awe.' When the Master heard it, he said, 'Things that are done, it is needless to speak about; things that have had their course, it is needless to remonstrate about; things that are past, it is needless to blame.' BOOK IV. LE JIN. Chapter VIII. The Master said, 'If a man in the morning hear the right way, he may die in the evening without regret.' Chapter XV. The Master said, 'Shan, my doctrine is that of an all-pervading unity.' The disciple Tsang replied, 'Yes.' The Master went out, and the other disciples asked, saying, 'What do his words mean?' Tsang said, 'The doctrine of our master is to be true to the principles of our nature and the benevolent exercise of them to others,-- this and nothing more.' BOOK V. KUNG-YE CH'ANG Chapter VIII. The Master said to Tsze-kung, 'Which do you consider superior, yourself or Hui?' Tsze-kung replied, 'How dare I compare myself with Hui? Hui hears one point and knows all about a subject; I hear one point, and know a second.' The Master said, 'You are not equal to him. I grant you, you are not equal to him.' Chapter IX. Tsai Yu being asleep during the daytime, Master said, 'Rotten wood cannot be carved; a wall of dirty earth will not receive the trowel. This Yu!-- what is the use of my reproving him?' The Master said, 'At first, my way with men was to hear their words, and give them credit for their conduct. Now my way is to hear their words, and look at their conduct. It is from Yu that I have learned to make this change.' Chapter X. The Master said, 'I have not seen a firm and unbending man.' Someone replied, 'There is Shan Ch'ang.' 'Ch'ang,' said the Master, 'is under the influence of his passions; how can he be pronounced firm and unbending?' Chapter XIX. Chi Wan thought thrice, and then acted. When the Master was informed of it, he said, 'Twice may do.' Chapter XXV. Yen Yuan and Chi Lu being by his side, the Master said to them, 'Come, let each of you tell his wishes.' Tsze-lu said, 'I should like, having chariots and horses, and light fur dresses, to share them with my friends, and though they should spoil them, I would not be displeased.' Yen Yuan said, 'I should like not to boast of my excellence, nor to make a display of my meritorious deeds.' Tsze-lu then said, 'I should like, sir, to hear your wishes.' The Master said, 'They are, in regard to the aged, to give them rest; in regard to friends, to show them sincerity; in regard to the young, to treat them tenderly.' BOOK VI. YUNG YEY Chapter II. The Duke Ai asked which of the disciples loved to learn. Confucius replied to him, 'There was Yen Hui; He loved to learn. He did not transfer his anger; he did not repeat a fault. Unfortunately, his appointed time was short and he died; and now there is not such another. I have not yet heard of anyone who loves to learn as he did.' Chapter X. Yen Ch'iu said, 'It is not that I do not delight in your doctrines, but my strength is insufficient.' The Master said, 'Those whose strength is insufficient give over in the middle of the way but now you limit yourself.' Chapter XI. The Master said to Tsze-hsia, 'Do you be a scholar after the style of the superior man, and not after that of the mean man.' Chapter XVI. The Master said, 'Where the solid qualities are in excess of accomplishments, we have rusticity; where the accomplishments are in excess of the solid qualities, we have the manners of a clerk. When the accomplishments and solid qualities are equally blended, we then have the man of virtue.' Chapter XVIII. The Master said, 'They who know the truth are not equal to those who love it, and they who love it are not equal to those who delight in it.' Chapter XX. Fan Ch'ih asked what constituted wisdom. The Master said, 'To give one's self earnestly to the duties due to men, and, while respecting spiritual beings, to keep aloof from them, may be called wisdom.' He asked about perfect virtue. The Master said, 'The man of virtue makes the difficulty to be overcome his first business, and success only a subsequent consideration;-- this may be called perfect virtue.' Chapter XXI. The Master said, 'The wise find pleasure in water; the virtuous find pleasure in hills. The wise are active; the virtuous are tranquil. The wise are joyful; the virtuous are long-lived.' BOOK VII. SHU R. Chapter I. The Master said, 'A transmitter and not a maker, believing in and loving the ancients, I venture to compare myself with our old P'ang.' Chapter III. The Master said, 'The leaving virtue without proper cultivation; the not thoroughly discussing what is learned; not being able to move towards righteousness of which a knowledge is gained; and not being able to change what is not good;— these are the things which occasion me solicitude.' Chapter V. The Master said, 'Extreme is my decay. For a long time, I have not dreamed, as I was wont to do, that I saw the duke of Chau.' Chapter XV. The Master said, 'With coarse rice to eat, with water to drink, and my bended arm for a pillow;— I have still joy in the midst of these things. Riches and honours acquired by unrighteousness, are to me as a floating cloud.' Chapter XX. The subjects on which the Master did not talk, were— extraordinary things, feats of strength, disorder, and spiritual beings. BOOK VIII. T'AI-PO Chapter V. The philosopher Tsang said, 'Gifted with ability, and yet putting questions to those who were not so; possessed of much, and yet putting questions to those possessed of little; having, as though he had not; full, and yet counting himself as empty; offended against, and yet entering into no altercation; formerly I had a friend who pursued this style of conduct.' Chapter VIII. The Master said, 'It is by the Odes that the mind is aroused. It is by the Rules of Propriety that the character is established. It is from Music that the finish is received.' Chapter XIII. The Master said, 'With sincere faith he unites the love of learning; holding firm to death, he is perfecting the excellence of his course. Such an one will not enter a tottering State, nor dwell in a disorganized one. When right principles of government prevail in the kingdom, he will show himself; when they are prostrated, he will keep concelaed. When a country is well-governed, poverty and a mean condition are things to be ashamed of. When a country is ill-governed, riches and honour are things to be ashamed of.' Chapter XVII. The Master said, 'Learn as if you could not reach your object, and were always fearing also lest you should lose it.' BOOK IX. TSZE HAN. Chapter V. The Master was put in fear in K'wang. He said, 'After the death of King Wan, was not the cause of truth lodged here in me? If Heaven had wished to let this cause of truth perish, then I, a future mortal, should not have got such a relation to that cause. While Heaven does not let the cause of truth perish, what can the people of K'wang do to me?' Chapter VI. A high officer asked Tsze-kung, saying, 'May we not say that your Master is a sage? How various is his ability!' Tsze-kung said, 'Certainly Heaven has endowed him unlimitedly. He is about a sage. And, moreover, his ability is various.' The Master heard of the conversation and said, 'Does the high officer know me? When I was young, my condition was low, and therefore I acquired my ability in many things, but they were mean matters. Must the superior man have such variety of ability? He does not need variety of ability.' Loa said, 'The Master said, "Having no official employment, I acquired many arts."' Chapter XI. The Master being very ill, Tsze-lu wished the disciples to act as ministers to him. During a remission of his illness, he said, 'Long has the conduct of Yu been deceitful! By pretending to have ministers when I have them not, whom should I impose upon? Should I impose upon Heaven? And though I may not get a great burial, shall I die upon the road?' Chapter XIII. The Master was wishing to go and live among the nine wild tribes of the east. Someone said, 'They are rude. How can you do such a thing?' Chapter XIV. The Master said, 'I returned from Wei to Lu, and then the music was reformed, and the pieves in the Royal songs and Praise songs all found their proper places.' Chapter XVI. The Master standing by a stream, said, 'It passes on just like this, not ceasing day or night!' Chapter XXII . The Master said, 'A youth is to be regarded with respect. How do we know that his future will not be equal to our present? If he reach the age of forty or fifty, and has not made himself heard of, then indeed he will not be worth being regarded with respect.' BOOK X. HEANG TANG. Chapter II. When he was waiting at court, in speaking with the great officers of the lower grade, he spake freely, but in a straightforward manner; in speaking with those of the higher grade, he did so blandly, but precisely. When the ruler was present, his manner displayed respectful uneasiness; it was grave, but self-possessed. Chapter IV. When he entered the palace gate, he seemed to bend his body, as if it were not sufficient to admit him. When he was standing, he did not occupy the middle of the gate-way; when he passed in or out, he did not tread upon the threshold. When he was passing the vacant place of the prince, his countenance appeared to change, and his legs to bend under him, and his words came as if he hardly had breath to utter them. He ascended the reception hall, holding up his robe with both his hands, and his body bent; holding in his breath also, as if he dared not breathe. When he came out from the audience, as soon as he had descended one step, he began to relax his countenance, and had a satisfied look. When he had got to the bottom of the steps, he advanced rapidly to his place, with his arms like wings, and on occupying it, his manner still showed respectful uneasiness. BOOK XI. HSIEN TSIN. Chapter IX. When Yen Yuan died, the Master bewailed him exceedingly, and the disciples who were with him said, 'Master your grief is excessive?' 'Is it excessive?' said he. 'If I am not to mourn bitterly for this man, for whom should I mourn?' Chapter X. When yen Yuan died, the disciples wished to give him a great funeral, and the Master said, 'You may not do so.' The disciples did bury him in great style. The Master said, 'Hui behaved towards me as his father. I have not been able to treat him as my son. The fault is not mine; it belongs to you, O disciples.' BOOK XII. YEN YUAN. Chapter II. Chung-kung asked about perfect virtue. The Master said, 'It is, when you go abroad, to behave to every one as if you were receiving a great guest; to employ the people as if you were assisting at a great sacrifice; not to do to others as you would not wish done to yourself; to have no murmuring against you in the country, and none in the family.' Chung-kung said, 'Though I am deficient in intelligence and vigour, I will make it my business to practise this lesson.' Chapter V. Sze-ma Niu, full of anxiety, said, 'Other men all have their brothers, I only have not.' Tsze-hsia said to him, 'There is the following saying which I have heard:— '"Death and life have their determined appointment; riches and honours depend upon Heaven." 'Let the superior man never fail reverentially to order his own conduct, and let him be respectful to others and observant of propriety:—then all within the four seas will be his brothers. What has the superior man to do with being distressed because he has no brothers?' Chapter VII. Tsze-kung asked about government. The Master said, 'The requisites of government are that there be sufficiency of food, sufficiency of military equipment, and the confidence of the people in their ruler.' Tsze-kung said, 'If it cannot be helped, and one of these must be dispensed with, which of the three should be foregone first?' 'The military equipment,' said the Master. Tsze-kung again asked, 'If it cannot be helped, and one of the remaining two must be dispensed with, which of them should be foregone?' The Master answered, 'Part with the food. From of old, death has been the lot of all men; but if the people have no faith in their rulers, there is no standing for the state.' Chapter XI. The Duke Ching, of Ch'i, asked Confucius about government. Confucius replied, 'There is government, when the prince is prince, and the minister is minister; when the father is father, and the son is son.' 'Good!' said the duke; 'if indeed; the prince be not prince, the minister not minister, the father not father, and the son not son, although I have my revenue, can I enjoy it?' Chapter XVIII. Chi K'ang, distressed about the number of thieves in the state, inquired of Confucius how to do away with them. Confucius said, 'If you, sir, were not covetous, although you should reward them to do it, they would not steal.' Chapter XIX. Chi K'ang asked Confucius about government, saying, 'What do you say to killing the unprincipled for the good of the principled?' Confucius replied, 'Sir, in carrying on your government, why should you use killing at all? Let your evinced desires be for what is good, and the people will be good. The relation between superiors and inferiors, is like that between the wind and the grass. The grass must bend, when the wind blows across it.' BOOK XIV. HSIEN WAN. Chapter XXV. The Master said, 'In ancient times, men learned with a view to their own improvement. Now-a-days, men learn with a view to the approbation of others Chapter XXXVII. The Master said, 'Alas! there is no one that knows me.' Tsze-kung said, 'What do you mean by thus saying— that no one knows you?' The Master replied, 'I do not murmur against Heaven. I do not grumble against men. My studies lie low, and my penetration rises high. But there is Heaven;— that knows me!' Chapter XLI. Tsze-lu happening to pass the night in Shih-man, the gatekeeper said to him, 'Whom do you come from?' Tsze-lu said, 'From Mr. K'ung [Confucius].' 'It is he,— is it not?'— said the other, 'who knows the impracticable nature of the times and yet will be doing in them.' Chapter XLVI. Yuan Zang was squatting on his heels, and so waited the approach of the Master, who said to him, 'In youth not humble as befits a junior; in manhood, doing nothing worthy of being handed down; and living on to old age:— this is to be a pest.' With this he hit him on the shank with his staff. BOOK XVII. YANG HO. Chapter IV. The Master, having come to Wu-ch'ang, heard there the sound of stringed instruments and singing. Tsze-yu replied, 'Formerly, Master, I heard you say,-- "When the man of high station is well instructed, he loves men; when the men of low station is well instructed, he is easily ruled."' The Master said, 'My disciples, Yen's words are right. What I said was only in sport.' Chapter IX. The Master said, 'My children, why do you not study the Book of Poetry? The Odes serve to stimulate the mind. They may be used for purposes of self-contemplation. They teach the art of sociability. They show how to regulate feelings of resentment. From them you learn the more immediate duty of serving one's father, and the remoter one of serving one's prince. From them we become largely acquainted with the names of birds, beasts and plants.' Chapter XIX. The Master said, 'I would prefer not speaking.' Tsze-kung said, 'If you, Master, do not speak, what shall we, your disciples, have to record?' The Master said, 'Does Heaven speak? The four seasons pursue their courses, and all things are continually being produced, but does Heaven say anything?' Chapter XXI. Tsai Wo asked about the three years' mourning for parents, saying that one year was long enough. 'If the superior man,' said he, 'abstains for three years from the observances of propriety, those observances will be quite lost. If for three years he abstains from music, music will be ruined. Within a year the old grain is exhausted, and the new grain has sprung up, and, in procuring fire by friction, we go through all the changes of wood for that purpose. After a complete year, the mourning may stop.' The Master said, 'If you were, after a year, to eat good rice, and wear embroidered clothes, would you feel at ease?' 'I should,' replied Wo. The Master said, 'If you can feel at ease, do it. But a superior man, during the whole period of mourning, does not enjoy pleasant food which he may eat, nor derive pleasure from music which he may hear. He also does not feel at ease, if he is comfortably lodged. Therefore he does not do what you propose. But now you feel at ease and may do it.' Tsai Wo then went out, and the Master said, 'This shows Yu's want of virtue. It is not till a child is three years old that it is allowed to leave the arms of its parents. And the three years' mourning is universally observed throughout the empire. Did Yu enjoy the three years' love of his parents?' BOOK XVIII. WEI TSZE Chapter V. The madman of Ch'u, Chieh-yu, passed by Confucius, singing and saying, 'O FANG! O FANG! How is your virtue degenerated! As to the past, reproof is useless; but the future may be stilll be provided against. Give up your vain pursuit. Give up your vain pursuit. Peril awaits those who now engage in affairs of government.' Confucius alighted and wished to converse with him, but Chieh-yu hastened away, so that he could not talk with him. Chapter VI. Ch'ang-tsu and Chieh-ni were at work in the field togetehr, when Confucius passed by them, and set Tsze-lu to inquire for the ford. Ch'ang-tsu said, 'Who is he that holds the reins in the carriage there?' Tsze-lu told him, 'It is Confucius.' 'Is it not Confucius of Lu?' asked [Ch'ang-tsu]. 'Yes.' 'He knows the ford [already].' Tsze-lu then inquired of Chieh-ni, who said to him, 'Who are you, sir?' He answered, 'I am Chung Yu.' 'Are you not disciple of Confucius of Lu?' asked the other. 'I am' 'Disorder, like a swelling flood, spreads over the whole empire, and who is he that will change its state for you? Than follow one who merely withdraws from this one and that one, had you not better follow those who have withdrawn from the world altogether?' With this he fell to covering up the seed, and proceeded with his work, without stopping. Tsze-lu went and reported their remarks, when the Master observed with a sigh, 'It is impossible to associate with birds and beasts, as if they were the same with us. If I associate not with these people,-- with mankind,-- with whom shall I associate? If right principles prevailed through the empire, there would be no use for me to change its state.'	5,192	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Literature_and_Literacy/World_Literature/World_Literature_I_-_Beginnings_to_1650_Part_I_-_The_Ancient_World_(Getty_and_Kwon)/02%3A_China/2.02%3A_The_Analects	libretexts	libretexts-0000.json.gz:20242	https://human.libretexts.org/Bookshelves/Literature_and_Literacy/World_Literature/World_Literature_I_-_Beginnings_to_1650_Part_I_-_The_Ancient_World_(Getty_and_Kwon)/02%3A_China/2.02%3A_The_Analects
RQ7eKivMhRn92wcq	Latin America, the land of opportunity. A reprint of official reports and special articles. Prepared by John Barrett ...	The material in this pamphlet is reprinted in response to a demand, which constantly reaches the International Bureau from various parts of the world, for one or all of the reports and articles quoted. Each paper was originally reprinted in an individual pamphlet, but the call soon exhausted the supply. As a matter of economy in publication, all are now combined under one cover. There is some repetition and a slight divergence of statistical figures due to different dates of original publication, but this is unavoidable under the circumstances. SOME SPECIAL PHASES NOT COMMONLY CONSID^ ERED OR UNDERSTOOD OF THE COMMERCIAL AND GENERAL RELATIONS OF THE UNITED STATES WITH HER SISTER AMERICAN REPUBLICS. The purpose of this report is to present a special view of our sister American republics and awaken greater interest throughout the United States in their progress and development. The time is at hand that calls for what might be termed a widespread Latin American movement in the United States. The commercial, economic, and social conditions of our southern neighbors invite our immediate and particular attention. To say that it may be " now or never " with Xorth American prestige and trade in Central and South America is not a statement of an alarmist or pessimist. It is a simple and logical conclusion drawn from a thorough study of the actual situation. There never was a period in the history of the relations of the United States with her sister American republics which afforded such combined opportunity and necessity as the present for the development not only of our moral influence but of our commercial interests. On the other hand there never was a time when European nations and business interests put forth such efforts as they are now legitimately exerting to increase their own prestige and trade in South America. Although the situation should be one of closest rivalry where the United States can and ought to win, if it does not give* Europe too long a start the advantage now is decidedly with thft latter. There is no gainsaying the fact that Latin America to-day is; strongly inclined to be more sympathetic in its actual likes and dislikes with the old world than with the United States, because of plain reasons of race, language, and association which are discussed later on. CREDIT TO CONSULS AND SPECIAL AGENTS, Too high praise can not* be given to our consuls throughout Latin America for their excellent trade reports, nor too much credit allotted to the special agents who have recently visited this part of the world and carefully described the commercial conditions and opportunities. a Published first in part, September, 1906, when Mr. Barrett was United States minister to Colombia, in the Daily Consular and Trade Reports of the Department of Commerce and Labor, and republished in full, February, 1907, by the International Bureau of American Republics. AMERICA. ig»V$:§p0Ety aawev6Ef dbks^rrbt trespass on their specific field nor expect to compete with them in figures of trade exchange, country by country, or in a statement of articles that can be bought or sold. It rather discusses other phases of our commercial, social, and general association as these affect the expansion or contraction of our commerce and prestige. We may go on writing about trade opportunities until doomsday, but, if we do not get at the bottom of our relationship with Latin Americans, we will never make the conquest of their markets and affections — an absolutely necessary combination for permanent good — which is the goal of our effort. was established in 1890. new. Most of our diplomatic and consular representatives are also aware of the facts stated, but the great majority of our people are unfamiliar with the true situation and it is to them that this discussion is directed. LATIN AMERICA MOVING RAPIDLY FORWARD. Many of our sister republics are now making a progress that challenges the attention and respect of the world. Some of them are going forward with such splendid energy that they are running a close race with the past records of the United States and the present achievements of Japan. Others are on the verge of a progressive delight knowing admirers of their latent possibilities. In short, it is safe to predict a forward movement during the next decade for the Latin American republics that will give them a position and prominence among the nations of the earth not thought possible a few years ago. It will bring to them a commerce for which the United States and Europe will compete with every resource at their command. THE RAILROAD STATION AT SAO PAULO, THE CHICAGO OF BRAZIL. It was built by the English company operating the tidewater railroad over which is transported the larger part of the coffee exported through the port of Santos. It is one of the most beautiful buildings of its kind in South America and cost, approximately, $ 1,500,000. most humbly to point out that all the predictions he made ten and twelve years ago, while United States Minister to Siam, about the future of Japan and the general commercial development of the Far East, and which caused him to be called many unpleasant names by those who opposed his views, have more than come true in every respect. The premises on which he based these predictions, while outlined as a result of careful study and investigation, were not any more secure than those on which he bases his faith in the future of Latin America. PRESENT VALUE OF LATIN AMERICAN TRADE.0 To impress upon the minds of those who are very practical, the importance from a strictly commercial standpoint of the field being discussed, it is desirable before proceeding further to give some general figures covering the present extent and value of Latin American trade. A careful estimate based on the official figures of 1903, 1904, and 1905, shows that the total foreign trade, exports and imports, of the 20 Latin American republics from Mexico and Cuba south to Argentina and Chile, amounts now annually to the magnificent and surprising total approximately of $1,800,000,000 gold. The exports and imports stand about in the ratio of 5 to 3 ; that is, the former represent three-fifths and the latter two-fifths of the total. Exportations, therefore, can be placed at about $1,080,000,000, and importations at $720,000,000. Now if we went no further into this investigation, these remarkable sums alone, which show almost a phenomenal advance over those of ten years ago, would be incontrovertible arguments in favor of the United States bending its energies to increase its commerce with Latin America. Although they speak eloquently in support of the writer's contentions about the trade and progress of the Latin republics, let us note just where our country stands. EXPORTS AND IMPORTS OF THE UNITED STATES. The total exports of the United States in 1905 to Latin America were valued at $182,000,000; the total imports from Latin America to the United States at $309,000,000. This means that there is an annual balance of $127,000,000 against the United States which Latin America, in turn, uses to buy a vast quantity of articles in the more enterprising markets of Europe. Considering the greatness of the United States, the variety of its, manufactures and products, and its conditions of demand and supply, there is no valid reason why it should not now sell to Latin America as much as it purchases from it. If we study the exports and imports -of the United States from all parts of the world, we find additional proof that we are not carrying on the trade with Latin America that we ought to conduct. Only 10 per cent of our huge total of exports went to Latin America in 1905, although the latter's imports are valued at over $1,000,000,000; and only 20 per cent of our immense total of imports found their origin in that part of the world whose exports are valued at $720,000,000. LATIN AMERICA AND THE FAR EAST COMPARED, The markets of the Orient are of vast importance to the United States, but it can not be successfully contended that they will be permanently more valuable to us than those of Latin America, just because the former at the present moment buys more from us than the latter. If we had devoted one-third of the energy and spent one-tenth of the money in developing our interests in our sister republics that we have in the Far East, our trade with Latin America would be double what it is with the east coast of Asia. The total value of the foreign commerce of Latin America, having a com- an altitude of 9,371 feet, and has recently been connected by rail with the coast. paratively small population, is far in excess of that of the Far East, north of Hongkong, having an enormous population. Argentina, with only 6,000,000 people, bought and sold more in 1905 than China with 300,000,000, or Japan with 40,000,000. The foreign commerce of Chile, whose population does not exceed 3,500,000, was greater than that of eastern Siberia, Korea, Siam, Indo-China, and the Philippines combined, with a population of 50,000,000. LATIN AMERICA. potentialities ever since he first went to Asia as American minister in 1894. These facts are stated, therefore, not to decry in the least the value and importance of our commerce there, but to emphasize by comparison the value and importance of the opportunity in Latin America. APPRECIATION OF LATIN AMERICA. The writer admits that he seems to speak with an element of prejudice. Frankly he likes Latin America and Latin peoples. The more he sees of them the better he respects them. Would that more North Americans could become better acquainted with South Ameri- popular pastime. cans, study more intimately their impulses, ambitions, hopes, achievements, and see things from the Latin American standpoint. Otherwise expressed, it would be a signal blessing to international PanAmerican accord and it would inaugurate a new era immediately in the relations of the United States with her sister American republics, if, in thinking, writing, and speaking of them, their peoples, and their politics, we could follow the old Biblical adage and remove the beam from our own eye before looking for the mote in that of the Latin American. Of this very important point more will be said later on. This report is phrased in direct and earnest terms because the writer believes what he says. As suggested in the first paragraph, he holds that the United States has reached a most critical period in its relations with Latin America. What is done or accomplished during the next few years may determine forever the relative position of North American trade and prestige in Central and South America. The Pan-American Conference in Rio Janeiro and the visit of Secretary Root to South America should awaken sufficient interest throughout the United States in this part of the world to inspire our people, in general, and our newspapers, our manufacturers, our merchants, our Congressmen, our travelers, and our students of foreign intercourse, in particular, to a new and active appreciation of the Latin American republics. Without half the reason we have for improving the opportunity, European commercial, financial, and diplomatic interests, with commendable judgment and spirit which we can not criticise but must admire, are alive to the situation and doing everything legitimately in their power to gain a hold of which they can not be dispossessed. They keenly realize the present and future possibilities of the material and economic exploitation of Latin America, and they are leaving no stone unturned to gain the necessary advantages before the manufacturers and tradesmen of the United States suddenly become aroused to the situation and compete for its control. FACTORS UNFAVORABLE TO NORTH AMERICA. The first great factor unfavorable to North American trade and influence in Latin America is the essential difference in lineage and language, but this point is little appreciated. The power of similarity in race and tongue is mighty. Kinship in these respects brings men closer together. It makes them more sympathetic, and this counts much in Latin countries. The average North American, instead of carefully studying methods of counterbalancing these conditions adverse to his progress in Latin America and of adapting himself thereto, undertakes an independent line of action and ultimately fails in his purpose. The second great factor is corollary to the first, and it is one of which, in our seeming abundance of knowledge and self-confidence, wre are lamentably ignorant. Frankly termed it should be called the " holier than thou " attitude, too commonly and persistently assumed by North American statesmen, newspapers, writers, travelers, and business agents when discussing or dealing with Latin America. In other words, the people of the United States have too much and too characteristically " patronized " the peoples, customs, institutions, achievements and governments of their sister American nations. Per contra, we should give Latin America more credit for its actual and praiseworthy progress in developing stable national and municipal government, in promoting both high class and general education, in making its own excellent literature, historical and romantic, in advancing scientific investigation and invention, in solving grave social and economic problems, "and comprehensively striving under difficult conditions to reach a higher standard of civilization. How few North Americans realize that Latin American history during the last four centuries is replete with incident and event, names, and results that compare creditably with those of the United States, Europe, and Asia. How few know the names of the great heroes, statesmen, writers, and scholars who have figured prominently in evolving the Latin America of to-day. How few are aware that the principal countries and capitals of Latin America have groups of eminent scholars, scientists, and philosophers, as well as universities and professional schools, which are no less advanced than similar groups and institutions in the United States and Europe. How few North Americans, moreover, of high position in public life, in literary, scholastic, and scientific circles, visit Latin America and exchange courtesies with their fellow-statesmen and students, as they do with those of Europe. No greater blessing to Pan-American accord could now be bestowed than an exchange of actual visits and views of the leaders of Pan-American thought and action. Latin America is too much accustomed to seeing and meeting only those North Americans who are intent on making money, securing this and that concession, and thinking only of selfish material considerations and a return, with pockets filled, as soon as possible to the United States. A change, a renaissance in "higher class association, acquaintance, and friendship, will not only start an era of good will and better mutual appreciation, but indirectly prove an extraordinary advantage to commerce and trade. European countries long ago realized the distinct advantage of such intercourse with, and knowledge of, Latin America and have improved every opportunity to promote more intimate acquaintance. NORTH AMERICANS MUST LEARN OTHER LANGUAGES. As to language it is difficult to write with patience. So small is the percentage of North Americans visiting Latin America on business or pleasure who speak Spanish, or Portuguese, or French, that it is a wonder that the}- make any progress in their plans. Ninety-five per cent of the Europeans who go to Central and South America understand one of these tongues. French is mentioned because nearly all the well-educated Latin Americans speak that language. This subject requires no argument — it is simply impossible for the North American who knows none of these languages to become thoroughly " simpatico " and to master the Latin point of view in either commercial or political relations. I would that both our business schools and regular colleges might make the study of either Spanish, French, or Portuguese compulsory in order to receive a diploma. Portuguese is more important than is generally regarded, because it is the working language of Brazil — and Brazil to-day is taking rank as one of the great nations of the world ; but the average well-to-do Brazilian also speaks French. LACK OF FAST STEAMSHIP FACILITIES. In studying the causes that act as deterrents to Pan-American accord we must emphasize the lack of first-class passenger and mail steamship service, such as characterizes the systems of communication between Europe and Latin America. The long-established and welldefined association of Latin Americans with Europe has been immeasurably encouraged by the excellence of steamship facilities, which have given them ready access to the satisfactory conditions found there in turn for business transactions, education of families, and enjoyment of leisure and travel. If the average merchant and traveler of South America could reach New York with the same comfort and speed that he can proceed to Paris, there would be at once a vast and radical change in the situation favorable to the United States. This statement is not introduced as an argument for a " subsidized " merchant marine. The writer is not discussing the pros and cons of that mooted issue. He is simply stating a fact and describing a condition. That there is not one first-class mail and passenger steamer flying the American flag and running between New York in the United States and such important South American points as Rio Janeiro and Buenos Aires was given glaring prominence by the experience of the delegates to the recent Pan-American Conference in Rio Janeiro. Only a few took accommodations on the foreign vessels that make direct trips from New York to the great capital of Brazil. All the others went via Europe, where six different lines provide a score of splendid, modern, up-to-date, fast ships between the principal ports and those of South America. No Latin-American merchant or capitalist is going to North America on slow boats when there are numerous fast steamers bound for Europe with as fine arrangements as our trans- Atlantic liners. This is axiomatic, but it means the loss of millions of dollars of trade to the United States every year, according to the direct testimony of South Americans themselves. It is true that there are excellent freight-steamship facilities between North and South American ports, but they do not meet the passenger requirements any more than would a purely railway freight service suit the passenger traffic between New York and Chicago." REVOLUTIONARY MOVEMENTS EXAGGERATED. Too much importance is now attached in the United States to the idea that revolutions prevail all over Latin America and that, therefore, commerce and investments are insecure. This conception of Latin America as a whole is entirely erroneous and does our pro- gressive sister republics a great injustice. The continent of South America to-day is free of serious insurrectionary movements, with few, if any, indications of more civil wars. The recent conflict in Central America was unfortunate, but it served to emphasize the firm peace and prosperity of Mexico. The tendency of public opinion and the powerful influence of large business interests in such great nations as Mexico, Brazil, Argentina, Chile, and Peru is all against revolutionary movements, and, although now and then some slight sporadic attempt shows itself, it is most difficult for it to grow into dangerous proportions. Then, again, the gridironing of these countries with railways permits the immediate sending of troops to any place and crushing without delay incipient revolts. OTHER IMPORTANT CONSIDERATIONS. Having enlarged upon some of the most important general considerations bearing on our commercial and friendly relations with Latin America, it is now well to enumerate, without comment, a few specific but still interesting agencies that demand attention, improvement, or development, such as — (/) The use of greater care in packing goods for the long distance to be traveled, for the severe changes of climate, and for the size of parcels required in different markets; (7i-) The investment of North American capital in the resources, mines, industries, and in the construction of railways, tramway, and electric-light plants, in the more peaceful and progressive countries of South American ; and (I) The correction, through the careful diplomacy of our ministers and consuls and the just policies and methods of our business men, of the false impressions in regard to the intentions of the United States toward Latin America as existing in the minds of some Latin American editors and publicists, and the gradual development, in place In conclusion I have only to submit humbly that I hope every person whose interest in the relations of the United States with the Latin American Republics may have been awakened or increased by this little study of the situation may find time to visit Latin America — to make the " grand tour," like Secretary Root, down the Atlantic coast and up the Pacific, or vice versa, via Argentine and Chile, and confirm with his own eyes the truth of all that I have related. A BIRD'S-EYE VIEW OF SOUTH AMERICA, OUR NEIGHBOR CONTINENT—THE FABULOUS RICHES LOCKED UP IN ITS FORESTS, PLAINS, AND MOUNTAINS— TREMENDOUS POSSIBILITIES OF DEVELOPMENT, MUCH OF WHICH HAS ALREADY BEGUN. South America is distinctly the land of to-morrow. It is a continent of vast and varied possibilities. The traveler and the scholar or the merchant and the promoter will find its people, problems, and potentialities of compelling interest. And yet the ignorance prevailing generally throughout the United States in regard to this great southern continent is almost appalling. The average American, with all his close study of Europe and Asia, has neglected the history, growth, and characteristics of our sister American republics. He has been so absorbed, moreover, by our own astounding material progress and our home politics that he has given no heed to the industrial and economic movements and to the administrative achievements of South America. Now, the whole world is beginning to turn its eyes southward. Europe has been gazing thither longer than the United States — and has results to show for her attitude. Even Japan, China, South Africa, and Australia are discussing, more than we appreciate in the United States, the valuable opportunity for the extension of their commerce and trade with that wealthy, resourceful continent which is so accessible by either the Atlantic or the Pacific. More attention is given by the press of Europe to South America in a week than by all the papers of the United States in a year. There are many signs of increased interest, however, throughout this country. The International Bureau of American Republics at Washington, of which the writer is the Director, finds particular evidence of this wider interest through the growth and nature of its correspondence. The Bureau, founded sixteen years ago (1890) by the first Pan-American Conference, over which James G. Elaine presided, is maintained by the 21 republics of the Western Hemisphere, each of Avhich contributes annually a certain sum in proportion to its population. Their diplomatic representatives in Washington constitute its governing board, of which the Secretary of State of the United States is chairman ex officio. Although the Bureau has done excellent work in the past, its responsibility and programme were broadly enlarged at the third Pan-American Conference, held in Rio de Janeiro last summer. It is the intention of the International Union of American Republics — the official name that represents their united action — to make the Bureau a practical, world-recognized office and agency not only to build up commerce and trade among all the American republics, but to promote closer relations, to establish more friendly intercourse, to bring about a better understanding one of the other, and to assist the approach to one another on the educational, intellectual, moral, and social as well as material and commercial side. This is an ambitious scheme, but it is all possible of attainment. REPUBLIC. The Zoological Gardens are situated in the large and beautiful Palmero Park, which comprises an area of about 1,000 acres. The grounds are artistically laid out, and there are a number of artificial lakes, as well as attractive walks lined with shrubbery and trees. The principal species of animals are housed in separate building. These gardens become popular resorts on Sundays and holidays, at which time thousands of people visit them to inspect and admire the large collection of animals. erect a permanent home, or Temple of Peace, as he appropriately names it. This large sum, with the amounts appropriated by the United States and other American governments for the site — about $250,000— provides the Bureau with $1,000,000 for a new plant and equipment. Facing the so-called White Lot, below the White House and State, War, and Navy building, in Washington, a structure will be erected,0 not only noble in architecture and helpful in the con- the Bureau. South America has many extraordinary features of natural and artificial development that surprise the uninformed. For example: How many people realize that Brazil could completely cover the United States proper and still have room for another New England, New York, Pennsylvania, and Virginia combined ; that out of the Amazon River flows every day three times the volume of water which flows from the Mississippi, and out of the Parana twice that of the North American queen of waters. These great South American streams afford incomparable opportunities for interior navigation and the development of commerce. The North American does not stop to think, when he remembers the old geographical story about the beautiful harbor of Rio de Janeiro and the threadbare legends of yellow fever, that this capital of Brazil now has a population of 900,000, and is growing as fast as Boston, St. Louis, or Baltimore ; that it spent more money for public improvements last year than any city in the United States excepting New York ; and that to-day it is one of the most interesting national centers of civilization, industry, art, literature, and education in the world. Again, how many North Americans know that Buenos Aires, the capital of Argentina, is the largest city in the world south of the equator; that it is the second Latin city, ranking after Paris, in all the world ; that it now has a population of 1,200,000 and is growing faster than any city in the United States excepting New York or Chicago ? If surprised at this statement, they might be interested to learn that in Buenos Aires is the finest and costliest structure in the world used exclusively by one newspaper, the home of " La Prensa; " the most magnificent opera hoilse of the Western Hemisphere, costing more than $10,000,000 and erected by the Government; the handsomest and largest clubhouse in the world — that of the Jockey Club ; the most expensive system of artificial docks in all America, representing an expenditure of $50,000,000. At Lima, Peru, and at Cordoba, in Argentina, are universities whose foundations antedate Harvard and Yale. There are so many other high educational institutions which go back to the sixteenth century that we fully appreciate the compliment Secretary Root paid to South America when he said that the " newer " civilization of North America had much to learn from the " older " civilization of South America. Among the ruins of the Incas in Peru, Ecuador, and Bolivia are evidences of a wonderful age of material and intellectual development that long preceded the Spanish Con- LEZAMA PARK, BUENOS AIRES. This is one of the popular parks of the city. Its location on a beautiful hill is picturesque, from which can be seen the surrounding suburbs of La Boca and Barracas, and a long stretch of La Plata River. The Russian church is shown in the background of this view. of the Aztecs in Mexico. Referring now to exceptional commercial phases of South American development, there are some remarkable points to be borne in mind. It is predicted that within one or two years Argentina will export more wheat than the United States. Two other startling possibilities are linked with this: One is, that refrigerated beef, grown and killed in Argentina, will soon be shipped to New York, and will there be sold under the present so-called trust prices; and the other is that in a decade the northern section of Argentina will become a great cotton-growing country, competing successfully with our Southern States. REMARKABLE RAILWAY CONSTRUCTION. The North American railroad man may be surprised to learn that between Chile and Argentina is being constructed one of the long tunnels of the world. The highest points and most difficult construction that have ever been encountered in railway extension are found in Peru. All over South America elaborate programmes for new railroads are being worked out. Argentina is already gridironed with excellent systems. Chile is pushing lines in all directions. Brazil is preparing to penetrate her vast jungles and connect distant points with Rio de Janeiro. Bolivia is spending more than $50,000,000 in new work, while Colombia, Ecuador, Peru, Uruguay, Paraguay, and Venezuela are considering various practical and needed plans for new construction. Throughout the United States interest is growing in favor of building, or aiding to build, a Pan-American railway, or connections, that will literally unite North and South America with ties and bands of steel. A permanent committee, created by the second Pan-American Conference, at Mexico, in 1D01-2, and continued by the third conference, at Rio de Janeiro, in 1906, has at its head such men as exSenator Henry G. Davis, of West Virginia, and Andrew Carnegie, who not only are deeply interested in its consummation, but have the money themselves to undertake the work, if necessary. Charles M. Pepper, an authority on South American matters, recently made a careful study of the plan, and gave his conclusions in an elaborate favorable report. Elihu Root, Robert Bacon, and W. I. Buchanan approve the project. The average North American may not realize that a perpendicular line drawn south from the Statue of Liberty in New York Harbor would find nearly all of South America to the east of it. This admission sorely distresses the person who thinks of South America as directly south of the United States, but it is true nevertheless. Likewise, few stop to think that northeastern South America bulges out so far into the Atlantic that it is necessary for a ship or traveler from a North Atlantic port to proceed eastward a distance about equal to that of going to England or France before rounding this bulging point and continuing southward to Rio de Janeiro, Montevideo, and Buenos Aires. South America in its relation to North America ought really to be called " Southeast America." On the map, as we commonly study it, South America looks much smaller than North America. If we omit the great barren, frozen end of North America, or, on the other hand, leave out Alaska, South America would, in fact, entirely cover North America from Panama to Bering Sea. Although we think of South America as possessing a large waste area due to tropical heat, this portion is not any more extensive than that of North America lying barren under lasting snows or continued cold. The Tropics, moreover, as a result of marvelous vegetation, will support a great population, while the severely cold regions must always be thinly populated. SURPRISING COMPARISONS OF AREA. Comparisons often help us to grasp the size of unknown portions of the world. Brazil has already been mentioned as exceeding the United States proper in extent — the exces in favor of Brazil being about 200,000 square miles, or four times the area of New York. In Argentina, located in the South Temperate Zone, with a climate like that of the United States, could be placed all that part of our country east of the Mississippi River plus the first tier of States west of it. hold all New England, New York, and New Jersey. Finally, there is Colombia, a land of splendid promise and mighty resources, whose nearest port is only 950 miles from the nearest port of the United States. This Republic has an area as great as that of Germany, France, Holland, and Belgium combined. These comparative data may aid in increasing respect for the " small-?' South American Republics, which are too often mentioned throughout the United States in a patronizing manner. A sad mistake is frequertly made in considering the climate of our neighboring continent. Because it is called " South " America, the general supposition seems to be that it is all hot ! A look at the map appears to support this theory. A large portion of the northern end is wholly in the tropical zone, and the equatorial circle passes across northern Brazil and Ecuador. Probably, however, it is not remembered, except by special travelers and expert authorities, that vast sections of Colombia, Venezuela, Ecuador, Peru, and Brazil possess wide-reaching high plateaus where, on account of the elevation above the sea, the climate is as cool the year round as that of our Southern States in October. The temperature is so equable and favorable that there can be grown all the products of the Temperate Zone. Altitude effects a very remarkable physical phenomenon in climate. For instance, if a man standing on the equator at sea level mounts a mule and rides straight up into the mountains for 5,280 feet, or 1 mile, he will experience as great a change of temperature and vegetation as if he traveled 1,500 miles due north by land or sea ; if he continues on higher to the plateaus of 10,560 feet altitude, or 2 miles up, he will find a difference as great as if he journeyed 2,500 miles north on the surface of the earth. MULE BACK ALONG STRANGE ROUTES. Last summer (1906) it was my experience, in company with Mr. Mahlon C. Martin, jr., of Glen Ridge, New Jersey, to make one of the longest journeys over untraveled routes that has ever been undertaken by any American official in South America. At the time I was United States minister to Colombia and stationed in Bogota, its remote but interesting capital. Partly in an effort to comply with Secretary Root's instructions to meet him on the west coast of South America during his famous tour of that continent, partly from a desire to study carefully a vast unknown section of South America that will have a great development after the completion of the Panama Canal, and considerably from a spirit of adventure and in quest of strange scenes, I covered, including detours, a distance of 1,500 miles over the high summits and plateaus and through the tropical valleys and deep canyons of the main ranges of the Andes Mountains. Of this 1,500 miles, more than 1,000 were traversed on mules by thirty-one days of continuous sticking to the saddle. The rest of the distance we traveled in railroad trains, steamboats, canoes, afoot, and in automobiles. Not infrequently we would break camp in the morning at an altitude of 10,000 feet and regret that we were not clad like arctic explorers. By noon we would be lunching under a palm tree with monkeys chattering about and filling us with envy that we were not dressed as sensibly as they. At night we would have climbed up again and sought rest almost under the shadow of perpetual snow. During this one day's journey we had seen growing the vegetation of both Montreal and Panama, and had passed through as many stages of climate and classes of products as we could in a two weeks' trip to and from Canada and the Isthmus. The country we crossed, from Bogota to Guayaquil, by way of Quito, in Colombia and Ecuador, now has a population of 1,000,000, largely Indians descended from the Incas. Within a decade after the Panama Canal is constructed, these uplands and valleys should experience a special exploitation, for they could easily support a white population of 5,000,000 and are splendidly rich in both agricultural and mineral possibilities. THE STORY OF COMMERCE AND TRADE. The foreign commerce of South America tells a convincing story. It shows us that the field is of critical importance to our manufacturers and exporters. It proves that South America has awakened to a new life, and is buying and selling like any prosperous part of the world. The total foreign trade — exports and imports — of the ten independent South American republics — Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguy, Peru, Uruguay, Venezuela — and of the British, French, and Dutch Guianas, exceeded in 1905 the sum of $1,200,000,000. Now, if we study the long list of exports and imports of these countries and consider the geographical relations of the same countries to the United States, we say that the latter's share of this trade ought to have been at least $500,000,000. In fact, it was under $250,000,000, with a balance against us of nearly $1,000,000 in the value of their exports over their imports. This situation alone shows that we are not mastering the opportunity as we should, and that Argentina's record in material progress rivals Japan's. With only 6,000,000 inhabitants, Argentina astonished the world by conducting in 1906 a trade valued at $562,000,000— buying and selling more in the markets of foreign nations than Japan with a population of 40,000,000 and China with 300,000,000. Surely these are figures and results which should make us stop and think. Of these $560,000,000 in foreign trade, the portion of the United States was only $52,000,000. Brazil sold to the United States in 1905 coffee and other products worth nearly $100,000,000, but bought our exports only to the small value of $15,000,000. Something is wrong here, and the situation is emphasized when we note the heavy purchases from or in Europe. Chile engaged (1905) in a foreign commerce worth $140,000,000, but the allotment of the United States was only $17,000,000. Of almost every other South American country we might sing the same song. There are now nearly 50,000,000 people living south of the Panama Canal, or a population equal to that of the German Empire. Immigration is pouring rapidly into Argentina, Brazil, Uruguay, and Chile. As admission to the United States becomes more strict, the tide will turn to South America. As it is, nearly 500,000 Italian and Spanish immigrants landed at Buenos Aires during the past year. The totals at Rio de Janeiro, Montevideo, and Valparaiso were, of course, much smaller, but they indicated a marked increase in the number of people leaving southern Europe to seek new homes in southern and middle South America, where the climate is not at all dissimilar to that of their home countries. While the Spanish language is the common tongue of all South America except Brazil, it must be remembered that the latter has a population of nearly 20,000,000 and occupies nearly half the area of the continent. Portuguese is spoken throughout its limits, and Spanish is seldom heard among its people. The languages are similar but difficult for the same person to understand, unless the ear is carefully trained to the sounds and inflections of both. All well-educated persons in Spanish and Portuguese America speak and read French almost as well as their native tongue. It would be fortunate if more Americans would try one of three or four trips to South America instead of always running over to Europe or seeking Japan and India. The best general route would be to go down to Rio de Janeiro, Montevideo, and Buenos Aires on the Atlantic coast, cross to Santiago and Valparaiso, and then come up the Pacific coast by way of Lima and Panama, and thence to New York. Such a tour could be made in three months, but it would mean rapid movement. There are fast, capacious, handsome passenger and mail steamers leaving Southampton, Hamburg, Cherbourg, Lisbon, or Marseilles for Rio and Buenos Aires at frequent intervals; but there are no first-class, large, rapid passenger and mail boats flying the American flag and running from New York or other North American ports direct for the east coast of South America. It is true that there are several foreign lines of semicargo and regular freight steamers, but they do not answer. There must come an improvement in steamship facilities between the United States and Brazil and Argentina, if the United States is not to be distanced in the race with Europe for trade. 88812—09 3 SOME MISTAKES OF THE PAST. If the question were asked : " Why have we not made more progress with our prestige and trade in South America in the past?" it might be said that we have not appreciated and studied South American peoples, nations, governments, habits, and customs as they deserved. There has been a tendency to look down upon our sister republics. Difference in language and lineage has also worked against us. Instead of our mastering Spanish, Portugese, or French, we have expected them to understand our English. We have always approached South America on the material side and discussed opportunities for making money without endeavoring to get into closer touch along intellectual, literary, and educational lines, to which South Americans establishment of the Empire. The building is remarkable for its size and imposing architecture. give great attention. We have neglected to realize that their history teems with the exploits of patriotic heroes and with the names of brilliant authors, philosophers, and poets of whom we have no knowledge. Then, we have taken little note of the universities, hospitals, training schools, literary circles, newspapers, libraries, art and scientific museums, which, in proportion to population and opportunity, rival those of North American cities and capitals. The presence now in South America of Professor Moses, of the University of California; of Professor Rowe, of the University of Pennsylvania; and the prospective visit of Professor Shepherd, of Columbia University, following close on the journey of Secretary Root, will be productive of great good in inaugurating a new era of intercourse and relationship. One of the principal influences that helped to make the mission of Mr. Root a thorough success was the recognition by South Americans of a great intellectual force and noble, statesmanlike character in him that was far above the consideration of barter. They saw in him a man who stood for the best in American contemporary life, and they gave him a welcome that could not have been surpassed in spontaneity, magnificence, expense, and effect, if he had been President Roosevelt or King Edward. Through his speeches, manner, and personality, Secretary Root accomplished more, in the three months which he spent encircling South America, to bring about a new era of Pan-American confidence and good will than all the diplomatic correspondence and all the visits of promoters and exploiters in a century. South America is undoubtedly entering upon a new industrial and material movement. Its development during the next ten years will arrest the attention of the world. Its mining wealth and resources alone, especially those of gold, copper, silver, tin, platinum, and nitrate in the Andean States of Colombia, Ecuador, Peru, Bolivia, and Chile, will require the investment of North American capital not unlike that already needed in Alaska and Mexico. If, as statistics certify, $700,000,000 of North American money have been placed in Mexico, there will be room for many billions throughout the immense territory of all Latin America, from Mexico and Cuba to Argentina and Chile. There is no limit to the demands upon capital for legitimate railway building, but the requirements for electric tramways, electric lights, for utilization of water powers, for the erection of factories, water-supply plants, sewerage works, telephone and telegraph systems, for agricultural extension, stock raising, and kindred undertakings, offer innumerable attractive opportunities for the personal or combined action and interest of North Americans. It is my desire to interest every banker and investor in the United States in the industrial and material development of Latin America. For American capital it is a great undeveloped field. It has vast potentialities which are not appreciated. There is no time to be lost. Latin America is on the verge of a forward movement that will astonish the world. Unless American capitalists are up and doing, those of Europe will control the situation and reap the chief benefits. This is no frightened cry of alarm. It is no despairing shout. It is not a pessimistic wail. On the other hand, it is a simple statement of truth, based on a careful study of Latin America and a diplomatic experience in many of its principal countries covering some six years. I do not ask that heed be given to my story because I tell it, but simply because it narrates facts that any man of common sense, who is familiar with conditions in Latin America, can relate and prove as well as I. Without appearing to lay stress on my personal views, but in order to create confidence in my humble observations, I would recall that a dozen years ago, when I had the honor to be United States minister to Siam in Asia, I made similar prophecies in regard to American commercial and material opportunities in the Orient. These were first ridiculed and even scorned by many of the leading American newspapers. To-day the realization is far beyond what was pictured in my most hopeful descriptions. I have studied Latin America, from Mexico and Cuba to Argentina and Chile, no less carefully than I did Asia, from Japan and China to the Philippines and Siam, and I am now convinced of the truth of all my conclusions. PRESENT AND PROSPECTIVE INVESTMENT. There is no better argument in favor of the importance and value of the Latin American opportunity than a citation of what is being done to-day. Mexico, Central America, and Cuba can be passed over with brief references, because they are so much better known in the United States than is South America proper. It is well to remember, however, in passing that, according to the opinion of Senor Don Enrique C. Creel, the distinguished ambassador (1907) of Mexico in Washington, and a man who stands high both in financial and diplomatic circles of that Government, over $700,000,000 of money from the United States are invested throughout his country. This shows how eagerly the capital of the United States will seek Latin nations if peaceful conditions prevail. It is a logical conclusion that if this sum is invested in Mexico, there is room for ten times that amount, or $7,000,000,000, to be placed in South American countries from Colombia to Chile. Of course, I do not mean that this sum can be put in all at once ; but there will be a demand and opportunity for it during the next twenty j^ears if the investors of the United States do not let those of Europe take the best chances first. The other day a reliable financial paper in Europe made the significant statement that $2,000,000,000 of European capital would be invested in South America in various enterprises during the next ten years, and that many of the great financial institutions of Europe were seriously beginning to believe that capital was safer in South America than in the United States. Of this point, in so far as it refers to revolutions, I shall speak pointedly a little later on. THE CARIBBEAN AND CENTRAL AMERICAN STATES. In Cuba, already over $150,000,000 of American money are invested. In Porto Rico, Dominican Republic, Haiti, and the Central American States of Guatemala, Honduras, Salvador, Nicaragua, Costa Rica, and Panama are $50,000,000 more — and yet all experts who have studied these small countries agree that the development of their resources has only begun. They may be in a somewhat disturbed state, but there is a strong sentiment growing among all of them against revolutions and in favor of permanent law and order. Some people describe the present trouble in Central America as the straw which will break the back of the revolutionary camel and inaugurate a new era of peace and prosperity. OTJR NEAREST SOUTH AMERICAN NEIGHBORS. Now, coming to South America proper, we have a fascinating field of study. Let us first glance at Colombia, our nearest neighbor, and yet perhaps the least known of the countries on the South American continent. Its Caribbean ports are only 950 miles from Florida. It is closer to New York, Boston, and Philadelphia than Panama and most of the Central American States. It covers an area as large as Germany and France combined. Possessing a marvelous variety of climate from the temperate cold of the wide plateaus of the Andes to the tropical heat of its lowlands, rich with a remarkable variety of minerals, producing almost every important vegetable and timber growth, and yet in the very infancy of its foreign development and exploitation, it is most tempting for capitalists looking for virgin fields. Although Colombia has had the name of being disturbed with internal strife in the past, it is nowr, through the wise administration of its President — General Rafael Reyes — gradually substituting confidence and quiet for distrust and conflict. General Reyes is doing all in his power to interest foreign capital in the exploitation of the resources of Colombia. He wants to build trunk and branch lines of railroads over its wide area ; to open up its mines of gold, copper, and platinum ; to improve the navigation of its many rivers ; to carry to market the valuable timber of its primeval forests ; to put in electric light and street-car lines in its principal cities, and to take advantage LANDING WHARF AT PUERTO PLATA, DOMINICAN REPUBLIC. Puerto Plata, on the north coast, ranks next to Santo Domingo in commercial importance. The town itself is not a large one, the population being about 6,000, but the harbor affords splendid anchorage for a large fleet of ocean-going vessels. It is a prominent shipping point for products of the Republic, and is the natural outlet for the northern provinces. of its numerous water powers. When I was recently United States minister in Bogota, its capital, one of the most conservative representatives of a great English banking house told me that Colombia alone could give profitable investment during the next ten years to $25,000,000 of foreign money. THE RICH LAND OF THE ORINOCO. Venezuela may seem a little disturbed at times, but those familiar with its interior agree that, in proportion to area, no other South American country has a more extended variety of resources capable of profitable development. One trip up the mighty Orinoco River and its tributaries will convince the most skeptical that millions of dollars are to be made in taking advantage of what nature has given Venezuela in prodigal supply. Like Colombia, it is almost a terra incognita to the American capitalist or traveler when he gets beyond the Caribbean coast. With these two republics crossed by trunk lines of railroads, with branches into various valleys and upon their high plateaus, they would enter upon a new era of prosperity hardly contemplated at present. THE COMMON MISTAKE REGARDING THE TROPICS. I am here reminded to emphasize the mistake that the average North American makes when he classes countries like Colombia, Venezuela, Ecuador, Peru, and Brazil as purely tropical and therefore dangerous for men of the United States and Europe if they expect to spend much time there. It is altitude above the sea rather than nearness to the equator that determines heat or cold. A man who climbs up from the tropical sea level to 5,280 feet, or 1 mile, upon a plateau, finds it cooler and more temperate than if he travels 1,500 miles north or south from the equator. Again, if he goes up 10,560 feet, or 2 miles, upon any one of the numerous high plateaus of the Andes, he will find a far more agreeable and equable climate than if he journeyed 2,500 miles north or south from the equatorial line. What does this suggest? Simply that the so-called and muchdespised tropical section of South America, having many large and cool areas wonderfully mingled with low tropical valleys, all of which are characterized by exceptional fertility of soil and variety of resources, will experience an astonishing development when capital realizes the opportunity and feels that it is safe. Ecuador, which looks small on the map, but which is big enough to include writhin its area several^ Pennsylvanias, is a good illustration of this point. Through its entire length for many hundred miles there are fertile, populous Andean uplands, in the center of which is located its capital, Quito. In a short time a railroad built by an American in the face of great financial and engineering difficulties will connect at Guayaquil, its port on the Pacific, with Quito, first traversing in this distance the rich tropical lowlands and then climbing up into the mountains. This road, together with one in Colombia, which is being built from Buenaventura, on the Pacific coast, into the famous and beautiful Cauca Valley, will form important divisions in the mighty Pan-American Railway system which is being so strongly advocated by ex-Senator Henry G. Davis, of West Virginia, Andrew Carnegie, and others. THE RICHES AND PROGRESS OF GREAT BRAZIL. When one speaks or writes of Brazil he has difficulty in finding adjectives which will describe truthfully the opportunities in that country for legitimate exploitation of North American capital and yet which wall not suggest the use of exaggerated phraseology. The simple facts — that Brazil covers a greater area than the United States proper; that out of the Amazon River every day flows three times more water than out of the Mississippi; that this gigantic stream is navigable 2,000 miles for vessels drawing 25 feet of water; that the city of Rio de Janeiro, its capital, has now a population of 900,000, and spent more money last year for public improvements than PUNTA ARENAS, CHILE, ON BRUNSWICK PENINSULA, TERRITORY OF MAGELLAN. This is the southernmost city of the globe and coaling port for steamers passing through the Strait of Magellan. It was formerly a penal settlement but is now an enterprising commercial city of 10,000 inhabitants and the leading port in southern Chile for the export of fur, wool, and minerals. any city of the United States excepting New York; and that to-day the central Government and the different States are expending larger sums for harbor and river improvements than the Government or ^States of the United States — all convince the most skeptical that Brazil is a field for the investor to study thoroughly and thoughtfully. Only recently it was announced that a celebrated American engineer who designed the elaborate dock system at Buenos Aires, in the Argentine Republic, had secured a concession for building a great harbor at Rio Grande do Sul, in the south of Brazil, and would expend over $14.000,000 on the project. Plans for the construction of railways into the heart of the country, including one that will eventually connect Bio de Janeiro with Montevideo, the capital of Uruguay, on the south, and with Asuncion, the capital of Paraguay, on the southwest, are well under way. The navigation of the upper branches of the Amazon River are to be so improved that there will be connection by rail with Lima, on the Pacific side, and with La Paz, the capital of Bolivia, located in the central Andean plateau. All over Brazil new towns and cities are springing up which will require water works, electric lights, sewerage systems, and street-car lines. Back in the interior, which has heretofore been described as a jungle, are being found mountains of iron and coal and forests of valuable timber, upon which the world must largely draw for its supply in the future. Over 1,000 miles up the Amazon is the thriving city of Manaos, which reminds one of the pushing western cities of the United States. It is now looking forward to a population of 100,000, and prides itself on its fine streets, business buildings, street-car service, and handsome opera house. If the traveler will go another 1,000 miles up this great stream he will arrive at Iquitos, the Atlantic port, as it were, of Peru, a city which is growing as a rubber market, although its neighborhood a few years ago was considered a rendezvous of savages. Without enlarging on the possibilities of Brazil to supply the world's demand for rubber and coffee, so well known in the United States, it can be said that this Empire Republic of South America offers a field for safe investment of $200,000.000 of American money in the near future. AMERICAN CAPITAL BUILDING NEW RAILROADS. It is regrettable that there is not space in this article to go into details about such important countries as Uruguay, Paraguay, Peru, and Bolivia, but a few points must be kept in mind. Chiefly through the influence of the able minister of Bolivia in Washington, Mr. Ignacio Calderon, nearly $100,000,000 of American capital will be invested in the construction of Bolivian railways, which will result in bringing her limitless mineral resources and their consequent exploitation directly to the attention of the world. In Peru the greatest mining enterprise is in the hands of Americans, and they declare that they have only scratched the surface. The millions that the Haggins have put, and are putting, into the copper deposits of the Peruvian Andes are evidence of their value. Paraguay seems to be tucked away in the interior of South America so that its agricultural and timber wealth are not appreciated, but every consular report that comes from Asuncion shows that the Paraguayans are anxious to encourage the investment of North American money. In Uruguay we find one of the most fertile soils in all the world and a thrifty people ; and as evidence of Uruguay's forward movement it can be cited that CHILE A SCENE OF GROWING ACTIVITY. Where to begin or end in a description of Chile's material and industrial possibilities is difficult to decide. That Europe has confidence in its future is proved by the eagerness with which German and English capital is seeking investment along numerous different lines within its limits. Reaching for over 2,500 miles along the Pacific coast of South America and having a wide variety of climates, products, and natural resources it presents an extremely inviting opportunity. Its harbors are being improved, its railroads are being extended, and its cities, especially those injured by earthquakes, reconstructed. The Chilean Government expects to spend at least $10,000,000 in making Valparaiso a safe harbor. THE PROSPEROUS ARGENTINE REPUBLIC. Last, but undoubtedly far from least, we consider the Argentine Republic, some times called the " Wonderland " of South America. Located to the south of the equator not unlike the United States north of it; possessing through its greater portion a temperate climate ; covering an area as large as that section of the United States east of the Mississippi River plus the first tier of States west of it; drained by the great River Plate system, out of which flows twice as much water each day as out of the Mississippi;- and boasting a capital city, Buenos Aires, which has a population of over 1,200,000 and is growing faster than any other city on the Western Hemisphere, excepting New York and Chicago, the Argentine Republic says today to capitalists, investors, and bankers of the world that they have no more inviting field for the secure placing of their surplus money. Business " talks," and it speaks loudly and convincingly in regard to the Argentine Republic. There can be no more logical argument in support of Argentina's claim to commercial importance than the fact that in the year 1906 it carried on a foreign trade, exports and imports, amounting, in all, to the magnificent total of $562,000,000. This, though true, seems almost incredible when we realize that the country has yet only about 6,000,000 people. It means that her trade with the rest of the world is nearly $100 per head, or proportionately greater than any other large country on this earth. The railway systems of this Republic, which connect Buenos Aires with Bolivia on the north, with Chile on the west, and with Patagonia at the southern end of Argentina, rival, in proportion to population, the railroad systems of the United States and European countries. The cities of the interior are growing rapidly, and there is every- where a demand for capital to give these towns modern advantages. The amount of money required not only to do this but to improve the vast agricultural possibilities of her plains and the mineral wealth of her mountains should be supplied, in a considerable part, by the United States. Misti Volcano, 19,200 feet high. for the establishment of North American banks, or branches thereof, in the principal cities of South America ; for floating government and industrial loans; for the building and extending of railroads; for the construction of electric rail and street-car lines, electric lighting plants, waterworks, sewerage systems; and for financing concessions covering harbor improvements, agriculture, timber, and mineral exploitation, not to mention a score of lesser opportunities that combine to make a general onward movement. REVOLUTIONS AND ACTUAL COMMERCE. As for revolutions, I desire to emphasize the fact that capital must not be frightened or misled by occasional outbreaks in some of the lesser Latin American countries. The truth is that four-fifths of South America has known no serious revolutions in the last decade and a half, while the present prospects for lasting peace and prosperity are better than ever before. The query as to what Latin America is doing in its relations with the outer world can be summed up in the gratifying and surprising statement that the total foreign trade, exports and imports, of Latin America in the year 190G were valued at $2,035,350,000. Of this amount, exports were $1,138,260,000, and imports, $897,095,000, leaving a remarkable balance in favor of South America of $241,165,000. In conclusion, I wish to take advantage of this opportunity to call the attention of capitalists, investors, bankers, and business men in general to the broadened scope and plan of the International Bureau of the American Republics, which, under the ambitious programme outlined by the Third Pan-American Conference, held at Rio de Janeiro, Brazil, in 1906, is being reorganized and enlarged so as to become a world-recognized and powerful agency not only for the extension of commerce and trade but for the development of better relations of peace and friendship among all the republics of the Western Hemisphere. The impetus given to this plan by the extraordinary visit in 1906 of Elihu Root, then Secretary of State of the United States, to South America, can not be overestimated. He accomplished more in his three months' journey, by his contact with the Latin American statesman, by his speeches, and by his personality, to remove distrust and to promote mutual good will, confidence, and their corollary, commerce, than all the diplomatic intercourse and correspondence of the preceding seventy-five years. As a result of Mr. Root's visit to South America, a new era has already dawned in the relations of the United States with her sister nations, and it now remains for the capital of this country, accumulated through our past prosperity and looking for new fields, to improve the wonderful opportunity in the great southern continent. 88812- The best way to understand or study any section of this world which may be little known is to locate it on the map clearly and then make comparisons as to its size with sections better known. Central America is sometimes described as all that portion of the North American continent lying between the Rio Grande and the Atrato rivers, the former dividing Mexico from the United States and the latter forming practically the boundary line between Panama and Colombia. Politically, however, it comprehends the five independent states of Guatemala, Honduras, Salvador, Nicaragua, and Costa Rica. In the order named, they lie directly south and east of Mexico, between the Caribbean Sea and the Pacific Ocean. Salvador is the only one of the five that borders solely on the Pacific, or that has not shores washed by both waters. As the average newspaper reader sees the names of these republics mentioned in the dispatches he thinks of them as indefinitely existing somewhere to the distant south of the United States. He believes that they are nearer Mexico than Patagonia, but he hesitates before he goes on record to that effect. In fact, all these countries, grouped as Central America, are so close at hand that they are within a few days' steaming of New Orleans, Mobile, or Galveston. They are much nearer geographically to our Gulf coast than Panama, which, on account of the advertising it has enjoyed from the canal, now seems only a few hours from New York. Panama, as it looks on the map, should belong to Central Americait certainly is not part of South America. Having formerly been a portion of Colombia, the greater part of which is in South America proper, it naturally has never been classed as belonging to Central or North America. APPROACHES TO CENTRAL AMERICA. A strong influence that has worked to make Central America seem far away has been the necessity, in the past, of reaching the different capitals or principal cities either by sailing from San Francisco on a journey occupying from ten days to two weeks down the Pacific coast past Mexico, or by crossing the Isthmus of Panama and proceeding north. The physical conformation of Central America is such that the high and accessible lands suitable for cities and the better classes of population are much nearer the Pacific Ocean than the Caribbean Sea. The shores and the interior facing on the latter sea are generally low, and, until recently, when banana cultivation began to open them to the world, they were a wild, swampy, mosquito jungle. The few railroads have started from the Pacific coast and wound their way to the capitals and commercial centers, but now rapid progress is being made toward rail connections with the Caribbean side. Costa Rica is already well provided in this respect, and its beautiful capital of San Jose is easily reached in half a day's ride through impressive scenery from Port Limon. Guatemala hopes to have its railroad to the Gulf of Honduras completed next fall.0 Nicaragua is planning a line that will connect the Caribbean Sea with its great interior lake, while Honduras has begun a road that is destined to provide an approach on the same side to Tegucigalpa. In a few years it should be possible to cross by rail each Central American country from sea to sea. An era of continued peace, which ought to be at hand, would see this desired condition of communication soon accomplished. Very few people have a correct impression of the size of Central America as a whole or of its States, taken separately. California seems like a large State. It extends 770 miles along the Pacific and has an extreme width of 375 miles. If California were laid end for end on Central America it would cover it with the exception of Salvador, which is just the size of New Jersey and occupies a little over 7,000 square miles. Stated in another way, if Central America Avere lifted up bodily and laid down on our Atlantic coast it would just hide all New England, New York, Pennsylvania, and New Jersey. In short, it has a combined area of approximately 167,000 square miles. Individually, aside from Salvador, already mentioned, the States could be compared as follows : Honduras to Pennsylvania, 45,000 square miles; Guatemala to Mississippi, 47,000; Nicaragua to New York, 49,000; Costa Rica to Vermont and New Hampshire, 18,000. Data as to the population of these States are somewhat contradictory, but the official figures given to the International Bureau of American Republics by the diplomatic representatives of these countries at Washington are here used. Guatemala heads the list with 1,364,678 people. Then come Salvador, with 1,006,848; Honduras, with 543,741 ; Nicaragua, with 423,200 ; and Costa Rica, with 331.340— a grand total of 3,671,807. This nearly exceeds that of either Texas or Tennessee, and is about twice that of California. Such a population should disabuse the minds of many persons that Central America is a sparsely settled, savage land. Of course, there are considerable portions of the lowlands and along the seacoasts where the inhabitants are few, and even these live in most primitive manner, but on the plateaus and higher sections of the interior are cities and towns of advanced civilization, with up-to-date features of municipal life, and an agricultural population that leaves little valuable land unoccupied. CONDITIONS OF POPULATION AND DEVELOPMENT. It is a surprise to the man who has not studied Central America to learn that Salvador, with only 7,000 square miles, has more than 1,000,000 inhabitants. This indicates a density of population far greater than that of New Hampshire or Vermont, and means that there are not many " deserted farms " for sale in Salvador. Guatemala, with an increasing population that, since the last census, has probably now reached nearly 1,500,000, can not be regarded as a land of untra versed jungle, for the density of population is greater than that of Louisiana. Honduras has the largest area of unused country, with Nicaragua next, but the development of the banana industry and the demand for valuable timber grown in the low interior sections are destined to make every unknown part accessible and open to exploitation. Too strong emphasis can not be placed on the varied riches and possibilities of these five republics. Taken as a whole, they possess more agricultural and timber wealth than mining potentialities, but they are developing rapidly along all three lines in a way to prove that they have not been appreciated heretofore, either in Europe or in the United States. The number of recent disturbances in Central America has given the impression abroad that these nations are always in a state of strife, and hence that commerce and material progress have little to encourage them. A consideration, however, of the figures of their foreign trade with the world at large, and with the United States in particular, demonstrates that despite warlike struggles at frequent intervals they have time and money to do a very fair business with the outside world. CLIMATIC CHARACTERISTICS OF CENTRAL AMERICA. People are always asking, What is the climate of Central America ; is it not unfavorable to North Americans or to persons accustomed to a temperate climate? Were the entire area of Central America similar to the part along the Caribbean coast I should be inclined to speak disparagingly of it, but it must be remembered that large sections are located either at such an altitude or in such relation to prevailing winds that the temperature seldom becomes too hot for ordinary comfort, and never too cold. Even in the lower and socalled fever, malarial, and mosquito districts, it is wonderful what a change can be wrought by clearing away the jungle, providing good sewerage and pure water, and generally developing a sanitary environment. Then, the terrors of excessive heat seem to disappear and the Tropics become a source of delight. What has been done at Panama can be duplicated everywhere in Central America if the same methods are employed. There is hardly a depressing, forbidding port of Guatemala, Honduras, Salvador, Nicaragua, and Costa Rica which could not be made healthy and habitable for foreigners if a well-developed plan for sanitation were carried to complete execution. This is sure to come some day, with the result that the whole so-called " Mosquito Coast " and the remainder of the Caribbean shore of Central America will be busy with prosperous commercial entrepots, which, in turn, will be connected by railroads with all parts of the hitherto impenetrable jungle, as well as with the mountain capitals and towns. In fact, I look to see, during the next twenty years, a transformation in Central America which will astonish the world and make it difficult to realize that, in 1907, it was commonly regarded as a terra incognita, HOW TO REACH CENTRAL AMERICAN CITIES. The query is often propounded to the International Bureau of American Republics: How does a visitor go to the principal cities of Central America, and what are the conditions of travel? The best way to-day to reach San Salvador, the capital of Salvador; Teguci- GOVERNMENT PALACE, MANAGUA, THE CAPITAL OF NICARAGUA. galpa, the capital of Honduras, and Managua, the capital of Nicaragua, is either by the way of Panama and the Pacific or by San Francisco and the Pacific, except that the new rail route across the Isthmus of Tehuantepec may presently provide connections that will be quicker than the route via San Francisco or Panama. San Jose, the capital of Costa Rica, has direct rail connections with Port Limon, on the Caribbean shore, and will soon have a through railroad to Puntarenas, on the Pacific Gulf of Nicoya. The Pacific port of Guatemala City is the town of San Jose, from which a railroad runs to the capital. The line from the Caribbean, about completed, begins at Puerto Barrios. Northwestern Guatemala is reached through the ports of Ocos and Champerico, and a raiJroad extends from the latter place to several important towns of the interior. The principal port of Salvador is Acajutla, from which a railroad carries one, in five hours, to the city of San Salvador. From La Libertad there is a fair mountain road, but it has been little used since the railway was completed. The capital of Honduras has its port at Amapala, on the Pacific Gulf of Fonseca, and a good macadamized road extends from San Lorenzo to Tegucigalpa,, on which automobiles are operated. A railroad is planned and partly constructed to connect Tegucigalpa not only with the Gulf of Fonseca, but also with Puerto Cortez, on the Caribbean Gulf of Honduras. When these roads will be completed is, however, uncertain. The chief port of Nicaragua is Corinto, on the Pacific side. From this port a railroad runs to Managua and thence to Granada, on Lake Nicaragua. PRECAUTIONS FOR TRAVELERS. The capital towns of the Central American republics vary in population, but all provide hotels and clubs that are comfortable. New York and Paris hostelries do not abound, as there is no demand for them, but unless a man is a chronic " kicker " he need not be unhappy in his Central American surroundings. Whoever goes there should be provided with an abundance of light clothing, such as white duck, brown khaki, or thin flannel. He must guard against the sun in the middle of the day, and should wear, unless he carries an umbrella, a pith hat or some kind of sun helmet. After the sun is well down, the air cools off immediately, and the nights are generally cool. Except in the higher altitudes, a mosquito net is absolutely necessary, and no traveler along the coast or in the low interior should be caught without one. If any time is spent in this section, it is also well to take regular doses of quinine, according to one's capacity or health, in order to guard against malaria. Ordinary care should also be exercised in the kind of food consumed, and even more care in the kind of water that is drunk. I do not wish to frighten anybody or make it appear that there is any particular danger while traveling in these countries. I desire rather to make a few simple suggestions which, if followed, will make travel and life there more safe and agreeable. As to myself, I can say that during many years' residence as United States minister in different tropical countries of the Orient and America, including a year at Panama (before it was made healthy and sanitary through the great work of Colonel Gorgas), I never experienced a day's sickness from any kind of tropical complaint. I exercised common sense care of myself, and nothing more. To-day, I visit the heart of the Tropics with far less hesitation than I do New England in winter. STATUE OF COLUMBUS, GUATEMALA CITY, GUATEMALA. This celebrated monument of the great Discoverer adorns Central Park. The artistic composition of the figures and the bronze globes is most happy, while this park, with its wealth of semitropical vegetation and its commanding and picturesque location, forms a fitting background. TRADE, COMMERCE, AND FINANCIAL STATUS. That this discussion of Central America may contain some exact information about its trade, commerce, and general business, the latest statistics and figures, prepared in the International Bureau of the American Republics, of which the writer is the director, are given in summarized form. The total foreign commerce, exports and imports, of the five Republics amounted last year (1906) to the considerable total of $56,133.000. Of this, exports were $32,170,000 and imports $23,963,000, or a favorable balance of nearly $10,000,000. The share of the United States in the above trade is interesting to note, because it averaged about half. The total was $26,376,000, of which exports Taking each country in turn for the purpose of providing accurate and specific information, it is noted that the total trade of Guatemala with the world is $15,082,000, of which $6,844,000 are imports and $8,238,000 are exports. Of this, the portion of the United States is $5,582,000, divided as follows : Imports, $2,707,000 ; exports, $2,875,000. The budget for 1906-7 estimates the revenues of the Government at $25,000,000. Honduras conducts an external trade^with the world of $7,857,000, of which exports are $5,564,000 and imports $2,293,000. The United States proportion of this trade is valued at $6,322,000, or much the largest part, of which exports to the United States are $4,632,000 and imports therefrom $1,690,000. The last budget places the revenues at $3,043,000. Although the foreign debt is heavy, Honduras has marvelous resources, which, developed, will enable her to meet her obligations. Nicaragua's foreign commerce reaches a total of $7,128,000, of which $3,926,000 represents exports and $3,202,000 imports. Of these, the share of the United States is nearly half, as the total is $3,757,000, with exports at $2,089,000 and imports -at $1,668,000. The annual income for government expenses is about $20,000,000. Nicaragua gives every evidence of being on the highway to great material progress, and is offering exceptional opportunities for the investment of capital in both mining and agriculture. Great public improvements are also contemplated that will add much to the prosperity of the country. Although Costa Rica ranks fourth in area among the Central American republics, she stands a good second in foreign trade. This amounted in 1906 to the large sum of $16,000,000, of which the exports were $8,802,000 and imports $7,278,000. The United States shared to the extent of about half, or $8,135,000, with exports and imports, respectively, at $4,171,000 and $3,964,000. The revenue for 1906-7 is estimated at $3,372,795. Everybody wrho visits Costa Rica carries away a good impression and has great confidence in its future. The banana business has grown to such size that it has become a decided source of wealth to the country and people. Mining has not been conducted on a large scale, but considerable mineral wealth is believed to exist in the mountains. PRINCIPAL PRODUCTS SOLD AND BOUGHT. The character of the trade of Central America with the world and with the United States can be best appreciated by noting some of the principal articles which are exported and imported. Central Americans sell abroad coffee, bananas, rubber, cacao, dyewoods, valuable lumber, like mahogany and other cabinet woods, hides and skins, rice, sugar, indigo, balsam, tobacco, and minerals. They buy cotton and woolen cloth, machinery, railway, electric, and mining outfits, wheat flour, drugs, and medicines, iron and steel manufactures, sacks for export of coffee and fruit, canned provisions, and a host of lesser articles. The list is long enough to show that there are great opportunities in Central America for the manufacturers and exporters of the United States if they will make vigorous efforts to exploit it along legitimate lines. As this trade will next year reach a high figure, it should be carefully investigated by all those interested. The principal centers of trade and industry in Central America include Guatemala City, which has 96,000 people; Coban, Toonicapan, and Quezaltenango, in Guatemala, with about 25,000 each; Tegucigalpa with about 34,000, and Comayagua with 10,000, in Honduras; Leon with 60,000, Granada with 30.000, and Managua with 25.000, in Nicaragua ; San Salvador with 60,000, and Santa Ana with 48,000, A national institution, which, together with the school of medicine, of engineering, and of philosophy, forms the university. These schools are supported by the Government and are under the direction of a board selected from the faculties of the four institutions. in Salvador, and San Jose with 25,000, Heredia with 10,000, and Limon with 7,000, in Costa Rica. Many of these towns are also seats of notable institutions of learning, such as the schools of law and medicine at Guatemala City, the Institute of Jurisprudence and Political Science at Tegucigalpa, the National University at San Salvador, the schools of law, medicine, and pharmacy at Managua and Leon, and the schools of law and medicine in San Jose. If anyone assumes that because there are occasional revolutions in Central America and the climate is somewhat tropical, there is not a considerable element of highly educated and refined men and women in the chief cities and towns, he labors under great error. A large proportion of the well-to-do people have traveled abroad and send their sons or daughters to the United States and Europe for educational advantages in addition to their home schools. Each country has produced writers, historians, poets, novelists, jurists, doctors, and surgeons, as well as statesmen, who are well known throughout all Latin America and who are becoming better known in the United States. The society found by the visitor in the Central American capitals is always more interesting and cultured than he expects to meet before he has acquired familarity with actual conditions. Guatemala City, for instance, is a remarkable capital, with nearly 100,000 people, which will become a popular point for travelers and tourists from the United States when the Pan- American Railroad or the new line from the Caribbean shore is completed. In fact, Guatemala has a splendid future before it, but the world has only recently begun to appreciate its resources and possibilities. Much might also be said of the conditions and attractions of the other Central American capitals, like San Jose, Managua, Tegucigalpa, and San Salvador, but there is not space in this brief article. BENEFITS OF AN INTERCONTINENTAL RAILWAY. No matter how many steamship lines may be put in operation between the Pacific, Gulf, and Atlantic ports of the United States and Central America, the principal cities and points of this section of the North American continent will never be reached rapidly and by large numbers of people until the Pan-American Railway system is constructed from Mexico down through Guatemala, Salvador, Honduras, Nicaragua, and Costa Rica to Panama. The line now reaches practically to the border of Guatemala, and there are no insurmountable difficulties in connecting it wth the small systems already in operation, or in course of construction, in these different states. If the movement which has been so strongly urged by exSenator Henry G. Davis, of West Virginia, and which has been approved by the different Pan- American conferences, is carried to a consummation, it will be one of the greatest forward steps to PanAmerican unity. In ten years, it should be possible for a traveler to start out from New York and make the journey to each of the Central American capitals in comfortable Pullman trains. For three hundred years Central America was under Spanish authority, beginning with the invasion of Pedro and Jorge de Alvarado on the north and Gil Gonzales de Avila on the south. The former came down from Mexico just before the latter came up from Panama, taking possession of what is now Costa Rica and Nicaragua. For long years, Central America was known as the Kingdom of Guatemala, with governors appointed by the Spanish Government. After their independence was consummated in the year 1821, and, until 1847, these countries remained as one republic. Since they separated there have been various efforts to unite them again into one nation, but none of these has been completely successful. THE BUREAU OF THE AMERICAN REPUBLICS. The International Bureau of the American Republics, in Washington, which has the twofold purpose of developing commerce and trade and of promoting better relations and closer acquaintance among all A RAILWAY TRESTLE IX COSTA RICA. The Pacific Railway of Costa Rica is 170 miles long, and only lacks 12 miles of construction in order to connect the Atlantic with the Pacific coast from Port Limon to Puntarenas by way of the capital, San Jose. It traverses one of the richest tropical and subtropical portions of the Republic, noted for the luxuriance of its vegetation and the beauty of its scenery. Some of the railways of Costa Rica are under direct governmental^control, and all of them penetrate exceedingly productive agricultural regions, capable of supplying an immense tonnage of natural and cultivated products. the nations of the Western Hemisphere, will be glad to answer any inquiries from the readers of the " Review of Reviews " about the resources, possibilities, and general development of the Central American republics which may be suggested by this brief description, while the able ministers in Washington and consuls-general in New York City of these countries are always ready to consider legitimate and serious questions from those who may be interested. 0 0 There is no field for the study of the American manufacturer more important than that of Latin America. At this very moment conditions demand the attention of all American business men who are interested in the expansion of the foreign commerce of the United States. The whole world is suddenly awakening to the vastness and variety of the resources and possibilities of the 20 republics which reach from Mexico and Cuba on the north to Argetina and Chile on the south, a section of the Western Hemisphere which includes every kind of climate, product, and people. Commercial countries of Europe, like England, Germany, France, Spain, Italy, and Austria, are devoting far more attention to South America than is the United States. Further than this, Japan, far away across the Pacific, is exerting herself to get into close touch with the west coast of South America. That statement may seem surprising, but proof of it is found in the projection of a steamship line which is to run from Japan to Chile, and by the arrangement of postal money-order exchange between the two countries, effective from January 1, 1908. The United States has done absolutely nothing toward improving its shipping relations with any portion of South America. The European countries already mentioned are favored in the development of their trade by numerous first-class mail, express, and passenger cteamers which connect their- leading ports with those of South America and even with Mexico and Central America, within the very limits of our own front yard, as it were. What a sad and depressing acknowledgment it is for us enterprising North Americans that there is not one single fast-mail steamer flying the American flag and running between the chief ports of the United States and those of South America proper. I am not making any argument for subsidy, but simply stating a fact. doubt the value of the Latin American commercial opportunity. The average manufacturer, merchant, and farmer of the United States has been so occupied, on the one hand, with home trade conditions or, on the other, with the possibilities of commercial expansion in Europe and Asia that he has almost overlooked the prosperous, progressive, and wealthy countries in our neighborhood to the south of us. He has not comprehended the essential truth that on the Western Hemisphere, aside from the United States, there are other great nations which have remarkable resources and which are making unusual progress. He has assumed too readily that the United PRINCIPAL PLAZA, BOGOTA, COLOMBIA. Plaza Bolivar is the principal square of the capital of Colombia. In the center of a garden of flowers, shrubs, and trees is a handsome statue of Gen. Simon Bolivar, the liberator of five South American Republics. The capital, municipal building, and cathedral are built around this square. States was the " whole thing," and that what was not going on in this country was hardly worthy of respect. Now he must rub his eyes and wake to see Latin America forge ahead, appreciated by the rest of the world while the average North American has been asleep. He who has not familiarized himself with Latin America does not stop to think that it conducted one-third of the total foreign commerce of the 21 republics of the Western Hemisphere, including the United States, during the year of 1906. It is hard for him to believe that these lands to the south of us bought from and sold to the rest of the world products valued at $2,000,000,000 and that, of this, there was a balance of trade in favor of Latin America amounting to approximately $228,000,000. For comprehensive and reliable discussion I have taken the average foreign trade of Latin America, covering Mexico, Central and South America, and the West Indies, for the last two or three years, and have drawn the following conclusions : LATIN AMERICAN EXPORTS AND IMPORTS ANALYZED. The total exports and imports of Latin America amount annually to $2,052,355,000; of this great sum, Latin America exports $1,140,260,000 and imports $912,095,000, giving, as indicated above, a remarkable balance of trade in its favor. Noting next what is the average share of the United States in this total with all Latin America, we find it to be $519,202,700, Avhich, subdivided, gives exports to the United States as $296,932,200 and imports from the United States $222,270,500, or a balance of trade in favor of Latin America and against the United States of approximately $74,000,000. These figures for all Latin America are more encouraging than for the subdivision of South America proper, which comprises the ten Republics of Brazil, Argentina, Uruguay, Paraguay, Chile, Bolivia, Peru, Ecuador, Colombia, Venezuela, and the British, Dutch, and French Guianas. Let us see what there is here unsatisfactory to the United States. South America proper conducted an average foreign trade amounting to $1,513,415,000, of which the share of the United States in 1907 was only $233,293,300, including both exports and imports— barely one-seventh. Analyzing further these figures for the United States, we discover that South America sold to us products to the value of $147,680,000 and bought from us only $85,612,400. This gives a balance against us of practically $60,000,000. Another comparison shows how far behind we are in the race with the rest of the world. South America purchased from other nations products valued at $660,930,000, of which the United States furnished $85,612,400, or barely one-eighth, and yet the more we study the South American field the more we appreciate that the United States could supply the greater portion of its imports. Correspondingly, we do not give South America as great a market for her products as we ought, for, of her total exports, amounting to $852,485,000, the United States purchased only $147,680,900, or approximately one-sixth. ENCOURAGING FEATURES OF THE SITUATION. Having given these figures, some of which are averages, covering a period of years, I now desire to point out, through additional figures, another feature of the situation which is most encouraging, and which should inspire our manufacturers and exporters to take advantage of the Latin-American commercial opportunity. With the aid of the Bureau of Statistics of the Deartment ^ Labor, the International Bureau of the American Republics' "fras worked out the following totals showing the growth of the trade of the United States with her sister republics: The entire commerce, exports and imports, between the United States and the countries to the south of her amounted in 1897, ten years ago, to $252,427,798. Three years later, in 1900, this had grown to $324,680,368. Five years more, in 1905, it had expanded to $517,477,368; while two years later, 1907, we are gratified to note that it has reached the splendid total of $587,194,945. It is thus seen that in ten years our trade with Latin America has increased by the vast sum of $335,000,000, or has more than doubled. Certainly this is a record of which our country can be proud, and yet it is only a beginning of possibilities. Inasmuch as the total foreign commerce of Latin America for 1907 was over $2,000,000,000, it can be seen that the United States is far from having her share. The great point is that if the United States, under present conditions and with the present lack of interest, can conduct a trade with Latin America of nearly $600,000,000 per annum, it is sure to do a business of $1,000,000,000 in the near future, after our manufacturing and agricultural interests fully realize the value of the opportunity and put forth their best energies to control it. Having taken up these measurements of commerce and trade, it is logical that we should consider some descriptive facts which shall prove to everybody the greatness and importance of the Latin- American countries. There is not space in a brief article like this to describe carefully what has been done by Mexico, Central America, Cuba, Haiti, and the Dominican Republic, which border on the Gulf of Mexico and the Caribbean Sea, and therefore particular attention will be given only to South America proper. In passing, however, we should bear in mind that over $800,000,000 of American capital has been invested in Mexico, and that last year that country conducted a trade with the United States valued at over $125,000,000, of which over $67,000,000 represented imports from the United States. Central America, comprising Guatemala, Salvador, Honduras, Nicaragua, and Costa Rica, is entering upon a new era of prosperity and progress as a result of the treaties and conventions signed at the Central American Peace Conference recently held in Washington. If these international agreements are approved by all these countries, there is no reason why they should not have a growth and development like that of Mexico, because they possess a remarkable vari- ety of resources and a favorable climate in most sections. In 1906 Central America conducted a foreign trade valued at almost $56,000,000, of which the imports from the United States amounted to nearly $12,000,000. The republics and islands of the West Indies are forging ahead, and last year boasted of a foreign trade amounting to $240,000,000, of which $153,000,000 were imports by these islands from the United States. An undenominational educational institution founded in 1889 by John T. Mackenzie, of NewYork, who gave $42,000 t9\vard the erection of the building. It has graded and normal departments and a self-supporting manual training school. Coming, then, to South America proper and noting some salient facts, we are impressed first with Colombia, the nearest to the United States of the South American republics, having an area as large as Germany and France put together, and entering upon an era of rapid progress as the result of the enlightened administration of General Rafael Eeyes. Having traveled extensively over the interior of Colombia, I can vouch for its richness. As soon as it is opened up by railroads and by improved navigation of its rivers, it should have a development not unlike that of Mexico. Venezuela greatly resembles Colombia, with an unusual mingling of rich plateaus and river valleys which offer an inviting field of legitimate exploitation. The mighty valley of the Orinoco alone is a section in which millions and millions of capital may be safely invested. The British, Dutch, and French Guianas have only been barely touched by the hand of capital, and yet they will soon experience a Drogress surpassing any past development. Brazil is indeed an interesting subject to discuss. It is so large, so resourceful, and so vast in potentialities that it is difficult to confine oneself to conservative language. When we remember that the entire connected area of the United States could be placed inside the limits of Brazil and that there would still be room for the German Empire ; that out of the Amazon River flows every day three times as much water as from the Mississippi; that Rio de Janeiro, its capital, is already a city of 900,000 inhabitants and growing with rapidity ; that the government and people of Brazil gave our battle-ship fleet a more magnificent welcome than was ever given to a visiting fleet from a foreign nation in the history of the world, then we shall have before us some facts that show how worthy of our special attention is this great Republic of South America. All over Brazil there is evidence of the new era of material progress. Railroads are being built into the interior, rivers and harbors are being improved, the cities are being modernized, the school systems are being elaborated, and the native richness of the soil and forests is being exploited, with the result that a large amount of European and American capital is being invested there with absolute surety of good returns. In no country of South America has the manufacturer and exporter a better chance to build up his trade than in Brazil. To-day the balance of commerce exchanged is greatly against us. Brazil buys from the United States only about one-fifth in value of what she sells there. This country is Brazil's chief market for coffee, but our merchants have made so little effort to supply what Brazil demands from foreign countries that Europe practically controls the import situation. Uruguay, just below Brazil, and Paraguay, between Brazil and Argentina, are small in area, but rich in agricultural possibilities. The city of Montevideo, the capital of Uruguay, has a population of 300,000 and is an important port at the mouth of the Rio Plata. The peoples of both countries are enterprising and progressive, and believe that their nations will see remarkable progress during the next decade. Montevideo is spending $10,000.000 in the im- provement of its harbor facilities, while Asuncion, the capital of Paraguay, is looking forward to the improvement of the River Parana and to the extension of the railroad system, so that it will be in communication on the one hand with Argentina and Uruguay and on the other with Brazil. In this connection it must be remembered that southern Brazil, Uruguay, Paraguay, all of Argentina and Chile are practically in the south temperate zone, and possess climatic conditions not unlike those of the United States far north of the equator. Such a location means much for their future development as the homes of ambitious peoples. ARGENTINA A WONDERLAND OF MATERIAL PROGRESS. Argentina is a country of peculiar interest. It has gone ahead with such rapidity during the last ten years that it is difficult to predict what another decade will show. It has such a large area suitable for the growth of products which are needed in Europe that it is always sure to have an enormous foreign trade. With a present population of nearly 6,000,000 people it conducted in 1907 a foreign commerce valued at nearly $600,000,000, a total greater than that of Japan or of China. This gives an average of nearly $100 a head, which is larger than that of any other important country in the wTorld. Argentina is gridironed with a system of railroads which enables one to cross the continent from Buenos Aires to Santiago in less than forty-eight hours, including a short trip by coach over the top of the Andes, and to go in a Pullman train from the borders of Bolivia on the north into the heart of Patagonia on the south. Buenos Aires, its capital, is one of the wonderful cities of the world. It has a population now of nearly 1,200,000, and is growing more rapidly than any city in the United States with the exception of New York and Chicago. It has a finer system of docks and wharves, a more costly and beautiful opera house, a larger club, and a more extensive newspaper plant than any city of our own progressive land. It has plans to build an intricate system of underground railways, and it is made beautiful by numerous boulevards, parks, and squares. The commerce of all Argentina centers in Buenos Aires, and it is not an uncommon thing to see scores and scores of merchant vessels, flying the flag of every important country except the United States, loading and unloading along its water front. The people are decidedly progressive and represent a new race, inasmuch as they are a combination of Spanish and Italian, with a sprinkling of English and German blood, and they are developing a class of men and women who insure the future strength and quality of the country. CHILE AND THE WEST COAST OF SOUTH AMERICA. The size and importance of Chile can be best appreciated by remembering, first, that it runs up and down the west coast of South America in the Temperate Zone just as our own west coast borders on the Pacific Ocean, and, second, that if the southern end of Chile were placed at San Diego, the southern end of California, the northern line of Chile would be located in the middle of Alaska. In other words, it extends north 2,600 miles from the Straits of Magellan to the Peruvian border, while its average width is that of California, whence Peruvian gold was shipped to Europe, and is now one of the leading ports of Colombia. with a corresponding variety of climate and products. Its capital city, Santiago, has a population of 400,000, and is classed as one of the most attractive cities of the southern continent. At its principal port, Valparaiso, the Chilean Government is preparing to spend $10,000,000 for harbor and dockage facilities, thus making it the most complete port on the Pacific Ocean. Although Chile is well provided with railroads, the Government is now at work on a scheme for a longitudinal road to run the entire length of the country, and to connect the capital with every section. The enormous wealth of the nitrate fields of Chile brings to the country a vast revenue which makes it almost independent of other sources for the maintenance of the Government. Chile is anxious for the completion of the Panama Canal, so that it can get into closer touch with the United States. When that waterway is completed, it should be possible to go from New York to Valparaiso in less than fifteen days, while now it takes on an average of thirty days. The foreign commerce of Chile last year amounted to $180,000,000. BOLIVIA, PERU, AND ECUADOR. Although Bolivia has no seacoast, it covers an immense territory, in wrhich could be placed the State of Texas twice over and still leave room for Arkansas and Kansas. A large portion of it is located at a high altitude, so that it has favorable climatic conditions. It possesses a remarkable variety of mineral and agricultural riches, and is entering now upon a period of real progress. An American syndicate is building a system of railroads upon which will be expended fully $100,000,000. Its interesting capital, La Paz, can be reached by a combination journey of rail and water up frrn the Pacific Ocean and across Lake Titicaca, the most elevated navigable body of water in the world. The value of the foreign trade of Bolivia is approximately $35,000,000, but it is growing with rapidity and bids fair to double itself in the near future. North of Bolivia extends Peru over an area in which could be placed all of the Atlantic Coast States from Maine to Georgia. It has a mingling of low country along the Pacific, and again in the upper valleys of the Amazon, so that, with the great plateaus and mountainous districts of the Andes, Peru possesses a wide variety of climate, products, and resources. Many millions of American capital have already been invested there in the development of its mines. Lima, the capital city of Peru, is one of the oldest and most aristocratic capitals of Latin America. Here was established a university one hundred years before Harvard was founded. Here was the seat of one of the Spanish vice-royalties in the days of the old regime. To-day it is a prosperous, busy, and well-built metropolis. The port of Lima is Callao, only a few miles away, where the American fleet under Admiral Evans made its fourth stop in its journey around South America. It has an excellent harbor, and through it passes the greater part of the foreign trade of Peru, amounting to $49,150,000. Ecuador, in which the State of Illinois could be placed many times, is rejoicing now in the prospect of the advantages of the railroad which connects its principal port, Guayaquil, on the coast, with the famous old capital of the Republic, Quito, a city of about 80,000 people, located at an elevation of 10,000 feet above sea level, upon the plateaus of the Andes. When the branches of this road are completed the interior of Ecuador will experience a development that will add much to the wealth of the country. In 1909 Ecuador will hold an exposition to celebrate the one hundredth anniversary of the declaration of independence from Spain, and it is expected that there will be a great display of the natural resources and products of the country, which will be sure to attract universal attention and prove the value of this region as a field for the investment of foreign capital. The United States has been invited to participate, and President Roosevelt has recommended to Congress that an appropriation be voted for a building and exhibit. A VISIT TO SOUTH AMERICA RECOMMENDED. While what I have written about these countries may awaken interest among those who have paid no attention to South America, I am prompted to advise strongly that every person who has the time and money should make a visit to the principal countries and cities of South America and see with his own eyes the possibilities of that part of the world. The average American business man when he wants a vacation goes to Europe ; some few go to the Far East, but practically no one proceeds to South America. If the conditions could be changed, and travel to the southern continent popularized, the beneficial effects upon the development of our commerce would soon be evident. This prepares the way for pointing out the vital importance of improving our shipping facilities with South America. In contrast to the possibility of reaching the chief cities of Brazil, Argentina, Chile, and other countries by fast and commodious steamers running from Europe in considerable numbers, is the fact that there is not one first-class mail, express, and passenger steamer flying the American flag and running between any one of the ports of the United States and those of South America below the equator. It is most depressing for a citizen of the United States to make the grand tour of these southern cities and see nowhere the Stars and Stripes unless it be floating from an occasional man-of-war or pleasure yacht. Perhaps he may run across a sailing vessel with the United States flag, but even these are few in number compared to what they were in the olden days. consuming eighteen days, and to Montevideo and Buenos Aires, on the through steamers, four to seven days longer. For Asuncion, the capital of Paraguay, there are numerous first-class steamers up the river Parana from Buenos Aires. A more popular and fashionable route is to go first to Europe, where, at Southampton and Havre, English, French, and German steamers of the most modern and luxurious type provide accommodation for passengers to Rio in sixteen days and to Montevideo and Buenos Aires in four to six days more. twelve days indirect service. The Caribbean ports of Colombia, Cartagena, and Baranquilla are visited by steamers from New York, which stop also at Colon on the Isthmus of Panama and at Kingston in Jamaica. All Pacific ports are reached from Panama after crossing the Isthmus from Colon, or by taking a steamer from San Francisco which touches all intermediate points between San Francisco and the Pacific ports of Colombia, Ecuador, Peru, and Chile. Steamers can be taken in New York to reach Costa Rica, Nicaragua, and, since the opening of the railway from Puerto Barrios, even Guatemala. For Salvador, Honduras, and the west coast of Guatemala and Nicaragua, the steamers from San Francisco or Panama are the more available. The commerce of the United States with South America proper has already been shown to be only $233,000,000 out of the total foreign trade of these countries amounting to $1,500,000,000. That this condition is coincident writh the lack of first-class steamship facilities is at least a justifiable conclusion, if it is not entire 'proof that one is responsible for the other. Despite the fact that there are a large number of freight vessels, all of them flying foreign flags, running between the chief ports of the United States and those of South America, it is just as necessary for us to have fast mail, express, and passenger steamers on the high seas to conduct commerce, to carry letters, and to take care of passenger traffic and express freight requiring early delivery, as it is to have the corresponding kind of railroad trains upon land. Can anyone imagine Chicago holding its present position if it were reached only by freight trains? The fast mail, express, and passenger railroad service is an absolute, if not the principal, essential to the development of the exchange of trade. It is folly, therefore, to expect that the United States can ever hold an important position in the commerce of South America unless the facilities for going back and forth and for mail communication are improved. There could be no better evidence of the unfortunate state of affairs than the fact that more business men from the progressive Republic of Argentina left Buenos Aires in one week, aboard the fast and elegant European steamers, either to visit Europe on business or to enjoy travel, than proceeded to the United States in a whole year on the slow-going vessels that connect Buenos Aires with New York. The records of Rio de Janeiro, the great capital of Brazil, show that the European boats in one week carried away more Brazilians to Europe than all the vessels running to the United States in a whole year. The solution of this problem is not in a so-called " subsidy," which is an unfortunate term and often misleading. The whole question boils itself down into the necessity of paying a good wage for work GOVERNMENT BUILDING IN SUCRE, ONE OF THE PRINCIPAL CITIES OF BOLIVIA. well done. That is, the United States Government must be ready to pay steamship companies flying the American flag such a reasonable sum for carrying the mails on vessels of, say, IT knots speed and first-class passenger accommodations, that they can deliver mails and passengers in competition with the vessels of Europe, and so provide the same kind of facilities on sea that we get from the mail trains on land throughout the United States, and to which the United States Government pays a regular sum for the quality of service rendered. Bureau of the American Kepublics. This institution was founded eighteen years ago at the first Pan-American Conference for the purpose of disseminating information throughout the different American Republics concerning mutual progress and development. As a result of the third Pan-American Conference held at Rio de Janeiro and through the efforts of Secretary Root, who has done more than any other man in the history of American diplomacy to advance the prestige and influence of the United States in Latin America, it has been reorganized and enlarged so that it may become HIDE AND WOOL SECTION OF CENTRAL PRODUCE MARKET, BUENOS AIRES. The Central Produce Market of Buenos Aires is the largest wool and hide market in the world. The building is an iron structure four stories high, covering an area of 182,000 square feet, and was erected at a cost of about $4,100,000. There is a complete installation of cranes, elevators, and apparatus for loading and unloading the principal export products of Argentine Republic. Immense quantities of wool, hides, and cereals are annually shipped from this market to the large commercial ports of the world. a world-recognized and practical agency for the development of Pan-American commerce and comity. It is intended to be not only a bureau of information, supplying all varieties of data regarding different American countries to manufacturers, educators, travelers, students, etc., but the means through which all the resolutions of the different Pan-American conferences shall be put into force. Everything possible is done by the Bureau to bring about better relations and more intimate acquaintance and intercourse among all the nations of the Western Hemisphere. It publishes a monthly bulletin which is a careful record of the commercial and business conditions of all the republics, and distributes a large number of publications descriptive of the American republics, their conditions, resources, and potentialities. Connected with it is the Columbus Memorial Library, which is the largest single collection in the United States of books relating to the history, progress, and present status of all the countries under discussion. Through the beneficence of Mr. Andrew Carnegie and the contributions of the different governments, the International Bureau is shortly to be housed in a magnificent new building which will cost approximately $750.000, and provide in Washington a temple of friendship and commerce which will be, in a sense, a meeting place for all the American republics. The Bureau is supported by the joint contributions of the 21 American republics, and its affairs are controlled by a governing board composed of the diplomatic representatives in Washington of 20 republics, with the Secretary of State of the United States as chairman ex-officio. Its chief executive officer is the director, who is chosen by this governing board. He, in turn, is assisted by the secretary of the Bureau and other officials and experts. In the event that anyone desires information, he may address the Director, Pan-American Bureau (as it is commonly described), 2 Jackson Place, Washington, D, C. It will be a special pleasure to consider carefully any inquiries regarding Latin America which may come from the large and representative constituency of The World To-Day. CALLE DE ESTADO, SANTIAGO, CHILE. Calle de Estado is one of the busiest thoroughfares in Santiago, running from the "Alameda de las Delicias" to the principal square, the "Plaza de Armas." It is lined with numerous retail stores, in which can be found all the luxuries of American or European cities. HOW THE BUSINESS MAN CAN USE THE SERVICE GIVEN FREE BY THE INTERNATIONAL BUREAU OF THE AMERICAN REPUBLICS, TO BECOME FAMILIAR WITH CONDITIONS IN LATIN AMERICA, TO LEARN THEIR SPECIFIC DEMANDS, AND TO AID IN SECURING PROFITABLE BUSINESS. Every business man, every professional man, every man interested in our foreign relations, should become acquainted with the International Bureau of the American Republics. Its great practical value to the business man, its possibilities for good in the development of both commerce and comity among the American nations, the vast field it represents — these facts bring a realization of its importance. it is essential to know its history. Although it has led a dignified and honorable existence for eighteen years, and has had excellent and able men at its head, there has never been until now any popular interest in our sister American nations. It required the statesmanship of an Elihu Root and an unprecedented journey on his part all around the South American continent to make the people of the United States realize the vast importance of our relations with the nations to the south of us. The International Bureau wras organized as a result of the first Pan-American Conference held at Washington in 1889-90. The delegates from Latin America found such ignorance here of the peoples, institutions, and resources of their countries, and, on the other hand, such ignorance on their part of the real characteristics of the United States, that the conference authorized the opening of what might be called an International Bureau of Information. Subsequent conferences enlarged its functions until now it bids fair to become one of the most important international institutions of the world. The early directors exerted their best efforts for the welfare of the Bureau, but they labored under the handicap of lack of general interest. Now a new era is dawning and the present director, no more capable than his predecessors, finds a far more sympathetic constituency to aid his programme of reorganization and upbuilding. quarters in the capital of one American nation of 21 American Republics. Its director is the only international officer of America chosen by the vote of all the American governments. MERCADO DE FILAR, BUENOS AIRES, ARGENTINE REPUBLIC. One of the numerous markets of the city of Buenos Aires. The stalls and stands are required to be kept scrupulously clean, and strict hygienic regulations must be observed in the sale of fruits, vegetables, meats, and other similar products. The Bureau is not in any sense subordinate to a department of the United States, as are all the other bureaus of Washington. It is strictly independent, and its chief officer is responsible to the 21 representatives of the American governments who constitute its governing board and guide its policies. This board lias as its chairman the Secretary of State of the United States, inasmuch as the Bureau is located in Washington and its relations with the United States Government are through the Department of State. The contributions of all the American republics, based on population, give it financial support. Although the United States consequently pays more1 than the other 20 combined, the minister of the smallest nation in population has a vote in its governing board equal to that of the Secretary of State of the United States. It is this feature of equal, mutual interest and authority that keeps up the pride of all Latin America in its work and advancement. The diplomat, business man, or traveler from Central America or distant Argentina and Chile, Avho walks into the Bureau or writes to its staff for information, is just as much at home as the corresponding man from the United States. Out of the total 12,000,000 square miles occupied by. the American countries, those of Latin America include nearly 9,000,000 against 3,000,000 of the United States proper. Brazil alone exceeds the connected area of the United States by nearly 200,000 square miles; we could put all of the United States, without Alaska, within Brazil and still have room for the major portion of the German Empire. Of the 155,000,000 people living in the American republics, 70,000,000 reside in the Latin-American countries — certainly enough to be worthy of our close study and of our sincere friendship. That number of millions can also buy a considerable quantity of products of other countries as further figures will demonstrate. The total foreign commerce, exports and imports, of the 21 Amercan republics, including the United States, last year exceeded $5,000,000,000. Of this huge total, Latin America— too often despised by our business men — bought and sold products valued at the vast sum of over $2,000,000,000, or more than one-third. That we are getting a share of this, which proves its value, is admitted when it is shown that our portion of these $2,000,000,000 was $600,000,000 for the past year. This immediately suggests the question to the manufacturer and exporting or importing reader of this article : "Am I getting my part of this ? " . If the answer is " No," then he should write to the International Bureau of the American Republics and find out why not— and how he may. THE PERSONNEL AND ORGANIZATION OF THE BUREAU. The source of this information will be the working staff of the Bureau, which is composed of about 25 persons. These are divided into administrative, editorial, translating, statistical, compiling, and service sections. All incoming correspondence is supposed to be addressed " The Director, Pan-American Bureau, 2 Jackson Place, Washington, D. C.," but, whatever way it may be directed, it is given immediate attention and sent to whatever section is to prepare the answer. All outgoing letters are signed by either the director or by the secretary of the Bureau, the chief clerk, or the librarian, as the case requires. Careful files are kept of correspondence, and it is the rule of the Bureau to answer all inquiries with the least possible delay. The officer, after the director, having general supervision of the work of the Bureau is its secretary, Dr. Francisco J. Yanes, an accom- can commerce. To supply every kind of information within its scope, the International Bureau depends first on its library, known as the Columbus Memorial Library, of over 15,000 volumes covering every American nation and containing the best individual collection of Americana in the United States; second, on the official reports of all American governments, which are sent to it in accordance with the resolution of the Pan-American Conference ; third, on the official gazette and private newspapers, trade journals, and similar publications of the different capitals ; fourth, on reports of American consular officers in the form of duplicate copies of the originals sent to the Department of State ; fifth, on handbooks and pamphlets carefully prepared from time to time, describing the resources, progress, conditions, and development of the different countries; and sixth, on maps and geographic data, as prepared by official and private agencies and persons. 160 feet in length. All this material is thoroughly classified and can be consulted without delay. The library is open to responsible people from 9.30 a. m. until 4 p. m. every day, and books are loaned for brief periods to those who are properly accredited. If a business man, student, or traveler addresses any inquiry to the Bureau, the qualified members of its staff compile from the data just described the necessary reply; if he calls in person, he is immediately placed in touch with the mem88812—09 7 THE PRACTICAL RESULTS ATTAINED BY THE BUREAU. One or two illustrations will serve to show the business man how the machinery of the bureau works in his interest. A manufacturer of automobiles writes or calls and says that he knows nothing concerning the Latin-American market, but that he is contemplating Santos. The director or secretary acknowledges his letter at once, giving some comprehensive ideas and forwarding pamphlets describing general conditions in Latin America so far that the manufacturer may gain preliminary information on the field he is studying. Then one of the statistical or trade experts of the Bureau compiles a memorandum showing present imports of automobiles to Latin America, country of origin, conditions of demand and competition, character of roads and streets, freight charges, shipping facilities, tariff or customs rates, methods of payment, climatic effects on material, and any other practical data that would be useful and helpful. This handsome building is the central station of the 32 police precincts into which the city of Buenos Aires is divided. The police force, consisting of about 4,000 officers and men, is supplemented by a mounted squadron of 100 gendarmes. The police department is well organized, and is noted for the required for clim%ite,:"aiid° tilne^ heedefd ^ior different journeys. The university professor, student, lecturer, or writer seeks the best material for acquiring information on Latin America. He is given a practical list of books and magazines to read and maps to secure, with names of publishers and authors. And so I might go on and on giving examples of the constant and increasing evidences of the good work the Bureau is doing, not only along material, commercial, and economic lines, but in educational, social, and intellectual directions. Perhaps it suffices to add here that the correspondence of the Bureau has quadrupled during the last eight months and the demands for its printed matter has grown in proportion. It now averages nearly 3,000 letters of legitimate inquiry from all parts of the world, received and answered each month, together with 20,000 bulletins, handbooks, pamphlets, and circulars distributed for the same period. MAGAZINES AND VARIOUS PUBLICATIONS ISSUED AS HELPS TO BUSINESS. The most important connection between the Bureau and the great commercial interests of Pan- America is its " Monthly Bulletin." This is issued in magazine form at the end of each month and contains the latest official data from all the American republics covering exports and imports, trade conditions, tariff changes, public improvements and enterprises, industrial opportunities, new laws affecting commerce, immigration, and mining concessions, and other kindred information. It may be obtained by paying the annual subscription of $2 in the American republics or $2.50 in non-American countries. Aside from the Monthly Bulletin the bureau has for sale at cost many useful handbooks and pamphlets, together with others which are sent free upon application. There is a printed list of all publications that will be immediately forwarded to those expressing a desire for it. In order that this article may be complete, and the scope and importance of this institution thoroughly understood, I desire to quote from the resolutions passed at the last Pan-American Conference held in Rio de Janeiro, Brazil, during 1906, and made memorable by the presence of Secretary Root. They read : ferences. G. To act as a permanent committee of the International American Conferences, recommending topics to be included in the programme of the next conference ; these plans must be communicated to the various governments forming the union at least six months before the meeting of the next conference. 7. To submit within the same period a report to the various governments on the work of the bureau during the term covered since the meeting of the last conference and also special reports on any matter which may have been referred to it for report. recently prepared I say : Further resolutions, which placed new responsibilities on the bureau, provided that steps should be taken for housing the institution " in such a way as shall properly permit it to fulfill the important functions assigned to it by this conference;" that a committee should be appointed in each republic to assist the bureau in carrying out its work ; that there should be established, as subordinate to it, a special section for commercial statistics ; that the bureau should elaborate the project for providing better steamship facilities between the principal ports of the American Republics for the purpose of facilitating trade, travel, commerce, and reneral communication ; that it should investigate the question of the Intercontinental Railway and confer with the different governments with a view to determining as soon as possible what concessions of land, subventions, interest guaranties, exemptions of duty on material for construction and rolling stock, and any other concessions they may deem it advisable to grant in connection therewith ; that it should make a study of the monetary systems of the American Governments for the purpose of submitting to the next conference a report on the systems in force in each of the Governments, the history, fluctuations, and type of exchange which have taken place within the last twenty years, including the preparation of tables showing the influence of said fluctuations on commerce and industrial development; that it should study the laws that regulate public concessions in the various republics of America, with a view to obtaining information that might be useful to it; and that, iinally, it should prepare a programme for the Fourth International Conference, which is to be held within the next five years. business man. I. Over 1,000 manufacturers, exporters, and importers of the United States have decided, during the last two years, through the recommendations of the International Bureau of American Republics, to enter the Latin-American field. II. Correspondingly a large element of Latin-American business men have commenced transactions with the United States who before knew nothing of the opportunities here. IV. The study" ti£ me^Spa-hisli^l&iJgiiage and of Latin-American history, development, and present conditions has been inaugurated in various North-American institutions of learning, which before gave little attention to those subjects, while the number of Latin-American young men coming to attend schools in the United States has been notably augmented. V. Chambers of commerce, boards of trade, social and literary clubs and circles, in all parts of the United States, have taken steps, under the initiative and with the cooperation of the Bureau, to familiarize their members with Latin America as they have in the past with Europe and Asia. VI. The spirit of international friendship and mutual confidence among all the American republics has been fostered through the closer touch one with another, which the Bureau affords as an institution supported by all and in whose welfare each has an equal interest and responsibility. It must, moreover, not only oversee the acceptance of the resolutions of the last Pan- American Conference, but drawT up the programme for the one which will assemble in 1910. VII. As director, or chief administrative officer of the Bureau, I can honestly say that, while it has many shortcomings and the task of building it up has only just begun, it is always ready to give Avhat information and assistance it legitimately can for the promotion of Pan- American trade, accord, and intercourse, and it hopes the readers of Svstem will avail themselves of its facilities.	28,409	common-pile/pre_1929_books_filtered	latinamericaland00barrrich	public_library	public_library_1929_dolma-0025.json.gz:2341	https://archive.org/download/latinamericaland00barrrich/latinamericaland00barrrich_djvu.txt
Z0W-lhqqOgsWU8WT	Disturbing Sun	Produced by Greg Weeks, Bruce Albrecht, Mary Meehan and the Online Distributed Proofreading Team at http://www.pgdp.net DISTURBING SUN By PHILIP LATHAM Illustrated by Freas [Transcriber's Note: This etext was produced from Astounding Science Fiction May 1959. Extensive research did not uncover any evidence that _This, be it understood, is fiction--nothing but fiction--and not, under any circumstances, to be considered as having any truth whatever to it. It's obviously utterly impossible ... isn't it?_ _An interview with Dr. I. M. Niemand, Director of the Psychophysical Institute of Solar and Terrestrial Relations, Camarillo, California._ _In the closing days of December, 1957, at the meeting of the American Association for the Advancement of Science in New York, Dr. Niemand delivered a paper entitled simply, "On the Nature of the Solar S-Regions." Owing to its unassuming title the startling implications contained in the paper were completely overlooked by the press. These implications are discussed here in an exclusive interview with Dr. Niemand by Philip Latham._ LATHAM. Dr. Niemand, what would you say is your main job? NIEMAND. I suppose you might say my main job today is to find out all I can between activity on the Sun and various forms of activity on the Earth. LATHAM. What do you mean by activity on the Sun? NIEMAND. Well, a sunspot is a form of solar activity. LATHAM. Just what is a sunspot? NIEMAND. I'm afraid I can't say just what a sunspot is. I can only describe it. A sunspot is a region on the Sun that is cooler than its surroundings. That's why it looks dark. It isn't so hot. Therefore not so bright. LATHAM. Isn't it true that the number of spots on the Sun rises and falls in a cycle of eleven years? NIEMAND. The number of spots on the Sun rises and falls in a cycle of _about_ eleven years. That word _about_ makes quite a difference. LATHAM. In what way? NIEMAND. It means you can only approximately predict the future course of sunspot activity. Sunspots are mighty treacherous things. LATHAM. Haven't there been a great many correlations announced between sunspots and various effects on the Earth? NIEMAND. Scores of them. LATHAM. What is your opinion of these correlations? NIEMAND. Pure bosh in most cases. LATHAM. But some are valid? NIEMAND. A few. There is unquestionably a correlation between sunspots and disturbances of the Earth's magnetic field ... radio fade-outs ... auroras ... things like that. LATHAM. Now, Dr. Niemand, I understand that you have been investigating solar and terrestrial relationships along rather unorthodox lines. NIEMAND. Yes, I suppose some people would say so. LATHAM. You have broken new ground? NIEMAND. That's true. LATHAM. In what way have your investigations differed from those of others? NIEMAND. I think our biggest advance was the discovery that sunspots themselves are not the direct cause of the disturbances we have been studying on the Earth. It's something like the eruptions in rubeola. Attention is concentrated on the bright red papules because they're such a conspicuous symptom of the disease. Whereas the real cause is an invisible filterable virus. In the solar case it turned out to be these S-Regions. LATHAM. Why S-Regions? NIEMAND. We had to call them something. Named after the Sun, I suppose. LATHAM. You say an S-Region is invisible? NIEMAND. It is quite invisible to the eye but readily detected by suitable instrumental methods. It is extremely doubtful, however, if the radiation we detect is the actual cause of the disturbing effects observed. LATHAM. Just what are these effects? NIEMAND. Well, they're common enough, goodness knows. As old as the world, in fact. Yet strangely enough it's hard to describe them in exact terms. LATHAM. Can you give us a general idea? NIEMAND. I'll try. Let's see ... remember that speech from "Julius Caesar" where Cassius is bewailing the evil times that beset ancient Rome? I believe it went like this: "The fault, dear Brutus, is not in our stars but in ourselves that we are underlings." LATHAM. I'm afraid I don't see-- NIEMAND. Well, Shakespeare would have been nearer the truth if he had put it the other way around. "The fault, dear Brutus, is not in ourselves but in our stars" or better "in the Sun." LATHAM. In the Sun? NIEMAND. That's right, in the Sun. I suppose the oldest problem in the world is the origin of human evil. Philosophers have wrestled with it ever since the days of Job. And like Job they have usually given up in despair, convinced that the origin of evil is too deep for the human mind to solve. Generally they have concluded that man is inherently wicked and sinful and that is the end of it. Now for the first time science has thrown new light on this subject. LATHAM. How is that? NIEMAND. Consider the record of history. There are occasional periods when conditions are fairly calm and peaceful. Art and industry flourished. Man at last seemed to be making progress toward some higher goal. Then suddenly--_for no detectable reason_--conditions are reversed. Wars rage. People go mad. The world is plunged into an orgy of bloodshed and misery. LATHAM. But weren't there reasons? NIEMAND. What reasons? LATHAM. Well, disputes over boundaries ... economic rivalry ... border incidents.... NIEMAND. Nonsense. Men always make some flimsy excuse for going to war. The truth of the matter is that men go to war because they want to go to war. They can't help themselves. They are impelled by forces over which they have no control. By forces outside of themselves. LATHAM. Those are broad, sweeping statements. Can't you be more specific? NIEMAND. Perhaps I'd better go back to the beginning. Let me see.... It all started back in March, 1955, when I started getting patients suffering from a complex of symptoms, such as profound mental depression, anxiety, insomnia, alternating with fits of violent rage and resentment against life and the world in general. These people were deeply disturbed. No doubt about that. Yet they were not psychotic and hardly more than mildly neurotic. Now every doctor gets a good many patients of this type. Such a syndrome is characteristic of menopausal women and some men during the climacteric, but these people failed to fit into this picture. They were married and single persons of both sexes and of all ages. They came from all walks of life. The onset of their attack was invariably sudden and with scarcely any warning. They would be going about their work feeling perfectly all right. Then in a minute the whole world was like some scene from a nightmare. A week or ten days later the attack would cease as mysteriously as it had come and they would be their old self again. LATHAM. Aren't such attacks characteristic of the stress and strain of modern life? NIEMAND. I'm afraid that old stress-and-strain theory has been badly overworked. Been hearing about it ever since I was a pre-med student at UCLA. Even as a boy I can remember my grandfather deploring the stress and strain of modern life when he was a country doctor practicing in Indiana. In my opinion one of the most valuable contributions anthropologists have made in recent years is the discovery that primitive man is afflicted with essentially the same neurotic conditions as those of us who live a so-called civilized life. They have found savages displaying every symptom of a nervous breakdown among the mountain tribes of the Elgonyi and the Aruntas of Australia. No, Mr. Latham, it's time the stress-and-strain theory was relegated to the junk pile along with demoniac possession and blood letting. LATHAM. You must have done something for your patients-- NIEMAND. A doctor must always do something for the patients who come to his office seeking help. First I gave them a thorough physical examination. I turned up some minor ailments--a slight heart murmur or a trace of albumin in the urine--but nothing of any significance. On the whole they were a remarkably healthy bunch of individuals, much more so than an average sample of the population. Then I made a searching inquiry into their personal life. Here again I drew a blank. They had no particular financial worries. Their sex life was generally satisfactory. There was no history of mental illness in the family. In fact, the only thing that seemed to be the matter with them was that there were times when they felt like hell. LATHAM. I suppose you tried tranquilizers? NIEMAND. Oh, yes. In a few cases in which I tried tranquilizing pills of the meprobamate type there was some slight improvement. I want to emphasize, however, that I do not believe in prescribing shotgun remedies for a patient. To my way of thinking it is a lazy slipshod way of carrying on the practice of medicine. The only thing for which I do give myself credit was that I asked my patients to keep a detailed record of their symptoms taking special care to note the time of exacerbation--increase in the severity of the symptoms--as accurately as possible. LATHAM. And this gave you a clue? NIEMAND. It was the beginning. In most instances patients reported the attack struck with almost the impact of a physical blow. The prodromal symptoms were usually slight ... a sudden feeling of uneasiness and guilt ... hot and cold flashes ... dizziness ... double vision. Then this ghastly sense of depression coupled with a blind insensate rage at life. One man said he felt as if the world were closing in on him. Another that he felt the people around him were plotting his destruction. One housewife made her husband lock her in her room for fear she would injure the children. I pored over these case histories for a long time getting absolutely nowhere. Then finally a pattern began to emerge. LATHAM. What sort of pattern? NIEMAND. The first thing that struck me was that the attacks all occurred during the daytime, between the hours of about seven in the morning and five in the evening. Then there were these coincidences-- LATHAM. Coincidences? NIEMAND. Total strangers miles apart were stricken at almost the same moment. At first I thought nothing of it but as my records accumulated I became convinced it could not be attributed to chance. A mathematical analysis showed the number of coincidences followed a Poisson distribution very closely. I couldn't possibly see what daylight had to do with it. There is some evidence that mental patients are most disturbed around the time of full moon, but a search of medical literature failed to reveal any connection with the Sun. LATHAM. What did you do? NIEMAND. Naturally I said nothing of this to my patients. I did, however, take pains to impress upon them the necessity of keeping an exact record of the onset of an attack. The better records they kept the more conclusive was the evidence. Men and women were experiencing nearly simultaneous attacks of rage and depression all over southern California, which was as far as my practice extended. One day it occurred to me: if people a few miles apart could be stricken simultaneously, why not people hundreds or thousands of miles apart? It was this idea that prompted me to get in touch with an old colleague of mine I had known at UC medical school, Dr. Max Hillyard, who was in practice in Utica, New York. LATHAM. With what result? NIEMAND. I was afraid the result would be that my old roommate would think I had gone completely crazy. Imagine my surprise and gratification on receiving an answer by return mail to the effect that he also had been getting an increasing number of patients suffering with the same identical symptoms as my own. Furthermore, upon exchanging records we _did_ find that in many cases patients three thousand miles apart had been stricken simultaneously-- LATHAM. Just a minute. I would like to know how you define "simultaneous." NIEMAND. We say an attack is simultaneous when one occurred on the east coast, for example, not earlier or later than five minutes of an attack on the west coast. That is about as close as you can hope to time a subjective effect of this nature. And now another fact emerged which gave us another clue. LATHAM. Which was? NIEMAND. In every case of a simultaneous attack the Sun was shining at both New York and California. LATHAM. You mean if it was cloudy-- NIEMAND. No, no. The weather had nothing to do with it. I mean the Sun had to be above the horizon at both places. A person might undergo an attack soon after sunrise in New York but there would be no corresponding record of an attack in California where it was still dark. Conversely, a person might be stricken late in the afternoon in California without a corresponding attack in New York where the Sun had set. Dr. Hillyard and I had been searching desperately for a clue. We had both noticed that the attacks occurred only during the daylight hours but this had not seemed especially significant. Here we had evidence pointing directly to the source of trouble. It must have some connection with the Sun. LATHAM. That must have had you badly puzzled at first. NIEMAND. It certainly did. It looked as if we were headed back to the Middle Ages when astrology and medicine went hand in hand. But since it was our only lead we had no other choice but to follow it regardless of the consequences. Here luck played somewhat of a part, for Hillyard happened to have a contact that proved invaluable to us. Several years before Hillyard had gotten to know a young astrophysicist, Henry Middletown, who had come to him suffering from a severe case of myositis in the arms and shoulders. Hillyard had been able to effect a complete cure for which the boy was very grateful, and they had kept up a desultory correspondence. Middletown was now specializing in radio astronomy at the government's new solar observatory on Turtle Back Mountain in Arizona. If it had not been for Middletown's help I'm afraid our investigation would never have gotten past the clinical stage. LATHAM. In what way was Middletown of assistance? NIEMAND. It was the old case of workers in one field of science being completely ignorant of what was going on in another field. Someday we will have to establish a clearing house in science instead of keeping it in tight little compartments as we do at present. Well, Hillyard and I packed up for Arizona with considerable misgivings. We were afraid Middletown wouldn't take our findings seriously but somewhat to our surprise he heard our story with the closest attention. I guess astronomers have gotten so used to hearing from flying saucer enthusiasts and science-fiction addicts that nothing surprises them any more. When we had finished he asked to see our records. Hillyard had them all set down for easy numerical tabulation. Middletown went to work with scarcely a word. Within an hour he had produced a chart that was simply astounding. LATHAM. Can you describe this chart for us? NIEMAND. It was really quite simple. But if it had not been for Middletown's experience in charting other solar phenomena it would never have occurred to us to do it. First, he laid out a series of about thirty squares horizontally across a sheet of graph paper. He dated these beginning March 1, 1955, when our records began. In each square he put a number from 1 to 10 that was a rough index of the number and intensity of the attacks reported on that day. Then he laid out another horizontal row below the first one dated twenty-seven days later. That is, the square under March 1st in the top row was dated March 28th in the row below it. He filled in the chart until he had an array of dozens of rows that included all our data down to May, 1958. When Middletown had finished it was easy to see that the squares of highest index number did not fall at random on the chart. Instead they fell in slightly slanting parallel series so that you could draw straight lines down through them. The connection with the Sun was obvious. LATHAM. In what way? NIEMAND. Why, because twenty-seven days is about the synodic period of solar rotation. That is, if you see a large spot at the center of the Sun's disk today, there is a good chance if it survives that you will see it at the same place twenty-seven days later. But that night Middletown produced another chart that showed the connection with the Sun in a way that was even more convincing. LATHAM. How was that? NIEMAND. I said that the lines drawn down through the days of greatest mental disturbance slanted slightly. On this second chart the squares were dated under one another not at intervals of twenty-seven days, but at intervals of twenty-seven point three days. LATHAM. Why is that so important? NIEMAND. Because the average period of solar rotation in the sunspot zone is not twenty-seven days but twenty-seven point three days. And on this chart the lines did not slant but went vertically downward. The correlation with the synodic rotation of the Sun was practically perfect. LATHAM. But how did you get onto the S-Regions? NIEMAND. Middletown was immediately struck by the resemblance between the chart of mental disturbance and one he had been plotting over the years from his radio observations. Now when he compared the two charts the resemblance between the two was unmistakable. The pattern shown by the chart of mental disturbance corresponded in a striking way with the solar chart but with this difference. The disturbances on the Earth started two days later on the average than the disturbances due to the S-Regions on the Sun. In other words, there was a lag of about forty-eight hours between the two. But otherwise they were almost identical. LATHAM. But if these S-Regions of Middletown's are invisible how could he detect them? NIEMAND. The S-Regions are invisible to the eye through an _optical_ telescope, but are detected with ease by a _radio_ telescope. Middletown had discovered them when he was a graduate student working on radio astronomy in Australia, and he had followed up his researches with the more powerful equipment at Turtle Back Mountain. The formation of an S-Region is heralded by a long series of bursts of a few seconds duration, when the radiation may increase up to several thousand times that of the background intensity. These noise storms have been recorded simultaneously on wavelengths of from one to fifteen meters, which so far is the upper limit of the observations. In a few instances, however, intense bursts have also been detected down to fifty cm. LATHAM. I believe you said the periods of mental disturbance last for about ten or twelve days. How does that tie-in with the S-Regions? NIEMAND. Very closely. You see it takes about twelve days for an S-Region to pass across the face of the Sun, since the synodic rotation is twenty-seven point three days. LATHAM. I should think it would be nearer thirteen or fourteen days. NIEMAND. Apparently an S-Region is not particularly effective when it is just coming on or just going off the disk of the Sun. LATHAM. Are the S-Regions associated with sunspots? NIEMAND. They are connected in this way: that sunspot activity and S-Region activity certainly go together. The more sunspots the more violent and intense is the S-Region activity. But there is not a one-to-one correspondence between sunspots and S-Regions. That is, you cannot connect a particular sunspot group with a particular S-Region. The same thing is true of sunspots and magnetic storms. LATHAM. How do you account for this? NIEMAND. We don't account for it. LATHAM. What other properties of the S-Regions have you discovered? NIEMAND. Middletown says that the radio waves emanating from them are strongly circularly polarized. Moreover, the sense of rotation remains constant while one is passing across the Sun. If the magnetic field associated with an S-Region extends into the high solar corona through which the rays pass, then the sense of rotation corresponds to the ordinary ray of the magneto-ionic theory. LATHAM. Does this mean that the mental disturbances arise from some form of electromagnetic radiation? NIEMAND. We doubt it. As I said before, the charts show a lag of about forty-eight hours between the development of an S-Region and the onset of mental disturbance. This indicates that the malignant energy emanating from an S-Region consists of some highly penetrating form of corpuscular radiation, as yet unidentified.[A] [Footnote A: Middletown believes that the Intense radiation recently discovered from information derived from Explorer I and III has no connection with the corpuscular S-radiation.] LATHAM. A question that puzzles me is why some people are affected by the S-Regions while others are not. NIEMAND. Our latest results indicate that probably _no one_ is completely immune. All are affected in _some_ degree. Just why some should be affected so much more than others is still a matter of speculation. LATHAM. How long does an S-Region last? NIEMAND. An S-Region may have a lifetime of from three to perhaps a dozen solar rotations. Then it dies out and for a time we are free from this malignant radiation. Then a new region develops in perhaps an entirely different region of the Sun. Sometimes there may be several different S-Regions all going at once. LATHAM. Why were not the S-Regions discovered long ago? NIEMAND. Because the radio exploration of the Sun only began since the end of World War II. LATHAM. How does it happen that you only got patients suffering from S-radiation since about 1955? NIEMAND. I think we did get such patients previously but not in large enough numbers to attract attention. Also the present sunspot cycle started its rise to maximum about 1954. LATHAM. Is there no way of escaping the S-radiation? NIEMAND. I'm afraid the only sure way is to keep on the unilluminated side of the Earth which is rather difficult to do. Apparently the corpuscular beam from an S-Region is several degrees wide and not very sharply defined, since its effects are felt simultaneously over the entire continent. Hillyard and Middletown are working on some form of shielding device but so far without success. LATHAM. What is the present state of S-Region activity? NIEMAND. At the present moment there happens to be no S-Region activity on the Sun. But a new one may develop at any time. Also, the outlook for a decrease in activity is not very favorable. Sunspot activity continues at a high level and is steadily mounting in violence. The last sunspot cycle had the highest maximum of any since 1780, but the present cycle bids fair to set an all time record. LATHAM. And so you believe that the S-Regions are the cause of most of the present trouble in the world. That it is not ourselves but something outside ourselves-- NIEMAND. That is the logical outcome of our investigation. We are controlled and swayed by forces which in many cases we are powerless to resist. LATHAM. Could we not be warned of the presence of an S-Region? NIEMAND. The trouble is they seem to develop at random on the Sun. I'm afraid any warning system would be worse than useless. We would be crying WOLF! all the time. LATHAM. How may a person who is not particularly susceptible to this malignant radiation know that one of these regions is active? NIEMAND. If you have a feeling of restlessness and anxiety, if you are unable to concentrate, if you feel suddenly depressed and discouraged about yourself, or are filled with resentment toward the world, then you may be pretty sure that an S-Region is passing across the face of the Sun. Keep a tight rein on yourself. For it seems that evil will always be with us ... as long as the Sun shall continue to shine upon this little world. THE END End of Project Gutenberg's Disturbing Sun, by Robert Shirley Richardson	4,861	common-pile/project_gutenberg_filtered	24150	project gutenberg	project_gutenberg-dolma-0002.json.gz:3980	https://www.gutenberg.org/ebooks/24150.txt.utf-8
GNa3l1dZCt6vT4BL	University Physics Volume 1	17 Sound 17.4 Normal Modes of a Standing Sound Wave Learning Objectives By the end of this section, you will be able to: - Explain the mechanism behind sound-reducing headphones - Describe resonance in a tube closed at one end and open at the other end - Describe resonance in a tube open at both ends Interference is the hallmark of waves, all of which exhibit constructive and destructive interference exactly analogous to that seen for water waves. In fact, one way to prove something “is a wave” is to observe interference effects. Since sound is a wave, we expect it to exhibit interference. Interference of Sound Waves In Waves, we discussed the interference of wave functions that differ only in a phase shift. We found that the wave function resulting from the superposition of [latex]{y}_{1}(x,t)=A\,\text{sin}(kx-\omega t+\varphi )[/latex] and [latex]{y}_{2}(x,t)=A\,\text{sin}(kx-\omega t)[/latex] is One way for two identical waves that are initially in phase to become out of phase with one another is to have the waves travel different distances; that is, they have different path lengths. Sound waves provide an excellent example of a phase shift due to a path difference. As we have discussed, sound waves can basically be modeled as longitudinal waves, where the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When the waves leave the speakers, they move out as spherical waves (Figure). The waves interfere; constructive inference is produced by the combination of two crests or two troughs, as shown. Destructive interference is produced by the combination of a trough and a crest. The phase difference at each point is due to the different path lengths traveled by each wave. When the difference in the path lengths is an integer multiple of a wavelength, the waves are in phase and there is constructive interference. When the difference in path lengths is an odd multiple of a half wavelength, the waves are [latex]180^\circ(\pi \,\text{rad})[/latex] out of phase and the result is destructive interference. These points can be located with a sound-level intensity meter. Example Interference of Sound Waves Two speakers are separated by 5.00 m and are being driven by a signal generator at an unknown frequency. A student with a sound-level meter walks out 6.00 m and down 2.00 m, and finds the first minimum intensity, as shown below. What is the frequency supplied by the signal generator? Assume the wave speed of sound is [latex]v=343.00\,\text{m/s}\text{.}[/latex] Strategy The wave velocity is equal to [latex]v=\frac{\lambda }{T}=\lambda f.[/latex] The frequency is then [latex]f=\frac{v}{\lambda }.[/latex] A minimum intensity indicates destructive interference and the first such point occurs where there is path difference of [latex]\Delta r=\lambda \text{/}2,[/latex] which can be found from the geometry. Solution - Find the path length to the minimum point from each speaker. [latex]{r}_{1}=\sqrt{{(6.00\,\text{m})}^{2}+{(2.00\,\text{m})}^{2}}=6.32\,\text{m,}\enspace{r}_{2}=\sqrt{{(6.00\,\text{m})}^{2}+{(3.00\,\text{m})}^{2}}=6.71\,\text{m}[/latex] - Use the difference in the path length to find the wavelength. [latex]\Delta r=\|{r}_{2}-{r}_{1}\|=\|6.71\,\text{m}-6.32\,\text{m}\|=0.39\,\text{m}[/latex][latex]\lambda =2\Delta r=2(0.39\,\text{m})=0.78\,\text{m}[/latex] - Find the frequency. [latex]f=\frac{v}{\lambda }=\frac{343.00\,\text{m/s}}{0.78\,\text{m}}=439.74\,\text{Hz}[/latex] Significance If point P were a point of maximum intensity, then the path length would be an integer multiple of the wavelength. Check Your Understanding If you walk around two speakers playing music, how come you do not notice places where the music is very loud or very soft, that is, where there is constructive and destructive interference? In the example, the two speakers were producing sound at a single frequency. Music has various frequencies and wavelengths. The concept of a phase shift due to a difference in path length is very important. You will use this concept again in Interference in the second volume of the text and Photons and Matter Waves in the third, where we discuss how Thomas Young used this method in his famous double-slit experiment to provide evidence that light has wavelike properties. Noise Reduction through Destructive Interference Figure shows a clever use of sound interference to cancel noise. Larger-scale applications of active noise reduction by destructive interference have been proposed for entire passenger compartments in commercial aircraft. To obtain destructive interference, a fast electronic analysis is performed, and a second sound is introduced [latex]180^\circ[/latex] out of phase with the original sound, with its maxima and minima exactly reversed from the incoming noise. Sound waves in fluids are pressure waves and are consistent with Pascal’s principle; that is, pressures from two different sources add and subtract like simple numbers. Therefore, positive and negative gauge pressures add to a much smaller pressure, producing a lower-intensity sound. Although completely destructive interference is possible only under the simplest conditions, it is possible to reduce noise levels by 30 dB or more using this technique. Check Your Understanding Describe how noise-canceling headphones differ from standard headphones used to block outside sounds. Regular headphones only block sound waves with a physical barrier. Noise-canceling headphones use destructive interference to reduce the loudness of outside sounds. Where else can we observe sound interference? All sound resonances, such as in musical instruments, are due to constructive and destructive interference. Only the resonant frequencies interfere constructively to form standing waves, whereas others interfere destructively and are absent. Resonance in a Tube Closed at one End As we discussed in Waves, standing waves are formed by two waves moving in opposite directions. When two identical sinusoidal waves move in opposite directions, the waves may be modeled as When these two waves interfere, the resultant wave is a standing wave: Resonance can be produced due to the boundary conditions imposed on a wave. In Waves, we showed that resonance could be produced in a string under tension that had symmetrical boundary conditions, specifically, a node at each end. We defined a node as a fixed point where the string did not move. We found that the symmetrical boundary conditions resulted in some frequencies resonating and producing standing waves, while other frequencies interfere destructively. Sound waves can resonate in a hollow tube, and the frequencies of the sound waves that resonate depend on the boundary conditions. Suppose we have a tube that is closed at one end and open at the other. If we hold a vibrating tuning fork near the open end of the tube, an incident sound wave travels through the tube and reflects off the closed end. The reflected sound has the same frequency and wavelength as the incident sound wave, but is traveling in the opposite direction. At the closed end of the tube, the molecules of air have very little freedom to oscillate, and a node arises. At the open end, the molecules are free to move, and at the right frequency, an antinode occurs. Unlike the symmetrical boundary conditions for the standing waves on the string, the boundary conditions for a tube open at one end and closed at the other end are anti-symmetrical: a node at the closed end and an antinode at the open end. If the tuning fork has just the right frequency, the air column in the tube resonates loudly, but at most frequencies it vibrates very little. This observation just means that the air column has only certain natural frequencies. Consider the lowest frequency that will cause the tube to resonate, producing a loud sound. There will be a node at the closed end and an antinode at the open end, as shown in Figure. The standing wave formed in the tube has an antinode at the open end and a node at the closed end. The distance from a node to an antinode is one-fourth of a wavelength, and this equals the length of the tube; thus, [latex]{\lambda }_{1}=4L.[/latex] This same resonance can be produced by a vibration introduced at or near the closed end of the tube (Figure). It is best to consider this a natural vibration of the air column, independently of how it is induced. Given that maximum air displacements are possible at the open end and none at the closed end, other shorter wavelengths can resonate in the tube, such as the one shown in Figure. Here the standing wave has three-fourths of its wavelength in the tube, or [latex]\frac{3}{4}{\lambda }_{3}=L,[/latex] so that [latex]{\lambda }_{3}=\frac{4}{3}L.[/latex] Continuing this process reveals a whole series of shorter-wavelength and higher-frequency sounds that resonate in the tube. We use specific terms for the resonances in any system. The lowest resonant frequency is called the fundamental, while all higher resonant frequencies are called overtones. All resonant frequencies are integral multiples of the fundamental, and they are collectively called harmonics. The fundamental is the first harmonic, the first overtone is the second harmonic, and so on. Figure shows the fundamental and the first three overtones (the first four harmonics) in a tube closed at one end. The relationship for the resonant wavelengths of a tube closed at one end is Now let us look for a pattern in the resonant frequencies for a simple tube that is closed at one end. The fundamental has [latex]\lambda =4L,[/latex] and frequency is related to wavelength and the speed of sound as given by [latex]v=f\lambda .[/latex] Solving for f in this equation gives where v is the speed of sound in air. Similarly, the first overtone has [latex]\lambda =4L\text{/}3[/latex] (see Figure), so that Because [latex]{f}_{3}=3{f}_{1},[/latex] we call the first overtone the third harmonic. Continuing this process, we see a pattern that can be generalized in a single expression. The resonant frequencies of a tube closed at one end are where [latex]{f}_{1}[/latex] is the fundamental, [latex]{f}_{3}[/latex] is the first overtone, and so on. It is interesting that the resonant frequencies depend on the speed of sound and, hence, on temperature. This dependence poses a noticeable problem for organs in old unheated cathedrals, and it is also the reason why musicians commonly bring their wind instruments to room temperature before playing them. Resonance in a Tube Open at Both Ends Another source of standing waves is a tube that is open at both ends. In this case, the boundary conditions are symmetrical: an antinode at each end. The resonances of tubes open at both ends can be analyzed in a very similar fashion to those for tubes closed at one end. The air columns in tubes open at both ends have maximum air displacements at both ends (Figure). Standing waves form as shown. The relationship for the resonant wavelengths of a tube open at both ends is Based on the fact that a tube open at both ends has maximum air displacements at both ends, and using Figure as a guide, we can see that the resonant frequencies of a tube open at both ends are where [latex]{f}_{1}[/latex] is the fundamental, [latex]{f}_{2}[/latex] is the first overtone, [latex]{f}_{3}[/latex] is the second overtone, and so on. Note that a tube open at both ends has a fundamental frequency twice what it would have if closed at one end. It also has a different spectrum of overtones than a tube closed at one end. Note that a tube open at both ends has symmetrical boundary conditions, similar to the string fixed at both ends discussed in Waves. The relationships for the wavelengths and frequencies of a stringed instrument are the same as given in (Equation) and (Equation). The speed of the wave on the string (from Waves) is [latex]v=\sqrt{\frac{{F}_{T}}{\mu }}.[/latex] The air around the string vibrates at the same frequency as the string, producing sound of the same frequency. The sound wave moves at the speed of sound and the wavelength can be found using [latex]v=\lambda f.[/latex] Check Your Understanding How is it possible to use a standing wave’s node and antinode to determine the length of a closed-end tube? Show Solution When the tube resonates at its natural frequency, the wave’s node is located at the closed end of the tube, and the antinode is located at the open end. The length of the tube is equal to one-fourth of the wavelength of this wave. Thus, if we know the wavelength of the wave, we can determine the length of the tube. This video lets you visualize sound waves. Check Your Understanding You observe two musical instruments that you cannot identify. One plays high-pitched sounds and the other plays low-pitched sounds. How could you determine which is which without hearing either of them play? Show Solution Compare their sizes. High-pitch instruments are generally smaller than low-pitch instruments because they generate a smaller wavelength. Summary - Unwanted sound can be reduced using destructive interference. - Sound has the same properties of interference and resonance as defined for all waves. - In air columns, the lowest-frequency resonance is called the fundamental, whereas all higher resonant frequencies are called overtones. Collectively, they are called harmonics. Conceptual Questions You are given two wind instruments of identical length. One is open at both ends, whereas the other is closed at one end. Which is able to produce the lowest frequency? Show Solution The fundamental wavelength of a tube open at each end is 2L, where the wavelength of a tube open at one end and closed at one end is 4L. The tube open at one end has the lower fundamental frequency, assuming the speed of sound is the same in both tubes. What is the difference between an overtone and a harmonic? Are all harmonics overtones? Are all overtones harmonics? Two identical columns, open at both ends, are in separate rooms. In room A, the temperature is [latex]T=20^\circ\text{C}[/latex] and in room B, the temperature is [latex]T=25^\circ\text{C}[/latex]. A speaker is attached to the end of each tube, causing the tubes to resonate at the fundamental frequency. Is the frequency the same for both tubes? Which has the higher frequency? Show Solution The wavelength in each is twice the length of the tube. The frequency depends on the wavelength and the speed of the sound waves. The frequency in room B is higher because the speed of sound is higher where the temperature is higher. Problems (a) What is the fundamental frequency of a 0.672-m-long tube, open at both ends, on a day when the speed of sound is 344 m/s? (b) What is the frequency of its second harmonic? What is the length of a tube that has a fundamental frequency of 176 Hz and a first overtone of 352 Hz if the speed of sound is 343 m/s? Show Solution 0.974 m The ear canal resonates like a tube closed at one end. (See [link]Figure 17_03_HumEar[/link].) If ear canals range in length from 1.80 to 2.60 cm in an average population, what is the range of fundamental resonant frequencies? Take air temperature to be [latex]37.0^\circ\text{C,}[/latex] which is the same as body temperature. Calculate the first overtone in an ear canal, which resonates like a 2.40-cm-long tube closed at one end, by taking air temperature to be [latex]37.0^\circ\text{C}[/latex]. Is the ear particularly sensitive to such a frequency? (The resonances of the ear canal are complicated by its nonuniform shape, which we shall ignore.) Show Solution 11.0 kHz; The ear is not particularly sensitive to this frequency, so we don’t hear overtones due to the ear canal. A crude approximation of voice production is to consider the breathing passages and mouth to be a resonating tube closed at one end. (a) What is the fundamental frequency if the tube is 0.240 m long, by taking air temperature to be [latex]37.0^\circ\text{C}[/latex]? (b) What would this frequency become if the person replaced the air with helium? Assume the same temperature dependence for helium as for air. A 4.0-m-long pipe, open at one end and closed at one end, is in a room where the temperature is [latex]T=22^\circ\text{C}\text{.}[/latex] A speaker capable of producing variable frequencies is placed at the open end and is used to cause the tube to resonate. (a) What is the wavelength and the frequency of the fundamental frequency? (b) What is the frequency and wavelength of the first overtone? a. [latex]v=344.08\,\text{m/s,}\enspace{\lambda }_{1}=16.00\,\text{m,}\enspace{f}_{1}=21.51\,\text{Hz;}[/latex] b. [latex]{\lambda }_{3}=5.33\,\text{m,}\enspace{f}_{3}=64.56\,\text{Hz}[/latex] A 4.0-m-long pipe, open at both ends, is placed in a room where the temperature is[latex]T=25^\circ\text{C}\text{.}[/latex] A speaker capable of producing variable frequencies is placed at the open end and is used to cause the tube to resonate. (a) What are the wavelength and the frequency of the fundamental frequency? (b) What are the frequency and wavelength of the first overtone? A nylon guitar string is fixed between two lab posts 2.00 m apart. The string has a linear mass density of [latex]\mu =7.20\,\text{g/m}[/latex] and is placed under a tension of 160.00 N. The string is placed next to a tube, open at both ends, of length L. The string is plucked and the tube resonates at the [latex]n=3[/latex] mode. The speed of sound is 343 m/s. What is the length of the tube? Show Solution [latex]\begin{array}{cc} {v}_{\text{string}}=149.07\,\text{m/s,}\enspace{\lambda }_{3}=1.33\,\text{m,}\enspace{f}_{3}=112.08\,\text{Hz}\hfill \\ {\lambda }_{1}=\frac{v}{{f}_{1}},\enspace{L}=1.53\,\text{m}\hfill \end{array}[/latex] A 512-Hz tuning fork is struck and placed next to a tube with a movable piston, creating a tube with a variable length. The piston is slid down the pipe and resonance is reached when the piston is 115.50 cm from the open end. The next resonance is reached when the piston is 82.50 cm from the open end. (a) What is the speed of sound in the tube? (b) How far from the open end will the piston cause the next mode of resonance? Students in a physics lab are asked to find the length of an air column in a tube closed at one end that has a fundamental frequency of 256 Hz. They hold the tube vertically and fill it with water to the top, then lower the water while a 256-Hz tuning fork is rung and listen for the first resonance. (a) What is the air temperature if the resonance occurs for a length of 0.336 m? (b) At what length will they observe the second resonance (first overtone)? Show Solution a. [latex]22.0{}^\circ \text{C}[/latex]; b. 1.01 m Glossary - fundamental - the lowest-frequency resonance - harmonics - the term used to refer collectively to the fundamental and its overtones - overtones - all resonant frequencies higher than the fundamental	3,881	common-pile/pressbooks_filtered	https://pressbooks.online.ucf.edu/osuniversityphysics/chapter/17-4-normal-modes-of-a-standing-sound-wave/	pressbooks	pressbooks-0000.json.gz:93999	https://pressbooks.online.ucf.edu/osuniversityphysics/chapter/17-4-normal-modes-of-a-standing-sound-wave/
4glRVT1w6-z2zZqC	Learning Environments Design Reading Series	28 Wilson, M. (2002). Six views of embodied cognition. Psychonomic Bulletin & Review, 9(4), 625-636. Retrieved from https://link.springer.com/article/10.3758/BF03196322. Background: Since the dawn of psychology, the prevalent idea has been that the mind is separate from the body, and that if scientists can recreate the mind, humanity can recreate humans. Recent emerging schools of thought, coupled with new research, however, suggest that might not be the case. There is ever-growing steam in the field of embodied cognition- or the idea that the body’s experiences influences the mind, and creates some very important aspects of the mind, particularly in regard to emotion. Key Points: There are six claims made by proponents of embodied cognition, some of which have merit, and some of which need more research to be founded: - “Cognition is situated” This means that cognition is situated within outside contexts. Contexts that are task-dependent, and dependent on bodily input and outputs. Examples include driving, rearranging furniture, or participating in conversation while walking. While there are also some cognitive activities that do not rely on outside input/output (memories, planning, imagining circumstances), it can be said that perhaps the foundation of cognition is rooted in early human’s ability to think and plan in tune with the environment. - “Cognition is time-pressured” Cognition occurs in real-time, with real-events on a time line, such as getting away from a predator in time, or surveying upcoming terrain, and choosing how to move the body while running. - “We off-load cognitive work onto the environment” That is to say, that humans will sometimes use the environment in order to avoid using cognition to complete tasks. However this point may only be limited to spatial and representational tasks, not all cognitive tasks. - “The environment is part of the cognitive system” Cognition is spread across the mind, body, and environment. Forces that drive cognition are not based in the mind, but are a culmination of what goes on in a system. - “Cognition is for action” Cognition and memory are created for use with the real, physical world. However, there are some examples that negate this claim (recognizing faces, appreciating a sunset). - “Offline cognition is body based” Mental imagery, working memory, episodic memory, reasoning and problem solving and implicit memory, and how they work better or worse depending on bodily movements during tasks are all examples of how offline cognition is body based. Design principles: Embodied cognition should be used in learning design, as it has been shown that cognition is rooted in the mind, space and body. If educators and learning designers can use this theory to create programs and curriculums, students should be able to learn complicated concepts, especially in fields where spatial thinking is important such as mathematics, engineering and hard sciences. Example work: Over the past several decades, many experiments have been conducted in order to prove the theory of embodied cognition. In one such study, researchers asked participants to view gender-neutral faces while squeezing a ball. If the ball was soft, people perceived the faces to be female, if the ball was hard, people perceived the faces to be male. This shows how physical experiences shape the mind. Discussion Questions - What further research would need to be done to either confirm or discount the claim that “the environment is part of the cognitive system?” - How can embodied cognition be used in curriculum design in order to promote learning? What subjects would the use of embodied cognition-based curriculum be most effective? - What are some ways a person can strengthen their ability to think in an embodied manner?’ Additional Resources: - Booth, W.C. (1983). Metaphors We Live By. George Lakoff, Mark Johnson. Ethics, 93(3), 619-621. - THUNK. (2018 Feb 10). 137. Embodied Cognition. [Video file]. Retrieved from https://www.youtube.com/watch?v=NDw_1UyNTKI. References Slepian, M. L., Weisbuch, M., Rule, N. O., & Ambady, N. (2010). Tough and Tender. Psychological Science,22(1), 26-28. Retrieved from http://ambadylab.stanford.edu/pubs/2011_Slepian-et-al_ToughandTender.pdf	845	common-pile/pressbooks_filtered	https://pressbooks.pub/learningenvironmentsdesign/chapter/wilson-six-views-of-embodied-cognition/	pressbooks	pressbooks-0000.json.gz:14751	https://pressbooks.pub/learningenvironmentsdesign/chapter/wilson-six-views-of-embodied-cognition/
27F-O7ghCJ6zZmNR	Resources for Teaching Climate Change Across the Curriculum	6 Social Sciences Who suffers first and most? Who is responsible? What are the barriers and opportunities for change? These are key questions society must address and they fall squarely in the realm of the social science classroom. Climate change means that entire societies and peoples will be upended as the result of their recent ancestors choices and behaviors[1]. Who better to help our students understand and prepare for this upheaval than their history, sociology, political science, and philosophy instructors? These are the subjects where we address what we do when our way of life is ending, where we glean lessons from history and evaluate tales of surrender and compromise vs. resistance and violence[2]. They are the subjects that provide the tools for working within and outside of governmental systems for change. They are also the setting in which we wrestle with the moral and ethical underpinnings of our actions and ask critical questions about humanity’s relationship to nature and “whether our religious heritage, centered on human beings and the divine, keep[s] us from fully apprehending our peril”[3]. Or, what does it mean to be stewards of the Earth? How do humans respond to long-term threats? How do we engage in challenging issues? What is the psychology of ideology and identity and how does this influence how we approach wicked problems? Here the psychology classroom can play a critical role. And how do we cope with the reality we face? What can we do for self-care? Below are ideas for places to insert lessons into your classrooms and descriptions of how your colleagues are already doing so. Sociology, History, and Political Science - IPCC. 2014. “Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II, and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri Adn L.A. Meyer (Eds).].” Geneva, Switzerland. ↵ - Fretz, Eric J., ed. 2016. Climate Change across the Curriculum. Lanham, Maryland: Lexington Books. ↵ - McKibben, Bill in Foreword to Fretz, Eric J., ed. 2016. Climate Change across the Curriculum. Lanham, Maryland: Lexington Books. ↵	453	common-pile/pressbooks_filtered	https://mhcc.pressbooks.pub/teachingclimatechange/chapter/social-sciences/	pressbooks	pressbooks-0000.json.gz:4385	https://mhcc.pressbooks.pub/teachingclimatechange/chapter/social-sciences/
CYkz4Fh99c-4YseK	A practical text-book of infection, immunity, and specific therapy, with special reference to immunologic technic.	JOHN A. KOLMER, M.D., DR.P.H., M.Sc. Assistant Professor of Experimental Pathology, University of Pennsylvania; Professor of Pathology and Bacteriology, Philadelphia Polyclinic, and Pathologist to the Department of Dermatologic Research; Pathologist to the Philadelphia Hospital for Contagious Diseases INTRODUCTION THE last quarter of a century has witnessed an almost marvelous development of knowledge in the domain of medicine and the allied sciences, only a part, of course, of the extensive progress made in the field of general science. A striking portion of this advance has tended to broaden our knowledge of the principles and of the essential details of the processes of infection and immunity, until these branches have today come to form almost a special science in themselves — an imperium in imperio. Aside from the personal factor, the writer's immediate interest in the present volume, as originally projected, arose from the fact that he was desirous of having appear a series of exercises illustrative of the principles of immunology — a class-book intended to set forth in' permanent form the very excellent course of instruction that Dr. Kolmer has been giving during the past few years to selected groups of interested students and occasional post-graduate workers in the Medical School of the University of Pennsylvania. That it should have surpassed the original simple plan and grown into a volume of the present proportions is scarcely to be wondered at/ if the temptation to elaborate the individual exercises by explanations and cognate considerations was in the slightest to be yielded to. This is due to the fact that in its growth the subject has acquired so much of undoubted importance in the form of isolated observed facts, and itself presents so many analogies and has led to so extensive a terminology, that the author who would attempt to link the observed facts into anything like logical sequence or to add in the least to the bare cook-book-like series of illustrative exercises any explanatory paragraphs, cannot avoid the fullness that Dr. Kolmer has found inevitable in presenting the subject. The branch of immunology, including primarily infection, and its ramifications into diagnosis and the actual treatment of disease, has brought to the parent subject of preventive medicine the greatest offering of the decades of its growth. Itself contributing to world expansion, it has nowhere found a greater stimulus than in the field of exotic pathology; and this last, in turn, has enriched internal medicine, even in its most common aspects. The first step in immunology may properly be ascribed to Jenner, with his bovine vaccine for smallpox, a step followed only after a long lapse of years by Pasteur. On the heels of the latter there appeared at once, and has since then followed, an army of men whose names crowd the history of the subject, and which many of these are bound permanently to adorn. The old vague theories of infection have taken form, and to observed facts has been added productive theory. The great danger attending this luxurious development is that, temporarily at least, the simpler, and perhaps the more obvious, facts are likely to be neglected; and, also, that symbolization by theories elaborated to harmonize with discovered facts will be accepted too fully as explanatory when in reality it does not explain, and that, as a result, investigation will finally be hampered instead of aided. In the almost universal drift of experimental studies to internal stereochemical factors, are we not in danger of placing too little stress upon actual and possible physical factors? Is there no danger that, by failing to lay stress upon the obvious importance of the turbinate mechanism in the nose as a natural anatomic factor, our rhinologists may at least feel justified in sacrificing this mechanism too readily for what may be but trivial local reasons? Can we insist that every phenomenon described with facility in terms of the side-chain theory is really a manifestation of chemism, when perhaps, with added investigation along lines of physical absorption and the physical properties of colloids, an equally satisfying conception may be had, and possibly new facts be developed? Are we not blundering in rushing madly after matters of specificity as determined by antigen, when perhaps in reality we are confronted by potential and kinetic modifications due to peculiarities of diet or environmental circumstances? The verity of phagocytosis is open to proof by observation, and its variations are likewise to be demonstrated. Is the explanation of opsonins so convincing that merely the word itself is enough to satisfy the investigator? Infection and immunity constitute a definite chapter in pathologic science. The processes lack the dignity of a separate science only in that they present variations, and the fact that these are glossed over by brilliant theories and conceptions cannot prevent the deliberate recognition of serious incompleteness. Yet this criticism can be applied to the growth of every branch of scientific knowledge. It in no wise militates against the right and the need for setting forth the subject in the light that, for the time, is afforded it. The importance of the criticism lies only in its acknowledgment, lest the subject as at present understood be accepted as fixed. With this danger obviated, and with all theories accepted for the time only as working theories, and their adoption not can be heartily applauded. This is the view that the writer believes that Dr. Kolmer has had in mind in his presentation of the subject as here set down. It is certainly true of the chapters that the present writer has had opportunity of examining. In such a sense, therefore, the work is urged on the appreciation of the student, whether a laboratory worker or a mere seeker of knowledge. I have often been asked to what extent I believe it profitable to present the subject to the undergraduate student. I do not hesitate to answer that so far as the roster of the medical curriculum will permit, the laboratory demonstrations and exercises should form a part of the required course; and that, with all due caution to emphasize the fact that our present theory is not known to be final, and is offered merely tentatively, the verbal picture of the subject should be outlined before these beginners. To form some conception is necessary; and it is better, provided the mind be kept receptive, to follow a certain theory, even if it is unproved, than to do nothing at all or to work in confusion. Our American medical curriculum for undergraduates is so crowded with absolute essentials that the present subject is habitually neglected, save for a rapid lecture outline; this is an injustice to the student and to American medicine. I have tried to minimize this by providing, through Dr. Kolmer's aid, a reasonable laboratory course in the essentials of the branch to volunteer classes at first, at hours that did not interfere with the regular curriculum — at present during periods open to election. Nevertheless, the subject, influencing as it does every branch of medical practice, must take its place with other commendable additions to the required schedule. That this can be done only by lengthening the course of study, either in the annual session or by adding a year to our present four-year course, is obvious, and to that end we are rapidly approaching. PREFACE TO THE SECOND EDITION THE purpose and general plan of this volume remains unchanged in this edition. I have endeavored to make it a practical treatise for medical students, practitioners, and laboratory workers by setting forth theories and opinions simply and plainly, and devoting particular attention to technic and the practical phases and application of the subjects considered; I hope that this edition will receive the same generous recognition as its predecessor. Additions and alterations have been made throughout; special attention has been given the subject of focal infection; the Schick toxin test for immunity in diphtheria and active immunization in diphtheria with toxin-antitoxin mixtures; complement-fixation in tuberculosis and other bacterial infections and a quantitative Wassermann reaction based upon my studies with the co-operation and assistance of Dr. Claude P. Brown, Dr. Toitsu Matsunami, and Dr. Berta Meine, aiming to standardize this important test. The chapters on anaphylaxis have been revised and particular attention given the subject of anaphylactic skin reactions. Lange's colloidal gold reaction has been included. The chapter on the treatment of various infections with bacterial vaccines has been enlarged and the non-specific activity of bacterial vaccines discussed. The section on the treatment of certain of the acute infectious diseases, and particularly acute anterior poliomyelitis, with the serum of convalescents and normal persons has been amplified; blood transfusion has been included. Special attention has been devoted to the chapter on Chemotherapy, and the results of the studies of Dr. Jay F. Schamberg, Dr. George Raiziss, and the author bearing upon the toxicity of salvarsan and its congeners and the reactions following their administration have been included and discussed. The subject of Bacterial Chemotherapy, which promises much in the future, has been amplified from the theoretical and technical viewpoints. The section on Experimental Infection and Immunity remains as part of the volume instead of forming a separate book; experience has shown that this is a good plan, and enables the student doing more or less independent work to consult the text for directions and discussions. PREFACE FOR the past twenty years the science of immunity has been one of the most progressive and most active branches in the department of medicine. An enormous literature has accumulated; many new terms have been coined, and numerous theories have been adduced; indeed, the subject has acquired an aspect of complexity that is confusing to those not specially interested or engaged in this work. The purpose of this book is a threefold one, namely : 1 . To give to practitioners and students of medicine a connected and concise account of our present knowledge regarding the manner in which the body may become infected, and the. method, in turn, by which the organism serves to protect itself against infection, or strives to overcome the infection if it should occur, and also to present a practical application of this knowledge to the diagnosis, prevention, and treatment of disease. branches. 1. The subject of infection is intimately connected with that of immunity, and this is especially emphasized in those diseases for which a specific therapy exists, for a knowledge of the nature of the infection is of paramount importance in controlling the dosage and indicating the method of administration of a specific therapeutic agent. By describing principles and technic with considerable detail, a special effort has been made to render Part IV of this book of particular value to practitioners of medicine. The day is past when the physician and surgeon can relegate the things of immunity entirely to the laboratory. Diagnostic methods and reactions and the field of specific therapy, — vaccine, serum, and chemo-, — are subjects of such practical importance that it is obvious that the physician and the student of medicine can no longer be merely mildly interested onlookers. The physician who injects salvarsan, a serum, or a vaccine, or who uses a diagnostic reaction, must be prepared to explain to his patient the nature of the therapy he employs and the sig- nificance of the reaction. This he can do only by equipping himself with the knowledge of the fundamental factors of immunity, or he will be forced into the position of a passive transmitter of ideas entirely beyond his own knowledge. 2. An effort has been made to include data of both practical and theoretic importance, and in some instances tests are described that are more of theoretic than of practical import, especially in research work. » It is obviously impossible, in a single volume, to include the very large number of tests and modifications that have been advocated from time to time, and, as a matter of course, most attention has been given those methods that have been shown to be of practical value or that give promise of becoming so. So far as possible original methods are given, these being, in the larger proportion, more or less important modifications devised as the result of my own experience in hospital and teaching laboratories. The technic of the various tests and reactions is described in great detail, thus tending the better to secure accuracy, simplicity, and definiteness, and to serve as an opening wedge to those about to enter this special field. 3. The value of the experimental method in the teaching of certain branches of medicine is now well recognized. In no department, however, is this method of greater value than in the study of infection and immunity. A working knowledge of these subjects is so valuable in the practice of medicine and surgery that the student should be well versed in at least their primary principles and practical applications in the prophylaxis, diagnosis, and treatment of diseas The laboratory course given in Part V is based upon the courses given by me in the Laboratory of Experimental Pathology at the University of Pennsylvania, and in the laboratories of the Philadelphia Polyclinic and College for Graduates in Medicine. In including them in this volume I am carrying out my original plan, for in many of the experiments the exact technic of a given test is described, making a separate book devoted to this part of the subject unnecessary. Future experience may, however, show the necessity of having this portion of the book form a separate laboratory manual. I shall appreciate the opinions of educators who may have occasion to consult the course herein outlined. Since the larger portion of our knowledge of infection and immunity has been gained from studies upon the lower animals, it is not strange that these were early and directly benefited by a practical application of this knowledge to the prophylaxis, diagnosis, and treatment of many of the diseases to which these animals are subject. I have, therefore, included in this volume an account of those immunologic diagnostic reactions and applications of specific therapy that have a direct bearing upon veterinary medicine. No attempt has been made to cover all literature references on the subject. An effort has been made to state well-established facts concisely, and, in the case of the more recent subjects, to give the principal references to the literature. I have drawn largely from German, French, and English sources, and have endeavored, wherever possible, to give proper and due credit to each author. In order to keep the work up to the times, I would ask the authors of reprints on immunologic subjects to send me copies. The illustrations, all of which have been made by Mr. Erwin F. Faber, will, it is hoped, serve the purpose for which they are intended, namely, to elucidate the text and to teach, rather than merely to embellish. It is with deep and sincere appreciation that I acknowledge the encouragement and aid given me by Professor Allen J. Smith, who has written the introduction and reviewed several chapters. My thanks are also due to Professor Richard M. Pearce for reviewing the chapters on Infection; to my assistant, Dr. Anna M. Raiziss, for a number of translations from foreign literature, and to the publishers, whose kind and unvarying courtesy has greatly simplified the work. Care of centrifuge, 17 — Making a simple capillary pipet, 18 — Making looped pipets, 20 — Graduated pipets, 21 — Making Wright blood-capsules, -23 — Making vaccine ampules, 24 — Preparation of test-tubes for immunologic work, 25 — Selection of a satisfactory syringe, 26 — Solutions, 27. General rules, 53 — Method of subcutaneous inoculation (fluid and solid inocula), 54 — Method of intramuscular inoculation, 56 — Methods of intravenous inoculation (rabbit, guinea-pig, mice and rats, horse, sheep, goat, dog), 56 — Method of intracardial inoculation, 62 — Methods of intraperitoneal inoculation (rabbit, guinea-pig), 64. Antigens and active immunization, 65 — General technic, 66 — Production of antitoxins, 68 — Production of agglutinins (intravenous and intraperitoneal inoculation), 68 — Production of immune opsonins, 69 — Production of bacteriolysins, 69 — Production of precipitins, 70 — Production of hemolysins (intravenous and intraperitoneal inoculations), 71 — Production of cytotoxins, 73. Methods for the preservation of normal serums, 75 — Methods for the preservation of immune serum in fluid form with antiseptics, 76 — In fluid form by bacteria-free filtrations, 76 — In fluid form by freezing, 79 — Preservation in powder form, 79 — Preservation in dried paper form, 80. Definition, 81 — Relation of infection to immunity, 83 — Source of infection, 83 — Contagious and infectious diseases, 84 — Exogenous and endogenous infection, 85— -Avenues of infection, 86 — Normal defenses against bacterial invasion, 90 — Mechanism of bacterial invasion, 91 — Local infection, 94 — Mechanism of infection, 94 — The avenue of infection and tissue susceptibility, 98 — The numeric relationship of bacteria to infection, 99 — General susceptibility in relation to infection, 100 — The defensive mechanism of the microorganism in relation to infection, 103 — Mixed infection, 106 — Summary, 107. Toxins, 109 — Extracellular bacterial toxins, 110 — General properties of soluble toxins, 110— Precipitation of the extracellular toxins, 111 — Structure of soluble toxins, 111 — Nature of soluble toxins, 112 — Selective action of soluble toxins, 112. Special Properties of the Principal Soluble Toxins, 113 — Diphtheria toxin, 113 — The guinea-pig test for virulence of diphtheria bacilli, 114 — Tetanus toxin, 117 — Botulism toxin, 117 — Dysentery toxin, 118 — Staphylotoxin, 118— Streptotoxin, 119. Toxins of the Higher Plants and Animals, 119 — Phytotoxins, 119 — Pollen toxin, 120— Zootoxins, 121 — Snake venom, 121. Endotoxins, 122 — Methods of studying endotoxins, 122 — Nature of endotoxins, 123 — Aggressins, 124 — Bail's classification of bacteria, 125 — Nature of aggressins, 126 — Anti-aggressins, 127 — .Bacterial Proteins, 127 — Bacterial split protein, 128 — Nature of bacterial proteins, 128 — Action of bacterial proteins, 129 — Theory of Vaughan, 130. Ptomains, 131. Mechanical Action of Bacteria, 133 — Infection with Animal Parasites, 134 — The Course of Infection, 136 — Stages of infection, 136 — Grades of Infection, 138 — Systemic reaction to infection, 139. Definition, 142 — Historic, 142 — Exhaustion theory of immunity, 143 — Retention theory of immunity, 146 — Theory of phagocytosis, 146 — Side-chain theory of immunity, 148 — Compatibility of the phagocytic and side-chain theories, 157 — Antigens, 161 — Antibodies, 163. Natural Immunity, 167 — Explanation of natural immunity, 168 — Nonspecific immunity, 168 — Local immunity, 169 — Phagocytosis and natural immunity, 170— Natural antitoxic immunity, 171 — Natural bacteriolytic immunity, 171 — Natural anti-aggressin immunity, 171 — Athreptic immunity, 172. Acquired Immunity, 172 — Active acquired immunity, 172 — Passive acquired immunity, 174. Historic, 177 — The original theory of phagocytosis, 178— Kinds of phagocytosis, 179 — The relation of the cell types to infection, 180 — Chemotaxis, 181 — Positive chemotaxis, 181 — Negative chemotaxis, 184 — Results of phagocytosis, 184 — The relation of body fluids to phagocytosis, 186 — Revised theory and role of phagocytosis in immunity, 188 — Mechanism of phagocytosis, 189. Principles involved, 194 — Definition, 194 — Purpose of the opsonic index, 195— Limitations of the method, 195 — Precautions in technic, 196— Technic of the opsonic index (Wright), 196 — Technic of quantitative estimation of bacteriotropins in immune serum (Neufeld), 203 — Practical value of the opsonic index, 206 — Value of the index in diagnosis, 207 — In prognosis, 208 — As a guide to bacterial vaccine therapy, 208. Definition, 210 — Technic of preparing bacterial vaccines, 210— Counting a bacterial vaccine (method of Wright), 214 — Counting with the hemocytometer chamber, 215— Method of Kolle, 216— Method of Hopkins, 216— Preparation of "sensitized" bacterial vaccine, 221 — The administration of a bacterial vaccine, 221 — Making the inoculation, 221 — Effects of inoculation, 222— Frequency and dosage of inoculation, 222 — Ordinary adult doses of the common vaccines, 222. Definition, 224 — Historic, 224 — Formation of antitoxins, 225 — Structure of antitoxins, 227 — Properties of antitoxins, 227 — Natural antitoxins, 228 — Schick test for natural diphtheria antitoxin, 228 — Specificity of antitoxins, 232 — Nature of the toxin-antitoxin reaction, 232 — Production of Diphtheria Antitoxin, 235 — Production of diphtheria toxin, 235 — Testing the toxin, 236 — Immunizing the animals, 236 — Collecting the serum, 239 — Method of concentrating, 239— Standardizing the serum, 240. Production of Tetanus Antitoxin, 243 —Tetanus toxin, 243 — Immunizing the animals, 244 — Collecting the serum, 244 — Standardizing the serum, 244. Botulimis Antitoxin, 245. Antidysentery Serum, 245 — The culture, 246 — Immunizing the animals, 247 — Rapid production, 247 — Collecting and testing the serum, 248. Antistaphylococcus Serum, 249 — Preparation, 249 — Technic of the anti-lysin test, 249. Production of Antivenin, 251. Production of Pollen Antitoxin, 252. The Measure of Antitoxins, 252 — A unit, 252 — Unit of diphtheria antitoxin, 253 — Unit of tetanus antitoxin, 253. Bacterial ferments, 254 — Similarity between toxins and ferments, 254 — Antif erments, 256 — Antibodies and antiferments, 257 — Antiferments in disease, 257 — Ferments in pregnancy and disease, 258. Mechanism of the Abderhalden reaction, 260. Ferment Reactions, 264— Antitrypsin test, 264— Abderhalden 's serodiagnosis of pregnancy, 265 — Practical value of Abderhalden's test, 276 — Sero-enzymes in cancer, 277 — In mental diseases, 278 — In syphilis, 278 — In tuberculosis and acute infection, 278. Definition, 279 — Historic, 279— Normal and immune agglutinins, 281 — Formation of agglutinins, 281 — Origin of agglutinins, 282 — Properties and nature of agglutinins, 283 — Acid agglutination, 283 — Mechanism of agglutination, 284 — Specificity of agglutinins, 285 — Absorption methods for differentiating between a mixed and single infection, 285 — Hemagglutinins, 286 — Non-agglutinable species of bacteria, 288 — Variation in agglutinating strength of a serum, 288 — Conglutination, 289 — Role of agglutinins in immunity, 289. Practical Applications, 290 — In the diagnosis of typhoid fever, 290 — Paratyphoid fever, 291 — Dysentery, 292 — Cholera, 292— Cerebrospinal meningitis, 292— Plague, 292— Malta fever, 292— Pneumonia, 292— Syphilis, 292— Pertussis, 293 — Glanders, 293 — In the differentiation of bacteria, 293 — In the diagnosis of single and mixed infection, 294. The Agglutination Reaction, 294— Microscopic method with serum, 290 — Microscopic method with dried blood, 300 — Macroscopic method, 301 — Differentiation of pneumococci, 308 — The saturation test of Castellani, 309 — Technic of acid agglutination, 310. Tests before Blood Transfusion for Isohemagglutinins and Isohemolysins, 311 — Microscopic method of Brem, 312. Definition, 314 — Historic, 314 — Nomenclature, 316 — Structure and proportion of precipitins, 316 — Formation of precipitins, 317 — Mechanism of precipitation, 318 — Specificity of precipitins, 318 — Role of precipitins in immunity, 319. Practical Applications, 320 — Bacterial precipitins, 320 — Fornet ring test, 321 — Porges-Meier reaction, 321 — Herman-Perutz reaction, 322— Noguchi globulin reaction, 322 — McDonagh ''gel" test, 323 — Differentiation of proteins, 324. Technic of the Precipitin Reactions, 326 — Differentiation of human and animal bloods, 326 — Detection of meat adulteration, 333 — Bacterial precipitins, 336. Definition, 339 — Kinds of cytolysins, 340 — Nomenclature, 340. Amboceptors, 341 — Historic, 341 — Structure of amboceptors, 342 — General properties of amboceptors, 343 — Mechanism of the action of amboceptors, 343 — Formation of amboceptors, 344 — Quantitative estimation of amboceptors, 347 — Titration of hemolytic amboceptor, 347 — Titration of bacteriolytic amboceptor, 347. Complements, 348 — Historic, 348 — Definition, 348 — Structure and general properties of complement, 348 — Anticomplements, 349— Origin of complements, 350 — Multiplicity of complements, 350 — Endocomplements, 352 — Complementsplitting, 353 — Complement fixation, 354 — Complement deviation, 355 — Quantitative titration of complement, 356. Historic, 358 — Definition, 359 — Origin of bacteriolysins, 360 — Leukins and leukocytic extracts, 360 — Method of preparing leukocytic extracts, 361 — Mechanism of bacteriolysis, 362 — General properties of bacteriolysins, 363 — Normal bacteriolysins, 363 — Specificity of bacteriolysins, 363. Practical Applications, 363— Technic of the Pfeiffer test, 364 — Bacteriolytic test in vivo f9r the identification of bacteria, 365 — Bacteriolytic test in vivo in the diagnosis of disease, 370 — Bacteriolytic test in vitro (method of Stem and Korte), 371 — Bacteriolytic test in vitro (method of Wright), 377. Historic, 383 — Definition, 384 — Nomenclature, 385 — Nature of hemolysins, 385 — Analogy between bacteriolysis and hemolysis, 389 — Specificity of hemolysins, 390 — Normal hemolysins, 390 — Production of immune hemolysins, 393 — General properties of hemolysins, 393 — Source of hemolysins, 394. Practical Applications, 395 — Quantitative reactions between hemolytic amboceptor and complement, 396 — Method of titration of hemolysin, 397 — Method for removing hemolysin from a serum, 400 — Method of determining natural hemolysins in serum, 400-^The serum diagnosis of paroxysmal hemoglobinuria, 401 — Method of determining the resistance of red blood-corpuscles, 402. Historic — nature of venom hemolysis, 405— Venom hemolysis in syphilis, 407 — Practical value of the venom test in syphilis, 410 — The psycho-reaction of Much in syphilis, 410 — Venom hemolysis in tuberculosis, 412 — Venom hemolysis in cancer, 412. Historic, 413 — The original complement-fixation method of Bordet, 416 — Mechanism of complement fixation, 417 — Non-specific complement fixation, 418 — Quantitative factors in complement-fixation tests, 421 — Practical applications, 423. The Wassermann Syphilis Reaction, 425 — Historic, 425 — Principles and theories of the syphilis reaction, 428 — General technic, 431 — Preparation of the fluid to be tested, 432 — Preparation and titration of complement, 435— Preservation of complement, 437 — Preparation and titration of hemolytic amboceptor, 439 — Preparation of blood-corpuscles, 440 — Preparation and standardization of antigens, 441— Technic of the First Method, 459— Technic of the Second Method, 465-^Technic of the Third Method, 467 — Technic of the Fourth Method, 470. Modifications of the Wassermann Reaction, 475 — Technic of the Noguchi modification, 476 — Technic of the Hecht-Gradwohl modification, 482 — Other modifications, 484. The Wassermann Reactions in the Various Stages of Syphilis, 485 — The specificity of the Wassermann reaction, 490 — The effect of treatment upon the Wassermann reaction, 492 — The Practical Value of the Wassermann reaction, 495. Specific complement fixation in bacterial diseases, 498 — Preparation of bacterial antigens, 498 — Standardizing bacterial antigens, 500 — Principles of complement fixation with bacterial antigens, 501. Complement Fixation in the Differentiation of Microparasites, 502. Complement Fixation in Gonococcus Infections, 503. Complement Fixation in Glanders, 511. Complement Fixation in Contagious Abortion, 513. Complement Fixation in Dourine, 515. Complement Fixation in Typhoid Fever, 516. Complement Fixation in Tuberculosis, 517. Complement Fixation in Pertussis, 521. Complement Fixation in the Standardization of Immune Serums, 524. Complement Fixation in Echinococcus Disease, 524. Complement Fixation in the Differentiation of Proteins (blood-stains, meats, bacteria), 527. Complement Fixation in Cancer, 532. Nomenclature, 534 — Nature and general properties of cytotoxins, 534 — Preparation of cytotoxins, 535 — Methods of studying cytotoxins, 535 — Specificity of cytotoxins, 536 — Autocytotoxins, 537 — Isocytotoxins, 538 — Anticytotoxic serums, 538 — Kinds of cytotoxins, 538 — Spermatotoxin, 538 — Epitheliotoxin, 538 — Leukotoxin, 538 — Nephrotoxin, 538 — Hepatotoxin, 539 — Gastrotoxin, 539 — Syncytotoxin, 539 — Neurotoxin, 540 — Thyrotoxin, 540 — Role of cytotoxins in immunity, 540 — Practical applications, 540 — Cytotoxic cancer reaction, 541. Kinds of colloids, 543 — Nature and properties of colloids, 543 — Analogy between the reactions of immunity and those of colloidal chemistry, 548 — Antitoxins, 548 — Agglutinins and precipitins, 55fr— Hemolysins, 551 — Complement fixation as a colloid reaction, 552 — The relation of lipoids to immunity, 553 — Lange's colloidal gold reaction, 555 — The epiphanin reaction, 559 — The miostagmin reaction, 563. Historic, 568 — Definition, 571 — Phenomena of anaphylaxis, 572 — Mechanism of anaphylaxis, 577 — Anaphylactogens or allergens, 579 — The humeral or anaphylotoxin theories of anaphylaxis, 584 — Anaphylactin (allergin), 588 — Theories of anaphylaxis, 591 — Cellular theory of anaphylaxis, 594r— Passive anaphylaxis, 596 — Anti-anaphylaxis or desensitization, 599 — Specificity of anaphylaxis, 601. MUNITY. ANAPHYLACTIC OR ALLERGIC REACTIONS 602 Relation of anaphylaxis to infectious diseases, 603 — Relation of anaphylaxis to non-infectious diseases, 608 — Serum disease, 608 — Idiosyncrasies, 614 — Relation of anaphylaxis to immunity, 618 — Anaphylactic or allergic skin reactions, 620 — Subcutaneous tuberculin reaction, 633 — Intracutaneous tuberculin reaction, 636 — Cutaneous tuberculin reaction, 637 — Conjunctival tuberculin reaction, 639 — Percutaneous tuberculin reaction, 640— Tuberculin reactions among the lower animals, 641 — The luetin reaction, 642 — The mallein reaction, 647 — Abortin reaction, 648— Allergic reactions in typhoid fever, 649 — Allergic reactions in other diseases, 652. AND TREATMENT OF DISEASE. VACCINE THERAPY 654 Historic, 654 — Nomenclature, 656 — Method of preparing vaccines, 657 — Mechanism of active immunization, 659 — Non-specific activity, 663 — Living versus dead vaccines, 664 — Sensitized vaccines, 665 — Autogenous versus stock bacterial vaccines, 665 — The negative phase, 666 — Contraindications to active immunization, 667. Prophylactic Irtimunization or Vaccination, 668 — In small- ?ox, 668 — In rabies, 681 — In typhoid fever, 688 — In paratyphoid fever, 693 — n typhus fever, 694 — In pneumonia, 694 — In plague, 694 — In cholera, 697 — In dysentery, 699 — In cerebrospinal meningitis, 699 — In scarlet fever, 699 — In pertussis, 700 — In anthrax, 700 — In black-leg, 702. Therapeutic Immunization, Bacterial Vaccine Therapy, 702— Principles, 702— Infected wounds, 703 — Focal infections, 704 — Diseases of the skin, 704 — Diseases of the genito-urinary system, 706 — Diseases of the respiratory system, 708 — Acute general infections, 713— Tuberculin therapy, 713. Definition, 733— Purposes of passive immunization, 734 — Kinds of passive immunity, 735 — Indications for passive immunization, 736 — Contraindications to passive immunization, 738 — Technic of subcutaneous inoculation, 740 — Technic of intramuscular inoculation, 742 — Technic of intravenous inoculation, 742 — Technic of subdural inoculation, 746. Serum Treatment and Prophylaxis of Diphtheria, 754. Serum Treatment and Prophylaxis of Tetanus, 772. Serum Treatment and Prophylaxis of Dysentery, 782. Serum Treatment and Prophylaxis of Hog Cholera, 784. Serum Treatment of Snake Bites, 786. Serum Treatment and Prophylaxis of Hay-fever, 786. Serum Treatment and Prophylaxis of Meningococcus Meningitis, 788. Serum Treatment of Influenzal Meningitis, 802. Serum Treatment of Pneumococcus Meningitis, 804. Serum Treatment of Other Localized Pneumococcus Infections, 807. Serum Treatment of Lobar Pneumonia, 807. Serum Treatment of Streptococcus Infections, 813. Serum Treatment of Gonococcus Infections, 818. Serum Treatment of Staphylococcus Infections, 819. Serum Treatment of Anthrax, 820. Serum Treatment of Typhoid Fever, 821. Serum Treatment of Plague, 822. Serum Treatment of Cholera, 823. Serum Treatment of Tuberculosis, 824. Treatment of Infectious Diseases with Specific Serum of Convalescents and with Normal Serum, 825. Serum Treatment of Scarlet Fever, 825. Serum Treatment of Acute Anterior Poliomyelitis, 826. Serum Treatment of Pneumonia, 828. Normal Serum Therapy, 829 — Serum treatment of hemorrhage, 829— ^Serum treatment of the toxicoses of pregnancy, 833 — Serum treatment of skin diseases, 834. Autoserum Therapy, 835— Autoserum treatment of skin diseases, 835 — Autoserum treatment of acute infectious diseases, 835 — Autoserum treatment of syphilis (salvarsanized serum), 836 — Autoserum treatment of tuberculosis of serous membranes, 841 — Autoserum treatment of non-tuberculous effusions, 843. Principles of Chemotherapy, 845 — Organotropism and parasitotropism, 845 — Chemoreceptors, 847 — Drug "fastness," 849— Therapia magna sterilisans, 851. Salvarsan and Neosalvarsan in the Treatment of Syphilis, 852 — Historic, 852 — Properties of salvarsan, 854 — Toxicity of .salvarsan, 855 — Properties of neosalvarsan, 856— Methods for preparing salvarsan for administration-, 857 — Methods for preparing neosalvarsan for administration, 857 — Administration of salvarsan and neosalvarsan by intravenous injec^n, 858 — Reactive manifestations, 867 — By intramuscular injection, 875 — By intraspinous injection, 876 — Contraindications and precautions in salvarsan therapy, 878 — Value of salvarsan and neosalvarsan in the treatment of syphilis, 879. Salvarsan in the Treatment of Non-syphilitic Diseases, 880. Chemotherapy in Bacterial Diseases, 881. Chemotherapy in Malignant Diseases, 887. Experiment 1, Production of Agglutinins, .Bacteriolysins and Opsonins, 891 — Experiment 2, Production of Precipitins, 892— Experiment 3, Production of Hemolysins, 892 — Experiment 4, Production of Cytotoxin, 892. Experiment 6, Diphtheria Toxin, 893 — Experiment 7, Method of Testing the Virulence and Toxicity of Diphtheria Bacilli, 894— Experiment 8, Tetanus Toxin (in vivo}, 895 — Experiment 9, Tetanus Toxin (in vitro), 895. EXERCISE 7. — Bacterial Protein. Ptomains. Mechanical Action of Bacteria, 900. Experiment 19, Bacterial Protein, 900 — Experiment 20, Ptomains, 901 — Experiment 21, Mechanical Action of Bacteria, 902. Experiment 22, Phagocytosis in Natural Immunity, 902 — Experiment 23, Natural Antibacterial Immunity, 902 — Experiment 24, Relative Factors in Natural Immunity, 903 — Experiment 25, Influence of Temperature Upon Natural Immunity, 903. Experiment 26, Acquired Active (Antibacterial) Immunity, 903 — Experiment 27, Acquired Passive (Antitoxic) Immunity, 904 — Experiment 28, Acquired Passive (Antitoxic) Immunity, 904 — Experiment 29, Acquired Passive (Antibacterial) Immunity, 904. Experiment 54, Macroscopic Agglutination Reaction, 917 — Experiment 55, Macroscopic Agglutination Reaction (Kolle), 918 — Experiment 56, Macroscopic Agglutination Reaction (Killed Cultures), 918. GENERAL TECHNIC IN this chapter simple methods are described for preparing capillary pipets and similar apparatus usually made in the laboratory, and a few general directions are given concerning the preparation of glassware and other material employed in the various methods described in succeeding chapters and in experimental work. It may be well here to utter a word of caution to the inexperienced against observing undue haste in performing the manipulations of immunologic technic. Careful and painstaking work is essential in order to secure reliable and successful results, and should never be sacrificed for speed, the latter being attained only by experience. CENTRIFUGE 1. A good centrifuge is one of the chief requisites of a laboratory equipment. While any good instrument will answer, preference should be given to the larger types, fitted for holding both 15 c.c. and 50 c.c. centrifuge tubes, propelled by electricity, and mounted on a concrete block in the laboratory (Fig. 1). 2. The machine must be well oiled. 3. The counter tubes should be of the same weight — it is our custom to weigh the tubes on a small balance, and adjust the counter tubes until both are of equal weight. 4. The centrifuge tubes should rest loosely upon a rubber disc or wad of cotton in the bottom of the metal tube or cup; otherwise centrifuge tubes are quite likely to be broken, especially if the machine is run at high speed. If the latter must be sealed, as when working aseptically, rubber stoppers should be used. However, if cotton plugs are large and fit tightly, they may be prevented from becoming displaced by passing through them two cross-pins in such manner that the ends will rest upon the edge of the tube. The plugs are thus prevented from being thrown to the bottom of the tube. PIPETS 19 Tubing having a caliber of 6 mm., with thin walls, that does not become opaque, brittle, or "run" on heating, and that does not contain lead, may be used. The question of alkalinity is also of importance in connection with the tubing. Many of the cheaper grades undergo disintegrative changes, which are accompanied by the setting free of alkali, especially when the glass is heated. Glass of this kind should be discarded, as it may introduce an element of error into our experiments and observations. 2. A convenient length of tubing — about 10 to 12 inches — is chosen; this will make two pipets. If a sufficient length of tubing for both sides is not available, one end may be heated and drawn out with forceps, or a handle may be added by fusing to this short end an odd piece of glass. It is convenient to have on hand a supply of tubes cut to correct lengths, plugged at each end with a ball of cotton, and sterilized in a hot-air sterilizer. They are then ready to be drawn out as needed, thus furnishing sterile pipets with cotton plugs that tend to prevent contamination. 3. The flame must be so regulated as to play upon only so much of the tube as will suffice to furnish the glass required for drawing out the tubing. If a Bunsen flame is used, the tip of the inner greenish flame should be applied. The margins of the flame are the hottest, and for this reason the tube must be shifted from side to side and be constantly rotated. 4. In order to secure uniform heating and satisfactory pipets the tube must be kept constantly rotated from the moment it enters until it leaves the flame. The two ends of the tube are to rest upon the middle finger of each hand while the thumb and forefinger hold the tube in position at either side and impart the rotatory movement. It is also necessary that the tube be displaced laterally from time to time, so as to bring each portion of the middle segment of the tube in turn into the edge of the flame (Fig. 2). If the latter precaution is omitted, we shall obtain a pipet with a central bulb or thicker segment and with thinner segments on each side corresponding to the portions of the tube which lie in the edges or hottest portion of the flame. 5. The tube is heated in this manner until the glass is quite plastic. No attempt is made to draw out the tube until it has been entirely withdrawn from the flame, as otherwise a portion becomes unduly thin and plastic and divides, leaving a small, bent, and very poor pipet in each hand. The rapidity and force with which the tube is drawn out determine the caliber of the capillary stem. By drawing rapidly a tapering capillary tube is obtained; by drawing slowly a larger capillary tube of more uniform caliber is obtained. Of course, the worker cannot take too much time, as the glass hardens quickly. With a little practice this part of the technic is soon mastered. Thorough and uniform heating and careful, steady pulling when the tube is sufficiently plastic are of primary importance. When, owing to an error in judgment in heating the tube, it is withdrawn before it is sufficiently plastic and begins to harden, the situation cannot be remedied by drawing out the tube quickly with a jerk. Similarly, when a tube has been partially drawn and hardens it cannot, as a rule, be reheated and drawn out to make a satisfactory pipet. large portion has been removed from the center. 6. After drawing out the pipets the hands should be held steady for a few seconds, i. e., until the glass has hardened; otherwise the tubes will bend and be less satisfactory. method of Sir A. Wright.1 The essential features of these pipets are: (a) The capillary stem, which serves for measuring and mixing the bacterial emulsion and serum; (6) the portion that serves first as a chamber for the sterile nutrient broth and later as a cultivation chamber for determining whether the microbes that have been mixed with the serum have or have not been killed by it; (c) the glass loop, which acts as a trap, preventing extraneous contamination; and (d) the handle, upon which the rubber teat can be fitted. With a little practice these pipets are readily made. While the glass is still plastic hold the left hand steady, and with the right hand lower the tubing and make a spiral loop in such manner that the loop is closely applied, but does not touch the sides of the upper and lower segments of the tube. Actual contact with the sides must be fore the loop is made. 3. Graduated Pipets. — 1. In this work 1 c.c. pipets graduated into riir c.c. ; 5 and 10 c.c. pipets graduated into yVc.c. will render satisfactory service. The pipets should be calibrated close to the tip, and should preferably be long, with a narrow lumen, rather than short, with a wide lumen, as the latter renders the markings too close to one another. The entire length of these pipets is equal to the ordinary 1 c.c. pipet which renders the subdivisions far apart and quite easy to read (Fig. 4) . These pipets are made by competent dealers upon special request. 2. These pipets should be perfectly clean and clear, sterilized, and have sharp, easily read markings. Pipets with broken tips are difficult to handle, and if calibrated to the tip, are inaccurate. 3. The worker should practise methods of making accurate measurements. The slightest slip may mean an inaccurate measurement and produce untoward results. 4. After pipets have held infectious material they should be placed at once in a jar containing 1 per cent, formalin solution. After pipeting blood, milk, or serum, the pipets should be rinsed or placed in a jar containing water or a weak lysol solution, as the formalin solution tends to harden these substances and renders cleaning quite difficult. They should be washed thoroughly, the mouth end being plugged neatly and firmly with a bit of cotton, and then placed in a metal box or wrapped in newspaper and sterilized in the hot-air oven. Unless all the serum, blood, milk, etc., are well washed out, the pipets may become occluded and discolored. If this occurs, they should be soaked for twenty-four hours in strong nitric (50 per cent.) or sulphuric acid, and washed thoroughly and sterilized. erally used in immunologic work. Note the small cotton plugs in the mouth ends. The 1 c.c. pipet (second from the left) is graduated near to, but does not actually include, the tip; this feature is highly desirable, as it permits measuring small amounts of fluid and the pipet is not necessarily ruined, even though a portion of the tip were chipped off. otherwise the tip may be broken off when the pipets are dropped in. Buck1 has recently devised a multiple pipet capable of delivery into twelve test-tubes simultaneously; this pipet is especially serviceable in conducting large numbers of agglutination and complementfixation tests. BLOOD CAPSULES Blood capsules were devised by Sir A. Wright for collecting small amounts of blood for examination. The essential features of a capsule are: (a) The upper straight limb, which can be drawn out to serve as a needle for puncturing; (6) the recurved limb, which makes it possible to fill the capsule by gravity, without risk of the inflow being arrested by the blood running down and blocking the straight limb, which provides an outlet for the air. 3. Then reinsert the tube into the flame, and, leaving a portion at least 3 cm. in length to serve as the barrel of the capsule, draw out the tube into a capillary stem about 8 cm. in length, and bend it so as to form a stout recurved limb lying in the horizontal plane; now, before the glass has lost its plasticity, draw the capsule gently upward so that its long axis will be at an angle of about 30° horizontally. Finally, separate the capsule from the main tube by filing it across the capillary portion at the distance indicated in the accompanying illustration (Fig. 5). 4. The straight limb may now be drawn to a sharp point and used as a needle. VACCINE BULBS These may be made of glass tubing, to hold 1 c.c. or more, although when a large number are required, it is cheaper to purchase ready-made ampules, such as are shown on p. 219. inserted. 6. The open end is then sealed in the flame by warming the air in the bulb above the surface of the liquid and finally sealing the tip, otherwise the air may expand after heating and cause an explosion at the tip. Care must be exercised not to heat the glass down to the level of the fluid, as this tends to produce steam and to crack the bulb. chosen. 2. The tube is heated at a point near the open end in the Bunsen flame, in the same manner as the glass tubing, i.e., by keeping the tube constantly rotating with a lateral movement to insure uniform heating. 5. The open end may now serve as a funnel for filling the bulb. 6. The bulb is now sealed by warming the air above the level of the fluid and then sealing the tip. With a long stem, in order to secure a portion of the contents, the sealed end may be broken off from time to time; it is readily resealed. 7. Instead of this procedure the fluid may be placed in the testtube at once, the upper end being heated in the usual manner and drawn out; the stem is broken through, and the tip sealed. If the tube is small or the contents are such as will almost fill a tube, this method may not be successful, owing to the production of steam on heating the 1. In this work test-tubes of various sizes are used mainly for making the agglutination, precipitin, complement fixation, and other tests. They should be made of good glass, with round bottoms, and be well annealed. 2. Test-tubes should be thoroughly clean, clear, and sterilized, preferably by dry heat. It is not necessary to plug them with cotton unless they are to be used for bacteriologic work, for when a large number of tubes are used, this is a waste of time and of material. If the tubes are to be used within from twenty-four to forty-eight hours, merely placing the tube mouth end downward in the wire basket is sufficient. A pleted. 3. After a tube has been used for holding living and infectious organisms, as in making bacteriologic, agglutination, and opsonic tests, etc., the tube and its plug should be boiled in water or a 1 per cent, solution of caustic soda before it is again handled. In making hemolytic experiments, the material is not usually infectious, and it is sufficient to wash the tubes without previous boiling. In every case all traces of acids or alkalis must be removed by copious washing in plain water, as the slightest trace of 1 1 either may interfere . with the accuracy of some of the tests. Cheaper grades of glass may contain relatively large amounts of alkali, which would introduce a disturbing element in the reactions. SYRINGES A good syringe is indispensable in performing bacteriologic and immunologic work. Various sizes should be at hand, but usually a graduated 5 c.c. syringe answers most purposes. 1. Many kinds of syringes are on the market. Those with rubber or leather plungers and packings are unsatisfactory, as they cannot be sterilized by boiling and soon leak. Nothing is more exasperating than a leaking syringe, as with the leakage unknown quantities of inoculum are lost, not to mention the possible dangers of contaminating the fingers, the animal, and the laboratory. Syringes with metal or glass plungers are to be preferred, as are also those upon which the needle may be fitted without screwing (Fig. 8) . The old Koch syringe is fitted with a rubber bulb for filling and expelling the fluid. This arrangement is well adapted for making subcutaneous injections, but is somewhat dangerous for purposes of making intravenous injection, on account of the danger of injecting air. SOLUTIONS 27 3. Syringes may be sterilized by filling them with 1 per cent, formalin solution for a few minutes, followed by several washings with sterile water or salt solution. This method is good for syringes having leather or rubber packings and plungers. It is not safe for blood cultures, as spore-forming bacteria may escape the sterilizing process. 4. With all glass or metal syringes, it is best to boil the syringe, especially if a careful aseptic technic is to be employed. The plunger should be removed from the barrel, or else, whether it be of glass or metal, it will expand more rapidly than the accommodation of the barrel will permit. All parts should be placed in a pan or wrapped in gauze, warm water added, and boiling allowed to take place for a minute or so. After cooling the parts are adjusted. ministration of vaccines is given on p. 221. 5. If infectious material has been used, the syringe, after using, should be washed out and sterilized. The needles should be dried and wired, and a small amount of vaselin rubbed over to prevent rusting. The plunger may likewise be occasionally rubbed with a small quantity of vaselin. Needles may be kept in oil or in absolute alcohol; usually thorough drying and wiring preserves them in good condition. 1. Salt Solution. — 0.85 per cent, sodium chlorid in distilled water is best adapted for immunologic work. This solution is prepared readily by dissolving 8.5 grams of salt in a liter of water, filtering, and sterilizing in an Arnold sterilizer for at least one hour. 2. Sodium citrate in 1 or 2 per cent, solution, made with normal salt solution and not with plain or distilled water, is used to prevent the formation of fibrin in drawn blood and exudates. METHODS OF OBTAINING HUMAN AND ANIMAL BLOOD As a general rule, when blood is withdrawn to obtain serum a careful aseptic technic should be employed. Similarly, when erythrocytes are to be obtained for purposes of immunization it is necessary to avoid contamination by proper cleansing of the parts and the use of sterile needles, containers, and solutions. In obtaining erythrocytes for making hemolytic tests it is not necessary that the blood be absolutely sterile, the ordinary precautions against gross contamination being sufficient. test is given on p. 198. Larger quantities of leukocytes are obtained by injecting sterile irritants, such as sterile aleuronat suspension, into the pleural or abdominal cavities of suitable animals. (See p: 204.) (a) Blood may be withdrawn and placed at once in two or three volumes of 1 per cent, sodium citrate in 0.85 per cent, salt solution. Clotting is prevented, and the corpuscles- are secured by centrifugalization or by sedimentation in the refrigerator. (b) Blood may be drawn into a beaker or flask and defibrinated at once by whipping with a rod or shaking with glass beads. When the fibrin has been removed, the corpuscles and serum are secured by centrifugalization. WASHING ERYTHROCYTES be placed in centrifuge tubes and five to ten volumes of sterile normal salt solution added and thoroughly mixed. Tubes are then carefully balanced and centrifuged at moderate speed for five minutes. disturbing the sediment. and centrifuge. This process should be repeated once more in order to insure thorough washing of the corpuscles to remove all traces of serum. For removing supernatant fluids which are to be discarded, the suction pump shown in Fig. 9 will be found very useful. It is well to fit the If serum is desired at once, blood should be drawn into sterile centrifuge tubes and the tube immersed in cold water for from five to ten minutes; this facilitates clotting. The clot is then broken up with a sterile platinum wire or glass rod, and the serum secured by rapid centrifugalization. Or blood may be drawn into sterile cylinders, Petri dishes, or centrifuge tubes, and allowed to stand at room temperature for a few hours, after which they should be placed in a refrigerator until the serum separates. Blood never should be drawn into Erlenmeyer flasks because of the difficulty of drawing off serum without disturbing the clot. When drawn into Petri dishes, care should be taken that the layer of blood is not too thin, otherwise drying will occur with poor separation of the serum. As a rule, the best results are secured by placing blood in centrifuge tubes, for if separation is poor or does not occur at all, the clot may be broken up and serum secured by centrifugalization. So far as possible, avoid drawing blood from an animal immediately after feeding, as under these circumstances the serum is likely to be milky or opalescent. at once in cold centrifuge tubes. 1. After warming a centrifuge tube immerse in hot molten paraffin. Remove, drain, and allow the paraffin to harden. This produces a thin coat of paraffin within the tube; if a thicker one is desired, immerse again until a coat of the desired thickness is obtained; chill the tube thoroughly in cracked ice, but avoid getting water inside the tube. The patient's finger is grasped firmly and lanced with a Daland lancet across the folds of skin. When lanced parallel with the skin-folds, the wound is likely to close before sufficient blood is secured. 3. Centrifuge at once and at high speed. If this is not possible, pack the tube in a large centrifuge cup, and surround with finely cracked ice. This permits of more prolonged centrifugalization, and at lower speed, and yields a hemoglobin-free plasma. OBTAINING SMALL AMOUNTS OF HUMAN BLOOD For obtaining small amounts of blood — up to 2 or 3 c.c. — for the Widal reaction, complement fixation, and other tests, the following method is satisfactory: 1. Wash the last joint of the middle finger with alcohol. If the hand is cold, it should be warmed by immersing it in hot water. Before puncturing compress the finger and squeeze in such a manner as to drive the blood toward the end of the finger. FIG. 11. — METHOD OF SECURING A SMALL AMOUNT OF HUMAN BLOOD. By pricking the finger deeply across the lines of the skin with a broad lancet, two or more cubic centimeters of blood are easily collected in a small test-tube. Do not use a large tube, as blood may be lost on the sides of the tube. 3. Collect the blood in a small test-tube, — about 8 cm. by 1 cm., — such as is used in performing the Noguchi reaction for the serum diagnosis of syphilis (Fig. 11). 4. By squeezing the finger, sufficient blood can usually be obtained from one puncture practically to fill a tube of the size mentioned. One to two cubic centimeters of serum are easily obtained in this manner, and this is sufficient for cond acting the ordinary serum reactions. When OBTAINING LARGE AMOUNTS OF HUMAN BLOOD the treatment of syphilis is being guided by the Wassermann reaction, frequent tests are necessary, and a patient may object to submitting to repeated venipuncture. The method for securing blood just described is so simple and efficient that objections to it are never made. 5. Blood may also be drawn in a Wright capsule, made by drawing out ordinary thin glass tubing in the Bunsen burner. (See p. 23.) After sufficient blood has been collected (Fig. 12), the straight empty end is sealed with a flame and then cooled (Fig. 14) . The blood is then shaken into this sealed end, and the bent end, in turn, sealed with the flame. Care should be OBTAINING LARGE AMOUNTS OF HUMAN BLOOD Larger quantities of human blood may be required for making complement fixation reactions, the Abderhalden ferment test, etc. (a) Phlebotomy. — 1. In adults, a prominent vein at the elbow, such as the median basilic, is usually chosen. In children less than a year old this vein is not suitable, better results being obtained when the external jugular or a temporal vein is used. 4. Steady the skin over the vein, and insert the needle in the direction of the blood-current (Fig. 15). It is more awkward, and of no practical advantage, to puncture in a downward direction toward the hand. The needle should be sharp, and of a size midway between the ordinary hypodermic and a large antitoxin needle, as the former is too small and the latter is unnecessarily large. The blood is then allowed to drop into a sterile tube. It is not necessary to attach ING A WRIGHT CAPSULE. a syringe, although 5 to 10 c.c. of blood are obtained more quickly by this means on account of the possible gentle suction. Needle and syringe should be 'sterilized by boiling. When larger quantities of human serum are required as in auto-serum therapy, a platinumiridium needle should be used, as coagulation in the needle is less likely to occur; besides, these needles are readily sterilized by heating in the flame. wound with a touch of flexible collodion. FIG. 15. — METHODS FOR SECURING BLOOD BY PUNCTURE OF A VEIN. The middle figure shows distention of the veins of the arm about the elbow. The needle is entered by a quick upward thrust. Practically any prominent and firm vein may be used. The upper right-hand figure shows collection of blood in a testtube. Usually 10 c.c. or more are easily collected before clotting occurs. To secure large amounts, use a larger needle with a smooth bore (preferably a platinum-iridium needle). The lower right-hand figure shows collection of blood in a Keidel tube. 5 c.c. ampule with arm drawn out to a capillary tip and sealed after a vacuum has been created by heating (Fig. 16a, B). A short piece of rubber tubing connects the needle and the capillary portion of the ampule. A needle of No. 25 gage is fitted tightly into the free end of the rubber tubing. A slender glass tube closed at one end and flaring slightly at the other serves as a protection for the needle, which it covers when the apparatus is sterilized. The apparatus is sterilized in a hot-air oven at 150° C. for one hour. To obtain a specimen of blood the needle is inserted into a vein, and the capillary end of the ampule crushed with a hemostat through the rubber tubing, blood flowing into the ampule and replacing the vacuum. The protecting glass tubing is then replaced. Not infrequently, especially in children and in obese adults, one fails to enter a vein. Several attempts to do so may result in ruining one or more of the tubes. My colleague, Dr. Alfred Reginald Allen, has devised a useful modification in the technic of using this handy tube; this consisting in detaching the bulb from the rubber tubing and needle, inserting the latter into the vein, and, when the blood appears, quickly attaching the bulb and breaking the neck with a hemostat, in the usual manner. By this method the bulb is not broken until one is sure he has entered a vein and secured a specimen of blood. or with a special scarifier. 4. Apply a cup and exhaust the air with special syringe. The vacuum produces marked congestion of the skin with a ready flow of blood. be obtained by collecting placental blood. 1. After tying and cutting the cord, the placental end is placed carefully in a 150 c.c. flask or bottle containing from 25 to 50 c.c. of sterile 2 per cent, sodium citrate in physiologic salt solution. To avoid contamination, the cord may be lightly 2. By exerting pressure on the uterus blood may be squeezed out of the placenta. The flask is then sealed with a sterile cotton plug and gently shaken. The chief purpose in making spinal puncture is to obtain and examine cerebrospinal fluid as an aid to the diagnosis of cerebrospinal diseases. It is mainly of value in neurologic and psychiatric practice, for the purpose of securing fluid for making the Wassermann reaction, for a study of cytologic changes, alterations in protein content, and the like. Not infrequently the procedure is required as an aid to establishing a diagnosis of meningeal diseases in children, particularly tuberculous meningitis, epidemic cerebrospinal meningitis, meningeal irritation, gitis," etc. Contraindications. — Ordinarily, when skilfully performed, spinal puncture is a harmless procedure. Unless the necessity for obtaining fluid is very urgent, the operation should not be done on persons in poor FIG. 16a. — PARTS OF THE KEIDELTTTBE. E is the vacuum bulb which is attached to the needle by a piece of rubber tubing (D); the glass tube (E) covers the needle and the whole is sterilized. physical condition. Kaplan has cautioned against making lumbar puncture in the presence of tumors of the posterior fossa, particularly of the cerebellum. When it is highly desirable to study the fluid of such cases, 2 c.c. may be withdrawn, and immediately replaced with sterile normal salt solution, or if no immediate effects are observed, the patient may be kept in bed for the next twenty-four hours. The cup is held in this position over a scarified area; air is exhausted by means of a pump attached to the rubber tubing; blood collects in the small test-tube. (Made by Hynson, Westcott & Dunning, Baltimore, Md.) night. The ordinary preparations consist in scrubbing the skin of the lumbar region with green soap and hot water, using gauze sponges, followed by washing with alcohol and ether. The area is then covered with sterile gauze, and, just before the puncture is made, an application of 10 per cent, tincture of iodin is made; or the preliminary cleansing may be METHOD OF SECURING CEREBROSPINAL FLUID 39 omitted, two or three coats of the iodin . being sufficient. After the fluid has been secured, the iodin may be removed with alcohol and gauze. The operator's hands should be cleansed carefully and washed in alcohol and bichlorid solution or weak formalin, or he may put on sterilized rubber gloves before handling the needle and performing the operation itself. Anesthesia. — In the majority of instances an anesthetic is not necessary. In tabes dorsalis and general paralysis (two conditions most frequently requiring spinal puncture) the operation is peculiarly painless. Sick children are apparently not greatly disturbed, but in adults it may be necessary to infiltrate the skin about the site of puncture with 1 per cent, eucain (sterile) or cocain solution. Ethyl chlorid is much less satisfactory, except for the mental effect it has upon the patient. Children may receive a few drops of ether. With nervous patients it is good practice to obviate nervous shock by adopting a few simple precautions against causing unnecessary pain. Technic of Lumbar Puncture. — The patient may either sit in a chair and bend forward, or lie on the left side on the edge of a bed or table. In the case of sick persons, particularly children, the latter position is necessary; it is also advisable with nervous patients, as they are likely to bend backward suddenly or jump up when the needle is inserted, and I have known the needle to be broken off at such a time. (See p. 752.) The back should be arched backward, the patient bending forward, and the knees being drawn up over the abdomen. The needle should be made of flexible, not rigid, material; for adults, a needle 10 cm. long, having a bore of 1 to 1.5 mm. and furnished with a stilet, will be found satisfactory. For children, a shorter needle may be used, but the bore should be about the same as that used for adults. The needle should be sterilized carefully by boiling in water for several minutes. The operator now selects a "soft spot" for puncture. By running the finger along the spines of the vertebrae, this will be found to be between the third and fourth lumbar spinous processes, about on a level with the posterior superior spines of the ilia. The needle is grasped firmly and inserted with a sudden thrust, exactly in the median line, and straight forward. The thrust should be sufficient to push the needle through the skin and muscles into the spinous ligaments; it may then be inserted more slowly, a sudden "give way" indicating that the canal has been entered (Fig. 18). This route is better than the lateral route, as there is less danger of striking vertebral processes or other obstructions. The stilet is now withdrawn. Usually the first fluid to appear is stained with blood and should be collected in a separate tube. From 5 to 10 c.c. of fluid are then collected in a second sterile tube, the needle is quickly withdrawn, and the puncture wound sealed with collodion and cotton or with adhesive plaster. The patient is sitting on the edge of a chair and is bent forward; the crests of the ilia are indicated by black lines, and are on a level with the spinous process of the fourth lumbar vertebra; the "soft spot" is found just above. The needle is shown in Figs. 141 and 142. The first tube receives the first few drops of fluid, which are usually blood tinged. breath, and if fluid does not appear now, the stilet may be inserted gently to dislodge any material that may be occluding the needle, or the needle may be withdrawn a trifle if it has been inserted too far, or may be advanced a little if it has not entered the canal. If, however, the tap proves a dry one, or if only a few drops of blood are obtained, it is not advisable to make another puncture, as the second attempt is likely to prove as unsuccessful as the first. After-treatment of the Patient. — Occasionally the needle may strike a nerve filament, which occurrence is followed by more or less pain along the course of its distribution; puncture of the bone is likely to be followed by pain for several hours. The majority of patients are so little affected by lumbar puncture that no precautions as regards the aftertreatment are necessary. As previously stated, it is advisable for the patient to rest overnight. Sudden release of pressure or the nervous shock may give rise to severe headache of one or of several days' duration; persons of hysteric temperament may, in addition, suffer from diarrhea and vomiting. Rest in bed, the application of ice-bags, and the administration of sedatives are usually sufficient to relieve these after effects. Disposal of the Fluid. — As a general rule, the fluid should be sent at once to a laboratory, as total cell counts and bacteriologic cultures are best made with fresh fluid. For the Wassermann reaction it is not advisable or necessary to add a preservative, as the fluid will keep for several days in a good refrigerator; if, however, the fluid is to be kept for longer periods of time, 0.1 c.c. of a 1 per cent, solution of phenol may be added to each cubic centimeter of fluid. OBTAINING SMALL AMOUNTS OF ANIMAL BLOOD Rabbit. — 1. Flip an ear vigorously with the hand, and rub with xylol and alcohol. The xylol produces marked congestion and afterward should be carefully removed with alcohol and water, as it produces a low-grade inflammatory reaction. 2. Puncture a marginal vein with a large needle. The blood will flow quickly in drops and practically any amount up to 10 c.c. or even more may be collected in a centrifuge or test-tube (Fig. 19). For making preliminary tests of serum during immunization 2 c.c. of blood is usually sufficient. Bleeding may be checked by making firm pressure over the puncture. Guinea-pig. — 1. Blood may readily be removed directly from the heart by anesthetizing the animal with ether, and inserting a sterile needle into the heart at the point of maximum pulsation. A syringe for aspiration may be attached, but better results are secured by adjusting a suction apparatus. By means of a short piece of rubber tubing the needle may be connected to a test-tube so arranged that a partial vacuum is created by attaching to a water suction pump. As soon as the heart has been entered, blood is seen to flow into the tube injection of a gram of chloral hydrate in 10 c.c. of water, deep sleep being induced by the latter in from five to ten minutes, and lasting for several hours, during which time operative procedures produce no pain. First Method (Nuttall). — The animal is fastened to an operating board, or, preferably, held by an assistant, and the hair over the neck and thorax is moistened with a 1 per cent, lysol solution. By means of a sterile knife the skin is cut longitudinally and the neck muscles exposed for a considerable distance. The animal is then held upright by the assistant over a sterile dish or a large sterile funnel, emptying into a cylinder or 50 c.c. centrifuge tube. The operator stretches the neck by carrying the head backward, and severs the large vessels on one or both sides of the neck with a sharp sterile scalpel or razor, avoiding opening the trachea and esophagus. After bleeding, the dish is covered or the tube plugged and set aside for the serum to separate. This method is quite simple, may be employed by the inexperienced, and usually yields a large amount of sterile serum. Second Method. — The animal is fastened to the operating board and the neck is stretched by placing a roller beneath it. The hair over the neck is clipped close, and the skin moistened with alcohol and 1 per SECOND METHOD. cent, lysol solution. The carotid artery of one side is exposed by making a straight incision through the skin over the trachea and skinning well to one side, exposing the sternohyoid muscles and external jugular vein. The carotid artery, internal jugular vein, and pneumogastric nerve are to be found at the outer border of the sternohyoid muscles (Fig. 20). By means of blunt dissection the artery is exposed and carefully isolated. Two small spring clamps or hemostats are then applied close together at the distal end, and the artery divided between them. The proximal end is then held with forceps within the mouth of a sterile cylinder or large centrifuge tube. The wall of the artery is incised with fine scissors proximal to the forceps, and the blood is allowed to flow into the vessel. The yield of blood may be increased somewhat by exerting pressure on the animal's abdomen and thorax. THIRD METHOD. sterilized in the autoclav before using. After the artery has been exposed and isolated, a temporary clamp is applied to the proximal end. A small incision is made in the wall of the artery, and the cannula inserted and fastened with a ligature. The clamp is then removed, and blood collected in a large tube. Third Method.— The following method, employed at the Pasteur Institute at Paris, has been found very useful. The animal — a rabbit or a guinea-pig — is anesthetized, and secured to an operating-table. The carotid artery is carefully and aseptically exposed, and separated The bottom of a large sterile test-tube is heated and drawn out to a fine point, as shown in the illustration (Fig. 22), and the tip is broken off. The operator now places his moistened forefinger under the artery, elevating it up and rendering it taut ; the tip of the tube is then passed through the wall into the interior of the vessel toward the heart. The moment the vessel is entered the blood-pressure drives the blood into the tube, so that 20 c.c. are soon secured. An assistant now ties the ligature below the site of puncture; the tube is withdrawn, and the tip sealed in a flame. The ends of the ligatures are cut short and the wound is stitched. Healing usually occurs at once, and if subsequent study of the blood is required, the other carotid and the femorals can be used similarly for securing it. Fourth Method. — The animal is fastened to the operating board, and the hair over the neck and thorax moistened with alcohol or lysol solution. The right thorax is then incised and held open by an assistant. The right lung is seized with sterile forceps and quickly severed at the base with sterile scalpel or scissors. The heart is then punctured, and the blood is quickly removed from the thoracic cavity with a sterile 25 c.c. pipet with a large opening. Unless the lung is removed, it tends to float and block the end of the pipet. Everything must be in readiness, as otherwise blood will be lost, flooding the thoracic cavity. Guinea-pig. — Pig serum is usually secured to furnish complement in hemolytic tests, and should be used within twenty-four or forty-eight hours after bleeding. Precautions to insure sterility are not, therefore, usually necessary. 1. The animal is anesthetized with ether and the large vessels of the neck on one side are exposed by a longitudinal incision. These are severed, and the blood is collected in a Petri dish or in a centrifuge tube by means of a funnel (Fig. 23). 2. By means of a sharp-pointed scissors the vessels on one or both sides of the neck may be incised transversely at one cut, inserting the blade deeply and close to, but avoiding, the trachea and esophagus. Rats. — 1. Small quantities of blood may be obtained by snipping off the tip of the tail of the animal and milking blood into an appropriate sterilized tube containing glass beads, or 2 per cent, sodium citrate solution. In this manner one or more cubic centimeters of blood are easily obtained, and at once defibrinated and injected into the peritoneal cavities of other animals, as in inoculating trypanosomes, etc. Sheep. — Blood may easily be obtained from a freshly killed animal. The first flow of blood is discarded, and a portion of the remainder is collected in a large, sterile, thick-walled flask containing glass beads THE EXTERNAL JUGULAR VEIN. T, trachea; O.M., omo-hyoid muscle; E.J.V., external jugular vein^ S.C.M., sterno-cleido-mastoid muscle. This dissection was made soon after natural death and shows the position and size of the vein with the head held backward as it is when blood is removed according to the technic described in the text. When distended, the vein is even larger than shown; it is quite superficial and is usually palpable when pressure is made over the vein at the base of the neck. by whipping with glass rods. It is usual, however, in large laboratories, to keep a sheep and remove the blood as it may be required. Small amounts may be obtained from the ear vein, larger quantities being secured from an external jugular vein in the following manner: The operator is distending the vein by pressure over the base of the neck with the left hand. When distended, the vein can usually be felt beneath the skin. The needle here shown is reduced to a little more than half the actual size. sors and alcohol applied. 5. The operator then grasps the neck low down with the left hand, and by means of the thumb exerts pressure over the base of the neck. The external jugular vein will be found in a groove between the omohyoid and sternomastoid muscles (Fig. 24). Firm pressure over the base of the neck usually distends the vein, which may be seen or easily felt. After locating the vein, the pressure should be released for an instant, when the distention will disappear. In this way the operator may be more certain that he has located the vein. 6. A sterile stout needle, at least two inches in length and provided with a trocar and special shank for firm grasping, is passed quickly into the distended vein in an upward and inward direction (Fig. 25). It is essential that the needle be sharp, otherwise it will be turned aside by the wall of the vein. The end of the needle must not have too long a bevel, or the point will pierce the opposite wall before the body of the needle is well within the vein. The trocar is now removed, and blood collected in a flask or bottle and defibrinated with glass beads and rods. A short piece of rubber tubing may be attached to the needle. A suction apparatus is not needed because the flow of blood is good so long as pressure is preserved over the vein at the base of the neck. 7. When the required amount of blood has been secured, pressure is released and the needle quickly withdrawn. Bleeding ceases at once, and the neck is then washed with alcohol. 8. By this method the same vein may be used over and over again for several .years. I have never known infection to occur, although the gradual formation of scar tissue about the site of puncture may interfere with the operation. Hog. — Blood may be secured from hogs by clipping off a small portion of the tail with a sharp razor or scissors, beginning at the tip. Bleeding is usually quite free, but is easily controlled by a tourniquet and bandage. The serum of hogs immunized against hog cholera is secured in this manner. Monkey. — 1. Small quantities of blood — up to 10 or 20 c.c. — may readily be obtained from a small vein just beneath the skin which crosses over the inner malleolus at the ankle. When a tourniquet is applied, the vein becomes prominent; the hair is clipped, and tincture of iodin applied over the skin; a small needle is passed into the vein, and the blood collected in a centrifuge tube. Dog. — 1. Small quantities of blood may be obtained in the following manner: Apply a tourniquet just above the knee; clip the hair over the anterior surface of the leg, and cleanse with tincture of iodin and alcohol; make a small incision in the long axis, exactly in the median line; a fairly large vein appears at once just beneath the skin; by inserting an appropriately sized needle, several cubic centimeters of blood are quickly and easily secured. The wound should be very small, and usually requires no treatment other than an application of collodion and cotton. 2. Large quantities of blood are obtained from the external jugular vein with or without ether anesthesia; the neck is shaved and cleansed; the skin is incised over the vein, which is just beneath the skin, and blood removed with a sterile needle and syringe. Pressure over the base of the neck renders the vein more prominent. In the case of large dogs, incision is not necessary, as it is easy to enter the vein directly through the skin, as in bleeding the sheep from the external jugular vein or the human from a vein at the elbow. Blood may also be secured from the femoral vein under ether anesthesia. Horse. — 1. Small quantities of blood for making agglutination and complement fixation tests may readily be secured from a superficial vein about the leg. The hair is clipped over the selected area, and the skin sterilized with tincture of iodin. A tourniquet is applied to render the vein prominent, the vessel is steadied between forefinger and thumb, and a needle quickly inserted. 2. Larger quantities of blood are secured from the external jugular vein. This operation is easily conducted in an aseptic manner and blood collected in sterile jars. The neck about the region of the vein, usually on the left side, is clipped, and a large area washed with hot lysol solution. A sterile sheet may be thrown about the shoulders. The animal is held or placed in specially constructed stalls that prevent him from backing away or causing mischief. In large antitoxin laboratories bleeding is conducted in special rooms, where a careful aseptic operating-room technic may be observed. The external jugular vein is rendered prominent by exerting pressure at the base of the neck by the application of a special tourniquet or by the thumb and fingers of the left hand, the thumb being placed just above the vein. A small incision is made through the skin, directly above the vessel. TECHNIC OF ANIMAL INOCULATION THIS is a highly important part of immunologic work, as both for serum diagnosis and for serum therapy the serum must be secured from animals that have been artificially immunized. Successful inoculation requires unremitting care and thoroughness, as the toxic effects of the proteins in general may kill an animal before immunization has been completed. No hard and fast rules can be laid down — the weight cf an animal and the reaction to an injection should decide the frequency and the size of Subsequent injections. It is better to proceed slowly and gradually, than to give too large a dose at once and at too frequent intervals. GENERAL RULES 1. Select an appropriately sized syringe that does not leak upon being tested with water. As has been stated elsewhere, nothing is more unsatisfactory than a leaking syringe, for not only may the hand become soiled, but an unknown quantity of inoculum is lost. 2. The inoculum should be sterile. This is especially desirable when giving intravenous and intraperitoneal injections. When living cultures of bacteria are to be injected, the syringe and the needle should be sterilized in order to avoid the introduction of contaminating organisms. 3. Remove the plunger from the barrel, and sterilize all the parts by boiling for at least one minute. As previously staged, an all-glass syringe or a glass barrel and metal plunger is the most satisfactory. (See Fig. 8.) The old-fashioned syringe with washers and rubbertipped plunger should find no place in a laboratory. 4. After cooling, expel the water and load the syringe. This may be done by drawing the fluid directly into the syringe and measuring the dose by its markings or by pipeting the exact dose into a sterile Petri dish or capsule and drawing up in the syringe. 5. The animal should be fastened or held firmly and in an easy position. Everything should be in readiness, so that the injections may be given thoroughly and carefully. 6. In preparing the inoculum care should be exercised that no solid particles enter the syringe. Aside from possibly blocking the needle and interfering with the injection, the subcutaneous injection of small fragments may do no particular harm, but in intravenous inoculation they may cause fatal embolism. To obviate this danger the inoculum should, if possible, be filtered through sterile filter-paper before the syringe is filled. 7. Air-bubbles should be removed. The injection of small bubbles of air into subcutaneous tissues may cause no harm, but when injected into veins they may cause serious disturbances or immediate death. To avoid this the syringe, after being filled, should be held vertically, with the needle uppermost. The needle should be wrapped in cotton soaked in alcohol, and the piston of the syringe pressed upward until all the air is expelled from the barrel and the needle. If a drop of inoculum is forced out, it will be collected on the cotton, which should immediately be burned. 8. Injections should be given slowly. 9. The animal is then tagged or marked, or its coloring recorded. In the case of rabbits, the metal ear tag is best. All data, e. g., the date, size of dose, preparation and kind of inoculum, etc., should be recorded in writing. 10. When it is necessary to incise the skin in order to reach a vein an anesthetic may be given. With superficial veins, and in subcutaneous inoculations, the injections may be given so readily and easily that no more pain can be felt than that which accompanies similar injections in human beings. Animals may be actively immunized in a variety of ways and in different locations in the anifnal body. For a particular antibody, a certain method may be found especially efficacious, and this is dealt with in a subsequent chapter. In serologic work immunization may be performed by subcutaneous, intramuscular, intravenous, intracardial, and intraperitoneal injections. 4. Pinch up a fold of skin between the forefinger and the thumb of the left hand; hold the syringe in the right hand, and insert the needle into the ridge of skin between the finger and thumb, and push it steadily onward until the needle has been inserted about an inch (Fig. 27). Care must be exercised not to enter the peritoneal cavity. Relax the FIG. 27. — SUBCUTANEOUS INOCULATION OF A GUINEA-PIG. A fold of skin is pinched up and the needle entered into the fold. The skin is then released, and the injection slowly given. A swelling indicates that the injection is subcutaneous. grasp of the left hand and slowly inject the fluid. If the skin is raised, this shows that the injection is subcutaneous. If it is not, the needle should be slightly withdrawn and inserted. 5. Withdraw the needle, and at the same time cover the puncture with a wad of cotton wet with alcohol. A touch of flexible collodion over the puncture completes the operation. 6. By means of a fine-pointed forceps or a glass tube syringe introduce the inoculum into this pocket and deposit it as far as possible from the point of entrance of the instrument. and slowly inject the fluid. METHOD OF MAKING INTRAVENOUS INOCULATION Rabbit. — 1. The posterior auricular vein along the outer margin of the ear is better adapted than a median vein for this purpose. 2. If a number of injections are to be made, commence as near the tip of the ear as possible, as the vein may become occluded with thrombi, and subsequent inoculations may then be given nearer and nearer the root of the ear. 3. The animal should be held firmly, as the slightest movement may result in piercing the vein through and through and require reinsertion of the needle. This is accomplished satisfactorily by placing the rabbit upon the edge of the table and holding it firmly there by grasping the neck and front quarters, the assistant at the same time compressing the root of the ear with the thumb and forefinger. 6. The ear is grasped at its tip and stretched toward the operator, or the vein may be steadied by rolling the ear gently over the left index-finger and holding it between the finger and thumb. METHOD OF MAKING INTRAVENOUS INOCULATION 57 7. The inoculum should be free from solid particles, and all the air excluded from the syringe. As a general rule, the amount injected should be as small as possible, and the. temperature of the inoculum be near that of the body. If the syringe is filled shortly after sterilization, when it has cooled enough to be comfortably hot to the touch the heat will warm the injection fluid and not be hot enough to cause coagulation. occurs, the injection must cease and another attempt be made. 10. The needle is quickly withdrawn, a small piece of cotton moistened with alcohol placed upon the puncture wound, and firm compression applied. Wash the ear thoroughly with alcohol and water to remove xylol, otherwise a low-grade inflammation which will render subsequent injections more difficult will follow. 6. Pick up the skin just above and in the middle of the space between the shoulder and the tip of the upper end of the sternum — just above and about in the center of the area where a clavicle in the human would be situated. With sharp small scissors incise the skin for about one-third of an inch. Separate the subcutaneous tissue gently with forceps; a large vein at once comes in view (Fig. 29). Gently dissect it free for about one-fourth of an inch. The vein is steadied by a pair of fine forceps and the injection given through a small needle. The incision here shown is larger than actually required in practice; the vein is also smaller than normal, as the animal was dead for a few hours prior to making the illustration. 8. Withdraw the needle and apply firm pressure with a wad of clean gauze or cotton. It is not necessary to tie off the vein. A stitch may be inserted to close the skin wound and flexible collodion applied. Mice and Rats. — 1. Mice and rats may be injected through a caudal vein of the tail. These veins are quite small, and the injection requires a fine needle and some experience in the manipulations. 5. Rats may also be injected through the external jugular vein, in exactly the same manner as a guinea-pig is inoculated. (See Fig. 30.) The animal is fastened to a small operating board, and an assistant holds the head to the left, which stretches the tissues of the right shoulder and side of the neck. A small incision is made midway between the middle line of the neck and the tip of the fore-shoulder. With superficial dissection a prominent vein appears; this vein is picked up with fine forceps and the injection is readily given through a fine needle. The operator causes the vein to distend and become prominent by pressure with the left hand. The needle is entered beneath the skin and is pushed upward for an inch or more before the vein is entered. When withdrawn, this tunneled passage closes and prevents bleeding. Larger injections may be given in the same manner by gravity. 6. After the injection has been given, either with a syringe or, when the inoculum is large in amount by gravity from a large jar, the needle is quickly withdrawn. Bleeding ceases as soon as pressure over the vein is removed. . Sheep and Goats. — In sheep and goats the intravenous injection is given into the external jugular vein, directly through the skin. The hair is clipped, and the part shaved and disinfected. Compression by the finger at the root of the neck renders the vein more prominent. Injections are also readily given through a popliteal or a femoral vein. If necessary, a small incision may be made through the skin in order to expose the vein chosen for the injection. 2. There is a small vein just beneath the skin, in the median line, along the anterior surface of the leg, which is readily accessible. Clip away the hair, and disinfect with iodin and alcohol. Direct the assistant to grasp the thigh just above the knee, to distend the vein and prevent movement, and make a small incision directly in the median line. A small vein is seen at once. Dissect free or pick up gently with fine forceps and insert a small sharp needle. The injection can thus be readily given. Withdraw the needle, apply firm pressure, and insert a single stitch. Bind the wound with a few turns of a gauze bandage or seal with collodion and cotton. 1. Guinea-pigs may be injected by the intracardial route instead of intravenously. The technic is not, as a rule, more difficult, and no ill effects are noticed. Not infrequently, however, attempts to inject in the heart fail, and frequent trials are not permissible on account of the danger of injuring the organ. 3. Determine the point of maximum pulsation to the left of the sternum by palpation, and quickly insert a thin, sharp needle at the selected area. A flow of blood indicates that the needle has entered the heart. Attach the previously filled syringe and slowly in j ect the contents . 4. Detach the syringe in order to make sure that the injection was intracardial, as intended, which is indicated by a flow of blood; then quickly withdraw the needle. The puncture wound may be sealed with collodion. FIG. 33. — METHOD OF PERFORMING INTRAPERITONEAL INOCULATION OF A RABBIT. The head is held downward; the intestines gravitate toward the diaphragm (note distention); this leaves an area between the umbilicus and pelvis relatively free of intestines and lessens the danger of puncturing the intestines. METHOD OF MAKING INTRAPERITONEAL INOCULATION Rabbit. — 1. Clip the hair and shave an area about two inches in diameter in the median abdominal line, just below the umbilicus. Apply 2 per cent, iodin in alcohol. 2. Direct an assistant to hold the animal firmly, head down. With the animal in this position the loops of intestine tend to sink toward the diaphragm, leaving an area above the bladder which is sometimes free of intestines (Fig. 33). 3. The syringe is grasped firmly, and the needle inserted beneath the skin for a short distance, in the direction of the head in the long axis of the animal when the hand is raised and the needle forced forward through the peritoneum. When the peritoneum has been entered, this is evidenced by a relaxation of the abdominal muscles. The needle is then withdrawn slightly and the injection made. Guinea-pig. — 1. Direct an assistant to hold the animal firmly upon its back. This is better than fastening it to an operating-table, for it permits relaxation of the abdominal wall when the injection is to be made. 2. Clip the hair close to the skin in the median abdominal line. A small area may be shaved although this is not necessary. Disinfect with an application of iodin in alcohol. 3. With the left forefinger and thumb pinch up the entire thickness of the abdominal parietes in a triangular fold, and slip the peritoneal surfaces over each other to ascertain that no coils of intestine are included. the fold near its base. 5. Release the fold and inject the fluid. If a swelling forms, this shows that the needle is in the subcutaneous tissues, and another attempt should be made to enter the peritoneum. 6. It may be difficult to pinch up the parietes without including the intestine. In such case straighten out the animal and stretch the skin between the left forefinger and thumb. Insert the needle obliquely until it is beneath the skin. A slight thrust suffices to pierce the peritoneum, when the abdominal muscles will be felt to relax. Withdraw the needle slightly and inject the fluid. ANIMALS IN overcoming an infection, acquired either naturally or artificially, the macroorganism develops antibodies, or protective substances, against the infecting agent. Possessed of these antibodies, the animal can subsequently withstand a more severe attack of the same infection. Thus, the body-cells of the animal itself are actively concerned in producing these antibodies, and the resulting protection or immunity is therefore called "active immunity." The general term "antigen" has been applied to ^nyjjubstance, that can stimulate the formation of an antibody. The immunity following scarlet fever is an example of active acquired immunity, although the antigen is unknown. In order to acquire immunity it is not always necessary for a person to have had the disease. Thus, a severe infection with the antigen of typhoid fever — Bacillus typhosus — results in a general reaction, exhibiting symptoms and course known clinically as typhoid or enteric fever; whereas, if the antigen is attenuated and injected artificially in small doses in the form of a vaccine, the body-cells react, producing antibodies and a resulting immunity against typhoid fever, without discomfort or danger to life. This process is known as vaccination, the term being first applied to a similar procedure employed in inducing an immunity against smallpox by the inoculation of a small dose of the antigen attenuated or modified by passage through the cow (cow-pox virus) . This process of stimulating the body-cells to produce antibodies is called active immunization, and, while the immunity following disease is an example, the term is generally applied to artificial immunization, as in vaccination, which serves in medicine, therefore, the primary purpose of effecting prophylaxis. In laboratories active immunization of animals is generally undertaken with a view to obtaining serums to be used for diagnostic or therapeutic purposes. Practically, any protein may serve as an antigen. Thus, animals may be immunized not only with various bacteria, but with serum albumins and globulins, milk, egg-albumen, epithelial cells, etc. It must 5 65 66 METHODS FOR EFFECTING ACTIVE IMMUNIZATION OF ANIMALS be remembered that these substances — the antigens — are toxic, and that the process of immunization may evoke a marked disturbance in the general health of the animal. Special attention should be given to feeding and the general care of the animal, the temperature, weight, the presence of diarrhea, and the occurrence of abscesses, edema, paralysis, etc. If the animal dies, a careful postmortem and bacteriologic examination should be made, in order to study the changes produced by the inoculated antigen, and to ascertain if death was induced by the antigen or by contamination and secondary infection. In the manufacture of serums on a large scale, especially for therapeutic use, horses are used almost exclusively. For diagnostic purposes and especially in the study of immunity, smaller animals, such as rabbits, guinea-pigs, white mice, and rats, and occasionally goats or sheep, are employed. So far as their power of producing antibodies is concerned, there are individual differences among the same species of animals; thus, horses immunized against diphtheria differ in the quantity of antitoxin produced. Similar differences are observed in the smaller animals. Immunization with a single antigen usually produces several different antibodies, although for diagnostic or therapeutic purposes one usually predominates. Thus immunization of a rabbit with dead typhoid bacilli produces agglutinin, opsonin, bacteriolysin, and complement-fixing bodies, although the agglutinin is probably the most prominent and is used in diagnosis. Immunization with the diphtheria bacillus and its toxin leads to the formation of an antitoxin, opsonin, and complement-fixing body, although antitoxin is by far the most prominent and is used therapeutically. We give here methods for making various immune serums from small animals, to be used for the purpose of study and for aiding diagnosis. Curative serums, such as diphtheria and tetanus antitoxin, antimeningococcus serum, etc., are made on a larger scale by immunizing horses. 1. The antigens are usually injected subcutaneously, intramuscularly, intraperitoneally, or intravenously. As a rule, the sooner the antigen comes in relation with the body-cells, the more rapid is the immunity gained, and for this reason the intravenous and intraperitoneal routes are frequently chosen. 2. No fixed rules as to the amount to be injected can be given. Experience may show a general method to be the most successful, but as previously mentioned, the general condition and reaction of the animal will be the main guide as to the amount and frequency of the injections. Severe reactions may yield unsuccessful results, and doses so small as apparently to give no reaction may lead to a high-grade immunity. lowing way: (a) A small dose of antigen is injected. If a reaction sets in, wait until this has subsided, and then, after the fifth day, make a second injection of a somewhat larger dose. After another interval of from five to seven days a third injection of a still larger dosage is administered, and so on for two or more injections. pecially useful when a serum is needed as soon as possible. 4. It must be emphasized that good results are largely dependent on the care with which the animals are injected. The operator should work as aseptically as possible, especially when giving intraperitoneal and intravenous injections, and avoid the production of embolism by the injection of air or solid particles. Give the injections slowly, and take particular care of the animals. However carefully the injections may be given, unsatisfactory results not infrequently occur. Either the animal refuses to react with the production of antibodies, or dies just when immunization is about completed. It is, therefore, good practice to immunize more than one rabbit at one sitting, in order that immune serum may be had at the time planned. as in the manufacture of precipitins. 4. With various alien cells, as erythrocytes, kidney cells, spermatozoa, etc., in the manufacture of cytotoxic serums, such as hemolysins, nephrotoxin, spermatotoxin, etc. the inoculation of horses with increasing doses of the respective toxins. The methods for preparing these antitoxins, and also of antimeningococcus, antistreptococcus, antipneumococcus, and other curative serums are given in the chapter on Antitoxins and Passive Immunization. PRODUCTION OF AGGLUTININS Agglutinating serums are frequently of much value in making a bacteriologic diagnosis of typhoid fever and cholera. For this purpose unknown microorganisms are mixed with proper dilutions of known immune serum, and the presence or the absence of agglutination noted. As a rule, rabbits are used in the preparation of these serums; for the production of larger quantities of serum, goats and horses are occasionally employed. The injections may be given intravenously or intraperitoneally; occasionally the first injections are given subcutaneously, to be followed later by intraperitoneal injections. By heating the cultures at a temperature not exceeding 60° C. for from one-half to one hour, there is less danger in the subsequent handling of the cultures and agglutinins are readily produced. 1. Use forty-eight-hour agar cultures of the organism, such as Bacillus typhosus, Spirillum cholerse, etc. Bouillon cultures may be used, but are not recommended on account of the various other constituents present in the medium. 2. With a sterilized three-millimeter platinum loop remove one loopful of culture and rub up in 2 c.c. of sterile salt solution in a small test-tube until a homogeneous emulsion is secured. 5. Give four more injections at intervals of a week as follows: Second dose: 2 loopfuls in 2 c.c. NaCl solution, heated. Third dose: 4 loopfuls in 2 c.c. NaCl solution, heated. Fourth dose: 6 loopfuls in 2 c.c. NaCl solution, heated. Fifth dose: 1 agar slant in 4 c.c. NaCl solution, heated. cepting that larger doses are given. First dose: 2 loopfuls in 4 c.c. NaCl solution, heated. Second dose: 4 loopfuls in 4 c.c. NaCl solution, heated. Third dose: 6 loopfuls in 4 c.c. NaCl solution, heated. Fourth dose: 1 agar slant in 5 c.c. NaCl solution, heated. Fifth dose: 1 agar slant in 5 c.c. NaCl solution, heated. 2. The blood is tested one week after the last injection has been made. 1. These may be produced in the same manner as the agglutinating serums, immune opsonins being readily demonstrated in the same serums. For actual diagnostic work, artificial immune opsonins are seldom required, but to secure an immune serum for experimental studies on opsonins a culture of -Staphylococcus pyogenes aureus may be used in immunizing a guinea-pig as follows: toneally. Third dose: 2 loopfuls in 2 c.c. NaCl, heated; intraperitoneally. Fourth dose: 3 loopfuls in 2 c.c. NaCl, heated; intraperitoneally. Fifth dose: 6 loopfuls in 2 c.c. "NaCl, heated; intraperitoneally. 2. Bleed the animals one week after the last injection has been made. 3. Owing to its large size, Bacillus anthracis may be substituted. This is a spore-forming organism, and since it is dangerous unless scrupulous care in handling is exercised, it is not usually wise to employ it in experimental work. PRODUCTION OF BACTERIOLYSINS (BACTERIOLYTIC SERUM) 1. These are prepared in exactly the same manner as agglutinins. In practical diagnostic work the Spirillum cholera? is most frequently used. In experimental studies of bacteriolysis the typhoid bacillus and its immune serum may be employed with equal success. Precipitin immune serums are frequently of value in making a differentiation of the proteids, as in the examination of blood-stains, meat, milk, cheese, etc. They are usually prepared by immunizing large rabbits with injections of the sterile antigen. Injections may be given intravenously or intraperitoneally, the former usually yielding the more potent serums. Any foreign serum may be used in the preparation of precipitins, such as that of the human, horse, ox, dog, cat, guinea-pig, etc. To produce an antirabbit precipitin a guinea-pig is immunized by intraperitoneal injections of rabbit serum. An antihuman precipitin serum of high titer is usually obtained with difficulty. It is good practice to immunize a number of rabbits with each antigen, as some animals will produce no precipitin whatever the method used. In preparing precipitins for the purpose of identifying blood-stains whole blood may be injected. It is better, however, to use serum only, as the immune serum may be used in diagnosis, according to the method of complement fixation, when the presence of hernolysin is not advisable. Serum Precipitins (Intravenous Method). — First Method. — Three injections are given — of 5, 10, and 15 c.c. — on each of three successive days, and the animals are bled twelve days after the last injection has been made. followed twelve days later by bleeding. Third Method. — A slower method consists in giving the injections at intervals of five days. After the third dose a few cubic centimeters of blood are withdrawn from the ear, and the serum titrated, as rabbits are most prone to succumb after the third dose, and in many instances the serum is of such strength as to require no further immunization. The animals are bled one week after the last injection has been given. Doses may be given as follows : First dose: 10 c.c. serum intravenously. Second dose: 8 c.c. serum intravenously. Third dose: 5 c.c. serum intravenously. Fourth dose: 5 c.c. serum intravenously. Fifth dose: 3 c.c. serum intravenously. Sixth dose: 3 c.c. serum intravenously. PRODUCTION OF HEMOLYSINS 71 Milk Precipitins (Lactoserums). — These are prepared by immunizing large rabbits with intravenous or intraperitoneal injections of milk, that of either the human or the lower animals. Rabbits should be immunized with at least two kinds of milk in order to obtain different lactoserums for the study of specificity. The milk used for the injections should be as sterile as possible, and if heated to 56° C. for one-half hour before the injections are made, the protein remains unchanged and the rabbits are less likely to succumb. Animals may be immunized in the same manner and with the same sized doses as were directed for the preparation of serum precipitins. Bacterial Precipitins. — It is usually customary to differentiate between the bacterial and the protein precipitins, but for practical purposes this division is superfluous, as the bacterial precipitins are simply antiserums prepared by immunization with bacterial protein. Because of their use in the serum diagnosis of syphilis and other infections, hemolysins possess great practical value. They are best produced by injecting rabbits with washed human or sheep erythrocytes, or with those of some animal of another species. Rabbits differ considerably in their power to form hemolysins, and for some unknown reason hemolysins are more readily produced with some erythrocytes than with others. It is not possible, however, to immunize every kind of animal against every type of erythrocyte. As a general rule, an animal produces a better hemolysin the more remote its relationship is to the animal from which the erythrocytes for making the injection are taken. Hemolysins may be prepared as the result either of intraperitoneal or of intravenous injections of erythrocytes washed at least three or four times to remove all traces of serum. Unless an antihuman hemolysin is required within a short space of time, better results are obtained, as a rule, by using the slower, intraperitoneal method. In immunizing rabbits it must be remembered that the quantity of amboceptor produced bears no direct relation to the size of the doses given. Thus, a highly potent hemolytic serum may be prepared by three intravenous injections of from 3 to 5 c.c. of a 10 per cent, suspension of washed sheep cells. injections should be filtered to remove small particles of fibrin, and preferably washed four times with sterile salt solution. The method of preparing corpuscles for injection has been given in a preceding chapter. After the third or fourth injection the animal should be bled from the ear and the serum tested, as animals not infrequently succumb after the fourth injection, and many possess serums of high potency after receiving three injections. By this method success is better assured. Intravenous Method. — For the preparation of most hemolysins the following methods yield very good results. Antihuman hemolysin is more difficult to prepare, and I have generally found that a slower, intraperitoneal method will yield better results. First Method. — Four injections of 5 c.c. each of a 10 per cent, suspension of washed cells at intervals of three days. The animal is bled three or four days after receiving the last injection. Second Method.— Three injections of 10 c.c. each of a 10 per cent, suspension of washed cells on each of three successive days. The rabbit is bled four days after receiving the last injection (after the method of Gay). Instead of these large injections, 1 c.c. of corpuscles, removed after thorough centrifugalization and diluted with sufficient sterile salt solution, may be given on each of three successive days. Third Method. — A slower method consists in making the injections of a suspension of corpuscles every five days. The cells must be thoroughly washed to free them from all traces of serum; if this is not done, the animals may die of anaphylaxis during the course of immunization; animals should be tested after the third dose has been injected: First dose: 3 c.c. of a 10 per cent, suspension of corpuscles. Second dose: 5 c.c. of a 10 per cent, suspension of corpuscles. Third dose: 10 c.c. of a 10 per cent, suspension of corpuscles. Fourth dose: 15 c.c. of a 10 per cent, suspension of corpuscles. Fifth dose: 20 c.c. of a 10 per cent, suspension of corpuscles. Fourth Method. — In the preparation of antihuman amboceptor, Noguchi advises giving four intravenous injections of washed cells, — 4 c.c., 3 c.c., 4 c.c., 3 c.c., — and possibly another — 4 c.c. — at intervals of four or five days; these amounts of packed cells are suspended in 10 c.c. of sterile salt solution. Rabbits are bled one week after the last injection is given. Intraperitoneal Method. — In this method the most careful aseptic precautions should be observed in washing the cells and in giving the injections, or the animals are likely to succumb from peritonitis just about the time they are fully immunized and ready for bleeding. Injections may be given every four or five days, and one week after receiving the last injection the rabbits are to be bled. This method is especially serviceable in preparing antihuman amboceptor. Whenever possible, blood should be collected aseptically, and the corpuscles washed just before the injections are given. Placental blood is likely to be infected and hemolyzed, and frequently yields unsatisfactory results. In preparing the antihuman amboceptor several rabbits should be immunized at the same time, the doses being: Fifth dose : 20 c.c. of the washed corpuscles. A combined intravenous-intraperitoneal series of injections is frequently of service in producing a highly potent antihuman hemolytic serum. Three intravenous injections of 4 c.c. each of washed cells diluted with 6 c.c. of sterile salt solution are given every five days; subsequent injections are made by giving 1 c.c. of corpuscles intraperitoneally, followed one hour later by 4 c.c. intravenously. A series of three or four of these combined injections are made at intervals of five days, the animals being tested at frequent intervals to determine the hemolytic strength of the serum. The term "cytotoxins" is usually applied to cell toxins other than hemolysins, such as nephrotoxins, spermatotoxins, etc., and although "lysin" is frequently used, the term " toxin" is better, being descriptive of the changes produced by all cell toxins except the hemolysins and the bacteriolysins. Cytotoxic serums can be made theoretically for any cell, but only the hemolysins possess much practical value. The cytotoxins are prepared with some difficulty by injecting emulsions of cells from one animal into another. Immunization should always be conducted by means of intraperitoneal or subcutaneous injection. For the purpose of studying the action of cytotoxic serum, nephrotoxic serum is preferably to be used, as the effects, e. g., the production of albuminuria, may be observed. A series of two or three animals should be carried along at the same time, as many die after the third injection. So far as possible an aseptic technic should be carried out. a nephrotoxic serum by immunizing rabbits with dog kidney. 1. Anesthetize a dog with ether, open the abdomen, wash the blood out of the kidneys by inserting a cannula high up in the abdominal aorta, and flushing with from six to ten liters of salt solution; open the vena cava. 2. Remove the kidney as aseptically as possible, and grind it in a meat-grinder; rub through fine-meshed wire gauze, and wash the residue in several changes of sterile salt solution. The fat should be rejected and only the cortex used. 7. The injection of this serum into dogs is usually followed by albuminuria and possibly hemoglobinuria. This subject is further considered under the head of Practical Exercises with Cytotoxins. Some investigators have asserted that by effecting immunization with the nucleoproteids of an organ more specific cytotoxic serums are secured. These claims have not been confirmed by Pearce, Wells, and others. (See Chapter XXV.) Nucleoproteins may be secured as follows: Grind the organ or tissue in a meatgrinder, and finally rub up with sand with a pestle in a mortar; add two volumes of normal salt solution, and pass through a meat press; collect the effluent, place in a refrigerator for twenty-four hours and then filter through gauze and centrifuge the filtrate; to the supernatant fluid add acetic acid to remove the nucleoproteins. Place hi the refrigerator for eighteen hours and centrifuge. Collect the sediment and wash several times with normal salt solution. Dissolve the sediment in normal salt solution containing 0.5 per cent, sodium carbonate. Reprecipitate with acetic acid, wash, and redissolve in the alkaline solution. IT is well to remember that serum collected shortly after a meal is likely to be cloudy or opalescent; it is therefore advisable that blood be collected several hours after eating or during a period of fasting. After securing a specimen of blood, the container should be set aside and kept at room temperature until the serum separates. If the serum is to be used at once, blood may be collected in centrifuge tubes, allowed to coagulate, and then broken up, as gently as possible, with a sterile glass rod and thoroughly centrifuged. On account of the mechanical rupture of erythrocytes, such serums are usually tinged with hemoglobin. After serum has separated from the clot it should be transferred to another tube, or, if this is not immediately possible, the container should be placed in the refrigerator, to retard hemolysis, which may soon occur and render the serum unfit for many purposes. Small amounts of serum are best removed from the clot with a capillary pipet and teat, or with an ordinary graduated pipet with rubber tubing and mouth-piece, in order that one may see exactly what he is doing and not disturb the clot. As a perfectly clear serum is always to be desired, serums mixed with corpuscles should be centrifuged. It may be stated, as a general rule, that all normal and immune serums should be collected as aseptically as possible, and handled in a careful and aseptic manner, so as to insure a clear and sterile product. Notwithstanding the method of preservation all serums should be kept in a refrigerator or ice-chest at a low temperature. PRESERVATION OF NORMAL SERUMS Normal serums that are to be used for purposes of immunization are best preserved in small amounts in separate ampules, or in a large stock bottle holding from 100 to 200 c.c. and well stoppered. In the production of precipitin-serum, for example, sufficient serum of an animal may be obtained at a single sitting for the whole course of injections, and this serum is best preserved in separate ampules. Each ampule should contain sufficient serum for one injection, and be sealed and marked. In this manner the risk of contaminating a stock bottle is obviated. In the preservation of normal serum or the serum of luetics to be used as controls for the Wassermann reaction, it is better to store them in small amounts in sterile ampules. As a rule, it is best not to add a preservative to serums that are to be used for purposes of immunization, for if the dose of serum is large, enough preservative may be injected to place the health of the animal in jeopardy. However, chloroform may be added in proportion of 1:10 or 1 : 20, provided the serum is placed in the incubator or heated in the water-bath at 40° C. for fifteen minutes in order to drive off the chloroform previous to injection. Preservation in Fluid Form with Antiseptics. — Practically any immune serum may be preserved in the fluid state by adding a suitable preservative in the proper dose without exerting any deleterious influence on the antibody content. The exceptions to this general rule are the precipitin-serums, because these should be crystal clear, and a preservative may render the serum slightly cloudy. According to Uhlenhuth, Weidanz, and Wedemann, such serums should be filtered through a 'sterile Berkefeld filter and then stored without adding an antiseptic. Various antiseptics have been advocated for the preservation of serums. Hemolytic serum is well preserved by adding an equal amount of chemically pure glycerin to the serum after it has been inactivated by heating at 55° C. for a half-hour in a water-bath. The addition of 0.1 c.c. of a 1 per cent, solution of phenol in salt solution to each cubic centimeter of immune serum usually suffices to keep the fluid free from contamination, and produces only very slight, if any, clouding. Likewise, the addition of 2 per cent, formalin in a 5 per cent, solution of glycerin in normal salt solution, in the proportion of 1 : 10, makes a very useful antiseptic. Neither lysol nor trikresol should be used in the preservation of a serum, as they are more likely to produce clouding than does phenol. Preservation in Fluid Form, by Bacteria-free Filtration. — If serums are to be preserved in fluid form without the addition of an antiseptic, special precautions in bleeding, collecting, and separating should be observed. If contamination has probably occurred, the serum should be filtered through a sterile Berkefeld filter (Fig. 34). The apparatus devised by Uhlenhuth (see Fig. 91) is especially useful, as the serum is collected at once in a sterile container, which is then plugged with sterile cotton and placed in the incubator for twenty-four hours. If the serum The fluid to be filtered is poured into the glass cylinder surrounding the earthen or porcelain "candle." Negative pressure within the candle is produced by the water-pump, which exhausts the air from the flask. The nitrate is collected in the test-tube within the filter flask. All parts are readily sterilized in an Arnold sterilizer or autoclave. The sterile cotton plug prevents air contamination. panying illustration (Fig. 35) is quite serviceable, as the flask and earthen candle-filter may be wrapped in a towel and sterilized in the autoclave. The apparatus may carefully be attached to a suction pump, and the serum pipeted off into the hollow of the candle and filtered, the filtrate being removed, at the completion of the process, by another sterile pipet. The cotton plug in the " candle" is removed and the fluid poured within the candle (hollow). The water is then turned on and the stop-cocks are opened; a vacuum is produced within the flasks, which draws the fluid through the candle. The filter is readily cleansed and sterilized (autoclave) and is quite efficient. Care should be exercised regarding the reaction of Berkefeld filters and particularly new filters. Before use they should be boiled in distilled water at least three times for five minutes each time, and scrubbed with a small soft brush after each boiling. After the filter is set up, hot, neutral, distilled water should stand in it for about five minutes and then washed through under gentle pressure until the fluid is clear and neutral to phenolphthalein, when the filter is ready for use. After use, the filter should be boiled in distilled water, scrubbed, and dried in the air. Preservation in Fluid Form, by Freezing. — Freezing a serum often renders it cloudy or causes a precipitate to be deposited, and interferes with the usefulness of a serum that should be absolutely clear. Freezing is the only practicable method so far devised for the preservation of thermolabile substances, such as complement. A small apparatus, named the "Frigo," has been devised for this purpose by Morgenroth. A satisfactory apparatus may be made by constructing a wooden box with a smaller sheet-metal-covered inner compartment, the space between them being well packed with sawdust. This inner box is then filled with crushed ice, and the whole is covered with a lid lined with several layers of felt. Preservation in Powder Form. — When serum is poured out in thin layers and dried, it forms yellowish, amorphous masses, that may be collected and ground into a powder, which keeps well and forms an excellent medium for the preservation of many immune serums, especially those of the agglutinating type. Various toxins, such as tetanus toxin and cobra venom, may also be preserved in this form. The serum or toxin may be spread out in thin layers on large glass plates, or placed in shallow dishes and dried in the incubator. After a few hours the dried serum, which adheres only slightly to the dish, can be removed with a spatula and placed in a mortar, and ground and stored in sealed tubes. The drying process is better carried out in vacuo, and the large serum institutes are provided with these special drying apparatus. A simple form may be prepared after the method of Taeze, as follows: Place a large glass bell-jar with a ground base and a large opening at the top on a polished iron plate. Set this on a large tripod, as this will facilitate heating with a Bunsen burner. The serum is placed within the jar in a shallow dish, and the jar fastened to the iron plate with hot paraffin or wax. The opening at the top is closed with a three-holed rubber stopper: one hole carries a thermometer; a second is connected with a manometer (not absolutely necessary), and the third carries a bent glass tube which is connected, by means of thick-walled rubber tubing, to a suction pump. A low flame is kept burning so as to keep the temperature at about 35° C. The degree of vacuum secured makes little difference, and usually that obtained with an ordinary water-suction pump, allowing for leaks in the tubing, is sufficient, rendering manometric measurements unnecessary. 80 THE PRESERVATION OF SERUMS METHODS I have secured equally good results in evaporating sera and tissue extracts with an ordinary electric fan enclosed in a properly sized oblong wooden box to concentrate the air current. before it is used. Preservation in Dried Paper Form. — This is a very serviceable method for preserving hemolysins, and to a lesser extent, agglutinins. In the preservation of hemolytic amboceptor Noguchi advises the use of Schleich and Schull's paper No. 597. The paper is cut into squares about 10 by 10 cm., and saturated with the serum which, after preliminary titration, has been found satisfactory. Sufficient serum is added to wet the sheets evenly, any excess of serum being absorbed with other sheets of paper. Each square is placed separately upon a clean sheet of unbleached muslin and dried at room temperature. When thoroughly dry, the squares are carefully ruled off with a hard pencil into widths of about 5 mm., and cut into strips. The paper is then standardized and preserved in dark glass vials in a cool, dark place. Preservation in the Living Animal. — In the living animal an immune serum may be preserved by removing a small amount of blood from time to time as needed, the titer being preserved or raised by occasional injections. This method, however, may be unsatisfactory and expensive, especially with the smaller animals, as they frequently show a marked tendency to sicken and die, or may succumb to anaphylaxis. After a time, too, they fail to respond to injections with the formation of antibodies, a condition ascribed to atrophy of the cellreceptors (receptoric atrophy). the tissues of the body. The skin and adjacent mucous membranes contain numerous microorganisms, and under normal conditions these may invade the tissues, but they are usually quickly destroyed and unable to proliferate, so that mere invasion does not necessarily constitute infection. Unfortunately, custom has sanctioned the use of the term infection as synonymous with contamination. The bacteriologist may speak of the air, water, or his culture medium as being infected when they contain microorganisms, or, in other words, are not sterile; similarly the surgeon may speak of a knife or splinter of wood as being infected whereas, while these may be infective or capable of producing infection, it is more accurate to speak of them as being contaminated. In the early days of bacteriology, the mere presence of microorganisms in or on the skin and mucous membranes was regarded as equivalent to infection. It is now well known that a person may harbor various microorganisms, such as staphylococci, streptococci, and pneumococci, without apparent injury to the host, and this surface contamination, or even occasional invasion of the tissues, does not necessarily indicate that the host has been, is, or will be ill. Definition. — When, however, microorganisms have passed the normal barriers of the skin or mucous membranes and have invaded and proliferated in the deeper tissues, the process is spoken of as an infection. By common consent, the term infestation, or infestment, is being applied in a similar manner to the presence and growth of animal parasites; thus the intestine may be infected with Bacillus typhosus and infested by Taenia saginata. A microorganism may be intimately associated with and have its normal habitat in a certain part of the body and do no harm until special conditions arise, when it may rapidly invade the tissues and produce infection; this condition has been described by Adami as a subinfection, and is illustrated by the constant presence of staphylococci and strepto6 81 special conditions, of producing severe and even fatal infection. The abnormal state resulting from the deleterious local and general interaction between a host and an invading bacterium, with consequent tissue changes and symptoms, constitutes an infectious disease. As has previously been stated, not every invasion of the deeper tissues by microorganisms results in injury or disease. A certain number of bacteria are constantly gaining admission to the deeper tissues of the alimentary and the respiratory tracts, without producing apparent injury to the host, as they tend to be destroyed very soon after they gain entrance. Furthermore, bacteriologic studies of lymphatic glands and other tissues removed during life or soon after death at autopsy, not infrequently show the presence of diphtheroicl bacilli and other microorganisms possessing feeble or no demonstrable pathogenic powers and indicating that various bacteria may gain* access to the deeper tissues without producing a true infection. The terms invasion and infection are not, therefore, synonymous. Every true infection is accompanied by local changes, although these may be so slight as to escape notice; an infectious disease is practically made up of similar phenomena, but these are of an exaggerated or marked degree. The hygienist distinguishes between — (1) Sporadic, or isolated, cases of infection; (2) endemic, in which a certain microbic disease affects the inhabitants of a given area year after year; and (3) epidemic, in which a disease appears suddenly and affects a large number of inhabitants, the number of cases rapidly increasing and decreasing. Among the lower animals equivalent terms for the types just described are sporadic, enzootic, and epizootic. A pandemic disease is one that is epidemic over a large territory. In all infections there are two inseparable factors to be considered : 1. The offensive forces of the infecting agent, dependent upon its pathogenic or disease-producing nature and its power of defending itself against the antagonistic forces of the host and of thriving under these conditions. 2. The resistance offered by the host, and mainly dependent upon certain physical or non-specific local factors or specific antibodies, which constitute the defensive mechanism, or immunologic factors. the latter with that of immunity. Microorganisms and host may live together in apparent harmony, owing to the ability of the host to restrain the activity of the microorganism and neutralize its injurious effects or to an absence of infec- SOURCES OF INFECTION 83 tivity on the part of the microorganism until the vital resistance of the host is diminished or the pathogenicity of- the microorganism is increased, when the neutral relations are disturbed and infection occurs. RELATION OF INFECTION TO IMMUNITY From what has been said, it is apparent that the subject of infection forms the basis for the study of immunology, for, paradoxic as it would at first appear to be, infection must usually have occurred in order that immunity may be acquired. This relation is not always apparent; for instance, man and some of the lower animals may possess a natural immunity td a certain parasite because of the presence of various physical or non-specific defensive factors, or to specific antibodies produced as the result of an earlier and unrecognized infection, or even one that has been inherited; under any circumstances, however, natural immunity is usually relative and seldom absolute. In passive immunity the same conditions are generally operative, and the antibodies present in the serum used to confer a passive immunity are produced in some other animal as the result of an active infection. It may be stated, therefore, that specific antibodies are produced only by stimulation of the body-cells, and that this stimulation is furnished by the infecting agent either in living, disease-producing form, or in a modified and attenuated state, i. e., in the form of a vaccine; thus it will be seen that infection and immunity are intimately associated, and that, 'generally speaking, there can be no pronounced protection unless infection has taken place. Bacteria are to be found everywhere. For general purposes they may be roughly divided into two classes — saprophytes and parasites. The saprophytes are those bacteria which thrive best in dead organic matter, and perform the very important function of reducing, by their physiologic activities, highly organized material into those simple chemical substances that may again be utilized by the plants in their constructive processes, and in this manner maintain the important chemical relation between the animal and the plant kingdom. Parasites, on the other hand, find the most favorable conditions for growth and activity upon the living tissues of higher forms of animal life. They include most of the so-called pathogenic or disease-producing bacteria. 84 INFECTION terms are merely relative, and bacteria ordinarily saprophytic may develop parasitic and pathogenic powers when the resistance of the host is sufficiently reduced by another infection, fatigue, exposure, or other deleterious influence. In other words, a pathogenic microorganism is one that can grow in the living tissues because the immunologic defenses of the host are not sufficiently strong to resist it; in most cases, however, as will be pointed out further on, a higher degree of immunity can be produced artificially, rendering the bacterium in question relatively harmless for that particular animal. Similarly, under certain circumstances, the resistance of the body or of a part of it may be broken down to such an extent that microorganisms ordinarily regarded as saprophytes may gain access to the deeper tissues, flourish, and produce disease. Accordingly, no fundamental distinction between pathogenic and non-pathogenic bacteria can be made. Any apparent differences are due not only to various degrees of pathogenicity possessed by the microorganism, but also to the different degrees of resistance against their attacks, since a microparasite that is highly pathogenic toward one animal, may be quite harmless to another. CONTAGIOUS AND INFECTIOUS DISEASES Just as all pathogenic bacteria do not possess the same habits of growth, so, likewise, they vary in their vitality and in their ability to proliferate under various conditions when removed from the animal body. Some are strictly parasitic, and are able to grow only at body temperature, or, indeed, only in the human body itself; when removed from these conditions, they may retain their vitality for a short period of time, but are unable to proliferate: from this it follows that communication of these bacteria and their disease must be direct or immediate, i. e., from person to person, or almost direct, by the conveyance of the infecting agent in the form offomites, such as dust, epidermal scales, or discharges, or as the result of bites of suctorial insects. This form of infection, which requires such direct means of transmission, and of which gonorrhea is an example, constitutes what are known as contagious diseases. Other microparasites are not so strictly parasitic; they may be able to preserve their pathogenic powers and proliferate outside of the body at ordinary temperatures, and may even withstand great extremes of heat or cold and various nutritional deficiencies; they may exist thus for weeks, and carry the disease to a second individual through con- There are no hard-and-fast rules that can be set down in classifying bacterial infections; bacteria that are commonly transmitted by one means may, under slightly altered conditions, be transmitted by another. The usual classification, by which certain diseases are classified as contagious and others as infectious, should be abolished, and all should be grouped under the term infectious, there being a definite understanding of those cultural characteristics that render infection more likely to occur by direct and immediate contact, and those that may occur in an indirect or roundabout manner. It may therefore be stated that all bacterial diseases are infectious; the term contagious may be reserved for those spread or contracted as the result of direct contact. EXOGENOUS AND ENDOGENOUS INFECTIONS Infection may occur as the result of the admission of microparasites to the tissues from sources entirely apart from the individual infected (exogenous infection), or from the admission of some of those microparasites living normally and harmlessly on the skin and adjacent mucous membranes, and which, under special conditions, have assumed pathogenic properties (endogenous infections). tact with infective material outside the body. 1. Microorganisms, such as typhoid and cholera bacilli, which can live for varying periods of time in water and foods, are particularly likely to gain entrance through the gastro-intestinal tract. Microorganisms may be present in milk derived directly from diseased animals or tissues, .and when ingested, may produce disease. Thus, for example, the germs of tuberculosis may be conveyed in either milk or flesh, young children being particularly exposed to this method of infection. 2. The atmosphere may be laden with microorganisms, which, whether or not capable of proliferating outside of the body, are prone to gain entrance through the respiratory tract, especially through the upper air-passages, the pharynx and tonsils being often the seat of the infection. 3. Microorganisms capable of existing on the skin may gain entrance to the deeper tissues as the result of wounds. Under these conditions of lowered vitality of the local tissues microorganisms that would otherwise be harmless may become pathogenic and morbidly affect the host, either locally or generally. As the skin is brought so freely in contact with external objects, various microorganisms, and particularly the pathogenic cocci, may gain entrance to the dermis. Wounds may be infected by the teeth and secretions of animals, or by various weapons and implements contaminated with infective material, as, e. g.} the virus in the saliva of rabid dogs, or the spores of the tetanus bacillus on rusty nails. Contact with unclean objects of various kinds — eating utensils, catheters, syringes, dental instruments, etc. — may serve to transfer pathogenic bacteria from one person to another. This is especially likely to occur if the skin or mucous membrane is abraded, the infecting parasites thus gaining ready access to the deeper tissues. In some infections, however, even this local injury is unnecessary, as the bacterium may be able to proliferate and produce lesions on an intact surface, as, for instance, the diphtheria bacillus in the pharynx, and various fungi, such as Achorion, Trichophyton, etc., on the scalp and skin in general. parturition. 4. Suctorial insects may serve as the medium by which microorganisms are transmitted from person to person. In most instances the transmission is a purely mechanical process, as witness the transmissions of the plague bacillus in the intestinal contents of the rat flea; in the case of malaria, on the other hand, the interposition of the mosquito is essential to complete the life cycle of the protozoon. way of the umbilical vein. Endogenous infections arise as the result of the activity of microorganisms having their normal or customary habitat in the body. Such infections do not represent so much an assumption of pathogenic power on the part of the microorganism, as they do a disturbance of the defensive mechanism of the host, whereby the normal relations are disturbed, and microorganisms that normally are harmless, become infective and disease-producing. While the disturbance of the defensive mechanism may be general, it is far more likely to be local ; an example is that of appendicitis the result of Bacillus coli infection following passive congestion due to fecal impaction of the colon. being a general infection. Owing, however, to the peculiar pathogenic properties of different bacteria and their affinity for the cells of certain tissues, coupled with a peculiar tissue susceptibility for certain bacteria or their products, we find that many diseases have regular avenues of infection, and, indeed, in a few instances infection of the human body may be possible only through a particular and definite route. Infections of the gastro-intestinal, respiratory, and genito-urinary tracts and various sinuses with external openings must be considered as being potentially surface infections. The outer layers do not consist merely of the skin and adjacent mucous membranes, but are made up of all layers covering surfaces and channels, which, however indirectly, communicate with the exterior. In the higher animals there is only one direct channel of communication between the actual interior and the exterior of the body, this being through the Fallopian tube of the female, which normally has so fine a lumen and is so well protected that to all intents and purposes it may be regarded as closed. In certain inflammatory conditions of the genital organs, and particularly after parturition, the Fallopian tube may be open, and afford a direct route for the transmission of infection from the external parts to the peritoneal cavity. Living in and on the actual and potential external surfaces are countless microorganisms, which are for the most part harmless, a few being, however, actually or potentially dangerous. 1. The skin and adjacent mucous membranes, particularly in those portions where warmth and moisture abound, are well adapted to bacterial growth, and their contact with surrounding objects causes a large variety of microorganisms to adhere to them. As a result, the bacteriology of the skin is quite complex, since it may lodge microorganisms from the air, from water, and from soil. A group of cocci and diplococci, particularly the Staphylococcus epidermidis albus of Welch, and the various pseudodiphtheria bacilli, are habitually present upon the human skin. When local injury occurs, they may produce minor suppurative lesions, and may be concerned in the production of certain skin diseases, such as eczema, impetigo contagiosa, the pustules of variola, etc, Other microorganisms may find temporary lodgment upon the skin, and are in no sense regular inhabitants. For example, the fingers and hands may become contaminated with colon, typhoid, and tubercle bacilli, pneumococci, etc. bacteria into the deeper tissues. The greater number of local surgical infections result from the entrance of bacteria into lesions of the skin, although these lesions may be so small as to escape notice. Certain parasites are capable of producing direct action on the skin without previous existing injury, and especially upon the mucous membranes, where moisture and higher temperature are more favorable to bacterial growth. For example, a few of the higher fungi, such as Microsporon, Achorion, and Trichophyton, seem able to establish themselves in the superficial cells and invade the deeper tissues through the hair-follicles; staphylococci may reach the roots of hair-follicles and sweat-glands and set up suppurative conditions; diphtheria bacilli may lodge directly on the intact mucosa of the upper air-passages and cause local necrosis and general intoxication ; cholera bacilli may have a similar effect upon the intestinal mucosa; the Koch- Weeks' bacillus and the gonococcus may produce severe inflammation of an intact conjunctiva, etc. 2. The respiratory organs commonly afford admission to certain microorganisms. The nose may be the seat of local infection with Bacillus influenzse, Micrococcus catarrhalis, Bacillus diphtherias, and other bacteria; it may be the entrance point for meningococci and the virus of anterior poliomyelitis. Similarly, the entrance of such unknown infectious agents as those of scarlet fever, measles, and smallpox can best be accounted for by assuming that they were inhaled and later entered the blood; there is much clinical evidence to support the belief that the contagium of scarlet fever is present in the discharges of the upper air-passages of persons suffering from that infection. Whether or not tuberculosis of the lungs is the result of the inhalation of tubercle bacilli is a much-disputed point, but it cannot be denied that this theory most readily accounts for the far greater frequency with which tuberculosis affects the lungs than it does other organs of the body. Pneumonia, caused by the pneumococcus of Weichselbaum, probably results from the direct inhalation of one of the various types of pneumococci, and bronchopneumonia of children is certainly chiefly inspiratory in origin. 3. The digestive tract may be the portal of entrance of many infections. The mouth usually harbors various fungi and bacteria,which may produce local infections, and either directly or indirectly cause caries of the teeth. The -putrefactive changes they may produce is being generally recognized as having an important bearing on the causation and symptomatology of several infections, and a carious tooth has been found the portal of entry of microorganisms causing a general infection. The tonsils are well known to be the breeding- and lodging-place of various microparasites causing many general infections, such as acute rheumatic fever, tuberculosis, and possibly typhoid fever. The pharynx may harbor the microorganisms of diphtheria, pneumococcous angina, etc. Normally, except for the presence of a few sarcinse, the stomach is practically sterile. Under special conditions, however, typhoid, dysentery, cholera, tubercle, and other infectious bacteria may escape the germicidal effects of the hydrochloric acid, and, reaching the alkaline intestinal contents, which are rich in soluble proteins and carbohydrates, are rendered capable of producing their respective infections. Although these conditions are primarily of the nature of local infection, there is much experimental evidence to show that bacilli, and particularly tubercle bacilli, may pass through a practically intact intestinal wall and find their way to the lymph-glands or to the bloodstream itself. Aside from these direct and specific infections, various other microorganisms, by fermentative action, may alter the intestinal contents and produce toxic products capable of exciting acute and severe toxemias. Some authorities as, e. g., Metchnikoff, regard the various types of colon bacilli as producing toxic products responsible for chronic degenerative lesions of the cardiovascular and other organs. The digestive tract is therefore regarded by some pathologists as a constant menace to health, in that it permits bacteria to enter the lymphatic and blood-streams, or to produce toxic substances detrimental to health and longevity. Adami has drawn particular attention to a condition which he terms suhinfection, and which is dependent upon the constant entrance of colon bacilli into the blood, whence they enter the liver, where their final dissolution takes place, appearing as fine, dumb-bell-like granules inclosed in the cells. 4. The genital organs are the seat of various local infections that may become wide-spread and general. Normally, the urethra may contain a few cocci which lodge about the meatus; the acid secretions of the vagina are generally inimical to bacterial growth, and the uterus and bladder are usually sterile. But three microorganisms — the gonococcus, Treponema pallidum, and the bacillus of Ducrey, here find favorable conditions for growth, and are usually transmitted from person to person by means of sexual congress. The local gonococcal lesion may be the portal of entry of gonococci into the blood-stream, resulting in wide-spread metastases in the heart valves and joints. The local syphilitic lesion is quickly followed by general infection. Chancroids alone remain localized, although the initial lesion frequently spreads quite rapidly by continuity of tissues. In rarer instances other microorganisms, such as the ordinary pyogenic cocci, tubercle bacillus, and diphtheria bacillus, may infect these organs and be transmitted by sexual conjugation. 5. There is considerable controversy of opinion regarding the susceptibility of the placenta and the filtering properties it possesses for various infectious agents. A study of this subject by Nee' low1 would indicate that the non-pathogenic bacteria do not pass from the mother through the placenta to the fetus. Other pathogenic agents may, however, pass through quite readily, for example, pregnant women suffering from smallpox may be delivered of infants showing active lesions of prenatal infection, and syphilitic infection of the fetus is a well-known condition. Most controversy centers around congenital tuberculosis, and directly opposing views for and against prenatal infections are held by several authorities. Baumgarten is of the opinion that many children are subject to antenatal infection, though the disease infrequently develops in a few of them. NORMAL DEFENSES AGAINST BACTERIAL INVASION When the large area of the body that is subject to traumatic injury and accidental infection is considered, it is remarkable that, considering the enormous numbers of various bacteria, infection does not occur more frequently. Bacterial invasion of the tissues is of frequent occurrence, but in health they do not usually cause infection, and tend to be destroyed very soon after they enter the tissues. It may be well to discuss at this point the factors tending to prevent invasion, and leave the consideration of the defensive mechanism, whereby the body destroys bacteria after successful invasion and thus prevents infection, for the chapter on Natural Immunity. MECHANISM OF BACTERIAL INVASION 91 cells offer a mechanical obstacle to invasion. This resistance is naturally more complete where the cells are thickened and most compact. In the depths of glands and in mucous membranes, where numerous glands are present, and where the layers are thinner and moisture exists, the barrier is less complete. 2. Surface discharges are potent factors in preventing bacterial invasions by — (1) Washing away the bacteria mechanically; (2) by germicidal activity through the presence of various chemical agents, such as acids, which they may contain, and (3) by antiseptic and even bactericidal substances that may be present in the form of antibodies. The saliva, with its antiseptic and germicidal properties, is potent in preventing infections of the mouth and upper air-passages; when this secretion is diminished, as during the course of high fever, bacterial activity is enhanced, which is evidenced by the development of fetid sordes about the teeth and on the lips. The acidity of the gastric juice and its germicidal powers are well known and appreciated; similarly the urine, the milk, and to a slight extent, the bile, have been demonstrated by "Adami to exert a distinct antiseptic effect upon certain bacteria, such as the Bacillus coli. Surface moisture and discharges about the nose and throat are also potent factors in mechanically removing bacteria from inspired air, and no doubt frequently prevent bacterial invasion of the lower respiratory tract, where more mischief may be done. We will now consider the method by which invasion, the first step of what may be an infection, is brought about. In brief, one or all of the normal defenses just described must be overcome; in some instances the microorganisms, by their inherent disease-producing powers, may accomplish this unaided; in other instances the resistance is overcome by a general lowering of the vitality of the body defenses. 1. Traumatic solution of the surface layers of epithelial cells is a very important factor in the production of infection, as the invading microparasites are thus given easier access to the deeper and less resistant tissues. The pathologist or surgeon may, in the course of his work, contaminate his hands with secretions containing virulent microorgan- 2. As has been previously stated, certain bacteria, notably the diphtheria bacillus, by concentrating at one point, may lower the vitality and cause necrosis of superficial cells of the mucosa lining the upper airpassages, and in this manner induce a local break in the continuity of the epithelial covering. Staphylococci may exert a similar action in the depths of sweat and sebaceous glands, and, indeed, certain fungi, such as the Trichophyton, Microsporon, and Achorion, may attack the intact skin. While, therefore, solution of the surface coverings is a very important source of many infections, it is not essential for the production of all. 3. Alterations of the surface discharges, either in quantity or in quality, may permit bacteria to proliferate freely and produce sufficient toxic matter to affect the surface cells, lower their vitality, and destroy them, with the result that they may gain entrance to the deeper tissues. When the secretions are diminished or altered, as, for example, the saliva during a fever, unless the mouth is carefully and frequently cleansed, it becomes putrescent with bacterial growth. Similarly catarrhal gastritis, or any other factor tending to lower acidity of the gastric juice, favors infection by this route. 4. Not infrequently bacteria may gain access to the deeper tissues or to an internal organ, and infection may occur without any recognizable solution of continuity of the surface epithelium. In these hidden or "cryptogenic infections" the entrance point of the parasites may be healed over, or the infecting microorganisms may have been carried to the circulating body fluids by the wandering cells. Not infrequently, in cases of tuberculosis of the cervical and mesenteric glands in children, there may be no signs whatever of local irritation in the fauces or in the intestine to explain the source of infection. The tonsils are now strongly suspected, and indeed known to be, the source of entry of bacteria causing several acute and chronic infections. The leukocytes, in their phagocytic activities, no doubt, play an important role in the production of cryptogenic infections, especially when an excessive number of pathogenic bacteria have congregated at one point, and congestion, increased leukocytic infiltration, and a lowered vitality of the tissues have occurred prior to the invasions of microorganisms. Wandering cells are commonly found on mucous membranes, gathering up various bacterial and cellular debris. They may carry a virulent microorganism into the deeper tissues, and, al- causing infection. 5. Aside from the question of local conditions in the process of infection, other factors may exert an influence. The temperature of the host may be unsuitable for the growth of a certain parasite, even though it has gained entrance to the deeper tissues; a particular route for the introduction of the infecting agents may be necessary, as in typhoid fever and cholera, which are probably always intestinal infections, and, finally, even after the infecting agent has reached the deeper tissues, extension is prevented by a local inflammatory reaction. In many such instances the question of natural immunity is brought into intimate relation with the subject of infection. After invasion has occurred, some bacteria can best sustain themselves against the defenses of the host at the local point of entry. Such microorganisms may, however, possess unusual vitality, and indirectly, through the lymphatics, find their way to the blood-stream, producing a bacteremia. This is a morbid condition characterized by the presence of microorganisms in the circulating blood. Some microorganisms may gain entrance to the general circulation more readily than others, and their mode and route of entry vary in the different infections. It is essential that they possess an unusual degree of invasive power, and be capable of protecting themselves against the manifold defensive factors contained in the blood. Kruse believes that in local infections the high pressure of an inflammatory exudate may force bacteria into the adjacent vessels; that they may sometimes be carried into the deeper tissues, and even into the blood-stream, by leukocytes is not to be denied. When bacteria have entered the circulation, they may act as emboli in the finer capillaries, or, being unable to remain in the circulation, may collect in the capillaries of less resistant tissues, proliferating and producing local metastatic lesions, usually purulent in character. The condition thus produced is known as pyemia. Saprophytic bacteria or pathogenic bacteria of feeble invasive powers may be able to grow in diseased tissues, such as gangrenous areas, and may assist in effecting morbid changes, producing toxic products of decomposition, which when absorbed into the body, give rise to a series of toxic phenomena, such as fever, rapid pulse, malaise, etc. This condition is known as sapremia, a term that has also been applied to the decomposition of relatively sterile organic material and absorption of are retained in the uterus after childbirth. The term toxemia is employed rather loosely to mean the presence of any toxic material. Its use should be limited to the condition resulting from the absorption of the poisonous substances produced by the non-invasive bacteria themselves, as in diphtheria and tetanus. Septicemia is the term applied to the presence in the body-fluids of toxic products generated by the pyogenic microorganisms. In recent years considerable attention has been given the subject of focal infection, that is, the primary focus of such systemic diseases as acute rheumatic fever, endocarditis, chorea, and chronic rheumatoid arthritis may be located in the head and usually in the form of alveolar abscesses and acute and chronic tonsillitis and sinusitis. Foci of infection may also be located in the genito-urinary and intestinal tracts and careful bacteriologic examinations of sputa, urine, and urethral discharges and exudates of synovial cavities, 'of excised lymph-nodes proximal to the infected regions and of bits of infected muscles and tendons, have often yielded results of diagnostic value and indicated the etiologic relation of the focus of infection to existing systemic infection. The subject is one of considerable importance and deserving of continued clinical and bacteriologic investigation. An excellent review of this subject based mainly upon the investigations of the Chicago School of Clinicians and Bacteriologists has been recently made by Billings.1 MECHANISM OF INFECTION Since bacterial invasion is of frequent occurrence, the question naturally arises, Why are not infections, both local and general, more frequent? Thus abrasions of the surface epithelium are not uncommon in the presence of active microorganisms; tubercle bacilli may be inspired, and typhoid bacilli may be swallowed, the altered local conditions affording opportunity for producing infection, and yet the host may escape. of the host through special agencies aside from their offensive forces. Not all these factors must necessarily be present before infection may occur. A microorganism may be particularly virulent, so that numbers are relatively unimportant; a host or a portion of the host may be so susceptible or vulnerable to infection that a microorganism of low virulence, which, under normal conditions, would be totally unable to produce infection, may now prove pathogenic. VIRULENCE Virulence refers to the disease-producing power of a microorganism, and is dependent upon two variable factors: (1) Toxicity, and (2) aggressiveness, or the invasive power of the bacteria. In most infections usually both factors are operative. Toxicity is the term applied to the kind and amount of poison or toxin produced. This poison may be readily soluble, or exogenous, diffusing into the surrounding tissues and being readily absorbable; or it may be endogenous, and contained chiefly within the microorganisms, and be liberated only upon the dissolution of the bacterial cell. Aggressiveness is a term applied to the invasive powers of a microorganism to enter, live, and multiply in the body-fluids, or, in other words, to the aggressive or progressive forces of the microorganism in its new environment. Toxicity is generally confused with aggressiveness, a highly toxic microorganism being regarded as an aggressive one. For example, the bacillus of tetanus is highly toxic because of the production of a potent soluble poison which gives rise to the symptoms of tetanus, although it is only slightly aggressive, being almost unable to multiply in the tissues. The anthrax bacillus, on the other hand, is highly aggressive, owing to the fact that it usually multiplies to such an extent that it can be found in each drop of blood and in every organ of an infected animal; nevertheless it is but slightly toxic, the animals frequently showing few or no symptoms until shortly before death. The toxicity of a microorganism should, therefore, be regarded separate from its aggressiveness, although in many infections both factors are so intimately concerned that the term virulence may be used to express the degree of pathogenicity or the total disease-producing power. toxin produced by one species is different from that produced by another in the kind of disease produced and the species of animal infected. Some toxins are active for certain animals only and not for others. Microorganisms of one group may possess general and common pathogenic properties differing only in degree; those of different morphologic and cultural characters may possess totally different powers. The virulence of a given species is subject to great variation. A few bacteria almost constantly retain their virulence, even when kept for years under artificial conditions; as an example may be mentioned the diphtheria bacillus; others quickly lose their virulence as soon as they are grown artificially, as, e. g., the influenza bacillus; in others — and probably the larger class — the virulence may be raised or lowered according to the experimental manipulations to which they may be subjected. Variations may also be observed among members of the same group of microorganisms, and even among individual microorganisms of the same strain. Decrease of virulence of a microorganism may be brought about artificially by repeated growth in or upon culture-media, especially when transfers to fresh media are made at prolonged intervals. This decrease probably depends upon an actual decrease in virulence, and particularly upon the selection, in artificial growth, of the less virulent or vegetative forms which grow actively and soon exceed in number their more pathogenic fellows. Each time the culture is transplanted more of the vegetative and fewer of the pathogenic microorganisms are carried over, until finally the pathogenic bacteria are entirely eliminated, or their virulence totally destroyed, and the entire culture is composed only of vegetative or harmless forms of bacteria. Various other agencies lead to artificial lessening of virulence, such as exposure, for short periods of time, to a temperature just under the thermal death-point; exposure to sunlight; exposure to small quantities of antiseptic or germicidal substances; the action of desiccation; subjection to increased atmospheric pressure, etc., these methods being commonly employed in the preparations of vaccines to be used for purposes of active immunization. The passage of a microorganism or virus through animals usually increases its virulence, but may modify or attenuate it, as in the case of the passage of smallpox virus through the calf, when it loses forever its power of producing smallpox. make a known non-virulent microorganism virulent, although it is comparatively easy to increase the virulence of a culture that has become well-nigh non-virulent on account of prolonged artificial cultivation. This fact is worthy of emphasis, and is well illustrated by the large amount of work that has been done in fruitless attempts to render non-virulent, diphtheria-like bacilli virulent by passage through various animals or growth on special culture-media. In cases where the virulence is slight or absent, experimental manipulations of the culture are directed toward gradual immunization of the microorganisms to the defensive mechanism of the body of the animal for which the organism is to be made virulent. This is well explained according to the hypothesis of Welch, and will be referred to again in the latter part of this chapter. A number of methods are made use of for this purpose: (a) Passage through animals, which enables the microorganisms gradually to immunize themselves or adopt certain morphologic and biologic changes enabling them best to resist the defensive forces of the host. Since these defensive forces vary with different animals, and indeed with the various organs of the same animals, it is usual to find that virulence raised by animal passage affects only the animal or the particular organ of a certain animal, and not all animals in general. Thus, in general, the passage of bacteria through rabbits increases their virulence for rabbits and not for mice, dogs, pigeons, etc.; passage through mice may increase their virulence for mice, but not for rabbits, guinea-pigs, etc. (b) The use of collodion sacs for increasing virulence has been advocated, especially by French investigators. When microorganisms are inclosed in a collodion capsule of the proper thickness and placed within the abdominal cavity of a suitable animal, the slightly modified body-juices are able to transfuse through the sac, impeding the development of such microorganisms as are unable to immunize themselves or withstand the injurious influences. In this manner a race of virulent bacteria are artificially selected which can endure the defensive agencies of those juices with which they have come into contact. (c) The addition of animal fluids to the culture-medium may enable the bacteriologist to maintain or even to increase the virulence of a microorganism according to the principles of artificial selection. The fluid, either a serum or whole blood, is secured in a sterile manner and added to the medium in a raw or unheated condition. In this manner the microorganisms are exposed to some of the defensive agencies con- tained in the juices under these conditions, and this tends to destroy the less resistant bacteria, encourage the more resistant, and at least maintain, for a longer or a shorter time, the virulence of a culture freshly isolated from a lesion or cultivated by animal passage. THE AVENUE OF INFECTION AND TISSUE SUSCEPTIBILITY Successful infection of the body by certain bacteria can be accomplished only when invasion takes place through appropriate avenues. Thus typhoid, cholera, and dysentery infection seems to take place through the gastro-intestinal tract, and doubtfully by inhalation, and not at all through the skin or urogenital system; gonococci usually enter the body through the genital organs or the eye, and not through the respiratory apparatus or through the skin. The route of infection is less important with microorganisms characterized by great aggressiveness and producing general, rather than local, infections. For example, in most animals anthrax is a general bacteremia, regardless of the route of invasion; plague rapidly becomes a bacteremia, whether the bacilli are inhaled, rubbed into the skin, or reach the lymphatics through superficial abrasions; similarly, local staphylococcus and streptococcus infection may become general, regardless of the route of invasion or the location of the local lesion. The avenue of invasion is also of importance in determining the form, nature, and virulence of an infection. Thus virulent pneumococci lodging in the pharynx may produce a pseudomembranous angina; in the eye, a severe conjunctivitis; and in the lungs, a pneumonia. When tubercle bacilli gain admission through the skin, they may produce lupus, or a low-grade inflammatory disease rarely terminating fatally. When inhaled, they may produce tuberculosis of the lungs; in the throat they may reach the tonsils and later the local lymphatic glands, etc. When swallowed, they may produce ulceration of the intestines, or pass through the intestinal walls and involve the mesenteric glands, and later the lungs or other organs. Just as general susceptibility of the host renders infection more likely to occur, so local susceptibility may be induced by injury and fundamental disorders. These changes may not only furnish pabulum for the invading bacteria, but more especially reduce the local resistance of the body defenses. growth. Selective Tissue Affinity. — While the primary focus of infection is determined largely by the route of invasion, the selective affinity of microorganisms or their toxins for certain tissues and the inherent tissue susceptibility to the toxins are best in evidence in the location of secondary foci or localization of the infection in general bacterernias. Thus the seat of the principal local lesions in pneumonia is the lungs, and in typhoid fever the lymphoid tissues, especially that of the spleen, and Fever's patches in the intestine. It is true that mechanical factors may aid in this selection, as, e. g., the occlusion by emboli of microorganisms caught in the capillaries of organs; but, in general, we must conclude that either — (1) Microorganisms tend to be destroyed in every tissue or organ except those that are poor in defensive forces and are susceptible, or (2) that microorganisms or their products circulate passively through a tissue and do not lodge because they possess no affinity for these cells. In many infections both processes are probably operative, and at least we are led to the very important conclusion, laid down by Adami, that "in infections the body is never involved as a whole. Coincidentally with the growth of the specific germs in individual organs there tends to be a reaction to, and destruction of, the same in other parts." Nickols and Hough1 and Reasoner2 have isolated strains of Treponema pallidum from the nervous tissues that appeared to have selective affinities for the cornea, choroid, and retina of the eyes of rabbits; Noguchi3 has noticed that various types produced lesions in rabbits of certain distinct characters and with considerable constancy. Further and similar studies may show that various strains of Treponema. pallidum may possess selective tissue affinities and thereby explain the early development of lesions in the central nervous, cardiovascular, and cutaneous systems of different persons. According to the investigations of Rosenow4 various bacteria, and particularly streptococci, exhibit extreme degrees of tissue affinity and produce various constant and distinct lesions in rabbits after inoculation by various routes. Usually the normal defensive factors of the body are sufficient to overwhelm one or a few bacteria unless they are especially virulent. When an inter current or chronic disease, malnutrition, or injury renders the host more susceptible than normal, fewer bacteria than would otherwise be required may successfully infect the body. Also with true parasites, or those with well-marked aggressiveness, such as the anthrax bacillus, a few may be sufficient, if they reach the circulating fluids, to produce infection. Thus Webb, Williams, and Barbor1 have found that one anthrax bacillus was sufficient to infect a white mouse, and as few as 20 tubercle bacilli were sufficient in one instance to infect a guinea-pig. Likewise Kolmer, Schamberg, and Raiziss2 have found in experimental trypanosomiasis that the infection of white rats by intraperitoneal injection with varying numbers of trypanosomes, counted after the method of Kolmer,3 greatly modifies the time of appearance of trypanosomes in the peripheral blood and the duration of life, and has an important bearing upon studies in the chemotherapy of experimental trypanosomiasis. Park has directed attention to the fact that when bacteria are transplanted from culture to culture, under supposedly favorable conditions, many of them die; it is highly probable that when they are transplanted to an environment that is likely to be unfavorable, as are the body tissues with various defensive mechanisms, many more must die. This is an important point to bear in mind in attempting to correlate experimental results with the natural cause of an infectious disease. In the laboratory we reproduce disease experiment ally, by the immediate injection of millions of bacteria, whereas in nature there is rarely any such immediate overwhelming of the tissues. For example, pneumonia may be produced experimentally in dogs by the injection of a large number of virulent pneumococci directly and at once into the bronchi, yielding a positive result with a microorganism which, under natural conditions and in smaller numbers, would be relatively innocuous for the animal under observation. GENERAL SUSCEPTIBILITY IN RELATION TO INFECTION Under normal conditions the body-cells of a host will invariably offer some resistance to invasion and infection by pathogenic microorganisms. When, however, any condition that depresses or diminishes general physiologic activity and vitality exists, the host may be unable Predisposition may be inherited or acquired. Inherited predisposition may be — -(a) Specific, or species susceptibility, as, e. g., dogs to distemper; cattle to contagious pleuropneumonia; hogs to hog cholera; man to gonorrhea; chancroids, acute exanthemata, typhoid fever, etc. (6) Racial, as Eskimos to measles and syphilis, ordinary sheep to anthrax, whereas Algerian sheep are immune, etc. Racial susceptibility is frequently but a lack of acquired immunity; for instance, measles, syphilis, gonorrhea, and other diseases brought by settlers to foreign peoples among whom these diseases were previously unknown, find them peculiarly susceptible and the diseases unusually virulent, (c) Familial, i. e., members of a family may, through generations, be unusually susceptible to scarlet fever, tuberculosis, rheumatism, rheumatoid arthritis, metabolic disturbances, etc. (d) Individual predisposition, which depends principally upon sex, age, and peculiar tissue susceptibility. Thus infants are especially prone to contract certain infections on account of the immature development of the body-cells, and this susceptibility to infection is further influenced by acquired factors, chiefly malnutrition. On the other hand, very young children enjoy an immunity to several infections, such as typhoid fever, scarlet fever, and even diphtheria, probably due, as Abbott has suggested, to the fact that pathogenic substances that may set up molecular and destructive disturbances in the poorly developed cell have but little effect upon the more inert protoplasm of the immature cell, and that if certain bacteria gain admission to the tissues, the cells may destroy them, their toxins not combining with the molecular side-chains, and, as a consequence, not injuring or interfering with the cell functions. Acquired susceptibility bears a more important relation to infection, and may be due to various factors, most of which lead to a state of reduced vitality, normal physiologic processes being impaired to a greater or less degree. (a) Overwork or overstrain leads to general or local predisposition to disease. Those engaged in hard labor, mental or physical, which involves late hours and inadequate periods of rest and recreation, frequently associated with inadequate nutrition and foul air, are likely to succumb to tuberculosis, typhoid fever, pneumonia, etc. The influence of overstrain on acute infections has been shown experimentally by Charrin and Roger,1 who found that white rats naturally immune to anthrax became quite susceptible after being compelled 1 Compt. rend. Soc. de Biol. de Paris, January 24, 1890. to turn a revolving wheel until exhausted before they were inoculated; similarly of four guinea-pigs who were placed in a cage so constructed that they were forced to keep moving for one or two days three died in from two to nine days after the experiment. Smears and cultures made from the livers, spleens, and blood gave positive results. (6) Previous infection with the same or another infectious disease may predispose the individual to renewed infection. Thus some infections, such as erysipelas, furunculosis, acute rheumatism, pneumonia, and influenza, not only fail to leave the body-cells immune, but actually predispose to second attacks. Whether the microorganisms of these diseases are not all destroyed, but are retained in the system and become active when the general vitality is lowered, or whether a new infection occurs, is not definitely known, and probably either may occur. One attack of an infectious disease may weaken the tissues and render them susceptible to an infection of a different nature. Thus the acute exanthemata may follow one another, and tuberculosis may supervene upon any of them. (c) Malnutrition exerts some effect on the resistance to infection. Thus the terrible epidemics of plague, cholera, typhus fever, and typhoid fever which have followed in the wake of famines in Europe and Asia during the past centuries are examples of the influence of malnutrition as a factor in predisposing to disease. The tendency of marasrriatic infants to develop enterocolitis, thrush, bronchopneumonia, and other infections, and of scorbutics to local infections of the mouth, illustrates the influence of insufficient food in decreasing the resistance to disease. Here may also be included local malnutrition, such as loss of nerve or blood supply, predisposing to local infection, especially with pyogenic microorganisms. (d) Diet produces some variation in the resisting powers to infection. For example, the ordinary wild rat is not susceptible to anthrax unless it is fed for a week or more on coarse dry food, when it become susceptible. Here, of course, malnutrition may come in intimate relationship with diet, as an inefficient diet may greatly lower the general resistance. The influence of diet is particularly noticeable from the fact that the diseases of carnivorous animals are not the same as those that affect herbivorous animals, and that each class is frequently immune to some of the diseases that attack the other. (e) Intoxications of various kinds predispose to infections. Thus it is a common clinical observation that excessive indulgence in alcoholic beverages predisposes to infections, notably pneumonia. Abbott1 has DEFENSIVE MECHANISM IN RELATION TO INFECTION 103 demonstrated experimentally that the daily administration, to rabbits, of 5 to 10 c.c. of alcohol introduced into the stomach by a tube, renders these animals more susceptible to infection with Streptococcus pyogenes and Bacillus coli. Wagner, Leo, and Platania have also found animals that under the influence of chloral, phloridzin, alcohol, and curare are more susceptible to infection. (/) Exposure to cold and wet frequently lowers the resistance of man and other warm-blooded animals to infection. The influence of these factors, well illustrated in the etiology of " colds" and pneumonia, is not without experimental foundation. Thus Pasteur found that fowls, which are naturally immune to anthrax, are readily infected if they are inoculated after their body temperature has been reduced by a cold bath. Conversely, Gibier1 has shown that frogs, which are also naturally immune to anthrax, are readily infected if their temperature is previously elevated and maintained at 37° C. (</) Trauma and morbid conditions in general may predispose to infection. Thus injuries reduce the local resistance and facilitate local infections that vary with the severity and extent of the trauma. The increased susceptibility of injured joints and pneumonic lungs to tuberculosis; the frequent and oftentimes extensive streptococcus infection accompanying scarlet fever and smallpox; the increased susceptibility of diabetics to furunculosis and local gangrenous lesions of the skin — all show the increased susceptibility of individuals already injured or diseased to infection. After bacterial invasion has occurred, the question of whether or not the microorganism can overcome the defensive forces of the host and prove pathogenic may depend to some extent upon the peculiar defensive factors of the invading bacteria against the offensive mechanism of the host, aside from their toxins or other distinctly offensive forces. Morphologic and Physiologic Changes of the Microorganisms. — For example, capsule formation or thickening of the ectoplasm of certain bacteria is evidence of their increased powers of resistance against the opposing forces of the host. The capsule may be quickly lost when the microorganism is cultivated on artificial media-, and its virulence be correspondingly lowered, but by repeated animal inoculations a race of capsulated organisms with increased virulence is produced, explaining in a way the mechanism of animal passage in raising the virulence of a given organism. This, however, is not invariable, and, indeed, may act in a contrary manner, as the passage of smallpox virus through heifers attenuates and modifies instead of increasing its virulence. Aggressins. — The microorganism may actively secrete a material that overwhelms the defensive forces of the host. This phase of the subject has been studied exclusively by Bail, who sought to prove that the question of pathogenicity of a microorganism is dependent upon its ability to secrete substances that are able to paralyze the protective forces of the host, especially the leukocytes. These substances are called " aggressins, " and they were distinguished by the fact that they were formed by living bacteria and only in the living body. In support of this theory Bail was able to show that substances are present in the exudates of fatal infections, which, when injected in small quantities into another animal with sublethal doses of the microorganism, would cause a rapidly fatal infection. Later Wassermann and Citron showed that " artificial aggressins" could be prepared by autolyzing bacteria in water or serum. While the subject of aggressins is still unsettled, there is strong evidence to show that they are the endotoxins liberated by the breaking-up of the microorganism. The well-known statement of Metchnikoff, that a particular virulent microorganism is not so readily taken up by leukocytes as is an avirulent strain, may be explained by the fact that the microorganism, in its virulent parasitic state, secretes substances that repel the phagocytes, neutralize the opsonins, or form actual leukocytic toxins. This action may be due to liberated endotoxins, or, as Bail claims, to specific secretory substances of the bacterium — the aggressins — specifically formed and liberated by the microorganism for protection against the host. Hypothesis of Welch. — Not entirely foreign to this subject is the very interesting hypothesis of Welch. A bacterium may not only produce substances directly inimical to the defensive forces of the host, but it may actually immunize itself against these defensive powers. " Looked at from the point of view of the bacterium, as well as from that of the animal host, according to the hypothesis advanced, the struggle between the bacteria and the body-cells in infections may be concerned as an immunizing contest in which each participant is stimulated by its opponent to the production of cytotoxins hostile to each other, and thereby endeavors to make itself immune against its antagonist." typhoid fever, the typhoid bacillus resists agglutination, whereas it becomes easily agglutinable after a period of artificial cultivation. It may be assumed that, when active, the bacillus as an infecting agent gradually became more resistant against the agglutinating properties of the patient's serum, and that, when grown on artificial media, it loses this resistance by being removed from the stimulating influence of the infected body. This hypothesis, however, would go a step further in assuming the possibility of the receptors of the invading bacteria anchoring certain constituents of our body-fluids, and being stimulated to the production of various cytotoxins, which attack the leukocytes, erythrocytes, nervecells, liver, kidney, etc. In other words, each bacterium may be conceived as being composed of a central atom group with numerous sidechains, just as Ehrlich conceived the hypothetic structure of body-cells, and that these side-chains, primarily present for the purpose of anchoring food material, may likewise anchor various pathogenic animal substances, with the production of substances acting as antibodies to the opposing forces of the host. Welch assumed that these bodies were of the nature of amboceptors, which may become complemented by bacterial complement or by endocomplements of the tissue-cells; this is of secondary importance, and there is no reason why they may not be of different structure, and similar to all three orders of antibodies produced by body-cells according to Ehrlich's side-chain theory of immunity. This hypothesis may possibly explain certain instances of so-called species and organ virulence, whereby the virulence of an organism artificially increased by repeated passage through animals of the same species, does not manifest this increased virulence for animals of different species. If, for example, the virulence of the chicken cholera bacillus is increased by repeated passage through the chicken, the increase of virulence affects this animal, but does not affect the guinea-pig. Certain organs may likewise be subject to a similar selective virulence, if the increase in virulence has been induced by the specific intervention of those organs, and this selective virulence shows itself, irrespective of the manner in which the infection was produced. That virulence of this order is playing an important role in the processes of infection is a theory supported by the discovery that different strains of the same species of bacteria are found to produce characteristic lesions, and while this affinity for a certain organ may be natural and inherent, there can be no doubt that it may also be experimentally induced and acquired. For example, according to Rosenow, a certain another, gastric ulcer, etc. This remarkable species and organ specificity may be due to the fact that the bacteria of a particular culture have been immunized against defensive forces of a particular animal host or a certain organ of the host, so that, when introduced, they thrive as a result of their special and acquired offensive forces. On the other hand, the specificity may be due to the fact that the bacteria have been accustomed to a certain nutriment furnished by a particular species or organ, and that they cannot thrive unless they receive this special nutriment, and, as a result, the species or organ fulfilling this requirement will become the special seat of infection (Simon) . Several different microorganisms may produce infection at the same time, or one may follow the other or others and produce secondary infection. The combined effects, upon the tissues of the host, of the products and action of two or more varieties of pathogenic bacteria, and also of the influence of these different forms on each other, are of great importance in the production of disease. The metabolic products of one bacteria may neutralize or accelerate the action of an associated species, or combine to form a new substance entirely different from its antecedents. Thus pyogenic cocci affect anthrax bacilli in an injurious manner; on the other hand, aerobic bacteria accelerate or make possible the growth of anaerobes by absorbing uncombined oxygen. Tetanus bacilli will not grow outside of the body in the presence of oxygen unless aerobic bacteria are associated with them; not infrequently tetanus bacilli and their spores would not develop in wounds were it not for the presence of the aerobic bacteria introduced with them; this factor is of much importance, especially in tetanus produced by cowpox vaccine, where, through careless treatment of the lesion, both tetanus bacilli and pyogenic cocci are admitted to the wround. ment of streptococci. Generally all infections of mucous membranes are mixed infections. Numerous bacteria are present upon the mucosa of the air-passages and gastro-intestinal tract; these are usually harmless, unless the resistance of the host is lowered in some manner, in which case not only one SUMMARY 107 but several varieties of these bacteria invade the tissues and cause infection. When one pathogenic microorganism, such as the typhoid bacillus, has caused the primary infection, because of the local and general conditions of lowered vitality of the tissues, these otherwise saprophytic bacilli tend to intensify the infection. Blood infections, on the other hand, are usually due to one form of bacteria, and even when two or more varieties are introduced, only one, as a rule, is capable of surviving and developing. The products of certain bacteria, on the other hand, may immunize the host against infection with other bacteria, for, as shown by Pasteur, attenuated chicken-cholera cultures may produce immunity against anthrax. In the intestine harmless varieties of bacteria may be made to crowd out more dangerous ones; this is exemplified by the ingestion of soured milk which contains lactic-acid bacteria, as advocated by Metchnikoff. From what has been said it is clear that infection differs from mere surface contamination, and cannot be said to occur until the invading bacteria have reached the deeper tissues, or a point where they may grow and multiply. The surface epithelium and various secretions offer the most potent local obstacles to infection, but even when these barriers are broken down, the invaders may not survive the onslaughts of various protective agencies of the host. In order to withstand and overcome these attacks, the bacterium may undergo certain morphologic and physiologic changes, and actively secrete a substance that is inimical to the defensive forces of the host, or immunize itself against these forces. Thus a certain species of bacteria may become selectively fortified or immunized against a certain host or organ of that host, and show a specific affinity for producing infection of a certain animal or a particular organ. When the bacterium has overcome the defensive forces of a host, it may, by the formation and action of exogenous and endogenous toxins, bacterial proteins, mechanical blocking of vessels, or formation of ptomains, produce disease. These various factors will be considered in greater detail in the following chapter. PRODUCTION OF DISEASE WHEN pathogenic microorganisms have reached the deeper tissues and multiplied, infection has occurred, but, as previously stated, tissue changes of sufficient extent to produce definite lesions and symptoms of disease may or may not result, depending upon whether or not the defensive forces of the host are able to overcome the invaders or are overcome by them. If the latter has occurred, and the invading bacterium is firmly established in its host, the question of how the bacterium and its products cause disease, that is, the mechanism of the production of an infectious disease, arises for consideration. The subject is, indeed, quite complex. Although the etiologic relationship of a large number of pathogenic bacteria to definite pathologic changes and conditions has been proved by the regularity with which they are found in the diseased tissues, and in many instances has been corroborated by animal experimentation, yet the ways and means by which these bacteria produce disease are quite varied, and are seldom dependent upon one product of bacterial activity. For example, diphtheria and tetanus are apparently simple infections, being caused by soluble toxins secreted by the respective bacilli. There are many factors concerning the action of these toxins, however, which are not as yet understood. Again, the lesions of staphylococcus and other pyogenic infections are probably due to the activities of soluble toxins, endotoxins, and the protein of the bacterial bodies. All three of these factors are probably concerned in the production of typhoid fever and cholera, whereas the symptoms of sleeping sickness are due in part to blocking of a small but physiologically important vessel in the brain by trypanosomes, with the absorption, at the same time, of toxins and disintegration products. To these may be added the effects of other biologic activities of the bacteria in living or dead tissues, such as the production of gas from carbohydrates, proteins, etc., in Bacillus aerogenes capsulatus infection. Each infection, therefore, must be regarded as largely a law unto itself, so that all that will be included within the scope of this book will be the mention and illustration of what are zoa produce disease, omitting a description of each disease in detail. In the great majority of instances disease is produced as the result of chemical substances generated by the metabolic processes of bacteria. Animal parasites and certain bacteria, such as that of anthrax, may do harm mechanically by forming capillary emboli; but, as stated, bacteria, as a rule, produce their effects chiefly through chemical means. Accordingly, bacteria may give rise to infection and disease through the following agencies : lesions. 5. Ptomains, which are the secondary products of decomposition of the media upon which the bacteria are growing; these may be absorbed and produce symptoms of intoxication. 6. Mechanical action of bacteria, whereby certain symptoms or lesions may be due to the blocking of small but physiologically important vessels with emboli of bacteria, in addition to the effects of mechanical irritation. TOXINS Nomenclature. — Of all the various means whereby bacteria produce disease, none possesses so much importance as the poisonous substances, known as toxins, elaborated by the metabolic activities of the microorganisms. A few classes of bacteria secrete this poisonous principle directly into the tissues or artificial culture-media in which they are growing, and hence are known as soluble, exogenous, extracellular, or true toxins. Other bacteria retain most of their toxins within the bacterial cell, and for this reason are called endotoxins, or intracellular toxins; these are liberated upon the disintegration of the bacteria by various mechanical, physical, or chemical means. By common consent the term " toxin" is applied to the soluble or true toxins, such as those of diphtheria and tetanus, and hence the term, when used without further qualifications, may be considered to refer to toxins of this class. Aside from bacterial toxins, characteristic poisons are also produced by certain of the higher plants (phytotoxins) and animals (zootoxins), and although few are of medical interest, their study has thrown considerable light on the phenomena of toxin-antitoxin immunity. Extracellular Bacterial Toxins. — Definition. — Bacterial toxins may be defined as poisonous products produced by bacteria in both living tissues and artificial culture-media. The symptoms resulting from their activity appear after a certain period of incubation, and all are capable of stimulating the production of specific antitoxins. They represent the chief poisonous product of bacteria, and are mainly responsible for the symptoms of infection caused by the specific bacteria that have produced them. extremely labile, and susceptible to the action of heat, light, age, etc.; consequently an absolutely pure toxin is practically unknown. Oxygen, even as it occurs in the air, is harmful; all oxidizing agents, including the oxidizing enzymes, quickly destroy them, and Pitini1 has ascribed the harmful effects of toxins to their power of reducing the oxidizing capacity of the tissues. Some substances seem to attack only the toxophore portion of the toxin molecule, e. g., iodin and carbon disulphid (Ehrlich). In the preparation of antitoxin, the first doses of toxin are frequently modified by adding a chemical of this nature. According to Gerhartz 2 z-rays tend to weaken the toxins. Because of their great lability, the toxins do not lend themselves to accurate chemical analysis. Our knowledge of them has been gained largely through a study of the lesions and symptoms produced by injecting the toxins into susceptible animals. They are, so far as known, uncrystallizable and thereby differ from ptomains; they are soluble in water and dialyzable through thin but not thick membranes. They are precipitated along with peptones by alcohol, and also by ammonium sulphate. The toxins are all poisonous, but in order to exert their toxic effect they must enter into chemical combination with cells; hence there is a necessary period of incubation before symptoms of their activity appear. 1 Biochem. Zeit., 1910, 25, 257. 2 Berl. klin. Woch., 1909, 46, 1800. Most bacterial toxins are not absorbed from the intestine (botulinus toxin excepted), and when introduced into the gastro-intestinal tract, they are usually unable to produce symptoms and are quickly destroyed. An essential property of a toxin lies in the fact that we can immunize a subject against it, and are able to demonstrate the presence of antitoxin within the serum of the immunized animal. Chemical Properties of Soluble Toxins. — As has just been stated, the exact chemical nature of toxins is unknown. This is due principally to the fact that pure toxins of bacteria are rarely obtainable, except in conjunction with their associated products, such as lysins, pigments, acids, etc., as well as to the great lability of the toxins. A summary of the results of researches into the chemical nature of toxins would indicate that they are tcJxalbumins, albumoses or allied to the albumoses. Certain investigators have reported that very active toxins obtained by purification processes did not give the protein reactions, yet toxins are digested by proteolytic ferments, and, like proteins, are precipitated by nucleic acid (Kossel). According to Field and Teague,1 the toxins act like electropositive colloids, but diffuse faster than do proteins. Our present knowledge of the chemistry of the true toxins has been expressed thus by Oppenheimer: "We must be contented to assume that they are large molecular complexes, probably related to the proteins, corresponding to them in certain properties, but standing even nearer to the equally mysterious enzymes with whose properties they show the most extended analogies both in their reactions and in their activities." Precipitation of the Extracellular Toxins. — After the toxin has been secured by filtration, crystals of ammonium sulphate are added in large excess over the saturation point, and the whole kept at 37° C. for eighteen hours. The toxin is precipitated and rises to the surface along with the albumoses and peptones. This is skimmed off and quickly dried with an electric fan and cold air. The residue is ground into a fine powder and stored in vacuum tubes kept at a low temperature and in a dark place. During this process there may be considerable deterioration and especially with tetanus toxin. Banzhaf has obtained highly potent and dried diphtheria toxin by slightly acidulating the toxin broth and adding absolute ethyl alcohol up to 65 per cent.; after an hour or two the slight precipitate is filtered off, quickly dried, and kept in ampules. Structure of Toxins. — According to Ehrlich, the toxin molecule consists of a main central atom or radical, with a large number of organic side-chains grouped, as in other organic compounds, about this main radical. Each of the side* or lateral arms is composed of two portions — one, the haptophore group, which has a chemical affinity for certain chemical constituents of the tissues of susceptible animals, and the other, the injury-producing portion, called the toxophore group. (See Fig. 40.) An animal is susceptible to a toxin only when its cells contain substances that possess a chemical affinity for the haptophore group of the toxin, and also substances susceptible to the toxic action of the toxophore group. The toxophore group is far more unstable and susceptible to deleterious influences than is the haptophore portion. When the molecule has lost the toxophore radical, it is known as a toxoid, which is still capable of uniting with the side arms of cells but is devoid of toxic action. Nature of Toxins. — It has been abundantly demonstrated that toxins are colloids, and in many respects bear a close resemblance to enzymes. (See p. 254.) The toxins are synthetic products of bacterial activity. They are of absolutely specific nature, and in this manner differ from ptomains, which are cleavage products from the medium upon which the bacteria have been grown. Furthermore, ptomains of similar properties may be produced by several different kinds of bacteria, and accordingly are non-specific in nature. Toxins, like ferments, can give rise to antibodies, whereas ptomains cannot produce them. The extracellular or soluble toxins differ from the intracellular toxins in that they are more easily diffused throughout the animal juices, and that their diffusion occurs independently of the invasiveness of the bacteria, so that comparatively few microorganisms growing at some unimportant focus, and causing but slight local lesions, may be able to give rise to profound general intoxication. This is well illustrated in diphtheria, where the local lesion in the throat may be quite small, and in tetanus, where it may indeed be undiscoverable — yet either, through the action of their toxins on special tissues, may cause profound intoxication and death. Selective Action of Toxins. — Extensive studies of the toxins of diphtheria and tetanus and of cobra venom have shown that they are quite complex, and are usually composed of two or more distinct and separate toxins possessing different pathogenic properties, although one of these may predominate in producing symptoms. All infections with the group of true toxin-producing bacteria manifest certain non-specific symptoms of general intoxication, namely, fever, headache, malaise, prostration, etc.; but the typical symptoms of these diseases are due to the remarkable selective action of the toxins upon certain cells or organs, dependent upon the ability, chemical, physical, or both, of the toxin to combine with these specific cells. For SPECIAL PROPERTIES OF THE PRINCIPAL TOXINS 113 example, tetanus toxin contains tetanospasmin, that has a special affinity for nervous tissue; and tetanolysin, a poison that has a selective affinity for erythrocytes and is hemotoxic. Ehrlich has shown that these are really different toxins, and not one toxin with a two-fold function, even the antitoxins of the two being different. Similarly, the general symptoms and necroses of diphtheria are attributed to the main toxin of the bacillus, and the nerve lesions and paralyses to a secondary but distinct secretory product known as toxon. This latter view of Ehrlich's, however, is much disputed, many investigators believing that toxon represents a degenerated or modified form of the one toxin. The special affinities of toxins for certain tissues have analogies among the poisons of higher plant life, as, for example, strychnin has a similar selective affinity and is said to be specific in its action upon the motor cells. The venom of various serpents, especially that of the cobra, has specific action: the erythrocytes of various animals are readily attacked by it, and the cells of the respiratory center are apparently profoundly affected. Aside from the special effects of the toxins upon certain cells and tissues, it must be remembered that toxins may involve the body-cells in general, and particularly those of the parenchymatous organs, such as the kidneys, heart, and liver, causing coagulation of the protoplasm (cloudy swelling) and final dissolution. The harm brought about by the toxins or toxic products of the pyogenic group of microorganisms, for instance, acts mainly in this manner. SPECIAL PROPERTIES OF THE PRINCIPAL TOXINS 1. Diphtheria Toxin. — Diphtheria bacilli vary considerably, both in tissues and in artificial culture media, in the quantity of toxin secreted; thus in bouillon large amounts are seldom found in less than from seven to fourteen days. The action of the toxin is dependent upon the dosage, and a certain period of time must always elapse before the symptoms appear, the minimum being about one day. Large doses may shorten this period of incubation, but cannot diminish it below a certain limit. The lesion of diphtheria is practically always local, and is usually situated on the mucous membrane of the upper air-passages. It is characterized by the formation of a pearly white membrane that is adherent to the underlying edematous tissues. The toxin produces necrosis of the surface epithelium, and the product, together with fibrin and leukocytes, constitutes the membranous exudate. From this focus toxin is absorbed by the lymphatics and blood-stream, and distributed throughout the body, the bacilli being rarely found in the blood or internal organs. Later the effects of toxin intoxication are shown by paralyses of certain motor nerves and ganglia, particularly those of the palate and heart. When a guinea-pig receives a subcutaneous inoculation with diphtheria toxin, a typical hemorrhagic gelatinous edema develops at the site of inoculation (Fig. 36). Upon opening the abdominal cavity one finds but little peritoneal exudate, but the vessels of the mesentery are injected and the adrenal glands show characteristic acute hyperemia (Figs. 37 and 38). Bloody pericardial and pleural exudates will be found in the thorax, and solidified areas in the lungs. Guinea-pigs surviving a dose of toxin may, after two or four weeks, begin to show paralysis of the hind and then of the fore extremities, a condition analogous to the post-diphtheric paralysis occurring in man and ascribed to the effects of toxon. Method of Testing the Virulence and Toxicity of Diphtheria Bacilli. — Young guinea-pigs weighing from 250 to 300 grams are quite susceptible to diphtheria toxin, and are used in determining the strength of a toxin and in standardizing antitoxin. The test may be of great value in the management of convalescent and " carrier" cases of diphtheria, harboring bacilli in the upper air-passages, in determining whether the microorganisms are dangerous or merely harmless non-pathogenic saprophytes. It is practically impossible, from the morphology of the organism alone, to decide whether or not a given culture is dangerous, and prolonged quarantine may not only be irksome and inconvenient, but, if the organisms are proved to be harmless, it is unnecessary as well. To be reliable, however, such a test must be carried out very carefully. In the case of a highly virulent culture, the mere introduction of a few organisms beneath the skin will suffice to demonstrate their dangerous character, but with cultures only slightly virulent, more care is necessary, for although the patient may show no ill effects as a result of the presence of the bacilli, in the throat of another and less immune individual they may be highly dangerous. has proved of distinct value : 1. Make a culture of the part harboring the bacilli on a tube of Loffler serum medium. Incubate at 35° C. for from eighteen to twenty-four hours; prepare a smear and stain with Loffler's methylene-blue. If diphtheria bacilli are present, FIG. 36.— ABDOMINAL WALL OF GUINEA-PIG SHOWING DIPHTHERIC EDEMA. Shows abdominal wall of a guinea-pig forty-eight hours after subcutaneous injection with 2 c.c. of a seventy-two-hour bouillon culture of a diphtheria bacillus isolated from the throat of a diphtheria convalescent. alkaline, with several different colonies. 4. Incubate at 35° C. for three days, keeping the tube in a slanted position in order to give the culture as much oxygen as possible. If a good growth does not appear in twenty-four hours, transplant to another tube of bouillon until the bacilli have been "educated" to grow on the medium. 5. Examine for purity. Select a 250- to 300-gram guinea-pig and inject 2 c.c. of the unfiltered culture in the median abdominal line. Animals over the weight specified are more resistant and less reliable for the test. The unfiltered culture is used, since toxin is but one element of the disease-producing power of diphtheria bacilli, and toxin production in bouillon may not be a true index of the toxin production in mucous membranes. 7. After death perform a careful autopsy. Make cultures of the edematous area, peritoneum, and heart blood. Diphtheria bacilli may be found in the edematous fluid, but will rarely be found in the peritoneum or in the blood. Observe whether acute hyperemia of the suprarenal glands is present (Figs. 37 and 38). 8. Not infrequently animds showing mild or even an absence of the symptoms of toxemia develop paralysis cf the hind quarters two or three weeks later. According to Ehrlich, this paralysis is due to the action of "toxon, " a toxic substance secreted by the bacillus or, as believed by others, a modified form of toxin. 9. To prove that diphtheria was the cause of the toxemia or death mix 2 c.c. of the culture in a test-tube with 1 c.c. of diphtheria antitoxin (500 units). After standing aside for an hour at room temperature, inject the mixture subcutaneously in the median abdominal line of a 250 to 300 gram guinea-pig. Symptoms of toxemia do not develop. In a comparative study of the above and other methods Kolmer and Moshage1 found that washing off a pure culture from a slant of Loeffler's blood-serum media with 10 c.c. of sterile salt solution, emulsifying and injecting 4 c.c. subcutaneously in the medium abdominal line of a 250- to 300-gram guinea-pig, yielded equally delicate results. The intracutaneous method of Neisser which has also been advocated by Zingher and Soletsky,2 while being more economical in that 2 pigs suffice for 4 or even 6 tests, was found to yield somewhat indefinite reactions with bacilli of low virulence. Standardizing Diphtheria Toxin. — The strength of a diphtheria toxin is estimated by injecting subcutaneously a series of guinea-pigs weighing approximately 250 grams, with decreasing amounts of toxin. How many dilutions will be necessary it is impossible to state; for exact results several pigs of the same weight should be inoculated with the same dose, and the effects should show various gradations, dependent upon the size of the successive doses. In order to obtain a uniform method for estimating the strength of a diphtheria toxin and thus obtain comparative values, a standard unit has been adopted, consisting of the smallest amount of toxin that will kill a healthy guinea-pig weighing about 250 grams in from four to five days. This is known as the minimum lethal dose, or dosis lethalis minimus. The technic used for determining this dose is given in the chapter on Antitoxins, p. 241. A quick and accurate method for estimating the amount of diphtheria toxin present in the body-fluids of a diphtheric patient would be of value in controlling the antitoxin treatment of this infection. At present the amount of antitoxin administered is regulated according to the clinical condition of the patient. Uffenheimer has used a method for determining the presence of toxin, consisting in injecting intraperitoneally a 250-gram guinea-pig with 0.1 to 0.4 c.c. of the patient's serum, diluted with 2 to 4 c.c. of salt solution. The presence of a distinct doughy edema of the abdominal cavity after seventeen to twentyfour hours indicates the presence of diphtheria toxin, an observation that may be confirmed by making an autopsy at the end of forty-eight hours. The diagnostic value of this method has not been adequately established : it is doubtful if it yields any information other than is more readily gained by making a good cultural examination of the patient, and it does not aid in the estimation of the quantity of toxin, which is the result most desired. Diphtheria toxins have been classified into three groups, depending upon the degree of avidity for antitoxin they display, viz., prototoxin, deuterotoxin, and tritotoxin. Each of these toxin groups may, in whole or in part, be converted into toxoids. The prototoxin has a greater affinity for the antitoxin than has the deuterotoxin, and the deuterotoxin has a greater affinity for the antitoxin than has the tritotoxin. The same relation is apparent with the three toxoids, which are not poisonous, but which have the same power of combining with antitoxin as have the toxins from which they take their origin. In standardizing antitoxin, it is found in general that with a perfectly fresh toxin a certain amount of antitoxin will just neutralize a definite amount of toxin. If older toxin is used, it is found that the toxin has lost about one-half its toxic power, but retains its initial power for neutralizing antitoxin. Ehrlich explained this by showing that the diphtheria toxin molecule is composed of two groups — one the carrier of the toxic qualities, the toxophore group, which is quite labile; the other uniting the whole molecule with antitoxin, being capable of neu- tralizing it, and characterized by its stability. The toxophore group being destroyed as in old toxin, the poison loses its toxic qualities, birt retains its power to bind antitoxin. This modified toxin or non-poisonous diphtheria toxin has been designated by Ehrlich "diphtheria toxoid." 2. Tetanus Toxin. — Of all bacteria classed as true toxin producers, none possesses greater toxicity than does the tetanus bacillus. The number of organisms producing sufficient toxin to cause a fatal infection may be so small that careful anaerobic cultures made from the local lesion of infection, together with injection of the wound secretions into white mice, may fail to disclose the presence of tetanus bacilli. According to Ehrlich, tetanus toxin is composed of two separate and distinct substances — (1) Tetanospasmin, a neurotoxin, which is very labile and responsible for the severe symptoms of the infection; (2) tetanolysin, a hemotoxin, which is more stable and destructive for erythrocytes. Tetanus toxin is prepared by cultivating the bacillus in bouillon under strict anaerobic conditions. Since tetanospasmin is so susceptible to the influence of heat, age, and even light, the toxin is best preserved in a dry form. The standard of tetanus toxin consists of 100 minimal lethal doses of a precipitated and dried toxin, preserved at the Hygienic Laboratory of the Public Health and Marine-Hospital Service. If susceptible animals, such as mice or guinea-pigs, are injected subcutaneously or intravenously with tetanus toxin, they begin to manifest symptoms after a certain period; these are due to the action of tetanospasmin upon motor nerve-cells, and are characterized by hypersensitiveness, clonic convulsions, and rigidity of the muscles. In man the symptoms of tetanus are similar to those in the animal, the spasm starting quite regularly in the muscles of the lower jaw. Experiments by Wassermann and Takaki have demonstrated that an especially close affinity exists between tetanus toxin and certain structures, particularly that of the central nervous system. Most writers agree that the toxin reaches these tissues largely by way of the nerve-paths. 3. Botulism Toxin. — This poison is generated by the Bacillus botulinus, first isolated, by Van Ermengem in 1896, from a ham during an epidemic of meat poisoning. It is the cause of a type of meat and sausage poisoning called botulism, more frequent in those countries where raw meat is eaten, and frequently confused with "ptomain poisoning." It is quite labile. Symptoms of botulism appear only after a definite period of incubation, which varies from twenty-four to forty-eight hours. In contradistinction to the meat poisonings produced by other organisms,* those due to Bacillus botulinus may show few or no symptoms directly referable to the intestinal tract, the chief symptoms being due to toxic interference with the cranial nerves: loss of accommodation, ptosis, dilated pupils, aphonia, dysphagia, and hypersecretion of mucus from the mouth and nose. Guinea-pigs are quite susceptible, and may be infected by way of the mouth. The symptoms of intoxication usually follow in twenty-four hours, and are characterized by motor paralysis, dyspnea, and hypersecretion of mucus from the nose and mouth. 4. Dysentery Toxin. — The distinct types of dysentery bacilli vary exceedingly in their powers to produce toxins, the strongest poisons being produced with bacilli of the Shiga-Kruse variety, less regularly active ones, with bacilli of the Flexner type. Investigations have shown quite conclusively that dysentery itself is a true toxemia, its symptoms being referable to the absorption of the toxins of the bacillus from the intestine. Flexner, who has studied this subject with great care, believes it probable that most of the pathologic lesions occurring in the intestinal canal are referable to the excretion of dysentery toxin, rather than to the direct local action of the bacilli. The action of the dysentery toxin upon animals is very characteristic, and throws much light upon the disease in man. Intravenous injection of the toxin in rabbits is followed by marked diarrhea, rapid fall in temperature, respiratory embarrassment, and terminal paralysis. Upon autopsy the intestinal mucosa, especially that of the cecum and colon, shows marked inflammatory involvement, supporting Flexner's observation of the necrotic action of excreted toxin. Dysentery bacilli also produce an endotoxin, and poisonous substances are easily obtained by extracting the bacilli themselves or by filtration of properly prepared bouillon cultures. The toxin is fairly stable, and well preserved under toluol in the refrigerator. An anti-hemotoxin that counteracts the effects of the toxin may be produced experimentally, and in human staphylococcus infections the demonstration of such antihemotoxic substances in the blood-serum may be of aid in making the diagnosis of staphylococcus infections. This antistaphylolysin may be found normally in small amounts in the serum of man and horse, and when anti-hemotoxic tests with human serum are made, a normal control should always be included. Antileukocidins have also been produced, but are not of practical importance. The hemotoxin is readily formed in cultures of staphylococci; roughly, the amount produced depends upon the virulence of the culture. In human cases of staphylococcus infections this toxin produces hemolysis in vivo, and is partly responsible for the grave anemia that is frequently present. 6. Streptolysin. — The grave systemic symptoms that so frequently accompany slight streptococcus lesions are strong indications that these microorganisms produce a powerful diffusible poison, although extensive researches into the nature of these poisons have not given us any clear understanding of the subject. Streptococci may yield soluble toxins that, when administered to guinea-pigs, produce rapid collapse and death. While these toxins are not comparable in potency to the soluble toxins of diphtheria and tetanus, they have, nevertheless, been differentiated from the endotoxins contained within the cell-bodies, and have been found to possess less toxicity. Beside these toxins, some streptococci produce a hemolysin which may be conveniently observed by cultivation of the organisms upon blood-agar plates. This hemotoxin is partly responsible for the sanguineous character of a streptococcus exudate. As has previously been mentioned, the power of forming toxins is not confined to bacteria alone. There is a class of higher plants and animals that produces characteristic poisons against which immunization can be undertaken and an antitoxic serum obtained. Those of most interest medically are pollen toxin and snake poison. The most important plant toxins (phytotoxins) are ricin, abrin, crotin, and pollen. All possess more or less toxic qualities; the first three either agglutinate or hemolyze the corpuscles of certain animals. Antitoxic serums have been prepared that will neutralize the respective toxins, and this factor constitutes the most important evidence of their toxin-like character. General Properties. — These toxins resemble proteins in many respects. Jacoby, however, has placed them in the same class as bacterial toxins and enzymes, i. e., large molecular colloids closely resembling the proteins, but still not giving the usual protein reaction. More recent work by Osborne, Mendel, and Harris,1 however, does not support Jacoby's view. These observers found the toxic properties of ricin inseparably associated with the coagulable albumin, and were able to isolate it in such strength that 10100 milligram was fatal per kilo of rabbit, and solutions of 0.001 per cent, would agglutinate red corpuscles. Relation to Immunity. — The phytotoxins, since they obey the same laws as bacterial toxins, have been very serviceable in the study of immunity; they are more stable than the latter, and can be handled in more exact and definite quantities. They have apparently the same haptophore and toxophore structure as bacterial toxins; antitoxins are readily produced by immunizing animals, and seem to be specific for the toxins; in fact, Ehrlich made his earliest observations on the specificity and quantitative factors in toxin-antitoxin immunity from a study of these plant toxins. The Toxin of Hay-fever. — Pollen toxin has been described by Dunbar2 as the etiologic factor in the production of hay-fever. In all, the pollen of 25 varieties of grass and seven varieties of plants have been found capable of producing attacks of hay-fever in susceptible persons. This susceptibility to pollen intoxication is, fortunately, limited, and the sudden onset of an attack and the characteristic symptoms indicate an anaphylactic reaction due to sensitization with pollen protein. Dunbar has succeeded in producing a pollen antitoxin, which will be described in the chapter on Passive Immunization; the reports of various observers are, however, at variance in regard to its therapeutic value. It is highty probable that the toxic substance in ivy, sumac and other plants responsible for vario.us forms of dermatitis venenata, is of the nature of plant or phytotoxin of protein nature. The most important animal toxins (zootoxins) are those of the toad, spider, snake, scorpion, and bee. The most striking characteristic of these toxins is that an immunity against them can be established; in this respect they resemble true toxins. All are quite complex in structure and properties, and all are more or less hemotoxic. Snake Venoms.1 — Medically, these are of particular interest. They were first thoroughly investigated by S. Weir Mitchell (1860) and Mitchell and Reichert (1883), and have aroused considerable attention because of their similarity to bacterial toxins and the aid their study has been in the elucidation of immunologic problems. Properties of Venom. — In 1883 Mitchell and Reichert described two poisonous proteins, constituents of venom, one of which seemed to be a globulin and the other a proteose or "peptone." Faust2 believes that the poisons are not proteins, but glucosids free from nitrogen, and that they belong to the saponin group of hemotoxic agents. It may be that these glucosids are bound to proteins, and can be removed with the globulin in fractional separation, or that they may come down, at least in part, with the albumoses of the venom. Various enzymes have been found in venoms; e.g., proteases (Flexner and Noguchi) and Upases (Noguchi); the latter probably have a definite relation to many of the effects of venom intoxication, especially hemolysis and fatty degeneration of the tissues. The poisons, as a rule, produce both local and severe general disturbances, the rapidity of the onset of the symptoms and the prognosis in a given case depending largely on the situation of the bite. Most of these poisons exert their effect primarily upon the nervous and vascular systems, besides exhibiting other toxic properties. Nature of Venoms. — All snake venoms possess a hemolytic power, and venom hemolysis is one of the most interesting of biologic phenomena. Flexner and Noguchi8 have distinguished and classified the various elements as hemotoxins, hemagglutinins, neurotoxins, leukotoxins, and endotheliotoxins (hemorrhagin). The endotheliolytic action of the toxins is shown in the glomerular capillaries, where it causes hemorrhage and hematuria (Pearce4). Cobra hemotoxin is especially characterized by its power of dissolving the corpuscles of certain species (man, dog, guinea-pig, rabbit) without the presence of serum. The explanation of this interesting phenomenon has excited extensive discussion. It is probable that the hemotoxin is in the nature of an amboceptor (Flexner and Noguchi), which is activated, in the absence of serum, by complementing substances (chiefly lecithin) present in the red cells, and in this manner producing hemolysis of these cells. In syphilis the quantity of red-cell lecithin is probably diminished after the primary stage, so that when using definite dilutions of venom that are known to hemolyze a certain quantity of normal erythrocytes, an absence of hemolysis of the red corpuscles of a given patient would infer a decrease in complementing lecithin in these corpuscles and indicate the presence of syphilis. The technic of this reaction and its value as a diagnostic procedure will be discussed further on under the head of Venom Hemolysis. There are a large number of microorganisms, notably the cholera spirillum, the typhoid bacillus, the pneumococcus, and other pyogenic cocci, which, when cultivated and separated from the culture-fluid by filtration, are found to be highly poisonous, whereas the filtrate itself is practically devoid of toxicity except for the soluble hemotoxic substances. In other words, we are dealing with endotoxins, or poisons that are not secreted into the medium in which the bacteria are growing, but are contained more or less firmly within the bacterial body, from which they are separable by some method of extraction or by autolysis, only after death. Method of Obtaining Endotoxic Substances. — Endotoxic substances are obtained from bacteria by thorough disintegration of the bodies. This is accomplished by various methods: (a) The substances may be found in old cultures as a result of death and disintegration of numbers of bacteria; (6) they may be obtained by suspending the microorganisms in distilled water and shaking in a machine, much as Wassermann and Citron's artificial "aggressins" are prepared; (c) the bacteria may be dried and ground to a fine powder, as in the preparation of Koch's "bacillen emulsion" of tubercle bacilli; (d) MacFadyen freezes masses of bacteria with liquid air, and then grinds them into a fine powder; (e) Conradi recommends autolyzing the bacterial cells in non-nutrient fluids; (/) Rosenau has studied the endotoxins of pneumococci obtained by alternate freezing and thawing of suspensions in distilled water; (g) ENDOTOXINS 123 Vaughan has devised a method of growing massive cultures on solid media several square yards in extent, removing the bacteria with sterile salt solution, and digesting the bacterial masses with an excess of a 2 per cent, solution of caustic alkali in absolute alcohol. Nature of Endotoxins. — Owing to their insoluble nature, endotoxins in pure form and free from other products of bacterial activity, cannot be obtained. As a result, their chemical nature and structure are unknown. Tuberculin, which was formerly believed to be an albumose, may be produced in a protein-free medium; it seems probable that this substance is of the nature of a polypeptid, giving no biuret reaction, but being destroyed by pepsin and trypsin (Laevenstein and Pick J). Whether or not tuberculin is an endotoxin liberated upon the disintegration of the bacilli is unknown. Pick regards it as a secretory product closely related to the true toxins. It is probable that some toxin is actually secreted into the culture-medium, and that the major portion, which is of a somewhat different nature, is intimately related to the constituents of the bacterial cells. There is little doubt but that endotoxic substances are highly poisonous, and that they are chiefly responsible for the characteristic symptoms of diseases produced by the bacteria that contain them. Whether, however, they are actually preformed definite and specific constituents of bacteria, or merely the poisonous products of disintegration of the bacterial proteins, is still undecided. It would appear that bacteria produce and contain toxic substances. When, owing to the peculiar structure of the bacterial protoplasm or nature of the toxic substance itself, the toxin can diffuse readily into a surrounding medium, the toxic substance is known as a true, soluble, or extracellular toxin; when the toxin enters into combination with the bacterial protoplasm, it becomes known as an endotoxin. This union of toxin and bacterial protoplasm may be so firm as to render the toxic substance inseparable from the bacterial protein. The various toxic substances or toxins differ, therefore, according to their diffusibility through the membrane of bacterial protoplasm, or their power of combining with these protein substances, or both factors may be operative. Satisfactory antitoxins for endotoxins have not been produced, and this is an important point in differentiating between a true toxin or an endotoxin of any particular microorganism. Animals immunized against endotoxin ^iochem.'Zeit., 1911, 31, 142. develop substances in their serum that are bactericidal, bacteriotropic, and agglutinative to the bacteria from which the poisons were derived, but the serum itself is not antitoxic for the endotoxins. Therapeutic serums for use against infections caused by the endotoxin class of bacteria are largely bacteriolytic and bacteriotropic in action. The endotoxins of some bacteria, and particularly those of streptococci, seem to repel the leukocytes, or exert a negative chemotactic influence, which may effectually retard or entirely prevent phagocytosis; in this respect they resemble the aggressins of Bail. Immune serums owe a portion, at least, of their therapeutic value to the power they possess of overcoming this influence and facilitating phagocytosis. These serums, however, have not proved of as much value as have the diphtheria and tetanus antitoxins in the treatment of the respective infections mentioned, and have proved a check to the progress of serum therapy. It is probable that the endotoxins are more specific for the various strains of the same species than are the true toxins, as indicated by the results of Cole in the treatment of pneumonia with an anti-pneumococcus serum corresponding to the type of microorganism responsible for the individual infection, as determined by a rapid method of diagnosis previous to the administration of serum. AGGRESSINS In an attempt to explain certain observations of Koch to the effect that when a tuberculous animal is injected intraperitoneally with a fresh culture of tubercle bacilli it succumbs quickly to an acute attf»<^ ^ the disease, the resulting exudate being composed almost exclusively of lymphocytes, Bail1 has advanced the hypothesis that bacteria may secrete aggressins, or substances that aim to protect the microorganism by either neutralizing the action of opsonins or directly repelling the body-cells and preventing phagocytosis. Bail found that if he removed a tuberculous exudate, sterilized it, and injected it into healthy animals, it had practically no effect. If tubercle bacilli were injected alone, lesions would develop in the usual number of weeks; but if sterile exudate and tubercle bacilli were injected together, death would follow in about twenty-four hours, indicating that the exudate contained a substance that acutely paralyzed the defensive forces of the animal, and thus greatly increased the virulence of the bacilli. That this effect was not the summation of endotoxins in the exudate plus living microorgan- isms was shown by Bail, who found that when large quantities of exudate alone were injected no untoward effects resulted, whereas the injection of a small amount of exudate, plus a sublethal dose of bacteria, would regularly produce acute infection and death. Bail therefore concluded that the exudate contained a substance that allowed the bacilli to become more aggressive, and for this reason he called this hypothetic substance "aggressin. " He assumes that in a tuberculous animal the tissues are permeated with the aggressin, and that when fluid collects in the bodycavities after the injection of tubercle bacilli, this fluid contains large quantities of aggressin. This prevents migration and collection of polynuclear leukocytes, but not of lymphocytes, and hence allows the bacilli to develop rapidly, producing acute symptoms. On the other hand, when tubercle bacilli are injected into the peritoneal cavity of a healthy guinea-pig, polynuclear leukocytes which engulf the bacilli are attracted, thus inhibiting their rapid development, there being no aggressin to prevent phagocytosis. Similar results were obtained with other microorganisms. Bail inoculated cholera and typhoid bacilli into the pleural and peritoneal cavities of animals, and an acute local infection occurred. From the exudates so produced he removed the bacteria by centrifugalization, and completed the sterilization with antiseptics or with heat at 44° C. The clear fluid obtained was found to possess but mild toxic properties, and large amounts could be injected into animals of the same species without producing any marked effects; when, however, it was injected into an animal together with a sublethal dose of the particular microorganism, an acute and fatal infection followed. Similar results were secured with the bacilli of dysentery, chicken cholera, pneumonia, and other diseases. Bail's Classification of Bacteria. — Bail found that bacteria differed in their power of forming aggressins; he therefore used this principle in making a division of bacteria into three classes, according to their disease-producing power, as dependent largely upon whether or not the microorganism can produce an aggressin that is active against the protective forces of the host, particularly against opsonins and leukocytes. doses, do not produce any characteristic disease. 2. True parasites, or those bacteria that, when injected even in the smallest amounts, will produce disease and death. These are truly virulent, and the number of bacteria increase so rapidly as to be demonstrable in every drop of blood and in all the organs. Examples of true parasites are the bacilli of anthrax and of chicken cholera, the tubercle septicemia for rabbits. 3. Half or partial parasites are those bacteria the infectious nature of which depends upon the number of bacteria injected. The smaller the number, the milder the sjTnptoms, until a dose is reached below which no disturbances are produced. Organisms of this class possess some virulence and toxicity, examples being the Bacillus typhosus and the Spirillum cholerae. It is to be remembered, however, that these effects are but relative, and dependent upon the organism, the species of animal, and the mode of infection. For example, the bacillus of anthrax is saprophytic for the frog and hen unless the temperature of these animals is brought to the body temperature of the human; a bacillus of the group of hemorrhagic septicemia of rabbits is saprophytic for human beings, a half parasite for the guinea-pig if injected subcutaneously, and a true parasite for the same animal if injected intraperitoneally. Nature of Aggressins. — The aggressins in inflammatory exudates are presumably substances capable of paralyzing the protective agencies of the body. Bail regards the aggressins as of the nature of endotoxins liberated from the bacteria as a result of bacteriolysis, and believes that they act by paralyzing the polynuclear leukocytes, thereby preventing phagocytosis. In general, the production of these aggressins goes on more actively the greater the resistance to the bacteria; they are produced in greater quantities during the struggle between the bacteria and the body-cells, although they may be produced artificially in the testtube with large numbers of bacteria and a non-poisonous agent (serum or distilled water) which can disintegrate the cells. In this manner Wassermann and Citron have produced "artificial aggressins, " which act in the same general manner as the "natural aggressins" of Bail. By many the aggressins are regarded as endotoxins, and while they may possess the nature of endotoxic substances, it is to be remembered that there is no definite relation between the poisonous qualities of the aggressins and their power to increase the virulence of an infection. It is probable, as has been shown by Wassermann and Citron, that pathogenic bacteria contain small amounts of natural aggressin. This aggressin may be regarded as a normal antibody of the bacterium against the defensive forces of the body-cells of a host. During infection these aggressins or antibodies are naturally greatly increased, as the bacteria require more and more protection. Being contained to some extent within the bacterial cells, the antibodies are somewhat similar to endotoxins: while endotoxins may be regarded as offensive agents of bacte- BACTERIAL PROTEINS ria, aggressins may be their defensive agents. This belief is in keeping with the hypothesis of Welch1 and also of Walker2, according to which it may be presumed that bacteria, as living cells, when so placed that they are exposed to the defensive forces of their host, are, under favorable conditions stimulated to produce reciprocal antibodies for their protection, and to generate them in increasing amounts as may be necessary. Bail regards the aggressins as new substances; as already stated others regard them as simple endotoxins; still others believe them to be free bacterial receptors, and that these receptors may combine with bacteriolytic amboceptors, producing, as it were, a deflection of the amboceptors, so that the bacteria themselves are not attacked, and thus continue to proliferate. The action of aggressins is not dependent upon the toxicity of the endotoxins, for the fluid containing them is devoid of toxic effects; at most, therefore, if they are of the nature of receptors, they possess no toxophorous portion. Whatever aggressins may be, and we regard them as antibodies of bacteria, just as bacteriolysins are antibodies of tissue-cells, they appear to be especially directed against opsonins. neutralizing these, paralyzing leukocytes, and thus inhibiting or entirely preventing phagocytosis. Anti-aggressins may be produced experimentally by gradually immunizing animals with sterile exudates, and this immunity may be transferred passively from one animal to the other by inoculation of its immune serum. These anti-aggressins are quite specific, and neutralize the aggressins in an exudate. In practically all bacterial bodies, after removal of toxins and endotoxins, a certain proteid residue remains, which, when injected into animals, is able to produce various grades of inflammatory reaction leading to tissue necrosis and abscess formation. This substance was first thoroughly studied by Buchner, who named it bacterial protein, and regarded it as identical in all bacteria, and having no specific toxic action, but characterized in general by its power of exerting a positive chemotactic influence on leukocytes, and thereby favoring the formation of pus. For example, in the development of an ordinary staphylococcus abscess it is probable that the proteins of the cocci, aside from their toxins, aid in producing tissue necrosis and in attracting leukocytes to the infected area. Similarly, an extract of dead tubercle bacilli may produce a it. Med. Jour., 1902, 2, 1105. 2Jour. of Path., 1902, 8, 34. tuberculoma or the tissue changes incident to tuberculosis, differing, however, from true tubercle in that they do not contain living bacilli and consequently are not infectious. When cultures of diphtheria bacilli are filtered and the residue washed, it is found that extracts of the bacterial substances or the bodies of the dead bacilli themselves are quite free from the typical toxin; but the bacterial substances or the proteins isolated from them, when injected into the subcutaneous tissues of animals, are found to produce a strong inflammatory reaction and necrosis of the tissue-cells. Bacterial Split Proteins. — These have been studied extensively by Vaughan and his coworkers, who have ascribed to them the chief role in and a very important relation to the processes of infection and immunity. Massive cultures of colon, typhoid, pneumonia, and diphtheria microorganisms are grown in special large tanks containing agar; anthrax is grown in Roux flasks, and tubercle bacilli in glycerin beef-tea cultures. After removal of the growths the bacterial cellular substances are washed once or twice with sterile salt solution by decantation, and then repeatedly washed with alcohol, beginning with 50 per cent, and increasing the strength to 95 per cent. The substance is then placed in large Soxhelet's flasks and extracted first for one or two days with absolute alcohol, and then for three or four days with ether. These extractions should be thorough in order to remove all traces of fats and waxes. After extraction the cellular substance is ground, first in porcelain, then in agate mortars, and passed through the finest meshed sieves to remove bits of agar. The person grinding the cellular substance should wear a mask in order to protect himself against poisoning. Vaughan reports that, despite this precaution, several workers have been acutely poisoned, especially with the typhoid bacillus. Of course, there is no danger of infection, as the bacteria are killed during the treatment. If the finely ground cellular substance, in the form of an impalpable powder, is kept in widemouthed bottles in a dark place, it will retain its toxicity for years. This powder constitutes the bacterial protein substance, which may be split up by various means. Vaughan found digestion with 2 per cent, caustic soda in absolute alcohol especially satisfactory for extracting the poisonous group from bacterial or any other protein. A weighed portion of the protein, prepared as above, is placed in a flask, covered with from fifteen to twenty-five times its weight of absolute alcohol in which 2 per cent, of sodium hydroxid has been dissolved. The flask, fitted with a reflux condenser, is heated on the water-bath for one hour, where it is allowed to cool and the insoluble portion collected on a filter. After thorough draining the insoluble part is returned to the flask and the extraction repeated. It has been found that three extractions are necessary in order to split off all the poisonous group. The temperature of these extractions is 78° C., the temperature of boiling absolute alcohol. By this method the protein is split into two portions, one of which is soluble in absolute alcohol and is poisonous, while the other is insoluble in absolute alcohol and is not poisonous (Vaughan). Nature of Bacterial Proteins. — Vaughan and his coworkers regard bacteria as essentially parti culate, specific proteins. He has not been able to demonstrate the presence of cellulose and carbohydrates; fats and waves that may be present are somewhat secondary and less essential constituents or stored food material. The sum total of the work of these observers would indicate that the greater part of bacteria are made up of true proteins, especially nucleoproteins or glyconucleoproteins, and although they may be simple in structure, they are chemically complex — quite as much so as many of the tissues of the higher plants and animals. When bacterial cellular substances are split up with mineral acids or alkalis they yield ammonia, mono-amino- and diamino-nitrogen, one or more carbohydrate groups, and humin substances. These protein substances are the same as those obtained by the hydrolysis of vegetable and animal proteins. By digestion with dilute acids or alkalis, especially the latter, in the form of a 2 per cent, solution of sodium hydroxid in absolute alcohol, a soluble split product is obtained that resembles in some respects the protamins, although they do not all give a satisfactory biuret reaction. This product is highly toxic, but shows no specificity in its action, being the same whether derived from pathogenic or from non-pathogenic bacteria, or from egg albumin or other protein substance. All that is definitely known regarding it is that it is toxic, protein in nature, but simpler in structure than the complex proteins of the bacterial cells themselves. This soluble toxic portion as obtained in vitro is regarded by Vaughan as the main factor in the production of the general symptoms of infection, the special and distinctive lesions being due to the location of the infection. During the infective process the body-cells produce an antiferment which, when it reaches a certain concentration or power, begins to split the protein of the microorganism and new bacterial tissue, with the liberation of this toxic moiety, in a manner similar to the. splitting observed in vitro by dilute alkalis or acids. The insoluble and non-poisonous portion of the cellular proteins shows most of the color reactions for proteins, and contains all the carbohydrate of the unsplit molecule and most of the phosphorus. Action of Bacterial Proteins. — The effects produced by bacterial proteins are not specific; the protein substance of non-pathogenic bacteria and, indeed, many proteins derived from vegetable and animal sources, have equally marked pyogenic properties. All foreign proteins introduced into the circulation of animals are more or less toxic, and the toxic effects of all bacterial proteins are, hi general, quite similar and non-specific. Bacterial protein substances may be responsible for certain minor anaphylactic reactions, as has been observed occasionally in the administration of ordinary bacterial vaccines. They may bear an important relation to the development of the state of hypersensitiveness of a tuberculous person in the course of a series of tuberculin injections. Theory of Vaughan. — According to Vaughan and his coworkers, all true proteins contain a common and non-specific poisonous group. This group may be regarded as the central or key-stone portion of every protein molecule, with secondary and possibly tertiary subgroups, in which the specific property of different proteins is inherent. When the main or primary group is detached from its subsidiary group, it manifests its poisonous action by the avidity with which it attacks the secondary group of other proteins. These are detached from their normal positions, and consequently deprive the living protein of its power of functionating normally. When proteins are split, the chemical nucleus or non-specific toxic portion is more or less completely set free, and its toxicity varies according to the thoroughness with which the secondary groups have been removed. The pathogenicity of a bacterium is determined not by its capability of forming a poison, but by the ability it possesses to grow and multiply in the animal body. When, during an infection, a pathogenic microorganism reaches the deeper tissues, it is not immediately killed by the defensive ferments of the host, but continues to grow and multiply, throwing out a ferment that feeds upon the native proteins of the bodycells, tearing them down and building up a specific bacterial protein that may select a certain point of predilection in which it is most prone to accumulate. Thus the typhoid bacillus accumulates in the adenoid tissue of Peyer's patches on the intestine, the spleen, and the mesenteric glands; the pneumococcus tends to lodge in the lungs; the smallpox virus selects the skin, etc. The bacterial toxins and viruses, as, e. g., diphtheria toxin and the virus of smallpox, are regarded as ferments of protein nature, capable of attacking native body protein and building up a specific foreign protein. This foreign bacterial protein is formed during the period of incubation of disease when there is no effective resistance on the part of the body-cells to its growth and multiplication. During this time the infected person is not ill, so that the foreign protein in itself cannot be toxic, and the body-cells are busy preparing and elaborating a new and specific ferment that will digest and destroy the foreign protein. When this new ferment becomes active, the first symptoms of disease PTOMAINS 131 appear, and the active stage of the disease marks the period over which the parenteral digestion of the foreign protein extends. These specific ferments split up the foreign protein and liberate the toxic portion or the protein poison; this poison is not a toxin and is not specific, but occurs commonly in all proteins. The characteristic symptoms and lesions caused by the various infectious processes are determined largely by the location of the foreign protein. The poison elaborated is the same in all infectious diseases, and it is the location of the infection, rather than the exact nature of the infecting agent, which gives rise to the more or less characteristic symptoms and lesions of the several infectious diseases. Death may be produced by the too rapid breaking-up of the foreign protein, and the consequent liberation of a fatal dose of the protein poison, or it may result from a lesion induced by the products of this disruption, such as perforation , of the intestine and hemorrhage in typhoid fever, or it may follow from chronic intoxication and consequent exhaustion. If recovery takes place, the individual enjoys an immunity of variable duration, owing to the presence of specific ferments capable of destroying the particular substrata if infection should occur. It is this power of body-cells, when permeated by a foreign protein, to elaborate a specific antiferment by which the protein is destroyed, that, in the opinion of Vaughan, forms the basis of a correct understanding of infection and immunity. * It was at one time believed that the symptoms of many diseases were due to the absorption of soluble basic nitrogenous substances produced by bacterial action upon various albumens, these toxic, alkaloidlike substances being known as ptomains. It was soon found, however, that the ptomains produced by pathogenic bacteria were insufficient of themselves to cause the symptoms and lesions characteristic of the respective microorganisms; that they were in general less toxic than the cultures themselves; that the majority of ptomains are not very poisonous; and that they are not specific, since equally potent ptomains are produced by non-pathogenic bacteria. This lack of specificity is in sharp contrast to the toxins. No matter upon what medium a true toxin producer is grown, the toxin is qualitatively the same, whereas the nature and toxicity of ptomains depend upon the microorganism, the culture-medium used, the duration of growth, and the quantity of oxygen or under, different conditions, may produce totally different ptomains. Ptomains may, however, produce disease, and even death, when they are ingested with food that has undergone bacterial decomposition. In most instances of meat-poisoning, however, which are frequently ascribed to the presence of ptomains, a specific microorganism, the Bacillus botulinus, or a member of the Bacillus enteritidis group of Gartner, is usually responsible. The commonest sources of ptomain poisoning are improperly preserved meats, fish, sausages, cheese, icecream, and milk. This subject received full consideration in Vaughan and Novy's "Cellular Toxins." A number of ptomains are known, and of some the exact chemical constitution has been established. Brieger has separated one from decomposing flesh and cholera cultures, called cadaverin, which Ladenburg has shown to be pentamethylendiamin, and prepared synthetically. Muscarin, isolated by Schmiedberg and Brieger, and tyrotoxicon, isolated by Vaughan, are also well known. In the isolation of bacterial ptomains Brieger's method is generally employed, which consists of acidulating large amounts of culture with hydrochloric acid, boiling, filtering, evaporating the filtrate to a syrupy consistency, dissolving in 96 per cent, alcohol, and precipitating and purifying by means of an alcoholic solution of mercuric chlorid. Besides occurring in food-poisoning, ptomains may be formed as the result of putrefactive processes going on in abscesses, gangrenous areas, and within the gastro-intestinal canal, and enough of these may be absorbed to produce symptoms of intoxication. Under these conditions it is possible for bacteria to produce ptomains that may be absorbed and produce symptoms of intoxication without the bacteria themselves actually gaining entrance to the tissues, and therefore not constituting, according to our definition, a true infection. Pernicious anemia, chlorosis, and allied conditions have been ascribed to the absorption of such ptomains from the intestinal canal. Obviously it is difficult or impossible to always differentiate between bacterial toxins and bacterial ptomains, or the products of protein decomposition dependent upon bacterial activity, and we can but admit the possibility of the production and absorption of both bacterial toxins and ptomains under certain pathologic conditions. Most ptomains probably are produced as the result of decomposition of the dead protein medium upon which the bacteria grow, and to a lesser extent by the destruction of the bacterial cells them- MECHANICAL ACTION OF BACTERIA In former years the theory as to the influence of mechanical blocking of vessels with masses of bacteria was regarded with much favor in the etiology of certain infections, particularly anthrax. At the present time this factor has not the same importance, for while it is true that bacterial emboli may occasion harm by blocking important vessels, further researches have shown that it is doubtful if any pathogenic microorganisms are totally devoid of toxic action, and that their toxins are largely responsible for the tissue changes and symptoms of infections. It can readily be understood that emboli of microorganisms may produce metastatic lesions; thus when staphylococci are injected into the ear vein of a rabbit they produce abscesses in the kidney and heart, and masses of bacteria from an ulcerative endocarditis, when carried to different portions of the body, will cause abscess formation; but the question in hand, however, deals with the effects of mechanical blocking itself. Investigations with anthrax bacilli have shown that they are remarkably free from soluble toxins and endotoxins, although the local lesion develops so rapidly and becomes so quickly necrotic as to suggest very strongly the action of some local toxic substance. Cases of human anthrax seldom prove fatal if the lesion is removed and the blood-stream remains free from the bacilli. Vaughan has shown that anthrax protein possesses toxic qualities, and since the majority of fatal cases of anthrax show enormous numbers of bacilli in the blood-stream and internal organs, it may be that this bacteremia produces an accumulation of toxins which is greatly augmented when the body-cells of the host have produced an antiferment that splits up the protein of the bacilli, the combined toxic substances being responsible for the severe symptoms and death. With protozoan disease, the possibility of serious symptoms following blocking of vessels is far greater, and, indeed, the cerebral symptoms of malignant malaria and sleeping sickness may be due in part to the blocking of small, but physiologically important, vessels with masses of plasmodia and Trypanosoma gambiensi, together with the absorption of toxic agents and the products of disintegration. Thus Bass, who has successfully cultivated the malarial plasmodium outside of the body, believes that the parasites, after attaining sufficient size, lodge in the capillaries of the body, especially where the blood-current is weakest, and where slight obstruction occurs as the result of the protruding inward of nuclei of the endothelial cells. Here they remain and develop until segmentation takes place. In the meantime other red corpuscles are forced against them, and if the opening in the infected cell is in a favorable location, one or more merozoites pass directly into another cell; if it is not, the merozoites are discharged into the blood-stream and are speedily killed. INFECTION WITH ANIMAL PARASITES Infection with animal parasites is similar in many respects to infection with bacteria. Owing to the difficulty of isolating and cultivating these parasites in vitro, our knowledge of their toxic properties is somewhat meager. Most attention has been given to a study of their life history and the modes of transmission. Modes of Infection. — Primary infection with animal parasites is often facilitated by, or in some instances only rendered possible through, the intervention of special carriers, usually various species of the Arthropoda. Thus we now know that malaria is transmitted through the bite of infected mosquitos; African relapsing fever and Texas cattle fever, through the bite of certain infected ticks; trypanosomiasis, through biting flies. The ova of various intestinal parasites may require residence in certain of the lower animals before they can infect man. Infection may occur along the same routes as bacterial infection, and is governed in general by the same factors of local selection, tissue susceptibility, etc. Biting insects usually deposit the parasite directly in the subcutaneous tissues or in the circulatory fluids. Abrasion of the epithelium may be necessary in order to produce infection with Treponema pallidum, as in the majority of the bacterial infections. The ova or larva of other parasites may be swallowed or find lodgment in the upper or lower air-passages or accessory sinuses. It would appear that our natural defenses against infection with animal parasites are much weaker than those against bacteria; this is probably due to the greater resistance offered by animal parasites to such physical destructive influences of the host, as the acidity and germicidal activity of the secretions, temperature, etc., as well as to a general lack of natural antibodies in the body-fluids of the host, and inability of leukocytes and other phagocytic cells to deal successfully with the invaders. That natural immunity against infection with certain animal parasites may exist is shown by the prevalence of certain infections among man, and their absence among lower animals, or vice versa. The aggressiveness of animal parasites is in general probably even greater than that of most bacteria, and a more or less extensive infection apparently occurs in all cases in which the parasite had made successful invasion, some multiplying in the blood-stream (malaria, relapsing fever, trypanosomiasis, Texas fever, filariasis), others in the lymphstream (filariasis), and others in the tissues (syphilis, trichiniasis, amebiasis) without much opposition on the part of the host. Whether these factors are due to the aggressive forces of the parasites which neutralize the defenses of the host, or whether they are due to the hardiness of the parasites and a lack of defense on the part of the host, is not known, but probably the latter is generally the case. As with bacteria, animal parasites show a well-marked selective affinity for certain tissues, as the malarial plasmodium for red bloodcorpuscles, trypanosomes and spirochetes for blood plasma, trichina for voluntary muscle, various parasites for the intestinal canal and even for certain portions of the intestinal tract, others for the lung, etc. Production of Disease. — Comparatively little is known regarding the formation of toxic products on the part of the animal parasite. Some, as, e. g., the Treponema pallidum and spirochete of relapsing fever, probably cause disease largely through the production of toxins, especially of the intracellular variety. The chill, fever, and sweat of malaria suggest the liberation of toxic products coincident, or nearly so, with segmentation and rupture of the plasmodium. The late symptoms of sleeping sickness and the whole course of relapsing fever are strikingly similar to the bacterial toxemias. The metabolic products of all animal parasites are probably injurious in some manner and to some degree. The pathogenicity of others is due, in part at least, to mechanical blocking of vessels, as with the filaria, trypanosomes, and malarial organisms ; others (hookworm) abstract blood or consume food material in the intestine, as the intestinal parasites; and others, as migrating foreign particles with irritating secretions, produce local inflammatory changes. Nevertheless, we know comparatively little of the offensive factors, and still less of the immunologic defensive factors, operative during the course of infections with animal parasites. With the development of a technic for the cultivation of animal parasites in vitro similar to that devised for the ameba, certain trypanosomes, spirochetes, and malarial plasmodia, we will be enabled to study the products of their growth or of disintegration, and the immunologic agencies concerned in infection and recovery; this offers a very important and fruitful field for research. following stages : 1. The period of incubation, which begins at the time of infection and ends with the development of the earliest general symptoms, during which time the invading bacteria are multiplying in the tissues of the host. During this stage no symptoms, or only those of a purely local nature, are present. This period varies considerably in different infections, and to a lesser extent in different individuals having the same infection. Some bacteria may be so virulent as to overwhelm the bodycells, thus making the period of incubation very short or entirely unobservable. On the other hand, as, e. g., in rabies, the period may be of several weeks' and, indeed, of several months' duration. In tuberculosis there is usually a primary local growth, which develops so gradually and the toxins are so slowly diffused that it is difficult or, indeed, impossible, to estimate the length of the period of incubation. According to Vaughan, during the period of incubation the bacteria or their toxins or the viruses are actively engaged in changing the natural body proteins into new and specific bacterial proteins, and since this stage is constructive, there are no symptoms and the host is not ill. Even with the experimental administration of the most poisonous of toxins a definite period of incubation is usually to be observed, which cannot be reduced below a certain minimum, independent of the size of the dose injected; in general, however, a large dose of bacteria or of toxin is likely to be followed by a shorter period of incubation than if a smaller dose were administered. several factors: (a) The number of bacteria gaining entrance, and especially their toxicity and aggressiveness. The primary factors are the degree of toxicity and the amount of toxic substances produced and absorbed. (6) Upon the site of infection. Thus the introduction of rabies virus or of tetanus bacilli into the tissues of the face or into a deep wound is likely to be followed by a shorter period of incubation than when these are introduced into the foot or in superficial wounds. (c) Upon the degree of resistance offered by the host. For instance, one individual may contain more antitoxin or bacteriolysin for a certain bacterium than another, and consequently a longer period of incubation is required, during which these substances are neutralized and an excess of toxic bacterial substance is produced. In fact, these may offer such resistance to the bacterium that the process of infection is inhibited, or but slight and evanescent disturbances appear. listurbances of a relatively mild type, due to diffusion of the bacteria and their products into the general circulation and their wide-spread effect upon the body-cells in general. If the bacteria select a special tissue or organ for attack, as the typhoid bacillus for lymphoid tissue, and pneumococci for the lungs, definite symptoms develop later, their nature depending on the special tissue or organ involved. The prodromata, however, are more marked, and indicate a wide-spread but mild action upon the body-cells in general. Vaughan believes that these symptoms mark the time when sufficient proteolytic ferments have been generated by the body-cells against the new bacterial protein of the invading bacteria to attack the. latter, splitting the molecule and liberating a toxic moiety responsible for the general symptoms of intoxication. 3. The period of fastigium, or of high fever, during which the disease is at the height of its severity. Special and distinctive symptoms and lesions, according to the organ or organs especially involved, are present; the struggle between the offensive and defensive forces of parasite and host is at its height, with remissions or exacerbations dependent upon the supremacy of any one of these, and the general stability of the bodycells in withstanding the wear and tear. During this time the protective proteolytic ferments of Vaughan are most active in disrupting the newly formed bacterial protein, with the liberation of the toxic portion. This process may be so active as to overwhelm the host with the toxic split product, or lead to grave secondary lesions, such as extensive necrosis, perforation of a viscus, or hemorrhage. host gradually overcomes the effects of disease and returns to health. During this entire time the emaciation and tissue exhaustion leave the patient quite weak, and undue exertion, errors in diet, or reinfection may lead to a relapse, or a reactivation of the disease. Certain sequelae or morbid conditions may follow a disease, and are due to the same original cause; e. g., in typhoid fever the development of cholecystitis; at any time during the disease complications, or morbid conditions due to some other microparasite, as the development of pneumonia during the course of typhoid fever, may seriously jeopardize the life of the patient. Grades of Infection. — According to the manner in which a parasite and its products act upon the cell of a host and the power of the host to neutralize or overcome these the following various grades and types of infection are encountered : (a) Malignant or fulminating infection, during which there is no fever, but, on the contrary, a subnormal temperature, with rapid prostration of the patient and death within a brief period. The cells of the body are overwhelmed and paralyzed by the toxic substances; metabolism is arrested, and the heat centers are exhausted with the fall of the temperature, an indication of the intense and overwhelming intoxication. (b) Acute infection, which is the ordinary type of an infectious disease as previously described, and having a definite incubation period, prodromal symptoms, fastigium, defervescence, and convalescence. (c) Chronic infection, or a prolonged process characterized by insidious onset and symptoms of relatively mild or moderate severity, and terminating either in death, after months or years, or in gradual recovery. A chronic infection may be remittent, as may be observed in the rheumatic group of disorders; during the remission with defervescence the infecting bacterium is not totally destroyed, - and subsequently lights up, producing an acute exacerbation of the disease. In chronic infections it would appear that the parasites develop and produce their toxins slowly, or that these are slowly and imperfectly absorbed on account of the sluggish local circulation and the presence of scar tissue. The body-cells become accustomed, as it were, to these toxic products, and produce only sufficient antibodies to effect their immediate neutralization. The bacteria themselves become distinctly resistant to the action of the tissues and the defensive forces, and there is neither the same degree of intoxication nor reaction as are seen in acute infections. Gradually, however, the body-cells become exhausted, and unless the cells are aroused and stimulated, by judicious administration of bacterial vaccines, to produce an oversupply of antibodies, the host shows progressive emaciation and weakness. The Systemic Reaction to Infection. — It is not within the scope of this book to discuss the various symptoms of infection, and we will limit ourselves to a brief discussion of the most important, namely, the febrile reaction. According to Vaughan, the fever of infection is due mainly to the toxic split protein resulting from the action of the protective proteolytic ferments upon the new bacterial protein. This observer and his associates were able, by the injection of multiple doses of protein derived not only from the typhoid bacillus but from various vegetable and animal proteins, to reproduce experimentally in rabbits a febrile reaction known as protein fever, and which is not unlike typhoid fever. This induced fever may continue for weeks, and is accompanied by increased nitrogen elimination and gradual wasting; it is followed by immunity, and the serum of immunized animals digests the homologous protein in vitro. As has repeatedly been stated, Vaughan regards the split toxic product as the cause of the general symptoms of infection, the special and characteristic symptoms and lesions of the different diseases depending upon the site where the bacterial proteins have been deposited, and where they are,, in large part at least, digested. In addition to this toxic action of split protein, fever may be due — (a) to the unusual activity of the cells supplying the proteolytic enzymes; and (6) to the cleavage of the foreign bacterial protein by these ferments. The fever of infection, therefore, is caused by the toxic action of pathogenic parasites, both bacterial and animal forms, upon the bodycells and heat-regulating centers. It must be regarded by itself as a beneficent phenomenon, inasmuch as it marks a reaction of the bodycells to toxic agents, for the purpose of neutralizing these and, by the development of antibodies, ridding the body of foreign substances. IN the preceding chapter on the mechanism of infection and the production of an infectious disease the statement was frequently made that the microparasites of disease are required to overcome the defensive forces of a host which are ever on guard to protect the organism against parasitic invasion and infection. Certain of these defenses are natural to the host, and in a great majority of instances suffice to protect the body against invasion and infection with bacteria, animal parasites, and various inanimate and injurious substances. When, however, these natural defenses are broken down and infection has occurred, the bodycells are not usually rendered powerless and completely overcome, for the products of infection serve as a stimulus to the body-cells, calling forth renewed cellular activity and the production of various specific defensive weapons, termed antibodies, which maintain an incessant struggle against the invading pathogenic agents in an effort to rid the body of them and to neutralize their products. Just as microparasites have various offensive weapons, consisting chiefly of their toxins, so, in like manner, the defensive forces of the host are numerous and even more complex. If the toxin of a microorganism is its chief pathogenic weapon, as, e. g., the soluble and extracellular toxin of the diphtheria or the tetanus bacillus, then the body-cells produce an antitoxin as their chief defensive force. If the offensive weapon is largely in the nature of an endotoxin, as, for example, the endotoxins of the typhoid or the cholera bacillus, then a chief antibody is in the nature of a bacteriolysin, which endeavors to dissolve the bacillus in an effort, as it were, to attack the enemy in his stronghold. In other* infections, especially those due to the pyogenic cocci, certain of the bodycells, and chiefly the polynuclear leukocytes, are observed in the tissues to have engulfed the invaders bodily (phagocytes) in an endeavor to digest them and neutralize their products. In addition to these chief antibodies, there are others that appear to aid them in their work. That one attack of many of the infectious diseases may protect the individual against subsequent attacks, or at least render subsequent attacks mild and harmless, is well known. In India and the East for THEORIES OF IMMUNITY 141 centuries practical advantage has been taken of this observation in the management of smallpox. In order to protect persons against a severe attack of variola they were deliberately brought in contact with a person suffering with a particularly mild form, in the hope that, by inducing a mild attack of short duration, they would thus obtain protection against the severe, disfiguring, and fatal form of the disease. The practice, however, was not without danger to the individual and to the public at large, as the induced disease would at times become malignant, and constitute a focus of infection for an entire community, When Edward Jenner discovered that inoculation with cowpox virus could not produce smallpox, but would, nevertheless, stimulate the production of specific antibodies and confer immunity against it, an enormous forward stride was taken that has since proved a priceless boon in helping to rid the world of the dreadful scourge of smallpox. The object of all these procedures has been to secure a resistance or immunity to smallpox, either by inducing a mild form of the disease or by protecting the individual by means of inoculation with a virus that has been so changed in its passage through a cow as to render it unable to produce smallpox, but yet is capable of stimulating the body-cells to produce antibodies that will neutralize the effect of the true virus. This induced resistance to a given infection constitutes immunity or resistance, and since the body was purposely inoculated and the body-cells rendered active in producing the antibodies, this form of resistance is known as active acquired immunity. Many persons recover from an infection that may have been unusually severe not because the infecting agent became exhausted or died for want of pabulum, but because it had been gradually worsted in the battle with the defensive forces of the host. In many such instances the host is now immune to this infection for a longer or shorter time, because the body-cells have been so profoundly impressed that they continue generating defensive weapons or antibodies for some time after the last vestige of the infecting agent has disappeared. Or, on the other hand, the quantity of antibodies may be so great that they may persist for varying periods of time, even for the remainder of life, ever on guard, and ready to overwhelm their specific enemy should it ever again gain access to the tissues. Here, then, arises the question concerning the mechanism of recovery from an infection, and since this is so intimately concerned with the general subject of resistance to disease, it is considered under the general head of immunity. Even superficial observation shows that not all persons are equally susceptible to a given disease, and during the course of epidemics it will be seen that some individuals, although freely exposed, escape infection. Certain species of animals may likewise display a uniform resistance to an infection that will readily enough attack another species of the same general family. It has been demonstrated experimentally that a certain pathogenic bacterium will produce a severe infection in one species of animals and not in another. It may frequently be noticed that even though an infection occurs, it is readily overcome by the natural resources of the host, the latter escaping with slight or no symptoms of disease. In other words, certain persons and animals apparently possess a natural resistance or immunity to disease, which may be general, non-specific, or due to specific antibodies, this type of immunity being frequently relative and seldom absolute. Definition. — Immunity, therefore, in a broad sense, is the effective resistance of the organism against any deleterious influence; in the usual and more restricted meaning the term is applied to resistance against infection with vegetable and animal parasites and their products, which are pathogenic for other animals of the same or of different species. It should be remembered that immunity means not only the ability to resist an infection or successful invasion of the tissues by microparasites, but also the continual resistance offered as long as the infection lasts; that is, immunity implies not only resistance to the onset of infection, but also to the course and progress of the resulting infectious disease. The science of immunity has, therefore, for its object the study of the mechanism of resistance to and recovery from an infection. HISTORIC The development of the science of immunity forms one of the most interesting chapters in the history of medicine. Even in ancient history we can trace the conception of our modern ideas on immunization. Hippocrates taught that the factor that causes a disease is also capable of curing it — practically the same theory as the more modern homeopathic doctrine of ((similia similibus curantur." Pliny the Elder recommended the livers of mad dogs as a cure for hydrophobia, thus coming very near to the basis of the Pasteur discovery. As was pointed out by Elizabeth Fraser, the same idea is expounded in the mythologic tale of Telephus, who cured his wound by applying rust from the sword which inflicted it, and in the story of Mithridates, King of Pont us (B. of ducks that had been treated with the corresponding toxic substances. Immunization against various venoms has been practised by many of the savage tribes of Africa since earliest times. Mention has previously been made of the method of preventive inoculation against smallpox practised in Asia and other Oriental countries for several centuries by exposing the subjects to mild cases of the disease. A very definite step in progress must ever be associated with the name of Edward Jenner, who first demonstrated experimentally, and in a scientific manner, that cowpox conveyed to man protected him against smallpox. Jenner was not the first person to make this observation, as many of the Gloucestershire farmers knew that cowpox protected them against smallpox; nor was he the first deliberately to inoculate persons with cowpox virus, as this method had been practised sporadically before his time. Jenner was, however, the first medical man to give the matter serious thought and consideration, and to test the method as thoroughly and scientifically as it was possible to do at that period. Thus he inoculated with smallpox virus those whom he had previously vaccinated with cowpox virus, and found them immune to smallpox. These experiments were courageously repeated, until a great truth was established, which has resulted in almost completely eradicating the disease from those countries or communities where vaccina-. tion is thoroughly carried out. As was to be expected, Jenner met with considerable opposition, and this is readily understood when it is remembered that even today — one hundred and eighteen years later — there are those who refuse to accept, or are unable to realize, the great benefits of this pioneer work. Jenner could not explain his results; he maintained that he was dealing with a modified form of smallpox. We of today have no better means of establishing the truth of the efficiency of cowpox vaccination, nor have we improved any on his method. The specific germ of smallpox is still undiscovered, and we must agree with Jenner that cowpox is probably a modified form of smallpox and practically harmless, the virus of cowpox being the virus of smallpox modified, attenuated, and rendered practically innocuous by passage through a lower animal. Nothing further of importance was accomplished during the following eighty years, until the next and even greater epoch ushered in the discoveries in bacteriology and the first immunization by Pasteur based on scientific reasoning. The chickens around Paris were being destroyed by a virulent intestinal infection, and Pasteur first isolated the causative microorganism, a minute bacillus, which he found was capable of producing the disease experimentally in healthy chickens. Quite by accident, so it seemed, he discovered that cultures of this bacillus could, by prolonged cultivation be attenuated, for when these cultures were inoculated into chickens, the fowls did not die or suffer any ill consequences; further, and what was of the utmost importance, when these same chickens were inoculated with virulent cultures, they were found to be immune to chicken cholera. Here, then, was the key to active immunization in the prevention of disease, and Pasteur possessed the genius to realize the full significance of his discovery. Armed with this knowledge Pasteur, and his assistants, Roux and Chamberland, next studied anthrax, an infectious disease of cattle that was causing a great annual loss to the farmers of France, and the bacillus of which was among the first pathogenic microorganisms to be discovered. It was found that prolonged cultivation of this bacillus was insufficient to attenuate the cultures, as the spores were highly resistant and retained their pathogenicity under extreme circumstances and over prolonged periods of time. In 1880 Touissant published a method of attenuating the bacilli by heating the blood of an infected animal to 55° C. for a few minutes; later, Chauveau secured similar results by heating fresh cultures for a few minutes at 80° C. Both methods were uncertain, and neither safe nor practical. After prolonged experimentation Pasteur found that cultivating the bacilli at the relatively high temperature of from 42° to 43° C. resulted in gradual attentuation, and if this cultivation was continued, the cultures were robbed entirely of their disease-producing power. Further, subcultures of these growths when kept at 37° C. did not regain their original virulence, but maintained for generations the grade of attenuation reached in the original culture the result of cultivation for a certain number of days at the higher temperature. In this manner Pasteur was able to control to some extent the degree of attenuation, and by inoculating first a highly attenuated and later a less markedly attenuated culture he could immunize animals against anthrax. This discovery was soon amply verified. The original method is practically the one employed today, and is proving of considerable economic value. Pasteur's next great experiment was undertaken for the relief of rabies, a condition in which, for the first time, he came to deal with a disease that not infrequently affects man. His success and the results of his discovery of an effective means of immunization against hydro- phobia were even greater than in previous experiments. Here he was dealing with a disease of unknown etiology, the causative agent of which he could not cultivate artificially, but which he sought to attenuate by a new process — that of drying. the tissues of the brain and spinal cords of infected animals. He then invented a method of inoculating animals by making subdural injections of an emulsion of these tissues. By repeated passage of a virus through a number of rabbits a virus of fixed pathogenic power (virus fixe) was obtained. By inoculating rabbits with this virus and removing their spinal cords immediately after death and drying these over a desiccating agent at room temperature, he found that he could modify the virulence of the virus at will, depending on the length of the period of drying. By emulsifying small portions of attenuated spinal cord in salt solutions and injecting these he was able gradually to immunize animals against rabies, and finally he applied the treatment successfully to the prevention of rabies in the human being. Antirabic vaccination is largely responsible for extending our knowledge of the possibility of securing immunization. Pasteur has taught us at least three different methods for modifying a virus in the preparation of a vaccine, and that each disease, being itself a special entity, having its own characteristics, must be dealt with along special lines. These discoveries were largely empirical, and the explanations of their mechanism are now only of historic interest. It was not until 1883, when Metchnikoff shed light upon the problems of immunity by making a series of remarkable studies on the role played by certain of the body-cells in overcoming infection, and the part they played in the processes of immunity in general, that the world was given a glimpse into the dark problems of immunity. These observations were soon followed by investigations showing the importance of the body fluids, and since that time a great deal of work has been done upon these subjects. As a consequence, a large amount of data of a wholly new order has accumulated, accompanied by the introduction of a host of new terms expressing diverse views and theories advanced by individual workers. Of the many theories advanced from time to time to explain the phenomenon of immunity, two have claimed the most attention: one ascribes protection and cure to the activity of certain body-cells; this is known as the cellular theory; and the other attributes these qualities to the bodyfluids — the humoral theory. The chief exponent of the former is Metch- The earlier hypotheses advanced by various investigators are now only of historic interest, as in the light of subsequent discoveries and observations they have failed to offer adequate explanations. Pasteur's own theory and explanation of the mechanism of acquired immunity sought to show that the microorganisms living in the infected animal used up scvme substance essential to their existence, so that, for lack of proper nourishment, the microorganisms were eventually forced to retire, the soil being unfit for further occupation. This was known as the "exhaustion theory" Chauveau considered it more probable that the microorganisms, after having lived in the body of an infected animal, produced substances that, accumulating in the blood, had an inhibitory action on the bacteria and were inimical to their further existence. This was known as the "retention theory," and in some particulars was just the opposite of the exhaustion theory. THE THEORY OF PHAGOCYTOSIS In 1883, when Metchnikoff showed that certain of the body-cells, and, particularly, the polynuclear leukocytes, were active in the defense of the human body against invasion by microparasites, real light was thrown upon the unknown problems of immunity. Although he has since amplified his theory, as new theories were adduced to describe the part played by the body-fluids and the organisms themselves, yet his theory of phagocytosis remains a demonstrable fact, and establishes the important role of cells in the processes of immunity. According to this theory, certain of the body-cells are able to ingest an infecting parasite, a red corpuscle, or other cell in the same manner as an ameba ingests a food-particle, and to dispose of it by intracellular digestion through the agency of ferments known as "cytases. " To such cells Metchnikoff applied the name phagocyte, as he likened them to scavengers, i. e., they were concerned in picking up and disposing of offensive material, both living and dead. Various body-cells are capable of becoming phagocytes. The polynuclear leukocytes are particularly active in acute infections, and have been called microphages. Endothelial cells, mononuclear leukocytes, tions and have been designated macrophages. Although the original explanation of phagocytosis was quite plain and far reaching, subsequent discoveries by the adherents of the " humoral theory" showed the potent influence of the body-fluids upon the process. It was demonstrated that without the aid of these fluids phagocytosis is almost negligible. Metchnikoff early recognized this fact, and sought to explain the influence of the body-fluids by assuming that they contained " stimulins, " or substances that stimulated phagocytosis. It was likewise shown that the body-fluids contained antibodies and were antibacterial, independent of cells. Metchnikoff recognizes the existence of these conditions, but claims that they are duetto the soluble products of phagocytic cells, and thus in a broader sense would maintain the importance of his phagocytes. It was soon observed that in certain infections leukocytes or other cells, instead of being attracted toward the seat of infection by some unknown chemical stimulus, (positive chemotaxis), were repelled, or at least the attraction was counterbalanced or did not exist (negative chemotaxis). While a satisfactory explanation of these phenomena is still lacking, it may be stated that, in general, the degree of negative chemotaxis is in proportion to the virulence of the microparasite. In 1903 Wright and Douglas, and Neufeld and Rimpau threw considerable light upon this subject. They demonstrated experimentally that one action of the body-fluids was directed against the microorganisms, lowering their resistance, and, making them, as it were, more attractive to the phagocytes, the process of phagocytosis was. facilitated. To these substances the name of "opsonins" (from opsono, I prepare for) was applied by Wright, while Neufeld called them "bacteriotropins." The leukocytes are not, however, entirely passive and willing to wait until their prey is weakened and fully prepared for their attack. In the presence of an infection they are found to increase, and this leukocytosis is known to be a valuable addition to the defensive forces. They probably also undergo qualitative changes, which increase their antibacterial power. It has been shown that opsonized bacteria attach themselves to the protoplasm of the leukocytes, a physiochemical phenomenon that occurs regardless of whether the leukocyte is dead or alive, although, of course, only the living leukocyte is able to ingest them. That phagocytosis is a potent and very important factor in the mechanism of recovery from certain infections is generally admitted, and although it probably has not the far-reaching significance originally attributed to it, yet, throughout the discussion of immunity the importance of the phagocyte itself is emphasized. This theory of Metchnikoff is treated more fully in the chapter on Phagocytosis. The humoral theory of immunity, which would ascribe the power to resist infection to the body-fluids, may be said to have had its origin in 1896, when Fodor discovered that the blood of the rabbit will kill anthrax bacilli in the test-tube, independent of cells and phagocytosis. Later Buchner adopted this theory, and sought to explain the bactericidal action of blood-serum as dependent upon a special constituent which* he called alexin. With the discovery, in 1890, of antitoxins by von Behring and Kitasato, the theory received fresh support, and while an effort was made to demonstrate that antitoxins were of paramount importance in acquired immunity, evidence soon accumulated to show that this antitoxic power is operative only in a few diseases, chiefly in diphtheria and tetanus. Fresh support to the "humoral" as against the " cellular" explanation of immunity was given by Pfeiffer in 1894, with the discovery that cholera vibrios introduced into the peritoneal cavity of a guinea-pig previously immunized against cholera became transformed into granules, and ultimately passed into complete solution (bacteriolysis), apparently without the aid of cells. Bordet then showed that this phenomenon was due to two distinct substances — one, the "sensitizing substance," which is specific and exists only in the immune serum, acting only on the bacteria against which the animal was immunized, and the other a nonspecific substance, found in the fresh serum of practically all animals, and to which he gave the name "alexin," and which was later renamed by Ehrlich and called "complement." Of the various theories offered in explanation of these observations, the suggestive, fascinating, though highly hypothetic theory of Ehrlich, known as the side-chain theory, has been most widely accepted and adopted to explain new discoveries as they were made. The theory has, indeed, aided investigators in making new discoveries. Nevertheless the contention of Bordet, that its too ready acceptance without sufficient convincing proof has retarded investigation, should not be ignored. Ehrlich asserts that a cell has two important functions: The first is the special physiologic function, as that of a nerve-cell to conduct; of a gland-cell, to secrete, etc. The second function is that of nutrition, and presides over the processes of waste and repair. Furthermore, each of the molecules composing the complex cell is believed to possess these two functions, i. e., one is concerned with the special function of the molecule, and the other, the more important functional portion, is concerned in the nourishment of the molecule. The second portion, or that concerned with nutrition, is of more importance in relation to the problems of immunity. Ehrlich conceives this as consisting of a special executive center or main portion ("Leistenkern"), in connection with which there are nutritive sidechains, receptors, or haptines ("Leitenketter"), which "seize," or rather enter into chemical combination with, suitable food atoms, which is followed by a sort of digestive or absorptive process, whereby the food material is incorporated in the molecule. The function of "seizing" molecules of food from the surrounding tissues implies a selective action or chemical affinity between food atoms and the portion of a cell or side-arm for which it has a chemical affinity, for we cannot conceive that all atoms that circulate in the blood and lymph are suitable for all cells at all times. The food molecule in the fluid surrounding the cell is conceived as possessing a special or haptophore portion for union with the side-arm of a cell molecule, and when brought into relation with one of the sidearms or receptors of the cell molecule, the two are "anchored," or unite, just as a key fits a lock. The second stage involves a process that may be compared to digestion, by which the food material is prepared and absorbed, in whole or in part, into the molecule of protoplasm. These processes, therefore, are conceived as being chemical rather than physical, and our diagrammatic representations of them have no necessary or actual morphologic basis. One is quite likely to regard the main central portion as the nucleus of a cell, and the side-arms as small morphologic projections resembling the prickles of certain epidermal cells. These processes are concerned with each molecule of a cell, the main portion, or " Leistungskern, " being conceived as diffusing through the nutritive part of the molecule, and the side-arm receptors, or "Leitenketter," as numerous atoms or groups of atoms, each of which has a chemical affinity for some particular food-substance circulating in the body-fluids, and necessary for the life of the molecule in question. toxins and the production of antitoxins. It assumes that the side-arms to a cell molecule are exceedingly numerous, not only because nutritive substances are varied, but because special cells also possess different and special side-chains, which anchor pathologic material. When infection occurs, and in addition to toxins the physiologically normal substances are brought to the cells, they likewise find suitable receptors in practically all or certain cell groups, and become anchored, causing more or less damage to the cells. Having combined with the side-arms or receptors of a cell, the toxin may be sufficiently potent to kill the cell, and if a large number of cells are so injured, symptoms of disease present themselves and death of the infected host may follow. On the other hand, although the cell has lost one or more of its side-arms, it may not be dead, and it proceeds at once to repair the damage done. According to Weigert's "overproduction theory/' nature is lavish in its processes of repair, and the cell not only replaces the lost receptors, but produces them in numbers; the excess receptors, having no space for attachment to the cell, are thrown off into the blood-stream. Each of these cast-off receptors or haptines possesses the same structure as the original receptor. These free receptors, then, are capable of combining chemically with their antigen, neutralizing the antigen and rendering it innocuous. In diphtheria and tetanus the antigen is largely the soluble toxin of the bacilli, and the antitoxins are these cast-off receptors produced as a result of the stimulating action of 'the toxins upon the cells. This excess of receptors is made by repeatedly injecting a horse with increasing doses of diphtheria toxin. By injecting this receptor-laden (antitoxin) serum into one suffering from diphtheria, the receptors unite with free diphtheria toxin and thus protect the body-cells. For the production of these receptors, or antibodies, as they are now called, it is necessary, as previously stated, that the antigen enter into chemical combination with the cell, so that the usual illustrations showing the theoretic union of antigen and side-arm by physical contact alone probably do not correctly portray what actually occurs. As Adami points out, the antigen probably enters into intimate relationship with the cell, and the continued stimulation of its presence is responsible for the production of an excess of receptors, in addition to the overproductive tendencies of nature's repair. It is also necessary that the antigen possess sufficient toxic power at least to stimulate the cell, for otherwise antibodies may not be produced. Food material, for instance, being physiologic, is assimilated by the cells without stimulating the production of antibodies, as otherwise the food would be attacked by cast-off receptors and rendered useless before it reaches cells, the process ending in starvation and death. The host in whom certain cells with special receptors for a given poison are present will make use of these, no matter how the pathologic agent is introduced. This affinity is well illustrated in tetanus, where the effects produced are dependent to a large extent upon the selective affinity of the toxin for nerve-cells. THE THREE ORDERS OF RECEPTORS AND CORRESPONDING ANTIBODIES First Order: Antitoxin and Simple Antiferments. — The simplest receptor of the cell molecule is composed of a single arm or haptophore, for union with the haptophore portion of a food molecule. As previously stated, a molecule of toxin is conceived as being composed of two portions— one, the haptophore, for union with the side-arm or receptor of a cell molecule, and the second, the toxophore, in which its toxic action resides. The first stage of intoxication of a cell produced by a true toxin consists in the union of the haptophore portion of the toxin molecule to a receptor or side-arm of the cell molecule, this receptor being one that fits the toxin molecule "like a key fits a lock." Each molecule of the body-cell has innumerable receptors, of which only a certain number are suitable for a particular toxin. The toxin molecule is now anchored to the living cell, and, as animal experiments with a great number of toxins show, this union is a firm and enduring one (Fig. 39). So long as the union lasts the side-chain involved cannot exercise its normal nutritive physiologic function — the taking up of food-stuffs. Furthermore, the toxophore group of the toxin molecule may now exert an injurious, enzyme-like action on the protoplasm of the cell, with the result that the protoplasm is poisoned. If only a few of the cell receptors are united with toxin molecules, or if the toxin is of low toxicity, the effects on the cell may be slight. If more are joined to the molecule or the toxin is highly poisonous, the whole molecule, and finally the cell itself, may be greatly disturbed, and produce marked symptoms, or the host may be destroyed. Since the receptors joined to the toxin molecules are incapacitated or destroyed, the damage is repaired by the regeneration of new receptors. According to the reparative principles worked out by Weigert, the repair is not a simple replacement of the defect — the compensation proceeds far beyond the necessary limit; indeed, overcompensation is the rule, and this forms the basis of Ehrlich's theory. If, after repair has taken place, new quantities of toxin are administered at proper intervals and in suitable quantities, the side-chains that have been produced by the regenerative process are taken up anew in combination with the toxin, and so again the process of regeneration gives rise to the formation of fresh side-chains. "The lasting and ever-increasing regeneration must finally reach a stage at which such an excess of side- r, A receptor of the molecule (first order] ; A, overproduction of receptors, which are being cast off; A2, a cast-off receptor free in the body-fluids — now an antitoxin; A3, a molecule of antitoxin combination with a toxin molecule T3. A% a cast-off receptor still within the parent cell; T, a toxin molecule in combination with the receptor of a cell molecule; T2, a toxin molecule free in the body-fluids; T3, a toxin molecule in combination with antitoxin; T4, a molecule of toxoid (toxophore group lost). chains is produced that, to use a trivial expression, the side-chains are present in too great a quantity for the cell to carry, and are, after the manner of a secretion, handed over as a needless ballast to the blood. Regarded in accordance with this conception, the antitoxins represent nothing more than side-chains reproduced in excess during regeneration, and therefore pushed off from the protoplasm and so coming to exist in the free state" (Ehrlich). This theory explains the specificity of the antitoxins for a given toxin; thus the latter causes specific chemical stimulation of the cell, which induces the formation of specific side-chains, — the cast-off receptors, — which are capable of uniting with the toxin molecules free in the body-fluids and thus neutralizing them; they are, therefore, called antitoxins. This theory also explains why a minute quantity of toxin is capable of stimulating the production of a large amount of antitoxin, and why the production of antitoxin persists for some time. The toxin molecule must be conceived as entering into the protoplasm of a body molecule and residing there for some time, acting as a stimulus to the cell, with consequent production of antitoxin. Diagrammatic representations of this process would seem to show that a physical union exists between toxin and cell receptors, resulting in the destruction of receptor, which drops off and is replaced by a number of receptors that, for lack of space for attachment to the the body become converted into cells that .secrete AN^ToxoiD°XIN specific antitoxin, and, as shown by Salmonson and 1, Toxin: H, Madsen, the administration of pilocarpin, which remains nearly constant. In the production of antitoxin the haptophore group is the essential and important portion of the toxin molecule. Even though the toxophore group is lost, — and when this occurs the toxin is called toxoid (Fig. 40), — the haptophore group is capable of uniting with receptors and stimulates the production of antitoxin. In fact, in effecting immunization with powerful toxins it may be necessary, in the first few injections that are given, to convert artificially all or a portion of the toxin into toxoid, so that antitoxins will be produced that will protect the animal against subsequent overdoses of toxin. The production of antitoxins must, in keeping with this theory, be regarded as a function of the haptophore group of the toxin. It is easy, therefore, to understand why, out of the great number of alkaloids, none is in a position to cause the production of antitoxins, for alkaloids possess no haptophore group that anchors them to the cells of organs. As has been stated, in the formation of antitoxin the haptophore group of the toxin molecule is the essential portion; the toxophore group is much less important, and during immunization the symptoms of illness due to the action of the latter group are not essential to and play no part in the production of antitoxin. It must be said, however, that a toxin molecule with an intact toxophore group is more stimulating than a toxoid in which this group is absent; therefore, in artificially immunizing horses for the production of antitoxin, after the first few injections increasing amounts of toxin are administered. Antibodies of the Second Order (Agglutinins and Precipitins).— As new discoveries were made, Ehrlich amplified his theory of the formation of antibodies, but always upon the original and basic conceptions as just set forth. We have seen that the simplest molecules of food substances, toxins, and ferments, substances really in solution, are anchored to molecules of cell protoplasm by means of the simple side-arms of the latter. When this chemical union has taken place, the food or toxin may be assimilated without undergoing any further change. With more complex food substances, however, some preparatory treatment is necessary before they become available for final assimilation. The large molecule may readily enough be anchored to the molecule of the cell, but it probably requires some preparation before it becomes available for the nutrition of the cell. Accordingly, Ehrlich assumed that the body-cells are furnished with another order of side-chains or receptors composed of two portions; one part or group for union with the food substance, and called the haptophore group; and the second portion, called the toxophore or zymophore group, in which the special function of the receptor resides. Similarly, certain pathogenic agents that are more complex than soluble toxins or ferments combine with receptors of this kind. One arm, the haptophore group of the receptor, combines with the haptophore portion of the pathogenic molecule, and then the second or toxophore portion of the receptor exerts some special action upon the attached molecule. Receptors or haptines of this nature are known as receptors of the second order; antibodies of the same structure, produced and cast off into the blood-stream as the result of toxic injury and stimulation of body-cells, are known as antibodies of the second order. Two such antibodies are well known. In one we find that the toxophore group of the antibody causes clumping or agglutination of its antigen, or the agent that caused its production, and hence this antibody is called an agglutinin. In typhoid fever, for example, the bacillus or one of its more complex products causes the production of an antibody of this nature, so that when the serum of a typhoid fever patient is mixed with the bacilli, the latter lose their motility and form clumps or agglutinated masses. This phenomenon was first observed by Gruber and Durham, and was applied in a practical way to the diagnosis of R, Receptor of the molecule (second order)] R2, overproduction of receptors, which are being cast off; A, a cast-off receptor which now constitutes the antibody; A, A2, agglutinins in combination with the antigen (bacilli). typhoid fever by Widal and Griinbaum. The second antibody of this class, the precipitins, resemble the agglutinins quite closely (Fig. 41). Kraus discovered that if a bouillon culture of the typhoid bacillus is filtered through porcelain, and a few drops of serum from a typhoid fever patient or from an animal immunized by injections of typhoid bacilli are added to a small quantity of the bacilli-free filtrate, a faint cloud will appear resembling in some respects that observed at the line of contact between nitric acid and urine that contains a trace of albumin. The toxophore portion of this antibody, therefore, appears to coagulate or precipitate soluble substances, and, accordingly, the antibody is known as a precipitin. As will be pointed out later, various protein substances, such as blood-serum, milk, egg-albumin, etc., may cause the production of specific precipitins. Antibodies of the Third Order (Hemolysins, Bacteriolysins, Cytotoxins). — Still more complex molecules of food material require conversion into simpler substances before they may be assimilated by the molecules of the cell. It is essential that they undergo a sort of digestion, and accordingly Ehrlich has conceived that special side-arms or receptors exist for this purpose, these being composed of two grasping portions, or haptophore groups, one for union with the complex food molecule, the second for union with a special, ferment-like substance present in the blood and called complement. The receptor, therefore, acts simply as a connecting link or interbody between food molecule and complement, bringing the two into relation with each other when the food molecule is rendered soluble, i. e., undergoes lysis. With highly organized cell material, such as red blood-corpuscles or bacteria, it is found that receptors of this nature bring about their destruction by lysis by attaching them to a suitable complement. During infections with various bacteria, therefore, we find that numerous antibodies are produced. If the bacteria produce soluble toxins, specific antitoxins are produced to counteract the effects of these; other products stimulate the production of agglutinins and precipitins ; still other products or the whole cell cause the production of antibodies, which are not in themselves destructive; but which have the specific power of combining with the cell and bringing about its lysis or destruction by bringing it into relation with the ferment-like complement. It is only by means of a special antibody of this nature that a complement may be united with the pathogenic agent, i. e., the complement itself cannot act directly upon the cell, but must be united by means of the antibody. Ehrlich has termed an antibody of this nature an amboceptor, or interbody. In structure, amboceptors are believed to possess two combining or grasping portions: one, the haptophore or antigenophore group, for union with the cell; the other the complementophile group, for union with a complement (Fig. 42). The lysins (bacteriolysins, hemolysins, and other cytolysins) are antibodies of this order. If, for example, the erythrocytes of one animal are injected into an animal of a different species, hemolysins will be produced, the hemolysin being a specific hemolytic amboceptor that will unite corpuscles of the animal used in the injection and only these cells, with a complement, and thus bring about their solution or lysis. If certain bacteria (e. g., the cholera bacillus) are injected into an animal, specific bacteriolysins (bacteriolytic amboceptors) will be produced. Similarly, specific amboceptors are produced during the course of infections with typhoid bacilli, and are largely instrumental in combating and overcoming this infection. It is important to remember, however, that although these amboceptors probably prepare their antigens for R, Receptor of the molecule (third order) ; R2, overproduction of receptors, which are being cast off; A, a cast-off receptor which now constitutes the antibody or amboceptor; C, molecule of complement free in the body-cells and body-fluids; A2 A4, amboceptors in combination with molecules of a cell (antigen) and a complement; A3, an amboceptor in combination with a molecule of a cell. The cell (antigen) is now said to be sensitized. Lysis does not occur because a complement is not united. lysis, or, in the meaning of Bordet, " sensitize" them, they are not in themselves lytic, final solution of the antigen being accomplished by the ferment-like substance — the complement. one set of phenomena viewed from different aspects. Since its original announcement, Metchnikoff has, on different occasions, enlarged upon his theory to meet certain discoveries, made chiefly by adherents of Ehrlich's theory, showing the presence of substances in the blood-serum and other body-fluids that are potent in the processes of immunity independent of cells. Metchnikoff claims, however, that these antibodies are derived from the group of cells classified as phagocytes, and thus would preserve the primary importance of his theory. Ehrlich, on the other hand, while not denying that these cells may be a source of their formation, points out that they are not necessarily the sole or supreme source, but may be formed by the general body-cells or by special groups of cells possessing a selective affinity for the'pathogenic agent. The theory of Ehrlich is essentially a chemical one, and maintains that the union of food or pathologic material with cells is a chemical union; his views, therefore, possess that degree of definiteness necessary to constitute a plausible chemical theory. The theory of Metchnikoff would explain processes of nutrition and immunity as largely founded on a physical basis, and is therefore, necessarily more general, being largely biologic and vitalistic. The two theories differ in two more or less hypothetic points: (1) In the manner by which material enters into relation with cells, and (2) the relative importance of certain cells in the formation of antibodies. Otherwise both are intimately related, in that phagocytosis is unimportant if removed from the influence of antibodies in the bodyfluids, and these same antibodies, although probably formed according to Ehrlich's theory, are derived in part from Metchnikoff's phagocytes. Phagocytosis, whether by leukocytes, endothelial cells, or by newly developed connective-tissue cells, is very common, and is obviously a most important factor in the destruction of pathogenic bacteria and in the cure of infectious disease. In virulent infections, however, phagocytosis may not be apparent; the leukocytes are not attracted, and those in the vicinity undergo dissolution. Later in these infections, however, phagocytosis may become apparent, due, according to Metchnikoff, to the " adaptation" of the cells to the products of the invading microorganism, whereby the weak or negative chemotaxis is converted into an active positive chemotaxis with vigorous digestion. This, however, is not primarily due to increased digestive capacity of the phagocytes, the bacteria for digestion. The original phagocytic theory did not explain the destruction of bacteria within the living tissues without the intervention of leukocytes, and, what is even more striking, a similar destruction occurring in vitro by serum and other body-fluids totally devoid of cells. Bacteriolysis has been shown to be due to two different substances — one, a thermolabile, ferment-like body called "cytase" by Metchnikoff and " complement" by Ehrlich, and the other a more specific thermostabile body called "fixateur" by Metchnikoff and "amboceptor" by Ehrlich. These substances appear to play an important role in certain infections, as, for example, in typhoid fever and cholera, and were studied mainly by the adherents of the side-chain theory. Metchnikoff recognized their existence and significance, but endeavored to preserve the primary importance of the phagocytic theory by claiming that they are products of the group of cells classified as phagocytes. Ehrlich, however, while not denying that these cells may be one source, holds that they are not necessarily the sole source, but that they are products of general cellular activity or of special groups of cells that have shown a combining affinity for the antigens. For example, Metchnikoff holds that there are but two complements,— macrocytase and microcytase, — and that these are formed by destruction or solution of macrophages and microphages. Ehrlich has shown quite conclusively that there are many complements, and that these are the excretory products of leukocytes, and probably of other cells as well. Ehrlich teaches also that specific amboceptors or fixateurs may be products of various body-cells other than those classified as phagocytes, and Metchnikoff recognizes their existence, but holds that they are formed and discharged solely by the leukocytes or other phagocytic cells. Ehrlich has shown the manner in which complement and amboceptor produce bacteriolysis, and Metchnikoff has amplified his theory to meet these observations, to the extent that destruction of bacteria is recognized as being brought about either intracellularly, by the digestive action of the leukocytes, or extracellularly, by the enzymelike action of the cytase, or complement, working through the intermediation of the fixateur or amboceptor, and that cells that are potentially phagocytic give origin to these antibodies. Regarding the structure of toxins and the action of antitoxins the two theories are divergent, and whereas Metchnikoff is inconclusive, Ehrlich presents definite conceptions that are well supported by experi- mental data. Metchnikoff maintains that it is the cells that absorb the "toxin" that furnish the antitoxin. In other words, the enzymes, as microcytase and macrocytase, exert their action not only upon the more complex molecules of microorganisms, but also upon their simpler toxins, fixing or otherwise altering them until they can finally be destroyed. This explanation would lead us to conclude that the nervecells which bind the tetanotoxin are capable of furnishing antitoxin, whereas experimental observations are absolutely opposed to this narrower view. Metchnikoff also maintains that antitoxin acts by stimulating the leukocytes to absorb and destroy toxin, whereas Ehrlich has clearly shown that antitoxin, by combining chemically with the toxin, neutralizes it, a process that may be shown in vitro entirely independent of cells. From what has been said it will be seen that the two theories are not essentially divergent, and that we are unwarranted in clinging to one view to the absolute exclusion of the other. The question rests largely on which of the body-cells are most active in forming antibodies, and also on a recognition of the role played by phagocytosis in certain infections, such as staphylococcus, streptococcus, and pneumococcus infections. Ehrlich has attempted an explanation of the method by which body-cells form antibodies, and the manner in which these antibodies overcome their antigens; he has placed both processes upon a chemical basis, involving no one particular group or class of cells. Metchnikoff, on the other hand, has shown the important role played by phagocytosis in many infections, and claims that the antibodies in the circulating fluids are the products of these phagocytes; he places immunity more largely upon a physical basis. The various phenomena of immunity cannot be ascribed either to the activity of the body-cells or to the body fluids alone, to the total exclusion of the other — both are intimately concerned in the various phases of immunity. It is, moreover, becoming more obvious that too little attention has been paid to the influence of the microorganism in the phenomena of immunity reactions. It is important to recognize that some bacteria are apparently able to immunize themselves against the combative forces of their hosts, as is demonstrated by the manner in which streptococci and pneumococci protect themselves with a capsule and resist phagocytosis. Virulent strains and "resistant races" may be evolved in this manner. This has been demonstrated by Ehrlich with regard to the action of various arsenical compounds on protozoa, work that ANTIGENS 161 finally culminated in the brilliant discovery of salvarsan. Thus atoxyl may not kill all the trypanosomes in an infected animal, those escaping acquiring a new power of resistance to the poison and become atoxylresistant. The production of " resistant races," not only among the protozoa, but also in the class of bacteria, complicates enormously the practical problems of immunity. So far as is now known, antigens are colloids, and are usually protein in nature. Every known soluble protein may in some degree act as an antigen, and recent investigations would seem to show, although they do not definitely prove, that toxic glucosids and various lipoids may to some extent act in this same capacity The protein antigens may be quite varied: thus antibodies are produced not only by the injection of bacteria or their toxins, but also by erythrocytes, serums of different animals, egg-albumen, milk, etc. Of the cleavage products of proteins, it is certain that none of the amino-acids and simple polypeptids can act as antigens; there is, however, some evidence to show that the proteoses possess antigenic properties. It has been shown by Gay and Robertson1 that if the antigenic cleavage products of casein are resynthesized by the reverse action of pepsin into a protein resembling paranuclein, this synthetic protein is capable of acting as an antigen. Protamins and globin were found to be non-antigenic, although globin combined with casein formed a compound of antigenic power in that it produced an antibody yielding complement-fixation reactions with globin. Whether the entire protein molecule, or only groups thereof, determine the characteristics of the antigen and the antibody is not definitely known. Wells and Osborne2 have recently submitted evidence showing that a single protein molecule can act as an antigen and produce more than one antibody. Non-protein Antigens. — Ford3 was able to immunize rabbits by injecting a toxic glucosid contained in extracts of Amanita phalloides, producing an antibody antihemolytic for the hemolysin of Amanita when diluted 1 :1000. Abderhalden and others have, found that specific % enzymotic substances appear in the blood of animals injected with car- bohydrates and fats. Recent developments in immunologic research would indicate, therefore, that a complex toxic glucosid that can be hydrolyzed by enzymes may act as an antigen. The intimate relationship of lipoids to complement fixation reactions, especially in syphilis, has naturally led to investigations regarding the possibility of lipoids acting as true antigens. In testing for the Wassermann reaction the use of lipoids in the form of tissue extracts to serve as an antigen does not mean that it is a true antigen; in fact, experimental work indicates quite strongly that these lipoidal substances are incapable of producing antibodies when injected into animals. Much and others have worked with lipoids secured from a streptothrix, and which is called "nastin," and they assert that this substance may be used in immunizing animals with the production of an antibody yielding complement fixation, with nastin as the antigen. Similar results have been described for the fatty substances from tubercle bacilli ("tuberculonastin"). Kleinschmidt l accepts the antigenic 'nature of nastin in reactions, but was unable to secure antibodies by immunizing rabbits with this substance. Ritchie and Miller2 could demonstrate no antigenic activity in the lipoids of serum or corpuscles. Thiele3 calls attention to the fact that lipoids possess no specificity, and that they cannot act as antigens with the production of antibodies. On the other hand, Meyer 4 has reported the production of specific complement-fixation antibodies by immunizing rabbits with acetone-insoluble lipoidal substances obtained from various teniae. He has also found the acetone-insoluble fraction of tubercle bacilli to serve as antigens in complement-fixation reactions with antibodies of the tubercle bacillus, and much more effectively than with the protein residue of the bacilli. Beigel5 has observed that after injecting lecithin in rabbits an increase occurs in the lipase content of the blood and tissues, with the presence of complement-fixing antibodies, and Jobling and Bull6 have found an increase in serum lipase after immunizing with red corpuscles. It will be noticed, therefore, that the results of various investigations regarding the true antigenic properties of lipoids are not in accord. It should be emphasized that the complement-fixation reaction does not constitute a reliable index to the study of this problem, as so little is ANTIBODIES 163 understood of the actual nature of this reaction itself. That lipoids serve a very important purpose in the absorption or fixation of complement in vitro, as is so well demonstrated in Wassermann's reaction for syphilis, is undoubtedly true, but this does not indicate that the antibody in the blood-serum of syphilitics is in the nature of a true lipoid antibody, and, indeed, investigation on this subject would seem to indicate that it is not.1 It will be understood, therefore, that the question of substances other than proteins acting as true antigens must be regarded as an open one, requiring further investigation. The relation of proteins, however, to the production of antibodies has been fully established, and is at present receiving renewed attention through the researches of Vaughan and his coworkers and Abderhalden. As has been stated in a previous chapter, Vaughan regards the protein constituents of bacterial and other cells as the main antigenic principle capable of causing the production of specific proteolytic ferments, which split the new bacterial protein, releasing a toxic product responsible for the symptoms and lesions of the infection. Abderhalden has also demonstrated the presence of proteolytic ferments in the blood-serum after experimental immunization with proteins, and in the serum of pregnant women, due to the antigenic stimulation of syncytial cells, capable of splitting their substrata in vitro into aminoacids and other simple cleavage-products. These investigations serve to show the intimate relation that proteins bear to the problems of infection and immunity, and demonstrate that antibodies may be largely in the nature of ferments, and that immunologic reactions, both in the living tissues and in the test-tube, are largely in the nature of disintegrative enzymic processes. The term antibody is used to designate the specific bodies produced by the cells of a host in reaction against an antigen, as an infecting microparasite and its products or other foreign protein. Various kinds of antibodies may be produced by the same antigen and by different antigens. Some neutralize the soluble toxin of the antigen (antitoxin); others agglutinate or precipitate their antigens (agglutinins and precipitins) ; . still others cause complete dissolution of the antigen (hemolysins, bacteriolysins, etc.), and others again may so alter the antigen and lower its resistance as to render it more easily phagocytable by the body-cells (opsonins or bacteriotropins) . Tissues Concerned in the Production of Antibodies. — A large amount of experimental work has been conducted in the study of the problem of where in the body the antibodies are formed that develop in response to immunization. The recent investigations of Hektoen and Curtis,1 who studied the effect on antibody production of the removal of various organs, and of Hektoen2 and Simonds and Jones,8 on the influence of exposure to z-rays, and of Simonds and Jones,4 on the effect of injections of benzol, indicate that the mechanisms concerned for the production of antibodies are quite secure from certain disturbances and are principally located in the leukocytes and blood-forming organs, as the spleen, lymphatic tissues, and bone-marrow. Specificity of Antibodies. — Antibodies are usually specific for their antigen, and it is upon this general law that the reactions of immunity are based. It should be remembered, however, that not all antibodies are protective; the agglutinins, for instance, apparently do not injure their antigen. On the other hand, an animal may enjoy an immunity without demonstrating the presence of any antibody in the body-fluids, and another animal may show antibodies generally considered as possessing protective powers, as, for example, the bacteriolysins, without necessarily being immune. Upon what does the specificity of antibodies and immunologic reactions depend? Specificity was at first believed to depend solely upon some peculiar biologic relationship of the antigens, for it was found comparatively easy to differentiate the serum of animals of dissimilar nature by means of the precipitin and other reactions, and, as serum proteins, which seemed to be quite similar chemically, but which were obtained from unrelated species, were sharply differentiated by the biologic reactions, it was considered that the specificity must be dependent upon some principle quite apart from the ordinary chemical substances. With the use of proteins other than serums, and especially when more or less purified proteins were employed, it has been quite firmly established that specificity depends upon chemical composition, and that differences in species, as exhibited by their biologic reactions, depend upon distinct differences in the chemistry of their proteins (Wells). Pick and his coworkers have shown that two kinds of specificity exist in each protein molecule: (1) One of these is easily changed by various physical agents, such as heat, cold, and partial coagulation. When an antigen is altered by heat, it produces an antibody that reacts best with the heated antigen; heating does not, however, destroy the characteristics of the antigen of this species, as its antibody will not react with the heated antigen of another species. (2) The second alteration involves a profound chemical change ,of the antigen, whereby it is so altered that it loses the characteristics peculiar to the species, and produces an antibody that will react with the altered antigen, but not with the unaltered antigen, even from the same animal. For example, it is possible so to alter the serum protein of a rabbit by treatment with nitric acid that the nitroprotein injected back into the same rabbit will produce an antibody specific for the nitroprotein, but which does not react with the unchanged serum protein. These changes are apparently closely related to the aromatic radicals of the protein antigen, for they Antitoxins and antif erments : R, Receptor of a molecule of a cell; T, a toxin molecule; t, toxophore group of the toxin molecule; h, haptophore group of the toxin molecule; A, cast-off receptor and constitutes antitoxin. Agglutinins and precipitins: A. R, Receptor of cell with antigen attached; B, a bacterial molecule (antigen) attached to a receptor; A. or P, an agglutinin or pnecipitin; h, haptophore group of the antibody; a, agglutinophore group of an agglutinin. complement. are effected by introducing into the protein molecules substances that are known to combine with the benzine ring, e. g., iodin, diazo- and nitrogroups. Pick, appreciating the fact that the number of different aromatic radicals in the protein molecule are limited, interprets the significance of these radicals as depending upon their arrangement, rather than upon their number, in the protein molecule. Granting the number of possible variations in the arrangement of the amino-acids in a protein molecule which the great number of these radicals provides, there is no difficulty in understanding the possibility of an almost limitless number of specific distinctions between proteins. It may be stated, however, in general, that immunologic reactions, such as that of anaphylaxis, are as delicate in distinguishing between proteins as are chemical analyses. Distinctions may be made by these reactions with quantities too small for making accurate chemical determinations. In succeeding chapters we shall consider, first, the different kinds of immunity, as dependent upon the presence of various factors, and then the role played by the phagocytes and the body-fluids in immunity, with a more detailed consideration of the various antibodies. It may be useful here to draw up in tabular form a list of the various antigens and antibodies with which we are mainly interested in that portion of immunity involving infection with vegetable or animal parasites, and the products of their metabolism or degeneration (Fig. 43). THE VARIOUS TYPES OF IMMUNITY As has been stated in the preceding chapter, it is generally agreed that various antibodies and other protective agencies exist, although opinions differ as to the source and relative importance of these to resistance to and recovery from various infections. Whether or not a particular antibody is derived from a certain group of cells is largely a matter of individual opinion, because of the difficulty of deciding the point by actual experimental evidence. Of far more importance is a knowledge of the properties of antibodies and of the role they may play in the processes of immunity. It is seldom that resistance to, or recovery from, an infection is dependent upon one defensive factor: usually several agencies are operative, although one factor may predominate. For example, antitoxins are known to neutralize their respective toxins, and are of most value in combating the toxemias, such as diphtheria and tetanus; bacteriolysins cause the death of and may totally destroy their antigens, and play an important part in the recovery from infections with bacilli of the typhoid-colon and cholera groups; phagocytosis in itself is of importance in staphylococcus infections, and is of primary importance, in conjunction with the opsonins, in recovery from pyogenic infections in general; agglutinins and precipitins do not appear to have a direct inimical influence on their antigens, but are probably secondary factors, and contribute in some manner toward their destruction. Along with important non-specific factors, these various antibodies are responsible for the different forms of immunity, which may now be considered in their more general aspects. the nature of the infecting parasite, and the presence or absence of specific antibodies in the body-fluids. In many instances this type of immunity is dependent upon non-specific causes — is frequently relative and seldom absolute. For example, fowls are immune to what may be called an ordinary dose of tetanus toxin, but succumb readily to larger doses; rats are highly immune to diphtheria toxin, and readily withstand the effects of an amount equaling 1000 lethal doses for a guinea-pig, but still larger doses may prove fatal; hedgehogs possess complete or almost complete immunity for the amount of snake venom deposited in an ordinary strike, but if the venoms of several snakes are collected and injected at one time, the result is fatal. Species immunity is a type of natural immunity, best illustrated by the immunity of man to certain diseases of the lower animals, such as fowl cholera, swine-plague, distemper, Texas cattle fever, mouse septicemia, etc.; and, conversely, by the immunity of animals to diseases common to man, such as measles, cholera, typhoid fever, scarlet fever, chicken-pox, etc. Although the close relation of man to the domestic animals furnishes ample opportunity for infection, yet a complete immunity is frequently observed. Racial immunity is that type of natural immunity existing among members of the same species. For example, negroes are believed to enjoy immunity to yellow fever and Mongolians to scarlet fever. As a matter of fact, well-marked examples of racial immunity are extremely rare, as not infrequently the disease in question may have been acquired in early infancy in a clinically unrecognized form. Similarly, close biologic relationship is no guarantee that animals will behave alike toward infection. For example, the white mouse is immune to glanders, the house mouse is somewhat susceptible, and the field mouse is highly susceptible. The rabbit, guinea-pig, and rat are rodents, but though the rabbit and the guinea-pig are susceptible to anthrax, the rat is largely immune. Mosquitos, though closely related, behave differently toward, the malarial parasite. The Culex does not carry the parasite at all, and of the Anopheles, one species, Anopheles maculipennis, is quite susceptible and well recognized as a carrier of the parasite, whereas Anopheles punctipennis, though closely related, is not susceptible to it. Examples of individual immunity, while not infrequent, are not constant and seldom absolute. Certain persons appear to possess a definite immunity to scarlet fever and diphtheria, although they may be freely exposed; others may pass through various epidemics of other NATURAL IMMUNITY 169 infectious diseases, such as measles, pertussis, etc., without becoming infected. I have noticed, on several occasions, that resident physicians, on service in scarlet-fever wards for many months or years, having escaped infection though brought in intimate contact with severe forms of the disease, finally contracted the disease upon returning from a short vacation. Natural immunity may be due to the following causes: 1. Various non-specific factors may prevent infection; among these may be mentioned — (a) The integrity of the epithelium of the skin and mucous membranes, and (6) the chemical and physical action of various secretions, such as the gastric fluid, the intestinal juices, and the saliva. 2. A particular route for the introduction of infecting microparasites may be necessary. For example, intestinal diseases, such as typhoid fever and cholera, are usually due directly to swallowing of the infecting microorganisms, infection in this type of disease seldom, if ever, occurring through the skin. This is probably due in part to the lowered vitality of the intestinal mucosa, together with a peculiar selective affinity of the bacteria for the cells of these tissues, aided by — (a) the biologic nature of the invading bacterium, which grows best under the more favorable cultural conditions of the intestinal canal. This selective action is further illustrated by the tendency of dysentery toxin to attack the intestinal mucosa when the bacilli or toxin is administered intravenously. 3. Certain tissues appear to possess a marked local immunity to certain bacteria. In considering examples of local immunity, various factors, such as the question of exposure, the thickness of the epidermis, and the kind and quantity of the local secretions must be borne in mind. For example, Trichina spiralis affects the muscles, never the bones, and but rarely any other tissue. Likewise, although diphtheria in the throat may spread in many directions, it seldom passes down the esophagus. Some differences are known to exist in regard to local immunity as observed in the child and in the adult. For example, ring-worm of the scalp is practically unknown among adults, whereas children under seven years of age are quite susceptible to the disease. These differences may be due to the greater susceptibility in general of young tissues to infection, and the local immunity constitutes but an index to the general rise in resisting power accompanying improvement in strength and vitality. In some cases this may be due perhaps to an actual strengthening of local tissues, as in the case of the adult vaginal mucosa, which is membrane is peculiarly susceptible. In general, our knowledge of local immunity is quite incomplete. The subject is a difficult one, hence most attention has been given to the study of general immunity. A striking example of acquired local immunity may be seen in a patch of psoriasis, where the center is observed to be largely free from scales, whereas the margins are quite active. The question of local immunity may be largely determined by various local non-specific factors, such as loss of blood supply due to traumatism, thrombosis, tight bandaging, etc., and the action of severe irritants, tending to produce necrosis of the tissues. 4. The importance of phagocytosis in natural immunity must be emphasized. Microorganisms are constantly gaining entrance to the tissues through numerous small abrasions of the skin and along the intestinal and respiratory tracts, and investigations have shown how important the wandering cells are in preventing infection, being ever on guard and ready to pick up and dispose of any injurious material. Even after mild infection has occurred, the local inflammatory reaction in which the phagocyte is a prominent factor may be so prompt in overcoming the invaders that the host will escape serious infection. disposing the bacilli. Similarly a mild irritant may produce hyperemia and exudation or local accumulation of leukocytes, which aid in establishing a local immunity largely dependent upon phagocytosis. In this manner the intraperitoneal injection of sterile bouillon or even of salt solution may produce exudation and increase the immunity to infection. 5. It may be that even after the introduction of a microorganism or its toxin no harm results because of a lack of suitable receptors on the part of the body -cells of the host for union with the pathogenic agent. For example, tetanus toxin, being unbound by the cells, produces no effect on the turtle, and antitoxin is not produced. On the other hand, suitable receptors may be present that will bind the toxin, but produce no harmful effects because the body-cells are not susceptible to the action of the microparasite or its products. Thus it is asserted that tetanus toxin has no effect upon the alligator, although the toxin is bound and antitoxin is produced by its body-cells. body-cells, so that but a small amount of harmful substances are bound to the body-cells, and no particular harm results, whereas a larger dose, uniting with a greater number of cells, is capable of producing some disturbance. 6. A natural antitoxin immunity may exist, as the immunity of the alligator to tetanus toxin, just mentioned. Similarly natural diphtheria antitoxin may prevent infection, especially in those persons known to harbor virulent bacilli in the fauces. In such instances, however, it is difficult to exclude entirely the possibility that a previous minor infection has occurred, as natural antitoxin immunity persists much longer than the passive immunity resulting from the administration of an antitoxin serum. Otto, who has recently investigated the content of diphtheria antitoxin in the blood of normal persons, found more than YW of a unit of antitoxin in each cubic centimeter of the blood of those who had been in close contact with cases of diphtheria without having been sick themselves; others usually had much less. Observations would tend to show that this quantity of antitoxin is generally sufficient to confer immunity to diphtheria, and the object of von Behring's method of active immunization is to induce the production of at least that much antitoxin by the body itself. Otto found that diphtheria carriers, both those who had had the disease and those who had not, contained more antitoxin in their blood than did patients who had just recovered from an attack. This shows that the mere presence of bacilli in the throat is sufficient to stimulate the production of antitoxin, on which the immunity of the carrier himself would seem to depend. Undoubtedly physicians and nurses who are freely exposed to diphtheria and yet escape infection owe their safety rather to an acquired immunity the result of repeated contact with the bacilli, than to a natural antitoxin immunity. 7. In some instances a natural immunity may be dependent, at least in part, upon antibacterial activity, due to the presence of bacteriolysins and bacteriotropins in the body-fluids, as, for example, that shown by the dog and the rat to anthrax. In other instances, however, a similar immunity may be observed that cannot be ascribed to the presence of antitoxins or bacteriolysins. In this type of immunity microparasites are apparently unable to sustain themselves, and proliferate in one animal, although aggressive enough in another of the same species. may be due to the presence or production of anti-aggressins. This immunity would seem to depend not upon the bactericidal properties of the serum or leukocytes nor upon the antitoxins, but on the presence of substances that prevent the microorganisms from exercising their special aggressive forces. 9. Finally, an immunity may exist because the parasite or other foreign cell does not obtain suitable nutrition in a host and thus fails to grow. This condition of^athrepsia, is responsible for what has been called athreptic immunity. It has been more recently studied by Ehrlich, who found that upon transferring mouse cancer to the rat, the tumor grew for a short time only, or presumably until the special nutriment carried over with the tumor was consumed. While there is no experimental basis for assuming that a similar condition may be present in bacterial life, yet such a cause may be operative and should be kept in mind. ACQUIRED IMMUNITY Acquired immunity occurs in two distinct forms: (1) Active and (2) Passive. A mixed form may exist, brought about by a combination of factors necessary for the development of the other two. Active Acquired Immunity. — Active acquired immunity is that form of resistance to infection brought about by the activity of the cells of a person or animal as a result of having had the actual disease in question, or as a result of artificial inoculation with a modified or attenuated form of the causitive microparasite. The essential feature of this immunity is that the cells and tissues of persons or animals should, by their own efforts, and as a result of their own active struggle against the action of a microparasite or its products, overcome these and become less susceptible to them than they were before. This form of immunity is gained, therefore, only as the result of an active struggle between body-cells and infecting agent, and this battle may be of any degree of severity, ranging from an attack of the disease itself that may threaten life, down to the most transitory and trivial reaction due to the injection of a minute dose of a mild vaccine. Active acquired immunity may be gained — (1) By accidental infection, which is the most familiar form of acquired immunity, and follows an attack of an infectious disease, such as scarlet fever, measles, varicella, variola, or typhus fever; (2) by inducing an attack of the disease by artificial inoculation. This latter method of producing an active acquired immunity was illustrated by the ancient, obsolete, and discarded practice of smallpox inoculation, by which healthy persons were inoculated with the virus of a mild case of smallpox, at a time when no epidemics existed and the person was in good general health and able to secure proper attention from the outset. This process of immunization is used much more extensively in veterinary practice, where an occasional untoward or fatal result is of comparatively little importance if by its means an outbreak can be controlled or the great majority of the animals saved. As a rule, an attempt is made to render the induced disease as mild as possible by — (a) Using a small amount of infective material; (6) by inoculating it through an unusual avenue; or (c) by inoculating it at a time when the animals are naturally less susceptible, or (d) by a combination of these methods. For example, Texas cattle fever, which is due to a protozoan (Piroplasma bigeminum) conveyed by the bites of infected ticks, may be combated by exposing calves while still milk fed to the bites of a few infected ticks. Another method consists in injecting a small amount of blood from an infected animal directly into the jugular vein. The object is to induce a mild attack of the disease. Occasionally a severe or fatal reaction occurs, but the number of these untoward results is much lower than the mortality among untreated' animals. (3) Active immunity may also be gained by vaccination, i. e., by inoculation with a virus or microparasite or its products, modified and attenuated by passage through a lower animal (Jennerian vaccination) or by various other means, as age, unfavorable cultural conditions, heat, germicides, etc. (Pasteurian vaccination or bacterination) . These subj ects are considered more fully in the chapter on Active Immunization. Active immunity, whether induced accidentally or artificially, may be antitoxic, as after recovery from diphtheria or as the result of active immunization with diphtheria toxin, as by von Behring's method; or antibacterial, as the immunity following typhoid fever or induced by typhoid vaccination, and largely dependent upon the presence of bacteriolysins in the circulating fluids. During the process of active immunization an animal not infrequently fails to react to relatively large doses of toxin, and at the same time the quantity of antibody in the body-fluid may decrease. This phenomenon has been explained as being due to atrophy of the receptors of the body-cells (receptoric atrophy), whereby the toxin fails to exert its deleterious influence because it fails to unite with the body-cells. It is curious, however, that the toxin is innocuous when present in a free state within the body-fluids, even though unbound to the bodycells; this condition is not well understood, and may be dependent upon other factors. A rest may restore the activity of the receptors 'and cells, a fact that is well recognized in the immunization of horses for the preparation of antitoxin. Not infrequently a rabbit fails to produce hemolytic amboceptor if the injections of erythrocytes are too frequent. After a rest, however, the animal may react promptly with much smaller doses. Passive Acquired Immunity. — As the name indicates, this is a form of immunity that depends upon defensive factors not originating in the person or animal protected, but is passively acquired by the injection of serum from one that has acquired an active immunity to the disease in question. This is a sort of secondary immunity, acquired by virtue of having received antibodies actively formed by another animal that has had to resist the infecting agent in order to produce them. Two well-known examples of this type of serums are the diphtheria and tetanus antitoxins. These are produced by injecting horses with successive doses of the respective toxins. The horses are required to combat the effects of the toxins, and acquire an active immunity of increasing grade, due to the production of antitoxins. When the animals are bled, the antitoxinladen serum, separated from the corpuscular elements, may be used for conferring an immunity in a person or another animal simply by injecting the serum, the latter receiving and enjoying an immunity in a passive manner. Passive immunity is specific, that is, the serum of an animal immunized against one microorganism will protect a second animal against that and against no other. This type of immunity is acquired just as soon as the immune serum has become mixed with the blood of the person or animal injected, and there is no negative phase. Hence in severe infections our hopes of specific therapy rest on the production of passive immunity. No matter how sick the recipient may be, under ordinary circumstances the immune serum produces no further disturbance than would be expected from the injection of a normal serum. The recipient's body-cells have no additional burdens, or very slight ones only, to bear and these are more than counterbalanced by the release from combat with toxic substances neutralized by the antibodies in the immune serum. Unfortunately, this field of therapy is limited, although recent discoveries are indicating the reasons for failure, and when these are eliminated, the field of usefulness will be much extended. Passive immunity is of shorter duration than active immunity, and the former is especially indicated in prophylaxis for warding off an acute infection that has a relatively short incubation period. The degree of passive immunity is also seldom equal to that of an active immunity. The antibodies produced by our own cells are more lasting and possess higher protective value. This is an important factor in von Behring's method of immunization in diphtheria, when a small amount of toxin loosely bound to antitoxin is injected in the belief that the toxin becomes dissociated and serves to stimulate our body-cells into producing our own antitoxin. Passive acquired immunity is usually antitoxic, as, for example, that induced by the administration to man of diphtheria antitoxin prepared by the body-cells of the horse. Antibacterial serums may likewise induce a passive immunity, as, for instance, that used in immunization against plague. It is evident, therefore, that the processes whereby infections are overcome and immunity is conferred, and the general reactions that follow the introduction into the body of modified antigens in the practice of immunization, are complex processes, and in none is one antibody produced or solely responsible for the resulting immunity. The properties and action of the known antibodies are considered in subsequent chapters, particular attention being given to methods for determining their presence in the body-fluids, which serve as an aid to the diagnosis of infection as based upon the general law that the antibody is specific for its antigen, and so, when the presence of an antibody is demonstrated, it may be assumed that the antigen is or has been present. Nothing is known concerning the nature of the immunity that is acquired against several infections, such as scarlet fever, measles, smallpox, etc., nor will much be known until the causes that give rise to these conditions have been discovered. Theory of Vaughan. — According to Vaughan, the inability of a bacterial cell to grow in the animal body either because it cannot feed upon the protein of the body or because it is itself destroyed by the ferments elaborated by the body-cells explains all forms of bacterial immunity, either natural or acquired. Thus in antitoxin immunity the toxin is regarded as a ferment that splits up the proteins of the body-cells, setting the protein poison free. The body-cells react with the formation of an antiferment or antitoxin, which neutralizes the toxin and prevents cleavage. The toxin itself is regarded as harmful only in so far as it is the animal body. Acquired immunity, due to recovery from an infection or occurring as a result of vaccination, is regarded as the outcome of the development in the body, during the course of the infective process, of a specific ferment that, on renewed exposure, immediately destroys the infection. The vaccine is the same protein that causes the disease, so modified that it will not produce the disease, but yet so little altered that it will stimulate the body-cells to form a specific ferment that will promptly and quickly destroy the infecting agent on exposure. PHAGOCYTOSIS Historic. — As Lord Lister stated in 1896, "If ever there was a romantic chapter in pathology, it has surely been that of the story of phagocytosis." The author of this "story" is Elie Metchnikoff. His early researches . on phagocytosis in the lowly organized forms of life constituted the starting-point for an entirely new series of researches on the subject of Immunity, and his treatise on the "Comparative Pathology of Inflammation" must ever remain a most entertaining work and a medical classic. Several observers before Metchnikoff had considered that leukocytes might assist in bringing about the destruction of microparasites. Panum (1874) suggested that the bacilli of putrefaction might, by making their way into the blood-corpuscles and being carried off to the lymph-glands, spleen, etc., thus disappear from the body-fluids. Carl Roser (1881) had also observed the ability of certain "contractile cells" to ingest the enemy that enters the animal body. These statements, however, were poorly supported by scientific data, and the subject was >not followed in subsequent research. As the result of zoologic studies, Metchnikoff was led to discover the part played by body-cells in the processes of immunity. He observed that when a food-particle arrives in the vicinity of a simple unicellular organism as an ameba, the latter, by reason of its "irritability, " moves forward and sends out processes of its protoplasm (pseudopodia) that flow around the particle and finally gather it into the interior of the cell. The particle then undergoes a process of intracellular digestion, losing its sharp outline and clear appearance, becoming granular, and disappearing within the protoplasm of its host. Similar studies were made of the processes of nutrition in many unicellular animals, then through actininas, sponges, and similar animals of transparent and simple organization. Metchnikoff was primarily a biologist, and up to this time was mainly interested in the processes of nutrition hi the simple forms of animal fife. At this stage, however, he became greatly impressed by Cohnheim's description of the phenomena of inflammation. The diapedesis of leukocytes through the walls of the blood-vessels in an 12 177 inflammatory reaction impressed him as significant and similar to the movements of the ameba in its process of feeding, and led to comparative studies in inflammation in the lower forms of life, where processes were much simpler to watch and may indicate what occurs in the higher vertebrates. He found that when daphnias are invaded by the spores of a yeast, — the monospora, — they may multiply in the body of the host and bring about its destruction. When, however, a few spores gained access, he found that the daphnia's leukocytes approached them, formed a wall around them, and finally brought about their destruction by a process of digestion. He also observed that if rose prickles were stuck into large bipinnaria larvae of star fish, these were soon enveloped in a mass of ameboid cells. From this he concluded that, in inflammation, the exudation of leukocytes may be regarded as a reaction against any sort of injury, whether mechanical or due to bacterial invasion. Metchnikoff traced this defensive reaction against an invading microorganism from small invertebrates up to man, and showed that instead of bacteria attacking leukocytes and forcing a passage into them, as was then believed, they were indeed pursued and engulfed by the leukocytes. Connecting his various discoveries, he was able to formulate the idea that "the intracellular digestion of unicellular organisms and of many invertebrates had been hereditarily transmitted to the higher animals, and retained in them by the ameboid cells of mesodermic origin. These cells, being capable of ingesting and digesting all kinds* of histologic elements, may apply the same power to the destruction of microorganisms." To a cell, and especially to a leukocyte, possessing this activity and power he applied the name phagocyte, because of its ability to act as a scavenger, gathering up the living and dead material. The theory as originally adduced by Metchnikoff regarded the leukocytes and certain other cells as specific fighting cells, able to engulf and consume living as well as dead bacteria and cellular debris. The outcome of any infection would depend upon the success or failure of the phagocytes to overcome the invaders: if they were successful in ingesting all the bacteria, their victory meant recovery; if, on the other hand, they were destroyed by the invaders, the host was overcome by the infection. A smear of peritoneal exudate from a guinea-pig twenty-four hours after injection with 3 c.c. of a 5 per cent, suspension of pigeon's blood. Note that the corpuscles (nucleated) are being ingested by the large endothelial cells of the peritoneum. A smear of peritoneal exudate from the same guinea-pig forty-eight hours after injection with pigeon's blood. Note the large numbers of corpuscles ingested by the endothelial cells. In most instances the corpuscles have undergone digestion, the nuclei being more resistant. These nuclei are shrunken, and in some instances are broken up. The extracellular red blood-corpuscles are swollen and stain lightly. even soluble substances, such as bacterial toxins. Subsequent discoveries have shown that many other factors are present that considerably modify the workings of so simple a process. Metchnikoff has, therefore, modified his theory from time to time as new discoveries were made, but has always preserved the primary importance of the phagocyte itself. Before stating the revised theory as it stands today, we will describe the kind of cells that may act as phagocytes, and consider the methods and reasons why these cells assume the functions of phagocytes. cytes into two great classes : 1. Microphages — principally the polynuclear neutrophilic leukocytes. (See Fig. 46.) The eosinophilic leukocytes are also included in this group, but are of doubtful importance and weak in phagocytic powers. The small lymphocyte may be included in this class, although it is usually considered with the second group. 0 2. Macrophages, principally the large mononucleaf leukocytes; ameboid cells of the spleen and lymphatic glands; alveolar cells of the lung; endothelial cells of the serous cavities and lymph-spaces; bonecorpuscles and giant-cells of bone-marrow and embryonic connectivetissue cells (Figs. 44 and 45). As shown experimentally by Rous and Jones the phagocytic powers of fibroblasts appear to be very feeble.1 The most important are the leukocytes, especially the polynuelear leukocytes and the large lymphocytes of the blood. All the leukocytes, however, have phagocytic powers, as is well seen in opsonic determinations. Eosinophiles are seldom known to ingest bacteria, but in infections with animal parasites, or after the injection of extracts of animal parasites, both a local and a general increase in eosinophilous forms may be observed. Small lymphocytes are much less active than the large, presumably because they contain less of the mobile cytoplasm, and consist chiefly of the structurally fixed nuclear substance, and while they take up but a small number of bacteria, they may be observed to contain Various other cells, such as red corpuscles and cellular debris. have the power of becoming so are actively phagocytic. Endothelial cells of the lymph-spaces and serous cavities are especially active, not only in the phagocytosis of other cells and cellular debris, but also of various bacteria. In exceptional instances epithelial cells may act as phagocytes. In the presence of an irritant these cells may become detached and act as phagocytes; this is exemplified in the case of chronic passive congestion of the lungs, in which the alveolar cells of the lung ingest the hemosiderin formed and deposited (heart failure cells). Relation of the Cell Types to Infection.— The kind of cells that take part in phagocytosis is determined to some extent by the nature of the irritant. Thus in acute pyogenic infections the polynuclear cell is found to be most active. (See Fig. 46.) It is extremely rare to find these cells containing bacilli in the tissues, although they will take them up readily enough under the artificial conditions of an opsonic determination. (See Fig. 53.) In chronic bacterial infection, such as tuberculosis and syphilis, and in infections with various fungi, the small lymphocyte and macrophages are the types most concerned. Experimental evidence regarding lymphocytic activity is quite contradictory. Undoubtedly many of the cells in the lymphocytic accumulations seen hi such conditions as tuberculosis and syphilis are not really lymphocytes from the blood, but are newly formed cells of the tissues. There is no direct means of inducing experimentally a local accumulation of lymphocytes similar to that induced by most any irritant, resulting in an outpouring of polynuclear cells. Long-continued intoxication of animals may result in increasing the numbers of lymphocytes, but the local introduction of the toxin leads to an accumulation of polynuclear cells, rather than lymphocytes. Reckzeli 1 found that in lymphatic leukemia, in which the lymphocytes greatly exceed the polynuclears, the pus from an acute lesion or the fluid from the vesicles produced by cantharides, contained practically no lymphocytes, but was composed of the usual polynuclear cell forms. Wlassow and Sepp 2 state that lymphocytes are not capable of ameboid movement or phagocytosis at ordinary body temperature; Wolff,3 on the other hand, claims that tetanus and diphtheria toxins produce lymphocytosis in experimental animals, and Zieler4 claims that in the skin of rabbits exposed to the Finsen light active migration of lymphocytes takes place during the reaction. General lymphocytosis may be produced experimentally by the injection of pilocarpin and muscarin, but these bear no relation to the vital process of phagocytosis, as they are apparently ex- The typical macrophages, such as the endothelial cells of serous cavities (Figs. 44 and 45) and the lymph-spaces, are mostly concerned in the phagocytosis of other cells and inorganic material. Erodie2 considers the phagocytosis of leukocytes and red corpuscles by the endothelial cells of the lymph-glands and the spleen as the normal end of these cells. It is a mistake to believe, however, that they do not ingest bacteria, since endothelial cells are extremely active phagocytically for bacteria, and, on the other hand, polynuclear leukocytes may be observed to contain red corpuscles, especially when aided by a suitable opsonin. CHEMOTAXIS An important question in the study of the phenomena of phagocytosis is the manner in which the various leukocytes and other bodycells are attracted to a focus of infection and brought into contact with the microparasites or other foreign substances. It must be assumed that some means of communication must exist between this point and the leukocytes in the circulating blood. Since there is no direct communication by way of the nervous system or other structural route, it would appear that the only mode of communication is through the bodyfluids. Chemical agencies, produced either directly by the bacteria or other foreign substance, or indirectly by their action upon cells at the site of residence in the tissues, are regarded as furnishing the attractive forces that are transmitted through the body-fluids and exert what has been called chemotaxis. The movement of a cell in response to a chemical stimulus is a phenomenon that is displayed by almost all motile and unicellular organisms, whether animal or vegetable, and by the leukocytes and other unfixed cells of the higher animals. As a rule, chemical stimuli serve to attract cells to the site of infection, thus constituting what is known as positive chemotaxis; on the other hand, the stimuli may fail to attract or actually repel the cells, or be so powerful as to paralyze thorn en route, this constituting negative chemotaxis. was first clearly demonstrated by Leber1 in 1879. This writer observed that in keratitis leukocytes invaded the avascular cornea from the distant vessels, not in an irregular manner, but direct to the point of infection, where they accumulated. As dead cultures of staphylococci produced a similar although a less pronounced accumulation of leukocytes, Leber sought the chemotactic substance in their bodiesrand isolated a crystalline, heat-resisting substance — phogosin — which attracted leukocytes in the tissues. Since these fundamental studies were made many other investigations, with various chemical substances of many different origins, have been undertaken upon leukocytes, amebse, ciliata, and plasmodial forms, indicating that chemical substances are mainly concerned in exerting either a positive or a negative chemotactic influence. Experimental evidence tends to show that cells respond to stimuli of various kinds chiefly through the effect of these stimuli upon surface tension: if they decrease the surface tension, the cell goes forward; if they increase the tension, the cell recedes. The behavior of leukocytes in inflammation may be explained on these purely physical grounds. At the site of cell injury or infection chemical substances are produced that tend to lower the surface tension of leukocytes and thus exert a positive chemotactic influence. These chemical stimuli are transmitted by the body-fluids to the nearest capillaries, where they enter through the vessel-wall and come in relation with the slowly moving peripheral leukocytes. The leukocytes will be brought into touch by the chemotactic substances most largely on the side from which the substances diffuse ; accordingly, the surface tension being least nearest the stomata in the capillary wall, this results in the formation of pseudopodia, and motion in this direction, dragging the nucleus along in an apparently passive manner. Those cells, therefore, containing most of the mobile cytoplasm, such as the polynuclear leukocytes, are chiefly affected in these processes; those containing little cytoplasm and a relatively large and dense nucleus, such as the lymphocytes, are affected primarily to a much less extent. Once outside of the vessel-wall, the leukocytes tend to move toward the focus from which the chemotactic substance comes. If the leukocyte meets a substance that greatly lowers its surface tension, it will flow around the object and inclose it, this constituting phagocytosis. The toxins of the ingested bacteria may kill the cell, or so equalize surface tension that movement ceases. Otherwise the leukocytes tend to move 1 Fortschritte der Med., 1888, 6, 460. forward until checked by any one of several influences, as pointed out by Wells, — as (1) Until the chemotactic substance has been used up or removed, or from any of the causes that terminate inflammation; (2) the leukocytes may reach a point where the chemical stimulant is so generally diffused that surface tension is decreased equally in all directions and motility stops; (3) the leukocytes may reach a place where toxins or other chemical substances coagulate their cytoplasm or ferments cause their solution; (4) they may be blocked by a dense wall of leukocytes and other cells while being held fixed by the chemical attraction that diffuses through this wall. These factors would explain the formation of the wall of leukocytes about an area of infection. When, for example, the abscess has ruptured or has been incised, with removal of the chemotactic substances, there may be less chemotactic substances in the center of the inflamed area than there is further out; hence the leukocytes will move away from the center toward the periphery, following the chemotactic substances back into the blood-vessel and lymphstream. This would explain the dispersion of living leukocytes at the close of an inflammatory process. General leukocytosis can be explained equally well by assuming that the chemotactic substances from the area of inflammation, reaching the blood-stream, pass through the bone-marrow, lowering surface tension and attracting leukocytes into the blood-stream as long as it contains more chemotactic substances than the marrow. The exact chemical nature of chemotactic substances is unknown. In bacterial infection the toxins, and especially the protein of dead microorganisms, are regarded as mainly responsible for the occurrence of positive chemotaxis. Chemotaxis and phagocytosis of chemically inert particles, such as coal-dust, stone-dust, and pigments, are more difficult to explain on this physical basis of alteration in surface tension. It is probable that the death of tissue-cells, brought about by these materials, may produce the chemical stimulant responsible for a mild but definite chemotactic influence. Although the movement of amebse and similar fogtier animals cannot be fully explained on this physical basis, the surface tension theory best explains leukocytic movement. Although the ameba may possess some special property that endows it with the power of selecting and engulfing a food particle, it would appear to be entirely unreasonable to assume that a simple, undifferentiated, and naked leukocyte possesses similar powers. The physical theory, therefore, appears to be the most reasonable offered in explanation of the ameboid movements of these simple cells. Negative Chemotaxis. — In nearly all infections we find that leukocytes are attracted in large numbers into the involved area, i. e., nearly all bacteria give off substances that are positively chemotactic. In certain infections, however, we may find the tissues poor in leukocytes, as exemplified in infections due to the presence of virulent streptococci. This negative chemotaxis is more difficult of explanation. Kantlack doubts the existence of really negative chemotactic action upon leukocytes. Verigo1. also considers that as yet no actual negative chemotactic substances have been satisfactorily demonstrated; certainly no marked example o£ negative chemotaxis has been shown since methods involving the study of phagocytosis in vitro have been devised. It is true that virulent bacteria appear to repel the leukocytes, but, as Kantlack has pointed out, these are not necessarily examples of negative chemotaxis, and it is probable that the paucity in numbers of the leukocytes about such an area of inflammation is due to their overstimulation or paralysis and destruction of the powerful ferments that are given off by the bacteria. Thus Metchnikoff has asserted that leukocytes might, after a time, be attracted toward substances that would kill them. Therefore, while leukocytes will migrate freely toward substances that would kill them, they may be destroyed before they reach the inflammatory area, or, having reached there, are promptly destroyed and pass into solution (Fig. 47). While it is doubtful, therefore, whether substances are produced by bacteria that actually repel leukocytes, the point has not been definitely settled. If such substances exist, it would appear that they are closely identified with either the endotoxins or the aggressins, the latter being definite secretory products of bacteria that neutralize opsonins and retard phagocytosis. In many instances it is probable that the same substances that exert a positive chemotaxis are, when concentrated, negatively chemotactic, through overstimulation and paralysis of the leukocytes. With diminution in the numbers or vitality of bacteria and dilution of their chemotactic substances, this inhibiting influence is removed and the leukocytes are attracted to the focus of infection, thus explaining in a way those instances in which positive chemotaxis is observed to follow a primary period of negative chemotaxis. After phagocytosis has been accomplished, the fate of the engulfed objects depends upon their nature. In general they undergo a process 1 Arch. d. med. Exper., 1901, 13, 585. A smear of exudate from the peritoneal cavity of a guinea-pig twenty-four hours after injection with virulent streptococci. The exudate was thin, serous, and tinged with hemoglobin. Note the large numbers of streptococci and relatively few leukocytes. RESULTS OF PHAGOCYTOSIS 185 of digestion. The ameba, for example, is able to kill and digest engulfed material through an intracellular ferment regarded as a form of trypsin, demonstrated by Mouton1 and called amebadiastase. According to Metchnikoff, the digestion of erythrocytes and tissue fragments is accomplished through an enzyme of the macrophages called macrocytase; that of bacteria or other substances engulfed by microphages by a similar enzyme called microcytase. Following the general law that living protoplasm cannot be digested, we are confronted with the very important question as to whether living bacteria are engulfed by phagocytes or whether they are first destroyed by extracellular agencies before they undergo phagocytosis. Endolysins. — It seems positively established at the present time that leukocytes do take up living bacteria, which may either grow inside the leukocyte or be destroyed by intracellular substances called endolysins. On the other hand, leukocytes do not take up extremely virulent bacteria, hence the question arises as to the importance of substances in the body-fluids which neutralize the repelling substances of bacteria and facilitate phagocytosis. This subject, which has considerably modified Metchnikoff's views of phagocytosis, will be considered in a succeeding chapter. It will suffice here to state that leukocytes may engulf living bacteria possessing some virulence, for not infrequently an infection may be spread by bacteria transported into deeper tissues by phagocytes, when they resist the germicidal activity of the endolysins, bring about the death of the phagocyte, and are thus liberated into new tissues. Death of the engulfed bacteria is, therefore, brought about by endolysins 2 that are probably different from the digestive enzymes. These substances are strongly bactericidal, and have a complex structure resembling bacteriolysins. According to Weil,3 they are not specific. They are resistant to 65° C. or even higher, do not readily pass through porcelain filters, are precipitated by saturation with ammonium sulphate, and resemble the enzymes in many respects (Manwaring4). It is probable that the endolysins act not only upon bacteria that have been phagocytosed, but also upon free bacteria when liberated through disintegration of the leukocytes. In this manner the endolysins would closely resemble the normal opsonins or bacteriolysins, and support the contention of Metchnikoff that these important substances contained in the body fluids are derived primarily from the cells which he has classed as phagocytes. According to Schneider,1 lymphocytes and macrophages seem to contain little or no endolysin, and these cells are not so active in the phagocytosis of virulent bacteria as are the microphages. It is possible, however, that in certain instances cells not only fail to kill the microparasites they ingest, but actually protect them from circulating antibodies; apparently the microorganisms of leprosy, tuberculosis, gonorrhea, and leishmaniosis may live more or less habitually within tissue cells, and, as demonstrated by Roux and Jones,2 living phagocytes are able to protect ingested bacteria from the destructive substances in the surrounding fluid, and even from a potent homologous antiserum. Indigestible substances, if chemically inert, may remain in cells, particularly in fixed tissue-cells, for variable periods of time. The leukocytes seem to transfer such particles to other tissues, particularly to the lymph-glands. It is probable that these phagocytes are in turn engulfed by the endothelial cells. Macrophages of the lymph-sinuses or the leukocytes may be destroyed in the glands, and their contents rephagocyted by these cells. In just what manner these insoluble particles reach the gland stroma or perilymphangeal tissues is unknown; it is probable that they are liberated from the lining endothelial cells, and are again seized by the young connective-tissue cells. THE RELATION OF THE BODY-FLUIDS TO PHAGOCYTOSIS Important and far-reaching as were Metchnikoff's researches and conclusions, they were not allowed to pass unchallenged, especially by the adherents of the humoral school, who were able to show the potent influences of the body-fluids in the mechanism of recovery from infections where phagocytosis was little in evidence, or, indeed, where phagocytosis was impossible. It was shown that Metchnikoff's original theory was untenable, and that the leukocyte is almost impotent if removed from the influence of the body-fluids. As demonstrated by Denys, Leclef, Fliigge, Nuttall, Pfeiffer, and others, bacteria may be killed, i. e., may undergo a process of lysis or disintegration, by means of substances in the blood-serum entirely independent of phagocytosis Later researches by Wright, Neufeld, and their coworkers demonstrated most clearly that even in those infections in which phagocytosis was observed and known to be of great importance, the bacteria are first prepared for phagocytosis by substances in the body-fluids, and that without this preliminary preparation of the bacteria phagocytosis was slight and of little consequence. Metchnikoff corroborated most of these discoveries, and modified his theory from time to time to meet the developments and keep them within the limits of the phagocytic theory. For example, when bacteriolysis was shown by Bordet to be due to two separate substances in the body-fluids, which he called substance sensibilisatrice and alexin (later renamed by Ehrlich amboceptor and complement respectively), Metchnikoff claimed that this phenomenon was extracellular digestion, similar to the intracellular digestion that occurs within the phagocyte, and brought about by ferments secreted and liberated from leukocytes or other cells classed as phagocytes. He regards alexin as a cytase secreted by leukocytes, or liberated upon their disintegration; similarly the substance sensibilisatrice is regarded as a free ferment (fixateur), derived principally from leukocytes, and concerned in preparing the bacterial or other cell for the digestive-like action of the cytase. Aside from these free ferments that are capable of producing extracellular lysis, Metchnikoff has long known that other substances that aid phagocytosis itself may be present in the body-fluids; he regards these as of the nature of stimulins, or substances that stimulate leukocytes to become more actively phagocytic. On the other hand, Leishman, Wright and Douglas, Neufeld, and Rimpau, Hektoen, and others have clearly demonstrated that they facilitate phagocytosis, not by stimulating the leukocytes, but rather by lowering the resistance of bacteria or in some way rendering them more vulnerable to phagocytosis (opsonins, bacteriotropins) . Thus the gap between the original cellular theory, which ascribed protection and cure to phagocytosis pure and simple, and the humoral theory (finally summed up by Ehrlich in his side-chain theory), which ascribed the chief and primary roles to substances in the body-fluids, and relegated phagocytes to a position of secondary importance, regarding them only as scavengers that remove dead or disabled microorganisms, has been filled with discoveries correlating both processes. The vitality of the leukocyte is to be regarded as important in the consideration of phagocytosis as a means of defense. While the bodyfluids are acting upon the invaders, the leukocytes themselves are probably undergoing quantitative and qualitative changes. They are increasing in numbers, and, as Rosenow1 has shown, are undergoing more 1 Jour. Infect. Dis., 1906, 3, 683. specific changes. Thus, for instance, the leukocytes from a pneumonia patient were found more vigorous against invasion of the pneumococcus than are those from a normal person, regardless of the influence of serum. When a microparasite is ingested, the process has only begun. Unless suitable endolysins are present and the endotoxin is absorbed or otherwise dealt with, and unless suitable digestive enzymes are secreted and the bacterium is dissolved, the process is useless, or, indeed, if viable bacteria are transported to other parts of the body, it may be dangerous. THE REVISED THEORY AND ROLE OF PHAGOCYTOSIS IN IMMUNITY As previously stated, Metchnikoff has revised his theory from time to time, as these discoveries were made on the influence of substances in the body-fluids, not only upon phagocytosis itself, but also upon the processes of immunity in general. He would regard extracellular cytolysis (bacteriolysis, hemolysis, etc.) as due to the same ferments that bring about the destruction and solution of the ingested bacterium or other cell within the phagocyte, and, further, these extracellular ferments are derived from the cells that are classed as phagocytes. By this method of reasoning he would preserve the importance of the phagocytic theory. In local infections phagocytosis is usually well marked, and no doubt plays an important part in resistance to and recovery from these conditions. Recent investigations by Bull1 have shown that following agglutination of various bacteria in vivo, phagocytosis of the microorganisms frequently follows. In infections due to the various pathogenic micrococci, as staphylococci, pneumococci, and streptococci, phagocytosis appears to be most active and an important means of overcoming the infection. In other infections, as those due to the typhoid bacillus and allied bacilli, it is probable that extracellular substances or antibodies are chiefly operative in affording protection or in overcoming infection, although certain of these, as the agglutinins and opsonins, facilitate phagocytosis. The question, then, of the relative importance of the cellular and humoral theories of immunity resolves itself to a consideration of the origin of the substances in the body-fluids so potent in both processes. If they are derived solely from the cells known to act as phagocytes, then the cellular theory of phagocytosis, in its broader meaning, is the one explanation of the processes of immunity as they are now understood. 1 Jour. Infect. Dis., 1915, 16, 109. This, however, has never been proved, and it is entirely likely that these substances are products of a general, rather than of a more restricted, cellular activity, so that ultimately all immunologic processes are cellular in origin. For this reason we prefer to speak of the phagocytic cell in its relation to immunity when dealing with the relation and activity of microphages and macrophages in a limited sense in the process of phagocytosis. Aside from the question of whether fixed and wandering cells may engulf virulent, microparasites and the influence of substances in the body fluids upon this phase of phagocytosis, we have for consideration the mechanism whereby these cells engulf bacteria and other microparasites, various cells, and inorganic particles. Based upon the direct observations of Metchnikoff and his pupils, the phase of engulfing is accomplished by means of pseudopods and the ameboid movement of the phagocyting cell, whereby the particles become adherent and are finally rolled or passed into the protoplasm of the phagocyte. Recent investigations by Kite and Wherry1 would indicate, however, that in so far as leukocytes are concerned these processes are of minor importance, and that phagocytosis X depends upon the physical conditions of the surface of the phagocytic ' cells, a "stickiness" of the leukocytes, whereby bacteria and other particles become adherent, the engulfing being a purely passive process which depends upon protoplasmic streaming within the cells. They believe that such substances as opsonins act in increasing phagocytosis merely because they increase the ".stickiness" of the cells, and that phagocytosis depends essentially upon the relative stickiness of phagocytes and bacteria; increased phagocytosis in the presence of serum and particularity unheated serum is ascribed to an increased stickiness of the leukocytes. Mechanical contact as well as certain variations in chemical reactions may, therefore, result in the production of those changes in contour and protoplasmic streaming responsible for rolling the particle within the protoplasm of the cell. OPSONINS Historic. — Although there can be no doubt as to the importance of phagocytosis in the mechanism of recovery from infection, yet it was shown by Metchnikoff, as early as 1893, that the body-fluids contained substances that greatly facilitated the phagocytic process, and that leukocytes removed from this influence were practically powerless to engulf and destroy the invading bacterium. In other words, if leukocytes and bacteria are washed free from all traces of serum and then mixed, very few of the leukocytes will be found capable of phagocytizing the bacteria, which means that spontaneous phagocytosis is feeble and hence of slight importance. When, however, fresh serum is added, especially the serum of an animal immunized against the microorganism used in the experiment, phagocytosis is marked, and, indeed, most impressive. Metchnikoff attributed this difference to the influence of a substance in the serum that stimulated (stimulins) the leukocytes to become phagocytes, but later researches have shown that this is probably erroneous, and that the serum facilitates phagocytosis not by exerting a stimulating influence upon the leukocytes, but by preparing the bacteria for the process by making them, as it were, more attractive to the leukocytes. Denys and Leclef, in 1895, were among the first to demonstrate the effect of serum on bacteria in the process of phagocytosis, and the fact that the active substance was not bactericidal in action, but in the nature of a new antibody. Since Metchnikoff had shown that freshly isolated or virulent strains of bacteria were not readily phagocytized, but seemed to resist or repel the leukocytes, it was natural for these observers to suggest that the action of this substance in serum was to neutralize the exotoxins and endotoxins of microorganisms that were regarded as responsible for negative chemotactic influences, and thus, by robbing them of at least two defensive weapons, prepare them for phagocytosis. The subject remained in an uncertain state until 1903, when Wright, and later Wright and Douglas, demonstrated more clearly this action of serum upon bacteria in aiding phagocytosis. Using their own modification of the technic devised by Leishman for measuring the phagocytic PROPERTIES AND NATURE OF OPSONINS 191 power of the blood, these observers first determined the direct dependence of phagocytosis upon some ingredient of the blood-serum, and further proved that this substance acts directly upon bacteria, is bound by the bacteria, and renders them more easily ingested by the leukocytes, i. e., more readily phagocytable. To this substance they gave the name opsonin (from opsono, I prepare food for). At the same time, and independently of Wright, Neufeld and Rimpau conducted similar investigations with immune serum and reached similar conclusions, but called the substance bacteriotropin. Since then both terms have been used, — the former more frequently in English literature, — and this is permissible, providing that it is understood that both are practically the same antibody, and not distinct and separate from each other. As will readily be understood, the bacterial opsonins have been studied most extensively, but opsonins may be present in normal and immune serums for other cells, such as erythrocytes, and these hemopsonins are regarded as separate antibodies, distinct from hemagglutinins and hemolysins. Definition. — Opsonins are substances in normal and immune serums which act upon bacteria and other cells in such a manner as to prepare them for more ready ingestion by the phagocytes. Properties and Nature of Opsonins. — There is considerable difference of opinion regarding the identity and probable structure of opsonins in normal and immune serums. Just as agglutinin for a bacterium, such as Bacillus typhosus, may be found in varying amounts in normal serum, so various opsonins for different bacteria may be found in normal serums. These normal opsonins appear more or less specific for a given bacterium, and in immune serum the specific opsonic substance for the particular bacterium or cell with which immunization has been produced is developed to a high degree. Both owe their full effect to the interaction of two substances. One of these, the common substance, is thermolabile, and destroyed by heating the serum to from 56° to 58° C. for half an hour, whereas the other more specific substance remains unaffected. The latter, in both normal and immune serums, is opsonic by itself, although in the absence of the common thermolabile substance, to a less degree, and is produced anew and specifically by artificial immunization or as the outcome of spontaneous infections. The true nature of opsonins is, therefore, difficult to understand. They have been compared to receptors of the second order, with a haptophore and a toxophore or opsoniferous group. Receptors of this order, however, are active and independent of the presence or absence of complement, whereas the opsonins, although active to some extent in the absence of complement, are far more so if a complement is present. In this respect they resemble amboceptors, or receptors of the third order, opsonins in normal and immune serums representing respectively normal and immune bacterial amboceptors. One objection to this view of their structure is their activity, however slight, when the thermolabile substance is removed by heating, unless the amboceptors are complemented by an endocomplement, as from the bacteria themselves. At the present time, therefore, not a few observers doubt that opsonins exist as true and separate antibodies, and are inclined to regard thermolabile opsonin (largely the opsonin in fresh normal serum) as a complement, and thermostabile opsonin (largely immune opsonin or bacteriotropin) as an amboceptor; it would appear that either alone, but more especially the latter, may facilitate phagocytosis to some extent. This process is, however, much more marked when both substances are acting in unison. While it is true that the bacteriolysin and opsonin content of a serum do not run parallel, our methods for measuring these are not entirely satisfactory; both intracellular and extracellular lysis may be mere differences in degree, depending upon the nature of the bacterium or the concentration of the antibodies, rather than upon separate and distinct antibodies. Source of Opsonins. — Little is definitely known regarding the source of opsonin. Thermostabile opsonin — that which is increased by artificial immunization or during disease, and is largely in the nature of an amboceptor — is probably a product of general cellular activity, and especially of the local cells at the site of infection. Thermolabile opsonin — largely the opsonin occurring in normal serum, and in the nature of a complement — is probably a product of the leukocytes and other cells as well, as it has never been proved that the leukocytes are the sole source of the complements, as Metchnikoff would have us believe. Susceptibility to Opsonification. — As previously stated in the chapter on infection, not all bacteria are equally susceptible to opsonification. As a general rule, recently isolated and virulent microorganisms resist the influence of opsonins until they have undergone culture several times. This resistance may be due to capsule formation, thickening of the ectoplasm, actual self-immunization of the bacterium, or the influence of endotoxins as a protective means against the antibodies of a host, all of these being weakened or lost upon artificial culture-media. ity of the bacterium, in so far, at least, its viability is concerned. Role of Opsonins in Immunity. — Although the exact identity of normal and immune opsonins and their relation to other antibodies is as yet unsettled, the important relation they bear to processes of immunity is generally recognized, especially their ability in aiding resistance to infection by facilitating phagocytosis. They are operative in some infections more than in others, and they are especially active in those conditions in which phagocytosis is recognized as the chief defensive force, as, for example, in pyogenic infections. In these conditions their presence has been taken as a measure (opsonic index of the resistance of the host) and, largely through the researches of Wright and Douglas, a technic for detecting their presence, kind, and quantity in the bodyfluids has been devised, the method and information it yields being of value under certain limitations and in some infections. (See next chapter.) If experiments in vitro may be taken as an example of what occurs in vivo, it must be true that leukocytes are capable of consuming an enormous number of bacteria. Experiments with washed leukocytes —those removed from the influence of serum — show that spontaneous phagocytosis is very slight. Metchnikoff declared these experiments to be untrustworthy for the reason that the various manipulations of washing injures the vitality of the leukocytes. When, however, bacteria are opsonized, that is, are exposed to a serum containing opsonins, and then are thoroughly washed, it is found that the washed leukocytes engulf enormous numbers of bacteria, showing that Metchnikoff's objection to these experiments is unwarranted. Granting, then, that what we call opsonins are substances that facilitate phagocytosis, and that phagocytosis is a process of great importance, especially in certain infections, we must conclude that opsonins play a very important role in immunity; in fact, they constitute the very basis of the phenomenon of phagocytosis in the broader meaning of the term. OPSONIC INDEX WHETHER opsonins are regarded as separate antibodies or as being identical with complements and amboceptors, a measure of their quantity and power may be of aid in formulating a diagnosis, as a guide to active immunization, and as one means of determining the potency of various immune serums used for therapeutic purposes, such as antimeningococcus and antipneumococcus serums. We are mainly indebted to Leishman, Wright and Douglas, Neufeld and Rimpau, and their coworkers for devising a technic that, however imperfect it may be according to the results obtained, has opened a new and important field for the study of immunologic processes. Principle. — This is based upon the method devised by Wright and Douglas, whereby it was sought to determine the amount and kind of opsonin in a patient's serum by comparing the degree of phagocytosis with that occurring when normal serum was used. Definition. — The opsonic index is the ratio of the number of bacteria ingested by a given number of phagocytes in the presence of a patient's serum, to the number ingested by the same number of phagocytes in the presence of normal serum. "An equal volume of the patient's serum, measured in a capillary pipet, is mixed with an equal volume of a suspension of washed leukocytes derived from a normal blood. After this 'phagocytic mixture' has been digested for a suitable period at 37° C., film preparations are made and stained. "A 'phagocytic count' is then undertaken, i. e., the average bacterial ingest of the leukocytes in the phagocytic mixture is determined, and this is compared with the average ingest of the leukocytes in a phagocytic mixture made with normal blood. 1. In diagnosing the presence of bacterial infection, or rather in discovering whether the natural protective powers of the patient's blood have been diminished or increased as the result of the immunizing influence of the infection. 2. In connection with vaccine therapy, to guard against diminishing the opsonin content of the patient's blood; to assure ourselves that our efforts to increase them have been successful, and occasionally to ascertain how long the store of opsonin that has been obtained for the patient remains in the blood. proved : 1. That the bacteria act the same in the body as they do in the testtube. This is known not to be the case, for virulent organisms resist phagocytosis, whereas a non-virulent strain of the same bacterium is easily phagocyted. If, therefore, a laboratory culture of attenuated organisms is used in making the opsonic index, the result can hardly be accepted as a criterion of the power of the patient to overcome the "resistant" or more virulent organism as it occurs in the body. This source of error can be overcome in a manner if the microorganism is isolated and used at once before attenuation occurs. 2. That the leukocytes are a constant factor, and need not be taken into account. Investigation has shown that, as a result of infection, the leukocytes probably undergo qualitative changes and it is hardly fair to accept phagocytosis by normal leukocytes as a criterion of phagocytosis with the patient's own leukocytes, as it occurs in the body during the infection. 3. The method assumes that phagocytosis by the polynuclear leukocyte plays a large part in overcoming the infection. In many cases, however, this is by no means proved. For example, in tuberculosis it is not this form of leukocyte, but the mononuclear form or the lymphocyte, which seems to be more important, and hence it is difficult to understand how the index with the polynuclear leukocyte can aid the question of diagnosis or treatment. 4. The chances for error are considerable. To be of any value, the work requires experience and painstaking care. The results obtained by competent workers with the same blood may show variation, but it must be said that, with strict attention to technic and insistence upon perfect preparations, the worker may usually obtain valuable results. An index taken at one time by one person and later by another, and so on, will not be of as much value as when all are taken by the same worker, who brings practice, skill, and conscientious care to his aid. Precautions in Technic. — 1. Proper controls should be used. When dealing with the tubercle bacillus, the staphylococcus, or any other saprophyte of the external surfaces, or with any pathogenic organism with which we have normally no relations, the serum of a normal individual or the mixed serum of a number of normal persons will furnish the standard of comparison. When, on the other hand, we are dealing with intestinal bacteria or with a saprophyte of the mucous membrane, where, as a rule, any relation with them will be denied, it is difficult to establish a standard of health. Pooled serum is, therefore, necessary, and will furnish a standard for comparison for the purpose of measuring the fluctuations that may occur in the patient's blood. 2. A reasonable degree of phagocytosis should occur in the control serum. This is one of the main drawbacks to the value of the method for certain pathogenic organisms, as the pneumococcus, meningococcus, streptococcus, etc., may resist phagocytosis in normal serum, and thereby show abnormally high indices with immune serum. 3. Efforts at spontaneous phagocytosis should be suppressed in order to measure more accurately the opsonin, as shown by the degree of phagocytosis independent of the inherent activities of the cell itself. Spontaneous phagocytosis can largely be overcome by using 1 per cent, solution of sodium citrate such as is used for the collection of leukocytes. 2. A bacterial emulsion. 3. A suspension of washed human leukocytes in normal salt solution. Collection of Patient's and Control Serum. — 1. The blood is collected in a Wright capsule, as described in Chapter II. content. 5. It is always well to collect the control bloods at the same time the patient's blood is taken, or, if this cannot be done, to place them in an ice-chest as soon after collection as possible. When conducting the test, the control serums are pooled and mixed in a clean watch-glass. The Bacterial Emulsion. — 1. This must be perfectly uniform, free from clumps, and must not undergo agglutination, either spontaneous or with the serum to be tested. With many bacteria, especially the motile ones, such as Bacillus coli and Bacillus typhosus, it is comparatively easy to secure a uniform emulsion. Staphylococci, streptococci, and pneumococci, as a rule, present no difficulties. After growing the culture for from eighteen to twenty-four hours on slants of a suitable medium, add three cubic centimeters of sterile 1 per cent, salt solution, and gently remove the bacterial growth with a platinum loop. The mixture is then pipeted into a separate flask or thick glass test-tube containing glass beads, and shaken by machine or by hand until it is thoroughly emulsified. If necessary, the emulsion may be centrifugalized to remove clumps and is then ready for use. various serums. An emulsion that does not yield a count of at least 250 bacteria within 100 leukocytes is too weak to yield a satisfactory differential count. If the emulsion is too thick, bacteria overlie the leukocytes and introduce error. As a general rule, a suspension containing 500,000,000 bacteria per cubic centimeter is satisfactory. Experience will teach the right density to be used, and frequent trials may be necessary before the right one is secured. 4. The bacteria must be such as will not prove seriously dangerous. In order to obviate any danger attending work with such organisms as the glanders and the tubercle bacillus, first kill the culture by pouring on a 10 to 40 per cent, solution of formalin, mix the culture, shake, transfer to a centrifuge tube, and centrifugalize until the bacteria have been carried to the bottom of the tube. The Washed Leukocytes. — These should consist mainly of the polynuclear leukocytes of a healthy person washed free from any admixture with serum. As usually obtained, the leukocytes are mixed with red corpuscles. It is necessary to collect blood for the leukocytic mixture from a person whose corpuscles are known to be insensitive to agglutination, as otherwise there is an undue lowering of the opsonic effect. The Test. — 1. Prepare capillary pipets of approximately the same caliber. These are made by taking 6-inch lengths of soft clean glass tubing having an external diameter of -f$ inch, heating them in the middle in the tip of the blow-pipe or the Bunsen flame until about ^ inch length of tubing is quite soft. Remove from the flame, and by rapidly separating the two hands draw out the molten glass to a length of from 18 to 20 inches. After cooling, the capillary thread is cut across with a small file, so that from 6 to 8 inches is left attached to each piece of tubing. The ends must be cut square, as ragged and uneven ends are difficult to handle. By means of a wax-pencil make a fine mark at a point about an inch from the free end of each capillary thread. .This indicates the unit volume (Fig. 48). 2. Adjust a well-fitting rubber teat, and draw up the unit volume of blood-cells. A tiny bubble of air is now allowed to enter the thread, and then one volume of the bacterial emulsion is added; another air-bubble is allowed to enter, and finally one volume of serum, so that we have TECHNIC named in their order in the capillary tube from above downward, one volume of blood-cells, an air-bubble, one volume of bacterial emulsion, an air-bubble, and one volume of serum (Fig. 48) . 3. By making gentle pressure on the teat these are then blown out on the surface of a clean glass slide, and perfect mixture effected by making alternate aspiration and expulsion from the capillary tube at least six times (Fig. 49). 4. Carefully reaspirate into the capillary thread, so that the mixture occupies about the middle,. and seal the tip in a low Bunsen flame (Fig. 50) . 7. The phagocytic mixtures are then placed in an incubator at 37° C. for fifteen minutes, except in the case of such bacteria as the Bacillus typhosus and the Bacillus coli, as lysin and agglutinin may be present in the serums of such bacteria when the period is reduced to ten minutes. The special opsoriic incubators built to accommodate individual pipets are particularly serviceable. 8. The tubes are then removed from the incubator, the teats readjusted, the tip of the capillary threads scratched with a file, and evenly broken off. The phagocytic mixture is carefully expelled on a clean glass slide, and a perfect mixture made by alternate aspiration and expulsion. Avoid airbubbles. The whole is then reaspirated, and a small drop of the mixture placed on each of two clean slides that have been roughened with emery paper about % inch from one extremity. With the edge of a spreader slide held at an angle of about 30 degrees, and with moderate pressure, the drop is distributed evenly along about 1J^ inches of the surface of the slide (Fig. 51). The smears are made in duplicate, because one may be more nearly perfect (Fig. 52) than the other, or one may be 3. Dry thoroughly. (b) For Acid-fast Bacilli. — 1. Fix by inverting the films for thirty seconds over a watch-crystal or jar containing formalin, being careful that there are no drops of formalin on the edge of the vessel that might come in contact with the preparation. The films may be fixed also with a saturated solution of mercuric chlorid or with pure methyl alcohol for two minutes. Wash in water and dry. 2. Heat a portion of carbolfuchsin almost to boiling in a test-tube, and pour the hot stain over the films. Allow to remain for at least fifteen minutes. Wash under the tap and dry. The slide is laid on a flat surface; the drop of blood is placed near one end; the spreader is held between the thumb and middle finger of the left hand, at an angle of about 30 degrees, and quickly pushed to the opposite end of the slide. 10. Examination of the stained films with the oil-immersion objective of the microscope will show that polynuclear leukocytes have collected more toward the edges and the end at which the spreading was completed. The individual leukocytes, however, should be separated from one another (Figs. 54 and 55). 11. The edge of the film is examined, and the number of bacteria found in each series of five consecutive phagocytes is noted. If the technic has been satisfactory, no great divergence should be found in the count of each set of five cells. The first slide (on the extreme left) is too thick and honeycombed, due to a greasy slide and large drop of blood; the second is likewise thick and uneven; the third is too thin, and was spread with too small an amount of blood and with the spreader held too upright; the fourth (extreme right) is a satisfactory film; it was spread on a clean slide, is even, smooth, and of the proper thickness. 12. If the films are satisfactory, divide 100 phagocytes into groups of 20. The average ingest of each group should not show a difference of over 10 per cent., otherwise the technic has been faulty and it is necessary to count 250 phagocytes or to repeat the test. If divergence is due to the fact that every now and then one cell has a considerable higher ingest than others and the bacteria are well separated, hyperactivity of the cell is probably the cause. If the bacteria are all clumped together, it must be assumed that there has been a lack of care in preparing the bacterial emulsion or that agglutinin is present in the serum, and the test must be repeated with fresh precautions. QUANTITATIVE ESTIMATION OF BACTERIOTROPINS 203 13. In opsonic work the question as to how a certain element ought to be counted becomes quite evident and important. The proper method of procedure is to determine definitely how they may best be dealt with, and then to follow the rule adopted consistently. If an organism rests on the border of a cell, it will be better to consider it as within the cell and count it. Diplococci or division forms may be counted as one or as two, provided we are consistent in our method. Individual organisms, as distinguished from zoogleic masses, which may be lying on the top of the cell, are counted as if they were within the cell; for we have no means of determining definitely whether or not our suspicions are well grounded. In the case of a beaded or vacuolated bacillus, it is always better to count the whole element as a unit. 14. The phagocytic index is the average number of bacteria or other cells ingested per leukocyte after counting at least from 50 to 100 cells. The total number of bacteria ingested is divided by the total number of phagocytes, the result being the average number of bacteria ingested per leukocyte — i. e., the phagocytic index. Control phagocytic index For example, with patient's serum, 100 phagocytes contain 300 bacteria, the phagocytic index being -f-§-§- = 3. With the control serum, 100 phagocytes contain 500 bacteria, the phagocytic index being fw = 5. The opsonic index is : 16. Simon and Lamar have suggested a modification of Wright's method that has been adopted by many laboratories. It consists in diluting the patient's and control serums up to 1 : 10 or 1 : 100, and preparing mixtures of various dilutions with leukocytes and thinner bacterial emulsions. The percentage of phagocytic cells in the mixtures containing the serum to be tested is compared with the mixtures containing normal serum. It is, therefore, a method of comparative phagocytic indices. QUANTITATIVE ESTIMATION OF BACTERIOTROPINS (NEUFELD) Of the various methods for standardizing an immune serum, particularly antimeningococcus serum, and of obtaining some idea of its serum is in most general use. Neufeld's technic is that generally employed, and is similar to the serum dilution method employed by Simon. It varies from the technic of Wright in several particulars : 2. The actual number of bacteria within the leukocytes are not counted. Various dilutions of serum are used, and the highest dilution in which the bacteria are ingested in great numbers is compared with a normal serum in similar dilution as a control. The highest dilution that still favors phagocytosis is then taken as the bacteriotropic liter of the serum. Serum. — The serum is inactivated by heating it to 55° C. for onehalf hour. In old or carbolized serums this may be omitted, as they are usually free from complement. Tuberculous serums also should not be heated, as their bacteriotropins are very susceptible to heat. preparation of the immune serum should be used as the normal control. An exactly parallel series of dilutions with normal salt solution are made of the immune serum and pooled normal serums in a series of small test-tubes. At least 0.5 c.c. of each dilution should be available for the test; the following dilutions may be used: 1:10, 1:20, 1:50, 1:100, 1:200, 1:400, 1:600, 1:800, 1:1000, 1:2000, etc. After working for some time with normal serums one soon learns the dilution in which the normal bacteriotropins are attenuated. It may not be necessary, therefore, to use the whole series of dilutions with the normal serum. Leukocytes. — Leukocytes may be obtained in several different ways : (1) By injecting a guinea-pig intraperitoneally sixteen to twenty-four hours previously with from 5 to 10 c.c. of sterile aleuronat solution (for method of preparation see p. 361). Pipet the peritoneal exudate into about 20 c.c. of sterile 1 per cent, sodium citrate in normal salt solution in centrifuge tubes. Centrifugalize, and wash the leukocytes again three times with sterile normal salt solution. The sodium citrate solution prevents the coagulation and formation of clumps of leukocytes. may be injected in the same amount. ' 3. If rabbit's leukocytes are preferred, 10 c.c. of aleuronat should be injected into each pleural sac or 20 c.c. intraperitoneally. For mice, an injection of 1 c.c. of aleuronat intraperitoneally is sufficient; human leukocytes may be obtained after the method of Wright. 4. After the final washing, the leukocytes are suspended in sufficient normal salt solution until an opacity equal to a 0.3 per cent, lecithin emulsion in salt solution is attained. Culture. — Cultures should be selected with great care, in order to avoid using one that displays a well-marked tendency to undergo "spontaneous phagocytosis," or, on the other hand, one unduly resistant to phagocytosis. Usually an old strain of meningococci is serviceable; it is generally necessary to try out a number of strains and select the best. Meningococci are grown for twenty-four hours on slants of glucose agar. To each slant add 0.5 c.c. each of bouillon and of normal salt solution, and emulsify the growth. Or the bacteria may be employed in the form of a sixteen to twenty-four hour homogeneous broth culture. Tubercle bacilli may either be triturated in an agate mortar with 1.5 per cent, salt solution added slowly drop by drop, or the tubercle powder of Koch may be employed in an emulsion prepared in the same manner. The resultant emulsion should be freed from coarser clumps by brief centrifugalization, but, as a general rule, it is very difficult to secure a uniform emulsion of tubercle bacilli by any method. upon the variety of microorganism. 6. At the end of the second incubation the leukocytes will have settled to the bottom of the tubes. Carefully remove the supernatant fluid from each tube; mix the sediment well with a loop, and make smears on slides. Label each slide carefully to correspond to its serum dilution. No attempt is made to count the phagocyted bacteria. The relative amount of phagocytosis with the immune serum in various dilutions is compared with the normal controls, and the result is expressed as the bacteriotropic titer. Simon's Method. — This method of counting the number of empty leukocytes with a given dilution of serum is followed; a similar count is made of the normal serum control in the same dilution; thus, if in the control film 25 per cent, of leukocytes were empty, and in the patient's film, 50 per cent., the index would be \|~f = 0.5. A study of the results obtained by this method, and by careful counting after Wright's method, shows that they are fairly comparable, and the method may be used where it is only necessary to determine whether the index is high or low. Precautions. — 1. If phagocytosis is entirely absent, one should not conclude that bacteriotropins are not present. The leukocytes may have been injured, especially if heterologous leukocytes have been present; control examinations with homologous leukocytes (i. e., from the same animal) as the serum should result in phagocytosis. 2. The time during which the tubes were in the incubator may have been too short or too long. Most microorganisms require from onehalf to two hours — meningococci require about one-half hour; pneumococci usually need at least two hours; typhoid and cholera bacilli about fifteen minutes to thirty minutes, as they undergo extracellular or even intracellular lysis quite readily. PRACTICAL VALUE OF THE OPSONIC INDEX 1. In competent hands, the opsonic index of normal persons to most pathogenic organisms has been found to vary from 0.8 to 1.2. As previously mentioned, it is difficult to find a perfectly normal serum for such microorganisms as the Bacillus coli, the staphylococci, Bacillus tuberculosis, etc., as it is unlikely that -any individual can altogether escape active infection at some period of his life. As menstruation approaches, even wider fluctuations occur, the normal index being reestablished by the second or third day. During the first year of life the opsonic index varies to such a degree that it has little or no practical value. the opsonic index has less practical significance than was originally believed. One point is clear, however, that the work of Wright and others has broadened the field of vaccine therapy and placed it upon a firmer foundation. Aside from the 10 per cent, of chances of technical error in making an opsonin measurement, other factors may be present that are entirely beyond control and cannot be measured by the immunisator, and that may seriously affect the value of the opsonic index. for a certain microorganism indicates that this organism is probably the etiologic factor. This possibility is strengthened if the opsonic index for this microorganism is increased by careful manipulation or exercise of the diseased part, when auto-inoculation occurs, with consequent increase of opsonin. 4. In prognosis the opsonic index may have some value in deciding whether an infection has been entirely overcome or is still active. An attempt is made to induce auto-inoculation, as by gentle massage of a knee-joint or a hip; active exercise; deep breathing, etc., and the index is made before, and at frequent intervals after, such attempts. If the index remains unchanged within the normal limits, the assumption is that the infection has been overcome; if, on the other hand, an increase in opsonin occurs, this indicates that an active focus remains. 5. Most value was placed by Wright upon the opsonic index as a guide to the size and frequency of doses of bacterial vaccines in the treatment of disease. A large number of careful determinations showed that an injection of vaccine is followed by a decrease of the opsonins (negative phase), which is of variable degree and duration, according to the amount injected (Fig. 55). This is followed by an increase (positive phase), and coincidentally there is a corresponding improvement in the patient's condition. This subject is discussed more fully in the chapter on Active Immunization. The purpose of proper vaccination, therefore, is so to gage and time the different doses that a pronounced or prolonged negative phase is prevented, as far as possible, and a high positive phase secured and maintained. It is obvious that the technic of opsonic measurement consumes much time, and that the immunisator cannot mark the index at the time a dose of vaccine is given. However, the determination of the opsonic index at proper intervals after the first dose of vaccine may give valuable information as regards the reaction of the patient, and serve as a guide to the size and frequency of subsequent doses. As a routine measure, the opsonic index has fallen into disuse, vaccine therapy being largely guided by the clinical evidences of reaction and the condition of the patient. That it has distinct value, particularly in scientific investigation, is generally admitted, and it is well to remember that in the early years following Wright's investigations the practice of vaccine therapy was limited to those skilled in determining the index, preparing the vaccine, and carefully guiding and guarding its administration. It is to be regretted that the wholesale and indis- criminate manufacture and use of vaccines have brought this valuable field of therapy inevitably into disrepute. This is being realized more and more, and the effort is being made to restore the value of this form of therapy. This effort consists in recognizing the possibilities and limitations of the method, and confining its practice to those who possess, at least, sufficient knowledge of bacteriology to prepare a vaccine and make an opsonic measurement, the best results being secured by cooperation between bacteriologist and clinician. IN this chapter a method for preparing bacterial vaccines will be described, the general discussion of vaccine therapy, with the special technic for preparing cow-pox vaccine, rabies vaccine, tuberculin, and other special vaccines, being taken up in Chapter XXIX. Definition. — Bacterial vaccines are "sterilized and enumerated suspensions of bacteria which furnish, when they dissolve in the body, substances which stimulate the healthy tissues to a production of specific bacteriotropic substances which fasten upon and directly or indirectly contribute to the destruction of the corresponding bacteria" (Wright). TECHNIC FOR PREPARING BACTERIAL VACCINES Bacterial vaccines are made — (1) By procuring the infected material; (2) by preparing pure cultures of the bacteria that are to be attacked; (3) by making suspensions of these in saline solution, adding a preservative, and placing in proper containers. 1. Procuring Infected Material. — Various precautions, according to existing circumstances, should be taken to avoid contamination and to secure material that is truly representative of the focal secretions. For instance, pus should be collected from an abscess cavity or sinus after the surrounding tissues have been cleansed with dilute tincture of iodin, for if we secured a culture of the relatively harmless Staphylococcus epidermidis albus from the skin instead of the Staphylococcus aureus, which may be the cause of infection, our vaccine will have little or no value. Nasal secretion may be secured after cleansing the nasal orifice with soap and warm water, passing a sterile cotton swab through a nasal speculum, and rubbing the surfaces of the lower turbinates and septum lightly. An ear should be cleansed, the excess of secretions removed with sterile swabs, and the culture be made of pus from the infected tissues. Various saprophytes quickly gain admission and grow in the necrotic pus, whereas the infecting bacterium is more likely to be found in the tissues. In the collection of sputum special care is required: the patient should be instructed to brush the teeth with a sterilized brush, rinse the mouth several times with boiled water, and after swallowing several mouthfuls of water, to cough and expectorate into a wide-mouthed sterilized bottle. The sputum may be plated at once, or washed several times in sterile Petri dishes with sterile water and then cultured. Lung Puncture may occasionally be required in infective lung conditions in which sputum is not obtainable or is too badly contaminated. A 5 to 10 c.c. all-glass syringe with a strong needle is sterilized by boiling, and 2 or 3 c.c. of peptone broth introduced. The skin of the chest-wall over the site of infection, as shown by clinical evidence, is sterilized with tincture of iodin, and puncture made into the pulmonary tissues. When the desired depth has been reached, 1 c.c. of the broth is injected gently into the tissues, and after the lapse of a few seconds reaspirated as far as possible into the syringe. During the operation the patient should refrain from respiratory movements, in order to minimize any risk of lacerating the pulmonary tissues (Allen). Urine should always be withdrawn with a sterile catheter after thoroughly cleansing the meatus. This last is especially important, for the infection may be due to a certain strain of Bacillus coli, and unless we are successful in obtaining a culture of this particular strain, the vaccine will have little value. Blood specimens are taken with a sterile syringe from a prominent vein at the elbow after the skin has been cleansed and sterilized with tincture of iodin, and cultured in large amounts on proper culture-media. 2. Preparing Pure Cultures. — This is frequently the most difficult step in the whole technic, for some microorganisms, as, for example, the gonococcus and Bacillus influenzse, grow slowly, require special culturemedia, and their colonies may easily be overlooked. To secure pure cultures, and especially to select one or at most two organisms that may be the chief offenders, considerable bacteriologic knowledge is necessary, and no simple rules or directions can be given in the limited space of this volume. poses of isolation. 2. Cultures of the lesion may be made upon solid media, and isolation carried out after a primary growth has been secured. With proper care, primary cultures may be grown, such as staphylococci from the pus of a freshly incised abscess, or the microorganism of a case of cystitis 212 BACTERIAL VACCINES or pyelitis by securing urine with the aid of a sterilized catheter. If slowly growing organisms, such as Bacillus influenzas, gonococcus, pneumococcus, etc., are to be cultured, "streak" plates are usually satisfactory, and as a routine the best culture-media are, as a rule, those containing serum or blood. best made on solid media. 4. In making a bacterial vaccine of a freely growing microorganism for an individual patient, it will suffice to plant two agar slant tubes; when dealing with bacteria that grow much less luxuriantly, such as streptococci and pneumococci, four to six tubes should be used. 7. Inasmuch as the immunizing power of a vaccine is in most cases a factor of the virulence of the organism, this being especially true of such organisms as the pneumococcus, streptococcus, and influenza bacillus, it is well, whenever possible, to employ the first pure subculture for the preparation of the vaccine. 3. Preparation of the Emulsion. — Carefully observing aseptic precaution throughout, pour a portion of a test-tube of a sterile normal salt solution over the surface of the first culture, shaking the fluid in such a way as to bring the microorganisms into suspension. If the culture is not easily washed from the medium, a sterile platinum loop may be used to remove the growth, care being taken not to cut into the medium and mix the fragments with the bacterial suspension (Fig. 57). The bacterial suspension thus obtained is poured on the surface of the second culture, bringing this into suspension, and repeating the process until the whole series of cultures have been suspended, adding more salt solution if necessary. The final suspension is transferred to a sterile, thick-walled flask containing glass beads, and shaken by hand or in a mechanical shaker until the bacterial masses are broken up (Fig. 58). This may be especially difficult with diphtheria bacilli and streptococci. Unless the emulsion is perfectly homogeneous, the larger particles may be removed by brief centrifugalization or, better, by filtering through a sterile filter. There is evidence to show that bacteria grown on culture-media containing peptone may produce objectionable toxic substances capable of producing anaphylactic phenomena (Reichel and Harkins1). In addition, when, in the preparation of a vaccine, bacteria grown on a serum medium are washed off with normal salt solution, a portion of the serum may be removed and this may be capable of producing disagreeable local and general reactions. For these reasons it is advisable to wash all suspensions by repeated centrifugalization until the supernatant fluid reacts negatively to the biuret or ninhydrin reaction (Willard Stone). 4. Counting of the Bacterial Suspension. — Standardization, best accomplished by counting the bacterial elements con.g tained in a unit volume of the suspension, is necessary in order to adjust our initial dose as experience will "§ dictate and for guidance in making subsequent injections. the dead and the living bacteria, making no distinction, for both furnish the chemical agent that calls forth the elaboration of bacteriotropic substances. Inasmuch as sharp definition and the ^jU & g, quantities of bacterial vaccine the method of Kolle . tj10 (x g or (d) that of Hopkins may be used. § 5 "5 (°0 Method of Wright. — Prepare a simple capil- !§ \| • "f cates aspirating one or two volumes of distilled water ^ ^ after the blood and bacterial suspension, fl? \|3 Now expel from the pipet first only the distilled FIG. 60. — A SATISFACTORY PREPARATION FOR COUNTING A BACTERIAL VACCINE. The microorganisms are well separated and evenly distributed among; the corpuscles; the spread is even and regular, and the corpuscles are not gathered in rouleau formation or irregular clumps. FIG. 61. — AN UNSATISFACTORY PREPARATION FOR COUNTING A BACTERIAL VACCINE. The microorganisms are mostly gathered in irregular masses instead of being separated and evenly distributed; the corpuscles are not separated and evenly distributed, but show a tendency to gather in clumps; both factors render a count difficult, inaccurate, and unsatisfactory then proceed to mix together the whole contents of the pipet, aspirating and reexpelling these a dozen times. Then make two or three microscopic films from the mixture, spreading these out on slides that have been roughened with emery. The films are dried in the air, fixed by immersing them for two minutes in a saturated solution of corrosive sublimate, washed thoroughly, and stained for a minute with carbolfuchsin diluted 1 : 10 or carbolthionin for two to five minutes, and then washed and dried. The films are now given a preliminary examination. If red corpuscles and bacteria are found in approximately the same numbers and the suspension is free from bacterial aggregates, the count may be made (Fig. 60). If either the bacteria or the corpuscles are largely in excess, new mixtures and new films must be made. In case the bacteria are gathered in clumps, the suspension should be shaken again and new films prepared (Fig. 61). When satisfactory films have been obtained, the actual counting may be done. This is carried out with an oil-immersion lens, and in order to secure accuracy, it is necessary to restrict or divide the field by a small square diaphragm made of paper or cardboard, or by inscribing cross lines on a small clean cover-glass and dropping them on the diaphragm of the eye-piece. A field is now chosen at random, and the corpuscles and bacteria are counted, the results being jotted down on a sheet of paper, keeping each enumeration separate and writing the numbers in two columns. Proceed at random from field to field, traversing every part of the slide. Establish a rule for counting corpuscles that transgress or touch the edge of the field. Eliminate from consideration any parts of the films in which the preparation is unsatisfactory as regards the staining, or with respect to the integrity of the red corpuscles. The examination is continued until at least 500 corpuscles have been counted, half of the count being made from the second slide. The number of microorganisms counted is now totaled, and the approximate number per cubic centimeter estimated. Let us assume, for example, that 600 red cells and 1200 bacteria have been counted. Now, a cubic millimeter of blood contains 5,500,000 red corpuscles, and equal volumes of blood and emulsion were taken. A cubic millimeter of the emulsion, therefore, contains ployed for the enumeration of blood-corpuscles, the diluting and staining fluid being made by adding to a 1 per cent, solution of sodium chlorid in distilled water sufficient formalin to make 2 per cent., and alcoholic gentian-violet, 5 per cent. The emulsion is drawn up in a white corpuscle pipet to the mark 0.5, and with diluting fluid to the mark 11. The contents are then mixed thoroughly for several minutes, several drops expelled, a drop placed in the counting chamber and properly covered with a special thin cover-glass. The bacteria are allowed to mately 2 mg., or about 2,500,000,000 organisms. By growing an organism on slants of agar and emulsifying a certain number of loopf uls in a measured quantity of saline solution, an approximate method of standardization is obtained. According to Kolle, ordinary slants of agar will hold about 15 loopf uls of staphylococci, Bacillus typhosus, or Bacillus coli, and about 5 loopfuls of streptococci and gonococci. (d) Method of Hopkins.* — This is based upon concentrating a bacterial suspension by centrif ugalization and the preparation of standard emulsions from the sediment. The emulsion is filtered through a 1 Jour. Amer. Med. Assoc., 1913, xl, 1615. small cotton filter to remove larger clump of bacteria and particles of agar, and is then placed in specially constructed centrifuge tubes (International Centrifuge Company, see Fig. 63), covered with rubber caps, and centrifugal ized for half an hour at a speed of approximately 2,800 revolutions a minute. The salt solution and bacteria above the 0.05 mark are then removed, and 5 c.c. saline solution is measured into the tube, so as to make a 1 per cent, emulsion. If the sediment does not reach the 0.05 mark, its volume is read on the scale, and a corresponding quantity of saline is added to make the emulsion 1 per cent, in strength. The bacteria are forced into suspension, the vaccine transferred to a sterile tube, and the microorganisms killed in the usual manner. Estimations of carefully counted suspensions obtained by centrifugalization in the foregoing manner gave the following results : 5. Sterilizing the Vaccine and Testing its Sterility. — When, after the preliminary examination, the films for counting have been found satisfactory, a pause is made to start the process of sterilization, which may continue while the count is being made. Either heat or a germicide may be used for sterilizing vaccine, preferably the former. The vaccine may be placed in a test-tube, which is then sealed (Fig. 64), and the whole immersed in the water-bath; a simpler method, and one just as good, is to place the flask or tube of the level of the vaccine. Efficient sterilization is dependent upon permitting the process to continue at the minimum temperature for the minimum length of time. With the water-bath at 56° to 60° C. sterilization is nearly always complete in an hour. to a slant of a suitable culture-medium, such as Loffler's blood-serum or blood-agar; this is incubated at least twenty-four hours, or longer if the organism is a slowly growing one. It is then examined, and if found sterile, the preparation of the vaccine may be completed. If not, the vaccine is heated for another hour, or, preferably, a new vaccine is prepared. VACCINE. the treatment is likely to be prolonged, a sufficient number of doses should be provided for. It is a good plan not to dilute all the vaccine, but to preserve the remainder undiluted in case larger doses are subsequently needed. If, for instance, a vaccine of Staphylococcus aureus contains 1,500,000,000 organisms per cubic centimeter and the dose decided upon is 500,000,000 per cubic centimeter, sufficient vaccine for 30 doses is prepared by withdrawing 10 c.c. of vaccine in a sterile container and adding 20 c.c. of sterile salt solution. This mixture is agitated, to insure thorough mixing, and 01 c.c. of a 1:1 00 added to each cubic centimeter of vaccine as a preservative against chance contamination. Thus, in the foregoing example, 3 c.c. of the diluted phenol would be added. The amount of stock vaccine is estimated or measured, 0.5 per cent, phenol is added, and the vaccine stored in a sterile container in the refrigerator, being first properly labeled with the patient's name, the date, and the number of bacteria per cubic centimeter. The vaccine may now be placed in a sterile vaccine bottle, fitted with a sterile rubber cap, and properly labeled (Fig. 64). When it is to be administered, the cap is autogenous vaccines, consists in tubing each dose in separate sterile ampules (Fig. 65), which are then sealed in the flame. When the vaccine is fco be administered, the ampule is well shaken, the neck broken in a towel, and the contents aspirated into a sterile syringe. These ampules may be purchased ready for use or be made in the laboratory, using 6 mm. soft glass tubing (Fig. 6). For pipeting a vaccine into ampules the special automatic pipet shown in the illustration (Fig. 66) is quite convenient. As a rule, vaccines should be preserved in a cool place, such as PREPARATION OF SENSITIZED BACTERIAL VACCINES A highly immune serum is prepared by immunizing a series of rabbits or a goat with the microorganism to be used in preparing the vaccine. The first injections consist of heat-killed emulsions, administered subcutaneously. After the first or second dose the period of heating is gradually reduced, and the dose increased, until finally the injections may be given intravenously and with living microorganisms. From time to time a small amount of serum should be examined for immune bodies : with the typhoid-cholera group, by testing for bacteriolysin and agglutinins; with staphylococci and streptococci, by agglutination, bacteriotropic, and complement-fixation tests; with pneumococci, gonococci, and meningococci, by bacteriolytic, agglutination, and bacteriotropic tests. When a highly immune serum is secured, the animal is bled, the serum isolated, heated to 56° C. for half an hour, and stored in a strictly aseptic manner. To "sensitize" the bacteria, thick, even emulsions of young cultures in normal salt solution are treated with one-half to an equal bulk of inactivated immune serum, and the mixture gently agitated at room temperature for from six to twelve hours. The emulsion is then thoroughly centrifuged, and the residue of bacteria washed three times with sterile salt solution, after the manner in which the red corpuscles are washed. After the final washing the bacteria are resuspended in salt solution, shaken for a time to insure breaking up of agglutinated clumps, counted, heated at 60° C. for an hour, cultured as a test for sterility, and then diluted so that the emulsion will contain slightly larger doses than a corresponding dose of ordinary vaccine prepared for administration. " Sensitization " probably consists in the union of bacteriolytic amboceptor with its antigen, and when injected, serves, with the patient's complement, to hasten solution or lysis of the bacteria (antigen), thereby liberating quickly the chemical substances required for the stimulation of antibodies. Metchnikoff and Besredka are using sensitized living bacteria, and their work is being followed with much interest. In this country strict legal restrictions and regulations exist regarding the sending of living cultures through the mails. If, therefore, the method should fulfil the high claims and expectations made for it, there may be considerable difficulty in bringing it into general use. Syringe. — Vaccines are best administered with the aid of a 1 c.c. all-glass syringe, furnished with a sharp platinum iridium or steel needle. These may be sterilized in boiling water for a minute or longer. After sterilization, the parts should be carefully adjusted and the syringe loaded. According to Wright, time and trouble may be saved by sterilizing in oil at a temperature of 125° to 140° C. If this temperature is not exceeded, the oil can be drawn into the syringe without danger of breaking the glass. The procedure is as follows: Partly fill a tablespoon with any vegetable oil, and into this place a bread-crumb about the size of a large hemp-seed. Then heat over a spirit-lamp until bubbles of steam begin to appear about the bread-crumb. The temperature of the oil is now about that of boiling water. After bubbles have ceased to form about the bread-crumb — meanwhile drawing up the oil once or twice into the syringe — reapply the heat very cautiously until the breadcrumb shows the first sign of turning brown (at about 140° C.). Then, without allowing time for the oil to cool, draw it up two or three times into the syringe, being careful to see that it comes into contact with every part of the interior. If it is desired, so as to improve the appearance, to get rid of all remaining traces of oil from the syringe, this can be easily effected by drawing up into the syringe a very weak (0.25 to 0.50 per cent.) solution of sterilized sodium carbonate. Method of Making the Inoculation. — As the administration of a vaccine is frequently followed by a temporary depression of the resisting powers of the individual and a feeling of lassitude, the injections are, as a rule, best given during the afternoon and evening, the night's rest aiding in overcoming the depression. Since the determination of proper dosage rests mainly on the observation of such clinical signs and symptoms as temperature, pulse, and local reaction at the site of the lesion, the patient should be watched during the following twenty-four to forty-eight hours. The injections should be given at a point where the tissues are loose, where muscular action is not much in evidence, and where pressure by clothing or weight is not made. The most suitable localities are in front of the shoulder, at a site about 1J^ inches below the center of the clavicle; high up in the buttock, or in the side of the abdomen, about two or three inches inside the anterior-superior spine of the ilium. The skin at the point of injection should be touched with tincture of iodin, alcohol. Both convenience and experimental work to test the comparative efficacy of inoculation into different tissues point to the subcutaneous tissues as the most suitable site for inoculation. The best method of procedure is to pick up a fold of skin between the finger and thumb, and then to push the needle well down into the middle of the fold, and slowly inject the fluid. Since it is known that the power of response of the tissues to the stimulus of a vaccine is somewhat limited, it would seem advisable to choose a new site for each successive inoculation. The Effects of Inoculation. — The local effects produced at the site of inoculation vary considerably, being influenced by the nature of the individual, the variety and amount of the inoculum, and the sensitiveness of the patient's tissues to stimulation. In the majority of cases the local reaction is limited to a very slight reddening of the skin around the puncture for an area of about one inch. In some instances, occasionally encountered where a large number of typhoid inoculations have been made, the reaction after the first dose is more severe than after subsequent doses, and is accompanied by considerable edema, hyperemia, and pain. The focal effects about the lesion are exceedingly important in determining the reaction of the patient, and serve as a guide to the adjustment of dosage and intervals. Where, in a case of furuncle, an appropriate dose of staphylococcus vaccine is administered, within a few hours increased hyperemia is seen around the focus, and there is a slight increase in the swelling. When very small doses are given, these focal symptoms may practically be absent, but, as a rule, a slight reaction does no harm, but serves rather to show that the vaccine possesses some degree of potency and may aid in the curative process. The constitutional effects may also vary within wide limits. An adequate, but not excessive, dose may, within a few hours, produce a feeling of lassitude, headache, slight rise in temperature, and acceleration of the pulse-rate. Severe constitutional reactions are generally due to excessive dosage, but may occur in some persons after doses that were previously well borne. Frequency and Dosage of Inoculation. — No definite rules can be laid down, each patient being a law unto himself. The opsonic index has been largely abandoned as a guide to the administration of vaccine, the reaction and condition of the patient now governing the dosage. THE ADMINISTRATION OF A BACTERIAL VACCINE 223 In more acute infections, and in delicate persons, smaller doses are usually indicated. It is well to make the first dose small, and if no reaction occurs within forty-eight hours, a second and a larger dose may be given. If, however, the patient presents other symptoms of a general reaction, the dose given was large enough, and may be repeated, as necessary, at intervals of from five to seven days. It should be carefully borne in mind that an increase in dosage is contraindicated so long as any sign of general or focal reaction is produced and steady progress is maintained. One should always be on guard to detect any signs of fresh infection by some other organism, and if a given vaccine is failing to exert a beneficial effect, additional cultures should be made, instead of continuing to administer dose after dose of the same vaccine. The intervals at which injections are to be made are of some importance. It is certainly better to wait too long than to inoculate prematurely, but the ghost of the "negative phase" is always too prominent in the minds of the inexperienced. The inoculations may be given while improvement is still in progress or convalescence well established, in the endeavor to secure a summation of positive phases of clinical improvement; or one may wait for the first signs of retrogression before administering another dose. The former method is the preferable procedure, but is difficult to accomplish; the latter is less ideal, but is easier to perform and more devoid of risk. The dosage varies according to whether the infection is acute or chronic, the nature of the microorganism, and the age of the patient. No fixed rules can be given. In acute infections the dose should be small and may frequently be repeated; in chronic infections larger doses may be given at longer intervals. If in doubt as to the size of the dose to be given, it is better to give a small dose, and carefully observe the effect on the patient, letting this serve as an index to subsequent doses. Children tolerate relatively large doses of bacterial vaccines, but the dosage should depend on the weight and not on the age of the child. FOR general purposes the antibodies produced during infection may be divided into two groups, the first consisting of those antibodies that are truly antagonistic to the bacterium or its products responsible for their production, and the second those that are not in themselves destructive, but that probably prepare the bacterium for the action of a more powerful antibody of the first group. To the first group belong the antitoxins, which neutralize the toxins of a bacterium without being directly destructive to the microorganism itself; and the bacteriolysins, which are truly destructive, causing the bacterium to break up and finally disappear. To the second group belong the opsonins, which, as we have seen, prepare the bacterium for phagocytosis; and the agglutinins and precipitins, which, while not in themselves destructive, probably in some manner prepare their antigen for the action of bacteriolysins, just as opsonins prepare them for phagocytosis. Historic. — Bacteriolysins were discovered before antitoxins. Their discovery is due to the researches of Nuttall, Fodor, Buchner, and others, who showed that normal serum, and especially the serum of animals artificially immunized against a certain bacterium, was able to exert a destructive action on the microorganism, causing its dissolution and final disappearance. This property of the blood-serum was found to diminish with age, and to disappear completely when the serum was heated to 56° C. Buchner laid greatest stress upon the importance of the thermolabile substance which he called alexin, but later researches have shown that the main factors are the specific bacteriolysins, which, however, are practically powerless to destroy their antigen without the cooperation of alexin (later renamed " complement" by Ehrlich). FORMATION OF ANTITOXINS 225 induced experimentally, while the animals became more and more immune, virulent bacilli may, nevertheless, be present at the site of injection. Here, then, was an example of immunity that could not be explained on the basis of bacteriolysis. Later, in 1890 and 1892, Behring, in collaboration with Kitasato and Wernicke, made further important discoveries, showing that the blood-serum of animals actively immunized against diphtheria and tetanus would protect normal animals against these diseases, and, furthermore, that the blood-serum of the immune animals did not possess bactericidal properties. These observers also demonstrated that such serum could be used therapeutically for the cure of an infection already in progress. Soon after these discoveries Ehrlich showed that specific antitoxins (antiricin, antiabrin, etc.) could also be produced against the poisons of some plants, and Calmette produced a similar antitoxin (antivenin) against snake poison. Other observers since then have increased the list of poisons against which antitoxins can be produced; as, for example, Kempner has produced an antitoxin against the poison of Bacillus botulinus, and Wassermann one against that of Bacillus pyocyaneus. Formation of Antitoxins. — It was formerly believed that there was a direct conversion of toxin into antitoxin, but this certainly is not the case, for the amount of antitoxin produced is altogether out of proportion to the amount of toxin injected. Antitoxins are formed by those cells that anchor the toxins. In order to produce them it is necessary that the toxin enter into direct union with the cells and exert a stimulating influence on them, for where a loose union occurs, as between cells and alkaloids, antibodies are not formed. Having entered into chemical union with the side-arms of cells, a toxin may destroy the entire cell, and if a sufficient number of these are destroyed, the host will show symptoms of infection and may succumb. If, however, the cell itself is not destroyed, but only one or more of the side-arms injured, the damage is repaired by the cell forming new side-arms that have a specific affinity for the toxin responsible for their production. According to Weigert's overproduction theory, a cell once stimulated to produce these side-arms or receptors continues to produce them for some time, even after the stimulus has been removed. In this manner the specific receptors are produced in excess, and since all cannot remain attached to the parent cell, the excess is discharged into the blood-stream. Each of these cast-off receptors is capable of uniting with toxin, thus neutralizing the poisonous principles As Adami has pointed out, it is probable that the toxins exist for some time within the cell, not as part and parcel of the cell, but as a stimulating agent that causes the cell to develop the habit of producing the specific receptors. The mere union of toxin with a receptor, causing it to fall off, and being followed by nature's mode of repair, with the formation of an excess of receptors and no further stimulation, is hardly sufficient to explain the enormous activity of the cells. r, a receptor of the molecule (first order] ; A, overproduction of receptors, which are being cast oft7; A2, a cast-off receptor free in the body-fluids — now an antitoxin; A3, a molecule of antitoxin combination with a toxic molecule T3. A3, a cast-off receptor still within the parent cell; T, a toxin molecule in combination with the receptor of a cell molecule; T2, a toxin molecule free in the body-fluids; T3, a toxin molecule in combination with antitoxin; T4, a molecule of toxoid (toxophore group lost). That antitoxins may be produced locally was illustrated by the experiment of Romer with abrin. This substance has a peculiarly powerful effect upon the conjunctiva. By gradually immunizing the right conjunctiva of a rabbit with increasing doses, it was shown that, after killing the animal and triturating the conjunctiva with a fatal dose of abrin, an injection of the emulsion of the right or immunized conjunctiva was without effect, whereas the emulsion from the left proved fatal. Thus it will clearly be seen that the cells that had absorbed the abrin had developed and contained antiabrin in sufficient amounts to neutralize the poison. While leukocytes, such as Metchnikoff's macrophages, are likewise active in the formation of antitoxins, it is certain that they are not the only cells involved. Metchnikoff claims that antitoxins are merely toxins altered by leukocytic activity, rather than constituents of tissuecells; this explanation is, however, inadequate, and it has been shown experimentally that the quantity of antitoxin produced is so far in excess of the amount of toxin injected as to render this view untenable. Structure of Antitoxins. — According to the side-chain theory, antitoxins are the simplest of antibodies, being composed of a single arm or haptophore group for union with the toxin, and called receptors of the first order. While illustrations of this theoretic structure will convey the impression of mere physical contact or union with toxin, it is to be remembered that experimental data indicate that the union and consequent neutralization of the toxin are chemical .processes. Properties of Antitoxins. — While chemical analyses to determine the nature of antitoxin serums were made as early as 1897, little is known regarding it because it is impossible to secure the antitoxic element free from serum and serum constituents. Belfanti and Carbone found that most of the antitoxin in a serum is precipitated with the globulins by saturation with magnesium sulphate. This work, which has been verified by Atkinson and Pick, shows that the antitoxin is carried down with the globulin precipitates, but does riot necessarily prove that it is itself a globulin. Later Gibson and Banzhaf showed that the portions of the globulin precipitate soluble in saturated sodium chlorid solution carried most of the antitoxin, and with this discovery a practical method of eliminating much of the non-antitoxic portion of the serum was perfected. The relation of antitoxins to proteids has also been studied, digestive ferments being permitted to act on antitoxic serum. It has been shown that antitoxin resists tryptic digestion to a well-marked degree; in this respect it resembles the serum globulin. All the evidence obtained indicates that a closer relation of antitoxins to proteids exists than has been shown for the toxins, although all attempts to separate antitoxins from proteids have thus far failed. 228 ANTITOXINS Antitoxins are fairly resistant bodies, and a properly prepared antitoxic serum, when kept in a cool place and protected from light and air, may be preserved for a year or more with very little deterioration in strength. At times, however, for unknown reasons, antitoxins gradually deteriorate, losing about 2 per cent, in strength a month. Manufacturers have endeavored to calculate this loss in strength, and have placed a label on each package of antitoxin, bearing a date beyond which the serum is not guaranteed to contain the amount of antitoxin present at the time it was put up. The antitoxins, with few exceptions, are far more stable than the toxins, resisting -heating up to 62° C., but gradually deteriorating with higher temperatures. Boiling destroys them completely. They are readily preserved with small amounts of chloroform, phenol, tricresol, etc., although strong solutions of these produce destructive changes. Putrefaction of the serum destroys the antitoxin content. Ehrlich has devised the best method for their preservation, which consists in drying the serum in vacuo and preserving it in the dark, at a low temperature, in the presence of anhydrous phosphoric acid. So preserved, antitoxin retains its strength for prolonged periods and is used in standardizing toxins. Natural Antitoxins. — The appearance of so-called natural antitoxins can be explained on the basis of Ehrlich's theory. Since the antitoxin is composed of receptors that are not new bodies, but simply normal receptors produced in excess, it is reasonable to assume that a few may be thrown off occasionally, constituting the natural antitoxin. Small amounts of natural diphtheria antitoxin may be found in certain individuals and lower animals. Since the diphtheria bacillus is so wide-spread in its distribution, it is possible that minor subinfections may be responsible for antitoxin production, and this is probably always the case when large amounts are found. Information regarding natural antitoxins for other members of the toxin-producing group of microorganisms is less complete, although it is highly probable that natural antitoxins for these exist. The Schick Test for Natural Diphtheria Antitoxin. — Schick1 has worked out a simple and practical skin test which apparent^ has proved satisfactory and trustworthy and of distinct value for detecting natural immunity to diphtheria among persons. This test consists in the intradermic injection of a minute dose of diphtheria toxin. If the person possesses an amount of antitoxin equal to at least one-thirtieth of a unit in each cubic centimeter of blood-serum, 1 Munch, bed. Woch., 1913, Ix, 2608. THE SCHICK TEST FOR NATURAL DIPHTHERIA ANTITOXIN the injected toxin is neutralized and no reaction follows; if, however, the person does not have antitoxin in the body fluids, the injected toxin acts as an irritant to the skin, producing in twenty-four to forty-eight hours a small area of redness and edema. A positive reaction indicates that the person does not possess natural antitoxin in his blood, and therefore that he is susceptible to diphtheria; a negative reaction indicates that natural antitoxin is present and that he is, in all probability, immune to diphtheria. In the presence of exposure to diphtheria, persons reacting positively to .the toxin skin test should receive a prophylactic dose of antitoxin, while those reacting negatively may with safety be spared the injection. TOXIN IN THE SCHICK TEST. The skin has been cleansed with alcohol and pinched up between the thumb and index-finger of the left hand; the needle (No. 26) has been entered into the epidermis and 0.1 c.c. of fluid injected. Note the anemic area indicating that the injection has been intradermic. The same technic is employed in conducting the luetin test.. It will be understood, therefore, that the diphtheria toxin skin reaction is purely an inflammatory reaction due to the fact that the toxin in the skin excites inflammation if not neutralized with diphtheria antitoxin ; it is not an anaphylactic reaction, as the tuberculin and luetin reactions. in the laboratory. A series of guinea-pigs weighing from 250 to 300 grams are injected subcutaneously with increasing doses of a diphtheria toxin to determine the smallest dose that will just kill a pig at the end of four days after injection. This is known as the minimal lethal dose (M.L.D.), and one-fortieth to one-fiftieth this amount is the proper dose to inject into the skin. To facilitate injecting so small an amount of fluid this dose is so diluted with sterile normal salt solution as to be contained in 0.1 c.c.; a preservative, as 0.25 per cent, tricresol or phenol, is added. be without danger. The method of injection is very important. A sterile syringe equipped with a fine needle is required. I use and can recommend the 1 c.c. Record syringe fitted with No. 26 platinum iridium needle, but any accurate syringe so made that 0.1 c.c. can be measured and injected will suffice. The skin of the upper arm is wiped off with a pledget of cotton and alcohol, the skin pinched up between the forefinger and thumb of the left hand, and the needle entered into the epidermis and not under it, so FIG. 70. — THE SCHICK TEST FOR IMMUNITY IN DIPHTHERIA. Dr. J. A. K., a well-marked reaction thirty-six hours after the intracutaneous injection of one-fortieth the minimum lethal dose of a diphtheria toxin diluted to 0.05 c.c. The patient's blood contained no antitoxin. The brownish erythematous area with edematous infiltration of the subcutaneous tissues are characteristic of the reaction. (Reprinted from the Amer. Jour. Dis. Children.) that the injection is intracutaneous and not subcutaneous (Fig. 68) . When 0.1 c.c. is injected the patient should experience a slight stinging sensation and a white anemic and raised spot, resembling a wheal, appears (Fig. 69). If this spot is not seen the injection has probably been subcutaneous and is unsatisfactory. After twenty-four hours a positive reaction is shown by an area of redness and induration. The experienced observer may detect a reaction by simply running the finger over the area of injection, when the induration is easily felt. Persons reacting negatively show nothing more than the point of puncture, and at times a very small area of redness measuring \| inch or less in diameter (Fig. 70). When time permits it is better practice not to read the reaction until forty-eight hours have elapsed, as a few persons will show a false reaction of redness and slight edema at the end of twenty-four hours which disappears after forty-eight hours, whereas the true toxin reaction remains or may slightly enlarge within forty-eight hours, to be followed by gradual disappearance of all signs and brownish discoloration and slight .desquamation of the epithelium, lasting several weeks. In a special study with Dr. Moshage1 of these pseudoreactions I have found that they are to be largely ascribed to a peculiar hypersensitiveness of the skin in certain individuals, as well as to a protein reaction due to the soluble protein constituents of bacilli and beef in the toxin as described by Park, Serota, and Zingher. For this reason it is advisable to use highly potent toxins requiring high dilution, and to reduce trauma as much as possible by injecting not more than 0.1 c.c. as the dose. The safety and practical value of the diphtheria toxin reaction has been established since announced by Schick by numerous investigators in this country, as Park, Zingher and Serota,2 Kolmer and Moshage,3 Weaver and Maher,4 Graef and Ginsberg,5 Moody,6 Bundesen, Moffett7 and Conrad,8 Linenthal and Rubin,9 as well as by several European investigators. In the presence of an outbreak of diphtheria, therefor^, the physician should take cultures and apply the toxin test to all persons exposed. At the end of twenty-four hours he has the evidence offered by both at hand. This delay of twenty-four hours before immunizing with antitoxin is justifiable unless a contact shows clinical signs suggestive of diphtheria. In such an instance we believe that antitoxin should be given as soon as possible. The test has a special field of usefulness in hospitals and institutions for the care of children. All children should be subjected to the toxin test prior to admission, and those immunized who react positively. centage of positive reactions is increased. The percentage of negative reactions is of particular interest as indicating the number of persons who are naturally immune to diphtheria on the evidence of this test, and showing the value of the reaction, especially in institutions for children where a large number may be exposed, and requiring prophylactic injection of antitoxin unless known to be naturally immune to the disease. If it is the custom to reinject with antitoxin a month or six weeks later, it is better practice to apply the toxin test first and administer serum to those only who show a positive reaction. This means a saving of antitoxin and the avoidance of the discomfort attending the injection of serum and disagreeable serum sickness. Specificity of Antitoxins. — Antitoxins well illustrate the law of specificity that exists between antigen and antibody, since they are strictly specific for their toxins. Diphtheria antitoxin will neutralize only diphtheria toxin; tetanus antitoxin, only tetanus toxin, and so on through the list. This specificity is not confined to the particular toxin-producing organism that generates the antitoxin; for example, there are various kinds of diphtheria bacilli, differing as regards morphology and toxicity, although one antitoxin appears to act the same with their various toxins. Nature of the Toxin- Antitoxin Reaction. — While the injection of toxinantitoxin mixtures into the lower animals is the only practical method of testing and standardizing the curative and prophylactic powers of Antitoxin is protective and curative, in that it actually destroys the toxin, in a manner similar to the dissolution of a bacterium caused by a specific bacteriolysin: or it may influence the tissue-cells in some way and render them more resistant to the toxins, a view that was held by Roux, and particularly by Buchner; or the antitoxin may form a direct chemical union with the toxin, similar to the chemical neutralization of an acid by a base — an opinion early held by Behring and elaborated later by Ehrlich. Experimental data support the view of chemical union with the toxin. In the test-tube some time is required for the union of toxin and antitoxin to occur; this union is hastened by heat and retarded by cold; it is more rapid in concentrated than in dilute solutions, and in general takes place in accordance with the law of multiple proportions — all of which tends to show the close similarity of the fcoxin-antitoxin reaction to a chemical process. It is generally conceded that antitoxin does not directly destroy the toxin, for when neutral mixtures of toxin and antitoxin are injected into animals, portions of toxin may become dissociated and unite with tissuecells possessing greater affinity for the toxin, and symptoms of infection may result. It is probable that toxin and antitoxin form a distinct compound, and this action requires time for its consummation. For example, Martin and Cherry, by filtering mixtures of toxin and antitoxin through fine filters that would permit the toxin molecule to pass through but restrain the larger antitoxin molecule, found that, if filtered immediately, all the toxin in the mixtures was extruded, but that, as the interval between mixing and filtration was prolonged, less and less toxin appeared in the filtrate, until finally, two hours after mixing, no toxin whatever passed through the filter. This element of time in support of the chemical nature of the reaction is further strengthened by the experiments of Calmette with snake venom and antivenin, and likewise serves to demonstrate that the antitoxin apparently does not directly destroy the toxin. Although most toxins are thermolabile, Calmette found that snake venom is rendered inert by heating to 68° C., whereas the antivenin remains uninfluenced by a temperature of 80° C. When neutral mixtures of venom-antivenin were heated to 70° C., they were found to become toxic again, presumably on account of the destruction of the antivenin, the venom itself not being destroyed. Similar experiments were carried out by Wassermann with mixtures of pyocyaneus toxin-antitoxin, with similar results. In both instances, however, as developed later, if the mixtures had been allowed to stand longer, these results would not have been secured. Although performed originally to show that an antitoxin does not act by actually destroying its toxin, these experiments simply demonstrate the importance of the element of time in the reaction, without throwing any real light upon the nature of the new toxin-antitoxin compound, if such exists. That toxin is counteracted by antitoxin, independent of the participation of living tissue-cells, has been quite conclusively proved by experiments in vitro. Ehrlich showed that the agglutinating qualities of ricin — a vegetable toxin — may be overcome in the test-tube by adding antiricin, the corresponding antitoxin. Similar results were obtained by Ehrlich with tetanolysin and tetanus antitoxin, and by Stephens and Myers with cobra venom and its antivenin. It is probable that antitoxin has a similar action when injected for therapeutic purposes, as for curing an infection. The longer the interval that has elapsed between the time of infection and the administration of antitoxin, the less satisfactory will be the result, as antitoxin becomes less powerful when toxins have formed a firm union with the body-cells. This is especially true in tetanus, where even very large doses of antitoxin may be incapable of dissociating the toxin molecule from the nerve-cells, the serum, therefore, being of greatest value in prophylaxis. In diphtheria, however, the union between toxin and cells is less firm, and the antitoxin is probably capable of neutralizing the toxin already present in the cells, and especially any toxin that may become dissociated from the cell or is freshly prepared by the diphtheria bacillus at the site of infection. The indication, therefore, in giving antitoxin, is to give a dose large enough to neutralize all free and loosely bound toxin, with an excess to neutralize dissociated toxin and that prepared by the bacillus during the course of the infection. The introduction of the test-tube experiment into the investigation of these reactions permitted more exact observations to be made, and the evidence secured by this means, as well as by carefully graded quantitative animal experiments, would seem to indicate that we should accept, for the present at least, the conception of the chemical nature of the process. PRODUCTION OF ANTITOXINS FOR THERAPEUTIC PURPOSES 235 fections. They are prepared by immunizing horses with carefully graded and increasing doses of the respective toxins until the serum of the animals shows a sufficiently high antitoxin content, after preliminary trials, to warrant more extensive bleeding. Large quantities of blood are then collected aseptically by puncturing the jugular vein. The serum is carefully separated and standardized according to an accepted technic, in order to determine the antitoxin content in units. A small amount of preservative is added, and the serum is finally dispensed in special containers or syringes ready for administration. In some laboratories it is customary to precipitate the globulin fraction of the serum with magnesium or ammonium sulphate, and redissolve the portion containing most of the antitoxin in saturated sodium chlorid solution. The bulk of the serum is thus greatly decreased, and objectionable constituents largely eliminated, to the obvious advantage of the preparation for therapeutic purposes. Antitoxins have also been prepared for other bacterial toxins, as those of the dysentery bacillus (Kruse-Shiga) and Bacillus botulinus, for the vegetable toxins in pollen, and for the animal toxins in snake venoms. There are other serums for the treatment of certain infections, which depend for their effects chiefly upon the presence of bacteriolysins and immune opsonins, and these are described in a subsequent chapter. cepted technic for the production of diphtheria antitoxin: Production of the Diphtheria Toxin. — A strong diphtheria toxin should be obtained by growing a virulent culture in a 2 per cent, nutrient peptone bouillon made from "bob" veal, of an alkalinity that should be about 9 c.c. of normal soda solution per liter above the neutral point to litmus, and prepared from a suitable peptone (Witte). The broth should be poured into large-necked Erlenmeyer flasks in comparatively shallow layers, so as to allow of the free access of air, and maintained at a temperature of about 35° to 36° C. (Fig. 71). In the Hygienic Laboratory of the Public Health and Marine-Hospital Service "Smith's bouillon" is used for preparing the toxin. This is made of fresh lean beef, after the muscle sugar and all other sugars have been removed by fermentation with a good culture of Bacillus coli. The reaction is adjusted until 0.5 per cent, acid to phenolphthalein, that is still distinctly alkaline to litmus, and 1 per cent, peptone, 0.5 per cent. sodium chlorid, and 0.1 per cent, dextrose are added. The reaction is again noted, and adjusted to + 0.5 per cent. The broth is then filtered through filter-paper into flasks and test-tubes and sterilized in the autoclave at a temperature of 120° C. for twenty minutes. After incubating for from seven to ten days the culture is removed, and its purity having been tested by microscopic and cultural methods, it is rendered sterile by the addition of 10 per cent, of a 5 per cent, solution of carbolic acid. After forty-eight hours the dead bacilli have settled on the bottom of the jar, and the clear fluid above is siphoned off, filtered, and stored in full bottles in a cold place until needed (Fig. 72). The bacilli grow on the surface and form a scum. As the culture grows older, the bacilli die and sink to the bottom of the flask. A flask of this shape affords a large surface of culture-medium in contact with oxygen and facilitates toxin production. The culture is contained in the large bottle on the shelf, and drains into the flask, which in turn empties into the earthen "candle." By means of a vacuum the culture is filtered through the " candle" and collects in the large bottle at the base of the stand. soon as the temperature reaction has subsided, a second subcutaneous injection of a slightly larger dose is given, the amount of toxin increasing about 10 to 15 c.c. per dose until, six weeks later, the animal is receiving from 20 to 30 times, and on the sixtieth day about 60 times, the amount originally given. There is absolutely no way of judging which horses will produce the highest grades of antitoxin. Roughly estimated, those horses that are extremely sensitive and those that react feebly are the poorest, but there are exceptions even in these cases. The only reliable method, therefore, is to bleed the horses at the end of six weeks or two months and test their serum. As shown by Park and Zingher, persons yielding negative Schick tests respond to toxin-antitoxin injections with the production of antitoxin more readily than persons who react in a positive manner. Taking advantage of this data, Hitchens and Tingley have injected 0.2 c.c. diphtheria toxin equal to 3 M.L.D. for 250-gram pigs into the conjunctiva of one eye of horses under examination for the purposes of immunization, and found that many yielded negative tests read at the end of forty-eight hours, indicating the presence of natural diphtheria antitoxin in the blood of normal horses; these animals are probably to be preferred in the production of antitoxin, as they are likely to yield highly potent sera. If only high-grade serum is wanted, all horses that give less than 150 units per cubic centimeter should be discarded. The remaining horses should receive steadily increasing doses, the rapidity of the increase and the interval of time between the doses (three days to one week) depending somewhat on the reaction following the injection, an elevation of temperature of more than 3° F. being undesirable. For example, according to Park, a horse that yielded an unusually high grade of serum was started on 12 c.c. of toxin (xuir c.c. fatal dose), together with 10,000 units of antitoxin. Sixty days later a dose of 675 c.c. was given, and the serum contained 1000 units of antitoxin per cubic centimeter. Regular bleedings were made weekly for the next four months, at the end of which time the serum had fallen to 500 units in spite of weekly gradually increasing doses of toxin. At the end of three months the antitoxic serum of all the horses should contain over 300 units, and in about 10 per cent, as much as 800 units in each cubic centimeter. Not more than 1 per cent, give above 1000 units, and, according to Park, so far none has given him as much as 2000 units per cubic centimeter. The very best horses, if pushed to their limit, con- tinue to furnish blood containing the maximum amount of antitoxin for several months, and then, in spite of increasing injections of toxin, begin to furnish blood of gradually decreasing strength. If an interval of three months' freedom from inoculation is allowed once every nine months, the best horses will furnish high-grade serum for from two to four years. Collecting the Serum. — In order to obtain the serum, the neck of the horse should be cleansed thoroughly as for an aseptic operation, and a special tourniquet applied to distend the jugular vein. A small slit is made through the skin over the vein, and a special sharp-pointed cannula is passed upward under the skin for two inches or more and then plunged into the vein. From 6 to 12 liters of blood are collected by a rubber tube into cylindric jars provided with special tops, facilitating filling with blood and subsequent withdrawal of the serum. The cannula, tubing, jars, and everything used in collecting the blood and serum should be carefully sterilized, and the whole operation should be conducted with scrupulous aseptic care in order to avoid contamination. (See Fig. 26.) The jars are set aside (Fig. 73) for three or four days, and the serum is drawn off by means of sterile glass and rubber tubing and stored in large sterile bottles. When the globulins are to be separated, the blood may be added directly to one-tenth of its volume of a 10 per cent, solution of sodium citrate, which prevents clotting of the blood. The serum should be clear and free from blood, and its sterility should be proved by culture tests. An antiseptic, such as 0.4 per cent, tricresol, 0.5 per cent, phenol, or chloroform, may be added, but this is not necessary unless it is desired to keep the serum for some time. The serum is poured into small bottles fitted with rubber stoppers, or placed in special syringes labeled with the number of units contained. The whole- process should be conducted with scrupulous aseptic technic. Diphtheria toxin varies too much to be used as a standard in determining the antitoxin content of a serum; hence a dried antitoxin is prepared by the Hygienic Laboratory and is distributed for this purpose. The serum is evaporated and dried in vacuo by passing dry sterile air heated to 35° C. through it, and when perfectly dry, is preserved in special containers over anhydrous phosphoric acid at a constant temperature of 5° C. Preserved in this manner, the antitoxin is quite stable. Just before use it is dissolved in the required amount of sterile normal salt solution. lins. — The use of concentrated serum has lessened the incidence of serum sickness and facilitates the administration of large doses. Briefly /'the method of Banzhaf is as follows: "The citrated plasma is diluted with half its volume of water and saturated ammonium sulphate solution is added up to 30 per cent, saturated solution. This mixture is heated up to 60° C. and held there for one hour. Then filtered while hot. The precipate contains the native non-antitoxic proteins and a large amount of non-antitoxic proteins newly formed by the above method of heating. This precipitate is discarded. The nitrate is brought up to 50 per cent, saturated ammonium sulphate solution. The resulting precipitate contains only pseudoglobulin and antitoxin and is pressed to remove excess of fluid, followed by dialyzation until free from salts. After dialysis is completed 0.8 per cent, sodium chlorid is added for isotoxicity and 0.3 per cent, tricresol for preservation. It is then filtered through paper pulp and a Berkefeld clay filter, tested for sterility and potency, and filled into sterile syringes or bottles. This method gives a concentration of about six times the original potency" (Park). Standardizing the Serum. — During the earlier investigations it was believed that toxin was quite stable, and that it possessed a definite toxicity with a constant value in neutralizing antitoxin. Upon these suppositions the original Behring-Ehrlich antitoxin unit was based, consisting of 10 times the amount of antitoxin that neutralized 10 fatal doses of toxin. For example, if the minimal lethal dose (M. L. D.) of toxin was 0.001 c.c., and 0.01 c.c. was neutralized by 0.01 c.c. of serum, then 0.1 c.c. of serum equaled' one unit, or 10 units in a cubic centimeter. Later stronger serums were found, and von Behring and Ehrlich modified the unit, which they now call the immunity unit, to be that quantity of antitoxin which will neutralize 100 times the minimal fatal dose for a 250-gram guinea-pig. It was soon discovered that toxins are unstable compounds, and that, almost immediately after their production, they begin to change into toxoids, which are not acutely poisonous, but which retain their power to neutralize antitoxin. In order to standardize a serum it is necessary that the strength of the toxin be known, and since this is so variable, a standard antitoxin is supplied by the Hygienic Laboratory, by which the various antitoxin plants may measure the strength of their toxins. By mixing varying quantities of toxin with one unit of this standard antitoxin and injecting these into 250-gram guinea-pigs, the L+ (limes death) dose is obtained, which is the dose of toxin required to kill a pig in four days with the one = Edema; sometimes late paralysis. = Acute edema and sometimes death. = Always acute death about the fourth day. = Death from second to third day. ' ' = Death about the second day. Here the L+ dose is 0.32 c.c. The dose of toxin that just neutralizes the antitoxin without causing symptoms has been called by Ehrlich the L6 (limes zero) dose, and in this instance it is about 0.24 c.c. This determination, however, has not the same practical value as the Ii dose. The needle is plugged by dipping the tip in carbolized vaselin. The side arm holds sterile salt solution; when the needle has been entered, the injection is given by pressure on the bulb; the side arm is then turned upward, when the contents flow into the main barrel, and injected in this manner insures accuracy in dosage and uniform bulk of inoculum. Having determined the L-j. dose of the toxin, a series of six to eight guinea-pigs are injected with this constant dose of toxin and increasing amounts of the corresponding antitoxin serum; for instance, No. 1 would receive 0.001 c.c. of serum; No. 2, 0.002 c.c.; No. 3, 0.003 c.c.; No. 4, 0.004 c.c.; No. 5, 0.005 c.c.; No. 6, 0.006 c.c., etc. If at the end of the fourth day Nos. 1, 2, 3, and 4 were dead and Nos. 5 and 6 were alive, the serum would contain 200 units of antitoxin in a cubic centimeter. These injections are best given with precision syringes, the one devised by Hitchens being particularly serviceable (Fig. 74). The syringes are sterilized, and the needles are dipped in sterile vaselin to plug them. The mixtures are made in the barrel of the syringe, and sufficient sterile salt solution is placed in the side-arm to bring the total volume of the injection up to 4 c.c., and to wash in all traces of toxin and antitoxin. The mixtures are allowed to stand for at least fifteen minutes (Park) before being injected (Fig. 75). The pigs must be of proper weight — i. e., about 250 to 300 grams; the abdominal wall is shaved, and the injection given directly in the median abdominal line. The animals are placed two in a cage, and carefully observed for four or five days for symptoms of toxemia and edema about the site of injection. principle of this method is based upon the observation that, when very small amounts of diphtheria toxin are injected intracutaneously into the abdominal skin of guineapigs, small areas of edema and necrosis result in about forty-eight hours. When such injections are made with mixtures of toxin and antitoxin, the presence of free toxin is indicated by such tissue changes. It is chiefly used in determining the antitoxin content of human serums after active immunization with the toxin-antitoxin mixtures of von Behring. (See p. 770.) Technid. — I conduct this test in the following manner: The "limes-necrosis" (Ln) dose of a toxin is first determined, which is the amount of toxin which, together with TFJHT of a unit of standard antitoxin, will still produce a minimal amount of necrosis in forty-eight hours after intracutaneous injection into .guinea-pigs. A series of dilutions of the L+ dose of a toxin is made, ranging from 1 : 5 to 1 : 100, and 0.2 c.c. of each mixed with 0.2 c.c. of antitoxin so diluted that each 0.1 c.c. contains PRODUCTION OF TETANUS ANTITOXIN 243 i ATT of a unit. These mixtures are made in small test-tubes, the cotton stoppers paraffined, and the tubes incubated for three hours and placed in the refrigerator for twenty-one hours, after which 0.2 c.c. of each is injected into guinea-pigs (prepared by pulling out the hairs); several injections may be made in each pig. When the Ln dose of the toxin has been determined this amount is mixed in a similar manner with varying amounts of the patient's serum being tested. The amount of serum just neutralizing the toxin contains roVs" °f a unit of antitoxin from which the amount of antitoxin per cubic centimeter of serum may be computed. For example I have found that 0.003 c.c. of serum of a person reacting negatively to the Schick test neutralized this amount of toxin; therefore each cubic centimeter of this person's serum contained 0.33 unit of antitoxin. The method used in the production of tetanus antitoxin is similar to that employed in producing diphtheria-antitoxin, the horses being inoculated with increasing doses of a strong tetanus toxin. Tetanus Toxin. — The toxin is secured by inoculating large flasks or tubes of neutral veal broth containing 1 per cent, of sodium chlorid and peptone with abundant tetanus culture, and growing these anaerobically at 37° C. for two weeks. Anderson and Leake1 prepare 100 liters of broth with 50 kilograms of minced round steak and add 0.5 per cent, sodium chlorid and 1 per cent, peptone; after steaming for an hour the reaction is made neutral to phenolphthalein and the broth filtered through paper into liter Erlenmeyer flasks, followed by steaming without pressure for one and one-half hours. The broth may be stored for a period of two weeks or less. Just before inoculating, a 1 per cent, solution of C. P. glucose (powdered) is added and the medium again heated for one and one-half hours without pressure, cooled to 40° C., and immediately inoculated a few centimeters below the surface with 1 c.c. of a twenty-four-hour broth culture of tetanus bacilli which has been subcultured daily in 1 per cent, glucose broth for one to three weeks. No oil or other means is used to secure anaerobiasis; incubation is allowed to go on undisturbed for fifteen days at 37° C. The cultures are then filtered rapidly through Berkefeld filters, and the toxin preserved in fluid form with the addition of 0.5 per cent, phenol. As previously mentioned, the toxin rapidly deteriorates — especially tetanospasmin — and for purposes of antitoxin standardization it is usually preserved in a dry state after being precipitated with ammonium sulphate. The yellowish, crystalline masses are readily soluble in water or salt solution, and should be used immediately after solution takes place. The strength of the toxin is determined by injecting increasing amounts into white mice or 350-gram guinea-pigs. Immunizing the Animals. — According to Park, the " horses receive 5 c.c. as the initial dose of a toxin, of which 1 c.c. kills 250,000 grams of guinea-pig, and along with this twice the amount of antitoxin required to neutralize it. In five days this dose is doubled, and then every five to seven days larger amounts are given. After the third injection the antitoxin is omitted. The dose is increased at first slowly until appreciable amounts of antitoxin are found to be present, and then as rapidly as the horses can stand it, until they support 700 to 800 c.c. or more at a time. This amount should not be injected in a single place, or severe local and perhaps fatal tetanus may develop." Collecting the Serum. — The horses are bled, and the serum is collected under strict aseptic precautions, in a manner similar to the collection of antidiphtheric serum. The serum should be clear and free from blood, and should be proved sterile by cultural tests. It may be preserved in the liquid state by adding 0.5 per cent, of phenol or 0.4 per cent, of tricresol. Standardizing the Serum. — The official immunity unit of tetanus antitoxin of the United States Government is based largely upon the work of Rosenau and Anderson. These investigators, together with a Committee of the Society of American Bacteriologists, have defined the unit of tetanus antitoxin to be "ten times the least amount of serum necessary to save the life of a 350-gram guinea-pig for ninety-six hours against the official test dose of a standard toxin. This test dose consists of 100 minimal lethal doses of a precipitated and dried toxin, tested out against 350-gram pigs, and preserved in the Hygienic Laboratory, from where it is sent to various antitoxin plants for the purpose of securing a uniform method and unit of standardization. In standardizing tetanus antitoxin, the L+ dose of toxin is employed. A standard toxin and an antitoxin, arbitrary in their first establishment, are preserved in the Hygienic Laboratory, and are kept constant by making frequent tests one against the other. In determining the L+ dose, increasing amounts of toxin are mixed with a constant amount of antitoxin equal to one-tenth of an immunity unit, and injected into 350-gram pigs. This L+ dose of toxin is sent out by the Hygienic Laboratory to those interested, commercially or otherwise, in the manufacture of antitoxin for purposes of standardization. ANTIDYSENTERIC SERUM increasing quantities of antitoxin. The measurements are made with accurate volumetric pipets, and the total volume brought up to 4 c.c. with sterile salt solution in order to equalize concentration and pressure. The mixtures are allowed to stand at room temperature for an hour, and are then injected subcutaneously into 350-gram pigs. This method of titrating the antitoxin is shown in the following example from Rosenau and Anderson: BOTULINUS ANTITOXIN The nature of the botulinus poison has previously been described. Wassermann has recently immunized horses against this toxin, and the antitoxin shows unmistakable value in animal experiments, although it has not been employed frequently enough in this form of poisoning in human beings to prove its value. The Kruse-Shiga type of dysentery bacillus has been shown to produce varying amounts of a soluble toxin; and antiserums, which are partly antitoxic and partly bactericidal in nature, have been prepared, and have apparently yielded good therapeutic results in the hands of several observers. Potent antiserums for the Flexner type of bacillus and for various strains isolated from the feces of cases of infantile ileocolitis have not been produced. Even a virulent strain of the dysentery bacillus does not produce true soluble toxins in a manner comparable to those produced by tetanus and diphtheria. Potent toxins are seldom secured with less than two to three weeks' incubation, and fresh cultures of whole or autolyzed bacilli are likewise quite too toxic, indicating that although a soluble toxin may be produced, considerable endotoxin is also present in the bacilli. Antidysenteric serum has very little prophylactic value, but in individual cases it frequently exerts a curative action, and should be available for use in institutions and armies when dysenteric infection is prevalent. The older investigators, such as Kruse and Shiga, produced antiserums by immunization with whole bacilli. Later Kraus and Doerr prepared antitoxic serums with the toxin alone. At the present time the evidence would seem to indicate that the best serums are prepared by injecting both toxins and bacilli, producing a serum that is essentially antitoxic and bactericidal in action. Culture. — Young and healthy horses are best adapted for immunization. Two methods may be followed: (1) Immunization with toxin or (2) with young cultures of whole bacilli. As previously mentioned, investigations have tended to show that the most potent serums are secured by using mixtures of both toxin and microorganisms. Several strains of dysentery bacilli should be used, in order that a polyvalent serum may be prepared. Cultures should be grown for two weeks at 37° C., in alkaline broth similar to that used for preparing diphtheria toxin; this should be neutralized to phenolphthalein, and 7 c.c. normal soda solution to a liter added. The minimal lethal dose of the mixed unfiltered cultures is determined by giving young rabbits increasing doses intravenously, in order to obtain a guide as to the proper dose for immunization. Fatal doses produce severe diarrhea and paralysis of the extremities, with rapid loss in weight. Rabbits and horses are quite susceptible to the toxin; guinea-pigs and mice are more resistant. dose to remain quite constant. It is good practice to keep the cultures growing during the entire time of immunization. Cultures may, however, be grown for three weeks, filtered through porcelain, and with the addition of 0.5 per cent, phenol, the toxin preserved for long periods of time. The minimal lethal dose of such a toxin is determined in the manner directed above. Immunizing the Animals. — Since horses are quite susceptible, the initial dose of unfiltered and unheated culture should not be larger than the minimal lethal dose for a young rabbit. The dosage is gradually increased, and the injections are given subcutaneously for from four to six months, after which several injections of from 300 to 350 c.c. may be given intravenously at one time. If at any time diarrhea and other symptoms of toxemia are well marked, subsequent doses should be smaller and should be given at longer intervals until a higher immunity is produced. Instead of using bouillon cultures, young agar cultures may be used, the bacilli being grown for seventy-two hours, and one-tenth of an ordinary slant being given as the first dose. The early doses are heated to 60° C. for an hour and injected subcutaneously; the later doses consist of cultures washed from 30 to 40 tubes, and are given intravenously. Flexner and Amoss Method for Rapid Production of Antidysenteric Serum.1 — By this method potent antidysenteric sera can be safely prepared in the horse by the method of three successive intravenous injections of living cultures or toxin with intervening rest periods of seven days; and effective serum for therapeutic purposes may be prepared in about ten weeks. By inoculating alternately living bacilli belonging to the Shiga and Flexner groups a polyvalent serum of high titer may be secured which should be suitable for the serum treatment of acute bacillary dysentery, irrespective of the particular strain or strains of the dysentery bacillus causing the infection. Cultures are grown upon agar-agar slant surfaces in tubes 15x160 mm. in size for twenty-four hours, and the growth in each tube suspended in 2 c.c. of salt solution. Horses are injected intravenously; the first dose is 1 c.c. of the suspension of Flexner bacilli after heating to 60° C. for thirty minutes; on each of the following two days 5 c.c. of heated suspension are usually given, followed by a rest of seven days, when living cultures are injected. The temperature is taken daily and 1 Jour. Exper. Med., 1915, 21, 515. used as an index of the reaction and subsequent doses. With the living bacilli the doses injected on each of three days in succession are four, ten, and thirty loopfuls suspended in salt solution. Flexner and Shiga bacilli are inoculated alternately on three successive days, with intervening rest intervals of seven days, the doses being chosen so as to produce a sharp febrile reaction which subsides in twenty-four hours. At the end of eight to ten weeks' immunization the serum contains immune agglutinins and a well-marked degree of antibacterial and antitoxic value. Collecting and Testing the Serum. — After three or four months a trial bleeding should be made and the serum tested as follows : the minimal lethal dose of a culture is determined and ten times this amount placed in a series of tubes or syringes with increasing doses of serum; the total quantity of injection is made up to 4 c.c. with sterile salt solution. The mixtures are set aside for one hour at 35° C. and injected intravenously in young rabbits. The animals are to be observed for at least five days for diarrhea, paralysis, and loss in weight. For determining the antitoxic value a toxin is prepared by cultivating the bacilli in sugar-free broth containing calcium carbonate for three days; the bacilli are then killed with ether; the ether is removed and the culture filtered through hard paper or a Berkefeld filter and the toxin kept in the refrigerator. No symptoms In this instance 0.004 c.c. of serum was sufficient to protect young rabbits against 10 fatal doses of culture, and demonstrated that it is possible to secure a fairly potent serum against the toxins of the KruseShiga microorganism. According to Todd, if the antiserum is given at least one-half hour after administering the culture, it will protect the rabbit. If given twenty-four hours later, it affords no protection. Similarly, the mixtures of culture and serum must not be injected immediately after mix- If the trial bleeding shows a satisfactory serum, the horse is bled aseptically, as was previously described, and the serum is separated and preserved with 0.5 per cent, phenol in quantities of 10 c.c. in sterile containers. As there is no official immunity unit, the serum is administered in doses of from 5 to 10 c.c. until a therapeutic effect is secured. Both Staphylococcus pyogenes aureus and S. pyogenes albus have been shown to produce certain soluble toxins, such as a leukocidin and a hemolysin, which are partly responsible for the tissue destruction and symptoms that accompany these infections. Severe staphylococcus infection is probably due in part to the paralyzing effect and actual destructive action of the leukocidin upon the leukocytes, preventing, for the time being, the walling-off of the lesion and effectual phagocytosis. Antistaphylococcus serums have been shown to counteract the action of the leukocidin and the hemolysin, and may be useful in the treatment of severe, spreading, or metastatic staphylococcus infections. According to Neisser and Wechsberg, during staphylococcus disease an antihemotoxin is produced against the hemotoxin of the cocci; later Bruck, Michaelis, and Schulze attempted to show that a demonstration of this antistaphylolysin in the serum may be regarded as evidence of a staphylococcus infection. Preparation of Antistaphylococcus Serum. — For immunization purposes several different cultures of the Staphylococcus aureus should be used, in order that the antiserums may be polyvalent. Goats or horses may be employed. Cultures may be grown on neutral agar for fortyeight hours, and an emulsion, equivalent to half an agar slant, heated to 60° C. for one hour and injected subcutaneously in an adult goat. If 10 different strains are used, a four-millimeter loopful from each culture, emulsified in 5 c.c. of sterile salt solution, will be about the proper dose for the first injection. ^ Subsequent doses are given at intervals of a week, and are rapidly increased in size until full, living, unheated cultures are injected intravenously without harm to the animal. The serum may be tested by determining its content of antilysin or of bacteriotropin. Complement-fixation tests are occasionally useful for obtaining an insight into the quantity of bacteriolysin present. the amount of antihemolysin present in a serum, which is dependent on the amount of serum necessary to protect the red blood-cells of rabbits against a solution of the staphylolysin. (a) Staphylolysin. — This is prepared by growing a known hemolysinproducing staphylococcus in slightly alkaline broth for three weeks, filtering through a Berkefeld filter, and preserving the filtrate with 0.5 per cent, phenol in the refrigerator. (6) Rabbit Blood. — Remove 2 or 3 c.c. of blood from the ear of a rabbit and place in 5 c.c. of a 1 per cent, sodium citrate in normal salt solution. Wash the corpuscles three times, and make up in a 1 per cent, suspension (dose 1 c.c.) or up to the original volume of blood (dose, 1 drop). for half an hour. (d) Control Serum. — As every normal serum contains a certain amount of antilysin, it is necessary to use a normal control serum. Normal horse serum, dried in vacuo to prevent deterioration, and freshly dissolved for each test in 10 volumes of sterile distilled water or salt solution, has been advocated by Bruck, Michaelis, and Schulze. (e) The Test. — It is first necessary to titrate the staphylococcus filtrate, to ascertain the amount of lysin present. This is accomplished according to the following scheme: Complete hemolysis In this test 0.1 c.c. is the smallest amount of lysin that can completely hemolyze the given quantity of erythrocytes, and is taken as the unit for the second part of the test. q. s 2 c.c. Complete inhibition of hemolysis Complete inhibition of hemolysis Complete inhibition of hemolysis pletely to neutralize the lysin. A similar test is carried out with normal horse serum. The antilytic dose of this serum is taken as 1, and the patient's serum is compared with this unit. For example, if 0.1 c.c. of normal horse serum was sufficient to neutralize the lysin in this experiment, then the antilysin value of the patient's serum is 2. According to Arndt and others, a high antilysin content of a serum is to be regarded as indicating a staphylococcic infection, even if it is impossible to establish fixed limits for the values. Snake venom contains two toxins, one being largely neurotoxic and producing paralysis of the respiratory centers, and the other being hemotoxic and irritant, and producing local necrosis of tissues, hemolysis, etc. In venom poisoning the neurotoxic effect is most dangerous. Largely as the result of the work of Calmette and Fraser an antivenin has been prepared that is capable of counteracting the neurotoxic action not only of cobra venom, but to a lesser extent of other venoms as well. These serums, however, appear to have no effect or but very little upon the irritant toxins. In the poisonous American snakes, such as the rattler, moccasin, and copperhead, the effects of the irritant toxins are largely in evidence, and satisfactory antiserums for these venoms have not been prepared (McFarland). In preparing antivenins the toxins, since they are thermolabile, must be used unheated; subcutaneous injections are usually followed by extensive sloughing, and although a certain amount of immunity may be induced in the horse by intravenous injection, there is apparently no protection against the local action of the toxins. Preparation of Antivenin. — According to Calmette, horses may be immunized by giving them weekly subcutaneous injections of gradually increasing doses of cobra venom, heated to 70° C., for an hour, which precipitates the irritant toxins without injuring the neurotoxin. The initial dose is usually 0.01 gram, gradually increased until, by the end of four months, 4 grams may be given at a single dose. The serum is then tested by mixing increasing doses with the minimal lethal dose for a young rabbit, and injecting the mixtures intravenously into a series of rabbits. Since the neurotoxin may prove dangerous in any case of snake-bite, antivenin may be given to advantage, although the local pain and necrosis are not relieved by the serum. The pollen of certain plants is markedly toxic for susceptible individuals. In America the pollen of the golden-rod and of rag weed frequently produce a syndrome of distressing symptoms known as " autumnal catarrh." The onset and character of the symptoms of pollen intoxication are strongly suggestive of an anaphylactic reaction. Dunbar has studied pollen toxins quite extensively, and considers them the etiologic factor in the production of hay-fever. Pollen antitoxin has been prepared by immunizing susceptible horses, the toxin being isolated by mixing the ground pollen with 5 per cent, sodium chlorid solution and 0.5 per cent, phenol at 37° C. for ten hours. In the form of a proteid, it is then precipitated by adding eight to ten volumes of 96 per cent, alcohol, dissolving the resultant white precipitate in physiologic salt solution (Citron). THE MEASURE OF ANTITOXINS Antitoxin Unit. — A unit is the definite measure of antitoxin in any serum or solution that will neutralize a certain amount of toxin. As previously stated, the United States Government has established a definite unit for the standardization of diphtheria and tetanus antitoxins, and frequently examines the serums made by various licensed manufacturers. Officers of the Public Health and Marine-Hospital Service purchase from reliable pharmacists several grades of antitoxins made by each manufacturer, which are then sent to the Hygienic Laboratory at Washington, where they are tested for potency, freedom from contamination by bacteria, chemical poisons, especially tetanus toxin, and for excessive The standardization of these serums is useful as a guide to their administration, especially when given for prophylactic purposes, where experience has taught that so many units usually confer protection; it also serves for purposes of record. In the treatment of diphtheria and tetanus, however, the serums are usually given until a therapeutic effect is noted, regardless of the number of units administered. If it were possible to determine quickly and accurately the amount of toxin in a given patient, then neutralization could be accomplished along the same lines that make this possible in the test-tube. The indications are to administer at once sufficient antitoxin to neutralize all the toxin, giving subsequent doses large enough to overcome the toxin as it is produced until the focus of infection is removed. Antitoxin should be kept in a cold place and protected from air and light. When this is done, they usually do not deteriorate more than 30 per cent, of their original strength, and often much less, within a year. All manufacturers place a larger number of units in the container than the label calls for, in this way allowing for the gradual loss in strength up to the date specified on the label. According to Park, the antitoxin in old serum is just as effective as that in fresh serum, except that there is less of it. PRACTICAL APPLICATION The employment of antitoxic serums both in prophylaxis and in the treatment of infection, is considered in greater detail in the chapter on Passive Immunization and Serum Therapy. FERMENTS AND ANTIFERMENTS Bacterial Ferments. — In addition to the toxins, most bacteria possess certain ferments or enzymes that may play an important role in the processes of disease. After toxins have destroyed body-cells, proteolytic ferments, partly derived from the bacteria, aid in their digestion and produce a homogeneous puriform substance. A similar condition may be demonstrated in vitro in cultures of Bacillus subtilis on coagulated blood-serum media when the entire tube of medium is quickly liquefied into a creamy fluid resembling pus. The action of the proteolytic ferment is also demonstrated in the liquefaction of gelatin. Pyocyanase is a ferment that is capable of digesting other bacteria, such as Bacillus anthrax, Bacillus diphtherise, staphylococci, and streptococci. It has been asserted that the injection of this ferment is followed by an increased resistance to infection. Some years ago pyocyanase was manufactured extensively and its use advocated in the treatment of local infections, the purpose being to effect digestion of the disease-producing microorganisms. These claims have not, however, been substantiated, and the treatment has been generally abandoned. In addition to this proteolytic ferment, bacteria may possess diastatic ferments capable of converting starches into sugars; inverting ferments, which may change polysaccharids into monosaccharids; rennin-like ferments capable of coagulating milk, etc. Not all bacteria possess all these ferments, but a study of them may aid greatly in the identification of the various bacterial species. Similarity Between Toxins and Ferments. — Aside from the definite ferments that are in the nature of secretory products of the bacteria, there are many points of resemblance between the toxins, both exotoxins and endotoxins, and the ferments or enzymes. It would seem that the whole subject of infection and immunity is becoming more and more closely identified with physiologic chemistry, especially with the lipoids and lipolytic ferments. This subject constitutes today a most important field for investigation. SIMILARITY BETWEEN TOXINS AND FERMENTS 255 With diphtheria bacilli Kolmer and Moshage1 have shown that the true toxin and carbohydrate-splitting ferments are independent, although the ferment-like carbohydrate-splitting products are most likely to be produced by toxin-producing bacilli. amount present. 3. Both substances represent a method or means by which the organism attempts to modify its environment and render the surroundings suitable for its nutrition and growth. 4. Both show a strong affinity for their substratum, and first manifest their activity by combining with it. For example, fibrin placed in gastric juice at 0° C. and then repeatedly washed in cold water to remove all traces of pepsin will undergo digestion when raised to body temperature. Similarly, if red corpuscles are placed in fresh tetanus toxin at 0° C. for an hour, washed repeatedly with cold normal saline solution, and then raised to 37° C., hemolysis will take place, indicating the primary union of the bacterial hemolysin or tetanolysin with the corpuscles. In a similar manner toxins probably unite chemically with tissue-cells, as the toxin quickly disappears from the blood following its injection and but a small fraction can be recovered from the excretions. Furthermore, the injection of an emulsion of these cells into other animals may be followed by specific symptoms of intoxication. 5. The activities of both toxins and ferments seem to depend largely upon the temperature to which they are exposed. For instance, in the example previously cited, tetanus toxin is harmless for the frog until the temperature of the animal is raised to about 37° C. 7. The one great difference, however, between toxins and enzymes is the greater activity of the latter, even very minute amounts of an enzyme having the power to split up or decompose large quantities of complex organic compounds. An enzyme attaches itself to a substance and absorbs water; the molecule breaks down, the enzyme is liberated, and then attacks another molecule, this process being repeated until Harge amounts of fermentable substances have been attacked. When, however, a toxin has united with a substance it loses its identity, and in this manner it follows the law of multiple proportions. This has been discussed as it relates to the soluble toxins of diphtheria and tetanus, and is likewise easily demonstrable in the action of tetanolysin upon erythrocytes of the rabbit. It is true that a toxin may become dissoci1 Jour. Infect. Dis., 1916, 19, 28. ated and attack another molecule, but this action is different from that of an enzyme, because the molecule first attacked is not injured. However, as Adami points out, the toxins may be equally active in the body until arrested by antitoxins, although experiments in vitro clearly demonstrate the greater activity of the ferments. 8. Even in serum hemolysis it would appear that a lipolytic ferment is vitally concerned. According to Jobling and Bull,1 the end-piece of split complement contains a lipolytic ferment. These observers believe that a parallelism exists between lipase content and complement activity of the serums of various animals. As will be pointed out further on, the complements possess many properties resembling those of the ferments, and many factors are being established to show the important relation that lipoids and Upases bear to immunologic processes. ANTIFERMENTS According to some investigators, antif erments are to be found in large amounts in all normal serums, and are probably vitally concerned in the processes of life in preventing autodigestion. That they may be increased in number artificially by immunization up to a certain limit has been disputed; it is certain that they never attain the extreme amounts possible with the injection of toxins. This may be due to the formation of anti-anti-enzymes, produced by a regulating mechanism that prevents anti-enzymes from accumulating beyond a certain point and interfering with nutrition. It is possible that the body mechanism exerts a strict regulating effect between the formation of enzymes and anti-enzymes. Furthermore, when free receptors, such as normal anti-enzymes, are present hi the body-fluids, the body-cells are not stimulated to produce these anti-enzymes in excess, nor does the presence of the free receptors stimulate the cells to produce anti-bodies against their normal side-chains. Many investigators claim to have produced antiferments experimentally. Morgenroth 2 believed that he obtained a specific antirennin by inoculating goats with rennin. Sachs 3 and Achaline 4 assert that they have produced specific antipepsin or antitrypsin by inoculating animals with these ferments. Antisteapsin and antilactase have been prepared by Schutze,5 antityrosinase by Gessard,6 and antiurease by Moll.7 1 Jour. Exper. Med., 1913, xvii, 61. 2 Centralbl. f. Bakteriol., 1899, xxvi, 349. 3 Fortschr. d. Med., 1902, 20, 425. 4 Ann. de 1'Inst. Pasteur, 1901, xv, 737. 6 Zeitschr. f. Hygiene, 1904, 48, 457; Deutsch. med. Wochen., 1904, 30, 308. 6 Ann. de 1'Inst. Pasteur, 1901, 15. 7 Hofmeister's Beitr., 1902, 2. firmed. The inhibitory substances on trypsin in blood-serum, for instance, have been ascribed by Jobling and Petersen1 to the presence of compounds of the unsaturated fatty acids. Antibodies and Antiferments. — Elsewhere has been discussed more fully the parallelism that exists between bacterial antibodies and antiferments. One is impressed with the similarity of the processes concerned in the breaking down of food-stuffs into simple substances for assimilation by ferments and the destruction of bacteria and their products by antibodies. The processes that occur when a cell digests an ingested microbe by a cytase must be similar to that which occurs in the digestion of any other foreign matter, and it is but a short step to conceive that bacteriolysis in the body fluids is similar to the processes concerned in the digestion of protein by the body cells. The close similarity that exists between the toxins and the ferments, the antitoxins and the antiferments, complements and kinases, and the quantitative relations existing between a toxin and its antitoxin, between a ferment and its antiferment — all these indicate, as Adami has pointed out, the close parallelism that exists between toxins and cytolysins and ferments of different orders and grades. They would seem to indicate, moreover, that we are probably dealing with one common group of enzymic substances that act not by physical contact, but by chemical combination. Antiferments in Disease. — In this connection a subject of considerable interest is the probable nature of the syphilitic antibody so vitally concerned in the Wassermann reaction. Although the true nature of this reaction is unknown, there can be no doubt as to the intimate relation of lipoidal substances to the processes concerned. It is probable that the Treponema pallidum produces a true antibody, and a second body, in the nature of a cellular reactionary substance, which has a marked affinity for lipoids. When the two substances are mixed and complement added, the latter is adsorbed or inactivated to a greater or less degree, so that upon the subsequent addition of washed erythrocytes and its corresponding hemolytic amboceptor hemolysis either does not occur at all or is more or less incomplete. A similar "reagin" is present in the blood-serum of persons suffering with yaws and tuberculous leprosy, and although its exact nature is unknown, its peculiar behavior toward the lipoids suggests strongly that it is a product of the toxic action of the causal parasite upon the lipoids of the body-cells and is in the nature of an antilipoid. (See Wassermann reaction.) Jochmann and Muller have demonstrated the presence of an antiferment in the serum used against leukocytic ferments in diseases associated with great destruction of the leukocytes. Following these observers, Marcus Brieger and Trebing x found that 90 per cent, of the patients suffering from carcinoma or sarcoma examined by them showed an increase of antitrypsin in the blood. Von Bergmann and Meyer2 confirmed this observation, although they found that a similar increase also occurred in 24 per cent, of non-cancerous patients. More recent work would indicate that the antitrypsin may be present in acute infections, such as pneumonia, typhoid fever, etc., in chronic infections, such as tuberculosis and syphilis, in exophthalmic goiter, and in severe anemias. As previously mentioned, Schwartz,3 Suginoto,4 and Jobling and Petersen 5 believe that the antitryptic influence of blood-serum is due to the lipoids, and especially to the compounds of the unsaturated fatty acids. The tryptic ferment liberated by disintegrating leukocytes and connective-tissue cells is largely responsible for the liquefaction of these cells and the formation of pus, as in abscess formation and autodigestion of infected surface wounds. On the other hand, an antitrypsin-like substance tends to limit the activities of the ferment and protect the surrounding tissues from progressive destruction. A deficiency of this substance may account for the rapid breaking-down of infected glands and of a walled-off tuberculous lesion, the development of carbuncles, etc. A study of the antitryptic power of the blood may, therefore, prove of value in suppurative processes and in malignant disease, and considerably influence a prognosis. Ferments in Pregnancy and Disease. — It is largely to the researches of Abderhalden and his associates that we owe our knowledge of the fact that when food-stuffs are introduced into the body parenterally, i. e., by subcutaneous or intravenous injection, ferments are produced that, by process of cleavage and reduction, deprive them of their individuality. For example, as shown by Weinland,6 normal dog serum cannot reduce cane-sugar, whereas the serum of a dog immunized by several injections of this sugar is able to reduce it in vitro by means of a specific ferment of the nature of invertin. Similarly, normal serum is unable to cleave edestin (vegetable albumin), whereas the serum of an immunized dog will split this protein into simpler substances. After he had proved experimentally that the animal organism is able to mobilize ferments against foreign substances, Abderhalden next took up the question whether ferments are produced when substances native to the body but foreign to the blood are introduced into the circulation. Having learned from the researches of Veit, Schmorl, Weichard, and others that during pregnancy syncytial cells frequently enter the maternal circulation, Abderhalden used the serums of pregnant animals, and found that they contained a ferment-like substance capable of splitting placental peptone into amino-acids and coagulated placenta into peptones, polypeptids, and amino-acids. It was apparently thus established that the body cells are harmonically attuned to one another, and if new or modified cells or their products are brought into relation with other cells, they are received as foreign invaders, and their entrance is followed by the production of what Abderhalden has called "protective ferments" ("Abwehrfermente") capable of bringing about their cleavage into simpler products. In this manner the presence in the circulation of some of the body cells may give rise to the production of these ferments if the cells in question are really foreign to the blood-plasma and other cells. Abderhalden has also stated that although he was led to make these investigations on the supposition that syncytial elements were present in the blood of pregnant women, it is not necessary that they be constantly in the blood, for every case of pregnancy has a complicated protein metabolism and there is a general exchange of substances between the placenta and the maternal blood that permits the entrance into the latter of protein products that have not been broken down completely into amino-acids, and that cause the organism to produce defensive proteolytic ferments. In cancer, where the production of new cells is so marked, some of these cells or their products may easily be swept into the general circulation, where they act as foreign invaders and cause the formation of protective proteolytic ferments. It is a noteworthy fact, moreover, that the serum of carcinoma cases reacts best with carcinoma cells and that of sarcoma with sarcoma cells. Similar ferments have been described in other conditions. Fauser has demonstrated that the blood-serum of dementia prsecox patients contains ferments that act on the reproduction glands, so that the serum of males reacts with testicular extracts and that of females with ovarian extracts. These serums were, however, also found to react with thyroid tissue and brain cortex. In general paresis reactions were obtained with brain cortex and liver, also at times with thyroid gland, reproductive glands, and more rarely with kidney. Abderhalden has found ferments for the tubercle bacilli in the blood-serum of tuberculous persons, and they have also been found in the blood-serum of syphilitics for the Treponema pallidum, either in pure culture or in organs containing large numbers of the parasites; Smith1 has found a remarkable specificity of the ferments produced in rabbits following immunization with typhoid and paratyphoid bacilli and cocci. Although these protective ferments are in general similar to the cytolysins or antibodies produced during bacterial and protozoan infections capable of lysing or digesting their antigens, their exact nature and relation to the cytolysins have not been determined. From the evidence at hand it would appear that the ferment-like cytolysin is specifically directed against the toxic portion of a bacterial cell, and the proteolytic ferment against the bacterial cell itself. Recent work by Pearce and Williams2 would seem to indicate that the cytolysins and protective ferments are separate substances, but considerable additional experimental investigation is required to clear up the point. Mechanism of the Abderhalden Reaction. — Aside from the probable clinical value of the methods devised by Abderhalden in the serum diagnosis of pregnancy and various pathologic conditions, as malignancy, tuberculosis, lesions of the nervous system and ductless glands, most interest concerns the question of the specificity of the ferments or antibodies concerned and the mechanism of their action. While Abderhalden and many of his pupils have claimed a high degree of specificity for the "protective ferments" and his pregnancy reaction, claiming from the beginning that errors of technic were largely responsible for the failure of others to obtain satisfactory results, the dialysis test as now conducted is not especially difficult, and sufficient work has been done by other investigators who have followed Abderhalden's technic with great care and exactness to give warrant to the claim that other factors aside from those purely technical may be responsible for the divergent and non-specific results obtained. As previously stated, Abderhalden bases his theory concerning the "protective ferments" upon the specific digestion of a substrat by specific ferments, claiming that these ferments are separate and dis- or cytolysins of Ehrlich. That the substrat in the pregnancy test is a boiled tissue would seem to impair the specificity of the reaction, and, indeed, certain physical factors, as the mechanical state of division of the substrat and its facility for acting as an absorbent in a purely mechanical capacity, likewise appear to be factors in the reaction on the basis of numerous investigations showing that loose areolar placental tissue is frequently digested by normal sera and various pathologic sera irrespective of pregnancy, whereas digestion of a firm and compact tissue as that of malignant tumors is much less constant. In this connection the work of de Waele1 has a bearing, inasmuch as he found that any agent which would cause an alteration of the physical state of the serum globulins would cause an intense Abderhalden reaction, concluding that the reaction depended " upon a globulinolysis having an origin in physical processes probably analogous to the precipitin reaction. While immunologic as well as chemical and physical reactions are more or less dependent upon quantitative factors, recent investigations by Flatow2 and Herzfeld,3 Plaut,4 and others show that while specific results may be obtained by proper manipulation of the material, nonspecific results in either a negative or positive reaction may be obtained with practically any serum, however well controlled, with the same material. These investigations are significant not so much because of quantitative factors alone as they are by reason of indicating that the pregnancy reaction is dependent upon the principles of mechanical absorption on the part of the substrat of something from the serum followed by a digestive process, rather than upon the simple digestion of a specific substrat by a specific ferment. For this conception of the mechanism of the Abderhalden reaction the investigations of Jobling and Peterson5 have been fundamental and of great interest and importance. They have shown that the digestive power of a serum is dependent upon non-specific proteolytic ferments or proteases normally present and held in check by an antiferment, which, according to their work, is believed to reside in the unsaturated fatty acids of the serum. Upon removal of the antiferment by means of lipoidal solvents or saturation with various organic and inorganic substances, as boiled tissue, iodin, starch, kaolin, and the like, protease activity is released, followed by digestion, not of the so-called substrat but of the protein of the serum. Likewise Plaut,1 Peiper,2 Friedman and Schonfield,3 and Bronfrenbrenner4 have obtained positive Abderhalden reactions with guinea-pig and human sera not only with placental tissue but also with such inert substances as kaolin, starch, barium sulphate, chloroform, etc. These studies would, therefore, tend to show that the boiled placental tissue in Abderhalden's reaction is not digested, but acts simply as an absorbent in a purely mechanical manner. Furthermore, Heilner and Petri5 and de Waele6 found the ferments in the blood-serum so quickly after the parenteral introduction of the protein, at intervals hardly sufficient for the elaboration of new and specific ferments, as to support the theory that the ferments are preformed and that the substrat serves to activate these rather than bring about the production of new ferments. The researches of Van Slyke and his associates,7 employing Van Slyke's method of amino nitrogen determination, have shown that practically every serum, whether from a pregnant or non-pregnant individual, showed protein digestion when incubated with placenta tissue prepared according to Abderhalden; further evidence of nonspecificity was seen in the fact that carcinoma tissue was digested apparently to about the same extent as was placenta. Hulton,8 working with isolated and purified proteins, found no digestion with the sera of injected rabbits in excess of that which took place with the sera of normal control animals, concluding that there is at present no reason for believing that the normal hydrolysis of the protein of the body occurs in the circulating blood, but that these metabolic changes presumably belong to the tissue cells. It would appear, therefore, that the original theory of Abderhalden is untenable in that specific proteolytic ferments in the blood are not produced during pregnancy, and that the Abderhalden reaction is not due to the digestion in vitro of specific antigen by specific ferments. On the other hand, I am of the opinion that the last word has not been spoken, and while the Abderhalden test is subject to so much error as to greatly reduce its practical applications, the sera of pregnant women contain an antibody-like substance in such concentration as is not found in the sera of males and non-pregnant women. In our own experiments with Asnis and Freese, the Van Slyke method was found to be insufficiently delicate for demonstrating the difference between the sera of pregnant and non-pregant persons. In our experiments with Williams,1 while reactions occurred with the sera of pregnant women and tissue substrats other than placenta, and also with such substances as kaolin, starch, and agar, stronger reactions occurred with placental substrat; for this reason I am of the opinion that in pregnancy serum there are two sets of proteolytic ferment-like substances, one normal and non-specific and the second specific; while the former may be activated by various non-specific organic and inorganic substances resulting in the digestion of the serum, the latter are activated by the specific substrat alone, resulting in the digestion of not only the serum but also to some extent of the placental substratum itself. Bronfenbrenner2 is of the opinion that the apparently specific phase of the Abderhalden reaction is due to the specific combination of the antigen of the substratum with the antibody of the serum, leading to a change of colloidal conditions resulting in the removal of the substances which inhibit digestion. ANTITRYPSIN TEST Bergmann and Meyer1 have devised a test for estimating the titer of antitrypsin that possesses value in determining the presence of tryptic ferment hi the blood-serum and in the intestinal and stomach contents. The test may also prove of value in making a functional study of the pancreas. At present it is regarded by some as an aid to the diagnosis of cancer, and it may also be of service in establishing the diagnosis and prognosis of suppurative processes. Solution of Trypsin. — This is made by dissolving 0.5 gm. of pure trypsin (Griibler) in 50 c.c. of NaCl solution and adding 0.5 c.c. of normal soda solution; make up to 500 c.c. with physiologic salt solution. Casein Solution. — Dissolve one gram of pure casein in 100 c.c. of sodium hydroxid solution with the aid of gentle heat. Neutralize to litmus with ^ hydrochloric acid solution and dilute with physiologic salt solution up to 500 c.c. Filter and sterilize in an Arnold sterilizer. Preserve in the refrigerator. with salt solution. Dose, 0.2 c.c. Technic. — A titration of the trypsin solution must precede the test proper. Into each of several small test-tubes place increasing amounts of trypsin solution, as, for example, 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 c.c. Add 2 c.c. of the casein solution to each tube; shake carefully and place in an incubator or water-bath for half an hour at 50° C. Then add three or four drops of the acetic acid solution to each tube, and observe which tube first shows cloudiness after a few minutes. The tube containing the smallest amount of trypsin and which remains perfectly clear contains enough trypsin fully to digest the 2 c.c. of casein solution. Into each of six small test-tubes now place 0.2 c.c. of the 1 : 20 dilution of the patient's serum, and increasing amounts of the trypsin solution, beginning with the completely digesting dose, as determined above, and increasing by 0.1 c.c. Add 2 c.c. of casein solution to each tube, and bring all tubes to a like volume by the addition of normal salt solution. Shake gently, and incubate at 50° C. for half an hour. Add several drops of acetic acid solution to each tube, and again observe the tube containing the smallest amount of trypsin in which cloudiness can be seen. In this way the amount of trypsin neutralized by the antitrypsin of the serum is determined. For example, in an experiment the preliminary titration showed that 0.5 c.c. of trypsin completely digested the casein. In the second part of the test the lower limit of trypsin was this 0.5 c.c. increased by 0.1 c.c. in successive tubes up to 1 c.c. It is now found that 1 c.c. of the trypsin solution is required to bring about the complete digestion of the casein in the presence of the serum, or 1 c.c.— 0.5 c.c. =0.5 c.c., which is the amount of trypsin neutralized by 0.01 c.c. of undiluted serum. A control experiment is conducted with the pooled serum of several normal persons, and a comparison of the value thus obtained shows whether the antitryptic power of the serum tested is altered. The method of Marcus,1 which is a modification of the method of Muller and Jochmann,2 is described in the laboratory exercises on Experimental Infection and Immunity. ABDERHALDEN'S SERODIAGNOSIS OF PREGNANCY' Methods. — Two methods have been devised by Abderhalden for the demonstration of the ferments in the blood-serum of pregnancy : 1. The Dialyzation Method. — Specially prepared and coagulated placenta and fresh serum are placed in a dialyzing capsule so prepared that it will permit the passage of peptones and amino-acids only. The filled capsule is placed in sterile distilled water, and incubated for from sixteen to twenty-four hours, when the dialysate is tested by the biuret or ninhydrin test for peptones and amino-acids. Under proper conditions the presence of these substances indicates that the placental tissue has been digested by the serum. 2. The Optical Method. — This method is based upon the same principle as the dialyzation method. Into the tube of a polariscope place a solution of placental peptone and the serum to be tested. Warm the mixture to 37° C., and after an hour note the degree of rotation and record it; repeat this at intervals during the following twenty-four to forty-eight hours. If the serum contains a proteolytic ferment, the peptone is split into amino-acids and the degree of rotation increased from 0.05° to 0.5° and higher. This method requires an expensive polariscope, considerable practice in making the observations and readings, and is only reliable in skilful hands. Special shells are made by Schleichter and Schull, No. 579a being recommended at the present time. The shells must be of correct size, and every one must be tested before being used. If a shell allows uncleaved protein to pass through, then all reactions would react positively regardless of the presence or the absence of the specific ferment. If the shell is too thick and too tight, and prevents the passage of peptones and ammo-acids, then all reactions would be negative, even though the ferment were present in the serum and had digested the placental protein. Accordingly, each shell must be tested and standardized, and only those employed that have proved satisfactory. Glassware. — It is highly important that all glassware should be free from clinging particles or traces of albumin, acids, and alkalis. Pipets and dialyzing cylinders should be washed in water, alcohol, ether, and finally in distilled water, and sterilized by dry heat. Boiling rods of solid glass (10 cm. by 0.5 cm.) should be washed in alcohol, ether, and distilled water, wrapped in bundles of six in newspaper, and sterilized by dry heat. A very convenient dialyzing cylinder is shown in the accompanying illustration (Fig. 76). This cylinder measures 8 by 3 cm. It should be plugged with cotton and sterilized. When the shell is loaded with coagulated placenta and serum and covered with toluol, it will rest well beneath the surface of the outside distilled water. The wide mouth of the cylinder facilitates all manipulations and the shell cannot upset. The apparatus is easily sterilized, and the cotton plug prevents bacterial contamination and undue evaporation of the contents. practically fulfilled. Reagents. — The presence of albumin or its split products may be detected by two color reactions: (1) the biuret reaction, and (2) the ninhydrin reaction. The first is especially delicate for uncleaved albumin, and the latter for peptones and aminoacids. The technic of the biuret test is described with the technic of testing shells for permeability to albumins. name for triketohydrindenhydrate. It is a whitish yellow, readily soluble powder, dispensed in brown glass vials containing 0.1 gram of the drug. A circular describing its method of use accompanies each package. As 0.2 c.c. of a 1 per cent, watery solution is the amount necessary for a test, the contents of the vial are dissolved in 10 c.c. of distilled water, and the vial rinsed with a portion/ of the solvent. This solution should be preserved in a brown bottle in a cold place, and precautions taken to prevent infection. Triketohydrindenhydrate has been described by Ruheman,1 who gives its formula as follows: tissue and fresh serum; it is surrounded with 20 c.c. of distilled water and covered with toluol. The cotton plug prevents contamination. The cylinder is readily sterilized in a hotair oven and affords a simple and efficient means for conducting the test by the dialyzation method. Owing to the fact that it gives a blue color in the presence of any compound that possesses an ammo-group in the alpha position of the carboxyl group, it is of great value as an aid in recognizing the products of protein digestion (Fig. 77). Testing the Shell for Non-permeability to Albumin.—!. New shells should be softened by soaking them for half an hour in sterile distilled water. A dozen or more may be tested at one time. 2. The albumin solution is prepared by placing 5 c.c. of the albumin of fresh eggs in a mixing cylinder, and adding distilled water to make 100 c.c. Mix well. There must be no flakes. Instead, a clear, hemoglobin-free serum which has been dialyzed against running water to remove dialyzable substances, may be used in doses of 2.5 c.c. for each shell. 3. Carefully pipet 5 c.c. of the albumin solution into each shell. Great care should be exercised that none of the solution contaminates the outside of the shell. The preferable method is to hold the shell with a pair of broad-toothed sterilized forceps and carry the pipet to the bottom, in order that none of the albumin should contaminate the upper portion of the inside of the shell. The pipet may easily touch the edge of the shell and thus contaminate the dialysate. If in doubt, cover the upper end of the shell with the forceps and wash the outside with running water. 4. The loaded shell is now placed in a sterile dialyzing cylinder containing 20 c.c. of sterile distilled water. Never load the shell in this cylinder, for some of the albumin may fall into the distilled water. 7. Pass a sterile pipet quickly through the layer of toluol and remove 10 c.c. of the dialysate to a clean sterile test-tube, and test for albumin by the biuret reaction. Add 2.5 c.c. of a 33 per cent, solution of sodium hydroxid; shake gently, but remove the thumb from the top of the tube. The solution may become slightly cloudy. Carefully overlay with 1 c.c. of a 0.2 per cent, solution of copper sulphate in such manner that a sharp line of demarcation separates the alkaline dialysate from the copper sulphate solution. A delicate violet tint at this line indicates that albumin is present and that the shell is useless. If one cannot see this color or is in doubt, it is well to make the ninhydrin test. To do this dialysis should be continued for twenty-four hours; ninhydrin reacts FIG. 77. — NINHYDEIN REACTION (ABDERHALDEN FERMENT TEST). The tube on the left shows a positive reaction with the serum of a pregnant woman; the tube on the right is the serum control and shows a faint violet color, due, presumably, to the passage of dialyzable substances in this serum. to Abderhalden, this test is less sentitive than the biuret test. 8. All shells should react negatively, — i. e., they should not permit the passage of unchanged albumin. If the ninhydrin test is used, the tubes should be inspected one-half hour after boiling, and the contents should be as clear as water or show but the faintest blue tint. If this is not the case, shells should be discarded as being permeable to albumin. Those that are satisfactory in this respect should be tested further as follows : Testing the Shell for Permeability to Peptone. — 1. The shells should now be thoroughly cleansed, but not with a stiff brush, washed in running water, and boiled for thirty seconds. 2. Prepare a 1 per cent, solution of silk peptone (Hochst) in distilled water, and carefully pipet 2.5 c.c. into each shell, using every precaution against contaminating the upper portion on the inside, and especially of the outside, of the shell. 3. Place the loaded shell in a sterile dialyzing cylinder containing 20 c.c. of sterile distilled water, and cover the contents of the shell and water with toluol. Replace the cotton plug and incubate at 37° C. for twenty-four hours. 4. Remove 10 c.c. of the dialysate (avoid removing toluol) to a clean, sterile, thin-walled test-tube, and add 0.2 c.c. of the 1 per cent, ninhydrin solution. Insert a sterile boiling rod and boil for exactly one minute. 5. The boiling process is quite an important feature of this test. Always boil in precisely the same manner. A high Bunsen flame should be used, and about one minute after air-bubbles first appear on the sides of the tube lively boiling commences. The flame should then be turned down and the boiling continued for exactly one minute. 6. Place the tube in a rack. With a fresh sterile pipet remove 10 c.c. of dialysate from the next cylinder and test in the same manner, and repeat until the entire series have been finished. 7. After half an hour inspect all the tubes; they should show a deep blue color; if they do not do so they are impermeable or partly permeable to peptone and should be discarded. There is usually a difference in the degree of color reaction among a number of shells, as their permeability varies. 8. Those shells that have withstood both tests are now thoroughly washed in running water, boiled for thirty seconds, placed in a jar of sterile distilled water containing a few drops of chloroform, and covered with toluol. From this time on they should not be handled with the fingers, but only with forceps that have been sterilized by boiling. Of the entire number of shells, usually from 20 to 30 per cent, or more are found to be unsatisfactory. Preparation of the Placental Tissue. — This is the substratum, and should consist of coagulated placental protein free from dialyzable substances that react with ninhydrin. 1. A fresh normal placenta should be prepared soon after delivery. It is highly important to wash it free from all blood, Abderhalden having laid considerable stress upon this point. He explains that in the blood of all animals there is always a specific ferment for the red blood-corpuscles, as even the smallest hemorrhage into the tissue calls forth a protective ferment. For this reason all organs that contain blood may contain the substratum and ferment, and yield false positive reactions. 2. The placenta should be placed in warm water and freed as far as possible of clots. The membranes and cord are removed, and the placental tissue cut into pieces about the size of a dime. These are placed in a sieve under running water, and each piece squeezed with the hand. From time to time the entire mass is thoroughly squeezed out in a towel. Tissues that cannot be freed from clots should be discarded. The tissues are now crushed in a mortar, connective-tissue strands removed, and the washing continued until the tissue is snow white. Decolorizing substances, such as H202, should not be used. If the tissue is not white and free from blood it should not be employed. Liver, spleen, and kidney tissue cannot be made perfectly white, although all traces of blood have been removed. 3. Place 100 times as much distilled water as there is tissue in an enameled vessel; to each liter add five drops of glacial acetic acid and heat to boiling, when the tissue is added and boiled for ten minutes. 4. Wash the coagulated tissue with distilled water, and boil again without the addition of acid. This should be repeated six times in succession. If an interruption occurs, cover the tissue and water with a layer of toluol. 5. After the sixth boiling add a small quantity of water to the tissues — just sufficient to enable it to boil for about five minutes without burning, for the water is now to be tested with the ninhydrin reaction and it is important that this be as concentrated as possible. Filter the water, and to 5 c.c. in a sterile test-tube add 1 c.c. of the ninhydrin solution. Boil vigorously for one minute. If there is the slightest discoloration within half an hour, the tissues must be boiled again, but with only five volumes of water and no longer than five minutes each time. These boilings should be repeated as often as is necessary until the ninhydrin reaction remains water clear for at least one-half hour. carded. 7. The tissue is now preserved hi a sterile jar containing sufficient sterile water and chloroform and covered with toluol. All tissue should be handled with sterile forceps, and when once removed from the jar, they should never be returned. The whole operation requires several hours and it should be conducted without interruption. If the process is interrupted, the tissue should be covered with a layer of toluol. tions: (1) It must contain the smallest amount of dialyzable substances that would react with ninhydrin. Blood is best drawn in the morning before breakfast. In all diseases accompanied by marked protein disintegration, such as cancer, the blood-serum may contain large amounts of dialyzable substances. contain millions of erythrocytes. 1. From 10 to 20 c.c. of blood are withdrawn from a vein at the elbow with a dry sterile needle into a sterile centrifuge tube. This is placed aside at room temperature for several hours, when sufficient serum has usually separated out; if this has not occurred, centrifuge for several minutes. The serum is removed to a second sterile centrifuge tube, and centrifuged at high speed for several minutes until all corpuscles have been precipitated to the bottom of the tube. 2. The serum should be used within twelve hours after the blood has been withdrawn. Abderhalden claims that heating a serum to 60° C. robs it of its digesting powers. Pearce and Williams have found that altogether. 3. Specimens of blood sent through the mails are really unsatisfactory, for even if they are delivered within twelve hours after bleeding, the amount of handling has usually resulted in the breaking up of a number of corpuscles and the tinging of the, serum with hemoglobin. The Test. — 1. Absolute cleanliness should be employed. The glassware should be sterile and dry, and everything should be in readiness. The technic should be aseptic and thoroughly understood. 2. Remove a sufficient amount of the prepared placenta for the work at hand with sterile forceps and wash in a dish of sterile distilled water to remove toluol and chloroform. Boil with 4 or 5 volumes of sterile distilled water for two minutes and test the water with ninhydrin. If positive, the tissue must be boiled as described above until free of ninhydrin reacting substances. Place on sterile filter-paper, and squeeze to remove any excess of water. Weigh and place 0.5 gram in each of two shells (one for a control). 3. Holding each shell with a second pair of boiled forceps, pipet 1.5 c.c. of the patient's serum into one shell containing placenta, and the same amount into a third shell which is to serve as a control on the serum. Place 1.5 c.c. of sterile distilled water in the placenta! tissue control shell. 4. Unless one is absolutely sure that neither the tissue nor the serum has touched the outside of the shells, they should be held shut with sterile forceps and washed with sterile distilled water. 5. Each of the three shells is now placed in cylinders containing 20 c.c. of sterile distilled water. Under no circumstances are the shells to be loaded while they are in the dialyzing cylinders. 6. The contents of each shell and the water surrounding them are covered with a layer of toluol about J4 inch in depth, and the cylinders plugged with cotton to prevent evaporation and contamination. The shell should be at least M to J/2 mch above the level of the outside fluids, and due care must be exercised in carrying the cylinder back and forth from the incubator that the contents of the shell and the surrounding water do not become mixed. rate sterile pipet and placed in sterile test-tubes of the same size and boiled with 0.2 c.c. of the 1 per cent, ninhydrin solution for exactly one minute. After standing for half an hour, the readings are made. Bronfenbrenner's Modification. — Bronfenbrenner1 has resolved the technic of the test into two distinct phases : The first comprises a sensitization of the substrat by the specific elements of the immune serum at a low temperature, with the resultant absorption of antiferment; the second is the autodigestion of the serum at 37° C. In conducting the test 0.5 gram of prepared placenta is mixed in a sterile tube with 1.5 c.c. serum and held in the cold for sixteen hours. The clear serum is then secured by thorough centrifuging and placed in a dialyzing thimble in distilled water as described above, incubated for eighteen to twenty-four hours, and the dialysate tested with ninhydrin. As a further test the substrat may be washed twice with sterile distilled water by centrifuging to remove all traces of serum and placed in a dialyzing thimble with 1.5 c.c. fresh male guinea-pig serum. The test is then conducted in the same manner as the regular Abderhalden technic and the usual controls are included. It would appear that this modification has increased the specificity of the test. Reading the Reaction. — The dialysate of the serum alone should be clear as water or show but the faintest blue tinge. The dialysate of the placenta alone should be clear; the dialysate of the patient's serum plus that of the placenta may show a deep violet-blue color when the reaction is strongly positive, or a fainter blue when it is weakly positive. If this dialysate is water clear or has a faint blue color, comparable to the controls, the result is negative. If there is any doubt, the test should be repeated. The negative control should be water clear or have a faint tinge comparable to its control. The positive control should show a deep violet-blue color. I generally control the result given by the shell containing tissue and patient's serum by cleansing it thoroughly, boiling for a minute, and testing it with egg-albumen solution or a serum, in case the reaction was positive, to make sure that the shell has not allowed the passage of serum, or with peptone solution, in case the reaction was negative, to make sure that it was not thick enough to block the passage of peptones and amino-acids. This procedure delays the report on a serum for another twenty-four hours, but the greater accuracy obtained warrants the delay. the ninhydrin reaction. Sources of Error in the Dialyzation Method. — There are many sources of error, and until the technic has been improved sufficiently to eliminate these, Abderhalden's directions should be followed minutely. 1. The shells may become spoiled in time. They should not be cleansed with rough brushes or boiled too long. They should be cleansed at once after using, and tested every four weeks. If a wrong diagnosis results, the shell should be retested at once. puscles. 4. The controls on placenta alone and each serum alone are absolutely necessary, as both may contain various substances capable of reacting with ninhydrin and thus yielding false positive reactions. 5. The water used should be distilled and sterile. The glassware should be chemically clean and sterile, and the laboratory free from the fumes of acids and alkalis. It is very important that absolutely the same conditions should exist for the control tests as for the main test itself. THE OPTICAL METHOD In the dialyzation method, we establish the transformation of a colloid into a diffusible crystalloid; in the optical method we start, for purely technical reasons, not with the whole protein molecule, but with a peptone prepared of placental protein. The unsplit protein itself cannot be used, as this will interfere with the determination of the rotation of the mixture of substratum plus serum. Further, in such mixtures precipitation may occur and render the readings difficult. Instead, we transform the protein into peptone, and observe the final changes in the tube of the polariscope. Placental Peptone. — This requires considerable care in its preparation. Placental peptone may be purchased of the Hochst Farbwerke, and is expensive. Each specimen should be tested and its rotation determined, as otherwise uncertain and unreliable results may be secured. According to Abderhalden, a peptone may be prepared as follows: white, as in the preparation of tissues for the dialyzation method. The tissue is freed of any excess of water by pressing it through several layers of filter-paper, and the process of hydrolysis is begun. If a larger quantity of the same tissue is to be collected, the pieces are prepared as they are secured by washing them free from blood, boiling in water for ten minutes, and preserving in a stock jar containing sterile water and chloroform, and covered with toluol. The tissues are boiled in order to destroy the cell ferments and to prevent autolysis. The tissues are now weighed, placed in a large flask, and treated with three volumes of cold 70 per cent, sulphuric acid. The flask is well shaken and carefully stoppered, and placed aside at room temperature (not higher than 20° C.) until the tissues have gone into solution. The flask is shaken occasionally. Solution is usually completed within three days. The flask is now placed in iced water and treated with 10 volumes of distilled water added slowly so that the temperature does not rise above 20° C. The sulphuric acid is now precipitated with pure crystallized barium hydroxid until the solution gives no precipitate with either the hydroxid or sulphuric acid. A precipitate of a barium salt of peptones may appear in spite of the fact that no sulphuric acid is present. This precipitate is soluble in nitric acid, whereas barium sulphate is not soluble. The neutralization point is controlled with litmus paper. Small portions are then filtered through filter-paper and tested, first with barium hydroxid and then with sulphuric acid. If a turbidity develops on testing with the barium hydroxid, nitric acid is added and the whole gently warmed. If the precipitate persists, it is evident that more barium sulphate should be added. The final neutralization is effected with dilute sulphuric acid and barium hydroxid. When the solution is free from sulphuric acid, the precipitate of barium sulphate is secured by filtering through filter-paper or by centrifugalization. It is then worked up in a mortar with distilled water and again filtered. It is well to repeat this washing once more. The peptone solution is now concentrated in a special apparatus that permits evaporation of the solution under diminished pressure and at 40° C. A special drop funnel delivers the peptone solution drop by drop and thus prevents foaming. The yellowish, syrupy residue that remains is covered with 100 volumes of methyl alcohol and boiled. The boiling hot solution is then filtered through five thicknesses of filter-paper into five volumes of cold ethyl alcohol, which is kept in ice water. Precipitation may be accomplished by the addition of ether. Just as soon as the precipitate has formed it is filtered out, preferably through a porcelain filter. The filter is then placed in a vacuum desiccator, and after one or two days the peptone is dry and easily removed and weighed. Testing the Peptone. — One cubic centimeter of fresh, clear, hemoglobin- and corpuscle-free serum from a man and an equal amount of a 5 to 10 per cent, solution of the peptone are placed in a sterile polariscope tube, warmed to 37° C., and the rotation read. If marked changes occur, the peptone is not free from sulphuric acid or barium hydroxid. With the serum of pregnancy, readings should be taken each hour for six hours, and then at intervals of from thirty-six to forty-eight hours. Peptones of other tissues and bacteria may also be prepared. The Polariscope. — A perfect and delicate instrument is necessary, that of Schmidt and Hansch, Berlin, being recommended by Abderhalden. The instrument must be delicate enough to record differences in rotation of 0.01 p, and be furnished with an electric incubator attachment for keeping the tube at a constant temperature of 37° C. The tubes may, however, be kept in a bacteriological incubator, removed, quickly read, and then returned. The Test. — One cubic centimeter of fresh and absolutely hemoglobin- and corpuscle-free serum is placed in the polarization tube with 1 c.c. of a 10 per cent, solution of standardized placental peptone; sufficient sterile saline solution is added to fill the tube. The tube is then placed in an incubator at 37° C. for an hour, and a reading made. Another reading is taken an hour later, and the two readings should not show more than a minute difference in rotation. Another reading is made at the end of six hours, and others at intervals during the next thirty-six or forty-eight hours. Reading the Reaction. — In serums of pregnancy cleavage is usually apparent at the end of six hours, and rotation may amount to 0.05° to 0.2° in thirty-six hours. With non-pregnant serums the rotation is seldom more than 0.03°. for error. A large margin for error will result if the primary reading is taken when the tube is cold, as it is immediately after being filled. Only that reading taken after the tube has been in the incubator for at least one or two hours is to be taken as the guide for determining the amount of digestion according to the degree of -rotation. The greatest source of error lies in the observer himself. One must be trained to make the readings in about thirty seconds; the eye soon grows tired, and the readings are then unreliable. PRACTICAL VALUE OF ABDERHALDEN'S PREGNANCY TEST 1. It may be definitely stated that this test has failed to establish itself as possessing value in the diagnosis of pregnancy. When per- formed by a competent serologist following all the prescribed precautions, satisfactory results may be obtained in some cases, but errors beyond the immediate control of the serologist are prone to be present and greatly limit the practical value of the test. 2. As the test is more likely to yield falsely positive than negative results, a negative reaction is of some value in excluding pregnancy, and particularly in those occasional cases presenting tumors in the lower abdomen which may be due to advanced pregnancy or a neoplasm. 3. The reaction may appear in the middle of the second month, and disappear in from ten to fifteen days after pregnancy has been interrupted, regardless of whether the fetus is born before, at, or after the normal period of gestation. This test has generally failed, however, to reliably detect pregnancy at a time when such a test is mostly needed, namely, in the early stages and when the clinical diagnosis is doubtful. 4. As it stands at present, the Abderhalden test has only a scientific interest, but is worthy of further investigation; it has greatly stimulated the study of the fermentative activities of the body fluids and particularly of the blood. Cancer. — Freund and Abderhalden1 claim to have found ferments in the serum of cancer that will digest coagulated cancer protein in the same manner as the ferments in pregnancy digest placental protein. Frank and Heiman2 reported positive results in 53 of 54 cases of cancer; Markins and Munze,3 Epstein,4 Gambaroff,5 Erpicum,6 Brockman,7 Lampe,8 Lowy,9 Ball,10 and others have reported highly favorable results. Frankle11 and Lindig12 have found the reactions generally non-specific in character. Either the dialyzation or the optical method may be used in conducting these tests, precisely the same technic being followed as in making the pregnancy tests, except that several different cancer tissues should be that of various benign tumors. Mental Diseases. — Fauser1 has studied the serums of 88 cases of dementia pra?cox and other mental diseases with various antigens composed of the ductless glands, testicles, ovaries, etc., and attained interesting results, tending to show that in many of these brain affections there may be associated lesions in other organs, and that the symptoms may be due to perverted functions of certain ductless glands. Munzer,2 Bundschue and Roener,3 and Fisher4 have also found in the serums of mental and nervous diseases ferments for the protein of the ductless and generative glands, tending to show that lesions of these organs may be operative in the symptomatology of these conditions. Syphilis. — Baeslack5 has reported having had exceptionally good results with the serums of syphilitics and a substratum composed of coagulated syphilitic lesions of rabbit's testicle. Using the dialyzation method, he found the sero-enzyme test more constant and earlier than the Wassermann reaction. Tuberculosis and Acute Infections. — Abderhalden and Andryewsky6 have suggested the use of the dialyzation or the optic method in the diagnosis of acute infections. The peptone may either be prepared of the bacilli, or the boiled organisms used in the dialyzing shell. In preparing a bacterial substratum, the material must be carefully centrifuged in order to facilitate washing. The tubercle bacilli are degreased by extraction in fat solvents. According to Abderhalden, the presence of ferments in acute infections indicates that the animal is defending itself. Abderhalden and Andryewsky found ferments present m the serum of cattle receiving injections of suspensions of dead tubercle bacilli and in experimental infections, and suggest that the test may prove efficacious in testing cattle. This work should receive further study in human infections. Smith,7 employing Bronfenbrenner's modification of the Abderhalden test, has reported highly specific results in the differentiation of various bacteria with rabbit immune sera. AGGLUTININS As previously stated, given any infection,' several antibodies of different properties may be produced. If the infecting microorganism produces characteristically an exogenous toxin, as, for example, that produced by the diphtheria bacillus, an antitoxin is produced as the most prominent of several antibodies. With other pathogenic bacteria that produce mainly an endogenous toxin various antibodies are formed, and one or more may play a prominent role in protecting the host, such as opsonins, agglutinins, precipitins, bacteriolysins, etc. If typhoid immune serum from an immunized animal or a patient suffering from typhoid fever is added to an emulsion of typhoid bacilli in a test-tube and the mixture placed in an incubator, the following phenomenon will be observed: the bacteria, which previously formed a uniform emulsion, clump together into little masses, settle at the sides of 'the test-tube, and gradually fall to the bottom, the fluid becoming almost clear. In a control test to which no active serum is added, the fluid remains uniformly cloudy. If the reaction is observed microscopically in a hanging drop, it is noted that with the addition of the serum the bacilli move nearer and nearer one another, this process being followed by a gradual loss in motility and the formation of clumps. The substance in the serum causing this phenomenon is called agglutinin, and the reaction is known as agglutination. Definition. — Agglutinins are antibodies that possess the power of causing bacteria, red blood-corpuscles, and some protozoa (trypanosomes) suspended in a fluid to adhere and form clumps. Historic. — Although Metchnikoff, Charrin, and Roger had noticed peculiarities in the growth of Bacillus pyocyaneus when cultivated in immune serum which we now believe were due to agglutinins, Gruber and Durham and Bordet (1894-1896) were the first to recognize that the agglutination reaction was a separate function of immune serum. While investigating the Pfeiffer phenomenon of bacteriolysis with Bacillus coli and the cholera vibrio, these investigators found that if the respective immune serums were added to bouillon cultures of these two species, the cultures would lose their turbidity, flake-like clumps would form and sink to the bottom of the tube, and the supernatant fluid would become clear. Gruber at the same time called attention to the fact that agglutinins were not absolutely specific for their own antigen, but would agglutinate, to a lesser extent, closely allied species of bacteria. In 1896 Pfaundler drew attention to a peculiar phenomenon observed when bacteria were grown in an immune serum. Long and more or less interlaced threads of bacteria developed, which were regarded as due to agglutinins. At that time considerable emphasis was laid upon the importance of Pfaundkr's reaction, but at present the ordinary nostic procedure. In 1896 Widal and Griinbaum first turned these facts to practical use in the diagnosis of typhoid fever. These investigators found that the serum of patients suffering from typhoid fever acquires a high agglutinating power for Bacillus typhosus, and since this phenomenon generally manifests itself comparatively early in the disease, its recognition has considerable diagnostic importance. It is purely accidental that we speak of the "Widal reaction" in typhoid fever, rather than of the "Griinbaum reaction," for the latter observer conducted similar studies him in the publication of a more extensive work. At the present time this diagnostic reaction is known as the GruberWidal reaction. It has proved of great value to a large number of different investigators, not only in making the serum diagnosis of typhoid fever, but in other infections as well. Normal and Immune Agglutinins. — Normal serums are frequently capable of agglutinating bacteria, such as the typhoid, colon, pyocyaneus, and dysentery bacilli. In some cases the typhoid bacillus may be agglutinated in dilutions as high as 1 : 30, a point of practical importance in the clinical use of the test. When a normal serum is found to have a high agglutinating power, it is probable that a previous infection by the microorganism has occurred. Since the serum of a new-born child is largely devoid of agglutinins that are found in later life, the so-called normal agglutinins may, after all, be acquired properties. bearing or haptophore group that unites with the agglutinin, except antigen, but they differ from them in having also a phore^r zymophore functional or agglutinophore group that agglutinates grouP is lostthe antigen when this union has occurred (Fig. 79). Agglutinins that have lost their zymophore or agglutinophore group through the action of heat, age, acids, etc., but that still possess their haptophore group, are called agglutinoids, just as toxins that have lost their toxophore group are called toxoids. Such agglutinoids, then, may still combine with the bacteria or blood-cells without being able, however, to produce agglutination (Fig. 80). It is found, at times, that even a fresh serum, when concentrated, will cause less agglutination than when it is diluted. This is ascribed to the presence of agglutinoids, which have a stronger affinity for agglutinogen than has the agglutinin. When producing a reaction of this character they are called pro-aqglutinoids. When the serum is diluted, the pro-agglutinoids become less concentrated, and finally, when they are diluted as to have no influence on the reaction, the agglutinins are still present in sufficient quantity to bring about agglutination. As a practical fact, in agglutination reactions the action of pro-agglutinoids is of much importance, for the inexperienced may be misled by the absence of or by poor agglutination in lower dilutions to neglect the use of higher dilutions (see Fig. 86). The substance in bacteria or other cells that produces agglutinin is called agglutinogen. It appears to be formed in the cell, and in some cases may be excreted into the surrounding medium. Certainly when bacteria die and become disintegrated, agglutinogen is liberated and the filtrates (entirely free from bacterial cells), when injected into animals, will cause the formation of agglutinins. sidered as having a simple haptophorous group, through which it may unite with the receptors of the tissue-cells. This haptophore comes into play again in the union between agglutinogen and agglutinin, which precedes agglutination. It is a passive body, similar to uniting either with cell or with agglutinin. Origin of Agglutinins. — The investigations that have been carried out for the purpose of determining the site of formation of agglutinins have not thus far yielded conclusive results. The lymphoid tissues appear especially concerned, agglutinins being found early in the bonemarrow and the spleen (Pfeiffer and Marx). Metchnikoff believes that agglutinins may be derived from leukocytes and endothelial cells. It is more probable, however, that the formation is general, and is the result of wide-spread cellular activity. NINS AND AGGLUTINOIDS. In the first tube (left) most of the bacilli (B) have been agglutinated and massed in the bottom of the tube by the agglutinins (a). bacilli (B) are in combination with the agglutinoids (A), but agglutination does not occur because the agglutinophore groups are lost. A few bacilli have been agglutinated by the agglutinins (a). ACID AGGLUTINATION 283 In accordance with the side-chain theory, the ability of an animal to form agglutinins for a certain microorganism would depend on its possession of receptors of the second order, which are able to unite with the . > agglutinogenic receptors of the microorganism. It has been well es- I/ tablished that the number of such suitable receptors vary in animals, and that different animals may not produce serums with equal agglutinating powers. Properties and Nature of Agglutinins. — (1) Agglutinins are fairly resistant substances that withstand heating to 60° C. for thirty minutes and lose their power only when heated to higher temperatures. It is possible, therefore, to make a serum bacteriolytically inactive by de- K stroying complement at 55° C., and still retain its agglutinating power. state. They do not dialyze through animal membranes. (3) They are precipitated from a serum by magnesium or ammonium «/ sulphates, when these salts are used in proper concentration, and are thus closely associated with the globulin fraction of serum. (4) They are separate and distinct antibodies, and are not associated with bacteriolysins. Thus the agglutinins of an immune serum may be lost, destroyed, or absorbed and the bacteriolysins retained. As previously mentioned, the bacteriolytic power of a serum may be inhibited by heating it to 55° C. for one-half hour without influencing the agglutinin content, and during disease processes the formation of agglutinins and that of bacteriolysins are apparently not parallel processes. Acid Agglutination. — Bacteria may be agglutinated by acids, and the method of acid agglutination was introduced by Michaelis1 for the differentiation of bacterial species on the basis that the hydrogen ion concentration at which agglutination is maximal is characteristic for various species of closely allied types. The results of considerable investigation on the acid-agglutination of the typhoid-colon group of bacilli has shown that Bacillus typhosus and Bacillus paratyphosus are readily distinguished by means of the reaction. Definite differentiation between the paratyphoid bacilli A, B, and C have not been seen by Beniasch,2 Jaffe,3 Heinmann,4 and Grote5; Beniasch has also reported the resistance of Bacillus coli to acid agglutination at any hydrogen ion concentration, and, indeed, he has found certain strains of nearly all species of bacteria to be non-agglutinable within the tested reaction limits. Gillespie6 found that pneumococci belonging to the serologic (/ types I and II have, as a rule, narrow zones of agglutination. The optimum hydrogen ion concentration was found different in the two cases, while other pneumococci had broad zones or, in a few cases, narrow zones not coincident with those occupied by the typical organisms. For a technic of acid agglutination see page 310. 1. Gruber's idea of the mechanism of this phenomenon was that the agglutinin so changed the bacterial membrane as to render it more viscous, and that this increased viscosity caused the bacteria to adhere and form clumps. No visible changes in the organisms or red corpuscles can, however, be seen. 2. Paltauf's theory is somewhat similar, he believing that the agglutinogen is precipitated on the surface of the bacteria by union with the agglutinin, with the formation of a sticky substance. He cites evidence that tends to show that such substances are actually thrown out from the bacteria during agglutination, as may be seen in a properly stained preparation in the form of a precipitate surrounding the bacterial cells. 3. The presence of some salt is necessary for the occurrence of agglutination. Bordet found that if the salts were removed from the serum and from the suspension of bacteria by dialysis and that the two were then mixed, agglutination did not occur, but that if a small amount of sodium chlorid was added, agglutination promptly took place. According to this view, therefore, agglutination is a phenomenon of molecular physics — the agglutinin acts on the bacteria or other cells and prepares them for agglutination by altering the relations of molecular attraction between them and the surrounding fluid, the second phase, the loss of motility, clumping, etc., being brought about by the presence of salt. This second phase, therefore, would be a purely physical phenomenon, the salts altering the electric conditions of the colloidallike agglutinin-bacterium combination, so that their surface tension is increased. To overcome this the particles adhere together, presenting in a clump less surface tension than if they remained as individual par- DIFFERENTIATING BETWEEN A MIXED AND SINGLE INFECTION 285 tides. Bordet cites the precipitation of clay as an analogous case: if a little salt is added to a fine emulsion of potters' clay in distilled water, the clay immediately clumps and falls to the bottom, the resemblance between these flakes and the clump of agglutinated bacteria being very striking. Specificity of Agglutinins. — For a time after their discovery the agglutinins were regarded as strictly specific, i. e., a typhoid-immune serum would agglutinate only typhoid bacilli and no others. Gruber early pointed out that an immune serum will frequently agglutinate other closely related organisms, although not usually to so high a degree. Group or partial agglutinins, therefore, refer to the presence in a serum of certain agglutinins that agglutinate certain other microorganisms that are morphologically, biologically, and often pathogenetically closely related to the homologous microorganism (the bacterium causing the infection or used in artificial immunization). For example, a typhoid-immune serum possesses, besides its greatly increased agglutinating power for Bacillus typnosus, some agglutinin for Bacillus paratyphosus, notably above that of normal serum. This is explained by the very close biologic relationship of these bacteria, together with the fact that the agglutinin-producing substance (agglutinogen) is a complex and not a single chemical substance. This has been explained by Durham in the following example : If the typhoid agglutinogen is composed of various elements, A, B, C, D, it is conceivable that the closely related paratyphoids might contain one or more of these four agglutinogens, and, therefore, the agglutinating power of the typhoid serum for a paratyphoid bacillus, though not so great as on the typhoid bacillus, is still considerable. Accordingly, in an infection with one microorganism a specific agglutinin will be formed for that microorganism, and group agglutinins for other more or less allied microorganisms, and consequently the specificity of the agglutinating reaction depends upon the principle of dilution, the specific agglutinin being present in largest amount and operative in dilutions above the range of the group agglutinins. Absorption Methods for Differentiating Between a Mixed and a Single Infection. — In 1902 Castellani discovered that if the serum of an animal immunized against a certain microorganism contains that microorganism in large numbers, the serum will lose its agglutinating power not only for that microorganism, but also for all other varieties on which it formerly acted. If, however, the serum contains the organism corresponding to the group agglutinins, the agglutinating power of the serum for the homologous organism is reduced but little or not at all. In a mixed infection due to two or more varieties of bacteria there iwill be specific agglutinins for each of the microorganisms, and group agglutinins for each of them as well. If the immune serum is saturated with one of these varieties its chief or major agglutinins and some or all of the group agglutinins will be removed, but the major agglutinin of the second species will remain. On the addition of the second bacterium to the immune serum agglutination occurs and its agglutinin is absorbed. Park, who has carefully investigated this subject, finds that the absorption method proves that when one variety of bacteria removes all agglutinins for a second, the agglutinins in question were not produced by the second variety. Hemagglutinins. — Agglutination, like other immunity reactions, is a manifestation of broad biologic laws and is not limited to bacteria. As hemolysins are produced by the injection of an animal with red bloodcorpuscles from another species, so agglutinins that agglutinate the red blood-corpuscles may be developed at the same time. When a serum containing hemagglutinin is added to a suspension of the corresponding red blood-corpuscles contained in a test-tube, it causes these to collect into clumps and flakes and sink to the bottom, just as a typhoid immune serum agglutinates typhoid bacilli. These clumps are broken up with some difficulty, and may interfere with hemolytic reactions. They are especially to be observed in antihuman hemolytic serums when agglutination may be so marked as to prevent hemolysis unless the tubes are frequently and vigorously shaken. Small amounts of normal hemagglutinins may be found. Of particular practical importance are those for animals of the same species, the so-called isohemagglutinins. Isohemagglutinins and their Relation to Blood Transfusion. — Isohemagglutinins were discovered independently by Landsteiner,1 and Shattuck in 1900, and have been studied quite extensively by Hektoen, Ottenburg,2 Moss,3 Gay, Brem,4 and others. At first the occurrence of isoagglutination was regarded as of pathologic signifiance, but later researches showed that they may be found in a large percentage of normal bloods. According to Landsteiner, human bloods may be divided into three groups; the fourth group was discovered independently by several observers. This group includes about 50 per cent, of all persons. Group 2 : In this group the corpuscles are agglutinated by the serums of groups 1 and 3 only, whereas the serums agglutinate the corpuscles of groups 3 and 4, but not of Group 1. Moss found that all normal and pathologic bloods alike could be classified into four groups by agglutination tests of the serums against the corpuscles. These groups are: 1, 2, and 3, not 4. Corpuscles not agglutinated by any serums. It may be seen that no serum agglutinates corpuscles belonging to its own group, and furthermore, that if one has a known Group 2 or Group 3 blood, he can determine the group of any other blood by testing the known serum against the unknown corpuscles, and the unknown serum against the known corpuscles. Because reactions may follow transfusion if the bloods of donor and recipient are incompatible it is advisable to apply these preliminary tests; the technic is described on page 311. With the increasing number of blood transfusions, the phenomena of isoagglutination and isohemolysis — the two being closely related — are of considerable practical importance, especially if the patient is suffering with cancer, when the serum is likely to be actively hemolytic for the donor's corpuscles. tests should always be made before operation if time permits. The tests made in vitro are usually safe guides as to conditions existing in vivo, and such preliminary tests may prevent the occurrence of untoward symptoms associated with intravascular hemolysis or agglutination, such as fever, dyspnea, edema, and hemoglobinuria. As a rule, the donor selected should be a near relative, and whenever time permits, a Wassermann reaction and the isoagglutination and isohemolysin tests should be made. That donor should be chosen whose blood shows no inter-agglutination or hemolysis with the patient's serum and corpuscles. If such a donor cannot be obtained, it is safer to use a person whose serum is agglutinative toward the patient's cells than one whose cells are agglutinated by the patient's serum. chapter. Non-agglutinable Species of Bacteria. — Certain species of bacteria, especially when freshly isolated from the animal body, may prove themselves immune to the action of agglutinins; this is true especially of the bacillus of Friedlander. As a rule, this resistance is lost when the microorganism is grown for some time in artificial media. In some instances the typhoid bacillus, when freshly isolated from a patient, may resist agglutination until after it has passed a period of existence on artificial media. This variability is probably due to some change taking place in the agglutinable substance of the agglutinins during the sojourn of the bacilli in the animal body, and possess such an excess of agglutinogenic receptors as to require a much larger amount of agglutinin to cause agglutination. It should be remembered that agglutinins act on dead as well as on living bacteria, those killed by heat, formalin, phenol, etc., being similarly agglutinable. In making the microscopic test the use of dead bacteria is not so satisfactory as when the test is made with living motile bacteria, for the influence of the serum on motility alone is of value in interpreting a reaction. Variation in Agglutinating Strength of a Serum. — In a given infection, such as typhoid fever, there is usually a continued increase in the amount of agglutinin in the blood from the fourth day until convalescence is established, and then a decrease occurs. It is a fact of practical importance that the agglutinating power of a serum may vary from day to day, so that it is very strong one day and may become weak or disappear entirely on the next day or two. Hence the importance of making more than one test in a suspicious case when the first trial has been by some as responsible for it. Conglutination. — In 1906 Bordet and Gay1 described a colloidal substance in beef serum heated to 56° C. which has the property of causing a characteristic clumping and increased lysis of red blood-cells when treated with a heated specific hemolytic serum and fresh alexin (complement). Bordet and Streng,2 in later studies on this substance, gave to it the name "conglutinin." Streng3 continued these studies with bacteria and found that a typical clumping was produced by the mixture of bacteria, fresh complement, conglutinin, and a specific immune serum from which the agglutinins had been removed by absorption. By dialyzing the beef serum the conglutinin was shown to be present in the globulin fraction, and the reaction took place as well with bacteria killed by heat or 0.1 per cent, liquor formaldehydi as with live organisms. In a study of dysentery in infants, Lucas, Fitzgerald and Schorer4 first applied this reaction to clinical diagnosis. They found it more sensitive and specific than either the agglutination or fixation test. In their work cultures of the Flexner and Shiga dysentery bacilli treated with 0.1 per cent, liquor formaldehydi were used. They conclude that in the conglutination test we have a means of diagnosis far superior to any other form. The technic of this reaction is given on page 307. R8le of Agglutinins in Immunity. — The agglutinins were formerly regarded as possessing a true protective and curative power. It has previously been mentioned that bacteria may be grown in a specific agglutinating serum, and cultures made of agglutinated bacteria show them to be fully alive and as virulent as before agglutination took place. In certain cases agglutinins for a microorganism may be entirely absent, and yet the animal enjoy an immunity. Bacteria that have been acted upon by an agglutinin are apparently not altered in appearance, viability, or virulence. serum gives no indication of the degree of immunity that exists. For instance, relapses may occur in typhoid fever at a time when the agglutinating power of the patient's blood is at its highest. At present agglutinins are regarded as playing a subsidiary role in immunity, their presence being of diagnostic value, and an indication of the presence of more important factors, and as an aid to bacteriolysis, and phagocytosis.. As shown by Bull1 experimentally, agglutination may occur in vivo, and the power of the blood to cause agglutination determines, in large measure, whether after their direct introduction in an experimental way the bacteria are to be removed promptly from the circulation and bacteremia avoided, or whether they are to remain and produce bacteremia. Microorganisms which are not agglutinated in the normal rabbit may be made to do so by the intravenous injection of homologous immune serum, and this probably explains the rapid disappearance of pneumococci from the blood following the intravenous injections of homologous antipneumococcus serum. The bacterial clumps accumulate in the organs in which they are phagocyted. In this wray it appears that agglutinins, opsonins, and phagocytosis are closely related and probably exert an important role in resistance to. and recovery from, infection. The agglutination reaction is used for the following purposes: 1. For the diagnosis of disease, by identifying the bacterial infection from which the patient is suffering. To do this satisfactorily we must have on hand stock cultures of bacteria, and test the patient's serum for agglutinins for these bacteria. For instance, if a patient presents symptoms of typhoid fever, the serum is tested for typhoid agglutinins; if the reaction is very weak or negative and continues so, the serum is further tested for agglutinins for Bacillus paratyphosus A and B. In typhoid fever the Gruber-Widal reaction may be positive as early as the third day; usually, however, the positive reaction is obtained somewhat later — about the seventh or the eighth day. A day or so earlier the bacilli used in making the test may be seen to lose their motility, and two or three may form a loose clump. This is the doubtful reaction, and it is well to test every day or every other day until a decisive reaction is obtained. positive reactions in the first week; about 60 per cent, in the second week; about 80 per cent, in the third week; about 90 per cent, in the fourth week, and about 75 per cent, in the second month of the disease." In about 90 to 95 per cent, of cases in which repeated examinations are made a positive reaction is to be found at some time during the patient's illness. Occasionally the reaction appears first during the stage of convalescence, and at times it may even be absent, the diagnosis being confirmed by cultivating typhoid bacilli from the blood. The possibility of a given case reacting strongly one day and weakly or entirely negative a day or so later has been emphasized elsewhere. Usually the reaction is strongest during convalescence, remains positive for several weeks, and then gradually returns to the normal. Occasionally the reaction remains positive for months or even years after the attack of typhoid fever — many such cases are " carriers" and harbor the bacilli in the gall-bladder, although the person appears to be quite well. Only very rarely does normal serum immediately agglutinate typhoid bacilli in a dilution higher than 1:10; where a time limit of one to two hours is given, a few may show some agglutination in dilutions up to 1 : 30. If the typhoid bacillus is agglutinated by the patient's serum in a dilution of 1:100, or at least 1:40, the Widal reaction may be regarded as positive. It is not safe to use lower dilutions, as occasionally the serum of healthy persons may agglutinate Bacillus typhosus in dilutions up to 1:30. Due care must be exercised not to mistake a pseudoreaction about detritus for true agglutination. Positive reactions are occasionally obtained in other diseases — acute miliary tuberculosis, malaria, malignant endocarditis, and pneumonia. It is also well to bear in mind the possibility of a patient having been vaccinated against typhoid at some early date, with resulting agglutinin formation. Owing to the similarity of symptoms an infection with Bacillus paratyphosus A and B may be difficult to distinguish from typhoid fever. This difficulty is increased by the confusion of the Widal reaction owing to the presence of group agglutinins in the serum if proper dilution is not practised. Bacillus A and Bacillus B are not identical in their agglutinable properties, the latter being more closely related to the typhoid bacillus than the former. In this country Bacillus paratyphosus is usually held responsible for paratyphoid fever. Conclusions should not be drawn until tests have been made with both strains of the para- diagnosis. In dysentery the agglutination reaction with the serum of patients shows great variability. In spite of the presence of bacilli in the feces ithe reaction is sometimes absent, often disappears rapidly during convalescence, and rarely is as high as in typhoid fever. The tests should always be performed with both the "Flexner" and "Shiga" types of bacilli, as the two do not possess identical agglutinable properties, and either may be the cause of infection in a given case. The absence of the reaction does not exclude a dysenteric infection. In cholera the agglutination test has so far proved of doubtful aid in establishing a diagnosis of the disease. However, for the purpose of recognizing bacilli isolated from the feces of suspicious cases the reaction with known immune serum is of great value. In cerebrospinal meningitis the agglutination occurs within an hour in dilutions of 1 : 10. It is seldom that the patient's serum agglutinates in a dilution higher than 1 : 50. In tuberculosis the agglutination reaction has no value as a diagnostic procedure. Koch recommended the agglutination test for the estimation of the degree of immunity conferred by tuberculin treatment. As pointed out elsewhere, agglutinins have apparently no antimicrobic influence, but, as with typhoid vaccination, may indicate the degree of reaction and the presence of other antibodies. Many strains of tubercle bacilli are almost non-agglutinable. The preparation of a homogeneous emulsion is not easily made, and the results are likely to be confusing and contradictory. In plague the agglutination reaction becomes quite marked about the ninth day of the disease — too late, however, to be of much practical value in diagnosis. It is occasionally useful, however, for deciding whether a patient in the convalescent stage has really suffered from the disease. making the diagnosis. In pneumonia the reaction is of value in rapidly differentiating pneumococci and as an aid in specific serum therapy (see page 308), and it may also be of aid in making the diagnosis of infection with Bacillus enteritidis and Bacillus botulinus. described by Kolmer1; Nakano,2 Kissmeyer,3 and Zinsser and Hopkins4 have also described the agglutination of culture pallidum by immune serum. Kolmer, Broad well and Matsunami5 found that equal parts of normal human serum and pallidum culture furnished by Zinsser, may result in partial agglutination, whereas with sera of syphilitics in the later stages, agglutination in dilutions of 1 : 5 and higher occurred with about 84 per cent, of sera, but that further studies are necessary to establish the practical value of agglutination in the diagnosis of syphilis. In pertussis agglutination tests have been found of some value in clinical diagnosis by Wollstein,6 Frankel,7 Seiffert,8 and Arnheim; Bordet9 finds it of value only when the microorganism is freshly isolated from human sputum and grown on rich blood medium . According to Povitsky 10 and Worth11 a dilution of serum not less than 1 : 200 is necessary for a practical positive diagnosis of pertussis, as normal human serum may agglutinate in dilutions up to 1 : 100. In veterinary practice agglutination reactions are of value in the diagnosis of glanders, infected horses reacting in some instances to dilutions as high as 1:2000. For diagnostic purposes the agglutination test in glanders must be in dilutions higher than 1:800. A positive reaction in dilutions of 1:1000 is regarded as suggestive, and is controlled by a complement-fixation test; agglutination in dilutions of 1 : 1500 practically always indicates an infection. The complement-fixation test, however, is a better diagnostic reaction. 2. Agglutination reactions are also of value as an aid to the identification of a microorganism that has been cultivated from a patient. For this purpose we must have on hand various standard immune serums. For example, if a bacillus resembling the typhoid bacillus is isolated from the feces of a patient, the diagnosis may be aided by a positive agglutination reaction with typhoid immune serum. The " group agglutinins" constitute a source of difficulty in making the differentiation among the numerous members of a group of microorganisms, but if a highly potent agglutinating serum is used and the test is carried to the point of determining the highest dilution that will agglutinate the bacteria, it will in most cases be possible to differentiate the variously allied microorganisms by this test. In conducting these reactions it is best to use a macroscopic method, and the agglutinating serum used must have been previously titrated against an easily agglutinable and known strain of the microorganism in question In this connection it is well to remember that freshly isolated cultures of a microorganism may be not at all or but very slightly agglutinable. Thus colonies of typhoid bacilli found in feces or in an abscess may, if picked from a plate, resist agglutination until subcultured several times in artificial media. The agglutination test has great value as a mode of differentiating among the members of the typhoid-colon group of bacilli. In the diagnosis of cholera, suspicious bacilli isolated from the feces may be tested with a known cholera immune serum, and the bacteriologic diagnosis thus be greatly facilitated. The test also has some value in making a biologic differentiation between meningococci and gonococci, and also between other groups of bacteria. 3. Agglutination tests are of value in determining whether, in a case in which more than one microorganism has been cultivated, the condition at hand is a single or a mixed infection. The absorption agglutinin test is made with the patient's serum, and the cultures are isolated from the patient. 4. 'Agglutination tests are also of value for measuring the immunizing response that a patient is making to his infection or to artificial immunization. Thus the test is of some value in determining the response to inoculation with typhoid vaccine, although it is probable that the agglutinin itself does not possess true antimicrobic properties. THE AGGLUTINATION REACTION The value of the agglutination test in the diagnosis of disease is limited chiefly to typhoid and paratyphoid fevers; and, in a less degree, to cerebrospinal meningitis and bacillary dysentery. It is especially useful as a practical test in the diagnosis of obscure and atypical cases of typhoid fever and also in the diagnosis of " typhoid carriers." Two methods may be employed: 1. The microscopic method which is generally employed where the Gruber-Widal reaction for typhoid fever has been employed, as the reaction is quickly done and requires but a small amount of blood. This test is usually performed with serum separated from the clot and in various dilutions (wet method) . The test may also be performed with dried blood (dry method), the agglutinins being preserved and redissolved with a diluent. The technic of the latter method is very simple. The blood is easily collected and may be sent for long distances, and for these reasons the method has been adopted by many boards of health. 2. The macroscopic method is that generally preferred if sufficient blood is on hand, and is the method of choice in scientific research. Absorption tests must be performed with the macroscopic technic. Requisites for Conducting Agglutination Reactions. — (a) Bacterial Emulsion. — This may be prepared by growing the microorganism in broth. Solid media may be used, and the culture washed off with sterile salt solution and emulsified. (1) The bacterial emulsion should be prepared of young cultures, should be homogeneous and free from clumps, and of such density as to furnish a sufficient number of microorganisms to give the reaction (Fig. 81). (2) For the ordinary microscopic Widal test, eighteen to twentyfour hour bouillon cultures of Bacillus typhosus, Bacillus coli, and Bacillus paratyphosus yield uniform and satisfactory results. An old laboratory culture — one that is known to be agglutinable — should be used. Broth cultures should be cultivated at a temperature lower than body heat, in order that long motile forms may be secured. During the summer and early autumn months the culture can be grown at room temperature ; during the winter, on top of the incubator. When these tests are done routinely, it is good practice to subculture in broth every day in order that a satisfactory culture may always be on hand. When performed at irregular intervals, a broth culture can be prepared from a stock agar culture and the test performed twentyfour hours later. in a diluent, such as normal salt solution or broth. This may be performed by placing the diluent in a test-tube and rubbing the loop over the glass just at the margin of the fluid, the bacteria being gradually emulsified and floated into the diluent. When larger quantities of emulsion are desired, as for making the macroscopic test, 5 c.c. of diluent may be poured upon the culture and the growth washed off with the aid of the platinum loop. The emulsion is gently shaken and removed to a second tube, when unresolved bacterial clumps will sink to the bottom. In other cases the emulsion may be centrifuged for a short time or filtered through sterile filter-paper. Sufficient salt solution is added to REACTION. X 430. This shows a satisfactory culture of the proper density and free of clumps of bacilli. (Twenty-four hour culture of Bacillus typhosus grown at room temperature.) The culture is rather too dense and shows considerable spontaneous or false agglutination of the bacilli. (Twentyfour hour culture of Bacillus typhosus grown at 37° C.) The bacillus (B. typhosus, B. paratyphosus, etc.) is grown for twentyfour hours at 37° C. iri ordinary veal peptone bouillon in large Erlenmeyer flasks partly filled (1 liter of bouillon in a one and a half liter flask). The culture used should be one which has been subcultivated daily in bouillon for one or two weeks (or longer). This continued subcultivation has the effect of increasing its agglutinability and diminishing any tendency to spontaneous agglutination. At the end of twenty to twenty-four hours' growth at 37° C. the flasks are well shaken, arid to each is added 0.1 per cent. (1 c.c. per liter) of commercial (40 per cent.) formalin. They are again shaken and placed in a cold chamber in the dark at about 2° C. in the cold chamber. After three or four days they will be found to be absolutely sterilized. Should it happen that the bacterial suspension is not entirely homogeneous it may be shaken for some hours in a mechanical shaker, or may finally be filtered through sterile cotton-wool. (4) To emulsify a culture of the plague bacillus or any other microorganism that displays a strong tendency to undergo "spontaneous" agglutination, distilled water or 1 : 1000 salt solution should be used. (5) In the case of a culture of tubercle bacillus, the growth can be resolved into its elements by prolonged trituration in normal salt solution, and any residue or unresolved clumps removed by centrifugalization. A less laborious and dangerous method is to use the tubercle powder of Koch, which is obtained by reducing dried tubercle cultures to a fine powder by machinery. The powder may be made up into a suitable suspension by rubbing it in a mortar with normal salt solution. (6) When it is necessary to work with highly dangerous microorganisms, or to operate from day to day with the same bacterial suspension, one may employ suspensions that have been heated for one hour to 60° C., or suspensions in salt solution to which 1 per cent, formalin has been added. These will keep well in the refrigerator, but the sediment of dead bacteria must be well shaken before it is used. (2) For the microscopic "dry method/' blood is secured by pricking the finger or lobe of the ear and collecting a few drops of blood upon aluminum foil, on a clean glass slide, or on partially glazed paper. The blood must not be heated to hasten drying, or agglutinins may be destroyed. Smears on aluminum foil and on glass slides are to be preferred to those on paper, as the blood can be moistened and portions removed without the likelihood of transferring extraneous material, such as paper fiber. While there are certain objections to this method to be pointed out later, yet practical experience has demonstrated its value, as the serum does not readily deteriorate or become contaminated with bacteria, and the ease with which blood may be collected and mailed recommends the process for board of health laboratories. (3) For the macroscopic test larger amounts of serum are needed. Sufficient blood is easily obtained by pricking the finger deeply and collecting several cubic centimeters in a small test-tube. (4) Because normal agglutinins may be active in dilutions as high as 1 : 30, for diagnostic tests in typhoid fever the serum should not be diluted lower than 1 : 40. For routine work dilutions of 1 : 50 and 1 : 100 are well adapted for the microscopic test. Dilutions of 1:40 and 1:80 are readily made with the white corpuscle pipet and are equally useful. made and the work completed. (c) Early in typhoid fever the bacillus may be present in the blood, and consequently due care should be exercised in handling it, in diluting the serum, and in the disposal of the clot. WIDAL REACTION IN TYPHOID FEVER (1) Dilute the patient's serum by placing one drop from a capillary pipet in a small watch-glass and adding 19 drops of normal salt solution. This gives a dilution of 1 : 20. Mix thoroughly. (2) With a 3 or 4 mm. platinum loop place a drop on a clean coverglass that is sufficiently thin to permit the use of an oil-immersion lens. The loop is better than a capillary pipet because the drop it gives is smaller, and when it is later diluted with an equal quantity of bacterial emulsion, it is not too large and is easily manipulated. (3) With the same sterilized platinum loop add one loopful of a twenty-four-hour broth culture of Bacillus typhosus to the drop of diluted serum on the cover-glass. Mix gently and without spreading the drop. This gives a final dilution of 1 : 40. (4) Edge a hanging-drop slide with vaselin, and invert the coverglass slide over the hollow portion in such a manner that the drop will be suspended in its center. Care must be exercised not to spread the drop, for if this occurs and the fluid flows around the margins of the chamber a new preparation must be made. Inspect the slide, and add vaselin, if necessary, until it is sealed tightly. By means of a grease pencil label the slide with the name of the patient, the dilution, and the time when the preparation was made. (5) Place 2 to 5 drops of serum dilution 1 : 20 in a second watchglass, and add an equal quantity of normal salt solution. Mix well. This gives a dilution of 1 : 40. (6) Prepare a second slide by mixing a loopful of this dilution with an equal sized loopful of culture. Mix gently. This gives a final dilution of 1 : 80. Mark the slide with the name, dilution, and the time. (7) Prepare a third slide by placing a loopful of culture on a coverglass and invert over a concave slide to which vaselin has been applied in the usual manner. This is the culture control. Label the slide. (6) Examine the 1 : 40 and 1 : 80 dilution preparations: a positive reaction is indicated by loss of motility and definite clumping (Fig. 83). A few free motile bacilli may be seen, or a clump may be seen to move, owing to the efforts of the bacilli to break away. A doubtful reaction is indicated by a partial loss of motility and a few indefinite clumps. A negative reaction is indicated when there is no loss in motility or no clumping, or when the reactions resemble the control to which no serum has been added. In reporting upon agglutination tests always state the time at which the test was made and the dilution used. A 1 : 20 and a 1 : 40 dilution may be prepared and examined at the end of half an hour. Prompt agglutination is found practically only in typhoid fever. Dilutions may be conveniently prepared by drawing the serum up to the mark 0.5 in the white corpuscle pipet, and the distilled water up to the mark 11. Mix well. of the microorganism to be tested give a dilution of 1 : 40. One loopful of the 1 : 20 diluted serum and three loopful s of the culture give a dilution of 1 : 80. Having mixed the diluted serum and the bacterial suspension on a cover-glass, prepare the cultures on the vaselined concave slides in the usual manner. (2) Moisten the dried blood which has been collected on aluminum foil, glass slide, or paper with a loopful of normal salt solution. (A second and smaller loop may be used for this purpose.) Gently rub up the dried blood and transfer a sufficient amount to the drop of culture on the cover-glass until, when thoroughly mixed, it presents a delicate orange tint (Fig. 84). Avoid transferring too much debris with the solution of blood, especially if the blood has been collected on paper. It is good practice to mix the culture and solution of blood with the cover-glass held over a white surface, in order that the color may readily be observed. FIG. 84. — MICROSCOPIC AGGLUTINATION TEST WITH DRIED BLOOD. Shows the proper color of the suspended drop of typhoid culture when the solution of dried blood has been added. The tinge should be light orange or yellow, and a shade lighter than ordinary vaselin used in sealing the preparation. (5) Examine at the end of an hour with the y§ or oil-immersion lens. If minute fragments of fiber, etc., have been transferred, due allowance for false agglutination for these should be made. Otherwise the readings are made in exactly the same manner as in the "wet" method. (6) Accurate dilutions are not possible with this technic. Satisfactory results are dependent largely upon the color; a faint orange tint of the suspension is desirable, and probably represents a dilution of about 1 : 40. This method, however, is very simple, and when carefully performed, yields results in the practical serum diagnosis of typhoid fever almost as satisfactory as the serum-dilution method. It is possible, however, to work with known approximate dilutions by the dried blood method if a good chemical balance is available. Blood must be collected on aluminum foil or glass, and is then scraped off and weighed. To each five milligrams of dried blood 0.5 c.c. of salt solution is added which equals a dilution of 1 : 25 of whole blood or 1 : 100 of dried blood (Wesbrook). After permitting the mixture to stand for half an hour it is centrifuged for a short time. To one drop of the dilution thus obtained one drop of culture is added, which gives a final dilution of about 1 : 50. At the end of an hour it is examined. Higher dilutions can be prepared from this stock dilution at the will of the operator. MACROSCOPIC AGGLUTINATION TEST This is frequently the method of choice in conducting agglutination tests, especially in investigation and research work, where a high degree of accuracy is desirable. All dilutions and measurements are to be made with accurate volumetric pipets. rack and add 1 c.c. of normal salt solution to each. 2. Dilute the serum 1 : 5 in the first tube, as follows: 0.2 c.c. serum plus 0.8 c.c. salt solution. This now gives in this tube 2 c.c. of a dilution of 1 : 10. Mix well with the pipet. 3. Place 1 c.c. of the serum from tube 1 into tube 2. Mix well, and place 1 c.c. of the mixture from tube 2 into tube 3, and so on. When the sixth tube has been reached, discard 1 c.c., as no serum is to be added to the seventh tube, which is the culture control; i. e., it will contain salt solution plus bacterial emulsion. serum dilution in each. Tube 1 now contains a serum in a dilution of 1:20, acting on the bacteria; tube 2, one of 1:40; tube 3, one of 1:80; tube 4, one of 1:160; tube 5, one of 1:320; tube 5, one of 1 : 640. Tube 7, as just stated, contains the bacterial emulsion in salt solution and is the culture control, marked on the tubes. The tubes are then shaken gently, stoppered with cotton plugs, and placed in the incubator at 37° C. or in a water-bath at 55° C. for two hours. The tubes are then allowed to remain at room temperature for six hours, or in the refrigerator for twenty-four hours, after which readings are made. Note absence of agglutination in dilution 1 : 50; agglutination beginning in 1 : 100, and fairly well marked to 1:4000 inclusive. Note uniform cloudiness of control. This reaction was set up with a typhoid immune serum over six months of age; the drawing was made after the tubes had been incubated two hours and placed in a refrigerator overnight. broken up by gentle agitation. A positive reaction shows masses and clumps of bacteria adhering to the sides and bottom of the tube, which are broken up with some difficulty (Fig. 85). The supernatant fluid should be clear. As dilutions become higher and the amount of contained agglutinin correspondingly less, agglutination becomes less and less complete. There is less sediment, and the turbidity of the supernatant fluid is greater, until the negative tube closely resembles the cul- In this manner the smallest deposits are easily seen and compared with the control. ture control. A microscopic examination of a deposit will show that the bacilli point in all directions, whereas in a deposit of unagglutinated bacilli they lie horizontally side by side. When agglutinoids are present, agglutination is absent or incomplete in the lower dilutions of serum, and complete in the tubes containing the higher dilutions. This is called pro-agglutination (Fig. 86). the agglutinoscope (Fig. 87). The tubes are placed in a rack having numbered holes, and are viewed from beneath with the aid of a mirror. In this way one looks upward through the column of fluid, and secures a combined view of sediment and turbidity, and when examined with the culture control, fine and accurate readings may be made. 1. Make dilutions of serum as described. 2. Emulsify thoroughly a loopful (2 mg.) of culture from an eighteento twenty-four-hours-old agar culture in the first test-tube, repeating the process in the second tube, and so on through the series. In this method the serum dilutions are not doubled ; thus in the foregoing series the dilutions would be 1 : 10, 1 : 20, 1 : 40, 1 : 80, 1 : 160, 1 : 320. and a dilution tube. With the proper dropping pipet measure out into the dilution tube 54 drops of normal saline solution, 0.85 per cent, sodium chlorid, in distilled water (where the water supply is pure, tap-water can be used instead of saline solution) by means of gentle pressure on the teat. followed by successive quantities of ether, and get rid of the ether. Take up the serum to be tested into the dried pipet. Measure out 6 drops of the serum into the dilution tube already containing the 54 drops of saline solution, thus obtaining a dilution of 1 in 10. Mix thoroughly. At each stage of the procedure the pipet is carefully washed and dried out with successive quantities of absolute alcohol followed by successive quantities of ether. In Tube 1 of each row the serum acts in a dilution of 1 in 25. In Tube 2 of each row the serum acts in a dilution of 1 in 50. In Tube 3 of each row the serum acts in a dilution of 1 in 125. In Tube 4 of each row the serum acts in a dilution of 1 in 250. dilutions are followed out in a similar manner. Thus, for example, 57 drops of normal saline solution plus 3 drops of a 1 in 10 serum dilution will give a serum dilution of 1 in 200, and, using the same quantities as before, one has the serum acting in dilutions of 1 in 500, 1 in 1000, 1 in 2500, and 1 in 5000. And similarly for higher dilutions. The tubes are examined after two hours at 50° to 55° C., followed by fifteen minutes' standing at room temperature. The reading is taken by comparing each tube in succession with the control tube, and is preferably made by means of artificial light against a black background. If daylight is used, the tubes inspected should be partly shadowed by passing a finger up and down behind them. In non-inoculated persons who have not had typhoid (or paratyphoid) fever, agglutination in a dilution of 1 in 25 justifies a strong suspicion of typhoid (or paratyphoid) infection. But the test must be applied again in the course of a few days to ascertain whether there is any change in the titer of agglutination. Marked agglutination in a dilution of 1 in 50 or more is (nearly always) diagnostic of active typhoid (or paratyphoid) infection. in the titer of his serum on repeated examination at short intervals. Inoculated persons if quite recently inoculated will usually show a high titer of specific agglutination. A rapid rise in titer sets in within two to four days of inoculation. This is followed by a fall at first rapid, but subsequently becoming very slow, so that a relatively high titer is maintained for a long period (even for years) . During this period examinations made at intervals of a few days give practically identical readings. It follows that in the case of inoculated persons the diagnosis of active typhoid (or paratyphoid) infection will require two or more successive examinations of the serum. (a) If the individual is suffering from active typhoid infection his titer of typhoid agglutination will exhibit the usual rise and subsequent regular fall seen in non-inoculated subjects, but starting from and returning toward the higher base line of inoculated persons. the former level. 3. A marked rise may occur synchronous with the rise in paratyphoid agglutination titer, and subsequently followed by the usual fall toward the former level. Meanwhile the titer of paratyphoid agglutination runs the normal course of rapid rise to a maximum (usually exceeding the maximum typhoid titer), followed by a fall, at first rapid and then slower, as already described for typhoid subjects, and falling below the persistent base line of typhoid agglutination of inoculated persons. In the case of mixed infections, whether in inoculated or noninoculated persons, the agglutinin curves for the different infecting organisms are usually not synchronous, and they pursue their ordinary course independently of each other. Technic of Conglutination Test with Bacteria. — Fresh bovine serum is heated to 56° C. for one-half hour and tested for agglutinin for the bacteria under study. If agglutinin is present it is removed by adding to each 5 c.c. of serum about 10 loopsful of the corresponding bacteria, mixing well, and removing the clumps by thorough centrifuging and filtration through paper after standing at room temperature for several hours. It may be necessary to repeat this step once or twice more. Dilutions of the patient's serum in amounts of 1 c.c. are made in small clean test-tubes, as in the macroscopic agglutination test. To each tube add 0.1 c.c. of bovine serum ("conglutinin") ; 0.1 c.c. of fresh guinea-pig serum (complement) and 0.1 c.c. of the emulsion of the bacteria of sufficient density to give well-marked emulsions in the test-tubes. Controls of bovine serum, complement serum, and patient's serum should be included; also a culture control prepared with normal salt solution. After gentle mixing and standing at room temperature for twenty-four hours the results are read; positive results are indicated by complete clearing of the tube with the micro-organisms in flakes or granules, either clinging to the sides of the tube as granular material or at the bottom as flaky granular sediment. The Agglutination Test in the Differentiation of Pneumococci.— The investigations of Neufeld and Handel, and particularly of Cole, Dochez, and their associates in the Rockefeller Institute, have resulted in the grouping of pneumoccoci into four groups on the basis of agglutination and protective tests. Group III is composed of pneumococci belonging to the type of pneumococcus mucosus, and an efficient antiserum has not yet been produced; Group IV is composed of all pneumococci not falling into the first three groups. Trie agglutination test is conducted for the purpose of determining the presence of types I or II; in case either is present and it is decided to administer an immune serum, the serum corresponding to the type of infection must be given. Either a macroscopic or microscopic technic may be employed; as it is advisable to learn the results as quickly as possible, the latter saves time, although it is generally considered as being less accurate than the former. salt solution, and 1 c.c. injected into the peritoneal cavity of a mouse. 2. If sputum is not obtainable, a culture may be secured by puncture of the lung after anesthetizing the skin with sterile eucain solution. With a sterile syringe carrying 2 c.c. of warm sterile salt solution and medium-sized needle a puncture is made into the consolidated area and exudate secured which is injected into the peritoneal cavity of a mouse. 3. Four to eight hours later the mouse is killed with ether and the peritoneum washed out with 5 to 10 c.c. of normal salt solution. This emulsion is briefly centrifuged to throw down cells and the supernatant fluid transferred to a second centrifuge tube followed by rapid and thorough centrifuging to throw down the pneumococci. The sediment of cocci is then suspended in sufficient normal salt solution to give an even emulsion of proper density. The supernatant fluid maj^ be used in the precipitin test of Blake as described on page 321. 4. Macroscopic tests are prepared by mixing in small clear test-tubes equal parts (0.5 c.c.) of bacterial suspension and antipneumococcus sera of types I and II undiluted and diluted 1 : 5 with salt solution. The final dilutions are 1 : 2 and 1 : 10. These mixtures are incubated at 37° C. for two hours, when the results are read. A control of bacterial emulsion and salt solution should be included, and it is advisable to test out the immune sera from time to time with pure cultures of the homologous strains. 5. Microscopic tests are conducted by mixing on cover-slides platinum loopsful of bacterial emulsion and undiluted and diluted immune sera. These slides are then suspended as hanging-drop preparations and the results read after one-half to an hour. A control should always be included. The practical importance of partial agglutinins is recognized in the diagnosis of mixed infections. Thus the serum of a patient may agglutinate typhoid as well as paratyphoid bacilli in dilutions up to 1 : 100. This may indicate one of three possibilities: 1. The patient may be infected with typhoid, but has formed an exceptionally large quantity of group agglutinins for paratyphoid bacilli. Saturation of this serum with typhoid bacilli will remove all the typhoid and a portion, if not all, of the group agglutinins. Saturation with paratyphoid bacilli will remove the group agglutinins, but not the main or typhoid agglutinin. 2. The patient may be infected with paratyphoid bacilli, but has formed, at the same time, many partial agglutinins for typhoid bacilli. Saturation of the serum with paratyphoid bacilli will remove all the paratyphoid and a large portion of the typhoid agglutinin. 3. The patient may have a mixed infection of typhoid and paratyphoid, and therefore agglutinin for both may be present. Saturation of the serum with typhoid bacilli will remove the typhoid and probably a small portion of the paratyphoid agglutinin. After this reaction the serum will still show the presence of a decided quantity of paratyphoid agglutinin. 1. Four rows of test-tubes are arranged, each row being made up of four small tubes each containing 1 c.c. of serum dilutions 1 : 20, 1 : 40, 1 : 80, and 1 : 160 respectively. typhoid bacilli are emulsified. Arrange the paratyphoid culture control. 4. Mix gently and incubate for four hours. Carefully record the presence or absence of agglutination in each test-tube. Centrifuge all the tubes excepting the two controls, and transfer the supernatant fluid of each to other test-tubes arranged in the same order. 5. To each tube of the first and third rows add five loopfuls of typhoid bacilli; to each of the second and fourth rows, five loopfuls of paratyphoid bacilli. Mix well and incubate for four hours. (a) If typhoid is present, the agglutination titer in the first part of the test will be strong in the tubes of the first and second rows, and weak in those of the second and third rows. In the second part of the test the titer for typhoid will be weak or nil in the first, second, and fourth rows, whereas in the third row it will remain practically the same. (6) If paratyphoid exists, the agglutination titer in the first part of the test will be strong in the tubes of the third and fourth rows, and weak in those of the first and second rows. In the second part of the test the titer for paratyphoid will be less or nil in the fourth row, and strong or unchanged in the second row. (c) If a mixed infection exists, the agglutination titer in the first part of the test will be strong in the tubes of all four rows. In the second part of the test the titer in the first and fourth rows is much weaker or nil, and in the second and third rows it will remain the same. Technic of Acid Agglutination. — Mixtures of lactic acid and sodium lactate have been generally employed. Gillespie has prepared these from stock solutions of one-third normal sodium lactate, with a small crystal of thymol, and normal lactic acid, according to the following scheme: Young cultures of bacteria should be employed; if grown in broth, they may be prepared by rapid centrifuging and resuspension in sufficient distilled water to secure an even emulsion of such density as suitable for the macroscopic agglutination test — 0.3 c.c. of the bacterial emulsion is placed in each of a series of small and perfectly clean tubes in a rack, and 1 c.c. of the proper reaction mixture added to each tube. The tubes are then gently and briefly shaken and placed in a water-bath at about 37.5°C. for an hour or two. Michalis1 uses acetic acid and reports sharp differentiation of Bacillus typhosus by the. method of acid agglutination. AND ISOHEMOLYSINS 1. Two or three c.c. of blood are obtained from each donor from a vein at the elbow and 0.5 c.c. is placed at once in a centrifuge tube containing 5 c.c. of a 1 per cent, sodium citrate in normal salt solution. The remainder is placed in a small, dry test-tube until coagulation has occurred and the serum has separated. 3. The sodium citrate tubes are centrifuged; the supernatant fluid is pipeted off, and the cells are washed again with normal salt solution. After the final washing enough normal salt solution is added to the sediment of cells to bring the total volume up to 5 c.c. obtained. These should preferably be free from hemoglobin stain. 5. The following mixtures should be set up within twenty-four hours of the time of collecting blood, in order that native complements may not have undergone deterioration. Measurement may be made according to a drop from an ordinary 1 c.c. graduated pipet held vertically. Small sterile test-tubes (8 by 1 cm.) are to be used. hemolysis. Tube 5: Control: 1 drop of donor's red-cell emulsion -J- 4 drops of normal salt solution. This serves as a control on the toxicity of the corpuscles and isotonicity of the salt solution. Tube 6: Control: 1 drop of recipient's red-cell emulsion + 4 drops of saline solution. One cubic centimeter of salt solution is added to each tube and the tubes are gently shaken and placed in the incubator for two hours. They are to be inspected every half hour. Agglutination is recognized macroscopically by the clumping of the red blood-cells into small masses that later sink to the bottom of the tube as a small clot. Hemolysis is likewise easily detected, as corpuscles tend to become precipitated within two hours. If doubt exists, the finer grades of hemolysis may be detected after the tubes have been allowed to stand over night in an icechest, or at once by thorough centrifugalization. Pipet Method. — In cases where, for any reason, the quantities of blood previously named cannot be secured, the whole operation may be conducted with smaller amounts, using Wright's capillary pipets (Epstein and Ottenburg). This method is as follows: Blood is secured from both recipient and donor by pricking the finger of each and allowing five or six drops of blood to flow into 5 c.c. of sodium citrate solution, and collecting a good-sized Wright capsule full for securing the serum. The corpuscles are washed twice and enough normal salt solution added to make up approximately a 10 per cent, suspension. The capsules are centrifuged if necessary, filed, opened, and the serum pipeted off. The mixtures are prepared in Wright's capillary pipets (see Fig. 48) fitted with rubber nipples. The unit volume is marked off by a blue pencil on the stem about an inch from the tip. Four volumes of serum, one volume of cell emulsion, and four or five volumes of salt solution are drawn up into the pipet and then mixed gently, running them out on a watch-glass. The entire mixture is then drawn into the barrel of the pipet and the tip sealed. The pipets are carefully labeled, incubated for two hours, and examined for agglutination and hemolysis. The results are somewhat more difficult to read, but the method is of value when many donors are to be examined or when the supplies of serum and corpuscles are limited. TESTS FOR ISOHEMAGGLUTININS AND ISOHEMOLYSINS 313 technic is especially recommended for rapidity and grouping; the masking of agglutination by hemolvsis is delayed or prevented. This method of grouping should be used in conjunction with the group of Moss as given on page 286. It is necessary to have on hand a Group 2 or Group 3 blood, and the laboratory worker should know the grouping of his own blood to be used in this work. Group 2 or Group 3 serum may be preserved in a sterile condition in the refrigerator for several months without losing agglutinating properties. Group 2 and Group 3 corpuscles may be preserved for four weeks in the refrigerator by the method of Wohl,1 who adds 3 drops of blood to each cubic centimeter of a solution prepared by adding 0.5 c.c. of 40 per cent, formaldehyd solution to 500 c.c. of 0.85 per cent, sodium chlorid solution containing 2 per cent, sodium citrate. Five or 6 drops of Group 2 blood are collected in a small clean, dry test-tube or centrifuge tube, and 2 drops in another tube containing 1 c.c. of 1.5 per cent, sodium citrate in 0.9 per cent, salt solution. The serum and corpuscles of the unknown blood to be grouped are collected in the same manner. The bloods in the dry tubes are allowed to coagulate, the coagula loosened with a platinum loop, and the sera separated by centrifuging. Sera and corpuscles are now ready for the tests. Two platinum loopsful of serum are mixed with one loopful of corpuscle suspension on a cover-slide and inverted over an ordinary hangingdrop slide ringed with vaselin. Each serum is set up with each corpuscle suspension. Agglutination, if it occurs, takes place at room temperature within five minutes; the slides should be examined at once and at short intervals with a f objective of the microscope, and rouleaux formation must be differentiated from small clumps due to agglutination. PRECIPITINS CLOSELY allied to the agglutinins are antibodies known as precipitins. They act on dissolved albuminous bodies in a manner quite similar to the action of agglutinins upon formed cellular elements. For example: (1) If typhoid immune serum is added to a bouillon culture of typhoid bacilli, agglutination occurs; (2) if the culture is filtered and the immune serum is added to the clear sterile filtrate, cloudiness appears and finally a precipitate forms. The first is an example of the action of agglutinins upon the formed bacilli, and the second illustrates the action of precipitins upon the albumins of dead and dissolved bacilli. Precipitins are formed not only for bacterial albumins, but for most any soluble animal (zooprecipitin) and vegetable protein (phytoprecipitiri) as well. If the serum of a rabbit immunized with horse serum is added to horse serum, a precipitate forms, owing to the presence of a specific precipitin in the immune serum. Normal rabbit serum does not possess this power. Definition. — The precipitins are specific antibodies that develop in the serum of animals inoculated with bacteria or with solutions of animal or vegetable albumins, which possess the power of producing a precipitate in a . dear solution of the particular albumin or culture filtrate against which the animal has been immunized. Historic. — Kraus (1897) was the first to study and describe the bacterial precipitins. He observed that when the serums of animals that have been immunized against cholera, typhoid, or plague are added to a clear filtrate of the respective bouillon cultures of their bacteria, instead of to the bacteria themselves, the clear solution becomes turbid and a precipitate forms. This reaction was found to be quite specific, i. e., it occurs best with the filtrate of the homologous bacteria, and to a much less extent with closely allied species. For example, the typhoid immune serum does not produce a precipitate with a filtrate of Spirillum cholerse, and similarly a cholera immune serum does not produce a precipitate with the filtrate of Bacillus typhosus. Kraus advocated the precipitin reaction as a means of identifying and differentiating certain species of bacteria, but the test possesses no advantage for these purposes over agglutination reactions and is not generally employed. Tchistovitch was the first to call attention to the non-bacterial precipitins. This observer found that the serum of rabbits inoculated with eel serum, when mixed with a small quantity of the eel serum, caused a precipitate to form. About the same time (1899) Bordet found that the serum of rabbits inoculated with the serum of chickens, when mixed with the chicken serum, gave a specific precipitate. A little later Bordet produced an anti-milk immune serum (lactoserum) by inoculating rabbits intraperitoneally with milk partially sterilized by heating to 65° C. When this immune serum was mixed with the homologous milk, small particles appeared, which gradually formed larger flak.es and sank to the bottom of the fluid. It was found that the lactoserums were specific — i. e., cow lactoserum would precipitate only cow casein, human serum only human casein, etc. Wladimiroff was the first to use the bacterial precipitin reaction as a practical diagnostic test. He showed that the serum of a horse suffering from glanders would, when added to a clear filtrate of a culture of Bacillus mallei, produce a precipitate. The technic of these reactions is, however, more difficult than with the agglutination tests, and as the reactions are usually not more delicate or more advantageous than the latter, they are seldom employed. Following Wladimiroff, Uhlenhuth and Wassermann made a very important practical demonstration of the value of serum precipitins in differentiating the blood and secretions of man and animals. For example, the serum of rabbits immunized with various bloods would react with solutions of old and dried specimens of their respective bloods, and although " group" precipitins were found present in the tests with the blood of closely allied species, yet the value of the reaction was not impaired to any extent when a proper technic, with correct dilutions, was employed. These discoveries were found to possess considerable value in forensic medicine, particularly in the recognition of the source of blood-stains. Nuttall, in a thorough and painstaking research with the blood from 500 animals, was able to study the "blood relationship" of various animals as based upon group precipitins. For example, the serum of a rabbit immunized with human blood will react best with human serum, then with the serums of the higher apes, and finally with the lower orders Nomenclature. — The antibody in an immune serum responsible for the phenomenon of precipitation is called precipitin; the substance or antigen responsible for the production of this antibody is known as the precipitinogen; the precipitate is the end-product of the reaction between precipitinogen and precipitin. Just as toxoids and agglutinoids may be formed, so precipitin may be modified to precipitoid. Although, since bacterial precipitins are produced by the protein constituents of bacteria, the custom of differentiating between bacterial and protein precipitins is superfluous, nevertheless, when the meaning is clearly understood, the term bacterial precipitin is convenient and may be employed. The precipitins derive their names from their precipitinogens, as, for example, a precipitin produced by injecting rabbits with ox serum is designated anti-ox precipitin. Normal Precipitins. — Although agglutinins may be found in normal serum, it is decidedly uncommon to find normal precipitins. Extracts of organs have been known to contain normal precipitins for certain albumins, although at the same time they were absent from the serum of the animal. In this case the active bodies exist in the cells as "sessile receptors," and by the process cf extraction they are brought into solution. During immunization these same receptors are stimulated to overproduction and are thrown into the circulation as free precipitin receptors. Immune precipitins are antibodies produced by immunization with a foreign albumin, either during the course of a bacterial infection or as the result of artificial inoculation. Structure and Properties of Precipitins. — According to the side-chain theory, precipitins are antibodies or receptors of the second order, composed of a combining arm or haptophore group for the precipitinogen, and a zymophore or precipitinophore group that precipitates the antigen. Their structure is, therefore, seen to be quite similar to that of agglutinin, the difference being largely due to the different functions of the zymophore group. The properties of precipitins are quite similar to those of agglutinins. They are fairly resistant bodies, resist the effect of drying for prolonged periods, but are gradually destroyed by heating to 60° to 70° C. When inactivated by exposure or heat, they cannot be reactivated by the addition of fresh normal serum, and therefore they bear no relation to the to secure the reaction. The haptophore or combining arm is quite stable; the precipitophore group is more labile, and is affected by heat, and when this less resistant arm is lost, the receptor is called a precipitoid. Like agglutinoids, the precipitoids are of practical interest from the fact that their haptophore arm will not only combine with precipitinogen, but displays a greater activity in this direction than the whole receptor or precipitin itself, and when union between precipitinogen and precipitoid has occurred, precipitation does not result. Hence in low dilutions of a precipitin serum the phenomenon of precipitation is slight or altogether absent, whereas in higher dilutions the reaction becomes evident. Group precipitins are not so prominent as group agglutinins, yet they are formed to a certain degree and are of much practical importance in attempting to differentiate bacteria and serums by the precipitation method. Although precipitins are highly specific, the principle of serum dilution, as emphasized under Agglutination, must be closely observed in order to dilute the group precipitins to such small amounts as to prevent them from interfering with the chief precipitin. This principle is of particular importance in differentiating the bloods of various animals, and especially in medicolegal cases, where the precipitin reactions are employed for the diagnosis of blood-stains. Formation of Precipitins. — Immune serums for diagnostic purposes are produced by injecting the precipitinogenous fluid into the veins, peritoneal cavity, or subcutaneous tissues of animals, usually rabbits. The power of forming precipitins is probably disseminated among the organs and general body tissues. Kraus and Levaditi assign the leukocytes as the chief source of precipitin formation. As in the case of agglutinin formation, not all animals possess equally the power of forming a precipitin for a given albumin. While this point is of general interest with the bacterioprecipitins, it becomes of particular importance in relation to serum precipitins. For example, an animal will not form a precipitin active against its own serum. If formed, it would be an autoprecipitin, or isoprecipitin, and, as a rule, animals do not form antibodies for their own tissue constituents. Furthermore, animals are unlikely to form precipitins for the proteins of other members of the same species, or if precipitins are produced, they are usually the result of prolonged immunization of a number of animals. Precipitin formation is also slight for the proteins of other animals that are closely related either zoologically or biologically. For example, attempts at immunization of a guinea-pig with the serum of a rabbit, a pigeon with that of a hen, or a monkey with human serum, are procedures that do not usually yield good precipitating serums. Attempts have been made to produce antiprecipitin by effecting immunization with immune precipitating serums. Such attempts have been reported as partially successful with serum and milk, but not with bacterial precipitins. Antiprecipitins possess no practical value. Mechanism of Precipitation. — Of the various theories advanced to explain the phenomenon of precipitation, none has received so much support experimentally as that advanced by Bordet in explanation of agglutination. Colloids may be precipitated by salts, and probably the salts so alter the electric state of colloidal particles that their surface tension is decreased, and, as a result of this. change, neighboring particles coalesce in such quantities as to produce a visible precipitate. Salts are likewise necessary for serum precipitation, and there is a close analogy between serum and colloidal precipitation. The origin of the precipitate formed during the reaction is of interest. When a very potent immune serum is employed, the precipitinogen is so highly diluted that it no longer gives any of the chemical reactions for proteins, but when the precipitating serum is added, it may yield, nevertheless, a heavy precipitate. The precipitate can, therefore, hardly be regarded as due to the slight trace of albumin in the precipitinogen, and, furthermore, if the precipitating serum is diluted, the precipitate becomes smaller and smaller, and, if the dilution is increased, it finally disappears altogether. For this reason the precipitate is generally considered as originating in the immune serum. Specificity of Precipitins. — Precipitins react but feebly on closely related albumins of the same species, but are specific against those of unrelated species. In other words, the precipitation test merely determines the animal species from which the proteid originates, but cannot demonstrate positively whether it comes from the blood, the semen, milk, or other albuminous body. For medicolegal purposes, therefore, a diagnosis of "human blood-stain" cannot be made without chemical evidence to prove that the stain actually consists of blood. An immune serum prepared by the injection of the serum of a certain animal gives a precipitate also with the juices of the various organs of that animal. The only exception to this rule is the protein of the crystalline lens of the eye, which gives no precipitate with the antiblood immune serum. The same albumin exists in the crystalline lenses of all R6LE OF PRECIPITINS IN IMMUNITY 319 animals, — from fishes to man, — and a serum produced by immunization with lens substance will react with the protein derived from the lens of any animal, but with no other animal proteid. This theory of species specificity may, however, be carried a little further, for by 'carefully freeing the organs from all blood and then using organic extracts for inoculation, it is possible to produce serums that will yield a precipitate best with the particular variety of organic extract (liver, kidney, etc.), and a weak or no precipitate with extracts of other organs of the same animal. Besides this animal specificity, precipitin reactions also demonstrate the "constitutional specificity" of proteins. If, instead of using a pure animal or plant albumin for immunization, variously altered albumins are used (heated albumins, acid albumin, formaldehyd albumin, and the like), the organism reacts by producing antibodies of a characteristic nature, differing from those developed after inoculation with pure albumin. For example, if a rabbit is immunized with normal horse serum, the resulting immune serum will produce a precipitate when added to pure horse serum, but not when added to horse serum that has been heated. On the other hand, if a rabbit is inoculated with horse serum that has been diluted and boiled for a short time, the resulting immune serum will react not only with normal horse serum, but also with heated serum and a group of its decomposition products with which the normal immune serum ordinarily never produces a precipitate. This observation is of practical importance in detecting meat substitution by precipitin reactions. In order to render the detection difficult, the meat is commonly boiled ; with the aid of precipitins produced by immunization with heated proteins, this fraud is more easily detected than if a normal immune .serum were used. Obermeyer and Pick have demonstrated that while animal specificity is not destroyed when the albumins are modified by heat, tryptic digestion, or oxidation, their specificity is lost when an iodin, nitro- or diazo-group is inserted into the protein molecule. Immunization with such transformed proteins, e. g., xanthoprotein, can produce a precipitating serum that will react with every xanthoprotein, even that of different animals. These investigators conclude that species specificity is probably dependent upon a certain aromatic group of the protein molecule. Role of Precipitins in Immunity. — Precipitins are probably not truly protective antibodies, like antitoxin and the lysins, but they are quite similar to the agglutinins in being secondary products of cellular activ- ity, and they are of value chiefly as indicators of this general antibody formation. They may, however, be concerned in preparing their antigens for destruction and solution, just as opsonins prepare cells for phagocytosis, but precipitins themselves possess no appreciable curative or protective virtues, and are of value chiefly in diagnostic procedures. Bacterial precipitins have no clinical diagnostic value. Their reactions have no advantage over the agglutination test, they are more difficult of execution than the latter, the sources of error are greater. In scientific research they may be of value in differentiating microorganisms from closely allied species, but even here agglutination reactions serve the purpose equally well and are less difficult of execution. Occasionally bacterial precipitins are of service in demonstrating the presence of soluble bacterial substances within exudates or organic fluids. For example, Vincent and Bellot recommend the reaction as being of considerable value in the diagnosis of cerebrospinal meningitis. The cerebrospinal fluid is centrifugalized until it is clear; 2 c.c. of this clear fluid is then placed in one tube and 4 c.c. into another. One-tenth cubic centimeter of a standard antimeningococcic serum is added to each tube. The tubes are kept for from twelve to fifteen hours at 37° C. In the presence of cerebrospinal meningitis a precipitate forms. If the fluid is normal or if it was derived from some other form of meningitis, no cloudiness results. This reaction is said to occur within the first twenty-four hours of the illness and to persist until the twelfth to the twentieth day. Similar reactions have been advocated in the diagnosis of other infections, particularly syphilis. Fornet believed that the presence of typhoid antigen (precipitinogen) ought to be capable of demonstration in the blood-serum of typhoid fever patients long before antibodies themselves are in evidence. One cubic centimeter of potent immune serum in concentrated and diluted form (1:5 and 1 : 10 with normal salt solution) is placed into small test-tubes, and an equal amount of the serum for examination, also in concentrated and similar dilutions, is carefully floated on top of the immune serum. Control tests with normal and immune serum and normal with unknown serum are made. The mixtures are allowed to stand undisturbed at room temperature for two hours, and if the reaction is positive, a whitish ring makes its appearance at the point of contact of the two serums, the controls remaining negative. According to Citron, this ring test is also evident in the presence of scarlet fever, measles, and syphilis. Precipitin Reaction in Pneumonia. — Dochez and Avery have demonstrated the presence of a soluble pneumococcus substance specific for the type strain in the blood and urine of persons suffereng with pneumonia, and found a precipitin reaction of value in the diagnosis of the type of pneumococcus causing the infection. Equal parts (0.5 to 1.0 c.c.) of fresh clear serum or urine are mixed in small clean test-tubes with antipneumococcus sera I and II; a distinct cloud which becomes more definite after standing an hour develops with the immune serum corresponding to the type strain of infection if due to types I or II. If the reactions are indefinite they should be repeated with the immune sera diluted 1 : 2 with normal salt solution. Blake has found a precipitable substance in the peritoneal exudate of mice used in the differentiation of pneumococci by the agglutination method (see page 308). After securing the exudate it is thoroughly centrifuged, and equal parts (0.5 c.c.) of the clear supernatant fluid and antipneumococcus sera belonging to types I and II mixed in small clean test-tubes. The development of a ring or distinct cloud indicates the type of infection if belonging to types I or II, and the method saves time as compared with the agglutination test. Fornet Ring Test. — Owing to the wonderful activity that has marked the research work of syphilis several precipitation tests for diagnostic purposes were devised. These have all been overshadowed and forsaken for the Wassermann complement-fixation test. Fornet applied his ring test, using the serum of patients with manifest luetic symptoms as the precipitinogen, and the serum of paretics as the precipitating or immune serum. Klausner advocated a simple test consisting of mixing in a small test-tube 0.2 c.c. of fresh, active, and absolutely clear serum, with 0.6 c.c. of distilled water. This serum and the control mixtures are allowed to stand at room temperature for from seven to fifteen hours, when a thick, flocculent precipitate of fibrin globulin will appear at the bottom of the tube. serums are capable of producing flocculent precipitates from solutions of lecithin and similar salts. Two-tenths of a cubic centimeter of a 1 per cent, solution of Merck's sodium glycocholate in distilled water is placed in narrow test-tubes, and an equal amount of the patient's serum, which must be absolutely clear and inactivated by heating at 56° C. for thirty minutes, is added. This mixture and the known normal and luetic controls are kept at room temperature for from eighteen to twenty-four hours. A positive reaction is marked by the appearance of distinct coarse flocculi, mere turbidity or faint precipitation being regarded as negative. Herman-Perutz Reaction. — More recently Herman and Perutz have devised a similar test requiring the following two solutions : Solution 1 (stock solution, diluted 1 : 20 with distilled water before use) consists of: Sodium glycocholate, 2 gm., cholesterol, 0.4 gm.; 95 per cent, alcohol, 100 c.c. Solution 2 (freshly prepared before use) is a 2 per cent, solution of sodium glycocholate in distilled water. The test is performed by adding to 0.4 c.c. of clear inactive serum (heated at 56° C. for half an hour) in a small test-tube 0.2 c.c. of solution 1 and 0.2 c.c. of solution 2. The tubes are tightly plugged with cotton and set aside at room temperature for twenty-four hours, after which the presence or absence of precipitation is noted. It is well in this test, as in all immunologic reactions, to prepare controls with known normal and luetic serums and with distilled water. None of these reactions has been found specific, and none has been generally adopted, the far greater accuracy of the Wassermann reaction having made this method more valuable. Noguchi Butyric-acid Test. — Noguchi has devised a very useful test for the detection of an increased amount of protein, particularly globulin, in cerebrospinal and other body-fluids. In my experience this test has proved of particular value in establishing the differential diagnosis between serous and tuberculous meningitis, being negative in the former and positive in the latter, whereas in both the fluid may be clear, the cytology may be indefinite, and tubercle bacilli may escape detection. Serous meningitis is not a true infection, but a reflex vasomotor disturbance of the cerebral vessels, causing an outpouring of serum that leads to various pressure symptoms closely resembling those of a true meningitis. This condition is particularly common during childhood, and the general symptoms, the increased pressure of the cerebrospinal fluid, and its clear, watery character, are features that resemble those of tuberculous meningitis. It is just in such cases — and they are frequent — that I have found this protein reaction of considerable value. A positive underlying cause is corrected. Noguchi has found the test positive in about 90 per cent, of cases of general paralysis and in 60 per cent, of cases of locomotor ataxia or cerebral or spinal syphilis. In the diagnosis of syphilis the Wassermann reaction with cerebrospinal fluid has greater value than the protein reaction. However, the best results in diagnosis are usually secured by a Wassermann test, butyric-acid test, and total and differential cell-counts. In a case where the diagnosis rests between tuberculous meningitis and syphilis, a positive butyric-acid test and a negative Wassermann reaction would decide in favor of the former. The test is extremely simple. Into a small, thin-walled test-tube place 0.2 c.c. of cerebrospinal fluid (which must be clear and free from blood) ; add 1 c.c. of a 10 per cent, solution of butyric acid in normal salt solution; heat over a low flame and boil for a short period. Then add quickly 0.2 c.c. of a normal solution of sodium hydroxid and boil once more for a few seconds. The presence of an increased content of protein is indicated by the appearance of a granular or flocculent precipitate, which gradually settles to the bottom qf the tube, under a clear supernatant fluid (Fig. 88). The velocity and intensity of the reaction vary with the quantity of the protein contained in a given specimen. The granular precipitate appears within a few minutes in a specimen containing a considerable increase in protein, whereas one hour may be required to obtain a distinct reaction in specimens weaker in protein. In obtaining the reaction, the time period should not be greater than two hours. A faint opalescence without the frrwotion of a distinct precipitate is to be regarded as within the limits of the normal. McDonagh "Gel" Test. — McDonagh1 has recently advocated what he has designated a "gel" test for the diagnosis of syphilis. Clear and blood-free sera are employed, and it is necessary to include a known positive and negative serum each time the tests are conducted. Into each of three dry tubes place 2, 3, and 4 drops of serum, respectively; add 0.1 c.c. of acetic anhydrid and 1 c.c. of glacial acetic acid; the tubes are now well shaken and a drop of a saturated watery solution of ammonium sulphate added. Instead of acetic anhydrid and solution of ammonium sulphate the test may be conducted with 0.2 c.c. of a saturated solution of lanthanum sulphate, thorium sulphate, or thorium nitrate in glacial acetic acid. A preliminary reading may be made and a final reading 1 Brit. Jour, of Dermat., 1916, April- June, 114. after the tubes have stood over night. "In all the tubes at first crystals form, but in the tubes containing normal serum they often disappear in six to twenty-four hours, while they remain in the tubes with syphilitic serum." Strickler has used this test in my laboratory, and my observations of his results leads me to the conclusion that it is frequently difficult to interpret the reactions, and that the test has not by any means the practical value of the Wassermann reaction. FIG. 88. — THE NOGTTCHI BUTYRIC-ACID TEST FOR GLOBULINS. The tube on the extreme left shows the formation of flocculi within a few minutes after adding NaOH; the middle tube shows a strongly positive reaction after standing several hours (supernatant fluid quite clear) ; the tube on the extreme right shows a very slight opalescence, but no flocculi (within the limits of normal). PROTEIN PREOPITINS The protein precipitins have a larger range of value and represent one of the most important practical aids in forensic medicine. As mentioned elsewhere, a precipitating immune serum reacts only, or at least best, with its homologous serum. The precipitin reaction is, therefore, highly specific, and offers a method whereby proteins can be easily and definitely determined — a problem that could not be solved by chemistry. and their source determined. By using appropriate immune serums seminal fluids and stains may be detected, and in medicolegal cases, where the question is one of rape, this reaction possesses considerable value in differentiating seminal from leukorrheal stains. The precipitin reaction is likewise of great value in rnedicolegal cases in determining the source of blood-stains, the original application and technic having been largely worked out by Wassermann, Schutze, Uhlenhuth, and Weidanz. Thus in a case where, for example, a bloody towel is found in the possession of a man charged with murder, the prosecution may see in this a proof of crime, whereas the defendant may claim that the stains are those of dog's blood. Microscopic and chemical tests may show that the stains are blood-stains, but they cannot determine their source. The blood-stained towel is placed in water or salt solution, and a portion of the extract is mixed with the serum of a rabbitimmunized against human serum, and another portion with the serum of a rabbit immunized against dog's serum. If the first mixture shows a precipitate, the stain was made by blood from a human being; if, on the other hand, this mixture remains clear and the second shows a precipitate, this is strongly indicative of the presence of dog's blood. This method has also cleared up a number of scientific problems, especially that of showing the blood relationship of man and the lower animals. Just as a group agglutination demonstrates the close relationship existing between various bacteria, so, also, serum precipitins prove that a distinct relationship exists between the different species of animals. For example, an antihuman serum in low dilution will precipitate the serum of monkeys. The differentiation between human and monkey serum can be accomplished, however, by immunizing the monkey with human serum, when a precipitin is formed that' reacts with human serum alone, an isoprecipitin, or one active against the monkey's own serum, not being developed as a general rule. The precipitin tests are likewise of value in food inspection, as, for instance, to determine the nature of meats. For example, in order to detect the presence of dog or horse flesh in sausage, extracts of the sausage are made and tested with anti-dog and anti-horse serum, the presence of precipitates indicating strongly the presence of the meat of these animals. With an appropriate technic even salted and cooked flesh may be recognized, although when the meat has been cooked it is necessary to prepare immune serums by immunizing rabbits with extracts of cooked meats. In this connection it may be stated that specific organic reactions have been secured by various investigators by prolonged immunization of rabbits with certain organ extracts. Thus it is possible to differentiate between the liver and kidney of the same animals; such tests have, however, but limited practical value. Maragliano attempted to apply this test of organic specificity to the serodiagnosis of malignant tumors by preparing immune serums by the injection of tumor juices, securing a Unless a stain is definitely known to be a blood-stain it is necessary to establish its identity by making a chemical test before proceeding with the precipitin reactions. For example, old stains upon clothing may be due to substances other than blood, such as coffee and fruit-juices. Blood-stains upon clothing, metal, wood, or glass may be used for making these reactions and their source determined. To identify the stain as one of blood, a portion may be taken into solution in distilled water, rendered slightly acid with dilute acetic acid, filtered until clear, and examined spectroscopically. Or the Teichmann hemin crystal test may be applied to the stain by transferring to a clean slide a small amount of material scraped from the stain; add a few small crystals of sodium chlorid, crush the crystals, and mix the powder with the dry material. Place a clean cover-glass over the stained material and run a small amount of glacial acetic acid under the cover-glass. Heat the preparation to just about the boiling-point for a minute, replenishing the acid as may be necessary. The fluid turns brown. The specimen is allowed to cool a few minutes, and is then examined microscopically for the presence of brown rhombic crystals of hemin (Fig. 89). It may be necessary to reheat the specimen several times before the crystals are obtained. With stains in cloth and particularly those partially removed by washing, other chemical methods for detection, as the guaiac, benzidin, or Furth1 leukomalachite-green tests, must be employed. Having shown that a given stain is actually a blood-stain, the source of the blood may be determined as the result of the precipitin reaction, which consists in extracting the stain in normal salt solution and mixing with antiserums prepared by immunizing rabbits with human and various animal serums. Since the antiserums are known, a precipitate with any ' one of the extracts indicates that the blood in the stain was derived from The tube on the left shows the color of an extract of a blood-stain; the middle tube shows this extract so diluted as to yield a faint albumin reaction with nitric acid; the tube on the right shows the foam test with the same diluted extract (about 1 :1000). TECHNIC OF PRECIPITIN REACTIONS 327 the same species of animal. The reaction is based upon the principle of the specificity of antigen and its antibody. Here the antibody is known, and is used in the test to detect the antigen. As mentioned elsewhere, because of the presence of group precipitins the reaction is fraught with certain technical difficulties of importance, especially in medicolegal cases. In most instances it may suffice to show that a stain is of human blood, as will be indicated by a strong reaction with human blood and negative reactions with the bloods of lower animals. If the reaction is negative with antihuman serum, the antiserums of the domestic animals, such as that of the dog, cat, hog, ox, horse, etc., are tried. Although the blood of the higher apes, and even of the lower orders of monkeys, may react slightly with human blood, this factor may be determined by observing a proper technic of dilution, or the possibility of a given stain being one of monkey blood being definitely worked out. The reaction can be obtained from blood in an advanced state of putrefaction, or from a stain that has been dried for a year or more. Tests with mummies, however, have reacted negatively, and stains or clots altered by heat may not react unless the antiserum has been prepared with a similar antigen. This same technic may be employed for the recognition of seminal stains, especially in cases of rape. The stain is taken into solution in exactly the same manner as the blood-stain, and tested with an antihuman semen serum prepared by immunizing rabbits with human semen. Preparation of the Extract of Stain (the Precipitinogen).— If the stain is on clothing, a portion three inches square should be carefully torn into shreds with forceps and scissors, and not with the fingers, and placed in 40 c.c. of normal salt solution. If the stain is upon wood, glass, or metal, the staining substance should be carefully scraped off with a knife and placed in the salt solution. As a further control on the technic an unstained portion of the clothing should be extracted in the same manner, in order to show that the latter alone does not give the reaction. The mixtures must not be shaken, but should be stood aside for from two to twenty-four hours, depending upon the rapidity of extraction. The extract should preferably not be stronger than 1 : 1000. The strength may be estimated by removing 1 c.c. of the extract into another tube, diluting with from 10 to 20 c.c. of normal salt solution, and gently shaking. If a persistent froth appears upon the surface of the fluid, sufficient extraction has occurred. Place 2 c.c. in a test-tube, heat to boiling, and add a drop of a 25 per cent, solution of nitric acid. A faint opalescence indicates that the strength of the extract is about 1 : 1000 (Fig. 90). If a heavy precipitate forms, the amount of normal salt solu- tion that must be added to a portion of the extract to reduce it to a dilution of 1 : 1000 should be determined. The extract should be almost colorless by transmitted light, and must be crystal clear; this may be accomplished by filtering it through a clean sterile Berkefeld filter. It is highly desirable that the extract be sterile, as the reaction may require Serum is poured into the glass cylinder surrounding the "candle"; a vacuum is produced by the water-pump; the nitrate is collected in the small bottle attached by rubber tubing to the graduated cylinder at the lower portion of the apparatus. This filter is especially adapted for filtering small amounts of serum or other fluid. the result. The Immune Serum. — A highly potent, sterile, and absolutely crystal-clear serum immune against the protein to be recognized must be prepared. The method of preparation is given in the chapter on Active Immunization of Animals. For the recognition of blood-stains it is not necessary that whole blood be injected, as the serum alone will suffice. It is better to inject a number of rabbits with each serum and to give all injections intravenously. From the third injection on, preliminary titrations are made according to the technic to be described later, as many animals succumb after a large number of injections have been given them. The serum must be absolutely clear. Animals should be bled after a period of fasting, as the opalescence of the serum following feeding cannot be removed by filtration and will interfere with the reaction. Precipitin immune serum should be collected with a scrupulous aseptic technic, and stored in ampules holding 1 c.c. Although it is best not to add a preservative, the addition of 0.1 c.c. of a 1 per cent, solution of and aids greatly in its preservation. If, after long standing, a precipitate has become deposited in an antiserum, this should not be shaken up, but the ampule should be carefully opened and the clear supernatant serum drawn off with a capillary pipet. A serum that has become cloudy may be cleared partially or entirely by filtering it through a small candle filter, although even an infected and offensive serum will give the reaction (Fig. 91). used. These must be absolutely clean, and preferably sterile. The test-tube rack devised by Uhlenhuth, in which the tubes hang suspended in beveled holes, is quite satisfactory. Where a test is carried out with many controls, a rack similar to the one shown in the illustration (Fig. 92) is quite serviceable. A strip of black material placed be- escence or precipitation. Preliminary Titrations. — The precipitin content of an immune serum is titrated frequently during the process of immunization and after the animal has been bled. For medicolegal purposes, Uhlenhuth advises the use of only highly valent serums. He considers an antiserum ef- Not all tubes of the series are here shown. Note the well-marked precipitate in the bottom of the first two tubes (1 : 100 and 1 : 500); the third tube (1 : 1000) shows less precipitate; the fourth tube (1 : 2000) is negative (clear and no precipitate). The titer of this serum was recorded as 1 : 1000. ficient if 0.1 c.c. of it, when added to its respective serum-antigen diluted 1 : 1000, produces a distinct turbidity, either at once or in from one to five minutes at the latest. Into a series of six test-tubes place 2.0 c.c. of the following dilutions of serum-antigen, prepared with normal salt solution: 1:100, 1:500, 1:1000, 1:2000, 1:5000, and 1:10,000. To each tube add 0.1 c.c. of clear immune serum. The tubes must not be shaken. Within from one to five minutes a faint, misty cloud appears at the bottom of the tubes reacting positively, and this becomes a distinct precipitate within onehalf to one hour (Fig. 93). Before performing the actual test with the unknown blood-stain it is advisable to test the entire reaction with a similar known blood-stain in order to make sure that all ingredients are in good working order. In laboratories equipped for medicolegal examinations stains upon linen, as by the blood of man, dog, cat, ox, horse, etc., and their respective antiserums are always kept in readiness for making the preliminary and actual tests. Tube 5: 2 c.c. of a 1:1000 dilution of the serum of that species of animal whose blood is suspected to be present in the unknown solution +0.1 c.c. of immune serum (control). The tubes are not shaken, are kept at room temperature, and the results are read after from ten to twenty minutes. Exposure to incubator temperature facilitates the reaction. With proper immune serums, and especially in medicolegal work, a positive reaction should appear within two to five minutes as a faint, misty cloud at the bottom of the test-tube. Within five minutes this becomes more definite, and in from ten to twenty minutes the precipitate is seen (Fig. 94). Any cloudiness that develops later than twenty minutes after the beginning of the reaction has no significance. The first tube, containing a 1 : 1000 dilution of the blood (extreme left), shows a well-marked precipitate; in the second (1 : 2000) the reaction is also well marked; the third (1 : 5000) shows no precipitate; the fourth contains a 1 : 1000 dilution of blood-stain, with normal rabbit serum as a control, and shows no precipitate; the fifth is the positive control with known sheep blood extract and immune serum; the last tube is No. 8 of the series, and contains an extract of the non-bloody portion of the towel with immune serum; no precipitate. 3 and tube 5, and all the others react negatively, the presence of the blood or protein of the species suspected in the unknown extract is established. If the entire test proves negative, the species to which the unknown specimen belongs must be determined with new antiserums prepared for each species, and the tests conducted in the manner described. Partial reactions between closely related species due to group precipitins seldom occur, and are easily detected when the technic described is employed. The precipitin test, as determined by the extensive experience of Nuttall, is highly specific, and it is only between very closely related animals, such as the hare and the rabbit, the horse and the mule, the sheep and the goat, etc., that any doubt can arise. When only very limited amounts of the unknown stain are available, the test, according to Hauser, can be carried out in slender, clean, and sterile capillary tubes. The piece of stained clothing is torn into shreds, extracted, and filtered until clear. The tests are performed by drawing a small amount of the unknown solution into a capillary tube, and underlying this with a small amount of immune serum. As many controls as possible are put up in the same manner. A distinct whitish ring will form in the positive tubes at the line of contact between the two fluids; this is best seen by holding the tube against a black background. DETECTION OF MEAT ADULTERATION The principle of this method is the same as that in the foregoing test. An extract of a meat will yield a precipitate when mixed with its antiserum, prepared by immunizing rabbits with an extract of the flesh or with the blood-serum of some other animal. The method is especially serviceable in food inspection for the detection of horse, dog, or other foreign flesh in meat mixtures, such as sausage and the like. Even salted and cooked meats may be used in the test, although the latter may require the use of antiserums prepared by immunizing with heated or cooked antigen. Preparation of the Meat Extract. — To prepare this, about 50 grams of flesh are removed from the deeper parts of the specimen by means of a sterile knife, and through a fresh opening, as this portion has been least exposed to the methods of preservation, especially at the high temperatures to which the meat may have been exposed. It is then placed on a clean sterile tile and cut into smaller pieces, and finally minced by passing it through a perfectly dean meat-grinder or chopping it with a sterile chopping knife. After being finely minced the meat is placed in a sterile Erlenmeyer flask, and covered with 100 c.c. of sterile normal salt solution. The mixture of meat and salt solution is kept for about six hours at room temperature, or overnight in the refrigerator, the flask being gently shaken from time to time. flask. Since the presence of a great deal of fat interferes with the reaction, it is advisable to remove it beforehand by extracting it with ether and chloroform for from twelve to twenty-four hours (Miessner and Herbst). Pork sausages are usually quite fatty, and may require this preliminary treatment. To make the extraction, take about 75 to 100 grams of the minced meat or sausage and place it in a large Erlenmeyer flask and cover with equal parts of ether and chloroform. After twenty hours the ether and chloroform are poured off, the meat is washed once or twice with sterile normal salt solution, and then extracted hi 100 c.c. of salt solution, as described elsewhere. To determine whether a sufficient quantity of protein substances has passed into solution place 2 c.c. in a test-tube and shake vigorously. If a foam develops and persists for some time, the extraction may be said to be complete. It must then be filtered until it becomes perfectly clear. With extracts of fresh lean meat this is usually accomplished by filtering through a hard filter-paper moistened with salt solution. If it is not crystal clear, and especially if the meat to be examined is fat or salt, it may be necessary to filter through a sterile Berkef eld filter. To make the test the extract should contain about one part of protein in 500 parts of salt solution. To determine this, 2 c.c. of the clear filtrate are placed in a test-tube and heated, a drop of dilute nitric acid being added. If a marked cloudiness and a flocculent precipitate develops, the extract is too concentrated and must be diluted with clear normal salt solution until the heat and acid test causes only a diffuse, opalescent cloudiness that settles at the bottom of the tube after five minutes as a slight precipitate. Before proceeding with the experiment the reaction of the solution should be tested with litmus paper, and if it is found to be acid, it should be neutralized very carefully with ^ sodium hydroxid. extracts of pork and beef, should be prepared as controls. Preparation of Immune Serum. — An immune serum against that variety of flesh that is to be determined in the unknown specimen is prepared by injecting rabbits intravenously with the serum of an animal of that species. For example, if the object is to test for dog meat, an anti-dog serum is prepared by immunizing rabbits with sterile dog serum. As has repeatedly been mentioned, it is advisable to immunize a number of rabbits at the same time, for only a small number will yield a satisfactory serum after the third injection. Immunization may be performed with extracts of flesh that have been filtered and heated at 56° C. for an hour to secure partial sterilization. Such injections, when given subcutaneously, are likely to produce extensive sloughing, and with any method of immunization the mortality is high. After the third inoculation it is well to remove a small amount of blood from the ear and make a preliminary titration. This is performed in exactly the same manner as in making the forensic blood test previously described. An antiserum is satisfactory if 0.1 c.c. produces a well-marked cloudiness and a precipitate in ten minutes with 2 c.c. of a 1 : 1000 dilution of the serum or extract of flesh. after a period of fasting. Technic. — If, for example, the object is to determine whether a piece of meat is horse flesh or, if sausage, contains the meat of this animal the test is conducted as follows : rabbit serum. Tube 6: 2 c.c. of pork extract, 1 : 500+0.1 c.c. of antihorse serum. Tube 7: 2 c.c. of beef extract, 1 : 500+0.1 c.c. of antihorse serum. Tube 8: 2 c.c. of unknown extract. Tube 9: 2 c.c. of sterile salt solution+0.1 c.c. of antihorse serum. The immune serum is added to each tube very carefully and run down the sides of the tube, rather than dropped into them. The tubes should not be shaken. If the preliminary titration of the immune serum fulfils the ideal requirement of yielding a well-marked cloudiness within five to ten minutes with a 1 : 1000 extract, the foregoing test should be recorded at the end of half an hour at room temperature. If in tubes 1, 2, 4, and possibly 3 a misty cloudiness should appear within five minutes, the extract is very probably one of horse flesh. If a definite precipitate forms within thirty minutes, the other tubes remaining clear, horse flesh or the flesh of some other single-toed animal is present. If the preliminary titration does not show a precipitate with the immune serum until at the end of one or two hours, this interval may be utilized for conducting the test. As has previously been stated, these precipitins have slight diagnostic significance, as the information they yield in the diagnosis of an infection or in the differentiation of bacterial species may be gained much more easily with the agglutinin test. Bacterial precipitinogens are prepared by filtering ten to twenty-one day bouillon cultures through Berkefeld filters. The filtrates must be absolutely clear and sterile, for the reaction frequently requires a number of hours, and if bacteria are present, they may grow quickly, produce turbidity, and mask a reaction. Immune Serum. — This is prepared according to the technic described under Active Immunization. Rabbits are given intravenous injections of increasing doses of cultures of the bacteria themselves or of filtrates, the inoculum being heated at 60° C. for an hour previous to making the injection. After the third dose the serum is titrated and the injections continued unless the serum is satisfactory. Technic. — A known quantity of precipitinogen and varying amounts of immune serum are employed. If too much precipitinogen is furnished, the precipitate will not form, and one that has already formed may dissolve on the addition of more precipitinogen. Tube 7: 2 c.c. of typhoid bouillon filtrate+1 c.c. of normal serum. Tube 8: 1 c.c. of serum+1 c.c. of normal salt solution. The tubes are not shaken, and are kept at room temperature for from one to six hours. If the unknown serum contains considerable typhoid precipitins, a positive reaction will be noticed in the first four tubes in a short time — often within from ten to fifteen minutes. Tube 5 should show a strong reaction and the other tubes should remain clear. In studying the biologic relationship of an organism to others of the same group its immune serum may be used in amounts of 1 c.c. of varying dilutions, as 1:50, 1:100, 1:500, 1:1000, 1:2000, 1:4000, and so on, with a constant dose of 1 or 2 c.c. of the bouillon filtrates of the various organisms studied. A comparison of the precipitates in the respective dilutions of the different filtrates indicates the relationship, according to the amount of group precipitins present in the immune serum. Amboccptors and Complements THE cytolysins include a number of antibodies of considerable diagnostic and therapeutic importance, for example, the hemolysins and the bacteriolysins. It will be remembered that the various antibodies act differently upon their antigens, and that, according to the side-chain theory, as their antigens become more highly organized, their structure becomes more complicated. For example, the molecule of a soluble toxin may be considered as simple in structure, and accordingly its antibody has been conceived as being likewise simple, and composed of a plain cast-off receptor or side-arm that unites directly with the toxin and neutralizes it without further aid. Antitoxins and antiferments are antibodies of this nature. For more highly organized antigens, however, so simple an antibody will not suffice, and we now find a more complicated antibody, composed of a portion that unites with the antigen and another portion, an integral part of the antibody, that exerts a special selective action upon the antigen, and either neutralizes its activity or prepares it for ultimate destruction. To this class of antibodies belong the agglutinins and precipitins, which agglutinate or precipitate their antigens preparatory, in a sense, to their final disintegration. For still more complex antigens nature has provided special ferments, always present in varying proportions in the blood, which, when united with the antigen, cause its disintegration and solution in a manner similar to the process of digestion as it takes place in the intestinal canal. These ferments are, however, powerless unless united with the antigens, and here we find that the antibody serves as the connecting link, bindiaguantige.il with ferment, which results in a form of digestion and final lysis or solution. The antibody is, therefore, simple in structure, and is composed of two binding or grasping arms — one for the antigen and one for a ferment. This interbody, or amboceptor, is specific for the antigen, and will act only and specifically with this antigen. It is important to remember that the ferment or complement is not an integral part of the antibody, but is free in the blood-stream; that the antibody is only a connecting link, but preserves its importance by being specific for its and complement, and that the latter then causes the lysis or solution of the antigen. The connecting link or antibody of this nature is known as an antibody or receptor of the third order. Different cells produce their own and specific interbodies or amboceptors. Thus bacteria or vegetable cells, blood-corpuscles, and various other cells, such as ciliated epithelium, spermatozoa, renal epithelium, etc., when present in the form of an infection or when injected into an animal, generate different and specific amboceptors, which bring about their solution by binding them with a ferment or complement. One ferment or complement does not serve for all; there are various ferments, which act with the different amboceptors, but all have properties so nearly alike that many believe, with Bordet, that but a single complement exists. Definition. — This special digestive and lytic process is known to occur with cells, and hence the antibodies capable of bringing about this action are called cytolysinSj or substances that cause lysis or solution of the various cells that may be their antigens. It is well to remember that, according to Ehrlich, the three orders of antibodies each have their counterpart, both in structure and in effect, in the receptors serving for the normal nutrition of cells. For the simplest molecule of food that is in solution the cell is provided with a simple receptor for union with the molecule, which is then directly assimilated. This receptor is similar to an antitoxin, or an antibody of the first order, which destroys its toxin directly and without further ado. More complex food material must first undergo some preparation by the cell before it can be assimilated, and accordingly we find receptors provided with a more complex structure which have their counterpart in the antibodies of the second order, or those possessing a special toxic portion that agglutinates or precipitates their antigen or prepares it for phagocytosis. It is possible that with physiologic substances this is all that the cell requires of its receptor, but so far as is known, it would appear that for antibodies this action does not in itself injure the antigen, but is rather one step toward preparation for its further destruction. Organized and complex food substances must be digested before assimilation can occur, and here we find that the receptor acts as a link in binding the food molecule to a ferment, with resulting dissolution and assimilation of the products of solution. These are called receptors of the third order, and have their counterpart in similar antibodies, — the cytolysins, — which act as links or interbodies between antigen and a complement, the latter being entirely free and separate, and independent of the receptor or antibody (interbody) itself (Fig. 95). CYTOLYSINS Varieties of Cytolysins. — The cytolysins produced by bacteria are known as bacteriolysins, i. e., antibodies producing disintegration and lysis of bacteria. The cytolysins known as hemolysins cause lysis or hemolysis of the erythrocytes. Similar cytolysins may be formed for practically all cells, such as leukocytes, epithelium, liver, kidney, spleen, etc., and to these the general name cytotoxin has been given; thus we have leukotoxin, hepatotoxin, nephrotoxin, neurotoxin, etc., these R, Receptor of the molecule '(third order) ; R2, overproduction of receptors, which are being cast off; A, a cast-off receptor which now constitutes the antibody or amboceptor; C, molecule of complement free in the body-cells and body-fluids; A2 A4, amboceptors in combination with molecules of a cell (antigen) and a complement; A3, an amboceptor in combination with a molecule of a cell. The cell (antigen) is now said to be sensitized. Lysis does not occur because a complement is not united. by which their action is produced. Nomenclature. — In no other field of immunity have so many different names been applied to the same substances as have been applied to this order of antibodies. This confusion of terms, added to the various interpretations placed upon their significance, has rendered the subject incomprehensible to those not specially interested. AMBOCEPTORS 341 alexin by Bordet; Metchnikoff called it cytase, and-Ehrlich designated it as complement because in the conception of the side-chain theory it completes the reaction after being linked with the antigen. The term "alexin" was first applied by Buchner to the germicidal substance found in normal serum. We now know that Buchner was working with both amboceptor and complement, although Bordet was the first to discover the former, Buchner having been unconsciously most interested in the thermolabile complement. To the antibody itself the term substance sensibilisatrice has been applied by Bordet, for he believes that this antibody sensitizes or prepares the cell for the action of the alexin or complement. The following names have been applied to the antibody by various observers : fixateur, by Metchnikoff; preparator, by Mliller; and amboceptor, interbody, and immune body by Ehrlich. Of these, the term "amboceptor" is in most general use, signifying a two-armed body that unites antigen on the one hand, with a complement on the other. When using the term amboceptor, care should be used to designate its specific character; thus, for example, a hemolytic amboceptor and a bacteriolytic amboceptor mean respectively a hemolysin and a bacteriolysin. It is common practice to designate an amboceptor according to the cell for which it has a special affinity; thus antisheep amboceptor or hemolysin means an amboceptor for sheep cells, the prefix "anti" being affixed because it is destructive for those cells. Although antitoxins have received considerable study from a therapeutic standpoint, probably no order of antibodies has been given more attention than the cytolysins have received, not only because of their vast therapeutic possibilities, but also from their value as an' aid to diagnosis. The hemolysins especially have been utilized in making the Wassermann test for syphilis and similar reactions, the very nature of the phenomenon offering a visible and fascinating method of study. Since the general structure, formation, and action of the various amboceptors, such as the bacteriolysins, hemolysins, and other cytolysins, are essentially similar, the general character of amboceptors may be here considered, a study of the special characteristics of each being reserved for subsequent chapters on the more important members of the group. of course, present in the various serums with which these observers were working, but it was not until 1895 that Bordet showed quite clearly that two substances were concerned in the phenomena of bacteriolysis and hemolysis. At this time he demonstrated that the alexin or complement may be removed from a serum by heating it to 55° to 56° C., and that it may be reactivated by the addition of fresh serum from another animal; that an old bacteriolytic serum cannot produce bacteriolysis unless it is reactivated by a fresh normal serum or is placed in the peritoneal cavity of a living animal, from which it may derive the thermolabile alexin. In other words, the amboceptors in these serums withstood the effects of heating and age, but were unable to produce lysis without the aid of an alexin furnished by a fresh normal serum. Structure of Amboceptors. — According to the theory of Ehrlich, an amboceptor is but a simple interbody furnished with two haptophore or grasping portions. One haptophore group attaches the antibody to its antigen, whatever that may happen to be — bacterium, erythrocyte, epithelial cell, e.tc., while the other attaches a suitable complement (Fig. 95). The first is called the cytophile or antigentophile group, and the second, the complementophile group. The amboceptor is specific in the sense that it will unite only with its antigen or other very closely related body. For example, when a rabbit is injected with sheep corpuscles an amboceptor is formed that will unite only with sheep, and not with human, dog, ox, or other cells. As will be shown further on, Ehrlich believes that many different complements may be present in a serum, whereas Bordet believes that one complement exists that will act with the amboceptor, whether this is bacteriolysin or hemolysin. This view is based mainly upon the observation that the complement in a serum may be absorbed out by furnishing an excess of either bacteriolytic or hemolytic amboceptors, the one variety of amboceptor removing all the complement for the other. Although the results of experimental work would seem to indicate that Ehrlich's belief in the plurality of complements is correct, and while this view is quite generally held, conclusive proof regarding this has not as yet been furnished. An amboceptor may have more than one complementophile group, and may bind a number of different complements simultaneously (polyceptor) (Fig. 96). Ehrlich and Morgenroth called attention to this possibility when they stated: " Finally, it is possible that an immune body, besides one particular cytophile group, contains two, three, or more complementophile groups." Later Ehrlich and Marshall showed that, in order to get a specific lytic effect, it was not necessary for all complements to become active, but that only a few are necessary in any single instance to bring about effect. These complements are termed " dominant complements," the remainder being known as " non-dominant complements." Whether amboceptors can undergo degenerative changes and lose their cytophile or complementophile groups and become amboceptoids, just as toxoids and agglutinoids are formed, is still doubtful. Reasoning from analogy to the toxins and agglutinins, it is probable that amboceptoids may be produced by a loss of the complementophile group, the cytophile portion of all antibodies being more stable; such amboceptoids, by uniting with their antigens, may effectually block the action of an amboceptor, just as agglutinoids prevent agglutination. General Properties of Amboceptors. — Amboceptors are fairly resistant bodies, withstanding to a well-marked degree the effects of heat, acids, alkalis, exposure, and drying. A hemolytic serum, for instance, may be preserved in a sterile condition for many months and show but slight deterioration in its activity. Such a serum may be dried in vacuo or on suitable filter-paper, and preserve its activity for remarkable inter- FIG. 96.— THEORETIC STRUC- in activity. Mechanism of the Action of Amboceptors. — An amboceptor or antibody of the third order is believed to act as a simple chemical interbody between antigen and complement — i. e., it is a connecting link between the two. Complement is, therefore, the active agent in lytic processes, but is practically powerless to act upon the antigen until brought into chemical union through the intervention of an amboceptor. Complement is present in normal serums, and its quantity cannot be increased by immunization. Amboceptors are specific for their antigen, may be present in small amounts in a normal serum, but may be greatly increased during infection or as the result of artificial immunization. A hemolytic amboceptor for sheep corpuscles is specific for these, and will not unite with the corpuscles of any other animal. A bacteriolytic amboceptor as for Bacillus typhosus will unite only with those bacilli, and to a lesser extent with closely related bacilli, such as the paratyphoids but not with other bacterial species or other cells. As to the specificity of complement, opinions differ. Ehrlich believes that there are many complements, as, e. g., one for a particular hemolytic amboceptor, another for a bacteriolytic amboceptor, and so on through the extensive list of known amboceptors. Bordet, on the other hand, believes that there is but one complement, which will act with any amboceptor. Bordet's conception of the mechanism of this order of antibodies is also different from that of Ehrlich. Both agree that the antibody prepares the cell for the lytic action of a complement, but Ehrlich holds that the antibody acts as a simple link between antigen and complement, whereas Bordet believes that the antibody acts as a mordant or dye, penetrating its antigen, and sensitizing or preparing it for the action of the complement. For this reason Bordet calls these antibodies " sensitizers," or substances sensibilisatrice. The term " sensitizing " is now in general use, and is employed especially in hemolytic tests when corpuscles or bacteria are mixed with their amboceptors to effect their union. It is expressive and satisfactory, and may be used without necessarily subscribing to Bordet 's view. Metchnikoff believes that amboceptor or his "fixator" is found in the leukocytes. He asserts that the amount of fixator or amboceptor produced is proportional to the amount of phagocytosis and phagolysis that occur during the absorption of the antigen. Metchnikoff considers the fixators as analogous to enterokinase, and he believes that, like the latter, the fixator acts as an accessory digestive ferment, having for its object the linking of the more potent ferment, as a cytase or complement, to the cell or molecule to be digested. Formation of Amboceptors. — While experimental data are at hand to show that amboceptors may be produced by local tissues, it is entirely probable that in wide-spread infection or as the result of artificial immunization there is general cellular activity with extensive antibody formation. The spleen and hematopoietic tissues in general and the mononuclear leukocytes are regarded by many as being particularly active in the formation of hemolysins and bacteriolysins (Pfeiffer and Marx, Deutsch, Wassermann). As has been stated, Metchnikoff believes that antibodies of the class under consideration are the products of the leukocytes, thus tending to preserve the importance of the phagocytic theory. While there is little doubt that the various leukocytes, endothelial cells, and other phagocytic cells are sources of amboceptor production, there is no reason for accepting the belief that their formation is confined strictly to these cells. Specifitity of Amboceptors. — It has been stated elsewhere in this volume that amboceptors are highly specific bodies. This specificity is not, however, absolute, for just as group agglutinins are produced by one bacterium for closely allied species, so in like manner experimental investigation by Ehrlich and Morgenroth, von Dungern, and others has shown that immunization of an animal with the erythrocytes of another animal would produce one chief hemolysin for these cells and a secondary hemolysin for the cells of another animal. For example, on immunizing a rabbit with ox blood a hemolytic serum was obtained that was hemolytic not only for goat blood, but also for ox blood. These secondary amboceptors are known as group or partial immune bodies. Their production may readily be understood when it is remembered that the body-cells are conceived as being provided with various side-arms for many different blood-cells, bacteria, etc. Now, if the erythrocytes of the goat possess receptors not only for the particular goat-blood sidearms of the body-cells, but also for the ox-blood side-arms, both sets of side-arms will be attacked and consequently two amboceptors are formed — one, the main one, for goat corpuscles, and a secondary one for ox corpuscles. Ehrlich and Morgenroth, therefore, claim that the immune body of a hemolytic serum is composed of the sum of the partial immune bodies, which correspond to the individual receptors used to confer the immunity. Since the cells of various animals of the same and of different species vary in the number and variety of side-arms or receptors, which are not present in another, the different combining group possessed by a blood-cell or a bacterium will not, therefore, find fitting receptors in every animal, and thus there may be a different variety of partial immune bodies in two animals. This would lead to the possibility of the occurrence of antibodies for the same blood-cell or bacterium, differing from one another in the partial immune bodies of which they are composed, depending on the variety of the animals used in preparing the serum. This view is directly opposed to that of Metchnikoff and Besredka, who believe that a certain immune body is always the same, no matter what species of animal was used in preparing the serum. As will be pointed out further on, in addition to theoretic interest, the subject possesses great practical importance, for, as is well known, most curative serums are best prepared with many different strains of a particular microorganism because of certain differences in their antigenic properties, and if, in addition, the value of a bacteriolytic serum depends upon the sum-total of the immune bodies, it may be advisable to secure of the same and of different species. It will be understood, therefore, that the specific action of antibodies of this order is not limited to the cells used in the immunizing process, but extends to other cells that have receptors in common with these, a condition that is analogous to group agglutinins and precipitins for closely allied cells and bacteria or dissolved albumins. NATURAL OR NATIVE AMBOCEPTORS Difference Between a Normal and a Specific Immune Serum. — Just as small and varying amounts of native agglutinins and antitoxins may be found in normal serums, so, in like manner, various native bacteriolytic and hemolytic amboceptors may be found. According to the sidechain theory, these various amboceptors are normally attached to bodycells, hence it is probable that a few are being continually swept off into the blood-stream. In some instances the amount of a natural amboceptor may be quite high; thus, for example, many human serums contain relatively large amounts of antisheep hemolytic amboceptor. These natural amboceptors will be considered more fully in the chapters on Hemolysins and Bacteriolysins. The difference between a normal and an immune serum lies in the fact that the normal serum contains a number of amboceptors in small amounts, whereas the immune serum contains a greatly increased amount of at least one amboceptor for a particular cell. As has been shown by numerous investigators, this difference is not due to the complements, as these are not increased during the process of immunization. Since the presence of an amboceptor cannot be demonstrated unless complement is present, in testing a serum for an amboceptor we must furnish sufficient complement to bring out the maximum activity of the amboceptor. If the serum of a rabbit before and after immunization is titrated with sheep erythrocytes, it may be found that the immune serum contains from a hundred to many thousand times the normal quantity of antisheep amboceptor. These facts bear a further practical relation to the treatment of infectious diseases with bacteriolytic serums. Ordinarily, when we inject an immune serum we furnish but one bactericidal substance, namely, the bacteriolytic amboceptor, and no complement at all. If the patient's complement is decreased or at least insufficient to activate the amboceptor furnished, lysis will not occur, and accordingly an increased therapeutic effect may be secured by the injection simultaneously of ter on Passive Immunization. Anti-amboceptors. — Just as anti-agglutinins and antiprecipitins may be formed, so anti-amboceptors may be produced experimentally by immunizing an animal with an amboceptor-laden serum. An antiamboceptor is specific for the amboceptor that caused its production, and when these are mixed, the activity of the amboceptor is impeded by the anti-amboceptor, which unites with its cytophilic group. It is possible that old erythrocytes are destroyed by an autohemolysin present hi the blood-stream under normal conditions, and that a physiologic equilibrium is maintained through the production of an anti-amboceptor. Titration of a Hemolytic Amboceptor. — The quantity of amboceptor in a given amount of serum may be determined by titration. If, for instance, a rabbit is injected with sheep corpuscles, the amount of hemolytic amboceptor for these cells in the rabbit serum may be determined by the following method of titration: To a series of test-tubes increasing amounts of the rabbit immune serum (heated to remove complement) are added, with a constant dose of sheep-cells and a constant dose of fresh guinea-pig serum to furnish complement. After a suitable period of incubation the tube showing complete hemolysis would contain sufficient hemolytic amboceptor, i. e., just one unit. The value of the immune serum may then be expressed by stating that so much serum, as, e. g., 0.001 c.c., contains one unit of amboceptor. Of course, if the amounts of complement or corpuscles are varied the unit will likewise vary. In order to establish or measure the content of hemolytic amboceptor a constant amount of corpuscles and complement must be used. The details of this amboceptor titration are given in the chapter on Hemolysins. Titration of a Bacteriolytic Amboceptor. — A bacteriolytic amboceptor may be measured in much the same manner as a hemolytic amboceptor, although less accurately, because of technical difficulties. If a standard and fixed dose of an emulsion of living bacteria and a fixed dose of complement are mixed with varying amounts of inactivated immune serum containing amboceptors for these bacteria, the amount of amboceptors present may be determined by plating the mixture and estimating the number of bacteria that have been killed. Or we may use fixed doses of immune serum and complement with varying amounts of bacteria and Historic. — As early as 1876 Landois described the hemolytic action of fresh blood-serum upon the blood-corpuscles of animals of certain species. Traube and others observed that animals could withstand the injections of relatively large amounts of septic material, but it was not until 1886-90 that Fodor, Nuttall, Buchner, and others fully established the bactericidal properties of fresh blood-serum. Buchner demonstrated the fact that the active principle causing bacteriolysis or hemolysis is very labile, and can be inactivated by a temperature of 55° C., by dialysis, or by dilution with distilled water. He designated the active principle "alexin." Subsequently, in 1899, Bordet found that the alexin of Buchner was composed of two distinct substances — one a sensitizing substance, which is thermostabile, and a second, the thermolabile substance. Somewhat later (1899) Ehrlich and Morgenroth confirmed these observations, but applied the name "amboceptor" to the sensitizing substance and "complement" to the alexin. These terms are most widely employed at the present time. Bordet adheres to the term alexin, meaning thereby the thermolabile principle, and does not use it in the original sense of Buchner, which included both the sensitizing substance and the alexin. Metchnikoff's cytases are practically the same as Ehrlich's complement and Bordet's alexin. J Definition. — Complement [Lat., complementum, that which completes] is the substance, present alike in normal and in immune serum, which is destroyed by heating to 55° C., and which acts with an amboceptor to produce As mentioned in the discussion on amboceptors, the complement is the active lytic substance concerned in the phenomenon of cytolysis, but is powerless until united with the cell, corpuscle, or bacterium by means of the interbody or amboceptor. Structure and General Properties of Complement. — Complement is ordinarily not attached to the body-cells and is free in the blood-serum. According to Ehrlich, complement is simple in structure, and is composed of a haptophore portion for union with the complementophile haptophore of an amboceptor, and a second toxic or lytic portion, called the different. By heating a complement serum to 55° C. for half an hour the cytophile portion is destroyed, and the serum is now said to be inactivated, as the complement is no longer active. If the complement serum is allowed to stand at ordinary room temperature for forty-eight hours or longer, the same change will take place. The cytophilic or active portion of the complement is, therefore, quite unstable. When this portion is altered or lost, the substance is called complementoid, and this is analogous to toxoids and agglutinoids. Since complementoids have their haptophore groups intact, they will unite with amboceptors and to some extent prevent lysis by blocking the active complement, just as toxoids unite with antitoxin and agglutinoids with their antigens. Anticomplements may be obtained by immunizing suitable animals with serums that contain complement or complementoid. When an inactivated anticomplement serum is mixed with the homologous complement, the haptophores of the latter are bound by means of the haptophbres of the anticomplements. A proof of this union lies in the fact that a complement serum that has been treated with its specific anticomplement is no longer able to activate an appropriate amboceptor. According to Gay, the production of anticomplements is only apparent; he explains the loss of complement activity when a fresh serum and its antiserum are mixed as due to the absorption of complement in the precipitate which forms, although the latter may be invisible. Anticomplements may be of practical importance owing to the formation of auto-anticomplements. The complements must exercise an important function, not only in the destruction of bacteria, but also in the digestion and solution of all kinds of foreign albuminous bodies that enter the organism. As was shown by Wassermann, anticomplements may so bind up their complements as to render then host much less resistant to certain infectious diseases. The spontaneous development of auto-anticomplement in an animal has never been demonstrated, as there are no receptors in an organism of the complements of the same organism. The injection of the serum of another animal containing complements that are almost identical may, however, lead to the formation of an auto-anticomplement in the serum of the immunized animal. active serum is one containing complement, and this must, under ordinary circumstances, be a fresh serum. On heating or exposure the serum becomes inactive. An inactivated serum may be reactivated by the addition of fresh complement serum. These terms are in general use, especially in testing for hemolytic and bacteriolytic reactions. Origin of Complement. — Buchner regarded complement as a true secretory product of the leukocytes, and Metchnikoff also maintains that leukocytes are the main source, the complement being liberated upon disintegration of the white cells. There is considerable experimental evidence both for and against these views, but at the present time the consensus of opinion would tend to regard the leukocytes as an important, but not necessarily the sole, source of complement formation. Complement has been demonstrated in plasma, where its presence is probably due to continual disintegration of leukocytes and liberation of complement during life. It is probably increased to a slight extent as serum is left in contact with the blood-clot, indicating that disintegration of leukocytes may augment the complement supply. The liver (Muller and Dick), pancreas, and other organs have been regarded as sources of complement formation, but in general the evidence points to the leukocytes as the chief source of supply, the liver being probably concerned through its activity in blood destruction. Multiplicity of Complements. — Ordinarily, a fresh serum, such as that of the guinea-pig, will furnish complement for either bacteriolytic or hemolytic amboceptors, and the question arises as to whether one complement unites equally well with all amboceptors, or whether several complements are present in one serum that act more or less specifically with different amboceptors. Bordet believes that only one complement is present, and bases this opinion mainly on the fact that a complement that can be shown to activate either a hemolytic or a bacteriolytic amboceptor may be absorbed out of a serum by furnishing an excess of either amboceptor. Metchnikoff maintains that there are two cytases or complements, one being derived from macrophages and mainly hemolytic, and the second derived from microphages and chiefly bacteriolytic. Ehrlich and Morgenroth, Sachs, Wassermann, Wechsberg, and the German school in general believe that many different complements are present in amounts varying with the different serums. These observers have sought to prove this experimentally, and while the evidence is not absolutely convincing, because of the difficulty of working with sub- ments is quite generally accepted. (a) By digesting 20 c.c. of fresh goat serum that was found to activate different hemolytic amboceptors with 3 c.c. of a 10 per cent, solution of papain in the incubator for from thirty to forty-five minutes, it was found that the complement for one amboceptor was destroyed, whereas those remaining were left intact or but slightly impaired. (6) By treating 10 c.c. of this goat serum with 1 c.c. of a 7 per cent, solution of soda for an hour it was found that some complements were destroyed and others were weakened. (c) By sensitizing different blood-cells with homologous amboceptors and adding these to a fresh serum for short and varying periods of time, some complements could be destroyed, whereas others would be left behind with undiminished or but slightly decreased activity. Prolonged exposure would remove all complements. (d) As was previously stated, anticomplements may be produced by immunizing an animal with the complement of an animal of a different species. The anticomplements appear to be specific for the complements responsible for their production, and by means of these anticomplements different complements may be demonstrated in one serum. Since the formation of anticomplements would depend upon whether or not the body-cells of the immunized animal possess suitable receptors for the various complements, in a series of animals it may be found that one does not produce anticomplements for all the complements injected, a finding that would tend to support the theory of the multiplicity of complements. In addition, Marshall and Morgenroth actually found in ascitic fluid an anticomplement for at least one of two complements present in guinea-pig serum. These experiments go to show that complements differ in this respect at least : that not all have identical haptophores. Whatever differences between complements exist must be slight; probably the cytophilic group of all are alike. At present the subject has more theoretic than practical importance. In the various diagnostic reactions guinea-pig serum ordinarily furnishes the complement for hemolysin, bacteriolysin, or other cytolysins, and in the therapeutic administration of bacteriolytic serums we are compelled in any case to depend for activation of the amboceptor upon the natural complement in the patient's serum. The Nature and Action of Complement. — The true nature of the complements is unknown. In many respects they bear a resemblance to ferments, and certainly the part they play in the processes of cytolysis suggests a ferment-like activity. They differ from true prqteolytic ferments, such as trypsin, in not digesting the stroma of corpuscles, although recent work by Dick would seem to indicate that proteolysis actually occurs, a process that increases the permeability of the cell and permits the escape of hemoglobin. On the other hand, it is possible that the nature and action of complements may be placed upon a chemical basis. Following the discovery of the hemolytic power of cobra venom by Flexner and Noguchi, a power they ascribed to the presence of an amboceptor in the venom acting with serum complement, Kyes found that the amboceptor may be activated not only by a complement in the blood-serum, but also by some constituent of the red blood-corpuscles themselves. This last observer speaks of the latter as endocomplement, i. e., endocellular complement. In attempting to discover the nature of this endocomplement various substances existing normally in the erythrocytes, such as cholesterin and lecithin, were obtained in a pure state and their activating powers for cobra amboceptors tested. These investigations showed that lecithin has an activating power, whereas cholesterin is antihemolytic. Although all erythrocytes contain lecithin, yet all are not equally susceptible to the action of venom amboceptors, which is probably due to the fact that the lecithin in the cells of some animals is bound to other cell constituents in a loose way and is thus available as complement. In syphilitic infection the lecithin content of the erythrocytes is actually diminished or in some manner rendered less available, so that the inhibition or absence of venom hemolysis is diagnostic of this infection. Kyes was able to obtain the union of cobra amboceptor and lecithin, forming what is known as cobra ledihid. Although lecithin is an unstable substance and is difficult to obtain free from fatty acids and soap, there is little doubt but that Kyes' lecithid is a phosphatid compound and is actively hemolytic after all traces of fatty acids have been removed. The next important observations were made by Noguchi,1 who found that soap isolated from blood and various tissues possessed active hemolytic properties. The salts of the fatty acids, and particularly of oleic acid, were found to possess similar hemolytic properties. Pure soluble oleates mixed with serum were found to produce compounds possessing many of the characteristics of true complements: (1) They are inactivated by heating to 56° C. for half an hour; (2) they are inactive at 0° C.; (3) the addition of acids, alkalis, and yeast renders them inactive. 1 Proc. Soc. Exper. Biol. and Med., 1907, 4, 107; Biochem. Zeitschr., 1907, 6. Von Liebermann,1 as the result of his own experiments, came to practically the same conclusions, and advanced the hypothesis that the complements of the blood are to be sought for in the soaps of the serum; that these soaps are united with serum albumin, and are inactive until liberated by the amboceptors, when they become actively hemolytic. Further than this, it was shown that oleic acid may act as an amboceptor, and when added to an inactive soap-albumin combination, it would render this actively hemolytic. Von Liebermann and Fenyvessy2 have shown that a mixture of soap, serum, and oleic acid possesses a striking resemblance to complements and amboceptors, and that the amboceptor-complement action is much more than a mere linkage of complement to antigen by means of an amboceptor. These observers suggest that an amboceptor may have an affinity for certain constituents of the cell or bacterial body, and, on the other hand, act upon the complement and separate one of its constituents, which then breaks up the cell. These artificial hemolysins, however, completely dissolve the stroma of the corpuscles, whereas the immune hemolysins appear to dissolve out the hemoglobin, leaving the stroma undissolved. As has been mentioned elsewhere, recent work would tend to show that the stroma is also dissolved, at least in part, in specific hemolysis, so that the difference in action between the two is not quite so apparent. While the simplicity of the substances concerned in these observations does not harmonize with the great variety and complexity of the immune bodies, nevertheless, as Adami has pointed out, the points of resemblance between artificial and natural complements and amboceptor are so striking that material advances in our knowledge of their nature and action may be gained by further researches into the chemistry of immunity. Complement Splitting. — During recent years considerable attention has been directed toward a phenomenon known as the splitting of complement. It was generally conceded that when treated with hydrochloric acid (Sachs), carbon dioxid gas (Liefmann), or acid and alkaline phosphates (Michaelis and Skwissky), or when dialyzed against distilled water (Ferrata), complement may be split into two parts, known as a mid-piece and an end-piece. According to certain investigators, these two components of the complement differ in their behavior in hemolytic processes: one, the mid-piece, is bound by the sensitized cells, while the other, or end-piece, possesses the lytic action. Speaking in terms of the side-chain theory, it is just as if the haptophore and cytophilic portions of the complement were separated: the haptophore portion corresponding to the mid-piece (the cell or bacterium being the first piece), and the lytic cytophilic portion corresponding to the end-piece. In successful complement splitting the mid-piece is believed to be in the globulin fraction and the end-piece in the albumin fraction. Noguchi and Bronfenbrenner1 have cast considerable doubt upon these views, and have shown that what is known as complement splitting is really nothing more than an inactivation of the active principle of complement, since both globulin and albumin fractions contain a part of the complement, a fact that can be demonstrated by the removal of the inhibiting action of the acid or alkali used in the process. In the endeavor to demonstrate the unity of complement Bordet and Gengou devised an experiment that has proved of great practical value in the serum diagnosis of syphilis and other infectious diseases. By mixing bacteria and their amboceptors with a little fresh serum containing complement and letting the mixture stand aside for an hour or so it was found that, upon the addition of corpuscles and their amboceptor, hemolysis did not occur, although the serum that had been used as complement was capable, in its original condition, of producing hemolysis of these corpuscles. Bordet advanced this experiment to show that the complement concerned in bacteriolysis is the same as that at work in hemolysis, and consequently concluded that there is but one single complement. This experiment of Bordet is usually spoken of as the "BordetGengou phenomenon," and is now used extensively in determining whether or not a given serum contains certain amboceptors. The serum to be tested is first inactivated, treated with the antigen composed of an emulsion of the bacterium whose amboceptor it is desired to discover, and then mixed with a small quantity of a fresh normal complement serum. The mixture is placed in the incubator for an hour, during which time the bacterial antigen unites with its amboceptor and the complement, i. e., fixes the complement, so that when red blood-cells previously sensitized with heated hemolytic serum are added, hemolysis does not occur because the complement in the fresh serum, which was suitable for lysis of the sensitized corpuscles, has been "fixed" by the bacteria by reason of the presence of specific amboceptors in the serum tested (Fig. 97). If these amboceptors were not present, then the complement would remain unfixed and be free to hemolyze the sensitized corpuscles, a negative reaction being indicated, therefore, by hemolysis, whereas the absence or inhibition of hemolysis indicates a positive reaction. Tube 1 shows the hemolytic system; C, a red blood-corpuscle; A, a hemolytic amboceptor; Cp, complement; C.A.C., complement united to a corpuscle by means of the specific amboceptor. Hemolysis results. Tube 2 shows complement fixation by bacterial antigen and amboceptor; Ai antigen; C, complement united to the antigen A\ by the amboceptor A. When hemolytic amboceptors are added hemolysis does not occur because the complement has been previously fixed by the bacterial antigen and amboceptor. Tube 3 shows absence of complement fixation because the bacterial amboceptor Ai is not specific for the bacterial antigen A2 and hence complement is not fixed; when hemolytic amboceptor and the corresponding corpuscles are added complement unites with these, C.A.C. and hemolysis occurs. Deviation or Deflection of Complement. — While large doses of antitoxin are indicated in the treatment of diphtheria and tetanus, theoretically the administration of too large an amount of a bacteriolytic serum may result in more harm than good. As has been pointed out by Neisser and Wechsberg, more amboceptors may be introduced than can be taken up by the bacteria causing the infection, and those that remain free are capable of combining with some of the complement that is present, and thus prevent a portion of the complement from acting with the amboceptors attached to the bacteria — i. e., the complement has been deviated or deflected from its natural course. This would really mean a decrease in bacteriolysis, but while deviation of complement has been demonstrated as a fact, its importance in serum therapy is probably overrated and has certainly not been definitely proved. QUANTITATIVE TITRATION OF Titration of Hemolytic Complement. — The quantity of a hemolytic complement present in a fresh serum for certain corpuscles may be measured in the same manner as hemolytic amboceptors are measured, namely, by adding to a series of test-tubes increasing amounts of the fresh serum with a constant dose of an emulsion of corpuscles and a constant and sufficient dose of the corresponding hemolytic amboceptor for these corpuscles. After a suitable period of incubation, that tube that shows complete hemolysis contains just sufficient complement, or one unit. Since we know how much complement serum was placed in this tube, we now know that this quantity contains one unit of hemolytic complement. Of course, the amount of corpuscles and amboceptor must be constant in all tubes; if the quantity or quality of one or both of these is altered, the unit of complement will vary. Titration of a Bacteriolytic Complement. — The quantity of bacteriolytic complement in a given amount of fresh serum may be determined in a similar manner, although far less accurately, for instead of viewing the results of lysis in the test-tube as we can do in hemolysis, the degree of lysis must be determined by plating out the mixtures to determine the relative numbers of living and dead bacteria. The degree of bacteriolysis may, however, be viewed after a manner with the aid of the microscope. Gay and Ayer employ a direct method, which consists in adding varying amounts of the serum to be tested to a definite volume (0.5 c.c.) of a suspension of cholera vibrios, prepared by emulsifying a twentyfour-hour agar culture in 10 c.c. of normal salt solution and adding a constant and sufficient dose of serum from a rabbit immunized against cholera. The mixtures are placed in small test-tubes and incubated for one and one-half hours at 37° C. Films are then prepared, stained, and examined to ascertain the degree of changes undergone by the vibrios. Or the changes may be observed in hanging-drop preparations. In either case a control is prepared of the culture which has also been incubated along with the mixtures. Gay and Ayer found that 0.02 c.c. of normal human serum contained sufficient complement to effect complete lysis of this dose of vibrios — even 0.001 c.c. produced distinct changes. HAVING considered the general nature and properties of amboceptors and complements and the mechanism of their action in producing solution or lysis of cells, we will now study more closely the bacteriolysins, which are antibodies belonging to this group and possessing diagnostic and considerable therapeutic importance. Historic. — The early history of the discovery of the bacteriolysins is closely associated with the history of immunity in general, for with the discoveries in bacteriology and the establishment of the relation of bacteria to disease, it followed as a matter of course that investigations should be undertaken to ascertain the mechanism of resistance to and of recovery from an infection. In 1874 Traube showed that sej^ifijiiaterial may be destroyed in the blood of living animals, and in 1881 Lister demonstrated the same phenomenon in extravascular blood. These experiments were naturally somewhat crude, as they antedated the period in which the pyogenic microorganisms were isolated and studied in pure culture, but they served, nevertheless, to demonstrate the germicidal powers of the blood. In 1886 Fodor demonstrated the germicidal action of blood-serum upon anthrax bacilli. This work was followed shortly after by that of Flugge and Nuttall, who showed the germicidal powers of the body-fluids in general independent of cells; The controversy between the adherents of the cellular and humoral theories of immunity now began, as Metchnikoff was actively engaged in studying phagocytes and in formulating his phagocytic theory. Buchner and others took up the subject, emphasizing the important germicidal powers of the body-fluids and ascribing this function to the presence of "alexins" (substances that ward off disease). Buchner showed that if the serum was heated this germicidal power was lost; hence it followed that the active bacteriolytic agent was considered very unstable and was quickly destroyed outside of the body. DEFINITION 359 immunity, and incidentally strengthened the claims of the humoral theory. He showed that cholera vibrios introduced into the peritoneal cavity of a guinea-pig that had been immunized against cholera lost their motility and finally became disintegrated and passed into solution regardless of the presence of cells. It remained for Bordet, however, to show the mechanism of this interesting phenomenon. This observer demonstrated the fact that the thermolabile body was but one substance concerned in the reaction, and that the specific substance was thermostabile and the actual product of immunization, results that were later corroborated and elucidated by his researches upon hemolysis, and by those of Ehrlich and his pupils on cytolytic phenomena in general. As previously mentioned, Bordet retained the name "alexin" for the thermolabile substance and applied the new term, " substance sensibilisatrice," to the specific thermostabile antibody. Later, both substances were renamed by Ehrlich, and called " complement" and "amboceptor" respectively. As will be pointed out further on, as the result of these observations Metchnikoff modified his phagocytic theory, and recognized the existence of both substances, which he named "cytases" and "fixateurs," believing that both were derived from cells classed as phagocytes. All are agreed as to the presence of two different bodies in the bodyfluids concerned in bacteriolysis, although opinions vary as regards their origin and mechanism of action. The side-chain theory has been widely accepted in explanation of their action, and the terms applied by Ehrlich to the two substances concerned, namely, complements and amboceptors, are in general use. The term itself would infer that solution or lysis of the bacterium is an essential property of an antibody of this order. Bactericidins are substances that kill bacteria without lysis, and, strictly speaking, an effort should be made to differentiate between the terms, although from a practical standpoint this is not important. Certain microorganisms may be killed and resist solution or digestion for a comparatively long time, whereas, on the other hand, the same bacteria, under different circumstances, may readily be lysed. Although the endotoxins liberated from the lysed bacteria may produce symptoms of disease, followed by death, yet the bacterium itself is usually destroyed and unable to proliferate. A bacteriolysin is, therefore, always bactericidal, although the converse is not necessarily true. 360 BACTERIOLYSINS Custom, however, has never strictly differentiated between the two terms, and bacteriolysis appears to be but a continuation of and a more nearly complete bactericidal process. Hence the definition just given covers both terms — bacteriolysins and bactericidins. Origin of Bacteriolysins. — Our knowledge regarding the origin of the bacteriolysins is quite fragmentary. The investigations of Pfeiffer and Marx in cholera, and Wassermann in typhoid, have shown that the spleen and hematopoietic organs in general may be especially concerned. According to Metchnikoff, the "bacterial fixateurs," which are practically the bacteriolysins, are secretory or excretory products of phagocytic cells, especially the polynuclear leukocytes or microphages. It is commonly believed that during infection the bacteria cause phagolysis or disintegration of these cells, with liberation of both complements (cytases) and amboceptors (fixateurs), which produce extracellular lysis of the invading bacterium (bacteriolysis). If, on the other hand, the phagocytes are fortified and phagolysis is prevented, the bacteria are phagocytized and undergo intracellular lysis, a condition that, according to Metchnikoff, may be induced experimentally by giving an animal an intraperitoneal injection of sterile bouillon twenty-four hours before bacteria or other cells are injected. That leukocytes afford a bacteriolytic substance is supported by observations showing that leukocytic exudates, secured by the injection of a sterile aleuronat suspension, possess a well-marked germicidal activity. Issaeff found that the intraperitoneal injection of sterile bouillon and other mild irritants, by producing a leukocytic exudate that supplied certain bactericidal substances and facilitated phagocytosis, increased the resistance of animals to bacterial infection. At one time surgeons made practical use of this observation by injecting nucleinic acid and other substances into the peritoneal cavity before performing laparotomy, in order to induce a local resistance to a possible infection. LEUKINS AND LEUKOCYTIC EXTRACTS The bactericidal substance contained within leukocytes has been extensively studied by Schattenfroh, Schneider, Peterson, Hiss and Zinsser, Manwaring, and others. It has been observed that when leukocytes are suspended in diluted blood-serum, the bactericidal properties of the serum are increased without coincident destruction of the cells, showing that the leukocytes may secrete germicidal substances into the fluid. The same observation has been made with Bier's congestive and in living tissues. Hiss, and later Hiss and Zinsser, found that autolyzed leukocytic exudates possess some bactericidal activity, and that they may profoundly modify experimentally induced infection of rabbits and guineapigs with the pneumococcus, staphylococcus, streptococcus, and other bacteria. In applying this method of treatment to man by means of subcutaneous injections, these investigators observed distinctly beneficial results in cases of epidemic cerebrospinal meningitis, lobar pneumonia, staphylococcus infections, and erysipelas. Preparation of Leukocytic Extracts. — Hiss and Zinsser have prepared leukocytic extract by giving rabbits intrapleural injections of aleuronat suspension. Manwaring has secured much larger quantities by making his injections into the horse. The aleuronat is prepared by making a 3 per cent, solution of starch in bouillon without heating, and adding 5 per cent, of powdered aleuronat to this emulsion. The starch helps to keep the aleuronat in suspension. The mixture is boiled for five minutes and placed in large sterile testtubes, 20 c.c. being placed in each tube. Final sterilization is done in an autoclave. For making the injections large rabbits are selected. The hair over both sides of the thorax is removed, the skin is sterilized with tincture of iodin, and 10 c.c. of the aleuronat suspension are injected into each pleura! cavity at a point in the anterior axillary line, at the level of the sternum, great care being taken to avoid puncturing the lungs. After twenty-four hours the animals are chloroformed and the pleural cavities carefully and aseptically opened. The cellular exudate is pipeted into centrifuge tubes containing at least 10 c.c. of sterile 1 per cent, sodium citrate in normal salt solution. One or more cubic centimeters of exudate may be obtained from each cavity. The exudate is usually tinged with blood. It is then centrifuged and the supernatant fluid removed. The sediment is broken up with a platinum spatula, and 20 volumes of sterile distilled water are added. The tubes are set aside in the incubator for twenty-four hours, after which cultures are made to insure sterility. A small amount of preservative may be added, and the extract placed in bottles or ampules ready for administration. It is given subcutaneously in doses of from 5 to 10 c.c. every four to six hours. The endocellular bactericidal substances, or endolysins, mentioned in a previous chapter, which can be extracted from leukocytes, are not in the nature of complements, as they are not rendered inactive by tern- peratures below 80° C. They cannot apparently be increased by immunization, the quantity present in each leukocyte being probably at all times just sufficient for the digestion of a limited number of bacteria, which can be ingested at one time by the individual leukocyte. It is probable that the excess of bactericidal substance is thrown off into the blood-stream, representing the serum bacteriolysins, and. at least indicating that the leukocytes are one source for the production of bacteriolytic amboceptors. Mechanism of Bacteriolysis. — According to the side-chain theory of Ehrlich a bacteriolysin is an antibody of the third order, or an amboceptor furnished with two haptophore or grasping arms for uniting the bacterium on one side with a suitable complement on the other. The antibody, therefore, acts simply as an interbody or connecting link; it is specific for the bacterium causing its production, but is unable itself directly to injure the bacterium, lysis being brought about by an at- tached complement. Bacteriolysis is, therefore, an interaction of ambocep-tor and complement upon the bacterial serum may not be active in all animals. The influence of bacteriolysins upon endotoxins is a question of considerable interest and importance. As the result of convincing experiments performed, especially by Pfeiffer, it is evident that a bacteriolytic serum does not neutralize the endotoxin at the time the bacterium undergoes disintegration. Highly immune serums appear to be unable to protect an animal against the endotoxins, and, indeed, may even increase the intoxication and, by liberating an excess of endotoxin, kill the animal. The bactericidal substances derived from leukocytes are, however, apparently capable of neutralizing endotoxins, to some extent at least, as Hiss and Zinsser were unable to ascribe the beneficial effects of leukocytic extracts to the bacteriolytic action alone. As mentioned elsewhere, both Metchnikoff and Bordet maintain that the bacteriolysin is in the nature of a "sensitizer," preparing the bacterium for the action of the alexin or cytase, just as a mordant aids in the penetration of a dye-stuff. General Properties of Bacteriolysins. — As with other cytolysins, the bacteriolysins are thermostabile and resist heating to 60° C., being gradually destroyed at temperatures ranging from 70° to 80° C. They are likewise highly resistant to acids and alkalis, and when preserved in a sterile condition with the addition of small quantities of a preservative bacteriolytic serums for therapeutic and diagnostic purposes may remain active for long periods of time. Cholera immune serum as a diagnostic aid in making the agglutination and Pfeiffer bacteriolytic reactions is best preserved in dry form, the serum retaining its activity under these conditions for considerable periods of time. Normal Bacteriolysins. — As a result of the contention of Metchnikoff that bacteriolysins (fixateurs) are produced only upon the disintegration of leukocytes, and that the plasma is accordingly free from these antibodies, much experimental work has been done. The weight of evidence is against this view, as both amboceptors and complements have been demonstrated in plasma, although the quantity of bacterial amboceptors normally present in the body-fluids is quite small. It is quite natural to expect that under normal conditions small amounts will be present, as receptors are being constantly thrown off into the blood, and leukocytes are, of course, being constantly formed and destroyed. Specificity of Bacteriolysins. — The bacteriolysins are highly specific antibodies, and are useful in making the differentiation of bacterial species. Group bacteriolytic reactions are less common as compared to group agglutination, as was shown by Kolmer, Williams, and Raiziss with the typhoid-colon group of bacilli. As a practical procedure, however, the agglutination reaction is so easily secured as to be the test of choice in making a differentiation between closely allied organisms. As with the agglutinins, the influence of partial bacteriolysins may be removed by using highly immune serums in high dilutions . THE PFEIFFER EXPERIMENTS The essentials of this important test have been described at the beginning of this chapter. Briefly, it consists in making intraperitongaL injections of a bacteriolytic serum mixed with living bacteria into a normaljguinea-pig. The resulting bacteriolysis is studied microscopically by withdrawing small amounts of peritoneal exudate at varying intervals. By performing the experiment with varying dilutions of serum, the bacteriolytic titer may be determined by noting the dilution in which bacteriolysis just fails to occur in a specified time. Pfeiffer also showed that the phenomenon could be produced by injecting a mixture of serum from an immunized animal and the culture of cholera into the peritoneum of a normal guinea-pig. This phenomenon appeared when an old specimen of serum was used, as well as when a fresh specimen that had been heated to 60° C. was employed. Later, this observer found that if an old immune serum was injected into the peritoneal cavity and allowed to remain for a time, it regained its bactericidal powers. Pfeiffer believed that the bacteriolytic substance may exist in the serum of jin immunized animal either in an active or in an inert state. In the blood-serum or peritoneal fluid of the living animal it occurs as an active substance, but when kept for a few days or when heated rapidly to 60° C. it becomes inert; it maybe rendered active again by coming in contact with the lining endothelial cells of the peritoneum. The foregoing constitutes the classic Pfeiffer experiment. The bacteriolytic amboceptor present in the immune serum is activated by the complement furnished by the guinea-pig.. The same serum will not produce bacteriolysis in the test-tube in case it has been heated or the complement is lost through age unless iresh normal serum or peritoneal exudate is added. By immunizing guinea-pigs with gradually increasing doses of cholera serum and then introducing fatal doses of cholera culture intraperitoneally, the same phenomenon of bacteriolysis is observed. In this instance the guinea-pig furnishes both amboceptor and complement. By these and similar experiments and observations Bordet was able to show the role played by the two bodies concerned in cytplysis in general, namely, the vthermolabile alexin or complement and the specific sensitizer or bacteriolytic amboceptor. TECHNIC OF BACTERIOLYTIC TESTS 365 Bacteriolytic Test in vivo for the Identification of Bacteria Recovered from Feces, Water-supplies, etc. — This method is employed chiefly in the identification of suspected cholera cultures. According to Citron, in Germany, the Pfeiffer test, made with microorganisms obtained in pure culture from suspected patients, is required for the official diagnosis of the first cases of cholera. easily carried out. This bacteriolytic test may also be employed in the study of typhoid and paratyphoid bacilli, although bacteriolysis of these microorganisms is less complete than that observed with cholera, and agglutination tests answer all practical requirements. The test consists in mixing varying dilutions of a known and highly immune serum with a constant dose of unknown microorganisms, and injecting the mixtures intraperitoneally into guinea-pigs. After twenty minutes small amounts of exudate are withdrawn by means of fine capillary pipets, and studied in hanging-drop preparations. In the presence of a positive reaction the bacilli are observed to lose motility, become swollen and coccoid in shape, and gradually form granules, ultimately disappearing in complete solution. Preparing the Immune Serum. — A highly immune serum is required. This may readily be prepared by giving rabbits a series of intravenous injections of a known culture, according to the technic described in the chapter on Active Immunization of Animals. The official test in Germany demands that the serum be of such strength that 0.0002 gram of dried serum will suffice to disintegrate completely within one hour one loopful (2 mg.) of an eighteen-hour-old culture of virulent cholera in 1 c.c. of nutrient bouillon when injected into the peritoneal cavity of a guinea-pig. The Hygienic Laboratory1 in Washington is prepared to furnish board of health laboratories with a dried serum of high titer for diagnostic purposes. In testing an immune serum to determine its bacteriolytic titer the dose of microorganisms should not be larger than one loopful, so that if any particular strain of cholera or typhoid is not sufficiently virulent, necessitating the use of larger doses, the virulence should be increased by passing the organism through guinea-pigs. Method of Testing the Virulence of a Culture. — The unit of measurement is a 2 millimeter platinum loop, which, when loaded, will usually 1 Personal communication from Dr. John F. Anderson. hold about 2 milligrams of microorganisms. (See p. 216.) All dilutions are made with sterile neutral broth, and not with salt solution. Mixtures are injected intraperitoneally into 250-gram guinea-pigs to determine the dose that will be fatal within twenty-four hours. Great care should be exercised in all manipulations to avoid accidental infection. The mouth-ends of pipets should be plugged with cotton. Sufficient assistants should be on hand to facilitate the making of injections and the examination of peritoneal exudates with ease, caution, and certainty. All pipets, measuring glasses, test-tubes, and hanging-drop preparations should be immersed after using in 1 per cent, formalin solution before cleaning. In other words, every precaution should be taken to carry out a thorough and conscientious bacteriologic Jechnic. A satisfactory culture is one in which a dose of £ loopful will prove fatal within twenty-four hours. The immune serum is then titrated with five times this amount of culture, or one loopful. Method of Titrating a Bacteriolytic Serum. — The serum is inactivated by heating to 56° C. for half an hour, and dilutions are made with bouillon in sterile shallow glasses or test-tubes. One loopful of an eighteen-hour agar culture of the microorganism is thoroughly emulsified—, jn the diluted serum, and the mixtures are injected intraperitoneally in 250-gram guinea-pigs. Higher dilutions than those given here may be employed until the limit of bacteriolytic activity is reached. 1. Mix 0.5 c.c. of inactivated serum with 4.5 c.c. of bouillon (1 : 10). Place 2 c.c. of this mixture in a separate test-tube, and add 2 loopfuls of culture. Inject 1 c.c. ( = 0.1 c.c. immune serum). 2. Mix 2 c.c. of the first dilution (1 : 10) with 18 c.c. of bouillon ( = 1 : 100). Place 2 c.c. in a separate tube and add 2 loopfuls of culture. Inject 1 c.c. ( = 0.01 c.c. immune serum). 3. Mix 1 c.c. of the second dilution (1 : 100) with 4 c.c. of bouillon ( = 1 : 500). Place 2 c.c. in a separate tube and add 2 loopfuls of culture. Inject 1 c.c. ( = 0.05 c.c. immune serum). 4. Mix 2 c.c. of the third dilution (1 : 500) with 2 c.c. of bouillon (= 1 : 1000). Place 2 c.c. in a separate tube and add 2 loopfuls of culture. Inject 1 c.c. ( = 0.001 c.c. immune serum). 5. To 1 c.c. of the fourth dilution (1 : 1000) add 9 c.c. of bouillon (=1 : 10,000). Place 2 c.c. in a separate tube, and add 2 loopfuls of culture. Inject 1 c.c. ( = 0.0001 c.c. immune serum). 7. Control: To 2 c.c. of a 1 : 10 dilution of inactivated normal rabbit serum add 2 loopfuls of culture and inject 1 c.c. intraperitoneally. If goats or horses are used in preparing the immune serum, this control should be conducted with normal goat or horse serum. According to Kolle, one loopful of virulent cholera culture is destroyed in the peritoneal cavity of a guinea-pig by 0.1 to 0.3 c.c. of normal rabbit's serum; 0.02 to 0.03 c.c. of normal goat's serum; 0.005 to 0.01 c.c. of normal horse's serum. 8. Control: A pig may be injected with 1 c.c. of a 1 : 100 dilution of the immune serum, and with a loopful of some other microorganism, such as Bacillus coli. This control, however, is not absolutely necessary. An area of the abdominal wall of the guinea-pig about one inch in diameter is shaved and cleansed with alcohol. After the injections have been made the bacteriolytic phenomena are observed. withdrawing the peritoneal exudate. After permitting the animal to inhale a few drops of ether, to make sure that it will not suffer, a small incision is made through the skin of the abdomen. The capillary pipet, the large end of which is kept closed with the index finger, is then quickly passed into the abdominal cavity. The index-finger is released, and the tube is gently moved about and withdrawn. As the result of capillary attraction sufficient exudate usually passes into the tube without the aid of suction (Fig. 99). The tube may be fitted with a rubber teat in case suction should be necessary. Hanging-drop and smear preparations are made and studied microscopically (Fig. 100). Stained smears are, however, less reliable and not so useful in determining the degree of bacteriolysis (Fig. 102). bacteriolysis in the exudate (Fig. 101). A smear of the culture stained with dilute carbolfuchsin should also be on hand for making comparison with smears of the exudate (Fig. 103). ^JBacteriolysis is first manifested by loss of motility. As the process progresses many of the bacilli become swollen and distorted, and later irregular and broken fragments or granules become apparent. Finally, at the end of an hour, the exudate is practically sterile. In those cases in which bacteriolysis is complete in an hour the animal generally sur- means of a pipet. vives. In the higher dilutions of serum bacteriolysis is incomplete, and the animal becomes toxic and may succumb after twenty-four hours, double the virulent dose being used in all injections. In the foregoing titration a serum that is bacteriolytic in dilutions of 1 : 1000 or over will be satisfactory for purposes of diagnosis. When preserved in a sterile condition in separate ampules in a dark cold place the titer usually remains unaltered for several months. process of drying the amboceptor content may be decreased. Dried serum is to be preferred, however, as it keeps much longer and there is no danger of rendering it worthless by contamination. After drying, the product is ground in a mortar and stored in amounts of 0.1 or 0.2 gram in separate ampules. In determining the bacteriolytic titer of dried serum 0.1 gram is carefully weighed out and dissolved in 9.9 c.c. of sterile bouillon. From this stock dilution other dilutions may be prepared, in the manner previously described, and injected with a loopful of the culture. TIVE PFEIFFER REACTION. A hanging drop of peritoneal exudate removed from a guinea-pig one-half hour after injection with 1 c.c. of the suspension shown in Fig. 101 with 1 c.c. of 1 : 1000 dilution of cholera immune serum. Note that the bacilli are now quite short and coccoid in shape. At the end of seventy minutes .the exudate was sterile. What appears to be two or three coccoid forms in apposition is really one bacillus undergoing lysis. FORE BACTERIOLYSIS. X 720. A hanging drop of cholera in normal salt solution prepared from a twentyfour-hour culture of cholera on agaragar. bacteria taking place. Technic of the Pfeiffer Test. — The suspected culture to be tested should be grown on agar for from eighteen to twenty-four hours, and used in doses of one loopful (2 mg.). of each dilution, representing 2, 5, and 10 times the titer dose, are placed in separate glasses or small test-tubes. A fourth tube should contain 2 c.c. of a 1 : 100 dilution of normal serum, according to the animal used in producing the immune serum; a fifth tube should contain 2 c.c. of sterile bouillon (culture control). Two loopfuls of suspected culture are thoroughly emulsified in each of the five tubes of the series, and 1 c.c. of each is injected intraperitoneally in five guinea-pigs weighing about 250 grams each. At intervals of ten, twenty, forty, and sixty minutes the peritoneal exudate should be removed with capillary pipets and examined in hanging-drop preparations. Smears may be prepared and stained with dilute carbolfuchsin, although they give less information than hanging-drop preparations. If guinea-pigs Nos. 1, 2, and 3 show granule formation at the latest after an hour, while in the fourth and fifth animals the bacteria remain whole, motile, and well preserved, the reaction may be regarded as positive and the diagnosis as established. Pfeiffer Bacteriolytic Test in vivo in the Diagnosis of Disease. — Bacteriolysins are usually produced somewhat later than agglutinins, and reach their highest point of production during convalescence. Bacteriolytic tests are used only for diagnostic purposes, when agglutination reactions are negative or doubtful. The most satisfactory results from these tests are obtained in cholera. Bacteriolysis with typhoid bacilli is less typical and more incomplete; with the paratyphoid and dysentery bacilli it is even more unsatisfactory, and in anthrax, pest, and the various diseases due to cocci it does not occur. The test is conducted in a manner similar to the preceding test, except that instead of an immune serum the patient's serum is used, with a known culture of typhoid, cholera, paratyphoid, etc., according to the infection suspected to be present. One cubic centimeter of the patient's serum is secured in a sterile manner, inactivated by heating to 55° C. for one-half hour, and dilutions of 1 : 20, 1 : 100, 1 : 250, and 1 : 500 prepared with sterile bouillon. Two cubic centimeters of these dilutions are placed in separate tubes, and two loopfuls of an eighteen-hour culture of the test organism emulsified in each. A fifth tube contains 2 c.c. of bouillon with two loopfuls of culture, and serves as the culture control. One cubic centimeter of each dilution and of the culture control is injected intraperitoneally into five guinea-pigs, and the exudate examined after twenty, forty, and sixty minutes. If granule formation occurs in the first two or three animals, but is absent in the culture control, the reaction may be regarded as positive, and the diagnosis of typhoid, cholera, etc., considered as established. Measuring the Bactericidal Power of the Blood in vitro by the Plate Culture Method (Stern and Korte). — Since the earliest days of bacteriology the aim and purpose have been to devise some means by which the bactericidal power of the blood could be measured, just as is done in testing an ordinary germicidal substance, namely, by adding a bacterial suspension to the serum and observing the effect on the bacterial content. This is shown by counting the bacteria in a loopful immediately after adding the bacterial suspension, and repeating this at regular intervals, the counting being done by the method of plate culture. The use of the platinum loop in these tests is objectionable, since the dose is quite variable, depending upon whether the loopful is removed from the fluid edgewise, or with the loop held flat, like a spoon in use. If the serum contains agglutinins, the results with any form of technic are likely to be irregular, and the number of colonies upon the plate stand in no relation to the actual number of microorganisms present. The results may be masked by a rapid multiplication of the survivors, and accordingly several controls are necessary with any technic. Neisser and Wechsberg have recommended the so-called bactericidal plate culture method. By this method the patient's serum is inactivated, and varying amounts mixed with definite and constant quantities of bacteria. To this a constant quantity of active normal serum is added as complement, to reactivate the bacteriolytic amboceptors. These mixtures are then incubated for several hours. To determine whether and in what proportion death of bacteria has resulted from the effect of the bacteriolysins, agar is added, and the mixtures are then plated and incubated for twenty-four hours or longer. The number of colonies are then counted and the results compared with control plates of the culture alone. Stern and Korte have modified this technic slightly, and recommend the procedure as a substitute for the Pfeiffer test in the clinical diagnosis of typhoid fever. The method spares a certain number of animals, but it is somewhat more complicated than the Pfeiffer reaction, and its results are less trustworthy. As a clinical test, therefore, it is to be recommended only in cases in which the agglutination reactions have yielded uncertain results, although with practice and care the test oftentimes as after typhoid immunization. Technic of the Test. — The requisites for success are that all vessels and diluting fluids, as well as the serums employed, should be absolutely sterile. To secure uniform and reliable results it is necessary to familiarize oneself with the technic by repeated practice. In order to carry out the steps in the technic according to strict aseptic bacteriologic principles the services of an assistant are required. One cubic centimeter of sterile patient's serum and an equal amount from a normal and healthy person to serve as a control are inactivated by heating to 55° or 56° C. for half an hour. These serums are then diluted 1 : 50 by adding 49 c.c. of sterile salt solution to each and mixing thoroughly. Complement is prepared by securing 4 to 5 c.c. of sterile rabbit's blood and separating the serum. This serum is chosen because it should be from the same species of animal as that used in producing the immune serum to be tested. In determining the bactericidal titer of human serum either guinea-pig or rabbit complement serum may be used. Dilute 2 c.c. of this fresh serum (not over eighteen hours old) with 18 c.c. of sterile normal salt solution (1 : 10). Dose, 0.5 c.c. Secure a good twenty-four-hour bouillon culture of typhoid bacilli (grown in the incubator) and dilute 1 : 500 by thoroughly mixing 0.1 c.c. of the culture in a flask containing 50 c.c. of sterile normal salt solution. This dilution of culture, when used in constant doses of 0.5 c.c., generally yields satisfactory results, but it may be necessary to try it out beforehand, for the control plates must regularly show a uniformly good growth and contain many thousands of colonies before uniform results can be expected. The bactericidal effect will then be distinctly shown by the reduction, in the proper plates, of this large number of colonies to zero or near it. Place 1 c.c. of sterile neutral bouillon in each of 12 test-tubes which have been plugged with cotton, sterilized, and large enough to hold at least from 12 to 15 c.c. Place in the first of these tubes 1 c.c. of the diluted patient's serum and mix thoroughly by alternate sucking up and forcing out of the fluid; then, with the same pipet, draw up 1 c.c. and transfer it to the second tube of the series; mix as before, and transfer 1 c.c. to the third tube; continue in this manner to the last tube, from which, finally, 1 c.c. is discarded. Each tube now contains 1 c.c. of fluid, representing dilutions of 1 : 100, 1 : 200, 1 : 400, 1 : 800, 1 : 1600, 1 : 3200, and so on up to 1 : 204,800 of the patient's serum. Higher or lower dilutions than these may be employed. It is very desirable that the dilutions be high enough to secure the limit of bactericidal activity, so that the last plates will show an increase in the number of colonies. 1 : 200, 1 : 400, and 1 : 800. Label each tube carefully with the initials of the patient and the dilution it contains. Add 0.5 c.c. of the diluted bacterial emulsion, and finally 0.5 c.c. of the diluted complement serum, to each tube. All manipulations should be made with strict bacteriologic care and with the aid of an assistant, as the introduction of contaminating microorganisms that may cause spore-formation will considerably vitiate the value of the test. neutral agar cooled to 42° C. and thoroughly mixed. This control will show the original number of bacteria contained in the emulsion. Mark as control No. 1. After three hours' incubation this tube receives the usual amount of agar and is plated. It will show to what degree the culture has multiplied in the incubator. 3. Since the complement serum frequently contains bacteriolysin, it is necessary to control this element carefully. To a series of four tubes add the following doses of the serum, diluted 1 : 10: 1 c.c., 0.5 c.c., 0.2 c.c. ,0.1 c.c. Add 0.5 c.c. culture to each tube, and sufficient bouillon to make the total volume in each tube 2 c.c. All tubes with the exception of the first control which has been plated are placed in an incubator at 37° C. for three hours. At the end of this time the contents of each tube are plated in neutral agar. Sterile Petri dishes should be properly and plainly labeled with a wax-pencil and arranged in order. A flask of plain neutral agar is melted in boiling water and cooled to 42° C. The tubes are removed from the incubator and shaken gently and with the aid of an assistant from 5 to 8 c.c. of agar are added carefully to each tube with a sterile 10 c.c. pipet. The contents are mixed by gentle rotation of the tube and then poured in the corresponding Petri dish, followed by an additional mixing according to the usual bacteriologic procedure. With ordinary speed the whole set of tubes may be poured in a satisfactory manner before the flask of agar has had time to harden. Another method of plating consists in pipeting the contents of each tube into its corresponding dish, and then washing the tube with an additional 1 c.c. of sterile salt solution, to remove all traces of serum and culture. Or the end of each tube may be flamed and the contents poured directly into a dish. If this method is adopted, small test-tubes should be used. While the method is more convenient, it is usually not so accurate as the first two methods. Neisser plates but 5 or 10 drops from each tube. The dose decided upon is the one employed throughout. For example, it would be erroneous to take 5 drops from one tube and 10 from another. Neisser, however, uses much smaller amounts of the serum, as 1, 0.3, 0.1, 0.03, and 0.01 c.c., instead of the much higher dilutions given in this technic. These differences must be remembered and the proper dilutions employed, and but 5 to 10 drops should be plated in performing the bactericidal plate test according to Neisser 's technic. Topfer and Jaffe pour a thin layer of agar into a Petri dish and allow it to harden. Upon this they pour the culture-serum agar mixture, which, after settling, is covered with another thin layer of agar. In this way a culture in the water of condensation is avoided. In the usual technic this may be avoided by turning the plates over soon after hardening occurs so that the water of condensation collects on the cover. All plates are incubated at 37° C., for from twenty-four to thirty-six hours and the colonies then counted. In some plates the number may be so large that counting will be inaccurate and unnecessary. Significance can be attached only to marked and easily recognizable differences. According to Neisser, the growth is best and most rapidly described by means of approximate estimates, using a scheme somewhat like the following: 0 or almost none; about 100; several hundreds; thousands; very many thousands; infinite numbers. A distinct bactericidal action is then present only if the controls react normally, and if a reduction of colonies from an infinite number or many thousands to 0 or very few has occurred. As previously stated, the test can then be regarded as satisfactory only if the lower limits of bactericidal activity have been reached and the last plates show an increase in the number of colonies. Examination of these plates is very much facilitated by using a colony counter, that of Stewart being particularly serviceable with agar plates. Control 2: 0.5 c.c. culture plated after being incubated three hours: plate very crowded; number of bacteria increased. Control 3: Varying amounts of normal rabbit serum used as complement. The first plate containing 0.1 c.c. serum showed a slight bactericidal action; the remaining plates showed many thousand of colonies and were comparable to control No. 1. Control 4: 0.5 c.c. complement serum: sterile. Control 5: 0.01 c.c. inactivated immune serum: sterile. Control 6: 0.01 c.c. inactivated normal control serum: plate shows many thousands of colonies. An examination of this experiment shows that the dose of culture was satisfactory, that the culture increased during the three hours of primary incubation, that the complement serum was very slightly bactericidal in a dose lower than that used in making the test, and that the technic was fairly satisfactory, slight contamination being present in but one plate — that of the inactivated normal control serum. The most striking result observed is the absence of bactericidal activity in the first two plates, which contained the largest amount of immune serum and where one would naturally expect to find complete sterility. The titer of this serum was between 1 : 3200 and 1 : 6400. According to Neisser and Wechsberg, these paradoxic results are caused by deviation or " deflection of complement," as was explained in a previous chapter. In bactericidal experiments, according to Neisser, the deflection is caused by an excess of amboceptors in the immune serum. In a mixture of bacteria, complements, and large amounts of amboceptor the complement is bound not only by the amboceptors anchored to the bacteria, but also in large measure by "free" amboceptors that are not anchored to bacteria. A portion of the anchored amboceptor, therefore, finds no complement at its disposal, and is, therefore, unable to exert any bactericidal action, which gives rise to a relative lack of complement. This phenomenon resembles the action of agglutinoids in the agglutination reaction, where, in the lowest dilutions, agglutination is feeble or absent, but becomes manifest in the higher dilutions. In the foregoing experiment the immune serum used was several weeks old; perfectly fresh serums are not so likely to show this so-called " deflection of complement." In many instances, and especially if a fresh serum is used, one cannot help thinking that agglutinins may be responsible for the absence or diminution of bactericidal activity in the lower dilutions. It is certainly true that hemagglutinins considerably inhibit hemolysis, and this is especially the case with serums of low hemolytic activity. With more potent serums the agglutinins are diluted until activity ceases and hemolysis is ready and complete. Reasoning from analogy, therefore, the absence or diminution of bactericidal activity may be due to agglutinins, and the theory of " deflection of complements" may be emphasized a little too strongly. According to Halm, normal human serums show bactericidal activity in only about one-third of the cases, and the titer is only very exceptionally demonstrable in dilutions higher than 1 : 500. The serums of advanced cases of typhoid fever or of those but recently recovered are bactericidal in dilutions greater than 1 : 1000, and may reach 1 : 50,000 or higher. Similarly after typhoid immunization the patient's serum may show a high bactericidal titer. Weston has found such serums active in dilutions of 1 : 20,000, higher dilutions not being used. Besides being used in typhoid, the plate culture method has been employed for experimental purposes in cholera, dysentery, paratyphoid, and other infections with bacilli of the typhoid-colon group. With these, however, the test possesses but little diagnostic significance. Measuring the Bactericidal Power of the Blood by Capillary Pipet Method (After Wright).1 — By this technic it is sought to overcome the fallacies of the "loopful" method of measurement and those due to agglutination of the test organism. The native complements of the patient's own serum are used; hence the serums used in this technic must be fresh. Quantitative titration is accomplished by furnishing varying dilutions of culture, with a constant quantity of serum. A series of volumes of serum is taken, and to these are added equal quantities of progressively increasing dilutions of a counted bacterial culture. The mixtures are kept at 37° C., for twentyfour hours, after which each is introduced into nutrient broth and cultivated to see whether a complete bactericidal effect has been exerted. able to kill furnishes a measure as to its bactericidal power. After a few technical details have been mastered, this method is quickly performed and yields fairly constant and reliable results. It is not adapted for the titration of old immune serums, but is a ready clinical test, finding a special field of usefulness in determining the bactericidal powers of the blood after typhoid immunization. Requisites for Carrying out the Test. — 1. A specimen of the patient's blood is collected aseptically, a process that may be accomplished by thoroughly cleansing the finger with alcohol and collecting blood in a sterile Wright capsule, or better, perhaps, by means of venipuncture, when from 2 to 5 c.c. may be collected aseptically in a sterile centrifuge tube. The control blood from a healthy individual may be collected in a capsule. The serums are carefully separated and pipeted into small sterile test-tubes; 1 c.c. of each is ample for the test. 2. A twenty-four-hour-old broth culture of the test organism (a young culture is required, because such a culture contains a few dead microorganisms and the absorption of bactericidal elements by dead organisms is thus avoided). tions given in Chapter I. 4. Sterile neutral broth for making dilutions and cultivations. This is prepared and sterilized in the usual manner, from 5 to 10 c.c. being placed in test-tubes. When working with the typhoid bacillus a special broth containing 1 per cent, of mannite and sufficient litmus to color it a deep blue (Smallman) should be on hand. dilutions of the culture. Preparation and Enumeration of the Bacterial Culture. — As the principle of the test depends upon measuring the bactericidal activity of the blood according to the number of organisms that are killed, it is necessary to prepare somewhat high dilutions and count the number of organisms in a unit volume in each dilution. For this purpose place 10 sterile test-tubes in a rack, and arrange 10 sterile Petri dishes on the table to correspond to these. To the first tube add 4.9 c.c. of plain sterile broth; to the second, fourth, sixth, eighth, and tenth tubes add 1 c.c., to the third, fifth, seventh, and ninth tubes, add 4 c.c. FIG. 104.— BACTERICIDAL TEST (LOOPED PIPET METHOD OF WRIGHT). The pipet shown on the extreme left contains the mannite-litmus broth and an equal volume of patient's serum and emulsion of typhoid bacilli; the second pipet shows the serum and bacillary emulsion mixed; the middle pipet shows the serumbacillary mixture cultured in the broth; the fourth pipet shows acid production in the broth by living bacilli which escaped destruction after twenty-four hours' incubation; the fifth pipet (extreme right) is the serum control. The broth, being clear and unchanged, shows that the serum was sterile. solution or hot water. Then, with the same pipet, transfer 1 c.c. to the second tube, mix well, and place 0.1 c.c. in Petri dish No. 2; next transfer 1 c.c. to the third tube, mix, and place 0.1 c.c. in the third Petri dish. Continue in this way until the last tube is reached, when 1 c.c. is discarded into a germicidal solution and 0.1 c.c. placed in the tenth Petri dish. To each Petri dish now add from 8 to 10 c.c. of neutral agar at 41° C., and mix thoroughly. After the plates have hardened they are turned over in order that the water of condensation may collect on the cover. They are then incubated for twenty-four hours, and the colonies carefully counted. We now have the following dilutions of culture : 1 : 50, 1 : 100, 1 : 500, 1 : 1000, 1 : 5000, 1 : 10,000, 1 : 50,000, 1 : 100,000, 1 : 500,000, and 1 : 1,000,000. Since but 0.1 c.c. of these dilutions were plated, the total number of colonies in each plate must be multiplied by 10 in order to obtain the approximate number per cubic centimeter of the various dilutions. To secure fairly uniform results, the various dilutions must be thoroughly mixed and the pipeting be accurately performed. We have found that this method usually gives better results than are obtained by plating but one or two of the higher dilutions, which are used as a basis for calculating the number of bacteria in the other dilutions. Filling the Pipets. — With a wax pencil make a mark upon the capillary stem of a sterile looped pipet at a point 2 cm. from the lower end, and fit a rubber teat to the barrel. The point of the capillary stem is now broken off between the finger and thumb, the lower portion is sterilized in the flame, and the air is expelled from the teat. Mannite broth is then aspirated into the pipet until the bulb is about two-thirds full and the capillary portion contains an air column rising to at least 5 cm. from the end (Fig. 104). reaches the pencil mark. The orifice of the pipet is now raised above the surface of the serum, and a small bubble of air is admitted into the tube, to serve as an index for the measurement. The end of the capillary stem is now carried into the tube containing the highest dilution of the organism, and the culture is allowed to flow in until the bubble of air has been carried just past the pencil mark. The serum and culture must now be mixed, being careful not to contaminate the broth. This is effected by blowing these two volumes out into a sterile mixing tube and drawing up and blowing out the fluid several times in succession. By starting with the highest dilution, the same mixing tube may be used throughout the series. With an airbubble of at least 5 cm. between serum and broth, this can be quite easily achieved without driving the sterile broth down from the bulb of the pipet into the lower part of the capillary stem and contaminating it there. The column of mixed serum and culture is now drawn up into the middle region of the capillary stem and the lower end of the tube is sealed. The teat is then removed, and the dilution that has been used is written on the barrel of the pipet. Controls. — The serum from a healthy individual, or, better still, the pooled serums of several persons, may be used in precisely the same way, with at least the second, fourth, sixth, and eighth dilutions of culture. Several culture controls are advisable. The pipets are filled with mannite broth in the usual manner, and then with one volume of at least four different dilutions, usually 1 : 50, 1 : 5000, 1 : 100,000, and 1 : 1,000,000. The tubes are sealed, labeled, and incubated together with those concerned in the test proper. One pipet is to contain the usual quantity of broth and one volume of the patient's serum. This is a control on the sterility of the patient's serum. A similar preparation is made with the control serum to serve as a control on its sterility. When the whole series of tubes have been filled, these are placed upright in a large test-tube or cylinder labeled with the date and the source of the serum, and incubated at 37° C. for from eighteen to twentyfour hours. Test for the Germicidal Activity of the Serum. — The serum and culture in the capillary portion of the tube must now be mixed with the broth in the barrel. This is accomplished by taking each pipet in hand singly, and heating the lower portion of the capillary stem in a " peep-flame" and drawing out into a small thread with a pair of forceps. A collapsed teat is now fitted over the barrel, and the negative pressure carefully regulated by keeping the finger and thumb in position on the teat, and the finely drawn out end of the capillary stem gently snapped across. The column of serum and culture will then be carried up into the bulb of the pipet. The end of the tube is now sealed. have undergone no color change, but will still be clear. When a growth of the typhoid bacillus has occurred, a perceptible cloudiness will be apparent in the broth, and the color will have changed from blue to reddish-blue, indicating that acid has been formed from the mannite. with the formation of acid. The controls are first examined and recorded. All the culture controls should show a growth and change of color. The serum controls should be sterile; the normal serum controls may or may not be sterile, depending upon the amount of natural bactericidal amboceptors which it contains for the test organism. The pipets containing the patient's serum are now examined, and a simple numeric expression for the result is obtained by referring to the result of the enumeration of the various dilutions, as determined by the counting of the plates. In this manner the number of bacteria contained in 1 c.c. of the lowest dilution of the bacterial culture that has been completely sterilized is calculated. This will give the number of microorganisms which 1 c.c. of serum would be capable of killing. Although this test affords a convenient basis for the comparison of serums, it must be understood that the expression is entirely arbitrary, and will vary according to the culture employed; this is true of any technic for determining the bactericidal titer of a serum. BACTERIOLYTIC SERUMS IN THE TREATMENT OF DISEASE While bacteriolysis is readily demonstrated with some bacteria both in vivo and in vitro, nevertheless, when such serums are used therapeutically, beneficial results are not dependent solely upon lysis of the infecting bacterium, but are usually the result of a combination of lysis with increased phagocytosis, due to the simultaneous presence of bacteriotropins (immune opsonins). When one recalls the close similarity in general properties that exists between bacteriolysins and bacteriotropins, the difference between extracellular and intracellular lysis is relatively slight, and tends to strengthen Metchnikoff's views regarding the close relationship of the bacteriolysins to leukocytic products and phagocytosis. While extracellular lysis can occur in the absence of cells, especially in vitro, yet in the administration of antibacterial serums the activities of the leukocytes are much in evidence, extracellular lysis or bacteriolysis proper being rather subsidiary to intracellular lysis or phagocytosis. The preparation and methods of standardization of antibacterial serums are given in the chapter on Passive Immunization. Most effort in this direction has been expended on the preparation of antiserums for the treatment of meningococcic, streptococcic, pneumococcic, and gonococcic infections, and the greatest success has been attained with the various antimeningococcic serums. Hemolysis is the term applied to the solution or lysis of red bloodcorpuscles. Strictly speaking, it would include the disintegration and solution of the stroma, although in practice the term is applied to any process in which the cells are so injured as to liberate hemoglobin into the surrounding fluids, with or without solution of the stroma. Hemolysis may be caused by various physical, chemical, and specific agencies. The prolonged agitation of blood with glass beads, for instance, may result in the mechanical rupture of erythrocytes. The addition of blood to hypotonic solutions of sodium chlorid or to plain water, results in ready and complete hemolysis, the fluid being transformed from an opaque red suspension of erythrocytes to a clear, transparent red fluid. Various chemicals, such as acids and alkalis, may also produce hemolysis. As previously stated, a few bacterial toxins, such as tetanolysin and staphylolysin, are known to be hemolytic; the same is true of certain vegetable toxins, such as abrin and ricin, and of some animal toxins, such as cobra, toad, and scorpion venoms. Just as bacteria may be killed and possibly broken up by specific bacteriolytic amboceptors and complements, so, in like manner, hemolysis may be caused by specific hemolytic antibodies known as hemolysins. Working in unison with complements, the mechanism of both bacteriolysis and serum hemolysis is probably identical. The simplicity of hemolytic experiments, the rapidity with which they may be performed and terminated, and the ease with which hemolysis may be observed by the naked eye have rendered the specific serum hemolysins particularly useful in the study of amboceptors and of complements, and of cytolytic phenomena in general. In fact, bacteriolysis was not thoroughly understood until Bordet discovered the hemolysins, and demonstrated the analogy that exists between bacteriolysis and hemolysis, a discovery that led to a vast amount of research work and controversy, to many important discoveries, and to the final evolvement of diagnostic reactions of great value. were more or less directly injurious, and incapable of replacing human blood. In 1875 Landois demonstrated experimentally that while transfusion of blood from one animal to another of a different species may prove injurious and even fatal, transfusion to an animal of the same or of very closely related species produced no ill effects. The explanations offered were inadequate, until later researches on the hemolysins showed that the normal blood-serum of one animal may contain hemolysins for the erythrocytes of other animals, and, consequently, upon transfusing this blood to another animal the hemolysin acting with the complement present produced hemolysis in vitro, thereby explaining in part the toxicity of the alien blood. In 1898 Belfanti and Carbone made the observation that the serum of a horse^receiving several injections of rabbit bloocpwas toxic for rabbits, whereas normal horse serum was without injurious effects. At about the same time Bordet published his epoch-making discoveries. He demonstrated further that this acquired hemolytic activity .was highly specific, for when animal A was immunized with the corpuscles of lanimal B the serum of A acquired the power of hemolyzing only the erythrocytes of B, and possibly of other animals closely related zoologically. It was found also that the hemolytic activity of an immune serum was lost by age or could be removed by heating; that in either case the serum, could be reactivated by the addition of a little normal serum or. jperitoneal exudate — phenomena closely resembling that observed in iiacteriolysis, and_due to the action of a thermolabile body or alexin and a second and specific thermostabile antibody named by Bordet the "substance sensibilisatrice." These observations were soon confirmed by Landsteiner and von Dungern, and were followed by very extensive studies by Ehrlich and Morgenroth, who likewise confirmed Bordet 's experiments, but offered a different explanation for the mechanism of the phenomenon, according to the side-chain theory, and renamed the alexin and sensitizing substance concerned in the process "complement" and "hemolytic ambo^ceptor" or "immune body," respectively. envelop as to allow the hemoglobin to escape. Nomenclature. — Normal hemolysins are those found in normal serums; specific or immune hemolysins are those produced as the result of the injection of blood-corpuscles from an animal of a different species. , / Heterolysins are the hemolysins formed by immunization with corpuscles (/ of a different species (the immune hemolysins). Isolysins are hemolysins for the corpuscles of animals of the same species. Autolysins are hemolysins that act upon the corpuscles of the same anima.1 and are quite rare. It should be remarked that isolysin and autolysin are not strictly synonymous terms, as the former does not act upon the corpuscles of the animal producing the hemolysin, but may hemolyze the corpuscles of other animals of the same species. For example, Ehrlich has shown that the serum of a goat that had received several injections of blood from other goats, although actively hemolytic for the corpuscles of goats 1, 2, 4, 5, 6, 9, and less so for goats 3 and 8, was not able to hemolyze those of goat 7 or of itself at all. This immunity of the corpuscles of an animal to its own isolysin was subsequently shown to be due to a complete absence of suitable receptors in its corpuscles. Therefore in cases in which a large internal hemorrhage occurs and the blood is absorbed an autohemolysin is not produced, or produced only in small amounts, and likely to be followed by the formation of an anti-autolysin which regulates the process of blood destruction within physiologic limits. Although little is known concerning the processes of normal blood destruction, as in the disposal of old erythrocytes, it is possible that an autohemolysin is being produced, and that its activity is held within normal limits by an anti-autolysin. A disturbance of this physiologic equilibrium may then be the basis of certain types of primary anemia characterized by excessive blood destruction. Nature of Hemolysins. — According to the side-chain theory, hemolysins are amboceptors or antibodies of the third order, requiring the action of a complement before hemolysis can be produced (Fig. 105). Bordet showed that two substances were concerned in the phenomenon of serum hemolysis, although his views on the mechanism of the process differ from those advanced by Ehrlich and Morgenroth. Ehrlich argued that the hemolytic amboceptor or hemolysin must be an antibody to the receptors of the red blood-corpuscles used in the process of immunization, and if this is true, it ought to unite with the corpuscles. Taking the serum of a goat that had been injected with and was hemolytic for the erythrocytes of a sheep, he destroyed the comple- ment by heating the serum to 56° C. To this he added some sheep's corpuscles, and allowed the mixture to stand for a short time at room temperature, after which it was centrifuged and the supernatant fluid pipeted off in another test-tube. No hemolysis had occurred, and the corpuscles were to all appearances unaltered, but it was now found that if a small amount n£jTnrjmfl,1 gn^t^ggTrinv, as complement, was added to the corpuscles and the mixture placed in the incubator, hemolysis occurred. By adding sheejp^s_corpuscles_and normal goat serum (complement) to the supernatant fluid that had been removed to a separate testtube, hemolysis did not occur. This experiment indicated, therefore, that the red blood-corpuscles had combined with all the antibody. That the action was specific was shown by the fact that the corpuscles of other animals, such as rabbits or goats, for example, exerted no combining power when used instead of the sheep's cells. The union between cell and antibody was considered as being in the nature of a chemical combination and quite firm, as repeated . washing of the cells with normal salt Ehrlich and Morgenroth studied this by means of a similar experiment. Sheep's corpuscles were mixed with normal goat serum (complement), and after a time the mixture was centrifuged and the two portions tested separately. To the corpuscles heated immune serum was added, but hemolysis did not result. To the supernatant fluid corpuscles and heated immune serum were added and hemolysis occurred. This indicated that the alexin or complement did not unite with the corpuscles, as did the antibody in the first experiment, but remained free in the supernatant fluid. By mixing corpuscles, immune serum, and complement and keeping the mixture at 0°-3° C. for several hours, hemolysis did not take place. By centrifuging the mixture and separating the supernatant fluid from the corpuscles, a similar test showed that the red cells had combined with all the antibody, but had left the alexin practically undisturbed. NATURE OF HEMOLYSINS 387 At higher temperatures these relations were more difficult to demonstrate, as hemolysis occurs rapidly, but by leaving the cells and serum in contact for short periods of time, centrifuging rapidly, and testing the corpuscles and supernatant fluid in the same manner, similar relations were found to exist. These experiments led Ehrlich to formulate the theory that complement will unite only with the antibody and not with the red corpuscles, but that it acts upon the corpuscles when united indirectly by means of the antibody. As will be pointed out further on, this view is in direct opposition to that of Bordet, who does not accept this interpretation, but believes that the complement acts directly upon the corpuscles. Ehrlich, therefore, conceived the antibody as being in the nature of an amboceptor or of an interbody between an antigen and complement, with two combining arms — one the cytophile haptophore for union with the cell, and the second, the complementophile haptophore for union with complement. The amboceptor is unable in itself to injure the cell, but preserves its importance in being the only and specific means by which the ferment or complement can attack the cell and cause its destruction. The process of specific serum hemolysis is therefore supposed to be as follows: In fresh immune serum containing both amboceptors and complement, or in a mixture of old or heated immune serum and fresh normal serum (i. e., of amboceptor and complement), the two substances occur independently of each other. When the corpuscles corresponding to the amboceptor are added, the amboceptor unites with these and the complement unites with the amboceptor, the amboceptor, therefore, standing midway between corpuscles and complement. When these unions have taken place, hemolysis will result. The amboceptor has a greater affinity for the corpuscles than the complement has for the amboceptor, and will unite with the cells at a low temperature, whereas the complement unites with the amboceptor only very slowly at low temperatures. Body temperature favors a quicker union of both, and especially that of complement with amboceptor. Hemolysis, therefore, may occur at low temperatures, but is hastened by higher temperatures, and occurs best at 37° C. As stated in a previous chapter, Ehrlich believes that a great many complements exist in normal serums, which view is in direct opposition to the "unitarian theory" of Bordet, which holds that the one alexin or complement will act with any sensitizer or amboceptor. Of the large number of complements, each is especially adapted for the solution of one or more varieties of cells, which it can dissolve in conjunction with a suitable amboceptor. This is known as the main or dominant complement; other complements that may aid in the process are termed nondominant. In general, it is held that those complements that are especially active in hemolysis are but slightly active in bacteriolysis, and vice versa. Although the amboceptor is depicted as having but one haptophore arm for the dominant complement, it is really a polyceptor, and is so constituted that it combines with the cell to be dissolved, on the one hand, and with a number of complements, on the other. Bordet has never accepted these views. He holds that the antibody is not an amboceptor for uniting cell and complement, but that it sensitizes the cell and renders it susceptible to the direct lytic action of the alexin or complement. According to his views, both antibody and complement may unite directly with the cell, and he has borne out this belief by making experiments almost exactly similar to those made by Ehrlich. In accepting Ehrlich's view, it is a question of considerable practical importance whether the complement may unite directly with free amboceptor. Ehrlich maintains that the two may enter into a loose and easily dissociated chemical combination, which is hastened by heat and retarded by cold. The union of hemolytic amboceptor in cobra venom with the lecithin of corpuscles (Kyes' cobra lecithid), which acts as complement, while it tends to strengthen this view can hardly be accepted as direct proof, as lecithin differs markedly from the ordinary complements found free in serum. Likewise the theory of Neisser and Wechsberg regarding complement deviation, whereby it appears that an excess of amboceptor may combine directly with complement and in this manner rob those amboceptors that are attached to cells of the complement necessary to produce lysis, is quite complicated, and is not universally accepted, the evidence of direct union of complement and amboceptor having not been proved beyond the peradventure of a doubt. It follows, then, as Emery has stated, thai/ we must either assume that the complementophile haptophore of an amboceptor united with its antigen has an increased affinity for complement over and above that of free amboceptors, or we must agree with Bordet that cell and complement unite directly after the former has been sensitized by the action of the antibody. This latter view of the separate union of cell with antibody and complement is supported by the observations of Muir, who found, (upon saturating red blood-corpuscles with antibody and then with complement, that some of the former but none of the latter may be dissociated from the combination and become free in the fluid. However, the dissociated amboceptors found free of complement may be those that did not have time to unite with complement, and there does not appear to be any direct and positive experimental evidence to permit one to decide between Ehrlich's and Bordet's views. While Ehrlich believes that the union between cell and amboceptor is a chemical one and follows ordinary chemical laws, obeying the law of multiple proportions, Bordet holds that the antibody acts as a mordant and sensitizes the cell, comparing the process to the staining of filter-paper when immersed in a dye, or to the use of mordants preparatory to the staining of flagella of certain bacteria. For example, 0.4 c.c. of a hemolytic serum, if added at once, was found to dissolve 0.5 c.c. of corpuscles. If 0.2 c.c. of corpuscles were first added, and amounts of 0.1 c.c. were added subsequently, no lysis took place after that of the first portion added. Bordet cited this as an example of a physical process of the nature of absorption, just as filter-paper when added at once to a dye will be stained a uniform color, whereas if it be added a little at a time, the first pieces inserted will be stained deeply, the subsequent ones less and less so, until the dye is completely absorbed. Recent researches on the colloidal theory of antibodies would indicate that the hemolysins are governed by very complex chemicophysical laws, not as yet fully understood, which regulate the action of colloids on one another and are probably intimately concerned in the processes under discussion. As was stated in a previous chapter, Metchnikoff maintains that both substances concerned in hemolysis are ferments, and that both are adapted for intracellular digestion. He regards complement or his cytase as a digestive ferment derived from leukocytes, and believes that it is set free only when leukocytes are dissolved (phagolysis), either as the result of the injection of a foreign substance or during the process of coagulation. Amboceptor or his "fixateur" is likened to enterokinase, and like it acts as an accessory ferment that unites the more potent ferment (cytase) to the particle to be digested. He also regards it as being derived from leukocytes, and considers that the amount formed depends upon the degree of phagocytosis that occurs during the absorption of the antigen. In the conception of immunity as being fundamentally a process of nutrition, and in the belief of the existence of more than one complement, the similarity between the views of Ehrlich and those of Metchnikoff is indeed striking. Analogy between Bacteriolysis and Hemolysis. — Studies in hemolysis aided greatly in a correct understanding of the mechanism of bacteriolysis. It became apparent that two substances were concerned in bacteriolysis — one, the thermostabile amboceptor present in the immune serum, and the second, thermolabile alexin or complement, furnished by the peritoneal exudate in the Pfeiffer test, or by any fresh normal serum in the test-tube bacteriolytic reaction. The discovery and study of the specific serum hemolysins aided greatly in a better understanding of bacteriolysis and cytolysis in general. Specificity of Hemolysins.— The hemolysins are highly specific antibodies, and although partial or group hemolysins may be formed and act upon the corpuscles of closely related species, as antihuman hemolysin on the corpuscles of the higher apes, yet the main hemolysin may be so potent that high dilution of the immune serum practically rules out the activities of group hemolysins, the hemolytic amboceptor proving highly specific for the alien corpuscles responsible for its production. Just as small amounts of antitoxins, agglutinins, and opsonins may be found in normal serums, so, also, normal hemolysins may be present. Their most important practical significance is concerned with complement-fixation reactions, where a close and intimate quantitative relation exists between the complement and hemolytic amboceptor used. As an excess of hemolytic amboceptor may produce hemolysis with a decreased amount of complement, in a given test for free complement, as in Wassermann's syphilis reaction, the patient's serum may contain so much natural antisheep amboceptor as to make up for slight binding of complement and give undue hemolysis or even a false negative result. Hemolysis of alien corpuscles by a normal serum is found to depend upon the same mechanism of amboceptor and complement as in the artificial immune serums. The amboceptors are easily removed by adding the corresponding corpuscles to the cold serum and centrif uging the mixture after allowing it to stand at 0°-5° C. for an hour or two. The supernatant fluid will now be found to be free from amboceptors, whereas by adding a little normal complement serum to the corpuscles hemolysis results, indicating that the amboceptors had been bound to these. If a normal serum contains several different amboceptors for as many different bloods, all may be removed at the one time by adding the respective corpuscles to the serum and allowing sufficient time to elapse for the amboceptors to become linked to their corpuscles. when they gain access to the blood. It is probable that, aside from hemolysins, various normal and immune cytolysins play an important part in the processes of immunity. While the normal hemolysins that may be found in the serums of various animals havev not as yet been fully worked out, the following table, compiled by Sachs1 is a resume of the work reported in the literature on the subject: Kolmer and Casselman2have titrated the natural hemolysins for the corpuscles of various vertebrates in a large number of human serums. Most interest centers about the occurrence of natural antisheep hemolysin, because of the wide-spread use of an antisheep hemolytic system in complement-fixation reactions, as, for example, the Wassermann syphilis reaction. In over 80 per cent, of human serums there is present sufficient natural amboceptor for sheep's cells to give well-marked or complete hemolysis. Although this factor must be considered in using an antisheep hemolytic system in complement-fixation reactions, yet with a proper understanding of principles and the employment of a satisfactory technic the danger of error is reduced to a minimum. In the following table the percentages of serums showing 100, 75, 25, and 0 per Kolmer and Williams 1 have likewise studied the hemolysins found in normal rabbit serum, as preliminary to some work concerning the site of formation of immune hemolysins. The results obtained with the maximum dose of serum (0.2 c.c.) are given in the following table: In 1892 Maragliano2 directed attention to the fact that the bloodserum of patients afflicted with various diseases exerted a hemolytic influence on the blood-corpuscles of healthy persons. Later Ascoli3 found the serums of cancer, pneumonia, and Addison's disease to be actively hemolytic for normal corpuscles. Weil, Crile, Blumgarten and Whittemore, and others have found a large proportion of the serums of lower animals and man suffering with malignant tumors to possess hemolytic activity for normal erythrocytes, and that a reaction based upon this property may have diagnostic value. While isohemolysins are to be especially found in the serums of cancerous persons, and the corpuscles of tuberculous persons are hypersensitive and readily hemolyzed, reactions based upon these observations are not specific, although they may have some diagnostic value in relation to other symptoms. It is well to remember this property of cancer serum, especially in making / blood transfusions. The results of many isohemolytic tests with human sera and corpuscles by different investigators have shown that human isohemolysins may be present, and that they have a practical importance in relation to the dangers of blood transfusion. The consensus of opinion is to the effect, however, that hemagglutinins are of more importance in this connection. The technic of these tests is given on page 311. Production of Immune Hemolysins. — Hemolysins are readily produced by injecting suitable animals with several doses of red bloodcorpuscles. For this purpose rabbits are commonly employed. Some hemolysins are more readily produced than others; for example, antisheep hemolysin is easily prepared, whereas it is far more difficult to secure a potent antihuman hemolysin. The various methods employed in preparing hemolytic serums have been described in the chapter on Active Immunization of Animals. Antisheep hemolysin for conducting the Wassermann reaction is readily prepared by giving a rabbit three or four intravenous injections of 5 c.c. of a 10 per cent, suspension of washed sheep's cells in sterile normal salt solution at intervals of three days. The blood-cells should always be washed three or four times with an excess of salt solution to remove all traces of serum, in order that precipitins may not be produced and anaphylactic shock of the inoculated animal avoided. The portion of the erythrocyte that is responsible for the production of hemolysins is a moot question. Bordet and von Dungern maintain that the stroma is the exciting agent; Nolf and others believe that the stromata produce hemagglutinins, and that the hemoglobin is chiefly concerned in the production of the hemolysin. General Properties of Hemolysins. — Hemolysins are highly resistant antibodies, and are easily preserved. Sterile immune serum may be inactivated by heating in a water-bath for half an hour at 56° C., and may be preserved for many months if small amounts are placed in ampules and kept in a cold place. If an equal quantity of neutral glycerin is added to the clear inactivated serum it will aid greatly in its preservation. The amboceptors resist drying to a well-marked degree, and filterpaper saturated with the immune serum and dried, after the method of Noguchi, preserves the hemolytic activity in a remarkable degree. Heating an immune serum at 56° C., for half an hour, as in the process of inactivating complement, does not materially injure the hemqlytic activity of a potent serum. A temperature of 70° C. or above may cause deterioration and finally destroy the amboceptors. As was previously mentioned, hemolytic amboceptors possess a great affinity for the receptors of their homologous corpuscles, and will readily unite with them at a low temperature. At incubator temperature the union is quite rapid, so that corpuscles may be " sensitized" within half an hour. Source of Hemolysins. — As has been stated elsewhere, MetchnikofT regards the leukocytes as the source of fixateur or amboceptor formation. Bulloch found that the amount of hemolytic amboceptor in a serum runs parallel with the number of mononuclear leukocytes, and he regards this as an indication of the activity of the lymphoid tissue in general, which he considers as the main source of amboceptor formation. While it is probable that endothelial cells and mononuclear leukocytes are especially concerned in the process, our own investigations in this field would indicate that the process is more general, being participated in by cells of other tissues which possess suitable combining affinities for the alien corpuscles. Antihemolysins. — A further step in the study of hemolysins, but one more of theoretic than of practical interest, was the discovery of antihemolysins. By injecting guinea-pigs with normal rabbit serum containing amboceptors for ox blood, Bordet secured a serum that inhibited the action of anti-ox immune serum. Ehrlich and Sacks, by injecting a goat with normal rabbit serum, likewise secured a serum that acted as an anti-amboceptor against immune hemolytic amboceptors for ox blood. Ehrlich argued that the anti-amboceptor acted against the complementophile group of the amboceptor, which prevented union with a complement from taking place. This view was advanced in support of his theory concerning, the two-armed character of the amboceptor and that an anti-amboceptor may be produced against either the cytophile or the complementophile group or both. In these particular serums, however, the investigators may have been working with an anticomplement instead of an anti-amboceptor. A specific hemolysin — one, for example, specific for dog blood, derived from treating a rabbit with dog cells — is highly toxic for dogs, being capable of producing hemolysis in vitro and a clinical condition known as hemolytic jaundice. It is possible, however, gradually to immunize a dog against this amboceptor for his own cells by starting with very small doses and gradually increasing these until it is found that the animal tolerates amounts that would be fatal to non-immunized animals. If a portion of this serum is now added to the specific hemolytic serum, it will be found that the power of the latter is inhibited. Although this action may likewise be due to anticomplement, it is probable that an anti-amboceptor against the cytophile group of the amboceptor is also formed, which prevents the amboceptor from uniting with the red bloodcells, although conclusive experimental evidence of this has not been adduced. There is probably no other group of antibodies that possesses greater diagnostic value than do the hemolysins, a fact that was demonstrated in the practical application of the Bordet-Gengou phenomenon of complement fixation in the diagnosis of syphilis and other infections. By adding sensitized corpuscles — i. e., corpuscles with their homologous amboceptors — to a fluid, the presence or absence of complement may be determined. If complement is present, hemolysis will occur and be complete or partial, depending upon the amount of complement available; if hemolysis does not occur, it may be concluded that free complement is absent. This is the basis of the complement-fixation diagnosis of syphilis, gonorrhea, glanders, differentiation of proteins, etc. When a proper amount of complement is added to a mixture of antigen and its immune serum (containing amboceptors), it is bound to these amboceptors, so that when corpuscles and hemolytic amboceptor are subsequently added, hemolysis does not occur, since there is no available complement, it having been "fixed" by the first amboceptors. If, however, amboceptors for the antigen in the first instance are not present, as where a normal serum is used, the complement remains free and acts with the hemolytic amboceptor to produce hemolysis of the test corpuscles. In this manner the hemolysins and their corresponding corpuscles are employed as indicators or tests for the presence of free complement, so that if an antigen is known, the antibody may be determined; or vice versa, by using a known antibody, the antigen may be determined, the criterion in each instance being whether complement is or is not bound or "fixed," a fact that is determined by the subsequent addition of a hemolysin and its homologous corpuscles. lytic phenomena in general. Quantitative Relationship between Hemolytic Amboceptor and Complement. — From a practical as well as a theoretic standpoint an important property of amboceptor and of complement is the quantitative relationship that each bears to the other. This is especially important in hemolytic reactions, where an excess of either may compensate for a decrease of the other and yield fallacious results. If a certain amount of guinea-pig's complement is necessary to lyse 1 c.c. of a 2.5 per cent, suspension of sheep's cells, along with hemolytic amboceptor, then double this amount of complement will be required to lyse 2 c.c. of the same blood, and so on. If a constant quantity of corpuscles and hemolysin are added to a series of test-tubes, and increasing amounts of complement after incubating the mixtures for an hour the smallest amount of complement that produces complete hemolysis is called a unit, and in this manner the strength or activity of a serum complement is measured or titrated. In a similar manner the hemolytic activity of a serum or its measure of hemolysin may be determined by placing in a series of tubes, as previously directed, a definite and equal amount of corpuscle suspension, and to each tube is then added an amount, also definite and equal, of a normal serum as complement, which is knowi\ to be incapable of causing hemolysis. There are next added decreasing and graduated amounts of the immune serum whose native complement has been destroyed by inactivation. After incubating the mixtures for an hour, the smallest amount of inactivated immune serum that will just produce complete hemolysis is known as the amboceptor unit of the serum. In other words, there are three substances concerned in serum hemolysis : the amboceptor, the corpuscles, and the complement. By taking two of these as constants, e. g., the corpuscles and the complement, the unit of amboceptor may be determined; or by taking the corpuscles and amboceptor as constants the unit of complement may be determined. Since the corpuscles and amboceptor are most stable, these may be used as constants, and the unit of complement determined under these conditions as preliminary to complement-fixation reactions. It is important to bear in mind, in this connection, that the titer of an immune hemolytic serum will vary with the complement used. For example, an antisheep amboceptor is much more active when guinea-pig quantity of rabbit serum as complement. After determining the unit of amboceptor or complement — that is, after adjusting the hemolytic system to exact proportions — the results that follow the varying quantities of complement and amboceptor require the most careful consideration. Less than one unit of amboceptor with one unit of complement cannot yield complete hemolysis; likewise if with one unit of amboceptor less than a unit of complement is combined hemolysis is incomplete; with one unit of amboceptor and one unit of complement and a double dose of corpuscles hemolysis will also be incomplete. With less than a unit of complement and an excess of ambo-,\|/ ceptor, however, hemolysis may be complete. The complement may be * reduced to so small an amount that hemolysis is incomplete no matter how much amboceptor is used, but the important fact to be borne in mind is that a slight decrease in complement may be compensated for by the presence of many units of amboceptor, so that complete hemolysis results and a false reaction is secured. The converse of this is true to a less marked extent — i. e., an excess of complement may compensate for a decrease in amboceptor, but is less capable of doing so. These facts are of the utmost importance in making hemolytic ex- '• periments, as in complement-fixation reactions, where the entire test depends upon demonstrating whether or not a portion or the whole of the complement used has been fixed. Unless, in a series of hemolytic reactions, the amount of amboceptor employed is the same throughout, the amount of complement acting in these cannot be determined by comparing the degree of hemolysis. This is true especially in cases where a small amount of complement is fixed, as in the Wassermann reaction, with a serum containing a small amount of syphilitic antibody, when the presence of an excess of hemolytic amboceptor may give complete hemolysis and overshadow the fact that a small amount of complement has been actually fixed by syphilitic antibody and antigen. Method of Titration of Immune Hemolysin. — Various methods have been employed by different workers in this field, but all are based upon the same principles as have been here outlined. A small amount of immune serum is inactivated by heating in a waterbath at 56° C. for half an hour. In testing the serum of a rabbit during the process of immunization 2 or 3 c.c. of blood are easily secured from the ear, and the serum is separated. After it has been inactivated, the serum is diluted to 1 : 100 (1 c.c. of serum to 99 c.c. of salt solution, or 0.1 c.c. serum+9.9 c.c. of salt solution). healthy pig under ether anesthesia into a Petri dish or centrifuge tube. This serum is diluted 1 : 20, making a 5 per cent, solution, by adding 1 c.c. of serum to 19 c.c. of salt solution. Each cubic centimeter of this dilution contains 0.05 c.c. of undiluted serum, which experience has shown is a satisfactory amount to use. The corpuscle suspension is then prepared. The blood used depends upon the kind of amboceptor that is to be titrated. With sheep and ox blood, a 2.5 per cent, suspension of washed corpuscles may be employed. With antihuman amboceptor, the corpuscles are usually used in 1 per cent, suspension. (See Noguchi Modification of Wassermann Reaction.) After the corpuscles have been washed three times, 1 c.c. is placed in 39 c.c. of salt solution, or sufficient salt solution is added to 2.5 c.c. of the corpuscles to make the total volume equal 100 c.c. To a series of six sterile test-tubes increasing doses of the diluted immune serum are now added, together with 1 c.c. of complement dilution, 1 c.c. of corpuscles suspension, and sufficient normal salt solution to make the total volume in each tube about 3 or 4 c.c. The following table shows the method of preliminary titration of a hemolytic serum: In this instance the unit of amboceptor is 1 : 250, which is too low for a satisfactory antisheep serum. The rabbit should, therefore, receive another dose or two of corpuscles, and the serum be titrated again in from four to seven days after the last injection has been given. In this titration it will be well to use a higher dilution of the inactivated immune serum, as 1 : 1000. This may be prepared by adding 1 c.c. of a dilution of 1 : 100 with 9 c.c. of normal salt solution and mixing well. The titration is then proceeded with as follows: 1. 1 c.c. of corpuscles in 1 c.c. of amboceptor dilution. This tube should show no hemolysis, as the serum has been inactivated and is too highly diluted for complement activity, even though native complement were present. may show a trace of hemolysis, due to the presence of a small amount of natural amboceptor for the corpuscles used. As a general rule, guinea-pig serum is free from natural antisheep amboceptor, or the amount is so small under these conditions that it is not necessary to remove it. . 3. 1 c.c. of corpuscles in 3 c.c. of salt solution. This tube should show no hemolysis, and serves to show that the diluent was isotonic. In the foregoing titration it is found that 0.25 c.c. of 1 : 1000 dilution of amboceptor is the unit, or the titer is 1 : 4000. This method is less difficult than preparing a series of dilutions of amboceptor as a 1 : 100, 1 : 200, 1 : 500, 1 : 1000, 1 : 2000, etc., using a cubic centimeter of each dilution. The method requires accurate pipets and careful work, but yields uniform and satisfactory results (Fig. 106). The rabbit may now be bled under anesthesia. The serum is separated and inactivated and again titrated, as the final titration, for some unknown reason, is likely to be a little lower than in the primary tests. When suitably preserved, a hemolytic serum will maintain its activity for long periods of time; it should always, however, be titrated before complement-fixation tests are undertaken. Methods for Removing Hemolysins from a Serum. — In general, these aim to remove the natural hemolysins, such as natural antisheep hemolysin, from human serums preliminary to making the Wassermann test, or from a guinea-pig serum that is to be used as complement. The method of removal consists simply in adding corpuscles to the serum, and allowing sufficient time for the corresponding hemolytic amboceptor to become attached and then removing both by centrifuging the mixture. If the serum is fresh, it should be cooled to 0° to 3° C., in order to inhibit complement activity, which would hemolyze a portion of the corpuscles. To remove natural antisheep hemolysin from a patient's serum place a measured quantity of cold serum in a centrifuge tube and add four volumes of a 2.5 per cent, suspension of sheep's cells. This will make a dilution of 1 : 5, so that 0.5 c.c. of the dilution is equivalent to 0.1 c.c. of undiluted serum. After placing the tube in ice-water for from fifteen to thirty minutes centrifuge thoroughly to remove the corpuscles. The process may be carried out after the serum has been inactivated, in which case it is not necessary to work with cold serum. In removing a natural hemolytic amboceptor from a guinea-pig serum that is to be used as complement a measured amount of serum is first removed to a separate tube and thoroughly chilled in a glass of cracked ice. If a large amount of serum is to be used, for example, 5 c.c., it is well to place about 0.1 to 0.2 c.c. of pure undiluted corpuscles, after their last washing, in the bottom of a centrifuge tube. This quantity of corpuscles does not materially affect the dilution of the serum. If a smaller amount of serum is used, such as 1 c.c., it is well to add 8 c.c. of a 2.5 per cent, suspension of corpuscles, and after centrifuging the mixture the final dilution of 1 : 20 is secured by adding 10 c.c. of salt solution to the supernatant diluted serum. Method of Determining Natural Hemolysins in Serum. — To ascertain whether or not a certain natural amboceptor is present in a serum it is merely necessary to inactivate the serum, and to a measured amount, for example, 0.2 c.c., add 1 c.c. of complement serum (1 : 20) that is known to be free of the particular amboceptor in question, and 1 c.c. of a 2.5 per cent, suspension of the corresponding corpuscles. Sufficient salt solution is added to bring the total volume to 3 or 4 c.c. The mixture is then incubated at 37° C. for one or two hours, when the occurrence of hemolysis indicates the presence of the amboceptor for the corpuscles employed. SERUM DIAGNOSIS OF PAROXYSMAL HEMOGLOBINURIA 401 the serum with nine parts of normal salt solution, and to a series of testtubes add increasing amounts of 0.05 c.c., 0.1 c.c., 0.2 c.c., 0.4 c.c., 0.8 c.c., 1 c.c., and 2 c.c., corresponding respectively to 0.005, 0.01, 0.02, 0.04, 0.08, 0.1, and 0,2 c.c. of the undiluted serum. Add 1 c.c. of a 5 per cent, dilution of fresh amboceptor-free guinea-pig serum as complement, and 1 c.c. of a 2.5 per cent, suspension of the corpuscles; sufficient salt solution is added to make the total volume about 4 c.c. After shaking, the tubes are placed in the incubator at 37° C. for two hours, removed, and the results read, or the tubes may be placed in a refrigerator overnight and the results read in the morning. A hemolytic substance may be demonstrated in the blood-serum of most cases of paroxysmal hemoglobinuria at certain periods. Although the exact nature of this substance is unknown, it has many of the properties of isohemolysins, being capable of sensitizing the red corpuscles of the patient or those of a normal person at a low temperature, hemolysis being effected in the presence of fresh serum, presumably with complement, and best at body temperature. According to Cook, about 90 per cent, of hemoglobinurics show a positive Wassermann reaction. Landsteiner found that about 10 per cent, of paretics showed similar reactions, and, other observers have reported finding isohemolysins in epileptics and idiots. Malaria and trypanosomiasis have also been regarded as causes of this condition, the most evidence, however, indicating that the etiology has a luetic origin. It is possible that the hemotoxin is similar to the hemolysin of cobra venom, being in the nature of an amboceptor complemented by the fatty acids or lecithin of red corpuscles (endocomplement) or by a serum complement. First Method. — According to Ehrlich, a small tourniquet should be applied about the base of one of the patient's fingers, and this is then kept immersed in ice-cold water for half an hour. Blood from the finger thus constricted is then collected in a Wright capsule, and blood from a finger of the other hand is used as a control. Both are allowed to clot and are then centrifugalized. The serum from the finger held in iced water is tinged red from dissolved hemoglobin, whereas the control serum is not tinged or at least not tinged so deeply. test-tube, cooling to 0° C. for half an hour, heating subsequently to 37° C. for three hours. The presence or absence of hemolysis is observed, and the results compared with those obtained from normal blood treated in the same manner and at the same time. Third Method. — This technic is carried out in vitro in the following manner: Pipet 2 c.c. of the patient's blood in a small test-tube and separate the serum. At the same time place 1 c.c. of blood in a centrifuge tube containing 9 c.c. of a 1 per cent, solution of sodium citrate in normal salt solution. Wash the corpuscles twice and suspend the sediment in 10 c.c. of normal salt solution. Then, secure a cubic centimeter of a fresh serum from a normal person. Proceed to make the following mixtures : Tube 5: 1.0 c.c. corpuscle suspension. Add sufficient normal salt solution to each tube to make the total volume measure 2 c.c. Shake gently, and place in the refrigerator at a low temperature (not higher than 4° C.) for an hour. Shake each tube gently and place them in the incubator at 37° C. for two hours. The tubes are then centrifuged and the presence or absence of hemolysis is noted. Usually the patient's serum shows hemolysis of greater or less degree. Similar mixtures may be made with the patient's serum and the corpuscles of a normal person. The hemolytic substance is capable of lysing these to the same degree that it does the patient's own cells. Various substances have been employed to test the resistance of the red blood-corpuscles. Of these, the hypotonic solutions of sodium chlorid, of varying strength, have yielded results of clinical importance, especially in the study of paroxysmal hemoglobinuria, the primary anemias, etc. The following technic, slightly modified after the methods used by Smith and Brown, Gay, Moss, Karsner, and Pearce, is a ready means for determining the resistance of human corpuscles to salt solutions of different tonicities. Chemically pure sodium chlorid is dried for two hours at 170° C., and immediately weighed in amounts necessary to make 500 c.c. of salt solution, ranging from 0.1 to 0.6 per cent, in gradations of 0.02 per cent. This means the preparation of twenty-six different solutions, which should be preserved in proper-sized bottles fitted with tight rubber stoppers. When the test is needed only occasionally, these solutions are readily prepared by filling a 50 c.c. buret, graduated in one-tenths, with distilled water, and another with a 1 per cent, solution of pure dried sodium chlorid. From these, the various solutions are readily prepared after the following manner: distilled water. Similar dilutions are made, until the final dilution is reached. In many instances it may not be necessary to use so large a number of dilutions, as from 0.5 to 0.2 per cent, may be sufficient range to indicate the tonicity. . Five cubic centimeters of blood are aspirated, under aseptic precautions, from an arm vein of the patient, and immediately placed in 25 c.c. of sterile 1 per cent, sodium citrate in 0.85 per cent, sodium chlorid to prevent coagulation. The flask or large centrifuge tube is well shaken, and the mixture is centrifuged at sufficient speed to throw down the corpuscles. The supernatant fluid is drawn off, and the corpuscles are washed once or twice more with sterile normal salt solution. After the last washing the supernatant fluid is removed, leaving the erythrocytes at the bottom of the tube. A series of small test-tubes (10 by 1 cm.) are marked appropriately and placed in a rack. To each tube 3 c.c. of the various hypotonic salt solutions and 0.05 c.c. of the red blood-corpuscles (about 1 drop) are added. The salt solution and corpuscles in each tube are well mixed, and the whole series is placed in the refrigerator for from eighteen to twenty-four hours, after which the readings are made. The tube of lowest dilution — even if it shows but a trace of hemolysis — represents the point of initial hemolysis or minimal resistance. The strength of salt solution in which all the corpuscles are hemolyzed represents the point of complete hemolysis or maximal resistance. Normally, the minimal resistance is about 0.47, and the maximal resistance about 0.3 (Morris). Hill1 has found the points 0.457 and 0.340 respectively, for normal blood. Nature of Venom Hemolysis. — In a previous chapter the statement was made that certain snake poisons, and especially cobra venom, are actively hemolytic. Flexner and Noguchi x first demonstrated that the blood-corpuscles of certain species of animals undergo hemolysis when a suitable serum is present, and believed that the venom contained an amboceptor that was active with serum complement. Shortly afterward Kyes2 discovered that venom may hemolyze the corpuscles of certain animals without the presence of serum, and believed that the complement-like activator was contained within the corpuscles, to which he accordingly applied the name endocomplement. Later Kyes2 confirmed Calmette's observation that practically any serum, when heated to 65° C. and higher, showed an increased activity in the process of venom hemolysis. Kyes and Sachs 3 then concluded that endocomplement was not of the nature of a thermolabile complement, but was, rather, a combination of lecithin and the stromata of erythrocytes. Kyes later succeeded in combining cobra venom and lecithin by shaking a watery solution of venom with a solution of lecithin in ether, forming cobra-lecithid, which was found to be actively hemolytic. The erythrocytes of various animals differ in their susceptibility to venom hemolysis. For instance, those of the dog and guinea-pig are most susceptible to the process; those of the ox, goat and sheep are entirely refractory, whereas those of the horse, rabbit, rat, pig, and man occupy an intermediate position. Sacks suggested that the variation in hemolytic resistance of red blood-cells from these species of animals was dependent on the amount of lecithin contained in the cells. Kyes, on the other hand, believes that since all erythrocytes contain sufficient lecithin to activate cobra venom, the varying susceptibility depends rather on the availability of the intracellular lecithin for the reaction, i. e., whether the lecithin in the cell is available in a free state. 406 VENOM HEMOLYSIS According to this theory, therefore, any factor that modifies the availability of the cell lecithin may modify the susceptibility of the cells for hemolysis with cobra venom. Noguchi1 has questioned the correctness of this view. He holds that although lecithin exists in the stroma of all kinds of corpuscles, it is not present in a form available for venom activation, and that the degree of susceptibility to hemolysis depends chiefly upon the amount of ether-soluble activators present in the cells, as, for example, fatty acids, particularly oleinic acid, and their soluble soaps. In his opinion heating an inactive serum to 65° C. and higher renders it active with venom, owing to the presence of a protein compound of lecithin. A normal serum may, therefore, contain two activators, one being thermolabile and resembling complement (inactivated by calcium chlorid), and the other Joeing thermostabile and a protein lecithin. By adding oleinic acid or its soluble soap to a non-activating serum the latter is rendered highly active so far as venom hemolysis is concerned. Hence while Kyes regards lecithin as the chief component of endocellular complement, Noguchi regards the fatty acids, neutral fats, and soluble soaps as the active agents. Other observers consider the fatty acids and soap as indirect activating agents in venom hemolysis, in that they possess the power of modifying the cell and rendering the intracellular lecithin available for the formation of complete hemolysin. On the other hand, in susceptible cells the union of cobra venom and lecithin occurs directly with the formation of the complete hemolysin, Kyes' cobra-lecithid,. due to the splitting of the fatty acid radical from the lecithin. Ludecke, von Dungern, and Coca and Manwaring regard this product as a venom-free lecithin derivative, and not as a lecithin. They prefer to call the active principle "cobralecithinase," and the complete hemolysin" mono-fatty-acid-lecithin." According to Kyes, the relative amounts of lecithin and venom amboceptor show quantitative relationship comparable to serum amboceptors and complements, namely, that, within certain limits, the larger the amount of venom, the smaller the amount of lecithin necessary to effect hemolysis; and, conversely, the larger the amount of lecithin, the smaller the amount of venom required. Further reference to the intimate relationship that exists between lipoids and complements and hemolysis is also made in the discussion on the nature of complements, on p. 351. VENOM HEMOLYSIS IN SYPHILIS The first application of venom hemolysis was made by Weil,1 who found, in testing the hemolytic powers of cobra venom with cells derived from persons suffering from different diseases, that the red cells of syphilitic individuals offered a characteristic resistance. Various explanations have been offered for this phenomenon: 1. It was argued that the quantity of red-cell lecithin is actually diminished in syphilis after the primary stage because pallidum toxin attacks the same lipoidal substances of tissue cells as does cobra venom, in this way accounting for the diminished amount of lecithin that can be extracted in syphilis, as compared with that obtained from normal tissues. Accordingly, the increase in resistance is only apparent, and is due rather to the fact that there is insufficient endocomplement for the venom amboceptor. 2. Another explanation offered was that the increased resistance of the red cells of syphilitic persons to venom hemolysis is due to the fact that pallidum toxin attacks endocomplement, and that the cells become specifically immunized to this deleterious influence in much the same way that repeated injections of such a hemolytic agent as saponin leads in rabbits to the production of red cells, which show a marked resistance to saponin hemolysis but not to any other hemolytic agent. 3. Pallidum toxin was believed to so affect the lecithin content of red cells as to render a smaller quantity of it available in a free state for union with the venom amboceptor to form the hemolysin. 4. Another theory advanced was that pallidum toxin effects a dissociation of red cells between lecithin and cholesterin, the latter substance causing inhibition of hemolysis. Whatever may be the true explanation, the fact has been quite well attested that the red cells of a large percentage of persons in the tertiary stage of syphilis exhibit a characteristic increased resistance to venom hemolysis, and while the cobra hemolysis test in this disease is of secondary importance to the Wassermann reaction as a diagnostic procedure, yet it represents one of the most interesting of biologic phenomena, and may possibly be employed in other clinical methods. pulverized venom and dissolving this in 10 c.c. of normal saline solution (1 : 1000). This stock dilution is best preserved in amounts of 1 c.c. in sealed ampules, kept in the frozen state in the ice chest in a wide-mouthed well-stoppered vacuum bottle containing salt and ice (Schwartz). Each cubic centimeter is sufficient for making three tests, so that the 10 ampules will be enough for 30 tests, or 1 gram of venom for 3000 reactions. Or the dried venom may be weighed out in amounts of 0.0005 gram in test-tubes, and diluted, just before being used, with 1 c.c. of normal salt solution (1 : 2000). Immediately before the tests are conducted subdilutions are prepared of the stock dilution (1 : 1000), using separate pipets for each, as follows: These amounts are sufficient for making three tests; if more tests are to be made, larger amounts of the various dilutions will keep fairly well in a good refrigerator for several days, but it is always well to plan the work so that the exact amount will be prepared and no waste occur. Each lot of stock solution should be tested occasionally with the cells of known normal and positive persons, to make certain that the venom is active in these dilutions. These titrations are conducted in the same manner as the test. Preparation of Blood-cells. — With a sterile syringe blood is drawn from a vein at the elbow and 2 c.c. placed in an accurately graduated centrifuge tube containing 5 c.c. of a 2 per cent, solution of sodium citrate in normal saline solution. The suspension should be shaken gently to insure mixing and the prevention of coagulation, but defibrination by means of whipping should never be practised. The cells may be prepared at once or placed in the ice-chest overnight. Sufficient normal saline solution is added to bring the total volume to 15 c.c. Mix gently and centrifuge at low speed until the supernatant fluid is clear. Draw off the fluid, add more normal saline solution, mix up the cells, and centrifuge again until clear. Repeat this process once more so that all traces of serum will be removed. After completing the last centrifugalization, which should be thorough (ten minutes), the cells are diluted with 25 volumes of normal saline solution, which makes a 4 per cent, suspension— for instance, 0.8 c.c. of corpuscles would require 20 c.c. of diluent. Just what influence sodium citrate has upon the process is not known, but it is certain that satisfactory results are seldom obtained with blood defibrinated by whipping with rods of glass beads. Similarly, if centrifuged too rapidly, cells are broken up or rendered more susceptible to the venom ambocepter. The Test. — Into a series of five test-tubes (4 by % inches) place 1 c.c. of each dilution of venom, and label each tube correctly; add 1 c.c. of the 4 per cent, suspension of cells to each tube, shake gently, and incubate for one hour at 37° C. Except in cases where the venom dilutions are being frequently used and are known to be reliable, controls should be included. I usually add a normal control of cells from a healthy person with the 1 : 30,000 or 1 : 40,000 dilution and expect complete hemolysis to occur. A preliminary reading is made at the end of an hour; the tubes are shaken gently and placed in the refrigerator overnight; the final reading is made next morning, and should tally quite closely with the preliminary reading. Reading the Results. — Unless the cells are derived from a very strongly reacting case of syphilis, the 1 : 10,000 dilution will be hemolyzed. The normal control tube should show complete hemolysis. If the 1 : 10,000 tube is not hemolyzed and some of the higher dilutions show hemolysis, an error in technic has occurred, and the test should be repeated with fresh dilutions. If complete hemolysis has occurred in all tubes after an hour's incubation, the cells are regarded as being hypersensitive to cobra venom. This occurs as a rule in primary syphilis and in active tuberculosis. PRACTICAL VALUE OF THE VENOM TEST IN SYPHILIS 1. While the test is much simpler than the Wassermann reaction and there is less possibility for errors in technic to creep in, it possesses but two other advantages, namely: (1) It may react positively in latent or tertiary syphilis when the Wassermann reaction may be negative, and (2) it may react positively in treated syphilitic cases when the Wassermann reaction is negative, and thus point to a continuation of treatment. Corson- White and Ludlum 1 found 94 per cent., Schwartz2 69.3 per cent., and Stone and Schottstaedt 3 90.9 per cent, of positive reactions in the active stages of syphilis. 2. The test is positive in but about 20 per cent, of cases of tabes dorsalis and general paralysis (White and Ludlum), a finding obviously inferior to the Wassermann reaction. reactions are but occasionally obtained. 4. Positive reactions may occur in cancer, but otherwise the test is quite specific, and may, in selected cases, prove a valuable adjunct to the Wassermann reaction. However, with a more improved technic in performing the Wassermann reaction, and especially if antigens reenforced with cholesterin are used, the venom test is inferior to the Wassermann. In cases where syphilis or tuberculosis of the lungs is to be differentiated, a negative venom test would indicate tuberculosis, as in this disease the cells are hypersensitive. Normal serum, when added to a lytic dose of cobra venom and human red blood-cells, will not interfere with hemolysis. According to Much and Holzman,4 however, if the serum obtained from a patient suffering from depressive mania or dementia prsecox is added to the mixture of venom and human red blood-cells, the expected hemolysis does not take place. Technic. — A 1 : 5000 dilution of cobra venom is prepared by diluting 1 c.c. of the stock dilution (p. 407) with 4 c.c. of normal saline solution. Enough of the patient's blood is collected from a vein at the elbow to yield at least 1.5 c.c. of serum; heat the serum to 55° C. for an hour. Prepare a 5 per cent, suspension of washed human blood-cells. An effort Into a series of three small test-tubes place 0.4 c.c. of the patient's serum and decreasing amounts of venom — 1, 0.8, and 0.5 c.c. respectively. Next add to each tube 1 c.c. of the blood-corpuscle suspension. The total volume in each tube is brought up to 2.5 c.c. by the addition of normal saline solution. Tube 7:0 1 c.c. blood. The tubes are shaken gently and incubated for an hour at 37° C., when a preliminary reading is made. If the control tubes 4, 5 and 6 are hemolyzed, a positive reaction would be indicated by the inhibition of hemolysis in the first three tubes, 1, 2 and 3. Control tube 4 at least should be completely hemolyzed at the end of half an hour, and in a positive reaction tube 1, containing the same amount of venom with the patient's serum, will show inhibition of hemolysis. . Practical Value.— Corson.- White and Ludlum1 have found the reaction positive in 80 per cent, of cases of the catatonic form of dementia pracox and in 62 per cent, of the hebephrenic type. Only 3 out of 37 cases of manic-depressive insanity reacted positively. Among controls with serums of other diseases positive reactions were secured in one case each of cerebrospinal syphilis, tertiary lues, exophthalmic goiter, and confusional insanity, and in two cases each of general paralysis and epilepsy. The afore-mentioned observers claim, however, that if the venom is carefully standardized with blood-cells that are completely hemolyzed in 1 : 5000 dilution of venom in thirty minutes, the reaction possesses some diagnostic value, having been found, under these conditions, to yield positive reactions in 87 per cent, of cases of dementia praecox and in 100 per cent, of catatonics. According to Citron, the reaction is probably due to interference with hemolysis by an increase in the cholesterin of the serum — a pos1 Jour. Nerv. and Mental Diseases, 1910, xxxvii, 721. Calmette found that the blood of tuberculous patients may activate cobra hemolysin in very small doses, and upon this observation he devised a test that yielded about 65 per cent, of positive reactions in tuberculosis. Positive reactions have, however, been found in other diseases, and the practical value of the test has not been established. Although the red blood-corpuscles of the horse may be hemolyzed by venom without the aid of serum, Kraus, Graff and Ranzi 1>2 found that about 70 per cent, of cancer serums considerably hastened and aided the hemolytic process. A 1 : 5000 dilution of venom is used. In two series of four tubes each place respectively 0.1, 0.2, 0.3, and 0.5 c.c. of the patient's serum (heated); to the first series add 0.3 c.c. of the venom solution, and to the second series 0.15 c.c. of the same. To each of the tubes in the series add 5 drops of a 10 per cent, suspension of washed horse corpuscles; shake thoroughly and incubate at 37° C. Inspect the tubes at the end of fifteen and thirty minutes, and then after one, two, and three hours. FIXATION Historic. — With Bordet's discovery of the hemolysins in 1898, and his demonstration of the role of the antibody or sensitizer and alexin in the process, new light was thrown upon the bacteriolysins, and the close analogy between hemolysis and bacteriolysis soon became apparent. Bordet 's discoveries were quickly verified by Ehrlich and Morgenroth and the German school in general, although his views regarding the mechanism of the processes were questioned. The controversy soon centered upon the question of the unity or the multiplicity of alexins or complements. Bordet at this time advanced his belief in the existence of one alexin or complement that would act with any sensitizer or amboceptor, and he still maintains this view. One of the experiments conducted by him, and later made in conjunction with his pupil, Gengou, in support of his theory, is now known as the Bordet-Gengou phenomenon of complement fixation. This has become widely known as the precursor of all complement-fixation tests, and is the basis of the well-known and invaluable Wassermann reaction for the diagnosis of syphilis. In devising the technic of this important method, Bordet's main object was to show that the complement in a normal serum would unite with either a bacteriolytic or a hemolytic amboceptor, and that, by furnishing sufficient of either amboceptor, all the complement may be " fixed." He argued that if two or more complements existed in the same serum, as was held by Ehrlich, they would demonstrate their presence by exhibiting different affinities for these widely varying amboceptors. Prior to this Bordet had shown that the addition of a small amount of normal serum to an immune hemolysin would result in lysis of the homologous corpuscles, and that the process could not take place without the alexin. He then mixed an emulsion of pest bacilli with antipest serum and added a small amount of normal, unheated guinea-pig serum to supply the alexin or complement. After allowing the mixture to stand for four hours at room temperature, it was sought to determine whether the alexin had been fixed by pest antigen and pest amboceptor, or whether 414 PHENOMENON OF COMPLEMENT FIXATION it was free in the fluid. Bordet knew that the normal alexin serum used in the experiment could produce hemolysis of corpuscles with a homologous amboceptor, so he tested for free alexin by subsequently adding to the mixture anti-rabbit hemolysin and rabbit corpuscles. Hemolysis did not occur, because the alexin or complement had been bound by the pest antigen and amboceptor. When a normal serum was substituted for the antipest serum, hemolysis occurred, because the normal serum contained no sensitizers or amboceptors that could unite with the pest bacilli and "fix" the alexin, which, therefore, remained free, and when the hemolysin and red corpuscles were subsequently added, united with them to lyse the red cells. In this way the corpuscles and hemolysin served as indicators for free or unfixed alexin or complement, just as litmus or phenolphthalein may be used as a test for the presence of an acid or an alkali. By showing, in this manner, that the complement of a serum could be fixed by either bacteriolytic or hemolytic amboceptors, Bordet endeavored to support his views on the unity of complement. Ehrlich and Morgenroth later verified his findings, and in addition, by more delicate and complicated experiments, showed that many complements may be present in a serum, a fact manifested by a different rate of absorption, by the action of specific anticomplements, etc., as mentioned in a previous chapter. While Ehrlich's theory as to the multiplicity of complements has been widely accepted, the subject really possesses greater academic than practical interest, for experience has shown that the results are the same in complement-fixation tests at least, regardless of whether we believe in the unity or in the multiplicity of complement, as under ordinary conditions the complement or complements in a given quantity of serum are capable of being absorbed by bacteriolytic, hemolytic, or other amboceptors. Gengou showed later that not only cellular antigens, such as bacteria and red blood-cells, are capable of stimulating the production of amboceptors, but that the proteins in solution, such as serum and milk, may produce complement-binding amboceptors in addition to precipitins. This subject was later studied more extensively by Moreschi, whose interest became aroused as the result of his theoretic studies upon anticomplements. This investigator observed that, upon mixing a soluble protein with its antiserum precipitation occurred and the existing complement disappeared, a coincidence that led him to assert that the complement disappeared because it was carried down mechanically in the precipitate. This explanation naturally had the effect of leading many to assume that the Bordet-Gengou phenomenon of complement fixation may be the result of a similar precipitation process, and led to many interesting and valuable investigations, especially those made by Gay. It is now generally agreed, however, that protein amboceptors are formed, and that actual complement fixation occurs independently of precipitation. Later Neisser and Sachs elaborated on Gengou's studies, and perfected a complement-fixation technic for the differentiation of proteins that is much more delicate than the precipitin test, and serves to demonstrate and differentiate traces of protein, as in blood-stains, so minute in quantity as not to be appreciable by the precipitin test. Widal and Lesourd applied the Bordet-Gengou reaction to the diagnosis of typhoid fever, using an emulsion of typhoid bacilli and the serum of a typhoid-fever patient, and found that a positive reaction occurred more frequently and earlier than the agglutination test. These observations were made soon after Bordet and Gengou's discovery, and were probably the first direct and practical application of a complementfixation technic in diagnosis. It was not until several years later, however, that the possibilities of the method were seriously considered. Hitherto most experiments were conducted with known antigens and their antibodies. It was shown, especially in the work of Neisser and Sachs on protein differentiation, that when an antigen and its specific antibody are present complement is absorbed, and the specific relation existing between these bodies was again emphasized. Hence in a compkment-fixation test, if the antibody is known the antigen may be found, or if the antigen is known the antibody may be found, the detection in either instance depending upon whether or not complement is absorbed, this being decided by adding corpuscles and their amboceptors to the mixture, the absence or the occurrence of hemolysis determining this point. In this manner Neisser and Sachs were able to diagnose the nature of bloodstains by using solutions of the suspected stains as antigen, and adding, in different experiments, known antiserums secured by injecting rabbits with various bloods. When a positive complement-fixation reaction occurred, they concluded that the antigen of the blood corresponded to the known antibody, and they were thus able to identify the species of animal from which the blood in the stain was derived. Wassermann and Sachs, encouraged by these results, endeavored, by complement-fixation tests, to show the existence of antigens in diseased organs, using tuberculous glands and lungs with an antituberculous serum and the serums of tuberculous persons. Complement fixation occurred under certain circumstances, and these are discussed more fully in Chapter XXIV. These investigations finally led to the serum diagnosis of syphilis, in which the antigen was supplied by tissues containing large numbers of the Spirocheta pallida. By furnishing the antigen it was hoped that the luetic antibody could be detected in the body-fluids through the absorption of complement, by the union of the antigen and its antibody in the complement-fixation test. Although the primary results were somewhat discouraging, the possibility was shown to exist, and while the original theories regarding the specific nature of the antigen-antibody reaction have been modified by subsequent discoveries, nevertheless this reaction of Wassermann, Neisser and Bruck, and Detre has proved itself one of the most valuable diagnostic procedures known. In a paper published in 1901 Bordet 1 gives the results attained with three different antigens and their respective antiserums — pest, typhoid, and Proteus vulgaris. The details of the technic employed with an antigen of pest bacilli and an antipest horse serum are given. in normal salt solution, making a somewhat concentrated emulsion. (6) The antipest horse serum was heated for half an hour at 56° C., to remove the alexin or complement. Normal horse serum (heated) was also employed as a negative control. and were used as the indicatory antigen. To 0.4 c.c. of the pest emulsion 1.2 c.c. of inactivated antipest serum and 0.2. c.c. of guinea-pig alexin were added. This mixture was allowed to remain at the ordinary laboratory temperature (18°-20° C.) for several hours. In order to ascertain whether or not the alexin had been absorbed, hemolysin and erythrocytes were added to the mixture. This was accomplished by sensitizing about 20 drops of washed rabbit's cells with 2 c.c. of inactivated hemolysin for about fifteen minutes, and adding two drops to each of the test-tubes. Hemolysis did not occur 1 Bordet: Ann. de 1'Inst. Pasteur, 1901, xv, 19. because the alexin had been fixed by the pest antigen and antibody. A similar test, conducted with normal serum, hemolyzed in a few minutes because the complement or alexin remained free in the mixture. Even at this early stage Bordet included the important controls on his antigen and serums that are so necessary in all complement-fixation tests. TABLE 12.— — The divergent views of Bordet and Ehrlich on the mechanism of antigen-amboceptor action have been given elsewhere. Bordet believes that the antibody unites directly with the antigen, and serves to sensitize and prepare it for direct union with the alexin or complement, in a manner similar to that of using a mordant in aiding the penetration of a dye-stuff. In the absence of the homologous and specific antibody (sensitizer), the antigen is incapable of absorbing more than very small amounts of complement or none at all. In the absence of antigen, the sensitizer and complement do not unite, or unite to but a very slight degree. The important require-' ment for complement fixation is, therefore, an antigen that has been sensitized by the antibody, and in this manner has an increased combining affinity for complement. According to Ehrlich and Morgenroth, however, the complement does not unite directly with the antigen, but only indirectly through the antibody, which acts as a connecting link or amboceptor between antigen and complement. Antigen alone, or even amboceptor alone, binds the complement only very slightly or not at all. The important requirement for complement fixation is an amboceptor attached to its homol- Complement-fixation tests also serve to demonstrate that absorption of complement is not necessarily followed by lysis of the antigen. For example, anthrax and pest bacilli, when mixed with their homologous amboceptors and complement, show no bacteriolysis or but a very slight reaction. The erroneous conclusion thus reached, that these serums contained no amboceptors, was disproved by Bordet, who demonstrated that they contained amboceptors and that complement was absorbed or fixed although bacteriolysis had not taken place. Whether the difference here depends upon variations in the nature pf lytic and non-lytic amboceptors or whether it is due to the relative amounts of an amboceptor or the construction and constitution of the antigen is not known. It would appear, however, that the last two possibilities are largely concerned, although, so far as complement fixation is concerned, it is immaterial whether or not bacteriolysis occurs. Complement-fixing antibodies, therefore, are probably all in the nature of amboceptors, and these are to be found in varying amounts in practically all immune serums, including antitoxic, agglutinating, and precipitating serums. The importance of having proper controls in practically all tests is especially to be emphasized in complement-fixation work. While the underlying principles are readily understood and the technic is comparatively simple, there are, however, many sources of error that require a thorough understanding in order that an intelligent and reliable complement-fixation reaction may be secured. These refer mainly to nonspecific fixation of complement and to quantitative factors governing complement-fixation technic. Formed elements, such as bacteria and tissue-cells, as well as various ' organic and inorganic material, may fix complement by themselves, i. e., in a non-specific manner, and chemicals, such as acids and alkalis, may destroy it. 1. An antigen alone in certain amounts may absorb complement. ThisV anticomplementary dose of an antigen, as it is called, must be determined beforehand by a process of titration when increasing amounts of antigen are mixed with a constant dose of complement, hemolysin, and corpuscles and the anticomplementary action of the antigen noted by the results of hemolysis, i. e., if a small amount of complement is absorbed, hemolysis will be correspondingly incomplete, if all complement is absorbed, hemolysis does not occur at all. If, therefore, in any complement-fixation test the antigen is used in an amount that will give this non-specific absorption, even to a slight degree, a grave source of error is introduced. As a general rule for all complement-fixation tests, the dose of antigen employed should never be more than one-fourth or one-half of its anticomplementary dose (that amount which of itself is capable of non-specific complement-fixation). 2. A serum may of itself absorb a small amount of complement, especially if it is old or infected with bacteria. This is known popularly as the anticomplementary action of a serum, and in every complementfixation test in order to detect this condition a proper control, consisting of the dose of serum used plus complement, hemolysin, and corpuscles is required, the non-specific absorption of complement being determined by the results of hemolysis. Moreover, perfectly fresh serums may show this non-specific absorption of complement to a slight degree, especially in the presence of the lipoidal extracts used as "antigens" in the Wassermann reaction. Heating a serum to 56° C. for half an hour largely removes this anticomplementary effect of serums, unless they are quite old and infected; accordingly, heated serums are used almost exclusively in complement-fixation tests. This is usually called inactivation, or the removal of native complement from a serum, but in the majority of instances the complement of a serum generally deteriorates rapidly, and the serum is heated mainly for the purpose of removing its anticomplementary action, i. e., its ability to effect non-specific absorption of complement. By referring to the original Bordet experiment, it will be observed that this investigator controlled any non-specific absorption of complement by both the immune and the normal serum in tubes C and D of the series by using the full dose of these serums, with a similar amount of complement, and noting that hemolysis was complete. His controls, E and F, were to determine if the process of inactivation or removal of native complement from the two serums was complete, and the total absence of hemolysis showed that it was. His control on the anticomplementary action of the antigen was also included in tube D, for if the emulsion alone had absorbed complement to any degree, hemolysis would have been incomplete. fix complement with various lipoidal and bacterial antigens in a non-specific manner. Schilling and Hoesslin1 were probably among the first investigators to note this phenomenon with normal rabbit serum. Manteufel and Woithe2 and Browning and McKenzie3 have also noted the phenomenon during studies in experimental trypanosomiasis. Dohi4 examined the sera of 74 normal rabbits, using as antigen an alcoholic extract of syphilitic liver, and found that 39 reacted positively and 35 negatively. He also observed that heated serum was more likely to show this nonspecific absorption of complement than unheated serum. Browning and McKenzie, however, state that they have not observed this 'phenomenon when using serum in a fresh, or active, condition. Blumenthal5 has likewise observed positive reactions with normal rabbit serum, using an alcoholic extract of syphilitic liver as antigen; Craig and Nichols,6 on the other hand, have reported uniformly negative results with an alcoholic extract of syphilitic liver. Similar observations on this power of normal rabbit serum to absorb complement in the presence of lipoidal antigens have been made by Emmanuel7 and by Epstein and Pribram,8 the former stating that the administration of salvarsan removes this property temporarily, and the latter making similar claims for the mercurials. Casselman and I9 observed a large percentage of positive reactions with the sera of 117 normal rabbits and various lipoidal extracts used as antigens in the Wassermann reaction. In a further study by Miss Trist and I10 we found that while heated rabbit serum yielded positive reactions with 38 to 49 per cent, of sera with lipoidal antigens, active or unheated sera yielded but 5-15 per cent, positive reactions. Bacterial antigens yielded even higher percentages of positive reactions. Pearce and I11 have also found that the sera of animals reacting positively or negatively generally continue to react in the same manner over long periods of observation. Rossi,12 Miss Trist and I13 have also found that the sera of a large percentage of normal dogs tends to yield non-specific fixa- tion with various lipoidal and bacterial antigens. The mechanism of this phenomenon is not understood; it would appear that the complementabsorbing body is in both the serum lipoids and proteins.1 Heating these sera at 56° C. for half an hour greatly increases their property for non-specific fixation of complement; heating at 62° C. for the same period lessens the tendency.2 The subject is of great importance in view of the frequency with which complement-fixation studies are conducted with rabbit, dog, and mule sera. Quantitative Factors in Complement-fixation Tests. — From what has been said it will, therefore, readily be appreciated that complementfixation tests are largely quantitative. Equally fallacious results may be obtained by using too large or too small amounts of the various ingredients. While it is possible to use too large quantities of antigen, so that non-specific absorption of complement occurs, leading to false positive reactions, it is also possible to use an amount so small that any specific absorption of complement by antigen and antibody cannot readily be detected. The same is true, but to a much less extent, of the immune serum, for while too large amounts of serum may lead to non-specific fixation of complement, surprisingly small amounts may give well-marked specific fixation, this factor depending, of course, upon the quantity of antibodies contained in the serum. Of even greater importance are the quantity of complement employed and the proper adjustment of the hemolytic system, composed of complement, hemolysin, and corpuscles. Too large an amount of complement may furnish sufficient to satisfy the amboceptors of an immune serum united with the antigen, with enough free complement left over to produce partial or complete hemolysis when corpuscles and hemolysin are subsequently added. In this manner specific complement fixation would be overlooked and a false negative reaction secured. It is also possible to use too small an amount of complement, with relatively large doses of serum and antigen, so that the complement becomes unduly susceptible to non-specific fixation and consequently false positive reactions may be secured. It has previously been explained that an excess of hemolysin may offset any slight deficiency in the amount of complement. For instance, if a small amount of complement is specifically fixed by an antigen and its amboceptor, the addition of too large an amount of hemolysin may result in complete hemolysis of the corpuscle, and thus overshadow the slight but specific fixation of complement. On the other hand, hemolysis cannot be complete if the dose of amboceptor is too small. With a given dose of corpuscles and complement a certain amount of hemolysin is necessary to produce hemolysis, this dose being determined by a process of titration, as described in a previous chapter. If less than this dose is used, but the amounts of corpuscles and complement remain the same, hemolysis will be correspondingly incomplete and lead to false positive reactions. A very important feature of all complement-fixation tests will be seen to be a proper and accurate adjustment of the hemolytic system. Taking arbitrary amounts of corpuscles and hemolysin as constants, the quantity of complement necessary to produce hemolysis may be determined (titration of complement); or, taking corpuscles and complement as constants, the amount of hemolysin necessary to effect complete hemolysis may be determined. One or the other or both titrations should be made before the main test is attempted, in order to avoid using an excess or too little of either ingredient. If the exact unit of complement and hemolysin are used, the results must be very carefully guarded, because in a general way all antigens and serums exert a slight anticomplementary action that may yield results that will be interpreted as weak positive reactions. For this reason the original complement-fixation tests invariably called for a slight excess of complement or hemolysin or both, to allow for possible non-specific complement fixation, and this is a good general rule that makes the reaction somewhat less delicate, but more reliable in the long run, especially for inexperienced workers. Complements of different species of animals act differently in activating a hemolytic amboceptor and toward fixation by antigen-antibody combinations. For instance, a complement from one animal may readily enough combine with a hemolytic amboceptor to produce hemolysis, but will not lend itself for fixation, and is, therefore, unfit for complement-fixation tests. Noguchi and Bronfenbrenner have found guineapig serum most suitable from all standpoints, but it is important to remember that the complementary activity of the serums from different guinea-pigs varies, and, therefore, it is necessary to titrate each complement serum or hemolysin, i. e., adjust the hemolytic system, before the main test is conducted. any complement-fixation method, but efforts to circumvent or ignore them are likely to lead to errors in technic. A proper understanding and appreciation of these factors constitutes the basis for reliable work, whereas less essential details may be altered to conform to the ideas and convenience of the individual worker. may serve two primary purposes: 1. With a known antigen, the antibody may be found. This is the usual order in diagnostic tests. For example, in the reaction for syphilis the antigen is furnished and the antibody sought for in the body-fluids. So specific has this test proved in the diagnosis of this disease that a positive reaction secured with a proper technic is regarded as strong evidence of the existence of lues, even though the primary lesion had occurred years before and the person is at the time in apparent good health. In the gonococcus fixation test and other tests of a similar nature the antigen is known and is furnished, and the antibody is tested for in the serum. 2. With a known antibody the corresponding antigen may be found. This order of events has less practical application, and is used principally in the diagnosis of blood-stains and in the differentiation of proteins in general. It is also used in making special bacteriologic investigations, when an organism may be identified by specific complement fixation with its known antibody serum. In these instances the antibody serum is secured by immunizing rabbits with a known antigen, the immune serum then being used for selecting the antigen in unknown substances and mixtures. Complement-fixation methods have their greatest value, and are probably best known, in the serum diagnosis of syphilis — the biologic syphilitic reaction of Wassermann, Neisser and Bruck, and Detre. Although originally believed to be a direct application of the specific Bordet-Gengou phenomenon of complement fixation, subsequent investigations have shown that the antigen need not be specific, in the sense of containing the Spirocheta pallida, but that lipoidal substances in general may serve as "antigen," the peculiar and specific character of the reaction depending upon the nature of the antibody, which has a strong affinity for lipoids, and in such a mixture is capable of absorbing or fixing a considerable amount of complement. In no other disease has the method been so widely employed as in syphilis, although it possesses value in the serum diagnosis of various bacterial infections, such as gonorrhea, glanders, typhoid fever, echinococcus disease, etc., and in the diagnosis of blood-stains and in the differentiation of proteins in general. In the following chapter the Wassermann syphilitic reaction will be considered in some detail, as a thorough working knowledge of this test is of great value, and serves as the foundation of complement-fixation technic in general. THE WASSERMANN REACTION IN SYPHILIS Historic. — Following Bordet's important discovery of complement fixation no practical applications were made for several years until Neisser and Sachs continued Gengou's studies on protein antigens and amboceptors, and advocated complement fixation as a fine and delicate method of control on the precipitin test in the detection and differentiation of minute traces of proteins, as in the recognition and diagnosis of blood-stains. Encouraged by these results, Wassermann used the method in an attempt to discover in the blood-serum, during the course of an infection, the bacterial proteins derived from a microorganism. Practical application proved, however, that enough of these proteins did not exist free in the blood to give definite complement fixation. In 1905 Wassermann and Bruck found that bacterial extracts may be substituted for emulsions of bacteria as antigen in performing the Bordet-Gengou test, and that extracts of diseased organs containing large numbers of bacteria or their products may be employed. Accordingly, these observers prepared aqueous extracts of tuberculous lungs and glands and used them as antigens in the study of complement fixation in tuberculosis. Positive reactions were secured with an antituberculous serum and with the serums of persons who had received injections of tuberculin. At this time Schaudinn and Hofmann discovered the spirochete of syphilis, a finding that served to focus the attention of the medical world upon this disease. In cooperation with Neisser, who was conducting extensive researches on experimental syphilis in monkeys, Wassermann and Bruck applied the complement-fixation method to the study OP these experimental infections, and published a report of their work on May 10, 1906. At first monkeys were immunized with aqueous extracts of human chancre, condylomata, syphilitic placenta, etc., and their serums, mixed in vitro with these extracts, were found to give the complement- fixation reaction. Since these results may have been due to protein amboceptors or precipitins produced simultaneously by the injection of human serum contained in the extracts, the experiment was carried out with extracts of bone-marrow and other organs of syphilitic monkeys used to obviate this error. It was found, however, that the inactivated serums of syphilitic monkeys reacted positively with antigens of either human or monkey lesions, and regardless of whether the monkeys had been injected with human extracts, since, after ordinary cutaneous infection, their serum would show complement fixation. These early reports also showed a high specificity for complement fixation, as monkey immune serum did not react with extracts of normal organs or normal monkey serum with extracts of syphilitic organs. Just fourteen days after Wassermann, Neisser, and Bruck published their report, a second paper on the same subject appeared, showing the work of Detre. Using aqueous extracts of luetic papules, liver, pancreas, and tonsillar exudate as antigens, Detre performed the complement-fixation method with the serums of six syphilitic and four normal persons, finding positive reactions with two of the six luetic serums. In 1906 Wassermann and Plaut studied the cerebrospinal fluids of 41 cases of paresis, and found positive reactions in 32, 4 cases reacting doubtfully and 5 negatively. In the following year Levaditi and Marie and Schutze observed positive reactions with the cerebrospinal fluid of tabetics, whereas Morgenroth and Stertz confirmed the previous finding in paresis. Since then numerous investigators have corroborated these observations, and while all the evidence tended to strengthen the belief in the luetic origin of general paralysis and tabes, decisive confirmation was lacking until Noguchi and Moore, in 1913, demonstrated the presence of the Treponema pallidum in sections of the cerebral cortex. In 1906 Wassermann, Neisser, Bruck, and Schucht applied the complement-fixation test to a large number of cases of syphilis in Neisser's clinic. Aqueous extracts of luetic liver, placenta, glands, chancres, and gummata were used as antigens. Of 257 cases in all stages of the disease, only 49 reacted positively. With but 19 per cent, positive reactions, the method did not appear to have a promising future, although at the present time, with a better understanding of the technic and of the importance of quantitative factors that greatly influence the results, the value of the test has been greatly enhanced. As it appeared that, after all, no method of diagnosis was to be secured as the result of the demonstration of the syphilitic antibody in the body-fluids, Neisser and Bruck determined to return to earlier methods and attempt to discover if luetic antigen could be demonstrated in the serums of luetics through complement fixation. Antigens prepared of the red corpuscles of syphilitic persons gave positive reactions with the serums of highly immunized monkeys. Of 160 luetic patients, in 70 per cent, either antigen or antibody was found. Later, however, Citron showed that the extracts of corpuscles of normal persons yielded similar results, which, in the light of subsequent discoveries, was due to their content in lipoidal substances. Up to this time the syphilitic reaction was considered as but a simple and direct application of Bordet's phenomenon, requiring a specific syphilitic antigen before complement could be fixed with the syphilis antibody. In January, 1907, Weygandt reported that he had obtained a positive reaction in tabes with an extract of normal spleen. Marie and Levaditi, using an aqueous extract of normal fetal liver, secured positive reactions with the cerebrospinal fluid of paretics, but observed that it was necessary to use larger doses than when extracts of syphilitic organs were used. Subsequently other investigators, as, for example; Fleischmann, Michaelis, Landsteiner, and Plaut, found that watery extracts of normal organs served to fix the complement with luetic antibody. Finally, in December, 1907, a profound impression was created by the discovery made by Landsteiner, Mtiller, and Potzl, that an alcoholic extract of guinea-pig heart yielded results equal to those obtained with an aqueous extract of syphilitic liver. These results indicated that the antigenic principle was soluble in alcohol, and a prolonged series of investigations on the various lipoids and their relation to the reaction was begun. These included the employment of lecithin by Forges and Meier; sodium taurocholate and glycocholate by Levaditi and Yamonouchi; cholesterin and vaselin by Fleischmann; oleic acid by Sachs and Altman; acetone-insoluble fractions of alcoholic extracts by Noguchi; and many other combinations of various lipoidal substances by different investigators. These dealt a blow to the theory of the Wassermann reaction, which, taken in conjunction with the wide-spread use of the test by inexperienced and unskilful persons and the many sources of error, tended to retard an earlier appreciation of the great value of the test, and served to swing the pendulum of medical opinion so far in the wrong direction that it is only now, with a better understanding of its possibilities and limitations, that the method is being established in its proper sphere. Positive reactions were said to have occurred in frambesia, leprosy, malaria, pellagra, pneumonia, scarlet fever, typhoid fever, malignant tumors, and practically every other disease liable to afflict humanity. The careful work of Citron was largely instrumental in preserving the importance of the reaction until a better understanding of the technic resulted in improved and more careful work, with a greater respect for the real value of the Wassermann reaction. Although the true explanation of the mechanism of complement fixation in syphilis is still lacking, sufficient work has been done to show that the specific nature of the reaction is dependent upon a peculiar luetic antibody, and that the older belief in the specificity of antigen, in so far as it insisted upon the presence of the Treponema pallidum in the tissues extracted for "antigen," is largely disproved. While the method cannot be said to be absolutely diagnostic of syphilis, since positive reactions were had in frambesia (yaws) and leprosy, yet it is practically so, especially in those countries where these two infections are unknown or are relatively infrequent. Principles and Theories of the Syphilitic Reaction. — The discovery that the antigen in the Wassermann reaction is not necessarily biologically specific, but may be furnished by a variety of different lipoids1 from normal or syphilitic tissues, opened up an entirely new phase of the well-known theory of complement fixation, and separated the syphilitic reaction from the classic Bordet-Gengou phenomenon, as based upon the absorption of fixation of complement by a specific antigen and its antibody. As is now well known, the lipoids have always been chiefly concerned in the reaction, although Wassermann and Detre and their coworkers naturally ascribed the complement-fixing powers of their extracts to the presence of the Treponema pallidum. It is, indeed, fortunate that pure cultures of the treponema were not available at the time the original studies were made, for these would naturally have been employed as antigen, and as subsequent work with pallidum antigens has shown complement fixation to be quite irregular and less reliable than when lipoidal extracts are used, this result, coupled with the imperfect understanding and faulty technic of the earlier investigations, would probably have yielded results so discouraging as to constitute weighty drawbacks to the full development of the reaction. theories advanced tend to show. While lipoidal extracts, as well as normal and luetic serums, may separately absorb or fix small amounts of complement, a mixture of a suitable extract and syphilitic serum is capable of fixing large amounts of complement, and this constitutes the main principle and all that is definitely known of the syphilitic reaction. The serum of a syphilitic is characterized, therefore, by the presence of this lipodotropic, antibody-like substance, which has a great affinity for lipoids and in mixture with them will cause the absorption or fixation of complement to a well-marked degree. Instead of being an example of complement fixation in a mixture of specific antigen with specific antibody, as originally believed, it is technically a non-specific reaction, but practically it is highly specific, since this peculiar antibody is found in largest amount and most constantly in syphilis, and to a lesser extent in practically only two other diseases, namely, leprosy and frambesia. In countries and districts where these diseases are infrequent or unknown with proper technic the reaction for syphilis is highly specific. As will be shown further on, the presence of this lipodotropic substance is dependent upon the activities of the Treponema pallidum, and when repeated tests continue to show its presence, there is every reason to believe that a cure has not been effected, but that the patient still harbors the living parasite. Citron has advanced the hypothesis that the antibody-producing antigen is a toxolipoid, which would explain the fact that while pure lipoids, such as lecithin, cannot stimulate antibodies (Bruck), as the toxolipoid does, they can, nevertheless, react with the lipodotropic antibodies in vitro, with fixation or absorption of complement. As Sachs and Altman point out, an equally tenable theory would be that in syphilis the tissues undergo such alterations that they can produce antibodies to the lipoid substances as may be contained in the spirochetes themselves. While the production of this lipodotropic antibody is still unexplained, the fact remains, nevertheless, that it forms the basis of the biologic syphilitic reaction, and in a mixture with a suitable lipoid is capable of absorbing or inactivating complement to a marked degree. Whether or not it is a true antibody in the sense that it is inimical to the spirochete is doubtful; by many it is regarded as a secondary product of cellular activity, and has been called syphilis "reagin." the isolation of the Treponema pallidum in pure culture, believing that if this result were secured it would be possible to work with a specific antigen, determine the nature of the true syphilis antibody, and possibly establish a complement-fixation test specific for syphilis. In 1909 Schereschewsky,1 using an antigen of an impure and nonpathogenic culture of a spirochete regarded as the Treponema pallidum, reported positive complement-fixation reactions with the majority of serums tested. In 1912 Noguchi,2 having undoubtedly isolated the spirochete in pure culture, prepared antigens and found that, whereas certain longstanding or treated cases of syphilis yielded positive reactions with the pallidum antigens, the reactions were uniformly negative when the lipoidal extracts were used. In primary and secondary syphilis the reactions with pallidum antigens were uniformly negative, whereas with the lipoidal extracts they were uniformly positive. As a result of his experiments Noguchi concluded that in syphilis there is produced a true antibody that reacts specifically with pallidum antigen, in addition to the lipodotropic "reagin," which reacts with lipoidal extracts, and whereas the latter indicates activity of the infecting agent, the former is a gage of the defensive activity of the infected host. Craig and Nichols,3 using alcoholic extracts of pure cultures in ascites kidney agar of Treponema pallidum, Spirochete pertenuis, and Spirochete microdentium, found similar positive reactions in all stages of syphilis with the three antigens, but the reactions were weaker and less constant as compared with those obtained with a stock of lipoidal extract. Similar studies conducted by Kolmer, Williams, and Laubaugh4 with aqueous and alcoholic extracts of pallidum cultures showed positive reactions in secondary, tertiary, and congenital syphilis. The aqueous extracts yielded better reactions than the alcoholic extracts; in practically all instances, however, the reactions were weaker than those obtained with the ordinary lipoidal extracts. Control antigens of typhoid and cholera bacilli and sterile culture mediums demonstrated that all contained lipoidal substances that may give weak reactions with the lipodophilic " reagin." This may explain Schereschewsky's positive reactions with an antigen of a spirochete that in all probability was Spirochete microdentium (Noguchi). be said to have been determined. It is probable that the ordinary syphilis reaction is in itself not dependent upon a true antibody, and that the reaction is not an immunity reaction, but due rather to the presence of peculiar tissue products (reagins) altered by the presence and activities of the spirochetes themselves, and that the Wassermann reaction is an expression of this active injury to tissue-cells. In addition to this secondary product there is probably a true syphilis antibody that may yield specific complement fixation with pallidum antigens. In so far as the Wassermann reaction is concerned, the true antibody is entirely secondary in importance, and the whole question is intimately concerned with the chemistry of lipoids. While future researches in immunochemistry may reveal the mechanism of the reaction, the principles are at least well understood at present, so that the syphilis reaction is proving of great diagnostic and practical value. TECHNIC OF THE WASSERMANN REACTION Glassware for Complement-fixation Reactions. — Test-tubes should be of convenient sizes, — 12 by 1.5 cm., — perfectly clean, free from acids and alkalis, and preferably sterile. They need not be plugged with cotton as it suffices to sterilize them in a wire basket with their mouthends downward. Smaller test-tubes, as those used in the Noguchi modification of the Wassermann reaction (8 by 1 cm.), are wrapped in newspaper in bundles of 25 and sterilized. Pipets should be perfectly clean and preferably sterile. Three kinds are required: The ordinary 1 c.c. pipet, graduated to 0.01 c.c. and calibrated to the tip; a number of special pipets for the fourth method and the gonococcus fixation test, of about the same length and external diameter as an ordinary 1 c.c. pipet, but of much smaller caliber, so that the pipet will hold 0.2 c.c. ; it should be graduated to 0.01 c.c. and calibrated to the tip; 5 c.c. pipets divided into 0.1 c.c. Care should be exercised in handling pipets to avoid breaking the tips. After use they should be washed free from blood, serum, etc. I. The Fluid to be Tested. — (a) Serum. — As a general rule, all specimens of blood submitted for complement-fixation tests should be collected aseptically in sterile containers. This is especially necessary when there has been delay in transmitting the fluid to the laboratory, as when sent through the mails from distant points. When the reactions are to be conducted on the same or on the following day, the specimen of blood may be collected in chemically clean but not necessarily sterile containers. Bacterial contamination renders a fluid anticomplementary and unfit for complement-fixation tests. Specimens should be kept on ice until used, and the serum promptly separated from the clot. for the Wassermann reaction the following points should be remembered : 1. That during active antisyphilitic treatment the blood may react negatively, whereas at a later period a true positive reaction is observed. It is well, therefore, not to collect blood until all specific treatment has been suspended for at least two weeks. the patient has a high temperature. As a general rule, at least 1 c.c. of serum and 2 c.c. of cerebrospinal fluid are required for making the syphilitic reaction. From 2 to 3 c.c. of blood are needed, these amounts being easily collected from adult .persons by pricking the finger deeply and filling a small test-tube or vial, as shown on p. 32. This method is very convenient, especially for physicians, hospitals, and dispensaries where direct access to a laboratory can be had. When the treatment is to be guided by the Wassermann reaction, a number of tests are required, and patients may object to repeated venipuncture, whereas no objections will be raised to simple puncture of the finger. Larger amounts of blood are collected from a vein at the elbow under aseptic precautions, as described on p. 33. As a rule, it is well to collect at least 5 c.c. of blood, especially if the specimen is shipped from a distant point (Fig. 108). An excess of serum permits the technician to repeat a test when necessary, or to apply more than one method, and thus at times both the physician and the patient are saved the time and annoyance incident to collecting another specimen (Fig. 109). The Keidel tube, which is sterilized and ready for use, is quite a convenience (p. 36). However, a test-tube or a centrifuge tube may be used, or, when a specimen is to be mailed, a 5 or 10 c. c. vial of thick glass, stoppered with a cork or a rubber stopper is quite satisfactory (Fig. 108). Vial, stopper, and needle are readily sterilized in boiling water, drained, and cooled, the specimen collected, the vial tightly stoppered, and the whole sent at once to the laboratory. Cotton stoppers are unsatisfactory, as unless the tube or vial is maintained in an upright position, the fluid may be absorbed. When specimens of blood are to be mailed, it is better to fill a small vial than to place the same amount in a large container, for in the latter case agitation through handling may result in so much mechanical hemolysis taking place as to render the serum unsatisfactory for use. Specimens so collected may be sent for long distances, even in warm weather, and undergo no change. In collecting blood from children, or where the veins are small, a proportionately smaller needle may be used. In infants the cupping apparatus of Blackfan is quite satisfactory (p. 36); frequently sufficient blood may be obtained from a great toe. The specimen of blood should be kept in a cold place, and the serum removed at the end of twenty-four hours. Serum that is allowed to remain with the clot for longer periods is more likely to become anticomplementary, especially if it becomes deeply tinged with hemoglobin. In cases where the serum does not separate the clot may be broken up gently with a sterile glass rod and centrifugalized. The serum should be clear and free from corpuscles. Opalescent and milky serums, obtained during the period of digestion and from nursing women, usually do not interfere with fixation of complement. It is essential that all serums be heated at 55° C. for half an hour immediately before the test is made. This exposure to heat somewhat diminishes the reacting power of a syphilitic serum, but, as shown by Seligman and Pinkus, it is a necessary procedure, for a considerable proportion of normal serums or those from diseases other than syphilis will react positively when unheated, whereas when heated, they will give a negative reaction. Furthermore, serums that are sterile and are kept for some time at room temperature or even in an ice-chest acquire an anticomplementary power that is destroyed by heating at 55° C. for half an hour. Therefore when serums are preserved for a number of days they are heated not so much for the purpose of removing native hemolytic complement, which has probably already deteriorated, but to remove thermolabile anticomplement. Serums that are old or contaminated with bacteria are likely to be highly anticomplementary, and this property cannot be destroyed The container is a centrifuge tube which holds about 15 to 18 c.c. of blood to the mark. The needle is furnished in a separate tube, sterilized and ready for use. This outfit is not adapted for mailing. by heating at 55° C. or nitration through a Berkefeld filter. In order to .conduct a reliable test it is usually necessary to secure fresh serum. This anticomplementary action of serums is so important that in every complement-fixation test there is a serum control tube containing all the ingredients except antigen, the object being to discover any inhibitory action of the serum itself upon the complement. reaction depends upon removing the excess of indifferent and inhibiting serum components and upon the destruction or diminution of the natural antisheep amboceptor present in so large a percentage of human serums. As Noguchi and Bronfenbrenner have pointed out, this method may likewise remove the antibodies concerned in the reaction. To 1 c.c. of heated serum add 3.5 c.c. of saline solution and 0.5 c.c. of a 7 per cent, suspension of freshly precipitated barium sulphate; shake, and let it stand for one hour at 37° C.; centrifugalize, and pipet off the diluted serum, which is now ready to be tested (1 c.c. = 0.2 c.c. of undiluted serum). Cadaver serums are likely to be highly discolored with hemoglobin and quite anticomplementary. Such serums may be tested in half the usual dose, and while the results are quite specific, they are not so reliable or constant as those obtained from the living. The doses of serum used in testing for the syphilis reaction are given with each method. In the original Wassermann test 0.2 c.c. was used. As a rule, from 0.05 c.c. to 0.2 c.c. of serum are satisfactory; higher doses may occasionally show a stronger positive reaction, but the serum must be perfectly fresh to avoid non-specific complement fixation, and the natural antisheep amboceptor should first be removed. (b) Cerebrospinal Fluid. — In certain nervous diseases the cerebrospinal fluid is examined for the syphilis reaction. Fluid is secured by lumbar puncture, according to the method described on p. 37. If the specimen contains blood, it should be centrifuged until it is clear. It should not be heated before use, as it does not contain hemolytic complement, and fresh fluids from cases other than syphilitics do not react positively. Cerebrospinal fluids, as a rule, possess weaker deviating powers than the corresponding blood-serum, and hence it is necessary to use larger doses — at least 0.5 to 1 c.c., instead of 0.05 to 0.2 c.c., as in the case of blood-serum. (c) Other Fluids. — Positive syphilitic reactions have been described as occurring with milk, pleural and peritoneal exudates, and albuminous urine (Bauer and Hirsh) from luetic cases. The reactions with these substances are conducted in the same manner as with Cerebrospinal fluid. The material should be perfectly fresh, as anticomplementary action is likely to occur. II. Complement. — While complement is to be found in the fresh normal serum of practically all warm-blooded animals, not all are suitable for complement-fixation tests. A suitable complement must possess two important properties: (1) Complementary activities, or the power of activating a hemolytic amboceptor, and (2) fixability, or the power of being " fixed" by antigen and antibody. Noguchi and Bronfenbrenner have studied the complements of the dog, sheep, hog, ox, rabbit, and other animals, and found that the complement of the guinea-pig was best adapted, from all standpoints, for the complementfixation test. The complements of pigs and sheep are quite fixable, but their weak hemolytic action and rapid deterioration render them unsuitable for fixation purposes. Rabbit complement is quite active, but is not easily fixable. Kolmer, Yui, and Tyau1 found rat complement fairly well suited for making the syphilitic reaction with an antihuman hemolytic system. The hemolytic power of guinea-pig complement is not constant. In unhealthy animals it is likely to be low, and even among normal animals it may show some variation. For this reason the hemolytic power of each serum is determined by a method of titration before complement-fixation reactions are conducted. Fixed doses of hemolysin and corpuscles may be used, and the amount of complement necessary for effecting complete hemolysis may be determined, or a fixed dose of complement and corpuscles may be used with different amounts of hemolysin, the chief object being to adjust all three factors of the hemolytic system, namely, complement, corpuscles, and hemolysin, to exact and known proportions. The complement in the serums of different guinea-pigs may show considerable variation in fixability. The amount of complement inhibited by serum alone and organic extract alone, or by given constant quantities .of serum and extract, may vary more markedly than their complementary activity. To reduce this error to a minimum it is advisable, whenever possible, to use the pooled serums of two or more pigs for making complement-fixation tests. Guinea-pig complement serum is collected by bleeding the animal, under ether anesthesia, into a Petri dish or centrifuge tube. The large vessels on both sides of the neck are quickly severed with a pair of sharp-pointed scissors or a scalpel, care being exercised not to sever the trachea and esophagus. A funnel is used for collecting blood in centrifuge tubes. It is well finally to sever the spinal cord, in order that the animal may not recover from the anesthetic and thus insure a painless operation throughout. (See p. 46.) until coagulation has occurred and the serum has separated; then place the whole in the ice-chest until needed. Blood may be collected in centrifuge tubes and allowed to coagulate; it is then broken up with a glass rod, centrifuged, and the serum secured at once; such complement, however, is likely to be unduly hypersensitive to the anticomplement action of organic extract and of mixtures of extract with normal serums. As a general rule, therefore, it is good practice to bleed the animal late in the afternoon preceding the day on which the experiment is to be made, or at least some hours before the regular work of the day begins. The serum should be clear and contain no corpuscles. Preservation of Complement.— Various methods have been advocated from time to time for the preservation of complement serum. Serum kept in a frozen state will preserve its complement properties over a period of several weeks. In my own experience, complement serum is best preserved with chemically pure sodium chlorid. The sera of several guinea-pigs are secured and mixed, and 0.425 gram sodium chlorid dissolved in each 10 c.c. This serum is best preserved in the refrigerator, sealed in amounts of 1 c.c. in ampules; before use each cubic centimeter is diluted with 19 c.c. of distilled water, making a 1 : 20 or 5 per cent, dilution ( = 0.05 c.c. undiluted serum) in 0.85 per cent, salt solution. If a 1 : 10 dilution (= 0.1 c.c. undiluted serum) is desired, 0.85 gram sodium chlorid should be added to each 10 c.c. of serum and each cubic centimeter diluted with 9 c.c. of distilled water. Complement serum preserved in this manner will maintain its hemolytic and fixing properties for several weeks; loss in fixability or delicacy in the complement-fixation test is usually apparent before an appreciable deterioration in hemolytic activity. And now we come to a very important question, namely, the amount of complement that is to be used in conducting complement-fixation tests. Many present-day observers use exactly one unit of complement and one unit of amboceptor. This is permissible, providing the complement is titrated in the presence of a constant dose of antigen and a constant dose of serum, in order that due allowance for the anticomplementary action of these may be made in the titration. Under these circumstances, however, it is necessary to titrate each patient's serum with the complement, because one serum or even the pooled serums of different persons should not be taken as a standard in the titration, for two important reasons: (1) The patient's serum which we are about to test may t}e more anticomplementary than the serum used in the complement titration, and hence when used in the main test, with exactly one unit of complement, mild degrees of inhibition of hemolysis will be secured that may be interpreted as slightly positive reactions; or (2) the serum used in the complement titration may contain more or less natural hemolytic amboceptor than the patient's serum, and this factor exerts an influence on the titration, so that the unit varies with different serums. For these reasons I have included here a fourth method for using a single unit of complement under conditions where the anticomplementary action of each serum and the antigen are determined, in preference to titrating the complement with a serum and using this unit for a number of other serums that are sure to differ from each other. In this titration, therefore, we determine the amount or unit of complement necessary to produce hemolysis with fixed amounts of amboceptor and corpuscles. It will be observed that I have used two units of amboceptor, as determined by a previous titration. These two units are equivalent to one dose, and the same would be true whether three, four, five, or more units were used, because in this titration the corpuscles and amboceptor are arbitrary and fixed constants, and are used for determining the amount of complement necessary to bring about complete hemolysis. In conducting the main tests the dose of corpuscles and that of amboceptor are the same as those used in the complement titration, but instead of using exactly one unit of complement, it is necessary to use one and one-half or two units, to allow for the anticomplementary action of antigen and patient's serum. As the result of a large number of comparative titrations and tests I have found that 0.05 c.c. of complement serum ( = 1 c.c. of a 1:20 dilution) is a safe amount to use with 2.5 per cent, corpuscle suspension, and equally good results are secured by adopting this amount as a fixed dose in titrating the amboceptor before each day's work. If the pig serum happens to be weaker or stronger in complement than it is expected to be, the differences are adjusted in the amboceptor titration. Following the same rule, one and one-half or two units of amboceptor are used in conducting the main test, the extra half, or one unit, overcoming the anticomplementary action of antigen and patient's serum. It is important to remember that, in conducting this titration, amboceptor, complement, and corpuscles are to be mixed at once; if amboceptor and corpuscles are mixed and allowed to stand for ten minutes or more before receiving the complement the corpuscles become "sensitized," and the amount of complement required for effecting hemolysis will be less than if all three are mixed one after another. If this rule is not adhered to, an error in technic may result. HI. Hemolytic Amboceptor. — Since the original work of Wassermann appeared, the antisheep hemolytic system has been most widely used in experimental investigations. Antisheep amboceptor is readily prepared by immunizing rabbits with washed sheep's corpuscles. A simple and efficient method is to give intravenous injections of four doses of 5 c.c. each of a 10 per cent, suspension every three or four days. Other methods and the details of the preparation and preservation of amboceptor are given in Chapters IV and V. The one objection to the use of the antisheep hemolytic system is the presence, in a large proportion of human serums, of variable amounts of natural amboceptor for sheep's cells. In about 70 per cent, of fresh inactivated human serums sufficient amboceptor is present partially or completely to hemolyze the usual dose of sheep-cell emulsion with the customary amount of guinea-pig complement. In fact, the Bauer and Hecht modifications of the Wassermann reaction utilize this natural amboceptor, but, as will be pointed out further on, this factor is too variable to be employed in conducting the reaction, as non-specific or false positive results are quite likely to occur. As has been stated in the preceding chapter, the delicacy and accuracy of any complement-fixation test depend to a large extent upon proper adjustment of the hemolytic system. It will readily be understood that the presence of an unknown quantity of natural amboceptor in a serum is a drawback to accurate quantitative estimations. The importance of this lies in the fact that for some unknown reason an excess of amboceptor may completely hemolyze the corpuscles, even though a small amount of the necessary complement has been specifically fixed by antigen and syphilis antibody. In this manner negative reactions may result with serums that would otherwise show a slight positive reaction. To remove this source of error Noguchi has advocated the use of an antihuman hemolytic system, which renders the reaction more delicate. However, comparative studies between antisheep and other hemolytic systems demonstrate that, with proper technic, the influence of natural amboceptors may be reduced to a minimum and rendered almost neg- ligible. At any rate it is very simple and but little trouble to remove the antisheep amboceptor routinely from human serums previous to making the tests (for technic, see p. 400) . A method for titrating immune amboceptor has been given on p. 397. This important feature will be dealt with again in giving a detailed description of the various methods that follow. In the original Wassermann reaction a 5 per cent, suspension in salt solution is used in doses of 1 c.c. This emulsion is quite heavy, and sharper and clear results are secured by using just half this amount and at the same time sufficient cells are used to make the readings easy and distinct. Either 0.5 c.c. of a 5 per cent, or 1 c.c. of a 2.5 per cent, suspension may be used. I have used the latter with entire satisfaction for several years. The emulsion of cells is prepared with sterile 0.85 per cent, sodium chlorid solution. To 2.5 c.c. of corpuscles sufficient salt solution is added to bring the total volume of the emulsion up to 100 c.c., or smaller amounts may be prepared by suspending 1 c.c. of corpuscles in 39 c.c. of salt solution. Before each day's work the amount of corpuscle suspension needed should be calculated, and sufficient for the day prepared at one time, for if a fresh emulsion is prepared later, titration with the complement and amboceptor would be required. Attempts to count the corpuscles in suspension can only be regarded as approximate and are unreliable. By titrating each emulsion with the complement and amboceptor to be used, that particular emulsion is thereby adjusted, so that it is immaterial whether a few more or a few less corpuscles are present. Sheep's blood is obtained either from an abattoir or by bleeding an animal from the external jugular vein (p. 48). The latter method is preferable, but due care must be exercised not to bleed too frequently or in excessive amounts, as if anemia occurs the corpuscles become unduly fragile. Sheep's cells are easily preserved in a satisfactory condition for forty-eight hours by first washing them and then storing the sedimented corpuscles in a good ice-chest. Suspensions are less easily preserved. It is best to use fresh corpuscles, and those that are several days old and unduly fragile should never be used. Attempts to preserve corpuscles with the aid of mercury bichlorid, formalin, etc., have not yielded satisfactory results. V Antigen. — As was previously stated, the ordinary alcoholic extracts of syphilitic livers used as " antigens" in conducting the Wassermann reaction are not biologically specific. It is generally accepted that even in watery extracts of syphilitic livers the main antigenic principles are lipoidal substances, independent of the Treponema pallidum itself. Next to pure cultures of pallida, these aqueous extracts of luetic livers come closest to being a specific biologic antigen. Although alcoholic extracts of luetic liver may contain special lipoidal substances that enhance their efficacy as antigens, yet, as shown by Noguchi, and as confirmed later by us, alcohol does not serve well to extract pure cultures of pallida, and therefore these extracts can hardly be regarded as specific, in the sense that they contain antigenic principles of the spirochetes themselves. The only specific biologic antigen is an aqueous extract of a pure culture of pallida; this antigen is, however, much less serviceable than an ordinary organic extract, because the Wassermann reaction depends upon the peculiar lipodophilic "reagin," which absorbs complement with lipoids in a characteristic but biologically non-specific manner. The term " antigen," as ordinarily used in the Wassermann reaction, must therefore be regarded as a misnomer. It is, however, so generally used that it may be retained, with a distinct understanding as to its actual meaning. With the discovery that alcoholic extracts of normal organs may serve as antigen and that the chief antigenic principles reside in the lipoids, it followed that extensive researches were undertaken in the hope of discovering a lipoid, or a combination of lipoids, that would prove sufficiently delicate to act specifically in the serum diagnosis of syphilis, and not with normal serums or those of persons suffering from other diseases. As a result, a large number of different extracts are in use. Each has its own advocates, so that the general subject of antigens is the most complicated one with which we have to deal in performing the Wassermann reaction. shown that some are better than others. It is important to remember: 1. That all antigens are capable in themselves of absorbing a certain, amount of complement. This is due to the presence of undesirable extractives, some preparations containing more than others. In certain doses, however, all antigens are capable of exerting this anticomplementary action, and, other things being equal, that antigen is best which shows this non-specification in the smallest degree. Before an antigen may be used in conducting any complement-fixation test it is necessary to ascertain its anticomplementary dose, for if this dose were used, a portion of or all the complement would be fixed in a non-specific manner, so that hemolysis, being partial or absent, yields false positive reactions. j 2. Most antigens, when in sufficiently large amounts, are hemolytic, \/ i. e., they may hemolyze corpuscles in a non-specific manner. This hemolytic action is usually due to the presence of undesirable extractives, and extracts of organs that have undergone advanced autolysis or fatty degeneration are known to contain more of these hemolytic substances than do extracts of normal organs. As a general rule, a highly anticomplementary antigen is likely to be correspondingly highly hemolytic. The hemolysis may be due to the presence of lipoidal substances or to the alcohol used in preparing the extract. If an antigen were used in an amount equal to its hemolytic dose, partial or complete hemolysis would occur in all tubes, so that a false negative result would be secured. As a rule, the hemolytic dose of an antigen as determined by titration in the presence of serum is larger than the anticomplementary dose, so that if the latter is known, it is not always necessary to determine the former. . 3. Practically every alcoholic organic extract will serve, in certain v amounts, to absorb complement in the presence of the serum of a syphilitic person. Some extracts, however, will do this better than others. The Wassermann reaction depends upon the fact that a larger amount of complement is fixed by the syphilis antibody and extract than is fixed by normal serum or the serum of a person with some disease other than syphilis and this same extract. The only two notable exceptions to this general rule are to be found with the serum of tuberous leprosy and that of frambesia. The amount of antigen that is found, by a process ofv> titration, to fix a large amount of complement with a constant dose of syphilitic serum is known as its antigenic dose. Not every lipoid serves equally well as antigen, and therefore considerable research work has been done in the hope of discovering an extract or a combination of lipoidal substances that would show a constant reaction and would react . only with the syphilis antibody. Thus far this has not been accomplished; unfortunately, pure pallida antigens are not entirely specific or serviceable, and if the specific and ideal antigen is discovered in the future it will probably be of the nature of a lipoidal substance, altered or produced in a specific manner by the Treponema pallidum itself. In the meantime we have antigens sufficiently delicate and specific, when properly used, to render the Wassermann reaction of great value in the diagnosis of syphilis and to serve as a guide to its treatment. least. 3. It should possess a high degree of sensitiveness for the syphilitic antibody, i. e., be capable of absorbing relatively large -amounts of complement in the presence of syphilitic serum. A good antigen is one that, in small amounts, is perfectly antigenic, and that does not become anticomplementary or hemolytic until from four to ten times this amount is used. 4. It should be quite stable and not difficult to prepare, and different preparations should bear a certain relationship to one another in their properties — that is they should keep well, and different extracts prepared in the same manner should show fairly constant antigenic, anticomplementary, and hemolytic doses. 7. Aqueous extracts of pallidum culture. 1. Aqueous Extracts of Syphilitic Livers. — This is the original antigen, as employed by Wassermann, Neisser, and Bruck; Wassermann still uses these extracts in preference to others. They may contain spirochetes or their direct derivatives, and, as shown originally by Wassermann and Neisser, may be true biologic antigens, for when injected into monkeys, antibodies are formed. No satisfactory analyses of these extracts have been made. Chemically they differ in no essential respect from the liver of acute yellow atrophy (Ehrmann and Stern; Seligman and Pinkus). As antigen they are more efficient than similar, extracts of normal liver. The nature of the specific factor has not yet been demonstrated with certainty. They react with the serums of leprosy and yaws, and, as in the case of other antigens, their main antigenic principle is apparently due to the presence of lipoids. They are less stable than alcoholic extracts, and are likely to become highly anticomplementary and lose their power of reacting with syphilitic serums. Citron is convinced that these changes are brought about by careless handling of the extract, or its exposure to the light. He recommends that the extract be kept constantly in the ice-chest, and that it be kept out only long enough to remove sufficient for the day's work. Preparation. — The fresh liver taken from a syphilitic fetus, and showing the presence of spiroehetes by dark-ground illumination, is weighed and cut into fine pieces. Four times its weight of 0.5 per cent, phenol in physiologic salt solution is added. The mixture is placed in a brown bottle and shaken mechanically at room temperature for twenty-four hours. It is then filtered through gauze, to remove the larger particles, and stored in a brown bottle in an ice-chest. After several days of sedimentation the fluid assumes a yellowish-brown opalescence and is ready for the preliminary titration to determine its anticomplementary and hemolytic doses. The sediment should not be disturbed, but the supernatant fluid should be carefully removed by means of a pipet. According to Citron, extracts that must be used in quantities of less than 0.1 c.c. are, as a general rule, unsatisfactory. Only such extracts should be used as in doses of 0.4 c.c. will not interfere with hemolysis. The method of making these titrations is given on page 452. 2. Alcoholic Extracts of Syphilitic Livers. — These antigens are extensively used. They are not true biologic antigens, for they do not give rise to antibodies (Schatilof and Isabolinsky; Seligman and Pinkus) ; they are, however, usually better antigens than similar extracts of normal liver, a fact that may be explained, in part at least, by chemical changes, namely, fatty changes, autolysis, soaps (Beueker), excess of cholesterin (Piglini), etc., which, while not specifically syphilitic in nature, are often produced to a striking degree in congenital syphilis. Preparation, — Fetal liver known to contain numerous spiroehetes is used in preparing this extract. Fresh organs may be examined at once by dark-field illumination, or if this is impossible and the fetus shows signs of syphilis, the liver may be cut into large pieces and preserved in 70 per cent, alcohol. After a few days a section is removed and stained by the Levaditi method for spiroehetes. If these microorganisms are numerous, the liver is suitable for preparing the antigen; otherwise it should be discarded. Very fatty livers are to be avoided, and those of still-born fetuses are to be preferred. Ten grams of liver are minced, ground with quartz sand, and treated with 100 c.c. of absolute ethyl alcohol. The mixture is shaken mechanically with glass beads for twenty-four hours, and extracted in the incubator for ten days. The containing flask or bottle should be well stoppered to prevent undue evaporation, and should be shaken up at least once a day. The extract is then filtered through fat-free paper or paper washed with ether and alcohol to remove the hemolytic substances that may be present. The filtrate is measured, and the loss by evaporation is made up by the addition of more alcohol. If a shaking apparatus is not at hand, extractions may be left in the incubator a few days longer. After standing a few days a sediment forms, which should not be removed or disturbed. 3. Alcoholic Extracts of Normal Organs. — These are used extensively, at present, and apparently yield results equal to those obtained with extracts of luetic liver. It is certainly true that a good extract of a normal organ is superior to a poor one prepared from luetic liver. Many, with the idea of specificity uppermost in their mind, adhere to the use oi the latter, whereas the results of research and of practical work shows that lipoids from normal organs serve equally well as antigen in making the syphilitic reaction, and, indeed, may prove superior if luetic liver is used that has undergone advanced fatty changes or autolysis, when undesirable hemolytic and anticomplementary derivatives are extracted in excess. The first is especially efficient and is to be preferred. Preparation. — The organ is obtained fresh from the autopsy room. It is freed from fat, and to each 10 grams of minced muscle 100 c.c. of absolute ethyl alcohol are added. Extraction is conducted in exactly the same manner as was described in the preparation of alcoholic extract of luetic liver. otherwise the extract may be quite anticomplementary. Boas prepared an extract of human heart by treating the ground muscle with nine parts of absolute alcohol, shaking for an hour at room temperature, filtering, and storing away in a stoppered bottle. He found that different extracts so prepared are remarkably constant in their properties, although they deteriorate rapidly and should be prepared freshly every few weeks. 4. Alcoholic Extracts of Normal Organs Reenforced with Cholesterin. — Sachs advocated the addition of pure cholesterin to alcoholic extracts of normal heart as a means of rendering these antigens more delicate, without materially increasing their anticomplementary and hemolytic properties. He found that such preparations possess properties equal to the best syphilitic extracts. This work has been confirmed by Hemlein, Altman, Mclntosh and Fieldes, Desmonliere, Walker, and Swift. We have studied the subject with much interest, comparing the results with those secured from other antigens, as alcoholic extracts of syphilitic liver and acetone-insoluble lipoids. It is true that these preparations are highly sensitive — so much so that I never employ them alone in making diagnostic reactions, but always in conjunction with other extracts as controls, in order to detect and avoid non-s'pecific reactions with non-luetic serums. We have found that they occasionally give faint positive reactions with normal serums; on the other hand, not infrequently, they react strongly positive in cases where, with other extracts, the reactions are negative; in the majority of such cases the serum is from a long-standing or a treated case of lues that needs further treatment until the reaction with a cholesterin extract becomes negative. These alcoholic extracts of normal organs have their greatest value, therefore, with known syphilitic serums when the reaction is conducted as a guide to treatment. In diagnostic reactions, however, it is my opinion that they should not be used alone, but together with less sensitive antigens. In other words, one should use every precaution and exercise great care before making a diagnosis; when lues is known to be present, however, the treatment should be thorough, and there would seem to be no better criterion for judging the state of the infection than repeated negative reactions with cholesterin extracts. Preparation. — These extracts are prepared of human, ox, and guinea-pig heart. Human heart usually yields the best extract. Care should be taken to use only muscle and to avoid fat. To 10 grams of minced muscle add 100 c.c. of absolute ethyl alcohol. Shake in a mechanical shaker for twenty-four hours, and continue the extraction in the incubator for ten days or two weeks. Then filter through fatfree filter-paper, and add absolute alcohol to make up for the loss through evaporation. Add 0.4 gram of Kahlbaum's cholesterin (0.4 per cent.); shake well and stand aside in the refrigerator for a few days. The cholesterin goes into solution slowly in cold alcohol, and 0.4 per cent, of cholesterin usually saturates the solution. After a week the extract may be again filtered and stored in a tightly stoppered bottle. The slight sediment that may form should not be disturbed. These extracts keep fairly well. Different preparations are quite similar in their properties; they are usually found to be highly antigenic and no more anticomplementary than crude alcoholic extracts. They constitute, therefore, inexpensive and very sensitive antigens. 5. Acetone-insoluble Lipoids. — As previously stated, crude alcoholic extracts may contain an excess of undesirable constituents, such as neutral fats, fatty acids, soaps, and certain protein materials, which are responsible for the untoward anticomplementary and hemolytic effects. To eliminate these Noguchi advised the exclusive use of the acetone-insoluble fraction instead of the entire unfractionated alcoholic extract, especially if unheated human serums are used in conducting the syphilis reaction. These extracts are composed essentially of lecithins, which, when prepared from any one source, consist of a mixture of analogous bodies; lecithins from different sources vary in their composition. In speaking of lecithins, one is prone to regard them as chemicals, and to overlook their biologic properties. Noguchi no longer employs the term lecithin to designate the acetone-insoluble fraction of tissue lipoids. These antigens are readily prepared of ox-heart or of human liver, the former being preferable for use. Their main disadvantage is the expense of preparation, for it may be necessary to prepare several extracts before one that is satisfactory is secured. A good extract will, however, keep well, and is a reliable and valuable antigen for the testing for the syphilitic reaction. Preparation. — A mashed paste of the muscle of ox-heart is extracted with 10 parts of absolute alcohol at 37° C. for four days. It is then filtered through filterpaper and the filtrate collected and brought to a state of dryness by evaporation. The use of the electric fan is not necessary, for if poured into large flat dishes, the filtrate will evaporate in from twelve to twenty-four hours. The residue is then taken up with a sufficient quantity of ether, and the turbid ethereal solution is allowed to stand for a few hours in a cool place until cleared. The clear ethereal portion is then carefully decanted off into another clean evaporating dish, and then allowed to become concentrated by evaporating the ether off. The concentrated ethereal solution is now mixed with about 10 volumes of pure acetone. A light yellow precipitate forms, which is allowed to settle, and the supernatant fluid is decanted off. Dissolve each 0.3 gm. of this substance in 1 c.c. of ether and add 9 c.c. of pure methyl alcohol. As a rule, the greater part of the substance goes into solution. This alcoholic solution remains unaltered for a long time, and is kept as a stock solution from which the emulsion for immediate use may be prepared at any time by mixing 1 c.c. with 19 c.c. of saline solution. This solution is then titrated for antigenic, anticomplementary, and hemolytic action. According to Noguchi, if the extract is anticomplementary or hemolytic in doses of 0.4 c.c. of a 1 : 10 dilution, it is unsuitable. If it produces complete inhibition of hemolysis with 0.1 c.c. of syphilitic serum in doses of 0.02 c.c. or less of the same dilution ( = 0.2 c.c. of a 1:100 dilution), it is suitable. In making the fixation test, 0.1 c.c. of a 1 :10 emulsion is to be used, thus employing five times the minimal antigenic dose which does not cause non-specific fixation and is not unduly sensitive. 6. Lecithin and Cholesterin. — Browning, Cruickshank, and McKenzie advocate the use of a mixture of ox-liver lecithin and cholesterin as antigen in testing for the syphilitic reaction. They find that the amount of complement fixed by lecithin alone with syphilitic serums is very much increased by the addition of cholesterin; that cholesterin does not increase the anticomplementary action of the antigen; that the binding power or antigenic value of a mixture of lecithin and cholesterin is equal in most cases to crude alcoholic extracts, but is less anticomplementary. These observers use this mixture in their modified method, which consists in the accurate estimation of the amount of complement fixed by extract and syphilitic serum. It would seem that this extract should, in the ordinary methods, be controlled with less sensitive antigens, and I have found that ordinary cholesterinized alcoholic extracts of human heart are equally efficient and less difficult to prepare in performing a quantitative Wassermann reaction after the method just outlined. Preparation. — Minced ox-liver, obtained within three or four hours after death, is digested with four parts of 95 per cent, alcohol for three or four days at room temperature, during which time the mixture is stirred up at least once a" day. The filtrate is evaporated in an open flat porcelain dish on the water-bath at 60° C. for four or five hours until a syrupy mass remains. This is rubbed up with washed and dried quartz sand until a firm mass results. The mixture of dried extract and sand (about 50 grams of sand to the residue of 1000 c.c. of extract) is placed in a spheric flask, closed with a perforated rubber stopper through which runs a short piece of quill tubing drawn out to a capillary point at the end. This tube serves to prevent the vapor in the flask from forcing out the stopper. Ethyl acetate is placed in the flask, which is then stoppered and immersed up to its neck in water at 60° C. The flask is shaken repeatedly, and after ten minutes the ethyl acetate is poured off into a hot-water filter, the funnel jacket being kept at 60° C., and the solution filtered through fat-free filter-paper. Another portion of ethyl-acetate is added to the sand, and the extraction repeated. After a third treatment practically all the soluble matter will have been extracted. In all, about 170 c.c. of ethyl acetate should be used to extract the residue of 1000 c c. of crude extract. The portion that is precipitated when the ethyl acetate solution is placed in the ice-chest overnight is again dissolved in ethyl acetate at 60° C. and the solution again placed in the ice-chest overnight. Finally the portion insoluble in ethyl acetate in the cold is dissolved in water-free ether (sp. gr., 0.717) at room temperature. To the ethereal solution in a glass cylinder four volumes of acetone are added, causing a precipitate to be deposited. Precipitation is aided by shaking the mixture for several minutes. Separation is complete in ten minutes. The supernatant fluid is poured off, and the crude precipitate of lecithin is redissolved in ether and the precipitation with acetone repeated twice. The last traces of lecithin may be removed by extracting the residue with an additional small quantity of alcohol. The ordinary commercially "pure" reagents are satisfactory for this method of preparation of lecithin. The lecithin of 1000 c.c. of crude extract should be extracted with about 100 c.c. of alcohol. The strength of the solution is estimated by evaporating 10 c.c. at 57° C. and weighing. The alcoholic lecithin solution is kept in a stoppered bottle at room temperature in the dark. After allowing it to stand for a week a 0.75 per cent, solution in alcohol is diluted 1 : 7 with normal salt solution, to secure the maximum turbidity, and titrated. Browning and McKenzie use 0.6 c.c. of this emulsion as the antigenic dose. 7. Aqueous Extract of Pallidum Culture. This antigen is prepared by Noguchi, who uses pure cultures of Treponema pallidum in ascites kidney agar. Preferably several strains should be used in the preparation, which corresponds quite closely to luetin. Cultures grown seven, fourteen, twenty-one, twenty-eight, thirty-five, and forty-two days are chosen and examined, and those that show the best growths in the agar columns are selected. The oil is poured off, the tubes cut just above the kidney, and the column of ascites agar between the piece of kidney and the oil removed with particular care, so as not to include the kidney or the oil. This substance is ground in a mill until the spirochetes show disintegration. The thick emulsion is then diluted with normal salt solution and heated to 60° C. for one-half hour; 0.4 per cent, phenol is added as a preservative, and the emulsion titrated for its anticomplementary dose. In conducting complement-fixation reactions with pallidum antigen one-half of the anticomplementary dose is used, and the serum must be inactivated. COMPARATIVE ANTIGENIC VALUES OF VARIOUS EXTRACTS For several years past I have been particularly interested in studying, from a practical standpoint, antigenic values of the extracts most commonly employed in the serum diagnosis of syphilis, and comparing them with suitable alcoholic extracts of syphilitic liver as a standard antigen. For this purpose antigens were carefully chosen after titration, and only those were employed that were safely free from anticomplementary action and whose antigenic dose was known. A large number of serums and cerebrospinal fluids from syphilitic and non-syphilitic persons were tested with numerous different extracts at the same time, and under similar conditions. A suitable alcoholic extract of syphilitic liver was always included among the antigens in testing each serum or fluid, and the other extracts compared with it in determining their antigenic value. In the following table the results of such studies, covering a period of two years, are given: The results of these studies have shown : 1. That cholesterinized alcoholic extracts of human, beef, and guinea- <pig heart are far more sensitive than simple alcoholic extracts of syphilitic liver. Another peculiar feature of these antigens is the fact that in syphilis, if they react at all, they usually do so quite strongly. 2. That the addition of cholesterin to crude alcoholic extracts of syphilitic liver and of normal liver doubles their antigenic sensitiveness without materially increasing their anticomplementary and hemolytic action. 3. We have practically never found a serum that reacted negatively with a cholesterin extract and positively with an alcoholic extract of syphilitic liver. On the other hand, in about 20 per cent, of cases the cholesterinized antigens will react positively, whereas with the plain antigen of syphilitic liver the reactions are negative. In the majority of such instances the person was known to be luetic, but had received treatment and was regarded clinically as cured, or the serum was that of a long-standing and unrecognized case of lues. Unfortunately, slight reactions may be secured with about 5 per cent, of normal serums. For this reason, when conducting tests for diagnostic purposes, I control the cholesterinized extracts with less sensitive antigens, such as alcoholic extract of syphilitic liver and acetone-insoluble lipoids. 5. In our experience, repeated negative reactions with satisfactory cholesterinized antigens constitute the best evidences of the absence of lues or testify to the recovery from a luetic infection. The treatment of syphilis should be continued until the patient's serum reacts negatively with alcoholic extract of syphilitic liver, and finally with cholesterinized extracts. The disease cannot be regarded as cured until the reaction i has remained negative for a year or two at least, and treatment must not be discontinued until this result is secured, or it is shown that the serum is " Wassermann fast" and that it is impossible to secure a negative reaction. 6. For the less experienced worker, or when but one antigen is being used in conducting the reaction, a properly prepared alcoholic extract of syphilitic liver is to be recommended. One drawback to the use of this extract is the difficulty of obtaining suitable tissues for the preparation of the antigen. It has been my practice for many years to preserve the livers of as many still-born fetuses as I could obtain in 70 per cent, alcohol, and to discard them later unless on section they showed the presence of numerous spirochetes. These antigens are usually more sensitive than similar extracts of normal liver, but it is important to remember that not every extract is satisfactory simply because it is prepared of syphilitic tissues. 7. A suitable preparation of acetone-insoluble lipoids, prepared after the method of Noguchi, constitutes a sensitive, reliable, and satisfactory antigen. When properly titrated and standardized and used with inactivated serums, this antigen may prove quite sensitive and safe. Noguchi, in his efforts to simplify the technic of the syphilis reaction, impregnated filter-paper with this antigen and allowed it to dry. This preparation is unstable and generally unsatisfactory. The antigen is best preserved in a stock bottle or in ampules, and is diluted with salt solution just before being used in the test. Under these conditions we have found these extracts to be quite stable. serve as satisfactory antigens. Boas uses alcoholic extracts of human heart (Michaelis) exclusively, and has found that they yield better results than alcoholic extracts of syphilitic liver. Garbat and others use and recommend similar extracts of guinea-pig heart. 8. Aqueous extracts of pure cultures of pallida have not thus far yielded results equal or superior to ordinary non-specific antigens. As compared with lipoidal extracts, they have generally yielded reactions that are much weaker, and in primary and secondary syphilis may react entirely negatively. Much is yet to be learned, however, of bacterial antigens in general, and the subject must be regarded as still in the experimental stage. It may be said to be well proved that extract antigens in the syphilis reaction are not biologically specific, and need not be extracts of syphilitic tissues. An antigen cannot give reliable or satisfactory results unless it is carefully titrated and its properties determined. Antigens may serve as a frequent source of error when the complement-fixation reactions are conducted by those possessing insufficient knowledge of their good and bad properties. The test for the syphilitic reaction should not be undertaken by any one not competent to titrate and judge of the qualities of the antigen to be employed. must be diluted with normal salt solution before being used. If extracts and diluent are mixed quickly, the emulsion is clear or slightly opalescent. If the diluent is added slowly to the organic extract, the resulting mixture becomes quite turbid and milky. As shown by Sachs and Roudoni, the antigenic power of the extract is more marked with the turbid than when the clear or opalescent emulsion is used. , For this reason, in testing for the syphilis reaction the emulsion of organic ^ extract should be made so as to secure the maximum amount of turbidity. The required amount of antigen is placed in a test-tube, and the salt solutionis added slowly with a pipet; or the salt solution may be placed in a tube and the extract floated on it and gradually mixed. Although with each new extract it may be necessary to titrate with various dilutions before one that is satisfactory is reached, experience has shown in the majority of instances that the following dilutions are usually correct: J Although these emulsions mil keep for a few days if placed in the refrigerator, it is advisable to make up only the amount required for immediate use} as freshly prepared emulsions are better than older ones. itself is capable of fixing or inactivating the complement. 2. The hemolytic dose, or that amount of antigen that in itself is capable of lysing red blood-cells. This action is probably due to the presence of certain lipoids and alcohol. amount of syphilitic serum. 1. Anticomplementary Titration. The determination of the anticomplementary dose is probably the most important, for if an extract were used in an amount that was anticomplementary or capable of fixing complement in a non-specific manner, all the tests would show false positive reactions, regardless of whether the serum was from a normal or from a luetic person. All tests are conducted with chemically clean and preferably sterile test-tubes (12 cm. by 13 mm.) and graduated pipets. Accuracy in measurements is very essential in performing all complement-fixation work. A preliminary titration of the hemolysin is made, with the complement and corpuscle suspension to be used in titrating the antigen, in order to determine its hemolytic dose, i. e., to adjust the hemolytic system. If, for instance, the hemolytic serum is known to have a titer of about 1 : 2000 (see p. 397), a stock solution is made by diluting 1 c.c. of the serum with sterile salt solution to make a dilution of 1:200. In a series of six test-tubes increasing amounts of this diluted amboceptor are placed: 0.05 c.c., 0.1 c.c., 0.15 c.c., 0.2 c.c., 0.3 c.c., and 0.4 c.c.; to each tube add 1 c.c. of complement Serum diluted 1 : 20 ( = 0.05 c.c. undiluted serum) and 1 c.c. of a 2.5 per cent, suspension of sheep's cells and sufficient salt solution to bring the total contents up to 3 or 4 c.c. Each tube is shaken gently and incubated at 37° C. for an hour. At the end of this time that amount of amboceptor that just completely hemolyses the corpuscles is taken ns the hemolytic unit (Fig. 106). In conducting the antigen titrations twice this amount is used as the dose. Increasing amounts of this emulsion are placed in a series of testtubes: 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.5, and 2 c.c. To each tube are now added 1 c.c. of the diluted complement serum ( = 0.05 c.c. undiluted serum) and sufficient normal salt solution to bring the total volume up to 3 c.c. Shake each tube gently and incubate for one hour at 37° C. Then add to each tube 1 c.c. of the corpuscle suspension and a dose of amboceptor equal to 2 units, as just determined by previous titration. Shake gently and reincubate for another hour and a half, when a preliminary reading of the results may be made. That amount of antigen that shows beginning inhibition of hemolysis is regarded as the anticomplementary unit. The final readings are made after the tubes have stood overnight in a refrigerator at low temperature (Fig. 111). This titration may also be made in the presence of normal serum, although this is not absolutely necessary. The serum must be perfectly fresh, and must be that from a person known to be free from lues. It is inactivated by heating to 55° C. for half an hour, and 0.2 c.c. is added to each tube. Complement and salt solution are now added, and the titration conducted in the manner just described. Normal serum may absorb a small amount of complement in itself, and hence a titration conducted with serum may show a slightly lower anticomplementary dose. The following controls are included: 1. A hemolytic system control, containing the complement, corpuscles, and amboceptor in the same amounts as were used in conducting the titration. This control should show complete hemolysis. \l 2. Hemolytic Titration. As previously mentioned, organic extracts are capable in themselves of hemolyzing red cells; this is due to the hemotoxic action of lipoids and alcohol. Extracts of organs that have undergone advanced autolysis and decomposition are very likely to be hemolytic. Serum exerts an inhibiting influence on the lytic action of an organic extract. Hence the hemolytic dose of an extract depends largely on whether or not complement serum is used in the titration. When an organic extract is titrated in the presence of complement, the hemolytic dose is higher than the anticomplementary dose. In the foregoing titration 3 c.c. of the extract emulsion showed beginning hemolysis, and when 4 c.c. was used, hemolysis was complete. These large amounts of emulsion give the tube contents quite a milky appearance, but close inspection shows that all the cells are broken up. As a general rule, the hemolytic titration is not absolutely necessary. It may be conducted with the anticomplementary titration by adding another tube or two to the foregoing series, with higher doses of extract; or this titration may be conducted separately, and without complement and hemolysin, by using the same doses of antigen with 1 c.c. of corpuscle suspension and sufficient salt solution to bring the total volume in each tube up to 3 or 4 c.c. 3. Antigenic Titration. — As previous^ stated, this titration is not absolutely necessary, as one-fourth the anticomplementary dose of an extract may be used in the main test. For instance, in the foregoing titration 0.3 or 0.4 c.c. may safely be used in making the test for the syphilitic reaction. Different extracts vary, however, in their antigenie value. Some may be highly anticomplementary and have a comparatively low antigenic value; purer extracts, such as acetoneinsoluble lipoids or cholesterinized alcoholic extracts of heart, are largely free from anticomplementary action, and at the same time possess a high antigenic value. It is advisable, therefore, to use an ^ antigen whose full antigenic as well as anticomplementary doses are known, for, while it is necessary to use sufficient antigen, it is not advisable to use a larger amount than is necessary. For this titration all antigens except alcoholic extracts of syphilitic liver, should be diluted 1 : 20 with normal salt solution. Usually the antigenic unit is so much lower than the anticomplementary unit that it is best determined with a more dilute antigen. The titration is conducted in a manner similar to the anticomplementary titration, except that 0.2 c.c. of fresh and inactivated serum from a known and untreated syphilitic person is added to each tube. Increasing doses of antigen, patient's serum, and complement are mixed, shaken, and incubated for one hour. Two units of hemolysin and corpuscles are then added, the tubes shaken and incubated for another hour, after which the preliminary reading is made. The final reading is taken after the tubes have been placed over night in a refrigerator at low temperature. That amount of antigen that shows just complete inhibition of hemolysis is taken as the antigenic unit (Fig. 112). In conducting the syphilis reaction two to four times this unit is used, providing that these amounts are at least four or five times less than the anticomplementary dose. This larger antigenic dose is advisable, because the exact unit may not be sufficient with serums containing but small amounts of syphilis antibody such as those of treated or long-standing cases of lues. In this instance 0.15 c.c. of the emulsion represents the antigenic unit. In performing the Wassermann reaction 0.3 or 0.4 c.c. was used, and these amounts were about one-fourth the anticomplementary dose. It is not unusual to find cholesterinized alcoholic extract and acetone-insoluble lipoids perfectly antigenic in 0.05 c.c. of a 1:20 dilution, and not anticomplementary under 1 or 2 c.c. of a 1:10 dilution. In these instances four times the antigenic dose, or 0.2 c.c. can be used, and yet this amount is at least 10 times smaller than the anticomplementary dose — a condition of affairs that constitutes a safe and desirable, antigen. accepted as satisfactory. Antigen containers should be well stoppered and kept in the refrigerator. Deterioration may set in suddenly, and they should, therefore, be retit rated every few weeks. VARIOUS METHODS FOR CONDUCTING THE SYPHILIS REACTION First Method; the Original Wassermann Reaction. — The simplest technic, and the one best adapted for inexperienced workers, is the original Wassermann reaction, performed with alcoholic instead of aqueous extracts of syphilitic liver as antigen. It is true that this method is not an exact quantitative reaction, and that it is probably less delicate than some of the modified methods, but its advantages are that it is easy of manipulation, is readily learned, and is especially recommended for persons who perform these tests at irregular intervals, as false positive reactions are less likely to occur than when the more delicate methods are used. Second Method ; the Wassermann Reaction with Multiple Antigens. — In this method the technic is essentially the same as in the first method, except that three different antigens are used instead of one, namely, cholesterinized extract of normal heart, alcoholic extract of syphilitic liver, and acetone-insoluble lipoids. This method has three advantages: (1) It permits the use of a cholesterinized extract under conditions where any tendency to non-specific fixation is to be controlled ; (2) an antigen may at any time suddenly become anticomplementary and yield false results, whereas by this method the source of error is detected and may be avoided, since it is not dependent upon any one extract; (3) an extensive study of the comparative values of antigens has led to the distinct impression that the lipodophilic antibody in different syphilitic serums frequently shows a special affinity for the lipoids in a certain plain antigen more than it does for those in another antigen; in fact, I have not infrequently found that, with weakly positive serums, if one antigen had been emploj^ed, a false negative report would have been rendered, the true reaction being given by the other two antigens. These results could not be ascribed to faulty antigen, for with other weakly positive serums the extract would be found to react satisfactorily. As previously mentioned, cholesterinized alcoholic extracts are very sensitive, so that from this standpoint additional antigens would appear to be superfluous. This very property, however, in my opinion, renders it advisable to control them with less sensitive extracts. In this way all the advantages of a very sensitive antigen may be secured, and the disadvantages avoided until more extended use demonstrates whether or not it is entirely safe to use these extracts alone. With strongly reacting serums all antigens possess equal antigenic power. With the serums of long-standing or treated cases of syphilis the cholesterinized extracts may react strongly positive, whereas with the aqueous and the alcoholic extracts the reactions are weakly positive, or negative with one and positive with the other. In cases of syphilis that have received considerable treatment the reaction may be negative at first with the aqueous and the alcoholic extracts, and as treatment is continued it may finally be negative with the cholesterinized extracts. In a certain percentage of cases, especially those of old infections of the central nervous system, the reaction is positive with the cholesterinized extract and negative with the other extracts; strong reactions of this character usually indicate syphilitic infection. Occasionally a weak (10 per cent, or less, inhibition of hemolysis) reaction may be had with the serum of a person who denies syphilis. Third Method; the Wassermann Reaction with Varying Amounts of Patient's Serum. — One disadvantage of the regular Wassermann technic is that it may not readily show improvement of the patient while the treatment is going on. For instance, if complete fixation of complement occurs with 0.2 c.c. of serum, one does not know whether this is the smallest fixing dose, or whether there might be a fixation even with much smaller quantities of serum. This is very important in examining cases during the course of the treatment, as otherwise improvement in the condition may be overlooked. Just as soon, however, as the reaction with 0.2 c.c. of serum is a degree less than absolutely positive, then the various steps, down to complete negative reactions, are readily observed and recorded by the usual Wassermann technic. This disadvantage may be overcome by using at least seven different doses of serum: 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2 c.c. In this way a means is afforded for judging of the strength of the reaction, and the effect of antisj^philitic treatment is readily observed. Fourth Method; the Wassermann Reaction with Varying Amounts of Complement. — It has previously been pointed out that the syphilis reaction is dependent upon the fact that while hemolytic complement may be rendered inactive or fixed by serum alone and organic extract alone, it is characteristic of syphilis that a mixutre of serum and extract will absorb or fix more complement than the sum of the amounts absorbed by these two substances alone. In the foregoing methods no attempt has been made to measure the amount of complement absorbed by serum and antigen alone, but sufficient complement has been furnished to allow for this non-specific fixation, and we are content to show that the serum and antigen alone do not absorb enough complement to interfere with hemolysis, so that any inhibition of hemolysis may be interpreted as specific complement fixation. first, by the serum and antigen alone, and second by these two substances combined. The complement absorbed is measured in terms of hemolytic doses. This method consumes a little more time and more of the various reagents is required. It is, nevertheless, the best quantitative method we have, and shows exactly the degree of complement fixation in each case. In conducting any complement-fixation test the following are essential factors if success is to be achieved: (1) Reliable reagents, particularly a good antigen must be had, for no matter how much care is exercised, good results cannot be secured with indifferent reagents; (2) the observer must possess a thorough working understanding of the underlying principles and particularly of the quantitative relations of the various reagents; (3) there must be an accurate adjustment of the hemolytic system; (4) he must have a careful, painstaking and accurate habit of pipeting small amounts. Accuracy should never be sacrificed for speed, as the latter is properly acquired only with experience. THE ORIGINAL WASSERMANN REACTION This is the original Wassermanri reaction, except that an alcoholic, instead of an aqueous extract of syphilitic liver, is used as antigen. This is the simplest of all technics, and, when properly performed, constitutes, in the final analysis, a reliable test and one especially adapted for those not constantly engaged in this work. 1. Complement. — Fresh clear serum (not over twenty-four hours old) of a healthy guinea-pig. Dilute 1 : 10 by adding 9 c.c. of sterile normal saline solution to each 1 c.c. of serum. Dose, 1 c.c. (= 0.1 c.c. of undiluted. serum). 2. Corpuscles. — Sheep's blood washed three times and diluted to make a 5 per cent, suspension. For example, 1 c.c. of corpuscles in 19 c.c. of salt solution makes up sufficient for a number of tests. 3. Hemolytic Amboceptor. — Serum of a rabbit immunized with washed sheep's corpuscles. As stated elsewhere, this serum is heated to 55° C. for half an hour, and an equal part of chemically pure glycerin is added. Mix well and preserve in sterile 1 c.c. ampules. Each ampule will, therefore, contain 0.5 c.c. of serum. One stock dilution is prepared in such manner that about 0.2 c.c. represents one hemolytic dose. One may otherwise prepare a whole series of flasks with various dilutions, and in making a titration to use 1 c.c. of each di- lution; I have found it much more accurate, simple, and economical, however, to prepare one stock dilution, which is titrated with each complement and corpuscle suspension before each day's work. For example, if a serum is known to have a titer of 1 : 2000, an ampule (0.5 c.c. of serum) is diluted with 200 c.c. of salt solution; this gives a dilution of serum approximately 1:400, of which 0.2 represents one hemolytic dose. The titration must be repeated each time to make sure of this, because the complement of different pigs may vary in activity, and the chief object is to adjust the amboceptor and complement to each other. Titration of Amboceptor. — Into a series of six test-tubes place increasing amounts of the amboceptor dilution: 0.05 c.c., 0.1 c.c., 0.15 c.c., 0.2 c.c., 0.25 c.c., and 0.3 c.c. Add 1 c.c. of complement (1 : 10) and 1 c.c. of corpuscle suspension to each tube, and sufficient salt solution to make the total volume in each tube about 4 c.c. Shake gently and incubate for one hour at 37° C. At the end of this time the tube showing just complete hemolysis contains one hemolytic dose, or unit of amboceptor. In the tests double this amount, or two units, is used. The amboceptor titration is very important. Under no circumstances should the same dose be used day after day without titration, because the complement of different guinea-pigs may vary in its activity, and these variations would be detected and would be adjusted in this titration. For example, with a weaker complement the dose of amboceptor required to effect complete hemolysis becomes higher; each new corpuscle suspension may also vary slightly in the actual number of cells contained in 1 c.c., but this makes no difference when each suspension is titrated with the complement and amboceptor to be used in the day's work. This titration is set up first, and while it is in the incubator, the main tests are arranged. 4. Antigen. — Alcoholic extract of syphilitic liver or acetoneinsoluble lipoids of proved value may be used. It is well to estimate just how much antigen will be required for the tests on hand, so that no waste will occur, as fresh emulsions are better than old ones carried over from day to day. The dose should be at least double the titrated antigenic unit, or one-fourth of the anticomplementary dose. For instance, if an alcoholic extract of syphilitic liver diluted 1 : 10 is found on titration to be perfectly antigenic in doses of 0.2 c.c., and not anticomplementary in amounts under 2 c.c., then 0.4 c.c. maybe used in making the tests, as this amount is still about five times less than the anticomplementary dose, and well within the range of safety against non-specific complement fixation. If 10 tests are to be made, then at least 4.4 c.c. of diluted antigen are required, including sufficient for the antigen control, or in round numbers, 0.5 c.c. of antigen plus 4.5 c.c. of salt solution in order to secure the maximum turbidity slowly added. 5. Serum. — Serum should be fresh and clear and heated in a waterbath to 55° C. for half an hour before using. The temperature should not go above 56° C. nor below 55° C. The complement in perfectly fresh serum is usually inactivated at this temperature within fifteen minutes, but it is better to adopt the period of one-half hour as a routine, especially in removing heat-sensitive anticomplementary sub- > stances that develop in serums more than a day old. Dose, 0.2 c.c. 6. Cerebrospinal Fluid. — This should be fresh and free from blood. It is used unheated, as spinal fluid contains little or no hemolytic <complement. The dose should be at least four times that of the serum, or 0.8 c.c. The Test. — A front and a rear tube for each serum are placed in a rack. Each tube is marked plainly with the patient's name or initials, and in addition the front tube is marked with the number of the antigen or with the letter "A, " or the word " antigen" is written on it, the rear tube being marked " control" (serum control). The necessity for carefully marking each tube is nowhere more important than in conducting Wassermann reactions with a number of serums, as the slightest error or lapse of memory may result in confusion and prove to be quite a serious matter. In each series of reactions -the serum from a known case of syphilis that has given a positive reaction and the serum of a known nonsyphilitic person are included as positive and negative controls respectively. Into each front tube the proper dose of antigen is placed; to the front and rear tubes 0.2 c.c. of the patient's serum is added. To all tubes 1 c.c. of the complement (1 : 10) and sufficient normal salt solution are then added to bring the total volume in each to about 3 c.c. The rear tube of each set is the serum control; the positive and negative serums are treated in just the same manner as the patient's serum. In addition to these there are three other important controls that should not be omitted: salt solution. Each tube is gently shaken and incubated at 37° C. for an hour, when two hemolytic doses of amboceptor and 1 c.c. of corpuscle suspension (5 per cent.) are added to each tube except the corpuscle control. Tubes are shaken and reincubated for an hour or an hour and a half, depending upon the hemolysis of the serum controls, after which a preliminary reading is made and recorded. With partially positive reactions the tubes may be centrifuged in order to read the relative amounts of hemolysis, and the final reading made at once, or the tubes may be placed in the refrigerator (just above freezingpoint) and the final readings made the next morning. Tubes are shaken gently and incubated at 37° C. for an hour, after which two hemolytic doses of amboceptor and 1 c.c. of corpuscle suspension are added to each. They are then gently shaken and reincubated for an hour or an hour and a half, after which a preliminary reading is made. All the tubes in the rear row (upper row in table) (serum controls), the antigen and hemolytic system controls, and the front tube with the negative normal serum, are completely hemolyzed. The front tubes with the unknown serum and Cerebrospinal fluid and the positive serum control show inhibition of hemolysis or positive reactions. This scheme illustrates the technic employed with an unknown serum and Cerebrospinal fluid. The proper dose of diluted antigen is taken as 0.4 c.c., and two doses of hemolytic amboceptor determined by titration as equivalent to 0.4 c.c. of the stock dilution. READING AND RECORDING THE WASSERMANN REACTION 1. The hemolytic system control is inspected first. It should show complete hemolysis, indicating that the complement and amboceptor were active and have been used in sufficient amounts. If a few corpuscles are found in the bottom of the tube, some error in pipeting has probably occurred, too many corpuscles or too little complement or amboceptor having been introduced. the solution is isotonic and that the corpuscles are not unduly fragile. 3. The antigen control should show complete hemolysis, indicating that the dose used was not anticomplementary. If this tube shows incomplete hemolysis, due to the anticomplementary action of the antigen, all the front two tubes will also show some inhibition of hemolysis, due to this non-specific complement fixation, and it is necessary to repeat the tests with another extract. 4. The rear tubes of all serums should be completely hemolyzed, indicating that the serums were practically free from anticomplementary action as previously stated, most antigens and serums are usually very slightly anticomplementary if small amounts of complement are used with a close single unit of amboceptor, but in this technic the complement and two units of amboceptor are sufficient, under ordinary circumstances, to offset this influence. If, however, a serum is more than normally anticomplementary, the rear tube will show some inhibition of hemolysis, and, of course, in the front tube a similar inhibition, and probably to a greater degree, will be seen. If the serum is very slightly anticomplementary and the front tube shows complete inhibition of hemolysis, the reaction is in all probability positive. If the rear tube, however, shows marked inhibition of hemolysis, indicating that it is highly anticomplementary, the result cannot be determined, but a retest with fresh serum must / be made. This indicates the great importance of the "serum control," and it may be stated that a test should never be made without it. antigenic properties. As the complement is "fixed" by the syphilis antibody and extract, hemolysis could not occur when the corpuscles and amboceptor were added. If a portion of the complement is fixed by antibody and extract, then the unfixed portion will hemolyze some of the corpuscles, the reaction being moderately positive, slightly positive, etc., depend- ing upon the degree of hemolysis that takes place. This illustrates the importance of observing exactness in pipeting, and the great influence of quantitative factors in testing for the Wassermann reaction, for if an excess of complement is used, there may be sufficient for all the syphilis antibody, and enough unbound complement to hemolyze all the corpuscles. In this manner a false negative reaction will result. Corpuscles and sufficient hemolytic amboceptor are added merely in order to test for any free complement. Under proper conditions a total lack of hemolysis indicates that there is no free complement, but that it has been fixed by syphilis antibody and extract, constituting a positive reaction (+ -f- + +). Complete hemolysis indicates that complement was not bound and that syphilis antibody was, therefore, absent from the fluid tested — a negative reaction ( — ). Partial hemolysis indicates that a portion of the complement has been fixed by smaller amounts of syphilis antibody and of the extract, yielding partially positive reactions (+ + +; 6. The front tube containing the known normal serum should show complete hemolysis because, in the absence of syphilis antibody, the complement remains free to hemolyze the corpuscles with the hemolytic amboceptor. = complete inhibition of hemolysis = strongly positive. + + + = 75 per cent, inhibition of hemolysis = -moderately positive. + + = 50 per cent, inhibition of hemolysis = weakly positive. -h = 25 per cent, inhibition of hemolysis = very weakly positive. == = less than 25 per cent, inhibition of hemolysis = delayed Under the third method a scale is given that is easily prepared for making these readings. However, after some experience they are readily made, and at first should be attempted only after the nonhemolyzed corpuscles have been centrifuged or allowed to settle to the bottom of the tube. As stated elsewhere, this method is not an accurate measure of the amount of syphilis antibody, but constitutes a relative and convenient gage of value within certain limits. In reporting reactions to the clinician, the plus signs should not be used, or if used, should be interpreted by the terms "strongly positive," "weakly positive, " etc. Practically the same technic is used in this as in the first method, except that three different antigens, instead of one, are used with each serum, for the reasons previously stated; for economy the amounts of each reagent are just one-half those originally employed. This method is to be strongly recommended, as it is simple, accurate, and reliable. Although a little more work is demanded and a larger quantity of the various reagents is required, the results warrant the expenditure of a little more labor, and the second objection is readily overcome by using half the quantities prescribed in the original Wassermann technic, as given in the first method. 1. I generally use the following three antigens: (1) A cholesterinized alcoholic extract of human heart; (2) alcoholic extract of syphilitic liver; (3) acetone-insoluble lipoids. As previously stated, these extracts are used in amounts equal to from two to four times their titrated antigenic unit, providing these doses are at least four times smaller than the anticomplementary units. The amount of each antigen required for the work at hand is calculated, placed in test-tubes, and slowly diluted with the requisite amount of salt solution to secure maximum turbidity of the emulsions. 2. The complement is diluted 1 : 20 and is used in doses of 1 c.c.; sheep's corpuscles are made up into a 2.5 per cent, suspension, and used in 'doses of 1 c.c.; antisheep amboceptor is titrated as in the first method, and used in doses equal to 2 units; serums are heated to 55° C. for half an hour, and used in doses of 0.1 to 0.2 c.c.; cerebrospinal fluid is used unheated in amounts of 0.8 c.c. With fresh sera I / use routinely 0.2 c.c. as the dose; the 0.1 c.c. dose is used in case the v amount of serum at hand is insufficient for the 0.2 c.c. dose, or in case the serum is suspected as containing thermostabile anticomplementary substances. The complement may be titrated instead of the hemolysin (technic on page 398) and used in a dose equal to 2 units. A large series of comparative tests with both methods and the same sera have yielded almost identical results. now added. Controls. — A known positive and negative serum should be included, unless one is performing a large number of tests with reliable antigens every week, in which case, among many serums, a few at least are likely to be positive. Under these circumstances these controls may be omitted; as a general rule, however, they should be included. To the hemolytic system control tube 1 c.c. of complement dilution and 2 c.c. of salt solution are now added. Three antigen control tubes are set up for each antigen with the dose employed, plus 1 c.c. of complement dilution and sufficient salt solution to make the total volume about 3 c.c. The corpuscle control receives 1 c.c. of the suspension plus 3 c.c. of salt solution. All the tubes are shaken gently and placed in the incubator for an hour at 37° C. Instead of the incubator a water-bath at 38° C. may be employed for one hour (not less) for the primary and secondary periods of incubation, or the primary period may be conducted in a refrigerator at 8° C. for four hours or over night. As shown by McNeal, the latter method yields particularly delicate reactions. In the latter method the secondary period of incubation is conducted in a water bath at 38° C. for about an hour. At the end of primary incubation the amboceptor and corpuscles are added to each tube except that containing the corpuscle control. Each tube is shaken gently and reincubated for an hour or longer, depending upon the hemolysis of the controls, when the readings are made. By making the readings at this time the influence of an excess of hemolysin due to the presence of natural antisheep hemolysin in the human sera is. avoided and lesser degrees of complement fixation detected, which may become completely hemolyzed if the tubes are set aside over night. Reading the Results. — The readings are made in the same manner as described in the first method, the controls always being inspected first. The hemolytic, antigen, and serum controls and known negative serum tubes should all be hemolyzed. The antigen tubes containing the positive syphilitic serum should not be hemolyzed. Re- With strongly positive serums there is complete inhibition of hemolysis with all three antigens. With serums of long-standing or treated cases of syphilis containing smaller amounts of antibody the reaction with the cholesterinized extract is usually strongly positive, whereas with the other two antigens the degree of inhibition of hemolysis is less marked and variable (see Fig. 115). In from 15 to 20 per cent, of cases the cholesterinized extract shows a 50 per cent, or more inhibition of hemolysis, whereas with the other two antigens the reactions are negative. In our experience the majority of such serums were taken from patients giving a frank history of syphilis of many years' standing and from known cases undergoing treatment, further therapy being indicated until the reaction finally becomes negative when cholesternized extracts are used. In a small proportion of cases a feebly positive reaction of 25 per cent, or less inhibition of hemolysis may be found with the cholesterinized extract alone. Many of these reactions occur with serums of treated cases of syphilis; on the other hand, a similar reaction may occur with about 5 per cent, of normal serums, so that if the history and clinical conditions are clearly negative, a slight degree of inhibition of hemolysis (5 to 10 per cent.) with the cholesterinized extract and marked hemolysis with the other two antigens may be interpreted as a negative reaction. After a new antigen has been prepared and titrated, it should be tested out in this manner by placing it in the series along with at least two other older antigens of proved value, and used in the examination of a large number of serums before it is finally accepted as reliable. As previously stated, it may be desirable to measure the quantity of syphilis antibody in a patient's serum more accurately, especially when observing the effect of treatment. This is readily accomplished by using decreasing doses of serum with constant doses of antigen and complement. In those tubes showing partial inhibition of hemolysis the degree of hemolysis is determined by comparison with a hemoglobin scale (Boas). 1. One antigen is employed, either an alcoholic extract of syphilitic liver or acetone-insoluble lipoids. The same general rule as to dosage is employed, namehr, from two to four times the titrated antigenic unit, providing these amounts are not more than one-fourth the anticomplementary dose. diluted 1 : 10 by adding 5.4 c.c. of salt solution. 3. Fresh guinea-pig serum complement is diluted 1 : 20 as usual, and used in doses of 1 c.c. ; sheep corpuscles are made up in a 2.5 per cent, suspension and used in doses of 1 c.c.; antisheep amboceptor is adjusted to the complement and corpuscles by a method of titration, as given with the first method, and used in a dose equal to 2 hemolytic units. The Test. — Eight test-tubes are arranged in a row and the first marked with the patient's name; in each of the first seven tubes the dose of antigen is placed. The following amounts of diluted serum (1 : 10) are then added: the maximum dose employed. In testing cerebrospinal fluid the following doses may be used (undiluted): 0.1 c.c., 0.2 c.c., 0.4 c.c., 0.6 c.c., 0.8 c.c., 1 c.c., 1.5 c.c., and 1.5 c.c. for the eighth or control tube. and sufficient salt solution to bring the total volume in each up to 3 c.c. Controls. — Unless one is examining a large number of serums and is sure that the antigen is satisfactory, known positive and negative serum controls may be included in the series. As a general rule, however, they should not be omitted. The hemolytic system control receives at this time 1 c.c. of the complement dilution and 2 c.c. of salt solution. The antigen control receives the dose employed plus 1 c.c. of complement and sufficient salt solution to bring the total volume up to 3 c.c. The corpuscle FIG. 115. — WASSERMANN REACTION (SECOND METHOD). Shows a + + -f + reaction with the cholesterinized extract (C. H) ; a + reaction with the alcoholic extract of syphilitic liver (S), and a -f- + reaction with the extract of acetone-insoluble lipoids (A) . the tube is plugged with cotton to show that it is finished. All tubes are shaken gently and incubated for one hour at 37° C., at the end of which time 2 units of amboceptor and 1 c.c. of the corpuscle suspension are added to all except the corpuscle control. Each tube is shaken and all are reincubated for an hour or an hour and a half, the length of time depending upon the hemolysis of the serum controls when the readings are made. Reading the Results. — As is usual, the controls are examined first. The hemolytic, antigen, negative serum, and all serum controls should be completely hemolyzed. The corpuscle control should show no hemolysis, indicating that the salt solution was isotonic and the corpuscles free from undue fragility. A 1 per cent, hemoglobin solution in distilled water is prepared by mixing 1 c.c. of the washed corpuscles used in preparing the suspension with 99 c.c. of distilled water. A negative reaction is indicated in the seventh tube, which contains the maximum dose of serum (0.2 c.c.), by complete hemolysis or by hemolysis ranging from 80 to 100, according to the scale. Inhibition of hemolysis in this tube giving a hemoglobin scale ranging from 70 to 4 (inclusive) is regarded as a positive reaction. Absolute lack of hemolysis in this tube is 0 according to the scale, but usually the patient's serum or complement serum is sufficiently tinged with hemoglobin to give a slight color to the supernatant fluid, so that an Absolute positive reaction may range from 0 to 4. For instance, the serum of an untreated case of secondary syphilis gave the following reading (see Fig. 117). . Although these figures suffice for recording purposes, they are not adapted, without some qualifying phrase, for rendering reports to clinicians. According to the inhibition of hemolysis or the degree of hemolysis in the sixth tube containing the maximum quantity of serum the following scheme may be used in reporting the results : 10 to 30 = moderately positive = 30 to 50 = slightly positive = ( + +) 50 to 80 = very weakly positive = (+) 80 to 90 = doubtful or delayed hemolysis =(==) 100 = negative = ( — ) WASSERMANN REACTION WITH VARYING AMOUNTS OF COMPLEMENT In this method the amount of syphilis antibody in a serum is measured according to the number of hemolytic doses of complement absorbed or fixed with a constant amount of antigen. As previously stated, any organic extract used as antigen may of itself fix a certain amount of complement; a non-syphilitic serum may do the same, and a mixture of the two may fix still more, though the amounts may be relatively small. A peculiarity possessed by a syphilitic serum is that it fixes a large amount of complement when mixed with antigen; as a result the test becomes a quantitative and not a qualitative reaction. The only practical means we possess of estimating the amount of complement in a fresh serum is to ascertain the hemolytic dose, i. e., to find the smallest quantity of serum that is just sufficient completely to lyse the test amount of corpuscles with the hemolysin. When this has been done, the quantity of complement used in. the reaction may be expressed in terms of hemolytic doses fixed, and not in terms of the amount of fresh serum. When properly performed according to this method, which has been modified after the technic of Browning and Mackenzie1 and 1 Ztschr f. Immunitatsf., orig., 1909, 2, 459. Thomsen,1 the syphilis reaction becomes quite delicate and accurate, but is more complicated than the other methods, and should not be attempted until one is accustomed to the simpler test and thoroughly understands the underlying principles of the syphilis reaction and knows the many sources of fallacy. The greater amount of work that it entails and the larger quantities of complement-serum and amboceptor that are required may serve as factors against its adoption as a routine method. On the other hand, the sources of error are well under control, and the test has yielded remarkably uniform results in the hands of my colleagues in their respective laboratories, working with the serums of the same persons. The technic as given here has been worked out and tested with a large number of sera by Matsunami, Brown, Meine and I in an effort to evolve a standardized Wassermann reaction. Every phase of the Wassermann reaction has been studied specifically by experiment and the following technic is based upon these results: 2. Hemolysin. — Antisheep hemolysin is titrated by placing increasing amounts of diluted serum, as 0.1 c.c., 0.15 c.c., 0.25 c.c., 0.30 c.c., and 0.35 c.c. of a 1 : 300 dilution in a series of test-tubes and adding to each tube 0.025 complement serum (= 0.5 c.c. of a 1 : 20 dilution), 0.5 c.c. of 2J per cent, corpuscle suspension, and sufficient salt solution to make the total volume in each tube about 3 c.c. Each tube is gently shaken and incubated in the water-bath at 38° C. for one hour, when the reading is made. The unit of hemolysin is the smallest amount giving complete hemolysis. Instead of using increasing amounts of one dilution of hemolysin as above, a series of dilutions may be made in flasks, as 1 : 2000; 1 : 2500; 1 : 3000; 1 : 3500; 1 : 4000, etc., and 1 c.c. of each used in the titration. providing the hemolysin is kept at a low temperature. 3. Complement. — It is advisable to use the mixed sera of at least two or more healthy guinea-pigs. When only a small amount of complement serum is required, sufficient blood may be obtained by aspirating 2 c.c. of blood from the hearts of several large animals (see page 41). The complement serum should be clear, collected a few hours before use, and preferably from fasting animals. The mixed serum is diluted with 9 parts of normal salt solution (1 : 10) and titrated. This titra- tion must be performed with every complement serum before the main tests are conducted. In order to allow for the anticomplementary action of the antigen the complement is titrated as suggested by Thornsen, in the presence of the dose of antigen, as determined by titration, to be used in the main tests, as follows: In each of a series of six testtubes place the dose of antigen (as, for example, 0.1 c.c. of 1 : 20 dilution of acetone insoluble lipoids) ; add the following amounts of complement 1 : 10 with an accurate pipet: 0.1 c.c., 0.2 c.c., 0.3 c.c., 0.4 c.c., 0.5 c.c., and 0.6 c.c. Add sufficient salt solution to make the total volume in each tube about 2 c.c., mix gently and incubate in a water-bath at 38° C. for one hour, then one unit of hemolysin and 0.5 c.c. of 2\| per cent, suspension of cells are added, the tubes shaken and reincubated in the water-bath for an hour, when the reading is made. The unit of complement is the smallest amount producing complete hemolysis. The results of a titration are shown in Table 15a and Fig. 110. 4. Antigen. — A large number of comparative tests with the same sera and a variety of antigens have shown that a good extract of acetoneinsoluble lipoids is best adapted for this reaction. As a general rule these extracts possess a marked degree of antigenic sensitiveness and are usually free of anticomplementary action except in very large doses. Each extract must be titrated to determine the proper dose to employ; as a general rule it is sufficient to titrate an extract once every two months providing it is carefully refrigerated and is yielding satisfactory results in complement-fixation tests. 0.5 c.c. of a 2J per cent, suspension of cells: 0.1 c.c., 0.15 c.c., 0.2 c.c., 0.25 c.c., 0.3 c.c., and 0.4 c.c. In the antigenic titration the following amounts of antigen diluted 1 : 20 are placed in a series of ten test-tubes: 0.001 c.c., 0.005 c.c., 0.008 c.c., 0.01 c.c., 0.05 c.c., 0.08 c.c., 0.1 c.c., 0.2 c.c., 0.3 c.c., and 0.4 c.c.; 0.1 c.c. of fresh inactivated syphilitic serum preferably from several persons mixed, plus 2 units of complement and sufficient salt solution to make 3 c.c., are added to each tube and incubated in a water-bath at 38° C. for one hour, when 1 unit of hemolysin and 0.5 c.c. of corpuscles are added, tubes shaken, and re-incubated for an hour. The reading may be made at once or after the corpuscles have settled; the unit is the smallest amount of antigen yielding complete inhibition of hemolysis. In the anticomplementary titration the extract is diluted 1 : 20 and the following amounts placed in a series of ten test-tubes with 0.1 c.c. of fresh inactivated normal serum and 2 units of complement: 0.1, 0.2, 0.3, 0.5, 0.8, 1.0, 1.2, 1.5, and 2.0 c.c. The titration is conducted in the same manner, and the anticomplementary unit is the smallest amount of extract producing inhibition of hemolysis. serum should be included and show complete hemolysis. A satisfactory extract is one in which the antigenic unit is at least ten times less than the anticomplementary unit, and in conducting the Wassermann reaction 2 units of antigen are employed as the dose. 5. Fluid to be Tested.— Serum is heated at 56° C. for half an hour and used in dose of 0.1 c.c. Cerebrospinal fluid should be fresh and is used unheated in dose of 1 c.c. 6. The Test. — For each serum eight test-tubes are arranged in a row. One is labeled with the patient's name and all are numbered. Into each is placed 0.1 c.c. of the patient's serum. Into each of the first six tubes are placed the dose of antigen and 2, 3, 4, 5, 6, and 8 units of complement respectively. The last two tubes are the serum controls, to determine the amount of complement fixed by serum alone, and receive 1 and 2 units of complement respectively. Sufficient salt solution is added to each tube to bring the total volume up to 3 c.c., and all are incubated in the water-bath at 38° C. for an hour. One unit of hemolysin and 0.5 c.c. of corpuscle suspension are now added to each tube and reincubated in the water-bath for an hour, when the readings are made. Sharper readings may be made after the corpuscles have settled either by centrifuging or standing the tubes in the refrigerator overnight. antihuman hemolysin is at hand. Comparative tests using the antisheep and antihuman hemolytic systems with the same sera have shown that the degree of inhibition of hemolysis with positive sera is occasionally greater with the antihuman system. Controls. — The anticomplementary action of each serum is controlled in the last two tubes of each series; unless a serum is markedly anticomplementary, the use of 1 and 2 units of complement is sufficient. 2. A known positive and negative serum may be included. 3. A hemolytic control is set up with 1 unit of complement and antigen; after the primary incubation 1 unit of hemolysin and the cells are added. This tube is a control on the unit of complement and should show complete hemolysis. 4. A corpuscle control may be included, containing 0.5 c.c. of corpuscles and 3 c.c. of salt solution. It controls the tonicity of the salt solution and should show no hemolysis. Reading the Results. — The controls are first inspected. The corpuscle control should show no hemolysis and the hemotytic control be just hemolyzed. The last two tubes of each series are the serum control tubes, and the first tube containing 1 unit of complement may show incomplete hemolysis, while the second tube containing 2 units of complement shows complete hemolysis unless the serum is quite anticomplementary. 3 units The first six tubes of each series show whether or not the reaction is positive or negative, and if positive, the amount of complement absorbed. If tube No. 7 of the serum controls shows some inhibition of hemolysis, 1 unit is subtracted from the number of units of complement absorbed in the first six tubes, and the difference represents the amount of complement absorbed by antigen and syphilitic antibody. / regard the reaction MODIFICATIONS OF THE WASSERMANN REACTION 475 as positive when lysis is incomplete vrith 2 units of complement, in addition to the amount absorbed by the serum alone. More strongly reacting serums will absorb from 3 to 8 units of complement, and not infrequently more; these sera may be retested with 8, 10, 12, etc., units of complement, but the employment of these large doses routinely is not justified because of the large amount of complement used, and the complement-fixing power of the majority of sera are readily measured with 2 to 8 units. The method of reading is best shown in Table 15b and Fig. 117. Cases of syphilis progressing favorably with the administration of specific remedies show less and less complement fixation until a negative reaction is secured. A large number of comparative tests employing the original Wassermann and this reaction with the same antigen have shown that a serum yielding a -f + + + result in the original Wassermann reaction may show anywhere from 2 to 8 units of fixation with this technic. MODIFICATION OF NOGUCHI Among the large number of modifications of the original syphilis reaction that have been devised, that of Noguchi has proved of distinct value. In this method an antihuman hemolytic system is employed that eliminates one possible source of error, due to the natural antisheep amboceptor in human serum. Noguchi advocated the use of active serum for this test, with an antigen of acetone-insoluble lipoids. Active serum yields a more delicate reaction, but may give false or proteotropic complement fixation, especially when crude alcoholic extracts are used as antigens. Before I began using cholesterinized alcoholic extracts in making the Wassermann reaction I not infrequently found that the Noguchi test with active serum was more delicate than the Wassermann reaction, but with cholesterinized extracts the results ran closely parallel. It is a good practice to conduct both a Wassermann and a Noguchi test with each serum, as a negative Noguchi test with active serum is a better indication of the absence of syphilis than is a negative Wassermann reaction. A positive Wassermann reaction, however, is better evidence of the presence of syphilis than is a positive Noguchi reaction, because of the possibility of false complement fixation occurring in the latter when active serums are used. I may state, however, that when a good antigen of acetone-insoluble lipoids is used, the percentage of false reactions is relatively small, being less than 2 per cent. The Noguchi test, on the other hand, may be conducted with inactivated serums, when the danger of false reactions is removed, but the delicacy of the test is likewise diminished, so that it more closely approaches the Wassermann reaction. Noguchi endeavored to simplify the technic of the syphilis reaction by preparing complement, antigen, and amboceptor dried on filterpaper. These were titrated and so adjusted that a certain measure of paper represented the required amount of each reagent. In this manner it would be possible for a large central laboratory to prepare and standardize these reagents, putting them up ready for use in the simplest possible form, and thus making them available for the practising physician. Complement, however, deteriorates so rapidly that the paper is useless unless it is freshly prepared. The antigen slips likewise deteriorate, but not so rapidly as the complement; the amboceptor, however, is well preserved by this method, and forms a simple method for titrating and handling this important reagent. Technic of the Noguchi Modification. — (1) Complement is furnished by the fresh, clear serum of the guinea-pig, put up in 40 per cent, solution, prepared by diluting 1 part of serum with 1J^ parts of normal salt solution. Dose 0.1 c.c. (5 drops from a capillary pipet). Whenever possible it is always best to use a mixture of the serums from two or more guinea-pigs. 2. Human Corpuscles. — These are washed three times with normal salt solution, and used in dose of 1 c.c. of a 1 per cent, suspension. To a graduated centrifuge tube containing 9 c.c. of sterile 2 per cent, sodium citrate in normal salt solution add 1 c.c. of blood and shake gently. This amount of blood is easily secured by pricking the finger with a lancet and collecting the blood in the centrifuge tube up to the mark 10. This is centrifuged thoroughly, and the supernatant fluid drawn off. More saline solution is then added to the corpuscles stirred up and the mixture centrifuged. The washing is repeated once more, and the supernatant fluid discarded. The corpuscles are then suspended in sufficient salt solution to make a total volume of 100 c.c. 3. Hemolytic Amboceptor. — Antihuman hemolysin is prepared by immunizing rabbits with human cells, as described on p. 72. It is a difficult matter to secure a potent amboceptor; human erythrocytes are more toxic than sheep's cells for rabbits, and most animals produce but small amounts of the amboceptor. Hemagglutinins are produced inV large amounts, and when using a low titer hemolytic serum, the testcorpuscles are quickly agglutinated in small dense masses that are broken up with difficulty and that interfere greatly with hemolysis. With serums having a titer of 1 : 1000 or over, the agglutinins are not so much in evidence; a satisfactory reaction is best observed, therefore, with a potent amboceptor (1 : 1000) serum. The hemolytic serum may be preserved in 1 c.c. ampules after adding an equal part of glycerin, and a stock dilution prepared and titrated in the usual manner. The serum is also well preserved dried on filter-paper, as described on p. 80. A trial titration should always be made to determine the potency of the serum before the paper slips are prepared. // paper amboceptor is used, the uniform rule of titrating it with the complement and corpuscles on hand should be observed before the actual tests are made. This is done chiefly because, where one guinea-pig serum is used for complement, it may occasionally happen that the serum is less active than usual, so that if fixed doses of complement and amboceptor are used, the reactions may at times prove to be incomplete and inaccurate. The process of titration is so simple that any one may readily conduct it, and thus fulfil the most important requirement of any complement-fixation test, namely, adjustment of the complement, amboceptor, and corpuscles to one another. Titration of Serum Hemolysin. — Prepare a 1 : 100 dilution by mixing 0.1 c.c. of immune serum (inactivated) with 9.9 c.c. of saline solution. To a series of six small test-tubes add increasing amounts of this diluted serum as follows: Sufficient saline solution is added to the first tubes of the series to bring the total volume up to 2 c.c. The tubes are then shaken gently and placed in the incubator at 37° C. for two hours (or one hour in water-bath at the same temperature) , during which time they should be inspected and shaken gently several times. At the end of the period of incubation that tube which shows just complete hemolysis contains one amboceptor unit, and double this amount is used in making the main tests. If the serum has a titer of less than 1 : 500, it should not be used either in preparing the amboceptor slips or in conducting the reaction. Titration of Dried Amboceptor Paper. — After the paper (S. & S. No. 597) has been evenly saturated with immune serum and dried, the sheets are cut into 5 mm. strips and standardized by placing increasing lengths of paper into a series of tubes as follows: One cubic centimeter of saline solution is added to each tube, and the mixture shaken gently and incubated at 37° C. for two hours or one hour in a water-bath. At the end of this time the tube just completely hemolyzed contains one amboceptor unit, and in performing the test double this amount is used. (See Fig. 118). This titration should always be conducted before the actual tests are set up, as is the rule in conducting the Wassermann reaction. When the titer of the paper is known, it may not be necessary to set up all the tubes of the foregoing series, as a few only are necessary to determine if the same amount of paper as was used in the previous tests will suffice with the new complement and corpuscle suspension at hand. All titrations and the main tests may be conducted in a water-bath (37° C.). With the aid of a good thermometer a satisfactory bath is easily improvised. In fact, I believe that better results are secured in the water-bath than in the incubator. It is possible, therefore, to conduct these reactions in a perfectly satisfactory manner without the aid of an expensive incubator. 4. Antigen. — Acetone-insoluble lipoids (Noguchi) are to be used exclusively if the tests are conducted with active serums. When heated serums are used, any extract may be employed, as in making the Wassermann reaction, but the same antigen gives excellent results, and I use it exclusively in conducting the Noguchi reaction with both active and inactivated serums. The antigen must be titrated as usual, and its anticomplementary hemolytic and antigenic properties determined. According to Noguchi, an extract is satisfactory if it is antigenic in 0.02 c.c. of a 1 : 10 dilution, and not anticomplementary or hemolytic in amounts under 0.4 c.c. (1 : 10). In conducting the tests five times the antigenic unit, or 0.1 c.c., is employed; this dose is at least four times smaller than the anticomplementary unit, and is therefore safe and satisfactory. The antigen is best preserved in methyl alcohol, as described on p. 446. Dried on paper and properly preserved in sealed tubes in a cold place it will retain its activity for several months, but as a general rule it is best to use fresh emulsions of the alcoholic solution. Titration of Antigen. — The anticomplementary, hemolytic, and antigenic doses of an extract are determined in the same general manner as was described under the Wassermann reaction. 1. Anticomplementary Titration. — A portion of the stock alcoholic solution of acetone-insoluble lipoids is diluted with 9 parts of saline solution. This is the emulsion that is employed in conducting the Noguchi reaction, and contains 0.3 per cent, of the original lipoidal substances. c.c. of the alcoholic solution with 3.6 c.c. of saline solution. Into a series of seven small test-tubes place increasing amounts of this emulsion as follows: 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0 c.c., add 0.1 c.c. (5 capillary drops) complement (40 per cent.) to each; also 1 c.c. of a 1 per cent, suspension of corpuscles and sufficient saline solution to make the total volume in each tube about 2 c.c. Incubate at 37° C. for one hour (one-half hour in water-bath), and add two units of amboceptor. Shake the tubes gently and reincubate for two hours (one hour on water-bath). That tube showing beginning inhibition of hemolysis contains the anticomplementary dose, which should not be under 0.4 c.c. In the tubes containing the larger doses slight hemolysis may be noticed, which is evidence of the hemolytic action of the extract. An eighth tube should be included, containing 0.1 c.c. diluted complement, two units of amboceptor, and 1 c.c. of the corpuscle suspension. This is the hemolytic control and should show complete hemolysis. 2. Antigenic Titration. — Since the extract is likely to have a high antigenic value, it is necessary to dilute the antigen still further by placing 0.5 c.c. of the foregoing emulsion in a test-tube and .adding 4.5 c.c. of saline solution (1 : 100 dilution of the antigen). Into a series of six test-tubes place increasing amounts of this emulsion as follows: 0.05, 0.1, 0.2, 0.3, 0.4, 0.5 c.c. To each tube add four drops (0.08 c.c.) of inactivated or one drop (0.02 c.c.) of fresh active syphilitic serum; also 0.1 c.c. (five capillary drops) of complement (40 per cent.) and 1 c.c. of 1 per cent, corpuscle suspension. Then add sufficient salt solution to bring the total up to 2 c.c. Two controls should be included: (1) The serum control, containing the dose of serum, 0.1 c.c. of the complement, 1 c.c. of corpuscle suspension, and saline solution; (2) the hemolytic control, containing at this time 0.1 c.c. of complement, 1 c.c. of corpuscle suspension, and sufficient saline solution. All tubes are incubated for one hour at 37° C. (one-half hour in water-bath), after which two units of amboceptor are added to each tube. The tubes are then shaken gently and reincubated for two hours (one hour in water-bath). At the end of this time the two controls should be completely hemolyzed, and in the series proper that tube showing just complete inhibition of hemolysis contains one antigenic unit. Usually the first and second tubes show some inhibition of hemolysis, and in the third and other tubes hemolysis is completely inhibited. In this case 0.2 c.c. of this emulsion would be one antigenic unit ( = 0.02 c.c. undiluted antigen) • five times this amount equals 0.1 c.c. of the first emulsion (1:10), which is the amount to be used in making the main tests. be made only about once a month. If paper antigen is employed, both titrations are conducted in exactly the same manner by adding increasing lengths of a strip of dried paper 5 mm. in width, impregnated with the antigen. 5. Fluid to be Tested. — If active serum is used, it should be fresh, free from hemoglobin, and preferably not over twenty-four hours old. The dose is 0.02 c.c., or one capillary drop; inactivated serums are used in doses of 0.08 c.c., or four capillary drops. Cerebrospinal fluid is used unheated in doses of 0.2 c.c., or 10 capillary drops. Sufficient blood for this test may be collected in a Wright capsule. (See p. 33.) 6. The Test. — The complement, amboceptor, antigen, and serums may be conveniently measured by drops from a capillary pipet (Fig. 2). In placing a drop the pipet should be held uniformly at an angle of 45 degrees, or else the size of the drop will differ, depending on whether the pipet is held vertically or horizontally. place five drops (0.1 c.c.) of antigen emulsion (alcoholic solution, 1 part, with saline solution, 9 parts); then add five drops (0.1 c.c.) of complement (40 per cent.) to all the tubes. Into each of the first pair of tubes place one drop (0.02 c.c.) of active or four drops (0.08 c.c.) of inactivated patient's serum, and mark the front tube with the patient's name. To each of the second pair of tubes add an equal amount of syphilitic serum known to give a positive reaction (positive control), and to each of the third pair add normal serum known to give a negative reaction (negative control) . Mark the tubes in the front row of each pair respectively. The front tube of the fourth pair is the antigen control, and the rear tube the hemolytic control, and each should be so labeled. Into each tube place 1 c.c. of the 1 per cent, corpuscle suspension and 1 c.c. of saline solution, making the total volume in each tube about 2 c.c. Shake each tube and incubate at 37° C. for one hour (half an hour in the water-bath). At the end of this time add two units of amboceptor to each tube, shake gently, and reincubate for two hours (one hour in the water-bath). During this time the tubes should be shaken gently once or twice to break up any masses of agglutinated corpuscles. The following chart, after Noguchi, illustrates the various steps to be taken in making the test with one patient's serum. Of course, any number of serums may be examined with the same controls (Fig. 119). At the end of the second incubation, or after two hours more at room temperature, the tubes are inspected. The antigen and hemolytic system controls, as well as all the rear tubes or serum controls, should be completely hemolyzed. The first tube containing a known syphilitic serum shows inhibition of hemolysis; the front tube containing normal serum is completely hemolyzed; the front tube containing the patient's serum shows complete inhibition of hemolysis (strong positive), varying degrees of inhibition (moderately or weakly positive), or is completely hemolyzed (negative) . The results may be recorded and reported after the same manner described on p. 464. Craig1 employs a technic differing from the original Wassermann reaction in the use of a human hemolytic system in place of a sheep hemolytic system, and in a proportional reduction in the quantities of reagents used. Alcoholic extract of syphilitic liver is generally employed as antigen, although cholesterinized extracts of normal heart muscle have been found equally satisfactory.2 Vedder3 has also used Craig's method in standardizing the Wassermann reaction for use in the military service, and it is widely used in the Army with satisfactory results. Bauer does not use rabbit-sheep amboceptor, but takes advantage of the antisheep amboceptor normally present in variable amounts in a large proportion of human serums. Although this test is quite delicate, the quantity of natural amboceptor in human serums is too variable a factor to be depended upon, and the modification is not, therefore, in general use. In conducting the syphilitic reaction Hecht4 utilizes not only the natural antisheep amboceptor in human serum but also the native hemolytic complement. The serum must be perfectly fresh and, of course, is used unheated. This modification has been said to be more delicate than the Wassermann reaction because none of the syphilis antibody is destroyed or complementoids produced, as presumably will occur during inactivation (heating) of a serum. In my experience this test has proved quite delicate, but is open to the same error that may occur whenever an active serum is used with a crude alcoholic organic extract as antigen — i. e., the appearance of false positive or proteotropic reactions. As with the Noguchi reaction, using active serum, a negative Hecht-Weinberg test has considerable diagnostic value in excluding syphilis; a positive reaction must be, however, carefully controlled. In performing the test I always use an extract of acetone-insoluble lipoids as antigen. Since in the original Hecht-Weinberg1 test there is no way of determining beforehand the amount of sheep corpuscles a serum may hemolyze, Gradwohl2 has modified the technic so that the hemolytic index of each serum is determined before the corpuscles are added to the main tubes. I conduct this test as follows :8 Nine small sterile test-tubes (10x1 cm.) are arranged for each serum and properly labeled; into each is placed 0.1 c.c. of fresh unheated serum. To the first five tubes are added respectively 0.1, 0.2, 0.3, 0.4, and 0.5 c.c. of a 5 per cent, suspension of washed sheep cells; to the sixth, seventh, and eighth tubes are added 1, 2, and 3 units of antigen respectively, as determined by titration. The last or ninth tube serves as the serum control. Sufficient normal salt solution is added to each tube to bring the total volume to 1 c.c. After one hour's incubation at 37° C. the hemolytic index of each serum is read in the first five tubes of each series (that is, the largest dose of corpuscles just completely hemolyzed by each serum) and one-half the indicated doses of corpuscles added to the remaining four tubes of each series. After re-incubation for one-half to one hour, according to the hemolysis of the controls, the results are read and recorded as in the Wassermann reaction. The antigen titrations are very important because the activity of human serum is quite sensitive to the inactivating influence of tissue extracts. No antigen should be employed in this test without preliminary titration with human serum to determine its anticomplementary and antigenic units. The anticomplementary titration is conducted by placing in a series of eight test-tubes the following amounts of antigen of acetone-insoluble lipoids diluted 1 : 100: 0.2, 0.3, 0.4, 0.6, 0.8, 1.0, 1.2, 1.5 c.c., and 0.1 c.c. of the fresh and mixed sera of two non-syphilitic persons; normal salt solution is added to 2 c.c. and the tubes incubated for an hour at 37° C., when one-half the index of cells for the serum is added to each tube. After a second incubation of an hour the anti- complementary unit is read as the smallest dose of antigen producing inhibition of hemolysis. The antigenic titration is conducted in the same manner with the serum of one or two syphilitic persons and the following doses of antigen (1 : 100) : 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 c.c. The antigenic unit is the smallest amount giving complete inhibition of hemolysis. Margaretta Stern devised a modification of the Wassermann reaction, using fresh active serum and the patient's complement, and overcoming non-specific reactions by using f to -\|- of the usual dose of extract, and three or four times the amboceptor unit. This method is open to defects inherent in the use of variable amounts of complement and excessive amounts of hemolytic amboceptor, which makes it impossible to test a specimen a few days after it has been collected. Tchernogubou proposed an antihuman hemolytic system with active serum. Blood is collected in sodium citrate, and therefore contains erythrocytes, complement, and syphilis antibody if the patient is luetic. Antigen is added, and after sufficient time has elapsed for fixation of complement to take place, antihuman amboceptor is added to test for free complement. There are many objections to this method, the chief ones being the variable amount of complement present in human serum, the large amount of hemolytic amboceptor required, the absence of a suitable control on the antigen, and the fact that old blood is entirely unsuited for making the test. Tchernogubou has also proposed a system in which the natural amboceptor and complement of human serum are utilized against guinea-pig corpuscles. These factors are so variable that this modified test has been largely abandoned. MODIFICATION OF DETRE AND BREZOVSKY In this modification an antihorse hemolytic system is used with rabbit's complement. The chief objections are the variations in the activity and fixability of rabbit complement, and the difficulty of obtaining horse blood. In addition to these, this method possesses no advantages over Wassermann's antisheep system. accurate quantitative test. (See p. 470.) They claim that with their modified technic the results secured are practically the same with the antiox and antisheep systems, although the human serums contain much less natural antiox amboceptor and, theoretically, therefore this system is better. More recently von Dungern has proposed a modification similar to that of Noguchi. Like Tchernogubou, he uses active serum only, and utilizes the patient's own blood-cells. The blood is defibrinated and used in doses of 0. 1 c.c. Complement in the human blood is disregarded, and is furnished by guinea-pig serum in dried-paper form. Alcoholic extract of syphilitic liver is used as antigen, and this opens up an avenue for false positive or proteotropic reactions to creep in. Antihuman amboceptor is prepared by immunizing goats, but, as Noguchi has shown, this amboceptor gives a much weaker hemolytic reaction than that derived from the rabbit. Von Dungern generally omits the important control with known syphilitic serum; there is no direct control on the antigen, and old bloods cannot be used. THE WASSERMANN REACTION IN THE VARIOUS STAGES OF SYPHILIS 1. In Primary Syphilis. — As would be expected, a certain degree of tissue change most occur before syphilis reagin appears in the blood. Even with the best technic there is a limit to the sensitiveness of the Wassermann reaction, so that while the reagin may be produced at the very onset of an infection, time and further tissue changes are required before sufficient reagin is produced to yield a complement-fixation reaction. Since, therefore, the results of the Wassermann reaction in primary syphilis are dependent upon the virulence of the infection, the time at which the reaction is made, and the delicacy of the technic, it is not surprising that the results of different investigators vary in the proportion of positive reactions obtained. While positive reactions have been said to have been secured before the appearance of the initial lesion, these are rare, and there is always the likelihood that an earlier infection was overlooked. A careful review of our own work and the literature upon this subject establishes the following: (a) A positive reaction may be secured during the first week after the appearance of the chancre. Craig has reported a positive reaction occurring five days after the appearance of the initial lesion. Levaditi, Laroche and Yamanouchi, and others have recorded many positive pearance. (6) In general, in primary syphilis the Wassermann reaction will be positive in about 80 to 90 per cent, of cases; where cholesterinized extracts are used as antigens, or with the Noguchi system, using active serum, the reactions are secured earlier and in a larger percentage of cases. Craig1 has reported 34 per cent, positive reactions during the first week after the appearance of the chancre; 57 per cent, during the second week; 67 per cent, during the third week; 76 per cent, during the fourth week, and 80 per cent, during the fifth week. (c) It is generally agreed that a diagnosis should be made as early as possible, and vigorous treatment instituted. A Wassermann reaction may be performed, and if it shows a positive result, this indicates the presence of syphilis, even if the lesion under suspicion is not specific, the reaction being due to a previous infection. A negative reaction, however, does not exclude syphilis, and if it is at all possible, a microscopic examination, using the dark-ground illuminator, should be made for the treponema. In primary syphilis a microscopic examination of the secretions of the lesion by a competent person is usually more valuable than the serum test; as a general rule, both examinations should be made, especially with patients in whom the chancre is almost healed or atypical. 2. In Secondary Syphilis. — It is in untreated cases of secondary syphilis that the remarkable specificity of the Wassermann reaction is so well demonstrated. The initial lesion may have been inconspicuous and hence have been overlooked, and the secondary lesions may be quite mild and inconclusive; in either case the Wassermann reaction will usually establish the diagnosis. (a) In untreated secondary syphilis the reaction is positive in from 92 to 100 per cent, of cases. In the examination of 437 serums from untreated cases Boas has never had a negative reaction, and my own experience has been the same. Craig reports 96 per cent, positive reactions. (6) With the serums of patients who have received some treatment the percentage of positive reactions will be slightly lower. Of 310 such cases examined by Boas, 97.6 reacted positively. The influence of treatment upon the reaction is to be remembered, and a single negative reaction does not by any means exclude the possibility of syphilis. 1 Amer. Jour. Med. Sci., 1915, cxlix, 41. (c) The intensity of the reaction does not bear any direct relation to the severity of the infection: a mild infection with indefinite signs may react quite strongly and absorb a large number of units of complement, whereas a severe case may react quite mildly. (d) In secondary syphilis without cerebral symptoms the cerebro-'/ spinal fluid is practically always negative (Plaut, Boas and Lind); conversely, cases showing cerebral involvement usually react positively. More recent work has shown that the cerebrospinal system is involved early and in a relatively large number of cases (Craig and Collins1). Udo J. Wile has found that about 30 per cent, of secondary syphilitics give a positive reaction with cerebrospinal fluid. 3. In Tertiary Syphilis. — It is probably in tertiary syphilis that the / Wassermann reaction has its greatest value. Lues is so diverse in character, and may be responsible for so many diverse clinical conditions, that the reaction has become well-nigh indispensable as a diagnostic aid. There is no limit to the time following infection in which positive reactions may not be found. positive in about 96 per cent, of cases. (6) In cases receiving more or less antispecific treatment the reactions are positive in about 75 per cent. In general, therefore, a positive reaction in tertiary syphilis may be expected in from 80 to 85 per cent, of cases. (c) In a large percentage of cases of syphilitic aortitis, aortic aneu- " rysm, aortic insufficiency, gummas of various organs, etc., the reaction is positive and possesses great diagnostic value. (d) The Wassermann reaction has been especially valuable in the study of the so-called parasyphilitic diseases. In general paralysis or paralytic dementia the serum reacts positively in about 100 per cent, of cases, and the cerebrospinal fluid reacts positively in about 92 per cent. The final and conclusive proof of the syphilitic nature of this disease has been furnished by Noguchi and Moore, who found the Treponema pallidum in sections of the brain. In certain cases of general paralysis the blood-serum may react negatively, whereas with the cerebrospinal fluid the reaction is positive. central nervous system is present. In untreated and active cases of tabes dorsalis the blood-serum reacts positively in from 96 to 100 per cent, of cases. In treated cases the number of positive reactions drops to about 40 to 50 per cent; in general, therefore, a positive reaction with the serums of tabetics may be expected in 73 per cent, of cases. With the cerebrospinal fluid the percentage of positive reactions is somewhat lower, being about 60 per cent. The positive Wassermann reaction is less constant in locomotor ataxia than in general paralysis, due probably to the fact that the former is more chronic and that intercurrent periods of arrest are more prone to occur. In cerebral syphilis the blood-serum, and particularly the cerebrospinal fluid, will react positively less frequently than in general paralysis. In some instances a positive reaction is found with the cerebrospinal fluid and not with the serum, a matter difficult to explain and believed to be due to the confining of the reacting substances in the subarachnoid space. On the other hand, the lesions are probably not brought in direct contact with the spinal fluid. There is much evidence to indicate that localization of syphilis in the nervous system is dependent upon a particular strain of Treponema pallidum; other strains appear to possess a special affinity for the visceral organs, bones, etc. (e) In tertiary syphilis not accompanied by lesions of the central nervous system the Wassermann reaction with cerebrospinal fluid may be positive in a relatively large percentage of cases. 4. In Latent Syphilis. — In cases of latent syphilis the Wassermann reaction may constitute the only evidence of the existence of the disease, and prompt institution of treatment may prevent the development of tertiary lesions, which are so likely to follow. When the spirochetes are few in number and are dormant, there is little tissue destruction or alteration, and, as a result, so little reagin is frequently present in the body-fluids that the Wassermann reaction will fail to detect the disease. (a) In 363 cases of early latent syphilis, or those included within a period of three years after infection, Boas found positive reactions in about 40 per cent. ; in latent cases of long standing, or in those following manifest tertiary lesions, the same investigator found 22 per cent, of positive reactions among those who had received proper treatment; of those receiving indifferent treatment, 74 per cent, reacted positively, giving a general average of about 48 per cent. Craig has found 67 per cent, positive reactions in latent syphilis. (6) The reaction with cerebrospinal fluid depends upon whether or not the central nervous system is involved in the syphilitic process. Of 104 latent cases of syphilis in whom the spinal fluid was examined by Altman and Dreyfus, positive reactions were found in about 10 per cent. 5. Congenital Syphilis. — The Wassermann reaction has thrown considerable light upon the subject of congenital syphilis. While, in general, the majority of cases react positively, the results are largely dependent upon the time when the examinations are made, a fact brought out by the highly instructive and systematic investigations of Boas and Thomsen. These investigators divided their cases into three groups: (1) Newly born children and their mothers; (2) two-year-old children; (3) older children with congenital syphilis. (a) Of 88 children born of syphilitic mothers and examined at birth, the reaction was positive in 31 and negative in 57 cases. Of the 31 positive cases, 4 showed no symptoms of syphilis for a period of observation covering from three to nine months, and it is possible that the syphilis reagin, and not the spirochetes, from the blood of the mother, passed into the circulation of the child; on the other hand, all four cases may have been examples of retarded congenital syphilis. The remaining 27 cases either developed symptoms of syphilis or died later with syphilitic manifestations in various organs. Of the 57 children reacting negatively at birth, 42 showed no symptoms of syphilis during a period of three months of observation; 2 died with evidences of syphilis in the internal organs; 13 developed symptoms after birth and gave positive reactions. It may therefore be stated that a Wassermann reaction of the mother and of the child at the time of birth in cases where syphilis of the mother is suspected has considerable prognostic value. A large majority of children reacting positively develop symptoms of syphilis; on the other hand, the majority reacting negatively remain healthy. While an examination of the mother alone does not warrant an absolutely definite prognosis for the child, in general it may be said that a positive reaction does not constitute a favorable prognostic sign for the child. (6) The Wassermann reaction has also shed new light upon the interpretation of Colics' law. Since the " apparently healthy mother of a syphilitic child could suckle the child without being infected, whereas the child is capable of giving syphilis to others," the most logical conclusion to draw is that the mother was gradually immunized against syphilis during pregnancy, whereas we now know that the majority of mothers show positive serum reactions and are really latent syphilitics; in not a few such instances tertiary lesions have developed at a later date. It is possible, however, for a syphilitic mother showing a positive Wassermann reaction to give birth to a healthy child. Of 46 mothers whose children showed no evidences of syphilis over a period of observation of three months, 17 reacted positively. Of 81 mothers giving birth to syphilitic children, 61 reacted positively, and many of these would naturally, in former years, have been regarded as examples of Colles' immunity and considered free of syphilis. In many instances the apparently, healthy child of a syphilitic mother that could not be infected by the mother (Profeta's law) has been shown by the Wassermann reaction to be in reality a case of retarded congenital syphilis, and that such children are not immunized, during intra-uterine life, either passively or by means of pallidum toxins, against syphilis, as has been so generally believed in past years. In other words, there appears to be no lasting passive immunity in syphilis; it is doubtful if the toxins of pallidum can pass between mother and child and immunize one or the other without actual infection with the spirochetes themselves taking place; that most examples of so-called immunity in syphilis in both the mother (Colles' law) and the child (Profeta's law) are due to the actual presence of pallidum in the tissues and are really latent infections. (c) In manifest untreated congenital syphilis of children one year or over in age the Wassermann reaction is positive in from 97 to 100 per cent, of cases. The clinical manifestations may be quite varied and clinically ill defined, so that the serum reaction possesses considerable diagnostic value. In most instances the reactions are quite strong, and while active treatment may improve local lesions, it is very difficult, indeed, to secure negative reactions. (d) In congenital mental deficiency and epilepsy the Wassermann reaction shows that syphilis pla3rs a larger part in the etiology of this condition than is generally supposed. A riot inconsiderable proportion of cases are of infectious origin, and that infection is syphilis. In Little's disease, which is regarded as due to rneningeal hemorrhage incidental to injury received during labor, the serum reactions have shown that not infrequently the hemorrhage has a syphilitic origin. quite confusing and contradictory. Following the original communications of Wassermann and Detre, and especially after it was demonstrated that the antigen need not be biologically specific, the subject was extensively investigated by various observers, who reported securing positive reactions in many different diseases, results that we now know must have been due largely to technical errors. At present it is known that positive Wassermann reactions may occur in a few diseases other than syphilis, but not to the extent that earlier investigators would have us believe. In most of the diseases yielding positive reactions the clinical symptoms are so marked that they may readily be differentiated from syphilis, and accordingly the Wassermann reaction is of unequaled and incalculable diagnostic value. Positive reactions have been reported mframbesia (yaws), in which the causal microorganism, the Spirochaeta pertenuis, is morphologically almost indistinguishable from Spirochaeta pallidum. In leprosy of the tuberous type positive reactions are frequently found, but cases of anesthetic leprosy usually react negatively. Positive reactions have been reported in cases of malaria during the febrile stage, when parasites are present, although the majority of cases react negatively. In my own series of 11 cases all the reactions were negative. Positive reactions have also been found in some cases of relapsing fever. In scarlet fever the Wassermann reaction is uniformly negative. Owing to the original communication of Much and Eichelberg, however, in the minds of many this disease is prominently associated with a positive reaction. While it is true that a positive reaction is very rarely found, it is almost impossible entirely to exclude a diagnosis of congenital lues, at least in some of these cases. In my own series of 250 cases examined by the Wassermann and Noguchi methods, with antigens of alcoholic extract of syphilitic liver and acetone-insoluble lipoids, the reactions were positive in 5 cases, or 2 per cent. Similar results have been secured by Boas, Browning and Mackenzie, and others, so that it may be said that the reaction in scarlet fever is uniformly negative. It is also to be remembered that occasionally, or in about 1 to 2 per cent, of cases, a positive reaction may follow ether or chloroform anesthesia, but that this will later disappear. In pellagra Fox, and later Bass, have found occasional positive reactions. Craig and Nickols have reported that blood drawn from Wassermann positive persons immediately after an acute alcoholic debauch may yield a negative result. Normal cerebrospinal fluid or the fluid from persons with ordinary non-syphilitic diseases reacts negatively. Positive reactions have been reported in leprosy and in frambesia. THE EFFECT OF TREATMENT UPON THE WASSERMANN REACTION Citron originally observed that during the mercurial treatment of syphilis the Wassermann reaction gradually became weaker, and finally disappeared. He also found that treatment was best governed by the serum reaction, and that it should be persisted in until a negative reaction was secured. His observations have in the main been abundantly confirmed by various observers the world over, although the extensive series of observations now on record have given us a fuller understanding of its principles. The Wassermann reaction is the most constant and delicate single symptom of syphilis, and whenever a serum is found to react positively, antisyphilitic treatment is indicated, and should be persisted in until the reaction becomes negative and remains so for a sufficiently prolonged period of observation. It is now quite generally believed that a persistently positive reaction indicates the presence of living spirochetes, and that treatment should be continued until the blood reacts negatively. The reports of observers from all parts of the world indicate quite clearly and conclusively that the schematic, symptomatic, intermittent, and hard and fast rules of treatment of former days are not sufficient. They would also tend to show that the Wassermann reaction is the most delicate symptom and the last to disappear, and that treatment should be continued until this reaction disappears entirely and permanently. It has been abundantly proved, however, that in syphilis a single negative reaction is not sufficient or definite evidence that a cure has been effected, for the disease may recur after treatment is discontinued, at least to the extent that the Wassermann reaction reappears, followed by clinical manifestations. It is necessary, therefore, that suecessive examinations be made during a period of at least two years, and off and on during the remainder of life. Recent work indicates that certain strains of Spirochseta pallida have an apparent selective affinity for the tissues of the central nervous system; the Wassermann reaction with blood-serum may be negative, whereas with the cerebrospinal fluid it may be positive. In cases, therefore, of tertiary syphilis, at least, it is advisable to examine the spinal fluid and continue treatment in case it shows a positive Wassermann reaction. It should be the object of treatment, in every case, not only to dissipate the external and obvious lesions of the disease, but to produce a condition of the blood in which the Wassermann reaction is permanently negative. It is quite generally agreed that the older methods of treatment, consisting of the administration of mercury and the iodids over fixed and arbitrary periods of time, or until all manifest symptoms have disappeared, are insufficient, and that the criteria by which the effects of treatment can best be judged are: (1) Continued absence of symptoms, and (2) permanent negative Wassermann reactions. It is to be remembered, therefore, that while a single negative reaction is a satisfactory indication of the progress of treatment, it does not signify that a permanent cure has been effected. The Wassermann reaction cannot be regarded as sufficiently delicate to indicate that a single negative reaction means that a patient is totally free from all spirochetes, for in some instances the reaction and the clinical symptoms may recur after the treatment has been suspended, but the reaction is the first symptom to reappear and the earliest indication of an impending lesion. For all practical purposes the occurrence of a negative reaction after treatment indicates either complete destruction of all the spirochetes, or at least that the parasites are being held in abeyance and rendered potentially harmless. It is, accordingly, reasonable to regard the Wassermann reaction as the most delicate indicator of generalized spirochetal infection or the assumption of spirochetal activity. A positive reaction indicates that serious effects and gross local lesions are likely to occur at any time, and that treatment should be continued. For all practical purposes a continued absence of symptoms and a permanently negative reaction are strong presumptive evidences that a cure has been effected. The serum should be tested every six months during the treatment, and at periods of at least six months to a year after treatment has been discontinued for several years. Persistently positive reactions during treatment would indicate that more active measures or a change in therapy are needed. The occurrence of a positive reaction after treatment has been discontinued is an indication for its resumption. For a control on treatment the Wassermann reaction should be made as delicate as possible, for while more prolonged treatment may be somewhat irksome to the patient, it is clearly indicated as a preventive of serious after-effects, especially of involvement of the central nervous system. It is in this branch of the work I have found that the use of sensitive cholesterinized extracts as antigens in making the Wassermann reaction or the Noguchi modification with the use of active serum, of great value as the most delicate indicators. One fact is to be clearly emphasized, namely, that the earlier energetic treatment is begun, the more likely it is that a permanent cure will be effected. Energetic treatment with mercurials or salvarsan, or, better, with a combination of both, begun early and continued long, will in the majority of cases restore the serum to its normal condition. In general, the greater the interval of time allowed to elapse between infection and institution of treatment, the more difficult it is to restore the serum to normal. Tertiary cases are cured only as the result of most persistent treatment, and not infrequently in congenital syphilis, locomotor ataxia, and general paralysis all one can hope to accomplish is to check the progress of the disease. The most favorable cases are those in which early diagnosis is made possible by clinical manifestations, preferably confirmed by a demonstration of pallidum, and in which treatment is undertaken before the serum has begun to react positively, and in which the reaction remains negative throughout. Treatment will, however, at least influence the Wassermann reaction in practically all stages of syphilis. In a series of 435 cases of syphilis in all stages reported by Boas, a negative Wassermann reaction was secured in no less than 80 per cent., and all but one of the remaining cases showed a weaker reaction. The figures of different observers are not all so favorable as these, a factor dependent to some extent, at least, upon differences in the technic of the reaction. In general, however, Boas' observations have been confirmed by other competent workers. The effect of any treatment is greatly influenced by the individuality of the host, certain persons possessing tissues more amenable to the effects of the therapeutic agent than those of others. The therapeutic effect is also dependent upon the virulence of the parasite and the apparent selective affinity of certain strains of pallidum for particular organs, and upon the method of treatment selected. The influence of salvarsan and neosalvarsan as agents in the treatment of syphilis is considered in more detail in the chapter on Chemotherapy. My experience has shown that the earlier belief in the complete sterilization of the human patient by a single dose was generally unfounded, and that repeated smaller doses of the drug, used in conjunction with mercurials, are necessary. Potassium iodid alone may favorably influence the clinical symptoms and weaken the Wassermann reaction in a small percentage of cases, and the same result has been observed with such arsenical preparations as Fowler's solution, atoxyl, arsacetin, and arsenophenylglycin. It is to be remembered that, during or immediately after active treatment with salvarsan or mercury, the Wassermann reaction may be negative, even though the patient is not cured. As a general rule, a negative reaction under these conditions should not be considered of value unless all treatment has been omitted for at least two weeks; even then the test, if negative, should be repeated a month or so later. Craig has recently drawn attention to the fact that in frank untreated cases the degree of the reaction may vary within wide limits, and this is especially true if the patients are receiving active treatment. Provocatory Stimulation. — Paradoxic as it would at first appear, antisyphilitic treatment may convert a negatively reacting serum into a positive one. In not a few cases of latent syphilis reacting negatively the administration of a specific spirillicidal agent, such as mercury or salvarsan, is followed by positive reactions, due probably to the liberation of endotoxins from destroyed spirochetes or to a stimulation of the spirochetes by a dose of drug that did not suffice to kill them. This condition is analogous to the Herxheimer reaction, or the aggravation of skin lesions sometimes observed to follow the administration of mercury or salvarsan. The fact possesses practical value, for in cases where lues is known to have been present or is strongly suspected, and the Wassermann reaction is indefinite or negative, the administration of 0.3 to 0.4 gram of salvarsan or neosalvarsan, followed by a Wassermann reaction three days later, may now show a positive reaction and thus indicate a latent syphilis requiring further treatment. in the treatment of syphilis. The reaction may be of great value in determining the diagnosis of extragenital sores and of atypical lesions in all stages of syphilis. A negative reaction, however, has less value than a positive one, and whenever possible, a microscopic examination of the secretions with the dark-field illuminator should be made in order to confirm the diagnosis. In early latent syphilis, after the initial lesion has healed, and before the secondary eruption appears, the Wassermann reaction is frequently the only means of making the diagnosis, especially if the chancre has been small, atypical, and practically neglected. Indefinite symptoms and clinical unrecognizable cases constitute a considerable proportion of cases of syphilis, and, as is true in all other infections, this class constitutes the greatest menace to public health. Many patients are sincere in denying knowledge of infection and early symptoms may be overlooked, the Wassermann reaction being the sole means of diagnosis and serving in this connection as an invaluable aid. negative. In the late latent and tertiary stages of syphilis the Wassermann reaction may be the only available basis on which to establish a diagnosis. When one remembers how varied are the clinical manifestations of chronic syphilis, how wide-spread is the disease, and how frequently the reaction establishes the true diagnosis, the reaction must be regarded as being of great value and as an indispensable diagnostic aid. It must not be forgotten that patients showing an early involvement of the central nervous system, and even those showing no such symptoms, may react negatively with blood-serum and positively with spinal fluid; in all such cases the spinal fluid should be examined whenever possible. A positive reaction occurring in aborting women is an indication for treatment and may protect the fetus. Similarly a positive reaction in either parent of a seemingly healthy infant is an indication for treatment of the child especially if the mother reacts positively. In this connection, however, one point is worthy of special emphasis, namely, that although a positive reaction indicates that the patient is luetic, it does not necessarily mean that a particular lesion is syphilitic. For example, a person may be luetic and yet have a cancerous ulceration of the larynx. The mere fact that the lesion does not improve under antisyphilitic treatment does not detract from the value of the Wassermann reaction, but is a warning that more care is required in making the clinical examination. I have seen a number of such cases in which a positive Wassermann reaction was held a priori as evidence of the syphilitic nature of a lesion that later proved to be either malignant or tuberculous. A weak positive reaction, associated with an active ulcerating lesion, very frequently indicates that the lesion is not syphilitic, for active lesions usually yield strongly positive reactions. In this connection may also be mentioned the growing importance the Wassermann reaction has assumed in life-insurance examinations. Statistics show that from one-tenth to one-third of all persons infected with syphilis die as the results of the disease, and the death-rate among 5000 syphilitics accepted for insurance was one-third over expectation (Brockbank). An important question, especially from the standpoint of therapeutics is : Does a positive reaction invariably indicate the presence of living spirochetes? May the reaction remain positive for an indefinite time after the patient has been cured, just as agglutinins and antitoxins may persist in the blood for some time after recovery from typhoid fever and diphtheria has taken place? The sum total of the experience of investigators from all parts of the world would indicate that a persistently positive reaction means the presence of living spirochetes somewhere in the body. The lesions may not be active; the patient, while clinically healthy, may be infective, and is always subject to possible recurrences of clinical syphilis. Although gummas are slightly infectious, it is now known that they contain living spirochetes, and the former view, which regarded them as sequels, rather than as actual active lesions of syphilis, is no longer tenable. Just how long the reaction may remain positive after the patient is actually cured and all spirochetes are dead is, of course, difficult to state, but experimental studies on the lower animals has shown that the reagin disappears somewhat quickly under these conditions. Although a persistently negative reaction is of good prognostic importance, it is not so conclusive in the information it yields as is a positive reaction. In other words, an occasional active lues may react negatively, and not infrequently active syphilitic lesions are found at autopsy in persons whose blood reacted negatively during life. While it is true that great harm may result from a false positive diagnosis due to faulty technic, yet it must be admitted that the Wassermann reaction is not too delicate, and that we are just as prone to err on the side of securing too many negative reactions. Every effort should be made to render the test as delicate as is possible with specificity. While the value and dependability of the Wassermann reaction are based upon skilful technic that will eventually limit the performance of the test to specially trained persons in central laboratories, every effort should be made to render accessible to all persons this valuable diagnostic test of a disease that has such great social and economic importance. At present many persons are unable to afford the expense of a number of tests, or even of one test, as required in the modern treatment of this disease. This deficiency should be corrected, and the test made available in all free dispensaries, especially those under the supervision of a Social Service Department. Specific Complement Fixation in Bacterial Diseases. — As has been stated elsewhere, the first complement-fixation tests were performed by Bordet with bacterial antigens and antiserums (pest and typhoid). Following the application of the principles of complement fixation in the serum diagnosis of syphilis, it was but natural that the possibilities of this method as a general means of diagnosis soon became appreciated, and in a short time numerous infections were studied. Probably in no disease has complement fixation proved so constant or so valuable a diagnostic procedure as in syphilis. In this condition the peculiar lipodophilic reagin is largely responsible for the marked fixation of complement, and from our present knowledge on the subject we learn that this phenomenon has practically no analogy in any other disease except frambesia. With few exceptions bacterial antigens are likely to yield weaker and more inconstant reactions. This is due to the fact either that our antigen lacks a more available and specific antigenic principle, or that the amount of complement-fixing bodies is small and variable. For these reasons it becomes apparent that the preparation of antigen and delicacy of technic are highly important factors. Preparation of Bacterial Antigens. — Either the endotoxins or whole bacterial body may constitute the main portion of an antigen. Most recent efforts have aimed thoroughly to disorganize the bacterial cell in order to liberate the endotoxic substances that pass into solution and constitute the antigen. Experience has frequently shown, however, that the protein substances of the bacterial cell itself possess antigenic properties, and accordingly I have generally found that antigens composed of cells and the products of cellular activity are usually more satisfactory than those prepared of the endotoxic substances alone. As a general rule, bacterial antigens should be polyvalent — i. 6., made up of a number of different strains of the same microorganism. Recent researches in bacteriology tend to show that different strains of the same microorganism have particular and more or less individual pathogenic and sometimes biologic characteristics, and it is reasonable to assume that the antibody will likewise show individual properties and a special affinity for its particular antigen. When, therefore, one antigen is being used in complement-fixation work, the results are more likely to be satisfactory if a large number of different strains are included in the antigen, with the hope that at least one of them will show a particular affinity for the antibody in the patient's serum. Bacterial antigens may be prepared in various ways. First Method. — Cultures are grown in a suitable fluid medium, such as plain bouillon, for forty-eight hours, or upon a solid medium, and washed off with a suitable quantity of normal saline solution. The culture or emulsion is shaken for an hour or so to break up the clumps, and then heated to 60° C. for an hour. It is preserved by the addition of 1 per cent of glycerin and 0.5 per cent, of phenol. This constitutes the simplest bacterial antigen. It is composed of both bacterial cells and the products of bacterial activity, and frequently yields uniform and satisfactory results. Second Method. — Cultures are grown on a suitable solid medium for from twenty-four to forty-eight hours. Growths are removed by adding sufficient distilled water or normal saline solution to yield a milky suspension. The emulsion is heated to 56° C. in a water-bath for one hour, followed by one hour at 80° C., and shaken mechanically with glass beads for twenty-four hours, to facilitate disintegration. It is then filtered through paper pulp and a sterile Berkefeld filter with a neutral reaction, or thoroughly centrifugalized; the filtrate is then heated at 56° C. for one-half hour on each of three successive days to sterilize, and preserved with 0.5 per cent, phenol and used as antigen after being diluted and made isotonic with 1 part of 9 per cent, salt solution to 9 parts of the antigen. Third Method. — Cultures are grown on a solid medium, washed off with normal saline solution, and the emulsion centrifuged thoroughly. The sediment is dried over sulphuric acid or calcium chlorid, and the dried material thoroughly ground with crystals of sodium chlorid. Sufficient distilled water is then added to render the solution isotonic, and so that it will contain about 0.05 gram of dried material in each cubic and used as antigen. Fourth Method. — Cultures are grown on a solid medium and washed off with normal saline solution. Saline suspension is then precipitated with an equal quantity of absolute alcohol and centrifugalized. The sediment is dried in vacuo over sulphuric acid, weighed, and ground into a fine powder with sufficient crystals of sodium chlorid to make a 2 per cent suspension of dried material in isotonic saline solution. This stock suspension is not filtered or centrifuged, but is further diluted with saline solution, and constitutes the antigen (method of Besredka, modified by Gay). The actual amounts of dry antigenic substance contained in 1 c.c. of various dilutions are as follows: Standardizing Bacterial Antigens. — After an antigen has been prepared it is standardized by determining the anticomplementary dose — i.e., the amount of antigen that just begins to show inhibition of hemolysis due to non-specific complement fixation. This dose is easily determined by adding increasing amounts of antigen to a series of testtubes with a constant dose of complement in each. As a general rule, it is well to add to each tube a constant dose of fresh normal inactivated serum, e. g.} as 0.1 to 0.2 c.c., when the anticomplementary action of serum alone is allowed for. I would emphasize the necessity of doing this in experimental work with rabbit, dog, or any other animal serum. After incubating for one hour, two units of hemolytic amboceptor and 1 c.c. of corpuscle suspension are added to each tube, and the tubes are reincubated for an hour or two and the reading made. In the main test, one-quarter to one-half the anticomplementary unit may be used, as this amount is known to be free from any power of nonspecific complement fixation. The former dose is, of course, safer than the latter. The standardization may be completed by determining the antigenic dose of the antigen by titrating with a suitable and constant dose of specific immune serum. This titration is conducted by placing in a series of test-tubes increasing doses of antigen with a constant dose of heated immune serum (usually 0.1 c.c.) and a constant dose of comple- PRINCIPLES OF COMPLEMENT FIXATION WITH BACTERIAL ANTIGENS 501 ment. After an hour the proper dose of hemolytic amboceptor and corpuscles is added. The readings may be made an hour or two later, or after the tubes have been allowed to settle in a refrigerator. That tube showing just complete inhibition of hemolysis contains the antigenic unit. For the main test it is well to use double this amount, providing this dose is not more, and preferably less, than half the anticomplementary unit. The antigenic titration is not always satisfactory, for when an artificial immune serum is used the concentration of antibodies may yield a much stronger reaction than one would expect in testing human serums. Further than this, the antibody content in antiserums varies considerably so that the antigenic unit fluctuates according to the particular serum used in making the titration. In general, therefore, it is sufficient to determine the anticomplementary unit and to use half or quarter this amount in performing the main test. stood. After making considerable comparative studies with various methods, I am convinced that, in the final analysis, a simple technic is best. I titrate the complement or use a relatively small but safe dose of complement,— 1 c.c. of a 1 : 20 dilution ( = 0.05 c.c. undiluted serum), — and titrate the hemolytic amboceptor with this constant dose or unit of complement and the corpuscle suspension. This titration is made each time the reactions are performed, and with each and every complement serum and corpuscle suspension. In this way differences in the activity of different guinea-pig serums are readily detected and adjusted. If exactly one unit of complement or amboceptor is used in conducting the main test, the controls are not likely to be completely hemolyzed unless the serum contains natural antisheep amboceptor, for the serum alone will probably be slightly anticomplementary. For this reason I am accustomed to use 2-unit doses of complement or amboceptor, and I secure reactions that are very delicate and yet sharp and clear cut. If one wishes to use exactly one unit of complement and one unit of amboceptor, the serum and antigen alone should be controlled, as in the fourth method of performing the Wassermann reaction (p. 470). I frequently use this technic in the gonococcus-fixation test, but, as a rule, I have found the simpler technic herein given equally sensitive and reliable. In this chapter are considered the main bacterial infections in which complement fixation has been shown to possess value as a means of diagnosis. Complement fixation has also proved of value in the diagnosis of animal parasitic diseases, such as echinococcus infection, and in the differentiation of the proteins. With each of these the special methods for preparing the antigen, titrating the antigen, and conducting the test are given. Complement Fixation in the Differentiation of Microparasites. — Several investigators have applied the technic of complement-fixation in a study of the relationship and differentiation of closely related bacteria, spirochetes, trypanosomes, and other microparasites. These studies have usually been made by immunizing rabbits with a particular strain and using the immune serum in complement-fixation tests with antigens of the other microparasites under study. As a general rule complement-fixation is most marked with homologous antigen and antiserum; relationship is studied according to whether or not complement-fixation occurs with the other antigens. Besredka,1 Foix and Mallein,2 Swift and Thro3 have reported that immune amboceptors specific for different strains of streptococci can be demonstrated by means of the complementfixation test. In my own work with five strains of streptococci,4 with the specific purpose of studying the relationship of the streptococcus commonly found associated with scarlet fever to the group of streptococci, I found that differentiation among these was possible when using high dilution of the immune sera, but in lower dilutions differentiation was not found by means of complement-fixation tests, the re- COMPLEMENT FIXATION IN GONOCOCCUS INFECTIONS 503 suits indicating either that this scarlet fever streptococcus belonged to the common group of streptococci or that the complement-fixation test was a group reaction. In a similar study of the diphtheria group of bacilli I1 found that .the pseudodiphtheria bacillus could not be differentiated from other members of the group by complement-fixation reactions indicating its relationship to the true diphtheria bacillus; similar studies made by Williams, Raiziss, and I2 with the typhoid colon group of bacilli, by Craig and Nickols3 with several strains of spirochetes, by Cooke4 with acid-fast bacilli, by Olmstead5 and Wollstein6 with meningococci, by Hooker7 with typhoid bacilli, and by Kitchens and Brown8 with streptococci indicate that the bacteriolytic amboceptors are highly specific and yield highly specific reactions with proper technic, and particularly with good and sensitive antigens, and under these conditions the complement-fixation test may be more delicate in differentiation than agglutination or other immunity reactions. As a practical procedure, however, the complement-fixation technic is too intricate and time-consuming. In this connection I desire to direct particular attention to the possibility of the sera of normal rabbits yielding positive complement-fixation reactions with various bacterial and lipoidal extracts as discussed on page J+19, in conducting complement-fixation tests with rabbit or dog sera the serum of each animal should first be tested with the antigen and immunization conducted only in case the animal's serum is found to react negatively; subsequent complement-fixing properties of the serum may then be ascribed to the presence of specific amboceptors. This was one of the first infections to be studied by means of the complement-fixation technic, but the results secured were not generally satisfactory until it was shown that the antigen must be polyvalent. Historic — In 1906 Muller and Oppenheim1 applied the complement-fixation test to the diagnosis of gonorrheal arthritis, using a culture of the gonococcus as antigen. To these observers, therefore, belongs the credit of being the first to record a complement-fixation test in a gonococcus infection. A little later in the same year Carl Bruch2 applied the reaction to three cases of gonorrhea, using the serum of immunized rabbits, and reported favorable results. In 1907 Meakins3 reported having secured positive reactions in three cases of gonorrheal arthritis, which was the first report in America published on this subject. Th. Vanned4 studied the specificity of the reaction with the serums of rabbits immunized with gonococcus protein and one of a meningococcus, and reported that the meningococcus immune serum did not show complement fixation with gonococcus antigen, and, vice versa, that gonococcus amboceptor was not bound by meningococcus antigen. Wollstein5 (1907), in a study of the biological relationship of the gonococcus and meningococcus, reported findings differing from those of Vannod. The former observer found that bacteriolytic amboceptors in the serums of rabbits immunized with these cultures were closely related and yielded fixation of complement with either antigen. Teaque and Torrey,6 in 1907, issued a very important communication showing that the differences in results of previous investigators were probably due in part to the use of single strains of the organisms in the preparation of antigens and immune serums. They emphasized the fact that the gonococcus belongs to a heterogeneous family, and that in attempting to formulate a diagnosis of gonorrheal infection by the complement-fixation method, the extracts of several different strains should be used. Naz Vannod and later Watabiki7 found that the gonococcus and meningococcus antibodies were quite specific for their homologous antigens in complement-fixation reactions. Particular attention was drawn to the gonococcus complement-fixation test by the work of Schwartz and McNeal.8 These investigators emphasized the necessity of using polyvalent antigens, and their encouraging reports have stimulated renewed interest in this subject. They found that if the infection is confined to the anterior urethra, a positive reaction is not obtained; that a strong reaction is not to be expected before the fourth week of the infection, and then only in acute cases with complications. They regard a positive reaction as indicating the presence or recent activity in the body of a focus of living gonococci, although a negative reaction does not exclude gonococcus infection. The test, therefore, has a more positive than a negative value. With Flexner's antimeningococcus serum positive reactions resulted with their gonococcus antigen; with serums from cases of cerebrospinal meningitis (meningococcic) the results were negative. In the succeeding years numerous investigators, including Swinburne, Gradwohl, O'Neil, Gardner and Clowes, Thomas and Ivy, Kolmer and Brown, have reported favorably upon the practical value of the gonococcus complement-fixation test, particularly as an aid in determining whether or not a patient is cured of the infection. Technic. — Since, because of the comparatively slight cellular involvement, the quantity of antibody produced in a localized gonococcus infection is probably small, the complement-fixation reactions are generally weak, and consequently require the closest technical attention, especially as regards the preparation of antigen and accurate adjustment of the hemolytic system. Hemolytic System. — As a rule, the antisheep hemolytic system is employed; the various ingredients may be used in one-half the quantity employed in the original Wassermann reaction, as given in the preceding chapter, with the technic ef the syphilis reaction, or one-tenth the quantity employed in the original Wassermann technic may be employed. I prefer to employ the larger amounts because the readings are usually easier to interpret. Fresh guinea-pig complement serum is diluted 1 : 20 and used in dose of 1 c.c. ( = 0.05 c.c. serum); sheep's corpuscles are made up in a 2}^ per cent, suspension and used in dose of 1 c.c.; antisheep amboceptor is titrated (see p. 399) and used in an amount equal to 2 hemolytic doses in conducting the antigen titration and in the test proper. Kolmer and Brown1 have compared the practical value of the antisheep and antihuman hemolytic systems in the examination of a number of serums. When the latter were used, some of the reactions were somewhat stronger and yielded slightly better results, showing the influence, probably, of natural antisheep amboceptor present in a large proportion of human serums. Antigen. — This constitutes the most important ingredient of the test. As Teague and Torrey and Schwartz and McNeal have emphasized, the antigen should be prepared of many different strains of gonococci. The difficulty of isolating this organism and the constant care required in subculturing and keeping a large number of strains alive render it practically impossible for many persons to prepare a gonococcus antigen. Therefore until simpler methods are devised, this antigen is best prepared in large central laboratories, where the cultures are handled and preserved by specially trained persons. The gonococci are well grown on a salt-free veal agar, neutral in reaction to phenolphthalein, and to which a few drops of sterile hydrocele fluid may be added. After culturing for from twenty-four to fortyeight hours the growths are washed off with distilled water, and the emulsion is heated in a water-bath for two hours at 56° C. It is then heated at 80° C. for one hour, filtered through paper pulp or centrifugalized, and passed through a Berkefeld filter which is reserved for this purpose alone and is neutral in reaction (see page 78) . A small amount of preservative, as, e. g., 0.1 c.c. of a 1 : 100 dilution of phenol to each cubic centimeter of antigen, may be added. The antigen is then well preserved in small amounts in ampules that are sealed and heated to 56° C. for half an hour on three successive days. Just before being used the antigen is made isotonic by adding 1 part of a 10 per cent, salt solution to 9 parts of antigen. I preserve the antigen in ampules containing 1 c.c., and after removing the antigen from the ampule to a large test-tube, add 1 c.c. of 10 per cent, salt solution, and dilute the whole 1 Jour. Infect. Dis., 1914, 15, 6. anticomplementary titration is made. In this method of preparing antigen the endotoxins constitute the main antigenic principle. Kolmer and. Brown, after an experimental study of the various antigens, found that a simple suspension of gonococci in salt solution yielded slightly better results. The various strains are grown for from forty-eight to seventy-two hours, and are then washed off with sterile saline solution, observing particular care not to include portions of the culture-medium. The suspension is then shaken to break up clumps, and heated to 56° C. for an hour. A small amount of preservative is now added, and the antigen stored in 1 c.c. ampules. Before using it is diluted 1 : 10 or 1 : 20, and titrated for the anticomplementary dose. Alcoholic extracts of gonococci have very little practical value, as alcohol is not satisfactory for extracting the antigenic principles of bacteria. Warden1 has reported good results with a new lipoid antigen. The anticomplementary dose of the antigen should be determined, and one-half or one-quarter this amount should be used in conducting the main test. An antigenic titration may also be conducted with an antigonococcus serum, to determine the antigenic value of the antigen, but in practice it is sufficient to use one-half the anticomplementary dose. This titration should be conducted and the antigen standardized before the main tests are adjusted. In the following table the results of an anticomplementary titration of a gonococcus antigen are given, the approximate dose having been ascertained in previous titrations (Fig. 120). If the antigen is new and the anticomplementary dose is entirely unknown, it may be necessary, in making this titration, to use a different dilution, with higher and lower doses. In conducting the main test the foregoing antigen could be used in dose of 0.2 or 0.4 c.c. of this dilution. The Test. — The serums should be fresh and clear, and heated to 56° C. for one-half hour. For each serum use four test-tubes (12 by 1 cm.), arranged in a row. Into each of the first three place the dose of antigen and increasing doses of serum — 0.05 c.c., 0.1 c.c., 0.2 c.c.; the fourth tube is the serum control, and into this is placed the maximum dose of serum (0.2 c.c.) but no antigen; 1 c.c. of complement diluted 1 : 20 is added to each tube. The following controls are included: 3. The serum control of each serum is conducted in the fourth tube of each series. At the completion of the test this tube should show complete hemolysis and thereby indicate that the serum was not anticomplementary. To each tube sufficient saline solution is added to bring the total volume up to about 2 c.c. The tubes are shaken and incubated for one hour at 37° C. in the thermostat or in a water-bath (not less than one hour), when 2 units of antisheep amboceptor and 1 c.c. of sheep corpuscle suspension are added to each tube except the corpuscle control. The tubes are gently shaken again and reincubated for an hour or longer, depending upon the hemolysis of the controls, after which the results are recorded. This secondary incubation may be omitted and the tubes placed in a refrigerator overnight and the results read the next morning. Under these conditions hemolysis occurs slowly, and, according to some workers in this field, the reaction becomes more delicate. Conducting the primary incubation by placing the tubes in a refrigerator at 8° C. for four hours or over night after the method of McNeal, followed by the addition of 2 units of hemolysin and 1 c.c. of corpuscle suspension to each tube and incubation in a water-bath at 38° C. for one-half to one hour, In reading the results the controls are first examined and should show complete hemolysis; the test is reported as negative if all tubes are hemolyzed, weakly positive if the largest dose only of serum (0.2 c.c.) shows inhibition of hemolysis, moderately positive if the 0.1 and 0.2 c.c. doses of serum show inhibition of hemolysis, and strongly positive if the 0.05, 0.1, and 0.2 c.c. doses of serum react positively. The test may be conducted with but one dose of serum, namely, 0.2 c.c. with the antigen and 0.2 or 0.3 c.c. in the serum control tube, after the manner of the original Wassermann reaction; in this case the readings are made after the usual +, + +, + + +, and + + + + method (see page 464) . the antigen is likely to be expensive. Otherwise the method is less FIG. 121. — GONOCOCCUS COMPLEMENT-FIXATION REACTION. Shows a + reaction with 0.05 c.c. serum; a + + with 0.1 c.c., and a 0.2 c.c., a strongly positive reaction. Complement serum is diluted 1 : 10 and used in dose of 0.1 c.c.; corpuscles are made up in a 10 per cent, suspension and used in dose of 0.1 c.c., the amboceptor is titrated with these amounts of complement and corpuscles, and used in dose equal to two units. Each day, before the main tests are undertaken, the anticomplementary dose of antigen is determined by placing increasing doses of diluted antigen with complement and salt solution in a series of tubes, incubating for an hour, adding two units of amboceptor and the corpuscles, followed by incubation for another hour. One-half or one-quarter of the anticomplementary dose is used in making the main test. The serums are inactivated and used in three ascending doses, — 0.005, 0.01, and 0.02 c.c., —equivalent respectively to 0.5, 1, and 2 c.c. of a 1 : 100 dilution (0.1 c.c. serum. 9.9 c.c. salt solution). The fourth tube of each series contains the maximum dose of serum without antigen, and is the serum control. The other controls, general technic, and readings of the reaction are the same as those previously described. SPECIFICITY OF THE GONOCOCCUS COMPLEMENT-FIXATION TEST Viewed from a practical standpoint, the reaction is highly specific. While complement-fixation experiments with antigens of gonococci and meningococci and their respective immune serums have demonstrated a biologic relationship between these microorganisms, yet practically with human serums an antigen of pure cultures of gonococci will fix complement only with the gonococcus antibody (amboceptor). In this technic a specific antigen is employed, and it is, therefore, a true application of the Bordet-Gengou reaction of complement fixation by specific antigen and specific antibody (amboceptor). Obtained under proper technical conditions, a positive reaction is invariably reliable, and indicates the presence of a focus of living gonococci. From our present knowledge of this reaction, it may be stated : 1. That the difficulty of isolating and preserving a sufficient number of cultures of true gonococci in order to prepare a satisfactory polyvalent antigen constitutes a weighty drawback to the practical use of the test. majority of cases, the degree of complement fixation is usually much less than that which occurs in the syphilis reaction, and accordingly the reactions are usually weaker and often indefinite. A negative reaction does not exclude gonorrhea. 3. The reaction is seldom positive during the first four to six weeks of an acute anterior or posterior urethritis, in the absence of complications. In acute exacerbations of a chronic urethritis the reaction is positive in about 80 per cent, of cases. In ordinary chronic urethritis with mild infection of the prostate gland the reaction is positive in from 30 to 40 per cent, of cases. In chronic urethritis complicated by marked involvement of the prostate gland and epididymitis the reactions are frequently positive, occurring in from 50 to over 80 per cent, of cases. The test possesses considerable value in determining the fitness of an applicant for a marriage license, and will, no doubt, be employed for this purpose quite extensively, as a positive reaction is now generally regarded as indicating the presence of a focus of active gonococcal infection. 4. During the course of an acute or a subacute urethritis the occurrence of an acute complication, such as prostatitis, epididymitis, etc., is likely to result in a positive fixation test. of cases. 6. A positive reaction may persist for several weeks after the patient is clinically cured. Torrey1 has shown experimentally that the antibody persists in the blood of rabbits artifically immunized for from ten days to six or seven weeks. Usually, under proper treatment, the reaction in ordinary cases of urethritis disappears in from two to three weeks; if, however, a positive reaction persists, a focus of infection is probably present, and the patient should be kept under further observation and the treatment persisted in. 7. In women the reaction is seldom positive until the infection has reached the cervical canal. In the case of little children, however, we have known positive reactions to occur in acute and chronic vulvovaginitis, indicating either that the disease is more severe in children, with more antibody formation, or that it may reach the cervical canal. The reaction is positive in about 60 per cent, of cases of pyosalpingitis, and the test may prove of value in making the differentiation of inflammatory lesions from certain cystic and neoplastic conditions, and in establishing the gonorrheal basis of many of these infections. 1 Jour. Med. Research, 1910, i, 95. 8. Cases of gonorrheal arthritis yield from 80 to 100 per cent, of positive reactions, and the 'complement-fixation test has considerable value in establishing the diagnosis of these infections. 9. The administration of gonococcus vaccine and antigonococcus serum is likely to be followed by positive reactions. Just how long the antibodies may persist in the blood after a clinical cure has been effected it is difficult to state; at least from six to twelve weeks' time should be given for them to disappear. 10. In medicolegal cases the courts may not accept the usual evidence offered by a bacteriologic diagnosis based upon stained smears of a secretion, and cultures are frequently differentiated from other Gramnegative diplococci only with difficulty. Conducted with the proper technic, the gonococcus fixation test is highly specific and much less difficult to perform. 11. Finally, it must be emphasized that the reaction has a far more positive than negative value. The reaction is highly specific, but there is a limit to its delicacy, so that a negative reaction in urethritis does not exclude the possibility of gonococcal infection. The complement-fixation test is used extensively by veterinarians in making a laboratory diagnosis of glanders. The test has been found very reliable, and is usually more delicate than the agglutination test and the Strauss guinea-pig test. It has also been used successfully in the diagnosis of human glanders. Preparation and Standardization of Antigen. — The antigen should be polyvalent, and composed of at least several different strains. Cultures of Bacillus mallei are grown on slants of glycerin agar (1.6 per cent, acid) for from forty-eight to seventy-two hours. The growths are then removed, and sufficient distilled water added to give a milky suspension. This suspension is sterilized by heating the tubes to 60° C. for two hours. They are then shaken mechanically with glass beads for a few hours on two successive days. Enough sodium chlorid is added to make the solution isotonic, and the whole is preserved with 0.5 per cent, phenol and stored in a dark, cold place, where it will keep for many months. Antigen may also be prepared in the same manner as gonococcus antigen as described on page 505. A simpler antigen is prepared by growing the bacillus in glycerin bouillon for seventy-two hours, sterilizing by heating to 60° C. for two hours, and preserving with the addition of 0.5 per cent, of phenol. The anticomplementary dose is then determined by tit-ration. The antigen is diluted 1 : 20 by mixing 1 c.c. with 19 c.c. of normal saline solution. To a series of seven test-tubes add increasing amounts of diluted antigen as follows: 0.1, 0.2, 0.4, 0.6, 0.8, 1, and 2 c.c. Add 1 c.c. of complement serum (1 : 20) to each tube,, and sufficient salt solution to bring the total volume in each up to 3 c.c. Incubate for an hour at 37° C., and add 2 units of antisheep amboceptor titrated just previous to making the test (see p. 399) and 1 c.c. of sheep corpuscle suspension. Reincubate for an hour or an hour and a half. At the end of this time that tube showing beginning inhibition of hemolysis contains the anticomplementary unit, and one-fourth to one-half this amount is used in making the main test. An antigenic titration may also be made, but this is not absolutely necessary. To a series of tubes containing 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 c.c. of diluted antigen add 0.1 c.c. of fresh heated glanders serum (known to yield a positive reaction) and 1 c.c. of complement serum (1 : 20) and sufficient salt solution. Incubate for one hour and add 2 units of hemolytic amboceptor and corpuscles. After a second incubation of from one to two hours that tube shoiving just complete inhibition of hemolysis contains the antigenic unit, and double this amount may be used in performing the main test, providing that it is still one-half or, better, but one-quarter the anticomplementary unit. A hemolytic system control is included in both titrations, and in the antigenic titration an additional control on the serum, to determine whether it is free from anticomplementary action. titrations must be repeated with the antigen diluted 1 : 50 or 1 : 100. The Test. — The external jugular vein of the horse is punctured with a sterile needle, and from 5 to 10 c.c. of blood is collected in a centrifuge tube or other glass container, which preferably should be sterile. The clear serum is heated to 55° C. for one-half hour just before the tests are conducted. Into a series of four small test-tubes place the following doses of serum: 0.05, 0.1, 0.2, and 0.2 c.c. To the first three tubes add the proper dose of antigen; to all tubes add 1 c.c. of complement (1 : 20) and sufficient salt solution to bring the total volume up to 3 c.c. and 3 c.c. of saline solution. This tube should be plugged with cotton. All tubes are gently shaken and incubated for an hour in a waterbath at 38° C. or in a refrigerator at 8° to 12° C. for four to six hours or over night, after which 2 units of hemolytic amboceptor and 1 c.c. of corpuscle suspension are added to all except the corpuscle control. The tubes are gently shaken and reincubated in a water-bath for an hour or two, depending upon the hemolysis of the controls. Primary incubation in the refrigerator is especially recommended. The controls are first inspected. They should all show complete hemolysis, except the first three tubes of the positive serum series and the corpuscle control. Inhibition of hemolysis in the first three tubes of the series containing the unknown serum indicates a strong positive reaction. Complete hemolysis in all tubes indicates a negative reaction. Partial hemolysis in the first three tubes indicates a partially positive reaction. If the serum control or antigen control tubes should show inhibition of hemolysis, these were probably anticomplementary and the test should be repeated. COMPLEMENT-FIXATION TEST IN CONTAGIOUS ABORTION It is now generally conceded among veterinarians that the Bacillus abortus of Bang is the specific cause of contagious abortion of cows. Evidence is gradually accumulating to show that an organism belonging to the paratyphoid group is frequently the cause of a similar condition among mares (Kilbourne and Smith,1 Liguierer,2 Liguierer andZabala; Good;3 VanNeelsbergen;4 de Jong;5 Meyer and Boerner)6. Meyer and Boerner, who have studied this bacillus with particular care, classify it with the paratyphoid-enteritidis group (Bacillus aborti equi). Veterinarians are generally agreed that in contagious abortion of cows the complement-fixation test is highly specific, and is frequently of considerable value in establishing a diagnosis (Meyer and Hardenburgh and others). Meyer and Boerner have found fixation of complement to occur in contagious abortion of mares with an antigen of Bacillus abortus equi, and recommend the test as diagnostic aid in this infection. Preparation and Standardization of Antigens. — The antigen of Bacillus abortus (Bang) for use in the complement-fixation test in contagious abortion of cows is prepared by cultivating a number of strains .of the bacillus, which have been trained to grow aerobically, upon slants of glycerin agar for seventy-two hours. The growths are then washed off with sufficient normal saline solution containing 2 per cent, phenol to yield a cloudy emulsion. Shake briskly in order to break up the clumps of bacilli, and filter through paper. Place in a refrigerator for several days to complete the sterilization, and titrate the anticomplementary dose each time before the main test is conducted. The antigen may also be prepared by cultivating a number of strains in glycerin-serum bouillon for five or six weeks. Centrifuge thoroughly and wash the bacilli once or twice with normal saline solution, to remove all traces of serum. Dilute the washed bacilli with sufficient normal saline solution to give an emulsion equal in density to a twenty-fourhour bouillon culture of Bacillus coli, and add 0.4 per cent, of phenol as a preservative. The antigen of Bacillus abortus equi for making the complementfixation diagnosis of contagious abortion of mares is prepared of eighteen- to twenty-hour-old glycerin bouillon cultures, with an addition of 0.5 per cent, of phenol. These antigens are less anticomplementary than shake extracts, and keep their titer unaltered for many weeks (Meyer and Boerner). They may also be used for making the macroscopic agglutination test. These antigens may also be prepared after the method used in the preparation of gonococcus antigen (page 506). The anticomplementary dose is determined each time, and one-half this amount is used in performing the main test. The technic is the same as that employed in the titration of glanders antigen. The tests and controls are conducted with descending doses of fresh inactivated serum (0.05, 0.1, and 0.2 c.c.), in exactly the same manner as the glanders reaction is performed. COMPLEMENT FIXATION IN DOURINE Dourine, or horse syphilis, is a specific infectious disease of the horse and ass, transmitted from animal to animal by the act of copulation, and caused by the Trypanosoma equiperdum. It is characterized by an irregular incubation period, the localization of the early symptoms to the .genital organs, and, finally, by complete paralysis of the posterior extremities, a fatal termination ensuing in from six months to two years. clinical diagnosis difficult. Complement-fixation methods of diagnosis have been tried by Pavlosvici, Winkler and Wyschelersky, Moller, Watson, Brown, and in a large series of cases with good results by Moller, Eichhorn, and Buck.1 These last-named investigators examined 8657 specimens of blood from horses in Montana and North and South Dakota, and of these, 1076 yielded positive reactions. In most of these experiments the results were corroborated by clinical and pathologic findings, and the investigators conclude that the complement-fixation test is of great value, especially in countries where only one of these protozoan diseases exists. Preparation and Standardization of Antigen. — This is the most difficult part of the technic, because the trypanosome is not readily grown on artificial culture-media. Watery, alcoholic, and acetone extracts of various organs of horses dead of the disease do not yield satisfactory antigens. Since the reaction is a group reaction, and dourine is the only trypanosome infection in this country, Moller, Eichhorn, and Buck selected the surra organism for the preparation of antigen. After infecting a dog and at the height of infection withdrawing 200 c.c. of blood into potassium citrate and hemolyzing with 0.5 gram of saponin, the trypanosomes were secured after thorough centrifugalization and washed three times. After the last washing the trypanosomes were emulsified in 50 c.c. of salt solution and preserved with phenol. This antigen yielded highly satisfactory results, but the difficulty of preparing it, and the small quantity secured, made it necessary that another method be used. An extract of the spleen of a rat just dead of surra was found to yield a satisfactory antigen. The extract does not keep well, and must be prepared freshly every few days and carefully standardized. Gray or white rats are infected with surra by injecting 0.2 c.c. of blood from a rabbit with this disease. If a large number of tests are to be made, the rats should be so infected that one or two are available each day for the preparation of the antigen. The spleen from a rat with a small amount of salt solution added is ground in a mortar until a pulpy mass results. More of the salt solution is added from time to time, and the suspension thus obtained is filtered twice through a double layer of gauze and diluted with salt solution to 40 c.c. The anticomplementary and antigenic doses are then determined, and the extract used in double the antigenic unit, providing that this amount is not more than half the anticomplementary dose. If a positive serum from an infected horse is not available, the anticomplementary dose may be determined and half this amount used in conducting the main test. Anticomplementary Titration. — Into a series of six test-tubes place increasing amounts of antigen — 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 c.c.; add 1 c.c. of complement (1 : 20) and sufficient salt solution to bring the total volume in each tube up to 2 c.c. Incubate for one hour in a water-bath at 38° C. or, preferably, in a refrigerator ot 8° C. for six hours or over night. Add 2 units of antisheep amboceptor (determined by preliminary titration) and 1 c.c. of 2.5 per cent, sheep's corpuscles. Incubate for one hour in a water-bath, after which the reading is made. The Test. — The serum is inactivated and used in dose of 0.15 c.c., since it has been found that fixation in this quantity is obtained only with serums of horses affected with dourine. In some instances the serum of horses has reacted in doses as small as 0.02 c.c., and the reac.tion may be conducted with increasing doses of serum — 0.05, 0.1, and 0.15 c.c. — in exactly the same manner as when the glanders reaction is performed. The same Controls are included. COMPLEMENT-FIXATION TEST IN TYPHOID FEVER This was one of the original diseases in which Bordet and Gengou first demonstrated the occurrence of complement fixation. Widal and Lesourd attempted to make practical application of this method in the diagnosis of the disease, but their results were indifferent, and since then numerous writers have expressed various opinions as to the value of the test. Garbat has secured uniform and reliable reactions with a polyvalent antigen, and emphasizes the importance of this factor. The antigen is prepared of numerous strains of typhoid bacilli — the more the better. Cultures are grown on slants of agar for forty-eight hours, washed off with small quantities of sterile distilled water, heated to 60° C. for two hours, shaken mechanically for twenty-four hours, and either filtered through a sterile Berkefeld filter or thoroughly centrifugalized. The filtrate is preserved with 0.5 per cent, phenol and used as antigen. I have secured good results by removing the growths with small amounts of normal salt solution, and placing them in a shaking flask, and shaking for an hour to break up the clumps. After heating to 60° C. for an hour, 1 per cent, glycerin and 0.5 phenol are added as preservatives, and the mixture stored away in ampules containing 1 c.c. each. The emulsion should be slightly milky in appearance. The antigen is diluted 1 : 10 or 1 : 20, and the anticomplementary dose determined by titration before the main tests are conducted. The technic of the reaction is exactly similar to the gonococcus fixation test. The ease with which the Widal reaction is performed renders it the method of choice. Nevertheless the complement-fixation test is quite delicate, and will frequently aid, where the agglutination test is negative or absent and in making the differential diagnosis from paratyphoid fever. The strongest reactions are secured late in the disease. COMPLEMENT-FIXATION TEST IN TUBERCULOSIS It was the original studies in complement fixation in tuberculosis made by Wassermann and Bruch that later induced these workers, in cooperation with Neisser, to apply the method to the diagnosis of syphilis. The first application of complement-fixation in tuberculosis was made by Widal and LeSourd1 in 1901. They obtained deviation of complement in certain cases of tuberculosis, using as antigen homogeneous emulsions of tubercle bacilli of the Arloing-Courmont strain. In 1903 Bordet and Gengou2 demonstrated the presence of antibody capable of uniting with tubercle bacilli and fixing complement in the sera of tuberculous animals. Wassermann and Bruck3 in 1906 demonstrated the presence of an antibody to tuberculin in patients treated with tuberculin, but they examined only 13 cases of pulmonary tuberculosis. Caulfield4 in 1911 examined 104 cases of pulmonary tubercu- losis with bacillary emulsion as antigen and obtained 33 per cent. Turban I cases, 70 per cent. Turban II, and 62 per cent. Turban III positive results. Laird1 (1912) out of 84 tests in 34 cases obtained 24 positives in 4 cases, using watery emulsion of tubercle bacilli (which ,he does not describe); his results were inconclusive. Hammer,2 using O. T. and extracted tuberculous nodules, obtained 97 per cent, positive results in 46 tuberculous cases. Calmette and Massol,3 using preparations made from tubercle bacilli by extracting with water and peptone, obtained in 134 cases 92.5 per cent, fixation. Fraser4 (1913), testing a large variety of antigens, found that living bacilli gave no fixation in 96.6 per cent, of normal individuals, but gave positive reactions in 42.3 per cent, of tuberculous individuals. She states that the most reliable antigen is prepared from living human bacilli, and that diagnostically the complement-fixation test with living bacilli is of more value from the standpoint of positive results than any other reaction discovered to date. She believes the absence of antibodies accounts for the low percentage of results obtained. Dudgeon, Meek, and Weir5 also tested a large number of antigens, and in 102 untreated cases obtained 86 positive results, while all cases which had been treated with tuberculin gave positive results. Products of the bacilli themselves were found to be the most satisfactory as antigen. With an alcoholic antigen6 prepared from tubercle bacilli they obtained from a total of 234 cases, 209 (89.3 per cent.) positives, 194 of these on first examination, 11 (of the 15 negative) on second examination, and 4 more on third examination. Besredka7 (1913) prepared an antigen by growing tubercle bacilli on egg broth, heating it, and filtering. W'ith this antigen Bronfenbrenner8 (1914) obtained a very high percentage of positive results, 93.8 per cent, in active cases, and 55.5 per cent, in convalescents, while suspected cases gave 75 per cent, and syphilitic sera 24 per cent, positive reactions. Inman9 and Kuss, Leredde and Rubenstein10 found this antigen non-specific. Mclntosh, Fildes, and Radcliffe11 (1914) also justly criticized Besredka's antigen, and concluded, after testing a large number of antigens, that the living bacillary emulsion was best, yielding 76.7 per cent, positive results in 43 definite cases of phthisis, 80.7 per cent, in surgical tuberculosis, and 37.5 per cent, in glandular tuberculosis. Of 87 normal individuals, only 3 gave positive reactions (2 of these were lepers and 1 had Addison's disease.) Negative reactions were obtained in 18 syphilitic patients. They look upon a positive reaction as indicative of active tuberculosis. Stimson1 (1915), who gives a fairly exhaustive table of the recent literature, reports a small number of cases in which a variety of antigens were used, but his results were inconclusive. Craig2 (1915) reports the results of examination of 166 cases of pulmonary tuberculosis in which he employed as antigen an alcoholic extract of several strains of human tubercle bacilli which had been grown on a liquid medium of alkaline broth containing egg; 96.2 per cent, positive results were obtained in active cases and 66.1 per cent, positive in inactive cases. One hundred and fifty cases of syphilis gave only 2 positive reactions, and these, on further examination, revealed lesions in the lungs. One hundred other diseases examined all gave negative results. In a later report Craig, using his same antigen of a filtrate of an alcoholic extract of several strains of human tubercle bacillus plus the culture-medium in which the bacilli had been grown, has reported further favorable results in complement-fixation in tuberculosis. Miller and Zinsser3 have described a simple antigen prepared by grinding living or dead tubercle bacilli with dry table salt, and then adding distilled water up to isotonicity. With this antigen they have reported excellent results; Miller4 found the reaction practically always positive in active tuberculosis with negative reactions in non-tuberculous syphilitic and normal persons. In my own studies in co-operation with Montgomery, prepared after Miller's method, yielded positive reactions only with the sera of tuberculous persons, but the percentage of positive reactions was much less than reported. Corber,5 employing an autolysate of tubercle bacilli as antigen, found 30 per cent, positive reactions with clinically definite cases of tuberculosis both active and inactive. Active cases gave a higher percentage of positive results than inactive cases. Eichhorn and Blumberg,6 using Besredka's antigen and the sera of tuberculous persons and the lower animals, found the complement-fixation test less reliable than the subcutaneous tuberculin test in the diagnosis of tuberculosis in cattle and not practical for general diagnostic purposes. Lucke1 found that the wax of tubercle bacilli possessed no antigenic properties; Wood, Bushnell, and Maddux2 have observed a large percentage of apparently specific reactions with the partial antigens of Deyke and Much.3 Preparation and Standardization of Antigen. — It is apparent, therefore, that the question of proper antigen is of paramount importance in complement fixation in tuberculosis. It would appear that Besredka's and Craig's antigens and suspensions of living tubercle bacilli are of definite value. The main objections to the bacillary emulsion are the small difference between the antigenic and anticomplementary units, the turbidity, and fairly high percentage of non-specific reactions. Eichhorn and Blumberg have given the following directions for the preparation of a modified Besredka antigen: Twenty c.c. each of the white and the yolk of an egg were thoroughly beaten in an automatic egg-beater, and to the whipped material a solution of Liebig's meat extract (3 : 1000) in distilled water is gradually added while the mixture was continuously beaten. A sufficient meatextract infusion is used to make up the whole to 1000 c.c. The emulsion is strained through cotton and heated to the boiling-point, then strained again, and after the addition of 0.5 per cent, of sodium chlorid is carefully neutralized, heated again and strained, and neutralized if necessary. To the neutral medium sufficient normal sodium hydroxid - solution is added to make the medium of 0.2 alkalinity. This medium, to which neither peptone nor glycerin was added, was then autoclaved at 115° C. for twenty minutes, and after cooling is kept at 37° C. for forty-eight hours for observation as to sterility. Whatever antigen is employed it must be carefully titrated for the anticomplementary unit each time before the main tests are conducted. I conduct these titrations in the same manner as described under the gonococcus complement-fixation test and use one-third the anticomplementary unit as the dose for the main tests. The Test. — These may be conducted with a 0.2 c.c. dose of serum or with three graded doses, as 0.05, 0.1, and 0.2 c.c., as described in the gonococcus complement-fixation test. I have generally employed the latter with a primary incubation of six hours or over night in the refrigerator at 8° C. or one hour in the water-bath at 38° C. Practical Value of the Complement-fixation Test in Tuberculosis. — It is still too early to express an accurate opinion of the practical value of this test; an analysis of numerous reports and my own studies apparently warrants the following statements: 1. A definitely positive reaction taken in conjunction with other findings makes the diagnosis of tuberculosis certain and may be of distinct aid in the diagnosis of early tuberculosis. 2. From the standpoint of differential diagnosis the test is of value when positive as indicating tuberculosis against other diseases of the lungs, as carcinoma, syphilis, abscess, empyema, etc. 3. As the reaction is likely to be positive only in active cases, the complement-fixation test is superior to other biologic tests for active tuberculosis, as, for example, the skin test, which is likely to be positive in persons with quiescent lesions. the presence of active tuberculosis. 5. The strength of a positive reaction appears to bear some relation to the severity of the disease, and reactions becoming gradually weaker until negative have been frequently noted with clinical improvement and "cure." Investigations on complement fixation with the bacillus of pertussis has given varied results, perhaps due in part to a variation in the cultures employed and the methods used to prepare the antigens. Bordet and Gengou1 used suspensions in salt -solution of growths on solid media. Arnheim2 found negative results with antigens of both the Bordet-Gengou bacillus of pertussis and the influenza bacillus. Wollstein3 used three forms of antigen: suspensions of the bacilli in salt solution; extracts of bacilli made by suspending the growths of three blood-agar slants in 5 c.c. of salt solution and shaking for twentyfour hours in thermostat; and extracts of tissue obtained from patients dying from pertussis. Friedlander and Wagner4 used live bacteria and fresh serum, and considered this innovation of great importance. The different hemolytic systems employed may also have had some bearing on the failure to obtain identical results. cases of pertussis. They used 0.1 c.c. to 0.3 c.c. of the human serum heated to 56° C., and 0.05 c.c. to 0.01 c.c. of fresh guinea-pig serum as complement. The amboceptor was the serum of rabbits previously injected with sheep corpuscles. The antigen was an emulsion of the bacillus of pertussis in salt solution, the growth being twenty-four hours old. Arnheim1 obtained complement fixation in 6 of 12 cases of pertussis. Wollstein examined the serum from 9 patients with pertussis and in no instance did she obtain complement fixation, using the three forms of antigen just mentioned in all cases. The quantities of complement and amboceptor were about the same as those used by Bordet and Gengou. the specific pertussis character of the infection by complement fixation. In 1911 Bordet and Gengou3 reported certain atypical cases diagnosed as pertussis by means of complement fixation. A little later Bordet4 concluded that the power to fix complement is not found early, and does not become marked until near the end of the disease. St. Bacher and Menschikoff5 report 27 cases of pertussis in all stages in which attempts were made to obtain complement fixation, without success in a single case. Only after vaccines of pure cultures of the Bacillus pertussis were given did fixation occur. Their antigen was an emulsion of the bacillus of pertussis in salt solution, while 0.4 c.c. of a 1 : 10 dilution of guinea-pig serum served as complement, and 0.5 c.c. of a 1 : 150 dilution of serum of a rabbit previously injected with sheep corpuscles served as amboceptor. Delcourt6 obtained complement fixation in 6 cases of pertussis. Poleff7 gives a resume of the results of five investigators. In 5 cases only was there complement fixation and in 31 cases no fixation was obtained. He himself reports 10 cases in which he did not obtain fixation. Recently Anna Wessels Williams1 came to the conclusion that the test with serum of human beings is not as clear cut as it seems to be with serum of animals which have been injected with the bacillus of pertussis. Renaux,2 using the Bacillus pertussis for antigen, examined 73 sera for complement fixation, 32 cases of which were known cases of pertussis. Of the cases of pertussis, he obtained complement fixation in 23. Of the 9 negative cases, the serum had been obtained early during the disease, and 3 of these gave positive complement fixation when the attack had lasted about four weeks. No further examination was made on the remaining 6 cases. His results seem to show that fixation appears about three or four weeks after the appearance of the whoop. In 18 cases of pertussis Friedlander and Wagner3 obtained complement fixation in each case. They used fresh serum of pertussis patients and living bacteria. The Noguchi hemolytic system was used throughout their work on account of the small quantity of serum necessary. They claim that the diagnosis of pertussis can be made with certainty in the catarrhal stage by means of complement fixation. In a more recent article Freidlander4 reports further results. He obtained fixation in 13 of 14 cases in the catarrhal stage before the characteristic whoop had appeared. In one case there was fixation three weeks before the first whoop. Winholt5 has reported positive reactions in pertussis with polyvalent antigens prepared by cultivating the bacilli on potatoglycerin blood-agar, suspending in normal salt solution, and heating to 56° C. for thirty minutes. Olmstead and Povitsky6 have been able to differentiate between Bacillis pertussis and B. influenza by means of the complement-fixation tests employing rabbit immune sera. Preparation and Standardization of the Antigen. — Antigens may be prepared in the same manner as gonococcus antigen (page 505) and should be polyvalent. The antigen should always be titrated for the anticomplementary unit as described in the gonococcus complementfixation test, and used in a dose corresponding to one-third the anticomplementary unit. test. The serum should be inactivated, as active serum is likely to yield non-specific reactions. The primary incubation for complement fixation should be one hour at 38° C. in the water-bath or six hours in the refrigerator at 8° C. Practical Value of the Test. — Positive reactions are not usually obtained until the paroxysmal stage is reached, when about 50 per cent, of sera react positively (Park). For this reason the complementfixation test possesses little value in early diagnosis. It is at times of value in the diagnosis of atypical cases. IMMUNE SERUMS The technic of complement fixation has also been employed as one means in effecting the standardization of antimeningococci and antigonococcic serums. Since, however, the amount of complement-fixing amboceptors in a serum is no index to its therapeutic and prophylactic value, a measure of this one factor is not a reliable standard. The technic consists in preparing the antigen and in determining its anticomplementary dose. Whatever this is, one-half to one-quarter this amount is added to increasing quantities of heated immune serum, ranging from 0.001 to 0.1 c.c. Complement and saline solution are added, and after incubating one hour at 37° C., the amount of complement fixation is determined by adding hemolytic amboceptors and corpuscles. While this titration is one measure of the reaction of the animal used in the immunization, better evidence of the therapeutic value of the serum is obtained by determining the content in bacteriotropins, by testing the serum with the antigen in susceptible animals, or by a combination of all methods. coides.1 Weinberg,2 Jiani,3 Israel,4 and Henius5 report favorable and specific reactions in echinococcus disease with aqueous or alcoholic extracts of cyst fluid, or both. Kurt Meyer6 found these reactions nonspecific, in that the serum of a person infested with echinococcus showed complement-absorption with antigens of Tsenia solium and T. saginata, and vice versa. Branes7 found that alcoholic extracts of echinococcus cyst fluid showed complement-absorption with the syphilis antibody as well as with that of echinococcus disease, and this observation has been generally confirmed. Thomsen and Magnusson8 in a study of 12 cases of echinococcus disease found that the sera of 10 reacted positively; the sera of 55 control cases (32 of which reacted positively to the Wassermann reaction) all were negative except one. These authors also report favorabty on the specificity of the reaction: the sera of 10 persons infected with Tsenia saginata, of 2 with T. solium, and of 1 with Bothriocephalus latus, all were negative with echinococcus antigen. In so far as echinococcus disease of the liver is concerned, a review of the literature shows a general consensus of opinion that antibodies are present in the sera of the majority of diseased persons and animals and that these may be detected by means of a complement-fixation test. There is, however, a division of opinion in regard to the specificity of the reaction and its practical value in diagnosis. Much less work has been reported on complement fixation with sera of persons infested with such parasites as Tsenia saginata, Ascaris lumbricoides, etc. Miss Trist and I9 have observed positive reactions with sera of dogs infested with various parasites and salt solution extracts of the respective worms. The method is worthy of trial in the diagnosis of infestments of persons with the various intestinal parasites. 0.5 per cent, phenol, and kept constantly at a low temperature. It is highly important not to use the antigen in an anticomplementary dose, hence it should be titrated before each test is made. Anticomplementary Titration. — Dilute the fluid 1 : 10 with normal saline solution, and into a series of eight small test-tubes place increasing amounts as follows: 0.1, 0.2, 0.4, 0.6, 0.8, 1, 2, and 3 c.c. Add 1 c.c. of complement (1 : 20) and sufficient saline solution to bring the total volume in each tube up to 4 c.c. Shake gently, incubate for one hour, and then add 2 units of antisheep amboceptor (previously titrated) and corpuscles. Reincubate for one to two hours; the tube showing beginning inhibition of hemolysis contains the anticomplementary dose, and in performing the main test, one-half to one-quarter this amount may be used. dose, the titration should be repeated with undiluted fluid. Alcoholic extracts of daughter cysts, the hydatid wall, or the fluid have been found to give positive reactions in syphilis (Israel, Brauer, Henins), and are, therefore, unsatisfactory. trated with cyst fluid and titrated. The Test. — The patient's serum should be fresh, and should be heated to 55° C. for half an hour. Into a series of five test-tubes place 0.025, 0.05, 0.1, 0.2, and 0.2 c.c. of serum. To each of the first four tubes add one-half the anticomplementary dose of antigen; to all the tubes add 1 c.c. of complement (1 : 20) and sufficient saline solution to bring the total volume up to 3 c.c. The fifth tube is the serum control; an antigen, hemolytic system, and corpuscle control should be included, as is usual in complementfixation tests. A normal serum may be included, and, if possible, a known positive serum. After incubating for an hour at 37° C., add 2 units of hemorytic amboceptor and 1 c.c. of the corpuscle suspension to each tube. Reincubate for an hour or longer, depending upon the hemolysis of the controls. Marked or complete inhibition of hemolysis in the fourth tube (0.2 c.c. patient's serum), with lesser degrees of inhibition in the other tubes of the series, indicates a positive reaction. Larger doses of patient's serum should not be used on account of the probability of nonspecific complement fixation. tests hitherto considered the antigens were known, and the suspected antibodies sought for in the blood-serum or other body-fluid. In making the reactions it was necessary to bring the serum to be tested into contact with the antigen specific for the suspected antibody, in the presence of complement, and at a suitable temperature. At the end of an hour the mixture was tested for free complement by adding hemolytic amboceptor and red blood-corpuscles. This order may be reversed, and with a known antibody the suspected antigen may be detected. The antigen to be detected, as in a solution of blood or bacterial extract, is brought into contact with its specific antibody in the presence of complement. At the end of an hour, at a suitable temperature, the mixture is tested as previously for free complement, by adding corpuscles and hemolytic amboceptors. Under proper conditions complement fixation would indicate a specific reaction between the antibody and its antigen, and thus serve to identify the latter. precipitin reaction is used : 1. In the differentiation of blood-stains a solution of the stain constitutes the unknown antigen. By furnishing a known antiserum the antigen is detected, i. e., the animal from which the blood was derived is ascertained. 2. In the recognition and differentiation of meats. 3. In the detection of bacterial antigens in the blood-serum of patients, or with highly immune serums an unknown bacterial antigen may be identified and the test employed as a means of differentiation among bacterial species. of milks, seminal stains, and other albuminous substances. As compared with precipitin reactions, the complement-fixation test is probably more delicate and reliable and easier of interpretation. The technic of the latter method is, however, more complicated, and the liability to error is greater unless the principles of complement fixation in general are thoroughly understood and the importance of quantitative factors is appreciated. 1. Complement Fixation for the Identification of Blood-stains. — The application of the technic of complement fixation to the determination of specific protein antigen, such as human or animal blood, was demon- strated by Gengou in 1902. The principles worked out by him were extensively studied and practically applied by Neisser and Sachs in the forensic differentiation of animal proteins. Hemolytic System. — Complement is furnished by the fresh serum of a guinea-pig diluted 1 : 20 and used in dose of 1 c.c. ( = 0.05 c.c. serum); washed sheep's corpuscles are made up in a 2.5 per cent, suspension and used in dose of 1 c.c.; antisheep amboceptor should be highly potent, and is titrated after the method previously given (p. 399). In the following titrations, and in conducting the main test the hemolytic amboceptor is used in an amount equal to 2 units. Specific Antiserum. — This is obtained from a rabbit immunized with the protein for which the test is to be made, namely, human or animal blood-serum. In forensic tests it may be necessary to prepare a number of these antiserums with the serums of man and the ordinary domestic animals. The technic of immunization is the same as that employed for the preparation of precipitins (p. 70). An antiserum for forensic tests must be sufficiently potent to fix complement with 0.0001 c.c. of its antigen. This is determined by a process of titration. If, for example, an antihuman serum is to be titrated, the method of procedure is as follows : Secure 0.1 c.c. of fresh human serum and dilute 1 : 1000 by adding 99.9 c.c. of normal saline solution. Of this dilution, 0.1 c.c. is equivalent to the standard dose of 0.0001 c.c. of undiluted serum. The serum may be used 1 : 500. The antiserum is heated to 55° C. for half an hour and diluted 1 : 10 (1 c.c. immune serum plus 9 c.c. of saline solution). Decreasing doses of immune serum are mixed with a constant dose of antigen and complement. At the same time the anticomplementary titration of the immune serum is made by substituting salt solution for antigen. The doses to employ and the results of an actual titration are shown in Table 19: Tube 16 is the hemolytic system control, and shows complete hemolysis; tube 15 is the antigen control, and shows complete hemolysis, as the quantity of serum is too small to exert an anticomplementary influence; tubes 11 to 14 are the tests for anticomplementary action of the antiserum. In the present instance the serum was several months old and the maximum dose of 1 c.c. ( = 0.1 c.c. undiluted serum) was very slightly anticomplementary. A fresh serum is practically never anticomplementary in this dosage, but these tubes should, nevertheless, be included in each titration. Tubes 1 to 10 include the antigenic titration, and show that the antiserum is perfectly antigenic in dose of Each antiserum is tested in a similar manner. In forensic blood tests an antihuman serum is, of course, employed first; if this is negative and it is desirable to determine the source of the blood, other antiserums, so that the ox, horse, dog, etc., are prepared, titrated, and tested with a solution of the blood-stain. The Blood-stain. — It is first necessary to ascertain that the stain is a blood-stain; this is done by performing the hemin crystal or an oxydase test (p. 326)u The stain is then extracted in normal saline solution, as described on p. 327. A 1 : 1000 dilution is made approximately by so diluting the extract that it just gives a slight opalescence when boiled with a few drops of acetic acid, and a slight foam persists after shaking. The Test. — Into a series of six small test-tubes place increasing doses of extract of the blood-stain (antigen), as follows: 0.1 c.c., 0.2 c.c., 0.4 c.c., 0.6 c.c., 0.8 c.c., 1 c.c.; add double the titrated dose of antiserum and 1 c.c. of complement (1 : 20), with sufficient salt solution to bring the total volume in each tube up to 3 c.c. The tube should be plugged with cotton. Shake all the tubes gently and incubate for an hour at 37° C. in a water-bath or, preferably, six hours or overnight in a refrigerator at 8° C. Add 2 units of hemolytic amboceptor and 1 c.c. of corpuscle suspension to each tube except the corpuscle control. Shake gently and reincubate for from one to two hours in a water-bath, depending upon the degree of hemolysis present in the controls. The readings are made at once, and again after the tubes have been allowed to settle in the refrigerator overnight. Inhibition of hemolysis with the smallest dose of blood extract — 0.1 c.c. ( = approximately 0.0001 c.c. of blood) — indicates that the blood extract is most certainly the antigen for the antiserum employed. Even with the maximum dose of extract — 1 c.c. ( = approximately 0.001 c.c. of blood) — inhibition of hemolysis serves to show the nature of the blood. With an antihuman serum, for instance, a similar specific reaction would be possible only with the bloods of the higher apes. In making blood tests for medicolegal purposes the antiserum should not only be standardized with a definite dilution of human serum, but the whole test should first be conducted with a known dried human blood-stain, and it must be borne in mind that extreme accuracy in all manipulations is essential. directed. I prefer this complement-fixation test to the precipitin reaction in the differentiation of proteins, as the readings are sharper and more definite. This test is fully as reliable as the precipitin test, and there is less danger of group reaction. The technic is essentially similar to that used in the foregoing test. Antiserums are prepared by immunizing rabbits with the serums of various animals, as the ox, horse, dog, cat, or any other animal the presence of whose flesh is to be identified in sausages, bologna, etc. It is not necessary to immunize with an extract of these meats themselves, as the blood or blood-serums will suffice. The technic of immunization is the same as that employed in the preparation of precipitin serums. Each antiserum is titrated with its antigen, as previously described, and is used in double the titrated dose in conducting the main test. described. 3. Complement-Fixation Method for the Identification of Bacterial Antigens. — As a means of diagnosis, this test has very limited practical value. It aims to detect, by means of complement fixation with a known antiserum, a soluble bacterial antigen in the blood-serum of a patient. For example, in typhoid fever the patient's serum is mixed with a potent antityphoid serum in the presence of complement. After incubating for an hour at 37° C., amboceptor and corpuscles are added to test for free complement. An absence of hemolysis indicates that complement has been fixed by the antiserum and soluble typhoid antigen in the serum of the patient. As a rule, and for purposes of diagnosis, this order of procedure is reversed: the antigen is furnished and then sought for in the patient's serum (p. 498), as in the gonococcus fixation test, syphilis reaction, etc. The bacterial extract is prepared as follows: Make cultures of the bacteria on slants of agar; wash off a sufficient number with normal saline solution until 20 or 30 c.c. of a heavy emulsion are secured; add 0.4 per cent, of phenol, arid shake mechanically with glass beads for twenty-four hours; then heat to 60° C. for an hour, and either centrifuge thoroughly or filter through a Berkefeld filter. The clear filtrate should be preserved in a tightly stoppered bottle in an ice-chest. It is well to titrate this extract for its anticomplementary dose. As a rule, these extracts are free from anticomplementary action until relatively large doses are employed. The antiserum is heated to 55° C. for half an hour and titrated with 0.01 c.c. of the bacterial extract (0.1 c.c. of a 1: 10 dilution) in 10 doses, ranging from 0.1 c.c. to. 1.0 c.c. Double the dose giving complete fixation of complement is used in testing for the bacterial antigen in human serum. In conducting this test the patient's serum is heated to 55° C. for half an hour, and decreasing doses, ranging from 0.5 c.c. to 0.01 c.c., are placed in a series of test-tubes together with double the titrated dose of antiserum. Complement and salt solution are now added, and after incubating for an hour at 37° C., amboceptor and corpuscles are added and the tubes reincubated. The general technic and controls are the same as those previously described. The test has some value in special research work, but for practical use it has given way to the agglutination reactions and complementfixation tests for the detection of antibody with a known antigen. practical value. More recently von Dungern1 has advocated a method that yielded 90 per cent, of positive reactions in known cases of cancer. Positive reactions have also occurred in tuberculosis and syphilis, and the reports of various other investigators are somewhat contradictory. Whitman, in a study of 30 cases, found the method highly satisfactory. Lucke2 has found the test of no value at all. especially their theoretic structure and the mechanism of their action. It will be remembered that the general name "cytolysin" is applied to an amboceptor or antibody of the third order of receptors that is capable of preparing its antigen for the disintegrative or lytic action of a complement. The two best known and most important members of this group of antibodies have been considered, namely, the hemolysins and the bacteriolysins. Following the discovery of the hemolysins and the bacteriolysins and of the mechanism of their action, it was not long before similar studies were undertaken with other cells, with the result that attempts have been made to prepare immune cytolytic serums for practically every organ of the body. This outcome was but natural, in view of the enormous theoretic importance of specific cytolysins, not only from the additional light that may be thrown upon physiologic and pathologic processes in general, but also from the standpoint of specific therapeutics. Nomenclature. — While actual lysis or solution of erythrocytes and bacteria may be brought about by antibodies of this order, yet actual solution is not apparent with most other body-cells, although a distinct toxic action may be observed. For instance, an antispermatozoa serum will cause these cells to lose their motility, but does not actually dissolve them. Hence the name cytotoxin has been applied to these immune serums. This is probably a better term than cytolysin; but it is to be remembered that, so far as is now known, both cytolysins and cytotoxins are antibodies that possess the same nature and structure, except that in the former group the process is complete and ends in actual lysis of the cell. The term cytolysin is, therefore, more appropriately applied to the bacteriolysin and hemolysins; whereas the term cytotoxin is reserved for those immune serums that injure their cells without complete lysis (a toxic action), such as nephrotoxin, hepatotoxin, etc. This chapter is mainly concerned with the latter group. METHODS OF STUDYING CYTOTOXINS 535 possess the same general properties as the bacteriolysins and hemolysins, except that, as will be pointed out later, they do not possess the same specificity. Without the presence of a complement they are inactive. They are thermostabile, possess the same general affinity for their antigen, and may be removed from a serum by saturation with the antigen in a manner similar to that used for the removal of a hemolysin. Preparation of Cytotoxins. — Cytotoxic serums are prepared by immunizing an alien animal with fine suspensions of cells of the particular organ being studied. (See p. 73.) Every effort should be made to remove all traces of blood, and to secure as pure an emulsion of the same cells and to work as aseptically as possible. Injections are best given intraperitoneally, rabbits being well adapted for the preparation of these serums. Beebe l has made the statement that more specific serums are obtained if the nucleoproteins are isolated and used in the process of immunization, than if the cells themselves are used. Wells,2 however, believes that the nucleoproteins of cells are not specific in character, and Pearce, Karsner, and Eisenbrey 3 found that nephrotoxic and hepatoxic serums prepared by the injection of the nucleoproteins of these cells, were no more toxic than serums prepared from the globulins and albumins of the same organs. Methods of Studying Cytotoxins. — While the phenomena of hemolysis and bacteriolysis may readily be observed in experiments in vitro, the influence of other cytotoxins on the particular cells used as antigens is more difficult to determine. The methods of exposing cell emulsions to the action of the serum have not been found satisfactory for testing the specificity of cytotoxins. The technic generally employed consists in making subcutaneous, intraperitoneal, or intravenous injections of the immune serum into the animal, or into the arteries leading to particular organs. Functional disturbances and delicate histologic changes in various organs have served as criteria for determining the degree of specificity that exists. The loss of some manifestation of vitality on the part of the cell, as a loss of motility (spermatozoa) or an inability to proliferate, may aid in studying the effect of these serums. Specificity of Cytotoxins. — As has been stated elsewhere, the hemolysins and the bacteriolysins are highly specific, especially the former group. With the cytotoxins, however, this specificity is not observed. Most cytotoxic serums are also hemolytic, notwithstanding the fact that careful precautions have been taken to remove, so far as possible, all traces of blood from the inoculum during the process of immunization. Metchnikoff found a spermatotoxic serum to be also hemolytic, but he believed that this property could be removed by treating the immune serum with the corresponding corpuscles, and in this manner dissolve out the hemolysin. Numerous other investigators have found, however, that cytotoxic serums may attack the cells of other organs, as well as those that have been used as their antigens. The subject has been very carefully investigated by Pearce.1 The injection of an antidog nephrotoxic serum prepared by immunizing rabbits with washed dog kidney is followed by the development of a tubular nephritis, with albuminuria and occasionally hemoglobinuria, and accompanied by granular degeneration of the liver. These serums are usually hemolytic in vitro. Similarly, in a study of hepatotoxic serums, Pearce found that the most striking lesions were referable to the hemagglutinating and hemolytic properties of the serum, causing thrombosis, embolism, and hemorrhages, whereas secondary necroses may be caused by a direct toxic action of the serum on certain parenchymatous cells. Pearce, Karsner, and Eisenbrey found that the serums of rabbits injected repeatedly with the nucleoproteins, globulins, and albumins of the liver and kidney of the dog, gave no evidence of organ specificity in vitro or in vivo experiments. These investigators were not able to support the view put forward that nucleoproteins play an important part in the production of cytotoxic immune serums. Lambert2 has recently studied the subject with cultures of rat sarcoma and rat embryo skin and their immune serums, and found that these cytotoxins were not specific for the tissue injected. These results are not surprising when it is remembered that all the body-cells have a common origin, and that, although the cells of various organs may differ considerably in morphologic and functional characters, they have certain receptors in common, and, as Pearce originally main- can be produced. Autocytotoxins. — While these toxins possess some theoretic interest, they are of very rare occurrence in experimental work. Certainly cells of the kidney, liver, and other organs are constantly dying and being replaced by new cells; the receptors of these cells are thereby set free, and are capable of forming a union with the receptors of other cells, and the possibility for the formation of autocybotoxins is established. According to Ehrlich, however, the side-arms anchoring the receptors of the dead cells are sessile in nature, and are unlikely to cause overproduction, as in the case of antibodies for bacterial substances or for the cells of other species. On the other hand, a simultaneous production of antiautotoxins that counteract the autotoxins and preserve a delicate physiologic equilibrium may occur, the whole subject being, however, still in the experimental stage. Of most interest in this connection are the theoretic autonephrotoxins. These may be produced when part of a kidney becomes disorganized in the living body, as by means of a toxin. Theoretic autotoxins may then be produced, which, acting upon other kidney cells, institute a vicious cycle. Acting upon these assumptions, Ascoli and Figari 1 and Lindeman 2 have proposed a new theory as to the pathogenesis of certain of the nephritides. These observers would account for the cardiac hypertrophy of nephritis by attributing it to the action of the nephrotoxic serum in causing contraction of the peripheral vessels, with consequent increase of blood-pressure; the nephritic nervous symptoms, they believe, are due to the fact that the serum contains a neurotoxic constituent. Lindeman has produced a toxic nephritis in dogs by giving them injections of potassium bichromate, and found that the serum, although free from the chromate, was toxic to other dogs, a finding he believed due to the presence of antonephrotoxins produced in the first dog as a result of the destruction of kidney cells. According to this view, the original toxic cause of a degenerative nephritis would be less responsible for the continuance of the process than would the formation of an autonephrotoxin. While these conclusions are somewhat far-reaching, they serve to indicate that the same processes operative in bacterial infection and immunity may have an important relation to other pathologic conditions. 538 CYTOTOXINS It is not rarely observed that in large tumors and similar lesions certain groups of cells may undergo digestion, but in these the lysis is commonly ascribed to the action of ferments liberated upon the death of cells. Isocytotoxins have been produced experimentally, as, for example, by Ehrlich, who produced isohemolysins by injecting goats with goat blood, and by Metchnikoff, who prepared isospermatoxic serums. munization with cytotoxic serums. Varieties of Cytotoxins. — As previously stated, attempts have been made to prepare cytotoxic serums for practically all the organs and tissues. Since none of these has been found to be absolutely specific, and hence since they possess little or no practical value, they will receive but brief consideration here. 1. Spermatotoxin. — This serum was prepared simultaneously by Metchnikoff1 and Landsteiner in 1899, and was one of the earliest cytotoxins to be studied. It is a hemolytic serum, and causes spermatozoa to lose their motility. It would seem to affect also the vitality of the spermatozoa in vivo, inasmuch as De Lester, by the injection of this serum, rendered male mice sterile for from sixteen to twenty days. 2. Epitheliotoxin. — A cytotoxic serum for the ciliated epithelium of the trachea was. prepared by von Dungern.2 The cells became disintegrated in the peritoneal cavity of the immunized animal, but not in that of the normal animal. This serum also proved to be hemolytic. proved futile. 3. Leukotoxins. — This serum was first prepared by Metchnikoff3 and Besredka4 by injecting the spleen of rats into guinea-pigs. The serums have also been prepared by effecting immunization with exudates rich in leukocytes or with the emulsion of lymphoid organs (Flexner and Ricketts) . They are usually hemolytic, and also attack endothelial cells. Their action may be observed in vitro when the leukocytes lose their ameboid motility and the protoplasm swells, clears, and may disintegrate, leaving the nucleus. ..,..'- VARIETIES OF CYTOTOXINS 539 of the cytotoxins. As shown by Pearce, with the aid of this serum physiologic and anatomic alterations and lesions are readily studied. The injection of a nephrotoxic serum produces a tubular nephritis, with albuminuria and possibly hemoglobinuria. The serums are usually hemolytic, and frequently cause degenerative lesions in the liver, due in part to hemolysis and hemagglutination of red corpuscles. 5. Hepatotoxin. — Delezenne l was the first to work with the so-called hepatotoxin, which, he claimed, possessed absolute organ specificity. Subsequent investigations, however, have brought forth contradictory findings. Pearce found that hyaline thrombi, formed of agglutinated red corpuscles, are primarily responsible for the areas of necrosis and hemorrhage, with secondary effects, which may be ascribed to a cytotoxin liberated chiefly by the cells in the thrombus, and acting on the livercells. These findings and views have recently received support from the investigations of Karsner and Aub.2 6. Gastrotoxin. — Gastrotoxic serums have been studied by Bolton,3 who immunized rabbits with emulsions of the mucosa of the stomach of the guinea-pig. The injection of this serum into guinea-pigs was followed by the development of areas of hemorrhage, necrosis, and ulcer formation that resembled peptic ulcers. According to Bolton, if the gastric secretions were neutralized with large quantities of alkali, the ulcers did not develop, indicating that the peptic ferments may be operative in the digestion of the cells after their destruction by the immune serum. Gastrotoxic serums were found to produce precipitates with clear filtrates of gastric cells, and were also shown to be hemolytic. 7. Synocytotoxin. — This serum has been produced experimentally by immunization with an emulsion of placental cells. According to Liepmann,4 it produces a precipitate with a filtrate of placenta cells, and at one time it was believed that it might constitute a diagnostic test for pregnancy. Syncytotoxins are interesting as considered in reference to eclampsia and other toxemias of pregnancy. As is well known, placental cells may become detached and, gaining entrance to the circulation, become lodged in remote organs (Schmorl). This has given rise to the theory that a placentotoxin is developed that produces the nephritis of pregnancy and necrotic lesions in the liver. Weichardt asserts that, by digesting placenta in vitro with an active placentotoxic serum and in- jecting the digestate, he produced symptoms resembling eclampsia in the lower animals. It was hoped that an anticytotoxic serum might be prepared to combat the effects of the placentotoxin, but this hope has not been realized. Renewed interest in this particular subject has been manifested by the recent studies of Abderhalden in ferments as applied to the diagnosis of pregnancy (p. 258). 8. Neurotoxin. — This toxin has been prepared and studied by Delezenne, Centanni, Delille, and others, by immunization experiments with emulsions of cerebrum, cerebellum, and spinal cord. When injected into the brain direct, these serums may cause profound intoxication of the nerve-centers, with torpor or convulsions, subnormal temperature, and death. When injected directly into the veins, they are usually without effect. In addition to their neurotoxic action, they are generally hemolytic, and frequently endotheliotoxic and leukotoxic. 9. Thyrotoxins. — This serum is prepared by immunizing animals with emulsions of thyroid gland. Thyrotoxins were quite prominently before the profession a few years ago, owing to the work of Beebe, who advocated their use in the treatment of various goiters. They have not fulfilled their expectations, however, since they may also produce degenerative changes in the various organs, as the liver, spleen, and kidneys. ROLE OF CYTOTOXINS IN IMMUNITY It is apparent that, according to our present knowledge, the cytotoxins proper, although they possess great theoretic importance from their possible relationship to the removal and disposal of enfeebled and dead cells, occupy a subsidiary place in the processes of immunity. The processes governing these changes are finally and delicately balanced, and although obscure, they offer an intricate but fascinating field for research. If the ferments concerned in Abderhalden's studies are related in any way to the cytolysins, the subject becomes of great interest, and a new field, with immense possibilities, is opened for further study. Practical Applications. — (1) In therapeutics the cytotoxins have not established a place for themselves and their use has been disappointing. As previously stated, the use of thyrotoxic serums has not met with considerable success; epitheliotoxic serums have likewise not been efficient in the treatment of cancer. They possess theoretic interest, however, from the possibility of their so injuring glands that their functions may be studied; theoretically, the use of minute and carefully hemolysins and aid in the treatment of certain anemias. (2) In diagnosis cytotoxic reactions have been employed by Freund and Kaminer. These observers used the cytotoxins as a diagnostic aid in cancer, but with indifferent success. Abderhalden's pregnancy test possesses some practical value, and a similar technic has been successfully employed in the diagnosis of cancer. The work of Abderhalden has served to open up a comparatively new and intensely interesting field, which, when fully developed, as the result of overcoming difficult technical procedures, may offer additional means in the diagnosis of various diseases. This test has been described elsewhere under the head of Ferments (p. 265). CYTOTOXIC REACTIONS Cytolytic Cancer Diagnosis of Freund and Kaminer.1 — This reaction is based upon the observation that while normal serum has the power to dissolve cancer cells, the serum of cancerous persons lacks this property, and has the power to inhibit the destruction of such cells by normal serum. The same authors have also observed that when cancer serum is mixed with an extract of cancer cells a precipitate forms. They claim to have secured 88 per cent, of positive reactions in 113 cases examined, and believe that the reaction occurs early enough and is sufficiently specific to render it of practical value. These observations, however, have not been sufficiently confirmed. An emulsion of cancer cells is prepared by grinding the undegenerated portions of a tumor, freed as much as possible from fat and fibrous tissue, in a mortar and adding about five volumes of 1 per cent, sodium biphosphate. The suspension is filtered through several layers of gauze, and after the cells have become precipitated, the supernatant fluid is decanted. The residue of cells is washed with 0.6 per cent, sodium chlorid and allowed to settle again, the supernatant fluid is decanted, and the residue covered with 1 per cent, sodium fluorid. The lastnamed fluid must first be neutralized against alizarin until only a trace of the violet color remains. The emulsion will keep for several weeks in an ice-chest. Serum.— The patient's serum should be collected just a few hours (not over twenty-four) before the test is to be made, and must be clear and free from cellular elements. The Test. — To 10 drops of the patient's serum add one drop of 0.5 per cent, solution of sodium fluorid. Then add one drop of the cancercell emulsion so diluted that when one drop of the mixture is placed in a blood-counting chamber, about 10 to 20 cancer cells will be found in a field of four large squares. Close the counting chamber carefully, ring with vaselin to prevent evaporation, and place in the incubator for twenty-four hours. All slides are incubated for twenty-four hours at 37° C. and the cells counted. A material reduction in the number of cells with the normal serum will be noted; if the patient has carcinoma, the first and second slides will not show this reduction, whereas if the patient is free from cancer, similar reduc.tions will be found in all three slides. THE RELATION OF COLLOIDS AND LIPOIDS TO IMMUNITY WHILE at the present time Ehrlich's side-chain theory best explains the specificity and mode of action of various antibodies, there is a growing tendency to explain many of these reactions on a physicochemical and colloidal basis. From the fact that, without exception, antigens are colloids, and that antibodies also are colloid in their chemical characters, it is advisable to review briefly some of the main facts and theories concerning these bodies and their reactions. colloids. Nature and Properties of Colloids. — Since Graham,1 in 1861, studied the differences between the substances that did or did not diffuse readily through animal or parchment membranes, soluble substances have been classified in two main groups : (a) Colloids, or those substances that were dissolved to the extent of showing no visible particles in suspension, but that did not pass through diffusion membranes at all, or did so very slowly indeed, and (6) crystalloids, or solutions that diffuse through membranes quite readily. Since Graham's discoveries investigations have shown that any and all substances may be either colloid or crystalloid, depending upon the treatment they receive; thus albumin may be crystallized and common table salt obtained in a state of colloidal solution.2 Furthermore, there is much evidence indicating that all colloid systems are unstable and never in equilibrium; conditions which determine the appearance of a body in the colloid or crystalline form appear to indicate that bodies always separate from solution in the amorphous or colloidal condition and that all crystallization is a secondary phenomenon. On the other hand, we may have substances that are quite insoluble when aggregated in masses, but when derived in pure form by mechanical means can be suspended and uniformly distributed through a fluid without showing any marked tendencjr to precipitate. Such suspensions or emulsions contain particles that are visible under the microscope; they usually appear turbid, do not transmit electricity, and are not diffusible. Colloids occupy a place between the true solutions of crystalloids and the emulsions. Sharp boundaries cannot usually be drawn between any of the members of the series. They differ quantitatively in some manner from the true solutions and the emulsions, but may approach them closely, and sometimes resemble them so strongly as to be almost indistinguishable from them. For the most part, however, they show decided characteristics that will differentiate them from the crystalloids, on the one hand, and the suspensions, on the other. Those colloids that closely resemble the true solution have been designated " colloidal solutions/' and those resembling more closely the suspensions, "colloidal suspensions." Of the two types, the colloidal solutions are far more important biologically, since the colloidal suspensions are usually prepared artificially and seldom occur in nature. Colloids, therefore, appear to be suspensions of masses of molecules, or perhaps of very large single molecules. When these aggregations are sufficiently large, we have an ordinary suspension. When colloids occur in a highly dispersed state they are called sols; when in an undispersed or but slightly dispersed state they are spoken of as gels. A colloid substance may be converted from a sol state into a gel state and back again, when it is called a reversible colloid or emulsion; a colloid which refuses to redisperse is an irreversible colloid or suspension. 1. Colloids are usually amorphous in character, and with few exceptions do not present a typical structure; they are not crystalline under any visible condition. This, however, is not invariably the case, for we may have a 'protein, like hemoglobin, which resembles a typical colloid in every respect, and may yet form crystals readily and abundantly. 2. Colloids do not form true solutions, but the solvent is probably an important factor in determining whether or not a substance is colloidal in nature; e. g., soaps form true solutions in alcohol and colloidal solu- NATURE AND PROPERTIES OF COLLOIDS 545 tions in water; rubber forms colloidal solutions in ether, but not in water. The term colloidal solution does not, therefore, refer to a true solution in the sense of a crystalloid, but to a colloidal state of suspension (the so-called colloidal solution). 3. Colloids are non-diffusible, or lack the power of passing through animal and parchment membranes. Not all colloids possess the same rate of diffusion, this property being relative, rather than absolute; however, solutions of salts (crystalloids) pass through so readily that they are easily separated from proteins (colloids) by dialyzation, a process that is in constant practical use. 4. Colloids have an extremely small osomotic pressure. They may, to a very slight degree, exert some influence upon osmotic pressure, the freezing and boiling-points of fluids, but in all cellular processes in which manifestations of osmotic pressure or diffusion are present the crystalloids may be considered as almost entirely responsible for these. 5. The colloids exhibit surface tension to a high degree — in other words, colloid fluids possess the force that strives to reduce its free surface to a minimum. As partial expressions of this force, the formation of emulsions when oil and water are mixed and the ameboid movements of the ameba and leukocytes may be mentioned as examples. 6. Colloids do not separate freely into ions when dissolved, and accordingly do not conduct electricity to an appreciable extent. When an electric current is passed through a colloidal fluid, most of the colloids move toward the anode; this phenomenon, known as cataphoresis, is also generally exhibited by suspensions, and in this particular the colloids resemble suspensions. 7. Colloids are usually easily precipitable and coagulable, and this is readily understood when the slender margin that exists between many of the colloids and the suspensions is borne in mind. Relatively slight changes, such as exposure, gentle heat, the presence of large quantities of crystalloids, the action of enzymes, etc., may throw an organic colloid out of solution, and when once precipitated, it is often incapable of again dissolving in the same solvent. Colloids are also precipitated by many electrolytes, apparently through the formation of true ion compounds. 8. The physical structure and size of colloids. This subject has been studied extensively by Hardy.1 Cells contain but one, type of colloids, the proteins that form non-reversible coagula. So long as a colloid is in solution it is structureless; but such solutions may become solid as the result of changes of temperature and other physical means and from admixture with certain chemical fixing agents. The structure of the coagula varies according to the concentration of the colloidal solution and the nature of the coagulant, but in general the figures obtained in the solidification of protein solutions by such fixing agents as mercury bichlorid and formalin bear a striking resemblance to the finer structure of protoplasm as described by cytologists. These facts, no doubt, have an important bearing upon the various "foam," "reticular," and "pseudo-alveolar" structures of the protoplasm of cells described by Biitschli, Fromann, Arnold, Reinke, and others, and may indicate the effect of fixatives upon colloid solutions, explaining the usual time-worn objections to theories of protoplasmic structure as based upon artificial conditions not present in the normal living cell, and variously interpreted according to the fixative employed. Studies in the size of colloidal particles have been greatly facilitated by dark field illumination of the microscopic field or the so-called ultramicroscope devised by Siedentopf and Zsigmondy. Various other methods have been devised for studying the size of colloidal particles, as ultrafiltration by Bechhod1; the weight of a dispersed substance in a given volume by chemical or other analysis; by studies in the density of the dispersed substance and other methods. These studies have indicated that colloidal particles are usually round or at times ovoid, as indicating beginning crystallization; that the main difference between suspensions and colloidal solutions is one of dispersion and not relative size of particles, and that in a true colloidal solution particles of widely differing sizes may be found side by side. 9. Colloids may be precipitated by electrolytes of opposite sign, as well as by colloids. In a colloidal solution surface tension constantly tends to make the particles of colloid approach one another, so that the surface may become as small as possible, and in this manner brings about precipitation or coagulation. In a stable solution this action is counterbalanced by a force of electric repulsion. Pure colloids do not carry an electric charge and are not conveyed by an electric current; their apparent charge depends upon the nature of electrolytes that may be present. Traces of acid and of acid salts give it a positive charge, whereas alkalis and alkaline salts do the opposite (Pauli). can be accomplished either by electrolytes or by colloids: (a) Precipitation by electrolytes is best illustrated by the action of a strong acid on an albuminous solution. The negatively charged particles attract to themselves the positively charged hydrogen ions; their charge is now neutralized, and the force of attraction due to their surface tension is no longer counterbalanced by an electric repulsion. The particles are drawn together, form larger and larger masses, which finally come under the influence of gravity and precipitation takes place. (6) Precipitation of colloids by colloids is illustrated by the precipitation of albumin by acetic and ferrocyanic acids. The colloid must be of opposite sign. As a result of the acid the particles acquire a positive charge, if they are not so charged already. This charge is then neutralized by the colloidal ferrocyanic acid of negative sign; the surface tension is no longer neutralized by an electric repulsion, and particles come together to form larger masses that are finally deposited as a precipitate. Instead of precipitating the other, an excess of one colloid may act in a reverse manner. For example, as Neisser and Friedmann have shown, a suspension of particles of mastic in water (made by dropping an alcoholic solution in water) takes on a negative charge, and can be precipitated by positive colloids or ions, such as ferric chlorid. If the dose of ferric chlorid is increased gradually, the precipitate becomes more and more abundant, until an excess of ferric chlorid is present, when the reaction ceases and the precipitate may be redissolved. This has been explained on the assumption that when two colloids of opposite sign are mixed, they tend to fuse and form masses; the addition of an excess of either colloid tends to electrify the masses, causing mutual repulsion and possibly resolution of the masses. Hence the precipitate is soluble in an excess of both substances, just as a precipitate is soluble in an excess either of precipitin or of its antigen. 10. Absorption is the taking up of dissolved or volatile substances by finely divided or colloidal bodies. It is a combination between two substances dependent on physical attraction rather than on chemical affinity, and taking place in variable ratios, rather than in simple and constant ones, as occur in a true chemical union. It is believed by many that the two substances entering into the phenomenon of absorption exist as such side by side in the compound, which is to be regarded as an intimate admixture of the two, rather than as a new compound. shown by Bordet in the amount of hemolytic immune body that can be taken up by a given volume of corpuscles — i. e., the amount varies according to whether the corpuscles are added at once or in successive small portions. Thus, in one example, 0.4 c.c. of a hemolytic serum dissolved 0.5 c.c. of corpuscles if added at once; but if 0.2 c.c. of corpuscles was added first and successive amounts of 0.1 c.c. then put in, no solution took place after the one that followed the addition of the first portion. This was explained by Bordet according to the principles of absorption, this observer comparing it with the absorption of a dye by filter-paper. While other explanations are possible, yet exactly analogous phenomena may be seen in the mutual absorption of colloids of opposite sign. Thus, as we have previously stated, the addition of a solution of an electropositive colloid to a solution of an electronegative one tends to repel the particles, with the formation of masses for the purpose of self-protection, and in this manner the process of agglutination and precipitation is begun. But if a small amount of a second colloid is added to the same volume of the others, new aggregates of the two are formed that are less favorable to precipitation and require more of the second colloid to bring about complete precipitation. CHEMISTRY With these few brief remarks on the properties and nature of colloids and the close resemblance of cellular protoplasm and fluids to colloids, we may consider briefly the apparent similarity that exists between the colloidal reactions and some of the reactions of immunity. This is especially pertinent for several reasons : it has been shown that cellular protoplasm is colloidal in nature; that antigens are certainly colloidal, and that antibodies, while they may or may not be solutions of colloids, are, in the final analysis, products of cellular activity, and therefore derived from colloidal solutions. 1. Antitoxins. — The side-chain theory of Ehrlich was first applied in explanation of the principles of immunity as affording an explanation of the action of toxins, the formation of antitoxin, and the interaction between these. Ehrlich has placed the various phenomena of immunity upon a chemical basis, bringing forward new theories to explain the various discrepancies that were found. For example, it was soon found that both toxin and antitoxin were unstable, and that neutralization of a toxin by the addition of antitoxin was not a simple process, like the neutralization of an acid by an alkali, but, on the contrary, was likely to ANALOGY BETWEEN REACTIONS 549 be exceedingly complicated. This was explained as being due to the degeneration of toxin into various toxoids, which were able to neutralize antitoxin without being in themselves toxic when in a free state. They were likewise found to have a greater affinity for antitoxin than the toxin itself, so that when a toxin was tested and its toxicity determined, it was discovered that more antitoxin was needed to neutralize the mixture than was originally calculated, because the toxoids took no part in testing the toxin, but were active in uniting with antitoxin, and in this manner leaving true toxin unneutralized, and therefore toxic, unless an excess of antitoxin was used. Analogous conditions may be observed among colloidal solutions. Thus, Danysz has shown that more toxin is neutralized if antitoxin is added at once than when it is added in successive doses. As stated elsewhere, this is explained by Ehrlich upon the assumption that time is allowed for the degeneration of toxin into toxoids to take place, the latter having a greater affinity for the antitoxin. It has been shown, however, that in some cases the addition of a small amount of a second colloid of opposite sign to a colloidal solution may render the solution more stable and protect it from precipitation by an excess of the second substance. Similarly, the amount of colloid necessary to precipitate a constant amount of another colloid is reduced to a minimum if the addition is made at once, and is rendered much greater if the colloid added is made slowly in small amounts, an interval being allowed to elapse after each addition. This is closely analogous to the Danysz reaction, and explains the latter as being due, when antitoxin is added slowly to toxin, to the formation of transitional compounds of toxin and antitoxin of diverse nature, requiring more antitoxin for complete neutralization of the toxin than if the antitoxin were added at once and in one dose. The difference between the L0 and L+ dose of a toxin also has an analogy in the reaction of simple colloidal substances. Thus, Bilty has used ferric hydroxid, which neutralizes arsenic trioxid (the antidote for acute arsenical poisoning), and found that the addition of one lethal dose of arsenic to a neutral mixture of the two did not render the mixture toxic, but that several lethal doses were required, just as it is necessary to add several instead of one lethal dose of diphtheria toxin to the LO dose. Thus it would appear that the neutralization of a toxin by an antotoxin has analogies among the known and simple colloidal reactions. One objection to placing the toxin-antitoxin reaction upon a colloidal basis is that both have the same electric charge, i. e., both move toward the cathode, and, as we have seen, for the neutralization and precipitation of colloids the solution of colloids should be of opposite sign. It must be remembered, however, that toxins and antitoxins react in very complex fluids containing other substances consisting of both colloids and electrolytes, and until the electric charge of these in pure form is determined, the apparent similar electric charge of toxin and antitoxin can hardly outweigh the otherwise remarkable analogy it bears to colloidal reactions. 2. Agglutinins and Precipitins. — Various theories in explanation of the phenomenon of agglutination have been described in a previous chapter. The theory of Bordet appears to be best, and is based upon certain principles of colloidal chemistry. When bacteria are suspended in a fluid free from salt, agglutination does not take place because the bacteria carry a similar negative charge of electricity. When, however, ions of positive charge are added, as, e. g., sodium chlorid, the bacteria or other cells are repelled and coalesce to form masses, according to the laws of surface tension, in an effort to protect themselves. Larger masses may be formed that finally come within the influence of gravity and are deposited at the bottom of the test-tube. According to the same laws, the addition of agglutinin removes the negative charge of bacteria or other cells, with the consequent formation of clumps and masses. Similar phenomena may be observed in the precipitation of colloidal suspensions of clay in distilled water by the addition of a salt. Solutions of inorganic colloids, as, for example, that of silicic acid, may agglutinate red corpuscles; bacteria, such as suspensions of typhoid and colon bacilli, may be agglutinated by solutions of the ferric salts. Just as an excess of one colloid solution will charge masses of the other, resulting in a repelling action and breaking up of the agglutinated clumps, so the addition of an excess of agglutinin is found to prevent agglutination or to give but a slight reaction. This phenomenon has been explained, according to Ehrlich's side-chain theory, as due to the presence of agglutinoids that have a great affinity for the bacteria and unite with them without being active in the free state, owing to a loss of the agglutinophore portion of the molecule. Each cell united with an agglutinoid is one cell less to undergo agglutination by agglutinin, and accordingly in weak dilutions of serum agglutination is feeble or absent whereas hi higher dilutions the phenomenon may be clearly observed. Friedmann have shown that suspensions of mastic may be ''protected" against the precipitating action of ferric hydroxid by the addition of a small amount of organic colloid, such as serum, leech extract, or extract of typhoid bacilli, regardless of whether this colloid is charged positively or negatively or is neutral. The aforenamed observers believe that normal bacteria may be surrounded by a similar protective envelop that prevents the agglutinating action of substances of opposite sign. The action of agglutinin, therefore, would be to remove this layer, so that the ions of opposite electric charge can unite with the bacteria and bring about their agglutination. This may be an explanation of the role of salts in the phenomenon of agglutination, the agglutinins removing the protecting envelops and the salt furnishing the ions of opposite charge that bring about agglutination. Owing to the fact that a discrepancy arises here for the reason that emulsions of red corpuscles are agglutinated by both positive and negative colloids (ferric hydroxid and cuprum ferrocyanid), Girard, Mangin and Henri have given the following explanation of agglutination: When a red corpuscle is suspended in a fluid, various salts, especially the sulphates of magnesium and calcium, are diffused, which tends to facilitate the precipitation of negative and positive colloids, so that each corpuscle comes to be surrounded by a layer of precipitated colloid material. This zone of precipitated colloids of either negative or positive charge determines agglutination in the presence of a colloid solution of opposite charge, such as agglutinin or inorganic colloids (silicic acid, etc.). 3. Hemolysins. — Reference has been made elsewhere to the original observations of Bordet, showing that red corpuscles may absorb much more hemolytic antibody than is necessary to bring about their lysis, and that this absorption is analogous to colloidal absorption. Inorganic colloidal solutions, such as that of silicic acid, may produce hemolysis of red blood-corpuscles, e. g., those of the rabbit. Its action is manifested in extremely small doses. It is rendered inert by heat, and gradually deteriorates at room temperature. Furthermore, this inorganic colloid possesses some of the properties of a serum hemolysin; thus mice red corpuscles that have been agglutinated by colloidal silicic acid are dissolved by traces of lecithin or of fresh serum, but not by serum that has been heated to 60° C. (inactivated). An excess of silicic acid tends to prevent hemolysis, which is another example of the action of an excess of one colloidal solution upon another of opposite sign. THE COMPLEMENT-FIXATION TEST AS A COLLOIDAL REACTION Many observations support the view that complement fixation by a specific antigen and its antibody is really complement absorption by a precipitate that forms when antigen and antibody are mixed. As previously stated, all antigens are protein in character. While there is some evidence to show that lipoids, and even carbohydrates, may act as antigens, there is no doubt but that the chief antigenic principles of any antigen are of protein structure; hence when mixed with an immune serum containing specific antibodies, it is believed that an invisible precipitate is formed that absorbs the complement. With serum antigens the quantity of protein is so large that a precipitate can readily be seen (the precipitin test). A serum antigen and its antibody may, however, be so highly diluted that, when mixed, a precipitate is not visible, although complement may be fixed (complement-fixation test for the differentiation of proteins). Moreschi and Gay have contended for many years that complements may become entangled and absorbed in such precipitates. Reasoning on the basis of the colloidal theory, it is possible that transition compounds of very diverse nature are formed when antigen, antibody, and a complement are mixed. This view on the action of complements and anti-complements is supported by numerous investigators who have examined the question from the standpoint of colloidal reactions. Thus in a complement-fixation test a mixture of antigen, antibody, and a complement in definite proportions results in the formation of new compounds of opposite electric charge, which tend to aggregate in masses (although these may be so small as to be invisible) and reduce their surface tension in just the same manner as agglutination and precipitation are brought about after the colloidal theories. When corpuscles and hemolytic antibody are subsequently added, hemolysis does not occur because free complement is absent. A process similar to complement absorption by a specific antigen and its antibody is the Wassermann reaction. According to the colloidal theories, this reaction may be explained as due to the formation of an invisible precipitate by interaction between some substance in the serum of a luetic person (probably in the nature of an altered globulin), complement, and lipoidal substances contained in an alcoholic or watery extract of a normal or a diseased organ. This view is supported by the fact that euglobulin is known to be generally increased in the body fluids of syphilitics, and by analogy with the various precipitin tests that have been devised for the diagnosis of syphilis, as, for example, the reaction of Forges and Meier, which is dependent upon the appearance of a precipitate when luetic serum is mixed with an emulsion of lecithin or sodium glycocholate, etc. The exact nature of the antibody in syphilitic serums that forms these new compounds with lipoids and complement, resulting probably in the absorption of complement, is unknown. It is most likely in the nature of a globulin, its main characteristic being the power it possesses of reacting with lipoids. Schmidt l ascribes the reaction to the physicochemical properties of the globulins of the syphilitic serum, which he believes possess a greater affinity for the colloids of the antigen than do normal globulins. This view is supported by the common observation that the turbidity of the antigen emulsion is closely related to its efficiency, since clear solutions are less active. Since various lipoidal substances may be employed, the Wassermann reaction can not be regarded as specific in the immunologic sense, although practically it is highly specific, as similar conditions are to be found in only two other diseases with any degree of regularity, namely, frambesia and tuberous leprosy. phenomena. As stated in Chapter VIII, the results of some researches that go to show certain lipoids and lipoidal substances may act as true antigens and produce antibodies.2 This, however, has not been definitely proved, and while it is of great importance, is not necessarily pertinent to the subject in hand. As the relation of lipoids to various immunologic processes has frequently been described in earlier chapters, as, e. g., where the role of lipoids in venom hemolysis, in the Wassermann syphilis reaction, and in the various preoipitin reactions in syphilis were considered, a brief resume may be of service in directing attention to this important and particular phase of immunity. 1 Zeit. f. Hygiene, 1811, 69, 513. 2 Bibliography on Lipoids and Immunity given by Landsteiner, Kolle and Wassermann's Handbuch, 1913, 2, 1240. Also review of literature by Landsteider, Jabresb. Immunitat, 1910, 6, 209. Relation of Lipoids to Hemolysis. — (a) From the standpoint of immunity, venom hemolysis is of peculiar interest as indicating the possible important relation of lipoids to hemolytic complement. Granting that venom contains a hemolytic amboceptor (Flexner and Noguchi), the complementing substance must be derived from the corpuscles, and, according to Kyes, this complementary agent is represented in lecithin. Kyes was able to produce what he considers are compounds of the hemolysin with lecithin, namely, "lecithids." Whether these "lecithids" are true compounds of hemolysins and corpuscular lecithin or simply the active hemolytic products of the cleavage of lecithin by ferments contained in the venom, is at present unknown. Noguchi and Lieberman have shown that not only lecithin, but soap as well, especially unsaturated fatty acids, and probably protein compounds of soaps and lecithin, may act as the hemolytic complement and activate the hemolysin of the venom. Lipoids from bacteria and trypanosomes have been found to possess similar properties. Hemolytic lipoids have been secured from serum, and the complementary activity of a fresh normal serum may be destroyed by fat solvents, e. g., ether. While other investigators have not been able to confirm Noguchi's attempts to produce an artificial complement of fatty substances of exactly the same properties as serum complement, this work indicates most strongly the close relation of serum complement to lipoids. (b) The hemotoxic activity of various toxins is probably dependent largely upon their action on the lipoids of red corpuscles. The saponin substances, l a group closely related to glucosids, and found in at least 46 different families of plants, are strongly hemolytic. Ransom2 has found that an ethereal extract of red corpuscles contains a substance that inhibits saponin hemolysis. This substance consists largely of cholesterin, and it is the presence of cholesterin in normal serum that inhibits saponin hemolysis. This may be demonstrated experimentally by adding cholesterin to a solution of a saponin. Noguchi 3 has shown that lecithin does not possess the same antihemolytic action on saponin. It would appear, therefore, that saponin causes hemolysis by combining with, altering, or dissolving the lipoids of the stroma of corpuscles. The resistance of corpuscles to saponin hemolysis varies in certain diseases, being especially low in jaundice (McNeil)4. While saponins, solanins, phallin, and other vegetable poisons are of relatively simple chemical composition and quite unlike proteins, enzymes, or toxins, it is possible that bacterial and vegetable hemotoxins, such as tetanolysin, abrin, ricin, crotin, and robin, may produce their effects by a similar action on the lipoids of the erythrocytes. Noguchi has shown that cholesterin inhibits the action of tetanolysin. Landsteiner and Bottori have found that protagon, a brain lipoid, possesses the property of binding tetanus toxin, which indicates that this toxin may produce its effects by some action upon the lipoids of nerve-cells. (c) The important relation of lipoids to the Wassermann reaction and certain precipitin or floccule-forming reactions (Klausner, Porges-Meier, Hermann-Perutz) has been mentioned repeatedly. Just what role the lipoids play in these phenomena is not known. While the globulins of syphilitic serums are strongly suspected of being concerned in these processes, their relation is not clear. Klausner1 now believes that the precipitate that forms when distilled water is added to syphilitic serum is due to the high lipoid content. Principles. — According to the exhaustive studies of Zsigmondy2 on metallic colloids a solution of a protein will precipitate colloidal gold in the absence of an electrolyte. An electrolyte, as sodium chlorid, will in certain concentrations precipitate the colloidal gold itself; if proteins are present this precipitation is inhibited. The degree of protection afforded has been found specific for each protein, and is expressed in terms of milligrams of the protein capable of protecting 5 c.c. of colloidal gold against 0.5 c.c. of a 10 per cent, solution of sodium chlorid. Lange3 endeavored to distinguish between normal and luetic sera by this means on the basis of disturbances in syphilis, but failed; he then sought to measure the protein content of cerebrospinal fluid by the degree of precipitation of gold, but failed again, because he used distilled water as a diluent, thereby throwing the protein, particularly the globulins, out of solution, and rendering them inert. When, however, he used a 0.4 per cent, solution of sodium chlorid as a diluent it was found that the proteins were not precipitated and that this amount of salt was too weak to precipitate the colloidal gold. It was now possible, according to Lange, to measure the protein content of spinal fluid according to the degree of precipitation, and very interesting and practical results have been secured, although it cannot be stated as proved that the precipitation is due entirely to protein, particularly since it has been shown that the globulins may actually protect colloidal gold against precipitation. Zaloziecki1 regards the reaction as a form of immunity reaction; Jaeger and Goldstein2 consider it purely physical and probably of an electric nature. Preparation of Colloidal Gold. — The preparation of colloidal gold is frequently an exceedingly troublesome procedure, and the success of the test depends upon a satisfactory preparation. The method which I shall briefly describe here is after that of Miller, Brush, Hammers, and Felton,3 which I have found to yield fairly constant and satisfactory products. The glass-ware (beakers, pipets, and test-tubes) must be absolutely dean. They may be washed in hot water with ivory soap; rinsed in tap-water for five minutes; placed in hot bichromate cleaner for half an hour; rinsed in tap-, and finally triple distilled water. The beakers should be used at once; the pipets and test-tubes are to be dried in a hot-air oven. Thermometers should be cleansed in a similar manner. in a prepared beaker with a thermometer. 2. At 60° C. add 10 c.c. of a 1 per cent, solution of Merck's gold chlorid c^stals in triply distilled water and 7 c.c. of a 2 per cent, solution of Merck's blue label potassium carbonate in triply distilled water. 4. At 90° C. remove the burner and, while stirring, add 5 c.c. of a solution of 1 c.c. of Merck's highest purity formaldehyd in 40 c.c. of triply distilled water, or enough to produce an initial pink color. 5. The solution must be neutral in reaction when used, and for this purpose is tested with a 1 per cent, solution of alizarin red in 50 per cent, alcohol. With this indicator the neutral point is a brownish-red tint; an acid solution gives a lemon-yellow, and an alkaline solution a purplish-red, color. To 10 c.c. of the colloidal gold in a clean beaker add 2 drops of indicator. If it is acid, titrate to the neutral point with -f$ NaOH; if alkaline, with ^ Hcl. Calculate the amount to be added for the amount of colloidal gold solution at hand and neutralize with normal or decinormal solutions of acid or alkali as required. with a known pare tic fluid. The Test. — 1. Arrange eleven clean, dry test-tubes in a row; put 1.8 c.c. of fresh, sterile 0.4 per cent. NaCl solution into the first tube and 1 c.c. in the following ten. 2. With a clean, dry pipet add 0.2 c.c. of a blood-free cerebrospinal fluid to the first tube and mix; transfer 1 c.c. from the first to the second tube, mix, and proceed in this manner up to and including the tenth tube, from which 1 c.c. is discarded. The eleventh tube is the control and contains no cerebrospinal fluid. The dilutions now range from 1 to 10 to 1 to 5120. 3. Add to each tube 5 c.c. of colloidal gold; mix and stand aside at room temperature over night; the readings are made the next day and recorded by numbers according to the following scheme: or, at most, a No. 1 change in the first tube of the series. 2. The typical reaction is observed in general paresis, giving complete precipitation in the first four to eight tubes of the series, with changes of color in most of the remaining ones, as, for example. 5555542100, and constituting the "paretic curve" of Miller and 3. The cerebrospinal fluid in tabes dorsalis usually produces the "luetic zone" curve of a No. 4 intensity, as, for example, 4445542000; precipitation being partial in the first two or three tubes, then becoming complete, and gradually returning to normal through the balance of the series. The changes, however, are not constant or characteristic. 4. The fluids in cerebrospinal syphilis usually yield weak reactions of the "luetic zone" type. In tertiary syphilis without symptoms referable to the central nervous system similar reactions are frequently observed. 5. Fluids from cases of purulent or tuberculous meningitis may give reactions which are usually maximal in the higher dilutions, the "meningitic zone" type and so-called "Verschiebung nach oben." In acute anterior poliomyelitis the cerebrospinal fluid frequently yields reactions similar to the "luetic" and "meningitic" zone types of reactions. Practical Value of the Colloidal Gold Test.— The reports of a very large number of investigators, including Lange,2 de Cruris and Frank,3 de Cruris and Eberhardt,4 Grulee and Moody,5 Eicke, Jaeger6 and Goldstein,7 Klienberger,8 Zaloziecki,9 Kaplan,10 Miller and Levy,11 Swalm and Mann,1 Lee and Hiriton,2 Weston, Darling and Newcomb,3 Solomon and Welles,4 Miller, Brush, Hammers and Felton5, and others, show that under proper conditions the colloidal gold test is highly specific and of value in the diagnosis of general paresis. luetic person may be the first sign of an incipient paresis. A paretic reaction with the cerebrospinal fluid of a luetic individual should be regarded as of grave import; while positive symptoms of paresis may not be present, intensive antiluetic treatment may serve to arrest the disease. The colloidal gold reactions in tabes dorsalis and cerebrospinal syphilis are not characteristic of these diseases, and at most may yield the luetic zone type of reaction, and thereby prove of value in confirming a doubtful diagnosis. Principle. — This reaction is based upon the observation made by Weichardt6 in 1908; he found that diffusion is accelerated when differently colored solutions of antigen and its specific antibody are brought together. Changes in diffusion are associated with changes in the surface tension, both of which depend on a change in the osmotic pressure. This is the principle made use of by Ascoli in his miostagmin reaction, which will be described further on. Later Weichardt made the reaction more accessible to practical use by introducing into the solution of serums and antigen a system composed of sulphuric acid and barium hydroxid, together with certain catalytic agents. Using phenolphthalein as an indicator, he could show that fresh serums in high dilutions alter the surface tension of the finely divided barium sulphate particles by their colloidal action, so as to increase the absorption of H-ions, thus rendering the solution more alkaline. This phenomenon has been utilized by Weichardt, under the name of "epiphanin reaction," to determine the occurrence of such interaction of antigen and antibody. The reaction probably depends upon physicochemical principles of absorption, but the exact nature of the generalizations : 1. Solutions containing colloids — i. e., antigen alone, antiserum alone, or antigen plus non-specific antiserum in certain dilutions — act in the foregoing system by shifting the phenolphthalein end-point (the point of neutralization when acid and alkali are brought together in the presence of this indicator) in the sense of increased OH-ions (pink color) . 2. Specific antigens can inhibit the activity of their specific antiserums, the specific , antigen-antibody combination then becoming evident in vitro by a shift of the end-point in the sense of increased H-ion concentration (light color). Specificity. — The specificity of the reaction has been confirmed by a number of investigators who used the test for the identification of a host of antigen-antibody combinations in vitro. The underlying principles have been confirmed by Kraus and Amiradzibi,1 Schroen,2 Seifert,3 Mosbacher,4 and others. The reaction has been applied to a study of various antigens and their antibodies, such as diphtheria toxin, tetanus toxin, typhoid and tubercle bacilli, tumor extracts and placenta extracts by Weichardt; extracts of sjrphilitic livers and serums of syphilitic patients by Seifert, Keidel and Hurwitz.5 Technic. — The technic of this reaction has been modified from time to time. The method here given is essentially the latest given by Weichardt,6 slightly modified by Keidel and Hurwitz. Five constituents enter into the test: 1. The Antigen. — This is an alcoholic extract of syphilitic liver, prepared in exactly the same manner as for performing the Wassermann reaction. High dilutions of the antigen, ranging from 1 : 100 to 1 : 10,000, are prepared with normal salt solution. As in the Wassermann reaction, not every antigen is satisfactory, a point that can be determined only by making preliminary tests. 2. The patient's serum should be fresh, unheated, and highly diluted, the dilutions ranging from 1 : 100 to 1 : 10,000,000. Usually it is better to use higher than lower dilutions. When too concentrated solutions of serums and of antigen are used, erroneous results are likely to be obtained. 4. A saturated solution of barium hydroxid made equivalent to the normal solution of sulphuric acid. In the use of the barium hydroxid it is imperative to prevent its exposure to the air. A solution that has become cloudy, owing to the entrance of carbon dioxid, should not be used. In carrying out the test it is best to pour out the amount of barium hydroxid needed for the test into a rubber-stoppered bottle or test-tube, so as not to contaminate the stock solution. 5. A 1 per cent, alcoholic solution of phenolphthalein containing 1 per cent, of a 10 per cent, solution of strontium chlorid. The strontium chlorid has been found to catalyze the reaction. The Test. — The test is conducted as follows: A number of clean beakers of about 50 c.c. capacity are used. For each dilution of the serum a separate beaker is required. One beaker is used for an antigen control, and another to control the system of barium hydroxid and sulphuric acid. Five beakers may be used, Nos. 1, 2, and 3 constituting the main test, No. 4 the antigen control, and No. 5 the system control. The reagents are added by means of overflow pipets. To each of the first four beakers is added 1 c.c. of the dilute antigen to be used in the test (about 1 : 10,000). To beaker 5 is added 1 c.c. of the salt solution used in making the dilutions of the antigen and the serums. Now 0.1 c.c. of the dilute serum to be tested is added to each of the first three beakers, each beaker, however, containing the same serum in a different dilution. To beaker 5 the same quantity of salt solution is added, but to beaker 4 — the antigen control — no serum or salt solution is added. To each of the five beakers the system of sulphuric acid and barium hydroxid and phenolphthalein is now added carefully. First, 2 c.c. of the normal suphuric acid solution are added to each; then 2 c.c. of the barium hydroxid, and finally 0.1 c.c. of the phenolphthalein strontium chlorid mixture. It will be seen that beaker 4 — the antigen control — contains all the constituents of the test-beakers 1 to 3 except serum. To make beaker 4 qualitatively as well as quantitatively equal to beakers 1 to 3, 0.1 c.c. of the dilute serum (the average of the dilutions of serum which are used in the test) is now added to beaker 4, the reaction having already taken place. The addition of the sulphuric acid and barium hydroxid requires great care. Since the reaction depends on small differences in acidity or alkalinity, it is obvious that slight errors will vitiate the results. For the acid and the alkali separate pipets are used. After emptying the inside of the pipet are removed by washing. These washings are later added to the beakers to which they belong. In filling the pipets. with acid or alkali, the latter should first be drawn up into the pipet at least once, and then emptied again before the pipet is finally filled for delivery into the next test-beaker. Only by careful attention to these points in the technic can reliable results be obtained. Reading the Results. — If beakers 1 to 3 contained the antiserum to the antigen used, a positive epiphanin reaction will be obtained, and if the barium hydroxid and sulphuric acid were previously carefully adjusted to each other, it will be found that beakers 1 to 3 will be lighter than the antigen control, beaker 4. The presence of a specific antigen-antibody combination has shifted the phenolphthalein end-point in the sense of increased H-ion concentration. The exact differences in the alkalinity between beakers 1 to 3 and beaker 4 can be quantitatively determined by titration with JQQ suphuric acid, and -the results expressed as a curve. If the antigen and antibody were not specific, the epiphanin reaction will be negative. Beakers 1 to 3 will be more alkaline than the antigen control, beaker 4, because, as previously pointed out, serums alone or antigen with non-specific serums shift the phenolphthalein end-point in the sense of increased OH-ion concentration. The results may be plotted as curves. The titration values in JQQ sulphuric acid are placed on the ordinates, and the serum dilutions on the abscissae. The positive values are plotted above the line and the negative values below the line. No reaction is regarded as positive unless it gives a titration value of at least 0.05 c.c. JQQ sulphuric acid. Values below 0.05 c.c. are easily within the limits of error. The following method, employed by Seifert, is much simpler, but is open to the error on account of using the antigen and serum in too concentrated a state. In a small test-tube place 0.1 c.c. of a 1 : 10 solution of the serum in normal salt solution, and add 0.1 c.c. of an alcoholic extract of syphilitic liver. To this slowly add 1 c.c. of decinormal sulphuric acid and 1 c.c. of a solution of barium hydroxid of the exact concentration needed to neutralize the sulphuric acid solution. On the addition of the drop of the phenolphthalein solution the fluid turns red when the serum is from a syphilitic, whereas no change in tint occurs with non-syphilitic serum. Practical Value. — The reaction appears to be of considerable value in the diagnosis of syphilis. With serums and antigen in proper dilutions, the results closely parallel those secured by the Wassermann reac- tion. Keidel and Kurwitz report positive reactions with luetic serums in about 75 per cent of their cases. The reaction was found highly specific in that syphilitic extracts gave negative reactions with serums of non-syphilitic persons and patients suffering from malignant disease. Extracts of normal fetal liver and beef heart gave negative reactions with serums of syphilitic persons. Positive reactions have also been found in malignant disease, as with the antigens of carcinoma and sarcoma. Keidel and Hurwitz obtained 16 positive reactions in a series of 24 serums of persons suffering with definite or suspected malignant disease. Burmeister did not find the reaction of value in cancer. The epiphanin reaction has also been used in the diagnosis of pregnancy, but sufficient work has not been done to render an expression as to its merits of value at this time. THE MIOSTAGMIN REACTION Among the very large number of immunity reactions employed in attempts to secure a diagnostic test for cancer, the "miostagmin reaction" of Ascoli and Izar1 is the only one thus far devised that claims the serious attention of the clinician. Principles. — This reaction is founded on the fact, noted by Ascoli, that by the mixing of an antigen and its corresponding antibody there results a reduction of the surface tension of the liquid containing these, which may be demonstrated by counting the number of drops of the fluid in a given volume (usually 1 c.c.), under constant conditions. Normal serum diluted with salt solution is first tested, and the number of drops found in a cubic centimeter determined with a specially devised instrument known as Traube's stalagmometer. The antigen is so diluted that when mixed with this normal serum it does not increase the number of drops more than one in a cubic centimeter. When properly diluted patient's serum and antigen are mixed, it may be found that the number of drops is increased from 2 to 8 in a cubic centimeter. This constitutes a positive reaction. The reaction is apparently due to the lowering of surface tension, so that more and smaller drops are found; hence the term "miostagmin" has been applied to the test, the word being devised from the Greek, meaning "small drop." The reaction is said to be sharply specific and very delicate, so that antigens diluted up to 1 : 100,000,000 or higher may be detected. The technic requires considerable practice and experience or erroneous results are quite likely to occur. The exact nature of the reaction is not known. The antigens are soluble in alcohol, but their nature is obscure. The antibody involved in the reaction is referred to as the miostagmin, but its relation to other antibodies is also unknown. It is probably a physicochemical or colloidal reaction, and for this reason it has been placed in this chapter. described by Ascoli is as follows: 1. Cut non-degenerated portions of malignant tumor (cancer or sarcoma) into small pieces and dry in vacuo or spread out in a thin layer on clean glass plates and keep at a temperature of 37° C. 2. Pulverize the dried substance and extract with pure methyl alcohol (in the proportion of 5 gm. to 25 c.c.) for twenty-four hours at 50° C. in closed vessels, and shake occasionally. 4. It is now necessary to titrate the antigen and to determine in what dilution it should be employed. Various dilutions of the antigen are made with distilled water, as, e. g.} 1 : 10, 1 : 25, 1 : 50, 1 : 100, 1 : 150, 1 : 200, etc. A fresh normal serum is diluted 1 : 20 with normal salt solution, and 9 c.c. of this are mixed with 1 c.c. of the various antigen dilution. Into another tube place 9 c.c. of the diluted serum and 1 c.c. of distilled water. All test-tubes, pipets, and other glassware used must be perfectly dry. The tubes are gently shaken and placed in an incubator at 37° C. for two hours. The drop number for each fluid is then estimated by Traube's stalagmometer. This instrument is merely a finely and elaborately graduated pipet with a central bulbous reservoir. The dropping end of the instrument ends in a flattened ground base, thus insuring uniformity in the size of the drops. The instrument is so graduated that a fraction of a drop can be estimated. That antigen is to be chosen that does not alter the drop number for normal serum by more than one drop in a cubic centimeter — the strongest dilution that fulfils this condition being chosen. The Test. — The patient's serum is diluted 1 : 20 with normal salt solution and its drop number determined. Then take two tubes, and into one place 9 c.c. of diluted serum plus 1 c.c. of antigen dilution; into the other place 9 c.c. of diluted serum plus 1 c.c. of distilled water. A third tube may be prepared, which should contain 9 c.c. of normal serum (1 : 20) plus 1 c.c. of the same antigen dilution. A fourth tube contains 9 c.c. of a known positive serum (1 : 20) from a case of cancer and 1 c.c. of the antigen dilution. All tubes should be carefully labeled, their drop numbers determined, and then placed in an incubator at 37° C. for two hours or in the waterbath at 50° C. for one hour. At the end of this time they are removed, allowed to cool, and the drop number of each is determined. The controls are first examined to show that the antigen has not undergone any change. Variations of the number above one and a half or two drops (as compared with the control containing distilled water instead of antigen) .are regarded as positive reactions. The increase in drops is seldom greater than eight. Positive Other Methods for Preparing Antigens. — Various methods for preparing antigen and conducting the test are to be found in the literature, and it is extremely difficult to arrive at a correct conclusion as to which is the best method for preparing antigen. Among these methods for the preparation of antigen other than those previously described are the following: 1. After securing the alcoholic extract described elsewhere evaporate it to dryness. Again extract in methyl alcohol and evaporate. Extract with warm ether, renewed several times during the course of twentyfour hours. Dry, and repeat the extraction several times until the alcohol remains colorless. Evaporate the alcoholic and ethereal extracts at 50° and 37° C. respectively. A yellowish-red, sticky mass results. Dissolve this in a large amount of water-free ether. Filter, and evaporate at room temperature until a slight powdery precipitate is deposited. This solution constitutes the stock antigen, which, however, may require still further concentration. 2. A synthetic cancer antigen may be prepared by grinding up 0.5 gram of lecithin (ovolecithin Merck, or lecithin Richter), and extract it with 50 c.c. of acetone for twenty-four hours at 50° C. Filter through Scheicher and Schull's filter-paper No. 590, until clear. Just before it is to be used it should be dilated with water in such amount that 1 c.c. will contain the largest amount that does not cause a marked reduction of surface tension in normal serum. As a rule, this dilution is between 1 : 50 and 1 : 100 (Kohler and Luger)1. 3. A syphilis antigen may be prepared by extracting 0.5 gram of dried and powdered syphilitic liver with 50 c.c. of absolute alcohol for two hours at 37° C. with frequent shaking. Filter, and concentrate to 10 c.c. 4. A bacterial antigen, as e. g., one of typhoid bacilli, may be prepared as follows : Wash off five forty-eight-hour agar cultures of typhoid bacilli with 5 c.c. of normal salt solution for each tube. Cover the emulsion with toluol, and shake vigorously for several hours. Place in an incubator at 37° Cf for forty-eight hours, and filter through a sterile Berkefeld filter. This filtrate may be used as antigen, or it may be used in preparing an alcoholic extract in the following manner: To the original aqueous filtrate add 50 c.c. of absolute alcohol. Allow the mixture to stand for one-half hour, shake, centrifugate, and then mix the sediment with 20 c.c. of absolute alcohol. Shake thoroughly once more, and again centrifugate. Combine the two extracts, and concentrate on the water-bath to about 20 c.c. Practical Value. — This test is quite delicate, and errors due to faulty technic are quite likely to creep in. Unless all precautions are rigidly observed, the results are worthless. Although an extensive literature has accumulated bearing evidence as to the value of the test as a diagnostic procedure, the method has not, however, come into general use. Ascoli and Izar especially have advocated the test in the diagnosis of cancer. In 100 cases of malignant tumors, they obtained 93 positive reactions; in 103 cases of other diseases they obtained only one positive reaction. Tedesko, Stabilini, Leitch, Kelling, and others have reported favorably upon the practical value of the test in the diagnosis of cancer. Burmeister2 has found that a negative reaction has some value in excluding cancer, and is of more value in arriving at a diagnosis than a positive reaction, i. e.} it has a higher negative than a positive value. The test has also been used in the diagnosis of typhoid fever, paratyphoid fever, syphilis, tuberculosis (positive only in active cases) echinococcus disease, etc. Obviously, other methods of diagnosis, such as the agglutination reaction and the Wassermann reaction, have superseded this test in practical diagnosis. The method possesses, however, considerable theoretic interest and is worthy of further investigation. ANAPHYLAXIS IT is generally believed that when an animal previously injected with an antigenic substance is subsequently reinjected with the same substance, the antibodies induced by the first injection are reenforced, and that a continuation of the process of immunization will eventually lead to a high degree of immunity. Under certain circumstances, however, this is not the case, because severe and even fatal symptoms, as well as other manifestations, may set in after the second injection, indicating that, instead of being immune, the animal is indeed hypersusceptible or hypersensitive to the affects of the antigenic substance. Similarly, it is a common observation that whereas certain infections, such as smallpox, scarlet fever, and measles, confer a state of immunity, others, as, for example, pneumonia, erysipelas, and influenza, not only are not followed by immunity, but, indeed, that a decreased resistance or predisposition to subsequent infection by the same microorganism may be induced. Before experimental investigation of this subject was undertaken, not a few observations were made and described by the early workers in the fields of bacteriology and immunity that correspond exactly with the phenomenon of hyper sensitiveness, as we understand it today, although the true explanation of their unexpected results was not suspected, and they were modestly ascribed to faulty technic, embolism, toxicity of the inoculum, etc. From this it followed that the discovery that the experimental injection of such ordinary innocuous substances as normal serum and milk may produce violent symptoms and death gave rise to much surprise and incredulity, since scientists had long been accustomed to regard the reaction of an animal to an injection as a process of immunization, or diminished sensitiveness, instead of one of increased sensitiveness. Here, as Besredka remarked, the rules of immunity are " standing on their heads." To this state of hypersensitiveness Richet, one of the earliest investigators in this field, applied the term " anaphylaxis," meaning "without protection." While it appears to be the exact antithesis of "immunity," which means "with resistance to infection," recent re- searches would tend to indicate that the two subjects are indeed closely related. An enormous amount of work has already been done on anaphylaxis, the subject being of the greatest importance, not only on account of its practical bearing on serum therapy, but because of its intimate relationship to the subjects of infection and immunity, and the new light that these studies may throw upon the nature and mechanism of these processes. Although the phenomena of anaphylaxis are now known to be due to the proteins, and while the symptoms and lesions of the condition are fairly well understood, the exact nature and mechanism involved in the process are not established, and the entire subject is fraught with so much interest as regards infection and immunity that it affords a fruitful field for further research. In this chapter will be presented the known facts regarding anaphylaxis and the theories that have been advanced in explanation of its nature and mechanism, the consideration of anaphylaxis in its practical application to medicine being left for the following chapter. Historic. — The first observation of anaphylaxis as it occurs in an infectious disease was probably made by Jenner in 1798. This investigator observed the sudden appearance of an "efflorescence of a palish red color" about the parts where variolous matter had been injected into a woman who had had cowpox thirty-one years before. In 1839 Magendi found that rabbits that had been injected with eggalbumin died after a repetition of the injection, a phenomenon strikingly similar to that observed sixty-five years later by Theobald Smith following injections of horse serum. This phenomenon was subsequently studied thoroughly by Rosenau and Anderson and Otto. While the effects of diphtheria and tetanus antitoxins were being studied, peculiar and apparently paradoxic results were occasionally observed during immunization of animals with the bacterial toxins. Thus in 1895 Brieger l reported the case of a goat that was highly immunized against tetanus and yet was subject to tetanus. In 1901 von Behring and Kitashima2 reported similar findings with diphtheria in horse immunized against that infection. At this time it was shown that the results could not be due to the cumulative effect of the toxin, and the explanation offered aimed to show that the process was purely histogenetic, and based upon the assumption that receptors attached to the body-cells had a closer affinity for toxin than the free (antitoxin) receptors in the blood-stream. At the present time toxin hypersusceptibility is held by some to be a true anaphylactic reaction brought about made later on in this chapter. Richet's Studies. — The fundamental observations upon which our present knowledge of anaphylaxis is based were made in 1898 by Hericourt and Richet.1 These observers found that repeated injections of eel serum into dogs gave rise to an increased susceptibility to this substance, instead of immunizing the dogs against the serum. These studies were continued by Richet 2 and his assistants with extracts of the tentacles of certain sea anemones. These studies showed that a second injection of the poison into dogs, given after an interval of several days, is followed by greater and more intense activity than marked the first injection. If the animal survives, however, the disease is conquered more readily after the second than after the first injection. As previously stated, Richet coined the word "anaphylaxis," meaning "without protection," and indicating that the first injection destroyed any natural resistance that the animal might possess against the poison (actionocongestin). From these studies he concluded that two different substances are contained in eel serum and in the tentacles of actiniens, one concerned in establishing an immunity, and the other in calling forth a hypersensitiveness; thus far, however, the separate existence of these two hypothetic substances has not been proved. Arthus Phenomenon. — In 1903 Arthus,3 at the instigation of Richet, showed that similar results may be obtained with non-toxic substances, like serum and milk. On injecting rabbits at definite intervals with normal horse serum, he found that the first two or three doses were absorbed, whereas subsequent injections, given subcutaneously, led to increasingly severe local reactions (Arthus phenomenon) . If the animals, however, were first injected subcutaneously and later intravenously, or intraperitoneally, serious symptoms of dyspnea, convulsions, and diarrhea, and even death resulted. Von Pirquet's Early Studies. — For a long time urticarial eruptions were occasionally observed to follow transfusion of blood from lambs and other lower animals to persons suffering from anemia and similar conditions. Soon after diphtheria antitoxin was discovered the medical 1 Compt. rend. Soc. de Biol., 1898, 53. 2 Compt. rend. Soc. de Biol., 1902, liv, 170; 1903, Iv, 246; 1904, Ivi, 302; 1905, Iviii, 112; 1907, Ixii, 358, 643; 1909, Ixvi, 763; 1909, Ixvi, 810; 1909, Ixvi, 1005. Ann. de 1'Inst. Pasteur, 1907, xxi, 497, 1908, xxii, 465. profession was shocked to learn of the sudden death of the healthy child of an eminent German professor following a prophylactic injection of the serum. In 1902 von Pirquet began the study of these clinical manifestations with a child in Escherich's clinic who, after receiving a second dose of horse serum ten days after the first, on the same day developed symptoms of fever and a rash. On the basis of this observation von Pirquet 1 reached the conclusion that the prevailing views regarding the length of the incubation period of an infectious disease could not be correct. He therefore propounded the theory that the organism concerned in the etiology of disease calls forth symptoms only when it has been altered by antibodies, the period of incubation representing the interval necessary for the formation of these antibodies. In conjunction with Schick, von Pirquet endeavored to study all infectious diseases from the same point of view, especially smallpox, measles, recurrent fever, streptococcus infections, and the reactions to cowpox virus, tuberculin, and mallein. Later these same observers2 studied the symptoms following injection and reinjection of horse serum, designating the train of symptoms "serum sickness." They emphasized that a single injection of serum may suffice to bring about the symptoms, and that this immediate reactivity possesses diagnostic value in so far as it enables us to decide whether a previous infection has occurred. How near the astute Jenner came to reaching the same conclusion is shown in the following abstract from his report in 1798: " It is remarkable that variolous matter, when the system is disposed to reject it, should excite inflammation on the part to which it is applied more speedily than when it produces the smallpox. Indeed, it becomes almost a criterion by which we can determine whether the infection will be received or not (italics ours). It seems as if a change, which endures through life, had been produced in the action, or disposition to action, in the vessels of the skin; and it is remarkable, too, that whether this change has been effected by the smallpox or the cowpox, that the disposition to sudden cuticular inflammation is the same on the application of variolous matter." Von Pirquet at this time proposed the term "allergy," from ergeia, reactivity, and allos, altered, meaning altered energy or a changed reactivity, as a clinical conception expressing a truth without binding 2 Wien. klin. Wochenschr., 1903, xvi, 758, 1244; 1905, xviii, 531. Die Serumkrankheit, Leipsic, Deuticke, 1905; Munch, med. Wochenschr., 1906, liii, 66. For a full bibliography on this subject of allergy up to 1910 see von Pirquet, Archiv. Int. Med., 1911, vii, 259 and 383. findings. Theobald Smith Phenomenon. — While von Pirquet was making these studies, great impetus was given the experimental study of anaphylaxis by the observation of Theobald Smith, who found that guineapigs that were used for standardizing the strength of diphtheria antitoxin after a second injection of serum frequently presented symptoms of a serious character, such as great restlessness, dyspnea, itching of the skin, and violent convulsive seizures. In fully 50 per cent of the animals death occurred within half an hour. Simultaneously Rosenau and Anderson1 in this country and Otto2 in Germany undertook the study of this phenomenon. The first-named investigators showed most conclusively, by a thorough series of experiments, the action of horse serum and other substances in guinea-pigs, and proved that serum sickness was due to some constituent of the serum independent of the antitoxic antibodies, as normal horse serum yielded exactly similar results. Among the earlier studies of anaphylaxis of importance were those of Weichardt.3 These were made with extracts of placental cells, and later with the proteins of pollen, in relation to hay-fever. Wolff-Eisner4 wrote a treatise that had as its fundamental idea the belief that hypersensibility was due to endotoxins liberated by a lysin formed as a result of the first injection. Also among the earliest and most valuable studies upon the nature of anaphylaxis, and showing the important relation of proteins to the process, are those of Vaughan5 and his coworkers; indeed the studies of Smith, Rosenau and Anderson, Vaughan and Wheeler, Gay and Southard, Auer and Lewis, and others have gained for America a prominent part in the development of this important subject. Definition. — By anaphylaxis, in the limited meaning of the term, as, e. g., in that following the injection of horse serum in man or following the experimental administration of practically any protein in the lower animals, is understood the following train of phenomena. When a foreign protein is introduced into the animal body, usually parenterally, 1 Bull. 29, Hyg. Lab., U. S. P. H. and M. H. S., 1906; Bull. 36, Hyg. Lab., April, 1907; Jour. Infect. Dis., 1907, iv, 552; Bull. 45, Hyg. Lab., June, 1908; Bull. 50, Hyg. Lab., 1909; Jour. Amer. Med. Assoc., 1906, xlvii, 1007; Archiv. Int. Med., 1909, iii, 519. after a time a specific hypersensitiveness of the animal for this protein will appear. After a definite interval, a second injection of the same substance, harmless in itself, may produce an itching rash and fever or violent symptoms of illness, and rapid death may even occur in an animal so inoculated. In other words, the first injection of the protein (serum, milk, egg-albumen, etc.) produces no symptoms, but serves to alter the power of reaction on the part of the body cells by rendering them unusually sensitive or susceptible to the same or to closely related foreign protein. Therefore, as defined by Rosenau, anaphylaxis may be considered as "a condition of unusual or exaggerated susceptibility of the organism to foreign proteins." Terminology. — As previously stated, the word "anaphylaxis "(ana, against, and phylax, guard, or phylaxis, protection) was given to the condition by Richet, because he considered it one " without protection," or a state just the opposite to immunity, or prophylaxis. In the sense in which the phenomenon is now regarded the word is a misnomer, for we look upon the condition of hypersusceptibility as a step toward the attainment of a state of immunity, and as a distinct benefit and advantage to the organism. The term " allergy," introduced by von Pirquet, is more appropriate, as it expresses the condition of the bodycells, i. e.} their hypersensitiveness or altered reactivity, regardless of any theories we may entertain as to the manner in which this change is brought about or manifested. The word anaphylaxis has, however, come into general use, and with this explanation, we may continue to so use it. The term anaphylactogen is applied to the protein, as serum, milk, egg-albumen, etc., which sensitizes the body-cells; sentizer is also a good word, and the process of rendering body-cells hypersensitive by administering a foreign protein has been called sensitization. In von Pirquet's nomenclature the protein would be called an allergen. The term anaphylatoxin is applied to the toxic substance believed to be formed at the time of reinjection of the protein, and is regarded as responsible for the lesions and symptoms of anaphylaxis. In the belief that anaphylaxis resembles an intoxication, the second inoculation of protein is frequently spoken of as the intoxicating dose. PHENOMENA OF ANAPHYLAXIS The essential symptoms and lesions of anaphylaxis vary in the different animals, and, indeed, they have been found to vary among animals of the same species under different experimental conditions. Man. — When it is remembered that anaphylaxis and immunity are closely interwoven, and that anaphylaxis may be but a step toward securing prophylaxis and immunity, it will readily be understood that under the varying conditions of different injections the phenomena may be quite dissimilar. One of the best known examples of a general anaphylactic phenomenon in man is that following the injection of a foreign serum, as, e. g., horse serum (diphtheria antitoxin), which is characterized by an itching urticarial eruption, fever, and joint pains, and which is commonly known as "serum sickness." Fortunately, the severer and fatal forms of anaphylaxis in man are extremely rare, most cases having occurred in persons known to be hypersensitive to horse protein or in those suffering from the condition known as status lymphaticus. Familiar local anaphylactic reactions are the tuberculin, mallein, and luetin reactions. With this brief statement we shall pass to a consideration of anaphylaxis in the lower animals, experimentation having given us some insight into the mechanism of the process. Anaphylaxis in man and the relation it bears to immunity and disease, will be discussed again in Chapter XXVIII. Guinea-pig. — This animal gives the most constant and the most intense symptoms. According to Doerrr, guinea-pigs are four hundred times as sensitive an anaphylactic reagent as the rabbit. Horse serum, when injected into normal guinea-pigs, gives rise to no symptoms. As much as 20 c.c. may be injected into the peritoneal cavity, and small amounts may even be injected into the brain without causing any untoward symptoms. When a small dose of serum is injected intravenously, intraperitoneally, or subcutaneously, and ten days later a second injection is made, the animal develops symptoms of acute anaphylactic asphyxia, which, in the majority of instances, terminates fatally. This stage of exhilaration is soon followed by one of paresis or complete paralysis, with arrest of breathing. The pig is unable to stand, or if it attempts to move, falls upon its side; when taken up it is limp; spasmodic, jerky and convulsive movements now supervene. This chain of symptoms is very characteristic, although they do not always follow in the order given. Pigs in the state of complete paralysis may fully recover, but usually convulsions appear, and are almost invariably a forerunner of death. Symptoms appear about ten minutes after the injection has been given; occasionally in pigs not very susceptible they are delayed thirty to forty-five minutes. Animals developing late symptoms are not very susceptible and do not die. Death usually occurs within an hour, and frequently in less than thirty minutes. If the second injection be made directly into the brain or circulation, the symptoms are manifested with explosive violence, the animal frequently dying within two or three minutes" (Rosenau). H. Pfeiffer has shown that a depression of the temperature is a constant finding in the severer forms of anaphylaxis in the guinea-pig. In fatal cases this decrease may be as much as from 7° to 13° C. Some relation exists between the extent and the duration of the fall of temperature and the severity of the symptoms. During acute anaphylaxis the blood shows a leukopenia, — a diminution in complement, — and, as shown by Friedberger,1 a delay in or a loss of coagulability. The most striking change observed after death is permanent distention of the lungs, resembling emphysema, described by Gay and Southard, and particularly by Auer and Lewis.2 The lungs do not collapse, but remain fully distended, forming a cast of the pleural cavities. The alveoli are distended, and in some instances the walls may be ruptured. The walls of the secondary and tertiary bronchi are contracted, with infoldings of the normally thick mucosa, due to contraction of the smooth muscle by peripheral action, death really resulting from inspiratory immobilization of the lungs. The heart continues to beat long after respiration has ceased. Rosenau3 and Gay and Southard4 have also described minute hemorrhages in various organs and mucous membranes. The amount of serum necessary to sensitize a guinea-pig is surprisingly small. Rosenau and Anderson found one guinea-pig that was sensitized by 0.000,001 c.c. As a rule they used less than 0.004 c.c. in their experiments. Besredka places the minimum amount necessary to secure uniform results at 0.001 c.c., whereas 0.0001 c.c. proved sufficient in a considerable percentage of animals. The sensitizing dose of horse serum ordinarily employed in experiments upon guinea-pigs is 0.01 c.c. ; amounts ranging from 0.001 c.c. to 1 c.c. are ordinarily followed by an incubation period of from ten to sixteen days. Large doses also sensitize, but a longer incubation period is required. In order to produce a fatal result, the second or intoxicating dose must be considerably larger than the minimum sensitizing dose, the proportion between the two having been placed by Doerr and Russ as 1 : 1000, i. e.} if 0.001 c.c. of serum is injected intraperitoneally in order to effect sensitization, 1 c.c. injected by the same route ten or twelve days later would in all probability kill a half -grown guinea-pig, whereas 0.1 c.c. subcutaneously would be followed by serious symptoms. Rabbit. — Reference has been made elsewhere to the pioneer work of Arthus, who first described the local anaphylactic reaction about the site of subcutaneous injection. He also described objectively the most important symptoms of acute anaphylactic death in the rabbit, as well as the more ordinary type, which ends in recovery. In acute and fatal anaphylactic shock in the rabbit Auer 1 found slow respiration, weak or absent heart action, with fall in blood-pressure, general prostration, the sudden falling of the animal on its side, a short clonic convulsion, increased peristalsis, and expulsion in feces and urine. Death is ascribed to a vascular or cardiac shock or to a failure of the heart action of peripheral origin, mostly affecting the right side, and due to a form of chemical vigor. The muscle may be gray, stiff, very tough to the finger-nail, and non-irritable. Further evidence of the importance of heart failure in anaphylaxis in the rabbit is furnished by the electrocardiographic study of Auer and Robinson.2 Blood coagulability is delayed. Rabbits are by no means so easily sensitized nor to so high a degree as guinea-pigs. Non-fatal anaphylaxis accompanied by fall in bloodpressure, increased heart-rate, and active intestinal peristalsis is readily produced, but there is considerable uncertainty in inducing acute anaphylactic death. Sensitization is usually effected by two or three intravenous injections of 1 c.c. of serum at intervals of three days. Intoxication generally follows an intravenous injection of 1 to 5 c.c. of serum about four to six weeks later. Much smaller doses than these may, however, be used, as was occasionally shown during immunization of rabbits with erythrocytes for the production of hemolytic amboceptor, when minute traces of serum, escaping the washing process, served to sensitize, and at a later injection produced acute anaphylactic shock and death within a very few minutes. Cats. — Anaphylaxis in the cat has been studied especially by Schultz,3 who observed that cardiac disturbances followed. Horse serum, however, was found markedly toxic in effect, even in the un- and in the sensitized animals. Dogs. — In these animals the most constant symptom of anaphylaxis is an initial and transitory rise in blood-pressure, followed by a prompt fall of from 80 to 100 mm. of mercury. This was first described by Biedl and Kraus,1 and subsequently by Eisenbrey and Pearce,2 Robinson and Auer.3 The general symptoms are not so violent as are those that occur in the guinea-pig and death is infrequent. Following intravenous injection of the intoxicating dose of serum there may be great restlessness, marked prostration, and vomiting, tenesmus, and involuntary discharge of feces and urine. . If death does not occur, a condition of hemorrhagic inflammation in both the large and the small intestine may develop, called by Richet " chronic anaphylaxis, " and by Schittenhelm and Weichardt, "enteritis anaphylactica. " Robinson and Auer, by an electrocardiographic study, detected cardiac changes consisting of disturbance of the heart impulses, abnormalities in ventricular contractions, and other interferences with the mechanism of the heart, due probably to the effect of horse serum on the peripheral cardiac tissue, and independent of the drop in blood-pressure or any effect upon the central nervous system. The heart changes do not appear to exert a primary influence on the blood-pressure, which is due to an effect upon the splanchnics, and is probably a secondary factor in anaphylaxis or vascular shock of the dog. In many instances there is leukopenia, with loss of mononuclear cells. Coagulation of the blood is delayed, a condition first described by Biedl and Kraus,4 who believed it to be due, probably, to a decrease in thromboplastin or an excess of antithrombin. Pepper and Krumbharr5 have shown that, by adding small amounts of thromboplastin to the non-coagulating, post-anaphylactic, oxalated plasma, the coagulability of the blood will be restored. As stated elsewhere, it may be difficult to produce anaphylaxis in a dog. Usually a subcutaneous injection of 10 c.c. of horse serum, followed in from three to six weeks by 5 c.c. intravenously, will at least cause a marked fall in blood-pressure or fatal anaphylaxis. MECHANISM OF ANAPHYLAXIS ,577 to horse serum, as was shown by Schultz and Jordan. This reaction is evidenced by restlessness, marked irritability of the skin, involuntary passage of urine and feces, and temperature and blood-pressure changes. Anaphylactic reactions have also been observed to occur in numerous other animals, e. g., in cows, sheep, horses, hens, pigeons, and in certain cold-blooded animals, the symptoms varying according to the species. These reactions have not as yet been carefully studied. Whereas the lesions and symptoms of anaphylactic shock here described in different species of animals are those commonly observed with serum proteins, they vary in no essential when any protein agent is used when the conditions of dosage and administration are the same. It is evident, however, that no one symptom, or group of symptoms, can be regarded as characteristic of anaphylaxis in all animals. The various species present widely differing pictures with the same protein substance, and these differences are best explained on the ground of changes in the anatomic structure and physiologic reaction of different animals. Thus, Schultz has shown that serum anaphylaxis is essentially a matter of hypersensitization of smooth muscle in general, and that, during anaphylactic shock, all smooth muscle contracts. In the guineapig this effect is most evident in the bronchi, owing to the peculiar, though normal, anatomic structure of the mucosa, which is relatively thick as compared with the lumen, so that contraction of the smooth muscle throws it into folds that completely occlude the bronchi causing death from inspiratory asphyxia. The bronchial mucosa of dogs, rabbits, and rats, however, is relatively thin and poor in smooth muscle tissue, which may account for an entire absence of transitory respiratory difficulties during anaphylactic shock in these animals. In the dog the most marked effect is apparent upon the smooth muscle of the gastrointestinal tract, contraction resulting in setting up vigorous intestinal peristalsis, vomiting, and involuntary emptying of the urinary bladder. The characteristic initial rise in blood-pressure may be due to constriction of the splanchnic, pulmonary, coronary, and systemic arteries, followed by a condition of paresis and a fall in blood-pressure. The cardiac muscle is also involved, particularly on the right side, as shown by Robinson and Auer, and this favors a venous accumulation of blood. In the rabbit a similar effect is noted upon the smooth muscle of the blood-vessels, and particularly on the heart, as well as upon the gastro- intestinal tract. Our present knowledge would ascribe these effects, therefore, to a local or peripheral action of the protein upon smooth muscle, and not primarily on the central nervous tissues, as was originally believed. The fall in blood-pressure, therefore, appears to be a most constant and primary factor. So far as I am aware, no blood-pressure studies on the anaphylactic guinea-pig have been made. In this animal the heart continues to beat after respiration ceases, but this phenomenon may be due to mechanical and other factors dependent upon the extreme pulmonary emphysema. Fall in blood-pressure and congestion of the splanchnic area may produce cerebral anemia, and be responsible in some measure for the respiratory disturbances, the retching, the involuntary expulsion of urine and feces, the great depression and muscular weakness, and the speedy recovery when death does not result. In man the marked urticarial and other rashes and the inspiratory asthma of those peculiarly sensitive to a protein due to a narrowing of the bronchi, the latter being analogous to the condition observed in the guinea-pig, the diarrhea, and the secondary drop in blood-pressure, all indicate a similar action on smooth muscle. This also provides an adequate pharmacologic explanation of the action of atropin, sedatives, and anesthetics in alleviating or masking the symptoms of acute anaphylaxis. (See Chapter XXVIII.) Aside from the severe fall in blood-pressure and temperature, other effects of anaphylaxis are leukopenia, local and general eosinophilia (Vaughan,1 Moschowitz,2 Schlecht and Schwenket3), and reduced coagulability of the blood. Pfeiffer4 found 'poisonous substances in the urine during anaphylactic intoxication, and Hirschfeld5 detected a pressor substance in the serum of intoxicated guinea-pigs. A more critical study of the nature and varieties of anaphylactogens, or substances capable of producing anaphylactic sensitization, will now be made. This will include also a consideration of the nature of the substances directly responsible for the anaphylactic intoxication, commonly known as anaphylactotoxins, and of the question as to whether anaphylactic intoxication is the result of an interaction in the bloodstream (humoral) or in the cells (histogenetic) or in both. 2 New York Med. Jour., January 7, 1911. a Arch. exp. Path. u. Pharm., 1912, 68, 163. 4 Zeitschr. f. Immunitatsf., 1911, 10, 550. s Zeitschr. f. Immunitatsf., 1912, 14, 466. ANAPHYLACTOGENS, OR ALLERGENS So far as is now known, only proteins may become anaphylactogens, and with the exception of gelatin and a few other proteins, practically any soluble protein will produce sensitization and intoxication of susceptible animals. Bacterial substances, extracts of plant tissues, purified vegetable proteins, and proteins derived from invertebrates and cold-blooded vertebrates have all been found capable of acting as anaphylactogens when introduced in a soluble and unaltered condition into an animal. The proteins concerned must be foreign to the circulating blood of the injected animal, but they may be tissue proteins of the same animal — e. g., syncytial cells — that are not normally present in the blood. Indeed, Uhlenhuth and Haendel1 claimed to have sensitized a guinea-pig with the dissolved lens of one eye so that it reacted to a subsequent injection of the lens of the other eye. Proteins in solution are more active than those in suspension or in partial solution, and in general tissue proteins are less active than proteins in the blood, lymph, and secretions, but even keratins may produce anaphylaxis when dissolved (Krusins2), Uhlenhuth3 has obtained positive results with proteins from mummies. As previously stated, the altered protein of an animal may be reinjected again into the animal and induce an anaphylactic reaction. Recently Richet4 has directed attention to this phenomenon, which he calls "indirect anaphylaxis," through observing an intense leukocytosis in a dog which reached the maximum on the eighth day following a second chloroformization. Non-protein Anaphylactogens. — As with other immunologic reactions, observations have been made that are interpreted as indicating that non-protein substances are capable of producing anaphylaxis; thus Pick and Yamanouchi5 sought to demonstrate the antigenic properties of alcohol-soluble constituents of horse and beef serum, but conservatively concluded that their results may have been due to a combined action of protein and fat combinations. Similar conclusions were also drawn by Uhlenhuth and Haendel6 in their study of animal and vegetable oils and fats. Bogomolex1 is less conservative, and believes that he has succeeded in producing lipoid anaphylaxis; these claims, however, could not be confirmed by Thiele and Embleton.2 Meyer3 was able to sensitize pigs with pure lipoids extracted from tape-worms, but was unable to intoxicate them with the same extracts, results that may be understood, since White and Avery4 have shown that as little as 0.0001 milligram of edestin will serve to sensitize a pig, whereas larger amounts of protein — more than is contained in Meyer's preparations— are necessary to produce intoxication. Finally, the studies of Wilson5 and White6 leave no doubt as to the fact that pure lipoids cannot produce anaphylaxis. It is possible, however, for non-protein substances to combine with or alter the proteins of an animal and thus cause anaphylaxis. In this way can be explained apparent anaphylactic reactions to iron, salvarsan, iodin, arsenic compounds, and other medicinal agents. Chemistry of Protein Anaphylactogens. — The purest known proteins act as anaphylactogens or sensitizers; in fact, the purer the protein, the more thoroughly it sensitizes the animal and the smaller is the dose necessary to produce intoxication. The crystallized proteins of hemoglobin, egg-albumen, and such pure vegetable proteins as edestin and excelsin, are powerful sensitizers. According to Wells,7 nothing less than an entire protein molecule will suffice to produce anaphylaxis, although Zunz 8 claims to have observed typical reactions with the proteoses of fibrin, and Abderhalden9 obtained one with a synthetic polypeptid. It is not necessary, however, for a protein, in order to be active, to contain all the known amino-acids of proteins, for certain vegetable proteins, e. g., hordein and gliadin, which lack one or more amino-acids, such as glycocoll or tryptophane, may produce typical reactions. Presumably, the inability of pseudoproteins, such as gelatin, to act as anaphylactogens depends upon their deficiency in aromatic radicals. While, therefore, it is probable, although it has not been definitely proved, that nothing less than the entire protein molecule is capable of producing the typical reaction, the questions arise whether the whole molecule, or only a certain group thereof, determines the specificity, and whether the whole molecule, or only a portion, is concerned as the sensitizing agent. It is now generally accepted that both the sensitizing and the intoxicating agents are one and the same protein, and the older view, which held that in a mixed protein substance, such as blood-serum, corpuscles, egg-albumen, etc., one protein is present that sensitizes and another that intoxicates, is probably erroneous. Besredka, for instance, finds that when a protein used to produce intoxication is heated it is less likely to prove fatal, and he concludes that proteins contain a thermostabile sensitizing and a thermolabile intoxicating portion. Doerr and Russ, however, have shown by carefully conducted experiments that heat affects both properties of proteins to the same degree. Since pure proteins, as, e. g., highly purified edestin, which is believed to be a chemical unit, act as exquisite sensitizers and intoxicants, it seems reasonable to believe that the sensitizing and poisonous group are constituents of the same protein substance. Whether or not both sensitizing and intoxicating groups are contained in each single molecule of a pure protein is a question that cannot be answered until we can be certain that absolutely pure proteins are secured to start with, and until our methods of effecting its cleavage have been perfected. Vaughan and his coworkers have long maintained that a sensitizing non-poisonous and a nonsensitizing toxic portion are groups of the same molecule, which they are able to obtain in vitro from animal, bacterial, and vegetable proteins by a method of splitting with sodium hydroxid in absolute alcohol, as described in the chapter on Infection. The toxic intramolecular group is regarded as non-specific, and the same for all proteins, which explains the identity of the symptoms of anaphylactic shock whatever the protein by which it is induced. The non-toxic sensitizing group, however, is specific, although it may not itself be a protein, or at least a biuret body. Whether or not all proteins contain a sensitizing group has not been determined. In keeping with his theory of the role of the toxic moiety of a split protein molecule in the production of disease, Vaughan believes that when proteins are introduced parenterally into animals, the non-toxic portion stimulates the body-cells to elaborate specific ferments, constituting the phase of sensitization, so that when this protein is subsequently introduced, digestion rapidly takes place with the liberation of the toxic substance responsible for the characteristic symp- toms, which may terminate in death. This interesting and plausible theory will be referred to again. It has received further experimental support from the work of White and Avery1 with split edestin and split tubercle-cell substance;2 and from that of Zunz3 and Wells and Osborne,4 the last-named observers working with vegetable proteins, and concluding that although it is probable that the entire protein molecule is involved in the anaphylactic reaction, only certain groups are specifically concerned in the process. In other words, it would appear that anaphylaxis, — for example, serum anaphylaxis — is not due to one protein substance in the serum that sensitizes and another that intoxicates, both properties residing in the same protein molecule. Whether they are the same intramolecular substances existing side by side, — one the sensitizer and the other the intoxicator, — as is believed by Vaughan, cannot be definitely decided, although experimental work would tend to indicate that the latter may be the true explanation. Physical State of Anaphylactogens. — The results of experiments all tend to support the theory that proteins in solution are most powerful in producing anaphylaxis, because they are able to come into intimate contact with, body-cells, and cell permeation is probably necessary for the most complete sensitization. This explains in part the conflicting statements concerning the effect of heat on the sensitizing properties of blood-serum. Rosenau and Anderson found that animals could not be sensitized with serum that has been heated at 100° C., whereas Doerr and Russ placed the point at 80° C. Besredka showed that the sensitizing properties are in part at least, dependent upon the physical condition of the protein, and that heating undiluted blood-serum coagulates the protein and leads to a decrease of its anaphylactogenic properties. Similarly, Vaughan found that proteins that were insoluble in water, as, for example, edestin, sensitize more readily when dissolved in salt solution. The same factors are operative with the protein used for intoxication, the physical state of the protein substance having a direct bearing on the rapidity with which shock is produced. An interesting question in this connection is whether sensitization and intoxication may occur with the parenteral introduction of protein as with the food. In the great majority of instances the gastro-intestinal enzymes so completely disrupt the protein molecule that sen- sitization and intoxication do not occur. Guinea-pigs have, however, been sensitized by feeding them meat or serum, and instances of buckwheat, fish, and egg idiosyncrasies would tend to indicate that intoxication may result from the ingestion of these substances in sensitive persons. Rosenau and Amos1 have demonstrated that proteins in a volatile state, as in the exhaled breath of men, when condensed and injected into guinea-pigs will sensitize these animals to subsequent injections of human serum. While it is doubtful if the complex molecule possesses the power of passing into the air in a gaseous form, it may probably exist in colloidal solution. Rosenau was also able, by keeping guinea-pigs in stables together with horses, to sensitize them to horse serum. These experiments are of fundamental importance in explaining instances of human anaphylactic phenomena among those sensitive to horse protein, — as, e. g., persons seized with sneezing and asthma when they come near horses, — and also tend to show how minute may be the quantity of protein capable of sensitizing and intoxicating body-cells. Bacterial Anaphylactogens. — All bacterial proteins .are anaphylactogens, although, on account of the physical state of the bacteria, they yield reactions more irregular and weaker than those observed with proteins in solution. The tuberculin, luetin, mallein, and similar reactions are true anaphylactic phenomena. Rosenau and Anderson, Vaughan and Wheeler, Kraus, and others have observed anaphylactic reactions with various bacteria, such as Bacillus subtilis and colon, typhoid, anthrax, and tubercle bacilli. Not infrequently reactions occur during the therapeutic administration of tuberculin and bacterial vaccines. This brings up the interesting question as to whether toxins are anaphylactogens, a subject previously mentioned in the historic review of this subject. Instances of hypersensitiveness to diphtheria and tetanus toxins were early observed in attempts to immunize horses in the production of antitoxins. As it is extremely difficult, if not impossible, to isolate a toxin free from other constituents of the medium into which it was excreted by microorganisms, this question cannot be answered in a definite manner. There is no direct proof, however, that toxins sensitize, although the protein in the toxin filtrate may serve to do so. In 1902 Vaughan and Gelston2 showed that the poison contained in the cellular substance of the diphtheria bacillus is an entirely different one from the toxin elaborated by the same microorganism, results that were confirmed in 1911 by Friedberger and Reiter,1 working with the dysentery bacillus. Thus hypersensitiveness to toxins is probably not an anaphylactic phenomenon, but is due to a greater affinity of the bodycells for the toxin. This explains the so-called paradox of Kretz, who found that while the injection of an accurately neutralized toxin-antitoxin mixture produces no bad results in a normal animal, in one that has been previously actively immunized with toxin, the reverse occurs. Apparently the sessile receptors have a stronger affinity for toxin than have the free receptors, and accordingly the toxin becomes dissociated and combines with the cells. This view is also substantiated by the observation that the symptoms of intoxication caused by the toxin used for immunization are not those of anaphylaxis, which, for a certain animal, are the same regardless of the source of the protein. Toxin hypersensitiveness does not seem to be transmissible to normal animals, whereas in anaphylaxis the condition may be transmitted (passive anaphylaxis). Whether or not endotoxins act as anaphylactogens cannot be definitely stated. If they do, their action and effects are intimately connected with those ascribed to the protein contained in the bacterial cell. It is unlikely, however, that they play any role in inducing hypersusceptibility, as their toxicity is usually apparent soon after injection, and before sensitization has occurred. The necessary period of incubation between sensitization and intoxication, the symptoms, and the fact that in some cases an immunity is induced, are results that strengthen the belief that the phenomenon of hypersensitiveness has a practical significance in the prevention and cure of certain infectious diseases. THE HUMORAL OR ANAPHYLATOXIN THEORIES OF ANAPHYLAXIS The symptoms of anaphylaxis that follow injection of the protein into an animal previously sensitized with the same protein have been ascribed to the effects of a poison as the etiologic factor, although as yet this poison has not been isolated in a pure state. The Anaphylatoxin or Protein Poison. — Vaughan and Wheeler were the first to demonstrate a poison in vitro by splitting proteins with a solution of NaOH in absolute alcohol. Friedmann was first to produce it in vitro through the action of ferments contained in immune and normal rabbit serum upon ox corpuscles and serum precipitates. 1 Zeitschr. f. Immunitatsf., 1911, 11, 493. Weichardt also produced it by digesting placental protein with the serum of rabbits immunized with placental cells. At the time he regarded it as a true toxin, similar to diphtheria and tetanus toxins, but at present we know that this poison is not a true toxin, because it cannot produce an antitoxin, is thermostabile in acid solution, and is not a single specific substance, but a mixture of more or less closely related substances in the nature of protein cleavage products, as first shown by Vaughan and Wheeler, and since accepted by Friedberger himself and a number of other investigators. In a strict sense, therefore, this term is a misnomer, but it is in such general use that it need not be discarded if we have a clear understanding that the sum total of independent researches by numerous investigators shows that it is not a true toxin, as tetanus toxin, for instance, but a protein poison. As the symptoms of anaphylaxis are always the same in the same animal, no matter what protein is used, it would appear that the protein poison is either always the same or composed of a group of very closely allied products, and, indeed, this seems to have been proved by an extended series of researches with the most diverse proteins of animal, bacterial, and vegetable origin. It may be stated, therefore, that anaphylatoxins may be regarded as protein poisons composed of protein cleavage products, and that these are responsible for the lesions and symptoms of anaphylaxis. There is some difference of opinion regarding the source of the protein matrix and the mechanism of its cleavage with the production of the poison in anaphylaxis, and I shall consider this phase of the subject later. There is, however, a striking uniformity of experimental evidence and opinion regarding the role and primary importance of the protein cleavage poisons in the anaphylactic process. Briefly summarized, the evidence on this point is as follows : 1. As was just stated, the first to advance the theory regarding the role of protein-split products in anaphylaxis, as well as in infection and immunity in general, were Vaughan and Wheeler. In 1907 these observers showed that proteins may be split by boiling with alcoholic sodium hydroxid solution into two fractions — one non-toxic and alcohol soluble and the other toxic and alcohol insoluble. The toxic fraction, when injected into normal guinea-pigs in doses of from 8 to 100 mg., 1 Zeitschr. f. Immunitatsf., 1910, 4, 636. kills the animals, death being preceded by all the symptoms of acute anaphylactic intoxication. This toxic moiety has been obtained by this method from the most diverse proteins, and seems to be the same for all, the specificity residing in the non-toxic attached group. This and other observations led Vaughan and his collaborators to formulate the hypothesis that the non-toxic and specific intramolecular group of a protein serves to stimulate the body-cells to produce specific proteolytic enzymes, and that upon the injection of a second dose of the same protein, these enzymes at once disintegrate it, setting free the toxic group that produces the lesions and symptoms of acute anaphylactic intoxication. This protein cleavage in vivo is entirely analogous to the cleavage process occurring in vitro with the alcoholic sodium hydroxid solution, and the poison in both instances is regarded as the same. 2. Mention has previously been made of the protein poison obtained by' Friedmann by digesting ox corpuscles with immune and normal rabbit serum, and by Weichardt as the result of the digestion of placental protein with immune rabbit serum. In 1910 Friedberger,1 by digesting a serum precipitate with normal guinea-pig serum, obtained a similar toxic substance; by means of ferments he secured a protein cleavage poison that, when injected into normal guinea-pigs, produced the symptoms of acute anaphylaxis, the process being entirely analogous to that obtained by Vaughan and Wheeler by protein splitting with alcoholic sodium hydroxid solution. Subsequent studies by Friedberger and his collaborators 2 showed that similar protein poisons could be obtained by digesting microorganisms, as, e. g., Bacillus prodigiosus, Bacillus typhosus, and Bacillus tuberculosis, with normal guinea-pig serum. Friedberger and Nathan 3 obtained the poison by digesting normal horse serum with fresh guinea-pig serum; Bordet,4 by digesting agar with fresh serum; Dold and Aoki,5 by digesting meningococci, streptococci, pneumococci, gonococci, and various other microorganisms with fresh normal gunea-pig serum. As was expected, cleavage could be facilitated and hastened by using immune serum specific for any particular bacterial or other protein. These results indicate that fresh normal guinea-pig serum contains a normal thermolabile non-specific proteolytic ferment capable of splitting some, through probably not all, proteins, a view advanced by Vaughan many years previously. After sensitization, a specific proteolytic ferment is produced for the particular protein injected, the presence of the specific in addition to the normal ferments constituting the difference between normal and sensitized animals. Since these studies show that, when incubated with normal serum, bacteria and certain other proteins yield a soluble and active poison, the question naturally arises why this reaction does not occur when these proteins are first injected directly into the blood? Vaughan has answered this question by assuming that the ferment is in a more available form in the serum than it is in the blood, since the ferment is probably largely a leukoprotease mainly derived from the disintegration of leukocytes. Or it may be that the cleavage is carried on in the circulating blood beyond the point of the products constituting the protein poison, or that the inclusion of the foreign protein by the phagocytes may delay the disruption of the former. The Protein Matrix. — While there is this consensus of opinion among the adherents of the chemical or anaphylatoxin theory of anaphylaxis regarding the role of protein poison in the production of anaphylaxis, there is some diversity of opinion regarding the source of the protein matrix, i. e., whether the protein that is broken down is the protein injected or the protein of the person's own serum, especially in view of the fact that mixtures of kaolin and normal guinea-pig serum produce the poison in vitro. It has been suggested — (a) That the kaolin, agar, bacteria, etc., absorb the complement from the serum, and that this renders the serum poisonous; (6) that the poison is preformed in the serum, but that its action is neutralized by some other constituent of the serum that is absorbed; (c) that the absorption of some constituent of the serum leads to a, breaking-up of serum proteins, with liberation of the poison. The latter view, as shown by Jobling and Petersen, 1 appears to be the most plausible. These writers believe that the normal tryptic or proteolytic ferment of the blood is held in check by an antiferment of the nature of unsaturated fatty acids, and that laokin, bacteria, agar, etc., remove this antitryptic influence by absorbing the lipoidal antiferment, setting the ferment free, which then acts upon the serum protein, producing the toxic protein poison (sero toxin). While Vaughan, Friedberger, and their collaborators believe that the protein poison is derived from the injected protein, Jobling and Petersen believe that the matrix is, indeed, the protein of the animal's own serum. Doerr2 likewise regards it as highly improbable that the poison is generated by the bacteria or other foreign protein, but believes that it is derived from the serum through the absorption of inhibitory antibodies by the bacteria, precipitates, etc. There can be no doubt, however, of the high specificity of the anaphylactic reaction, which indicates that specific ferments are produced for the protein injected, and while the discussion cannot be considered closed, it would appear that, for the present, it would be best to accept the theory that anaphylaxis is due both to the cleavage of the injected anaphylactogen and the blood-serum by normal and specific proteolytic ferments. The Anaphylactin (Allergin) or Anaphylactic Antibody. — There is a diversity of opinion concerning the nature of the substance developed in the body under the influence of the anaphylactogen, which is capable of cleaving the latter and producing the anaphylactic poison. That such a body exists in the blood of the sensitized animal is shown by the production of passive anaphylaxis in normal animals by injecting into them a few cubic centimeters of blood or serum from a sensitized animal. The animal so sensitized becomes at once or within a few hours sensitive to the specific anaphylactogen, regardless of the species of animal furnishing the immune serum. Terminology. — Various names have been applied to this body. Vaughan objects to the term antibody, although this designation would seem to be appropriate if we consider that it is a reactionary product or antibody to the protein responsible for its production, although, instead of being protective to the animal, its host, it is just the reverse. Richet named it toxogen, because it is responsible for the production of a poison. Otto speaks of it as reaction body, Nicolle as an albuminolysin, Besredka as sensibiUsin, and von Pirquet as oiler gin. Nature of Anaphylactin. — A full discussion of the nature of this body, which is believed to cleave the anaphylactogen and set free the anaphylatoxin or protein poison, would involve a review of the entire subject of antibodies and immunity in general. Vaughan regards it as a ferment, evidently meaning that an amboceptor and a complement act together and produce lysis or disruption of the protein molecule. It is difficult, and indeed impossible, at this time to discuss with any degree of definiteness the propriety of regarding an immune and cytolytic amboceptor as a ferment, just as we regard trypsin as a ferment. If the ferments are to be considered as identical with amboceptors, then we must regard Abderhalden's protective ferments as cytolysins, but certainly, in the light of our present knowledge, we are hardly justified in drawing hard and fast lines. Therefore while I have confined the discussion of the protective ferments to a. separate chapter (Chapter XV) , and have not considered it under the general head of the cytolysins, it is to be remembered that the ferments possess many of the properties of lytic amboceptors, and they may be identical with them although apparently different owing to the application of chemical methods, especially by Abderhalden, in their study. Most observers regard the anaphylactic antibody, toxogen or allergin, as an amboceptor and a complement. The actual antibody then must be considered as an immune albuminolysin, for complement is present in normal serum, and is not necessarily increased during the process of sensitization. As in other lytic processes, however, complement or alexin is of great importance, constituting, as it does, the actual lytic agent, after the antigen, or, in this instance, the anaphylactogen of the second injection, has been sensitized by the amboceptor. Some observers believe that the complement is decreased during anaphylaxis, presumably being used up in effecting lysis of the protein. Friedmann claims that in allergy to red corpuscles there is a close parallelism between the anaphylactic bodies and the hemolytic amboceptor. With the more recent work of Abderhalden on protective ferments and the development of a dialysis and optical method of detecting the products of protein cleavage, it was hoped that the true and exact nature of anaphylaxis would finally be established. It would appear possible to determine the presence, in the blood-serum of sensitized animals, of specific proteolytic ferments capable of demonstrating their presence in vitro, and to show the products of protein cleavage just after anaphylactic shock and a corresponding decrease or total absence of the ferments as a result of their participation in the albuminolysis. Indeed, Abderhalden1 has recently claimed that all these conditions have been found to exist: (1) The serums from 12 guinea-pigs sensitized to eggalbumen, when mixed with antigen, showed digestive power by both optic and dialysis (biuret) methods; (2) similar serums, dialyzed alone, showed digestive products in only one of six serums tested : (3) the serum of six guinea-pigs taken at intervals of from five minutes, to one and onehalf hours after the second injection (egg-albumen) and dialyzed, gave negative results after from five and fifteen minutes, whereas four taken after thirty, forty-five, sixty, and ninety minutes respectively were positive. In each test the serum (10 c.c.) was dialyzed against distilled water for sixteen hours at 37° C., and the presence of the products of digestion determined by the biuret reaction. In this manner the final 1 Zeitschr. f. physiol. Chem., 1912, 82, 109. evidence of the role played by the protein split products in the production of acute anaphylaxis has apparently been furnished. These results however, cannot at the present time be regarded as final. Pearce and Williams, 1 in a similar study with horse serum, employing the dialysis technic and using ninhydrin as the indicator, were unable to demonstrate the presence of the ferments after sensitization, although by using large amounts of serum secured after anaphylactic shock had occurred they observed positive reactions, which may have been due, in part at least, to the presence of cleavage products. Zunz8 found that the proteinsplitting properties of blood-serum, as tested on the sensitizing protein, increased in the anaphylactic state from the fifth to the twentieth and sixtieth day, and were not recognizable in blood-serum taken during or soon after anaphylactic shock occurred. Pfeiffer and Mita and Vaughan have observed the apparent disappearance of the ferment from the blood, even though the animal is sensitized, and the last-named observer explains this on the assumption that the ferment comes from the fixed cells, which are stimulated to elaborate the ferment only when the specific protein is brought into contact with them. One of the older theories of anaphylaxis regards the process as a precipitin reaction. It is apparent that, in the serum of an animal immunized with a soluble protein, such as a serum, a precipitin and complement-fixing body, presumably an albuminolysin or so-called " ferment, " are produced, and exist together in the immune serum. While the role of precipitins themselves appear to have been excluded as directly participating in the production of anaphylactic shock, recent experiments of Zinsser and others would tend to show that a precipitin possesses the nature of a protein sensitizer or antibody that sensitizes its antigen, just as a hemolytic amboceptor sensitizes its corpuscles, precipitation being a secondary phenomenon due to the colloidal nature of the reacting bodies under conditions of quantitative proportions and environment that favor precipitation. This would assign to the precipitins and agglutinins an active though secondary role in the processes of anaphylaxis and immunity. At the present time, therefore, we may tentatively assume that the anaphylactin or allergin is of the nature of a specific lytic amboceptor or albuminolysin, which, in conjunction with non-specific complement, constitutes what is called a "ferment," and is capable of splitting a protein molecule with the liberation or formation of a toxic moiety responsible for the lesions and symptoms of anaphylaxis. Just as other normal amboceptors, such as hemolysins, are present in normal serum, so these protein amboceptors or albuminolysins may be present for various proteins, explaining the production of the anaphylaxis poison in vitro with a normal serum when the latter is fresh and active, i. e., when complement is present. Theoretically, at least, it should be possible to detect the anaphylactic amboceptor in a serum by a method of complement fixation, although practically this is not the case. The whole subject of " ferments" requires further study, and, as a result, our knowledge and views of antibodies and the processes of immunity in general are likely to undergo some change. The Humoral Theories of Anaphylaxis. — With the foregoing explanation of the chemical or humoral theory of anaphylaxis, I may briefly summarize all the more important chemical or protein poison theories advanced from time to time in explanation of the process. These include the following: 1. Richet held that the sensitizer, or anaphylactogen, contains a substance which he called "congestion" (because he did his original work with extracts of the tentacles of sea anemones, which are toxic and produce congestion of the internal organs), and that this generates in the animal another substance, known as the "toxogenin." The reaction between the latter and the homologous protein on reinjection sets free a poison, "apo toxin," which, because of its effect on the nervous system, produces the symptoms of anaphylaxis. This theory is practically the same, as that generally accepted today, except that the antigen is not of necessity primarily toxic for the animal. 2. Hamburger and Moro suggest that the first injection leads to the formation of precipitins, and that on reinjection precipitates are formed; these they contend, may, by the formation of capillary emboli, produce acute anaphylaxis, or atf least that precipitin formation runs parallel with the antibody formation. The symptoms of anaphylaxis, however, are not those of embolism, and there is no evidence to show that precipitation occurs in vivo, although, as Zinsser points out, precipitins may play the role of sensitizers of the antigen, preparing them for final lysis or cleavage by a complement. In other words, the precipitin would act as an amboceptor, differing, however, from our general conception of the nature of amboceptors by being active in the absence of complement, unless precipitation is a secondary physical phenomenon in the nature of a colloidal reaction. "sensibilisinogen" and "antisensibilisin." When injected the first time the former develops in the body a substance called "sensibilisin," and on reinjection the sensibilisin and antisensibilisin continue to form a poison that acts on the nervous system. 4. Gay and Southard believe that, as a result of the first injection of serum, there remains in the circulation a protein substance called "anaphylactin," which is slowly absorbed and continues to stimulate the cells, leading to an abnormal affinity for the homologous protein, which, on reinjection, leads to anaphylactic shock. 5. Vaughan and Wheeler are of the opinion that, with the parenteral introduction of a foreign protein, the body-cells are stimulated to produce a specific zymogen or ferment that digests it. The protein of the first injection is so slowly digested that the effects are not recognizable. After the protein of the first injection has been disposed of, the new ferment continues to be formed in the cells, and on the second injection, after the proper interval has been allowed to elapse, this zymogen is activated and splits up the protein, which promptly and abundantly results in the production of the symptoms of anaphylactic shock. Vaughan believes that there is a non-specific poisonous group or moiety in each protein molecule which, when liberated by the ferment, is responsible for anaphylaxis. This poisonous group is held as being the same in all proteins, and hence the similarity of lesions and symptoms of anaphylactic intoxication in animals regardless of whether the protein is of animal, vegetable, or bacterial origin. The nature of the ferment is not clear. In 1907 they regarded it as a zymogen — a theoretic labile chemical body resulting from intramolecular rearrangement in the protein molecules of the cell. Little is known of the action of these ferments except that in some manner they cause cleavage of the protein molecule and liberation of the toxic moiety. Later, Vaughan speaks of the ferment as consisting of an amboceptor and a complement, the ferment (presumably the complement portion) being inactivated by a temperature of 56° C. and reactivated on the addition of serum and organic extracts. Although Vaughan's theory best explains the nature and source of the anaphylactic poison, that of Friedberger explains the production of the "ferment," or rather the protein sensitizer (amboceptor), which, with a complement, digests the protein and sets free or produces the protein poison. 6. Friedberger has attempted to explain anaphylaxis on the basis of Ehrlich's side-chain theory of the action of antigens and the production of antibodies similar to toxin-antitoxin immunity. This theory assumes that, on the first injection, the protein finds but few groups of cellular receptors with which it can combine, and for this reason it is not poisonous. During the period of incubation the animal cells develop receptors specific for the homologous protein; with a single small dose of protein most of these receptors remain attached to the cell (sessile) ; on repeated injections, the newly formed receptors are in large part cast off into the blood, and constitute the precipitins. In this manner an animal relatively insusceptible to a foreign protein is rendered highly susceptible, and on the second injection the protein is anchored firmly to the cell, just as the cells of an animal may anchor diphtheria toxin. One of the essential features of this theory is that it assumes that, ordinarily, the receptors are not preformed in sufficient numbers to anchor enough protein to injure the animal with the first injection, regardless of the size of the dose. On the other hand, tetanus and diphtheria toxins find large numbers of sessile or cellular receptors, and are highly toxic on the first injection. As originally evolved, the theory did not explain the nature of the toxic agent responsible for the lesions and symptoms of anaphylaxis, and made no mention of the protein poison. Nevertheless it affords the best explanation we have on the formation of the " ferment" or protein sensitizer (amboceptor). At one time Friedberger believed that anaphylaxis could be explained on the basis of a precipitin reaction. Anti-anaphylaxis was explained on the assumption that the protein of the reinjection uses up the sessile receptors already developed, and, accordingly, not enough are present at the end of the period of incubation to produce anaphylactic shock. Passive anaphylaxis was explained on the ground that the free receptors in the blood of a sensitized animal become, on injection into a fresh animal, anchored to the cells, thus forming fixed or sessile receptors that anchor the protein on reinjection and lead to anaphylaxis. Nolf1 has proposed a theory of anaphylaxis that has come to be known as the ''physical theory." It assumes that the active constituent of proteins is a thromboplastic substance that disturbs the colloidal equilibrium of the blood and leads to the deposition, on the surface of the leukocytes and the endothelial cells of capillaries, of a delicate film of fibrin. Thus stimulated, the cells pour out an unusual amount of antithrombin. On account of the consumption of a part of the fibrinogen and the increased formation of antithrombin the blood fails to coagulate after anaphylactic shock or peptone poisoning. Owing to the coagulation deposits on the endothelial cells, the viscidity is increased and the leukocytes adhere to the vessel-walls, thus accounting for the leukopenia observed after protein injection. The enclothelial cells are injured, and the walls of the capillaries become more readily permeable, thus accounting for the local edema often seen in anaphylaxis. The fine capillaries of a given area may be occluded by thrombi, thus explaining the necrosis characteristic of the'Arthus phenomenon. The irritation of the endothelial cells extends to the smooth muscle, leading to vasoparalysis and the characteristic fall in blood-pressure. The affinity of the endothelial cells for the protein is stimulated by the first injection, and acts in a fulminating way on reinjection, thus explaining the suddenness of anaphylactic shock. The theory, therefore, also assumes the formation of a ferment that acts primarily upon the proteins of the blood, leading to the formation of fibrin, which, as it were, mechanically induces the lesions and symptoms of anaphylaxis. While it offers a plausible explanation, the theory is not well supported, and at best may be regarded as a modification of Vaughan's theory, demonstrating one way in which the protein poison may act. THE CELLULAR THEORY OF ANAPHYLAXIS Many investigators have attempted to explain anaphylaxis on the basis that the reaction is a cellular one, that is, that the antibody is within the cell and that the antigen-antibody reaction occurs in this position rather than in the blood-stream by means of free or circulating antibody and antigen. According to the "cellular theory," if the serum of an immunized animal containing the anaphylactic antibody is injected into a normal animal (passive anaphylaxis) and is followed by an injection of the antigen, an anaphylactic reaction cannot occur before the elapse of sufficient time for the antibody to become anchored to cells. The "humoral theory," on the other hand, assumes that the antigen meets the antibody in the blood-stream and explains the time required between the injection of immune serum and antigen in passive anaphylaxis as due to a failure of rapid union between antigen and antibody unless qualitative relations between the two are accidentally correct. The early theory of Friedberger,1 explaining anaphylaxis on the basis of "sessile receptors"; the experiments of Friedberger and Girgolaff,2 who passively sensitized normal animals by transplanting the thoroughly washed organs of a sensitized animal; the transfusion experiments of Pearce and Eisenbrey,1 who transferred the blood of a sensitized animal to a normal animal and the blood of a normal animal to a sensitized one, finding that the latter, but not the former, reacted when the antigen was injected as soon as the transfusions were completed; the work of Coca,2 who found that sensitized guinea-pigs would still react after being thoroughly bled and perfused with salt solution ; the investigations of Schultz,3 Dale,4 and particularly of Weil,5 showing that the excised and washed muscles of sensitized animals would react in vitro in a bath of Ringer's solution when the antigen was added, support most strongly the cellular theory of anaphylaxis as emphasized also in the work and recent communications of Doerr.6 In the opinion of Weil, Doerr, Bayliss, Coca, and others the "cellular" theory is the only tenable one today. According to this theory of anaphylaxis, the antibody is in or on the body cells; upon union with the antigen the cells undergo a physical shock which has been likened to an electric shock, and this constitutes the basis of the anaphylactic reaction without the formation of any intermediate or chemical poison. As emphasized by Weil7 there is no direct evidence of the production of a chemical poison or anaphylatoxin during or after an anaphylactic reaction in the living animal. This poison has not been satisfactorily demonstrated in the blood and in animals recovering from a general anaphylactic reaction, the phenomena being more suggestive of a transitory "shock" than of an intoxication with a chemical poison. On the other hand, the mass of experimental evidence indicating that the anaphylactic reaction is not purely cellular, but at least in part an intra vascular reaction, is too strong to be discarded. As pointed out by Zinsser and Young,8 the necessary time usually required in passive anaphylaxis between the injection of immune serum and antigen may be due to slow union between antigen and antibody in the blood-stream, on the basis that the anaphylactic reaction involves the interaction of colloids and that a protective colloid is responsible for the slow union of antigen and antibody unless its influence is obviated by exact quantitative proportions between antigen and antibody, which under experimental conditions may be secured in a more or less accidental manner. As antibodies are produced by the body cells, it is reasonable to believe that they are present in the protoplasm of the cells, and, even after thorough washing of the tissues, are capable of union with their antigen. It is entirely likely that these attached or sessile antibodies are chiefly concerned in the phenomena of anaphylaxis, but I cannot subscribe entirely to the cellular theory, because of the mass of experimental data bearing on the production of the protein poison, particularly in vitro, by the free antibodies in an immune serum. The reactions in vivo of hemolysis and bacteriolysis, which are lytic processes apparently similar to those concerned in anaphylactic reactions, are probably intravascular processes; it is also likely that in anaphylaxis to formed antigens the first phase of the reaction, that is, the disruption of the antigenic cell, is intravascular, showing that lytic reactions entirely analogous to our conception of the mechanism of the production of the protein poison in anaphylactic reactions may occur in the blood-stream. For these reasons alone I cannot exclude the free antibodies in the blood from playing some role in the phenomena of anaphylaxis. The extreme sensitiveness of the body cells in anaphylaxis to the protein suggests to me that the cells acquire the property of union with the protein poison to an extreme degree, as if they were furnished, as a result of the initial dose of foreign protein, with an increased number of specific and sessile receptors for the protein poison. In other words, while the protein poison may be produced in the cells by sessile receptors or in the blood-stream by free receptors, anaphylaxis itself, that is, the hypersensitiveness of the cells, is due to the increased binding power of the cells for the protein poison. In our opinion this in part explains true allergy, that is, the effects of local or general sensitization (production in the protoplasm of the cells or increased receptors for the protein poison), and the immediate well-marked or even violent effects following the production of what must be very minute amounts of protein poison, as in the cutaneous tuberculin reaction or in the classical horseserum reaction in guinea-pigs, following the intravenous injection of the intoxicating or second dose of protein in very minute or infinitesimal dosage. Passive anaphylaxis is produced by the injection of normal animals with the blood or serum of animals or persons already sensitized. It is similar to passive immunization, and is specific for the anaphylactogen with which the donor is sensitized. PASSIVE ANAPHYLAXIS 597 The second animal may be of the same or of another species. If it is of the same species, the condition induced by the transference of the serum is called homologous; if it is of a different species, it is known as heterologous, or passive anaphylaxis. Passive anaphylaxis was discovered almost simultaneously and independently by Gay and Southard,1 working with guinea-pigs, by Nicolle,2 with rabbits, and by Otto,3 who, working with both guinea-pigs and rabbits, showed that a rabbit immune serum would passively sensitize a guinea-pig. At this place it may be mentioned that the new-born of a sensitized mother animal may be sensitive, and remain so for a longer or shorter period of time. This is an illustration of passive homologous anaphylaxis, a process that has been especially studied by Rosenau and Anderson, Gay and Southard, and Otto, the last observer finding that young guineapigs remained sensitive for as long as forty-five days after birth. This function of transmitting the condition of sensitization is solely maternal: the male takes no part whatever in the transmission of these acquired properties. The Production of Passive Anaphylaxis. — An important phase of this subject over which there has been considerable difference of opinion refers to the question whether some time must elapse between the injection of immune serum and anaphylactogen before anaphylaxis is produced, or whether intoxication may follow the simultaneous injection of both antibody and antigen. Thus Gay and Southard, in their early studies, found their recipients first sensitized on the fourteenth day after injection of immune serum. Otto and Friedmann observed shock twenty-four hours after injecting the anaphy lactic serum subcutaneously and antigen intraperitoneally. By injecting both serums intravenously and simultaneously, Doerr and Russ finally succeeded in producing acute anaphylaxis and almost immediate death. Weil, ^however, believes that the simultaneous injection of antigen and of antiserum into opposite jugular veins in the guinea-pig never produces an anaphylactic reaction, in spite of the use of wide quantitative variations in both substances. On the other hand, if the antigen were injected a few hours after the antiserum, in the same quantitative variations, the reaction occurred regularly. From this it was concluded that the body-cells anchor the of an interaction between the cellular antibodies and the antigen. It would appear that passive anaphylaxis is not wholly determined by the amounts of antigen or antibody, but by the proportion that exists between the two. For example, Friedmann,1 in his studies on passive homologous anaphylaxis in rabbits, found that, by employing 2.5 c.c. of antiserum with from 2.5 to 0.25 c.c. of antigen, no results were observed, whereas positive reactions were obtained when the amount of antigen was reduced from 0.025 to 0.0025 c.c. Ordinarily, normal guinea-pigs may be passively sensitized by 0.1 to 0.5 c.c. of serum injected intraperitoneally, and anaphylactized one or two days later by an intravenous injection (0.1 to 0.5 c.c.) of the antigen. The immune serum may be prepared by injecting rabbits with horse serum, after the methods for the production of precipitins described in Chapter IV. The duration of passive sensitization is quite variable. Weil2 found that guinea-pigs sensitized with a homologous serum, that is, with the serum of another guinea-pig sensitized with horse serum, remain typically anaphylactic as long as seventy days after the injection. With heterologous sensitization, however, as with the serum of a sensitized rabbit, hypersensitiveness is almost invariably lost by the tenth day. One explanation of this would be that a heterologous serum is excreted more rapidly than a homologous serum, a condition commonly observed in serum therapy with any heterologous serum. The Mechanism of Passive Anaphylaxis. — Presumably the mechanism of passive anaphylaxis in terms of the humoral theory is relatively simple, and consists in the transfer of the specific protein sensitizer or amboceptor that unites the anaphylactogen or protein antigen with a complement, bringing about lysis or cleavage of the protein and liberation of the toxic moiety responsible for the lesions and symptoms of anaphylaxis. In other words, the mechanism of passive anaphylaxis may be likened to passive antibacterial immunization, with, however, one important clinical difference, namely, that whereas in the former the microorganisms are destroyed without apparent injury to the host, in anaphylaxis the body-cells are acutely poisoned. However, a similar phenomenon in the serum treatment of disease, with lysis of bacteria, may be overshadowed or possibly prevented by a condition of anti-anaphylaxis. The term anti-anaphylaxis was first applied by Besredka and Steinhardt to a condition of insensibility to further injection of the anaphylactogen that may follow recovery from anaphylaxis, or be induced artificially by a single or by repeated small injections of the anaphylactogeh during the incubation period following the first injection, and before sensitization is completed. The state is usually only temporary, the animal gradually becomes sensitive again after three weeks. Theobald Smith had observed that those guinea-pigs that had received the largest dose of diphtheria toxin-antitoxin mixture more frequently survived the second dose than did those that received smaller doses. Rosenau and Anderson found that animals reinjected before the end of the period of incubation did not become responsive until some time later. Otto has also made this observation, but the most thorough study of the subject has come as the result of the researches of Besredka and Steinhardt. Experimental Production of Anti-anaphylaxis. — It has long been known that the larger the first or sensitizing injection of antigen, the greater must be the dose of the second or intoxicating injection, indicating that a large sensitizing injection introduces the factor tending to produce the condition of anti-anaphylaxis. Partial desensitization, or anti-anaphylaxis, may be produced by the injection of a sublethai intoxicating dose of anaphylactogen during the period of incubation or at its close. Quantitative relations between the size of the sensitizing, intoxicating, and desensitizing doses of antigen and the period of incubation have been worked out in a series of studies by Weil,1 both in the living guinea-pig and on the excised uterus, after the graphic method of Dale.2 Weil found that a small sensitizing dose of horse serum (0.01 c.c. subcutaneously) is followed by a relatively prolonged period of incubation (from fourteen to sixteen days) ; that the minimal anaphylactic or lethal dose is small (0.02 to 0.05 c.c.) ; that the blood, as a rule, does not contain more than one sensitizing unit; and that the minimal desensitizing dose is small (0.01 c.c.). Conversely, after repeated large sensitizing doses (2 c.c. of serum subcutaneously on each of three days in succession) the incubation period is shorter (about ten days after the last injection); the minimal anaphylactic lethal dose is larger (0.4 c.c.), and the minimal desensitizing dose is at least more than 0.2 c.c. of serum given intravenously. Besredka and Steinhardt observed that the refractory state could easily be developed in sensitized guinea-pigs by one of the following methods: (1) The intracerebral injection of 0.25 c.c. of horse serum before the expiration of the period of incubation (twelve days). (2) The intracerebral injection of less than the fatal dose (from 0.002 to 0.025 c.c.) after the period of incubation. (3) Rectal injections of from 5 to 10 c.c. of serum. (4) By slowly reinjecting small amounts while the animal is deeply narcotized with ether or alcohol. As shown later by Rosenau and Anderson, a narcotic may mask but does not prevent the occurrence of severe or fatal symptoms. Of these methods, Besredka prefers the rectal injection, or, better still, the subcutaneous injection of less than a fatal dose. The subject of anti-anaphylaxis is of great importance from its relation to serum therapy. No satisfactory method for producing this state in a sensitized person has as yet been devised, owing, probably, to the important quantitative factors shown, by the studies of Weil, to exist. This subject will be discussed again in the following chapter, under the head of Serum Sickness. The Mechanism of Anti-anaphylaxis. — A true explanation of this phenomenon cannot as yet be given. In the first place, the term antianaphylaxis cannot be considered a proper one, as the animal is not entirely and permanently anti-anaphylactic, but subsequently becomes sensitive. The blood-serum of a refractory or anti-anaphylactic animal does not confer a similar condition on a second sensitized animal. As previously stated, Friedberger believes that the refractory state is due to neutralization or absorption of the anaphylactic antibody by the antigen, but this explanation does not fit in with the facts, first, because the serum of an anti-anaphylactic animal will still passively sensitize a normal animal, and, secondly, as shown by Weil, passive anaphylaxis of a guinea-pig, such as that induced by the injection of a rabbit antihorse serum, may be prevented for at least eight days by a previous injection of normal rabbit or sheep serum. In other words, it would appear that normal rabbit and sheep serum may protect the body-cells of the guinea-pig against the anaphylatoxin produced by horse protein and horse anaphylactin or antibody. In explanation of this paradoxic and non-specific reaction Weil,1 who believes in the cel1 Jour. Med. Research, 1914, 30, No. 3, 299. SPECIFICITY OF ANAPHYLAXIS 601 lular theory of anaphylaxis, has tentatively advanced the hypothesis that the indifferent serum persists in the body-cells and markedly lowers the reactivity of the cellular antibodies. The anaphylactin, or so-called anaphylaxis antibody, displays quite the same characteristics of specificity as do the other immune antibodies, in that proteins of closely related species tend to interact, whereas proteins of very distinct biologic or chemical nature are easily distinguished. In other words, the anaphylactic reaction is highly specific, and of considerable value in the study and identification of different proteins. For example, Dale has recommended the use of the graphic method in ntro with excised muscle (uterus) for the identification of the protein substances, such as blood-stains. Guinea-pigs sensitized with human serum will react best with human serum, and to a lesser extent with that of the higher apes, but not at all with the serum of the dog, ox, or fowl. Wells and Osborne,1 working with purified vegetable protein, were able to demonstrate that a single isolated protein (hordein or gliadin) may contain more than one antigenic radical, and that not the whole protein molecule, but certain groups thereof, determine the specificity. Wells2 was able to distinguish in the hen's egg five distinctly different antigens, and these corresponded to five proteins that were isolated by chemical methods, so that it would appear that the specificity of the anaphylaxis reaction is determined by the chemical structure of the reacting proteins, rather than by their biologic origin. Whether the chemical differences that determine specificity are of quantitative nature, or whether they are sometimes dependent upon the number and relationship of the amino-radicals, as was suggested by Pick, remains to be determined. IMMUNITY IN reviewing our knowledge of the nature and mechanism of anaphylaxis we found that ordinarily innocent substances, such as sterile normal serum and egg-albumen, when injected into animals, may give rise to severe and even fatal intoxication, not because these substances are poisonous in themselves, but because the antibodies which they stimulate the body-cells to produce react with the innocent protein in the body fluids or cells or both producing the phenomenon called anaphylaxis. Here, indeed, we have an example of antibodies apparently injuring our body-cells instead of protecting them. And now the question very naturally arises, are the lesions of the many diseases caused in a similar manner, the antibodies acting with the bacterial cell and producing the anaphylactic state? In view of the fact that they may do actual harm, in some instances at least, are antibodies really protective and beneficial, and if so, in what manner? It is not my purpose to review here the general subjects of infection and immunity, but to discuss briefly the intimate connection of what we call anaphylaxis or allergy with infection, and to show that anaphylaxis may be the first step in the process of immunity; indeed, that wellmarked antibacterial immunity may be an example of an early and efficient "anaphylactic" reaction. In other words, while the striking and severe symptoms of serum anaphylaxis in either man or lower animals give us the impression that we are here dealing with some new, distinct, and strange phenomenon, these may be, in fact, but exaggerated and severe examples, largely dependent upon quantitative factors of what occurs during each infection. More than this, in the terms of the humoral theory of anaphylaxis these symptoms may be due in part to the action of a poison formed or released through the destruction of the antigen by the antibody; the antibody being, therefore, apparently imperfect in its action, as it does not neutralize the protein poison. Taking, as an example, a substance, such as sterile horse serum, while RELATION OF ANAPHYLAXIS TO INFECTIOUS DISEASES 603 if antibodies are present in our body-fluids, or later if some of the serum persists in the body until antibodies are produced. It would appear, therefore, that when the antibodies are produced for a given infectious agent, then the severity of the disease becomes apparent ; that the lesions and symptoms are due not only to the infecting microorganism and its products, but to the results of their destruction. An invading army may do some pillaging, but the greatest injury is done when the defenders begin the attack, the resulting fire and destruction doing more harm than the invaders themselves. While Vaughan and his coworkers were studying the protein poison in vitro, and Friedberger was investigating it in vivo, the former and then the latter aiming to show that the poison liberated from the protein molecule through the action of specific ferments is responsible for the lesions and symptoms of disease, von Pirquet was studying the question from the clinical aspect, formulating a working hypothesis on the nature of infection and immunity based upon the principles of anaphylaxis, a theory that has been supported by experimental data and has thrown a new light upon the nature and mechanism of these processes. RELATION OF ANAPHYLAXIS TO INFECTIOUS DISEASES Although we may not be in general accord regarding the mechanism of anaphylaxis, if the humoral theory is accepted there is a general agreement as regards the nature of the anaphylatoxin responsible for the lesions and symptoms of anaphylactic intoxication, namely, that it is a protein cleavage product. In other words, a foreign protein and, indeed, the misplaced protein of our own body-cells may be disrupted or digested by an antibody, and liberate or generate a poison that, being derived from protein, is known as the protein poison. In the chapter on Infection it was stated that Vaughan and his collaborators regard this protein poison as the same for all proteins, and as responsible for all infectious diseases, the particular lesions and symptoms of each disease being dependent upon the site of the infection and, accordingly, upon the location of the protein poison. Similarly, in the preceding chapter we asserted that anaphylaxis may be ascribed to an exactly similar phenomenon, namely, the splitting of the foreign protein by an antibody (ferment) and the liberation of a protein poison. In studying serum sickness, an anaphylactic phenomenon frequently observed in man following the administration of horse serum, von Pirquet argued that the period of from eight to ten days usually following the injection 604 ANAPHYLAXIS IN RELATION TO INFECTION AND IMMUNITY before the appearance of symptoms was the time required for the production of the antibody, which then reacted upon the serum still remaining in the body-cells and fluids, and that the products of this interaction caused the lesions and symptoms of serum sickness. It was then but a short step to apply these principles to other infectious diseases. This "period of incubation" was formerly regarded as representing a stage during which the infecting microorganisms multiply in the body of the infected individual, to that point at which they could give rise to symptoms of disease through the agency of their toxins or through interference with the metabolism of the host in other ways. But, as von Pirquet has pointed out, this theory does not hold in serum sickness, as the serum may be sterile arid no infecting microorganisms are at work. Instead, he and Vaughan would have us believe that during this period antibody formation is taking place, and that an antibody-antigen reaction will occur with the development of pathologic changes and symptoms just as soon as these changes have progressed to a certain point. The period of incubation will vary not only in point of time of reaction, but also qualitatively and quantitatively, and using this as a basis von Pirquet recognizes three main groups, depending upon whether the antibody is present in our body-fluids as the result of a previously acquired infection (accidental or by vaccination), or whether it must first be developed. Group I : Reaction appears after eight to twelve days, as in measles, smallpox, whooping-cough, chickenpox, and other infectious diseases in which the antibodies must be developed before the symptoms are produced. This interval corresponds quite closely to that observed in serum sickness. If at this time the antigen, — i. e., either the albumins of the horse serum, if we are dealing with serum injections, or the bacteria in case of an infection — has disappeared from the body, no symptom will, of course, result; if, however, some of the material is still present, a reaction occurs, during which the protein poison (anaphylatoxin) is produced, and to which, in turn, the symptoms that then develop may logically be attributed. Group II: The reaction appears after three to seven days. If, on the other hand, the secondary infection, as. e. g.} pneumonia, erysipelas, etc., is acquired after a lapse of months or several years, or if the second injection of serum is given after this time, i. e., at a time when the antibodies called forth by the primary infection or first injection have disappeared, a certain interval of time will elapse before symptoms of sickness develop, as in the case of the first group. This interval, how- ever, instead of being from eight to twelve days, is now from three to seven, a fact readily explained on the basis that a cell that has once been stimulated to active antibody formation will subsequently respond to the same stimulus with increased activity. This has been called by von Pirquet the accelerated reaction. Group III : The reaction appears immediately. If the first injection of horse serum or infection is followed by actual disease or vaccination, the reinjection or reinfection is acquired at a time when the antibodies are present in the circulation in considerable amount, a reaction will occur either immediately or within the first twenty-four hours. This reaction may be quite virulent in intensity, although it is shorter in duration than when it occurs in the first group, von Pirquet speaks of this as the immediate reaction. It is to be observed in cases of serum sickness where the symptoms develop almost immediately following an injection of serum months and even years after a previous injection; it also occurs in cowpox vaccination, where a local reaction takes place very quickly and soon disappears after a previous attack of smallpox or vaccination. At the time of the second injection of serum or reinfection with bacteria a small amount of antibody may still be present; this will give an immediate though mild reaction, and is not enough to neutralize the total amount of foreign protein introduced. A portion of the latter, therefore, will result in the production of an additional amount of antibody, which occurs in an accelerated manner, and coming in contact with some of the free antigen, gives rise to the accelerated reaction. Hence we may have an immediate, followed by an accelerated, reaction. To illustrate these principles, von Pirquet names vaccinia as an example of an acute infection in which the processes may be observed on the skin. As the result of vaccination a colony of microorganisms is formed on the skin. For the first two days the local response is evidently traumatic in character. After the third or fourth day the specific reaction sets in, i^i the form of a small papular elevation surrounded by a small areola due to the local action of toxins or protein poison from disintegrated microorganisms. By the eighth day a vesicle has formed, and from its contents new colonies can be grown on thousands of other arms. But one or two days later the ferment-like antibody appears. The colony is attacked, its contents are digested, a toxic substance is formed that diffuses into the neighboring tissues, and the intense local inflammation which we call the areola appears. In addition the toxin enters the general circulation and fever sets in. Simultaneously the microorganisms are destroyed, and we may no longer be able to vaccinate with the contents of the now yellow pustule. After two or three days the real struggle is ended, although the local lesion may be aggravated by secondary infection, and the body contains the new antibody for a long time. If we now revaccinate, the antibody present will at once attack and digest the microorganisms introduced into the scarification, and, as these do not have time to multiply, only an extremely small amount of toxin is formed, which gives the "immediate or early reaction" in vaccinia. If a number of years have elapsed between the first and the second vaccination, antibodies may be absent or present in only small amount, but the body-cells have been "keyed up" by the first vaccination, and hence react more quickly to the second. The antibodies are produced in from three to five days, and attack the microorganisms before they have had time to multiply in sufficient numbers; the relatively small amount of digestion product produces a comparatively mild local inflammation and practically no general symptoms. This is sometimes known as the "immunity reaction," or vaccinoid, and is illustrated in Fig. 135. It would, of course, lead us too far were we to analyze all the different infectious diseases along these lines; suffice it to say that the anaphylactic principle serves to explain many points in the clinical symptomatology of disease that were not explained heretofore, or were ascribed to the effects of the bacteria and the bacterial products. I am not among those who, with Vaughan, would ascribe all symptoms to the protein poison alone; nor do I regard the part played by the microorganism as simply dependent upon whether or not it can grow in the body and produce the ferment antibody. In the acute toxemias, for instance, such as tetanus and diphtheria, where the amount and toxicity of the toxin are out of all proportion to the number of bacteria, and where the symptoms develop after a very brief incubation period, tissue changes and symptoms are in all probability not primarily due to any antigenantibody reaction, with liberation of the protein poison, but are rather to be attributed to a direct action of the toxin upon the body-cells, especially upon those for which the toxin possesses a special affinity. When the antibodies appear, we may rightfully assume that a ferment, in the nature of a protein amboceptor or lysin, appears with the antitoxin, and theoretically we may expect a clinical reaction due to the protein poison or anaphylatoxin liberated from the bacilli. It may be that diphtheria antitoxin is in the nature of this ferment, or antitoxin and ferment may exist together and in this manner afford an explanation for the local destruction of the bacilli and the cleaning up of the membrane, the effects of the anaphylatoxin being overshadowed by the true toxin, or expressing itself in the paralyses and other symptoms commonly ascribed to the toxones. von Pirquet concedes that in scarlatina the primary symptoms of the malady, i. e., the eruption and angina, are due to a pure toxin effect, — to the true scarlatinal virus, — but that the sequelae, and notably the nephritis, are the expression of the action of anaphylatoxins that are formed when the corresponding antibodies are produced. Likewise in such infections as typhoid fever and pneumonia, I cannot eliminate the action of true toxins and endotoxins, and ascribe all the symptoms to a protein poison or anaphylatoxin. It is not always true that the incubation period is devoid of symptoms. Mild and evanescent symptoms are frequently present, and it is but natural to ascribe these to the effects of bacterial products themselves. After a time, when the bacteria have multiplied and reached special tissues, the symptoms become more intense and the typical lesions are produced. These may be ascribed to the result of the combined action of toxins themselves and the protein poison, rather than to the protein poison itself to the entire exclusion of the metabolic products of the bacteria. In the present state of our knowledge it is, of course, very difficult to decide which symptoms in a given disease are due to bacterial toxins, which to endotoxins, which to ptomains, which to a mechanical action of the bacteria, and which to the protein poison or anaphylatoxin. While it is perfectly true that we can now understand symptoms as due to protein poison that cannot be ascribed entirely to toxins and endotoxins, it seems to me unwise to ascribe all lesions and symptoms to the toxins, on one hand, or the protein poison, on the other. It is necessary for us to know the manner in which the protein poison is produced, how infection is so closely allied to what we know as anaphylaxis, and that in any one disease, such as diphtheria, tetanus, and pneumonia, the toxins and endotoxins are of primary and immediate importance, whereas in others, such as smallpox, chickenpox, and whooping-cough the protein poison itself is of primary importance and that in all disease all factors may be concerned to a more or less degree. When we come to consider non-infectious diseases, — and by this I refer particularly to the symptom-complex of serum disease and those conditions commonly ascribed to idiosyncrasies toward certain substances, such as horse asthma, satinwood dermatitis, buckwheat poisoning, urticarias due to the ingestion of strawberries, pork, and the like, — the relation of anaphylaxis to the processes involved is more intimate. Here, indeed, we may regard the symptoms as entirely anaphylactic in origin and character, as the substances in themselves, such as serum, egg-albumen, horse effluvia, etc., are not regarded as toxic and we have not the coincident effects of toxins, endotoxins, and ptomains, as in bacterial infections. Here, indeed, we may more readily accept Vaughan's and Friedberger's theory as to the action of the protein poison, regarding it the same in all proteins, and set free from the protein molecule by the socalled "ferment," which is in the nature of a protein sensitizer or amboceptor, and which, with a complement, brings about lysis or cleavage of the molecule, just as a similar ferment or antibody, called bacteriolysin, disrupts a bacterial cell or its protein constituents. In short, we may say that the work of Vaughan and his collaborators has shown us the presence of this poison in all protein material with a method of extracting it in vitro. Friedberger and his collaborators have shown how this poison. is set free in the body through the agency of the "ferment." von Pirquet has studied the question at the bedside, dispensing with the microscope and test-tube and depending solely upon the vital processes and reaction, skilfully combining laboratory findings with bedside observations— in fact, he built up his theory on the nature of infection and immunity before the role of the protein poison was discovered, and subsequent work has added support to his conceptions. Of clinical and practical importance in this connection are serum disease and hypersensitiveness or idiosyncrasies for other proteins and certain drugs. SERUM DISEASE This name was applied by von Pirquet and Schick1 to the various clinical manifestations, such as eruptions, fever, edema, and pain in the •joints, following the injection of horse serum. These symptoms are due to the horse serum itself, for, as was early shown by Johannessan,1 Bokay,2 and others, they may manifest themselves after the injection of sterile normal horse serum. The serum, moreover, of certain horses appears to be more likely than that of others to cause these symptoms, thus accounting for the fact that one lot of antitoxin will cause a higher percentage of serum sickness than will another. A concentrated serum is not so likely to produce serum sickness as whole serum, owing partly to the fact that smaller doses of it are given. According to Rolleston and Ker, the frequency of serum sickness is, as a rule, in direct proportion to the amount of serum given, and in inverse ratio to the severity of the attack; in other words, we may expect to encounter it most often in mild and moderately severe cases that have received very liberal dosages of serum. The Nature of Serum Disease. — Serum sickness is regarded as a true anaphy lactic phenomenon. We are prone to call the severe, fatal, and rare instances of death following serum injection examples of anaphylaxis, and to regard serum sickness as a different condition. Both are fundamentally the same, except that in the first instance the body-cells are for some unknown reason unduly and highly anaphy lactic. Fortunately, this undue hyper sensitiveness is frequently foreshadowed by the asthmatic or hay-fever-like attacks which the susceptible person may exhibit when he enters stables or is otherwise around horses. It goes without saying that horse serum should never be given to such persons. While serum sickness is usually due to horse serum for the reason that the horse is so commonly employed in the preparation of various curative serums, the serum of the ox, rabbit, and other animals may induce the same train of symptoms in addition, in some instances, to producing a direct toxic effect. An immediate reaction rarely follows the first injection of serum unless the patient is one of those unfortunate but rare persons who in some manner have been rendered highly sensitive to horse protein. In the majority of instances symptoms do not develop for from eight to twelve days, during which time the antibody is being produced. When antibody formation has reached a certain point, it reacts upon any of the horse serum that may persist in the cells or circulation, producing the anaphylactic reaction. If the dose of serum has been small, antibody forma- tion goes on as usual, but the serum may not persist in the circulation. Hence symptoms do not develop in such a person, although if reinjected subsequently symptoms will appear. This is one reason why a concentrated serum is not so likely to produce serum sickness, since a smaller quantity of it is injected. If, however, the patient has received an injection of serum some months previously, a reinjection is likely to be followed by an immediate reaction, that is, the symptoms appear within from twenty-four to fortyeight hours. If the first injection had been given a year or more previously, no antibody may be present in the blood, so that an immediate reaction does not occur. If, however, the cells once stimulated are "keyed up" indefinitely, and, accordingly, antibody formation is quite rapid, so that we find symptoms developing in from four to seven days after injection — the accelerated reaction. Or a small amount of antibody may be present which gives a mild reaction around the site of serum injection, followed in from four to seven days by a general reaction, this being an immediate followed by the accelerated reaction. As was previously stated, anaphylaxis is specific — that is, a person receiving ox serum in the first injection would not be affected subsequently by an injection of horse serum, but only by ox serum. For this reason it has been recommended that diphtheria antitoxin to be used for prophylactic purposes should be prepared by immunizing cattle, reserving the horse serum for treatment if the disease should be contracted subsequently. and adenitis. The most obvious and important of the symptoms are undoubtedly the various forms of rash. In 1000 consecutive cases of diphtheria treated with antitoxin in the Philadelphia Hospital for Contagious Disease, a rash developed in 430, or 43 per cent. The time of appearance of the eruption depends, as was just stated, upon whether or not the patient has been injected on a previous occasion, and if so, the length of the interval between the first and subsequent injection, and to a lesser extent upon the amount of the first injection, these factors influencing the quantity of antibody present at the time of reinjection. Of the 430 cases just mentioned, the time of appearance of the rash, in days, after subcutaneous injection of antitoxin, was as follows: In this table are included some cases of reinjection, as, e. g., scarletfever patients who received a routine immunizing dose of antitoxin upon admission, and another after having contracted diphtheria; also cases of diphtheria that became reinfected within a few months after their discharge from the hospital. As will be seen, about 63 per cent, of cases develop a rash between the sixth and the ninth day after the injection of antitoxin. Three main types of rashes are generally recognized : 1. Urticarial Rashes. — If we include in this group all eruptions that present a resemblance to urticaria, these rashes are the most common, constituting from 70 to 90 per cent, of all eruptions. They usually appear after the seventh day, becoming manifest first about the site of injection. Large, irregularly shaped, and scattered blotches appear, frequently with true wheals in the center (Fig. 123), accompanied by intense itching and irritation. Sometimes true wheals do not appear. The rash is often very profuse, and fresh blotches may continue to appear for two or three days. Occasionally, the rash is quite sparse and mild, and may disappear within twenty-four hours. 2. Multiform Rashes. — This type of rash is quite common. It is often circinate in its arrangement, or occurs in large blotches mixed with a scattered morbilliform or measly form of rash (Fig. 124). Different parts of the body may present different appearances at the same time. This rash may occasionally closely simulate true measles, especially since it involves the face, and as the conjunctive are likely to be congested in almost any variety of serum sickness. It is differentiated from measles by the fact that Koplik's spots are absent, there is no prodromal rise in temperature, the papules are not elevated above the skin as much as in measles, and that the eruption frequently starts from the site of injection, instead of on the face. 3. Scarlatiniform Rashes. — This type of rash occasionally occurs, and may bear so close a resemblance to true scarlet fever as to be indistinguishable from it. The eruption usually appears early, that is, in from the first to the sixth day after injection, and may vary from a uniform erythema which first appears about the site of injection, to a true punctate scarlatinal rash. The differentiation of these rashes from the true scarlet-fever eruption is one of the greatest sources of trouble in hospital practice, especially when they develop in the diphtheria wards, where occasional cases of true scarlet fever are always likely to appear from time to time. The absence of the following symptoms, or their occurrence only in mild degree, would favor a diagnosis of serum disease : Fever, or, at least, the presence of but a mild pyrexia, the vomiting, the typically furred tongue, the angina, or at least but a mild throat involvement, and the leukocytic inclusion bodies — all forming the symptomcomplex of true scarlatina. In many instances, however, it is necessary to isolate the patient, when speedy recovery, absence of complications, and less definite desquamation, which does not involve the palms and soles, indicate that the patient was suffering from serum disease and not from scarlet fever. Severe Serum Disease. — The severer forms of serum disease, characterized by sudden onset, — often within a few minutes after the injection of serum, — extreme dyspnea, prostration, and death are, fortunately, rare, about 40 cases in all being now on record. While physicians are justified in exercising care and caution in the administration of serum, there are no absolute contraindications to its use except status lymphaticus and those instances where the person is known to be hypersensitive to horse serum. Occasionally sudden and severe dyspnea and prostration accompany an immediate reaction when a reinjection of serum is given within a few weeks after the first. Persons suffering with asthma are also bad risks, especially since the effects of serum disease upon the bronchial mucosa are likely to aggravate the already existing condition. This subject will be discussed in greater detail under the head of Contraindications to Passive Immunization in Chapter XXX. The Detection and Prevention of Serum Disease. — Anaphylactic phenomena can usually be expected to occur if serum is given within a year or so following a previous injection. Persons who experience discomfort when about horses should always be closely questioned. Figure 125 Dr. W. P., anaphylactic reactions fifteen minutes after application of serum; rabbit serum in the upper; horse serum in the lower. Subject to asthmatic attacks when in an animal house or stable where rabbits, horses, and guinea-pigs are kept. shows the urticaria-like lesion that develops on the arm of one of my colleagues following scarification and the thorough application of a drop of horse serum. This man is also susceptible, to a lesser extent,. to guineapig and rabbit serum, and is seized with sneezing and distressing dyspnea after .entering a house where these animals are kept. Thayer has reported a case of buckwheat hypersensitiveness where vaccination with the flour resulted in a local reaction. It would be well for physicians to make this simple test whenever they suspect a patient of being hypersensitive to horse serum. All that is necessary is to cleanse the arm with alcohol, scarify, as when vaccinating with cowpox virus, and rub in a drop of the diphtheria antitoxin with a tooth-pick or some suitable instrument. The reaction usually appears within fifteen minutes, and there are usually no, or but very slight, general symptoms. 1. A preliminary injection of 0.5 c.c. of serum as antitoxin may be given, followed in three or four hours by the regular injection. While it is difficult to produce anti-anaphylaxis (see Chapter XXIX), this method is in common use. 2. According to Auer and Lewis,1 Auer,2 Anderson and Schultz,3 Biedl and Kraus,4 and Karsner,5 atropin sulphate has a distinct protective action against the asphyxia of acute anaphylaxis in the guinea-pig. It may be well to administer from yiir to YQIT grain of the drug hypodermically before injecting the serum, and once or twice subsequently, at intervals of twelve hours, in those cases in which hypersensitiveness is suspected, especially when serum has been injected within a year's time. 3. Rectal injections of serum have been advised by Besredka, who bases his recommendations upon the fact that by this route absorption takes place slowly and desensitization is gradual. While in the chapter on Serum Therapy I have frequently advised the intravenous injection of serum, it is to be understood that this applies to first doses. It is far more dangerous to give serum intravenously to those injected on a former occasion; in these instances the physician will do well to give his injections intramuscularly or subcutaneously, when, if symptoms develop, they will not be explosive nor so dangerous. Since rectal injections are usually refused, the serum may be administered very slowly subcutaneously. The Treatment of Serum Disease. — In the majority of instances no treatment is necessary. Calcium chlorid and lactate, in doses of from 3 to 5 grains, have been advocated as a prophylactic and as a cure, but they are of doubtful utility. Soothing lotions, a brisk cathartic, and sedatives are indicated, and occasionally an opiate is advisable. The administration of adrenalin chlorid by subcutaneous injections frequently affords quick relief; as its effects are of short duration, repeated doses may be necessary until the urticarial rash has subsided. In the rare acute attacks marked by extreme dyspnea or rapid and shallow breathing with rapid and feeble pulse, atropin and caffein should be administered hypodermically. IDIOSYNCRASIES Studies in anaphylaxis have also offered an explanation of many, if not of all, of those peculiar instances in which the inhalation of some animal effluvium or of the pollen of certain plants or the ingestion of certain food-stuffs and drugs is followed by a train of symptoms, among which asthma and an urticarial rash are usually quite prominent. Hitherto these manifestations have not been understood, and were simply classed as idiosyncrasies — a term that is correct if we can make it mean hyper sensitiveness, for experimental investigation leaves little doubt but that in these persons antibodies for the substances in question are present in the body cells and fluids which with the particular protein when it gains access to the body produces the anaphylactic reaction responsible for the symptoms. One remarkable feature of these instances of idiosyncrasy, however, is the extreme hypersensitiveness of the bodycells, especially in those cases where the inhalation of such infinitesimal quantities of protein as are contained in the air will bring on a typical asthmatic attack in a person hypersensitive to horse protein. Examples of idiosyncrasy are relatively common. Susceptible persons learn to know that the ingestion of this or that substance is sure to be followed by various distressing symptoms. How and when these persons became hypersensitive are usually not known. In some instances the condition is found in one or both parents and in several members of the same family, making it appear to be hereditary. It is well known that animals may be sensitized by feeding them proteins not usually present in their diet, as by giving guinea-pigs horse serum or the flesh of other animals. may be mentioned : 1. Horse asthma, observed among those persons who are seized with sneezing, cough, dyspnea, coryza, and prostration when they come near horses, as in a stable or when driving. 2. Hay-fever, first ascribed to the pollen of plants by Elliotson in 1831, and thoroughly studied by Dunbar. Wolff-Eisner was the first to regard the reaction as a phenomenon of hypersensitivity or anaphylaxis. Individuals subject to hay-fever show a uniform series of symptoms at certain definite seasons, either in the early summer or in autumn. These are a reddening, swelling, and watering of the eyes, sneezing, a sore feeling in the throat and larynx, and asthmatic disorders. The instillation into the eye of a 1 per cent, solution of pollen in physiologic salt solution is usually sufficient to elicit a typical attack. In hay-fever we have the most marked instances of extreme hypersensitiveness; persons may be seized with an attack when some distance from the particular weed in question. Similar matitis venenata. 3. Food Anaphylaxis.— Certain foods, as eggs, buckwheat (phagopyrismus), pork, oysters, clams, lobsters, cheese, strawberries, gooseberries, and even vegetables, may act as poisons when ingested by persons who are hypersensitive to them. The symptoms are quite varied and are not all understood, as the subject is still in the experimental stage and requires much investigation from both the laboratory and clinical sides. Asthma has been frequently associated with a condition of. hypersensitiveness or allergy to certain foods by Goodale,1 Smith,2 Talbot,3 Schloss,4 and others. Symptoms referable to the alimentary tract vary from a feeling of "indigestion" and "heartburn" to severe diarrhea, vomiting, and abdominal pain. Various skin diseases, and particularly chronic eczema, urticaria, and angioneurotic edema, have been ascribed to food hypersensitiveness by Hazen,5 McBride and Shorer,6 White,7 Strickler and Goldberg,8 and Blackfan.9 The withdrawal of in an improvement or cure of an eczema. The diagnosis of food idiosyncrasy may be made on the basis of the experience of the patient that the ingestion of a certain food is followed by the occurrence of certain symptoms. Cutaneous and intracutaneous skin tests have also been employed, and apparently with success. The cutaneous tests are conducted by cleansing the skin of the arm with alcohol and abrading a small area of skin with a needle or von Pirquet borer. A small amount of the food, as a drop of egg-white or a drop of a 5 per cent, watery solution of the food, is now applied and rubbed into the abraded skin. A control test should be made with salt solution or water alone, as persons with an irritable skin may react with slight edema and erythema to the trauma. A positive reaction is indicated by the development of a well defined urticarial wheal surrounded by a zone of erythema and similar to the cutaneous serum reaction shown in Fig. 123. The reaction appears within five to ten minutes and lasts from twenty to forty-five minutes. The intracutaneous test is more delicate but somewhat more painful and likely to yield confusing and non-specific reactions. It consists in the intracutaneous injection of a very minute amount of a sterile solution of the protein of the food; usually 0.1 c.c. of 0.1 per cent, solution suffices. The reactions should not be read until after the elapse of forty-eight hours, as non-specific reactions may be observed during the first twenty-four hours after injection. Positive reactions are indicated by the formation of a tender papule with well-marked edema and erythema. As a general rule a series of tests with different foods may be done with the skin of both arms; soluble proteins of various foods are marketed in a convenient form for the tests. The treatment of food idiosyncrasy consists in the withdrawal of the food from the diet and attempts toward desensitization by feeding the food in very small and non-toxic doses until the skin reaction disappears or becomes very weak. If a person is very sensitive it is well to begin . with a dose of less than 0.01 gram three times per day, gradually increasing until the food may be ingested without apparent harm. The process of desensitization, however, is prolonged, and in my experience has not been accomplished in several cases of extreme hypersensitiveness to egg-albumen. Attempts have also been made to desensitize by subcutaneous injections of a sterile solution of the particular protein concerned. The initial doses should be small and approximately the smallest amount capable of eliciting an intracutaneous reaction. strychnin, morphin, etc., appear to develop a state of hypersensitiveness. My colleague, Dr. Fred Boerner, who is hypersusceptible to quinin and who suffers acutely following the swallowing of small amounts, has recently shown a reaction in his skin following the application of quinin to an abrasion.1 Klausner was able passively to sensitize guinea-pigs against iodoform by injecting the serum of a person sensitive to this drug. Examples of drug anaphylaxis or idiosyncrasy are more difficult to explain unless such drugs contain a protein substance. On the other hand, a drug may alter a body protein, rendering it really a foreign protein, and this may sensitize body-cells in the same manner as in the "indirect anaphylaxis" of Richet, referred to in the preceding chapter, following the second chloroforming of a dog. As was previously stated, anaphylaxis, or rather the anaphylactic mechanism on the basis of the humoral theory, may be considered one of the essential steps in affording resistance to disease or the state of immunity. Broadly speaking, the lesions and symptoms of infection may be ascribed to the effects of soluble toxins, endotoxins, and a protein poison. According to our present knowledge the endotoxins are mainly liberated with lysis or disrupture of the bacterial cell. Similarly, the protein poison is produced by cleavage of the bacterial protein substance. Whether the endotoxins and protein poison are identical it is impossible to state. For the present it may be well to consider them as separate entities. In certain infections, such as tetanus and diphtheria, the soluble toxins are chiefly concerned, and these are neutralized by specific antibodies, the antitoxins. The antitoxins are not similar to the " ferment" that splits protein, because they are able to neutralize their toxins without the aid of complement. In other infections, such as typhoid fever, cholera, and pneumonia, the endotoxins and protein poison may be considered the main etiologic factors. The chief antibodies are a cytolysin (bacteriolysin), which disrupts or kills the bacterial cells, and bacteriotropin, which brings about the same result by favoring phagocytosis. Apparently the cytolysins and the so-called " ferments" responsible for cleaving the protein substance are quite similar in their mechanism. The former are amboceptors, thermostabile and inactive without the presence of a complement. There is no doubt but that heating a serum containing a bacteriolysin and a complement will render the serum inactive through destruction of the complement. While the ferment concerned in splitting protein is regarded by many as an amboceptor and complement, there is no general agreement on this point. Some investigators, for example, believe that the ferment concerned in splitting 1 Jour. Amer. Med. Assoc., 1917, Ixviii, 907. placental protein, as in Abderhalden's pregnancy reaction, is rendered totally inactive by heating the serum. Others ^believe that heating diminishes the activity of the ferment, but does not destroy it altogether; the point cannot be decided at present mainly because of technical difficulties, but, for the sake of simplicity at least, we may regard the protein-splitting ferments as quite similar to the cytolysins; indeed, they may be identical. In anaphylaxis we recognize two primary factors: first, the antibody, which acts with the protein substance, which may be either a harmless sterile protein, such as horse serum or pathogenic bacteria, with the production of anaphylaxis; second, a state of hypersensitiveness of the body-cells. While it is clearly apparent that the protein poison generated in the test-tube may intoxicate normal animals with the first injection, yet to understand the extreme sensitiveness of body-cells in persons susceptible to horse protein, where, for example, a few inspirations of stable air are sufficient to bring on an attack of asthma, we must recognize a peculiar hypersensitiveness of these cells, due probably to the fact that protein amboceptors are attached to the cells and unite with the inhaled protein with great avidity. The relation of anaphylaxis to immunity consists, therefore, in the fact that the mechanism concerned in anaphylaxis is apparently related with that concerned in antibacterial immunity. Vaughan believes that the same mechanism is identical in all forms of immunity, but we cannot subscribe to this view because the mechanism concerned in anaphylaxis does not explain antitoxin immunity, or at least the antibodies concerned in neutralizing diphtheria toxin are different from those digesting or splitting a bacterial protein, as, for example, typhoid bacilli. In antibacterial immunity, however, where the chief action lies in digesting the infecting cells, the mechanism may be regarded as similar with that concerned in producing the anaphylatoxin or protein poison of the humoral theory. The effects are, however, different. In infection we have the combined action of toxins, endotoxins, and protein poison upon the body-cells; in serum anaphylaxis we have the effects of the protein poison alone. Lesions and symptoms of disease, therefore, may be regarded as the summation of the products of infection and anaphylaxis. When we inject a bacterial vaccine we inject so much bacterial protein. This protein sensitizes body-cells and causes them to produce an amboceptor (sensitizer or the anaphylactic ferment); this antibody serves to bring about death by lysis of any corresponding bacteria in the body (therapeutic immunization), or of any that may subsequently gain access (prophylactic immunization). The effects, if apparent, endotoxins, if we consider these as separate from the protein poison. In antibacterial immunity, therefore, we recognize lysis or digestion of the infecting bacteria by an antibody as the chief means of defense. This antibody is produced by previous injection of the bacterial protein in the form of a vaccine, or as the result of a previous infection. This is true also of serum anaphylaxis, or of egg, milk, pollen, or any other form of anaphylaxis, and in this way anaphylaxis is brought into relation with immunity. With the antibody in our body-fluids, the^ corresponding bacterium is destroyed soon after it comes into contact with the antibody, but since the amounts of protein poison and endotoxin released are small and highly diluted, we experience none or but slight effects. If, however, the infection or entrance of bacterial protein is strictly localized to a small area, so that the liberated poisons are concentrated, a local reaction is produced, such as is seen, for example, in the cutaneous tuberculin, luetin, mallein, and similar reactions. The question may now arise as to the manner in which the body cells dispose of, or become accustomed to, or are protected from the protein poison and endotoxin. There is no satisfactory answer to this question. We have seen that repeated injections of the same protein lead to a condition of decreased sensitiveness. The method by which endotoxins and the protein poison are neutralized, and whether antibodies for these are produced, are points that require further investigation. This subject has been discussed in the preceding chapter, under the head of Anti-anaphylaxis. It is true that our body-fluids may contain large amounts of the antibody; that protein, bacterial or other, may be vigorously split, but still we do not suffer from the effects of the protein poison or endotoxins. Whatever the mechanism, it in some manner concerns a neutralization or depression of the susceptibility or hypersensitiveness of the body-cells; either the protein antigen is stored in the cells and in some manner depresses cellular activity, as Weil suggested, or else the protein is split beyond the toxic moiety by the free amboceptor in the body-fluids, and in this manner prevents the protein poison from reaching the sessile receptors (those amboceptors still attached to the body-cells). This reasoning is based upon the assumption that symptoms are produced only in case the poison becomes attached to the cells, according to the cellular theory of anaphylaxis (see the preceding chapter). As was previously stated, if a protein, such as tubercle potein (tuberculin), syphilis protein (luetin), glanders protein (mallein), etc., is concentrated and applied to or injected into the skin or mucous membrane in a local sera, and if the body-cells have been rendered anaphylactic to this protein, a local reaction is produced characterized chiefly by congestion and edema. This local reaction is regarded as analogous to the urticarial or other eruptions accompanying general serum anaphylaxis (serum disease) and is regarded as an anaphylactic or allergic reaction, although there aje not sufficient data at hand to prove that the mechanism of the local or skin reaction is identical with that of the general and severe reaction which may follow an intravenous injection of the protein. Etiology of Skin Reactions. — Skin reactions are conducted by intradermal injection; by application to an abrasion -of the skin; by rubbing into the intact skin or, as on mucous membranes, by mere contact, as instillation into the conjunctival culdesac. In the first and second methods trauma, due to the operation itself, is a factor in the production of the resulting inflammation; likewise the intracutaneous injection of practically any protein or non-protein substance will elicit a non-specific inflammatory reaction providing the dose injected is large enough. I have summarized the probable causes of various skin reactions as follows1: 1. The true anaphylactic skin reaction, a specific process due to the interaction of specific anaphylactic antibody and specific anaphylactogen, largely within or upon the cells and with the formation of a diffusible irritant or the production of cellular shock, capable of producing acute hyperemia, edema, and leukocytic infiltration of the skin. 2. The traumatic and non-specific protein skin reactions which may be caused (a) by trauma and the direct injection of an irritant used as a preservative for the material, as phenol, or, to a preformed toxic and irritant substance, as diphtheria toxin in the Schick test; (6) to the production of a protein poison of irritant qualities b}- the action of non-specific proteolytic ferments in the serum or derived from injured cells, upon the protein of the patient's serum, devitalized cells, injected protein, or all three. The intradermal test has proved the most delicate means of eliciting a local anaphylactic response, but is also more likely to yield the nonspecific and traumatic reactions. Physicians conducting skin reactions should carefully bear in mind the possibility of mistaking a pseudo- or traumatic reaction for the true anaphylactic reaction, and also that 1 Bull Johns Hopkins Hosp., 1917, xxviii, 163. certain drugs, particularly the iodids and bromids, may so favor the non-specific reaction as to present evidences of a violent reaction in normal persons which may be interpreted as anaphylactic (Sherrick,1 Kolmer, Matsunami and Broadwell,2 Kolmer, Matsunami, Immerman and Montgomery3). Anaphylactic Skin Reactions as Indices of Infection and Hypersusceptibility. — As is well known, anaphylactic skin reactions may be elicited in various bacterial and protozoan diseases with anaphylactogens prepared from the protein of the respective microparasites, particularly in tuberculosis, glanders, typhoid fever, and syphilis. Well-marked and specific reactions have also been found by Amberg4 and Kolmer and Strickler in ringworm and favus, and isolated reports show that they may be elicited in various other diseases with the proper preparations. In these conditions, however, the skin reactions are not always elicited, and especially during the early and acute stages. An interval of time is required for the purpose of sensitization, and during the acute stages antigen and antibody may both be present in the cells and body fluids, as shown by Weil5 and Denzer,6 with continual interaction expressed in the symptom-complex of the infection, and thereby giving no response when the protein is applied or injected into the skin. Furthermore, the chemical nature of the protein of our anaphylactogen may ha,ve been altered in the course of preparation to a sufficient extent to fail to elicit an anaphylactic reaction. These and other factors not understood diminish the practical value of a skin test. At present, however, it may be stated that they possess a diagnostic value which is particularly high in chronic infections, and that no other satisfactory clinical or laboratory test for the state of anaphylaxis to a perticular protein and for the anaphylactic antibody has been discovered except that by which the protein is actually brought into relation with the body cells, as in the parenteral introduction of the protein. Of great interest in this connection is the relation of the intensity of the anaphylactic skin reaction to the extent of the infection. Krause7 has recently studied in a thorough and excellent manner the tuberculin skin reaction in relation to experimental tuberculosis, finding that cutaneous hypersensitiveness to tubercle protein is inaugurated by the establishment of infection and the development of the initial focus; that the skin and increased by reinfection. The clinical significance and practical value of skin reactions are largely of a diagnostic nature for the detection of hypersensitiveness to a protein or proteins, which may, when introduced into the organism, produce various acute or chronic lesions and symptoms of disease. Anaphylactic Skin Reactions as Indices of Immunity. — Of further importance is the question of the clinical significance of a local anaphylactic reaction as an index of immunity, that is, resistance to an infection or reinfection. Is the anaphylactic antibody capable of attacking and destroying the antigenic protein in a living state? Are protective and curative antibodies produced by the defensive mechanism of the body while the cells are being sensitized and the anaphylactic antibody is being produced? In other words, is hypersensitiveness to be regarded as an index of resistance? Romer1 and Sata,2 in experiments among cattle with Bacillus tuberculosis, reached the conclusion that a state of hypersensitiveness meant a certain degree of resistance, while Krause3 and Austrian4 have expressed the opinion, based upon experiments, that sensitization of nontuberculous animals with tubercle protein does not raise their resistance to experimental tuberculosis infection, and, indeed, may lower it. More recently Gay and Force5 have greatly renewed interest in this subject by advocating the skin test as a means of determining defensive activity following typhoid fever or active immunization by means of vaccines. Their first work was conducted with a "typhoidin" prepared in the same manner as Koch's old tuberculin by cutaneous inoculation. Later Gay and Claypole6 prepared typhoidin by precipitating the solution with alcohol, washing the precipitate with alcohol and ether, drying in a vacuum, and suspending the resulting powder in phenolized normal salt solution, which was injected intracutaneously and applied cutaneously, a control powder being prepared from broth and used in the same manner. With this skin test Gay and his associates have studied the relative value of various vaccines and regard the anaphylactic reaction as indicative of a state of immunity. Nichols7 has questioned the value of the anaphylactic skin test as an index of immunity and regards the typhoidin reaction as indicating nothing more and less specific than the true immunity to this infection. The experiments of my associates and I1 in this field have been largely tests in vitro for various antibodies, as agglutinins, bacteriolysins, and complement-fixing substances in the fresh sterile blood sera of persons and lower animals hypersensitive to various proteins (typhoid, syphilis, diphtheria, and canine distemper), and have shown that the state of hypersensitiveness to a particular bacterial protein bears no relation to the presence or absence of demonstrable amounts of these antibodies. The experiments of Meyer2 have corroborated our results and conclusions, and have furthermore shown that a positive typhoidin skin reaction in a rabbit does not indicate the presence of resistance to an infection with Bacillus typhosus. The sum total of these studies indicate that although antibodies that may be regarded as possessing protective and curative properties toward a certain protein may be present in the body fluids of persons and animals hypersensitive to this particular protein, the condition of hypersensitiveness in itself is no direct evidence of their presence of resistance to a particular infection, although these antibodies are most likely to be present in the body fluids of those persons who are hypersensitive. The positive anaphylactic skin test is, therefore, evidence of infection or sensitization to a particular protein probably without bearing any direct relation to resistance to infection or reinfection. TUBERCULIN REACTION An account of Koch's discovery of tuberculin, in 1891, is given in the chapter on Tuberculin Therapy. Suffice it to say here that Koch was most interested in the curative properties of tuberculin, and while he has accurately and clearly described the classic picture of the systematic tuberculin reaction,he failed to apprec iate the true significance of the reaction at the site of injection, although its occurrence is carefully noted. ized by three essential features: 1. A constitutional reaction, consisting of fever and the accompanying general symptoms of lassitude, anorexia, and rapid pulse, varying in severity with the intensity of the reaction. These reactions do not by any means run parallel. An intense local reaction may occur, with no or but slight constitutional disturbance. Not infrequently, and particularly in slight pulmonary lesions, signs indicating a focal reaction may not be elicited. Nature of the Tuberculin Reaction. — Koch believed that the tuberculin reaction was due to a summation of the effects of the injected toxin and the toxic bodies formed by the tubercle bacillus within the infected host. Koehler and Westphal, in 1891, suggested that, by a union of the tuberculin with the products of the tubercle bacillus, a third new body was formed in the tuberculous focus. Marmorek, in 1894, suggested that the tuberculin stimulated the tubercle bacilli to secrete a fever-producing substance. Finally, in 1903, von Pirquet and Shick explained the reaction as due to a " vital antibody reaction," and this explanation is the one most generally accepted to-day. According to this conception, an antibodylike substance produced by the bacilli and diffused through the tissues enters into combination with the tuberculin, giving rise to the formation of a toxic substance in the general circulation, as well as at the point of inoculation of the tuberculin, von Pirquet's discovery of the cutaneous reaction, in 1907, was a result of this theory, and served to establish a further analogy between cowpox vaccination, tuberculosis, and the tuberculin reaction. According to the principles laid down in the earlier portion of this chapter, the tubercle bacilli are considered as stimulating the body-cells to produce an antibody or a " ferment" in the nature of an amboceptor, which splits the tubercle protein contained in tuberculin, liberating a protein poison, which produces a general, local, and focal reaction. In terms of the cellular theory of anaphylaxis the effects are due to the interaction of tuberculin and antibodies in the cells (Weil1). The general reaction may be explained as due to a general effect of the poison on body-cells. The local reaction is caused by a concentration of the poison at the site of administration of the tuberculin, and the focal reaction is due to the fact that cells about the lesions are more sensitive to the effects of the poison than are other cells, probably because they are most concerned in antibody production and are supplied with a large number of sessile or attached receptors (amboceptors) for the tuberculin. Specificity of the Tuberculin Reaction. — The tuberculin reaction is highly specific. This does not mean that every case of tuberculosis will give a tuberculin reaction, and positive reactions are occasionally 1 Jour. Amer. Med. Assoc., 1917, Ixviii, 972. found in apparently healthy persons and cattle. The conditions under which a negative reaction may occur in the presence of tuberculosis are, however, fairly well understood, and physicians should be thoroughly acquainted with these. Likewise most instances in which a positive reaction was observed in the apparent absence of tuberculosis have usually narrowed down to the fact that the lesion was so small or so situated as to escape detection, and, indeed, this has been shown so conclusively by autopsies that, in the presence of a tuberculin reaction, on the autopsy must rest the burden of proof and blame. When we realize how small a lesion may produce hypersensitiveness, it will readily be understood how easily the clinician and pathologist may fail to detect the lesion. A large part of our knowledge regarding the specificity of the tuberculin reaction has been gained from veterinary practice, as the results of a test in an animal could immediately be controlled by the autopsy findings. Thus Fraenkel1 collected from the literature 8000 carefully observed instances, and found only from 2 to 3 per cent, of differences between the result of the tuberculin test and of the autopsy. Voges,2 in 7327 instances, noted 2.7 per cent, of contradictions. Kuhnau,3 Bang,4 and von Behring 5 speak of similar experiences. It has long been known that the prevalence of tuberculous findings anatomically far exceeded the number of cases recognized clinically. Among cattle, anatomic tuberculosis is found in from 12 to 25 per cent., and about 80 per cent, or more react to tuberculin. In many of the latter, however, the disease does not progress, but, on the contrary, tends to recede. Similar conditions exist in human pathology. That tuberculosis is very frequent among adults is now well known. The figures of Nageli 6 and Burkhardt7 showed that the increasing frequency of tuberculous infection with advancing years reached over 90 per cent, among those past the eighteenth year; these figures are now well corroborated. Hamburger,8 in the published results of an analysis of 848 autopsies on children, showed that tuberculosis was in evidence in 40 per cent., increasing from 4 per cent, among infants under three months of age to 70 per cent, among children from eleven to fourteen years. This explains, in part at least, the relatively high resistance of children to tuberculin, the difficulty there is said to be in eliciting reactions, and the necessity that exists for using large doses. Usually, when children fail to react, it is because they are not tuberculous or because the lesion is too small, whereas in later years, until adult life is reached, the reaction is observed with increasing frequency and with smaller doses, because the incidence of infection increases progressively from 5 per cent, during infancy to 90 per cent, and over in adult life. The prevalence of tuberculosis, however, by no means indicates that the infected individual suffers ill health or will succumb to the infection. An individual may be enjoying excellent health, and still harbor a tuberculous lesion, and display a marked degree of hypersensitiveness to tuberculin. Such a person is not usually regarded as tuberculous until there are tangible symptoms referable to its existence. It is important to remember that tuberculin is an index of tuberculous infection, and not of disease in a clinical sense. Numbers of persons and cattle reacting to tuberculin remain healthy and do not develop symptoms of disease, the autopsy disclosing the presence of inactive or regressing lesions. In former years it was considered possible to obtain false positive reactions in convalescents and patients in an enfeebled condition who were non-tuberculous, and also in other diseases, such as syphilis, leprosy, and actinomycosis. More accurate anatomic statistics and careful studies of the tuberculin test administered to a large number of individuals, healthy, tuberculous, and sufferers from other diseases, have gradually changed the attitude of the profession and served to establish the high specificity of the tuberculin reaction. Sources of Error in the Tuberculin Reaction. — From the foregoing it will readily be understood that most errors in the tuberculin reaction refer to false negative rather than to false positive reactions. False positive reactions may be observed in leprosy, where the bacillus bears such close morphologic and biologic resemblance to the tubercle bacillus, and it is likewise true that massive doses of tuberculin injected subcutaneously may produce a toxic fever in debilitated individuals, but positive reactions in healthy individuals can usually be ascribed — (a) to a small hidden tuberculous lesion or (b) to a healed tuberculous lesion. As just stated, tuberculin simply indicates hypersensitiveness to the tubercle protein, and this may exist with a very small unimportant lesion, or persist after a lesion has been " healed" to the extent of encapsulation. and remembered. 1. In the final stage of tuberculosis, especially in miliary tuberculosis and in tuberculous cachexia, as in the third stage of pulmonary tuberculosis, the tuberculin reaction may be negative, or be attained only after the injection of very large doses. There is a lessened cutaneous reactivity (cachectic reaction), marked by the appearance of colorless or pinkish spots, instead of an intense papillary eruption. Koch and Ehrlich have explained this by assuming that the tissues had become too thoroughly saturated with tuberculin produced at the infected area to respond to further artificial additions. This condition may be regarded as analogous to a state of anti-anaphylaxis in which we may consider the free and sessile receptors united with the tubercle protein or the cells loaded with the antigen, with depression of cellular activity. findings in nurslings. 3. In small, completely healed lesions, especially in those showing nothing but scar tissue, as in the apex of a lung. In these the antibody and cellular hypersensitiveness have disappeared, and while the lesion may have been tuberculous, one cannot tell anatomically, in a given instance, whether or not hypersensitiveness should have been present. 5. During measles. As von Pirquet and Preisich have demonstrated, the cutaneous reactivity disappears during the first days after the eruption, reappearing after about a week. Greuner showed that the lt Stickreaktion" which occurs after large doses of tuberculin did not disappear entirely, indicating that in measles there is a lessened activity, rather than a total disappearance. 6. Finally, according to von Pirquet, there are a few cases in which we have a minimal reactivity and to which none of the former explanations can be applied. Some cases of active tuberculosis may show only a slight hypersensitiveness, although they are not cachectic. Of course, it can readily be understood that the use of weak or an otherwise unsatisfactory solution of tuberculin and an improper dosage and technic will greatly influence the results. Likewise errors in interpreting what constitutes a positive tuberculin reaction are to be guarded against. This applies especially to veterinary practice. For example, cattle brought from the fields and confined in a stall for the purpose of making a tuberculin test may exhibit a fever for several days without apparent cause. On the other hand, dishonest dealers may force cattle to drink cold water or have given cold water irrigations just before the temperature is taken, preventing the registration of a febrile reaction. Methods of Conducting the Tuberculin Test. — The object of the tuberculin test is to introduce sufficient tubercle protein to react with the tubercle antibody, with the formation of the protein poison, which shows its presence and effects by a general, a local, or a focal reaction or by a combination of these. Various methods have been proposed, of which the following are best known: 1. The subcutaneous tuberculin test is the oldest test of its kind, having been discovered by Koch1 in 1891. It consists in the subcutaneous injection of old tuberculin. A positive reaction manifests itself in a constitutional disturbance, accompanied by fever, a local reaction at the site of injection ("Stichreaction")? and frequently a focal reaction at the site of tuberculous disease. 2. The cutaneous tuberculin test of von Pirquet,2 consisting in the local application of old tuberculin to a superficial abrasion of the skin. A positive reaction is indicated by redness, edema, and other inflammatory phenomena. 3. The conjunctival tuberculin test of Wolff-Eisner3 and Calmette,4 consisting in the local application to the conjunctiva of one eye of a drop of 1 per cent, solution of old tuberculin or purified tuberculin. A positive reaction is indicated by congestion and lacrimation. 4. The percutaneous tuberculin test of Moro and Doganoff,5 consisting in the application of tuberculin ointment prepared by mixing equal parts of old tuberculin and anhydrous lanolin and applying it to the skin over the upper portion of the abdomen or about the nipple. A positive reaction is indicated by an efflorescence of papules upon the anointed skin. 5. The intracutaneous tuberculin test of Mendel6 and Mantoux,7 consisting in injecting into the superficial layers of the skin 0.05 c.c. of diluted old tuberculin. A positive reaction is denoted by infiltration and hyperemia about the site of injection, similar to the reaction to the cutaneous test. tests by a review of the literature, it must be remembered that results will vary according to the portion of the body inoculated, as sensitiveness of the cells varies in different parts of the body, and there are individual differences in various persons that are difficult or impossible to explain. By comparing the figures obtained as the result of different tests upon the same person with the relative frequency of individual tests, Harnmah and Wolman1 have drawn the following conclusions: "1. The intracutaneous and subcutaneous local tests are the most delicate we possess. They reveal practically the full percentage of tuberculosis-infected individuals. Conjunctival Test. "3. There is a definite but not a constant relation between the various tests. An individual reacting to the conjunctival test will, as a rule, give all the others, but not always. The cutaneous or the subcutaneous tests may be negative when the conjunctival is positive. The subcutaneous positive when the cutaneous is negative, etc. Some of the unusual variations may, no doubt, depend upon faulty technic in performing the tests, but all can certainly not be thus explained. Local changes in sensitiveness and variation in the facility of absorption are probably factors, but the exact conditions are not understood. Although the subcutaneous test may be dangerous on account of the harm that may result from too severe focal reactions, yet, when carefully conducted, it is frequently the method of choice, especially in the diagnosis of an obscure pulmonary lesion, and in bone, joint, skin, and other local infections, where the focal reaction may be detected by direct examination. It is to be emphasized, however, that the absence of focal changes during a constitutional reaction does not exclude the tuberculous nature of a suspected lesion. In children, as shown by Hamill, 1 Tuberculin in Diagnosis and Treatment, 1912, Appleton, 167. yield results that are quite similar. The Value of Tuberculin in Diagnosis. — As previously stated, a reaction to tuberculin means essentially that the individual reacting has a tuberculous infection, and in itself means nothing more. Since tuberculin tests disclose inactive and relatively benign tuberculous infections, it has little value, in doubtful cases, in aiding us to decide whether or not the individual has active disease, which clinically is the type of infection about which we are most concerned. Lack of critical discernment in the interpretation of the reaction and its apparent indefiniteness have contributed toward diminishing its diagnostic value. A positive tuberculin reaction is to be regarded as a symptom, or as another link in the chain of clinical evidence, but is not in itself indisputable evidence that a certain lesion is tuberculous, for it can never decide with certainty an otherwise doubtful diagnosis. A similar example is that of a positive Wassermann reaction in a patient with a lesion in the throat; such a reaction does not necessarily mean that the lesion is syphilitic, for the lesion itself may be cancerous, although, coincidentally, a latent syphilitic infection may be present. If tuberculin could differentiate between active and inactive lesions according to the degree of reaction, its value would be greatly increased. While the studies of Krompecker and Romer upon animals indicate that the more virulent the infection the greater the degree of hypersensitiveness, no such fixed relation exists in man. All that may be said is that, in general, the severer the reaction, the more acute the infection. On the other hand, acute miliary tuberculosis or chronic cachectic cases may react negatively. The conditions under which a negative reaction may be obtained in a tuberculous person are to be carefully borne in mind, for if these can be excluded, a negative tuberculin reaction precludes, in all probability, an active or clinically important tuberculous lesion. Tuberculin has, therefore, a higher negative than a positive value in diagnosis. While it is obviously beyond the scope of this volume to discuss the diagnostic value of tuberculin in tuberculous infection of the different organs, I may briefly refer to a few of the more important conclusions reached by individual investigators of large experience in this particular field: 1. In the diagnosis of pulmonary tuberculosis, while a positive constitutional or local tuberculin reaction is never conclusive evidence that a iArchiv. Int. Medicine, 1908, ii, 405. definite pulmonary lesion is tuberculous, a focal reaction, on the other hand, tells definitely of the presence of the disease, and shows, in some measure at least, its extent. In these questionable cases, therefore, the subcutaneous injection of tuberculin finds its most important application, since a definite focal is of more value than a local reaction. Tuberculin may also be of service when the symptoms suggest the presence of a pulmonary tuberculous lesion, but the physical signs are indefinite. Here the focal reaction is likely to be slight and to escape detection, so that one of the cutaneous tests are usually employed. 2. In the diagnosis of bone, joint, and glandular tuberculosis the subcutaneous test is likely to be most valuable, on account of the focal reaction of hyperemia, swelling, heat, and pain about the lesions. The cutaneous test is also valuable, but since this may react on account of the presence of a lesion situated elsewhere, the focal reaction is more conclusive. According to Hamman and Wolman, (a) a focal reaction confirms the diagnosis of tuberculous bone or joint disease; (b) an absence of reaction to the subcutaneous test excludes, with the highest probability, the presence of tuberculosis. 3. In the diagnosis of genito-urinary and pelvic tuberculosis a positive tuberculin reaction is of little value unless the subcutaneous method is employed and the physician is sure of his ability to detect a focal reaction, a proceeding that may be very difficult or indeed impossible. A positive cutaneous test indicates the presence of a lesion somewhere in the body, without disclosing the nature of the renal or pelvic lesion. A negative reaction, however, is of more value, especially when the physician bears in mind the conditions under which a falsely negative result may occur. 4. In the diagnosis of tuberculosis of the eye, ear, and larynx, the tuberculin reaction usually has a limited value, because the nature of the disease can be so readily detected by direct inspection. In tuberculosis of the larynx a focal reaction may be dangerous on account of edema. Similarly in advanced tuberculosis of the ear a focal reaction may lead to extension of the process to the meninges. In these instances, therefore, a cutaneous test should first be made, and if it is found to be negative or inconclusive, the subcutaneous test should be applied with extra caution. 5. In the diagnosis of tuberculosis of the skin tuberculin may occasionally prove of value — especially the focal reaction following subcutaneous injection or a direct local application upon the lesion with a weak dilution, such as a 1 per cent, solution of old tuberculin. 6. In the diagnosis of tuberculosis of a serous membrane tuberculin usually possesses a limited value. In tuberculous meningitis the subcutaneous test is contraindicated, as a focal reaction may do harm. Owing to the acute infection the cutaneous test may be negative, and even if positive, would not aid greatly in the diagnosis because the meningeal condition is always secondary to a primary focus. Tuberculous pleurises, dry or with effusion, and unaccompanied by evident pulmonary disease, are frequently associated with a low-grade tuberculin hypersensitiveness. According to Hamman and Wolman, in a large proportion of cases of pleurisy with effusion the conjunctival test is negative and the cutaneous test but mildly positive. Bandelier and Roepke assert that in a dry pleurisy increased pain and more pronounced and extensive friction may occur during a constitutional reaction to the subcutaneous test and indicate a focal reaction. In tuberculous peritonitis the tuberculin test is frequently negative. A positive reaction has far more value, especially in virulent types of the disease, which come on insidiously with little or no constitutional disturbance. The Value of Tuberculin in Prognosis. — As previously stated, tuberculin may not react in the very early and very late cases of tuberculosis. In patients with rapidly advancing lesions the power to react tends to decrease and frequently is absent. But this condition is apparent without the aid of tuberculin. While Wolff-Eisner and Stadelmann1 laid some stress upon the conjunctival reaction in prognosis, others have been unable to confirm the results, and, as stated by Hamman and Wolman,2 tuberculin fails to yield us information of prognostic value that other methods of clinical observation do not bestow. The Dangers of Tuberculin. — Practically, the only danger lies in the subcutaneous and conjunctival tests. With the subcutaneous test, the greatest danger in pulmonary tuberculosis is the possibility of overdosage, with the production of an extensive focal reaction which may bring on hemorrhage or lead to local extension of the lesion. Because of its very important bearing on tuberculin treatment, the subject will be discussed in the next chapter. The same danger of excessive focal reaction holds for tuberculous meningitis (increased intracranial pressure), in tuberculous laryngitis (edema), and in tuberculosis of the ear and nasal accessory sinuses (extension to meninges) . Regarding the dangers of the conjunctival test, opinions differ. There can be no doubt, however, but that distressing sequelae, such as severe recurring conjunctivitis, phlyctenular conjunctivitis, and corneal ulcers with permanent opacities have resulted from the use of this test. Most of the unfavorable results have followed instillation in already diseased eyes, or of too strong solutions, but this is not true of all cases. As will be pointed out further on, in the first instillation not over 1 per cent, of old tuberculin should be used, and a second instillation should never be made in the same eye for at least several years. Since old people are especially prone to conjunctival inflammation and corneal ulceration, it is probably better to exclude them from the test. Another drawback to this test is the possibility of a "flare up" in the eye following subsequent subcutaneous administration of tuberculin, either for diagnostic or therapeutic purposes. Hamman and Wolman, however, do not consider this dangerous, and have observed but two cases in an extensive experience. THE SUBCUTANEOUS TUBERCULIN REACTION As has been stated repeatedly, the subcutaneous injection of tuberculin is resorted to at the present time mainly for the purpose of eliciting a focal reaction, and, as a rule, this is more easily appreciable when the general reaction is well marked. // tuberculin is used simply to establish whether or not a person is hypersensitive, this fact may be demonstrated by employing much smaller doses, as by the cutaneous, intracutaneous, or conjunctival tests, the patient being spared the discomfort of the constitutional symptoms. Tuberculin Therapy. Manufacturing chemists usually market this tuberculin in a series of dilutions, labeled and accompanied by explicit directions, so that the physician may administer practically any dose desired by injecting so many minims of such or such dilution. Otherwise a series of dilutions are readily prepared in the physician's office or dispensary, according to the method followed by Hamman and Wolman: (a) Seven wide-mouthed bottles of about from 12 to 15 c.c. capacity, and fitted with ground-glass or rubber stoppers, are sterilized, labeled, and numbered from 2 to 8. (6) The diluent is sterile 0.8 per cent, salt solution with 0.25 per cent, pure phenol. This is readily prepared by adding 8 grams of pure sodium chlorid and 2.5 c.c. of pure phenol to 1000 c.c. of distilled water. Dissolve, and filter into one large Erlenmeyer flask or, preferably, into ten smaller flasks. Sterilize in the Arnold sterilizer for one hour, or in the autoclave for twenty minutes, or by gently boiling for fifteen minutes on each of two consecutive days. (c) Into each bottle place 9 c.c. of the diluent with a graduated and sterile pipet. Bottle 1 contains pure tuberculin. To bottle 2 add 1 c.c. of tuberculin and shake carefully; to bottle 3, 1 c.c. from bottle 2 and shake; to bottle 4, 1 c.c. from bottle 3 and shake; continue in this manner to bottle 8, from which 1 c.c. is discarded. (e) These dilutions are usually prepared every two weeks. When not in use, the bottles are kept in a cool, dark place. It may not be necessary to prepare all dilutions. For example, dilutions No. 3 and No. 4 are sufficient for diagnostic purposes, as 0.1 c.c. of No. 4 equals 0.1 mg. of tuberculin and 1 c.c. of No. 3 equals 10 mg., thus affording an ample range of dosage. Method of Conducting the Test. — 1. The patient's temperature and pulse-rate should be taken every two hours for from four to seven days. This is easily accomplished in a hospital; ambulatory patients can usually be readily trained to take their own temperature. All observations should be recorded in writing, and preferably on a temperature chart. The patient's temperature must be constantly below 99° F. before beginning the test, and, if necessary, prolonged rest in bed should be enforced to overcome any existing fever. The test may be given in spite of a daily rise of not over 100° F., but tuberculin by subcutaneous injection should be given only exceptionally to febrile patients. 2. A very careful physical examination should be made, and the results recorded just before and just after the test in order to detect a focal reaction. This is extremely important, for it is our main justification for injecting the tuberculin. below the angle of the scapula, or in the arm. The skin needs no preparation other than to be rubbed with alcohol. The injections are best given during the late evening hours or early in the morning, in order that the temperature and pulse changes may be observed, especially twelve hours after the injection. Records of temperature and pulse should be made every two hours during the day and night for forty-eight hours following an injection. Hamman and Wolman recommend the "Tuberculin Sub 2 Syringe," made by the Randall, Faichney Co. Each syringe should be sterilized by boiling prior to use, and it is recommended that a separate syringe be provided for each dilution. 4. Considerable controversy has arisen over the size of the doses to be employed. Koch's directions called for one milligram at first, then for five, then for ten, and if no reaction followed this dose, it was repeated. There is a decided tendency, however, to use smaller doses. If the object is to establish the presence or absence of tuberculin hypersensitiveness, mild reactions will suffice, and for this purpose small doses repeated or in gradually increasing amounts may be given. If one aims to produce a focal reaction, larger doses and more rapid increase are desirable. Hamman and Wolman advise the following plan for adults : For the first dose, -J- mg. is given. If there is a slight febrile reaction of about one-half a degree, and especially if this is accompanied by a local reaction at the point of injection, the second dose, which is the same as the first, is given at the end of forty-eight hours. The reaction will now most likely be more conclusive. If there is no appreciable reaction after the first dose, the second, consisting of one milligram, is given at the end of forty-eight hours, and the third dose, if one is necessary, consists of five milligrams. Occasionally the third dose must be repeated, or even ten milligrams given if the negative result is at variance with the clinical impressions. 2.5 mg. as the terminal dose. For children under fifteen years of age smaller doses are indicated — an initial dose of one-tenth milligram and a terminal dose of one milligram, with one or two intervening doses. Baldwin has advised 0.05, 0.2, 0.5, and 1 mg. The Reaction. — The constitutional reaction is quite variable. Fever is the most delicate indicator. A rise of 1° F. or more above the previous maximum is considered positive, especially if it is accompanied by a local and a focal reaction. A definite febrile reaction due to tuberculin is rare without the presence of a local reaction to the same or the preceding doses. General symptoms of headache, muscle pains, anorexia, nausea, etc., may accompany the reactions. The local reaction consists of redness and pain at the site of injection, with tenderness of the neighboring lymph-glands, and is absolutely specific of tuberculin hypersensitiveness. The focal reaction consists of an inflammatory reaction with the production of rales, change in breath-sounds, etc. Variety of Tuberculin. — Koch's old tuberculin is used either in one dose of 0.005 mg., or preferably in three different doses injected simultaneously; these will be described further on. Method of Conducting the Test. — The skin of the forearm is cleansed with alcohol and then dried. A small glass syringe fitted with a fine needle is used. A separate syringe is used for the control fluid, consisting of sterile salt solution, and three others for each of the different dilutions used. In performing this test Hamman and Wolman make four simultaneous injections: 2, equivalent to 0.0005 mg. Mantoux uses the last or fourth dose only. The injections are given with the skin held taut or pinched up in a fold between the index-finger and thumb. The needle is inserted superficially, with the aperture directed toward the outer surface of the skin. If the point of the needle is in the skin, a wiiite elevation occurs immediately upon the introduction of the solution; if it is in the subcutaneous tissue, no infiltration is apparent. Cohen1 injects T. R., the first doses being one ten-millionth, one millionth, and one hundred thousandth of a milligram. If these injections provoke no reactions, he repeats the tests with doses ranging as high as ten milligrams. The Reaction. — The reaction consists of infiltration and hyperemia about the site of injection similar to the reaction in the cutaneous test. It appears in from six to eight hours, reaches its maximum intensity 1 Jour. Infect. Dis., 1917, xx, 233. in from twenty-four to forty-eight hours, and usually disappears in from six to ten days. The salt solution generally produces a traumatic reaction, similar to a mild tuberculin reaction, which subsides in forty-eight hours. The reactions are best recorded after twenty-four hours, and the simplest method of recording the results is to measure the width of the area of infiltration of each reacting point. THE CUTANEOUS TUBERCULIN REACTION (VON PIRQUET) Variety of Tuberculin. — Undiluted old tuberculin is now used almost exclusively in conducting the test. Method of Conducting the Test. — 1. The flexor surface of the forearm is chiefly used for making the applications, but it should be remembered that tests performed on different portions of the body are not strictly comparable. 2. The skin is cleansed lightly with alcohol and dried. Three abrasions are made, about lJ/£ or 2 inches apart, with a von Pirquet skin borer (Fig. 126) or with a needle, small lancet, or blood sticker. The object is to scarify the superficial layers of the skin, avoiding as much as possible bleeding, although a few small points of blood should appear. To the upper and lower abrasions add a drop of tuberculin; after ten minutes wipe away the excess with a bit of cotton. No shield or protective dressings are required. The middle abrasion is the control, and shows the amount of traumatic reaction following the scarifying process. Due precautions should, of course, be observed that none of the tuberculin flows down the arm and reaches this spot. The Reaction. — The traumatic reaction as shown in the control area may present an inflammatory areola with, at times, slight infiltration. Before a test may be considered positive its areola should be at least five millimeters wider than the control area. The reactions are usually designated as follows: The usual or normal reaction begins to appear in from four to six hours, reaches its maximum intensity in from twenty-four to fortyeight hours, and then fades rapidly, although the infiltration may persist for some days. Special types of the reaction have been described as follows: The abrasion is being made over the insertion of the deltoid muscle. The borer is held firmly and perpendicular to the arm. A quick rotatory motion serves to remove a circular area of epidermis. 1. The premature reaction, characterized by a rapid course and slight intensity. This type is supposed to occur in patients with manifest tuberculosis who are not doing well. 3. The late reaction, which appears after twenty-four hours and develops and recedes slowly. These last two types are believed to occur in patients having inactive lesions. 5. The scrofulous reaction, which is characterized by numerous small elevated nodules, which may also appear on the extremities and trunk. This reaction is peculiar to children and rare in adults. Variety of Tuberculin Used. — A 1 per cent, solution of Koch's old tuberculin is now generally used, as it is quite reliable, least expensive, and the results that follow its use are more regular than those obtained with purified tuberculin (0.5 to 2 per cent, aqueous solution). Method of Conducting the Test — The conjunctive of both eyes are inspected to ascertain if there is any evidence of disease and if they are strictly comparable in color. The lower lid of one eye is drawn forward to form a little pouch, and the patient is directed to look upward; one drop of a 1 per cent, dilution of old tuberculin is then applied from an ordinary eye-dropper to the lid at the inner canthus. Profuse lacrimation impairs the test, and it is useless to attempt it with weeping or resisting children. If no reaction is apparent and it is still desired to further the test, a drop of a 5 per cent, dilution may be placed in the opposite eye. The Reaction. — In a positive reaction the conjunctiva begins to redden in from six to eight hours, and reaches its maximum in from twenty-four to forty-eight hours, and then rapidly subsides and disappears in from four to six days. In mild reactions the inner canthus is the seat of the most marked changes. Positive reactions have been classified as follows: Precautions. — On account of severe reactions and the danger of inflicting permanent injury on the cornea there is a growing tendency to regard this reaction with disfavor. Hamman and Wolman, however, believe that, with proper precautions, these risks may be minimized, if not completely avoided; they believe, moreover, that the risk in- curred is not great enough to warrant the abandonment of a procedure that has proved itself of such great value in diagnosis. Nevertheless, they emphasize the necessity for observing proper precautions, and give the following rules to be adopted: 4. The test should not be given to manifestly scrofulous children. 5. Skin diseases in which the lesions are situated upon the face, near the eye, especially when these are suspected of being tuberculous, preclude the application of the test. ceration. THE PERCUTANEOUS TUBERCULIN REACTION (MoRO) Variety of Tuberculin Used. — This consists of 5 c.c. of old tuberculin and 5 grams of anhydrous lanolin thoroughly mixed. The ointment retains its potency for many months when preserved in a cold dark place. Manufacturers market the preparation in small collapsible tubes containing sufficient for at least one or two tests. Method of Conducting the Test. — A piece of ointment about the size of a pea is thoroughly rubbed for at least a minute into an area of skin about two inches in diameter over the upper abdomen or near a nipple. The patient may be instructed how to apply this ointment, or the physician may do it himself, protecting the finger with a rubber cot. The Reaction. — This may appear within twenty-four hours, or be delayed for as long as from four to six days. It consists of an eruption of slightly elevated papules situated upon a hyperemic base, which vary in size from a pinhead to large areas of infiltration (Fig. 129). It subsides in from three to ten days. Moro described these grades of reaction as follows: The Intracutaneous Test. The technic for conducting these tests and the reactions secured are quite similar to those just described, and I would refer the veterinary surgeon to these respective descriptions. Differences in technic are confined principally to dosage. The Subcutaneous Tuberculin Test. — This is conducted with Koch's old tuberculin. The method of preparation is given in the succeeding chapter, under Tuberculin Therapy. Concentrated tuberculin is prepared by concentrating the bouillon nitrate to one-tenth its original volume. Diluted tuberculin is the concentrated product diluted to its original volume by mixing 1 part of the dilution with 9 parts of 0.5 to 1 per cent, phenol in sterile normal salt solution or distilled water. The injections are always given subcutaneously hi some convenient area, preferably around the shoulder, which has been shaven and cleaned beforehand with a solution of creolin. The first dose for horses and cattle is usually 0.4 c.c. of concentrated or 4 c.c. of diluted tuberculin; the second dose is usually 0.8 c.c. of concentrated or 9 c.c. of the diluted tuberculin. The Conjunctival Tuberculin Test. — For this test Koch's concentrated tuberculin may be used. Preference is usually given to the purified product, prepared as follows: Mix one part of Koch's concentrated tuberculin with 20 parts of absolute alcohol. The precipitate that forms is filtered off and dried over sulphuric acid. This powder is then made up into a 4 per cent, and 8 per cent, solution in sterile distilled water. Two or three drops of the 4 per cent, dilution are placed in the inner canthus of one eye, to sensitize the tissues. After twenty-four hours, unless a positive reaction is present, two or three drops of the 8 per cent, solution are instilled in the same eye in the same manner. The reaction is usually apparent in from six to twelve hours (Fig. 128). cases where, prior to the test, dishonest dealers have injected tuberculin. The Cutaneous Tuberculin Test. — In making this test some convenient area is shaved and scraped slightly until serum exudes. A small amount of Koch's old tuberculin is applied to the prepared area. In a positive case a well-marked area of congestion and hyperemia appear at the end of twenty-four hours. This may also be accompanied by a rise in temperature. The Intracutaneous Tuberculin Test. — In performing this test from 0.2 to 0.4 c.c. of Koch's concentrated tuberculin are injected into the skin through a fine needle. A white swelling should appear while the injection is being given; if it does not appear, the injection is subcutaneous and unsatisfactory for this test. The appearance of hyperemia and redness with a rise in temperature indicates a positive reaction. The clinical course of syphilis indicates that the infecting microparasite, Treponema pallida, possesses all the qualities essential to the development of an anaphylactic condition in syphilitic patients. Thus the primary lesion appears after an incubation period of two or three weeks. The secondary stage is manifested by periodic waves of various general symptoms; the primary, secondary, and tertiary lesions show a qualitative difference. Stimulated by von Pirquet's discovery of a specific cutaneous reaction for tuberculosis, a number of investigators (Finger and Landsteiner, Wolff-Eisner, Nobe, Ciuffo, Nicolas, Favre, and Gauthier) attempted to obtain a specific reaction for syphilis by applying extracts of syphilitic tissues — prepared from syphilitic fetal liver or chancre — to the skin of syphilitic patients. In spite of some encouraging effects their results were, on the whole, contradictory. Further, Neisser and Bruck found that a reaction similar to that produced with syphilitic extract can be obtained also with a concentrated extract of normal liver. This peculiarity of the skin of syphilitics is ascribed by Neisser to what he calls the state of " Umstimmung" in the later stages of syphilis. Both Neisser and von Pirquet expressed the hope and belief that a reaction may be secured by employing an extract of pallida free from tissue constituents; this was first and finally accomplished by Noguchi,1 in 1911, first with syphilitic rabbits and then with human patients. Noguchi gave the appropriate name of "luetin" 1 Jour. Exper. Med., 1911, 14, 557; Jour. Amer. Med. Assoc., Iviii, 1163. LUETIN REACTION 643 to the extract of pallida. Theoretically, one should not expect to obtain an allergic reaction in syphilis so long as the activity of pallida is maintained at its maximum, or in the very early stages, before there is sufficient time for antibody formation. One can reasonably expect the appearance of the phenomenon when the activity of the microparasite begins to abate through a gradually acquired defensive power of the host, or under an effective therapeusis, as in the later stages of the disease and in hereditary syphilis. Practical results have borne out these theoretic expectations. Preparation of Luetin. — At least six different strains of pallida in pure culture are being used by Noguchi in the preparation of luetin. These are cultivated in ascites-kidney agar for periods of six, twelve, twenty-four, and fifty days, at 37° C., under anaerobic conditions. The ascites-agar cultures are then carefully ground in a sterile mortar, the resulting thick paste being gradually diluted with a fluid culture until a homogeneous liquid emulsion is secured. The preparation is next heated for an hour in a water-bath at 60° C., and then tricresol or phenol added to make 0.5 per cent. Cultures are made from this suspension, and rabbits inoculated intratesticularly ; both, after suitable intervals, must show an absolutely sterile preparation. The luetin should be kept in the refrigerator when not in use. The isolation of Treponema pallidum in pure culture is a difficult procedure, and, obviously, a luetin must be prepared of pure cultures and from as many different strains as possible. While pallida quickly loses its pathogenicity in artificial culture-media and is also highly susceptible to the influence of germicides, its preparation, nevertheless, is an important matter requiring skilful supervision. A control fluid prepared of sterile agar and bouillon in exactly the same manner as luetin was originally advised by Noguchi, but recently he claims that its use is not necessary. Method of Application. — Luetin is not applied to an abrasion of the skin, but is injected intracutaneously with a very fine needle and a sterile syringe. According to directions from the Rockefeller Institute, the luetin is to be well shaken, diluted with an equal part of sterile salt solution, and 0.07 c.c. injected (0.035 c.c. undiluted). A slightly smaller dose, as, e. </., 0.05 c.c., may be used for children. The skin of the upper arm is usually selected as the site for inoculation. If a control fluid is used, the luetin may be injected into the skin of the left and the control fluid into the skin of the right arm, or both injections may be given in the same arm, about two inches apart, the control being above the luetin. As shown by Sherrick,1 and confirmed by my 1 Jour. Amer. Med. Assoc., 1915, July 31, 404. associates and I,1 normal and non-syphilitic persons taking iodids or bromids at the time the skin test is made or while these drugs are still in the body fluids may yield well-marked non-specific reactions which the physician may readily interpret as a positive luetin reaction. After cleansing the skin with alcohol it is drawn taut or pinched up between forefinger and thumb and the needle introduced, with the aperture directed toward the outer surface of the skin. If the point of the needle is in the skin, a white elevation occurs immediately upon injecting the solution; if it is in the subcutaneous tissue, no filtration is apparent. (See Figs. 68 and 69.) A special tuberculin syringe may be used, and the luetin drawn directly into the barrel from the stock bottle and diluted with sterile normal salt solution. To obviate waste and the likelihood of contamination, I dilute a portion of luetin (1 c.c.) with an equal amount of sterile salt solution (1 c.c.) in a sterile vessel, and then add 6 c.c. more of sterile salt solution, shaking thoroughly and placing 0.2 c.c. in each of 30 small sterile ampules, which are then sealed. Before using, the ampule is shaken thoroughly, opened, and the contents aspirated into the syringe; 0.1 c.c. is allowed for waste in loading the syringe and displacing air; 0.1 c.c. is injected, and this is practically equivalent to 0.035 c.c. of the undiluted luetin, the dose recommended. When so prepared, the dilution keeps well, is especially adapted for dispensary use, and the phenol is so diluted as to exclude any traumatic reaction. Reactions. — Normal or Negative Reactions. — In the majority of normal persons the injection of luetin is followed by a very slight traumatic reaction, or a small erythematous area appears, after twenty-four hours, at and around the point of injection. No pain or itching sensation is experienced; the reaction recedes in forty-eight hours and leaves no induration. In certain individuals the reaction may reach a stage of small papule formation after from twenty-four to forty-eight hours, which subsides within seventy-two hours, leaving no induration. varieties : (a) Papular Form. — "A large, raised, reddish, indurated papule, usually five to ten millimeters in diameter, makes its appearance in twenty-four to forty-eight hours. The papule may be surrounded by a diffuse zone of redness and show marked telangiectasis. The dimensions and the degree of induration slowly increase during the following three or four days, after which the inflammatory processes begin to recede. The color of the papule gradually becomes dark bluish red. 1 Jour. Amer. Med. Assoc., 1916, Ixvii, 718; Jour. Lab. and Clin. Med., 1917, xi, 401. The induration disappears within one week, except in certain instances in which a trace of the reaction may persist for a longer period. The latter effect is usually met with among cases of secondary syphilis under regular mercurial treatment in which there are no manifest lesions at the time of making the skin test. Cases of congenital syphilis also show this reaction. "(6) Pustular Form. — The beginning and course of this reaction resemble the papular form until about the fourth or fifth day, when the inflammatory processes commence to progress. The surface of the indurated round papule becomes mildly edematous, and multiple miliary vesicles occasionally form. At the same time a beginning central softening of the papule can be seen. Within the next twentyfour hours the papule changes into a vesicle, filled at first with a semiopaque serum that later becomes definitely purulent. Soon after this the pustule ruptures spontaneously or after slight friction or pressure. The margin of the broken pustule remains indurated, while the defect caused by the escape of the pustular content becomes quickly covered by a crust that falls off within a few days. About this time the induration usually disappears, leaving almost no scar after healing. There is a wide range of variation in the degree of intensity of the reaction described in different cases, as some show rather small pustules, while in others the pustule is much larger. This reaction was found almost constantly in cases of tertiary syphilis, as well as in cases of secondary or hereditary syphilis which had been treated with salvarsan. "(c) Torpid Form. — In rare instances the injection sites fade away almost to invisible points within three or four days, so that they may be passed over as negative reactions. But sometimes these spots suddenly light up again after ten days or even longer and progress to small pustular formation. The course of this pustule is similar to that described for the preceding form. "This form of reaction has been observed in a case of primary syphilis, in one of hereditary syphilis, and in two cases of secondary syphilis, all being under mercurial treatment." Aside from these three types of reactions, there have since been described several cases of the formation of a hemorrhagic exudate, the lesion usually rupturing spontaneously and not running a more severe or a longer course than the pustular. Two such reactions have been reported by Kilgore.1 " Neither in syphilitics nor in parasyphilitics did a marked constitutional effect follow the intradermic inoculation of luetin. In most 1 Jour. Amer. Med. Assoc., Ixii, 1236. positive cases a slight rise in temperature took place, lasting for one day. In three tertiary cases and in one hereditary case, however, general malaise, loss of appetite, and diarrhea were noted." As was previously stated, Noguchi now asserts that the control fluid may be omitted. In syphilitic persons this fluid may give a reaction that is less intense and that is not followed by induration, but is due probably to a true allergic condition, whereas in normal persons none or but a slight traumatic reaction occurs. It may at times be difficult, however, to distinguish a slight luetin reaction from a wellmarked traumatic reaction, and in these instances an opinion may be withheld until controlled by a second injection in the other arm with control fluid. In other words, while the control fluid need not be used routinely, it is well to have it at hand to be used in these doubtful cases. regarded as negative. Results. — 1. The reports of Noguchi and of a number of different observers show that the luetin reaction is generally negative in the primary and secondary (untreated) stages of syphilis. 2. In latent and tertiary syphilis Noguchi has reported positive reactions in from 80 to 95 per cent, respectively, and the reports of others have showed from 64 to 100 per cent, of positive reactions. in from 42 to 80 per cent, of cases. 4. In congenital syphilis the results have varied within wide limits — 10 to 96 per cent, of positive reactions. In cases under one year of age Noguchi has reported about 23 per cent., and among later cases 96 per cent., of positive reactions. 5. While a few observers have reported positive results in diseases other than syphilis, it is frequently very difficult absolutely to exclude syphilis, and the general consensus of opinion is unmistakably to the effect that in this country, at least, the luetin reaction is specific for syphilis. Slight reactions may be obtained in frambesia or yaws and leprosy. Practical Value. — It may be stated in general that the chief value of the luetin reaction is in the diagnosis of those occasional cases of latent, tertiary, or congenital syphilis that fail to react positively with the Wassermann reaction. I am quite convinced that in the majority of cases a negative Wassermann reaction, carefully and skilfully per- formed, and especially with an antigen reenforced with cholesterin, is stronger evidence of the absence of syphilis then is a luetin test. On the other hand, a definitely positive luetin reaction may be regarded as indicating that the patient is or has been syphilitic, even though the Wassermann reaction is negative. 2. Results indicate that in syphilis the luetin reaction persists longer than does the Wassermann reaction. This is to be expected when we assume that the substance in the blood-serum of a syphilitic responsible for the Wassermann reaction, is a separate reactionary product of the body-cells to pallida toxin, the allergic luetin reaction being due to the true pallida antibody. The toxin is believed to disappear from the body-fluids within a few weeks after all the spirochetes have been killed, whereas the allergic antibody may persist for longer periods of time, as it does in other conditions and diseases. In a case of treated syphilis, therefore, showing a persistently negative Wassermann reaction with both serum and spinal fluid, a positive luetin reaction does not necessarily indicate that further treatment is required. 3. Briefly stated, to determine if a frankly syphilitic patient requires further treatment the Wassermann reaction with serum and cerebrospinal fluid is the better test. To determine more definitely whether a given person showing a negative Wassermann reaction has ever had syphilis the luetin reaction is the better and more conclusive test; or if in such a person the Wassermann reaction is positive, the luetin test may be used for control and as corroborative evidence. Mallein is a glycerin extract containing the toxic principles of the Bacillus mallei, the microorganism causing glanders. It is used entirely as a diagnostic agent in veterinary practice, but may also be used for the diagnosis of human glanders, the dosage being the same as that of old tuberculin. Method of Preparing Mallein.1 — A pure culture of Bacillus mallei is usually obtained by injecting a male guinea-pig with infected material, and at the end of twenty-four or forty-eight hours, isolating a pure culture from the testicle. surface. At the end of six or eight weeks the flasks are removed from the incubator and placed in a sterilizer at 100° C. for at least two hours. This process kills the bacilli and extracts the toxic principles. The entire solution is evaporated down to TV of its volume, filtered in small bottles, and sterilized. This is called concentrated mallein, and is kept in this form until ready for use. Before using it is diluted to its original volume with 0.5 per cent, phenol solution, and passed through a porcelain filter. This process removes all the bacilli, and renders the solution aseptic and ready for use. Ophthalmic mallein is prepared by taking one part of concentrated mallein and adding 20 parts of absolute alcohol. This forms a precipitate that is filtered and dried in a desiccator over sulphuric acid. A 5 per cent, solution of the powder is made with sterile water. Subcutaneous Mallein Reaction. — The dose of mallein for a horse is 0.4 c.c. of concentrated mallein, or 4 c.c. or 1 dram of the diluted product. The dose for a retest is 0.8 c.c. of concentrated or 8 c.c. or 2 drams of the diluted solution. Mallein is injected subcutaneously in some convenient area, such as around the shoulder, which has been shaved and cleaned. A positive reaction is based on the same principle as tuberculin, that is, a rise of temperature within twenty-four hours following the injection, with a local inflammatory reaction at the site of injection. Ophthalmic Mallein Reaction. — Two or three drops of the aqueous solution are dropped into the inner canthus of one eye. In case of a positive reaction this is followed by a marked conjunctivitis, associated with a purulent exudate extending from the inner canthus similar to the reaction shown in Fig. 128. In most cases there is also a rise of temperature. Only one dose is to be applied in the ophthalmic mallein test. It is not considered necessary to sensitize the eye, as in tuberculosis. The ophthalmic mallein test has the same advantages as the ophthalmic tuberculin test, that is, one can obtain a reaction when dishonest horse dealers have injected mallein prior to a subcutaneous mallein test, also in cases of far-advanced glanders, which at times give no reaction to a subcutaneous injection of mallein. Bang1 has observed that artificially infected animals reacted with a marked rise of temperature, loss of appetite, and slight diarrhea when injected subcutaneously with a culture of Bacillus abortus, which he had established as the course of infectious abortion of cattle. The English Commission1 prepared and used a glycerine extract of Bacillus abortus in the same manner as tuberculin, and with success; Meyer and Hardenbergh2 have prepared a precipitated purified abortin with which highly specific reactions have been observed; Reichel and Harkins3 have employed an intraderrnal test with a suspension of heat-killed and washed bacilli. The results of these investigations indicate that the abortin test is highly specific; as with other anaphylactic reactions, this test does not serve to differentiate the actively infected from the recovered animals, but when applied to a herd will show whether or not Bang's disease is or has been a source of infection among the animals. In 1907 Chantemesse4 observed characteristic inflammatory symptoms follow the installation of typhoid bacilli extract into the eye of. patients suffering from typhoid fever. Kraus 5 and his associates, repeating these experiments, could not convince themselves of the specificity of this reaction, stating that healthy individuals also give it to some extent, and that other bacterial extracts cause similar symptoms in typhoid-fever patients. In addition he tried a cutaneous reaction, but without result. Zupnik,6 on the contrary, states that a cutaneous reaction is useful, while the ophthalmic reaction is not useful. Deehan 7 obtained a weak to moderate reaction in 12 cases of typhoid fever, whereas eight control cases showed none. Floyd and Barker 8 obtained positive results in 19 out of 30 cases and none in 18 controls, including two cases of paratyphoid fever. Chaufford and Trosier reported unfavorably on the reaction. Austrian10 has reported very favorably upon an ophthalmic reaction in typhoid fever following the installation of " typho-protein " prepared by cultivating a large number of different strains of typhoid bacilli, precipitating the protein with alcohol, drying the precipitate, and re- dissolving in water so that from one-third to one-half milligram is contained in each drop. In typhoid-fever patients reaction of the palpebral conjunctiva of the lower lid and of the caruncle appears on an average of two and a half hours later, reaching the maximum about the sixth hour, and usually subsiding within forty-eight hours. In 75 cases of typhoid fever this test was found positive in 71 and negative in four. In three cases the eye test antedated the Widal reaction, and in only 23 per cent, was the Widal reaction positive at as early a date as the eye test. A study of 190 persons normal or ill with diseases other than typhoid has convinced Austrian of the specificity of the test, and he recommends it as an aid to diagnosis on account of its simplicity and the absence of any discomfort to the patient. More recently, Gay and Force1 have reported favorably upon a cutaneous reaction indicative of immunity against typhoid fever. The preparation which they used, "typhoidin," is prepared in the same manner as Koch's old tuberculin: 250 c.c. of a 5 per cent, glycerin bouillon is inoculated with Bacillus typhosus and cultivated at 37° C. for five days. It is then reduced, without filtration, to one-tenth of its original volume by evaporation over an acetone bath for about eight hours. A control solution of sterile 5 per cent, glycerin bouillon is prepared in the same manner. The skin of the forearm is cleansed with alcohol, and two abrasions are made with the von Pirquet borer, as described under the cutaneous tuberculin test. The "typhoidin" is applied to one cut and the control fluid to the other. The reactions are observed six and twenty-four hours later. Occasionally there is a traumatic reaction in the control, but a positive reaction may be detected by a wider areola and increased induration. Positive reactions were secured in 95 per cent, of cases that had recovered from typhoid fever, two of the cases having had the disease respectively forty-one and thirty-three years before. The reaction was found negative in 85 per cent, of individuals not having typhoid fever. Of 15 persons immunized by the army method, from four and threequarter years to eight months previously, nine gave a positive skin reaction. Twenty-four individuals immunized by a sensitized vaccine (Gay and Claypoole) for from one to eight months previously reacted positively. Later Gay and Claypoole2 prepared typhoidin by precipitating the solution with alcohol, washing the precipitate with alcohol and ether, drying in a vacuum, and suspending the resulting powder in phenolized normal salt solution which was injected intracutaneously and applied cutaneously; a control powder was prepared from broth and used in the same manner. With this skin test Gay and his associates have studied the relative value of various vaccines and regard the anaphylactic reaction as indicative of a state of immunity. Nichols1 has questioned the value of the anaphylactic skin test as an index of immunity and regards the reaction as indicating nothing more than sensitization to typhoid protein, which is apparently less lasting and less specific than the true immunity to this infection. He bases this opinion on the fact that in his experience the typhoidin skin test gave fewer positive reactions (75 per cent.) than generally expected, as about 90 per cent, of persons who have had typhoid fever are immune for many years or even for the balance of life. Furthermore, according to Nichols, experience has shown that protection following typhoid fever is of longer duration than is indicated by the typhoidin test, and while a large percentage of persons who have had typhoid fever or have been immunized with typhoid vaccine react to paratyphoidin, recent experiences and statistics, particularly in Europe, have indicated that these persons are not immune to paratyphoid fever. Kilgore2 has reported favorably upon the value of the typhoidin cutaneous test; Austrian and Bloomfield3 found that the test failed to furnish data by means of which it was possible to differentiate between those who had neither typhoid fever nor had received the vaccine and those who had either had the disease or had been immunized. In our own experience4 powdered typhoidin and its control produced severe reactions when injected intracutaneously in doses of 0.0005 to 0.001 mgm.; these reactions and particularly that produced by the control rendered the reading and interpretation of the test quite difficult and subject to much error. Cutaneous anaphylaxis to typhoidin was found apparently to persist for a longer time among those who have had typhoid fever than among those actively immunized with the vaccine. Among the latter the highest percentage of reactions was found during the first year following immunization. The test was advocated as a means of determining whether or not a person possesses immunity to typhoid fever either acquired by recovery from the disease or by arti- ficial immunization; the sum total of researches by various investigators is to the effect that this skin test is an indication of hypersensitiveness to typhoid protein, but cannot be accepted at present as an indication of immunity (see page 622) . ALLERGIC REACTIONS IN OTHER DISEASES Gonococcus Infections. — In 1908 Irons1 reported general and local reactions in persons suffering from gonococcus infections following the subcutaneous injection of gonococcal vaccines. This reaction has been observed by Brack2 in epididymitis, by Reiter3 in pelvic infections in women, and also by other observers in other conditions. Experiments with glycerin extracts of the gonococcus prepared from several strains, singly or combined in one preparation, have yielded Irons4 well-defined cutaneous reactions. These tests were conducted after the method of von Pirquet's tuberculin test. Diphtheria. — Shick has advocated the intracutaneous injection of a minute dose of diphtheria toxin as a test for antitoxin in the serum of an individual. If sufficient antitoxin is present, the toxin is neutralized and no local disturbances are apparent; otherwise local inflammatory areas may be observed. This test is not regarded as an allergic reaction; a further description of it will be found in Chapter XIV, under Diphtheria (see page 228). Recently Dr. Moshage and I5 have applied an anaphy lactic skin test in diphtheria with a polyvalent antigen designated diphiherin; positive reactions were observed in about 70 per cent, of children and 35 per cent, of adults, and the test was of practical interest mainly from the viewpoint that the anaphylactic reaction may be mistaken for a positive Schick reaction. ALLERGIC REACTIONS IN SERUM AND FOOD HYPERSENSITIVENESS Cutaneous and intracutaneous reactions have been utilized in the diagnosis of hypersensitiveness to horse serum, as in horse asthma, and to the proteins of various foods, as egg-albumen, milk, shell-fish, various vegetables, etc. A cutaneous test for serum hypersensitiveness is described on page 613 and illustrated in Fig. 126. An intracutaneous test may be conducted by injecting into the skin (not subcutaneously) 0.1 c.c. of a 0.1 per cent, sterile solution of the serum. syncrasies are described on page 616. Allergic reactions have also been observed, mostly in experimental animals, in leprosy, sporotrichosis, in diseases due to hyphomycetes, and in pregnancy. Further investigations will, no doubt, disclose reactions of practical value in other diseases, such as rabies, scarlatina, measles, etc., following the successful isolation and cultivation of their respective causative microparasites. AND TREATMENT OF DISEASE WHILE the importance of natural immunity must not be underrated in the protection it gives us after bacterial invasion has occurred, this immunity is, however, usually relative and seldom absolute, and may afford insufficient protection if the invading bacteria are numerous, or particularly virulent, or if the natural resistance of the organism is weakened by fatigue, disease, or injury. Usually the best and most lasting immunity is that actively acquired, in which our own body-cells are stimulated or trained, as it were, to produce specific antibodies against the offensive forces of a particular bacterium or other pathogenic agent. A well-marked and lasting degree of this form of immunity usually follows recovery from many of the acute infections, particularly the acute exanthemata, such as smallpox, scarlatina, measles, typhoid fever, typhus fever, etc. In other infections, such as erysipelas, gonorrhea, and pneumonia, the immunity is less complete, of short duration, or entirely absent, and, indeed, a state of hypersusceptibility may actually follow. It is very important, in this connection, to remember that the degree of immunity is not necessarily in proportion to the severity of the disease; thus a mild infection may be followed by the much-desired immunity, and while in general there is not considerable protection without infection, the latter does not necessarily imply that a virulent infection, or even the actual disease itself, is present, for discoveries have shown that an active immunity may be acquired by inoculation with the antigen so modified or attenuated that it can stimulate the production of specific antibodies without producing the disease or otherwise greatly disturbing the health of the individual. Historic. — The facts here detailed are well illustrated in the history of vaccination in smallpox and the development of vaccine therapy in general. Hundreds of years ago the people of the eastern countries were accustomed to expose their children to a mild case of smallpox in order that a similar mild infection might be acquired and a lasting im- munity thus secured with the least danger to life. This practice, however, was not without risk, as the mild disease not infrequently became a virulent one. Later the dose of infectious agent was decreased by applying the virus to a small abrasion on the skin, and the resulting mild but genuine attack of smallpox usually conferred the much-desired immunity. But here again the severity of the disease was not under control, as the virus occasionally assumed increased virulence and induced severer infections than were desirable. Finally, Edward Jenner observed and showed experimentally (1796) that when cowpox virus is inoculated into the human being, a trivial infection, since called " vaccinia," is induced, and that this is followed by an absolute or nearly absolute immunity of many years' duration against smallpox. In other words, the virus, in its passage through the cow, becomes so modified that it can no longer produce smallpox, but is still able to stimulate the production of the specific antibodies against this disease. Jenner worked so hard to establish the truth of this finding that he had little time to devote to the mechanism involved in the process. In other words, the work of Jenner was largely empirical, and the explanation was not forthcoming until many years later, when Pasteur laid the basis of scientific immunization by discovering that light, high and low temperature, and exposure could so reduce the virulence of a microorganism that while its injection into an animal was practically without danger or ill effect, it could still stimulate the protective mechanism of the host and induce a high degree of immunity. That this could be done was a fact discovered accidentally by Pasteur in 1879 while working with the organism of chicken cholera. After an absence from home he found, on examining his cultures on his return, that they had become innocuous — that hens could bear without any ill effect inoculation of what would formerly have been a lethal dose. The prolonged cultivation of the microorganism had caused its attenuation and Pasteur immediately grasped the far-reaching importance of this discovery. He conjectured that it might be possible to produce a mild and modified form of chicken cholera with a vaccine of the attenuated microorganism which would afford protection to the fowl against the severe form of the disease. This proved to be the case, and established the possibility of so modifying or attenuating the virulence of a virus or germ that, while its administration is not followed by the actual disease, it ts capable of so stimulating the body-cells that the specific antibodies are produced. This discovery formed the basis of prophylactic immunization or bacterin therapy in general. Following this discovery, much work was done, for it appeared that the question of prevention of any bacterial disease simply depended upon whether the bacterium could be cultivated and so modified or attenuated that while its injection would not be followed by disease or other harmful effects, it would be capable of causing the production of specific antibodies. Naturally, most of the earlier work was done with the infections of the lower animals, and, consequently, most discoveries were directly beneficial to them. Pasteur soon devised a method of attenuating anthrax bacilli by exposing them to certain temperatures for varying lengths of time, so that a vaccine could be prepared that has proved of great value. Later the same observer discovered a method of attenuating the virus of hydrophobia by a process of drying, and devised a practical method of prophylactic immunization against this disease. In addition to these his vaccines against swine erysipelas, symptomatic anthrax, and rinderpest have become well known. The knowledge gained from a study of the diseases of the lower animals and the aid given them has been applied to human medicine with considerable benefit, not only in prophylactic immunization, but also in therapeutics (bacterin therapy). The latter application is a more recent discovery, for wnich we are mainly indebted to the researches of Wright, Leishman, Douglas, and their colleagues. Nomenclature. — The word vaccine is from the Latin vacca (a cow). Cowpox was called "vaccinia," or the cow disease, and Jenner designated protective inoculation against smallpox with cowpox virus as vaccination. With true courtesy Pasteur adhered to Jenner's nomenclature and applied the term vaccine to emulsions of dead or attenuated bacteria. This is unfortunate and tends to create confusion, as the term vaccine is inseparably associated with cowpox virus or lymph. The term bacterial vaccine has become widely known, and is used to designate bacterial suspensions prepared for purposes of immunization. There is no essential difference, however, between cowpox vaccine, which contains the modified germ or virus of smallpox in a diluent of lymph, and a bacterial vaccine containing the germ, modified by some physical or chemical agency in a diluent of saline solution or bouillon. It is, however, well to reserve the unqualified term " vaccine" for cowpox virus, and to retain the designation "bacterial vaccine" for suspensions of attenuated or dead bacteria. More recently the term bacterin has been applied to the latter, but this would imply an extract of bacteria, as, e. g., tuberculin, which is not always the case. METHOD OF PREPARING VACCINES 657 Some confusion likewise exists as regards the terms serum and vaccine therapy. Serum therapy is a process of passive immunization induced for either protective or curative purposes by the injection of the bloodserum of another animal that has been actively immunized by inoculation with bacterial toxins or the bacteria themselves, as, for instance, the injection of diphtheria or tetanus antitoxins. Vaccine or bacterin therapy is a process of active immunization brought about by the injection of the bacteria or their products directly into a patient. Bacterial vaccines that are simple emulsions of dead or attenuated bacteria are not, therefore, serums, and the indiscriminate use of the two terms is much to be regretted. Method of Preparing Vaccines. — It may be stated that, in general, the specific microorganism or virus used in a vaccine should be modified as little as possible, or just sufficient to rob it of its disease-producing power. For example, typhoid bacterial vaccine is prepared by suspending the bacilli in salt solution and exposing them to just enough heat to modify them so that they can no longer multiply. The less modification, the better the vaccine. If the exposure is too prolonged or the temperature too high, the vaccinogenic power of the bacilli is destroyed, and the suspension in salt solution is no more potent or of no greater value than the salt solution itself. Therefore the nearer the vaccine approaches the fully viable virus or microorganism, the more potent it will be. The proper preparation of a vaccine, therefore, is the first step to successful vaccine therapy. ways : 1. The living microorganism may be inoculated. This is the ideal method, but for obvious reasons has not been generally used and is still in the experimental stage. It is based upon experimental observations made on the lower animals that an organism may be so introduced as to render it incapable of producing disease, but may, however, stimulate the production of specific protective antibodies. Most work on typhoid fever is at present being done in the Pasteur Institute at Paris. Evidence thus far indicates quite conclusively that the typhoid bacillus is unable to produce typhoid fever unless it is introduced into the gastro-intestinal tract, and the subcutaneous injection of living bacilli, modified only to a slight extent by artificial cultivation, is not followed by ill effects and produces a high grade of immunity. The principle is a good one, i. e., in a vaccine the microorganism should be modified as little as possible. tenuated or modified according to various methods. (a) By passing the virus through a lower animal, as the passage of smallpox through the heifer when the virus is incapable of producing smallpox, although vaccinia confers a specific immunity against smallpox. A vaccine for swine erysipelas is prepared in the same manner (Pasteur) by passing the bacillus through the rabbit several times, which increases its virulence for the rabbit but decreases it for swine. (6) By exposing suspensions of microorganisms to heat. They are usually grown on a suitable solid medium, suspended in salt solution, and exposed to a temperature at or just above their thermal death-point for just sufficient time to kill or attenuate them in so far that they cannot multiply. The same result may be secured by longer exposure to a lower temperature. To secure a potent vaccine the principle of minimum exposure at the minimum temperature should be observed, the question of viability being controlled by culturing the vaccine. Most bacterial vaccines are prepared in this manner. Of course, the fact that a vaccine is sterile could be confirmed by exposing it to a very high temperature, but in this case the product may be of no more value than so much salt solution. Usually an exposure of 53° to 60° C. for from one-half to one hour is sufficient, and only exceptionally are these limits exceeded. in this manner. (d) By desiccating or drying the virus. This is the method of vaccination in rabies, as the virus contained in the spinal cord of rabbits is dried for varying lengths of time, emulsified, and injected. The longer the period of drying, the greater the attenuation, and in this manner the strength of the vaccine and the progress of immunization are under control. (e) By exposing the microorganism to a high temperature for varying lengths of time. Anthrax vaccine, for the immunization of lower animals, is prepared in several strengths by exposing suspensions of the bacilli to 42° C. for varying periods of time. 3. By inoculating with bacterial constituents, as the soluble toxins, bacterial extracts, and products of bacterial autolysis, as in the preparation of Koch's tuberculin T. R., Koch's old tuberculin, mallein, diphtheria and tetanus toxins, etc. In Chapter XIII a method is given for preparing bacterial vaccines, of which typhoid vaccine is a type. Special methods of preparing certain bacterial vaccines and other vaccines, such as cowpox virus and rabies vaccine, are given in this chapter. Mechanism of Active Immunization. — As was stated in the chapters on Immunity, in the presence of an infection the host endeavors to protect itself and overcome the invaders by various means, among which are phagocytosis and the production of more or less specific antibodies that may neutralize the poisons of the parasite (antitoxins), directly kill or destroy them (bactericidans), or so lower their vitality or resistance that they are more easily phagocyted (opsonins or bacteriotropins). During an infection, one or more of these protective forces, or all of them, are brought into action. After the infection has been overcome, the antibodies do not always disappear at once, but remain for some time in the body-fluids and gradually diminish, so that if the host is reinfected with the same parasite, the antibodies are at hand immediately to overcome it and protect the host absolutely, or at least so to modify the pathogenicity of the parasite or neutralize its products that the host will suffer but mildly while the parasite is being finally destroyed. The concentration and duration of the various defensive forces or antibodies vary in different individuals and in different infections, so that the degree and duration of an active acquired immunity are variable factors. Nevertheless — and this is the basis of active immunization— an animal or a person may have specific antibodies for a certain parasite, produced by its own cells, without actually or necessarily suffering from the disease, due to the effects of inoculation with the germ or virus in a modified or attenuated form. The dose of vaccine may be so controlled that general symptoms the result of stimulation of the body-cells are slight or not at all apparent, and, by gradually increasing the dose, more and more antibodies may be produced until a high degree of immunity is secured. 660 ACTIVE IMMUNIZATION plished by the production of antibodies so that they may be at hand to overcome an infection if it should occur. For example, the antibodies specific against the virus of smallpox may be produced by inoculation with cowpox virus, so that for years the system will be protected against smallpox. Even if vaccination has been delayed until smallpox has actually been contracted, inoculation with cowpox virus early in the period of incubation so stimulates the body-cells that sufficient antibodies are produced to modify and lessen considerably the virulence of the smallpox virus. This is especially true in rabies, when the vaccine is given in such doses and at such intervals that sufficient antibodies are produced to neutralize the effects of rabic virus and actually to destroy it during the period of incubation or during the interval that elapses between the time of infection and the appearance of the symptoms. In this way the great majority of infected persons escape the sufferings of rabies by enduring the relatively slight discomfort consequent to a series of subcutaneous injections. (b) For the treatment of disease. This is the bacterin or vaccine therapy, a method that owes its origin to the researches of Sir Almroth Wright and his colleagues. It was originally employed in the treatment of those infections that showed a tendency to chronicity in which true toxins played little or no part. Since recovery from an infection is in general dependent upon the mechanical removal of the infecting agent, aided by antibodies that facilitate phagocytosis or directly destroy the invading bacterium and neutralize its products, Wright believed that in chronic infections autovaccination, or stimulation of the body-cells to the production of antibodies, by reason of the fact that it is irregularly timed, is generally insufficient or altogether absent. For these reasons he believes that any stimulus that will arouse the body-cells to throwing into the circulation substances from the invading bacterium or diseased tissues, may result in increased antibody formation, followed eventually by clinical improvement or cure. In certain cases this stimulation may be secured by judicious massage or manipulation of the diseased part, by passive hyperemia (Bier), or by similar procedures. However, if the microorganism is obtained and cultivated artificially, it is possible, in many instances, so to modify or attenuate the bacilli (usually by heat) that they may be reinjected into the patient in sufficient numbers to furnish the stimulus necessary for arousing dormant or uninvolved body-cells to produce the opsonins and other antibodies necessary for overcoming the infection. In other words, with each in- fection the host endeavors to protect itself by producing antibodies. When the protection is insufficient, the infection will spread; when the antibodies are in excess, the infection is overcome; when the forces are about equal, a stage of chronicity may result in which the host becomes accustomed, as it were, to the invaders, and, while the infection does not spread rapidly, it does not, on the other hand, recede. In cases of the latter type an extra dose of bacterial stimulant (a bacterin) may arouse dormant or inactive cells to furnish an extra quantity of antibodies and thus turn the tide. In acute infections indifferent groups of cells may likewise be brought into action, although it is more likely that they are already involved, so that the extra stimulation in the form of bacterin must be cautiously and carefully applied, if applied at all. In therapeutic inoculation, therefore, the fundamental principle is to stimulate in the interest of the infected tissues the unexercised immunizing capacities of the uninfected tissues. This is especially true hi chronic infections, when the use of a bacterial vaccine may be likened to the application of the whip to a lazy horse that is capable of further effort and work. In acute infections, however, while the cells are at work they may be capable of greater effort, but vaccines should be given cautiously, as they may, to use the same simile, act as a whip to a willing and well-worked horse that is unable to respond or does respond, with resulting disastrous overexertion. It should be remembered, in this connection, that usual forms of treatment should be given while bacterin therapy is being instituted. For instance, it is useless to administer a vaccine to a patient with a suppurative fistula or sinus if an infected silk suture is directly responsible for the suppuration. The suture should be removed, if possible, and after this is done, a vaccine may be of considerable aid in overcoming the coincident infection. In what manner can dead bacteria cause the production of antibodies? The mechanism is similar to that involved during infection with the living microorganism, and involves the first principles of immunity. The antigenic powers of a vaccine are probably always more or less inferior to the living antigen, as some principle may be lost during heating, drying, passage through animals, the action of germicides, etc. For this reason living vaccines are to be preferred, although, for obvious reasons, they cannot generally be employed in human practice. Just what portion of the bacterial cells is mainly antigenic it is difficult to determine, for it probably varies with different species. With a true toxin, as, for example, the diphtheria bacillus, the toxin constitutes the main principle, and causes the production of an antitoxin as its main antibody; with other bacteria, such as the typhoid bacillus, a soluble toxin and an endotoxin in combination with the protein of the bacterial cell are probably the main antigenic factors responsible for the formation of a bacteriolysin, opsonin, antitoxin, agglutinin, etc. In brief, the antigenic principles of a microorganism are mainly thermostabile and fairly resistant substances, so that a bacillus may be so attenuated or altered that it cannot multiply or produce disease, and yet is capable, through the agency of substances that have escaped destruction, of causing the production of specific antibodies. As was previously stated, vaccines may cause the production of different antibodies. As curative agents, however, it would appear that they are most efficacious in those infections in which phagocytosis is known to be chiefly concerned in the defense of the host, e. g., in staphylococcus infections. As shown by Wright and Douglas, Neufeld and Rimpau, a bacterial vaccine facilitates phagocytosis, not so much qualitatively or quantitatively as through the production of specific substances that act directly and primarily upon the bacteria and render them more vulnerable to phagocytosis (opsonin or bacteriotropin). Wright has advised a method of opsonic measurement, previously described, for measuring the immunity response, but, as will be understood, while the opsonin may be the chief antibody, it is seldom if ever the only one, so that the opsonic index is but one measure of defensive power. According to Vaughan, a microorganism is directly responsible for the production of a specific proteolytic ferment capable of causing the disintegration or destruction of the bacterial cell and its products. The ferment is the antibody, and is produced during an infection or by a vaccine in just the same manner as antibodies in general are produced. In other words, Vaughan regards antibodies as of the nature of proteolytic ferments; thus the protein of the microorganism composing a vaccine produces a specific proteolytic ferment capable of overcoming its substratum when it meets the latter in the form of the invading microorganism of an infection. For example, the tissues affected may be unable to produce a sufficient quantity of the specific ferment necessary to overcome the infection. The injection of bacterial protein in another and healthier part of the body leads to the production, in this locality, of a specific ferment that is conveyed to the diseased area by way of the circulatory system, and aids in destroying the protein of the infecting microorganism and its tissues. The Non-specific Activity of Bacterial Vaccines. — Owing to the weight of laboratory investigations and the fundamental laws of specificity in immunity reactions, the sole efficacy of a bacterial vaccine has been generally ascribed to the production and activity of specific antibodies, and any deviation from this current of thought has been received with a measure of skepticism and disapproval. Scattered throughout the literature are the reports of more or less isolated observations that in the treatment of infections, both acute and chronic, good results have followed the use of non-specific substances. The subject has been recently studied and developed, particularly by Jobling and Petersen.1 The favorable results first reported by Krause,2 Ichikawa,3 and others by the intravenous injection of typhoid vaccine in typhoid fever were soon followed by the further reports of Kraus, of Luedke,4 and of Miller5 that equally good results could be obtained with other substances, such as colon vaccine, or even with solutions of proteins, albumose, etc., in this infection. Mueller and Weiss,6 and Saxe, Bruck, and Kiralihyda7 have obtained striking results in arthritis, especially gonorrheal arthritis, by the intragluteal injection of sterile milk and of sodium nucleinate, both of which substances cause a marked reaction. Smith8 calls attention to the value of an anaphy lactic reaction in gonococcus infections obtained with horse serum, normal or antigonococcic, it matters not, provided the allergic phenomenon is manifested. Miller and Lusk9 report striking results in acute, subacute, and chronic arthritic conditions of various types by intravenous injections of typhoid vaccines and proteose. It is probable that the beneficial results occasionally reported in the autoserum treatment of various skin diseases may be due to the same non-specific mechanism. In the mechanism of the non-specific activity of vaccines Jobling and Petersen have mentioned (1) the probable selective stimulation of the hematopoietic tissues by the non-specific stimulus, resulting in the production of specific antibodies; (2) the production of hyperleukocytosis; (3) the production of fever; (4) the mobilization of proteolytic and lipolytic ferments, and (5) an increase of antiferment. Furthermore, it would appear that in many cases vaccines have a 1 Jour. Amer. Med. Assoc., 1916, 66, 1753. 2 Wien. klin. Wchnschr., 1915, xx, 29. 3 Ztsch. f. Immunitatsf., orig., 1914, xxiii, 32. 4Miinch. med. Wchnschr., 1915, 62, 321. 6 Jour. Amer. Med. Assoc., 1916, Ixvi, 1756. tion and tending at the same time to increase body weight.. It is apparent, therefore, that the administration of either an autogenous or stock bacterial vaccine may produce beneficial results not only through the production of specific antibodies but also by means of certain general and non-specific agencies. To secure these results sufficiently large doses must be given. It is well known that we possess general defences against infection, and it is entirely logical to assume that these are operative in combating disease and may be subjected to stimulation and increased activity. In my opinion we should still prefer the use of autogenous vaccines, increase their immunizing powers by more attention to the technic of their preparation, and adhere to our belief in their probable specific effects, while realizing that their administration may also stimulate non-specific agencies of therapeutic value. Further investigations are required to produce safe and satisfactory preparations of some protein adapted for this form of therapy if the non-specific activity of some protein is alone desired. In this form of therapy with non-specific bacterial vaccines, typhoid vaccine has been generally administered by intravenous injection. Some reaction is apparently necessary for therapeutic results, but severe and undesirable reactions may be produced with marked rise in temperature, severe headache, and chill. If this form of therapy is employed the physician should very carefully consider the possibility of these severe reactions following an injection and the ability of the patient to withstand them. Small doses of typhoid vaccine, as 40,000,000 to 70,000,000 bacilli, should be selected for the first injection if given intravenously, with a gradual increase until some fever and leukocytosis result. Subcutaneous injections with larger doses may be tried, as they are safer but slower in action. The usual forms of therapy and particularly the removal or treatment of foci of infection should receive careful attention. Until this form of treatment is better understood and a purified protein provided in standardized dosage^ the physician should exercise extreme caution, and particularly with intravenous injections. Living versus Dead Vaccines.— Barring accidents, the employment of a living virus is the most certain way of calling forth a maximum output of antibodies. There is at present no satisfactory explanation for this except that heat-labile substances destroyed in the ordinary preparation of bacterial vaccines have antigenic properties (Smith). Living vaccines are also capable of penetrating into deeper tissues, whereas dead vaccines may remain where they are deposited. Similarly living viruses are capable of exerting a continuous action and of de- AUTOGENOUS VERSUS STOCK BACTERIAL VACCINES 665 livering an infinite number of blows, whereas the injection of a dead virus produces an interrupted action and deals but a single blow. The actual dangers of using a living vaccine, as the possibility of it being too virulent and thus producing disease, or of regaining virulence or producing chronic "carriers" preclude their general employment in human practice. Sensitized Vaccines. — Besredka and Metchnikoff1 have suggested a plan of injecting a vaccine composed of living bacteria that have been immersed in their specific immune serum or, in other words, have been sensitized (serobacterin). They believe that such vaccines produce practically no negative phase, but only slight local and general reaction, and that the general response with antibody formation is facilitated. This principle is supported by the observations of Theobald Smith, who found that the experimental injection of a toxin-antitoxin mixture aids the dissemination of the toxin through the body quite generally, whereas the pure toxin is chiefly held at or near the place of injection. This diffusion tends to cause maximum antibody formation over an entire portion of the body by a relatively small amount of free or easily dissociated toxin in the toxin-antitoxin mixture. Smith inclines to the belief that a similar phenomenon of diffusion may occur with sensitized dead bacteria. In addition, the specific immune serum may aid in the disintegration of the bacterial cell, either through the attachment of a bacteriolytic amboceptor that would tend to lyse the bacterium with a complement of the tissues, or through a preliminary action of opsonin which prepared the bacterium for ultimate destruction and liberation of antigenic principles. Autogenous versus Stock Bacterial Vaccines. — It may be stated in general that autogenous vaccines, i. e., those prepared from the patient's own bacteria, should be used whenever possible, especially in the vaccine treatment of disease. To be successful, vaccine therapy demands that the bacteria be as little changed as possible. Before they are killed, the bacteria should be endowed with as many of the potencies as possible with which they maintain themselves in the body. As these potencies do not remain unchanged during artificial life, as the loss of capsules, loss of virulence, etc., it is advisable to secure the organism causing the infection as quickly as possible and prepare a vaccine without undue delay. Variants may occur among cultures of the same species, and the injection of one strain may not protect against another, as shown by 1 Ann. de Tlnst. Pasteur, 1913, xxvii, 597. risk of using an alien species or a different strain is reduced to a minimum. In some cases the difficulty of securing and of identifying the infective agent may be so great that much time is lost in preparing autogenous vaccines, as, for instance, in gonorrheal and tuberculous infections, and in such cases it may be necessary to use a stock vaccine. In protective immunization stock vaccines are used, as, for instance, in the preparation of typhoid vaccine. In certain instances, as in gonococcus and tuberculous infections, stock vaccines possess but slightly inferior therapeutic value as compared with autogenous vaccines, not to mention the delay and difficulty in cultivating and preparing autogenous vaccines. In many other infections, as with the Bacillus coli and gtreptococci, stock vaccines possess little or no value. The wholesale manufacture of various bacterial vaccines and their indiscriminate use have brought disappointment to many. Rational and scientific vaccine therapy does not consist in the administration of ready-made, uncertain, and oftentimes hit or miss mixtures, recently so widely exploited. Especially is this true in the use of vaccines for therapeutic purposes. The bacteriotherapeutisjt must possess sufficient skill to enable him to make bacteriologic diagnoses, prepare autogenous vaccines, and skilfully guard their administration. In most instances these requirements are fulfilled by cooperation between the clinician and bacteriologist, or, better, by one who is especially trained in vaccine therapy. The Negative Phase. — As has been stated in a previous chapter, certain local, constitutional, and focal disturbances may follow the injection of a bacterial vaccine. The first or local symptoms are not infrequently due to an excess of preservative in the fluid or to the presence of contaminating microorganisms, but abscess formation is distinctly rare. I, in common with others, prefer to find slight focal and constitutional symptoms following the first one or two doses of vaccine. In furunculosis, for instance, when the old lesions discharge a little more and one or two others threaten to develop during a day or so following the injection of vaccine, I feel assured that the ultimate result will be good. These reactions are particularly desirable for the non-specific effects of a vaccine. In tuberculin therapy, however, the trend of opinion is very much in favor of administering doses so small that no appreciable focal or constitutional lesions will follow. Both the pathologic a -id the immunologic process concerned in tuberculosis are somewhat different, and in ordinary bacterin therapy a slight focal disturbance is desirable CONTRAINDICATIONS TO ACTIVE IMMUNIZATION 667 and indicates that the vaccine in question possesses some potency. Allen, who has an exceptionally rich experience in vaccine therapy, frequently mentions the desirability of administering doses sufficiently large to evoke slight reactions. Following the administration of a vaccine it is believed that the quantity of opsonin in the body-fluids is temporarily decreased, and that the inoculated person is, therefore, more susceptible to infection (negative phase) (Fig. 56). It can readily be understood how a vaccine may temporarily depress the cells and defensive mechanism in general, but just how it may bring about an actual decrease in opsonin it is more difficult to understand, as the actual amount that may be used in dealing with the vaccine itself must be small. Veterinarians are careful not to expose cattle to infection immediately after they are immunized with anthrax vaccine, on account of this hypersusceptibility to infection. In general, however, I have observed that most immunizators are prone to regard the question lightly, and to neglect the importance of the negative phase, whereas some deny that it ever exists. Contraindications to Active Immunization. — It should be emphasized that a properly prepared vaccine is a potent substance capable, when given in excessive dosage or when otherwise injudiciously administered, of doing much harm. A vaccine stimulates body-cells, and unless the cell can withstand the stimulation, the administration of vaccine may do actual harm. This is the main reason why vaccines should be used very cautiously, if at all, in the treatment of severe generalized infections. In passive immunization the conditions are different, as the body-cells are not taxed, but rather, through the neutralization of the toxic substances which they are combating, they are relieved, and an antibodyladen serum may, therefore, be freely administered in severe infections. In active immunization for therapeutic purposes the conditions should be carefully weighed and the treatment conducted by one who is qualified to judge of the potencies of harm and good in a vaccine, and who has had sufficient experience to guide him in dosage and frequency of inoculation, the main objects being to tide over and aid nature during an acute infection, and to arouse and stimulate her during a chronic infection. In prophylactic immunization the physician should satisfy himself that the patient has no latent or active infection that may be rendered worse during the temporary depression that follows inoculation. It is true that this depression is fleeting and temporary, and that the possible harm incurred may be far outweighed by the ultimate good, but vac- cines should be given with proper discernment and riot carelessly and injudiciously. These remarks have no relation to cowpox vaccination, where the good so far overbalances the possible harm that in general all persons should be vaccinated, especially if an epidemic is impending. (a) Tuberculosis. — There is at present some discussion relative to the harm that may be caused in tuberculosis by typhoid immunization. Probably all will agree that a patient with an active and acute tuberculous lesion should be refused inoculation, but when the lesion is quiescent or healed, or in the early latent stage, it is indeed difficult to understand how a prophylactic dose of typhoid vaccine will do more or as much harm as an attack of tonsillitis, rhinitis, or some similar acute infection. SMALLPOX Historic. — Just when and where smallpox vaccination was first practised is not known. The original method of inducing immunization against the disease by introducing the virus from a smallpox patient into a healthy person through an abrasion of the skin and thus greatly diminishing the virulence of the disease was practised by the Turks during the eighteenth century, the chief object being to preserve the beauty of the young Turkish and Circassian women. In 1878 Lady Mary Montagu, the wife of the British Ambassador at the Ottoman court in Constantinople, observing this practice among the Turks, had her own son and daughter inoculated and was largely instrumental in establishing the practice in Europe. As regards the prophylactic value of this method of inoculation in England and continental Europe, statistics are incomplete, but the literature of contemporary writers shows that protection was usually complete. The induced disease was not, however, always mild, and not infrequently assumed an unexpected virulence that not only proved distressing and even fatal to inoculated individuals, but also constituted a source of infection to a community. While, therefore, the underlying principles were sound, and while these early attempts at preventive immunization mark an epoch in the history of medicine and of the world, PROPHYLACTIC IMMUNIZATION OR VACCINATION 669 it was not until Edward Jenner made his investigations into a theory held by farmers and by experimental evidence established it as true that a satisfactory method of immunizing the body against smallpox was introduced. The peasantry in various parts of Europe, and especially in England, had generally observed that those who had had sores on their hands contracted from similar lesions on the teats of cows, usually escaped smallpox infection when the disease was epidemic in a community. In fact, it is said that several farmers deliberately inoculated members of their family with cowpox lesions and that these escaped smallpox. Edward Jenner was a physician practising in Berkeley, Gloucestershire, and frequently used the method of direct inoculation from a mild case of smallpox among his patients. While a student he was impressed with the traditions of cowpox vaccination, and finding that they were largely true, determined to make experimental tests. On May 14, 1796, he vaccinated a boy, James Phipps, with virus from a cowpox lesion on the hand of a dairy maid, Sarah Nehnes, and on July 1st he inoculated the same boy with pus from a smallpox patient without resulting infection. In 1798 he furnished further proof that cowpox will afford protection against smallpox by inoculating a child direct from a vesicle on the teat of a cow, and continued the inoculation from arm to arm through a series of five children, after which all were inoculated with smallpox virus, without a single case developing. In the same year he published "An Inquiry into the Causes and Effects of the Variolse Vaccine/' illustrated by four plates, and within a year or two vaccination became general over Europe. Vaccination was introduced into the United States in July, 1800, by Dr. Benjamin Waterhouse, Professor of Physic at Harvard University, who vaccinated his own children. At about the same time John Redman Coxe, of Philadelphia, vaccinated his oldest child and then tested the experiment by exposing him to cases of smallpox. This bold repetition of Jenner's experiment considerably strengthened public confidence in the method and the practice spread rapidly. Thomas Jefferson, writing in 1806 to Edward Jenner, said: "Future generations will know by history only that the loathsome smallpox existed and by you has been extirpated." But Jenner and his earlier supporters met with much opposition, often bitter and unrelenting, and this is readily understood when it is realized that even at the present day, over a hundred years later, cowpox vaccination still has its opponents, in spite of the fact that the value of the method has been established, and it has been found the greatest of all boons to the human race, and notwithstanding that it has been definitely proved that a thorough and continuous practice of the operation would quickly eradicate smallpox from the face of the earth. This opposition is especially pernicious and unjust, since the practice of former years of vaccinating by direct transmission from arm to arm has been entirely abandoned, and that animal lymph, prepared and collected under strict aseptic precautions, is being used exclusively. The Relationship of Variola and Vaccinia. — The relationship of variola to vaccinia has been discussed since Jenner's time, but no adequate explanation has been found. According to the general belief the smallpox virus, whatever it may be, is altered in its passage through a lower animal, and loses forever its power of producing smallpox, but is still so closely related that the antibodies it produces are sufficient to protect against smallpox. The close interrelationship existing between vaccinia and variola is shown by the presence in the virus of both, and in section of the skin of both, of microscopic cell inclusions, first described by Guarinieri in 1892. This finding has been confirmed by Pfeiffer in Germany and Councilman and his associates in this country. These investigators have made extensive studies of these bodies, and believe them to be protozoa intimately associated with the etiology of vaccinia and variola. More recently, Fornet has described certain small, diplococcus-like bodies that were found in cowpox vaccine and in smallpox lesions. These are regarded as having an etiologic relationship to smallpox, and if these findings are confirmed, would prove the identity of variola and vaccinia. Recent investigators, particularly Copeman, erf England, and Brinkerhoff and Tyzzer, of America, have shown, by carefully conducted experiments, that vaccination will protect monkeys against subsequent inoculation with smallpox virus, and this completely confirms the early experiments of Jenner and others who proved the efficacy of vaccination by the "variolous test." The Preparation of Cowpox Vaccine. — During the early days of vaccination it was customary to inoculate human beings with material obtained from the pustules of those previously vaccinated. The oldtime physician carefully removed choice scabs and carried them about in a special case ready for inoculation. While this method served its purpose well, there were several drawbacks to its use, the chief of which was the danger of transmitting syphilis. It has now for many years been the custom to use virus obtained from animals, the production of which can be carefully controlled and tested, any danger of transmitting syphilis being thus obviated, because the heifer or cow used in the preparation of the virus is not subject to this disease. The opponents to vaccination, however, persist in using old and obsolete statistics regarding the transmission of syphilis to support their claims, although these have absolutely no bearing upon the modern methods of preparing the virus. Seed Virus. — This refers to the virus for vaccinating the calves or other animals used, and is a most troublesome factor to those engaged in this work. According to Park and Huddleston, a sufficient amount of vaccine virus should be on hand to vaccinate from 40 to 50 persons. Five children in good health and not previously vaccinated should then receive an inoculation, each spot being of the size of a ten-cent piece. On the fifth day after vaccination the upper layer of the resulting vesicle should be removed, and sterilized bone slips be rubbed on the base thus exposed. From 100 to 200 slips on each side of the slip may be charged from each child. The slips should be allowed to dry for a minute, and should then be placed in a sterilized box and preserved in cold storage, where they will remain active for at least two or three weeks. The aforenamed observers now use rabbits alternately to obtain seed virus. Subsequent animals are vaccinated with any one of three vaccines — (1) Slips charged from typical vesicles of a calf; (2) slips charged with the serum from a calf after removal of the vesicles; (3) the glycerinated virus may be used to vaccinate succeeding calves, but in this case it is necessary to keep the glycerinated virus for two or three months, since the use of fresh virus on a succession of calves leads to prompt degeneration of the vaccine and to the production of infected vesicles. The New York Vaccine Laboratory produces a virus that is never more than four successive transfers from a human case of vaccinia, and is guaranteed to give 100 per cent, of "takes" in primary vaccination. Animals. — Various animals have been used, but female calves from two to four months of age are preferable. Older animals may be used, and in several European institutes cows are usually employed. With properly constructed operating-tables, they may be handled with comparative ease. Rabbits have also been used, especially in propagating the seed virus and to obtain pure and highly active viruses. The calves are kept under supervision for at least a few days. In some institutes they are tested with tuberculin, although with good veterinary inspection this test is not necessary. Soon after admission feet and the tail. On the day before vaccination is to be performed the belly-wall is cleanly shaved from the cuneiform cartilage to the pubis, and well up on the inner sides of the thighs and the flanks. The skin is then thoroughly washed. Just preceding the vaccination the animal is fastened to the operating-table and the abdomen and inner surface of the thighs prepared as for an aseptic abdominal section, i. e., a thorough scrubbing with hot water, green soap, and soft brush, followed by alcohol and sterilized water, the parts being then dried with a sterile towel. All other parts are covered with sterile sheets, and the calf is now vaccinated under aseptic precautions. Vaccination. — About 100 small scarifications are now made in these areas, preferably by cross-scratches or in rows of lines about one to two centimeters square and at least one to two centimeters apart. The scarification is simple, but usually brings a small amount of blood. After they have been made, they are mopped with sterile gauze and rubbed with the charged slips, using one or two slips for each small area, depending on the amount of virus each slip contains. The lesions are allowed to dry, and are then covered with sterile gauze or a simple protective paste, or are left entirely uncovered. Precautions should be taken to keep the animals as clean as possible. Inoculated animals are to be kept in stalls or stables apart from those under observation. The stable should be so constructed that the floors can be flushed daily with a hose and hot water. Excreta should be removed promptly. No bedding is permissible, and means should be provided for fastening the legs and preventing the animal from kicking the scarifications. Collection. — Ordinarily, within forty-eight hours of vaccination, the scratches are pinkish, slightly raised, and papular, and within five or six days, depending upon the rate of development of the vaccine vesicles, the virus should be ready for collection (Fig. 131). The calf is killed and placed upon the operating-table. The appointments of the operating-room are usually equal to those in a well-equipped hospital operating-room, being supplied with all conveniences and means for carrying out a careful, painstaking, and aseptic technic. The exposed parts are covered with sterile sheets. The operator and his assistant are clad in aseptic gowns. The vaccinated field is thoroughly scrubbed with soap, sterile water, and gauze, and mopped with sterile gauze. After the curetage, serum exudes from the excoriated base of the vesicle, and ivory tips may be charged in this. The sticky and pulpy exudate is then mixed with four times its weight of glycerin and water (50 per cent, glycerin, 49 per cent, water, 1 per cent, phenol), and this is done most effectively by passing the mixture between the Note the lines of cowpox lesions over the abdomen and flanks of the calf. The surgeon is about to cleanse this area in a thorough and careful manner, after which the cowpox material is removed with a curet and collected in a sterile vessel. All precautions are taken to insure as thorough aseptic technic as possible. rollers of a Doring mill. The glycerinated pulp is allowed to stand for three or four weeks in order to allow bacteria, which are invariably present, to undergo dissolution. At the end of this time the glycerinated pulp is thoroughly titrated in specially constructed triturating machines, and put up in small capillary tubes, which are sealed, or "vaccine points" may be prepared. If properly preserved in sealed tubes in a dark, cool place the virus should remain active for at least three months. According to Park and Huddleson, 10 grams of pulp and 200 charged slips would be an average yield from a calf, and when made up should suffice to vaccinate at least 1500 persons. Calves vary greatly in their yield of virus. Of two calves vaccinated in exactly the same manner, one may furnish material for 500 vaccinations and the other for 10,000 inoculations. Testing the Vaccine. — The virus may be tested for its efficacy by a variety of methods. Calmette and Guerin 1 inoculate rabbits upon the inner surfaces of the ears and estimate the potency of the virus from the speed of development and the size of the resulting lesions. Guerin2 estimates the potency of virus quantitatively by inoculating rabbits with serial dilutions ranging from 1 : 10 to 1 : 100. Fully potent virus should cause closely approximated vesicles in a dilution of 1 : 500, and numerous isolated vesicles in a dilution as high as 1 : 1000. Quantitative estimation of the bacteria in the glycerinated virus is made by the plating method, and the vaccine used only when the numbers of bacteria have been greatly diminished or are entirely absent. The vaccine is also tested for tetanus by injecting relatively large quantities subcutaneously into guinea-pigs and mice. Under the Federal Law of July 1, 1902, and the regulations framed thereunder, all firms manufacturing vaccine virus are required by the Secretary of the Treasury to obtain a license before they may sell their products in interstate commerce. The vaccine laboratories are carefully inspected by an official of the Hygienic Laboratory of the United States Public Health and Marine-Hospital Service; the inspector carries away with him as many samples of virus as he wishes, and additional samples are purchased in the open market in different parts of the country. All these are subjected to a vigorous bacteriologic examination, especially for tetanus bacilli, by a laboratory worker who devotes all his time to this work. The federal regulations require each vaccine institute to perform a careful autopsy on each calf after the vaccine virus has been removed, and if any communicable disease is found or suspected in the animal, the virus must not be placed on the market, but must be destroyed. In accordance with this law, permanent records of the bacteriologic examinations of the virus and of the autopsy shall be kept in each institute. Noguchi's Method of Preparing Cowpox Virus. — Noguchi3 has succeeded in freeing vaccine virus from all associated bacteria by means of 1 Ann. de 1'Inst. Pasteur, 1902. 2 Ann. de 1'Inst. Pasteur, 1905. suitable disinfecting agents, and propagated the pure virus in the testicles of rabbits and bulls. The virus cultivated in this manner is not only devoid of bacteria, but appears capable of definite transfer from one animal to another. The multiplication of the virus within the testicle was found by Noguchi to reach a maximum on the fourth or fifth day after inoculation, with diminution after the eighth day. Skin lesions produced in rabbits and calves with the original and purified or bacteria-free viruses were found identical, and persons have reacted to the latter in an entirely typical manner. These results are of great value and importance and tend to increase the safety of vaccination and incidently weaken the arguments and contentions of antivaccinationists. Technic of Vaccination. — The essential part of the process of vaccination is that the virus should be introduced through the epidermis so as to be absorbed by the lymphatics and blood-vessels of the corium. The site usually chosen is the skin of the outer side of the upper arm, over the insertion of the tendon of the deltoid muscle. Sometimes, in females, the outer side of the thigh or well above the knee on the inner aspect of the thigh is used. Vaccination on the leg, however, is never advisable, as it would appear that such vaccinations are more prone to take on an excessive inflammatory action owing to the greater congestion due to the dependent position of the lower extremities; there is also more likelihood of secondary infection and mechanical violence occurring. • The skin is washed with alcohol and finally with water and then dried, care being exercised not to rub too vigorously; if the skin is reddened, it is best to wait until the hyperemia subsides. Grasp the arm with the left hand, rendering the skin tense, and with a sterile needle or scalpel carefully remove the epidermis over a square area measuring about one-eighth of an inch (Fig. 132). Bleeding should be avoided — an abraded surface that just oozes serum is especially to be desired. The virus is then expressed or placed upon this area (never blown out), and thoroughly rubbed in with a sterilized wooden tooth-pick or the vaccine point. After allowing the lymph to dry, a light sterile gauze dressing should be applied. Cross-scarification, which is forbidden in Germany, favors the growth of anaerobic bacteria under the crust that forms on the surface of the abrasion where the resistance is lowered by the action of the virus. The circular scarification gives more control over the dosage, and there is no tendency to the development of excessively sore areas. the epidermis with a sterilized needle. Usually one inoculation of the virus is sufficient, bub in times of threatened epidemic two or more inoculations are made at the same time, not only to insure a successful result, but rapidly to immunize the patient. It would appear that the degree of immunity bears some relation to the number or size of the vaccination lesions, and this can readily be understood if the infection is local and the body-cells are stimulated by a diffusible toxin. If, however, the vaccination lesion is but the pointfof entry of what becomes a general infection, then a small lesion CINATION SCAR. Fig. 133 shows a seven-day vaccination vesicle. Fig. 134 shows a nine-day vaccination vesicle just before pustulation occurred. Fig. 135 shows a recent vaccination scar with pitting and radiation; also a three-day "vaccinoid" or "immunity reaction" with a small vesicle. should suffice. This point has not been definitely settled, but statistics tend to show that persons vaccinated in two or more areas develop an immunity more quickly and that this immunity is more lasting. The subsequent care of the wound is of considerable importance. The operation is usually regarded as a trivial one, and justly so, but the lesion requires judicious after-treatment instead of being entirely neglected, as it so often is. The severe infections are usually attributable to gross and careless contamination of the wound. The best possible protection to the vaccinial ulceration is afforded by the formation of a hard, solid crust, due to desiccation of the contents of the vaccine vesicle and pustule. Unless undue inflammation and suppuration set in, such a crust will form. Care must be taken that the crust is not subjected to mechanical violence calculated to loosen or to detach it. Force and Stevens1 have recently advocated the routine use of three inoculations through small abrasions made with a chisel 2 mm. in diameter. This method is regarded as resulting in greater immunity and less likely to develop secondary infection. Constricting shields are likely to be unsatisfactory. The adhesion of the crust to the sleeve or to a piece of protective gauze will often lead to forcible decrustation when the sleeve or the gauze is removed. Schamberg and Kolmer 2 have found that daily applications of a 4 per cent, alcoholic solution of picric acid upon the vaccinated area after the first forty-eight hours does not interfere with the success of the vaccination, and lessens the degree of local inflammatory reaction and constitutional disturbances by hardening the epithelial covering of the vaccine lesion, and thereby decreasing the liability of extraneous bacterial infection. A point to be emphasized is that severe lesions are unnecessary, and are usually due to scratching of the vesicle or pustule and consequent introduction of dirt. No doubt tetanus bacilli may be introduced in this manner, the resulting scab affording the necessary anaerobic conditions for their development. The Phenomena of Vaccination; Vaccinia. — Immediately following vaccination a slight redness appears, which usually subsides rapidly. After a short period of incubation — on or about the third day — a slight red elevation makes its appearance, and the lesion begins to burn and itch. On the sixth or seventh day the abrasion becomes a small, silvery gray, umbilicated vesicle with a sharply raised edge, filled with a clear serum, and surrounded by a narrow red arepla (Fig. 133). By the tenth day the characteristic features are more marked, and the lesion has usually reached its height, being accompanied by a burning sensation and an almost uncontrollable desire to scratch (Fig. 134). The areola is now quite angry in appearance, and numerous minute vesicles are seen on its surface. By the twelfth day the areola is smaller, the contents become turbid and commence to dry, so that a few days later a scab has formed that drops off in another week or two. About the fifth day the child becomes restless and irritable and shows a slight elevation of temperature. These symptoms may become more pronounced until the end of the second week, when they subside rapidly. Precautions should be taken to prevent scratching and infection of the vesicle. The old-time " beautiful arms," with well-marked cellulitis and adenitis of neighboring glands, were largely due to secondary infection, and are not at all necessary in the process of vaccination. Evidence would tend to indicate that the vesicle is the typical lesion of both smallpox and vaccinia, and that the pustules are simply infected vesicles. Ordinary surgical care will do much to rob vaccination of its discomfort and to render the operation a most harmless one. The results of a vaccination, therefore, can be inspected and verified on or about the seventh to the ninth day. With persons who have been vaccinated successfully on a previous occasion the vaccinated area may show a slight areola at the end of twenty-four hours, with or without a papule, which subsides in seventy-two hours. This is called a "reaction of immunity," and is due to the presence of antibodies against the virus. Or a small, itchy, burning papule may form, which develops into a small vesicle maturing on the fifth or sixth day, and then rapidly subsiding, constituting the reaction known as vaccinoid (Fig. 135). Occasionally vaccination is followed by the appearance of various eruptions. The appearance of the scar varies according to its age and to the degree of tissue destruction. The physician is not infrequently requested to examine a person and determine if the scar is satisfactory evidence of successful vaccination. The typical good scar is circular, and about the size of a ten-cent piece, with smooth, white, and depressed center and a raised border. The border shows numerous radiations, and the entire scar may show little pits of former hair-follicles when the lesion was sufficiently destructive to remove the upper portion of the corium. (See Fig. 135.) A burn or an ordinary pyogenic infection may leave scars quite similar to those of vaccination, and vaccination scars may show wide variation, but the circumscribed character, the raised border with radiations and depressions, and the appearance of having been stamped on the skin by a sharply cut die are quite characteristic. Poor scars are those that were said to have been the result of vaccination, but in very many instances they are so indistinct as to make it difficult or impossible to recognize them as vaccination-marks. Revaccination. — One successful vaccination does not necessarily confer an absolute immunity against smallpox, and failure to recognize certain limitations in this respect has done harm by enabling antivaccinationists to create a distrust in the minds of the ignorant by pointing to individual instances of failure. That a person who has once been vaccinated may afterward suffer from smallpox is undoubted, but usually the vaccination was performed many years previously, and in any case the disease, when it does occur, is relatively mild (varioloid). There can be no doubt but that the immunity gradually diminishes. Perhaps seven years may be taken as the average period of fairly complete protection. Children should be vaccinated within the first year after birth, revaccinated upon entering school, and again after leaving it. If smallpox is prevalent, all persons should be vaccinated, regardless of the fact that they have previously been vaccinated. Only those who have had smallpox may be excused. If, as a matter of fact, persons are still immune, the vaccination will not "take" and no harm is done, whereas if it succeeds, such persons will have the satisfaction of knowing that their immunity has been increased. Hence it cannot be too strongly emphasized that not only vaccination, but revaccination, is indicated to protect the individual and society against smallpox. Dwyer claims that a person should be revaccinated repeatedly in succession until he fails to react; even a slight "take" would indicate incomplete immunity. Occasionally a non-immunized person refuses to "take," but vaccination should be repeated three or four times, as failure is not infrequently due to old and inactive virus, and the actual number of persons absolutely insusceptible is very small indeed. negligible. 1 . Tetanus. — The most serious of the inj uries that have been attributed to vaccination is tetanus. The tetanus bacillus and its spores are so wide-spread in nature that opportunity presents itself for contamination of the vaccinal wound and the virus itself. Every precaution should, therefore, be taken in the preparation of virus, and it is especially important that physicians and laymen should realize the necessity for ment of the vaccinal wound. It is exceedingly difficult to determine the source of infection in each case of vaccinal tetanus, but experimental investigations would tend to indicate that the virus itself is seldom, if ever, the vehicle of infection. John F. Anderson, Director of the Hygienic Laboratory, in testimony given before the Pennsylvania State Vaccination Commission, stated that in experiments carried out on monkeys and guinea-pigs with vaccine lymph purposely contaminated in the laboratory with countless numbers of tetanus spores, it was found impossible to communicate tetanus in this manner, although the vaccinations were more severe than the ordinary vaccinations performed on man, in that several places were inoculated and the areas abraded were large. Anderson stated that his " conclusion from these experiments is that it is almost impossible to produce tetanus, even with vaccine virus that contains tetanus germs in it, by the simple act of vaccination." Since 1909 there were approximately 100,000 specimens of vaccine virus examined in the Hygienic Laboratory, particularly with the purpose of determining the presence of tetanus germs or their products. The vaccine was purchased in the open market, and the examinations were made as thoroughly as it was possible to make them. To use Anderson's words: " We have never succeeded in finding any evidence of the presence of the tetanus organism or its products in vaccine virus." (Report of the Commission.) It would appear, therefore, that virus prepared according to modern methods and with all recognized precautions is safe. In view of the incidence of tetanus following other injuries, it is reasonable to conclude that most cases of vaccinal tetanus are secondary wound infections, and therefore largely preventable. 2. Syphilis. — With the use, years ago, of humanized virus, and particularly in the days of arm-to-arm vaccination, extremely rare instances of the transmission of syphilis have been known to occur. Since, however, the use of calf virus, which is the virus exclusively employed in this country, such an accident is absolutely impossible, as calves are not susceptible to luetic disease. 3. Cancer, foot and mouth disease, tuberculosis, and various chronic skin eruptions have been attributed to vaccination by its opponents; none of these claims has, however, been substantiated. minds of . right-thinking and unbiased persons. The history of the world before the days of universal vaccination shows the wide prevalence of smallpox and its fearful mortality. It was regarded as a disease of childhood, owing to the fact that all contracted it at the earliest opportunity, and, accordingly, smallpox was the cause of a fearful infant mortality. At the present day, owing to the general employment of vaccination, smallpox is a rare disease, but its very rarity has fostered a certain degree of false security and carelessness in carrying out the process. A young and new generation of non-vaccinated persons in any community is a source of danger, and accordingly sporadic cases are often blessings hi disguise, from the fact that, when they appear, compulsory vaccination is then instituted and large numbers seek revaccination. In Germany, where vaccination is compulsory, smallpox is now a comparatively rare disease. While the general death-rate from all diseases is lower in England and Wales than in Germany, the smallpox mortality is seven and one-half times the mortality of Germany, and, proportionate to the population, over 13 times. Austria, one of Germany's neighbors, had, for the twenty years following 1874, almost 30 times as high a smallpox mortality as Germany. During this period 239,800 persons perished in Austria from smallpox alone. Physicians should carefully impress upon those over whom they have any influence the necessity of being vaccinated, for only a thoroughly vaccinated population can solve the problem of exterminating smallpox as an epidemic disease. RABIES There are but few diseases more dreaded by the laity than rabies, or hydrophobia. Tales of the sufferings of infected persons, especially those with the furious variety of this infection, characterized by maniacal symptoms and dread of water (hydrophobia), have been thoroughly disseminated, so that the cry of "mad dog!" on the public streets is sufficient to arouse a general state of hysteric excitement in which an otherwise harmless creature may be compelled to bite or snap for selfprotection. Not all dogs under these conditions are mad or infected with rabies, and the bite of an angry dog, otherwise normal, is not necessarily dangerous from the standpoint of rabic infection. However, almost every one, upon being bitten by a dog, will promptly consult his physician, and this is proper and to be encouraged. Genuine rabies is an acute infectious disease in which the diagnosis is quite readily made, and whenever possible an effort should be made either to confirm or to disprove the diagnosis by making an examination of the animal's brain, and if the dog is found to have been free from rabies, this fact should be carefully impressed upon the patient, as otherwise the dread of infection may weigh heavily upon the patient and lead to distressing nervous disturbances. While the infectiousness of rabies has been known for a great many years and was proved experimentally by Galateir1 and Pasteur,2 it was not until Negri, in 1903, described certain bodies (Negri bodies), seen by him in large nerve-cells in sections of the central nervous system, that anything was found that seemed absolutely specific for rabies. Negri regarded these bodies as specific for rabies and probably of a protozoan nature. Later investigations fully established the diagnostic value of these bodies, and their definite characteristic morphology, evidences of cyclic development, and staining qualities indicate a protozoan structure resembling members of the Rhizopoda, designated by Anna Williams in 19063 as Neurorrhyctes hydrophobia. Rembringer,4 Poor and Steinhardt,5 Bertarelli and Volpino6 have demonstrated the filterability of the rabic virus, and Noguchi7 has cultivated from both " street" and "fixed" virus, very minute granular and somewhat coarser pleomorphic chromatoid bodies which, on subsequent transplantation, reappeared in the new cultures through many generations and reproduced typical symptoms of rabies in dogs, rabbits, and guinea-pigs. To Pasteur is due the credit for having discovered (1880) the fact that the disease may be prevented by conferring gradual immunization with increasing doses of the attenuated virus. This treatment, with some modification, is now used with evident success in all parts of the world. Nature of Rabies. — The virus or parasite is contained in the saliva of the rabid animal, and infection is possible when the skin is abraded by bites and scratches. The virus travels by way of the nerve-paths to the central nervous tissue, and, as in tetanus, the symptoms of the disease are due to involvement of these tissues. The period of incubation, or the time elapsing between the time of injury and the first symptoms, is quite variable, ranging from twenty to sixty days, although it may be as short as ten days. As in tetanus, this period depends upon — (a) the location of the injury; (6) the quantity or dose of virus ; (c) the kind of animal responsible for the injury. Bites about the face and fingers, especially if they are deep and lacerating, are especially dangerous; bites about the back and lower limbs, especially if superficial, are much less dangerous, and accompanied by a longer period of incubation. It is to be remembered that bites may be infectious as early as nine days before the dog shows well-marked symptoms of the disease. Not infrequently an animal is observed to be surly and snappy for several days before rabid symptoms develop, and a bite during this time should be regarded as dangerous. Only about 16 per cent, of human beings bitten by rabid animals and untreated appear to contract rabies. Since the establishment of the Pasteur treatment of the disease, the percentage of developed cases after bites is much lower — about 0.46 per cent. Diagnosis and Management of Rabies. — Even though an animal is unmistakably rabic, every effort should be made to destroy the animal, not only in order to prevent further damage, but to corroborate the diagnosis by microscopic examination of the nervous tissues for Negri bodies. 1. As a general rule, all animal bites. should receive surgical attention. Wounds produced by animals clinically rabid should be cauterized at once with fuming nitric acid or pure phenol. This is done to offset the delay in securing the Pasteur treatment, and because there is evidence to show that thorough cauterization of the wound is in itself highly beneficial. 2. The animal should be promptly destroyed, not only to prevent further damage, but in order to make a microscopic diagnosis by examination of the brain for Negri bodies. This examination is highly important and should never be omitted, for if it shows the absence of bodies, this fact should be carefully impressed upon the patient, as there is no doubt that a neurotic element, amounting in many instances to actual hysteria, may cause considerable harm to the patient even though he is definitely free from rabic infection. 3. The whole dog may be packed in ice and shipped at once to a central laboratory, or the head alone may be removed and packed in ice or glycerin and promptly shipped. The brain should not be disturbed. When it reaches the laboratory, the diagnosis should be made at once by " smear" preparations and sections of the brain demonstrat- ing the characteristic Negri bodies in the large ganglion-cells, and confirmed by inoculating emulsions of the brain into guinea-pigs or rabbits. The latter requires from ten to twenty days before the result may be known. A negative animal inoculation test is better evidence than a negative smear or section; obviously, these examinations are to be made only by properly trained persons. 4. Suspicious bodies in fresh brains, probably rabies. 4. If the animal was clinically rabid, the Pasteur treatment should be commenced as soon as possible, without waiting for the laboratory report, if this will be delayed for several days. Wounds about the face and hands, where there is no clothing to retain the infectious saliva, should receive intensive treatment; otherwise the milder course of immunization will suffice. 5. As a general rule, it is well to send the patient to a regular Pasteur institute, where there are special facilities for the proper treatment of these cases. Otherwise the physician may treat the patient at home. Several large manufacturing firms are prepared to ship by mail the fresh daily treatments properly preserved and ready for administration. 6. The Pasteur treatment should be given to every patient bitten by a rabid animal or by one suspected of being rabid. Not all persons are necessarily infected, even by bites of rabid animals, but this should not unduly influence the physician, for he will not have fulfilled his duty unless he carefully explains the etiology of the disease and advises immediate immunization. Aside from the actual benefits of the treatment, the mental effect upon the patient is deserving of consideration. Even slight wounds by rabid animals, wherever their location, should be regarded as dangerous, and the Pasteur treatment advised in addition to routine cauterization. 7. With severe bites of angry but not necessarily clinically rabid dogs, the treatment depends upon various factors. In any case the wound should be thoroughly cauterized and the animal carefully guarded (not killed) for two or three weeks. If rabid symptoms appear, the animal should be destroyed, the cerebral tissues examined, and the Pasteur treatment of the patient begun. In England, where strict laws are enforced relative to the muzzling and control of dogs, rabies is relatively infrequent, and it is especially urged that similar measures be adopted and enforced in our own communities, particularly during the summer months. Principle of the Pasteur Treatment (Active Immunization) of Rabies. — This method is based upon the principle of stimulating the production of rabic antibodies by injecting attenuated or modified virus during the period of incubation, so that the virus introduced into the wound is destroyed, neutralized, or its effects neutralized, while the virus itself is finally destroyed. Pasteur worked out this theory and established its truth by experiments upon the lower animals before applying the treatment to man. By passing the virus through a series of rabbits, the period of incubation is shortened to about six to seven days, and at the same time its pathogenicity for man is actually diminished (virus fixe). By drying the tissues containing the fixed virus attenuation is secured, so that it is easily possible so to modify the virus that it cannot produce rabies in man, but yet is able to produce the specific antibodies. The Pasteur treatment is, therefore, a process of active immunization with emulsions of a tissue (spinal cords of infected rabbits) in which the virus has been attenuated by a process of drying and desiccation. The early doses consist of highly attenuated cords, and succeeding doses become gradually more potent, as is usual in the technic of any method of active immunization. Preparation of the Rabies Vaccine. — As a preliminary, it is necessary to prepare or obtain "virus fixe.'' This may generally be procured from a laboratory, or may be prepared by passing street virus from the medulla of a rabic cow or dog through a series of young rabbits. After from 30 to 50 passages the incubation period is gradually reduced to six or eight days (" virus fixe") . 1. From an animal succumbing the day or night before, a piece of the floor of the fourth ventricle measuring about 2 cm. in length is emulsified in 1 c.c. of sterile bouillon, and three or four drops of this emulsion are injected beneath the dura of a normal rabbit. In large institutes two or more rabbits are injected daily. The inoculation is quickly and easily performed by trephining a small area in the median line of the forehead and injecting the emulsion beneath the dura mater and practically painless manner. 2. After inoculation the animals are placed in clean cages; in from six to eight days paralytic symptoms of rabies appear, followed in three to four days by death. The hair is then sprayed with a solution of lysol and the skin removed. The cord and brain are then extracted under aseptic precautions. The cord is severed just below the medulla, a portion is snipped off into sterile bouillon for culture, and then divided into two equal pieces which are suspended by sterilized silk threads in a sterile glass jar containing flakes of caustic potash (Fig. 136). The medulla is placed in a sterile dish, and is used to continue the inoculations, as was previously described. A postmortem examination is finally performed, and any cord in which the animal is found diseased or in which the culture of the cord shows bacterial contamination is rejected. The jars with suspended cords are kept in a special room at a temperature of about 20° to 25° C. 3. After a suitable period of drying pieces of cord are prepared for injection. This is performed in various ways at different laboratories; no attempt at exact dosage is made. In the New York Board of Health laboratories 1 cm. of the cord is thoroughly emulsified in 3 c.c. of sterile saline solution, the process being conducted in an aseptic manner. If the material is to be shipped, an addition of 20 per cent, of glycerin and 0.5 per cent, of phenol is made. Administration of the Vaccine. — Injections are given with a sterile syringe. The abdominal region of the patient is bared, a spot touched with tincture of iodin, wiped with alcohol, and the injection given subcutaneously. Keirle does not vary the dose according to the age, both the old and the young receiving the same dose. At times the injection is followed by redness and induration in the subcutaneous tissues, but abscesses are never formed. treatment may be mild (mild treatment). The uniform dose of cord emulsion, prepared as just described, is 2.5 c.c. The series of inoculations given in the Research Laboratory of New York in treating human cases after an average bite are as follows: 2 day cord Results. — According to reliable statistics, the mortality of rabies without the Pasteur treatment is about 16 per cent.; with the treatment the average mortality is about 0.46 per cent. The mortality of those bitten about the face or head is about 1.25 per cent.; of those bitten on the hand, 0.75 per cent. ; of those bitten on other parts of the body, a little over 0.25 to 1 per cent. In the Pasteur Institute of Paris only such persons are treated as have been lacerated, so that the virus has gained entry into the wounds. Viala1 reports that during the year 1915 as many as 654 persons were treated, with a single death. Taking into consideration only those cases in which the diagnosis of rabies has been confirmed in the animal by a competent examiner, the mortality of the cases treated at the Pasteur Institute in Paris for the past ten years, and covering the treatment of nearly 6000 persons, is only 0.6 per cent., which, compared to the average mortality of 16 per cent, without vaccine treatment, speaks most favorably for the value of Pasteur's antirabic immunization. 40 to 60 per cent, without treatment. When symptoms of rabies have appeared, the treatment is unavailing. Antirabic serums have been prepared by immunizing animals, such as sheep and horses, and these should be tried in human patients presenting symptoms, but the results in general have not been uniformly encouraging. TYPHOID FEVER Our knowledge of vaccination in typhoid fever begins with the work of Pfeiffer and Kolle.1 These observers, in 1896, immunized two volunteers with heat-killed cultures, and by complete laboratory investigations demonstrated the identity of the immunity following an attack of the disease with the artificial immunity produced by inoculation. At about the same time Wright,2 of London, inoculated two men with killed cultures, and a year later published the results of the successful vaccination of 17 persons. In 1898 be continued the work in India, where 4000 soldiers were inoculated, with encouraging results. Later, during the Boer war, Wright and Leishman treated 100,000 men, and the results, while good, were not encouraging, due, as pointed out later by Leishman,3 to the fact that the vaccine was damaged during its preparation by overheating. Since 1904 an improved vaccine has been used among the British troops in India in ever-increasing quantities, with uniformly good results. Antityphoid vaccination was begun in the United States army in 1908, the vaccine being prepared by Major Frederick F. Russel. Its value has been established so clearly that vaccination is now compulsory. The results obtained in the army have had considerable influence in establishing a wide-spread general confidence in antityphoid inoculation. Preparation of Typhoid Vaccine. — Based upon general principles, the vaccine should be prepared of typhoid bacilli as little changed by heat or chemicals as possible. Russel has prepared the army vaccine with a single avirulent culture which proved by animal experiments and laboratory methods capable of producing large quantities of immune agglutinins and bacteriolysins. As a general rule, however, the vaccine should be polyvalent, and particularly in view of the experiments of Hooker,4 who has shown by complement-fixation tests consistent antigenie differences among some strains of Bacillus typhosus. The preparation of the vaccine is comparatively simple. The bacilli are grown on agar for twenty-four hours, washed off with sterile normal salt solution, standardized by counting the bacilli, and killed by heating to 56° C. for one hour. As a matter of safety, 0.25 per cent, of tricresol is then added (Russel). The details of the technic are given in Chapter XIII. Metchnikoff has never fully accepted the belief in the value of heatkilled vaccines, and at present is actively concerned with vaccines prepared of living bacilli sensitized with their immune serum (sensitized vaccines). Injection of these vaccines into chimpanzees is not followed by any untoward effects, and apparently the bacilli so administered are destroyed at once, as they have not been found in the blood, urine, and feces. Metchnikoff and Besredka have immunized persons according to these methods and report excellent results. Obviously, there is some reluctance in using a vaccine of living bacilli until extended animal experiments have proved that they are harmless and more efficient than the vaccines of killed bacilli. the second and third doses. Method of Inoculation. — The vaccine is best administered at about 4 o'clock in the afternoon, so that the reaction appears during the night and is least likely to be disturbing. It is well to administer a cathartic the day before the inoculation is made. Inoculations should not be given during the menstrual period, as the general reaction is likely to be somewhat severer at this time. The skin over the insertion of the deltoid muscle is touched with tincture of iodin and the injection given subcutaneously. Intramuscular injections should be avoided, as the reactions are more unpleasant and accompanied by unnecessary pain on movement. In making deep injections there is also danger of striking a nerve, a proceeding that may be followed by disagreeable neuritis. The syringe and needle should be sterile. Commercial firms have placed the prophylactic on the market in syringes with sterilized needles, accompanied with full instructions as to the technic of administration. The vaccine should be well shaken before the injection is given. Third dose: 1,000,000,000 bacilli. These amounts are contained in 1 c.c. (about 15 minims). Children receive doses in proportion to their weight; if the dose cannot be divided evenly, it is better to give a little more rather than a little less, for children tolerate the injections remarkably well. The local reaction consists of a small red and tender area lasting about forty-eight hours. Occasionally the edema and pain may be more marked, but abscess formation is practically unknown. The general reaction, when present, gives rise to headache, malaise, and sometimes to fever, chills, and occasionally to nausea, vomiting, or diarrhea. The severe reactions are not alarming and disappear quickly. The inoculated person should abstain from severe exercise for the following twenty-four hours and rest; in the great majority of instances our soldiers have not been inconvenienced and were able to continue with their routine duties. A comparison of these tables shows that the general reaction is much more infrequent or milder in children than in adults, even after the first dose; after the second and third doses the difference is more marked. In former years considerable stress was laid upon the possibility of a negative phase following the inoculation, during which a person was believed to be more susceptible to infection. This is now believed by Leishman, Russel, and others of extended experience to be incorrect, the more general belief being that inoculations may be made and are especially indicated during epidemics of the disease. Duration and Degree of Typhoid Immunity. — It should be emphasized that immunity following typhoid immunization is not absolute,, and an immunized person cannot afford to neglect ordinary precautionsagainst infection. A lowered state of general body health or a large dose of infectious material may at any time result in infection. The immunity is apparently manifest soon after the first and second doses have been given. The duration is nob known definitely. From the rich experience of the British army in India Colonel Firth 1 concludes that immunity begins to decline in about two and one-half years after inoculation. However, even after four and five years the typhoid rate among the inoculated is, estimated roughly, one-fourth that of unprotected troops. Sensitized Typhoid Vaccine of Gay and Claypool. — Gay and Claypool,2 who have made an extended and extensive study of typhoid immunization, have advocated a polyvalent, sensitized typhoid vaccine sediment for prophylactic immunization against typhoid fever, as being superior to other forms of typhoid vaccine. Force3 has found that this vaccine produces less reaction and Sawyer4 has found it more protective than several other types of commercial vaccine. Gay's vaccine consists, of the ground sediment of a mixed polyvalent vaccine that has been sensitized by an antityphoid serum and then killed and precipitated by alcohol. From this ground culture the endotoxins are extracted by carbolated saline solution and the remaining sediment of bacterial bodies alone used for prophylaxis and in the treatment of typhoid fever. to an original bacteria count of about 750,000,000, is administered by subcutaneous injection every other day until three or four doses have been given. This vaccine is claimed to produce a better and more prompt immunity response than other vaccines. It has also been used in the treatment of typhoid fever by intravenous injection. Results. — The value of the typhoid prophylactic therapy is best shown in the army, where conditions are better controlled than is possible in civilian life. In 1911, of a division of United States troops, about 20,000 men along the southern boundary, only two cases of typhoid fever developed and both recovered. During this same period of time 49 cases were reported in the city of San Antonio, with 19 deaths. The soldiers mixed freely in the city, ate of fruits and vegetables, drank of the same water, and in this manner were freely exposed, although the sanitary conditions in the camp were excellent. In 1898, during the Spanish War, there were assembled at Jacksonville, Florida, 10,759 troops, among whom there were certainly 1729 cases of typhoid, and including the suspected cases, this figure reached 2693 cases, with 248 deaths. This camp continued about as long as that in 1911, the climatic conditions and water supplies being practically the same, but the sanitary conditions were bad. The remarkable difference in the typhoid rate cannot, however, be reasonably explained by perfect camp sanitation, and the results in 1911 leave no doubt as to the value of antityphoid vaccination. Excellent results have been reported by Spooner, Hachtel and Stoner, and others as to the prophylactic value of typhoid immunization in hospital-training schools for nurses, insane asylums, and other public institutions. Recommendations. — In view of the satisfactory results obtained in the army, typhoid vaccination is now obligatory on all members of the army and navy corps. Protection of the individual by immunization is the only measure of protection independent of surroundings and effective under all conditions. Typhoid inoculation in civilian practice cannot be as wide-spread or as readily performed as vaccination against smallpox, as the prophylactic must be administered subcutaneously and more than one dose is necessary. 1. Our various State and city boards of health should endeavor to educate the laity, and, if necessary, offer the prophylactic free of charge in order to build up a vaccinated community as far as this is possible. as physicians, nurses, and attendants in hospitals, should be immunized. Hospital authorities are justified in making typhoid vaccination obligatory on all applicants for admission to training schools. 3. All inmates of asylums, homes, and other public institutions under forty-five years of age should be immunized and the State should be ready, if necessary, to furnish the vaccine. or mountain resort. 6. In times of epidemics of typhoid fever the physician should urge vaccination of all over whom he has influence. Thorough vaccination with proper sanitary conditions offers the best hope of eradicating this dreaded disease. According to recent experiences in the European armies prophylactic immunization with typhoid vaccine does not afford protection against infections with Badllis paratyphosus A and Badllis paratyphosus B. In this country various investigators have estimated that about 2 to 4 per cent, of the cases of so-called " clinical typhoid fever" are due to paratyphoid infections; apparently the majority of these are with Badllis paratyphosus B. It would appear advisable therefore to immunize with these microorganisms in addition to Bacillis typhosus, and particularly members of the Army, Navy, National Guards, and all volunteer organizations called into service in time of war. For over a year I have been using routinely a mixed vaccine prepared in the same manner as the typhoid vaccine, each cubic centimeter of which contains 500,000,000 typhoid bacilli of the army strain and 250,000,000 each of Bacillis paratyphosus A and B, the latter strains being selected from a number on the basis of stimulating the production of agglutinins to a well-marked degree in persons and rabbits. The first dose of this mixed vaccine is \ c.c. ; three more injections are made at intervals of a week of 1 c.c. each, making a total of four injections. In the Army a mixed vaccine of paratyphoid bacilli is generally administered after the usual course of three injections of typhoid vaccine, and in the same manner. Three doses are given; the first dose contains 500,000,000 Badllus paratyphosus A and 300,000,000 Badllus paratyphosus B; the second and third doses are the same, and contain 1,000,000,000 Badllus paraty* phosus A and 600,000,000 Badllus paratyphosus B. Preliminary studies upon prophylactic immunization of persons with Bacillus typhi exanthematici, a Gram-positive pleomorphic bacillus secured in blood-cultures from persons suffering with typhus fever by Plotz, Olitslsy and Baehr,1 seem to indicate that a vaccine of this bacillus is capable of reducing the incidence of the disease, although it does not produce an absolute immunity to typhus fever (Plotz, Olitsky, and Baehr).2 The vaccine is polyvalent and is sterilized by heating to 58° to 60° C. for from half an hour to one hour. The suspension is so diluted that each cubic centimeter contains about 2,000,000,000 bacteria, and is preserved with 0.5 per cent, phenol or tricresol. Three injections consisting of 0.5, 1, and 1 c.c., respectively, have been given in five- or sixday intervals. The subject is in the experimental stage. PNEUMONIA In the prophylaxis of lobar pneumonia by active immunization Wright3 has had an unusually rich experience in the Rand mining district of South Africa where a severe type of pneumococcus pneumonia has claimed a high morbidity and mortality among the natives. After a considerable amount of experimentation the administration of a single large dose of stock vaccine containing 1,000,000,000 cocci was generally employed. Wright thinks that this vaccine reduced the incidence of pneumonia among the natives during the first three months following inoculation. Later reports of this work have failed to establish the efficacy of active immunization in preventing the development of pneumonia or materially lowering the mortality. Since, however, recent investigations by Lister4 have shown the existence of different serologic types of pneumococci on the Rand, an improvement in the efficiency of Wright's vaccine may have been made by using a mixed vaccine of these special strains; if a vaccine is employed as a prophylactic measure in pneumonia, it should be prepared of a number of strains belonging to types I and II at least and several injections should be given at intervals of five or seven days. The protection is likely to be of short duration, but the method would appear worthy of trial under these conditions and particularly during the seasons when pneumonia ground squirrels, especially of the former, about the wharves of seaport cities arid towns is highly essential, as the disease is transmitted by the fleas of these rodents. Aside from sanitary measures, plague vaccine, especially that of Haffkine, has now been used extensively, with encouraging results. Preparation of Plague Vaccine. — The Haffkine prophylactic is prepared by growing pure cultures of Bacillus pestis in flasks of neutral bouillon to which a few drops of sterile olive oil or butter-fat have been added, to serve as floats from which the surface growth of the bacilli can take place. The flasks are cultivated at from 25° to 30° C. for five to six weeks, and are shaken every two or three days, by which the hanging, stalactite-like colonies are thrown down, so that a new crop of the bacilli can develop in contact with the air. After growing for six weeks the purity of the culture in each flask is tested by subcultures on agar and by direct smears. The masses of bacilli are broken up by shaking, and the material is sterilized by heating at 65° C. for from one to three hours. Phenol is added to the point of 0.5 per cent., and the fluid is tested for sterility by culture. If it is found sterile, it is finally poured into small vials of from 10 to 30 c.c. capacity. Kolle prepares a vaccine by cultivating the bacillus for two days in flasks of agar measuring 10 by 9.5 cm. Each surface of agar equals about 15 ordinary agar slant cultures, and an agar slant holds about 15 loopsful of culture (4 mm. loop). A loop of this size holds about 2 mg. of organisms, and, accordingly, a flask of agar contains about 225 loopsful of culture, or 225 doses of 2 mg. each. Kolle prepares the vaccine in amounts of 0.5 c.c. per dose (2 mg. of bacilli), and the growths in each flask are removed with 112.5 c.c. of sterile normal salt solution. The emulsion is shaken to break up clumps, heated for one hour at 70° C., and tested for sterility. It is then preserved with phenol or tricresol and placed in ampules containing 0.5 c.c. each. The German Plague Commission strongly recommended the use of twenty-four- to forty-eight-hour-old agar cultures instead of the old bouillon cultures employed in the preparation of Haffkine's vaccine. duced virulence for the immunization of man. Lustig and Galeotti prepare a vaccine of the toxic precipitate produced by dissolving the bacilli in a 1 per cent, solution of caustic soda and neutralizing with 1 per cent, of acetic acid. This precipitate is dried in vacuo and redissolved in a weak solution of sodium bicarbonate, the dose for adults being 0.0133 gm. of solid substance. Terni and Bandi inoculate rabbits or guinea-pigs intraperitoneally with the bacillus, and just preceding or directly after death they collect the peritoneal exudate, in which the organisms are allowed to continue growing for twelve hours more. The bacilli are then killed at a low temperature, and the fluid thus obtained, after a preservative has been added, constitutes the vaccine. Dosage. — The ordinary dose of Haffkine's prophylactic for adult males is from 3 to 3.5 c.c. ; for adult females, from 2 to 2.5 c.c. Haffkine himself has injected larger quantities without resulting harm. He recommends giving a second injection after from eight to ten days. The injections are given subcutaneously, with a sterile syringe, into the upper arm or elsewhere in areas where the skin is not tightly bound down. The local and constitutional effects are similar to those in typhoid except that they are slightly intensified. The inoculation is followed by redness and swelling at the seat of inoculation, and general symptoms in the form of rise of temperature and a feeling of illness. The latter pass off in twenty-four hours, but the patient should rest during the first day after inoculation. Duration of Immunity. — The immunity is apparent a few days after inoculation, but is of short duration. In India the protection is believed to last at least three months and possibly longer. In times of epidemic the inoculations should be repeated at least two or three times a year. The brief duration of the immunity is probably one reason why better results are not secured. Best results are observed during epidemics when protection is afforded for a short time, or until the danger is past. In countries or localities where the disease is endemic, persons may refuse repeated inoculation and thus become susceptible to infection. Strong and Teague.1 In the bubonic variety Haffkine's vaccine has in general yielded encouraging results. The protection is not absolute; the immunity is of relatively short duration, and therefore good results are not so readily appreciated when the disease is endemic. The mortality among the inoculated is much lower, i. e., 11 to 41 per cent., as compared with 50 to 92 per cent, among the non-immunized. Haffkine summarized his results a few years ago as follows: Among 186,797 inoculated persons there were 3999 attacks, or 1.8 per cent.; among 639,630 uninoculated persons there were 49,433 attacks, or 7.7 per cent., with 29,733, or 4.7 per cent, of deaths. CHOLERA Protective inoculation against cholera was first practised by Ferran, a Spaniard, in 1884, although little definite knowledge as to the value of the procedure resulted from his work. He is said to have used impure cultures of bacilli isolated from the feces of cholera patients. Broth cultures were prepared, and the living organisms injected subcutaneously, using eight drops for the first and 0.5 c.c. for the second and third doses, the injections being given at intervals of six or eight days. While his method and results have been questioned, he was, however, the first to use a method employed later, with some modifications, by Haffkine in India with good results. Preparation of Cholera Vaccine.— Haffkine, following Pasteur's method with anthrax, uses two vaccines, — a weaker and a stronger, — living microorganisms being used in both and injected subcutaneously. Vaccine No. 1 is weaker, and is obtained by growing the bacilli on agar at a temperature of 39° C. Vaccine No. 2 is composed of more virulent organisms, prepared by passing the vibrios through a series of guineapigs until a strain is obtained which is invariably fatal to these animals within twelve, or at least twenty-four, hours. Cultures are grown on agar, washed off with 8 c.c. of sterile bouillon or saline solution, and administered in doses of 1 c.c., which is equivalent to about two loopsful (4 mm.) or 4 mg. of living bacilli. Kolle has shown, however, both by animal experimentation and in the human being, that heat-killed cultures are equally good, and that living cultures are unnecessary and may be undesirable. paration of plague vaccine, and removing the growths with sufficient salt solution so that 1 c.c. shall contain one loopful (4 mm.) of organisms (2 mg.). The emulsion is then shaken to break up clumps, heated to 60° C. for from one-half to one hour, cultured to determine sterility, and preserved with 0.5 per cent, phenol. Strong has proposed the use of the products obtained by "autolytic digestion" of the organism, i. e.} by incubating an emulsion of them in sterile water, in which they break up spontaneously. Twenty-four-hour agar cultures are removed with sterile water, placed in a sterile flask, and kept at a temperature of 60° C. for twenty-four hours. The mixture is then put aside in the incubator for from two to five days. The best results are obtained apparently after five days' autolytic digestion. After such digestion the emulsion is filtered through a Reichel filter. The fluid thus obtained must, of course, be examined for sterility and carefully standardized before being used as a human vaccine. five days. The local effects are usually marked by more or less pain and edema, which subside in forty-eight hours. The constitutional effects are not infrequently severe, being marked by malaise, fever (100°— 101° F.), nausea and vomiting, followed the next day in about 10 per cent, of persons by transient diarrhea. Usually all symptoms have disappeared within seventy-two hours. Results. — Haffkine's prophylactic vaccine has yielded favorable results in India. Powell reports 198 cases of cholera among 6549 nonimmunized persons, with a total mortality of 124. Of 5778 inoculated persons, there were 27 cases, with 14 deaths. Much better results were obtained with Kolle's vaccine, and it is now generally used in preference to the Haffkine vaccines. Murata, during an epidemic in Japan in 1902, vaccinated 77,907 persons. Of these, 47, or 0.06 per cent., developed cholera, and 20, or 0.02 per cent., died. Of 825,287 uninoculated persons, 1152, or 0.13 per cent., died. During a recent epidemic in Russia Franschetti inoculated 11,178 persons. Of these, 8 contracted cholera and 1 died. In St. Petersburg, during 1907-08, 30,000 persons were inoculated. Of these, 12 developed cholera and 4 died. Of 10,000 uninoculated persons, 68 contracted the disease. some immunity. This protection may be apparent after the first dose, but is more marked after the second. The immunity conferred is far from being absolute, and it is noteworthy that while the prophylactic diminishes the liability of the inoculated person to cholera, it has less influence on the mortality when the disease occurs in those who have been vaccinated. . Dysentery. — Protective vaccination against bacillary dysentery has been attempted, but has not as yet yielded satisfactory results. Shiga practised mixed active and passive immunization (vaccine plus immune serum) on 10,000 persons, and while this did not decrease the number of infections, a lower mortality resulted. The various types of the dysentery bacillus and the high toxicity of the vaccines are obstacles to the more general use of protective inoculation in this condition. Cerebrospinal Meningitis. — Sophian and Black1 have shown experimentally that a polyvalent meningococcic vaccine, heated to 50° C., standardized in the usual manner, and given in three injections, in doses of 100,000,000, 500,000,000, and 1,000,000,000, at intervals of a week, appears to afford a high degree of protection. In the bloodserums of inoculated persons these observers were able to demonstrate opsonins, agglutinins, and complement-fixing amboceptors. All evidence points to the efficacy of prophylactic vaccination, as only a moderate degree of immunity may give complete protection against the disease. The method has not thus far received extensive trial, but in the presence of an epidemic its harmlessness and apparent value should be borne in mind. Scarlet Fever. — Several Russian physicians, particularly Gabrickevski,2 Longovi, Nitikin, Shamarin, and others, have secured good results from a method of prophylactic vaccination against scarlet fever with a polyvalent vaccine of scarlet-fever streptococci. Heat-killed vaccines were given in three successive doses. In this country the method has been tried by Kolmer,3 who found that while inoculations with a heat-killed streptococcic vaccine cannot prevent scarlet fever Pertussis. — Several observers have advocated prophylactic immunization against pertussis among children who are exposed or likely to be exposed by the subcutaneous administration of a stock pertussis vaccine in dose of about 100,000,000 bacilli at intervals of a week. PROTECTIVE IMMUNIZATION AMONG THE LOWER ANIMALS Since discoveries in bacteriology and immunity have usually been intimately associated with animal experimentation, it is not strange that the lower animals should have been the first to benefit from the knowledge thus gained. As a consequence, vaccine therapy, both prophylactic and therapeutic, is being extensively used in veterinary practice with good results. ANTHRAX This was one of the first vaccines studied by Pasteur, and as a prophylactic measure, it has proved of great value. It finds its greatest field of usefulness in case of an outbreak of anthrax, when it is used to protect the uninfected members of a herd, as well as any animals pasturing on infected areas. In preparing the vaccine Pasteur was hampered by the fact that the spores of anthrax bacilli retain the virulence of the original bacilli. As the result of extended experiments, however, he discovered a means of attenuating the virulence of cultures by growing the bacilli at a temperature of 42° C.; he also found that inoculation with these attenuated bacilli would effectively vaccinate sheep and cattle, and so protect them against an attack of the disease. One of the most dramatic stories1 in the history of science is the account of the method by which Pasteur demonstrated his discovery to the public. Certain harsh critics, having heard of Pasteur's ability to prevent anthrax in laboratory experiments, and anxious to humiliate him, sent him a public challenge to demonstrate the experiment on a practical scale at a farm in the country. A number of farmers offered to place 60 sheep at his disposal. The challenge was immediately accepted, and Pasteur mapped out a plan of action, in which he safeguarded himself by making no half-statements, but boldly promised complete success. Of the total number, 25 sheep were to be vaccinated and 25 were to remain unvaccinated. A fortnight later all 50 were to 1 Narrated by Elizabeth Fraser. receive a lethal dose of the fully virulent anthrax. He declared that the 25 non-vaccinated sheep would die, whereas the 25 vaccinated would remain alive and well. The remaining 10 sheep were to serve as controls. The challenge and its acceptance were widely advertised in the journals, and Pasteur was made the subject for many witticisms. Excitement ran high, and a large crowd, comprised of physicians, veterinary surgeons, journalists, farmers, etc., accompanied Pasteur to the farm (Pouilly le Fort) where he was to make the final test by inoculating the deadly anthrax. One vaccinated animal developed a temperature overnight, a fact that caused Pasteur much anxiety. On going to the farm the next day, however, again followed by the crowd, he found all the vaccinated animals well! Of the unvaccinated, 22 were dead, and the others died during the following night. Pasteur's triumph was complete, and the possibility of preventive vaccination was demonstrated to the world. bacilli. Vaccine No. 1 is weakest or lowest in virulence, and the first to be injected. This vaccine is prepared by growing virulent anthrax bacilli at a temperature of 42° C. for from six to ten weeks, or until tV loopful of the culture, when injected into rabbits, guinea-pigs, and mice, will show virulence for mice only, but not for guinea-pigs and rabbits. Vaccine No. 2 is prepared by growing virulent anthrax bacilli at 42° C. for about twenty days, or until tV loopful is virulent for mice, partly so for guinea-pigs, and not at all for rabbits. Vaccine No. 3 is not generally used except for immunizing sheep and goats. When, however, it is required, it is made as follows: Virulent anthrax bacilli are grown at 42° C. until yV loopful, when injected into mice, guinea-pigs, and rabbits, will be virulent for all the mice, all the guinea-pigs, and some of the rabbits. The vaccines are prepared in ampules containing 1 c.c. of the emulsion, each representing one dose, to be injected subcutaneously. Vaccine No. 2 is injected twelve days after Vaccine No. 1, and No. 3 after the same interval following Vaccine No. 2. The resulting immunity usually lasts about six months. In instances where it is desirable to immunize a herd before turning them out to pasture on infected areas it is well to inoculate the animals in the early spring, keeping them in the stable during the time required for at least two vaccinations, for the reason that, immediately after vaccination, the animals may become hypersusceptible to infection. influence. The vaccine is prepared by the Bureau of Animal Industry in the following manner: The muscle tissue from a fresh blackleg tumor is ground in a mortar, extracted or macerated with a little water, and the fluid squeezed through cheese-cloth. The expressed fluid is then evaporated at a temperature of 35° C. The dry brown scale is run through a grinding mill and heated for six or seven hours at a temperature of from 94° to 96° C. This process of heating attenuates the virulence of the bacilli present so that, when injected, they produce but a mild attack of the disease. The Department of Agriculture places the ground material in packages containing a certain number of doses. These packages are, upon request, mailed to veterinarians, who dilute the ground muscle with as many cubic centimeters of sterile water as there are doses in the package. One cubic centimeter of the suspension is injected subcutaneously in some convenient area, as, e. g., about the shoulders. VACCINE THERAPY Principles. — Although bacterial vaccines have been extensively employed in the treatment of various diseases, it is difficult to express an opinion as to their real value, and it is altogether impossible to make dogmatic statements as to the percentage of cases in which they will be helpful or effect a cure, or as to what result may be expected in an individual case. Following Wright's original announcements, this special therapy was enthusiastically received by the profession, and in a short space of time the method was employed experimentally in many and diverse infections. It may be stated that in many infections the vaccines may be beneficial, but they should be used only under proper conditions, as was indicated in the first portion of this chapter. It may be stated in general that: some infections the former must be used. 3. It is not advisable to continue the use of the same vaccine for more than several doses if no reaction and no improvement are noted. New cultures should be made to determine if the right organism is being used, or if reinfection with another organism has occurred. 5. It is highly important that the usual forms of treatment be employed in conjunction with the vaccine therapy. Thus abscesses should be incised; proper drainage of a discharging wound afforded; discharging ears cleansed, etc. 6. While the dose should not be too large, neither should it be too small, nor too far apart. There is a proper dose for each patient, and this may be determined by starting with a small dose and gradually increasing it until some reaction is secured. An efficient dose must necessarily produce some reaction, and increased doses are contraindicated so long as any sign of general or focal reaction is produced and so long as steady progress is maintained. INFECTED WOUNDS In the treatment of infected wounds and sinuses autogenous vaccines are frequently of considerable value in those infections due to staphylococci and streptococci. In chronic suppurations pseudodiphtheria bacilli and Bacillus pyocyaneus are commonly found, but these microorganisms are likely to be secondary invaders. While bacterial vaccines are being employed the usual surgical treatment should be given, and it is particularly important to afford adequate drainage and remove foreign bodies, as sutures and bits of necrotic bone. Great care must be exercised in preparing the cultures in order that the infecting bacteria may be secured for the vaccine. In wounds likely to be infected with staphylococci or streptococci, it would be good practice to administer one or two doses of a stock vaccine in an effort to protect against infection. As discussed on page 94, recent investigations have shown that various bacteria and particularly strains of streptococci may gain entrance to the blood and lymph circulations through foci of infection, particularly at the roots of teeth and in the tonsils. Various lesions and particularly arthritis and endocarditis have been attributed to this mode of infection. In treatment particular attention should be given to the detection and removal of these foci, and autogenous vaccines prepared of cultures from the infected tissues may be of aid. DISEASES OF THE SKIN Furunculosis ; Abscesses. — Furuncles are usually caused by some member of the group of staphylococci, and frequently the most rational and successful form of therapy is by means of bacterial vaccines. A stock vaccine of Staphylococcus aureus may prove satisfactory, and should be used while an autogenous vaccine is being prepared. For adults the initial dose may be 100,000,000 cocci, succeeding doses gradually increasing until 1,000,000,000 are given at one time. The injections may be given at intervals of from five to seven days. Following the first few doses a slight focal and some constitutional reaction should be secured. After all the lesions have disappeared, one or two full doses at intervals of several months will continue to fortify the patient against a recurrence. Carbuncles. — These are invariably caused by the Staphylococcus aureus, and exceptionally by a streptococcus. The urine should be examined for sugar, and even if the patient is diabetic, small doses of vaccine may be of value when used in conjunction with the customary treatment. Sycosis. — Sycosis vulgaris is usually caused by the Staphylococcus aureus and albus, and such patients are frequently very rebellious to the ordinary treatment. An autogenous vaccine is very helpful in some cases. Due care should be exercised in making cultures to secure pus from a well-developed lesion. Relatively large doses of vaccine are necessary, and treatment is usually prolonged, at least 12 injections being necessary before the conclusion is reached that the vaccines are of no service. As a rule, the condition will improve under vaccine therapy, but only in exceptional cases does a complete cure result. Acne. — Acne is frequently caused by two microorganisms — a Staphylococcus and the acne bacillus. In cases showing pustulation a Staphylococcus is invariably present, and exceptionally the bacillus may be found alone in comedones. Cultures should be made from several lesions, being careful to secure pus that has not been contaminated by the skin. Stock vaccines may .be used, although autogenous vaccines are likely to yield better results. In view of the frequency of intestinal disorders among persons suffering with acne, Strickler, Schamberg, and I1 have studied the possible influence of Bacillus coli communis and communior by means of complement-fixation tests, and found that the sera of a large percentage of persons suffering with acne yielded positive reactions. On the basis of these results I have been incorporating in the vaccine one or more strains of Bacillus coli isolated from the patient's feces; this modification has appeared to increase the efficacy of the vaccine. It is well to administer a mixed vaccine of the straphylococcus, acne bacillus, and colon bacillus, especially if the lesions are pustular. It is highly essential that other forms of treatment be instituted while vaccines are being tried, as the treatment is usually prolonged. Exceptionally, however, a brilliant result may be observed after a few injections. I generally prepare a mixed vaccine of 10,000,000 acne bacilli to each 200,000,000 cocci and 200,000,000 Bacillus coli per 1 c.c. of vaccine. The first few doses consist of 0.5 c.c., and later this amount may be increased to 1 c.c. per dose. Doses are given every five to seven days, or just when retrogression is observed to occur. It may be necessary to use large doses, and in any case the treatment is prolonged over many weeks and months. Most cases will show improvement, but few are absolutely cured by a single series of injections. Eczema. — The prolonged administration of an autogenous vaccine of staphylococci secured from the scales of serous exudate of eczema have occasionaly aided in the treatment of obstinate cases. Impetigo and Ecthyma. — The administration of a stock vaccine of Staphylococcus albus arid streptococci or, preferably, of the cocci isolated from the pustules of impetigo contagiosa and ecthyma may be of considerable value in the treatment of infections tending to pursue a chronic course. Likewise the administration of an autogenous vaccine in impetigo herpetiformis may be of aid in the treatment of this frequently fatal infection in puerperal women. Dermatitis Venenata. — The most common forms of dermatitis due to poisonous plants are those caused by poison ivy or oak (Rhus toxicodendron) , and of sumach or dogwood (Rhus venenata). Certain persons are susceptible to a poisonous principle of these plants and develop a dermatitis after being in contact with them. This form of dermatitis is characterized by urticarial lesions and is regarded as an anaphylactic phenomenon and analogous to hay-fever. Specific treatment with extracts of ivy, sumac, and other plants aims to desensitize the patient or produce a condition of anti-anaphylaxis. Strickler, working in my laboratory, has succeeded in the treatment of a number of cases of severe ivy-poisoning; the extract is injected subcutaneously and usually affords relief within twenty-four hours. As in hay-fever, the desensitization is of short duration and the injections must be given at short intervals. It is highly probable that a prolonged series of injections will effectively and permanently desensitize. Ringworm. — Strickler1 has succeeded in treating ringworm of the scalp with a polyvalent vaccine prepared of pure cultures of the ringworm fungus. Usually seven or more injections were necessary at intervals of five to seven days. It would appear that this form of therapy is of value as an adjuvant to local treatment of obstinate infections. Erysipelas. — This infection is usually caused by the streptococcus erysipelatis. In severe cases an autogenous vaccine of about 20,000,000 cocci per cubic centimeter may be administered every three or four days, and frequently aids in reducing the severity of the inflammation and overcoming mental unrest and physical discomfort. A vaccine may be of aid in the treatment of subacute and chronic types of this disease. Stock vaccines are of little or no value. Cystitis. — Acute or subacute cystitis following catheterization after labor or surgical operations or occurring in children is usually caused by a member of the group of colon bacilli. It is highly essential, in order to attain success with vaccine therapy, that urine be collected aseptically and the causative microorganism secured and used in the preparation of a vaccine, as stock vaccines are of little or no value. Exceptionally the infection may be due to another microorganism, either alone or in conjunction with Bacillus coli. Treatment with an autogenous vaccine may be of distinct aid in lessening the symptoms and in reducing the amount of pus. The initial adult dose of Bacillus coli vaccine should be about from 50,000,000 to 100,000,000 bacilli. In subacute cystitis of the male, due to stricture of the urethra or enlarged prostate, or in the female, due to perineal injuries, not much benefit follows its use until the underlying cause is corrected or removed. Pyelitis. — Pyelitis in children and adults is usually due to Bacillus coli, and treatment with an autogenous bacterial vaccine has frequently yielded good results. The urine used for culture must be obtained under 1 Jour. Cutan. Dis., March, 1915, 161. aseptic conditions and preferably with a catheter. Stock vaccines of Bacillus coli and vaccines prepared of Bacillus coli isolated from the urine collected under ordinary conditions, and therefore likely to be other than that strain causing the infection, are of little value. Children usually bear the vaccine very well; I usually administer 50,000,000 to 100,000,000 bacilli every five to seven days. Urethritis. — There is a considerable difference of opinion as regards the efficacy of vaccines in the treatment of acute and chronic urethritis of gonorrhea! origin. A polyvalent stock vaccine of gonococci of proved immunizing powers may be even more efficient than an autogenous one, especially if the latter must be prepared from a strain that has been repeatedly subcultured in order to obtain the vaccine in a pure state, or from one that has lost its virulence from long residence in the infected urethra. Owing, therefore, to the difficulty of isolating and cultivating gonococci, stock vaccines have been generally employed. In subacute urethritis the initial dose may be 25,000,000; if complications threaten, less than this, and if no local reaction has followed more than this, is given, the object being to secure a slight increase of the secretion, which should become more purulent, and a little constitutional disturbance, followed by lessening of local pain and tenderness. In chronic urethritis the primary infection is gonococcal, although other organisms, such as the Micrococcus catarrhalis, staphylococci, and diphtheria bacilli may have some relation to the process. A stock gonococcal vaccine may be used in sufficient dosage to evoke a reaction; not infrequently, however, a stock and an autogenous vaccine or vaccines combined yield better results. Cultures of the urethra should be made only after thorough cleansing of the meatus and flushing of the urethra with sterile salt solution and massage of the prostate, cultures being made direct from the prostatic secretion or from the crypts through the urethroscope. In any case expert local treatment should be given while vaccines are being used. Gonorrheal Arthritis. — Polyvalent stock vaccines of gonococci have generally been found to be of distinct value in the treatment of this troublesome and oftentimes chronic infection. Local treatment of the urethra and general therapeutic measures should be employed. It may be stated that vaccines should be used routinely in all cases, as under any condition the infection is likely to be prolonged and tedious. In the acute stages the doses should be relatively small, about 10,000,000 cocci being given every three to five days. In the subacute stages from 50,000,000 to 100,000,000 may be given at intervals of from five to ten days. Vulvovaginitis of Children. — Stock goriococcal vaccines have been used quite extensively in the treatment of this troublesome infection. On the whole, good results have been reported, although in any case final judgment must be reserved until thorough bacteriologic examination shows whether the tissues are really free from infection or whether the infection has subsided and become chronic. Smears of the secretions alone are insufficient to determine whether a cure has been effected. Injecting a solution of 1 : 2000 bichlorid of mercury in normal saline solution into the vagina, followed by immediate centrif ugalization of the washings and smears of the sediment, will frequently demonstrate the presence of gonococci that will not otherwise be found. If vaccines are used, a dose of from 5,000,000 to 10,000,000 every five to seven days may be employed. RESPIRATORY DISEASES Rhinitis. — The use of mixed stock vaccines is being advocated for prophylactic immunization against recurrent attacks of acute rhinitis. Numerous reports by Coates, Fisher, and others have emphasized the value of this prophylactic immunization. With Weston, I have found autogenous vaccines of some value in lessening the severity and hastening the recovery from the acute rhinitis of scarlet fever, so potent a factor in the dissemination of that disease. In chronic rhinitis an autogenous vaccine, prepared by growing cultures with the care previously described, may be of distinct value, but only when an underlying factor, such as a malformation or adenoids, has been removed, and only when used in conjunction with efficient local treatment. In atrophic rhinitis good results have been reported by various observers with a vaccine of Bacillus ozena (Perez) ; in the experience of Ersner, working in my laboratory, the results have been usually disappointing. In view of the difficulty in curing this disease, a vaccine may be tried as an adjuvant to other measures. Hay-fever. — Hay-fever is now regarded as due to a state ol anaphylaxis or hypersensitiveness to the pollen of certain plants and grasses. Spring fever or "rose cold" may be due to the pollens of a wide variety of grasses and plants (red top timothy, rye, and orchard grass), while autumnal hay-fever is most frequently due to the pollens of rag-weed and golden-rod. Since the brilliant researches of Blackley,1 a large number of investigations have served to establish the nature of this troublesome disease on the basis of idiosyncrasy or local hypersensitiveness to the protein of one or more plants. According to Cooke and Vander 1 Virchow's Archives, 1877, Ixx, 429; Med. Times and Gaz., 1877, 2, 243. to spontaneous sensitization is inherited as a dominant character. Specific treatment with pollen extracts aims to desensitize the patient. With pure pollens at hand skin tests may show the particular one to which a patient is hypersensitive. A small abrasion is made and a minute amount of the powdered pollen applied; the development of an urticarial lesion within ten or fifteen minutes indicates that the person is hypersusceptible to that particular pollen. Ophthalmic tests have also been used for diagnosis and as a guide in treatment, but are not to be recommended. The satisfactory preparation of hay-fever vaccine has not as yet been accomplished, owing to the tendency of preparations to deteriorate and loose in antigenic or desensitizing properties. Hitchens and Brown2 prepare an extract of the pollen grains in physiologic salt solution, precipitate with acetone, and preserve the dried precipitate for the vaccine. For use, the precipitate is dissolved in physiologic saline solution sterilized by filtration and so diluted that the initial dose will contain 0.0025 mg. of protein. This vaccine maintained its therapeutic properties for two years. When the patient can be studied beforehand, a survey of his habitual surroundings should be made. After noting all the flowering plants which might reasonably come into question, skin tests should be made with pollens of each of these plants in order to determine which of them are responsible. In this connection it must be remembered that pollens may travel great distances (Blackley) , and a field of grain several miles away must be taken into account. A series of subcutaneous injections with the proper pollen preparations should now be administered; in my experience ten or more should be given with gradually increasing doses at intervals of five or seven days, and the course of treatment started in time to be finished a week or two before the expected attack. If the attack has already started, treatment should be begun at once with a vaccine representing the pollens most likely to be responsible for the attack. Not infrequently relief follows within twenty-four hours after an injection. The injection must be given as frequently as indicated to relieve the symptoms and make the patient fairly comfortable. ler,1 Manning,2 Cooke,3 Wood,4 Goodale,5 and Kitchens and Brown6 indicate that the vaccine treatment of hay-fever, and particularly the autumnal variety, is frequently successful and worthy of trial not only prophylactically but also during an attack. My own experience has been limited to 7 cases of the autumnal type due to rag-weed sensitization ; 4 of these persons were greatly benefited, 1 was not aided at all, and 2 have been apparently cured for a period of about two years. Bronchitis. — Allen speaks very highly of the value of autogenous vaccines in the treatment of acute and chronic bronchitis and bronchopneumonia of children. Various microorganisms are found in the secretions, and the vaccines used are generally mixed. The usual therapeutic measures are employed simultaneously. It is claimed that vaccines lessen the discomfort and hasten recovery. Recently I have observed very good results in the treatment of a number of cases of chronic bronchitis uncomplicated by bronchiectasis, and believe that an autogenous vaccine prepared under proper conditions forms a valuable adjuvant to treatment. Pertussis. — A hemophilic bacillus closely resembling the influenza bacillus has been ascribed by Bordet and Wollstein as the cause of pertussis. Several investigators who have used a stock vaccine of the pertussis bacillus claim that, used in small and appropriate doses, the severity of the paroxysms of coughing is lessened, and the whole course of the infection shortened; besides this, they assert, it decreases the danger of a complicating bronchopneumonia. When the disease is unusually severe and the prognosis is bad, a vaccine may be administered in doses of 25,000,000 if the patient is over four years of age. The pneumococcus and Bacillus influenzse are frequently associated, and a mixed vaccine of these microorganisms may be of special aid in the later stages of the disease. The usual remedial measures should be employed while vaccines are being tried. The reports of Bamberger7 and Graham8 indicate that the administration of a vaccine may be of value in lessening the severity of the disease. I have treated 6 cases with indefinite results; in 2 an .autogenous vaccine was employed and a stock vaccine in the remainder. A stock vaccine has been advocated for purposes of prophylactic immunization, especially in institutions, where pertussis among children claims a high mortality. Otitis Media. — Autogenous vaccines prepared from carefully made cultures of the diseased tissues, secured with the aid of an ear speculum, may prove of some value in the treatment of subacute and chronic suppurative otitis media. Coates has reported very good results. Additional treatment may be carefully given, but not infrequently more harm than good is done by careless flushing and cleansing of the auditory canal, whereby deeper and healthy tissues become infected. Free drainage should be afforded, and in chronic otitis media necrosed ossicles and granulations may require surgical removal. Injections may be given every five to seven days. A slight increase in discharge after the first one or two doses is of good import, and indicates a slight focal reaction. With Weston, I have treated a large number of cases of suppurative otitis media following scarlet fever, and whale the results were seldom brilliant, in general, the duration and severity of the infections were favorably influenced. While killed preparations of the typhoid bacillus have been injected soibcutaneously as a method of treatment hi typhoid fever since the work of Fraenkel1 in 1913, the subject is still in the experimental stage. An analysis of the literature upon this subject by Callison,2 Watters,3 and Krumbhaar and Richardson4 show that at best the ordinary type of heat-killed vaccine administered subcutaneously does no harm and may shorten the course of the disease, prevent fever relapses and complications and yield a slightly lower mortality. The treatment should be given early if at all, while the resistance and general condition of the patient is good. The injections are given subcutaneously and the doses should be modified in individual cases in order to avoid severe reactions. The initial dose may be 100,000,000 bacilli; three days later 250,000,000 or 500,000,000 may be injected, followed by three or four similar doses at intervals of five days. During convalescence two or more additional doses may be given in an effort to -prevent relapses. Garbat5 has found the subcutaneous administration of sensitized typhoid bacilli or serobacterin superior to the non-sensitized vaccine. Chickering1 have reported upon the treatment of 53 cases of typhoid fever with intravenous injections of Vo" to 2T milligram of a sensitized, polyvalent, killed typhoid vaccine sediment prepared after the method of Gay and Claypoole. The mortality was 9 per cent.; in 66 per cent, of the cases a distinct benefit was obtained, as shown by lowered temperature, disappearance or amelioration of subjective symptoms, and an apparently accelerated recovery. These effects have been attributed to the production of hyperleukocytosis and various antibodies in the patient's blood. In the treatment of complications, as periostitis, glandular suppuration/ cholecystitis, and similar complications due to localized infections, a typhodd vaccine may be of considerable aid. The vaccine should be autogenous if possible, and mixed if the lesions are open and other bacteria of probable pathogenic activity are found. Stone2 has reported favorably upon the treatment of cases of typhoid carriers with the ordinary vaccine, and it would appear that this form of treatment While pneumococcus vaccine has been employed by a large number of physicians in the treatment of lobar pneumonia, the curative value of this procedure is very doubtful. Stoner,8 Allen,4 Morgan,5 Harris,6 and others have reported favorably upon the vaccine treatment of pneumonia as based upon mortality statistics and clinical impressions; Charteris,7 on the other hand, failed to observe beneficial results. Rosenow and Hektoen8 have prepared a vaccine of partialty autoloyzed pneumococci which they believe proved of value in the treatment of pneumonia. In view of the fact that different types or strains of pneumococci may produce the disease, a vaccine if employed at all should be autogenous; if a stock vaccine is employed, it should be polyvalent and contain at least type strains I and II. It is difficult to find support for active immunization in such an acute and relatively brief disease as lobar pneumonia, and if a vaccine is employed it should be given as early as possible. In the treatment of delayed resolution and empyema, autogenous vaccines prepared of cultures secured from the sputum or by puncture may be of considerable value. OTHER ACUTE GENERAL INFECTIONS Autogenous vaccines may also be of service in the treatment of puerperal sepsis and ulcerative endocarditis, especially after the more acute symptoms have subsided. In the former condition a streptococcus may be obtained by blood culture or by intra-uterine cultures; in the latter, the infecting microorganism is obtained only by blood culture. Stock vaccines may be administered, but are not likely to prove of value, as both infections are usually caused by streptococci, pneumococci, or some similar microorganisms showing so much difference in individual properties as to make the use of autogenous vaccines imperative. The initial doses should be small — not over 50,000,000 cocci; they may be repeated every three to five days, and are gradually increased as the conditions warrant. In bacillary dysentery vaccine treatment has not given particularly favorable results. If employed in treatment the vaccine should be prepared from the microorganism isolated from the feces of the patient. Historic. — Within the last twenty years the subject of tuberculin therapy has elicited considerable discussion in the diagnosis and treatment of tuberculosis. The wide-spread prevalence of the disease, not only in man, but in the lower animals as well, the distressing symptoms, the gloomy prognosis, and the economic importance it possesses, are a few of the factors that have stimulated investigators the world over to zealous and persistent efforts directed toward discovering a means of preventing and curing this great scourge. Owing to the nature of the infection, which covers relatively long periods of time, and the fact that much time is required for the conduct of experimental studies, researches are of necessity prolonged, tedious, and difficult. Within a period of less than six years the cause of syphilis has been discovered and isolated, and valuable diagnostic reactions and a well-nigh specific therapy have been devised. The discovery of an early and specific diagnostic and therapeutic measure for tuberculosis will achieve still greater triumphs — in fact, few could be greater or more beneficial. Koch was the first to note the curative action of tuberculin, and it may be well to refer here to the original description of his fundamental experiments,1 which have been the basis as well as the starting-point of the entire study of tuberculins. "When one vaccinates a healthy guinea-pig with a pure culture of tubercle bacilli, the wound, as a rule, closes and in the first few days seems to heal. However, in from ten to fourteen days a hard nodule appears which soon breaks down, leaving an ulcer that persists to the time of death of the animal. There is quite a different sequence of events when a tuberculous guinea-pig is vaccinated. For this experiment animals are best suited that have been successfully infected four to six weeks previously. In such an animal the inoculation wound likewise promptly unites. However, no nodule forms, but on the next or second day after a peculiar change occurs. The point of inoculation and the tissues about, over an area of from 0.1 to 1 cm. in diameter, grow hard and take on a dark discoloration. Observation on subsequent days makes it more and more apparent that the altered skin is necrotic. It is finally cast off, and a shallow ulceration remains, which usually heals quickly and permanently without the neighboring lymph-glands becoming infected. Inoculated tubercle bacilli act very differently then upon the skin of healthy and tuberculous guinea-pigs. This striking action is not restricted to living tubercle bacilli, but is equally manifested by dead bacilli, whether they be killed by exposure to low temperature for a long time or to the boiling temperature, or by the action of various chemicals. "After having discovered these remarkable facts, I followed them up in all directions and was further able to show that killed pure cultures of tubercle bacilli ground up and suspended in water can be injected in large amounts under the skin of healthy guinea-pigs without producing any effect other than local suppuration. Tuberculous guinea-pigs, on the other hand, are killed in from six to forty-eight hours, according to the dose given, by the injection of small quantities of such a suspension. A dose which just falls short of the amount necessary to kill the animal may produce extensive necrosis of the skin about the point of injection. If the suspension be diluted until it is just visibly cloudy, the injected animals remain alive, and if the administration is continued with one to two day intervals, a rapid improvement in their condition takes place; the ulcerating inoculation wound becomes smaller and is finally replaced by a scar, a process that never occurs without such treatment; the swollen lymph-glands become smaller; the nutrition improves, and the disease process, unless it is too far advanced and the animals die of exhaustion, comes to a standstill. TUBERCULOSIS TUBERCULIN THERAPY 715 suitable for practical use, since they are neither absorbed nor disposed of in other ways, but remain a long time unaltered at the point of inoculation and occasion smaller or larger abscess. " Koch showed further that while the injection of tuberculous guineapigs with large doses of tubercle bacilli produced rapid death, frequently repeated small doses exerted a favorable effect upon the site of infection and the general condition of the animals. The same observer also realized that the harmful effects of injections of dead tubercle bacilli were due to the non-absorbable parts of the bacilli. He attempted to extract the immunizing substances, and in this way produced his first or Old Tuberculin. When injected into tuberculous guinea-pigs, old tuberculin produced a rapid general reaction without any local necrosis or sloughing, whereas when injected into a healthy guinea-pig, no reaction, either local or general, was produced. The fact that the general results produced by old tuberculin were analogous to those obtained by his first vaccine, except that local necrosis did not occur, induced Koch, in 1891, to promulgate it as a specific cure for tuberculosis in human beings. It is hardly necessary to describe the hopeful anticipation with which it was received, and the keen disappointment that followed its earlier clinical use. .Indiscriminate use, extravagant expectations, and excessive dosage combined to yield results so discouraging as to swing the pendulum of medical opinion so far the other way that even now the very word " tuberculin " suggests to many minds failure, and something to be avoided. A few earlier followers of Koch continued their studies in the endeavor to discover the causes of failure in tuberculin therapy. Their researches have led to new principles in treatment and to more exact knowledge of its indications, as well as its contraindications. As now employed, its use being restricted to suitable patients and administered in safe graduated doses, and accepting as evidence only the statements of those who have used tuberculin and not of those who believe it to be dangerous and have never used it, one deduction is justified: that while tuberculin is not a specific "cure" for tuberculosis, — any more than hygiene, diet, and climate are cures, — it helps to arrest the disease and is in general a useful factor in the treatment of certain types of the disease. Clinical studies have shtfwn, however, that immunization of the tuberculous patient is frequently a difficult procedure, owing to the fact that such patients are prone to develop a remarkable state of hypersusceptibility, may be injurious to the patient. Preparation of Tuberculins. — The knowledge that tubercle bacilli and their secretions as seen in vitro contain both desirable and undesirable substances has led Koch and others to adopt different methods of preparing tuberculin in the endeavor to obtain the .desirable immunizing principles in as pure a state as possible. As a consequence, a large number of preparations have been advocated from time to time, all of which are said to possess some special properties and virtues. All tuberculins, whatever their mode of preparation and manufacture, are derived from cultures of the tubercle bacillus. So numerous have the tuberculins become, and so superior are the advantages claimed for each new product over the older ones, both for diagnostic and for therapeutic purposes, that only a few of those possessing special interest and value can here be described. 1. Old Tuberculin (0. T.). — This is Koch's original tuberculin, and is the variety regarded by many as the most useful both in diagnosis and in treatment. Its manufacture was based upon the principle, that the toxins elaborated by the bacilli into the culture-medium or liberated by disintegration of the bodies were chiefly concerned in stimulating body-cells to the formation of antibodies. Since the bacillary bodies were regarded as mainly responsible for the production of abscesses at the point of inoculation, they are eliminated by a process of filtration. Old tuberculin is prepared as follows: Large shallow flasks containing 5 per cent, of glycerin alkaline broth are inoculated with a culture of human tubercle bacilli and grown at body temperature for from six to eight weeks, at the end of which time the bacilli have grown into a flat sheet covering the surface of the fluid (Fig. 137). The entire contents are then subjected to a current of steam over a water-bath for the purposes of sterilization and for concentration into one-tenth of the original volume. The glycerin, which is not evaporated, thus constitutes 50 per cent, of the resulting mixture. The bacilli are removed by filtration through a Berkefeld or Chamberland filter. The filtrate is a clear, brown fluid, of a characteristic odor, which keeps indefinitely and is ready for use. Koch considered the soluble toxins of the bacillus as the desirable immunizing agents, and believed that the endotoxins were responsible for the necrotic effects. Since, however, it was accepted that bacteriolytic substances would be formed only after the injection of intact or fragmented tubercle bacilli, — with their contained endotoxins, — Koch added T. R. and later B. E. to his list, in order to make the production of antibacterial substances still more complete. Furthermore, in order to obtain as varied a supply of antibodies as possible the use of several tuberculins, such as old tuberculin and bacillus emulsion, was recommended for use in the same patient. 2. New Tuberculin (Known as T. R. or Tuberculin Residue). — This was the next tuberculin to be promulgated by Koch,1 and is prepared as follows: Virulent cultures of human tubercle bacilli are grown in flasks of nutrient glycerin broth for from four to six weeks, the bacilli being then filtered off and dried in a vacuum. One gram of the dried tubercle bacilli is ground in an agate mortar until all the bacilli have been broken up. To the pulverized mass 100 c.c. of distilled water are added, and the mixture is then centrifugalized. The clear supernatant fluid is poured off, and is now known as Tuberculin Oberes (T. O., not to be confounded with O. T.). It contains substances not precipitable by glycerin. The sediment is again dried, powdered, taken up in a small amount of water, centrifuged, the supernatant fluid poured off, and the process repeated until no sediment is precipitated except that composed of gross accidental particles. The fluids resulting from all the centrifugalizations, except the very first, are poured together and the total should not measure more than 100 c.c. This opalescent fluid is preserved with 20 per cent, of glycerin and is known as T. R. It should contain 1 Deutsch. med. Wochenschr., 1897, xxiii, 209. grams of dried tubercle bacilli. 3. Bacillen Emulsion (B. E.). — This was a still later form of tuberculin made by Koch,1 and, as its name indicates, it is an emulsion of tubercle bacilli. The culture is grown as for 0. T.; the bacilli are filtered off, ground, but not washed, and one part of the pulverized material emulsified in 100 parts of distilled water; an equal part of glycerin is then added, making a 50 per cent, glycerin emulsion, each cubic centimeter of which contains the immunizing substances of 5 mg. of dried tubercle bacilli. Since B. E. was not washed, it was assumed that it would retain all extractives and the entire contents of the bodies of the tubercle bacillus. While Koch was preparing these various tuberculins others were being made, one of which, prepared by Denys, is used extensively at present in the treatment of tuberculosis. 4. Bouillon Filtrate (B. F.). — This is practically Koch's old tuberculin unheated. It is prepared in the same manner as 0. T., except that the- bacillus-free filtrate — a clear fluid said to contain only the soluble secretions of the bacilli, plus the metabolized culture-medium — is not heated or concentrated and is ready for use without any further modification. 5. Beraneck's Tuberculin. — This is a preparation for which its inventor claims only minimal toxicity and a high content of specific substances. It is prepared by cultivating the bacilli on a non-peptonized 5 per cent, glycerin bouillon medium, which is not neutralized. The filtrate from this culture is known as T. B., or toxin bouillon. The residue is shaken for a long time at from 60° to 70° C. with 1 per cent, orthophosphoric acid. Equal volumes of the unheated toxin bouillon and of the acid extract of the bacillary bodies are combined to form the whole tuberculin. 6. Von Ruck's Watery Extract* — This tuberculin has been widely used in the United States. It is prepared as follows: Concentrate a culture in vacuo at 55° C. to one-tenth volume (this requires about one month). Filter through paper and then through porcelain. Precipitate with an acid solution of sodic bismuth iodid. Filter and neutralize the acid solution. Filter again. Precipitate with absolute alcohol to make 90 per cent, alcohol and filter. Wash the precipitate with absolute alcohol. Dry the precipitate and make a 1 per culin. 7. Dixon's Tubercle-bacilli Extract.1 — Dixon has prepared a tuberculin by treating cultures of tubercle bacilli with ether and extracting in salt solution. This has yielded good results in the treatment of tuberculosis. This product is prepared from the living organisms. The tubercle bacilli are grown on 5 per cent, glycerin veal broth for a period of from six to eight weeks at a temperature of 37.5° C. They are removed from the incubator and collected on hard filter-paper. The filtrate of glycerin broth on which they are grown is discarded. An equal quantity, by weight, of tubercle bacilli of the bovine and human type is used. The mass of organisms is partially freed from excess of moisture by placing it between two sterile filter-papers, after which it is placed in a dish in the incubator for from twenty-four to forty-eight hours. The dried organisms are then washed in an excess of ether, which is allowed to act until it has removed all the water and glycerin. The organisms are then subjected to an excess of fresh ether and washed in this for six hours, to soften the wax of the bacilli. This fat separates so that it collects at the bottom of the vessel and is removed with a Pasteur pipet. After the second addition of ether has been removed the mass is allowed to dry until no ether odor is perceptible. After the mass of tubercle bacilli has been thoroughly dried it is ground in a mortar and suspended in physiologic salt solution in the proportion of 1 part of the ground mass to 5 parts of an 8 per cent, salt solution. This suspension is shaken in a shaking machine for from eight to ten hours, and is then allowed to stand for several days at room temperature. It is finally passed through impervious bacteria filters several times and the filtrate examined microscopically, bacteriologically, and physiologically. Culture tests are made to determine its freedom from contaminating organisms, and guinea-pigs are inoculated to ascertain that it contains no living tubercle bacilli. One cubic centimeter of this extract represents 0.2 gm. of the organisms, and is known as the stock solution, from which serial dilutions are made. This solution is sterile, but 0.5 per cent, of phenol (carbolic acid) is added as a preservative to prevent subsequent contamination. cerned in producing necrosis, but likewise the protein constituents responsible for specific sensitizing action and anaphylactic disturbances. For example, tuberculocidin and tuberculol are examples of attempts at isolating the pure immunizing principle; endotin, or Moeller's tuberculin, is an example of an endeavor to rid the culture fluid of protein substances.1 Action of Tuberculin. — If a healthy or a tuberculous individual is injected with old tuberculin, an immunity will be established only against the substances contained in this preparation. That this does not fulfil the requirements is proved by the fact that an animal immunized against this tuberculin will not be protected against a later infection with living tubercle bacilli. It was mainly for this reason that tubercle emulsion and new tuberculin were devised and used, in the effort to provide immunization not only against the products of the bacilli, but against the bacilli themselves, and to bring about their actual destruction. Probably none of the various tuberculins can be considered as representing the true toxins of the tubercle bacillus, although they simulate these substances with sufficient closeness to bring about partial immunity against some of the poisonous products and to warrant their use in tuberculosis. An individual may become immunized against old tuberculin so that large doses will evoke no reaction, but this does not necessarily imply that a cure has resulted; in fact, the injection of another preparation, such as new tuberculin or bacillus emulsion, may bring about a reaction. Partial immunization possesses, however, distinct advantages, in that it lessens some of the symptoms of tuberculosis. In addition, tuberculin immunization may give most important aid in walling off tuberculous foci with fibrous tissue, and in this manner bring about a condition of potential cure. Following the injection of tuberculin a focal reaction occurs, characterized by hyperemia and exudation about the diseased tissues. While an excessive dose of tuberculin may produce excessive hyperemia, exudation, and necrosis of tuberculous tissue and lead to actual harm, these being some of the effects that followed the early use of tuberculin and resulted in bringing it into high disfavor, smaller and carefully graduated doses tend to produce a mild inflammatory hyperemia leading to destruction of tuberculous tissue and the there is also associated the local production of antibodies. The Use of Living Tubercle Bacilli. — Any vaccine that will give complete immunization against the tubercle bacillus and all its products, in addition to a healing focal reaction of the right degree, will prove of the greatest value in active prophylactic and curative immunization. As has been stated repeatedly, this is probably best obtained by using living cultures in such form that they cannot produce the disease. Obviously, it is a difficult matter to find such a culture or to modify one to meet the requirements at hand. When this problem is solved, it may then be possible to provide universal prophylactic immunization and to aid the actually diseased in overcoming their infection. At present the tuberculins are not adapted for prophylaxis because they possess only partial immunizing powers, although these effects may be of distinct aid to the tuberculous patient, in addition to producing a focal reaction of value in walling off a lesion and producing local antibodies. Probably the first work done with the living bacillus was that of Dixon1 with attenuated cultures. This worker found that animals inoculated with an old culture containing club-shaped and branching forms of tubercle bacilli would resist subsequent inoculation with virulent organisms. Since then numerous investigators — Trudeau,2 Pearson,3 de Schweinitz,4 McFadyean,5 Levy,6 Pearson and Gilliland,7 Behring,8 Thomassen,9 Neufeld,10 Theobald Smith,11 Webb and Williams,12 and others — have, either directly or indirectly, supported this original work, thus indicating that the most effectual active immunization is secured by using living cultures. The method employed by Webb and Williams is worthy of special mention, inasmuch as the ascending doses of bacilli are actually counted by an ingenious method devised by Barbour.1 These observers used this method quite extensively with lower animals, and have also secured good results with persons willing and anxious to take all possible risks for the possible good that may result. In no case have harmful results followed the injections. More recently the profession and laity have been agitated by the extravagant claims of Friedmann for a vaccine of living, acid-fast bacilli derived from the turtle. This culture is said to be avirulent for human beings, and to be capable of stimulating specific antibodies and thus bringing about a cure. The unfortunate methods by which these claims have been exploited, and the more recent investigations, tending to show that no good has followed its use, and that the vaccine is not entirely harmless, preclude any statements at this time. The principle involved, however, namely, the use of a living vaccine composed of microorganisms so altered by passage through a lower animal that they cannot produce tuberculosis in the human being, but yet resembling the human bacillus closely enough to 'produce specific antibodies, is sound, and should stimulate further experimental research in this direction. Patients Suitable for Tuberculin Treatment. — In deciding which tuberculous patients are best suited to receive tuberculin treatment it must be borne in mind that tuberculin is not a form of passive immunity, depending upon antitoxins, bacteriotropins, and bactericidins, but that it serves to stimulate the body-cells to produce these protective substances. The output of antibodies provoked by tuberculin is dependent upon the condition of the body as a whole, and its administration can be of no help if the resources of the body are exhausted and the cells are incapable of beneficiary reaction. In other words, tuberculin therapy must be guided by the same considerations that influence the vaccine treatment of acute infections in general. 1. Patients afflicted with incipient tuberculosis are proper subjects for receiving tuberculin treatment, since it tends to protect them from relapse, and insures, to a greater degree, their ability to continue work. 2. Advanced and moderately advanced cases may be given tuberculin if the nutrition is fair, the febrile reaction mild, the pulse not very rapid, and if the treatment is controlled by rest. Old fibroid cases with fair nutrition are especially suitable, as such patients become capable of moderate activity and are much less likely to suffer from relapses. ceiving tuberculin treatment. 5. The question arises as to whether tuberculin may be administered to ambulant patients. Tuberculin should be regarded as but one factor in the treatment of tuberculosis, and, as such, should be combined with the best therapeutic measures available. Therefore the tuberculin treatment is supplementary to rest, hygiene, and fresh air, and the benefit of the sanatorium should not be denied to patients, especially to the poorer ones. The treatment of a mildly progressive ambulant case should be undertaken only when prolonged rest in bed has had no visible effect, and when no measures can be devised for administering the tuberculin while the patient is in bed, as, e. g., patients who have been at the sanatorium and have returned to work, or those who cannot be persuaded to enter a sanatorium or for whom no place can be found. The tuberculin treatment of more chronic or localized tuberculosis may be successfully undertaken in the clinic or office. Contraindications to Tuberculin Therapy. — Owing to the increased focal hyperemia that follows the injection of tuberculin, hemoptysis has been considered a contraindication to its use. In such cases it is well to wait for some time at least and begin the injections with very small doses, as the ultimate effect, namely, the production of fibrous tissue, may be of great aid in prolonging life. Various authorities have expressed different views regarding other contraindications, such as marked general weakness, fever, cardiac disease, nephritis, epilepsy, syphilis, hysteria, etc. As was stated by Hamman and Wolman, these are not contraindications, but unfortunate complications that would embarrass any form of treatment. Tuberculin may be given to any patient whose resisting powers have not been too much depressed as the result of complications. For the beginner in this form of therapy, however, it is advisable that he acquire experience by undertaking the treatment of uncomplicated cases before assuming the responsibility of treating the more difficult ones. The fact that the ophthalmic test has been made is no contraindication to treatment by tuberculin if the reaction has subsided, since a flare-up rarely occurs except after large diagnostic doses (Hamman and Wolman). following the administration of tuberculin. He must know whether he does or does not wish to obtain symptoms of a tuberculin reaction during the treatment; the size of the initial and particularly of subsequent doses will depend upon his desire to obtain a reaction or upon his anxiety to avoid it. Reactions. — At the present time tuberculin is never used for the purpose of obtaining strong reactions, such as Koch originally insisted upon getting. Koch administered a dose large enough to elicit a strong constitutional reaction, and repeated it at intervals of one or more days until that dose no longer produced a reaction, after which a still larger dose was given and the former procedure repeated. Many — too many — were unable to pass through this therapeutic furnace unsinged, and, in fact, the results obtained led to the period known as the " tuberculin delirium, " ending, as Hamman and Wolman stated, " to the consequent downfall of the arrogant therapy to an humble position, whence it is but just emerging, chastened and refined, to assert its modest but now truthful claims to a therapy less spectacular but more healing, less forceful but more gently persuasive: healing a few, helping many, and hur ting none. " While there is this general unanimity of opinion regarding the harmful effects of strong reactions, yet tuberculin therapeutists may be divided into those who scrupulously avoid all reaction, those who are a little bolder and do not object to a very mild reaction, and to an intermediate class. In the first group are Sahli and Trudeau; the former claims that it is essential, first of all, to do no harm, and that cases treated cautiously attain a tolerance for high doses as soon as, and even sooner than, those that are rushed. Petruschky is an exponent of the bolder method, believing that, by proceeding very cautiously, much time is wasted and not enough focal reaction is produced to promote healing. To the intermediate class, and approaching rather the timid class, are Bandelier and Roepke, Hamman and Wolman, and many others. These observers adopt no scheme of fixed dosage, but study the individual patient, remembering what is to be avoided, rather than the high dose to be reached. The constitutional symptoms of a reaction are: temperature, loss of weight, rapid pulse, and general symptoms, such as malaise, headache, chilliness, arthritic pains, gastric or intestinal disturbances, nausea, loss of appetite, insomnia, and skin eruptions. for several days preceding the initial dose, so that the patient's " normal" limits are known before the tuberculin is given. When the usual maximum temperature is reached, it is especially necessary to watch closely for additional signs of reaction. Without some constitutional disturbance a slight pyrexia is of less significance, and it is to be remembered that tuberculous patients may have a flare-up of fever when they are not being treated with tuberculin. Denys refuses to consider any temperature reaction as due to tuberculin that comes on more than forty-eight hours after the injection has been given. It is characteristic of tuberculin reactions that the rise is abrupt, and not in step-like progression. Hamman and Wolman would hesitate to ascribe an elevation coming on suddenly in the midst of a perfectly smooth course of tuber-, culin treatment, and unaccompanied by a local reaction, to the injections, when the dose has not been unduly large. denly appearing reactions. Bandelier and Roepke regard an increase in the pulse-rate as a sign of great importance. Hamman and Wolman and Lawrason Brown have not been able to observe this sign very frequently. The local signs are: Pain, tenderness, and swelling at the site of injection. These may consist of all gradations from simple thickening of the skin to a wide, deep, hard, and painful node, with or without involvement of the neighboring lymphatics. The local reaction has assumed great importance in recent years, especially since Denys drew attention to it as serving as a warning of the approach of a general reaction. It is characterized by the development of pain, tenderness, and redness about the site of a former injection. It is more often solitary than any other sign, and, in the absence of a temperature record, it is safe to proceed, the sole guidance being the local reaction, both subjective and objective. A large dose of tuberculin may give a local reaction, due merely to its bulk and concentration (500 to 600 mg.), simulating a true reaction; this may be avoided by dividing the dose into two injections, which are given at the same time, but not into neighboring areas of skin. Unless one belongs to the ultra-conservative class of tuberculin therapeutists, it is not a slight focal reaction that is to be avoided, but those reactions that are large enough to manifest themselves by changes in the physical signs or by decided symptoms. On the contrary, it is the production of such slight hyperemia about the focus of disease that constitutes the most valuable result of tuberculin therapy. It is well to start with a minute dose, and push the dosage rapidly until a slight focal reaction at the site of injection or mild pyrexia is observed. When a mild focal reaction is not produced, the patient is not receiving his due amount. Dosage. — Since each patient is a law unto himself, the initial dose should be so small that no harm can result from its use. White and Van Norman make the initial dose equal to the quantity of tuberculin which, when applied cutaneously, will elicit a minimal reaction after seventy-two hours. As regards the size of the initial dose, patients can be divided into three classes: (1) Children; (2) patients who exhibit a slight pyrexia or are not in good condition; (3) patients in good condition. The following table of doses is that given by Hamman and Wolman, the smaller initial dose being for classes 1 and 2, the larger for class 3. B. E.. . 0.0000001 c.c. to 0.000001 c.c. 0.000001 c.c. to 0.0001 c.c. 0 000001 c c to 0 0001 c c Of H, 1 c.c. Old tuberculin (0. T.) is put up in ampules holding 1 c.c. and 5 c.c. From these, higher dilutions are prepared by adding sterile normal salt solution, using sterile glassware, starting with a 1 : 10 (A) of the original strength, then making a 1 : 10 from this (B), a 1 : 10 from that (C), a 1 : 10 from that (D), and so on to the desired dilution. As 1 c.c. of the original product represents 1000 milligrams of the pure tuberculin, 1 c.c. of dilution A will contain 100 milligrams; B, 10 milligrams; C, 1 milligram; D, 0.1 milligram; E, 0.01 milligram, and F, 0.001 milligram, which is the higher of the initial doses just given. similar to the foregoing by diluting the original product 1 : 10 (A) ; 1 c.c. of this is in turn diluted to 1 : 10 (B); of this, 1 : 10 (C); and of this, 1 : 10 (D); 1 c.c. of A contains 0.5 milligram; 1 c.c. of B, 0.05; 1 c.c. of C, 0.005, and 1 c.c. of D, 0.0005 milligram. Beraneck's tuberculin is marketed, ready diluted, in a series of syringes, A/128, A/64, A/32, to A/4, A/2, A, B, C, to H. H is the pure tuberculin. Each solution is one-half the strength of the next stronger one. The increase of dosage is usually by 0.1 c.c. until 0.5 c.c. is given. Then 0.1 c.c. of the next stronger dilution is given, and so on. stronger dilution. As a general rule, the succeeding doses of a tuberculin may be increased by 0.1 c.c., due care being exercised when the dilutions are changed. If the patient is quite sensitive, it may be well to repeat the first dose of each stronger solution once or more often as it is reached, and, instead of proceeding to 0.2 c.c., give only 0.15 c.c., thus tiding over the gap. If the patient is not so sensitive, a few leaps may be taken with the weaker dilution, so as to test the patient's tolerance, and, if it is good, the next higher dilution is given at once. Site of Injection. — Injections are probably best given in the back, at the lower angle of the scapula. Local reactions are more reliable here than when the injections are given in the arm. All injections should be given under aseptic precautions and with a sterilized syringe, in exactly the same manner as any bacterial vaccine is given. All injections should be subcutaneous; intramuscular injections are venous injections. Time of Injection. — There is some difference of opinion as to the best time of the day for administering tuberculin therapeutically. If given in the morning, a slight febrile reaction may occur during the evening which would otherwise be overlooked. Brown is in favor of the afternoon as the most suitable time, because it affords an opportunity for omitting the dose in case there is an accidental rise of temperature on that day. On the other hand, it is contended that the rest at night would tend to prevent the occurrence of the reactions that might appear if the patient were up and about. While it is not essential that the patient rest for a few hours after a dose has been administered, this is advisable, and where absolute rest can be enforced, the dosage may be increased with greater rapidity than in ambulant patients. Interval Between Doses. — The interval between injections is usually from three to four days — i. e.^fwo Injections a week. This interval is merely tentative, and while it should not be shortened, it may be necessary to prolong it. While most reactions set in within from twentyfour to thirty-six hours, some may begin as late as from forty-eight to sixty hours (L. Brown). By waiting at least three days we may be assured that, if no reaction has occurred, none will take place. The usual interval is maintained as long as the patient is doing well. After a while the patient becomes intolerant and exhibits slight reactions, depression, and loss of weight. In such instances the interval may be increased to a week and the injections continued. Hamman and Wolman find this occurrence so frequent that they advise creasing the dose interval to one week, when the dose of 100 mg. of 0. T. is reached, 200 mg. of T. R. and B. E., and 50 mg. of B. F. 2. Other Routes for the Administration of Tuberculin. — Oral Route. — It has been shown that reactions may follow the oral administration of tuberculin. But absorption is so irregular that a quantity of tuberculin may be absorbed suddenly and cause unexpected reactions. Much depends, apparently, upon the state of digestion and upon the condition of the alimentary tract. The oral route also deprives the physician of the benefits to be obtained from using the local reaction as a guide. Otherwise the method is simple and the tuberculin may be administered in the form of tablets or in capsules. It is important, however, to exercise supervision over the patient. S. Solis Cohen has used a modification of Latham's method, and reports favorable results: "Tuberculin residue (T. R.) triturated with milk sugar is given with skim milk, whey, or beef-juice. The initial dose is 0.000001 mg. Both subjective and objective symptoms of reaction are watched for. The dose is repeated once or twice weekly, according to results. It is gradually increased by increments of 0.000001 mg. to the reaction point, and then dropped one point lower, and so continued for some weeks. Later, a further increase is attempted, and if reaction is not shown, is proceeded with in a similar gradual way. The arbitrary increment of 0.000001 mg. is maintained during this remittent progression until 0.0001 mg. has been reached. After that the increment may be raised to 0.00001 mg. Thus, by successive stages, a maximum dose is attained at a point determined for each individual by all the factors in the case, including the rapidity of increase, character and intensity of reaction, and maintenance of tolerance, as well as the focal and general signs of improvement. The treatment is continued with intermissions for many months, and may be resumed, if necessary, from time to time over a period of years. " rectum without good results. Koch was the first to administer tuberculin intravenously, but this route has not come into general favor, owing to the fact that even greater control over dosage is necessary; there is, besides, no local reaction to serve as a guide, and technically the administration is more difficult than is subcutaneous injection. The Intrafocal Route. — The use of tuberculin intrafocally, that is, a method by which the tuberculin is brought into immediate contact with the diseased area, has been advocated in the treatment of tuberculous pleurisy, tuberculous peritonitis, and tuberculosis of other serous membranes, such as those lining joints, the tunica vaginalis of the testicle etc. Senger, Crocker, and Fernet advise the intrafocal use of tuberculin in the treatment of lupus; others have applied it directly to broken-down glands and to sinuses. William Egbert Robertson1 has reported very good results in two cases of tuberculous pleurisy as a result of withdrawing a small amount of fluid and injecting 5 mg. of old tuberculin through the needle, which is left in situ for that purpose. After some hours there was a slight reaction; the remainder of the fluid was rapidly absorbed, and convalescence was promptly established, 1 Personal communication. though, of course, a damaged lung remained. In a case of hydrocele the injection of old tuberculin was followed by a sharp local and a moderate general reaction, followed by absorption, and without the slightest evidence of recurrence to date, now about a year since the injection was made. Results of Tuberculin Therapy. — The early and disastrous results obtained with tuberculin in various types of tuberculosis cannot be used at the present day as a measure for determining the therapeutic value of tuberculin. So much depends upon the individual case, the duration and activity of the disease, the possibility of supplementing the active immunization with sanatorium treatment, the skill and patience of the physician, etc., that, from a prognostic standpoint, every case must be judged upon its own merits. The results of the modern use of tuberculin show quite clearly that it is not a "cure" for tuberculosis, but, rather, a rational and useful therapeutic aid, the best results being secured when the treatment is carried out in special institutions or by specially trained physicians who have a practical knowledge of the difficulties, dangers, and possibilities of tuberculin therapy. The value of this or of any therapy can be judged according to various standards: (1) Working ability; (2) duration of life; (3) the presence of tubercle bacilli in the sputum; (4) physical signs, and (5) the symptoms. welcomed. Kremser chose 110 patients expectorating tubercle bacilli and treated 55 unselected cases with tuberculin; of these, 22, or 40 per cent., lost the bacilli from their sputum; of those treated without tuberculin only 16, or 29 per cent., lost their bacilli. Phillippi found that 58 per cent, of his second stage cases were rid of bacilli in the sputum under tuberculin treatment, as against 19 per cent, without. Brown reports from Saranac Lake that, in the incipient class, 67 per cent, of the tuberculin patients were rid of bacilli; of the others, 64 per cent. In the moderately advanced the figures are respectively 44 per cent, and 24 per cent. Bandelier gives the reports of 500 cases, of whom 202 had tubercle bacilli in the sputum. In the following table he compares the working capacity and sputum examinations of these patients under tuberculin treatment : The parallelism between the bacillary content of the sputum and the working capacity is close and shows the value, from a statistical point of view, of sputum examinations. Healing with and without tuberculin is qualitatively the same, although, in the opinion of Ziegler, Petruschky and Rohmer, Pearson and Gilliland, Jurgens, Neumann, and others, quantitatively the results are different, all authors agreeing on the presence of more fibrosis about the lesions than is usual in the untreated cases. Autopsy findings necessarily point with less favor to tuberculin therapy than do clinical facts bearing on the rapidity and permanency with which a lesion heals. The influence of tuberculin cannot at present be judged from the presence of antibodies in the serum, as data bearing upon the presence or absence of antitoxins, opsonins, agglutinins, and bacteriolysins are insufficient. General symptoms and signs, such as fever, cough, loss of weight, accelerated pulse, digestive disturbances, dyspnea, and pain, if they are due to tuberculosis, as a rule improve under tuberculin treatment. Under proper conditions the incidence of hemoptysis is not usually increased, and the quantity of sputum and number of expectorated bacilli gradually decrease. In the treatment of tuberculosis of the eye tuberculin has yielded exceptionally good results; in tuberculous adenitis considerable good may be accomplished with those glands that have not as yet softened. In bone and joint tuberculosis there is a growing opinion that surgery may be obviated or supplemented by tuberculin. In tuberculosis of the ear, tuberculin has yielded good results and should always be used. The results in tuberculosis of the skin have been generally disappointing, and when tuberculin is administered, the treatment should be prolonged and supplemented by the usual therapeutic measures. Tuberculosis of the intestine and mesenteric glands may be benefited, and in subacute tuberculous meningitis this method of treatment may also be tried, combined with lumbar puncture to relieve intracranial pressure. In tuberculosis of the genito-urinary organs the prognosis is largely dependent upon the accompanying pulmonary condition and upon the extent of the local process. There is general recognition of the value of tuberculin as an adjuvant to hygienic measures, although great difference of opinion exists as to surgical intervention. If one kidney is involved, most surgeons advise early operation, followed by tuberculin treatment; if both organs are diseased, tuberculin may prove a valuable adjuvant to the treatment. SERUM therapy may be said to have had its origin in 1890, when von Behring discovered diphtheria antitoxin. He found that guinea-pigs surviving a subcutaneous inoculation of living diphtheria bacilli may harbor virulent bacilli at the site of injection without showing any evidences of intoxication. Subsequent investigation showed that the blood-serum of these animals contained the protective principles, for when the serum was injected into other animals along with the diphtheria toxin, symptoms of the disease did not develop, and, indeed, as was shown later, the immune serum was found capable of neutralizing the toxin in the test-tube. Shortly afterward Kitasato made similar discoveries in studying tetanus, and these antitoxins have since proved of great importance, not only from the new light that has been thrown upon the mechanism of immunity, — and they were used as important arguments for the humoral as opposed to the phagocytic theory, and form the very basis and starting-point of Ehrlich's researches, — but also from the new and important field of therapy that was now opened, which gave promise and hope for the discovery of a specific serum treatment for each bacterial disease. At the time it was thought possible to immunize animals with the various microorganisms known to produce disease, and that the immune serums so produced may be employed in the form of specific treatment. This theory rested on the fact that they contained the antibodies that would quickly overcome the infection. With a few of the genuinely antitoxic serums these hopes have been realized; but many other serums have not yielded the expected and wished-for results, although at the present time the reasons for failure are being recognized and gradually eliminated. Definitions. — It will be remembered that -in active immunization our own body-cells are stimulated to produce antibodies, either by reason of the presence of a disease or as the result of vaccination with the antigen of the disease in a modified and attenuated form. In passive immunization, however, our own body-cells do not produce the antibodies, but we receive them passively in the form of an injection of an antibodyladen serum. The antibodies are produced by active immunization of some other animal, usually a horse, and we receive the antibodies or products of this immunization in a passive manner, i. e., our body-cells receive protection against an infection and aid us in overcoming it through antibodies produced in some other animal. For this reason the process is called passive immunization; the particular kind of increased resistance afforded against infection is known as passive immunity, and since bloodserum contains the antibodies and is the usual vehicle by which they are transferred, the method is called serum therapy. In prophylactic immunization the antibodies are introduced into our body-fluids before infection has actually occurred, or at least in the earliest stage of infection, for the purpose of placing them on guard to destroy the infecting microorganism or to neutralize its products before it has had an opportunity to produce disease. In other words, we aim to fortify our natural defenses by purchasing antibodies from another animal. From the fact that these antibodies may be introduced in a short space of time and that in this manner an immunity may be quickly gained, passive immunization for prophylactic purposes is indicated when the danger of infection is imminent, and when it is impossible, or when there is not sufficient time, for us to stimulate our own body-cells to produce our own antibodies by active immunization with a vaccine. Since the antibodies are produced in another animal, the serum, when introduced into our body-fluids, represents a foreign protein, and, accordingly, we find that the antibodies are retained for relatively short periods of time and are quickly eliminated or destroyed. In active immunization, however, the antibodies are in native surroundings, and our body-cells continue to produce them for some time after active stimulation has ceased, in this manner insuring a higher degree of immunity and one of longer duration. For purposes of prophylaxis, therefore, active immunization is always more desirable than passive immunization; not infrequently the two forms are used simultaneously, as the antibody-laden serum will afford instant protection, while the vaccine is stimulating our body-cells to produce antibodies that will VARIETIES OF PASSIVE IMMUNITY 735 increase and maintain the protection over a longer period of time. This mixed form of immunization has recently received special study by von Behring in immunization experiments against diphtheria, and will be considered in detail in a later section. In curative immunization the conditions are somewhat different. During the course of an infectious disease our body-cells are actively engaged in combating the infectious agent, so that reinforcements, in the form of specific antibodies, are indicated and welcomed for the aid they give in overcoming an infection and the relief they afford our hardpressed protective mechanism. For these reasons it may be stated that the more acute the infection, the greater is the indication for introducing an antibody-laden serum. In chronic infections and in some acute infections we may practise active immunization by introducing a vaccine, with the purpose in mind of stimulating dormant cells to produce antibodies; but, as a rule, it is reasonable to assume that in a severe generalized infection our bodycells are doing their utmost to overcome the infection, and extra stimulation may be actually harmful. By introducing antibodies produced in some other animal, however, practically no extra strain is thrown upon the body-cells; on the contrary, they may be relieved when the new antibodies overcome the products of infection, and in this manner afford them an opportunity to recover. Unfortunately, this is actually the case in but a few infections, such as diphtheria, tetanus, and cerebrospinal meningitis, and does not apply equally well to the larger number of bacterial infections due to the pneumococcus, streptococcus, gonococcus, and similar infections. The reasons for failure of passive immunization in the cure of the last-mentioned infections are now being studied and realized, and means are being discovered for overcoming the difficulties, so that serum therapy, in a broad sense, is about to play a more important role in the treatment of many bacterial infections. While, strictly speaking, all antibodies are probably inimical to their antigens, from the practical standpoint of passive immunization three are of primary importance, namely: (1) The antitoxins, (2) the bacteriolysins, and (3) the bacteriotropins (immune opsonins). The antitoxins neutralize their toxins; bacteriolysins cause the death of their respective bacteria if suitable complements are present, and bacteriotropins accomplish the same end by lowering the resistance of the bacteria, and in this manner facilitating phagocytosis. Other antibodies may be operative and prove of assistance, as, e.g., agglutinins may aid in bacteriolysis and anti-aggressins may aid in phagocytosis, but too little is known at the present time to allow fine distinctions to be made, although the indications are that not one but several antibodies are present in each immune serum, which, acting together, tend to overcome an infection. 2. Antibacterial immunization, due mainly to bacteriolysins and bacteriotropins, as in meningococcus, pneumococcus, streptococcus, gonococcus, and similar infections (antibacterial immunity). As will be pointed out further on, diphtheria antitoxin, when administered in sufficient amounts, affords protection for at least from four to six weeks; mixed immunization, by means of the simultaneous injection of a neutral mixture of the toxin and antitoxin, as worked out by von Behring, has been found to yield equally good and more prolonged immunity, but because of certain technical difficulties has not as yet been widely adopted. Tetanus antitoxin has its greatest value as a prophylactic. When symptoms of tetanus have once appeared, serum treatment may be of no avail, whereas it has proved its efficiency beyond doubt in neutralizing the toxin before it reaches or unites with the nervous tissue. In all wounds likely to be infected with tetanus the physician should include the administration of tetanus antitoxin as a matter of routine treatment. Of the antibacterial serums, many have a prophylactic value in experimental animals, but none, with the exception of the antiplague serum, is in general use as a prophylactic in human practice. The reasons for this are apparent when it is remembered that pneumococcus, streptococcus, and meningococcus infections are not sufficiently epidemic in character to demand passive immunization. Meningococcus meningitis may, however, be an exception, but the method of active immunization advocated by Sophian is promising, easier to carry out, and should be tried during times of epidemic meningitis. In typhoid fever, cholera, and dysentery antibacterial serums have not been generally used in prophylaxis, although it would appear that a potent anticholera serum would prove of value in preventing epidemics of this frightfully infectious disease. With the exception, therefore, of the true intoxications, prophylaxis is more readily secured by active than by passive immunization. This is certainly true of typhoid fever, rabies, and smallpox. The antiserums of other microorganisms, such as the pneumococcus, streptococcus, and gonococcus, are being used exclusively for therapeusis, rather than for prophylaxis, of their several infections. In veterinary practice hog-cholera serum has proved of value as a prophylactic means of combating and limiting epidemics of hog cholera. It is not definitely known whether this serum is antitoxic or antibacterial, but it is probably a combination of both. In the treatment of disease immune serums have proved of value in diphtheria, tetanus, cerebrospinal meningitis, and, to a lesser extent, dysentery, pneumonia, streptococcus infections, and plague. While antipneumococcus, antistreptococcus, and antigonococcus serums have proved of some value in the treatment of their particular infections, the more recent work of Neufeld and Handel, Dochez and Cole, and their coworkers in pneumonia indicates that there are wide biologic differences among various strains of these microorganisms, and that no curative properties can be expected from a given serum unless this is homologous for the type causing the infection. Further than this, it has been found impossible to secure serums as rich in antibodies as are secured with diphtheria and tetanus antitoxins, and that the serums must be given intravenously in relatively large doses. A method for the quick recognition of types of pneumococci has been worked out in the Rockefeller Hospital, and immune serums have been prepared for the main types, and the results of the serum treatment of pneumonia along these lines have been found to be most encouraging. While this method is not adapted for general use, it holds out a promise for the future of serum therapy, and opens up a wide field of investigation with the group of streptococci, gonococci, and meningococci. The chief contraindications to the therapeutic use of a serum, if any ever exist, are those dependent upon the serum itself, for, as will readily be understood, the introduction of antibodies themselves does not mean an extra strain upon our body-cells, but rather the reverse. The question before us, then, is one regarding the possible contraindications to the injection of a foreign serum, and the dangers dependent upon its use. It may be stated at once that, in the great majority of cases, the administration of a carefully prepared and properly administered serum is free from danger. Since the introduction of diphtheria antitoxin in the prophylaxis and treatment of that disease many thousands of injections have been given, in all parts of the world and under all sorts of conditions, and the number of fatalities is so small as to be regarded as almost negligible. Serum therapy should not, however, be abused to the extent of using the serum indiscriminately. I am opposed to using the serum as a prophylactic unless the indications for its employment are distinct; for example, in diphtheria it suffices to immunize only those who have been brought into immediate contact with the infection. When, however, the indications are clear and the symptoms of infection are present, I believe in using the serum early and generously. 1. Of all possible dangers consequent to the use of serum therapy, that of anaphylaxis is uppermost in the minds of practitioners. While it is true that anaphylaxis has been the cause of some fatalities, the likelihood of this accident taking place is so remote, in the great majority of cases, that it should not occupy "a prominent place in the physician's mind, nor interfere with the use of the serum, as, for instance, antitoxin in the treatment of diphtheria. It is true that serum sickness is comparatively common, and while the symptoms are frequently distressing, they are not dangerous and do not constitute the dreaded and fatal anaphylaxis. With a little discrimination and care on the part of the physician the risk of anaphylaxis may be rendered still more remote if attention is given to the following questions : (a) Is the patient sensitive to horse protein? This is probably the most important single question, as in several of the fatal cases of anaphylaxis on record it was learned afterward that the patient was usually rendered uncomfortable, and that sneezing, asthma, or even an urticarial rash woutd develop when the patient came into close proximity to horses, as in a stable, or when driving behind them, etc. Fortunately, these cases are very few, but several of the fatal cases of anaphylaxis on record occurred in just such persons, and at the present time a METHODS OF INOCULATION 739 physician should generally be able to detect this susceptibility and avoid the dangers of anaphylaxis. In Chapter XXVIII the subject is discussed in greater detail, and a method of vaccination is described by which it may be possible to detect this condition; this consists of rubbing a little of the serum into an abrasion on the arm (Fig. 125) . . (6) Has the patient been injected with a serum on any former occasion? If an injection has been given, especially a few weeks earlier, a reinjection of serum may cause well-marked serum sickness, but the possibilities of alarming anaphylaxis are so remote that serum should never be withheld if the clinical condition indicates that it should be given. Not infrequently a child receives an immunizing dose of diphtheria antitoxin, but develops the disease a month or two later, after the immunity has disappeared. Under these circumstances antitoxin should not be withheld. If time permits, the physician may inject 0.5 c.c. of the antitoxin for the purpose of producing anti-anaphylaxis, followed in two or three hours by the remainder of the serum. // it were possible to obtain it, it would be good practice to immunize the patient with an ox-serum antitoxin, and then, if it was found necessary later to use an antitoxin, the usual horse serum antitoxin could be employed. This would still further eliminate the possibility of the development of disagreeable or dangerous complications. 2. If a patient suffers from idiopathic asthma and the condition known as status lymphaticus develops, serum should be given cautiously because of the increased respiratory difficulties that may follow. It may be well to give a preliminary hypodermic injection of atropin and caffein, and then, after a few minutes, give the serum, injected slowly and subcutaneously. 3. Aside from these questions, the physician may be called upon to decide if a patient is physically able to withstand the effects of an inoculation, especially the intravenous injection of relatively large amounts of serumx such as are given in the treatment of pneumonia. In diphtheria in very young and weak children, when a large number of units or several injections are to be given, concentrated antitoxin is to be preferred, in order that injury to the subcutaneous tissues, pain, and shock may be reduced to a minimum. intravenously, or intraspinously (subdurally). In diphtheria, the antitoxin may be given subcutaneously unless the infection is quite severe; in the latter case it should be given intramuscularly or intravenously. In tetanus the serum should be given subdurally and intravenously. In epidemic cerebrospinal meningitis the serum is always given subdurally. In pneumococcus, streptococcus, and gonococcus infections, while the serum may be given subcutaneously or intramuscularly, it is best administered intravenously. It is important for the physician to know and appreciate that the route and method of inoculation and the amount of serum administered are important factors in determining the success or failure of serum therapy. Serum given subcutaneously is slowly absorbed, and a portion of the antibodies may be destroyed before they reach the blood-stream. When large quantities of serum are to be given, as in pneumonia and streptococcus infections, this method may not be permissible on account of the pain and injury to the subcutaneous tissues that may result, aside from the more important question of slow absorption and anchorage or destruction of the antibodies in various tissues before they reach the bloodstream or the focus of disease. 1. Injections should be given where the subcutaneous tissues are loose, where movement is least marked, and preferably where pressure upon the parts is least likely to occur, for some soreness, dependent upon the bulk of the injection, is bound to follow. For these reasons injections may be given in the abdominal wall; some prefer the back, in the region of the lower angle of one of the scapula, and the buttocks, but in a bedfast patient pressure at these points cannot readily be eliminated. 2. The skin about the site for injection may be prepared by an application of tincture of iodin; this is washed off with alcohol just before the needle is inserted. After the injection has been given the remaining iodin should be removed with alcohol, to prevent the occurrence of a dermatitis, and the puncture wound covered with cotton and collodion or with sterile gauze fastened with adhesive straps. 3. The syringe and needle should be sterile. Manufacturers of biologic supplies furnish antitoxin in syringes ready for injection, and these are usually convenient and satisfactory. The needle should be of medium size, and larger than that used for ordinary hypodermic medication. All glass or glass and metal syringes that may be boiled are to be preferred when a syringe is not furnished. Before boiling such a syringe rapidly as to cause the latter to crack. 4. When all is in readiness, the syringe being loaded and the air expelled, the skin is pinched up between the fingers and the needle quickly inserted into the subcutaneous tissues. The injection should be given slowly, and during the. operation, if the patient is a child, an assistant should be on hand to prevent struggling. In the illustration (Fig. 138) the needle is shown connected with the barrel of the syringe by means of a The site of injection is painted with tincture of iodin and covered with sterile gauze fastened with straps of adhesive plaster. Just before the injection is given the iodin is wiped off with a pledget of cotton and alcohol. A fold of skin is pinched up between the thumb and forefinger of the left hand, the needle inserted, and the serum slowly injected. The needle is then quickly withdrawn, and the puncture covered with the gauze and held in place by the adhesive plaster. short piece of rubber tubing. This permits an injection to be given without danger of the needle being broken off if the patient should struggle. Most pain is experienced when the first few drops of fluid are injected; after that the pain is not severe unless the tissues are suddenly distended, as by a quick injection. The amount of serum that may be injected in one area depends upon the age of the patient. Due care should be exercised against injecting too much serum in one area, because of slower absorption and possible necrosis of the skin and subcutaneous tissues. As shown experimentally by Meltzer and Auer, absorption occurs much more quickly when inoculations are given into the muscles than when they are given into the subcutaneous tissues. For this reason antitoxin should be given intramuscularly in severe cases of diphtheria, as the technic is just as simple as that of a subcutaneous injection. Whenever the physician desires more speedy absorption than that which follows a subcutaneous injection, and the intravenous route cannot, for some reason, be adopted, the inoculation should be given in the muscles, preferably those of the buttocks. The technic is the same as that employed for subcutaneous injections, except that the needle is plunged deeply into the muscles. If the most muscular portions are selected for injection, there will be little or no danger of injuring a nerve. If desired, the syringe may be detached after the needle has been inserted to ascertain if a vein has been entered, which would be shown by a flow of blood. If this occurs, the needle should be withdrawn slightly and passed in another direction. The necessity of administering serum intravenously in order to obtain the best results, or any result at all, is becoming more and more apparent. In severe cases of diphtheria the best results are obtained when the antitoxin is given intravenously; in the treatment of tetanus the tetanus antitoxin should be administered intravenously as well as intradurally, and both antistreptococcus and antipneumococcus serums should always be given by the intravenous route. Recent reports indicate that the proper serum treatment of these infections requires large doses given intravenously. Physicians should, therefore, be prepared to give intravenous injections. Since the use of salvarsan in the treatment of syphilis has become so popular many workers have perfected themselves in the technic of intravenous administration, but there is still great hesitancy about giving intravenous injections, although the methods are relatively simple and easily mastered. With nervous patients the injections can be made practically painless by the preliminary infiltration of the skin about the site of puncture with a few drops of a sterile 1 per cent, solution of eucain. as from 5 to 20 c.c., a syringe is employed. 1. It is best to use an all-glass syringe, or at least one with a glass barrel, for the physician can then assure himself that all air has been expelled and that the fluid is free from solid particles. Further than this, a flow of blood into the syringe will indicate that the needle has entered the vein. The syringes furnished by manufacturing firms are not well adapted for making these injections, as the rubber plunger frequently adheres to the glass barrel, so that the injection will be jerky and difficult, and, besides, it may be difficult to determine when the vein has been entered. It is better to empty the contents of these syringes into a large, sterilized, glass-barreled syringe, such as the Record, Luer, and Burroughs-Wellcome syringes, which have a close-fitting but easily working piston, and are attached to the needle by a flange and not by a screw thread. (See Fig. 8.) The needle should be sufficiently large and have a sharp but short beveled edge. A long point may pierce the vein through and through, and permit perivascular bleeding or result in a subcutaneous injection. 2. In young children with fat arms and a weak circulation it is usually necessary to expose a vein at the elbow by making a small incision. In older children and adults a vein may stand out prominently enough to permit the needle to be inserted directly through the skin without making an incision. A firm rubber tourniquet is applied above the elbow; a very simple one is constructed by a single turn around the arm with a piece of ordinary soft-rubber tubing held in place by a hemostat. After the vein has been entered the tourniquet should be quickly removed and this is quickly and deftly accomplished by releasing the hemostat. 3. The skin about the site of injection is cleansed with soap, water, and alcohol, or merely painted with iodin, which is removed with alcohol just before the injection is to be given, in order that the vein may become visible. release the tourniquet. 5. The operator then steadies the skin over a vein — usually the median basilic or median cephalic — with the left thumb and forefinger, and introduces the needle into the vein. A flow of blood into the syringe indicates that the vein has been entered. The tourniquet is then released and the injection slowly given. Or the needle may be detached from the syringe and passed into the vein; when blood appears, the syringe is quickly attached and the injection made. The puncture wound is then sealed with a wisp of sterile cotton and collodion or with gauze and a bandage. The syringe shown in Fig. 139 is well adapted for the intravenous injection of serum, and was devised for the administration of concentrated solutions of salvarsan and neosalvarsan, but any reliable and large glass-barreled syringe may be used. better injected by the gravity method, the simple apparatus shown in Fig. 140 being quite satisfactory for the purpose. This consists merely of a graduated cylinder, which serves as a mea uring funnel, rubber tubing with a pinch cock, and is furnished with a metal tip that fits the needle. The needle should be of proper size, and have a sharp but somewhat short beveled edge. It may be curved, as shown in the illustration, or may be straight. The apparatus shown in Fig. 146 is adapted FIG. 139. — METHOD OF MAKING INTRAVENOUS INJECTION BY MEANS OF A SYRINGE. This syringe was devised for the intravenous administration of a concentrated solution of salvarsan. It is provided with a three-way cock, which permits drawing fluid into the syringe and then injecting it into a vein. This injection may also be given by any glass syringe; the particular advantage of this one is that the operator may inject more than one syringeful of fluid without removing the needle. The same syringe may be used for the intravenous injection of any serum, as diphtheria and tetanus antitoxins. (Apparatus made by B. B. Cassel, Frankfort, Germany.) 3. The injections are best given in a vein at the elbow. The arm about this region should be scrubbed with hot water and soap, followed by alcohol and 1 : 1000 bichlorid of mercury solution, or liberally painted with tincture of iodin. A firm tourniquet is then applied above the elbow; a single firm turn of rubber tubing held by a hemostat is quite satisfactory, as when the vein has been entered the tourniquet should be quickly released with the least movement and disturbance possible, and This method is suitable for the intravenous administration of salvarsan or antistreptococcus serum, etc. The needle has been entered into a prominent vein (indicated by a flow of blood); the tubing has been attached by means of a metal tip which fits the needle easily and snugly; the tourniquet has been loosened and the injection is being given. placed about the arm and shoulder. 4. About 20 c.c. or more of sterile distilled water or normal salt solution are then poured into the cylinder, and the cock opened until all air has been expelled from the tubing. The fluid, serum, or salvarsan is then poured into the cylinder. It is a good practice to filter the fluid through several layers of sterile gauze, especially when salvarsan is being injected, in order to remove any bits of glass or other foreign bodies that may be present. 5. An assistant holds the loaded cylinder and tubing; the operator steadies the skin over a prominent vein and quickly inserts the needle. A flow of blood indicates that the vein has been penetrated. The tubing is then quickly and carefully attached, the tourniquet released by unfastening the hemostat, and the injection given. As a rule, an elevation of the cylinder of two or three feet is sufficient. If swelling occurs about the site of puncture and the patient complains of pain, the injection is entering the subcutaneous tissue; when this occurs, the pinch cock should be closed and the needle removed. It is then necessary to make the injection into another vein or into the same vein at another site. In the treatment of epidemic cerebrospinal meningitis, influenzal meningitis, and tetanus the specific serums are administered subdurally by means of a needle introduced in the lumbar region. Recently subdural injections of salvarsanized serum and weak solutions of salvarsan itself have been advocated in the treatment of cerebrospinal syphilis, tabes dorsalis, and paresis. Every practitioner should be prepared to perform lumbar puncture for the purpose of securing cerebrospinal fluid for making the Wassermann reaction and the bacteriologic, cytologic, and chemical examinations, and the administration of serum is a relatively simple matter when the puncture has been successfully made. The technic of lumbar puncture for the purpose of securing fluid for diagnosis is described on p. 37. But when administering serum, and especially in the treatment of meningitis, the clinical condition of the patient and the danger of sudden collapse render it advisable and necessary that the inoculation be given with the patient lying on his side. Methods. — Two methods are now being employed. The older method consists in injecting the serum by means of a syringe, and the later one is a method whereby the serum is allowed to flow in by gravity. Not infrequently a patient will develop symptoms of collapse during a subdural injection, and these have been ascribed to undue pressure, the injurious action of trikresol or other preservative upon the respiratory centers, too rapid injection, and the introduction of too large a quantity of serum. It is now apparent that in the past too little attention has been paid to the patient while the injection was being made, and serum has usually been administered according to more or less fixed and arbitrary rules, instead of being guided by the clinical condition of the patient. If symptoms of collapse appear during a subdural injection, they may be relieved by allowing the fluid within the canal to flow out again, and this is best accomplished when the inoculation is given by the gravity method. The latter method has been largely worked out and is highly recommended by Sophian, these recommendations being based upon his extensive experience in the recent Texas epidemic of cerebrospinal meningitis. It is also recommended by Flexner and the Hygienic Laboratory, and is undoubtedly the method of choice. Blood-pressure as a Guide in Administering Serum Subdurally. — According to the older and customary method of injecting serum subdurally, fluid is permitted to flow from the needle until from 15 to 20 c.c. have been removed, and an equal quantity of serum is then injected. In severe cases, with thick plastic exudates, only a few cubic centimeters of fluid may be withdrawn, and, indeed, no fluid at all may be secured. To inject arbitrarily a fixed amount of serum under such conditions may be highly dangerous to the patient, on account of increased pressure. On the other hand, when the flow is free, it may be dangerous to permit the canal to drain until intraspinal pressure is reduced to the normal, a fact indicated by the flow of a drop of fluid every three to five seconds. With these considerations in mind, Sophian1 has studied the value of cerebrospinal fluid pressure and blood-pressure as controls- on the amount of fluid that may be safely withdrawn and on the amount of serum that may be injected. During the study and treatment of 500 cases of epidemic cerebrospinal meningitis this last-named observer found that the blood-pressure was a valuable guide. Cerebrospinal fluid pressure was found to be misleading, owing probably to a local distention of the subarachnoid space at the site of injection, which resulted in readings that did not represent the true intracranial pressure. 1. Usually, upon the withdrawal of cerebrospinal fluid, a fall of blood-pressure occurs. With the ordinary blood-pressure in an adult patient — about 110 mm. of mercury — Sophian recommends stopping the flow when there has been a drop in pressure of about 10 mm. of mercury; in children, .about 5 mm. In a few cases there is no change in blood-pressure or even a slight rise; in these instances fluid may be removed until the flow has diminished to the rate of a drop every three to five seconds. 2. With the injection of serum the blood-pressure drops still further. Generally, the decrease in blood-pressure is proportional to the rapidity with which the serum is injected and the amount injected. By the gravity method, under ordinary conditions, at least ten minutes should be consumed in administering 15 c.c. of serum. A total drop of 20 mm. of mercury indicates that sufficient serum has been injected. If it is desired to inject more, as in a severe case of meningitis, close watch should be kept for other symptoms of collapse. 3. Usually, under these conditions, less serum is administered than has been advocated heretofore. It is apparent that the more potent the serum, the less bulk is required — and the bulk alone is an important factor, for a large injection may so injure the patient as to counteract any good that the serum may do. Unfortunately, there is no accurate measure of the curative value of antimeningococcic serum. It is highly desirable that a serum be as potent as possible, and the physician must rely upon the reputation of the firm producing the serum. Efforts are being made to concentrate these serums, much as antitoxin is concentrated, and this is an end very much to be desired. 4. Blood-pressure changes are not constant in the same patient upon different occasions. The pressure should be taken, after each puncture and inoculation, for the administration cannot be guided by observations made on a previous occasion. Collapse during Subdural Inoculation. — Carter has shown, by experiments on dogs, that the first mechanical effects of increased intraspinal pressure were respiratory depression and marked cardiac inhibition. Sophian has found that similar effects may be produced during subdural injections of serum in the treatment of meningitis. The symptoms of collapse, such as stupor, superficial or deep, irregular and slow respiration, and dilatation of the pupils, are foreshadowed by a marked drop in blood-pressure. The pulse may continue good or become slow and irregular. Incontinence of urine and feces may occur. The treatment consists primarily in discontinuing the injection. By lowering the funnel, fluid is allowed to flow from the spinal canal and mix with the serum. If a syringe is being used, it should be detached from the needle or gentle suction made. After a few minutes the symptoms may disappear and the inoculation may be cautiously resumed until the desired amount of serum has been injected; otherwise the needle should be withdrawn. In addition to this procedure atropin and caffein may be administered hypodermically in large doses, and artificial respiration resorted to if necessary. It is well to have these drugs ready for injection before the inoculation is begun, so that no time will be lost when they are needed. Anesthesia for Subdural Inoculation. — There is no doubt but that lumbar puncture and the subdural injection of fluid are painful, the amount of pain depending to some extent upon the degree of meningitis, the method of injection, and the skill of the operator. Severe cases of meningitis that are stuporous or moribund may not evince any evidences of added discomfort; less toxic and robust or nervous patients may, however, suffer considerably and prove difficult subjects for injection. Local anesthesia may be secured by injecting a sterile 1 per cent, solution of eucain in the region where the puncture is to be made. General anesthesia for lumbar puncture in meningitis adds a considerable element of danger, but if it is absolutely necessary, a few whiffs of ether or chloroform may be given while the needle is being inserted. In giving subdural injections in tetanus a general anesthetic is necessary. of it and keep very quiet. Gravity Method. — The apparatus required is very simple, and consists essentially of a proper needle and from 12 to 16 inches of softrubber tubing attached to a container or funnel for serum and furnished with a metal tip by which it is quickly and readily attached to the needle. Several manufacturers of biologic supplies are marketing antimeningococcic serum in a special container, fashioned after that devised by Sophian and Alexander, with the needle and tubing adapted for the administration of the serum by the gravity method. Such an apparatus is shown in Fig. 141. The physician may, however, prepare an equally efficient apparatus, similar to that shown in Fig. 14 i, which consists of the glass barrel of a 20 c.c. syringe attached to 16 inches of soft-rubber tubing fitted with a metal tip that holds the needle firmly and snugly. The whole is sterilized by boiling, and any quantity of serum may be administered with it. The apparatus is adapted for the administration of antimeningococcic serum, tetanus antitoxin, influenza serum, salvarsanized serum, or any other fluid, and has given uniform satisfaction. The needle should be from 10 to 11 cm. in length, with a wide, rather than a narrow, lumen — about 1.5 to 2 mm. This is important in administering serum to a case of meningitis, in which a needle with a narrow lumen may become plugged with exudate. The needle should be fitted with a trocar. The tip should have a short bevel with a sharp edge. Technic. — 1. The serum should be warmed to body temperature by wrapping the sealed container of serum in towels wrung out of water comfortably hot for the hands (about 42° C.). Cold serum possibly increases the pain caused by the injection, although the pressure upon ized and ready for use. Two sterile graduated centrifuge tubes should be on hand for collecting and measuring the spinal fluid. The apparatus should be assembled and ready for injection, so that at the appointed time the tubing may be attached to the needle and the inoculation given. 3. The patient should be placed on the left side, on the edge of a bed or table. An assistant places the patient in such a manner as to arch The line marks the crest of the ilium, and indicates the third lumbar interspace. The needle has been inserted and cerebrospinal fluid withdrawn. Antiminingococcus serum is being administered. The barrel of a 20 c.c. Record syringe is serving as a funnel, and is attached to the needle by means of 18 inches of soft-rubber tubing furnished with a metal tip. The needle, as shown, is reduced to about four times its actual size. This method may be used for making the subdural injection of tetanus antitoxin and salvarsanized serum. readings during the operation. 4. Towels wet with bichlorid are arranged about the site of inoculation. It is well for the operator to locate the site of injection by palpating the spinous processes and selecting the widest interspace, which is usually on a level with the crests of the ilia if the back is well arched. The skin is then cleansed with soap, water, and alcohol, and bichlorid solution or a coat of iodin applied. Some degree of local anesthesia may be secured by injecting a small amount of a sterile 1 per cent, solution of eucain. This is advisable in nervous adults. 5. The operator must then choose between the median or lateral route of puncture. The median is the easier, and should always be adopted by the inexperienced operator. Wash off the iodin with a pledget of cotton soaked in alcohol. Locate the chosen interspinous space, pressing well between the spines with the left thumb or index-finger, and holding the finger in place pass the needle perpendicularly in the median line between the spines, or, better still, at an angle of 45 degrees upward and inward. If an obstruction is felt, withdraw the needle slightly and pass it in a different direction until it imparts a sense of " giving way," which indicates that the subarachnoid space has been reached. Quincke has estimated the depth of lumbar puncture in adults to be usually from 4 to 6 cm. ; in large muscular men it is from 7 to 8 cm., and in fat persons, about 10 cm. The needle should be inserted slowly and deliberately, rather than quickly, as puncture of a bone is likely to be followed by a dull, aching pain, and, indeed, the point of the needle may be bent or broken. The fluid may fail to flow or flow very slowly. This may be due to the presence of a thick exudate, impalement of a nerve filament, or adhesions arising from a previous puncture. The needle may be turned gently or the trocar inserted to remove an obstruction, after which the flow usually starts; if it does not do so, the needle may be withdrawn slightly or cautiously inserted a little further. 6. Fluid is collected in the centrifuge tubes while blood-pressure readings are being made. When the pressure drops 10 mm., or if the flow is about a drop every three or five seconds, the tubing is connected and the serum injected very slowly. As a general rule, as much fluid should be withdrawn as can be done with safety, and the maximum dose of serum given. When the flow is scanty, a larger dose of serum may be given than counterbalances the fluid removed, the injection being guided by the blood-pressure. When the total drop reaches 20 mm. of mercury, the injection should be discontinued, or if continued, the patient should be watched closely for other symptoms of collapse. 7. After the injection has been completed the needle is quickly withdrawn and the wound covered with sterile gauze held in place by adhesive straps. All iodin should be washed off with alcohol to avoid irritation or an actual dermatitis. Manufacturing concerns market their products in syringes all ready for injection. When injecting tetanus antitoxin, it is necessary to empty the syringe into another sterile syringe, as shown in the accompanying illustration (Fig. 143), which will fit an appropriate needle. Since the plunger of the purchased syringe oftentimes adheres to the barrel and renders the injection jerky and difficult, I frequently transfer the serum to a sterile, all-glass syringe which I know will work smoothly and satisfactorily. FIG. 143. — INTRASPINAL INJECTION BY MEANS OF A SYRINGE. The line indicates the crest of the ilium, and usually passes between the third and fourth lumbar vertebrae, which is the proper point for inserting the needle. The site of injection has been painted with tincture of iodin after cleansing with soap, hot water, and alcohol. An assistant holds the patient to prevent sudden jerking and possible accident. 2. Lumbar puncture is performed as for the gravity method while blood-pressure observations are being made. When sufficient fluid has been removed, the loaded syringe is attached to the needle and the injection slowly given. The physician is frequently tempted to inject the serum and complete the operation quickly, but it is better to inject it in amounts of 0.5 to 1 c.c. every half to one minute, being guided by the blood-pressure readings and general condition of the patient. If the pressure falls below 20 mm. of mercury or other symptoms of col- lapse appear, the fluid may be drained from the canal by gentle suction with the piston. This is usually impossible when the manufacturers' syringe is used. Otherwise the syringe is detached and the fluid collected in tubes until the patient's condition improves and the injection is resumed or the needle removed. At times the patient is so restless that this slow method is not feasible. In such instances the physician should make the injection as slowly as possible, endeavoring to put into the canal as much serum as fluid was removed or at least a reasonable amount. of this infection constitute one of the triumphs of modern medicine. Twenty years ago diphtheria was one of the most dreaded of diseases, accompanied ordinarily by a mortality of at least 30 per cent., while the loss of life from the laryngeal form of the disease, particularly after tracheotomy, was simply appalling. Shortly after Roux and Yersin (1888) had demonstrated that the symptoms of diphtheria were due largely to a soluble poison or toxin secreted by the bacilli, Ferran, and later Fraenkel and Brieger (1890), undertook experiments in active immunization against diphtheria. About the same time von Behring discovered the antitoxin, and in a series of extensive researches with Wernicke he established experimentally its prophylactic and therapeutic value in diphtheria. The first attempt to apply this discovery to the cure of this infection of the human being was made in von Bergmann's clinic (1891). The results, while encouraging, were not altogether satisfactory, owing largely to the fact that the serums were weak and the doses given too small. The discovery, however, resulted in creating an extraordinary stimulus to researches in immunity, and during the following two years more powerful serums were prepared, so that in 1896 a marked drop in the mortality of diphtheria was apparent in those places where the antitoxin was being used. Since then diphtheria antitoxin has been the means of saving countless thousands of lives, and the treatment of diphtheria, instead of being a reproach to medicine, has become the model of what the scientific treatment of an infectious disease ought to be. Statistics and the individual experiences of those especially engaged in the treatment of diphtheria show that when the antitoxin is used on the first day of the SERUM TREATMENT OF DIPHTHERIA 755 disease, practically no mortality occurs. Parents and guardians should be taught this fact, and cautioned to seek medical advice promptly whenever a child complains of sore throat. While the use of diphtheria antitoxin is still decried and opposed by a few members of the medical profession,— and this is not to be wondered at when it is remembered that cowpox vaccination still has its opponents, — it is at least to be hoped that no physician will deprive a patient suffering from diphtheria of the benefits to be derived from the antitoxin treatment. In the absence of special contraindications the refusal or neglect to use antitoxin in the treatment of diphtheria would, in the opinion of most physicians, constitute an act of criminal negligence and malpractice. Preparation of Diphtheria Antitoxin. — The methods of preparing and standardizing diphtheria antitoxin are given in Chapter XIV. Briefly, these consist in the preparation of a strong toxin by cultivating a virulent strain of the bacillus in a suitable broth for ten days or two weeks; the culture is then passed through a porcelain filter, which retains the bacilli, the filtrate being a strong solution of toxin. This is standardized by the physiologic test of determining its action upon guineapigs, the minimal lethal dose (M. L. D.) or toxin unit being the amount of toxin that will cause the death of a 250-gram guinea-pig in four days. Strong and healthy horses that have been proved by the tuberculin and mallein tests to be free from tubercle or glanders, are then continuously immunized by a series of injections of the toxin. The first doses are guarded by the simultaneous injection of antitoxin, but after from four to six months the animals are able to tolerate enormous quantities of pure toxin. The horses are then bled aseptically from a jugular vein, and the separated blood-serum, preserved with a small percentage of an antiseptic, becomes the antitoxin of commerce. Many manufacturing concerns market a concentrated diphtheria antitoxin prepared by precipitating the globulin fraction of the raw serum with ammonium sulphate, and redissolving it in a minimal quantity of salt solution. The globulins carry with them most of the antitoxin, and in this manner a serum may be concentrated so that a large number of units are contained in a small bulk of fluid, obviously a most desirable feature in the treatment of diphtheria. Further than this, it has been observed that these concentrated antitoxins are much less likely to produce serum sickness, a train of symptoms due to substances present alike in normal and in antitoxic horse serum, and independent of the antitoxin. The antitoxic unit is the smallest amount of serum that will just neutralize 100 times the minimal lethal dose of toxin for a 250-gram guinea-pig. The adoption of such a standard enables us to attain some accuracy in dosage. Before its introduction antitoxin was given in so many cubic centimeters, just as antimeningococcus and antistreptococcus serums are given today, but since some horses produce more potent serums than others, the results were quite irregular. At the present time an antitoxic serum is marketed according to the number of units it contains, irrespective of the actual amount of serum, the constant endeavor being to produce as potent a product as possible. Since antitoxin gradually deteriorates with time, physicians should carefully observe the date printed upon each package of antitoxin, which is the time limit calculated by the manufacturers beyond which they do not guarantee that the full antitoxic strength is maintained. Nature of Diphtheria. — In the great majority of cases diphtheria is a local infection of some portion of the upper respiratory tract. The bacilli are usually inhaled, find lodgment upon a mucous membrane, and secrete a toxin that produces necrosis of the cells of the mucosa and effectually resists phagocytosis of the bacilli. From this area of infection, which now becomes a prolific source of toxin production, the toxin or poison is absorbed by the body-fluids, and the resulting toxemia is chiefly responsible for most of the symptoms of the disease. Other microorganisms, such as staphylococci, pneumococci, and streptococci, which may be unable to infect a healthy mucous membrane, readily multiply in the necrotic tissue and add to the severity of the local lesion, the lymphadenitis, and the toxemia. Rarely the diphtheria bacilli gain access to the blood-stream. The severity and danger of diphtheria are dependent primarily upon the strength and amount of toxin produced by the bacilli, and secondarily upon the size and location of the primary lesion and the amount of antitoxin present in the patient's blood. A lesion in the larynx is far more dangerous than one of equal size on a tonsil, because in the former the edema and necrotic exudate obstruct the trachea and may produce death by suffocation. On the other hand, the size of the local lesion alone is not an indication of the severity of the infection, because virulent bacilli in a small patch may produce more toxin than less virulent ones in a larger area, and the degree of local tissue necrosis is not an absolute indication of the toxicity of the soluble poison. Other things being equal, the patient who has most antitoxin, either naturally or acquired as the result of a previous injection with antitoxin or of an attack of diphtheria, will present least evidences of toxemia, although the bacilli causing the infection may be most virulent. For example, the highly virulent strain of diphtheria bacillus used extensively in the past eighteen years in the production of antitoxin was isolated by Park and Williams from the throat of a patient presenting no clinical symptoms other than redness of the fauces and slight toxemia. The primary lesion of diphtheria is usually located in the throat (tonsils, uvula, larynx), and frequently in the nose; more rarely the ears, conjunctiva, vulva, prepuce, and wounds are the seats of primary infection. Treatment of Diphtheria. — If we were always certain of seeing our patients on the first day of their illness, and if the disease could always be diagnosed in this stage, the treatment of diphtheria would resolve itself into an immediate dose of antitoxin and rest in bed for two or three weeks. But patients frequently come under treatment comparatively late in the disease, or the true nature of the condition may not be fully diagnosed at first and treatment thus be delayed. Diphtheria is, therefore, still to be regarded as a dangerous infection, and while the proper use of antitoxin constitutes the most important part of the treatment, local applications, general constitutional measures, and the management of the various conditions that may complicate the disease are all to be considered. Here we will discuss only the serum treatment of the disease. disappear. Action of Diphtheria Antitoxin. — Diphtheria antitoxin best fulfils these requirements. In fact, there are no substitutes. In former days the powerful and irritant caustics and germicides that were freely applied to the throat, instead of limiting the disease and destroying the bacilli, probably actually encouraged its extension by excoriating and depressing the resistance of the surrounding mucous membranes. 1. The chief action of antitoxin is just what its name implies, namely, a substance that neutralizes the toxin. This is regarded as a chemical reaction analogous to the neutralization of an acid by an alkali. When the antitoxin molecule has united with the toxin molecule, it is believed that the toxin is neutralized and that both are rendered inert. As the result of experimental studies, however, we know that this union is not always a firm one, and it is possible for the toxin to become dissociated and attack body-cells or other molecules of antitoxin, thus explaining in part the necessity for giving quite large doses of antitoxin — doses that are out of all proportion to what we would expect to be necessary, when considered weight for weight between guinea-pig and man, to effect complete neutralization of the toxin. It is reasonable to presume, and may be accepted as true, that a stronger affinity exists between diphtheria toxin and antitoxin than between body-cells and toxin. Just as the union between this toxin and its antitoxin is somewhat unstable, so, in like manner, it is probable that the union of toxin and body-cells is not so firm but that it may, during an early stage, -be dissociated to some extent by the more attractive antitoxin. This factor is to be borne in mind in the treatment of diphtheria, and is an additional argument for the administration of large doses of the serum. 2. Antitoxin pure and simple does not, however, constitute the only factor of value in antidiphtheric serum. While the pure antitoxin neutralizes the toxin, it has no injurious action on the bacilli themselves, and, indeed, it is said that the bacilli may live and multiply in the presence of large amounts of antitoxin. How, then, are we to explain the gradual disappearance of the membranous exudate and the bacilli at the local site of infection? It has been shown experimentally that virulent diphtheria bacilli resist phagocytosis. This condition is probably due to an actual leukotoxic action of the diphtheria toxin, aided by an aggressin-like action of the toxin which neutralizes opsonin, and in this manner prevents phagocytic activity. I in common with other observers, have shown that the antiserum as ordinarily produced neutralizes the antiphagocytic action of diphtheria bacilli, and enables the polynuclear leukocytes to ingest them readily.1 Whether this is brought about through neutralization of the toxin by antitoxin, or is due to the presence of an immune opsonin (bacteriotropin) that lowers the resistance of the bacilli, or to the presence of an anti-aggressin that neutralizes the intrinsic defensive mechanism of the bacilli and thus favors phagocytosis, I am unable to state, but probably all three factors are operative. 3. As ordinarily prepared, diphtheria antitoxin possesses little or no bacteriolytic activity. I have found, however, that antitoxin will fix complement with an antigen of diphtheria bacilli,2 indicating, therefore, the presence of bacteriolytic amboceptors. Serums produced by immunizing horses with unfiltered cultures of diphtheria bacilli instead of with the filtered toxin alone have been advocated for the general and the local treatment, in the hope of securing lysis of the infecting bacilli. Certainly it would appear wise to raise the bacteriotropic and bacteriolytic content of an immune serum by injecting the horses occasionally with unfiltered cultures, for it is highly probable that the action of the antiserum depends not only upon an antitoxin, but also, to some extent at least, upon a bacteriotropin and possibly a bacteriolysin. ministered by subcutaneous injection into the tissues of the back, abdomen, or buttocks. Experimental studies have tended to show that complete absorption does not occur until forty-eight hours after, although it is common clinical experience to observe improvement take place during the first twenty-four hours after injection. As will be emphasized later, it is highly desirable and necessary "to get antitoxin into the circulation as soon as possible after infection has occurred. Usually this is best accomplished by giving antitoxin to every patient even suspected of being diphtheric, and making the diagnosis afterward; the next best method is to administer the antitoxin in such manner as to favor quick absorption. For this reason intramuscular and intravenous injection should be resorted to in all severe cases. As pointed out in Chapter XXXI, the Schick reaction in diphtheria has indicated that diphtheria toxin may be dissociated from tissue-cells by large doses of antitoxin. Park and his associates have shown experimentally by this reaction that 20,000 units of antitoxin given subcutaneously were necessary to yield an effect equal to 1000 units given intravenously. Intramuscular injections into the muscles of the buttocks are just as readily given as subcutaneous injections, and are probably no more painful to the average patient. It insures quicker absorption, and may, indeed, be adopted as a routine practice. Intravenous injections are far more difficult, especially in children with fat arms and feeble circulations. An anesthetic or ten minutes1 struggling may do the patient harm, and unless the injection can be given with little disturbance and danger, the serum should be given by intramuscular injection. Not infrequently, however, an intravenous injection yields splendid results in severe and apparently hopeless cases, and in older children and adults this route of administration should be considered. The syringe method is well adapted for the intravenous injection of antitoxin, as the bulk method of serum is usually small, especially if a concentrated antitoxin is being used. The technic of these injections has previously been described. Antitoxin has also been given by the mouth and even by rectal injection. The presence of a preservative, usually phenol, renders the oral administration objectionable. While a therapeutic effect may be secured after large doses have been swallowed, there are very few occasions when this should be the method of choice. be fatal to wait for the result of a culture, except perhaps in the case of the mildest of infections. In fact, the necessity for early administration of antitoxin cannot be overestimated. When once suspicion is aroused, antitoxin should be given at once and the diagnosis may follow. A few hours may make an enormous difference in the prognosis of any case, and while a dose of 2000 units of antitoxin may prove of the utmost value in checking diphtheria, it will do no harm whatever in case the disease is not present. It is true that a physician will naturally hesitate to administer antitoxin unnecessarily; nevertheless, diphtheria is frequently a difficult disease to diagnose clinically, and is quite likely to be mistaken for tonsillitis. For this reason many physicians prefer to wait for the result of a culture, and this is proper, provided that the patient, especially in the case of a child, is given the benefit of the doubt by receiving 2000 units of antitoxin. It is to be emphasized that a single negative culture does not exclude diphtheria. As ordinarily made, about 20 per cent, of primary cultures from genuine cases of diphtheria fail to show the presence of bacilli, whereas subsequent cultures will show them to be present in large numbers. A primary negative culture is most likely to be obtained from a patient having a heavy exudate, as the physician may rub lightly over the membrane, culturing the microorganisms of secondary infection and overlooking the diphtheria bacilli in the depths of the membrane adjacent to the diseased mucous membrane. To wait another twentyfour hours for a second culture still further reduces the patient's chances for recovery. In the vast majority of instances, therefore, antitoxin should be given at once and repeated as often as is necessary until the correct diagnosis is established, and not one but at least two successive negative cultures should be obtained before diphtheria is to be excluded with any reasonable degree of safety. The following table, compiled from the annual reports of the Philadelphia Hospital for Contagious Diseases, shows the decided influence of early treatment upon the mortality of diphtheria. This table comprises cases of diphtheria alone, and does not include cases complicated by other diseases, such as scarlet fever and measles. It is worthy of special notice that of 741 cases treated with antitoxin on the first day of the disease, not one died. Ker,1 in an exceptionally rich experience, has never seen a fatal result occur in a case that developed in a hospital and in which antitoxin was administered on the first day of the disease. 1 Infectious Diseases, 1909, Oxford Med. Press. It is generally believed that the paralyses of diphtheria are due to a toxone, and not to the true toxin. Ehrlich believes toxone to represent a late secretory product of the diphtheria bacillus, whereas others regard it as a modified toxin. It is certainly apparent, however, that the bacilli should be gotten rid of as soon as possible, so as to eliminate the possibility of toxone production. This is best accomplished by the early use of large doses of antitoxin, aided possibly by judicious local treatment. Dosage of Diphtheria Antitoxin. — While it is now generally agreed that the doses of from 100 to 200 units, such as were commonly given during the early years of antitoxin therapy, were far too small, there is still some difference of opinion regarding the proper doses to employ. Since the severity of the disease varies so markedly, no hard and fast rules can be given. The physician who has a clear idea of the nature of diphtheria and of the action of antitoxin, and knows what to expect of the latter in the treatment of the disease, should have no difficulty in properly treating a case of diphtheria. It is to be emphasized, however, that while antitoxin constitutes the most important part of the treatment of diphtheria, it is not usually the whole treatment. Absolute rest in bed, a generous diet, combined with the use of tonics and local applications, are all part of the treatment. Special treatment of the laryngeal form of the disease and the treatment of complications are matters of considerable importance that influence the prognosis in a given case. I may mention, in passing, the value of destruction and excretion. In administering antitoxin the physician must be guided by the clinical condition of the patient, as we have as yet no practical laboratory method for estimating the degree of the toxemia. Treatment may be regarded as satisfactory when — severe infections it may be normal or subnormal throughout. So long as the exudate shows no signs of loosening and disappearing, but tends to spread, and so long as the general condition remains unimproved or grows worse, large amounts of antitoxin should be given. No case should be regarded as hopeless until death supervenes. Every case of diphtheria is to be treated individually, rather than by any set rule. The amount of antitoxin given in the initial dose, and in subsequent doses as well, is dependent on the following factors : 4. The age of the patient. 1. The Situation and Extent of the Lesion. — In ordinary tonsillar diphtheria in which there is a small patch on one tonsil and which is first seen on the second day of the disease, the initial dose should be at least 5000 units. When the exudate involves the pillars of the fauces, the uvula, the posterior pharyngeal wall, or is well forward on the palate, this dose should be doubled, and 10,000 units be given. Cases that present laryngeal symptoms in addition to faucial lesions should never receive less than 12,000 units. In well-marked laryngeal diphtheria with dyspnea and partial suffocation at least 20,000 units should be given, preferably by intramuscular or intravenous injection. In nasal diphtheria a distinction must be made between those cases that exhibit merely a dirty, chronic discharge containing bacilli, in which 2000 units may suffice, and those that present an actual membrane accompanied by well-marked toxic symptoms, when a large amount of serum — at least 10,000 units — should be given. Owing to the ready All these doses must be regarded merely as suggestions for the initial dose in cases seen on about the second day of the disease. Physicians with extensive hospital experience, for example, Woody and McCullom, generally favor large doses, and while in private practice the question of expense and economy may be a factor, the physician will be wise to err on the side of safety and give a little too much serum rather than too little, especially in the first dose, when so much depends upon how soon antitoxin is introduced into the body-fluids. 2. The general condition of the patient, or the effect which the toxemia will have on the patient, is highly important in estimating the dosage of antitoxin. A patient who is pale, drowsy, prostrated, and has a weak and irregular pulse; who has large masses of glands around the neck, or who has marked albuminuria, will require a much larger dose than one who presents none of these signs. Two persons of about the same age and suffering from the same lesions may show very different degrees of toxemia. In the severe cases we must administer the maximum dose and repeat it at suitable intervals until an effect is produced. 3. The day of illness on which the patient comes under observation is important in deciding the initial dose of antitoxin. For corresponding tonsillar lesions a dose of 2000 units on the first day may do more good than 5000 units given on the fourth day. Ker gives second-day cases of purely tonsillar diphtheria 3000 units, and adds an additional 1000 on the following day. 4. If the age of the patient exerts any influence at all on dosage, it indicates that more antitoxin should be 'given to children than to adults with corresponding lesions, as the disease is more fatal in children. So far as infants are concerned, Ker seldom gives more than 4000 units at a single dose, which should be an adequate amount when we consider the small size of the patient. Children over one year of age may be given from 5000 to 10,000 or more units, depending upon the location of the lesion and the degree of toxemia. Repeating the Dose. — Whether or not subsequent doses of antitoxin will be required is dependent upon the circumstances of the individual case. In ordinary cases if on the day after treatment is commenced there is no diminution in the amount of membrane visible and the general symptoms have not improved, the dose should be repeated. If the membrane has spread and the toxemia is worse, the second dose should be larger than the first. In septic cases the second dose may be given in from six to ten hours after the first. If the symptoms are less urgent, the interval may be extended to twelve, but should never exceed twentyfour hours. As to the total amount of serum to be administered, continued injections at relatively short intervals are required until improvement has taken place. So long as membrane is present and the patient is toxic it is probably worth while to push the treatment unless these show a tendency to clear away. Time must be allowed for absorption to take place, and the serum should not be pushed so far as to be wasted, and, quite possibly, excreted unchanged. The remedy is expensive, especially in private practice, and it is obviously desirable to have due regard for economy. While, as previously mentioned, physicians of such wide experience as McCullom, of Boston, and Woody, of Philadelphia, frequently give 200,000 or more units in severe cases of diphtheria, others, e. g., Ker, of Edinburgh, have never given more than 64,000 units to a single patient, and, indeed, several of my colleagues of wide experience claim that they have secured excellent results in severe infections with doses that seldom exceeded 10,000 units. Treatment of Relapses. — Occasionally, after a patient has recovered from an attack of diphtheria the infection recurs after several weeks. It is in such cases that the physician hesitates to administer antitoxin, on account of the discomforts occasioned by serum sickness. It is true that serum sickness is more likely to follow in these than in primary cases, and the very profuse and itchy eruption, joint pains, and fever do indeed render the patient quite uncomfortable. Since a relapse is usually, although not always, comparatively mild, the serum may be dispensed with if there is no involvement of the larynx and if there is not much evidence of toxemia; otherwise full doses of antitoxin should be given without hesitation. The subcutaneous injection of 0.5 c.c. of the serum two or three hours before the main dose is given may possibly produce a condition of anti-anaphylaxis and ward off the more dangerous symptoms. If respiratory difficulties should follow, a reinjection of serum, atropin, and caff ein should be administered hypodermically. ness, occurring at varying times following the administration of antitoxin. This condition has been shown to be due to certain constituents of horse serum other than the antitoxic antibodies. It is noteworthy that the serum of one horse may cause more serum sickness than that of another; in general, concentrated antitoxins produce fewer cases than do raw serum. This condition is characterized by the development of a rash (urticarial, multiform, or scarlatiniform), mild fever, joint pains, and possibly adenitis. The scarlatiniform rash may be extremely difficult to differentiate from that of true scarlatina, especially in the wards of a diphtheria hospital, where outbreaks of scarlet fever are not uncommon. This subject has been considered in greater detail in Chapter XXVIII on Anaphylaxis. It may be stated here that while the patient is decidedly uncomfortable, and even quite sick, for several days, serum sickness is not a dangerous condition; the treatment is largely symptomatic and palliative. Value of Diphtheria Antitoxin. — At the present day it seems hardly necessary to introduce elaborate statistics to prove the value of antitoxin in the prophylaxis and treatment of diphtheria. 1. It is generally admitted that most of the reduction in the mortality of diphtheria cannot be attributed solely to the use of antitoxin, for unquestionably bacteriologic diagnosis has permitted the inclusion, in our statistics, of a certain number of cases that, twenty years ago, would not have been classed as diphtheria. Generally speaking, however, the mortality of diphtheria, considering all types of infection coming under observation at varying intervals after the disease has developed, is at least five times less under antitoxin treatment than when it is treated without antitoxin. This proportion is true, whether we compare the general mortality before 1896 with the present rate, or whether we take a large city and compare the mortality under both forms of treatment for a single or for several years. For example, in Philadelphia the mortality rates per 100,000 of population for the five years preceding the use of antitoxin were as follows: In Philadelphia, during the years 1909-10 and 1911, the average mortality of diphtheria treated with antitoxin in the Philadelphia Hospital for Contagious Diseases was 9.9 per cent., and in the private practice of physicians, 13.07 per cent. In contrast to these figures is the mortality of 40.34 per cent, in the private practice of those physicians (fortunately few) who refused to give antitoxin or in those families opposed to its use. From Table 28 it will be seen that the average mortality in 13,106 cases of pure diphtheria treated with antitoxin in the Philadelphia Hospital for Contagious Diseases during the past ten years was only 7.96 per cent. As stated elsewhere, when this is compared with the average mortality of about 41 per cent, when no antitoxin was used, it is not difficult to appreciate the therapeutic value of the remedy. 2. As was previously stated, it is also worthy of note that there is practically no mortality in diphtheria cases receiving antitoxin on the first day of illness. During nine consecutive years (1904-1913), covering the treatment of 741 such cases in the Philadelphia Hospital for Contagious Diseases, not a single death occurred. During 1913 two of the 51 firstday cases died. It will also be noted from Table 28 that the patient's chance for recovery grows steadily less with each day that the administration of serum is delayed, and this should be evidence enough to convince any right-minded person that we possess in antitoxin a remarkable remedy for the treatment of diphtheria. 3. The influence of antitoxin is also noted in the mortality of laryngeal diphtheria. While the mortality in this condition is still high, owing to the frequency and dangers of bronchopneumonia and the necessity for operative measures, it has been reduced at least one-half since antitoxin came into general use. Prior to 1896 the mortality was at least 70 per cent.; since then it has been reduced to 35 per cent, or less. As shown in the following table, of 1207 cases treated in the Philadelphia Hospital for Contagious Diseases, the average mortality was 35.6 per cent. Formerly when a child contracted diphtheria the parents were warned of the likelihood and danger of the infection involving the larynx and trachea; nowadays this possibility is quite remote. 4. Finally the claim of the opponents of the serum therapy of diphtheria that antitoxin increases the percentage of paralyses is without foundation. While it is true that this percentage is somewhat higher than was noted in former years, this increase is to be explained by the fact that antitoxin saves a larger number of severe cases long enough for them to manifest paralyses, and, second, by the greater attention that has recently been directed to its milder forms. Since diphtheric paralysis is regarded as caused by toxone or a later secondary toxic product of the bacilli, the indications are to rid the patient of the bacilli as quickly as possible, and this is best and most surely accomplished by the proper administration of antitoxin. PROPHYLACTIC IMMUNIZATION AGAINST DIPHTHERIA The subcutaneous administration of relatively small doses of antitoxin will usually confer a passive immunity against diphtheria lasting from two to four weeks. The object is to introduce antibodies (antitoxin and opsonin) into the body-fluids in order that they may neutralize the toxin as rapidly as it is produced, aid in the destruction of the bacilli, and thus protect the access to the tissues. The doses advised are relatively small, and the injection does not usually produce any discomfort other than soreness about the site of inoculation. For infants under one year of age 500 units suffice; for older children and adults from 1000 to 1500 units should be given. The duration of this passive immunity is relatively short, owing to the fact that the antitoxin is eliminated rapidly, as it is part and parcel of a foreign serum that tends to be excreted or destroyed soon after its introduction into the body. It will endure, however, for at least two weeks, and frequently longer. Since the incubation period of diphtheria is only a matter of a few days, this suffices, in the majority of instances, to protect the individual. The indications are to immunize all persons who have come in intimate contact with a case of diphtheria. If time permits the Schick test should be conducted, as only those persons yielding positive reactions require the antitoxin (see page 229). It is especially valuable in families and small communities, such as go to make up hospital wards and asylums. The physician who is attending a case of diphtheria in a private home should urge immunization upon all members of the household. The immediate results ?,re usually good. The main disadvantage is the short duration of the immunity, so that no matter how faithfully it is carried out, persons do not remain immune for long periods of time, and accordingly the total morbidity of the disease is not influenced to any extent. In homes from which the case of diphtheria is promptly removed to a special contagious hospital and in which the remaining members are promptly immunized the percentage of secondary cases is practically nil. Of 6772 patients who were removed to the Philadelphia Hospital for Contagious Diseases, the remaining members of the family not being immunized, secondary cases developed in 164 persons, or in 2.4 per cent. Of 4063 cases of diphtheria treated at home with antitoxin, the other members of the family not being immunized, secondary cases developed in 219 persons, or in 5.3 per cent. Of 639 diphtheric patients treated at home who did not receive antitoxin and where immunization was not practised, secondary cases developed in 151 persons, or 23.6 per cent. These figures, compiled by Dr. A. A. Cairns, chief medical inspector of Philadelphia, and taken from the annual reports of the Philadelphia Bureau of Health for the years of 1909, 1910, and 1911, show that the best results are obtained when the diphtheric patient is promptly removed to a special hospital and the remaining members of the household are immunized. Even when the patient is removed promptly there is some danger of other persons having been infected, and immunization should, therefore, always be promptly practised. When the patient is treated at home, other members of the household, even if immunized, are liable to develop the infection, probably owing to the fact that the patient harbors virulent bacilli for varying periods of time after the passive immunity in other persons has passed away and the quarantine is broken. Certainly in those homes where antitoxin is not used either for therapeutic or for prophylactic purposes, the percentage of secondary infections is so high as to leave no doubt as to the value of antitoxin. In this connection I may mention the desirability of using an antitoxin prepared by immunization of cattle for the general purpose of prophylaxis, and especially for the treatment of those persons who are hypersensitive to horse serum. In these cases horse antitoxin could be used later if a person contracted diphtheria without danger of anaphylaxis. Behring's Method of Immunization against Diphtheria. — Owing to the fact that the antibodies produced through the activities of our own body-cells (active immunization) persist for longer periods of time than those that are introduced passively (passive immunization), Behring and his assistants have been working upon a method of active immunization in diphtheria whereby our own body-cells are to be stimulated to produce our own antitoxin in sufficient amounts to protect us against the disease. It has long been known that more or less balanced mixtures of this kind produce immunity in animals, and in 1907 Theobald Smith1 suggested that it might be possible to employ this method for the purpose of producing immunity in man. Subsequently Smith2 studied the effects of injections of neutral mixtures in guinea-pigs and horses, and again pointed out the applicability of the method to human beings Active immunization in diphtheria could probably be accomplished by the administration of minute and increasing doses of toxin, but there would be some danger of producing an 'acute toxemia or paralysis, and the process may require so much time as to be useless in the presence of epidemics. Convention on International Medicine in 1913, is based upon the principle that the union of toxin and antitoxin is not stable, and when a neutral mixture of the two is injected into animals, sufficient toxin becomes dissociated to unite with body cells and stimulate the production of antitoxin. The mixture of toxin and antitoxin is known as T.-A., and several strengths are being used; of these, the first dose possesses the lowest toxicity and is overneutralized by mixing 1 unit of antitoxin with 50 per cent, of the L+ dose of toxin; the second dose may be about neutral or 65 per cent, of the L+ toxin with 1 unit of antitoxin; the third dose is usually slightly toxic for the guinea-pig afid is prepared with 80 per cent, of the L+ dose of toxin with 1 unit of antioxin. I generally prepare these solutions in such proportions that the proper doses are contained in 1 c.c. The following is an example of the preparation of 100 doses of each of the three mixtures with a toxin having an L-f- dose of 0.2 c.c.: 100 doses. To each of these is added an amount of antitoxin serum equal to 100 units and sufficient sterile salt solution containing 0.25 per cent, tricresol to make the total volume 100 c.c. After standing several hours the toxicity of each mixture is tested by subcutaneous injections into 250-gram guinea-pigs. cutaneously at intervals of ten days. The method has now been used for immunizing a large number of persons, chiefly under the supervision of von Behring and his assistants.1 The natural antitoxin content of the blood is determined, usually by the intracutaneous method on the guinea-pig, before and after immunization, and has shown uniformly a considerable increase, which persists over many months. Local and general reactions have been observed, especially in older children and adults with doses intended for the new-born; this fact is explained on the assumption of a specific sensitization in consequence 1 See Semaine Me"dicale, 1913, xxxiii, No. 18; Berl. klin. Wochenschr., 1914, hx, 917; ibid., 1914, lix, 917; Therap. Monatssch., 1913, xxvii, No. 11; Deutsch. med. Wchnschr., 1913, xxx, 460; ibid., 1913, xxix, 977; ibid., 1913, xxxix, 1977; ibid., 1913, xxxix, 2500; ibid., 1914, xl, 13; ibid., 1914, xl, 582. of the previous introduction of diphtheria bacilli (carriers), which latter render the individuals hypersensitive to the T.-A. Reactions that are regarded as non-specific have been observed in tuberculous and scrofulous persons, and for the present von Behring prefers that the use of the prophylactic in such persons, as well as in atrophic infants and infants less than nine months old, be regarded as contraindicated. The fear expressed by some that the prophylactic is contraindicated in those persons who harbor diphtheria bacilli for fear of producing the disease during temporary depression of the defensive mechanism has been finally dissipated as the result of practical experience. Not one of the numerous bacillus-carriers that have been injected with T.-A. have sickened with diphtheria. Whether or not the active immunization with T.-A. will help them to get rid of the bacilli is still an open question. The subcutaneous injection is recommended as the best method of administration. There can be no doubt that, in many cases, a single injection produces sufficient protection. Such persons are, as a rule, those who have already been sensitized by diphtheria bacilli. For the ordinary run of cases at least three injections should be given. The first injection then plays the part of a sensitizer. Experience shows that sensitization occurs after from ten to fourteen days, which makes it necessary that the second injection should not be given until after an interval of not less than ten days. In this country the subject has been studied by William H. Park and his associates,1 who found that this form of active immunization gave rise to decided antitoxin production in 22 per cent, of susceptible persons. The interval between vaccination and the development of immunity was generally long — as a rule, not less than two weeks. Under conditions of exposure about 20 per cent, of those who failed to respond were found to develop clinical diphtheria. Only those persons yielding positive Schick reactions require immunization when exposed to diphtheria and in immediate danger. Antitoxin alone may be used or, if a longer protection is desired and time permits, the T.-A. mixtures may be employed. The remedy has not been used sufficiently often to enable us to express an opinion as to its value. Behring believes that its proper use may thoroughly eradicate diphtheria. Obviously, its preparation must be very carefully controlled, and for the present it should be used only in institutions where thorough studies of the blood of patients may be made before and after immunization. Tetanus antitoxin was discovered by Behring and Kitasato in 1892. Since then it has proved of great value in the prevention of lockjaw. While, in general, authoritative opinions regarding its curative value vary, the statistics and the individual experience of many investigators of more recent years show quite conclusively that tetanus antitoxin does possess curative value, and is of distinct aid in the treatment of tetanus, especially when the nature of the disease is understood and the serum is administered accordingly. Preparation and Standardization of Tetanus Antitoxin. — This technic has been described in Chapter XIV. Briefly, it consists in immunizing the horse with gradually increasing doses of tetanus toxin over a period of several months, until the blood of the animal contains the antitoxin in sufficient quantities for therapeutic use. The animal is then bled under aseptic precautions, and the serum, with the addition of a small amount of preservative, constitutes the antitoxin of commerce. Several manufacturers concentrate the antitoxin in the same manner as diphtheria antitoxin is concentrated. In view of the very large doses required in the treatment of tetanus this is quite desirable. The American unit is denned as the amount of antitoxin required just to neutralize 1000 fatal doses of tetanus toxin for a 350-gram guinea-pig. The United States Government has adopted this unit, and supplies the different producers with standardized toxin for. testing the antitoxin. Action of Tetanus Toxin. — It may be well to recall briefly the main features concerning the pathogenesis of tetanus, as successful treatment depends upon a thorough understanding of these principles. 1. Tetanus is a local infection accompanied and characterized by a general toxemia. The bacilli and spores never gain access to the blood, and are never distributed through the tissues and internal organs, but reside at the local site of infection, where they produce a powerful toxin, which, when absorbed, is responsible for the main lesions and symptoms of the infection. Therefore while the blood of the tetanus patient is sterile, it usually contains the toxin. Neisser has produced tetanus in mice by giving them subcutaneous injections of the blood of a tetanus patient. 2. Tetanus toxin has a strong affinity for nerve tissue, and this constitutes the most important feature in the pathogenesis of the disease. The toxin is rapidly absorbed from the local site of infection into the blood and lymph-streams, where it is distributed to other muscles and reaches the central nervous system indirectly through absorption by the end-plates of motor nerves. As expected, absorption is most likely to occur along the motor nerves supplying the parts injured, and for this reason the muscles and nerves should be infiltrated with antitoxin as soon as possible after an injury has been received. According to Mayer and Ransom, Marie and Morax, absorption occurs along the axis-cylinders of motor nerves, the intramuscular endings of which the toxin penetrates. The experiments of Field, Cernovodeanu, and Henni indicate, however, that the toxins are absorbed by way of the lymphatics of the nerves, and not by way of the axis-cylinders; the latter view is now most generally accepted. Even though the toxin gains entrance to the blood, it cannot injure the motor nerve tissue directly, as, for example, by means of the bloodvessels supplying the central nervous system. As was previously stated, the toxin in the blood and lymph channels may reach the central nervous system only in an indirect manner, through the end-plates or lymphatics of other motor nerves. Ascending centripetally along the motor plates and lymphatics, the poison reaches the motor spinal ganglia on the side inoculated; it then affects the ganglia on the opposite side, making them hypersensitive. The visible result of this hypersensitiveness is the highly increased muscle tonus — i. 6., rigidity. If the supply continues, the toxin next affects the nearest sensory apparatus: there is an increase in the reflexes, but only when the affected portion is irritated. In the further course of the poisoning the toxin as it ascends continues to affect more and more motor centers and also the neighboring sensory apparatus. This leads to spasm of all the striated muscles and general reflex tetanus (Park). 3. Regardless of the severity of the infection, there is always an incubation period in tetanus during which the bacilli multiply and produce toxin which is traveling toward the tissues of the central nervous system. Antitoxin in sufficient amount will neutralize the toxin as quickly as it is produced, and thus protect the infected individual until the leukocytes and other body-cells have destroyed the bacilli and spores. In general terms, the severer the wound and the heavier the infection, the shorter will be the incubation period and the higher the mortality. In acute tetanus the incubation period is less than ten days; in chronic tetanus this period is much longer and more variable. The toxin is produced, and may be absorbed during or at least soon after the first twenty- four hours following infection; this explains thenecessity for administering antitoxin as soon as possible after the injury hasbeenreceived. Action of Tetanus Antitoxin. — 1. Tetanus antitoxin will neutralize free toxin in a chemical manner similar in some respects to that by which neutralization of an acid by an alkali is effected. It is generally believed that as soon as the molecule of antitoxin has become united with a molecule of toxin, the latter is rendered inert. It may be possible, however, for the toxin molecule to become dissociated and attack nerve-cells or ing large doses of antitoxin in order than an excess may be at hand. 2. When tetanus toxin has once united with nerve-cells, it is difficult or impossible for the antitoxin to effect its neutralization. Hence the greatest value of the antitoxin lies in prophylaxis; when properly administered, however, it is possible for the antitoxin to aid in the cure of tetanus, and its use should never be omitted in the treatment of any case. The value of antitoxin in the treatment of tetanus is probably dependent upon the following two factors: (1) Neutralization of all free toxin as quickly as it is secreted and before it is absorbed by the nervous tissue; (2) actual dissociation or neutralization of some of the toxiii " loosely united" with nerve-cells or suspended in the lymph after it has left the capillaries and before it is taken up by the nerve-cells. 3. Aside from its chief antitoxic action, anti-tetanus serum probably contains anti-aggressins or bacteriotropins that aid phagocytosis by overcoming their repelling or negatively chemotactic influence. This may, however, be accomplished by simple neutralization of the toxins, which impairs their leukotoxic action sufficiently to permit living leukocytes to engulf and destroy the bacilli. Methods of Administering Tetanus Antitoxin. — Recent investigations and case reports show quite conclusively that in the treatment of tetanus as much depends upon the method of administering antitoxin as upon the quantity administered. 1. Absorption by the subcutaneous route is so slow that it should not be depended upon in the treatment of tetanus. While it is true that the mortality of tetanus has been reduced about 20 per cent, by the administration of large amounts of serum by this route, it should be emphasized that a smaller amount, given subdurally or intravenously, will yield even better results. Knorr has shown experimentally that after subcutaneous injection the maximum quantity of antitoxin is not found in the blood until twenty-four hours have elapsed. Since every hour counts heavily in the chances for recovery when symptoms of tetanus have appeared, it may be laid down as a general rule that the first doses of antitoxin should be given subdurally or intravenously. The subcutaneous route may be chosen when serum is given for prophylactic purposes at the time of injury, but should not be relied upon in the treatment of tetanus. 2. Intramuscular injections may be given to keep up the good effect of antitoxin after the first doses have been given subdurally and intravenously, and are to be preferred to the subcutaneous route whenever the physician is unable to inject the serum subdurally and intravenously. 3. For the rapid neutralization of toxin free in the body-fluids serum should be given intravenously. In the treatment of tetanus from 10,000 to 20,000 units may be given by this route as early as possible. While it is conceded that when the toxin has become firmly bound to the tissues of the central nervous system dissociation by the use of antitoxin is not possible, yet one can never know, in a given case, how firm this union has become, and clinical results, supported by animal experimentation, show that life may be preserved by large doses of antitoxin injected into the blood. 4. The experimental work of Pennin,1 Park and Nicoll,2 supported by the clinical results reported by various observers, shows quite conclusively that the subdural route is a very efficacious and valuable avenue by which to administer antitoxin in the treatment of tetanus. The serum should be given by the gravity method, in exactly the same manner as in giving antimeningitic serum. To insure its thorough dissemination throughout the spinal meninges the antitoxin should be diluted, if necessary, with normal salt solution. As a rule, the amount injected should be slightly less than the amount of fluid withdrawn. In the case of a "dry tap, " if the operator is reasonably sure of having entered the canal, from 3 to 5 c.c. of serum may be injected. It is generally necessary to repeat this injection within twenty-four hours. The reason for administering antitoxin subdurally is apparent when it is remembered that neither the central nervous system nor the peripheral nerves take up antitoxin direct from the blood (Park). Only after very large intravenous doses are traces of antitoxin found in the cerebrospinal fluid, and animals passively and actively immunized may be rendered tetanic if the toxin is injected directly into the central nervous system or into the nerve. While antitoxin injected subduraliy finally passes over into the blood, it will neutralize any free or dissociated toxin before the latter has developed any harmful tendency. 5. To neutralize any toxin that may have been absorbed by a nerve it may be advisable to inject antitoxin directly into the nerve, and these intraneural injections under anesthesia are advised by Ashhurst, John, and others as part of the rational treatment of tetanus. Prophylaxis of Tetanus. — The most successful preventive treatment, and practically the only successful curative one after the disease has developed, is by means of tetanus antitoxin. As a prophylactic remedy this antitoxin exceeds in value even diphtheria antitoxin; therapeutic- cells of the spinal cord. One of the greatest dangers from this terrible infection lies in the fact that while the local lesion may show no signs of disturbance, the central nervous system may suddenly manifest symptoms of poisoning. The wounds that are likely to contain the tetanus bacillus are the following: All wounds that may contain dirt contaminated by manure, such as that from the streets, stables, barns, and even fields; wounds made by firecrackers or toy pistols; gunshot wounds, especially those made by blank cartridges; crushing injuries, made by machinery or in other ways. The feet and hands are especially prone to be infected with tetanus germs. Street injuries that are not deep or perforating, but grinding and lacerating, are very likely to develop tetanus infection. It has also been stated that tetanus bacilli may be harbored in an old injury, and yet cause no symptoms until some additional injury or general disturbance of the body causes the normal protection against infection to be broken down, when toxins from the bacilli may be absorbed and tetanic symptoms develop. This theory would seem to be responsible for an otherwise apparently unaccountable development of tetanus. From what has been said it will be seen that any injuries received on the street, or those inflicted on workers about horses or cattle and in stables, are more likely to develop tetanus than are injuries received in other ways. New-born babies may be infected through the stump of the umbilical cord. Likewise a suppurating wound, or even a fresh wound, which may be innocent at first, may become infected with the tetanus bacillus if the wound or suppurating focus is improperly cared for. Many cases of vaccinal tetanus can thus be accounted for, i. e., due to negligence in the care and treatment of the wound. It is now generally agreed that proper treatment of the original wound, combined with the administration of tetanus antitoxin, will surely prevent the development of lockjaw, In former years Fourth of July wounds claimed a heavy toll of fatalities due to tetanus. Owing to the efforts of the American Medical Association municipalities have been urged to adopt legislative measures for enforcing a saner form of celebration, and efforts have been made to educate physicians in the proper care of these wounds and to impress upon them the great prophylactic value of tetanus antitoxin. These efforts have been crowned with success, as statistics collected from all parts of the country will show. In 1903 there were in the United States 406 deaths from tetanus; in 1904, 91; in 1905, 87; in 1906, 75; in 1907, 6 deaths, and in 1913, 4 cases with 3 deaths. While it is not within the province of this chapter to deal with surgical technic, the proper cleansing and care of a wound constitute so important a part of the prophylaxis of tetanus that I shall refer to this subject, quoting largely from the technic recently described by Ashhurst and John.1 with a 3 per cent, alcoholic solution of iodin. 2. All foreign material should be removed from the wound, and to do this properly all parts of the wound should be made accessible by wide incision, under ether, if necessary. This is especially true of a puncture wound. It should then be freed from all tags and loose shreds of tissue by means of the scissors, and the whole wound swabbed with the 3 per cent, iodin solution. The wound should next be dressed with gauze soaked in the same solution. The use of strong caustics is inadvisable, as they cause sloughing and tend to produce a good focus for the growth of tetanus bacilli. 3. The wound should be dressed daily at first, being exposed and thoroughly irrigated with hydrogen dioxid solution, and then dressed with the gauze saturated with the iodin solution. As soon as healthy granulations have formed, balsam of Peru applications should be made. 4. Antitetanic powders have been prepared, made up with antiseptics, and although experimentally their use has seemed to be successful in preventing the development or absorption of tetanus toxin, still it has not as yet shown that these results were not merely due to the strong antiseptic that was combined with the antitoxin powder. It might, however, be well to apply tetanus antitoxin and antitetanic powder to the open wound, but these remedies are not to be relied upon nor accepted as substitutes for the injection of antitoxin. used incorrectly. 1. Antitoxin should be given as soon as possible after the wound has been inflicted, and best at the time the primary treatment is given. The antitoxin should be injected "as near the wound as possible, so as to flood the tissues in the immediate vicinity, " and, if possible, it should be given intramuscularly, so that the motor nerves may absorb it rapidly. 1 Amer. Jour. Med. Sci., 1913, cxlvi, No. 1. lactic dose. 2. From the fact that tetanus antitoxin is one of the albuminous constituents of horse serum that are foreign to the human system, in the human being the antitoxin is rapidly eliminated in from eight to ten days after the injection is administered. Knorr has found, as the result of animal experiments, that by the sixth day only one-third, and by the twelfth day only one-fiftieth, of the optimum quantity remained in the blood. Hence it is important, if antitoxin is to prove useful, that it should be present in the system for two or three weeks after receipt of the injury, especially as it cannot be determined when the tetanus bacillus first gained access to the wound. There should be a second intramuscular injection of 1000 units of antitoxin about the end of the first week, and perhaps a similar dose at the end of the second week. While certain individuals may develop serum sickness, no dangerous symptoms have been observed to result from the use of tetanus antitoxin. 3. If the surgeon is first consulted several days after the injury has been inflicted, the wound should be opened and dressed as previously described, and, in addition to the intramuscular injection of 1500 units of antitoxin in the neighborhood of the wound, it will be good practice to inject an additional 5000 or 10,000 units intravenously. It requires at least twenty-four hours for the antitoxin to be absorbed from the subcutaneous tissues, and immediate neutralization of any toxin present in the blood may mean a great deal from the standpoint of prognosis if tetanus should develop. Treatment of Tetanus. — While the great value of antitetanic serum as a preventive is unquestioned, as a specific cure it has fallen short of the earliest expectations. It has been shown experimentally, however, that tetanus antitoxin may save the lives of animals already manifesting the symptoms of an otherwise fatal intoxication. In order to accomplish this result the serum must be given in doses several hundred times the size required merely for protective purposes, and it must be injected within a short time — from twenty-four to thirty-six hours — after the onset of the tetanus. Furthermore, statistics favor the use of the serum as the mortality has been reduced from 80 to 85 per cent, to 60 or 65 per cent, in cases receiving serum treatment. The recognition of the natural limitations of the serum treatment of tetanus will serve to emphasize the importance of its proper administration. A large number of units must be given, and must be injected serum. Surgical Treatment. — 1. The site of the wound should be located, and if possible incised under ether or chloroform anesthesia and thoroughly cleansed of foreign material and necrotic tissue. It should then be swabbed with the 3 per cent, alcoholic solution of iodin, washed with hydrogen dioxid solution, and packed loosely with gauze soaked in the iodin solution. 2. Cauterization with pure phenol, followed by alcohol, may be employed, but, as a rule, the weaker germicide is preferable in order not to produce necrosis of the tissues, which furnishes pabulum for bacterial growth. The wound should be dressed daily. Serum Treatment. — A maximum amount of antitoxin should be given the patient as soon as possible, and the greater the delay in giving the antitoxin, the greater is the amount required. Since absorption after subcutaneous injection is very slow, valuable time may be lost, and since enormous amounts must be given, at great expense, this route possesses much less value than the intravenous and intraspinal methods. 1. Administer intravenously from 10,000 to 20,000 units of antitoxin at once, and repeat the dose if no effect is apparent or if the good effect wears off in about from eighteen to twenty-four hours (the technic is described on p. 742). After one or two intravenous injections the good effect may be maintained by direct intramuscular injections of from 5000 to 10,000 units for one or two doses. 2. From 3000 to 5000 units should be given intraspinally by means of lumbar puncture. This dose should be repeated every twenty-four hours unless the symptoms have markedly ameliorated. The technic of this injection is described on p. 746. A quantity of cerebrospinal fluid should be removed before the serum is injected. After the first injection the fluid may be found to have become cloudy, with a large increase of cells, especially of the polynuclear variety, although bacteriologically it may be sterile. This outpouring of leukocytes is probably a reaction to the irritant effect of the serum, and especially of the preservative it contains. 3. If a surgeon is at hand, from 500 to 1000 units of antitoxin should be injected slowly intravenously into the sheaths of the nerve-trunks leading from the infected region. These injections are directed to be made as near the trunk as possible, and to distend the nerve so as partly to neutralize and partly mechanically to interrupt the passage of toxin to the cord or brain. light chloroform anesthesia. General Treatment. — A large number of substances have been advocated in the treatment of tetanus; of these, the most common are injections of phenol and intraspinal injections of magnesium sulphate. While phenol may be well tolerated by tetanus patients, Ashhurst and John believe that all these treatments are of little value, and that spinal injections of magnesium sulphate are dangerous. 1. Chloral hydrate and potassium bromid should be given by mouth or by rectum, in sufficient quantities to produce sleep and quiet. Drugs, such as those of antagonistic physiologic activity, are more or less successful and frequently of aid when given in conjunction with the antitoxin. 2. While combating the disease, the general care of the patient should not be forgotten. A purgative should be administered early. Simple, nourishing, non-stimulating food should be given by the mouth, if possible, or by the nasal tube, if necessary. Absolute quiet should be maintained. Distention of the bladder from retention of urine should be guarded against. If water is not well absorbed, and especially if there is peritoneal or pelvic inflammation, saline injections into the colon should be given. Results of the Antitoxin Treatment of Tetanus. — As was previously stated, the prophylactic value of tetanus antitoxin has been proved beyond any reasonable doubt. This does not imply, however, that the simple introduction of 1000 units of antitoxin beneath the skin will surely protect the patient, as the percentage of cases developing tetanus even after the serum has been given is altogether too high. As was pointed out under Prophylactic Treatment, the wound must receive thorough surgical attention, and the antitoxin must be injected in such places where it will have the greatest opportunity to neutralize the toxin. Even if tetanus should develop under these conditions, it is likely to be mild and the prognosis would be much more favorable. Tetanus antitoxin has likewise been very successful in veterinary practice, especially after castration and other operations, in injuries, and among horses used for the purpose of producing diphtheria antitoxin and other immune serums. While the curative value of tetanus antitoxin has not come up to expectations, more recent carefully prepared statistics indicate that, with serum treatment, the mortality is reduced at least 20 per cent. This includes cases treated by the subcutaneous injection of antitoxin, and it must be em- phasized that, in order to secure the best results, tetanus must be treated in a rational manner according to its pathology. Under these circumstances we can confidently expect a greater reduction in mortality. But at any rate no physician should withhold antitoxin in the treatment if there are any possible means of obtaining it. If only 3000 units may be had, it is far better to inject this amount intraspinally than subcutaneously. Pennin,1 in a recent and thorough review, reaches the general conclusion that anti-tetanus serum has reduced the mortality of tetanus approximately 20 per cent. He gives figures from Denmark that are especially valuable, because they were gathered from a small area, and hence represent fairly uniform conditions: Of 199 cases not receiving serum, only 21 per cent, recovered; whereas of 189 cases treated with serum, 42.3 per cent, recovered. Of 92 acute cases with an incubation period of less than ten days 24.2 per cent, recovered when serum was used, whereas of 94 cases treated without serum only 5.3 per cent, recovered. It is significant that these Danish figures correspond closely to the American statistics and those of other countries. Irons2 has recently tabulated the results of 225 cases of tetanus treated with antitoxin collected from hospitals and private records for the years 1907 to 1913. The mortality in all cases receiving serum was 61.77 per cent.; in 21 cases without serum the mortality was 85.7 per cent. The latter figures correspond quite closely with the general mortality of about 85 per cent, of tetanus treated without serum. Irons' figures also show the influence of large doses of antitoxin; of 57 cases receiving a small dose of antitoxin (3000 units or less subcutaneously), the mortality was 73.7 per cent.; of 143 cases receiving large doses (over 3000 units subcutaneously, or 3000 or less intraspinally or intravenously), the mortality was 57.3 per cent. Magnesium sulphate was given intraspinally in 18 cases which also received serum; in 4 cases — 2 acute and 2 chronic — the patients recovered, giving a mortality for the group of 77 per cent. In 2 cases death recurred shortly after injection with symptoms of respiratory failure. In view of this evidence in favor of antitoxin in the treatment of tetanus it is apparent that the physician is compelled to give every patient with tetanus the opportunity to obtain this 20 per cent, or more benefit by administering the serum promptly and correctly. Soon after the discovery of a bacillus of dysentery by Shiga in 1892 the treatment of bacillary dysentery by the use of immune serums was undertaken. Following the discovery of the etiologic importance of Shiga's bacillus in the dysenteries of Asiatic countries, similar investigations were made in various parts of the world and various bacilli were isolated. At first these microorganisms were all regarded as being identical, but further investigation has shown that marked differences are apparent, and two main types are now recognized: one type (Shiga) does not ferment mannite and produces a soluble or extracellular toxin, and a second type (Flexner-Harris, Hissy, etc.) ferments mannite and does not produce an extracellular toxin. A further discussion of these bacilli will be found in Chapter VII. Dysentery caused by the bacilli of the Kruse-Shiga type may be regarded as a form of intoxication analogous to the intoxication of diphtheria. The intestine, where the bacilli lodge, corresponds to the throat, which is the site of infection in diphtheria; here the bacilli develop and produce their toxins, and these toxins, when absorbed into the circulation, in turn produce the symptoms of the disease. Antitoxin has been prepared for the bacilli of the Kruse-Shiga type, and these have yielded fairly satisfactory results in the prophylaxis and cure of this variety of bacillary dysentery. Antiserums for the mannitefermenting group of bacilli (Flexner, Harris, Hess, Duval, etc.) have not proved of much value in the treatment of these infections. Bacilli of the latter group are largely responsible for the dysenteries in this country, and also for a percentage of cases of ileocolitis of infancy. Since the antiserum of the Shiga bacillus is of practically no value in the treatment of infections caused by bacilli of other groups, the serum treatment of dysentery is employed mainly in European and Asiatic countries, where infections with this group are common. After fairly extensive trials in this country the serum treatment of infantile diarrheas and true dysenteries has proved disappointing. Administration and Uses. — Dysentery antitoxin has been used both in the prophylaxis and in the cure of this infection. The doses of serum advised by various observers vary considerably, owing to the marked differences that exist in the potency of these serums. Since the various manufacturers do not employ the same standards, the physician should use the serum in accordance with the printed directions that accompany each package. For prophylactic purposes, usually from 10 to 20 c.c. are recommended, and it is further advised to repeat the injection after two or three weeks, as the protection lasts only a short time. For curative purposes, Shiga has advised 10 c.c. for mild cases and from 20 to 60 c.c. for severer cases. It may be necessary to repeat the injections several times. Vaillard and Doyle have given as much as from 80 to 100 c.c., and have repeated this dose on the following days. When the serum is being used during an epidemic, it is advisable to ascertain beforehand the nature of the infection, as the antiserum for the Shiga bacillus is highly specific and is not likely to prove of value in the treatment of infections caused by the Flexner type of bacillus. Otherwise a polyvalent serum should be used. The injections have usually been given subcutaneously. Better results would, no doubt, be obtained in the treatment of severe infections by administering large doses of serum intravenously. Results. — Adequate statistics regarding the value of the serum in the prophylaxis and treatment of dysentery are not yet available. From the prophylactic standpoint, encouraging results have been reported by Kruse, Shiga, Vaillard and Dopter, Rosculet, and others, and it would appear that passive immunization is of value in combating localized outbreaks, such as occur in institutions and armies. From the curative standpoint, most observers agree that the use of a potent serum will reduce the mortality of acute cases at least from 30 to 50 per cent. Shiga reports a drop in the mortality in Japan of from 22 to 26 per cent, to 9 to 12 per cent. ; Kruse obtained a reduction in mortality of about 10 per cent. Vaillard and Dopter 1 treated 96 cases, with but 1 death; Rosenthal2 treated 157 cases with 7 deaths, — a mortality of 4.5 per cent, as compared with that of 10 to 11 per cent, occurring in other German hospitals. Coyne and Auche3 treated 11 cases due to the Flexner type of bacillus and report good results. Ruffer and Willmore,4 Violle,5 Rogers,6 Brau7 and Bahr8 have also reported favorably upon the use of the serum. A highly potent and polyvalent serum should be in readiness during war, and particularly in camps and hospitals. In a thorough investigation made in the United States in 1903 by the Rockefeller Institute, under the direction of Flexner, it was found that the results of the serum treatment of ileocolitis, among children at least, were quite disappointing. This is largely due to the fact that several different strains of bacilli may be the cause of an infection, and unless a corresponding antiserum is employed for the particular type causing the infection in a given case, good results cannot be expected. Probably if some means were discovered for making a prompt bacteriologic diagnosis, and if several immune serums were on hand for the treatment of infections caused by the main types, after the methods worked out by Neufeld, Dochez, and Cole in the treatment of pneumonia, good results may be obtained. The curative effect of dysentery antitoxin is shown by a reduction in the number of stools, by the fact that blood and pus disappear from the discharges, pain and tenesmus are relieved, the temperature becomes normal, and the patient gains in weight. Individual observers are frequently enthusiastic over the results obtained in individual cases, and no doubt these are striking in those instances where the antiserum appears to be specific for the particular form of infection. THE SERUM TREATMENT OF HOG CHOLERA While the cause of hog cholera has not as yet been discovered, it is a well-known fact that the virus is present in the blood of infected animals, and it is possible, by immunizing healthy hogs with gradually increasing doses of infected blood, to prepare a potent immune serum that will prove of value in the prophylaxis and cure of hog cholera. The nature of this serum is unknown. It possesses many of the features of an antitoxin, and for the present may be classed with these. Production and Standardization of Hog Cholera Serum. — Healthy hogs weighing about 100 pounds are selected, and injected subcutaneously with 40 c.c. of hog cholera serum per hundred pounds of weight. Two or three days following this protecting dose they are injected intravenously with 3 or 4 c.c. of sterile, defibrinated blood, obtained from an animal suffering from the disease; or the animals may be exposed in pens known to be infected. If the animals live for one month without showing evidences of toxemia, they receive another injection of 5 c.c. of infected blood (virus). Two or three weeks later they receive another injection of from 15 to 20 c.c. of infected blood; in from fifteen to twenty-one days after this inoculation they receive a final injection of from 4 to 5 c.c. of virus per pound of body weight. Animals tolerating the last injection are said to be hyperimmune, and are bled in ten days. In hyperimmunizing the animal some prefer to inject the virus intraperitoneally instead of intravenously. If this method is adopted, about double the dose of infected blood (virus) is required. About 5 per cent, of animals succumb during the period of immunization. The immunized hogs are bled aseptically from the tail by snipping off the tip, and 5 c.c. of blood per pound of weight is collected in sterile vessels. Each animal is bled once a week until three or four bleedings have been made. In about one week after the last bleeding they are hyperimmunized again by giving them 4 or 5 c.c. of infected blood per pound of body weight, and additional bleedings are made so long as the tail lasts. bodies. In testing and standardizing the immune serum, six hogs, weighing about 100 pounds each, are placed in an infected pen. No. 1 receives no serum and is a control; No. 2 receives 15 c.c. of serum; No! 3 receives 20 c.c.; No. 4 receives 30 c.c.; No. 5 receives 35 c.c.; and No. 6 receives 40 c.c. of immune serum. The animals are allowed to remain in the pens until the control succumbs and the protecting dose of serum has been determined. In this manner we can determine just about the amount of serum required to protect 100 pounds of hog. The Pennsylvania Live Stock Sanitary Board has found that it does not require quite 40 c.c. of serum, but this amount is recommended for safety, and because the weight may not be judged accurately. Hog-cholera serum is used in both the prophylaxis and the therapeutic management of this disease. For prophylactic purposes for each 100 pounds of hog 40 c.c. of serum are injected. These injections are usually given subcutaneously and occasionally intramuscularly. In some instances active and passive immunization is practised by the simultaneous injection of 2 c.c. of virus, together with 40 c.c. of immune serum per 100 pounds of weight. Owing to the danger of spreading the disease, this method is not generally employed. six months after vaccination. For curative purposes the serum has yielded good results, providing it is administered not later than the fourth day after the animal shows evidences of the disease. Several injections may be required, and the intramuscular route should be chosen, because quicker absorption is thus insured. Calf cholera serum has been prepared by immunizing horses with strains of colon, paracolon, and other bacilli belonging to these groups, isolated from calves dying of calf cholera. The immune serum should agglutinate the microorganisms used in its production in dilutions of 1:2000 to 1:500. This serum has proved of value in the prevention of calf cholera, and may be of benefit in the treatment, providing that it is prepared with the same strain or strains of microorganisms responsible for the infection. The nature of snake venom is discussed in Chapter VII, and the method of preparing antivenomous serum is described in Chapter XIV. Calmette's antivenene for cobra venom is useful in the treatment of cobra envenomation, but is not serviceable for the treatment of other snake-bites, as shown by Martin for Australian serpents and by McFarland for American snakes. In the venoms of our snakes, as, for example, the rattlesnake, copper-head, and moccasin, the poison is essentially locally destructive, the respiratory poison being of secondary importance. McFarland failed to immunize horses against this locally destructive poison. Later Noguchi and Madsden succeeded in producing an antiserum, prepared by immunizing horses with venom after the toxophorous groups of the molecules had been destroyed, capable of neutralizing the hemorrhagin of the Crotalus venom. The serums of Calmette, Noguchi, and others are useful in the treatment of their respective envenomations, but aside from India, Brazil, and a few other reptile-infested countries, as well as in zoological gardens and laboratories where snakes are kept, the serums have a very limited sphere of usefulness. preparation of antitoxin in Chapter XIV. Dunbar has prepared an antitoxin for certain pollen; this may be obtained commercially. The method of administration consists in dropping the serum into the eyes and sniffing it into the nose at the onset of an attack. It is necessary for the patient to carry the serum and dropper about, as the effects produced are of short duration, and the patient is subject to repeated reinfections. Subcutaneous injections are not advisable, as considerable local edema is produced, and the amount of protection afforded is uncertain. Many observers, as, for example, Semon,1 McBride,2 Knight,3 Throst,4 Weichardt,5 and others, report that the serum affords a temporary relief which is grateful to the patient, but which cannot be said to be curative of the disease. In some instances it fails altogether, and in these it is reasonable to assume that the antitoxin has not been prepared from the particular pollen that infected the patient. An intolerance to the serum may be excited. ANTIBACTERIAL IMMUNIZATION 787 More recently the possibilities of effecting active immunization against hay-fever have been shown by Claves1 with the pollen of ragweed. The method is still in the experimental stage, but it is reasonable to assume that vaccines may be prepared for the pollen of various plants usually responsible for the hay-fever and autumnal catarrhs of this country. (See page 708.) General Considerations. — It may be stated that antibacterial serums have not been found of equal value to the antitoxins, . either in the prophylaxis or in the treatment of their respective infections. It is true, however, that antimeningococcus serum has reduced the mortality of epidemic cerebrospinal meningitis from 75 to 90 per cent, to 30 per cent, and less, and has thereby firmly established its value in the treatment of this dreaded infection. Recent work in pneumonia has developed a method of serum therapy that has proved of value in the treatment of this disease, and it is likewise true that antistreptococcus and antigonococcus serums yield at times and in individual cases most prompt and happy results. But the expectations for serum therapy that were aroused in 1894 with the discovery of diphtheria antitoxin have not been fully realized, although at the present time the reasons for failure are being studied, understood, and gradually overcome. Granting that serum therapy could be reduced to the simple proposition of bringing specific antibodies into relation with the microorganisms producing a given infection, the process remains quite intricate, largely owing to the fact that although different strains of the same microorganism may possess identical morphologic and biologic characteristics, yet they vary not only in pathogenicity, but also in the specificity of the antibodies that they stimulate the body-cells to produce. In other words, serum therapy is more specific than it is generally considered to be. For instance, the antibodies of one strain of pneumococcus may have little or no action upon another strain, and the same is probably true of the various pathogenic bacilli and groups of streptococci, gonococci, and to a lesser extent also of meningococci. This fact has long been known, and an effort has been made to overcome the difficulty by immunizing horses with a large number of different strains of the same microorganism in the hope that the polyvalent serum so produced would contain sufficient antibodies for all or most infections of the various strains of the particular microorganisms in question. With diphtheria and tetanus bacilli, the soluble toxin is apparently quite 1 Proc. Soc. Exper. Biol. and Med., 1913, x, 69. 788 PASSIVE IMMUNIZATION SERUM THERAPY similar for all strains, so that immunization with the toxin of one yields an antitoxin capable of neutralizing the toxins of all. With dysentery bacilli, snake venoms, and pollens, however, the toxins are more specific, and produce more specific antitoxins. Recent work in pneumonia by Cole and Dochez and their coworkers in the Rockefeller Institute, and Neufeld in Germany, indicates a more promising future for antibacterial immunization. These investigators have been able to divide pneumococci into four main groups, have worked out a relatively quick method of determining the group to which a particular pneumococcus belongs, and have prepared immune serums for these main groups. By injecting the serum corresponding to the strain producing a given infection, encouraging results have been obtained in the treatment of pneumonia, whereas the polyvalent serums have been found, after quite extensive use, to yield indifferent results, due in part to a relatively low content in the particular antibodies for that certain strain causing a given infection. These investigations in pneumonia are of great importance because they reveal an immense field of interesting and similar researches in streptococcus, gonococcus, meningococcus, typhoid, and other infections. While it is obviously impossible to prepare an immune serum for each and every strain of microorganism, it may be possible to subdivide strains into a few main groups and then discover a method for quickly determining to which group a particular culture belongs, so that the corresponding immune serum may be administered. In this manner we may be able to reduce the 30 per cent, mortality still remaining in epidemic meningitis and otherwise place the treatment of specific infections upon a more strictly scientific basis, as in the serum treatment of diphtheria. As previously stated, the method and route of injecting an immune serum are of considerable importance in serum therapy. Large doses of serum should be given until the desired effect is secured, or until it becomes evident that more can be produced. In the mean time manufacturers should make every effort to produce potent serums and to concentrate them, if possible, just as diphtheria antitoxin is concentrated. THE SERUM TREATMENT OF MENINGOCOCCUS MENINGITIS During the pandemic of meningococcal cerebrospinal meningitis in 1904-05 several laboratories sought to produce an immune serum for the purpose of treating human cases of this infection. THE SERUM TREATMENT OF MENINGOCOCCUS MENINGITIS 789 After pursuing experimental studies on the subject on the lower animals, Jochmann,1 in 1905, immunized a horse and used the serum in the treatment of 38 cases of epidemic meningitis. At first he employed the subcutaneous method of injection, and later he used the intraspinal method. The results were quite encouraging, and during the following year 30 more cases were treated, with a resulting mortality of 27 per cent., as against a mortality of 53 per cent, in untreated cases. At about the same time Kolle and Wassermann2 reported that they had prepared an antimeningococcus serum, which had not, however, up to that time been used in the treatment of human infections. A year later serum was administered subcutaneously and then intraspinally, with encouraging results. In this country Park had, in 1905, prepared an antimeningococcus serum, which was used in the treatment of 20 cases in Hartford, Conn., by subcutaneous injection, but without beneficial results. Jochmann had, in the mean time, shown the superiority of intraspinal injections, and this method soon supplanted the subcutaneous method. In 1905 Flexner began a series of studies regarding experimental meningococcus infections in the lower animals, and the therapeutic value of antimeningococcus serum. These valuable experiments attracted the attention of the world, and placed this method of treatment upon a firm basis. In 1906 Flexner3 proved that a specific immune antimeningococcus serum could be produced that, if injected intraspinally, would save the lives of monkeys. Later horses were immunized and the serum used in the treatment of human infections during an epidemic in Akron, Ohio, in May, 1907. In a short time the serum was used extensively in other epidemics, and a report of these early cases was made by Flexner4 in 1907. A later report by Flexner and Jobling,5 covering the treatment of 400 cases, showed that the mortality had been reduced from 75 per cent, to below 30 per cent. In 1909 they reported6 upon 712 cases treated with the serum, with a mortality of 31.4 per cent. In a more recent report Flexner7 reviewed all the cases — 1300 in number —gathered from all parts of the world, treated with serum prepared in the Rockefeller Institute. The general mortality rate is given as 30.9 per cent., as against 75 to 80 per cent, among cases not receiving serum treatment. Of 1394 cases treated with serum during the Texas epidemic1 (1912), the mortality was 37 per cent., as compared with a mortality of 77 per cent, among 562 cases receiving no serum. Good results have been reported by many observers with Jochmann's, Kolle and Wassermann's, RuppePs, Paltauf s, and Dopter's serums, and the serums have been prepared by several commercial biologic laboratories, so that the curative value of antimeningococcus serum is definitely established. Nature of Meningococcus Meningitis. — Bacteriologic and pathologic evidence indicates that the first stage of meningococcus meningitis consists of a meningococcus bacteremia, the virulent meningococci gaining access to the blood-stream through the upper air-passages. Later the infection becomes localized in the spinal and cerebral meninges. It is probable that the microorganism causes a primary nasopharyngitis, and in some instances the meninges may be infected by direct extension through the sphenoid and ethmoid sinuses. The main symptoms and lesions of the disease, and several of the complications, for example, the paralyses, eye complications, deafness, hydrocephalus, and mental disturbances, are probably directly due to suppuration of the meninges, with involvement of accessory and motor nerve-roots, meningeal irritation, and pressure from the accumulation of exudate in the ventricles and subarachnoid space. Complications, such as arthritis, pyelitis, endocarditis, adenitis, etc., are due to the bacteremia, which may become chronic and be accompanied by deposits of meningococci in the various tissues and organs. In addition to these complications there is probably a varying degree of general toxemia, due to a soluble toxin or endotoxin liberated through lysis of the cocci. Treatment of Epidemic Meningitis. — Although cerebrospinal meningitis may be considered primarily as a general infection, in the majority of instances local suppuration of the meninges constitutes the main lesion. For anatomic and physiologic reasons, however, it is impossible to treat the disease according to the ordinary principles governing the treatment of localized suppuration, as, for example, by continuous drainage and by cleansing the affected parts with germicidal solutions. Unaided, the leukocyt.es and body-fluids are generally unable to destroy the cocci and terminate the infection before serious harm to important nerves and nerve-centers has resulted, so that epidemic meningitis, with a mortality of from 75 to 90 per cent., and followed by more or less In administering antimeningitic serum we aim to assist the patient's leukocytes and body-fluids to overcome the infection. Repeated spinal punctures remove portions of the infective material mechanically, but the greatest dependence in bringing about quick destruction of the cocci and effecting recovery of the patient is to be placed upon the serum. Preparation of the Antimeningococcus Serum. — Method of Flexner and Jobling. — 1. Many strains of meningococcus are used in order that a polyvalent serum may be prepared. Fresh strains from new epidemics and sporadic cases are constantly added. ''Fast " strains, or those isolated from cases in which the serum has produced noj beneficial effect, are especially desirable. By means of complement-fixation tests Olmstead1 and her associates have been able to classify meningococci into two main groups; similar results have been secured by Kitchens and Robinson2 with a protective test. Both tests are apparently highly specific and serve to differentiate meningococci from similar microorganisms. of ascitic glucose agar, neutral to phenolphthalein. 4. In preparing the autolysate, the cultures are subcultured first on glucose-agar slants without serum. After twenty-four hours' growth about 3 c.c. of salt solution are added to each slant, and the culture emulsified. One cubic centimeter is then poured over the surface of glucose-agar slants in large 500 c.c. Blake bottles. After twenty-four hours' incubation heavy, uniform, and diffuse growths are secured. Add 10 c.c. of normal salt solution to each bottle and wash off the culture. If necessary, a long heavy platinum loop may be used. Each bottle is tested for contamination by staining a smear according to the method of Gram. Each bottle is emptied into a common vessel; 2 per cent, toluol is added, mixed well, and incubated for from eighteen to twenty-four hours. The toluol is then allowed to evaporate, or it may be immediately filtered off through sterile gauze saturated with salt solution. The preparation is kept in a refrigerator and should be prepared fresh every month. 5. The injections are given subcutaneously about the neck and abdomen. Young and healthy horses are selected for the purpose. The first dose consists of 2 c.c. of the autolysate, and this is gradually increased, depending on the manner in which the animal reacts, until 10 c.c. are given in a single dose. Then inject 2 c.c. of living culture diluted with two parts of salt solution, and increase the doses, the same as with the autolysate, until 10 c.c. of culture are given at one injection. Next inject living cultures and autolysate alternately, until a maximum of from 30 to 35 c.c. are given in one dose; this last is then used as the constant dose until the immunization has been completed. two weeks, from six to eight liters of blood being removed at each sitting. The serum is separated and preserved with trikresol. Recent investigations indicate that trikresol may be partly responsible for paralysis of the respiratory centers, and at present every effort should be made to collect and market the serum in a strictly aseptic manner, so that none or but very little preservative is required.1 Efforts are being made at present to discover an efficient volatile antiseptic that may be driven off by warming the serum at body temperature. Rapid Method of Amoss and Wollstein.2 — These investigators have recently advocated a rapid method of immunization consisting in inoculating alternately several strains of living meningococci and parameningococci and the autolyzed products of each, by which a potent polyvalent serum may be produced in eight to twelve weeks instead of in the ten months required by the subcutaneous method. In the preparation of a polyvalent serum a twenty-four-hour agar slant culture of meningococci is removed with 2 c.c. of salt solution and 0.1 c.c. suspended in 15 c.c. of salt solution and injected very slowly into the circulation of a horse. The temperature is taken hourly and should not rise over 3° C.; twenty-four hours later 0.2 c.c. of suspension, and on the third day 0.3 c.c. are given. After the lapse of seven days a series of three injections of living parameningococci are given in doses of about 0.3 c.c. of the emulsion or sufficient to give a temperature reaction of about 2.5° to 3° C. After a lapse of seven days three intravenous injections of an autolysate composed of equal parts of autolysate of meningococci and parameningococci are given. A series of three injections of living meningococci and parameningococci follow in doses which may be run up to 0.6 c.c. of emulsion, with every third series consisting of injections of the mixed autoly sates; after ten to twelve weeks a potent serum is generally produced. In order to make the serum as polyvalent as possible a large number of strains of meningococci and parameningococci should be used. Severe reactions due to hypersensitiveness of the horse to the meningococci or its products are especially likely in the first dose of each series after three or four series of injections have been given. In order to desensitize, a portion of the first injection of each series is injected intravenously, and two hours later the remainder of the dose is given. Danger due to agglutinated cocci is lessened by diluting the dose in 15 to 20 c.c. of salt solution and injecting very slowly. Standardization of Antimeningococcus Serum. — An accurate method of standardizing antimeningococcus serum has not as yet been devised. In the selection of a serum physicians must, therefore, be guided by the reputation of the manufacturers. An antimeningococcic serum of high antibody content has antitoxic, bacteriotropic, and bactericidal properties. Kraus and Dorr consider that the chief function of the serum is antitoxic; Flexner and Jobling, Neufeld, Jochmann, and Wassermann believe that its bacteriotropic properties are its most important qualities. The following methods for testing an immune serum are in use or have been advocated; none of them is, however, sufficiently reliable to serve as a definite measure of antibody content or of curative value; two of them, the bacteriotropic and the complement-fixation test, are most widely used in laboratories for the purpose of estimating the antibody content of a serum. 1. Bacteriotropic Titration. — While the antimeningitic serum was being prepared at the Rockefeller Institute, Jobling* used the opsonic test in standardization as the method of choice, on account of the part taken by specific opsonins in promoting recovery from meningococcus infections. As a definite and suitable standard of strength Jobling has suggested that a serum be accepted as satisfactory when it shows 2. Complement-fixation Tests. — The advantages of these tests are that the same polyvalent antigen may be used as is employed for purposes of immunization; the technic is simple, and the reactions are usually sharp and definite. According to Sophian, in a series of comparisons with opsonic and complement-fixation tests the results corresponded in every instance, a high opsonic content being accompanied by a high complement-fixation reading. The latter indicates, at least, that the horse has responded to immunization and that curative antibodies probably are present. Laboratories usually adopt their own standards in preparing antimeningococcic serum. In the complement-fixation test Kolle requires complete inhibition of hemolysis with 0.1 c.c. of serum. again suspended in 95 per cent, ethyl alcohol. 6. This process of centrifugalization and resuspension is repeated a second and a third time, but with ethyl ether instead of alcohol, the original volume of the suspension being reduced one-half each time. over phosphorus pentoxid. For use, a small amount of the powder, 0.02 gram, is carefully ground in a mortar, 20 c.c. of normal salt solution being gradually added. The technic of these tests is given on page 524. 3. Agglutination Tests. — These tests are readily conducted with the polyvalent antigen used in immunization, a macroscopic technic, as that described on page 301, being employed. Kolle regards a serum as satisfactory when it causes agglutination of meningococci in dilutions. up to 1: 5000. 4. Animal Inoculation Tests. — These tests have been found quite irregular and impracticable for general use. As stated by Jobling, not only does the pathogenicity of the meningococcus vary considerably from day to day, but the resistance of animals to this microorganism is also quite variable. By preparing a large quantity of bacterial emulsions and using sufficient controls to determine the fatal dose, and by employing a standard lethal dose of emulsions mixed with varying quantities of serum injected intraperitoneally into 250-gram guinea-pigs, some conception of the protective value of a serum may be obtained. Hitchens and Robinson2 have recently perfected an animal inoculation test which promises the best means for testing the potency and standardizing a serum. The M. L. D. of mixed cultures of meningococci is determined by washing off sixteenhour growths of each culture on slants of serum-dextrose agar with 1 c.c. of a 1 : 4 dilution of fresh guinea-pig serum. The emultions are mixed and 0.5, 0.25, 0.12, 0.06, and 0.03 c.c. injected intraperitoneally into white mice. The M. L. D. is the smallest lethal dose at the end of forty-eight hours. In testing a serum 0.5 c.c. vary- ing dilutions are injected intraperitoneally two hours before the injection of 1 M. L. D. culture. These protection tests have been found to parallel the extent of immunization more closely than agglutination or complement-fixation tests. Action of Antimeningococcus Serum. — As previously stated, experiments in vitro show that a potent antimeningitic serum possesses three chief antibodies upon which its curative powers probably depend, namely: (1) Bacteriotropins (immune opsonins), which lower the resistance of the meningococci and facilitate their phagocytosis; (2) bactericidins, which kill the cocci extracellularly, either with or without final lysis; and (3) antitoxins, which neutralize the true extracellular toxin, which some strains of meningococci apparently produce in varying degree. Other than these are the agglutinins, which probably aid in bacteriolysis, and anti-aggressins, which may assist in the process of phagocytosis. Microscopic examination of a direct stained smear of the sediment of cerebrospinal fluid obtained from fresh cases will show large numbers of polynuclear leukocytes and cocci, the majority of the latter being extracellular. As the case improves, whether under serum treatment or spontaneously, the microorganisms diminish in number and become intracellular, frequently appearing clumped and failing to grow in culture. It would appear, therefore, that a cure is brought about partly by means of phagocytosis aided by bacteriotropins; by bacteriolysis through the agency of specific bacteriolytic amboceptors in the immune serum and complements in the spinal fluid and blood-serum, and to some extent by neutralization of a toxin with antitoxin. A potent antimeningococcus serum furnishes these main antibodies, and since the first two must act locally upon the cocci infecting the meninges, the serum must be applied locally and directly by intraspinous and subdural injection, since only traces of immune serum could eventually find their way into the cerebrospinal fluid if the serum were injected subcutaneously or intravenously. On the other hand, in the treatment of meningococcus bacteremia and toxemia the serum should be injected intravenously and subcutaneously. Unfortunately, an immune serum may not contain the antibodies for the cocci producing a given infection, and hence the serum, even though it is skilfully administered in large doses, will have no influence upon the disease. Apparently the cocci of these resistant or "fast" strains are uninjured by the antibodies in the serum. To overcome this difficulty, a large number of different strains of meningococci are used in immunizing horses. If, however, the serum of one laboratory is found to exert no beneficial effect, the physician should use the serum of another, for different laboratories probably immunize their horses with cultures not in common use. It is highly desirable to secure cultures of these "fast" strains. These should be sent at once to laboratories engaged in the production of antimeningitic serum, for the larger the number of these strains used in immunization, the more potent and valuable will the serum be. Administration and Dosage of Antimeningitic Serum. — In Acute Meningitis. — As a rule, serum should be injected into the spinal canal as early in the disease as possible, and in such maximum amount as is compatible with safety. Intraspinal injection is absolutely necessary, for the serum must be brought into contact with the infected membranes, and only a trace would reach the spinal fluid if the serum were injected subcutaneously or intravenously. The advantages of early administration are obvious, and if the symptoms are indefinite, the physician should not hesitate to perform lumbar puncture and to secure fluid for microscopic examination, just as he would take a throat or nose culture to aid in the diagnosis of diphtheria. The maximum, or at least an adequate, amount of serum should be injected, care being observed to avoid undue pressure as a result of injecting too quickly or too large an amount. This administration of antimeningitic serum is, therefore, an important and delicate, though relatively simple, procedure. 1. The technic of intraspinal injection has been described on p. 746. Whenever possible, the serum should be injected by the gravity method, and the amounts of fluid withdrawn and serum injected controlled by blood-pressure readings. 2. Lumbar puncture is performed, and the fluid collected in graduated tubes. In the ordinary case, fluid may be allowed to drain until the blood-pressure drops about 10 mm. of mercury, or if the pressure is unchanged or rises, until the fluid flows about one drop every three seconds, provided there are no other evidences of collapse, such as faintness, headache, and great restlessness. 3. As a rule, the amount of serum injected should be slightly less than the amount of fluid withdrawn. When the injection is controlled by the blood-pressure readings, — the amount varies considerably, — usually the injection should stop when the pressure falls another 10 or 15 mm. For adults, the dose of serum should be about 30 c.c.; for an infant, about 15 c.c. The serum should be allowed to flow in slowly, an ordinary injection consuming at least ten or fifteen minutes. If symptoms of collapse should appear before an adequate amount of serum has been injected, the funnel may be lowered and the spinal fluids allowed to flow out. When the symptoms have disappeared, the injections may be continued and satisfactorily completed. 3. When the physician cannot administer the serum by the gravity method or under blood-pressure control, the injection may be given by means of a syringe (see p. 752). It should be given slowly, and the patient observed closely in order to detect the general symptoms of collapse. The amount of serum injected should not be larger than the amount of cerebrospinal fluid withdrawn. According to Sophian, the average doses are as follows: 20 years and over 20 to 30 c.c. 40 c.c. The injection of too large a dose of serum may be followed by headache, pain in the back and legs, and restlessness. When the amount of serum injected exceeds the amount of spinal fluid withdrawn the symptoms just named must be regarded as the signal to stop; otherwise they may be disregarded. Intravenous Injection. — During epidemics of meningitis it may be possible to detect cases in the bacteremic stage when meningococci are present in the blood and clear fluid is collecting in the ventricles. In these and in all severe fulminant infections it is good practice to inject from 30 to 100 c.c. of serum intramuscularly or intravenously. It is advisable to secure a culture of blood in ascites dextrose broth in all cases in adults and older children. If sufficient serum may be obtained and the expense is a secondary consideration, an intravenous or intramuscular injection, given at the outset and once or twice during the acute stage, may benefit the patient by neutralizing toxins and possibly prevent complications due to the entrance of meningococci into the bloodstream. Furthermore, as shown by Flexner and Amos,1 in poliomyelitis the intraspinal injection of serum increases the permeability of the choroid plexus and meninges, permitting the passage of immunity principles from the blood into the cerebrospinal fluid. For this reason the intravenous or intramuscular injection of anti meningitis serum in conjunction with intraspinal injections may be particularly advantageous in the treatment of severe infections. Repeating Doses of Serum. — It is the general rule to give an intraspinal injection of serum every day for four days, and then on alternate days until the acute symptoms have subsided, and to resume the treatment if an exacerbation or a relapse occurs. In severe fulminant infections, and especially if the exudate is thick and only small amounts of serum can be introduced under pressure, it is well to repeat the injection every twelve hours until several doses have been given. Some cases require daily consecutive injections for six or more days; the average case will require from four to six injections if the treatment is begun during the acute stage; in the subacute and chronic cases many more treatments are required. There are two main indications and guides: 2. The clinical condition of the patient. 1. In most instances the cerebrospinal fluid tends to clear up macroscopically as the disease improves. This is, however, occasionally misleading, as the fluid may become more turbid as the result of an aseptic meningitis or excitation of a polynuclear leukocytosis- due to the serum, while in reality the numbers of meningococci are diminishing and the patient is improving. More accurate information is obtained by the microscopic examination of a stained smear of the sediment of the cerebrospinal fluid withdrawn. In fresh acute cases the cocci are numerous and mostly extracellular; improvement is indicated by a diminution in their number, and by the fact that they are mostly intracellular. I generally determine the phagocytic index or the relative proportion of leukocytes that have engulfed cocci and the opsonic index or the relative number of cocci per leukocyte as determined by counting a large number. When many cocci are present, or if they are few in number but mostly extracellular, the indications are to puncture next day, even if the clinical condition of the patient is good and the temperature is lower. The number and position of cocci are, therefore, of more importance as a guide to subsequent injections than is the total number of pus-cells. 2. As an indication for repeating the doses of serum the clinical condition is of most value when combined with the examination of the cerebrospinal fluid. Occasionally the patient's condition may seem to improve, although the fluid may show numerous cocci, which will subsequently aggravate the clinical condition unless the serum is administered. In favorable cases there is usually a lower temperature the day following an injection, and frequently delirium becomes less marked and there is some return to consciousness. The complexion, which is often cyanosed at first, regains a healthy color; the pain in the head, neck, and limbs becomes less severe, although the neck and spine may remain stiff for several days. Finally the mind becomes clear and the patient is cheerful, and no longer irritable, apathetic, and hypersensitive. He feels better and his appetite returns. When this favorable outcome supervenes, the serum injections may be discontinued, to be resumed, however, upon the first evidence of a relapse. The physician should be on his guard for the appearance of acute hydrocephalus, which condition is relieved by repeated lumbar puncture. The Serum Treatment of Cases with Thick Elastic Exudate. — In very severe cases the exudate may be so thick that it will not flow from the needle. In these cases the serum should be injected in small doses under pressure, and the injections repeated every eight to twelve hours. As they are likely in any case to terminate fatally, the physician is justified in taking the risk of increasing intracranial pressure. It may be well carefully to inject a small amount of warm sterile salt solution, which will dilute the exudate and possibly start a flow; or a second needle may be inserted higher up, when a' thinner exudate is found, or washing may be possible by injecting salt solution in the upper needle and draining through the lower. The Serum Treatment of Cases with a Dry Canal and Cases of Posterior Basal Meningitis. — Occasionally a patient improves clinically and the amount of cerebrospinal fluid becomes very scanty, the spinal tap being dry, although it is certain that the needle has entered the subarachnoid space. In such instances a small amount of serum may be injected, or the injection may be dispensed with if the clinical condition continues to improve. If, however, cases with dry canals present evidences of toxemia and general aggravation of symptoms, small doses of serum should be injected under pressure and the injections repeated as often as necessary. The physician must be very cautious, however, for if there are clinical evidences of severe intracranial pressure, it is probable that there is an encapsulation 'of fluid within the ventricles, and shutting off of the communication between the ventricles and the subarachnoid space. In this posterior basic meningitis intraspinal injections are dangerous and aggravate the process. In infants it is necessary to puncture the ventricles through the anterior fontanel and in older children and adults by trephining at Kocher's point, removing the fluid, and if it is found to be cloudy or purulent, injecting serum. It may be necessary to tap both ventricles alternately at intervals of several days, depending upon the reaccumulation of fluid and pressure symptoms. prognosis is very unfavorable. The Serum Treatment of Subacute and Chronic Meningitis. — If there is no evidence of sepsis; if the mind is clear and the neck limber; if the general conditions are good and the cerebrospinal fluid is practically cleared up, the affection is most likely hydrocephalitic, and may be relieved by repeated spinal punctures, with removal of as much fluid as is safe, using blood-pressure as an index. If meningococci are present in cultures of the fluid, small amounts of serum may be injected. The prognosis in these cases, however, is generally bad, as the process is prolonged and the patient finally succumbs. In the second form of chronic meningitis, when the meningeal symptoms are active, intensified, and persistent, serum should be administered every few days in the same manner and in the same dosage as in the acute cases. Improvement is, however, usually temporary, and the ultimate prognosis is very grave. Serum Sickness. — Intraspinal injections of serum result in the sensitization of the patient in just the same manner as if serum were injected by other routes. The percentage of cases developing serum sickness is likely to be high, since antimeningitic serum is not refined (Sophian reports 60 per cent, of his cases as developing the condition), and while the symptoms are distressing, they are seldom alarming, and fatal anaphylaxis is extremely rare. Occasionally the onset of serum sickness may be confusing, but if the meningeal condition has been responding as well as could be expected, it is wise to let the patient alone, rather than to make additional punctures and cause further depression. Local sedatives, laxatives, atropin, sedatives, and, at times, morphin, are indicated. Results of the Serum Treatment on Meningococcus Meningitis. — (a) Upon the Course of the Disease. — In the majority of cases the subdural injection of a potent antimeningitic serum is followed by some immediate improvement in the local suppurative meningitis and general sepsis, for the temperature usually drops, the mental condition improves, and delirium is diminished, although the Kernig sign may persist, partly as the result of meningeal irritation and partly on account of fear. Hydrocephalus is generally relieved, as indicated by lessening of the pressure symptoms, as, for example, severe headache, vertigo, and vomiting; breathing becomes more regular, and the pulse also becomes slower and more regular. The duration of the illness is usually shortened. According to Holt, in the New York epidemic of 1904-05, antedating the use of serum, among 350 cases that recovered the duration in 3 per cent, was one week or less, and in 50 per cent, five weeks or longer. Of 288 cases reported by Flexner and Jobling, the average duration of active symptoms in those receiving serum was eleven days. Sophian, in an experience of several hundred cases, reports that many acute cases were relieved in five or six days and discharged as cured in two weeks. (6) Upon Complications. — Next to its influence upon mortality, the good effects of antimeningitic serum are apparent in that it lessens the incidence and severity of the terrible complications of this disease. The most severe and permanent sequels are those resulting from affections of the internal ear and the essential structures of vision. A conservative estimate of the incidence of the former among cases not receiving serum treatment is 12 per cent. (Goffert), whereas Flexner's1 analysis of 1300 cases treated with serum shows that deafness occurred in but 3.5 per cent, of cases. At least from 12 to 24 per cent, of cases not receiving serum treatment will develop more or less serious eye complications, whereas Flexner's report shows that impairment of vision among serumtreated cases occurred in about 0.9 per cent, of cases. The latter report shows the occurrence of arthritis in but 0.9 per cent, of cases, whereas among cases untreated with serum this is a frequent complication. Whereas chronic meningitis is relatively common among cases treated without serum, it is uncommon among those treated with serum. (c) Upon Mortality. — The gross mortality among cases treated without serum varies from 70 to 90 per cent.; among serum-treated cases the mortality is about 30 per cent. For example, of 1294 cases treated with serum prepared in the Rockefeller Institute, the general mortality was 30.9 per cent. The influence of age upon mortality was early pointed out by Flexner. The very high mortality in infants and in old persons is due to their lowered vitality and enfeebled resistance. An additional factor in young children is their greater tendency to develop extreme hydrocephalus and convulsions. The statistics show indubitably that the mortality of epidemic meningitis can be greatly reduced by the administration of serum treatment. While the ordinary type of epidemic meningitis responds best to the specific treatment, the fulminant cases may also receive some of the beneficial influence of the serum. To quote from what Flexner wrote in 1909, and repeated in 1913: "In view of the various considerations presented, the conclusions may be drawn that the antimeningitis serum, when used by the subdural method of injection, in suitable doses and at proper intervals, is capable of reducing the period of illness; of preventing in large measure the chronic lesions and types of the infection, of bringing about complete restoration of health, thus lessening the serious, deforming, and permanent consequences of meningitis; and of greatly diminishing the fatalities due to the disease." Prophylactic Immunization in Meningococcus Meningitis. — In Chapter XXIX mention has been made of the probable value of active immunization against epidemic meningitis by the subcutaneous injections of three doses of a polyvalent meningococcus vaccine at intervals of a week. Sophian and others have shown experimentally that opsonins, bacteriolysins, agglutinins, and other antibodies are produced, and while meningococcus meningitis is ordinarily but mildly infectious (about 5 per cent, of secondary cases in homes), the method is practically devoid of danger and worthy of trial, especially for physicians, nurses, and members of a household who are exposed to the infection over a period of many weeks. Passive immunization by means of the subcutaneous injection of antimeningitic serum was advised by Jochmann in 1906, but has not come into general use. The immunity resulting from the injection of from 10 to 20 c.c. of serum is only temporary, and probably lasts about a month. Another drawback is the resulting serum sensitization, which renders subsequent injections of serum more likely to be followed by serum sickness. In the presence of an active epidemic, such as that which occurred in Texas during 1912, immediate passive immunization of physicians, nurses, and attendants by the subcutaneous injection of 15 c.c. of serum, followed by active immunization with three doses of vaccine (500, 1000, and 1000 millions) at intervals of a week, may be advisable. While there are no available statistics to prove the value of this procedure, it is, at least, a rational one, and since there is danger of contracting the disease, especially after prolonged contact, physicians should practise immunization during epidemics of this dreaded disease. In mixed passive and active immunization the serum probably affords immediate protection, and tides over any temporary negative phase or period of lowered resistance following the injections of vaccine. THE SERUM TREATMENT OF INFLUENZAL MENINGITIS Since lumbar puncture as an aid to the diagnosis of meningitis is coming into more general use, the important fact has been revealed that the influenza bacillus is not an infrequent cause of severe, and usually fatal, seropurulent cerebrospinal meningitis. In 1911 Wollstein1 collected 58 cases of this infection, all but 6 ending fatally, and as the bacterial diagnosis of meningitis is becoming more widely known and more commonly employed, the number of reported cases is increasing rapidly. The mortality of 90 per cent., which is exceeded only by the tuberculous and pneumococcus infections of the meninges, and the encouraging results following the use of a specific anti-influenzal serum in experimental infections in monkeys, render this subject one of great importance from the standpoint of serum therapy. among adults. Infection of the meninges is probably always secondary to infection of the respiratory tract with virulent influenza bacilli, the route of infection being chiefly through the blood-current. Direct infection from 1 Jour. Exper. Med., 1911, xiv, 73; Amer. Jour. Dis. Child., 1911, i, 42. the nose cannot be excluded, and should be considered a possibility. However, all or nearly all cases of spontaneous influenzal meningitis in human beings are the result of influenzal bacteremia, since the bacilli have been cultivated in large numbers from the heart's blood before and after death. The same is true of experimental influenzal meningitis in the monkey. According to Flexner,1 the cerebrospinal fluid removed by lumbar puncture from human patients is always turbid, and deposits a yellowish or whitish sediment on standing. "As the disease advances, the fluid becomes more heavily charged with pus-cells, until toward the end, and as late as the seventh day of illness, the puncture may yield merely a viscid mass of purulent matter. The number of influenza bacilli present in the fluid is usually large, and the bacilli lie chiefly extracellular, among the pus-cells, although a variable but small number is usually found ingested by the leukocytes. In morphology the bacilli vary somewhat, and in this respect the observer may readily be deceived as to the nature of the bacteria present. While some of the fluids contain the typical, minute rods, others show quite irregular and knobbed or even filamentous bacteria that have little resemblance to the influenza bacillus as seen in recent cultivations. These bizarre or involution forms, however, are met in old and exhausted cultures; and when they are recultivated on a suitable hemoglobin medium, they yield the typical minute rods." The cerebrospinal fluid removed from monkeys inoculated by subdural injection with virulent cultures of the influenzal bacillus resembles in all essential particulars the fluid removed from patients with spontaneous infections. The bacteriologic diagnosis can usually be made by microscopic examination of stained smears of the fluid, but whenever possible, the diagnosis should be confirmed by cultural methods. Anti-influenza Serum. — After having satisfactorily demonstrated experimental influenza meningitis in the monkey, Flexner and Wollstein prepared an immune serum and showed that the experimental infection could be controlled and cured by injecting the serum directly into the seat of disease by intraspinal inoculation. The immune serum was prepared by the ordinary methods, first a goat and then a horse being injected with non- virulent and finally with virulent bacilli, covering a period of many months, until their serums showed the presence of agglutinins and bacteriotropins. The serum lacked bacteriolytic prop1 Jour. Amer. Med. Assoc., 1913, Ixi, 1872. than 1 : 100. Following the administration of serum, the cerebrospinal fluid tends to clear up; the bacilli become fewer in number and are mostly ingested by the phagocytes; the pus-cells become less numerous, and while the bacilli may persist in the fluid for a longer period, they ultimately disappear. Administration of Anti-influenza Serum. — The Rockefeller Institute has distributed serum throughout different parts of the country, and is prepared to furnish it to physicians upon request. Physicians, and especially pediatrists, should resort to lumbar puncture early in all suspected cases of meningitis, for only in this manner may influenzal meningitis be detected early enough to derive any possible benefit from serum treatment. The serum should be injected directly into\ the spinal canal by the gravity or syringe method in exactly the same manner and with the same precautions as are observed in administering serum in the treatment of epidemic meningitis. Since the disease is usually accompanied by a bacteremia, it is well to inject serum intravenously, although serum injected intraspinally soon finds its way into the blood-stream. All data, including the clinical history and the records of bacteriologic examinations of cerebrospinal fluid and blood, the amounts of serum injected, and the results obtained, should be sent to the Director of the Rockefeller Institute. THE SERUM TREATMENT OF PNEUMOCOCCUS MENINGITIS Meningitis is caused more frequently by the pneumococcus than by the influenza bacillus. Its mortality is certainly no less than in influenzal meningitis. The few instances in which antipneumococcic serum has been employed have not yielded results that inspire confidence in its employment alone. As will be emphasized later, in considering the serum treatment of pneumonia, an antipneumococcus serum is at best active only against the homologous organism or organisms, the types of which have been employed in its preparation. Even when the homologous serum is used in treating experimental pneumococcus meningitis in monkeys, the fatal termination may be delayed, but is not prevented. For this reason the outlook for its successful employment alone in human infections is not encouraging. Recent investigations of Lamar1 have 1 Jour. Exper. Med., 1911, i; ibid., 380; xiv, 256; 1912, xvi, 581. shown, however, that mixtures of homologous antipneumococcus serum, sodium oleate, and boric acid exert a marked and decided curative influence upon a virulent experimental meningitis, and while this method has not thus far been generally applied in the treatment of the disease in humans, it is deserving of trial and offers considerable encouragement for an otherwise highly fatal infection. Pneumococcus Meningitis. — This infection is usually secondary, and follows on pneumonia or on inflammations of serous membranes by indirect transmission by the blood or by direct infection from the nasopharynx, mastoid cells, frontal, sphenoid and ethmoid sinuses, and internal ear. The diagnosis is usually made as the result of microscopic examination of stained smears of cerebrospinal fluid removed by lumbar puncture. Large numbers of polynuclear leukocytes with intracellular and extracellular Gram-positive diplococci, occurring in pairs or in short chains, usually indicate a pneumococcus infection. Whenever possible, the diagnosis should be confirmed by making cultures of the fluid on dextrose blood agar, and by injecting portions intraperitoneally and subcutaneously in mice. Pneumococcus infections of the cerebral meninges have been found experimentally to be more refractory to treatment than infections of the spinal meninges, hence human infections following injuries to the head, or occurring as the result of direct extension from neighboring sinuses, are likely to be more refractory than indirect infections by way of the blood. Serum Treatment. — Numerous investigations by Conradi,1 Korschun and Morgenroth,2 Levaditi,3 and Noguchi4 have shown that substances may be obtained directly from tissue-cells and leukocytes or after autolysis which are bactericidal and hemolytic, and, as shown by Noguchi, are largely in the nature of higher saturated fatty acids or their alkaline soaps. (For an account of their similarity to complements see Chapter XVIII.) As shown by Klotz,5 soaps occur in inflammatory foci, and the origin of the fatty acids and soaps is readily accounted for since Achaline6 has shown the presence of lipase in such foci. With the death of leukocytes in an inflammatory focus, brought about by a bacterial poison, leukocidins, or lack of nutriment, disintegration occurs, and by auto- seem to exert a destructive action upon the infecting bacteria. With these considerations in mind, Lamar investigated the influence of soaps upon pneumococci. Solutions of 0.5 to 1 per cent, of sodium oleate were found rapidly to kill pneumococci; much weaker solutions, as, e. g., 0.1 per cent., or even 1 part of soap in 10,000 parts of water, were found to lessen their virulence, and, what is more important and significant, to render the organisms peculiarly susceptible to lysis by a homologous antipneumococcus serum. A serious drawback to the application of these discoveries was that protein constituents of serum and exudates were found to inhibit the bacteriolytic and hemolytic action of unsaturated fatty acid soaps, as was shown by Noguchi l and then by von Liebermann.2 The latter and von Fenyvessy3 later found that this inhibition can be prevented in the test-tube and also in the animal body by adding a minute quantity of boric add, which prevents the union of soap and protein matter when the latter is not too greatly in excess. The experiments of Lamar with mixtures of homologous antipneumococcus serum, sodium oleate, and boric acid in the treatment of pneumococcus meningitis in the monkey have yielded excellent results, especially when used early in the infection. These experiments have proved that sodium oleate lowers the virulence of pneumococci and renders them peculiarly and highly susceptible to solution by bacteriolysins present in the serum, and that boric acid largely prevents the inhibitory action of protein constituents upon this sensitizing action of sodium oleate. Practical Applications. — One drawback to the use of this method in the treatment of human infections is the necessity of using an antipneumococcus serum corresponding to the organism causing the infection. In the Rockefeller Hospital a method has been worked out whereby the type of infection is quickly determined by agglutination reactions. Fortunately, the number of types of pneumococci are relatively few, and it is to be hoped that an efficient polyvalent serum will soon be made available by the Rockefeller Institute. Until this desideratum is attained, the commercial serums at present on the market may be used, with the addition of sodium oleate and boric acid. SERUM TREATMENT OF LOCALIZED PNEUMOCOCCUS INFECTIONS 807 The mixture should be injected into the spinal canal after the withdrawal of the fluid by the gravity or syringe method and under bloodpressure control, as previously described. The amount injected and the number of injections depend upon the clinical condition of the patient, and in general may be administered in the same way as is antimeningitic serum. Lamar has also suggested that mixtures of antipneumococcus serum, sodium oleate, and boric acid may be used in the treatment of pneumococcus pleuritis, peritonitis, or other localized infections, such as arthritis and sinusitis, where the exudate may be removed and the serum be brought into contact with the infected tissues. Acute lobar pneumonia, with its clear-cut clinical course, unsatisfactory and difficult treatment, uncertain prognosis, and high mortality, was one of the diseases in which the earliest efforts were directed toward discovering a specific serum therapy. Since the pioneer work of the Klemperers in 1891, numerous investigators have prepared serums that have yielded either indifferent results or proved beneficial in but a limited number of cases, so that there has been no well-established form of specific therapy. Recent investigations by Neuf eld and Handel 1 in Germany, and by Dochez,2 Cole,3 and Gillespie4 in the Rockefeller Institute, have disclosed several reasons for the failure of serum therapy in pneumonia, and have emphasized the importance of the following factors : possible. The investigators in the Rockefeller Institute have divided the pneumococci causing lobar pneumonia into four main groups, and have worked out a method for the rapid identification and classification of the particular pneumococcus that is the etiologic factor in a given infection, so that with the proper administration of the corresponding immune serum very encouraging results have been obtained in the serum treatment of pneumonia. These researches are of importance not only in this connection, but also from the fact that they may have disclosed the reasons for failure in the treatment of streptococcus and other infections, and that similar studies in these conditions may insure for serum therapy a definite and valuable role in the treatment of disease. The Nature of Lobar Pneumonia. — The frequency with which the Diplococcus pneumonia is found in the local lesion and in severe cases in the blood-stream of pneumonia patients, and the more recent experimental studies of Wadsworth,1 Meltzer,2 Wollstein and Meltzer,3 Winternitz, Kline and Hirschfelder,4 leave little doubt regarding the etiologic relationship of this microorganism to lobar pneumonia. Much still remains to be learned, however, regarding the method of infection and the nature of the resulting disease. While pneumococci are to be found living in the upper air-passages as harmless parasites, it is probable that those causing infection differ inherently as regards adaptation or virulence for man. In addition, it is likely that general resistance is lowered in some more or less peculiar manner, and experimental studies in animals, as well as the course of the disease in man, suggest most strongly that local changes in the respiratory tract may precede the infection, so that a combination of factors, such as the virulence of the organisms and the diminished general and local resistance, plays a part in the production of lobar pneumonia. In whatever manner produced, the disease is finally to be regarded as a general infection, with localization of the process in the lung. While pneumococci may be found in the blood of the most severe cases, the general symptoms are apparently due to intoxication with a poison or toxin derived primarily from the pneumococci, and secondarily from the exudate in the local lesions. The studies of Rowntree,1 Medigreceanu,2 and Peabody,3 showing chlorin retention; of Peabody,4 showing progressive loss in the oxygen-combining power of the hemoglobin, due to the formation of methemoglobin; of Medigreceanu,5 showing a deficiency of oxydase or lessened power of the tissues to carry on proper oxidation, and of Neufeld and Bold,6 Rosenow,7 Cole,8 Jobling and Strouse,9 indicating the presence of endotoxins within the pneumococci — all these support the view that in pneumonia there is well-marked intoxication, and this, in addition to the effects of the local pulmonary consolidation on the heart, respiration, and nervous system, constitute the main features of the infection. . Regarding the mechanism of recovery from pneumonia, there is little definite information. The recent studies of Neufeld, Dochez, and Clough indicate that antibodies are produced at or about the time of the crisis, and that these are probably responsible for the destruction of the bacteria in the circulating blood, and, to a greater extent, in the local lesion. In the resolution of the local lesion it is probable that ferments play an important part. That resolution does not occur earlier may be due to the overbalancing of the leukocytic ferments by the antiferments of the serum, and the lytic ferments become active only when they reach a point of excess over the antiferments, causing a solution of the fibrin, relieving tension, and affording an outlet for the exudate. According to Vaughan, the pneumococci may be considered as furnishing a ferment that brings about the production of a specific antiferment, capable of reacting upon its substratum, the ferment and the new bacterial tissue, and causing its destruction by a process of solution. Pneumococci in the resolving lesion are probably destroyed by leukocidins released through disintegration of leukocytes, by fatty acids, and probably by antibacterial substances in the blood. While it is true that immunity does not usually follow an attack of pneumonia, and, indeed, the patient is apparently hypersusceptible, it has been found experimentally that the antibodies are highly specific for the particular organism causing an infection. Reinfection is, therefore, possible with an organism belonging to another group, and lia- eral resistance due to the previous attack. Antipneumococcus Serum. — The indications of specific serum therapy, are, therefore, mainly twofold: first, to destroy any pneumococci present in the blood and in the local lesion; or if the latter is impossible because of mechanical obstacles that interfere with the circulation and prevent access of the antibodies to the cocci, to at least prevent extension of the lesion by preventing the multiplication of organisms at its margin; second, to neutralize the toxins produced during the course of the disease. It would, of course, be highly desirable to have at our command a serum that would cause solution of the local exudate and bring about a crisis and a cure. It is hardly reasonable to expect, however, that a serum can be produced that will contain digestants for fibrin and leukocytes. The local lesion is most likely to be harmful because of the toxic substances that emanate from it, and not because so large an area of lung is temporarily incapacitated and the heart embarrassed. A serum that will prevent general bacteremia, limit the extension of the local lesion, and neutralize the toxins while nature is preparing to react upon the exudate with a ferment, is probably fulfilling all that may be expected of a specific serum therapy. Groups of Pneumococci. — Neufeld and Handel have shown that an immune serum produced by the injection of a given variety of pneumococci into an animal was not effective against all forms of pneumococci. In the Rockefeller Hospital a serum, known as Serum 1, prepared by immunizing a horse with a culture obtained from Neufeld, was found to protect against only about one-half the types of pneumococci (Group 1) studied. By immunizing rabbits to each of the types that were not acted upon by Serum 1, and testing the immune serum against all strains by cross-agglutination and by cross-protection experiments, it was found that a number of the serums possessed the same properties, thus indicating that their respective cultures belonged to the same general group (Group 2). By immunizing a horse with one of these, Serum 2 was produced. In Group 3 are placed all the organisms of the so-called Pneumococcus mucosus type. In Group 4 are included all the varieties of pneumococci against which Serums 1 and 2 are not effective, and which, from their other properties, do not belong in Group 3. Animals may readily be immunized to any member of this Group 4, and the serum of the immunized animal is protective against the strain used for immunization, but in no instance has this serum been found effective against any other member of this group or against the organisms of the other groups. While no cultural or morphologic differences between the members of Group 1, 2, and 4 exist, it has been found possible to group them by the agglutination reaction in exactly the same manner as by protection experiments. Of 24 strains studied in the Rockefeller Hospital, 47 per cent, belonged to Group 1, 18 per cent, to Group 2, 13 per cent, to Group 3, and 22 per cent, to Group 4. possess some antitoxic value, it is desirable that the animals be immunized also with autolysates. The whole process may be conducted after the method described for the production of antimeningococcus serum. In the Rockefeller Institute different horses are immunized with strains belonging to Groups 1 and 2. It would appear possible to produce a potent polyvalent serum, and this is very much to be desired, especially if further studies continue to show that 65 per cent, of infections are caused by organisms belonging to these two groups. Kolle, by immunizing horses with cultures secured from pneumonia patients, produces an antipneumococcic serum. These cultures are grown in broth for fortyeight hours, heated to 60° C., and 5 c.c. injected intravenously into a horse. The dose is increased each week until 120 c.c. are given at one time. Then 5 c.c. of living culture is injected, and the doses increased in a similar manner until 120 c.c. are given at one time. About six months are consumed in the process of immunization, and two weeks after the last injection has been given the serum is tested. Concentration of Antipneumococcus Serum. — In view of the large doses of serum required in the treatment of lobar pneumonia and the possible injurious effects of the large amount of horse-serum protein injected, Gay and Chickering1 and Chickering2 have endeavored to concentrate the immune serum by adding relatively small amounts of the extract of pneumococcus and recovering the resulting precipitate. These precipitates have been found to contain practically all the protective antibodies of the original serum and relatively small amounts of protein as compared with the original serum. Standardization of Antipneumococcus Serum. — As previously mentioned, there is at present no accurate method for standardizing an antibacterial serum. It is possible, however, to obtain some measure of its protective and curative power by employing various tests. 1. Protective Value. — The lethal dose of a living pneumococcus culture for mice is determined, and from 10 to 100 times this amount of culture is mixed with decreasing doses of immune serum and the mixtures injected subcutaneously or intraperitoneally into a series of mice in order to determine the dose of serum that will protect. Dochez has found that when these mixtures are injected at once and in the same place, the serum will obey the law of multiple proportions up to a certain limit. Merck's antipneumococcus serum is so standardized that 0.01 c.c. injected subcutaneously protects a mouse inoculated intraperitoneally twenty-four hours later with from 10 to 100 times the lethal dose of a living virulent culture. This is known as a normal serum, 1 c.c. containing an immunity unit (I. U.). The serum is marketed in vials containing from 20 to 40 c.c. Kolle regards as satisfactory a serum that, in doses of 0.001 c.c. and less, will protect mice. technic of this titration has been described elsewhere. 3. Complement- fixation and Agglutination Tests. — While these tests are frequently sharply cut, and while they serve as a measure for record in the laboratory, they do not necessarily indicate the therapeutic value of the serum. Action of Antipneumococcus Serum. — The curative and protective value of this serum depend mainly upon bacteriolysins, bacteriotropins, and antitoxins. The first are readily demonstrated in protection experiments and also in pneumonic patients when pneumococci in the blood-stream are destroyed. Bacteriotropins may likewise be demonstrated experimentally and in the blood of patients if the corresponding organism is used in the tests (Neufeld, Strouse). The antitoxic properties are shown clinically and also in vitro by neutralization of the hemotoxic poison obtained by dissolving pneumococci in bile. As shown recently by Bull,1 the agglutinins in the serum may play a very active role by producing an agglutination of the cocci in the blood-stream followed by phagocjrtosis. Administration of Antipneumococcus Serum. — To obtain the best results the serum should be given as early as possible and intravenously. In young children, when the giving of an intravenous injection is quite difficult or impossible, the muscles of the buttocks should be substituted. Certainly small doses given subcutaneously are almost devoid of effect. The procedure in use in the Rockefeller Institute consists in injecting 0.5 c.c. of serum subcutaneously to discover if hypersensitiveness exists and to produce anti-anaphylaxis. As soon as the type of organism has been determined (see page 308), from 50 to 100 c.c. of the serum, diluted one-half with salt solution, are injected intravenously. The condition of the patient serves as a guide in the later treatment. Usually the serum is not administered oftener than once every twelve hours. It has been shown experimentally that, in the presence of a maximum degree of infection, no amount of serum, however large, is effective. This suggests that the body must furnish a second substance to act with the antibodies in the serum, and indicates the early administration of serum before the infection has reached too extreme a grade. I would also suggest that the body may be deficient in bacteriolytic complements, and that the effect of a serum may be enhanced by adding fresh sterile guinea-pig serum — say 5 c.c. to each 100 c.c. of immune serum — just prior to administration. Results in the Serum Treatment of Pneumonia. — It is hardly necessary to review the numerous reports that have been made in past years, because in most instances the serum was administered subcutaneously and in too small doses to be of value, even granting that it contained antibodies for the particular infection. Of 23 patients, all seriously ill, treated in the Rockefeller Institute during the past year, the results were as follows: Of 15 cases due to pneumococcus 1, all recovered but one — a mortality of 6.6. per cent., as compared with the mortality of 24 per cent, among 34 patients not receiving serum treatment; of 8 cases due to Type 2, all recovered but two, one of these refusing to continue the treatment — a mortality of 25 per cent, as compared to 61 per cent, among 13 patients not receiving serum. More recent reports indicate that the percentage of predominating types of pneumococci 1 Jour. Exper. Med., 1915, 22, 466. results indicated. Aside from this decided influence upon mortality, the general effects of the serum were good. In 10 cases pneumococci were isolated from the blood before the treatment was begun. In all these patients the blood had become sterile after the first treatment. Following the injection of serum all the patients seemed to feel better, and in a number of them there was an apparent lessening in the degree of intoxication. While in no case was one injection sufficient to bring about a crisis, in all except the fatal cases the serum had apparently an ultimate favorable effect, lowering the temperature and shortening the course of the disease. THE SERUM TREATMENT OF STREPTOCOCCUS INFECTIONS The acute character of streptococcus infections and their relative frequency and severity have made them the subject of numerous efforts on the part of various investigators toward developing an efficient serum therapy. To Marmorek belongs the credit of first attempting, in 1895, to prepare a curative serum on a large scale. Since then Aronson, Tavel, Krumbein, Moser, Meyer-Ruppel, Menzer, and others have prepared immune serums with various cultures and according to various methods. While many antistreptococcus serums will show undoubted protective value, especially against their homologous cultures as tested in experimental animals, the general opinion regarding their curative value in streptococcus infections of man have been conflictmg and as a rule unfavorable. Occasionally the rapid improvement of a patient following an injection of the serum would indicate that it has proved beneficial, and the same is occasionally true of a particular group of infections treated with a specially prepared serum. The tendency oi acute streptococcus infections to end spontaneously by crisis must, however, be borne in mind, and the good result observed in individual cases may be coincident with, rather than the result of, the administration of the serum. ^XT Several causes for the failure of antistreptococcus serum therapy are now understood, and if these can be eliminated, the value of this form of therapy will be greatly augmented. 1. The serum should be given in large doses, and by intramuscular and intravenous injection. In a true streptococcic infection the cocci are likely at some time to be found in the blood-stream, and an attempt to destroy these organisms or to limit a local infection by injecting 10 c.c. of serum in the subcutaneous tissues is almost sure to result in failure. As in the serum treatment of pneumonia, at least 100 c.c. of serum should be given intravenously and the dose repeated if necessary. 2. The serum should be used as early in the disease as possible, instead of waiting until the patient has become moribund. In puerperal sepsis and scarlet fever, for instance, the question of serum therapy should be considered early, for when properly administered, the serum will at least do no harm and may prove efficacious. In order to determine the value of the serum a bacteriologic diagnosis should always be attempted, especially by means of blood cultures obtained by placing from 2 to 5 c.c. of blood in a flask containing at least 100 c.c. of dextrose broth just prior to injecting the serum. 3. The serum should be polyvalent. Marmorek maintains that all streptococci are alike, and he has, accordingly, prepared his serum from a single highly virulent strain. Other investigators question this assertion, and at present the consensus of opinion is agreed that streptococci from different infections, such as puerperal sepsis, scarlet fever, ulcerative endocarditis, and erysipelas, exhibit certain immunologic differences, even though their biologic and morphologic characters are quite similar. Thus far no adequate methods for differentiating between these organisms have been discovered, but it is likely that future researches will show that streptococci from different infections, and even from cases of scarlet fever, possess different immunologic characters similar to the variations observed among the pneumococci causing lobar pneumonia. If this is found to be true, under these conditions, a similar serum treatment, while complicated, is likely to prove valuable in the treatment of streptococcus infection. For the treatment of streptococcus infection in scarlet fever the serum should be prepared of numerous strains isolated from patients having this disease. What has just been said is also true of the other three infections so frequently streptococcal, namely, puerperal sepsis, phlegmonous cellulitis, and ulcerative endocarditis. If not these four, at least two antistreptococcus serums should be available : one for scarlet fever and the other for other infections; both, and especially the latter, should be prepared by immunizing horses with a large number of various strains. Mode of Action of Antistreptococcus Serum. — Virulent streptococci exert a powerful negative chemotactic influence upon leukocytes, repelling them and effectively resisting phagocytosis for varying periods of time. The early researches of Bordet showed that antistreptococcus serum neutralizes this influence and promotes phagocytosis. Since then numerous investigators have supported Bordet's findings, so that it may be accepted as true that one of the chief antibodies in antistreptococcic serum is of the nature of a bacteriotropin or immune opsonin. A potent serum also contains an antitoxin, as may be shown experimentally by neutralization of the hemotoxic poison of streptococci, and also clinically, when the rapid subsidence of fever and general improvement of the patient are probably due, in part, to neutralization of streptococcal toxins. Thus far the presence of bacteriolysins has not been definitely proved, although they may be present and operative in vivo. I have found that antistreptococcus serum contains an antibody capable of fixing complement with streptococcus antigens.1 It may be stated, therefore, that the action of antistreptococcus serum is dependent primarily upon bacteriotropins, and secondarily upon antitoxins and, possibly, bacteriolysins. Preparation of Antistreptococcus Serum. — Some differences of opinion have been expressed regarding the advisability of passing cultures that are being used for purposes of immunization through a lower animal in order to increase their virulence. For example, the unsatisfactory results that have followed the use of Marmorek's serum have been ascribed not only to the fact that it is monovalent, but also to possible alteration of the strain in its biologic characteristics by animal passage, so that its virulence for the human being was diminished or lost, and, accordingly, while the antiserum is protective for the animals through which the passage has been conducted, it is inactive for the human being. Tavel, Krumbein, and Paltauf have prepared polyvalent serums with different strains from human infections without animal passage. Menzer has prepared a serum with strains of cocci derived from acute rheumatic fever, and Moser with strains obtained from scarlet fever, which have also not been passed through animals. Aronson has attempted a combined procedure, making use of passed and unpassed cultures conjointly, and this appears to be the method of choice. In other words, those who prepare antistreptococcus serums should use as many fresh strains as possible, and hi several of the older cultures the virulence should be increased from time to time by passage through animals. In preparing the serum young and healthy horses should be used. The injections should first commence of dead cultures given subcutaneously, then of autolysates, and finally of living cultures administered intravenously. Occasionally severe local and general reactions are observed, and the whole procedure should be conducted under careful supervision. First Method. — Cultures are grown on a solid medium, and an emulsion and autolysate prepared as described for immunizing with meningococci. Begin by injecting subcutaneously 5 c.c. of emulsion heated to 60° C. for an hour, and increasing the dose each week by 5 c.c. until 100 c.c. are given at one time. If the reactions are mild (general and local), the doses may be increased more rapidly. Then begin with 2 c.c. of living culture and increase the dose each week. When a dose of 10 c.c. is reached, inject with autolysate and living cultures alternately, gradually increasing the dose until a dose of 50 c.c. is reached. Living cultures are then given intravenously and the dose rapidly increased until 100 c.c. and more are given at one time. Intravenous injections are not infrequently tolerated better than subcutaneous injections. The horses may be bled several times" during the course of immunization and their serums tested. When the serum is to be used therapeutically, the animals should not be bled in less than from ten to fourteen days after the last injection was given. In view of the large doses required, a concentrated serum is advisable (Heinemann and Gatewood1)- Since trikresol has an inhibiting influence on phagocytosis (Weaver and Tunnicliff2), the minimal quantity (0.2 per cent, or less) should be used, or preferably no preservative at all. Second Method. — Kolle prepares a polyvalent serum with cultures derived from cases of erysipelas, puerperal sepsis, scarlet fever, etc. Their virulence is increased from time to time by passage through rabbits. Horses are used for immunization purposes and all injections are given intravenously at intervals of a week. Cultures are grown on test-tubes containing a solid medium, and immunization is started with half a culture, heated. The dose is increased each week with an additional culture until it equals 16 cultures. Then living and killed cultures are mixed, giving in one week 2 living and 14 killed cultures and so on until 10 living and 6 killed cultures are given at a single dose. The horses are bled two weeks after the last dose is administered. Standardization of Antistreptococcus Serum. — There is at.. present no single satisfactory method for standardizing these serums, although a satisfactory method is a desideratum for testing serums placed on the market. In order to obtain an approximate idea as to the value of a serum, the following tests may be employed: 1. Protective Value. — At the Serum Institute in Vienna a passed culture (one used in the process of immunization) is selected, and that dose which will kill a mouse at the expiration of or just preceding the end of four days is regarded as a single lethal dose. In testing an antiserum 10 times this quantity of culture is used with decreasing doses of immune serum injected twenty-four hours previously or simultaneously. A normal serum is one of which 0.01 c.c. will afford protection, and 1 c.c. of such a serum is said to be one immunity unit, i. e., it affords protection against 1000 lethal doses of culture. 2. Bacteriotropic Value. — The technic of Wright or Neufeld may be employed with a virulent culture and human leukocytes. Weaver and Tunnicliff have observed better results when using one part of immune serum reactivated with nine parts of fresh guinea-pig serum. some of its protective value, and much of it on the market is worthless. Administration of Antistreptococcus Serum. — It must be emphasized here that, in order to obtain the best results, antistreptococcus serum must be given intravenously. In an adult patient with a severe general infection from 30 to 100 c.c. of serum, diluted with an equal amount of sterile normal salt solution, may be given in one dose,. If improvement follows, subsequent doses should be given subcutaneously or intramuscularly in order to prolong the action of the serum. If no improvement follows in from twelve to twenty-four hours, or if an acute exacerbation sets in, a second dose should be given intravenously. Since the various manu1 Jour. Infect. Diseases, 1912, x, No. 3. 2 Jour. Infect. Diseases, 1911, ix, 130. facturers use different cultures in the preparation of these serums, it would be well to use a different brand of serum if the first does not exert a beneficial effect. In patients with sever^ infections the activity of the serum may be enhanced by adding, just tiefore injection, 5 c.c. of fresh sterile guinea-pig serum to each 50 c.c. of the immune serum. In the treatment of localized streptococcus infections, such as meningitis and sinusitis, it may be well to mix antistreptococcus serum with sodium oleate and boric acid, as previously described. Value of Antistreptococcus Serum. — Although the serum has been in use for almost twenty years, the true exact value of the remedy has not as yet been estimated. It may be stated that a carefully prepared and properly administered serum will do no harm and may do good, and that its use should form a part of the treatment of severe streptococcal infections. In some cases of wound infections with severe cellulitis and septicemia the serum may at times exert a most pronounced and happy effect. In other cases, and especially in those in whom the cocci are found in the blood, repeated injections may be of no value. In severe anginose or malignant scarlet fever large doses of serum from horses especially immunized with strains of streptococci from scarlet-fever patients have, on the whole, yielded favorable results. Not all cases of severe scarlet fever, however, are due to secondary streptococcal infections : those patients who are overwhelmed and prostrated at the very outset are probably intoxicated with the true scarlatinal virus, whatever that may be, and such cases are not likely to be benefited by serum treatment. The patients most likely to improve under serum therapy are those who become severely ill after the onset of the disease and the appearance of the eruption. In puerperal sepsis and endocarditis of streptococcal origin the results of serum treatment have not been uniform, but are generally unfavorable. If serum is administered at all, it should be given early, in large doses, and intravenously. Not all cases of puerperal sepsis are streptococcic, and while the physician may not be justified in withholding serum until a bacteriologic diagnosis has been made, this factor must be considered when estimating the value of a serum. In erysipelas the results of serum treatment have been very indifferent, but may at times prove beneficial in severe cases when administered in large doses, and the same may be said of bronchopneumonia, laryngeal diphtheria, small-pox, and tuberculosis. THE SERUM TREATMENT OF GONOCOCCAL INFECTIONS In 1906 Torrey and Rogers1 described the preparation of an antigonococcus serum and advocated its use in the treatment of gonococcal infections, and especially of its various complications and metastases. In the following year these observers reported2 favorably upon the results of serum treatment in gonorrheal arthritis, and to a lesser extent in infections of the genito-urinary organs. Uhle and Mackinney3 used the serum in the treatment of 23 cases of gonococcal infection, and found it beneficial in three cases of gonorrheal arthritis and in one of myositis, whereas in epididymitis and urethritis no appreciable effects were observed. Herbst and Belfield,4 Schmidt,5 and Swinburne 6 agree as to the value of the serum in gonorrheal arthritis, whereas in other complications they secured somewhat conflicting results. In all instances the serum was used in relatively small doses, namely, 2 c.c., injected subcutaneously each day or every other day, the number of injections depending on the clinical condition of the patient. Recently Corbus 7 has reported more favorable results in the treat- • ment of 24 cases of gonococcus infection by using larger doses of serum — from 36 to 45 c.c. — injected intramuscularly. This observer advocates the use of the complement-fixation test as a reliable guide to the administration of the serum : the more intense the reaction, the more efficient will the serum prove; if the reaction is negative, the serum should not be used. 3. In those acute infections arising by direct extension from the urethra, such as acute prostatitis and epididymitis; acute orchitis and probably cystitis in the male; and acute salpingitis in the female. The serum has not proved of value in the treatment of gonorrheal conjunctivitis, although it would appear advisable to employ it in large doses administered intravenously or intramuscularly. Preparation pf Antigonococcus Serum. — Torrey's serum is prepared by immunizing rams with gradually increasing intraperitoneal doses of dead, and later of living, cultures of gonococci. Larger amounts of serum may be secured by immunizing horses according to the methods described for the preparation of meningococcus and streptococcus immune serums, and in view of the larger doses now advocated, this is advisable. This serum has been successfully concentrated in the same manner as is diphtheria antitoxin. Mode of Action of Antigonococcus Serum. — According to Torrey, this serum is largely bacteriolytic in nature. The presence of antitoxins has not been demonstrated; small amounts of bacteriotropins are present, so that a potent serum probably destroys the cocci by extracellular lysis and phagocytosis. Administration of Antigonococcus Serum. — The amount of serum used and the method of inoculation are very important factors in the success or failure of the treatment. If the serum is used at all, it should be given in large doses. The original method of giving 2 c.c. subcutaneously has been found inadequate in most instances. In acute gonococcal metastases in the joints or in the endocardium or other serous membrane, from 30 to 50 c.c of serum should be injected intravenously, or at least intramuscularly. When gonococci are found in the blood, or when the patient is profoundly septic, from 50 to 100 c.c. of serum should be given intravenously. In epididymitis, orchitis, and other local complications from 30. to 50 c.c. of serum should be given intramuscularly or intravenously. Other forms of treatment should be instituted simultaneously. If necessary, the serum injections should be repeated in twenty-four hours, and if a good primary effect follows an intravenous injection, it may be prolonged by one or more subcutaneous or intramuscular injections on subsequent days While several attempts have been made to treat staphylococcus infections with an immune serum, the investigations have been too few and too brief to warrant a statement in regard to the value of serum therapy in these infections. Thomas 1 prepared a serum by immunizing a ram with 18 different strains of Staphylococcus pyogenes aureus, and reported good results in the treatment of 28 cases of furunculosis and carbuncles. It is probable that, with more extensive use of antistaphylococcus serum, its value will be proved, especially in the treatment of severe 1 Jour. Amer. Med. Assoc., 1913, Ix, 1070. furunculosis of infants as well as of adults, when the low general vitality of the patient contraindicates the use of a bacterial vaccine. With extended use it may also be found to be of benefit in staphylococcus bacteremia, osteomyelitis, arthritis, carbuncle, and other severe infections. Following recovery or relief from an acute infection it would seem to be wise actively to immunize the patient with a vaccine, or serum and vaccine may be used conjointly. The activity of the serum is probably largely dependent upon the presence of bacteriotropins and antitoxins, the former promoting phagocytosis and the latter neutralizing the staphylolysins or hemotoxic poisons produced by staphylococci. Sclavo,1 Mendez,2 and Deutsch3 have prepared anti-anthrax serums by immunizing sheep, goats, asses, and horses with virulent cultures of anthrax bacilli. In the treatment of human infections, only Sclavo's serum has been used, the others being used in the treatment of anthrax among the lower animals. An anthrax serum prepared by American manufacturers is also on the market. Sclavo's serum has been shown to possess protective and therapeutic properties in experimental infections, and favorable results have been recorded in cases of human anthrax. According to Sclavo's statistics, the serum has reduced the average mortality of anthrax from 24 per cent, to 5.3 per cent. Cigognani, Legge, Lockwood and Andrewes, Stretton and Mitchell, and others have reported favorably as to the value of the serum. It is somewhat difficult to prepare a potent serum, and horses should be immunized with a large number of strains from human infections over a long period of time. The serum is probably largely bacteriotropic and bacteriolytic in nature. Administration of Anti-anthrax Serum. — In the Philadelphia Hospital for Contagious Diseases a number of anthrax cases are treated every year. Whenever blood-cultures have revealed the presence of the bacilli in the circulation, the patient has usually succumbed to the disease in spite of serum treatment; the doses employed — 10 to 20 c.c. — may, however, have been too small. I would recommend the following course of treatment in these cases : 1. If the lesion is relatively small and accompanied by but slight glandular involvement, with little or no evidences of toxemia, a blood culture should first be made by placing from 2 to 5 c.c. of blood in a flask of neutral bouillon, followed by an intravenous or intramuscular injection of from 20 to 50 c.c. of serum. The object sought is to introduce serum before the lesion is handled, and the blood culture is the best indication for subsequent injections of serum and serves as a guide to prognosis 2. The lesion should then be excised, leaving a wide margin so as to include infected lymphatic channels. It should be handled as little as possible. The wound is then dusted lightly with powdered calomel and next heavily powdered with ipecac. Edema soon subsides, and the wound usually heals rapidly, with surprisingly little scar-tissue formation. If the edema does not subside and the infection is spreading at the margins of the wound, more tissue should be excised or multiple local injections with phenol and anti-anthrax serum should be made. 3. The blood culture may be examined within twenty-four hours. If anthrax bacilli are present, from 100 to 200 c.c. of serum should be given intravenously, the injection being repeated in twenty-four hours. Daily blood cultures should be made, and the serum injections continued until the blood becomes sterile. Salvarsan may also be injected intravenously. In our experience, cases with sterile blood cultures have invariably recovered. large scale in the treatment of typhoid fever in man. The serum is derived from horses that have been immunized for several years with bouillon filtrates containing typhoid toxin, chiefly endotoxin, and with typhoid bacilli. Kraus and von Stenitzer, Meyer, Bergell, and Aronson use bouillon filtrates and aqueous bacterial extracts; Besredka injects dead and then living cultures; MacFadyen uses an endotoxin secured by breaking up cultures frozen at very low temperature. It would appear that a serum should be bacteriolytic and endotoxic, and this probably is best secured by prolonged intravenous immunization of horses with a large number of dead cultures and then with autolysates and living cultures conjointly. of his serum produces leukocytosis and raises the opsonic index of the patient's serum. He emphasizes the fact that the serum should be given early, — before the seventh day, — and reports that, by its use, the mortality has been reduced from 17 per cent, to 4.3 per cent. These results have not been generally confirmed, and the subject is still sub judice. Of the various antipest serums that have been prepared, that of Yersin is probably best known. This serum, it would appear, possesses some prophylactic and therapeutic value. For purposes of prophylaxis from 10 to 20 c.c. of serum may be injected subcutaneously or intravenously; the period of protection is short, averaging from ten to fourteen days. Combined active and passive immunization, effected by means of injections of a pest vaccine and an antipest serum, will probably exert a protective action of several months' duration, and should be used by physicians, nurses, and others during epidemics of plague. When used for therapeutic purposes, the results have been quite variable. If serum is used in the treatment of plague, it should be given as early as possible, in the form of intravenous or intramuscular injections of from 50 to 150 c.c., if this amount 'is available. Injections should be continued at twelve- to twenty-four-hour intervals for two or more days until suppuration has been controlled and the disease shows signs of abating. The Plague Commission of India1 has not issued very favorable reports upon the use of either this serum or that of Lustig. Chosksy,2 who has had the most extensive experience with the serum treatment of plague, emphasizes the necessity of treating the patient on the first day. He advises giving 100 c.c. of serum, followed by a second and third dose at intervals of six to eight hours. This treatment usually cut short the attack if the case were not pneumonic, malignant, or septicemic. Of 400 cases treated with serum the mortality was 63.5 per cent., while in 200 controls the mortality was 74 per cent. The mortality among cases treated with serum on the first day was 30 per cent. ; on the second day, 52 per cent., with a gradual increase in the mortality until on the seventh day the mortality was 100 per cent. Burnett3 has reported a mortality of 29.7 per cent, among cases treated with serum as against a mortality of 73.9 per cent, treated without serum. In the treatment of pneumonic plague the serum has given no favorable results. (a) In addition to Yersin's serum, which is prepared at the Pasteur Institute of Paris by immunizing horses with dead and then with living cultures of pest bacilli, other serums have been prepared. For example: (6) Kolle immunizes horses with intravenous injections of heat-killed cultures, beginning with Y± agar slant culture and doubling the dose each week until 15 cultures are given at one time. The horses are bled fourteen days after the last dose is given. (c) Lustig immunizes horses with pest-nucleoproteins, obtained by breaking up the bacilli with 1 per cent, of potassium hydroxid and precipitating the proteins with acetic acid. These are then suspended in sterile normal salt solution, as in the preparation of Lustig's vaccine. believes that the value of pest serum is largely dependent upon antitoxins. The serums are usually tested by injecting mice with lethal doses of pest culture and decreasing doses of antiserum. The agglutinin content may also be measured. According to Strong pest immune sera do not contain appreciable amounts of bacteriolysin, but are largely bacteriotropic in action. Whenever cultures are used in immunization, the serum should always be cultured carefully and tested by animal inoculation to guard against the possibility of living bacilli being present. In some respects cholera would seem to oe due mainly to a toxin elaborated by the bacilli in the intestinal tract of infected persons, similar to the action of the toxin of the Kruse-Shiga type of dysentery bacillus. Various attempts have been made to prepare an efficient anticholera serum, but the only one that has yielded encouraging results in experimental infections as well as in cholera of human beings is that prepared by Kraus. This serum is prepared by immunizing horses with a true toxin derived from a cholera-like vibrio isolated by Gottschlich from the intestinal contents of pilgrims dying at El Tor from a dysentery or cholera-like infection. According to Kraus, this antiserum is largely antitoxic, and serves to neutralize the toxin of true cholera more effectively than does the antiserum resulting from immunization with cholera cultures. A serum that is antitoxic and is obtained by prolonged immunization of horses by intravenous injections with dead cultures of cholera, and later with living cultures, bacterial extracts, and nitrates of old bouillon cultures conjointly, would seem to be a desideratum. jections of 140 c.c. of serum with 500 to 700 c.c. of sterile salt solution, followed by a similar or slightly lower dosage in from six to twenty-four hours after the first dose. Twelve patients were treated in this way with Kraus' serum with a mortality of 25 per cent., as compared with a general mortality of 75 per cent, in cases receiving no serum. The report of Hundogger1 upon the use of this serum is unfavorable. A thorough review of the literature and personal investigations of Strong will be found in these papers.2 The intravenous administration of salt solution alone has proved of value in the treatment of cholera, and it is reasonable to assume that a potent serum may be of service by neutralizing toxins, destroying the bacilli, and at least furnishing additional fluids for the depleted tissues and circulation. There are no available statistics as regards the prophylactic value of anticholera serum, but combined active and passive immunization by means of a subcutaneous injection of from 10 to 20 c.c. of serum, followed by three doses of vaccine, would appear to be a rational procedure in the presence of an epidemic or of a threatened epidemic of cholera. While numerous efforts have been made to prepare an efficient antituberculosis serum, only two — those of Maragliano and Marmorek — have been studied and are familiar. Maragliano's serum is prepared by immunizing horses for from four to six months with a mixture of a toxin prepared by the filtration of cultures only a few days old and concentrated in vacuo at a temperature of 30° C., mixed with that obtained by aqueous extraction of killed virulent cultures and concentrated by heating on a water-bath at 100° C. for three or four days. Maragliano assumes that the antiserum possesses antitoxic, bactericidal, and agglutinating properties. One cubic centimeter of this serum is injected every other day for one and a half months. The favorable action of the serum is reported on, especially by Mircoli and other Italian physicians, but in Germany and France proof of its value could not be established. Marmorek's serum is now prepared by immunization of horses with young tubercle bacilli, whose acid-fast character is still very slight or entirely absent. When the horses have attained a high degree of immunity, they receive injections of various strains of pure cultures of strep- THE TREATMENT OF INFECTIOUS DISEASES 825 tococci obtained from the sputum of tuberculous patients. The serum of these animals is, therefore, antituberculous and also antistreptococcic, and is serviceable against a mixed infection. The serum is administered daily, either by subcutaneous injection, in doses of from 5 to 10 c.c., or by the rectum in doses of from 10 to 20 c.c. The latter form of administration is quite objectionable to most patients, but is the one least likely to produce serum sickness. While this serum has been used quite extensively, the evidence at present is too conflicting to permit definite conclusions to be drawn as to its value in treatment. It would, however, seem to be worthy of further trial in cases of localized bone and joint tuberculosis and in the incipient stage of pulmonary tuberculosis. Citron recommends its use in patients who evince persistent rise of temperature, and in the very severe but not hopeless cases where tuberculin therapy cannot be undertaken. In some of these cases he has obtained very encouraging results. Citron occasionally begins with the serum treatment, and later combines tuberculin administration with it, finally omitting the serum altogether. SERUM OF CONVALESCENTS AND WITH NORMAL SERUM On the basis that recovery from several of the infectious diseases confers a high degree of immunity due presumably to the presence of specific antibodies in the body fluids and particularly the blood, numerous attempts have been made to treat certain of the infectious diseases, and particularly those for which we do not have an artificially prepared serum, with serum derived from convalescents. Scarlet Fever. — Huber and Blumenthal,1 von Leyden,2 Reiss and Jungman,3 Koch,4 Rowe,5 Zingher,6 and others have reported favorably upon the treatment of scarlet fever and particularly severe infections, with injections of serum from persons who have recovered from this disease. Reiss and Jungman obtained the serum from persons about the third week of the disease and injected 50 to 100 c.c. intravenously. Koch emphasizes the necessity of starting the treatment as early in the disease as possible and injecting large doses of the serum intravenously. Rowe was unable to convince himself that there were any different effects in cases treated with normal and with convalescent serum; Koch also suggests that the convalescent serum be reserved for the gravest cases, and that otherwise normal human serum be used. Zingher has used intramuscular injections of whole citrated blood, administering from 2 to 8 ounces in a series of injections at close intervals. Normal human blood was also found of value in the treatment of a group of later septic cases, seen from the fifth to the eighth day of the disease. It is apparent that these methods of treatment are worthy of further trial, and particularly in the treatment of severe or anginose cases of scarlet fever. The technic is very simple and the method of treatment particularly applicable in hospitals for the treatment of scarlet fever. Donors are selected after the second week of the disease, and preferably from among adolescents or adults who show no evidences of tuberculosis. From each person 30 to 100 c.c. of blood may be obtained under aseptic precautions and the serum carefully separated, submitted to the Wassermann test, cultured for sterility, and preserved with 0.2 per cent, tricresol in sterile containers in a refrigerator. In young children an intravenous injection may not be possible unless one of the larger veins, as the external jugular or longitudinal sinus, is selected. It is advisable to inject the serum as early in the disease as possible in large doses (20 to 50 c.c. for a child seven years of age) and, preferably, by intravenous injection. The injections appear to be harmless and no special precautions as to the presence of hemagglutinins or hemolysins appear necessary. Otherwise the serum may be injected intramuscularly in the gluteal region, and in the absence of specific convalescent serum normal human serum collected in the same manner may be injected. As a general rule three or four injections are required at intervals of six to twelve hours to influence the disease, and particularly the severe infections. In using whole blood the method employed by Zingher is very satisfactory. Two c.c. of a sterile 10 per cent, solution of sodium citrate in normal salt solution is placed in a sterile 100-c.c. bottle; 2 ounces of blood are collected, added, and briefly shaken; the blood is now ready for intramuscular injection. Wassermann reactions should be made beforehand on all possible donors so that the proper persons may be selected. In private practice the physician may take the blood from either one of the parents or close relatives. Acute Anterior Poliomyelitis. — During the epidemic of acute anterior poliomyelitis in 1916 interest was renewed in the treatment of the disease with intraspinal and intravenous injections of serum from recovered and normal persons. The discovery, almost simultaneously by Flexner and Lewis1 and Landsteiner and Levaditi,2 of the filterable nature of the microorganism, or virus causing the disease, was quickly followed by Flexner and Lewis/ observation that recovery from an attack of experimental poliomyelitis afforded protection to a second inoculation; and this, in turn, was followed by the detection of immunity or neutralizing substances in the blood serum first of recovered monkeys and then of recovered human beings by Levaditi and Landsteiner,4 Romer and Joseph,5 Flexner and Lewis,6 and Anderson and Frost.7 Since recovery from an attack of poliomyelitis was obviously brought about through a process of immunization similar to that in other infectious diseases, Flexner and Lewis8 endeavored to prevent the development of the infection in inoculated monkeys through the administration of blood-serum taken (a) from recovered monkeys and (6) from recovered human beings. The results, while not constant and regular, were definite. These experimental results were at once utilized as a basis of a serum therapy in man by Netter and his associates,9 who have reported a total of 34 cases of acute poliomyelitis which they have treated by the subdural method of injecting immune serum. They have undoubtedly established the fact that, as in the monkey, subdural injections intelligently carried out in man are safe. They believe, further, that they have proved them to be definitely beneficial or curative. They become increasingly convinced that the period of the disease at which the injections were made counted vitally, and they urged that the injections should be made as early as possible in the course of the infection. Further reports by Sophian,10 Alfaro and Hitce,11 Wells,12 Le Boutillier,13 Petty,14 and Amoss and Chesney15 indicate that serum taken from recently recovered cases of poliomyelitis may be employed in its treatment and probably yields the best results. The earlier in the course of the disease the serum is employed in suitable doses, the more promise there is of benefit. The action of the serum appears to be more precise and definite in arresting paralysis than in rapidly bringing about its retrogression. Physicians have usually administered the serum by intraspinal injection, but the experiments of Flexner and Amoss1 ascertained that an aseptic meningitis set up by an intraspinal injection of any serum permits the passage of immunity principles from the blood into the cerebrospinal fluid. Therefore the intravenous injection of serum may influence the course of the disease. In the serum treatment of epidemic poliomyelitis Amoss and Chesney state that the following conditions should be observed: (1) Early and prompt diagnosis and treatment; (2) intraspinal injection of immune serum; (3) intravenous or intramuscular injection of immune serum; (4) the serum employed should be collected from cases which have recently passed through an attack of poliomyelitis, as it is to be supposed that the serum will contain a greater amount of immune principles in this early period than after the lapse of many years. The use of serum from recently recovered persons otherwise healthy involves no risk in transferring the microorganism of poliomyelitis, as the virus has never been detected in the circulating blood of human beings even in the first days of the disease. Blood should be collected under aseptic precautions and the serum separated, submitted to the Wassermann test, cultured for sterility, and kept in a cold place preferably without the addition of a preservative. The addition of 0.2 per cent, tricresol does not impair the curative power. In children 10 to 20 c.c. of serum may be injected intraspinally, and 20 to 30 c.c. intramuscularly or intravenously. Adults should receive larger doses. If given before the onset of paralysis one injection may be sufficient; in cases in which some degree of paralysis develops soon after the injection, reinjection twelve to twenty-four hours later may be advantageous. If normal human serum is employed it should be injected intraspinally; the good effects occasionally observed may be due to the aseptic meningitis produced with consequent increased permeability of the choroid plexus, and the passage into the cerebrospinal fluid of immunity principles from the blood. Pneumonia.— Weissbecker,2 Huber and Blumenthal,3 and others have employed convalescent serum in the treatment of lobar pneumonia with apparently encouraging results. If this form of therapy is employed it is necessary to ascertain the serologic type of the pneumococcus producing the pneumonia in both donor and recipient and use the homologous serum. NORMAL SERUM THERAPY THE field of serum therapy has been extended in recent years by the successful use of normal serum in the treatment of various pathologic conditions, particularly the hemorrhagic diseases, some toxicoses of pregnancy, and certain skin affections. NORMAL SERUM m THE TREATMENT OF HEMORRHAGE Numerous reports by Welch,1 John,2 Franz,3 Nohlia,4 Reichard,5 Perkins,6 Claybrook,7 and others have shown that injections of normal human, horse, or rabbit serum are of considerable value in the treatment of melena neonatorum, hemophilia, purpura hcemorrhagica, hemorrhagic retinitis, intestinal bleeding in typhoid fever and in connection with cirrhosis of the liver, pulmonary tuberculosis, in some cases of uterine hemorrhage, and in surgical operations upon icteric persons. Barringer8 has reported the successful treatment, by. injections of fresh normal human serum, of unilateral kidney hemorrhage in a hemophiliac, and advises that this simple treatment should be tried in similar cases of varicose veins of the renal papilla. Levison9 has reported the successful checking of hemorrhage from the urinary bladder following a simple operation by performing cystostomy, removing clots, and filling the bladder with sterile horse serum. This form of treatment is so simple and has been so successful in checking hemorrhage in melena neonatorum and in other hemophilias following injuries or operations that it should never be omitted. 20 c.c. for infants and children and from 20 to 50 c.c. for adults. The technic is very simple. Sterile normal horse serum ready for injection may be purchased in the open market. Human serum may be secured by withdrawing blood into large centrifuge tubes (see p. 33) and allowing the serum to separate, or the clot may be broken up after an hour and the serum secured by rapid centrifugalization. For intravenous medication the serum should be free from particles of fibrin. Indeed, the whole operation may be conducted at the bedside by withdrawing blood from the donor into a flask containing sterile glass beads, and after a few minutes of vigorous shaking the defibrinated blood is injected subcutaneously or intramuscularly. Whenever human serum or blood is used and time permits, a Wassermann reaction should be performed beforehand, and it should be determined, by hemolytic and agglutination tests, that the donor's serum does not hemolyze or agglutinate the recipient's erythrocytes. (See p. 311.) Of course, all procedures should be conducted in an aseptic manner. Blood Transfusion. — Instead of injecting serum intravenously or whole blood intramuscularly in the treatment of the anemia following excessive hemorrhage, the transfusion of whole blood is frequently resorted to with excellent results. Transfusion has been employed in (a) the treatment of severe anemia following hemorrhage from injuries, operations, and child-birth; (6) in the severe anemias following single or repeated hemorrhages in typhoid fever, gastric ulcer, carcinoma, tuberculosis, or similar ulcerating processes; (c) in melena neonatorum, hemophilia, and purpura hemon-hagica; (d) in the treatment of pernicious anemia and severe anemias of the chlorotic type; (e) in illuminating gas poisoning, and (/) in the passive transfer of antibodies, as the transfusion of blood from a typhoid convalescent to a person suffering with typhoid fever. The best results have been observed in melena neonatorum, in which disease transfusion often acts as a specific remedy. In hemophilia the bleeding may be stopped, but the disease is not cured. In gastric ulcer and other ulcerative conditions complicated by repeated hemorrhages surgical intervention followed immediately by transfusion has yielded successful results. In pernicious anemia the benefit following transfusion is only temporary; repeated transfusions are usually necessary, and splenectomy followed or immediately preceded by transfusion is sometimes employed. In transfusion the person yielding the blood is known as the donor, while the person receiving it is known as the recipient or donee. In selecting a donor it is important that his blood be compatible with that of the recipient. Most observers are now agreed that preliminary agglutination and hemolysin tests should be conducted in order to avoid the occasional occurrence of severe reactions ascribed to intra vascular agglutination, hemolysis, or both. The technic of these tests is described on page 311. If a macroscopic technic is employed the reactions should not be read as negative until at least two hours have elapsed. If there is sufficient time a Wassermann reaction should be conducted with the serum of the donor. Methods. — A large number of methods have been advocated for the transfusion of blood. A number of these are direct methods and somewhat intricate and painful surgical operations, as the methods of Carrel,1 Crile,2 Elsberg,3 Sauerbruch,4 Hartwell,5 Levin,6 Janeway,7 Soresi8 and McGrath,9 employing sutures and cannulas to connect the vessel of the donor with the vessel of the recipient. In 1909 Brewer and Leggett10 used simple glass tubes coated with paraffin with satisfactory results; Pope11 modified this method by using a rubber tube between two glass cannulas inserted in the vessels of donor and recipient; Bernheim12 used two silver cannulas in the same manner, one cannula fitting into the other and completing the connection. In all of these methods, however, accidents were likely to occur which interfered with the success of the operation ; furthermore, it was difficult to maintain an aseptic technic and the amount of blood transfused could not be exactly determined. To prevent coagulation and permit the withdrawal of blood and its injection into the recipient without direct connection between the vessels paraffin coated receptacles were employed by Curtis and David,13 Kimpton and Brown,14 Satterlee and Hooper15 and Percy.16 and donor; three syringes of 25-c.c. capacity were employed. The sji-inge was filled with blood from the donor, which was then injected directly into the recipient. While this injection was being made the second syringe was being filled. When the first syringe was emptied of its blood it was immediately washed out with sterile salt solution by an assistant, so that a continuous transfusion was conducted. Lindeman1 has recently elaborated on this method, and similar methods have been devised by Kush,2 Bernheim,3 Cooley and Vaughan,4 and linger.5 Still later herudin and sodium citrate were employed to prevent coagulation and permit the performance of transfusion in a more leisurely manner. The latter substance is particularly recommended by Hustin,6 Dorrance,7 Wile,8 and Lewisohn,9 and is being widely used with satisfactory results. The blood of the donor may be kept in a refrigerator for several days without loosing its oxygen-carrying capacity, and the injection of a small amount of sodium citrate (should not exceed 0.2 per cent.) does not appear to lengthen the coagulation time of the blood of the recipient. As previously stated, the direct methods, consisting in suturing artery to vein or using cannulas and tubes to connect the vessels of donor and recipient, are being discarded in favor of the simpler methods which are more likely to be successful and yield excellent results. The syringe methods of Bernheim10 and linger11 are particularly satisfactory for the transfusion of whole blood, but require special apparatus. I have used successfully the original method of Ziemssen in transfusing adults when proper assistance was at hand for rapid work. More recently I have used the method of Lewisohn and Wile with success, and the simplicity of the method is particularly commendable. According to Wile, no unpleasant symptoms have followed the injections of citrated blood in amounts as high as 350 c.c., and the blood may be kept in a refrigerator for three to five days, which is an obvious advantage in many instances. Technic.— The technic of the citrate method of indirect transfusion of Wile is very simple. Blood is aspirated from a vein and is at once well mixed with sodium citrate in 10 per cent, solution in water (steril- ized) in the proportion of 1 c.c. of solution to 10 c.c. of blood. Exceptionally one encounters blood which requires slightly more or less citrate proportionately. Preliminary tests, 0.1 c.c. of the solution to 0.5, 1, and 2 c.c. of blood, respectively, being used, enable one to determine rapidly the requisite proportions in any individual instance. If the mixture is made in the syringe, in cases in which not more than 50 c.c. are to be transfused, the transfer can be made directly from donor to recipient. If larger amounts are to be used the blood is expelled into a flask containing the sterile solution of citrate, from which the injecting syringes are filled. In drawing the blood it is convenient to use a three-way stop-cock which communicates with the needle, with a 10-c.c. syringe containing the citrate, and with a large aspirating syringe. If the blood is to be injected at once, I heat the sodium citrate solution to 38° C.; if the blood-citrate mixture is kept in the refrigerator for some hours before injection it is well to heat the mixture before injecting large amounts by placing the flask in water at 40° C. For injecting large amounts (over 50 c.c.) the gravity method described on page 743 and illustrated in Fig. 140 may be used. In giving intravenous injections to infants the longitudinal sinus (Helmholz,1 Howard2) or external jugular vein may be used. To reach the sinus the needle is inserted through the skin in the superior angle of the anterior fontanel at an angle of 25 degrees with the scalp. A 20or 30-c.c. syringe should be used. NORMAL SERUM IN THE TREATMENT OF THE TOXICOSES OF PREGNANCY Feiux, Freund, Rongy, and others have found injections of fresh normal human serum from pregnant women, serum from placental blood, and even horse serum useful in the treatment of the vomiting of pregnancy. Freund has likewise observed that injections of Ringer's and Locke's solutions are sometimes efficacious; he has found injections of serum of some value in eclampsia, and tentatively advises its use in this condition. The same observer has employed injections of normal serum for the relief of the itching of pregnancy, and reports success. Similar observations have been made by Veiel3 and Wolf,4 especially after injections of serum secured from other healthy pregnant or recently delivered women. After the delivery of the child the cord is sponged with bichlorid solution, cut, and the maternal end bled into a sterile, wide-mouthed flask. This is placed in the refrigerator until there is complete separation of serum. In pipeting off the serum due care must be exercised not to include corpuscles. If the serum is not perfectly clear, it should be centrifuged with aseptic precautions. It is well to have each serum tested by the Wassermann reaction and 1 c.c. cultured in 100 c.c. of glucose bouillon to test its sterility. The serum is then preserved in bottles or vials, with the addition of two drops of 5 per cent, phenol to each 10 c.c. of serum. NORMAL SERUM IN THE TREATMENT OF SKIN DISEASES In addition to the good results obtained in the treatment of general pruritus of pregnancy with normal serum, Linser^Hench^and Prsetorius3 have had favorable results from injections of normal human serum or horse serum in the treatment of urticarial and chronic obstinate itching affections, especially senile pruritus, and also in malignant pemphigus. Even better results have been observed in the treatment of pemphigus, psoriasis, and other skin diseases by injections of the patient's own serum. This subject will be referred to further on. Mention may also be made of the results observed in the treatment of acute and chronic nephritis by injections of blood-serum from the renal vein of the goat, dog, or sheep. Teissier4 was probably the first to apply this form of therapy, and reports favorable results in the treatment of seven cases. Spillman,5 Bisso,6 and Dominquez7 have also published favorable reports. The treatment is based upon the assumption that the blood in the renal vein contains some of the internal secretion of the kidney, which acts favorably upon the liver and emunctories in general. This method of treatment has been advocated by the previously mentioned observers in the acute exacerbations of chronic nephritis, in acute or chronic nephritis with threatening uremia, and in arterial hypertension presumably of renal origin. Amounts of serum ranging from 10 to 50 c.c. have been injected subcutaneously, and repeated on several days or every other day until several doses have been given. A number of observers have reported favorable results following the administration of the patient's own serum in the treatment of various diseases. In most instances serum is secured by withdrawing blood into a sterile container, and defibrinating it with glass beads; this is followed by thorough centrifugalization, or the serum is secured after the blood has been allowed to coagulate spontaneously. In other instances the serum has been obtained from blisters purposely produced by the application of cantharides; in still others, and especially in tuberculosis of serous membranes, good results have been observed to follow subcutaneous injections of small amounts of the patient's pleural or peritoneal fluid. AUTOSERUM IN THE TREATMENT OF SKIN DISEASES Spiethoff,1 Strumpke,2 Gottheil and Latenstein,3 Fox,4 and other observers have secured favorable results from this form of serum therapy in the treatment of obstinate and chronic dermatoses, due to general, rather than to local causes, in which the usual therapeutic measures are ineffectual or only partially successful, as, for example, psoriasis, dermatitis herpetiformis, pemphigus, lichen ruber, lichen planus, urticaria, squamous eczema, etc. Blood is withdrawn from the patient in amounts of from 50 to 100 c.c. While still fresh, the serum is separated and injected intravenously in doses of from 30 to 40 c.c. These treatments are repeated from two to six times at intervals of from three to five days. In collaboration with Schamberg I have treated several cases of psoriasis with autoserum, injecting the serum intravenously in doses of 20 c.c. each week until four to ten injections had been given. In none wexe there any evidences of improvement. Chrysarobin ointment was not used as advised by Fox. Ravitch5 has also reported unfavorably upon the influence of autoserum alone in the treatment of psoriasis. AUTOSERUM IN THE TREATMENT OF ACUTE INFECTIOUS DISEASES Favorable results have also been observed in the treatment of leprosy with injections of serum secured by raising a blister with cantharides. Similar reports have been made by Jez6 in the treatment of erysipelas, and by Mordinos1 in that of typhoid fever, influenza, and Malta fever. Other observers have also reported good results following the injection of from 5 to 10 c.c. of the patient's serum in the treatment of gonorrheal arthritis, typhoid fever, pneumonia, and other infections. Robertson2 states that he has never observed the slighest influence of autoserum injections in the treatment of typhoid fever and pneumonia. Palmer and Secor3 have reported favorable results in the autoserum treatment of a series of cases of pellagra, and Goodman4 in the treatment of chorea. AND SPINAL CORD The treatment of syphilis of the central nervous system has always been unsatisfactory. With the discovery of salvarsan and neosalvarsan, the hope was fostered that these remedies would prove of therapeutic value in the treatment of tabes dorsalis, paresis, and cerebrospinal syphilis. Experience has shown, however, that while the progress of tabes dorsalis may be arrested in the early stages by vigorous treatment, in paresis the prognosis is much less hopeful. As these diseases are now known to be truly syphilitic, the presence of Treponema pallidum having been actually demonstrated in the cerebral cortex, spinal cord, and cerebrospinal fluid by Noguchi and Moore, Nichols, Graves, Marie, Levaditi, and others, the cause for failure in the treatment of these infections must be ascribed largely to the fact that the choroid plexus filters out salvarsan and mercury, as well as antibodies, and prevents these remedies from reaching the cerebrospinal fluid, just as it prevents the entrance of serum, albumin, sugar, urea, ammonia, etc. Although there can be no doubt as to the spirocheticidal properties of salvarsan, and as to its ability to kill the treponema in the tissues, this much-desired action does not seem to occur mainly because the drug cannot gain access to the parasites. Shortly after the discovery of salvarsan and neosalvarsan hope was entertained that these remedies; when injected intraspinally, would bring the drug into direct contact with the injected tissues. Investigations by Wechselmann,5 Marinesco,6 and Ellis and Swift7 have shown, and may prove dangerous. Plaut1 showed early that the serum of patients who have received salvarsan exerts a definite antisyphilitic effect, whereas normal serum displays no such activity. Meirowsky and Hartman2 and Gibbs and Calthrop3 observed good results in the treatment of syphilis from subcutaneous injections of serum from other patients who had received salvarsan. Swift and Ellis4 then showed that serum taken from a patient within six hours after the salvarsan was injected inhibited the growth of Treponema pallidum, but that if taken before the salvarsan was administered, or within from six to twenty-four hours after treatment, there was no inhibition. These last-named observers also reported beneficial effects following the intraspinal injection of salvarsanized serum, with but slight irritative phenomena. Further experimental studies on the spirocheticidal activity of salvarsanized serum were made by Gonder,5 Castelli,6 and especially by Swift and Ellis,7 the last-named investigators also noting that heating the serum at 56° C. for half an hour markedly increased its activity, which was due in part to the destruction of some inhibiting substance. Shortly after this Swift and Ellis 8 published a report of the treatment of a number of cases of tabes dorsalis and other syphilitic infections of the central nervous system with intraspinal injections of salvarsanized serum. In practically all these cases clinical improvement was observed, with total or partial disappearance of the positive serobiologic findings in the cerebrospinal fluids. Subsequent reports by Hough,9 McCaskey,10 Riggs,11 Pillsbury,12 Eskucken,13 Boggs and Snowden,14 Litterer,15 McClure,16 Krida,17 Ayer,18 Draper,19 Smith,20 Dexter and Cummer,1 Walker and Haller2 on the treatment of a number of cases of tabes dorsalis, paresis, and other syphilitic infections of the central nervous system showed that this method of treatment possesses distinct value. Cutting and Mack,3 Myerson,4 and Mapother and Beaton5 have reported unfavorable or indifferent results. Intraspinal injections were advocated by Swift and Ellis in the treatment of these diseases as an adjuvant to intravenous injections of salvarsan, as a part of an intensive medication aiming to bring salvarsan into intimate contact with the parasites in the most direct and safest manner. While this form of treatment has, in a large percentage of cases, effected a marked improvement in the subjective symptoms and has modified the underlying pathologic tissue changes, as evidenced by the disappearance or improvement of objective signs and serobiologic findings in the cerebrospinal fluid, it must still be considered in the experimental stage, for sufficient time has not yet elapsed to permit an estimate of its ultimate effect to be made. It is especially indicated in early and incipient cases of syphilitic infections of the nervous system. It is self-evident that it cannot be expected to cure cases in which marked tissue destruction has occurred, but if it serves to cure early and incipient cases of tabes and paresis, or at least tends to arrest their progress and possibly the further progress of more chronic cases, and gives symptomatic relief, then this mode of therapy is a valuable one. At present it is apparent that, in the hands of careful and competent persons, and with the strict observance of the original technic, the method is relatively devoid of danger and constitutes a new, rational, and valuable addition to the treatment of diseases that may otherwise prove intractable to the ordinary antisyphilitic measures. Technic. — From 0.6 to 0.9 gm. of salvarsan or neosalvarsan is injected intravenously. One hour later 40 c.c. of blood are withdrawn directly into centrifuge tubes and allowed to coagulate, after which it may be centrifugalized. The following day 12 c.c. of serum are pipeted off and diluted with 18 c.c. of sterile normal salt solution. This 40 per cent, serum is then heated at 56° C. for one-half hour. After lumbar puncture the cerebrospinal fluid is withdrawn until the pressure is reduced to 30 mm. cerebrospinal fluid pressure. The barrel of a 20 c.c. Luer syringe (which has a capacity of about 30 c.c.) is attached to the needle by means of a rubber tube about 40 cm. long. The tubing is allowed to fill AUTOSERUM THERAPY 839 with cerebrospinal fluid, so that no air will be injected. The serum is then poured into the syringe, and permitted to flow slowly by means of gravity into the subarachnoid space. At times it is necessary to insert the plunger of the syringe to inject the last 5 c.c. of fluid. It is important that the larger part of the serum should be injected by gravity, and if the rubber tubing is not more than 40 cm. long, the pressure cannot be higher than 400 mm. Usually the serum flows in easily even under a lower pressure. By the gravity method the danger of suddenly increasing the intraspinous pressure to the danger-point, such as might occur with rapid injection with a syringe, is avoided (Swift and Ellis). The method of injection by gravity is described on p. 746. In the absence of a suitable manometer for estimating cerebrospinal fluid pressure the blood-pressure may be taken as a guide; in any event the serum should be injected slowly. McCaskey consumes about six or seven minutes in administering the salvarsan intravenously, and advises withdrawing the blood twenty minutes thereafter, instead of waiting an hour in order to secure a larger quantity of the drug in the serum. He injects 15 c.c. of serum in 50 per cent, dilution intraspinally, and has not observed any increased irritative effects. Swift and Ellis inject the serum in strengths of 50 to 60 per cent, or even higher in patients who do not exhibit reactions following the injection of 40 per cent, serum. Boggs and Snowden withdraw from 75 to 100 c.c. of blood one hour after the salvarsan injection, secure the serum, heat it at 56° C. for one-half hour, and inject the undiluted serum in a dose equal to the amount of fluid withdrawn, whether this is only a few or as much as 30 c.c. The method employed by Marinesco and Minea,1 whereby the patient's serum is salvarsanized in vitro, is not to be regarded as the same as the method of Swift and Ellis. The first-named investigators sought to administer larger doses of salvarsan by this method, but in a preliminary report, covering the treatment of 20 cases receiving injections every seven to eight days, the results are said to have been disappointing. The recent unfortunate outcome of this form of therapy in the County Hospital of Los Angeles is ascribed to the oxidation and consequent toxicity of the neosalvarsan as a result of allowing the salvarsanized serum to stand for twenty hours before injecting it. After-treatment. — The patient should be kept in bed for twenty-four hours and the foot of the bed should be elevated for part of this time. 1 Bull, de 1'Acad. de Med., 1914, Ixxvii, No. 7. Usually the temperature reaction is mild. There is frequently some pain in the legs, which appears a few hours after the injection is given. The pain is more often noticed in tabetics than in patients with cerebrospinal syphilis. It can usually be controlled by means of phenacetin and codein, but occasionally morphin is required. In a few instances violent maniacal symptoms have developed, due possibly to the direct irritant action of the drug on the tissues, aided by the sudden liberation of endotoxins from myriads of killed spirochetes. Serobiologic Findings in the Cerebrospinal Fluid. — In all cases before the treatment is undertaken a Wassermann reaction should be performed with the blood and cerebrospinal fluid of the patient. A total cell count should also be made with a specimen of fluid, the percentage of lymphocytes ascertained, and a Noguchi butyric-acid-globulin test performed. Normally, the cells number about 8 per cubic millimeter of fluid (counted with a Fuchs-Rosenthal counting chamber) ; the presence of more than 15 cells in this quantity of fluid may be regarded as bordering on the pathologic. In tabes and paresis the cells may vary in number from 50 to more than 100, and are mostly small lymphocytes. A normal cerebrospinal fluid remains clear or shows a faint opalescence when tested by the Noguchi butyric-acid test. In tabes, paresis, etc., varying degrees of cloudiness and the presence of precipitates are observed. Repeating the Dose. — Usually a number of treatments are required, and these may be given at from one to three weeks' intervals, depending upon the condition of the patient. The results are estimated from the subjective and objective symptoms and from an examination of the cerebrospinal fluid. A decrease in the degree of positiveness of the Wassermann reaction and diminution in cells and in globulins are favorable signs. Theoretically, treatment should be continued until the Wassermann reaction becomes negative, the cells reach normal proportions, and the globulins show no increase. Practically, it may be impossible to secure these results; in many instances the Wassermann reaction is the first to disappear. A total cell count of the fluid is not to be depended upon without a differential count with stained smears, for the injections may produce a form of aseptic meningitis, accompanied by an outpouring of polynuclear leukocytes. This subject has previously been referred to in a consideration of the serum treatment of epidemic meningitis. Mechanism of Therapeutic Action.— The method of Swift and Ellis has been criticized on the basis that it was unnecessary because the intravenous injection of salvarsan was all-sufficient in its action. The authors were led to use the method, however, on the basis of the investigations of Adler,1 Hall,2 Swift,3 Camp,4 and others, indicating that no arsenic or only mere traces appear in the cerebrospinal fluid after the intravenous injection of salvarsan. The method has also been criticized on the basis of the small amount of arsenic injected intraspinally; Draper,5 Swift,6 and Adler7 have shown, however, that blood drawn a short time after rthe intravenous injection of salvarsan contains a definite although minute amount of salvarsan. It would appear, therefore, that in this method of treatment salvarsan is introduced directly into the cerebrospinal fluid. Beneficial effects may also be due to the withdrawal of the cerebrospinal fluid with consequent increased exudation into the subarachnoid space of serous products from the blood-vessels of the meninges. Furthermore, as shown by Flexner and Amoss,8 the intraspinal injection of most any fluid, as sterile salt solution or normal serum, results in an aseptic meningitis and increasing the permeability of the choroid plexus and meninges, and in this manner the salvarsan injected intravenously may be brought into the cerebrospinal fluid, the intraspinal injection serving primarily to excite the aseptic meningitis, although the experiments of Stillman and Swift9 showed that this probability is rather remote. AUTOSERUM IN THE TREATMENT OF TUBERCULOSIS OF SEROUS MEMBRANES Numerous investigators, as, for example, Gilbert,10 Marcon,11 Schnutgen,12Fishberg,13Pfender,14 Robertson,15 and others, have reported favorable results in the treatment of tuberculous pleurisy with effusion, cases that arise either insidiously or abruptly with pain in one already tuberculous, or in one in whom tuberculosis is suspected, following withdrawal of a portion of the fluid and immediate injection of from 2 to 5 c.c. into the subcutaneous tissues. In these cases there is usually a sharp reaction, consisting of a rise in temperature, occasionally ac- companied by chill, lassitude, and, in the majority of cases, diuresis or, more rarely, diarrhea, followed by gradual absorption of the fluid within the following few days up to two or three weeks. Fishberg mentions the disappearance of pain, dyspnea, and prostration within two or three days in favorable cases. It is difficult to state whether the improvement is due to autotherapy or simply to the puncture and removal of so much fluid. Eisner1 has seen a leukocytosis follow injection of serum in experimental tuberculous infections of rabbits and guinea-pigs, and believes that this explains the good results in this particular ^orm of therapy. Zimmermann2 has expressed a similar opinion. Other investigators assert their belief in the presence of aggressins, bacteriolytic amboceptors, complements, and endolysins from disintegrated leukocytes as explaining the results. It is more likely that these fluids contain the bacilli or their products, and constitute a form of vaccine or auto-tuberculin, stimulating body-cells to produce antibodies largely in the nature of bacteriotropins and bacteriolysins. Levy, Valenzi and Ponzin,3 Szurek,4 and Arnsperger5 are inclined to believe that the beneficial results are obtained independently of the injections, and while the procedure is quite generally regarded as perfectly safe, Jousset6 has recorded a case of cold abscess following an injection. This mode of treatment seems to have failed in about 10 to 15 per cent, of cases. The technic is very simple, and the injections may be given by any physician who can make an ordinary exploratory puncture. In all cases where puncture shows the presence of a serous fluid, the needle should not be withdrawn completely, but when its point has reached the subcutaneous tissues, from 2 to 5 c.c. should be injected then and there. In some patients it will be necessary to repeat the treatment several times every two or three days before any effect becomes evident. Caforio 7 has reported good results following the tapping of a bilateral hydrocek and injection of a portion of the fluid into the subcutaneous tissues. It would appear that this procedure may be successful in hydrocele of tuberculous origin, but good results are not to be expected in cases due to contusion, puncture wounds, gonorrheal epididymitis, or orchitis. advisable to withdraw fluid into an equal volume of 2 per cent, sodium citrate in normal salt solution, heat at 60° C. for one-half to one hour, and preserve in a sterile container with the addition of a few drops of 5 per cent, phenol until ready for subcutaneous injection in doses of from 2 to 5 c.c. It would appear, therefore, that reintroduction into the body of fluids obtained from the serous cavities (pleural, peritoneal) of tuberculous patients may be of value in treatment, and, as a general rule, the earlier in the course of the disease that the autoserum therapy is practised, the better will the results be. A similar treatment may be carried out in the subacute or chronic forms of tuberculous meningitis. Fluid is to be collected in sodium citrate solution, heated, and preserved with phenol, as just described. The dose may vary from 0.5 to 2 c.c., according to age and clinical conditions. AUTOSERUM IN THE TREATMENT OF NON-TUBERCULOUS EFFUSIONS In pleural and peritoneal effusions of renal, cardiac, or hepatic origin, this method of autotherapy has generally failed. Following the apparent success of Hodenpyl1 in the treatment of a case of cancer with injections of the patient's ascitic fluid, the autopsy subsequently showing the presence of metastatic cancer not demonstrable during life, Risely2 treated 65 cases of cancer with ascitic fluids obtained from cancer patients in all stages of the disease, and also with various normal and abnormal body fluids from other than cancerous conditions. None of these various transudates was found to exert any effect in retarding the growth of cancer in mice, and while in a small percentage of cases large doses of ascitic fluid of cancerous origin may relieve pain and retard the growth of the cancer for from one to five months, no permanent effects, either preventing or checking the disease, were apparent. Leavy and Hastings8 and Carter4 have drawn attention to the apparent improvement in marasmic infants following the daily injection, for a number of doses, of an ounce of sterile ascitic fluid (the result of cardiac or renal disease) into the subcutaneous tissues of the gluteal region or abdominal wall. As these fluids are non-toxic, reinjection is a justifiable procedure after the fluids have been subjected to the Wassermann reaction and to careful cultural and animal injection tests to prove their sterility. CHEMOTHERAPY FROM the earliest times, healers of the sick have sought specific remedies in the form of drugs or methods that would always and unfailingly effect the cure of a certain disease, and indeed this search has been extended for a single remedy that will cure all diseases, regardless of their origin and nature. To this end, throughout the ages experimentation, conscious or otherwise, has gone hand in hand with medicine. Countless substances gathered from the vegetable, animal, and mineral kingdoms have been experimented with, but for the most part have been discarded. Despite this persistent search for specifics, until comparatively recent times but two remedies have been found worthy of being regarded as specifics, namely, cinchona bark for malaria, a remedy discovered by the South American Indians, and mercury for syphilis. With discoveries in bacteriology and the establishment of the etiologic .relationship of various microorganisms to certain diseases, testtube experiments soon demonstrated that certain substances could quickly and easily destroy these microparasites. It was apparent, however, that in the animal body conditions were different; here the germicide, even when administered in doses sufficiently large to prove dangerous to life, usually failed to kill the microorganisms. The exceptions were quinin and mercury, which we now know are specifically germicidal for the plasmodium and spirochete respectively, a fact that was suspected long before the parasites themselves were discovered. In the latter part of the eighties it was discovered that the blood possessed germicidal powers, and rapid advances were soon made in our knowledge of the defensive mechanism of the animal body, and the means afforded for preventing infection, and even of successfully overcoming it if, by any chance, microorganisms passed the normal barriers and gained a foothold on the tissues proper. Here indeed was a more or less specific therapy that was not suspected until 1894, when diphtheria antitoxin was discovered. It was then speedily realized that body-cells could be made to produce a specific remedy for a certain disease, and it was naturally assumed that this was possible for all those cultivated. In the foregoing chapters we have reviewed our knowledge of the nature of these specific remedies produced by the body-cells and called antibodies. In Chapter XXX we have also reviewed the application of these remedies in the treatment of various infections, and have pointed out their limitations and the difficulties encountered in their production. Naturally, in the early days it was deemed necessary and advisable to utilize a lower animal for the manufacture of these antibodies. With the discovery of a means of attenuating or modifying a disease-producing parasite it was found possible to inject these vaccines into our own bodies, and thus stimulate our own cells to produce the specific antibody— a method that had been introduced empirically years before by Jenner in vaccination against smallpox. As was previously stated, scientists have long believed that it was possible to find or produce chemical substances that would not unite with the blood albumin or body-cells, but would have a highly selective and germicidal action on microparasites and prove capable of killing these in the living body. Curiously enough Ehrlich, to whom we are already indebted for much of our knowledge of the intricate problems of cell life, and especially the mechanism of their defense and offense against parasitic invaders, has again taken the lead and set about testing hundreds of compounds in a painstaking, logical, and scientific manner, in the hope of finding one that would prove most germicidal for various trypanosomes and spirochetes, and at the same time be least toxic for the body-cells. These researches finally culminated in the discovery of the arsenical compound now popularly known as salvarsan. This discovery constitutes a great triumph for medical science, not only because of the intrinsic value of the drug in the treatment and cure of syphilis and frambesia, but because it demonstrates the truth of a principle, and has opened up vast possibilities for future investigation. PRINCIPLES OF CHEMOTHERAPY Organotropism and Parasitotropism. — The guiding principle in chemotherapy is to imitate nature's method of overcoming an infection by the aid of substances that destroy the microorganisms, while the body-cells of the host are left unharmed. To this end the chemical agent employed must possess a much stronger affinity for the microorganisms than for the body-cells — to quote Ehrlich, it must be more parasitotropic than organotropic. If a given chemical agent shows a greater affinity for the albumins of the body-juices and for the cells than it does for the protoplasm of the microparasites, that is, if it is more organotropic than parasitotropic, it is evident that it is not suitable for therapeutic purposes, especially if, at the same time, the toxic dose for the host should be smaller than that for the microorganism. The object of chemotherapeutic research is, therefore, to discover chemicals that have a greater parasitotropic than organotropic activity, and the greater the difference between these, the more valuable do the substances become. There is only one way of determining these values, and that is by animal experimentation. Rats, mice, guinea-pigs, rabbits, and fowls have been most generally employed for this purpose, and most work so far has been done with protozoan parasites, such as the organism of chicken spirilloses, the spirillum of recurrent fever, various trypanosomes, and the spirochete of syphilis. These were selected because they are readily found in the blood or in lesions, and are rapidly pathogenic. As a result of the study of several hundreds of different products by Ehrlich and his collaborators and by many other noted investigators, it was found that there are, after all, comparatively few that exert a parasitotropic effect in animals; these are, however, well characterized chemically, and have been classified into three main groups : 1. The group of arsenical compounds— arsenious acid (arsenic trioxid), atoxyl, arsacetin, arsenophenylglycin, dioxydiamido-arsenobenzol dichlorhydrate (popularly known as "606," or salvarsan), and various antimony compounds. Newly discovered drugs are administered in increasing amounts to experimental animals until the toxic dose (dosis lethalis), the tolerated dose (dosis tolerata), and the curative or sterilizing dose (dosis curativa or sterilisana) have been determined. While chance may succeed in giving us a drug fulfilling the requirements, so far it has had little influence, and it is difficult to realize the tremendous amount of work done by Ehrlich and the members of his institute before salvarsan was discovered. The following table illustrates the relation of the tolerated to the curative doses of a few chem- ical substances, including salvarsan, given by intramuscular injection, in spirillosis of fowls, and illustrates the particular value of "606," as dependent upon the fact that it is highly parasitotropic in an amount that is far below the organotropic or toxic dose : Chemoreceptors. — Of considerable interest in this connection is the question of how substances can be modified in order to render them progressively more parasitotropic and less organotropic in action. When ordinary germicides, such as phenol, mercury bichlorid, formalin, etc., are added to suspensions of bacteria, we believe that the latter are killed mainly as the result of poisoning of their protoplasm, and that the chemical substance enters into chemical union with the bacterial albumins by direct toxic action, accompanied by such physical changes as that of coagulation, and alters bacterial metabolism and brings about death of the cells. Such germicides do not appear to exert any selective action on any particular albumin. When mercury bichlorid is added to a mixture of bacteria in a serum, many of the microorganisms may escape destruction through the formation of protective envelops of an albuminate of mercury formed with the serum albumins; a similar action may be noted with phenol. In chemotherapeutic research, therefore, it is the aim to start with a substance that primarily shows a more marked affinity for the protoplasm of the parasite than it does for the body-cells, and then, by subtracting or adding to the molecule or by inducing an intramolecular rearrangement, an effort is made to develop its parasitotropic action. The question then arises, does the increased parasitotropism of the chemical substance depend upon its higher direct and simple action upon the protoplasm of the microparasite, or is this effect to be explained upon its increased combining power or affinity for the molecules of the parasites or other cells because the latter are provided with special groups for effecting the union? Ehrlich has endeavored to answer this question by maintaining that both body-cells and microparasites possess special receptors or side-arms by which chemical substances may be bound; these he terms chemoreceptors. While Ehrlich originally assumed that the so-called side-arms of the protoplasmic molecule served primarily for the process of nutrition, he now believes that these special chemoreceptors do exist. He suggests that they may probably possess a less complex structure, similar to the receptors of the first order for simple toxins, that they are more firmly attached to the cell, and that, accordingly, they are less readily cast off, thus explaining why crystalline chemical substances are, as a general rule, incapable of eliciting the production of corresponding antibodies. This theory is based upon the discovery that certain strains of a microparasite develop a state of " resistance" or "fastness" to a particular substance, and that this acquired characteristic may be transmitted from generation to generation. This subject will be further discussed elsewhere. According to Ehrlich's postulate, therefore, toxic agents cannot act on microorganisms unless they are fixed by suitable receptors (corpora non agunt nisi fixata) . This conception is similar in every way to his conception of the processes of infection and immunity and the development of antibodies; that is, the toxic agent must first be " fixed" or "anchored" to the molecule of a cell by suitable receptors by a process of chemical interaction before damage can be inflicted. Chemoreceptors differ from other receptors in being more firmly attached to cells, so that while the cell may become immune to the toxic effects of the agent, the blood-serum may not contain the immune bodies. When arsenic is introduced into the body, it is "fixed" by the receptors of certain cells; mercury in turn is fixed by other receptors, and so on through the list. The basic principle of chemotherapy is that it is possible to produce chemical substances that carry side-arms capable of being fixed by microparasites, and to a much less extent by the body-cells. It is not necessary that the whole molecule of a toxic substance possess a combining affinity for certain receptors: if one or more atom groups becomes attached, it is presumed that it carries with it the remainder of the molecule. Moreover, that atom group that is anchored or is responsible for the anchorage of the entire molecule need not possess any of the properties of the entire molecule or of any part thereof. For example, when the molecule of salvarsan is anchored to the spirochete of syphilis by its OH or its NH2 side-chain, or by both, the spirochete must later contend with two molecules of arsenic, which, being in a trivalent condition, can exercise its toxic effects to a marked degree upon the parasite. The side-arms as they exist in salvarsan are much more readily taken up by the spirochete than by the body-cells, which is shown by curative dose. Drug "Fastness." — In the foregoing chapters we have sought to emphasize the importance of the microorganism in the processes of infection and immunity from the standpoint of the possibilities of these cells immunizing themselves against the deleterious agencies of the host, and particularly the antibodies, as explained in the hypothesis of Welch. (See p. 104.) It soon appeared that the problem of chemotherapy was greatly complicated by these activities on the part of the parasite, so that the hypothesis appears to be further supported as a result of chemotherapeutic studies. If the dose of a chemical is just small enough to allow a few microorganisms to escape, these immediately fortify (" immunize") themselves against the drug and become invulnerable to its effects. It was found that these microparasites were then able to multiply, even in the presence of the drug, and, further, that this property of "drug resistance" was transmitted from one generation to another. If, for example, the trypanosomes in a mouse have become resistant to trypan red, a quantity of these trypanosomes may be inoculated into another mouse, and from this one to another, and so on, for many generations, and it would finally be found that the trypanosomes still. retained their immunity to the action of trypan red. This acquired resistance or "fastness" is in a large measure specific. A strain of trypanosomes resistant to the benzidin dyes is non-resistant to arsenic and the triphenylmethane dyes, whereas one resistant to arsenic is not resistant to the dyes, etc. As Levaditi and Fraser have shown, the antibody-resistant trypanosomes do not anchor the antibody, hence it is probable that the analogy holds for the drug-resistant microparasites. As was previously stated, Ehrlich has explained this phenomenon on the basis of chemoreceptors. He has ascertained that "fastness" for a certain chemical agent does not depend on atrophy of the corresponding receptors, but upon a modification in their structure, as is evidenced by the fact that, by changing the structure of the chemical, it may still find suitable receptors and lead to the destruction of the parasite. For example, mice that have been infected with arsenic-fast trypanosomes may be cured by an injection of arsenophenylglycin, even at a time when death is imminent. It would appear, therefore, that the arsenic-fast receptors of the trypanosomes were but slightly altered, and were still capable of uniting with an allied product. destruction of trypanosomes by an arsenical preparation has not been complete, and if the antibodies produced by the body-cells do not succeed in destroying the remainder, there is a strong probability that a new strain will now develop that will be resistant not only to the particular arsenical preparation used, but will also be proof against the serum antibodies. This new strain may now cause a relapse of the disease. Another chemical is now injected, but if this likewise fails to kill all the trypanosomes, the remainder will generate still another strain "resistant" to the preparation and the antibodies. This may continue as long as the parasite is able to produce new receptors; when this limit is reached, its nutrition will be impaired and the serum antibodies, alone or aided by another chemical substance, may finally destroy all trypanosomes, the infection "dying out/' so to speak, or proving completely vulnerable to a chemical agent. These considerations have an actual experimental basis, and natural examples of acquired serum-resistance or "fastness" are to be found in relapsing fever, syphilis, sleeping sickness, and possibly malaria. Noguchi and Akatsu1 have recently succeeded in rendering different strains of spirochetes "drug-fast" to various compounds of arsenic and mercury in vitro. In relapsing fever the clinical course of the disease would indidicate that only three or four serum-fast strains can be produced, and we accordingly find that, after a patient has withstood a number of relapses corresponding to the number of antibody-fast strains that the spirillum may produce, spontaneous recovery occurs, there being then antibodies that the strain cannot resist, and the infection "dies out," due in part to destruction of the antibodies and in part to starvation of the parasite because the number of receptors is insufficient to carry on nutrition. In the mean time, however, the patient may succumb to the disease before the spirillum has "played its last card." In syphilis conditions are different, and the phenomenon of "resistant races" further explains many conditions not previously understood. The spirochete is apparently capable of repairing its receptors to a remarkable degree, especially after injury received from the antibodies produced by body-cells, and, further, is able to maintain its nutrition with a number of different food-stuffs, so that in the untreated person relapse follows relapse, the offensive forces of the spirochete being held in abeyance by the defenses of the host over long periods of time (latent periods), but the vital parts of the host being gradually damaged and the defenses weakened so that death or serious symptoms may supervene 1 Jour. Exper. Med., 1917, xxv, 349 and 363. in syphilis. The theory of chemoreceptors affords an explanation of this phenomenon, just as the side-chain theory affords an explanation of the formation of cellular antibodies and the processes of immunity. In adopting it we must be prepared to believe that the number of receptors and the possibilities of their repair or modification are practically unlimited, as evidenced by the large nervous system, cardiovascular system, etc. Therapia Magna Sterilisans. — As the development of resistant strains is thus one of t?he possibilities and impediments to successful specific therapy, whether with chemicals (chemotherapy) or with antibodies (serum therapy), our efforts should be directed toward discovering chemical substances and a method of administration that will completely sterilize the individual at one time (Ehrlich's therapia magna sterilisans). This possibility has been amply demonstrated experimentally by Ehrlich, and it has occasionally been accomplished ia the early stages of human syphilis by means of salvarsan administered early in the proper manner and in correct dosage, but, unfortunately, it is not true of the majority of cases, the difficulties increasing with the duration of the infection. Fortunately, the investigations of Margulies 1 "Die Behandlung der Syphilis" (Konigsberg Versammlung), Leipzig, 1910, 930. have shown that while resistant races of trypanosomes are easily evolved, the evidence is entirely against the probability of the development of arsenicresistant syphilitic spirochetes as the result of prolonged treatment 'with nonsterilizing doses of salvarsan. Akatsu and Noguchi1 have, however, increased the tolerance of Treponema pallidum to salvarsan and neosalvarsan five and-one-half times their original mark by cultivating the spirochete in culture-media containing these drugs. up vast possibilities in the development of a specific therapy for all infections. One fact is certain: that while chance must ever play some role, future discoveries will probably result only from prolonged, patient, and laborious study. SALVARSAN AND NEOSALVARSAN IN THE TREATMENT OF SYPHILIS Historic. — The administration of arsenic in protozoan infections has long been a recognized method of treatment. The organic compound of arsenic known as atoxyl (the sodium salt of para-aminophenylarsenic acid) was first used in the treatment of trypanosomiasis, and although this drug did not produce the results that were anticipated, it formed the starting-point for important researches in the preparation of organic compounds of arsenic and their use in protozoan infections. On the strength of Schaudinn's statement regarding the close biologic relationship of the spirochetes of syphilis to trypanosomes, Uhlenhuth was led to employ atoxyl in the treatment of experimental spirillosis in fowls. These experiments, in addition to those of Weisser and Metchnikoff, demonstrated beyond doubt the curative and prophylactic properties of atoxyl in spirillar infections. The drug was, therefore, administered in cases of syphilis in the human subject. It was found to exert a very beneficial effect, especially in malignant forms of the disease. Further experience, however, demonstrated that atoxyl was too toxic for use in the human subject, for digestive disturbances, nephritis, and especially optic atrophy could be traced to its use, even in small doses. As a therapeutic agent, therefore, it has gradually come into disfavor. Ehrlich and Bertheim then made the valuable discovery that the chemical constitution of atoxyl was not, as had been supposed, that of a metarsenate, but that it was in reality that of a para-amidophenylarsenate. Working on this basis, these observers prepared the substance known as arsacetin (the sodium salt of acetylpara-amidophenylarsenic acid), which, although less toxic than atoxyl, did not fulfil the requirements of a remedy, and its use was discontinued because of its toxic effects on human tissues. To lessen the relatively great toxicity of these compounds for human tissues was a problem that Ehrlich set out to solve. A most important advance in this direction was made when it was discovered that the unsaturated triyalent arsenic in arsenobenzol and arsenophenylglycin has a greater parasiticidal power relative to its toxic action on the tissues of the host than the pentavalent arsenic compounds, such as atoxyl and arsacetin. Finally, after testing hundreds of these arsenical compounds, it was found that in dioxydiamidoarsenobenzol we had a substance that approached the ideal in chemotherapy, since it is a drug that possesses a maximum degree of parasitotropism and a minimum degree of organotropism. Ehrlich and Hata designated this light yellow, readily oxidizable powder as No. 592. Its hydrochloric acid salt was designated No. 606, and constitutes the well-known salvarsan. In the published account of their researches Ehrlich and Hata1 describe an extensive series of investigations in experimental relapsing fever, spirillosis of fowls, and syphilis of rabbits. These go to prove the high curative value of salvarsan, its relatively feeble toxicity for the substances that possess spirillicidal properties. Clinical evidence in the treatment of human syphilis supported the experimental findings. On account of the disadvantages of salvarsan, due to its insolubility and the necessity for using the hydrochlorid, and also in an effort still further to lessen its toxicity, Ehrlich conducted further researches to discover a neutral salt that would be more soluble and less toxic. As a result of these efforts neosalvarsan, or "914," has been produced. This number is significant of the number of experiments performed since the discovery of "592" and "606." Properties of Salvarsan. — Salvarsan is the dihydrochlorid of dioxydiamidoarsenobenzol, and occurs as a yellow, crystalline, hygroscopic powder, very unstable in air, and easily oxidized to poisonous compounds. It is marketed commercially put up in small sealed vacuum tubes. It contains 31.57 per cent, of arsenic, is readily soluble in water, particularly in hot water, and yields a solution having an acid reaction. If the acidity is neutralized by the addition of caustic soda solution, the unsoluble base (dioxydiamidoarsenobenzol) is precipitated. If only half of this amount of alkali is added, then the monohydrochlorid of dioxydiamidoarsenobenzol is formed. If, in addition to the amount of caustic soda necessary to precipitate the base, a further quantity of alkali is added, the hydrogen atoms of the phenol hydroxyls become replaced by Na and the compound goes into solution as the disodium salt of dioxydiamidoarsenobenzol: Test-tube experiments showed less spirillicidal power of the drug than is demonstrated in the living animal. The following table shows the toxicity of the preparation (Ehrlich and Hata) : In experimental syphilis of rabbits the minimal dose necessary to produce a complete cure was found to be between 0.01 and 0.015 gram per kilogram. The tolerated dose by intravenous injection is 0.1 gram. The curative dose of salvarsan in syphilis of rabbits is, therefore, only from one-seventh to one-tenth of the tolerated dose. Studies in the Toxicity of Salvarsan. — During the past two years Dr. Schamberg, Dr. Raiziss, and I1 have studied the toxicity of salvarsan and have reached the following conclusions: 1. Salvarsan may be used in concentrated solutions up to 0.6 gm. in 20 c.c. per 70 kilograms of body weight in animals without any evident increase of toxicity; in man, however, it would appear that the administration of concentrated solutions of salvarsan increases the toxic effects. cent, concentration. 3. The addition of a moderate excess of alkali beyond the amount required for neutralization does not increase the toxicity, as determinable by the duration of life of the experimental animal. It is possible, however, that it may have other untoward effects. 4. The use of sterile fresh distilled water appears to possess advantages over sterile stale distilled or non-distilled water as regards toxicity, although the difference in our experiments was not pronounced. 5. Salvarsan in alkaline solution tends to undergo oxidation on standing, with consequent incresed toxicity, but this substance and its congeners vary considerably in the rapidity of oxidation and in the degree of associated toxicity. The drug should be used reasonably promptly after preparation. If two or three hours* delay is unavoidable, the solution should be kept in a cylinder full to the stopper, so that no air is present. 6. Several different types of reactive symptoms may occur after the use of salvarsan: (a) immediate, (6) early, and (c) delayed. The immediate symptoms are due to a paresis of the blood-vessels; the early symptoms coming on a few hours after the injection are febrile and gastro-intestinal, and the delayed symptoms may be referable to the brain or the liver and gastro-intestinal tract. This subject is discussed in greater detail on page 867. 8. Salvarsan and its congeners may vary, within certain limits, in therapeutic effect, and to a greater degree in toxicity. The ampules obtainable in the open market exhibit striking variations in toxicity. 9. Even the poorest compounds, however, are tolerated by animals in much higher amounts than the maximum dose administered to man, so that there is nearly always a latitude of safety. for weight. Properties of Neosalvarsan. — This is an orange-yellow powder possessing a peculiar odor. It is very unstable in the air and is readily soluble in water, yielding a yellow solution that is neutral to litmus. Its structure is somewhat more complex than that of salvarsan, being a condensation-product of the latter and hydraldit (formaldehyd sulphoxylate of sodium), the reaction taking place according to the following equation: While neosalvarsan is less toxic than salvarsan, and although it is much more easily administered and largely free from irritative effects, recent clinical reports would tend to show that its spirocheticidal properties are somewhat less than those of salvarsan. Sodium Salvarsan (Salvarsannatrium). — Ehrlich has recently perfected a sodium salt of salvarsan which may be called a "neutralized salvarsan," a product regarded as possessing the curative value of salvarsan and the lower toxicity and ease of administration of neosalvarsan. The reports of Wechselman,1 Dreyfus,2 Loeb,3 Fabry and Fischer,4 and Gutman5 regarding the therapeutic value of the new and is not yet available in America. The doses are similar to those of salvarsan, averaging 0.4 to 0.6 gm.; Wechselman1 has administered as much as 1 gram in a dose. The compound resembles salvarsan in appearance except that the powder has a greenish hue and the solutions are somewhat darker in color. Solutions of the drug oxidize rapidly and must be administered promptly. The drug is readily soluble in warm water and does not require neutralization with an alkali. It has been administered in dilute and concentrated solutions dissolved in sterile distilled water and in the same manner as neosalvarsan. Wechselman uses 0.4 per cent, salt solution in preparing the solution. Methods of Preparing Salvarsan for Administration. — Soon after the introduction of the drug several methods of preparation and administration were suggested. Many of the disadvantages attached to salvarsan treatment, and many of the bad results and complications reported, are to be attributed to defective methods of preparation and administration of the drug. It is not necessary to describe the earlier methods, because these are now largely only of historic interest, and it is quite generally accepted, from the point of view both of efficient treatment and of the comfort of the patient, that the intravenous injection of a dilute solution of the disodium salt is the best form of administration. For this reason I shall briefly mention the other methods, and describe the method of intravenous injection of the alkaline solution in greater detail further on. The Acid Solution. — When salvarsan is dissolved in warm water or warm normal saline solution, a strongly acid solution is obtained. In this form the drug is most irritating and also most toxic, and when injected subcutaneously and intramuscularly, produces severe pain and necrosis. This method is seldom if ever used at the present time. amount of alkali necessary to produce complete neutralization is added, a solution of the mono-acid compound will be formed. This solution has been given intramuscularly, but is also extremely irritating. The Neutral Suspension. — This is the drug in the form of a precipitate of the base, prepared by adding to the original acid solution just sufficient caustic soda to neutralize it. The method was devised by Michaelis and Wechselmann, and for some time was the form of administration most generally employed for subcutaneous and intramuscular injection. It is probably less irritating than the acid and clear alkaline solution, but occasionally there resulted encapsulation of masses of necrotic tissue containing considerable quantities of arsenic. Other Suspensions. — Suspensions of salvarsan in liquid paraffin, sterile olive oil, oil of sesame, or almond oil are said to keep for some time if placed in dark containers. This cannot, however, be always depended upon, and the slightest decomposition of the original drug is capable of producing marked toxic symptoms. These suspensions are said to be comparatively non-irritating, but they may cause local necrosis of tissues, and on account of their slow absorption, only small amounts gain access to the general circulation at one time. This method may, however, be of value, especially in infants and in cases where slow absorption is desired in order to prolong the effect of the drug. Analgesics, such as eucain, creosote, or an essential oil, may be incorporated in the suspension in order to lessen the pain. 0.1 gram of the drug. Alkaline Solution of the Disodium Salt. — This is the form in which the drug should be administered by intravenous injection. It is this solution which Hata used in his original experiments, and it was the form recommended by Ehrlich. I shall, therefore, describe this method in detail a little further on. Dosage of Salvarsan. — Males receive in general about 0.4 to 0.6 gm. ; female patients are usually given from 0.25 to 0.5 gm. In the case of weak and poorly nourished adult patients it in inadvisable to give more than 0.3 or 0.4 gm. Since it has been generally impossible to cure a patient with a single larger dose, the practice among syphilologists at present is to give smaller doses frequently repeated. ADMINISTRATION OF SALVARSAN AND NEOSALVARSAN 859 For infants suffering from congenital syphilis the dose is from 0.006 to 0.01 gm. of salvarsan for every two pounds of body weight, so that a child of eight pounds would receive from 0.024 to 0.04 gm. of salvarsan. To older children, weighing from 40 to 60 pounds, 0.2 to 0.3 gm. may be given. Dosage of Neosalvarsan. — This preparation is less toxic than salvarsan, and may be administered in larger doses, as from 0.6 to 0.9 gm. The same general rule as to the physical condition of the patient should apply here in deciding the dosage. At the present time the tendency is to give adult patients about 0.6 gm. for three, four, and more injections at intervals of a week or so. Frequency of Injections; Intensive Treatment. — As was just stated, there is a distinct tendency among those of large experience to regard salvarsan as a more potent spirocheticid than neosalvarsan. As previously mentioned, the original idea of sterilizing the patient with one large dose of the drug has been largely abandoned, especially in the treatment of syphilis in any but the earliest stages. A large number of smaller doses are being given, and the results are controlled by the Wassermann reaction with blood and cerebrospinal fluid, in addition to the cytologic changes in the latter. Thus from 0.3 to 0.5 gm. of salvarsan or neosalvarsan is given every week or twice a week for three, four, or ten doses and more, depending upon the clinical results and the serologic findings. In this connection it must be remembered that a negative Wassermann reaction is of little value if blood has been withdrawn within one week of the last treatment. (See Chapter XXIII.) While it is the common practice to administer a number of doses of salvarsan or neosalvarsan, and to follow this with mercury and then with salvarsan again, this method must be regarded as containing an element of danger, especially since Wechselmann has drawn attention to the fact that mercury acts as an irritant to the kidneys. It may be stated that, in general, most cases of syphilis require a number of injections of salvarsan; this number depends upon the age and nature of the infection, and should be controlled by the Wassermann reaction with both blood and spinal fluid. Preparation of the Patient. — In view of the fact that many of the fatalities due to salvarsan have been ascribed to defective kidneys, especially to kidneys damaged by the previous administration of mercury, it should be a routine measure to have the urine thoroughly examined for sugar, albumin, and casts previous to the administration of salvarsan or neosalvarsan. While thousands upon thousands of injections have been made without ensuing untoward results, still the administration of this drug is not without danger, and the physician should familiarize himself with the contraindications, and subject his patient to a careful physical examination before undertaking this form of therapy. This subject will be discussed further under the head of Contraindications to Salvarsan Therapy. In the majority of cases, however, no contraindications exist and no elaborate preparations are necessary. The rectum should be emptied before the injection is given, and it is best to administer the drug on an empty stomach. After receiving salvarsan the patient should rest overnight under direct supervision, as in a hospital, the injection being given during the afternoon or early evening hours. The same practice should be followed with neosalvarsan, although in thousands of instances patients have received an intravenous injection, rested for an hour or so, and then returned to their homes. Preparation of Dilute Salvarsan Solution for Intravenous Injection. — As previously mentioned, the physician should examine the ampule containing the drug to convince himself that it is intact. The solution should be prepared just before it is injected. On account of the oxidation that occurs it is unsafe to use the drug if the ampule has been open for a number of hours, and for the same reason it is not good practice to prepare a bulk solution for a number of patients unless the physician is certain that he will be able to make the injections quickly and without interruption. as follows : 1. The diluent should consist of sterile and freshly distilled water. Many of the toxic and other ill effects attending salvarsan therapy have been attributed to the use of raw and stale water. Experments conducted by Yakimoff and Yakimoff show that the presence of the endotoxins of such microorganisms as Bacillus coli, Bacillus pyocyaneus, and staphylococci in the water increases the toxicity of salvarsan from two to eight times, the water alone and the salvarsan alone being without effect. In office practice physicians may distil water by means of some simple apparatus, such as that of Muencke. The distilled water is then sterilized in an Arnold sterilizer for one-half hour, or by boiling for ten or fifteen minutes. 3. The water should be hot; a good plan is to place 50 c.c. in a mediumsized (250 c.c.) Erlenmeyer flask and bring to the boiling-point. A mixing cylinder may be used instead. The ampule containing the drug is wiped off with alcohol, the neck filed across and broken off, and the contents gradually dusted on the surface of the water. If the entire contents of the ampule are emptied into the water in a bulk, gelatinous masses may form which dissolve with difficulty. The solution is now neutralized by adding a 15 per cent, solution of caustic soda drop by drop. This neutralization is very important, as the toxicity of the acid solution is extremely high. The sodium hydrate solution should be kept in a non-soluble glass container, made preferably of Jena glass, in order that no constituents of the glass be dissolved with the formation of a sediment. A heavy yellowish precipitate is produced by the addition of the alkali, which clears up when sufficient alkali has been added; it is undesirable to add any more alkali than is exactly necessary to clear the solution, as an excess thereof increases the irritative effect of the preparation. (If too much alkali has been inadvertently added, the excess can be neutralized by the addition of a few drops of a 10 per cent, solution of chemically pure hydrochloric acid. If the acid produces a cloud, this can again be cleared by a drop or two of alkali.) When doubt exists concerning the reaction of the solution, red and blue litmus-paper should be employed. The amount of alkali necessary is about 4 drops of a 15 per cent, solution for each 0.1 gm. of salvarsan; thus, for 0.6 gin., 1.14 c.c., or about from 23 to 45 drops of 15 per cent, solution of caustic soda, would be required. Citron gives the following table: 0.2 gm. salvarsan requires 0.38 c.c. of 15 per cent, sodium hydroxid = 8 drops. 0.3 gm. salvarsan requires 0.54 c.c. of 15 per cent, sodium hydroxid = 12 drops. 0.4 gm. salvarsan requires 0.76 c.c. of 15 per cent, sodium hydroxid = 15 or 16 drops. 0.5 gm. salvarsan requires 0.95 c.c. of 15 per cent, sodium hydroxid = 19 or 20 drops. 0.6 gm. salvarsan requires 1.14 c.c. of 15 per cent, sodium hydroxid = 23 to 24 drops. A drop more of the alkali than is just necessary to produce the clear solution should be added. If this is not done, on cooling the solution may show a precipitate; this can be redissolved by the addition of a drop of alkali. When ready for use the solution should be slightly alkaline. When the solution is neutralized, water should be added to increase the quantity to 200 c.c. for 0.6 gram of the drug or to 150 c.c. for 0.4, although the drug if injected slowly may be given in 30 to 50 c.c. I do not believe that any advantage is gained by the employment of salt solution instead of distilled water. If this is preferred, the salvarsan should be first dissolved in distilled water, neutralized, and then a sterile 0.5 per cent, solution of chemically pure sodium chlorid added to make up the desired volume. about that of the body. This flask is thoroughly shaken to insure an even diffusion of the drug, and the contents poured into the cylinder from which it is administered, being filtered into this cylinder through a piece of sterile gauze in order to remove any bits of broken glass from the ampule that may have gained access or any other insoluble particles. (See Fig. 146.) With this apparatus the operator may give an injection without assistance. Notice the three-way cock, which permits the flow of salt solution or salvarsan solution at will. Usually a tourniquet composed of a simple rubber tubing and held in position by a hemostat is better than the one shown, as the operator can quickly release it with least disturbance and loss of time. Note the funnels in both containers for straining the salvarsan solution and distilled water or salt solution. (After the apparatus of Boehm.) Preparation of Dilute Neosalvarsan Solution for Intravenous Injection.— This drug is readily soluble in water, forming a clear solution which is ready for use. File the neck of the ampule, cleanse it with alcohol, and break open. The contents are emptied directly into a flask containing 100 to 150 c.c. of warm, sterile, freshly distilled water. On gentle agitation the drug rapidly dissolves. Hot water should not be used, nor should a solution be heated once it has been made. From the mixing flasks the solution is poured into the cylinder through a piece of sterile gauze, which filters out any bits of glass or other insoluble particles. For administration any simple apparatus, such as that shown in Fig. 147, answers all purposes. Injecting Apparatus. — A number of different apparatus for the administration of dilute solutions of salvarsan and neosalvarsan have been invented and marketed. That shown in Fig. 146 is well adapted for the purpose; one cylinder carries sterile normal salt solution and the second FIG. 147. — METHOD OF MAKING INTRAVENOUS INJECTION BY GRAVITY. This method is suitable for the intravenous administration of salvarsan or antistreptococcus serum, etc. The needle has been entered into a prominent vein (indicated by a flow of blood); the tubing has been attached by means of a metal tip which fits the needle easily and snugly; the tourniquet has been loosened and the injection is being given. holds the salvarsan or neosalvarsan solution. By fastening the cylinders to an upright rod attached to the side of the table their height may be adjusted as desired, and by means of the special cock the operator may insert the needle and allow the salt solution to flow in until he is sure of having satisfactorily penetrated the vein, when he may turn on the salvarsan solution. In this manner the physician is enabled to give an injection without assistance. This consists of a single cylinder to the narrow lower end of which about five feet of rubber tubing are attached. A piece of glass tubing is inserted at the lower end to serve as a window, and at the end there is an arrangement whereby it can easily be attached to the needle used for making venipuncture. A clamp is placed on the tubing at some convenient place, where it may be operated by an assistant. Whatever apparatus is employed, it should be sterilized before use. The cylinders and needle are boiled in an office sterilizer, and the tubing is cleansed by running sterile salt solution or water through it. The needle should have a sharp point with a short beveled edge, as a longpointed needle may pierce the vein through and through. Sufficient sterile distilled water or normal salt solution is added to fill the rubber tubing, while the cylinder should contain an additional 10 or 15 c.c. If the double cylinders are used (Fig. 146), one should contain from 20 to 30 c.c. of salt solution or water and the second the solution of the drug. The solution of drug is then filtered into the second cylinder, and the pinch cock opened for a minute to be sure that all air has been expelled. 2. The patient should lie on a bed or on an operating table. An arm — usually the patient's left in the case of right-handed operators — is prepared by placing a few towels around it and a firm tourniquet is applied above the elbow. Whatever material is used, whether rubber or a broad muslin bandage, it should be fastened with a hemostat, for when it becomes necessary to unfasten it, this may be done quickly and with least disturbance by the operator, who simply unfastens the hemostat. The skin over a prominent vein may be cleansed with green soap and water, followed by alcohol and 1 : 100 bichlorid solution, or simply by adding one or two coats of 10 per cent, tincture of iodin, which is washed off with cotton and alcohol just before the needle is inserted. In fat subjects a vein can frequently be felt when it cannot be seen. Occasionally it may be necessary to infiltrate the skin with sterile eucain solution and expose the vein by incision. In nervous subjects the routine operation of inserting the needle can be made practically painless by infiltrating the skin over a vein with a few drops of a sterile 1 per cent, solution of eucain. 3. The operator now passes the needle into a vein. With experience, considerable skill is gained in performing this little operation. A free flow of blood indicates that the needle has been properly inserted, and one can easily tell by the sense of touch whether the needle is free in the lumen. The tourniquet is then quickly and deftly released by the operator, the clamp on the tube is opened, and while the blood is flowing from the vein and the saline solution or water from the tubing the nozzle of the latter is fitted into the needle quickly and securely while the latter is held firmly in the vein. The appearance of bulging at the side of the vein and the occurrence of pain indicate that the needle has not been properly inserted. In this event the clamp should be fastened, the needle withdrawn, the tourniquet adjusted, and another vein punctured. It is useless to attempt to enter the same vein at the same point. 4. The introduction of a full dose of salvarsan or neosalvarsan will usually take from ten to twenty minutes or thereabouts. If the flow is retarded, the needle may be turned gently and slightly so as to change the relation of the bevel to the wall of the vein. 5. When salt solution forms the first portion of the injection, no harm has been done if perivascular infiltration occurs. This method gives added assurance to the operator; indeed, it should never be omitted when salvarsan is being injected, and it is a good general rule to have the first portion of the injection consist of normal salt solution. 6. After the requisite dose has been injected, a few cubic centimeters of salt solution are again permitted to flow into the vein, so that the tubing and needle are washed free from salvarsan, and at no time does the drug come in contact with the tissues. by washing with alcohol. Intravenous Administration of Salvarsan in Concentrated Solution. — While animal expermients have shown us that concentrated solutions of salvarsan are not markedly toxic, the administration of concentrated solutions to persons appears to increase the chances of disagreeable after-effects. This is particularly true if the concentrated solution is injected quickly, which is the natural tendency of the physician when all is working smoothly. In preparing a concentrated solution, 20 c.c. of hot, sterile, freshly distilled water are placed in a small Erlemneyer flask or cylinder and the drug added in small amounts followed by brief shaking, until all has been added and dissolved. The clear solution is now neutralized by the addition of a 15 per cent, solution of caustic soda in exactly the same manner as in the preparation of the dilute solution. The physician must never omit this step', the intravenous injection of a concentrated and acid solution of salvarsan is most dangerous and has resulted in fatalities. the Record, Luer, and Burroughs- Wellcome syringes are recommended. The arm of the patient is prepared as described above and a tourniquet applied, which may be quickly released by the operator with least disturbance. The needle is now passed into a vein, and after a free flow of blood appears the syringe is gently adjusted and the injection slowly made (at least one or two minutes should be required) . Great care should be exercised that none of the solution enters the tissues. The syringe shown in Fig. 139 is particularly well adapted for this work, as it enables the physician to puncture the vein with the syringe containing a small amount of salt solution, and also enables him to wash in a small amount of the same at the close of the operation and thus avoid injecting salvarsan into the tissues. Intravenous Administration of Neosalvarsan in Concentrated Solution.— Neosalvarsan, being less toxic than salvarsan, may be readily administered in concentrated solution. The dose of drug to be administered is dissolved in 20 c.c. of warm, sterile, freshly distilled water in a small cylinder and requires no neutralization. The clear solution is now taken up into a sterile syringe and injected in the manner described above. After-care of the Patient. — In the majority of instances the administration of salvarsan is not followed by unpleasant symptoms. This depends, however, to a considerable extent upon the nervous constitution of the patient. Many persons will complain of a feeling of fullness and may perspire freely for a short time. There may be slight pain at the site of injection and in the axilla of the injected side. As was previously mentioned, salvarsan should be administered at the patient's home or in a hospital, followed by rest in bed until the next morning. When neosalvarsan is injected, robust persons may, after resting for an hour or so, travel homeward. Occasionally severer reactions follow salvarsan administration, and these may be considered under the head of after-effects. After-effects of Salvarsan.— Within an hour or two after its administration arsenic is excreted by the kidneys and bowels and nausea may be complained of. If catarrh of the stomach is present, severe vomiting may ensue. The nausea is relieved by sipping a little hot water; hot applications over the stomach and small amounts of carbonated water or champagne will usually control the vomiting. It may occasionally be necessary to administer y% grain of morphin hypodermically, especially if the patient is of a neurotic temperament. Headache may occasionally develop, and is due to a neurotic condition, constipation, anxiety, hunger, or possibly to an increase in the exudate of the syphilitic process. Diarrhea may be observed in a few cases; this is readily controlled by the administration of bismuth. Chills and fever are more infrequent at the present time, the result probably of using freshly distilled water and somewhat smaller doses of the drug. In some cases an arsenic rash, in the form of an erythema, may follow injection. This is not the Jarisch-Herxheimer reaction, which is found only in syphilis, the arsenic rash having been observed in non-syphilitic persons injected with the drug. There is no evidence to show that salvarsan or neosalvarsan will injure healthy kidneys, although a mild transient albuminuria may follow the injections in some instances. When, however, the kidneys have been damaged by mercury, salvarsan may give rise to an acute irritation, and, indeed, Wechselmann ascribes many of the salvarsan casualties to this condition, and issues the warning that, while mercury may follow salvarsan, it should never precede it. The good general effects following the administration of salvarsan are manifested, as a rule, in a sense of well-being, and not infrequently patients who are anemic, poorly nourished, and despondent in a short time become healthy, active, and cheerful. This may be due in part to a psychic effect, but there is frequently evidence of a far-reaching change in the nutrition of the patient. Reactive Manifestations After the Use of Salvarsan. — The various reactive symptoms which not uncommonly follow the administration of salvarsan or its congeners, have been assigned by different clinical observers to widely diverse causes. The generally accepted views have undergone considerable modification from time to time. At the present day our knowledge of the subject is still imperfect and unsatisfactory. The hypotheses which have been advanced but inadequately explain the phenomena. The subject is particularly complicated because the physiologic and toxicologic effects of a relatively new and extremely complex compound are not accurately known. Dr. Schamberg, Dr. Raiziss, and I1 have devoted considerable time to experimental studies bearing upon the causative factors involved in the production of salvarsan reactions, and the following summarizes our results and views upon this subject: In order that the phenomena developing after the administration of salvarsan may be better discussed we have thought it wise to classify the symptoms into three groups: (a) the immediate symptoms, (6) the early symptoms, and (c) the late symptoms. (a) The Immediate Symptoms.— These phenomena are observed during the intravenous administration of the drug or within a few minutes after the completion of the same. At times patients during infusion of the solution will state that they taste the drug. Inquiry will usually elicit the reply that the taste is like that of ether. A burning sensation of the tongue or lips may be complained of; these are usually the precursor of a train of other symptoms. The first objective evidence of immediate reaction is flushing of the face; this may be slight and transitory, or may be pronounced and accompanied by injection of the conjunctive, lacrimation, edema and swelling of the lips, tongue, and eyelids, an anxious expression of the countenance, nausea followed by vomiting and retching, and this, in turn, by profuse perspiration. In some cases cough, respiratory embarrassment, and dyspnea are observed. The pulse at first is full and bounding, but later slow and of very small volume, in which event it is usually accompanied by a pronounced pallor. In severe cases the patient may lose consciousness and the pulse may be scarcely palpable. In rare instances death has been reported. An urticarial eruption appearing during the congestive stage is one of the more uncommon manifestations, as is also a severe pain in the lumbar region. These symptoms may disappear within fifteen to thirty minutes, and be followed by no other phenomena, or, as more commonly happens, other symptoms, as chills, develop within a brief period or several hours later. This secondary complex we prefer to discuss as group b, as these symptoms not infrequently appear several hours after the injection of salvarsan, even when they are not preceded by the vasomotor phenomena just described. (6) The Early Symptoms. — These symptoms consist of chilliness or a distinct rigor, headache, vertigo, nausea, vomiting, diarrhea, and rise of temperature, usually 100° to 102° F. But few of these may be present and they may be so mild as to merely make the patient feel "queer," or there may be repeated chills, numerous attacks of emesis, and profuse and protracted diarrhea. Occasionally severe pains in the legs and back are complained of. This group of symptoms usually passes off in twelve to twenty-four hours, and is followed by a feeling of lassitude or weakness. More uncommonly vomiting and diarrhea, associated with some elevation of temperature, may continue for a number of days, the patient during this period being unable to retain any nourishment. In some cases the urine may be scanty and contain albumin and casts. days. The most common are urticarial and scarlatinoid and morbilliform erythemas, and in rare cases purpura. In some instances an itching of the skin or pruritus without accompanying eruption has been noted. Most of these eruptions are ephemeral and disappear in a day or two. Later and more persistent eruptions have been observed to occur from six to ten days after the administration of the drug. These late eruptions are more common after intramuscular injection. Some instances of universal exfoliating dermatitis have been reported, persisting for weeks, with fever and debility, and sometimes leading to a fatal termination. (c) The Late Symptoms. — Delayed reactions may come on after twenty-four hours, in which event they usually consist of vomiting, fever, and diarrhea, similar to the intermediate reactions. More rarely serious and even fatal reactions may develop about three days after the administration of the drug. In these cases the phenomena are either referable to the brain or the liver. In the severe cases there may be headache, vomiting, muscular twitchings, epileptiform convulsions, dilation of the pupils, absent reflexes, coma, and death. These symptoms are usually the expression of edema of the brain or of encephalitis hemorrhagica. Meirowsky and Kretzmer,1 in their splendid monograph on the salvarsan therapy of syphilis, present a critical analysis of the fatalities following the use of salvarsan. Of 109 fatal terminations recorded in literature, 41 per cent, occurred in the secondary period and 27 per cent, in late nerve syphilis. Three-fifths of the fatalities during the secondary stage resulted from encephalitis. Forty-five per cent, of these occurred in cases in which the dose exceeded 0.5 gm. Grouping all of the cases of single and multiple injections, 66 per cent, of the cases received doses over 0.5 gm. The size of the dose is, therefore, a most important factor in the causation of encephalitis. The danger decreases in proportion to the duration of the interval between the injections. Another rare syndrome following the administration of salvarsan is characterized by severe jaundice accompanied, as a rule, by fever. This may appear in from three days to several weeks after treatment. Such accidents are much more frequent after intramuscular than after intravenous injections. Most cases of postsalvarsan jaundice pursue a favorable course, but there are exceptional cases which terminate fatally with the symptoms and autopsy findings of acute yellow atrophy of the liver. that there is no single cause that will explain the varied reactive phenomena following the administration of dioxydiamino-arsenobenzol. Indeed, it is possible that the various groups of symptoms may be due to different causes. It will perhaps lead to greater clarity if we classify the causes of reaction under three heads: (1) Factors related to the patient; (2) factors related to the technic of administration, and (3) factors related to the chemical compound employed. 1. Factors Related to the Patient. — There can be no doubt that individual susceptibility plays a part in reactions. Patients suffering from syphilis vary greatly in their physical condition in the degree of functional and organic integrity of the various organs. As a class, too, they are prone to be neurasthenic, and the mental state at the time of injection doubtless influences the incidence of some of the less reactive phenomena. Patients may vary in their psychic response to the operation per se, in the manner in which they react to errors of technic, and their susceptibility to the drug itself. Two individuals may receive a solution of the same drug prepared at the same time, and one may suffer reaction and the other remain free. One of the writers had a striking example of this in his practice. A physician and his patient each received half of the quantity of an alkaline solution of salvarsan from the same mixing cylinder. The physician shortly afterward developed pronounced chills, elevation of temperature to 102° F., and severe pains in the legs; the other patient, contrary to instructions, ate a hearty meal an hour later and took a two hours' train ride to a neighboring city, but suffered no reaction. There can be no doubt, therefore, that the personal element may be a factor in causing or influencing reactive symptoms, but it is, in our opinion, not the dominant factor. 2. Factors Relating to the Technic. — These factors have been given much attention in literature, and different observers have attributed great significance to one or another error of technic. The greatest interest and controversy have attached to the "water error" or "Wasser fehler" of Wechselmann. Wechselmann advanced the hypothesis that water impurities, chiefly bacterial proteins, were largely responsible for the febrile and gastro-intestinal reactions. This view was accepted and indorsed by Ehrlich, Max Miiller, and many others. Yakimoff and Yakimoff showed that the presence of bacteria in the salvarsan solution increased the toxicity to a varying degree, depending upon the type of organisms present. The colon bacillus increased the toxicity most, the Bacillus pyocyaneus less, and other bacteria little or not at all. Gemerich believed that organic contamination of the water by saprophytes was the cause of a number of unfortunate consequences. He believed that certain poisonous substances in the bacteria are not destroyed by boiling, and that they may produce febrile reaction in the patient. Fresh distilled water that did not contain bacterial bodies was less apt to produce fever. Arzt and Kerl, Nobel and Peller, Wachenfeld, and others do not admit the "Wasser fehler" as the cause of fever. Luitheln and Mucha also dissent from this view, and regard the fever as due to a resorption of broken-down cell products; headache, vertigo, and vomiting are also regarded by them as due to this cause. Neisser had previously, in 1910, advanced the view that the febrile symptoms were due to the rapid destruction of innumerable spirochetes and the setting free of endotoxins which reached the blood-stream and induced the symptoms. Emery believed that contamination of the water with copper, leas, or silicates from the distilling apparatus, increased the toxicity of salvarsan and caused reactive manifestations. Gonder, at the request of Ehrlich, carried out on animals some experiments on the toxicity of salvarsan solutions to which small quantities of calcium and magnesium salt, which are commonly found in tap-water, were added. He found that these increased the toxicity of the drug. fusion apparatus in distilled water and not in ordinary water. From this mass of divergent opinions it is difficult to draw any clear and definite deductions. While the "water error" is a factor in reactions, it is probably much less constantly responsible than has been alleged by Wechselmann and others. Many of the factors referred to are doubtless capable of causing fever and gastro-intestinal symptoms in certain patients, but no one of these causes is responsible for the majority of the reactions. There are other faults of technic which may likewise be responsible for reactions, such as the use of too hot or too cold water, too acid or too alkaline solutions, the employment of too small or too great a volume of water, the too rapid infusion of the solution, etc. Then, too, the improper preparation of the patient for the injection or improper after-treatment. The intravenous administration of the drug shortly after the eating of a meal or the partaking of food too soon after the injection may induce gastro-intestinal reactions. Physical overexertion immediately before or directly after treatment may likewise be responsible for reactive phenomena. 3. Factors Related to the Medicament. — We are strongly inclined to believe that in the interpretation of the causes of reactions following the administration of salvarsan (and we are employing this term to indicate dioxydiamino-arsenobenzol, irrespective of the trade name under which it is marketed), too great a stress has been laid upon errors of technic and upon personal factors, and too little attention has been paid to a study of causes related to the compound itself. In order to intelligently discuss this aspect of the question it is necessary to refer to the chemistry of the substance under consideration. Salvarsan is an extremely complex substance, perhaps the most complex drug employed in medicine. Before its final elaboration numerous intermediate products must be prepared. The purity of the final compound will depend to a certain degree upon the character of some of the precedent intermediate substances. Even if these be in a pure state, certain impurities are apt to develop during the process of reduction with sodium hydrosulphite. Salvarsan is precipitated by ether out of a hydrochloric acid methyl alcohol solution of the base; other substances in minute quantities may be precipitated in addition to salvarsan. Inasmuch as salvarsan cannot be purified by repeated crystallization, we cannot regard salvarsan as an absolutely pure compound. A number of analyses made by us corroborate this statement. Salvarsan does not give arsenic values quite up to the theoretic amount, and, furthermore, there are elements present which have no place in the chemical formula. We have found in our analyses that salvarsan contains on an average 1 to 2 per cent, of sulphur; our own product, arsenobenzol, likewise contains sulphur. The sulphur doubtless becomes attached to the arsenic during the process of reduction. Inasmuch as salvarsan is not an absolutely pure chemical substance, the drug in powder form will vary to a slight extent in different lots. Indeed, we doubt whether any two batches can be prepared which are identical in all respects. We have already stated that different serial products vary in their oxidizability. From numerous experiments which we have carried out we are convinced that they also vary to a certain extent in therapeutic properties and to a greater degree in toxicity. Unfortunately, these variations cannot at the present time be determined by ultimate chemical analysis, but only by the biologic effects of the drug. With these prefatory remarks in mind, let us discuss the relation of variations in the drug to reactive phenomena following its use. Ehrlich and his associates have repeatedly called attention to the liability of dioxydiamino-arsenobenzol on exposure to air to undergo oxidation with the production of amino-oxyphenyl-arsenoxid. This arsenoxid might be present in the drug through insufficient reduction, although with care this is not apt to take place. The commercial product always contains some arsenoxid, but it is usually less than 1 per cent. Ehrlich states that the best preparations will contain from 0.5 to 0.8 per cent, of arsenoxid. Ehrlich and Bertheim1 state that the toxicity of arsenoxid is very much greater than that of salvarsan. Like other arseno compounds, the hydrochlorid of dioxydiamino-arsenobenzol possesses the property of readily undergoing oxidation. Exposed to the air it will soon contain amino-oxyphenyl-arsenoxid; indeed, the production of arsenoxid compounds takes place if the preparation is kept in an ordinary glass container. This fact is, therefore, of the greatest importance in the practical use of this remedy, because the amino-oxyphenyl-arsenoxid is about twenty times more poisonous than the pure hydrochlorid of the arseno compound. Variations in the Medicament and their Relation to the Immediate Reactive Symptoms. — We are firmly convinced that the complex of symptoms classed under group a, arid characterized by flushing, edema, etc., and followed by pallor, and in rare instances by syncope, are due to the drug administered and not to extraneous causes. Various descriptive adjectives have been applied to this syndrome, such as vasomotor, angioneurotic, anaphylactoid, and nitritoid. The milder grades of reaction bear a resemblance to the symptoms following the use of nitrate of amyl, and the severer types simulate rather closely the picture of anaphylaxis. Indeed, Swift maintains that they represent true anaphylactic phenomena. Swift2 demonstrated that guinea-pigs which have been sensitized by the injection of a mixture of guinea-pig serum and salvarsan, and have been reinjected after a suitable time with the same mixture, show symptoms like those seen in anaphylactic shock. Swift believes that this phenomenon depends on an alteration of the native serum by salvarsan so that the homologous serum acts like a foreign protein. It is pointed out that the symptoms resembling those of anaphylaxis which at times follow the administration of salvarsan, occur usually not after the first but only after one or more injections. The vasomotor symptoms above mentioned we believe to be due to something in the drug which directly or indirectly (perhaps through anaphylaxis) induces a paresis of the blood-vessels, characterized by dilatation and not infrequently by leakage of the serum into the tissues. We regard these symptoms, therefore, as vasoparetic in character. We do not believe that these symptoms are due to the pure molecule of the hydrochlorid of dioxydiamino-arsenobenzol. From various experiments which we have carried out we strongly suspect that they are produced by traces of an impurity in the drug. We have devoted much study to discover the particular substance which gives rise to these symptoms, but thus far our efforts have not been attended with success. We shall therefore in our discussion refer to this substance as substance X. Different lots or batches of dioxydiamino-arsenobenzol (salvarsan or its congeners) vary in respect to the frequency with which they induce the immediate vasomotor or vasoparetic reactions. Experienced clinicians, we are sure, will agree that few or no reactions of this character occur after the use of certain lots of the drug, and, on the other hand, other batches seem to be followed by an unusual incidence of such reactions. To be sure, not all patients will exhibit vasoparetic reactions after the use of a poor product, nor will all remain free of these reactions after the employment of a relatively pure product. There are, doubtless, variations in susceptibility to substance X, and some patients will react against the minutest quantity, while others will do so only in the presence of a large amount. It is a common experience for patients to repeatedly exhibit vasoparetic symptoms after salvarsan and yet remain free of such phenomena after the use of neosalvarsan ; the formaldehyd-sulphoxylate group in this compound is attached to the amino radical, and the process which is employed seems to lessen the formation of substance X. The Jarisch-Herxheimer Reaction. — This reaction manifests itself in the development of a rash, the extension or aggravation of an existing eruption, or an inflammatory reaction in any syphilitic tissue the result of treatment. It has been observed in the course of mercurial treatment, and before the discovery- of the Spirocheta pallida and the Wassermann reaction it was regarded as of considerable diagnostic importance. Any aggravation of syphilitic symptoms following the administration of salvarsan or mercury has been interpreted as a Herxheimer reaction. The cutaneous reaction is manifested by edema, redness, pain, and the mucous patches show a similar reaction. Gummas become swollen, may ulcerate, and show increased exudation. The lancinating pains of locomotor ataxia may be augmented, and various paralyses, due to pressure, may follow in those nerves that traverse bony canals. These effects are also known under the name of neurorelapses. They usually appear two or three months or even four or five months after treatment, and they were at first believed to be due to the contained arsenic and were regarded as constituting a special danger attending the use of salvarsan. Various explanations for this phenomenon have been offered: Ehrlich believes that it indicates failure of the injected dose to produce complete destruction of the spirochetes, with temporary stimulation of the microorganisms to increased multiplication and activity. He very pertinently compares the neurorelapse or Herxheimer reaction to the extensive development of individual bacterial colonies on agar plates, when but few microorganisms are present, as contrasted with their small size when the number is large. The so-called provocative positive Wassermann reaction may be considered as a part of this reaction. INTRAMUSCULAR INJECTION As was previously stated, this route of administration is not generally employed at the present time because of the local irritative effects of salvarsan especially. When slow absorption and elimination are desired, or when intravenous injections are impossible, as in the case of very young children, this method may be adopted. When salvarsan is to be given, the clear, concentrated alkaline solution is generally used. Neosalvarsan is to be preferred, because it is less irritating than salvarsan. It may be given in a concentrated aqueous solution or suspended in sterile oil with the addition of a local anesthetic, such as eucain or creosote, after this formula: Salvarsan, 0.4 or 0.6 gm.; creosote (beechwood), gtt. ij ; sterile liquid petrolatum, 5 c.c. Mix well in a sterile mortar. The injections are made, under strict antiseptic precautions, in the gluteal region, into the upper and outer quadrant of the muscles. The syringe and the needle should be sterilized and the injection prepared. After cleansing the skin with alcohol the needle is quickly and boldly plunged into the deep tissues. The syringe may then be detached to ascertain if blood flows, which would show that a vein has been punctured and require a reinsertion; if blood does not appear, the barrel should be reattached and the injection slowly given. Intraspinous Injection of Neosalvarsan. — Owing to the fact that a drug injected intravenously may not reach the tissues of the central nervous system, salvarsan and neosalvarsan have not fulfilled the early expectations, apparently chiefly for the reason that they cannot reach the spirochetes. It would seem, therefore, that adequate treatment of syphilis of the central nervous system consists in the direct application of the remedy to the infected tissues themselves. Wechselmann l and Marinesco 2 have injected salvarsan, and Marie and Levaditi 3 and others have given neosalvarsan, directly into the spinal canal. The results, however, were either dubious or frankly dangerous, and the injections were followed by severe and alarming symptoms, due mainly to the production by the drug of direct irritation upon the sensitive nervous system. Ravaut1 has found that the use of hypertonic solutions of neosalvarsan are better borne and of value in the treatment of special cases. Wile 2 has also employed this method, and has found it of some value in cerebrospinal syphilis. Tabetics presenting no bladder or rectal symptoms were found to do especially well. As is to be expected, the earlier the treatment is instituted, the better are the results. This form of treatment is, however, to be regarded as dangerous, and is to be used only in selected cases, and with a full understanding of the risks incurred. Wile has given the following technic : "The solution used for injection consists of a 6 per cent, solution of neosalvarsan in distilled water. This solution is hypertonic, and made of such concentration that each minim must contain 3 mg. of the drug. The dosage injected is from 3 to 12 mg. — that is, from one to four drops of the solution, which is made up as follows: "An ampule containing 0.3 mg. of neosalvarsan is dissolved in 5 c.c. of freshly distilled water. If the ampule contains 0.6 gm., 10 c.c. of water are used. In both solutions each drop will contain 3 mg. of the drug. The syringe employed for the injection is accurately graduated in drops. The patient is placed in a position for lumbar puncture, either sitting or lying, according to the choice of the operator. The puncture is then made with the needle, the end of which fits the graduated syringe. After a few drops of the spinal fluid have flowed out of the cannula, or a greater quantity if a diagnostic puncture is desired at this time, the syringe is fitted into the needle, and the fluid is allowed to run back into the syringe barrel, thus mixing with the amount of the drug in the barrel. The mixed spinal fluid and drug are then gently forced into the canal, and slight suction is made on the syringe to withdraw a second amount of fluid, which washes out the needle. This is then reintroduced, the needle is quickly withdrawn, and the patient placed in the Trendelenburg position, in which position he is allowed to remain for at least one hour." INTRASPINOUS INJECTION OF SALVARSANIZED SERUM In this method the salvarsan or neosalvarsan is injected intravenously in the usual manner, and shortly afterward blood is withdrawn, the serum separated, heated to 55° C. for half an hour, and a portion injected intraspinously. In this technic, which has been worked out largely by Swift and Ellis, the drug is highly diluted, and therefore is not likely to produce much irritation. In addition, some of the good effects may be due to the presence of antibodies in the serum itself. This method constitutes the most useful form of intraspinous medica- Mention has also been made, in the preceding chapter, of a method of intraspinous medication consisting in the injection of a combination of the patient's serum and salvarsan or neosalvarsan mixed in vitro. This method is to be regarded as more dangerous and probably less efficient than that of Swift and Ellis, and as yet in the experimental stage. Recently Fordyce * has given the following technic (Ogilvie) : "Fifty c.c. of blood are drawn into a centrifuge bottle and centrifuged twice. It is important to have the serum clear and free from fibrin and blood-cells. To obtain the requisite amount of the drug old salvarsan is mixed in the usual way, in the proportion of 0.1 gm. to 40 c.c. of fluid, care being taken not to overalkalinize; 0.4 c.c. of this solution is the equivalent of 1 mg., and is taken as the standard for measuring the dosage. For this purpose a 1 c.c. pipet graduated in hundredths should be employed. The desired amount of salvarsan is added to from 12 to 15 c.c. of the serum, shaken to and fro to mix thoroughly, and then placed in the incubator at 37° C. (98.6° F.) for one hour, after which it is inactivated for half an hour at 56° C. (132.8° F.). The latter is the most important step in the technic; the spirocheticidal properties of the serum are markedly increased by heating. "Salvarsanized serum, prepared according to this method, must be used fresh, that is, within three hours of the time that it is made up. Patients should be prepared for its administration as for intravenous injection, with a laxative the night before and only a light meal two hours prior to the treatment. "A lumbar puncture is made, and an amount of fluid equivalent to the amount introduced is withdrawn. While the needle is in situ, the barrel of a Luer syringe is connected by means of a piece of rubber tubing. Spinal fluid is allowed to fill this to expel the air, and the serum is then permitted to flow in by gravity. After its administration the patient should lie flat without any pillows, the foot of the bed being kept elevated for several hours. He must be kept in bed for at least twentyfour hours, in some cases forty-eight or seventy-two hours. Failure to do this may result in unpleasant symptoms, as pain in the extremities, headache, anesthesia, and bladder and rectal paresis." The proper dose is still a matter of doubt, and a note of warning must be sounded against employing too large amounts. Fordyce believes that the limit of safety lies within 0.5 mg. It is better to begin with a dose of 0.25 mg., repeating or gradually increasing this according to the tolerance of the patient. The intervals between doses should be two weeks or longer. In the treatment of syphilis of the central nervous system the intravenous method may first be tried, giving a series of six or eight injections of salvarsan, beginning with a dose of from 0.25 to 0.3 gm., and injecting it at intervals of from one to two weeks. At the end of this time the blood and spinal fluid should be tested, and if it is found that 1 Jour. Amer. Med. Assoc., 1914, Ixiii, 552. a course of intraspinous injections may be considered. CONTRAINDICATIONS AND PRECAUTIONS IN SALVARSAN THERAPY When it is remembered that millions of doses of salvarsan and neosalvarsan have been given by thousands of different physicians, by many and diverse methods, the relative safety of the drug is apparent. The fact remains, nevertheless, that patients have succumbed soon after receiving an injection who would not otherwise have died at that time. Recently Wechselmann1 has reviewed the deaths following salvarsan therapy and has arrived at the conclusion that "insufficiency of the kidney, and not hyper sensitiveness of the brain, is the point of the entire question of salvarsan fatalities. " He is very emphatic in warning against mixed mercurial and salvarsan treatment, especially if salvarsan is given after a course of mercury, for the latter drug is a renal irritant and may lead to prolonged retention of the salvarsan, which may undergo a process of reduction in the tissues and form one of the poisonous products that Ehrlich has called "arsenoxid." main groups: 1. Those to whom the injection may be dangerous on account of the reaction that may follow, as, for example, cases of early cerebral lues with cranial nerve manifestations of an exudative character; also cases of tabes with beginning optic atrophy. In these patients salvarsan or neosalvarsan should be given with extreme caution and only in small doses, and frequent examinations of the eyes should be made. 2. Those with extensive disease of the circulatory system, such as severe uncompensated heart disease, coronary sclerosis, and extensive aneurysm; also cases of diabetes mellitus, severe nephritis, ulceration of the stomach, and advanced tuberculosis or carcinoma. In this connection I may cite here the precautions laid down by Wechselmann, director of the dermatological department of the Rudolf Virchow Hospital, in whose clinic over 25,000 doses of salvarsan have been given. These precautions are: 4. The conjoint use of salvarsan with heavy mercurial treatment is dangerous! If one will use the combined treatment, then let him give mercury very carefully many days after giving the last salvarsan injection, but he should not reverse this rule. It is too soon to judge of the ultimate value of salvarsan in the treatment of syphilis. It may be stated, however, that the immediate effects are so beneficial that the drug is to be regarded as the best we possess for the treatment of lues. As is to be expected, the best results are secured when the remedy is administered early, and, of course, when tissue changes have occurred no drug can be expected to restore a lost function, although it may bring about considerable improvement by causing the disappearance of syphilitic tissue. In long-standing cases salvarsan may, at least, hold the symptoms in abeyance, and effectively prevent progress of the disease. It is especially valuable in patients who cannot tolerate mercury. The remarkable efficacy of salvarsan is attested by the rapidity with which spirochetes disappear from primary sores and from secondary lesions, the manner in which they disappear being frequently little short of marvelous. There can be no doubt but that salvarsan is a powerful spirocheticide, having but remarkably little toxic effect upon the body-cells. It would appear that in order to rid the tissues of the spirochetes it is only necessary to bring the drug into contact with them. For this reason newer and better methods of administration are bound to increase the value of the drug. Barring the wellrecognized contraindications, salvarsan may be used in practically all stages of the disease. In the later stages of the infection, in which the central nervous tissue is involved, the physician must bear in mind the possible danger of a neurorelapse or a Herxheimer reaction occurring. While salvarsan may do no good in late cases, since it cannot restore lost nerve tissue, it may alleviate symptoms and prevent progress of the in- fection. In the treatment of any case of syphilis the best results are not secured from following any course of treatment according to a rule of thumb; they are obtained only by a suitable combination of expert clinical knowledge and training in serologic technic. All possible aid should be enlisted in the treatment of the disease. It is beyond the scope of this book to present either case reports or a lengthy discussion of salvarsan in the treatment of the various stages of syphilis; suffice it to say that, in the absence of contraindications, the drug may be administered whenever living spirochetes are present in a patient's tissues, as evidenced either by clinical symptoms or a positive Wassermann reaction. The method of administration selected should be that which will best bring the drug into contact with the diseased tissues. In the studies of Schamberg, Raiziss, and I1 upon the chemotherapy of mercurial compounds as compared with salvarsan, salvarsan has shown itself to be by far the most powerful trypanocide known in both the living animal and in the test-tube. In my in vitro-vivo method2 it destroys trypanosomes in dilution as high as 1 : 40,000. Bichlorid of mercury shows markedly inferior values in this respect. The superiority of the influence of salvarsan over mercury in experimental trypanosomiasis is incontestable. In the test-tube salvarsan exhibits a greater destructive influence on animal parasites, and mercury a greater destructive influence on vegetable parasites. SALVARSAN IN THE TREATMENT OF NON-SYPHILITIC DISEASES While salvarsan therapy has achieved its greatest success in the treatment of syphilis, its influence on certain non-syphilitic diseases has been so pronounced that it is being used in an ever-increasing number of diseases, the aim being to thus enlarge its sphere of usefulness. A recent systematic study of the subject has been made by Best.3 Good results have been reported by various observers in the following diseases : Frambesia (Yaws). — The results achieved in this disease from the use of salvarsan have equaled those obtained in syphilis. Two thousand four hundred and thirty cases have been reported, a cure having been effected in all but a few instances. Since the use of salvarsan has come into favor hospitals for the treatment of frambesia have been closed. CHEMOTHERAPY IN BACTERIAL DISEASES 881 Relapsing Fever. — In the treatment of this disease the drug has likewise had a remarkable effect. Of 195 cases reported, in most of them the microorganisms could not be found in the blood after an injection, and in none of the cases were relapses observed to occur. Filariasis. — Salvarsan has been found effective in killing the Filaria sanguinis hominis and in ridding the blood of these parasites. Of course, in elephantiasis it is impossible to restore the affected parts to their normal appearance. Vincent's Angina. — An immediate improvement and rapid healing have been reported as following either an intravenous injection or the local application of the drug in the form of a dusting-powder or in suspension in glycerin. Duhring's Disease (Dermatitis Herpetiformis), Scurvy, Chorea, Malaria, Acanthosis Nigricans, Ulcus Tropicum, Variola, and Verruca Plana. — In all these affections salvarsan has been found to exert a beneficial and curative effect, either by direct action upon the microorganisms present or as the result of the alterative and stimulating effect of the arsenic. In Aleppo boil, leprosy, lupus vulgaris, tuberculosis, anemia, keratosis follicularis, lichen planus, mycosis fungoides, pellagra, and pityriasis rubra, good or indifferent results have been reported. In many conditions it would appear that salvarsan exerts a direct germicidal effect, and in others the beneficial results appear to be dependent upon a certain tonic, stimulating, and alterative effect of the arsenic. In chancroid, scarlet fever, Hodgkin's disease, psoriasis, trichinosis, and trypanosomiasis the drug does not appear to exercise any influence, which is due probably, in the last-mentioned disease, to the fact that trypanosomes are much more likely to become arsenic-fast than are the spirochetes. Principles. — The ultimate aim in bactericidal chemotherapy is the discovery or the rational and systematic development by synthesis of a substance that is strictly monotropic ; that is, one possessing a selective affinity for the protoplasm of a particular microparasite and exerting a specific killing effect on that organism. Thus far this desideratum has not been achieved ; as even arsenobenzol (salvarsan) is not strictly parasitotropic for Treponema pallidum, but possesses also a marked parasitropism for other spirochetes and other protozoa, notably various are markedly bacteriotropic or protozootropic in general constitutes an important advance, the ultimate aim, as stated, should be the synthesis of a strictly monotropic substance. It is suggested that further studies with arsenobenzol, tending to increase its parasitotropic effect on spirochetes alone and Treponema pallidum in particular, will still further increase the therapeutic efficacy of this drug. "Leads" in Chemotherapeutic Research. — In the present state of our knowledge of chemotherapy chance or accidental discovery must play an important role in the discovery of a "lead." Substances are to be selected or prepared on as systematic a basis as possible, and tried out by actual experiment; those yielding encouraging results are then subjected to various systematic modifications with experimental trial of the new compounds. In this manner chemotherapeutic research proves to be costly and laborious, as amply demonstrated by the prolonged and costly series of experiments directed by Ehrlich, which resulted in the discovery of arsenobenzol. In the discovery of leads and the study of new compounds animal experiments are of primary importance, not only because these are the sole means of determining the organotropic or toxic effects of the compounds, but because they are the sole means of determining the actual parasitotropic or therapeutic effects. In conducting these experiments it is necessary to select a protozoon or bacterium that yields a uniform infection of the animals of not too severe a character, and to reproduce as far as possible the same lesions in the animals as are found in man. The test microparasite should either produce definite lesions easy of detection and study or cause the death of the animal in a given period of time. For studies in bacterial chemotherapy virulent cultures of the pneumococcus are admirably adapted to work with mice and rabbits; in studies of protozoa Trypanosoma equiperdum or T. brucei is valuable, the white rat being used as host. These experiments, however, are likely to prove costly, and, as in the «ase of tuberculosis, it may be many weeks or months before results can be determined. Furthermore, special animals, such as monkeys or the higher apes, may be necessary for the determination of the parasitotropic effect of a substance, as in the case of anterior poliomyelitis and syphilis, in which the particular microparasites fail entirely to infect such animals as rabbits, guinea-pigs, and rats, or, at least, fail to do so with sufficient uniformity. In chemotherapeutic studies in syphilis the rabbit may be employed, although the infection usually pursues in this animal a brief course tending to spontaneous recovery. For these reasons an effort should be made to train or adapt a race of the particular microparasite under study to survive and multiply in the tissues of an animal easily obtained and handled, so that the abundance of experimental material needed in chemotherapeutic studies on a large scale may be available. In addition to this, as stated, an effort should be made as far as possible to reproduce in the experimental animals lesions similar to those found in man. For example, the effect of a drug in the blood of a rabbit or white mouse in a pneumococcus bacteremia must be different from that in the exudate of a consolidated lung in pneumonia of man. The Role of Bactericidal Tests in the Living Animal in Bacterial Chemotherapy. — In chemotherapeutic studies on syphilis experience has shown that a trypanosome may be used, as Trypanosoma equiperdum, or a spirochete other than Spirochseta pallida, as S. gallinarum, to determine the parasitotropic effect of new compounds as they are produced; because those compounds showing marked effects on these microparasites, as, for example, arsenobenzol, also produce a profound effect on S. pallida in human and experimental syphilis. It remains to be determined, however, whether similar conditions hold true in the chemotherapy of bacterial infections; that is, whether a compound showing a high bactericidal effect in vitro, or even in vivo, on one microorganism, as Bacillus typhosus or the pneumococcus, will show a similar effect on the microorganisms of other diseases, as tuberculosis or anterior poliomyelitis. Suffice it to say that the ultimate value of any drug can be determined only by tests in the lower animals; first to determine toxicity, and then therapeutic value. If these tests show a low toxicity and a promising therapeutic effect the court of last resort is the use of the compound in the treatment of man. The Role of Bactericidal Tests in Vitro in Bacterial Chemotherapy — In chemotherapeutic studies on bacterial infections experiments in vitromay be said to have a positive value in preliminary orientation in the development of leads and the study of new compounds as they are produced. Experimental data at hand tend to show that substances possessing a high bactericidal activity in vitro, and particularly in a menstruum of fresh sterile serum, are more likely to exert an inhibitory effect invivo; for example, Morgenroth's drug, optochin (ethylhydrocuprein) and its hydrochlorid, exert a very high bactericidal action on the pneumococcus in vitro, and are likewise effective to some extent in vivo; other cinchona, derivatives, including certain salts of quinin, possessing more or less bactericidal value in vitro are likewise effective to a certain degree in. vivo.1 Arsenobenzol has been found to possess the highest parasitotropic 1 Jour. Infect. Dis., 1917, 20, 81. activity on Trypanosoma equiperdum in vitro of a number of substances tested,1 and, as well known, this drug exerts the best therapeutic or parasitotropic effects in vivo. Unfortunately, however, other substances that are highly bactericidal in vitro, as the mercurials, also possess a high degree of toxicity for the living animal, and all efforts of the chemotherapeutist have so far failed to lower materially the toxicity of these compounds. Since the time of the earliest discoveries in bacteriology and of bactericides substances highly bactericidal in the test-tube have been known to fail to exert any appreciable influence in vivo when given in safe doses. This lack of effect may be due to the high organotropic or toxic effect of the substance on the body cells in general or on a particular group of cells of vital centers, precluding the use of a bactericidal quantity; to insolubility and difficulty of administration; to rapid union with the proteins of the body and the formation of inert compounds; to rapid elimination; to failure to reach the microorganism in a lesion, and to still other causes. Of these possibilities, the first mentioned is of primary importance; but the method and manner of attack of the bactericidal drugs on the protoplasm of cells, aside from coagulation, is almost unknown. Nevertheless, it is possible by systematic modification of the molecule through addition, removal, or substitution of certain atom groups, to produce in some instances a sufficient lowering of toxicity to give an available therapeutic agent. The demonstration of this fact constitutes the great triumph of Ehrlich and opens a fascinating field of research to chemist and biologist. It is highly probable that experimental studies tending to increase the monotropism of a drug in vitro and particularly in a menstruum of serum will prove of value in chemotherapeutic work. For example, ethylhydrocuprein, which shows the highest selective action upon the pneumococcus in vitro, likewise proves mos btactericidal in vivo. Similar facts may be proved in the future in connection with the microparasites of tuberculosis and of typhoid fever, staphylococci, and other infective bacteria. On the other hand, a substance failing to exert parasitotropic action either in vitro or in vivo may still prove of value as a basis of composition, and offer a valuable lead in chemotherapeutic research. For example, arsenic in the form of the trioxid has no appreciable effect on Trypanosoma equiperdum in vivo and but slight effect in vitro,2 and yet it forms the basis of arsenobenzol, which is so highly parasitotropic both in vitro and in vivo. Likewise, it is possible that a chemical may be more efficacious in vivo than in vitro by reason of the formation of new and more active compounds in vivo] or by exciting the body cells to produce antibodies for the parasitic antigen or chemically facilitating such production; or by the stimulation of phagocytosis, as suggested by some of our experiments in the case of quinin compounds in pneumococcus infections.1 Still, as a general rule, it appears that substances without appreciable effect in vitro are likely to be similarly inert in uivo. Arsenobenzol offers no exception to the rule; contrary to the general impression, it possesses a marked trypanocidal activity in vitro. It is highly probable, therefore, that experiments in vitro have a definite value in chemotherapeutic research as methods of preliminary orientation and in the development of monotropic chemicals. This value is greater when the identical microparasite causing the definite infection under study is employed in the tests. In the absence of a pure culture of the particular microparasite against which a destroyer is sought, or in the presence of insuperable technical difficulties, other and more easily cultivated organisms closely or remotely related, or even of a different biologic order, may be employed, as in the use of Bacillus typhosus and other bacteria by Jacobs and his colleagues2 in chemotherapeutic studies concerning anterior poliomyelitis. Pneumococcus Infections. — As has previously been stated in Chapter XXIX, progress in the chemotherapy of pneumococcus infections has been made by Lamar in the treatment of pneumococcus infections with mixtures of pneumococcus immune serum, sodium oleate, and boric acid. Particularly valuable work in this field has been done by Morgenroth and his associates. Influenced less by this tradition than by the effects of the use of quinin compounds as observed in experimental trypanosomiasis, and by the fact that certain peculiar biologic relationships (as bile solubility) have been found by Schilling3 and Neufeld4 to exist between trypanosomes and spirilla, on the one hand, and pneumococci on the other, Morgenroth and Levy5 chose quinin and its derivatives as a basis and lead for chemotherapeutic studies on experimental pneumococcus infections. Best results were observed with optochin (ethylhydrocuprein), a synthetic derivative of hydroquinin (methylhydrocuprein), which latter exists in the cinchona bark or can be prepared synthetically. In experimental infections of mice the new drug (optochin) was found to prevent the development of infection in some 90 per cent, of animals in which treatment was postponed till after inoculation. Later Guttman,1 Morgenroth and Kaufman,2 and Levy3 reported further experiments indicating the protective and curative action of ethylhydrocuprein (base) and its hydrochlorid in experimental infections in mice. Wright4 found that the administration of ethylhydrocuprein to man resulted in an increased bactericidal power of the blood. These observations were confirmed by Moore5 with animals. Moore6 also reported that ethylhydrocuprein exerts a well-marked protective action against experimental pneumococcal infection in mice in the case of type strains of all four groups of pneumococci; this protective action was found efficient against many multiples of the minimal lethal dose. Rosenthal7 gives an excellent review of the literature bearing on the chemotherapeutic treatment of pneumonia, leading up to and including the work of Morgenroth and Levy and others. Cohen, Heist, and I8 found that in mice the intravenous injection of ethylhydrocuprein hydrochlorid in amounts ranging from 0.02 gm. and higher per kilo of body weight affords complete protection against 50 minimal lethal doses of pneumococci given two hours later by intraperitoneal injection. Doses ranging from 0.01 to 0.006 gm. afford partial protection. Among rabbits a dose of at least 0.01 gm. of ethylhydrocuprein per kilo of body weight is required to afford protection against fifty minimal lethal doses of pneumococci given two hours later by intravenous injection. Clinically, the local application of a 1 to 2 per cent, solution of ethylhydrocuprein hydrochlorid has been reported by a number of ophthalmologists as efficacious in the treatment of pneumococcus ulcers of the conjunctiva and cornea, though somewhat irritating. Zentmayer9 has recently reported very favorably upon the treatment of pneumococcus infections of the eye, and particularly corneal ulcers with daily applica- 3 Berl. klin. Wchnschr., 1912, 49, 2486. 4 On Pharmacotherapy and Preventive Inoculation Applied to Pneumonia in the African Native, 1915. (This little book gives a complete account of the investigations of the author and his associates with ethylhydrocuprein and vaccines in human pneumococcus infections.) tions of a 2 per cent, solution of the hydrochloric! and the hourly instillation of a few drops of a 1 per cent, solution into the conjunctival sac. In the treatment of lobar pneumonia the consensus of opinion would seem to indicate that the drug is not of proved value, and particularly must care be exercised in the dosage to avoid the amblyopia which has been reported by a number of investigators. The general statement is made that there is but "a small interval between the therapeutic and the toxic dose." Tuberculosis. — Koga1 and Otani2 have recently reported favorably upon the treatment of tuberculosis in persons and experimental animals with a substance called cyanocuprol. Takano3 observed beneficial results in the treatment of 6 cases of leprosy with the same substance. Lewis4 has worked extensively with new synthetic compounds largely by tests in vitro; De Witt,5 in summarizing the results of chemotherapeutic studies in tuberculosis, concludes that the results so far with compounds of iodin, arsenic, copper, gold, mercury, and most of the dyes have been in the main negative. It is to be hoped, therefore, that further researches will result in the discovery of substances that have a marked bactericidal action and that are yet but slightly, if at all, toxic for the body cells, that is, substances in which bacteriotropism greatly exceeds organotropism. It would appear that this discovery is possible and probable, but it can be accomplished only as the result of persistent and prolonged research. Probably the most wonderful discovery possible in medicine would be a specific remedy for tuberculosis, and this may be within the realms of chemotherapy. Brief mention may be made of certain recent advances that have been made in the experimental chemotherapy of cancer in the rat and mouse. While the pathogenesis of malignant disease is still unknown, specific therapeutic measures of this kind have been undertaken on the assumption that the cancer-cell is different from the normal cell from which it originated, and that certain substances will show a selective affinity for them; in other words, that specificity may be present among organotropic substances. Here, of course, the difficulties are great, because the structural, biologic, and functional differences between the normal cell and the cancer cell may be slight, and substances must be found that possess a high affinity for the cancer-cell only. That this condition may indeed exist has been indicated by the experiments of Wassermann and his collaborators. These investigations were based upon the discovery, by Gosio, that sodium selenate and sodium tellurate are more rapidly reduced by cancer-cells than by normal cells, and that this reduction takes place within the bodies of the cells. Experiments on mouse tumors showed that the injection of these substances into the growths may actually lead to their destruction, the explanation, according to Neuberg and Caspani, being that certain compounds of the heavy metals in colloidal form favor self-digestion (autolysis) of the tumor cells. The problem now resolved itself into finding some substance that would carry the metals to the tumors, or, as Wassermann said, "the building of rails which would reach the tumor and by which the selenium could travel," as local injection was obviously out of the question from the practical standpoint. Eosin, being a substance endowed with great powers of diffusion, was selected for the purpose, and a number of eosinselenium compounds were tried out. The results were encouraging, as in a number of instances the tumors became soft and sloughed away or their further growth was checked. "If three consecutive daily intravenous injections of the eosin-selenium compound are given in 2.5 gin. doses for 15-gram mice, a distinct softening and elasticity of the tumor are noticed on the fourth day; on the fifth day a fourth injection of the same dose is given, after which there is no longer the feeling of a solid tumor, but rather that of a fluctuating cyst in which small, movable tumor particles can be discovered. After the fifth injection on the seventh day this soft mass becomes smaller, the capsule becomes lax, and the configuration of a circumscribed tumor can no longer be distinguished, but only a long edematous cord can be felt. Usually, as a result of the sixth injection, in favorable cases, the absorption and diminution proceed so that one gets the feeling of an empty sac. In ease no intercurrent disease occurs, the animal is cured in about ten days, with a disappearance of all remnants of the tumor." As these results were observed after intravenous injection of the mixtures, and as no injury to the body-cells was apparent, it seems that a step forward has really been taken; at least, these investigators have shown that it is possible for chemical substances to pass from the blood and attack tumor cells. Copper and tin have been found to possess a more marked affinity for tumor cells, and the whole subject is probably just at the threshold of further discoveries that may be applied with great benefit to the treatment of human malignant disease. In a recent review of the whole subject Weil1 has concluded that when the results are viewed and studied in a critical manner, it is apparent that none of the various methods of treatment advocated so far can lay claim to therapeutic effectiveness. According to Weil, the demonstrable reduction in the size of a tumor, of a kind not to be attributed to the natural processes of evolution of that tumor or of its associated lesions, is the one essential feature of effective therapeutic intervention. Methods. — The exercises and experiments herein outlined are for the purpose of teaching the principles of infection and immunity by actual laboratory work, whereby the student performs the experiments and is taught to observe the results. At the same time a knowledge of the technic of immunologic methods is obtained. The instructor in charge of such an experimental course may choose certain experiments in outlining a course according to the allotment of time and purpose of the instruction. In all instances I have outlined the experiments according to average conditions. It is readily understood that differences in the virulence of a certain culture or the weight and physical condition of an experimental animal will require that the doses advised be changed to meet the conditions. As a general rule, a course should be concentrated, with exercises at least three times a week in order that the student may follow his work closely and have an opportunity for making adequate and accurate observations. AJI attempt is made to bring out the important points of an experiment by a few pertinent questions. It should be impressed upon the student that the mind should be held open for observation and that unexpected and untoward results may be obtained which, however, are always of interest and always instructive when the experiment is conducted in a careful, methodical, and conscientious manner. Frequent general discussions should be held for a general review of the subject and correlation of facts and observations. In my experience students are eager for the work and seldom fail to suggest additional work in the nature of original research. The Student. — 1. The student should work protected by an apron or gown with short sleeves; he should be careful of the hands and avoid abrasions and cuts and carefully wash and disinfect the hands after the work of each day has been completed. ACTIVE IMMUNIZATION OF ANIMALS 891 2. The working table should be set in order after each day's work; pipets and soiled glassware should be properly disposed of, instruments thoroughly cleansed, and the table wiped off with 1 per cent, formalin solution. It should be impressed upon the student that good and accurate work is seldom done amid disorderly and dirty surroundings. practice. Records. — Each worker should record in writing in a suitable notebook his observations of the various tests and experiments. Not infrequently unexpected results are obtained, and it is important to understand and explain these as correctly as possible. Note-books should be subject to frequent inspection; it is not necessary to write out a description of the technic, but the results of the experiment and answers to the questions should be set forth clearly and with sufficient detail. Animal Experiments and Autopsies. — In all experiments calling for operative procedure an anesthetic is to be used in order that unnecessary pain be avoided. Ordinarily, ether is to be employed, or in rabbits the rectal injection of 0.5 to 1 gram of chloral hydrate dissolved in 5 to 10 c.c. of water. Autopsies are to be carefully conducted, and the lesions described in writing. After autopsy the table is to be scrubbed and cleansed with a solution of formalin, and the carcass disposed of by incineration or placing in a solution of formalin until removed and otherwise disposed of. cent, phenol in sterile ampules. While these various immune serums are being prepared the student is engaged with the work on infection, or if the subject of immunity is taken up at once, immune serums should be furnished by the instructor. 1. Grow a virulent culture of pneumococcus in glucose serum broth for fortyeight to seventy-two hours at 37° C. until a good rich growth is secured. Prepare and stain smears by Gram's method. 2. Pass a large catheter which has its tip cut off into the trachea of a dog until it has passed into one of the primary bronchi. By means of a syringe inject quickly 15 c.c. of culture; remove the catheter and mouth-gag. Take the rectal temperature and leukocyte count previous to inoculating. 5. Observe all animals for forty-eight hours, taking the rectal temperature night and morning. Make leukocyte counts every four hours during the day. Make physical examination of the chest. 10. Remove consolidated portions of lung and place in 5 per cent, formalin. After twenty-four hours, cut sections which are passed through by the paraffin method and stained with hematoxylin and eosin, methylene-blue, and Gram's stain. (d) Does the animal receiving the smaller dose of pneumococci intrabronchially show evidences of pneumonia? If not, why not? Does this show a numerical relationship of bacteria to infection? (h) Did the dog receiving the pneumococci intravenously show evidences of pneumonia? Does this bear any relation to the question of the route of introduction of bacteria to infection? (i) Are the pneumococci seen in the smears of the lesions and blood encapsulated? If so, what is the significance of these capsules? Compare these cocci with those shown in the smear of the culture before injection? Are the capsules lost in the artificial culture-media? characteristic edema about the site of injection. 6. After death perform a careful autopsy, paying particular attention to the bloody edema at the site of injection and marked hyperemia of the suprarenal glands. Make cultures on Loeffler's blood-serum medium of edematous area, peritoneum, and heart blood. OF DIPHTHERIA BACILLI 1. Make a culture of a patient harboring the bacilli on a tube of Loeffler's serum medium. Inoculate at 35° C. for from eighteen to twenty-four hours; prepare a smear and stain with Loeffler's methylene-blue. If diphtheria bacilli are present, they must be isolated in pure culture. Never attempt a guinea-pig test with an impure culture. 4. Incubate at 35° C. for three days, keeping the tube in a slanted position in order to give the culture as much oxygen as possible. If a good growth does not appear in twenty-four hours, transplant to another tube of bouillon until the bacilli have been "educated" to grow on the medium. 5. Examine for purity. Select a 250- to 300-gram guinea-pig and inject 2 c.c. of the unfiltered culture in the median abdominal line. Annuals over the weight specified are more resistant and less reliable for test. The unfiltered culture is used, since toxin is but one element of the disease-producing power of diphtheria bacilli, and toxin production in bouillon may not be a true index of the toxin production in mucous membranes. glands is present. 8. Not infrequently animals showing mild or even an absence of the symptoms of toxemia develop paralysis of the hindquarters two or three weeks later. According to Ehrlich, this paralysis is due to the action of "toxon," a toxic substance secreted, by the bacillus or, as believed by others, a modified form of toxin. 9. To prove that diphtheria was the cause of the toxemia or death, mix 2 c.c. of the culture in a test-tube with 1 c.c. of diphtheria antitoxin (500 units). After standing aside for an hour at room temperature, inject the mixture subcutaneously in the median abdominal line of a 250- to 300-gram guinea-pig. Tetanus toxin is composed of two distinct poisons of different properties. One, tetanospasmin, has a great affinity for the central nervous system, and is largely responsible for the symptoms of tetanus infection (neurotoxic) ; the second, tetanolysin, is thermolabile and is hematoxic. Tetanus toxin is very labile, and when in solution soon becomes attenuated. For these experiments it is necessary to use either fresh toxin or that which has been recently precipitated and dried. 1. Secure some dried tetanus toxin and dissolve in sterile salt solution. The toxin may be secured from an antitoxin laboratory and preserved indefinitely in the refrigerator. Since the strength varies with different products, the lethal dose for a 300-gram guinea-pig should be ascertained from the laboratory furnishing the toxin. sterile mortars. 3. Add a lethal dose of fresh tetanus toxin and 5 c.c. sterile salt solution to each. Mix thoroughly and place in the incubator for an hour. Remove and carefully transfer to sterile centrifuge tubes. Centrifuge thoroughly. 896 EXPERIMENTAL INFECTION AND IMMUNITY 3. Into a series of six test-tubes place 1 c.c. of the corpuscle emulsion and increasing doses of toxin: 0.1 c.c., 0.2 c.c., 0.4 c.c., 0.8 c.c., 1 c.c., 2 c.c. Add sufficient normal salt solution to bring the total volume to 3 c.c. 1. Prepare toxin by cultivating the Bacillus botulinus in an alkaline bouillon made in the form of an infusion from ham with the addition of 1 per cent, of glucose, 1 per cent, of peptone, and 1 per cent, of sodium chlorid. Strict anaerobic cultures should be grown for four weeks and filtered through a Berkefeld filter. The toxin may be preserved in brown, sealed vials, and kept on ice, or in a dried form in vacuum. 1. Inoculate a flask of moderately alkaline bouillon with a culture of dysentery bacilli, preferably of the Shiga-Kruse type. Inoculate at 37° C. for two weeks and pass it through a bacterial filter. Inject 2 c.c. of a twenty-four-hour bouillon culture of Staphylococcus aureus in the ear vein of a rabbit. Take the temperature before and every twelve hours after injection. Autopsy the animal seventy-two hours later under aseptic precautions. 3. Into a series of six test-tubes place 1 c.c. of the corpuscle suspension and increasing amounts of Staphylococcus filtrate: .0.1 c.c., 0.2 c.c., 0.4 c.c. 0.8 c.c., 1 c.c., and 2 c.c. Add normal salt solution to bring the total volume to 3 c.c. (e) Examine your blood-agar plates. Are there any peculiar changes around the colonies? To what are these changes due? Does this have any connection with the bloody character of the exudate? 5. Into a series of six small test-tubes place increasing doses of the ricin or abrin solution as follows: 0.1, 0.2, 0.3, 0.4, 0.5, and 0.8 c.c. Add 1 c.c. of rabbit-cell emulsion to each and sufficient normal salt solution to make the total volume in each tube equal to 2 c.c. A seventh tube is the corpuscle control and contains 1 c.c. of the erythrocyte suspension and 1 c.c. of salt solution. 1. Collect about 2 c.c. of normal human blood and place in 5 c.c. of 2 per cent, sodium citrate in 0.85 per cent, sodium chlorid solution. This mixture must not be shaken and the cells should be washed at least four times with normal salt solution, after which they are made up to a 4 per cent, suspension. 5. Place 1 c.c. of each corpuscle suspension into two small test-tubes and add 1 c.c. and 0.5 c.c. each venom dilution. Shake the tubes gently and place in the incubator for an hour and then in the refrigerator overnight. 2. Wash off the growths with 5 c.c. distilled water for each tube. 3. Place the emulsion in a sterile bottle with glass beads and shake for twentyfour hours at room temperature. At the same tune inoculate six more slants of agar and wash off the growths at the end of twenty-four hours with 3 c.c. of normal salt solution for each tube. (c) If any of the animals succumb, autopsy under aseptic precautions. Prepare cultures of the peritoneum and heart's blood on agar slants or in neutral bouillon. Is the typhoid bacillus markedly aggressive? (d) If there is a peritoneal exudate, prepare smears and stain with carbolfuchsin (1 :10). What type of cell predominates? Are any of the bacilli engulfed in the cells? (c) If the animals succumb, autopsy aseptieally. Make cultures of the peritoneum and heart's blood on agar slants or in bouillon. Prepare smears of the exudate and stain with 1 : 10 carbolfuchsin. Do any of the animals show a typhoid bacteremia? Does the filtrate appear to prevent phagocytosis? meter or two of water is added to each bottle to remove the balance of the growth. 4. Centrifuge at high speed until the bacilli are thoroughly settled. Decant off the supernatant fluid and add 50 per cent, alcohol; mix and centrifuge. Decant and add 95 per cent, alcohol; mix and centrifuge. 5. Remove the sediment of bacteria to a small flask with 50 c.c. of absolute alcohol and set aside at room temperature for a day. Decant off the alcohol and add 50 c.c. of ether. Mix and set aside for another twenty-four hours. Decant off the ether that remains and remove sediment to a porcelain or agate mortar. Place in the incubator for a few hours until thoroughly dry. 6. Grind the dry mass very thoroughly, the operator wearing a mask, until a fine powder is produced. Place the powder of bacterial substance in a wide-mouthed dark-glass bottle and preserve in a dark closet. A portion will be needed later for experiments in anaphylaxis. injecting this culture. 2. Autopsy the animal at the end of forty-eight hours and make cultures on agar slants of the heart's blood, liver, and spleen. Remove the heart, lungs, liver, spleen, and kidneys, and place in 2 per cent, formalin. Prepare smears of the blood and stain with Gram's method. 1. Inject a healthy guinea-pig intraperitoneally with 1 c.c. of a twenty-fourhour or forty-eight-hour glucose bouillon culture of streptococci of low or moderate virulence. A culture of staphylococci may be used instead, although the former is preferable. 2. Inject a large albino rat with the same dose and in the same manner. 3. Observe the animals for twenty-four to forty-eight hours. At autopsy prepare smears and cultures of the heart blood of each. Stain the smears with methyleneblue and according to the method of Gram. tions are given. If possible, take temperature every four hours. Observe both animals for symptoms of infection. If one or both succumb, autopsy aseptically and culture the heart blood in neutral bouillon or bile. 3. Place this dose of toxin in a small test-tube or, better, in the barrel of a precision syringe (Hitchens), and add 1 c.c. antitoxin (500 units). Mix thoroughly and keep at room temperature for an hour. 1. Secure a culture of pneumococcus, and if its lethal dose for white mice is unknown, determine this by injecting a series of mice with decreasing doses of a fortyeight-hour serum bouillon culture. prepared with the culture being used, or at least one that is polyvalent. 3. Inject three mice subcutaneously with 0.1, 0.5, and 1 c.c. of the serum. Then inject them subcutaneously with double the lethal dose of pneumococci. Inject a fourth mouse with culture alone (control). 1. Place a drop of blood in the hollow cell of a ground-out slide such as is used for hanging-drop preparations. Cover with a clean slide, seal with a ring of vaselin, and place in a large Petri dish containing pieces of filter-paper moistened with water (moist chamber). Place in the incubator for fifteen minutes. 3. Fill the cell with fresh serum and add a quantity of culture, preferably a loopful of a twenty-four-hour bouillon culture of non-virulent anthrax bacilli. Apply the cover-glass and vaselin the margins to prevent evaporation. glands. 2. Autopsy the animal at the end of twenty-four hours. Prepare hanging-drop preparations and smears of the peritoneal exudate (stained lightly with methyleneblue). Prepare sections of the inguinal and abdominal lymphatic glands. culture of Staphylococcus aureus. 2. Autopsy the animal eighteen hours -later and prepare smears of the exudate. Fix with methyl alcohol for five minutes, dry, and stain with carbol-thionin, Wright's or Loeffler's methylene-blue, counterstained with eosin. 1. Prick the finger and secure 1 c.c. of blood in a small test-tube. Also 1 c.c. in a centrifuge tube containing 2 c.c. of sodium citrate solution. After coagulation remove the serum from the first tube. minutes. 3. Prepare an emulsion of leukocytes by centrifuging the blood collected in the citrate solution, removing the supernatant fluid, adding normal salt solution, and centrifuging again. Repeat this step once more in order to wash the cells thoroughly and after the last centrifuging remove the supernatant fluid and add sufficient salt solution to make the total volume 1 c.c. and mix thoroughly. rubber teats to the other end. 6. With pipet No. 1 take up a volume of blood-cells; allow a bubble of air to enter and then an equal volume of bacterial emulsion; bubble of air and an equal volume of the fresh unheated serum. Mix well by alternate expulsion and aspiration on a clean slide. Then draw the whole into the stem of the pipet and seal the tip in a flame. No. 3: Equal parts of contents of tube 3 and bacterial emulsion. No. 4: Equal parts of contents of tube 4 and leukocytic mixture. 10. Incubate both pipets for fifteen minutes, prepare smears, and stain with carbol-thionin. 2. To No. 1 add 1 c.c. of normal salt solution and 4 or 5 loopfuls of a twentyfour-hour agar slant culture of staphylococci. Incubate for thirty minutes; centrifuge thoroughly and remove the supernatant fluid (diluted serum) to a separate tube. Call this "treated" serum. 5. Prepare an emulsion of staphylococci, homogeneous and free of clumps. 6. Prepare two opsonic mixtures: No. 1 containing equal parts of blood suspension, bacterial emulsion, and untreated serum; No. 2 containing equal parts of blood, bacterial emulsion, and treated serum. (c) Has phagocytosis occurred in the cross-mixtures of staphylococci with typhoid serum, and typhoid bacilli with staphylococcus serum? If so, how do you explain this apparent lack of specificity? 1. Secure a small quantity of blood from a guinea-pig or rabbit which has been immunized with Staphylococcus pyogenes aureus. Also two specimens from normal animals to serve as control serums. Remove the serums, being careful to keep them marked and separate. The two normal serums may be mixed in a watch-glass or small test-tube (pooled). 1. Prepare two to six agar slant cultures of Staphylococcus aureus and grow for twenty-four hours at 37° C. If a patient with furunculosis is available, make cultures of pus and secure Staphylococcus, of which a vaccine is prepared. 2. Proceed in the preparation of the vaccine as given in the text, placing each dose in separate ampules, and so diluting that each dose is of one cubic centimeter and contains 1000 million of cocci. Count by the method of Wright and by the counting chamber method. to one immunity unit. 3. With this antitoxin determine the L+ dose of the toxin prepared according to the technic given, using six guinea-pigs and the following doses of toxin: 0.1 c.c., 0.12 c.c., 0.15 c.c., 0.18 c.c., 0.2 c.c., 0.25 c.c. 4. Secure a sample of diphtheria antitoxin in the open market containing about 4 c.c. serum and 2000 units of antitoxin. If the titration given on the label is still correct, one would expect about 500 units of antitoxin per cubic centimeter of serum. Carefully remove 1 c.c. of serum and dilute with 19 c.c. salt solution (1:20). From this stock dilution prepare the following dilutions (taken from Bulletin No. 21, Hygienic Laboratory, M. J. Rosenau): 5. Mix 1 c.c. of these various dilutions with the L+dose of toxin; stand aside for an hour and inject subcutaneously in median abdominal line of 250- to 300-gram guinea-pig as per the technic already given. 6. Carefully observe all animals for a period of four days at least. Autopsy those that succumb, paying particular attention to the condition of the abdominal wall and suprarenal glands. If the serum should contain less than 300 units of antitoxin per cubic centimeter of serum, the test should be repeated with lower dilutions. 7. Inject 1 c.c. of the serum subcutaneously into a white mouse to test for excess of preservative. It requires 1 c.c. of a 0.5 per cent, solution of tricresol or 0.5 c.c. of a 0.5 per cent, phenol solution to kill a medium-sized mouse. If the mouse shows trembling, it would indicate that the serum contains nearly this percentage of tricresol (Bulletin No. 21, Hygienic Laboratory). 2. Place double this dose of toxin in a series of six small test-tubes and add increasing doses of fresh tetanus antitoxin: 0.001 c.c., 0.005 c.c., 0.01 c.c., 0.05 c.c., 0.1 c.c., 0.2 c.c. Add salt solution to bring the total volume to 1 c.c. ; incubate at 37° C. for an hour. Add 1 c.c. of 1 per cent, suspension of rabbit corpuscles to each tube. Prepare two controls, one with the dose of toxin and corpuscles but to which no serum is added, the second with 0.2 c.c. serum and dose of corpuscles. Shake tubes and incubate for two hours. Make a preliminary reading and again after tubes have settled twenty-four hours in the refrigerator. 1. Prepare a staphylolysin by growing a culture of Staphylococcus aureus in bouillon for two or three weeks. Pass through a Berkefeld filter and preserve the filtrate with 0.5 phenol. Determine the lytic dose for 1 c.c. of a 1 per cent, suspension of rabbit corpuscles. 5. Into a series of six small test-tubes place the lytic dose of staphylolysin and increasing amounts of rabbit immune serum as follows: 0.001, 0.005, 0.01, 0.05, 0.1, 0.2 c.c. Arrange a similar series, using normal horse serum and normal rabbit serum. Prepare a control containing the lytic dose of toxin. Add 1 c.c. of a 1 per cent, suspension of rabbit cells to each tube and sufficient normal salt solution to make the total volume equal 2 c.c. Shake each tube gently and incubate at 37° C. for two hours. 1. Collect 0.5 c.c. of blood in each of two small test-tubes by puncture of a finger; set aside until coagulation has occurred. Add several changes of warm distilled water until the red corpuscles are hemolyzed and colorless clots of leukocytes, fibrin platelets, and detritus are secured. 1. Prepare a solution of trypsin by thoroughly shaking 0.1 gm. of Kahlbaum's trypsin with 5 c.c. glycerin and 5 c.c. distilled water. Incubate at 55° C. for half an hour, shake thoroughly, filter, and preserve in the refrigerator. 4. In a watch-glass or hanging-drop slide mix one drop of serum with an equal sized drop of trypsin solution. Mix well and transfer five loopfuls to an area on a Petri dish of medium. With a blue-wax pencil draw a circle on the cover of the plate to include the site of planting and mark No. 1. 5. Prepare serial dilutions with one drop of serum with two, three, four, five, six, seven, eight, nine, and ten drops of trypsin solution. Mix well and plant five loopfuls of each dilution on the medium in five dishes. Two plantings may be made in each plate and with care they will not become confluent. Mark each plate. FERMENTS 915 dimples appear on the surface of the Loeffler medium. The greater the amount of trypsin required to cause digestion, the higher the titer of antitrypsin in the blood. By conducting a control series with the two normal pooled serums one may determine whether in a given case the antitryptic power of the blood is normal, increased, or decreased. The technic of this test is very exact. The glassware should be sterile and all manipulations carried out carefully and exactly as laid down by Abderhalden. Consult the text for the technic (Chapter 2. Those shells which prove impermeable to albumin are now tested with a 1 per cent, solution of silk peptone (Hochst), using ninhydrin as the indicator. The shells impermeable to albumin and permeable to peptone are suitable for the main test. 3. Secure a fresh human placenta; wash thoroughly to remove blood; cut into pieces about the size of a dime; wash and rewash until perfectly white; search carefully for tiny blood-clots; boil repeatedly until the water reacts negatively to ninhydrin. Consult the text-book for the exact technic. Abderhalden lays a great deal of stress upon the proper preparation of the substratum. 4. Secure blood from a patient in advanced pregnancy; also a specimen from a male. After a few hours, separate the serums and centrifuge thoroughly until free of cells. The serums should not be over twelve hours old. from the clot. 2. Prepare two dilutions with hanging-drop slides, 1 : 50 and 1 : 100, and a culture control. Use a twenty-four-hour bouillon culture of Bacillus typhosus — one free of clumps and in which the bacilli are long and motile. a normal negative serum. 4. Dilution and slides are prepared according to the technic given in the textbook. A second set of tests in dilutions of 1 : 40 and 1 : 80 may be prepared with the aid of the white corpuscle pipet. 5. Place slides away from direct sunlight and examine at the end of an hour. Examinations are readily made with the y§ objective, the light being well cut off. Examine the culture control first, then the higher and lower dilutions. 1. Prepare smears of blood of a typhoid convalescent patient on clean glass slides or collect a few drops on partially glazed paper, as prescription blanks. Allow blood to dry and do not apply heat. 2. Using a good twenty-four-hour-old culture of Bacillus typhosus, prepare an agglutination test after the technic given hi the text-book. Be particularly careful not to transfer paper fiber to the slide — apply the salt solution and dissolve the blood by gently rubbing with a small platinum loop (2 mm.). Mix the blood in the loopful of culture with the slide held or placed over a white surface so that the proper delicate orange tint is secured. 1 c.c., ranging from 1: 10 up to 1:640. 3. Add to each 1 c c. of the bacillary emulsion of a good twenty-four- to fortyeight-hour bouillon culture of Bacillus typhosus or an emulsion prepared by washing twenty-four-hour growths from agar slant cultures with normal salt solution, according to the technic given in the text. This doubles the dilutions, which now range from 1 : 20 up to 1 : 1280. Prepare the culture control. 4. Shake gently and incubate for two hours at 37° C. and then record results after tubes have been standing at room temperature for six hours. Reexamine tubes with the agglutinoscope and note the higher delicacy of such readings. 5. If a typhoid immune serum of unknown titer is used and agglutination is complete in the highest dilution, the test must be repeated with still higher dilutions in order to determine the agglutinin titer of the serum. (d) Are the agglutinated bacilli dead? To determine this, pipet off the supernatant fluids of several tubes into a germicidal solution; then add an excess of sterile normal salt solution to the sediment of agglutinated bacilli, stir up the sediment, and transfer with a sterile pipet to a sterile centrifuge tube; centrifuge thoroughly; remove the supernatant fluid with a sterile pipet and plant several loopf uls of bacteria on slants of agar and in neutral bouillon. Why is it advisable to wash the sediment? (e) What advantages has the macroscopic over the microscopic method? 2. Add one loopf ul of a twenty-four-hour culture of Bacillus typhosus to each tube, being careful to emulsify thoroughly on the side of the test-tube according to the technic given. This does not materially alter the degree of dilution. Prepare the culture control as usual. 1. Inoculate a flask containing 200 c.c. of neutral broth with Bacillus typhosus and incubate for forty-eight hours. At the end of this time a good rich growth is usually secured. Shake gently to stir and break up any clumps of bacilli and heat at 60° C. for one hour on a water-bath, gently shaking the flask once or twice during this time. Add 5 c.c. formalin; shake, and place in the refrigerator for three days; stopper the flask with a rubber stopper, and before using shake well in order thoroughly to mix the dead bacilli which drop to the bottom of the flask. to 1 : 640 of a typhoid immune serum. 2. To the first series add 1 c.c. of a thirty-six-hour bouillon culture of Bacillus typhosus; to the second series, Bacillus paratyphosus "B"; to the third, Bacillus paratyphosus "A"; to the fourth, Bacillus enteritidis (Gartner); to the fifth, Bacillus coli. The dilutions are thus doubled. Prepare culture controls of all five cultures, and be careful that tubes are properly labeled. 1. This very important phase of agglutination may have been noted in the previous experiments, especially if old immune serums were used, when there is a possibility that agglutinin has degenerated in agglutinoids. Agglutinoids having a stronger affinity than agglutinin for the agglutinogen, and having lost the agglutinophore group, produce little or no agglutination and prevent the action of agglutinin until diluted out of action in the higher serum dilutions. In this way agglutination may be poor or absent in low and present in higher dilutions, an important practical fact to be remembered. heated serum. 4. Repeat the tests with old and heated immune serums in dilutions of 1:40, 1:80, 1:160, 1:320, using the macroscopic and microscopic technic, as this phenomenon of pro-agglutination is not infrequently found in the routine Widal reaction in typhoid fever. 1. Immunize a rabbit with three intravenous injections of a heated emulsion of Bacillus typhosus and three of Bacillus paratyphosus "B" or Bacillus coli, according to the technic given under Active Immunization and Methods of Animal Inoculation. 1. Secure 0.1 c.c. of antihuman hemolysin prepared by giving a rabbit a series of injections of washed human erythrocytes. Inactivate the serum by heating to 55° C. for half an hour. Dilute 1: 100 by adding 9.9 c.c. salt solution. 3. Into a series of six small test-tubes place 0.1 c.c., 0.2 c.c., 0.4 c.c., 0.6 c.c., 0.8 c.c., 1 c.c. of the diluted immune serum; add 1 c.c. of suspension of blood-cells and 1 c.c. of salt solution to each tube. As a control, place 1 c.c. of corpuscle suspension and 1 c.c. of normal salt solution into a seventh tube. with normal horse serum. 2. Secure 1 c.c. of normal horse serum and place 2 c.c. of the following dilutions made with normal salt solution into a series of six narrow test-tubes : 1 : 100, 1 : 500, 1:1000, 1:2000, 1:5000, and 1:10,000. Tube 1: 2 c.c. of normal horse serum (1:100)4-0.1 c.c. antihorse serum. Tube 2: 2 c.c. of normal horse serum (1: 100) +0.1 c.c. antihuman serum. Tube 3: 2 c.c. of normal human serum (1:100) +0.1 c.c. antihuman serum. Tube 4: 2 c.c. of normal human serum (1:100) +0.1 c.c. antihorse serum. Tube 5: 2 c.c. of normal guinea-pig serum (1:100) +0.1 c.c. antihorse serum. Tube 6: 2 c.c. of normal guinea-pig serum (1: 100) +0.1 c.c. antihuman serum. Tube 7: 2 c.c. of normal salt solution+0.1 c.c. antihorse serum (control). Tube 8: 2 c.c. of normal salt solution+0.1 c.c. antihuman serum (control). 1. Secure from the instructor two pieces of muslin or gauze containing respectively a stain of human and horse blood. These are to be numbered and the source of each stain known only to the instructor. Secure 1 c.c. each of normal human and horse serum and dilute 1 : 1000. 1. Inoculate two flasks each containing 50 c.c. of sterile neutral bouillon with cultures of Bacillus typhosus and Bacillus coli and cultivate at 37° C. for three weeks. Filter cultures through a sterile Berkefeld filter until clear. 2. Into a series of four small test-tubes place 2 c.c. of the following dilutions of the typhoid filtrate (precipitinogen) undiluted: 1:2, 1:4, and 1:10. Prepare a second series of tubes with similar amounts of the same dilutions of Bacillus coli filtrate. serum with high agglutinin titer will be satisfactory. 4. Place 2 c.c. of the undiluted typhoid and coli filtrates in separate tubes as controls. Prepare an additional control by placing 0.1 c.c. of the typhoid immune serum in 2 c.c. normal salt solution. 1. Arrange a series of twenty-three small sterile test-tubes in a rack; to each of the first twenty-one tubes add 3 c.c. of various dilutions of salt solutions ranging from 0.6 per cent, to 0.2 per cent, in steps of 0.02 per cent. Large amounts of these solutions should be at hand, preserved in bottles fitted with tight cork stoppers to prevent evaporation, or prepared at the time according to the technic given in the text (page 402). To tube No. 22 add 3 c.c. distilled water and to No. 23 the same amount of normal salt solution (0.85 per cent.). have been standing hi the refrigerator overnight. 4. Note the appearance of hemolyzed blood. Prepare a color scale by placing 1 c.c. blood-corpuscles in 30 c.c. distilled water, which represents a standard of 100 per cent, hemolysis. From this solution prepare dilutions with distilled water to represent 80, 60, 40 and 20 per cent, hemolysis. For example, 4 c.c. of the stock solution plus 1 c.c. distilled water equals 5 c.c. of an 80 per cent, solution; 3 c.c. of the stock plus 2 c.c. water equals a 60 per cent, solution; 2 c.c. of stock plus 3 c.c. of water equals a 40 per cent, solution, and so on. Carefully compare the volume of non-hemolyzed cells in the bottom of some of the test-tubes with the amount of color in the supernatant fluid. A Duboscq colorimeter may be used for making comparisons with the controls. EXPERIMENT 70. — THE HEMOLYTIC INFLUENCE OF ACIDS AND ALKALIS The object of this experiment is to demonstrate the hemolytic activity of acids and alkalies as bearing upon the question of clean glassware in hemolytic work, and particularly complement-fixation tests. 1. Into a series of six test-tubes place increasing amounts of a solution of hydrochloric acid prepared by diluting 1 c.c. of the normal solution with 99 c.c. of normal salt solution: 0.2, 0.4, 0.6, 0.8, 1.0, and 2.0 c.c. respectively. 2. Into a second series of six test-tubes place increasing amounts of a solution of sodium hydroxid prepared by diluting 1 c.c. of the normal solution with 99 c.c. of normal salt solution: 0.2, 0.4, 0.6, 0.8, 1.0, and 2.0 c.c. respectively. 1. Secure 2 c.c. of blood from the ear of a rabbit which has received at least two intravenous injections of sheep cells. Separate the serum and divide into two portions. Inactivate one portion (A) by heating in a water-bath for half an hour at 56° C. 2. Place 0.1 c.c. and 0.2 c.c. of the fresh unheated serum of portion (B) in two test-tubes. Likewise the same amounts of the heated serum (A) in two more tubes. Add 1 c.c. of a 1 per cent, suspensior of washed sheep cells to each tube and sufficient salt solution to bring the total volume to 3 c.c. As a control, place 1 c.c. of corpuscle suspension and 3 c.c. salt solution in a tube. Shake gently, and incubate for an hour. (d) Examine sections of the spleen, liver, and kidneys. Are there any evidences of phagocytosis of blood-cells, focal necrosis, and nephritis? Explain the probable mechanism of the production of these changes. 1. Secure 1 or 2 c.c. of blood from the ear of a rabbit which has been immunized with injections of sheep cells. Separate the serum and inactivate by heating to 56° C. for half an hour. Dilute 1: 100 by adding 0.1 c.c. serum to 9.9 c.c. normal salt solution. 2. Prepare 40 c.c. of a 5 per cent, dilution 01 fresh guinea-pig serum to be used for complement. Prepare 40 c.c. of a 2^2 per cent, suspension of washed sheep cells by adding 1 c.c. of corpuscles to 39 c.c. of normal salt solution. 3. Proceed with the titration as given in the text on page 397. If the smallest dose, viz., 0.1 c.c. of the 1 : 100 dilution, completely hemolyzes the corpuscles, it will be necessary to retitrate with a dilution of 1 : 1000. 2. To a series of four test-tubes add an amount of immune serum equaling one, two, three, and five amboceptor units respectively. To each tube add 0.5 c.c. of the 1 : 20 dilution of complement serum. This amount is just half the dose of complement used in titrating the amboceptor. Add 1 c.c. of a 2^ per cent, suspension of sheep cells to each tube and sufficient salt solution. 1. Prepare a 2^ per cent, suspension of washed sheep corpuscles. Bleed a healthy guinea-pig under ether anesthesia, separate the serum, and dilute 1 : 20 with normal salt solution (complement). Secure antisheep hemolytic serum (inactivated) whose hemolytic titer is known (consult instructor) . 5. Remove a tube from the water-bath after five minutes, ten minutes, fifteen minutes, thirty minutes, forty-five minutes, and one hour. After allowing them to cool, add 1 c.c. corpuscle suspension and 1 c.c. complement serum (1 : 20). 4. Into two centrifuge tubes place four units of amboceptor and 1 c.c. of corpuscle suspension. Mix and place one tube in a glass of cracked ice, leaving the other at room temperature. After one hour centrifuge both. Pipet the supernatant fluids into two separate test-tubes. CEPTORS 1. In a centrifuge tube place two hemolytic doses of antisheep hemolysin and 2 c.c. of fresh guinea-pig complement diluted 1 : 20. Place in a glass of cracked ice until the mixture is thoroughly chilled. Then add 2 c.c. of a 1\ per cent, suspension of sheep cells (also chilled). Mix and keep at a low temperature for an hour, centrifuge thoroughly, and pipet the supernatant fluid to a separate test-tube. 2. In a second centrifuge tube place 2 c.c. of diluted complement and 2 c.c. corpuscle suspension. Keep at room temperature for one hour, centrifuge, and pipet the supernatant fluid into a test-tube. 3. Proceed as follows: To 2 c.c. of the supernatant fluid from the first centrifuge tube add 1 c.c. corpuscle suspension; to the remaining 2 c.c. add 1 c.c. corpuscle suspension and two units of amboceptor; to the sedimented corpuscles add 2 c.c. of diluted complement serum. 2. Remove 0.5 c.c. of serum from each to five separate centrifuge tubes and add 4.5 c.c. of 2}^ per cent, suspension of sheep cells to each. Shake gently and after half an hour at room temperature centrifuge thoroughly and pipet the supernatant dilute serum to separate tubes. Do not discard the corpuscles in the centrifuge tubes. Note. — The quantity of natural amboceptor in any of these serums may be determined by the method of titration given in the text. In choosing five serums at random it may be possible that some will not show an appreciable amount of natural antisheep amboceptor. 1. After giving a rabbit three intravenous injections of 5 c.c. of a 10 per cent, suspension of washed sheep cells at intervals of three days, remove three cubic centimeters of blood from an ear and separate the serum. Dilute the serum 1 : 10 with salt solution. 2. Into four test-tubes place 1 c.c. of a 2^ per cent, suspension of sheep corpuscles and increasing amounts of the above dilution of rabbit serum (must be fresh — not over twelve hours old) as follows: 0.4, 0.8, 1, and 2 c.c.; add sufficient salt solution. Shake and incubate for one hour. Add 1 c.c. of a 2^ per cent, suspension of sheep corpuscles, two hemolytic units of antisheep amboceptor, and sufficient normal salt solution to each tube. Shake gently and incubate at 37° C. for one hour. 4. Into a series of six test-tubes place 1 c.c. of fresh guinea-pig complement serum diluted 1 : 20. Place these in a water-bath at 56° C. At intervals of ten, twenty, thirty, forty, fifty, and sixty minutes remove a tube, add 1 c.c. corpuscle suspension, two units of amboceptor, and sufficient salt solution. Shake gently each tube and incubate for one hour at 37° C. sheep cells. 2. To a series of 10 test-tubes add increasing doses of diluted complement serum: 0.1, 0.2, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, and 1.5 c.c.; add 1^ units of hemolytic amboceptor (determined by previous titration) ; 1 c.c. of corpuscle suspension and sufficient salt solution to bring the total volume in each tube to 3 c.c. This experiment is introduced here to show the Bordet-Gengou phenomenon of complement fixation. The exact technic of complementfixation reactions as conducted for the diagnosis of syphilis and other infections will be given in subsequent exercises. (f) What is meant by specific complement fixation? Explain the phenomenon. Which tube of this series shows specific complement fixation and why? Is there any evidence of non-specific fixation in any of the tubes? If so, what bearing would this have on the results of this test? While the above extracts are in the course of preparation, stock extracts may be used for titration. After the student has finished the above three extracts, they are titrated in a similar manner. 1. Dilute 1 c.c. of an alcoholic extract of syphilitic liver in a test-tube 1:10 by slowly adding 9 c.c. of normal saline solution. Dilute a cholesterinized extract (1 : 20) by slowly adding 9.5 c.c. salt solution to 0.5 c.c. of extract. (d) In a complement-fixation test what would be the result if the antigen were used in the anticomplementary dose? What would be the result if the antigen were used in less than the antigenic dose? (f ) In conducting a diagnostic reaction, should the antigen be used in exactly one antigenic dose or double or treble this amount? Why and under what conditions would this be a safe procedure? 1. Secure 1 c.c. of five different specimens of human serums which have been standing in the laboratory for one, two, four, six, and ten days respectively. The last specimen should be intentionally infected with a culture of staphy loco ecus. 5. To each tube add 1 c.c. of complement 1:20 and sufficient salt solution to bring the total volume to 3 c.c. Shake gently and incubate for half an hour. Add 1^ units of amboceptor and 1 c.c. corpuscle suspension to each tube and incubate for one hour. (e) How are thermolabile anticomplementary bodies removed or their influence overcome? When a serum is three or more days old, what is the chief object of heating it before it is used in a complementfixation test? (g) Is it possible to remove the thermostabile anticomplementary action of a serum? Could such a serum be used in a complement-fixation reaction? How is this condition of the serum detected? 1. Secure four specimens of blood: one from a known syphilitic person; the second from a known normal person, the third and fourth specimens for diagnosis. Also a specimen of cerebrospinal fluid. using an antigen of alcoholic extract of syphilitic liver. (a) Record your results. In case the hemolytic system control was not completely hemolyzed, what may be the reasons and what influence would this result have on interpreting the reactions? 1. Conduct a Wassermann reaction with each of five specimens of serum after the second method, using an alcoholic extract of syphilitic liver, an extract of acetoneinsoluble lipoids, and an alcoholic extract of heart reenforced with cholesterin. One of these serums should be from a syphilitic person (positive control) and one from a normal person (negative control) . Conduct a Wassermann reaction with each of four specimens of serum after the third method, using an extract of acetone-insoluble lipoids. One of these serums should be a positive control and one a normal or negative control. 2. To a series of six small test-tubes add increasing amounts of diluted amboceptor as follows: 0.1, 0.2, 0.4, 0.6, 0.8, and 1 c.c., add 0.1 c.c. of 40 per cent, complement, 1 c.c. of 1 per cent, human corpuscle suspension, and sufficient saline solution to bring the total volume to 2 c.c. 1. Secure six specimens of serum from a genito-urinary clinic, particularly of men suffering with chronic gonococcus infections. Also a known positive and a known normal serum for controls. 1. Secure 1 c.c. of serum from a rabbit which has been immunized with typhoid bacilli. By working with cholera and a highly potent serum better results are secured, but as there is probably more danger connected with the handling of cholera cultures, typhoid may be substituted with fairly good results. Inactivate by heating to 56° C. for half an hour. typhosus. 3. Prepare a 1 : 100 dilution of the immune serum and place 3 c.c. in a small testtube. Add three loopfuls of culture and emulsify thoroughly. Inject a guinea-pig intraperitoneally with 2 c.c. of the emulsion. 4. At intervals of ten, twenty, forty, and sixty minutes withdraw small amounts of exudate and study bacteriolysis; prepare hanging-drop preparations which may be compared with a similar control on the culture; prepare smears of the culture and peritoneal exudate and stain with carbol-thionin or carbolfuchsin. 1. Secure a small quantity of the patient's serum by collecting blood aseptically in a Wright capsule. About 1 c.c. of serum will be sufficient. Secure a control serum, preferably a "pooled serum," in the same manner. Prepare dilutions of the patient's serum in the following manner: Place a series of six small test-tubes (sterile) in a rack; add 1 c.c. sterile broth to each tube; into the first tube place 1 c.c. of the fresh serum from the patient (1:2 dilution) ; mix well and transfer 1 c.c. to the second tube; mix and transfer 1 c.c. to the third, and so on to the last tube, when 1 c.c. is discarded. 3. Take a simple capillary pipet with a long stem, plugged with cotton and sterilized, and make a mark about 3 cm. from the end. Draw up the highest dilution of serum to the pencil mark, then a bubble of air, and finally an equal volume of culture. Thoroughly mix by carefully aspirating and driving out the contents on a hollow ground slide or in a small tubule. Aspirate the mixture into the middle portion of the stem and seal the pipet in a flame. Label with the final dilution (1 : 128). 4. Proceed in the same manner with the remaining five dilutions of the patient's serum, which then, mixed with an equal quantity of culture, equals 1 : 64, 1 : 32, 1 : 16, 1 : 8, and 1 : 4. Place these pipets in a large test-tube and label with the patient's name and time when placed in the incubator. 8. Prepare hanging-drop preparations of each pipet by breaking off the tip and placing a drop of the contents (after mixing) on a cover slide and suspending in the usual manner. First examine the culture control and then each of the various dilutions, noting in each case the dilution in which there is the first bacteriolytic effect, and the dilution in which there is a complete effect; arrive at the bacteriolytic index by comparing the patient's and the control blood just as the opsonic index is stated. 4. After three days autopsy and examine the kidneys and liver histologically. 5. Heat the immune serum to 56° C. for thirty minutes and place increasing amounts in a series of test-tubes as follows: 0.01, 0.05, 0.08, 0.1, and 0.2 c.c.; add 1 c.c. of fresh guinea-pig complement serum 1 : 20, and 1 c.c. of 2^ per cent, suspension of washed dog erythrocytes. Incubate for two hours. For experiments in anaphylaxis sensitize a series of animals as follows: (a) Give seven young guinea-pigs an intraperitoneal injection of 0.01 c.c. horse serum (1 c.c. of a 1 : 100 dilution). 1. Place 15 grams of coli bacterial substance prepared as described on page 128 in a distilling flask and add 250 c.c. of a 2 per cent, caustic soda in absolute ethyl alcohol. Place on a water-bath attached to a reflux condenser and collect the distillate. Wassermann reaction after, 491 Angina, Vincent's, salvarsan in, 881 Animal blood. See Blood, animal. cold-blooded, anaphylaxis in, 577 conjunct! val tuberculin test in, 641 cutaneous tuberculin test in, 642 experiments, 891 Antigenic dose of syphilitic serum, 442 titration in Wassermann reaction, 455 values of various extracts in serum Arthus phenomenon of anaphylaxis, 569 Artificial aggressins, 104, 126 Ascoli and Izar's miostagmin test, 563 action, 482 B. E. tuberculin, preparation of, 718 Behring-Ehrlich antitoxin unit, 240 Behring's method of immunization cleaning and care of, 78 Besredka's theory of anaphylaxis, 591 B. F. tuberculin, preparation of, 718 Biologic blood test for detection of bloodstains, 326 complement-fixation test in, 532 contraindications to vaccines in, 668 eosin-selenium compound in, 888 epiphanin reaction in, 563 nature of, 756 of eye, dosage of antitoxin in, 763 of vulva, dosage of antitoxin in, 763 of wounds, dosage of antitoxin in, treatment, 732 Glanders, agglutination reaction in, 293 complement-fixation test in, 511 mallein reaction for, 647. See also test in, 524 Hydrocele, autoserum treatment, 842 Hydrocephalus in meningococcus meningitis, effect of serum treatment on, relation of anaphylaxis to, 603 treatment with specific serum of convalescents and with normal serum, 825 Jennerian vaccination, 173 Jobling and Flexner's method of preparing antimeningococcus serum, 791 Joints, tuberculosis of, tuberculin test Keidel tube for collecting blood, 35, 36 Keratosis follicularis, salvarsan in, 881 Koch's subcutaneous tuberculin test, tination test, 305 and Strong's plague vaccine, 695 Kolle's cholera vaccine, preparation, 697 method of counting bacterial vaccines, test, 628, 636 Maragliano's tuberculosis serum, 824 Marasmus, autoserum treatment, 843 Marcus modification of M tiller and Jochmann's method of testing blood-serum, experimental work, 914 serum, 823 Marmorek's tuberculosis serum, 824 McDonagh gel test for syphilis, 323 Measles, effect of, on tuberculin reaction, test, 480 Nolf's theory of anaphylaxis, 593 Nucleoproteins, production of, 74 Nuttall's method of obtaining large amount of blood from rabbit, 43 preparation of, 716 Otitis media, vaccine therapy, 711 Overproduction theory of Weigert, 150 Overwork as predisposing to disease, 101 Oxford University macroscopic agglutination test, 305 in diagnosis of, 632 Pertussis, agglutination reaction in, 293 complement-fixation reaction in, 521 prophylactic immunization in, 700 vaccine therapy, 710 of staphylococcus infections, 819 of streptococcus infections, 813 of tetanus, 772. See also Tetanus Streptolysin, 119 Streptotoxin, experimental work, 898 Strong and Kolle's plague vaccine, 695 Strong's cholera vaccine, preparation, 698 Subcutaneous injection of animals, 54 with fluid inoculum, 54 Browning and Mackenzie's modification of Wassermann reaction, 484 cerebrospinal, Lange's colloidal gold Tritotoxin, 116 Tropical ulcer, salvarsan in, 881 Trypanosomiasis, salvarsan in, 881 Tubercle bacilli, living, in treatment of of, 632 pleurisy, autoserum treatment, 841 tuberculin test in diagnosis of, 632 Typhoid fever, agglutination test in, 290, Clinical Manual of Mental Diseases. By FRANCIS X. DERCUM, PH. D., M. D., Professor of Nervous and Mental Diseases at Jefferson Medical College, Philadelphia. Octavo ot 479 pages. Cloth, $3.50 net. This is a book really useful to the family physician — a book that tells you definitely how to diagnose, how to treat — either at home or in an institution — all classes of mental diseases. First, Dr. Dercum takes up the various primary forms of mental disease, giving emphasis to those you meet in your daily practice as genera.l practitioner — delirium, confusion, stupor. Then melancholia, mania, the insanities of early life, paranoia, the neurasthenic-neuropathic disorders, and the dementias follow. The mental disturbances of the infections (syphilis, tuberculosis, malaria, pellagra, rheumatic fever, etc.), the various forms of intoxicational insanities, those due to metabolic disorders, visceral disease, diseases of the nervous system are all given you — and from your viewpoint. An important section is that devoted to the insanities of pregnancy. An entire part is devoted to the psychologic interpretations of symptoms as evolved by Freud and his disciples. You get a full discussion of the role of dreams. Our books are revised frequently, so that the editions you find here may not be the latest. Write us about any books which interest you Nervous and Mental Diseases Nervous and Mental Diseases. By ARCHIBALD CHURCH, M. D., Professor of Nervous and Mental Diseases and Medical Jurisprudence, Northwestern University Medical School, Chicago; and FREDERICK PETERSON, M. D., formerly Professor of Psychiatry at the College of Physicians and Surgeons, N. Y. Handsome octavo, 944 pages; 350 illustrations. Cloth, $5.00 net. October, 1914 EIGHTH EDITION For this new (8th) edition this standard work has undergone a thorough revision. Vertigo and its labyrinthine relations, as developed by Barany, has received careful consideration ; much new matter has been added to the section on Infantile Paralysis; syphilis of the nervous system has been brought into accord with recent epoch-making discoveries. Throughout, references to the new investigations of the spinal fluid, and the relation of spinal fluid changes to the various organic diseases of the brain and cord have been introduced. The bearing of internal secretion upon nervous disorders has been brought right down to date. Tetany has been given its place among nervous diseases associated with glandular disorder. Altogether over 300 interpolations and alterations have been made. It is more than ever the. standard. American Journal of the Medical Sciences " This edition has been revised, new illustrations added, and some new matter, and really is two books. . . . The descriptions of disease are clear, directions as to treatment definite, and disputed matters and theories are omitted. Altogether it is a most useful text-book." Serology of Nervous and Mental Diseases. By D. M. KAPLAN, M. D., Director of Clinical and Research Laboratories, Neurological Institute, New York City. Octavo of 346 pages, illustrated. Cloth, This is an entirely new work, giving you the indications, contra-indications, preparation of patients, technic, after-phenomena, after-care, and disposal of the fluids obtained by lumbar puncture. You get a full discussion of the serology of all nervous. and mental diseases of non-luetic etiology (including disorders of internal secretion), and of every type of luetic nervous and mental disease, giving the Wassermann reaction in detail, the use of salvarsan and neosaivarsan, etc. A KEY TO NEUROLOGY Professor Herrick's new work will aid the student to organize his knowledge and appreciate the significance of the nervous system as a mechanism right at the beginning of his study. It is sufficiently elementary to be used by students of elementary psychology in colleges and normal schools, by students of general zoology and comparative anatomy in college classes, and by medical students as a guide and key to the interpretation of the larger works on neurology. A Laboratory Outline of Neurology. By C. JUDSON HERRICK, PH. D., Professor of Neurology, University of Chicago ; and ELIZABETH C. CROSBY, PH. D., Principal of the High School, Petersburg, Mich. Psychanalysis : Its Theories and Practical Application. By A. A. BRILL, PH. B., M. D., Clinical Assistant in Neurology at Columbia University Medical School. Octavo of 392 pages. Cloth, $3.25 net. To the general practitioner, who first sees these "borderline" cases (the neuroses and the psychoses), as well as to those specially interested in neurologic work, Dr. Brill's work will prove most valuable. Dr. Brill has had wide clinical experience, both in America and in Europe. The results of this experience you get in this book. Here you get the practical application of all Freud's theories — and from the pen of a man thoroughly competent to write. Diagnostic Symptoms of Nervous Diseases. By EDWARD L. HUNT, M. D., formerly Instructor in Neurology and Assistant Chief of Clinic, College of Physicians and Surgeons, New York. I2mo of 292 The American Illustrated Medical Dictionary. A new and complete dictionary of the terms used in Medicine, Surgery, Dentistry, Pharmacy, Chemistry, Veterinary Science, Nursing, and kindred branches; with over 100 new and elaborate tables and many handsome illustrations. By W. A. NEWMAN BORLAND, M. D. Large octavo 1 179 pages, bound in full flexible leather, $5.00 net ; with thumb The American Illustrated Medical Dictionary defines hundreds of terms not defined in any other dictionary — bar none. It gives the capitalization and pronunciation of all words. It makes a feature of the derivation or etymology of the words. Every word has a separate paragraph, thus making it easy to find a word quickly. The tables of arteries, muscles, nerves, veins, etc., are of the greatest help in assembling anatomic facts. Every word is given its definition — a definition that defines in the fewest possible words. The Treatment of Emergencies. By HUBLEY R. OWEN, M. D., Surgeon to the Philadelphia General Hospital. I2mo of 350 pages, with 249 illustrations. Cloth, $2.00 net. Published June, 191? Dr. Owen's book is a complete treatment of emergencies. It gives you not only the actual technic of the procedures, but, what is equally important, the underlying principles of the treatments, and the reason why a particular method is advised. You get treatments of fractures, of contusions, of wounds. Particularly strong is the chapter on gun-shot wounds, which gives the new treatments that the great European War has developed. You get the principles of hemorrhage, together with its constitutional and local treatments. You get chapters on sprains, strains, dislocations, burns, sunburn, chilblain, asphyxiation, convulsions, hysteria, apoplexy, exhaustion, opium poisoning, uremia, electric shock, bandages, and a complete discussion of artificial respiration, including mechanical devices. Practice of Pediatrics. By CHARLES GILMORE KERLEY, M. D., Professor of Diseases of Children, New York PolycKnic Medical School and Hospital. Octavo of 913 pages, illustrated. Cloth, $6.50 net. This work is not a cut-and-dried treatise — but the practice of pediatrics, giving fullest attention to diagnosis and treatment. The chapters on the newborn and its diseases, the feeding and growth of the baby, the care of the mother's breasts, artificial feeding, milk modification and sterilization, diet for older children — from a monograph of 125 pages. Then are discussed in detail every disease of childhood, telling just what measures should be instituted, what drugs given, 60 valuable prescriptions being included. The chapter on vaccine therapy is right down to the minute, including every new method of proved value — with the exact technic. There is an excellent chapter on Gymnastic Therapeutics. Another feature consists of the 163 illustrative cases — case teaching of the most practical sort. Published August, 1916 This is decidedly a book for the woman preparing for childbirth. It has chapters on menstruation, nourishment of mother during pregnancy, nausea, care of breasts, examination of urine, preparations for labor, care of mother and child after delivery, twilight sleep, and dozens of other matters of great interest to the expectant mother. Published November, 1916 This book is a practical guide for the layman, giving him briefly the means to avoid the various diseases described. The chapters on diet, exercise, tea, coffee, and alcohol are of special interest, as is that on the preventionof cancer. There are chapters on the prevention of malaria, colds, constipation, obesity, nervous disorders, tuberculosis, etc. The work is a record of twenty-five years' active practice. Dr. Kerr's work is written absolutely for the general practitioner — to aid him in diagnosing disease in his child patients. He approaches his subject as the child is approached in the sick-room. It is strictly a clinical work — a first aid in the diagnosis of disease in children. Published February, 1907 CLINICAL. LECTURES IN INFANT FEEDING. By LEWIS WEBB HILL, M. D., Alumni Assistant in Pediatrics, Harvard Medical School, and JESSE R. GERSTLEY, M. D., Instructor in Pediatrics, Northwestern University Medical School. I2mo of 377 pages, illustrated. Cloth, In these clinics you are given the full details of the Boston method of infant feeding as developed by Dr. Rotch, and of the Chicago method. You are given the theory, use in both normal and abnormal cases, exact quantities and percentages, and concrete clinical examples. The book is equivalent to a postgraduate course in infant feeding. It brings these two systems right to your door. THE PREPARATION OF INFANTS' FOODS. By ISAAC A. ABT, M.D., Professor of Diseases of Children, Northwestern University Medical School. i2mo of 143 pages. Cloth, $1.25 net. Published July, 1917 This is a practical guide for infant feeding, giving to young mothers, nurses, and caretakers minute directions on the preparation of food for infants and young children. You get weights and measures; the mineral constituents and caloric values of foods. You get such practical material as diet-lists for constipation in older children, an outline of a plan for feeding babies, care of nipples and bottles, etc., and a great host of recipes for beverages of all kinds, milk preparations, soups and broths, puddings and cereal preparations, custards, eggs, vegetables, fruits, meats, sea foods, and breads. The point about this work is this : It tells you and shows you just how to do those little but important things often omitted from other nursing books. "Home Treatments" and "Points to be Remembered" — terse, crisp reminders — stand out as particularly practical. Just the book for those who have the home-care of the sick. THE FOUR EPOCHS OF WOMAN'S LIFE. By ANNA M. GALBRAITH, M.D. With an Introductory Note by JOHN H. MUSSER, M.,D., University of Pennsylvania. i2mo of 296 pages. Cloth, $1.50 net. " We do not as a rule care for medical books written for the instruction of the public ; but we must admit that the advice in Dr. Galbraith's work is, in the main, wise and wholesome." — Birmingham Medical Review. Published March, 1917 The Care of the Baby. By J. P. CROZER GRIFFITH, M. D., Professor of Pediatrics in the University of Pennsylvania. I2mo of 455 pages, illustrated. ' Cloth, $1.50 net. Infant Feeding. By CLIFFORD G. GRULEE, M. D., Assistant Professor of Pediatrics at Rush Medical College. Octavo ot 326 pages, illustrated, including 8 in colors. Cloth, $3.25 net. Dr. Grulee tells you how to feed the infant. He tells you — and shows by clear illustrations — the technic of giving the child the breast. Then artificial feeding is thoughtfully presented, including a number of simple formulas. The colored illustrations showing the actual shapes and appearances of stools are extremely valuable. In revising this work for the fourth edition Dr. Ruhrah has carefully incorporated all the latest knowledge on the subject. All the important facts are given concisely and explicitly, the therapeutics of infancy and childhood being outlined very carefully and clearly. There are also directions for dosage and prescribing, and many useful prescriptions are included. Military Hygiene and Sanitation. By LIEUT.-COL. FRANK R, KEEPER, Professor of Military Hygiene, United States Military Academy, West Point. I2mo of 305 pages, illustrated. Cloth, $1.50 net. This is a concise, though complete text-book on this subject, containing chapters on the care of troops, recruits and recruiting, personal hygiene, physical training, preventable diseases, clothing, equipment, water-supply, foods and their preparation, hygiene and sanitation of posts and barracks, the troopship, hygiene and sanitation of marches, camps, and battlefields, disposal of wastes, tropical and arctic service, venereal diseases, alcohol and other narcotics, and a glossary. The Principles of Hygiene : A Practical Manual for Students, Physicians, and Health Officers. By D. H. BERGEY, A. M., M. D., Assistant Professor of Bacteriology in the University of Pennsylvania. Octavo volume of 543 pages, illustrated. Cloth, $3,50 net. This book is intended to meet the needs of students of medicine in the acquirement of a knowledge of those principles upon which modern hygienic practises are based, and to aid physicians and health officers in familiarizing themselves with the advances made in hygiene and sanitation in recent years. This fifth edition has been very carefully revised, and much new matter added, so as to include the most recent advancements. •' It will be found of value to the practitioner of medicine and the practical sanitarian ; and students of architecture, who need to consider problems of heating, lighting, ventilation, water supply, and sewage disposal, may consult it with profit." A MANUAL OF PERSONAL HYGIENE : Proper Living upon a Physiologic Basis. By Eminent Specialists. Edited by WALTER L. PYLE, A. M., M. D., Assistant Surgeon to Wills Eye Hospital, Philadelphia. Octavo volume of 555 pages, fully illustrated. Cloth, $i.75 net. The book has been thoroughly revised for this new edition, and a new chapter on Food Adulteration by DR. HARVEY W. WILEY added. There are important chapters on Domestic Hygiene and Home Gymnastics, Hydrotherapy, Mechanotherapy, and First Aid Measures. " The work has been excellently done, there is no undue repetition, and the writers have succeeded unusually well in presenting facts of practical significance based on sound knowledge."— Boston Medical and Surgical Journal. Massage. By MAX BOHM, M. D., of Berlin, Germany. Edited, with an Introduction, by CHARLES F. PAINTER, M, D., Professor of Orthopedic Surgery at Tufts College Medical School, Boston. Octavo of 91 pages, with 97 practical illustrations. Published June, 1913 Cloth, $1.75 net. Atlas and Epitome of Diseases Caused by Accidents. By DR. ED. GOLEBIEWSKI, of Berlin. Edited, with additions, by PEARCE BAILEY, M. D., Consulting Neurologist to St. Luke's Hospital, New York. With 71 colored illustrations on 40 plates, 143 text illustrations, and 549 pages of text. Cloth, $4.00 net. In Saunders' Hand- Atlas Series. Published 1901 Atlas of Legal Medicine. By DR. E. VON HOFMANN, of Vienna. Edited by FREDERICK PETERSON, M. D., Professor of Psychiatry in the College of Physicians and Surgeons, New York. With 120 colored figures and 193 half-tone illustrations. Cloth, $3.50 net. Published April, 1898 Atlas and Epitome of the Nervous System and its Diseases. By PROFESSOR DR. CHR. JAKOB, of Erlangen. Edited, with additions, by EDWARD D. FISHER, M. D., University and Bellevue Hospital Medical College. With 83 plates and copious text. Cloth, $3. 50 net. Published IQOI This is a comprehensive digest, supplying the means to a clear understanding of neurology, and robbing that subject of much of its difficulty. You are given, first, a brief description of the practical anatomy and physiology, with those facts and theories that bear on the mechanism of organic nervous diseases. Then pathology is given, the simpler diseases being considered first, gradually preparing the reader to grasp the more difficult ones. The descriptions are clear and brief, differential diagnoses and treatments being brought out very definitely. Only the most recent accepted facts have been considered. For the treatments recommended, no special apparatus is required beyond a galvanic and faradic battery; they demand no special training, and they are easily remembered. AMERICAN POCKET MEDICAL DICTIONARY. Edited by W. A, NEWMAN DORLAND, M. D., Editor "American Illustrated Medical Dictionary." Containing the pronunciation and definition of the principal words used in medicine and kindred sciences, with 75 extensive tables. With 707 pages. Flexible leather, with gold edges, $1.25 net; with patent thumb index, $1.50 net. Published October, 1917 IMMEDIATE CARE OF THE INJURED. By ALBERT S. MORROW, M. D., Clinical Professor of Surgery at the New York Polyclinic. Octavo of 356 pages, with 242 illustrations. Cloth, $2.75 net. Published November, 1917 Dr. Morrow's book on emergency procedures is written in a definite and decisive style, the reader being told just what to do in every emergency. It is a practical book for every day use, and the large number of excellent illustrations can not but make the treatment to be pursued in any case clear and intelligible. Physicians and nurses will find it indispensible. Shaw on Nervous Diseases and Insanity Fifth Edition ESSENTIALS OF NERVOUS DISEASES AND INSANITY: Their Symptoms and Treatment. A Manual for Students and Practitioners. By the late JOHN C. SHAW, M. D., Clinical Professor of Diseases of the Mind and Nervous System, Long Island College Hospital, New York. i2mo of 204 pages, illustrated. Cloth, $1.25 net. In Saunders* Question- Com- pend Series. Published October, 1913 " Clearly and intelligently written ; we have noted few inaccuracies and several suggestive points. Some affections unmentioned in many of the large text-books are noted.' — Boston Medical and Surgical Journal. Hecker, Trumpp, and Abt on Children ATLAS AND EPITOME OF DISEASES OF CHILDREN. By DR. R. HECKER and DR. J. TRUMPP, of Munich. Edited, with additions, by ISAAC A. ABT, M.D., Assistant Professor of Diseases of Children, Rush Medical College, Chicago. With 48 colored plates, 144 text-cuts, and 453 pages of text. Cloth, $5.00 net. Published April, 1007 The many excellent lithographic plates represent cases seen in the authors' clinics, and have been selected with great care, keeping constantly in mind the practical needs of the general practitioner. These beautiful pictures are so true to nature that their study is equivalent to actual clinical observation. The editor, Dr. Isaac A. Abt, has added all new methods of treatment.	427,462	common-pile/pre_1929_books_filtered	practicaltextinf00kolmrich	public_library	public_library_1929_dolma-0007.json.gz:682	https://archive.org/download/practicaltextinf00kolmrich/practicaltextinf00kolmrich_djvu.txt
zNSEZHRgxsydsYNM	6.1: Choosing a Topic	6.1: Choosing a Topic Questions to Consider When it comes to academic research, choosing a topic is often the hardest part of the process! In many instances, college instructors will provide guidelines or a broad topic for the assignment, but it’s your job to choose a narrower topic within those guidelines. Here are some questions to ask yourself before you decide on a topic to research: - Have I been assigned a specific topic or can I choose my own? - Is there a particular current event that interests me or an issue I feel strongly about? Can I select a topic that is closely related to my college major? - Did the instructor specify what types of information sources I need to use? Narrowing Your Topic It is important to select a topic that not only interests you or sparks your curiosity, but also one that is neither too broad or too narrow in scope. For example, if you are interested in climate change and wanted to choose that as a topic for your research paper, you would quickly find yourself overwhelmed with search results and information. You may find millions of search results about all different aspects of climate change, like policy, history, and the environment, and feel lost about where to begin. An important step in the research process is narrowing down your larger topic into a smaller, more researchable topic. What is it about climate change that is most interesting to you? Is there something in particular that you’ve learned in class that relates to this topic that you could explore with your research? Watch the following video [3:10] to see how to recognize if your topic is too broad or too specific, and to learn some tips on what to do: Note: Turn on closed captions with the “CC” button or use the text transcript if you prefer to read. More Strategies If you are having trouble selecting a topic or narrowing down your topic, here are some strategies that can help: - Scan your course textbook for ideas - Browse some magazines or newspapers for current events - Dive into Wikipedia, or another encyclopedia, and see what sparks your interest - Talk to your instructor, a librarian, or classmates, for ideas and guidance - Browse the “issues” and “topic” pages in library databases that include reference sources, like CQ Researcher or Opposing Viewpoints. These topic pages are similar to Wikipedia and give general background information on a topic and link to more specific information, which is helpful when narrowing down your topic. Some library databases have great features for getting your research started, like pro/con viewpoints, background information, timelines, and bibliographies for further reading. If you are unfamiliar with what library databases your college has a subscription to, ask a librarian for help! Sources Image: “ Narrowing a Topic ” by Teaching & Learning, Ohio State University Libraries is licensed under CC BY 4.0 “ Picking Your Topic IS Research ” by NC State University Libraries is licensed under CC BY-NC-SA 3.0 US	661	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Research_and_Information_Literacy/Introduction_to_College_Research_(Butler_Sargent_and_Smith)/06%3A_Getting_Your_Research_Started/6.01%3A_Choosing_a_Topic	libretexts	libretexts-0000.json.gz:33435	https://human.libretexts.org/Bookshelves/Research_and_Information_Literacy/Introduction_to_College_Research_(Butler_Sargent_and_Smith)/06%3A_Getting_Your_Research_Started/6.01%3A_Choosing_a_Topic
cK0A3Y_FzNkzQNhA	Chemistry 110	Private: Chapter Five Key Terms, Key Equations, Summaries, and Exercises (Chapter 5) Key Terms antibonding orbital molecular orbital located outside of the region between two nuclei; electrons in an antibonding orbital destabilize the molecule bond order number of pairs of electrons between two atoms; it can be found by the number of bonds in a Lewis structure or by the difference between the number of bonding and antibonding electrons divided by two bonding orbital molecular orbital located between two nuclei; electrons in a bonding orbital stabilize a molecule degenerate orbitals orbitals that have the same energy diamagnetism phenomenon in which a material is not magnetic itself but is repelled by a magnetic field; it occurs when there are only paired electrons present homonuclear diatomic molecule molecule consisting of two identical atoms hybrid orbital orbital created by combining atomic orbitals on a central atom hybridization model that describes the changes in the atomic orbitals of an atom when it forms a covalent compound linear combination of atomic orbitals technique for combining atomic orbitals to create molecular orbitals molecular orbital region of space in which an electron has a high probability of being found in a molecule molecular orbital diagram visual representation of the relative energy levels of molecular orbitals molecular orbital theory model that describes the behavior of electrons delocalized throughout a molecule in terms of the combination of atomic wave functions node plane separating different lobes of orbitals, where the probability of finding an electron is zero overlap coexistence of orbitals from two different atoms sharing the same region of space, leading to the formation of a covalent bond paramagnetism phenomenon in which a material is not magnetic itself but is attracted to a magnetic field; it occurs when there are unpaired electrons present pi bond (π bond) covalent bond formed by side-by-side overlap of atomic orbitals; the electron density is found on opposite sides of the internuclear axis s-p mixing change that causes σp orbitals to be less stable than πp orbitals due to the mixing of s and p-based molecular orbitals of similar energies. sigma bond (σ bond) covalent bond formed by overlap of atomic orbitals along the internuclear axis sp hybrid orbital one of a set of two orbitals with a linear arrangement that results from combining one s and one p orbital sp2 hybrid orbital one of a set of three orbitals with a trigonal planar arrangement that results from combining one s and two p orbitals sp3 hybrid orbital one of a set of four orbitals with a tetrahedral arrangement that results from combining one s and three p orbitals sp3d hybrid orbital one of a set of five orbitals with a trigonal bipyramidal arrangement that results from combining one s, three p, and one d orbital sp3d2 hybrid orbital one of a set of six orbitals with an octahedral arrangement that results from combining one s, three p, and two d orbitals valence bond theory description of bonding that involves atomic orbitals overlapping to form σ or π bonds, within which pairs of electrons are shared π bonding orbital molecular orbital formed by side-by-side overlap of atomic orbitals, in which the electron density is found on opposite sides of the internuclear axis π* bonding orbital antibonding molecular orbital formed by out of phase side-by-side overlap of atomic orbitals, in which the electron density is found on both sides of the internuclear axis, and there is a node between the nuclei - bonding orbital molecular orbital in which the electron density is found along the axis of the bond σ* bonding orbital antibonding molecular orbital formed by out-of-phase overlap of atomic orbital along the axis of the bond, generating a node between the nuclei Key Equations - bond order = ⎛number of bonding electron⎞ − ⎛number of antibonding electrons⎞ ⎝⎠⎝⎠ 2 Summary Valence bond theory describes bonding as a consequence of the overlap of two separate atomic orbitals on different atoms that creates a region with one pair of electrons shared between the two atoms. When the orbitals overlap along an axis containing the nuclei, they form a σ bond. When they overlap in a fashion that creates a node along this axis, they form a π bond. Dipole moments can be used to determine partial separations of charges between atoms. We can use hybrid orbitals, which are mathematical combinations of some or all of the valence atomic orbitals, to describe the electron density around covalently bonded atoms. These hybrid orbitals either form sigma (σ) bonds directed toward other atoms of the molecule or contain lone pairs of electrons. We can determine the type of hybridization around a central atom from the geometry of the regions of electron density about it. Two such regions imply sp hybridization; three, sp2 hybridization; four, sp3 hybridization; five, sp3d hybridization; and six, sp3d2 hybridization. Pi (π) bonds are formed from unhybridized atomic orbitals (p or d orbitals). Multiple bonds consist of a σ bond located along the axis between two atoms and one or two π bonds. The σ bonds are usually formed by the overlap of hybridized atomic orbitals, while the π bonds are formed by the side-by-side overlap of unhybridized orbitals. Resonance occurs when there are multiple unhybridized orbitals with the appropriate alignment to overlap, so the placement of π bonds can vary. Molecular orbital (MO) theory describes the behavior of electrons in a molecule in terms of combinations of the atomic wave functions. The resulting molecular orbitals may extend over all the atoms in the molecule. Bonding molecular orbitals are formed by in-phase combinations of atomic wave functions, and electrons in these orbitals stabilize a molecule. Antibonding molecular orbitals result from out-of-phase combinations of atomic wave functions and electrons in these orbitals make a molecule less stable. Molecular orbitals located along an internuclear axis are called σ MOs. They can be formed from s orbitals or from p orbitals oriented in an end-to-end fashion. Molecular orbitals formed from p orbitals oriented in a side-by-side fashion have electron density on opposite sides of the internuclear axis and are called π orbitals. We can describe the electronic structure of diatomic molecules by applying molecular orbital theory to the valence electrons of the atoms. Electrons fill molecular orbitals following the same rules that apply to filling atomic orbitals; Hund’s rule and the Aufbau principle tell us that lower-energy orbitals will fill first, electrons will spread out before they pair up, and each orbital can hold a maximum of two electrons with opposite spins. Materials with unpaired electrons are paramagnetic and attracted to a magnetic field, while those with all-paired electrons are diamagnetic and repelled by a magnetic field. Correctly predicting the magnetic properties of molecules is in advantage of molecular orbital theory over Lewis structures and valence bond theory. Exercises - 1. Explain how σ and π bonds are similar and how they are different. 2. Use valence bond theory to explain the bonding in F2, HF, and ClBr. Sketch the overlap of the atomic orbitals involved in the bonds. 3. Use valence bond theory to explain the bonding in O2. Sketch the overlap of the atomic orbitals involved in the bonds in O2. 4. How many σ and π bonds are present in the molecule HCN? 5. A friend tells you N2 has three π bonds due to overlap of the three p-orbitals on each N atom. Do you agree? 6. Draw the Lewis structures for CO2 and CO, and predict the number of σ and π bonds for each molecule. (a) CO2 (b) CO 5.2 Hybrid Atomic Orbitals 7. Why is the concept of hybridization required in valence bond theory? 8. Give the shape that describes each hybrid orbital set: (a) sp2 (b) sp3d (c) sp (d) sp3d2 9. Explain why a carbon atom cannot form five bonds using sp3d hybrid orbitals. 10. What is the hybridization of the central atom in each of the following? (a) BeH2 (b) SF6 (c) PO43− (d) PCl5 11. A molecule with the formula AB3 could have one of four different shapes. Give the shape and the hybridization of the central A atom for each. 12. Methionine, CH3SCH2CH2CH(NH2)CO2H, is an amino acid found in proteins. The Lewis structure of this compound is shown below. What is the hybridization type of each carbon, oxygen, the nitrogen, and the sulfur? 13. Sulfuric acid is manufactured by a series of reactions represented by the following equations: S8(𝑠)+8O2(𝑔)⟶8SO2(𝑔) 2SO2(𝑔)+O2(𝑔)⟶2SO3(𝑔) SO3(𝑔)+H2O(𝑙)⟶H2SO4(𝑙)Draw a Lewis structure, predict the molecular geometry by VSEPR, and determine the hybridization of sulfur for the following: (a) circular S8 molecule (b) SO2 molecule (c) SO3 molecule (d) H2SO4 molecule (the hydrogen atoms are bonded to oxygen atoms) 14. Two important industrial chemicals, ethene, C2H4, and propene, C3H6, are produced by the steam (or thermal) cracking process: 2C3H8(𝑔)⟶C2H4(𝑔)+C3H6(𝑔)+CH4(𝑔)+H2(𝑔) For each of the four carbon compounds, do the following: (a) Draw a Lewis structure. (b) Predict the geometry about the carbon atom. (c) Determine the hybridization of each type of carbon atom. 15. Analysis of a compound indicates that it contains 77.55% Xe and 22.45% F by mass. (a) What is the empirical formula for this compound? (Assume this is also the molecular formula in responding to the remaining parts of this exercise). (b) Write a Lewis structure for the compound. (c) Predict the shape of the molecules of the compound. (d) What hybridization is consistent with the shape you predicted? 16. Consider nitrous acid, HNO2 (HONO). (a) Write a Lewis structure. (b) What are the electron pair and molecular geometries of the internal oxygen and nitrogen atoms in the HNO2 molecule? (c) What is the hybridization on the internal oxygen and nitrogen atoms in HNO2? 17. Strike-anywhere matches contain a layer of KClO3 and a layer of P4S3. The heat produced by the friction of striking the match causes these two compounds to react vigorously, which sets fire to the wooden stem of the match. KClO3 contains the ClO3− ion. P4S3 is an unusual molecule with the skeletal structure. (a) Write Lewis structures for P4S3 and the ClO3– ion. (b) Describe the geometry about the P atoms, the S atom, and the Cl atom in these species. (c) Assign a hybridization to the P atoms, the S atom, and the Cl atom in these species. (d) Determine the oxidation states and formal charge of the atoms in P4S3 and the ClO3– ion. 18. Identify the hybridization of each carbon atom in the following molecule. (The arrangement of atoms is given; you need to determine how many bonds connect each pair of atoms.) 19. Write Lewis structures for NF3 and PF5. On the basis of hybrid orbitals, explain the fact that NF3, PF3, and PF5 are stable molecules, but NF5 does not exist. 20. In addition to NF3, two other fluoro derivatives of nitrogen are known: N2F4 and N2F2. What shapes do you predict for these two molecules? What is the hybridization for the nitrogen in each molecule? 5.3 Multiple Bonds 21. The bond energy of a C–C single bond averages 347 kJ mol−1; that of a C≡C triple bond averages 839 kJ mol−1. Explain why the triple bond is not three times as strong as a single bond. 22. For the carbonate ion, CO32−, draw all of the resonance structures. Identify which orbitals overlap to create each bond. 23. A useful solvent that will dissolve salts as well as organic compounds is the compound acetonitrile, H3CCN. It is present in paint strippers. (a) Write the Lewis structure for acetonitrile, and indicate the direction of the dipole moment in the molecule. (b) Identify the hybrid orbitals used by the carbon atoms in the molecule to form σ bonds. (c) Describe the atomic orbitals that form the π bonds in the molecule. Note that it is not necessary to hybridize the nitrogen atom. 24. For the molecule allene, H2C=C=CH2, give the hybridization of each carbon atom. Will the hydrogen atoms be in the same plane or perpendicular planes? 25. Identify the hybridization of the central atom in each of the following molecules and ions that contain multiple bonds: (a) ClNO (N is the central atom) (b) CS2 (c) Cl2CO (C is the central atom) (d) Cl2SO (S is the central atom) (e) SO2F2 (S is the central atom) (f) XeO2F2 (Xe is the central atom) (g) ClOF2+ (Cl is the central atom) 26. Describe the molecular geometry and hybridization of the N, P, or S atoms in each of the following compounds. (a) H3PO4, phosphoric acid, used in cola soft drinks (b) NH4NO3, ammonium nitrate, a fertilizer and explosive (c) S2Cl2, disulfur dichloride, used in vulcanizing rubber (d) K4[O3POPO3], potassium pyrophosphate, an ingredient in some toothpastes 27. For each of the following molecules, indicate the hybridization requested and whether or not the electrons will be delocalized: (a) ozone (O3) central O hybridization (b) carbon dioxide (CO2) central C hybridization (c) nitrogen dioxide (NO2) central N hybridization (d) phosphate ion (PO43−) central P hybridization 28. For each of the following structures, determine the hybridization requested and whether the electrons will be delocalized: (a) Hybridization of each carbon (b) Hybridization of sulfur (c) All atoms 29. Draw the orbital diagram for carbon in CO2 showing how many carbon atom electrons are in each orbital. 5.4 Molecular Orbital Theory 30. Sketch the distribution of electron density in the bonding and antibonding molecular orbitals formed from two s orbitals and from two p orbitals. 31. How are the following similar, and how do they differ? (a) σ molecular orbitals and π molecular orbitals (b) ψ for an atomic orbital and ψ for a molecular orbital (c) bonding orbitals and antibonding orbitals 32. If molecular orbitals are created by combining five atomic orbitals from atom A and five atomic orbitals from atom B combine, how many molecular orbitals will result? 33. Can a molecule with an odd number of electrons ever be diamagnetic? Explain why or why not. 34. Can a molecule with an even number of electrons ever be paramagnetic? Explain why or why not. 35. Why are bonding molecular orbitals lower in energy than the parent atomic orbitals? 36. Calculate the bond order for an ion with this configuration: (σ2𝑠)2(σ∗2𝑠)2(σ2𝑝𝑥)2(π2𝑝𝑦,π2𝑝𝑧)4(π∗2𝑝𝑦,π∗2𝑝𝑧)3 37. Explain why an electron in the bonding molecular orbital in the H2 molecule has a lower energy than an electron in the 1s atomic orbital of either of the separated hydrogen atoms. 38.Predict the valence electron molecular orbital configurations for the following, and state whether they will be stable or unstable ions. (a) Na22+ (b) Mg22+ (c) Al22+ (d) Si22+ (e) P22+ (f) S22+ (g) F22+ (h) Ar22+ 39. Determine the bond order of each member of the following groups, and determine which member of each group is predicted by the molecular orbital model to have the strongest bond. (a) H2, H2+, H2− (b) O2, O22+, O22− (c) Li2, Be2+, Be2 (d) F2, F2+, F2− (e) N2, N2+, N2− 40. For the first ionization energy for an N2 molecule, what molecular orbital is the electron removed from? 41. Compare the atomic and molecular orbital diagrams to identify the member of each of the following pairs that has the highest first ionization energy (the most tightly bound electron) in the gas phase: (a) H and H2 (b) N and N2 (c) O and O2 (d) C and C2 (e) B and B2 42. Which of the period 2 homonuclear diatomic molecules are predicted to be paramagnetic? 43. A friend tells you that the 2s orbital for fluorine starts off at a much lower energy than the 2s orbital for lithium, so the resulting σ2s molecular orbital in F2 is more stable than in Li2. Do you agree? 44. True or false: Boron contains 2s22p1 valence electrons, so only one p orbital is needed to form molecular orbitals. 45. What charge would be needed on F2 to generate an ion with a bond order of 2? 46. Predict whether the MO diagram for S2 would show s-p mixing or not. 47. Explain why N22+ is diamagnetic, while O24+, which has the same number of valence electrons, is paramagnetic. 48. Using the MO diagrams, predict the bond order for the stronger bond in each pair: (a) B2 or B2+ (b) F2 or F2+ (c) O2 or O22+ (d) C2+ or C2−	3,523	common-pile/pressbooks_filtered	https://psu.pb.unizin.org/eshanichemistry110/chapter/key-terms-key-equations-and-exercises-chapter-5/	pressbooks	pressbooks-0000.json.gz:92806	https://psu.pb.unizin.org/eshanichemistry110/chapter/key-terms-key-equations-and-exercises-chapter-5/
3052tkX2oeZaUgps	Jane Eyre	Jane Eyre Chapter IX But the privations, or rather the hardships, of Lowood lessened. Spring drew on—she was indeed already come; the frosts of winter had ceased; its snows were melted, its cutting winds ameliorated. My wretched feet, flayed and swollen to lameness by the sharp air of January, began to heal and subside under the gentler breathings of April; the nights and mornings no longer by their Canadian temperature froze the very blood in our veins; we could now endure the play-hour passed in the garden. Sometimes, on a sunny day it began even to be pleasant and genial, and a greenness grew over those brown beds, which, freshening daily, suggested the thought that Hope traversed them at night, and left each morning brighter traces of her steps. Flowers peeped out amongst the leaves; snow-drops, crocuses, purple auriculas, and golden-eyed pansies. On Thursday afternoons (half-holidays) we now took walks, and found still sweeter flowers opening by the wayside, under the hedges. I discovered, too, that a great pleasure—an enjoyment which the horizon only bounded—lay all outside the high and spike-guarded walls of our garden. This pleasure consisted in prospect of noble summits girdling a great hill-hollow, rich in verdure and shadow; in a bright beck, full of dark stones and sparkling eddies. How different had this scene looked when I viewed it laid out beneath the iron sky of winter, stiffened in frost, shrouded with snow!— when mists as chill as death wandered to the impulse of east winds along those purple peaks, and rolled down “ing” and holm till they blended with the frozen fog of the beck! That beck itself was then a torrent, turbid and curbless; it tore asunder the wood, and sent a raving sound through the air, often thickened with wild rain or whirling sleet; and for the forest on its banks, that showed only ranks of skeletons. April advanced to May. A bright serene May it was; days of blue sky, placid sunshine, and soft western or southern gales filled up its duration. And now vegetation matured with vigour; Lowood shook loose its tresses; it became all green, all flowery; its great elm, ash, and oak skeletons were restored to majestic life; woodland plants sprang up profusely in its recesses; unnumbered varieties of moss filled its hollows, and it made a strange ground-sunshine out of the wealth of its wild primrose plants; I have seen their pale gold gleam in overshadowed spots like scatterings of the sweetest lustre. All this I enjoyed often and fully, free, unwatched, and almost alone; for this unwonted liberty and pleasure there was a cause, to which it now becomes my task to advert. Have I not described a pleasant site for a dwelling, when I speak of it as bosomed in hill and wood, and rising from the verge of a stream? Assuredly, pleasant enough; but whether healthy or not is another question. That forest-dell, where Lowood lay, was the cradle of fog and fog-bred pestilence; which, quickening with the quickening spring, crept into the Orphan Asylum, breathed typhus through its crowded schoolroom and dormitory, and, ere May arrived, transformed the seminary into an hospital. Semi-starvation and neglected colds had predisposed most of the pupils to receive infection. Forty-five out of the eighty girls lay ill at one time. Classes were broken up, rules relaxed. The few who continued well were allowed almost unlimited license; because the medical attendant insisted on the necessity of frequent exercise to keep them in health; and had it been otherwise, no one had leisure to watch or restrain them. Miss Temple’s whole attention was absorbed by the patients; she lived in the sick-room, never quitting it except to snatch a few hours’ rest at night. The teachers were fully occupied with packing up and making other necessary preparations for the departure of those girls who were fortunate enough to have friends and relations able and willing to remove them from the seat of contagion. Many, already smitten, went home only to die; some died at the school, and were buried quietly and quickly, the nature of the malady forbidding delay. While disease had thus become an inhabitant of Lowood, and death its frequent visitor; while there was gloom and fear within its walls; while its rooms and passages steamed with hospital smells—the drug and the pastille striving vainly to overcome the effluvia of mortality, that bright May shone unclouded over the bold hills and beautiful woodland out of doors. Its garden, too, glowed with flowers; hollyhocks had sprung up tall as trees, lilies had opened, tulips and roses were in bloom; the borders of the little beds were gay with pink thrift and crimson double daisies; the sweetbriars gave out, morning and evening, their scent of spice and apples; and these fragrant treasures were all useless for most of the inmates of Lowood, except to furnish now and then a handful of herbs and blossoms to put in a coffin. But I, and the rest who continued well, enjoyed fully the beauties of the scene and season; they let us ramble in the wood, like gipsies, from morning till night; we did what we liked—went where we liked; we lived better too. Mr. Brocklehurst and his family never came near Lowood now; household matters were not scrutinised into; the cross housekeeper was gone, driven away by the fear of infection; her successor, who had been matron at the Lowton Dispensary, unused to the ways of her new abode, provided with comparative liberality. Besides, there were fewer to feed; the sick could eat little; our breakfast-basins were better filled; when there was no time to prepare a regular dinner, which often happened, she would give us a large piece of cold pie, or a thick slice of bread and cheese, and this we carried away with us to the wood, where we each chose the spot we liked best, and dined sumptuously. My favourite seat was a smooth and broad stone, rising white and dry from the very middle of the beck, and only to be got at by wading through the water; a feat I accomplished barefoot. The stone was just broad enough to accommodate, comfortably, another girl and me, at that time my chosen comrade—one Mary Ann Wilson; a shrewd, observant personage, whose society I took pleasure in, partly because she was witty and original, and partly because she had a manner which set me at my ease. Some years older than I, she knew more of the world, and could tell me many things I liked to hear. With her my curiosity found gratification. To my faults, also, she gave ample indulgence, never imposing curb or rein on anything I said. She had a turn for narrative—I for analysis; she liked to inform—I to question; so we got on swimmingly together, deriving much entertainment, if not much improvement, from our mutual intercourse. And where, meantime, was Helen Burns? Why did I not spend these sweet days of liberty with her? Had I forgotten her? or was I so worthless as to have grown tired of her pure society? Surely the Mary Ann Wilson I have mentioned was inferior to my first acquaintance; she could only tell me amusing stories, and reciprocate any racy and pungent gossip I chose to indulge in; while, if I have spoken truth of Helen, she was qualified to give those who enjoyed the privilege of her converse, a taste of far higher things. True, reader; and I knew and felt this: and though I am a defective being, with many faults and few redeeming points, yet I never tired of Helen Burns; nor ever ceased to cherish for her a sentiment of attachment, as strong, tender, and respectful as any that ever animated my heart. How could it be otherwise, when Helen, at all times and under all circumstances, evinced for me a quiet and faithful friendship, which ill-humour never soured, nor irritation never troubled? But Helen was ill at present; for some weeks she had been removed from my sight to I knew not what room upstairs. She was not, I was told, in the hospital portion of the house with the fever patients; for her complaint was consumption, not typhus; and by consumption I, in my ignorance, understood something mild, which time and care would be sure to alleviate. I was confirmed in this idea by the fact of her once or twice coming downstairs on very warm sunny afternoons, and being taken by Miss Temple into the garden; but, on these occasions, I was not allowed to go and speak to her; I only saw her from the schoolroom window, and then not distinctly; for she was much wrapped up, and sat at a distance under the verandah. One evening, in the beginning of June, I had stayed out very late with Mary Ann in the wood; we had, as usual, separated ourselves from the others, and had wandered far; so far that we lost our way, and had to ask it at a lonely cottage, where a man and woman lived, who looked after a herd of half-wild swine that fed on the mast in the wood. When we got back, it was after moonrise; a pony, which we knew to be the surgeon’s, was standing at the garden door. Mary Ann remarked that she supposed some one must be very ill, as Mr. Bates had been sent for at that time of the evening. She went into the house; I stayed behind a few minutes to plant in my garden a handful of roots I had dug up in the forest, and which I feared would wither if I left them till the morning. This done, I lingered yet a little longer; the flowers smelt so sweet as the dew fell; it was such a pleasant evening, so serene, so warm; the still glowing west promised so fairly another fine day on the morrow; the moon rose with such majesty in the grave east. This world is pleasant—it would be dreary to be called from it, and to have to go who knows where?” And then my mind made its first earnest effort to comprehend what had been infused into it concerning heaven and hell, and for the first time it recoiled, baffled; and for the first time glancing behind, on each side, and before it, it saw all round an unfathomed gulf; it felt the one point where it stood—the present; all the rest was formless cloud and vacant depth; and it shuddered at the thought of tottering, and plunging amid that chaos. While pondering this new idea, I heard the front door open; Mr. Bates came out, and with him was a nurse. After she had seen him mount his horse and depart, she was about to close the door, but I ran up to her. “How is Helen Burns?” “Very poorly,” was the answer. “Is it her Mr. Bates has been to see?” “Yes.” “And what does he say about her?” “He says she’ll not be here long.” This phrase, uttered in my hearing yesterday, would have only conveyed the notion that she was about to be removed to Northumberland, to her own home. I should not have suspected that it meant she was dying; but I knew instantly now! It opened clear on my comprehension that Helen Burns was numbering her last days in this world, and that she was going to be taken to the region of spirits, if such region there were. I experienced a shock of horror, then a strong thrill of grief, then a desire—a necessity to see her; and I asked in what room she lay. “She is in Miss Temple’s room,” said the nurse. “May I go up and speak to her?” “Oh no, child! It is not likely; and now it is time for you to come in; you’ll catch the fever if you stop out when the dew is falling.” The nurse closed the front door; I went in by the side entrance which led to the schoolroom. I was just in time; it was nine o’clock, and Miss Miller was calling the pupils to go to bed. It might be two hours later, probably near eleven, when I—not having been able to fall asleep, and deeming, from the perfect silence of the dormitory, that my companions were all wrapt in profound repose—rose softly, put on my frock over my nightdress, and, without shoes, crept from the apartment, and set off in quest of Miss Temple’s room. It was quite at the other end of the house; but I knew my way; and the light of the unclouded summer moon, entering here and there at passage windows, enabled me to find it without difficulty. An odour of camphor and burnt vinegar warned me when I came near the fever room; and I passed its door quickly, fearful lest the nurse who sat up all night should hear me. I dreaded being discovered and sent back; for I must see Helen,—I must embrace her before she died,—I must give her one last kiss, exchange with her one last word. Having descended a staircase, traversed a portion of the house below, and succeeded in opening and shutting, without noise, two doors, I reached another flight of steps; these I mounted, and then just opposite to me was Miss Temple’s room. A light shone through the keyhole and from under the door; a profound stillness pervaded the vicinity. Coming near, I found the door slightly ajar; probably to admit some fresh air into the close abode of sickness. Indisposed to hesitate, and full of impatient impulses—soul and senses quivering with keen throes—I put it back and looked in. My eye sought Helen, and feared to find death. I saw the outline of a form under the clothes, but the face was hid by the hangings. The nurse I had spoken to in the garden sat in an easy-chair asleep; an unsnuffed candle burnt dimly on the table. Miss Temple was not to be seen; I knew afterwards that she had been called to a delirious patient in the fever-room. I advanced; then paused by the crib side. My hand was on the curtain, but I preferred speaking before I withdrew it. I still recoiled at the dread of seeing a corpse. “Helen!” I whispered softly, “are you awake?” She stirred herself, put back the curtain, and I saw her face, pale, wasted, but quite composed. She looked so little changed that my fear was instantly dissipated. “Can it be you, Jane?” she asked, in her own gentle voice. “Oh!” I thought, “she is not going to die; they are mistaken; she could not speak and look so calmly if she were.” I got on to her crib and kissed her. Her forehead was cold, and her cheek both cold and thin, and so were her hand and wrist; but she smiled as of old. “Why are you come here, Jane? It is past eleven o’clock; I heard it strike some minutes since.” “I came to see you, Helen; I heard you were very ill, and I could not sleep till I had spoken to you.” “You came to bid me goodbye, then; you are just in time probably.” “Are you going somewhere, Helen? Are you going home?” “Yes; to my long home—my last home.” “No, no, Helen!” I stopped, distressed. While I tried to devour my tears, a fit of coughing seized Helen; it did not, however, wake the nurse; when it was over, she lay some minutes exhausted; then she whispered: “Jane, your little feet are bare; lie down and cover yourself with my quilt.” I did so; she put her arm over me, and I nestled close to her. After a long silence, she resumed, still whispering: “I am very happy, Jane; and when you hear that I am dead, you must be sure and not grieve; there is nothing to grieve about. I leave no one to regret me much; I have only a father; and he is lately married, and will not miss me. By dying young, I shall escape great sufferings. I had not qualities or talents to make my way very well in the world; I should have been continually at fault.” “But where are you going to, Helen? Can you see? Do you know?” “I believe; I have faith; I am going to God.” “Where is God? What is God?” “My Maker and yours, who will never destroy what He created. I rely implicitly on His power, and confide wholly in His goodness; I count the hours till that eventful one arrives which shall restore me to Him, reveal Him to me.” “You are sure, then, Helen, that there is such a place as heaven, and that our souls can get to it when we die?” “I am sure there is a future state; I believe God is good; I can resign my immortal part to Him without any misgiving. God is my father; God is my friend; I love Him; I believe He loves me.” “And shall I see you again, Helen, when I die?” “You will come to the same region of happiness; be received by the same mighty, universal Parent, no doubt, dear Jane.” Again I questioned, but this time only in thought. “Where is that region? Does it exist?” And I clasped my arms closer round Helen; she seemed dearer to me than ever; I felt as if I could not let her go; I lay with my face hidden on her neck. Presently she said, in the sweetest tone: “How comfortable I am! That last fit of coughing has tired me a little; I feel as if I could sleep; but don’t leave me, Jane; I like to have you near me.” “I’ll stay with you, dear Helen; no one shall take me way.” “Are you warm, darling?” “Yes.” “Goodnight, Jane.” “Goodnight, Helen.” She kissed me, and I her, and we both soon slumbered. When I awoke it was day; an unusual movement roused me; I looked up; I was in somebody’s arms; the nurse held me; she was carrying me through the passage back to the dormitory. I was not reprimanded for leaving my bed; people had something else to think about; no explanation was afforded then to my many questions; but a day or two afterwards I learned that Miss Temple, on returning to her own room at dawn, had found me laid in the little crib; my face against Helen Burns’s shoulder, my arms round her neck. I was asleep, and Helen was—dead. Her grave is in Brocklebridge churchyard; for fifteen years after her death it was only covered by a grassy mound; but now a grey marble tablet marks the spot, inscribed with her name, and the word “Resurgam.”	4,101	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/janeeyre/chapter/9/	pressbooks	pressbooks-0000.json.gz:90143	https://pressbooks.library.torontomu.ca/janeeyre/chapter/9/
ibzf-BiSzsC8xB5-	Pathways to College Success	Primary Navigation Want to create or adapt books like this? Learn more about how Pressbooks supports open publishing practices. Book Contents Navigation About This Book 1. Passion Dave Dillon 2. What’s College For? Alise Lamoreaux, Dave Dillon 3. Discovering Your Ikigai: Finding Purpose in College and Career Joel Gladd 4. Time Management Theory 5. SMART Goals and Gantt Charts 6. The Importance of Time and Why We Procrastinate 7. Time Management Strategies 8. Communication and Technology 9. The Context of Communication 10. Group Projects and Teamwork Liza Long 11. Reading and Notetaking: Introduction 12. The Nature and Types of Reading 13. Effective Reading Strategies 14. Taking Notes 15. Introduction to Studying and Test-Taking 16. Note-taking 17. CWI Tutoring Services and Writing Center 18. Studying, Memory, and Test Taking: Introduction 19. Memory 20. Studying 21. Test Taking 22. Writing Summaries 23. Degree Planning and Goal-Setting: Introduction 24. Defining Values and Setting Goals 25. Planning Your Degree Path 26. Making a SMART Plan 27. Developing a Reflective Practice 28. A Brief Look at American Higher Education 29. Student Advising at CWI 30. Networking Lumen Learning and Linda (Bruce) Hill 31. Resume and Cover Letters 32. Pathways Plan A, B, and C 33. Work-Based Learning Center at CWI 34. Introduction to Health and Wellness 35. Taking Care of Your Physical Health 36. Sleep 37. Taking Care of Your Emotional Health 38. Taking Care of Your Mental Health 39. Maintaining Healthy Relationships 40. Research Skills in the Workplace: A Brief Overview 41. What Is a Research Question? 42. Primary Research and Research Methods 43. Notes on ChatGPT, Research, and Academic Integrity 44. PowerPoint Basics 45. How Large Language Models (LLMs) like ChatGPT Work 46. How to Prompt AI Chatbots 47. Getting Started with AI Tools and Platforms 48. Principles for Using AI in the Classroom and How to Acknowledge It Below are some YouTube videos to help with getting started on your PowerPoint. Previous/next navigation Pathways to College Success Copyright © by CWI 101 Leaders is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.	448	common-pile/pressbooks_filtered	https://cwi.pressbooks.pub/pathwaystocollegesuccess/chapter/powerpoint-basics/	pressbooks	pressbooks-0000.json.gz:93588	https://cwi.pressbooks.pub/pathwaystocollegesuccess/chapter/powerpoint-basics/
qidcpSlPlnZhoiEt	Astronomy and General Physics Considered with Reference to Natural Theology	TRANSCRIBER’S NOTE Italic text is denoted by _underscores_. Footnote anchors are denoted by [number], and the footnotes have been placed at the end of the book. Some minor changes to the text are noted at the end of the book. BRIDGEWATER TREATISES. CAREY, LEA & BLANCHARD HAVE PUBLISHED, ASTRONOMY AND GENERAL PHYSICS, considered with reference to Natural Theology, by the Rev. WILLIAM WHEWELL, M. A., Fellow and Tutor of Trinity College, Cambridge; being the _Third Part_ of the Bridgewater Treatises on the Power, Wisdom, and Goodness of God, as manifested in the Creation. The series of Treatises, of which the present is one, is published under the following circumstances:-- The Right Honourable and Rev. FRANCIS HENRY, Earl of Bridgewater, died in the month of February, 1825; he directed certain trustees therein named, to invest in the public funds, the sum of eight thousand pounds sterling; this sum, with the accruing dividends thereon, to be held at the disposal of the President, for the time being, of the Royal Society of London, to be paid to the person or persons nominated by him. The Testator farther directed, that the person or persons selected by the said President, should be appointed to write, print and publish one thousand copies of a work, on the Power, Wisdom, and Goodness of God, as manifested in the Creation; illustrating such work, by all reasonable arguments, as, for instance, the variety and formation of God’s creatures in the Animal, Vegetable, and Mineral Kingdoms; the effect of digestion, and, thereby, of conversion; the construction of the hand of man, and an infinite variety of other arguments; as also by discoveries, ancient and modern, in arts, sciences, and the whole extent of literature. He desired, moreover, that the profits arising from the sale of the works so published, should be paid to the authors of the works. The late President of the Royal Society, DAVIES GILBERT, Esq., requested the assistance of his Grace, the Archbishop of Canterbury, and of the Bishop of London, in determining upon the best mode of carrying into effect, the intentions of the Testator. Acting with their advice, and with the concurrence of a nobleman immediately connected with the deceased, Mr. Davies Gilbert appointed the following eight gentlemen to write separate Treatises in the different branches of the subjects here stated:-- I. The Adaptation of External Nature to the Moral and Intellectual Constitution of Man, by the Rev. THOMAS CHALMERS, D. D., Professor of Divinity in the University of Edinburgh. II. The Adaptation of External Nature to the Physical Condition of Man, by JOHN KIDD, M. D., F. R. S., Regius Professor of Medicine in the University of Oxford. III. Astronomy and General Physics, considered with reference to Natural Theology, by the Rev. WILLIAM WHEWELL, M. A., F. R. S., Fellow of Trinity College, Cambridge. IV. The Hand: its Mechanism and Vital Endowments as evincing Design, by Sir CHARLES BELL, K. H., F. R. S. V. Animal and Vegetable Physiology, by PETER MARK ROGET, M. D., Fellow of and Secretary to the Royal Society. VI. Geology and Mineralogy, by the Rev. WILLIAM BUCKLAND, D. D., F. R. S., Canon of Christ Church, and Professor of Geology in the University of Oxford. VII. The History, Habits, and Instincts of Animals, by the Rev. WILLIAM KIRBY, M. A., F. R. S. VIII. Chemistry, Meteorology, and the Function of Digestion, by WILLIAM PROUT, M. D., F. R. S. _The whole of these Treatises are nearly finished, and will be put to press as soon as received, and published in a cheap and handsome form._ THE PRINCIPLES OF CHRISTIAN PHILOSOPHY; containing the Doctrines, Duties, Admonitions, and Consolations of the Christian Religion, by JOHN BURNS, M. D., F. R. S. From the fourth London edition. In the press. CONVERSATIONS WITH LORD BYRON ON THE SUBJECT OF RELIGION. By J. KENNEDY, M. D. 12mo. GLEANINGS IN NATURAL HISTORY, WITH LOCAL RECOLLECTIONS. By EDWARD JESSE, Esq. To which are added, Maxims and Hints for Anglers. From the second London edition, in one volume, being a Companion to the Journal of a Naturalist. We have occasionally selected a paragraph from a very pretty volume, by Mr. Jesse, published under the above title. The author lives in the neighbourhood of Kew, and like Mr. White of Selborne,--who made a small village of Hampshire one of the most interesting spots to the lover of nature, by his ample descriptions of the natural objects which he saw around him,--Mr. Jesse has rendered his walks a vehicle for much instruction and amusement to himself and to others. He principally confines his attention to zoology--the most generally attractive of the departments of natural history; and he looks upon the animal world with so much practical wisdom, being disposed to be happy himself, and to see every creature around him happy, that there are few persons who will not read his slight sketches with improvement to their hearts and understandings.--_Penny Magazine._ THE MECHANISM OF THE HEAVENS. By Mrs. SOMERVILLE. In 18mo. Is it asking too much of Mrs. Somerville to express a hope that she will allow this beautiful preliminary Dissertation to be printed separately for the delight and instruction of thousands of readers, young and old, who cannot understand, or are too indolent to apply themselves to the more elaborate parts of the work? If she will do this, we hereby promise to exert our best endeavours to make its merits known.--_Literary Gazette._ SALMONIA; OR, DAYS OF FLY FISHING. By Sir H. DAVY. We are surprised in meeting with an American reprint of this delightful volume, that a work so universally popular has not been before republished in this country.--_N. Y. American._ One of the most delightful labours of leisure ever seen; not a few of the most beautiful phenomena of nature are here lucidly explained.--_Gent. Magazine._ THE NATURAL HISTORY OF SELBORNE. By the late Rev. GILBERT WHITE, A. M., Fellow of the Oriel College, Oxford; with additions by Sir WILLIAM JARDINE, Bart. F. R. S., E. F. L. S., M. W. S., author of “Illustrations of Ornithology.” White’s History of Selborne, the most fascinating piece of rural writing and sound English philosophy that has ever issued from the press.--_Athenæum._ JOURNAL OF A NATURALIST. With Plates. ----Plants, trees, and stones we note; Birds, insects, beasts and rural things. We again most strongly recommend this little unpretending volume to the attention of every lover of nature, and more particularly of our country readers. It will induce them, we are sure, to examine more closely than they have been accustomed to do, into the objects of animated nature, and such examination will prove one of the most innocent, and the most satisfactory sources of gratification and amusement. It is a book that ought to find its way into every rural drawing-room in the kingdom, and one that may safely be placed in every lady’s boudoir, be her rank and station in life what they may.--_Quart. Review_, No. LXXVIII. This is a most delightful book on the most delightful of all studies. We are acquainted with no previous work which bears any resemblance to this, except “White’s History of Selborne,” the most fascinating piece of rural writing and sound English philosophy that ever issued from the press.--_Athenæum._ THE FAMILY CABINET ATLAS, constructed upon an original plan: being a Companion to the Encyclopædia Americana, Cabinet Cyclopædia, Family Library, Cabinet Library, &c. [This Atlas comprises, in a volume of the Family Library size, nearly one hundred Maps and Tables, which present equal to _fifty thousand names of places_; a body of information three times as extensive as that supplied by the generality of _Quarto Atlases_.] This beautiful and most useful little volume, says the Literary Gazette, is a perfect picture of elegance, containing a vast sum of geographical information. A more instructive little present, or a gift better calculated to be long preserved and often referred to, could not be offered to favoured youth of either sex. Its cheapness, we must add, is another recommendation; for, although this elegant publication contains one hundred beautiful engravings, it is issued at a price that can be no obstacle to its being procured by every parent and friend to youth. This Atlas far surpasses any thing of the kind which we have seen, and is made to suit the popular libraries which Dr. Lardner and Mr. Murray are now sending into every family in the empire.--_Monthly Review._ Its very ingenious method of arrangement secures to the geographical student the information for which hitherto he has been obliged to resort to works of the largest dimensions.--_Athenæum._ THE RECTORY OF VALEHEAD. By the Rev. ROBERT WILSON EVANS, M. A. Universally and cordially do we recommend this delightful volume. Impressed with the genuine spirit of Christianity; a diary, as it were, of the feelings, hopes, and sorrows of a family,--it comes home to all, either in sympathy or example. It is a beautiful picture of a religious household, influencing to excellence all within its sphere. We believe no person could read this work, and not be better for its pious touching lessons.--_Literary Gaz._ We fearlessly pronounce this delightful little volume to be not only one of the most faultless, but every way valuable works it has ever fallen to our lot to recommend to public perusal.--_Stamford Herald._ The Rectory of Valehead is a beautiful model of domestic life in the Christian home of a well-regulated family, and combines literary amusement with the most refined and intellectual improvement.--_Scotsman._ A GENERAL VIEW OF THE PROGRESS OF ETHICAL PHILOSOPHY, chiefly during the Seventeenth and Eighteenth Centuries. By Sir JAMES MACKINTOSH, M. P. In 8vo. The best offspring of the pen of an author who in philosophical spirit, knowledge and reflection, richness of moral sentiment, and elegance of style, has altogether no superior--perhaps no equal--among his contemporaries. Some time ago we made copious extracts from the beautiful work. We could not recommend the whole too earnestly.--_National Gazette._ THE BOOK OF THE SEASONS; OR THE CALENDAR OF NATURE. By WILLIAM HOWITT. In one volume, 12mo. THE BRIDGEWATER TREATISES ON THE POWER, WISDOM, AND GOODNESS OF GOD AS MANIFESTED IN THE CREATION. TREATISE III. ON ASTRONOMY AND GENERAL PHYSICS. BY THE REV. W. WHEWELL. ET HÆC DE DEO, DE QUO UTIQUE EX PHÆNOMENIS DISSERERE AD PHILOSOPHIAM NATURALEM PERTINET. NEWTON, CONCLUSION OF THE PRINCIPIA. ASTRONOMY AND GENERAL PHYSICS CONSIDERED WITH REFERENCE TO NATURAL THEOLOGY. BY THE REV. WILLIAM WHEWELL, M. A. FELLOW AND TUTOR OF TRINITY COLLEGE, CAMBRIDGE. Philadelphia: CAREY, LEA & BLANCHARD, CHESTNUT STREET. 1833. TO THE RIGHT HONOURABLE AND RIGHT REVEREND CHARLES JAMES, LORD BISHOP OF LONDON. MY LORD-- I owe it to you that I was selected for the task attempted in the following pages, a distinction which I feel to be honourable; and on this account alone I should have a peculiar pleasure in dedicating the work to your lordship. I do so with additional gratification on another account: the Treatise has been written within the walls of the College of which your lordship was formerly a resident member, and its merits, if it have any, are mainly due to the spirit and habits of the place. The society is always pleased and proud to recollect that a person of the eminent talents and high character of your lordship is one of its members; and I am persuaded that any effort in the cause of letters and religion coming from that quarter, will have for you an interest beyond what it would otherwise possess. The subject proposed to me was limited: my prescribed object is to lead the friends of religion to look with confidence and pleasure on the progress of the physical sciences, by showing how admirably every advance in our knowledge of the universe harmonizes with the belief of a most wise and good God. To do this effectually may be, I trust, a useful labour. Yet, I feel most deeply, what I would take this occasion to express, that this, and all that the speculator concerning Natural Theology can do, is utterly insufficient for the great ends of Religion; namely, for the purpose of reforming men’s lives, of purifying and elevating their characters, of preparing them for a more exalted state of being. It is the need of something fitted to do this, which gives to religion its vast and incomparable importance; and this can, I well know, be achieved only by that Revealed Religion of which we are ministers, but on which the plan of the present work did not allow me to dwell. That Divine Providence may prosper the labours of your lordship, and of all who are joined with you in the task of maintaining and promoting _this_ Religion, is, my lord, the earnest wish and prayer of Your very faithful And much obliged servant, WILLIAM WHEWELL. Trinity College, Cambridge, Feb. 25, 1833. NOTICE. The series of Treatises, of which the present is one, is published under the following circumstances: The RIGHT HONOURABLE and REVEREND FRANCIS HENRY, EARL OF BRIDGEWATER, died in the month of February, 1829; and by his last Will and Testament, bearing date the 25th of February, 1825, he directed certain Trustees therein named to invest in the public funds the sum of Eight thousand pounds sterling; this sum, with the accruing dividends thereon, to be held at the disposal of the President, for the time being, of the Royal Society of London, to be paid to the person or persons nominated by him. The Testator further directed, that the person or persons selected by the said President should be appointed to write, print, and publish one thousand copies of a work _On the Power, Wisdom, and Goodness of God, as manifested in the Creation; illustrating such work by all reasonable arguments, as for instance the variety and formation of God’s creatures in the animal, vegetable, and mineral kingdoms; the effect of digestion, and thereby of conversion; the construction of the hand of man, and an infinite variety of other arguments; as also by discoveries ancient and modern, in arts, sciences, and the whole extent of literature_. He desired, moreover, that the profits arising from the sale of the works so published should be paid to the authors of the works. The late President of the Royal Society, Davies Gilbert, Esq. requested the assistance of his Grace the Archbishop of Canterbury and of the Bishop of London, in determining upon the best mode of carrying into effect the intentions of the Testator. Acting with their advice, and with the concurrence of a nobleman immediately connected with the deceased, Mr. Davies Gilbert appointed the following eight gentlemen to write separate Treatises on the different branches of the subject as here stated: THE REV. THOMAS CHALMERS, D. D. Professor of Divinity in the University of Edinburgh. ON THE ADAPTATION OF EXTERNAL NATURE TO THE MORAL AND INTELLECTUAL CONSTITUTION OF MAN. JOHN KID, M. D. F. R. S. Regius Professor of Medicine in the University of Oxford. ON THE ADAPTATION OF EXTERNAL NATURE TO THE PHYSICAL CONDITION OF MAN. THE REV. WILLIAM WHEWELL, M. A. F. R. S. Fellow of Trinity College, Cambridge. ON ASTRONOMY AND GENERAL PHYSICS. SIR CHARLES BELL, K. H. F. R. S, THE HAND: ITS MECHANISM AND VITAL ENDOWMENTS AS EVINCING DESIGN. PETER MARK ROGET, M. D. Fellow of and Secretary to the Royal Society. ON ANIMAL AND VEGETABLE PHYSIOLOGY. THE REV. WILLIAM BUCKLAND, D. D. F. R. S. Canon of Christ Church, and Professor of Geology in the University of Oxford. ON GEOLOGY AND MINERALOGY. THE REV. WILLIAM KIRBY, M. A. F. R. S. ON THE HISTORY, HABITS, AND INSTINCTS OF ANIMALS. WILLIAM PROUT, M. D. F. R. S. ON CHEMISTRY, METEOROLOGY, AND THE FUNCTION OF DIGESTION. HIS ROYAL HIGHNESS THE DUKE OF SUSSEX, President of the Royal Society, having desired that no unnecessary delay should take place in the publication of the above mentioned treatises, they will appear at short intervals, as they are ready for publication. CONTENTS. [Within the last year or two, several works have been published in this country on subjects more or less closely approaching to that here treated. It may, therefore, be not superfluous to say that the author of the following pages believes that he has not borrowed any of his views or illustrations from recent English writers on Natural Theology.] Page. INTRODUCTION. CHAPTER I. Object of the Present Treatise 13 II. On Laws of Nature 17 III. Mutual Adaptation of Laws of Nature 20 IV. Division of the Subject 23 BOOK I. TERRESTRIAL ADAPTATIONS 25 CHAPTER I. The Length of the Year 28 II. The Length of the Day 37 III. The Mass of the Earth 43 IV. The Magnitude of the Ocean 50 V. The Magnitude of the Atmosphere 51 VI. The Constancy and Variety of Climates 52 VII. The Variety of Organization corresponding to the Variety of Climate 57 VIII. The Constituents of Climate 66 The Laws of Heat with respect to the Earth 67 IX. The Laws of Heat with respect to Water 70 X. The Laws of Heat with respect to Air 81 XI. The Laws of Electricity 91 XII. The Laws of Magnetism 93 XIII. The Properties of Light with regard to Vegetation 94 XIV. Sound 96 XV. The Atmosphere 102 XVI. Light 104 XVII. The Ether 111 XVIII. Recapitulation 113 BOOK II. COSMICAL ARRANGEMENTS 119 CHAPTER I. The Structure of the Solar System 121 II. The Circular Orbits of the Planets round the Sun 123 III. The Stability of the Solar System 127 IV. The Sun in the Centre 134 V. The Satellites 137 VI. The Stability of the Ocean 140 VII. The Nebular Hypothesis 143 VIII. The Existence of a Resisting Medium in the Solar System 150 IX. Mechanical Laws 163 X. The Law of Gravitation 166 XI. The Laws of Motion 178 XII. Friction 183 BOOK III. RELIGIOUS VIEWS 193 CHAPTER I. The Creator of the Physical World is the Governor of the Moral World 195 II. On the Vastness of the Universe 205 III. On Man’s Place in the Universe 212 IV. On the Impression produced by the Contemplation of Laws of Nature; or, on the Conviction that Law implies Mind 223 V. On Inductive Habits; or, on the impression produced on Men’s Minds by discovering Laws of Nature 230 VI. On Deductive Habits; or, on the Impression produced on Men’s Minds by tracing the Consequences of ascertained Laws 243 VII. On Final Causes 257 VIII. On the Physical Agency of the Deity 267 IX. On the Impression produced by considering the Nature and Prospects of Science; or, on the Impossibility of the Progress of our Knowledge ever enabling us to comprehend the Nature of the Deity 273 ON ASTRONOMY AND GENERAL PHYSICS. INTRODUCTION. CHAPTER I. _Object of the Present Treatise._ The examination of the material world brings before us a number of things and relations of things which suggest to most minds the belief of a creating and presiding Intelligence. And this impression, which arises with the most vague and superficial consideration of the objects by which we are surrounded, is, we conceive, confirmed and expanded by a more exact and profound study of external nature. Many works have been written at different times with the view of showing how our knowledge of the elements and their operation, of plants and animals and their construction, may serve to nourish and unfold our idea of a Creator and Governor of the world. But though this is the case, a new work on the same subject may still have its use. Our views of the Creator and Governor of the world, as collected from or combined with our views of the world itself, undergo modifications, as we are led by new discoveries, new generalizations, to regard nature in a new light. The conceptions concerning the Deity, his mode of effecting his purposes, the scheme of his government, which are suggested by one stage of our knowledge of natural objects and operations, may become manifestly imperfect or incongruous, if adhered to and applied at a later period, when our acquaintance with the immediate causes of natural events has been greatly extended. On this account it may be interesting, after such an advance, to show how the views of the creation, preservation, and government of the universe, which natural science opens to us, harmonize with our belief in a Creator, Governor, and Preserver of the world. To do this with respect to certain departments of Natural Philosophy is the object of the following pages; and the author will deem himself fortunate, if he succeeds in removing any of the difficulties and obscurities which prevail in men’s minds, from the want of a clear mutual understanding between the religious and the scientific speculator. It is needless here to remark the necessarily imperfect and scanty character of Natural Religion; for most persons will allow that, however imperfect may be the knowledge of a Supreme Intelligence which we gather from the contemplation of the natural world, it is still of most essential use and value. And our purpose on this occasion is, not to show that Natural Theology is a perfect and satisfactory scheme, but to bring up our Natural Theology to the point of view in which it may be contemplated by the aid of our Natural Philosophy. Now the peculiar point of view which at present belongs to Natural Philosophy, and especially to the departments of it which have been most successfully cultivated, is, that nature, so far as it is an object of scientific research, is a collection of facts governed by _laws_: our knowledge of nature is our knowledge of laws; of laws of operation and connexion, of laws of succession and co-existence, among the various elements and appearances around us. And it must therefore here be our aim to show how this view of the universe falls in with our conception of the Divine Author, by whom we hold the universe to be made and governed. _Nature acts by general laws_; that is, the occurrences of the world in which we find ourselves, result from causes which operate according to fixed and constant rules. The succession of days, and seasons, and years, is produced by the motions of the earth; and these again are governed by the attraction of the sun, a force which acts with undeviating steadiness and regularity. The changes of winds and skies, seemingly so capricious and casual, are produced by the operation of the sun’s heat upon air and moisture, land and sea; and though in this case we cannot trace the particular events to their general causes, as we can trace the motions of the sun and moon, no philosophical mind will doubt the generality and fixity of the rules by which these causes act. The variety of the effects takes place, because the circumstances in different cases vary; and not because the action of material causes leaves anything to chance in the result. And again, though the vital movements which go on in the frame of vegetables and animals depend on agencies still less known, and probably still more complex, than those which rule the weather, each of the powers on which such movements depend has its peculiar laws of action, and these are as universal and as invariable as the law by which a stone falls to the earth when not supported. The world then is governed by general laws; and in order to collect from the world itself a judgment concerning the nature and character of its government, we must consider the import and tendency of such laws, so far as they come under our knowledge. If there be, in the administration of the universe, intelligence and benevolence, superintendence and foresight, grounds for love and hope, such qualities may be expected to appear in the constitution and combination of those fundamental regulations by which the course of nature is brought about, and made to be what it is. If a man were, by some extraordinary event, to find himself in a remote and unknown country, so entirely strange to him that he did not know whether there existed in it any law or government at all; he might in no long time ascertain whether the inhabitants were controlled by any superintending authority; and with a little attention he might determine also whether such authority were exercised with a prudent care for the happiness and well-being of its subjects, or without any regard and fitness to such ends; whether the country were governed by laws at all, and whether the laws were good. And according to the laws which he thus found prevailing, he would judge of the sagacity, and the purposes of the legislative power. By observing the laws of the material universe and their operation, we may hope, in a somewhat similar manner, to be able to direct our judgment concerning the government of the universe: concerning the mode in which the elements are regulated and controlled, their effects combined and balanced. And the general tendency of the results thus produced may discover to us something of the character of the power which has legislated for the material world. We are not to push too far the analogy thus suggested. There is undoubtedly a wide difference between the circumstances of man legislating for man, and God legislating for matter. Still we shall, it will appear, find abundant reason to admire the wisdom and the goodness which have established _the Laws of Nature_, however rigorously we may scrutinize the import of this expression. CHAPTER II. _On Laws of Nature._ When we speak of material nature as being governed by _laws_, it is sufficiently evident that we use the term in a manner somewhat metaphorical. The laws to which man’s attention is primarily directed are _moral_ laws; rules laid down for his actions; rules for the conscious actions of a person; rules which, as a matter of possibility, he may obey or may transgress; the latter event being combined, not with an impossibility, but with a penalty. But the _Laws of Nature_ are something different from this; they are rules for that which _things_ are to do and suffer; and this by no consciousness or will of theirs. They are rules describing the mode in which things _do_ act; they are invariably obeyed; their transgression is not punished, it is excluded. The language of a moral law is, man _shall_ not kill; the language of a Law of Nature is, a stone _will_ fall to the earth. These two kinds of laws direct the actions of persons and of things, by the sort of control of which persons and things are respectively susceptible; so that the metaphor is very simple; but it is proper for us to recollect that it is a metaphor, in order that we may clearly apprehend what is implied in speaking of the Laws of Nature. In this phrase are included all properties of the portions of the material world; all modes of action and rules of causation, according to which they operate on each other. The whole course of the visible universe therefore is but the collective result of such laws; its movements are only the aggregate of _their_ working. All natural occurrences, in the skies and on the earth, in the organic and in the inorganic world, are determined by the relations of the elements and the actions of the forces of which the rules are thus prescribed. The relations and rules by which these occurrences are thus determined necessarily depend on measures of time and space, motion and force; on quantities which are subject to numerical measurement, and capable of being connected by mathematical properties. And thus all things are ordered by number and weight and measure. “God,” as was said by the ancients, “works by geometry:” the legislation of the material universe is necessarily delivered in the language of mathematics; the stars in their courses are regulated by the properties of conic sections, and the winds depend on arithmetical and geometrical progressions of elasticity and pressure. The constitution of the universe, so far as it can be clearly apprehended by our intellect, thus assumes a shape involving an assemblage of mathematical propositions: certain algebraical formulæ, and the knowledge when and how to apply them, constitute the last step of the physical science to which we can attain. The labour and the endowments of ages have been employed in bringing such science into the condition in which it now exists; and an exact and extensive discipline in mathematics, followed by a practical and profound study of the researches of natural philosophers, can alone put any one in possession of the knowledge concerning the course of the material world, which is at present open to man. The general impression, however, which arises from the view thus obtained of the universe, the results which we collect from the most careful scrutiny of its administration, may, we trust, be rendered intelligible without this technical and laborious study, and to do this is our present object. It will be our business to show that the laws which really prevail in nature are, by their _form_, that is, by the nature of the connexion which they establish among the quantities and properties which they regulate, remarkably adapted to the office which is assigned them; and thus offer evidence of selection, design, and goodness, in the power by which they were established. But these characters of the legislation of the universe may also be seen, in many instances, in a manner somewhat different from the selection of the law. The _nature of the connexion_ remaining the same, the quantities which it regulates may also in their _magnitude_ bear marks of selection and purpose. For the law may be the same while the quantities to which it applies are different. The law of the gravity which acts to the earth and to Jupiter, is the same; but the intensity of the force at the surfaces of the two planets is different. The law which regulates the density of the air at any point, with reference to the height from the earth’s surface, would be the same, if the atmosphere were ten times as large, or only one-tenth as large as it is; if the barometer at the earth’s surface stood at three inches only, or if it showed a pressure of thirty feet of mercury. Now this being understood, the adaptation of a law to its purpose, or to other laws, may appear in two ways:--either in the form of the law, or in the amount of the magnitudes which it regulates, which are sometimes called _arbitrary magnitudes_. If the attraction of the sun upon the planets did not vary inversely as the square of the distance, the _form_ of the law of gravitation would be changed; if this attraction were, at the earth’s orbit, of a different _value_ from its present one, the arbitrary magnitude would be changed; and it will appear, in a subsequent part of this work, that either change would, so far as we can trace its consequences, be detrimental. The form of the law determines in what manner the facts shall take place; the arbitrary magnitude determines how fast, how far, how soon; the one gives a model, the other a measure of the phenomenon; the one draws the plan, the other gives the scale on which it is to be executed; the one gives the rule, the other the rate. If either were wrongly taken, the result would be wrong too. CHAPTER III. _Mutual Adaptation in the Laws of Nature._ To ascertain such laws of nature as we have been describing, is the peculiar business of science. It is only with regard to a very small portion of the appearances of the universe, that science, in any strict application of the term, exists. In very few departments of research have men been able to trace a multitude of known facts to causes which appear to be the ultimate material causes, or to discern the laws which seem to be the most general laws. Yet, in one or two instances, they have done this, or something approaching to this; and most especially in the instance of that part of nature, which it is the object of this treatise more peculiarly to consider. The apparent motions of the sun, moon, and stars have been more completely reduced to their causes and laws than any other class of phenomena. Astronomy, the science which treats of these, is already a wonderful example of the degree of such knowledge which man may attain. The forms of its most important laws may be conceived to be certainly known; and hundreds of observers in all parts of the world are daily employed in determining, with additional accuracy, the arbitrary magnitudes which these laws involve. The inquiries in which the mutual effects of heat, moisture, air, and the like elements are treated of, including, among other subjects, all that we know of the causes of the weather (meteorology) is a far more imperfect science than astronomy. Yet, with regard to these agents, a great number of laws of nature have been discovered, though, undoubtedly, a far greater number remain still unknown. So far, therefore, as our knowledge goes, astronomy and meteorology are parts of natural philosophy in which we may study the order of nature with such views as we have suggested; in which we may hope to make out the adaptations and aims which exist in the laws of nature; and thus to obtain some light on the tendency of this part of the legislation of the universe, and on the character and disposition of the Legislator. The number and variety of the laws which we find established in the universe is so great, that it would be idle to endeavour to enumerate them. In their operation they are combined and intermixed in incalculable and endless perplexity, influencing and modifying each other’s effects in every direction. If we attempt to comprehend at once the whole of this complex system, we find ourselves utterly baffled and overwhelmed by its extent and multiplicity. Yet, in so far as we consider the bearing of one part upon another, we receive an impression of adaptation, of mutual fitness, of conspiring means, of preparation and completion, of purpose and provision. This impression is suggested by the contemplation of every part of nature; but the grounds of it, from the very circumstances of the case, cannot be conveyed in a few words. It can only be fully educed by leading the reader through several views and details, and must grow out of the combined influence of these on a sober and reflecting frame of mind. However strong and solemn be the conviction which may be derived from a contemplation of nature, concerning the existence, the power, the wisdom, the goodness of our Divine Governor, we cannot expect that this conviction, as resulting from the extremely complex spectacle of the material world, should be capable of being irresistibly conveyed by a few steps of reasoning, like the conclusion of a geometrical proposition, or the result of an arithmetical calculation. We shall, therefore, endeavour to point out cases and circumstances in which the different parts of the universe exhibit this mutual adaptation, and thus to bring before the mind of the reader the evidence of wisdom and providence, which the external world affords. When we have illustrated the correspondencies which exist in every province of nature, between the qualities of brute matter and the constitution of living things, between the tendency to derangement and the conservative influences by which such a tendency is counteracted, between the office of the minutest speck and of the most general laws; it will, we trust, be difficult or impossible to exclude from our conception of this wonderful system, the idea of a harmonizing, a preserving, a contriving, an intending Mind; of a Wisdom, Power, and Goodness far exceeding the limits of our thoughts. CHAPTER IV. _Division of the Subject._ In making a survey of the universe, for the purpose of pointing out such correspondencies and adaptations as we have mentioned, we shall suppose the general leading facts of the course of nature to be known, and the explanations of their causes now generally established among astronomers and natural philosophers to be conceded. We shall assume therefore that the earth is a solid globe of ascertained magnitude, which travels round the sun, in an orbit nearly circular, in a period of about three hundred and sixty-five days and a quarter, and in the mean time revolves, in an inclined position, upon its own axis in about twenty-four hours, thus producing the succession of appearances and effects which constitute seasons and climates, day and night;--that this globe has its surface furrowed and ridged with various inequalities, the waters of the ocean occupying the depressed parts:--that it is surrounded by an atmosphere, or spherical covering of air; and that various other physical agents, moisture, electricity, magnetism, light, operate at the surface of the earth, according to their peculiar laws. This surface is, as we know, clothed with a covering of plants, and inhabited by the various tribes of animals, with all their variety of sensations, wants, and enjoyments. The relations and connexions of the larger portions of the world, the sun, the planets, and the stars, the _cosmical_ arrangements of the system, as they are sometimes called, determine the course of events among these bodies; and the more remarkable features of these arrangements are therefore some of the subjects for our consideration. These cosmical arrangements, in their consequences, affect also the physical agencies which are at work at the surface of the earth, and hence come in contact with _terrestrial_ occurrences. They thus influence the functions of plants and animals. The circumstances in the cosmical system of the universe, and in the organic system of the earth, which have thus a bearing on each other, form another of the subjects of which we shall treat. The former class of considerations attends principally to the stability and other apparent perfections of the solar system; the latter to the well-being of the system of organic life by which the earth is occupied. The two portions of the subject may be treated as Cosmical Arrangements and Terrestrial Adaptations. We shall begin with the latter class of adaptations, because in treating of these the facts are more familiar and tangible, and the reasonings less abstract and technical, than in the other division of the subject. Moreover, in this case men have no difficulty in recognizing as desirable the end which is answered by such adaptations, and they therefore the more readily consider it _as an end_. The nourishment, the enjoyment, the diffusion of living things, are willingly acknowledged to be a suitable object for contrivance; the simplicity, the permanence, of an inert mechanical combination might not so readily be allowed to be a manifestly worthy aim of a Creating Wisdom. The former branch of our argument may therefore be best suited to introduce to us the Deity as the institutor of Laws of Nature, though the latter may afterwards give us a wider view and a clearer insight into one province of his legislation. BOOK I. TERRESTRIAL ADAPTATIONS. We proceed in this book to point out relations which subsist between the laws of the inorganic world, that is, the general facts of astronomy and meteorology; and the laws which prevail in the organic world, the properties of plants and animals. With regard to the first kind of laws, they are in the highest degree various and unlike each other. The intensity and activity of natural influences follow in different cases the most different rules. In some instances they are _periodical_, increasing and diminishing alternately, in a perpetual succession of equal intervals of time. This is the case with the heat at the earth’s surface, which has a period of a year; with the light, which has a period of a day. Other qualities are _constant_, thus the force of gravity at the same place is always the same. In some cases, a very simple cause produces very complicated effects; thus the globular form of the earth, and the inclination of its axis during its annual motion, give rise to all the variety of climates. In other cases a very complex and variable system of causes produces effects comparatively steady and uniform; thus solar and terrestrial heat, air, moisture, and probably many other apparently conflicting agents, join to produce our weather, which never deviates very far from a certain average standard. Now a general fact, which we shall endeavour to exemplify in the following chapters, is this:--That those properties of plants and animals which have reference to agencies of a periodical character, have also by their nature a periodical mode of working; while those properties which refer to agencies of constant intensity, are adjusted to this constant intensity: and again, there are peculiarities in the nature of organized beings which have reference to a variety in the conditions of the external world, as, for instance, the difference of the organized population of different regions: and there are other peculiarities which have a reference to the constancy of the average of such conditions, and the limited range of the deviations from that average; as for example, that constitution by which each plant and animal is fitted to exist and prosper in its usual place in the world. And not only is there this general agreement between the nature of the laws which govern the organic and inorganic world, but also there is a coincidence between the _arbitrary magnitudes_ which such laws involve on the one hand and on the other. Plants and animals have, in their construction, certain periodical functions, which have a reference to alternations of heat and cold; the length of the period which belongs to these functions by their construction, appears to be that of the period which belongs to the actual alternations of heat and cold, namely, a year. Plants and animals have again in their construction certain other periodical functions, which have a reference to alternations of light and darkness; the length of the period of such functions appears to coincide with the natural day. In like manner the other arbitrary magnitudes which enter into the laws of gravity, of the effects of air and moisture, and of other causes of permanence, and of change, by which the influences of the elements operate, are the same arbitrary magnitudes to which the members of the organic world are adapted by the various peculiarities of their construction. The illustration of this view will be pursued in the succeeding chapters; and when the coincidence here spoken of is distinctly brought before the reader, it will, we trust, be found to convey the conviction of a wise and benevolent design, which has been exercised in producing such an agreement between the internal constitution and the external circumstances of organized beings. We shall adduce cases where there is an apparent relation between the course of operation of the elements and the course of vital functions; between some fixed measure of time or space, traced in the lifeless and in the living world; where creatures are constructed on a certain plan, or a certain scale, and this plan or this scale is exactly the single one which is suited to their place on the earth; where it was necessary for the Creator (if we may use such a mode of speaking) _to take account_ of the weight of the earth, or the density of the air, or the measure of the ocean, and where these quantities are rightly taken account of in the arrangements of creation. In such cases we conceive that we trace a Creator, who, in producing one part of his work, was not forgetful or careless of another part; who did not cast his living creatures into the world to prosper or perish as they might find it suited to them or not; but fitted together, with the nicest skill, the world and the constitution which he gave to its inhabitants; so fashioning it and them, that light and darkness, sun and air, moist and dry, should become their ministers and benefactors, the unwearied and unfailing causes of their well-being. We have spoken of the mutual adaptation of the organic and the inorganic world. If we were to conceive the contrivance of the world as taking place in an order of time in the contriving mind, we might also have to conceive this adaptation as taking place in one of two ways: we might either suppose the laws of inert nature to be accommodated to the foreseen wants of living things, or the organization of life to be accommodated to the previously established laws of nature. But we are not forced upon any such mode of conception, or upon any decision between such suppositions: since, for the purpose of our argument, the consequence of either view is the same. There is an adaptation somewhere or other, on either supposition. There is account taken of one part of the system in framing the other: and the mind which took such account can be no other than that of the Intelligent Author of the universe. When indeed we come to see the vast number, the variety, the extent, the interweaving, the reconciling of such adaptations, we shall readily allow, that all things are so moulded upon and locked into each other, connected by such subtilty and profundity of design, that we may well abandon the idle attempt to trace the _order_ of thought in the mind of the Supreme Ordainer. CHAPTER I. _The Length of the Year._ A year is the most important and obvious of the periods which occur in the organic, and especially in the vegetable world. In this interval of time the cycle of most of the external influences which operate upon plants is completed. There is also in plants a cycle of internal functions, corresponding to this succession of external causes. The length of either of these periods might have been different from what it is, according to any grounds of necessity which we can perceive. But a certain length is selected in both instances, and in both instances the same. The length of the year is so determined as to be adapted to the constitution of most vegetables; or the construction of vegetables is so adjusted as to be suited to the length which the year really has, and unsuited to a duration longer or shorter by any considerable portion. The vegetable clock-work is so set as to go for a year. The length of the year or interval of recurrence of the seasons is determined by the time which the earth employs in performing its revolution round the sun: and we can very easily conceive the solar system so adjusted that the year should be longer or shorter than it actually is. We can imagine the earth to revolve round the sun at a distance greater or less than that which it at present has, all the forces of the system remaining unaltered. If the earth were removed towards the centre by about one-eighth of its distance, the year would be diminished by about a month; and in the same manner it would be increased by a month on increasing the distance by one-eighth. We can suppose the earth at a distance of eighty-four or a hundred and eight millions of miles, just as easily as at its present distance of ninety-six millions: we can suppose the earth with its present stock of animals and vegetables placed where Mars or where Venus is, and revolving in an orbit like one of theirs: on the former supposition our year would become twenty-three, on the latter seven of our present months. Or we can conceive the present distances of the parts of the system to continue what they are, and the size, or the density of the central mass, the sun, to be increased or diminished in any proportion; and in this way the time of the earth’s revolution might have been increased or diminished in any degree; a greater velocity, and consequently a diminished period, being requisite in order to balance an augmented central attraction. In any of these ways the length of the earth’s natural year might have been different from what it now is: in the last way without any necessary alteration, so far as we can see, of temperature. Now, if any change of this kind were to take place, the working of the botanical world would be thrown into utter disorder, the functions of plants would be entirely deranged, and the whole vegetable kingdom involved in instant decay and rapid extinction. That this would be the case, may be collected from innumerable indications. Most of our fruit trees, for example, require the year to be of its present length. If the summer and the autumn were much shorter, the fruit could not ripen; if these seasons were much longer, the tree would put forth a fresh suit of blossoms, to be cut down by the winter. Or if the year were twice its present length, a second crop of fruit would probably not be matured, for want, among other things, of an intermediate season of rest and consolidation, such as the winter is. Our forest trees in like manner appear to need all the seasons of our present year for their perfection; the spring, summer, and autumn, for the developement of their leaves and consequent formation of their _proper juice_, and of wood from this; and the winter for the hardening and solidifying the substance thus formed. Most plants, indeed, have some peculiar function adapted to each period of the year, that is of the now existing year. The sap ascends with extraordinary copiousness at two seasons, in the spring and in the autumn, especially the former. The opening of the leaves and the opening of the flowers of the same plants are so constant to their times, (their _appointed_ times, as we are naturally led to call them,) that such occurrences might be taken as indications of the times of the year. It has been proposed in this way to select a series of botanical facts which should form a calendar; and this has been termed a _calendar of Flora_. Thus, if we consider the time of putting forth leaves,[1] the honeysuckle protrudes them in the month of January; the gooseberry, currant, and elder in the end of February, or beginning of March; the willow, elm, and lime-tree in April; the oak and ash, which are always the latest among trees, in the beginning or towards the middle of May. In the same manner the flowering has its regular time: the mezereon and snowdrop push forth their flowers in February; the primrose in the month of March; the cowslip in April; the great mass of plants in May and June; many in July, August, and September; some, not till the month of October, as the meadow saffron; and some not till the approach and arrival of winter, as the laurustinus and arbutus. The fact which we have here to notice, is the recurrence of these stages in the developement of plants, at intervals precisely or very nearly of twelve months. Undoubtedly, this result is in part occasioned by the action of external stimulants upon the plant, especially heat, and by the recurrence of the intensity of such agents. Accordingly, there are slight differences in the times of such occurrences, according to the backwardness or forwardness of the season, and according as the climate is genial or otherwise. Gardeners use artifices which will, to a certain extent, accelerate or retard the time of developement of a plant. But there are various circumstances which show that this recurrence of the same events and equal intervals is not entirely owing to external causes, and that it depends also upon something in the internal structure of vegetables. Alpine plants do not wait for the stimulus of the sun’s heat, but exert such a struggle to blossom, that their flowers are seen among the yet unmelted snow. And this is still more remarkable in the naturalization of plants from one hemisphere to the other. When we transplant our fruit trees to the temperate regions south of the equator, they continue for some years to flourish at the period which corresponds to our spring. The reverse of this obtains, with certain trees of the southern hemisphere. Plants from the Cape of Good Hope, and from Australia, countries whose summer is simultaneous with our winter, exhibit their flowers in the coldest part of the year, as the heaths. This view of the subject agrees with that maintained by the best botanical writers. Thus Decandolle observes that after making allowance for all meteorological causes, which determine the epoch of flowering, we must reckon as another cause the peculiar nature of each species. The flowering once determined, appears to be subject to a law of _periodicity_ and habit.[2] It appears then that the functions of plants have by their nature a periodical character; and the length of the period thus belonging to vegetables is a result of their organization. Warmth and light, soil and moisture, may in some degree modify, and hasten or retard the stages of this period; but when the constraint is removed the natural period is again resumed. Such stimulants as we have mentioned are not the _causes_ of this periodicity. They do not produce the varied functions of the plant, and could not occasion their performance at regular intervals, except the plant possessed a suitable construction. They could not alter the length of the cycle of vegetable functions, except within certain very narrow limits. The processes of the rising of the sap, of the formation of proper juices, of the unfolding of leaves, the opening of flowers, the fecundation of the fruit, the ripening of the seed, its proper deposition in order for the reproduction of a new plant;--all these operations require a certain portion of time, and could not be compressed into a space less than a year, or at least could not be abbreviated in any very great degree. And on the other hand, if the winter were greatly longer than it now is, many seeds would not germinate at the return of spring. Seeds which have been kept too long require stimulants to make them fertile. If therefore the duration of the seasons were much to change, the processes of vegetable life would be interrupted, deranged, distempered. What, for instance, would become of our calendar of Flora, if the year were lengthened or shortened by six months? Some of the dates would never arrive in the one case, and the vegetable processes which mark them would be superseded; some seasons would be without dates in the other case, and these periods would be employed in a way harmful to the plants, and no doubt speedily destructive. We should have not only _a year of confusion_, but, if it were repeated and continued, a year of death. But in the existing state of things, the duration of the earth’s revolution round the sun, and the duration of the revolution of the vegetable functions of most plants are equal. These two periods are _adjusted_ to each other. The stimulants which the elements apply come at such intervals and continue for such times, that the plant is supported in health and vigour, and enabled to reproduce its kind. Just such a portion of time is measured out for the vegetable powers to execute their task, as enables them to do so in the best manner. Now such an adjustment must surely be accepted as a proof of design, exercised in the formation of the world. Why should the solar year be so long and no longer? or, this being of such a length, why should the vegetable cycle be exactly of the same length? Can this be chance? And this occurs, it is to be observed, not in one, or in a few species of plants, but in thousands. Take a small portion only of known species, as the most obviously endowed with this adjustment, and say ten thousand. How should all these organized bodies be constructed for the same period of a year? How should all these machines be wound up so as to go for the same time? Even allowing that they could bear a year of a month longer or shorter, how do they all come within such limits? No chance could produce such a result. And if not by chance, how otherwise could such a coincidence occur, than by an intentional adjustment of these two things to one another? by a selection of such an organization in plants, as would fit them to the earth on which they were to grow; by an adaptation of construction to conditions; of the scale of the construction to the scale of the conditions. It cannot be accepted as an explanation of this fact in the economy of plants, that it is necessary to their existence; that no plants could possibly have subsisted, and come down to us, except those which were thus suited to their place on earth. This is true; but this does not at all remove the necessity of recurring to design as the origin of the construction by which the existence and continuance of plants is made possible. A watch could not go, except there were the most exact adjustment in the forms and positions of its wheels; yet no one would accept it as an explanation of the origin of such forms and positions, that the watch would not go if these were other than they are. If the objector were to suppose that plants were originally fitted to years of various lengths, and that such only have survived to the present time, as had a cycle of a length equal to our present year, or one which could be accommodated to it; we should reply, that the assumption is too gratuitous and extravagant to require much consideration; but that, moreover, it does not remove the difficulty. How came the functions of plants to be _periodical_ at all? Here is, in the first instance, an agreement in the form of the laws that prevail in the organic and in the inorganic world, which appears to us a clear evidence of design in their Author. And the same kind of reply might be made to any similar objection to our argument. Any supposition that the universe has gradually approximated to that state of harmony among the operations of its different parts, of which we have one instance in the coincidence now under consideration, would make it necessary for the objector to assume a previous state of things preparatory to this perfect correspondence. And in this preparatory condition we should still be able to trace the rudiments of that harmony, for which it was proposed to account: so that even the most unbounded license of hypothesis would not enable the opponent to obliterate the traces of an intentional adaptation of one part of nature to another. Nor would it at all affect the argument, if these periodical occurrences could be traced to some proximate cause: if for instance it could be shown, that the budding or flowering of plants is brought about at particular intervals, by the nutriment accumulated in their vessels during the preceding months. For the question would still remain, how their functions were so adjusted, that the accumulation of the nutriment necessary for budding and flowering, together with the operation itself, comes to occupy exactly a year, instead of a month only, or ten years. There must be in their structure some reference to time: how did such a reference occur? how was it i determined to the particular time of the earth’s revolution round the sun? This could be no otherwise, as we conceive, than by design and appointment. We are left therefore with this manifest adjustment before us, of two parts of the universe, at first sight so remote; the dimensions of the solar system and the powers of vegetable life. These two things are so related, that one has been made to fit the other. The relation is as clear as that of a watch to a sundial. If a person were to compare the watch with the dial, hour after hour, and day after day, it would be impossible for him not to believe that the watch had been _contrived_ to accommodate itself to the solar day. We have at least ten thousand kinds of vegetable watches of the most various forms, which are all accommodated to the solar year; and the evidence of contrivance seems to be no more capable of being eluded in this case than in the other. The same kind of argument might be applied to the animal creation. The pairing, nesting, hatching, fledging, and flight of birds, for instance, occupy each its peculiar time of the year; and, together with a proper period of rest, fill up the twelve months. The transformations of most insects have a similar reference to the seasons, their progress and duration. “In every species,” (except man,) says a writer[3] on animals, “there is a peculiar period of the year in which the reproductive system exercises its energies. And the season of love and the period of gestation are so arranged that the young ones are produced at the time wherein the conditions of temperature are most suited to the commencement of life.” It is not our business here to consider the details of such provisions, beautiful and striking as they are. But the prevalence of the great law of periodicity in the vital functions of organized beings will be allowed to have a claim to be considered in its reference to astronomy, when it is seen that their periodical constitution derives its use from the periodical nature of the motions of the planets round the sun; and that the duration of such cycles in the existence of plants and animals has a reference to the arbitrary elements of the solar system: a reference which, we maintain, is inexplicable and unintelligible, except by admitting into our conceptions; an Intelligent Author, alike of the organic and inorganic universe. CHAPTER II. _The Length of the Day._ We shall now consider another astronomical element, the time of the revolution of the earth on its axis; and we shall find here also that the structure of organized bodies are suited to this element;--that the cosmical and physiological arrangements are adapted to each other. We can very easily conceive the earth to revolve on her axis faster or slower than she does, and thus the days to be longer or shorter than they are, without supposing any other change to take place. There is no apparent reason why this globe should turn on its axis just three hundred and sixty-six times while it describes its orbit round the sun. The revolutions of the other planets, so far as we know them, do not appear to follow any rule by which they are connected with the distance from the sun. Mercury, Venus, and Mars have days nearly the length of ours. Jupiter and Saturn revolve in about ten hours each. For any thing we can discover, the earth might have revolved in this or any other smaller period; or we might have had, without mechanical inconvenience, much longer days than we have. But the terrestrial day, and consequently the length of the cycle of light and darkness, being what it is, we find various parts of the constitution both of animals and vegetables, which have a periodical character in their functions, corresponding to the diurnal succession of external conditions; and we find that the length of the period, as it exists in their constitution, coincides with the length of the natural day. The alternation of processes which takes place in plants by day and by night is less obvious, and less obviously essential to their well-being, than the annual series of changes. But there are abundance of facts which serve to show that such an alternation is part of the vegetable economy. In the same manner in which Linnæus proposed a Calendar of Flora, he also proposed a _Dial of Flora_, or Flower-Clock; and this was to consist, as will readily be supposed, of plants, which mark certain hours of the day, by opening and shutting their flowers. Thus the day-lily (_hemerocallis fulva_) opens at five in the morning; the _leontodon taraxacum_, or common dandelion, at five or six; the _hieracium latifolium_ (hawkweed), at seven; the _hieracium pilosella_, at eight; the _calendula arvensis_, or marigold, at nine; the _mesembryanthemum neapolitanum_, at ten or eleven; and the closing of these and other flowers in the latter part of the day offers a similar system of hour marks. Some of these plants are thus expanded in consequence of the stimulating action of the light and heat of the day, as appears by their changing their time, when these influences are changed; but others appear to be constant to the same hours, and independent of the impulse of such external circumstances. Other flowers by their opening and shutting prognosticate the weather. Plants of the latter kind are called by Linnæus _meteoric_ flowers, as being regulated by atmospheric causes: those which change their hour of opening and shutting with the length of the day, he terms _tropical_; and the hours which they measure are, he observes, like Turkish hours, of varying length at different seasons. But there are other plants which he terms _equinoctial_; their vegetable days, like the days of the equator, being always of equal length; and these open, and generally close, at a fixed and positive hour of the day. Such plants clearly prove that the periodical character, and the period of the motions above described, do not depend altogether on external circumstances. Some curious experiments on this subject were made by Decandolle. He kept certain plants in two cellars, one warmed by a stove and dark, the other lighted by lamps. On some of the plants the artificial light appeared to have no influence, (_convolvulus arvensis_, _convolvulus cneorum_, _silene fruticosa_) and they still followed the clock hours in their opening and closing. The night-blowing plants appeared somewhat disturbed, both by perpetual light and perpetual darkness. In either condition they accelerated their _going_ so much, that in three days they had gained half a day, and thus exchanged night for day as their time of opening. Other flowers _went slower_ in the artificial light (_convolvulus purpureus_.) In like manner those plants which fold and unfold their leaves were variously affected by this mode of treatment. The _oxalis stricta_ and _oxalis incarnata_ kept their habits, without regarding either artificial light or heat. The _mimosa leucocephala_ folded and unfolded at the usual times, whether in light or in darkness, but the folding up was not so complete as in the open air. The _mimosa pudica_ (sensitive plant,) kept in darkness during the day time, and illuminated during the night, had in three days accommodated herself to the artificial state, opening in the evening, and closing in the morning; restored to the open air, she recovered her usual habits. Tropical plants in general, as is remarked by our gardeners, suffer from the length of our summer daylight; and it has been found necessary to shade them during a certain part of the day. It is clear from these facts, that there is a diurnal period belonging to the constitution of vegetables; though the succession of functions depends in part on external stimulants, as light and heat, their periodical character is a result of the structure of the plant; and this structure is such, that the length of the period, under the common influences to which plants are exposed, coincides with the astronomical day. The power of accommodation which vegetables possess in this respect, is far from being such as either to leave the existence of this periodical constitution doubtful, or to entitle us to suppose that the day might be considerably lengthened or shortened without injury to the vegetable kingdom. Here then we have an adaptation between the structure of plants, and the periodical order of light and darkness which arises from the earth’s rotation; and the arbitrary quantity, the length of the cycle of the physiological and of the astronomical fact, is the same. Can this have occurred any otherwise than by an intentional adjustment? Any supposition that the astronomical cycle has occasioned the physiological one, that the structure of plants has been brought to be what it is by the action of external causes, or that such plants as could not accommodate themselves to the existing day have perished, would be not only an arbitrary and baseless assumption, but moreover useless for the purposes of explanation which it professes, as we have noticed of a similar supposition with respect to the annual cycle. How came plants to have periodicity at all in those functions which have a relation to light and darkness? This part of their constitution was suited to organized things which were to flourish on the earth, and it is accordingly bestowed on them; it was necessary for this end that the period should be of a certain length; it is of that length and no other. Surely this looks like intentional provision. Animals also have a period in their functions and habits; as in the habits of waking, sleeping, eating, &c. and their well-being appears to depend on the coincidence of this period with the length of the natural day. We see that in the day, as it now is, all animals find seasons for taking food and repose, which agree perfectly with their health and comfort. Some animals feed during the day, as nearly all the ruminating animals and land birds; others feed only in the twilight, as bats and owls, and are called _crepuscular;_ while many beasts of prey, aquatic birds, and others, take their food during the night. Those animals which are nocturnal feeders are diurnal sleepers, while those which are crepuscular, sleep partly in the night and partly in the day; but in all, the complete period of these functions is twenty-four hours. Man, in like manner, in all nations and ages, takes his principal rest once in twenty-four hours; and the regularity of this practice seems most suitable to his health, though the duration of the time allotted to repose is extremely different in different cases. So far as we can judge, this period is of a length beneficial to the human frame, independently of the effect of external agents. In the voyages recently made into high northern latitudes, where the sun did not rise for three months, the crews of the ships were made to adhere, with the utmost punctuality, to the habit of retiring to rest at nine, and rising a quarter before six; and they enjoyed, under circumstances apparently the most trying, a state of salubrity quite remarkable. This shows, that according to the common constitution of such men, the cycle of twenty-four hours is very commodious, though not imposed on them by external circumstances. The hours of food and repose are capable of such wide modifications in animals, and above all in man, by the influence of external stimulants and internal emotions, that it is not easy to distinguish what portion of the tendency to such alternations depends on original constitution. Yet no one can doubt that the inclination to food and sleep is periodical, or can maintain, with any plausibility, that the period may be lengthened or shortened without limit. We may be tolerably certain that a constantly recurring period of forty-eight hours would be too long for one day of employment and one period of sleep, with our present faculties; and all, whose bodies and minds are tolerably active, will probably agree that, independently of habit, a perpetual alternation of eight hours up and four in bed would employ the human powers less advantageously and agreeably than an alternation of sixteen and eight. A creature which could employ the full energies of his body and mind uninterruptedly for nine months, and then take a single sleep of three months, would not be a man. When, therefore, we have subtracted from the daily cycle of the employments of men and animals, that which is to be set down to the account of habits acquired, and that which is occasioned by extraneous causes, there still remains a periodical character; and a period of a certain length, which coincides with, or at any rate easily accommodates itself to, the duration of the earth’s revolution. The physiological analysis of this part of our constitution is not necessary for our purpose. The succession of exertion and repose in the muscular system, of excited and dormant sensibility in the nervous, appear to be fundamentally connected with the muscular and nervous powers, whatever the nature of these may be. The necessity of these alternations is one of the measures of the intensity of those vital energies; and it would seem that we cannot, without assuming the human powers to be altered, suppose the intervals of tranquillity which they require to be much changed. This view agrees with the opinion of some of the most eminent physiologists. Thus Cabanis[4] notices the periodical and isochronous character of the desire of sleep, as well as of other appetites. He states also that sleep is more easy and more salutary, in proportion as we go to rest and rise every day at the same hours; and observes that this periodicity seems to have a reference to the motions of the solar system. Now how should such a reference be at first established in the constitution of man, animals, and plants, and transmitted from one generation of them to another? If we suppose a wise and benevolent Creator, by whom all the parts of nature were fitted to their uses and to each other, this is what we might expect and can understand. On any other supposition such a fact appears altogether incredible and inconceivable. CHAPTER III. _The Mass of the Earth._ We shall now consider the adaptation which may, as we conceive, be traced in the amount of some of the quantities which determine the course of events in the organic world; and especially in the amount of the _forces_ which are in action. The life of vegetables and animals implies a constant motion of their fluid parts, and this motion must be produced by forces which urge or draw the particles of the fluids. The positions of the parts of vegetables are also the result of the flexibility and elasticity of their substance; the voluntary motions of animals are produced by the tension of the muscles. But in all those cases, the effect really produced depends upon the force of gravity also; and in order that the motions and positions may be such as answer their purpose, the forces which produce them must have a due proportion to the force of gravity. In human works, if, for instance, we have a fluid to raise, or a weight to move, some calculation is requisite, in order to determine the power which we must use, relatively to the work which is to be done: we have a mechanical problem to solve, in order that we may adjust the one to the other. And the same adjustment, the same result of a comparison of quantities, manifests itself in the relation which the forces of the organic world bear to the force of gravity. The force of gravity might, so far as we can judge, have been different from what it now is. It depends upon the mass of the earth; and this mass is one of the elements of the solar system, which is not determined by any cosmical necessity of which we are aware. The masses of the several planets are very different, and do not appear to follow any determinate rule, except that upon the whole those nearer to the sun appear to be smaller, and those nearer the outskirts of the system to be larger. We cannot see any thing which would have prevented either the size or the density of the earth from being different, to a very great extent, from what they are. Now, it will be very obvious that if the intensity of gravity were to be much increased, or much diminished, if every object were to become twice as heavy or only half as heavy as it now is, all the forces, both of involuntary and voluntary motion which produce the present orderly and suitable results by being properly proportioned to the resistance which they experience, would be thrown off their balance; they would produce motions too quick or too slow, wrong positions, jerks and stops, instead of steady, well conducted movements. The universe would be like a machine ill regulated; every thing would go wrong; repeated collisions and a rapid disorganization must be the consequence. We will, however, attempt to illustrate one or two of the cases in which this would take place, by pointing out forces which act in the organic world, and which are adjusted to the force of gravity. 1. The first instance we shall take, is the force manifested by the ascent of the sap in vegetables. It appears by a multitude of indisputable experiments, (among the rest, those of Hales, Mirbel, and Dutrochet,) that all plants imbibe moisture by their roots, and _pump it up_, by some internal force, into every part of their frame, distributing it into every leaf. It will be easily conceived that this operation must require a very considerable mechanical force; for the fluid must be sustained as if it were a single column reaching to the top of the tree. The division into minute parts and distribution through small vessels does not at all diminish the total force requisite to raise it. If, for instance, the tree be thirty-three feet high, the pressure must be fifteen pounds upon every square inch in the section of the vessels of the bottom in order merely to support the sap. And it is not only supported, but propelled upwards with great force, so as to supply the constant evaporation of the leaves. The pumping power of the tree must, therefore, be very considerable. That this power is great, has been confirmed by various curious experiments, especially by those of Hales. He measured the force with which the stems and branches of trees draw the fluid from below, and push it upwards. He found, for instance, that a vine in the _bleeding_ season could push up its sap in a glass tube to the height of twenty-one feet above the stump of an amputated branch. The force which produces this effect is part of the economy of the vegetable world; and it is clear that the due operation of the force depends upon its being rightly proportioned to the force of gravity. The weight of the fluid must be counterbalanced, and an excess of force must exist to produce the motion upwards. In the common course of vegetable life, the rate of ascent of the sap is regulated, on the one hand, by the upward pressure of the vegetable power, and on the other, by the amount of the gravity of the fluid, along with the other resistances, which are to be overcome. If, therefore, we suppose gravity to increase, the rapidity of this vegetable circulation will diminish, and the rate at which this function proceeds, will not correspond either to the course of the seasons, or the other physiological processes with which this has to co-operate. We might easily conceive such an increase of gravity as would stop the vital movements of the plant in a very short time. In like manner, a diminution of the gravity of the vegetable juices would accelerate the rising of the sap, and would, probably, hurry and overload the leaves and other organs, so as to interfere with their due operation. Some injurious change, at least, would take place. Here, then, we have the forces of the minutest parts of vegetables adjusted to the magnitude of the whole mass of the earth on which they exist. There is no apparent connexion between the quantity of matter of the earth, and the force of imbibition of the roots of a vine, or the force of propulsion of the vessels of its branches. Yet, these things have such a proportion as the well being of the vine requires. How is this to be accounted for, but by supposing that the circumstances under which the vine was to grow, were attended to in devising its structure? We have not here pretended to decide whether this force of propulsion of vegetables is mechanical or not, because the argument is the same for our purpose on either supposition. Some very curious experiments have recently been made, (by M. Dutrochet,) which are supposed to show that the force is mechanical; that when two different fluids are separated by a thin membrane, a force which M. Dutrochet calls _endosmose_ urges one fluid through the membrane: and that the roots of plants are provided with small vesicles which act the part of such a membrane. M. Poisson has further attempted to show that this force of _endosmose_ may be considered as a particular modification of capillary action. If these views be true, we have here two mechanical forces, capillary action and gravity, which are adjusted to each other in the manner precisely suited to the welfare of vegetables. 2. As another instance of adaptation between the force of gravity and forces which exist in the vegetable world, we may take the positions of flowers. Some flowers grow with the hollow of their cup upwards: others “hang the pensive head,” and turn the opening downwards. Now of these “nodding flowers,” as Linnæus calls them, he observes that they are such as have their pistil longer than the stamens; and, in consequence of this position, the dust from the anthers which are at the ends of the stamens can fall upon the stigma or extremity of the pistil; which process is requisite for making the flower fertile. He gives as instances the flowers _campanula_, _leucoium_, _galanthus_, _fritillaria_. Other botanists have remarked that the position changes at different periods of the flower’s progress. The pistil of the Euphorbia (which is a little globe or germen on a slender stalk) grows upright at first, and is taller than the stamens: at the period suited to its fecundation, the stalk bends under the weight of the ball at its extremity, so as to depress the germen below the stamens; after this it again becomes erect, the globe being now a fruit filled with fertile seeds. The positions in all these cases depend upon the length and flexibility of the stalk which supports the flower, or in the case of the Euphorbia, the germen. It is clear that a very slight alteration in the force of gravity, or in the stiffness of the stalk, would entirely alter the position of the flower cup, and thus make the continuation of the species impossible. We have therefore here a little mechanical contrivance, which would have been frustrated if the proper intensity of gravity had not been assumed in the reckoning. An earth greater or smaller, denser or rarer than the one on which we live, would require a change in the structure and strength of the footstalks of all the little flowers that hang their heads under our hedges. There is something curious in thus considering the whole mass of the earth from pole to pole, and from circumference to centre, as employed in keeping a snowdrop in the position most suited to the promotion of its vegetable health. It would be easy to mention many other parts of the economy of vegetable life, which depend for their use on their adaptation to the force of gravity. Such are the forces and conditions which determine the positions of leaves and of branches. Such again those parts of the vegetable constitution which have reference to the pressure of the atmosphere; for differences in this pressure appear to exercise a powerful influence on the functions of plants, and to require differences of structure. But we pass over these considerations. The slightest attention to the relations of natural objects will show that the subject is inexhaustible; and all that we can or need do is to give a few examples, such as may show the nature of the impression which the examination of the universe produces. 3. Another instance of the adjustment of organic structure to the force of gravity may be pointed out in the muscular powers of animals. If the force of gravity were increased in any considerable proportion at the surface of the earth, it is manifest that all the swiftness, and strength, and grace of animal motions must disappear. If, for instance, the earth were as large as Jupiter, gravity would be eleven times what it is, the lightness of the fawn, the speed of the hare, the spring of the tiger, could no longer exist with the existing muscular powers of those animals; for man to lift himself upright, or to crawl from place to place, would be a labour slower and more painful than the motions of the sloth. The density and pressure of the air too would be increased to an intolerable extent, and the operation of respiration, and others, which depend upon these mechanical properties, would be rendered laborious, ineffectual, and probably impossible. If, on the other hand, the force of gravity were much lessened, inconveniences of an opposite kind would occur. The air would be too thin to breathe; the weight of our bodies, and of all the substances surrounding us, would become too slight to resist the perpetually occurring causes of derangement and unsteadiness: we should feel a want of ballast in our movements. It has sometimes been maintained by fanciful theorists that the earth is merely a shell, and that the central parts are hollow. All the reasons we can collect appear to be in favour of its being a solid mass, considerably denser than any known rock. If this be so, and if we suppose the interior to be at any time scooped out, so as to leave only such a shell as the above mentioned speculators have asserted, we should not be left in ignorance of the change, though the appearance of the surface might remain the same. We should discover the want of the usual force of gravity, by the instability of all about us. Things would not lie where we placed them, but would slide away with the slightest push. We should have a difficulty in standing or walking, something like what we have on ship-board when the deck is inclined; and we should stagger helplessly through an atmosphere thinner than that which oppresses the respiration of the traveller on the tops of the highest mountains. We see therefore that those dark and unknown central portions of the earth, which are placed far beyond the reach of the miner and the geologist, and of which man will probably never know anything directly, are not to be considered as quite disconnected with us, as deposits of useless lumber without effect or purpose. We feel their influence on every step we take and on every breath we draw; and the powers we possess, and the comforts we enjoy would be unprofitable to us, if they had not been prepared with a reference to those as well as to the near and visible portions of the earth’s mass. The arbitrary quantity, therefore, of which we have been treating, the intensity of the force of gravity, appears to have been taken account of, in establishing the laws of those forces by which the processes of vegetable and animal life are carried on. And this leads us inevitably, we conceive, to the belief of a supreme contriving mind, by which these laws were thus devised and thus established. CHAPTER IV. _The Magnitude of the Ocean._ There are several arbitrary quantities which contribute to determine the state of things at the earth’s surface besides those already mentioned. Some of these we shall briefly refer to, without pursuing the subject into detail. We wish not only to show that the properties and processes of vegetable and animal life must be adjusted to each of these quantities in particular, but also to point out how numerous and complicated the conditions of the existence of organized beings are; and we shall thus be led to think less inadequately of the intelligence which has embraced at once, and combined without confusion, all these conditions. We appear thus to be conducted to the conviction not only of design and intention, but of supreme knowledge and wisdom. One of the quantities which enters into the constitution of the terrestrial system of things is the bulk of the waters of the ocean. The mean depth of the sea, according to the calculations of Laplace, is four or five miles. On this supposition, the addition to the sea of one-fourth of the existing waters would drown the whole of the globe, except a few chains of mountains. Whether this be exact or no, we can easily conceive the quantity of water which lies in the cavities of our globe to be greater or less than it at present is. With every such addition or subtraction the form and magnitude of the dry land would vary, and if this change were considerable, many of the present relations of things would be altered. It may be sufficient to mention one effect of such a change. The sources which water the earth, both clouds, rains, and rivers, are mainly fed by the aqueous vapour raised from the sea; and therefore if the sea were much diminished, and the land increased, the mean quantity of moisture distributed upon the land must be diminished, and the character of climates, as to wet and dry, must be materially affected. Similar, but opposite changes would result from the increase of the surface of the ocean. It appears then that the magnitude of the ocean is one of the conditions to which the structure of all organized beings which are dependent upon climate must be adapted. CHAPTER V. _The Magnitude of the Atmosphere._ The total quantity of air of which our atmosphere is composed is another of the arbitrary magnitudes of our terrestrial system; and we may apply to this subject considerations similar to those of the last section. We can see no reason why the atmosphere might not have been larger in comparison to the globe which it surrounds; those of Mars and Jupiter appear to be so. But if the quantity of air were increased, the structure of organized beings would in many ways cease to be adapted to their place. The atmospheric pressure, for instance, would be increased, which, as we have already noticed, would require an alteration in the structure of vegetables. Another way in which an increase of the mass of the atmosphere would produce inconvenience would be in the force of winds. If the current of air in a strong gale were doubled or tripled, as might be the case if the atmosphere were augmented, the destructive effects would be more than doubled or tripled. With such a change, nothing could stand against a storm. In general, houses and trees resist the violence of the wind; and except in extreme cases, as for instance in occasional hurricanes in the West Indies, a few large trees in a forest are unusual trophies of the power of the tempest. The breezes which we commonly have are harmless messengers to bring about the salutary changes of the atmosphere, even the motion which they communicate to vegetables tends to promote their growth, and is so advantageous, that it has been proposed to imitate it by artificial breezes in the hothouse. But with a stream of wind blowing against them, like three, or five, or ten, gales compressed into the space of one, none of the existing trees could stand; and except they could either bend like rushes in a stream, or extend their roots far wider than their branches, they must be torn up in whole groves. We have thus a manifest adaptation of the present usual strength of the materials and of the workmanship of the world to the stress of wind and weather which they have to sustain. CHAPTER VI. _The Constancy and Variety of Climates._ It is possible to conceive arrangements of our system, according to which all parts of the earth might have the same, or nearly the same, climate. If, for example, we suppose the earth to be a flat disk, or flat ring, like the ring of Saturn, revolving in its own plane as that does, each part of both the flat surfaces would have the same exposure to the sun, and the same temperature, so far as the sun’s effect is concerned. There is no obvious reason why a planet of such a form might not be occupied by animals and vegetables, as well as our present earth; and on this supposition the climate would be every where the same, and the whole surface might be covered with life, without the necessity of there being any difference in the kind of inhabitants belonging to different parts. Again, it is possible to conceive arrangements according to which no part of our planet should have any steady climate. This may probably be the case with a comet. If we suppose such a body, revolving round the sun in a very oblong ellipse, to be of small size and of a very high temperature, and therefore to cool rapidly; and if we suppose it also to be surrounded by a large atmosphere, composed of various gases; there would, on the surface of such a body, be no average climate or seasons for each place. The years, if we give this name to the intervals of time occupied by its successive revolutions, would be entirely unlike one another. The greatest heat of one year might be cool compared with the greatest cold of a preceding one. The greatest heats and colds might succeed each other at intervals perpetually unequal. The atmosphere might be perpetually changing its composition by the condensation of some of its constituent gases. In the operations of the elements, all would be incessant and rapid change, without recurrence or compensation. We cannot say that organized beings could not be fitted for such a habitation; but if they were, the adaptation must be made by means of a constitution quite different from that of almost all organized beings known to us. The state of things upon the earth, in its present condition, is very different from both these suppositions. The climate of the same place, notwithstanding perpetual and apparently irregular change, possesses a remarkable steadiness. And, though in different places the annual succession of appearances in the earth and heavens, is, in some of its main characters, the same, the result of these influences in the average climate is very different. Now, to this remarkable constitution of the earth as to climate, the constitution of the animal and vegetable world is precisely adapted. The differences of different climates are provided for by the existence of entirely different classes of plants and animals in different countries. The constancy of climate at the same place is a necessary condition of the prosperity of each species there fixed. We shall illustrate, by a few details, these characteristics in the constitution of inorganic and of organic nature, with the view of fixing the reader’s attention upon the correspondence of the two. 1. The succession and alternation, at any given place, of heat and cold, rain and sunshine, wind and calm, and other atmospheric changes, appears at first sight to be extremely irregular, and not subject to any law. It is, however, easy to see, with a little attention, that there is a certain degree of constancy in the average weather and seasons of each place, though the particular facts of which these generalities are made up seem to be out of the reach of fixed laws. And when we apply any numerical measure to these particular occurrences, and take the average of the numbers thus observed, we generally find a remarkably close correspondence in the numbers belonging to the whole, or to analogous portions of successive years. This will be found to apply to the measures given by the thermometer, the barometer, the hygrometer, the rain gauge, and similar instruments. Thus it is found that very hot summers, or very cold winters, raise or depress the mean annual temperature very little above or below the general standard. The heat may be expressed by degrees of the thermometer; the temperature of the day is estimated by this measure taken at a certain period of the day, which is found by experience to correspond with the daily average; and the mean annual temperature will then be the average of all the heights of the thermometer for every day in the year. The mean annual temperature of London, thus measured, is about 50 degrees 4-10ths. The frost of the year 1788 was so severe that the Thames was passable on the ice; the mean temperature of that year was 50 degrees 6-10ths, being within a small fraction a degree of the standard. In 1796, when the greatest cold ever observed in London occurred, the mean temperature of the year was 50 degrees 1-10th, which is likewise within a fraction of a degree of the standard. In the severe winter of 1813-14, when the Thames, Tyne, and other large rivers in England were completely frozen over, the mean temperature of the two years was 49 degrees, being little more than a degree below the standard. And in the year 1808, when the summer was so hot that the temperature in London was as high as 93½ degrees, the mean heat of the year was 50½, which is about that of the standard. The same numerical indications of the constancy of climate at the same place might be collected from the records of other instruments of the kind above-mentioned. We shall, hereafter, consider some of the very complex agencies by which this steadiness is produced; and shall endeavour to point out intentional adaptations to this object. But we may, in the meantime, observe how this property of the atmospheric changes is made subservient to a further object. To this constancy of the climates of each place, the structure of plants is adapted; almost all vegetables require a particular mean temperature of the year, or of some season of the year; a particular degree of moisture, and similar conditions. This will be seen by observing that the range of most plants as to climate is very limited. A vegetable which flourishes where the mean temperature is 55 degrees, would pine and wither when removed to a region where the average is 50 degrees. If, therefore, the average at each place were to vary as much as this, our plants with their present constitutions would suffer, languish, and soon die. 2. It will be readily understood that the same mode of measurement by which we learn the constancy of climate at the same place, serves to show us the variety which belongs to different places. While the variations of the same region vanish when we take the averages even of moderate periods, those of distant countries are fixed and perpetual; and stand out more clear and distinct, the longer is the interval for which we measure their operation. In the way of measuring already described, the mean temperature of Petersburg is 39 degrees, of Rome 60, of Cairo 72. Such observations as these, and others of the same kind, have been made at various places, collected and recorded; and in this way the surface of the earth can be divided by boundary lines into various strips, according to these physical differences. Thus, the zones which take in all the places having the same or nearly the same mean annual temperature, have been called _isothermal_ zones. These zones run nearly parallel to the equator, but not exactly, for, in Europe, they bend to the north in going eastward. In the same manner, the lines passing through all places which have an equal temperature for the summer or the winter half of the year, have been called respectively _isotheral_ and _isochimal_ lines. These do not coincide with the isothermal lines, for a place may have the same temperature as another, though its summer be hotter and its winter colder, as is the case of Pekin compared with London. In the same way we might conceive lines drawn according to the conditions of clouds, rain, wind, and the like circumstances, if we had observations enough to enable us to lay down such lines. The course of vegetation depends upon the combined influence of all such conditions; and the lines which bound the spread of particular vegetable productions do not, in most cases, coincide with any of the separate meteorological boundaries above spoken of. Thus, the northern limit of vineyards runs through France, in a direction very nearly north-east and south-west, while the line of equal temperature is nearly east and west. And the spontaneous growth or advantageous cultivation of other plants, is in like manner bounded by lines of which the course depends upon very complex causes, but of which the position is generally precise and fixed. CHAPTER VII. _The Variety of Organization corresponding to the Variety of Climate._ The organization of plants and animals is in different tribes formed upon schemes more or less different, but in all cases adjusted in a general way to the course and action of the elements. The differences are connected with the different habits and manners of living which belong to different species; and at any one place the various species, both of animals and plants, have a number of relations and mutual dependences arising out of these differences. But besides the differences of this kind, we find in the forms of organic life another set of differences, by which the animal and vegetable kingdom are fitted for that variety in the climates of the earth, which we have been endeavouring to explain. The existence of such differences is too obvious to require to be dwelt upon. The plants and animals which flourish and thrive in countries remote from each other, offer to the eye of the traveller a series of pictures, which, even to an ignorant and unreflective spectator, is full of a peculiar and fascinating interest in consequence of the novelty and strangeness of the successive scenes. Those who describe the countries between the tropics, speak with admiration of the luxuriant profusion and rich variety of the vegetable productions of those regions. Vegetable life seems there far more vigorous and active, the circumstances under which it goes on, far more favourable than in our latitudes. Now if we conceive an inhabitant of those regions, knowing, from the circumstances of the earth’s form and motion, the difference of climates which must prevail upon it, to guess, from what he saw about him, the condition of other parts of the globe as to vegetable wealth, is not likely that he would suppose that the extra-tropical climates must be almost devoid of plants? We know that the ancients, living in the temperate zone, came to the conclusion that both the torrid and the frigid zones must be uninhabitable. In like manner the equatorial reasoner would probably conceive that vegetation must cease, or gradually die away, as he should proceed to places further and further removed from the genial influence of the sun. The mean temperature of his year being about 80 degrees, he would hardly suppose that any plants could subsist through a year, where the mean temperature was only 50, where the temperature of the summer quarter was only 64, and where the mean temperature of a whole quarter of the year was a very few degrees removed from that at which water becomes solid. He would suppose that scarcely any tree, shrub, or flower could exist in such a state of things, and so far as the plants of his own country are concerned, he would judge rightly. But the countries further removed from the equator are not left thus unprovided. Instead of being scantily occupied by such of the tropical plants as could support a stunted and precarious life in ungenial climes, they are abundantly stocked with a multitude of vegetables which appear to be constructed expressly for them, inasmuch as these species can no more flourish at the equator than the equatorial species can in these temperate regions. And such new supplies thus adapted to new conditions, recur perpetually as we advance towards the apparently frozen and untenantable regions in the neighbourhood of the pole. Every zone has its peculiar vegetables; and as we miss some, we find others make their appearance, as if to replace those which are absent. If we look at the indigenous plants of Asia and Europe, we find such a succession as we have here spoken of. At the equator we find the natives of the Spice Islands, the clove and nutmeg trees, pepper and mace. Cinnamon bushes clothe the surface of Ceylon; the odoriferous sandal wood, the ebony tree, the teak tree, the banyan, grow in the East Indies. In the same latitudes in Arabia the Happy we find balm, frankincense and myrrh, the coffee tree, and the tamarind. But in these countries, at least in the plains, the trees and shrubs which decorate our more northerly climes are wanting. And as we go northwards, at every step we change the vegetable group, both by addition and by subtraction. In the thickets to the west of the Caspian Sea we have the apricot, citron, peach, walnut. In the same latitude in Spain, Sicily, and Italy, we find the dwarf palm, the cypress, the chestnut, the cork tree: the orange and lemon tree perfume the air with their blossoms; the myrtle and pomegranate grow wild among the rocks. We cross the Alps, and we find the vegetation which belongs to northern Europe, of which England is an instance. The oak, the beech, and the elm are natives of Great Britain: the elm tree seen in Scotland, and in the north of England, is the wych elm. As we travel still further to the north the forests again change their character. In the northern provinces of the Russian empire are found forests of the various species of firs: the Scotch and spruce fir, and the larch. In the Orkney Islands no tree is found but the hazel, which occurs again on the northern shores of the Baltic. As we proceed into colder regions we still find species which appear to have been made for these situations. The hoary or cold elder makes its appearance north of Stockholm: the sycamore and mountain ash accompany us to the head of the gulf of Bothnia: and as we leave this and traverse the Dophrian range, we pass in succession the boundary lines of the spruce fir, the Scotch fir, and those minute shrubs which botanists distinguish as the dwarf birch and dwarf willow. Here, near to or within the arctic circle, we yet find wild flowers of great beauty; the mezereum, the yellow and white water lily, and the European globe flower. And when these fail us, the reindeer moss still makes the country habitable for animals and man. We have thus a variety in the laws of vegetable organization remarkably adapted to the variety of climates; and by this adaptation the globe is clothed with vegetation and peopled with animals from pole to pole, while without such an adaptation vegetable and animal life must have been confined almost, or entirely, to some narrow zone on the earth’s surface. We conceive that we see here the evidence of a wise and benevolent intention, overcoming the varying difficulties, or employing the varying resources of the elements, with an inexhaustible fertility of contrivance, a constant tendency to diffuse life and well being. 2. One of the great uses to which the vegetable wealth of the earth is applied, is the support of man, whom it provides with food and clothing; and the adaptation of tribes of indigenous vegetables to every climate has, we cannot but believe, a reference to the intention that the human race should be diffused over the whole globe. But this end is not answered by indigenous vegetables alone; and in the variety of vegetables capable of being _cultivated_ with advantage in various countries, we conceive that we find evidence of an additional adaptation of the scheme of organic life to the system of the elements. The cultivated vegetables, which form the necessaries or luxuries of human life, are each confined within limits, narrow, when compared with the whole surface of the earth; yet almost every part of the earth’s surface is capable of being abundantly covered with one kind or other of these. When one class fails, another appears in its place. Thus corn, wine, and oil, have each its boundaries. Wheat extends through the old Continent, from England to Thibet: but it stops soon in going northwards, and is not found to succeed in the west of Scotland. Nor does it thrive better in the torrid zone than in the polar regions: within the tropics, wheat, barley and oats are not cultivated, excepting in situations considerably above the level of the sea: the inhabitants of those countries have other species of grain, or other food. The cultivation of the vine succeeds only in countries where the annual temperature is between 50 and 63 degrees. In both hemispheres, the profitable culture of this plant ceases within 30 degrees of the equator, unless in elevated situations, or in islands, as Teneriffe. The limits of the cultivation of maize and of olives in France are parallel to those which bound the vine and corn in succession to the north. In the north of Italy, west of Milan, we first meet with the cultivation of rice; which extends over all the southern part of Asia, wherever the land can be at pleasure covered with water. In great part of Africa millet is one of the principal kinds of grain. Cotton is cultivated to latitude 40 in the new world, but extends to Astrachan in latitude 46 in the old. The sugar cane, the plantain, the mulberry, the betel nut, the indigo tree, the tea tree, repay the labours of the cultivator in India and China; and several of these plants have been transferred, with success, to America and the West Indies. In equinoctial America a great number of inhabitants find abundant nourishment on a narrow space cultivated with plantain, cassava yams, and maize. The bread fruit tree begins to be cultivated in the Manillas, and extends through the Pacific; the sago palm in the Moluccas, the cabbage tree in the Pelew islands. In this manner the various tribes of men are provided with vegetable food. Some however live on their cattle, and thus make the produce of the earth only mediately subservient to their wants. Thus the Tartar tribes depend on their flocks and herds for food: the taste for the flesh of the horse seems to belong to the Mongols, Fins, and other descendants of the ancient Scythians: the locust eaters are found now, as formerly, in Africa. Many of these differences depend upon custom, soil, and other causes with which we do not here meddle; but many are connected with climate: and the variety of the resources which man thus possesses, arises from the variety of constitution belonging to cultivable vegetables, through which one is fitted to one range of climate, and another to another. We conceive that this variety and succession of fitness for cultivation, shows undoubted marks of a most foreseeing and benevolent design in the Creator of man and of the world. 3. By differences in vegetables of the kind we have above described, the sustentation and gratification of man’s physical nature is copiously provided for. But there is another circumstance, a result of the difference of the native products of different regions, and therefore a consequence of that difference of climate on which the difference of native products depends,[5] which appears to be worthy our notice. The difference of the productions of different countries has a bearing not only upon the physical, but upon the social and moral condition of man. The intercourse of nations in the way of discovery, colonization, commerce; the study of the natural history, manners, institutions of foreign countries; lead to most numerous and important results. Without dwelling upon this subject, it will probably be allowed that such intercourse has a great influence upon the comforts, the prosperity, the arts, the literature, the power, of the nations which thus communicate. Now the variety of the productions of different lands supplies both the stimulus to this intercourse, and the instruments by which it produces its effects. The desire to possess the objects or the knowledge which foreign countries alone can supply, urges the trader, the traveller, the discoverer to compass land and sea; and the progress of the arts and advantages of civilization consists almost entirely in the cultivation, the use, the improvement of that which has been received from other countries. This is the case to a much greater extent than might at first sight be supposed. Where man is active as a cultivator, he scarcely ever bestows much of his care on those vegetables which the land would produce in a state of nature. He does not select some of the plants of the soil and improve them by careful culture, but, for the most part, he expels the native possessors of the land, and introduces colonies of strangers. Thus, to take the condition of our own part of the globe as an example; scarcely one of the plants which occupy our fields and gardens is indigenous to the country. The walnut and the peach come to us from Persia; the apricot from Armenia: from Asia Minor, and Syria, we have the cherry tree, the fig, the pear, the pomegranate, the olive, the plum, and the mulberry. The vine which is now cultivated is not a native of Europe; it is found wild on the shores of the Caspian, in Armenia and Caramania. The most useful species of plants, the _cereal_ vegetables, are certainly strangers, though their birth place seems to be an impenetrable secret. Some have fancied that barley is found wild on the banks of the Semara, in Tartary, rye in Crete, wheat at Baschkiros, in Asia; but this is held by the best botanists to be very doubtful. The potatoe, which has been so widely diffused over the world in modern times, and has added so much to the resources of life in many countries, has been found equally difficult to trace back to its wild condition. Thus widely are spread the traces of the connexion of the progress of civilization with national intercourse. In our own country a higher state of the arts of life is marked by a more ready and extensive adoption of foreign productions. Our fields are covered with herbs from Holland, and roots from Germany; with Flemish farming and Swedish turnips; our hills with forests of the firs of Norway. The chestnut and poplar of the south of Europe adorn our lawns, and below them flourish shrubs and flowers from every clime in profusion. In the mean time Arabia improves our horses, China our pigs, North America our poultry, Spain our sheep, and almost every country sends its dog. The products which are ingredients in our luxuries, and which we cannot naturalize at home, we raise in our colonies; the cotton, coffee, sugar of the east are thus transplanted to the farthest west; and man lives in the middle of a rich and varied abundance which depends on the facility with which plants and animals and modes of culture can be transferred into lands far removed from those in which nature had placed them. And this plenty and variety of material comforts is the companion and the mark of advantages and improvements in social life, of progress in art and science, of activity of thought, of energy of purpose, and of ascendancy of character. The differences in the productions of different countries which lead to the habitual intercourse of nations, and through this to the benefits which we have thus briefly noticed, do not all depend upon the differences of temperature and climate alone. But these differences are among the causes, and are some of the most important causes, or conditions, of the variety of products; and thus that arrangement of the earth’s form and motion from which the different climates of different places arises, is connected with the social and moral welfare and advancement of man. We conceive that this connexion, though there must be to our apprehension much that is indefinite and uncertain in tracing its details, is yet a point where we may perceive the profound and comprehensive relations established by the counsel and foresight of a wise and good Creator of the world and of man, by whom the progress and elevation of the human species was neither uncontemplated nor uncared for. 4. We have traced, in the variety of organized beings, an _adaptation_ to the variety of climates, a _provision_ for the sustentation of man all over the globe, and an _instrument_ for the promotion of civilization and many attendant benefits. We have not considered this _variety_ as _itself_ a purpose which we can perceive or understand without reference to some ulterior end. Many persons, however, and especially those who are already in the habit of referring the world to its Creator, will probably see something admirable in itself in this vast variety of created things. There is indeed something well fitted to produce and confirm a reverential wonder, in these apparently inexhaustible stores of new forms of being and modes of existence; the fixity of the laws of each class, its distinctness from all others, its relations to many. Structures and habits and characters are exhibited, which are connected and distinguished according to every conceivable degree of subordination and analogy, in their resemblances and in their differences. Every new country we explore presents us with new combinations, where the possible cases seem to be exhausted; and with new resemblances and differences, constructed as if to elude what conjecture might have hit upon, by proceeding from the old ones. Most of those who have any large portion of nature brought under their notice in this point of view, are led to feel that there is, in such a creation, a harmony, a beauty, and a dignity, of which the impression is irresistible; which would have been wanting in any more uniform and limited system such as we might try to imagine; and which of itself gives to the arrangements by which such a variety on the earth’s surface is produced, the character of well devised means to a worthy end. CHAPTER VIII. _The Constituents of Climate._ We have spoken of the steady average of the climate at each place, of the difference of this average at different places, and of the adaptation of organized beings to this character in the laws of the elements by which they are affected. But this steadiness in the general effect of the elements, is the result of an extremely complex and extensive machinery. Climate, in its wider sense, is not one single agent, but is the aggregate result of a great number of different agents, governed by different laws, producing effects of various kinds. The steadiness of this compound agency is not the steadiness of a permanent condition, like that of a body at rest; but it is the steadiness of a state of constant change and movement, succession and alternation, seeming accident and irregularity. It is a perpetual repose, combined with a perpetual motion; an invariable average of most variable quantities. Now, the manner in which such a state of things is produced, deserves, we conceive, a closer consideration. It may be useful to show how the particular laws of the action of each of the elements of climate are so adjusted that they do not disturb this general constancy. The principal constituents of climate are the following:--the temperature of the earth, of the water, of the air:--the distribution of the aqueous vapour contained in the atmosphere:--the winds and rains by which the equilibrium of the atmosphere is restored when it is in any degree disturbed. The effects of light, of electricity, probably of other causes also, are no doubt important in the economy of the vegetable world, but these agencies have not been reduced by scientific inquirers to such laws as to admit of their being treated with the same exactness and certainty which we can obtain in the case of those first mentioned. We shall proceed to trace some of the peculiarities in the laws of the different physical agents which are in action at the earth’s surface, and the manner in which these peculiarities bear upon the general result. _The Laws of Heat with respect to the Earth._ One of the main causes which determine the temperature of each climate is the effect of the sun’s rays on the solid mass of the earth. The laws of this operation have been recently made out with considerable exactness, experimentally by Leslie, theoretically by Fourier, and by other inquirers. The theoretical inquiries have required the application of very complex and abstruse mathematical investigations; but the general character of the operation may, perhaps, be made easily intelligible. The earth, like all solid bodies, transmits into its interior the impressions of heat which it receives at the surface; and throws off the superfluous heat from its surface into the surrounding space. These processes are called _conduction_ and _radiation_, and have each their ascertained mathematical laws. By the laws of conduction, the daily impressions of heat which the earth receives, follow each other into the interior of the mass, like the waves which start from the edge of a canal;[6] and like them, become more and more faint as they proceed, till they melt into the general level of the internal temperature. The heat thus transmitted is accumulated in the interior of the earth, as in a reservoir, and flows from one part to another of this reservoir. The parts of the earth near the equator are more heated by the sun than other parts, and on this account there is a perpetual internal conduction of heat from the equatorial to other parts of the sphere. And as all parts of the surface throw off heat by radiation, in the polar regions, where the surface receives little in return from the sun, a constant waste is produced. There is thus from the polar parts a perpetual dispersion of heat in the surrounding space, which is supplied by a perpetual internal flow from the equator towards each pole. Here, then, is a kind of circulation of heat; and the quantity and rapidity of this circulation, determine the quantity of heat in the solid part of the earth, and in each portion of it; and through this, the _mean_ temperature belonging to each point on its surface. If the earth _conducted_ heat more rapidly than it does, the inequalities of temperature would be more quickly balanced, and the temperature of the ground (below the reach of annual and diurnal variations) would differ less than it does. If the surface _radiated_ more rapidly than it does, the flow of heat from the polar regions would increase, and the temperature of the interior of the globe would find a lower level; the differences of temperature in different latitudes would increase, but the mean temperature of the globe would diminish. There is nothing which, so far as we can perceive, determines necessarily, either the conducting or the radiating power of the earth to its present value. The measures of such powers, in different substances, differ very widely. If the earth were a globe of pure iron, it would conduct heat, probably, twenty times as well as it does; if its surface were polished iron, it would only radiate one-sixth as much as it does. Changes in the amount of the conduction and radiation far less than these, would, probably, subvert the whole _thermal_ constitution of the earth, and make it uninhabitable by any of its present vegetable, or animal tenants. One of the results of the laws of heat, as they exist in the globe, is, that, by their action, the thermal state tends to a limiting condition, which, once reached, remains constant and steady, as it now is. The oscillations or excursions from the mean condition, produced by any temporary cause, are rapidly suppressed; the deviations of seasons from their usual standard produce only a small and transient effect. The impression of an extremely hot day upon the ground melts almost immediately into the average internal heat. The effect of a hot summer, in like manner, is soon lost in its progress through the globe. If this were otherwise, if the inequalities and oscillations of heat went on, through the interior of the earth, retaining the same value, or becoming larger and larger, we might have the extreme heats or colds of one place making their appearance at another place after a long interval; like a conflagration which creeps along a street and bursts out at a point remote from its origin. It appears, therefore, that both the present differences of climate, and the steadiness of the average at each place, depend upon the form of the present laws of heat, and on the arbitrary magnitudes which determine the rate of conduction and radiation. The laws are such as to secure us from increasing and destructive inequalities of heat; the arbitrary magnitudes are elements to which the organic world is adjusted. CHAPTER IX. _The Laws of Heat with respect to Water._ The manner in which heat is transmitted through fluids is altogether different from the mode in which it passes through solids; and hence the waters of the earth’s surface produce peculiar effects upon its condition as to temperature. Moreover, water is susceptible of evaporation in a degree depending upon the increase of heat; and in consequence of this property it has most extensive and important functions to discharge in the economy of nature. We will consider some of the offices of this fluid. 1. Heat is communicated through water, not by being _conducted_ from one part of the fluid to another, as in solid bodies, but (at least principally) by being _carried_ with the parts of the fluid by means of an intestine motion. Water expands and becomes lighter by heat, and, therefore, if the upper parts be cooled below the subjacent temperature, this upper portion will become heavier than that below, bulk for bulk, and will descend through it, while the lower portion rises to take the upper place. In this manner the colder parts descend, and the warmer parts ascend by contrary currents, and by their interchange and mixture, reduce the whole to a temperature at least as low as that of the surface. And this equalization of temperature by means of such currents, is an operation of a much more rapid nature than the slow motion of conduction by which heat creeps through a solid body. Hence, alternations of heat and cold, as day and night, summer and winter, produce in water, inequalities of temperature much smaller than those which occur in a solid body. The heat communicated is less, for transparent fluids imbibe heat very slowly; and the cold impressed on the surface is soon diffused through the mass by internal circulation. Hence it follows that the ocean, which covers so large a portion of the earth, and affects the temperature of the whole surface by its influence, produces the effect of making the alternations of heat and cold much less violent than they would be if it were absent. The different temperatures of its upper and lower parts produce a current which draws the seas, and by means of the seas, the air, towards the mean temperature. And this kind of circulation is produced, not only between the upper and lower parts, but also between distant tracts of the ocean. The great Gulf Stream which rushes out of the Gulf of Mexico, and runs across the Atlantic to the western shores of Europe, carries with it a portion of the tropical heat into northern regions: and the returning current which descends along the coast of Africa, tends to cool the parts nearer the equator. Great as the difference of temperature is in different climates, it would be still greater if there were not this equalizing and moderating power exerted constantly over the whole surface. Without this influence, it is probable that the two polar portions of the earth, which are locked in perpetual ice and snow, and almost destitute of life, would be much increased. We find an illustration of this effect of the ocean on temperature, in the peculiarities of the climates of maritime tracts and islands. The climate of such portions of the earth, corrected in some measure by the temperature of the neighbouring sea, is more equable than that of places in the same latitudes differently situated. London is cooler in summer and warmer in winter than Paris. 2. Water expands by heat and contracts by cold, as has been already said; and in consequence of this property, the coldest portions of the fluid generally occupy the lower parts. The continued progress of cold produces congelation. If, therefore, the law just mentioned had been strictly true, the lower parts of water would have been first frozen; and being once frozen, hardly any heat applied at the surface could have melted them, for the warm fluid could not have descended through the colder parts. This is so far the case, that in a vessel containing ice at the bottom and water at the top, Rumford made the upper fluid boil without thawing the congealed cake below. Now, a law of water with respect to heat operating in this manner, would have been very inconvenient if it had obtained in our lakes and seas. They would all have had a bed of ice, increasing with every occasion, till the whole was frozen. We could have had no bodies of water, except such pools on the surfaces of these icy reservoirs as the summer sun could thaw, to be again frozen to the bottom with the first frosty night. The law of the regular contraction of water by cold till it became ice, would, therefore, be destructive of all the utility of our seas and lakes. How is this inconvenience obviated? It is obviated by a modification of the law which takes place when the temperature approaches this limit. Water contracts by the increase of cold, till we come _near_ the freezing temperature; but then, by a further increase of cold, it contracts no more, but expands till the point at which it becomes ice. It contracts in cooling down to 40 degrees of Fahrenheit’s thermometer; in cooling further it expands, and when cooled to 32 degrees, it freezes. Hence, the greatest density of the fluid is at 40 degrees, and water of this temperature, or near it, will lie at the bottom with cooler water or with ice floating above it. However much the surface be cooled, water colder than 40 cannot descend to displace water warmer than itself. Hence we can never have ice formed at the bottom of deep water. In approaching the freezing point, the coldest water will rise to the surface, and the congelation will take place there; and the ice so formed will remain at the surface, exposed to the warmth of the sunbeams and the air, and will not survive any long continuance of such action. Another peculiarity in the laws which regulate the action of cold on water is, that in the very act of freezing a further sudden and considerable expansion takes place. Many persons will have known instances of vessels burst by the freezing of water in them. The consequence of this expansion is, that the specific gravity of ice is less than that of water of any temperature; and it therefore always floats in the unfrozen fluid. If this expansion of crystallization did not exist, ice would float in water which was below forty degrees, but would sink when the fluid was above that temperature: as the case is, it floats under all circumstances. The icy remnants of the effects of winter, which the river carries down its stream, are visible on its surface till they melt away; and the icebergs which are detached from the shores of the polar seas, drift along, exposed to the sun and air, as well as to the water in which they are immersed. These laws of the effect of temperature on water are truly remarkable in their adaptation to the beneficial course of things at the earth’s surface. Water contracts by cold; it thus equalizes the temperature of various times and places; but if its contraction were continued all the way to the freezing point, it would bind a great part of the earth in fetters of ice. The contraction then is here replaced by expansion, in a manner which but slightly modifies the former effects, while it completely obviates the bad consequences. The further expansion which takes place at the point of freezing, still further facilitates the rapid removal of the icy chains, in which parts of the earth’s surface are at certain seasons bound. We do not know how far these laws of expansion are connected with and depend on more remote and general properties of this fluid, or of all fluids. But we have no reason to believe that, by whatever means they operate, they are not laws selected from among other laws which might exist, as in fact for other fluids other laws do exist. And we have all the evidence, which the most remarkable furtherance of important purposes can give us, that they _are_ selected, and selected with a beneficial design. 3. As water becomes ice by cold, it becomes steam by heat. In common language, steam is the name given to the vapour of _hot_ water; but in fact a vapour or steam rises from water at all temperatures, however low, and even from ice. The expansive force of this vapour increases rapidly as the heat increases; so that when we reach the heat of boiling water, it operates in a far more striking manner than when it is colder; but in all cases the surface of water is covered with an atmosphere of aqueous vapour, the pressure or _tension_ of which is limited by the temperature of the water. To each degree of pressure in steam there is a _constituent temperature_ corresponding. If the surface of water is not pressed by vapour with the force thus corresponding to its temperature, an immediate _evaporation_ will supply the deficiency. We can compare the tension of such vapour with that of our common atmosphere; the pressure of the latter is measured by the barometrical column, about thirty inches of mercury; that of watery vapour is equal to one inch of mercury at the constituent temperature of 80 degrees, and to one-fifth of an inch, at the temperature of 32 degrees. Hence, if that part of the atmosphere which consists of common air were annihilated, there would still remain an atmosphere of aqueous vapour, arising from the waters and moist parts of the earth; and in the existing state of things this vapour rises in the atmosphere of dry air. Its distribution and effects are materially influenced by the vehicle in which it is thus carried, as we shall hereafter notice; but at present we have to observe the exceeding _utility_ of water in this shape. We remark how suitable and indispensable to the well-being of the creation it is, that the fluid should possess the property of assuming such a form under such circumstances. The _moisture_ which floats in the atmosphere is of most essential use to vegetable life.[7] “The leaves of living plants appear to act upon this vapour in its elastic form, and to absorb it. Some vegetables increase in weight from this cause when suspended in the atmosphere and unconnected with the soil, as the house-leek and the aloe. In very intense heats, and when the soil is dry, the life of plants seems to be preserved by the absorbent power of their leaves.” It follows from what has already been said, that, with an increasing heat of the atmosphere, an increasing quantity of vapour will rise into it, if supplied from any quarter. Hence it appears that aqueous vapour is most abundant in the atmosphere when it is most needed for the purposes of life; and that when other sources of moisture are cut off, this is most copious. 4. _Clouds_ are produced by aqueous vapour when it returns to the state of water. This process is _condensation_, the reverse of evaporation. When vapour exists in the atmosphere, if in any manner the temperature becomes lower than the _constituent temperature_, requisite for the maintenance of the vapoury state, some of the steam will be condensed and will become water. It is in this manner that the curl of steam from the spout of a boiling tea-kettle becomes visible, being cooled down as it rushes to the air. The steam condenses into a fine watery powder, which is carried about by the little aerial currents. Clouds are of the same nature with such curls, the condensation being generally produced when air, charged with aqueous vapour, is mixed with a colder current, or has its temperature diminished in any other manner. Clouds, while they retain that shape, are of the most essential use to vegetable and animal life. They moderate the fervour of the sun, in a manner agreeable, to a greater or less degree, in all climates, and grateful no less to vegetables than to animals. Duhamel says that plants grow more during a week of cloudy weather than a month of dry and hot. It has been observed that vegetables are far more refreshed by being watered in cloudy than in clear weather. In the latter case, probably the supply of fluid is too rapidly carried off by evaporation. Clouds also moderate the alternations of temperature, by checking the radiation from the earth. The coldest nights are those which occur under a cloudless winter sky. The uses of clouds, therefore, in this stage of their history, are by no means inconsiderable, and seem to indicate to us that the laws of their formation were constructed with a view to the purposes of organized life. 5. Clouds produce _rain_. In the formation of a cloud the precipitation of moisture probably forms a fine watery _powder_, which remains suspended in the air in consequence of the minuteness of its particles: but if from any cause the precipitation is collected in larger portions, and becomes _drops_, these descend by their weight and produce a shower. However rain is formed, it is one of the consequences of the capacity of evaporation and condensation which belongs to water, and its uses are the result of the laws of those processes. Its uses to plants are too obvious and too numerous to be described. It is evident that on its quantity and distribution depend in a great measure the prosperity of the vegetable kingdom: and different climates are fitted for different productions, no less by the relations of dry weather and showers, than by those of hot and cold. 6. Returning back still further in the changes which cold can produce on water, we come to _snow_ and _ice_: snow being apparently frozen vapour, aggregated by a confused action of crystalline laws; and ice being water in its fluid state, solidified by the same crystalline forces. The impression of these agents on the animal feelings is generally unpleasant, and we are in the habit of considering them as symptoms of the power of winter to interrupt that state of the elements in which they are subservient to life. Yet, even in this form, they are not without their uses.[8] “Snow and ice are bad conductors of cold; and when the ground is covered with snow, or the surface of the soil or of water is frozen, the roots or bulbs of plants beneath are protected by the congealed water from the influence of the atmosphere, the temperature of which, in northern winters, is usually very much below the freezing point; and this water becomes the first nourishment of the plant in early spring. The expansion of water during its congelation, at which time its volume increases one-twelfth, and its contraction in bulk during a thaw, tend to pulverize the soil, to separate its parts from each other, and to make it more permeable to the influence of the air.” In consequence of the same slowness in the conduction of heat which snow thus possesses, the arctic traveller finds his bed of snow of no intolerable coldness; the Esquimaux is sheltered from the inclemency of the season in his snow hut, and travels rapidly and agreeably over the frozen surface of the sea. The uses of those arrangements, which at first appear productive only of pain and inconvenience, are well suited to give confidence and hope to our researches for such usefulness in every part of the creation. They have thus a peculiar value in adding connexion and universality to our perception of beneficial design. 7. There is a peculiar circumstance still to be noticed in the changes from ice to water and from water to steam. These changes take place at a particular and invariable degree of heat; yet they do not take place suddenly when we increase the heat to this degree. This is a very curious arrangement. The temperature _makes a stand_, as it were, at the point where thaw, and where boiling take place. It is necessary to apply a considerable quantity of heat to produce these effects; all which heat disappears, or becomes _latent_, as it is called. We cannot raise the temperature of a thawing mass of ice till we have thawed the whole. We cannot raise the temperature of boiling water, or of steam rising from it, till we have converted all the water into steam. Any heat that we apply while these changes are going on is absorbed in producing the changes. The consequences of this property of _latent heat_ are very important. It is on this account that the changes now spoken of necessarily occupy a considerable time. Each part in succession must have a proper degree of heat applied to it. If it were otherwise, thaw and evaporation must be instantaneous: at the first touch of warmth, all the snow which lies on the roofs of our houses would descend like a waterspout into the streets: all that which rests on the ground would rush like an inundation into the water courses. The hut of the Esquimaux would vanish like a house in a pantomime: the icy floor of the river would be gone without giving any warning to the skaiter or the traveller: and when, in heating our water, we reached the boiling point, the whole fluid would “flash into steam,” (to use the expression of engineers,) and dissipate itself in the atmosphere, or settle in dew on the neighbouring objects. It is obviously necessary for the purposes of human life, that these changes should be of a more gradual and manageable kind than such as we have now described. Yet this gradual progress of freezing and thawing, of evaporation and condensation, is produced, so far as we can discover, by a particular contrivance. Like the freezing of water from the top, or the floating of ice, the moderation of the rate of these changes seems to be the result of a _violation_ of a law: that is, the simple rule regarding the effects of change of temperature, which at first sight appears to be the law, and which, from its simplicity, would seem to us the most obvious laws for these as well as other cases, is modified at certain critical points, _so as to_ produce these advantageous effects:--why may we not say _in order to_ produce such effects? 8. Another office of water which it discharges by means of its relations to heat, is that of supplying our _springs_. There can be no doubt that the old hypotheses which represent springs as drawing their supplies from large subterranean reservoirs of water, or from the sea by a process of subterraneous filtration, are erroneous and untenable. The quantity of evaporation from water and from wet ground is found to be amply sufficient to supply the requisite drain. Mr. Dalton calculated[9] that the quantity of rain which falls in England is thirty-six inches a year. Of this he reckoned that thirteen inches flow off to the sea by the rivers, and that the remaining twenty-three inches are raised again from the ground by evaporation. The thirteen inches of water are of course supplied by evaporation from the sea, and are carried back to the land through the atmosphere. Vapour is perpetually rising from the ocean, and is condensed in the hills and high lands, and through their pores and crevices descends, till it is deflected, collected, and conducted out to the bay, by some stratum or channel which is watertight. The condensation which takes place in the higher parts of the country, may easily be recognised in the mists and rains which are the frequent occupants of such regions. The coldness of the atmosphere and other causes precipitate the moisture in clouds and showers, and in the former as well as in the latter shape, it is condensed and absorbed by the cool ground. Thus a perpetual and compound circulation of the waters is kept up; a narrower circle between the evaporation and precipitation of the land itself, the rivers and streams only occasionally and partially forming a portion of the circuit; and a wider interchange between the sea and the lands which feed the springs, the water ascending perpetually by a thousand currents through the air, and descending by the gradually converging branches of the rivers, till it is again returned into the great reservoir of the ocean. In every country, these two portions of the aqueous circulation have their regular, and nearly constant, proportion. In this kingdom the relative quantities are, as we have said, twenty-three and thirteen. A due distribution of these circulating fluids in each country appears to be necessary to its organic health; to the habits of vegetables, and of man. We have every reason to believe that it is kept up from year to year as steadily as the circulation of the blood in the veins and arteries of man. It is maintained by a machinery very different, indeed, from that of the human system, but apparently as well, and, therefore, we may say as clearly, as that, adapted to its purposes. By this machinery, we have a connexion established between the atmospheric changes of remote countries. Rains in England are often introduced by a south-east wind. “Vapour brought to us by such a wind, must have been generated in countries to the south and east of our island. It is, therefore, probably, in the extensive valleys watered by the Meuse, the Moselle, and the Rhine, if not from the more distant Elbe, with the Oder and the Weser, that the water rises, in the midst of sunshine, which is soon afterwards to form _our_ clouds, and pour down _our_ thunder-showers.” “Drought and sunshine in one part of Europe may be as necessary to the production of a wet season in another, as it is on the great scale of the continents of Africa and South America; where the plains, during one-half the year, are burnt up, to feed the springs of the mountain; which in their turn contribute to inundate the fertile valleys and prepare them for a luxuriant vegetation.”[10] The properties of water which regard heat make one vast _watering-engine_ of the atmosphere. CHAPTER X. _The Laws of Heat with respect to Air._ We have seen in the preceding chapter how many and how important are the offices discharged by the aqueous part of the atmosphere. The aqueous part is, however, a very small part only; it may vary, perhaps, from less than 1-100th to nearly as much as 1-20th in weight, of the whole aerial ocean. We have to offer some considerations with regard to the remainder of the mass. 1. In the first place we may observe that the aerial atmosphere is necessary as a vehicle for the aqueous vapour. Salutary as is the operation of this last element to the whole organized creation, it is a substance which would not have answered its purposes if it had been administered pure. It requires to be diluted and associated with dry air, to make it serviceable. A little consideration will show this. We can suppose the earth with no atmosphere except the vapour which arises from its watery parts: and if we suppose also the equatorial parts of the globe to be hot, and the polar parts cold, we may easily see what would be the consequence. The waters at the equator, and near the equator, would produce steam of greater elasticity, rarity, and temperature, than that which occupies the regions further _polewards_; and such steam, as it came in contact with the colder vapour of a higher latitude, would be precipitated into the form of water. Hence there would be a perpetual current of steam from the equatorial parts towards each pole, which would be condensed, would fall to the surface, and flow back to the equator in the form of fluid. We should have a circulation which might be regarded as a species of regulated distillation.[11] On a globe so constituted, the sky of the equatorial zone would be perpetually cloudless; but in all other latitudes we should have an uninterrupted shroud of clouds, fogs, rains, and, near the poles, a continual fall of snow. This would be balanced by a constant flow of the currents of the ocean from each pole towards the equator. We should have an excessive circulation of moisture, but no sunshine, and probably only minute changes in the intensity and appearances of one eternal drizzle or shower. It is plain that this state of things would but ill answer the ends of vegetable and animal life: so that even if the lungs of animals and the leaves of plants were so constructed as to breathe steam instead of air, an atmosphere of unmixed steam would deprive those creatures of most of the other external conditions of their well being. The real state of things which we enjoy, the steam being mixed in our breath and in our sky in a moderate quantity, gives rise to results very different from those which have been described. The machinery by which these results are produced is not a little curious. It is in fact the machinery of the _weather_, and therefore the reader will not be surprised to find it both complex and apparently uncertain in its working. At the same time some of the general principles which govern it seem now to be pretty well made out, and they offer no small evidence of beneficent arrangement. Besides our atmosphere of aqueous vapour, we have another and far larger atmosphere of common air; a _permanently elastic_ fluid, that is, one which is not condensed into a liquid form by pressure or cold, such as it is exposed to in the order of natural events. The pressure of the dry air is about twenty-nine and a half inches of mercury; that of the watery vapour, perhaps, half an inch. Now if we had the earth quite dry, and covered with an atmosphere of dry air, we can trace in a great measure what would be the results, supposing still the equatorial zone to be hot, and the temperature of the surface to decrease perpetually as we advance into higher latitudes. The air at the equator would be rarefied by the heat, and would be perpetually displaced below by the denser portions which belonged to cooler latitudes. We should have a current of air from the equator to the poles in the higher regions of the atmosphere, and at the surface a returning current setting towards the equator to fill up the void so created. Such aerial currents, combined with the rotatory motion of the earth, would produce oblique winds; and we have in fact instances of winds so produced, in the trade winds, which between the tropics blow constantly from the quarters between east and north, and are, we know, balanced by opposite currents in higher regions. The effect of a heated surface of land would be the same as that of the heated zone of the equator, and would attract to it a sea breeze during the day time, a phenomenon, as we also know, of perpetual occurrence. Now a mass of dry air of such a character as this, is by far the dominant part of our atmosphere; and hence carries with it in its motions the thinner and smaller eddies of aqueous vapour. The latter fluid may be considered as permeating and moving in the interstices of the former, as a spring of water flows through a sand rock.[12] The lower current of air is, as has been said, directed towards the equator, and hence it resists the motion of the steam, the tendency of which is in the opposite direction; and prevents or much retards that continual flow of hot vapour into colder regions, by which a constant precipitation would take place in the latter situations. If, in this state of things, the flow of the current of air, which blows from any colder place into a warmer region, be retarded or stopped, the aqueous vapours will now be able to make their way to the colder point, where they will be precipitated in clouds or showers. Thus, in the lower part of the atmosphere, there are tendencies to a current of air in one direction, and a current of vapour in the opposite; and these tendencies exist in the average weather of places situated at a moderate distance from the equator. The air tends from the colder to the warmer parts, the vapour from the warmer to the colder. The various distribution of land and sea, and many other causes make these currents far from simple. But in general the air current predominates, and keeps the skies clear and the moisture dissolved. Occasional and irregular occurrences disturb this predominance; the moisture is then precipitated, the skies are clouded, and the clouds may descend in copious rains. These alternations of fair weather and showers, appear to be much more favourable to vegetable and animal life than any uniform course of weather could have been. To produce this variety, we have two antagonist forces, by the struggle of which such changes occur. Steam and air, two transparent and elastic fluids, expansible by heat, are in many respects and properties very like each other. Yet, the same heat similarly applied to the globe, produces at the surface currents of these fluids, tending in opposite directions. And these currents mix and balance, conspire and interfere, so that our trees and fields have alternately water and sunshine; our fruits and grain are successively developed and matured. Why should such laws of heat and elastic fluids so obtain, and be so combined? Is it not in order that they may be fit for such offices? There is here an arrangement, which no chance could have produced. The details of this apparatus may be beyond our power of tracing; its springs may be out of our sight. Such circumstances do not make it the less a curious and beautiful contrivance: they need not prevent our recognizing the skill and benevolence which we _can_ discover. 2. But we have not yet done with the machinery of the weather. In ascending from the earth’s surface through the atmosphere, we find a remarkable difference in the heat and in the pressure of the air. It becomes much colder, and much lighter; men’s feelings tell them this; and the thermometer and barometer confirm these indications. And here again we find something to remark. In both the simple atmospheres of which we have spoken, the one of air and the one of steam, the property which we have mentioned must exist. In each of them, both the temperature and the tension would diminish in ascending. But they would diminish at very different rates. The temperature, for instance, would decrease much more rapidly for the same height in dry air than in steam. If we begin with a temperature of 80 degrees at the surface, on ascending five thousand feet the steam is still 76½ degrees, the air is only 64½ degrees; at ten thousand feet, the steam is 73 degrees, the air 48½ degrees; at fifteen thousand feet, steam is at 70 degrees, air has fallen below the freezing point to 31½ degrees. Hence these two atmospheres cannot exist together without modifying one another: one must heat or cool the other, so that the coincident parts may be of the same temperature. This accordingly does take place, and this effect influences very greatly the constitution of the atmosphere. For the most part, the steam is compelled to accommodate itself to the temperature of the air, the latter being of much the greater bulk. But if the upper parts of the aqueous vapour be cooled down to the temperature of the air, they will not by any means exert on the lower parts of the same vapour so great a pressure as the gaseous form of these could bear. Hence, there will be a deficiency of moisture in the lower part of the atmosphere, and if water exist there, it will rise by evaporation, the surface feeling an insufficient tension; and there will thus be a fresh supply of vapour upwards. As, however, the upper regions already contain as much as their temperature will support in the state of gas, a precipitation will now take place, and the fluid thus formed will descend till it arrives in a lower region, where the tension and temperature are again adapted to its evaporation. Thus, we can have no equilibrium in such an atmosphere, but a perpetual circulation of vapour between its upper and lower parts. The currents of air which move about in different directions, at different altitudes, will be differently charged with moisture, and as they touch and mingle, lines of cloud are formed, which grow and join, and are spread out in floors, or rolled together in piles. These, again, by an additional accession of humidity, are formed into drops, and descend in showers into the lower regions, and if not evaporated in their fall, reach the surface of the earth. The varying occurrences thus produced, tend to multiply and extend their own variety. The ascending streams of vapour carry with them that _latent heat_ belonging to their gaseous state, which, when they are condensed, they give out as sensible heat. They thus raise the temperature of the upper regions of air, and occasion changes in the pressure and motion of its currents. The clouds, again, by shading the surface of the earth from the sun, diminish the evaporation by which their own substance is supplied, and the heating effects by which currents are caused. Even the mere mechanical effects of the currents of fluid on the distribution of its own pressure, and the dynamical conditions of its motion, are in a high degree abstruse in their principles and complex in their results. It need not be wondered, therefore, if the study of this subject is very difficult and entangled, and our knowledge, after all, very imperfect. In the middle of all this apparent confusion, however, we can see much that we can understand. And, among other things, we may notice some of the consequences of the difference of the laws of temperature followed by steam and by air in going upwards. One important result is that the atmosphere is much drier, near the surface, than it would have been if the laws of density and temperature had been the same for both gases. If this had been so, the air would always have been _saturated_ with vapour. It would have contained as much as the existing temperature could support, and the slightest cooling of any object would have covered it with a watery film like dew. As it is, the air contains much less than its full quantity of vapour: we may often cool an object ten, twenty, or thirty degrees without obtaining a deposition of water upon it, or reaching the _dew-point_, as it is called. To have had such a _dripping_ state of the atmosphere as the former arrangement would have produced, would have been inconvenient, and so far as we can judge, unsuited to vegetables as well as animals. No evaporation from the surface of either could have taken place under such conditions. The sizes and forms of clouds appear to depend on the same circumstance, of the air not being saturated with moisture. And it is seemingly much better that clouds should be comparatively small and well defined, as they are, than that they should fill vast depths of the atmosphere with a thin mist, which would have been the consequence of the imaginary condition of things just mentioned. Here then we have another remarkable exhibition of two laws, in two nearly similar gaseous fluids, producing effects alike in kind, but different in degree, and by the _play_ of their difference giving rise to a new set of results, peculiar in their nature and beneficial in their tendency. The _form_ of the laws of air and of steam with regard to heat might, so far as we can see, have been more similar, or more dissimilar, than it now is: the rate of each law might have had a different amount from its present one, so as quite to alter the relation of the two. By the laws having such forms and such rates as they have, effects are produced, some of which we can distinctly perceive to be beneficial. Perhaps most persons will feel a strong persuasion, that if we understood the operation of these laws more distinctly, we should see still more clearly the beneficial tendency of these effects, and should probably discover others, at present concealed in the apparent perplexity of the subject. 3. From what has been said, we may see, in a general way, both the causes and the effects of _winds_. They arise from any disturbance by temperature, motion, pressure, &c. of the equilibrium of the atmosphere, and are the efforts of nature to restore the balance. Their office in the economy of nature is to carry heat and moisture from one tract to another, and they are the great agents in the distribution of temperature and the changes of weather. Other purposes might easily be ascribed to them in the business of the vegetable and animal kingdoms, and in the arts of human life, of which we shall not here treat. That character in which we now consider them, that of the machinery of atmospheric changes, and thus, immediately or remotely, the instruments of atmospheric influences, cannot well be refused them by any person. 4. There is still one reflexion which ought not to be omitted. All the changes of the weather, even the most violent tempests and torrents of rain, may be considered as oscillations about the mean or average condition belonging to each place. All these oscillations are limited and transient; the storm spends its fury, the inundation passes off, the sky clears, the calmer course of nature succeeds. In the forces which produce this derangement, there is a provision for making it short and moderate. The oscillation stops of itself, like the rolling of a ship, when no longer impelled by the wind. Now, why should this be so? Why should the oscillations, produced by the conflict of so many laws, seemingly quite unconnected with each other, be of this converging and subsiding character? Would it be so under all arrangements? Is it a matter of mechanical necessity that disturbance must end in the restoration of the medium condition? By no means. There may be an utter subversion of the equilibrium. The ship may roll too far, and may _capsize_. The oscillations may go on, becoming larger and larger, till all trace of the original condition is lost; till new forces of inequality and disturbance are brought into play; and disorder and irregularity may succeed, without apparent limit or check in its own nature, like the spread of a conflagration in a city. This is a possibility in any combination of mechanical forces; why does it not happen in the one now before us? By what good fortune are the powers of heat, of water, of steam, of air, the effects of the earth’s annual and diurnal motions, and probably other causes, so adjusted, that through all their struggles the elemental world goes on, upon the whole, so quietly and steadily? Why is the whole fabric of the weather never utterly deranged, its balance lost irrecoverably? Why is there not an eternal conflict, such as the poets imagine to take place in their chaos? “For Hot, Cold, Moist, and Dry, four champions fierce, Strive here for mastery, and to battle bring Their embryon atoms:-- to whom these most adhere, He rules _a moment_: Chaos umpire sits, And by decision more embroils the fray.”--_Par. Lost._ b. ii. A state of things something like that which Milton here seems to have imagined, is, so far as we know, not mechanically impossible. It might have continued to obtain, if Hot and Cold, and Moist and Dry had not been compelled to “run into their places.” It will be hereafter seen, that in the comparatively simple problem of the solar system, a number of very peculiar adjustments were requisite, in order that the system might retain a permanent form, in order that its motions might have their cycles, its perturbations their limits and period. The problem of the continuation of such laws and materials as enter into the constitution of the atmosphere, is one manifestly of much greater complexity, and indeed to us probably of insurmountable difficulty as a mechanical problem. But all that investigation and analogy teach us, tends to show that it will resemble the other problem in the nature of its result; and that certain relations of its data, and of the laws of its elements, are necessary requisites, for securing the stability of its mean condition, and for giving a small and periodical character to its deviations from such a condition. It would then be probable, from this reflection alone, that in determining the quantity and the law and intensity of the forces, of earth, water, air, and heat, the same regard has been shown to the permanency and stability of the terrestrial system, which may be traced in the adjustment of the masses, distances, positions, and motions of the bodies of the celestial machine. This permanency appears to be, of itself, a suitable object of contrivance. The purpose for which the world was made could be answered only by its being preserved. But it has appeared, from the preceding part of this and the former chapter, that this permanence is a permanence of a state of things adapted by the most remarkable and multiplied combinations to the well-being of man, of animals, of vegetables. The adjustments and conditions therefore, beyond the reach of our investigation as they are, by which its permanence is secured, must be conceived as fitted to add, in each of the instances above adduced, to the admiration which the several manifestations of Intelligent Beneficence are calculated to excite. CHAPTER XI. _The Laws of Electricity._ Electricity undoubtedly exists in the atmosphere in most states of the air; but we know very imperfectly the laws of this agent, and are still more ignorant of its atmospheric operation. The present state of science does not therefore enable us to perceive those adaptations of its laws to its uses, which we can discover in those cases where the laws and the uses are both of them more apparent. We can, however, easily make out that electrical agency plays a very considerable part among the clouds, in their usual conditions and changes. This may be easily shown by Franklin’s experiment of the electrical kite. The clouds are sometimes positively, sometimes negatively, charged, and the rain which descends from them offers also indications of one or other kind of electricity. The changes of wind and alterations of the form of the clouds are generally accompanied with changes in these electrical indications. Every one knows that a thunder-cloud is strongly charged with the electric fluid, (if it be a fluid,) and that the stroke of the lightning is an electrical discharge. We may add that it appears, by recent experiments, that a transfer of electricity between plants and the atmosphere is perpetually going on during the process of vegetation. We cannot trace very exactly the precise circumstances, in the occurrences of the atmospheric regions, which depend on the influence of the laws of electricity: but we are tolerably certain, from what has been already noticed, that if these laws did not exist, or were very different from what they now are, the action of the clouds and winds, and the course of vegetation, would also be other than it now is. It is therefore at any rate very probable that electricity has its appointed and important purposes in the economy of the atmosphere. And this being so, we may see a use in the thunder-storm and the stroke of the lightning. These violent events are, with regard to the electricity of the atmosphere, what winds are with regard to heat and moisture. They restore the equilibrium where it has been dissolved, and carry the fluid from places where it is superfluous, to others where it is deficient. We are so constituted, however, that these crises impress almost every one with a feeling of awe. The deep lowering gloom of the thunder-cloud, the overwhelming burst of the explosion, the flash from which the steadiest eye shrinks, and the irresistible arrow of the lightning which no earthly substance can withstand, speak of something fearful, even independently of the personal danger which they may whisper. They convey, far more than any other appearance does, the idea of a superior and mighty power, manifesting displeasure and threatening punishment. Yet we find that this is not the language which they speak to the physical inquirer: he sees these formidable symptoms only as the means or the consequences of good. What office the thunderbolt and the whirlwind may have in the _moral_ world, we cannot here discuss: but certainly _he_ must speculate as far beyond the limits of philosophy as of piety, who pretends to have learnt that there their work has more of evil than of good. In the _natural_ world, these apparently destructive agents are, like all the other movements and appearances of the atmosphere, parts of a great scheme, of which every discoverable purpose is marked with beneficence as well as wisdom. CHAPTER XII. _The Laws of Magnetism._ Magnetism has no very obvious or apparently extensive office in the mechanism of the atmosphere and the earth: but the mention of it may be introduced, because its ascertained relations to the other powers which exist in the system are well suited to show us the connexion subsisting throughout the universe, and to check the suspicion, if any such should arise, that any law of nature is without its use. The parts of creation when these uses are most obscure, are precisely those parts when the laws themselves are least known. When indeed we consider the vast service of which magnetism is to man, by supplying him with that invaluable instrument the mariners’ compass, many persons will require no further evidence of this property being introduced into the frame of things with a worthy purpose. As however, we have hitherto excluded _use in the arts_ from our line of argument, we shall not here make an exception in favour of navigation, and what we shall observe belongs to another view of the subject. Magnetism has been discovered in modern times to have so close a connexion with galvanism, that they may be said to be almost different aspects of the same agent. All the phenomena which we can produce with magnets, we can imitate with coils of galvanic wire. That galvanism exists in the earth, we need no proof. Electricity, which appears to be only galvanism in equilibrium, is there in abundance; and recently, Mr. Fox[13] has shown by experiment that metalliferous veins, as they lie in the earth, exercise a galvanic influence on each other. Something of this kind might have been anticipated; for masses of metal in contact, if they differ in temperature or other circumstances, are known to produce a galvanic current. Hence we have undoubtedly streams of galvanic influence moving along in the earth. Whether or not such causes as these produce the directive power of the magnetic needle, we cannot here pretend to decide; they can hardly fail to affect it. The Aurora Borealis too, probably an electrical phenomenon, is said, under particular circumstances, to agitate the magnetic needle. It is not surprising, therefore, that, if electricity have an important office in the atmosphere, magnetism should exist in the earth. It seems likely, that the magnetic properties of the earth may be collateral results of the existence of the same cause by which electrical agency operates; an agency which, as we have already seen, has important offices in the processes of vegetable life. And thus magnetism belongs to the same system of beneficial contrivance to which electricity has been already traced. We see, however, on this subject very dimly and a very small way. It can hardly be doubted that magnetism has other functions than those we have noticed. CHAPTER XIII. _The Properties of Light with regard to Vegetation._ The illuminating power of light will come under our consideration hereafter. Its agency, with regard to organic life, is too important not to be noticed, though this must be done briefly. Light appears to be as necessary to the health of plants as air of moisture. A plant may, indeed, grow without it, but it does not appear that a species could be so continued. Under such a privation, the parts which are usually green, assume a white colour, as is the case with vegetables grown in a cellar, or protected by a covering for the sake of producing this very effect; thus, celery, is in this manner blanched, or _etiolated_. The part of the process of vegetable life for which light is especially essential, appears to be the functions of the leaves; these are affected by this agent in a very remarkable manner. The moisture which plants imbibe is, by their vital energies, carried to their leaves; and is then brought in contact with the atmosphere, which, besides other ingredients, contains, in general, a portion of carbonic acid. _So long as light is present_, the leaf decomposes the carbonic acid, appropriates the carbon to the formation of its own proper juices, and returns the disengaged oxygen into the atmosphere; thus restoring the atmospheric air to a condition in which it is more fitted than it was before for the support of animal life. The plant thus prepares the support of life for other creatures at the same time that it absorbs its own. The greenness of those members which affect that colour, and the disengagement of oxygen, are the indications that its vital powers are in healthful action: as soon as we remove light from the plant, these indications cease: it has no longer power to imbibe carbon and disengage oxygen, but on the contrary, it gives back some of the carbon already obtained, and robs the atmosphere of oxygen for the purpose of reconverting this into carbonic acid. It cannot well be conceived that such effects of light on vegetables, as we have described, should occur, if that agent, of whatever nature it is, and those organs, had not been adapted to each other. But the subject is here introduced that the reader may the more readily receive the conviction of combining purpose which must arise, on finding that an agent possessing these very peculiar chemical properties, is employed to produce also those effects of illumination, vision, &c., which form the most obvious portion of the properties of light. CHAPTER XIV. _Sound._ Besides the function which air discharges as the great agent in the changes of meteorology and vegetation, it has another office, also of great and extensive importance, as the vehicle of sound. 1. The communication of sound through the air takes place by means of a process altogether different from anything of which we have yet spoken: namely, by the propagation of minute _vibrations_ of the particles from one part of the fluid mass to another, without any local motion of the fluid itself. Perhaps we may most distinctly conceive the kind of effect here spoken of, by comparing it to the motion produced by the wind in a field of standing corn; grassy waves travel visibly over the field, in the direction in which the wind blows, but this appearance of an object moving is delusive. The only real motion is that of the ears of grain, of which each goes and returns, as the stalk stoops and recovers itself. This motion affects _successively_ a line of ears in the direction of the wind, and affects _simultaneously_ all those ears of which the elevation or depression forms one visible wave. The elevations and depressions are propagated in a constant direction, while the parts with which the space is filled only vibrate to and fro. Of exactly such a nature is the propagation of sound through the air. The particles of air go and return through very minute spaces, and this vibratory motion runs through the atmosphere from the sounding body to the ear. Waves, not of elevation and depression, but of condensation and rarefaction, are transmitted; and the sound thus becomes an object of sense to the organ. Another familiar instance of the propagation of vibrations we have in the circles on the surface of smooth water, which diverge from the point where it is touched by a small object, as a drop of rain. In the beginning of a shower, for instance, when the drops come distinct, though frequent, we may see each drop giving rise to a ring, formed of two or three close concentric circles, which grow and spread, leaving the interior of the circles smooth, and gradually reaching parts of the surface more and more distant from their origin. In this instance, it is clearly not a portion of the water which flows onwards; but the disturbance, the rise and fall of the surface which makes the ring-formed waves, passes into wider and wider circles, and thus the undulation is transmitted from its starting-place, to points in all directions on the surface of the fluid. The diffusion of these ring-formed undulations from their centre resembles the diffusion of a sound from the place where it is produced to the points where it is heard. The disturbance, or vibration, by which it is conveyed, travels at the same rate in all directions, and the waves which are propagated are hence of a circular form. They differ, however, from those on the surface of water; for sound is communicated upwards and downwards, and in all intermediate directions, as well as horizontally; hence the waves of sound are spherical, the point where the sound is produced being the centre of the sphere. This diffusion of vibrations in spherical shells of successive condensation and rarefaction, will easily be seen to be different from any local motion of the air, as wind, and to be independent of that. The circles on the surface of water will spread on a river which is flowing, provided it be smooth, as well as on a standing canal. Not only are such undulations propagated almost undisturbed by any local motion of the fluid in which they take place, but also, many may be propagated in the same fluid at the same time, without disturbing each other. We may see this effect on water. When several drops fall near each other, the circles which they produce cross each other, without either of them being lost, and the separate courses of the rings may still be traced. All these consequences, both in water, in air, and in any other fluid, can be very exactly investigated upon mechanical principles, and the greater part of the phenomena can thus be shown to result from the properties of the fluids. There are several remarkable circumstances in the way in which air answers its purpose as the vehicle of sound, of which we will now point out a few. 2. The _loudness_ of sound is such as is convenient for common purposes. The organs of speech can, in the present constitution of the air, produce, without fatigue, such a tone of voice as can be heard with distinctness and with comfort. That any great alteration in this element might be incommodious, we may judge from the difficulties to which persons are subject who are dull of hearing, and from the disagreeable effects of a voice much louder than usual, or so low as to be indistinct. Sounds produced by the human organs, with other kinds of air, are very different from those in our common air. If a man inhale a quantity of hydrogen gas, and then speak, his voice is scarcely audible. The loudness of sounds become smaller in proportion as they come from a greater distance. This enables us to judge of the distance of objects, in some degree at least, by the sounds which proceed from them. Moreover, it is found that we can judge of the position of objects by the ear: and this judgment seems to be formed by comparing the loudness of the impression of the same sound on the two ears and two sides of the head.[14] The loudness of sounds appears to depend on the _extent_ of vibration of the particles of air, and this is determined by the vibrations of the sounding body. 3. The _pitch_, or the _differences of acute and grave_, in sounds, form another important property, and one which fits them for a great part of their purposes. By the succession of different _notes_, we have all the results of melody and harmony in musical sound; and of intonation and modulation of the voice, of accent, cadence, emphasis, expression, passion, in speech. The song of birds, which is one of their principal modes of communication, depends chiefly for its distinctions and its significance upon the combinations of acute and grave. These differences are produced by the different _rapidity_ of vibration of the particles of air. The gravest sound has about eighty vibrations in a second, the most acute about one thousand. Between these limits each sound has a musical character, and from the different relations of the number of vibrations in a second arise all the differences of musical intervals, concords and discords. 4. The _quality_ of sounds is another of their differences. This is the name given to the difference of notes of the same pitch, that is the same note as to acute and grave, when produced by different instruments. If a flute and a violin be in unison, the notes are still quite different sounds. It is this kind of difference which distinguishes the voice of one man from that of another: and it is manifestly therefore one of great consequence; since it connects the voice with the particular person, and is almost necessary in order that language may be a medium of intercourse between men. 5. The _articulate_ character of sounds is for us one of the most important arrangements which exist in the world; for it is by this that they become the interpreters of thought, will and feeling, the means by which a person can convey his wants, his instructions, his promises, his kindness, to others; by which one man can regulate the actions and influence the convictions and judgments of another. It is in virtue of the possibility of shaping air into words, that the imperceptible vibrations which a man produces in the atmosphere, become some of his most important actions; the foundations of the highest moral and social relations; and the condition and instrument of all the advancement and improvement of which he is susceptible. It appears that the differences of articulate sound arise from the different form of the cavity through which the sound is made to proceed immediately _after_ being produced. In the human voice the sound is produced in the larynx, and modified by the cavity of the mouth, and the various organs which surround this cavity. The laws by which articulate sounds are thus produced have not yet been fully developed, but appear to be in the progress of being so. The properties of sounds which have been mentioned, differences of loudness, of pitch, of quality, and articulation, appear to be all requisite in order that sound shall answer its purposes in the economy of animal and of human life. And how was the air made capable of conveying these four differences, at the same time that the organs were made capable of producing them? Surely by a most refined and skilful adaptation, applied with a most comprehensive design. 6. Again; is it by chance that the air and the _ear_ exist together? Did the air produce the organization of the ear? or the ear, independently organized, anticipate the constitution of the atmosphere? Or is not the only intelligible account of the matter, this, that one was made for the other: that there is a mutual adaptation produced by an Intelligence which was acquainted with the properties of both; which adjusted them to each other as we find them adjusted, in order that birds might communicate by song, that men might speak and hear, and that language might play its extraordinary part in its operation upon men’s thoughts, actions, institutions, and fortunes? The vibrations of an elastic fluid like the air, and their properties, follow from the laws of motion; and whether or not these laws of the motion of fluids might in reality have been other than they are, they appear to us inseparably connected with the existence of matter, and as much a thing of necessity as we can conceive any thing in the universe to be. The propagation of such vibrations, therefore, and their properties, we may at present allow to be a necessary part of the constitution of the atmosphere. But what is it that makes these vibrations become sound? How is it that they produce such an effect on our senses, and, through those, on our minds? The vibrations of the air seem to be of themselves no more fitted to produce sound, than to produce smell. We know that such vibrations do not universally produce sound, but only between certain limits. When the vibrations are fewer than eighty in a second, they are perceived as separate throbs, and not as a continued sound; and there is a certain limit of rapidity, beyond which the vibrations become inaudible. This limit is different to different ears, and we are thus assured by one person’s ear that there are vibrations, though to that of another they do not produce sound. How was the human ear adapted so that its perception of vibrations as sounds should fall within these limits?--the very limits within which the vibrations fall, which it most concerns us to perceive: those of the human voice for instance? How nicely are the organs adjusted with regard to the most minute mechanical motions of the elements? CHAPTER XV. _The Atmosphere._ We have considered in succession a number of the properties and operations of the atmosphere, and have found them separately very curious. But an additional interest belongs to the subject when we consider them as combined. The atmosphere under this point of view must appear a contrivance of the most extraordinary kind. To answer any of its purposes, to carry on any of its processes, separately, requires peculiar arrangements and adjustments; to answer, all at once, purposes so varied, to combine without confusion so many different trains, implies powers and attributes which can hardly fail to excite in a high degree our admiration and reverence. If the atmosphere be considered as a vast machine, it is difficult to form any just conception of the profound skill and comprehensiveness of design which it displays. It diffuses and tempers the heat of different climates; for this purpose it performs a circulation occupying the whole range from the pole to the equator; and while it is doing this, it executes many smaller circuits between the sea and the land. At the same time, it is the means of forming clouds and rain, and for this purpose, a perpetual circulation of the watery part of the atmosphere goes on between its lower and upper regions. Besides this complication of circuits, it exercises a more irregular agency, in the occasional winds which blow from all quarters, tending perpetually to restore the equilibrium of heat and moisture. But this incessant and multiplied activity discharges only a part of the functions of the air. It is, moreover, the most important and universal material of the growth and sustenance of plants and animals; and is for this purpose every where present and almost uniform in its quantity. With all its local motion, it has also the office of a medium of communication between intelligent creatures, which office it performs by another set of motions, entirely different both from the circulation and the occasional movements already mentioned; these different kinds of motions not interfering materially with each other: and this last purpose, so remote from the others in its nature, it answers in a manner so perfect and so easy, that we cannot imagine that the object could have been more completely attained, if this had been the sole purpose for which the atmosphere had been created. With all these qualities, this extraordinary part of our terrestrial system is scarcely ever in the way: and when we have occasion to do so, we put forth our hand and push it aside, without being aware of its being near us. We may add, that it is, in addition to all that we have hitherto noticed, a constant source of utility and beauty in its effects on light. Without air we should see nothing, except objects on which the sun’s rays fell, directly or by reflection. It is the atmosphere which converts sunbeams into daylight, and fills the space in which we are with illumination. The contemplation of the atmosphere, as a machine which answers all these purposes, is well suited to impress upon us the strongest conviction of the most refined, far-seeing, and far-ruling contrivance. It seems impossible to suppose that these various properties were so bestowed and so combined, any otherwise than by a beneficent and intelligent Being, able and willing to diffuse organization, life, health, and enjoyment through all parts of the visible world; possessing a fertility of means which no multiplicity of objects could exhaust, and a discrimination of consequences which no complication of conditions could embarrass. CHAPTER XVI. _Light._ Besides the hearing and sound there is another mode by which we become sensible of the impressions of external objects, namely, sight and light. This subject also offers some observations bearing on our present purpose. It has been declared by writers on Natural Theology, that the human eye exhibits such evidence of design and skill in its construction, that no one, who considers it attentively, can resist this impression: nor does this appear to be saying too much. It must, at the same time, be obvious that this construction of the eye could not answer its purposes, except the constitution of light corresponded to it. Light is an element of the most peculiar kind and properties, and such an element can hardly be conceived to have been placed in the universe without a regard to its operation and functions. As the eye is made for light, so light must have been made, at least among other ends, for the eye. 1. We must expect to comprehend imperfectly only the mechanism of the elements. Still, we have endeavoured to show that in some instances the arrangements by which their purposes are effected are, to a certain extent, intelligible. In order to explain, however, in what manner light answers those ends which appear to us its principal ones, we must know something of the nature of light. There have, hitherto, been, among men of science, two prevailing opinions upon this subject: some considering light as consisting in the emission of luminous particles; others accounting for its phenomena by the propagation of vibrations through a highly subtle and elastic _ether_. The former opinion has, till lately, been most generally entertained in this country, having been the hypothesis on which Newton made his calculations; the latter is the one to which most of those persons have been led, who, in recent times, have endeavoured to deduce general conclusions from the newly discovered phenomena of light. Among these persons, the _theory of undulations_ is conceived to be established in nearly the same manner, and almost as certainly, as the doctrine of universal gravitation; namely, by a series of laws inferred from numerous facts, which, proceeding from different sets of phenomena, are found to converge to one common view; and by calculations founded upon the theory, which, indicating new and untried facts, are found to agree exactly with experiment. We cannot here introduce a sketch of the progress by which the phenomena have thus led to the acceptance of the theory of undulations. But this theory appears to have such claims to our assent, that the views which we have to offer with regard to the design exercised in the adaptation, of light to its purposes, will depend on the undulatory theory, so far as they depend on theory at all.[15] 2. The impressions of sight, like those of hearing, differ in intensity and in kind. _Brightness_ and _Colour_ are the principal differences among visible things, as loudness and pitch are among sounds. But there is a singular distinction between these senses in one respect: every object and part of an object seen, is necessarily and inevitably referred to some _position_ in the space before us; and hence visible things have place, magnitude, form, as well as light, shade, and colour. There is nothing analogous to this in the sense of hearing; for though we can, in some approximate degree, _guess_ the situation of the point from which a sound proceeds, this is a secondary process, distinguishable from the perception of the sound itself; whereas we cannot conceive visible things without form and place. The law according to which the sense of vision is thus affected, appears to be this. By the properties of light, the external scene produces, through the transparent parts of the eye, an image or picture exactly resembling the reality, upon the back part of the retina: and each point which we see, is seen in the direction of a line passing from its image on the retina, through the centre of the pupil of the eye.[16] In this manner we perceive by the eye the situation of every point, at the same time that we perceive its existence; and by combining the situations of many points, we have forms and outlines of every sort. That we should receive from the eye this notice of the position of the object as well as of its other visible qualities, appears to be absolutely necessary for our intercourse with the external world; and the faculty of doing so is so intimate a part of our constitution that we cannot conceive ourselves divested of it. Yet in order to imagine ourselves destitute of this faculty, we have only to suppose that the eye should receive its impressions as the ear does, and should apprehend red and green, bright and dark, without placing them side by side; as the ear takes in the different sounds which compose a concert, without attributing them to different parts of space. The peculiar property thus belonging to vision, of perceiving position, is so essential to us, that we may readily believe that some particular provision has been made for its existence. The remarkable mechanism of the eye (precisely resembling that of a _camera obscura_,) by which it produces an image on the nervous web forming its hinder part, seems to have this effect for its main object. And this mechanism necessarily supposes certain corresponding properties in light itself, by means of which such an effect becomes possible. The main properties of light which are concerned in this arrangement, are _reflexion_ and _refraction_: reflexion by which light is reflected and scattered by all objects, and thus comes to the eye from all: and refraction, by which its course is bent, when it passes obliquely out of one transparent medium into another; and by which, consequently, convex transparent substances, such as the cornea and humours of the eye, possess the power of making the light converge to a _focus_ or point; an assemblage of such points forming the images on the retina, which we have mentioned. Reflexion and refraction are therefore the essential and indispensable properties of light; and so far as we can understand, it appears that it was necessary that light should possess such properties, in order that it might form a medium of communication between man and the external world. We may consider its power of passing through transparent media (as air) to be given in order that it may enlighten the earth; its affection of reflexion, for the purpose of making colours visible; and its refraction to be bestowed, that it may enable us to discriminate figure and position, by means of the lenses of the eye. In this manner light may be considered as constituted with a peculiar reference to the eyes of animals, and its leading properties may be looked upon as contrivances or adaptations to fit it for its visual office. And in such a point of view the perfection of the contrivance or adaptation must be allowed to be very remarkable. 3. But besides the properties of reflexion and refraction, the most obvious laws of light, an extraordinary variety of phenomena have lately been discovered, regulated by other laws of the most curious kind, uniting great complexity with great symmetry. We refer to the phenomena of diffraction, polarisation, and periodical colours, produced by crystals and by thin plates. We have, in these facts, a vast mass of properties and laws, offering a subject of study which has been pursued with eminent skill and intelligence. But these properties and laws, so far as has yet been discovered, exert no agency whatever, and have no purpose, in the general economy of nature. Beams of light polarised in contrary directions exhibit the most remarkable differences when they pass through certain crystals, but manifest no discoverable difference in their immediate impression on the eye. We have, therefore, here, a number of laws of light, which we cannot perceive to be established with any design which has a reference to the other parts of the universe. Undoubtedly it is exceedingly possible that these differences of light may operate in some quarter, and in some way, which we cannot detect; and that these laws may have purposes and may answer ends of which we have no suspicion. All the analogy of nature teaches us a lesson of humility, with regard to the reliance we are to place on our discernment and judgment as to such matters. But with our present knowledge, we may observe, that this curious system of phenomena appears to be a collateral result of the mechanism by which the effects of light are produced; and therefore a necessary consequence of the existence of that element of which the offices are so numerous and so beneficent. The new properties of light, and the speculations founded upon them, have led many persons to the belief of the undulatory theory; which, as we have said, is considered by some philosophers as demonstrated. If we adopt this theory, we consider the luminiferous ether to have no local motion; and to produce refraction and reflexion by the operation of its elasticity alone. We must necessarily suppose the tenuity of the ether to be extreme; and if we moreover suppose its tension to be very great, which the vast velocity of light requires us to suppose, the vibrations by which light is propagated will be _transverse_ vibrations, that is the motion to and fro will be athwart the line along which the undulation travels; and from this circumstance all the laws of polarisation necessarily follow. And the properties of transverse vibrations, combined with the properties of vibrations in general, give rise to all the curious and numerous phenomena of colours of which we have spoken. If the vibrations be transverse, they may be resolved into two different planes; this is _polarisation_: if they fall on a medium which has different elasticity in different directions, they will be divided into two sets of vibrations; this is _double refraction_; and so on. Some of the new properties, however, as the fringes of shadows and the colours of thin plates, follow from the undulatory theory, whether the vibrations be transverse or not. It would appear, therefore, that the propagation of light by means of a subtle medium, leads necessarily to the extraordinary collection of properties which have recently been discovered; and, at any rate, its propagation by the transverse vibrations of such a medium does lead inevitably to these results. Leaving it therefore to future times to point out the other reasons (or _uses_ if they exist) of these newly discovered properties of light, in their bearing on other parts of the world, we may venture to say, that if light was to be propagated through transparent media by the undulations of a subtle fluid, these properties must result, as necessarily as the rainbow results from the unequal refrangibility of different colours. This phenomenon and those, appear alike to be the collateral consequences of the law’s impressed on light with a view to its principal offices. Thus the exquisitely beautiful and symmetrical phenomena and laws of polarisation, and of crystalline and other effects, may be looked upon as indications of the delicacy and subtlety of the mechanism by which man, through his visual organs, is put in communication with the external world; is made acquainted with the forms and qualities of objects in the most remote regions of space; and is enabled, in some measure, to determine his position and relation in a universe in which he is but an atom. 4. If we suppose it clearly established that light is produced by the vibrations of an ether, we find considerations offer themselves, similar to those which occurred in the case of sound. The vibrations of this ether affect our organs with the sense of light and colour. Why, or how do they do this? It is only within certain limits that the effect is produced, and these limits are comparatively narrower here than in the case of sound. The whole scale of colour, from violet to crimson, lies between vibrations which are four hundred and fifty-eight million millions, and seven hundred and twenty-seven million millions in a second; a proportion much smaller than the corresponding ratio for perceptible sounds. Why should such vibrations produce perception in the eye, and no others? There must be here some peculiar adaptation of the sensitive powers to these wonderfully minute and condensed mechanical motions. What happens when the vibrations are slower than the red, or quicker than the blue? They do not produce vision: do they produce any effect? Have they any thing to do with heat or with electricity? We cannot tell. The ether must be as susceptible of these vibrations, as of those which produce vision. But the mechanism of the eye is adjusted to this latter kind only; and this precise kind, (whether alone or mixed with others,) proceeds from the sun and from other luminaries, and thus communicates to us the state of the visible universe. The mere material elements then are full of properties which we can understand no otherwise, than as the results of a refined contrivance. CHAPTER XVII. _The Ether._ In what has just been said, we have spoken of light, only with respect to its power of illuminating objects, and conveying the impression of them to the eye. It possesses, however, beyond all doubt, many other qualities. Light is intimately connected with heat, as we see in the case of the sun and of flame; yet it is clear that light and heat are not identical. Light is evidently connected too with electricity and galvanism; and perhaps, through these, with magnetism: it is, as has already been mentioned, indispensably necessary to the healthy discharge of the functions of vegetable life; without it plants cannot duly exercise their vital powers: it manifests also chemical action in various ways. The luminiferous _ether_ then, if we so call the medium in which light is propagated, must possess many other properties besides those mechanical ones on which the illuminating power depends. It must not be merely like a fluid poured into the vacant spaces and interstices of the material world, and exercising no action on objects; it must affect the physical, chemical and vital powers of what it touches. It must be a great and active agent in the work of the universe, as well as an active reporter of what is done by other agents. It must possess a number of complex and refined contrivances and adjustments which we cannot analyze, bearing upon plants and chemical compounds, and the imponderable agents; as well as those laws which we conceive that we have analyzed, by which it is the vehicle of illumination and vision. We have had occasion to point out how complex is the machinery of the atmosphere, and how varied its objects; since, besides being the means of communication as the medium of sound, it has known laws which connect it with heat and moisture; and other laws, in virtue of which it is decomposed by vegetables. It appears, in like manner, that the ether is not only the vehicle of light, but has also laws, at present unknown, which connect it with heat, electricity, and other agencies; and other laws through which it is necessary to vegetables, enabling them to decompose air. All analogy leads us to suppose that if we knew as much of the constitution of the luminiferous ether as we know of the constitution of the atmosphere, we should find it a machine as complex and artificial, as skilfully and admirably constructed. We know at present very little indeed of the construction of this machine. Its _existence_ is, perhaps, satisfactorily made out; in order that we may not interrupt the progress of our argument, we shall refer to other works for the reasonings which appear to lead to this conclusion. But whether heat, electricity, galvanism, magnetism, be fluids; or effects or modifications of fluids; and whether such fluids or _ethers_ be the same with the luminiferous ether, or with each other; are questions of which all or most appear to be at present undecided, and it would be presumptuous and premature here to take one side or the other. The mere fact, however, that there is such an ether, and that it has properties related to other agents, in the way we have suggested, is well calculated to extend our views of the structure of the universe, and of the resources, if we may so speak, of the Power by which it is arranged. The solid and fluid matter of the earth is the most obvious to our senses; over this, and in its cavities, is poured an invisible fluid, the air, by which warmth and life are diffused and fostered, and by which men communicate with men: over and through this again, and reaching, so far as we know, to the utmost bounds of the universe, is spread another most subtle and attenuated fluid, which, by the play of another set of agents, aids the energies of nature, and which, filling all parts of space, is a means of communication with other planets and other systems. There is nothing in all this like any material necessity, compelling the world to be as it is and no otherwise. How should the properties of these three great classes of agents, visible objects, air, and light, so harmonize and assist each other, that order and life should be the result. Without all the three, and all the three constituted in their present manner, and subject to their present laws, living things could not exist. If the earth had no atmosphere, or if the world had no ether, all must be inert and dead. Who constructed these three extraordinary complex pieces of machinery, the earth with its productions, the atmosphere, and the ether? Who fitted them into each other in many parts, and thus made it possible for them to work together? We conceive there can be but one answer; a most wise and good God. CHAPTER XVIII. _Recapitulation._ 1. It has been shown in the preceding chapters that a great number of quantities and laws appear to have been _selected_ in the construction of the universe; and that by the adjustment to each other of the magnitudes and laws thus selected, the constitution of the world is what we find it, and is fitted for the support of vegetables and animals, in a manner in which it could not have been, if the properties and quantities of the elements had been different from what they are. We shall here recapitulate the principal of the laws and magnitudes to which this conclusion has been shown to apply. 1. The Length of the Year, which depends on the force of the attraction of the sun, and its distance from the earth. 2. The Length of the Day. 3. The Mass of the Earth, which depends on its magnitude and density. 4. The Magnitude of the Ocean. 5. The Magnitude of the Atmosphere. 6. The Law and Rate of the Conducting Power of the Earth. 7. The Law and Rate of the Radiating Power of the Earth. 8. The Law and Rate of the Expansion of Water by Heat. 9. The Law and Rate of the Expansion of Water by Cold, below 40 degrees. 10. The Law and Quantity of the Expansion of Water in Freezing. 11. The Quantity of Latent Heat absorbed in Thawing. 12. The Quantity of Latent Heat absorbed in Evaporation. 13. The Law and Rate of Evaporation with regard to Heat. 14. The Law and Rate of the Expansion of Air by Heat. 15. The Quantity of Heat absorbed in the Expansion of Air. 16. The Law and Rate of the Passage of Aqueous Vapour through Air. 17. The Laws of Electricity; its relations to Air and Moisture. 18. The Fluidity, Density, and Elasticity of the Air, by means of which its vibrations produce Sound. 19. The Fluidity, Density, and Elasticity of the Ether, by means of which its vibrations produce Light. 2. These are the _data_, the _elements_, as astronomers call the quantities which determine a planet’s orbit, on which the mere _inorganic_ part of the universe is constructed. To these, the constitution of the organic world is adapted in innumerable points, by laws of which we can trace the results, though we cannot analyze their machinery. Thus, the vital functions of vegetables have periods which correspond to the length of the year, and of the day; their vital powers have forces which correspond to the force of gravity; the sentient faculties of man are such that the vibrations of air (within certain limits,) are perceived as sound, those of ether, as light. And while we are enumerating these correspondencies, we perceive that there are thousands of others, and that we can only select a very small number of those where the relation happens to be most clearly made out or most easily explained. Now, in the list of the mathematical _elements_ of the universe which has just been given, why have we such laws and such quantities as there occur, and no other? For the most part, the data there enumerated are independent of each other, and might be altered separately, so far as the mechanical conditions of the case are concerned. Some of these data probably depend on each other. Thus the latent heat of aqueous vapour is perhaps connected with the difference of the rate of expansion of water and of steam. But all natural philosophers will, probably, agree, that there must be, in this list, a great number of things entirely without any mutual dependence, as the year and the day, the expansion of air and the expansion of steam. There are, therefore, it appears, a number of things which, in the structure of the world, might have been otherwise, and which are what they are in consequence of choice or of chance. We have already seen, in many of the cases separately, how unlike chance every thing looks:--that substances, which might have existed any how, so far as they themselves are concerned, exist exactly in such a manner and measure as they should, to secure the welfare of other things:--that the laws are tempered and fitted together in the only way in which the world could have gone on, according to all that we can conceive of it. This must, therefore, be the work of choice; and if so, it cannot be doubted, of a most wise and benevolent Chooser. 3. The appearance of choice is still further illustrated by the variety as well as the number of the laws selected. The laws are unlike one another. Steam certainly expands at a very different _rate_ from air by the application of heat, probably according to a different _law_: water expands in freezing, but mercury contracts: heat travels in a manner quite different through solids and fluids. Every separate substance has its own density, gravity, cohesion, elasticity, its relations to heat, to electricity, to magnetism; besides all its chemical affinities, which form an endless throng of laws, connecting every one substance in creation with every other, and different for each pair anyhow taken. Nothing can look less like a world formed of atoms operating upon each other according to some universal and inevitable laws, than this does: if such a system of things be conceivable, it cannot be our system. We have, it may be, fifty simple substances in the world; each of which is invested with properties, both of chemical and mechanical action, altogether different from those of any other substance. Every portion, however minute, of any of these, possesses all the properties of the substance. Of each of these substances there is a certain unalterable quantity in the universe; when combined, their compounds exhibit new chemical affinities, new mechanical laws. Who gave these different laws to the different substances? who proportioned the quantity of each? But suppose this done. Suppose these substances in existence; in contact, in due proportion to each other. Is _this_ a world, or at least our world? No more than the mine and the forest are the ship of war and the factory. These elements, with their constitution perfect, and their proportion suitable, are still a mere chaos. They must be put in their places. They must not be where their own properties would place them. They must be made to assume a particular arrangement, or we can have no regular and permanent course of nature. This arrangement must again have additional peculiarities, or we can have no organic portion of the world. The millions of millions of particles which the world contains, must be finished up in as complete a manner, and fitted into their places with as much nicety, as the most delicate wheel or spring in a piece of human machinery. What are the habits of thought to which it can appear possible that this could take place without design, intention, intelligence, purpose, knowledge? In what has just been said, we have spoken only of the constitution of the inorganic part of the universe. The mechanism, if we may so call it, of vegetable and animal life, is so far beyond our comprehension, that though some of the same observations might be applied to it, we do not dwell upon the subject. We know that in these processes also, the mechanical and chemical properties of matter are necessary, but we know too that these alone will not account for the phenomena of life. There is something more than these. The lowest stage of vitality and irritability appears to carry us beyond mechanism, beyond affinity. All that has been said with regard to the exactness of the adjustments, the combination of various means, the tendency to continuance, to preservation, is applicable with additional force to the organic creation, so far as we can perceive the means employed. These, however, belong to a different province of the subject, and must be left to other hands. BOOK II. COSMICAL ARRANGEMENTS. When we turn our attention to the larger portions of the universe, the sun, the planets, and the earth as one of them, the moon and other satellites, the fixed stars and other heavenly bodies;--the views which we obtain concerning their mutual relations, arrangement and movements, are called, as we have already stated, _cosmical_ views. These views will, we conceive, afford us indications of the wisdom and care of the Power by which the objects which we thus consider, were created and are preserved: and we shall now proceed to point out some circumstances in which these attributes may be traced. It has been observed by writers on Natural Theology, that the arguments for the being and perfections of the Creator, drawn from cosmical considerations, labour under some disadvantages when compared with the arguments founded on those provisions and adaptations which more immediately affect the well-being of organized creatures. The structure of the solar system has far less analogy with such machinery as we can construct and comprehend, than we find in the structure of the bodies of animals, or even in the causes of the weather. Moreover, we do not see the immediate bearing of cosmical arrangements on that end which we most readily acknowledge to be useful and desirable, the support and comfort of sentient natures. So that, from both causes, the impression of benevolent design in this case is less striking and pointed than that which results from the examination of some other parts of nature. But in considering the universe, according to the view we have taken, as a collection of _laws_, astronomy, the science which teaches us the laws of the motions of the heavenly bodies, possesses some advantages, among the subjects from which we may seek to learn the character of the government of the world. For our knowledge of the laws of the motions of the planets and satellites is far more complete and exact, far more thorough and satisfactory, than the knowledge which we possess in any other department of Natural Philosophy. Our acquaintance with the laws of the solar system is such, that we can calculate the precise place and motion of most of its parts at any period, past or future, however remote; and we can refer the changes which take place in these circumstances to their proximate cause, the attraction of one mass of matter to another, acting between all the parts of the universe. If, therefore, we trace indications of the Divine care, either in the form of the laws which prevail among the heavenly bodies, or in the arbitrary quantities which such laws involve; (according to the distinction explained in the former part of this work;) we may expect that our examples of such care, though they may be less numerous and obvious, will be more precise than they can be in other subjects, where the laws of facts are imperfectly known, and their causes entirely hid. We trust that this will be found to be the case with regard to some of the examples which we shall adduce. CHAPTER I. _The Structure of the Solar System._ In the cosmical considerations which we have to offer, we shall suppose the general truths concerning the structure of the solar system and of the universe, which have been established by astronomers and mathematicians, to be known to the reader. It is not necessary to go into much detail on this subject. The five planets known to the ancients, Mercury, Venus, Mars, Jupiter, Saturn, revolve round the sun, at different distances, in orbits nearly circular, and nearly in one plane. Between Venus and Mars, our Earth, herself one of the planets, revolves in like manner. Beyond Saturn, Uranus has been discovered describing an orbit of the same kind; and between Mars and Jupiter, four smaller bodies perform their revolutions in orbits somewhat less regular than the rest. These planets are all nearly globular, and all revolve upon their axis. Some of them are accompanied by satellites, or attendant bodies which revolve about them; and these bodies also have their orbits nearly circular, and nearly in the same plane as the others. Saturn’s ring is a solitary example, so far as we know, of such an appendage to a planet. These circular motions of the planets round the sun, and of the satellites round their primary planets, are all kept going by the _attraction_ of the respective central bodies, which restrains the corresponding revolving bodies from flying off. It is perhaps not very easy to make this operation clear to common apprehension. We cannot illustrate it by a comparison with any machine of human contrivance and fabrication: in such machines every thing goes on by contact and impulse: pressure, and force of all kinds, is exercised and transferred from one part to another, by means of a material connexion; by rods, ropes, fluids, gases. In the machinery of the universe there is, so far as we know, no material connexion between the parts which act on each other. In the solar system no part touches or drives another: all the bodies affect each other _at a distance_, as the magnet affects the needle. The production and regulation of such effects, if attempted by our mechanicians, would require great skill and nicety of adjustment; but our artists have not executed any examples of this sort of machinery, by reference to which we can illustrate the arrangements of the solar system. Perhaps the following comparison may serve to explain the kind of adjustments of which we shall have to speak. If there be a wide shallow round basin of smooth marble, and if we take a smooth ball, as a billiard ball or a marble pellet, and throw it along the surface of the inside of the basin, the ball will generally make many revolutions round the inside of the bowl, gradually tending to the bottom in its motion. The gradual diminution of the motion, and consequent tendency of the ball to the bottom of the bowl, arises from the friction; and in order to make the motion correspond to that which takes place through the action of a central force, we must suppose this friction to be got rid of. In this case, the ball, once set a going, would run round the basin for ever, describing either a circle, or various kinds of ovals, according to the way in which it was originally thrown; whether quick or slow, and whether more or less obliquely along the surface. Such a motion would be capable of the same kind of variety, and the same sort of adjustments, as the motion of a body revolving about a larger one by means of a central force. Perhaps the reader may understand what kind of adjustments these are, by supposing such a bowl and ball to be used for a game of skill. If the object of the players be to throw the pellet along the surface of the basin, so that after describing its curved path it shall pass through a small hole in a barrier at some distance from the starting point, it will easily be understood that some nicety in the regulation of the force and direction with which the ball is thrown will be necessary for success. In order to obtain a better image of the solar system, we must suppose the basin to be very large and the pellet very small. And it will easily be understood that as many pellets as there are planets might run round the bowl at the same time with different velocities. Such a contrivance might form a _planetarium_ in which the mimic planets would be regulated by the laws of motion as the real planets are; instead of being carried by wires and wheels, as is done in such machines of the common construction: and in this planetarium the tendency of the planets to the sun is replaced by the tendency of the representative pellets to run down the slope of the bowl. We shall refer again to this basin, thus representing the solar system with its loose planetary balls. CHAPTER II. _The Circular Orbits of the Planets round the Sun._ The orbit which the earth describes round the sun is very nearly a circle: the sun is about one thirtieth nearer to us in winter than in summer. This nearly circular form of the orbit, on a little consideration, will appear to be a remarkable circumstance. Supposing the attraction of a planet towards the sun to exist, if the planet were put in motion in any part of the solar system, it would describe about the sun an orbit _of some kind_; it might be a long oval, or a shorter oval, or an exact circle. But if we suppose the result left to chance, the chances are infinitely against the last mentioned case. There is but one circle; there are an infinite number of ovals. Any original impulse would give some oval, but only one particular impulse, determinate in velocity and direction, will give a circle. If we suppose the planet to be originally _projected_, it must be projected perpendicularly to its distance from the sun, and with a certain precise velocity, in order that the motion may be circular. In the basin to which we have compared the solar system, the adjustment requisite to produce circular motion would require us to project our pellet so that after running half round the surface it should touch a point exactly at an equal distance from the centre, on the other side, passing neither too high nor too low. And the pellet, it may be observed, should be in size only one ten thousandth part of the distance from the centre, to make the dimensions correspond with the cast of the earth’s orbit. If the mark were set up and hit, we should hardly attribute the result to chance. The earth’s orbit, however, is not exactly a circle. The mark is not precisely a single point, but is a space of the breadth of one thirtieth of the distance from the centre. Still this is much too near an agreement with the circle to be considered as the work of chance. The chances were great against the ball passing so nearly at the same distance, for there were twenty-nine equal spaces through which it might have gone, between the mark and the centre, and an indefinite number outside the mark. But it is not the earth’s orbit alone which is nearly a circle: the rest of the planets also approach very nearly to that form: Venus more nearly still than the earth: Jupiter, Saturn, and Uranus have a difference of about one tenth, between their greatest and least distances from the sun: Mars has his extreme distances in the proportion of five to six nearly; and Mercury in the proportion of two to three. The last mentioned case is a considerable deviation, and two of the small planets which lie between Mars and Jupiter, namely Juno and Pallas, exhibit an inequality somewhat greater still; but the smallness of these bodies, and other circumstances, make it probable that there may be particular causes for the exception in their case. The orbits of the satellites of the Earth, of Jupiter and of Saturn, are also nearly circular. Taking the solar system altogether, the regularity of its structure is very remarkable. The diagram which represents the orbits of the planets might have consisted of a number of ovals, narrow and wide in all degrees, intersecting and interfering with each other in all directions. The diagram does consist, as all who have opened a book of astronomy know, of a set of figures which appear at first sight concentric circles, and which are very nearly so; no where approaching to any crossing or interfering, except in the case of the small planets, already noticed as irregular. No one, looking at this common diagram, can believe that the orbits were made to be so nearly circles by chance; any more than he can believe that a target, such as archers are accustomed to shoot at, was painted in concentric circles by the accidental dashes of a brush in the hands of a blind man. The regularity, then, of the solar system excludes the notion of accident in the arrangement of the orbits of the planets. There must have been an express adjustment to produce this circular character of the orbits. The velocity and direction of the motion of each planet must have been subject to some original regulation; or, as it is often expressed, the projectile force must have been accommodated to the centripetal force. This once done, the motion of each planet, taken by itself, would go on for ever, still retaining its circular character, by the laws of motion. If some original cause adjusted the orbits of the planets to their circular form and regular arrangement, we can hardly avoid including in our conception of this cause, the intention and will of a Creating Power. We shall consider this argument more fully in a succeeding chapter; only observing here, that the presiding Intelligence, which has selected and combined the properties of the organic creation, so that they correspond so remarkably with the arbitrary quantities of the system of the universe, may readily be conceived also to have selected the arbitrary velocity and direction of each planet’s motion, so that the adjustment should produce a close approximation to a circular motion. We have argued here only from the _regularity_ of the solar system; from the selection of the single symmetrical case and the rejection of all the unsymmetrical cases. But this subject may be considered in another point of view. The system thus selected is not only regular and symmetrical, but also it is, so far as we can judge, the only one which would answer the purpose of the earth, perhaps of the other planets, as the seat of animal and vegetable life. If the earth’s orbit were more eccentric, as it is called, if for instance the greatest and least distances were as three to one, the inequality of heat at two seasons of the year would be destructive to the existing species of living creatures. A circular, or nearly circular, orbit, is the only case in which we can have a course of seasons such as we have at present, the only case in which the climates of the northern and southern hemispheres are nearly the same; and what is more clearly important, the only case in which the character of the seasons would not vary from century to century. For if the eccentricity of the earth’s orbit were considerable, the difference of heat at different seasons, arising from the different distances of the sun, would be combined with the difference, now the only considerable one, which depends on the position of the earth’s axis. And as by the motion of the _perihelion_, or place of the nearest distance of the earth to the sun, this nearest distance would fall in different ages at different parts of the year, the whole distribution of heat through the year would thus be gradually subverted. The summer and winter of the _tropical_ year, as we have it now, being combined with the heat and cold of the _anomalistic_ year, a period of different length, the difference of the two seasons might sometimes be neutralized altogether, and at other times exaggerated by the accumulation of the inequalities, so as to be intolerable. The circular form of the orbit therefore, which, from its unique character, appears to be chosen with _some_ design, from its effects on the seasons appears to be chosen with this design, so apparent in other parts of creation, of securing the welfare of organic life, by a steadfast and regular order of the solar influence upon the planet. CHAPTER III. _The Stability of the Solar System._ There is a consequence resulting from the actual structure of the solar system, which has been brought to light by the investigations of mathematicians concerning the cause and laws of its motions, and which has an important bearing on our argument. It appears that the arrangement which at present obtains is precisely that which is necessary to secure the _stability_ of the system. This point we must endeavour to explain. If each planet were to revolve round the sun without being affected by the other planets, there would be a certain degree of regularity in its motion; and this regularity would continue for ever. But it appears, by the discovery of the law of universal gravitation, that the planets do not execute their movements in this insulated and independent manner. Each of them is acted on by the attraction of all the rest. The Earth is constantly drawn by Venus, by Mars, by Jupiter, bodies of various magnitudes, perpetually changing their distances and positions with regard to the earth; the Earth in return is perpetually drawing these bodies. What, in the course of time, will be the result of this mutual attraction? All the planets are very small compared with the sun, and therefore the derangement which they produce in the motion of one of their number will be very small in the course of one revolution. But this gives us no security that the derangement may not become very large in the course of many revolutions. The cause acts perpetually, and it has the whole extent of time to work in. Is it not easily conceivable then that in the lapse of ages the derangements of the motions of the planets may accumulate, the orbits may change their form, their mutual distances may be much increased or much diminished? Is it not possible that these changes may go on without limit, and end in the complete subversion and ruin of the system? If, for instance, the result of this mutual gravitation should be to increase considerably the eccentricity of the earth’s orbit, that is to make it a longer and longer oval; or to make the moon approach perpetually nearer and nearer the earth every revolution; it is easy to see that in the one case our year would change its character, as we have noticed in the last section; in the other, our satellite might finally fall to the earth, which must of course bring about a dreadful catastrophe. If the positions of the planetary orbits, with respect to that of the earth, were to change much, the planets might sometimes come very near us, and thus exaggerate the effects of their attraction beyond calculable limits. Under such circumstances, we might have “years of unequal length, and seasons of capricious temperature, planets and moons of portentous size and aspect, glaring and disappearing at uncertain intervals;” tides like deluges, sweeping over whole continents; and, perhaps, the collision of two of the planets, and the consequent destruction of all organization on both of them. Nor is it, on a common examination of the history of the solar system, at all clear that there is no tendency to indefinite derangement. The fact really is, that changes are taking place in the motions of the heavenly bodies, which have gone on progressively from the first dawn of science. The eccentricity of the earth’s orbit has been diminishing from the earliest observations to our times. The moon has been moving quicker and quicker from the time of the first recorded eclipses, and is now in advance, by about four times her own breadth, of what her place would have been if it had not been affected by this acceleration. The obliquity of the ecliptic also is in a state of diminution, and is now about two-fifths of a degree less than it was in the time of Aristotle. Will these changes go on without limit or reaction? If so, we tend by natural causes to a termination of the present system of things: If not, by what adjustment or combination are we secured from such a tendency? Is the system _stable_, and if so, what is the condition on which its stability depends? To answer these questions is far from easy. The mechanical problem which they involve is no less than this;--Having given the directions and velocities with which about thirty bodies are moving at one time, to find their places and motions after any number of ages; each of the bodies, all the while, attracting all the others, and being attracted by them all. It may readily be imagined that this is a problem of extreme complexity, when it is considered that every new _configuration_ or arrangement of the bodies will give rise to a new amount of action on each; and every new action to a new configuration. Accordingly, the mathematical investigation of such questions as the above was too difficult to be attempted in the earlier periods of the progress of Physical Astronomy. Newton did not undertake to demonstrate either the stability or the instability of the system. The decision of this point required a great number of preparatory steps and simplifications, and such progress in the invention and improvement of mathematical methods, as occupied the best mathematicians of Europe for the greater part of last century. But, towards the end of that time, it was shown by Lagrange and Laplace that the arrangements of the solar system are stable: that in the long run, the orbits and motions remain unchanged; and that the changes in the orbits, which take place in shorter periods, never transgress certain very moderate limits. Each orbit undergoes deviations on this side and on that of its average state; but these deviations are never very great, and it finally recovers from them, so that the average is preserved. The planets produce perpetual perturbations in each other’s motions, but these perturbations are not indefinitely progressive, they are periodical: they reach a _maximum_ value and then diminish. The periods which this restoration requires are, for the most part, enormous; not less than thousands, and, in some instances, millions of years; and hence it is, that some of these apparent derangements have been going on in the same direction since the beginning of the history of the world. But the restoration is in the sequel as complete as the derangement; and in the meantime the disturbance never attains a sufficient amount seriously to alter the adaptations of the system.[17] The same examination of the subject by which this is proved, points out also the conditions on which this stability depends. “I have succeeded in demonstrating,” says Laplace, “that whatever be the masses of the planets, in consequence of the fact that they all move in the same direction, in orbits of small eccentricity, and slightly inclined to each other--their secular inequalities are periodical and included within narrow limits; so that the planetary system will only oscillate about a mean state, and will never deviate from it except by a very small quantity. The ellipses of the planets have been, and always will be, nearly circular. The ecliptic will never coincide with the equator, and the entire extent of the variation in its inclination cannot exceed three degrees.” There exists, therefore, it appears, in the solar system, a provision for the permanent regularity of its motions; and this provision is found in the fact that the orbits of the planets are nearly circular, and nearly in the same plane, and the motions all in the same direction, namely, from west to east.[18] Now is it probable that the occurrence of these conditions of stability in the disposition of the solar system is the work of chance? Such a supposition appears to be quite inadmissible. Any one of the orbits might have had any eccentricity.[19] In that of Mercury, where it is much the greatest, it is only one-fifth. How came it to pass that the orbits were not more elongated? A little more or a little less velocity in their original motions would have made them so. They might have had any inclination to the ecliptic from _no_ degrees to 90 degrees. Mercury, which again deviates most widely, is inclined 7¾ degrees, Venus 3¾, Saturn 2¾, Jupiter 1½, Mars 2. How came it that their motions are thus contained within such a narrow strip of the sky? One, or any number of them, might have moved from east to west: none of them does so. And these circumstances, which appear to be, each in particular, requisite for the stability of the system and the smallness of its disturbances, are all found in combination. Does not this imply both clear purpose and profound skill? It is difficult to convey an adequate notion of the extreme complexity of the task thus executed. A number of bodies, all attracting each other, are to be projected in such a manner that their revolutions shall be permanent and stable, their mutual perturbations always small. If we return to the basin with its rolling balls, by which we before represented the solar system, we must complicate with new conditions the trial of skill which we supposed. The problem must now be to project at once seven such balls, all connected by strings which influence their movements, so that each may hit its respective mark. And we must further suppose, that the marks are to be hit after many thousand revolutions of the balls. No one will imagine that this could be done by accident. In fact it is allowed by all those who have considered this subject, that such a coincidence of the existing state with the mechanical requisites of permanency cannot be accidental. Laplace has attempted to calculate the probability that it is not the result of accident. He takes into account, in addition to the motions which we have mentioned, the revolutions of the satellites about their primaries, and of the sun and planets about their axes: and he finds that there is a probability, far higher than that which we have for the greater part of undoubted historical events, that these appearances are not the effect of chance. “We ought, therefore,” he says, “to believe, with at least the same confidence, that a primitive cause has directed the planetary motions.” The solar system is thus, by the confession of all sides, completely different from any thing which we might anticipate from the casual operation of its known laws. The laws of motion are no less obeyed to the letter in the most irregular than in the most regular motions; no less in the varied circuit of the ball which flies round a tennis court, than in the going of a clock; no less in the fantastical jets and leaps which breakers make when they burst in a corner of a rocky shore, than in the steady swell of the open sea. The laws of motion alone will not produce the regularity which we admire in the motions of the heavenly bodies. There must be an original adjustment of the system on which these laws are to act; a selection of the arbitrary quantities which they are to involve; a primitive cause which shall dispose the elements in due relation to each other, in order that regular recurrence may accompany constant change; that perpetual motion may be combined with perpetual stability; that derangements which go on increasing for thousands or for millions of years may finally cure themselves; and that the same laws which lead the planets slightly aside from their paths, may narrowly limit their deviations, and bring them back from their almost imperceptible wanderings. If a man does not deny that any possible peculiarity in the disposition of the planets with regard to the sun could afford evidence of a controlling and ordering purpose, it seems difficult to imagine how he could look for evidence stronger than that which there actually is. Of all the innumerable possible cases of systems, governed by the existing laws of force and motion, that one is selected which alone produces such a steadfast periodicity, such a constant average of circumstances, as are, so far as we can conceive, necessary conditions for the existence of organic and sentient life. And this selection is so far from being an obvious or easily discovered means to this end, that the most profound and attentive consideration of the properties of space and number, with all the appliances and aids we can obtain, are barely sufficient to enable _us_ to see that the end is thus secured, and that it can be secured in no other way. Surely the obvious impression which arises from this view of the subject is, that the solar system, with its adjustments, is the work of an intelligence, who perceives, as self-evident, those truths, to which we attain painfully and slowly, and after all imperfectly; who has employed in every part of creation refined contrivances, which we can only with effort understand; and who, in innumerable instances, exhibits to us what we should look upon as remarkable difficulties remarkably overcome, if it were not that, through the perfection of the provision, the trace of the difficulty is almost obliterated. CHAPTER IV. _The Sun in the Centre._ The next circumstance which we shall notice as indicative of design in the arrangement of the material portions of the solar system, is the position of the sun, the source of light and heat, in the centre of the system. This could hardly have occurred by any thing which we can call chance. Let it be granted, that the law of gravitation is established, and that we have a large mass, with others much smaller in its comparative vicinity. The small bodies may then move round the larger, but this will do nothing towards making it a _sun_ to them. Their motions might take place, the whole system remaining still utterly dark and cold, without day or summer. In order that we may have something more than this blank and dead assemblage of moving clods, the machine must be lighted up and warmed. Some of the advantages of placing the lighting and warming apparatus in the centre are obvious to us. It is in this way only that we could have those regular periodical returns of solar influence, which, as we have seen, are adapted to the constitution of the living creation. And we can easily conceive, that there may be other incongruities in a system with a travelling sun, of which we can only conjecture the nature. No one probably will doubt that the existing system, with the sun in the centre, is better than any one of a different kind would be. Now this lighting and warming by a central sun are something superadded to the mere mechanical arrangements of the universe. There is no apparent reason why the largest mass of gravitating matter should diffuse inexhaustible supplies of light and heat in all directions, while the other masses are merely passive, with respect to such influences. There is no obvious connexion between mass and luminousness, or temperature. No one, probably, will contend that the materials of our system are necessarily luminous or hot. According to the conjectures of astronomers, the heat and light of the sun do not reside in its mass, but in a coating which lies on its surface. If such a coating were fixed there by the force of universal gravitation, how could we avoid having a similar coating on the surface of the earth, and of all the other globes of the system. If light consist in the vibrations of an ether, which we have mentioned as a probable opinion, why has the sun alone the power of exciting such vibrations? If light be the emission of material particles, why does the sun alone emit such particles? Similar questions may be asked, with regard to heat, whatever be the theory we adopt on that subject. Here then we appear to find marks of contrivance. The sun might become, we will suppose, the centre of the motions of the planets by mere mechanical causes: but what caused the centre of their motions to be also the source of those vivifying influences? Allowing that no interposition was requisite to regulate the revolutions of the system, yet observe what a peculiar arrangement in other respects was necessary, in order that these revolutions might produce days and seasons! The machine will move of itself, we may grant: but who constructed the machine, so that its movements might answer the purposes of life? How was the candle placed upon the candlestick? How was the fire deposited on the hearth, so that the comfort and well-being of the family might be secured? Did these too fall into their places by the casual operation of gravity? And, if not, is there not here a clear evidence of intelligent design, of arrangement with a benevolent end? This argument is urged with great force by Newton himself. In his first letter to Bentley, he allows that matter might form itself into masses by the force of attraction. “And thus,” says he, “might the sun and fixed stars be formed, supposing the matter were of a lucid nature. But how the matter should divide itself into two sorts; and that part of it which is fit to compose a shining body should fall down into one mass, and make a sun; and the rest, which is fit to compose an opaque body, should coalesce, not into one great body, like the shining matter, but into many little ones; or if the sun at first were an opake body like the planets, or the planets lucid bodies like the sun, how he alone should be changed into a shining body, whilst all they continue opake; or all they be changed into opake ones, while he continued unchanged: I do not think explicable by mere natural causes, but am forced to ascribe it to the counsel and contrivance of a voluntary Agent.” CHAPTER V. _The Satellites._ 1. A person of ordinary feelings, who, on a fine moonlight night, sees our satellite pouring her mild radiance on field and town, path and moor, will probably not only be disposed to “bless the useful light,” but also to believe that it was “ordained” for that purpose;--that the lesser light was made to rule the night as certainly as the greater light was made to rule the day. Laplace, however, does not assent to this belief. He observes, that “some partisans of final causes have imagined that the moon was given to the earth to afford light during the night:” but he remarks that this cannot be so, for that we are often deprived at the same time of the light of the sun and the moon; and he points out how the moon might have been placed so as to be always “full.” That the light of the moon affords, _to a certain extent_, a supplement to the light of the sun, will hardly be denied. If we take man in a condition in which he uses artificial light scantily only, or not at all, there can be no doubt that the moonlight nights are for him a very important addition to the time of daylight. And as a small proportion only of the whole number of nights are without some portion of moonlight, the fact that sometimes both luminaries are invisible very little diminishes the value of this advantage. Why we have not more moonlight, either in duration or in quantity, is an inquiry which a philosopher could hardly be tempted to enter upon, by any success which has attended previous speculations of a similar nature. Why should not the moon be ten times as large as she is? Why should not the pupil of man’s eye be ten times as large as it is, so as to receive more of the light which does arrive? We do not conceive that our inability to answer the latter question prevents our knowing that the eye was made for seeing: nor does our inability to answer the former, disturb our persuasion that the moon was made to give light upon the earth. Laplace suggests that if the moon had been placed at a certain distance beyond the earth, it would have revolved about the sun in the same time as the earth does, and would have always presented to us a full moon. For this purpose it must have been about four times as far from us as it really is; and would therefore, other things remaining unchanged, have only been _one sixteenth_ as large to the eye as our present full moon. We shall not dwell on the discussion of this suggestion, for the reason just intimated. But we may observe that in such a system as Laplace proposes, it is not yet proved, we believe, that the arrangement would be stable under the influence of the disturbing forces. And we may add that such an arrangement, in which the motion of one body has a _co-ordinate_ reference to two others, as the motion of the moon on this hypothesis would have to the sun and the earth, neither motion being subordinate to the other, is contrary to the whole known analogy of cosmical phenomena, and therefore has no claim to our notice as a subject of discussion. 2. In turning our consideration to the satellites of the other planets of our system, there is one fact which immediately arrests our attention;--the number of such attendant bodies appears to increase as we proceed to planets farther and farther from the sun. Such at least is the general rule. Mercury and Venus, the planets nearest the sun, have no such attendants: the Earth has one. Mars, indeed, who is still farther removed, has none; nor have the minor planets, Juno, Vesta, Ceres, Pallas; so that the rule is only approximately verified. But Jupiter, who is at five times the earth’s distance, has four satellites; and Saturn, who is again at a distance nearly twice as great, has seven, besides that most extraordinary phenomenon his ring, which, for purposes of illumination, is equivalent to many thousand satellites. Of Uranus it is difficult to speak, for his great distance renders it almost impossible to observe the smaller circumstances of his condition. It does not appear at all probable that he has a ring, like Saturn; but he has at least five satellites which are visible to us, at the enormous distance of nine hundred millions of miles; and we believe that the astronomer will hardly deny that he may possibly have thousands of smaller ones circulating about him. But leaving conjecture, and taking only the ascertained cases of Venus, the Earth, Jupiter, and Saturn, we conceive that a person of common understanding will be strongly impressed with the persuasion that the satellites are placed in the system with a view to compensate for the diminished light of the sun at greater distances. The smaller planets, Juno, Vesta, Ceres, and Pallas, differ from the rest in so many ways, and suggest so many conjectures of reasons for such differences, that we should almost expect to find them exceptions to such a rule. Mars is a more obvious exception. Some persons might conjecture from his case, that the arrangement itself, like other useful arrangements, has been brought about by some wider law which we have not yet detected. But whether or not we entertain such a guess, (it can be nothing more,) we see in other parts of creation, so many examples of apparent exceptions to rules, which are afterwards found to be explained, or provided for by particular contrivances, that no one, familiar with such contemplations, will, by one anomaly, be driven from the persuasion that the end which the arrangements of the satellites seem suited to answer is really one of the ends of their creation. CHAPTER VI. _The Stability of the Ocean._ What is meant by the stability of the ocean may perhaps be explained by means of the following illustration. If we suppose the whole globe of the Earth to be composed of water, a sphere of cork, immersed in any part of it, would come to the surface of the water, except it were placed exactly at the centre of the earth; and even if it were the slightest displacement of the cork sphere would end in its rising and floating. This would be the case whatever were the size of the cork sphere, and even if it were so large as to leave comparatively little room for the water; and the result would be nearly the same, if the cork sphere, when in its central position, had on its surface prominences which projected above the surface of the water. Now this brings us to the case in which we have a globe resembling our present earth, composed like it of water and of a solid centre, with islands and continents, but having these solid parts all made of cork. And it appears by the preceding reasoning, that in this case, if there were any disturbance either of the solid or fluid parts, the solid parts would rise from the centre of the watery sphere as far as they could: that is, all the water would run to one side and leave the land on the other. Such an ocean would be in _unstable_ equilibrium. Now a question naturally occurs, is the equilibrium of our present ocean of this unstable kind, or is it stable? The sea, after its most violent agitations, appears to return to its former state of repose; but may not some extraordinary cause produce in it some derangement which may go on increasing till the waters all rush one way, and thus drown the highest mountains? And if we are safe from this danger, what are the conditions by which we are so secured? The illustration which we have employed obviously suggests the answer to this question; namely, that the equilibrium is unstable, so long as the solid parts are of such a kind as to float in the fluid parts; and of course we should expect that the equilibrium will be stable whenever the contrary is the case, that is, when the solid parts of the earth are of greater specific gravity than the sea. A more systematic mathematical calculation has conducted Laplace to a demonstration of this result. The mean specific gravity of the earth appears to be about _five_ times that of water, so that the condition of the stability of the ocean is abundantly fulfilled. And the provision by which this stability is secured was put in force through the action of those causes, whatever they were, which made the density of the solid materials and central parts of the earth greater than the density of the incumbent fluid. When we consider, however, the manner in which the wisdom of the Creator, even in those cases in which his care is most apparent, as in the structure of animals, works by means of intermediate causes and general laws, we shall not be ready to reject all belief of an end in such a case as this, merely because the means are mechanical agencies. Laplace says, “in virtue of gravity, the most dense of the strata of the earth are those nearest to the centre; and thus the mean density exceeds that of the waters which cover it; which suffices to secure the stability of the equilibrium of the seas, and to put a bridle upon the fury of the waves.” This statement, if exact, would not prove that He who subjected the materials of the earth to the action of gravity did not _intend_ to restrain the rage of the waters: but the statement is not true in fact. The lower strata, so far as man has yet examined, are very far from being constantly, or even generally, heavier than the superincumbent ones. And certainly solidification by no means implies a greater density than fluidity: the density of Jupiter is one fourth, that of Saturn less than one seventh, of that of the earth. If an ocean of water were poured into the cavities upon the surface of Saturn, its equilibrium would _not_ be stable. It would leave its bed on one side of the globe; and the planet would finally be composed of one hemisphere of water and one of land. If the Earth had an ocean of a fluid six times as heavy as water, (quicksilver is thirteen times as heavy,) we should have, in like manner, a dry and a fluid hemisphere. Our inland rivers would probably never be able to reach the shores, but would be dried up on their way, like those which run in torrid desarts; perhaps the evaporation from the ocean would never reach the inland mountains, and we should have no rivers at all. Without attempting to imagine the details of such a condition, it is easy to see, that to secure the existence of a different one is an end which is in harmony with all that we see of the preserving care displayed in the rest of creation.[20] CHAPTER VII. _The Nebular Hypothesis._ We have referred to Laplace, as a profound mathematician, who has strongly expressed the opinion, that the arrangement by which the stability of the solar system is secured is not the result of chance; that “_a primitive cause_ has directed the planetary motions.” This author, however, having arrived, as we have done, at this conviction, does not draw from it the conclusion which has appeared to us so irresistible, that “the admirable arrangement of the solar system cannot but be the work of an intelligent and most powerful being.” He quotes these expressions, which are those of Newton, and points at them as instances where that great philosopher had deviated from the method of true philosophy. He himself proposes an hypothesis concerning the nature of the _primitive cause_ of which he conceives the existence to be thus probable: and this hypothesis, on account of the facts which it attempts to combine, the view of the universe which it presents, and the eminence of the person by whom it is propounded, deserves our notice. 1. Laplace conjectures that in the original condition of the solar system, the sun revolved upon his axis, surrounded by an atmosphere which, in virtue of an excessive heat, extended far beyond the orbits of all the planets, the planets as yet having no existence. The heat gradually diminished, and as the solar atmosphere contracted by cooling, the rapidity of its rotation increased by the laws of rotatory motion, and an exterior zone of vapour was detached from the rest, the central attraction being no longer able to overcome the increased centrifugal force. This zone of vapour might in some cases retain its form, as we see it in Saturn’s ring; but more usually the ring of vapour would break into several masses, and these would generally coalesce into one mass, which would revolve about the sun. Such portions of the solar atmosphere, abandoned successively at different distances, would form “planets in the state of vapour.” These planets, it appears from mechanical considerations, would have each its rotatory motion, and as the cooling of the vapour still went on, would each produce a planet, which might have satellites and rings, formed from the planet in the same manner as the planets were formed from the atmosphere of the sun. It may easily be conceived that all the primary motions of a system so produced would be nearly circular, nearly in the plane of the original equator of the solar rotation, and in the direction of that rotation. Reasons are offered also to show that the motions of the satellites thus produced and the motions of rotation of the planets must be in the same direction. And thus it is held that the hypothesis accounts for the most remarkable circumstances in the structure of the solar system: namely, the motions of the planets in the same direction, and almost in the same plane; the motions of the satellites in the same direction as those of the planets; the motions of rotation of these different bodies still in the same direction as the other motions, and in planes not much different; the small eccentricity of the orbits of the planets, upon which condition, along with some of the preceding ones, the stability of the system depends; and the position of the source of light and heat in the centre of the system. It is not necessary for the purpose, nor suitable to the plan of the present treatise, to examine, on physical grounds, the probability of the above hypothesis. It is proposed by its author, with great diffidence, as a conjecture only. We might, therefore, very reasonably put off all discussion of the bearings of this opinion upon our views of the government of the world, till the opinion itself should have assumed a less indistinct and precarious form. It can be no charge against our doctrines, that there is a difficulty in reconciling with them arbitrary guesses and half-formed theories. We shall, however, make a few observations upon this _nebular hypothesis_, as it may be termed. 2. If we grant, for a moment, the hypothesis, it by no means proves that the solar system was formed without the intervention of intelligence and design. It only transfers our view of the skill exercised, and the means employed, to another part of the work. For, how came the sun and its atmosphere to have such materials, such motions, such a constitution, that these consequences followed from their primordial condition? How came the parent vapour thus to be capable of coherence, separation, contraction, solidification? How came the laws of its motion, attraction, repulsion, condensation, to be so fixed, as to lead to a beautiful and harmonious system in the end? How came it to be neither too fluid nor too tenacious, to contract neither too quickly nor too slowly, for the successive formation of the several planetary bodies? How came that substance, which at one time was a luminous vapour, to be at a subsequent period, solids and fluids of many various kinds? What but design and intelligence prepared and tempered this previously existing element, so that it should by its natural changes produce such an orderly system? And if in this way we suppose a planet to be produced, what sort of a body would it be?--something, it may be presumed, resembling a large meteoric stone. How comes this mass to be covered with motion and organization, with life and happiness? What primitive cause stocked it with plants and animals, and produced all the wonderful and subtle contrivances which we find in their structure, all the wide and profound mutual dependencies which we trace in their economy? Was man, with his thought and feeling, his powers and hopes, his will and conscience, also produced as an ultimate result of the condensation of the solar atmosphere? Except we allow a prior purpose and intelligence presiding over this material “primitive cause,” how irreconcilable is it with the evidence which crowds in upon us from every side! 3. In the next place, we may observe concerning this hypothesis, that it carries us back to the beginning of the present system of things; but that it is impossible for our reason to stop at the point thus presented to it. The sun, the earth, the planets, the moons were brought into their present order out of a previous state, and, as is supposed in the theory, by the natural operation of laws. But how came that previous state to exist? We are compelled to suppose that it, in like manner, was educed from a still prior state of things; and this, again, must have been the result of a condition prior still. Nor is it possible for us to find, in the tenets of the nebular hypothesis, any resting place or satisfaction for the mind. The same reasoning faculty, which seeks for the origin of the present system of things, and is capable of assenting to, or dissenting from the hypothesis propounded by Laplace as an answer to this inquiry, is necessarily led to seek, in the same manner, for the origin of any previous system of things, out of which the present may appear to have grown: and must pursue this train of inquiries unremittingly, so long as the answer which it receives describes a mere assemblage of matter and motion; since it would be to contradict the laws of matter and the nature of motion, to suppose such an assemblage to be the _first_ condition. The reflection just stated, may be illustrated by the further consideration of the Nebular Hypothesis. This opinion refers us, for the origin of the solar system, to a sun surrounded with an atmosphere of enormously elevated temperature, revolving and cooling. But as we ascend to a still earlier period, what state of things are we to suppose?--a still higher temperature, a still more diffused atmosphere. Laplace conceives that, in its primitive state, the sun consisted in a diffused luminosity so as to resemble those nebulæ among the fixed stars, which are seen by the aid of the telescope, and which exhibit a nucleus, more or less brilliant, surrounded by a cloudy brightness. “This anterior state was itself preceded by other states, in which the nebulous matter was more and more diffuse, the nucleus being less and less luminous. We arrive,” Laplace says, “in this manner, at a nebulosity so diffuse, that its existence could scarcely be suspected.” “Such is,” he adds, “in fact, the first state of the nebulæ which Herschel carefully observed by means of his powerful telescopes. He traced the progress of condensation, not indeed on one nebula, for this progress can only become perceptible to us in the course of centuries; but in the assemblage of nebulæ; much in the same manner as in a large forest we may trace the growth of trees among the examples of different ages which stand side by side. He saw in the first place the nebulous matter dispersed in patches, in the different parts of the sky. He saw in some of these patches this matter feebly condensed round one or more faint nuclei. In other nebulæ, these nuclei were brighter in proportion to the surrounding nebulosity; when by a further condensation the atmosphere of each nucleus becomes separate from the others, the result is multiple nebulous stars, formed by brilliant nuclei very near each other, and each surrounded by an atmosphere: sometimes the nebulous matter condensing in a uniform manner has produced nebulous systems which are called _planetary_. Finally, a still greater degree of condensation transforms all these nebulous systems into stars. The nebulæ, classed according to this philosophical view, indicate with extreme probability their future transformation into stars, and the anterior nebulous condition of the stars which now exist.” It appears then that the highest point to which this series of conjectures can conduct us, is, “an extremely diffused nebulosity,” attended, we may suppose, by a far higher degree of heat, than that which, at a later period of the hypothetical process, keeps all the materials of our earth and planets in a state of vapour. Now is it not impossible to avoid asking, whence was this light, this heat, this diffusion? How came the laws which such a state implies, to be already in existence? Whether light and heat produce their effects by means of fluid vehicles or otherwise, they have complex and varied laws which indicate the existence of some subtle machinery for their action. When and how was this machinery constructed? Whence too that enormous expansive power which the nebulous matter is supposed to possess? And if, as would seem to be supposed in this doctrine, all the material ingredients of the earth existed in this diffuse nebulosity, either in the state of vapour, or in some state of still greater expansion, whence were they and their properties? how came there to be of each simple substance which now enters into the composition of the universe, just so much and no more? Do we not, far more than ever, require an origin of this origin? an explanation of this explanation? Whatever may be the merits of the opinion as a physical hypothesis, with which we do not here meddle, can it for a moment prevent our looking beyond the hypothesis, to a First Cause, an Intelligent Author, an origin proceeding from free volition, not from material necessity? But again: let us ascend to the highest point of the hypothetical progression: let us suppose the nebulosity diffused throughout all space, so that its course of running into patches is not yet begun. How are we to suppose it distributed? Is it equably diffused in every part? clearly not; for if it were, what should cause it to gather into masses, so various in size, form and arrangement? The separation of the nebulous matter into distinct nebulæ implies necessarily some original inequality of distribution; some determining circumstances in its primitive condition. Whence were these circumstances? this inequality? we are still compelled to seek some ulterior agency and power. Why must the primeval condition be one of change at all? Why should not the nebulous matter be equably diffused throughout space, and continue for ever in its state of equable diffusion, as it must do, from the absence of all cause to determine the time and manner of its separation? why should this nebulous matter grow cooler and cooler? why should it not retain for ever the same degree of heat, whatever heat be? If heat be a fluid, if to cool be to part with this fluid, as many philosophers suppose, what becomes of the fluid heat of the nebulous matter, as the matter cools down? Into what unoccupied region does it find its way? Innumerable questions of the same kind might be asked, and the conclusion to be drawn is, that every new physical theory which we include in our view of the universe, involves us in new difficulties and perplexities, if we try to erect it into an ultimate and final account of the existence and arrangement of the world in which we live. With the evidence of such theories, considered as scientific generalizations of ascertained facts, with their claims to a place in our natural philosophy, we have here nothing to do. But if they are put forwards as a disclosure of the ultimate cause of that which occurs, and as superseding the necessity of looking further or higher; if they claim a place in our Natural Theology, as well as our Natural Philosophy; we conceive that their pretensions will not bear a moment’s examination. Leaving then to other persons and to future ages to decide upon the scientific merits of the nebular hypothesis, we conceive that the final fate of this opinion cannot, in sound reason, affect at all the view which we have been endeavouring to illustrate;--the view of the universe as the work of a wise and good Creator. Let it be supposed that the point to which this hypothesis leads us, is the ultimate point of physical science: that the farthest glimpse we can obtain of the material universe by our natural faculties, shows it to us occupied by a boundless abyss of luminous matter: still we ask, how space came to be thus occupied, how matter came to be thus luminous? If we establish by physical proofs, that the first fact which can be traced in the history of the world, is that “there was light;” we shall still be led, even by our natural reason, to suppose that before this could occur, “God said, let there be light.” CHAPTER VIII. _The Existence of a Resisting Medium in the Solar System._ The question of a _plenum_ and a _vacuum_ was formerly much debated among those who speculated concerning the constitution of the universe; that is, they disputed whether the celestial and terrestrial spaces are absolutely full, each portion being occupied by some matter or other; or whether there are, between and among the material parts of the world, empty spaces free from all matter, however rare. This question was often treated by means of abstract conceptions and _à priori_ reasonings; and was sometimes considered as one in which the result of the struggle between rival systems of philosophy, the Cartesian and Newtonian for instance, was involved. It was conceived by some that the Newtonian doctrine of the motions of the heavenly bodies, according to mechanical laws, required that the space in which they moved should be, absolutely and metaphysically speaking, a vacuum. This, however, is not necessary to the truth of the Newtonian doctrines, and does not appear to have been intended to be asserted by Newton himself. Undoubtedly, according to his theory, the motions of the heavenly bodies were calculated _on the supposition_ that they do move in a space void of any resisting fluid; and the comparison of the places so calculated with the places actually observed, (continued for a long course of years, and tried in innumerable cases,) did not show any difference which implied the existence of a resisting fluid. The Newtonian, therefore, was justified in asserting that _either_ there was no such fluid, _or_ that it was so thin and rarefied, that no phenomenon yet examined by astronomers was capable of betraying its effects. This was all that the Newtonian needed or ought to maintain; for his philosophy, founded altogether upon observation, had nothing to do with abstract possibilities and metaphysical necessities. And in the same manner in which observation and calculation thus showed that there could be none but a very rare medium pervading the solar system, it was left open to observation and calculation to prove that there was such a medium, if any facts could be discovered which offered suitable evidence. Within the last few years, facts have been observed which show, in the opinion of some of the best mathematicians of Europe, that such a very rare medium does really occupy the spaces in which the planets move; and it may be proper and interesting to consider the bearing of this opinion upon the views and arguments which we have had here to present. 1. Reasons might be offered, founded on the universal diffusion of light and on other grounds, for believing that the planetary spaces cannot be entirely free from matter of some kind; and wherever matter is, we should expect resistance. But the facts which have thus led astronomers to the conviction that such a resisting medium really exists, are certain circumstances occurring in the motion of a body revolving round the sun, which is now usually called _Encke’s comet_. This body revolves in a very eccentric or oblong orbit, its greatest or aphelion distance from the sun, and its nearest, or perihelion distance, being in the proportion of more than ten to one. In this respect it agrees with other comets; but its time of revolution about the sun is much less than that of the comets which have excited most notice; for while they appear only at long intervals of years, the body of which we are now speaking returns to its perihelion every twelve hundred and eight days, or in about three years and one-third. Another observable circumstance in this singular body, is its extreme apparent tenuity: it appears as a loose indefinitely formed speck of vapour, through which the stars are visible with no perceptible diminution of their brightness. This body was first seen by Mechain and Messier, in 1786,[21] but they obtained only two observations, whereas three, at least, are requisite to determine the path of a heavenly body. Miss Herschel discovered it again in 1795, and it was observed by several European astronomers. In 1805 it was again seen, and again in 1819. Hitherto it was supposed that the four comets thus observed were all different; Encke, however, showed that the observations could only be explained by considering them as returns of the same revolving body; and by doing this, well merited that his name should be associated with the subject of his discovery. The return of this body in 1822, was calculated beforehand, and observed in New South Wales, the comet being then in the southern part of the heavens; but on comparing the calculated and the observed places, Encke concluded that the observations could not be exactly explained, without supposing a resisting medium. This comet was again generally observed in Europe in 1825 and 1828, and the circumstances of the last appearance were particularly favourable for determining the absolute amount of the retardation arising from the medium, which the other observations had left undetermined. The effect of this retarding influence is, as might be supposed from what has already been said, extremely slight; and would probably not have been perceptible at all, but for the loose texture and small quantity of matter of the revolving body. It will easily be conceived that a body which has perhaps no more solidity or coherence than a cloud of dust, or a wreath of smoke, will have less force to make its way through a fluid medium, however thin, than a more dense and compact body would have. In atmospheric air much rarefied, a bullet might proceed for miles without losing any of its velocity, while such a loose mass as the comet is supposed to be would lose its projectile motion in the space of a few yards. This consideration will account for the circumstance, that the existence of such a medium has been detected by observing the motions of Encke’s comet, though the motions of the heavenly bodies previously observed showed no trace of such an impediment. It will appear perhaps remarkable that a body so light and loose as we have described this comet to be, should revolve about the sun by laws as fixed and certain as those which regulate the motions of those great and solid masses, the Earth and Jupiter. It is however certain from observation, that this comet is acted upon by exactly the same force of solar attraction, as the other bodies of the system; and not only so, but that it also experiences the same kind of disturbing force from the action of the other planets, which they exercise upon each other. The effect of all these causes has been calculated with great care and labour; and the result has been an agreement with observation sufficiently close to show that these causes really act, but at the same time a _residual phenomenon_ (as Sir J. Herschel expresses it) has come to light: and from this has been collected the inference of a resisting medium. This medium produces a very small effect upon the motion of the comet, as will easily be supposed from what has been said. By Encke’s calculation, it appears that the effect of the resistance, supposing the comet to move in the earth’s orbit, would be about an eight hundred and fiftieth of the sun’s force on the body. The effect of such resistance may appear, at first sight, paradoxical; it would be to make the comet _move_ more slowly, but _perform its revolutions_ more quickly. This, however, will perhaps be understood if it be considered that by _moving_ more slowly the comet will be more rapidly _drawn_ towards the centre, and that in this way a revolution will be described by a shorter path than it was before. It appears that in getting round the sun, the comet gains more in this way than it loses by the diminution of its velocity. The case is much like that of a stone thrown in the air; the stone moves more slowly than it would do if there were no air; but yet it comes to the earth _sooner_ than it would do on that supposition. It appears that the effect of the resistance of the ethereal medium, from the first discovery of the comet up to the present time, has been to diminish the time of revolution by about two days: and the comet is ten days in advance of the place which it would have reached, if there had been no resistance. 2. The same medium which is thus shown to produce an effect upon Encke’s comet, must also act upon the planets which move through the same spaces. The effect upon the planets, however, must be very much smaller than the effect upon the comet, in consequence of their greater quantity of matter. It is not easy to assign any probable value, or even any certain limit, to the effect of the resisting medium upon the planets. We are entirely ignorant of the comparative mass of the comet, and of any of the planets; and hence, cannot make any calculation founded on such a comparison. Newton has endeavoured to show how small the resistance of the medium must be, if it exist.[22] The result of his calculation is, that if we take the density of the medium to be that which our air will have at two hundred miles from the earth’s surface, supposing the law of diminution of density to go on unaltered, and if we suppose Jupiter to move in such a medium, he would in a million years lose less than a millionth part of his velocity. If a planet, revolving about the sun, were to lose any portion of its velocity by the effect of resistance, it would be drawn proportionally nearer the sun, the tendency towards the centre being no longer sufficiently counteracted by that centrifugal force which arises from the body’s velocity. And if the resistance were to continue to act, the body would be drawn perpetually nearer and nearer to the centre, and would describe its revolutions quicker and quicker, till at last it would reach the central body, and the system would cease to be a system. This result is true, however small be the velocity lost by resistance; the only difference being, that when the resistance is small, the time requisite to extinguish the whole motion will be proportionally longer. In all cases the times which come under our consideration in problems of this kind, are enormous to common apprehension. Thus Encke’s comet, according to the results of the observations already made, will lose, in ten revolutions, or thirty-three years, less than one thousandth of its velocity: and if this law were to continue, the velocity would not be reduced to one-half its present value in less than seven thousand revolutions or twenty-three thousand years. If Jupiter were to lose one-millionth of his velocity in a million years, (which, as has been seen, is far more than can be considered in any way probable,) he would require seventy millions of years to lose one-thousandth of the velocity; and a period seven hundred times as long to reduce the velocity to one-half. These are periods of time which quite overwhelm the imagination; and it is not pretended that the calculations are made with any pretensions to accuracy. But at the same time it is beyond doubt that though the intervals of time thus assigned to these changes are highly vague and uncertain, the changes themselves must, sooner or later, take place, in consequence of the existence of the resisting medium. Since there is such a retarding force perpetually acting, however slight it be, it must in the end destroy all the celestial motions. It may be millions of millions of years before the earth’s retardation may perceptibly affect the apparent motion of the sun; but still the day will come (if the same Providence which formed the system, should permit it to continue so long) when this cause will entirely change the length of our year and the course of our seasons, and finally stop the earth’s motion round the sun altogether. The smallness of the resistance, however small we choose to suppose it, does not allow us to escape this certainty. There is a resisting medium; and, therefore, the movements of the solar system cannot go on for ever. The moment such a fluid is ascertained to exist, the eternity of the movements of the planets becomes as impossible as a perpetual motion on the earth. 3. The vast periods which are brought under our consideration in tracing the effects of the resisting medium, harmonize with all that we learn of the constitution of the universe from other sources. Millions, and millions of millions of years are expressions that at first sight appear fitted only to overwhelm and confound all our powers of thought; and such numbers are no doubt beyond the limits of any thing which we distinctly conceive. But our powers of conception are suited rather to the wants and uses of common life, than to a complete survey of the universe. It is in no way unlikely that the whole duration of the solar system should be a period immeasurably great in our eyes, though demonstrably finite. Such enormous numbers have been brought under our notice by all the advances we have made in our knowledge of nature. The smallness of the objects detected by the microscope and of their parts;--the multitude of the stars which the best telescopes of modern times have discovered in the sky;--the duration assigned to the globe of the earth by geological investigation;--all these results require for their probable expression, numbers, which so far as we see, are on the same gigantic scale as the number of years in which the solar system will become entirely deranged. Such calculations depend in some degree on our relation to the vast aggregate of the works of our Creator; and no person who is accustomed to meditate on these subjects will be surprised that the numbers which such an occasion requires should oppress our comprehension. No one who has dwelt on the thought of a universal Creator and Preserver, will be surprised to find the conviction forced upon the mind by every new train of speculation, that viewed in reference to Him, our space is a point, our time a moment, our millions a handful, our permanence a quick decay. Our knowledge of the vast periods, both geological and astronomical, of which we have spoken, is most slight. It is in fact little more than that such periods exist; that the surface of the earth has, at wide intervals of time, undergone great changes in the disposition of land and water, and in the forms of animal life; and that the motions of the heavenly bodies round the sun are affected, though with inconceivable slowness, by a force which must end by deranging them altogether. It would therefore be rash to endeavour to establish any analogy between the periods thus disclosed; but we may observe that they _agree_ in this, that they reduce all things to the general rule of _finite duration_. As all the geological states of which we find evidence in the present state of the earth, have had their termination, so also the astronomical conditions under which the revolutions of the earth itself proceed, involve the necessity of a future cessation of these revolutions. The contemplative person may well be struck by this universal law of the creation. We are in the habit sometimes of contrasting the transient destiny of man with the permanence of the forests, the mountains, the ocean,--with the unwearied circuit of the sun. But this contrast is a delusion of our own imagination; the difference is after all but one of degree. The forest tree endures for its centuries and then decays; the mountains crumble and change, and perhaps subside in some convulsion of nature; the sea retires, and the shore ceases to resound with the “everlasting” voice of the ocean: such reflections have already crowded upon the mind of the geologist; and it now appears that the courses of the heavens themselves are not exempt from the universal law of decay; that not only the rocks and the mountains, but the sun and the moon have the sentence “to end” stamped upon their foreheads. They enjoy no privilege beyond man except a longer respite. The ephemeron perishes in an hour; man endures for his three score years and ten; an empire, a nation, numbers its centuries, it may be its thousands of years; the continents and islands which its dominion includes have perhaps their date, as those which preceded them have had; and the very revolutions of the sky by which centuries are numbered will at last languish and stand still. To dwell on the moral and religious reflections suggested by this train of thought is not to our present purpose; but we may observe that it introduces a _homogeneity_, so to speak, into the government of the universe. Perpetual change, perpetual progression, increase and diminution, appear to be the rules of the material world, and to prevail without exception. The smaller portions of matter which we have near us, and the larger, which appear as luminaries at a vast distance, different as they are in our mode of conceiving them, obey the same laws of motion; and these laws produce the same results; in both cases motion is perpetually destroyed, except it be repaired by some living power; in both cases the relative rest of the parts of a material system is the conclusion to which its motion tends. 4. It may perhaps appear to some, that this acknowledgment of the tendency of the system to derangement through the action of a resisting medium is inconsistent with the argument which we have drawn in a previous chapter, from the provisions for its stability. In reality, however, the two views are in perfect agreement, so far as our purpose is concerned. The main point which we had to urge, in the consideration of the stability of the system, was, not that it is constructed to last for ever, but that while it lasts, the deviations from its mean condition are very small. It is this property which fits the world for its uses. To maintain either the past or the future eternity of the world, does not appear consistent with physical principles, as it certainly does not fall in with the convictions of the religious man, in whatever way obtained. We conceive that this state of things has had a beginning; we conceive that it will have an end. But in the mean time we find it fitted, by a number of remarkable arrangements, to be the habitation of living creatures. The conditions which secure the stability, and the smallness of the perturbations of the system, are among these provisions. If the eccentricity of the orbit of Venus, or of Jupiter, were much greater than it is, not only might some of the planets, at the close of ages, fall into the sun or fly off into infinite space, but also, in the intermediate time, the earth’s orbit might become much more eccentric; the course of the seasons and the average of temperature might vary from what they now are, so as to injure or destroy the whole organic creation. By certain original arrangements these destructive oscillations are prevented. So long as the bodies continue to revolve, their orbits will not be much different from what they now are. And this result is not affected by the action of the resisting medium. Such a medium cannot increase the small eccentricities of the orbits. The range of the periodical oscillations of heat and cold will not be extended by the mechanical effect of the medium, nor would be, even if its density were incomparably greater than it is. The resisting medium therefore does not at all counteract that which is most important in the provision for the permanency of the solar system. If the stability of the system had not been secured by the adjustments which we described in a former chapter, the course of the seasons might have been disturbed to an injurious or even destructive extent in the course of a few centuries, or even within the limits of one generation; by the effect of the resisting medium, the order of nature remains unchanged for a period, compared with which the known duration of the human race is insignificant. But, it may be objected, the effect of the medium must be ultimately to affect, the duration of the earth’s revolution round the sun, and thus to derange those adaptations which depend on the length of the year. And, without question, if we permit ourselves to look forward to that inconceivably distant period at which the effect of the medium will become sensible, this must be allowed to be true, as has been already stated. Millions, and probably millions of millions, of years express inadequately the distance of time at which this cause would produce a serious effect. That the machine of the universe is so constructed that it may answer its purposes for such a period, is surely sufficient proof of the skill of its workmanship, and of the reality of its purpose: and those persons, probably, who are best convinced that it is the work of a wise and good Creator, will be least disposed to consider the system as imperfect, because in its present condition it is not fitted for eternity. 5. The doctrine of a Resisting Medium leads us towards a point which the Nebular Hypothesis assumes;--a _beginning_ of the present order of things. There must have been a commencement of the motions now going on in the solar system. Since these motions, when once begun, would be deranged and destroyed in a period which, however large, is yet finite, it is obvious we cannot carry their origin indefinitely backwards in a range of past duration. There is a period in which these revolutions, whenever they had begun, would have brought the revolving bodies into contact with the central mass; and this period has in our system not yet elapsed. The watch is still going, and therefore it must have been wound up within a limited time. The solar system, at this its beginning, must have been arranged and put in motion by some cause. If we suppose this cause to operate by means of the configurations and the properties of previously existing matter, these configurations must have resulted from some still previous cause, these properties must have produced some previous effects. We are thus led to a condition still earlier than the assumed beginning;--to an origin of the original state of the universe; and in this manner we are carried perpetually further and further back, through a labyrinth of mechanical causation, without any possibility of finding any thing in which the mind can acquiesce or rest, till we admit “a First Cause which is not mechanical.” Thus the argument which was before urged against those in particular, who put forwards the Nebular Hypothesis in opposition to the admission of an Intelligent Creator, offers itself again, as cogent in itself, when we adopt the opinion of a resisting medium, for which the physical proofs have been found to be so strong. The argument is indeed forced upon our minds, whatever view we take of the past history of the universe. Some have endeavoured to evade its force by maintaining that the world as it now exists has existed from eternity. They assert that the present order of things, or an order of things in some way resembling the present, produced by the same causes, governed by the same laws, has prevailed through an infinite succession of past ages. We shall not dwell upon any objections to this tenet which might be drawn from our own conceptions, or from what may be called metaphysical sources. Nor shall we refer to the various considerations which history, geology, and astronomical records supply, and which tend to show, not only that the past duration of the present course of things is finite, but that it is short, compared with such periods as we have had to speak of. But we may observe, that the doctrine of a resisting medium once established, makes this imagination untenable; compels us to go back to the origin, not only of the present course of the world, not only of the earth, but of the solar system itself; and thus sets us forth upon that path of research into the series of past causation, where we obtain no answer of which the meaning corresponds to our questions, till we rest in the conclusion of a most provident and most powerful Creating Intelligence. It is related of Epicurus that when a boy, reading with his preceptor these verses of Hesiod, Ητοι μεν πρωτιζα Χαος γενετ’, αυταρ επειτα Γαι’ ευρυζερνος παντων εδος ασφαλες αιει Αθανατων, Eldest of beings, Chaos first arose, Thence Earth wide stretched, the steadfast seat of all The Immortals, the young scholar first betrayed his inquisitive genius by asking “And chaos whence?” When in his riper years he had persuaded himself that this question was sufficiently answered by saying that chaos arose from the concourse of atoms, it is strange that the same inquisitive spirit did not again suggest the question “and atoms whence?” And it is clear that however often the question “whence?” had been answered, it would still start up as at first. Nor could it suffice as an answer to say, that earth, chaos, atoms, were portions of a series of changes which went back to eternity. The preceptor of Epicurus informed him, that to be satisfied on the subject of his inquiry, he must have recourse to the philosophers. If the young speculator had been told that chaos (if chaos indeed preceded the present order) was produced by an Eternal Being, in whom resided purpose and will, he would have received a suggestion which, duly matured by subsequent contemplation, might have led him to a philosophy far more satisfactory than the material scheme can ever be, to one who looks, either abroad into the universe, or within into his own bosom. CHAPTER IX. _Mechanical Laws._ In the preceding observations we have supposed the laws, by which different kinds of matter act and are acted upon, to be already in existence; and have endeavoured to point out evidences of design and adaptation, displayed in the selection and arrangement of these materials of the universe. These materials are, it has appeared, supplied in such measures and disposed in such forms, that by means of their properties and laws the business of the world goes on harmoniously and beneficially. But a further question occurs: how came matter to have such properties and laws? Are these also to be considered as things of selection and institution? And if so, can we trace the reasons why the laws were established in their present form; why the properties which matter actually possesses were established and bestowed and bestowed upon it? We have already attempted, in a previous part of this work, to point out some of the advantages which are secured by the existing laws of heat, light and moisture. Can we, in the same manner, point out the benefits which arise from the present constitution of those laws of matter which are mainly concerned in the production of cosmical phenomena? It will readily be perceived that the discussion of this point must necessarily require some effort of abstract thought. The laws and properties of which we have here to speak, the laws of motion and the universal properties of matter, are so closely interwoven with our conceptions of the external world, that we have great difficulty in conceiving them not to exist, or to exist other than they are. When we press or lift a stone, we can hardly imagine that it could, by possibility, do otherwise than resist our effort by its hardness and by its heaviness, qualities so familiar to us: when we throw it, it seems inevitable that its motion should depend on the impulse we give, just as we find that it invariably does. Nor is it easy to say how far it is really possible to suppose the fundamental attributes of matter to be different from what they are. If we, in our thoughts, attempt to divest matter of its powers of resisting and moving, it ceases to be matter, according to our conceptions, and we can no longer reason upon it with any distinctness. And yet it is certain that we can conceive the laws of hardness and weight and motion to be quite different from what they are, and can point out some of the consequences which would result from such difference. The properties of matter, even the most fundamental and universal ones, do not obtain by any absolute necessity, resembling that which belongs to the properties of geometry. A line touching a circle is _necessarily_ perpendicular to a line drawn to the centre through the point touched; for it may be shown that the contrary involves a contradiction. But there is no contradiction in supposing that a body’s motion should naturally diminish, or that its weight should increase in removing further from the earth’s centre. Thus the properties of matter and the laws of motion are what we find them, not by virtue of any internal necessity which we can understand. The study of such laws and properties may therefore disclose to us the character of that external agency by which we conceive them to have been determined to be what they are; and this must be the same agency by which all other parts of the constitution of the universe were appointed and ordered. But we can hardly expect, with regard to such subjects, that we shall be able to obtain any complete or adequate view of the reasons why these general laws are so selected, and so established. These laws are the universal basis of all operations which go on, at any moment, in every part of space, with regard to every particle of matter, organic and inorganic. All other laws and properties must have a reference to these, and must be influenced by them; both such as men have already discovered, and the far greater number which remain still unknown. The general economy and mutual relations of all parts of the universe, must be subordinate to the laws of motion and matter of which we here speak. We can easily suppose that the various processes of nature, and the dependencies of various creatures, are affected in the most comprehensive manner by these laws;--are simplified by _their_ simplicity, made consistent by _their_ universality; rendered regular by _their_ symmetry. We can easily suppose that in this way there may be the most profound and admirable reasons for the existence of the present universal properties of matter, which we cannot apprehend in consequence of the limited nature of our knowledge, and of our faculties. For, compared with the whole extent of the universe, the whole aggregate of things and relations and connexions which exist in it, our knowledge is most narrow and partial, most shallow and superficial. We cannot suppose, therefore, that the reasons which we discover for the present form of the laws of nature go nearly to the full extent, or to the bottom of the reasons, which a more complete and profound insight would enable us to perceive. To do justice to such reasons, would require nothing less than a perfect acquaintance with the whole constitution of every part of creation; a knowledge which man has not, and, so far as we can conceive, never can have. We are certain, therefore, that our views, with regard to this part of our subject, must be imperfect and limited. Yet still man has _some_ knowledge with regard to various portions of nature; and with regard to those most general and comparatively simple facts to which we now refer, his knowledge is more comprehensive, and goes deeper than it does in any other province. We conceive, therefore, that we shall not be engaged in any rash or presumptuous attempt, if we endeavour to point out some of the advantages which are secured by the present constitution of some of the general mechanical laws of nature; and to suggest the persuasion of that purpose and wise design, which the selection of such laws will thus appear to imply. CHAPTER X. _The Law of Gravitation._ We shall proceed to make a few observations on the Law of Gravity, in virtue of which the motions of planets about the sun, and of satellites about their planets take place; and by which also are produced the fall downwards of all bodies within our reach, and the pressure which they exert upon their supports when at rest. The identification of the latter forces with the former, and the discovery of the single law by which these forces are every where regulated, was the great discovery of Newton: and we wish to make it appear that this law is established by an intelligent and comprehensive selection. The law of the sun’s attraction upon the planets is, that this attraction varies _inversely_ as the square of the distance; that is, it decreases as that square increases. If we take three points or planets of the solar system, the distances of which from the sun are in proper proportion one, two, three; the attractive force which the sun at these distances exercises, is as one, one-fourth, and one-ninth respectively. In the smaller variations of distance which occur in the elliptical motion of one planet, the variations of the force follow the same law. Moreover, not only does the sun attract the planets, but they attract each other according to the same law; the tendency to the earth which makes bodies heavy, is one of the effects of this law: and all these effects of the attractions of large masses may be traced to the attractions of the particles of which they are composed; so that the final generalization, including all the derivative laws, is, that every particle of matter in the universe attracts every other, according to the law of the inverse square of the distance. Such is the law of universal gravitation. Now, the question is, why do either the attractions of masses, or those of their component particles, follow this law of the inverse square of the distance rather than any other? When the distance becomes one, two, and three, why should not the force also become one, two, and three?--or if it must be weaker at points more remote from the attracting body, why should it not be one, a half, a third? or one, an eighth, a twenty-seventh? Such law’s could easily be expressed mathematically, and their consequences calculated. Can any reason be assigned why the law which we find in operation _must_ obtain? Can any be assigned why it _should_ obtain? The answer to this is, that no reason, at all satisfactory, can be given why such a law must, of necessity, be what it is; but that very strong reasons can be pointed out why, for the beauty and advantage of the system, the present one is better than others. We will point out some of these reasons. 1. In the first place, the system could not have subsisted, if the force had followed a _direct_ instead of an inverse law, with respect to the distance; that is, if it had increased when the distance increased. It has been sometimes said, that “all direct laws of force are excluded on account of the danger from perturbing forces;”[23] that if the planets had pulled at this earth, the harder the further off they were, they would have dragged it entirely out of its course. This is not an exact statement of what would happen: if the force were to be simply in the direct ratio of the distance, any number of planets might revolve in the most regular and orderly manner. Their mutual effects, which we may call perturbations if we please, would be considerable; but these perturbations would be so combined with the unperturbed motion, as to produce a new motion not less regular than the other. This curious result would follow, that every body in the system would describe, or seem to describe, about every other, an exact elliptical orbit; and that the times of the revolution of every body in its orbit would be all equal. This is proved by Newton, in the sixty-fourth proposition of the Principia. There would be nothing to prevent all the planets, on this supposition, from moving round the sun in orbits exactly circular, or nearly circular, according to the mode in which they were set in motion. But though the perturbations of the system would not make this law inadmissible, there are other circumstances which would do so. Under this law, the gravity of bodies at the earth’s surface would cease to exist. Nothing would fall or weigh downwards. The greater action of the distant sun and planets would exactly neutralize the gravity of the earth: a ball thrown from the hand, however gently, would immediately become a satellite of the earth, and would for the future accompany it in its course, revolving about it in the space of one year. All terrestrial things would float about with no principle of coherence or stability: they would obey the general law of the system, but would acknowledge no particular relation to the earth. We can hardly pretend to judge of the abstract possibility of such a system of things; but it is clear that it could not exist without an utter subversion of all that we can conceive of the economy and structure of the world which we inhabit. With any other direct law of force, we should in like manner lose gravity, without gaining the theoretical regularity of the planetary motions which we have described in the case just considered. 2. Among _inverse_ laws of the distance, (that is, those according to which the force diminishes as the distance from the origin of force increases,) all which diminish the central force faster than the _cube_ of the distance increases are inadmissible, because they are incompatible with the permanent revolution of a planet. Under such laws it would follow, that a planet would describe a spiral line about the sun, and would either approach nearer and nearer to him perpetually, or perpetually go further and further off: nearly as a stone at the end of a string, when the string is whirled round, and is allowed to wrap round the hand, or to unwrap from it, approaches to or recedes from the hand. If we endeavour to compare the law of the inverse square of the distance, which really regulates the central force, with other laws, not obviously inadmissible, as for instance, the inverse simple ratio of the distance, a considerable quantity of calculation is found to be necessary in order to trace the results, and especially the perturbations in the two cases. The perturbations in the supposed case have not been calculated; such a calculation being a process so long and laborious that it is never gone through, except for the purpose of comparing the results of theory with those of observation, as we can do with regard to the law of inverse square. We can only say, therefore, that the stability of the system, and the moderate limits of the perturbations, which we know to be secured by the existing law, would not, so far as we know, be obtained by any different law. Without going into further examination of the subject, we may observe that there are some circumstances in which the present system has a manifest superiority in its simplicity over the condition which would have belonged to it if the force had followed any other law. Thus, with the present law of gravitation the planets revolve, returning perpetually on the same track, very nearly. The earth describes an oval, in consequence of which motion she is nearer to the sun in our winter than in our summer by about one-thirtieth part of the whole distance. And, as the matter now is, the nearest approach to the sun, and the farthest recess from him, occur always at the same points of the orbit. There is indeed a slight alteration in these points arising from disturbing forces, but this is hardly sensible in the course of several ages. Now if the force had followed any other law, we should have had the earth running perpetually on a new track. The greatest and least distances would have occurred at different parts in every successive revolution. The orbit would have perpetually intersected and been interlaced with the path described in former revolutions; and the simplicity and regularity which characterizes the present motion would have been quite wanting. 3. Another peculiar point of simplicity in the present law of mutual attraction is this: that it makes the law of attraction for spherical masses the same as for single particles. If particles attract with forces which are inversely as the square of the distance, spheres composed of such particles, will exert a force which follows the same law. In this character the present law is singular, among all possible laws, excepting that of the direct distance which we have already discussed. If the law of the gravitation of particles had been that of the inverse simple distance, the attraction of a sphere would have been expressed by a complex series of mathematical expressions, each representing a simple law. It is truly remarkable that the law of the inverse square of the distance, which appears to be selected as that of the _masses_ of the system, and of which the mechanism is, that it arises from the action of the _particles_ of the system, should lead us to the same law for the action of these particles: there is a striking _prerogative_ of simplicity in the law thus adopted. The law of gravitation actually prevailing in the solar system has thus great and clear advantages over any law widely different from it; and has moreover, in many of its consequences, a simplicity which belongs to this precise law alone. It is in many such respects a _unique_ law; and when we consider that it possesses several _properties_ which are _peculiar_ to it, and several _advantages_ which may be peculiar to it, and which are certainly nearly so; we have some ground, it would appear, to look upon its peculiarities and its advantages as connected. For the reasons mentioned in the last chapter, we can hardly expect to see fully the way in which the system is benefited by the simplicity of this law, and by the mathematical elegance of its consequences: but when we see that it has some such beauties, and some manifest benefits, we may easily suppose that our ignorance and limited capacity alone prevent our seeing that there are, for the selection of this law of force, reasons of a far more refined and comprehensive kind than we can distinctly apprehend. 4. But before quitting this subject we may offer a few further observations on the question, whether gravitation and the law of gravitation be _necessary_ attributes of matter. We have spoken of the selection of this law, but is it selected? Could it have been otherwise? Is not the force of attraction a necessary consequence of the fundamental properties of matter? This is a question which has been much agitated among the followers of Newton. Some have maintained, as Cotes, that gravity is an inherent property of all matter; others, with Newton himself, have considered it as an appendage to the essential qualities of matter, and have proposed hypotheses to account for the mode in which its effects are produced. The result of all that can be said on the subject appears to be this: that no one can demonstrate the possibility of deducing gravity from the acknowledged fundamental properties of matter: and that no philosopher asserts, that matter has been found to exist, which was destitute of gravity. It is a property which we have no right to call _necessary_ to matter, but every reason to suppose _universal_. If we could show gravity to be a necessary consequence of those properties which we adopt as essential to our notion of matter, (extension, solidity, mobility, inertia) we might then call it also one of the essential properties. But no one probably will assert that this is the case. Its universality is a fact of observation merely. How then can a property,--in its existence so needful for the support of the universe, in its laws so well adapted to the purposes of creation,--how came it to be thus universal? Its being found every where is necessary for its uses; but this is so far from being a sufficient explanation of its existence, that it is an additional fact to be explained. We have here, then, an agency most simple in its rule, most comprehensive in its influence, most effectual and admirable in its operation. What evidence could be afforded of design, by laws of mechanical action, which this law thus existing and thus operating does not afford us? 5. It is not necessary for our purpose to consider the theories which have been proposed to account for the action of gravity. They have proceeded on the plan of reducing this action to the result of pressure or impulse. Even if such theories could be established, they could not much, or at all, affect our argument; for the arrangements by which pressure or impact could produce the effects which gravity produces, must be at least as clearly results of contrivance, as gravity itself can be. In fact, however, none of these attempts can be considered as at all successful. That of Newton is very remarkable: it is found among the Queries in the second edition of his Optics. “To show,” he says, “that I do not take gravity for an essential property of bodies, I have added one question concerning its cause, choosing to propose it by way of question, because I am not yet satisfied about it for want of experiments.” The hypothesis which he thus suggests is, that there is an elastic medium pervading all space, and increasing in elasticity as we proceed from dense bodies outwards: that this “causes the gravity of such dense bodies to each other: every body endeavouring to go from the denser parts of the medium towards the rarer.” Of this hypothesis we may venture to say, that it is in the first place quite gratuitous; we cannot trace in any other phenomena a medium possessing these properties: and in the next place, that the hypothesis contains several suppositions which are more complex than the fact to be explained, and none which are less so. Can we, on Newton’s principles, conceive an elastic medium otherwise than as a collection of particles, repelling each other? and is the repulsion of such particles a simpler fact than the attraction of those which gravitate? And when we suppose that the medium becomes more elastic as we proceed from each attracting body, what cause can we conceive capable of keeping it in such a condition, except a repulsive force emanating from the body itself: a supposition at least as much requiring to be accounted for, as the attraction of the body. It does not appear, then, that this hypothesis will bear examination; although, for our purpose, the argument would be rather strengthened than weakened, if it could be established. 6. Another theory of the cause of gravity, which at one time excited considerable notice, was that originally proposed by M. Le Sage, in a memoir entitled “Lucrece Newtonien,” and further illustrated by M. Prevost; according to which all space is occupied by currents of matter, moving perpetually in straight lines, in all directions, with a vast velocity, and penetrating all bodies. When two bodies are near each other, they intercept the current which would flow in the intermediate space if they were not there, and thus receive a tendency towards each other from the pressure of the currents on their farther sides. Without examining further this curious and ingenious hypothesis, we may make upon it the same kind of observations as before;--that it is perfectly gratuitous, except as a means of explaining the phenomena; and that, if it were proved, it would still remain to be shown what necessity has caused the existence of these _two kinds_ of matter; the first kind being that which is commonly called matter, and which alone affects our senses, while it is inert as to any tendency to motion; the second kind being something imperceptible to our senses, except by the effects it produces on matter of the former kind; yet exerting an impulse on every material body, permeating every portion of common matter, flowing with inconceivable velocity, in inexhaustible abundance, from every part of the abyss of infinity on one side, to the opposite part of the same abyss; and so constituted that through all eternity it can never bend its path, or return, or tarry in its course. If we were to accept this theory, it would little or nothing diminish our wonder at the structure of the universe. We might well continue to admire the evidence of contrivance, if such a machinery should be found to produce all the effects which flow from the law of gravitation. 7. The arguments for and against the necessity of the law of the inverse square of the distance in the force of gravity, were discussed with great animation about the middle of the last century. Clairault, an eminent mathematician, who did more than almost any other person for the establishment and development of the Newtonian doctrines, maintained, at one period of his researches, not only that the inverse square was not the _necessary_ law, but also that it was not the _true_ law. The occasion of this controversy was somewhat curious. Newton and other astronomers had found that the line of the moon’s _apsides_ (that is of her greatest and least distances from the earth) moves round to different parts of the heavens with a velocity twice as great as that which the calculation from the law of gravitation seems at first to give. According to the theory, it appeared that this line ought to move round once in eighteen years; according to observation, it moves round once in nine years. This difference, the only obvious failure of the theory of gravitation, embarrassed mathematicians exceedingly. It is true, it was afterwards discovered that the apparent discrepancy arose from a mistake; the calculation, which is long and laborious, was supposed to have been carried far enough to get close to the truth; but it appeared afterwards that the residue which had been left out as insignificant, produced, by an unexpected turn in the reckoning, an effect as large as that which had been taken for the whole. But this discovery was not made till afterwards; and in the mean time the law of the inverse square appeared to be at fault. Clairault tried to remedy the defect by supposing that the force of the earth’s gravity consisted of a large force varying as the square of the distance, and a very small force varying as the fourth power (the square of the square.) By such a supposition, observation and theory could be reconciled; but on the suggestion of it, Buffon came forward with the assertion that the force _could_ not vary according to any other law than the inverse square. His arguments are rather metaphysical than physical or mathematical. Gravity, he urges, is a quality, an emanation; and all emanations are inversely as the square of the distance, as light, odours. To this Clairault replies by asking, how we know that light and odours have their intensity inversely as the square of the distance from their origin: not, he observes, by measuring the intensity, but by _supposing_ these effects to be material emanations. But who, he asks, supposes gravity to be a material emanation _from_ the attracting body. Buffon again pleads that so many facts prove the law of the inverse square, that a single one, which occurs to interfere with this agreement, must be in some manner capable of being explained away. Clairault replies, that the facts do _not_ prove this law to obtain exactly; that small effects, of the same order as the one under discussion, have been neglected; and that therefore the law is only known to be true, _as far_ as such an approximation goes, and no farther. Buffon then argues, that there can be no such additional fraction of the force, following a different law, as Clairault supposes: for what, he asks, is there to determine the magnitude of the fraction to one amount rather than another? why should nature select for it any particular magnitude? To this it is replied, that, whether we can explain the fact or not, nature does select certain magnitudes in preference to others: that where we ascertain she does this, we are not to deny the fact because we cannot assign the grounds of her preference. What is there, it is asked, to determine the magnitude of the whole force at any fixed distance? We cannot tell; yet the force is of a certain definite intensity and no other. Finally, Clairault observes, that we have, in cohesion, capillary attraction, and various other cases, examples of forces varying according to other laws than the inverse square; and that therefore this cannot be the only possible law. The discrepancy between observation and theory which gave rise to this controversy was removed, as has been already stated, by a more exact calculation: and thus, as Laplace observes, in this case the metaphysician turned out to be right and the mathematician to be wrong. But most persons, probably, who are familiar with such trains of speculation, will allow, that Clairault had the best of the argument, and that the attempts to show the law of gravitation to be necessarily what it is, are fallacious and unsound. 8. We may observe, however, that the law of gravitation according to the inverse square of the distance, which thus regulates the motions of the solar system, is not confined to that province of the universe, as has been shown by recent researches. It appears by the observations and calculations of Sir John Herschel, that several of the stars, called _double stars_, consist of a pair of luminous bodies which revolve above each other in ellipses, in such a manner as to show that the force, by which they are attracted to each other, varies according to the law of the inverse square. We thus learn a remarkable fact concerning bodies which seemed so far removed that no effort of our science could reach them; and we find that the same law of mutual attraction which we have before traced to the farthest bounds of the solar system, prevails also in spaces at a distance compared with which the orbit of Saturn shrinks into a point. The establishment of such a truth certainly suggests, as highly probable, the prevalence of this law among all the bodies of the universe. And we may therefore suppose, that the same ordinance which gave to the parts of our system that rule by which they fulfil the purposes of their creation, impressed the same rule on the other portions of matter which are scattered in the most remote parts of the universe; and thus gave to their movements the same grounds of simplicity and harmony which we find reason to admire, as far as we can acquire any knowledge of our own more immediate neighbourhood. CHAPTER XI. _The Laws of Motion._ We shall now make a few remarks on the general Laws of Motion by which all mechanical effects take place. Are we to consider these as instituted laws? and if so, can we point out any of the reasons which we may suppose to have led to the selection of those laws which really exist? The observations formerly made concerning the inevitable narrowness and imperfection of our conclusions on such subjects, apply here, even more strongly than in the case of the law of gravitation. We can hardly conceive matter divested of these laws; and we cannot perceive or trace a millionth part of the effects which they produce. We cannot, therefore, expect to go far in pointing out the advantages of these laws such as they now obtain. It would be easy to show that the fundamental laws of motion, in whatever form we state them, possess a very preeminent simplicity, compared with almost all others, which we might imagine as existing. This simplicity has indeed produced an effect on men’s minds which, though delusive, appears to be very natural; several writers have treated these laws as self-evident, and necessarily flowing from the nature of our conceptions. We conceive that this is an erroneous view, and that these laws are known to us to be what they are, by experience only; that they might, so far as we can discern, have been any others. They appear therefore to be selected for their fitness to answer their purposes; and we may, perhaps, be able to point out some instances in which this fitness is apparent to us. Newton, and many English philosophers, teach the existence of _three_ separate fundamental laws of motion, while most of the eminent mathematicians of France reduce these to _two_, the law of inertia and the law that force is proportioned to velocity. As an example of the views which we wish to illustrate, we may take the law of inertia, which is identical with Newton’s first Law of Motion. This law asserts, that a body at rest continues at rest, and that a body in motion goes on moving with its velocity and direction unchanged, except so far as it is acted on by extraneous forces.[24] We conceive that this law, simple and universal as it is, cannot be shown to be necessarily true. It might be difficult to discuss this point in general terms with any clearness; but let us take the only example which we know of a motion absolutely uniform, in consequence of the absence of any force to accelerate or retard it;--this motion is the rotation of the earth on its axis. 1. It is scarcely possible that discussions on such subjects should not have a repulsive and scholastic aspect, and appear like disputes about words rather than things. For mechanical writers have exercised all their ingenuity so to circumscribe their notions and so to define their terms that these fundamental truths should be expressed in the simplest manner: the consequence of which has been, that they have been made to assume the appearance rather of identical assertions than of general facts of experience. But in order to avoid this inconvenience, as far as may be, let us take the _first law of motion_ as exemplified in a particular case, the rotation of the earth. Of all the motions with which we are acquainted this is alone invariable. Each day, measured by the passages of the stars, is so precisely of the same length that, according to Laplace’s calculations, it is impossible that a difference of hundredth of a second of time should have obtained between the length of the day in the earliest ages and at the present time. Now why is this? How is this very remarkable uniformity preserved in this particular phenomenon, while all the other motions of the system are subject to inequalities? How is it that in the celestial machine no retardation takes place by the lapse of time, as would be the case in any machine which it would be possible for human powers to construct? The answer is, that in the earth’s revolution on her axis no cause operates to retard the speed, like the imperfection of materials, the friction of supports, the resistance of the ambient medium; impediments which cannot, in any human mechanism, however perfect, be completely annihilated. But here we are led to ask again, why should the speed continue the same when not affected by an extraneous cause? Why should it not languish and decay of itself by the mere lapse of time? That it might do so, involves no contradiction, for it was the common, though erroneous, belief of all mechanical speculators, to the time of Galileo. We can conceive velocity to diminish in proceeding from a certain point of time, as easily as we can conceive force to diminish in proceeding from a certain point of space, which in attractive forces really occurs. But, it is sometimes said, the _motion_ (that is the velocity) _must_ continue the same from one instant to another, for there is nothing to change it. This appears to be taking refuge in words. We may call the velocity, that is the speed of a body, its motion; but we cannot, by giving it this name, make it a _thing_ which has any _à priori_ claim to permanence, much less any self-evident constancy. Why must the speed of a body, left to itself, continue the same, any more than its temperature? Hot bodies grow cooler of themselves, why should not quick bodies go slower of themselves? Why must a body describe one thousand feet in the next second because it has described one thousand feet in the last? Nothing but experience, under proper circumstances, can inform us whether bodies, abstracting from external agency, do move according to such a rule. We find that they do so, we learn that all diminution of their speed which ever takes place, can be traced to external causes. Contrary to all that men had guessed, motion appears to be of itself endless and unwearied. In order to account for the unalterable permanence of the length of our day, all that is requisite is to show that there is no let or hindrance in the way of the earth’s rotation;--no resisting medium or alteration of size,--she “spinning _sleeps_” on her axle, as the poet expresses it, and may go on sleeping with the same regularity for ever, so far as the experimental properties of motion are concerned. Such is the necessary consequence of the first law of motion; but the law itself has no necessary existence, so far as we can see. It was discovered only after various perplexities and false conjectures of speculators on mechanics. We have learnt that it is so, but we have not learnt, nor can any one undertake to teach us, that it must have been so. For aught we can tell, it is one among a thousand equally possible laws, which might have regulated the motions of bodies. 2. But though we have thus no reason to consider this as the only possible law, we have good reason to consider it as the best, or at least as possessing all that we can conceive of advantage. It is the _simplest_ conceivable of such laws. If the velocity had been compelled to change with the time, there must have been a law of the change, and the kind and amount of this change must have been determined by its dependence on the time and other conditions. This, though quite supposable, would undoubtedly have been more complex than the present state of things. And though complexity does not appear to embarrass the operations of the laws of nature, and is admitted, without scruple, when there is reason for it, simplicity is the usual character of such laws, and appears to have been a ground of selection in the formation of the universe, as it is a mark of beauty to us in our contemplation of it. But there is a still stronger apparent reason for the selection of this law of the preservation of motion. If the case had been otherwise, the universe must necessarily in the course of ages have been reduced to a state of rest, or at least to a state not sensibly differing from it. If the earth’s motion, round its axis, had slackened by a very small quantity, for instance, by a hundredth of a second in a revolution, and in this proportion continued, the day would have been already lengthened by six hours in the six thousand years which have elapsed since the history of the world began; and if we suppose a longer period to precede or to follow, the day might be increased to a month or to any length. All the adaptations which depend on the length of the day would consequently be deranged. But this would not be all; for the same law of motion is equally requisite for the preservation of the annual motion of the earth. If her motion were retarded by the establishment of any other law instead of the existing one, she would wheel nearer and nearer to the sun at every revolution, and at last reach the centre, like a falling hoop. The same would happen to the other planets; and the whole solar system would, in the course of a certain period, be gathered into a heap of matter without life or motion. In the present state of things on the other hand, the system, as we have already explained, is, by a combination of remarkable provisions, calculated for an almost indefinite existence, of undiminished fitness for its purposes. There are, therefore, manifest reasons, why, of all laws which could occupy the place of the first law of motion, the one which now obtains is the only one consistent with the durability and uniformity of the system;--the one, therefore, which we may naturally conceive to be selected by a wise contriver. And as, along with this, it has appeared that we have no sort of right to attribute the establishment of this law to any thing but selection, we have here a striking evidence, to lead us to a perception of that Divine mind, by which means so simple are made to answer purposes so extensive and so beneficial. CHAPTER XII. _Friction._[25] We shall not pursue this argument of the last chapter, by considering the other laws of motion in the same manner as we have there considered the first, which might be done. But the facts which form exceptions and apparent contradictions to the first law of which we have been treating, and which are very numerous, offer, we conceive, an additional exemplification of the same argument; and this we shall endeavour to illustrate. The rule that a body naturally moves for ever with an undiminished speed, is so far from being obviously true, that it appears on a first examination to be manifestly false. The hoop of the school boy, left to itself, runs on a short distance, and then stops; his top spins a little while, but finally flags and falls; all motion on the earth appears to decay by its own nature; all matter which we move appears to have a perpetual tendency to divest itself of the velocity which we communicate to it. How is this reconcileable with the first law of motion on which we have been insisting? It is reconciled principally by considering the effect of _Friction_. Among terrestrial objects friction exerts an agency almost as universal and constant as the laws of motion themselves; an agency which completely changes and disguises the results of those laws. We shall consider some of these effects. It is probably not necessary to explain at any length the nature and operation of friction. When a body cannot move without causing two surfaces to rub together, this rubbing has a tendency to diminish the body’s motion or to prevent it entirely. If the body of a carriage be placed on the earth without the wheels, a considerable force will be requisite in order to move it at all: it is here the friction against the ground which obstructs the motion. If the carriage be placed on its wheels, a much less force will move it, but if moved it will soon stop: it is the friction at the ground and at the axles which stops it: placed on a level rail road, with well made and well oiled wheels, and once put in motion, it might run a considerable distance alone, for the friction is here much less; but there is friction, and therefore the motion would after a time cease. 1. The friction which we shall principally consider is the friction which _prevents_ motion. So employed, friction is one of the most universal and important agents in the mechanism of our daily comforts and occupations. It is a force which is called into play to an extent incomparably greater than all the other forces with which we are concerned in the course of our daily life. We are dependent upon it at every instant and in every action; and it is not possible to enumerate the ways in which it serves us; scarcely even to suggest a sufficient number of them to give us a true notion of its functions. What can appear a more simple operation than standing and walking? yet it is easy to see that without the aid of friction these simple actions would scarcely be possible. Every one knows how difficult and dangerous they are when performed on smooth ice. In such a situation we cannot always succeed in standing: if the ice be very smooth, it is by no means easy to walk, even when the surface is perfectly level; and if it were ever so little inclined, no one would make the attempt. Yet walking on the ice and on the ground differ only in our experiencing more friction in the latter case. We say _more_, for there is a considerable friction even in the case of ice, as we see by the small distance which a stone slides when thrown along the surface. It is this friction of the earth which, at every step we take, prevents the foot from sliding back; and thus allows us to push the body and the other foot forwards. And when we come to violent bodily motions, to running, leaping, pulling or pushing objects, it is easily seen how entirely we depend upon the friction of the ground for our strength and force. Every one knows how completely powerless we become in any of these actions by the _foot slipping_. In the same manner it is the friction of objects to which the hand is applied, which enables us to hold them with any degree of firmness. In some contests it was formerly the custom for the combatants to rub their bodies with oil, that the adversary might not be able to keep his grasp. If the pole of the boatman, the rope of the sailor, were thus smooth and lubricated, how weak would be the thrust and the pull! Yet this would only be the removal of friction. Our buildings are no less dependent on this force for their stability. Some edifices are erected without the aid of cement; and if the stones be large and well squared, such structures may be highly substantial and durable; even when rude and slight, houses so built answer the purposes of life. These are entirely upheld by friction, and without that agent they would be thrown down by the Zephyr, far more easily than if all the stones were lumps of ice with a thawing surface. But even in cases where cement _binds_ the masonry, it does not take the duty of _holding_ it together. In consequence of the existence of friction, there is no constant tendency of the stones to separate; they are in a state of repose. If this were not so, if every shock and every breeze required to be counteracted by the cement, no composition exists which would long sustain such a wear and tear. The cement excludes the corroding elements, and helps to resist extraordinary violence; but it is friction which gives the habitual state of rest. We are not to consider friction as a _small_ force, slightly modifying the effects of other agencies. On the contrary its amount is in most cases very great. When a body lies loose on the ground, the friction is equal to one-third or one-half, or in some cases the whole of its weight. But in cases of bodies supported by oblique pressure, the amount is far more enormous. In the arch of a bridge, the friction which is called into play between two of the vaulting stones, may be equal to the whole weight of the bridge. In such cases this conservative force is so great, that the common theory, which neglects it, does not help us even to guess what will take place. According to the theory, certain forms of arches only will stand, but in practice almost any form will stand, and it is not easy to construct a model of a bridge which will fall. We may see the great force of friction in the _brake_, by which a large weight running down a long inclined plane has its motion moderated and stopt; in the windlass, where a few coils of the rope round a cylinder sustain the stress and weight of a large iron anchor; in the nail or screw which holds together large beams; in the mode of raising large blocks of granite by an iron rod driven into a hole in the stone. Probably no greater forces are exercised in any processes in the arts than the force of friction; and it is always employed to produce rest, stability, moderate motion. Being always ready and never wearied, always at hand and augmenting with the exigency, it regulates, controls, subdues all motions;--counteracts all other agents;--and finally gains the mastery over all other terrestrial agencies, however violent, frequent, or long continued. The perpetual action of all other terrestrial forces appears, on a large scale, only as so many interruptions of the constant and stationary rule of friction. The objects which every where surround us, the books or dishes which stand on our tables, our tables and chairs themselves, the loose clods and stones in the field, the heaviest masses produced by nature or art, would be in a perpetual motion, quick or slow according to the forces which acted on them, and to their size, if it were not for the tranquillizing and steadying effects of the agent we are considering. Without this, our apartments, if they kept their shape, would exhibit to us articles of furniture, and of all other kinds, sliding and creeping from side to side with every push and every wind, like loose objects in a ship’s cabin, when she is changing her course in a gale. Here, then, we have a force, most extensive and incessant in its operation, which is absolutely essential to the business of this terrestrial world, according to any notion which we can form. The more any one considers its effects, and the more he will find how universally dependent he is upon it, in every action of his life; resting or moving, dealing with objects of art or of nature, with instruments of enjoyment or of action. 2. Now we have to observe concerning this agent, Friction, that we have no ground for asserting it to be a necessary result of other properties of matter, for instance, of their solidity and coherency. Philosophers have not been able to deduce the laws of friction from the other known properties of matter, nor even to explain what we know experimentally of such laws, (which is not much,) without introducing new hypotheses concerning the surfaces of bodies, &c.--hypotheses which are not supplied us by any other set of phenomena. So far as our knowledge goes, friction is a separate property, and may be conceived to have been bestowed upon matter for particular purposes. How well it answers the purpose of fitting matter for the uses of the daily life of man, we have already seen. We may make suppositions as to the mode in which friction is connected with the texture of bodies; but little can be gained for philosophy, or for speculation of any kind, by such conjectures respecting unknown connexions. If, on the other hand, we consider this property of friction, and find that it prevails there, and there only, where the general functions, analogies, and relations of the universe require it, we shall probably receive a strong impression that it was introduced into the system of the world _for a purpose_. 3. It is very remarkable that this force, which is thus so efficacious and discharges such important offices in all earthly mechanism, disappears altogether when we turn to the mechanism of the heavens. All motions on the earth soon stop;--a machine which imitates the movements of the stars cannot go long without winding up: but the stars themselves have gone on in their courses for ages, with no diminution of their motions, and offer no obvious prospect of any change. This is so palpable a fact, that the first attempts of men to systematize their mechanical notions were founded upon it. The ancients held that motions were to be distinguished into _natural_ motions and _violent_,--the former go on without diminution--the latter are soon extinguished;--the motions of the stars are of the former kind;--those of a stone thrown, and in short all terrestrial motions, of the latter. Modern philosophers maintain that the laws of motion are the same for celestial and terrestrial bodies;--that all motions are _natural_ according to the above description;--but that in terrestrial motions, friction comes in and alters their character,--destroys them so speedily that they appear to have existed only during an effort. And that this is the case will not now be contested. Is it not then somewhat remarkable that the same laws which produce a state of permanent motion in the heavens, should, on the earth, give rise to a condition in which rest is the rule and motion the exception? The air, the waters, and the lighter portions of matter are, no doubt, in a state of perpetual motion; over these friction has no empire: yet even their motions are interrupted, alternate, variable, and on the whole slight deviations from the condition of equilibrium. But in the solid parts of the globe, rest predominates incomparably over motion: and this, not only with regard to the portions which cohere as parts of the same solid; for the whole surface of the earth is covered with loose masses, which, if the power of friction were abolished, would rush from their places and begin one universal and interminable dance, which would make the earth absolutely uninhabitable. If, on the other hand, the dominion of friction were extended in any considerable degree into the planetary spaces, there would soon be an end of the system. If the planet had moved in a fluid, as the Cartesians supposed, and if this fluid had been subject to the rules of friction which prevail in terrestrial fluids, their motions could not have been of long duration. The solar system must soon have ceased to be a system of revolving bodies. But friction is neither abolished on the earth, nor active in the heavens. It operates where it is wanted, it is absent where it would be prejudicial. And both these circumstances occasion, in a remarkable manner, the steadiness of the course of nature. The stable condition of the objects in man’s immediate neighbourhood, and the unvarying motions of the luminaries of heaven, are alike conducive to his well-being. This requires that he should be able to depend upon a fixed order of place, a fixed course of time. It requires, therefore, that terrestrial objects should be affected by friction, and that celestial should not; as is the case, in fact. What further evidence of benevolent design could this part of the constitution of the universe supply? 4. There is another view which may be taken of the forces which operate on the earth to produce permanency or change. Some parts of the terrestrial system are under the dominion of powers which act energetically to prevent all motion, as the crystalline forces by which the parts of rocks are bound together; other parts are influenced by powers which produce a perpetual movement and change in the matter of which they consist; thus plants and animals are in a constant state of internal movement, by the agency of the vital forces. In the former case rigid immutability, in the latter perpetual developement, are the tendencies of the agencies employed. Now in the case of objects affected by friction, we have a kind of intermediate condition, between the constantly fixed and the constantly moveable. Such objects can and do move; but they move but for a short time if left to the laws of nature. When at rest, they can easily be put in motion, but still not with unlimited ease; a certain finite effort, different in different cases, is requisite for their purpose. Now this immediate condition, this capacity of receiving readily and alternately the states of rest and motion, is absolutely requisite for the nature of man, for the exertion of will, of contrivance, of foresight, as well as for the comfort of life and the conditions of our material existence. If all objects were fixed and immoveable, as if frozen into one mass; or if they were susceptible of such motions only as are found in the parts of vegetables, we attempt in vain to conceive what would come of the business of the world. But besides the state of a particle which cannot be moved, and of a particle which cannot be stopped, we have the state of a particle moveable but not moved; or moved, but moved only while we choose: and this state is that about which the powers, the thoughts, and the wants of man are mainly conversant. Thus the forces by which solidity and by which organic action are produced, the laws of permanence and of developement, do not bring about all that happens. Besides these, there is a mechanical condition, that of a body exposed to friction, which is neither one of absolute permanency nor one naturally progressive; but is yet one absolutely necessary to make material objects capable of being instruments and aids to man; and this is the condition of by far the greater part of terrestrial things. The habitual course of events with regard to motion and rest is not the same for familiar moveable articles, as it is for the parts of the mineral, or of the vegetable world, when left to themselves; such articles are in a condition far better adapted than any of those other conditions would be, to their place and purpose. Surely this shows us an _adaptation_, an adjustment, of the constitution of the material world to the nature of man. And as the organization of plants cannot be conceived otherwise than as having their life and growth for its object, so we cannot conceive that friction should be one of the leading agencies in the world in which man is placed, without supposing that it was intended to be of use when man should walk and run, and build houses and ships, and bridges, and execute innumerable other processes, all of which would be impossible, admirably constituted as man is in other respects, if friction did not exist. And believing, as we conceive we cannot but believe, that the laws of motion and rest were thus given with reference to their ends, we perceive in this instance, as in others, how wide and profound this reference is, how simple in its means, how fertile in its consequences, how effective in its details. BOOK III. RELIGIOUS VIEWS. The contemplation of the material universe exhibits God to us as the author of the laws of material nature; bringing before us a wonderful spectacle, in the simplicity, the comprehensiveness, the mutual adaptation of these laws, and in the vast variety of harmonious and beneficial effects produced by their mutual bearing and combined operation. But it is the consideration of the moral world, of the results of our powers of thought and action, which leads us to regard the Deity in that light in which our relation to him becomes a matter of the highest interest and importance. We perceive that man is capable of referring his actions to principles of right and wrong; that both his faculties and his virtues may be unfolded and advanced by the discipline which arises from the circumstances of human society; that good men can be discriminated from the bad, only by a course of trial, by struggles with difficulty and temptation; that the best men feel deeply the need of relying, in such conflicts, on the thought of a superintending Spiritual power; that our views of justice, our capacity for intellectual and moral advancement, and a crowd of hopes and anticipations which rise in our bosoms unsought, and cling there with inexhaustible tenacity, will not allow us to acquiesce in the belief that this life is the end of our existence. We are thus led to see that our relation the Superintender of our moral being, to the Depositary of the supreme law of just and right, is a relation of incalculable consequence. We find that we cannot be permitted to be merely contemplators and speculators with regard to the Governor of the moral world; we must obey His will; we must turn our affections to Him; we must advance in His favour; or we offend against the nature of our position in the scheme of which He is the author and sustainer. It is far from our purpose to represent natural religion, as of itself sufficient for our support and guidance; or to underrate the manner in which our views of the Lord of the universe have been, much more, perhaps, than we are sometimes aware, illustrated and confirmed by lights derived from revelation. We do not here speak of the manner in which men have come to believe in God, as the Governor of the moral world; but of the fact, that by the aid of one or both of these two guides, Reason or Revelation, reflecting persons in every age have been led to such a belief. And we conceive it may be useful to point out some connexion between such a belief of a just and holy Governor, and the conviction, which we have already endeavoured to impress upon the reader, of a wise and benevolent Creator of the physical world. This we shall endeavour to do in the present book. At the same time that men have thus learnt to look upon God as their Governor and Judge, the source of their support and reward, they have also been led, not only to ascribe to him power and skill, knowledge and goodness, but also attribute to him these qualities in a mode and degree excluding all limit:--to consider him as almighty, all-wise, of infinite knowledge and inexhaustible goodness; every where present and active, but incomprehensible by our minds, both in the manner of his agency, and the degree of his perfections. And this impression concerning the Deity appears to be that which the mind receives from all objects of contemplation and all modes of advance towards truth. To this conception it leaps with alacrity and joy, and in this it acquiesces with tranquil satisfaction and growing confidence; while any other view of the nature of the Divine Power which formed and sustained the world, is incoherent and untenable, exposed to insurmountable objections and intolerable incongruities. We shall endeavour to show that the modes of employment of the thoughts to which the well conducted study of nature gives rise, do tend, in all their forms, to produce or strengthen this impression on the mind; and that such an impression, and no other, is consistent with the widest views and most comprehensive aspects of nature and of philosophy, which our Natural Philosophy opens to us. This will be the purpose of the latter part of the present book. In the first place we shall proceed with the object first mentioned, the connexion which may be perceived between the evidences of creative power, and of moral government, in the world. CHAPTER I. _The Creator of the Physical World is the Governor of the Moral World._ With our views of the moral government of the world and the religious interests of man, the study of material nature is not and cannot be directly and closely connected. But it may be of some service to trace in these two lines of reasoning, seemingly so remote, a manifest convergence to the same point, a demonstrable unity of result. It may be useful to show that we are thus led, not to two rulers of the universe, but to one God;--to make it appear that the Creator and Preserver of the world is also the Governor and Judge of men;--that the Author of the Laws of Nature is also the Author of the Law of Duty;--that He who regulates corporeal things by properties of attraction and affinity and assimilating power, is the same Being who regulates the actions and conditions of men, by the influence of the feeling of responsibility, the perception of right and wrong, the hope of happiness, the love of good. The conviction that the Divine attributes which we are taught by the study of the material world, and those which we learn from the contemplation of man as a responsible agent, belong to the same Divine Being, will be forced upon us, if we consider the manner in which all the parts of the universe, the corporeal and intellectual, the animal and moral, are connected with each other. In each of these provinces of creation we trace refined adaptations and arrangements which lead us to the Creator and Director of so skilful a system; but these provinces are so intermixed, these different trains of contrivance so interwoven, that we cannot, in our thoughts, separate the author of one part from the author of another. The Creator of the Heavens and of the Earth, of the inorganic and of the organic world, of animals and of man, of the affections and the conscience, appears inevitably to be one and the same God. We will pursue this reflection a little more into detail. 1. The _Atmosphere_ is a mere mass of fluid floating on the surface of the ball of the earth; it is one of the inert and inorganic portions of the universe, and must be conceived to have been formed by the same Power which formed the solid mass of the earth and all other parts of the solar system. But how far is the atmosphere from being inert in its effects on organic beings, and unconnected with the world of life! By what wonderful adaptations of its mechanical and chemical properties, and of the vital powers of plants, to each other, are the developement and well-being of plants and animals secured! The creator of the atmosphere must have been also the creator of plants and animals: we cannot for an instant believe the contrary. But the atmosphere is not only subservient to the life of animals, and of man among the rest; it is also the vehicle of voice; it answers the purpose of intercourse; and, in the case of man, of rational intercourse. We have seen how remarkably the air is fitted for this office; the construction of the organs of articulation, by which they are enabled to perform their part of the work, is, as is well known, a most exquisite system of contrivances. But though living in an atmosphere capable of transmitting articulate sound, and though provided with organs fitted to articulate, man would never attain to the use of language, if he were not also endowed with another set of faculties. The powers of abstraction and generalization, memory and reason, the tendencies which occasion the inflexions and combinations of words, are all necessary to the formation and use of language. Are not these parts of the same scheme of which the bodily faculties by which we are able to speak are another part? Has man his mental powers independently of the creator of his bodily frame? To what purpose then, or by what cause was the curious and complex machinery of the tongue, the glottis, the larynx produced? These are useful for speech, and full of contrivances which suggest such a use as the end for which those organs were constructed. But speech appears to have been no less contemplated in the intellectual structure of man. The processes of which we have spoken, generalization, abstraction, reasoning, have a close dependence on the use of speech. These faculties are presupposed in the formation of language, but they are developed and perfected by the use of language. The mind of man then, with all its intellectual endowments, is the work of the same artist by whose hands his bodily frame was fashioned; as his bodily faculties again are evidently constructed by the maker of those elements on which their action depends. The creator of the atmosphere and of the material universe is the creator of the human mind, and the author of those wonderful powers of thinking, judging, inferring, discovering, by we are able to reason concerning the world in which we are placed; and which aid us in lifting our thoughts to the source of our being himself. 2. _Light_, or the means by which light is propagated, is another of the inorganic elements which forms a portion of the mere material world. The luminiferous ether, if we adopt that theory, or the fluid light of the theory of emission, must indubitably pervade the remotest regions of the universe, and must be supposed to exist, as soon as we suppose the material parts of the universe to be in existence. The origin of light then must be at least as far removed from us as the origin of the solar system. Yet how closely connected are the properties of light with the structure of our own bodies! The mechanism of the organs of vision and the mechanism of light are, as we have seen, most curiously adapted to each other. We must suppose, then, that the same power and skill produced one and the other of these two sets of contrivances, which so remarkably _fit into_ each other. The creator of light is the author of our visual powers. But how small a portion does mere visual perception constitute of the advantages which we derive from vision! We possess ulterior faculties and capacities by which sight becomes a source of happiness and good to man. The sense of beauty, the love of art, the pleasure arising from the contemplation of nature, are all dependent on the eye; and we can hardly doubt that these faculties were bestowed on man to further the best interests of his being. The sense of beauty both animates and refines his domestic tendencies; the love of art is a powerful instrument for raising him above the mere cravings and satisfactions of his animal nature; the expansion of mind which rises in us at the sight of the starry sky, the cloud-capt mountain, the boundless ocean, seems intended to direct our thoughts by an impressive though indefinite feeling, to the Infinite Author of All. But if these faculties be thus part of the scheme of man’s inner being, given him by a good and wise creator, can we suppose that this creator was any other than the creator also of those visual organs, without which the faculties could have no operation and no existence? As clearly as light and the eye are the work of the same author, so clearly also do our capacities for the most exalted visual pleasures, and the feelings flowing from them, proceed from the same Divine Hand. 3. The creator of the earth must be conceived to be the author also of all those qualities in the soil, chemical and whatever else, by which it supports vegetable life, under all the modifications of natural and artificial condition. Among the attributes which the earth thus possesses, there are some which seem to have an especial reference to man in a state of society. Such are--the power of the earth to increase its produce under the influence of cultivation, and the necessary existence of property in land, in order that this cultivation may be advantageously applied; the rise, under such circumstances, of a _surplus_ produce, of a quantity of subsistence exceeding the wants of the cultivators alone; and the consequent possibility of inequalities of rank, and of all the arrangements of civil society. These are all parts of the constitution of the earth. But these would all remain mere idle possibilities, if the nature of man had not a corresponding direction. If man had not a social and economical tendency, a disposition to congregate and co-operate, to distribute possessions and offices among the members of the community, to make and obey and enforce laws, the earth would in vain be ready to respond to the care of the husbandman. Must we not then suppose that this attribute of the earth was bestowed upon it by Him who gave to man those corresponding attributes, through which the apparent niggardliness of the soil is the source of general comfort and security, of polity and law? Must we not suppose that He who created the soil also inspired man with those social desires and feelings which produce cities and states, laws and institutions, arts and civilization; and that thus the apparently inert mass of earth is a part of the same scheme as those faculties and powers with which man’s moral and intellectual progress is most connected? 4. Again:--It will hardly be questioned that the author of the material elements is also the author of the structure of animals, which is adapted to and provided for by the constitution of the elements in such innumerable ways. But the author of the bodily structure of animals must also be the author of their instincts, for without these the structure would not answer its purpose. And these instincts frequently assume the character of affections in a most remarkable manner. The love of offspring, of home, of companions, are often displayed by animals, in a way that strikes the most indifferent observer; and yet these affections will hardly be denied to be a part of the same scheme as the instincts by which the same animals seek food and the gratifications of sense. Who can doubt that the anxious and devoted affection of the mother-bird for her young after they are hatched, is a part of the same system of Providence as the instinct by which she is impelled to sit upon her eggs? and this, of the same by which her eggs are so organized that incubation leads to the birth of the young animal? Nor, again, can we imagine that while the structure and affections of animals belong to one system of things, the affections of man, in many respects so similar to those of animals, and connected with the bodily frame in a manner so closely analogous, can belong to a different scheme. Who, that reads the touching instances of maternal affection, related so often of the women of all nations, and of the females of all animals, can doubt that the principle of action is the same in the two cases, though enlightened in one of them by the rational faculty: And who can place in separate provinces the supporting and protecting love of the father and the mother? or consider as entirely distinct from these, and belonging to another part of our nature, the other kinds of family affection? or disjoin man’s love of his home, his clan, his tribe, his country, from the affection which he bears to his family? The love of offspring, home, friends, in man, is then part of the same system of contrivances of which bodily organization is another part. And thus the author of our corporeal frame is also the author of our capacity of kindness and resentment, of our love and of our wish to be loved, of all the emotions which bind us to individuals, to our families, and to our kind. It is not necessary here to follow out and classify these emotions and affections; or to examine how they are combined and connected with our other motives of action, mutually giving and receiving strength and direction. The desire of esteem, of power, of knowledge, of society, the love of kindred, of friends, of our country, are manifestly among the main forces by which man is urged to act and to abstain. And as these parts of the constitution of man are clearly intended, as we conceive, to impel him in his appointed path; so we conceive that they are no less clearly the work of the same great Artificer who created the heart, the eye, the hand, the tongue, and that elemental world in which, by means of these instruments, man pursues the objects of his appetites, desires, and affections. 5. But if the Creator of the world be also the author of our intellectual powers, of our feeling for the beautiful and the sublime, of our social tendencies, and of our natural desires and affections, we shall find it impossible not to ascribe also to Him the higher directive attributes of our nature, the conscience and the religious feeling, the reference of our actions to the rule of duty and to the will of God. It would not suit the plan of the present treatise to enter into any detailed analysis of the connexion of these various portions of our moral constitution. But we may observe that the existence and universality of the conception of duty and right cannot be doubted, however men may differ as to its original or derivative nature. All men are perpetually led to form judgments concerning actions, and emotions which lead to action, as right or wrong; as what they _ought_ or _ought not_ to do or feel. There is a faculty which approves and disapproves, acquits or condemns the workings of our other faculties. Now, what shall we say of such a judiciary principle, thus introduced among our motives to action? Shall we conceive that while the other springs of action are balanced against each other by our Creator, this, the most pervading and universal regulator, was no part of the original scheme? That--while the love of animal pleasures, of power, of fame, the regard for friends, the pleasure of bestowing pleasure, were infused into man as influences by which his course of life was to be carried on, and his capacities and powers developed and exercised;--this reverence for a moral law, this acknowledgment of the obligation of duty,--a feeling which is every where found, and which may become a powerful, a predominating motive of action,--was given for no purpose, and belongs not to the design? Such an opinion would be much as if we should acknowledge the skill and contrivance manifested in the other parts of a ship, but should refuse to recognize the rudder as exhibiting any evidence of a purpose. Without the reverence which the opinion of right inspires, and the scourge of general disapprobation inflicted on that which is accounted wicked, society could scarcely go on; and certainly the feelings and thoughts and characters of men could not be what they are. Those impulses of nature which involve no acknowledgment of responsibility, and the play and struggle of interfering wishes, might preserve the species in some shape of existence, as we see in the case of brutes. But a person must be strangely constituted, who, living amid the respect for law, the admiration for what is good, the order and virtues and graces of civilized nations, (all which have their origin in some degree in the feeling of responsibility) can maintain that all these are casual and extraneous circumstances, no way contemplated in the formation of man; and that a condition in which there should be obligation in law, no merit in self-restraint, no beauty in virtue, is equally suited to the powers and the nature of man, and was equally contemplated when those powers were given him. If this supposition be too extravagant to be admitted, as it appears to be, it remains then that man, intended, as we have already seen from his structure and properties, to be a discoursing, social being, acting under the influence of affections, desires, and purposes, was also intended to act under the influence of a sense of duty; and that the acknowledgment of the obligation of a moral law is as much part of his nature, as hunger or thirst, maternal love or the desire of power; that, therefore, in conceiving man as the work of a Creator, we must imagine his powers and character given him with an intention on the Creator’s part that this sense of duty should occupy its place in his constitution as an active and thinking being: and that this directive and judiciary principle is a part of the work of the same Author who made the elements to minister to the material functions, and the arrangements of the world to occupy the individual and social affections of his living creatures. This principle of conscience, it may further be observed, does not stand upon the same level as the other impulses of our constitution by which we are prompted or restrained. By its very nature and essence, it possesses a supremacy over all others. “Your obligation to obey this law is its being the law of your nature. That your conscience approves of and attests such a course of action is itself alone an obligation. Conscience does not only offer itself to show us the way we should walk in, but it likewise carries its own authority with it, that it is our natural guide: the guide assigned us by the author of our nature.”[26] That we ought to do an action, is of itself a sufficient and ultimate answer to the questions, _why_ we should do it?--how we are _obliged_ to do it? The conviction of duty implies the soundest reason, the strongest obligation, of which our nature is susceptible. We appear then to be using only language which is well capable of being justified, when we speak of this irresistible esteem for what is right, this conviction of a rule of action extending beyond the gratification of our irreflective impulses, as an impress stamped upon the human mind by the Deity himself; a trace of His nature; an indication of His will; an announcement of His purpose; a promise of His favour: and though this faculty may need to be confirmed and unfolded, instructed and assisted by other aids, it still seems to contain in itself a sufficient intimation that the highest objects of man’s existence are to be attained, by means of a direct and intimate reference of his thoughts and actions to the Divine Author of his being. Such then is the Deity to which the researches of Natural Theology point; and so far is the train of reflections in which we have engaged, from being merely speculative and barren. With the material world we cannot stop. If a superior Intelligence _have_ ordered and adjusted the succession of seasons and the structure of the plants of the field, we must allow far more than this at first sight would seem to imply. We must admit still greater powers, still higher wisdom for the creation of the beasts of the forest with their faculties; and higher wisdom still and more transcendent attributes, for the creation of man. And when we reach this point, we find that it is not knowledge only, not power only, not foresight and beneficence alone, which we must attribute to the Maker of the World; but that we must consider him as the Author, in us, of a reverence for moral purity and rectitude; and, if the author of such emotions in us, how can we conceive of Him otherwise, than that these qualities are parts of his nature; and that he is not only wise and great, and good, incomparably beyond our highest conceptions, but also conformed in his purposes to the rule which he thus impresses upon us, that is, Holy in the highest degree which we can imagine to ourselves as possible. CHAPTER II. _On the Vastness of the Universe._ 1. The aspect of the world, even without any of the peculiar lights which science throws upon it, is fitted to give us an idea of the greatness of the power by which it is directed and governed, far exceeding any notions of power and greatness which are suggested by any other contemplation. The number of human beings who surround us--the various conditions requisite for their life, nutrition, well-being, all fulfilled;--the way in which these conditions are modified, as we pass in thought to other countries, by climate, temperament, habit;--the vast amount of the human population of the globe thus made up;--yet man himself but one among almost endless tribes of animals;--the forest, the field, the desert, the air, the ocean, all teeming with creatures whose bodily wants are as carefully provided for as his;--the sun, the clouds, the winds, all attending, as it were, on these organized beings;--a host of beneficent energies, unwearied by time and succession, pervading every corner of the earth;--this spectacle cannot but give the contemplator a lofty and magnificent conception of the Author of so vast a work, of the Ruler of so wide and rich an empire, of the Provider for so many and varied wants, the Director and Adjuster of such complex and jarring interests. But when we take a more exact view of this spectacle, and aid our vision by the discoveries which have been made of the structure and extent of the universe, the impression is incalculably increased. The number and variety of animals, the exquisite skill displayed in their structure, the comprehensive and profound relations by which they are connected, far exceed any thing which we could in any degree have imagined. But the view of the universe expands also on another side. The earth, the globular body thus covered with life, is not the only globe in the universe. There are, circling about our own sun, six others, so far as we can judge, perfectly analogous in their nature: besides our moon and other bodies analogous to it. No one can resist the temptation to conjecture, that these globes, some of them much larger than our own, are not dead and barren;--that they are, like ours, occupied with organization, life, intelligence. To conjecture is all that we can do, yet even by the perception of such a possibility, our view of the kingdom of nature is enlarged and elevated. The outermost of the planetary globes of which we have spoken is so far from the sun, that the central luminary must appear to the inhabitants of that planet, if any there are, no larger than Venus does to us; and the length of their year will be eighty-two of ours. But astronomy carries us still onwards. It teaches us that, with the exception of the planets already mentioned, the stars which we see have no immediate relation to our system. The obvious supposition is that they are of the nature and order of our sun: the minuteness of their apparent magnitude agrees, on this supposition, with the enormous and almost inconceivable distance which, from all the measurements of astronomers, we are led to attribute to them. If then these are suns, they may, like our sun, have planets revolving round them; and these may, like our planet, be the seats of vegetable and animal and rational life:--we may thus have in the universe worlds, no one knows how many, no one can guess how varied:--but however many, however varied, they are still but so many provinces in the same empire, subject to common rules, governed by a common power. But the stars which we see with the naked eye are but a very small portion of those which the telescope unveils to us. The most imperfect telescope will discover some that are invisible without it; the very best instrument perhaps does not show us the most remote. The number which crowds some parts of the heavens is truly marvellous. Dr. Herschel calculated that a portion of the milky way, about ten degrees long and two and a half broad, contained two hundred and fifty-eight thousand. In a sky so occupied, the moon would eclipse two thousand of such stars at once. We learn too from the telescope that even in this province the variety of nature is not exhausted. Not only do the stars differ in colour and appearance, but some of them grow periodically fainter and brighter, as if they were dark on one side, and revolved on their axes. In other cases two stars appear close to each other, and in some of these cases it has been clearly established, that the two have a motion of revolution about each other; thus exhibiting an arrangement before unguessed, and giving rise, possibly, to new conditions of worlds. In other instances again, the telescope shows, not luminous points, but extended masses of dilute light, like bright clouds, hence called _nebulæ_. Some have supposed (as we have noticed in the last book) that such nebulæ by further condensation might become suns; but for such opinions we have nothing but conjecture. Some stars again have undergone permanent changes, or have absolutely disappeared, as the celebrated star of 1572, in the constellation Cassiopea. If we take the whole range of created objects in our own system, from the sun down to the smallest animalcule, and suppose such a system, or something in some way analogous to it, to be repeated for each of the millions of stars thus revealed to us, we have a representation of the material part of the universe, according to a view which many minds receive as a probable one; and referring this aggregate of systems to the Author of the universe, as in our own system we have found ourselves led to do, we have thus an estimate of the extent to which his creative energy would thus appear to have been exercised in the material world. If we consider further the endless and admirable contrivances and adaptations which philosophers and observers have discovered in every portion of our own system, every new step of our knowledge showing us something new in this respect; and if we combine this consideration with the thought how small a portion of the universe our knowledge includes, we shall, without being able at all to discern the extent of the skill and wisdom thus displayed, see something of the character of the design, and of the copiousness and ampleness of the means which the scheme of the world exhibits. And when we see that the tendency of all the arrangements which we can comprehend is to support the existence, to develope the faculties, to promote the well-being of these countless species of creatures; we shall have some impression of the beneficence and love of the Creator, as manifested in the physical government of his creation. 2. It is extremely difficult to devise any means of bringing before a common apprehension the scale on which the universe is constructed, the enormous proportion which the larger dimensions bear to the smaller, and the amazing number of steps from large to smaller, or from small to larger, which the consideration of it offers. The following comparative representations may serve to give the reader to whom the subject is new some idea of these steps. If we suppose the earth to be represented by a globe a foot in diameter, the distance of the sun from the earth will be about two miles; the diameter of the sun, on the same supposition, will be something above one hundred feet, and consequently his bulk such as might be made up of two hemispheres, each about the size of the dome of St. Paul’s. The moon will be thirty feet from us, and her diameter three inches, about that of a cricket ball. Thus the sun would much more than occupy all the space within the moon’s orbit. On the same scale, Jupiter would be above ten miles from the sun, and Uranus forty. We see then how thinly scattered through space are the heavenly bodies. The fixed stars would be at an unknown distance, but, probably, if all distances were thus diminished, no star would be nearer to such a one-foot earth, than the moon now is to us. On such a terrestrial globe the highest mountains would be about an eightieth of an inch high, and consequently only just distinguishable. We may imagine therefore how imperceptible would be the largest animals. The whole organized covering of such a globe would be quite undiscoverable by the eye, except perhaps by colour, like the bloom on a plum. In order to restore this earth and its inhabitants to their true dimensions, we must magnify them forty millions of times; and to preserve the proportions, we must increase equally the distances of the sun and of the stars from us. They seem thus to pass off into infinity; yet each of them thus removed, has its system of mechanical and perhaps of organic processes going on upon its surface. But the arrangements of organic life which we can see with the naked eye are few, compared with those which the microscope detects. We know that we may magnify objects thousands of times, and still discover fresh complexities of structure; if we suppose, therefore, that we increase every particle of matter in our universe in such a proportion, in length, breadth, and thickness, we may conceive that we tend thus to bring before our apprehension a true estimate of the quantity of organized adaptations which are ready to testify the extent of the Creator’s power. 3. The other numerical quantities which we have to consider in the phenomena of the universe are on as gigantic a scale as the distances and sizes. By the rotation of the earth on its axis, the parts of the equator move at the rate of a thousand miles an hour, and the portions of the earth’s surface which are in our latitude, at about six hundred. The former velocity is nearly that with which a cannon ball is discharged from the mouth of a gun; but, large as it is, it is inconsiderable compared with the velocity of the earth in its orbit about the sun. This latter velocity is sixty-five times the former. By the rotatory motion of the earth, a point of its surface is carried sometimes forwards and sometimes backwards with regard to the annual progression; but in consequence of the great predominance of the latter velocity in amount, the former scarcely affects it either way. And even the latter velocity is inconsiderable compared with that of light; which comparison, however, we shall not make; since, according to the theory we have considered as most probable, the motion of light is not a transfer of matter but of motion from one part of space to another. The extent of the scale of density of different substances has already been mentioned; gold is twenty times as heavy as water; air is eight hundred and thirty times lighter, steam eight thousand times lighter than water; the luminiferous ether is incomparably rarer than steam: and this is true of the matter of light, whether we adopt the undulatory theory or any other. 4. The above statements are vast in amount, and almost oppressive to our faculties. They belong to the measurement of the powers which are exerted in the universe, and of the spaces through which their efficacy reaches (for the most distant bodies are probably connected both by gravity and light.) But these estimates cannot be said so much to give us any notion of the powers of the Deity, as to correct the errors we should fall into by supposing his powers at all to resemble ours:--by supposing that numbers, and spaces, and forces, and combinations, which would overwhelm us, are any obstacle to the arrangements which his plan requires. We can easily understand that to an intelligence surpassing ours in degree only, that may be easy which is impossible to us. The child who cannot count beyond four, the savage who has no name for any number above five, cannot comprehend the possibility of dealing with thousands and millions: yet a little additional developement of the intellect makes such numbers manageable and conceivable. The difficulty which appears to reside in numbers and magnitudes and stages of subordination, is one produced by judging from ourselves--by measuring with our own sounding line; when that reaches no bottom, the ocean appears unfathomable. Yet in fact, how is a hundred millions of miles a _great_ distance? how is a hundred millions of times a _great_ ratio? Not in itself: this _greatness_ is no quality of the numbers which can be proved like their mathematical properties; on the contrary, all that absolutely belongs to number, space, and ratio, must, we know demonstrably, be equally true of the largest and the smallest. It is clear that the _greatness_ of these expressions of measure has reference to _our_ faculties only. Our astonishment and embarrassment take for granted the limits of our own nature. We have a tendency to treat a difference of degree and of addition, as if it were a difference of kind and of transformation. The existence of the attributes, design, power, goodness, is a matter depending on obvious grounds: about these qualities there can be no mistake: if we can know any thing, we can know these attributes when we see them. But the extent, the limits of such attributes must be determined by their effects; our knowledge of their limits by what we see of the effects. Nor is any extent, any amount of power and goodness improbable beforehand: we know that these must be great, we cannot tell how great. We should not expect beforehand to find them bounded; and therefore when the boundless prospect opens before us, we may be bewildered, but we have no reason to be shaken in our conviction of the reality of the cause from which their effects proceed: we may feel ourselves incapable of following the train of thought, and may stop, but we have no rational motive for quitting the point which we have thus attained in tracing the Divine Perfections. On the contrary, those magnitudes and proportions which leave our powers of conception far behind;--that ever-expanding view which is brought before us, of the scale and mechanism, the riches and magnificence, the population and activity of the universe;--may reasonably serve, not to disturb, but to enlarge and elevate our conceptions of the Maker and Master of all; to feed an ever-growing admiration of His wonderful nature; and to excite a desire to be able to contemplate more steadily and conceive less inadequately the scheme of his government and the operation of his power. CHAPTER III. _On Man’s Place in the Universe._ The mere aspect of the starry heavens, without taking into account the view of them to which science introduces us, tends strongly to force upon man the impression of his own insignificance. The vault of the sky arched at a vast and unknown distance over our heads; the stars, apparently infinite in number, each keeping its appointed place and course, and seeming to belong to a wide system of things which has no relation to the earth; while man is but one among many millions of the earth’s inhabitants;--all this makes the contemplative spectator feel how exceedingly small a portion of the universe he is; how little he must be, in the eyes of an intelligence which can embrace the whole. Every person, in every age and country, will recognize as irresistibly natural the train of thought expressed by the Hebrew psalmist: “when I consider the heavens the work of thy hands--the moon and the stars which thou hast ordained--Lord what is man that thou art mindful of him, or the son of man that thou regardest him?” If this be the feeling of the untaught person, when he contemplates the aspect of the skies, such as they offer themselves to a casual and unassisted glance, the impression must needs be incalculably augmented, when we look at the universe with the aid of astronomical discovery and theory. We then find, that a few of the shining points which we see scattered on the face of the sky in such profusion, appear to be of the same nature as the earth, and may perhaps, as analogy would suggest, be like the earth, the habitations of organized beings;--that the rest of “the host of heaven” may, by a like analogy, be conjectured to be the centres of similar systems of revolving worlds;--that the vision of man has gone travelling onwards, to an extent never anticipated, through this multitude of systems, and that while myriads of new centres start up at every advance, he appears as yet not to have received any intimation of a limit. Every person probably feels, at first, lost, confounded, overwhelmed, with the vastness of this spectacle; and seems to himself, as it were, annihilated by the magnitude and multitude of the objects which thus compose the universe. The distance between him and the Creator of the world appears to be increased beyond measure by this disclosure. It seems as if a single individual could have no chance and no claim for the regard of the Ruler of the whole. The mode in which the belief of God’s government of the physical world is important and interesting to man, is, as has already been said, through the connexion which this belief has with the conviction of God’s government of the moral world; this latter government being, from its nature, one which has a personal relation to each individual, his actions and thoughts. It will, therefore, illustrate our subject to show that this impression of the difficulty of a personal superintendence and government, exercised by the Maker of the world over each of his rational and free creatures, is founded upon illusory views; and that on an attentive and philosophical examination of the subject, such a government is in accordance with all that we can discover of the scheme and the scale of the universe. 1. We may, in the first place, repeat the observation made in the last chapter, on the confusion which sometimes arises in our minds, and makes us consider the number of the objects of the Divine care as a difficulty in the way of its exercise. If we can conceive this care employed on a million of persons, on the population of a kingdom, of a city, of a street, there is no real difficulty in supposing it extended to every planet in the solar system, admitting each to be peopled as ours is; nor to every part of the universe, supposing each star the centre of such a system. _Numbers_ are nothing in themselves; and when we reject the known, but unessential limits of our own faculties, it is quite as allowable to suppose a million millions of earths, as one, to be under the moral government of God. 2. In the next place we may remark, not only that no reason can be assigned why the Divine care should not extend to a much greater number of individuals than we at first imagine, but that in fact we know that it _does_ so extend. It has been well observed, that about the same time when the invention of the telescope showed us that there might be myriads of other worlds claiming the Creator’s care; the invention of the microscope proved to us that there were in our own world myriads of creatures, before unknown, which this care was preserving. While one discovery seemed to remove the Divine Providence further from us, the other gave us most striking examples that it was far more active in our neighbourhood than we had supposed: while the first extended the boundaries of God’s known kingdom, the second made its known administration more minute and careful. It appeared that in the leaf and in the bud, in solids and in fluids, animals existed hitherto unsuspected; the apparently dead masses and blank spaces of the world were found to swarm with life. And yet, of the animals thus revealed, all, though unknown to us before, had never been forgotten by Providence. Their structure, their vessels and limbs, their adaptation to their situation, their food and habitations, were regulated in as beautiful and complete a manner as those of the largest and apparently most favoured animals. The smallest insects are as exactly finished, often as gaily ornamented, as the most graceful beasts or the birds of brightest plumage. And when we seem to go out of the domain of the complex animal structure with which we are familiar, and come to animals of apparently more scanty faculties, and less developed powers of enjoyment and action, we still find that their faculties and their senses are in exact harmony with their situation and circumstances; that the wants which they have are provided for, and the powers which they possess called into activity. So that Müller, the patient and accurate observer of the smallest and most obscure microscopical animalcula, declares that all classes alike, those which have manifest organs, and those which have not, offer a vast quantity of new and striking views of the animal economy; every step of our discoveries leading us to admire the design and care of the Creator.[27] We find, therefore, that the Divine Providence is, in fact, capable of extending itself adequately to an immense succession of tribes of beings, surpassing what we can imagine or could previously have anticipated; and thus we may feel secure, so far as analogy can secure us, that the mere multitude of created objects cannot remove us from the government and superintendence of the Creator. 3. We may observe further, that, vast as are the parts and proportions of the universe, we still appear to be able to perceive that it is _finite_; the subordination of magnitudes and numbers and classes appears to have its limits. Thus, for any thing which we can discover, the sun is the largest body in the universe; and at any rate, bodies of the order of the sun are the largest of which we have any evidence: we know of no substance denser than gold, and it is improbable that one denser, or at least much denser, should ever be detected: the largest animals which exist in the sea and on the earth are almost certainly known to us. We may venture also to say, that the smallest animals which possess in their structure a clear analogy with larger ones, have been already seen. Many of the animals which the microscope detects, are as complete and complex in their organization as those of larger size: but beyond a certain point, they appear, as they become more minute, to be reduced to a homogeneity and simplicity of composition which almost excludes them from the domain of animal life. The smallest microscopical objects which can be supposed to be organic, are points,[28] or gelatinous globules,[29] or threads,[30] in which no distinct organs, interior or exterior, can be discovered. These, it is clear, cannot be considered as indicating an indefinite progression of animal life in a descending scale of minuteness. We can, mathematically speaking, conceive one of these animals as perfect and complicated in its structure as an elephant or an eagle, but we do not find it so in nature. It appears, on the contrary, in these objects, as if we were, at a certain point of magnitude, reaching the boundaries of the animal world. We need not here consider the hypotheses and opinions to which these ambiguous objects have given rise; but, without any theory, they tend to show that the subordination of organic life is finite on the side of the little as well as of the great. Some persons might, perhaps, imagine that a ground for believing the smallness of organized beings to be limited, might be found in what we know of the constitution of matter. If solids and fluids consist of particles of a definite, though exceeding smallness, which cannot further be divided or diminished, it is manifest that we have, in the smallness of these particles, a limit to the possible size of the vessels and organs of animals. The fluids which are secreted, and which circulate in the body of a mite, must needs consist of a vast number of particles, or they would not be fluids: and an animal might be so much smaller than a mite, that its tubes could not contain a sufficient collection of the atoms of matter, to carry on its functions. We should, therefore, of necessity reach a limit of minuteness in organic life, if we could demonstrate that matter is composed of such indivisible atoms. We shall not, however, build any thing on this argument; because, though the _atomic theory_ is sometimes said to be proved, what is proved is, that chemical and other effects take place as if they were the aggregate of the effects of certain particles of elements, the _proportions_ of which particles are fixed and definite; but that any limit can be assigned to the smallness of these particles, has never yet been made out. We prefer, therefore, to rest the proof of the finite extent of animal life, as to size, on the microscopical observations previously referred to. Probably we cannot yet be said to have reached the limit of the universe with the power of our telescopes; that is, it does not appear that telescopes have yet been used, so powerful in exhibiting small stars, that we can assume that more powerful instruments would not discover new stars. Whether or no, however, this degree of perfection has been reached, we have no proof that it does not exist; if it were once obtained we should have, with some approximation, the limit of the universe as to the number of worlds, as we have already endeavoured to show we have obtained the limits with regard to the largeness and smallness of the inhabitants of our own world. In like manner, although the discovery of new species in some of the kingdoms of nature has gone on recently with enormous rapidity, and to an immense extent;--for instance in botany, where the species known in the time of Linnæus were about ten thousand, and are now probably fifty thousand;--there can be no doubt that the number of species and genera is really limited; and though a great extension of our knowledge is required to reach these limits, it is our ignorance merely, and not their nonexistence, which removes them from us. In the same way it would appear that the universe, so far as it is an object of our knowledge, is finite in other respects also. Now when we have once attained this conviction, all the oppressive apprehension of being overlooked in the government of the universe has no longer any rational source. For in the superintendence of a finite system of things, what is there which can appear difficult or overwhelming to a Being such as we must, from what we know, conceive the Creator to be? Difficulties arising from space, number, gradation, are such as we can conceive _ourselves_ capable of overcoming, merely by an extension of our present faculties. Is it not then easy to imagine that such difficulties must vanish before Him who made us and our faculties? Let it be considered how enormous a proportion the largest work of man bears to the smallest;--the great pyramid to the point of a needle. This comparison does not overwhelm us, because we know that man has made both. Yet the difference between this proportion and that of the sun to the claw of a mite, does not at all correspond to the difference which we must suppose to obtain between the Creator and the creature. It appears then that, if the first flash of that view of the universe which science reveals to us, does sometimes dazzle and bewilder men, a more attentive examination of the prospect, by the light we thus obtain, shows us how unfounded is the despair of our being the objects of Divine Providence, how absurd the persuasion that we have discovered the universe to be too large for its ruler. 4. Another ground of satisfactory reflection, having the same tendency, is to be found in the admirable order and consistency, the subordination and proportion of parts, which we find to prevail in the universe, as far as our discoveries reach. We have, it may be, a multitude almost innumerable of worlds, but no symptom of crowding, of confusion, of interference. All such defects are avoided by the manner in which these worlds are distributed into systems;--these systems, each occupying a vast space, but yet disposed at distances before which their own dimensions shrink into insignificance;--all governed by one law, yet this law so concentrating its operation on each system, that each proceeds as if there were no other, and so regulating its own effects that perpetual change produces permanent uniformity. This is the kind of harmonious relation which we perceive in that part of the universe, the mechanical part namely, the laws of which are best known to us. In other provinces, where our knowledge is more imperfect, we can see glimpses of a similar vastness of combination, producing, by its very nature, completeness of detail. Any analogy by which we can extend such views to the moral world, must be of a very wide and indefinite kind; yet the contemplation of this admirable relation of the arrangements of the physical creation, and the perfect working of their laws, is well calculated to give us confidence in a similar beauty and perfection in the arrangements by which our moral relations are directed, our higher powers and hopes unfolded. We may readily believe that there is, in this part of the creation also, an order, a subordination of some relations to others, which may remove all difficulty arising from the vast multitude of moral agents and actions, and make it possible that the superintendence of the moral world shall be directed with as exact a tendency to moral good, as that by which the government of the physical world is directed to physical good. We may perhaps see glimpses of such an order, in the arrangements by which our highest and most important duties depend upon our relation to a small circle of persons immediately around us: and again, in the manner in which our acting well or ill results from the operation of a few principles within us; as our conscience, our desire of moral excellence, and of the favour of God. We can hardly consider such principles otherwise than as intended to occupy their proper place in the system by which man’s destination is to be determined; and thus, as among the means of the government and superintendence of God in the moral world. That there must be an order and a system to which such regulative principles belong, the whole analogy of creation compels us to believe. It would be strange indeed, if, while the mechanical world, the system of inert matter, is so arranged that we cannot contemplate its order without an elevated intellectual pleasure;--while organized life has no faculties without their proper scope, no tendencies without their appointed object;--the rational faculties and moral tendencies of man should belong to no systematic order, should operate with no corresponding purpose: that, while the perception of sweet and bitter has its acknowledged and unmistakeable uses, the universal perception of right and wrong, the unconquerable belief of the merit of certain feelings and actions, the craving alike after moral advancement and after the means of attaining it, should exist only to delude, perplex, and disappoint man. No one, with his contemplations calmed and filled and harmonized by the view of the known constitution of the universe, its machinery “wheeling unshaken” in the farthest skies and in the darkest cavern, its vital spirit breathing alike effectively in the veins of the philosopher and the worm;--no one, under the influence of such a train of contemplations, can possibly admit into his mind a persuasion which makes the moral part of our nature a collection of inconsistent and futile impressions, of idle dreams and warring opinions, each having the same claims to our acceptance. Wide as is the distance between the material and the moral world; shadowy as all reasonings necessarily are which attempt to carry the inferences of one into the other; elevated above the region of matter as all the principles and grounds of truth must be, which belong to our responsibilities and hopes; still the astronomical and natural philosopher can hardly fail to draw from their studies an imperturbable conviction that our moral nature cannot correspond to those representations according to which it has no law, coherency, or object. The mere natural reasoner may, or must stop far short of all that it is his highest interest to know, his first duty to pursue; but even he, if he take any elevated and comprehensive views of his own subject, must escape from the opinions, as unphilosophical as they are comfortless, which would expel from our view of the world all reference to duty and moral good, all reliance on the most universal grounds of trust and hope. Men’s belief of their duty, and of the reasons for practising it, connected as it is with the conviction of a personal relation to their Maker, and of His power of superintendence and reward, is as manifest a fact in the moral, as any that can be pointed out is in the natural world. By mere analogy which has been intimated, therefore, we cannot but conceive that this fact belongs in some manner or other to the order of the moral world, and of its government. When any one acknowledges a moral governor of the world; perceives that domestic and social relations are perpetually operating and seem intended to operate, to retain and direct men in the path of duty; and feels that the voice of conscience, the peace of heart which results from a course of virtue, and the consolations of devotion, are ever ready to assume their office as our guides and aids in the conduct of all our actions;--he will probably be willing to acknowledge also that the means of moral government are not wanting, and will no longer be oppressed or disturbed by the apprehension that the superintendence of the world may be too difficult for its Ruler, and that any of His subjects and servants may be overlooked. He will no more fear that the moral than that the physical laws of God’s creation should be forgotten in any particular case: and as he knows that every sparrow which falls to the ground contains in its structure innumerable marks of the Divine care and kindness, he will be persuaded that every individual, however apparently humble and insignificant, will have his moral being dealt with according to the laws of God’s wisdom and love; will be enlightened, supported, and raised, if he use the appointed means which God’s administration of the world of moral light and good offers to his use. CHAPTER IV. _On the Impression produced by the Contemplation of Laws of Nature; or, on the Conviction that Law implies Mind._ The various trains of thought and reasoning which lead men from a consideration of the natural world to the conviction of the existence, the power, the providence of God, do not require, for the most part, any long or laboured deduction, to give them their effect on the mind. On the contrary, they have, in every age and country, produced their impression on multitudes who have not instituted any formal reasonings upon the subject, and probably upon many who have not put their conclusions in the shape of any express propositions. The persuasion of a superior intelligence and will, which manifests itself in every part of the material world, is, as is well known, so widely diffused and deeply infixed, as to have made it a question among speculative men whether the notion of such a power is not universal and innate. It is our business to show only how plainly and how universally such a belief results from the study of the appearances about us. That in many nations, in many periods, this persuasion has been mixed up with much that was erroneous and perverse in the opinions of the intellect or the fictions of fancy, does not weaken the force of such consent. The belief of a supernatural and presiding power runs through all these errors: and while the perversions are manifestly the work of caprice and illusion, and vanish at the first ray of sober inquiry, the belief itself is substantial and consistent, and grows in strength upon every new examination. It was the firmness and solidity of the conviction of _something_ Divine which gave a hold and permanence to the figments of so many false divinities. And those who have traced the progress of human thought on other subjects, will not think it strange, that while the fundamental persuasion of a Deity was thus irremovably seated in the human mind, the developement of this conception into a consistent, pure, and steadfast belief in one Almighty and Holy Father and God, should be long missed, or never attained, by the struggle of the human faculties; should require long reflection to mature it, and the aid of revelation to establish it in the world. The view of the universe which we have principally had occasion to present to the reader, is that in which we consider its appearances as reducible to certain fixed and general laws. Availing ourselves of some of the lights which modern science supplies, we have endeavoured to show that the adaptation of such laws to each other, and their fitness to promote the harmonious and beneficial course of the world, may be traced, wherever we can discover the laws themselves; and that the conceptions of the Divine Power, Goodness and Superintendence which we thus form, agree in a remarkable manner with the views of the Supreme Being, to which reason, enlightened by the divine revelation, has led. But we conceive that the general impressions of mankind would go further than a mere assent to the argument as we have thus stated it. To most persons it appears that the mere existence of a law connecting and governing any class of phenomena, implies a presiding intelligence which has preconceived and established the law. When events are regulated by precise rules of time and space, of number and measure, men conceive these rules to be the evidence of thought and mind, even without discovering in the rules any peculiar adaptations, or without supposing their purpose to be known. The origin and the validity of such an impression on the human mind may appear to some matters of abstruse and doubtful speculation: yet the tendency to such a belief prevails strongly and widely, both among the common class of minds whose thoughts are casually and unsystematically turned to such subjects, and among philosophers to whom laws of nature are habitual subjects of contemplation. We conceive therefore that such a tendency may deserve to be briefly illustrated; and we trust also that some attention to this point may be of service in throwing light upon the true relation of the study of nature to the belief in God. 1. A very slight attention shows us how readily order and regularity suggest to a common apprehension the operation of a calm and untroubled intelligence presiding over the course of events. Thus the materialist poet, in accounting for the belief in the Gods, though he does not share it, cannot deny the habitual effect of this manifestation. Præterea cœli rationes _ordine certo_ Et _varia_ annorum cernebant _tempora_ vorti; Nec poterant quibus id fieret cognoscere caussis. Ergo perfugium sibi habebant Omnia Divis Tradere et illorum nutu facere omnia flecti. LUCRET. v. 1182. They saw the skies in constant order run, The varied seasons and the circling sun, Apparent rule, with unapparent cause, And thus they sought in Gods the source of laws. The same feeling may be traced in the early mythology of a large portion of the globe. We might easily, taking advantage of the labours of learned men, exemplify this in the case of the oriental nations, of Greece, and of many other countries. Nor does there appear much difficulty in pointing out the error of those who have maintained that all religion had its _origin_ in the worship of the stars and the elements; and who have insinuated that all such impressions are unfounded, inasmuch as these are certainly not right objects of human worship. The religious feeling, the conviction of a supernatural power, of an intelligence connecting and directing the phenomena of the world, had not its _origin_ in the worship of sun, or stars, or elements; but was itself the necessary though unexpressed foundation of all worship, and all forms of false, as well as true, religion. The contemplation of the earth and heavens called into action this religious tendency in man; and to say that the worship of the material world formed or suggested this religious feeling, is to invert the order of possible things in the most unphilosophical manner. Idolatry is not the source of the belief in God, but is a compound of the persuasion of a supernatural government, with certain extravagant and baseless conceptions as to the manner in which this government is exercised. We will quote a passage from an author who has illustrated at considerable length the hypothesis that all religious belief is derived from the worship of the elements. “Light, and darkness its perpetual contrast; the succession of days and nights, the periodical order of the seasons; the career of the brilliant luminary which regulates their course; that of the moon his sister and rival; night, and the innumerable fires which she lights in the blue vault of heaven; the revolutions of the stars, which exhibit them for a longer or a shorter period above our horizon; the constancy of this period in the fixed stars, its variety in the wandering stars, the planets; their direct and retrograde course, their momentary rest; the phases of the moon waxing, full, waning, divested of all light; the progressive motion of the sun upwards, downwards; the successive order of the rising and setting of the fixed stars, which mark the different points of the course of the sun, while the various aspects which the earth itself assumes mark, here below also, the same periods of the sun’s annual motion; * * * all these different pictures, displayed before the eyes of man, formed the great and magnificent spectacle by which I suppose him surrounded at the moment when _he is about to create his gods_.”[31] What is this (divested of its wanton levity of expression) but to say, that when man has so far traced the course of nature as to be irresistibly impressed with the existence of order, law, variety in constancy, and fixity in change; of relations of form and space, duration and succession, cause and consequence, among the objects which surround him; there springs up in his breast, unbidden and irresistibly, the thought of superintending intelligence, of a mind which comprehended from the first and completely that which he late and partially comes to know? The worship of earth and sky, of the host of heaven and the influences of nature, is not the ultimate and fundamental fact in the early history of the religious impressions of mankind. These are but derivative streams, impure and scanty, from the fountain of religious feeling which appears to be disclosed to us by the contemplation of the universe, as the seat of law and the manifestation of intellect. Time suggests to man the thought of eternity; space of infinity; law of intelligence; order of purpose; and however difficult and long a task it may be to develope these suggestions into clear convictions, these thoughts are the real parents of our natural religious belief. The only relation between true religion and the worship of the elemental world is, that the latter is the partial and gross perversion, the former the consistent and pure developement of the same original idea. 2. The connexion of the laws of the material world with an intelligence which preconceived and instituted the law, which is thus, as we perceive, so generally impressed on the common apprehension of mankind, has also struck no less those who have studied nature with a more systematic attention, and with the peculiar views which belong to science. The laws which such persons learn and study, seem, indeed, most naturally to lead to the conviction of an intelligence which originally gave to the law its form. What we call a general law is, in truth, a form of expression including a number of facts of like kind. The facts are separate; the unity of view by which we associate them, the character of generality and of law, resides in those relations which are the object of the intellect. The law once apprehended by us, takes in our minds the place of the facts themselves, and is said to _govern_ or determine them, because it determines our anticipations of what they will be. But we cannot, it would seem, conceive a law, founded on such intelligible relations, to govern and determine the facts themselves, any otherwise than by supposing also an intelligence by which these relations are contemplated, and these consequences realized. We cannot then represent to ourselves the universe governed by general laws otherwise than by conceiving an intelligent and conscious Deity, by whom these laws were originally contemplated, established, and applied. This perhaps will appear more clear, when it is considered that the laws of which we speak are often of an abstruse and complex kind, depending upon relations of space, time, number, and other properties, which we perceive by great attention and thought. These relations are often combined so variously and curiously, that the most subtle reasonings and calculations which we can form are requisite in order to trace their results. Can such laws be conceived to be instituted without any exercise of knowledge and intelligence? Can material objects apply geometry and calculation to themselves? Can the lenses of the eye, for instance, be formed and adjusted with an exact suitableness to their refractive powers, while there is in the agency which has framed them, no consciousness of the laws of light, of the course of rays, of the visible properties of things? This appears to be altogether inconceivable. Every particle of matter possesses an almost endless train of properties, each acting according to its peculiar and fixed laws. For every atom of the same kind of matter these laws are invariably and perpetually the same, while for the different kinds of matter the difference of these properties is equally constant. This constant and precise resemblance, this variation equally constant and equally regular, suggest irresistibly the conception of some cause, independent of the atoms themselves, by which their similarity and dissimilarity, the agreement and difference of their deportment under the same circumstances, have been determined. Such a view of the constitution of matter, as is observed by an eminent writer of our own time, effectually destroys the idea of its eternal and self-existent nature, “by giving to each of its atoms the essential characters, at once, of a _manufactured article_ and a _subordinate agent_.”[32] That such an impression, and the consequent belief in a divine Author of the universe, by whom its laws were ordained and established, does result from the philosophical contemplation of nature, will, we trust, become still more evident by tracing the effect produced upon men’s minds by the discovery of such laws and properties as those of which we have been speaking; and we shall therefore make a few observations on this subject. CHAPTER V. _On Inductive Habits; or, on the Impression produced on Men’s Minds by discovering Laws of Nature._ The object of physical science is to discover such laws and properties as those of which we have spoken in the last chapter. In this task, undoubtedly a progress has been made on which we may well look with pleasure and admiration; yet we cannot hesitate to confess that the extent of our knowledge on such subjects bears no proportion to that of our ignorance. Of the great and comprehensive laws which rule over the widest provinces of natural phenomena, few have yet been disclosed to us. And the names of the philosophers, whose high office it has been to detect such laws, are even yet far from numerous. In looking back at the path by which science has advanced to its present position, we see the names of the great discoverers shine out like luminaries, few and scattered along the line: by far the largest portion of the space is occupied by those whose comparatively humble office it was to verify, to develope, to apply the general truths which the discoverers brought to light. It will readily be conceived that it is no easy matter, if it be possible, to analyse the process of thought by which laws of nature have thus been discovered; a process which, as we have said, has been in so few instances successfully performed. We shall not here make any attempt at such an analysis. But without this, we conceive it may be shown that the constitution and employment of the mind on which such discoveries depend, are friendly to that belief in a wise and good Creator and Governor of the world, which it has been our object to illustrate and confirm. And if it should appear that those who see further than their fellows into the bearings and dependencies of the material things and elements by which they are surrounded, have also been, in almost every case, earnest and forward in acknowledging the relation of all things to a supreme intelligence and will; we shall be fortified in our persuasion that the true scientific perception of the general constitution of the universe, and of the mode in which events are produced and connected, is fitted to lead us to the conception and belief of God. Let us consider for a moment what takes place in the mind of a student of nature when he attains to the perception of a law previously unknown, connecting the appearances which he has studied. A mass of facts which before seemed incoherent and unmeaning, assume, on a sudden, the aspect of connexion and intelligible order. Thus, when Kepler discovered the law which connects the periodic times with the diameters of the planetary orbits; or, when Newton showed how this and all other known mathematical properties of the solar system were included in the law of universal gravitation according to the inverse square of the distance; particular circumstances which, before, were merely matter of independent record, became, from that time, indissolubly conjoined by the laws so discovered. The separate occurrences and facts, which might hitherto have seemed casual and without reason, were now seen to be all exemplifications of the same truth. The change is like that which takes place when we attempt to read a sentence written in difficult or imperfect characters. For a time the separate parts appear to be disjointed and arbitrary marks; the suggestions of possible meanings, which succeed each other in the mind, fail, as fast as they are tried, in combining or accounting for these symbols: but at last the true supposition occurs; some words are found to coincide with the meaning thus assumed; the whole line of letters appear to take definite shapes and to leap into their proper places; and the truth of the happy conjecture seems to flash upon us from every part of the inscription. The discovery of laws of nature, truly and satisfactorily connecting and explaining phenomena, of which, before, the connexion and causes had been unknown, displays much of a similar process, of obscurity succeeded by evidence, of effort and perplexity followed by conviction and repose. The innumerable conjectures and failures, the glimpses of light perpetually opening and as often clouded over, the unwearied perseverance and inexhaustible ingenuity exercised by Kepler in seeking for the laws which he finally discovered, are, thanks to his communicative disposition, curiously exhibited in his works, and have been narrated by his biographers; and such efforts and alternations, modified by character and circumstances, must generally precede the detection of any of the wider laws and dependencies by which the events of the universe are regulated. We may readily conceive the satisfaction and delight with which, after this perplexity and struggle, the discoverer finds himself in light and tranquillity; able to look at the province of nature which has been the subject of his study, and to read there an intelligible connexion, a sufficing reason, which no one before him had understood or apprehended. This step so much resembles the mode in which one intelligent being understands and apprehends the conceptions of another, that we cannot be surprised if those persons in whose minds such a process has taken place, have been most ready to acknowledge the existence and operation of a superintending intelligence, whose ordinances it was their employment to study. When they had just read a sentence of the table of the laws of the universe, they could not doubt whether it had had a legislator. When they had deciphered there a comprehensive and substantial truth, they could not believe that the letters had been thrown together by chance. They could not but readily acknowledge that what their faculties had enabled them to read, must have been written by some higher and profounder mind. And accordingly, we conceive it will be found, on examining the works of those to whom we owe our knowledge of the laws of nature, and especially of the wider and more comprehensive laws, that such persons have been strongly and habitually impressed with the persuasion of a Divine Purpose and Power which had regulated the events which they had attended to, and ordained the laws which they had detected. To those who have pursued science without reaching the rank of discoverers;--who have possessed a derivative knowledge of the laws of nature which others had disclosed, and have employed themselves in tracing the consequences of such laws, and systematizing the body of truth thus produced, the above description does not apply; and we have not therefore in these cases the same ground for anticipating the same frame of mind. If among men of science of this class, the persuasion of a supreme Intelligence has at some periods been less vivid and less universal, than in that higher class of which we have before spoken, the fact, so far as it has existed, may perhaps be in some degree accounted for. But whether the view which we have to give of the mental peculiarities of men whose science is of this derivative kind be well founded, and whether the account we have above offered of that which takes place in the minds of original discoverers of laws in scientific researches be true, or not, it will probably be considered a matter of some interest to point out historically that in fact, such discoverers have been peculiarly in the habit of considering the world as the work of God. This we shall now proceed to do. As we have already said, the names of _great_ discoverers are not very numerous. The sciences which we may look upon as having reached or at least approached their complete and finished form, are Mechanics, Hydrostatics, and Physical Astronomy. Galileo is the father of modern Mechanics; Copernicus, Kepler, and Newton are the great names which mark the progress of Astronomy. Hydrostatics shared in a great measure the fortunes of the related science of Mechanics; Boyle and Pascal were the persons mainly active in developing its more peculiar principles. The other branches of knowledge which belong to natural philosophy, as Chemistry and Meteorology, are as yet imperfect, and perhaps infant sciences; and it would be rash to presume to select, in them, names of equal preeminence with those above mentioned: but it may not be difficult to show, with sufficient evidence, that the effect of science upon the authors of science is, in these subjects as in the former ones, far other than to alienate their minds from religious trains of thought, and a habit of considering the world as the work of God. We shall not dwell much on the first of the above mentioned great names, Galileo; for his scientific merit consisted rather in adopting the sound philosophy of others, as in the case of the Copernican system, and in combating prevalent errors, as in the case of the Aristotelian doctrines concerning motion, than in any marked and prominent discovery of new principles. Moreover the mechanical laws which he had a share in bringing to light, depending as they did, rather on detached experiments and transient facts, than on observation of the general course of the universe, could not so clearly suggest any reflection on the government of the world at that period, as they did afterwards when Newton showed their bearing on the cosmical system. Yet Galileo, as a man of philosophical and inventive mind, who produced a great effect on the progress of physical knowledge, is a person whose opinions must naturally interest us, engaged in our present course of reasoning. There is in his writings little which bears upon religious views, as there is in the nature of his works little to lead him to such subjects. Yet strong expressions of piety are not wanting, both in his letters, and in his published treatises. The persecution which he underwent, on account of his writings in favour of the Copernican system, was grounded, not on his opposition to the general truths of natural religion, which is our main concern at present, nor even on any supposed rejection of any articles of Christian faith, but on the alleged discrepancy between his adopted astronomical views and the declarations of scripture. Some of his remarks may interest the reader. In his third dialogue on the Copernican system he has occasion to speak of the opinion which holds all parts of the world to be framed for man’s use alone: and to this he says, “I would that we should not so shorten the arm of God in the government of human affairs; but that we should rest in this, that we are certain that God and nature are so occupied in the government of human affairs, that they could not more attend to us if they were charged with the care of the human race alone.” In the same spirit, when some objected to the asserted smallness of the Medicean stars, or satellites of Jupiter, and urged this as a reason why they were unworthy the regard of philosophers, he replied that they are the works of God’s power, the objects of His care, and therefore may well be considered as sublime subjects for man’s study. In the Dialogues on Mechanics, there occur those observations concerning the use of the air-bladder in fishes, and concerning the adaptation of the size of animals to the strength of the materials of which they are framed, which have often since been adopted by writers on the wisdom of Providence. The last of the dialogues on the system of the world is closed by a religious reflection, put in the mouth of the interlocutor who usually expresses Galileo’s own opinions. “While it is permitted us to speculate concerning the constitution of the world, we are also taught (perhaps in order that the activity of the human mind may not pause or languish) that our powers do not enable us to comprehend the works of His hands. May success therefore attend this intellectual exercise, thus permitted and appointed for us; by which we recognize and admire the greatness of God the more, in proportion as we find ourselves the less able to penetrate the profound abysses of his wisdom.” And that this train of thought was habitual to the philosopher we have abundant evidence in many other parts of his writings. He had already said in the same dialogue, “Nature (or God, as he elsewhere speaks) employs means in an admirable and inconceivable manner; admirable, that is, and inconceivable to us, but not to her, who brings about with consummate facility and simplicity things which affect our intellect with infinite astonishment. That which is to us most difficult to understand is to her most easy to execute.” The establishment of the Copernican and Newtonian views of the motions of the solar system and their causes, were probably the occasions on which religious but unphilosophical men entertained the strongest apprehensions that the belief in the government of God may be weakened when we thus “thrust some mechanic cause into his place.” It is therefore fortunate that we can show, not only that this ought not to occur, from the reason of the thing, but also that in fact the persons who are the leading characters in the progress of these opinions were men of clear and fervent piety. In the case of Copernicus himself it does not appear that, originally, any apprehensions were entertained of any dangerous discrepancy between his doctrines and the truths of religion, either natural or revealed. The work which contains these memorable discoveries was addressed to Pope Paul III., the head, at that time, (1543) of the religious world; and was published, as the author states in the preface, at the urgent entreaty of friends, one of whom was a cardinal, and another a bishop.[33] “I know,” he says, “that the thoughts of a philosopher are far removed from the judgment of the vulgar; since it is his study to search out truth in all things, as far as that is permitted by God to human reason.” And though the doctrines are for the most part stated as portions of a mathematical calculation, the explanation of the arrangement by which the sun is placed in the centre of the system is accompanied by a natural reflection of a religious cast; “Who in this fair temple would place this lamp in any other or better place than there whence it may illuminate the whole? We find then under this ordination an admirable symmetry of the world, and a certain harmonious connexion of the motion and magnitude of the orbs, such as in any other way cannot be found. Thus the progressions and regressions of the planets all arise from the same cause, the motion of the earth. And that no such movements are seen in the fixed stars, argues their immense distance from us, which causes the apparent magnitude of the earth’s annual course to become evanescent. So great, in short, is this divine fabric of the great and good God;”[34] “this best and most regular artificer of the universe,” as he elsewhere speaks. Kepler was the person, who by further studying “the connexion of the motions and magnitude of the orbs,” to which Copernicus had thus drawn the attention of the astronomers, detected the laws of this connexion, and prepared the way for the discovery, by Newton, of the mechanical laws and causes of such motions. Kepler was a man of strong and lively piety; and the exhortation which he addresses to his reader before entering on the exposition of some of his discoveries, may be quoted not only for its earnestness but its reasonableness also. “I beseech my reader, that not unmindful of the divine goodness bestowed on man, he do with me praise and celebrate the wisdom and greatness of the Creator, which I open to him from a more inward explication of the form of the world, from a searching of causes, from a detection of the errors of vision: and that thus, not only in the firmness and stability of the earth he perceive with gratitude the preservation of all living things in nature as the gift of God, but also that in its motion, so recondite, so admirable, he acknowledge the wisdom of the Creator. But him who is too dull to receive this science, or too weak to believe the Copernican system without harm to his piety, him, I say, I advise that, leaving the school of astronomy, and condemning, if he please, any doctrines of the philosophers, he follow his own path, and desist from this wandering through the universe, and lifting up his natural eyes, with which alone he can see, pour himself out from his own heart in praise of God the Creator; being certain that he gives no less worship to God than the astronomer, to whom God has given to see more clearly with his inward eye, and who, for what he has himself discovered, both can and will glorify God.” The next great step in our knowledge of the universe, the discovery of the mechanical causes by which its motions are produced, and of their laws, has in modern times sometimes been supposed, both by the friends of religion and by others, to be unfavourable to the impression of an intelligent first cause. That such a supposition is founded in error we have offered what appear to us insurmountable reasons for believing. That in the mind of the great discoverer of this mechanical cause, Newton, the impression of a creating and presiding Deity was confirmed, not shaken, by all his discoveries, is so well known that it is almost superfluous to insist upon the fact. His views of the tendency of science invested it with no dangers of this kind. “The business of natural philosophy is,” he says, (Optics, Qu. 28,) “to argue from phenomena without feigning hypotheses, and to deduce cause from effects, till we come to the very first cause, which is certainly not mechanical.” “Though every true step made in this philosophy brings us not immediately to the knowledge of the first cause, yet it brings us nearer to it, and is on that account highly to be valued.” The Scholium, or note, which concludes his great work, the Principia, is a well known and most striking evidence on this point, “This beautiful system of sun, planets, and comets, could have its origin in no other way than by the purpose and command of an intelligent and powerful Being. He governs all things, not as the soul of the world, but as the lord of the universe. He is not only God, but Lord or Governor. We know him only by his properties and attributes, by the wise and admirable structure of things around us, and by their final causes; we admire him on account of his perfections, we venerate and worship him on account of his government.” Without making any further quotations, it must be evident to the reader that the succession of great philosophers through whom mankind have been led to the knowledge of the greatest of scientific truths, the law of universal gravitation, did, for their parts, see the truths which they disclosed to men in such a light that their religious feelings, their reference of the world to an intelligent Creator and Preserver, their admiration of his attributes, were exalted rather than impaired by the insight which they obtained into the structure of the universe. Having shown this with regard to the most perfect portion of human knowledge, our knowledge of the motions of the solar system, we shall adduce a few other passages, illustrating the prevalence of the same fact in other departments of experimental science; although, for reasons which have already been intimated, we conceive that sciences of experiment do not conduct so obviously as sciences of observation to the impression of a Divine Legislator of the material world. The science of Hydrostatics was constructed in a great measure by the founders of the sister science of Mechanics. Of those who were employed in experimentally establishing the principles peculiarly belonging to the doctrine of fluids, Pascal and Boyle are two of the most eminent names. That these two great philosophers were not only religious, but both of them remarkable for their fervent and pervading devotion, is too well known to be dwelt on. With regard to Pascal, however, we ought not perhaps to pass over an opinion of his, that the existence of God cannot be proved from the external world. “I do not undertake to prove this,” says he, “not only because I do not feel myself sufficiently strong to find in nature that which shall convince obstinate atheists, but because such knowledge without Jesus Christ is useless and steril.” It is obvious that such a state of mind would prevent this writer from encouraging or dwelling upon the grounds of natural religion; while yet he himself is an example of that which we wish to illustrate, that those who have obtained the furthest insight into nature, have been in all ages firm believers in God. “Nature,” he says, in another place, “has perfections in order to show that she is the image of God, and defects in order to show that she is only his image.”[35] Boyle was not only a most pious man as well as a great philosopher, but he exerted himself very often and earnestly in his writings to show the bearing of his natural philosophy upon his views of the Divine attributes, and of the government of the world. Many of these dissertations convey trains of thought and reasoning which have never been surpassed for their combination of judicious sobriety in not pressing his arguments too far, with fervent devotion in his conceptions of the Divine nature. As examples of these merits, we might adduce almost any portion of his tracts on these subjects; for instance, his “Inquiry into the Final Causes of Natural Things;” his “Free Inquiry into the Vulgar Notion of Nature;” his “Christian Virtuoso;” and his essay entitled “The High Veneration Man’s Intellect owes to God.” It would be superfluous to quote at any length from these works. We may observe, however, that he notices that general fact which we are at present employed in exemplifying, that “in almost all ages and countries the generality of philosophers and contemplative men were persuaded of the existence of a Deity from the consideration of the phenomena of the universe; whose fabric and conduct they rationally concluded could not justly be ascribed either to chance or to any other cause than a Divine Being.” And in speaking of the religious uses of science, he says: “Though I am willing to grant that some impressions of God’s wisdom are so conspicuous that even a superficial philosopher may thence infer that the author of such works must be a wise agent; yet how wise an agent he has in these works expressed himself to be, none but an experimental philosopher can well discern. And ’tis not by a slight survey, but by a diligent and skilful scrutiny, of the works of God, that a man must be, by a rational and affective conviction, engaged to acknowledge that the author of nature ‘is wonderful in counsel, and excellent in working.’” After the mechanical properties of fluids, the laws of the operation of the chemical and physical properties of the elements about us, offer themselves to our notice. The relations of heat and of moisture in particular, which play so important a part, as we have seen, in the economy of our world, have been the subject of various researches; and they have led to views of the operation of such agents, some of which we have endeavoured to present to the reader, and to point out the remarkable arrangements by which their beneficial operation is carried on. That the discoverers of the laws by which such operations are regulated, were not insensible to the persuasion of a Divine care and contrivance which those arrangements suggest, is what we should expect, in agreement with what we have already said, and it is what we find. Among the names of the philosophers to whom we owe our knowledge on these subjects, there are none greater than those of Black, the discoverer of the laws of latent heat, and Dalton, who first gave us a true view of the mode in which watery vapour exists and operates in the atmosphere. With regard to the former of these philosophers, we shall quote Dr. Thomson’s account of the views which the laws of latent heat suggested to the discoverer.[36] “Dr. Black quickly perceived the vast importance of this discovery, and took a pleasure in laying before his students a view of the beneficial effects of this habitude of heat in the economy of nature. During the summer season a vast magazine of heat is accumulated in the water, which by gradually emerging during congelation serves to temper the cold of winter. Were it not for this accumulation of heat in water and other bodies, the sun would no sooner go a few degrees to the south of the equator than we should feel all the horrors of winter.” In the same spirit are Mr. Dalton’s reflections, after pointing out the laws which regulate the balance of evaporation and rain,[37] which he himself first clearly explained. “It is scarcely possible,” says he, “to contemplate without admiration the beautiful system of nature by which the surface of the earth is continually supplied with water, and that unceasing circulation of a fluid so essentially necessary to the very being of the animal and vegetable kingdom takes place.” Such impressions appear thus to rise irresistibly in the breasts of men, when they obtain a sight, for the first time, of the varied play and comprehensive connexions of the laws by which the business of the material world is carried on and its occurrences brought to pass. To dwell upon or develope such reflections is not here our business. Their general prevalence in the minds of those to whom these first views of new truths are granted, has been, we trust, sufficiently illustrated. Nor are the names adduced above, distinguished as they are, brought forwards as _authorities_ merely. We do not claim for the greatest discoverers in the realms of science any immunity from error. In their general opinions they may, as others may, judge or reason ill. The articles of their religious belief may be as easily and as widely as of other men’s, imperfect, perverted, unprofitable. But on this one point, the tendency of our advances in scientific knowledge of the universe to lead us up to a belief in a most wise maker and master of the universe, we conceive that they who make these advances, and who feel, as an original impression, that which others feel only by receiving their teaching, must be looked to with a peculiar attention and respect. And what their impressions have commonly been, we have thus endeavoured to show. CHAPTER VI. _On Deductive Habits; or, on the Impression produced on Men’s Minds by tracing the consequences of ascertained Laws._ The opinion illustrated in the last chapter, that the advances which men make in science tend to impress upon them the reality of the Divine government of the world, has often been controverted. Complaints have been made, and especially of late years, that the growth of piety has not always been commensurate with the growth of knowledge, in the minds of those who make nature their study. Views of an irreligious character have been entertained, it is sometimes said, by persons eminently well instructed in all the discoveries of modern times, no less than by the superficial and ignorant. Those who have been supposed to deny or to doubt the existence, the providence, the attributes of God, have in many cases been men of considerable eminence and celebrity for their attainments in science. The opinion that this is the case, appears to be extensively diffused, and this persuasion has probably often produced inquietude and grief in the breasts of pious and benevolent men. This opinion, concerning the want of religious convictions among those who have made natural philosophy their leading pursuit, has probably gone far beyond the limits of the real fact. But if we allow that there are any strong cases to countenance such an opinion, it may be worth our while to consider how far they admit of any satisfactory explanation. The fact appears at first sight to be at variance with the view we have given of the impression produced by scientific discovery; and it is moreover always a matter of uneasiness and regret, to have men of eminent talents and knowledge opposed to doctrines which we consider as important truths. We conceive that an explanation of such cases, if they should occur, may be found in a very curious and important circumstance belonging to the process by which our physical sciences are formed. The first discovery of new general truths, and the developement of these truths when once obtained, are two operations extremely different; imply different mental habits, and may easily be associated with different views and convictions on points out of the reach of scientific demonstration. There would therefore be nothing surprising, or inconsistent with what we have maintained above, if it should appear that while original discoverers of laws of nature are peculiarly led, as we have seen, to believe the existence of a supreme intelligence and purpose; the far greater number of cultivators of science, whose employment it is to learn from others these general laws, and to trace, combine, and apply their consequences, should have no clearness of conviction or security from error on this subject, beyond what belongs to persons of any other class. This will, perhaps, become somewhat more evident by considering a little more closely the distinction of the two operations of discovery and developement, of which we have spoken above, and the tendency which the habitual prosecution of them may be expected to produce in the thoughts and views of the student. We have already endeavoured in some measure to describe that which takes place when a new law of nature is discovered. A number of facts in which, before, order and connexion did not appear at all, or appeared by partial and contradictory glimpses, are brought into a point of view in which order and connexion become their essential character. It is seen that each fact is but a different manifestation of the same principle; that each particular is that which it is, in virtue of the same general truth. The inscription is deciphered; the enigma is guessed; the principle is understood; the truth is enunciated. When this step is once made, it becomes possible to deduce from the truth thus established, a train of consequences often in no small degree long and complex. The process of making these inferences may properly be described by the word Deduction, while the very different process by which a new principle is collected from an assemblage of facts, has been termed Induction; the truths so obtained and their consequences constitute the results of the Inductive Philosophy; which is frequently and rightly described as a science which ascends from particular facts to general principles, and then descends again from these general principles to particular applications and exemplifications. While the great and important labours by which science is really advanced consist in the successive steps of the _inductive_ ascent in the discovery of new laws perpetually more and more general; by far the greater part of our books of physical science unavoidably consists in _deductive_ reasoning, exhibiting the consequences and applications of the laws which have been discovered; and the greater part of writers upon science have their minds employed in this process of deduction and application. This is true of many of those who are considered, and justly, as distinguished and profound philosophers. In the mechanical philosophy, that science which applies the properties of matter and the laws of motion to the explanation of the phenomena of the world, this is peculiarly the case. The laws, when once discovered, occupy little room in their statement, and when no longer contested, are not felt to need a lengthened proof. But their consequences require far more room and far more intellectual labour. If we take, for example, the laws of motion and the law of universal gravitation, we can express in a few lines, that which, when developed, represents and explains an innumerable mass of natural phenomena. But here the course of developement is necessarily so long, the reasoning contains so many steps, the considerations on which it rests are so minute and refined, the complication of cases and of consequences is so vast, and even the involution arising from the properties of space and number so serious, that the most consummate subtlety, the most active invention, the most tenacious power of inference, the widest spirit of combination, must be tasked and tasked severely, in order to solve the problems which belong to this portion of science. And the persons who have been employed on these problems, and who have brought to them the high and admirable qualities which such an office requires, have justly excited in a very eminent degree the admiration which mankind feel for great intellectual powers. Their names occupy a distinguished place in literary history; and probably there are no scientific reputations of the last century higher, and none more merited, than those earned by the great mathematicians who have laboured with such wonderful success in unfolding the mechanism of the heavens; such for instance as D’Alembert, Clairault, Euler, Lagrange, Laplace. But it is still important to recollect, that the mental employments of men, while they are occupied in this portion of the task of the formation of science, are altogether different from that which takes place in the mind of a discoverer, who, for the first time, seizes the principle which connects phenomena before unexplained, and thus adds another original truth to our knowledge of the universe. In explaining, as the great mathematicians just mentioned have done, the phenomena of the solar system by means of the law of universal gravitation, the conclusions at which they arrived were really included in the truth of the law itself, whatever skill and sagacity it might require to develope and extricate them from the general principle. But when Newton conceived and established the law itself, he added to our knowledge something which was not contained in any truth previously known, nor deducible from it by any course of mere reasoning. And the same distinction, in all other cases, obtains, between these processes which establish the principles, generally few and simple, on which our sciences rest, and those reasonings and calculations, founded on the principles thus obtained, which constitute by far the larger portion of the common treatises on the most complete of the sciences now cultivated. Since the difference is so great between the process of inductive generalization of physical facts, and that of mathematical deduction of consequences, it is not surprising that the two processes should imply different mental powers and habits. However rare the mathematical talent, in its highest excellence, may be, it is far more common, if we are to judge from the history of science, than the genius which divines the general laws of nature. We have several good mathematicians in every age; we have few great discoverers in the whole history of our species. The distinction being thus clearly established between original discovery and derivative speculation, between the ascent to principles and the descent from them, we have further to observe, that the habitual and exclusive prosecution of the latter process may sometimes exercise an unfavourable effect on the mind of the student, and may make him less fitted and ready to apprehend and accept truths different from those with which his reasonings are concerned. We conceive, for example, that a person labours under gross error, who believes the phenomena of the world to be altogether produced by mechanical causes, and who excludes from his view all reference to an intelligent First Cause and Governor. But we conceive that reasons may be shown which make it more probable that error of such a kind should find a place in the mind of a person of deductive, than of inductive habits;--of a mere mathematician or logician, than of one who studies the facts of the natural world and detects their laws. The person whose mind is employed in reducing to law and order and intelligible cause the complex facts of the material world, is compelled to look beyond the present state of his knowledge, and to turn his thoughts to the existence of principles higher than those which he yet possesses. He has seen occasions when facts that at first seemed incoherent and anomalous, were reduced to rule and connexion; and when limited rules were discovered to be included in some rule of superior generality. He knows that all facts and appearances, all partial laws, however confused and casual they at present seem, must still, in reality, have this same kind of bearing and dependence;--must be bound together by some undiscovered principle of order;--must proceed from some cause working by most steady rules;--must be included in some wide and fruitful general truth. He cannot therefore consider any principles which he has already obtained, as the ultimate and sufficient reason of that which he sees. There must be some higher principle, some ulterior reason. The effort and struggle by which he endeavours to extend his view, makes him feel that there is a region of truth not included in his present physical knowledge; the very imperfection of the light in which he works his way, suggests to him that there must be a source of clearer illumination at a distance from him. We must allow that it is scarcely possible to describe in a manner free from some vagueness and obscurity, the effect thus produced upon the mind by the efforts which it makes to reduce natural phenomena to general laws. But we trust it will still be allowed that there is no difficulty in seeing clearly that a different influence may result from this process, and from the process of deductive reasoning which forms the main employment of the mathematical cultivators and systematic expositors of physical science in modern times. Such persons are not led by their pursuits to any thing beyond the general principles, which form the basis of their explanations and applications. They acquiesce in these; they make these their ultimate grounds of truth; and they are entirely employed in unfolding the particular truths which are involved in the general truth. Their thoughts dwell little upon the possibility of the laws of nature being other than we find them to be, or on the reasons why they are not so; and still less on those facts and phenomena which philosophers have not yet reduced to any rule; which are lawless to us, though we know that, in reality, they are governed by some principle of order and harmony. On the contrary, by assuming perpetually the existing laws as the basis of their reasoning, without question or doubt, and by employing such language that these laws can be expressed in the simplest and briefest form, they are led to think and believe as if these laws were necessarily and inevitably what they are. Some mathematicians indeed have maintained that the highest laws of nature with which we are acquainted, the laws of motion and the law of universal gravitation, are not only necessarily true, but are even self-evident and certain _à priori_, like the truths of geometry. And though the mathematical cultivator of the science of mechanics may not adopt this as his speculative opinion, he may still be so far influenced by the tendency from which it springs, as to rest in the mechanical laws of the universe as ultimate and all-sufficient principles, without seeing in them any evidence of their having been selected and ordained, and thus without ascending from the world to the thought of an Intelligent Ruler. He may thus substitute for the Deity certain axioms and first principles, as the cause of all. And the follower of Newton may run into the error with which he is sometimes charged, of thrusting some mechanic cause into the place of God, if he do not raise his views, as his master did, to some higher cause, to some source of all forces, laws, and principles. When, therefore, we consider the mathematicians who are employed in successfully applying the mechanical philosophy, as men well deserving of honour from those who take an interest in the progress of science, we do rightly; but it is still to be recollected, that in doing this they are not carrying us to any higher point of view in the knowledge of nature than we had attained before: they are only unfolding the consequences, which were already virtually in our possession, because they were implied in principles already discovered:--they are adding to our knowledge of effects, but not to our knowledge of causes:--they are not making any advance in that progress of which Newton spoke, and in which he made so vast a stride, in which “every step made brings us nearer to the knowledge of the first cause, and is on that account highly to be valued.” And as in this advance they have no peculiar privileges or advantages, their errors of opinion concerning it, if they err, are no more to be wondered at, than those of common men; and need as little disturb or distress us, as if those who committed them had confined themselves to the study of arithmetic or of geometry. If we can console and tranquillize ourselves concerning the defective or perverted views of religious truth entertained by any of our fellow men, we need find no additional difficulty in doing so when those who are mistaken are great mathematicians, who have added to the riches and elegance of the mechanical philosophy. And if we are seeking for extraneous grounds of trust and comfort on this subject, we may find them in the reflection;--that, whatever may be the opinions of those who assume the causes and laws of that philosophy and reason from them, the views of those admirable and ever-honoured men who first caught sight of these laws and causes, impressed _them_ with the belief that this is “the fabric of a great and good God;” that “it is man’s duty to pour out his soul in praise of the Creator;” and that all this beautiful system must be referred to “a first cause, which is certainly not mechanical.” 2. We may thus, with the greatest propriety, deny to the mechanical philosophers and mathematicians of recent times any authority with regard to their views of the administration of the universe; we have no reason whatever to expect from their speculations any help, when we attempt to ascend to the first cause and supreme ruler of the universe. But we might perhaps go further, and assert that they are in some respects less likely than men employed in other pursuits, to make any clear advance towards such a subject of speculation. Persons whose thoughts are thus entirely occupied in deduction are apt to forget that this is, after all, only one employment of the reason among more; only one mode of arriving at truth, needing to have its deficiencies completed by another. Deductive reasoners, those who cultivate science, of whatever kind, by means of mathematical and logical processes alone, may acquire an exaggerated feeling of the amount and value of their labours. Such employments, from the clearness of the notions involved in them, the irresistible concatenation of truths which they unfold, the subtlety which they require, and their entire success in that which they attempt, possess a peculiar fascination for the intellect. Those who pursue such studies have generally a contempt and impatience of the pretensions of all those other portions of our knowledge, where from the nature of the case, or the small progress hitherto made in their cultivation, a more vague and loose kind of reasoning seems to be adopted. Now if this feeling be carried so far as to make the reasoner suppose that these mathematical and logical processes can lead him to all the knowledge and all the certainty which we need, it is clearly a delusive feeling. For it is confessed on all hands, that all which mathematics or which logic can do, is to develope and extract those truths, as conclusions, which were in reality involved in the principles on which our reasonings proceeded.[38] And this being allowed, we cannot but ask how we obtain these principles? from what other source of knowledge we derive the original truths which we thus pursue into detail? since it is manifest that such principles cannot be derived from the proper stores of mathematics or logic. These methods can generate no new truth; and all the grounds and elements of the knowledge which, through them, we can acquire, must necessarily come from some extraneous source. It is certain, therefore, that the mathematician and the logician must derive from some process different from their own, the substance and material of all our knowledge, whether physical or metaphysical, physiological or moral. This process, by which we acquire our first principles, (without pretending here to analyse it,) is obviously the general course of human experience, and the natural exercise of the understanding; our intercourse with matter and with men, and the consequent growth in our minds of convictions and conceptions such as our reason can deal with, either by her systematic or unsystematic methods of procedure. Supplies from this vast and inexhaustible source of original truths are requisite, to give any value whatever to the results of our deductive processes, whether mathematical or logical; while on the other hand, there are many branches of our knowledge, in which we possess a large share of original and derivative convictions and truths, but where it is nevertheless at present quite impossible to erect our knowledge into a complete system;--to state our primary and independent truths, and to show how on these all the rest depend by the rules of art. If the mathematician is repelled from speculations on morals or politics, on the beautiful or the right, because the reasonings which they involve have not mathematical precision and conclusiveness, he will remain destitute of much of the most valuable knowledge which man can acquire. And if he attempts to mend the matter by giving to treatises on morals, or politics, or criticism, a form and a phraseology borrowed from the very few tolerably complete physical sciences which exist, it will be found that he is compelled to distort and damage the most important truths, so as to deprive them of their true shape and import, in order to force them into their places in his artificial system. If therefore, as we have said, the mathematical philosopher dwells in his own bright and pleasant land of deductive reasoning, till he turns with disgust from all the speculations, necessarily less clear and conclusive, in which his imagination, his practical faculties, his moral sense, his capacity of religious hope and belief, are to be called into action, he becomes, more than common men, liable to miss the road to truths of extreme consequence. This is so obvious, that charges are frequently brought against the study of mathematics, as unfitting men for those occupations which depend upon our common instinctive convictions and feelings, upon the unsystematic exercise of the understanding with regard to common relations and common occurrences. Bonaparte observed of Laplace, when he was placed in a public office of considerable importance, that he did not discharge it in so judicious and clear sighted a manner as his high intellectual fame might lead most persons to expect.[39] “He sought,” that great judge of character said, “subtleties in every subject, and carried into his official employments the spirit of the method of infinitely small quantities,” by which the mathematician solves his more abstruse problems. And the complaint that mathematical studies make men insensible to moral evidence and to poetical beauties, is so often repeated as to show that some opposition of tendency is commonly perceived between that exercise of the intellect which mathematics requires and those processes which go on in our minds when moral character or imaginative beauty is the subject of our contemplation. Thus, while we acknowledge all the beauty and all the value of the mathematical reasonings by which the consequences of our general laws are deduced, we may yet consider it possible that a philosopher, whose mind has been mainly employed, and his intellectual habits determined, by this process of deduction, may possess, in a feeble and imperfect degree only, some of those faculties by which truth is attained, and especially those truths which regard our relation to that mind, the origin of all law, the source of first principles, which must be immeasurably elevated above all derivative truths. It would, therefore, be far from surprising, if there should be found, among the great authors of the developements of the mechanical philosophy, some who had refused to refer the phenomena of the universe to a supreme mind, purpose, and will. And though this world be, to a believer in the Being and government of God, a matter of sorrow and pain, it need not excite more surprise than if the same were true of a person of the most ordinary endowments, when it is recollected in what a disproportionate manner the various faculties of such a philosopher may have been cultivated. And our apprehensions of injury to mankind from the influence of such examples will diminish, when we consider, that those mathematicians whose minds have been less partially exercised, the great discoverers of the truths which others apply, the philosophers who have looked upwards as well as downwards, to the unknown as well as to the known, to ulterior as well as proximate principles, have never rested in this narrow and barren doctrine; but have perpetually looked forwards, beyond mere material laws and causes, to a First Cause of the moral and material world, to which each advance in philosophy might bring them nearer, though it must ever remain indefinitely beyond their reach. It scarcely needs, perhaps, to be noticed, that what we here represent as the possible source of error is, not the perfection of the mathematical habits of the mind, but the deficiency of the habit of apprehending truth of other kinds;--not a clear insight into the mathematical consequences of principles, but a want of a clear view of the nature and foundation of principles;--not the talent for generalizing geometrical or mechanical relations, but the tendency to erect such relations into ultimate truths and efficient causes. The most consummate mathematical skill may accompany and be auxiliary to the most earnest piety, as it often has been. And an entire command of the conceptions and processes of mathematics is not only consistent with, but is the necessary condition and principal instrument of every important step in the discovery of physical principles. Newton was eminent above the philosophers of his time, in no one talent so much as in the power of mathematical deduction. When he had caught sight of the law of universal gravitation, he traced it to its consequences with a rapidity, a dexterity, a beauty of mathematical reasoning which no other person could approach; so that on this account, if there had been no other, the establishment of the general law was possible to him alone. He still stands at the head of mathematicians as well as of philosophical discoverers. But it never appeared to him, as it may have appeared to some mathematicians who have employed themselves on his discoveries, that the general law was an ultimate and sufficient principle: that the point to which he had hung his chain of deduction was the highest point in the universe. Lagrange, a modern mathematician of transcendent genius, was in the habit of saying, in his aspirations after future fame, that Newton was fortunate in having had the system of the world for his problem, since its theory could be discovered once only. But Newton himself appears to have had no such persuasion that the problem he had solved was unique and final: he laboured to reduce gravity to some higher law, and the forces of other physical operations to an analogy with those of gravity, and declared that all these were but steps in our advance towards a first cause. Between us and this first cause, the source of the universe and of its laws, we cannot doubt that there intervene many successive steps of possible discovery and generalization, not less wide and striking than the discovery of universal gravitation: but it is still more certain that no extent or success of physical investigation can carry us to any point which is not at an immeasurable distance from an adequate knowledge of Him. CHAPTER VII. _On Final Causes._ We have pointed out a great number of instances where the mode in which the arrangements of nature produce their effect, suggests, as we conceive, the belief that this effect is to be considered as the _end_ and _purpose_ of these arrangements. The impression which thus arises, of design and intention exercised in the formation of the world, or of the reality of _Final Causes_, operates on men’s minds so generally, and increases so constantly on every additional examination of the phenomena of the universe, that we cannot but suppose such a belief to have a deep and stable foundation. And we conceive that in several of the comparatively few cases in which such a belief has been rejected, the averseness to it has arisen from the influence of some of the causes mentioned in the last chapter; the exclusive pursuit, namely, of particular trains and modes of reasoning, till the mind becomes less capable of forming the conceptions and making the exertions which are requisite for the apprehension of truths not included among its usual subjects of thought. 1. This seems to be the case with those who maintain that purpose and design cannot be _inferred_ or _deduced_ from the arrangements which we see around us by any process of reasoning. We can reason from effects to causes, say such writers, only in cases where we know something of the nature of the cause. We can infer from the works of men, the existence of design and purpose, because we know, from past observation, what kind of works human design and purpose can produce. But the universe, considered as the work of God, cannot be compared with any corresponding work, or judged of by any analogy with known examples. How then can we, in this case, they ask, infer design and purpose in the artist of the universe? On what principles, on what axioms, can we proceed, which shall include this necessarily singular instance, and thus give legitimacy and validity to our reasonings? What has already been said on the subject of the two different processes by which we obtain principles, and by which we reason from them, will suggest the reply to these questions. When we collect design and purpose from the arrangements of the universe, we do not arrive at our conclusion by a train of deductive reasoning, but by the conviction which such combinations as we perceive immediately and directly impress upon the mind. “Design must have had a designer.” But such a principle can be of no avail to one whom the contemplation or the description of the world does not impress with the perception of design. It is not, therefore, at the end, but at the beginning of our syllogisms, not among remote conclusions, but among original principles, that we must place the truth, that such arrangements, manifestations, and proceedings as we behold about us imply a Being endowed with consciousness, design, and will, from whom they proceed. This is inevitably the mode in which such a conviction is acquired; and that it is so, we may the more readily believe, when we consider that it is the case with the design and will which we ascribe to man, no less than in that which we believe to exist in God. At first sight we might perhaps be tempted to say, that we infer design and purpose from the works of man in one case, because we have known these attributes in other cases produce effects in some measure similar. But to this we must reply, by asking how we come to know the existence of human design and purpose _at first_, and _at all_? What we see around us are certain appearances, things, successions of events; how come we ever to ascribe to other men the thought and will of which we are conscious ourselves? How do we come to believe that there are other men? How are we led to elevate, in our conceptions, some of the _objects_ which we perceive into _persons_? No doubt their actions, their words induce us to do this. We see that the manifestations which we observe must be so understood, and not otherwise. We feel that such actions, such events must be connected by consciousness and personality; that the actions are not the actions of things, but of persons; not necessary and without significance, like the falling of a stone, but voluntary and with purpose like what we do ourselves. But this is not a result of reasoning: we do not infer this from any similar case which we have known; since we are now speaking of the _first_ conception of a will and purpose different from our own. In arriving at such knowledge, we are aided only by our own consciousness of what thought, purpose, will, are: and possessing this regulative principle, we so decipher and interpret the complex appearances which surround us, that we receive irresistibly the persuasion of the existence of other men, with thought and will and purpose like our own. And just in the same manner, when we examine attentively the adjustment of the parts of the human frame to each other and to the elements, the relation of the properties of the earth to those of its inhabitants, or of the physical to the moral nature of man, the thought must arise and cling to our perceptions, however little it be encouraged, that this system, every where so full of wonderful combinations, suited to the preservation, and well-being of living creatures, is also the expression of the intention, wisdom, and goodness of a personal creator and governor. We conceive then that it is so far from being an unsatisfactory or unphilosophical process by which we collect the existence of a Deity from the works of creation, that the process corresponds most closely with that on which rests the most steadfast of our convictions, next to that of our own existence, the belief of the existence of other human beings. If any one ever went so far in scepticism as to doubt the existence of any other person than himself, he might, so far as the argument from final causes is concerned, reject the being of God as well as that of man; but, without dwelling on the possibility of such fantasies, when we consider how impossible it is for men in general not to attribute personality, purpose, thought, will to each other, in virtue of certain combinations of appearances and actions, we must deem them most consistent and reasonable in attributing also personality and purpose to God, in virtue of the whole assemblage of appearances and actions which constitute the universe, full as it is of combinations from which such a suggestion springs. The vividness, the constancy of the belief of a wise and good Being, thus governing the world, may be different in different men, according to their habit of directing their thoughts to the subject; but such a belief is undoubtedly capable of becoming lively and steadfast in the highest degree. It has been entertained and cherished by enlightened and well-regulated minds in all ages; and has been, at least since the rise of Christianity, not only the belief, but a pervading and ruling principle of action of many men, and of whole communities. The idea may be rendered more faint by turning the mind away from it, and perhaps by indulging too exclusively in abstract and general speculations. It grows stronger by an actual study of the details of the creation; and, as regards the practical consequences of such a belief, by a habit of referring our actions and hopes to such a Governor. In this way it is capable of becoming as real and fixed an impression as that of a human friend and master; and all that we can learn, by observing the course of men’s feelings and actions, tends to convince us, that this belief of the being and presence and government of God, leads to the most elevated and beneficial frame of mind of which man is capable. 2. How natural and almost inevitable is this persuasion of the reality of Final Causes and consequent belief in the personality of the Deity, we may gather by observing how constantly it recurs to the thoughts, even of those who, in consequence of such peculiarities of mental discipline as have been described, have repelled and resisted the impression. Thus, Laplace, of whom we have already spoken, as one of the greatest mathematicians of modern times, expresses his conviction that the supposed evidence of final causes will disappear as our knowledge advances, and that they only seem to exist in those cases where our ignorance leaves room for such a mistake. “Let us run over,” he says, “the history of the progress of the human mind and its errors: we shall perpetually see final causes pushed away to the bounds of its knowledge. These causes, which Newton removed to the limits of the solar system, were not long ago conceived to obtain in the atmosphere, and employed in explaining meteors: they are, therefore, in the eyes of the philosopher nothing more than the expression of the ignorance in which we are of the real causes.” We may observe that we have endeavoured to give a very different, and, as we believe, a far truer view of the effect which philosophy has produced on our knowledge of final causes. We have shown, we trust, that the notion of design and end is transferred by the researches of science, not from the domain of our knowledge to that of our ignorance, but merely from the region of facts to that of laws. We hold that, in this form, final causes in the atmosphere are still to be conceived to obtain, no less than in an earlier state of meteorological knowledge; and that Newton was right, when he believed that he had established their reality in the solar system, not expelled them from it. But our more peculiar business at present is to observe that Laplace himself, in describing the arrangements by which the stability of the solar system is secured, uses language which shows how irresistibly these arrangements suggest an adaptation to its preservation as an _end_. If in his expressions we were to substitute the Deity for the abstraction “nature” which he employs, his reflection would coincide with that which the most religious philosopher would entertain. “It seems that ‘God’ has ordered every thing in the heavens to ensure the duration of the planetary system, by _views_ similar to those which He appears to us so admirably to follow upon the earth, for the preservation of animals and the perpetuity of species.[40] This consideration alone would explain the disposition of the system, if it were not the business of the geometer to go further.” It may be possible for the geometer to go further; but he must be strangely blinded by his peculiar pursuits, if, when he has discovered the mode in which these views are answered, he supposes himself to have obtained a proof that there are no views at all. It would be as if the savage, who had marvelled at the steady working of the steam engine, should cease to consider it a work of art, as soon as the self-regulating part of the mechanism had been explained to him. The unsuccessful struggle in which those persons engage, who attempt to throw off the impression of design in the creation, appears in an amusing manner through the simplicity of the ancient Roman poet of this school. Lucretius maintains that the eye was not made for seeing, nor the ear for hearing. But the terms in which he recommends this doctrine show how hard he knew it to be for men to entertain such an opinion. His advice is,-- Illud in his rebus vitium _vehementer_ et istum Effugere errorem, vitareque _præmeditator_, Lumina ne facias oculorum clara creata, Prospicere ut possimus. iv. 823. ’Gainst their preposterous error guard thy mind Who say each organ was for use design’d; Think not the visual orbs, so clear, so bright, Were furnish’d for the purposes of sight. Undoubtedly the poet is so far right, that a most “vehement” caution and vigilant “premeditation” are necessary to avoid the “vice and error” of such a persuasion. The study of the adaptations of the human frame is so convincing, that it carries the mind with it, in spite of the resistance suggested by speculative systems. Cabanis, a modern French physiological writer of great eminence, may be selected as a proof of this. Both by the general character of his own speculations, and by the tone of thinking prevalent around him, the consideration of design in the works of nature was abhorrent from his plan. Accordingly, he joins in repeating Bacon’s unfavourable mention of final causes. Yet when he comes to speak of the laws of reproduction of the human race, he appears to feel himself compelled to admit the irresistible manner in which such views force themselves on the mind. “I regard,” he says, “with the great Bacon, the philosophy of final causes as barren; but I have elsewhere acknowledged that it was very difficult for the most cautious man (l’homme le plus reservé) never to have recourse to them in his explanations.”[41] 3. It may be worth our while to consider for a moment the opinion here referred to by Cabanis, of the propriety of excluding the consideration of final causes from our natural philosophy. The great authority of Bacon is usually adduced on this subject. “The handling of final causes,” says he, “mixed with the rest in physical inquiries, hath intercepted the severe and diligent inquiry of all real and physical causes, and given men the occasion to stay upon these satisfactory and specious causes, to the great arrest and prejudice of farther discovery.”[42] A moment’s attention will show how well this representation agrees with that which we have urged, and how far it is from dissuading the reference to final causes in reasonings like those on which we are employed. Final causes are to be excluded _from physical inquiry_; that is, we are not to assume that we know the objects of the Creator’s design, and put this assumed purpose in the place of a physical cause. We are not to think it a sufficient account of the clouds that they are for watering the earth, (to take Bacon’s examples,) or “that the solidness of the earth is for the station and mansion of living creatures.” The physical philosopher has it for his business to trace clouds to the laws of evaporation and condensation; to determine the magnitude and mode of action of the forces of cohesion and crystallization by which the materials of the earth are made solid and firm. This he does, making no use of the notion of final causes: and it is precisely because he has thus established his theories independently of any assumption of an end, that the end, when after all, it returns upon him and cannot be evaded, becomes an irresistible evidence of an intelligent legislator. He finds that the effects, of which the use is obvious, are produced by most simple and comprehensive laws; and when he has obtained this view, he is struck by the beauty of the means, by the refined and skilful manner in which the useful effects are brought about;--points different from those to which his researches were directed. We have already seen, in the very case of which we have been speaking, namely, the laws by which the clouds are formed and distribute their showers over the earth, how strongly those who have most closely and extensively examined the arrangements there employed (as Howard, Dalton, and Black) have been impressed with the harmony and beauty which these contrivances manifest. We may find a further assertion of this view of the proper use of final causes in philosophy, by referring to the works of one of the greatest of our philosophers, and one of the most pious of our writers, Boyle, who has an Essay on this subject. “I am by all means,” says he, “for encouraging the contemplation of the celestial part of the world, and the shining globes that adorn it, and especially the sun and moon, in order to raise our admiration of the stupendous power and wisdom of him who was able to frame such immense bodies; and notwithstanding their vast bulk and scarce conceivable rapidity, keep them for so many ages constant both to the lines and degrees of their motion, without interfering with one another. And doubtless we ought to return thanks and praises to the divine goodness for having so placed the sun and moon, and determined the former, or else the earth, to move in particular lines for the good of men and other animals; and how disadvantageous it would have been to the inhabitants of the earth if the luminaries had moved after a different manner. I dare not, however, affirm that the sun, moon, and other celestial bodies were made solely for the use of man: _much less presume to prove one system of the world to be true and another false; because the former is better fitted to the convenience of mankind, or the other less suited, or perhaps altogether useless to that end_.” This passage exhibits, we conceive, that combination of feelings which ought to mark the character of the religious natural philosopher; an earnest piety ready to draw nutriment from the contemplation of established physical truths; joined with a philosophical caution, which is not seduced by the anticipation of such contemplations, to pervert the strict course of physical inquiry. It is precisely through this philosophical care and scrupulousness that our views of final causes acquire their force and value as aids to religion. The object of such views is not to lead us to physical truth, but to connect such truth, obtained by its proper processes and methods, with our views of God, the master of the universe, through those laws and relations which are thus placed beyond dispute. Bacon’s comparison of final causes to the vestal virgins is one of those poignant sayings, so frequent in his writings, which it is not easy to forget. “Like them,” he says, “they are dedicated to God, and are barren.” But to any one who reads his work it will appear in what spirit this was meant. “Not because those final causes are not true and worthy to be inquired, being kept within their own province.” (Of the Advancement of Learning, b. ii. p. 142.) If he had had occasion to develope his simile, full of latent meaning as his similes so often are, he would probably have said, that to these final causes barrenness was no reproach, seeing they ought to be, not the mothers but the daughters of our natural sciences; and that they were barren, not by imperfection of their nature but in order that they might be kept pure and undefiled, and so fit ministers in the temple of God. CHAPTER VIII. _On the Physical Agency of the Deity._ 1. We are not to expect that physical investigation can enable us to conceive the manner in which God acts upon the members of the universe. The question, “Canst thou by searching find out God?” must silence the boastings of science as well as the repinings of adversity. Indeed, science shows us, far more clearly than the conceptions of every day reason, at what an immeasurable distance we are from any faculty of conceiving _how_ the universe, material and moral, is the work of the Deity. But with regard to the material world, we can at least go so far as this;--we can perceive that events are brought about, not by insulated interpositions of divine power exerted in each particular case, but by the establishment of general laws. This, which is the view of the universe proper to science, whose office it is to search out these laws, is also the view which, throughout this work, we have endeavoured to keep present to the mind of the reader. We have attempted to show that it combines itself most readily and harmoniously with the doctrines of Natural Theology; that the arguments for those doctrines are strengthened, the difficulties which affect them removed, by keeping it steadily before us. We conceive, therefore, that the religious philosopher will do well to bear this conception in his mind. God is the author and governor of the universe through the laws which he has given to its parts, the properties which he has impressed upon its constituent elements; these laws and properties are, as we have already said, the instruments with which he works; the institution of such laws, the selection of the quantities which they involve, their combination and application, are the modes in which he exerts and manifests his power, his wisdom, his goodness: through these attributes, thus exercised, the Creator of all, shapes, moves, sustains, and guides the visible creation. This has been the view of the relation of the Deity to the universe entertained by the most sagacious and comprehensive minds ever since the true object of natural philosophy has been clearly and steadily apprehended. The great writer who was the first to give philosophers a distinct and commanding view of this object, thus expresses himself in his “Confession of Faith:” “I believe--that notwithstanding God hath rested and ceased from creating since the first Sabbath, yet, nevertheless, he doth accomplish and fulfil his divine will in all things, great and small, singular and general, as fully and exactly by providence, as he could by miracle and new creation, though his working be not immediate and direct, but by compass; not violating nature, which is his own law upon the creature.” And one of our own time, whom we can no longer hesitate to place among the worthiest disciples of the school of Bacon, conveys the same thought in the following passage: “The Divine Author of the universe cannot be supposed to have laid down particular laws, enumerating all individual contingencies, which his materials have understood and obey--this would be to attribute to him the imperfections of human legislation;--but rather, by creating them endued with certain fixed qualities and powers, he has impressed them in their origin with the _spirit_, not the letter of his law, and made all their subsequent combinations and relations inevitable consequences of this first impression.”[43] 2. This, which thus appears to be the mode of the Deity’s operation in the material world, requires some attention on our part in order to understand it with proper clearness. One reason of this is, that it is a mode of operation altogether different from that in which we are able to make matter fulfil our designs. Man can construct exquisite machines, can call in vast powers, can form extensive combinations, in order to bring about results which he has in view. But in all this he is only taking advantage of laws of nature which already exist; he is applying to his use qualities which matter already possesses. Nor can he by any effort do more. He can establish no new law of nature which is not a result of the existing ones. He can invest matter with no new properties which are not modifications of its present attributes. His greatest advances in skill and power are made when he calls to his aid forces which before existed unemployed, or when he discovers so much of the habits of some of the elements as to be able to bend them to his purpose. He navigates the ocean by the assistance of the winds which he cannot raise or still: and even if we suppose him able to control the course of these, his yet unsubjugated ministers, this could only be done by studying their characters, by learning more thoroughly the laws of air and heat and moisture. He cannot give the minutest portion of the atmosphere new relations, a new course of expansion, new laws of motion. But the Divine operations, on the other hand, include something much higher. They take in the establishment of the laws of the elements, as well as the combination of these laws and the determination of the distribution and quantity of the materials on which they shall produce their effect. We must conceive that the Supreme Power has ordained that air shall be rarefied, and water turned into vapour, by heat; no less than that he has combined air and water so as to sprinkle the earth with showers, and determined the quantity of heat and air and water, so that the showers shall be as beneficial as they are. We may and must, therefore, in our conceptions of the Divine purpose and agency, go beyond the analogy of human contrivances. We must conceive the Deity, not only as constructing the most refined and vast machinery, with which, as we have already seen, the universe is filled; but we must also imagine him as establishing those properties by which such machinery is possible: as giving to the materials of his structure the qualities by which the material is fitted to its use. There is much to be found, in natural objects, of the same kind of contrivance which is common to these and to human inventions; there are mechanical devices, operations of the atmospheric elements, chemical processes;--many such have been pointed out, many more exist. But besides these cases of the combination of means, which, we seem able to understand without much difficulty, we are led to consider the Divine Being as the _author of the laws_ of chemical, of physical, and of mechanical action, and of such other laws as make matter what it is;--and this is a view which no analogy of human inventions, no knowledge of human powers, at all assists us to embody or understand. Science, therefore, as we have said, while it discloses to us the mode of instrumentality employed by the Deity, convinces us, more effectually than ever, of the impossibility of conceiving God’s actions by assimilating them to our own. 3. The laws of material nature, such as we have described them, operate at all times, and in all places; affect every province of the universe, and involve every relation of its parts. Wherever these laws appear, we have a manifestation of the intelligence by which they were established. But a law supposes an agent, and a power; for it is the mode according to which the agent proceeds, the order according to which the power acts. Without the presence of such an agent, of such a power, conscious of the relations on which the law depends, producing the effects which the law prescribes, the law can have no efficacy, no existence. Hence we infer that the intelligence by which the law is ordained, the power by which it is put in action, must be present at all times and in all places where the effects of the law occur; that thus the knowledge and the agency of the Divine Being pervade every portion of the universe, producing all action and passion, all permanence and change. The laws of nature are the laws which he, in his wisdom, prescribes to his own acts; his universal presence is the necessary condition of any course of events, his universal agency the only origin of any efficient force. This view of the relation of the universe to God has been entertained by many of the most eminent of those who have combined the consideration of the material world with the contemplation of God himself. It may therefore be of use to illustrate it by a few quotations, and the more so, as we find this idea remarkably dwelt upon in the works of that writer whose religious views must always have a peculiar interest for the cultivators of physical science, the great Newton. Thus, in the observations on the nature of the Deity with which he closes the “Opticks,” he declares the various portions of the world, organic and inorganic, “can be the effect of nothing else than the wisdom and skill of a powerful ever living Agent, who being in all places, is more able by his will to move the bodies within his boundless uniform _sensorium_, and thereby to form and reform the parts of the universe, than we are by our will to move the parts of our own bodies.” And in the Scholium at the end of the “Principia,” he says, “God is one and the same God always and every where. He is omnipresent, not by means of his _virtue_ alone, but also by his _substance_, for virtue cannot subsist without substance. In him all things are contained, and move, but without mutual passion: God is not acted upon by the motions of bodies; and they suffer no resistance from the omnipresence of God.” And he refers to several passages confirmatory of this view, not only in the Scriptures, but also in writers who hand down to us the opinions of some of the most philosophical thinkers of the pagan world. He does not disdain to quote the poets, and among the rest, the verses of Virgil; Principio cœlum ac terras camposque liquentes Lucentemque globum lunæ, Titaniaque astra, Spiritus intus alit, totamque infusa per artus Mens agitat molem et magno se corpore miscet: warning his reader, however, against the doctrine which such expressions as these are sometimes understood to express. “All these things he rules, not as _the soul of the world_, but as the Lord of all.” Clarke, the friend and disciple of Newton, is one of those who has most strenuously put forwards the opinion of which we are speaking, “All things which we commonly say are the effects of the natural powers of matter and laws of motion, are indeed (if we will speak strictly and properly,) the effects of God’s acting upon matter continually and at every moment, either immediately by himself, or mediately by some created intelligent being. Consequently there is no such thing as the course of nature, or the power of nature,” independent of the effects produced by the will of God. Dugald Stewart has adopted and illustrated the same opinion, and quotes with admiration the well-known passage of Pope, concerning the Divine Agency, which “Lives through all life, extends through all extent, Spreads undivided, operates unspent.” Mr. Stewart, with no less reasonableness than charity, asserts the propriety of interpreting such passages according to the scope and spirit of the reasonings with which they are connected;[44] since, though by a captious reader they might be associated with erroneous views of the Deity, a more favourable construction will often see in them only the results of the necessary imperfection of our language, when we dwell upon the omnipresence and universal activity of God. Finally, we may add that the same opinions still obtain the assent of the best philosophers and divines of our time. Sir John Herschel says, (Discourse on the Study of Natural Philosophy, p. 37.) “We would no way be understood to deny the constant exercise of His direct power in maintaining the system of nature; or the ultimate emanation, of every energy which material agents exert, from his immediate will, acting in conformity with his own laws.” And the Bishop of London, in a note to his “Sermon on the duty of combining religious instruction with intellectual culture,” observes, “the student in natural philosophy will find rest from all those perplexities which are occasioned by the obscurity of causation, in the supposition, which although it was discredited by the patronage of Malebranche and the Cartesians, has been adopted by Clarke and Dugald Stewart, and which is by far the most simple and sublime account of the matter; that all the events, which are continually taking place in the different parts of the material universe, are the _immediate_ effects of the divine agency.” CHAPTER IX. _On the Impression produced by considering the Nature and Prospects of Science; or, on the Impossibility of the Progress of our Knowledge ever enabling us to comprehend the Nature of the Deity._ If we were to stop at the view presented in the last chapter, it might be supposed that--by considering God as eternal and omnipresent, conscious of all the relations, and of all the objects of the universe, instituting laws founded on the contemplation of these relations, and carrying these laws into effect by his immediate energy,--we had attained to a conception, in some degree definite, of the Deity, such as natural philosophy leads us to conceive him. But by resting in this mode of conception, we should overlook, or at least should disconnect from our philosophical doctrines, all that most interests and affects us in the character of the Creator and Preserver of the world;--namely, that he is the lawgiver and judge of our actions; the proper object of our prayer and adoration; the source from which we may hope for moral strength here, and for the reward of our obedience and the elevation of our nature in another state of existence. We are very far from believing that our philosophy alone can give us such assurance of these important truths as is requisite for our guidance and support; but we think that even our physical philosophy will point out to us the necessity of proceeding far beyond that conception of God, which represents him merely as the mind in which reside all the contrivance, law, and energy of the material world. We believe that the view of the universe which modern science has already opened to us, compared with the prospect of what she has still to do in pursuing the path on which she has just entered, will show us how immeasurably inadequate such a mode of conception would be: and that if we take into our account, as we must in reason do, all that of which we have knowledge and consciousness, and of which we have as yet no systematic science, we shall be led to a conviction that the Creator and Preserver of the material world must also contain in him such properties and attributes as imply his moral character, and as fall in most consistently with all that we learn in any other way of his providence and holiness, his justice and mercy. 1. The sciences which have at present acquired any considerable degree of completeness, are those in which an extensive and varied collection of phenomena, and their proximate causes, have been reduced to a few simple general laws. Such are Astronomy and Mechanics, and perhaps, so far as its physical conditions are concerned, Optics. Other portions of human knowledge can be considered as perfect sciences, in any strict sense of the term, only when they have assumed this form; when the various appearances which they involve are reduced to a few principles, such as the laws of motion and the mechanical properties of the luminiferous ether. If we could trace the endless varieties of the forms of crystals, and the complicated results of chemical composition, to some one comprehensive law necessarily pointing out the crystalline form of any given chemical compound, Mineralogy would become an exact science. As yet, however, we can scarcely boast of the existence of any other such sciences than those which we at first mentioned: and so far therefore as we attempt to give definiteness to our conception of the Deity, by considering him as the intelligent depositary and executor of laws of nature, we can subordinate to such a mode of conception no portion of the creation, save the mechanical movements of the universe, and the propagation and properties of light. 2. And if we attempt to argue concerning the nature of the laws and relations which govern those provinces of creation whither our science has not yet reached, by applying some analogy borrowed from cases where it has been successful, we have no chance of attaining any except the most erroneous and worthless guesses. The history of human speculations, as well as the nature of the objects of them, shows how certainly this must happen. The great generalizations which have been established in one department of our knowledge, have been applied in vain to the purpose of throwing light on the other portions which still continue in obscurity. When the Newtonian philosophy had explained so many mechanical facts, by the two great steps,--of resolving the action of a whole mass into the actions of its minutest particles, and considering these particles as centres of force,--attempts were naturally soon made to apply the same mode of explanation to facts of other different kinds. It was conceived that the whole of natural philosophy must consist in investigating the laws of force by which particles of different substances attracted and repelled, and thus produced motions, or vibrations _to_ and _from_ the particles. Yet what were the next great discoveries in physics? The action of a galvanic wire upon a magnet; which is not to attract or repel it, but to turn it to the _right_ and _left_; to produce motion, not to or from, but _transverse_ to the line drawn to the acting particles; and again, the undulatory theory of light, in which it appeared that the undulations must not be longitudinal, as all philosophers, following the analogy of all cases previously conceived, had, at first, supposed them to be, but _transverse_ to the path of the ray. Here, though the step from the known to the unknown was comparatively small, when made conjecturally it was made in a direction very wide of the truth. How impossible then must it be to attain in this manner to any conception of a law which shall help us to understand the whole government of the universe! 3. Still, however, in the laws of the luminiferous ether, and of the other fluid, (if it be another fluid) by which galvanism and magnetism are connected, we have something approaching nearly to mechanical action, and, possibly, hereafter to be identified with it. But we cannot turn to any other part of our physical knowledge, without perceiving that the gulf which separates it from the exact sciences is yet wider and more obscure. Who shall enunciate for us, and in terms of what notions, the general law of _chemical_ composition and decomposition? sometimes indeed we give the name of _attraction_ to the affinity by which we suppose the particles of the various ingredients of bodies to be aggregated; but no one can point out any common feature between this and the attractions of which alone we know the exact effects. He who shall discover the true general law of the forces by which elements form compounds, will probably advance as far beyond the discoveries of Newton, as Newton went beyond Aristotle. But who shall say in what direction this vast flight shall be, and what new views it shall open to us of the manner in which matter obeys the laws of the Creator? 4. But suppose this flight performed;--we are yet but at the outset of the progress which must carry us towards Him. We have yet to begin to learn all that we are to know concerning the ultimate laws of organized bodies. What is the principle of _life_? What is the rule of that action of which assimilation, secretion, developement, are manifestations? and which appears to be farther removed from mere chemistry than chemistry is from mechanics. And what again is the new principle, as it seems to be, which is exhibited in the _irritability_ of an animal nerve? the existence of a sense? How different is this from all the preceding notions! No efforts can avoid or conceal the vast but inscrutable chasm. Those theorists, who have maintained most strenuously the possibility of tracing the phenomena of animal life to the influence of physical agents, have constantly been obliged to suppose a mode of agency altogether different from any yet known in physics. Thus Lamarck, one of the most noted of such speculators, in describing the course of his researches, says, “I was soon persuaded that the _internal sentiment_ constituted a power which it was necessary to take into account.” And Bichat, another writer on the same subject, while he declares his dissent from Stahl, and the earlier speculators, who had referred every thing in the economy of life to a single principle, which they called the _anima_, the _vital principle_, and so forth, himself introduces several principles, or laws, all utterly foreign to the region of physics; namely, _organic sensibility_, _organic contractility_, _animal sensibility_, _animal contractility_, and the like. Supposing such principles really to exist, how far enlarged and changed must our views be before we can conceive these properties, including the faculty of perception, which they imply, to be produced by the will and power of one supreme Being, acting by fixed laws. Yet without conceiving this, we cannot conceive the agency of that Deity, who is incessantly thus acting, in countless millions of forms and modes. How strongly then does science represent God to us as incomprehensible! his attributes as unfathomable! His power, his wisdom, his goodness, appear in each of the provinces of nature which are thus brought before us; and in each, the more we study them, the more impressive, the more admirable do they appear. When then we find these qualities manifested in each of so many successive ways, and each manifestation rising above the preceding by unknown degrees, and through a progression of unknown extent, what other language can we use concerning such attributes than that they are _infinite_? What mode of expression can the most cautious philosophy suggest, other than that He, to whom we thus endeavour to approach, is infinitely wise, powerful, and good? 5. But with sense and consciousness the history of living things only begins. They have instincts, affections, passions, will. How entirely lost and bewildered do we find ourselves when we endeavour to conceive these faculties communicated by means of general laws! Yet they are so communicated from God, and of such laws he is the lawgiver. At what an immeasurable interval is he thus placed above every thing which the creation of the inanimate world alone would imply; and how far must he transcend all ideas founded on such laws as we find there! 6. But we have still to go further and far higher. The world of reason and of morality is a part of the same creation, as the world of matter and of sense. The will of man is swayed by rational motives; its workings are inevitably compared with a rule of action; he has a conscience which speaks of right and wrong. These are laws of man’s nature no less than the laws of his material existence, or his animal impulses. Yet what entirely new conceptions do they involve? How incapable of being resolved into, or assimilated to, the results of mere matter, or mere sense! Moral good and evil, merit and demerit, virtue and depravity, if ever they are the subjects of strict science, must belong to a science which views these things, not with reference to time or space, or mechanical causation, not with reference to fluid or ether, nervous irritability or corporeal feeling, but to their own proper modes of conception; with reference to the relations with which it is possible that these notions may be connected, and not to relations suggested by other subjects of a completely extraneous and heterogeneous nature. And according to such relations must the laws of the moral world be apprehended, by any intelligence which contemplates them at all. There can be no wider interval in philosophy than the separation which must exist between the laws of mechanical force and motion, and the laws of free moral action. Yet the tendency of men to assume, in the portions of human knowledge which are out of their reach, a similarity of type to those with which they are familiar, can leap over even this interval. Laplace has asserted that “an intelligence which, at a given instant, should know all the forces by which nature is urged, and the respective situation of the beings of which nature is composed, if, moreover, it were sufficiently comprehensive to subject these data to calculation, would include in the same _formula_, the movements of the largest bodies of the universe and those of the slightest atom. Nothing would be uncertain to such an intelligence, and the future, no less than the past, would be present to its eyes.” If we speak merely of mechanical actions, this may, perhaps, be assumed to be an admissible representation of the nature of their connexion in the sight of the supreme intelligence. But to the rest of what passes in the world, such language is altogether inapplicable. A _formula_ is a brief mode of denoting a rule of calculating in which numbers are to be used: and numerical measures are applicable only to things of which the relation depend on time and space. By such elements, in such a mode, how are we to estimate happiness and virtue, thought and will? To speak of a formula with regard to such things, would be to assume that their laws must needs take the shape of those laws of the material world which our intellect most fully comprehends. A more absurd and unphilosophical assumption we can hardly imagine. We conceive, therefore, that the laws by which God governs his moral creatures, reside in his mind, invested with that kind of generality, whatever it be, of which such laws are capable; but of the character of such general laws, we know nothing more certainly than this, that it must be altogether different from the character of those laws which regulate the material world. The inevitable necessity of such a total difference is suggested by the analogy of all the knowledge which we possess and all the conceptions which we can form. And, accordingly, no persons, except those whose minds have been biassed by some peculiar habit or course of thought, are likely to run into the confusion and perplexity which are produced by assimilating too closely the government and direction of voluntary agents to the production of trains of mechanical and physical phenomena. In whatever manner voluntary and moral agency depend upon the Supreme Being, it must be in some such way that they still continue to bear the character of will, action, and morality. And, though too exclusive an attention to material phenomena may sometimes have made physical philosophers blind to this manifest difference, it has been clearly seen and plainly asserted by those who have taken the most comprehensive views of the nature and tendency of science. “I believe,” says Bacon, in his Confession of Faith, “that, at the first the soul of man was not produced by heaven or earth, but was breathed immediately from God; so that _the ways and proceedings of God with spirits are not included in nature; that is in the laws of heaven and earth_; but are reserved to the law of his secret will and grace; wherein God worketh still, and resteth not from the work of redemption, as he resteth from the work of creation; but continueth working to the end of the world.” We may be permitted to observe here, that, when Bacon has thus to speak of God’s dealings with his moral creatures, he does not take his phraseology from those sciences which can offer none but false and delusive analogies; but helps out the inevitable scantiness of our human knowledge, by words borrowed from a source more fitted to supply our imperfections. Our natural speculations cannot carry us to the ideas of “grace” and “redemption;” but in the wide blank which they leave, of all that concerns our hopes of the Divine support and favour, the inestimable knowledge which revelation, as we conceive, gives us, finds ample room and appropriate place. 7. Yet even in the view of our moral constitution which natural reason gives, we may trace laws that imply a personal relation to our Creator. How can we avoid considering _that_ as a true view of man’s being and place, without which, his best faculties are never fully developed, his noblest energies never called out, his highest point of perfection never reached? Without the thought of a God over all, superintending our actions, approving our virtues, transcending our highest conceptions of good, man would never rise to those higher regions of moral excellence which we know him to be capable of attaining. “To deny a God,” again says the great philosopher, “destroys magnanimity and the raising of human nature; for take an example of a dog, and mark what a generosity and courage he will put on, when he finds himself maintained by a man; who, to him, is instead of a God, or _melior natura_: which courage is manifestly such, as that creature, without that confidence of a better nature than his own, could never attain. So man, when he resteth and assureth himself upon divine protection and favour, gathereth a force and faith, which human nature could not obtain. Therefore, as atheism is in all respects hateful, so in this, that it depriveth human nature of the means to exalt itself above human frailty.”[45] Such a law, then, of reference to a Supremely Good Being, is impressed upon our nature, as the condition and means of its highest moral advancement. And strange indeed it would be if we should suppose, that in a system where all besides indicates purpose and design, this law should proceed from no such origin; and no less inconceivable, that such a law, purposely impressed upon man to purify and elevate his nature, should delude and deceive him. 8. Nothing remains, therefore, but that the Creator, who, for purposes that even we can see to be wise and good, has impressed upon man this tendency to look to him for support, for advancement, for such happiness as is reconcileable with holiness;--to believe him to be the union of all perfection, the highest point of all intellectual and moral excellence;--IS, in reality, such a guardian and judge, such a good, and wise, and perfect Being, as we thus irresistibly conceive him. It would indeed be extravagant to assert that the imagination of the creature, itself the work of God, can invent a higher point of goodness, of justice, of holiness, than the Creator himself possesses: that the Eternal Mind, from whom our notions of good and right are derived, is not himself directed by the rules which these notions imply. It is difficult to dwell steadily on such thoughts. But they will at least serve to confirm the view which it was our object to illustrate; namely, how incomparably the nature of God must be elevated above any conceptions which our natural reason enables us to form; and we have been led to these reflections, it will be recollected, by following the clue of which science gave us the beginning. The Divine Mind must be conceived by us as the seat of those laws of nature which we have discovered. It must be no less the seat of those laws which we have not yet discovered, though these may and must be of a character far different from any thing we can guess. The Supreme Intelligence must therefore contain the laws, each according to their true dependence, of organic life, of sense, of animal impulse, and must contain also the purpose and intent for which these powers were put in play. But the Governing Mind must comprehend also the laws of the responsible creatures which the world contains, and must entertain the purposes for which their responsible agency was given them. It must include these laws and purposes, connected by means of the notions, which responsibility implies, of desert and reward, of moral excellence in various degrees, and of well-being as associated with right doing. All the laws which govern the moral world are expressions of the thought and intentions of our Supreme Ruler. All the contrivances for moral no less than for physical good, for the peace of mind, and other rewards of virtue, for the elevation and purification of individual character, for the civilization and refinement of states, their advancement in intellect and virtue, for the diffusion of good, and the repression of evil; all the blessings that wait on perseverance and energy in a good cause; on unquenchable love of mankind, and unconquerable devotedness to truth; on purity and self-denial; on faith, hope, and charity;--all these things are indications of the character, will, and future intentions of that God, of whom we have endeavoured to track the footsteps upon earth, and to show his handiwork in the heavens. “This God is our God, for ever and ever.” And if, in endeavouring to trace the tendencies of the vast labyrinth of laws by which the universe is governed, we are sometimes lost and bewildered, and can scarce, or not at all, discern the line by which pain, and sorrow, and vice fall in with a scheme directed to the strictest right and greatest good, we yet find no room to faint or falter; knowing that these are the darkest and most tangled recesses of our knowledge; that into them science has as yet cast no ray of light; that in them reason has as yet caught sight of no general law by which we may securely hold: while, in those regions where we can see clearly, where science has thrown her strongest illumination upon the scheme of creation; where we have had displayed to us the general laws which give rise to all multifarious variety of particular facts;--we find all full wisdom, and harmony, and beauty: and all this wise selection of means, this harmonious combination of laws, this beautiful symmetry of relations, directed, with no exception which human investigation has yet discovered, to the preservation, the diffusion, the well-being of those living things, which, though of their nature we know so little, we cannot doubt to be the worthiest objects of the Creator’s care. FINIS. FOOTNOTES: [1] Loudon, Encyclopædia of Gardening, 848. [2] Dec. Phys. vol. ii. 478. [3] Fleming, Zool. i. 400. [4] Rapports du Physique et du Moral de l’Homme, II. 371. [5] It will be observed that it is not here asserted that the difference of native products depends on the difference of climate _alone_. [6] The resemblance consists in this; that we have a strip of greater temperature accompanied by a strip of smaller temperature, these strips arising from the diurnal and nocturnal impressions respectively, and being in motion; as in the waves on a canal, we have a moving strip of greater elevation accompanied by a strip of smaller elevation. We do not here refer to any hypothetical undulations in the fluid matter of heat. [7] Loudon, 1219. [8] Loudon, 1214. [9] Manchester Memoirs, v. 357. [10] Howard on the climate of London, vol. ii. pp. 216, 217. [11] Daniell, Meteor. Ess. p. 56. [12] Daniell. p. 129. [13] Phil. Trans. 1821. [14] Mr. Gough in Manch. Mem. vol. v. [15] The reader who is acquainted with the two theories of light, will perceive that though we have adopted the doctrine of the ether, the greater part of the arguments adduced would be equally forcible, if expressed in the language of the theory of emission. [16] Or rather through the _focal centre_ of the eye, which is always near the centre of the pupil. [17] Laplace, Expos. du Syst. du Monde, p. 441. [18] In this statement of Laplace, however, one remarkable provision for the stability of the system is not noticed. The planets Mercury and Mars, which have much the largest eccentricities among the old planets, are those of which the masses are much the smallest. The mass of Jupiter is more than two thousand times that of either of these planets. If the orbit of Jupiter were as eccentric as that of Mercury is, all the security for the stability of the system, which analysis has yet pointed out, would disappear. The earth and the smaller planets might in that case change their approximately circular orbits into very long ellipses, and thus might fall into the sun, and fly off into remote space. It is further remarkable that in the newly discovered planets, of which the orbits are still more eccentric than that of Mercury, the masses are still smaller, so that the same provision is established in this case also. It does not appear that any mathematician has even attempted to point out a necessary connexion between the mass of a planet and the eccentricity of its orbit on any hypothesis. May we not then consider this combination of small masses with large eccentricities, so important to the purposes of the world, as a mark of provident care in the Creator? [19] The _eccentricity_ of a planet’s orbit is measured by taking the proportion of the _difference_ of the greatest and least distances from the sun, to the _sum_ of the same distances. Mercury’s greatest and least distances are as two and three; his eccentricity, therefore, is one-fifth. [20] The stability of the axis of rotation about which the earth revolves, has sometimes been adduced as an instance of preservative care. The stability, however, would follow necessarily, if the earth, or its superficial parts, were originally fluid; and that they were so is an opinion widely received, both among astronomers and geologists. The original fluidity of the earth is probably a circumstance depending upon the general scheme of creation; and cannot with propriety be considered with reference to one particular result. We shall therefore omit any further consideration of this argument. [21] Airy on Encke’s Comet, p. 1, note. [22] Principia, b. iii. prop. x. [23] Paley. [24] If the Laws of Motion are stated as _three_, which we conceive to be the true view of the subject, the other two, as applied in mechanical reasonings, are the following: _Second Law._ When a force acts on a body in motion, it produces the same effect as if the same force acted on a body at rest. _Third Law._ When a force of the nature of pressure produces motion, the velocity produced is proportional to the force, other things beings equal. [25] Though Friction is not concerned in any cosmical phenomena, we have thought this the proper place to introduce the consideration of it; since the contrast between the cases in which it does act, and those in which it does not, is best illustrated by a comparison of cosmical with terrestrial motions. [26] Butler, Serm. 3. [27] Müller, Infusoria, Preface. [28] _Monas._ Müller. Cuvier. [29] _Volvox._ [30] _Vibrio._ Müller. Cuvier. [31] Dupuis. Origine des Cultes. [32] Herschel on the Study of Nat. Phil. Art. 28. [33] Amici me cunctantem atque etiam reluctantem, retraxerunt, inter quos primus fuit Nicolaus Schonbergius, Cardinalis Capuanus, in omni genere literatum celebris; proximus ille vir mei amantissimus Tidemannus Gisius, episcopus Culmensis, sacrarum ut est et omnium bonarum literarum studiosissimus.--_De Revolutionibus. Præf. ad Paulum III._ [34] Lib. i. cx. [35] Pensées, Art. viii. 1. [36] Thomson’s Hist. of Chemistry, vol. i. 321. [37] Manch. Mem. vol. v. p. 346. [38] “Since all reasoning may be resolved into syllogisms, and since in a syllogism the premises do virtually assert the conclusion, it follows at once, that no truth can be elicited by any process of reasoning.”--_Whately’s Logic_, p. 223. Mathematics is the _logic of quantity_, and to this science the observation here quoted is strictly applicable. [39] A l’intérieur le ministre Quinette fut remplacé par Laplace, géomêtre du premier rang, mais qui ne tarda pas à se montrer administrateur plus que médiocre: des son premier travail les consuls s’aperçurent qu’ils s’étaient trompés: Laplace ne saisissait aucune question sous son vrai point de vue: il cherchait des subtilités partout, n’avait que des idées problématiques, et portait enfin l’esprit des infiniment petits dans l’administration.--_Mémoires écrits à Ste Hélène_, i. 3. [40] Il semble que la nature ait tout disposé dans le ciel, pour assurer la durée du systême planétaire, par des vues semblables à celles qu’elle nous parait suivre si admirablement sur la terre, pour la conservation des individus et la perpétuité des espèces.--_Syst. du Monde_, p. 442. [41] Rapports du Physique et du Moral de l’Homme, i. 299. [42] De Augment. Sc. ii. 105. [43] Herschel on the Study of Nat. Phil. Art. 28. [44] Elem. of Phil. ii. p. 273. [45] Bacon. Essay on Atheism. TRANSCRIBER’S NOTE Obvious typographical errors and punctuation errors have been corrected after careful comparison with other occurrences within the text and consultation of external sources. Except for those changes noted below, all misspellings in the text, and inconsistent or archaic usage, have been retained. Pg 47: ‘a slendar stalk’ replaced by ‘a slender stalk’. Pg 48: ‘animal motious’ replaced by ‘animal motions’. Pg 54: ‘the raingage’ replaced by ‘the rain gauge’. Pg 67: ‘by Fourrier, and’ replaced by ‘by Fourier, and’. Pg 69: ‘would dimininish’ replaced by ‘would diminish’. Pg 72: ‘is obvitated by’ replaced by ‘is obviated by’. Pg 81: ‘than 1-100dth to’ replaced by ‘than 1-100th to’. Pg 131: ‘are nealy circular’ replaced by ‘are nearly circular’. Pg 139: ‘by one anomally’ replaced by ‘by one anomaly’. Pg 153: ‘would loose its’ replaced by ‘would lose its’. Pg 174: ‘a memoir entited’ replaced by ‘a memoir entitled’. Pg 174: ‘volocity, in’ replaced by ‘velocity, in’. Pg 178: ‘effects take take place’ replaced by ‘effects take place’. Pg 196: ‘and and Director of’ replaced by ‘and Director of’. Pg 200: ‘for for her young’ replaced by ‘for her young’. Pg 205: ‘in his puposes’ replaced by ‘in his purposes’. Pg 224: ‘thus irremoveably’ replaced by ‘thus irremovably’. Pg 228: ‘of knowlege and’ replaced by ‘of knowledge and’. Pg 259: ‘and no othewise’ replaced by ‘and not otherwise’.	112,904	common-pile/project_gutenberg_filtered	66406	project gutenberg	project_gutenberg-dolma-0012.json.gz:2533	https://www.gutenberg.org/ebooks/66406.txt.utf-8
l22W0WMKILpRe1s5	Tartuffe or the Hypocrite	Act IV Scene VI ORGON, ELMIRE ORGON (crawling out from under the table) That is, I own, a man . . . abominable! I can’t get over it; the whole thing floors me. ELMIRE What? You cannot mean it! Get back under the table; ’tis not time yet; Wait till the end, to see, and make quite certain, And don’t believe a thing on mere conjecture. ORGON Nothing more wicked e’er came out of Hell. ELMIRE Dear me! Don’t go and credit things too lightly. No, let yourself be thoroughly convinced; Don’t yield too soon, for fear you’ll be mistaken. (As Tartuffe enters, she makes her husband stand behind her.)	143	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/tartuffe/chapter/scene-vi-2/	pressbooks	pressbooks-0000.json.gz:8538	https://pressbooks.library.torontomu.ca/tartuffe/chapter/scene-vi-2/
jDKgggxVxYslebv9	A study of questioning, by Soshichi Yamada.	Clark University A DISSERTATION SUBMITTED TO THE FACULTY OF CLARK UNIVERSITY, WORCESTER, MASS., IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY, AND ACCEPTED ON THE RECOMMENDATION OF WILLIAM H. BURNHAM A DISSERTATION SUBMITTED TO THE FACULTY OF CLARK UNIVERSITY, WORCESTER, MASS., IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY, AND ACCEPTED ON THE RECOMMENDATION OF WILLIAM H. BURNHAM Since Socrates the question method has occupied a prominent place in the technique of instruction. " To question well," says De Garmo (19. p. 179), " is to teach well. In the skillful use of the question more than in anything else lies the fine art of teaching." Indeed, " the art of correct questioning has a highly significant effect upon the mental development, . . . ." (32. pp. 331-332.) To-day more than two-thirds of the school time is occupied with questions and answers; but unfortunately the general assumption that we know by intuition when and how to ask questions kept investigators from the study of the psychology of questioning until the dawn of this century when the genius of Alfred Binet inspired him to attempt the solution of the problem (6. p. 244). Naturally the majority of teachers whom we hire to put questions to our children ask questions for months and years without ever knowing the psychology of what they are doing, hence without ever taking into account what mental changes a question calls forth, what emotional states it arouses in the pupil's mind, how such resulting states influence the course of ideation and thinking, and so forth. If the teachers do not know anything about these changes, they are not qualified for teachers. Thus it is of prime importance for educators to study the influence of questioning upon answers and upon the mental development of the child. * The writer wishes to express his hearty thanks to Drs. W. H. Burnham and Theodate L. Smith of Clark University and to Messrs. Vermille and Butler, principals of the Dix St. and Edgeworth St. schools, for their advice and assistance in this investigation. GENERAL INTRODUCTION The question rightly used is a medium through which a teacher comes into the closest touch affectively with her pupil. The pupil's reaction-time and the mode of reaction to the given question will reveal his mental type and characteristics; for instance, whether he is of visual, auditory, motor, or mixed type ; whether his temperament is sanguine, phlegmatic, melancholic, etc. ; or again whether he is able to impress something upon his mind (memory) with ease or difficulty, whether he forgets quickly or slowly, whether he can retain a great mass of ideas or only scanty fragments ; etc. All these analytical observations are the indispensable task of a teacher in real dynamic education; for this knowledge alone will furnish the principles of individual psychology. Care, however, should be taken that the observations be made scientifically. The teacher, through such diagnosis, will discover technique for further questioning. The question is, thus, a tool for psychological analysis and diagnosis. Pedagogically, the purpose of questioning is manifold. 1. It is to awaken the pupils to self-activity, to stimulate them to think. It gives a teacher an opportunity for directing and training the thought processes of her pupils. 2. It is to cultivate the fine art of good expression. A habit of clear, concise and discriminating enunciation and of an agreeable intonation is one of the most attractive and highest gifts which any teacher can bestow upon a child. 3. It is a means of testing 'the depth of the pupil's mind. Through a series of skillful questions, the teacher brings to light the strength and weakness of his knowledge, so that she may find out his intellectual status. If the aim of the question is to train the processes of thought and expression, what will be the result when a teacher,, in one class period, say, of forty minutes, asks over eighty questions (65. p. n) and gets as many answers? What chance can there be for orderly association and deep accurate impression of ideas, or for a complete expression of thought? Furthermore the nervous tension of the pupils under such a pressure must be considered. A new science of school hygiene has arisen which is dealing with the problem of the physical as well as mental conditions of children in order that they may be able to do more work without injury. But the question as to whether the children may not make better progress in orderly association, originality, and preciseness of thought and expression, if given more freedom and time for thinking and expressing their thought as they have when engaged in their own activities, has not yet received due consideration. Time is A STUDY OF QUESTIONING 131 required to digest impressions and translate them into clear and definite ideas. Will not a " lack of time and leisure conduce to habits of speedy, but snapshot and superficial judgment?" (20. p. 37.) I do plead for the millions^ of the children who now live in agony the school years of their lives because of this dragon of misguided questioning now so universally rampant in our schools. " Every question," says Matthias (41. p. 79), " must strengthen the mental power of the pupil, sharpen his understanding, advance his knowledge, develop his speech-power. Hence one should not put any question, in which the pupil needs to think nothing or little," nor should questions be asked without giving sufficient time for purposive thinking and a complete expression of thought. Is it, however, possible to acquire the art of questioning by practice? It may be a possible attainment with practice of the most intelligent sort, but mere practice, blind and mechanical, however enthusiastic a practitioner may be, will never attain the desired end. Thousands and thousands of teachers practice questioning hourly and daily, year after year, and yet are no better off than when they began. The art of questioning can not be mastered without an accurate knowledge of its fundamental principles. In other words, mere practice is not sufficient to teach one the psychology of questioning. EXPERIMENTAL RESULTS The study of the psychology of questioning is very recent. Since Binet (6. pp. 244-324) attempted the solution of this problem, there has followed a series of experimental investigations among which the studies of Stern, Wreschner, Lipmann, Lobsien, and Borst are specially prominent. Two methods have chiefly been used : the picture method (Bildmethode) and the objective method (Wirklichkeitsmethode). In the first the presentation of pictures, in the second objects or events of real life, are used as material in regard to which testimony (Aussage) is obtained in two ways : by " free spontaneous report or narrative " (Bericht) (62. p. 270) and by asking questions, the so-called " interrogatory " (Verh'6) or Whipple's "deposition." Hereafter these German terms will be used. Binet first used the picture method and tried to work out the mechanism of the personal influence of questions upon children. He began by addressing the children as follows: cover if you have a good memory, a memory better than that of your comrades ; I am going to show you a pasteboard which is here hidden behind that screen; on the pasteboard certain objects will be seen. I shall show you them for twelve seconds ; twelve seconds, look at them attentively. It is a very short time, it is not a minute; a minute consists of sixty seconds; twelve seconds will pass by very quickly. It is thus necessary not to lose this precious time; make use of it in your observation of the objects very carefully, for as soon as twelve seconds elapse, I shall take the pasteboard away from you, and then I shall put a number of questions upon what you have seen. Many of the questions are upon the small details, and you are requested to answer exactly. Do you understand ? Is it clear to you ? " With this explanation, which, Binet says, has almost always had the effect to excite the curiosity and enthusiasm of the child, he showed the following six objects pasted on a card: a penny, a button, a stamp, a label, a photograph and a picture. The number of observers was twenty-five, all of the primary school, ranging in age from nine to twelve years. Here the object was to provoke, in the observers, errors of the forced memory, and to discover the amount of error through imagination. Hence instead of asking their spontaneous description of each object, he first asked simply an enumeration of the objects and then put a series of questions, forty-one in all. The results were very poor compared with those obtained by other investigators, because of the very brief time of exposure. The percentage of the right and the false answers was 58.2 and 41.8 respectively. (6. pp. 262-269.) Then the method of spontaneous narrative was tried, repeating the same test upon a different group of children without asking any questions, that is, the children simply wrote what they saw and remembered, the only recommendation being not to be contented with naming the objects, but to describe all the details. The number of the pupils tested was twelve, all of the upper class of the primary school, with the same conditions as far as possible. The results were: two pupils committed no error; two committed one error; one committed two ; four, three ; and three, four errors ; while in the experiment of the forced memory, the minimum of error was five and the maximum was thirteen. (6. pp. 262-269.) It is extremely probable that, if one forces the memory by suggestion, one may provoke a great number of errors. Thus Binet made three more tests by the use of the written questions. The same objects were shown as before. A number of children of ages nine to twelve were divided into three groups and each group received a different set of the questions. The first was intended to force memory, e. g., " How is the button fixed ? " The second was intended to produce a moderate suggestion, e. g., the form of the questions was suggestive of false affirmation, for example : " Isn't the button fastened with thread ? " The third gave a strong suggestion, e. g., " What is the color of the thread which passes through the holes of the button and fixes it to the card ? " As Binet expected, the majority of his observers accepted suggestions and answered as if the memory images had been true and spontaneous as is seen from the following table. (6. p. 313.) The surprisingly high percentage of the errors in case of the third questionnaire shows how few of the children have sufficient independence of thinking and will-power to acknowledge and refuse the false suggestions. Twelve normal school students made the same kind of errors as the children did, though not so gross. (6. pp. 325-329.) Binet concludes as follows : A full and concise report may be made and yet be false. (6. p. 285.) The experiment of the forced memory is subjected to error more than that of the spontaneous memory (6. p. 294). The method of suggestion by the written questions is powerful enough to influence not only children under twelve, but also young people of eighteen years of age (6. p. 329), and more so with the oral questioning. Hence if you desire a faithful testimony from a child, you must not ask him any question, nor command him to make an oral report, but require him to write spontaneously what he knows, since children are, even at the age of twelve, still incapable of distinguishing between fact and fiction or invention by imagination and reasoning. " How many adults are not grown up children in this respect ! " adds Seashore in his review of Binet's " La Suggestibilite." Following Binet, Stern performed several experiments on the same problem. One of them was carried out in the year 1902 with forty-seven observers of from seven to nineteen years of age of both sexes. After an introductory statement, almost the same as Binet's, Stern hands a picture, well known now as the Bauernstube (peasant room) to the observer to look at it attentively in bright day light for one minute, after which period he takes the picture away and asks the observer to describe what he has seen. If the observer begins to hesitate in his explanation, the experimenter says quietly: " Think of it; something may probably come to you yet." If the observer is again silent, the experimenter asks : " Does nothing occur to your mind any more ? " Upon the answer : " no," the experimenter goes on : " Now I shall ask you a little more, and certainly something will come to your mind. But if you do not know any answer to the given questions, just say : ' I do not know.' It will not harm you at all, even if you do not know." Stern allowed one minute for observation in order that a thorough comprehension and better recollection might be obtained. The resistance to falsification through suggestion was thus increased. Twelve suggestive questions were mixed with the indifferent questions to divert suspicion, and the suggestive questions were, like the second questionnaire of Binet, purely " questions " that suggested the answer " yes." Each question including the suggestive one was asked only once in the most indifferent tone, and answered orally. The results are shown in the following table. (58. pp. 295-321.) Ranschburg (48), with thirty feeble-minded children of ages from eleven to seventeen; Rodenwaldt (50), with fifty soldiers of from nineteen to twenty-three years of age; and Revesz (49), with twenty-six morally depraved pupils ranging in age from nine to fifteen, made experiments after the same method and with the same picture Stern used; Oppenheim (45), with thirty girls of from ten to twelve years of age, in 1904, with three pictures named Bauernstube, Feld, and Wasser, after Stern's method, and Breukink (n), with 108 adult observers repeating the experiment of Oppenheim, — obtained similar results. In the experiments of Oppenheim questions and answers were given orally, while with Breukink they were in written form. The former experimenter, from the second test on, encouraged her observers to do better work, telling them that many false answers had been given. This, undoubtedly, warned the observers against the influence of the questions, especially against the suggestive ones, so that a better result was obtained in the later than in the earlier experiments. The educability of children in the giving of testimony is clearly observed in both cases. Wreschner (70), dissatisfied with the method of Stern in regard to the Bericht, used his own method, the socalled examination-method (Priifungs-methode). According to his explanation, its chief characteristic is that exactly specialised themes for testimony are given to the observers ; it has the advantage of making conditions similar for all observers, and obtains an equal number of statements (Angaben) from all observers, so that the number of the statements, omissions and errors can be exactly calculable, etc. He notes that this method is closely connected with the Verhor, but he seems rather to ignore or at least to disregard its suggestive influence, as well as that of the usual interrogatory method. He used a picture called " Grossvater" with nine observers. A spontaneous report was given immediately after an observation of one minute ; the second was given after seven days ; and the so-called examinationmethod was used after seven days for four observers and also after seventeen days for the other five observers (70. p. 174). The results by this method also were similar (70. pp. 174-5). Thus it is seen that the examination method like the Verhor raises many statements from latency into actuality, but, at the same time, it produces many errors, undoubtedly due to suggestive influence caused by narrowing the conscious field. Borst (9 and 10) who followed partly Wreschner's method so that there were supposedly no suggestive questions in her experiments, though there were in reality such; Cohn and Gent (17), with and without distraction of attention during the observation of the pictures; and Dieffenbach (16) with ninety-eight observers of ages from seven to twenty, obtained results similar to those already given. We now turn from the experimental results by the picture method to those of the objective method (Wirklichkeitsmethode) and cite a few of the results. In the winter of 1903 and 1904 an experiment was made by Stern (61) on the students in his psychological seminary at the University. The procedure was as follows: A gentleman steps into the seminary, wishes to talk with the lecturer (Stern), hands the latter, with a few words, a package of manuscript, asks the latter's permission to make use of the library in the seminary-room, takes up a book, goes out after five minutes taking the book with him and is asked by the lecturer (Stern) to wait outside for the latter until the close of the seminary." The number of the observers were fifteen, six women teachers and nine students. After eight days the Bericht and Verhbr took place in writing. The result (61. pp. 17-22) was: With the Bericht the true statements amounted to 75% and the false statements to 25% ; with the Verhor 50.5% and 49-5% respectively. So, too, in the summer of 1904, Lisst (36) with twenty-two students, and Rohde (51) in 1907 with neuropathological but mentally sound patients, arrived at conclusions similar to those of Stern. Suggestibility has hitherto almost always been investigated by introducing suggestive questions among the normal questions and by a comparison between results obtained through the normal and suggestive questions. This method is not entirely trustworthy, since the suggestive questions may refer to different objects, and the different objects are not retained in memory with equal clearness. (35. pp. 418 ff.) This criticism may be avoided, if one investigates the memory for one and the same object by differently formulated questions. But naturally these different questions can not be addressed to one and the same person, hence one must put them to different persons as follows : The questions about an object (i) : to the person (A) in the form (a), namely without suggestion, to the person (B) in the form (b) or with simple suggestion, and to the (C) in the form (c) of strong suggestion. This way Binet (6. pp. 296 ff ) proceeded. But it may be objected that different persons are asked different questions. This objection can, however, be avoided, if one asks further questions about the object (II) : to the person (A) in the form (b), to (B) in the form of (c) and to (C) in the form of (a) ; and further about the object (III) : to (A) in the form of (c), to (B) in (a) and to (C) in the form (b). With this in view, Lipmann and Wendriner (35. pp. 418 ff), in the year 1904, made an experiment on twelve children of ages from four to six, using the picture called the ' Bauernstube! The questions were of three kinds, namely, group (a) was without suggestion, group (b) of an expectant nature, and group (c) contained strong suggestion and was composed of hypothetical and incomplete disjunctive questions. Each child was asked three questions of each group. The results were with group (a), the right statements amounted to 94% and the false to 6% ; with group (b) 75% and 25% respectively and with the group (c) they were 44% and 56% respectively. Because of the testimony by too small children, we can not draw any ultimate inference from such results, but still we can see a general relation among these different questions. Lipmann (33) later made an extensive experiment which gave the writer much valuable material which will be referred to later. There are two more important investigations on questioning, one by Franken (22) in 1911 and the other by Bader in 1912. Franken considered the report not only as a product of the intellect, but also of will. With this in view, he tried to test the educability of the power to report in children, that is, whether children can be taught to be more careful in stating that they do or do not know this or that thing. His subjects were 150 pupils from eleven to thirteen years. He arranged 200 questions relating to data in history, geography, etc. into two series: one as decisive and the other as determining questions. The first 100 questions begin with the words: " Do you know " so as to be answered merely by " yes " or " no ; " for example, " Do you know on what river Lyons is situated ? " The second hundred questions are so formed that a specific answer is to be given directly, for instance, " On what river is Lyons situated ? " Among other results he found that by this means the pupils can be made more cautious in their answering, though the false answers can not be fully eliminated. Some of the other results will be referred to later on. 2. What idea stands in a customary relation with the number given as a stimulus word ? Stimulus word : " Seven " — answer : " Week." And so on. His results are very interesting and agree with the writer's view formulated before reading his article. practice, warning, or correlation. It should, however, be noted that the results above enumerated are merely the average of greatly diversified individual reports, and hence show neither any standard nor any rule for individual ability. As a result of their experiments, Binet, Stern and others concluded that a spontaneous report should be asked first and then an interrogatory be given as a supplement to the former, since if questions are asked without a Bericht, there is great danger of falsification of memory induced by the questions which may not be eliminated later on by any means. This is certainly true, but none of these authors have shown how far this is true. i. They demanded the Bericht first and then the Verhor, and failed to find out what influence the Bericht has on what has been given in the Verhor, that is, what would be the result, if the Verhor were given first and the Bericht followed. 2. Their questions were on points not reported in the Bericht, that is, the questions were not on every point concerning the facts under consideration but only on the omitted ones. Although Miss Borst did this, she as well as others ignored or rather failed to find what influence the succeeding Verhor had upon what had been reported in the Bericht. These two points are very important for the formulation of any rule in regard to the order or place of the Bericht and the Verhor in the report as a whole. With these points in view, experiments were undertaken to determine whether or not the results obtained by the other investigators are applicable in any way to the subject matter in our school curricula. 3. What is the relation between questions suggesting the right answer and questions suggesting the wrong answer? Here by suggestive questions we mean the so-called expectant as well as the ' yes or no ' questions. METHOD OF EXPERIMENT As our interest is in practical application, we selected our materials from Frye's Grammar School Geography and Adam's Commercial Geography ; the section on the Surface of South America and the section on the Guianas. (See appendix.) The experiments were carried out at two different times, one, at Dix Street School, in February and the other at Edgeworth Street School, in April, 1913, at Worcester, Mass. Both were partly conducted by the teachers of each class and partly by the writer personally, but always under the writer's guidance. In the first experiment the number of pupils was ninety, twenty-one from grade 7-1, twenty-seven from 7-2, twenty-six from 8-1, and sixteen from 8-2; but three of grade 7-2 and one of grade 7-1 are not included in our numerical calculation, as they did not finish their work in time. In the second experiment, forty-four pupils took part: eleven from grade 7-1, ten from grade 7-2, thirteen from grade 8-1 and ten from grade 8-2. Both of 8-2 were given the section on the Guianas as subject-matter which they reviewed silently for ten minutes before the Bericht and the Verhbr were required ; the rest of the pupils were given the section on the Surface of South America which they reviewed about six to seven minutes before the Verhbr or the Bericht was required. The time for the Bericht was about fifteen minutes and that for the Verhbr about twenty minutes. The pupils of both grade 7-1, and those of grades 7-2, 8-1, and 8-2 in the second experiment answered the Verhbr first and then gave the Bericht; and those of 7-2, 8-1 and 8-2 of the first experiment gave the Bericht first and then replied to the Verhbr. In the experiment when the Verhbr was given first, care was taken to erase the questions entirely from the blackboard before the Bericht was demanded, and also to make clear to the pupils that they should report again all that they knew on the subject in the Verhbr. The suggestive questions were formulated according to Lipmann's advice, that is, different forms of the suggestive questions were asked on the same subject-matter but to the different observers so that the suggestiveness of the questions might be compared. The pupils of grade 8-1 in the second experiment were not asked suggestive questions but the normal questions. During the experiment every precaution was taken not to give any suggestion whatever. demanded two data was counted as half a unit. 3. Answers to some of the questions (such as n, 12, and 14. See Appendix.) were not demanded in full. If a pupil gave two names of the products or goods for exportation or importation, he was credited one point, if he gave only one name, he was credited half a point. a. If a pupil reported : " The vast forests in the Amazon river basin are called Selvas," he was awarded two points, since this report contained two facts corresponding to two questions in the Verhdr; but if a pupil reported : " The vast forests in South America are called Selvas," he received only one point, as it gave only one fact. b. If a pupil reported : " The Andes highland lies along the west coast of South America, he was credited with two points, though this answer, strictly speaking, is not complete, since it is important to know that the Andes is the primary or greatest highland. c. If a pupil stated : " There are three plains called pampas, llanos, and selvas," he was credited one point, since some pupils thought that selvas meant a grassy plain in the south, while pampas meant a forest in the Amazon basin, etc. As a whole these were the only difficulties, and so few in number that any alteration in the crediting caused but a small fraction of change in the percentage. The question naturally arises : Does not the pupil make any statements in the Bericht in addition to those contained in the sections employed for the experiment ? To my surprise only five such statements intruded into the spontaneous reports: two pupils added " Plata river ; " another two " Orinoco river " and one " Guiana highland." These five points were credited, if the statement was clear. RESULTS Our results are as a whole very similar to those obtained by the other investigators as the following tables show. That is, our results show that the Verhdr gives far greater range of report in quantity, but much worse in quality than the Bericht. It is, however, to be noted here that while this is always true of the general average, it is by no means true of each individual. Five pupils made no errors in either the Verhdr or the Bericht. Tabulating the reports of the normal questions, we have fourteen out of 130 pupils who obtained the full credit for every one of the questions. In both spontaneous reports it is rather surprising to find that ninety-five out of 130 pupils committed no errors. I. Relation between the Bericht given first and the succeeding Verhbr. A certain number of the statements given in the Bericht were altered rightly or wrongly in the succeeding Verhbr as follows: Total . . In other words, thirty-nine correct statements out of the total 402.5 given by the sixty-six pupils in their Bericht were changed wrongly in the succeeding Verhbr by twenty-four pupils. For instance, in the Bericht, two pupils reported that the Andes highland lies along the western coast of South America, but in the Verhor they answered question 7, " the Brazilian highland." Another boy and girl reported that the Amazon river flows from the Andes highland and is the largest in the world, but they answered question 15, '* from the Brazilian highland." Some pupils reported in the Bericht, " the coast of South America is not as irregular as that of North America," but they answered question 3, b, with " yes, it is as irregular as that of North America." Two girls of grade 8-2 reported that the British and Dutch planters plant coffee and cocoa in place of the sugar-cane because the price of cane-sugar has declined, but they failed to answer question 5. On the other hand, six of the total 18.5 false statements in the Bericht remained false in the Verhor; the other six of the 18.5 false statements were corrected by the questions in the Verhor; while the other two were changed to the answers : " I don't know." Thus we may justly infer that the Verhor is more likely to make the right statements of the Bericht false than to change the wrong statements to right ones. The question naturally arises here: Why should questions as a whole have such an influence even upon what was given correctly in the Bericht? The reason which we shall discuss later on may be stated here briefly as follows : The pupils are now questioned after they have given what they thought true and correct, and this inquiry draws their attention to the idea so intensely that it rouses in their minds an element of doubt and causes them to become more suggestible. II. Relation between the Verhor given -first and the Bericht following. To determine this has never been undertaken by any of the investigators. It becomes thus one of the chief points of interest in our experiments. We said as a result of the experiments hitherto performed that the questions influence our memory so much that any distortion right or wrong may not be eiadicated later. From this it might be supposed that after a given lesson had been studied for a certain period of time, if questions be asked that cover each fact, one should be able to give a far better report in the succeeding Bericht on the same subject-matter than if asked to give a Bericht immediately after the study and before the detailed questions. Indeed the questions preceding the Bericht analyze the whole subject matter clearly into points and connect them with the questions so that they serve as a sort of resume and may thus facilitate the succeeding Bericht. And to a certain extent this hypothesis is true, but not so completely as might naturally be expected. If we compare the results from grades 7-1 and 7-2 in the first experiment, which are most justly comparable, because the pupils were taught by the same teacher under the same conditions, we see only a slight difference ; again the results from grade 8-1 in the second experiment, where no suggestive questions were used, and 8-1 in the first experiment, and from 8-2 in both experiments show merely slight betterment, although 7-1 and 7-2 of the second experiment show rather better work than any other. Furthermore, the Bericht that followed the Verhor revealed a most interesting phenomenon: nine correct statements out of the total 478 given in the Bericht by the pupils of grades 7-1, 7-2, 8-1 and 8-2, were not answered by them, when questioned in the preceding Verhor; forty-five correct statements of the 478 were the correction of what was stated falsely in the previous Verhor; sixteen false statements of the 478 were the remainders of what was already given falsely in the Verhor; and three false statements of the 478 were the falsification of what was given rightly in the Verhor. For example : one girl answered, " no, it does not," to question 16, b, but in the succeeding Bericht she said that the surface of South America resembles that of North America. One boy answered the question 22 (what are the vast forests in Brazil called? Answer, selvas), with "They are called pampas," but in the following Bericht said : " The vast forests of Brazil in the Amazon basin are called Selvas." These facts show clearly: that the influence of the Verhor upon the succeeding Bericht is rather slight, that the mental activity of the children in the Bericht differs from that in the Verhor where they are made abnormal and passive, being compelled by the external influence of the questions, while in the Bericht they are self-dependent, being free from any external compulsion ; or in other words, we may say that the mental attitude of the pupils towards the Verhor is different from that towards the Bericht. In regard to the so-called sequence or place of the Bericht and the Verhor, we are made a little skeptical about the statement that the Verhor should be subordinate to the Bericht as a sort of supplement. It is certainly better to ask the Bericht first and then give the Verhor on those points not stated in the Bericht so that any distortion of what was given in the Bericht may be avoided in the Verhor; but if our inference is correct, that is, if mental activity in the Bericht has a peculiar tendency to correct what was given falsely in the Verhor, then is it not also useful to demand a second Bericht after the Verhor? In school practice, and even in the court where we do not know anything about the event, we may ask questions first and then demand the Bericht just as well as to give the Bericht first and then the Verhor, so long as there is no hypothetical, incomplete disjunctive and sequential question in the series of the given questions. The writer does not disregard the suggestive influence of questions by any means, but wishes to emphasize the significance of the mental attitude in the Bericht. The psychic after-effects of the impressions received in the observation are of various degrees of intensity, vividness and clearness. The things observed with interest and attention are apt to be most firmly fixed and thus be kept most clear, while those perceived inattentively or unconsciously leave behind only insignificant traces or none at all. (58. p. 329.) Intense, vivid and clear images or ideas lie always nearest to the threshold of consciousness waiting, so to speak, for the imperative impulse for self-expression to shake off the yoke of inhibition. Such ideas take precedence in the Bericht. In addition to these, the observers with more or less effort raise above the threshold many ideas of somewhat vague potentiality which have lost their clearness and obtrusive character in comparison with those of the first group, although still possessing sufficient persistence to come within the sphere of voluntary recollection (58). Hence the Bericht is not passive, but active in the highest degree. It is a more or less powerful and independent conscious selection of the most vivid and clear ideas in memory to which is attached the feeling of the greatest certainty and, above all, of spontaneity. Because of this will-activity with a feeling of spontaneity, any vague ambiguous and uncertain ideas are rejected. Consequently the Bericht is good in quality though unfortunately its range is small. This psychic activity in the Bericht can be further verified by the results of experimentation. Rodenwaldt gave his observers an opportunity to look at the picture again in order that their self-correction might be made in both the Bericht and the Verhor. This showed that the correction of the Bericht was so small, as to amount only to one-seventh of the total false statements in the Bericht, while two-fifths of the false statements in the Verhor were corrected. This clearly shows that the confidence in the Bericht was so great that there was no thought of correction. (58. pp. 325-326.) It is quite different with the Verhor. The activity here is passive or reactive in a sense of being constrained from without, — though it is quite necessary and helpful for recall of what the spontaneous report fails to give. The effect of a question or theme for recollection is twofold (24) : it offers a key to open the store-house of the latent ideas which otherwise may remain continuously submerged, or it may draw the observer's attention to a gap in his knowledge so that he attempts to fill it with an answer of some sort. And this is done quite often from an irresistible impulse, since every question, even the most indifferent, the most cautious and the most unsuggestive, as appears in the experiments, is more than a mere question. It is a command for a recollection and the production of a certain answer (58. p. 330). This double effect of a question in suggesting to an observer a true or false answer is clearly seen in all the results mentioned. So great is the wish to give a certain answer, that the critical power is weakened. Hence the increase in quantity and the deterioration in quality in the report. The psychological conditions of the false answers are very different and depend on many factors which will be discussed later. Obviously there are disadvantages in both the Bericht and the Verhor. Testing the mental state of a child by either would be a defective method. As Stern (58) and Wreschner (70) state, the spontaneous report allows very great latitude in individual voluntary activity and this causes some observers to notice very few, and others very many details, thus making the comparison of the different observers a particularly difficult problem. Moreover, we can not state justly whether a failure in regard to a certain fact or point in the Bericht is due to a lack of retention or failure in the power of immediate recall. Hence neither the Bericht nor the Verhor taken separately give the real mental status of the observer. They must go hand in hand. We must remember what we have already shown that to neglect to train the power in the Bericht, and to rely on the Verhor alone is to make children passive and halting in their self-expression and independent mental activity. The following examples taken from the answers given by our observers show the great individual variations among pupils. Some can do good work respectively in both the Bericht and the Verhbr, while most of the observers fail in the Bericht, not only when given before but also after the Verhbr, in spite of the fact that they can do fairly good work in the Verhbr. One boy who could answer in the following Verhbr twenty-three questions correctly out of twenty-four, gave his Bericht: following excellent Bericht. "The three Guianas (British, Dutch and French) are interested in the production of cane-sugar and its by-products, molasses and rum. Owing to the decline in the price of sugar-cane, the British planters have replaced it by coffee and cocoa. The British supply one half of the fuel and coal used, and the United States one fourth. A large amount of rubber is produced in the Guianas, and an important amount of gold. Most of the cultivation is done on a narrow strip of land near the coast, where most of the people live. Paramimbo is the important trade center at Dutch Guiana, and trade of French Guiana." Verhbr, viz. " South America resembles North America in shape, etc. The northern part is wide but tapers towards the south. There are great mountains on the west and smaller highland on the east. The Andes highland on the west is long and narrow; and higher than the rocky mountains of North America. The highland of Brazil on the eastern part is wide but not nearly as high as the Andes. There is a great plain between these two highlands called the central part. It is divided into three sections. The central part along the Amazon river is called selvas meaning forests. The northern part is called llanos meaning grassy plains, the southern part called pampas also means grassy plains." QUESTION There are various forms of suggestive questions, though not always perceived as such. Stern says that hardly any ideal question is an entirely unsuggestive question. (58. p. 339.) Hence it is impossible to avoid suggestion in the T/erhor. (64.) Against the above statement of Stern, Miss Borst (9. p. 78) argues as follows : " I can not agree with him. According to my opinion, there is suggestion only when we put to an observer a question which refers itself to an object which was not present in the picture or the like employed for the experiment, and by means of which a false idea will be smuggled into the observer's mind. All other questions, however, which refer themselves to a really presented thing, build only a support for recollection, and that is exactly what is aimed at by the Verhor" (9. p. 78.) Thus she means by a suggestive question one which gives a false suggestion, but, as we shall see later, we know that a question may suggest a right answer. Moreover, what does her phrase " a support for recollection " mean? Does it not mean a narrowing or limitation of our conscious activity, leading or inducing the observer to focus his attention on a certain idea or ideas? When the mind of the observer becomes more and more a blank as the result of voluntary inhibition of ideas or associations, he is more apt to yield to suggestion. This is because the power of suggestion often consists in the fact that the mind is centered on only one or two ideas ; all distractions are carefully excluded, and much greater power is therefore manifested along the restricted line than when the mind is attending to many stimuli simultaneously or in rapid succession. Inhibition of all ideas but one greatly intensifies the one. Along this special train of thought we are prone to be swept by suggestion. Does there not then in the function of support for recollection lie a suggestive influence which she seems to ignore ? It is a matter of course that every question is not suggestion, but there is suggestion in every question. She further says : " One observer, for instance, forgot to name an apron in his enumeration of the articles of clothing, and I put to him the question, whether the child had on an apron or not? Here we have certainly nothing to do with a suggestive question, for there is no ground at all which to the observer would suggest a positive answer rather than a negative one." (9. p. 78.) But if the observer failed to notice the apron, as Breukink (n) found, he might get a suggestion from such a question. We can not, however, agree with Stern (64) when he says that it is absurd to ask, for instance, about the color of a hat, when the observer has not named it in his enumeration of articles of clothing. He maintains that by this question suggestion will be made ; for when the observer omits the naming of the hat, it shows that he had no recollection of its existence. Miss Borst remarks, I do not understand this objection : " Tht investigations of memory teach us (and Stern himself ha* emphasized this) that it can not be said that a recollection has vanished from the memory. Even when it does not occur spontaneously ; elements of recollection can remain latent in memory. The purpose of the Verhbr is precisely to revive these elements of recollection from their latency." (9. p. 79.) All the other investigations as well as our own have shown that the observers have failed to mention certain things, yet answer questions in regard to them with certainty. It is a question whether or not such an answer is suggested or a real memory. Probably both factors co-operate in such a case. A question as a whole has not a suggestive influence when the memory is clear, vivid and strong, and accompanied by a feeling of certainty. On the contrary, every question is apt to be suggestive when the memory is vague, obscure and uncertain. Attention was drawn to this problem first by Binet (6. pp. 297 ff), but the more elaborate gradation was left to Stern (58. pp. 338-345) and later taken up by Lipmann. Stern grades the suggestiveness of the questions beginning with the least suggestive as follows: (i) The determining question (Bestimmungsfrage), or the question introduced with interrogative-pronoun or adverb: which, who, where, why, etc ; (2) the complete disjunctive question or the " yes or no " question; (3) the incomplete disjunctive question or the " either-or " question; (4) the expectant (leading) question or the " yes " question or " no " question; (5) the hypothetical and (6) the sequential question (Folgefrage). Lipmann (33. pp. 58-60) used practically the same distinctions. Each of these forms of the questions has its own peculiar psychological significance or function. We shall follow the analysis of Stern. The determining question offers a wide field of ideas within which an observer can exercise his own power of free choice. Hence he can be self-assertive in his answer; for instance: what is A? Describe B? has no limitation for the field of ideation about A or B. Such a question simply appeals to the most indifferent and harmless question. The complete disjunctive question, or the "yes or no" question, requires the observer to decide between the two ideas offered by the question, or between ' yes ' and ' no/ one of which is always false. For example: Was that A or not? Here the idea A is presented to be selected or negated from the vast field of other ideas, and apparently there is no limitation for the answer. But when we introspect, we perceive the idea A clearly and distinctly with vague ideas coming and going in our conscious field, as its back-ground. Consequently the idea A has an affirmative, while the rest have a negative tone. The only chance is either to affirm or negate A. This limitation in the selection of the answer renders the suggestion more influential than the preceding question. According to both Stern and Lipmann, the tendency to answer " yes " is stronger than that to answer " no," but Borst takes an opposite view. This may be due either to the special influence of her oral questioning or to difference of suggestibility of the observers, as it is found by Goddard (23. p. 4) that a certain type of child will always answer the last of two alternatives. Our experiment also shows that a certain child answers always with " yes," and another always with " no," no matter whether the question is a " yes or no " question or expectant question, but the tendency to answer " yes " is far stronger. Lipmann says (33. p. 58) that the complete disjunctive question, for instance : It is A or B ? is less suggestive than the " yes or no " question, e. g., Is it A ? This is to be contrary to the result of writer's own introspection. The form, " Is it A or B ? " suggests dual or rival determination, presupposing belief in a sphere of existence in which either supposition or both may have confirmation according to the meaning. Though there is surely suspense as to which of the possible assertions is to be accepted, but the certainty of the issue to be A or B or both is expressed, and consequently the field of ideation is exhausted by A and B (15. p. 347). On the other hand, " yes or no " question, e. g., " Is it A or not? ' or " Is it A? " are of an indefinite alternative over against the definite alternation of the complete disjunctive question, because " it may be A," or it may be something else. Of course it may happen to be exclusive, if " it is A," but never exhaustive in its suggestive influence like the complete disjunctive question proper. " Is it A ? " is called a true " yes or no " question, when the answer A is true ; and it is called a false " yes or no " question, if the answer A is false. The following table shows the difference of suggestiveness of each form of question for 117 pupils in our experiments. 4. 1 7 Hence it appears that the true " yes or no " question produces far more right answers in every case than the false one, while the latter without exception produces more false answers than the former. Moreover seven of 117 pupils answered with " yes, so and so," and three with " no, so and so " to every " yes or no " question whether or not its content was true or false. From these results it appears that our school children are not only suggestible but also are mechanized to react to the form of the question instead of to its content. The expectant question (leading question), is more suggestive than the former according to Stern and Lipmann, since the form of the question in itself represents the questioner's expectation and leads the observer to accept it unconsciously. Take, for example, a question : " Was it not A ? " and analyze it into the two parts : "It was A" and "was it not ?" The first part affirms that it was A, while the second shows a clearly expressed expectation. The mind has a tendency to accept as true anything that enters it. A belief is urged from the start by the words " was not." The suggested idea must, thus, dominate, even when the observer has a clear knowledge of it, as the possibility of doubt is covered by the probability of the expectation. The first given interpretation persists and is taken as true even without being consciously regarded as true or false. This is frequently true when his knowledge is vague, and his belief in the questioner is strong. The expectant question is, according to Lipmann and also in the opinion of the writer, weaker than the incomplete disjunctive question, for the former causes the observer to appeal to his memory, feeling of course the influence of the insinuation which results from the question, and in some cases the word ' not ' serves as a warning, while it is not the same with the incomplete disjunctive question which offers two ideas, neither of which is true, presupposing that one of them is true. Lipmann differentiates the expectant question as false and true according to its meaning. For example : Is it not A ? is true if asked, when the answer A is right, and it is false, when the answer A is false. His result shows (33. pp. 69-70) : " the false answers were diminished about 24% by the right expectant questions, and the right answers were diminished about iS% by the false expectant question in relation to the total statements. The right answers were increased about 12% by the true expectant question and the false answers about 2% by the false one, in relation to the total statements. In both cases the suggestive formulation caused an increase of the uncertain answers ; with the true expectant question about 13%, and with the false about 17%'. Thus he concludes that the true expectant question has a stronger influence than the false, and that the former brings out more right and fewer false answers than the latter. (33. pp. 54, 60, 61.) Our experiments with 117 pupils confirm Lipmann's results. The expectant questions gave: r=i37, f — 27, u = i, that is, the true statements amounted to 83.7% and the false ones to 16.3%, while with the false expectant questions, r — 98, f = 55, u = 8, that is, 64% and 36% for r and f respectively. Furthermore twelve of 117 pupils in both experiments answered every expectant question, whether true or false, with " yes, it is so," and three with " no, so and so." Here again, the children are habituated to react to the form of questions, and not to their content. It is of a vital significance for a teacher to recognize this different function of the true and false questions, as each gives such a different result clearly shown by our table. The incomplete disjunctive question is stronger in its suggestive influence than the preceding ones, since here neither of the answers can be right. As, in case of the complete disjunctive question, the possibility of an answer is not only logically exhausted, but the probability of a wrong answer is very great; for to answer independently of the two alternatives offered requires a mental self-reliance, of which most of us are not capable. This type of the question too can be divided into two forms : true and false, according to its content. The hypothetical question is in its form exactly the same as that of the determining question, for instance : " what is the color of A?," and must be valuated unsuggestive from the stand-point of the form. But suppose that the observer until questioned did not know of the existence of A, what will be suggested? He will surely reason: The question asks now after the color of A, then there must have been A (58. pp. 342-343). He will thus come to silently accept the intentional suggestion of the questioner. If A is once accepted, it is easy to attach attributes to it. Even when the observer does not or can not attach a color to A, if, for instance, he answers, " I do not know its color," he is still a victim of the suggestion, for he tacitly admits the existence of A in the form of his reply. The hypothetical question also can be divided into true and false forms according to its content. The sequential question makes use of an implication: One who says A, must also say B. (58. p. 343.) For instance : If a question, " was not A there? " (when in reality it was not there) is accepted by the observer, then this acceptance means that he will admit the existence of the color, size, etc., of the A, as it is natural to infer that the A should have been colored, etc. The sequential question is used when a hypothetical or the like question is accepted. Thus we can make a graded series according to the degree of suggestiveness contained in the form and to some extent the content of the questions. However, the suggestive influence of each form of the above questions is not in its numerical percentage proportional to the scale. To answer a hypothetical and sequential question, a part or the whole of an object or a thing must be invented, and this invention needs a great mental effort, or a struggle against the present mental state. This is probably the reason why these questions result often in a small percentage of errors. Again that the effectiveness of the suggestive questions declines strongly with increasing age, while the frequency of the erroneous answers to the normal questions is fairly independent of age, shows that the nearer a question is to the normal, the less suggestive it is. It is interesting to note that the observer passes through various stages of mental resistance against the suggestive influence of questions. According to Binet's observation, the first instance which follows the reading of the question is a moment of scepticism. This is shown by a murmur, " But I don't know," or by the gestures of ennui or negation, or mimic expressions, etc. Some translate this state of scepticism by the written answer, " no," which they finally efface ; some say " no, it was not so." This state of an initial resistance persists indefinitely with some observers. (6. p. 303.) The second phase is that of half yielding to the suggestion. The observer commences to write his answer, but he is arrested by a decisive word or words. Finally, a third phase is that of the execution of the suggestion. Here the observer shows often, at the moment when he writes his answer, a flushing of the face, as if he had a sentiment of shame. On the other hand, there is sometimes a resistance which is first at a maximum and then terminates with a disbelief in suggestion. (6. The same phenomena have been observed very distinctly by the writer in his own experiments. It is rather surprising to find that thirty-two cases of 117 pupils in both experiments erased their answers to the " yes or no " questions as well as to the expectant questions and corrected rightly or wrongly in the following ratio, that is, twenty-two cases rightly, and ten wrongly. For example, some pupils answered, " Yes, it is as irregular as that of North America" to the question 3 (b) (Is the coast of South America as irregular as that of North America?), but erased this answer and wrote " No, it is not." Others wrote first, " Yes, it means level land," to the question 21 (b) (Does 'llanos' mean level land?), but corrected it to 11 no, it means highland," erasing the first answer. Besides these thirty-two cases of correction, there were four special cases where two pupils wrote " no " as an answer, but erased it, and then wrote " no " again, while the two others did the same with " yes." obtained follows. That the " yes or no " question is more suggestive than the determining question has been shown experimentally by Binet (6. p. 313), Chomjakov (14), Lipmann (33) and others. Our investigation with 13 pupils showed with the normal questions (3, 9, 16, 19, and 24 of 2nd series, appendix), true answers amounted to 71.9% ; false ones to 21.9%, and uncertain ones to 6.2%>; with the corresponding true "yes or no" questions with 42 pupils, 90.4%, 9.6% and zero % respectively ; and with the corresponding false " yes or no " questions, 54.7%', 41.5%, and 3.8% respectively. The results of Stern, Rodenwaldt, Oppenheim, and others show that the leading (expectant) is more suggestive than the determining question. But in all these cases, the leading as well as the normal questions were applied to the different objects, so that we may not be justified in depending upon their results. The results of Chomjakov and Lipmann can justly be relied upon, for they applied both kind of questions to the same objects, though as a matter of course using them on the different observers. Chomjakov (14) showed three groups of each fifty students a sheet of paper which was spotted with red and violet color. The first group was asked : " How many red and how many violet spots have you noticed ? " The second was asked : " Have you not noticed red spots between the numerous violet ones here and there, and how many were there?" The third: " Have you not noticed between the numerous red spots here and there, also violet spots, and how many ? " The results were : The first group answered on an average with eleven red and eight violet ; the second with fifteen violet and four red ; the third with four violet and fifteen red. Our results agree to some extent with Lipmann's (33. PP- 53~4» 68-9). They show clearly that the true leading questions suggest the right answers more strongly than the false leading questions do the false answers when compared with the non suggestive questions corresponding to both. We obtained in the experiments with the normal questions (8.13 and 21 of 2nd series, appendix) with 13 pupils: true answers = 71.8%, false = 20.5%, and uncertain = 7.796 ; with the corresponding true expectant questions on the 42 pupils, r = 94%, f = 6%, and zero for u; with the corresponding false expectant questions, 66.7%, 20% and 13.3% respectively. From all these experimental results, it is seen that the expectation aroused by means of the phrase, " Was it not," or words like " numerous," " truly," " perhaps," " honestly," etc., or some special instruction or silent manipulation — as in the experiments of Lobsien (38), Kosog (29, 30), Seashore (56. pp. 30-31), Scott (55), Plecher (47), and others,— produces a high percentage of suggestibility. And that the false leading questions do not act more suggestively than the false " yes-or-no " questions, provided that the former are differentiated from the latter only by the word " not," is determined by both Lipmann (33. p. 70) and Rodenwaldt (50). In our own experiments the false " yes-or-no " questions brought out more false answers than the false leading ones. This is perhaps due to the fact, as Rodenwaldt rightly states, that " the intelligent observers easily discover that they will be led into a trap by the word ' not ' " and become cautious, while they more easily fall into a trap with the false " yes-or-no " questions where the word ' not ' is omitted. For the suggestive influence of the false hypothetical and the incomplete disjunctive questions the readers are referred to Lipmann's exact work (33. pp. 75 ff), Binet (6), Lobsien (38), and others. content ; that a determining question is the least suggestive ; that the true leading as well as the true " yes-or-no " questions are more suggestive than the false ones, the former evoking more right answers and the latter more false ones without exception. It makes a great difference whether a question is presented to a pupil by his fellow-student or by a teacher ; to a witness, by a disinterested person or by a judge. " The presence of persons," says McDougall (40. pp. 98 ff), "whom we regard as our inferiors in the particular situation of the moment evokes the impulse of self-assertion ; towards such persons we are but little or not at all suggestible. But, in the presence of persons who make upon us an impression of power or of superiority of any kind, the impulse of submission is brought into play, and we are thrown into a submissive, receptive attitude towards them." " The personality or impressive character," says Keatinge (26. ch. 5), " can set up in another a state of emotion sufficient to produce an unstable and easily dissociated condition of mind, and thus to inhibit the rise of the development of contrariant systems." Such an authoritative influence is apt to modify the nature of an answer. Thus under the influence of an authority or of masterfulness in the questioner, an observer may come to such a logical conclusion as follows : " Why, what else can I think of ? The desired answer must surely be right! The questioner should know it; why, I thought it was this, but he asks about that, am I then mistaken, or is he? No, he should not be so, then I must be." Consequently, if a question is a " yes-question " or a " no-question," he will answer " yes " or " no " without further reflection. If a question is a " yes or no " question, he will react to it with " yes," irrespective of the content of the question, even where according to his knowledge, the answer should be negative. Some pupils, as we have seen, are mechanized to answer " no " to every " yes or no " question, whether its content is true or false, while the majority are habituated to " yes." If, however, a question is an incomplete disjunctive or a false hypothetical question, one will decide in favor of the most probable answer (33. p. 214). Counsel (taking up the two lower bones of the leg attached and approaching the witness.) " Will you please take these, doctor, and tell the jury whether in life they constituted the bones of a woman's leg or a man's leg? " Here it is clear that this doctor's answer was modified wrongly by the counsel's facial expression, which was interpreted by him as a sign that his answer was wrong. So, too, children's answers in the school-room are often modified by their teacher's facial expression. We cite a few examples from the returns to a questionnaire used not for the purpose of studying questioning but for the study of imitation and suggestion. " The teacher in history may ask you a question and generally one that has to be explained. It might take three or four minutes to answer. All the time her face seems to be a perfect blank. She does not look at the person reciting or answering but directs her gaze in another direction. Sometimes I stop and wonder if I am saying the correct thing and then finish the recitation or answer in its midst. If she would only attend to our answers and recitation, we would have much more confidence in our work and do it better." The slightest inclination of the head, the dropping of the eyelids, or a certain expression of the face are apt to be read by the shrewd pupil as a sign of the truth or error of his answer, so that he may continue or stop his recitation. (4. pp. 76-77.) It is better not to give any sign whatever while a pupil is answering, except for an encouragement when a pupil is timid or hesitates to express himself. To help a child by such signs makes him passive, leads him to depend upon the teacher instead of relying upon his own knowledge. It fosters guessing or leads a bright but unprepared pupil to steer through a recitation guided by the through the following examples : " I know," says a Normal School girl, " some teachers who ask a question in such a manner and tone that it is easy to know whether the correct answer is ' yes ' or ' no.' Then I have known of another case where by the teacher's facial expressions, gestures, etc., you could tell, if you had only recited the first part of the answer, that it was wrong or right." (Twenty-one cases.) Another girl says : " I have always been greatly aided in my recitations by carefully watching a teacher's face. In most instances I can tell whether or not I am ' on the right track.' There is something about their facial expression (very slight indeed) that helps me to ' feel my way,' so to speak. This means, of course, was used more during my grammar and high school years." As the facial expression, so the tone of a teacher's voice affects the answers of children. In our school rooms we frequently notice that the pupils often decline or fail to answer the questions asked, and generally it is inferred that they do not know. But such an interpretation is very often incorrect. For instance, a girl of twelve says : " I knew very well the answer, but the teacher's tone of questioning suggested to me that she does not care much about the answer. So I felt that my answer was not important and consequently I did not answer." (9 cases.) Still another girl says : " If her tone indicates that she is cross, I don't feel free to talk during her lesson or to answer her questions; it also discourages me and makes me not to enjoy the subject. As a result I often remain silent waiting impatiently for the period to end." " Our teacher's voice was so sharp and cross that whenever she called my name, I became very nervous and could not answer her questions even when I knew them well." (Thirty-one cases.) minds and hearts. Again when a questioner puts a special emphasis on a certain word or uses either rising or falling inflection in her questioning, the corresponding answer may be of little value. An observer takes a suggestion from the word that seemed most emphasized and reacts to it with the very word. Such a reaction is most likely to take place when a " yes or no " question or a " leading question " is asked with a certain inflection of tone. Closely related to the above factors is a questioner's expectant attitude towards an observer. If, however, they expect us to do our best, that very cooperative expectation inspires and infires us to do it, and we succeed." (31. pp. 53-54.) So, too, the expectation of a teacher causes the weak-minded, the discouraged, the nervous, and the like to form the same opinion of themselves. Thought tends to realize itself in actuality ; they become what they think. This is why some children are made nervous or confused and often fail to answer a question or to recite, when asked with words like these : " John, can you answer, I don't think you can, but try it ; Mary, I doubt if you can. . . . and so on/' A seventeen-year-old girl reports : " In another class I am almost afraid to say anything, because the teacher impresses me as having the attitude that she is sure I am going to make a mistake, and that she is very much surprised if my statement is correct. In one or two instances, I have known this teacher to stop a pupil in the midst of a statement, saying that it was wrong; while if she had let the pupil finish it would have been correct." (Five cases.) Another factor that has an important effect on the nature and the possibility of an answer is a sympathetic or nonsympathetic attitude. Sympathy is an indispensable quality for normal suggestibility. As in water, face answereth face, so in man, the heart to heart. The following examples are illustrative: " The plaintiff, a laboring man, had been thrown to the street pavement from the platform of a car . . ., and had dislocated his shoulder. He had testified . . . that ... he had not been able to follow his usual employment for the reason that he could not raise his arm above a point parallel with his shoulder. Upon crossexamination the attorney for the railroad asked the witness a few sympathetic questions about his sufferings, and upon getting on a friendly basis with him asked him 'to be good enough to show the jury the extreme limit to which he could raise his arm since the accident.' The plaintiff slowly and with considerable difficulty raised his arm to the parallel of his shoulder. ' Now, using the same arm, show the jury how high you could get it up before the accident,' quietly continued the attorney; whereupon the witness extended his arm to its full height above his head, amid peals of laughter from the court and jury." (68. pp. 47-48.) Such a drama is played by our school children more or less in response to a teacher's sympathy towards them. The effect of any unsympathetic attitude appears in various ways as follows : A girl says: "One teacher I had was never sympathetic toward me. She was always finding fault with my recitation and answer unless I recited the lesson in her words. Thus I failed to answer even the easiest question." (Eight cases.) Another girl says: "A fault-finding attitude of our teacher amuses me so much that I look indifferent and hit less in my answering in order to excite her." (Three cases.) All experimental results show that a suggestive question succeeds in one case, but fails in another. It never succeeds uniformly. Again some persons are so suggestible that they are influenced, even by nonsuggestive questions (57. p. 132) ; others can resist even the strongest suggestion involved in a question. The suggestiveness of a question thus depends primarily upon the suggestibility of the person questioned, and this is not constant, being dependent on many internal as well as external factors. First of all, the mental content of the person questioned is responsible for the suggestiveness of a question. The potential starting point of an individual reaction is an object or a fact, ideal or perceptual; and every object, or idea, possesses for an individual mind a stimulative or a suggestive influence. The individual conscious state at the moment interprets a stimulus, accepting or rejecting it. Hence, if the content of the mind in question is poor, ill organized and unsystematized, the mind is apt to be a victim of an external as well as an internal stimulus. This is the reason why many experimenters hold that the less intelligent an observer is, the more suggestible he is, and that children are, in general, more suggestible than adults. Even with people of higher intelligence, deficiency of knowledge relating to the given topic heightens the suggestibility of the person questioned. In the case of a child, a similar suggestibility occurs whenever there is little or no direct conflict with his experience. A child believes in any commanding idea, in a pleasurable or wished-for thing as well as a dreadful or not-wished-for thing. This subjectively conditioned belief, auto-suggestion or credulity supposes always a grade of dissociation, from which no child can be absolutely free. If this dissociation increases, the object of each agreeable idea can be finally believed and appears as real. (37. p. 246.) Belief is an original and a natural process in the mind of a child. He does not doubt any thing that he learns until he has accummulated a considerable amount of knowledge, and attained a relatively high stage in the development of intelligence. Moreover " to doubt is usually unpleasant and may arouse complicated strain sensations to add a new element to the unpleasantness" (46. p. 34). Consequently, even when a child's knowledge is comparatively accurate, when he is under the sway of an authoritative impression or his own auto-suggestion, he may answer as suggested, thinking that perhaps that is called ' A/ which used to be called ' B/ Such a reaction may not take place so easily if a question is asked by a fellow-student or an inferior person, but it is apt to happen under the influence of authority. When a person is influenced by a suggestion he loses his critical or analytical power towards the form and content of a question and simply attends to or searches in his memory for corresponding ideas, and finally produces his answer as if it was a spontaneous report. Whenever credulity and authority go together, the result is doubtful. Lack of will, too great credulity, and too little self-criticism are great obstacles to independent, self-assertive reaction (62. p. 272). Another group of persons yield to a suggestion even against their own knowledge, because of their affection or because ambition is aroused towards a questioner. An observer really knows that to answer ' A ' or not to answer at all is contradictory to his own knowledge, but he does not venture to resist the question asked ; for he does not like to make himself disliked, or he fears punishment or some kind of annoyance. (33. p. 216.) Thus under certain circumstances, some observers conclude not to contradict directly, but also not to come in conflict with their own knowledge, and hence take an attitude of a compromise. (33. p. 231.) These affective reactions perhaps decrease with growing mental development and education. If this affection becomes stronger the suggestibility of an observer in general increases. " Whatever weakens the reason," says Cooley, " and thus destroys the breadth and symmetry of consciousness, produces some form of suggestibility. . . ." (18. p. 40.) So, too, Bleuler says that the suggestibility grows proportionately with the strength of an existent affection (7. p. 54), so that we find memory illusions even in the normal individual as soon as affection comes into play (7. p. 69). He continues: "Both suggestibility and affection render criticism difficult or check it even completely." (7. p. 69.) If an observer comes under such an influence, he becomes the unresisting instrument of a questioner. (58. p. 333.) He gives an answer to a question, but does not examine whether it is right or not ; he simply contents himself with a vague feeling that it may be correct ; he estimates the authority of the examiner higher than that of his memory. Similarly the ambition of an observer changes the quality and quantity of an answer to some extent. Franken (22. pp. 214 ff), Kosog (29. pp. 71-72) and others have shown that the ambition of an observer increases with the range of his knowledge, increasing the extent of an answer but reducing its qualitative value. The reason seems to be that with Closely connected with this group of reactions is a type of reaction traceable to the so-called counter or contrary suggestibility. This is a tendency to react, immediately, uncritically or critically, but always negatively, to the suggestion made. (39. pp. 372-374.) If such observers notice that a definite answer is suggested by a question, then they form the opinion that this answer will probably be false. There is an acute type of this contrary-suggestibility which may be termed an inborn contrary-suggestibility. Here the mode of reaction approaches almost the negativism described by Kraepelin as " the instinctive resistance against every outer influence upon the will" (8. p. 10). As soon as such an one gets suggestion, he feels antagonistic ; no idea suggested gives him any satisfaction and so he chooses something else, and the " something else " is apt to be the opposite, since " each idea suggests, as it were, a contrary idea as its natural complement" (8. p. 32). However this tendency in children is not rebellion or conscious assertion of the self against an opposing will. " It represents rather that stage in the normal process of selfdevelopment in which the crude materials of rational action have been given, but in which successful co-ordination has not yet become possible" (39. p. 379). "But to have become the characteristic form of reaction in an adult is an indication of arrested development, since in proportion as this type of action predominates, the mind becomes blinded to the very basis of rational conduct. It must be utilized to establish that habit of reflecting upon reasons for and against any suggested course of conduct" (39. p. 380). Besides those above mentioned, there are still at least two types of reaction due to exercise or repetition. A question draws the attention of the observer to a given problem and gives rise to an idea of purpose (Aufgabe) to solve it. This idea of purpose conditions a certain mental state which may be called " Attitude or a definite reaction mood " (Einstellung)^ (33. p. 77). This attitude or mood, after several repetitions of reactions to the same stimulus in a definite way, is apt to develop into the purely mechanical or expectant mode of reaction. The purely mechanical reaction or habit is found to play a great role in the well known abnormal or supernormal suggestibility of soldiers (50. p. 315), policemen, children and others, under strict discipline. Here the suggestibility is undoubtedly fostered by exercise. So, too, some observers are found very often to acquire the habit of either a motor or vocal reaction, to a similar stimulus. If children are habituated to react with an answer " yes " to a " yes or no " question, they will be mechanized to this mood of reaction, and will answer without reflection but merely automatically, even when the content of a question is entirely changed from true to false. To discover how an expectant attitude affects even normal questions, Lipmann (33. pp. 78-81) made another experiment which showed that the increase of error is greater in an experiment with a leading question as the first of a list of questions than in a series without such a question, which produces an expectant attitude towards the rest. Again an expectant attitude may affect suggestive questions in a peculiar way. For instance, after an observer has answered a number of normal questions in succession, he is apt to fall into the trap of a suitably formulated suggestive question, or questions where their suggestive character is not apparent (33. p. 77). In all these experiments it is hard to say how much of the results is to be ascribed to suggestive questions, and how much to an expectant attitude, but we may safely say that the expectant attitude has played an important role, since its function is to dull the critical power, which Rodenwaldt (50. p. 316) found stands in inverse ratio to suggestibility. There are cases, however, as in Seashore's experiments, where even the greatest caution will not ensure protection against skillful suggestion (56. p. 43). Children's suggestibility may be due also to their lack of attention, defective observation, lack of language, etc., or all these factors combined. It is thus difficult to say that a particular result is caused by a definite influence. It is a teacher's function to investigate the suggestibility of each pupil and to make practical use of such knowledge. ing to their purpose. 1. The preliminary or experimental question aims to find out what the pupil knows. The teacher, by means of this class of questions, is able to arouse a pupil's curiosity and intellectual activity (21. pp. 76, 81). 2. The questions employed in actual instruction, by means of which the reasoning power of a learner is exercised are analytical or developmental. The purpose of the analytical question is to analyze knowledge into its elements in order to bring its implications to consciousness (19. pp. 180), while the developmental question is to aid the pupil in arriving at a clear comprehension of classes, rules, principles, etc. It is especially applicable in the inductive approach to general truths, but equally serviceable in making verification of principles assumed (19. p. 181). These two types of question are generally employed in scientific studies or those which exercise reasoning power. Their aim is both to impart knowledge and to train purposive thinking. 3. The questions, through which a teacher tests her own work after a lesson has been given and ascertains whether it has been thoroughly understood, may be called disciplinary or ' examination questions.' 5. Another type of question aims exclusively at drill, the establishment of a sort of mechanical association, as employed, for instance, in language studies. Here the attainment of a prompt reply is the sole aim. This type of question is unfortunately abused in our school recitations and often applied to subject-matter for which it is unsuited. The most fundamental function of questions in most cases is didactic, that is, to stimulate thought in the direction of the solution of a problem, instead of mere verbal memory exercise, drill or habit-formation. It is to lead pupils to recall objects previously known, to bring to consciousness former experiences to give a new meaning. But unfortunately the belief in a " faculty of memory " has led popular educationists to an exaggerated estimate of the value of questions for verbal memory training. Certainly memory is a basal factor for all sorts of learning, as Miss Calkins says, " not only creative imagination but all forms of thought are based on memory." We are, however, skeptical of that sort of teaching which merely aims to equip children with a mass of fragmentary dissociated knowledge in order that they may later in life find a use for it. The teaching of children's memories must be based on rational understanding so that they may be able to control or direct their ideas toward some end, toward the solution of some problem. According to Stevens' investigation (65. p. 47), an average number of questions during a History lesson of one period is ninety-three, for English, eighty-five; of the former 76.6%, and of the latter 49%, are based directly upon the repetition of the text-book. For example: When was the battle of Waterloo fought? When was Scott born? What kings of England led crusades? Now what do such questions suggest to children? Will they not become merely an incentive to memorize by rote the words of the book, rather than to work out the problem and get ideas of their own? They do not stimulate reflection as do such questions as, for instance: Why do you like the Lady of the Lake better than Marmion? Why is it that Minneapolis could develop so quickly ? Compare the quality of A with that of B. By pure memory questions pupils become apparently but not really self-active. Thus Scherer even went so far as to say that the apparently greatest perfection in the art of questioning has as its result the greatest dependency of the pupils (54. p. 27). Over twenty-five per cent of the more than 300 returns to our questionnaire as to what school subjects were liked or disliked state that the writers liked English literature and History best, if the teachers did not bother them by silly questions on trifling facts and waste time without going into any interpretation or evaluation of the literature itself. This is clearly brought out in the following excerpt : " I have had experiences in English literature where we were driven to stand and tell from memory the names of authors, when they were born, where they were born, how long they lived, what books they wrote, when they died, where they died, where they were buried, and so on along the same line. I myself at least was bored to death. I wonder what such study of literature can amount to? Absolutely nothing to me, yes worse than nothing, as I changed my purpose." The burden that such a study inflicts upon pupils creates a hatred of literature often never overcome. The problem naturally arises, what questions then shall be used? The answer is: analytical and developmental questions, whether the method used be Socratic, inductive or deductive, topical or dialectic. Dr. Dewey says that " a demand for the solution of a perplexity is the steadying and guiding factor in the entire process of reflection" (20. p. n). It becomes thus a function of questions to present this demand for the solution of a definite problem as a first step. A general appeal, however, to a child to think, irrespective of his own experience or knowledge is futile. Experience is the anchor of both wisdom and sanity (13. p. 64). Given a problem, the next step is to stimulate thought by a series of interrogations leading each pupil to correct reasoning. This method may, in a certain sense, be called Socratic, but not in the sense which Socrates himself used it. Care should be taken in the use of the so-called Socratic method ; for it is primarily intended for adults who have much experience, and moreover it is, in its nature, altogether too destructive. Consequently it is likely to force the mind to think along a negative rather than a positive line or to lead to indifference. We may, however, make use of it by rendering it simpler and more constructive (28. p. 376). The teacher stimulates and directs, but never suggests a conclusion or an answer. Pupils are encouraged to present their own thoughts. If correct, the teacher deepens and widens their views by suggestive illustrations. If incorrect, their absurdity is shown by leading them to discover legitimate consequences. Thus the leartier at every step feels the joy of discovery and victory instead of discouragement. In all this the teacher is only the stimulator of the pupil's thinking. The secret is: " never suggest, anything which you can lead a pupil to find out and tell you." Given a problem, suggestions in the mind of the child follow the laws of association. The greater the fluidity of ideas, and the greater the number of the suggestions that arise, the more likely is the fcrue solution to be obtained ; but all these may fail ; then only may a questioner suggest the conclusion. If any suggestion of an answer is given from without and accepted at once, there will be no critical thinking, simply a minimum of reflection. If this kind of interrogation continues for months and years, the child will become a puppet and passive in his thinking, instead of active, self-assertive, and independent of external suggestion. Another pernicious practice is that of helping or directing pupils too much in their recitations by questions or otherwise. They are never left alone to direct their own steps, and are never afforded any opportunity of self-direction to develop sufficiently the power of initiative. Should it then be a matter of surprise that when left to themselves to think and to decide or solve a problem, they dawdle and get nowhere? Another method of developing the power of purposive thinking in a pupil is by means of dialectic or discussion. In this method, the pupils present their arguments briefly and pointedly in favor of their respective positions. All criticisms are answered and contested. The reasons for and against are carefully weighed. In these mental conflicts, the utmost power of the pupil is called forth. It not only cultivates mental power, but also self-assertion, independence, courtesy and liberality toward an opponent, and the virtue of fair play. It supplements the so-called Socratic method, by making the pupils think. Of course this method is not applicable to young pupils, but to a certain extent and in somewhat modified form the high schools. Here it may be instructive to cite an experiment by C. H. King (27. pp. 158-9) on the reasoning powers of children. He gave the following two questions to children of from twelve to fifteen years of age. " The first question runs : There are several clever boys in this class and they are all careless, so a clever boy must be careless. Do you agree with this? The second question is: French people are excitable, so are Italians; so all foreigners are excitable. Is this true? The first question was solved correctly by 144 (44.4%) of all the children who answered, and the second by 172 (56.8%). He concludes that a considerable portion of those who have received a good education and. have reached the age of fifteen years fail to show anything but the germs of logical thinking " tainly not. The habit of reflecting upon the reasons for and against any problem should be promoted by a kind of dialectic method. By a series of suitable questions the pupils are led not only to pause before they react, but also to review or analyze the complex system of factors involved in the case, so that their reaction is made deliberate and rational; otherwise they become mere empirical thinkers, of whom, James says: " Whereas the merely empirical thinker stares at a fact in its entirety and remains helpless or gets ' stuck ' if it suggests no concomitant or similar, the (analytic) reasoner breaks it up and notices some one of its separate attributes. This 'attribute has properties or consequences which the fact until then was not known to have, but which, now that it is noticed to contain the attribute, it must have." MacDougall says : " The ideal type of human action, which all conscious education seeks to develop, is that in which each novel situation is critically reviewed as it arises before it is responded to by an adaptive reaction (instinctive reaction) " (39. p. 381). Questions may also be utilized to disclose the intellectual or emotional bias of an individual so that reactions or answers may be given without prejudice (34. p. 28). According to Freud, " our mental processes are more rigorously determined than is commonly believed, and many of them generally thought to be causeless have in fact a very precise and definable cause. The same remark applies to many mental processes where we believe that we have a perfectly free choice. Most important, however, is the extension of these principles to the sphere of human judgment, for it is probable that repressed complexes play as prominent a part in distortion of our ideas. On a large scale this is shown in two ways, in the minimum of evidence often necessary to secure the acceptance of an idea that is in harmony with existing mental constellations, or to reject one that is incompatible with these. In both cases it is often the affective influence rather than the intellectual operations that decides the question. The same evidence is construed quite differently when viewed in the light of one affective constellation than when viewed in the' light of another" (25. pp. 478, 524). Wrong ideas and inappropriate propositions enter consciousness through many doors and should be corrected by the influence of opposite ideas which a faithful memory and a sound reasoning provide (43). But if pupils are not trained to look into things, to reflect for and against a given problem, and to judge it fairly, they will be at the mercy of their instinctive reactions and feelings. THE QUALITIES OF GOOD QUESTIONS It is of prime importance for a teacher to provide a certain .mental background necessary for the lesson and harmonize it with her own so that both pupil and teacher may have a closely similar apperception, though not composed of the same elements (2. p. 95). Otherwise a problem under consideration may be looked at from wholly different points of view and there may be a mutual failure in understanding. This is the reason why the teacher so often fails to get correct answers from her pupils. For instance : " Where was St. Paul converted?" asks the teacher, speaking from a geographical point of view ; but the pupil responds, " In the ninth chapter of the Acts," from a background of textual reference (2. pp. 9596). Hence the necessity of bringing the teacher's own mental background into harmony with that of her pupils in order that the questions may be comprehended and answered correctly. Moreover a question should be clear, concise and logical. The first requisite is its clear comprehension. If the question lacks clearness or is ambiguous, it occasions hesitancy and confusion, so that some children may decline to answer, even when they know the answer well. " An Ohio school teacher asked of her class one day a question, but did not draw the prompt response she expected. ' Johnnie replied, ' I know what you want all right, but you ain't asked the question what fetches it." Here the youth, wiser than the Questions should neither be too universal nor too general. For instance: "Where is Chicago?" may bring out the answers — ' In Illinois,' ' on Lake Michigan/ ' in the United States,' etc. All these answers have equal value for such a question. All these vague questions admit of several equally good answers, according to the different points of view from which different minds regard them; but many teachers think that what is clear to them ought to be equally clear to others, so that when an answer is given contrary to their expectation, it is rejected, even though a perfectly legitimate one; while, if any pupil is fortunate enough to give the precise answer in the teachers' mind, he is commended and rewarded, even though he has given no more thought to the subject (21. p. 91). The really thoughtful and cautious child is merely bewildered by such questions. He remains silent and will be disgusted when an answer is given by his less worthy comrades. The second type is the pupil who is not very clever but shrewd as to the personal peculiarities of his teacher, watches her facial expressions, tone of voice, method and mode of questioning, etc., and discovers easily what she expects. The third type of learner takes a chance by answering at random without thinking it over. He is thus led to form a habit of guessing and insincerity. Great simplicity of language is another condition. It is better to use as few words as possible, since the function of a question is not only to cause children to say as much as possible, but to avoid confusion, and a loose, pointless answer which is apt to result from a wordy question. The questions should be adapted to the mind and experiences of the child. An intelligent teacher usually knows in advance which pupils can answer her questions, and this makes possible adaptation of the questions to the pupils. But, unfortunately, it too often happens that a teacher tries obstinately to elicit from the pupil's mind what is not in it. Whenever the question fails to fit the mind of the learner, it presents difficulty after difficulty, and causes embarrassment and confusion, which will cause some pupils to give up all attempts to reply and lead others to imitate their comrades or to reply at haphazard. One girl says : " When I was in the eighth grade, our teacher used to ask such bewildering questions that most of the class could not understand, but she insisted upon our thinking until we hit upon what she had in her mind. If we did not at once hit upon her thought, her eyes became large and black, her voice harsh and her manner made us feel as though we were the most unintelligent beings possible and as a consequence we became nervous, and gave up any attempt to solve or answer the questions." Examples of such bewildering questions can be found in many educational writings, and we cite a few of them here. Betts says : One teacher asked, " Which phenomena of the fratricidal strife in the American Republic were most determinative of the ultimate fate of the nation?" While in an elementary history class, another teacher propounded this question : " What American institutions have been founded on the principle of social democracy?" (4. pp. 66-67.) Now in all these questions not only the terminology, but the thoughts also are beyond the comprehension of the children. Such questions are not only useless, but confuse and discourage the children, and cause them to lose interest in study. How difficult it is to adapt questions to children is clearly seen from the following examples given as a model by a college professor in one of the largest American universities : " How long do you think it would take a man to walk to the top of a mountain? What would be the difficulties in getting to the top? If you stood on the top and threw a stone, how far down the mountain do you think it would go ? " To the writer who was brought up among the mountains, such questions sound nonsensical. Undoubtedly with many pupils under the conditions created by a series of ill-adapted questions, the brain becomes inhibitive or a storm center of opposing nervous impulses and the mind loses all docility. The following investigation may throw some light upon this point. In 1909, Miss Helen Todd (67. pp. 73-74) took 500 children from twenty different factories and asked them the question : " If your father had a good job and you didn't have to work, which would you rather do — go to school or work in a factory? " Four hundred and twelve said they would rather work in a factory and gave among others the following reasons : " Because it is easier to work in a factory than it is to learn in school ; " " You never understands what they tells you in school, and you can learn right off to do things in a factory ; " ;< They ain't always picking on you because you don't know things in a factory ; " " It's so hard to learn ; " "I couldn't learn ; " " When you works a whole month at school, the teacher she gives you a card to take home, that says how you ain't any good." These cases might be diminished by well-adapted questioning which will give a child success and hence pleasure and an incentive for further attempts. Every teacher has noticed with what enthusiasm and vigor children take up different tasks in their school lessons after they have been successful in the solution of some problem. " Not all the coaxing, or scolding, or moralizing in the world would fit them half so well to take up the new work, as the victory already won " (12. p. 112). Belief in power begets power, in weakness, begets weakness. Upon self-confidence depends the mental development of the child (47. p. 267). Hence it is important for mental hygiene to give children a chance for success, and to arouse selfconfidence in their ability; and this is the very task of questioning. It goes without saying that it is also important to allow a slight failure once in a while as a specific medicine. Meumann illustrates the importance of the self-confidence of a child in his own power from the experience of a boy whom he knew. When a thirteen-year-old boy entered a new school, his previous teacher who had an antipathy to him, introduced him to the new teacher in a tactless manner with false report From that moment the boy, who so far had done work above the average, could do nothing more, his intellectual efforts diminished from day to day, behavior deteriorated, and he became shy and depressed. At the end of the year he failed to be promoted, and would have gone to pieces, had not his parents taken him away. In the new school he met a teacher who showed confidence in him, and from that moment he changed completely, and left the school as one of the best pupils. Meumann gives this case as typical in that a single definite volitional inhibition entering into the life of the child, extended to his whole inner nature, discouraged his self-confidence, depressed his affective life, and decreased all his performances intellectual as well as moral (42. p. 298). The effectiveness of such a volitional inhibition is most easily observed in the psychological laboratory-tests on immediate retention (42. pp. 298-300). We cite also one of our questionnaire returns. A girl writes : " Behind the teacher's tones and expressions I have usually been able to read her attitude to the class and towards myself. When I know that a teacher has entire confidence in me and expects a certain response on my part, the most difficult subject becomes easy to me. On the other hand, when a glance tells me that my ability to answer is questioned, no matter how carefully the lesson has been prepared, my power over the subject seems to depart, and I fail in general." Children are very susceptible to such volitional inhibitions ; and such an inhibition is too frequently caused by ill-adapted questions which simply bring about failure after failure, or by the unsympathetic sarcasm of the teacher or the like. QUESTIONS SHOULD NOT BE NUMEROUS A multiplicity of questions is likely to discourage and fatigue children because of the monotony of the procedure. According to Stevens' investigation, already referred to, the number of questions in one recitation period is, on an average, 85.3 for English, 81.2 for History and 81.4 for Science. That is, the children are asked about two questions per minute. Embarrassment, repulsion, constraint, weariness, etc., will often be the outcome of such a method of numerous questions, as the following excerpt illustrates : " There is one teacher who asks question after question and does nothing else for a whole period ; and everything becomes monotonous and one feels really wearied so that one can not understand what is going on." Another girl says : " As a result of too many questions we become indifferent ; " still others say that they become nervous and impatient. Effectiveness and leadership in social life depend on the ability to express one's self adequately on the topic under consideration. But in the schoolroom the number of questions, whether good or bad are apt to be so large that there is no time left for complete expression of thought. The pupils are allowed merely to punctuate the questions with monosyllabic answers, or with a few words. The following example from a lesson on " The Lady of the Lake " will illustrate the point (65. pp. 38-42, 66). The number of questions asked in one recitation period was 105 out of which 60 were answered with less than five words: and so on. The questions should be made so that every child may have frequent incentives to answer in well-articulated sentences. Dr. Lay says (32a. pp. 303-4) that "too great emphasis has been put upon questioning without thinking, that in the schoolroom is fostered a form of conversation that has an analogy in the court room alone. He further says : ' The natural form of conversation should be preserved in the schoolroom, especially, since the question is unpleasant or even painful to most children. The child must have freedom to follow his own thought process, not that of the teacher." And for this purpose, description, narration, and exposition, or in other words, the method of our spontaneous report is very desirable. We are, however, by no means inclined to slight the questions and questioning, but simply to guard against the use of too many fragmentary questions. An interchange of all these methods of description, exposition, narration and good questions contributes to freshness and interest. It is, of course, too much to demand a complete sentence for every question, and again it is pedantry to banish all questions that can be answered by " yes " or " no." We need, however, to be sure that a sufficient reason follows or precedes the answer, so that the ' yes,' or ' no ' may neither be a mere guess nor an automatic expression. Here it may be worth noting that the teacher who accepts vague and indefinite answers incidentally encourages slovenly habits of thought and fosters guessing. A child is quick to take advantage of the teacher who will accept any sort of an answer and interpret it as a statement containing thought. Indeed, a child may even come to think that his incoherent statements, his word juggling, really represent thought (66. pp. iio-m). Worse than this is the danger that a teacher may lead the child to insincerity of speech. Instead of truth, he will have appearances ; instead of real powers, presumptuous weakness; instead of sincerity, hypocrisy. Again, it seems even better to permit the pupil to blunder through to the end of his recitation and correct him than to disturb him in the midst of his speech. A Normal School girl says: "A certain teacher I once had was very impatient. Before I would go to the room I would know the lesson almost word for word. When she called on me to recite, if she did not interrupt me, I could finish the recitation, but as soon as she began to ask many questions and then scold if they were not answered correctly, I would forget the work which I had before known so thoroughly, and as a result would fail." (Thirteen cases.) Moreover the method of numerous questions means that things and their qualities are torn apart, retailed and detailed, without reference to their more general character, and thus the child is not only hindered from seeing the " forest on account of the trees," but also the firm retention of the subjectmatter is rendered very difficult (20. p. 97). TIME SHOULD BE GIVEN FOR ANSWERING Rapiditv in questioning intensifies the attention of children to great advantage and is undoubtedly necessary for pedagogical purposes, but its dangers should not be overlooked. First of all, speedy questioning emphasises the quantity instead of the qualitv of the work. When a teacher demands of each pupil to answer quicker than the other for the sake of a brilliant showing, a premium is put upon feverish activity, regardless of the cost to the pupils. According to the experimental results of Hillgruber (i), Rusk (52), Meumann and others, under the compulsion to work as quickly as possible, the amount of work will be far greater than that obtained without such force. Ach (i. p. 2) says: " It is due to the law of difficulty as motivation, that is, to the fact that the difficulty of a forced task motivates a more intense effort of Will and concentration of attention on the present problem." " With the increase of the difficulty," he continues further, " the effort of Will increases instinctively and acts in favor of the work quantitatively." But another aspect of their experimental results confirms our theory as well as Meumann's that under the influence of the compulsion to work as quickly as possible the quality of the work deteriorates. This is certainly due to the interference of association caused by excitement, confusion, lack of time, etc. It is obvious that sufficient time is needed to comprehend the questions correctly and to make correct comparison, discrimination, and true inference as well as call forth right associations or to make orderly associations with the old. The child needs a longer time for individual ideation, and the ideas with which the child works are not at prompt disposal for him in spite of his accurate possession (42. p. 231). Meumann found from his experiments that when rapidity of response is a controlling factor, a stimulus word is comprehended in the most cursory fashion, so that the reproductions are of little value, but with lengthening of the reaction time in general is noted an increase of the qualitative value of the work. He concludes that for tests with a problem to be solved, the instruction " as quickly as possible " is detrimental (42. p. 232). The results of Rusk indicate that for different children the speed of association has little value as an indication of the intelligence of the learner (52. u. 102). The children who reply most quickly are not necessarily of the highest intelligence. An exceptionally good memory is often found to co-exist with very low intelligence (52. p. 151). On the other hand, Muller and Pilzecker, and Bigham (5. p. 458) also, found that right associations are reproduced more quickly than false; in other words, those ideas which can be reproduced easily are usually truer than those whose recall is difficult, whether this be due to pure forgetfulness or to the confused association with kindred ideas. This again shows that questioning should not be too speedy, since speedy corrected and cleared. The experimental results of Franken (22. pp. 239-243) tell us that the lengthening of the time for reflection (Bedenkzeit) brings about a quantitative increase but a qualitative degeneration, since the increase of right answers is smaller than that of false ones. This result apparently contradicts our theory, but a closer study shows that there is no conflict, but agreement. In Franken's experiment, the observer gave only those answers that were most clear and certain to him, and with the brief interval for reflection, all doubtful answers are rejected. (22. pp. 227-229.) Furthermore his result shows, that the mean variation varies with the length of the time for reflection; it increases if the time is lengthened and decreases if this is shortened ; that recollection needs a certain time, and if, before its process is complete, questions and hence ideas and answers, crowd themselves in consciousness, the recollection will be disturbed and hindered (22. pp. 227-9; 24i). Second: rapid questioning ignores individual differences (59. p. 215), and consequently fosters shallow thinking or guessing. What one pupil solves in a second, another may spend a minute in solving (3. p. 243). Meumann says that : " The concrete thinking of a child is surprisingly slow ; in some cases, he takes almost ten times as long as the adult to respond to a stimulus equally familiar to both " (42. pp. 227-8). Children who are more ambitious are apt to answer more quickly than others. Temperament also makes a great difference. The results of Rusk's experiments also disclosed great individual differences in the rates of reaction. For example, an investigation with three boys of the same age and intelligence revealed the fact that one of the boys invariably took three times as long as the other twa to respond to the stimulus words. The work presented no difficulty, yet his normal rate of reaction was considerably slower (52. pp. 102-3). The teacher of these three boys, although they had been under his care for years, was unaware of any sucu difference, and probably, in oral questions, this boy owing to his slower rate of response, would appear at a disadvantage (53. p. 837). Bader (3. pp. 102-104) obtained similar results, among his five observers those whose reaction-time was shortest gave the poorest answers. Furthermore, what effect does a demand to answer " as quickly as possible " have upon the mind of the child ? Bader's experiment teaches us that the observer focuses his attention on the act of answering quickly as a result of pressure. Thus those whose natural disposition forces them to a quick reply are still more incited by the stimulus and give flippant, unconsidered answers, while those who are by nature reflective feel in the procedure an unaccustomed impulse (3. pp. 243-4). In both cases, as a result, quickness of solution takes place at the cost of quality. To make these results clear, let us cite a few introspective reports of Bader's observers : observer E says : " The task of replying quickly influences consciousness and drives me to do so." Observer F says : " The idea, ' you must reply as quickly as possible/ is always very vivid and governs everything else/' F further says " I do not know why I have said that word. Oh, yes, in an endeavor to answer as quickly as possible, I did not take time to give a sentence, but brought quickly merely a word." B says : " I would have answered differently. At all times I was clear that it (the answer) was false, but I thought that I needed too long a time to do otherwise; and hence I spoke so quickly" (3. p. 100). Any demand for speedy reactions deprives a child of time for suspension of judgment and weighing the evidence pro and con; it prevents him from appealing to concrete experience latent in his mind, but encourages him to accept any suggestion from within as well as without and to react at random. As a result such a method may bring about mental automatism, a habit of instinctive, premature reaction. We should keep in mind that the class room is not a vaudeville stage for displaying or rehearsing the mere strength of verbal memory, but a laboratory for testing, getting, verifying, using and developing knowledge, in a word, for the training of purposive thinking. It is the function of questioning to make children understand first of all the meaning of the question and to make an orderly association between the question and ideas in the answer. A question erroneously comprehended may not only evoke the wrong answer but may also cause an interference of association. Now it happens quite often that when a question is asked under the spur of answering quickly, many children raise their hands first and then think about the problem. The answers are given frequently before the question is fully understood. With frequency of such a mode of questioning and answering, the child may finally become habituated to a mode of thinking in which the attention, critical insight and examination of the inner process present between the question and answer is neglected. It is a matter of course that when questions are put for the sake of drill or of the review upon memorized matter, they may be asked with emphasis and rapidity ; but even then, the individual differences in reaction time and the influence of the command to answer " as quickly as possible " upon the observer should be kept in mind. A large number of rapid questions is injurious both to mind and body. As Stevens says, " a large number of rapid questions keeps children in a highly strung nervous tension where there should be natural and normal conditions (65. p. 171). It is certainly injurious to the nervous organism to live in such a high-pressure atmosphere." One girl says : " One of my teachers by her mode of speedy questioning causes me to put all of my mental powers on the questions in hand. After spending an hour with that teacher I feel really tired and nervous so that I can not do anything until I have time to recover from my nervousness." Another girl reports : " There is a teacher who affects me very much. When I enter her room I am as calm and composed as anyone else should be, but when I leave it I am worked up to such a nervous pitch that I am almost unable to go on with the work of the next hour. It is caused, I believe, by the teacher's incessant calling upon us for answers and recitations." (Seventeen cases.) Some individuals can do mental work with far less waste of energy than others even under pressure, but most of us are apt to be made nervous and excitable by undue nervous stress. In some cases, excitement, fatigue and anxiety may cause the beginning of pathological neuroses. A girl reports: "At one time I had a teacher who was extremely nervous. When she called on her pupils for answers and recitations, she hardly gave them time to recite or answer by calling for answers, but she would supply words; and just by her whole manner and her mode of questioning she made her pupils so nervous that some forgot everything they knew, some became restless and some of my classmates gave way even to the nervousness in spells of crying." It is especially noteworthy that this speedy habit of reaction and thinking formed by such a method may persist even till late in life and hinders the victim from quiet, deep, and connected thinking. Some teachers may say that the ability to concentrate attention on a problem should be cultivated, and hence speedy questions must be used. It is certainly true that the attention of a child is very likely to be dulled by even a few minutes' exposition and that it is aroused by animated questions; but we must not forget that a multiplicity of speedy questions also tires and disgusts the children. After a few minutes, their attention again flags; they will no longer listen to the inquiries of the obstinate questioner, and they will answer only at random, thanks to the defensive mechanism of nature. Hence the method of rapid questioning will rather kill than form the habit of attention. Attentive moment and relaxation-moment should alternate. Above all, it is desirable that attention be paid to the meaning of the question and to the quality of an answer, not to the form of the question nor to the teacher. Too slow questioning is, however, detrimental for the education of the will (i. pp. 3-4). The best method may, as Ach suggests, be to let children work at times under the spur of obtaining good results as quickly as possible but with intervals of relaxation. This method conditions an increase of the effort of the will and brings about the best result both qualitatively and quantitatively (i. p. 3). Still another point to be considered is that sometimes even the brightest children and some adults too fail to answer in spite of knowledge, when asked a question suddenly, unexpectedly, or at an examination. The writer's own experience and observation show that such a question causes a sudden arrest of psychic activity, or that there arises out of unconscious complexes an apparently unrelated idea. Thoughts refuse to flow freely, only to lead one to an utter failure, even when well prepared in the subject. The nerve centres for the time seem paralyzed; as soon as one is alone or with a sympathetic friend, the obstruction gives way, and clear-cut correct answers which he might have given in reply to the questions raised are readily thought of. Psychologically such a sudden mental arrest may be due to fear, excitement, a feeling of unpreparedness, lack of selfconfidence, timidity, shyness, embarrassment, or excessive ambition. Whatever the cause may be, the fact remains the same. It is absurd to judge children's mental ability through the answers to such questions. Moreover a failure may injure their future work through volitional inhibition. In conclusion it may be wise to add that for individuals who have a normal nervous system, adequate nutrition and abundant rest, and especially plenty of sleep, excitement and explosion of energy once in a while may be as essential as rest and the storing of energy. Normal children must be trained to work occasionally under pressure so as to be prepared for the struggles of their future life. To shield pupils entirely from tests of strength is to rear them in weakness and timidity (44. p. 118). Finally, the limits which should be observed in the rate and tempo of questioning and in regard to the functions of questions in general, that they may be useful and not harmful to mental development are problems to be studied seriously by every teacher. those of others give the following tentative results : 1. Children attempt the Bericht with a different mental attitude from what they have toward the Verhbr; for example, some children reported correctly in the Bericht what they answered wrongly in the Verhor, while other children make false statements in the Verhor in regard to what they reported correctly in the Bericht. 2. The weakness of the Bericht seems to be the outcome of three factors, (i) Pedagogically, it appears to be due to passivity of the mind induced by habituation to the questioning method and lack of initiative. (2) Psychologically, it may be due to interference or weakness of association that children fail to recall in the Bericht what they can by the aid of questions. (3) It is undoubtedly in part due to the fact that children's interest is not equally distributed to each detail, and hence they fix their attention on the more interesting facts. 3. The large number of errors in the Verhor is due not only to the passivity of the mind and the suggestive character of the questions, but also to the fact that children's mode of viewing things is wholly different from that of adults, while the questions are asked from an adult point of view. 4. The experimental results show that many children can do better in the Bericht than in the Verhor. In view of this fact is it justifiable to determine the grade of children by the questioning method alone? should go hand in hand. 3. All questions, whatever their form, have a suggestive influence ; and hence children should be trained to guard against suggestion and to react to the content and not the form of questions. 16. COHN, JONAS, and DIEFFENBACHER , J, Untersuchungen iiber Geschlechts-, Alters- und Begabungs-Untedschiede bei Schulern. Zeit. f. ang. psychologic u. psychologische Sammelforschung. Leipzig, 1911. Beiheft 2, pp. 2-15, 50-98, 188-211. scheidungs-und Bestimmungsfrage bei Erwachsenen und Kindern. Zeit. f. ang. psy. und psychologische Sammelforschung. 1912. Vol. 6, pp. 174-253. APPENDIX The questions used in the experiments described above are based on the section (p. 259) on the Guianas in C. C. Adams' Elementary Geography and the section (pp. 18-19) on the Surface of South America in A. E. Frye's Grammar School Geography. " The Guianas: The three Guianas (B. D. and F.), are mainly devoted to the growing and manufacture of cane-sugar and its by-products, rum and molasses. Cultivation is confined almost wholly to a narrow coast strip, where most of the people live. Owing to the decline in the price of sugar the British and Dutch planters are replacing sugar-cane to some extent with coffee and cacao. An important amount of gold is mined in the interior, the British producing the larger part of it. Georgetown and New Amsterdam, the chief towns of British Guiana, owe their importance to the palmy days of the sugar trade. Great Britain and the United States take nearly all of the exports of this colony — sugar, gold, rum, rubber, rice, and molasses. Great Britain supplies half and the United States one fourth of the manufactures, food, and coal imported. Paramaribo is the commercial center of Dutch Guiana, nearly all of whose trade is with the Netherlands. French Guiana (port, Cayenne) is less developed than the other colonies, and includes phosphates among its exports. Its trade is mainly confined to France." 133. Isn't French Guiana less developed than the other Guianas? I3b. Isn't French Guiana more developed than the other Guianas (other colonies of the Guianas) ? South America has the shape of a triangle towards the south. Its coast is not so broken as that of North America. In general the surface of South America resembles that of North America. Each has its greatest or primary highland on the west, with lesser highlands on the east, and a great plain between. The highland which lies along the west coast of South America is known as the Andes highland, or simply the Andes. It is not nearly so wide as the Rocky mountain highland, but it has much higher plateaus. Over the eastern part of South America spreads a low but broad plateau, not nearly so high as the Andes. This plateau is mainly in the eastern half of a country called Brazil and is known as the highland of Brazil. The western half of Brazil is part of the Central plain and contains vast forests called selvas. Most of the trees grow in the lowlands along the rivers that form the Amazon system. The Amazon river and its branches drain the largest river basin in the world. The selvas are in this basin. Most of the largest rivers of the Amazon system flow from the Andes highland. The part of the Central plain south of the selvas is grassy and supports millions of cattle and horses. In that land such grassy plains are called pampas. The parts of the Central plain north of the selvas are called ' llanos,' meaning level land. There also the people raise many cattle. 24. Which half of Brazil is a part of the central plain? 243. Is the western half of Brazil a part of the central plain? 24b. Is the eastern half of Brazil a part of the central plain AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE.	28,111	common-pile/pre_1929_books_filtered	studyofquestioni00yamarich	public_library	public_library_1929_dolma-0000.json.gz:82	https://archive.org/download/studyofquestioni00yamarich/studyofquestioni00yamarich_djvu.txt
TUWDrNOMreqPCKeR	Psychology of Language	2.4 Vowels Vowels are produced without any obstruction to the articulatory tract (Ladefoged & Maddieson, 1996). Unlike consonants which result from the contact between articulators, vowels allow for a free flow of air. Therefore, we cannot define vowels in terms of place and manner of articulation. Rather, we define vowels in terms of the shape and position of the tongue. This means that while consonants in different dialects of a language remain relatively constant, vowels can differ widely. The defining terms for vowels are height, backness and roundness. Height refers to the vertical position of the tongue. Try saying ‘ee’ and ‘aa’ repeatedly. You will notice your tongue moving up and down. Therefore, we say that the vowel produced in saying ‘ee’ is a high vowel and that produced in saying ‘aa’ is a low vowel. Backness is based on the tongues horizontal position and shape. This is can noticed in saying ‘ee’ and ‘oo’ where the latter makes the tongue go back. Roundness is not a property of the tongue but of the lips which you will notice in making sounds such as ‘oo.’ Table 2.6 shows you the vowels found in English. \| blank \| Front \| Central \| Back \| \|---\|---\|---\|---\| \| Close \| i [audio] \| blank \| u [audio] \| \| ɪ [audio] \| blank \| ʊ [audio] \| \| \| Mid \| e [audio] \| (ɜ) [audio] \| o [audio] \| \| ɛ [audio] \| ə [audio] \| (ɔ) [audio] \| \| \| Open \| blank \| blank \| ɑ [audio] \| \| æ [audio] \| ʌ [audio] \| blank \| Some languages such as French and Hindi also have nasalized vowel. Consider beau /bo/ ‘beautiful’ and bon /bɔ̃/ ‘good’ in French being minimal pairs in terms of nasalization of the vowel. When two vowels are combined within a syllable, they form diphthongs. These can be seen in words such as cow /kaʊ/, pie /paɪ/, and boy /bɔɪ/. \| IPA Symbol \| Name \| Example \| \|---\|---\|---\| \| /æ/ \| Near-open front unrounded vowel \| trap [audio] \| \| /ɑ/ \| Open back unrounded vowel \| lot [audio] \| \| /ɔ/ /ɑ/ \| Open-mid back rounded vowel \| caught [audio] \| \| /ɪ/ \| Near-close front unrounded vowel \| bit [audio] \| \| /i/ \| Close front unrounded vowel \| geese [audio] \| \| /ɘ/ \| Close-mid central unrounded vowel \| about [audio] \| \| /ʌ/ \| Open-mid back unrounded vowel \| gut [audio] \| \| /ɛ/ \| Open-mid front unrounded vowel \| bet [audio] \| \| /ʊ/ \| Near-close near-back rounded vowel \| foot [audio] \| \| /u/ \| Close back rounded vowel \| moose [audio] \| \| IPA Symbol \| Example \| \|---\|---\| \| /eɪ/ \| face [audio] \| \| /oʊ/ \| goat [audio] \| \| /aɪ/ \| nice [audio] \| \| /ɔɪ/ \| choice [audio] \| \| /aʊ/ \| south [audio] \| Watch the video Diphthongs (3 minutes). Table 2.7 and Table 2.8 show us the vowels found in most varieties of Canadian English with examples. While consonants tend to be similar across dialects, vowels can vary greatly between dialects and countries. Therefore, you will find that the English spoken in the United Kingdom, Australia and New Zealand will have very different vowels when producing the same words. Media Attributions - 2.8 Dipthongs video by Essentials of Linguistics is licensed under a CC BY 4.0 Licence. The quality of the vowel on the tongue’s vertical position. The quality of the vowel on the tongue’s horizontal position. The quality of the vowel on whether the lips are rounded when producing it. Two adjacent vowels that are within the same syllable. A pure vowel sound.	795	common-pile/pressbooks_filtered	https://opentextbc.ca/psyclanguage/chapter/vowels/	pressbooks	pressbooks-0000.json.gz:20915	https://opentextbc.ca/psyclanguage/chapter/vowels/
Y3sYYawS1_JFfuWl	A mechanical and critical enquiry into the nature of hermaphrodites	A Mechanical and Critical ENQUIRY INTO THE NATURE OF HERMAPHRODITES BY _JAMES PARSONS, M.D._ Fellow of the Royal Society. _LONDON_: Printed for J. WALTHOE, over-against the _Royal-Exchange_ in _Cornhill_. M DCC XLI. To the HONOURABLE Sir HANS SLOANE, Bart. PRESIDENT, And to the COUNCIL and FELLOWS OF THE _ROYAL SOCIETY_ OF _LONDON_; THIS MECHANICAL and CRITICAL ENQUIRY Into the NATURE of Hermaphrodites, _Is Humbly Dedicated, By their most Obedient Humble Servant_, JAMES PARSONS. THE CONTENTS. _INTRODUCTION._ _Containing some historical Observations of Laws and other Occurrences about Hermaphrodites._ Page xi CHAP. I. _Reasons against the Existence of an hermaphrodital Nature in human Bodies._ 1 CHAP. II. _An historical and critical Account of the Causes of Hermaphrodites._ 38 CHAP. III. _A general View of other Authors concerning Hermaphrodites._ 79 CHAP. IV. _CONCLUSION._ _Containing a Description of a Fœtus, and a Recital of the Dissections of such Subjects, by some other Authors, ~&c.~_ 144 THE PREFACE. If the following Sheets are not thought so methodically digested, as some Criticks would require, yet, it is to be hoped, they may conduce, in some Measure, to the reforming of an Opinion, which, in general, is the Result of Doctrines, founded by the Ancients upon the most absurd Principles; and though (if I may use the Words of the great Dr _Mead_) “[1]I do not promise methodical and finished Treatises, but only some short Hints of Natural History, and rude Strokes of Reasoning;” yet I have this for my Plea, that the Expulsion of superstitious Mysteries and Errors, occult Causes, and, in fine, the Promotion of Truth, in some Parts of Natural Knowledge, to the utmost of my Power, are my sole Intention. At first I only designed myself the Honour of laying a few Thoughts before the _Royal Society_, concerning the Nature of such as are generally called _Hermaphrodites_; with a Description of a female Fœtus that came to my Hands, which is hereafter mentioned; but upon communicating my Design to some Gentlemen of Learning, they were of Opinion, that it was quite necessary to examine what Authors had said on that Head; which, indeed, opened a larger Field than I could have imagined, and lead me on to swell this Essay to it’s present Size. Some, perhaps, may ask what I have said in this Treatise, that they did not already know? or may pretend, they did not believe there were Hermaphrodites in the World; to this I answer, that tho’ there are some who will give their Reason leave to interfere when a mysterious Matter comes before them, yet of those few who may be called the learned among Men, how many are there that follow the Path of vulgar Errors, rather than take the Trouble of thinking seriously about such a Subject? and, consequently, how few must they be, that ever had a Notion of what appears, in the following Introduction, to have been transacted concerning Hermaphrodites in all Ages and Nations, by the wisest and most learned among them? so far therefore this Undertaking cannot be quite useless. The Quotations through the whole are genuine and faithful, taken for the most Part from the Authors themselves, very few excepted, which, for want of the Originals, I was obliged to others for, who had cited them on different Occasions, but, however, were Authors of good Credit; and which are made _English_ here, for the Benefit of such Readers as have not had a due Instruction in the Languages of the several Authors from whom they are taken. As some Words are often repeated through the whole Essay, I could not avoid taking the Liberty of forming the adjective Word _Macroclitorideus_; which, tho’ not in Use before, as I could find, is highly necessary here for two Reasons; first, because it is a short Way of expressing what, in _English_, would be a considerable Sentence; and, secondly, a much more decent Term, which I have endeavoured to keep up to all along, where the _English_ Word might be less agreeable; therefore since it is calculated for these Ends, the Freedom of adopting it may be excusable, if it should amount to a Crime in any one’s Opinion. The Introduction sufficiently points out the Necessity of exhausting this Subject, in the Conviction of those erroneous Notions, propagated from Time to Time, and so long entertained in the World; and the best Manner that occurred to me of proceeding in it, in Hopes to succeed, was, after exhibiting such Reasons as seemed best to deny the Existence of Hermaphrodites in human Nature, to bring together the Opinions of several Authors, and make comparative Animadversions on them; by which Means, I hope, it will not be doubted, but that the Truth, which hitherto has been so clouded and obscured on this Head, may be said at least to begin to dawn, and by abler Hands may hereafter be brought to a clearer Light. To judge alone of any Performance is somewhat less difficult, than to perform and judge together; it is therefore that the World in general are better Judges than Performers, the Majority of whom will snarl at a Word or Sentence, as the Standers-by often do at a Gamester’s Manner of playing a Cast, they would have played themselves another Way, though perhaps not so well; and, therefore, however imperfect this little Work may be, as it means only to search for Truth, I hope the Reader will be so kind as to make some Allowance for it’s Imperfection; for if it should meet with Censure, that can amount to no more than a Condemnation of some particular Thing, in a Work which in general is, at least, well intended. THE INTRODUCTION _Containing some historical Observations on Laws, and other Occurrences concerning Hermaphrodites._ An indolent Person is always the most credulous of Novelty, at the same Time that his Supineness hinders him from examining into the Truth of any Rumour whatsoever. And this Kind of Passion is of the meanest Class, not only as it argues some Contempt or Neglect of Truth, but also as it is productive of a very great Evil, in setting a Limit or Bar to the Progress of Knowledge, and is therefore a vast Disadvantage to Society in general; from such a one as this, not the least publick Good, no more than private Benefit to himself, can flow; and the Man who has not a Desire to cultivate that innate Curiosity, which is every one’s Property, is unmindful of one of the greatest Duties incumbent on him; but when it is duly and honourably modified, and employed in the Search of useful Affairs only, it qualifies him for social Life, and renders him capable of being of Service in his Generation. Though one may be informed of a Matter which in itself is really Fact, yet if an Absurdity should arise in the Narration, it would be laudable to enquire whether it is to be ascribed to the Relater or to the Thing told; but as there is nothing which, when true, can admit of any Absurdity, there is therefore the greater Right to be discontented with what is not easily understood; and it would even amount to a Crime to neglect taking Notice of such Accounts, especially if any Thing monstrous or improbable is blended with them. Shall we, for Example, sit down with some Authors, and say, that _Hares_[2] are always of both Sexes; that the _Rhinoceros_[3] is always Male; that the _Vulture_[4] is always Female; that of all Animals[5], Goats, Sheep, Horses, Men, and Hares, are most liable to become Hermaphrodites? and shall we go on to copy or quote them in a Strain of Approbation? no; rather let us examine them thoroughly, lest by assenting to any Part of them, that does not square with Nature and Reason, we shall find our Judgments very deservedly arraigned, and the sagacious Part of the World much displeased. The constant Application of some great Men, (with whom this Island formerly has been, and is, at present, blessed) to the Study of Physical Affairs, is a glorious Example to encourage all younger Students to imitate their Steps, in the Pursuit of natural Knowledge, and, consequently, the publick Good, according to the different Turns of Mind, and those Studies that most delight them. Would such attain to a true Notion of the Animal Structure? let the Labours and Example of those great Anatomists _Douglas_[6], _Cheselden_[7], _Nichols_[8], and _Nesbit_[9], be their Guides. Would their Curiosity expand itself in the general Field of Natural History? Sir _Hans Sloane_ shews of this to form inimitable Scenes. Or would they endeavour to bring Physiological Learning into a clear Light by Dint of mechanical Reasoning, the celebrated _Mead_[10] and learned _Stuart_[11], with many others of our most honourable College, point out the way: would they, in fine, dive into mathematical Streams, the certain Directors to Truth, how many Examples of this Sort, as well as of those already mentioned, can our _Royal Society_, the most famous in the learned World, produce. All these are the Stars directing to the Haven of Science here, whom, if observed with Attention, it is no wonder if their Followers emulate to overturn Errors, and undeceive the Crowd that is hurried along through Mazes and Labyrinths of Misrepresentations, to hunt out the Truth, which is often very intricately environed round with dark Veils of Ignorance or Superstition. Such were the Motives and Considerations that prompted me to endeavour to wrest, from the Jaws of Scandal and Reproach, poor human Nature, which has, from Time to Time, suffered great Disgrace, and many of whose innocent Children have been punished, and even put to Death, for having been reputed Hermaphrodites; Ignorance of the Fabrick of the Body has been the first great Occasion of those Evils, destroying Evils, which exist not only amongst the most ignorant _Americans_, but also amongst the Litterati themselves in other Parts of the World. What, but Ignorance or Superstition, could perswade Men to imagine, that poor human Creatures (which were only distorted in some particular Part, or had any thing unusual appearing about them, from some morbid Cause affecting them, either in the Uterus, or after their Births) were Prodigies or Monsters in Nature? What, but Ignorance and Superstition, could urge Men to make Laws for their Destruction or Exclusion from the common Benefits of Life? in fine, what, but these very Causes, could make several harsh Laws continue still in Force against them in many Places, which suppose those Women that happen to be _Macroclitorideæ_, to be capable of exercising the Functions of either Sex, with regard to Generation; and, further, restrain them under severe Penalties to stick to that Sex only which they should choose? as if poor Women could exercise the Part of any other Sex but their own. The _Romans_, soon after the Foundation of their City, had Laws made against their _Androgyni_ remarkably severe; for whensoever a Child was reputed one of these, his Sentence was to be shut up in a Chest alive, and thrown into the Sea[12], which was as often put in Execution as any of these unfortunate Children were discovered. The Inhabitants about the Gulph of _Florida_[13] hold them also in great Contempt, believing them to be something so evil as not to deserve the Comforts of Life; and though they do not destroy them yet they deal as badly by them, for when they go to make War, as many of these supposed Hermaphrodites as can be found are obliged to carry their Provisions; they are also compelled to bear the Dead, and those sick of malignant Diseases, to proper Places, and attend them under very rigorous Circumstances. Nothing is more certain, than that the Causes above-mentioned have had no small Share in the propagating a Belief among the People of their Existence; and this appears by a Custom, that long prevailed amongst the _Pagans_ in _Italy_, who, upon the Birth of such Children, as were thought Hermaphrodites, always consulted their Religious and Wise-Men[14] what to do with them. A remarkable Instance of this Kind happened in a Town in _Campania_ in _Italy_, called _Frusino_, where a Child being born of a monstrous Size, and another at _Sinuessa_ whose Sex was doubtful, insomuch, that they could neither judge it Male nor Female, it was laid before the Magistrates, who immediately sent for some of the _Aurispices_, out of _Hetruria_, and they pronounced it, ‘_Fædum ac turpe prodigium_[15],’ whereupon it was thrown into the Sea according to the aforesaid Law. But this was not enough, for as by the Superstition of these Soothsayers and the _Pontifices_, such Children were thought to portend some Evil, there was a Ceremony that always succeeded their Destruction, which was performed by twenty-seven Virgins, who marched in Procession, singing about the City, and offered Sacrifices to _Juno_, to avert the Evil which they imagined was boded by the Child’s Birth. This happened many Times afterwards in _Italy_; and even the Christian Emperor _Constantine_, according to _Eusebius_[16], made Laws against them; for about this Time the River _Nile_ not flowing so much over the Lands as usual, the Blame was laid to their _Androgyni_ who worshipped and bathed in it amongst the People; whereupon the Law made against them was, that they should be looked upon as a spurious Breed, and destroyed[17]. ‘When the People of _Egypt_, and particularly those of _Alexandria_, worshipped the River (_Nile_), a Law was issued out against certain Men of an effeminate Nature, who worshipped among them; whereby all those commonly accounted Androgyni were to be destroyed, as an uncertain and spurious Race, nor was it permitted even to look on those that had such lascivious Disorders.’ Some time after the Law was made, the River began to flow freely, and swelled again over the Banks, as before. The Superstition of the Inhabitants was gratified, who, no doubt, owed the Restoration of the Waters to the cruel Law made against those miserable human Creatures. In order more clearly to illustrate under what Restrictions such, as were reputed Hermaphrodites, lay, touching the _Jewish_, as well as the Canon and Civil, Laws of later Date, I have taken from _Casper Bauhinus_[18] as many Tracts as he has collected, in his own Words as follows; whereby the Reader will be the better informed, how much these erroneous Notions concerning them prevailed from the beginning. _Of the ~Jewish~ Laws concerning Hermaphrodites_[19]. ‘In the _Hebrew_ Law there is often mention made of Hermaphrodites, although they were not very sollicitous about the Causes of their confused Natures. The Word Androgynus was very familiar amongst them, which, they say, signifies one having the Parts of Generation of both Sexes, one of which, however, they allow to be more luxuriant than the other. Hence arise some Disputes amongst them concerning the Laws they are subject to, which I have translated from the _Talmud_ in the following Words. ‘Androgyni are in their Natures to be esteemed partly as Men, partly as Women; partly as both Man and Woman; and partly as neither Man nor Woman, but as they appear in their proper Persons. I. ‘They are like Men in five Respects according to the Law of the Book of _Moses_: 1. By polluting whatsoever Man or other Thing which they touch, or that touches them, whensoever they have emitted their Semen; as Men pollute every Thing in such Cases, according to that Law: 2. They are obliged to marry their Brother’s Widows, not having Children, as Men are: 3. They are to go dress’d, from Head to Foot, after the Manner of Men, and to shave their Heads as Men, not as Women, for Intemperance Sake: 4. They are permitted to marry Women, as other Men do, and not to marry Men: 5. They are obliged to observe all the Precepts of the Law of _Moses_, as _Jewish_ Men are, but not as Women, who are not subject to all, because of those Things which their different Seasons require.’ II. ‘They are further likened to Women in seven Respects according to the Law of _Moses_: 1. By polluting every Man, and all Things they shall touch or are touched by, in the Time of their Menses: 2. Because it is not lawful for them to converse with Men alone in any private Place: 3. Because they may shave their Heads in a circular Manner as Women; and, besides, may spread out their Beards, which the Law of _Moses_ forbids to Men: 4. Because they are permitted to walk among the Dead as Women, which is forbidden to Men: 5. Because they cannot bear witness, as Women cannot: 6. Because, as Women, they are forbidden all unlawful Copulation: 7. Because, as Women, it is unlawful for them to marry a Priest of the Seed of _Aaron_, whereby they are vitiated. III. ‘They are to be esteemed as Men and Women in six Respects: 1. If they are assaulted by any Person, the Matter is to be agreed on according to the utmost of the Damage: 2. If they are inadvertently killed by any, the Person is to retire into one of the privileged Places, ordered for Security in such Cases, there to remain until the Death of the High-Priest, as if he had killed a Man or Woman, according to the Law of _Moses_; but if wilfully murdered, the Murderer ought to die as for murdering a Man or Woman: 3. When a Woman brings forth an Androgynus, she ought to be accounted unclean seven Days, as for a Male Child; again, other seven Days for a Female Child, that is, the Days of Uncleanness and Purification ought to be numbered as for the bringing forth of a Son and Daughter, according to the Law of _Moses_: 4. An Androgynus, if of a sacerdotal Race, is a Partaker of Sacrifices like other Men that are so, according to the Law of _Moses_: 5. They have share of both paternal and maternal Inheritances, and also in such other Inheritances as they may claim by Law as a Man and Woman: 6. When any Androgyni have a Desire to forsake worldly Affairs, it ought to be well attested, and they become _Nazarites_ by their Vow. IV. ‘They are finally, in three other Respects, to be treated as neither Men nor Women, but as a Person proper to itself, having a Right to neither Sex in particular: 1. Though an Androgynus should strike or calumniate another, he is not obliged to make any Satisfaction according to the Law of _Moses_ that regards Men or Women, but as a singular Person ought to make Reparation according to the Sentence and Agreement of proper Judges; 2. If any Androgyni shall declare their Vows to the Lord, according to the Estimation of their Persons, and shall dedicate such Estimation or Value to the Temple of God, if it is not made according to _Moses_’s express Law as of Men and Women, let it be done according to the Judgment of a Priest, regarding their particular Persons, or as it can be best agreed on by such as preside in the Temple of God: 3. But if any should declare of themselves their Desire of being devoted to God, separated from worldly Things, or bind themselves by the Vow of a _Nazarite_, then if such Persons are neither Man nor Woman, their own Words shall be of no effect, nor ought they to be devoted to God; these are from the Talmud of the _Jews_. ‘The Rabbi _Meir_ says, an Androgynus is a Creature of a particular Kind in itself; nor were some wise Men willing to determine whether they are Men or Women; but _Obthurata_’s Opinion is otherwise, who says they are sometimes Men, sometimes Women, according as the Appearance is of the Parts of either Sex.’ _Of the Canon and Civil Laws concerning Hermaphrodites_[20]. ‘Having recounted some Laws and Privileges of the _Jews_ concerning Hermaphrodites, we are now to propose certain Questions, taken from the Canon and Civil Laws, referring those who would know more, to the Writings of the Authors from whom we have gathered them, _&c._’ _Quest._ I. ‘Whether a Man’s or Woman’s Name should be given to an Hermaphrodite at it’s Baptism? _Ans._ If there seems to be more of a Male Nature than the other, a Man’s Name; otherwise, that of a Female; but if it be doubtful, it lies at the Discretion of him who gives the Name. _Q._ II. ‘How often should an Hermaphrodite confess? _Ans._ Once a Year as a Man or Woman. _Q._ III. ‘Can an Hermaphrodite contract Marriage? _Ans._ It is granted according to the Predominancy of Sex, which ought to be regarded; but if the Sexes seem equal, the Choice is left to the Hermaphrodite. _Q._ IV. ‘Are Hermaphrodites comprehended in the Statutes requiring Consent of Friends upon contracting with Women? _Ans._ The Statute concerns not a mixed Person. _Q._ V. ‘Can an Hermaphrodite be a Witness? _Ans._ No; except in Cases wherein a Woman may. _Q._ VI. ‘Can an Hermaphrodite be a Witness to a Testament or Last Will? _Ans._ The predominating Sex will shew that, _viz._ if more potent in the Male Sex he may; if the Sexes are equal, or more Female, not, _&c._ _Q._ VII. ‘Whether an Hermaphrodite ought to stand in Judgment as a Man or Woman? _Ans._ An Oath should first be taken which Member is predominant, and the Person admitted accordingly; but if both are equally powerful, not to be admitted, according to the holy Church. _Q._ VIII. ‘Can an Hermaphrodite be promoted to holy Orders? _Ans._ An Hermaphrodite is driven from this Promotion because of Deformity or Monstrosity; but if more masculine than feminine, the Character may be conferred, though not Ordination, nor a Power of Administration. _Q._ IX. ‘Can an Hermaphrodite be Rector of a University? _Ans._ No; for there cannot be a married Clergyman, nor an Hermaphrodite, nor one less than twenty Years of Age. _Q._ X. ‘Can an Hermaphrodite be a Judge? _Ans._ An Hermaphrodite is reckoned among the Infamous, to whom the Gates of Dignity ought not to be open. _Q._ XI. ‘Can an Hermaphrodite be an Advocate? _Ans._ No, being infamous. _Q._ XII. ‘Can an Hermaphrodite be an Arbitrator? _Ans._ Yes, whether there appears more of the Male, or more of the Female Sex, or an Equality of both, _&c._ _Q._ XIII. ‘Can an Hermaphrodite fall under Penalties? _Ans._ If the Male Sex is predominant, he comes in as a Male. Another Author says, Male or Female Sex predominating, when occupying the Possession of another by Force, they are under the Law. Another: There is no need of disputing the Sex in this Case. _Q._ XIV. ‘Can Hermaphrodites pretend to be ignorant of their Constitutions? _Q._ XV. ‘Can Hermaphrodites succeed in Copyholds? _Ans._ In the Affirmative, if more Male than Female. Others: though that Sex does not predominate by the Appearance of the Pudenda, yet if they seem, in other Works of Manhood, as Agility of Body, to be equal to Men, they may succeed in such Inheritance; for that they who resemble perfect Persons ought not to be accounted altogether imperfect, because that Imperfection is concealed, but Perfection is evident and manifest, therefore to be chosen. Others: that the Laws granting Feudes to the descending Males, do not include Hermaphrodites. Another: If, from Custom, Women cannot succeed in a Feude or Copyhold, so an Hermaphrodite cannot; which is to be understood of those only in whom the female Sex is most apparent; where such Hermaphrodites, who are more Female, are compared to Females, and those more masculine to Men, therefore the Law is to be determined accordingly. _Q._ XVI. ‘How should an Hermaphrodite serve in any Office? _Ans._ In whatsoever Manner they best can themselves, and not by a Substitute, _&c._’ _Q._ XVII. ‘Can Hermaphrodites chuse, on their Parts, any one of their Brothers to succeed them? _Ans._ They may gratis, but not for Gratification, _&c._ ‘Whosoever would know more of the Laws concerning Hermaphrodites, may consult the Doctors and Expounders of the Law; these being sufficient concerning them.’ We have not even in our own Kingdom been free from the same prejudiced Care, in providing Laws against them; for as we had borrowed many from other Nations, and added them to our own, so we find one among them concerning Hermaphrodites, mentioned by _Coke_[21] in his Commentary upon _Littleton_, where he speaks of them thus[22]: ‘Every Heir is either a Male, or Female, or an Hermaphrodite, that is, both Male and Female. And an Hermaphrodite, which is also called an Androgynus, shall be Heir, either as Male or Female, according to that Kind of the Sex which doth prevail, and accordingly ought to be baptized.’ Would not any one imagine that these supposed Androgyni, instead of being of the same Nature with us, (however morbid or deformed their Parts of Generation might be) were rather another Race of Animals _sui generis_, than what they really are? when a String of Laws, compiled with so much Accuracy, and in such a formal Manner, concerning them, has been exhibited and increased in all Ages; and is it not Matter of great surprize, to think that none had ever undertaken to convince the World of the Superstition and Vanity of such Laws? since those that were already in force, in all Nations, were as sufficient to bind a morbid Subject in all Cases, as a sound one; which alone is the Question here. Though the World was lead on to credit and countenance those Whims till _Cicero_’s Time, and supposing none were found able or willing to set People right in this Opinion before him; yet we may, with great Assurance, ask, why the Learned since him should neglect the Hint given by that wise Man in his Book _De Divinatione_, where we find him making a Banter of several Superstitions then in Vogue with the _Romans_; among which he does not forget to enumerate the _Androgyni_[23]. ‘_Quid cum Cumis Apollo sudavit, capuæ victoria? Quid ortus Androgyni? nonne fatale quoddam Monstrum fuit?_’ Sure this, as well as any other Matter, worth the Notice of that noble Author, ought well to bespeak the Attention and Consideration of the whole World after him. Several _Jewish_ Rabbins, and most of the _Hebrews_ before them, were of Opinion, that _Adam_ was first made an _Androgynus_[24], on the fore Part a Male, and behind a Female; that these were afterwards separated, and the female Part called _Eve_. This was their Manner of explaining those Passages of the Old Testament, ‘Male and Female created he them;’ and again, ‘Thou hast formed me behind and before:’ These Opinions gave Birth to many others afterwards, as well among the Pagan Philosophers, as among many Christian Divines; some of whom, in the Time of Pope _Innocent_ the Third were so far Followers of the Rabbins, that they thought the Sexes in _Adam_ would never have been divided if he had not sinned; which was granting that _Adam_ was created an Hermaphrodite, and that the two Sexes were taken asunder afterwards. Others[25] of these believed so firmly that Hermaphrodites existed, that they took Pains to confute the above Opinion, only fearing lest such should assume to themselves to have been the first human Creatures made, from the Words above-mentioned, ‘God created Man Male and Female, _&c._’ and consequently the most worthy. From all these Things we see how little it is to be wondered at, that the Majority of the World should be thus riveted in their Notions of Hermaphrodites, since it appears, that Doctors of the _Jewish_, _Pagan_, and Christian Churches have been Promoters of them from Time to Time, by Doubts and Sentiments in themselves so trivial, as not to deserve any Credit from an impartial and judicious Reader. Credulities of this Nature, though upon the most insignificant and ill-grounded Assertions, generally make great Progress in the Minds of Men and are sometimes so deeply rooted, that the Vicissitudes of many Ages have not been sufficient to open Mens Eyes, or make them sollicitous for the Truth. Of this Sort was the Notion of Witches in the World; for it is plain from Record, that many poor Women were condemned to the Flames or Gallows by the greatest Sages in the Law; and the Sentences against them were so arbitrary as never to be mitigated, but hurled them to Destruction without the least Regret or Pity from the Witnesses of such Barbarity; and yet how easy would it have been to discern (if Men gave themselves the Liberty to reflect a little upon the Nature of the Thing) that no Guilt, nor any such preternatural Knowledge as was said to center in them, could proceed from those ignorant simple People, that were always the Subjects of this Cruelty. Thus it often fared with our reputed Hermaphrodites, who have been banished, tormented, abused, and employed in such Offices as were in themselves severe; cut off from the common Privileges and Freedoms enjoyed by the Publick wheresoever they have been; yea, and put to Death in an inhuman and pityless Manner. But the Disgrace which hangs over human Nature, from Mens harbouring such strange Notions of one another, is almost as bad; and more especially so, when several who are ranked among Men of Science shall espouse these Chimeras, or at least confess a Doubt concerning the Thing: So that it is not to be wondered at, if the weak-minded and injudicious should be impressed with a Belief of Reports of this Kind, and thereby lose all Humanity towards such Objects; and no wonder modest Ears should be grated with the Stories of such Creatures, since they are more frequently exposed to vast Numbers of the indiscreet Part of the World, than to Men of Knowledge and Decency. Since this is the Case, and since Authors, of no little Account among the Learned, have taken great Pains to confirm the Certainty of the Existence of Hermaphrodites in human Nature, and, at the same Time, differ so much from each other concerning them; it could not but be very well worth while to attempt finding the Truth of what, I so much mistrusted, was asserted without any just Foundation, and what I could not but esteem a Scandal thrown upon the whole Race of Mankind; and therefore, upon seeing the Fœtus whose Description, with an Observation upon all female Fœtus’s, concludes the following Pages, I was the more encouraged to read upon and consider the Subject; and finding myself unable to reconcile the Accounts of Authors to Truth, and the Nature of Hermaphroditism to the Physiology of human Bodies, I was still the more eager to endeavour at being satisfactory to others as well as myself, about what has been so long a Riddle. The Arrival of the _Angolan_ Woman in Town encouraged this Undertaking, both from the Belief of the Vulgar concerning her, and the Sentiments of others, who would allow her no Sex but the Masculine; which rendered it not an unseasonable Time to make a further Progress in this Essay towards reducing the Matter to a Certainty, which (however deficient) I hope, will be in some Measure acceptable to all Lovers of Truth in Natural History. _BOOKS printed for_ J. WALTHOE. Dr FREIND’s History of PHYSICK, from the Time of _Galen_, to the Beginning of the Sixteenth Century; chiefly with regard to Practice. In a Discourse written to Dr _Mead_. The _Third Edition_, in 2 Vols. 8vo. R. WELSTED, M. D. _de Medicina Mentis_. _Commentarium Nosologicum Morbos Epidemicos & Aëris Variationes in Urbe ~Eboracensi~ per sedecim Annos grassantes complectens._ _Autore_ CLIFTONO WINTRINGHAM, M. D. An EXPERIMENTAL ENQUIRY on some Parts of the ANIMAL STRUCTURE. By CLIFTON WINTRINGHAM, jun. T. LUCRETIUS CARUS of the Nature of Things. Translated into English Verse by THOMAS CREECH, _M. A._ The Sixth Edition. Illustrated with Notes, making a complete System of the Epicurean Philosophy, 2 Vols. 8vo. A NEW METHOD OF IMPROVING Cold, Wet, and Barren LANDS, particularly Clayey Grounds. _This Treatise contains, 1. The best Methods of draining wet Lands, either arising from their Situation or Springs. 2. Directions for burning Turf, Mole-hills, and Clay, for the Improvement of such Lands. 3. The many Advantages that arise from boggy Grounds by turning them into Plantations, according to the Nature of the Soil, and Situation of the Place. 4. Directions for making of Fishponds and Ditches for feeding or breeding Fish, and carrying off the Water. 5. The Method of burning barren Land in North-Britain. 6. How to ascertain the Value of Hilly Grounds, a Thing extremely useful to Landlord and Tenant. 7. Directions for making Gardens in Clayey Grounds, and a certain Method of improving Fruit-Trees. The Whole illustrated with Eight Copper-Plates, exhibiting the Figures of the Instruments necessary for such Improvements._ Price sewed 2 _s._ and 6 _d._ Observations on the different _Strata_ of _Earths_ and _Minerals_. By JOHN STRACHEY, Esq; _F. R. S._ Price 1 _s._ A MECHANICAL and CRITICAL ENQUIRY Into the NATURE OF Hermaphrodites. CHAP. I. _Reasons against the Existence of an Hermaphrodital Nature in human Bodies._ An Hermaphrodite is an Animal, in which the two Sexes, Male and Female, ought to appear to be each distinct and perfect, as well with regard to the Structure proper to either, as to the Power of exercising the necessary Offices and Functions of those Parts. This Definition naturally arises from the very Term, and therefore, whatsoever is so accounted, and fails of answering these Characters in the most minute Particular, should be consider’d in another light, and indeed call’d by some other Name. It would be an Injury to Truth to deny the Existence of an Hermaphrodital Nature, to all the animal World in general; but however, I am inclin’d to believe it is only proper to some Reptiles, and but a few of these; for among the several Tribes of larger Animals, whether of the Air, Earth, or Waters, there seldom are any, of late Years, to whom this double Nature is ascribed, but those of the Human; with how little Truth or Reason, even to these, I hope to make appear hereafter. Whatever the Necessity might be for the Creation of certain of the Reptiles of this Nature, such as the Garden shell’d Snail, and the large Earth-worm, both of which are certainly so, which I can affirm from my own Knowledge, having often drawn both these asunder when in Coition, and observ’d them; as well as from so good Testimony, as Mr _Bradley_ in his Philosophical Account of the Works of Nature[26], where he has several curious Observations on these Animals, and a Figure of the Parts of Generation of a Snail, done as they appeared in a Microscope. As also from a Book intitled, _Spectacle de la Nature_, which is no less to be regarded than the former, both for Truth and Accuracy. I say, whatever may be the Cause of this, there does not appear in Reason the least occasion for it in larger Animals. As to the former, if we may attempt to guess at a Reason for their being thus created, it may perhaps not be amiss to surmise as follows, _viz._ We know these are very slow Creatures in their Motions, and consequently their Congress is the more seldom; and besides they are subject to so many destroying Accidents, that if the female Properties were but in one, it would hardly be sufficient to preserve their Species; hence it is that at the same Access they both beget, and bear in a reciprocal Manner. However, one Observation worthy of note is, that though they have a Capacity of both ways of engendering, it must be remark’d, that it is at the same Instant both are executed, and not successively or by Choice, being incapable of neglecting either to chuse the other. Besides, we find they are all so, through their whole Class; which to them is the same strict Law of Nature, that it is to other Animals to possess but a single Sex. Nor can this Law be ever violated in them, by any Means whatsoever, any more than that Law of Nature predominant in us should digress from what it always was, or be alter’d by any new Decree of the Divine Will, whose Decrees are already fix’d and unchangeable; our single Natures being sufficient to preserve the human Race, in a successive Series, and their double one being no more; which alone was the Purpose of such Formations in all animal Beings, and no other. But no such Restraints attend larger Animals, and therefore no such Nature is at all necessary in them; however, tho’ all others are limited to certain Seasons, as to their generative Capacities, it is very strange that no Appearance has ever been had of two Sexes in any one upon Dissection, (though many have been supposed of a double Nature) but the human; who have no limits set to their Powers of procreating, and who on all accounts seem to have the least need of any thing of the Kind. If it be objected that it happens not to human Nature through any Necessity, but only from a Lusus of Nature; I answer, that no such Lusus can happen, and it will be very evident, if we only reflect a little upon the Nature of Generation, which will be more amply treated of in another Place; however, one Principle will be sufficient to our Purpose here, which is, that the Rudiments or Parts of all Animals whatsoever are already form’d in the Ovum[27], and that nothing can be produced by the Males, but a Juice capable of giving Motion, Explication, and Extension to those Parts, and that since we know the common Standard of Nature in human Bodies is, that there should be but one Sex in one Body, it is impossible that there should be the least Imperfection in the Rudiments of any one of the Ova, since they were implanted in Females from the Beginning of Time, by the Almighty _Fiat_, and were under the Restriction of that Law, that every Day’s Experience confirms to us is certain; for if there was not so absolute a Law, with respect to the being of only one Sex in one Body, we might then, indeed, expect to find every Day many preposterous Digressions from our present Standard. That there are certain Limits set to the Things of Generation appears no where better than when Animals of different Species meet and copulate; the Animal that is the Product of such a Congress is in no wise capable of producing an Off-spring like itself, to this there is an absolute _ne plus ultra_, and why? Because, indeed, if such were capable of Generation, we should, by degrees, have a new set of Heterogenous Animals upon Earth. But it is plain, it never was the Design of the Almighty, since every Species of Animals are the same now that they ever were, and we must, from this Argument, expect no other while time subsists. And indeed, were we to have regard to the Notions of some of the Ancients concerning Generation, as, that the Male and Female Semina meeting form’d a Child of either Sex, according to the Predominance of the Strength or Quantity of either Semen, and if both were equal in Quantity and Quality, a Child of both Sexes was begotten, I say, were we to have regard to this, we might still be liable to be borne away by this Hypothesis, as Authors have been hitherto, which would inevitably seduce us to believe, that there are Hermaphrodites in human Nature. And therefore, whensoever the Parts of both Sexes are seen distinct in any Subject, they are not in the same, but in different Bodies preternaturally join’d, and coalesced together in the Uterus, by Compression, Heat, Inflammation, or some other such Accident; of this there lately was an Example in Town at _Charing-Cross_, which had the Heads separate, and the Sexes appearing considerable Distance from each other. But who, with the least Propriety, can call these an Hermaphrodite, each Body having it’s peculiar Sex, and being morbid in their Conjunction. The Notions that sprung up in the World concerning this Matter were (no doubt) first taken from Appearances that sometimes have happen’d of an extraordinary Elongation in the Clitorides of Females; the first Idea conceiv’d from thence must have been that of a Penis, and the Appearance of a Vulva join’d to it raised an Opinion of both Sexes in the same Body; hence proceeded the Invention of a proper Name for the surprising Unity of both Sexes; and hence, the Fictions of Poets, which the Learned are well acquainted with. It will not be very difficult to account in some Measure, for the rise of such erroneous Imaginations, if we only consider how ignorant the World was in former Ages of the animal Structure, and even of those that understood ought of it, how few there were, who (from the Obscurity of the Clitoris in Females in a natural State) knew that any such Part existed: It is therefore not much to be wonder’d at, that at the first Sight of a large Clitoris, divers odd Conjectures should arise, and supply the Fancy of those unskill’d in a due Knowledge of the Part, with Matter sufficient for the Erection of new Doctrine. An Opinion of any kind, when once on foot, is a Law to Posterity, till repealed by the Doubts and Scrutinies of the Learned and Curious. Doubt is the only Path to Truth; for by this we examine, search, and discern Truth from Error; natural History affords Examples enough of Falshoods copy’d and handed down from Age to Age, through the whole Class of Writers, who never doubted each other, and consequently were never able to know the Truth of Things, upon which many Volumes have been wrote; and it is matter of no small surprise, that Authors never were able to take the least hint from the Practice of the People of some of the _Asiatick_, as well as the _African_ Nations, concerning these large Clitorides; for as in both these Parts of the World, the Women have them most commonly very long, and the People knowing that the Length of them produces two Evils, _viz._ the hindering the Coitus, and Womens abuse of them with each other, wisely cut or burn them off while Girls are young, and at the same time never entertain the least Notion of the Existence of any other Nature besides the Female in those Subjects who are thus depriv’d of that useless Part. This Knowledge is not confin’d to Men of Science alone amongst the _Egyptians_ and _Ethiopians_, nor indeed amongst the _Asiaticks_; for every Parent knows when the Child has this part longer than ordinary, and performs the Operation at a proper Time; which De Graaff seems very much to approve[28]: ‘_And the Excision of this Part is as necessary as it is decent to those Eastern People._’—Which was also perform’d and taught, by several of the ancient Physicians[29], as particularly as any other Operation whatsoever; and yet even in our own Days, we find some Anatomists of Repute confessing a double Nature, and a Mixture of Sexes in the same Body, and others calling the Labia pudendi a divided Scrotum, and fancying Urine and Semen to pass thro’ the Clitoris. But it is observable, that where there is a perfect Penis and Scrotum found in a Child, there is never the least Sign of any Part proper to a Female annexed to it; but that, on the contrary, whatsoever Subject is said to be an Hermaphrodite has the _Feminine_ Parts in Perfection, and no Penis nor Scrotum, nor, according to _De Graaf_’s Dissection, any Organ serving to their Nutrition, Action, Accretion, or any other Function, but only the Clitoris (common to all Women) somewhat larger than Ordinary, which will fully appear when we come to speak of him. There are many Authors who have given Histories of Women that have been detected in the Abuse of such large Clitorides, calling them Τριβας, Confricatrices, and the like, the Recital of one from _Tulpius_[30] may not be amiss, who after relating some Passages transacted by one of these and a certain Widow, makes this Reflection, ‘Though the Clitoris for the most Part lies hid, yet several have it so large, that they are thought by the Ignorant to be transformed into Men; but that this (whose History he writes) was in all respects a perfect Woman, having only the Clitoris half a Finger’s Length.’ And since this worthy Author has given us this Story so suitable to our present Purpose, it will not be unseasonable in this Place, to take some Notice of a Memoir in the Transactions of the _Royal Society_, presented by one Dr _Thomas Allen_[31], the Subject of which he calls an uncommon Lusus, and says, ‘This Hermaphrodite is not to be reckon’d amongst the Τριβαδες of the _Greeks_, nor to be equal’d by any Description yet extant.’ These Τριβαδες were no more than Women with Clitorides larger than ordinary. Such of them as are so may be capable, perhaps, of that Action from whence the Name arose, whether they perform it or not; and by considering the Sequel of this History, we shall find the Subject he describes to be no other than a very Woman, such as _Tulpius_ has given the History of. He says, ‘at six Years of Age, the Child playing and wrestling with her fellow Children, there appeared two Tumours like Hernias, but they proved Testicles, differing from those of a Man only in this, that each had its own distinct Scrotum; but in such a Manner, that the Production of both form’d the Labia of the Vulva.’ Our Author, after arming our Imaginations with an Expectation of something very extraordinary proceeds to describe a true Female Child, only he would allow her a Pair of Testes, but instantly owns the Scrota of these form’d the Labia. It would have been altogether as well to have said at once, the Labia were thicker than ordinary, for he could not positively say they were Testes without the Dissection of them, which was out of his Power, since we find him tracing her History to a more advanced Age. But further, he proceeds thus: ‘In the Sinus, or Fissura Magna, the Nymphæ and Carunculæ myrtiformes appear’d entire, and half the Vulva was cover’d with a thin Membrane from the Perinæum; and there was no Appearance of a Clitoris; the Uterus and its Neck were exactly like those of a Female.’ What has this Author described here, but a perfect Female? As to the Nymphæ’s being entire, they are never known to be otherwise, except a Dilaceration of them happens by some violence; the Carunculæ are indeed liable upon slight Occasions to be broken, however in so young a Subject it would be very strange to find them so, therefore there is nothing extraordinary in this Part of his Description; but if he should mean by the Word _entire_, that these two Parts were conjoin’d together, his Notion of them seems somewhat imperfect, for the Nymphæ have their rise at the Clitoris, and are lost on each Side before they reach the Orifice of the Vagina; whereas the Carunculæ Myrtiformes are within the same, out of any Manner of Communication with the former. The thin Membrane[32] from the Perinæum that cover’d half the Orificium Vaginæ is not an uncommon case; for in several this Skin runs over the whole Part, and therefore this, no more than any Part of the above Description, is to be counted proper to an Hermaphrodite. Again, there was no Appearance of a Clitoris, and the Uterus and its Neck were exactly like those of a Female. Though the Clitoris might have been then but small, yet that she had it is most certain, for in some they grow surprisingly in a little Time, and what our Author calls a Penis afterwards is nothing else; but how he could find out that the Uterus and Cervix were like others is a Riddle, since every Anatomist knows how remote these are from Sight in a living Subject. At last he says, ‘she pass’d for a Woman till the thirteenth Year,——when kneading of Dough, all of a sudden, a Penis broke forth, four Inches long in an Erection, situated as in a Man, with a Glans and Præputium fasten’d to the Frænum, but the Glans being imperforated——deny’d egress to the Semen, wherefore it made its way thro’ the Pudendum Muliebre, possibly in a refluent Manner.’ It is no wonder she should pass for a Woman, who, according to our Author, had all the Feminine Parts to such Perfection; and though the Accretion and Protrusion of the Clitoris was never so sudden, yet there is not the least Reason to ascribe to her a virile Nature, because the Female Parts remain’d as perfect as before, without the lead Metamorphosis, and she had her Menses regularly from her sixteenth during the two following Years, at which time, says our Author they ceased, and she began to have a Beard, Hair on her Body, Voice, Breasts, Thorax, Ischia, and many other things like those of a Man. However, this sudden Growth of the Clitoris is not to be credited, for those who shew a Child of this Nature will tell any Lye to render the Thing more surprising, as, for example, who by reading the Bill of the little _French_ Girl, could imagine any other than that, in an erect Posture, she was only 16 Inches high? Whereas when her Limbs came to be view’d, the Spectators found themselves mistaken, for the Person never set forth in his Bill that she sat when she was measured, or that her Limbs were folded over each other. Hence it appears that the Narrations of these kind of Things are always false, and the Subjects never answer the Character or Description of them given by the Owners. The Doctor here believes the Man’s Description of this Subject, and accordingly gives the Memoir to the _Royal Society_; but the Owner makes a Change in his Story of the Girl when he carries her to _Utrecht_, where he shew’d her in 1668, at which time she was about one or two and twenty Years old, being born in _February_ 1647, according to our Author, and in that Town she had her Menses regularly, which the Doctor says stopp’d at her eighteenth Year; but the Variation made in the History of her will farther appear, when we come to take notice of _Diemerbroeck_ who saw her at that Town in _Holland_, and gives a History of her in his Book of Anatomy. The Doctor calls the Extremities of the Nymphæ a Frænum, which he says fasten’d the Glans and Præputium; for in all Females of this kind, the Nymphæ arise in an acute Angle on the under side of the End of the Clitoris, which will appear in our Description hereafter, but owns ‘the Glans was imperforated, wherefore the Semen made its way through the Pudendum Muliebre;’ it would have been better and more judicious, not to have said a Word of the Semen’s being deny’d a Passage thro’ the Glans, and so going back in a refluent Manner the other Way, except he had a Mind to demonstrate by what Road it had such a refluent Passage. The inconsistencies that appear thro’ this whole Narration from first to last, should promise no great Credit, for it is entirely taken from the Owner of the Girl, and securely presented to the _Royal Society_, without the Author’s considering that no one Part of his History can be reconciled to the known Laws of the Structure of the human Body. I should not omit in fine, to take notice of one Word more, ‘That at the Sight of a Woman her Penis was erected, and became flacid at the Sight of a Man;’ from this I can conceive no other, than that she had more desire to the Woman than the Man; and yet a little after he says, she cast her Eyes upon a handsome Man and fell in Love with him. But as I have said above, _Diemerbroeck_ will in his turn illustrate more particularly how little credit ought to be given to the Tales of Shew-men, by the Learned. It has been often argued by Authors, that these Confricatrices are more inclined to desire the Access of Women than of Men, and being willing to favour the Opinion of both Sexes being found in one Person, draw from that Argument this Conclusion, that therefore there must be as much of a Masculine nature, as of a Female in them. To this it is answer’d: That they do not desire Women more than Men, from a mere natural Inclination, but because by a Gratification of this Nature there is not so much danger of being expos’d; therefore a Congress like this is the more eagerly sought after, and agreed on by two Females so inclin’d, since by an over long Clitoris in one, both find their accounts answer’d, without fear of that Accident, that is the necessary Consequence of dealing with Men; for that Part being, as all allow, the Seat of great Titulation, it is no wonder it should be stimulated by being embraced in the Vagina, nor that the Receiver should also be effected by such Frication, as well as by a Penis Virilis; thus I hope it appears plainly that this Conclusion is ill grounded. Another Argument made use of is: that those reputed Hermaphrodites have Beards like Men and Hair on some of their Breasts. This can make but very little towards proving a Masculine Nature in them; for supposing some of these Fricatrices to have Hair _&c._ as above, yet there are many Women with Hair between their Breasts and on their Chins, who deserve no such Repute; one I have often seen whose Arms to the Fingers Ends were covered with long black Hair, having a Beard also on her Chin, who was the Wife of a Man of Fortune by whom she had eight or nine Children. I have also, at the _Hôtel de Dieu_ at _Paris_, seen a Body open’d that was hairy in the same Manner, without any Sign of a Masculine Nature whatsoever. Again, several Women advanced in Years have great Quantities of Hair on the Chin, but the Number of these as well as the former, among Women, are but few; and those that are so ought no more to have any such Character ascribed to them, on that account, than that many Men who want Beards should be said to partake of a Feminine Nature, and want the Power of exercising the Functions of a Man; but daily Experience shews us these are as prolifick, and produce as many Signs of Virility, as any others whatsoever. There have been many Reports of Persons who, in a certain Process of Time, have been said to change their Sex; and many[33] Authors have handed such Accounts with great Confidence to the rest of Mankind, which, like a Contagion, has infected them into a Belief of the Matter; a brief View of the Source of such Rumours may be of Use here, to shew how credulous some have been in receiving Stories of strange Things, and how indolent and supine in finding out the Truth of such. 1. The First Origin or Reason of this Notion then appears in the Account of Dr _Allen_’s Hermaphrodite, _viz._ that the Girl was changed into a young Man; which is so clearly laid down already in his Story, that here needs no Repetition. 2. The Second appears to be taken from actual Male Children, who were sometimes mistaken for Females at their Birth, only from the Penis’s being as it were shrunk into a Chink, and the Testes also not yet fallen into the Scrotum, which remaining so for some time till (a proper Sense of the Sex beginning to dawn in them) the Parts begin to swell, and be protruded and extended towards a natural Size. Thus several Children have been, through Ignorance, baptized, habited, and reputed Maidens; and, upon the aforesaid Protrusion of the Parts, said to change their Sex and be transformed into Men; which many Writers have taken Pains to maintain. Of this Nature, was one seen by _Casp. Bauh._[34], and _Fæl. Plat_, who was called _Anne_, about 23 Years old, and was hir’d as a Maid Servant to a Countryman; The Master observ’d, that this Servant, upon some Occasions, was in greater favour with his Wife, than himself; and therefore brought the Affair before a Magistrate, who committed the Examination of the Person to these two Physicians, the former of whom gives the following Account of the Matter[35]: ‘He was tall and thin, having a Masculine Voice, a long Head of Hair, and only some softish Hairs on his Chin, (for he us’d to pluck his Beard with a Tweezer as fast it grew) he had no Breasts, but was hairy about the Pubis, and had a long Penis, and the Præputium drawn back and well worn; he had no Scrotum nor Testes that were visible: Under the Penis, in the Perinæum, where Lithotomy is commonly perform’d, there was a kind of Chink, about half a Finger’s Joint deep, _&c._ from all which we judg’d him a Man rather than a Woman. Being ask’d concerning his venereal Performances, he confess’d, that he had cohabited with several Whores, with a seminal Ejection and much Pleasure; and further, that whenever he had to do with any, or ever had an Erection of his Penis, a Testicle swell’d in his Right-Groin, (for sometimes the Testes do not descend into the Scrotum, but remain in the Inguina) which we perceiv’d by touching, but that on the left Side, nothing was to be perceiv’d neither during the Coitus nor otherwise; nor did any thing ever flow from the aforesaid Rima or Chink.’ Here was therefore a perfect Man, mistaken for a Female Child at the Birth, on account of the invisibility of the Testes, and the Appearance of that superficial Chink in the Perinæum[36]. 3. A Third Reason for such Reports has been taken from Boys having been concealed in Female Dresses, for some political or family Occasions, and so continu’d under that Acceptation, till either Matters came to such a Crisis as render’d their Case less dangerous, or till Beards and other Signs of Virility have occasion’d a Declaration of their true Sex, and a Change of Habit. The Vulgar now make a Rumour of a miraculous Change in Children, whom they before accepted of as Females; the Report takes wing, and is catch’d by several who commit the Story superstitiously to Posterity, without any Manner of Enquiry into the Nature of the Thing. A Case of this Nature is cited by _Diemerbroeck_, which happen’d in the Time of _Ferdinand_ I, King of _Naples_; it was of two Children, who were call’d _Carola_ and _Francisca_, and were reported to have changed their Sexes upon the Appearance of Beards growing on them, which their Mother gave out was miraculously done, upon which she changed their Habits for those of Men. The Story reached _Fulgosus_’s Ears, and he wrote it confidently and securely, and yet our Author _Diemerbroeck_ discredits it very much, since the Rumour proceeded from the Mother and no other Witness, with whom the rational Part of the World must concur. _Johan. Bauhin._ furnishes _Skenckius_[37] with a History of a young Man, who was thought to be a Girl, by all his Acquaintance; because he sat in the Manner of Women to make Water, which was occasion’d by the Glans Penis’s being imperforated, and having a Passage for Urine under the Penis; he lay with Women and was dress’d and employ’d as one all his Life; and dying of a Pestilential Disease, was, by order of a Magistrate, open’d, and found to be a perfect Man in all respects, without any Part proper to the other Sex in the least. In all probability, if he had been detected, when alive, he would have pretended a miraculous Change of Sex as did the Mother of the above _Carola_ and _Francisca_. There[38] was an Opinion amongst the _Greek_ and _Arabian_ Physicians, concerning a great Analogy between the Male and Female Genitals as to their Structure, who strenuously assert, that these differ in nothing but their Situation, that is, they compare the Cervix and Vagina Uteri to the Penis, and the Fundus to the Scrotum, only they are inverted or rather not protruded, and that which hinders their Protrusion in Women, according to these Authors, is the want of Heat and sufficient force of Nature. It would be a Digression from our present Purpose, if we should enter upon a comparative View of the Parts of Generation of both Sexes, and endeavour to confute those Chimeras, and therefore the Use that is at present necessary to be made of this Opinion, is only to shew that this was another Origin from whence these Reports of such Metamorphoses have sprung and been encouraged, as well as any of those others already taken notice of. For admitting that Hypothesis, _viz._ that every Woman is a Man, if she had but heat of Temperament and Strength sufficient to drive the inside of the Uterus, _&c._ outward, and that that Inversion should form a Penis and Scrotum, which was the general Notion amongst some of the Learned a long time after _Galen_; I say, admitting this was now the reigning Notion, we should upon the least Appearance of any thing strange in the Parts of Generation, be as ready still to acquiesce to any Rumour of the Change of Sex, _&c._ as ever, having so easy a Manner of accounting for it, as the _Calor eximius & Naturæ Vis_, which was the fashionable Cause to which Changes of this Nature were always ascribed, both by the _Greeks_ and _Arabians_. It will not be improper here to observe, that all these Changes in the Sex were most commonly said to be made from Women to Men; and I never could hear any Account whatsoever of Mens being chang’d into Women, but two or three, one of which happened here in _London_; the Story will not only be of use to our Purpose, but a merry one, and therefore take it briefly as follows: At a great Tavern in _London_[39], there lived, some few Years ago, two Drawers who were a considerable Time Servants in the House, and always lay together; one of them gets the other with Child, who was with a great deal of Shame and Confusion turn’d away, and oblig’d then to put on Womens Clothes. The Rumour of the Drawer’s being chang’d into a Woman made a great Noise all over the Neighbourhood, and very likely would have been recorded for Truth, if it had happen’d in an Age little earlier. Here was a poor Girl whose Parents ignorantly believing she was a Boy from the Length of the Clitoris, dress’d her up, and employ’d her as such in the Business of Life; she no doubt believ’d herself so, until she was better instructed by her Fellow-Servant; and here is Matter and Foundation, altogether as probable and sufficient for Poets or Historians to build upon, as any heretofore taken notice of; and, in fine, hence it plainly appears, that it is with equal right, that human Nature may be said to be capable of admitting of two Natures Male and Female, in one Body, and of changing from one Sex to the other. Another is told by[40] _Caspar Bauhin_. of a Child who was baptized as a Male, and was brought up a Taylor by Trade, went afterwards into the Army, and serv’d as a Soldier both in _Hungary_ and _Flanders_, marry’d a Wife, and liv’d seven Years with her, at the End of which, our Soldier one Night rose from the Wife, complaining of great pains in the Belly, and in half an Hour, was delivered of a Daughter. When the Story came before the Magistrates, an Examination was made, and the poor Female Soldier confess’d herself of both Sexes, and that a _Spaniard_ had cohabited with her once (only) in _Flanders_, by which she proved with Child; that the Wife had concealed her want of what might be expected from a Husband, with whom she never was able to act in any wise, during their (seven Years) living together. The Author introduces this Story in the following Words[41]. ‘As the following History is of no small Importance in explaining the Nature of Hermaphrodites, I have translated it thus from the _German_ Language.’ From which Words it appears, that he had a very just Notion concerning them, and was so far from making such things Prodigies, being well versed in the Knowledge of the Animal Structure, that he counts the History of this, and another Soldier whom _Keckermannus_ gives an account of, sufficiently explicatory of the Nature of Hermaphrodites in general. The Parents of these could have no other Motive for thinking these Creatures Boys, than the Length of the Clitoris; which is plain from their bearing Children when they came to Age; and if any thing of a Masculine Nature was in the Soldier, it could surely in seven Years Acquaintance have been exerted to the Gratification of a Wife, or would have produced some other Effects very different from that of being got with Child. CHAP. II. _An historical and critical Account of the Causes of Hermaphrodites._ If Hermaphrodites actually existed, sure there might have been before now some probable Conjectures made to shew the Reasons, or Necessity of such Beings upon Earth, since so many Authors have been busy’d about them from the Beginning of the World. But there appears throughout their several Opinions, so general a Train of Absurdities, that I cannot but wonder, they were any more satisfactory to Mankind in their Days than they are to me at present. However, when the several Causes laid down by certain Authors from Time to Time, for the producing of those Creatures, are consider’d, it will not be difficult Matter to point out innumerable Errors amongst them, and deny that those Causes can produce any such Effect as a double Nature in human Bodies. The first then that I shall take notice of is that of _Constantinus Africanus_[42], who accuses Nature of being hindered, or of forgetting its duty in the Formation of the Fœtus, and by this Mistake Hermaphrodites are generated. ‘[43]It happens to some Men, in Generation, to have added to them those Female Parts, and to some Women those Masculine Parts that are luxuriant in them, when Nature is hinder’d, or grows forgetful; for when by any Accident it happens thus, that Superfluity of humid Matter that usually contributes to either the inordinate Size or Number of any Limb, goes to the Formation of a Member of any other Nature without Rule or Order.’ Before we can in any wise understand whether the Cause assigned by this Author be just or not, we must guess at what he means by the Word _Nature_. Amongst the Poets, and some Philosophical Authors, _Natura_ and _Deus_ may be conceived to signify the same Thing; in this Sense, not the least Impediment can be ascribed, nor Oblivion attributed to it. If it be a Term used to hint at the _Vis Formatrix_, or at the Matter of which the Fœtus is form’d, his Reason for giving this as a Cause will appear to be as ill grounded as any other; because as to the latter, all reasonable Men must allow, that as Matter is totally passive, it cannot be said to err or forget; and as to the former, if such an occult Power existed, it must have been by God’s Appointment, and consequently not liable to such Imperfections, in conducting so great a Work as that of Generation, with which so many Authors have taken much pains to charge this Vis Plastica; but of both these in another Place. _Avicenna_[44] sums up a great many Causes for Masculinity and Femineity, as his Translator _Gerardus Cremonensis_ translates it: For the former, or the Production of Males, the Heat and Abundance of the _Sperma virile_; its being promoted from the right Testicle; because (according to our Author) it is of a thicker Consistence, more hot, and drawn from the Right-Rein, _è rene dextro_; which is, says he, both warmer and higher than the other as being nearer the Liver; its falling into the right Side in the Coitus, _&c._ and that on the other Hand Females are engender’d by Causes contrary to these: All these Opinions he has gather’d from _Hypocrates_, _Galen_, and _Rhasus_, and because he does not seem in the least, to contradict them, we are inclin’d to believe them his own also. Now from this Manner of accounting for Masculinity and Femineity, or the Production of Males and Females, there arises a third Doctrine to which this Author seems to assent, and by which he accounts for the rise of Hermaphrodites; and tho’ he confesses that some say so; which signifies he has it from others, yet he delivers it with an Air of Approbation, and consequently was not displeased with the Hypothesis[45]. ‘And some say, that if it runs from the Right-side of the Man to the same of the Woman, it produces a Male; and from their Left-sides a Female; and if from the Man’s Left-side to the Right of the Woman, the Production will be a masculine Woman; but if from his Right, to her Left-side, it will be a feminine Male.’ If the old Doctrine[46] of Males being proper to the Right-sides, and Females to the Left, of both Sexes, in the Act of Generation, were true, (which cannot but seem obsolete before even a Capacity of the lowest Class) this crossing the Strain, in the Manner he relates, might hold, and would not be an unpleasant Method of explaining the Nature of the Growth of these Androgyni; but I believe, that Notion is so much exploded already, as not to need taking pains to Invalidate. Let us, however, accept it as this Author’s Opinion, and a Variety from that of any other; and proceed to shew, that _Lemnius_ has mistaken _Avicenna_, when he ascribes to him the Opinion contained in the following Words[47]. ‘When the Menses have come down, and the Uterus is cleansed, which happens about the fifth or seventh Day, if a Man cohabits with a Woman any time from the first to the fifth after they have ceased, a Male will be begotten; from thence to the eighth a Female; again from that to the twelfth a Male; but after that an Hermaphrodite. For the Words of _Avicenna_ according to _Gerrard_’s Translation, are very different from the above quoted by _Lemnius_, tho’ they import the same thing; yet they are far from being his Opinion, because he plainly rejects it as unreasonable, having it from another[48] Author, thus _Avicenna_[49]: ‘And some of them say, who speak without Reason, _&c._’ Now since he absolutely declares, they who think thus are without Reason, it follows that _Lemnius_ had no right to quote him, for the only Opinion he dislikes, of those contained in the whole Chapter; but to whomsoever the Opinion belongs, there is a Necessity for the following Animadversions upon it. If a limited Time was necessary thus for the procreating of the different Sexes, as, that for the first five Days after the Cessation of the menstrual Discharge, Males only are begotten, it should have been universally known by Experience long ago, since the Opinion was as early as _Avicenna_; and none of those that we daily see very anxious for Male Heirs, would ever want them, if their Consorts were breeding Women, and this the Case. Again, no Lady that languishes for a little Daughter amongst her Sons, would be long in Pain about it, if she could by Coition at any certain Time be capable of chusing one; nor in fine, would any such Appearance happen in human Nature, as is erroneously reputed Hermaphrodital, if such were never produced, but after the twelfth Day from those times of the Menses; for Mankind would, at such Seasons, avoid the Act of Generation; lest Beings so infamous, as they are superstitiously thought, should be the Product of their Embraces. ‘Yet, notwithstanding _Avicenna_ (says _Lemnius_[50]) does not account for this Doctrine, I will endeavour to reason upon it, and support it;’ which is an Evidence that he was so fond of it, that besides laying it down as the Opinion of the former, in order to gain the more Credit for the Notion, he runs into an anatomical Way of enlarging on it; the bare Recital of which, without the least Animadversion on it, will be sufficient to shew every judicious Reader, how Errors beget Errors, and may successively do so, to the End of time, whilst an implicit Credit is given to Mysteries of this kind[51]. ‘For at first, when the Uterus is cleansed by the Expurgation of the Humours, it acquires greater Heat, whereby the Semen Virile mixes the more powerfully with that of the Female, and is directed into the right Sinus of the Uterus, by the attractive Force of the Liver and right Kidney, from whence also, in these first Days, warm Blood is derived, to the Nutrition of the future Fœtus: Nor can the Parts on the left Side, being then cold, and void of Blood, immediately after the menstrual Discharge, contribute any thing; but Blood is by degrees drawn from the emulgent Veins of the left Side, which go into the Spleen and Kidney, so that, from the fifth to the eighth Day, some Blood flows from them, whereby the Fœtus is to be nourished; thus a Female is formed when these Parts compass their Strength, or are esteem’d as those of the Right out of their Situation, and also on Account of the Coldness of the Aliment. After the eighth Day, the Parts on the Right-side take the Office of preparing the Blood, which again begins to flow freely from them for the Growth of a Male. ‘After this Number of Days, because the menstrual Blood flows promiscuously, and the Matrix becomes too moist by the Afflux of cold Humours, and the Blood not being determin’d to either Part, but fluctuating in the middle of the Uterus, the Semina being there confus’d together produce an Hermaphrodite; which, when conceiv’d, receives Strength and Form sometimes from the right and sometimes from the left Sinus, enjoying the Efforts of both; Hence _Androgyni_ or Hermaphrodites spring up.’ Tho’ _Lemnius_[52] has made so large a Comment upon that Sentence, which he would have us take for _Avicenna_’s Opinion, he is fond of giving another Opinion of his own, which he supposes to account for Hermaphroditism, and that is, any unusual or indecent Execution of the Coition. ‘Sometimes this infamous Conception is form’d from an indecent and unusual Copulation, as when the Man is supine, and the Woman prone in the Act, _&c._’[53] That this cannot be the Cause of Hermaphrodites is evident from this short Reflection, _viz._ That since the Fœcundation of the Ovum which contains the Fœtus, depends upon something immitted from the Penis, I believe it matters not in what manner that Ceremony is perform’d, provided that End is answer’d; and therefore Fœcundation cannot be alter’d, nor the Seminium changed, by any Variety in the Position of the two Sexes whatsoever, during the Act of Generation; for the Effect of the fœcundating Juice will be always the same upon the Ovum howsoever it is injected. _Dominicus Terrelius_[54] imagines, the Cause to be in the Position of the Female, immediately after the Coitus. ‘After a Woman has receiv’d the Semen Virile into the Uterus, care must be had of the Position of her Body; which ought not to be supine, because then the Semen, remaining in the middle of the Uterus, does not become either a Male or Female absolutely, but both together which is call’d an Hermaphrodite.’ And tho’ this Author does not seem to think of a Number of Cells in the Uterus, yet according to his Notion for this Doctrine, he supposes Nourishment is drawn from each side of the Uterus to the Center, where he says the Semen is lodg’d, and being somewhat different, as to their Heat and Cold, the Mixture of these two kinds of Nourishment causes a promiscuous Sex; which he compares to certain Women of _Tuscany_ call’d _Lunenses_, who, says he, being careless of their Position after the Reception of the seminal Matter in Coitu, brought forth many Hermaphrodites from time to time. Now, that the Semen should lodge in the Middle of the Uterus, and not in the rest of its Cavity, is very strange, since there is but one Cavity, and no manner of Partition to confine it in one part more than another; and as to the Capacity of the Cavity of the Uterus, it is known to be very small, insomuch that if we may suppose any of that Matter passes into it, it is impossible but the whole must be fill’d, considering the Quantity of that Fluid that is generally injected at such Times. But how ridiculous a Notion must it be, that in so small a thing as the Uterus, when empty, a hot nutritious Juice should occupy one side, and a cold one the other; besides, if it were incumbent on Women, after Coition, to place themselves in a certain Position, for fear of having monstrous Children, there would certainly be great danger of the Produce of many; for we may be confident no such Care is taken at those times, by any Woman whatsoever. _Empedocles_ thinks, that in the Formation of Hermaphrodites, the Parts of the different Sexes are drawn from the Parents in the Coitus; that is, those of the Male from the Male Parent, and those of the Female from the contrary Sex that begets them. These two Sexes, join’d in one Fœtus, constitute the double Sex, and an Hermaphrodite is form’d. His Words according to _Caspar Bauhin_[55] are, Αλλὰ διέσπασται μελέων φύσις, ἡ μὲν ἐν ανδρος, ἡ δ’ ἐν γυναικος,—— If we must, from this Opinion, suppose, that no Particle in the Semen Virile can contain any thing that might contribute to the Formation of a female Part of Generation, nor in the Semen Muliebre to that of the Parts of the Male; It is to be much fear’d, something absurd must be the Consequence; for allowing that Hypothesis held and receiv’d by _Hypocrates_, _Galen_, and many of the Learned that followed them, that the Fœtus is always form’d of both these Semina mingled together, it must follow, from the Notion held by _Empedocles_, that no other than a Child of two Sexes could be produced, and consequently the entire Race of Mankind must have been Hermaphrodites, since it was necessary both should contribute something, in order to consummate the Act of Generation. Or else, that if the Females should have no such Matter, as is call’d Seminal, that of the Males would always produce a Male by virtue of theirs alone, when injected into the Female. But we are, according this Hypothesis, at a terrible Loss to know (if the Males had no seminal Matter) how a Female could be produced, tho’ the latter were never so well stored with such female seminal Matter; because, the former being without it, there could be no consummate Coitus, and consequently no Female; so that, to sum up this Opinion, we must conclude, if both contribute, Hermaphrodites must ensue; if the Males only, Males must only be born; but if Males have nothing to emit, neither Male nor Female could be begotten, and Generation must drop by Degrees. The Opinion of _Parmenides_, an ancient _Greek_ Author, appears in the following Lines, translated by _Cælius Siciensis_, from his Book which he wrote of Nature, concerning Hermaphrodites being produced[56]. ‘When the Semina of a Man and Woman are mixed together, the forming Virtue, preserving a due Moderation and Temperature, will produce Bodies properly made; for if there be an Opposition of the said Virtue in the mingled Semen, she unhappily implants in the Fœtus a double Sex.’ Here is the _Vis Informans_ accused of Opposition or Neglect in resisting, or letting the Semina go on their own way in the Formation of the Fœtus, which is much the same with _Constant_. _Africanus_’s Accusation of Forgetfulness or Impediment; and therefore what is said under that Author, will suffice for the rendering this Opinion also of little Worth. The Principles laid down by _Averroës_[57] are no less particular than others just mentioned; he says, The Semen Muliebre abounds with, or is constituted of, Particles adapted to the Nature of every Member in the Body, and in order to account for a Superfluity of Members in a Body, he draws this Conclusion from thence; that if the seminal Matter in a Female is more than is necessary for the Formation of one Child, and less than will make two, the superfluous Part will form superfluous Limbs to the one Child, according to the Nature of the Particles it contains; that is, if it consists of Particles fit for the Head, there will be two Heads, and so of the Hands, Feet, _&c._ and then he adds[58], ‘The Cause is much the same, when the Parts of Generation of both Sexes exist in any Person.’ And that on the other Hand, if their be a Deficiency of the seminal Matter, some Limb or other must be wanting. If this be thought a just Hypothesis, then we cannot but suppose, there is a great and most miserable Restraint upon the whole animal Part of the Creation; for if it be absolutely necessary that such a certain Quantity (and no more, nor less) is to be expended on the compleating of a proportionable Fœtus, I am of Opinion that not one third of the Animals of the World would escape being Monsters; and the Art and Business of Physicians would be more requisitely employed in ordering Regimens, and Calculations towards the fixing the Sustenance and other Non-naturals, in such Proportion to every Animal, as should produce in each an exact limited Quantity of seminal Matter, than in curing Diseases. But besides adjusting the necessary Quantity of such seminal Matter, it would be no less difficult to calculate a Proportion of Particles for each Part, since our Author makes some Head-Particles, some for the Feet, and so of the rest; least, tho’ the Quantity in the whole may be just enough, yet, the Head Particles, for example, might be too many, when there might at the same time be less of any other Part; so that according to this Notion, a Child might be begotten with a Head and half, and but half a Foot. But _Gorræus_ differs from _Averroës_, as _Liebaultius_ relates, who would not place the Cause of Hermaphrodites in the whole seminal Mass, but only in those Parts of it that are chiefly concern’d in contributing to the Formation of the Parts of Generation of both Sexes; and therefore, so general a mistake is not to be ascribed to him, as to the former, tho’ his Supposition is altogether as ill grounded. _Peucerus_[59] comes into a Class with _Averroës_, but tacks some little Addition to the Doctrine of the latter, of a Superabundance, or Scarcity in any Parts of the Semen, their producing a Superfluity or want of any of the Members of the Body; he says[60], ‘If for making two Bodies the Matter is deficient, but is too much for one, the Vis Plastica forms more Limbs than are natural.’ A little after he adds[61], ‘In this Manner Hermaphrodites and Androgyni are begotten, who have the Parts of both Sexes; although one of them may be weaker and of less Efficacy than the other, and sometimes it happens that one may be changed or quite abolish’d.’ This Opinion in general is pretty near that of the former Author; but when he says, that one of the Sexes in an Hermaphrodite may be changed, or quite destroyed, it is somewhat obscure, and difficult to reconcile to the first Part of his Opinion; for first, he says, pursuant to the same Cause, of the Redundancy of such and such Matter, Hermaphrodites arise, ‘quibus sexus utriusque membra insunt,’ and then, _altho’ one of the Sexes may be weaker and of no Efficacy_; nay, _sometimes one may be changed or quite abolish’d_. Indeed when he says, that one of the Sexes in an Hermaphrodite is of no Efficacy, he is right; for our reputed Androgyni, which are the Macroclitorideæ, have one of theirs so, which is the Clitoris; and consequently ought to be deny’d the Character of an Hermaphrodite; but when he says, one of the Sexes is chang’d, he can, with less right, call them Hermaphrodites. If one be changed, it must be to some other Sex; and as there are but two, then there must be a double Male or female Sex, upon the Alteration, and all this, after they have become of this double Nature, according to the Cause in the first Part of his Opinion; for a Change is consequent to the former State of the thing changed. But, in fine, when one Sex is abolish’d, there ought to remain but a perfect Man, or Woman; how therefore can this most unaccountable Variety be said to proceed from a Redundancy of Particles of any kind whatsoever. _Pontanus_[62], besides being of the same Opinion with _Averroës_, seems also to lay a great deal of blame to Heat, by which I suppose, he means the Calor Nativus, because he says[63],——he endeavours to make this plain, by likening Generation to a Vessel of Water on a Fire; alledging that a gentle Heat will render the Water hot, as well as an inordinate one; and that, as by a very great Heat, the Water will be subject to a total Evaporation, so the Oeconomy of Generation may be destroyed, or become monstrous or preposterous by the same. Innate Heat is indeed a necessary Quality that attends every Part as well as Action of animal Bodies; but I cannot conceive any Excess of Heat in such Bodies, but what is symptomatick of some morbid State, and therefore not to be assign’d as a Cause for any effect, whether regular or irregular, in Generation. By this Author’s laying so much Stress upon inordinate Heat, one would imagine, he had nothing else to blame for causing Hermaphrodites; yet he joins with _Peucerus_ so as to mention his very Words[64], in consequence of this Notion of a Superfluity of Particles producing more Members than are natural; and makes an offer at explaining this also in the following Manner; however inartful and unreasonable, let every Reader judge[65]. ‘When therefore this acting or procreating Virtue directly influences either Sex, so as to conquer or quite overcome, Women bring forth Children of either Sex; but where she partly conquers and partly is subdued, then the thing is otherwise conducted, and one both Male and Female is begotten.’ By this Manner of accounting for it, we are to suppose, when the _Vis Agens_ chiefly predominates over the Materia Seminalis, the Male Sex is begotten; and when the seminal Matter totally rules the Vis Agens, a Female is produced; but if the latter is partly conquer’d and partly overcomes, then one of both Sexes is the Consequence. How inconsiderately does this Author give way to an erroneous Principle? For it is very plain to all Capacities, if it be necessary that such a Power as he calls his Vis Agens should accompany and direct the seminal Matter, in order to assist, and carry on, the Work of Generation, that whensoever she was so overcome, as not to have any concern in the Work, or act upon the seminal Matter, it ought to be deprived of any Manner, or Power, of growing into any Form whatsoever; whereas, by our Author’s System, we find, that when this Vis Agens has any thing to do, it is only towards the Formation of a Male; because if she be, as he expresses it, overcome, the Matter will produce a Female of itself; so that, an Hermaphrodite cannot be formed, till the Matter and the Vis Agens quarrel, and strive for Mastership, when in the Scuffle, each contributes something towards its favourite Sex, and a fœtus of both Sexes is made; yet he does not say both are perfect; for, as we observ’d before, he says one is obscure, so that in the Dispute they never come off equal; and this he proves in these Words[66]; ‘Nature in Mankind in general distinguishes the Male from the Female, so that both Sexes cannot exist in the same Body, in their proper degrees of Perfection.’ This last Opinion is not consistent with the rest, because, according to his first Principles, there should be an absolute Male or Female, just as either prevail’d over the other; and an Hermaphrodite, when each was so stubborn, as to force in upon the poor Fœtus it’s different Sex. The _contrary Qualities_ of _Albertus Magnus_[67] in their Strife about the Formation of the Fœtus, are not much unlike the foregoing Hypothesis; he says, ‘When contrary Qualities join together in the Body, either of which is absolute, and, by the help of the Vis Formativa, capable of terminating in a different Sex, that then Hermaphrodites are begotten[68].’ I should be glad to find out what these Qualities are, for as the Matter is stated it is hard to apply it; however therefore, if by the Contumacy of these Qualities, a Fœtus may be impressed with two Sexes, we must conclude that human Nature is very unhappy under the Guidance of such capricious Directors; but he ought here more particularly to lay the blame to the Vis Formatrix; for tho’ according to him either quality may be complexional of and terminating in its Sex; yet, these are but as Instruments made use of by the Vis Formatrix, to work upon the Matter withal; and therefore, the Tools used by a Workman may be as well blamed for making a bad Piece of Work, as these supposed Qualities; but as this Hypothesis in general, is as weak as any of the former, enough is said of it; let us therefore pass on to another, in which we shall find a great Variety. Not a few old Authors[69] imagined there were several Cells and Ditches in the Uterus for the Reception of Fœtus’s of the different Sexes; and those who were of Opinion that the Cells were but seven, thought that three were on the Right-side for Males; as many on the Left, for Females; and the seventh in the middle for Hermaphrodites; which were generated, whenever the Semen Virile happen’d to fall into it. Another[70] supposes but three, one on each side for Males and Females, and the central Cell for Androgyni; and that ‘Nature always intends the Formation of a Male, being inclin’d to form the best; that a Woman is but a Man, having an accidental Change in the Parts, and is therefore a Monster in Nature; that a Male is always begotten, but because of the ill Disposition of the Matrix and the Object it contains, and the Inequality of the Semen, (whensoever Nature cannot accomplish the Formation of a perfect Man) a Female or Hermaphrodite must be the Consequence[71].’ If Nature intended the Procreation of no Sex but the Male, there would have been no Female; but if it was, at first, necessary, that a Female should accompany the Male in order to propagate their Likeness and Species, without which (it is evident) Generation could neither have been begun nor carry’d on, the same Necessity must always hold, and a Race of Females as well as Males ought always to continue, in order to carry on that great Work. How then are Women Monsters in Nature? The first Woman as well as the first Man, when created, were endowed with different Organs serving to Generation, tho’ in all other Respects alike in their Members; and since every Woman afterwards had no difference in the Formation of those Parts, but must have been exactly the same with her Female Predecessors, even back to the first; by what Reason can her Parts be accounted monstrous or accidentally changed? Besides, whatsoever is monstrous in Nature ought to be of no further Use in the Oeconomy of that particular System to which it properly may be said to belong, if in a natural State. But this Hypothesis is of such a Nature, as scarce to be worth taking any more trouble to confute, being the produce of a mere Monster in Nature. St _Augustin_,[72] who was more inclin’d to deal in Matters metaphysical than natural, makes a long detail of several Kinds of Cripples, and what he calls monstrous Kinds of Men, such as, those having but one Eye in the Forehead, Pigmies, Sciopoda’s, Cynocephales, and such like; and proposes this Question: Whether it was from _Adam_, or the Sons of _Noah_, that such Kinds of Men had proceeded? But seems to believe that whatsoever they be, they were brought upon the Earth by the special Appointment of God[73]. This he gives as the Cause in general, but argues that the same will hold for those particularly believed to exist in this Part of the World, as Hermaphrodites, and those of a doubtful Sex[74]. ‘The same Reason that accounts for the monstrous Births of Men with us, may serve to account also for those of Nations that are so; for God the Creator of all, knew when and where every thing should be created.’ As yet we know not of any Nation or Genus of Men heterogeneous to us in their Form, tho’ some[75] have wrote concerning such; but later Progresses and Discoveries round the World, shew us to the contrary; if such a Nation was to be found, we might indeed with some Reason, suppose them to be a Race, created on Purpose by God; but we must not therefore assent to the Saint, in imagining God to be the immediate Author of any Form in those poor Children (commonly call’d monstrous) that might be painful or disadvantageous to their well-being and Preservation; and therefore his Comparison is not justly laid down, because, tho’ the first Semina of any Species of Animals are planted by the Ordination of the Almighty, in an absolute Manner in the Beginning, from which they cannot digress in their successive Generations; yet a Woman, possessing all the greatest Beauties and Proportion in an hereditary Succession, may bring forth a Child, deformed in every Member; which can reasonably be accounted no other than one accidentally injured in the Uterus. A Word or two more of this great Man may be necessary here, to shew that amongst those monstrous Births we have enumerated from him, he was not less certain of the Existence of Hermaphrodites, than of any other, which appears in these Words[76]. ‘Altho’ the Androgyni, which are also call’d Hermaphrodites, are not often, yet, no doubt, they sometimes are, found, in whom the two Sexes are so apparent, that it is uncertain from which they should be named; however the Custom of speaking has prevail’d that they should be nominated after the superior Sex, which is the masculine, for no Body has ever said Androgynecas or Hermaphroditas.’ These amount to the Majority of the physical Causes, commonly assign’d for the Growth of Hermaphrodites; many more as unreasonable as these might be drawn from the Opinions of Astronomers[77], who have endeavour’d to account for such Births, by the Motions of certain planetary Bodies, that, they think, influence the Actions of Generation in a particular Manner, and produce Variety of Monsters; but what are already laid down, are fully sufficient to demonstrate the Errors that reign thro’ the whole; and that the Existence of Hermaphrodites being once granted amongst them, the greater the Number of Authors that strove to shew the Causes of their Generation, the greater the Distance to which Truth was banished on this Occasion. CHAP. III. _A general View of other Authors concerning Hermaphrodites._ It is observable, that when Authors are fond of having their Readers believe what they assert, they generally favour their own Opinions either in Descriptions or Figures, so much as even to stretch from the Truth of the Subject; which so far answers their Ends as to beget in some People, indolently credulous, a Belief of what they see, and leads them into an Error. This will appear, by the following Animadversions upon such Authors as I thought would further answer our Intentions on the present Occasion. _Of MANARDUS._ It is not much to be wondered at, that the Name Hermaphrodite should be so profusely made use of as it is among Men, when we find an Author of no small esteem giving the same Name, in a general Way, to such as were even troubled with several Kinds of Disorders in the Pudenda, besides a supposed Existence of both Sexes in the same Person; for _Manardus_[78] in a Letter to one _Michael Sactanna_, a Surgeon, sends him a List of the Diseases incident to the exterior Parts of the Body, with a short Definition of each, and speaking of such as he calls _utrique Sexui communes_ has these Words[79]: ‘Hermaphrodites are so call’d by both _Greeks_ and _Latins_, of which there are three Kinds in Men, one in Women. In Men the Similitude of the Parts of Generation of a Woman is sometimes in the Scrotum; sometimes it appears in the Perinæum; and sometimes Urine passes out by the Middle of the Scrotum. ‘In Women, above the Pudenda, by the Pubis, the Form of the Parts of a Man is prominent.’ It is very reasonable to imagine from this Passage, that the Author cannot, by what he has here laid down, signify an hermaphrodital Nature in a strict Sense, in any Person; because, according to our Definition in the Beginning, there should be both Sexes amply subsisting in the same Body, whereas here he says, in Men there are three Kinds of them; in Women, one; and therefore if Men or Women, how can they be Hermaphrodites? However, as to the first difference in Men, where he says, ‘the Similitude of a Woman’s Parts is sometimes in the Scrotum.’—The first Notion we can form of it is, that here is a Man perfect in the Parts proper to him; besides which the Likeness of the Parts of a Woman in the Scrotum. Now whenever any thing like a Fissure appears in this Manner, I am inclined to believe it is the divided Scrotum of certain Authors, which are no other than the _Labia Muliebria_ with the Clitoris over them, being equally protuberant to the lowermost Part of the Orificium Vaginæ. The Second is the perfect Man still supposed, and the Likeness of the Pudenda Muliebria in the Perinæum. This amounts to the same thing as the former, only the Thickness of the Labia reaches not down so far as the Fissura Magna is continued; and therefore he supposes, that beneath the said Protuberance, the rest of the Chink is the Perinæum[80]. The third Division in Men is, only the Urine issuing out of the Middle of the Scrotum. This may indeed be sometimes the Case in Men; for when the _Glans Penis_ is not perforated, or is by any Disease closed up, Nature often finds a Passage for the Urine in many Places; of which we have several Cases both from credible Authors, and also from several eminent Practitioners in Surgery who often meet such Cases. But with what Right this may be call’d an hermaphrodital Affair, I cannot imagine, and shall therefore submit it to the Judgment of the Reader. From these Considerations, it is plain that the two former of these Divisions are the very same with that State of Hermaphroditism, that the Author allows to Women, in the same Paragraph, ‘in Women, above the Pudenda, by the Pubis, the Form of the Parts of a Man is prominent.’—Now, since he allows, first they are Women and have their natural Pudenda, whatsoever juts out near the Pubis can be nothing but the Clitoris, for he does not take upon him to say, that a _Penis_ and _Scrotum_ appear, but the Form of them. Therefore Forma Penis is the Clitoris; and the Forma Scroti the Labia. Here is an Author who makes a flourishing Division of the Word, and applies it to Cases not at all bearing the least Proportion or Propriety to the Nature or Sense of it; but rather alienates and disguises it, by endeavouring to appear to his Friend the more nice upon the Subject; but however, from what has been said of him, his Division seems to favour rather of Pedantry than Judgment. _Of RUEFFE._ Another Author worthy of Note here, and from whom we may gather something towards arriving at the Truth, is _Jacobus Rueffe_, who gives an Account of a Child which he calls an Hermaphrodite as follows[81]: ‘In the Year 1519, an Hermaphrodite or Androgynus was born at _Zurich_, well form’d from the Navel upwards, but having that part cover’d with a reddish fleshy Mass, beneath which were the Female Parts, and under these, those of a Man, in their proper Situation.’[82] Let us here observe, that this Author places the feminine Parts above the Masculine, which he owns, and by his Figure appear, to be in their proper Place. Now every Anatomist will with Reason admire at the Situation of the _Rima Magna_ above the Os Pubis, because in order to have it so, the Vagina must have a Way thro’ the Peritonæum, and the Fundus Uteri must have a transverse Direction in a Right-line from the Labia Externa, cutting the Body of the Child ’cross at Right-angles; this being the case, it will be a difficult Matter to find a Place for the Vesica Urinaria, from which the Urethra ought to pass thro’ the Penis, as that appears by the Figure to be the most perfect. I confess the Singularity of the Situation of the Female Parts above the Penis and Scrotum renders me an Infidel to the Story, from the known impossibility of such a Structure. So that if such a Subject was seen, I am inclin’d to believe, that what he took for the Vulva, and would have us believe so, was no more than some particular Mark or Rima in the Skin, such things being not uncommon; and we need no more wonder at the Author’s being fond of making it what he does, than at others, and not a few, who would turn the Clitoris into a _Penis Virilis_, or whimsically turn Boys into Girls, and Girls into Boys, and therefore as he does not say, whether himself had seen it, or whether it was communicated to him, we must conjecture, that when a thing is received by hear-say, it is an easy Matter to make a Figure answerable to the Report, and place Parts of Bodies in the Situation that best suits our Story[83]; we shall find this to be pretty near the Case, when we come to take notice of _Ambrose Paræy_ underneath. In the same Chapter this Author says, that many Children are born, and even grow to considerable Ages, whose Sex is hardly upon Inspection to be distinguish’d. The ignorant (says he) believe them to consist of both, but are much mistaken; then he pretends to have seen one of these doubtful Cases in these Words[84]: ‘I happen’d to see such an Infant, whose Sex was hard to be determined; Testicles were indeed prominent without a Penis; under the Testicles there was a Rupture or Passage for the Urine, but because of the want of the Penis (nor was it totally absent, but turn’d inwards and bending downwards to the said Rupture) Nature found this Way for the Exit of the Urine. It was not baptized as a Female, nor an Androgynus, but a Male only.’ Here our Author needed not, in this Example of Ambiguity, to be at a stand with regard to the Sex, for from his own account, the Child was Male, since the Testiculi were conspicuous, tho’ the Penis might not have been protruded; and where these are in a natural State, there cannot be (as is before amply proved) any Part proper to a Female in the same individual Body. As to the Passage that nature found for discharging the Urine, this could never have been a sufficient Reason for the doubt he seems to lie under, of the Sex, because there is so wide a Difference between such preter-natural Foraminulæ and the Pudenda Muliebria. He hints, that Nature was so kind to make that Passage on account of the want of the Penis, and yet is so loth to lose it quite, as to affirm that the Penis was not entirely wanting, but that it turn’d inward, and was carry’d down to the little Aperture under the Scrotum. This is a very odd kind of Structure, and in order to give Credit to our Author, we must first suppose such another Reflection of the Penis (first to be carried up before the Os Pubis, and then turn’d down again between that and the Scrotum to open under it) as that of the Aspera Arteria in the Sternum of the wild Swan. I cannot devise by what Means Credit should be given to such Narrations as these, which so far digress from human Nature’s Laws, when not accompanied with a very nice and particular anatomick Description of such Parts; and even that attested by Numbers of Persons equally skill’d in the same Science, or a publick Society of learned Men, whose Delight it is to enquire after Truth and rectify superstitious Allegations of all Kinds, especially in natural History. At last this Author, after informing us that the Child was received and baptiz’d by the People as a Male, and not a Female nor Hermaphrodite, concludes the Paragraph thus[85]: ‘But because such Subjects are better perceiv’d by the Understanding, than by Sight; I was not willing to represent it by any particular Figure.’ He was very much in the Right not to give a Figure of this Subject from his Imagination only, which, I am sure, he as well as several other Authors have done before, without any other Authority than the Tradition of the People.’ _REALD. COLUMBUS._ This Author[86] must not want a Place amongst the rest, who after he has given an account of the Dissection, mention’d in the Conclusion of this Treatise, proceeds to relate his Observations upon two Persons which he calls a Male Hermaphrodite, and a Female one; his Words are,[87] ‘I have moreover consider’d two living Hermaphrodites, one whereof was Male the other Female.’ He gives the Story of what he calls the Woman Hermaphrodite first, which is much of a Piece with that of the other Authors mention’d hereafter. But if he had said at once, that he had consider’d the Cases of a Man and Woman, he would have appear’d a more judicious Historian, than he seems to be by adding the Word Hermaphrodite to either; which will be evident by the Sequel of his Account, _viz._[88] ‘There was one of those _Æthiopian_ Women, called, by the _Lombardians_, Cingaræ, who could neither perform as a Man nor Woman, for she unfortunately had both Sexes imperfect; the Penis not exceeding the Size of one’s little Finger, in length or thickness, and the Hole of the Vulva was so narrow as not to be capable of receiving the Top of the little Finger. This Wretch intreated me to cut off the Penis, which she said, would be a Hinderance to her in the Coitus, and also desir’d I would enlarge the Vulva, that she might be capable of receiving a Man; but I dared not grant her Request; knowing the Danger the Vessels were liable to, therefore thought it could not be done without hazarding her life.’ There is not the least room to hesitate upon this Case, with regard to the hermaphrodital Character he gives her; for it is plain from her own desire, nothing but the Properties of a Female were in her. If otherwise, she would never have begg’d him to cut off the Part which our Author calls a Penis, but in truth the Clitoris; and from her earnest Entreaty to have her Femine Parts dilated and made capable of receiving the necessary Part of the contrary Sex; for it is commonly the Case in such Women as have the Clitoris longer than ordinary, to have the Orifice more or less, covered with a thin[89] Skin arising from the Perinæum; this must have been the Case with her, and the Author might have gratified her by a Chirurgical Excision of that Part, as safely as the _Ethiopians_ and _Egyptians_ perform the same upon their own Children. And as to the membranous Covering to the Orifice of the Vagina, it might have been remedied by a Snip of a Scissars. That part in the Angolan is near half covered with the same; and not many Days ago, a Child of about eight Years old, had it almost entirely covered, which was cured in the same easy Manner. But to our Author’s Man Hermaphrodite[90]: ‘I made Observations on a living Man Hermaphrodite, who appeared as follows; He had a Penis and Scrotum with Testes, under which, in the Perinæum (that is, between the Testicles and the Anus) where the Section is made for the Extraction of the Stone of the Bladder, there was a Hole in the Manner of a Vulva, but was not deep; and these are all the Hermaphrodites I have met with.’ What an Infatuation it looks like in Men, that so little Regard should be had either to the Nature of the Subject related, or even to the very Terms made use of to express the thing they would exhibit. This is plain in our Author, and indeed I cannot but think it a great deal more necessary than is commonly imagined, that the Choice of Terms should be well concerted, and adapted to any Subject with the utmost care; because a small Difference in a Word makes a great Variation in the Idea that should be proportioned to the thing treated of; and hence, much better Terms than that of Hermaphrodite might be drawn from the Diseases of either of the Subjects our Author writes of. What could here make him suppose this Man to be an Hermaphrodite, when such palpable Marks of the Male Sex only were in his View, and not the least Sign of a Female? The following Author _Parée_ was infected with this Notion of _Columbus_, concerning the Slit in the Perinæum; which see more particularly taken Notice of under that Author. _Of AMBROSE PARÉE._ We have no more from this Author than the Sentiments of some of the Ancients concerning the Nature and Causes of Hermaphrodites, and therefore by his copying and assenting to them we may easily guess at what he thought of the Matter; however, in order to do him all the Justice imaginable, let us draw out such of his Words as are suitable to our present Purpose, and take a short View of them, by which we shall find as much will occur towards forwarding our Attempt, from an Examination of him, as from that of any other Author[91]. ‘Hermaphrodites or Androgyni are Children born with a double genital Member, one Masculine the other Femine, and are therefore call’d in our Language Men and Women.’ This Definition appears very absolute with regard to the Existence of the Members of both Sexes in one Body, which our Author easily grants, because _Aristotle_ and others after him has said it; but by considering his Division of Hermaphrodites in the next Sentence, and the Causes he assigns for them, we shall find his Account, and the Figures he has given us of them, to be partly copy’d and partly fictitious; here are then his Words faithfully taken from an Edition of his Works printed at _Lyons_ in the Year M.DC.XLI[92]. ‘As to the Cause of Hermaphrodites, it is because the Woman affords as much seminal Matter as the Man, and because the forming Faculty always endeavours the Formation of things alike, that is from the Male Part of the Matrix a Male, and from the Feminine Part a Female; which is the Reason why two Sexes are found in one Body, call’d Hermaphrodites.’ It is of no inconsiderable use, upon examining any Subject, to observe particularly the Hypotheses upon which Authors seem to build Arguments for supporting what they publish to the World; because whether they follow the Sentiments of others or no, if any Absurdities should arise from such Reasonings, the Truth must still be remote, which is in its own Nature so clear as to shine forth without much Strife, when Arguments are founded upon Facts fairly stated. Let us therefore take notice of our Author professing, according to the Ancient Notions of Generation already hinted at, that an Hermaphrodite is produc’d from an equal Quantity of the Semina of both Male and Female, elaborated together with equal Force; which by virtue of the Vis Formatrix, or Vis Plastica, (the Author’s _Vertue Formatrice_) which he says, endeavouring always to form things alike, is the Reason why two Sexes are form’d in the same Body. The present Notions of Generation are greatly different from what is here the Faith of our Author, because a better Knowledge of the Structure of the Parts, which are the Instruments of it, has taken Place; and certainly an Hypothesis is better founded upon an experimental Fact, than upon bare Supposition; for the Ancients, who knew nothing of the Uses of Ovaria, nor Fallopian Tubes, had no other Way of accounting for Generation, but this of our Author, which they suppos’d from only being sensible of an Injection of something in the Coitus from the Male, and again, from believing something to exist in the Female, which they also called Semen, the natural Conclusion that arose from this Consideration was, that an admixtion was made of both, and in order to complete the Work, that occult Finisher, ‘the Vis Formatrix,’ was summoned to assist till the Fœtus was moulded out. The most illiterate Grooms have the same Opinion ’till this Day (tho’ they never knew it was said by any Author) drawn from the same natural Reason only; for I have taken notice of one thing they do instantly after a breeding Mare is cover’d by a Horse; which is to throw a large Quantity of Water, that is always prepar’d for that Purpose, about her back Parts, which they say is done in order to make her cringe, and keep what she has received. And I have further observ’d, that when any Part of it has been rejected, immediately after the Coitus, by the Mare, they have despaired of any Benefit from the Access of the Horse. Hence it is plain that the Causes assign’d by our Author for the Production of this double nature in human Bodies, can produce no such Effect; for the World is by this time assur’d, that the Mechanism of Generation is otherwise carry’d on, and that no animal Being whatsoever is generated in the Manner laid down by our Author and his Predecessors, therefore no Hermaphrodite can be the Effect of such a Scheme of Generation. But now to his Division[93]: ‘Of which there are four Divisions, to wit, Male Hermaphrodites, who have the Male Sex perfect, and can engender properly, and have a Hole like the Vulva in the Perinæum, not at all penetrating into the Body, from which neither Urine nor Semen passes.’ This Division of Hermaphrodites differs in some measure from that of _Manardus_ and _Laurentius_, but is of as little account as either. This first Part of it declares a perfect Male, which he owns to be capable of Procreation; and because he finds (or supposes) an accidental Mark like a Slit or Hole in the Perinæum, he makes this Male an Hermaphrodite in an instant, though at the same time he confesses the Hole to be always superficial, as not at all penetrating into any Part of the Body, and that neither Urine nor Seed can pass thro’ it. If it should happen to a Man to have an accidental Wound near the Privities, or to a Woman to have any kind of Wart, or Tumour near hers, we might with as much right account them Hermaphrodites, as _Parée_ does this Male Child with the Slit in the Perinæum[94]. How therefore can such a Hole or Slit which is totally superficial, and can have no Manner of use ascribed to it, entitle a Boy to the Character above-mention’d? This is writing for writing’s Sake; but to proceed[95]. ‘The Woman Hermaphrodite, besides the Vulva which is well formed, and from which flows both Semen and Menses, has a Penis Virilis, situated above the said Vulva, near the Groin, without a Præputium; but having a smooth Skin, which cannot be turned back; without any Erection; from which neither Semen nor Urine can pass; and having no Sign of a Scrotum, nor Testicles.’ This second Sort is what our Author calls his female Hermaphrodite; in this he owns the feminine Parts perfect and capable of all the natural Functions and Offices proper to them; but adds, that they have over them what he calls a Membre virile: It is very odd and preposterous to account this Part a Penis virilis, to which he does not allow a Præputium, Power of Erection, a Passage for the Discharge of Urine, nor the least Sign of Scrotum nor Testes; his Opinion is just indeed, when he calls this subject a female; but when he tacks to it the Word Hermaphrodite, and calls the Clitoris a Membre virile, which should have all the Properties he denies it, in order to it’s being so accounted, his Notion seems as injudicious as it is useless. But to his third Division[96]: ‘Hermaphrodites, which are neither the one Sex nor the other, are altogether excluded and exempt from the Power of generating, their Sexes being quite imperfect; and situated beside one another, and sometimes one above the other, serving for no other Use than for the Discharge of Urine.’ In the two foregoing Divisions, this Author’s Fondness of calling Men and Women, each perfect in their Sex, Hermaphrodites, is very culpable; but in this his forging a new Kind is inexcusable; for he has put two Figures in his Book to explain this Division; the first of which is that of a single Body, with the Vulva on the Right Side, and the Penis and Scrotum on the Left, close to each other, over which he has this Inscription[97]: ‘The Figure of an Hermaphrodite, Man and Woman.’ And yet in this Division he describes the same Kind, and calls it[98] ‘neither one nor t’other:’ declares them incapable of Generation, and that their Parts serve for no other Use than for the Discharge of Urine; but leaves us in the Dark as to which of the Parts, or whether both, serve to this Use. Now as by the Inscription over this Figure he intends to demonstrate both Male and Female, which is his fourth Division; and by his third Division, he describes the same Figure to be neither the one nor the other; it is no difficult Matter to perceive this Figure is purely invented to illustrate what an Hermaphrodite is in general, according to the Idea he himself had formed of it. The second is a Figure of two Children sticking together by the Backs, to both which he puts the same Marks of the Parts of Generation as to the former, as if both Children were Hermaphrodites; and, indeed, he might have as well placed the Parts of fifty to the same Body, as to have been guilty of what appears to have been his common way of proceeding, for he feigns or borrows Figures to serve every Occasion; this clearly appears by comparing this Author’s Figures with those of _Jac. Rueffe_; for he makes one of the Figures of that Author serve to illustrate two different Stories; he tells of Monsters with four Hands, and as many Feet; but this, with several others of the like Kind, may be the Subject of another Place[99]. ‘Hermaphrodites, that are both Male and Female, are such as have the two Sexes perfectly formed, and capable of Generation.’ As to this fourth Division he makes of Hermaphrodites, which is allowing the Parts of both Sexes Perfection, as well as a Power of exercising either to the same Person, I believe, from what has been said, this, as well as the others before, may be set at nought; however, a Word or two more concerning the Reasons and Causes he assigns for Hermaphrodites will further confute this Author. The Cause he says is, as was before mentioned, an Elaboration, or working together with equal Force in all Respects, of the Semina of both Male and Female, in the Uterus, that produces the two Sexes in one Body. Now since according to this System several of the old Authors, from whom he had this Opinion, held the seminal Matter to be as absolutely necessary to Generation in a Woman, as in a Man; and as they were strongly of Opinion, that a Kind of Paste was formed of both together, to make a Fœtus compleat, an equal Quantity on each Side ought to produce the more perfect Child, and not at all any thing monstrous, even (I say) according to this very System, held by them; and this agrees so well with another Part of their Opinions in general, (which is, that a Defect in the Quantity of the seminal Matter on either Side was the Cause of a Deficiency in some Member or other of the Offspring) that it is surprizing to find that Reason assigned for a Cause of a monstrous Production, which necessarily appears to be, in their own way of arguing, a much better one for the Formation of a perfect Child. _ANDREAS LAURENTIUS._ In reading some foreign Authors, who wrote large Pieces in Medicine[100], it plainly appears, (as I have before hinted very often) they did little else than copy from one another, because probably as they were ambitious of writing, and one strove who should excel the other in the Quantity more than the Merit of the Work, so the Improvements that might reasonably be expected from succeeding Writers lay neglected: Whereas if that beneficial Method, so much the Practice of our own Authors, was but prosecuted by some of those Foreigners, of handling and considering any one particular Part of the Science, they might have had Time to be somewhat more accurate and instructive. Our Author seems to be of that Set, who thought so well of the Division of _Manardus_, concerning the Doctrine of Hermaphrodites, that he was content to write the same Thing with that Author, with very little Variation. And as we have considered him already, the less of this present Author will serve, and that only a comparative View of both, which, I hope, will be found necessary in this Place[101]: ‘Such as have two Natures are called Hermaphrodites; in Men it happens three different Ways; when there appears a small Vulva in the Perinæum; again in the Scrotum, but without any Discharge of Excrements, and the same with a Discharge of Urine; in Women one Kind; when a Penis is prominent in the Place of the Clitoris, at the lower Part of the Pubis.’ Now the Difference that we find between these Authors is, that the _Muliebre pudendum exiguum_ of the former, is the _Similitudo muliebris pudendi_ of the latter. And also our Author, instead of saying, with _Manardus, aliquando in Scroto_, says _cum itidem in Scroto, sed nullo excrementi profluvio_. This he adds in order to make _Manardus_’s Division more distinct; because that Author says, in his third Division, _aliquando per medium Scrotum Urina exit_, which is much the same with _in Scroto_, only attended with a Capacity of discharging Urine; and therefore _Laurentius_ calls his third Division, _ibidem exeunte Lotio_. In the whole Matter, this is the mere Doctrine of _Manardus_, but in other Words. Now though our Author has done with him, he has a sneaking Kindness for _Rueffe_ and _Parée_, which is manifest in the very next Line, which is thus[102]: ‘Some add, that above the Root of the Penis the Parts of a Woman are apparent.’ This is expressed by _Rueffe_ in his Description of the Child with the fleshy Substance about the Navel, as is before-mentioned under his Name. Again[103]: ‘In Women, when the Penis is situated either in the Groin or Perinæum.’ As to the Penis in the Groin, he has taken that Hint from those Figures of _Parée_, which are before clearly proved to be fictitious; but because I have not taken notice of any mention, in any Author, of the Existence of a Penis in the Perinæum, I am inclined to believe this Part of the System to be of _Laurentius_’s own coining, and refer it to the Judges in Anatomy whether any such Structure can be blended with human Nature. _JOHANNES RIOLANUS._ It is very observable, that several Authors, in treating of this Subject, notwithstanding they run into such flourishing Divisions of the Word Hermaphrodite, yet are commonly sure, before they conclude, to disown, or, in a great Measure, contradict those very Assertions which, for Art’s Sake, they at first ventured on. This shines in our present Author, who, after he has described the Parts of Generation, proceeds to recount the Diseases of them which he calls his _Consideratio Medica_[104]; and under that Head[105], amongst the Diseases of the Urethra, he brings in some Species of Hermaphrodites, as though none were entitled to that Character but such as had Disorders in those Parts proper to Men; but from what he says of them, nothing can occur to any reasonable Person but a Notion of the real Diseases of the Parts, however he came to call them Hermaphrodites, which Name is applied here with as much Impropriety as with any other Author whatsoever. His Words are[106]: ‘Hermaphrodites belong to the Urethra and Scrotum, if the Testicles should be hid in the Peritonæum, and the Scrotum empty; or opened in the middle from a Perforation in the Urethra; when the Sides of the Scrotum are like the Labia of the Pudenda of Women, and the Penis also very little; these Things have deceived ignorant Midwives, who often think such Children females at their Birth.’ Now it is plain, that tho’ he brings these Accidents and Diseases under that Denomination, which (as he was Professor) must have been only by way of School-Method, yet his Conclusion of this Paragraph shews that his Opinion was, that the Testes remaining hid in the Peritonæum, and the Scrotum empty with an Aperture in the middle, the Penis being extreamly small, were all Accidents that happened to the Male Sex, though judged to be Females by the Ignorance of Midwives, at the Time of their Birth; and, indeed, though the Testes may be not as yet come down, nothing can be conceived of such a Subject but the true Male Sex; but if the Sides of the Scrotum look like Labia, it must be a female Case with a prominent Clitoris, for it is absurd to think the Scrotum can be divided, as we have proved above. Again, this Author, after taking notice of some other Diseases of the Urethra of Males, and their Scrota, utterly denies that Females can be changed into the other Sex, but that Children reputed Females from some of the forementioned Disorders, have always proved to be Males in the End[107]. ‘Such Subjects, after being thought Females, have at length proved Males, for no Woman was ever changed to a Man; but might be misjudged by the Length of the Clitoris, or an Hypersarcosis, arising from the Uterus, which might be in some Measure like a Penis in Form and Hardness, but not at all in the Composition or Structure, _&c._’ In this Paragraph he is very particular upon the Reports of a Change of Sex, and adds, to the two former, these two other Ways of the Vulgar’s being deceived with respect to such Changes; as if he had said, ‘I know of no other way for changing a Woman into a Man, except you’ll have it that a long Clitoris, or an Hypersarchosis, growing out of the Vagina makes a Man.’—This he confirms again in his thirty-sixth Chapter of the same Book under his Medical Considerations on the feminine Parts of Generation, under the Head of _Morbi Peculiares_, where when he comes to the Clitoris he says[108]: ‘The Clitoris sometimes grows inordinately long, and counterfeits a Penis; it is called a Tail with which Women abuse one another; these are called Hermaphrodites, or Fricatrices, nor was it ever known, and it is impossible, that a Woman should be transformed into a Man. But a Male Child at it’s Birth being thought a Female, as was said before, when his Parts begin to come out which lay hid, may, indeed, become a Man.’ Hence it is plain, that our Author would make Use of the Word Hermaphrodite, not as crediting such an Existence, as it expresses, in human Nature; but as thinking it a Term fit only to serve him in his Explication of some of the Diseases of the Parts of Generation. _REGNERUS DE GRAAF._ This Author, in his particular Description of the Clitoris, gives a History of a Child born with that Part so large, that all who saw it pronounced it a Male Child; and it was accordingly baptized as such, and securely allowed to be a Boy. However, _de Graaf_ had no such Opinion; for the Doubt that he, and others of the Faculty of Physick were in concerning this Child, caused a more narrow Enquiry into it’s Nature, which was favoured by it’s Death; and the Result of their Examination is very positively expressed by him thus[109]: ‘But an accurate Dissection of those Parts after Death has detected the Deceit, _&c._’ The History in full, with the Figure, he gives in another Place[110], of which let us consider the following Particulars. When this Child died, our worthy Author, in Company with several Physicians and Surgeons, first had a drawing made of the exterior Appearance of the Parts of Generation, and then proceeded to open the Body, upon which they found the Uterus, Ovaria, Tubes, and spermatick Vessels according to the Standard of Nature; but seeing no Scrotum, they searched in the Groins and elsewhere for Testes but in vain; for neither these nor any other Signs of a Masculine Nature could be found. Then they proceeded to examine whether there was any Passage in the Clitoris, but were foiled in this also; but found the Urethra under it in the proper Place as in all Females, through which they passed an Instrument into the Bladder. Afterwards they inflated this Part (first stopping the Orifice of the Vagina) which when it was very much distended, they compressed greatly to see if any Air could pass out by the Clitoris, but this likewise was to no Purpose; at length they cut the Clitoris across, but found not the least Sign of an Urethra, nor any other Thing but what is proper to that Part. From whence he concludes, that though it resembled a Penis virilis in all Respects,[111] ‘Yet we pronounced it not a Penis, but the proper Part of a Female, known by the Name of a Clitoris.’ Here is a Series of strong Experiments upon this Child, to prove very sufficiently that these Kind of Subjects are only Female, after it was received as a Male by all that saw it; and yet this great Man’s Figure of the Thing must have inevitably produced a greater Notion, in us, of the Predominancy of the Masculine Sex, than of the other, if the above History and his judicious Explanation were not annexed to it; only because he had asserted it was like the _Virga virilis_, and therefore had it drawn in a Position that favoured that Assertion, and gave the whole as much of the Mien of that Sex as possible; for though he denies (in his Description) any Perforation to the Clitoris, yet in the Drawing it appears to have one at the Extremity; so that this joined to the close Position of the Labia under it, which appear very protuberant (though nothing was found in them) without the least View of the vaginal Orifice, entirely conceals the natural Sex, and actually represents the contrary. Thus we may easily see how necessary, and of what Consequence it is towards the Exhibition of Truth, to dispose of any Subject in a natural impartial Attitude or Light, either for describing or drawing, because no other Idea could be conceived of our Author’s Figure but what I have expressed above; whereas if he had either drawn it with the Labia open, or made a second Figure to represent the inferior Part next the Anus, looking upwards at it, so that the Nymphæ might come in view, it would have been more analogous to so just a Description as he has exhibited. _Of DIEMERBROECK._ To examine this Author, concerning his Opinion of Hermaphrodites, will be extreamly worth while; for we shall find him making the strongest Efforts to persuade the World, that a seminal Matter issues from the Clitoris, and making a great many Shifts to prove it, as if he had a Mind to introduce a Notion of a Power of ejecting a seminal Juice, from that Part in those Confricatrices, and thereby to render them equally capable of the Coitus in the Quality of either Sex: But how strange an Appearance does it make, to find him, in the end, giving Histories of several of these reputed Hermaphrodites, with some Animadversions on them, which serve to overturn and confute what he has taken no small Pains to maintain before. This Author asserts, that the[112] Semen is brought partly from the Testes and Tubes by the Ligamenta Rotunda (which he calls Vessels, and adds, that heretofore they were improperly called Ligaments) and so emitted by the Glans; but how a Communication is carried on between these Ligaments and the Clitoris he has not given us the least Account; yet he persists very strenuously in that Opinion, tho’ he owns at the same Time, that upon the Dissection of these Parts no convenient Passage appears for such an Emission, and this turns him upon another Method of accounting for it, which is, that the Pores of the Glans are so distended by Heat, Agitation, _&c._ that Semen may easily pass forth. He backs this Opinion with a Story he tells, of a Patient that complained to him of an involuntary Emission from that Part, occasioned by her too frequent provoking it before; part of the Words of this History may not be amiss, in this Place, for the Reader’s Satisfaction[113]. ‘Lately a Woman of no little Credit complained to me, that in her younger Days, having early Desires, she often rubbed that Part (the Clitoris) with her Finger, so as to provoke the Emission of Semen with much Delight, and that in some time this ill Custom caused it to become a Disease.’ Here he makes a Passage through the Ligamenta Rotunda for Semen to come to the Clitoris, in order to make a close Analogy between the Penis and that Part; and, finding no Urethra, makes it pass out by the Pores of the Glans, and by way of Confirmation of his Opinion, tells the above Story from the Mouth of the Woman herself, believes her, and would have the World give Credit to it also. In another Place[114] he absolutely confesses, no Passage like an Urethra has hitherto been found upon Dissections in that Part; yet Reason (says he) tells me there must be one, though in dead Bodies it disappears; otherwise I demand by what Passage can such a Discharge proceed from these Confricatrices and Hermaphrodites. His Words are, ‘Mulieres Confricatrices atque etiam Hermaphroditi.’ As if these two Characters signified different Things, which in other Authors are esteemed the same. This is rivetting his Opinion of an Urethra, though none can be found, and totally omitting to make any more Use of his Argument of the Pores, whether wilfully, as believing it a weak one, or through Forgetfulness, we cannot say; but his subsequent Histories will shew, how he tumbles from this Notion into a direct Contradiction of a pervious Clitoris; and as to his Pretence of the Ligamenta Rotunda’s being Vessels, every Anatomist is able to make a Judgment; and also of what Use it is to have a Discharge from the Clitoris, those in any wise acquainted with the Nature of Generation, and the Structure of the Parts, will easily refute. Now we shall proceed to take notice of some of the Histories he gives concerning enlarged Clitorides in Women, which he takes from several Authors, and introduces in these Words[115]: ‘In Hermaphrodites this is the Part which, as it grows, resembles the Penis; this is plain, because no Perforation can be discerned in it.’ This Sentence very much weakens his guess’d Opinion of the Urethra, which he does very often afterwards in his several Stories of these Creatures. The first he saw was in _France_, of about Twenty-eight Years of Age, which was shewed to the People for Money; he describes her thus[116]: ‘This Subject, on the upper Part of the Pudenda, had a Clitoris as long as one’s Finger, and as thick as a Penis; with a Glans, Frenulum, and Præputium, as are seen in Men, except that the Glans was not pervious; below this there was an urinary Passage, and the Vagina Uteri as in Women; in each Labium there was a Testicle.’ In this History our Author owns, there was no Perforation to be seen in this large Clitoris; and as to the other Parts he describes no more than a perfect Woman. Another of these he saw at _Utrecht_, which her Owner told him was a perfect Female till between five and six Years old; at which Time she began to change, and at Eleven a Penis was grown conspicuous, but without a Perforation: the said Man told him also, that she had then her Menses periodically as other Women. She had below the Clitoris the Meatus Urinarius and Vagina properly situated, to which he adds a Testis in each Labium; and further, that there was a seminal Discharge upon Occasion, but that the Hermaphrodite did not know whether it was by the Clitoris, or the other feminine Parts. His Narration of this History begins thus, of which we shall insert but a few Words, the Substance being just mentioned above[117]: ‘In Company with other Spectators, I have seen such another _English_ Hermaphrodite, twenty-two Years old, here at _Utrecht, &c._’ This is the Subject Dr _Allen_ speaks of in the _Transactions_, which has been taken notice of before in this Treatise, that was carried to _Flanders_, and shewed to our Author; now whosoever will be at the Pains to compare the Descriptions given by both these Authors, which they had only from the Mouth of her Keeper, will see how they differ, and consequently what Untruths proceed from Hearsay; now after all these Things, our Author makes this Conclusion of his own Accord[118]: ‘From all which it is plain, that these Kind of Hermaphrodites do not partake of both Sexes, but are only Women, whose Parts of Generation are illy formed, that is, the Testes have descended out of the Abdomen, and the Clitoris is grown too large.’ It would have been much more to the Credit of this Author to have subscribed to this Doctrine at once, without endeavouring to maintain, in so uncertain a Manner, any Thing that had the least Hint towards allowing a Perforation in the Clitoris, or a virile Nature to a Woman, and so suddenly to quit and contradict his former Opinion, in his Histories and Animadversions on them, which must be very obvious to any one that will allow himself Time and Liberty to consider the Animal Oeconomy, and the Laws of Nature, as far as they respect human Bodies. _Dr DOUGLAS._ The Explanation of the Figures in the following large Plate, which this most consummate Anatomist has favoured me with, are sufficient to shew, that these Sort of Subjects are, in his Opinion, Females in all Respects. The first Figure he had delineated from the _Angolan_ in a most accurate Manner; and the other two were done some time ago, as appears by his Explanation; of both which he had given Copies to the ingenious Mr _Cheselden_, which he has in his Book of Anatomy. In making these Figures, the Doctor, according to his accustomed Accuracy, avoids the Omission which _De Graaf_ is guilty of; for though the latter’s Dissection and Description of the Subject that came before him are very satisfactory, in proving it Female, yet inasmuch as he has not shewed any Part of the Orificium Vaginæ in his Figure, it is not so much to the Purpose as those of Dr _Douglas_. This Woman was carried from _Angola_ in _Africa_, amongst other Slaves, to _America_, from whence she was brought to _Bristol_. She is about six and twenty Years old, has no Beard on her Chin, nor any Thing masculine in her Countenance; her Arms above the Elbow are thick and fleshy, as many Womens are, but soft; her Breasts are small, her Voice effeminate in the common Tone of speaking, and it was reported she has often been lain with by Men; and as to the Parts of Generation, they are so justly described in the following Explanation, that the Reader is referred to that. [Illustration: _A View of the external Parts of Generation in the ~African~ Woman, that was brought lately from ~Angola~, exactly delineated from the Life, and well engraven._] FIG. I. 1. The _Regio Pubis_, with _Pili_ upon it. 2. A Tumour or Swelling between the _Inguen_, and the upper Part of the _Labium Vaginæ_. 3. _Nympha Luxurians_, or as this Part is commonly called, tho’ very improperly, _Clytoris, magnitudine aucta_, that is, the true _Nympha Muliebris_, which is enlarged to an uncommon Length and Bigness, in which we may observe it’s _Cutis Rugosa_, or wrinkly Skin, which terminates in a _Præputium_, here turned back to shew it’s large _Glans_, in which there is not the smallest Perforation or Opening. 4, 5. The Labia opened and turned back, to shew the Entrance into the Vagina; the Labium on the left Side is of a natural Bigness for the Size of the Woman; but the other Labium is very large, in which is contained a hard Substance, surrounded with something soft to the touch, and which may be traced as coming down from the _Inguen_. This Tumour, in my Opinion, is the real _Ovarium_ or Testicle of that Side prolapsed, and fallen down from it’s natural Place within the Abdomen, thro’ the Fissure in the Muscles belonging to the last mentioned Part, into this Labium where it is lodged, covered with an Elongation in Form of a Bag or Sacculus from the _Peritonæum_, in which it lies enclosed together with the _Tuba Falloppii_, the _Ligamentum uteri latum_, and the Ligament that goes from the Testicle to the _Uterus_, in the very same Manner that the common _Hernia_’s, whether of the Intestinum, the Omentum, or both, are produced in Women. My Reasons for this Conjecture (which was long ago simply proposed by Professor[119] _Diemerbroeck_, but without any Manner of Proof to support it) shall be given in a general Treatise of _Hernia_’s, which I have very near finished, and, I hope, will be published in a short Time; the Ovaria, or _Testiculi Mulierum_, being in the Number of those Parts that fall down from their natural Situation, and constitute that Disorder we call a Hernia or Rupture. In my Collection of the morbid uterine Parts, I have two Preparations where the Ovaria and Extremities of the Tubæ Falloppianæ lie exactly on that Part of the Peritonæum, under which the _Ligamenta uteri teretia seu rotunda_ do pass out from within the Abdomen; and the _Fundus Uteri_, instead of lying backwards on the _Intestinum rectum_ and _os Sacrum_, is turned forwards, and lies on the Os Pubis and Vesica. This, I own, is only a conjectural Proof for the present, a real one cannot be offered till the Part itself, where the Tumour is, can be examined by ocular Inspection. The Tumour marked 2, I take to be the Ovarium on the other Side, just clear of the abdominal Muscles, but not come low enough for the Labium, but will no doubt in Time, if not prevented by some outward Compression. I am informed, that the other Tumour came down gradually. 6, 7. The slender _Alæ_ or _Pterygia vaginæ_, improperly called _Nymphæ_. On the upper Part of these cuticular Foldings, the _Frenulum_ 6, is observed to be lost, that comes obliquely downwards from the under Side of the _Glans_. 8. The Orificium, or Entrance into the Vagina, with a smooth whitish Skin on the Inside of the Labia. 9. The Furcula Vaginæ. 10. The large and broad Perinæum, or Distance between the Furca and the Anus. The second and third Figures represent the external Parts, as they appeared in a Girl shewed about Town for an Hermaphrodite, of which I gave an Account that was read at a Meeting of the Royal Society, _Feb. 17, 1714_. FIG. II. Shews these Parts in a natural Situation. 1. Nympha Luxurians seu Clitoris. 2. Labium dextrum. 3. Labium sinistrum. FIG. III. Shews the same, the Labia being deducted or turned back to each Side. 1. Nympha Luxurians, seu Clitoris. 2. Labium dextrum. 3. Labium sinistrum. 4. The Alæ, Pterygia vaginæ, or Nymphæ vulgares. 5. Orificium vaginæ. 6. Furcula vaginæ. In this Account also I supposed the Tumours to be from the Ovaries fallen down. _N. B._ At this Time I protest I neither had read nor heard of _Diemerbroeck_’s Opinion. Here, it is plain, is nothing but what is common to every Woman; and whatsoever Appearances may be in her, such as the Largeness of the _Clitoris_, and that Tumour in the _Labium_, that are capable of raising other Opinions, they may be deemed a morbid State in the Accretion of the Parts; and as to the said Tumour in the Labium, several of the Learned are divided about it, and their different Opinions amount to three, _viz._ 1. That such are Testes like those in Men. 2. That they are Herniæ of the Ovaria. 3. That they are Glands of an indolent Nature, void of any Use, fallen from the Groins, and grown inordinately large and hard from the same Cause that enlarges any other neighbouring Parts that exceed their natural Size. To the first of these Mr _Cheselden_, and, I am told, some others in Town, seem to assent. The second is the Opinion of Dr _Douglas_, for which see his Explanation. And the last is the Conjecture of Sir _Hans Sloane_. However, as none of these Opinions can be ascertained without a fair Dissection of such a Subject, as this is, in all Respects, and that by the best Anatomists; and tho’ many Queries and Arguments might be exhibited both for and against these Notions, we chuse rather to omit controverting any one Point, as to this Particular, for the present, and refer the Matter to the first Experiment that shall happen upon such an Occasion. CHAP. IV. _The CONCLUSION._ _Containing a Description of a Fœtus, and a Recital of the Dissections of such Subjects by some other Authors._ The Examination of any more Authors upon this Topick would amount to more Pains than at present are necessary, and besides, Repetitions could hardly be avoided if any more were called in Question, since we find Authors were so fond of running in the same Path with one another; therefore the Remarks that have been made on those already mentioned may, I hope, be sufficient (together with the rest that has been said) to answer the End of this Treatise, which is no more than to illustrate the Cause of the first Rise of the Notions of Hermaphrodites among Men; to shew how credulous our Ancestors have been of these Chimera’s, and how fond of encouraging their Progress tho’ in the meanest Manner of arguing; to prove, by comparing all the Opinions of Authors, that no hermaphrodital Nature can exist in human Bodies; and, in fine, that those Subjects hitherto so accounted, were only Females in all Respects, superstitiously, and through Ignorance, mistaken for those Kind of Creatures, or for Men; which, with some other Disorders of the Pudenda of either Sex, gave rise to the several Divisions that afterwards sprung up concerning them; as far from Truth (or even rational Conjecture) as any other Error that ever was received by Mankind. And this will still be further illustrated by the following Description of a Fœtus, with a very large Clitoris, that came to my Hands some time since, which I have taken due Care of for this Purpose. This Subject was an abortive Fœtus of about six Months Growth, in which (though so young) the Pudenda are conspicuous enough, and the Clitoris sufficiently large to prove every Thing that has been said upon the Subject; and to serve as a Standard, wherewith to confront any fabulous Reports that may hereafter spring up in the World, which I have endeavoured to describe in the most faithful Manner that I am capable of. But before we proceed to this Description, it will be of great Use towards the Design of this little Work, to insert the following Observation; which I had the Honour to lay before the _Royal Society_ on _Thursday_ the 30th of _April_ 1741, and which, I hope, will add no small Force to what has been already said upon it. All female Fœtus’s, during the greatest Part of the Time of Gestation, have the Clitoris as large in Proportion to their Sizes, and sometimes larger, than the _Angolan_ Woman before-mentioned, which is evident from several then shewed together to the Society; this, I am inclined to believe, is Nature’s common Rule all over the World. Now it is impossible that so many Hermaphrodites should be found at once, since we have so very few Instances among the _European_ Nations of those so reputed; though, as is before observed, they are common enough in _Africa_ and _Asia_, in all those Places especially that are nearest the Equinoctial Line; where the Nonnaturals themselves conduce much to the general Relaxation of the Solids, and consequently, this unseemly Accretion of that Part. Now as the Fœtus increases in a natural Way, the neighbouring Parts of the Pudenda grow more in Proportion than the Clitoris, drawing away the Integuments, whereby it becomes by Degrees less conspicuous; but when it continues it’s Growth, together with the rest, maintaining it’s first proportional Size, the Person is reported to be an Hermaphrodite; the natural Structure of this Part being in a great Measure like that of a Penis virilis. Nor is it’s Largeness in a Fœtus much to be wondered at, since there are other very similar Cases in the same Body, as the Gland _Thymus_ and _Glandulæ Renales_; nor is it, indeed, any more wonder to find it’s Growth increased, when once continued till a little after Birth; because Erections of that Part begin very early in Children, which, protruding the Integuments, increase their Relaxation, and thereby remove all Obstacles to it’s Luxuriancy. First then in viewing the Parts from above downwards, the Clitoris appears very large in Proportion to the Size of the Subject, and juts out in the Place which is always the Seat of that Part, according to Nature. It is circumscribed round the Root chiefly, on the upper Side, by a Ridge of the common Cutis, which reaches from one Side, continued with the Labium to the other. The Præputium, indeed, is not to be well distinguished, because of the Minuteness of the Fœtus; however it shews very plainly, that a Continuation of the common Skin of the Clitoris is lapped round the Substance of this Part, and meeting at the very Extremity on the under Side, forms an Angle, from which the Nymphæ arise in an equal Point, and are inserted also on the Sides of the Orificium Vaginæ, being very large and conspicuous. What appears to be a Rima or Slit in the Extremity of the Clitoris, in the Opinions of many, is no other than the Angle made by the Plication of the two Nymphæ where they arise, which undoubtedly is always the natural Case, and no other, in every Subject of this Nature. The Labia are like those of any other female Child, continuing from the Ridge round the Clitoris, and terminating regularly in the _Perinæum_, being somewhat more protuberant at their middle than at either their Origination or Insertion. The Vagina is in a natural State, and as for the Meatus Urinarius, it is too minute in this Fœtus to have any Observation made of it. This is all that is necessary to be said of it by way of Description; but I have subjoined the two following Figures of the Parts of Generation of this _Fœtus_, in order to make the Observation on them still more obvious and plain, which I have done something larger than the Life, in due Proportion, because a Drawing of the same Size with the Subject would be too small for Explanation; but have, at the same time, taken the utmost care not to digress from the Truth in the least, in order to favour any particular Fancy whatsoever. [Illustration: Tab. III. FIG. I. A View of the upper Side of the Clitoris and Labia, the under Parts being hid. FIG. II. The Pudenda turned upward, and laid open. 1. The Umbilical Rope. 2. The Clitoris. 3. The Labia. 4. The Nymphæ. 5. The Orifice of the Vagina and Anus.] But having understood that some were particularly of Opinion, that such as have the Clitoris long have no _Uteri_, I opened the above-mentioned Fœtus, and found the Uterus in it’s natural Situation, with every Appendix proper to it, in their Places; which, with the Dissections made by several Anatomists upon such Occasions, will be very prevailing, to manifest the Existence of an Uterus in every _Macroclitoridea_, whether any Thing be contained in the Labia or not. 1. _De Graaff_’s Dissection, mentioned before, is no insignificant Proof of this Assertion. 2. Another made, and related by _Columbus_, will be also as corroborating, of one whom he calls a Woman (and, indeed, without any Mistake) he introduces the Description of her in these Words[120]: ‘Formerly I happened to see a Woman, who, besides the Vulva, had also a Penis, which was not very thick.’ This Membrum virile is (beyond all Dispute) the Clitoris, because he says _præter vulvam_; and, I hope, from what has been said before, it is plain, that no Male Parts can possibly grow with the Feminine in the same Body; however, this Author proceeds to describe the Blood Vessels, _&c._ to which I refer the Reader, and shall only pass on to observe what is to my Purpose here, which is contained in his following Words[121]: ‘The Uterus and Cervix did not in the least differ from those of other Women, but there was a Difference in the Testes, for in this Subject they were thicker than in others, but their Situation was the same. There was no Scrotum at all, and the Penis had two Muscles, not four, as in perfect Men; besides, the Penis of this Hermaphrodite was covered with a thin Skin, but had no Præputium, _&c._’ From which Words it is obvious, what was the Sex of this Subject, without any further Observations on it. EXPLANATION OF TAB. I. [Illustration: Tab. I.] As Dr _Douglas_’s Plate only shews the _Labia_ of the Parts of the _Angolan_ Woman opened, it was necessary that a Figure of the same should precede it with the _Labia_ shut or closed; that the Reader may the better understand, how easily the ignorant or superstitious might be deceived at the Sight of such Parts, when in the same Circumstances with this Subject, and the _Labia Pudendorum_ not separated; of which the following is the Explanation, _viz._ 1. The _Clitoris_. 2. The Right _Labium_, which contains the Tumour. 3. The Left _Labium_ in a natural State. 4. The Tumour above the Left _Labium_. 5. The two _Labia_ below the Tumour near the _Perinæum_. _FINIS._ FOOTNOTES [1] Mechanical Account of Poisons, _Pref._ [2] Democrit. in Geoponicis. l. 19. c. 4. Brodæus com. in Oppian. de venatione. Bodinus. [3] Montan. lib. de differ. animalium. p. 34. ex Oppian. l. 2. de venat. Brodæus, &c. [4] Basil. mag. problem. 58. Ælian. lib. 2. animal. 46. [5] Aristot. Rhodigin. l. 15. c. 10. Bodinus. Cardanus. [6] Myolog. comp. cum aliis plurimis operibus. [7] Anatomy of human Bodies. [8] Compend. Anatomic. [9] Osteogen. [10] Mechanical Essay upon Poisons. _Idem_, A short Discourse concerning Pestilential Contagion. [11] De Structur. & mot. Musculari. [12] Eutrop. Hist. Roman. 1. 4. Obseq. c. 56. [13] _Jac. le Moyne de Morgue_’s Voyages. He followed _Laudonnerius_ in his _American_ Voyage. [14] Decemviri. [15] Tit. Liv. Tom. II. l. xxvii. c. xxxvii. C. Claud. M. Liv. II. Coss. _Ibid._ Tom. III. l. xxxi. c. xii. P. Sulp. II. C. Aurel. Coss. Ante omnia, abominati femimares, jussique in mare ex templo deportari. [16] Lib. 4. c. 25. de Vita Constant. Imp. [17] ‘Τοῖς δὲ κατ’ Αἴγυπτον αὐτήν τε τὴν Ἀλεξάνδρειαν, τὸν παρ’ αὐτοῖς ποταμὸν δι’ ἀνδρῶν ἐκτεθηλυμένων θεραπεύειν ἔθος ἔχουσι νόμος ἄλλος κατεπέμπετο, πᾶν τὸ τῶν ἀνδρογύνων γένος ὥσπέρ τι κίβδηλον ἀφανὲς γίγνεσθαι τοῦ βίου· μὴ δ’ ἐξειναί ποι ὁρᾶσθαι τοῖς τὴν ἀσέλγειαν ταύτην νενοσηκότας.’ [18] Lib. 1. de Hermaphr. c. 39, 40. [19] De Hermaphroditorum apud Judæos Jure. ‘Androgynorum in Jure Hebraico frequens mentio est, etsi de causis confusæ in ipsis naturæ non admodum sunt solliciti. Nam simplicissime scribunt Androgynum (hæc vox ipsis familiaris est) esse, in quo utriusque sexus membra genitalia sint, quorum unum tamen altero sit luxuriosius & potentius: hinc de jure eorum magis disputant, quod ex corpore juris ipsorum, sive Talmud, transtulimus, verba ergo hæc habentur. ‘Androgynus sua natura partim similis est viris, partim mulieribus: partim viris & mulieribus, partim denique est propria persona, neque viris neque mulieribus similis. ‘I. Viris similis est, quinque modis juxta legem librorum Mosis: 1. Polluendo omnem hominem, omnemque rem, quam tangit, aut quæ ipsum tangit in illo tempore quo semen emittit, quemadmodum & viri modis omnibus polluunt secundum legem Mosis: 2. Quod tenentur in uxorem ducere fratris sui viduam relictam, quæ prolem ab ipso non habuit, uti ut viri secundum legem Mosis obstricti sunt: 3. Quod tenentur incedere vestitu à capite ad calcem more virorum, & pilos abradere more virorum, non mulierum, luxus gratia: 4. Quod illis permissum est mulierem in uxorem ducere, uti & aliis viris, & non nubere viro: 5. Quod tenentur observare præcepta omnia juxta legem Mosis, sicuti omnes viri Judæi observare tenentur: non autem sicuti mulieres, quæ non tenentur omnia Mosis præcepta observare, secundum ea quæ tempora requirunt. II. ‘Mulieribus autem similis reperitur septem modis secundum legem Mosis: 1. Similis est mulieribus polluendo omnem hominem, aliasque res, quas tangit, aut quæ ipsam tangunt, tempore menstrui, uti & menstruæ mulieres sanguinis fluxu laborant, & tunc polluit per omnia sicuti sexus mulieris secundum Mosis legem: 2. Quod illi non licet cum viro solus in gynæceo versari, aut in locis privatis: sicut ut mulieri secundum legem Mosis prohibitum est: 3. Quod illi concessum, in circuitu attondere angulum capitis sui more mulierum. Quia etiam illi permissum dissipare angulum barbæ suæ, quod tamen viris interdictum secundum legem Mosis: 4. Quod ei licitum est se cadaveribus polluere, & inter mortuos sepultos ambulare, uti & mulier, quod tamen viris inhibitum est secundum Mosis legem: 5. Quod ad testimonium exhibendum non est idoneus, sicut & sexus muliebris non idoneus existit, juxta legem Mosis: 6. Quod illi est prohibitus omnis illegitimus & illicitus concubitus ut & aliis mulieribus: 7. Quod vitiatur illicito concubitu, apud sacerdotes, (id est sacerdoti si nubat) qui sunt de semine Aaronis, ut & mulier vitiatur secundum legem Mosis. III. ‘Comparatur autem mulieribus & viris sex modis: 1. Percussus ab aliquo, cum illo transigere debet de damno ad summum æstimando a viris & mulieribus secundum legem Mosis: 2. Si contigeret ut aliquis illum imprudenter interimeret, occisorem recipere se opportet in unam civitatum securitatis causa ordinatarum, inque ea ad summi Pontificis obitum manere, non secus ac si virum aut mulierem imprudenter interfecisset, secundum legem Mosis. ‘Si vero ipsum malitiosè aut voluntariè interfecit, etiam ipse occisor mori debet, non secus atque si virum mulieremve interfecisset: 3. Mater pariens Androgynum in puerperio septem diebus immunda haberi debet, propter sexum virilem; rursus verò per alios septem dies pro immunda censeri debet propter sexum fæmineum: quindecem dies immunda censeri debet postquam peperit secundum leges Mosis (id est, numerare debet dies pollutionis ac purificationis, tanquam si filium & filiam genuisset): 4. Androgynus, si ex genere sacerdotali, etiam particeps fit sacrificiorum more aliorum virorum qui sunt ex sacerdotali genere, secundum Mosis legem: 5. Partem habet paternæ atque maternæ hæreditatis: in aliis quinetiam hæreditatibus jure ad illum spectantibus suam partem habet ac vir ac mulier, prout illi omnium optimè cedi potest. 6. Si quis dixerit, cupio ab omnibus rebus mundanis separari, tunc si Androgynus fuerit, in una parte tam masculini quam fæminini generis, debet hoc testari sufficienter, & separatus esse, secundum Mosis legem (id est Naziræatus voto tenetur). IV. ‘Similis denique neque viris neque mulieribus, sed propria persona existit tribus modis (sive nutrius sexus jus habet): 1. Licet Androgynus aliquem percutiat, vel calumnietur alium, tamen non tenetur satisfacere, secundum legem de viris & mulieribus: sed tanquam singularis persona est, debetque satisfacere secundum Judicium sententiam, aut quomodocunque transigere potest: 2. Si Androgynus votum nuncupaverit, secundum æstimationem personæ suæ Domino, & æstimationem de pretio personæ suæ Dei templo dedicaverit, si non æstimatus fuerit secundum expressam Mosis legem, sicuti viri & mulieres, tantum ut singularis persona secundum Judicium sacerdotis æstimetur, aut quomodocunque transigere potest cum iis qui Dei templo præsunt: 3. Si quis diceret cupio esse nuncupatus Deo, separatus ab omnibus rebus mundanis (sive obstringens se Naziræatus voto) tum si persona illa neque vir, neque mulier, verba ipsius pro nihilo habenda, neque Deo nuncupari debet: hæc ex Judæorum Talmud. ‘Rabbi Meir dixit: Androgynus est creatura per se ipsa ac specialis, neque voluerunt sapientes definire ac statuere, an vir, an mulier judicari deberet. Sed Obthurati alia ratio est: is enim quandoque vir, quandoque mulier est, prout natura in ipso nunc hoc, nunc illud membrum patefacit.’ [20] De Hermaphroditorum Juribus ex Jure tam Canonico, quam Civili. ‘De Hermaphroditorum apud Judæos juribus & privilegiis, ex ipso Talmud diximus; nunc paucis quæ ex jure tam canonico, quam civili, ipsimet excerpsimus, quæstiones proponemus, plura requirenti, ad ipsorum Jurisconsultorum scripta remittentes: qui hoc nobis (cujus nomine rogans) dabunt, cum & ipsi Dictatoris nostri Hippocratis testimoniis utantur. I. ‘Quæritur Hermaphroditus cum baptizatur, masculumne an fæmininum nomen imponendum sit? Resp. Nomen masculinum imponendum esse, si in sexu masculino magis incaleat, alias fæmininum. _Bald. in leg. quoties in fin. Ang. in l. de quib. de leg. Bertiachin. reper. par. 2. tit. Hermaph._ Vel in dubio incalescentis sexus, prout placet imponenti. _Bald. in l. quoties, num. 12._ II. ‘Quæritur, an & quoties confiteri debet? Resp. Debet confiteri semel in anno, sic ut homo masculus & fæminina. _Astaxen. in sum. decas. Boër. in c. omnis utriusque de pœnit. & remiss. Joh. de Por. in l. 2. in princ. de verb. oblig. Bertach. d. lex._ III. ‘Quæritur, an matrimonium contrahere possint? Resp. Quantum ad matrimonium contrahendum, secundum _Glos. in c. 3. q. 3._ Sexus magis incalescens: vel validior debet attendi, & sic judicari: & sit parilitas, debet stari dicto & electioni suæ: ita tenet _Bald. in l. quæritur ff. de statu hom._ Dicens hanc esse opinionem Guliel. quæ etiam rationalibus satis videatur. Sic & sum. Sylvestrina, _par. 1. pag. 485. tit. Hermaphrodit_. Et Fumus _in aur. armil. tit. Hermaph. n. 2_. Tiraquel. _Tom. 1. de jure primog. q. 17. op. 2. n. 15_. Hermaphroditus enim incalescens magis sexu masculino quam fæminino, judicatur ut masculus, _l. & quæsit. & ibi D. & Alex. de lib. & posthu. Bertash. dict. loc._ At in quo mulieris sexus prævaluerit, pro muliere habendus, Cynus _ad l. de quibus num. 9. ff. de l._ IV. ‘Quæritur an comprehendatur in statu requirente consensum propinquorum in contractibus mulierum? Resp. Tiraquel. quod non _gl. 5. n. 7_. His verbis: & hoc maxime procedunt in statutis, in quibus sub simplicibus mistum non continetur, ut probetur _in l. quid ergo §. 1. vers. ex Sentent. ff. de his qui not. infam. juncta l. 1. §. si is qui ff. de exer. utum. item si stat. dicat. ff. de just. & jure._ Ubi tenet statutum disponens in contractu mulierum requiri consensum propinquorum, non habere locum in mista persona, videlicet in Hermaphrod. per textum _in l. hoc legat ff. de l. 3_. V. ‘Quæritur an possit esse testis? negatur hoc _c. 3. q. 3._ item idonei _in gl. Scil._ Si magis vergat ad fæmineum vel etiam si sit parilitas: licet _in gl. non determinet_: Sed intellige, nisi in casu quo & mulier esse potest; _in sum. Sylv. part. 1. tit. Hermaph_. Specul. _de instru. ed. §. 11. v. quid si unus & tit. de t. §. 1. v. item quod est Herm._ Quod sic & mulier esse potest, non aliter per _c. Si test. §. Herm. 4. q. 3_. Sic Bart. _in trac. ad repr. testium in verbo juxta n. 56_. Reprobantur, inquit, Hermaphroditi, vel non compelluntur, sed qualitas sexus considerat _ut ff. de test. l. repet. & l. ex eo_. VI. ‘Quæritur an possit esse testis in testamento? Resp. Qualiter incalescentis sexus hoc ostendere, secundum Ulp. _in l. quæritur de sta. hom._ Hermaphrodit. igitur habens utrumque sexum, qui magis ad fæmineum declinat, non potest esse testis in testam. Sicut nec mulier, _Sec. gl. in c. si test. 4. q. 3_. Secus si magis ad masculinum vergit: si est paritas secundum Guil. censetur ut mulier, & ita non admittenda, nisi ut mulier, _sed d. gl._ non determinat fumus _in aur. arm. tit. Herm. Vide Spec. d. tit. inst. ed_. §. 12. _v. quod si unus. & tit. de te._ §. i. VII. ‘Quæritur utrum debeat stare in Judicio loco viri, vel mulieris? Resp. reg. Juris quod 1. debet jurare antequam admittat. Ad Judicium, quo membro possit uti, & secundum hoc admittendus, juxta usum & potentiam illius membri, & si uteretur ambobus membris æqualiter, tum secundum S. Ecclesiam non est tollerandus. VIII. ‘Ex quo etiam quæritur utrum possit promoveri ad sacros ordines? Et respons. Secundum jam dicta. Sic Hermaph. _est irregularis sec. Ant. Arctrie._ Florentinum _in 3. par. sum. tit. 18. de irregular. c. 6._ §. 5. Hermaphroditus repellitur à promotione propter deformitatem & monstrositatem, _arg. dist. 36. cap. illiteratus & 49 dist. cap. ult._ Talis si magis vergit in sexum masculinum, quam fæmininum: quamvis ordinari non debeat, nec ordinatus ministrare: tamen suscipit caracterem (_sum._ Sylvest. _par. 1. tit. Herm._ & Fumus _in aur. armil. tit. Hermaph. num. 2._) sed si magis vergit in sexum fæmininum quam masculinum, vel etiam si æqualiter participat de utroque, non est susceptivus caracteris, secundum Guil. multo magis fæmina, ordinis non est susceptiva quia non potest dici aliquis, vel aliqua. Idem sentit Astexanus _in sum. de casib. lib. 6. de sacram. ord. tit. 26._ & addit si magis vergat in sexum virilem, quam muliebrem, potest recipere caracterem: si è converso non potest. IX. ‘Possitne esse Rector Universitatis? Rector quippe non potest esse Clericus bigamus, nec Clericus uxoratus, nec Hermaphroditus, nec minor viginti annis. _Bald. in authent. habita pe. col. vers. item dico de clerico uxor. C. ne fil. pro pat. item Bertach. par. 3. repert. voc. Rector._ X. ‘Quæritur etiam num Judex esse possit? Et deciditur quod non, _arg. l. 12. ff. de jud. & cap. illiteratos dist._ 26. ubi Doctores. Hermaphroditus ponitur inter Infames c. infames 3. 4. 7. Jam vero famosis dignitatum portas non patere liquet, ex _l. 2. c. de dig. lib. 12. d. l. 12. §. 2. de jud. judicandi_, autem munus, quædam dignitas est & honor. _l. 1. privat. cap. 59. Extran. de appel. l. fin. c. quando provoc._ XI. ‘Quæritur, num possit esse Advocatus? Resp. Cum ponatur inter infames, non potest esse Advocatus. _3. q. 7. cap. infames §. in digestis._ XII. ‘Quæritur, num possit esse Arbitrator? Resp. Quod sic, sive judicetur tanquam fæminina, sive tanquam masculus, sive etiam æqualiter incalescat in sexu masculino sic ut in fæminino. Ita docet Bapt. de sanc. Blas. _in suo tract. de Arbitro & Arbitra in 6. prin. ver._ Sed quæro incidenter. Et ibi subdit, nunquid possit esse Arbiter, & concludit quod sic: si magis incalescit in sexu masculino, quam fæminino: alias secus, ut probatur in _l. quæritur ff. de statu hom. Bertachin. par. 2. reper. &c. hermusti_. XIII. ‘Quæritur etiam num Hermaphroditus incidat in pœnam, _l. si quis in tantum C. unde vi_, secundum Bart. _ibi ubi etiam Bald._ Item nota, quod magis incalens in sexu masculino, quam fæminino, inducatur ut masculus & _l. quæsitum_, & ibi Alex. _de lib. & posthu. & est tex. in l. quæritur de sta. hom._ Joh. Bap. Castel. Hermaphrodita enim per vim alterius possessionem occupans incidit in pœnam. _D. constitut. Bar. n. 14. pag. 355._ Monochius de _recupera. post. num. 9. ex l. si quis in tantum C. unde vi_. Cessat & hoc casu omnis disputatio de Hermaphrodito, quia sive in uno, sive in altero sexu incalescat magis, semper tamen in constitutione comprehenditur, ut scripsit hic. _Bart. n. 1._ Non enim est quod disputemus de potentiore sexu, juxta _l. quæritur de sta. hom._ quam declarat multis modis. _Dec. in rogasti in princ. n. 6. ff. si cert. pet. & cons. 213. n. 3. Alex. l. 2. in princ. num. 42. de verb. oblig._ Gomes Hisp. §. _quædam num. 45._ Instit. de act. & eodem loco de Actio. _in prin. n. 41._ Benev. Stracha _tract. de merc. 1. par. n. 58._ hæc Monochius. XIV. ‘Quæritur an Hermaphrodita possit prætendere ignorantiam constitutionis in _l. si quis in tantum c. vide en ff. de pœnis n. 5. Bart. in lectur._ XV. ‘Quæritur utrum Hermaphrodita succedat in feudum? Antiqua questio inquit. Bald. super, _cod. l. quoties n. 7. de suis & legit._ & determinatur quod sic, si magis incalescit in masculo, _ut ff. de sta. hom. t. quæritur ff. de lib. & posthum. l. sed est. quæsit. §. ultim. ff. de test. l. repet. §. 1. ita tenet. gl. ff. de leg. l. de quib._ & Jacob. de Domino Ardizone _in sum. sua_. Et ergo pro ista parte consului: quia si visis pudendis, quæ vilissima pars corporis nostri, non apparet major incalescentia, tamen si apparet in aliis operibus virtutis, ut in agilitate corporis, & præponderat in eo virilitas consului eum in feudo succedere: nec dicitur omnino imperfectus, qui similis est perfecto: quia ista imperfectio est occulta, quæ tegitur: perfectio autem est evidens & manifesta: ideo eligenda. ‘_L. de qui. & vide per gl. &_ Bald. _in l. 1. in fin._ quæ sit longa consue. _Ang. in d. l. de quib._ ubi quærit quid si magis non incalescit in uno quam in alio cui debeat comparari. ‘Vide etiam Baldum in §. omnium post _princ. inst. de actio. & cons. 237._ quidam magnificus, paulo ante finem, _lib. 3._ ubi dicit, quod statuta sive consuetudines feudorum deferentes feudum ad decendentes masculos, non includunt Hermaphroditum _per d. l. hoc legatum & alia quæ alligat. & Ang. cons. 256. quia consultatio. col. 2. ~Carneus~ cons. 137. viso instr. col. 3. n. 10. lib. 1. & recentior. in l. 2. in princ. ff. de verb. oblig. ~Vide~ ~Tiraq.~ gl. 5. l. 7._ ‘At Sichardus _in suis prælection. in rod. tit. 53. l. 8. ad l. 1. præses num. 7._ Si de consuetudine fæmina non potest succedere in feudo: ergo nec Hermaphroditus: quod intelligitur de eo, in quo incaluit, id est dominatur sexus muliebris. _Arg. l. quærit. ff. de sta. hom._ Ubi ejusmodi Hermaphrodita in quibus dominetur sexus muliebris, comparantur mulieribus: ut contra ii in quibus dominetur sexus virilis, comparantur masculis, nunc cum eadem sit ratio in Hermaphrodita fæmina, quæ est in pura fæmina, jure etiam tale jus erit in talibus Hermaphroditis statuendum. XVI. ‘Quæritur, qualiter debeat servire Hermaphrodita? Resp. Bald. _supra 6. cod. l. quoties n. 11._ Apparere duas conclusiones, sive opiniones in Hermaphrodita: una quod sufficiat servire taliter, qualiter potest, & non debeat servire per substitutum, ex quo admittitur ad fudum & hæc vera: _ut ff. de verb. oblig. l. continuus §. si ab eo._ _Q._ XVII. ‘Quæritur an Hermaphrodita possit in parte sua præeligere unum ex fratribus? Baldus _in l. fin. C. de suis & legit. n. 11. quod sic gratis, non autem pretio._ Hinc certum est, quod debeat decedere sive Hærede masculo: & si certum, ergo necessarium, quod pariter vocantur agnati in originali investitur, & ejus reliquiis ac appendiciis non potest derogari, _ut l. 3. ff. de interdict. & re. leg._ Nam quicquid ex aliqua radice descendit, necesse est ejus naturam sapere descendendo continuative & non adversative, _ut in cap. 1. de vasal. decre._ ‘Plura qui de Hermaphroditorum Juribus requirit, Dominos Doctores & Juris interpres consulat: Hæcque sufficiant circa Hermaphroditorum hominum naturam.’ [21] _Lib. 1. §. 1. fol. 8._ of _Fee Simple_. [22] ‘Hermaphrodita, tam Masculo, quam Fæminæ comparatur secundum prævalescentiam sexus incalescentis.’ [23] Lib. 1., De Divinatione, _parag._ 98. [24] And some that _Adam_ and _Eve_ were both Hermaphrodites. _Vid._ Nouv. Visionaires de Rotterdam. _Vid._ Casp. Bauhin. de Herm. l. 1. c. 34. in More Nevochim. _pag._ 2. c. 30. _Vid._ Heidegg. Hist. Patriarch. Tom. 1. pag. 128. Jus Talmud, Cod. Erwin. c. 2. Cod. Berachoth. c. 9. f. 61. Lib. Jalkut. f. 6. col. 4. [25] Simon Majel. Episc. Vulturanens, in colloq. 3. [26] Chap. XI. [27] The Author will endeavour to prove this in a short Treatise of Generation. [28] Estque hujus partis Chirurgia orientalibus tam necessaria quam decora. [29] _Albucas._ Chap. LXXI. de cura Tentiginis. [30] _Observationes Medicæ, Cap._ 35. p. 241. Habuit autem hæc Τριβας, naturalia sua, saltem quod ad externam faciem, haud aliter conformata ac aliæ mulieres. Sed intus percipiebatur evidenter (uti quidem testabantur tres obstretrices) paulo ante urinæ iter, Glandulosa aliqua caruncula, quam Clitoridem vocant Medici. Quæ licet in aliis feminis, vix unguis exprimat magnitudinem; dicebatur tamen in salaci hac fricatrice accedere ad longitudinem dimidiati digiti, & crastitudine sua haud male referre colem puerilem. [31] _Phil. Trans._ Numb. 32. p. 624. See _Badham_’s Abridgment. [32] An Expansion of the Furca Virginalis. [33] _Burnet_’s Travels, Letter from _Rome_, p. 203. _Montaign_’s Essays CXX. p. 97. Plin. l. 7. c. 4. Volaterran. Cardinalis. Pontanus. Jac. Duval Marcell. Donatus. Merula. Amat. Lusitanus cum, apud Skenckium, diversis aliis Historiis. [34] De Hermaph. & montrosor. part. natura, c. 33. [35] ‘Hæc ergo corpore erat satis procero, macilento tamen, voce virili, capillos longos habens, mentum lanugine obsitum, (pilos enim prodeuntes volsella evellere solebat) mammis carebat; pube erat piloso, pene longo, præputio denudato, & bene attrito; Scroto & testibus propendentibus carebat; sub pene in perinæo, ubi calculi extrahi consuevere, rima offerebatur oblonga, medium circiter digiti articulum profunda.... Hinc virum potius quam fæminam agnovimus. Interrogatus de venereis actubus, confessus se cum pluribus meretricibus, rem habuisse, & cum voluptate & cum seminis profusione; insuper quando vel rem haberet; vel solum incalesceret, penisve erigeretur, in inguine dextro testiculum protuberare (aliquando enim Testes in Scrotum non descendunt, sed in inguinibus subsistunt....) affirmavit; quod etiam tangendo persensimus; a sinistris vero nil unquam, nec extra, nec in conflictu venereo persensisse, nec etiam ex rima vulvam æmulante, quicquam unquam effluxisse. [36] _See_ Columbus _and_ Parée. [37] Lib. de monstris, Num. 32. [38] Ægineta, _ibid._ Gal. l. 14. de usu part. c. 1. C. c. 6. f. c. 10. h. a. & de Anatom. Administrat. Rhas. de Re Med. l. 1. c. XXVI. de forma uteri. _ibid._ Avicen. l. III. fen. XXI. de membris gener. in mulieribus c. 1. de Anatomia Matricis. [39] _King’s-Arms_ Tavern in _Fleetstreet_. This Account I had from that ingenious Surgeon Mr _John Douglas_. [40] Lib. 1. de Hermaph. c. XXXIII. [41] ‘Cum historia subsequens ad Hermaphroditorum naturam explicandam non parum faciat, eam ex Germanico sic reddidimus. [42] Lib. de human. natura, c. ult. [43] ‘Solet etiam in generatione, quibusdam viris illud muliebre membrum, & quibusdam fæminis illud virile membrum quo luxuriantur, adjici, sed impedita vel oblita natura, nam cum aliquo eventu impeditur vel obliviscitur, illud materiæ humidæ superfluum quod ad vastitatem, vel ad numerum alicujus membri solet disponere, ad alterius naturæ membrum sine ratione immittat.’ [44] Lib. III. Fen. XXI. Tract. 1. c. 12. de causis masculinitatis. [45] ‘Et dicunt quidem, quod si currit à dextro viri ad dextrum ipsius, masculinat: & ex duobus sinistris fæminat, & si currit ex sinistro ejus, ad dextram ipsius, erit fæmina Masculina, & ex dextro ejus, ad sinistram ipsius, erit Masculus fæmininus.’ [46] Galen de Sem. c. 5. h. ibid. c. 10. a. Hip. Aph. 48. l. 5. Galen l. 14. de us. par. c. 7. f. 9. Aris. 4. de gen. anim. c. 1. [47] ‘Ubi menses defluxerunt, sitque abstersus uterus, quod quinto sere die usu venit, aut septimo, si vir mulieri congrediatur, a primo cum est purgata, die, ad quintum, Marem produci; a quinto vero ad octavum, fæmellam: rursus ab octavo ad duodecimum denuo Masculum: post illum vero dierum numerum Hermaphroditum.’ [48] The Quotation in _Gerardus_’s Translation of _Avicen._ which is marginal, runs thus: Ras. 22. contin. 6. c. 1. 231. 2. Si mulier utitur coitu in die suæ levationis, concipit masculum; Si in quinto fæminam: Si in 6to masculum: Si in 7 fæminam: Si in 8. masculum: Si in 9. fæminam: Si in 10. masculum: Si in 11. utrum que Sexum. [49] ‘Et dixerunt quidam de illis, qui loquuntur absque ratione, quod pregnatio à die ablutionis, est cum masculo usque ad quintum, & est cum puella usque ad octavum: deinde est cum masculo usque ad XI. deinde est cum Hermaphrodito.’ [50] Lib. 3. de occul. natur. mir. c. 9. [51] ‘Primus enim diebus, elota vulva, humoreque sordido accurate expurgato, plus caloris concipit uterus, quo virile semen, potentius coalescit muliebri, atque in dextrum uteri sinum dirigitur, hepatis dextrique Renis vi attractoria, e quibus etiam sanguis calidus in alimentum futuri fœtus, iis diebus derivatur; neque enim sinistræ partes utpote alsiosæ ac frigidæ, sanguinisque inopes statim a purgatis mensibus aliquid conferre possint: sed serius ac partius sanguis depromitur a sinistræ partis venis, quas emulgentes vocant, quæ splenem renemque sinistrum perreptant, sicut post quinque demum diem usque ad octavum ex illis aliquid sanguinis confluat, quo fœtus alendus est, ita cum istæ partes vires suas obeant, censenturque dextræ ex situ loci, atque alimenti frigidi ratione femella effingitur; post octavum diem dextræ partes rursum conferendi sanguinis munus, sibi assumunt atque ex illis denuo scaturire sanguis incipit, masculum saginando. ‘Post hoc dierum curriculum, quoniam ex omni parte promiscue sanguis menstruus erumpit, ac vulva ex frigidi humoris affluxu plus satis uda efficitur, semenque nutri parti associatur; sed in media uteri capacitate fluctuat, Hermaphroditum confusa inter sesemina moliuntur, qui conceptus modo ex dextro, modo ex sinistro sinu vires formamque accipit atque utriusque opera utitur, hinc Androgyni nobis emergunt, sive Hermaphroditi.’ [52] L. 1. De occult. Nat. mir. [53] ‘In congressu quidem indecenti, nonnumquam vitiosus hic infamisque conceptus ex indecoro concubitu conflatur, cum præter usum ac commoditatem exercendæ veneris, vir supinus, mulier prona decumbit, &c.’ [54] De Gener. & part. humano, c. 10. ‘In muliere posteaquam virile semen receperit in utero, positura corporis observanda: Semper vitanda est quæ modo supino fit; quoniam maneat tunc semen in media parte uteri, non fit absolutus mas, nec fœmina, sed uterque simul, qui Hermaphroditus dicitur.’ [55] De Herm. p. 318. [56] ‘Fæmina virque simul veneris quum germina miscent, Venis informans diverso ex semine virtus Temperiem servans bene condita corpora fingit; Nam si virtutes permixto semine pugnent, Nec faciant uno permixto in corpore, diræ Nascentem gemino vexabunt corpore sexum.’ [57] Paraph. in Aristot. in 4. gen. animal. 4. [58] ‘Quæ autem genitalia gemina habent; maris unum fæminæ alterum, causa est ejusmodi generis.’ [59] In Com. de præcip. divin. gen. Tit. Tetrascopia sive lib. 15. [60] ‘Si perficiendis duobus, materia deficiat, uni tamen redundet; format vis διαπλαστικη, præter naturæ præscriptum, membra plura non necessaria.’ [61] ‘Hoc modo Hermaphroditi & Androgyni generantur, quibus membra sexus utriusque insunt; etsi, e duobus alterum fere imbecillum, atque inefficax; & contingit nonnunquam alterum mutari, vel prorsus aboleri.’ [62] Lib. 1. de reb. cœlestib. c. 6. [63] ‘Volunt autem calorem à quo existat generatio, moderatum illum quidem esse, & sua quadam certaque mensura contineri, urere autem, ac supra quam, generatio ipsa exigat, exsiccare, ubi vehementior fuerit, adversarique propterea generationi.’ [64] ‘Etsi è duobus, alter fere sit imbecillis,’ _&c._ [65] ‘Hæc igitur agens vis illa, & procreans, cum æquabiliter sese ad alterutrum habuerit, ut aut prorsus superet, aut ut rursus superetur, eodem, quidem aut virili, aut muliebri sexu fæminas nasci, at ubi partim vicerit, partim succubuerit, tunc in diversum, rem geri, atque alterum marem, alteram fæminam gigni.’ [66] ‘Natura in hominum omnino genere marem discernit à fæmina, itaque in eodem simul corpore uterque sexus, suo gradu, nequit consistere.’ [67] 2. Phys. Tr. 2. c. 3. de Animal. l. 18. [68] ‘Hermaphroditos fieri si qualitates contrariæ conjungantur quarum utraque sit complexionalis & terminans, & virtus formativa satisfacere potest utrique sexui, tam in membris exterioribus, quam in membris interioribus.’ [69] The Existence of these Cells is contradicted under _Domini Terrcellius_, which see. [70] Sanflorus in Thes. Aristot. l. 12. c. 3. [71] ‘Quia natura intendit semper generare masculum, & nunquam femellam, quia femella est vir occasione natus & monstrum in natura, quia aliquando generetur masculus quoad omnia membra principalia, sed tamen propter malam dispositionem Matricis, & objecti, & secundum seminis inæqualitatem, cum non possit perficere Masculum perfectum, sic generat femellam aut Hermaphroditem.’ [72] De Civit. Dei, l. 16. c. 8. [73] ‘Ex illo protoplasto uno originem ducere.’ [74] ‘Qualis autem ratio redditur de monstrosis apud nos hominum partubus, talis de monstrosis quibusdam gentibus reddi potest. Deus enim creator est omnium, qui ubi & quando, creari quid oporteat, vel oportuerit ipse novit, _&c._’ [75] Aventures de _Jaques Sadeur_,—he fictitiously wrote that he was driven to _Terra Australis_, and that the Inhabitants were of both Sexes; see more of him in the General Diction. Tom. IX. p. 10. [76] ‘Androgyni, quos etiam Hermaphroditos nuncupant, quamvis admodum rari sint, difficile est tamen ut temporibus desint: in quibus sic uterque sexus apparet, ut ex quo potius debeant accipere nomen, incertum sit: à meliore tamen, hoc est, à masculino, ut appellarentur, loquendi consuetudo prævaluit; nam nemo unquam Androgynecas, aut Hermaphroditas nuncupavit.’ [77] Camerarius. Lonæus Bosc. Rhoderic. Acastro Cælius Rhod. Sabinus. Ptolomæus. Cardanus. Julius Firmicus, _jun._ [78] Epist. Medicinales diversor. l. 7. Epist. 2. Manardus delivers this as his own, in the Letter abovementioned; tho’ he has taken it from _Paulus Ægineta_, De re med. l. vi. C. LXIX. de Hermaphr. or from _Albucas_. in his Chirurgia C. LXX. de cura Hermafroditæ. [79] ‘Hermaphroditas Græci pariter & Latini appellant; quorum tres in viris differentiæ, una in mulieribus: In viris enim similitudo muliebris pudendi aliquando in scroto; aliquando in perinæo apparet; aliquando per medium scrotum urina exit. ‘In mulieribus supra pudendum, per pubem, virilis membri cum duobus testibus forma prominet.’ [80] Or else it is an accidental and superficial Chink, for which see _Columbus_ and _Parée_. [81] De Conceptu & Generatione Hominis, _&c._ l. 5. c. 3. fol. 44. [82] ‘Anno 1519. Tiguri Hermaphroditus vel Androgynus natus est, supra umbilicum egregiè formatus, sed circa umbilicum rubeam carnis massam habens sub qua membrum muliebre, & infra hoc, loco convenienti, virile quoque.’ [83] Ibidem c. 3. Artic. 14. [84] ‘Contigit nobis talem offerri infantem, de quo non satis constare cujusnam Sexus esset, prominebant quidem testiculi, membrum præterea nullum, infra testiculos ruptura erat unde urina efflueret, sed quia propter virgæ prominentis defectum (nec enim tota aberat, sed intro conversa, ad modo dictam rupturam deflectebat) hanc natura viam urinæ dedisset. Non pro femella, nec Androgyno, sed pro masculo hunc haberi & baptizari placuit.’ [85] ‘Cæterum quia quæ talia sunt, intellectu magis quam oculis percipiuntur, nec huic peculiarem figuram effingere voluimus.’ [86] Lib. XV. in fine. [87] ‘Duos deinde Hermaphroditos viventes consideravi in quibus alter mas, fæmina altera erat.’ [88] ‘Fæmina erat, Æthiopica mulier, earum quas cingaras appellant Longobardi, hæc neque agere neque pati poterat, nam uterque sexus illi imperfectus contigerat suo magno malo: Penis namque minimi digiti longitudinem crassitiemque non excedebat: Vulvæ autem foramen adeo angustum erat, ut minimi digiti apicem vix intromitteret: optabat misera ut illi hunc penem ferro evellerem, quippe qui sibi impedimento esse diceret, dum cum viro coire exoptabat. Optabat etiam ut vulvæ foramen illi amplificarem, ut viro ferendo idonea esset. Ego vero qui horum vasorum discrimen intueri fæpiùs cupiebam verbis detinui. Non enim sum ausus aggredi illius cupiditati satisfacere, quoniam id absque vitæ discrimine fieri non posse existimabam.’ [89] It is commonly call’d the Furcula or Frenula, which sometimes grows up almost to the Meatus Urinarius, differing from the Hymen imperforatum, inasmuch as the former rises from the Perinæum, but the latter is within the Orificium Vaginæ. [90] ‘Hermaphroditus vir quem vivum summa diligentia inspexi, hoc modo habebat: Penis adderat cum scroto, testibusque, sub quibus in pærinæo seu tauro, quo loco (inter Anum scilicet & Testes) fit sectio pro extrahendo vesicæ lapide, foramen quidem perstabat in Vulvæ morem, sed non penetrabat; atque hi sunt quos vidi Hermaphroditi.’ [91] ‘Les Hermaphrodites ou Androgynes sont des enfans qui naissent avec double membre genital, l’un masculin l’autre feminin et partant sont appelléz en notre langue françoise Hommes & Femmes.’ Les Oeuvres d’Ambroise Parée l. 25. c. vi. [92] ‘Or quant a la cause, c’est que la femme fournit autant de semence que l’homme proportionément, et pource la vertue formatrice, qui tousjours tasche a faire son semblable, a sçavoir, de la matrice masculine un masle, & de la feminine une femelle, fait qu’en un mesme corps sont trouvez quelque fois les deux sex, que l’on nomme Hermafrodites.’ [93] ‘Des quelles il y a quatre Differences, asçavoir, Hermafrodites masles, qui est celui qui a le sexe de l’homme perfaiet, et qui peut engendrer, et a au Perinæum un Trou en form de vulve toutes fois non penetrant au dedans du corps, et dicelui ne sorte Urine ny Semence.’ [94] The Slit in the Perinæum is taken from _Columb._ 1. xv. _ad finem_. [95] ‘La Femme Hermaphrodite, outre sa Vulve qui est bien composé, par la quelle elle jette la semence et ses mois, a une membre virile situé au dessus de la dite Vulve, pres le penil, sans præpuce: mais un peau deliée, la quelle ne se peut renverser ne retourner, et sans aucun erection, ê d’icelui ne sort Urine ny semence & ne s’y trouve vestige de Scrotum, ne testicules.’ [96] ‘Les Hermafrodites qui ne sont ny l’un ny l’autre, sont ceux qui sont du tout forclos; & exempt de generation, & leur sexe du tout imperfaict; & sont situez a costé l’un de l’autre, & quelquefois l’une dessus & l’autre dessous, & ne s’en peuvent servir, que pour jetter l’urine.’ [97] ‘Portraict d’un Hermafrodite homme & femme.’ [98] ‘Ni l’un ni l’autre.’ [99] ‘Hermafrodites masles & femelles ce sont ceux qui ont les deux sexes bien formez & s’en peuvent ayder & servir a la generation.’ [100] Histor. Anatomica Humani Corp. &c. 1. 8. Quest. XIV. de Monst. & Hermaph. [101] ‘Hermaphroditas ζιφυεις ανδροθήλυας αρσενοθηλιας vocant, in maribus id tribus sit modis; cum in perinæo seu interfemineo muliebre pudendum exiguum videtur; cum itidem in scroto, sed nullo excrementi profluvio, cum ibidem exeunte Lotio; in feminis unico, cum penis supra genitalis fastigium in clitorio & ima Pube prominet.’ [102] ‘Addunt quidem, in maribus cum supra Penis radicem muliebris natura extat.’ [103] ‘In fæminis cum penis ad Inguina vel in Perinæo profertur.’ [104] Enchiridium Anatomicum, 1. II. cap. XXXI. de partibus genitalibus. [105] Ibidem, cap. XXXVI. [106] ‘Ad Urethram & Scrotum pertinent Hermaphroditæ, si absconditi fuerint intra septum Peritonæi Testiculi, & Scrotum inane fuerit, vel media sui parte apertum, ex Urethra ibi perforata cum Scroti Latera, uteri labra æmulantur: Penis adeo exiguus ut Obstetrices imperitas ista deceperint quæ tales Fœtus nascentes, in Ortu suo Judicarent femellas.’ [107] ‘Tales judicati pro feminis tandem Mares evadunt, verum nunquam visa est fæmina in Marem conversa nisi abutatur sua Clitoride prolongata, vel Hypersarcosis erumpat ex utero, quæ penis formam & duritiem æmulatur, sed Penis compositionem nullo modo præ se sert, &c.’ [108] ‘Clitoris prolongatur supra modum, mentiturque penem virilem, Κέρκοσις Cauda dicitur ita ut mulieres ista parte productiore & crastiore abutantur inter se, tales sunt quæ dicuntur Hermaphroditæ sive fricatrices, nec unquam visa est, & impossibile est mulierem in virum transformari. Sed mas in exortu suo pro femina habitus ut dictum est, erumpentibus partibus genitalibus, quæ intus latebant potest in virum degenerare.’ [109] ‘Hanc tamen naturæ fraudem detexit post mortem accurata harum partium dissectio,’ _Opera omnia_, Cap. III. [110] Ibidem, Cap. XV. [111] ‘Non virile membrum esse, at Muliebre, clitoridis nomine notum asseruimus tantoque liberius, &c.’ [112] Anatome Corp. Humani, cap. xxiii. p. 223. [113] ‘Nuper mulier quædam non infimæ fortis mihi conquesta est, se in prima juventute libidinis stimulos sentientem, sæpissime istam particulam digito fricare, sicque Semen sibi summa cum voluptate provocare solitam fuisse; sed progressu temporis hanc malam consuetudinem in morbum abiisse, &c.’ [114] Anat. Corp. Humani, c. 25. [115] ‘In Hermaphroditis hæc ipsa pars est quæ increscens virgam virilem effingit, ut ex eo patet, quod nulla manifeste conspicua perforatio in ea observetur.’ [116] ‘Huic superiori pudendi parte Clitoris excreverat ad medii digiti Longitudinem, & mentulæ Crassitiem, cum glande, frenulo & præputio, ut in viris esse solet, excepto quod fissura glandis non esset manifeste pervia: inferius meatus urinarius, & vagina uteri adstabant, ut in mulieribus: in singulis pudendi labiis unus testis continebatur.’ [117] ‘Similem etiam Hermaphroditum Anglum ætatis 22 annorum, anno 1668, cum plurimis aliis spectatoribus, vidimus hic Ultrajecti, &c.’ [118] ‘Ex quibus omnibus satis patet, hujusmodi Hermaphroditos non vere utriusque sexus participes esse, sed esse revera fæminas quibus genitalia sunt male conformata, scilicet Testes extra abdomen in labia descenderunt, & clitoris in nimiam longitudinem increvit.’ [119] Anatomes, lib. I. cap. XXV. de uteri partibus, Vid. Edit. Ultrajecti 1685. pag. 154. ‘Ex quibus omnibus satis patet, hujusmodi Hermaphroditos non esse vere utriusque sexus participes, sed esse revera fæminas, quibus genitalia sunt male conformata, scilicet Testes extra abdomen in labia descenderunt, & Clitoris in nimiam longitudinem increvit.’ [120] ‘Superioribus etenim annis fæminam mihi videre contigit, quæ præter vulvam membro quoque virili prædita erat, quod tamen non erat admodum crassum.’ _See the foregoing Chapter._ [121] ‘Uterus autem, nec non uteri cervix à cæterarum fæminarum matrice colloque nihil distabat: sed in testibus discrimen erat: nam testes in hac crassiores erant, quam in reliquis mulieribus: sed quoad situm ipsorum, nullum discrimen deprehendi. Peni Scrotum contiguum non erat, imo vero scroto prorsus carebat, & duobus musculis præditus erat hujus fæminæ penis, non quatuor, ut in maribus perfectis, præterea penis hujus hermaphroditi tenui pelle integebatur, nullum aderat præputium, _&c._’	39,703	common-pile/project_gutenberg_filtered	71304	project gutenberg	project_gutenberg-dolma-0013.json.gz:2514	https://www.gutenberg.org/ebooks/71304.txt.utf-8
EtkuoJhm_D9vANS0	15.4: Textbook Completing Checklist	15.4: Textbook Completing Checklist Content 1: Accessibility Checker Run the Accessibility Checker over each page to check for major accessibility issues. This is accessed via the black Vitruvian Man icon on the editor toolbar (far right): Select "All accessibility Issues" and address concerns as needed. 2: Summary II Write a short (or longish) summary paragraph that is pasted to the top page. This text doesn't show up in the printed version, but provides a valuable overview to faculty and students when loading your text. This is best forumulated to address: (1) the target course(s) of the text, (2) the target audience, e.g., lower divisional, introductory etc., (3) specific flavors/emphasis of the text e.g., if the text has a cultural responsive or localized focus. It isn't needed to add authors to this summary since that is covered by the branding bar and attribution footer. 3: Bots While this part of the publishing and compiling process, authors can request bots to run over existing page on a book at any time. The standard bot is the "Bradbot" named after Brad Pitt, which is so named since the bot "prettifies" the page by standardizing underlying code that may be difficult to establish manually. Meta Data 1: Summary II Rewrite the summary from above into the "summary" block under the "page settings" (you may need to expand it). This has a limited amount of text (about three lines) that is about the size of a tweet (280 characters). This summary will show up in searches for books, also is used for the Commons catalog entry for the text after being compiled and it also shows up on the back of physical copies of the text. Licensing Issues 1: Check Licensing When the PDF is generated (Via the PDF button), a licensing map will be general that shows authors a detailed list of applicable licensing at each page. Find the pages that are labeled as "undeclared" and change those pages to the appropriate license (in the page settings).	432	common-pile/libretexts_filtered	https://chem.libretexts.org/Courses/Remixer_University/Construction_Guide_for_LibreTexts_2e/15%3A_Styles_Standards_and_Typesetting/15.04%3A_Textbook_Completing_Checklist	libretexts	libretexts-0000.json.gz:31903	https://chem.libretexts.org/Courses/Remixer_University/Construction_Guide_for_LibreTexts_2e/15%3A_Styles_Standards_and_Typesetting/15.04%3A_Textbook_Completing_Checklist
xKXr3R_3tx_Bsdh7	Hydron blue pat. and hydron violet pat. printed on cotton / Cassella Color Company.	and with specially good levelling properties. They are dyed with hydrosulphite, some of them also with sodium sulphide and hydrosulphite, with the addition of caustic soda lye. The caustic soda lye may be replaced by soda in some cases. Vessels of wood, copper, iron or nickeline are used when dyeing with hydrosulphite, but when sodium sulphide is added, vessels and fittings made of copper or brass must be avoided. DISSOLVING THE HYDRON COLOURS. Paste Products : The Ilydron Blue and Violet brands in paste form maybe added straight to the dyebath. The dyestulf mixed with warm water is added to the warm bath together with the requisite quantities of alkali, whereupon the sodium sulphide and hydrosulphite are added whilst stirring, as described in full in the following dyeing directions. After the addition of the hydrosulphite the dyestuff dissolves rapidly. Hydron Yellow Paste and Hydron Olive Paste are diluted with about 5 to 10 times their weight of water free from lime, then reduced and dissolved by the addition of the quantity of hydrosulphite and lye requisite for the dyeing. Powder Products: The dyestuff is mixed to an even paste with about onehalf or the same quantity of cold to lukewarm water free from lime; there should further be added about 1j2 gallon methylated spirits per 1 gallon water for the purpose of a quicker and more even mixing, especially in the case of Hydron Blue and Hydron Violet. The paste thus obtained is diluted with about 10 times its weight of cold water. The Hydron Blues and Hydron Olives may then be added straightaway to the dyebath; the other powder products, however, after having been made into a paste, are mixed with the quantity of hydrosulphite and caustic soda lye necessary for dyeing, and thus brought into solution. first bleach the yarn. For the dyeing, ordinary dye-vats or tubs of wood, copper or iron are used, but when dyeing Hydron Blue according to the most frequently followed method with sodium sulphide, copper vessels cannot be used. For heating the liquor, indirect steam is best used, and it is advisable to adjust a double set of pipes, as described on page 66 of our “Manual of Dyeing”, Yol. I, 2nd edition. To ensure level shades it is very essential that the yarns after the dyeing are squeezed off well. This is best carried out by means of squeezing rollers adjusted at the narrow end of the vat. An exact sketch and description will be found on page 67 of our “Manual of Dyeing”, Yol. I, 2nd edition. A great advantage is to dye on the well-known bent iron rods of this shape ~ Lf by means of which the yarn can be kept continually under the surface of the liquor; greater levelness is thus ensured and at the same time an economising of hydrosulphite, which latter decomposes quickly when exposed to the atmosphere. Straight sticks may also be used, but the yarn must be turned more frequently or best be kept under the surface of the liquor; the quantily of hydrosulphite should then also be slightly increased. Before lifting, the batch is given three more turns, then each individual stick again a few turns, squeezing it off directly and bringing it in most cases straightaway into a rinsing bath ready at hand. Rinse first cold and then once or twice hot. In order to ensure greater brightness of shade in the case of Hydron Yellow, its dyeings are to advantage wrung off, after squeezing off, exposed to the air for 1 to 2 hours, and only then rinsed. Mercerised Cotton Yarn is dyed and aftertreated exactly like ordinary cotton yarn. As it however absorbs the dyestuff much more rapidly than ordinary yarn, it is advisable in every case to add to the bath some monosolvol or Turkey-red oil, for lighter shades also increasing the quantities of hydrosulphite and caustic slowly. The sodium sulphide process has proved especially useful for dyeing with Hydron Blue and Hydron Violet yarns which are very tightly twisted and difficult to penetiate; the material is first boiled for 1/ 4 to lj2 hour without adding any hydrosulphite, i. e. with only the dyestuff, sodium sulphide and caustic soda lye or soda, whereupon the bath is cooled off to 60 — 70 0 C. (140 — 160 °F.), the hydrosulphite strewed in and dyeing completed within »/« hour. Dye the previously well boiled or bleached cotton yarn for 1 ; 2 to 3,4 hour at 50— 60 °C. (120— 140° F.), to best advantage on bent iron rods, squeeze off, rinse first cold and then if possible once or twice hot. Also when aftertreating with bichrome, or bichrome and bisulphite, or by soaping boiling hot, somewhat brighter shades are obtained. By an aftertreatment with copper sulphate and bichrome the already excellent fastness to boiling and light is still further enhanced. Fuller details regarding the aftertreatment will be found on page 11. The dyebath must have a completely yellow appearance, until, the dyeing has been completed; if this is not the case, some more hydrosulphite and if necessary also a little more lye must be added. This process comes chiefly into consideration for medium and deep shades, but may to advantage be employed also for light shades, particularly on material difficult to penetrate such as mercerised embroidery yarns (pearl yarns). For this method of dyeing a smaller quantity of hydrosulphite is required than for the first-named process (a); this results in the cost of dyeing being reduced considerably. The following quantities are used: Dye and aftertreat according to the details on the previous page. Until the dyeing is completed, the dyebath must have a yellow appearance; if not, some hydrosulphite and if necessary some soda lye should be added. Hydron Violet B and R Powder are dyed according to Directions (a) and (b) as afore indicated for Hydron Blue. 'When dyeing with sodium sulphide, somewhat more hydrosulphite is required than is stated for Hydron Blue. Hydron Dark Blue Q Powder. Hydron Dark Blue G may be dyed with caustic soda lye and hydrosulphite, or with caustic soda lye, sodium sulphide and hydrosulphite. The quantity of caustic soda lye should however be somewhat increased. For the 20% paste product about the same weight should be used as of dyestuff for the starting baths, for subsequent lots 1/ 2 to /4 the quantity of caustic soda lye, calculated on the weight of the dyestuff (20% paste), is sufficient. Add the dyestuff reduced according to the directions on page 4 at 30 — 40° C. (85— 105° F.) together with the above indicated quantities of hydrosulphite and lye to the bath already charged with a small quantity of these two ingredients, then the common salt in solution; hereafter dye for ^2 to 1 hour in a cold to lukewarm bath, squeeze off when the dyeing is complete, wring off evenly, expose to the air for 1 to 2 hours, and rinse. Add the dyestuff reduced according to the directions on page 4 at 70 — 80 °C. (160 — 175° F.) with the above indicated quantities of hydrosulphite and lye to the warm bath previously charged with small quantities of these two ingredients, stir well,' and dye^ Hydron Olive at 50 — 60 °C. (120 — 140 °F.), Hydron Brown at 40 — 50° C. (105 — 120° F.), for 1/2 to 1 hour, squeeze off, and rinse. In the case of Hydron Brown somewhat more reddish shades are obtained by soaping boiling hot. with Hydron Yellow. The products are reduced, to best advantage each separately, with the quantities of hydrosulphite and lye indicated, and dissolved. Then dye for V2 to s/4 hour at 35— 40° C. (95 — 105 °F.), squeeze off, rinse, and soap if necessary. Hydron Olive and Hydron Brown are reduced each separately with the quantities of hydrosulphite and lye prescribed for each, and dissolved, whereupon they are added to the dyebath at about 50° C. (120° F.) Hereafter add the quantities of dissolving agent required for Hydron Blue, and finally the Hydron Blue itself. Combinations of Hydron Blue and Hydron Yellow. Charge the dyebath at about 40 °C. (105 0 F.) with Hydron Blue and the weights of dissolving agents indicated on pages 6 and 7, then with the Hydron Yellow dissolved with the requisite quantities of hydrosulphite and lye. Dye for /2 to 1 hour at about 40 0 C. (105 °F.), squeeze off, and rinse; for deeper shades add some common salt or Glauber’s salt in order to make the Yellow go more readily on to the fibre. For combinations with a larger proportion of Hydron Blue it is better to dye the yarn in the first place with Hydron Blue in the ordinary manner and after rinsing to top with Hydron Yellow in a second, cold bath. Hydron Blue or Hydron Dark Blue Q. Blacks of good fastness to chlorine may be produced in a very simple manner with Hydron Blue or Hydron Dark Blue, by simply bottoming with these dyestuffs and topping with Aniline Black in a fresh bath. This method is suitable more particularly for hank and loose cotton dyeing. The bottoming is done with about 15—20% Hydron Blue G or R Paste 20%, or Hydron Dark Blue G Paste 20%, according to Method (b) on page 7. After rinsing thoroughly, the topping with Aniline Black is carried out as follows: Hydron Blue on an Iron Mordant. A very deep coppery blue such as is not obtainable by dyeing direct without an excessive amount of dyestuff may be produced by previously mordanting the cotton with iron salts and dyeing subsequently with Hydron Blue. Such shades of blue equal entirely deep Indigo shades, at the same time far excelling them in properties of fastness. The method of working is as follows: The boiled cotton is treated for about 20 minutes with about 1 lb copperas per 10 gallons or with a solution of pyrolignite of iron or nitrate of iron 2 — 4 ® Tvv. in a cold bath to which some acetic or formic acid is to advantage added. The goods are then wrung off or whizzed. Hereafter they are entered into a lukewarm bath containing 1 — D/2 lbs soda ash per 10 gallons, and treated for about 10 minutes. After rinsing thoroughly, they are then dyed with Hydron Blue, to best advantage with soda lye or soda and hydrosulphite according to the directions on page 6. Hydron Dark Blue G is the product best suited. For this purpose Immedial Colours may however also be used, of which Immedial Black V extra, Immedial Brilliant Black 5BV cone., Immedial Brilliant Carbon F and Indo Carbon S deserve the preference; these are dissolved in the customary manner with sodium sulphide, and may be added straight to the Hydron Blue bath. The dyeing in such case is best carried out according to the sodium sulphide-hydrosulphite process, carbonate of soda being to advantage used for the purpose instead of caustic soda lye. Indigo and Hydron Blue may be dyed together in one bath, but in such case it is an advantage to work at a somewhat lower temperature, say at about 40° C. (105° F.j. The fact has moreover to be considered that /< to 4/& of the Indigo remains in the bath, whereas of Hydron Blue the greater portion is taken up by the fibre. When using fairly large quantities of Indigo it is therefore best to bottom with Hydron Blue and to top in a fresh bath with Indigo. Treatment of Hydron Colours after the Dyeing and Rinsing. As a rule a special aftertreatment of the dyeings produced with Hydron Colours is not required, but it must be made a point to give the dyeings a thorough rinsing or soaping finally, if possible hot. TREATMENT WITH EERBORATE. This aftertreatment comes into consideration for yarn, loose cotton, sliver, cops, cheeses, usurps and piece-goods. Considerably brighter shades are thereby obtained possessing the same excellent fastness as those which have not been aftertreated. again rinsed. The aftertreatment with a smaller quantity of perborate (about ij2%) in a warm bath of only 80—40° C. (85— 105 0 F.) is also in many cases applied in order to ensure a quicker oxidation, especially in machine-dyeing. TREATMENT WITH BICHROME AND BISULPHITE. This treatment has the same effect on the goods as bichrome and acetic acid, but the action is somewhat more vigorous. After the rinsing, 1/2- — 1% bichrome is added to the cold or warm bath, and allowed to act for some minutes, whereupon 3 — 6 oz bisulphite per 10 gallons are added to the same bath, the treatment being continued for some minutes. Finally the goods are thoroughly rinsed. By an aftertreatment with 3% copper sulphate, 1 — 2% bichrome and 3 — 5% acetic acid the already excellent fastness to boiling and light of Hydron Blue is still further enhanced. The treatment may be carried out in a warm or a cold bath, 5 to 15 minutes being quite sufficient for this purpose. The goods are finally rinsed thoroughly. respective shades on cotton yarn. It has however to be noted that the sodium sulphide process is employed to best advantage for dyeing Hydron Blue on loose cotton, because a previous wetting of the cotton can in such case be omitted. The bath in such case is first charged only with the caustic soda lye, or soda, sodium sulphide and dyestuff, the hydrosulphite being omitted until later. The opened cotton is then entered dry ,'into the boiling hot dyebath, and boiled for iJi to / 2 hour. Hereafter the bath is cooled off to about 70° C. (160° F.) by adding cold water, the hydrosulphite strewed in, and the dyeing completed within 1/j hour, the material being turned well. The dyeing being completed, the cotton is lifted, allowed to drain off well or hydroextracted, and rinsed thoroughly. If rinsed immediately after the draining off, the rinsing is done first cold and finally as hot as possible ; if the goods are hydroextracted, it is best to rinse Hot straightaway. For the other Hydron Colours it is well to wet out the cotton previously and then to dye at the temperatures indicated for cotton yarn. After the dyeing, the cotton is lifted, whizzed if necessary, and finally rinsed thoroughly. The dyeing is carried out in any kind of apparatus made of wood, iron, copper or nickeline, but for the sodium sulphide process as applied for Hydron Blue, apparatus or fittings of copper or brass should not be used. It is important also to provide apparatus for dyeing cops, cheeses, and warp-beams with good suction arrangements in order to ensure the liquor being drawn off quickly and thoroughly by suction after the dyeing. The goods are then rinsed well, this being carried out to best advantage warm to hot subsequent to the removal of the liquor by suction with a view to ensuring the highest degree of fastness. If a thorough removal of the liquor by suction is impossible, the goods are first rinsed cold, a little hydrosulphite and lye being added to the rinsing bath if necessary, and the goods being finally rinsed warm to hot also. ensured than with hard water. It is moreover absolutely necessary to boil the goods thoroughly before the dyeing, to advantage (when using soft water) with the addition of soda, Turkeyred oil or the like; if soft water is not being used, it is better to omit these ingredients. Dyeing of Warps in the Continuous Dyeing Machine. The .Hydron Colours also may be dyed to very good advantage in the various kinds of continuous dyeing machines which have to be provided with very efficient squeezing rollers. As a rule the dyebaths are charged in the same manner as stated for cotton yarn ; all that has to be considered is that the starting baths, on account of the shorter duration of the dyeing operation, must be correspondingly stronger. also be slightly reduced. For dyeing very hard material, the sodium sulphide process is particularly well suited for Hydron Blue; boil the yarn with the dyestuff, caustic soda lye or soda and sodium sulphide without any hydrosulphite, the hydrosulphite being added to the cooled bath after about /2 hour, and dye for another half hour or so. For certain styles, more particularly for shirtings, unbleached yarn is woven up with dyed yarn, the fabric being then bleached in the piece. There are only few dyestuffs which will withstand this operation, and even with these, special precautions have to be taken in the bleaching. Pieces containing yarn dyed with Hydron Colours are treated as follows: Boil the pieces for about one hour in a jigger containing 4 — 8 oz Turkey red oil or monosolvol per 10 gallons, rinse, then bleach for a few hours in the customary manner with hypochlorite of soda of /4 — 1 0 Tw., rinse, acidify, and rinse once more thoroughly. Sodium hypochlorite is prepared as follows: 100 lbs of chloride of lime 33% are rubbed down with cold water to 40 gallons, and 60 lbs of soda ash are dissolved in 20 gallons of hot water, this solution being diluted with 10 gallons of cold water and added to the paste of chloride of lime. The mixture is stirred for */, hour and allowed to settle overnight. The clear solution is then drawn off and the precipitate washed four or five times with cold water, the wash water being used to dilute the solution to about 150 gallons of 6 — 7 0 Tw. It may be freed entirely from lime by the addition of 1 — 2 lbs soda ash, whereby the remainder of the lime is precipitated in the form of carbonate of lime. The solution reacts slightly alkaline. 0,35% ■Hydron Brown OG pat. Powder 0,35»/o Hydron Brown OB pat. Powder 0,08 o/0 Hydron Blue G pat. Paste 20 o/0 0,3 ®/o Hydron Brown OG pat. Powder 0,07 °/o Hydron Blue G pat. Paste 20»/o 0,05 o/o Hydron Yellow G pat. Paste 20 °/0 0,35 °/n Hydron Brown OG pat. Powder 0,35 °/o Hydron Blue R pat. Paste 20°/o 0,35<>/o Hydron Yellow G pat. Paste 20°/o 0,5 °/0 Hydron Blue G pat. Paste 20 % 0,13 o/0 Hydron Blue R pat. Paste 20% 0,13o/o Hydron Brown OG pat. Powder 0,5 0/0 Hydron Brown OG pat. Bowder 0,55o/o Hydron Blue R pat. Paste 20°/n 0,5 0/0 Hydron Yellow G pat. Paste 20% 0,35% Hydron Blue G pat. Paste 20% 0,07 °/0 Hydron Brown OG pat. Powder 0,07% Hydron Yellow G pat. Paste 20%	4,039	common-pile/pre_1929_books_filtered	hydronbluepathyd00cass	public_library	public_library_1929_dolma-0007.json.gz:4706	https://archive.org/download/hydronbluepathyd00cass/hydronbluepathyd00cass_djvu.txt
fLcyiZXNgqEp20a0	Communication Essentials for Business	1.4 Case Studies: The Cost of Poor Communication No one knows exactly how much poor communication costs businesses, industries and governments each year, but estimates suggest billions. In fact, a recent estimate claims that the cost in the U.S. alone is close to $4 billion annually (Bernoff, 2016). Poorly worded or inefficient emails, careless reading or listening to instructions, documents that go unread due to poor design, hastily presenting inaccurate information, and sloppy proofreading — all of these examples result in inevitable costs. The problem is that these costs aren’t usually included on the corporate balance sheet at the end of each year, so often the problem remains unsolved. (What is the Cost of Poor Communication, 2022) Knowledge Check You may have seen the Project Management Tree Cartoon before (Figure 1.4.1); it has been used and adapted widely to illustrate the perils of poor communication during a project. The waste caused by imprecisely worded regulations or instructions, confusing emails, long-winded memos, ambiguously written contracts, and other examples of poor communication is not as easily identified as the losses caused by a failed proposal. But the losses are just as real — in reduced productivity, inefficiency, and lost business. In more personal terms, the losses are measured in wasted time, work, money, and ultimately, professional recognition. In extreme cases, losses can be measured in legal damages, stock losses, and even company closures. The following “case studies” show how poor communications can have real-world costs and consequences. For example, consider the “Comma Quirk” in the Rogers contract that cost $2 million (Robertson, 2006). Also, check out how a small error in spelling a company name cost £8.8 million (The Guardian, 2015). Or examine Tufte’s discussion (.pdf) of the failed PowerPoint presentation that attempted to prevent the Columbia Space Shuttle disaster (2001). Or you might want to read about how the failure of project managers and engineers to communicate effectively resulted in the deadly Hyatt Regency walkway collapse (McFadden, 2017). The case studies below offer a few more examples that might be less extreme, but much more common. Knowledge Check Review the Case Study 1 and 2 below. Answer the questions that follow each case study. Exercises adapted from T.M. Georges’ Analytical Writing for Science and Technology (1996). CASE 1: The promising chemist who buried his results Bruce, a research chemist for a major petrochemical company, wrote a dense report about some new compounds he had synthesized in the laboratory from oil-refining by-products. The bulk of the report consisted of tables listing their chemical and physical properties, diagrams of their molecular structure, chemical formulas and computer printouts of toxicity tests. Buried at the end of the report was casual speculation that one of the compounds might be a particularly effective insecticide. Seven years later, the same oil company launched a major research program to find more effective but environmentally safe insecticides. After six months of research, someone uncovered Bruce’s report and his toxicity tests. A few hours of further testing confirmed that one of Bruce’s compounds was the safe, economical insecticide they had been looking for. Unfortunately, Bruce had since left the company because he felt that the importance of his research was not being appreciated. CASE 2: The unaccepted current regulator proposal The Acme Electric Company worked day and night to develop a new current regulator designed to cut the electric power consumption in aluminum plants by 35%. They knew that, although the competition was fierce, their regulator could be produced more cheaply, was more reliable, and worked more efficiently than the competitors’ products. The owner, eager to capture the market, personally but somewhat hastily put together a 120-page proposal and sent it to the three major aluminum manufacturers, recommending that their regulators be installed at all company plants. She devoted the first 87 pages of the proposal to the mathematical theory and engineering design behind this new regulator, and the next 32 to descriptions of the new assembly line she planned to set up to produce regulators quickly. Buried in an appendix were the test results that compared her regulator’s performance with present models, and a poorly drawn graph showed how much the dollar savings would be. Acme Electric didn’t get the contracts, despite having the best product. Six months later, the company filed for bankruptcy. In small groups, examine a selection of two or three “cases” listed below and determine the following: - Define the rhetorical situation: Who is communicating to whom about what, how, and why? What was the goal of the communication in each case? - Identify the communication error (poor task or audience analysis? Use of inappropriate language or style? Poor organization or formatting of information? Other?) - Explain what costs/losses were incurred by this problem. - Identify possible solutions or strategies that would have prevented the problem, and what benefits would be derived from implementing solutions or preventing the problem. Present your findings in a brief, informal presentation to the class. Exercises adapted from the Maruka Centre for Applied Ethics and T.M. Georges’ Analytical Writing for Science and Technology (1996). See more case studies for discussion below. CASE 3: The instruction manual that scared customers away As one of the first to enter the field of office automation, Sagatec Software, Inc. had built a reputation for designing high-quality and user-friendly database and accounting programs for business and industry. When they decided to enter the word-processing market, their engineers designed an effective, versatile, and powerful program that Sagatec felt sure would outperform any competitor. To be sure that their new word-processing program was accurately documented, Sagatec asked the senior program designer to supervise the writing of the instruction manual. The result was a thorough, accurate and precise description of every detail of the program’s operation. When Sagatec began marketing its new word processor, cries for help flooded in from office workers who were so confused by the massive manual that they couldn’t even find out how to get started. Then several business journals reviewed the program and judged it “too complicated” and “difficult to learn.” After an impressive start, sales of the new word-processing program plummeted. Sagatec eventually put out a new, clearly written training guide that led new users step by step through introductory exercises and told them how to find commands quickly. But the rewrite cost Sagatec $350,000, a year’s lead in the market, and its reputation for producing easy-to-use business software. CASE 4: One garbled memo – 26 baffled phone calls Joanne supervised 36 professionals in 6 city libraries. To cut the costs of unnecessary overtime, she issued this one-sentence memo to her staff: After the 36 copies were sent out, Joanne’s office received 26 phone calls asking what the memo meant. What the 10 people who didn’t call about the memo thought is uncertain. It took a week to clarify the new policy. CASE 5: The co-op student who mixed up genres Chris was simultaneously enrolled in a university writing course and working as a co-op student at the Widget Manufacturing plant. As part of his co-op work experience, Chris shadowed his supervisor/mentor on a safety inspection of the plant, and was asked to write up the results of the inspection in a compliance memo. In the same week, Chris’s writing instructor assigned the class to write a narrative essay based on some personal experience. Chris, trying to be efficient, thought that the plant visit experience could provide the basis for his essay assignment as well. He wrote the essay first because he was used to writing essays and was pretty good at it. He had never even seen a compliance memo, much less written one, so was not as confident about that task. He began the essay like this: On June 1, 2018, I conducted a safety audit of the Widget Manufacturing plant in New City. The purpose of the audit was to ensure that all processes and activities in the plant adhere to safety and handling rules and policies outlined in the Workplace Safety Handbook and relevant government regulations. I was escorted on a 3-hour tour of the facility by… Chris finished the essay and submitted it to his writing instructor. He then revised the essay slightly, keeping the introduction the same, and submitted it to his co-op supervisor. He “aced” the essay, getting an A grade, but his supervisor told him that the report was unacceptable and would have to be rewritten – especially the beginning, which should have clearly indicated whether or not the plant was in compliance with safety regulations. Chris was aghast! He had never heard of putting the “conclusion” at the beginning. He missed the company softball game that Saturday so he could rewrite the report to the satisfaction of his supervisor. Review the video below for a few additional suggestions on improving workplace communication. (The Recipe for Great Communication, 2015) References Bernoff, J. (2016, October 16). Bad writing costs business billions. Daily Beast. https://www.thedailybeast.com/bad-writing-costs-businesses-billions?ref=scroll Georges, T. M. (1996). Analytical writing for science and technology. https://www.scribd.com/document/96822930/Analytical-Writing McFadden, C. (2017, July 4). Understanding the tragic Hyatt Regency walkway collapse. Interesting Engineering. https://interestingengineering.com/understanding-hyatt-regency-walkway-collapse Robertson, G. (2006, August 6). Comma quirk irks Rogers. Globe and Mail. https://www.theglobeandmail.com/report-on-business/comma-quirk-irks-rogers/article1101686/ Sagan, C. (1995). The demon-haunted world: science as a candle in the dark. New York, NY: Random House. The £8.8m typo: How one mistake killed a family business. (28 Jan. 2015). The Guardian. https://www.theguardian.com/law/shortcuts/2015/jan/28/typo-how-one-mistake-killed-a-family-business-taylor-and-sons The Colin James Method. (2022). What is the cost of poor communication [Video]. Youtube. https://www.youtube.com/watch?v=zTCXCpJ-CpU The Latimer Group. (2015). The recipe to great communication [Video]. Youtube. https://www.youtube.com/watch?v=qFWsTsvJ8Xw Tufte, E. (2001). The cognitive style of PowerPoint. https://www.inf.ed.ac.uk/teaching/courses/pi/2016_2017/phil/tufte-powerpoint.pdf Ward, J. (2019, July 8). The project management tree swing cartoon, past and present. TamingData. https://www.tamingdata.com/2010/07/08/the-project-management-tree-swing-cartoon-past-and-present/. 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jEmhQM6_jxCjnKyq	Humanities: Prehistory to the 15th Century	31 Cults The Imperial Cult The idea of deification of the emperor came during the time of Emperor Augustus. Upon his death, the Roman Senate rewarded him with deification which was an honor that would be bestowed upon many of his successors. Often, an emperor would request his predecessor to be deified. Of course, there were a few exceptions, notably, Tiberius, Caligula, Nero and Domitian, who were considered too abhorrent to receive the honor. Caligula and Nero believed themselves living gods while Domitian thought himself the reincarnation of Hercules. As Imperial cult developed over time, the worshipper would receive a libellus, or certificate of proof that certified that the worshipper had sacrificed to the Roman Emperor (more affectionately known as the “Son of God”). As the proliferation of private religions began to spring up throughout the Roman Empire promising personal salvation in exchange for fidelity to the cult, proof of sacrifice developed as a way to identify Roman citizens whose allegiance were not with the Roman state. (76) Private Cults Private religious cults — or “Mystery Religions” as they have come to be called — that appeared throughout the Roman Empire were often imported from areas taken over by the Roman state. As “foreign religions’ they gained in popularity because they offered a religious experience that was personalized, unlike the religion promoted by the Roman state. Indeed, whereas the religion of the state promised only solidarity at the level of citizenship, mystery faiths thrived because they provided a sense of solidarity between likeminded believers. That they often addressed individualized matters such as forgiveness, salvation, and personal identification with the Divine made them even more attractive to persons living in the Roman Empire. (1) Mithraism The Mithraic Mysteries, also known as Mithraism, were a mystery cult in the Roman world where followers worshipped the Indo-Iranian deity Mithras (Akkadian for “contract”) as the god of friendship, contract and order. The cult first appeared in the late 1 st century CE and, at an extraordinary pace, spread from the Italian Peninsula and border regions across the whole of the Roman empire. The cult, like many others, was a secret one. The most important element of the myth behind the Mithraic Mysteries was Mithras’ killing of a bull; this scene is also known as “tauroctony”. It was believed that from the death of the bull — an animal often seen as a symbol of strength and fertility — sprung new life. Rebirth was an essential idea in the myth of Mithraic Mysteries. The sacrifice of the bull established a new cosmic order and was also associated with the moon, which was also associated with fertility. What is special about the Mithraic Mysteries is its visuality. The sacrifice of the bull was depicted in a stone relief that had a central place in nearly every cult temple. In the relief, Mithras is often shown as he wrangles the bull to the ground and kills it. In a typical example, such as the celebrated sculpture from the Roman-Germanic Museum in Cologne, Mithras looks away from the dying bull, up to the moon. In addition, Mithras has a few helpers that assist him in taking the bull’s fertility: A dog and a snake drink from the bull’s blood, and a scorpion stings the bull’s scrotum. Also, a raven sits on the bull’s tail that typically ends in ears of grain. The raven could have played the role of a mediator between Mithras and the sun god Sol invictus, with whom Mithras will share the meat of the bull. The bull sacrifice relief was typically placed at the end of the temple, which was essentially built like a stretched-out Roman dining room — an aisle flanked by two broad, raised benches. However, the sacrifice of the bull was rarely enacted by the worshippers themselves. Worshippers did imitate how Mithras shared the bull’s meat with Sol, as fragments of dishes and bones of animals that have been found in these temples testify. High-quality pork, chicken and a large quantity of wine were consumed in high-spirited cultic feasts that connected the worshippers to each other and to Mithras. The Mithraic Mysteries were not just about fun and games, however. There were strict rules as to how the feasts were organised, for example, regarding hygiene. What is more, there were seven degrees of initiation, ranging from “corax” (raven) to “pater” (father), of which each had its own type of clothing. The other degrees were “nymphus” (bridegroom), “miles” (soldier), “leo” (lion), “perses” (Persian), and “heliodromus” (sun-runner). Each degree of initiation had a different task to fulfill, e.g. a “raven” had to carry the food, while the “lions” offered sacrifices to the “father”. Also, the initiates had to take part in tests of courage. The paintings in the temple of Mithras at Santa Maria Capua Vetere show us different scenes of this ritual. An initiate, blindfolded and naked, is led to the ceremony by an assistant. Later, the initiate has to kneel before the “father”, who holds a torch or a sword in his face. Finally, he is stretched out on the floor, as if he had died. This probably was a ritual “suicide” in which the initiate was “killed” with a non-lethal theatre-sword, and was then reborn. (77) Isis Cult Isis is an ancient Egyptian goddess, associated with the earlier goddess Hathor, who became the most popular and enduring of all the Egyptian deities. Her name comes from the Egyptian Eset, (“the seat”) which referred to her stability and also the throne of Egypt as she was considered the mother of every pharaoh through the king’s association with Horus, Isis’ son. Her name has also been interpreted as Queen of the Throne, and her original headdress was the empty throne of her murdered husband Osiris. Her symbols are the scorpion (who kept her safe when she was in hiding), the kite (a kind of falcon whose shape she assumed in bringing her husband back to life), the empty throne, and the sistrum. She is regularly portrayed as the selfless, giving, mother, wife, and protectress, who places other’s interests and well-being ahead of her own. She was also known as Weret-Kekau (“the Great Magic”) for her power and Mut-Netjer, “Mother of the Gods” but was known by many names depending on which role she was fulfilling at the moment. As the goddess who brought the yearly inundation of the Nile which fertilized the land she was Sati, for example, and as the goddess who created and preserved life she was Ankhet, and so on. In time, she became so popular that all gods were considered mere aspects of Isis and she was the only Egyptian deity worshiped by everyone in the country. She and her husband and son replaced the Theban Triad of Amon, Mut, and Khons, who had been the most popular trinity of gods in Egypt. Osiris, Isis, and Horus are referred to as the Abydos Triad. Her cult began in the Nile Delta and her most important sanctuary was there at the shrine of Behbeit El-Hagar, but worship of Isis eventually spread to all parts of Egypt. Both men and women served Isis as clergy and no doubt rituals concerning her worship were conducted along the lines of other deities: a temple was built as her earthly home which housed her statue and this image was reverently cared for by the priests and priestesses. The people of Egypt were encouraged to visit the temple to leave offerings and make supplications but no one except the high priest or priestess was allowed into the sanctuary where the statue of the goddess resided. Beyond this, however, little is known of the details of the rituals surrounding her worship. Like the Eleusinian Mysteries, the Cult of Isis grew into a Mystery Religion promising the secrets of life and death to initiates, who were then sworn to secrecy. It is known that the cult promised eternal life to those who were admitted to its secrets. The people who worshiped her throughout Egypt may or may not have been full initiates into her cult and, either way, left no record of how the goddess was honored. It was not until Isis was worshiped in Rome that people wrote about the cult to any great degree and by then it was clear that knowledge of the rituals involved was only for initiates. Her temple on the island of Philae in Upper Egypt would remain an active pilgrimage site for thousands of years until closed in the 6 th century CE by the Christian emperor Justinian. In her role as “throne goddess”, she was considered the mother of all kings, but her benevolence was not limited to royalty. Isis dominated the religious sensibilities of the people at the same time that Christianity was taking form through the evangelical missions of St. Paul c. 42â€“62 CE. The concept of the Dying and Reviving God which had long been established through the Osiris myth was now made manifest in the figure of the son of God, Jesus the Christ. In time, epithets for Isis became those for the Virgin Mary such as “Mother of God” and “Queen of Heaven” as the new religion drew on the power of the older belief to establish itself. The worship of Isis was the most stubborn of pagan beliefs to rival the new faith and continued longer than any other. (78) Bacchus Cult Dionysus (Roman name: Bacchus) was the ancient Greek god of wine, merriment, and theatre. Being the bad boy of Mt. Olympus, he was perhaps the most colorful of the Olympian Gods. In Greek mythology, despite being the son of Zeus and Semele (the daughter of Kadmos and Harmonia), Dionysus did not receive the best start in life when his mother died while still pregnant. Hera, wife of Zeus, was jealous of her husband’s illicit affair and craftily persuaded Semele to ask Zeus to reveal himself to her in all his godly splendour. This was too much for the mortal and she immediately expired; however, Zeus took the unborn child and reared him in his thigh. Dionysus travelled widely, even as far as India, and spread his cult throughout Greece, indeed he was known as being of an eastern origin himself. Orgiastic rituals were held in his honor, where the participants were taken over by a Dionysian frenzy of dancing and merriment to such a degree that they transcended themselves. It is believed that theatre sprang from this activity as, like Dionysus’ worshippers, actors strive to leave behind their own persona and become one with the character they are playing. Indeed, priests of Dionysus were given seats of honor in Greek theatres. (79) As the Romans incorporated Greek culture into itself, so also came the worship of Dionysus. The appearance of Greek culture had been, for the most part, positive. Under this Greek influence, the Roman gods became more human, exhibiting such diverse characteristics as jealousy, love, and hate. However, unlike in Greece, in Rome an individual’s self-expression of belief was not considered as important as adherence to ritual. In an effort to avoid religious zeal, the state demanded a strict adherence to a rigid set of rituals. While this integration of the Greeks gods was never seen as a viable threat — they easily fit into the existing array of gods — some cults proved to be something completely different: a genuine danger to the prevailing state religion. In 186 BCE the Roman Senate, recognizing a potential menace, suppressed the worship of the Greek god of wine, Dionysus, known to the Romans as Bacchus. His worship is best remembered for its intoxicating festival held on March 17, a day when a Roman male youth would supposedly become a man. The cult was viewed as being excessively brutal, supposedly involving ritual murder and sexual excess. As a result, many of its adherents were either imprisoned or executed. It should be noted, however, that the authority’s fear of this cult was largely generated, not from first-hand experience (the cult’s rituals were always conducted in secret) but from the writings of the historian Livy (c. 64 BCEâ€“17 CE) who consistently portrayed the cult as a dangerous menace to social stability and characterized adherents as little more than drunken beasts. (80) Cybele Cult Originally, the Cybelean cult was brought to Rome during the time of the Second Punic War (218â€“201 BCE). At that time the Carthaginian general Hannibal was wreaking havoc in Italy, posing a serious threat to the city of Rome. The Sibylline Books, books of prophecy consulted by the Roman Senate in times of emergencies, predicted that Italy would be freed by an Idaean mother of Pessinus; to many, this meant Cybele. A black meteorite, representing the goddess, was brought to Rome from Asia Minor in 204 BCE. Miraculously, Hannibal and his army left shortly afterwards to defend Carthage against the invading Romans; a temple honoring Cybele would be built on Palatine Hill in 191 BCE. The cult eventually achieved official recognition during the reign of Emperor Claudius (41â€“44 CE). Ultimately, her appeal as an agrarian goddess would enable her to find adherents in northern Africa as well as Transalpine Gaul. Due to its agricultural nature, her cult had tremendous appeal to the average Roman citizen, more so women than men. She was responsible for every aspect of an individual’s life. She was the mistress of wild nature, symbolized by her constant companion, the lion. Not only was she was a healer (she both cured and caused disease) but also the goddess of fertility and protectress in time of war (although, interestingly, not a favorite among soldiers), even offering immortality to her adherents. She is depicted in statues either on a chariot pulled by lions or enthroned carrying a bowl and drum, wearing a mural crown, flanked by lions. Followers of her cult would work themselves into an emotional frenzy and self-mutilate, symbolic of her lover’s self-castration. Important to the worship of Cybele was Attis, the Phrygian god of vegetation, also considered a resurrection god (similar to the Greek Adonis). Supposedly, Attis was Cybele’s lover, although some sources claim him to be her son. Unfortunately, he fell in love with a mortal and chose to marry. According to one story, on the day of their wedding banquet, the irate and jealous goddess apparently struck panic into those who attended the wedding. Afraid for his own safety (no mention is made of his bride), the frightened groom fled to the nearby mountains where he gradually became insane, eventually committing suicide but not before castrating himself. Regaining her own sanity, the remorseful Cybele appealed to Zeus to never allow Attis’s corpse to decay. Myth claims that he would return to life during the yearly rebirth of vegetation; thus identifying Attis as an early dying-and-reviving god figure. Cybele was one of many cults that appeared in Rome. Some were considered harmless, the Cult of Isis for example, and allowed to survive while others, like Bacchus, were seen as a serious threat to the Roman citizens and was persecuted. Of course, almost all of these cults disappeared with the arrival of Christianity when Rome became the center of this new religion. The Cult of Cybele lasted until the 4 th century CE, at which time Christianity dominated the religious landscape and pagan beliefs and rituals gradually became transformed or discarded to suit the new faith. 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nyCPLOiFIh5UEIKu	5.1: Managing Your Research Project	5.1: Managing Your Research Project - Identify reasons for outlining the scope and sequence of a research project. - Recognize the steps of the research writing process. - Develop a plan for managing time and resources to complete the research project on time. - Identify organizational tools and strategies to use in managing the project. The prewriting you have completed so far has helped you begin to plan the content of your research paper—your topic, research questions, and preliminary thesis. It is equally important to plan out the process of researching and writing the paper. Although some types of writing assignments can be completed relatively quickly, developing a good research paper is a complex process that takes time. Breaking it into manageable steps is crucial. Review the steps outlined at the beginning of this chapter. Steps to Writing a Research Paper - Choose a topic. - Schedule and plan time for research and writing. - Conduct research. - Organize research - Draft your paper. - Revise and edit your paper. You have already completed step 1. In this section, you will complete step 2. The remaining steps fall under two broad categories—the research phase of the project (steps 3 and 4) and the writing phase (steps 5 and 6). Both phases present challenges. Understanding the tasks involved and allowing enough time to complete each task will help you complete your research paper on time with a minimal amount of stress. Planning Your Project Each step of a research project requires time and attention. Careful planning helps ensure that you will keep your project running smoothly and produce your best work. Set up a project schedule that shows when you will complete each step. Think about how you will complete each step and what project resources you will use. Resources may include anything from library databases and word-processing software to interview subjects and writing tutors. To develop your schedule, use a calendar and work backward from the date your final draft is due. Generally, it is wise to divide half of the available time on the research phase of the project and half on the writing phase. For example, if you have a month to work, plan for two weeks for each phase. If you have a full semester, plan to begin research early and to start writing by the middle of the term. You might think that no one really works that far ahead, but try it. You will probably be pleased with the quality of your work and with the reduction in your stress level. As you plan, break down major steps into smaller tasks if necessary. For example, step 3, conducting research, involves locating potential sources, evaluating their usefulness and reliability, reading, and taking notes. Defining these smaller tasks makes the project more manageable by giving you concrete goals to achieve. Jorge had six weeks to complete his research project. Working backward from a due date of May 2, he mapped out a schedule for completing his research by early April so that he would have ample time to write. Jorge chose to write his schedule in his weekly planner to help keep himself on track. Review Jorge’s schedule. Key target dates are shaded. Note that Jorge planned times to use available resources by visiting the library and writing center and by meeting with his instructor. Figure $\PageIndex{1}$ - Working backward from the date your final draft is due, create a project schedule. You may choose to write a sequential list of tasks or record tasks on a calendar. - Check your schedule to be sure that you have broken each step into smaller tasks and assigned a target completion date to each key task. - Review your target dates to make sure they are realistic. Always allow a little more time than you think you will actually need. Plan your schedule realistically, and consider other commitments that may sometimes take precedence. A business trip or family visit may mean that you are unable to work on the research project for a few days. Make the most of the time you have available. Plan for unexpected interruptions, but keep in mind that a short time away from the project may help you come back to it with renewed enthusiasm. Another strategy many writers find helpful is to finish each day’s work at a point when the next task is an easy one. That makes it easier to start again. Writing at Work When you create a project schedule at work, you set target dates for completing certain tasks and identify the resources you plan to use on the project. It is important to build in some flexibility. Materials may not be received on time because of a shipping delay. An employee on your team may be called away to work on a higher-priority project. Essential equipment may malfunction. You should always plan for the unexpected. Staying Organized Although setting up a schedule is easy, sticking to one is challenging. Even if you are the rare person who never procrastinates, unforeseen events may interfere with your ability to complete tasks on time. A self-imposed deadline may slip your mind despite your best intentions. Organizational tools—calendars, checklists, note cards, software, and so forth—can help you stay on track. Throughout your project, organize both your time and your resources systematically. Review your schedule frequently and check your progress. It helps to post your schedule in a place where you will see it every day. Both personal and workplace e-mail systems usually include a calendar feature where you can record tasks, arrange to receive daily reminders, and check off completed tasks. Electronic devices such as smartphones have similar features. Organize project documents in a binder or electronic folder, and label project documents and folders clearly. Use note cards or an electronic document to record bibliographical information for each source you plan to use in your paper. Tracking this information throughout the research process can save you hours of time when you create your references page. Revisit the schedule you created in Exercise 1. Transfer it into a format that will help you stay on track from day to day. You may wish to input it into your smartphone, write it in a weekly planner, post it by your desk, or have your e-mail account send you daily reminders. Consider setting up a buddy system with a classmate that will help you both stay on track. Some people enjoy using the most up-to-date technology to help them stay organized. Other people prefer simple methods, such as crossing off items on a checklist. The key to staying organized is finding a system you like enough to use daily. The particulars of the method are not important as long as you are consistent. Anticipating Challenges Do any of these scenarios sound familiar? You have identified a book that would be a great resource for your project, but it is currently checked out of the library. You planned to interview a subject matter expert on your topic, but she calls to reschedule your meeting. You have begun writing your draft, but now you realize that you will need to modify your thesis and conduct additional research. Or you have finally completed your draft when your computer crashes, and days of hard work disappear in an instant. These troubling situations are all too common. No matter how carefully you plan your schedule, you may encounter a glitch or setback. Managing your project effectively means anticipating potential problems, taking steps to minimize them where possible, and allowing time in your schedule to handle any setbacks. Many times a situation becomes a problem due only to lack of planning. For example, if a book is checked out of your local library, it might be available through interlibrary loan, which usually takes a few days for the library staff to process. Alternatively, you might locate another, equally useful source. If you have allowed enough time for research, a brief delay will not become a major setback. You can manage other potential problems by staying organized and maintaining a take-charge attitude. Take a minute each day to save a backup copy of your work on a portable hard drive. Maintain detailed note cards and source cards as you conduct research—doing so will make citing sources in your draft infinitely easier. If you run into difficulties with your research or your writing, ask your instructor for help, or make an appointment with a writing tutor. Identify five potential problems you might encounter in the process of researching and writing your paper. Write them on a separate sheet of paper. For each problem, write at least one strategy for solving the problem or minimizing its effect on your project. Writing at Work In the workplace, documents prepared at the beginning of a project often include a detailed plan for risk management. When you manage a project, it makes sense to anticipate and prepare for potential setbacks. For example, to roll out a new product line, a software development company must strive to complete tasks on a schedule in order to meet the new product release date. The project manager may need to adjust the project plan if one or more tasks fall behind schedule. - To complete a research project successfully, a writer must carefully manage each phase of the process and break major steps into smaller tasks. - Writers can plan a research project by setting up a schedule based on the deadline and by identifying useful project resources. - Writers stay focused by using organizational tools that suit their needs. - Anticipating and planning for potential setbacks can help writers avoid those setbacks or minimize their effect on the project schedule.	2,106	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Composition/Advanced_Composition/Book%3A_English_Composition_II_-_Rhetorical_MethodsBased_(Lumen)/05%3A_Research_Proposal/5.01%3A_Managing_Your_Research_Project	libretexts	libretexts-0000.json.gz:5524	https://human.libretexts.org/Bookshelves/Composition/Advanced_Composition/Book%3A_English_Composition_II_-_Rhetorical_MethodsBased_(Lumen)/05%3A_Research_Proposal/5.01%3A_Managing_Your_Research_Project
wDmHgI9FMlQW6Hxc	2: A Brief Introduction to Research Design	2: A Brief Introduction to Research Design To consult the statistician after an experiment is finished is often merely to ask him to conduct a post mortem examination. He can perhaps say what the experiment died of. – Sir Ronald Fisher 6 In this chapter, we’re going to start thinking about the basic ideas that go into designing a study, collecting data, checking whether your data collection works, and so on. It won’t give you enough information to allow you to design studies of your own, but it will give you a lot of the basic tools that you need to assess the studies done by other people. However, since the focus of this book is much more on data analysis than on data collection, I’m only giving a very brief overview. Note that this chapter is “special” in two ways. Firstly, it’s much more psychology-specific than the later chapters. Secondly, it focuses much more heavily on the scientific problem of research methodology, and much less on the statistical problem of data analysis. Nevertheless, the two problems are related to one another, so it’s traditional for stats textbooks to discuss the problem in a little detail. This chapter relies heavily on Campbell and Stanley (1963) for the discussion of study design, and Stevens (1946) for the discussion of scales of measurement. Later versions will attempt to be more precise in the citations.	301	common-pile/libretexts_filtered	https://stats.libretexts.org/Bookshelves/Applied_Statistics/Learning_Statistics_with_R_-_A_tutorial_for_Psychology_Students_and_other_Beginners_(Navarro)/02%3A_A_Brief_Introduction_to_Research_Design	libretexts	libretexts-0000.json.gz:49553	https://stats.libretexts.org/Bookshelves/Applied_Statistics/Learning_Statistics_with_R_-_A_tutorial_for_Psychology_Students_and_other_Beginners_(Navarro)/02%3A_A_Brief_Introduction_to_Research_Design
ev1Ig5AaeqiNImjl	My Franconia, Bavaria Relatives	Hutschdorf Church Records 27 Norma (Kirmse) Rauh also had in her files copies of research correspondence on the Bär(Baer) and Rauh families. . Letter Betty Rauh Hosea received the following letter from the Evan.-Luth. Pfarramf Hutschdorf dated September 21, 1990. Attachments: Translation The following translation was included in the file: We received your inquiry about genealogical research and understood all that you are seeking. But unfortunately we cannot reply in English. We hope that you can have it translated. We inform you of the following: 1. Elisabetha Bär was born Wednesday, 1 September, at 4 o’clock in the afternoon in Hutschdorf. Her parents are Johann Bär, day laborer in Hutschdorf, her mother is Margaretha nee Bär of Lanzenreuth, godmother was Elisabetha, wife of Wolfgang Eschenbacher of Katzenlohe (also in the Hutschdorf Parish). Please see copy no. 1. Incidentally, all copies are from the volume “Baptisms, Marriages, Deaths 1782-1851,” in this case “Births and Baptisms,” year 1819, p. 284. .2. The marriage of the parents of Elisabetha Bär was on 25 May 1811. Please see copy no. 2 (year 1811, p. 74) 3. Johann Bär was born on 28 June 1784 in Hutschdorf. His father is Master Martin Bär, tailor and day laborer in Hutschdorf; his mother Barbara nee Listin of Kemeritz (also in Hutschd. Parish). (copy no. 3) (year 1784, p. 18) 4. Margaretha Bär was born on 30 April 1791 in Lanzenreuth. Her father is Johann Michael Bär, farmer in Lazenreuth; her mother Kordula nee Mullerin of Lingenstadt. Please see no. 4, year 1791, p. 66. 5. We regret that we could not find the marriage of Elisabetha Bär and Johann Rauh. Discussion This letter is interesting as it shows that early immigrants from Bavaria to Perry County and who became members of the Friedenberg Church were from Hutschdorf, Bavaria, the ancestral home of Barbara Kraus and her sisters. This letter is discussed in two books about the Bavarian immigrants to Perry County, Missouri: - Friedenberg Lutheran Historical Society Book Committee. Friedenberg Remembrances: A Story of Peace, Faith and Life. Printed by Lineage, USA. 1998. - Charles Rauh. Rauh: Our Great Heritage, 2007. Produced by Susan Swartwout and Mandy Henley. As is noted in these books, Elizabeth Bär(Baer) immigrated to Perry County, Missouri in 1840 with her family aboard the Brig Neptune along with her future husband John Rauh. See Chapter Rauh Family for a discussion of the relationship of the Rauh family to the Kirmse family.	530	common-pile/pressbooks_filtered	https://pressbooks.pub/mybavarianrelatives/chapter/baer-rauh-hutschdorf-letter/	pressbooks	pressbooks-0000.json.gz:24677	https://pressbooks.pub/mybavarianrelatives/chapter/baer-rauh-hutschdorf-letter/
bV9iuooSDIjvpYnJ	Basics of American Politics	1 Request Access This text is openly licensed and is accessible to all by navigating using the “Contents” menu in the upper left hand corner. To preserve academic integrity and prevent students from gaining unauthorized access, we have hidden faculty resources and assessments. Please contact<EMAIL_ADDRESS>to request access to the faculty resources for this course. Once you have been given access, you’ll be able to use the resources provided through the drop down in the upper left hand corner. Overview of Faculty Resources This is a community course developed by an Achieving the Dream grantee. They have either curated or created a collection of faculty resources for this course. Since the resources are openly licensed, you may use them as is or adapt them to your needs. Now Available - Reflection Posts - Paper Topics - Question Banks - Additional Resources Share Your Favorite Resources If you have sample resources you would like to share with other faculty teaching this course, please send them with an explanatory message and learning outcome alignment to oer@achievingthedream.org.	224	common-pile/pressbooks_filtered	https://library.achievingthedream.org/tccampolitics/chapter/request-access/	pressbooks	pressbooks-0000.json.gz:74847	https://library.achievingthedream.org/tccampolitics/chapter/request-access/
S2JoK2PDITJlf978	7.3: Additional Resources	7.3: Additional Resources This section moves us from the Medieval period of literature to the Renaissance. The Renaissance in England started later than the Renaissance in Italy (which is the place most people think about when they hear the term “Renaissance”). The resource reading from the Encylopedia Brittanica provides a good overview of the European Renaissance. This module’s play, The Tragical History of Dr. Faustus, shares some roots with morality plays (such as Everyman , which we read a few weeks ago), but as you’ll see from the from the resource readings, the view of religion and its central role in society has changed. The resource reading from Dartmouth addresses this. In terms of literary style, the play is written in blank verse, a verse style also used by Shakespeare. For many, Shakespeare is assumed to be the only English Renaissance playwright, but as you can see, others also existed. According to one definition: “Blank verse is a literary device defined as un-rhyming verse written in iambic pentameter . In poetry and prose , it has a consistent meter with 10 syllables in each line ( pentameter ); where, unstressed syllables are followed by stressed ones and five of which are stressed but do not rhyme . It is also known as un-rhymed iambic pentameter.” (See http://literarydevices.net/blank-verse/ for further elaboration of the definition and to access the hyperlinks in the definition.) You can test the meter by counting the syllables in a line. Normally there will be 10 in each line with every other syllable stressed (meaning accented, or pronounced with more emphasis). Occasional exceptions can happen in the line length and stress patterns, but if it varies significantly or makes a new pattern (such as suddenly using much shorter lines or switching to rhymed lines), you can assume this is done for some literary reason, such as highlighting something about a character or the plot. Background and Interpretation Encyclopedia Brittanica’s article on the “Renaissance: European History” Read this overview of the Renaissance from the Encyclopedia Brittanica, keeping in mind that our class’s focus is on the Renaissance in Britain. It did not happen in a vacuum, however, so knowing more about the overall Renaissance in Europe puts the English Renaissance into perspective. Dartmouth College’s article on “Christopher Marlowe’s Doctor Faustus” This is a good introductory note from Dartmouth about Marlowe’s The Tragical History of Dr. Faustus (which sometimes may be referred to by the shortened title of Dr. Faustus ). Luminarium’s article on “Christopher Marlowe (1564-1593)” This is a detailed and useful biography of Marlowe and an overview of his works from Luminarium.org. Marlowe had a colorful life, as you will see, and some of the information in the biography may shed some light on some of the ideas in the play. Audio/Video Files Full length video of a stage production of Dr. Faustus from the Oxford Theatre Guild. Just as with movies, stage productions represent the director’s and other artists’ interpretation of the written play. Keep this in mind as you watch any stage production of any play. Our focus is on the content of the text; the staging, sets, casting, music, or other aspects of the performance in a production are not intrinsic to the text we are studying. Suggestion: In order to better follow along, have a copy of the play with you while you watch the video. https://youtu.be/ILwZmZdk28Y?list=PL...O2r-QIL6pFxROi Clip of a stage production from Shakespeare’s Globe Theater (you’ll notice the difference in costumes, sets, casting, and staging compared with the Oxford video). Full length audio recording of the play by LibraVox/GreenAudioBooks (follow along with the print text). - Survey of English Literature I. Authored by : Wendy Howard Gray. Provided by : Reynolds Community College. Located at : http://www.reynolds.edu/ . License : CC BY: Attribution - Doctor Faustus - Marlowe - Shakespeare's Globe Theatre. Authored by : Kultur Films. Located at : https://youtu.be/ILwZmZdk28Y?list=PLfL2Ni1dDONNv_a_SvrO2r-QIL6pFxROi . License : All Rights Reserved . License Terms : Standard YouTube License - Christopher Marlowe's Doctor Faustus, performed by Oxford Theatre Guild, December 2013. Authored by : Mike Taylor. Located at : https://youtu.be/V97pMacSp-0 . License : All Rights Reserved . License Terms : Standard YouTube License - Doctor Faustus - FULL Audio Play - by Christopher Marlowe. Authored by : GreenAudioBooks. Located at : https://youtu.be/ZF3o-svLH5o . License : All Rights Reserved . License Terms : Standard YouTube License	945	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Literature_and_Literacy/British_and_Irish_Literature/English_Literature_I_(Lumen)/07%3A_Dr._Faustus/7.03%3A_Additional_Resources	libretexts	libretexts-0000.json.gz:49151	https://human.libretexts.org/Bookshelves/Literature_and_Literacy/British_and_Irish_Literature/English_Literature_I_(Lumen)/07%3A_Dr._Faustus/7.03%3A_Additional_Resources
-fY-lQd8ErGAe9_L	Page 7.2: Origin of Biodiversity	Page 7.2: Origin of Biodiversity What biological process is responsible for biodiversity? All species —from the bacteria on our skin to the birds outside—evolved at some point from a different species. Although it may seem that living things today stay much the same from generation to generation, that is not the case because evolution is ongoing. Evolution is the process through which the characteristics of a species change over time, which can ultimately cause new species to arise. Figure $\PageIndex{1}$. The diversity of life on Earth is the result of evolution, a continuous process that is still occurring. (credit “wolf”: modification of work by Gary Kramer, USFWS; credit “coral”: modification of work by William Harrigan, NOAA; credit “river”: modification of work by Vojtěch Dostál; credit “protozoa”: modification of work by Sharon Franklin, Stephen Ausmus, USDA ARS; credit “fish” modification of work by Christian Mehlführer; credit “mushroom”, “bee”: modification of work by Cory Zanker; credit “tree”: modification of work by Joseph Kranak)The theory of evolution is the unifying theory of biology, meaning it is the framework within which biologists ask questions about the living world. Its power is that it provides direction for predictions about living things that are borne out in experiment after experiment. The Ukrainian-born American geneticist Theodosius Dobzhansky famously wrote that “nothing makes sense in biology except in the light of evolution.” He meant that the principle that all life has evolved and diversified from a common ancestor is the foundation from which we understand all other questions in biology. Discovering How Populations Change The theory of evolution by natural selection describes a mechanism for how species can change over time. That species change was suggested and debated well before Darwin. The view that species were unchanging was grounded in the writings of Plato, yet there were also ancient Greeks that expressed evolutionary ideas. In the eighteenth century, ideas about the evolution of animals were reintroduced by the various naturalists. At the same time, James Hutton, the Scottish naturalist, proposed that geological change occurred gradually by the accumulation of small changes from processes (over long periods of time) just like those happening today. This contrasted with the predominant view that the geology of the planet was a consequence of catastrophic events occurring during a relatively brief past. Hutton’s view was later popularized by the geologist Charles Lyell in the nineteenth century. Lyell became a friend to Darwin and his ideas were very influential on Darwin’s thinking. Lyell argued that the greater age of Earth gave more time for gradual change in species, and the process provided an analogy for gradual change in species. Charles Darwin and Natural Selection Natural selection as a mechanism for evolution was independently conceived of and described by two naturalists, Charles Darwin and Alfred Russell Wallace, in the mid-nineteenth century. Importantly, each spent years exploring the natural world on expeditions to the tropics. From 1831 to 1836, Darwin traveled around the world on H.M.S. Beagle , visiting South America, Australia, and the southern tip of Africa. Wallace traveled to Brazil to collect insects in the Amazon rainforest from 1848 to 1852 and to the Malay Archipelago from 1854 to 1862. Darwin’s journey, like Wallace’s later journeys in the Malay Archipelago, included stops at several island chains, the last being the Galápagos Islands (west of Ecuador). On these islands, Darwin observed species of organisms on different islands that were clearly similar, yet had distinct differences. For example, the ground finches inhabiting the Galápagos Islands comprised several species that each had a unique beak shape (Figure $\PageIndex{2}$). He observed both that these finches closely resembled another finch species on the mainland of South America and that the group of species in the Galápagos formed a graded series of beak sizes and shapes, with very small differences between the most similar. Darwin imagined that the island species might be all species modified from one original mainland species. In 1860, he wrote, “Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends.” Figure $\PageIndex{2}$. Darwin observed that beak shape varies among finch species. He postulated that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources. This illustration shows the beak shapes for four species of ground finch: 1. Geospiza magnirostris (the large ground finch), 2. G. fortis (the medium ground finch), 3. G. parvula (the small tree finch), and 4. Certhidea olivacea (the green-warbler finch).Wallace and Darwin both observed similar patterns in other organisms and independently conceived a mechanism to explain how and why such changes could take place. Darwin called this mechanism natural selection. Natural selection, Darwin argued, was an inevitable outcome of three principles that operated in nature. First, there exists variation in traits among individuals within a population, and these traits are inherited, or passed from parent to offspring. Second, more offspring are produced than are able to survive; in other words, resources for survival and reproduction are limited. And lastly, there is a competition for those resources in each generation. Out of these three principles, Darwin and Wallace reasoned that offspring with inherited characteristics that allow them to best compete for limited resources will survive and have more offspring than those individuals with variations that are less able to compete. Because characteristics are inherited, these traits will be better represented in the next generation. This will lead to change in populations over generations in a process that Darwin called “ descent with modification .” In sum, we can define natural selection as a process the causes beneficial traits to become more common in a population over time, causing the population to evolve. Figure $\PageIndex{3}$. (a) Charles Darwin and (b) Alfred Wallace wrote scientific papers on natural selection that were presented together before the Linnean Society in 1858.Papers by Darwin and Wallace (Figure $\PageIndex{3}$) presenting the idea of natural selection were read together in 1858 before the Linnaean Society in London. The following year Darwin’s book, On the Origin of Species, was published, which outlined in considerable detail his arguments for evolution by natural selection. Natural selection can only take place if there is variation , or differences, among individuals in a population. Importantly, these differences must have some genetic basis, otherwise natural selection would not lead to change in the next generation because there would be no way to transmit those traits from one generation to the next. Genetic diversity in a population comes from two main sources: mutation and sexual reproduction. Mutation, a permanent change in DNA sequence is the ultimate source of new genetic variation in any population. An individual that has a mutated gene might have a different trait than other individuals in the population. Without variation in traits, nature would not be able to select the traits that are best adapted for the organisms’ environment at that particular time. Evolutionary change in action The development of antibiotic resistant bacteria is an example of evolution through natural selection and it has been directly observed by scientists. How does this happen? Imagine a person that has a bacterial infection: their body is being attacked by billions of bacteria. Because there is genetic variation in populations, some individual bacteria may already possess traits that allow them to tolerate antibiotic drugs. When the infected person is prescribed antibiotics, the drug attacks and kills the entire population, except for those bacteria that can resist the drug. These bacteria survive because they had a trait that was beneficial and thus nature selected for it. The surviving population will all be resistant to the drug and continue to reproduce, multiple, and pass down that beneficial trait to all offspring. The population has now evolved because all individuals have the antibiotic-resistant trait, whereas before it was rare. It is important to realize that evolution occurs at the population level and is reliant upon genetic variation that was already present. Without that variation, there is nothing for nature to select for. The rise and spread of antibiotic resistant bacteria is an emerging environmental issue and will be discussed in a later chapter. Attribution “Discovering How Populations Change” by Open Stax is licensed under CC BY 4.0 . Modified from the original by Matthew R Fisher.	1,813	common-pile/libretexts_filtered	https://eng.libretexts.org/Courses/Hawaii_Community_College/Ecology_and_Environment%3A_BIOL_124_at_Hawaii_Community_College/07%3A_Conservation_and_Biodiversity/7.02%3A_Origin_of_Biodiversity	libretexts	libretexts-0000.json.gz:16752	https://eng.libretexts.org/Courses/Hawaii_Community_College/Ecology_and_Environment%3A_BIOL_124_at_Hawaii_Community_College/07%3A_Conservation_and_Biodiversity/7.02%3A_Origin_of_Biodiversity
2tFrK1-3yvY1gknA	1.3: Technology in Education - Looking at Fiction to Find Real Possibilities	1.3: Technology in Education - Looking at Fiction to Find Real Possibilities - - Last updated - Save as PDF In his “lost novel,” Paris in the 20th Century, science fiction author Jules Verne predicted gasoline-powered automobiles, high-speed trains, calculators, the concept of the Internet, and several other technologies invented well after 1863. Verne believed strongly that humans could realize all such predictions: “Anything one man can imagine, other men can make real” (Verne, n.d., para. 1). As scientists in various fields may have taken their cues from Jules Verne, we too can get some ideas about the future of technology and education from science fiction. Looking at some science fiction within the past 15 years, we will start with predictions that are less farreaching than those contained within Jules Verne’s works. For example, in 1993 a low-grade action movie called Demolition Man depicted a teacher in the year 2023 talking to distance learners who attended class via individual video monitors placed around an empty table. The students’ heads, as shown on the monitors, followed the instructor’s movements as he paced around the room. Most or all aspects of this scenario are already possible with today’s videoconferencing solutions, high bandwidth connectivity, and cameras that use infrared beams to automatically follow a moving subject. Three years ago, Florence Olsen (2003) depicted immersive videoconferencing solutions with virtual students beamed into another classroom hundreds of miles away. In some cases, perhaps, Moore’s Law—computerprocessing power, measured by the number of transistors on integrated circuits, doubling every 18 months— makes it more difficult to look too far into the future because the future arrives so much more quickly. At the same time, when we read Neal Stephenson’s The Diamond Age, we can see the potential to realize some of his predictions in less dramatic fashion. For example, when people first study sign language, they may dream about signing in full sentences, even though they cannot yet sign in the waking world. In this scenario, the brain contains the previously learned phrases in a mental “database” and stitches them together in new ways during the dream. Soon some instructional designer will put a comprehensive set of sign language video clips into an online database that will allow anyone to learn full sentences quickly by typing text and watching the dynamically generated compilation of the sign language equivalent. Additionally, education and technology have been combined to create tutoring software that learns what you know and steers you to specific lesson components that will fill your learning gaps. These “intelligent tutors” exist for math, accounting, physics, computer science, and other disciplines. A final set of educational predictions in science fiction is too far out to tell if they are possible. In 1999, a film called The Matrix strongly contradicts William Butler Yeats, who said, “Education is not the filling of a pail, but the lighting of a fire” (Yeats, n.d., para. 1). In the film, the characters plug a cable into the back of their heads and go through “programs” that embed knowledge and skills directly into their brains. The lead character, Neo, becomes a martial arts expert in hours instead of years. Another character, Trinity, learns how to pilot a helicopter in seconds. In reality, humans have had little success linking computers to the brain. Recent developments, such as real-time brain control of a computer cursor (Hochber, Serruya, Friehs, Mukand, Saleh, Caplan, Branner, Chen, Penn & Donoghue, 2006), allow us to believe that some day Matrix-style education may be possible. By then, hopefully, we will have mastered how to teach higher level thinking skills, since this futuristic just-in-time learning presumably will let us skip over lower level skills.	794	common-pile/libretexts_filtered	https://socialsci.libretexts.org/Bookshelves/Education_and_Professional_Development/Book%3A_Education_for_a_Digital_World_-_Advice_Guidelines_and_Effective_Practice_from_Around_Globe_(Hirtz)/01%3A_Emerging_Technologies_in_E-learning/1.3%3A_Technology_in_Education_-_Looking_at_Fiction_to_Find_Real_Possibilities	libretexts	libretexts-0000.json.gz:22192	https://socialsci.libretexts.org/Bookshelves/Education_and_Professional_Development/Book%3A_Education_for_a_Digital_World_-_Advice_Guidelines_and_Effective_Practice_from_Around_Globe_(Hirtz)/01%3A_Emerging_Technologies_in_E-learning/1.3%3A_Technology_in_Education_-_Looking_at_Fiction_to_Find_Real_Possibilities
2p7JzEeTpAmZDk9-	English Composition	23 8. Instruction for Discussion You may want to print this document out. Your next task will be to participate in an online discussion. This document provides instructions on how to initiate and respond to discussions. You can also return to the Tutorial for a “refresher.” A “discussion thread” is started each time you submit a discussion item. Each response to the original question is indented once – a response to a response is indented a second time – etc. This system of indents helps us determine which responses go together. By using the “collapse” and “expand,” , and “next” or “previous” document menu options in the navigational bar of the course, or by using the “collapse” and “expand” “twisties,” you can follow the give and take of a threaded discussion – the web equivalent of a classroom discussion. Responding to the main item To compose your response to a main discussion item you are reading, click on the “Respond” link located at the bottom of that page. In the form, title your response in the Subject field and then respond in the boxed area. A good title tells something of the nature of your personal response. “Response to Discussion 1” is not a very useful title, particularly if everyone in your course uses the same one. Responding to someone else’s response If you are already reading someone else’s response document, click on the “Respond” link located at the bottom of that page to respond to that response. Make sure that you respond on the document intended so that your contribution will line up in the threaded discussion in the right place. Submitting your response When you have completed your response, click the “Submit” button at the bottom of the page. Correcting your response If you discover an error in your document after you submit it, a misspelled word or an incomplete thought, you can “Edit” your document. The Edit button appears at the top of your document after you submit it the first time. When you have finished your edits, click the submit button at the bottom of the page. Quality discussion responses Responses such as: “I agree.”, “Good question” or “Good answer” / Any response that is just an opinion, or is unsubstantiated / any response that is carelessly typed, poorly thought-out, grammatically incorrect or confusing / any response that is disrespectful of another student or any other person, etc., are not acceptable.A high quality response contains information from the textbook or other valid source, or applies a concept from the text or course in a meaningful way, or facilitates understanding of the course material or topic. Please review information in the Course Information area of the course for guidelines and specific information on how you will be evaluated on your participation in “Course Discussions.” Netiquette As discussion is of a public nature, please observe proper “netiquette” — courteous and appropriate forms of communication and interaction over the Internet (in online discussions). This means no personal attacks, obscene language, or intolerant expression. All viewpoints should be respected.	661	common-pile/pressbooks_filtered	https://library.achievingthedream.org/clintonenglishcomp/chapter/8-instruction-for-discussion/	pressbooks	pressbooks-0000.json.gz:20598	https://library.achievingthedream.org/clintonenglishcomp/chapter/8-instruction-for-discussion/
WKnzPrafdQ1YSy7w	BC Health Care Assistant Self-Evaluation Competency Profile	Primary Navigation Want to create or adapt books like this? Learn more about how Pressbooks supports open publishing practices. Book Contents Navigation Introduction Kathlyn Palafox 1. Competency:Health and Caring Provincial Health Care Assistant Core Competency Advisory 2. Competency: Plan of Care 3. Competency: Communication Skills 4. Competency: Interdisciplinary Team Care 5. Competency: Safety 6. Competency: Responsibility, Accountability and Ethical Behaviour 7. Self-Evaluation for Health and Caring Competencies 8. Self-Evaluation for the Plan of Care Competencies 9. Self-Evaluation for Communication Skills Competencies 10. Self-Evaluation for Interdisciplinary Care Team Competencies 11. Self-Evaluation for Safety Competencies 12. Self-Evaluation for Responsibility, Accountability and Ethical Behaviour Competencies Appendix 1 BC Health Care Assistants Core Competency Profile HCA Self-Evaluation of HCA Competencies This content is password protected. To view it please enter your password below: Password: Previous/next navigation Self-Evaluation for Health and Caring Competencies Copyright © by Kathlyn Palafox is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.	204	common-pile/pressbooks_filtered	https://pressbooks.bccampus.ca/bchcacompetency/chapter/self-evaluation-for-health-and-caring-competency/	pressbooks	pressbooks-0000.json.gz:5032	https://pressbooks.bccampus.ca/bchcacompetency/chapter/self-evaluation-for-health-and-caring-competency/
6I_6mz8VgrnUztFj	21.11: Checklist for Foley Catheter Insertion (Female)	21.11: Checklist for Foley Catheter Insertion (Female) Use the checklist below to review the steps for completion of “Foley Catheter Insertion (Female).” Steps Disclaimer: Always review and follow agency policy regarding this specific skill. - Gather supplies: peri-care supplies, clean gloves, Foley catheter kit, extra pair of sterile gloves, Velcro TM catheter securement device to secure Foley catheter to leg, linen bag, wastebasket, and light source (i.e., goose neck lamp or flashlight). - Perform safety steps: - Perform hand hygiene. - Check the room for transmission-based precautions. - Introduce yourself, your role, the purpose of your visit, and an estimate of the time it will take. - Confirm patient ID using two patient identifiers (e.g., name and date of birth). - Explain the process to the patient. - Be organized and systematic. - Use appropriate listening and questioning skills. - Listen and attend to patient cues. - Ensure the patient’s privacy and dignity. - Assess ABCs. - Assess for latex/iodine allergies, GYN surgeries, joint limitations for positioning, and any history of previous difficulties with catheterization. - Prepare the area for the procedure: - Place hand sanitizer for use during/after procedure on the table near the bed. - Place the catheter kit and peri-care supplies on the over-the-bed table. - Secure the wastebasket and linen cart/bag near the bed for disposal. - Ensure adequate lighting. Enlist assistance for positioning if needed. - Raise the opposite side rail. Set the bed to a comfortable height. - Position the patient supine and drape the patient with a bath blanket, exposing only the necessary area for patient privacy. - Apply nonsterile gloves and perform peri-care. - Remove gloves and perform hand hygiene. - Create a sterile field on the over-the-bed table. - Open the outer package wrapping. Remove the sterile wrapped box with the paper label facing upward to avoid spilling contents and place it on the bedside table or, if possible, between the patient’s legs. Place the plastic package wrapping at the end of the bed or on the side of the bed near you, with the opening facing you or facing upwards for waste. - Open the kit to create and position a sterile field: - Open the first flap away from you. - Open the second flap toward you. - Open side flaps. - Only touch within the outer 1” edge to position the sterile field on the table. - Carefully remove the sterile drape from the kit. Touching only the outermost edges of the drape, unfold and place the touched side of drape closest to linen, under the patient. Vertically position the drape between the patient’s legs to allow space for the sterile box and sterile tray. - Wash your hands and apply sterile gloves. - OPTIONAL: Place the fenestrated drape over the patient’s perineal area with gloves on inside of the drape, away from the patient’s gown, with peri-area visible through the opening. Maintain sterility. - Empty the lubricant syringe or package into the plastic tray. Place the empty syringe/package on the sterile outer package. - Simulate application of iodine/antimicrobial cleanser to cotton balls. - Remove the sterile urine specimen container and cap and set them aside. - Remove the tray from the top of the box and place it on the sterile drape. - Carefully remove the plastic catheter covering, while keeping the catheter in the sterile box. Attach the syringe filled with sterile water to the balloon port of the catheter; keep the catheter sterile. - Lubricate the tip of the catheter by dipping it in lubricant and place it in the box while maintaining sterility. - If preparing the kit on the bedside table, prepare to move the items to the patient. Place the plastic tray on top of the sterile box and carry as one unit to the sterile drape between the patient’s legs, taking care not to touch your gloves to the patient’s legs or bed linens. - Place the plastic top tray on the sterile drape nearest to the patient. An alternate option is to leave the plastic tray on top of the box until after cleaning is complete. - Tell the patient that you are going to clean the catheterization area and they will feel a cold sensation. - With your nondominant hand, gently spread the labia minora and visualize the urinary meatus. Your nondominant hand will now be nonsterile. This hand must remain in place throughout the procedure. - With your sterile dominant hand, use the forceps to pick up a cotton ball. Cleanse the periurethral mucosa with the saturated cotton ball. Discard the cotton ball after use into the plastic bag, not crossing the sterile field. Repeat for a total of three times using a new cotton ball each time. Discard the forceps in the plastic bag without touching the sterile gloved hand to the bag. - Pick up the catheter with your sterile dominant hand. Instruct the patient to take a deep breath and exhale or “bear down” as if to void, as you steadily insert the catheter maintaining sterility of the catheter until urine is noted. - Once urine is noted, continue inserting the catheter 1”-2”. Do not force the catheter. - With your dominant hand, inflate the retention balloon with the water-filled syringe to the level indicated on the balloon port of the catheter. With the plunger still pressed, remove the syringe and set it aside. Pull back on the catheter until resistance is met, confirming the balloon is in place. If the patient experiences pain during balloon inflation, deflate the balloon and insert the catheter farther into the bladder. If pain continues with the balloon inflation, remove the catheter and notify the patient’s provider. - Remove the sterile draping and supplies from the bed area and place them on the bedside table. Remove the bath blanket and reposition the patient. - Remove your gloves and perform hand hygiene. - Apply new gloves. Secure the catheter with securement device, allowing room as to not pull on the catheter. - Place the drainage bag below the level of the bladder, attaching it to the bed frame. - Perform peri-care as needed; assist the patient to a comfortable position. - Dispose of waste and used supplies. - Remove gloves and perform hand hygiene. - Assist the patient to a comfortable position, ask if they have any questions, and thank them for their time. - Ensure safety measures when leaving the room: - CALL LIGHT: Within reach - BED: Low and locked (in lowest position and brakes on) - SIDE RAILS: Secured - TABLE: Within reach - ROOM: Risk-free for falls (scan room and clear any obstacles) - Perform hand hygiene. - Document the procedure and related assessment findings. Report any concerns according to agency policy.	1,463	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/21%3A_Facilitation_of_Elimination/21.11%3A_Checklist_for_Foley_Catheter_Insertion_(Female)	libretexts	libretexts-0000.json.gz:8266	https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/21%3A_Facilitation_of_Elimination/21.11%3A_Checklist_for_Foley_Catheter_Insertion_(Female)
71pbt15KjXGjh9TA	11.4: Commonly Confused Words	11.4: Commonly Confused Words Just as a mason uses bricks to build sturdy homes, writers use words to build successful documents. Consider the construction of a building. Builders need to use tough, reliable materials to build a solid and structurally sound skyscraper. From the foundation to the roof and every floor in between, every part is necessary. And builders must use the right part for the job. If they try to use nuts and bolts where nails or screws are needed to hold together a building, the building may fall apart during the first earthquake. Just as builders need to use the right hardware, writers need to use strong, meaningful words from the first sentence to the last and in every sentence in between. You already know many words that you use everyday as part of your writing and speaking vocabulary. You probably also know that certain words fit better in certain situations. Letters, e-mails, and even quickly jotted grocery lists require the proper selection of vocabulary. Imagine you are writing a grocery list to purchase the ingredients for a recipe but accidentally write down cilantro when the recipe calls for parsley. Even though cilantro and parsley look remarkably alike, each produces a very different effect in food. This seemingly small error could radically alter the flavor of your dish! Having a solid everyday vocabulary will help you while writing, but learning new words and avoiding common word errors will make a real impression on your readers. Experienced writers know that deliberate, careful word selection and usage can lead to more polished, more meaningful work. This chapter covers word choice that will improve your writing. Vocabulary and the Reading-Writing Connection Adults gain most of their vocabulary simply by reading. The best way to improve your vocabulary is to read a wide variety of texts at the reading level you are at or slightly above. This will expose you to a wider range of words than you might be exposed to if you read the same sort of texts all the time. And such reading needn't just be academic in nature. Reading magazines about various hobbies, and with a variety of focuses (business, economics, fashion) will expose you to a wider vocabulary. Some people complain that while they read a variety of different kinds of texts, they just can't retain the new words they meet. XXXXX Commonly Confused Words Some words in English cause trouble for speakers and writers because these words share a similar pronunciation, meaning, or spelling with another word. These words are called commonly confused words. For example, read aloud the following sentences containing the commonly confused words new and knew. I liked her new sweater. I knew she would wear that sweater today. These words may sound alike when spoken, but they carry entirely different usages and meanings. New is an adjective that describes the sweater, and knew is the past tense of the verb to know . To read more about adjectives, verbs, and other parts of speech see Chapter 12 . Commonly Misused & Confused Words -- Part 1. Authored by: Vocabulary TV. License: All Rights Reserved. License Terms: Standard YouTube License. Recognizing Commonly Confused Words New and knew are just two of the words that can be confusing because of their similarities. Familiarize yourself with the following list of commonly confused words. Recognizing these words in your own writing and in other pieces of writing can help you choose the correct word. Commonly Confused Words A, An, And - A (article). Used before a word that begins with a consonant a key, a mouse, a screen - An (article). Used before a word that begins with a vowel sound an airplane, an ocean, an igloo - And (conjunction). Connects two or more words, phrases, or clauses together. peanut butter and jelly, pen and pencil, jump and shout Accept, Except - Accept (verb). Means to take or agree to something offered. They accepted our proposal for the conference. - Except (conjunction). Means only or but. We could fly there except the tickets cost too much. Affect, Effect - Affect (verb). Means to create a change Hurricane winds affect the amount of rainfall. - Effect (noun). Means an outcome or result The heavy rains will have an effect on the crop growth. Are, Our - My cousins are all tall and blonde. - Are (linking verb). Use to create the right verb tense We are thinking about going to the movies tonight. - We will bring our cameras to take pictures. By, Buy - By (preposition). Means next to My glasses are by the bed. - Buy (verb). Means to purchase I will buy new glasses after the doctor’s appointment. Capital, Capitol - Capital (adjective). Means upper case or excellent That is a capital idea! Proper nouns begin with capital letters. - Capitol (noun). The place where government is headquartered. Sacramento is the capitol of California. Its, It’s - Its (pronoun). A form of it that shows possession The butterfly flapped its wings. - It’s the most beautiful butterfly I have ever seen. Know, No - Know (verb). Means to understand or possess knowledge I know the male peacock sports the brilliant feathers. - No . Used to make a negative I have no time to visit the zoo this weekend. Lessen, Lesson - Lessen (verb). Means to reduce I will lessen the amount I spend on entertainment this month. - Lesson (noun). Something that one is taught The teacher taught the lesson about phonics to the kindergarteners. Loose, Lose - Loose (adjective). - Lose (verb). Means to forget, to give up, or to fail to earn something She will lose even more weight after finishing the marathon training. Of, Have - I studied maps of the city to know where to rent a new apartment. - Have (verb). Means to possess something I have many friends to help me move. - Have (linking verb). Used to connect verbs I should have helped her with that heavy box. Patience, Patients - Patience (noun). To wait without complaining The driver showed patience while following the slow truck in front of him. - Patients (plural noun). More than one person at the doctor's office or in the hospital. The patients did not have to wait to see the doctor. Principal, Principle - Principal (noun or adjective). The highest level position or the most important something. The principal component of a cup of tea is water. The principal of the high school hired a new vice principal. - Principle (noun). A philosophical point or fundamental truth She argued about the ethical principle. Quite, Quiet, Quit - My work will require quite a lot of concentration. - Quiet (adjective). Means not loud I need a quiet room to complete the assignments. - Quit (verb). Means to stop or to end I will quit when I am hungry for dinner. Right, Write - Right (adjective). Means proper or correct When bowling, she practices the right form. - Right (adjective). Also means the opposite of left The ball curved to the right and hit the last pin. - Write (verb). Means to communicate on paper After the team members bowl, I will write down their scores. Sea, See - Sea (noun). A body of water slightly smaller than an ocean; a portion of an ocean that is partly surrounded by land They set sail from the Adriatic Sea. - See (verb). To use the sense of the eyes I see all the flowers in the garden! Set, Sit - Set (verb). Means to put an item down She set the mug on the saucer. - Set (noun). Means a group of similar objects All the mugs and saucers belonged in a set . - Sit (verb). Means to lower oneself down on a chair or another place I’ll sit on the sofa while he brews the tea. Suppose, Supposed - Suppose (verb). Means to think or to consider I suppose I will bake the bread, because no one else has the recipe. - Suppose (verb). Means to suggest Suppose we all split the cost of the dinner. - Supposed (verb). The past tense form of the verb suppose, meaning required or allowed She was supposed to create the menu. Than, Then - Than (conjunction). Used to connect two or more items when comparing Registered nurses require less schooling than doctors. - Then (adverb). Means next or at a specific time Doctors first complete medical school and then obtain a residency. Their, They’re, There - Their (pronoun). A form of they that shows possession The dog walker feeds their dogs everyday at two o’clock. - They’re the sweetest dogs in the neighborhood. - There (adverb). Indicates a particular place The dogs’ bowls are over there , next to the pantry. - There (pronoun). Indicates the presence of something There are more treats if the dogs behave. Though, Tho - Tho (not a word). This is shorthand but is not really a word. - Though (subordinating conjuntion). Joins a less important idea to a more important idea Though many people may disagree, I get excited before finals week. Threw, Through Till, Until - Till (verb). Means to prepare soil for planting The farmer tilled the soil before planting lettuce seed. - Until (subordinating conjunction). Joins a clause that talks about something that happens before a certain time. We can't go on vacation until we have turned in our work. To, Two, Too - To (preposition). Indicates movement Let’s go to the circus. - To A word that completes an infinitive verb to play, to ride, to watch. - Two is the number after one. It describes how many. Two clowns squirted the elephants with water. - The tents were too loud, and we left. Use, Used - Use (verb). Means to apply for some purpose We use a weed whacker to trim the hedges. - He used the lawnmower last night before it rained. - Used to . Indicates something done in the past but not in the present He used to hire a team to landscape, but now he landscapes alone. Vain, Vein - Vain (adjective, noun compliment). Conceited, stuck on one's self. The vain people couldn't stop admiring themselves in the mirror. - Vein (noun). A cavity in the body through which blood flows that is smaller than an artery by larger than a capillary. The nurse had to find a vein in my arm in order to draw some blood. - Vein (noun). A metaphoric usage meaning "along those lines." I will continue in that vein when I take over the acting role. Who’s, Whose - Who’s the new student? Who’s met him? - Whose (pronoun). A form of who that shows possession Whose schedule allows them to take the new student on a campus tour? Your, You’re - Your (pronoun). A form of you that shows possession Your book bag is unzipped. - You’re the girl with the unzipped book bag. Tip: If you know you tend to confuse certain words, search for those words (the way you normally spell them) using the "find" feature in your word processing program. Then check to see if you have used and spelled that word correctly in the context you have written. The English language contains so many words; no one can say for certain how many words exist. In fact, many words in English are borrowed from other languages. Many words have multiple meanings and forms, further expanding the immeasurable number of English words. Although the list of commonly confused words serves as a helpful guide, even these words may have more meanings than shown here. When in doubt, consult an expert: the dictionary! Exercise 1 Complete the following sentences by selecting the correct word. - My little cousin turns ________(to, too, two) years old tomorrow. - The next-door neighbor’s dog is ________(quite, quiet, quit) loud. He barks constantly throughout the night. - ________(Your, You’re) mother called this morning to talk about the party. - I would rather eat a slice of chocolate cake ________(than, then) eat a chocolate muffin. - Before the meeting, he drank a cup of coffee and ________(than, then) brushed his teeth. - Do you have any ________(loose, lose) change to pay the parking meter? - Father must ________(have, of) left his briefcase at the office. - Before playing ice hockey, I was ________(suppose, supposed) to read the contract, but I only skimmed it and signed my name quickly, which may ________(affect, effect) my understanding of the rules. - Tonight she will ________(set, sit) down and ________(right, write) a cover letter to accompany her résumé and job application. - It must be fall, because the leaves ________(are, our) changing, and ________(it’s, its) getting darker earlier. Exercise 2 Complete the following sentences by filling in the blank line with the correct homynym or frequently misspelled words. 1. Kevin asked me a serious question and ____________ (than/then) interrupted me when I attempted to answer. 2. A hot compress will _________________ (lessen, lesson) the pain of muscle cramps. 3. Ashley was not a graceful _________________ (looser, loser) because she knocked her chair over and stormed off the basketball court. 4. (Accept, Except) _____________ for A. J., we all had our tickets to the play. 5. I am ______________ (threw, through) with this magazine, so you can read it if you like. 6. I don't care ____________ (who's, whose) coming to the party and _________________ (who's, whose) not. 7. Crystal could ___________ (sea, see) the soaring hawk through her binoculars. 8. The ____________________ (principal, principle) gave a long-winded speech about peer pressure. 9. Dr. Fox nearly lost her ________________________(patience, patients) with one of her __________________ (patience, patients). When writing, you need to choose the correct word according to its spelling and meaning in the context. Not only does selecting the correct word improve your vocabulary and your writing, but it also makes a good impression on your readers. It also helps reduce confusion and improve clarity. The following strategies can help you avoid misusing confusing words. - Use a dictionary. Look up words when you are uncertain of their meanings or spellings. Do not rely on spell check for commonly confused words. These are all words, and because word processing programs don't really understand meaning, they won't catch words that are correctly spelled but are used incorrectly. - Keep a list of words you commonly confuse. Be aware of the words that often confuse you. When you notice a pattern of confusing words, keep a list nearby, and consult the list as you write. Check the list again before you submit an assignment to your instructor. - Study the list of commonly confused words. You may not yet know which words confuse you, but before you sit down to write, study the words on the list. Prepare your mind for working with words by reviewing the commonly confused words identified in this chapter. Writing at Work $\PageIndex{1}$ All employers value effective communication. From an application to an interview to the first month on the job, employers pay attention to your vocabulary. You do not need a large vocabulary to succeed, but you do need to be able to express yourself clearly and avoid commonly misused words. When giving an important presentation on the effect of inflation on profit margins, you must know the difference between effect and affect and choose the correct word. When writing an e-mail to confirm deliveries, you must know if the shipment will arrive in to days, too days, or two days. Confusion may arise if you choose the wrong word. Consistently using the proper words will improve your communication and make a positive impression on your manager and colleagues. Exercise 3 The following paragraph contains eleven errors. Find each misused word and correct it by adding or changing a word to the proper word. The original United States Declaration of Independence sets in a case at the Rotunda for the Charters of Freedom as part of the National Archives in Washington, DC. Since 1952, over one million visitors each year of passed through the Rotunda too snap a photograph to capture they’re experience. This millisecond of light may not seem like enough to effect the precious document, but supposed how much light could be generated when all those milliseconds are added up. According to the National Archives administrators, its enough to significantly damage the historic document. So, now, the signs display quit a different message: “No Photography.” Visitors continue to travel to see the Declaration that began are country, but know longer can personal pictures serve as mementos. The administrators’ compromise, they say, is a visit to the gift shop for a preprinted photograph. Once you have found the errors, compare what you found with a classmate. If you disagree about any changes, bring up the question in class. Exercise 4 Proofread the following paragraph and correct any commonly confused or misspelled words. Grunge, or the Seattle sound, is a type of rock music that became quiet popular in the late 1980s and early 1990s. It began in Seattle, Washington. Grunge musicians rejected the dramatic an expensive stage productions that were trendy at the time. There music was striped down with an emphasis on distorted electric guitars. Grunge musicians did not ware makeup or sport extravagent hairstyles like many of the day’s rock musicians and bands. Many grunge musicians would by they’re clothes from secondhand stores. The lyrics too grunge songs were also quit different compared two what was populer at the time. Grunge lyrics are charecterized by dark or socially conscience themes. Grunge music is still admired today buy music lovers of all ages. Writing Application Review the latest assignment you completed for school or for work. Does it contain any commonly confused words? Circle each example and use the circled words to begin your own checklist of commonly confused words. Continue to add to your checklist each time you complete an assignment and find a misused word. Contributors and Attributions - Adapted from Writing for Success . Provided by: The Saylor Foundation. License: CC-NC-SA 3.0 .	3,927	common-pile/libretexts_filtered	https://human.libretexts.org/Courses/City_College_of_San_Francisco/Writing_Reading_and_College_Success%3A_A_First-Year_Composition_Course_for_All_Learners_(Kashyap_and_Dyquisto)/11%3A_Clarity_Conciseness_and_Style/11.04%3A_Commonly_Confused_Words	libretexts	libretexts-0000.json.gz:12424	https://human.libretexts.org/Courses/City_College_of_San_Francisco/Writing_Reading_and_College_Success%3A_A_First-Year_Composition_Course_for_All_Learners_(Kashyap_and_Dyquisto)/11%3A_Clarity_Conciseness_and_Style/11.04%3A_Commonly_Confused_Words
8c_-TOENuwgimpLX	6.1: Introduction	6.1: Introduction Often when teaching Fingerspelling, I repeatedly remind students, “Fingerspelling is a very active process, having very little to do with the actual letters!” The active process I’m referring to involves being 100% mindful of the topic of conversation, i.e. what are we talking about? When we know the context, then we know what to expect when the fingerspelling pops up. For example, if I’m signing about being outside in my garden and planting seeds, then suddenly fingerspell a word, you should be expecting a vegetable loan signs (from RS 4). If you aren’t paying attention to what we’re conversing about and fingerspelling pops up, you may very well freeze, clutch, ask for repetition and still not catch what’s being communicated. Meanwhile, I leave you to go tend my garden! Spending much time in the field of communication, where my sole job is listening to everything said and then interpreting the meaning into ASL, I see many obstacles to communicating that often don’t involve language errors but rather the inability to be fully present. In ASL communication there is one behavior that shows our partners are paying attention: - Eye contact – we spoke of eye contact in Lesson 3, and this new communication habit takes practice. When one is around Deaf communicators for any length of time, it’s noticed the difference between hearing and Deaf culture. Hearing culture tends towards multi-tasking while Deaf culture necessitates eye contact for communication and visual attunement. Multi-tasking is tough to do if we use our eyes for only one thing—the person in front of us. As an aside, many Deaf friends over the years have joked about the “hearies” habit of being distracted by sounds and looking around continuously. In a Deaf experience, distracting sounds are often nonexistent and so, it’s far easier to visually attune without anything else competing for attention. I realize I’m on a bit of a soap box here but in this age of multi-tasking, technology-pulling culture, it can be very unusual to keep our minds focused on one thing and one thing only—the conversation at hand. Mindfulness plays an enormous role in successfully utilizing context to understand the fingerspelling of my partner. Full, one hundred percent awareness of the other is a huge ingredient for success.	492	common-pile/libretexts_filtered	https://human.libretexts.org/Bookshelves/Languages/American_Sign_Language/Fingerspelling_-_A_Mindful_Approach_(Johnston)/06%3A_Context/6.01%3A_New_Page	libretexts	libretexts-0000.json.gz:38350	https://human.libretexts.org/Bookshelves/Languages/American_Sign_Language/Fingerspelling_-_A_Mindful_Approach_(Johnston)/06%3A_Context/6.01%3A_New_Page
duXKl9m--7ud6VBS	Canada and the Challenges of Leadership	2 “Upon Grounds Appealing to the Conscience of All Men” Laurier, Bowell, Tupper, and the Manitoba School Question Isaac Farrell Introduction: Few political issues have dominated Canadian politics to the degree that the Manitoba School Question did between 1890 and 1896. Centred around education funding for a French Catholic minority that was rapidly declining in both population and influence, the Manitoba School Question essentially began with the 1890 Manitoba Schools Act, which removed public funding from confessional schools and abolished the dual-denomination system.[1] However, due to its mishandling by a federal Conservative government that had been weakened by the death of Prime Minister John A. Macdonald, and growing tensions between Canada’s French and English-speaking populations, the Manitoba School Question quickly evolved from a regional dispute over language and education rights into a direct challenge on the national stage, with the constitutional authority of both the federal and provincial governments serving as the battlefield. The controversy was only heightened by subsequent actions taken by the government of Manitoba led by Premier Thomas Greenway, whose government acted to eliminate French as an official language in nearly every aspect of Manitoba life, including in its legislation.[2] The Manitoba School Question became a career-defining moment for several Canadian politicians as it grew in importance through two federal election campaigns and at least five separate federal mandates. For the governments of Prime Ministers Mackenzie Bowell and Charles Tupper, their inability to handle the situation spelled the premature end of their time in office and ultimately defined their legacies. On the other hand, no one benefited more from the Manitoba School Question than Liberal Party leader Wilfrid Laurier. Laurier’s skillful political maneuvering, highlighted by a series of colourful speeches in 1895 and 1896 in which he appealed to the “conscience of all men” and showed a willingness to take the “Sunny Way”[3] of political compromise, earned him the first of four majority election victories in 1896 and kickstarted the beginning of his record-setting fifteen consecutive years in office. The Laurier-Greenway Compromise followed five months later and ended the Manitoba School Question in the short term, but failed to address its underlying causes. However, it was also an early example of the diplomatic approach that would soon make Laurier a giant in Canadian politics for the rest of his life. Background History: Although the School Question officially began in 1890, its roots stretched back at least twenty years to the founding of Manitoba as a province. Changes in demographics were almost certainly the most significant cause of the crises. At the time of the Manitoba Act of 1870, the population in the province stood at roughly 12,000, of which fifty-four percent were French-speaking Metis.[4] Thus, when the first Manitoba School Act of 1871 regulated education under a Board of Education that was “divided” into two “largely autonomous”[5] Protestant and Catholic sections, a separate school system was not only sustainable but “absolutely necessary and logical.”[6] However, the population dynamics changed almost immediately, and within a decade there were more Manitobans who had been born in Ontario than those who were born in Manitoba.[7] By 1881, French speakers only represented twelve percent of Manitoba’s population, which had ballooned to over 65,000, of which “fewer than 10,000 were French.”[8] In the province’s largest settlement, Winnipeg, a city that grew from 700 in 1871 to 23,000 in 1891 and 200,000 by 1916, French speakers constituted less than five percent of the population by 1881.[9] By 1891, the membership of the Presbyterian, Methodist, and Anglican churches alone made up sixty-four percent of Manitoba’s population, while the Roman Catholic portion represented less than ten percent.[10] Thus, to the Anglo-Canadian majority, by 1875 the separate school system had become merely “convenient” to keep around, by 1878 it was a “nuisance,”[11] and by 1889 it was inefficient and unsustainable. After the North-West Territories Act failed to give French official status in 1875,[12] similar bills were introduced in Manitoba to repeal the separate school system as early as 1875 and 1876, and although they failed to gain momentum, a bill to remove French as an official language would have succeeded in 1879 if not for the presence of a French Catholic Governor General, who vetoed it.[13] Tensions only increased throughout the period, as the 1870s saw the highly-publicized Red River trials as well the movement of the anti-Catholic Orange Order into the province.[14] As a result, while French rights in Manitoba were not officially challenged again until 1889,[15] the wheels for a major conflict were already turning at least a decade earlier. Tensions between the two sides grew as the British nature of Western Canadian society became more pronounced after the 1885 North-West Rebellion and the subsequent execution of Louis Riel, which caused tensions between French and Anglo-Canadians to reach an all-time high. Anglo-Canadians felt betrayed by French Canada’s overwhelming support for both the rebellion and Riel,[16] and this sentiment led territorial politicians to try and do away with the French language and separate school guarantees across the country under the motto “one nation, one language.”[17] Newspapers such as the Brandon Sun and the Winnipeg Free Press were influenced by the gradual “influx” into the province of “numerically dominant, racially proud, and socially intolerant” British Protestants, who were “strongly supportive of both secular schools and the attempt to eliminate all cultural differences among the general population,”[18] and began to call for an end to the school system in late 1888 and, more frequently, after May 1889.[19] Thus, while the School Question may have come unexpectedly “out of a clear blue sky” to those outside Manitoba,[20] for Manitobans the process was a gradual “outgrowth of firmly entrenched local conditions.”[21] The Manitoba School Act and the Official Language Act: A new “local outgrowth” came with the appointment of new Liberal Premier Thomas Greenway in 1888. Greenway was asked to fill the position after Conservative Premier John Norquay was forced to resign in December 1887 due to his mishandling of Manitoba’s railway transfer crisis, and after Norquay’s initial replacement, David Howard Harrison, failed to form a new government within the first week of his appointment.[22] After his appointment, Greenway called and subsequently dominated a provincial election later that year, but as his government struggled to resolve those same railway transfer issues during the summer and winter of 1888,[23] Greenway needed a distraction. That distraction came as early as January and in the form of education reform. By that point, the strains of the separate school system were starting to become a matter of concern for the English-speaking and Protestant-believing majority, who had contributed an increasingly large portion of both the enrolment numbers and the taxes that went towards the school board.[24] Thus, in an announcement of a planned review of education funding, Greenway stated: “Owing to peculiar circumstances, the charge upon the taxpayers for educational purposes is abnormally heavy [and so] the Government will devise means whereby the schools will receive a much larger money grant than has heretofore been given.”[25] The concern of the majority grew into anxiety when the government review learned of a Catholic “contingency fund” that amounted to nearly $14,000.[26] This discovery caused the Catholic Section to fear for its future and the Protestant Section to believe their counterparts had “received favourable treatment in the distribution of government funds,” and thus this discovery arguably “marked the beginning of the Manitoba School Question.”[27] As a result, the Greenway government decided to “economize” by replacing the inefficient separate system with one that placed “Roman Catholic schools under much stricter control”[28] by “abolish[ing] the Board of Education and plac[ing] educational affairs directly under the administration of a minister of the crown,” a system similar to the one adopted in Ontario in 1876.[29] However, as this plan did not propose to remove religious education, it caused “considerable apprehension to the board and its two sections”[30] in roughly equal amounts. It was not until August that the debate turned towards abolishing Roman Catholic schools altogether, a turn that caused anxieties within the Roman Catholic community to reach a fever pitch. On 5 August 1889, D’alton McCarthy, a Conservative Member of Parliament visiting Manitoba and the North-West Territories from Ontario and a “spokesman for the Equal Rights Association,”[31] gave a speech in Portage la Prairie. In response to the 1888 Jesuit Estates Act, which monetarily reimbursed Jesuits in Québec for the land confiscations and cultural suppression that had been imposed on them by the British after 1763, the ardently anti-Catholic and anti-French McCarthy “encouraged his audience to support an attack on the French Roman Catholic minority” to resist similar “inequalities”[32] from occurring to the English of Manitoba and the North-West Territories. While McCarthy said nothing of the school system, his speech “vastly increased” the “tone and bitterness”[33] of the debate. Additionally, it was followed by a similar speech given by Manitoba Attorney General, Joseph Martin, in which Martin pledged that the Greenway government would put an end to both French as an official language and the separate school system in the province.[34] Initial Response to the Manitoba School Act: The Manitoba School Act and the Official Language Act were immensely popular with most Protestants and English Canadians,[35] not only in Manitoba — where they helped propel Greenway to another majority in 1892 — but also across Canada. Conversely, the opposite was true of French Canadians and Catholics. Backlash towards the two Acts came almost immediately, primarily from local French and Roman Catholic communities but also from Quebec, where the development took many by surprise and was perceived as a push towards making Western Canada, which at that time was seen as representing the future of Canada, culturally and linguistically English. However, as the community was pressed both by time and resources,[36] they were forced to choose between contesting the Official Language Act or the Manitoba School Act. As education was crucial to linguistic and religious retention, they chose the latter. Led by Archbishop Alexandre Tache of St. Boniface, Manitoba, and his “astute legal counsel,” J.S. Ewart,[37] the Roman Catholic community in the province first appealed to the Manitoba court system through Barrett v. the City of Winnipeg, a case in which Ewart represented John Barrett, a Winnipeg resident who “refused to pay the municipal tax for the support of the public schools … alleging that, as a Roman Catholic, his constitutional rights … were being violated.”[38] After Ewart lost in the first hearing, the case was appealed, first, to the Court of the Queen’s Bench of Manitoba, which found the Manitoba School Act to be intra vires, and then to both the Supreme Court and the federal government of Conservative Prime Minister John A. Macdonald, to whom they argued that the new public school system in Manitoba was “in reality a continuation of the Protestant school” system in the “guise” of a secular one, one in which Catholic children were forced to go to Protestant schools by the closing of Catholic schools. Thus, they argued that “only the Roman Catholics had been forced to make significant changes and endure hardships.”[39] Ewart claimed this made the “new laws unconstitutional”[40] under Section 23 of the Manitoba Act and Subsections 1 and 2 of Section 93 of the British North America Act, which included guarantees that established separate education rights for minorities in Upper and Lower Canada.[41] Ewart and Tache’s federal appeal was met more with “sympathy than direct action.”[42] Macdonald initially “refused to interfere with the school law of the province,”[43] and instead deferred becoming involved until the Judicial Committee of the Privy Council, the highest court in Canada at the time, made a decision. In his response, which McCarthy (who by then had switched allegiances to the Liberals) would later describe as the last action taken by the government which he could “commend,”[44] Macdonald said: If the appeal should be successful these acts will be annulled by judicial decision, the Roman Catholic minority in Manitoba will receive protection and redress. The acts purporting to be repealed will remain in operation… if the legal controversy should result in the decision… being sustained, the time will come for… the petitions which have been presented by and on behalf of the Roman Catholics of Manitoba for redress… under section 22 of the Manitoba Act… and which are analogous to the provisions made by the British North America Act.[45] Thus, Macdonald sent Ewart away with a promise that “if the law turned out to be within the constitutional power of the province to pass, the Government here would entertain the question”[46] in regards to the Manitoba constitution. This was a promise that would soon have drastic implications. After a separate hearing in 1891 on the Manitoba School Act, the Privy Council inconclusively ruled that “Manitoba had acted within its rights but that the federal government also had the right to issue its own replacement legislation” and that it had “affected the minority’s rights adversely.”[47] The issue was thereby pushed out of the courts and into the realm of politics.[48] Ewart and Tache turned once more to the Macdonald government, which responded by ordering the Greenway government to provide public support to the Catholic schools.[49] Greenway ignored the order, and the “legislation proposed by King’s government to address the issue was interrupted by the 1891 federal election,” because King was concerned that forcing the issue could potentially hurt his chances of re-election.[50] Macdonald defeated Leader of the Opposition Wilfrid Laurier, who was making his first election appearance, but it would be the last Conservative victory until 1911. The Manitoba School Question: Macdonald suffered an untimely stroke on May 27, the same day the Supreme Court first heard Ewart’s appeal in the Barrett case,[51] and died on June 6, only three months after the 1891 election. On October 28, Supreme Court sided with Ewart and against both the Manitoba government and the Manitoba courts, which they said had acted ultra vires.[52] This, too, was appealed to the Privy Council with a hearing set for 1892, and as the country awaited the Council’s decision, debates over the Manitoba School Question stalled.[53] By the time the Barrett decision finally came in mid-1892 and handed the problem back to the federal government,[54] the health of Macdonald’s successor, John Abbott, was already in decline,[55] putting the Conservative Party in a state of unstable leadership for the first time in decades. Abbott resigned in November and was replaced by John Thompson, who was the first Catholic Prime Minister;[56] this soon became a matter of particular contention regarding the School Question, as he had converted from Protestantism as an adult.[57] Thompson’s first action was to appeal to the Privy Council once again,[58] this time through Brophy v. the Attorney-General of Manitoba. His second action was to force his government to “reluctantly [take] a stand”[59] against the Manitoba government. However, what that stand would look like was yet to be determined. On 28 November, the Ottawa World captured Thompson’s lack of clarity, as well as the total uncertainty which surrounded the case, with the following: Sir John Thompson… is unpledged publicly or privately in the matter, and he is not now going to pledge himself or his party on a question that cannot come up as a political issue for a few years [due to the Brophy case]… For the present, separate schools for Manitoba are impossible, and the Roman Catholics must accept it as such. This really relieves [Thompson] and his party of a troublesome question and gives him a free hand.[60] As the debate over the School Question centred around the intentions behind the making of Section 93 of the British North America Act, politicians from both parties did their best to challenge the clarity of the constitutional guarantees. The issue stemmed from whether or not the guarantees covered religious minorities across the country or solely those in Ontario and Quebec, and whether or not the provincial governments had the power to revoke those guarantees.[61] These guarantees were, in fact, “explicit and unambiguous,” as the Official Language Act was eventually ruled unconstitutional in 1979,[62] and the Manitoba Act only succeeded because “notions of constitutionalism and ‘constitutional guarantees’ were vague and subject to a variety of interpretations.”[63] Those interpretations often centred around racial stereotypes, with the intellectual capacity of the Métis involved in the drafting of the Manitoba Act being questioned. For example, Bishop A.B. Bethune of Toronto based his argument against the Metis on a description from 1871: “The French half breed, called also Métis… is an athletic, rather good-looking, lively, excitable, easy-going being. Fond of a fast pony, fond of merry-making, free-hearted, open-handed, yet indolent and improvident, he is a marked feature of border life.” It is this wild and intractable, but still attractive, child of the plains who, we are asked to believe, was so calculatingly solicitous to secure the permanency of Roman Catholic separate schools. “As different as is the patient roadster from the wild mustang, is the English-speaking half-breed from the Métis.”[64] Early on, opposition leader Wilfrid Laurier was critical of the Conservative Government’s handling of the case, but he did not become directly involved. However, when discussions over a potential remedial order started to dominate Parliament in the spring of 1893, Laurier chose to pressure the government on the issue, starting with a speech given to Parliament in March 1893.[65] Framing the situation as the “simplest issue” and one in which the government simply needed to “express an opinion” one way or the other, Laurier “arraign[ed] [the] government for their arrant cowardice,” an expression he claimed was in no way “too strong” in the face of such “flimsiness” on behalf of the Conservatives.[66] Laurier claimed the Conservatives had avoided taking a stance on the issue for over three years when he could have addressed it in only one, which Laurier said proved there was not “in this government the courage equal to the duty of the hour.”[67] Laurier then accused Thompson of personally avoiding the issue, and sarcastically commended Thompson for his ability to “speak for two hours without having told the House what his policy was.”[68] While he described Thomas as an “able lawyer”[69] whose legal skills were well-known, Laurier argued that Thompson should have been disqualified from being involved in the case due to his personal history with both religions.[70] He also used the opportunity to begin discrediting the Conservative ministers tasked with handling the School Question. This included Mackenzie Bowell, the Minister of Trade and Commerce and a newspaper publisher, who had allegedly “never distinguished [himself] by [his] legal studies.”[71] Using his legal background to full effect, Laurier framed the Manitoba School Question as a straightforward question of provincial versus minority rights, with his speech structured to sound like he already had a solution to the problem.[72] However, he did so without disclosing which side he agreed with. Comparing the situation of the French in Manitoba to that of the English Protestants in Québec, Laurier opined that the Fathers of Confederation had intended to ensure minority rights and that they not only guaranteed a separate school system but also separate school boards, saying “if the Catholic claim is true, though my life as a political man should therefore be ended forever… the minority has been subjected to a most infamous tyranny.”[73] However, he also reminded Parliament that the BNA Act empowered local legislatures to be “almost independent” in most policy areas and that in the case of separate schools, the federal government held only a “supervisory power.”[74] This was the limit to which Laurier was willing to commit. While he agreed that the Catholics had the right to appeal and that the government was failing in its duty to honour that appeal, Laurier did not outright support the Catholics, and in fact, expressed sympathy for Greenway. He was also careful not to criticize the late Macdonald, instead highlighting how the high-ranking members of the Conservative Party had failed to follow the groundwork Macdonald had set on the issue: Laurier recalled that the Catholics had been instructed by Macdonald to appeal to the courts first, and if they failed, Macdonald had promised them his government was “endowed with judicial powers” and could “sit as a court”[75] on their issue. Thus, Laurier contended that the Conservatives had an obligation to the Catholics even after Macdonald’s death, and went so far as to accuse the government of “resort[ing] to every possible subterfuge in order to avoid coming to a decision.”[76] The Conservatives may have underestimated the significance of the Manitoba School Question, but Laurier made it clear he did not. In his closing remarks, Laurier blamed the governments of both Abbot and Thompson for “even now not having done sooner what they should have done” before going on to predict that, whenever the government “at last” made a decision, “the population will by that time have been excited to such a pitch that the condition will be scarcely distinguishable from open rebellion to the law… and when that decision comes… great disappointment is sure to result, and an impression will prevail that a great injustice has been done.”[77] Therefore, in using the case of the Catholics to appeal to the moral and religious fibre of every man in Parliament, Laurier, who had already made significant gains in the 1891 federal election, was setting the groundwork for his 1896 campaign. The Conservative response to Laurier’s remarks was lacklustre, and further development throughout 1893 and 1894 was limited to debating the viability of a remedial order while the country waited on the Brophy case. The remedial order, which would theoretically force the Manitoba government to repeal both the Official Language Act and the School Act, was an issue that the Liberals adamantly opposed and that the Conservatives were split over. Matters were further complicated when Thompson suddenly and unexpectedly died at the age of 49 in December 1894, only a month before the Brophy decision was to be delivered. While Charles Tupper, High Commissioner to the United Kingdom, was believed to be the candidate best suited to be Thompson’s replacement, a combination of his “ill health” and the fact that “Governor General Lord Aberdeen and his influential wife disliked him,”[78] caused Mackenzie Bowell to become Prime Minister instead. That decision would soon prove to be a costly one. The Election of 1896: On 31 January 1895, the Privy Council ruled the Manitoba School Act constitutional but confirmed that, through a remedial order, the federal government was responsible for protecting the Catholic minority of Manitoba.[79] After deliberating on the decision for nearly two months, the Bowell government controversially issued a remedial order on 21 March demanding the Manitoba government to “restore the educational rights of its Catholic decisions”[80] that had been in place before 1890, a decision fervently critiqued by Laurier’s Liberals.[81] After discussions with Martin and the rest of his cabinet that lasted another two months, Greenway rejected the remedial order on 5 June. Greenway argued that the inefficiencies of the separate system made it impossible to comply, but that “with more information and negotiation, some compromise could be reached.”[82] Bowell now had a full-blown crisis on his hands. Greenway’s refusal was a direct challenge to federal authority, but as Bowell’s party had already been split on the issue even before the remedial order, his options were limited. In July, Senator Auguste-Real Angers, Bowell’s Minister of Agriculture and a key representative from Quebec, handed in his resignation, and with two other French Canadian ministers threatening to do the same, Bowell was unable to replace him.[83] By December, “the government had lost two critical by-elections in Quebec over the school issue… and Nathaniel Clarke Wallace… the great anti-remedial in the ministry, had resigned.”[84] When another remedial bill was introduced to Parliament in January 1896, seven more threatened to resign from their cabinet positions if Bowell was not replaced by Tupper (and then temporarily did),[85] and, with his government falling apart around him, Bowell attempted to resign several times. However, since Tupper was still the clear choice to succeed him, these attempts were all rejected by Aberdeen. Ever the politician, Laurier used this opportunity to transform his criticisms into an electoral strategy throughout 1895. With the Conservatives less unified than ever over the remedial order and with their 1891 mandate nearing its end, Laurier launched his election campaign with a speaking tour in the fall.[86] The tour peaked on 8 October, when Laurier gave what would become among the most famous speeches in Canadian history and the one that would most define his legacy: the “Sunny Way” speech. After stating that he was “not here to solve the question, because it [was] not in [his] province to solve it” but that he was not “afraid” to speak on it, Laurier invoked an Aesopean fable “in which the sun, representing kindness, and the wind, representing severity, [held] a contest”[87] to remove a traveller’s cloak by either warming them so that they willingly removed the coat or by blowing it off of them. Framing the Conservatives as the wind and Greenway as the traveller, Laurier vowed to try “the sunny way,” saying: I would approach Greenway with the sunny ways of patriotism, asking him to be generous to the minority, in order that we may have peace amongst all the creeds and races… Do you not believe that there is more to be gained by appealing to the heart and soul of men rather than compelling them to do a thing? I intend to do so… to satisfy… every sensible man. [Greenway], I will meet you halfway.[88] While Laurier continued to play his hand close to the chest by not “leaving the lines” until it was advantageous to do so,[89] his intent was clear: he was extending an olive branch to Greenway in the form of compromise. The response to this speech was rapturous, and from then on Laurier had a clear advantage heading into 1896. By this point, popular sentiment for English Canada had adopted the mantra that “the Manitobans of 1870 had no right to bind the Manitobans of 1895,”[90] and so in issuing the remedial order Bowell had surrendered much of the English vote. However, it had also taken so long for the Conservatives to adopt a stance that in their indecisiveness, they had already lost Quebec as well.[91] By March of 1896, Laurier was adamant in placing the blame entirely on Bowell, and it seemed the rest of the country agreed. On 3 March, Laurier gave another powerful speech, in which he committed to taking a stand “not upon grounds of Roman Catholicism, not upon grounds of Protestantism, but upon grounds which can appeal to the conscience of all men… upon grounds which can be occupied by all men who love justice, freedom, and toleration.”[92] The reaction to Laurier’s speech was once again overwhelming, and with the time since the last election fast approaching the five-year mark, Aberdeen’s hand was forced. The government called for a new election on the 25th, and the next day, Bowell’s resignation was finally accepted.[93] Tupper had less than three months to campaign before the election, and with the remedial order on hold, the impending election essentially became a referendum on the issue. Throughout the campaign, Laurier blasted the Tupper government for not “issuing a commission to ascertain the facts of the case,” claiming it was “impossible” to deal with this question without an investigation.[94] In response, Tupper argued that notion had been “completely swept to the wind”[95] by his government. He justified the lack of an investigation, and also the Conservative’s refusal to negotiate with Greenway directly, by arguing Manitoba had forfeited its exclusive jurisdiction over education when it “legislated to take away the rights or privileges enjoyed by the minority as they had existed”[96] before 1890. On 14 April, Laurier promised that “if the People of Canada, carry me to power … I will settle this question to the satisfaction of all the parties interested … I assure you that I will succeed in satisfying those who suffer at present,”[97] and carry Laurier they did. While Tupper put together a remarkably strong campaign and even managed to claw back enough of the electorate to win the popular vote 46 to 45 percent,[98] the damage had already been done. Laurier easily won the seat count, and the election saw the Liberals achieve a swing of fifty-eight seats over the Conservatives, with Quebec carrying the election by “giving sixteen seats to the bishops” and the other “forty-nine to Laurier.”[99] With the election finally out of the way, Laurier wasted no time in reaching out to Greenway, and over the summer and fall of 1896 the two sides negotiated a compromise. When the provincial and federal governments finally agreed to the Laurier-Greenway Compromise on 16 November 1896, the political hotbed surrounding the Manitoba School Question came to a rather abrupt end. Among several other things, the Compromise “contained a provision allowing instruction in a language other than English in bilingual schools” where enough students spoke the language, allowed Catholic teachers to be employed in schools with at least forty Catholic children, and allowed religious instruction for the last half hour of each day.[100] Historical Significance: For all the trouble it had caused Canadian politicians, the controversy surrounding the Manitoba School Question was all but settled by the end of the year. The Compromise did little to satisfy Catholics in Manitoba and to even get the Catholic Church to accept the Compromise, Laurier had to first appeal to the Pope. However, as far as the rest of the country was concerned, the Manitoba School Question had been answered. What officially began in 1890 as a provincial issue over education and taxation bylaws soon evolved into a fierce debate over the role that the majority and minority, the Protestant and the Catholic, and the Anglophone and the Francophone would each play in Canada’s future. It was a debate that was just as much about the future status of language, religion, and culture as it was about education and one just as much about the constitutional relationship between the provincial and federal levels of government as it was about the relationship between Manitoban Roman Catholics and Protestants. The influence that the Manitoba School Question had on Canadian politics during the 1890s is rivalled by only a handful of issues in Canadian history. It defined the politics of Manitoba throughout the decade, and as early as 1893, it had become the most pressing political concern in the country. Politically, the Manitoba School Question and the election it defined marked a significant crossroads in Canadian history. Disagreements over how to respond to the Question caused the Conservative Party to internally split in two, especially after the death of John A. Macdonald left the party without a clear leader for the first time in decades. It impacted the political careers of countless politicians, including at least two provincial premiers and five Prime Ministers, and it gave birth to the mandates of Tupper, Bowell, and Laurier, while also ending the mandates of the first two. Laurier’s victory in the 1896 election conclusively ended the Macdonald era and the Conservative Party dominance that had defined Canada for much of its early history. It also marked the beginning of a new era, one defined by Laurier’s record of fifteen consecutive years holding the office of the Prime Minister. The “Sunny Way” promised by Laurier in 1895 and 1896 and implemented throughout negotiations for the Laurier-Greenway Compromise was, in many ways, an early glimpse into what this time in office would look like, and Tupper’s inability to regain Canada’s confidence in the election of 1900 paved the way for Robert Borden to become the leader of the Conservative Party in 1901. It also had a significant impact on the provincial level: in Manitoba, English soon became the official language of the province with 1899’s Manitoba Language Act, and the already diminishing presence of dedicated French-language education all but vanished in the province as a result. With the national focus being placed on Manitoba for the better part of a decade, the School Question perhaps represents the province at its most relevant to national politics, and this relevance indicated the increasingly important role the Prairies would play for the next thirty-odd years as it became one of Canada’s fastest-growing regions. The concessions made in the Laurier-Greenway Compromise eventually resurfaced in the Manitoba provincial election of 1900, as the Compromise’s unpopularity was among the many reasons that Greenway was voted out. The failure of the Compromise to provide a viable framework for minority education in other provinces, in conjunction with Laurier’s unwillingness to take a firm stance on the matter, had repercussions that lasted for decades and affected several provinces. The issues of education funding, control over curriculum, and segregation of schools for religious and linguistic minorities resurfaced less than a decade later, first in the negotiations for founding Alberta and Saskatchewan in 1905,[101] again in 1911 with Ontario’s Regulation 17, and finally in 1916 when the Manitoba School Question resurfaced for the second -but arguably not final- time under future Prime Minister Borden.[102] Conclusion: The political contexts that made the Manitoba School Question relevant in the 1890s inevitably faded with time, and in retrospect, the situation pales in severity to many of the other crises Canadian Prime Ministers have faced that are covered elsewhere in this textbook, including the related Conscription Crisis covered by Stephen Lylyk. Indeed, the Manitoba School Question was not the first political crisis to prematurely end a Prime Minister’s career or dominate an election. It was not the first to deal with the growing divides within Canada: between French and English, Protestant and Catholic, ‘West’ and ‘East,’ and provincial and federal government. It was not the first issue related to linguistic and education rights, or even with the French in Manitoba alone. Nor would it be the last — or the most significant — instance of these issues challenging Canadian Prime Ministers. For these reasons and more, while the Manitoba School Question attracted “considerable attention” from Canadian historians in the first half of the twentieth century, the subject has been mostly overlooked over the last fifty years. However, the Manitoba School Question was unique in that it was essentially the first to encapsulate nearly all of these topics — which together account for many of the biggest political challenges in Canadian history — in a single political controversy. It was also the first, and to date, the only federal election predicated on a court decision, and this decision not only “vindicated [the Supreme Court] as a truly impartial court of justice”[103] but set a precedent for the future of provincial-federal relations. In this way, the Manitoba School Question and the 1896 election marked a significant moment in Canadian history and served as a precursor for many of the religious, linguistic, and cultural divides that would define Canada in the twentieth century. It is also a reminder of what a single individual who is willing to compromise can accomplish, of the ramifications such compromises can have, and perhaps that is what makes the Manitoba Schools crisis still worth studying today. - Alan H. Child, “The Board of Education, Joseph Martin, and the Origins of the Manitoba School Question: A Footnote,” Canadian Journal of Education Vol. 2, no. 3 (1977), 37. ↵ - “Official Language Act (1890).” Compendium of Language Management in Canada. University of Ottawa. https://www.uottawa.ca/clmc/official-language-act-1890. ↵ - Jamie Bradburn. “‘Try the sunny way’: How Laurier and the Liberals ended 18 years of Conservative rule.” TVOntario Today. September 9, 2021. ↵ - A.B. Bethune, “Is Manitoba Right?” A Question of Ethics, Politics, Facts, and Law. A Complete Historical and Controversial Review of the Manitoba School Question. (Winnipeg, Manitoba: Tyre Bros Printers, May 18, 1896). 18. ↵ - Child, 1. ↵ - Nelson Wiseman. “The Questionable Relevance of the Constitution in Advancing Minority Cultural Rights in Manitoba.” Canadian Journal of Political Science 25, no. 4 (1992): 700. http://www.jstor.org/stable/3229684. ↵ - Ibid., 701. ↵ - Ibid., 705. ↵ - Ibid., 701. ↵ - Christopher Hackett, The Anglo-Protestant Churches of Manitoba and the Manitoba School Question. (Winnipeg: University of Manitoba, 1988), 4. ↵ - Wiseman, 700. ↵ - Bill Waiser, “Teaching the West and Confederation: A Saskatchewan Perspective.” The Canadian Historical Review 98, no. 4 (2017): 756. ↵ - Wiseman, 700. ↵ - J.R Miller, “D’Alton McCarthy, Equal Rights, and the Origins of the Manitoba School Question.” The Canadian Historical Review 54, no. 4, (December 1973), 381. ↵ - Wiseman, 698-700. ↵ - Waiser, 753. ↵ - [17] Ibid., 757. ↵ - Wiseman, 699. ↵ - Miller, “D’Alton McCarthy, Equal Rights, and the Origins of the Manitoba School Question,” 385. ↵ - Hackett, 10. ↵ - Ibid., 150. ↵ - J.E. Rea, “Greenway, Thomas,” in Dictionary of Canadian Biography, vol. 13. (University of Toronto/Université Laval, 2003). http://www.biographi.ca/en/bio/greenway_thomas_13E.html ↵ - Ibid. ↵ - Child, 39. ↵ - Ibid., 38. ↵ - Ibid., 41. ↵ - Ibid. ↵ - D.J. Hall, Clifford Sifton, Volume 1: The Young Napoleon, 1861-1900. (Vancouver, CA: UBC Press, 1981), 42. ↵ - Child, 38. ↵ - Ibid., 41. ↵ - Hackett, 9. ↵ - Ibid. ↵ - Child, 58. ↵ - Hackett, 10, ↵ - Wiseman, 699. ↵ - Hackett, 12. ↵ - Ibid. ↵ - Richard A. Olmsted, Decisions of the Judicial Committee of the Privy Council Relating to the British North America Act, 1867 and the Canadian Constitution 1867-1954, Vol. 1, Ottawa, Department of Justice, 1954, 739p., pp. 272. ↵ - Hackett, 10-1. ↵ - Ibid., 48. ↵ - Wiseman, 697. ↵ - Ibid., 14. ↵ - House of Commons Debates: Speech of Mr. D'Alton McCarthy, M.P., on the Manitoba school question. 7th Parl, 5th Sess, Wednesday, 16 July, 1895. CIHM/ICMH microfiche series; no. 33947, 1. ↵ - Ibid., 39. ↵ - Canada, Parliament, House of Commons Debates: Speech of Mr. Laurier, M.P., on Separate Schools in Manitoba. 7th Parl, 1st Sess, (Ottawa: Printer S.E. Dawson, Wednesday, 8th March 1893). CIHM/ICMH microfiche series; no. 46308., 12 ↵ - Ibid. ↵ - Child, 37. ↵ - House of Commons Debates: Speech of Mr. D'Alton McCarthy, M.P., on the Manitoba School Question, 2. ↵ - Child, 58. ↵ - Ibid. ↵ - Gordon Bale, “Law, Politics and the Manitoba School Question: Supreme Court and Privy Council, 1985,” Canadian Bar Review 63-3 (Sept. 1985). 476 ↵ - Ibid. ↵ - Ibid., 479-84. ↵ - Ibid., 493 ↵ - Carman Miller, “Abbott, Sir John Joseph Caldwell,” in Dictionary of Canadian Biography, vol. 12. (University of Toronto/Université Laval, 2003). http://www.biographi.ca/en/bio/abbott_john_joseph_caldwell_12E.html. ↵ - P. B. Waite, “Thompson, Sir John Sparrow David,” in Dictionary of Canadian Biography, vol. 12. (University of Toronto/Université Laval, 2003). ↵ - Ibid. ↵ - Ibid. ↵ - Hackett, 14. ↵ - “The Manitoba School Question.” The Ottawa World, November 28th, 1892. 2. ↵ - Bale, 485-97. ↵ - Wiseman, 697. ↵ - Ibid., 704. ↵ - Bethune, 19. ↵ - Canada, Parliament, House of Commons Debates: Speech of Mr. Laurier, M.P., on Separate Schools in Manitoba. 7th Parl, 1st Sess, (Ottawa: Printer S.E. Dawson, Wednesday, 8th March 1893). CIHM/ICMH microfiche series; no. 46308., 12 ↵ - House of Commons Debates: Speech of Mr. Laurier, M.P., on Separate Schools in Manitoba, 1-3. ↵ - Ibid., 59. ↵ - Ibid., 3. ↵ - Ibid., 9. ↵ - Ibid. ↵ - Ibid., 13. ↵ - House of Commons Debates: Speech of Mr. Laurier, M.P., on Separate Schools in Manitoba, 3. ↵ - Ibid., 10-1. ↵ - Ibid., 4. ↵ - Ibid., 12. ↵ - Ibid.,11. ↵ - House of Commons Debates: Speech of Mr. Laurier, M.P., on Separate Schools in Manitoba, 14. ↵ - Phillip Buckner, “Tupper, Sir Charles,” in Dictionary of Canadian Biography, vol. 14, (University of Toronto/Université Laval, 2003), accessed April 3rd, 2023. ↵ - Bale, 503. ↵ - Ibid. ↵ - “Opinions of Liberal members on Manitoba School Bill: from "Hansard" of 1896. Canadiana CIHM/ICMH microfiche series no. 11437. http://online.canadiana.ca/view/oocihm.11437. 2-4. ↵ - Waite, “Bowell, Sir Mackenzie.” Dictionary of Canadian Biography.” Accessed April 10, 2023. http://www.biographi.ca/en/bio/bowell_mackenzie_14E.html. ↵ - Buckner. ↵ - Ibid. ↵ - Ibid. ↵ - Bradburn. ↵ - Nelle Oosterom, “A Day For Laurier,” Canada's History. September 12, 2016. ↵ - Arthur Milnes, "Wilfrid Laurier: “The Sunny Way” Speech, 1895." The Canadian Encyclopedia. Historica Canada. Article published July 12, 2017; Last edited July 12, 2017. ↵ - Ibid. ↵ - Wiseman, 704. ↵ - Buckner. ↵ - Bradburn. ↵ - Buckner. ↵ - Speech of Sir Charles Tupper, M.P., on the Winnipeg Negotiations. (7th Parl, 6th Sess, 14th April, 1896). CIHM/ICMH microfiche series; no. 900562, 8 https://www.canadiana.ca/view/oocihm.46308/1 ↵ - Ibid., 2. ↵ - Ibid. ↵ - Bruce Cherney, Bruce. "Manitoba School Question - Controversy Threatened to Tear Nation Apart,” Winnipeg Regional Real Estate News. March 30, 2007, https://www.winnipegregionalrealestatenews.com/publications/real-estate-news/616. ↵ - Buckner. ↵ - Ibid. ↵ - “Laurier-Greenway Compromise.” Compendium of Language Management in Canada, University of Ottawa. https://www.uottawa.ca/clmc/laurier-greenway-compromise-1896. ↵ - “Language Debate Rages On.” The Daily Herald, November 4, 1905, 2. ↵ - Hackett, 16. ↵ - Bale, 518. ↵	8,889	common-pile/pressbooks_filtered	https://opentextbooks.uregina.ca/primeministersandcrisis/chapter/upon-grounds-appealing-to-the-conscience-of-all-men-laurier-bowell-tupper-and-the-manitoba-school-question/	pressbooks	pressbooks-0000.json.gz:39301	https://opentextbooks.uregina.ca/primeministersandcrisis/chapter/upon-grounds-appealing-to-the-conscience-of-all-men-laurier-bowell-tupper-and-the-manitoba-school-question/
v-oh7ExOkogmRDDE	Physics II	3 Conductors and Insulators Learning Objectives By the end of this section, you will be able to: - Define conductor and insulator, explain the difference, and give examples of each. - Describe three methods for charging an object. - Explain what happens to an electric force as you move farther from the source. - Define polarization. Some substances, such as metals and salty water, allow charges to move through them with relative ease. Some of the electrons in metals and similar conductors are not bound to individual atoms or sites in the material. These free electrons can move through the material much as air moves through loose sand. Any substance that has free electrons and allows charge to move relatively freely through it is called a conductor. The moving electrons may collide with fixed atoms and molecules, losing some energy, but they can move in a conductor. Superconductors allow the movement of charge without any loss of energy. Salty water and other similar conducting materials contain free ions that can move through them. An ion is an atom or molecule having a positive or negative (nonzero) total charge. In other words, the total number of electrons is not equal to the total number of protons. Other substances, such as glass, do not allow charges to move through them. These are called insulators. Electrons and ions in insulators are bound in the structure and cannot move easily—as much as 1023 times more slowly than in conductors. Pure water and dry table salt are insulators, for example, whereas molten salt and salty water are conductors. Charging by Contact Figure 2 shows an electroscope being charged by touching it with a positively charged glass rod. Because the glass rod is an insulator, it must actually touch the electroscope to transfer charge to or from it. (Note that the extra positive charges reside on the surface of the glass rod as a result of rubbing it with silk before starting the experiment.) Since only electrons move in metals, we see that they are attracted to the top of the electroscope. There, some are transferred to the positive rod by touch, leaving the electroscope with a net positive charge. Electrostatic repulsion in the leaves of the charged electroscope separates them. The electrostatic force has a horizontal component that results in the leaves moving apart as well as a vertical component that is balanced by the gravitational force. Similarly, the electroscope can be negatively charged by contact with a negatively charged object. Charging by Induction It is not necessary to transfer excess charge directly to an object in order to charge it. Figure 3 shows a method of induction wherein a charge is created in a nearby object, without direct contact. Here we see two neutral metal spheres in contact with one another but insulated from the rest of the world. A positively charged rod is brought near one of them, attracting negative charge to that side, leaving the other sphere positively charged. This is an example of induced polarization of neutral objects. Polarization is the separation of charges in an object that remains neutral. If the spheres are now separated (before the rod is pulled away), each sphere will have a net charge. Note that the object closest to the charged rod receives an opposite charge when charged by induction. Note also that no charge is removed from the charged rod, so that this process can be repeated without depleting the supply of excess charge. Another method of charging by induction is shown in Figure 4. The neutral metal sphere is polarized when a charged rod is brought near it. The sphere is then grounded, meaning that a conducting wire is run from the sphere to the ground. Since the earth is large and most ground is a good conductor, it can supply or accept excess charge easily. In this case, electrons are attracted to the sphere through a wire called the ground wire, because it supplies a conducting path to the ground. The ground connection is broken before the charged rod is removed, leaving the sphere with an excess charge opposite to that of the rod. Again, an opposite charge is achieved when charging by induction and the charged rod loses none of its excess charge. Neutral objects can be attracted to any charged object. The pieces of straw attracted to polished amber are neutral, for example. If you run a plastic comb through your hair, the charged comb can pick up neutral pieces of paper. Figure 5 shows how the polarization of atoms and molecules in neutral objects results in their attraction to a charged object. When a charged rod is brought near a neutral substance, an insulator in this case, the distribution of charge in atoms and molecules is shifted slightly. Opposite charge is attracted nearer the external charged rod, while like charge is repelled. Since the electrostatic force decreases with distance, the repulsion of like charges is weaker than the attraction of unlike charges, and so there is a net attraction. Thus a positively charged glass rod attracts neutral pieces of paper, as will a negatively charged rubber rod. Some molecules, like water, are polar molecules. Polar molecules have a natural or inherent separation of charge, although they are neutral overall. Polar molecules are particularly affected by other charged objects and show greater polarization effects than molecules with naturally uniform charge distributions. Check Your Understanding Can you explain the attraction of water to the charged rod in Figure 6? Solution Water molecules are polarized, giving them slightly positive and slightly negative sides. This makes water even more susceptible to a charged rod’s attraction. As the water flows downward, due to the force of gravity, the charged conductor exerts a net attraction to the opposite charges in the stream of water, pulling it closer. PhET Explorations: John Travoltage Make sparks fly with John Travoltage. Wiggle Johnnie’s foot and he picks up charges from the carpet. Bring his hand close to the door knob and get rid of the excess charge. Section Summary - Polarization is the separation of positive and negative charges in a neutral object. - A conductor is a substance that allows charge to flow freely through its atomic structure. - An insulator holds charge within its atomic structure. - Objects with like charges repel each other, while those with unlike charges attract each other. - A conducting object is said to be grounded if it is connected to the Earth through a conductor. Grounding allows transfer of charge to and from the earth’s large reservoir. - Objects can be charged by contact with another charged object and obtain the same sign charge. - If an object is temporarily grounded, it can be charged by induction, and obtains the opposite sign charge. - Polarized objects have their positive and negative charges concentrated in different areas, giving them a non-symmetrical charge. - Polar molecules have an inherent separation of charge. Conceptual Questions - An eccentric inventor attempts to levitate by first placing a large negative charge on himself and then putting a large positive charge on the ceiling of his workshop. Explain. - If you have charged an electroscope by contact with a positively charged object, describe how you could use it to determine the charge of other objects. Specifically, what would the leaves of the electroscope do if other charged objects were brought near its knob? - When a glass rod is rubbed with silk, it becomes positive and the silk becomes negative—yet both attract dust. Does the dust have a third type of charge that is attracted to both positive and negative? Explain. - Why does a car always attract dust right after it is polished? (Note that car wax and car tires are insulators.) - Describe how a positively charged object can be used to give another object a negative charge. What is the name of this process? - What is grounding? What effect does it have on a charged conductor? On a charged insulator? Problems & Exercises - Suppose a speck of dust in an electrostatic precipitator has 1.0000 × 1012 protons in it and has a net charge of –5.00 nC (a very large charge for a small speck). How many electrons does it have? - An amoeba has 1.00 × 1016 protons and a net charge of 0.300 pC. (a) How many fewer electrons are there than protons? (b) If you paired them up, what fraction of the protons would have no electrons? - A 50.0 g ball of copper has a net charge of 2.00 μC. What fraction of the copper’s electrons has been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.) - What net charge would you place on a 100 g piece of sulfur if you put an extra electron on 1 in 1012 of its atoms? (Sulfur has an atomic mass of 32.1.) - How many coulombs of positive charge are there in 4.00 kg of plutonium, given its atomic mass is 244 and that each plutonium atom has 94 protons? Glossary free electron: an electron that is free to move away from its atomic orbit conductor: a material that allows electrons to move separately from their atomic orbits insulator: a material that holds electrons securely within their atomic orbits grounded: when a conductor is connected to the Earth, allowing charge to freely flow to and from Earth’s unlimited reservoir induction: the process by which an electrically charged object brought near a neutral object creates a charge in that object polarization: slight shifting of positive and negative charges to opposite sides of an atom or molecule electrostatic repulsion: the phenomenon of two objects with like charges repelling each other Selected Solutions to Problems & Exercises 1. 1.03 × 1012 3. 9.09 × 10−13 5. 1.48 × 108 C	2,137	common-pile/pressbooks_filtered	https://library.achievingthedream.org/austinccphysics2/chapter/18-2-conductors-and-insulators/	pressbooks	pressbooks-0000.json.gz:85117	https://library.achievingthedream.org/austinccphysics2/chapter/18-2-conductors-and-insulators/
BTY8qnjteIo19VnH	The evolution of man; a popular scientific study, by Ernst Haeckel. Tr. from the 5th (enl.) ed. by Joseph McCabe.	S00260311 D This BOOK may be kept out TWO WEEK ONLY, and is subject to a fine of FIV: CENTS a day thereafter. It is due on ih day indicated below: rial.- II. Gastrulation 01 Holoblastic Animals (with total segmentation) ---... Explanation p. 170 Plate III. Gastrixation >>i Mesoblasth Animals (with partial segmentation) ----.. Explanation p. 17.1 Plate IV. Sandal-Shaped Embryos 01 Three Sauropsids (lizard, Plate VI. Transversi mmiunm'! V'er ;\ii Embryos. Diagrammatic, germ-layers coloured - - -Explanation pp. 326 j2g Plate VII. Longitudinal Sections .>i V'ertebrati Embryos. Diagrammatic, germ-layers coloured - - -Explanation pp. 326-329 Plate \ III. Embryos Of Three Reptiles (lizard, serpent, crocodile) at WHEN the first edition of this work appeared in 1874, and the third edition followed three years afterwards, the circumstances of biologv were very different from what they are to-day. It is true that the struggle for the recognition of the great truths of science, which Darwin had initiated by the publication of his epoch-making work in 1859, had already been decided in his favour on the main issue. But the most important consequence of the new evolutionary doctrine (now firmly established for the first time through his theory of selection) — that is to say, its application to man— still met with the most spirited and widespread opposition. I had in my Generelle Morphologies published in 1866, made the first attempt to trace the series of man's ancestors, and to indicate the several stages of animal organisation which led up to his appearance ; and I had continued this task in my History of Creation, published in 1868. The profound importance that the facts of human embryology have in the attempt to construct our ancestral tree became more and more evident to me. A prolonged study of human embryology, and the giving of university lectures on this first base of physical anthropology, emboldened me to attack the difficult task of applying it to the history of our species. The complete application to man of the first law of biogeny seemed to me the more useful and desirable as the great majority of embrvologists at that time knew nothing about it. The only work that dealt comprehensively with human embryology after 1859 — namelv, Albert Kolliker's widely-circulated Manual — took an entirely opposite view ; even in the latest edition (1884) the distinguished author adheres to the opinion that " the laws governing the evolution of living things are still wholly unknown ; it is believed that the development took place by abrupt stages rather than by a continuous growth, as the Darwinians imagine." In opposition to this dualistic idea that was then prevalent on all sides, I attempted in 1874 to obtain a hearing for my monistic conception of the embryological phenomena. I started from the following general principles : — 1. There is a direct causal connection between the observed facts of human embryology and the theoretical ancestry of our race, which, for obvious reasons, for the most part lies outside our sphere of observation. 2. This mechanical causal nexus finds its simplest expression in the fundamental law of biogeny: "Ontogeny is a brief and imperfect recapitulation of phylogeny." ' 3. The phylogenetic process, or the gradual development of man's higher vertebral ancestors through a long series of lower animal forms, is a very complex historical fact, due to a manifold play of heredity and adaptation. 4. Each one of the processes involved depends on the physiological functions of the organism, and can be traced to the action of either reproduction (heredity) or nutrition (adaptation). 5. The fact of human embryology can only be explained as the inheriting of phylogenetic (ancestral) forms, in which the palingenetic phenomena are to be carefully distinguished from the cenogenetic.2 6. Only the palingenetic phenomena (that is to say, such reminiscences of earlier stages as the temporary formation of the spinal cord, the primitive kidneys, or the gill-clefts) are of direc' interest in the tracing of our animal ancestors, because they are due to the inheritance of adaptive structures in earlier animals. 1 Biogeny is the general science ot the development of lite ; ontogeny is the genesis of the individual (or the science dealing with this — embryology); and phytogeny the genesis of the species. Further explanation will be given presently. — Trans. PREFACE TO THE FOURTH EDITIOX -. On the other hand, the cenogenetic phenomena (such as, for instance, the embryonic formation of the foetal membranes, the allantois, the dual structure of the heart, etc.) have only a subordinate and indirect interest for phytogeny, as they have arisen later by the adaptation of the foetus to its embryonic conditions. S. The many gaps in phytogeny, which are due to the lack of empirical material in embryology, may be remedied for the most part from paleontology and comparative anatomy. The application of these general principles of biogeny to the particular case of the evolution of man, as I first attempted it in my Anthropogenie, was bound, oi course — being the earliest independent advance into a fresh field of investigation— to be imperfect. At the most it could only hope to attract attention to this new inquiry, and to induce other Students to test the results in their special provinces. When we compare the condition of our science at that time with its situation to-day, I think we must admit that my Anthropogenie fully achieved its aim in this respect. Most men of science who have since worked in the field of comparative evolution are convinced to-dav that the two chief sections of it which I was the first to distinguish — Ontogeny and Phytogeny — have a causal connection of the closest character, and that the one cannot be understood apart from the other. The great majority of the useful results which their sedulous and searching inquiries have yielded can only be thoroughly appreciated when we recognise that the facts of ontogeny have found an explanation in phytogeny. Twenty-five vears ago, when my Generelle Morphologic appeared, human embryology was generally looked upon as a sort of fairyland, in which a number of most extraordinary and enigmatic processes were linked together without any visible ground in the shape of causal connection. To-day, on the contrary, we see in this chain of wonderful processes an historical document of the first importance, a chapter of the story of creation, which gives us most valuable information as to the chief features of the bodily structure and mode of life of our animal ancestors. The brilliant progress that comparative embryology has made during the last few decades is often attributed to extrinsic considerations — to the great number of fresh workers in this field of research, and to the improvement in the technical methods of investigation and the instruments used in the study. Certainly we must not fail to appreciate these advantages, especially the improvement of the microscope and microtome ; but the chief cause of progress has been the application of phylogenetic methods. It is to this we owe that immense enlargement of our intellectual horizon which enables us to regard the whole story of organic life, from the earliest beginning to the present day, as a vast mechanical process. It is reserved for phylogeny " to reduce the constructive forces of the animal body to the general forces or life-tendencies of the universe." No sooner does the science of the evolution of species shed its light on the dark puzzles of embryology than the true laws of development take definite shape. It is becoming clearer every year that this alone is the right path; that the facts of ontogeny can only be really explained by the theories of phylogeny. Moreover, the number and importance of the facts which we borrow from two other fields of research, the cognate sciences of paleontology and comparative anatomy, also grow every year. The profound and intimate connection of the historical documents furnished by these two sciences with those of ontogeny is growing clearer and more impressive the more we penetrate to these three sources of history. The need for using the three classes of documents in equal measure and with discrimination in the tracing of our ancestral tree is more evident every day. These leading principles, which I had presented and followed in the first edition of the Anthropogenie, have been applied far more thoroughly and comprehensively in the fourth edition, as our biological knowledge has been great* enlarged in all three fields of inquiry during the last fifteen years. In thus recognising and appreciating these general biogenetic principles, I find myself completely opposed to the purely descriptive and so-called "exact" method of embrvological study, which takes the careful description o( the facts of the science to be its sole proper purpose. When this "descriptive embryology" rises, in spite of its restriction, to an explanation of the facts it describes, it assumes the proud title of "physiological embryology." It fancies it has found the real mechanical causes of the facts of embryology when it has traced them to simple physical processes, such as the bending and folding of elastic plates, the hollowing of vesicles, and so forth. The chief defect of this "exact" or physiological — it would be better to say, " pseudo-mechanical " — method in embryology is seen in its attempt to reduce most complex historical processes to simple physical phenomena. When, for instance, the spinal cord of the vertebrate embryo severs itself from the general envelope, or when the five cerebral vesicles are formed by transverse folds at its bulbous upper extremity, it might seem to a superficial observer that these are simple physical processes. But we do not really understand them until we trace them to their true phylogenetic causes, and see that each of these apparently simple processes is the recapitulation of a long series of historical changes (modified by being inherited in a concentrated form), for the production of which in the race-history of our animal ancestors a vast number of instances of adaptation and heredity have co-operated during millions of years. Naturally, each of these physiological processes has in turn been determined by mechanical causes, or by physical and chemical conditions ; but these are far removed from direct and exact observation, as they are " pre-historic " phenomena of the remote past. I have alreadv, in my essays on Aims and Methods <>/ the Modern Science of Evolution (1875) and The Origin and Development of Animal Tissues (1884), pointed out the chief errors of this pretentious " mechanical science of embryology," and shown its radical opposition to our phylogenetic method. Surprise has often been expressed that so superficial a method, directed solely to the external appearance of the embryonic processes, and ignoring their historic nature, should have attained such considerable results. It is due mainly to the restriction of its aim. This narrowness of the pseudomechanical school is, in fact, three-fold. Firstly, it restricts itself in the use of its empirical material, as it only uses one of the three great documents — ontogeny — and ignores the other two — paleontology and comparative anatomy. Secondly, it restricts itself in its scientific method, in assuming as its sole aim the exact determination, with rule and compasses, of the embryonic forms. And, thirdly, it restricts itself in its philosophic insight, since it excludes all comparison with cognate phenomena and all correlation of the parts with the whole. However, this concentration — in itself a most prolific source of error — is welcomed in many quarters to-day, at a time when the narrowest specialism obtains its greatest triumphs, when the study of history is reversed, and when every thoughtful scientist who looks to the connection of phenomena is tabooed as "a natural philosopher." For all that, the scienc'e of evolution is an historical, and not an " exact," inquiry. Convinced that this method of anthropogenetic research is the method of the future, I conclude with the hope that this enlarged fourth edition of the Anthropogenic may, like its predecessors, contribute towards the enkindling of a deeper interest in the most important basis of anthropology. " Know thyself": that is the source of all wisdom. But it is impossible for a man to have real self-knowledge unless he is acquainted with the story of his development. Nearly thirty years have elapsed since the appearance of the first edition of the Anthrqpogente, and twelve years since the publication of the fourth edition. In the long interval scientific research into the subject of the work lias made extraordinary progress, not only in the great enlargement of the field of inquiry and the multiplication of workers, but also by the improvement of methods and greater thoroughness in the treatment of the most important questions. Hence I found it no light task to undertake a new issue of my work after such a lapse of time, and in advanced age. But, after long hesitation, I was moved to do so by the following considerations. My Anthropogenic was in a twofold sense a " first attempt " when it appeared in 1874. In the first place, I approached the difficult and hitherto neglected task of applying to man the chief law of biogeny in all its force, and of giving a hypothetical sketch of the course of his ancestral development founded on the observed facts of embryology. But I also made the still more difficult attempt to render these complicated embryological facts, and the cognate theories of phytogeny, intelligible, not merely to the small circle of my scientific colleagues, but also, by a popular presentation, to the general public. In both respects my work lias remained for thirty years the only one of its kind ; and on this account I deemed it my duty, in spite of its great defects, of which I am not unconscious, to undertake a revision of the book. Many disapproved of the presentation of so difficult and delicate a subject to the general reader. A number of my colleagues expressed the opinion that it was impossible and undesirable to give a popular treatment of so obscure and unfamiliar a study as human embryology ; and that it was still more regrettable to associate with these facts of embryology the airy and precarious hypotheses of phylogeny. This academic view, which is widely shared in learned circles, was extended to the popularisation of the whole science of evolution and the monistic conception "of life which is founded thereon. I have never been able to accept this opinion of the German professors ; I share, on the contrary, the view of the learned among our neighbours, that the whole educated world has a right to be acquainted with the most important advances of science, even when their general results are only matters of theory and are opposed to the prevailing beliefs. It is enough to quote the instance of geology. With this conviction I undertook, in my History of Creation, in 1868, the difficult task of introducing the modern science of evolution, founded bv Darwin, to the general reader, and to win for phylogeny the general recognition which its sister-science, geology, had long enjoyed. The immense correspondence I have had in connection with the ten editions of this book has proved to me that it met a real want on the part of the public. The same may be said of my work, The Riddle of the Universe, in which I gathered together the conclusions of fifty years of study in 1899. I attribute the remarkable success of this " popular study of the monistic philosophy " to no special merit of my book, but to the eagerness of the majority of educated people to acquaint themselves with the results of progressive science and cast off the superstitions of conventional theology and metaphysics. Interest in the embryology of plants and animals — that is, in the experimental study of these mysterious processes — has increased during the last ten years to an extent that was undreamt-of fifty years ago. Every year a number of specialist publications are issued which deal with one or other subject in this very attractive and most fruitful field of research. An introduction to this wonderful study, once so remote and exclusive, is provided by well-illustrated manuals and text-books. Unfortunately, many of these works show a lack of general morphological (or anatomical) knowledge, and of the indispensable method of comparison with related phenomena — not only of " comparative embryology," but also "comparative anatomy "; that is to say, of a discerning- and philosophical study of the complicated conditions of the whole series of tonus, or the stem, to which the organism in question belongs. It is also necessary to have a thorough preparatory training in classification, or an acquaintance with the relations of affinity, on the ground of which our "natural system " arranges the classes, orders, families, and so on. I have shown in my Systematische Phylogenie* (1894-6 — three volumes) how profound an insight this " phyletic classification " gives us into the history of the stem. Paleontology is even more neglected than comparative anatomy and classification by most of our modern embrvologists. Many of them are totally ignorant of it. Nevertheless, the fossils, the historical succession and systematic arrangement of which are taught in paleontology, are just as important documents for the history ot the stem as the embryos which are taken by these one-sided embryologists to be the only fitting subject of research. We must, it is true, grant that most of the paleontologists are equally narrow ; they commonly lack the necessary preliminary training in comparative anatomv and embryology which is indispensable for the correct appreciation of the fossilised remains and their phvlogenetic significance. It was my chief and constant care, in the heavy task of preparing this fifth edition of my Anthropogenic, to avoid this narrowness, and to use all three documents bearing on our ancestral history in even greater force and harmony than in the preceding editions. Paleontology, comparative anatomy, and ontogeny must complete each other's work, and give to the historical hypotheses of ph\ logeny that firmness and fullness which they are bound to secure. In order to make this work accessible to a wider class of readers, I have considerably increased the number of illustrations in the present edition. The number of plates (originally twelve) is now thirty, and the illustrations in the text have been increased from 210 to 512 ; the number of genealogical tables is raised from thirty-six to sixty. The text has also been much extended ; the forty-six sheets of the first edition, and fifty-seven of the fourth, have now grown to sixty-two. I have, nevertheless, left unchanged the general arrangement of the thirty chapters. I must express my gratitude to the house of Wilhelm Engelmann for the excellent production of the work and assistance in preparing its many illustrations ; and to my pupil, Heinrich Schmidt, for his aid in correcting proofs and revision of the index. To speak of the alterations in detail, most of the chapters have been substantially improved, and some of them have been entirely re-written. I thought it necessary to include at least the most important advances that have been made in each branch from the vast and increasing literature of the subject. I fear that many errors may have been overlooked. That was inevitable in view of the intricacy of the work and the defects of the craftsman. Yet I hope the book will attain its chief purpose of introducing the thoughtful reader into the great and wonderful realm of the evolution of man, and stimulate him to reflect on its significance. I would include especially teachers, doctors, and students, among these "thoughtful readers"; but I appeal also to the many educated men and women who desire to know the full truth as to the origin and development of their individual being and the place of man in nature. EVOLUTION1 General importance of the science of human evolution. Ignorance of it among educated people Tin- two sections of the science of evolution : Ontogeny or embryology, and Phytogeny or stem-history. Causal connection between the two sections. Phytogeny is the cause of ontogeny. Ontogeny as a summary or recapitulation of Phytogeny. Incompleteness of this summary. The chief law of biogeny. Heredity and adaptation are the two constructive functions, or the mechanical causes, of evolution. Exclusion of final causes. Sole validity of mechanical causes. Supplanting of the dualistic by the monistic philosophy. Great importance of tin' facts of embryology for the monistic philosophy. Palingenesis and cenogenesis. Evolution of structure and function. Necessary connection ofphysiogeny and morphogeny. Evolutionary science hitherto an achievement of morphology, not physiology. The field of natural phenomena into which I would introduce my readers in the following chapters has a quite peculiar place in the broad realm of scientific inquiry. There is no object of investigation that touches man more closely, and the knowledge of which should be more acceptable to him, than his own frame. But among all the various branches of the natural history of mankind, or anthropology, the story of his development bv natural means must excite the most lively interest. It gives us the key of the great worldriddles at which the human mind has been working for thousands of years. The problem of the nature of man, or the question of man's place in nature, and the cognate inquiries as to the past, the earliest history, the present situation, and the future of humanity — all these most important questions are directly and intimately connected with that branch of study which we call the science of the ' The English works recommended by Professor llaeekel are : Chap. xiii. of Darwin's Origin of Species, Spencer's Principles »/' Biology, and Haeckel's Riddle of the Universe. — Trans. THE FUXDAMEXTAI. LA W OF ORGAXIC EVOLUTIOX evolution of man, or, in one word, " Anthropogeny " (the genesis of man). Yet it is an astonishing but incontestable fact that the science of the evolution of man does not even yet form part of the scheme of general education. In fact, educated people even in our day are for the most part quite ignorant of the important truths and remarkable phenomena which anthropogeny teaches us. As an illustration of this curious state of things, it may be pointed out that most of what are considered to be " educated" people do not know that every human being is developed from an egg, or ovum, and that this egg is one simple cell, like any other plant or animal egg. They are equally ignorant that in the course of the development of this tiny, round egg-cell there is first formed a body that is totally different from the human frame, and has not the remotest resemblance to it. Most of them have never seen such a human foetus or embryo in the earlier period of its development, and do not know that it is quite indistinguishable from other animal embryos. At first the embryo is no more than a globular group of cells, then it becomes a simple hollow sphere, the wall of which is composed of a layer of cells. Later it approaches very closely, at one period, to the anatomic structure of the lancelot, afterwards to that of a fish, and again to the typical build of the amphibia and mammals. As it continues to develop a form appears which is like those we find at the lowest stage of mammal-life (such as the duckbills), then a form that resembles the marsupials, and only at a late stage a form that has a resemblance to the ape; until at last the definite human form emerges and closes the series of transformations. These suggestive facts are, as I said, still almost unknown to the general public — so completely unknown that, if one casually mentions them, they are called into doubt or denied outright as fairy-tales. Everybody knows that the butterfly emerges from the pupa, and the pupa from a quite different thing called a larva, and the larva from the butterfly's egg. But few besides medical men are aware that man, in the course of his individual formation, passes through a series of transformations which are not less the butterfly. The mere description of these remarkable changes through which man passes during his embryonic life should arouse considerable interest. But the mind will experience a far keener satisfaction when we trace these curious facts to their causes, and when we learn to behold in them natural phenomena which are of the highest importance throughout the whole field of human knowledge. The}' throw light first of all on the " natural history of creation," then on psychology, or •• the science of the soul," and through this on the whole of philosophy. And as the general results of every branch of inquiry are summed up in philosophy, all the sciences come in turn to be touched and influenced more or less by the study of the evolution of man. But when I say that I propose to present here the most important features of these phenomena and trace them to their causes, I take the term, and I interpret my task, in a very much wider sense than is usual. The lectures which have been delivered on this subject in the universities during the last half-century are almost exclusively adapted to medical men. Certainly, the medical man has the greatest interest in Studying the origin of the human body, with which he is daily occupied. But I must not give here this special description of the embryonic processes such as it has hitherto been given, as most of my readers have not studied anatomy, and are not likely to be entrusted with the care of the adult organism. 1 must content myself with giving some parts of the subject only in general outline, and must not enter upon all the marvellous, but very intricate and not easily described, details that are found in the story of the development of the human frame. To understand these fully a knowledge of anatomy is needed. I will endeavour to be as plain as possible in dealing with this branch of science. Indeed, a sufficient general idea of the course of the embryonic development of man can be obtained without going too closely into the anatomic details. I trust we may be able to arouse the same interest in this delicate field oi inquiry as has been meet more obstacles here than elsewhere. The story of the evolution of man, as it has hitherto been expounded to medical students, has usually been confined to embryology — or, more correctly, ontogeny — or the science of the development of the individual human organism. But this is really only the first part of our task, the first half of the story of the evolution of man in that wider sense in which we understand it here. We must add as the second half — as another and not less important and interesting branch of the science of the evolution of the human stem — phylogeny : this may be described as the science of the evolution of the various animal forms from which the human organism has been developed in the course of countless ages. Everybody now knows of the great scientific activity that was occasioned by the publication of Darwin's Origin of Species in 1859. The chief direct consequence of this publication was to provoke a fresh inquiry into the origin of the human race, and this has proved beyond question our gradual evolution from the lower species. We give the name of " Phylogeny " to the science which describes this ascent of man from the lower ranks of the animal world. The chief source that it draws upon for facts is "Ontogeny," or embryology, the science of the development of the individual organism. Moreover, it derives a good deal of support from paleontology, or the science of fossil remains, and even more from comparative anatomy, or morphology. These two branches of our science — on the one side ontogeny or embryology, and on the other phylogeny, or the science of race-evolution — are most vitally connected. The one cannot be understood without the other. It is only when the two branches fully co-operate and supplement each other that " Biogeny " (or the science of the genesis of life in the widest sense) attains to the rank of a philosophic science. The connection between them is not external and superficial, but profound, intrinsic, and causal. This is a discovery made by recent research, and it is most clearly and correctly expressed in the comprehensive law which I have called "the fundamental law o( organic evolution," or " the fundamental law of biogenv." This general law, to which we shall find ourselves constantly recurring, and on the recognition of which depends one's whole insight into the story of evolution, may be briefly expressed in the phrase: "The history of the fcetus is a recapitulation of the history of the race"; or, in other words, "Ontogeny is a recapitulation o( phylogeny." It may be more fully stated as follows: The series of forms through which the individual organism passes during its development from the ovum to the complete bodily structure is a brief, condensed repetition of the long scries of forms which the animal ancestors of the said organism, or the ancestral forms of the species, have passed through from the earliest period of organic life down to the present day. The causal character of the relation which connects embrvology with stem-history is due to the action of heredity and adaptation. When we have rightly understood these, and recognised their great importance in the formation of organisms, we can go a step further and say: Phylogenesis is the mechanical cause of ontogenesis.1 In other words, the development of the stem, or race, is the cause, in accordance with the phvsiological laws of heredity and adaptation, of all the changes which appear in a condensed form in the evolution of the fcetus. The chain of manifold animal forms which represent the ancestrv of each higher organism, or even of man, according to the theory of descent, always form a connected whole. We may designate this uninterrupted series of forms with the letters of the alphabet: A, B, C, D, E, etc., to Z. In apparent contradiction to what I have said, the story ot the development of the individual, or the ontogeny of most organisms, only offers to the observer a part of these forms; 1 The term "genesis," which recurs throughout, means, of course, "birth " or "origin.'1 From this we get: Biogeny=the origin of life (.bios) \ Anthropogenj : the origin of taan(anthropos) ; Ontogeny the origin of the individual ( on j; Phylogeny = the origin of the species (phulon ) -, and so on. In each case the 1. -rin may refer to tin- process itself, or to the science describing the process. — Trans. so that the defective series of embryonic forms would run: A, B, D, F, H, K, M, etc.; or, in other cases, B, D, H, L, M, N, etc. Here, then, as a rule, several of the evolutionaryforms of the original series have fallen out. Moreover, we often find — to continue with our illustration from the alphabet — one or other of the original letters of the ancestral series represented by corresponding letters from a different alphabet. Thus, instead of the Roman B and D, we often have the Greek B and A. In this case the text of the biogenetic law has been corrupted, just as it had been abbreviated in the preceding case. But, in spite of all this, the series of ancestral forms remains the same, and we are in a position to discover its original complexion. In reality, there is always a certain parallel between the two evolutionary series. But it is obscured from the fact that in the embryonic succession much is wanting that certainly existed in the earlier ancestral succession. If the parallel of the two series were complete, and if this great fundamental law affirming the causal nexus between ontogeny and phylogeny in the proper sense of the word were directly demonstrable, we should only have to determine, by means of the microscope and the dissecting knife, the series of forms through which the fertilised ovum passes in its development; we should then have before us a complete picture of the remarkable series of forms which our animal ancestors have successively assumed from the dawn of organic life down to the appearance of man. But such a repetition of the ancestral history by the individual in its embryonic life is very rarely complete. We do not often find our full alphabet. In most cases the correspondence is very imperfect, being greatly distorted and falsified by causes which we will consider later. We are thus, for the most part, unable to determine in detail, from the study of its embryology, all the different shapes which an organism's ancestors have presented ; we usually — and especially in the case of the human foetus — encounter many gaps. It is true that we can fill up most of these gaps satisfactorily with the help of comparative anatomy, but we cannot do so from direct embryological observation. Hence it is important that we find a large number of lower animal forms to be still represented in the course of man's embryonic development. In these cases we may draw our conclusions with the utmost security as to the nature of the ancestral form from the features of the form which the embryo momentarily assumes. To give a few examples, we can infer from the fact that the human ovum is a simple cell that the first ancestor of our species was a tiny unicellular being, something like the amoeba. In the same way, we know, from the fact that the human foetus consists, at the first, of two simple cell-layers (the gastrula J, that the gas trcea, a form with two such layers, was certainly in the line of our ancestry. A later human embryonic form (the chordula) points just as clearly to a worm-like ancestor (the prochordouici J, the nearest living relation of which is found among the actual ascidia. To this succeeds a most important embrvonic stage ( ' acnuiia J, in which our headless fcetus presents, in the main, the structure of the amphioxus. But we can only indirectly and approximatelv, with the aid of comparative anatomy and ontogeny, conjecture what lower forms enter into the chain of our ancestry between the gastrasa and the chordula, and between this and the amphioxus. In the course of the historical development (by means of heredity in a condensed form) many intermediate structures have gradually fallen out, which must certainly have been represented in our ancestry. But, in spite of these many, and sometimes very appreciable, gaps, there is no contradiction between the two successions. In fact, it is the chief purpose of this work to prove the real harmony and the original parallelism of the two. I hope to show, on a substantial basis of facts, that we can draw most important conclusions as to our genealogical tree from the actual and easily-demonstrable series of embryonic changes. We shall then be in a position to form a general idea of the wealth of animal forms which have figured in the direct line of our ancestry in the lengthy history of organic life. sharply and clearly between the primitive, palingenetic (or ancestral) evolutionary processes and those due to cenogenesis. ' By palingenetic processes, or embryonic recapitulations, we understand all those phenomena in the development of the individual which are transmitted from one generation to another by heredity, and which, on that account, allow us to draw direct inferences as to corresponding structures in the development of the species. On the other hand, we give the name of cenogenetic processes, or embryonic variations, to all those phenomena in the foetal development that cannot be traced to inheritance from earlier species, but are due to the adaptation of the foetus, or the infant-form, to certain conditions of its embryonic development. These cenogenetic phenomena are foreign or later additions ; they allow us to draw no direct inference whatever as to corresponding processes in our ancestral history, but rather hinder us from doing so. This careful discrimination between the primary or palingenetic processes and the secondary or cenogenetic is of great importance for the purposes of the scientific history of a species, which has to draw conclusions from the available facts of embryology, comparative anatomy, and paleontology, as to the processes in the formation of the species in the remote past. It is of the same importance to the student of evolution as the careful distinction between genuine and spurious texts in the works of an ancient writer, or the purging of the real text from interpolations and alterations, is for the student of philology. It is true that this distinction has not yet been fully appreciated by many scientists. For my part, I regard it as the first condition for forming any just idea of the evolutionary process, and I believe that we must, in accordance with it, divide embryology into two sections — palingenesis, or the science of repetitive forms ; and cenogenesis, or the science of supervening structures. ' Palingenesis = new birth, or re-incarnation (palin = again, genesis or genea = development) ; hence its application to the phenomena which are recapitulated by heredity from earlier ancestral forms. Cenogenesis = foreign or negligible development (kenos and genea) ; hence, those phenomena which come later in the story of life to disturb the inherited structure, by a fresh adaptation to environment. — Trans. To give at once a few examples from the science of man's origin in illustration of this important distinction, I may instance the following processes in the embryology oi man, and of all the higher vertebrates, as palingenetic : the formation of the two primary germinal layers and of the primitive gut, the undivided structure of the dorsal nervetube, the appearance of a simple axial rod between the medullary tube and the gut, the temporary formation of the gill-clefts and arches, the primitive kidneys, and so on. All these, and many other important structures, have clearly been transmitted by a steady heredity from the early ancestors of the mammal, and are, therefore, direct indications of the presence of similar structures in the history of the stem. On the other hand, this is certainly not the case with the following embryonic changes, which we must describe as cenogenetic processes : the formation of the yelk-sac, the allantois, the placenta, the amnion, the serolemma, and the chorion — or, generally speaking, the various foetal membranes and the corresponding changes in the blood vessels. Further instances are : the dual structure of the heart cavity, the temporary division of the plates of the primitive vertebra? and lateral plates, the secondary closing of the ventral and intestinal walls, the formation of the navel, and so on. All these and many other phenomena are certainly not traceable to similar structures in any earlier and completely-developed ancestral form, but have arisen simply by adaptation to the peculiar conditions of embryonic life (within the fcetal membranes). In view of these facts, we may now give the following more precise expression to our chief law of hiogeny : — The evolution of the foetus (or ontogenesis) is a condensed and abbreviated recapitulation of the evolution of the stem (or phylogenesis) ; and this recapitulation is the more complete in proportion as the original development (or palingenesis) is preserved by a constant heredity ; on the other hand, it becomes less complete in proportion as a varying adaptation to new conditions increases the disturbing factors in the development (or catagenesis). The cenogenetic alterations or distortions of the original palingenetic course of development take the form, as a rule, of a gradual displacement of the phenomena, which is slowly effected by adaptation to the changed conditions of embryonic existence during the course of thousands of years. This displacement may take place as regards either the locality or the time of a phenomenon. The first is called heterotopism, the second heterochronism. Heterotopisms, or variations in locality, affect, in the first place, the cells, or elementary parts of which the organs are composed ; but they also affect the organs themselves. Thus, for instance, the sexual glands in the human embryo, and most of the higher animals, arise out of the middle germinal layer. On the other hand, the comparative embryology of the lower animals shows us that originally they did not arise from this, but from one of the primary germinal layers. However, the germ-cells have gradually changed their position, and passed over at so early a period from their original situation into the middle layer that they now seem really to arise from it. A similar heterotopism is observed in the case of the primitive renal (kidney) passages of the higher vertebrates, which originally took their rise in the external skin. Even in the case of the origin of the mesoderm (middle-skin) itself heterotopism, in connection with a removal of embryonic cells from one skin layer to another, plays an important part. Heterochronism, or variation in time, is not less instructive. It consists in the fact that the series of forms in which the organs successively appear is different in embryology from what the stem history leads us to expect. Just as the spatial disposition is falsified in heterotopism, so we find the time arrangement altered in heterochronism. This may appear either as an acceleration or a delay in the rise of an organ. As cases of ontogenetic acceleration we may instance, in the embryonic development of man, the early appearance of the heart, the gill-clefts, the brain, the eyes, etc. These organs clearly arise much earlier, in comparison with others, than was originally the case with our ancestors. clear instances of ontogenetic retardation. The great importance and strict regularity of these time variations in embryology have been carefully studied recently by Ernest Mehnert, in his Biomcchanik (Jena, 1898). He formulates his "chief law of organogenesis" in the following words : " The rapiditv of the embryonic development of an organ is in proportion to its stage of evolution, which has been retarded for a time. It rises with the increase and falls with the diminution of the stage of evolution once attained." Mehnert contends that our biogenetic law has not been impaired by the attacks of its opponents, and goes on to say : " Scarcelv any piece of knowledge has contributed so much to the advance of embryology as this ; its formulation is one of the most signal services to general biology. It was not until this law passed into the flesh and blood of investigators, and they had accustomed themselves to see a reminiscence of ancestral history in embryonic structures, that we witnessed the great progress which embryological research has made in the last two decades." The best proof of the correctness of this opinion is that now the most fruitful work is done in all branches of embryology with the aid of this biogenetic law, and that it enables students to attain every year thousands of brilliant results that they would never have reached without it. It is only when one appreciates the cenogenetic processes in relation to the palingenetic, and when one takes careful account of the changes which the latter may suffer from the former, that the radical importance of the biogenetic law is recognised, and it is felt to be the most illuminating principle in the science of evolution. In this task of discrimination it is the silver thread in relation to which we can arrange all the phenomena of this realm of marvels — the "Ariadne thread," which alone enables us to find our way through this labyrinth of forms. Hence the brothers Sarasin, the zoologists, could say with perfect justice, in their study of the evolution of the Ichthyopliis, that " the great biogenetic law is Even at an earlier period, when a correct acquaintance with the evolution of the human and animal frame was only just being obtained — and that is scarcely eighty years ago! — the greatest astonishment was felt at the remarkable similarity observed between the embryonic forms, or stages of foetal development, in very different animals ; attention was called even then to their close resemblance to certain fully-developed animal forms belonging to some of the lower groups. The older scientists (Oken, Treviranus, and others) knew perfectly well that these lower forms in a sense illustrated and fixed, in the hierarchy of the animal world, a temporary stage in the evolution of higher forms. The famous anatomist Meckel spoke in 1821 of a "similarity between the development of the embryo and the series of animals." Baer raised the question in 1828 how far, within the vertebrate type, the embryonic forms of the higher animals assume the permanent shapes of members of lower groups. But it was impossible fully to understand and appreciate this remarkable resemblance at that time. We owe our capacity to do this to the theory of descent; it is this that puts in their true light the action of heredity on the one hand and adaptation on the other. It explains to us the vital importance of their constant reciprocal action in the production of organic forms. Darwin was the first to teach us the great part that was played in this by the ceaseless struggle for existence between living things, and to show how, under the influence of this (by natural selection), new species were produced and maintained solely by the interaction of heredity and adaptation. It was thus Darwinism that first opened our eyes to a true comprehension of the supremely important relations between the two parts of the science of organic evolution — Ontogeny and Phylogeny. Heredity and adaptation are, in fact, the two constructive physiological functions of living things : unless we understand these properly we can make no headway in the study of evolution. Hence, until the time of Darwin no one had a clear idea of the real nature and causes of embryonic development. It was impossible to explain the curious series of forms through which the human embryo passed ; it was quite unintelligible why this strange succession of animal-like forms appeared in the series at all. It had previously been generally assumed that the man was found complete in all his parts in the ovum, and that the development consisted only in an unfolding of the various parts, a simple process of growth. This is by no means the case. On the contrary, the whole process of the development of the individual presents to the observer a connected succession of various animal-forms ; and these forms display a great variety of external and internal structure. But why each individual human being should pass through this series of forms in the course of his embryonic development it was quite impossible to say until Lamarck and Darwin established the theory of descent. Through this theory we have at last detected the real causes, the causce efficientes, of the individual development; we have learned that these mechanical causes suffice of themselves to effect the formation of the organism, and that there is no need of the final causes which were formerly assumed. It is true that in the academic philosophies of our time these final causes still figure very prominently; in the new philosophy of nature we can entirely replace them by efficient causes. Before I pass from the subject I must speak further of this, one of the most brilliant achievements of the human mind in modern times. The history of philosophy shows us that final causes are still generally regarded in philosophic circles, just as among the philosophers of antiquity, as the real sources of the phenomena of organic life, and especially o\ human life. This dominant teleology, which is largely based on Kant, assumes that the processes of organic life, especially those of development, can only be explained by final causes, and are not susceptible of a mechanical — that is to say, a really scientific — explanation. But the darkest enigmas which had hitherto beset us in this connection, and which seemed to be only approachable through teleology, have been fully solved in a mechanical sense by the theory of descent. The reconstruction of the science of human evolution which this brought about removed the greatest impediments from the path of research. We shall see, in the course of our inquiry, how the most wonderful and hitherto insoluble enigmas in the human and animal frame have proved amenable to a mechanical explanation, by causes acting without prevision, through Darwin's reform of the science of evolution. We have everywhere been able to substitute unconscious causes, acting from necessity, for conscious, purposive causes.1 If the new science of evolution had done no more than this, every thoughtful man would have to admit that it had accomplished an immense advance in knowledge. It means that in the whole of philosophy that tendency which we call monistic, in opposition to the dualistic, which has hitherto prevailed, must be accepted.2 At this point the science of human evolution has a direct and profound bearing on the foundations of philosophy. I have dealt with this relation very fully in my Riddle of the Universe. In the first part I show how modern anthropology has, by its astounding discoveries during the second half of the nineteenth century, compelled us to take a completely monistic view of life. Our bodily structure and its life, our embryonic development and our evolution as a species, teach us that the same laws of nature rule in the life of man as in the rest of the universe. For this reason, if for no others, it is desirable, nay, indispensable, that every man who wishes to form a serious and philosophic view of life, and, above all, the expert philosopher, should acquaint himself with the chief facts of this branch of science. 1 The monistic or mechanical philosophy of nature holds that only unconscious, necessary, efficient causes are at work in the whole field of nature, in organic life as well as in inorganic changes. On the other hand, the dualist or vitalist philosophy of nature affirms that unconscious forces arc only at work in the inorganic world, and that we find conscious, purposive, or final causes in organic nature. 2 Monism is neither purely materialistic nor purely spiritualistic, but a reconciliation of these two principles, since it regards the whole of nature as one, and sees only efficient causes at work in it. Dualism, on the contrary, holds that nature and spirit, matter and force, the world and God, inorganic and organic nature, are separate and independent existences. Cf. The Riddle of the Universe, chap. xii. The facts of embryology have so great and obvious a significance in this connection that even in recent years dualist and teleological philosophers have tried to rid themselves of them by simply denying them. This was done, for instance, as regards the fact that man is developed from an egg, and that this egg or ovum is a simple cell, as in the case of other animals. When I had explained this pregnant fact and its significance in my Natural History of Creation, it was described in many of the theological journals as a dishonest invention of my own. The fact that the embryos of man and the dog are, at a certain stage of their development, almost indistinguishable, was also denied. When we examine the human embryo in the third or fourth week of its development, we find it to be quite different in shape and structure from the full-grown human being, but almost identical with that of the ape, the dog, the hare, and other mammals, at the same stage of ontogeny. We find a beanshaped body of very simple construction, with a tail below and a pair of fins at the sides, something like those of a fish, but very different from the limbs of man and the mammals. Nearly the whole front half of the body is taken up by a shapeless head without face, at the sides of which we find gill-clefts and arches as in the fish (see the thirteenth plate at the end of Chapter xiv.). At this stage of its development the human embryo does not differ in any essential detail from that of the ape, dog, horse, ox, etc., at a corresponding period. This important fact can easily be verified at any moment by a comparison of the embryos of man, the dog, hare, etc. Nevertheless, the theologians and dualist philosophers pronounced it to be a materialistic invention ; even scientists, to whom the facts should be known, have sought to denv them. There could not be a clearer proof of the profound importance of these embrvcilogical facts in favour of the monistic philosophy than is afforded by these efforts of its opponents to get rid of them by silence or denial. The truth is that these facts are most inconvenient for them, and are quite irreconcilable with their views. We must be all the more pressing on our side to put them in their proper light. I fully agree with Huxley when he says, in his Man's Place in Nature : " Though these facts are ignored by several wellknown popular leaders, they are easy to prove, and are accepted by all scientific men ; on the other hand, their importance is so great that those who have once mastered them will, in my opinion, find few other biological discoveries to astonish them." We shall make it our chief task to study the evolution of man's bodily frame and its various organs in their external form and internal structures. But I may observe at once that this is accompanied step by step with a study of the evolution of their functions. These two branches of inquiry are inseparably united in the whole of anthropology, just as in zoology (of which the former is only a section) or general biology. Everywhere the peculiar form of the organism and its structures, internal and external, is directly related to the special physiological functions which the organism or organ has to execute. This intimate connection of structure and function, or of the instrument and the work done by it, is seen in the science of evolution and all its parts. Hence the story of the evolution of structures, which is our immediate concern, is also the history of the development of functions; and this holds good of the human organism as of anv other. At the same time, I must admit that our knowledge of the evolution of functions is very far from being as complete as our acquaintance with the evolution of structures. One might say, in fact, that the whole science of evolution, or biogeny (both in ontogeny and phylogeny), has almost confined itself to the study of structures ; the biogeny of functions hardly exists even in name. That is the fault of the physiologists, who have as yet concerned themselves very little about evolution. It is only in recent times that physiologists like W. Engelmann, W. Preyer, M. Verworn, and a few others, have attacked the biogeny of functions. For a long time now the two great branches of biological research, morphology and physiology, have pursued separate ways. That is quite natural. The aims and methods of the two are very different. Morphology (anatomy), or the science of forms, seeks a scientific knowledge of organic structure, internal and external. On the other hand, physiology, or the science of functions, studies the vital phenomena. The two together make up biology. But the development of physiology during the last fifty years has been much more onesided than that of morphology. It has not only failed to make much use of the comparative method, which has given such great results in morphology, but it has also neglected evolutionarv principles. Hence in the last few decades morphology has far outrun physiology, though the latter is apt to put on superior airs in regard to its rival. Morphology has achieved its finest results in the way of comparative anatomy and ontogeny, and nearly all that I shall put before the reader in this work as to the evolution of man has been obtained by the labours, not of the physiologist, but of the morphologist. In fact, the one-sidedness of modern physiology is so great that it has hitherto neglected the study of the most important evolutionary functions, heredity and adaptation, and abandoned even these purely physiological subjects to the morphologist. We owe nearly all that we know about them to the morphologist, not to the physiologist. The latter concerns himself little more with the functions (or agencies) of evolution than with the evolution of functions. It will be the task of some future physiologist to engage in the study of the evolution of functions with the same zeal and success as has been done for the evolution of structures in morphogeny (the genesis of forms). Let me illustrate the close connection of the two by a couple of examples. The heart in the human embryo has at first a very simple construction, such as we find in permanent form among the ascidia and other low organisms; with this is associated a very simple system of circulation of the blood. Now, when we find that with the full-grown heart there comes a totally different and much more intricate circulation, our inquiry into the development of the heart becomes at once, not only a morphological, but also a physiological, study. Thus it is clear that the ontogeny of the heart can only be understood in the light of its phylogeny (or development in the past), both as regards function and structure. The same holds true of all the other organs and their functions. For instance, the science of the evolution of the alimentary canal, the lungs, or the sexual organs, gives us at the same time, through the exact comparative investigation of structure-development, most important information with regard to the evolution of the functions of these organs. This significant connection is very clearlv seen in the evolution of the nervous system. This system is in the economy of the human body the medium of sensation, will, and even thought, the highest of the psychic functions ; in a word, of all the various functions which constitute the proper object of psychology. Modern anatomy and physiology have proved that these psychic functions are immediately dependent on the fine structure and the composition of the central nervous system, or the internal texture of the brain and spinal cord. In these we find the elaborate cell-machinery, of which the psychic or soul-life is the physiological function. It is so intricate that most men still look upon the mind as something supernatural that cannot be explained on mechanical principles. But embryological research into the gradual appearance and the formation of this important system of organs yields the most astounding and significant results. The first sketch of a central nervous system in the human embryo presents the same very simple type as in the other vertebrates. A spinal tube is formed in the external skin of the back, and from this first comes a simple spinal cord without brain, such as we find to be the permanent psychic organ in the lowest type of mammal, the amphioxus. Not until a later stage is a brain formed at the anterior end of this cord, and then it is a brain of the most rudimentary kind, such as we find permanently among the lower fishes. This simple brain developes step by step, successively assuming forms which correspond to those of the amphibia, the reptiles, the duckbills, and the prosimias. Only in the last stage does it reach the highly organised form which distinguishes the development in man. Comparative physiology discovers a precisely similar growth. The function of the brain, the psychic activity, rises step bv step with the advancing development of its structure. Thus we are enabled, by this story of the evolution of the nervous system, to understand at length the natural development of the human mind and its gradual unfolding. It is onlv with the aid of embryology that we can grasp how these highest and mjst striking faculties of the animal organism have been historicallv evolved. In other words, a knowledge of the evolution of the spinal cord and brain in the human embryo leads us directly to a comprehension of the historic development (or phylogenv) of the human mind, that highest of all faculties, which we regard as something so marvellous and supernatural in the adult man. This is certainly one of the greatest and most pregnant results of evolutionary science. Happilv, our embrvological knowledge of man's central nervous svstem is now so adequate, and agrees so thoroughly with the complementary results of comparative anatomy and phvsiologv, that we are thus enabled to obtain a clear insight into one of the highest problems of philosophy, the phylogenv of the soul, or the ancestral history of the mind of man. Our chief support in this comes from the embryological study of it, or the ontogeny of the soul. This important section of psychology owes its origin especially to W. Prever, in his interesting works, The Mind of the Child (English translation) and Spezielle Physio/ogie des Embryo. The Biography of a Baby (1900), of Milicent Washburn Shinn, also deserves mention. \|See also Preyer's Mental Development in the Child (translation), and Sully's Studies of Childhood and Children's Ways. ] hope to reach the solution of this difficult problem. Thirty-six years have now elapsed since I established phylogeny as an independent science and showed its intimate causal connection with ontogeny in my (ienere/le Morphologie ; thirty years have passed since I gave in my gastraea-theory the proof of the justice of this, and completed it with the theory of germinal layers. When we look back on this period we may ask, What has been accomplished during it by the fundamental law of biogeny? If we are impartial, we must reply that it has proved its fertility in hundreds of sound results, and that by its aid we have acquired a vast fund of knowledge which we should never have obtained without it. There has been no dearth of attacks — often violent attacks — on my conception of an intimate causal connection between ontogenesis and phylogenesis ; but no other satisfactory explanation of these important phenomena has yet been offered to us. I say this especially with regard to Wilhelm His's theory of a "mechanical evolution," which questions the validity of phylogeny generally, and would explain the complicated embryonic processes without going beyond by simple physical changes — such as the bending and folding of leaves by electricity, the origin of cavities through unequal strain of the tissues, the formation of processes by uneven growth, and so on. But the fact is that these embryological phenomena themselves demand explanation in turn, and this can only be found, as a rule, in the corresponding changes in the long ancestral series, or in the physiological functions of hereditv and adaptation. Heinrich Schmidt (of Jena) has given a good account and criticism of the many attacks on the biogenetic law in his interesting pamphlet, Haeckel's biogenetisches Gmndgesetz und seine Gegner (Odenkirchen, 1902). He shows that not only distinguished zoologists, but botanists also, have recognised it, and made profitable use of it ; it holds good of the evolution of plants no less than of animals. On the other hand, none of its critics has offered anything better to replace it. Many of the criticisms, in fact, arise from pure misunderstanding, as is quite to be expected in so difficult and complicated a subject, or from a wrong idea of the relation of cenogenesis and palingenesis. But, in spite of all this, our knowledge of the mutual relations of these two series of phenomena grows every day, and our conviction increases that " Phylogenesis is the mechanical cause of ontogenesis." THE OLDER EMBRYOLOGY Aristotle's Generation of Animals. His acquaintance with the embryology of lower animals. Arrest of scientific research during the Middle Ages. The ris,- of embryology at the beginning of the seventeenth century. Fabricius ab Aquapendente. Harvey. Marcello Malpighi. The significance of the hatched egg. The theory of Pre-formation and Scatulation (Evolution and Pre-delineation). The unfolding of parts already formed. The theory of Scatulation for male and female. Either the spermatozoon or the egg is the pre-formed individual. Animaleulists or Spermatists (Leeuwenhock, Hartsoeker, Spallanzani). Ovulists (Haller, Leibnitz, Bonnet). A calculation of the germs stored in Eve's ovary. Discovery of parthenogenesis by Bonnet. Victory of the Pre-formation theory owing- to the authority of Haller and Leibnitz. Caspar Friedrieh Wolff. His life and works. The theoria generationis. New formation, or epigenesis. The evolution of the alimentary canal. First beginnings of the theory of germinal layers. The metamorphosis of plants. Germs of the cell theory. Wolff's monistic philosophy. It is in many ways useful, on entering upon the study of any science, to cast a glance at its historical development. The saying that "everything is best understood in its growth" has a distinct application to science. While we follow its gradual development we get a clearer insight into its aims and objects. Moreover, we shall see that the present condition of the science of human evolution, with all its characteristics, can only be rightly understood when we examine its historical growth. This task will, however, not detain us long. The study of man's evolution is one of the latest branches of natural science, whether you consider the embryological or the phylogenetic section of it. Apart from the few germs of our science which we find in classical antiquity, and which we shall notice presently, we may say that it takes its definite rise, as a science, in the yeat 1 759, when one of the greatest German scientists, Caspar Friedrieh Wolff, published his Theoria generationis. That was the foundation-stone of the science of animal embryology. It was not until fifty years later, in 1809, that Jean Lamarck published his Pliilosophie Zoologique — the first effort to provide a base for the theory of evolution ; and it was another half-century before Darwin's work appeared (in 1859), which we may regard as the first scientific attainment of this aim. But before we go further into this solid establishment of evolution, we must cast a brief glance at that famous philosopher and scientist of antiquity, who stood alone in this, as in many other branches of science, for more than 2,000 years : the " father of natural history," Aristotle. The extant scientific works of Aristotle deal with many different sides of biological research ; the most comprehensive of them is his famous History of Animals. But not less interesting is the smaller work, On the Generation of Animals {Peri zoon geneseos). This work treats especially of embryonic development, and it is of great interest as being the earliest of its kind and the only one that has come down to us in any completeness from classical antiquity. Like Aristotle's other scientific writings, this substantial little work has dominated the whole of science for 2,000 years. The philosopher was as keen in observation as he was profound in thought. Nevertheless, while his philosophic distinction has never been questioned, it is only in recent years that his worth as an observer has been properly appreciated. The men of science who turned to his scientific writings about the middle of the nineteenth century were astonished at the amount of information and the notable discoveries that they found. In connection with embryological questions, we must particularly note that Aristotle studied them in various classes of animals, and that among the lower groups he learned many most remarkable facts which we only re-discovered between 1830 and i860. It is certain, for instance, that he was acquainted with the very peculiar mode of propagation of the cuttle-fishes, or cephalopods, in which a yelk-sac hangs out of the mouth of the foetus. He knew, also, that embryos come from the eggs of the bee even when they have not been fertilised. This " parthenogenesis " (or virgin-birth) of the bees has only been established in our time by the distinguished zoologist of Munich, Siebold. He discovered that male bees come from the unfertilised, and female bees only from the fertilised, eggs. Aristotle further states that some kinds of fishes (of the genus serranus) are hermaphrodites, each individual having both male and female organs and being able to fertilise itself ; this, also, has been recently confirmed. He knew that the embryo of many fishes of the shark family is attached to the mother's body by a sort of placenta, or nutritive organ very rich in blood; apart from these, such an arrangement is only found among the higher mammals and man. This placenta of the shark was looked upon as legendary for a long time, until Johannes Miiller proved it to be a fact in 18^9. Thus a number of remarkable discoveries were found in Aristotle's embryological work, proving a very good acquaintance of the great scientist — possibly helped by his predecessors — with the facts of ontogeny, and a great advance upon succeeding generations in this respect. In the case of most of these discoveries he did not merely describe the fact, but added a number of observations on its significance. Some of these theoretical remarks are of particular interest, because they show a correct appreciation of the nature of the embryonic processes. He conceives the development of the individual as a new formation, in the course of which the various parts of the body take shape successively. When the human or animal frame is developed in the mother's body, or separately in an egg, the heart — which he regards as the starting-point and centre of the organism — must appear first. Once the heart is formed the other organs arise, the internal ones before the external, the upper (those above the diaphragm) before the lower (or those beneath the diaphragm). The brain is formed at an early stage, and the eyes grow out of it. These observations are quite correct. And, if we try to form some idea from these data of Aristotle's general conception of the embryonic process, we find a dim prevision of the theory which we now call epigenestSf and which Wolff showed 2,000 years afterwards to be the correct view. It is significant, for instance, that Aristotle denied the eternity of the individual in any respect. He said that the species or genus, the group of similar individuals, might be eternal, but the individual itself is temporary. It comes into being in the act of procreation, and passes away at death. During the 2,000 years after Aristotle no progress whatever was made in general zoology, or in embryology in particular. People were content to read, copy, translate, and comment on Aristotle. Scarcely a single independent effort at research was made in the whole of the period. During the Middle Ages the spread of strong religious beliefs put formidable obstacles in the way of independent scientific investigation. There was no question of resuming the advance of biology. Even when human anatomy began to stir itself once more in the sixteenth century, and independent research was resumed into the structure of the developed body, anatomists did not dare to extend their inquiries to the unformed body, the embryo, and its development. There were many reasons for the prevailing horror of such studies. It is natural enough, when we remember that a Bull of Boniface VIII. excommunicated every man who ventured to dissect a human corpse. If the dissection of a developed body were a crime to be thus punished, how much more dreadful must it have seemed to deal with the embryonic body still enclosed in the womb, which the Creator himself had decently veiled from the curiosity of the scientist ! The Christian Church, then putting many thousands to death for unbelief, had a shrewd presentiment of the menace that science contained against its authority. It was powerful enough to see that its rival did not grow too quickly. It was not until the Reformation broke the power of the Church, and a refreshing breath of the spirit dissolved the icy chains that bound science, that anatomy and embryology, and all the other branches of research, could begin to advance once more. However, embryology lagged far behind anatomy. The first works on embryology appear at the beginning of the sixteenth century. The Italian anatomist, Fabricius ab Aquapendente, a professor at Padua, opened the advance. In his two books [De formato foetu, 1600, and De format iane fee I us, 1604) he published the older illustrations and descriptions of the embryos of man and other mammals, and of the hen. Similar imperfect illustrations were given by Spigelius (De formato foetu, 1 631), and by Needham (1667) and his more famous compatriot, Harvey (1652), who discovered the circulation of the blood in the animal body and formulated the important principle, Omne vivum ex vivo (all life comes from pre-existing life). The Dutch scientist, Swammerdam, published in his Bible of Nature the earliest observations on the embryology of the frog and the division of its egg-yelk. But the most important embryological studies in the sixteenth century were those of the famous Italian, Marcello Malpighi, of Bologna, who led the way both in zoology and botany. His treatises, De formatione pulli and De ovo incubato (1687), contain the first consistent description of the development of the chick in the fertilised egg. Here I ought to say a word about the important part plaved by the chick in the growth of our science. The development of the chick, like that of the young of all other birds, agrees in all its main features with that of the other chief vertebrates, and even of man. The three highest classes of vertebrates — mammals, birds, and reptiles (lizards, serpents, tortoises, etc.) — have from the beginning of their embryonic development so striking a resemblance in all the chief points of structure, and especially in their first forms, that for a long time it is impossible to distinguish between them (see plates viii-xiii.). We have known now for some time that we need only examine the embryo of a bird, which is the easiest to get at, in order to learn the typical mode of development of a mammal (and therefore of man). As soon as scientists began to study the human embryo, or the mammal-embryo generally, in its earlier stages about the middle and end of the seventeenth century, this important fact was very quickly discovered. It is both theoretically and practically of great value. As regards the theory of evolution, we can draw the most weighty inferences from this similarity between the embryos of widely different classes of animals. But for the practical purposes of embryological research the discovery is invaluable, because we can fill up the gaps in our imperfect knowledge of the embryology of the mammals from the more thoroughly studied embryology of the bird. Hens' eggs are easily to be had in any quantity, and the development of the chick may be followed step by step in artificial incubation. The development of the mammal is much more difficult to follow, because here the embryo is not detached and enclosed in a large egg, but the tiny ovum remains in the womb until the growth is completed. Hence, it is very difficult to keep up sustained observation of the various stages in any great extent, quite apart from such extrinsic considerations as the cost, the technical difficulties, and many other obstacles which we encounter when we would make an extensive study of the fertilised mammal. The chicken has, therefore, always been the chief object of study in this connection. The excellent incubators we now have enable us to observe it in any quantity and at any stage of development, and so follow the whole course of its formation step by step. By the end of the seventeenth century Malpighi had advanced as far as it was possible to do with the imperfect microscope of his time in the embryological study of the chick. Further progress was arrested until the instrument and the technical methods should be improved. The vertebrate embryos are so small and delicate in their earlier stages that you cannot go very far into the study of them without a good microscope and other technical aid. But this substantial improvement of the microscope and the other apparatus did not take place until the beginning of the nineteenth century. Embryology made scarcely any advance in the first half of the eighteenth century, when the systematic natural history of plants and animals received so great an impulse through the publication of Linne's famous Systema Naturae. Not until 1759 did the genius arise who was to give it an entirely new character, Caspar Friedrich Wolff. Until then embryology had been occupied almost exclusively in unfortunate and misleading efforts to build up theories on the imperfect empirical material then available. The theory which then prevailed, and remained in favour throughout nearly the whole of the eighteenth century, was commonly called at that time "the evolution theory"; it is better to describe it as "the preformation theory."1 Its chief point is this : There is no new formation of structures in the embryonic development of any organism, animal or plant, or even of man ; there is only a growth, or unfolding, of parts which have been constructed and ready from all eternity, though on a very small scale and closely packed together. Hence, every living germ contains all the organs and parts of the bodv, in the form and arrangement they will present later, already within it, and thus the whole embryological process is merely an evolution in the literal sense of the word, or an unfolding, o{~ parts that were pre-formed and folded up in it. So, for instance, we find in the hen's egg not merely a simple cell, that divides and subdivides and forms germinal layers, and at last, after all kinds of variation and cleavage and reconstruction, brings forth the body of the chick ; but there is in every egg from the first a complete chicken, with all its parts made and neatly packed. These parts are so small or so transparent that the microscope cannot detect them. In the hatching, these parts merely grow larger, and spread out in the normal way. When this theory is consistently developed it becomes a "scatulation theory."- According to its teaching, there was made in the beginning one couple or one individual of each species of animal or plant ; but this one individual contained the germs of all the other individuals of the same species who should ever come to life. As the age of the earth was 'This theory is usually known as the "evolution theory" in Germany, in contradistinction to the "epigenesis theory." Hut as it is the latter that is called the "evolution theorj in England, France, and Italy, and "evolution" and "epigenesis" are taken to be synonymous, ii s,-c-ms better to call the first the " preformation theory." Kolliker has recently given the name of "evolutionism " to his •• theory of heterogeneous conception." generally believed at that time to be fixed by the Bible at 5,000 or 6,000 years, it seemed possible to calculate how many individuals of each species had lived in the period, and so had been packed inside the first being that was created. The theory was consistently extended to man, and it was affirmed that our common parent Eve had had stored in her ovary the germs of all the children of men. The theory at first took the form of a belief that it was the females who were thus encased in the first being. One couple of each species was created, but the female contained in her ovary all the future individuals of the species, of either sex. However, this had to be altered when the Dutch microscopist, Leeuwenhoek, discovered the male spermatozoa in 1690, and showed that an immense number of these extremely fine and mobile thread-like beings exist in the male sperm (this will be explained in the seventh chapter). This astonishing discovery was further advanced when it was proved that these living bodies, swimming about in the seminal fluid, were real animalcules, and, in fact, were the preformed germs of the future generation. When the male and female procreative elements came together at conception, these thread-like spermatozoa ("seed-animals") were supposed to penetrate into the fertile body of the ovum and begin to develop there, as the plant seed does in the fruitful earth. Hence, every spermatozoon was regarded as a homunculus, a tiny complete man ; all the parts were believed to be preformed in it, and merely grew larger when it reached its proper medium in the female ovum. This theory, also, was consistently developed in the sense that in each of these thread-like bodies the whole of its posterity was supposed to be present in the minutest form. Adam's sexual glands were thought to have contained the germs of the whole of humanity. This " theory of male scatulation " found itself at once in keen opposition to the prevailing " female " theory. All that was common to them was the erroneous idea that there are in every germ the germs of innumerable organisms to come enfolded in it — an idea that served as the ground of Linne's curious " prolepsis theory." The two rival theories at once opened a very lively campaign, and the physiologists of the eighteenth century were divided into two great camps — the Animalculists and the Ovulists — which fought vigorously. The struggle rather amuses us to-day when we know that both parties were wrong. As Kirchhoff says in his admirable biographical sketch of Wolff: "This controversy was as difficult to close as that on the question whether the angels live in the eastern or the western part of heaven." The animalculists held that the spermatozoa were the true germs, and appealed to the lively movements and the structure of these bodies. In the case of man and most of the other animals, these spermatozoa have a rather oval or pear-shaped head and a thickish stem, ending in an extremely fine and hair-like tail (Fig. 20). The whole structure is really only one cell — a ciliated cell. The head is the nucleus enclosed in a little of the cell-matter, and this is prolonged in the thick stem and fine, mobile tail; the latter is the " whip " (or cilium) by which it moves about, and corresponds to the cilium in a ciliated cell. But the animalculists believed that the " head " was a real head, and the rest of it a complete body. Leeuwenhoek, Hartsoeker, and Spallanzani were the chief champions of these fantastic speculations. The opposing party of the Ovulists, who clung to the older " evolution theory," affirmed that the ovum is the real germ, and that the spermatozoa merely stimulate it at conception to begin its growth; all the future generations are stored in the ovum. This view was held by the great majority of the biologists of the eighteenth century, in spite of the fact that Wolff proved it in 1759 to be without foundation. It owed its prestige chiefly to the circumstance that the most weighty authorities in the biology and philosophy of the day decided in favour of it, especially Haller, Bonnet, and Leibnitz. Albrecht Haller, professor at Gbttingen, who is often called the father of physiology, was a man of wide and varied learning, but he does not occupy a very high position in regard to insight into natural phenomena. He has unconsciously given the best description of himself in his famous saying: " No created mind can penetrate into the heart of Nature ; happy the man to whom she does but show the outer shell." Goethe made the best reply to this " shell theory " of observation in the noble poem which closes with the words: "'Nature has neither kernel nor shell; she is all one. Try yourself whether you are either kernel or shell." Yet there has been no lack, even of late years, of attempts to defend Haller's "shell theory." Wilhelm His, especially, has made a strange effort to justify it. Haller made a vigorous defence of the "evolution theory" in his famous work, Elementa physiologiae, affirming: "There is no such thing as formation (nulla est epigenesis ). No part of the animal frame is made before another; all were made together." He thus denied that there was anv evolution in the proper sense of the word, and even went so far as to say that the beard existed in the new-born child and the antlers in the hornless fawn; all the parts were there in advance, and were merely hidden from the eye of man for the time being. Haller even calculated the number of human beings that God must have created on the sixth day and stored away in Eve's ovary. He put the number at 200,000 millions, assuming the age of the world to be 6,000 years, the average age of a human being to be thirty years, and the population of the world at that time to be 1,000 millions. And the famous Haller maintained all this nonsense, in spite of its ridiculous consequences, even after Wolff had discovered the real course of embryonic development and established it by direct observation! Among the philosophers of the time the distinguished Leibnitz was the chief defender of the " preformation theorv," and by his authority and literary prestige won many adherents to it. Supported by his system of monads, according to which body and soul are united in inseparable association and by their union form the individual, or the "monad," Leibnitz consistently extended the " scatulation theory " to the soul, and held that this was no more evolved than the body. He says, for instance, in his Theodicec: " I mean that these souls, which one day are to be the souls of men, are present in the .seed, like those of other species; in such wise that they existed in our ancestors as far back as Adam, or from the beginning of the world, in the forms of organised bodies." The theory seemed to receive considerable support from the observations of one of its most zealous supporters, Bonnet. In 1745 lie discovered, in the plant-louse, a case of parthenogenesis, or virgin-birth, an interesting form of reproduction that has lately been found by Siebold and others among various classes of the articulata, especial ly crabs and insects. Among these and other animals of certain lower species the female may reproduce for several generations without having been fertilised by the male. These ova that do not need fertilisation are called " false ova," pseudova or spores. Bonnet saw that a female plant-louse, which he had kept in cloistral isolation, and rigidly removed from contact with males, had on the eleventh day (after forming a new skin for the fourth time) a living daughter, and during the next twenty days ninety-four other daughters ; and that all of them went on to reproduce in the same way without any contact with males. It seemed as if this furnished an irrefutable proof o( the truth of the scatulation theory, as it was held by the OvulistS ; it is not surprising to find that the theory then secured general acceptance. This was the condition of things when suddenlv, in 1759, Caspar Friedrich Wolff appeared, and dealt a fatal blow at the whole preformation theory with his new theory of epigenesis. Wolff, the son of a Berlin tailor, was born in 1733, and went through his scientific and medical studies, first at Berlin under the famous anatomist Meckel, and afterwards at Halle. Here he secured his doctorate in his twentysixth year, and in his academic dissertation (November 2<Sth, 1759) expounded the new theory of a real development, the theoria generationis, on a basis of epigenesis. This treatise is, in spite of its smallness and its obscure phraseology, one of the most valuable in the whole range of biological literature. It is equally distinguished for the mass of new and careful observations it contains, and the far-reaching and pregnant ideas which the author everywhere extracts from his observations and builds into a luminous and accurate theory of generation. Nevertheless, it met with no success at the time. Although scientific studies were then assiduously cultivated owing to the impulse given by Linne — although botanists and zoologists were no longer counted by dozens, but by hundreds, hardly any notice was taken of Wolff's theory. Even when he established the truth of epigenesis by the most rigorous observations, and demolished the airy structure of the preformation theory, the " exact " scientist Haller proved one of the most strenuous supporters of the old theory, and rejected Wolft's correct view with a dictatorial Nulla est epigenesis. He even went on to say that religion was menaced by the new theory ! It is not surprising that the whole of the physiologists of the second half of the eighteenth century submitted to the ruling of this physiological pontiff, and attacked the theory of epigenesis as a dangerous innovation. It was not until more than fifty years afterwards that Wolffs work was appreciated. Only when Meckel translated into German in 1812 another valuable work of Wolff's on The Formation of the Alimentary Canal (written in 1768), and called attention to its great importance, did people begin to think of him once more ; yet this obscure writer had evinced a profounder insight into the nature of the living organism than any other scientist of the eighteenth century. Thus, as has so often happened in the history of thought, the newly-discovered truth was crushed by the powerful untruth, supported by the might of authority. The luminous theory of epigenesis could not penetrate the mists of the preformation theory, and its gifted author succumbed to his enemies in the fight for truth. All further advance in embryology was thus prevented for the time being. It was the more unfortunate as Wolff was compelled by the poverty of his circumstances to leave Germany on account of this opposition. Henceforward without resources, he could only complete his classical work under the most pressing difficulties, and had then to earn his living by medical practice. During the Seven Years' War he worked in the hospitals of Schleswig, and gave brilliant lectures on anatomy in the field-hospital at Breslau, and so attracted the attention of the director-general of hospitals, Cothenius. At the conclusion of the war this patron endeavoured to obtain a professorship for Wolff at Berlin. But he failed, owing to the opposition of the narrow-minded professors of the Berlin Medicochirurgical College, who were ill-disposed to scientific progress. They declared the epigenesis theory to be a deadly heresy, just as they condemned the theory of descent only a few decades ago. Although Cothenius and other admirers struggled bravely for Wolff, they could not even get him permission to give public lectures on physiology at Berlin. In the end Wolff was compelled to accept an honourable position that was offered to him in 1766 by Catharine of Russia. He went to St. Petersburg, and continued his researches there for twenty-seven years. Wolff's ideas led to an appreciable advance over the whole field of biology. There is such a vast number of new and important observations and pregnant thoughts in his writings that we have only gradually learned to appreciate them rightly in the course of the nineteenth century. He opened up the true path for research in many directions. In the first place, his theory of epigenesis gave us our first real insight into the nature of embryonic development. He showed convincingly that the development of every organism consists of a series of new formations, and that there is no trace whatever of the complete form either in the ovum or the spermatozoon. On the contrary, these are quite simple bodies, with a very different purport. The embryo which is developed from them is also quite different, in its internal arrangement and outer configuration, from the complete organism. There is no trace whatever of preformation or in-folding of organs. To-day we can scarcely call epigenesis a theory, because we are convinced it is a fact, and can demonstrate it at any moment with the aid of the microscope. Alimentary Canal (i 768). In its complete state the alimentary canal of the hen is a long and complex tube, with which the lungs, liver, salivary glands, and many other small glands, are connected. Wolff showed that in the early stages of the embryonic chick there is no trace whatever of this complicated tube with all its dependencies, but instead of it only a flat, leaf-shaped body ; that, in fact, the whole embryo has at first the appearance of a flat, oval-shaped leaf. When we remember how difficult the exact observation of so fine and delicate a structure as the early leaf-shaped body of the chick must have been with the poor microscopes then in use, we must admire the rare faculty for observation which enabled Wolff to make the most important discoveries in this most difficult part of embryology. By this laborious research he reached the correct opinion that the embryonic body of all the higher animals, such as the birds, is for some time merely a flat, thin, leaf-shaped disk — consisting at first of one, but afterwards of several, layers. The lowest of these layers is the alimentary canal, and Wolff followed its development from its commencement to its completion. He showed how this leaf-shaped structure first turns into a groove, then the margins of this groove fold together and form a closed canal, and at length the two external openings of the tube (the mouth and anus) appear. Moreover, the important fact that the other systems of organs are developed in the same way, from tubes formed out of simple layers, did not escape Wolff. Hence, Wolff came to the view by 1768 which Pander developed in the Theory of Germinal Layers fifty years afterwards. The words in which Wolff anticipates the chief feature of this are so remarkable that they deserve to be quoted in full : — This wonderful analogy between parts that seem to be so widely removed from each other in Nature — no product of the imagination, but supported by the most confident observations — merits the attention of physiologists in the highest degree, for it must be admitted to have a profound significance, and to in' intimately connected with the generation and the nature of animals. It seems as if, at various and successive stages, different systems are formed after the same type, and those then unite to form the complete animal ; and as if these really resemble each other in spite of their differences. Tin- first system to be produced and take definite shape is the nervous system. When this is done, the mass of muscle which constitutes the embryo takes shape after the same fashion. To this succeeds a third system, that of the blood-vessels, which is not so unlike the first as to prevent us from seeing in it the form which is common to all three. After this comes the fourth, the alimentary canal, which again is constructed on the same type, and resembles the other three, in being a complete and self-contained whole. In this important discovery Wolff laid the foundation of the theory of germinal layers, which was not fully developed until much later by Pander (1817) and Baer (1828). Wolff's principles are not literally correct; but he comes as near to the truth in them as was possible at that time, and could be expected of him. Wolff owes a great deal of his success in forming his comprehensive theory to the fact that he was as distinguished in botany as in zoology. He studied at the same time the development of plants, and was the first to establish in botany the theory which Goethe afterwards developed in his famous work on the metamorphosis of plants. Wolff had already shown that all the different parts of the plant could be reduced to the leaf as the fundamental type. The flower and the fruit, with all their parts, are merely modified leaves. The knowledge of this must have much surprised Wolff, as he had found a simple leaf-shaped structure to be the first form of the embryonic body of the animal as well. Thus we find in Wolff the germs of the two theories which other and much later scientists were to make the basis of a morphological comprehension of the plant and the animal. But our admiration of this gifted genius increases when we find that he was also the precursor of the famous cellular theory. Wolff had, as Huxley showed, a clear presentiment of this cardinal theory, since he recognised small microscopic globules as the elementary parts out of which the germinal layers arose. Finally, I must invite special attention to the mechanical character of the profound philosophic reflections which Wolff always added to his remarkable observations. He was a great monistic philosopher, in the best meaning of the word. It is unfortunate that his philosophic discoveries were ignored as completely as his observations for more than half a century. We must be all the more careful to emphasise the fact of their clear monistic tendency. Karl Ernst von Baer as the chief successor to Wolff The Wiirtzburg school of embryologists : Dollinger, Pander, Baer. The disk-shaped germ divides first into two germinal layers, and these in turn sub-divide into two each. Their transformation into tubes. Baer's discovery of the human ovum, the germinal vesicle, and the axial rod. The lour types of development in the lour chief animal groups. Baer's law of the type of development and the Stage o( construction. Explanation of this law by the theory of selection. Baer's successors — Ralhke, Johannes Mtiller, Bischoff, Kolliker. The cellular theory — Schleiden, Schwann. Its application to embryology— Kemak. Reaction in embryology ; Reichert and His. The mechanical theories of His ; the " tailor theory " and the " theory of parablasts. " Chief embryo and secondary embryo. Symbiosis of the vertebrates. Mechanical explanation of the embryonic processes. The gastraea-theory. Homologyof the two primary layers. Protozoa and metazoa. Ccelenterata and coelomaria. The coslum-theory o( Hertwig. The four secondary embryonic layers. Progress in recent embryology. Experimental embryology. Mechanical embryology. We may distinguish three chief periods in the growth of our science of human embryology. The first has been considered in the preceding chapter; it embraces the whole of the preparatory period of research, and extends from Aristotle to Caspar Friedrich Wolff, or to the year 1759, in which the epoch-making Thcoria generationis was published. The second period, with which we have now to deal, lasts about a century — that is to say, until the appearance of Darwin's Origin of Species, which brought about a change in the very foundations of biology, and, in particular, of embryology. The third period begins with Darwin. When we say that the second period lasted a full century, we must remember that Wolff's work had remained almost unnoticed during half the time — namely, until the year 1812. During the whole of these fifty-three years not a single book that appeared followed up the path that Wolff had opened, or extended his theory o\ embryonic development. We merely find his views — perfectly correct views, based on extensive observations of fact— mentioned here and there as erroneous; their opponents, who adhered to the dominant theory of preformation, did not even deign to reply to them. This unjust treatment was chiefly due to the extraordinary authority of Albrecht von Haller; it is one of the most astonishing instances of a great authority, as such, preventing for a long time the recognition of established facts. The general ignorance of Wolff's work was so great that at the beginning of the nineteenth century two scientists of Jena, Oken (1806) and Kieser (1810), began independent research into the development of the alimentary canal of the chick, and hit upon the right clue to the embryonic puzzle, without knowing a word about Wolff's important treatise on the same subject. They were treading in his very footsteps without suspecting it. This can be easily proved from the fact that they did not travel as far as Wolff. It was not until Meckel translated into German Wolff's book on the alimentary system, and pointed out its great importance, that the eyes of anatomists and physiologists were suddenly opened. At once a number of biologists instituted fresh embryological inquiries, and began to confirm Wolff's theory of epigenesis. This resuscitation of embryology and development of the epigenesis-theory was chiefly connected with the university ot Wiirtzburg. One of the professors there at that time was Dollinger, an eminent biologist, and father of the famous Catholic historian who later distinguished himself by his opposition to the new dogma of papal infallibility. Dollinger was both a profound thinker and an accurate observer. He took the keenest interest in embryology, and worked at it a good deal. However, he is not himself responsible for any important result in this field. In 1816 a young medical doctor, whom we may at once designate as Wolff's chief successor, Karl Ernst von Baer, came to Wiirtzburg. Baer's conversations with Dollinger on embryology led to a fresh series of most extensive investigations. Dollinger had expressed a wish that some young scientist should begin again under his guidance an independent inquiry into the MOPKhW KMRRYOLOG Y development of the chick during the hatching of the egg. As neither he nor Baer had money enough to pay for an incubator and the proper control of the experiments, and for a competent artist to illustrate the various stages observed, the lead of the enterprise was given to Christian Pander, a wealthy friend of Baer's, who had been induced by Baer to come to Wiirtzburg. An able engraver, Dalton, was engaged to do the copper-plates. Thus was formed, in the words of Baer, "an association of memorable importance to science, in which a veteran of physiological research (Dollinger), an ardent scientific neophyte (Pander), and an unrivalled artist (Dalton), joined forces in order to provide a firm foundation for the embryology of the animal organism." In a short time the embryology of the chick, in which Baer was taking the greatest indirect interest, was so far advanced that Pander was able to sketch the main features of it on the ground of Wolffs theory in the dissertation he published in 1817. He clearly enunciated the theory of germinal layers which Wolff had anticipated, and established the truth of Wolff's idea of a development of the complicated systems of organs out of simple leaf-shaped primitive structures. According to Pander, the leaf-shaped object in the hen's egg divides, before the incubation has proceeded twelve hours, into two different layers, an external serous layer and an internal mucous layer; between the two there developes later a third layer, the vascular (blood-vessel) layer.1 Karl Ernst von Baer, who had set afoot Pander's investigation, and had shown the liveliest interest in it after Pander's departure from Wiirtzburg, began his own much more comprehensive research in 1819. He published the mature result nine years afterwards in his famous work, Animal Embryology : Observation and Reflection (not translated). This classic work still remains a model of careful observation united to profound philosophic speculation. The first part appeared in 1828, the second in 1837. The book proved to be the foundation on which the whole science of embryology has built down to our own day. It so far surpassed its predecessors, and Pander in particular, that it has become, after Wolff's work, the chief base of modern embryology. As Baer was one of the greatest scientists of the nineteenth century, and exercised considerable influence on other branches of biology as well, it will be interesting to add a few points with regard to his life. Karl Ernst von Baer was born at Esthland, in Piep, a small estate belonging to his father, in 1794. He studied from 1810 to 1814 at Dorpat, and went from there to Wiirtzburg, where Dollinger not only initiated him to comparative anatomy and embryology, but had a very beneficial general influence over him in the way of scientific method. From Wiirtzburg he went to Berlin, and then, at the invitation of the physiologist Burdach, to Konigsberg, where, with few interruptions, he lectured on zoology and embryology until 1834, ar,d wrote his chief works. . In 1834 he went to St. Petersburg and became a member of the academy of that city. Here he almost deserted his earlier field, and engaged in various kinds of research of a quite different character, especially in geography, geology, ethnography, and anthropology. During the last forty years his general views gradually altered, as I have described in my Riddle of the Universe. In earlier years he had been a consistent supporter of the monistic system. He had in his chief work (especially in the preface and at the close) insisted on the unity and naturalness of evolution. But in later years he leaned more and more to mystical and teleological considerations; and, in the end, his anthropistic dualism led him to embrace a curious form of theology. He spent his last years at Dorpat, where he died in 1876. His most important works are certainly those dealing with animal embryology, and were all written in Konigsberg, though partly published elsewhere. Their great service extends, like that of Baer, over the whole field of embryology in many different directions. Starting-point of ontogenetic research ever since. He taught that in all the vertehrates first two and then four of these germinal layers are formed; and that the earliest rudimentary organs o( the body arise by the conversion of these layers into tubes. He described the first appearance of the vertebrate embryo, as it may be seen in the globular yelk of the fertilised egg, as an oval disk which first divides into two layers. From the upper or animal layer are developed all the organs which accomplish the phenomena of animal life — the functions of sensation and motion, and the covering of the body. From the lower or vegetative layer come the organs which effect the vegetative life of the organism — nutrition, digestion, blood-formation, respiration, secretion, reproduction, etc. Each of these original layers divides, according to Baer, into two thinner and superimposed layers or plates. He calls the two plates of the animal layer, the skin-stratum and muscle-stratum. From the upper of these plates, the skinstratum, the external skin, or outer covering of the body, the central nervous system, and the sense-organs, are formed. From the lower, or muscle-stratum, the muscles, or fleshy parts and the bony skeleton — in a word, the motor organs — are evolved. In the same way, Baer said, the lower or vegetative layer splits into two plates, which he calls the vascular-stratum and the mucous-stratum. From the outer of the two (the vascular) the heart, blood-vessels, spleen, and the other vascular glands, the kidneys, and sexual glands, are formed. From the fourth or mucous layer, in fine, we get the internal and digestive lining of the alimentary canal and all its dependencies, the liver, lungs, salivary glands, etc. Baer had, in the main, correctly judged the significance of these four secondary embryonic lavers, and he followed the conversion of them into the tube-shaped primitive organs with great perspicacity. He first solved the difficult problem of the transformation of this four-fold, flat, leaf-shaped, embryonic disk into the complete vertebrate body, through the conversion of the layers or plates into tubes. The flat leaves bend themselves in obedience to certain laws of growth; the borders of the curling plates approach nearer and nearer; until at last they come into actual contact. Thus out of the flat gut-plate is formed a hollow gut-tube, out of the flat spinal plate a hollow nerve-tube, from the skin-plate a skin-tube, and so on. Among the many great services which Baer rendered to embryology, especially vertebrate embryology, we must not forget his discovery of the human ovum. Earlier scientists had, as a rule, of course, assumed that man developed out of an egg, like the other animals. In fact, the preformation theory held that the germs of the whole of humanity were stored already in Eve's ova. But the real ovum escaped detection until the year 1827. This particle is formed in the ovary inside a much larger globule, which takes the name of the Graafian follicle, from its discoverer, Graaf, and had previously been regarded as the true ovum. However, in 1827 Baer proved that it was not the real ovum, which is much smaller, and is contained within the follicle. (Compare the end of the twenty-ninth chapter.) Baer was also the first to observe what is known as the segmentation sphere of the vertebrate ; that is to say, the globular vesicle which first developes out of the impregnated ovum, and the thin wall of which is made up of a single layer of regular, polygonal (many-cornered) cells (see the illustration in the twelfth chapter). Another discovery of his that was of great importance in constructing the vertebrate stem and the characteristic organisation of this extensive group (to which man belongs) was the detection of the axial rod, or the chorda dorsalis. This is a long, round, cylindrical rod of cartilage which runs down the longer axis of the vertebrate embryo ; it appears at an early stage, and is the first sketch of the spinal column, the solid skeletal axis of the vertebrate. In the lowest of the vertebrates, the amphioxus, the internal skeleton consists only of this cord throughout life. But even formed. However, important as these and many other discoveries of Baer's were in vertebrate embryology, his researches were even more influential, from the circumstance that he was the first to employ the comparative method in studying the development of the animal frame. Baer occupied himself chiefly with the embryology of vertebrates (especially the birds and fishes). But he by no means confined his attention to these, gradually taking the various groups of the invertebrates into his sphere of study. As the general result of his comparative embrvological research, Baer distinguished four different modes of development and four corresponding groups in the animal world. These chief groups or types are: i, the vertebrata ; 2, the articulata ; 3, the mollusca ; and 4, all the lower groups which were then wrongly comprehended under the general name of the radiata. Georges Cuvier had been the first to formulate this distinction, in 1812. He showed that these groups present specific differences in their whole internal structure, and the connection and disposal of their systems of organs ; and that, on the other hand, all the animals of the same type — say, the vertebrates — essentially agreed in their inner structure in spite of the greatest superficial differences. But Baer proved that these four groups are also quite differently developed from the ovum ; and that the series of embryonic forms is the same throughout for animals of the same type, but different in the case of other animals. Up to that time the chief aim in the classification of the animal kingdom was to arrange all the animals from lowest to highest, from the infusorium to man, in one long and continuous series. The erroneous idea prevailed nearly everywhere that there was one uninterrupted chain of evolution from the lowest animal to the highest. Cuvier and Baer proved that this view was false, and that we must distinguish four totally different types of animals, on the ground of anatomic structure and embryonic development. The development of an individual of any animal type is characterised by two features : firstly, by the progressive construction of the animal body through a continuous histological and morphological segmentation ; secondly, by an advance from a more general to a more special form of structure. The degree of development of the organism consists in the greater or less measure of the heterogeneity of its elementary parts and of the several sections of its connected system ; in other words, in its greater histological and morphological subdivision (or differentiation). On the other hand, the type consists in the disposition of the organic elements in the organs. The type is an entirely different thing from the degree of development ; the same type may be found in various stages of development, and, vice versfi, the same stage of development may be had in different types. Hence it is that the most advanced animals of each type — for instance, the highest articulata and mollusca — are much more highly organised (or more effectively differentiated) than the lowest animals of every other type, such as the lowest vertebrates and the echinoderms. This law of Baer has proved of great service in our study of animal organisation, although we were not in a position to understand and appreciate its real significance until Darwin appeared. I may add that a thorough comprehension of it is only possible in the light of the theory of descent, and after recognising the important part that heredity and adaptation play in the production of organic forms. As I showed in my Generelle Morphologie (Band II., § 10), the type of development is a mechanical result of heredity ; but the degree of development is a mechanical consequence of adaptation. Heredity and adaptation are the mechanical agents in organic construction which Darwin's theory of selection introduced into embryology, and through which we have at last come to understand Baer's law. Baer's epoch-making works aroused an extraordinary and widespread interest in embryological research. Immediately afterwards we find a great number of observers at work in the newly opened field, enlarging it in a very short time with great energy by their various discoveries in detail. Next to Baer's comes the admirable work of Heinrich Rathke, of Konigsberg (died i860) ; he made an extensive study of the embryology, not only of the invertebrates (crabs, insects, molluscs), but also, and particularly, of the vertebrates (fishes, tortoises, serpents, crocodiles, etc.). We owe the first comprehensive studies of mammal embryology to the careful research of Wilhelm Bischoff, of Munich ; his embryology of the hare (1S40), the dog (1842), the guineapig (1852), and the doe (1854), st'" f°rm classical studies. About the same time a great impetus was given to the embryology of the invertebrates. The way was opened through this obscure province by the studies of the famous Berlin zoologist, Johannes Miiller, on the echinoderma. I le was followed by Albert Kolliker, of Wiirtzburg, writing on the cuttle-fish (or the cephalopods), Siebold and Huxley Oil worms and zoophytes, Fritz Miiller (Desterro) on the Crustacea, Weismann on insects, and so on. The number of workers in this field has greatly increased of late, and a quantity of new and astonishing discoveries have been made. One notices, in several of these recent works on embryology, that their authors are too little acquainted with comparative anatomy and classification. Paleontology is, unfortunately, altogether neglected by many of these new workers, although this interesting science furnishes most important facts for phylogeny, and thus often proves of very great service in ontogeny. A very important advance was made in our science in 1839, when the cellular theory was established, and a new field of inquiry bearing on embryology was suddenly opened. When the famous botanist, M. Schleiden, of Jena, showed in 1838, with the aid of the microscope, that every plant was made up of innumerable elementary parts, which we call cells, a pupil of Johannes Miiller at Berlin, Theodor Schwann, applied the discovery at once to the animal organism. He showed that in the animal body as well, when we examine its tissues in the microscope, we find these cells everywhere to be the elementary units. All the different tissues of the organism, especially the very dissimilar tissues of the nerves, muscles, bones, external skin, mucous lining etc., are originally formed out of cells; and this is also true of all the tissues of the plant. These cells are separate living beings; they are the citizens of the State which the entire multicellular organism seems to be. This important discovery was bound to be of service to embryology, as it raised a number of new questions. What is the relation of the cells to the germinal layers? Are the germinal layers composed of cells, and what is their relation to the cells of the tissues that form later? How does the ovum stand in the cellular theory ? Is the ovum itself a cell, or is it composed of cells? These important questions were now imposed on the embryologist by the cellular theory. The most notable effort to answer these questions — which were attacked on all sides by different students — is contained in the famous work, Inquiries into the Development of the Vertebrates (not translated) of Robert Remak, of Berlin (1851). This gifted scientist succeeded in mastering, by a complete reform of the science, the great difficulties which the cellular theory had at first put in the way of embryology. A Berlin anatomist, Carl Boguslaus Reichert, had already attempted to explain the origin of the tissues. But this attempt was bound to miscarry, since its not very clearheaded author lacked a sound acquaintance with embryology and the cell theory, and even with the structure and development of the tissue in particular. An examination of Reichert's discoveries shows how inaccurate his observations were, and how false the conclusions he drew from them. I need only give one illustration : he believed the whole of the outer germinal layer, from which the most important organs are developed (the brain, spinal cord, skin, etc.), to be only a temporary integument of the embryo, which had nothing to do with the actual construction of the organism. According to him, the forms of the various organs did not come for the most part from the original germinal layers, but arose independently of these out of the yelk, and were only gradually joined to the layers. Reichert's perverse studies of embryology only obtained a certain amount of passing attention through the audacious way in which they were pushed and the attack he made on Baer's theory of the germinal layers ; and, in fact, they were so badly presented that nobody really understood them. However, on that very account they won the admiration of a good many readers, who felt that there must be some fund of wisdom at the back of all these cloudy oracles and mysteries. We see the same thing here and there to-day, especially as regards the confused writings of the "mechanical embryologists " (such as Dreisch and his colleagues). Remak at length brought order into the dreadful confusion that Reichert had caused; he gave a perfectly simple explanation of the origin of the tissues. In his opinion the animal ovum is always a simple cell : the germinal layers which develop out of it are always composed of cells ; and these cells that constitute the germinal layers arise simply from the continuous and repeated cleaving (segmentation) of the original solitary cell. It first divides into two and then into four cells ; out of these four cells are born eight, then sixteen, thirty-two, and so on. Thus, in the embryonic development of everv animal and plant there is formed first of all out of the simple egg cell, by a repeated sub-division, a cluster of cells, as Kolliker had already stated in connection with the cephalopods in 1844. The cells of this group spread themselves out flat and form leaves or plates ; each of these leaves is formed exclusively out of cells. The cells of different layers assume different shapes, increase, and differentiate ; and in the end there is a further cleavage (differentiation) and division of work (ergonomy) of the cells within the layers, and from these all the different tissues of the body proceed. These are the simple foundations of histogeny, or the science that treats of the development of the tissues (hista)y as it was established by Remak and Kolliker. Remak, in determining more closely the part which the different germinal layers play in the formation of the various tissues and organs, and in applying the theory of epigenesis to the cells and the tissues they compose, raised the theory of germinal layers, at least as far as it regards the vertebrates, to a high degree of perfection. structure of the vertebrate body (or the " germinal disk "), as the lower layer splits into two plates. These three layers have a very definite relation to the various tissues. First of all, the cells which form the outer skin of the body (the epidermis), with its various dependencies (hairs, nails, etc.) — that is to say, the entire outer envelope of the body — are developed out of the outer or upper layer; but there are also developed in a curious way out of the same layer the cells which form the central nervous system, the brain and the spinal cord. In the second place, the inner or lower germinal layer gives rise only to the cells which form the epithelium (the whole inner lining) of the alimentary canal and all that depends on it (the lungs, liver, pancreas, etc.), or the tissues that receive and prepare the nourishment of the body. Finally, the middle layer gives rise to all the other tissues of the body, the muscles, blood, bones, cartilage, etc. Remak further proved that this middle layer, which he calls " the motorgerminative layer," proceeds to sub-divide into two secondary layers. Thus we find once more the four layers which Baer had indicated. Remak calls the outer secondary leaf of the middle layer (Baer's " muscular layer") the "skin layer" (it would be better to say, skin-fibre layer) ; it forms the outer wall of the body (the true skin, the muscles, etc.). To the inner secondary leaf (Baer's " vascular layer ") he gave the name of the "alimentary-fibre layer"; this forms the outer envelope of the alimentary canal, with the mesentery, the heart, the blood-vessels, etc. On this firm foundation provided by Remak for histogeny, or the science of the formation of the tissues, our knowledge has been gradually built up and enlarged in detail. The two anatomists, Reichert (of Berlin) and Wilhelm His (of Leipzic), especially, have endeavoured in their works to introduce a new conception of the embryonic development of the vertebrate, according to which the two primary germinal layers would not be the sole sources of formation. But these efforts were so seriously marred by ignorance of comparative anatomy, an imperfect acquaintance with ontogenesis, and a complete neglect of phylogenesis, that they could not have more than a passing success. We can only explain how these curious attacks of Reichert and His came to be regarded for a time as advances by the general lack of discrimination and of grasp of the true object o( embryology. Wilhelm His published, in 186S, his extensive Researches into the Earliest Form of the Vertebrate Body,1 one of the curiosities of embrvological literature. The author imagines that he can build a " mechanical theory of embryonic development " by merely giving an exact description of the embryology of the chick, without any regard to comparative anatomy and phylogeny, and thus falls into an error that is almost without parallel in the history of biological literature. As the final result of his laborious investigations, His tells us "that a comparatively simple law of growth is the one essential thing in the first development. Every formation, whether it consist in cleavage of layers, or folding, or complete division, is a consequence of this fundamental law." Unfortunately, he does not explain what this " law of growth " is; just as other opponents of the theory of selection, who would put in its place a great "law of evolution," omit to tell us anything about the nature of this. Nevertheless, it is quite clear from His's works that he imagines constructive Nature to be a sort of skilful tailor. The ingenious operator succeeds in bringing into existence, by " evolution," all the various forms of living things by cutting up in different ways the germinal layers, bending and folding, tugging and splitting, and so on. Bending and folding, especially, play an important part in this sartorial theory of embryology. " Not only the division of head from trunk, stem from periphery, but even the form of the members and the separation of the brain, the senseorgans, the primitive vertebral column, the heart, and the rudimentary bowels, can be proved convincingly to be mechanical consequences of the first folding process." The funniest part of it is when the tailor comes to fashion the two pairs of limbs: " The form is like the four corners of a letter, obtained by the crossing of four folds that surround the body." But this "envelope theory" is surpassed by the " rag-bag theory " with which His explains the rudimentary organs: "Organs (such as the hypophysis or the thyroid gland) for which no physiological function has yet been found; they are embryonic remnants, which we might compare to the superfluous pieces that are left over when a coat is cut out even in the most economic fashion " (!). So our Nature-tailor now throws her leavings into the rag-bag. If our skull-less ancestors of the Silurian period had had any presentiment of such vagaries as these on the part of their human successors, they would certainly have preferred to abandon altogether the ciliated groove at their gill-openings, rather than pass it on to the amphioxus, and thus leave us the equivocal gift of the thyroid gland (which becomes the dreaded goitre when it is morbidly enlarged). But the most important and extensive of the embryological theories of His was his famous " theory of the parablasts." According to this, the human body (and that of all other vertebrates) is made up at first of two different organisms, which arise from two entirely separate embryonic structures, the chief embryo and the secondary embryo. It is only the chief embryo, or the " Archiblast," that developes from the fertilised ovum, and is built from the two primary germinal layers which are formed by its repeated sub-division. On the other hand, the secondary embryo, or the " Parablast," is formed, not out of the germinal layers, but from parts of the white yelk ; the cells which compose it come from the follicle-cells of the membrana granulosa, and have passed from the ovary into the yelk. Hence the parablast is an additional gift from the mother, the archiblast alone coming from both parents, as a product of the fertilised ovum, and transmitting their features to the offspring. From this secondary embryo are developed (parthenogenetically) the tissues of the blood-vessels and the connective parts (bones, cartilages, etc.) ; while all the other tissues of the vertebrate body are formed from the sexually-produced MODEKX EM II MYOLOGY chief embryo. The two embryos are at first quite independent, " sharply distinguished, not only in regard to origin, but also from the histological and physiological points of view." Thus the vertebrate organism is a double being, formed by the " symbiosis," or the gradual coalescence, of two animals that were at first distinct. As the lichen is made up of two distinct plants, a fungus and an alga, so, according to His, every vertebrate is composed of two separate animals, an archiblast and a parablast. I have pointed out in my essay on The Origin and Development of the Animal Tissues (1884) the far-reaching consequences that would follow from this "symbiosis of the vertebrate." This parablast theory, like His's other embryological theories, excited a good deal of interest at the time of its publication, and has evoked a fair amount of literature in the last few decades. His professed to explain the most complicated parts of organic construction (such as the development of the brain) in the simplest way on mechanical principles, and to derive them immediately from simple physical processes (such as unequal distribution of strain in an elastic plate). It is quite true that a mechanical or monistic explanation (or a reduction of natural phenomena to physical and chemical processes) is the ideal of modern science, and this ideal would be realised if we could succeed in expressing these formative processes in mathematical formulae. His has, therefore, inserted plenty of numbers and measurements in his embryological works, and given them an air oi "exact" scholarship by putting in a quantity of mathematical tables. Unfortunately, they are of no value, and do not help us in the least in forming an "exact" acquaintance with the embryonic phenomena. Indeed, they wander from the true path altogether by neglecting the phylogenetic method; this, he thinks, is "a mere by-path," and is " not necessary at all for the explanation of the facts ol embryology," which are the direct consequence of physiological principles. What His takes to be a simple physical process — for instance, the folding o( the germinal layers (in the formation of the medullary tube, alimentary tube, etc.) — is, as a matter of fact, the direct result of the growth of the various cells which form those organic structures ; but these growth-motions have themselves been transmitted by heredity from parents and ancestors, and are only the hereditary repetition of countless phylogenetic changes which have taken place for thousands of years in the race-history of the said ancestors. Each of these historical changes was, of course, originally due to adaptation ; it was, in other words, physiological, and reducible to mechanical causes. But we have, naturally, no means of observing them now. It is only by the hypotheses of the science of evolution that we can form an approximate idea of the organic links in this historic chain. I have contrasted these phylogenetic theories with the pseudomechanical theories of His in my essay on The Aims and Methods of Modern Embryology (1875). I have also given in this essay a criticism of the curious theories of evolution which Alexander Goette has put forward in his comprehensive and finely illustrated study (1875) of the development of the ringed-snake ; and of the religious and mystic views of Louis Agassiz. Such vagaries as these are scarcely possible in any other science to-day. That they crop up in the science of embryology is due in part to the extreme difficulty and intricacy of its object, and in part to the inadequate training of many of the workers in this field. In fine, it is worth noting that, though His's pseudo-mechanical method has (like the very different method of Goette) been much admired, it has not been developed or applied with any success by any other scientist. No results of any value have been attained by it. All the best recent research in animal embryology has led to the confirmation and development of Baer and Remak's theory of the germinal layers. One of the most important advances in this direction of late was the discovery that the two primary layers out of which is built the body of all vertebrates (including man) are also present in all the invertebrates, with the sole exception of the lowest group, the unicellular protozoa. Huxley had detected them in the medusa in 1S49. lie showed that the two layers of cells from which the body of this zoophyte is developed correspond, both morphologically and physiologically, to the two original germinal layers of the vertebrate. The outer layer, from which come the external skin and the muscles, was then called by Allman (1853) the "ectoderm" ( outer layer, or skin) ; the inner layer, which forms the alimentary and reproductory organs, was called the "entoderm" (= inner layer). In 1867 and the following years the discovery of the germinal layers was extended to other groups of the invertebrates. In particular, the indefatigable Russian zoologist, Kowalevsky, found them in all the most diverse sections of the invertebrates — the worms, tunicates, echinoderms, molluscs, articulates, etc. In my monograph on the sponges (1872) I myself proved that these two primary germinal layers are also found in that group, and that they may be traced from it right up to man, through all the various classes, in analogous (or homologous) form. This " homology of the two primary germinal layers " extends through the whole of the metazoa, or tissue-forming animals ; that is to say, through the whole animal kingdom, with the one exception of its lowest section, the unicellular beings, or protozoa. These lowly organised animals do not form germinal layers, and therefore do not succeed in forming true tissue. Their whole body consists of a single cell (as is the case with the amceba; and infusoria), or of a loose aggregation of only slightly differentiated cells, though it may not even reach the full structure of a single cell (as with the monera). But in all other animals the ovum first grows into two primary layers, the outer or animal layer (the ectoderm, epiblast, or ectoblast), and the inner or vegetal layer (the entoderm, hvpoblast, or endoblast) ; and from these the tissues and organs are formed. The first and oldest organ of all these metazoa is the primitive gut (or progaster) and its opening, the primitive mouth (prostoma). The typical embryonic form of the metazoa, as it is presented for a time by this simple structure of the two-layered body, is called the gastrula ; it is to be conceived as the hereditary reproduction of some primitive common ancestor of the metazoa, which we call the gastrcea. This applies to the sponges and other zoophyta, and to the worms, the mollusca, echinoderma, articulata, and vertebrata. All these animals may be comprised under the general heading of "gut animals," or metazoa, in contradistinction to the gutless protozoa. I have pointed out in my Study of the Gastrcea Theory [not translated] (1873) the important consequences of this conception in the morphology and classification of the animal world. I also divided the realm of metazoa into two great groups, the lower and higher metazoa. In the first are comprised the ccelenterata (also called zoophytes, or " plant-animals "). In the lower forms of this group the body consists throughout life merely of the primary germinal layers, with the cells sometimes more and sometimes less differentiated ; this is the case with the gastrasads, the simpler sponges (protospongia), the hydropolyps, and the lower medusje. But with the higher forms of the ccelenterata (the corals, higher medusa;, ctenophora, and platodes) a middle layer, or mesoderm, often of considerable size, is developed between the other two layers ; but blood and an internal cavity are still lacking. To the second great group of the metazoa I gave the name of the coelomaria, or bilaterata (or the bilateral higher forms). They all have a cavity within the body (cceloma), and most of them have blood and blood-vessels. In this are comprised the six higher stems of the animal kingdom, the annulata and their descendants, the mollusca, echinoderma, articulata, tunicata, and vertebrata. In all these bilateral organisms the two-sided body is formed out of four secondary germinal layers, of which the inner two construct the wall of the alimentary canal, and the outer two the wall of the body. Between the two pairs of layers lies the cavity (cceloma). Although I laid special stress on the great morphological importance of this cavity in my Study of the Gastrcea Theory, and endeavoured to prove the significance of the four secondary germinal layers in the organisation of the ccelomaria, I was unable to deal satisfactorily with the difficult question of the MODERN EM UK YOI.OCY mode of their origin. This was done eight years afterwards by the brothers Oscar and Richard Hertwig in their careful and extensive comparative studies. In their masterly Cesium Theory: An Attempt to Explain the Middle Germinal Layer [not translated] (1881) they showed that in most of the metazoa.especially in all the vertebrates, the body-cavity arises in the same way, by the turning up of two of the entoderm sacs. These two ccelum-pouehes grow out from the rudimentary mouth of the gastrula, between the two primary layers. The inner plate of the two-layered ccelum-pouch (the visceral layer) joins itself to the entoderm ; the outer plate (parietal layer) unites with the ectoderm. Thus are formed the double-layered gut-wall within and the doublelayered body-wall without; and between the two is formed the cavity of the ccelum, by the blending of the right and left cojlum-sacs. The many new points of view and fresh ideas suggested by my gastnea theory and Hertwig's ccelum theorv led to the publication of a number of writings on the theory of germinal layers. Most of them set out to oppose it at first, but in the end the majority supported it. Of late years both theories are accepted in their essential features by nearly every competent man of science, and light and order have been introduced into this once dark and contradictory field of research. A further cause of congratulation for this solution of the great embryological controversy is that it brought with it a recognition of the need for phylogenetic Study and explanation. Interest and practice in embryological research have been remarkably stimulated during the past thirty years by this appreciation of phylogenetic methods. Hundreds of assiduous and able observers are now engaged in the development of comparative embryology and its establishment on a basis of evolution, whereas they numbered only a few dozen not many decades ago. It would take too long to enumerate even the most important of the countless valuable works which have enriched embryological literature since that time. References to them will be found in the latest manuals of schelt, and Heider. Kolliker's Entwickelitngsgeschichte des Menschen und der hbherer Thiere, the first edition of which appeared forty-two years ago, had the rare merit at that time of gathering into presentable form the scattered attainments of the science, and expounding them in some sort of unity on the basis of the cellular theory and the theory of germinal layers. Unfortunately, the distinguished Wiirtzburg anatomist, to whom comparative anatomy, histology, and ontogeny owe so much, is opposed to the theory of descent generally and to Darwinism in particular. In the latest edition of his work (1884) he rejected the evolutionary significance of the facts of embryology, as I pointed it out, and the gastraea theory. On the other hand, he subscribes (though less fully of late years) to the theories of His, and has contributed a good deal by his great authority to the prestige they enjoyed for a time. All the other manuals I have mentioned take a decided stand on evolution. Francis Balfour has carefully collected and presented with discrimination, in his Manual of Comparative Embryology (1880), the very scattered and extensive literature of the subject ; he has also widened the basis of the gastrasa theory by a comparative description of the rise of the organs from the germinal layers in all the chief groups of the animal kingdom, and has given a most thorough empirical support to the principles I have formulated. A comparison of his work with the excellent Text-book of the Embryology of the Vertebrates (1890) [translation, 1895] of Korschelt and Heider shows what astonishing progress has been made in the science in the course of ten years. I would especially recommend the manuals of Julius Kollman and Oscar Hertwig to those readers who are stimulated to further study by these chapters on human embryology. Kollmann's Lehrbuch der entwickelungsgeschichte des Menschen (1898) is commendable for its clear treatment of the subject and very fine original illustrations; its author adheres firmly to the biogenetic law, and uses it throughout with considerable profit. That is not the case in Oscar Hertwig's recent Text-book of the Embryology of Man and the Mammals [translations [892 and 1899) (seventh edition, 1902). This ahle anatomist lias of late often been quoted as an opponent of the biogenetic law, although he himself had demonstrated its great value thirty years ago in his Untersuchungen uber Bait und Entwickelung der Plakoidschuppen. His recent vacillation is partly due to the timidity which our "exact " scientists have with regard to hypotheses; though it is quite impossible to make any headway in the explanation of facts without them. However, the purely descriptive part of embrvologv in Hertwig's Text-book is very thorough and reliable. A shorter account is given in his Elemente der Entwickelungslehre (Jena, 1900), and a very good summary of special work done by many authors in his Handbuch der vergleichenden und experimentellen Entwickelungslehre der Wirbelthiere (Jena, 1901). A new branch of embrvological research has been studied very assiduously in the last decade of the nineteenth century — namely, " experimental embryology." The great importance which has been attached to the application of physical experiments to the living organism for the last hundred years, and the valuable results that it has given to physiology in the study of the vital phenomena, have led to its extension to embryology. I was the first to make experiments of this kind during a stay of four months on the Canary Island, Lanzerote, in 1866. I there made a thorough investigation of the almost unknown embryology of the siphonophora. 1 cut a number of the embryos of these animals (which develop freely in the water, and pass through a very curious transformation), at an early stage, into several pieces, and found that a fresh organism (more or less complete, according to the size of the piece) was developed from each particle. I have given illustrations of the curious larva (sometimes of quite monstrous shapes) which form from them on plates 11-14 °f m.v Entwickelungsgeschichte der Siphonophoren (Utrecht, 1869). More recently some of my pupils have made similar experiments with the embryos of vertebrates (especially the frog) and some of the invertebrates. Wilhelm Roux, in particular, has made extensive experiments, and based on them a special "mechanical embryology," which has given rise to a good deal of discussion and controversy. Roux has published a special journal for these subjects since 1895, the Archiv fur Entmickelungsmechanik. The contributions to it are very varied in value. Many of them are valuable papers on the physiology and pathology of the embryo. Pathological experiments — the placing of the embryo in abnormal conditions — have yielded many interesting results ; just as the physiology of the normal body has for a long time derived assistance from the pathology of the diseased organism. Other of these mechanical-evolutionary articles return to the erroneous methods of His, and are only misleading. This must be said of the many contributions of mechanical embryology which take up a position of hostility to the theory of descent and its chief embryological foundation — the biogenetic law. This law, however, when rightly understood, is not opposed to, but is the best and most solid support of, a sound mechanical embryology. Impartial reflection and a due attention to paleontology and comparative anatomy should convince these one-sided mechanicists that the facts they have discovered — and, indeed, the whole embryological process — cannot be fully understood without the theory of descent and the biogenetic law. Evolution before Darwin. The origin of species. Carl Linne gives a definition of species and genus, and associates it with the Biblical story of creation. The deluge. Paleontology. The catastrophic theory of Georges Cuvier. Repeated revolutions on earth and fresh creations. Lyell's theory of continuity. The natural causes of the gradual formation of the earth. Supernatural origin of living things. Dualistic natural philosophy of Immanuel Kant. Monistic natural philosophy of Jean Lamarck. His life. His Philosophic Zoologique. The first scientific treatment of evolution. Transformation of organs by use and habit, together with heredity. Application of the theory to man. Descent of man from the ape. Wolfgang Goethe. His scientific studies. His morphology. His studies on the formation and transformation of organic natures. Goethe's theory of the impulse to specification (heredity) and metamorphosis (adaptation). Tin-: embryology of man and the animals, the historv of which we have reviewed in the last two chapters, was mainly a descriptive science forty years ago. The earlier investigations in this province were chiefly directed to the discovery, by careful observation, of the wonderful facts of the embryonic development of the animal body from the ovum. Forty years ago no one dared attack the question of the causes of these phenomena. For fully a century, from the year 1759, when Wolffs solid Theoria generation is appeared, until 1859, when Darwin published his famous Origin of Species, the real causes of the embryonic processes were quite unknown. No one thought of seeking the agencies that effected this marvellous succession of structures. The task was thought to be so difficult as almost to pass beyond the limits of human thought. It was reserved for Charles Darwin to initiate us into the knowledge of these causes. This compels us to recognise in this great genius, who wrought a complete revolution in the whole field of biology, a founder at the same time of a new period in embryology. It is true that Darwin occupied himself very little with direct embryological research, and even in his chief work he only touches incidentally on the embryonic phenomena ; but by his reform of the theory of descent and the founding of the theory of selection he has given us the means of attaining to a real knowledge of the causes of embryonic formation. That is, in my opinion, the chief feature in Darwin's incalculable influence on the whole science of evolution. When we turn our attention to this latest period of embryological research, we pass into the second division of organic evolution — stem-evolution, or phylogeny. I have already indicated in the first chapter the important and intimate causal connection between these two sections of the science of evolution — between the evolution of the individual and that of his ancestors. We have formulated this connection in the biogenetic law; the shorter evolution, that of the individual, or ontogenesis, is a rapid and summary repetition, a condensed recapitulation, of the larger evolution, or that of the species. In this principle we express all the essential points relating to the causes of evolution ; and we shall seek throughout this work to confirm this principle and lend it the support of facts. When we look to its causal significance, perhaps it would be better to formulate the biogenetic law thus: "The evolution of the species and the stem (phvlon) shows us, in the physiological functions of heredity and adaptation, the conditioning causes on which the evolution of the individual depends"; or, more briefly: " Phylogenesis is the mechanical cause of ontogenesis." We owe it to Darwin that we are now in a position to trace and appreciate these hitherto obscure causes of embryonic development, and so we give his name to a new period in embryology. But before we examine the great achievement by which Darwin revealed the causes of evolution to us, we must glance at the efforts of earlier scientists to attain this object. Our historical inquiry into these will be even shorter than that into the work done in the field of ontogeny. We have very few names to consider here. At the head of them we find the great French naturalist, Jean Lamarck, who first established evolution as a scientific theory in 1809. Even before his time, however, the chief philosopher, Kant, and the chief poet, Goethe, of Germany had occupied themselves with the subject. But their efforts passed almost without recognition in the eighteenth century. A "philosophy of nature "did not arise until the beginning of the nineteenth century. In the whole of the time before this no one had ventured to raise seriously the question of the origin of species, which is the culminating point of phylogeny. On all sides it was regarded as an insoluble enigma. The whole science of the evolution of man and the other animals is intimately connected with the question of the nature of species, or with the problem of the origin of the various animals which we group together under the name of species. Thus the definition of the species becomes important. It is well known that this definition was given by Linne, who, in his famous Systema Natures (1735), was the first to classify and name the various groups of animals and plants, and drew up an orderly scheme of the species then known. Since that time "species" has been the most important and indispensable idea in descriptive natural history, in zoological and botanical classification ; although there have been endless controversies as to its real meaning. What, then, is this "organic species"? Linne himself did not give a very clear account of it. He unfortunately relied on religious notions which the dominant creed had founded on the Mosaic story of creation, and which have not vet wholly disappeared. Linne, in fact, appealed directly to the Mosaic narrative; he believed that, as it is stated in Genesis, one pair of each species of animals and plants was created in the beginning, and that all the individuals of each species are the descendants of these created couples. As for the hermaphrodites (organisms that have male and female organs in one being), he thought it sufficed to assume the creation of one sole individual, since this would be fully competent to propagate its species. Further developing these mystic ideas, Linne went on to borrow from Genesis the account of the deluge and of Noah's ark as a ground for the chorology of organisms — that is to say, for a science of their geographical and topographical distribution. He accepted the story that all the plants, animals, and men on the earth were swept away in a universal deluge, except the couples preserved with Noah in the ark, and ultimately landed on Mount Ararat. This mountain seemed to Linne particularly suitable for the landing, as it reaches a height of more than 16,000 feet, and thus provides in its higher zones the several climates demanded by the various species of animals and plants : the animals that were accustomed to a cold climate could remain at the summit ; those used to a warm climate could descend to the foot ; and those requiring a temperate climate could remain half-way down. From this point the re-population of the earth with animals and plants could proceed. It was impossible to have any scientific notion of the method of evolution in Linne's time, as one of the chief sources of information, paleontologv, was still wholly unknown. This science of the fossil remains of extinct animals and plants is very closely bound up with the whole question of evolution. It is impossible to explain the origin of living organisms without appealing to it. But this science did not rise until a much later date. The real founder of scientific paleontology was Georges Cuvier, the most distinguished zoologist who, after Linne, worked at the classification of the animal world, and effected a complete revolution in systematic zoology at the beginning of the nineteenth century. The influence of this famous scientist, which was of extraordinary service, especially in the first three decades of the century, was so great that he opened up new paths in nearly every part of scientific zoology, particularly in classification, comparative anatomy, and paleontology. It is important, therefore, to inquire what idea Cuvier had of the nature of the species. In this respect he associated himself with Linne and the Mosaic story of creation, though this was more difficult for him with his acquaintance with THE OLDER PHYLOGENY 63 fossil remains. He clearly showed that a number of quite different animal populations have lived on the earth ; and he claimed that we must distinguish a number of stages in the history of our planet, each of which was characterised by a special population of animals and plants. Cuvier had, naturally, to meet the question of the origin of these different populations, and if they were connected with each other or not. He answered this question in the negative, affirming that the successive populations were quite independent of each other, and that therefore the supernatural creative act, which was demanded as the origin of the animals and plants by the dominant creed, must have been repeated several times. In this way a whole series of different creative periods must have succeeded each other ; and in connection with these he had to assume that stupendous revolutions or cataclysms — something like the legendary deluge — must have taken place repeatedly. Cuvier was all the more interested in these catastrophes or cataclysms as geology was just beginning to assert itself, and great progress was being made in our knowledge of the structure and formation of the earth's crust. The various strata of the crust were being carefully examined, especially by the famous geologist Werner and his school, and the fossils found in them were being classified ; and these researches also seemed to point to a variety of creative periods. In each period the earth's crust, composed of the various strata, seemed to be differently constituted, just like the population of animals and plants that then lived on it. Cuvier combined this notion with the results of his own paleontological and zoological research; and in his effort to get a consistent view o( the whole process of the earth's history he came to form the theory which is known as "the catastrophic theory," or the theory ot terrestrial revolutions. According to this theory, there have been a series of mighty cataclysms on the earth, and these have suddenly destroyed the whole animal and plant population then living on it ; after each cataclysm there was a fresh creation o\ living things throughout the earth. As this creation could not be explained by natural laws, it was necessary to appeal to an intervention on the part of the Creator. This catastrophic theory, which Cuvier described in a special work, was soon generally accepted, and retained its position in biology for half a century. However, Cuvier's theory was completely overthrown sixty years ago by the geologists, led by Charles Lyell, the most distinguished worker in this field of science. Lyell proved in his famous Principles of Geology (1830) that the theory was false, in so far as it concerned the crust of the earth; that it was totally unnecessary to bring in supernatural agencies or general catastrophes in order to explain the structure and formation of the mountains; and that we can explain them by the familiar agencies which are at work to-day in altering and reconstructing the surface of the earth. These causes are — the action of the atmosphere and water in its various forms (snow, ice, fog, rain, the wear of the river, and the stormy ocean), and the volcanic action which is exerted by the glowing central mass. Lyell convincingly proved that these natural causes are quite adequate to explain every feature in the build and formation of the crust. Hence Cuvier's theory of cataclysms was very soon driven out of the province ot geology. Nevertheless, the theory remained for another thirty years in undisputed authority in biology. All the zoologists and botanists who gave any thought to the question of the origin of organisms adhered to Cuvier's erroneous idea of revolutions and new creations. It is one of the most curious instances on record of two cognate sciences pursuing for some time totally different ways from each other. Biology lagged behind on the paths of dualism, and declared it impossible to solve the problem of the formation of species on natural principles; geology, on the contrary, advanced rapidly along the monistic path, and solved the problem by the indication of the natural agencies at work. In order to illustrate the complete stagnancy of biology from 1830 to 1859, on the question of the origin of organisms, or the formation of the various species of animals and plants, I may say, from my own experience, that during the whole of my university studies I never heard a single word said about this most important problem o( the science. I was fortunate enough at that time (1852 [857) to have the most distinguished masters for every branch o( biological science. Not one o( them ever mentioned this question o( the origin o( speeies. Not a word was ever said about the earlier efforts to understand the formation of living things, nor about Lamarck's Philosophic Zoologique which had made a fresh attack on the problem in 1S09. Hence it is easy to understand the enormous opposition that Darwin encountered when he took up the question for the first lime. His views seemed to float in the air, without a single previous effort to support them. The whole question o( the formation of living things was considered by biologists, until 1859, as pertaining to the province of religion and transcendentalism; even in speculative philosophy, in which the question had been approached from various sides, no one had ventured to give it serious treatment. This last circumstance was due to the dualistic system of Immanuel Kant, and the enormous influence of this most important of recent thinkers down to our own time. Kant, a genius both in science and philosophy, taught a natural system oi evolution as far as the inorganic world was concerned ; but, on the whole, adopted a supernaturalist system as regards the origin of living things. In his Genera/ History ami Theory of flic Heavens [translated in Kant's Cosmogony] Kant made a very happy effort to deal with the structure and mechanical origin o\ the universe on Newton's principles — in other words, to explain it on mechanical and monistic principles; and this effort to explain the origin o( the universe by natural, efficient causes is still the basis of cosmogony. But Kant affirmed that this "principle o\ natural mechanicism, without which there can be no real science," was quite incapable o( furnishing an explanation o( organic phenomena, and especially of the origin o( living things; and that we must turn to supernatural or final causes for the explanation of the origin o\ these designed structures. He even went so far as to say: " It is quite certain that we cannot even satisfactorily understand, much less explain, the nature of an organism and its internal forces on purelv mechanical principles ; it is so certain, indeed, that we may confidently say: ' It is absurd for a man to imagine even that some dav a Newton will arise who will explain the origin of a single blade of grass by natural laws not controlled by design' — such a hope is entirely forbidden us." In these words Kant definitely adopts the dualistic and teleological point of view for biological science.1 Nevertheless, Kant deserted this point of view at times, particularly in several remarkable passages which I have dealt with at length in my Natural History of Creation (chap, v.), where he expresses himself in the opposite, or monistic, sense. In fact, these passages would justify one, as I showed, in claiming his support for the theory of evolution. Several very significant passages which Fritz Schultze has brought to light in his interesting work, Kant unit Darwin, seem to give Kant the character of being the first Darwinian prophet. He quite clearly enunciates the great idea of an all-embracing and monistic evolution. He speaks of "a falling away from the primitive type of the genus by natural variations." In fact, he affirms that " man originally walked on four legs, and only gradually developed the erect attitude, and raised himself so proudly above his former animal comrades." However, these monistic passages are only stray gleams of light; as a rule, Kant adheres in biology to the obscure dualistic ideas, according to which the forces at work in inorganic nature are quite different from those of the organic world. This dualistic system prevails in academic philosophy to-day — most of our philosophers still regarding these two provinces as totally distinct. They put, on the one side, the inorganic or "lifeless" world, in which there are at work only mechanical laws, acting necessarily and without design; and, on the other, the province of organic nature, in which none of the phenomena can be properly understood, purposive causes. The prevalence of this unfortunate dualistic prejudice prevented the problem o\ the origin o( species, and the connected question of the origin of man, from being regarded by the bulk of people as a scientific question at all until [859. Nevertheless, a few distinguished students, free from the current prejudice, be^an, at the commencement Of the nineteenth century, to make a serious attack on the problem. The merit of this attaches particularly to what is known as " the older school of natural philosophy," which has been so much misrepresented, and which included Jean Lamarck, Buffon, Geoffroy St. Hilaire, and Blainville in France; Wolfgang Goethe, Reinhold Treviranus, Schelling, and Lorentz Oken in Germany [and Erasmus Darwin in England]. The gifted natural philosopher who treated this difficult question with the greatest sagacity and comprehensiveness was Jean Lamarck. He was born at Bazentin, in Picardv, on August 1st, 1744; he was the son of a clergyman, and was destined for the Church. But he turned to seek glory in the army. In his sixteenth year he distinguished dimself by his bravery in the battle of Lippstadt, and was then in garrison in the south o\ France for several years. Here he be^an to study the interesting flora of the Mediterranean coast, and it inspired him with a love of botany. He resigned his commission, and in 1 778 published his important work, Flore Francaisc. for a long time he tailed to secure a place in science, and it was not until his fiftieth year ( 1 7<)4) that he was offered the chair of zoology at the museum o\ the Jardin des Plantes at Paris. He then went deeper into zoology, and he soon rendered as great a service in zoological classification as he had done in botany. In iSoj he published his Considerations sur les corps vivants, in which we find the i^erms o\ his theory o\ evolution. In 1809 appeared his chief work, the famous Philosophic Zoohgiqtte, in which he developed his theory. In [815 he published his comprehensive natural history o\ the vertebrates ( llistoirc naturelle des animaux sans vertebres), in the introduction to which his theory is again touched upon. About this time he became totally blind. Fortune, in her jealousy, never favoured him. While his fortunate rival, Cuvier, rose to the highest point of scientific fame and prestige at Paris, the great Lamarck — far greater than Cuvier in the vastness of his speculations and his conception of Nature — had to struggle in solitude for the necessities of life. His laborious life ended, in circumstances of great poverty, in 1829. Lamarck's PhUosophie Zoologiquc1 was the first scientific attempt to sketch the real course of the origin of species, the first " natural history of creation " of plants, animals, and men. But, as in the case of Wolff's book, this remarkably able work had no influence whatever ; neither one nor the other could obtain any recognition from their prejudiced contemporaries. No man of science was stimulated to take an interest in the work, and to develop the germs it contained of the most important biological truths. The most distinguished botanists and zoologists entirely rejected it, and did not even deign to reply to it. Cuvier, who lived and worked in the same city, has not thought lit to devote a single syllable to this great achievement in his memoir on progress in the sciences, in which the pettiest observations found a place. In short, Lamarck's Phi/osofihie Zoologique shared the fate of Wolff's theory of development, and was for half a century ignored and neglected. The German scientists, especially Oken and Goethe, who were occupied with similar speculations at the same time, seem ft) have known nothing about Lamarck's work. If they had known it, they would have been greatly helped by it, and might have carried the theory of evolution much farther than they found it possible to do. To give an idea of the great importance of the Philosophic Zoologique, I will briefly explain Lamarck's leading thought. He held that there was no essential difference between living and lifeless beings. Nature is one united and connected system of phenomena ; and the forces which fashion the lifeless bodies arc the only ones at work in the kingdom of living things. We have, therefore) to use the same method of investigation and explanation in both provinces. Life is only a physical phenomenon. All the plants and animals, with man at their head, are to be explained, in structure and life, by mechanical or efficient causes, without any appeal to final causes, just as in the case of minerals and other inorganic bodies. This applies equally to the origin of the various species. We must not assume any original creation, or repeated creations (as in Cuvier's theory), to explain this, but a natural, continuous, and necessary evolution. The whole evolutionary process has been uninterrupted. All the different kinds of animals and plants which we see to-day, or that have ever lived, have descended in a natural way from earlier and different species ; all come from one common stock, or from a few common ancestors. These remote ancestors must have been quite simple organisms of the lowest type, arising by spontaneous generation from inorganic matter. The succeeding species have been constantly modified by adaptation to their varying environment (especially by use and habit), and have transmitted their modifications to their successors by heredity. These are the chief outlines of Lamarck's theory, which we now call the theory of descent or " transformism," and which was unrecognised till Darwin took it up and gave it fresh support fifty years later. Lamarck is the real founder of the theory of evolution, and it is incorrect to speak of Darwin as its first champion. Lamarck was the first to formulate as a scientific theory the natural origin of living things, including man, and to push the theory to its extreme conclusions the rise of the earliest organisms by spontaneous generation (or abiogenesis) and the descent of man from the nearest related mammal, the ape. Lamarck sought to explain this last point, which is ol especial interest to us here, by the same agencies which he found at work in the natural origin of the plant and animal species. He considered use and habit (adaptation) on the One hand, and heredity on the other, to be the chief of these agencies. The most important modifications of the organs of plants and animals are due, in his opinion, to the function of these very organs, or to the use or disuse of them. To give a few examples, the woodpecker and the humming-bird have got their peculiarly long tongues from the habit of extracting their food with their tongues from deep and narrow folds or canals ; the frog has developed the web between his toes by his own swimming ; the giraffe has lengthened his neck by stretching up to the higher branches of trees, and so on. It is quite certain that this use or disuse of organs is a most important factor in organic development, but it is not sufficient to explain the origin of species. To adaptation we must add heredity as the second and not less important agency, as Lamarck perfectly recognised. He said that the modification of the organs in any one individual by use or disuse was slight, but that it was increased by accumulation in passing by heredity from generation to generation. But he missed altogether the principle which Darwin afterwards found to be the chief factor in the theory of transformation — namely, the principle of natural selection in the struggle for existence. It was partly owing to his failure to detect this supremely important element, and partly to the poor condition of all biological science at the time, that Lamarck did not succeed in establishing more firmly his theory of the common descent of man and the other animals. Lamarck tried to explain the descent of man from the ape chiefly by advance in the habits of the ape, and by a progressive development and use of its organs and the transmission to posterity of the modifications thus produced. He considered the most important of these improvements to be man's erect attitude, the modification of the hands and feet, and the acquisition of speech and accompanying development of the brain. He believed that the man-like apes, which were man's ancestors, had taken the first step towards humanity when they ceased to climb trees and began to walk erect. This led to the distinctive human carriage, the modification of the vertebral column and the pelvis, and the differentiation of the upper and lower limbs : the upper limbs became hands, and were used for grasping and touching things, while the lower were confined to locomotive purposes, and became feet pure and simple. As a result of this complete change of habits, and in virtue of the correlation of the various organs and their functions, a number of other modifications were caused. Thus the change in diet led to a modification of the jaws and teeth, and therefore of the whole face. The tail was no longer of any use, and it gradually disappeared. And as these apes lived in troops and had regular family relations (as is the case to-dav with the higher apes), the gregarious or social instincts were strongly developed. The simple sound-speech of the ape grew into the articulate speech of the man ; abstract ideas were formed from the groups of concrete impressions. Thus step by step the brain advanced, and with it the larynx — the organ of mind simultaneously with the organ of speech. In these most interesting speculations of Lamarck we have the germs of a sound theory of the evolution of man. (Cf. Packard). Independentlv of Lamarck, the older German school of natural philosophv, especially Reinhold Treviranus, in his Biologic (1802), and Lorentz Oken, in his NaturphUosophie (1809), turned its attention to the problem of evolution about the end of the eighteenth and beginning of the nineteenth century. I have described its work in my Natural History of Creation (chap. iv.). Here I can only deal with the brilliant genius whose evolutionary ideas are of special interest — the greatest of German poets, Wolfgang Goethe. With his keen eye for the beauties of nature, and his profound insight into its life, Goethe was early attracted to the study of various natural sciences. It was the favourite occupation of his leisure hours throughout life. He gave particular and protracted attention to the theory of colours. But the most valuable of his scientific studies are those which relate to that "living, glorious, precious thing," the organism. lie made profound research into the science of structures or morphology (morphae forms). Here, with the aid of comparative anatomy, he obtained the most brilliant results, and went far in advance of his time. I may mention, in particular, his vertebral theory of the skull, his discovery of the pineal gland in man, his system of the metamorphosis of plants, etc. These morphological studies led Goethe on to research into the formation and modification of organic structures which we must count as the first germ of the science of evolution. He approaches so near to the theory of descent that we must regard him, after Lamarck, as one of its earliest founders. It is true that he never formulated a complete scientific theory of evolution, but we find a number of remarkable suggestions of it in his splendid miscellaneous essays on morphology. Some of them are really among the very basic ideas of the science of evolution. I will quote here only one or two of the most remarkable passages : " We have got far enough, then, to say confidently that all the higher organic natures, in which we include the fishes, amphibia, birds, and mammals, with man at their head, are made after one primitive type, and this only oscillates a little to one side or other of its steady features, and daily advances and is modified by reproduction" (1796). This "primitive type," on which even man is modelled, corresponds to our common ancestral form of the vertebrate stem, from which all the different species of vertebrates have arisen by " incessant formation, modification, and reproduction." In another place Goethe says (1807) : "When we compare plants and animals in their most rudimentary forms, it is almost impossible to distinguish between them. But we may say that the plants and animals, beginning with an almost inseparable closeness, gradually advance along two divergent lines, until the plant at last grows in the solid, enduring tree and the animal attains in man to the highest degree of mobility and freedom." That Goethe was not merely speaking in a poetical, but in a literal genealogical, sense of this close affinity of organic forms is clear from other remarkable passages in which he treats of their variety in outward form and unity in internal structure. He believes that every living thing has arisen by the interaction of two opposing formative forces or impulses. The internal or "centripetal " force, the type or " impulse to specification," seeks to maintain the constancy of the specific forms in the succession of generations: this is heredity. The external or " centrifugal " force, the element of variation or " impulse to metamorphosis," is continually modifying the specie^ by changing their environment : this is adaptation. In these significant conceptions Goethe approaches very close to a recognition of the two great mechanical factors which we now assign as the chief causes of the formation of species. However, in order to appreciate Goethe's views on morphology, one must associate his decidedly monistic conception of nature with his pantheistic philosophy. The warm and keen interest with which he followed, in his last years, the controversies of contemporary French scientists, and especially the struggle between Cuvi^er and Geoffrey St. Ililaire (see chap. iv. of The Natural History of Creation), is very characteristic. It is also necessary to be familiar with his style and general tenour of thought in order to appreciate rightly the many allusions to evolution found in his writings. Otherw ise, one is apt to make serious errors. In a lecture that I delivered in [882 at the Congress of German scientists and medical men at Eisenach I made a rather full comparison of the scientific ideas of Darwin, Goethe, and Lamarck, and showed their important bearing on the pantheistic philosophv. In my opinion, these three greatest figures in modern thought stand on the common ground of Monism, or the system which teaches the unity of the universe on scientific grounds. All held the belief in the unity of God and Xature which was defended by Giordano Bruno and Spinoza, and which Goethe expressed so nobly in his writings on God and the World. We can understand, therefore, the lively interest which Goethe maintained till his last days in the highest questions of biology. The passages which I have quoted on the title-pages of the chapters in my GenereUe Morphologie show how firm a grasp he had ot the intimate genetic relation of all organic forms. Me approached so close, at the end of the eighteenth century, to the principles of the science of evolution that he may well be described as the first forerunner of Darwin, although he did not go so far as to formulate evolution as a scientific system, as Lamarck did. This simple idea is the central thought of Darwinism, or the theory of selection. Darwin conceived this idea at an early date, and then, for more than twenty years, worked at the collection of empirical evidence in support of it before he published his theory. I have described the chief features of his method, his life, and his writings in my Natural History of Creation. The ample biography, in three volumes, published by his son, Francis Darwin, in 1S87, gives full information about him. Here 1 will only refer to some of the salient points. Charles Darwin was born on February 12th, 1S09, at Shrewsbury, where his father, Robert Darwin, had a medical practice. Mis grandfather, Erasmus Darwin, was an able scientist of the older school of natural philosophv, who published a number of natural-philosophic works about the end of the eighteenth century. The most important of them is his Zoonomta, published in 1704, in which he expounds views similar to those of Goethe and Lamarck, without, however, knowing anything of the work of these contemporaries. By the law of latent heredity, or "atavism," Erasmus Darwin transmitted a part of his ability to his grandson Charles, though no trace of it is found in his son Robert. This is a very interesting case of atavism, a process which Charles Darwin himself treated so admirably. However, in the writings of the grandfather the plastic imagination rather outran the judgment, while in Charles Darwin the two were better balanced. As many narrow-minded scientists of our own day regard the imagination as superfluous in biology, and think their lack of it a great advantage in the way of " exactness," it is interesting to call attention to a striking saying of a gifted man of science who was himself one of the founders of the "exact" or strictly empirical school. Johannes Miiller, the German Cuvier, whose works will ever remain a model of accurate research, declared that a constant interaction and harmonious adjustment of the imagination and discoveries. Charles Darwin was fortunate enough to take part in a scientific expedition at the close of his university career in his twenty-second year. This lasted five years, and greatly stimulated him and enriched his fund of knowledge. At the very beginning of it, as soon as he landed in America, he was attracted by a number of phenomena which suggested the chief problem of his life — the question of the origin of species. The instructive facts of the geographical distribution of species, on the one hand, and the relation of living to dead species of the same locality on the other, prompted him to surmise that closely-related species must have descended from a common stem form. Then, at the close of his voyage, when he devoted himself for a year with great vigour to the systematic study of domestic animals and garden plants, he noticed the obvious analogies in structures between them and the corresponding species in the wild state. But he did not come to conceive the chief point of his theory, natural selection through the struggle for life, until he read Malthus's famous Essay on Population. He then saw clearly the analogy between the relations of population and over-population in civilised communities and the mutual relations of animals and plants in a natural state. For many years he collected material to give a massive support to his theory. At the same time, he made a number of experiments himself in artificial selection, and gave special attention to the action of selection on tame pigeons. The quietness of his life on his estate at Down, near Beckenham, gave him requisite leisure. He died there on April 19th, 18S2, working assiduously until death at the establishment of his epoch-making theory by new discoveries. Darwin did not publish any account of his theory until 1858, when Alfred Russel Wallace, who had independently reached the same theory of selection, published his own work. In the following year appeared the Origin of Species, in which he developes it at length and supports it with a mass of proof. As I have given my opinion on it fully in my Generelle Morphologic and Natural History of Creation, I need not stay to do so here, and will only add a word on the essence oi the Darwinian theory, on the understanding of which all the rest depends. This is the simple prineiple that the stru^le for lite modifies living things in the natural condition, and produces new species, through the same agencies which man employs in artificially forming new varieties of animals and plants. These agencies virtually exercise a selection among the individuals brought into existence, heredity and adaptation acting together throughout as the chief plastic forces." Darwin's younger contemporary, Alfred Russel Wallace, the famous traveller, had reached the same conclusion. But he had not so clear a perception as Darwin of the effectiveness of natural selection in forming species, and did not develop the theory so fully. Nevertheless, Wallace's writings, especially those on mimicry, etc., and an admirable work on The Geographical Distribution of Animals, contain many fine original contributions to the theory of selection. Unfortunately, this gifted scientist has since devoted himself to spiritism. Darwin's Origin of Species had an extraordinary influence, though not at first on the experts of the science. It took zoologists and botanists several years to recover from the astonishment into which they had been thrown through the revolutionary idea of the work. But its influence on the special sciences with which we zoologists and botanists arc concerned has increased from year to year; it has introduced a most healthy fermentation in every branch of biology, especially in comparative anatomy and ontogeny, and in zoological and botanical classification. In this way it has brought about almost a revolution in the prevailing views. However, the point which chiefly concerns us here — the extension of the theory to man — was not touched at all in Darwin's first work in 1859. It was believed for several years that he had no thought of applying his principles to man, THE MODERX SCIENCE OF EVOLVTIOX but that he shared the current idea of man holding a special position in the universe. Not only ignorant laymen (especially several theologians), but also a number of men of science, said very naively that Darwinism in itself was not to be opposed ; that it was quite right to use it to explain the origin of the various species of plants and animals, but that it was totally inapplicable to man. In the meantime, however, it seemed to a good many thoughtful people, laymen as well as scientists, that this was wrong; that the descent of man from some other animal species, and immediately from some ape-like mammal, followed logically and necessarily from Darwin's reformed theory of evolution. Many of the acuter opponents of the theory saw at once the justice of this position, and, as this consequence was intolerable, they wanted to get rid of the whole theory. The first scientific application of the Darwinian theory to man was made by Huxley, the greatest zoologist in England. This able and learned scientist, to whom zoology owes much of its progress, published in 1S63 a small work entitled Evidence as to Man's Place in Mature. In the extremely important and interesting lectures which made up this work he proved clearly that the descent of man from the ape followed necessarily from the theory of descent. If that theory is true, we are bound to conceive the animals which most closely resemble man as those from which humanity has been gradually evolved. About the same time Carl Vogt published a larger work on the same subject — Vorlesungen iiber den menschen seine Stellung in der Schcpjung and in der Geschichte der Erde. We must also mention Gustav Jaeger and Friedrich Rolle among the zoologists who accepted and taught the theory of evolution immediately after the publication of Darwin's book, and maintained that the descent of man from the lower animals logically followed from it. The latter published, in 1866, a work on the origin and position of man. theory of evolution to the whole organic kingdom, including man.1 I endeavoured to sketch the probable ancestral trees of the various classes of the animal world, the protists, and the plants, as it seemed necessary to do on Darwinian principles, and as we can actually do now with a high degree of confidence. If the theory of descent which Lamarck first clearly formulated and Darwin thoroughly established is true, we seem to be able to draw up a natural classification of plants and animals in the light of their genealogy, and to conceive the large and small divisions of the system as the branches and twigs of an ancestral tree. The eight genealogical tables which I inserted in the second volume of the Generelle Morphologie are the first sketches of their kind. In the twenty-seventh chapter, particularly, I trace the chief stages in man's ancestry, as far as it is possible to follow it through the vertebrate stem. I tried especially to determine, as well as one could at that time, the position of man in the classification of the mammals and its genealogical significance. I have greatly improved this attempt, and treated it in a more popular form, in chaps, xxvi.-xxviii. of ray Natural History of Creation (1868).2 It was not until 1871, twelve years after the appearance of The Origin of Species, that Darwin published the famous work which made the much-contested application of his theory to man, and crowned the splendid structure of his system. This important work was The Descent of Man, and Selection in Relation to Sex. In this Darwin expressly drew the conclusion, with rigorous logic, that man also must have been developed out of lower species, and described the important part played by sexual selection in the elevation of man and the other higher animals. He showed that the careful selection which the sexes exercise on each other in regard to sexual relations and procreation, and the aesthetic feeling which the higher animals develop through this, are of the utmost importance in the progressive development of forms and the differentiation of the sexes. The males choosing the handsomest females in one class of animals, and the females choosing only the finest-looking males in another, the special features and the sexual characteristics are increasingly accentuated. In fact, some of the higher animals develop in this connection a finer taste and less prejudiced judgment than man himself. But, even as regards man, it is to this sexual selection that we owe the family-life, which is the chief foundation of civilisation. The rise of the human race is due for the most part to the advanced sexual selection which our ancestors exercised in choosing their mates. (Cf. the eleventh chapter of the Natural History of Creation and the second volume of the Generelle Morphologic.) Darwin accepted in the main the general outlines of man's ancestral tree, as I gave it in the Generelle Morphologie and the Natural History of Creation, and admitted that his studies led him to the same conclusion. That he did not at once apply the theory to man in his first work was a commendable piece of discretion ; such a sequel was bound to excite the strongest opposition to the whole theory. The first thing to do was to establish it as regards the animal and plant worlds. The subsequent extension to man was bound to be made sooner or later. It is important to understand this very clearly. If all living things come from a common root, man must be included in the general scheme of evolution. On the other hand, if the various species were separately created, man, too, must have been created, and not evolved. We have to choose between these two alternatives. This cannot be too frequently or too strongly emphasised. Either all the species of animals and plants are of supernatural origin — created, not evolved — and in that case man also is the outcome of a creative act, as religion teaches; or the different species have been evolved from a few common, simple ancestral forms, and in that case man is the highest fruit of the tree of evolution. descent of man from the lower animals is a special deduction which inevitably follows from the general inductive lam of the whole theory of evolution. In this principle we have a clear and plain statement of the matter. Evolution is in reality nothing but a great induction, which we are compelled to make by the comparative study of the most important facts of morphology and physiology. But we must draw our conclusion according to the laws of induction, and not attempt to determine scientific truths by direct measurement and mathematical calculation. In the study of living things we can scarcely ever directly and fully, and with mathematical accuracy, determine the nature of phenomena, as is done in the simpler study of the inorganic world — in chemistry, physics, mineralogy, and astronomy. In the latter, especially, we can always use the simplest and absolutely safest method — that of mathematical determination. But in biology this is quite impossible for various reasons ; one very obvious reason being that most o( the facts of the science are very complicated and much too intricate to allow a direct mathematical analysis. The greater part of the phenomena that biology deals with are complicated historical processes, which are related to a far-reaching past, and as a rule can only be approximate!}' estimated. Hence we have to proceed by induction — that is to say, to draw general conclusions, stage by Stage, and with proportionate confidence, from the accumulation of detailed observations. These inductive conclusions cannot command absolute confidence, like mathematical axioms; but they approach the truth, and gain increasing probability, in proportion as we extend the basis ot observed facts on which we build. The importance of these inductive laws is not diminished from the circumstance that they are looked upon merely as temporary acquisitions of science, and may be improved to any extent in the progress of scientific knowledge. The same may be said of the attainments o( many other sciences, such as geology or archeology. 1 lowever much they may be altered and improved in detail in the course of time, these inductive truths may retain their substance unchanged. Now, when we say that the theory of evolution in the sense of Lamarck and Darwin is an inductive law — -in fact, the greatest of all biological inductions — we rely, in the first place, on the facts of paleontology. This science gives us some direct acquaintance with the historical phenomena of the changes of species. From the situations in which we find the fossils in the various strata of the earth we gather confidently, in the first place, that the living population of the earth has been gradually developed, as clearly as the earth's crust itself; and that, in the second place, several different populations have succeeded each other in the various geological periods. Modern geology teaches that the formation of the earth has been gradual, and unbroken by any violent revolutions. And when we compare together the various kinds of animals and plants which succeed each other in the history of our planet, we find, in the first place, a constant and gradual increase in the number of species from the earliest times until the present day; and, in the second place, we notice that the forms in each great group of animals and plants also constantly improve as the ages advance. Thus, of the vertebrates there are at first only the lower fishes ; then come the higher fishes, and later the amphibia. Still later appear the three higher classes of vertebrates — the reptiles, birds, and mammals, for the first time; only the lowest and least perfect forms of the mammals are found at first; and it is only at a very late period that placental mammals appear, and man belongs to the latest and youngest branch of these. Thus perfection of form increases as well as variety from the earliest to the latest stage. That is a fact of the greatest importance. It can only be explained by the theory of evolution, with which it is in perfect harmony. If the different groups of plants and animals do really descend from each other, we must expect to find this increase in their number and perfection under the influence of natural selection, just as the succession of fossils actually discloses it to us. Comparative anatomy furnishes a second series of facts which are of great importance for the forming of our inductive law. This branch of morphology compares the adult Structures of living things, and seeks in the great variety of organic forms the stable and simple law of organisation, or the common type or structure. Since Cuvier founded this science at the beginning of the nineteenth century it has been a favourite study of the most distinguished scientists. Even before Cuvier's time Goethe had been greatly stimulated by it, and induced to take up the study of morphology. Comparative osteology, or the philosophic study and comparison of the bony skeleton of the vertebrates — one of its most interesting sections — especially fascinated him, and led him to form the theory of the skull which I mentioned before. Comparative anatomy shows that the internal structure of the animals of each stem and the plants of each class is the same in its essential features, however much they differ in external appearance. Thus man has so great a resemblance in the chief features of his internal organisation to the other mammals that no comparative anatomist has ever doubted that he belongs to this class. The whole internal structure of the human body, the arrangement of his various systems of organs, the distribution of the bones, muscles, blood-vessels, etc., and the whole structure of these organs in the larger and the finer scale, agree so closely with those of the other mammals (such as the apes, rodents, ungulates, cetacea, marsupials, etc.) that their external differences are of no account whatever. We learn further from comparative anatomy that the chief features of animal structure are so similar in the various classes (fifty to sixty in number altogether) that they may all be comprised in from eight to twelve great groups. But even in these groups, the stemforms or animal types, certain organs (especially the alimentary canal) can be proved to have been originally the same for all. We can only explain by the theory of evolution this essential unity in internal structure of all these animal forms that differ so much in outward appearance. This wonderful fact can only be really understood and explained when \\lregard the internal resemblance as an inheritance from common-stem forms, and the external differences as the effect of adaptation to different environments. In recognising this, comparative anatomy has itself advanced to a higher stage. Gegenbaur, the most distinguished of living students of this science, says that with the theory of evolution a new period began in comparative anatomy, and that the theory in turn found a touchstone in the science. " Up to now there is no fact in comparative anatomy that is inconsistent with the theory of evolution ; indeed, they all lead to it. In this way the theory receives back from the science all the service it rendered to its method." Until then students had marvelled at the wonderful resemblance of living things in their inner structure without being able to explain it. We are now in a position to explain the causes of this, by showing that this remarkable agreement is the necessary consequence of the inheriting of common stem-forms ; while the striking difference in outward appearance is a result of adaptation to changes of environment. Heredity and adaptation alone furnish the true explanation. But one special part of comparative anatomy is of supreme interest and of the utmost philosophic importance in this connection. This is the science of rudimentary or useless organs ; I have given it the name of " dysteleology " in view of its philosophic consequences. Nearly every organism (apart from the very lowest), and especially every highlydeveloped animal or plant, including man, has one or more organs which are of no use to the body itself, and have no share in its functions or vital aims. Thus we all have, in various parts of our frame, muscles which we never use, as, for instance, in the shell of the ear and adjoining parts. In most of the mammals, especially those with pointed ears, these internal and external ear-muscles are of great service in altering the shell of the ear, so as to catch the waves of sound as much as possible. But in the case of man and other short-eared mammals these muscles are useless, though they are still present. Our ancestors having long abandoned the use of them, we cannot work them at all to-day. In the inner corner of the eye we have a small crescent-shaped fold of skin ; this is the last relic of a third inner eye-lid, called the nictitating (winking) membrane. This membrane is highly developed and o( great service in some of our distant relations, such as fishes of the shark type and several other vertebrates; in us it is shrunken and useless. In the intestines we have a process that is not only quite useless, but may be very harmful — the vermiform appendix. This small intestinal appendage is often the cause of a fatal illness. If a cherry-stone or other hard body is unfortunately squeezed through its narrow aperture during digestion, a violent inflammation is set up, and often proves fatal. This appendix has no use whatever now in our frame ; it is a dangerous relic of an organ that was much larger and was of great service in our vegetarian ancestors. It is still large and important in many vegetarian animals, such as the apes and the ungulates. There are similar rudimentary organs in all parts of our body, and in all the higher animals. They are among the most interesting phenomena to which comparative anatomy introduces us ; partly because they furnish one of the clearest proofs of evolution, and partly because they most strikingly refute the teleology of certain philosophers. The theory of evolution enables us to give a very simple explanation of these phenomena. We have to look on them as organs which have fallen into disuse in the course of many generations. With the decrease in the use of its function, the organ itself shrivels up gradually, and finally disappears. There is no other way of explaining rudimentary organs. Hence they arc also of great interest in philosophy; they show clearly that the monistic or mechanical view o( the organism is the only correct one, and that the dualistic or teleological conception is wrong. The ancient legend of the direct creation of man according to a pre-conceived plan and the empty phrases about "design " in the organism are completely shattered by them. It would lie difficult to conceive a more thorough refutation of teleology than is furnished by the fact that all the higher animals have these rudimentary organs. the hollowness of the phrases about a " moral government of the world." No one but a learned idealist or a well-meaning optimist who shuts his eyes to facts can speak to-day of such a "moral order." There is, unfortunately, no more trace of it in nature than in human life — no more in natural history than in the history of civilisation. A grim and ceaseless struggle for life is the real mainspring of the purposeless drama of the world's history. We can only see a " moral order" and "design" in it when we ignore the triumph of immoral force and the aimless features of the organism. Might goes before right as long as organic life exists. The theory of evolution finds its broadest inductive foundation in the natural classification of living things, which arranges all the various forms in larger and smaller groups, according to their degree of affinity. These groupings or categories of classification — the varieties, species, genera, families, orders, classes, etc. — show such constant features of co-ordination and subordination that we are bound to look on them as genealogical, and represent the whole system in the form of a branching tree. This is the genealogical tree of the variously related groups; their likeness in form is the expression of a real affinity. As it is impossible to explain in any other way the natural tree-like form of the system of organisms, we must regard it at once as a weighty proof of the truth of evolution. The careful construction of these genealogical trees is, therefore, not an amusement, but the chief task of modern classification. Among the chief phenomena that bear witness to the inductive law of evolution we have the geographical distribution of the various species of animals and plants over the surface of the earth, and their topographical distribution on the summits of mountains and in the depths of the ocean. The scientific study of these features — the " science of distribution," or chorology (chora = a place) — has been pursued with lively interest since the discoveries made by Alexander von Humboldt. Until Darwin's time the work was confined to the determination of the facts of the science, and chiefly aimed at settling the spheres of distribution of the existing large and small groups of living things. It was impossible at that time to explain the causes of this remarkable distribution, or the reasons why one group is found only in one locality and another in a different place, and why there is this manifold distribution at all. Here, again, the theory of evolution has given us the solution of the problem. It furnishes the only possible explanation when it teaches that the various species and groups of species descend from common stem-forms, whose ever-branching offspring have gradually spread themselves by migration over the earth. For each group of species we must admit a " centre of production," or common home ; this is the original habitat in which the ancestral form was developed, and from which its descendants spread out in every direction. Several of these descendants became in their turn the stem-forms for new groups of species, and these also scattered themselves by active and passive migration, and so on. As each migrating organism found a different environment in its new home, and adapted itself to it, it was modified, and gave rise to new for ins. This very important branch of science that deals with active and passive migration was founded by Darwin, with the aid of the theory of evolution ; and at the same time he advanced the true explanation of the remarkable chorological relation of the living population in any locality to the fossil forms found in it. Moritz Wagner very ably developed his idea under the title of "the theory of migration." In my opinion, this famous traveller has rather over-estimated the value of his theory of migration when he takes it to be an indispensable condition of the formation of new species and opposes the theory of selection. The two theories are not opposed in their main features. Migration (by which the stem-form of a new species is isolated) is really only a special case of selection. The striking and interesting facts of chorology can only be explained by .the theory of evolution, and therefore we must count them among the most important of its inductive bases. which we perceive in the economy of the living organism. The many and various relations of plants and animals to each other and to their environment, which are treated in bionomy (the oecology or ethology of organisms, from nomas, law or norm, and bios, life), the interesting facts of parasitism, domesticity, care of the young, social habits, etc., can only be explained by the action of heredity and adaptation. Formerly people saw only the guidance of a beneficent Providence in these phenomena ; to-day we discover in them admirable proofs of the theory of evolution. It is impossible to understand them except in the light of this theory and the struggle for life. Finally, we must, in my opinion, count among the chief inductive bases of the theory of evolution the fcetal development of the individual organism, the whole science of embryology or ontogeny. But as the later chapters will deal with this in detail, I need say nothing further here. I shall endeavour in the following pages to show, step by step, how the whole of the embryonic phenomena form a massive chain of proof for the theory of evolution ; for they can be explained in no other way. In thus appealing to the close causal connection between ontogenesis and phylogenesis, and taking our stand throughout on the biogenetic law, we shall be able to prove, stage by stage, from the facts of embryology, the evolution of man from the lower animals. The general adoption of the theory of evolution has definitely closed the controversy as to the nature or definition of the species. This question had received a great variety of answers during the last century, but no satisfactory result had been reached. Thousands of botanists and zoologists were engaged daily in the classification and description of species, but they made no progress. Many hundreds of thousands of animal and plant groups were declared to be " real species," without the authors being able to give any proof or logical justification of their divisions. There were endless controversies between the classifiers as to whether the group in question was a true or false species, a species or a variety, a sub-species or a race, though they had never asked themselves the real meaning of these terms. If they had striven to be clear on this point, they would have seen long ago that the words have no absolute meaning whatever, but are only group-names, or categories of classification, with a purely relative value. In 1857, it is true, a famous and gifted, but inaccurate and dogmatic, scientist, Louis Agassiz, attempted to give an absolute value to these "categories of classification." He did this in his Essay on Classification, in which he turns upside down the phenomena of organic nature, and, instead of tracing them to their natural causes, examines them through a theological prism. The true species (bona species ) was, he said, an "incarnate idea of the Creator." Unfortunately, this pretty phrase has no more scientific value than all the other attempts to save the absolute or intrinsic value of the species. I believe I have shown this clearly enough in the exhaustive criticism of the morphological and physiological idea of the species and the categories of classification which I gave in my Generelle Morphologie (Band II., SS. 323402). Agassiz's "Creator" is an idealised man, an imaginative architect, who is ever planning and producing new species. (See also the third chapter of the Natural History of Creation.) The dogma of the fixitv and creation of species lost its last great champion when Agassiz died in 1S73. The opposite theory, that all the different species descend from common stem-forms, encounters no serious difficulty to-day. All the endless research into the nature of the species, and the possibility oi several species descending from a common ancestor, has been closed to-day by the removal of the sharp limits that had been set up between species and varieties on the one hand, and species and genera on the other. I gave an analytic proof o( this in my monograph on the sponges (1872), having made a very close study of variability in this small but highly instructive group, and shown the impossibility of making any dogmatic distinction of species. According as the classifier takes his ideas of genus, species, and variety in a broader or in a narrower sense, he will find in the small group of the sponges either one genus with three species, or» three genera with 238 species, or 113 genera with 59I species. Moreover, all these forms are so connected by intermediate forms that we can convincingly prove the descent of all the sponges from a common stem-form, the olynthus. Here, I think, I have given an analytic solution of the problem of the origin of species, and so met the demand of certain opponents of evolution for an actual instance of descent from a stem-form. Those who are not satisfied with the synthetic proofs of the theory of evolution which are provided by comparative anatomy, embryology, paleontology, dysteleology, chorology, and classification, may try to refute the analytic proof given in my treatise on the sponge, the outcome of five years of assiduous study. I repeat: It is now impossible to oppose evolution on the ground that we have no convincing example of the descent of all the species of a group from a common ancestor. The monograph on the sponges furnishes such a proof, and, in my opinion, an indisputable proof. Any man of science who will follow the protracted steps of my inquiry and test my assertions will find that in the case of the sponges we can follow the actual evolution of species, in static nascenti. And if this is so, if we can show the origin of all the species from a common form in one single class, we have the solution of the problem of man's origin, because we are in a position to prove clearly his descent from the lower animals. At the same time, we can now reply to the often-repeated assertion, even heard from scientists of our own day, that the descent of man from the lower animals, and proximately from the apes, still needs to be "proved with certainty." These " certain proofs " have been available for a longtime; one has only to open one's eyes to see them. It is a mistake to seek them in the discovery of intermediate forms between man and the ape, or the conversion of an ape into a human being by skilful education. The proofs lie in the great mass of empirical material we have already collected. They are furnished in the strongest form by the data of comparative anatomy and embryology, completed by paleontology. It is already have. It seems especially urgent to refer to-day to these various sources of phylogeny, and point out how they confirm each other, because the growth of specialism in every branch of biology and the enormous accumulation of fresh observations in detail have led to a certain amount of narrowness in appreciating them. Many modern embryologists occupy themselves with the application of their improved methods to the detailed study of minute sections of the embryo and the mechanical analysis of them, and fail to keep in view the entire organism and its important relations to others of the same stem, as shown in comparative anatomy and classification. Many of the misleading theories of this modern mechanical embryology would never have been formulated if their authors had been acquainted with the relevant facts of paleontology. On the other hand, however, most of the paleontologists are ignorant of the most important results of comparative embryology, and so fail to appreciate the value of the biogenetic law. However important it is to determine the facts of paleontology accurately, their evolutionary significance cannot be properly appraised without the aid of comparative anatomy and ontogeny. At the same time, workers in these latter sciences must never lose touch with the results of paleontology. Comparative anatomists will reach no satisfactory result if they seek to determine the homologies and affinities of animal forms merely by a comparison of living species, without any regard to their extinct ancestors. The distinguished New York paleontologist, Henry Osborn, has recently laid stress on the wisdom of basing the science of evolution on a comprehensive use of all the three sources of evidence. Our science requires these three supports as much as the stool needs its three legs. I was almost alone thirty-six years ago when I made the first attempt, in my Generellc Morpliologie, to put organic morphology on a mechanical foundation through Darwin's theory of descent. The association of ontogeny and phylogeny and the proof of the intimate causal connection between these two sections of the science of evolution, which I expounded in my work, met with the most spirited opposition on nearly all sides. The next ten years were a terrible "struggle for life" for the new theory. But for the last twenty-five years the tables have been turned. The phylogenetic method has met with so general a reception, and found so prolific a use in every branch of biology, that it seems superfluous to treat any further here of its validity and results. The proof of it lies in the whole morphological literature of the last three decades. But no other science has been so profoundly modified in its leading thoughts by this adoption, and been forced to yield such far-reaching consequences, as that science which I am now seeking to establish — monistic anthropogeny. This statement may seem to be rather audacious, since the very next branch of biology, anthropology in the stricter sense, makes very little use of these results of anthropogeny, and sometimes expressly opposes them. This applies especially to the attitude which has characterised the German Anthropological Society (the Deutsche Gesellschaftfiir Autliropologie) for some thirty years. Its powerful president, the famous pathologist, Rudolph Virchow, is chiefly responsible for this. Until his death (September 5th, 1902) he never ceased to reject the theory of descent as unproven, and to ridicule its chief consequence — the descent of man from a series of mammal ancestors — as a fantastic dream. I need only recall his well-known expression at the Anthropological Congress at Vienna in 1894, that " it would be just as well to say man came from the sheep or the elephant as from the ape." Virchow's assistant, the secretary of the German Anthropological Society, Professor Johannes Ranke of Munich, has also indefatigably opposed transformism : he has succeeded in writing a work in two volumes ( Der Mensch), in which all the facts relating to his organisation are explained in a sense hostile to evolution. This work has had a wide circulation, owing- to its admirable illustrations and its able treatment of the most interesting facts of anatomy and physiology — exclusive o( the sexual organs! But, as it has done a great deal to spread erroneous views among the general public, I have included a criticism o( it in mv Natural History of Creation, as well as met Virchow's attacks on anthropogeny. Neither Virchow, nor Ranke, nor any other "exact" anthropologist, has attempted to give any other natural explanation o( the origin of man. Thev have either set completely aside this "question of questions" as a transcendental problem, or they have appealed to religion for its solution. We have to show that this rejection of the rational explanation is totally without justification. The fund of knowledge which has accumulated in the progress of biology in the nineteenth century is quite adequate to furnish a rational explanation, and to establish the theory of the evolution ol man on the solid facts of his embryology. THE OVUM AND THE AMCEBA1 The ovum of man and other animals is a simple cell. The fully-developed man is an organised community of cells. Independent cells and tissuecells. Importance and chief features of the cell theory. Definition, form, and size of the cell. Consists of two parts : Nucleus (caryoplasm) and cell-body (cytosoma — cytoplasm). Active protoplasm and passive products of protoplasm. The cell as the elementary organism, or the unit-individual. Plastids, or constructive cells. Their vital phenomena. Vegetal functions (nutrition, reproduction). Animal functions (movement, sensation). The special features of the ovum. Yelk. Germinal vesicles. Germinal disc. Coverings of the ovum, ovolemma or chorion. Application of the biogenetic law to the ovum. Unicellular organisms. The amoeba. Structure and functions of the amoeba. Amoeboid movements. Amoeboid cells in the multicellular organism. Their movements and intussusception of ^olid matter. Blood-cells that eat. Comparison of the amoeba with the ovum. Amoeboid ova of the sponges and their movements. Evolutionary conclusion from the unicellular ovum to the unicellular ancestor. In order to understand clearly the course of human embryology, we must select the more important of its wonderful and manifold processes for fuller explanation, and then proceed from these to the innumerable features of less importance. The most important feature in this sense, and the best starting-point for ontogenetic study, is the fact that man is developed from an ovum, and that this ovum is a simple cell. The human ovum does not materially differ in form and composition from that of the other mammals, whereas there is a distinct difference between the fertilised ovum of the mammal and that of any other animal. This fact is so important that few should be unaware of its extreme significance ; yet it was quite unknown in the first quarter of the nineteenth century. As we have seen, the human and mammal ovum was not discovered until 1827, when Carl Ernst von Baer detected it. Up to that time the larger vesicles, in which the real and much smaller ovum is contained, had been wrongly regarded as ova. The important circumstance that this mammal ovum is a simple cell, like the ovum of other animals, could not, of course, be recognised until the cell theory was established. This was not done, by Schleiden for the plant and Schwann for the animal, until 1838. As we have seen, this cell theory is of the greatest service in explaining the human frame and its embryonic development. Hence we must say a few words about the actual condition of the theory and the significance of the \iews it has suggested. In order properly to appreciate the cellular theory, the most important element in our morphological and physiological science, it is necessary to understand in the first place that the cell is a unified organism, a self-contained living or unit. This common unit of structure is the cell. It does not matter whether we thus dissect a leaf, flower, or fruit, or a bone, muscle, gland, or bit of skin, etc.; we find in every case the same ultimate constituent, which has been called the cell since Schleiden's discovery. There are many opinions as to its real nature, but the essential point in our view of the cell is to look upon it as a self-contained or independent living unit. It is, in the words of Briicke, "an elementary organism," or, as Virchow puts it, "a vital focus," a "biomeron." We may define it most precisely as the ultimate organic unit, or "an individual of the first class"; and as the cells are the sole active principles in every vital function, we may call them the " plastids," or "formative elements" (cf. the Gen. Morph., Band I., S 269). This unity is found in both the anatomic structure and the physiological function. In the case of the protists, the entire organism usually consists of a single autonomous cell throughout life. But in the histonal (tissue-forming) animals and plants, which are the great majority, the organism begins its career as a simple cell, and then grows into a cell-community, or, more correctly, an organised cellstate. Our own body is not really the simple unity that it is generally supposed to be. On the contrary, it is a very elaborate social system of countless microscopic organisms, a colony or commonwealth, made up of innumerable independent units, or very different tissue-cells. In reality, the term "cell," which existed long before the cell theory was formulated, is not happily chosen. Schleiden, who first brought it into scientific use in the sense of the cell theory, gave this name to the elementary organisms because, when you find them in the dissected plant, they generally have the appearance of chambers, like the cells in a bee-hive, with firm walls and a fluid or pulpy content. This idea of a cell as a closed vesicle or little sac, with a fluid content and firm envelope or wall, was adopted, and came into general use ; but it is totally inapplicable to most of the cells in the body. The more we learned about the cells of the animal body, the more it became necessary to modify our conception of the cell ; for some cells, especially young ones, are entirely without the enveloping membrane, or stiff wall. Hence we now generally describe the cell as a living, viscous particle of protoplasm, enclosing a firmer nucleus in its albuminoid body. There maybe an enclosing membrane, as there actually is in the case of most of the plants ; but it may be wholly lacking, as is the case with most of the animals. There is no membrane at all in the first stage. The young cells are usually round, but they vary much in shape later on. Illustrations of this will be found in the cells of various parts of the body shown in Figs. 3-7. Hence the essential point in the modern idea of the cell is that it is made up of two different active constituents — an inner and an outer part. The smaller and inner part is the nucleus (or catyon, or cylob/astus, Fig. ic and Fig. 2k). The outer and larger part, which encloses the other, is the body of the cell (celleus, cytos, or cytosoma). The soft living substance of which the two are composed has a peculiar chemical composition, and belongs to the group of the albuminoid plasma-substances ("formative matter"), or protoplasm. The essential and indispensable element of the nucleus is the nuclei n (or caryoplasm) ; that of the cell body is called the plastin (or cytoplasm). In the most rudimentary cases both substances seem to be quite the cell is infinitely varied, in accordance with its endless power of adapting itself to the most diverse activities or environments. In its simplest form the cell is globular (Fig. 2). This normal globular form is especially found in cells of the simplest construction, and those that are developed in a free fluid without any external pressure. In such cases the nucleus also is not infrequently round, and located in the centre of the cell-body (Fig. 2k). In other cases, the cells have no definite shape ; they are constantly changing their form owing to their automatic movements. This is the case with the amcebce (Figs. 15 and 16) and the amoeboid travelling cells (Fig. n), and also with very young ova (Fig. 12). However, as a rule, the cell assumes a definite form in the course of its career. In the tissues of the multicellular organism, in which a number of similar cells are bound together in virtue of certain laws of heredity, the shape is determined partly by the form of their connection and partly by their special functions. Thus, for instance, we find in the mucous lining of our tongue very thin and delicate flat cells, or epithelial cells, of roundish shape (Fig. 3). In the outer skin we find similar, but harder, covering cells, joined together by saw-like edges (Fig. 4). In the liver and other glands there are thicker and softer cells, linked together in rows (Fig. 5). The last-named tissues (Figs. 3-5) belong to the simplest and most primitive type, the group of the " covering-tissues," or epithelia. In these "primary tissues" (to which the germinal layers belong) simple cells of the same kind are Fig. 5. Fig. 3. — Three epithelial cells from the mucous lining of the tongue. Fig. 4.— Five spiny OF grooved cells, with edges joined, from the outer skin (epidermis) : one of them (b) is isolated. arranged in layers. The arrangement and shape are more complicated in the " secondary tissues," which are gradually developed out of the primary, as in the tissues of the muscles," nerves, bones, etc. In the bones, for instance, which belong to the group of supporting or connecting organs, the cells (Fig. 6) are star-shaped, and are joined together by numbers of net-like interlacing processes ; so, also, in the tissues of the teeth (Fig. 7), and in other forms of supporting-tissue, in which a soft or hard substance (intercellular matter, or base) is inserted between the cells. The cells also differ very much in size. The great majority of them are invisible to the naked eye, and can be seen only through the microscope (being on an average between o.oi and o.i millimetres in diameter). There are, however, many o( the smaller plastids — such as the famous bacteria — which only come into view with a very high magnifying power. On the other hand, many cells attain a considerable size, and run to several millimetres or centimetres in diameter, as do several kinds of rhizopods among the unicellular protists (such as the radiolaria and thalamophora). Among the tissue-cells of the animal body many of the muscular fibres and nerve fibres are more than a decimetre (4 inches), and sometimes more than a metre (40 inches) in length. Among the Cells also vary considerably in structure. In this connection we must first distinguish between the active and passive components of the cell. It is only the former, or active parts of the cell, that really live, and effect that marvellous world of phenomena to which we give the name of "organic life." The first of these is the inner nucleus (caryoplasmaji and the second the body of the cell (cytoplasma). The passive portions come third ; these are subsequently formed from the others, and I have in my Generelle Morphologie (chap, ix.) given them the name of " plasma-products." They are partly external (cell-membranes and intercellular matter) and partly internal (cell-sap and cellcontents). (See the table at the end of the next Chapter.) which wecandistinguisn a more solid nuclear base (caryobasis) and a softer or fluid nuclear sap ( caryolynnph ). The nuclear base forms the enveloping membrane of globular nuclein and, as a rule, a skeleton or network of branching threads, which go out from the membrane, and pass through the cavity of the vesicle and its liquid contents. This nuclear skeleton (caryomitoma J consists of two different substances, one of which (the chromatin ) is strongly tinged with carmine and other colouring matter, and the other / 'achromia or lininj is not. In a mesh of the nuclear network (or it may be on the inner side of the nuclear envelope) there is, as a rule, a dark, very opaque, solid body, called the nucleolus. Many of the nuclei contain several of these nucleoli (as, for instance, the germinal vesicle of the ova of fishes and amphibia). Recently a very small, but particularly important, part of the nucleus has been distinguished as the central body (centrosoma) — a tiny particle that is originally found in the nucleus itself (as in the case of many spermacytes, carcinomcells, etc.), but is usually outside it, in the cytoplasm ; as a rule, fine threads stream out from it in the cytoplasm. From the position of the centrosoma with regard to the other many cells. The cell-body (celleus or cytosoma) also consists originally, and in its simplest form, o( a homogeneous viscid plasmic matter (cytoplasm ). But, as a rule, only the smaller part of it is formed of the living active cell-substance (protoplasm) ; the greater part consists of dead, passive plasmaproducts (metaplasma). It is useful to distinguish between the inner and outer of these. External plasma-products (which are thrust out from the protoplasm as solid " structural matter ") are the cell-membranes and the intercellular matter. The internal plasma-products are either the fluid cell-sap ( cy/o/ymph ) or hard structures (paraplasma). As a rule, in mature and differentiated cells these various parts are so arranged that the protoplasm (like the caryoplasm fig. 8. -Unfertilised ovum in the vesicular nucleus) forms a sort °f an eehinoderm (from lymph) and partly by hard structural products (paraplasma, or interfilar matter) ; among these there are small plasma-granules (granula or microsomata), or fat-grains (liposomata), of great importance. Besides these, we can distinguish many other products in the cytoplasm, such as concrementa, crystals, gland-granules, etc. The simple globular ovum, which we take as the startingpoint of our study (Figs, i and 2), has in many cases the vague, indifferent features of the typical primitive cell. As a contrast to it, and as an instance of a very highly differentiated plastid, we may consider for a moment a large nervecell, or ganglionic cell, from the brain. The ovum stands potentially for the entire organism — in other words, it has the faculty of building up out of itself the whole multicellular body. It is the common parent of all the countless generations of cells which form the different tissues of the body ; it unites all their powers in itself, though only potentially or in germ. In complete contrast to this, the neural cell in the brain (Fig. 9) developes along one rigid line. It cannot, like the ovum, beget endless generations of cells, of which some will become skin-cells, others muscle-cells, and others again bone-cells. But, on the other hand, the nerve-cell has become fitted to discharge the highest functions of life ; it has the powers of sensation, will, and thought. It is a real soul-cell, or an elementary organ of the psychic activity. It has, therefore, a most elaborate and delicate structure. Numbers of extremely fine threads, like the electric wires at a large telegraphic centre, cross and recross in the delicate protoplasm of the nerve-cell, and pass out in the branching processes which proceed from it and put it in communication with other nerve-cells or nerve-fibres (a, b). We can only partly follow their intricate paths in the fine nucleolar matter of the cytoplasmic body. \y Here we have a most elaborate apparatus, the delicate structure of which we are just beginning to appreciate through our most powerful microscopes, but whose significance is rather a matter of conjecture than knowledge. Its intricate structure corresponds to the very complicated functions of the mind. Nevertheless, this elementary organ of psychic activity — of which there are thousands in our brain — is nothing but a single cell. Our whole mental life is only the joint result of the combined activity of all these nerve-cells, or soul-cells. In the centre of each cell there is a large transparent nucleus, containing a small and dark nuclear body. Here, as elsewhere, it is the nucleus that determines the individuality of the cell ; it proves that the whole structure, in spite of its intricate composition, amounts to only a single cell. In contrast with this very elaborate and very strictly differentiated psychic cell (Fig. 9), we have our ovum (Figs. 1 and 2), which has hardly any structure at all. But even in the case of the ovum we must infer from its brain of an electric fish (torpedo), magnified 600 times. In the middle of the cell is the large transparent round nucleus, one nucleolus, and, within the latter again, a nucleolinus. The protoplasm ol the cell is split into innumerable fine threads (or fibrils), which are embedded in nucleolar intercellular matter, and are prolonged into the branching processes of the cell (b). One branch (a) pas^e- into a nerve-fibre. (Krom Max Schultee.) properties that its protoplasmic body has a very complicated chemical composition and a fine molecular structure which escapes our observation. This hypothetical molecular structure of the plasm is now generally admitted ; but it has never been seen, and, indeed, lies far beyond the range of microscopic vision. It must not be confused — as is often done — with the structure of the plasma (the fibrous net-work, groups of granules, honey-comb, etc.) which does come within the range of the microscope. But when we speak of the cells as the elementary organisms, or structural units, or " ultimate individualities," we must bear in mind a certain restriction of the phrases. I mean, that the cells are not, as is often supposed, the very lowest stage of organic individuality. There are yet more elementary organisms to which I must refer occasionally, and will return later on. These are what we call the " cytodes " (cytos = cell), certain living, independent beings, consisting only of a particle of plasson — an albuminoid substance, which is not yet differentiated into caryoplasm and cytoplasm, but combines the properties of both. Those remarkable beings called the monera — especially the chromacea and bacteria — are specimens of these simple cytodes. (Compare the nineteenth Chapter.) To be quite accurate, then, we must say : the elementary organism, or the ultimate individual, is found in two different stages. The first and lower stage is the cytode, which consists merely of a particle of plasson, or quite simple plasm. The second and higher stage is the cell, which is already divided or differentiated into nuclear matter and cellular matter. We comprise both kinds — the cytodes and the cells — under the name of plastids (" formative particles "), because they are the real builders of the organism. However, these cytodes are not found, as a rule, in the higher animals and plants; here we have only real cells with a nucleus. Hence, in these tissue-forming organisms (both plants and animal) the organic unit always consists of two chemically and anatomically different parts — the outer cell-body ( cytosoma) and the inner nucleus ( caryon ). independent organism, we have only to observe the development and vital phenomena of one of them. You see then that it performs all the essential functions of life — both vegetal and animal —which we find in the entire organism. Each of these tiny beings grows and nourishes itself independently. It takes its food from the surrounding fluid ; sometimes, even, the naked cells take in solid particles at certain points of their surface — in other words, " eat" them — without needing any special mouth and stomach for the purpose (cf. Fig. 19). Further, each cell is able to reproduce itself. This multiplication, in most cases, takes the form of a simple cleavage, sometimes direct, sometimes indirect ; the simple direct (or " amitotic ") division is less common, and is found, for instance, in the blood cells (Fig. 10). In these the nucleus first divides into two equal parts by constriction. The indirect (or " mitotic ") cleavage is much more frequent ; in this the caryoplasm of the nucleus and the cytoplasm of the cellbody act upon each other in a peculiar way, with a partial dissolution 1 caryolysisj, the formation of knots and loops f mitosis), and a movement of the halved plasma-particles towards two mutually repulsive poles of attraction (caryokinesis, Fig. 1 1). The intricate physiological processes which accompany this "mitosis" have been very closely studied of late years. The inquiry has led to the detection of certain laws of evolution which are of extreme importance in connection with heredity. As a rule, two very different parts of the nucleus play an important part in these changes. They are : the chromatin, or coloured nuclear substance, which has a peculiar property of tinging itself deeply with certain colouring matters (carmine, haematoxylin, etc.), and the achromin (or linin, or achromatin), a colourless nuclear substance that lacks this property. The latter generally forms in the dividing cell a sort of spindle, at the poles of which there is a very small particle, also colourless, called the "central body " (centrosoma). This acts as the centre or — Star-like appearance in cytoplasm r — Centrosoma(sphere of attraction) A— Nuclear spindle (achromin, Hj colourless matter) focus in a " sphere of attraction " for the granules of protoplasm in the surrounding cell-body, and assumes a star-like appearance (the cell-star, or monaster). The two centrosomata, standing opposed to each other at the poles of the nuclear spindle, form "the double-star" (or amphiaster,¥\g. n, B, C). The chromatin often forms a long-, irregularly-wound thread — "the coil" (spiremay Fig. A). At the commencement of the cleavage it gathers at the equator of the cell, between the stellar poles, and forms a crown of U-shaped loops (generally four or eight, or some other definite number). The loops split lengthwise into two halves (B), and these back away from each other towards the poles of the spindle (C). Here each group forms a crown once more, and this, with the corresponding half of the divided spindle, forms a fresh nucleus (D). Then the protoplasm of the cellbody begins to contract in the middle, and gather about the new daughter-nuclei, and at last the two daughter-cells become independent beings. Between this common mitosis, or indirect cell-division — which is the normal cleavage-process in most cells of the higher animals and plants — -and the simple direct division (Fig. 10) we find every grade of segmentation; in some circumstances even one kind of division may be converted into another (as, for instance, in the segmentation of the yelk-cells in discoblastic ova). The plastid is also endowed with the functions of movement and sensation. The single cell can move and creep about, when it has space for free movement and is not prevented by a hard envelope ; it then thrusts out at its surface processes like fingers, and quickly withdraws again, and thus changes its shape (Fig. 12). Finally, the young cell is sensitive, or more or less responsive to stimuli; it makes certain movements on the application of chemical and mechanical irritation. Hence we can ascribe to the individual cell all the chief functions which we comprehend under the general heading of " life " — sensation, movement, nutrition, and reproduction. All these properties of the multicellular and highly developed animal are also found in the single animal-cell, at least in its younger stages. There is no longer any doubt about this, and so we may regard it as a solid and important base of our physiological conception of the elementary organism. phenomena of the life of the cell, we will pass on to consider the application of the cell theory to the ovum. Here comparative research yields the important result that every ovum is at first a simple cell. I say this is very important, because our whole science of ontogeny now resolves itself into the problem : "How does the multicellular organism arise from the unicellular?" Every organic individual is at first a simple cell, and as such an elementary organism, or a unit of individuality. This cell produces a cluster of cells by envelopes, and so on. But when we examine them at their birth, in the ovary of the female animal, we find them to be always of the same form in the first stages of their life. In the beginning each ovum is a very simple, roundish, naked, mobile cell, without a membrane ; it consists merely of a particle of cytoplasm enclosing a nucleus (Fig. 13). Special names have been given to these parts of the ovum ; the cellbody is called the yelk fvitellusj, and the cell-nucleus the from the uncovered protoplasmic bodv. These bodies vary continually in number, shape, and size. The nucleus of these amoeboid lymphcells (" travelling- cells," or planocytes) is invisible, because concealed by the numbers of fine granules which are scattered in the protoplasm. (From Frey.) germinal vesicle r vesica la germinativa j. As a rule, the nucleus of the ovum is soft, and like a small pimple or vesicle. Inside it, as in many other cells, there is a nuclear skeleton or frame and a third, hard nuclear body (the nucleolus). In the ovum this is called the germinal spot ( macula germinal iva ). Finally, we find in many ova (but highly magnified. All the ova are naked cells of varying shape. In the dark led protoplasm (yelk) is a large vesicular nucleus (the germinal and m this is seen a nuclear body (the germinal spot), in which again we often rminal point. Figs. .1/ A4 represent the ovum of a sponge (leuculmis echinus) in lour successive movements. A'/ B8 are the ovum of a parasitic crab (chondracanthiu cornutus), in eight successive movements. (From Edward von Beneden.) Ci Cg show the ovum of the cat in various si movement (from Pfluger); Fig. I) the ovum of a trout; A' the ovum of a chicken ; Fa human ovum. not in all) a still further point within the germinal spot, a "nucleolin," which goes by the name of the germinal point (punctum germinativum). The latter parts (germinal spot and germinal point) have, apparently, a minor importance, in comparison with the other two (the yelk and germinal vesicle). In the yelk we must distinguish the active formative yelk (or protoplasm = first plasm) from the passive nutritive yelk (or deutoplasm = second plasm). Fig 14. — The human OVUm, taken from the female ovary, magnified 500 times. The whole ovum is a simple globular cell. The chief part of the globular mass is formed by the nuclear yelk (deutoplasm), which is easily distributed in the active protoplasm, and consists of numbers of fine yelk-granules. In the upperpart of the yelk is the transparent globular germinal vesicle, which corresponds to the nucleus. This encloses a darker granule, the germinal spot, which shows a nucleolus. The globular yelk is surrounded by the thick transparent germinal membranes (ovolemma, or zona pellucida). This is traversed by numbers of lines as fine as hairs, which are directed radially towards the centre of the ovum. These are called the pore-canals ; it is through these that the moving spermatozoa penetrate into the yelk at impregnation. In many of the lower animals (such as sponges, polyps, and medusa?) the naked ova retain their original simple appearance until impregnation. But in most animals they at once begin to change ; the change consists partly in the formation of connections with the yelk, which serve to nourish the ovum, and partly of external membranes for their protection (the ovolemma, or prochorion). A membrane of this sort is formed in all the mammals in the course of the embryonic process. When we examine it closely under the microscope, we see very line radial streaks in it, piercing the zona, which are really very narrow canals. The human ovum, whether fertilised or not, cannot be distinguished from that of most of the other mammals. It is nearly the same everywhere in form, size, and composition. When it is fully formed, it has a diameter of (on an average) about i'o of an inch. When the mammal ovum has been carefully isolated, and held against the light on a glass-plate, it may be seen as a fine point even with the naked eye. The ova of most of the higher mammals are about the same size. The diameter of the ovum is almost always between ■.'.■■■ and iV of a line (0.1 — 0.2 millimetres). It has always the same globular shape; the same characteristic membrane; the same transparent germinal vesicle with its dark germinal spot. Even when we use the most powerful microscope with its highest power, we can detect no material difference between the ova of man, the ape, the dog, and so on. I do not mean to say that there are no differences between the ova of these different mammals. On the contrary, we are bound to assume that there are such, at least as regards chemical composition. Even the ova of different men must differ from each other ; otherwise we should not have a different individual from each ovum. In accordance with the law of the unlikeness of individuals, we must assume that "all organic individuals differ from the very beginning of their development, though they resemble each other so much " ( Gen. Morph., Band II., S 202). It is true that our crude and imperfect apparatus cannot detect these subtle individual differences, which are probably in the molecular structure. However, such a striking morphological resemblance of their ova, so great as to seem to be a complete similarity, is a strong proof of the common parentage of man and the other mammals. round white spot, which is known as the egg-scar ( cicatricula) (Fig. 15 b). From the scar a thin column of the white yelk penetrates through small, central globule (wrongly called the yelk-cavity, or latebra, Fig. 15 d). The yellow yelkmatter which surrounds this white yelk has the appearance in the egg (when boiled hard) of concentric layers (c). The yellow yelk is also enclosed in a delicate structureless membrane (the membrana vitelline!, a). As the large yellow ovum of the bird attains a diameter of several inches in the bigger birds and encloses vesicular yelkparticles, there was formerly a reluctance to consider it as a simple cell. This, however, was an error from which His and other embrvologists have even recently drawn wrong conclusions, though it was corrected by Gegenbaur forty years ago. The unfertilised and undivided ovum of the bird remains a real cell with its simple nucleus, however large it may grow by the production of yellow yelk. Every animal that lias only one cell-nucleus, every amoeba, every gregarina, every infusorium, is unicellular, and remains unicellular whatever variety of matter it feeds on. So the ovum remains a simple cell, however much yellow yelk it afterwards accumulates within its protoplasm. Gegenbaur and Van Beneden have clearly shown this in their admirable works on the ova of mammals. It is, of course, different with the bird's egg when it has been fertilised. Then its nucleus multiplies by repeated cleavage, and the protoplasm of the cicatrix which surrounds it is similarly divided. The ovum then consists of as many cells as there are nuclei in the cicatrix. Hence, in the fertilised egg which we eat daily, the yellow yelk is already a multicellular body. Its scar is composed of several cells, and is now commonly called the germinal disc (discus blastodermicus >. We shall return to this discogastrida in the ninth chapter. When the mature bird-ovum has left the ovary and been fertilised in the oviduct, it covers itself with various membranes which are secreted from the wall of the oviduct. First, the large clear albuminous layer is deposited around the yellow yelk; afterwards, the hard external shell, with a fine inner skin. All these gradually forming envelopes and processes are of no importance in the formation of the embryo; they serve merely for the protection of the original simple ovum. We sometimes find extraordinarily large eggs with strong envelopes in the case of other animals, such as fishes of the shark type. Hut here, also, the ovum is originally of the same character as it is in the mammal ; it is a perfectly simple and naked cell. But, as in the case of the bird, a considerable quantity of nutritive yelk is accumulated inside the original yelk as food for the developing embryo ; and various coverings are formed round the egg. The ovum of many other animals has the same internal and external features. They have, however, only a physiological, not a morphological, importance; they have no direct influence on the formation of the foetus. They are partly consumed as food by the embryo, and partly serve as protective envelopes. Hence we may leave them out of consideration altogether here, and restrict ourselves to material points — to the substantial identity of the original ovum in man and the rest of the animals (Fig. 13). Now, let us for the first time make use of our biogenetic law, and directly apply this fundamental law of evolution to the human ovum. We reach a very simple, but very important, conclusion. From the fact that the human ovum and that of all other animals consists of a single cell, it follows immediately, according to the biogenetic laiv, that all the animals, including man, descend from a unicellular organism. If our biogenetic law is true, if the embryonic development is a summary or condensed recapitulation of the stem-history — and there can be no doubt about it — we are bound to conclude, from the fact that all the ova are at first simple cells, that all the multicellular organisms originally sprang from a unicellular being. And as the original ovum in man and all the other animals has the same simple and indefinite appearance, we may assume with some probability that this unicellular stem-form was the common ancestor of the whole animal world, including man. However, this last hypothesis does not seem to me as inevitable and as absolutely certain as our first conclusion. Thisjnference from the unicellular embryonic form to the unicellular ancestor is so simple, but so important, that we cannot sufficiently emphasise it. We must, therefore, turn next to the question whether there are to-day any unicellular organisms, from the features of which we may draw some approximate conclusion as to the unicellular ancestors of the multicellular organisms. The answer is : Most certainly there are. There are assuredly still unicellular organisms which are, in their whole nature, really nothing more than permanent ova. There are independent unicellular organisms of the simplest character which develop no further, but reproduce themselves as such, without any further growth. We know to-day of a great number o( these little beings, such as the gregarina, flagellata, acineta, infusoria, etc. However, there is one of them that has an especial interest for us, because it at once suggests itself when we raise our question, and it must be regarded as the unicellular being that approaches nearest to the real ancestral form. This organism is the amoeba. inis unicellular body moves about nucieoiUSl continually, creeping in every direction on the glass on which we are examining it. The movement is effected by the shapeless body thrusting out finger-like processes at various parts of its surface; and these are slowly but continually changing, and drawing the rest of the body after them. After a time, perhaps, the action changes. The amceba suddenly stands still, withdraws its projections, and assumes a globular shape. In a little while, however, the globular body begins to expand again, thrusts out arms in another direction, and moves on once more. These changeable processes are called "false feet," or pseudopodia, because they behave physiologically as feet, yet are not special organs in the anatomic sense. They disappear as quickly as they come, and are nothing more than temporary projections of the semifluid, homogeneous, and structureless body. If you touch one of these creeping amoeba; with a needle, or put a drop of acid in the water, the whole body at once contracts in consequence of this mechanical or physical stimulus. As a rule, the body then resumes its globular shape. In certain circumstances — for instance, if the impurity of the water lasts some time — the amcebas begins to develop a covering. It exudes a homogeneous membrane or capsule, which immediately hardens, and assumes the appearance of a globular cell with a protective membrane. The amoeba either takes its food directly by imbibition of matter floating in the water, or by pressing into its protoplasmic body solid particles with which it comes in contact. The latter process may be observed at any moment by forcing it to eat. If finely ground colouring matter, such as carmine or indigo, is put into the water, you can see the soft body of the amoeba pressing these coloured particles into itself, the substance of the cell closing round them. The amoeba can take in food in this way at any point on its surface, without having any special organs for intussusception and digestion, or a real mouth or gut. The amoeba grows by thus taking in food and dissolving the particles eaten in its protoplasm. When it reaches a certain size by this continual feeding, it begins to reproduce. This is done by the simple process of cleavage (Fig. 17). First, the nucleus divides into two parts. Then the protoplasm is separated between the two new nuclei, and the whole cell splits into two daughter-cells, the protoplasm gathering about each of the nuclei. The thin bridge of protoplasm which at first connects the daughter-cells soon breaks. Here we have the simple form of direct cleavage of the nuclei. Without mitosis, or formation of threads, the homogeneous nucleus divides into two halves. These move away from each other, and become centres of attraction for the enveloping matter, the protoplasm. The same direct cleavage o( the nuclei is also witnessed in the reproduction oi' many other protists, while other unicellular organisms show the indirect division of the cell. Hence, although the amoeba is nothing but a simple cell, it is evidently able to accomplish all the functions of the multicellular organism. It moves, feels, nourishes itself, and reproduces. Some kinds of these amoebae can be seen with the naked eye, but most of them are microscopically small. Fig. 17. —Division of a unicellular amoeba (amoeba polypodia) in six stages. (From F. E. Stluiltze.) The dark spot is the nucleus, the lighter spot a contractile vacuole in the protoplasm. The latter re-forms in one of the daughter-cells. It is for the following reasons that we regard the amoeba; as the unicellular organisms which have special phylogenetic (or evolutionary) relations to the ovum. In many of the lower animals the ovum retains its original naked form until fertilisation, developes no membranes, and is then often indistinguishable from the ordinary amceba. Like the amoeba?, these naked ova may thrust out processes, and move about as travelling cells. In the sponges these mobile ova move about freely in the maternal body like independent amoeba; (Fig. 17). They had been observed by earlier scientists, but described as foreign bodies — namely, parasitic amoeba;, living parasitically on the body of the sponge. Later, however, it was discovered that they were not parasites, but the ova of the sponge. We also find this remarkable phenomenon among other animals, such as the graceful, bell-shaped zoophyta, which we call polyps and medusa;. Their ova remain naked cells, which thrust out amoeboid projections, nourish themselves, and move about. When they have been fertilised, the multicellular organism is formed from them by repeated segmentation. It is, therefore, no audacious hypothesis, but a perfectly sound conclusion, to regard the amoeba as the particular unicellular organism which offers us an approximate illustration of the ancient common unicellular ancestor of all the metazoa, or multicellular animals. The simple naked amoeba has a less definite the bodv of the sponge that recent research has discovered such ftaKJp^Tu amoeba-like cells everywhere in the is indistinguishable from mature body of the multicellular animals. They are found, for instance, in the human blood, side by side with the red corpuscles, as colourless blood-cells ; and it is the same with all the vertebrates. They are also found in many of the invertebrates — for instance, in the blood of the snail. I showed, in 1859, that these colourless blood-cells can, like the independent amoeba;, take up solid particles, or "eat" (whence they are called phagocytes = "eating-cells," Fig. 19). Lately, it has been discovered that many different cells may, if they have room enough, execute the same movements, creeping about and eating. They behave just like amoeba; (Fig. 12). It has also been shown that these " travelling-cells," or planocy tes, play an important part in man's physiology and pathology The power of the naked cell to execute these characteristic amoeba-like movements comes from the contractility (or automatic mobility) of its protoplasm. This seems to be a universal property of young cells. When they are not enclosed by a firm membrane, or confined in a "cellular prison," they can always accomplish these amceboid movements. This is true of the naked ova as well as of any other naked cells, of the tion of man. We nave learned that the human ovum is a simple cell, that this ovum is not materiallv different from that of other mammals, and that we may conclude from it to the existence of a primitive unicellular ancestral form, witli a substantial resemblance to the amoeba. The statement that the earliest progenitors of the human race were simple cells of this kind, and led an independent unicellular life like the amoeba, has not only been ridiculed as the dream of a natural philosopher, hut also been violently censured in theological journals as " shameful and immoral." But, as I observed in my essay On (tie Origin and Ancestral magnified. I was the first to observe ill the bloodcells of tliis snail tin- important fact that "the blood-cells of the invertebrates are unprotected pieces of plasm, and take in food, by means of their peculiar movements, like the amoeba?." I had (in Naples, on May ioth, 1859) injected into the blood-vessles of one of these snails an infusion oi water and ground indigo, and was greatly astonished to find the blood-cells themselves more or less filled with the particles of indigo after a few hours. After repeated injections I succeeded in "observing the very entrance o\~ the coloured particles in the blood-cells, which took place just in the same way as with the amoeba." I have given further particulars about this in my Monograph oil the Radiolaria. Tree of the Human Race in 1870, this offended piety must equally protest against the " shameful and immoral " fact that each human individual is developed from a simple ovum, and that this human ovum is indistinguishable from those of the other mammals, and in its earliest stage is like a naked amoeba. It is as indisputable as the momentous conclusions we draw from it and as the vertebrate character of man (see Chapter XL). We now see very clearly how extremely important the cell theory has been for our whole conception of organic nature. " Man's place in nature " is settled beyond question by it. Apart from the cell theory, man is an insoluble enigma to us. Hence philosophers, and especially physiologists, should be thoroughly conversant with it. The soul of man can only be really understood in the light of the cell-soul, and we have the simplest form of this in the amoeba. Only those who are acquainted with the simple psychic functions of the unicellular organisms and their gradual evolution in the series of lower animals can understand how the elaborate mind of the higher vertebrates, and especially of man, was gradually evolved from them. The academic psychologists who lack this zoological equipment are unable to do so. This naturalistic and realistic conception is a stumblingblock to our modern idealistic metaphysicians and their theological colleagues. Fenced about with their transcendental and dualistic prejudices, they attack not only the monistic system we establish on our scientific knowledge, but even the plainest facts which go to form its foundation. An instructive instance of this was seen three years ago, in the academic discourse delivered by a distinguished theologian, Willibald Beyschlag, at Halle, January 12th, 1900, on the occasion of the centenary festival. The theologian protested violently against the " materialistic dustmen of the scientific world who offer our people the diploma of a descent from the ape, and would prove to them that the genius of a Shakespeare or a Goethe is merely a distillation from a drop of primitive mucus." Another well-known theologian protested against the horrible idea that the greatest of men, Luther and Christ, were descended from a mere globule of protoplasm." Nevertheless, not a single informed and impartial scientist doubts the fact that these greatest men were, like all other men — and all other vertebrates — developed from an impregnated ovum, and that this simple nucleated globule of protoplasm has the same chemical constitution in all the mammals. The actual amoeba? and other unicellular organisms (arcella, radiolaria, etc.) are of great importance for our conclusion, because they exhibit these single cells to us in permanent independence, as autonomous cells. The human organism and that of the other higher animals are only onecelled in the earliest stage of existence. As soon as the ovum is fertilised, it increases by segmentation, and forms a group or colony of social cells, a cell-community or a ccenobium. These take on different forms, and, by a division of labour among the cells and their development along different lines, the multifarious tissues that make up the animal body are produced. Thus the mature multicellular organism of man and the other higher animals and plants is a his ton (or " tissue-body "), a social community of the various kinds of tissue-cells. The innumerable organic units in this " histon " may vary considerably when their development is complete, but they were originally simple cells of the same type, the equal citizens of the cell-state. CHAPTER VII. Nature of conception ; fusion of the female ovum and male spermatozoon. Various forms of the sperm-cells (usually cone-shaped ciliary cells). Theory of the spermatozoa. Inheritance from both parent-cells. The new stem-cell or cytula. Its hermaphroditic character. Process of fertilisation of ovum : release of the germinal vesicle and protrusions of the directing- body. Penetration of a spermatozoon in the body of the ovum : movement and blending of the two pronuclei. Formation of the stem-nucleus ( archicaryon ), the vehicle of ir'ieritance. Older theories of conception. Importance and equal share ice of all that is personal and individual. Th: recognition of the fact that every man begins his individual existence as a simple cell is the solid foundation of all research into the genesis of man. From this fact we are forced, in virtue of our biogenetic law, to draw the weighty phylogenetic conclusion that the earliest ancestors of the human race were also unicellular organisms ; and among these protozoa we may single out the vague form of the amoeba as particularly important (cf. Chapter VI.). That these unicellular ancestral forms did once exist follows directly from the phenomena which we perceive every day in the fertilised ovum. The development of the multicellular organism from the ovum, and the formation of the germinal layers and the tissues, follow the same laws in man and all the higher animals. It will, therefore, be our next task to consider more closely the impregnated ovum and the process of conception which produces it. The process of impregnation or sexual conception is one of those phenomena that people love to conceal behind the mystic veil of supernatural power. We shall soon see, however, that it is a purely mechanical process, and can be reduced to familiar physiological functions. Moreover, this amphigony (or conception) is of the same type, and is effected bv the same organs, in man as in all the other mammals. The pairing of the male and female has in both cases for its main purpose the introduction of the ripe matter o( the male seed or sperm into the female body, in the sexual canals of which it encounters the ovum. Conception then ensues by the blending of the two. We must observe, first, that this important process is by no moans so widely distributed in the animal and plant world as is commonly supposed. There is a very large number of lower organisms which propagate unsexually, or by monogony, and especially the sexless monera (chromacea, bacteria, etc), but also many other protists, such as the amoeba;, foraminifera, radiolaria, myxomycetae, etc. In these there is no fertilisation whatever; the multiplicatir F individuals and propagation of the species take plae< y unsexual reproduction, which takes the form of cleav ;e, budding, or spore-formation. The copulation of two coal scing cells, which in these cases often precedes the reproduction, cannot be regarded as a sexual act when the two copulating plastids differ in size or structure (microspores and macrospores). On the other hand, sexual reproduction is the general rule with all the higher organisms, both animal and plant ; very rarely do we find asexual reproduction among them. There are, in particular, no cases of parthenogenesis (virginal conception) among the vertebrates. Sexual reproduction offers an infinite variety of interesting forms in the different classes of animals and plants, especiallv as regards the mode of conception, and the conveyance of the spermatozoon to the ovum. These features are of great importance not only as regards conception itself, but for the development of the organic form and especially for the differentiation of the sexes. There is a particularly curious correlation of plants and animals in this respect. The splendid studies o( Charles Darwin and Hermann Miiller on the fertilisation of flowers by insects have given us very interesting particulars of this.1 This reciprocal service has given rise to tures have been developed in man and the higher animals, serving partly for the isolation of the sexual products on each side, partly for bringing them together in conception. But, however interesting these phenomena are in themselves, we cannot go into them here, as they have only a minor importance — if any at all — in the real process of conception. We must, however, try to get a very clear idea of this process and the meaning of sexual reproduction. In every act of conception we have, as I said, to consider two different kinds of cells — a female and a male cell. The female cell of the animal organism is always called the ovum (or ovulum, egg, or egg-cell) ; the male cells are known as the sperm or seed-cells, or the spermatozoa (also spermium and zoospermium). The female ovum, the form and composition of which we have already considered, is of the same simple nature in the early stages in all the animals. It is at first merely a globular naked cell, consisting of protoplasm and a nucleus (Fig. 13). When it has freedom to move, it often makes slow amoeboid movements, as we have seen in the case of the ovum of the sponge (Fig. 18). But, as a rule, it is enclosed subsequently by a number of very different, and often very complicated, shells or membranes. The ripe ovum is, on the whole, one of the largest cells we know. It attains colossal dimensions when it absorbs great quantities of nutritive yelk, as is the case with birds and reptiles, and many of the fishes. In the great majority of the animals the ripe ovum is rich in yelk and much larger than the other cells. On the other hand, the next cell which we have to consider in the process of conception, the male sperm-cell or spermatazoon, is one of the smallest cells in the animal body. Conception usually consists in the bringing into contact with the ovum of a slimy fluid secreted by the male, and this may take place either inside or out of the female body. This fluid is called sperm, or the male seed. Sperm, like saliva or blood, is not a simple fluid, but a thick agglomeration of innumerable cells, swimming about in a comparatively small male cells that swim in it, that cause conception. The spermatozoa of the great majority of animals have two characteristic features. Firstly, they are extraordinarily small, being usually the smallest cells in the body ; and, secondly, they have, as a rule, a peculiarly lively motion, which is known as spermatozoic motion. The shape of the cell has a good deal to do with this motion. In most of the animals, and also in many of the lower plants (but not the higher), each of these spermatozoa has a very small, naked Fig. 20.- Spermia or spermatozoa from the male sperm of various mammals. The pear-shaped flattened nucleus of the seed-cell (the so-called •■ head of the spermatozoon ") is seen from the front in /. , and sideways in //. k i-. the nucleus, "/ its middle pari (protoplasm), s the mobile, serpent-like tail (or whip) ; .1/ four human spermatozoa, .i four spermatozoa from the ape; A' from the hare ; H from the house-mouse ; C from the dog- ; S from the pig. cell-body, enclosing an elongated nucleus, and a long thread hanging from it (Fig. 20). It was long before we could recognise that this structure is a simple cell. Thev were formerly held to be special organisms, and were called "seedanimals" (spermato-zoa, or spermato-zoidia) ; they are now scientifically known as spermia or spermidia, or as spermatosomata (seed-bodies) or spermatofila (seed threads). It took a good deal of comparative research to convince us that each of these spermatozoa is really a simple cell. They have the same shape as in many other vertebrates and most of the invertebrates. However, in many of the lower animals they CO.XCEPTIOX have quite a different shape. Thus, for instance, in the river crab thev are large round cells, without any movement, equipped with stiff outgrowths like bristles (Fig. 21/). They have also a peculiar form in some of the worms, such as the thread-worms (filarial; in this case, they are sometimes amoeboid and like very small ova (Fig. 21 c-e). But in most of the lower animals (such as the sponges and polyps) they have the same pine-cone shape as in man and the other mammals (Fig. 21 a, h). When the Dutch naturalist Leeuwenhoek discovered these thread-like lively particles in 1677 in the male sperm, it was generally believed that they were special, independent, tiny animalcules, like the infusoria, and so were called " seed-animals " or spermatozoa. I have already pand and grow in all its parts. This erroneous view is now wholly abandoned ; we know by the most accurate investigation that the mobile spermatozoa are nothing but simple and real cells, of the kind that we call " ciliated " (equipped with lashes, or cilia). In the previous illustrations we have distinguished in the spermatozoon a head, trunk, and tail. The " head " (Fig. 20 k) is merely the oval nucleus of the cell; the body or middle-part (m) is an accumulation of cell-matter ; and the tail (s) is a thread-like prolongation of the same. all a peculiar form of cell ; precisely similar cells are found in various other parts of the body. If they have many short threads projecting, they are called ciliated; if only one long, whip-shaped process (or, more rarely, two or four), caudate (tailed) cells. Caudate cells, like those of the spermatozoa, are found in the gastric cells of the sponges and the cnidaria. Very careful recent examination of the spermia, under a very high microscopic power (Fig. 22 a, b), has detected some further details in the liner structure of the ciliated cell, and these are common to man and the anthropoid ape. The head (k) encloses the elliptic nucleus in a thin envelope of cytoplasm; it is a little flattened on one side, and thus looks rather pear-shaped from the front (b). In the central piece (w) we can distinguish a short neck and a longer connective piece (with centrosoma). The tail consists of a long main section (//) and a short, very fine tail (e). The process of fertilisation by sexual conception consists, therefore, essentially in the coalescence and blending together of two different cells. The most curious opinions prevailed about this act formerly. People always saw something mystic about it, and framed the most marvellous hypotheses on it. It is only in the last ten years that we have learned that the process of with a female ovum. The lively spermatozoon travels towards the ovum by its serpentine movements, and bores its way into the female cell (Fig. 23). The nuclei ot both sexual cells, attracted by a certain "affinity," approach each other and melt into one. This would be an admirable place for poetic description in the most glowing colours of the wonderful mystery of conception and the struggle of the living spermatozoa, which hover anxiously about the ovum, seeking to penetrate nto the fine porous canals of the ovolemma and plunge " consciously " into the protoplasmic yelk, where they die away to find their higher selves. The supporters of teleology, too, might pause here to admire the wisdom of the Creator in providing these porous canals in the membrane of the ovum for the spermatozoa to enter through. However, the scientist coldly describes this process — this " crowning of love " — as a blending of two cells and the combination of their nuclei. The new cell that arises from the process is the simple product of the copulation of the two blending sexual cells. Hence the fertilised cell is quite another thing from the unfertilised cell. For if we must regard the spermia as real cells no less than the ova, and the ovum is invisible. the ovum a part of the mother s body. This is clear from the fact that the child inherits many features from both parents. It inherits from the father by means of the spermatozoon and from the mother by means of the ovum. The actual blending of the two cells produces a third cell, which is the germ of the child, or the new organism conceived. One may also say of this sexual ■coalescence that the stem-cell is a simple hermaphrodite ; it unites both sexual substances in itself. I think it necessary to emphasise the fundamental importance of this simple, but often unappreciated, feature in order to have a correct and clear idea of conception. With that end, I have given a special name to the new cell from which the child developes, and which is generally loosely called " the fertilised ovum " or " the first segmentation sphere." I call ii "the stem-cell" (cytula or archicytos ,, its cell-matter "the stem-plasm" (archiplasma or cytuloplasma ) , and its The name " stem-cell " seems to me the simplest and most suitable because all the other cells o( the body are derived from it, and because it is, in the strictest sense, the stemfather and stem-mother ol~ all the countless generations of cells o( which the multicellular organism is to be composed. That complicated molecular movement o( the protoplasm which we call "life" is, naturally, something quite different in this stem-cell from what we find in the two parent-cells, from the coalescence o\ which it has issued. The life of the stem-cell or cytula is the product or resultant of the paternal life-movement that is conveyed in the spermatozoon and the maternal life-movement that is contributed by the ovum. On the principle of the parallelogram o\ forces, it may be said that the potential energy of the stem-cell is the diagonal of the parallelogram, while its two sides represent the potential energy ot the paternal spermatozoa and that of the maternal bvum. The combined potential energy of the two, or the hereditary potentiality, is converted into living force as soon as the individual development of the stem-cell begins after the coalescence. The admirable work done by recent observers has shown that the individual development, in man and the other animals, commences with the formation of a simple " stemcell " k^' this character, and that this then passes, by repeated segmentation (or fission), into a cluster oi cells, known as " the segmentation sphere " or " segmentation cells" (segmentella or blastomeraj. L'ntil 1875 there was a spirited controversy as to the origin of the stem-cell, and as to the real behaviour oi the spermatozoon and the ovum in its formation or at conception. It had been generally assumed that the original nucleus o( the ovum, called the germinal vesicle, remained unchanged at conception, and passed over directly to the stem-nucleus (or nucleus of "the first segmentation sphere"). However, most modern observers are convinced that the germinal vesicle sooner or later disappears, and that the stem-nucleus is a new formation. But there were different opinions as to the mode of formation of this new nucleus of the stem-cell. Some thought that the germinal vesicle disappeared before impregnation and some after. Some said that it was thrust out of the ovum, and others that it melted away in the velk. Some believed that it was wholly, and others that it was only partially, lost. All these contradictory opinions and difficulties about these important processes have now been happilv settled. The solution began in 1875, when a number of very careful microscopic studies of them were published about the same time, especially those of Oscar Hertwig and Edward Strasburger (both then at Jena), Edward Van Beneden, O. Biitschli, etc. By the work of these many succeeding observers we have gradually come to a happy agreement as to the essential features of conception, and are convinced that it has the same physiological features in the whole animal and plant worlds. This is most clearly observed in the ova of the echinoderma (star-fishes, sea urchins, sea-gherkins, etc.). The investigations of Oscar and Richard Hertwig were chiefly directed to these. The main results may be summed up as follows : — Conception is preceded by certain preliminary changes, which are very necessary — in fact, usually indispensable — for its occurrence. They are comprised under the general heading of "Changes prior to impregnation." In these the original nucleus of the ovum, the germinal vesicle, is lost. Part of it is extruded, and part dissolved in the cell contents ; only a very small part of it is left to form the basis of a fresh nucleus, the pronucleus femininus. It is the latter alone that combines in conception with the invading nucleus of the fertilising spermatozoon (the pronucleus masculinusj. The impregnation of the ovum commences with a decay of the germinal vesicle, or the original nucleus of the ovum (Fig. 24). We have seen that this is in most unripe ova a large, transparent, globular vesicle. This germinal vesicle LIBRARY. contains a viscous fluid (the caryofympm). j^ffie) I'M1) »ihoM^jJuIJ.E frame (caryobasis) is formed oi the enveloping membrane and a mesh-work of nuclear threads running across the interior, which is filled with the nuclear sap. In a knot o\ the network is contained the dark, stiff, opaque nuclear corpuscle or nucleolus. When the impregnation of the ovum sets in, (he greater part of the germinal vesicle is dissolved in the cell; the nuclear membrane and mesh-work disappear; tile nuclear sap is distributed in the protoplasm ; a small portion of the nuclear base is extruded ; another small portion is left, and is converted into the secondary nucleus, or the female pro-nucleus (Fig. 25 rk). bodies" or "polar cells"; there are many disputes as to their origin and significance, but we are as yet imperfectl) acquainted with them. As a rule, they are two small round granules, o( the same size and appearance as the remaining pro-nucleus. The polar cells arise successively by the constriction or cleavage of that part oi the nuclear base (probably, as a rule, the germinal spot) which also forms the female pro-nucleus. We may, therefore, regard this cleavageprocess, in which the surrounding protoplasm shares, as a twice-repeated cell division, or, rather, as a gemmation (budding) of cells ; because the two parts into which the impregnated ovum divides each time are not of the same size and appearance. The two small polar cells are detached cellbuds; their separation from the large mother-cell takes place in the same way as in ordinary " indirect cell-division," with the formation of nuclear spindle, plasma stars, polar radiation, halving of the nuclear spindle, mitosis, etc. Hence, the polar cells are probably to be conceived as " abortive ova," or " rudimentary ova," which proceed from a simple original ovum by cleavage in the same way that several sperm-cells arise from one spermatoblast, or one "sperm-mother-cell," in spermatogenesis. The male sperm-cells in the testicles must undergo similar changes in view of the coming impregnation as the ova in the female ovary. In this maturing of the sperm each of the original seed-cells (spermatoblasts or spermatogonia J divides by double segmentation into four daughter-cells, each furnished with a fourth of the original nuclear matter (the hereditary chromatin); and each of these four descendant cells becomes a spermium or spermatozoon, ready for impregnation. Thus is prevented the doubling of the chromosomata and the hereditative chromatin in the coalescence of the two nuclei at conception. As the two polar cells are extruded and lost, and have no further part in the fertilisation of the ovum, we need not discuss them any further. But we must give more attention to the female pro-nucleus which alone remains after the extrusion of the polar cells and the dissolving of the germinal vesicle (Fig. 23 ek). This tiny round corpuscle of chromatin now acts as a centre of attraction for the invading spermatozoon in the large ripe ovum, and coalesces with its " head," the male pro-nucleus. The product of this blending, which is the most important part of the act of impregnation, is the stem-nucleus, or the first segmentation nucleus ( arcliicaryon 1 — that is to say, the nucleus of the new-born embryonic stem-cell or "first segmentation cell " (archicytos or cytulaj. This stem-cell is the starting-point of the subsequent embryonic processes. Hertwig has shown that the tiny transparent ova of the echinoderms are the most convenient for following the details of this important process of impregnation. We can, in this case, easily and successfully accomplish artificial impregnation, and follow the formation o( the stem-cell step by step within the space k^\ ten minutes. If we put ripe ova o( the star-fish or sea-urchin in a watch-glass with sea-water and add a drop o( ripe sperm-fluid, we find each ovum impregnated within five minutes. Thousands of the fine, mobile ciliated cells, which we have described as " sperm-threads" (Fig. 20), make their way to the ova, owing to a sort o( chemical sensitive action which may he called " smell." But only one o( these innumerable spermatozoa is chosen — namely, the one that first reaches the ovum by the serpentine motions of its tail, and touches the ovum with its head. At the spot .1 Fig. _o. Impregnation of the ovum of a star-fish. (From Hertwig.) Only ;i small part of the surface of the ovum is shown. One of the numerous spermatozoa approaches the "impregnation rise" (A), touches it (BJ, and then penetrates into the protoplasm of the ovum ( Cj. where the point o( its head touches the surface of the ovum the protoplasm of the latter is raised in the form of a small wart, the "impregnation rise" (Fi,^r. 26 A). The spermatozoon then bores its way into this with its head, the tail outside wriggling about all the time (Fig. 26 />, C). Presently the tail also disappears within the ovum. At the same time the ovum secretes a thin external yelk-membrane (Fig. 26 C), Starting from the point o\ impregnation; and this prevents any more spermatozoa from entering. Inside the impregnated ovum we now see a rapid series o\ most important changes. The pear-shaped head o( the sperm-cell, or the "head o\ the spermatozoon," grows larger and rounder, and is converted into the male pro-nucleus (Fig. 27 $ k). This has an attractive influence on the fine granules or microsomata which are distributed in the protoplasm of the ovum ; they arrange themselves in lines in the figure of a star (cytulaster). But the attraction or the " affinity " between the two nuclei is even stronger. They move towards each other inside the yelk with increasing speed, the male (Fig. 28 j k) going more quickly than the female nucleus (e k). The tiny male nucleus takes with it the radiating mantle which spreads like a star about it. At last the two sexual nuclei touch (usually in the centre of the globular ovum), lie close together, are flattened at the points of contact, and coalesce into a common mass. The small mantle of protoplasm. central particle of nuclein which is formed from this combination of the nuclei is the stem-nucleus, or the first segmentation nucleus (archicaryon or eytulocaryon J ; the new-formed cell, the product of the impregnation, is our stem-cell, or "first segmentation sphere" (cytttla or archicytos, Fig. 29). Hence the one essential point in the process of sexual reproduction or impregnation is the formation of a new cell, the stem-cell. This cytula is always the resultant of the combination of two originally different cells, the female ovum and the male spermatozoon. This process is of the highest importance and merits our closest attention ; all that happens in the later development of this first cell and in the life of the organism that comes of it is determined from the first by the chemical and morphological composition of the stem-cell, Its nucleus and its body. We must, therefore, make a very careful study of the rise and structure of the stem-cell. The first question that arises is as to the behaviour of the two different active elements, the nucleus and the protoplasm, in the actual coalescence. It is obvious that the nucleus plays the more important part in this. Hence Hertwig puts his theor) of conception in the principle : "Conception consists in the copulation of two cell-nuclei, which come from a male and a female cell." And as the phenomenon of heredity is inseparably connected with the reproductive process, we may further conclude that these two copulating nuclei "convey the characteristics which are transmitted from parents to offspring." In this sense I had in 1866 (in the ninth chapter of the Generelle Morphologie) ascribed to the reproductive nucleus the function ol generation and heredity, and to the nutritive protoplasm the duties of nutrition and adaptation. As, moreover, there is a complete coalescence of the mutually attracted nuclear substances in conception, and the new nucleus formed (the stem-nucleus) is the real starting-point for the development of the fresh organism, the further conclusion may be drawn that the male nucleus conveys to the child the qualities of the father, and the female nucleus the features oi the mother. We must not forget, however, that the protoplasmic bodies of the copulating cells also fuse together in the act of impregnation ; the cell-body of the invading spermatozoon (the trunk and tail oi the male ciliated cell) is dissolved in the yelk oi the female ovum. This coalescence is not so important as that oi the nuclei, but it must not be overlooked ; and, though this process is not so well known to us, we see clearly at least the formation of the star-like Mention must also be made of the reciprocal action o\~ the cell-constituents on both sides. The formation of the protoplasmic star around the invading male nucleus, and afterwards round the copulated stem-nucleus, suggests the idea that this alone has an active influence on the arrangement of the granules and threads in the protoplasm. However, the reproductive nucleus itself changes its size, shape, and consistency, and is on its side influenced, from the conditions under which it is nourished, by the nutritive protoplasm. How close the interaction of the two elements is can be seen at once from the above-mentioned preliminary processes of the maturing of the ovum before impregnation, and from the segmentation processes that follow it. In both cases we observe the complete phenomena of caryokinesis and mitosis, which are found always in indirect cleavage, and which reveal to us the significant interaction of cell-nucleus and cell-body. These phenomena have also been called caryolysis, or the " dissolving of the nucleus in the protoplasm." This may be granted up to a certain point, and used in support of our monera theory — for the belief that the oldest and simplest organisms were innucleated plastids, and that the real unicellular forms of life were subsequently developed from these by the cleavage of nucleus and cell-body. (Cf. the nineteenth Chapter.) The older theories of impregnation generally went astray in regarding the large ovum as the sole base of the new organism, and only ascribed to the spermatozoon the role of stimulating and originating its development. The stimulus which it gave to the ovum was sometimes thought to be purely chemical (a catalytic process), at other times rather physical (on the principle of transferred movement), or again quite dualistic (that is, a mystic and transcendental process). This error was partly due to the imperfect knowledge at that time of the facts of impregnation, and partly to the striking difference in the sizes of the two sexual cells. Most of the earlier observers thought that the spermatozoon did not penetrate into the ovum. And even when this had been demonstrated, the spermatozoon was believed to disappear in the ovum without leaving a trace. However, the splendid research made in the last three decades with the finer technical methods of our time has completely exposed the error o( this. It lias been shown that the tiny sperm-cell is not subordinated to, but co-ordinated with, the large ovum. The nuclei of the two cells, as the vehicles o\ the hereditary features of the parents, are of equal physiological importance. In some cases we have succeeded in proving that the mass of the active nuclear substance which combines in the copulation o( the two sexual nuclei is orginally the same for both. Edward Van Beneden has shown that in the ovum of the horse maw-worm f ascaria megalocephcUa) the union of the two sexual nuclei is delayed until the stem-cell created begins to divide. The characteristic nuclear spindle which is then formed, and which falls into the nuclei of the two first segmentation daughter-cells, is formed half of the nucleus of the ovum and half of the sperm-nucleus ; of the four " daughter-loops " of the segmentation spindle two are of male and two of female origin. These morphological facts are in perfect harmony with the familiar physiological truth that the child inherits from both parents, and that on the average they are equally distributed. But it is also possible that the determination of the latter — the weighty determination whether the child is to be a boy or a girl — depends on a slight qualitative or quantitative difference in the nuclein or the chromatic nuclear matter which comes from both parents in the act of conception. The striking differences of the respective sexual cells in si/.e and shape, which occasioned the erroneous views >t earlier scientists, are easily explained on the principle ol division of labour, or ergonomy. The inert, motionless ovum grows in size according to the quantity o\~ provision it stores up in the form of nutritive yelk for the development of the germ. The active swimming sperm-cell is reduced in size in proportion to its need to seek the ovum and bore its way into its yelk. These differences are very conspicuous in the higher animals, but they are much less in the lower animals. In those protists (unicellular plants and animals) which have the first rudiments of sexual reproduction the two copulating cells are at first quite equal. In these cases the act of impregnation is nothing more than a sudden growth, in which the originally simple cell doubles its volume, and is thus prepared for reproduction (cell-division). Afterwards slight differences are seen in the size of the copulating cells ; though the smaller microspores (or microgonidia) still have the same shape as the larger macrospores (or macrogonidia). It is only when the difference in size is very pronounced tli£ a notable difference in shape is found : the sprightly sperr cell changes more in shape and the ovum in size. Quite in harmony with this new conception of /the equivalence of the two gonidia, or the equal physiological importance of the male and female sex-cells and their equal share in the process of heredity, is the important fact established by Hertwig (1875), that in normal impregnation only one single spermatozoon copulates with one ovum ; the membrane which is raised on the surface of the yelk immediately after one sperm-cell has penetrated (Fig. 26 C) prevents any others from entering. All the rivals of the fortunate penetrator are excluded, and die without. But if the ovum passes into a morbid state, if it is made stiff by a lowering of its temperature or stupefied with narcotics (chloroform, morphia, nicotine, etc.), two or more spermatozoa may penetrate into its yelk-bcdy. We then witness polyspermism. The more Hertwig chloroformed the ovum, ie more spermatozoa were able to bore their way into its unconscious body. These remarkable facts of impregnation are also of the greatest interest in psychology, especially as regards the theory of the cell-soul, which I consider to be its chief foundation. All the phenomena we have described can only be understood and explained by ascribing a certain lower degree of psychic activity to the sexual principles. They feel each other's proximity, and are drawn together by a sensitive impulse (probablj related to smell) ; they move towards each other, and do not rest until they fuse together. Physiologists may say that it is only a question of a peculiar physicochemical phenomenon, and not a psychic action ; but the two cannot be separated. Even the psychic functions, in the strict sense of the word, are only complex physical processes, or "psycho-physical" phenomena, which are determined in all cases exclusively by the chemical composition of their material substratum. The monistic view of the matter becomes clear enough when we remember the radical importance of impregnation as regards heredity. It is well known that not only the most delicate bodily structures, but also the subtlest traits of mind, are transmitted from the parents to the children. In this the chromatic matter of the male nucleus is just as important a vehicle as the large caryoplasmic substance of the female nucleus ; the one transmits the mental features of the father, and the other those of the mother. The blending of the two parental nuclei determines the individual psychic character of the child. But there is another important psychological question — the most important of all — that has been definitely answered by the recent discoveries in connection with conception. This is the question of personal immortality. This dogma, which we meet in the most varied forms among uncivilised peoples, occupies an important place also in the higher conceptions of civilised nations. But the fact that it is untenable has been growing clearer and clearer during the last fifty years, chiefly through the vast progress we have made in comparative morphology, experimental physiology, empirical psychology, psychiatry, monistic anthropology, and ethnography. However, no fact throws more light on it and refutes it more convincingly than the elementary process of conception that we have described. For this copulation ot the two sexual nuclei (Figs. 27-29) indicates the precise moment at which the individual begins to exist. All the bodily and mental features of the new-born child are the sum-total of the hereditary qualities which it has received in reproduction from parents and ancestors. All that man acquires afterwards in life by the exercise of his organs, the influence of his environment, and education — in a word, by adaptation — cannot obliterate that general outline of his being which he inherited from his parents. But this hereditary disposition, the essence of every human soul, is not "eternal," but "temporal"; it comes into being only at the moment when the sperm-nucleus of the father and the nucleus of the maternal ovum meet and fuse together. It is clearly irrational to assume an " eternal life without md " for an individual phenomenon, the commencement of' which we can indicate to a moment by direct visual observation. But the unbroken chain of plasma-movements which we comprise under the title of a man's " soul " is just such an individual phenomenon. This chain of molecular movements begins at the moment when the paternal nucleus fuses with the maternal. From the stem-nucleus thus produced it is transmitted, in the repeated segmentation, to all the similar cells of the germinal layer. When these blastodermic cells grow into the two primary germinal layers of the gastrula, the first division of labour in the cells takes place ; and this continues when the various tissues arise from them. Later, in man and the higher animals, it is only the central nervecells which are the primary organs of psychic life. We often hear it said that the belief in immortality is an indispensable foundation of religion and morality, like the belief in a personal God. This opinion is totally opposed to the facts of history. In any case it is clear that all that is "personal " must be transitory, a mere passing phenomenal form in the course of the evolutionary process. Hence it is a curious error to speak, as Weismann does, of the immortality of the unicellular beings. The unicellular protists are transitory individuals just as truly as the multicellular organisms, to which man belongs. Ii is true that our human soul is often regarded as something unique, and credited with peculiar powers that are not found in the other vertebrates. But an impartial study of comparative psychology completely disposes o\ this illusion. We shall see that the special Organs o( man's mental life are evolved in just the same way as those of other vertebrates. The great importance of the process of impregnation in answering these and other cardinal questions is quite clear. It is true that conception has never been studied microscopically in all its details in the human case — notwithstanding its occurrence animals. The stem-cell which is produced, and with which every man begins his career, cannot be distinguished in appearance from those of other mammals, such as the hare (Fig. p,o). In the case of man, also, this stem-cell differs materially from the original ovum, both in regard to form (morphologically), in regard to material composition (chemically), and in regard to vital properties (physiologically). It comes partly from the father and partly from the mother. Hence it is nol Fig. 30.— Stem-cell of a hare, magnified joo times. In the centre of the granular protoplasm of the fertilised ovum ( </ j is seen the little, bright stem-nucleus. . is the ovolemma, with a mucous membrane ( h). s are dead spermatozoa. from both parents.1 The vital movements of each of these cells form a sum of mechanical processes which in the last analysis are due to movements of the smallest vital parts, or the molecules of the living substance. If we agree to call this active substance plasson and its molecules plastidules, we may say that the individual physiological character of each of these cells is due to its molecular plastidule-movement. Hence, the plastidulemovement of the cytula is the resultant of the combined plastidule-nwvenients of the female ovum and the male sperm-cell. If we take the latter two to be the side-lines in a parallelogram of forces, the plastidule-movement of the stem-cell is its diagonal. I have shown, in my essay on "The Perigenesisof the Plastidule, or the Wave-movement of the Vital Particles " (1876), the importance of this view for a mechanical explanation of the elementary processes of evolution. 1 The plasson of the stem-cell or cytula may, from the anatomical point of view, be regarded as homogeneous and structureless, like that of the monera. This is not inconsistent with our hypothetical ascription to the plastidules (or molecules of the plasson) of a complex molecular structure. The complexity of this is the greater in proportion to the complexity of the organism that is developed from it and the length of the chain of its ancestry, or to the multitude of antecedent processes of heredity and adaptation. First changes after the impregnation of the ovum. The original or palingenetic form of segmentation. Nature of the segmentation-process. Repeated cleavage of the stem-cell. Formation of several segmentation spheres or blastomeres. Mulberry-like structure, or morula. Blastula. Germinal membrane or blastoderm. Folding of the blastula. Formation of the gastrula. Depula, transition from the blastula to the gastrula. Primitive gut and primitive mouth. The two primary germinal layers : ectoderm (epiblast) and entoderm (hypoblast). Differences between their cells. Similarity of the original gastrulation in the most distant groups of the animal world. The gastrulation of the amphioxus ; transition from the primary (uni-axial) to the secondary (bi-lateral or tri-axial) form of the gastrula. Bending of the chief axis. Flattening of the hinder side, large growth of the fore-side. The secondary, modified, or cenogenctic forms of gastrulation. Significance and unequal distribution of the yelk. Total and partial cleavage. Holoblastie and meroblastie ova. Disc-like cleavage and disc-gastrula : fishes, reptiles, birds. Superficial cleavage and globular gastrula : articulata. Permanent two-layered structure of the lower animals. The two-layered primitive stem-form : gastrffia. Homology of the two primary germinal layers. There is a substantial agreement throughout the animal world in the first changes which follow the impregnation of the ovum and the formation of the stem-cell ; they begin in all cases with the segmentation of the ovum and the formation of the germinal layers. The only exception is found in the protozoa, the very lowest and simplest forms of animal life ; these remain unicellular throughout life. To this group belong the amoebae, gregarina^, rhizopods, infusoria, etc. As their whole organism consists of a single cell, they can never form germinal layers, or definite strata of cells. But all the other animals — all the tissue-forming animals, or 1 Cf. E. Ray-Lankester's essays " On the Primitive Cell-layers 01 the Embryo as the Basis of Genealogical Classification of the Animals " (Ann. Mag. Nat. Hist., vol. xi., 1873) and '• Notes on the Embryology and Classification of the Animal Kingdom " ( Quarterly Journal of Microscopic Science, vol. xvii. , 1877), and Francis Balfour's Manual of Comparative Embryology, and " On the Structure and Homology of the Germinal Layers of the Embryo " ( Quart. Journal of Micros. Science. 1SS0). THE GAST8AVA THEORY metazoa, as we call them, in contradistinction to the protozoa — construct real germinal layers by the repeated cleavage of the impregnated ovum. This we find in the lower cnidaria and worms, as well as in the more highly-developed molluscs, echinoderms, articulates, and vertebrates. In all these metazoa, or multicellular animals, the chief embryonic processes are substantially alike, although they often seem to a superficial observer to differ considerably. The stem-cell that proceeds from the impregnated ovum always passes by repeated fission into a number of simple cells. These cells are all direct descendants of the stem-cell, and are, for reasons we shall see presently, called segmentation-cells, or segmentation-spheres (blaslomera or segmentella). The repeated cleavage of the stem-cell, which gives rise to these segmentation-spheres, has long been known as •• segmentation." Sooner or later the segmentation-cells join together to form a round (at first, globular) embryonal sphere (bias tula J; they then form into two very different groups, and arrange themselves in two separate strata — the two primary germinal layers. These enclose a digestive cavity, the primitive gut, with an opening, the primitive mouth. We give the name of the gastrula to the important embryonic form that has these primitive organs, and the name of gastrulation to the formation o( it. This ontogenetic process has a very great significance, and is the real starting-point of the construction of the multicellular animal body. The fundamental embryonic processes of the cleavage of the ovum and the formation of the germinal lavers have been very thoroughly studied in the last thirty years, and their real significance has been appreciated. They present a striking variety in the different groups, and it was no light task to prove their essential identity in the whole animal world. But since I formulated the gastraja theory in 1S72, and afterwards (1875) reduced all the various forms of segmentation and gastrulation to one fundamental type, their identity may be said to have been established. We have thus mastered the law of unity which governs the first embryonic processes in all the animals. Man is like all the other higher animals, especially the apes, in regard to these earliest and most important processes. As the human embryo does not essentially differ, even at a much later stage of development — when we already perceive the cerebral lobes, the eyes, ears, gill-arches, etc. — from the similar forms of the other higher mammals (cf. Plate XIII., first row), we may confidently assume that they agree in the earliest embryonic processes, segmentation and formation of germinal layers. This has not yet, it is true, been established by observation. We have never yet had occasion to dissect a woman immediately after impregnation and examine the stem-cell or the segmentation-cells in her oviduct. However, as the earliest human embryos (in the form of embryonal spheres) we have examined, and the later and more developed forms, agree with those of the hare, dog, and other higher mammals, no reasonable man will doubt but that the segmentation and formation of layers are the same in both cases, as Figs. 12-17 on Plate H- represent. But the special form of segmentation and layer-formation which we find in the mammal is by no means the original, simple, palingenetic form. It has been much modified and cenogenetically altered by a very complex adaptation to embryonic conditions. We cannot, therefore, understand it altogether in itself. In order to do this, we have to make a comparative study of segmentation and layer-formation in the animal world ; and we have especially to seek the original, palingenetic form from which the modified cenogenetic form has gradually been developed. This original palingenetic form ot segmentation and layer-formation is found to-day in only one case in the vertebrate-stem to which man belongs — the lowest and oldest member of the stem, the wonderful lancelet or ampbioxus (cf. Chapters XVI. and XVII., and Plates XVIII. and XIX.). But we find a precisely similar palingenetic form of embryonic development in the case of many of the invertebrate animals, as, for instance, the remarkable ascidia, the pond-snail (limnceusj, the arrow-worm (sagit/a), and many of the echinoderms and cnidaria, such as the ordinary star-fish and sea-urchin, many of the medusae and corals, and the simpler sponges ' olyiithus ,. We may take as an illustration the palingenetic segmentation and germinal layer-formation in an eight-fold insular coral, which I discovered in the Red Sea, and described in my Arabische Korallen as monoxenta Darwinti. The impregnated ovum of this coral (Fig. 31 A, B) first splits into two equal cells (C). First, the nucleus of the Stem-cell and the dependent centrosoma divide into two halves. These recede from and repel each other, and act as centres of attraction on the surrounding protoplasm ; in consequence of this, the protoplasm is constricted by a circular furrow, and, in turn, divides into two halves. Each of the two segmentation-cells thus produced splits in the same way into two equal cells, and, in fact, the plane of cleavage of the latter two lies vertically on that of the first (Fig. D). The four familiar segmentation-cells (grand-daughters of the stem-cell) lie in one plane. Now, however, each of them sub-divides into two equal halves, the cleavage of the nucleus again preceding that of the surrounding protoplasm. The eight cells which thus arise break into sixteen, these into thirty-two, and then (each being constantly halved) into sixtylour, 128, and soon.1 The final result of this repeated cleavage is the formation of a globular cluster of similar segmentationcells, which we call the mulberry-formation or morula. The cells are thickly pressed together like the parts of a mulberry or blackberry, and this gives a lumpy appearance to the surface of the sphere (Fig. E). [Cf. also Fig. 3 on Plate II.]2 When the cleavage is thus ended, the mulberry-like mass changes into a hollow globular sphere. Watery fluid or jelly gathers inside the globule ; the segmentation cells are ' Tin' number of blastomeres or segmentation-cells increases geometrically in the original gastrulation, or the purest palingenetic form of cleavage. However, in different archiblastic animals the number reaches a different height, so that the morula, and also the blastula, may consist sometimes of thirty-two, sometimes of sixty-four, and sometimes ol 128, or more, rolls. •' The segmentation-cells which make up the morula after tin- close oi the palingenetic cleavage seem usually to in- quite similar, ami to present no morphological differences as to size, form, and composition. That, however, does not prevent them from differentiating into animal and vegetative rolls even during the cleavage, as Figs. 2 and ,', on Plate II. indicate. Fig. 31.— Gastrulation Of a <ZQVa\(monoxenia Darminii). A, B, stemcell (cytula) or impregnated ovum. In Fig-. A (immediately after impregnation} the nucleus is invisible. In Fig. B (a little later) it is quite clear. C two segmentation-cells. D four segmentation-cells. E mulberry-formation (morula). F embryonal sphere (blastula). G embryonal sphere (transverse section). H tufted embryo (depula, or hollowed embryonal sphere) — transverse section. I gastrula — longitudinal section. K gastrula, or cup-sphere, external appearance. , loosened, and all rise to the surface. There they are flattened by mutual pressure, and assume the shape of truncated pyramids, and arrange themselves side by side in one regular layer (Figs. F, G). This layer of colls is called the germinal membrane (blastoderm) ; the homogeneous cells which compose its simple structure are called blastodermic cells f cclluUv blastoderm iac 1 ; and the whole hollow sphere, the walls of which are made of the preceding, is called the bias tula, or blastosphere (or vesicula b/astoclerin tat).1 In the case of our coral, and of many other lower forms of animal life, the young embryo begins at once to move independently and swim about in the water. A fine, long, thread-like process, a sort of whip or lash, grows out of each blastodermic cell, and this independently executes vibratory movements, slow at first, but quicker after a time (Fig. F). In this way each blastodermic cell becomes a ciliated cell. The combined force of all these vibrating lashes causes the whole blastula to move about in a rotatory fashion. In many other animals, especially those in which the embryo developes within enclosed membranes, the vibratory ciliated cells are only formed at a later stage, or even not formed at all. The blastosphere may grow and expand by the blastodermic cells (at the surface of the sphere) dividing and increasing, and more fluid is secreted in the internal cavity. There are still to-day some organisms that remain throughout life at the structural stage of the blastula — hollow vesicles that swim about bv a ciliary movement in the water, the wall of which is composed of a single layer of cells, such as the volvox, the magosphsera, synura, etc. We shall speak further oi the great phvlogenetie significance of the fact in the nineteenth Chapter. A very important and remarkable process now follows — namely, the curving of the blastula (invaginatio blastula, Fig. II). The vesicle with a single layer of cells for wall is 1 Tin/ blastula of the lower animals must not be confused with the very different blastula of the mammal, which is properly called the gastrocystis or blastocyst is. This Mitogenetic gastrocystis and the palingenetic blastula are sometimes very wrongly comprised under the common name ol blastula or vesicula blastodermica. converted into a cup with a wall of two layers of cells (cf. Figs. G, H, I). A certain spot at the surface of the sphere is flattened, and then bent inward. This depression sinks deeper and deeper, growing at the cost of the internal cavity. The latter decreases as the hollows deepen. At last the internal cavity disappears altogether, the inner side of the blastoderm (that which lines the depression) coming to lie close on the outer side. At the same time, the cells of the two sections assume different sizes and shapes ; the inner cells are more round and the outer more oval (Fig. I). In this way the embryo takes the form of a cup or jar-shaped body, with a wall made up of two layers of cells, the inner cavity of which opens to the outside at one end (the spot where the depression was originally formed). We call this very important and interesting embryonic form the "cup-embryo" or "cup-larva" {gastrula, Fig. 31, I longitudinal section, K external view).1 I have in my Natural History of Creation given the name of " tufted embryo " or depula to the remarkable intermediate form which appears at the passage of the blastula into the gastrula : " In this intermediate stage there are two cavities in the embryo — the original cavity fblastocoelj which is disappearing, and the primitive gut-cavity (progaster ) which is forming. The one grows at the expense of the other ; though in many of the other metazoa a relic of the inner cavity remains, and may form a 'false body-cavity' (pseiidocccl J. This is sometimes rather large, and is often called the ' primary body-cavity ' of the metazoa, in opposition to the ' secondary body-cavity,' or enteroccel, which developes afterwards out of the primitive gut in the vertebrates " (cf. Chapter X.). I regard the gastrula as the most important and significant embryonic form in the animal world. In all real animals (that is, excluding the unicellular protists) the segmentation 1 I expounded the idea of the gastrula in my monograph on the sponges in 1872. I already laid stress on " the extreme importance of the gastrula in the general phytogeny of the animal kingdom ": "the fact that this larva-form is found in the most different animal stems has, in my opinion, a significance that it is impossible to exaggerate, and gives a clear proof of the common origin oi' all from the gfastrsea." oi the ovum produces either a pure, primitive, palingenetic gastrula (Fig. 3 i I, K) or an equally instructive cenogenetic form, which has been developed in time from the first, and can immediately he reduced to it. It is certainly a fact of the greatest interest and instructiveness that animals of the most different stems — vertebrates and tunicates, molluscs and articulates, echinoderms and annelids, cnidaria and sponges — proceed from one and the same embryonic form. In illustration I give a few pure gastrula forms from various groups of animals (Figs. 32-37, explanation given above). In view of this extraordinary significance of the gastrula, we must make a very careful study of its original structure. As a rule, the typical gastrula is very small, being invisible to the naked eye, or at the most only visible as a fine point under very favourable conditions, and measuring generally ^u to T\ of a millimetre (less frequently \ to 1, or even more) in diameter. In shape it is usually like a roundish drinkingcup. Sometimes it is rather oval, at other times more ellipsoid or spindle-shaped ; in some cases it is half globular, or even almost globular, and in others lengthened out, or almost cylindrical. The geometrical type-form — a single axis with two different poles — is very characteristic. This axis is the long axis or chief axis of the subsequent uni-axial body; one pole is the mouth-pole (oral pole), and the other the contra-mouthpole (aboral pole). In the bilateral animals, or higher animals with right and left similar halves to the structure, the cenogenetically modified gastrula usually assumes a bilateral (and tri-axial) form at an early stage (Fig. 41). The gastrula is distinguished very sharply by this uni-axial, or monaxial, form from the globular blastula and morula, in which all the axes of the body are alike. The transverse section of the primary gastrula is round. I give the name of primitive gut 1 progaster ) and primitive mouth (prostoma) to the internal cavity of the gastrula-body and its opening ; because this cavity is the first rudiment of the digestive cavity of the organism, and the opening originally served to take food into it. Naturally, the primitive gut and mouth change very considerably afterwards in the various classes of animals. In most of the cnidaria and many of the annelids (worm-like animals) they remain unchanged throughout life. But in most of the higher animals, and so in the vertebrates, only the larger central part of the later alimentary canal developes from the primitive gut ; the later mouth is a fresh development, the primitive mouth disappearing or changing into the anus. We must therefore distinguish carefully between the primitive gut and mouth oi' the gastrula and the later alimentary canal and mouth of the fully developed vertebrate.1 The two layers o\ cells which line the gut-cavity and compose its wall arc o( extreme importance. These two layers, which are the sole builders of the whole organism, arc no other than the two primary germinal layers, or the primitive germ-layers fblastophyllaj. I have spoken in the introductory section (Chapter III.) of their radical importance. The outer stratum is the skin-layer, or ectoderm (Figs. 32-37); the inner stratum is the gut-layer, or entoderm (/). The former is often also called the ectoblast, or epiblast, and the latter the endoblast, or hypoblast. From these two primary germinal layers alone is developed the entire organism of all the metazoa or multicellular animals. The skin-layer forms the external skin, the gut-layer forms the internal skin or lining of the body. Between these two germinal layers are afterwards developed the middle germinal layer (mesoderma) and the body-cavity fcoelosomaj filled with blood or lymph. The two primary germinal layers were first distinguished by Pander in 1S1 7 in the incubated chick, the outer being called the serous, and the inner the mucous, layer (p. ^9). But their full significance was first realised by Baer, who called the first the animal, and the second the vegetative, layer in his classical work on embryology (1828). These names are suitable enough in the sense that the animal organs of sensation — the skin, nerves, and sense-organs — are formed chieflv (if not exclusively) from the outer layer; and the vegetal organs of nutrition and reproduction, especially the alimentary canal and the blood-vessels, are formed chiefly from the inner layer. Professor K. Ray-Lankester suggested three years afterwards (1875) the name archenteron for the primitive gut, and blastopOTUS for the primitive mouth. An interesting theory of the mouth has lately been put forward by Daniele Rosa {of Moilena) in his essay, "II canale neurenterico ed il blastopore anale" (BoUetino Z00U di Torino. \o. I46, 1903). pointed out that in many of the lower zoophyta, especially the medusae, the whole body consists throughout life of these two primary germinal layers. Soon afterwards (1853) Allman introduced the names which have come into genera use ; he called the outer layer the ectoderm (" outer-skin "), and the inner the entoderm (" inner-skin "). But in 1867 it was shown, particularly by Kowalevsky, from comparative observation, that even in invertebrates, also, of the most different classes — annelids, molluscs, echinoderms, and articulates — the body is developed out of the same two longitudinal section through the axis, g primitive gut-cavity, 0 primitive mouthaperture, i inner cell-layer (entoderm, endoblast, gut-layer), e external celllayer (outer germinal layer, ectoderm, eetoblast, or skin-layer). primary layers. Finally, I discovered them (1872) in the lowest tissue-forming animals, the sponges, and proved in my gastrasa theory that these marginal layers must be regarded as identical or homologous throughout the animal world, from the sponges and corals to the insects and vertebrates, including man. This fundamental " homology of the primary germinal layers and the primitive gut " has been confirmed during the last thirty years by the careful research of many able observers, and is now pretty generally admitted for the whole of the metazoa. germinal layers show appreciable differences even in the gastrula stage. Generally (if not always) the cells of the skin-layer or ectoderm (Figs. 38c, 390) are the smaller, more numerous, and clearer; while the cells of the gut-layer, or entoderm (/), are larger, less numerous, and darker. The protoplasm of the ectoderm cells is clearer and firmer than the thicker and softer cell-matter of the entoderm-cells ; the latter are, as a rule, much richer in yelk-granules (albumen and fatty particles) than the former. Also the cells of the gut-layer have, as a rule, a stronger affinity for colouring matter, and take on a tinge in a solution of carmine, aniline, etc., more quickly and appreciably than the cells of the skinlaver. The nuclei of the entoderm-cells are usually roundish, while those of the ectoderm-cells are oval. These physical, chemical, and morphological differences in the two germinal layers, corresponding to their physiological contrast, are of interest as showing us the first and oldest process of differentiation in the animal body. The skin-laver (blastoderm), which forms the wall of the globular blastula (Fig. 31 F, G), consists o\ a single stratum of homogeneous cells. These blastodermic cells are at first very regular and of similar construction, and exactly alike in si/e, shape, and texture. They are usually flattened by mutual pressure, and very often strictly hexagonal. They make the first tissue of the meta/.oon-organism, a simple cellpavement or epithelium. The homogeneity of these cells disappears sooner or later during the curving of the blastosphere. The cells which form its inner concave part (the subsequent entoderm) assume, as a rule, during the very process of folding (Fig. 31 1 1 ), different features from those which constitute the outer convex part (the subsequent ectoderm). When the folding-process is complete, very striking histological differences between the cells of the two layers are found (Fig. 39). The tiny, light ectoderm-cells (e) are sharplv distinguished from the larger and darker entodermcells ' i ,. Frequently this differentiation of the cell-forms sets in at a verv early stage, during the segmentation-process, and is already very appreciable in the blastula. We have, up to the present, only considered that form of segmentation and gastrulation which, for many and weighty reasons, we may regard as the original, primordial, or palingenetic form. We might call it " equal " or homogeneous segmentation, because the divided cells retain a resemblance to each other at first (and often until the formation of the blastoderm). We give the name of the " bell-gastrula," or archigastrula, to the gastrula that succeeds it. In just the same form as in the coral we considered ( monoxenia, Fig. 31), we find it in the lowest zoophyta, the gastrophysema (Fig. 32), and the simplest sponges (olynthus, Fig. 38) ; also in many of the medusa; and hydrapolyps, lower types of worms of various classes (brachiopod, arrow-worm, Fig. 33), tunicates (ascidia, Plate XVIII., Figs. 1-4), many of the echinoderms (Fig. 34), lower articulates (Fig. 35), and molluscs (Fig. 36), and, finally, in a slightly modified form, in the lowest vertebrate (the amphioxus, Fig. 37 ; Plate XVIII., Figs. 5-10). The gastrulation of the amphioxus is especially interesting because this lowest and oldest of all the vertebrates is of the highest significance for the phylogeny of the vertebrate stem, and therefore for our anthropogeny (compare Chapters XVI. and XVII.), Just as the comparative anatomy of the vertebrates deduces the most elaborate features in the structures of the various classes by divergent development from this simple primitive vertebrate, so comparative ontogeny traces the various secondary forms of vertebrate gastrulation to the simple, primary formation of the germinal layers in the amphioxus. Although this formation, as distinguished from the cenogenetic modifications of the vertebrate, may on the whole be regarded as palingenetic, it is nevertheless different in some features from the quite primitive gastrulation such as we have, tor instance, in the numoxenia (Fig. 31) and t he sagitta. From Hatschek's classical work (1SS1) it is clear that both kinds o( colls in the germinal layers of the amphioxus, and many other animals, show a diversity of features very early in the process of segmentation. Only the first four segmentation-cells, which are divided by two vertical planes of cleavage cutting- at a right angle, are homogeneous ( Plate XL, Fig. 8). The third, horizontal plane o\ cleavage lies, not on the equator of the ovum, but a little above it, so as to divide the four blastomeres into unequal halves — four smaller ones above and four larger below; the Fig. 40. Gastrulation of the amphioxus, from Hatschek (vertical section through the axis of the ovum). A, />', C three stages in the formation of the blastula ; />, £ curving of the blastula ; F complete gastrula. /; segmentation-cavity, g primitive gfut-cavity. former constitute the animal, and the latter the vegetal, hemisphere. Hatschek rightly observes that the segmentation ot the ovum in the amphioxus is not strictly equal, but almost equal, and approaches the unequal. The difference in size between the two groups of cells continues to be very noticeable in the further course of the segmentation ; the smaller animal cells o\ the upper hemisphere divide more quickly than the larger vegetal cells of the lower (Fig. 40 A, />). Hence the blastoderm, which forms the singlelayer wall o\ the globular blastula at the end of the cleavageprocess, does not consist ot homogeneous cells of equal size, as in the sagitta and the monoxenia ; the cells of the upper half of the blastoderm (the mother-cells of the ectoderm) are more numerous and smaller, and the cells of the lower half (the mother-cells of the entoderm) less numerous and larger. Moreover, the segmentation-cavity of the blastula (Fig. 40 C, h) is not quite globular, but forms a flattened spheroid with unequal poles of its verticle axis. While the blastula is being folded into a cup at the vegetal pole of its axis, the difference in the size of the blastodermic cells increases (Fig. 40 D, E); it is most conspicuous when the invagination is complete and the segmentationcavity has disappeared (Fig. 40 F). The larger vegetal cells of the entoderm are richer in granules, and so darker than the smaller and lighter animal cells of the ectoderm. But the unequal gastrulation of the amphioxus diverges from the typical equal cleavage of the sagitta, the monoxenia (Fig. 31), and the olyntluts (Fig. 38), not only by this early (or cenogenetically premature) differentiation of the blastodermic cells, but also in another important particular. The pure archigastrula of the latter forms is uni-axial, and it is round in its whole length in transverse section. The vegetal pole of the vertical axis is just in the centre of the primitive mouth. This is not the case in the gastrula of the amphioxus. During the folding of the blastula the ideal axis is already bent on one side, the growth of the blastoderm (or the increase of its cells) being brisker on one side than on the other; the side that grows more quickly, and so is more curved (Fig. 41 v), will be the anterior or belly-side, the opposite, flatter side will form the back (d). The primitive mouth, which at first, in the typical archigastrula, lay at the vegetal pole of the main axis, is forced away to the dorsal side ; and whereas its two lips lay at first in a plane at right angles to the chief axis, they are now so far thrust aside that their plane cuts the axis at a sharp angle. The dorsal lip is therefore the upper and more forward, the ventral lip the lower and hinder. In the latter, at the ventral passage of the entoderm into the ectoderm, there lie side by side a pair of very large cells, one to the right and one to the left (Fig. 41 p) : these arc the important polar cells of the primitive mouth, or "the primitive cells of the mesoderm." In consequence of these considerable variations arising in the course of the gastrulation, the primitive uni-axial form of the archigastrula in the amphioxus has already become tri-axial, and thus the two-sidedness, or bilateral symmetry, of the vertebrate body has already been determined. The vertical middle plane (or arrow-plane) passes between the two polar cells of the prostoma, and goes the whole length of the body, dividing it into two equal halves or "antimera," right and left. The primitive mouth lies at the further and hinder end, a little above the anti-oral pole of the long axis. The arrow-axis, or dorso-ventral axis, lies vertically to this chief axis on the middle plane, joining the central lines of the flat dorsal side and the convex ventral side. The horizontal transverse axis, or lateral axis, vertical to the two (unequally polar) axes, is equi-polar, and crosses diagonally from right to left. Thus, the gastrula of the amphioxus alreadv exhibits the characteristic two-sidedness of the vertebrate body, and this has been transmitted from the amphioxus to all the other modified gastrula-forms of the vertebrate stem. With these the original embryonic process has been gradually more or less altered in the course of millions of years by adaptation to new conditions of development. Both the segmentation of the ovum and the subsequent gastrulation have in this way been considerably changed. In fact, these variations have become so great in the course of time that the segmentation was not rightly understood in most animals, and the gastrula was unrecognised. It was not until I had made an extensive comparative study, lasting a considerable time (in the years 1866-75), in animals of the most diverse classes, that I succeeded in showing the same common typical process in these apparently very different forms of gastrulation, and tracing them all to one original form. I regard all those that diverge from the primary palingenetic gastrulation as secondary, modified, and cenogenetic. The more or less divergent form of gastrula that is produced may be called a secondary, modified gastrula, or a metagastrula. Among the many and varied cenogenetic forms of segmentation and gastrulation I distinguish three chief types: 1, unequal segmentation (Plate II., Figs. 7-17); 2, discoid segmentation (Plate III., Figs. 18-24); an^ 3i superficial segmentation (Plate III., Figs. 25-30). From the unequal cleavage we have the tufted foetus ( ainphigaxtru/a, Plate II., Figs. 11 and 17); the discoid cleavage produces the disk-shaped gastrula ( discogastntta, Plate III., Fig. 24) ; and the superficial produces the globular gastrula ( perigastrula, Plate III., Fig. 29). In the vertebrates, with which we are chief!)' concerned, the last-named form is not found at all ; on the other hand, it is the commonest form among the articulates (crabs, spiders, insects, etc.). Mammals and amphibia have the unequal segmentation and the tufted foetus ; so also the ganoid (scaley) and the round-mouthed fishes (the lamprey and myxine). On the other hand, most fishes, and all reptiles and birds, have the discoid segmentation and gastrula. (Cf. Table II., p. 171.) By far the most important process that determines the various cenogenetic forms of gastrulation is the change in the nutrition of the ovum and the accumulation in it of nutritive yelk. By this we understand various chemical substances (chiefly granules of albumin and fat-particles) which serve exclusively as reserve-matter or food for the embryo. As the metazoic embryo in its earlier stages of development is not yet able to obtain its food and SO build up the frame, the necessary material has to be stored up in the ovum. Hence we distinguish in the ova two chief elements — the active formative yelk (protoplasm or vitcllus format 'ivi/s 1 and the passive food-yelk (deutoplasm, or vitcllus nutritious, wrongly spoken oi as " the yelk," lecithus). In the little palingenetic ova, the segmentation of which we have already considered, the yelk-granules are so small and so regularly distributed in the protoplasm of the ovum that the even and repeated cleavage is not affected by them. But in the great majority oi the animal ova the food-yelk is more or less considerable, and is stored in a certain part of the ovum, so that even in the unfertilised ovum the "granary " can clearly be distinguished from the formative plasm. As a rule, there is then a polar differentiation of the ovum, in the sense that a chief axis can be discerned in it, and the formative yelk (with the germinal vesicle) gathers at one pole and food-yelk at the other. The first is the animal, and the second the vegetal, pole of the vertical axis of the ovum. In these " telolecithal " ova (for instance, in the cyclostoma and amphibia, Plate II., Figs. 7-11) the gastrulation then usually takes place in such a way that in the cleavage of the impregnated ovum the animal (usually the upper) half splits up more quickly than the vegetal (lower). The contractions oi the active protoplasm, which effect this continual cleavage oi the cells, meet a greater resistance in the lower vegetal half from the passive deutoplasm than in the upper animal half. Hence we find in the latter more but smaller, and in the former fewer but larger, cells. The animal cells produce the external, and the vegetal cells the internal, germinal layer. Although this unequal segmentation of the cyclostoma, ganoids, and amphibia seems at first sight to differ from the original equal segmentation (for instance, in the monoxenia, Fig. 31), they both have this in common, that the cleavage process throughout affects the whole cell ; hence Remak called it total segmentation, and the ova in question holoblastic. It is otherwise with the second chief group of ova, which he distinguished from these as meroblastic : to this class belong the familiar large eggs of birds and reptiles, and of most fishes. The inert mass of the passive food-yelk is so large in these cases that the protoplasmic contractions of the active yelk cannot effect any further cleavage. In consequence, there is only a partial segmentation. While the protoplasm in the animal section of the ovum continues briskly to divide, multiplying the nuclei, the deutoplasm in the vegetal section remains more or less undivided ; it is merely consumed as food by the forming cells. The larger the accumulation of food, the more restricted is the process of segmentation. It may, however, continue for some time (even after the gastrulation is more or less complete) in the sense that the vegetal cell-nuclei distributed in the deutoplasm slowly increase by cleavage ; as each of them is surrounded by a small quantity of protoplasm, it may afterwards appropriate a portion of the food-yelk, and thus form a real " yelk-cell " ( merocyte I. When this vegetal cell-formation continues for a long time, after the two primary germinal layers have been formed, it takes the name of the "after-segmentation " (Waldeyer). The meroblastic ova (Plate III.) are only found in the larger and more highly developed animals, and only in those whose embryo needs a longer time and richer nourishment within the foetal membranes. According as the yelk-food accumulates at the centre or the side of the ovum, we distinguish two groups of dividing ova, periblastic and discoblastic. In the periblastic the food-yelk is in the centre, enclosed inside the ovum (hence they are also called "centrolecithal " ova) : the formative yelk surrounds the food-yelk, and so suffers itself a superficial cleavage. This is found among the articulates (crabs, spiders, insects, etc., Plate III., Figs. 25-30). In the discoblastic ova the food-yelk gathers at one side, at the vegetal or lower pole of the vertical axis, while the nucleus of the ovum and the great bulk of the formative yolk lie at the upper or animal pole (hence these ova are also called " tclolethical "). In these cases the Cleavage of the ovum begins at the upper pole, and leads to the formation of a dorsal discoid embryo. This is the case with all meroblastic vertebrates, most fishes, the reptiles and birds, and the oviparous mammals (monotrema). The gastrulation of the discoblastic ova, which chiefly concerns us, otters serious difficulties to microscopic investigation and philosophic consideration. These, however, have been mastered by the comparative embryological research which has been conducted by a number of distinguished observers during the last few decades — especially the brothers Hertwig, Rabl, Kupffer, Selenka, Riickert, Goette, Rauber, etc. These thorough and careful studies, aided by the most perfect modern improvements in technical method (in tinting and dissection), have given a very welcome support to the views which I put forward in my work, On /lie Gastrula and the Segmentation of the Animal Ovum \|not translated], in 1875. As it is very important to understand these views and their phylogenetic foundation clearly, not only as regards evolution in general, but particularly in connection with the genesis of man, I will give here a brief statement o( them as far as they concern the vertebrate-stem : — vidual development must also hang together phylogenetically. 3. As the gastrulation of the amphioxus shows the original palingenetic form in its simplest features, that of the other vertebrates must have been derived from it. 5. Although the mass of the food-yelk may be very large in the ova of the discoblastic vertebrates, nevertheless in every case a blastula is developed from the morula, as in the holoblastic ova. blastula by folding, or invagination. 7. The cavity which is produced in the foetus by this folding is, in each case, the primitive gut (progaster), and its opening the primitive mouth (prostoma). 8. The food-yelk, whether large or small, is always stored in the ventral wall of the primitive gut ; the cells (called "merocvtes") which may be formed in it subsequently (bv " after-segmentation ") also belong to the inner germinal layer or endoblast, like the cells which immediately enclose the primitive gut-cavity. 9. The primitive mouth, which at first lies below at the basic pole of the vertical axis, is forced, by the growth of the yelk, backwards and then upwards, towards the dorsal side of the embryo ; the vertical axis of the primitive gut is thus gradually converted into horizontal. 10. The primitive mouth is closed sooner or later in all the vertebrates, and does not pass into the permanent mouthaperture; it rather corresponds to the "properistoma," or region of the anus. From this important point the formation of the middle germinal layer proceeds, between the two primary layers. The wide comparative studies of the scientists I have named have further shown that in the case of the discoblastic higher vertebrates (the three classes of amniotes) the primitive mouth of the embryonic disc, which was long looked for in vain, is found always, and is nothing else than the familiar " primitive groove." This is a groove that lies in the hinder dorsal surface of the discoid gastrula, and was formerly confused with the hinder part of the medullary tube. It is true that it is directly connected with this for some time (bv the canalis neurentericus, which we shall discuss later), but originally it is a totally different thing, both in structure and purport. The two parallel longitudinal swellings which enclose this slender " primitive groove" (lying on the middle line) are the right and left primitive lips. The primitive mouth, which is at first (in the holoblastic vertebrates) a small round opening, is thus altered (in consequence of the increasing accumulation of food-yelk and the resulting extension of the ventral wall oi the primitive gut) not only in position and direction, but also in shape and size. It changes first into a sickle-shaped tranverse told (the " sickle-groove "), in which we distinguish a ventral (lower) and a dorsal (upper) primitive lip. However, the broad transverse fold soon narrows, and changes into a longitudinal fold (something like a hare-slit), the right and left halves of the sickle-groove (called the "sickle-horns") being shortened, the middle part and the two halves of the dorsal upper lip being drawn forward. The latter meet subsequently in the middle line, and form the important " primitive streak." Thus gastrulation may be reduced to one and the same process in all the vertebrates. Moreover, the various forms it takes in the invertebrate metazoa can always be reduced to one of the four types of segmentation described above. In relation to the distinction between total and partial segmentation, the grouping of the various forms is as follows : — The lowest metazoa we know — namely, the lower zoophyta (sponges, simple polyps, etc.) — remain throughout life at a stage o\ development which differs little from the gastrula ; their whole body consists of two layers of cells. This is a fact o( extreme importance. We see that man, and even other vertebrates, pass quickly through a stage o( development in which they consist oi two layers, just as these lower zoophyta do throughout life. If we apply our biogenetic law to the matter, we at once reach this important conclusion : " Man and all the other animals which pass through the twolayer stage, or gastrula-form, in the course of their embryonic development, must descend from a primitive simple stem-form, the whole body of which consisted throughout life (as is the case with the lower zoophyta to-dav) merely of two cell-strata or germinal lavers." We will call this primitive stem-form, with which we shall deal more fully later on, the gastrcea — that is to sav, " primitive-gut animal." According to this gastraea theory, one organ was originally of the same morphological and physiological significance in all multicellular animals — the primitive gut ; and the two primarv germinal layers which form its wall must also be regarded as similar or homologous in all. This important homology of the primary germinal layers is proved, on the one hand, from the fact that the gastrula was originally formed in the same way in all cases — namely, by the folding of the blastula; and, on the other hand, by the fact that in everv case the same fundamental organs arise from the germinal layers. The outer or animal layer, or ectoderm, always forms the chief organs of animal life — the skin, nervous system, sense-organs, etc. ; the inner or vegetal layer, or entoderm, gives rise to the chief organs of vegetative life — the organs of nourishment, digestion, blood-formation, etc. In the lower zoophvta, whose bodv remains at the twolayer stage throughout life, the gastrajada, the simplest sponges i olynthus j, and polyps ( hydra J, these two groups of functions, animal and vegetative, are strictly divided between the two simple primary layers. Throughout life the outer or animal blastodermic layer acts simply as a covering for the body, and accomplishes its movement and sensation. The inner or vegetative laver of cells acts throughout life as a gut-epithelium, or nutritive laver of enteric cells, and often also releases the reproductive cells. The best known of these " gastrasada," or " gastrula-like animals," is the common fresh-water polyp (hydra). This simplest of all the cnidaria has, it is true, a crown of tentacles round its mouth. Also its outer germinal layer is slightly differentiated histologically. But these are secondary additions, and the inner germinal laver is a simple stratum of In all other animals, particularly the vertebrates, the gastrula is merely a brief transitional stage. Here the twolayer Stage of the embryonic development is quickly succeeded by a three-layer, and then a four-layer, stage. With the appearance of the four superimposed germinal layers we reach again a firm and steady standing-ground, from which we may follow the further, and much more difficult and complicated, course of embryonic development. Segmentation and Gastrulation. Plates II. and III. illustrate the chief differences in the ovum-segmentation and gastrulation of animals by diagrammatic sections. Plate II. shows holoblastic ova (with total segmentation) ; Plate III., meroblastic ova (or with partial segmentation). The animal half of the ova (ectoderm) is tinted grey, and the vegetal half (entoderm with food-yelk) red. The food-yelk is vertically grained. All sections are vertical and median (through the axis of the primitive gut). The letters have the same meaning throughout: c Stem-cell ( ' cytula ). f Segmentation-cells ( segmentella or blastomeres ). m Mulberrystage (morula), b Blastula. g Cup-structure (gastrula). s Segmentationcavity (blastoccelum), d Primitive gut-cavity (progasier). u Primitive mouth ( prostoma ). n food-yelk (lecithus). i gut-layer ( entodcrma ). e skin-layer ( ectoderma ). Figs. 1-6. Equal Segmentation of a lower metazoon ^///ii, ascidia). Fig. r. Stem-cell (cytula). Fig. 2. Cleavage-stage with four segmentationcells. Fig. 3. Mulberry-stage (morula). Fig. 4. Blastula. Fig. 5. The same in process of folding or invagination (depula). Fig. 6. Bell-gastrula (archigastrula). Cf. Figs. 31-40. Figs. 7-1 1. Unequal Segmentation of an amphibian (frog). Fig. 7. Stem-cell. Fig. 8. Cleavage stage with four segmentation-cells. Fig. 9. Morula. Fig. 10. Blastula. Fig. 11. Tuft-gastrula (amphigastrula). Cf. Figs. Figs. 12-17. Unequal segmentation of a mammal (hare). Fig. 12. Cytula. Fig. 13. Cleavage with two segmentation-cells (e mother-cell of the ectoderm, i mother-cell of the entoderm). Fig. 14. Cleavage-stage with four segmentation-cells. Fig. 15. Beginning of the folding of the blastula. Fig. 16. Progress of the invagination. Fig. 17. Tufted gastrula (amphigastrula), Cf. Figs. 6b-75. Figs. 18-24. Discoid segmentation of a bony fish (labrus? cottus?). Most of the food-yelk ( n ) is left out (cf. Figs. 60-65). Fi»- lS- Cytula. Fig. 19. Cleavage-stage with two cells. Fig. 20. Cleavage-stage with thirty-two cells. Fig. 21. Mulberry-stage (morula). Fig. 22. Blastula. Fig. 23. The same in process of invagination (depula). Fig. 24. Discoid gastrula (discogastrula). Cytula. Fig. 26. Cleavage-stage with eight cells (only four visible). Fig. 27. Cleavage stage with thirty-two cells. Fig. 28. Morula and blastula. Fig, 29, Spherical gastrula (perigastrula). Fig. 30. Passage of the gastrula into the nauplius embryo : the gullet-cavity has been formed in front of the primitive gut by folding from without. b. Many lower annelids (sagitta, phoronis, many nematoda, etc. , terebratula, argiope, pisidium). blastula blastula (Plate III., Fig. 22).(Plate III., Fig. jS). Aroundishsphere, A closed sphere ; the smaller liemi- one layer of cells sphere consisting encloses the whole of segmentation- of the central foodcells and the larger yelk ; all the nuclei of food-velk. have been driven Primitive gut cavity full of undifilled with undi- vided food - yelk, vided food -yelk. Primitive gut suFlat germinal disc, perficial. (Only the tir>t row [Sagitta] shows the original palingenetic rhythm of the segmentation in regular geometrical progression. All the other rows show dary, cenogenetic modifications, c— Stem-cell, s = Segmentationcells, e Ectoderm-cells, i : Entoderm-cells.) Phylogenetic unity of the vertebrate-stem. Ontogenetic unity of its gastrulation. Historical relations of holoblastic and meroblastic vertebrates. Unequal segmentation of the ovum and amphigastrula of the amphibia (tailless frogs and tailed salamanders). Their segmentation-cavity (blastocoel) and primitive-gut cavity (Rusconic gastric cavity). Derivation of partial from total segmentation. Discoblastic vertebrates, with germinal disc (discoid gastrula). Deep-sea bony fishes with small and shark with large food-yelk. Epigastrula (or narrow-mouthed discoid gastrula) of the amniota. The hen's <^^g and its large food-yelk. Discoid gastrulation of the sauropsida (reptiles and birds) and monotrema. The primitive groove of the amniote-embryo is the primitive mouth of their discoid gastrula. Phylogenetic disappearance of the food-yelk in the mammal. Oviparous and viviparous mammals. Gastrulation of the opossum and the hare. Superficial segmentation of the articulata. The remarkable processes of gastrulation, ovum-segmentation, and formation of germinal layers present a most conspicuous variety. There is to-day only the lowest of the vertebrates, the amphioxus, that exhibits the original form of those processes, or the palingenetic gastrulation which we have considered in the preceding Chapter, and which culminates in the formation of the archigastrula (Fig. 40). In all other extant vertebrates these fundamental processes have been more or less modified by adaptation to the conditions of embryonic development (especially by changes in the foodyelk) ; they exhibit various cenogenetic forms of the formation of germinal layers, and thus develop by means of a metagastrula. However, the different classes vary considerably from each other. In order to grasp the unity that underlies the manifold differences in these phenomena and their historical connection, it is necessary to bear in mind always the unity of the vertebrate-stem. This "phylogenetic unity," which I systematically developed in my Generelle Morphologie THE GASTRULATION OF THE VERTEBRATE 175 in 1866, is now generally admitted. All impartial zoologists agree to-day that all the vertebrates, from the amphioxus and the fishes to the ape and man, descend from a common ancestor, "the primitive vertebrate." Hence the ontogenetic processes, by which each individual vertebrate is developed, must also be capable of being reduced to one common type ol embryonic development ; and this primitive type is most certainly exhibited to-day by the amphioxus. It must, therefore, be our next task to make a comparative study of the various forms of vertebrate gastrulation, and trace them phylogenetically to that of the lancelet. Broadly speaking, they fall first into two groups : the older cyclostoma, the earliest fishes, most of the amphibia, and the viviparous mammals, have holoblastic ova with total, unequal segmentation ; while the younger cyclostoma, most of the fishes, ccecilia, reptiles, birds, and monotrema, have mcroblastic ova, with partial discoid segmentation. A closer study oi them shows, however, that these two groups do not present a natural unity, and that the historical relations between their several divisions are very complicated. In order to understand them properly, we must first consider the various modifications of gastrulation in these classes. We may begin with that of the amphibia. The most suitable and most available object of study in this class are the eggs of our indigenous amphibia, the tailless frogs and toads, and the tailed salamander. In spring they are to be found in clusters in every pond, and careful examination of the ova with a lens is sufficient to show at least the external features of the segmentation. In order to understand the whole process rightly and follow the formation of the germinal layers and the gastrula, the ova of the frog and salamander must be carefully hardened ; then the thinnest possible sections must be made of the hardened ova with the microtome, and the tinted sections must be very closely compared under a powerful microscope. The ova of the frog or toad are globular in shape, about two millimetres in diameter, and are clustered in jellylike masses, which are lumped together in the case of the frog, but form long strings in the case of the toad. When we examine the opaque, grey, brown, or blackish ova closely, we find that the upper half is darker than the lower. The middle of the upper half is in many species black, while the middle of the lower half is white.1 In this way we get a definite axis of the ovum with two poles. To give a clear (4 animal and 4 vegetative). E twelve cells (8 animal and 4 vegetative). /"sixteen cells (8 animal and 8 vegetative). G twenty-tour cells (10 animal and 8 vegetative). H thirty-two cells. / forty-eight cells. A' sixty-tour cells. L ninety-six cells. .1/ 160 cells ( 128 animal and ,}2 vegetative). idea of the segmentation of this ovum, it is best to compare it with a globe on the surface of which are marked the various parallels of longitude and latitude. The superficial dividing 1 The colouring of the eggs of the amphibia is caused by the accumulation of dark-colouring matter at the animal pole of the ovum. In consequence of this, the animal cells of the ectoderm are darker than the vegetable cells of the entoderm. We find the reverse of this in the case of most animals, the protoplasm of the entoderm cells being usually darker and coarser-grained. lines between the different cells, which come from the repeated segmentation of the ovum, look like deep furrows on the surface, and hence the whole process has been given the name of furcation. In reality, however, this "segmentation," which was formerly regarded as a very mysterious process, is nothing but the familiar, repeated cell-segmentation. Hence also the segmentation-cells which result from it (the segmentella or blastomeres) are real cells. The unequal segmentation which we observe in the ovum of the amphibia has the special feature of beginning at the upper and darker pole (the north pole of the terrestrial globe in our illustration), and slowly advances towards the lower and brighter pole (the south pole). Also the upper and darker hemisphere remains in this position throughout the course oi the segmentation, and its cells multiply much more briskly. Hence the cells of the lower hemisphere are found to be larger and less numerous. The cleavage of the stemcell (Fig. 42 A) begins with the formation of a complete meridian furrow, which starts from the north pole and reaches to the south ( B ). An hour later a second meridian furrow arises in the same way, and this cuts the first at a right angle (Fig. 42 C ). The ovum is thus divided into four equal parts. Each of these four " segmentation-cells " has an upper and darker and a lower brighter half. A few hours later a third furrow appears, vertically to the first two 1 Fig. 42 D). This circular furrow is usually, but improperly, called the "equatorial furrow"; it lies to the north of the equator, and is more like the tropic of cancer. The globular germ now consists of eight cells, four smaller ones above (northern) and four larger ones below (southern). Next, each of the four upper ones divides into two halves by a meridian cleavage beginning from the north pole, so that we now have eight above and four below (Fig. 42 E). Later, the four new meridian divisions extend gradually to the lower cells, and the number rises from twelve to sixteen (F). Then a second circular furrow appears, parallel to the first, and nearer to the north pole, so that we may compare it to the north polar circle. In this way we get twenty-four segmentation-cells — sixteen upper, smaller, and darker ones, and eight smaller and brighter ones below ( G). Soon, however, the latter also sub-divide into sixteen, a third or "meridian of latitude " appearing, this time in the southern hemisphere: this makes thirty-two cells altogether ( ' H ). Then eight new meridian lines are formed at the north pole, and these proceed to divide, first the darker cells above and afterwards the lighter southern cells, and finally reach the south pole. In this way we get in succession forty, forty-eight, fifty-six, and at last sixty-four cells (I, K). In the meantime, the two hemispheres differ more and more from each other. Whereas the sluggish lower hemisphere long remains at thirty-two cells, the lively northern hemisphere briskly sub-divides twice, producing first sixty-four and then 128 cells ( L, M ). Thus we reach a stage in which we count on the surface of the ovum 128 small cells in the upper half and thirty-two large ones in the lower half, or 160 altogether. The dissimilarity of the two halves increases : while the northern breaks up into a great number of small cells, the southern consists of a much smaller number of larger cells. Finally, the dark cells of the upper half grow almost over the surface of the ovum, leaving only a small circular spot at the south pole, where the large and clear cells of the lower half are visible. This white region at the south pole corresponds, as we shall see afterwards, to the primitive mouth of the gastrula. The whole mass of the inner and larger and clearer cells (including the white polar region) belongs to the entoderm or ventral layer. The outer envelope of dark smaller cells forms the ectoderm or skin layer. The repeated segmentation which can thus easily be followed on the surface of the ovum is not confined to the surface, but extends to the whole interior. Thus, the cells divide in planes which correspond pretty closely to concentric planes of the spherical body : more quickly in the upper and more slowly in the lower half. In the meantime, a large cavity, full of fluid, has been formed within the globular body — the segmentation-cavity or embryonic-cavity (blastocosl, Figs. 43-46 F, and also J in the transverse sections on Plate II., Figs. 8-1 1). The first trace of this cavity is found in the middle of the upper hemisphere, where the first three successive planes of cleavage cut each other (Plate II., Fig. 8 s ). It extends considerably by progressive cleavage, Figs. 43-46.— Four vertical sections of the fertilised ovum of the toad, in four successive stages 01 development. The Letters have the same - throughout: — F segmentation-cavity. D covering of same ( D dorsal half of the embryo, P ventral half). P yelk-stopper (white round field at the lower poll-). Z yelk-cells of the entoderm (Remak's " glandular embryo"). X primitive gul cavity (progaster or Rusconian alimentary cavity). The primitive mouth (prostoma) is closed by the yelk-stopper, P. s partition between the primitive gut cavity ( X ). and the segmentation cavity ( F ). k k' il the large circular lip-border of the primitive mouth (the Rusconian anus). The line of dots between k and U indicates the earlier connection of the yelk-stopper (P) with the central mass of tin- yelk-cells (Z). In V\^. 4<> tho ovum has turned 90°, so that the back of the embryo is uppermost and the ventral side down. ( From Strieker. ) (Fig. 4.; F; Plate II., Figs. 9 s, \os). The vaulted roof of this hemispherical segmentation-cavity is formed by the smaller and dark-coloured cells of the ectoderm (Fig. 43 D ); Oil the other hand, its level floor is composed of the larger and lighter cells of the entoderm (Fig. 43 z). The globular blastula, with hollow animal half and solid vegetal half. Now a second, narrower but longer, cavity arises by bending from the lower pole, and by the falling away from each other of the white entoderm-cells (Figs. 43-46 N). This is the primitive gut-cavity or the gastric cavity of the gastrula, progaster or archenteron. It was first observed in the ovum of the amphibia by Rusconi, and so called the Rusconian alimentary cavity. In vertical section (Fig. 44) it seems to be bent in the form of a sickle, and reaches almost from the south pole to the north, forcing upwards a part of the gutcells (between the segmentation-cavity F and the dorsal covering D). The reason of the peculiar narrowness of the primitive gut-cavity here is that it is, for the most part, full of yelk-cells of the entoderm. These also stop up the whole of the wide opening of the primitive mouth, and form what is known as the "yelk-stopper," which is seen freely at the white round spot at the south pole ( P). Around it the ectoderm is much thicker, and forms the border of the primitive mouth (the properistoma ), the most important part of the embryo (Fig. 46 k, k). Soon the primitive gut-cavity stretches further and further at the expense of the segmentation-cavity ( F), until at last the latter disappears altogether. The two cavities are only separated by a thin partition (Fig. 45 s). The part of the embryo under which the primitive gut-cavity developes is the later dorsal-surface ( D ). The segmentation-cavity lies to the front and the yelk-stopper at the hinder part of the body; the thick hemispherical mass of the yelk-cells forms the ventral wall of the primitive gut. With the formation of the primitive gut our frog-embryo has reached the gastrula stage (Plate II., Fig. 11). But it is clear that this cenogenetic amphibian gastrula is very different from the real palingenetic gastrula we have considered (Figs. 32-38). In the latter, the be\\-ga.str\i\a.(archigastruhi )y the body has only one axis. The primitive gut-cavity is empty and its mouth wide open. Both the ectoderm and the entoderm consist of a single layer of cells. They lie close together, the segmentation-cavity having wholly disappeared in the process of folding. It is quite otherwise with the tufted gastrula (amphigastrula) of our amphibia (Figs. 4,1-46 ; Plate II., Fig. 1 1). In this case the segmentation-cavity ( F) remains for a long time beside the primitive gut-cavitv ( X ). Both entoderm and ectoderm consist o( several layers of cells. Finally the typical form of the whole gastrula is no longer uni-axial, but tri-axial ; owing to the eccentric development of the primitive gut-cavity, the three straight axes are determined which characterise the bilateral body of the higher animals. not difficult to reduce the Fig. 47. Embryonic vesicle of the water-salamander ( triton). fh segmentation-cavity, cte yelk-cells, ra borderzone. ( From Hertwig. \| gastrula of the amphioxus. This reduction becomes easier if, after considering the gastrulation of the tailless amphibia (frogs and toads), we glance for a moment at that of the tailed amphibia, the salamanders. In some of the latter that have only recently been carefully studied, and that are phylogenetically older, the process is much simpler and clearer than is the case with the former and longer known. Our common watersalamander (triton taeniatus) is a particularly j^ood subject for observation. Its nutritive yelk is much smaller and its formative yelk less troubled with black pigment-cells than in the case of the frog ; and its gastrulation has better retained the original palingenetic character. • It was first described byScott and Osborn (1879), and Oscar Hertwig especially made a careful study of it (1881), and rightly pointed out its great importance in helping us to understand the vertebrate development. The globular embryonic vesicle of iriton (Fig. 47) consists of loosely-aggregated, yelk-filled entodermic cells or yelkcells (dz) in the lower vegetal half; the upper, animal half encloses the hemispherical segmentation-cavity (fh), the curved roof of which is formed of two or three strata of small ectodermic cells. At the point where the latter pass into the former (at the equator of the globular vesicle) we have the border zone (rz). The folding which leads to the formation of the gastrula takes place at a spot in this border zone. This invaginationopening, the primitive mouth (Fig. 48 it), is a horizontal transverse fold at first. But it grows smaller (Fig. 49), and finally disappears. In the complete gastrula (Fig. 50) the external germinal layer ( ak ) consists of a single laver of high cylindrical cells. The internal germinal layer ( ' ik ) is, in the upper and dorsal half, also composed of a single stratum of cells ; these form the covering of the primitive gutcavity. But the floor of the latter, or the lower and ventral half, consists of several layers of large yelk-cells (dz). This part of the entoderm, which is also known as the yelkembryo ( lecithoblastus ), is much smaller in the watersalamander than in the frog. Here, again, a projection of it reaches into the primitive mouth as "yelk-stopper" (Fig. 50 p). At the thick borders of the latter begins the formation of the middle germinal layer (ink ). Fig. 4" Sagittal section of a hoodedembryo (depula) of triton 1 \ esicular embryo at the commencement of gastrulation 1. til- outer germinal layer, ik inner terminal layer, fh segmentation-cavity, ud primitive gut. 11 primitive mouth, dl and vl dorsal and ventral lips of the mouth, dz yelk-cells. 1 From Hertmig. ) stoma in 1S66 from the real fishes with which they were formerly associated, and formed of them a special class of vertebrates. The ovum-segmentation in our common river-lampreys (petromyzon fiwviatUis) was described by Max Schultze in 1856, and afterwards by Scott (1882) and Goette (1890). ning of the twentieth l'n,. 50. Sagittal section of the gastrula of the water-salamander (triton). (From Hertmig.) Letters as in Fig. 40; except — p yelk-stopper, mk beginning of the middle germinal layer. century that Bashford Dean made the important discovery in Japan that one of the oldest living fishes of the shark type (cestracion japonicus ) has the same total unequal segmentation as the amphiblastic plated fishes (ganoides).z This is particularly interesting in connection with our subject, because the few remaining survivors of this lamprey (petromyson fiuviatilis). A blastula, with wide embryonic cavity (blastocoel, bl), g incipient invagination. B depula, with advanced invagination, from the primitive mouth ( g). C gastrula. with complete primitive gut : the embryonic cavity has almost disappeared in consequence of invagination. division, which was so numerous in paleozoic times, exhibit three different types oi' gastrulation. The oldest and most conservative forms of the modern ganoids are the scaley sturgeons (sfurtones), plated fishes of great phyletic importance, ilie eggs of which are eaten as caviare ; their cleavage is not essentially different from that of the petromyzontes and amphibia. On the other hand, the most modern of the plated fishes, the beautifully scaled bony pike of the North American rivers ( lepidosteus ), approaches the osseous fishes, and is discoblastic like them. A third genus (amia) is midway between the sturgeons and the latter. The group of the lung-fishes (dipneusta or dipnoi ) is closely connected with the older ganoids. In respect of their whole organisation they are midway between the gillbreathing fishes and the lung-breathing amphibia ; they share with the former the shape of the body and limbs, and with the latter the form of the heart and lungs. Of the older dipnoi (paladipneusta) we have now only one specimen, the remarkable ceratodus of East Australia ; its amphiblastic gastrulation has been recently explained by Richard Semon (cf. Chapter XXI). That of the two modern dipneusta, of which protopterus is found in Africa and lepidosiren in America, is not materially different. (Cf. Fig. 53.) All these amphiblastic vertebrates, petromyzon and cestracion, accipenser and ceratodus, and also the salamanders and batrachia, belong to the old, conservative groups of our stem. Their unequal ovum-segmentation and gastrulation have many peculiarities in detail, but can always be reduced with comparative ease to the original cleavage and gastrulation of the lowest vertebrate, the amphioxus ; and this is little removed, as we have seen, from the very simple archigastrula of the sagitta and monoxenia (see p. 152, Figs. 31-38). All these and many other classes of animals generally agree in the circumstance that in segmentation their ovum divides into a large number of cells by repeated cleavage. All such ova have been called, after Remak, "whole-cleaving" f/10/0blasta), because their division into cells is complete or total (Plate II.). In a great many other classes of animals this is not the case, as we find (in the vertebrate stem) among the birds, reptiles, and most of the fishes ; among the insects and most of the spiders and crabs (of the articulates) ; and the cephalopods (of the molluscs). In all these animals the mature ovum, and the stem-cell that arises from it in fertilisation, Semon). A and C stage with four cells, B and D with sixteen cells. A and B are seen from above, C and D sideways. £ stage with thirtytwo cells ; .Fblastula; G gastrula in longitudinal section, fh segmentation cavity, gh primitive gut or gastric cavity. consists of two different and separate parts, which we have called formative yelk and nutritive yelk. The formative yelk (vitclhis formativus or morpholecithus ) alone consists of living protoplasm, and is the active, evolutionary, and nucleated part of the ovum ; this alone divides in segmentation, and produces the numerous cells which make up the embryo. On the other hand, the nutritive yelk (vitellus nutritivus or tropholecithus ) is merely a passive part of the contents of the ovum, a subordinate element which contains nutritive material or deutoplasm (albumin, fat, etc.). and SO represents in a sense the provision-store of the developing embryo. The latter takes a quantity of food out oi this store, and finally consumes it all. Hence the nutritive yelk is of great indirect importance in embryonic development, though it has no direct share in it. It either does not divide at all, or only later on, and does not generally consist of cells. It is sometimes large and sometimes small, but generally many times larger than the formative yelk ; and hence it is that it was formerly thought the more important of the two. As the respective significance of these two parts of the ovum is often wrongly described, it must be borne in mind that the nutritive yelk is only a secondary addition to the primary cell ; it is an inner enclosure, not an external appendage. All ova that have this independent nutritive yelk are called, after Remak, "partially-cleaving" ( meroblasta). Their segmentation is incomplete or partial (Plate III.). There are many difficulties in the way of understanding this partial segmentation and the gastrula that arises from it. We have only recently succeeded, by means of comparative research, in overcoming these difficulties, and reducing this cenogenetic form of gastrulation to the original palingenetic type. This is comparatively easy in the small meroblastic ova which contain little nutritive yelk — for instance, in the pelagic ova of a bony fish, the development of which I observed in i.S;5at Ajaccio in Corsica (Plate III., Figs. 1.S-24). I found them joined together in lumps of jelly, floating on the surface of the sea ; and as the little ovula were completely transparent, I could easily follow the development of the germ step by step. These ovula are glossy and colourless globules of little more than half a millimetre in diameter (0.64-0.66 mm). Inside a structureless, thin, but firm membrane ((/oolemma. Fig. 54 c ) we find a large, quite clear, and transparent globule of albumin (d). At both poles o\ its axis this globule has a pit-like depression. In the pit at the upper, animal pole (which is turned downwards in the floating ovum) there is a bi-convex lens composed of protoplasm, and this encloses the nucleus (k); this is the formative yelk of the stem-cell, or the germinal disk (b). From the neighbourhood of this lense-shaped nutritive yelk a very thin protoplasmic skin spreads around, and this protects the nutritive yelk, the " border-layer." At the opposite or vegetal pole of the ovum, in the lower pit, there is a clear simple globule of fat (f). The small fat-globule and the large albumin-globule together form the nutritive yelk. Only the formative yelk under- nutritive yelk, and in perfect geometrical order (cf. Plate III., Figs. 18-24; or\|ly tne formative yelk with the nearest part of the nutritive yelk (n) is given in divides into two equal segmentation-cells (Fig. 19). From these we get by repeated sub-division first four, then eight, then sixteen cells (Fig. 20). By continued cleavage we then get thirty-two cells, sixty-four, and so on. All these segmentation-cells are at first of the same size and character. Closely joined together, they form a lens-shaped mass (Plate III., Fig. 21), something like the globular mulberry - embryo of the primordial cleavage (morula, Plate II., Fig. 5). But afterwards the border cells of the lens separate from the rest, and travel into the yelk and the border-layer; they form the " embryonic border" (periblast, Fig- 55 C, p). From this lens-shaped mulberry-form there then developes a vesicular embryo (blastula), the cells of the periblast making their way centripetally underneath the lens (Plate III., Fig. 22). The regular bi-convex lens is converted into a disk like a watch-glass with thick borders. This convex cell-disk lies on the upper and less curved polar surface of the nutritive yelk like the watch-glass 011 the watch. As fluid gathers in the space between the blastoderm and the periblast, a round low cavity is formed (Fig. 22 s). This is the segmentation-cavity, corresponding to the central segmentation-cavity of the palingenetic blastula (Plate II., Fig. 4). The slightly curved floor of the lower segmentation cavity is formed by the periblast and nutritive yelk (11 J, and Fig. 5.v— Ovum-segmentation of a bony fish. (Cf. Plate III., Figs. 1S-24.) .1 first cleavage of the stem-cell (cytula). J! division of same into tour segmentation-cells (only two visible). C the germinal disk divides into the blastoderm (b) and the periblast CpJ- <i nutritive yolk, /'fat-globule. c ovolemma. - space between the ovolemma and the ovum, tilled with a clear fluid. the greatlv curved roof of it by the blastula-cells. Our fishembryo is now really a vesicle with eccentric cavity, like the blastula of the frog (Plate II., Fig. 10) and the salamander (Fig. 47). But, whereas in the case of these amphibia the larger vegetal half of the blastula is formed of the big yelkcells, in our bony fish it is taken up with the periblast and the structureless, undivided nutritive yelk. Then follows the important process of invagination, which leads to the formation of the gastrula. As a result oi a further enlargement and displacement of the blastula-cells, the thick borders of the cell-disk, which lie on the nutritive yelk, grow centripetally inwards towards the middle of the segmentation-cavity (Fig. 23 s). The invagination, which may also be conceived as a turning-up of the border of the blastoderm, begins at a spot that corresponds to the edge of the primitive mouth or the later anus. The inner, hollowed-out layer, consisting of one simple stratum of cells, is the entoderm ; it is immediately attached from the under side to the upper, several-layered part of the embryonic membrane, the ectoderm. In this process the segmentation cavity disappears. The space underneath the entoderm corresponds to the primitive gut-cavity, and is filled with the decreasing foodyelk (n ). Thus the formation of the gastrula of our fish is complete. In contrast to the two chief forms of gastrula we considered previously, we give the name of discoid gastrula ( discogastrula, Fig. 56) to this third principal type. As a fact, the mass of cells that compose it represent a circular, concave-convex thin disk. This disk is attached by its inner, hollow side to the curved surface of the nutritive yelk ( 11 ). If we make a horizontal section through the middle of the gastrula (in a meridian plane cf the globular composed of several strata (four in the present case) of cells (Plate III., Fig. 24). Directly over the food-yelk lies a single stratum of larger cells (Fig. 24 /), which have a soft, thick, coarse-grained protoplasm, and colour dark-red with carmine. These form the gut-layer or entoderm, and arise from the growth of the borders of the disk (folded germinal layer). The three outer strata that lie on it form the skin-layer or ectoderm (Fig. 24 e). They consist of smaller cells, that take very little colour in carmine ; their protoplasm is firmer, clearer, and finer-grained. At the thickened edge of the gastrua, (discogastrula) of a bony fish. e ectoderm, i entoderm. -,<> border-swelling or primitive mouth. n albuminous globule of the nutritive velk. f fat-globule of same. c external membrane (ovolemma). d partition between entoderm and ectoderm I earlier the segmentation cavity). Ot late years this discoid gastrulation of the bony fishes has been very carefully described by Kupffer, Van Bambeke, Whitman, Wilson, Kopsch, H. E. Ziegler, and others. In most of the teleostei it is more complicated and changed cenogenetically, because the food-yelk is very large and forms an extensive globular body, an emulsion of albumin and fatparticles. During the growth of the lens-shaped germinal disk a part of the nucleus at the border of it travels into the yelk, and forms what is called a periblast, which surrounds the blastoderm like a ring. The incompletely divided yelkcells of the periblast that are thus formed are also called '• yclk-syncytium "; they are used upas food by the embryo with the rest of the yelk, and have no part in the building-up of the body. The same applies to the covering-layer, a .simple thin stratum of flat epithelial cells, which, in many fishes, forms the uppermost layer of the blastoderm, and at its border connects with the contiguous part of the periblast, the germinal wall.1 Very similar to the discoid gastrulation of the osseous fishes is that of the myxinoida, the remarkable cyclostoma that live parasitically in the body-cavity of fishes, and are distinguished by several notable peculiarities from their nearest relatives, the lampreys (petromyzon). While the amphiblastic ova of the latter are small and develop like those of the amphibia, the cucumber-shaped ova of the myxinoida are several centimetres long, and form a discoid gastrula. Up to the present it has only been observed in one species (bdellostoma Stouti), by Dean and Doflein (1898). It is clear that the important features which distinguish the discoid gastrula from the other chief forms we have considered are determined by the large food-yelk. This takes no direct part in the building o( the germinal layers, and 1 Cf. Kingsley and Conn, Embryology of the Teleosts (1883); A. Agassiz anil C. O. Whitman, The Development 0/ Osseous Fishes (1885); M'Intosh, Development and Life-histories of Fishes ( 1890). completely fills the primitive gut-cavity of the gastrula, even protruding at the mouth-opening. If we imagine the original bell-gastrula (Figs. 32-38) trying to swallow a ball of food which is much bigger than itself, it would spread out round it in discoid shape in the attempt, just as we find to be the case here (Fig. 56). Hence we may derive the discoid gastrula from the original bell-gastrula, through the intermediate stage of the tufted gastrula. It has arisen phylogenetically by the accumulation of a store of food-stuff at the vegetal pole, a "nutritive yelk" being thus formed in contrast to the "formative yelk." Nevertheless, the gastrula is formed here, as in the previous cases, by the folding or invagination of the blastula. We can, therefore, reduce this cenogenetic form of the discoid segmentation ( gastrulatio discoidalis J to the palingenetic form of the primitive cleavage. This reduction is tolerably easy and confident in the case of the small ovum of our pelagic bony fish, but it becomes difficult and uncertain in the case of the large ova that we find in the majority of the other fishes and in all the reptiles and birds. In these cases the food-yelk is, in the first place, comparatively colossal, the formative yelk being almost invisible beside it ; and, in the second place, the food-yelk contains a quantity of different elements, which are known as "yelk-granules, yelk-globules, yelk-plates, yelk-flakes, yelkvesicles," and so on. Frequently these definite elements in the yelk have been described as real cells, and it has been wrongly stated that a portion of the embryonic body is built up from these cells.1 This is by no means the case. In every case, however large it is — and even when cell-nuclei travel into it during the cleavage of the blastoderm-border, and form a periblast — the nutritive yelk remains a dead accumulation of food, which is taken into the gut during embryonic development and consumed by the embryo. The latter developes solely from the living formative yelk of the ' The coll-like matter fruit we find in the undivided food-yelk of birds, reptiles, and fishes is anything but true cells, as His and others affirm. The true cells which we find in the food-yelk of these meroblastic ova after cleavage are migrated segmentation-cells (merocyta, Fig. 447.) and birds. The gastrulation of the primitive fishes or selachii (sharks and rays) has been carefully studied of late years by Riickert, Rabl, and H. E. Ziegler in particular, and is very important in the sense that this group is the oldest among living fishes, and their gastrulation can be derived directly from that of the cyclostoma by the accumulation of a large quantity of foodyelk. The oldest sharks (cestracion) still have the unequal segmentation inherited from the cyclostoma. But while in this case, as in the case of the amphibia, the small ovum Fig. 57.— Longitudinal section through the blastula of a shark (pristiuris). (From Riickert.) (Looked at from the left ; to the right is the hinder end, //. to the lefl the fore end, V.) />' segmentation-cavity, he cells of the germinal membrane, dk yelk-nuclei. completely divides into cells in segmentation, this is no longer so in the great majority of the selachii (or elasmobranchii). In these the contractility of the active protoplasm no longer suffices to break up the huge mass of the passive deutoplasm completely into cells ; this is only possible in the upper or dorsal part, but not in the lower or ventral section. Hence we find in the primitive fishes a blastula with a small eccentric segmentation-cavity (Fig. 57 b ), the wall of which varies greatly in composition. Only the roof (or upper wall) of it consists of real blastodermic cells, and forms the germinal disk (kz); the floor or lower wall is formed of undivided yelk-stuff, in which the presence of "elementary organisms" is only indicated by scattered yelk-granules (dk). The circular border of the germinal disk or the thin "transition zone," which connects the roof and floor of the segmentation-cavity, corresponds to the border-zone at the equator of the amphibian ovum. In the middle of its hinder border we have the beginning of the invagination of the primitive gut (Fig. 58 ud); it extends gradually from this spot (which corresponds to the Rusconian anus of the amphibia) forward and around, so that the primitive mouth becomes first crescent-shaped and then circular, and, as it opens wider, surrounds the ball of the larger food-yelk ( discogastrula eurvstoma ). Not only the obviously divided cylindrical cells of the roof (the blastocytes), but also the contiguous parts of the yelk that contain the yelk-nuclei ( dk j at the beginning' of gastrulation. (From Ruder/. ) (Seen from the left. ) Kfore end, H hind end, B segmentation-cavity or blastocoel, ud first trace of the primitive gut, dk yelk-nuclei, fd fine-grained yelk, gd coarse-grained yolk. or the nuclei of the still undivided merocytes, take part in the invagination. As these gradually divide and become independent round entodermic cells, they form the ventral wall of the primitive gut ; its dorsal wall is made up of the cylindrical cells which are formed, in a continuous simple layer, at the inner side of the roof of the segmentation-cavity during the advancing invagination. The cavity is thus pressed in on this side also, and displaced by the cavity of the primitive gut (ud). But only the back wall of this widemouthed discoid gastrula continues for some time to consist of two distinct strata of cells (the primary germinal layers), its ventral wall being composed of the yelk-stuff. As .this gradually disappears, the wide primitive mouth becomes primitive mouth is in front, the dorsal lip behind. Essentially different from this wide-mouthed discogastrula of most of the selachii is the epigastrula (of Rabl), the narrow -mouthed discoid gastrula of the amniotes, the reptiles, birds, and monotremes ; between the two — as a phylogenetic intermediate stage — we have the holoblastic amphigastrula of the amphibia. The latter has developed from the amphigastrula of the ganoids and dipneusts, whereas the discoid amniote gastrula has, in turn, evolved from the amphibian gastrula by the addition of food-yelk. This phylogenetic change of gastrulation is still found in the remarkable ophidia ( gymnophionayc(Bcilia, orperomelaj, serpent-like amphibia that live in moist soil in the tropics, and in many respects represent the transition from the gill-breathing amphibia to the lung-breathing reptiles. Their embryonic development has been explained by the fine studies of the brothers Sarasin of ichthyophis glutmosa at Ceylon (1887), and those of August Brauer of the hypogeopliis rostrata in the Seychelles (1897). It is only by the historical and comparative study of these that we can understand the difficult and obscure gastrulation of the amniotes. The bird's egg is particularly important for our purpose, because most of the chief studies of the development of the vertebrates are based on observations of the hen's egg during hatching. The mammal ovum is much more difficult to obtain and study, and for this practical and obvious reason very rarely thoroughly investigated. But we can get hens' eggs in any quantity at any time, and, by means of artificial incubation, follow the development of the embryo step by step. The bird's egg differs considerably from the tiny mammal ovum in size, a large quantity of food-yelk accumuating within the original yelk or the protoplasm of the ovum. This is the yellow ball which we commonly call the yelk of the egg. In order to understand the bird's egg aright — for it is very often quite wrongly explained — we must examine it in its original condition, and follow it from the very beginning of its development in the bird's ovary. We then see that the original ovum is a quite small, naked, and simple cell with a nucleus, not differing in either size or shape from the original ovum of themammalsand otheranimals (cf. Fig. 13-fi). As in the case of all the craniota, the original or primitive ovum ( protovum ) is covered with a continuous layer of small cells, like an epithelium. This epithelial membrane is the follicle, from which the ovum afterwards issues. Immediately underneath it the structureless yelk-membrane is secreted from the yelk. The small primitive ovum of the bird begins very early to take up into itself a quantity of food-stuff through the yelk-membrane, and work it up into the "yellow yelk." In this way the ovum enters on its second stage (the metovum j, which is many times larger than the first, but still only a single enlarged cell. Through the accumulation of the store of yellow yelk within the ball of protoplasm the nucleus it contains (the germinal vesicle) is forced to the surface of the ball. Here it is surrounded by a small quantity of protoplasm, and with this forms the lensshaped formative yelk (Fig. 59 b). This is seen on the yellow yelkball, at a certain point of the surface, as a small round white spot — the " scar " f cicatriculaj. From this scar a thread-like column of white nutritive yelk (dj, which contains no yellow yelk-granules, and is softer than the yellow food-yelk, proceeds radially to the middle of the yellow yelk-ball, and forms there a small central globule of white yelk (Fig. 59 d). The whole of this white yelk is not sharply separated from the yellow yelk, which shows a slight trace of concentric layers in the hard-boiled egg (Fig. 59 c). We also find in the hen's egg, when we break the shell and take out the yelk, a round small white disk at its surface which corresponds to the scar. But this small white "germinal disk" is now further developed, and is really the gastrula of the chick. The body of the chick is formed from it alone. The whole white and yellow yelk-mass is without any significance for the formation of the embryo, it being merely used as food by the developing chick. The clear, Fig. "i. Diagram ol discoid segmentation in the bird's ovum (magnified about ton times). Only the formative yolk (the scar) is shown in these -i\ figures ( A-F ), because cleavage only takes place in this. The much larger food-yelk, which does not share in the cleavage, is left out and merely indicated by the dark ring- without. .1 By the first division the ovinia splits into two cells. B These two first segmentation-cells divide by a second cleavage (vertical to the firsii into four cells. C From these tour cells sixteen arc formed, two other radial divisions taking place between the first two transverse divisions, and the inner ends of these eight-rayed segments being cut off by a central ring-cleavage. /> A stage with sixteen peripheral and some four concentric radial clefts. E A stage with sixty-four peripheral and six circular clefts. F By continuous repetition of radial and circular divisions tin' whole soar breaks into a heap of small cells, and now forms the lens-shaped mulberry-type (morula). The division of the nuclei .always precedes the formation o\' clefts. glarous mass of albumin that surrounds the yellow yelk of the bird's egg, and also the hard calcareous shell, are only formed within the oviduct round the impregnated ovum. When the fertilisation of the bird's ovum has taken place within the mother's body, we find in the lens-shaped stem-cell the progress of flat, discoid segmentation {gastrula discoidalis, Fig. 60). First two equal segmentation-cells (A ) are formed from the cytula. These divide into four ( B J, then into eight, sixteen (C), thirty-two, sixty-four, and so on. The cleavage of the cells is always preceded by a division of their nuclei. The cleavage surfaces between the segmentation-cells appear at the free surface of the scar as clefts. The first two divisions are vertical to each other, in the form of a cross ( B J. Then there are two more divisions, which cut the former at an angle of forty-five degrees. The scar, which thus becomes the germinal disk, now has the appearance of an eight-rayed star. A circular cleavage next taking place round the middle, the eight triangular cells divide into sixteen, of which eight are in the middle and eight distributed around ( C). Afterwards circular clefts and radial clefts, directed towards the centre, alternate more or less irregularly ( D, E). In most of the amniotes the formation of concentric and radial clefts is irregular from the very first ; and so also in the hen's egg. But the final outcome of the cleavage-process is once more the formation of a large number of small cells of a similar nature. As in the case of the fish-ovum, these segmentationcells form a round, lens-shaped disk, which corresponds to the mulberry-embryo, and is embedded in a small depression of the white yelk. Between the lens-shaped disk of the morula-cells and the underlying white yelk a small cavity is now formed by the accumulation of fluid, as in the fishes. Thus we get the peculiar and not easily recognisable blastula of the bird (Fig. 61). The small segmentation-cavity (fh) of this notably cenogenetic blastula is very fiat and much compressed. The upper or dorsal wall (dw) is formed of a single layer of clear, distinctly separated epithelial cells ; this corresponds to the upper or animal hemisphere of the tritonblastula (Fig. 47). The lower or ventral wall of the flat dividing space (vw) is made up of larger and darker segmentation-cells, which are in part not yet separated, and pass directly into the substance of the underlying white yelk (wd); it corresponds to the lower or vegetal hemisphere of the blastula of the water-salamander (Fig. 47 da J. The nuclei of the yelk-cells, which are in this case especially numerous at the edge of the lens-shaped blastula, travel The invagination or the typical folding of the birdblastula takes place in this case also at the hinder (aboral) pole of the subsequent chief axis, in the middle of the hind Fig. 61.— Vertical section of the blastula of a hen (discoblastula). fh segmentation-cavity, </:.• dorsal wall of same, vw ventral wall, passing directly into the white yelk (vdj. ( From /)«;•«/.) gastrulation : . I before incubation, />' in the first hour of incubation. (From Koller.) ks germinal disk. V it-, lore and // its hind border; cs embryonic shield ; s sickle-groove ; sk sickle knob ; d yelk. we have the most brisk cleavage of the cells ; hence the cells are more numerous and smaller here than in the fore-half of the germinal disk. The border-swelling or thick edge oi' the disk is less clear but whiteF behind, and is more sharply separated from contiguous parts. In the middle of its hind border there is a white, crescent-shaped groove — Roller's sickle-groove (Fig. 62 s) ; a small projecting process in the centre of it is called the sickle-knob ( sk). This important cleft is the primitive mouth, which was described for a long time as the "primitive groove." If we make a vertical section through this part (in the middle or sagittal plane), we see that a flat and broad cleft stretches under the germinal disk forwards from the primitive mouth ; this is the primitive gut (Fig. 63 ltd). Its roof or dorsal wall is formed by the folded upper part of the blastula, the segmentation-cavity of which is now only visible as an insignificant channel, bordered above by the simple cell-layer of the outer germinal layer (ak), and below by the inner germinal layer with its several strata (ik). The floor or the ventral wall of the flat primitive gut is formed by the white yelk fwd), in which a the discogastrula. number of yelk-nuclei (dk ) are distributed. There is a brisk multiplication of these merocytes at the edge of the germinal disk, especially in the neighbourhood of the sickle-shaped primitive mouth. We learn from sections through later stages of this discoid bird-gastrula that the primitive gut-cavity, extending forward from the primitive mouth as a flat pouch, undermines the whole region of the round flat lens -shaped blastula (Fig. 64 ud). At the same time, the segmentation-cavity gradually disappears altogether, the folded inner germinal layer (ik) placing itself from underneath on the overlying outer germinal layer (ak). The typical process of invagination, though greatly disguised, can thus be clearly seen in this case, as Goette and Rauber, and more recently Duval (Fig. 64), have shown. The older embryologists (Pander, Baer, Remak), and, in recent times especially, His, Kolliker, and others, said that the two primary germinal layers of the hen's ovum — the oldest and most frequent subject of observation ! — arose by horizontal cleavage of a simple germinal disk. In opposition to this accepted view. I affirmed in my Gastrcea Theory (1873) that the discoid bird-gastrula, like that of all other vertebrates, is formed by folding (or invagination), and that this typical process is merely altered in a peculiar way and disguised by the immense formation of spherical food-yelk and the flat spreading of the discoid blastula at one part of its surface. I endeavoured to establish this view by the monophyletic derivation of the vertebrates, and especially by proving that the birds descend from the reptiles, and these from the amphibia. If this is correct, the discoid gastrula of the amniotes must have been formed by the folding-in of a hollow blastula, as has been shown by Remak and Rusconi of the discoid gastrula of the amphibia, their direct ancestors. The accurate and extremely careful observations of the authors I have mentioned (Goette, Rauber, and Duval) have decisively proved this recently for the birds ; and the same has been done for the reptiles by the fine studies of Kupffer, Beneke, Wenkebach, and others. In the shield-shaped germinal disk of the lizard (Fig. 65), the crocodile, the tortoise, and other reptiles, we find in the middle of the hind border (at the same spot as the sickle groove in the bird) a transverse furrow ( 11 J, which leads into a fiat, pouch-like, blind sac, the primitive gut. The fore (dorsal) and hind (ventral) lips of the transverse furrow correspond exactly to the lips of the primitive mouth (or sickle-groove) in the birds. The gastrulation of the mammals must be derived from this special embryonic development of the sauropsida (reptiles and birds). This latest and most advanced class of the vertebrates has, as we shall see afterwards, evolved at a comparatively recent date from an older group of reptiles, the tocosauria; and all these amniotes must have come originally from a common older stem-form, the protamniota or proreptilia. Hence the distinctive embryonic process of the mammal must have arisen by cenogenetic modifications from the older form of gastrulation of the sauropsida. Until we admit this thesis we cannot understand phylogenetically the formation of the germinal layers in the mammal, and therefore in man. I first advanced this fundamental principle in my essay On the Gastrulation of Mammals (1877), and sought to show in this way that I assumed a phylogenetic degeneration of the food-yelk and the yelk-sac on the way from the proreptiles to the mammals. "The cenogenetic process of Ererminative area. adaptation," I said, "which has occasioned the atrophy of the rudimentary yelk-sac of the mammal, is perfectly clear. It is the adaptation to the lengthy stay in the womb of the viviparous mammal, whose ancestors were certainly oviparous. As the great store of food-yelk, which the oviparous ancestors gave to the egg, became superfluous in their descendants owing to the long carrying in the womb, and the maternal blood in the wall of the uterus made itself the chief source of nourishment, the now useless yelk-sac was bound to atrophy by embryonic adaptation." \lv opinion met with little approval at the time; it was vehemently attacked by Kolliker, Hensen, and His in particular. However, it has been gradually accepted, and has recently been firmly established by a large number of excellent studies of mammal gastrulation, especially by Edward Van Beneden's studies o{ the hare and bat, Selenka's on the marsupials and rodents, Heape's and Lieberkiihn's on the mole, Kupffer and Keibel's on the rodents, Bonnet's on the ruminants, etc. From the general Comparative point of view, Carl Rabl in his theory of the mesoderm, Oscar Hertwig in the latest edition o( his Manual (1902), and Hubrecht in his Studies in Mammalian Embryology (1891), have supported the opinion, and sought to derive the peculiarly modified gastrulation of the mammal from that of the reptile. In the meantime (1884) the studies of Wilhelm Haacke and Caldwell provided a proof of the long-suspected and very interesting fact, that the lowest mammals and the monotremes lay eggs, like the birds and reptiles, and are not viviparous like the other mammals. Although the gastrulation of the monotremes was not reallv known until studied by Richard Semon in 1894, there could be little doubt, in view of the great size of their food-yelk, that their ovum-segmentation was discoid, and led to the formation of a sickle-mouthed discogastrula, as in the case of the reptiles and birds. Hence I had, in 1875 (in my essay on The Gastrula and Ovumsegmentation of Animals), counted the monotremes among the discoblastic vertebrates. This hypothesis was established as a fact nineteen years afterwards by the careful observations o\ Semon; he gave in the second volume of his great work, Zoological Journeys in Australia (1894), the first description and correct explanation of the discoid gastrulation of the monotremes. The fertilised ova of the two living monotremes (echidna and orni/horhynchus ) are balls of 4-5 mm. diameter, enclosed in a stiff shell; but they grow considerably during development, so that when laid the tgg is three times as large (15-16 mm.). The structure of the plentiful yelk, and especially the relation of the yellow and the white yelk, are just the same as in the sauropsida. As with these, partial cleavage takes place at a spot on the surface at which the small formative yelk and the nucleus it encloses are found. First is formed a lens-shaped circular germinal disc (blastodiscus). This is made up of several strata of cells, but it spreads over the yelk-ball, and thus becomes a one-layered blastula. If we then imagine the yelk it contains to be dissolved and replaced by a clear liquid, we have the characteristic blastula (vesicula blastodennica) of the higher mammals. In these the gastrulation proceeds in two phases, have, at least at the periphery, a two-layered embryo forming from the cleavage. But in the monotremes the formation of the cenogenetic entoderm does not precede the invagination ; hence in this case the construction of the germinal layers is less modified than in the other amniota. The marsupials come next, as a second sub-class, to the oviparous monotremes, the oldest of the mammals. But as in their case the food-yelk is already atrophied, and the little ovum developes within the mother's body, the partial cleavage has been reconverted into total. One section of the marsupials still show points of agreement with the monotremes, while another section of them, according to the splendid phys) divided into four. (From Selenka.) b the four blastomeres, r directive body, c unnucleated coagulated matter, p albuminmembrane. these and the placentals. The fertilised ovum of the opossum (didelphys) divides, according to Selenka, first into two, then four, then eight equal cells ; hence the segmentation is at first equal or homogeneous. But in the course of the cleavage a larger cell, distinguished by its less clear plasm and its containing more yelk-granules (the mother-cell of the entoderm. Fig. 67 en), separates from the other blastomeres ; the latter multiply more rapidly than the former. As, further, a quantity o( fluid gathers in the morula, we get a spherical blastula, the wall of which is of varying thickness, like that of the amphioxus (Fig. 40 E) and the a wards appears. This is the mother-cell of the entoderm ; it now begins to multiply by cleavage, and the daughter-cells (Fig. 68 i) spread out from this spot over the inner surface of the blastula, though at first only over the vegetal hemisphere. The less clear entodermic cells (i) are distinguished at first by their rounder shape and darker nuclei from the higher, clearer, and longer ectodermic cells fej; afterwards both are greatly flattened, the inner blastodermic cells more than the outer. The unnucleated yelk-balls and curd (Fig. 68 d) that we find in the fluid of the blastula in these marsupials are very remarkable; they are the relics of the phylogenetically Fig. 07. Blastula of the opossum (didelphys), (From Selenka.) a animal pole of the blastula, v vegetal pole, en mothercell of the entoderm, ex ectodermic cells, s spermia, ib unnucleated yelk-balls (remainder of the food-yelk), f albumin-membrane. the monotremes, and in the reptiles. In the further course of the gastrulation of the opossum the oval shape of the gastrula (Fig. 69) gradually changes into globular, a larger quantity of fluid accumulating in the vesicle. At the same time the entoderm spreads further and further over the inner surface of the ectoderm ( e). A globular vesicle is formed, the wall of which consists of two thin simple strata of cells ; the cells of the outer germinal layer are rounder and those or the inner layer flatter. In the region of the primitive mouth (p) the cells are less flattened, and multiply briskly. From this point — from the hind (ventral) lip of the primitive mouth, which extends in a central cleft, the primitive groove — the construction of the mesoderm proceeds. Gastrulation is still more modified and curtailed cenogenetically in the placentals than in the marsupials. It was first accurately known to us by the distinguished investigations of Edward Van Beneden in 1875, the first object of study being the ovum of the hare. But as man also belongs to this sub-class, and as his as yet unstudied gastrulation Cannot be materially different from that o( the other placentals, it merits the closest attention. We have, in the first place, the peculiar feature that the two first segmentation-cells that proceed from the cleavage of the fertilised ovum (Fig, 71) are o\ different sizes and natures ; the difference is sometimes greater, sometimes less (Fig. 72). One of these first daughtercells oi the cytula — or the first two blastomeres — is a little larger, clearer, and more transparent than the other. Further, the smaller cell takes a colour in carmine, osmium, etc., spherical embryo consists oi a central mass of thirty-two soft, round cells with dark nuclei, which are flattened into polygonal shape by mutual pressure, and colour dark-brown with OSmic acid (Fig. 75 i). This dark central group of cells is surrounded by a lighter spherical membrane, consisting o( sixty-four cube-shaped, small, and fine-grained cells which lie close together in a single stratum, and only colour slightly in osrnic acid ( Fig. 75 e). The authors who regard this embryonic form as the primary gastrula of the placental conceive the outer layer as the ectoderm and the inner as the entoderm. The ectodermic membrane is only interrupted at one spot, one, two, or three of the entodermic cells being loose there. These form the yelk-stopper, and fill up the mouth of the gastrula (a). The central primitive gut-cavity (d) is full of entodermic Fig. 71.— Stem-cell or eytula of the mammal ovum (from the hare). k stem-nucleus, n nuclear corpuscle, p protoplasm of the stem-cell, z modified zona pellucida, h outer albuminous membrane, 5 dead sperm-cells. cells (Plate II., Fig. 17). The uni-axial type of the mammal gastrula is accentuated in this way. However, opinions still differ considerably as to the real nature of this " provisional gastrula" o( the placental and its relation to the blastula into which it is converted. As the gastrulation proceeds a large spherical blastula is formed from this peculiar solid amphigastrula of the placental, as we saw in the case of the marsupial. The accumulation of fluid in the solid gastrula (Fig. 76 A) leads to the formation of an eccentric cavity, the group of the darker entodermic cells ' Iiv ) remaining directly attached at one spot with the lation of the placental has been greatly modified by secondary adaptation in the various groups of this most advanced and youngest sub-class of the mammals. Thus, for instance, we find in many of the rodents (guinea-pigs, mice, etc. ) apparently a temporary inversion of the two germinal layers. This is due to a folding of the blastodermic wall by what is called the "girder," a plug-shaped growth of Rauber's "roof-layer." 1 1 is a thin layer of flat epithelial cells, that is freed from the surface of the blastoderm in some of the rodents ; it has no more significance in connection with the general course o( l'n- 75. Gastrula of the placental mammal (epigastrula from the hare), longitudinal section through the axis, r eetodermic cells (sixty-four, lighter and smaller), i entodermic cells (thirtytwo, darker and larger), d central entodermic cell, filling the primitive gutcavity, o peripheral entodermic cell, stopping up the opening of the primitive mouth (yelk-stopper in the Rusconian anus). placental gastrulation than the conspicuous departure from the usual globular shape in the blastula of some of the ungulates. In some pigs and ruminants it grows into a thread-like, long and thin tube. Thus the gastrulation of the placentals, which diverges most from that of the amphioxus, the primitive form, is reduced to the original type, the invagination of a modified blastula. Its chief peculiarity is that the folded part of the blastoderm does not form a completely closed (only open at the primitive mouth) blind sac, as is usual ; but this blind sac has a wide opening at the ventral curve (opposite to the dorsal mouth) ; and through this opening the primitive gut entoderm. communicates from the first with the embryonic cavity of the blastula. The folded crest-shaped entoderm grows with a free circular border on the inner surface of the entoderm towards the vegetal pole ; when it has reached this, and the inner surface of the blastula is completely grown over, the primitive gut is closed. This remarkable direct transition of the primitive gut-cavity into the segmentation-cavity is explained simply by the assumption that in most of the mammals the yelk-mass, which is still possessed by the oldest forms of the class (the monotremes) and their ancestors (the reptiles), is atrophied. This proves the essential unity of gastrulation in all the vertebrates, in spite of the striking differences in the various classes. In order to complete our consideration of the important processes of segmentation and gastrulation, we will, in conclusion, cast a brief glance at the fourth chief type — superficial segmentation (Plate III., Figs. 25-30). In the vertebrates this form is not found at all. But it plays the chief part in the large stem of the articulates — the insects, spiders, myriapods, and crabs. The distinctive form of gastrula that comes of it is the " vesicular gastrula " (perigastrula, Plate III., Fig. 29). In the ova which undergo this superficial cleavage the formative yelk is sharply divided from the nutritive yelk, as in the preceding cases of the ova of birds, reptiles, fishes, etc.; the formative yelk alone undergoes cleavage. But while in the telolecithal ova with discoid gastrulation the formative velk is not in the centre, but at one pole of the uni-axial ovum, and the food-yelk gathered at the other pole, in the ova with superficial cleavage we find the formative yelk spread over the whole surface of the ovum; it encloses spherically the food-yelk, which is accumulated in the middle of the centrolecithal ova. As the segmentation only affects the former and not the latter, it is bound to be entirely "superficial"; the store of food in the middle is quite untouched by it. As a rule, it proceeds in regular geometrical progression (Plate III., Figs. 25-30, illustrates some stages of it in vertical section through the ellipsoid ova of a crab, pencils). The stem-nucleus, or first segmentation-nucleus, which is situated originally in the centre of the stem-cell, divides into two, then four, eight, and finally sixteen nuclei. These travel centrifugally out of the central food-yelk, and distribute themselves at equal distances in the superficial formative yelk (Plate III., Fig. 26). Mere they multiply continuously by cleavage (Fig. 27). Finally the whole of the formative yelk divides into a number of small and homogeneous cells, which lie close together in a single stratum on the entire surface of the ovum, and form a superficial blastoderm (Fig. 286). This blastoderm is a simple, completely closed vesicle, the internal cavity of which is entirely full of food-yelk. This real blastula (Fig. 28) only differs from that of the archiblastic ova (Plate II., Fig. 4) in its chemical composition. In the latter the content is water or a watery jelly ; in the former it is a thick mixture, rich in food-yelk, of albuminous and fatty substances. As this quantity of food-yelk fills the centre of the ovum before cleavage begins, there is no difference in this respect between the mulberry-embryo and the vesicular embryo. The two stages, morula and blastula, rather agree in this. When the blastula (Plate III., Fig. 28) is fully formed, we have again in this case the important folding or invagination that determines gastrulation (Fig. 29). At one part of the surface a round, pit-shaped depression appears, and this grows into a cavity — the primitive gut-cavity of the gastrula (Fig. 29 a); the point of invagination forms the primitive mouth (0). The folded part of the blastoderm, the cells of which are enlarged and assume a slender cylindrical shape, forms the gut-layer and encloses the primitive gut-cavity. The superficial part of the blastoderm that is not folded forms the skin-layer ; its cells become smaller by repeated cleavage, and are flattened. The space between the skinlayer and the gut-layer (the remainder of the segmentationcavity) remains full of food-yelk, which is gradually used up. This is the only material difference between our vesicular gastrula (perigastrula, Fig. 29) and the original form of the bell-gastrula (archigastrula, Fig. 6). Clearly the one has been developed from the other in the course of time, owing to the accumulation of food-yelk in the centre of the ovum.1 We must count it an important advance that we are thus in a position to reduce all the various embryonic phenomena in the different groups of animals to these four principal forms of segmentation and gastrulation. Of these four forms we must regard one only as the original palingenetic, and the other three as cenogenetic and derivative. Both the unequal, the discoid, and the superficial segmentation have clearly arisen by a secondary adaptation from the primary ' On the reduction of all forms of gastrulation (including " delamination ") to the original palingenetic form see especially the lucid treatment of the subject in Arnold Lang's Manual of Comparative Anatomy (1S8S), Part I. segmentation j and the chief cause o\ their development has been the gradual formation of the food-yelk, and the increasing antithesis between animal and vegetal halves of the ovum, or between ectoderm (skin-layer) and entoderm (gut-layer). The numbers o( careful studies o( animal gastrulation that have been made in the last few decades have completely established the views 1 have expounded, and which I first advanced in the years 1N72-76. For a time they were greatly disputed by many embryologists. Some said that the original embryonic form of the metazoa was not the gastrula, but the planula — a double-walled vesicle with closed cavity and without mouth-aperture; the latter was supposed to pierce through gradually. It was afterwards shown that this planula (found in several groups of the cnidaria) was a later evolution from the gastrula. It was also shown that what is called delamination — the rise of the two primary germinal layers by the folding of the surface of the blastoderm (for instance, in the geryonidce and other medusas) — was a secondary formation, due to cenogenetic variations in time, from the original invagination of the blastula. The same may be said of what is called " immigration," in which certain cells or groups of cells are detached from the simple epithelial layer of the blastoderm, and travel into the interior of the blastula; they attach themselves to the inner wall of the blastula, and form a second internal epithelial layer — that is to say, the entoderm. In these and many other controversies of modern embryology the first requisite for clear and natural explanation is a careful and discriminative distinction between palingenetic (hereditary) and cenogenetic (adaptive) processes. If this is properly accomplished, we End evidence everywhere of the biogenetic law. Secondary form of Ova small, with the gastrula. moderate foodPrimitive gut full yolk, telolecithal. of segmented food- THE CCELOM THEORY1 Number of the germinal layers in animals. Two-layered and three-layered animals (coelenteria). Four-layered animals, with two limiting layers and two eentral layers (coelomaria). Gut-cavity and body-cavity. Nature of the four secondary germinal layers. Theories of their origin (folding' and cleavage). Older theories of Baer and Remak. Hertwig's ccelom theory : formation of the body-cavity, primarily by folding, secondarily by cleavage. Approach of the two coelom-pouches from the primitive mouth. Ccelomation of sagitta and amphioxus. Palingenetic and cenogenetic ccslomation. Parietal layer (skin-fibre layer) and visceral layer (gut-fibre layer). Ccelomula and chordula. Corresponding stem-forms : ccelomaea and chordsea. Separation of the chorda from the dorsal wall of the primitive gut (between the two ccelom-pouches). Empty and full pouches. The coelom-pouches of the bilaterals were originally sexual glands. Their ventral coalescence. Dorsal mesentery. Cenogenetic ccelomation of the amphibia and amniotes. The primitive mouth of the amniote embryo becomes the primitive groove. The border of the primitive mouth (properistoma) as vegetation-point or source of embryonic development (blastocrene). The four-layered coelomula of the reptiles, birds, and mammals. The two blastophylls or " primary germinal layers " which the gastraja theory has shown to be the first foundation in the construction of the body are found in this simplest form throughout life only in ccelenteria of the lowest grade — in the gastrsads, olynthus (the stem-form of the sponges), hydra, and cognate very simple cnidaria. In all the other animals new strata of cells are formed subsequently between these two primary body-layers, and these are generally comprehended under the title of the middle layer, or mesoderm. As a rule, the various products of this middle layer afterwards constitute the great bulk of the animal frame, while the 1 Cf. Huxley, "On the Classification of the Animal Kingdom" (Quart. Journ. of Micros. Sc., vol. xv.); E. Ray-Lankester, "On the Invaginate Planula or Diploblastic Phase of Paludina Yivipara " (Quart. Journ. of Micros. Sc, vol. xv.) and " Revision of Speculations Relative to the Origin and Significance of the Germ-layers" (Quart. Journ. Micros. Sc, vol. xvii. ) ; Francis Balfour, " Early Stages in the Development of Vertebrates " (Quart. Journ. Micros. Sc, vol. xv. ). original entoderm, or internal germinal layer, is restricted to the clothing of the alimentary canal and its glandular appendages ; and, on the other hand, the ectoderm, or external germinal layer, furnishes the outer clothing of the body, the skin and nervous system. In some large groups of the lower animals the middle germinal layer remains a single connected mass ; these have been called the three-layered metazoa, in opposition to the two-layered i;astra?ads and hydroids. To this category belong, for instance, most of the sponges and the corals or anthozoa. The greater part of the body in these animals consists of mesodermal supporting tissue and skeletal structures embedded therein ; the entodermal epithelium confines itself to clothing the alimentary gastro-canal system, the ectodermal epithelium to the cell-coverin£ of the outer skin. In the platodes also (the spiral, suctorial, and tape worms) the greater part of the body belongs genetically to a unified " middle layer," which has been developed between the two primary germinal layers of the gastrula. All these three-layered animals (triploblastica), like the two-layered ccelenteria ( diploblastica j, have no body-cavity — that is to say, no cavity distinct from the alimentary system ; hence, they are also called acoelomia. On the other hand, all the higher animals have this real body-cavity ( cocloma ), and so are called ccelomaria. In all these we can distinguish four secondary germinal layers, which develop from the two primary layers ; hence, the ccelomaria may also be contrasted with the ccelenteria as four-layered metazoa ( tetrablastica >. To this category belong all true vermalia (excepting the platodes), and also the higher typical animal stems that have been evolved from them — molluscs, echinoderms, articulates, tunicates, and vertebrates. The body-cavity (caeloma) is therefore a new acquisition oi the animal body, much younger phylogenetically than the alimentary system, and of great importance both morphologically and physiologically. I first pointed out this fundamental significance of the ccelom in my monograph on the .sponges (1872), in the section which draws a distinction between the body-cavity and the gut-cavity, and which follows immediately on the germ-layer theory and the ancestral tree of the animal kingdom (the first sketch of the gastraja theory). Up to that time these two principal cavities of the animal body had been confused, or very imperfectly distinguished ; chiefly because Leuckart, the founder of the ccelenterata group (1848), has attributed a body-cavity, but not a gut-cavity, to these lowest metazoa. In reality, the truth is just the other way about. The ventral cavity, the original organ of nutrition in the multicellular animal-body, is the oldest and most important organ of all the metazoa, and, together with the primitive mouth, is formed in every case in the gastrula as the primitive gut ; it is only at a much later stage that the body-cavity, which is entirely wanting in the ccelenterata, is developed in some of the metazoa between the ventral and the bodv wall. The two cavities are entirely different in content and purport. The alimentary cavity (enteron) serves the purpose of digestion ; it contains water and food taken from without, as well as the pulp (chymus) formed from this by digestion. On the other hand, the body-cavity, quite distinct from the gut and closed externally, has nothing to do with digestion ; it encloses the gut itself and its glandular appendages, and also contains the sexual products and a certain amount of blood or lymph, a fluid that is transuded through the ventral wall. As soon as the body-cavity appears, the ventral wall is found to be separated from the enclosing body-wall, and the two continue to be directly connected at various points. We can also then always distinguish a number of different lavers of tissue in both walls — at least two in each. These tissuelayers are formed originally from four different simple celllayers, which are the much-discussed four secondary germinal layers. The outermost of these, the skin-sense-layer (Figs. 77, 78 /is), and the innermost, the gut-gland-layer (del), remain at first simple epithelia or covering-layers. The one limits the outer surface of the body, the other the inner surface of the ventral wall ; hence thev are cavity. The four secondary germinal layers are so distributed in the structure of the body in all the coslomaria (or all metazoa that ha\c a body-cavity) that the outer two, joined fast together, constitute the body-wall, and the inner two the ventral wall ; the two walls are separated by the cavity of the ccelom. Each of the walls is made up of a limiting layer and a middle layer. The two limiting layers chiefly give rise to epithelia, or covering-tissues, and glands and nerves, while the middle layers form the great bulk of the fibrous tissue, muscles, and connective matter. Hence the latter Figs. 77 and 7S. Diagram of the four secondary germinal layers, transverse section through tin- metazoic embryo: Fig. 77 of an annelid, Fig. 7S of a vermale. u primitive gut, (/</ ventral glandular layer, rf/ ventral fibrelayer, hm skin-fibre-layer, hs skin-sense-layer, » traces of tin- rudimentary kidneys, '/ trace of the nerve-plates. have also been called fibrous or muscular layers. The outer middle lavcr, which lies on the inner side of the skin-senselavcr, is the skin fibre-layer; the inner middle layer, which attaches from without to the ventral glandular-layer, is the ventral fibre-layer. The former is usually called briefly the parietal, and the latter the visceral layer, or mesoderm. Of the many different names that have been given to the four secondary germinal layers, the following are those most in use to-day : — IV. Epithelial. The first scientist to recognise and clearly distinguish the four secondary germinal layers was Baer. It is true that he was not quite clear as to their origin and further significance, and made several mistakes in detail in explaining them. But, on the whole, their great importance did not escape him, and he advanced the view as to the origin of the two middle layers which was afterwards adopted by most embryologists, and which I gave in the first edition of the Anthropogeny. He derives each of the middle layers separately from a primary germinal layer (by cleavage), and says that the outer or animal layer divides into two folds (a skin-layer and a muscle-layer), and the inner or vegetative layer into two also (a vascular and a mucous layer). As compared with the more recent and usual terminology, Baer's opinion may be put as follows : — Gastral limiting layer. This opinion of Baer's, which had a good deal of probability in respect of the physiological division of labour among the germinal layers, had to be given up later on in consequence of more accurate observations. Remak had stated, in 1850, in the first part of his distinguished Studies of Vertebrate Development, that in the two-layered germinal disk o( the new-laid hen's egg (our discogastrulaj a few hours after incubation the lower germinal layer divides into two — a middle germinal layer and a glandular layer. Subsequently the middle germinal layer, or fibrous layer, had to split up again into two — an inner gut-fibre layer and an outer skinfibre layer. The relation oi' Remak's " three-layer theory " to Baer's original "tour-layer theory" may be expressed as follows : — Remak's theory of the germinal layers, in the following-up of which this distinguished observer made some very important discoveries, soon met with approval, especially as it was the first clear recognition of the constituent elementary parts of the germinal layers, and the first provision of an histological foundation for ontogeny by an application of the cell theory. The assumption that the secondary germinal layers arise from the primary by the cleavage of surfaces— in which Baer and Remak agree — was admitted by embryologists who dissented on other points — Kolliker, for instance, who holds that "in the higher vertebrates the middle germinal layer originates from the outer." These generally-accepted theories oi' cleavage began in give way thirty years ago, when Kowalevsky (1871) showed that in the ease of sagitta (a very clear and typical subject of gastrulation) the two middle germinal layers and the two limiting lavers arise not by cleavage, but by folding — a secondary invagination oi' the primary inner germ-layer. This invagination proceeds from the primitive mouth, at the two sides of which (right and left) a couple of pouches are formed. As these ccelom-pouches or ccelom-sacs detach themselves from the primitive gut, a double body-cavity is formed (Figs. 77-9). The same kind of ccelom-formation as in sagitta was afterwards found by Kowalevsky in brachiopods and other invertebrates, and in the lowest vertebrate — the amphioxus. Further instances were discovered by two English embryologists, to whom we owe very considerable advance in ontogeny — E. Ray-Lankester and F. Balfour. On the strength of these and other studies, as well as most extensive research of their own, the brothers Oscar and Richard Hertwig constructed in 1881 the Ccelom Theory : An Attempt to Explain the Middle Germinal Layer. In order to appreciate fully the great merit of this illuminating and helpful theory one must remember what a chaos of contradictory views was then represented by the " problem of the mesoderm," or the much-disputed "question of the origin of the middle germinal layer." In particular the curious " parablast theory" of the Leipzig embryologist, His, based on the most perverse assumptions, had caused a frightful confusion ; not only all possible, but a good many impossible, ideas as to the origin of the secondary germinal layers, the development of the tissues from them, and the building-up of the animal body, were then seriously and dogmatically discussed (cf. Chapter III., p. 49). The ccelom theory of the brothers Hertwig brought some light and order into this infinite confusion by establishing the following points : 1. The body-cavity originates in the great majority of animals (especially in all the vertebrates) in the same way as in sagitta; a couple of pouches or sacs are formed by folding inwards at the primitive mouth, between the two primary germinal layers ; as these pouches detach from the primitive gut, a pair of ccelom-sacs (right and left) are formed ; the coalescence of these produces a simple body-cavity (enteroccel). 2. When these ccelom-embryos develop, not as a pair of hollow pouches, but as solid layers of cells (in the shape of a pair of mesodermal streaks) — as happens in the higher vertebrates— we have a secondary (cenogenetic) modification of the primary (palingenetic) structure ; the two walls of the pouches, inner and outer, are pressed together by the expansion o\ the large food-yelk. 3. Hence the mesoderm consists from the first of two genetically distinct layers, which do not originate by the cleavage of a primary simple middle layer (as Remak supposed). 4. These two middle layers have, in all vertebrates, and the great majority of the invertebrates, the same radical significance for the construction o( the animal body; the inner middle layer, or the visceral mesoderm (gut-fibre-layer), attaches itself to the original entoderm, and forms the fibrous, muscular, and connective part of the visceral wall (splanchnopleura); the outer middle laver, or the parietal mesoderm (skin-fibre-layer), attaches itself to the original ectoderm, and forms the fibrous, muscular, and connective part of the body-wall ( ' somatopleural J. 5. It is only at the point of origination, the primitive mouth and its vicinity, that the four secondary germinal layers are directly connected ; from this point the two middle layers advance forward separately between the two primary germinal layers, to which the}' severally attach themselves. 6. The further separation or differentiation of the four secondary germinal layers and their division into the various tissues and organs take place especially in the later fore-part or head of the embryo, and extend backwards from there towards the primitive mouth. All animals in which the body-cavity demonstrably arises in this way from the primitive gut (vertebrates, tunicates, echinoderms, articulates, and a part of the vermalia) were comprised by the Hertwigs under the title of cnteroca/a, and were contrasted with the other groups of the pseudocosla (with false body-cavity) and the ccelenterata (with no body-cavity). Among the pseudoccela they counted the molluscs and a part of the vermalia (plathelmintha, bryozoa, and rotatoria). In these cases the body-cavity either represented a relic ot the segmentation-cavity (blastoccel) or arose secondarily by cleavage or the formation of holes in a solid mesoderm (schizocoel). However, this radical distinction and the views as to classification which it occasioned have been shown to be untenable. Further, the absolute differences in tissueformation which the Hertwigs set up between the enterocoela and pseudoccela cannot be sustained in this connection. For these and other reasons their ccelom-theory has been much criticised and partly abandoned. Nevertheless, it has rendered a great and lasting service in the solution of the difficult problem of the mesoderm, and a material part of it will certainly be retained. I consider it an especial merit of the theory that it has established the similarity of the development of the two middle layers in all the vertebrates, and has traced them as cenogenetic modifications back to the original palingenetic form of development that we still find in the amphioxus. Carl Rabl comes to the same conclusion in his able Theory of the Mesoderm, and so do Ray-Lankester, Rauber, Kupffer, Riikert, Selenka, Hatschek, and others. There is a general agreement in these and many other recent writers that all the different forms of ccelom-construction, like those of gastrulation, follow one and the same strict hereditary law in the vast vertebrate stem ; in spite of their apparent differences, they are all only cenogenetic modifications of one palingenetic type, and this original type has been preserved for us down to the present day by the invaluable amphioxus. But before we go into the regular ccelomation of the amphioxus, we will glance at that of the arrow-worm (sagitta), the remarkable pelagic worm that is interesting in so many ways for comparative anatomy and ontogenv. On the one hand, the transparency of the clear body and its embryo, and, on the other hand, the typical simplicity of its palingenetic development, make the sagitta a most instructive object in connection with various problems. The class of the chcetognatlia, which is only represented by the cognate genera of sagitta and spadella, is in another respect also a most remarkable branch of the extensive worm-stem. It was therefore very gratifying that Oscar Hertwig (1880) fully explained the anatomy, classification, and evolution of the chajtognatha in his careful monograph. The spherical blastula thai arises from the impregnated ovum o( the sagitta is converted by uni-polar folding into a typical archigastrula, entirely similar to that of the monoxenia which I described (Chapter VIII., Fig. ,}i). This oval, uni-axial cup-larva (circular in section) becomes bilateral (or tri-axial) by the growth o( a couple of ccelum-pouches from the primitive gut (Figs. 79, 80). To the right and left a sac-shaped fold appears towards the oral pole (where the permanent month, in, afterwards arises). The two sacs are at fust separated by a couple oi folds of the entoderm (Fig. 71) pv), and are still connected with the primitive gut '. -Ccelomulaof sagitta. in soil ion. CFroxaHertiuig.) D dorsal side, V ventral sido, ik inner germinal layer, mv visceral mesoblast, //; body-cavity, mp parietal mesoblast, ak outer germinal layer. by wide apertures; they also communicate for a short time with the dorsal side (Fig. 80 </). Soon, however, the ccelompouches completely separate from each other and from the primitive gut; at the same time they enlarge so much that they close round the primitive gut (Fig. 81). But in the middle line o( the dorsal and ventral sides the pouches remain separated, their approaching walls joining here to form a thin vertical partition, the mesentery (dm and vm j. Thus sagitta has throughout life a double body-cavity (Fig. 81 ///), and the gut is fastened to the body-wall both above and below by a mesentery — below by the ventral mesentery fvmj, and above by the dorsal mesentery (dm). The inner layer of the two ccelom-pouches (visceral mesoblast, mv) attaches itself to the entoderm ( ik), and forms with it the visceral wall. The outer layer (parietal mesoblast, nip) attaches itself to the ectoderm (ak), and forms with it the outer body wall. Thus we have in sagitta a perfectly clear and simple illustration of the original ccelomation of the enteroccela. This palingenetic fact is the more important, as the greater part of the two body-cavities in sagitta changes afterwards into sexual glands — the fore or female part into a pair of ovaries, and the hind or male part into a pair of testicles. Ccelomation takes place with equal clearness and transparency in the case of the amphioxus, the lowest vertebrate, and its nearest relatives, the invertebrate tunicates, the ascidia. However, in these two stems, which we class together as chordonia, this important process is more complex as two other processes are associated with it — the development of the chorda from the entoderm and the separation of the medullary plate or nervous centre from the ectoderm. Here again the s'cullless amphioxus has preserved to our own time by tenacious heredity the chief phenomena in their original form, while it has been more or less modified by embryonic adaptation in all the other vertebrates (with skulls). Hence we must once more thoroughly understand the palingenetic embryonic features of the lancelet before we go on to consider the cenogenetic forms of the craniota. The ccelomation of the amphioxus, which was first observed by Kowalevsky in 1867, has been very carefully studied since by Hatschek (18S1). According to him, there are first formed on the bilateral gastrula we have already considered (Figs. 40, 41) three parallel longitudinal folds — one single ectodermal fold in the central line of the dorsal surface, and a pair o( entodermie folds at the two sides of the former. The broad ectodermal fold that first appears in the medium line o( the flattened dorsal surface, and forms a shallow longitudinal groove, is the beginning of the central nervous system, the medullary tube. Thus the primary outer germinal layer divides into two parts, the medium medullary plate (Fig. 84 nip) and the horn-plate ( ' ak J, the beginning o( the outer skin or epidermis. As the parallel borders of the concave medullary plate fold towards each Figs. s.> and 83.— Transverse section of amphioxus-larvae. (From Haischek.) Fig. 82 at the commencement of ccelom-formation (siill without segments), Fig. 83 at the stage with lour primitive segments, til-, ik, »ik outer, inner, and middle germinal layer, lip horn plate, mp medullary plate, ch chorda, * ana disposition of the ccelom-pouches, //; body-cavity. other and ijrow underneath the horn-plate, a cylindrical tube is formed, the medullary tube (Fig. 85 n); this quickly detaches itself altogether from the horn-plate. At each side of the medullary tube, between it and the alimentary tube (l;ii,rs. S2 S5 <///), the two parallel longitudinal folds grow out o( the dorsal wall of the alimentary tube, and these form the two ccelom-pouches (Figs. 83 and S4 //;). This part of the entoderm, which thus represents the first structure of the middle germinal layer, is shown darker than the rest o( the inner germinal layer in Figs. 82 85. The place of the double mesoderm ie fold is indicated in Fig. 83 with asterisks (* ). The basal edges of the curved folds grow together at these points, and form closed pouches (Fig. 84 in transverse section). The hindermost part of the two parallel mesodermic folds attaches originally to the border of the primitive mouth, and is connected there with the two large " primitive mesodermic cells" or " promesoblasts," which we have considered previously (Fig. 41 p). The embryonic structures that develop from the latter may be called, with Rabl, peristomal mesoblasts, in opposition to the structures of the former, the gastral mesoblasts. During this interesting process the outline of a third very important organ, the chorda or axial rod, is being formed between the- two ecelom-pouches. This first foundation of Figs. 84 and 85.— Transverse section of amphioxus embryo. Fig. S4 at the stage with five somites. Fig. 85 at the stage with eleven somites. (From Hatschei.) ak outer germinal layer, mp medullary plate, n nerve-tube, ik inner germinal layer, d/i visceral cavity, //; body-cavity, ink middle germinal layer (mkl parietal, ///k.: visceral), us primitive segment, c/i chorda. the skeleton, a solid cylindrical cartilaginous rod, is formed in the median line of the dorsal primitive gut-wall, from the entodermal cell-streak that remains here between the two ecelom-pouches (Figs. S2-85 ch). The chorda appears at first in the shape of a flat longitudinal fold or a shallow groove (Figs. 83, 84) ; it does not become a solid cylindrical cord until after separation from the primitive gut (Fig. 85). Hence we might say that the dorsal wall of the primitive gut forms three parallel longitudinal folds at this important period — one single and a pair of folds. The single medium longitudinal fold becomes the chorda, and lies immediately bocomo the medullary tube ; the pair of longitudinal folds, right and left, lie at the sides between the former and the latter, and form the ccelom-pouches. The part of the primitive gut that remains after the cutting o(i o( these three dorsal primitive organs is the permanent gut (enteron or mesodaeum); its entoderm is the gut-gland-layer or enteric layer (enteroblast). I give the name of ckordula or chordalarva to the embryonic stage o( the vertebrate organism which is represented by the amphioxus larva at this period (Figs. 86, 87, in the third period of development according to Hatschek). (Strabo and Plinius give the name of cordula or cordyla to young tish larvae.) I ascribe the utmost phylogenetic significance to it, as it is found in all the chordoma (tunicates as well as vertebrates) in essentiallv the same form. Although the construction of the large food-yelk greatly modifies the form of the chordula in the higher vertebrates, it remains the same in its main features throughout. In all cases the nervetube ' m > lies on the dorsal side of the bilateral, worm-like body, the visceral tube fdj on the ventral side, the chorda fchj between the two, on the long axis, and the ccelompouches (c) at each side. In every case these primitive organs develop in the same way from the germinal layers, and the same organs always arise from them in the mature chorda-animal. Hence we may conclude, according to the laws of heredity of the theory of descent, that all these chordonia or chordata (tunicates and vertebrates) descend from an ancient common ancestral form, which we may call chordcea. We should regard this long-extinct chordasa, if it were still in existence, as a special class of unarticulated worm (chordariaj. It is especially noteworthy that neither the dorsal nerve-tube nor the ventral gut-tube, nor even the chorda that lies between them, shows any trace of articulation or metamera-formation ; even the two ccelom-sacs are not segmented at first (though in the amphioxus they quickly divide into a series of somites by transverse folding). These ontogenetic facts are of the greatest importance for the purpose of learning those ancestral forms of the vertebrates which we have to seek in the group of the unarticulated vermalia. The ccelom-pouches were originally sexual glands in these ancient chordonia. Figs. 86 and 87.— Chordula Of the amphioxus. Fig. 86 median longitudinal section (seen from the left). Fig. 87 transverse section. 1 From Hatschek.) In F"ig. 86 the ccelom-pouches are omitted, in order to show the chordula more clearly. F~ig. 87 is rather diagrammatic. /; horn-plate, m medullary tube, // wall of same (»' dorsal n" ventral), ch chorda, np neuroporus, tie canalis neurentericus, d gut-cavity, r gut dorsal wall, b gut ventral wall, s yelk-cells in the latter, 11 primitive mouth, 0 mouth-pit, p promesoblasts (primitive or polar cells of the mesoderm), ti' parietal layer, ?' visceral layer oi the mesoderm, c ccelom, f rest of the segmentation-cavity. Figs. S8 and 89.— Chordula of the amphibia (the ringed snake). (From Goette.) Fig. 88 median longitudinal section (seen from the left), Fig. 89 transverse section (slightly diagrammatic). Lettering as in Figs. 86 and 87. arc, in any case, older than the chorda ; since they also develop in the same way as in the chordoma in a number of invertebrates which have no chorda (for instance, sagitta, Figs. 7q Si). Moreover, in the amphioxus the first outline of the chorda appears later than that of the ccelom-sacs. Hence we must, according to the biogenetic law, postulate a special intermediate form between the gastrula and the chordula, which we will call cceiomula, an unarticulated, worm-like body with primitive gut, primitive mouth, and a douhle body-cavity, hut no chorda. This embryonic form, the bilateral cceiomula (Fig. 84), may in turn be regarded as the ontogenetic reproduction (maintained by heredity) of an ancient ancestral form of the civlomaria, the ccelomaea (cf. Chapter XX. ). In sagitta and other helmintha the two ccelom-pouches (presumably the gonades or sex-glands of the ceeloma?a) are separated by a complete median partition, the dorsal and ventral mesentery (Fig. Si dm and vm) ; but in the vertebrates only the upper part of this vertical partition is maintained, and forms the dorsal mesenterv. This mesenterv afterwards takes the form of a thin membrane, which fastens the visceral tube to the chorda (or the vertebral column). At the under side of the visceral tube the ccelom-sacs blend together, their inner or median walls breaking down and disappearing. The body-cavity then forms a single simple hollow, in which the gut is quite free, or only attached to the dorsal wall by means of the mesentery (cf. Plate IY., Fig. 5). The development of the body-cavity and the formation of the chordula in the higher vertebrates is, like that of the gastrula, chiefly modified by the pressure of the food-yelk on the embryonic structures, which forces its hinder part into a discoid expansion. These cenogenetic modifications seem to be so great that until twenty years ago these important processes were totally misunderstood. It was generally believed that the body-cavity in man and the higher vertebrates was due to the division of a simple middle layer, and that the latter arose by cleavage from one or both of the primary germinal layers. The truth was brought to light at last by the comparative embrvological research of the Hertwigs. They showed in their Coelom Theory (1881) that all vertebrates are true enteroccela, and that in every case a pair of ccelom-pouches are developed from the primitive gut by folding. The cenogenetic chordula-forms of the craniotes must therefore be derived in the same way from the palingenetic embryology of the amphioxus, as I had previously proved for their gastrula-forms. The chief difference between the ccelomation of the acrania (amphioxus J and the other vertebrates (craniotes) is that the two ccelom-folds of the primitive gut in the former are from the first hollow vesicles, filled with fluid, but in the latter are empty pouches, the layers of which (inner and outer) close with each other. In common parlance we still call a pouch or pocket by that name, whether it is full or empty. It is different in ontogeny; in embrvological literature ordinary logic does not count for very much. In many of the manuals and large treatises on this science it is proved that vesicles, pouches, or sacs deserve that name only when they are inflated and filled with a clear fluid. When they are not so filled (for instance, when the primitive gut of the gastrula is filled with yelk, or when the walls of the empty coelom-pouches are pressed together), these vesicles must not be cavities any longer, but " solid structures." The evolution of the large food-yelk in the ventral wall of the primitive gut (Figs. 88, 89) is the simple cenogenetic cause that converts the sac-shaped ccelom-pouches of the acrania into the leaf-shaped ccelom-streaks of the craniotes. To convince ourselves of this we need only compare, with Hertwig, the palingenetic ccelomula of the amphioxus (Figs. 83, 84) with the corresponding cenogenetic form of the amphibia (Figs. 92-94), and construct the simple diagram that connects the two (Figs. 90, 91). If we imagine the ventral half of the primitive gut-wall in the amphioxus embryo (Figs. 82-87) distended with food-yelk, the vesicular ccelom-pouches (lh) must be pressed together by this, and forced to extend in the shape of a thin double plate between the gut-wall and body-wall (Figs. 89, cp^TaasUx^hsTorf follows a downward and forward direction. They arc not directly connected with these two walls. The real unbroken connection between the two middle layers and the primary germ-layers is found right at the back, in the region of the primitive mouth (Fig. qo 11). At this important spot we have the source of embryonic development (blastocrene), or "zone of growth," from which the coelomation (and also the gastrulation) originally proceeds. Figs. 9oand 91. Diagrammatic vertical section of ecelomula-embryos Of vertebrates. (From Hertwig.} Fig. 90, vertical section through the primitive mouth. Fig. 91, vertical section before the primitive mouth. 11 primitive mouth, net primitive gut, d yelk, ilk yelk-nuclei, dh gut-cavity, /// body-cavity, w/> medullary plate, ch chorda plate, uk and ik outer and inner germinal layers, pb parietal ami -.■!> visceral mesoblast. structures of the two middle layers, the relic of the bodycavity, which is represented in the diagrammatic transitional form (Figs. 90, 91). In sections both through the primitive mouth itself (Fig. 92) and in front of it (Fig. 93) the two middle layers (pb and vb ) diverge from each other, and disclose the two body-cavities as narrow clefts. At the primitive mouth itself (Fig. <>;, u) we can penetrate into them from without. It is only here at the border oi the primitive mouth that we can show the direct transition of the two middle layers into the two limiting lasers or primary germinal layers. The structure of the chorda also shows the same features in these ccelomula-embryos of the amphibia (Fig. 94) as in the amphioxus (Figs. 82-85). It arises from the entodermic cell-streak, which forms the middle dorsal line of the primitive gut, and occupies the space between the flat ccelom-pouches (Fig. 94 A). While the nervous centre is formed here in the median line of the back and separated from the ectoderm as " medullary tube," there takes place at the same time, directly underneath, the severance of the chorda from the entoderm (Fig. 94, A, B, C). Under the chorda is formed (out of the ventral entodermic half of the Figs. 92 and 93.— Transverse section of ecelomula embryos of triton. (From Hertwig. This is done by the coalescence, under the chorda in the median line, of the two dorsal side-borders of the gut-gland-layer ( ik), which were previously separated by the chorda-plate (Fig. 94, A, c/t); these now alone form the clothing of the visceral cavity (dh ) (enteroderm, Fig. 94, C). All these important modifications take place at first in the fore or head-part of the embryo, and spread backwards from there ; here at the hinder end, the region of the primitive mouth, the important border of the mouth (or properistoma) One has only to compare carefully the illustrations given (Figs. 88 <»4) to see that, as a fact, the cenogenetic coelomation of the amphibia can be deduced directly from the palingenetic .!./..<. Vertical section of the dorsal part of three tritonembryos. (From Hertvig.) In Fig. .1 tlx- medullary swellings (the parallel borders of the medullary plate) begin to rise ; in Fig. 11 they grow towards each other; in Fig. C they join and form the medullary tube. >»/> medullary plate, m/medullary folds, n nerve-tube, ch chorda, iM body-cavity, mk, and mk., parietal and visceral mesoblasts, uv primitive-segmeni cavities, ai ectoderm, it entoderm, </- yelk-cells, dh gut-cavity. form of the acrania (Figs. 82-87). Hence Hertwig was quite right in formulating the following important thesis on the basis of this comparison : " The closing of the permanent gut at the dorsal side, the severance of the two body-sacs from the inner germinal layer, and the rise of the chorda dorsalis, are processes with the most intimate relations to each other, both in the amphibia and the amphioxus. Here also the severance of the said parts begins at the headextremity of the embryo, and proceeds slowly backwards, where for a long time a zone of new formation remains, by means of which the longitudinal growth of the body is effected." The same principle holds good for the amniotes, the three higher classes of vertebrates, although in this case the processes of ccelomation are more modified and more difficult to a lien's egg at the close of the first day of incubation). (From KSUiker.) h horn-plate (ectoderm), m medullary plate, vP/'dorsal folds of same, Pv medullary furrow, eh chorda, UTVp median (inner) part of the middle laver (median wall of the ccelom-pouches), sp lateral (outer) part of same, or lateral plates, ipmh structure of the body-cavity, dd gut-gland-layer. identify on account of the colossal accumulation of food-yelk and the corresponding notable flattening of the germinal disk. However, as the whole group of the amniotes has been developed at a comparatively late date from the class of the amphibia, their coelomation must also be directly traceable to that of the latter. This is really possible as a matter of fact ; even the older and more objective illustrations showed an essential identity of features. Thus forty years ago Kolliker gave, in the first edition of his Evolution of Man (1861), some sections of the chicken-embryo, the features of which could at once be reduced to those already described and explained in the sense of Hertwig's ccelom-theory. A section through the embryo of the hatched hen's egg towards the close of the first day of incubation shows in the middle of the dorsal surface a broad ectodermic medullary groove (Fig. <)> A' /). and underneath the middle of the chorda ( c// ) and at each side of it a couple of broad mesodermic layers (sp). These enclose a narrow space or cleft (uwh), which is nothing else than the structure of the body-cavity. The two layers that enclose it — the upper parietal layer ( ' Iipl ' ) and the lower visceral layer (df) — are pressed together from without, hut clearly distinguishable. This is even clearer a little later, when the medullar)- furrow is closed into the nerve-tube (Fig. 96 mr). Here the mesoderm has divided into two sections by a longitudinal fold, an inner (median) primitive-segment plate ( 'una ) and an outer (Lateral) plate; the narrow- ccelom-eleft may be seen both in the former (uwh) and the latter (nip). It afterwards enlarges into Fig. go. —Transverse section of the vertebrate-embryo of a bird (from a lien's egg on the second day of incubation I. ( From KSUiker. ) It hornplate, tnr medullary tube, ch chorda, //:.■ primitive segments, wwh primitive segment cavity (median relic of the caelom), sp lateral ccelom-cleft, hpl skinfibre-layer, df gut-fibre-layer, ung primitive-kidney pa^si^-, an primitive aorta, tUI gut-gland-layer. In this special importance attaches to the fact that here again the four secondary germinal layers are already sharply distinct, and easily separated from each other. There is only one very restricted area in which they are connected, and actually pass into each other ; this is the region o( the primitive mouth, which is contracted in the amniotes into a dorsal longitudinal cleft, the primitive groove. Its two lateral lip-borders form the primitive streak, which has long been recognised as the mosl important embryonic source and starting-point of further processes ( Remak's " axial plate"). Sections through this primitive streak (Figs. <)J and 98) show that the two primary germinal layers grow at an early stage (in the discogastrula of the chick, a few hours after incubation) into the primitive streak (x), and that the two middle layers extend outward from this thickened axial plate (y ) to the right and left between the former. The plates of the ccelom-layers, the parietal skin-fibre-layer (m) and the visceral gut-fibre-layer (~f), are seen to be still pressed close together, and only diverge later to form the body-cavity. Between the inner (median) borders of the two flat coelompouches lies the chorda (Fig. 98, .v), which here again developes from the middle line of the dorsal wall of the primitive gut. y If A T 1 Figs. 97 and 98.— Transverse section of the primitive streak (primitive mouth) of the ehiek. Fig. 97 a few hour alter the commencement of incubation, Fig. 98 a little later. (From Waldeyer.) h horn-plate, n nerveplate, 111 skin-fibre layer, /" gut-fibre-layer, d gut-gland-layer, y primitive streak or axial plate, in which all lour germinal layers meet, x structure of the chorda, 11 region of the later primitive kidneys. Ccelomation takes place in the vertebrates in just the same way as in the birds and reptiles. This was to be expected, as the characteristic gastrulation of the mammal has descended phylogenetically from that of the reptiles. In both cases a discogastrula with primitive streak arises from the segmented ovum, a two-layered germinal disk with long and small hinder primitive mouth. Here again the two primary germinal layers are only directly connected (Fig. 99 pr) along the primitive streak (at the invaginationpoint of the blastula), and from this spot (from the properistoma or border of the primitive mouth) the middle germinal layers mk) grow out to right and left between the preceding. In the fine illustration of the ccelomula o( the hare which Van Beneden has given us (Fig. 99) one can clearly sec that each of the four secondary germinal layers consists of a single stratum of cells. Finally, we must point out, as a fact of the utmost importance for our anthropogeny and of great general interest, that the four-layered ccelomula of man lias just the same construction as that of the hare (Fig. 99). A vertical section that Count Spec made through the primitive mouth or streak of a very young human germinal disk (Fig. 100) clearly shows that here again the four secondary germ-layers are only Fig. mo— Transverse section of the primitive groove (or primitive mouth) Of a hare. ( From Van Beneden. ) pr primitive mouth, id lips of same (primitive lip-.), at and ik outer and inner germinal layers, mk middle germinal layer, mp parietal layer, «;• visceral layer of the mesoderm. inseparably connected at the primitive streak, and that here also the two flattened ccelom-pouches (mk) extend centrifugally to right and left from the primitive mouth between the outer and inner germinal layers. In this case, too, the middle germinal layer consists from the first of two separate strata of cells, the parietal (mp ) and visceral (mv) mesoblasts. These concordant results of the best recent investigations (which have been confirmed by the observations of a number of scientists I have not enumerated) prove the unity of the vertebrate-stem in point of ccelomation, no less than of ^astrulation. In both respects the invaluable amphioxus — the sole living survivor ot the acrania — is found to be the original model that has preserved for us in palingenetic form by a tenacious heredity these most important embryonic processes. From this primary model of construction we can cenogenetically deduce all the embryonic forms of the other vertebrates, the craniota, by secondary modifications. My thesis of the universal formation of the gastrula by folding of the blastula has now been clearly proved for all the vertebrates ; so also has been Hertwig's thesis of the origin of the middle germinal layers by the folding of a couple of ccelompouches which appear at the border of the primitive mouth. Just as the gastraja-theory explains the origin and identity of the two primary layers, so the ccelom-theory explains those of the four secondary layers. The point of origin is always ik ui p Fig. i oo.— (From Count Spec.) pr primitive mouth, ul lips of same (primitive folds), ttk and ik outer and inner germinal layers, ink middle layer, inp parietal layer, /«;• visceral layer of the mesoblasts. into each other. Moreover, the coelomula is important as the immediate source of the chordula, the ontogenetic reproduction of the ancient, typical, unarticulated, vermalia-form, which has an axial chorda between the dorsal nerve-tube and the ventral gut-tube. This instructive chordula (Figs. 86-89) provides a valuable support of our phylogeny ; it indicates the important moment in our stem-history at which the stem of the chordoma (tunicates and vertebrates) parted for ever from the divergent stems of the other metazoa (articulates, echinoderms, and molluscs). I may express here my opinion, in the form of a chorckeatheory, that the characteristic chordula-larva of the ehordonia has in reality this great palingenetic significance — it is the typical reproduction (preserved by heredity) of the ancient common stem-form of all the vertebrates and tunieates, the long-extinct chordcea. We will return in the twentieth Chapter to these worm-like ancestors which stand out as luminous points in the obscure stem-history of the invertebrate ancestors of our race. (Cf. also the eighth and ninth Tables, as to the six fundamental organs and their functions in the chordaja.) N.B. The eighth and the ninth Tables are for the purpose of explaining my chordaea-theory, and giving a clear general view of the original anatomic and physiological properties of the chordaa, and also of the palingenetic relation of this ancient pre-Silurian stem-form to the corresponding structures in the human embryo. THE VERTEBRATE CHARACTER OF MAN The association of comparative anatomy and ontogeny. Place of man in zoological classification. The types or steins of the animal kingdom. The phvlogenetic relations of the twelve animal stems. Protozoa and metazoa. Coelenteria and ccelomaria. Unity of the vertebrate stem, including' man. Essential features of the vertebrates. Amphioxus and the hypothetical primitive vertebrate (prospondylus). Division of the simple bilateral body into head and trunk. Axial rod or chorda. The antimera or symmetrical halves of the body. Medullary tube or nerve tube (brain and spinal marrow). Three pairs of sense-organs (nose, eyes, ears \|. Chordasheath (perichorda). Muscles. Corium. Epidermis. Body-cavity. Alimentary canal. Gill-gut in the head-half of the body ; liver-gut in the trunkhalf. Gills and lungs. Stomach and small intestine. Liver. Blood-vessels and heart. Pro-kidneys (pronephridia). Segmental sex-organs (gonades). Metamerism or articulation of the vertebrates. Monophyletic origin of the vertebrates and of the mammals. The milk apparatus in mammals. Redundant milk glands and nipples. Hypermastism and hyperthelism. Gynecomastism (large milk-forming breast-glands in the male sex). Apparent hermaphrodism. We have now secured a number of firm standing-places in the labyrinthine course of our individual development by our study of the important embryonic forms which we have called the cytula, morula, blastula, gastrula, ccelomula, and chordula. But we have still in front of us the difficult task of deriving the complicated frame of the human body, with all its different parts, organs, members, etc., from the simple form of the chordula. We have previously considered the origin of this four-layered embryonic form from the twolayered gastrula. The two primary germinal layers, which form the entire body of the gastrula, and the two middle layers of the ccelomula that develop between them, are the four simple cell-strata or epithelia, which alone go to the formation of the complex body of man and the higher animals. It is so difficult to understand this construction that we will first seek a companion who may help us out of many difficulties. anatomy. Its task is, by comparing the fully-developed bodily tonus in the various groups of animals, to learn the general laws of organisation, according to which the body is constructed ; at the same time, it has to determine the affinities of the various groups by critical appreciation of the degrees oi difference between them. Formerly, this work was conceived in a teleological sense, and it was sought to find traces o\ the pre-formed plan of the Creator in the actual purposive organisation of animals. But comparative anatomy has gone much deeper since the establishment o( the theory of descent ; its philosophic aim now is to explain the variety of organic forms by adaptation, and their similarity by heredity. At the same time, it has to recognise in the shades o( difference in form the degree of blood-relationship, and make an effort to construct the ancestral tree of the animal world. In this way, comparative anatomy enters into the closest relations with comparative ontogeny on the one hand, and with the science of classification on the other. Now, when we ask wliat position man occupies among the other organisms according to the latest teaching of comparative anatomy and classification, and how man's place in the zoological system is determined by comparison of the developed bodily forms, we get a very definite and significant reply; and this reply gives us extremely important conclusions that enable us to understand the embryonic development and its phvlogenetic purport. Since Cuvier and Baer, since the immense progress that was effected in the early decades o\~ the nineteenth' century by these two great zoologists, the opinion has generally prevailed that the whole animal kingdom may be distributed in a small number of great divisions or types. They are called types because a certain typical or characteristic structure is constantly preserved within each of these large sections. Since we applied the theory ot descent to this doctrine of types, we have learned that this common type is an outcome o( heredity ; a the animals of one type are blood-relatives, or members of one stem, and can be traced to a common ancestral form. Cuvier and Baer set up four of these types : the vertebrates, articulates, molluscs, and radiates. The former three of these are still retained, and may be conceived as natural phylogenetic unities, as stems or phyla in the sense of the theory of descent.1 It is quite otherwise with the fourth type — the radiata. These animals, little known as yet at the beginning- of the nineteenth century, were made to form a sort of lumber-room, into which were cast all the lower animals that did not belong to the other three types. As we obtained a closer acquaintance with them in the course of the last sixty years, it was found that we must distinguish among them from four to eight different types. In this way the total number of animal stems or phyla has been raised to eight or twelve (cf. Chapter XX.). These twelve stems of the animal kingdom are, however, by no means co-ordinate and independent types, but have definite relations, partly of subordination, to each other, and a very different phylogenetic meaning. Hence they must not be arranged simply in a row one after the other, as was generally done until thirty years ago, and is still done in some manuals. We must distribute them in three subordinate principal groups of very different value, and arrange the various stems phylogenetically on the principles which I laid down in my Monograph on the Sponges, and developed in the Study of the Gastrcea Theory. We have first to distinguish the unicellular animals (protozoa) from the multicellular tissue-forming (metazoa J. Only the latter exhibit the important processes of segmentation and gastrulation ; and they alone have a primitive gut, and form germinal layers and tissues. The metazoa, the tissue-animals or gut-animals, then subdivide into two main sections, according as a body-cavity is or is not developed between the primary germinal layers. We may call these the ccetenteria and coelomaria ; the former 1 According to the early theory of types, those of the animal kingdom are parallel and completely independent ; but according- to my gastrfea theory they are divergent stems, connected at their root. This view of the affinity of the lower and higher animal-stems, which I first advanced in 1872 (in the Monograph on the Sponges ), is further developed in my Systematic Phytogeny (1896), and compendiously stated in the tenth edition of the History of Creation (1902). arc often also called zoophytes or coelenterata, and the latter bilaterals. This division is the more important as the ccelenteria (without COelom) have no blood and blood-vessels, or an anus. The coelomaria (with body-cavity) have generally an anus, and blood and blood-vessels. There are tour stems belonging to the ccelentejia : the gastrseads ("primitive-gut animals"), sponges, cnidaria, and platodes. Of the coelomaria we can distinguish six stems: the vermalia at the bottom represent the common stem-group (derived from the platodes) of these, the other five typical stems oi the coelomaria — the molluscs, echinoderms, articulates, tunicates, and vertebrates— being evolved from them. Man is, in his whole structure, a true vertebrate, and developes from an impregnated ovum in just the same characteristic way as the other vertebrates. There can no longer be the slightest doubt about this fundamental fact, nor ot the fact that all the vertebrates form a natural phylogenetic unity, a single stem. The whole of the members of this stem, from the amphioxus and the cyclostoma to the apes and man, have the same characteristic disposition, connection, and development of the central organs, and arise in the same way from the common embryonic form of the chordula. Without going into the difficult question of the origin of this stem, we must emphasise the fact that the vertebrate stem has no direct affinity whatever to five of the other ten stems ; these five isolated phyla are the sponges, cnidaria, molluscs, articulates, and echinoderms. On the other hand, there are important and, to an extent, close phylogenetic relations to the other five stems — the protozoa (through the amoeba?), the gastrseads (through the blastula and gastrula), the platodes and vermalia (through the ccelomula), and the tunicates (through the chordula). How we are to explain these phylogenetic relations in the present state o( our knowledge, and what place is assigned to the vertebrates in the animal ancestral tree, will be considered later (Chapter XX.). For the present our task is to make plainer the vertebrate character of man, and especial ly to point out the chief peculiarities of organisation by which the vertebrate stem is profoundly separated from the other eleven stems of the animal kingdom. Only after these comparative anatomical considerations shall we be in a position to attack the difficult question of our embryology. The development of even the simplest and lowest vertebrate from the simple chordula (Figs. 86-89) is so complicated and difficult to follow that it is necessary to understand the organic features of the fully-formed vertebrate in order to grasp the course of its embryonic evolution. But it is equally necessary to confine our attention, in this general anatomic characterisation of the vertebrate-body, to the essential facts, and pass by all the unessential. Hence, in giving you now an ideal anatomic description of the chief features of the vertebrate and its internal organisation, I omit all the subordinate points and restrict myself to the most important characteristics. Much, of course, will seem to the reader to be essential that is only of subordinate and secondary interest, or even not essential at all, in the light of comparative anatomy and embryology. For instance, the skull and vertebral column and the extremities are non-essential in this sense. It is true that these parts are very important physiologically ; but for the morphological conception of the vertebrate they are not essential, because they are only found in the higher, not the lower, vertebrates. The lowest vertebrates have neither skull nor vertebra?, and no extremities or limbs. Even the human embryo passes through a stage in which it has no skull or vertebra;; the trunk is quite simple, and there is yet no trace of arms and legs. At this stage of development man, like every other higher vertebrate, is essentially similar to the simplest vertebrate form, which we now find in only one living specimen. This one lowest vertebrate that merits the closest study — undoubtedly the most interesting of all the vertebrates after man — is the famous lancelet or amphioxus, to which we have already often referred (Plates XVIII. and XIX.). As we are going to study it more closely later on (Chapters XVI. and XVII.), I will only make one or two passing observations on it here. The amphioxus lives buried in the sand of the sea, is from g 7 centimetres long, and has, when fully developed, the shape o( a very simple, longish, lancet-like leaf; hence its name of the laneelet. The narrow body is compressed on both sides, almost equally pointed at the fore and hind ends, without any traee of external appendages or articulation of the body into head, neck, breast, abdomen, etc. Its whole shape is so simple that its first discoverer thought it was a naked snail. It was not until much later — half a century ago — that the tiny creature was studied more carefully, and was found to be a true vertebrate. More recent investigations have shown that it is of the greatest importance in connection with the comparative anatomy and ontogeny of the vertebrates, and therefore witli human phylogeny. The amphioxus reveals the great secret of the origin of the vertebrates from the invertebrate vermalia, and in its development and structure connects directly with certain lower tunicates, the ascidia. When we make a number of sections of the body of the amphioxus, firstly vertical longitudinal sections through the whole body from end to end, and secondly transverse sections from right to left, wc get anatomic pictures of the utmost instructiveness (cf. Figs. 101-105 and Plates XVIII. and XIX.). In the main they correspond to the ideal which we form with the aid of comparative anatomy and ontogeny ot the primitive type or build of the vertebrate — the long extinct form to which the whole stem owes its origin. As we take the phylogenetic unity of the vertebrate stem to be beyond dispute, and assume a common origin from a primitive stem-form for all the vertebrates, from amphioxus to man, wc are justified in forming a definite morphological idea of this primitive vertebrate ( prospondylus or vcrlebnva ). Wc need only imagine a few slight and unessential changes in the real sections of the amphioxus in order to have this ideal anatomic figure or diagram of the primitive vertebrate form, as we see in bigs. 101-105. The amphioxus departs so little from this primitive form that we may, in a certain sense, describe il The outer form of our hypothetical primitive vertebrate was at all events very simple, and probably more or less similar to that of the lancelet. The bilateral or bilateralsymmetrical body is stretched out lengthways and compressed at the sides (Figs. 101-103), oval in section (Figs. 104, 105). There are no external articulation and no external appendages, in the shape of limbs, legs, or fins. On the other hand, the division of the body into two sections, head and trunk, was probably clearer in prospondylus than it is in its littlechanged ancestor, the amphioxus. In both animals the fore or head-half of the body contains different organs from the trunk, and different on the dorsal from on the ventral side. As this important division is found even in the ascidia, the remarkable invertebrate stem-relatives of the vertebrates, we may assume that it was also found in the prochordonia, the common ancestors of both stems. It is also very pronounced in the young larva? of the cyclostoma (Plate XIX., Fig. 16); this fact is particularly interesting, as this palingenetic larvaform is in other respects also an important connecting-link between the higher vertebrates and the acrania. The head of the acrania, or the anterior half of the body (both of the real amphioxus and the ideal prospondylus), contains the gill-gut and heart in the ventral section and the brain and sense-organs in the dorsal section. The trunk, or posterior half of the body, contains the liver-gut and sexualglands in the ventral part, and the spinal marrow and most of the muscles in the dorsal part. 1 The ideal figure of the vertebrate as given in Figs. 101-105 's a hypothetical scheme or diagram, that has been chiefly constructed on the lines of the amphioxus, but with a certain attention to the comparative anatomy and ontogeny of the ascidia and appendicularia on the one hand, and of the cyclostoma and selachii on the other. This diagram has no pretension whatever to be an "exact picture," but merely an attempt to reconstruct hypothetieally the unknown and long extinct vertebrate stem-form, an ideal " architypus. " Figs. 101-105.— The ideal primitive vertebrate (prospondylus). Diagram. Fig. 101 side-view (from the left). Fig. 102 back-view. Fig. 103 front view. Fig. 104 transverse section It goes the whole length through the middle of the body, and forms, as the central skeletal axis, the original structure of the later vertebral column. This is the axial rod, or chorda dorsal is, also called chorda vertcbralis, vertebral cord, axial cord, spinal cord, notochorda, or, briefly, chorda. This solid, but flexible and elastic, axial rod consists of a cartilaginous mass of cells, and forms the inner axial skeleton or central frame of the body ; it is only found in vertebrates and tunicates, not in any other animals. As the first structure of the spinal column it has the same radical significance in all vertebrates, from the amphioxus to man. But it is only in the amphioxus and the cyclostoma that the axial rod retains its simplest form throughout life. In man and all the higher vertebrates it is found only in the earlier embryonic period, and is afterwards replaced by the articulated vertebral column. The axial rod or chorda is the real solid chief axis of the vertebrate body, and at the same time corresponds to the ideal long-axis, and serves to direct us with some confidence in the orientation of the principal organs. We therefore take the vertebrate-body in its original, natural disposition, in which the long-axis lies horizontally, the dorsal side upward and the ventral side downward (Fig. 101). When we make a vertical section through the whole length of this long-axis, the body divides into two equal and symmetrical halves, right and left. In each half we have originally the same organs in the same disposition and connection; only their disposal in relation to the vertical plane of section, or median plane, is exactly reversed : the left half is the reflection of the right. We call the two halves antimera (opposed-parts). In the vertical plane of section that divides the two halves the sagittal ("arrow") axis, or "dorsoventral axis," goes from the back to the belly, corresponding to the sagittal seam of the skull. But when we make an horizontal longitudinal section through the chorda, the whole body divides into a dorsal and a ventral half. The line of section that passes through the body from right to left is the transverse, frontal, or lateral axis (cf. Plates VI. and VII.). by this horizontal transverse axis and by the chorda are of quite different characters. The dorsal half is mainly the animal part of the body, and contains the greater part of what are called the animal organs, the nervous system, muscular system, osseous system, etc. — the instruments of movement and sensation. The ventral half is essentially the vegetative half o\ the body, and contains the greater part of the vertebrate's vegetal organs, the visceral and vascular systems, sL-\ual system, etc. — the instruments of nutrition and reproduction. Hence in the construction of the dorsal half it is chiefly the outer, and in the construction of the ventral half chiefly the inner, germinal layer that is engaged. Each o( the two halves developes in the shape of a tube, and encloses a cavity in which another tube is found. The dorsal hall contains the narrow spinal-column cavity or vertebral canal above the chorda, in which lies the tube-shaped central nervous system, the medullary tube. The ventral half contains the much more spacious visceral cavity or bodycavity underneath the chorda, in which we find the alimentary canal and all its appendages. The medullary tube, as the central nervous system or psychic organ of the vertebrate is called in its first stage, consists, in man and all the higher vertebrates, of two different parts : the large brain, contained in the skull, and the long spinal cord which stretches from there over the whole dorsal part of the trunk (Plate VII., Figs, n-16 n). Even in the primitive vertebrate this composition is plainly indicated. The fore half of the body, which corresponds to the head, encloses a knob-shaped vesicle, the brain (g/i); this is prolonged backwards into the thin cylindrical tube of the spinal marrow ( r ). Hence we find here this very important psychic organ, which accomplishes sensation, will, and thought, in the vertebrates, in its simplest form. The thick wall of the nerve-tube, which runs through the long axis of the body immediately over the axial rod, encloses a narrow central canal filled with fluid (Figs. 101-105 r). We still find the medullary tube in this verv simple form for a time in the embryo of all the vertebrates (cf. Plate VII., Figs. 11-13), and it retains this form in the amphioxus throughout life ; only in the latter case the cylindrical medullary tube barely indicates the separation of brain and spinal cord. The lancelet's medullary tube runs nearly the whole length of the body, above the chorda, in the shape of a long thin tube of almost equal diameter throughout (Plate XIX., Fig. 15), and there is only a slight swelling of it right at the front to represent the rudiment of a cerebral lobe. It is probable that this peculiarity of the amphioxus is connected with the partial atrophy of its head, as the ascidian larva? (Plate XVIII., Fig. 5) on the one hand and the young cyclostoma (Plate XIX. , Fig. 16) on the other clearly show a division of the vesicular brain, or head-marrow, from the thinner, tubular spinal marrow. Probably we must trace to the same phylogenetic cause the defective nature of the sense-organs of the amphioxus, which we will describe later (Chapter XVI.). There was also, perhaps, a single parietal or " pineal " eye at the top of the skull (epiphysis, e ). In the vertical median plane (or middle plane, dividing the bilateral body into right and left halves) we have in the acrania, underneath the chorda, the mesentery and visceral tube, and above it the medullary tube ; and above the latter a membranous partition of the two halves or antimera of the body. With this partition is connected the mass of connective tissue which acts as a sheath both for the medullary tube and the underlying chorda, and is, therefore, called the chord-sheath (perichorda) ; it originates from the dorsal and median part of the ccelom-pouches which we shall call the skeleton plate or " sclerotom " in the craniote embryo. In the latter the chief part of the skeleton — the vertebral column and skull — developes from this chord-sheath ; in the acrania it retains its simple form as a soft connective matter, from which are formed the membranous partitions between the various muscular plates or myotomes (Figs. 101, 102, ms). To the right and left of the cord-sheath, at each side of the medullary tube and the underlying axial rod, we find in all the vertebrates the large masses of muscle that constitute the musculature of the trunk and effect its movements. Although these are very elaborately differentiated and connected in the developed vertebrate (corresponding to the many differentiated parts of the bony skeleton), in our ideal primitive vertebrate we can distinguish only two pairs of these principal muscles, which run the whole length of the body parallel to the chorda. These are the upper (dorsal) and lower (ventral) lateral muscles of the trunk. The upper (dorsal) muscles, or the original dorsal muscles (Fig. 105 ms), form the thick mass of flesh on the back. The lower (ventral) muscles, or the original muscles of the belly, form the fleshy wall of the abdomen. Both sets are articulated, and consist of a double row of muscular plates (Figs. 101, 102 //is); the number of these myotomes determines the number of joints in the trunk, or metamera. The myotomes are also developed from the thick wall of the coelom-pouches (Fig. 105 /). Outside this muscular tube we have the external envelope of the vertebrate body, which is known as the corium or cutis ( Plate VI. /). This strong and thick envelope consists, in its deeper strata, chiefly of fat and loose connective tissue, and in its upper layers of cutaneous muscles and firmer connective tissue. It covers the whole surface of the fleshy body, and is of considerable thickness in all the craniota. But in the acrania the corium is merely a thin plate of connective tissue, an insignificant " corium-plate " (lamella con'/, Figs. 101-105 I )• Immediately above the corium is the outer skin (epidermis, a), the general covering of the whole outer surface. In the higher vertebrates the hairs, nails, feathers, claws, scales, etc., grow out of this epidermis. It consists, with all its appendages and products, of simple cells, and has no bloodvessels. Its cells are connected with the terminations of the sensory nerves. Originally, the outer skin is a perfectly simple covering of the outer surface of the body, composed only of homogeneous cells — a permanent horn-plate. In this simplest form, as one-layered epithelium, we find it, at first, in all the vertebrates, and throughout life in the acrania. It afterwards grows thicker in the higher vertebrates, and divides into two strata — an outer, firmer horn-layer and an inner, softer mucus-layer ; also a number of external and internal appendages grow out of it : outwardly, the hairs, nails, claws, etc., and internally, the sweat-glands, fatglands, etc. It is probable that in our primitive vertebrate the skin was raised in the middle line of the body in the shape of a vertical fin border (fj. A similar border, going round the greater part of the body, is found to-day in the amphioxus and the cyclostoma ; we also find one in the tail of fish-larva? and tadpoles. Now that we have considered the external parts of the vertebrate and the animal organs, which mainly lie in the dorsal half, above the chorda, we turn to the vegetal organs, which lie for the most part in the ventral half, below the axial rod. Mere we find a large body-cavity or visceral cavity in all the craniota. The spacious cavity that encloses the greater part of the viscera corresponds to only a part of the original cceloma, which we considered in the tenth Chapter ; hence it may be called the metacosloma. As a rule, it is still briefly called the cceloma ; formerly it was known in anatomy as the pleuroperitoneal cavity. In man and the other mammals (but only in these) this cceloma divides, when fully developed, into two different cavities, which are separated by a transverse partition — the muscular diaphragm. The fore or pectoral cavity (pleura cavity) contains the oesophagus, heart, and lungs ; the hind or peritoneal or abdominal cavity contains the stomach, small and large intestines, liver, pancreas, kidneys, etc. But in the vertebrate embryo, before the diaphragm is developed, the two cavities form a single continuous body-cavity, and we find it thus in all the lower vertebrates throughout life. This body-cavity is clothed with a delicate layer of cells, the ccelomepithelium. In the acrania the ccelom is articulated both dorsal ly and ventrally, as their muscular pouches and primitive genital organs plainly show (Fig. 105). The chief o( the viscera in the body-cavity is the alimentary canal, the organ that represents the whole body in the gastrula. In all the vertebrates it is a long tube, enclosed in the body-cavity and more or less differentiated in length, and has two apertures — a mouth for taking in food (Figs. 101, to,'', /in/) and an anus for the ejection of unusable matter or excrements (a/). With the alimentary canal (Plates IV., Y. </) a number of glands are connected which are of great importance for the vertebrate body, and which all grow out of the canal. Glands of this kind are the salivary glands, the lungs, the liver, and many smaller glands. Nearly all these glands are wanting in the acrania ; probablv there were merely a couple of simple hepatic tubes (Figs. 101, 103 /) in the vertebrate stem-form. The wall of the alimentary canal and all its appendages consists of two different layers; the inner, cellular clothing is the gut-gland-laver, and the outer, fibrous envelope consists of the gut-fibre-layer; it is mainly composed o\ muscular fibres which accomplish the digestive movements of the canal, and of connective-tissue fibres that form a firm envelope. We have a continuation of it in the mesentery, a thin, bandage-like layer, by means of which the alimentary canal is fastened to the ventral side of the chorda, originally the dorsal partition oi the two ccdom-pouches (Plate VI., Fig. 8 /). The alimentary canal is variously modified in the vertebrates both as a whole and in its several sections, though the original structure is always the same, and is very simple. As a rule, it is longer (often several times longer) than the body, and therefore folded and winding within the body-cavity, especially at the lower end. In man and the higher vertebrates it is divided into several sections, often separated by valves— the mouth, pharynx, oesophagus, stomach, small and large intestine, and rectum. All these parts develop from a very simple structure, which originally (throughout life in the amphioxus) runs from end to As the alimentary canal may be regarded morphologically as the oldest and most important organ in the body, it is interesting to understand its essential features in the vertebrate more fully, and distinguish them from unessential features. In this connection we must particularly note that the alimentary canal of every vertebrate shows a very characteristic division into two sections — a fore and a hind chamber. The fore chamber is the head-gut or branchial gut (Figs. 101-103, p, k), and is chiefly occupied with respiration. The hind section is the trunk-gut or hepatic gut, which accomplishes digestion (ma, d '). In all vertebrates there are formed, at an early stage, to the right and left in the fore-part of the head-gut, certain special clefts that have an intimate connection with the original respiratory apparatus of the vertebrate — the branchial (gill) clefts (ksj. All the lower vertebrates, the amphioxus, lampreys, and fishes, are constantly taking in water at the mouth, and letting it out again by the lateral clefts of the gullet. This water serves for breathing. The oxygen contained in it is inspired by the blood-canals, which spread out on the parts between the gillclefts, the gill-arches (kg). These very characteristic branchial clefts and arches are found in the embryo of man and all the higher vertebrates at an early stage of development, just as we find them throughout life in the lower vertebrates (Plates VIII. -XIII.). However, these clefts and arches never act as respiratory organs in the mammals, birds, and reptiles, but gradually develop into quite different parts. Still, the fact that they are found at first in the same form as in the fishes is one of the most interesting proofs of the descent of these three higher classes from the fishes. Not less interesting and important is an organ that developes from the ventral wall in all vertebrates — the gillgroove or hypobranchial-groove. In the acrania and the ascidia it consists throughout life of a glandular ciliated groove, which runs clown from the mouth in the ventral middle line of the gill-gut, and takes small particles of food to the stomach (Fig. 104 2). But in the c ran iota the thyroid gland (thyreoidea) is developed from it, the gland From the head-gut we get not only the gills, the organs o( water-breathing in the lower vertebrates, but also the lungs, the organs of atmospheric breathing in the live higher classes. In these cases a vesicular fold appears in the gullet of the embryo at an early stage, and gradually takes the shape of two spacious sacs, which are afterwards rilled with air. These sacs are the two air-breathing lungs, which take the place of the water-breathing gills. But the vesicular invagination, from which the lungs arise, is merely the familiar air-filled vesicle, which we call the floatingbladder of the fish, and which alters its specific weight as hydrostatic organ or floating apparatus. This structure is not found in the lowest vertebrate classes — the acrania and cyelostoma. The second chief section of the vertebrate-gut, the trunk or liver-gilt, which accomplishes digestion, is of very simple construction in the acrania. It consists of two different chambers. The first chamber, immediately behind the gillgut, is the expanded stomach (ma); the second, narrower and longer chamber, is the straight small intestine (d) : it opens behind on the ventral side by the anus (af). Near the limit of the two chambers in the visceral cavity we find the liver, in the shape of a simple tube or blind sac (I); in the amphioxus it is single (Plate XIX., Fig. 15 lb) ; in the prospondylus it was probably double (Figs. 101, 103 /). Closely related morphologically and physiologically to the alimentary canal is the vascular system of the vertebrate, the chief sections of which develop from the fibrous gut-layer. It consists o( two different but directly connected parts, the system o\ blood-vessels and that of lymph-vessels. In the passages of the one we find red blood, and in the other colourless lymph. To the lymphatic system belong, first of all, the lymphatic canals proper or absorbent veins, which are distributed among all the organs, and absorb the used-up juices from the tissues, and conduct them into the venous blood ; but besides these there are the chyle-vessels, which absorb the white chyle (or milk-juice), the nutritive fluid prepared by the alimentary canal, and conduct this also to the blood. The blood-vessel system of the vertebrate has a very elaborate construction, but seems to have had a very simple form in the primitive vertebrate, as we find it to-day permanently in the ringed-worms (for instance, rain-worms) and the amphioxus. We accordingly distinguish first of all as essential, original parts of it two large single blood-canals, which lie in the fibrous wall of the gut, and run along the alimentary canal in the median plane of the body, one above and the other underneath the canal. These principal canals give out numerous branches to all parts of the body, and pass into each other by arches before and behind ; we will call them the primitive artery and the primitive vein. The first corresponds to the dorsal vessel, the second to the ventral vessel, of the worms. The primitive or principal artery, usually called the aorta (Fig. 101 a), lies above the gut in the middle line of its dorsal side, and conducts oxidised or arterial blood from the gills to the body. The primitive or principal vein (Fig. 103 7>) lies below the gut, in the middle line of its ventral side, and is therefore also called the vena subintestinalis ; it conducts carbonised or venous blood back from the body to the gills. At the branchial section of the gut in front the two canals are connected by a number of branches, which rise in arches between the gill-clefts. These " branchial vascular arches " (kg) run along the gill-arches, and have a direct share in the work of respiration. The anterior continuation of the principal vein which runs on the ventral wall of the gill-gut, and gives off these vascular arches upwards, is the branchial artery (ka). At the border of the two sections of the ventral vessel it enlarges into a contractile spindle-shaped tube (Figs. 101, 103 h). This is the first outline of the heart, which afterwards becomes a fourchambered pump in the higher vertebrates and man. There is no heart in the amphioxus, probably owing to degeneration. In prospondylus the ventral gill-heart probably had the simple form in which we still find it in the ascidia and the embryos of the craniota (Figs. 101, 10,} h). The kidneys, which act as organs of excretion or urinary organs in all vertebrates, have a very different and elaborate construction in the sections of this stem; we will consider them further in the twenty-ninth Chapter. Here I need only mention that in our hypothetical primitive vertebrate they probably had the same form as in the actual amphioxus — the fore-kidneys (protonephra). These are originally made up of a double row ot little canals, which directly convey the used-up juices or the urine out of the body-cavity (Fig. 105 //). The inner aperture of these pronephridial canals opens with a vibratory funnel into the body-cavity ; the external aperture opens in lateral grooves of the epidermis, a couple of longitudinal grooves in the lateral surface of the outer skin (Fig. 105 b). The pronephridial duct is formed by the closing of this groove to the right and left at the sides. In all the craniota it developes at an early stage in the hornplate (Plate VI., Figs. 4 a, 5 u) ; in the amphioxus it seems to be converted into a wide cavity, the atrium, or pcribranchial space (Plate XV I II., Fig. 13 c). Xext to the kidneys we have the sexual organs of the vertebrate. In most of the members of this stem the two are joined together in a unified urogenital system ; it is only in a few groups that the urinary and sexual organs are separated (in the amphioxus, the cyclostoma, and some sections of the fish-class). In man and all the higher vertebrates the sexual apparatus is made up of various parts, which we will consider in the twenty-ninth Chapter. But in the two lowest classes of our stem, the acrania and cyclostoma, they consist merely of simple sexual glands or gonades, the ovaries of the female sex and the testicles (spermatid) of the male ; the former provide the ova, the latter the sperm. In the craniota we alwavs find only one pair of gonades; in the amphioxus several pairs, metamerically arranged. They must have had the same form in our hypothetical prospondylus (Figs. 101, 10,-5 •»")• The organs which we have now enumerated in this general survey, and of which we have noted the characteristic disposition, are those parts of the organism that are found in all vertebrates without exception in the same relation to each other, however much they may be modified. We have chiefly had in view the transverse section of the body (Figs. 104, 105), because in this we see most clearly the distinctive arrangement of them. But to complete our picture we must also consider the articulation or metameraformation of them, which has yet been hardly noticed, and which is seen best in the longitudinal section. In man and all the more advanced vertebrates the body is made up of a series or chain of similar members, which succeed each other in the long axis of the body — the segments or metamera of the organism. In man these homogeneous parts number thirtv-three in the trunk, but they run to several hundred in many of the vertebrates (such as serpents or eels). As this internal articulation or metamerism is mainly found in the vertebral column and the surrounding muscles, the sections or metamera were formerly called pro-vertebrae. As a fact, the articulation is by no means chiefly determined and caused by the skeleton, but by the muscular system and the segmental arrangement of the kidneys and gonades. However, the composition from these pro-vertebrae or internal metamera is usually, and rightly, put forward as a prominent character of the vertebrate, and the manifold division or differentiation of them is of great importance in the various groups of the vertebrates. But as far as our present task — the derivation of the simple body of the primitive vertebrate from the ehordula — is concerned, the articulate parts or metamera are of secondary interest, and we need not go into them just now. The characteristic composition of the vertebrate body developes from the embryonic structure in the same way in man as in all the other vertebrates. As all competent experts now admit the monophyletic origin of the vertebrates on the strength o( this significant agreement, and this "common descent of all the vertebrates from one original Stem-form " is admitted as an historical fact, we have found the answer to " the question of all questions." We may, moreover, point out that this answer is just as certain and precise in the case of the origin of man from the mammals. This advanced vertebrate class is also monophyletic, or has evolved from a common stem-group of lower vertebrates (reptiles, and, earlier still, amphibia). This follows from the fact that the mammals are clearly distinguished from the other classes of the stem, not merely in one striking particular, hut in a whole group of distinctive characters. It is only in the mammals that we find the skin covered with hair, the breast-cavitv separated from the abdominal cavity by a complete diaphragm, and the larynx provided with an epiglottis. The mammals alone have three small auscultory bones in the tympanic cavity — a feature that is connected with the characteristic modification of their maxillary joint. Their red blood-cells have no nucleus, whereas this is retained in all other vertebrates. Finally, it is only in the mammals that we find the remarkable function of the breast-structure which has given its name to the whole class — the feeding of the young by the mother's milk. The mammary glands which serve this purpose are interesting in so many ways that we may devote a few lines to them here. As is well known, the lower mammals, especially those which beget a number of young at a time, have several mammary glands at the breast. Hedge-hogs and sows have five pairs, mice four to the pairs, dogs and squirrels four pairs, cats and bears three pairs, most of the ruminants and many of the rodents two pairs, each provided with a teat or nipple ( maslos ). In the various genera of the half-apes (lemures) the number varies a good deal. On the other hand, the bats and apes, which only beget one young at a time as a rule, have only one pair of mammary glands, and these are found at the hrca^t as in man. mammary apparatus ( mammarium ) have become doubly interesting in the light of recent research in comparative anatomy. It has been shown that in man and the apes we often find redundant mammary glands (hypermastism) and nipples^ hypermastism ). As. pair of small redundant breasts (with two nipples on the left) above the large normal ones; from a 45-year-old Berlin woman, who had had children 17 times (twins twice). (From Hansemann.) B the highest number: ten nipples (all giving milk), three pairs above, one pair below, the large normal breasts ; from a 22-year-old servant at Warschau. (From Netigebaur.) C three pairs of nipples : two pairs on the normal glands and one pair above; from a 19-year-old Japanese maiden. D four pairs of nipples: one pair above the normal and two pairs of small accessory nipples underneath; from a 22-year-old Baden soldier. (From Wicderslnim.) corresponding teats (hyperllielism) in both sexes. Fig. 106 shows four cases of this kind — A, B, and Cof three women, and D of a man. They prove that all the above-mentioned numbers may be found occasionally in man. Fig. 106 A shows the breast of a Berlin woman who had had children seventeen times, and who has a pair of small accessory breasts (with two nipples on the left one) above the two normal breasts; this is a common occurrence, and the small soft pad abo\e the breast is not infrequently represented in ancient statues of Venus. In Fig. 106 C we have the same phenomenon in a Japanese girl o\~ nineteen, who has two nipples on each breast besides (three pairs altogether). Fig. 106 D is a man of twenty-two with four pairs of nipples (as in the dog), a small pair above and two small pairs beneath the large normal teats. The maximum number oi five pairs (as in the pig and hedge-hog) was found in a Polish servant of twenty-two who had had several children ; milk was given by each nipple ; there were three pairs of redundant nipples above and one pair underneath the normal and very large breasts (Fig. 106 B). A number of recent investigations (especially among recruits) have shown that these things arc not uncommon in the male as well as the female sex. They can only be explained by phylogeny, which attributes them to atavism and latent heredity. The earlier ancestors of all the primates (including man) were lower placentals, which had, like the hedge-hog (one of the oldest forms of the living placentals), several mammary glands (five or more pairs) in the abdominal skin. In the apes and man only a couple of them are normally developed, but from time to time we get a development of the atrophied structures. Special notice should be taken of the arrangement of these accessory mammae ; they form, as is clearly seen in Fig. 106 B and /), two long rows, which diverge forward (towards the arm-pit), and converge behind in the middle line (towards the loins). The milk-glands of the polymastic lower placentals are arranged in similar lines. The phylogenetie explanation of polymastism, as given in comparative anatomy, has lately found considerable support in ontogeny. Hans Strahl, E. Schmitt, and others, have found that there are always in the human embryo at the sixth week (when it is 15 mm. long) the microscopic traces of five pairs of mammary glands, and that they are arranged at regular distances in two lateral and divergent lines, which Correspond to the mammary lines. Only one pair of them — the central pair — are normally developed, the others atrophying. Hence there is for a time in the human embryo a normal hyperthelism, and this can only be explained by the descent of man from polvthelic lower primates (lemures). But the milk-gland of the mammal has a great morphological interest from another point of view. This organ for feeding the young in man and the higher mammals is, as is known, found in both sexes. However, it is usually active only in the female sex, and yields the valuable " mother's milk"; in the male sex it is small and inactive, a real rudimentary organ of no physiological interest. Nevertheless, in certain cases we find the breast as fully developed in man as in woman, and it may give milk for feeding the young. We have a striking instance of this gynecomastism (large milk-giving breasts in a male) in Fig. 107. I owe the photograph (taken from life) to the kindness of Dr. Ornstein, of Athens, a German physician, who has rendered service by a number of anthropological observations (for instance, in several cases of tailed men). The gynecomast in question is a Greek recruit in his twentieth vear, who has both normally developed male organs and a very pronounced female breast. It is noteworthy that the other features of the structure are in accord with the softer forms of the female sex. It reminds us of the marble statues of hermaphrodites which the ancient Greek and Roman sculptors often produced. Hut the man would only be a real hermaphrodite if he had ovaries internally besides the (externally visible) testicles. I observed a very similar case during my stay in Ceylon (at Belligemnia) in 188 1. A young Cinghalese in his twentyfifth year was brought to me as a curious hermaphrodite, halfman and half-woman. The outline of his body was softer and more feminine than in the Greek shown in Fig. 107. As the Cinghalese are small o( stature and of graceful build, and as the men often resemble the women in clothing (upper part of the body naked, female dress on the lower part) and the dressing of the hair (with a comb), I first took the beardless youth to be a woman. The illusion was greater, as in this remarkable case gynecomastism was associated with cryptorchism — that is to say, the testicles had kept to their original place in the visceral cavity, and had not travelled in the normal way down into the scrotum. (Cf. Chapter XXIX.) Hence the latter was very small, soft, and empty. Moreover, one could feel nothing of the testicles in the inguinal canal. On the other hand, the male organ was very small, but normally developed (as in Fig. 107). It was clear that this apparent hermaphrodite also was a real male. Another case of practical gynecomastism has been described by Alexander von Humboldt. In a South American forest he found a solitary settler whose wife had ■died in child-birth. The man had laid the new-born child on his own breast in despair ; and the continuous stimulus of the child's sucking movements had revived the activity of the mammary glands. It is possible that nervous suggestion had some share in it. Similar cases have been often observed in recent years, even among other male mammals (such as sheep and goats). The great scientific interest of these facts is in their bearing on the question of heredity. The stem-history of the mammarium rests partly on its embryology (Chapter XXIV.) and partly on the facts of comparative anatomy and physiology. As in the lower and higher mammals (the monotremes, and most of the marsupials) the whole lactiferous apparatus is only found in the female ; and as there are traces of it in the male only in a few younger marsupials, there can be no doubt that these important organs were originally found only in the female mammal, and that ihey were acquired by these through a special adaptation to habits of life. active in the males. This normal permanence of the female lactiferous organs in both sexes of the higher mammals and man is independent of any selection, and is a fine instance of the much-disputed " inheritance of acquired characters." 10. A. Skeleton and muscles of the gill-arches (visceral skeleton ). 10. B. Muscular wall of the hepatic EMBRYONIC SHIELD AND GERMINATIVE AREA Cenogenetic characteristics of amniote embryology. The classic hen's egg as .1 source of error. False antithesis of germ and yelk. The yolk belongs to the vegetal half. Yelk-germ and yelk-glajids of the amphibia. Flal germinal disk o',' the birds and reptiles. Severance of it from the yelk-sac. Primary, secondary, and tertiary embryonic si tges of the vertebrate. The so-called blastula of the mammal (germinal gut-vesicle or blastocyst). Its origin by modification of the feeding of the young. Descent of the viviparous mammals from oviparous. Envelopes of their epigastrula (covering layer). Conversion of the two-layered into the four-layered germinal disk. Dark and tight germinative area. Embryonic shield ( embryaspis ) or dorsal shield ( notaspis), embryonic formation. Relation of the germinative area to the permanent gut (menosoma). The continued inheritance and subsequent loss of the food-yelk in the vertebrates. Influence of these cenogenetic processes on the modification of the gastrula. THE three higher classes of vertebrates which we call the amniotes — the mammals, birds, and reptiles — are notably distinguished by a number of peculiarities of their development from the five lower classes of the stem — the animals without an amnion (anamnia or ichthyopoda). All the amniotes have a distinctive embryonic membrane known as the amnion (or " water-membrane "), and a special embryonic appendage — the allantois. They have, further, a considerable yelk-sac, which is filled with food-yelk in the reptiles and birds, and with a clear corresponding fluid in the mammals. In consequence of these cenogenetic structures, the original features of the development of the amniotes are so much altered that it is very difficult to reduce them to the pa j ingenetic embryonic processes of the lower amnion-less vertebrates. The gastraea theory shows us how to do this, by representing the embryology of the lowest vertebrate, the skull-less amphioxus, as the original form, and deducing from it, through a series oi gradual modifications, the gastrulation and ceelomation of the craniota. embryonic processes of the vertebrate that all the older embryologists, from Malpighi (1687) and Wolff (1750) to Baer (182S) and Remak (1S50), always started from the investigation of the hen's egg, and transferred to man and the other vertebrates the impressions they gathered from this. This classical object of embryological research is, as we have seen, a source of dangerous errors. The large globular food-yelk of the bird's egg causes, in the first place, a flat discoid expansion of the small gastrula, and then so distinctive a development of this thin round embryonic disk that the controversy as to its significance occupies a large part of embryological literature. One of the most unfortunate errors that this led to was the idea of an original antithesis of germ and yelk. The latter was regarded as a foreign body, extrinsic to the real germ, whereas it is really a part of it, an embryonic organ of nutrition. Many authors said there was no trace of the embryo until a later stage, and outside the yelk ; sometimes the two-layered embryonic disk itself, at other times only the central axial portion of it (as distinguished from the germinative area which we will describe presently) was taken to be the first outline of the embryo. In the light of the gastraea theory it is hardly necessary to dwell on the defects of this earlier view and the erroneous conclusions drawn from it. In reality, the first segmentation-cell, and even the stem-cell itself and all that issues therefrom, belong to the embryo. As the large original yelk-mass in the undivided egg of the bird only represents an inclosure in the greatly enlarged ovum, so the later content of its embryonic yelk-sac (whether yet segmented or not) is only a part of the entoderm which forms the primitive gut. This is clearly shown by the amphiblastic ova of the amphibia and cyclostoma, which explain the transition from the archiblastic yelk-less ova of the amphioxus to the large yelk-filled ova of the reptiles and birds. It is precisely in the study of these difficult features that we see the incalculable value of phylogenetic considerations in explaining complex ontogenetic facts, and the need of separating cenogenetic phenomena from palingenetic. This is particularly clear as regards the comparative ontogeny of the vertebrates, because here the phylogenetic unity of the stem has been already established by the well-known facts of paleontology and comparative anatomy. If this unity of the stem, on the basis of the amphioxus, were always borne in mind, we should not have these errors constantly recurring. A wrong idea of the formation of the yelk not only led astray the most and best of the older embryologists, but the same thing not infrequently happens in our time. We have a recent instance in the excellent work, On the Embryology and Anatomy of the Ceylon Ichthyophis Glutinosus. Those admirable observers, the brothers Paul and Fritz Sarasin, formulated the thesis, in the third part of this work (18S9), that "the two germinal layers of the gastrula do not correspond to the entoderm and ectoderm, but to the blastoderm and yelk of the vertebrate," and thought they had thus " provided the foundation for a comparative embryology of the animal kingdom." On their view, " the gastrula consists of two layers, of which the inner is the lecithoblast and the outer the blastoderm." The misinterpretation oi facts and confusion of ideas which lie at the bottom of these opinions are due to the supposition that in every case the yelk is a part of the vegetal half of the embryo. As the undivided food-yelk is only a portion of the contents of the vegetal hemisphere of the ovum in the unicellular germ (the stem-cell), so we must always regard the divided food-yelk as a part of the ventral wall of the primitive gut in the multicellular embryo. The yelk embryo, or lecithoblast, of Sarasin is only a limited portion of the entoderm — that portion which developes in the ventral wall of the primitive gut from its central part; as " yelk-gland " ( lec it hade nia ) it is just as much a subordinate glandular part of the whole gut-tube as the visceral glands (liver, lungs, etc.) that afterwards grow out of it. On the other hand, the dorsal part of the embryo, which Sarasin opposes as " blastoderm " to the ventral lecithoblast, is by no means the original embryonic membrane (embracing all the entoderm and the whole of the ectoderm. In many other cases also the cenogenetic relation of the embryo to the food-yelk has until now given rise to a quite wrong idea of the first and most important embryonic processes in the higher vertebrates, and has occasioned a number of false theories in the ontogeny of them. Until thirty years ago the embryology of the higher vertebrates always started from the position that the first structure of the embryo is a flat, leafshaped disk ; it was for this reason that the cell-layers that compose this germinal disk (also called germinative area) are called " germinal layers." This flat germinal disk (blastodiscusj, which is round at first and then oval, and which is often described as the scar or cicatricula in the laid hen's egg, is found at a certain part of the surface of the large globular food-yelk. I am convinced that it is nothing else than the discoid, flattened gastrula of the birds (dtscogastrula). At the beginning of germination the flat embryonic disk curves outwards, and separates on the inner side from the underlying large yelk-ball. In this way the flat layers are converted into tubes, their edges folding and joining together (Fig. 10S). As the embryo grows at the expense of the food-yelk, the latter becomes smaller and smaller ; it is completely surrounded by the germinal layers. Later still, the remainder of the food-yelk only forms a small round sac, the yelk sac or umbilical vesicle (saccus vite/linus or vestcula umbilicalis, Fig. 108 nb). This is enclosed by the visceral layer, is connected by a thin stalk, the yelk-duct (ductus vitellinus), with the central part of the gut-tube, and is finally, in most of the vertebrates, entirely absorbed by this ( H ). The point at which this takes place, and where the gut finally closes, is the visceral navel. In the mammals, in which the remainder of the yelk-sac remains without and atrophies, the yelk-duct at length penetrates the outer ventral wall. At birth the umbilical cord proceeds from here, and the point of closure remains throughout life in the skin as the navel. embryo (or formative-yelk) and food-yelk (or yelk-sac) as original, it had also to look- upon the flat leaf-shaped structure oi the germinal disk as the primitive embryonic form, and emphasise the fact that hollow grooves were formed of these flat layers by folding, and closed tubes by the joining together oi their edges. Fig. ioS. -Severance of the discoid mammal embryo from the yelk-sac, in transverse section (diagrammatic). .1 The germinal disk (li, hf) lies flat on one side of the gill-gut vesicle (kb). />' In the middle of the germinal disk we find the medullary groove (tar), and underneath it the chorda ( ch ). C The gut-fibre-layer fdf) has been enclosed by the gut-glandlayer (ad). l> The skin-fibre-layer (hf) and gut-fibre-layer ft//') divide at the periphery ; the gu( I 1/ ) begins to separate from the yelk-sac or umbilical vesicle /■'. The medullary tube ( mr j is closed; the body-cavity (c) begins to form. /•' The provertebrae ( w) begin to grow round the medullary tube (mr) ami the chorda ( rh ) : the gut (a) is cul off from the umbilical vesiclefni/ // The vertebrae I w) have grown round the medullary tube ( mr ) and chorda ■, the body-cavity is closed, and the umbilical vesicle has disappeared. The amnion and serous membrane are omitted. The letters have the same meaning throughout : /; horn-plate, mr medullary tube, hf skin-fibre-layer, tc provertebrae, ch chorda, c body-cavity or cceloma, fibre-layer, dd gut-gland-layer, d gut-cavity, nb umbilical vesicle. This idea, which dominated the whole treatment o( the embryology oi the higher vertebrates until thirty years ago, was totally false. The gastraea theory, which has its chief application here, teaches us that it is the very reverse of the truth. The cup-shaped gastrula, in the body-wall oi which the two primary germinal lasers appear from the first as closed tubes, is the original embryonic form of all the vertebrates, and all the invertebrate metazoa ; and the flat germinal disk with its superficially expanded germinal layers is a later, secondary form, due to the cenogenetic formation of the large food-yelk and the gradual spread of the germlayers over its surface. Hence the actual folding of the germinal layers and their conversion into tubes is not an original and primary, but a much later and tertiary, evolutionary process. In the phylogeny of the vertebrate embryonic process we may distinguish the following three stages : — As this theory, a logical conclusion from the gastraea theory, has been fully substantiated by the comparative study of gastrulation in the last few decades, we must exactly reverse the hitherto prevalent mode of treatment. The yelksac is not to be treated, as was done formerly, as if it were originally antithetic to the embryo, but as an essential part of it, a part of its visceral tube. The primitive gut of the gastrula has, on this view, been divided into two parts in the higher animals as a result of the cenogenetic formation of the food-yelk — the permanent or after-gut (metagaster)^ or the permanent alimentary canal, and the yelk-sac ( lecithoma ) or umbilical vesicle. This is very clearly shown by the comparative ontogeny of the fishes and amphibia. In these cases the whole yelk undergoes cleavage at first, and forms a yelk-gland, composed of yelk-cells, in the ventral wall of sac that is cut off outside. When we make a comparative study of the embryology of the amphioxus, the frog, the chick, and the hare (Plates II., III.), there cannot, in my opinion, be any further doubt as to the truth of this position, which I have held for thirty years. Hence in the light of the gastraea theory we must regard the features of the amphioxus as the only and real primitive structure, departing very little from the palingenetic embrvonic form, among all the vertebrates. In the cyclostoma and the frog these features are, on the whole, not much altered cenogeneticallv, but very much so in the chick, and most of all in the hare. In the bell-gastrula of the amphioxus and in the crested gastrula of the petromyzoa and the frog the germinal layers are found to be closed tubes or vesicles from the first (Plate II., Figs. 6, 11). On the other hand, the chick-embrvo (in the new laid, but not yet hatched, egg) is a flat circular disk, and it was not easy to recognise this as a real gastrula. Rauber and Goette have, however, achieved this. As the discoid gastrula grows round the large globular yelk, and the after-gut or permanent gut then separates from the outlying velk-sac, we find all the processes which we have shown (diagrammatically) in Fig. 108 — processes that were hitherto regarded as principal acts, whereas they are merely secondary. The oldest, oviparous mammals, the discoblastic monotremes, behave in the same way as the sauropsida (reptiles and birds). But the corresponding embryonic processes in the viviparous mammals, the marsupials and placentals, are very elaborate and distinctive. They were formerly quite misinterpreted ; it was not until the publication of the studies of Edward van Beneden (1875) and the later research of Selenka, Kuppfer, Rabl, and others, that light was thrown on them, and we were in a position to bring them into line with the principles of the gastraea theory and trace them to the embrvonic forms of the lower vertebrates. Although there is no independent food-yelk, apart from the formative yelk, in the mammal ovum, and although their segmentation is total on that account, nevertheless a large yelk-sac ( lecithoma ) is formed in their embryos, and the " embryo proper " spreads leaf-wise over its surface, as in the reptiles and birds, which have a large foqd-yelk and partial segmentation. In the mammals, as well as in the latter, the flat, leaf-shaped germinal disk (blastodiscus ) separates from the yelk-sac, and its edges join together and form tubes. How, then, can we explain this curious anomaly? Only as a result of very characteristic and peculiar cenogenetic modifications of the embryonic process, the real causes of which must be sought in the change in the rearing of the young on the part of the viviparous mammals. These are clearly connected with the fact that the ancestors of the viviparous mammals were oviparous amniotes like the present monotremes, and only gradually became viviparous. This can no longer be questioned now that it has been shown (1884) that the monotremes, the lowest and oldest of the mammals, still lav eggs, and that these develop like the discoblastic ova of the reptiles and birds. Their nearest descendants, the marsupials, formed the habit of retaining the eggs, and developing them in the oviduct ; the latter was thus converted into a womb (uterus). A nutritive fluid that was secreted from its wall, and transuded through the wall of the blastula, now served to feed the embryo, and took the place of the food-yelk. In this way the original foodyelk of the meroblastic monotremes was gradually atrophied, and at last disappeared so completely that the partial ovumsegmentation of their descendants, the rest of the mammals, once more became total. From the discogastrula of the former was evolved the distinctive epigastrula of the latter. It is only by this phylogenetic explanation that we can understand the formation and development of the peculiar, and hitherto totally misunderstood, blastula of the mammal. This vesicular condition of the mammal embryo was discovered 200 years ago (1677) by Regner de Graaf. He found in the uterus of a hare four days after impregnation small, round, loose, transparent vesicles, with a double envelope. However, Graaf's discovery passed without recognition. It was not until 1827 that these vesicles were re-discovered by Baer, and then more closely studied in 1S4J by Bischoff in the hare (Figs. 109, no). They are found in the womb of the hare, the dog, and other small mammals, a lew days after copulation. The mature ova o\ the mammal, when they have left the ovary, are fertilised either here or in the oviduct immediately afterwards by the invading sperm-cells.1 (As to the womb and oviduct see Chapter XXIX.) The cleavage and formation of the gastrula take place in the oviduct. Either here in the oviduct or after the mammal gastrula has passed into the 1 From Bischoff. 1 uterus it is converted into the globular vesicle which is shown externally in Fig. 109, and in section in Fig. no. The thick, outer, structureless envelope that encloses it is the original ovo/emma or zona pellucida, modified, and clothed with a layer of albumin that has been deposited on the outside. From this stage the envelope is called the external membrane, the primarv chorion or prochorion < a 1. 1 In man and the other mammals the fertilisation of the ova probably takes place, as a rule, in tin' oviduct ; here the ova, which issue from the Female ovary in the shape ol the Graafian Follicle, and enter tin' inner aperture of the oviduct, encounter the mobile sperm-cells of the male seed, which pass into the uterus at copulation, and from this into the external aperture ol the oviduct. Impregnation rarely takes place in the ovary or In the womb. The real wall of the vesicle enclosed by it consists of a simple layer of ectodermic cells (bj, which are flattened by mutual pressure, and generally hexagonal ; a light nucleus shines through their fine-grained protoplasm (Fig. m). At one part (c) inside this hollow ball we find a circular disc, formed of darker, softer, and rounder cells, the dark-grained entodermic cells (Fig. 112). The characteristic embryonic form that the developing mammal now exhibits has up to the present usually been called the "blastula" (Bischoff), "sac-shaped embryo" (Baer), "vesicular embryo" (vesicula blastoderm ica, or, briefly, blastosphcvra ). The wall of the hollow vesicle, which consists of a single layer of cells, was called the "blastoderm," and logous to the embryonic vesicle of the mammal. However, this is by no means the case. What is called the " blastula " of the mammal and the real blastula of the amphioxus and many of the invertebrates are totally different embryonic structures. The latter (blastula) is palingenetic, and precedes the formation of the gastrula. The former (blastodermic vesicle) is cenogenetic, and follows gastrulation. The globular wall of the blastula is a real blastoderm, and consists of homogeneous (blastodermic) cells ; it is not yet differentiated into the two primary germinal layers. But the globular wall of the mammal vesicle is the differentiated ectoderm, and at one point in it we find a circular disk of quite different cells — the entoderm. The round cavity, filled with fluid, inside the real blastula is the segmentation-cavity. But the similar cavity within the mammal vesicle is the yelk-sac cavity, which is connected with the incipient gut-cavity. This primitive gutcavity passes directly into the segmentation-cavity in the mammals, in consequence of the peculiar cenogenetic changes in their gastrulation, which we have considered previously (cf. Chapter IX.). For these reasons it is very necessary to recognise the secondary embryonic vesicle in the mammal ( gastrocystis or blastocyst is, formerly called vesicula blastodermica) as a characteristic structure peculiar to this class, and distinguish it carefully from the primary blastula of the amphioxus and the invertebrates. The wall of this mammal vesicle consists of two different parts. The greater portion of it is onelayered, and formed only of the ectoderm. The smaller part, namely the round disk that is made up of the two primary germinal layers, may be called with Van Beneden the gastric disk ( gast rodiscus ,. The primary ectoderm is partly transitory (a temporary envelope or Raub's "covering layer"), and is replaced by a secondary ectoderm, which developes from the border of the gastric disk. The small, circular, whitish, and opaque spot which this gastric disk forms at a certain part of the surface of the clear and transparent embryonic vesicle has long been known to science, and compared to the germinal disk of the birds and reptiles. Sometimes it has been called the germinal disk (discus blastodermicus), sometimes the germinal spot (tache embryonnaire), and usually the germinative area (area germinattDa). From the area the further development of the embryo proceeds. However, the larger part of the embrvonic vesicle of the mammal is not directly used tor building up the later body, but for the construction o( the temporary umbilical vesicle. The embryo separates from this in proportion as it grows at its expense ; the two are only connected bv the yelk-duct (the stalk of the yelksac), and this maintains the direct communication between the cavity of the umbilical vesicle and the forming visceral cavity (Fig. io.S). The germinative area or gastric disk of the mammal consists at first (like the germinal disk of birds and reptiles) merely of the two primary germinal layers, the ectoderm and entoderm. But soon there appears in the middle of the circular disk between the two a third stratum of cells, the rudiment of the middle layer or fibrous layer (mesoderma). This middle germinal layer consists from the first, as we have seen in the tenth Chapter, of two separate epithelial plates, the two lavers of the ccelom-pouches (parietal and visceral). However, in all the amniotes (on account of the large formation of yelk) these thin middle plates are so firmly pressed together that they seem to represent a single layer. It is thus peculiar to the amniotes that the middle of the germinative area is composed of four germinal layers, the two limiting (or primary) layers and the middle layers between them (Figs. 99, 100). These four secondary germinal layers can be clearly distinguished as soon as what is called the sickle-groove (or "embryonic sickle") is seen at the hind border of the germinative area. At the periphery, however, the germinative area of the mammal only consists of two layers. The rest of the wall of the embryonic vesicle consists at first (but only for a short time in most of the mammals) of a single layer, the outer germinal layer. From this stage, however, the whole wall of the embryonic vesicle becomes two-layered. The middle of the germinative area is much thickened by the growth of the cells of the middle layers, and the inner layer expands at the same time, and increases at the border of the disk all round. Lying close on the outer layer throughout, it grows over its inner surface at all points, covers first the upper and then the lower hemisphere, and at last closes in the middle of the inner layer (Figs. 113-117). The wall of the embryonic vesicle now consists throughout of two layers of cells, the ectoderm without and the entoderm within. It is only in the centre of the circular area, which becomes thicker and thicker through the growth of the middle layers, that it is made up of all four layers. At the same time small structureless tufts or warts are deposited on the surface of the outer ovolemma or Fig. 113. Ovum of a hare from the iiu-ruN, tour mm. in diameter. The embryonic vesicle ( l> ) lias withdrawn ;i little from the smooth ovolemma In tlio middle ot~ the ovolemma we see the round germinal disk (blast odiscus, c), at the edge of which (at </i the inner layer of the embryonic vesicle is already beginning to expand. (Figs. 113 117 from B\ the uterus, six mm. in diameter. The blastoberm is already for the most part two-layered (b). The ovolemma, or outer envelope, is tufted (a), the germinative area and the four-layered embryonic disk. It is here alone that we find the important changes which lead to the differentiation of the first organs. In this it is immaterial whether we examine the germinative area of the mammal (of the hare, for instance) or the germinal disk of a bird or a reptile (such as a lizard or tortoise). The embryonic processes we are now going to consider are essentially the same in all members of the three higher classes of vertebrates which we call the amniotes. Man is found to agree in this respect with the hare, dog, ox, etc. ; and in all these mammals the germinative area undergoes essentially the same changes as in the birds and reptiles. They are most without. frequently and accurately studied in the chick, because we can have incubated hen's eggs in any quantity at any stage of development. Moreover, the round germinal disk of the chick passes immediately after the beginning of incubation (within a few hours) from the two-layered to the four-layered stage, the two-layered mesoderm developing from the median primitive groove between the ectoderm and entoderm (Figs. 85-98). darker nuclei in their protoplasm. This gives rise to a dark ring, more or less sharply set oi'i from the lighter centre ol the germinal disk (Fig. 1 1 S ) . From this point the latter takes the name of the "light area" (area pellucida J, and the darker ring is called the " dark area " (area Opaca). (In a Strong light, as in Figs. [18-120, the light area seems dark, because the (.lark ground is seen through it ; and the dark area seems whiter.) The circtilar shape of the area now changes into elliptic, and then immediately into oval (Figs. 1 10, 120). One end seems to be broader and blunter, the other narrower and more pointed; the former corresponds to the anterior and the latter to the posterior section of the subsequent body. At the same time, we can already trace the characteristic bilateral form of the body, the antithesis of right and left, hefore and behind. This will be made clearer by the ••primitive streak," which appears at the posterior end. At an early stage an opaque spot is seen in the middle of the clear germinative area, and this also passes from a circular to an oval shape. At first this shield-shaped marking is very delicate and barely perceptible ; but it soon becomes clearer, and now stands out as an oval shield, surrounded by two rings or areas (Fig. 120). The inner and brighter ring is the remainder of the pellucid area, and the dark outer rin^ the remainder of the opaque area ; the opaque shield-like spot itself is the first rudiment of the dorsal part of the embryo. We give it briefly the name of embryonic shield (embryaspis) or dorsal shield (notaspis). ' Remak has called it the " double shield," because it arises from a shield-shaped thickening of the outer and middle germinal layer. Inmost works this embryonic shield is described as "the first rudiment or trace of the embryo" or "primitive embryo." But this is wrong, though it rests on the authority of Baer and, Bischoff. As a matter of fact, we already have the embryo in the stem-cell, the gastrula, and all the subsequent stages. 1 Tin- germinal shield is at first merely .1 dorsal shield in the amniotes ; when tin- frontal septum is afterwards formed between the episoma and byposoma, the dorsal shield appears as the "stem-zone" in contrast to the ventral body (" parietal zone" or yelk-sac). dorsal part, which is the earliest to develop. As the older names of " embryonic rudiment " and "germinative area" are used in many different senses — and this has led to a fatal confusion in ontogenetic literature — we must explain very clearly the real significance of these important embryonic parts of the amniote. Remak had pointed out in 1850 that it is quite wrong to describe the embryonic shield or " Baer's shield " as " the future embryo " or " the first trace of the embryo." The primary germinal layers are really the first rudiment of the embryo. Nevertheless, the older names have been retained in great measure to our own time, thanks to the authority of Baer and Bischoff. Thus, Kolliker, for instance, one of the most distinguished and influential embryologists, says, even in the latest edition of his Human Embryology (1884) : " In the middle of the pellucid area (of the chick) we get later on the first traces of the embryo"; and in the blastodermic vesicle o( the hare ■• there appears, at the part where it is three-layered, a white, round, opaque spot, the embryonal spot (urea embryonalis), which is no other than the first outline o( the embryo." The misunderstanding that arises from these and similar expressions has led to a number of serious errors in explaining the embryonic structures. In view of these, I must formally draw up the following principles : — 1. The so-called "first trace of the embryo" hi the amniotes, or the embryonic shield ( embiyaspis ) , in the centre of the pellucid area, consists merely of an early differentiation and formation of the middle dorsal parts. 3. The i^erminative area, in which the first embryonal blood-vessels appear at an early Stage, is not opposed as an external area to the "embryo proper," but is a part of it. 4. In the same way, the yelk-sac or the umbilical vesicle (the " relic of the blastula ") is not a foreign external appendage o( the embryo, but an outlying part of its primitive gut, an embryonal visceral gland. 5. The dorsal shield gradually separates from the i^erminative area and the yelk-sac, its edges growing downwards and folding together to form ventral plates (lamina ventrales). (>. The yelk-sac and vessels of the germinative area, which soon spread over its whole surface, are, therefore, real embryonal organs, or temporary parts of the embryo, and have a transitory importance in connection with the nutrition of the growing later body ; the latter may be called the " permanent body " (menosoma) in contrast to them. The relation of these cenogenetic features of the amniotes to the palinijenetic structures of the older non-amniotic vertebrates may be expressed in the following theses: The original gastrula, which completely passes into the embryonic bodv in the acrania, cyclostoma, and amphibia, is early divided into two parts in the amniotes — the embryonic shield (embtyaspis), which represents the dorsal outline of the permanent body (menosoma); and the temporary embryonic organs of the germinative area and its bloodvessels, which soon grow over the whole of the yelk-sac. The differences which we find in the various classes of the vertebrate stem in these important particulars can only be fully understood when we bear in mind their phylogenetic relations on the one hand, and, on the other, the cenogenetic modifications of structure that have been brought about by changes in the rearing of the young and the variation in the mass of the food-yelk. We have already described in the ninth Chapter the changes which this polyphyletic increase and decrease of the nutritive yelk causes in the form of the gastrula, and especially in the situation and shape of the primitive mouth. The primitive mouth or prostoma is originally a simple round aperture at the lower (aboral) pole of the long axis ; its dorsal lip is above and ventral lip below. In the holoblastic amphioxus this primitive mouth is a little eccentric, or shifted to the dorsal side (Fig. 41). The aperture increases with the growth of the food-yelk in the cyclostoma and ganoids ; in the sturgeon it lies almost on the equator of the round ovum, the ventral lip (a) in front and the dorsal lip (b) behind (Fig. 122 b). In the wide-mouthed, circular discoid gastrula of the selachii or primitive fishes, which spreads quite flat on the large food-yelk, the anterior semi-circle of the border of the disk is the ventral, and the posterior semicircle the dorsal lip (Fig. 122 A). The formation of a large food-yelk followed again in the stem-forms of the amniotes, the protaminotes or proreptilia, descended from the amphibia (Fig. 122 D). But here the accumulation of the food-yelk took place only in the ventral wall of the primitive-gut, so that the narrow primitive mouth Lying behind was forced upwards, and came to lie on the back of the discoid " epigastrula " in the shape of the "primitive groove"; thus (in contrast to the case of the selachii, Fig. 122 J) the dorsal lip (b) had to be in front, and the ventral \\p(i/J behind (Fig. 122 D). This feature was transmitted to all the amniotes, whether they retained the large food-yelk (reptiles, birds, and monotremes), or lost it by atrophy (the viviparous mammals). Fig. 122. -Median longitudinal section of the gastrula of four vertebrates. (From RabT.) .1 discogastrula of a shark (pristiurus). 11 amphigastrula of a sturgeon ( accipenser ). C amphigastrula of an ampbibium (tritniij. D epigastrula of an amniote (diagram), a ventral, b dorsal lip o\ the primitive mouth. This phvlogenetic explanation oi gastrulation and ccelomation and the comparative Study oi them in the various vertebrates throw a clear and full light on many ontogenetic phenomena, as to which the most obscure and confused opinions were prevalent thirty years ago. In this we see especially the high scientific value o<i the biogenetic law and the careful separation of palingenetic from cenogenetic processes. To the opponents of this law the real explanation of these remarkable phenomena is impossible. We have curious instances of this lack of a thorough grasp of the subject in Wilhelm His (of Leipzig) and Victor Hensen (of Kiel). Although these industrious observers have been devoted to the accurate description of ontogenetic facts for more than thirty years, they have completely failed to detect their phylogenetic causes. The same may be said of many new workers in the field of mechanical and experimental embryology. Of these Hans Driesch particularly deserves notice for the obscurity of his ideas and lack of a real grip of the biogenetic processes. In his violent antagonism to the theory of descent he goes as far as to say that all Darwinists have softening of the brain, and that Darwinism is only the illusion of a generation. Driesch has lately won a certain regard in uneducated circles by foolish expressions of this kind, and by his metaphysical speculations on neo-vitalism. This, however, is chiefly grounded on the fact that no one can find any rational meaning in his extraordinary theories. Both these vitalistic vagaries and the supposed simple mechanical explanations that " mechanical evolutionists " give of historical processes are totally unsatisfactory (see p. 46). Here, and in every other part of embryology, the true key to the solution lies in phylogeny. DORSAL BODY AND VENTRAL BODY Development of the dorsal shield ( nofaspis). Primitive groove (primitive mouth) in the hind half and medullary groove in the fore-half of the dorsal shield. Connection of the two median grooves by the medullary visceral duet or neurenteric canal. Neuroporus. The oval form of the embryonic disk changes into a sandal-shape. Differentiation of dorsal body (episoma or stem-zone)and ventral body (hyposoma or parietal zone). Separation of the two by the lateral furrow. Differentiation of prevertebral plates and lateral plates. Transverse studies of the sole-shaped amniote embryo. Separation of the medullary tube from the horn-plate. Origin of the closed gastric tube from the flat gut-layer of the embryonic shield. Formation of the navel. Separation of the mammal embryonic shield from the embryonic vesicle. Cutaneous navel and intestinal navel. Formation of the amnion, the allantois, and the umbilical vesicle. Similar construction of dorsal wall and ventral wall. Fore gut-cavity and pelvic-cavity. Mouth-pit and anus-pit. Pro-renal ducts. First blood-vessels. The earliest stages of the human embryo are, for the reasons already given, either quite unknown or only imperfectly known to us. But as the subsequent embryonic forms in man behave and develop just as they do in all the other mammals, there cannot be the slightest doubt that the preceding stages also are similar. We have been able to see in the ccelomula of the human embryo (Fig. ioo), by transverse sections through its primitive mouth, that its two ccelom-pouches are developed in just the same way as in the hare (Fig. 99); moreover, the peculiar course of the gastrulation is just the same. The germinative area forms in the human embryo in the same way as in the other mammals, and in the axial middle part of this we have the embryonic^shield (embryaspisj, the purport of which we considered in the preceding chapter. The next changes of the embryonic disk, or the "embryonic spot" (area embrvonalis ), take place in corresponding fashion. These are the changes we are now going to consider more closely. narrow hinder end ; it is in the median line o\ this that the primitive streak appears (Fig. 124 ps). The narrow longitudinal groove or meridian furrow in it — the so-called •• primitive groove" — is, as we have seen, t he primitive mouth Fig. 1 23. -Embryonic vesicle of a seven-days' old hare with oval embryonic shield (ag)- -< seen from above, B from the side. (From Kolliker.) ay dorsal shield (notaspis)or embryonic spot ( un-u embryonalis). In li the upper half of the vesicle is made up of the two primary germinal layers, the lower (up to e») only from the outer layer. Fig. 124. Oval embryonic shield of the hare (Fig. 124 •' i>\|' six days eighteen hour-, il of eight days). (From KSUiker.) ps primitive streak, />/• primitive groove, arg area germinalis, sw sickle-shaped terminal growth. o( the gastrula. In the gastrula-embryos of the mammals, which are much modified cenogenetically, this cleft-shaped prostoma is lengthened so much that it soon traverses the whole o\ the hinder hall" of the dorsal shield ; as we find in a hare-embryo of six to eight days (Fig. 125 pr). The two swollen parallel borders that limit this median furrow are the lateral lips of the primitive mouth, right and left. In this way the bilateral, dipleurous, or bilateral-symmetrical type of the vertebrate becomes pronounced. The subsequent head of the amniote is developed from the broader and rounder fore-half of the dorsal shield. the primitive mouth, however, lie, as we know, at the important point where the outer layer bends over the inner, and from which the two coelom pouches grow between the primary germinal layers. Thus the median primitive furrow (pr) in the hind-half and the median medullary furrow ( rf) in the fore-half of the oval shield are totally different structures, although the latter seems to a superficial observer to be merely the forward continuation of the former. Hence they were formerly always contused, and in the oldest and much-copied illustration of the dorsal shield of the hare which Bischoff gave in [842 (Fig. 120) one simple longitudinal furrow goes the whole length of the middle line. This error was the more pardonable as immediately afterwards the two grooves do actually connect in a very remarkable way. The two parallel dorsal swellings, which pass into each other arch-wise in front, diverge in the rear and embrace the anterior end of the primitive groove (Fig. 125). They then grow together over it in such a way that the primitive groove (or the hindermost cavity of the primitive gut) passes directly into the closing medullary tube. The point of transition is the remarkable neurenteric canal (Fig. 127 en). The thickened mass at the border of the primitive mouth, which surrounds it, is the neurenteric knot (or "Hensen's knot." Fig. 126 nk). The direct connection which is thus established between the two cavities of the primitive gut and the medullary tube does not last long; the two are soon definitely separated by a partition. The enigmatic canalis neurentericus is a very old embryonic organ, and of great phylogenetic interest, because it arises in the same way in all the chordoma (both tunieates and vertebrates). In every case it touches or embraces like an arch the posterior end of the chorda, which has been developed here in front out of the middle line of the primitive gut (between the two coelom-folds of the sickle-groove) ("head-process," Fig. 126 kf). These very ancient and strictly hereditary structures, which have no physiological significance to-day, deserve (as "rudimentary organs ") our closest attention. The tenacity with which the useless neurenteric canal has been transmitted down to man through the whole series of vertebrates is of equal interest for the theory of descent in general, and the phylogeny of the chordonia in particular. The connection which the canalis neurentericus (Fig. 127 en) establishes between the dorsal nerve-tube (11) and the ventral gut-tube ( d ) is seen very plainly in the amphioxus in a longitudinal section of the ccelomula, as soon as the primitive mouth is completely closed at its hinder end. The medullary tube has still at this stage an opening at the forward end, the neuroporus (Fig. 86 np). This opening also is afterwards closed. There are then two completely closed canals over each other — the medullary tube above and the gastric tube below, the two being separated by the chorda. The same features as in the acrania are exhibited by the related tunicates, the ascidia (Plate XVIII., Figs. 5, 6). Again, we find the neurenteric canal in just the same form and situation in the amphibia. A longitudinal section of a young tadpole (Fig. i 2S) shows how we may penetrate from the still open primitive mouth (x) either into the wide primitive gut-cavity ( al ) or the narrow overlying nerve-tube. A little later, when the primitive mouth is closed, the narrow neurenteric canal (Fig. i2(), ne) represents the arched connection between the dorsal medullary canal ( ' mc ) and the ventral gastric canal. The medullary furrow (me), which is not \vt visible in Ki_<. 130, encloses with it> hinder end the fore >-nil of the primitive groove (pr) in Fig. 131. primitive mouth travels completely over to the dorsal surface of the gastrula, and is converted into the longitudinal furrow we call the primitive groove. Hence the primitive groove (I'ig. 131 pr), examined from above, appears to be the straight continuation of the fore-lying and younger medullary furrow (me). The divergent hind legs of the latter embrace the anterior end of the former. Afterwards we have the complete closing of the primitive mouth, the dorsal swellings joining to form the medullary tube and growing over the prostoma. The canalis neurentericus then Balfour.) sp medullar}- tube, connected with the terminal gut (pag) by the neurenteric canal ( ne ), ch chorda, pr neurenteric (or Hensen's) knot, al allantois, ep ectoderm, hy entoderm, so parietal laj-er, sp visceral layer, «« amispit, am amnion. While these important processes are taking place in the axial part of the dorsal shield, its external form also is changing. The oval form (Fig. 120) becomes like the sole Fig. 133.— Germinal area or germinal disk of the hare with soleshaped embryonic shield, magnified about ten times. The clear circular field (d) is the opaque area. The pellucid area (c) is lyre-shaped, like the embryonic shield itself ( b). In its axis is seen the dorsal furrow or medullary furrow (a). ( From Bisrhoff. ) The characteristic sandal-shape of the dorsal shield, which is determined by the narrowness of the middle part, and which is compared to a violin, lyre, or shoe sole, persists for a long time in all the amniotes. All mammals, birds, and reptiles have substantially the same construction at this in the sandal-form it is even Fig. 137. — Sandal-shaped embryonie shield of a hare of nine more pronounced (Figs. 134- more clearly differentiated in the sole-shaped embryonic shield, and so are the lateral organs that develop symmetrically to the right and left of them. In these lateral organs of the embryonic shield a darker central and a lighter peripheral zone become more obvious ; the former is called the stem-zone (Fig. 137 stz), The stem-zone o( the amniote embryo would be called more appropriately the dorsal zone or dorsal shield ; from it developes the whole of the dorsal half o( the later body (or permanent body) — that is to say, the dorsal body (episoma). Again, it would be better to call the "parietal zone" the ventral zone or ventral shield ; from it develop the ventral "lateral plates," which afterwards separate from the embryonic vesicle and form the ventral body (hypotonia ) — that is to say, the ventral half of the permanent body, together with the body-cavity and the gastric canal that it encloses. The sole-shaped germinal shields of all the amniotes are still, at the Stage of construction which Fig. [37 illustrates in the hare and Fig. i,yS in the opossum, so like each other that we can either not distinguish them at all or only by means of quite subordinate peculiarities in the size of the various parts. Moreover, the human sandal-shaped embryo cannot at this stage be distinguished from those of other mammals, and it particularly resembles that of the hare. I have given on Plates IV. and V. the sandal-shaped embryos of six different amniotes for the purpose of comparison, and have reduced them to the same size ; all of them are highly magnified. Plate IV. shows the sandal-shaped embryonic shield (at three stages of development) of three of the sauropsids : E lizard (lacerta), C tortoise (chelonia), II hen (gallus). Plate V. gives the embryos of three mammals: 5" pig (sits). A' hare (lepus), M man (homo). On the other hand, the outer form of these Hat sandal-shaped embryos is very different from the corresponding form oi the holoblastic lower animals, especially the acrania (amphioxus). Nevertheless, the body is just the same in the essential features of its structure as that we find in the chordula ol' the latter (Figs. NO -89), and in the segmented embryonic forms which immediately develop from it. The striking external difference is here again due to the fact that in the palingenetic embryos o( the amphioxus (Figs! 80, 87) and the amphibia (Figs. 88. 89) the gut-wall and body-wall form closed tubes from the first, whereas in the cenogenetic embryos of the amniotes they are forced to expand leaf-wise on the surface owing: to the great extension of the food-velk. phys), throe days old. (From Selenia.) (Back view from above.) s/c stemzone or dorsal shield (with eight pairs of primitive segments), ps parietal or ventral zone, ap pellucid area, no opaque area, /;/; halves of the heart, v loreend, // hind-end. In the median line we see the chorda (ch) through the transparent medullary tube (m). 11 primitive segment, pr primitive streak (or primitive mouth). It is all the more notable that the early separation of dorsal and ventral halves takes place in the same rigidly hereditary fashion in all the vertebrates. In both the acrania and the craniota the dorsal body is about this period separated division has already taken place by the construction of the axial chorda between the dorsal nerve-tube and the ventral canal. But in the outer or lateral part of the body it is only brought about by the division o( the coelom-pouches into two sections by a frontal constriction — a dorsal episomite (dorsal segment or provertebra) and a ventral hyposomite (or ventral segment). In the amphioxus each of the former makes a muscular pouch, and each of the latter a sex-pouch or gonad. (Cf. the transverse section of the vertebrate. Figs. 104, 105, and Figs. 3-7 on Plate VI.) These important processes of differentiation in the mesoderm, which we will consider more closely in the next Chapter, proceed step by step with interesting changes in the ectoderm, while the entoderm changes little at first. We can study these processes best in transverse sections, made vertically to the surface through the soleshaped embryonic shield. Such a transverse section of a chick-embryo, at the end of the first day of incubation, shows the gut-gland layer as a very simple epithelium, which is spread like a leaf over the outer surface of the food-yelk (Fig. 139 tltl). The chorda (ch) has separated from the dorsal middle line of the entoderm ; to the right and left of it are the two halves of the mesoderm, or the two ccelom-folds. A narrow cleft in the latter indicates the body-cavity ( inch ) ; this separates the two plates of the ccelom-pouches, the lower (visceral) and upper (parietal). The broad dorsal furrow (Rf) formed by the medullary plate (in) is still wide open, but is divided from the lateral horn-plate ( It ) by the parallel medul la r v swell i n gs. As the medullary swellings rise and bend towards each other (Fig. 140 in), one of these parallel longitudinal furrows, the lateral furrow (sulcus lateralis), is formed in the mesoderm on each side. In this lateral furrow we find at first the prorenal duct (Fig. 141 ung). As the lateral furrow cuts completed through the middle layer, this falls into two sections : the inner or middle part ( 11 ) is the primitive segment piece, which forms the greater part of the Stem-zone, and afterwards divides by articulation into the chain of somites (in Figs. 137 and 1 38 with eight pairs of somites already). The outer or lateral section is the lateral plate (Fig. 140 sp) ; when we look at it from above it appears as the parietal zone, and afterwardsjdivides into the two fibrous layers. In the fore half of the embryonic shield, which corresponds to the later layer. head, there is no separation between the inner provertebral mass and the outer lateral plates. The median innermost part of the lateral plates, which touches the primitive segment piece or provertebral plate, is called the middle plate (Fig. 141, nip). Underneath it we find the first two blood-vessels, the primitive aortas ( ' ao ). During these processes important changes are taking place in the outer germinal layer (the "skin-sense layer"). The continued rise and growth of the dorsal swellings causes tlie end of the first day of incubation, a little more advanced than Fig. 139, magnified about twenty times. The edges of the medullary plate (m). the medullary swellings (w), which separate the medullary from the horn-plate ( h ). are bending towards each other. At each side of the chorda (ch) the primitive segment plates (u) have separated from the lateral plates (sp). A gut-gland layer. (From Remak.) their higher parts to bend together at their free borders, approach nearer and nearer (Fig. 140 w), and finally unite. Thus in the end we get from the open dorsal furrow, the upper cleft of which becomes narrower and narrower, a closed cylindrical tube (Fig. 141 nir). This tube is of the utmost importance ; it is the first rudiment of the central nervous system, the brain and spinal marrow, the medullary tube (tubus mednllaris ). This ontogenetic fact was formerly looked upon as very mysterious. We shall sec presently thai in the light o( the theory o\ descent it is a thoroughly natural process. The phylogenetic explanation oi~ it is that the central nervous system is the organ by means of which all intercourse with the outer world, all psychic action and sense-perception, are accomplished ; hence it was bound to develop originally from the outer and upper surface of the body, or from the epidermis. The medullary tube afterwards separates completely from the outer germinal layer, and is surrounded by the middle parts of the provertebrae and forced inwards (Fig. 151). The remaining portion of the skin-sense layer (Fig. 141 //) is now called the horn-plate or Fig. 141. -Transverse section of the embryonic shield (of a chick, on the second day o( incubation), magnified about one hundred times. (From KoUiier.) h horn-plate, mr medullary tube, ung prerenal duct, «;.• primitive segments, ///>/ skin-fibre layer, «//> middle plate, df gut-fibre layer, sp coelomfolds, no primitive aorta, dd gut-gland layer. horn-layer, because from it is developed the whole of the outer skin or epidermis, with all its horny appendages (nails, hair, etc.). (Cf. Plates VI. and VII. and the explanation.) A totally different organ, the prorenal (primitive kidney) duct ( ung J, is found to be developed at an early stage from the ectoderm. This is originally a quite simple, tube-shaped, lengthy duct, or straight canal, which runs from front to rear at each side of the provertebrae (on the outer side, Fig. 141, ung). It originates, it seems, out o( the horn-plate at the side oi the medullary tube, in the gap that we find between the prevertebral and the lateral plates. The prorenal duct is visible in this gap even at the time of the severance o\ the medullary lube from the horn-plate. Other observers think that the first trace oi it does not come from the skin-sense layer, but the skin-fibre layer. The inner germinal layer, or the gut-fibre layer (Fig. 141 dd), remains unchanged during these processes. A little later, however, it shows a quite flat, groove-like depression in the middle line of the embryonic shield, directly under the chorda. This depression is called the gastric groove or furrow. This at once indicates the future lot of this germinal layer. As this ventral groove gradually deepens, and its lower edges bend towards each other, it is formed into a closed tube, the alimentary canal, in the same way as the medullary groove grows into the medullary tube. The gutfibre layer (Fig. 142 /), which lies on the gut-gland layer (d), naturally follows it in its folding. Moreover, the incipient gut-wall consists from the first of two layers, internally the gut-gland layer and externally the gut-fibre layer. The formation of the alimentary canal resembles that of the medullary tube to this extent — in both cases a straight groove or furrow arises first of all in the middle line of a flat layer. The edges of this furrow then bend towards each other, and join to form a tube (Fig. 142). But the two processes are really very different. The medullary tube closes in its whole length, and forms a cylindrical tube, whereas the alimentary canal remains open in the middle, and its cavity continues for a long time in connection with the cavity of the embryonic vesicle. The open connection between the two cavities is only closed at a very late stage, the construction of the navel. The closing of the medullary tube is effected from both sides, the edges of the groove joining together from right and left. But the closing of the alimentary canal is not only effected from right and left, but also from front and rear, the edges of the ventral groove growing together from every side towards the navel. Throughout the three higher classes of vertebrates the whole of this process of the secondary construction of the gut is closely connected with the formation of the navel, or with the separation of the embryo from the yelk-sac or umbilical vesicle. (Cf. Fig. 108, and Plate VII., Figs. 14, 15.) comparison of the five stages which are shown in longitudinal section in Pigs. 143-147. The embryonic shield fc), which at first projects very slightly over the surface o( the germinative area, soon begins to rise higher above it, and to separate from the embryonic vesicle. At this point the embryonic shield, looked at from the dorsal surface, shows still the original simple sandal-shape (Figs. 135-138). We do not yet see any trace oi articulation into head, neck, trunk, etc., or limbs. But the embryonic shield has increased greatly in Fig. 14-— Three diagrammatic transverse sections of the embryonic disk of the higher vertebrate, to show the origin of the tubular organs from the bending germinal layers. In Fig. A the medullary tube (n J and the alimentary canal ( a J are still open grooves. In Fig. B the medullary tube (n) and the dorsal wall are closed, but the alimentary canal (a) and the ventral wall are closed ; the prerenal duets ( it ) mc cut oil' from the horn-plate ( h ) and internally connected with segmental prerenal canals. Iii Fig. C both the medullary tube and the dorsal wall above and the alimentary canal and ventral wall below are elosed. All the open grooves have become closed tubes ; the primitive kidneys are directed inwards. (Cf. Plates VI. and VII.) thickness, especially in the anterior part. It now has the appearance of a thick, oval swelling, strongly curved over the surface of the germinative area. It begins to sever completely from the embryonic vesicle, with which it is connected at the ventral surface. As this severance proceeds, the back bends more and more; in proportion as the embryo grows the embryonic vesicle decreases, and at last it merely hangs as a small vesicle from the belly of the embryo (Fig. 147 <A I. In consequence of the growth-movements which cause this longitudinal section passes through the sagittal or middle plane of the body, dividing the right and left halves; in Fig. 147 the embryo is seen from the left side. In Fig. 143 the tufted prochorion ( 1I1/' ) encloses the germinal vesicle, the wall of which consists of the two primary layers. Between the outer (a) and inner (i) layer the middle layer (tn) has been developed in the region of the gorminative area. In Fig. 144 the embryo (e) begins to separate from the embryonic vesicle ( 'ds ), while the wall of the amnion-fold rises about it (in front as head-sheath, is, behind as tail-sheath, ss). In Fig-, 145 the edges of the amniotic fold (am) rise together over the back of the embryo, and form the amniotic cavity ( ah) ; as the embryo separates more completely from the embryonic vesicle (ds) the alimentary canal (dd) is formed, from the hinder end of which the allantois grows (al). In Fig. 146 the allantois is larger ; the of the vesicle, the limiting furrow, which surrounds the vesicle in the shape of a pit, and a circular mound or dam (Fig. 144 ks) is formed at the outside of this pit by the elevation of the contiguous parts of the germinal vesicle. In order to understand clearly this important process, we may compare the embryo to a fortress with its surrounding rampart and trench. The ditch consists of the outer part of the germinative area, and comes to an end at the point where the area passes into the vesicle. The important fold of the middle germinal layer that brings about the formation of the body-cavity proceeds peripherally beyond the borders of the embryo over the whole germinative area. At first this middle layer reaches as far as the germinative area ; the whole of the rest of the embryonic vesicle consists in the beginning only of the two original limiting layers, the outer and inner germinal layers. Hence, as far as the germinative area extends the germinal layer splits into the two plates we have already recognised in it, the outer skin-fibre layer and the inner gutfibre layer. These two plates diverge considerably, a clear fluid gathering between them (Fig. 145 am). The inner plate, the gut-fibre layer, remains on the inner layer oi~ the embryonic vesicle (on the gut-gland layer). The outer plate, the skin-fibre layer, lies close on the outer layer o( the germinative area, or the skin-sense layer, and separates together with this from the embryonic vesicle. From these two united outer plates is formed a continuous membrane. This is the circular mound that rises higher and higher round the whole embryo, and at last joins above it (Figs. 144147 am). To return to our illustration o( the fortress, we yrelk-sac ( ds ) smaller. In Fig. 1 47 1 In- embryo shows the gill-clefts and the outline of tlu' two legs; the chorion has formed branching villi Hurts). In all lour figures ' embryo, " outer germinal layer, m middle germinal layer, 1 inner germinal layer, am amnion lis head-sheath, ss tail-sheath), ah amniotic cavity, as amniotic sheath of the umbilical cord, kh embryonic vesicle, ds yolksac (umbilical vesicle), o^p vitelline duct, <// gut-fibre layer, dd gut-gland layer, al allantois, :■/ -hh place o( heart, <l vitelline membrane (ovolemma or prochoriom, </• tufts or villi <\\ same, sh serous membrane (serolemma), s tufts oi same, ch chorion, ch* tufts or villi, si terminal vein, r pericoelom or serocoelom (tin- space, tilled with fluid, between the amnion ami chorion). ( From KSUiker. 1 (Cf. Plate VII., Figs, 14 and 15.) must imagine the circular rampart to be extraordinarily high and towering far above the fortress. Its edges bend over like the combs of an overhanging wall of rock that would enclose the fortress ; they form a deep hollow, and at last join together above. In the end the fortress lies entirely within the hollow that has been formed by the growth of the edges of this large rampart. (Cf. Figs. 148-152 and Plate VII., Fig. 14.) As the two outer layers of the germinative area thus rise in a fold about the embryo, and join above it, they come at last to form a spacious sac-like membrane about it. This envelope takes the name of the germinative membrane, or water-membrane, or amnion (Fig. 147 am). The embryo floats in a watery fluid, which fills the space between the embryo and the amnion, and is called the amniotic fluid (Figs. 146, 147 ah). We will deal with the significance of this remarkable formation later on (Chapter XV.). For the moment it does not interest us, as it has no direct relation to the construction of the body. Among the various appendages which we shall have to discuss later we will only mention, in passing, the allantois and the yelk-sac. The allantois, or the urinary sac (Figs. 145, 146 a/), is a pear-shaped vesicle that grows from the hindermost part of the alimentary canal ; its outermost section forms, with its vessels, the foundation of the placenta. In front of the allantois the yelk-sac or umbilical vesicle (ds), the remainder of the original embryonic vesicle, starts from the open belly of the embryo (Fig. 143 kh). In more advanced embryos, in which the gastric wall and the ventral wall are nearly closed, it hangs out of the navel-opening in the shape of a small vesicle with a stalk (Figs. 146, 147, ds). Its wall consists of two layers, the gut-gland layer within and the gut-fibre layer without. Hence it is a vesicular appendage of the alimentary canal proper, an embryonic "gastric gland." The more the embryo grows, the smaller becomes the vitelline (yelk) sac or lecithoma. At first the embryo looks like a small appendage of the large embryonic vesicle. Afterwards it is the yolk-sac, or the remainder of the embryonic vesicle, that seems a small pouch-like appendage o( the embryo (Fig. 147 ds). It ceases to have any significance in the end. The very wide opening, through which the gastric cavity at first communicates with the umbilical vesicle, becomes narrower and narrower, and at last disappears altogether. The nave/, the small pit-like depression that we find in the developed man in the middle of the abdominal wall, is the spot at which the remainder of the embryonic vesicle (the umbilical vesicle) originally entered into the ventral cavity, and joined on to the growing gut. (Cf. Figs. 14 and 15 on Plate \TI.) The origin of the navel coincides with the complete closing o( the external ventral wall. In the amniotes the ventral wall originates in the same way as the dorsal wall. Both are formed substantially' from the skin-fibre layer, and externally covered with the horn-plate, the peripheral section of the skin-sense layer. Both come into existence by the conversion of the four flat germinal lavers of the embryonic shield into a double tube by folding from opposite directions ; above, at the back, we have the vertebral canal which encloses the medullary tube, and below, at the belly, the wall of the body-cavity which contains the alimentary- canal (Fig. .42). We will consider the formation of the dorsal wall first and that of the ventral wall afterwards (Figs. 14N-152). In the middle of the dorsal surface of the embryo there is originally-, as we already know, the medullary f»irj tube directly underneath the horn-plate (h) from the middle part of which it has been developed. Later, however, the prevertebral plates ( uw ) grow over from the right and left between these originally connected parts (Figs. 150, 151). The upper and inner edges of the two prove rtebral plates push between the hornplate and medullary tube, force them away from each other, and finally join between them in a seam that corresponds to the middle line of the back. The coalescence of these two dorsal plates and the closing in the middle of the dorsal wall take place in the same way as the medullary tube, which is henceforth enclosed by the vertebral tube. Thus is formed the dorsal wall, and the medullary tube takes up a position inside the body. In the same way the provertebral mass grows afterwards round the chorda, and forms the vertebral column. Below this the inner and outer edge of the provertebral plate splits on each side into two horizontal plates, of which the upper pushes between ihe chorda and medullary tube, and the lower between the chorda and srastric tube. As of the second, Fig'. 149 of the third, Fig. 150 of the fourth, and Fig. 151 of the fifth day of incubation. Pig's. 14S-150 from Kolliker, magnified about [00 times ; Fig. 151 from Remak, magnified about twenty times, h horn-plate, mr medullary tube, uiig- prerenal duct, un prerenal vesicles, hf> skin-fibre layer, m = mu — mp muscle-plate, itiv provertebral plate [wh cutaneous rudiment of the body of the vertebra, ivb of the arch of the vertebra, ivq the rib or transverse continuation), uwh provertebral cavity, ch axial rod or chord, sh chorda-sheath, bh ventral wall, g hind and v fore root of the spinal nerves, a=af=am amniotic fold, p body-cavity or cceloma, c(/"gut-fibre layer, ao primitive aortas, sa secondary aorta, vr cardinal veins, d=dd gut-gland layer, dr gastric groove. In Fig. 14S the larger part of the right half, in Fig. 149 the larger part of the left half, of the section is emitted. Of the velk-sac or remainder of the embrvonic vesicle only a small piece of the wall is indicated below. (Cf. the sections in Plate VI., Figs. 3-S.) Fig. rS the plates meet from both sides above and below the chorda, they completely enclose it, and so form the tubular, outer chord-sheath, the skeleton-forming sheath from which the We find below in the construction of the ventral wall precisely the same processes as in the formation of the dorsal wall (Fig. 142 b, Fig. 149 hp, Fig. 151 bh). It is formed on the flat embryonic shield of the amniotes from the upper plates of the parietal zone, or the parietal lamella of the lateral plates, which is covered with the horn-plate. The right and left parietal plates bend downwards towards each other, and grow round the gut in the same way as the gut itself closes. The outer part of the lateral plates forms the ventral wall or the lower wall of the body, the two lateral plates bending considerably on the inner side of the amniotic fold, and growing towards each other from right and left. While the alimentary canal is closing, the body-wall also closes on all sides. Hence the ventral wall, which embraces the whole ventral cavity below, consists of two parts, two lateral plates that bend towards each other. These approach each other all along, and at last meet at the navel. We ought, therefore, really to distinguish two navels, an inner and an outer one. The internal or intestinal navel is the definitive point of the closing of the alimentary wall, wrhich puts an end to the open communication between the ventral cavity and the cavity of the yelk-sac (Fig. 108). The external or cutaneous navel is the definitive point of the closing of the ventral wall ; this is visible in the developed body as a small depression. In each case two secondary germinal layers take part in the coalescence — in the gut-wall the gut-gland layer and gut-fibre layer ; in the ventral wall the skin-fibre layer and skin-sense layer. With the formation of the internal navel and the closing of the alimentary canal is connected the formation of two cavities which we call the capital and the pelvic sections of the visceral cavity. As the embryonic shield lies flat on the wall of the embryonic vesicle at first, and only gradually separates from it, its fore and hind ends are independent in the beginning ; on the other hand, the middle part of the ventral surface is connected with the yolk-sac by means o( tin.- vitelline or umbilical duet (Fig. 152 m). This leads to a notable curving of the dorsal surface ; the head-end bends downwards towards the breast and the tail-end towards the belly. We see this very clearly in the excellent old diagrammatic illustration given by Baer (Fig. [52), a median longitudinal section of the embryo of the chick in which the dorsal body or episoma is deeply shaded. The embryo seems to be trying to roll up, like a hedgehog protecting itself from its pursuers. This pronounced curve of the back Fig. 152. -Median longitudinal section of the embryo of a chick (fifth day of incubation), seen from the right side (head to the right, tail to the left). Dorsal body (episoma) dark, with convex outline, <l gut, o mouth, a amis. / lungs, // liver, g mesentery, v auricle of the heart, k ventricle of thi h arch of the arteries, /aorta, c yelk-sac, m vitelline (yelk) duct, u allantois, r pedicle (-.talk) of the allantois, n amnion, 70 amniotic cavity (amniocoel), is due to the more rapid growth of the convex dorsal surface, and is directly connected with the severance of the embryo from the yelk-sac. At the head there is no division of skinfibre layer from gut-fibre layer, as there is in the trunk, but the two remain joined, and are called the " head-plates." As these head-plates release themselves at an early stage from the surface of the germinative area, and grow, first downwards towards the surface of the embryonic vesicle and then backwards towards its passage into the alimentary groove, a small ca\ity is formed within the head-part this represents the foremost and blindly closed part of the gut. It is the small "head-cavity of the gut" (Fig. 153, above d) ; its opening in the middle gut is called the " fore entrance of the gut" (Fig. 153 at d). It corresponds to the branchial gut of the amphioxus, which nearly occupies the fore half of the body. The tail-end bends for- at the end of the first day of incubation (seen from the left side). k head-plates, ch chorda. Above it cavity of the guti d gut-gland layer, df gut-fibre layer, // horn-plate, hh cavity of the heart, ££ heart-capsule, The embryo now, as it were, presses into the outer surface of the embryonic vesicle with its free ends, while it moves away from it with its middle part. As a result of this change the yelk-sac becomes henceforth only a pouch-like outer appendage at the middle of the ventral wall. The ventral appendage, growing smaller and smaller, is afterwards ealled the umbilical (navel) vesicle. (Cf. Figs. 146, 147 us; Fig. 151 and Plate VII., Figs. 14, 15.) The cavity of the yelk-sac or umbilical vesicle communicates with the corresponding visceral cavity by a wide opening, which gradually contracts into a narrow and long canal, the vitelline (yelk) duct (ductus vitellinus, Fig. 152 in). Hence, if we were to imagine ourselves in the cavity of the yelk-sac, we could get from it through the yelk-duct into the middle and still wide open part of the alimentary canal. If we were to go forward from there into the head-part of the embryo, we should reach the capital cavity of the gut, the fore-end of which is closed up. Hence the first structure of the alimentary canal consists now of three different sections: (1) The capital cavity, which opens behind (through the fore-opening of the gut) into the middle gut; (2) the middle cavity, which opens below (through the vitelline duct) into the yelk-sac ; and (3) the pelvic cavity, which opens outwards (by the hind aperture of the gut) into the middle gut. The reader will ask : " Where are the mouth and the anus? " These are not at first present in the embryo. The whole of the primitive gut-cavity is completely closed, and is merely connected in the middle by the vitelline duct with the equally closed cavity of the embryonic vesicle (Fig. 145). The two later apertures of the alimentary canal — the anus and the mouth — are secondary constructions, formed from the outer skin. In the horn-plate, at the spot where the mouth is found subsequently, a pit-like depression is formed, and this grows deeper and deeper, pushing towards the blind fore-end of the capital cavity ; this is the mouth-pit. In the same way, at the spot in the outer skin where the anus is afterwards situated a pit-shaped depression appears, grows deeper and deeper, and approaches the blind hind-end of the pelvic cavity ; this is the anus-pit. In the end these pits touch with their deepest and innermost points the two blind ends oi the primitive alimentary canal, so that they are now only separated from them by thin membranous partitions. Hence at first, if we penetrate into these pits from without, we find a partition cutting them off from the cavity of the alimentary canal, which gradually disappears. The formation of mouth and anus is secondary in all the vertebrates. smaller, and at last hangs out like a little pouch from the middle of the gut by a thin pedicle, the vitelline duct (Fig. 147 ds). This vitelline duct has no permanent importance ; it is afterwards, like the yelk-sac, completely atrophied and used up. Its contents are taken into the gut, while the duct itself grows. The point at which it connects with the gut is the visceral navel. Here in the end the alimentary canal closes up altogether. (Cf. Chapter XV. and Fig. 154 ; also Plate VII., Figs. 14, 15.) formation of the intestinal wall and ventral wall, we find a number of other interesting changes taking place in the embryonic shield of theamniotes. These relate chiefly to the prerenal ducts and the first blood-vessels. The prorenal (primitive kidney) ducts, which at first lie quite flat under the horn-plate or epiderm (Fig. 141 ling), soon back towards each Fig. 155.— Transverse section of a human embryo of fourteen days. mr medullary tube, ch chorda, vtt umbilical vein, ml myotome, mf> middle plate, ug prorenal duct, lh body-cavity, <• ectoderm, Ith ventral skin, /;_/" skinfibre layer, df gut-fibre layer. ( From Kallmann. ) vein, ml myotome, mm muscular mass o( the provertebra, m/> middle plate, ug prorenal duet, lh body-cavity, e ectoderm of the rudimentary extremities, ma mesenchymic cells, a point where the myotome and nephrotome separate. I From II. E. Ziegler. ) other in consequence of special growth movements (Figs. 14S 150 ung). The direction they take in this corresponds to the limit between the dorsal body and the ventral body (cf. Figs. 155 and 156). While they advance between the stem-zone and parietal zone of the embryonic shield of the amniote, they depart more and more from their point of origin, and approach the gut-gland layer. In the end they lie deep in the interior, on either side of the mesentery, underneath the chorda (Fig. 150 ung). At the same time the two primitive aortas change their position (cf. Figs. 141150 ao); they travel inwards underneath the chorda, and there coalesce at last to form a single secondary aorta, which is found under the rudimentary vertebral column (Fig. 150 ao). primitive segments. (From Balfour.) From a dorsal lateral joint of the medullary tube (spc) the spinal knots (spg) grow out between it and the hornplate, ch chorda, ao double aorta, liy gut-gland layer, sp gut-fibre layer, with blood-vessels in section, ms muscle plate, in the dorsal wall of the myoccel (episomite). Below the cardinal vein (cav) is the prerenal duct (tvd) and a segmental prerenal canal fs/J. The skin-fibre layer of the body-wall (so) is continued in the amniotic fold (am). Between the four secondary germinal layers and the structures formed from them there is formed embryonic connective matter with stellate cells and vascular structures. [Her twig's " mesenchym.") The cardinal veins, the first venous blood-vessels, also back towards each other, and eventually unite immediately above the rudimentary kidneys (Figs. 150 vc, 157 cav). In the same spot, at the inner side of the fore-kidneys, we soon see the first trace of the sexual organs. The most important part of this apparatus (apart from all its appendages) is the ovarj in the female and the testicle in the male. Both develop from a small part of the ceelous epithelium, the cellcovering o( the body-cavity, at the spot where the skin-fibre layer and gut-fibre layer touch. The connection of this embryonic gland with the prorenal ducts, which lie close to it and assume most important relations to it, is only secondary. (Cf. Chapter XXIX. and Plate VI., Figs. 4-8.) THIRTEENTH TABLE SYNOPSIS OF THE COMPOSITION OF THE VERTEBRATE-BODY FROM DORSAL AND VENTRAL BODY, HEAD-HALF AND TRUNK-HALF PLATES VI. AND VII. N.B. The ectoderm (skin-sense layer) is coloured orange, the dorsal mesoderm (in the episoma) blue, the ventral mesoderm (in the hyposoma) red, and the entoderm (gut-gland layer) green. EXPLANATION OF PLATES VI. AND VII. The Plates VI. and VII. are intended to give a partly ontogenetic and partly phylogenetic explanation of the construction of the human body from the germinal layers. Plate VI. contains only diagrammatic transverse sections (through the saggital and the transverse axis); Plate VII. contains only diagrammatic longitudinal sections (through the sagittal and the long axis), seen from the left. The primary layers and their products are marked by the same colours throughout, the skin-sense layer orange and the gut-gland layer green. The mesoderm and its products are blue in the episoma, or dorsal body ; and red in the hyposoma, or ventral body. The letters have the same meaning throughout. In all the figures the dorsal surface of the body is upward, and the ventral surface downward. VERTEBRATES. Fig. i. Transverse section of the gastrula of a primitive vertebrate (amphioxus, of. Fig. 10, Plate VII., longitudinal section, and Figs. 40 and 41 1. The whole body is an alimentary canal (d) ; the wall of it consists only of the two primary layers. Fig. 2. Transverse section of the eoelomula of a primitive vertebrate (amphioxus) at the commencement of ccelomation. The dorsal wall of the primitive gut (du) divides into the rudiments of the median chorda (ch) and the two ccelom-pouches(V/J. The neural tube ( 11) begins to separate from the corneous plate (c). (Cf. Figs. S2-S4. ) chorda (ch) lies between the dorsal nerve-tube (n) and the ventral guttube (d). The ccelom-pouch still simple in the left (younger) half ( ct ) ; in the right (older) half it is divided by the lateral furrow into a dorsal muscular pouch (myoccel, cm) and a ventral sexual pouch (gonoccel, eg), nip muscleplate, gp sexual-plate, / corium-plate, /; horn-plate (outer skin). spondylus or vertebrcea, p. 251). The ccelom-pouch is still simple in the left (younger) half, and opens outwardly by a prorenal canal fas J into the lateral prorenal groove fur J; in the right (older) half the dorsal part, or muscular pouch frw J, is divided from the ventral part, or sexual pouch (eg) ; the latter opens by a prorenal canal (us) into the prorenal duct ( u ), which has separated from the the horn-plate (h). The right and left body-cavities arc -.till separate. In the gut-fibre wall we see the first blood-vessels, the arteries above (aorta, an) and veins below (principal or subintestinal vein, hi). ell chorda, 11 medullary tube, d alimentary tube, gp sexual plate, nip muscular plate, / corium-plate, /; horn-plate. also (formed from the middle part of the dorsal ccelom-pouch) is more advanced, and forms independent "prevertebral halves" (lak). As in Fig. 4, it is assumed as a matter of hypothesis that the cceloma originally opens outwards (to the left ?) by segmental canals (pronephridia), but afterwards (to the right ') the dorsal and ventral ccelom-pouches are quite separate. (Cf. the section in Fig. i.s(>. 1 Fig. t>. Transverse section of the germinal disk of an amniote (or higher vertebrate), with rudiments of the first organs. (Cf. the section of the chick on the second day of incubation, Fig. 141. 1 Tin- medullary tube (») and tin- prerenal ducts (u)art separated from the horn-plate (h). At each siilo of tin' chorda (eh) the provertebrae ( n-r ) and the lateral plates are differentiated. Between the skin-fibre layer (hf) and the gut-fibre layer (df) we see the first formation of t le body-cavity or cceloma (eg); underneath it aro the two primary aortas (no). Fig. 7. Transverse section of the germinal disk of the same amniote, a little further advanced than Fig. .;. (Cf. the section of the chickembryo on the third day of incubation, Fig. 148. 1 Medullary tube ( 11 ) and chorda ( 'eh ) already begin to be enclosed by the provertebrae (ma). The prerenal ducts (u) are already completely separated from the horn-plate (h ) bv the corium-plate ( I )■ c body-cavity, <t« aortas. The cutaneous layer rises up round the embryo in the shape of the amniotic fold (am) ; this gives rise to a space between the amniotic fold and the wall of the yelk-sac (ilsj. the pericoel (serocoslom) or extra-foetal cceloma (ex). Fig. s. Transverse section of the pelvic region and the hind limbs of the embryo of an amniote. I Cf. the section of a chick-embryo on the fifth day of incubation, in Chapter XIV. ) The medullary tube (n) is already entirely enclosed by the two arches of the vertebra (wb),a.n6 the chorda and its sheath by the two halves of the body of the vertebra ( :vk ). The corium-plate (I) has separated completely from the muscular plate (mp). The horn-plate (h) is much thickened at the point oi tin- hind legs ()• The sexual parts (g) extend far into the body-cavity (c), and lie close to the prerenal duet (11). The alimentary tube ( il ) is fastened by a mesentery (I), under the chief aorta (no) and the two cardinal veins ( vc ), to the dorsal surface of the bodywall. Below, in the middle of the ventral wall, we see the pedicle of the allantois (ctf). vertebra. From the vertebra an arched rib trees to right and left, and Strengthens the breast-wall ( rp ). Below, oil the ventral surface, the breastbone or sternum (lib) lies between right ami left ribs. The pectoral cavity (or fore part of the cceloma, c) is, for the most part, occupied by the lungs (In ). in which the tubes ramify like the branches of a tree. All these open together into the single larynx ( Ir ), which opens at tin' neck into the pharynx (sr). The (ao) lies between the alimentary canal and tin' vertebral column. Between the trachea and the sternum is tin- heart, divided into two halves by a partition. The left half ( hi ) contains only arterial and the right ( lir ) only venous blood. Each half of the heart is divided bv a valve into an auricle and ventricle. The heart is represented diaijrammatically in lis (phylogenetically) original symmetrical situation (in the middle of the ventral sulci. In the developed man and the ape the heart is unsynunctrically and obliquely placed, the apex being drawn to the left. Fig. 10. Longitudinal section of the gastrula of a primitive vertebrate (amphioxus, cf. Fig. I, Plate VI., transverse section, and Figs. 40, 41). The primitive gut-cavity opens at the back by the primitive mouth (an). The body consists only of the two germinal layers. At the ventral border of the primitive mouth one of the two large polar cells of the mesoderm can be seen (ccelom pole-cells, cp). Figs. 101-105), from the left side. The axial chorda (ch) divides the episoma from the hyposoma. In the head half we have the brain ( nc) above and the gill-gut ( is) below, with eight pairs of gill-clefts ; in the trunk half the medullary tube (nr) and the muscle-plates (nip) above and the segmental gonades (g) below, a anus, o mouth, ink mouth-cavity, q sense organs, hz heart. close relation of the actual sharks and the hypothetical ancestors of man. (The fins are omitted.) The medullary tube has divided into the five primitive cerebral vesicles (n-^-n^) and the spinal marrow (nr) (cf. Figs. 15, 16). The brain is enclosed by the skull (s), and the spinal marrow by the vertebral canal (above the marrow the vertebral arches, wb ; underneath it the bodies of the vertebra;, wk; under these again the source of the ribs is indicated). In front a sense-organ ( ' q ) has developed from the horny plate. The alimentary canal (d) has divided into the following parts : mouth-cavity ( mh), gulletcavity with eight pairs of gill-clefts (is), floating-bladder (= lungs, lu), oesophagus (sr), stomach (mg), liver (lb) with the gall-bladder ( iv), small intestine (dd) and rectum with anus (a). Under the rectum is the sexual gland ( g ); higher up, the primitive kidneys (us). Under the gullet-cavity lies the heart, with auricle (hv) and ventricle (hi). showing the relation of the alimentary canal to the appendages. In the middle the long-stalked yelk-sac (or umbilical vesicle, ds) arises from the alimentary canal ; behind, the long-stalked allantois ( al) also proceeds from the canal. Beneath the fore-gut is the heart (lis), ah amniotic cavity. The ventral part of the amnion (ah) encloses the pedicle of the lecithom and the allantois (umbilical cord). Fig. 15. Longitudinal section of a human embryo of five weeks (cf. Fig. 14). The amnion, the placenta, and the urachus are omitted. The medullary tube has divided into the five primitive cerebral vesicles (n-y-n.) and the spinal marrow (nr, cf. Figs. 13 and 16). The brain is enclosed by the skull (s) ; under the spinal marrow is the series of the vertebral bodies (wi). The alimentary canal has been differentiated into the following sections: gullet-cavity with three pairs of gill-clefts (is), lungs ( lit), oesophagus (sr), stomach (mg), Uver(lb), small intestine (dd) into which the yelk-sac ( ds) opens, urinary bladder (hb), and rectum, hs heart. The remainder of the tail is still clearly seen to the right below. Fig. i". Longitudinal section of a developed human female body. All tlu- parts are fully developed, but diagrammatically reduced and simplified in order to show more clearly the arrangement and the relation to the four secondary germ-layers. In the brain the five original vesicles (Fig. 15, n, n . 1 have separated and developed in the manner peculiar to the higher mammals : «, Fore-brain or cerebrum (preponderating over and covering the other lour) ; «.. intermediate-brain or- optic thalami ; n., middle brain or corpora quadrigemina ; n , hind-brain or cerebellum; «. after-brain or pons Varoii, passing into the spinal corA(nr). The brain is enclosed by the s\oM.(s), t lie spinal cord by the vertebral canal ; above the cord are the vertebral arches and spinal processes (:^bj. beneath it the bodies of the vertebrae (ink). The alimentary canal lias boon divided into the following successive sections: mouth-cavity, gullet-cavity (in which the gill-clefts, is. were Formerly), windpipe ( lr ) with lungs (hi), oesophagus (sr ), stomach ftngj, liver ( lh ) with gall-bladder ( iv), pancreas ( p), small intestine ( <ld ) and large intestine- (dc), rectum and amis (a). The body-cavity or coeloma (c) is divided by the diaphragm (:) into two — the thoracic-cavit} fej,m which we have the heart ( liz ) in front of the lungs; and the abdominal-cavity, in which are most of the viscera. In front of the rectum is the female vagina ( vg ), which leads into the womb (uterus, f) ; in this the embryo (indicated by a small embryonic vesicle, em) developes. Between the uterus and the os pubis ( sb ) lies the bladder ( hh ), the remainder of the pedicle of the allantois. The horn-plater'/;,) covers the entire hotly as the epidermis, and also lines the cavities of the mouth, the anus, the vagina, and the womb. The mammary gland (md)a\so was originally formed from the corneous plate. NOTE.— The four colours that are used on Plates VI. and VII. in explaining human organogenesis only correspond in purl to the four secondary germinal layers. The skin-sense (cutaneous sensory) layer is orange, the gut-gland (intestino-glandular) layer green. On the other hand, nil organs are blue iii THE ARTICULATION OF THE BODY Metamerism or articulation of the body of the higher animals : division into a chain of segments or consecutive parts. Internal articulation of the vertebrates and external segmentation ot~ the articulates resemble each other, but differ profoundly. Beginning of articulation of the amniotes in the middle of the embryonic shield. Increase of the somites or primitive segments from front to back. Their number in man. Segments of the head and of the trunk. Articulation of the amphioxus. Severance of the somites from the fore-end of the ccelom-pouches. Division of each primitive segment into a dorsal (myotome) and a ventral (gonotome) half. Segmentation of the craniotes : segmental protovertebral plates and unarticulated lateral plates. Differentiation of the metamera in the fishes, amphibia, and amniotes. Segmentation of the episoma and hyposoma. Original metamerism of the gonades and nephridia. Articulation of the fore-gut : gill clefts and arches. Primary and secondary metamerism. Monomeric organs : heart, lungs, liver, sense-organs, limbs. Similarity of vertebrate-embryos and its phylogenetic significance. The vertebrate stem, to which our race belongs as one of the latest and most advanced outcomes of the natural biogenetic process, is rightly placed at the head of the animal kingdom. This privilege must be accorded to it, not only because man does in point of fact soar far above all other animals, and has been lifted to the position of "lord of creation"; but also because the vertebrate organism far surpasses all the other animal-stems in size, in complexity of structure, and in the advanced character of its functions. From the point of view of both morphology and physiology, the vertebrate phylum (stem) outstrips all the other, or invertebrate, animals. There is only one among the twelve stems of the animal kingdom that can in many respects be compared with the vertebrates, and reaches an equal, if not a greater, importance in many points. This is the stem of the articulates, composed of three classes: i. The annelids (rain-worms, leeches, and cognate forms) ; 2. The Crustacea (crabs and tortoises, etc.) ;. 3. The tracheata (peripatida, myriapods, spiders, and insects). The phylum of the articulates is superior not only to the in the economy of nature. When we have thus declared the vertebrates and the articulates to be the most important and most advanced of the twelve stems of the animal kingdom, the question arises whether this special position is accorded to them on the ground of a peculiarity of organisation that is common to the two. The answer is that this is really the case ; it is the segmental or transverse articulation, which we may briefly call metamerism. In all the vertebrates and articulates the developed individual consists of a series of successive members (segments or metamera = " parts") ; in the embryo these are called primitive segments or somites. In each of these metamera we have a certain group of organs reproduced in the same arrangement, so that we may regard each segment as an individual unity, or a special " individual " subordinated to the entire personality. The similarity of the morphological segmentation, and the consequent physiological advance in the two stems of the vertebrates and articulates, has led to the assumption of a direct affinity between them, and an attempt to derive the former directly from the latter. The annelids were supposed to be the direct ancestors, not only of the Crustacea and tracheata, but also of the vertebrates. We shall see later (Chapter XX.) that this annelid theory of the vertebrates is entirely wrong, and ignores the most important differences in the organisation of the two stems. The internal articulation of the vertebrates is just as profoundly different from the external metamerism of the articulates as are their skeletal structure, nervous system, vascular system, and SO on. The metamerism has been developed in a totally different way in the two stems. The unarticulated chordula (Figs. 86-89), which we have recognised as one of the chief palingenetic embryonic forms of the vertebrate group, and from which we have inferred the existence of a corresponding ancestral form for all the vertebrates and tunicates, is quite unthinkable as the stem-form of the articulates. All articulated animals came originally from unarticulated ones. This phylogenetic principle is as firmly established as the ontogenetic fact that every articulated animal-form developes from an unarticulated embryo. But the organisation of the embryo is totally different in the two stems. The palingenetic chordula-embryo of all the vertebrates is characterised by the dorsal medullary tube, the neurenteric canal, which passes at the primitive mouth into the alimentary canal, and the axial chorda between the two. None of the articulates, either annelids or arthropods (crustacea and tracheata), show any trace of this type of organisation. Moreover, the development of the chief systems of organs proceeds in the opposite way in the two stems, as is shown in Table XIV. Hence the typical metamerism of the two stems must have been acquired independently of each other. This is not at all surprising ; we find analogous cases in the stalk-articulation of the higher plants and in several groups of other animal stems — for instance, in the tape-worm and gunda (among the platodes), in the star-fish and encrinite (among the echinoderms), in the scyphostoma (among the cnidaria), and so on. The characteristic internal articulation of the vertebrates and its importance in the organisation of the stem are best seen in the study of the skeleton. Its chief and central part, the cartilaginous or bony vertebral column, affords an obvious instance of vertebrate metamerism ; it consists of a series of homogeneous cartilaginous or bony pieces, which have long been known as vertebra? (or spondyli). Each vertebra is directly connected with a special section of the muscular system, the nervous system, the vascular system, etc. Thus most of the " animal organs " take part in this vertebration. But we saw, when we were considering our own vertebrate character (in Chapter XL), that the same internal articulation is also found in the lowest primitive vertebrates, the acrania, although here the whole skeleton consists merely of the simple chorda, and is not at all articulated. Hence the primary articulation does not proceed from the skeleton, but from the muscular system, and is clearly phylogenetically 1 1 is, therefore, wrong to describe the first rudiments of the metamera in the vertebrate embryo as primitive vertebras or proloroertebrce ; the fact that they have been so called for some time has led to much error and misunderstanding. Hence we shall give the name of "somites" or primitive segments to these so-called "primitive vertebrae." If the latter name is retained at all, it should only be used of the sclerotom — i.e., the small dorso-medial part of the somites from which the later vertebra does actually develop. Articulation begins in all vertebrates at a very early embryonic stage, and this indicates the considerable phylogenetic age of the process. When the chordula (Figs. 86-89) has completed its characteristic composition, often even a little earlier, we find in the amniotes, in the middle of the sole-shaped embryonic shield, several pairs of dark square spots, symmetrically distributed on both sides of the chorda (Figs. 134-138). Transverse sections (Fig. 141 uw) show that they belong to the stem-zone (episoma) of the mesoderm, and are separated from the parietal zone (hyposoma) by the lateral folds; in section they are still quadrangular, almost square, so that they look something like dice. These pairs of " cubes " of the median mesoderm are the first traces of the primitive segments or somites, the so-called " protovertebras " ( Figs. 158-160 uw). Among the mammals the embryos of the marsupials have three pairs of somites (Fig. 134) after sixty hours, and eight pairs after seventy-two hours (Fig. 138). They develop more slowly in the embryo of the hare; this has three somites on the eighth day (Fig. 135), and eight somites a day later (Fig. [37). In the incubated hen's egg the first somites make their appearance thirty hours after incubation begins (Fig. 158). At the end of the second day the number has risen to sixteen or eighteen (Fig. 160). The articulation of the mesodermic stem-zone, to which the somites owe their origin, thus proceeds briskly from front to rear, new transverse constrictions o( the " protovertebral plates " forming continuously and successively. The first segment, which is almost halfway down in the embryonic shield of the amniote, is the foremost of all; from this first somite is formed the first cervical vertebra with its muscles and skeletal parts. It follows from this, firstly, that the multiplication of the primitive segments proceeds backwards from the front, with a successive stages of development, looked at from the dorsal surface, magnified about twenty times, somewhat diagrammatic. Fig". 158 with six pairs of somites. Brain a simple vesicle (lib). Medullary furrow still wide open from x ; greatly widened at c. mp medullary plates," sp lateral plates, y limit of gullet-cavity ( sh ) and fore-gut ( vd ). Fig. 159 with ten pairs of somites. Brain divided into three vesicles : v fore-brain, m middle-brain, h hind-brain, r heart, dv yelk-veins. Medullary furrow still wide open behind (z), mp medullary plates. Fig. 160 with sixteen pairs of somites. Brain divided into five vesicles : v fore-brain, c intermediate-brain, m middle-brain, /; hind-brain, ii after-brain, a optic vesicles, g auditory vesicles, c heart, dv yelk-veins, mp medullary plate, uw primitive vertebra. constant lengthening of the hinder end of the body; and, secondly, that at the beginning of segmentation nearly the whole o( the anterior half of the sole-shaped embryonic shield of the amniote belongs to the later head, while the whole o\ the rest of the body is formed from its hinder half. We are reminded that in the amphioxus (and in our hypothetic primitive vertebrate, Figs. 101-105) nearly the whole o( the fore half corresponds to the head, and the hind half to the trunk. The mesoderm of the amniote head developes from the undivided " head-plates," which are clearly distinguished from the protovertebral plates of the trunk by the absence of articulation. But we shall sec that this simplicity of the head-plates is not original, but cenogenetic. In the lower vertebrates even the head-part seems to be clearly articulated, and composed of at least nine somites ; and in the embryo of certain palingenetic fishes as many as twelve to fourteen headsegments have recently been found. But in the higher vertebrates these head-somites (like head-metamera of the higher articulates) fuse together at such an early stage that it took the acute observations of Gegenbaur (1872) to prove them by comparative anatomic methods. The proof was afterwards confirmed by others with the aid of comparative ontogeny. We shall return to the point in discussing the theory of the skull in Chapter XXVI. The number of the metamera, and of the embryonic somites or primitive segments from which they develop, varies considerably in the vertebrates, according as the hind part of the body is short or is lengthened by a tail. In the developed man the trunk (including the rudimentary tail) consists of thirty-three metamera, the solid centre of which is formed by that number of vertebra? in the vertebral column (seven cervical, twelve dorsal, five lumbar, five sacral, and four caudal). To these we must add at least nine headvertebras, which originally (in all the craniota) constitute the skull. Thus the total number of the primitive segments of the human body is raised to at least forty-two; it would reach forty-five to forty-eight if (according to recent investigations) the number of the original segments of the skull is put at twelve to fifteen. In the tailless or anthropoid apes the number of metamera is the same as in man, and only differs by one or two; but it is much larger in the long-tailed apes and most of the other mammals. In long serpents and fishes it reaches several hundred (sometimes 400). In order to understand properly the real nature and origin of articulation in the human body and that of the higher vertebrates, it is necessary to compare it with that of the lower vertebrates, and bear in of the craniota. Here, too, it is the masterly studies of Hatschek (of Vienna) that put most clearly before us these remarkable features of the lowest craniotes. The two ccelom-pouches have hardly grown out of the primitive gut (Fig. 161 c) when the blind fore part of it (farthest away from the primitive mouth, it) begins to separate by a tranverse fold (s): this is the first primitive segment. Immediately afterwards the hind part of the ccelom-pouches begins to divide into a series of pieces by new transverse folds (Fig. 162). The transverse constrictions of the ccelom-pouches lie in a plane vertical to the long axis, and begin at their dorsal side (Fig. 163). Proceeding downwards from there, they cut each other municates by a narrow opening with the gut, like an intestinal gland. But this opening soon closes by complete severance, proceeding regularly backwards. The closed vesicular somites then extend more, so that their upper half grows upwards like a fold between the ectoderm (ak ) and neural tubef//), and the lower half between the ectoderm and alimentary canal (ah; Fig. 167 c, left half of the figure). Afterwards Figs, to.' and 163.— Embryo of the amphioxus, twenty hours old, with five somites. Fig. 162 left view, Fig-. 163 right view. (From Hatschek.) V torf end, // hind end, ut, mi, ik outer, middle, and inner germinal layers; ,11, alimentary canal, n neural tube, en canalis neurentericus, „sh ccelompouches (or primitive segment cavities), us first (and foremost) primitive segment. the two halves completely separate, a lateral longitudinal fold cutting between them (mk, right half of Fig. 167). The dorsal segments ( sd ) provide the muscles of the trunk the whole length of the body (Fig. 165) : this cavity afterwards disappears. On the other hand, the ventral With eight Somites. (From Hatschct. ) Figs. 164 and 165 lateral view (from left). Fig. 166 seen from back. In Fig. 164 only the outlines of the eight primitive segments are indicated, in Fig. 165 their cavities and muscular walls, ("fore end, H hind end, d gut, du under and dd upper wall of the g-ut, ne canalis neurentericus, uv ventral, nd dorsal wall of the neural tube, ///> neuroporus, dv fore pouch of the gut, ch chorda, mf mesodermic fold, pin polar cells of the mesoderm ( >>is ), e ectoderm. somites give rise, from their uppermost section, to the pronephridia or prerenal canals, and from the lower to the segmental rudiments of the sexual glands or gonades. The partitions of the muscular dorsal pieces (myotomes ) remain, and determine the permanent articulation of the vertebrate organism. But the partitions of the extensive ventral pieces ( gonotomes ) become thinner, and afterwards disappear in The articulation proceeds in substantially the same way in the other vertebrates, the craniota, starting from the ecelompouches. But whereas in the former case there is first a transverse division oi the coelom-sacs (by vertical folds) and then the dOrso-ventral division, the procedure is reversed in the craniota; in their case each of the long ccelom-pouches first divides into a dorsal (primitive segment plates) and a ventral (lateral plates) section by a lateral longitudinal fold. Only the former are then broken up into primitive segments by the subsequent vertical folds; while the latter (segmented for a time in the amphioxus) remain undivided, and, by the divergence of their parietal and visceral plates, form a bodycavity that is unified from the first. In this case, again, it is clear that fig. 167. —Transverse „,. _„_♦ „^T., .. 1 .1,, 1%.,,,,., ,r .1, , section of the middle of an we must regard the features of the amphioxus -embryo with Chapter XXL). In particular, the development of their muscular segments (from the dorsal somites) is nearer to that oi the amphioxus than of the other vertebrates (the gnathostoma). This is connected with the fact that the cyclostoma, like the acrania, have no vertebral column, and that the articulation of the body is very simple and primitive in both groups ; the formation of the head, especially, remains at a very low stage, and there arcno pairs of limbs. These embryonic processes are much more complex in the fishes, with which begins the long pairs of extremities. Among the fishes the selachii, or primitive fishes, yield the most important information on these and many other phylogenetic questions (Figs. 168, 169). The careful studies of Riickert, Van Wijhe, H. E. Ziegler, and others, have given us most valuable results. The products of the middle region of the kidneys). (From Wijhe and Hertwig.) In Fig. 16c, the dorsal segment-cavities (h) are already separated from the body-cavity ( II: j. but they are connected a little earlier (Fig. 16S). nr neural tube, ch chorda, sch subchordal string, no aorta, sk skeletal plate, nip muscle-plate, cp cutis-plate w connection of latter (growth-zone), vn primitive kidneys, Kg-prorenal duct, uk prerenal canals, lis point where they are cut off', tr prerenal funnel, ink middle germ-layer {mk2 parietal, ink., visceral), it inner germ-layer (gut-gland layer). germinal layer are partly clear in these cases at the period when the dorsal primitive segment cavities (or tnyocoels, //) are still connected with the ventral body-cavity (l/i : Fig. 168). In Fig. 169, a somewhat older embryo, these cavities are separated. The outer or lateral wall of the dorsal segment yields the cutis-plate (cp), the foundation of the connective corium. From its inner or median wall are developed the muscle-plate ( mp, the rudiment of the trunk-muscles) and In the amphibia, also, especially the water-salamander ( triton ), we can observe very clearly the articulation of the coelom-pouches and the rise of the primitive segments from their dorsal half (ci. Fig. 04, A, B, C). The cavity o( the originally simple coelom-sacs (Fig. 94 A and right half of H ) remains visible both in the dorsal and ventral segments, even after the two have been separated by the lateral fold (Fig. 04 C and left half oi li ). A horizontal longitudinal or frontal section of this salamander-embryo (Fig. 170) shows very clearly the scries of paii> of these vesicular dorsal segments, which have been cut off on each side from the ventral side-plates, and lie to the right and left of the chorda. cavity, ak horn plate. Fig. 171.— Transverse section of a chick-embryo of the second day of incubation. (From KSUiker.) mr medullary tube, ch chorda, uw protovertebra, ung prorenal ducts, u" primitive aorta, //:.'// prevertebral cavity, mi primitive kidneys, h horn-plate, o/amniotic told, lip skin-fibre layer, <^ gutfibre layer, /> COilom, till yelk-gland layer. considered ; but it varies considerably in detail, in consequence of cenogenetic disturbances that are due in the first place (like the degeneration o( the ccelom-pouches) to the large development of the food-yelk. As the pressure of this seems to force the two middle layers together from the start, and as the solid structure of the mesoderm apparently belies the original hollow character of the sacs, the two sections of the mesoderm, which are at that time divided by the lateral fold — the dorsal segment-plates and ventral side-plates — have the appearance at first of solid laminae of cells (Figs. 97-100). And when the articulation of the somites begins in the soleshaped embryonic shield, and a couple of protovertebrae are day, magnified about one hundred times. The protovertebrse have split into the outer muscle-plate ( mpj and the inner skeletal plate. The latter begins to enclose the chorda ( ch ) below as the body of the vertebra; f'v/ij, and the medullar}- tube ( m ) above as the arch of the vertebrae (ivb), the cavity of the medullary tube ( m/i J being- now very narrow. At «-y the muscular plate advances into the ventral wall ( lip ), hpr corium-plate or dorsal wall, h horny plate, a amnion, ung prorenal duct, un prorenal canals, ao primitive artery (aorta), vc cardinal vein, df gut-fibre layer, dd gut-gland layer, dr alimentary groove. developed in succession, constantly increasing in number towards the rear, these cube-shaped somites (formerly called protovertebrae, or primitive vertebrae) have the appearance of solid dice, made up of mesodermic cells (Fig. 141). Nevertheless, there is for a time a ventral cavity, or prevertebral cavity, even in these solid "protovertebrse" (Fig. 157 uwh). This vesicular condition of the provertebra is of the greatest phylogenetic interesl ; we must, according to the coelom theory, regard it as an hereditary reproduction of the vesicular dorsal somites of the amphioxus (Figs. 161-167) and the lower vertebrates (Figs, 168-170). This rudimentary " prevertebral cavity " has no physiological significance whatever in the amniote-embryo ; it soon disappears, being tilled up with cells of the muscular plate. Another variation in the formation of the segments in the amniotes is that the development of the muscular plates from the inner (median) wall of their somites spreads to the outer (lateral) wall ; hence here the cell-stratum of the " skin-fibre layer," which lies directly below the cutis-plate (the later corium-plate, Fig. 169 cp), also takes a lively part in the further growth of the muscular plate. It grows out on all sides from this point, especially downwards into the lateral plates of the ventral wall (the ventral plates). The innermost median part of the primitive segment plates, which lies immediately on the chorda (Fig. 172 c/i) and the medullary tube f»ij, forms the vertebral column in all the higher vertebrates (it is wanting in the lowest) ; hence it may be called the skeleton plate. In each of the provertebra; it is called the "sclerotome" (in opposition to the outlying muscular plate, the " myotome"). From the phylogenetic point of view the myotomes are much older than the sclerotomes. The lower or ventral part of each sclerotome (the inner and lower edge of the cube-shaped provertebra) divides into two lamina;, which grow- round the chorda, and thus form the foundation of the body of the vertebra (wh). The upper lamina presses between the chorda and the medullary tube, the lower between the chorda and the alimentary canal (Fig. 142 C). As the laminae of two opp site prevertebral pieces unite from the right and left, a circular sheath is formed round this part of the chorda. From this developes the body oi' a vertebra — that is to say, the massive lower or ventral half of the bony ring, which is called the "vertebra" proper and surrounds the medullary tube (Figs. 173 173). The upper or dorsal half of this bony ring, the vertebral arch (Fig. 172 wb) arises in just the same way from the upper part of the skeletal plate, and therefore from the inner and upper edge of the cube-shaped primitive vertebra. As the median upper edges of two opposing somites grow together over the medullary tube from right and left, the vertebral arch becomes closed. The whole of the secondary vertebra, which is thus formed from the union of the skeletal plates of two provertebral pieces and encloses a part of the chorda in its body, consists at first of a rather soft mass of cells ; this afterwards passes into a firmer, second, cartilaginous stage, and finally into a third, permanent, bony stage. These three stages can generally be distinguished in the greater part of the skeleton of the higher vertebrates ; at first most parts of Fig. 174. Fig, -The third cervical vertebra (human). -The sixth dorsal vertebra (human). -The second lumbar vertebra (human). finally ossify. At the head part of the embryo in the amniotes there is not generally a cleavage of the middle germinal layer into provertebral and lateral plates, but the dorsal and ventral somites are blended from the first, and form what are called "the head-plates" (Fig. 153 k). From these are formed the skull, the bony case of the brain, and the muscles and corium of the body. The skull developes in the manner of the membranous vertebral column. The right and left halves of the head curve over the cerebral vesicle, enclose the foremost part of the chorda below, and thus finally form a simple, soft, membranous capsule about the brain. This is afterwards converted into a cartilaginous primitive skull, such as we find permanently in many o\ the fishes. Much later this cartilaginous skull becomes the permanent bony skull with its various parts. The bony skull in man and all the other amniotes is more highly differentiated and modified than that of the lower vertebrates, the amphibia and fishes. But as the one has arisen phylogenetically from the other, we must assume that in the former no less than the latter the skull was originally formed from the sclerotomes of a number oi (at least nine) head-somites. While the typical articulation of the vertebrate body is always obvious in the episoma or dorsal body, and is clearly expressed in the metamerism of the muscular plates and vertebrae (myotomes and sclerotomes), it is more latent in the hyposoma or ventral body. Nevertheless, these ventral hyposomites of the vegetal half of the body are not less important than the episomites of the animal half. The segmentation in the ventral cavity affects the following principal systems of organs : i. The gonades or sex-glands (gonotomes) ; 2. The nephridia or kidneys (nephrotomes) ; and 3. The head-gut with its metamerous gill-clefts (branchiotomes). (Plate VII., Fig. 12.) The metamerism of the hyposoma is less conspicuous because in all the craniotes the gonocoels — the cavities of the ventral segments, in the walls of which the sexual products are developed — have long since coalesced, and formed a single large body-cavity, owing to the disappearance of the partition. This cenogenetic process is so old that the metaccel in the lateral plates of the craniota has everywhere the appearance from the first of a simple unsegmented cavity, and that the rudiment of the gonades also is almost always unsegmented. It is the more interesting to learn that, according to the important discovery of Riickert, this sexual structure is at first segmental even in the actual selachii, and the several gonotomes only blend into a simple sexual gland on either side secondarily. Amphioxus, the sole surviving representative of the acrania, once more yields us most interesting information; in this case the sexual glands remain segmented throughout life, and so do the ventral body-cavities. The sexually mature lancelet has, on the right and left of the gut, a series of metamerous sacs, which are filled with ova in the female and sperm in the male. These segmental gonades are originally nothing else than the real gonotomes, separate body-cavities, formed from the hyposomites of the trunk. The reason why they have hitherto generally been misunderstood, and the amphioxus has wrongly been credited with a simple body-cavity, is that the latter has been confused with the large peribranchial space. The gonades are the most important segmental organs of the hyposoma, in the sense that they are phylogenetically the oldest. We find sexual glands (as pouch-like appendages of the gastro-canal system) in most of the coelenteria, even in the cnidaria (medusa;), which have no nephridia. The latter appear first (as a pair of prorenal canals or excretory tubes) in the platodes (turbellaria), and have probably been inherited from these by the articulates (annelids) on the one hand and the unarticulated prochordonia on the other, and from these passed to the articulated vertebrates. The oldest form of the renal system in this stem are the segmental pronephridia or the metamerous prorenal canals, in the same arrangement as Boveri found them in the amphioxus. They are small canals that lie in the frontal plane, on each side of the chorda, between the episoma and hyposoma (Fig. 176 n); their internal funnel-shaped opening leads into the various body-cavities, their outer opening is the lateral furrow of the epidermis. Originally they must have had a double function, the carrying away of the urine from the myoccel of the episomites and the release of the sexual cells from the gonoccel of the hyposomites. The recent investigations of Riickert and Van Wijhe on the mesodermic segments of the trunk and the excretory system of the selachii show that these " primitive fishes " are closely related to the amphioxus in this further respect. The transverse section of the shark-embryo in Fig. 168 shows the dorsal and ventral halves of the ccelom-pouches still openly connected. In the middle of the section, in the frontal axis, the narrow myoccel (or cleft-like " muscular cavity " of the dorsal segment) passes by a narrow connecting channel (vb ) directly into the wide gonoccel (Hi) or the body-cavity of the ventral segment, from the epithelium o( which sexual cells develop. The narrow connecting channel (vb) becomes the pronephridium, or prerenal canal, which carries away the excretory products of both body-cavities (the urine of the dorsal muscular cavity and the sexual cells of the ventral sexual cavity). Afterwards (Fig. 169) the two cavities are divided by a partition. Then structures, which have been secondarily derived from the segmental pronephridia of the acrania. The parts of the mesoderm at which the first traces of them are found are usually called the middle or mesenteric plates, and their segmental parts mesornera. As the first traces of the gonades make their appearance in the ccelous epithelium o( these middle plates nearer inward (or the middle) from the inner funnels of the nephro-canals, it is better to count this part of the mesoderm with the hyposoma. Fig. 176. Transverse section of the trunk of a primitive vertebrate (prospondylusj. a aorta, 6 lateral furrow (prorenal duct), rf small intestine,/" floating border of the skin, i muscular cavity (dorsal ccelom-pouch), ms muscles, n renal canals, 11 outer skin, r spinal marrow, s sexual glands (gonades), / corium, -' principal vein, v chorda. The chief and oldest organ of the vertebrate hyposoma, the alimentary canal, is generally described as an unsegmented organ. But we could just as well say that it is the oldest of all the metamerous organs of the vertebrate ; the double row of the ccelom-pouches grows out of the dorsal wall of the gut, on either side of the chorda. In the brief period during which these segmental ccelom-pouches are still openly connected with the gut, they look just like a double chain of metamerous visceral glands. But apart from this, we have originally in all vertebrates an important articulation of the fore-gut, that is wanting in the lower gut, the segmentation of the branchial gut, or " branchiomerism." The gill-clefts, which originally in the older acrania pierced the wall of the fore-gut and the gill-arches that separated them, were presumably also segmental, and distributed among the various metamera of the chain, like the gonades in the after-gut and the nephridia (Fig. 177 ksj. In the amphioxus, too, they are still segmentally formed. Probably there was a division of labour of the hyposomites in the older (and long extinct) acrania, in such wise that those of the fore-gut took the function of breathing and those of the after-gut reproduction. The former developed into gill-pouches, the latter into sex-pouches. There may have been pronephridia in both. Branchiomerism is so much changed in the living vertebrates, and so reduced in the amniotes, that it has been denied altogether by some scientists. Moreover, in the amniotes their respiratory function has disappeared. Nevertheless, certain parts of them have been generally maintained in the embryo by a tenacious heredity. At a very early stage we notice in the embryo of man and the other amniotes, at each side of the head, the remarkable and important structures which we call the gill-arches and -ill-clefts (Plates VIII. -XIII., Figs. 178-1S1/O. Theybelong to the characteristic and inalienable organs of the amnioteembrvo, and are found always in the same spot and with the same arrangement and structure. There are formed to the right and left in the lateral wall of the fore-gut cavity, in its foremost part, first a pair and then several pairs of sac-shaped inlets, that pierce the whole thickness of the lateral wall of the head. They are thus converted into clefts, through which one can penetrate freely from without into the gullet. The wall thickens between these branchial folds, and changes into an arch-like or sickle-shaped piece — the gill, or gullet-arch. In this the muscles and skeletal parts of the branchial gut separate ; a blood-vessel arch arises afterwards on their inner side (Fig. 177 kaj. The number of the branchial arches and the clefts that alternate with them is four or five on each side in the higher vertebrates (Fig. 181 d, /,/',/ )• In some of the fishes (selachii) and in the cyclostoma we find six or seven of them permanently. These remarkable structures had originally the function of respiratory organs — gills. In the fishes the water that serves for breathing and is taken in at the mouth still always passes out by the branchial clefts at the sides of the gullet. In the higher vertebrates they afterwards disappear. The branchial arches are converted partly into the jaws, partly into the bones of the tongue and the car. From the first gill-cleft is formed the tympanic cavity of the ear. (Cf. Plates I., VIII. XIII., first and second row.) The primary articulation of the vertebrate body, which proceeds from the primitive segments of the mesoderm, affects most of its chief systems of organs : in the episoma especially the muscles and skeleton, in the hyposoma the kidneys and embryo, of the third day. Fig, 179 from the front, Fig. 1S0 from the right, n rudimentary nose (olfactory pit), / rudimentary pIG ,g,_ eye (optic pit, lens-cavity), g rudimentary FlG. 181.— Head Of a dog embryo, seen from the front. it the two lateral halves of the foremost cerebral vesicle, b rudimentary eye, c middle cerebral vesicle, de first pair of gill-arches (e upper-jaw process, d lower-jaw process), /■/'■/'' second, third, and fourth pairs of gill-arches, g // //-heart [gright, h left auricle ; i left, k right ventricle I, / origin of the aorta with three pairs of arches, which go to the gill-arches. (From Bischoff. ) the later stages the development of a segmental arrangement o\ the peripheral nerves and blood-vessels ; the one starts from the episoma, the other from the hvposoma. Especially important is the fact that in man and all other vertebrates the psychic organ is subject to this "secondary metamerism." It is readily recognisable in the human embryo in the fourth week, the eetodermic nerve-roots connecting with the corresponding mesodermic muscle-plates of the provertebrae (Fig. iSj). There are few parts of the vertebrate organism that are not subject to metamerism, like the outer covering- or integument oi the body. The outer skin (epidermis ) is unsegmented from the first, and proceeds from the uniformly disposed horny plate. Moreover, the underlying cutis is also not metamerous, although it developes from the segmental structure of the cutis-plates (or lateral lamina? of the episomites, Figs. 1 68, 169 cp). The vertebrates are strikingly and profoundly different from the articulates in these respects also. Further, most of the vertebrates still have a number of unarticulated or monomeric organs, which have arisen loeallv, by adaptation of particular parts of the body to certain special functions. Of this character are the sense-organs in the episoma, and the limbs, the heart, the spleen, and the large visceral glands — lungs, liver, pancreas, etc. — in the hvposoma. The heart is originally only a local spindle-shaped enlargement of the large ventral blood-vessel or principal vein, at the point where the subintestinal passes into the branchial artery, at the limit oi the head and trunk (figs. iSt, [82). The three higher sense-organs — nose, eye, and ear — were originally developed in the same form in all the craniotes, as three pairs of small depressions in the skin at the side of the head. The organ of smell, the nose, has the appearance of a pair of small pits above the mouth-aperture, in front of the head (Fig. 180 //)• The organ oi sight, the eye, is found at the side of the head, also in the shape of a depression (Figs. 180 /, 1S1 b), to which corresponds a considerable vesicular hollowing of the foremost cerebral vesicle on each side. Farther behind, at each side of the head, there is a third depression, the first trace of the organ of hearing (Fig. iSog-). six mm. long-, magnified twenty times. (From Moll.) The rudiments' of the cerebral nerves and the roots of the spinal nerves are especially marked. Underneath the four gill-arches (left side) is the heart (with auricle, I", and ventricle, A"), under this again the liver ( L). development, it can still .scarcely be distinguished from that o( any other higher vertebrate (c\. Plate 1. and p. 356). All the chief parts o( the body are now laid down : the head with the primitive skull, the rudiments of the three higher Sense-organs and the live cerebral vesicles, and the ^illarches and clefts ; the trunk with the spinal cord, the rudiment of the vertebral column, the chain of metamera, the heart and chief blood-vessels, and there is no indication whatever of the "extremities" at this stage; they are formed later on. Here again we have a fact of the utmost interest. It proves that the older vertebrates had no feet, as we find to-day in the lowest living vertebrates (amphioxus and the cvclostoma). The descendants of these ancient footless vertebrates only acquired extremities — two fore-legs and two hind-legs — at a much later i"ic;. 183. Transverse section of the shoulder and fore-limb (wing) of a chickembryo of the fourth day, magnified about twenty times. Beside the medullary tube we ran seeon each side three clear streaks in the dark dorsal wall, which advance into the rudimentary fore-limb or wing 1 1 1. The uppermost of them is the muscular plate; tin- middle is the hind and the lowest On- lor,' rool of a spinal nerve. Under the chorda in the middle is 1 ho single aorta, and at each side o( ii a cardinal vein, and below these the primitive kidneys. The gut is almost closed, ventral wall advances into the amnion, encloses the embryo. (From Remai.) stage of development. These were at first all alike, though they afterwards vary considerably in structure — becoming fins (of breast and belly) in the fishes, wings and legs in the birds, fore and hind legs in the creeping animals, arms and legs in the apes and man. All these parts develop from the same simple original structure, which forms secondarily from the trunk-wall (Figs. 183, 184). They have always the appearance of two pairs of small How the five fingers or toes with their blood-vessels gradually differentiate within the simple fin-like structure of the limbs can be seen in the instance of the lizard in Fig. 185. They are formed in just the same way in man ; in the human embryo of five weeks the five fingers can clearly be distinguished within the fin-plate (Fig. 186). region and hind legs of a chick-embryo of the fourth day, magnified about forty times, h horn-plate, •hj medullary tube, n Canal of the tube, u primitive kidneys, x chorda, e hind legs, b allantois canal in the ventral wall, / aorta, v cardinal veins, a gut, d gutgland layer, /'gut fibre layer, ^embryonic epithelium, r dorsal muscles, c body-cavity or cceloma. (From Waldeyer. ) very instructive, and reveals more mysteries to the impartial student than all the religions in the world put together. For instance, let us compare attentively the three successive Stages of development that are represented, in twenty Fig. 185. Development of the lizard's legs (lacerta agUis), with special relation 10 their blood-vessels. r, j, 5, 7, 9, // right fore-leg; /,;. /■; left fore-leg ; -'. -/. '', 8, m, u right hind-leg ; 14, 16 left hind-leg ; SS I ' lateral veins of the trunk, VU umbilical vein. (From /•'. ffochstetter.) different amniotes, in the six following Plates (VIII. -XI II.). When we see that as a fact twenty different amniotes of such divergent characters develop from the same embryonic form, we can easily understand that they may all descend from a common ancestor. In the first stage of development (the first row, I.), in which the head with the five cerebral vesicles is already clearly indicated, but there are no limbs, the embryos of all the vertebrates, from the fish to man, are only incidentally or not at all different from each other. In the second stage (the Fig. i86. — Human embryo, five weeks old, eleven mm. long-, seen from the right, magnified ten times. ( From Russel Bardeen and Harmon Lewis. ) In the undissected head we see the eye, mouth, and ear. In the trunk the skin and part of the muscles have been removed, so that the cartilaginous vertebral column is free ; the dorsal root of a spinal nerve goes out from eaeli vertebra (towards the skin of the back). In the middle of the lower half of the figure part of the ribs and intercostal muscles are visible. The skin and muscles have also been icmoved from the right limbs; the internal rudiments of the ft\o Fingers of the hand, and five toes of the foot, are clearly seen within the finshaped plate, and also the strong network of nerves that goes from the spinal cord to the extremities. The tail projects under the foot, and to the right of it is the first part of the umbilical cord. middle row, II.). which shows the limbs, we begin to see differences between the embryos of the lower and higher vertebrates ; but the human embryo is still hardly distinguishable from that of the higher mammals. In the third Stage (lowest row, III.), in which the gill-arches have I'u.-. 187 <). Embryos of the bat (,vespertilio murinus) at three different stages. (From Oscar Schultze.) Fit;. 1S7. Rudimentary limbs if fore-leg, // hind-leg). I lenticular depression, r olfactory pit, nk upper jaw, nk lower jaw, k... £„, k- , first, second, and third gill-arches, » amnion, >i umbilical vessel, </ yelk-sac. Fig. iSS. Rudiment of flying membrane, membranous told between ion' and hind leg. " umbilical vessel, 0 ear-opening, /"flying membrane. Fig. 189. The flying membrane developed ami stretched aero— the fingers of the hands, which cover the face. 1 Because they show how the most diverse structures may be developed from a common form. As we actually see this in tin' case of the embryos, we have a righl to assume it of the stem-forms. Nevertheless, this resemblance, assume in virtue of the laws of heredity, several important phylogenetic conclusions follow at once from these ontogenetic facts. The profound and remarkable similarity in the embryonic development of man and the other vertebrates can only be explained when we admit their descent from a common ancestor. As a fact, this common descent is now accepted by all competent scientists ; they have substituted the natural evolution for the supernatural creation of organisms. different orders. The six plates VIII. -XIII. show the more or less significant similarity that exists, in respect of most important structural features, between the human embryo and the embryo of the higher vertebrates (amniotes) in the earlier periods of development. The similarity is closer the earlier the stage of development at which we compare them. It persists the longer the closer is the stem-relation between the various animals, in harmony with the "law of the ontogenetic connection of related forms" (see following Chapter). l'latos XI., XII., and XIII. show the embryos of eleven different mammals of the three corresponding stages. The conditions of tin' three different stages! represented by the three rows (I., II., III.), are chosen so as to correspond as closely as possible. The first nop) row, I., represents an early stage, with gill-clefts, without leys. The second (middle) row, II., shows a somewhat later stage, with the first traces o\' the leys, still with gill-clefts. The third (bottom) row represents a -.till later stage, with more advanced leys, after the disappearance of the gill-clefts. The envelopes and appendages ol the embryo (amnion, yelk-sac, allantois) are omitted. The whole of the sixty figures are slightly magnified, the lower ones less than the upper. They have been almost reduced to a common size for the purpose of comparison. All the embryos are looked al from the left : the head-end is upward, the tail-end below, the curved back turned to the ritfht. The letters have the same meaning in all the sixty figures : :• Fore-brain, j intermediate-brain, in middle-brain, /; hind-brain, n afterbrain, r spinal cord, e nose, a eye, " ear, k gill-arches, ,- heart, m vertebral column, /'fore ley, b hind ley, s tail. ventral vessel of the vermalia. 6. Gut with gill-chamber (headgut converted into a gill-pannierj with gill-clefts and hypobranchial blast. 9- Body-cavities (right and left) early divided by a frontal Septum into a dorsal myocoel and a ventral gonocoel (episomites and 4. Nervous centre ventral, originally articulated (ventral marrow). (Doublechain of ventral ganglia. ) 6. Gut without gill-chamber 1 headgut never with gill-clefts ; hypobranchial groove wanting in all the articulates). without frontal septum : hence no division into dorsal episomites and ventral hyposomites ; no antithesis of dorsal and ventral body. FCETAL MEMBRANES AND CIRCULATION1 Tin- mammal-organisation of man. Man has the same structure a?, all the other mammals, and his embryo developes in the same way as that of the higher vertebrates. The law of the ontogenetic connection of related forms. Application of it to man. Shape and sizo of the human embryo in the firsl lour weeks. The human embryo is almost completely like thai of other mammals in structure in the first month. In tin- second month certain notable differences begin to appear. Tinappendages and envelopes of the human embryo. Yelk-sac or umbilical vesicle. AJUantois or urinary sac. Placenta. Ventral pedicle and peculiar placentation of man and the anthropoid apes. Amnion and serok-mma (serous membranes). Exoccelom. The heart, the first blood-vessels, and the blood are formed from the gut-fibre layer. Vascular layer and mesencyhma. The heart separates from the wall of the fore-gut Double structure of the ln-art in the amniotes cenogenetic. Tin- first embryonic circulation in the germinative area : vitelline arteries and veins. The second embryonic circulation in the allantois : umbilical arteries and veins. Sections of human embryology. Among the many interesting phenomena that we have encountered in the course of human embryology, there is an especial importance in the fact that the development of the human body follows from the beginning just the same lines as that of the other viviparous mammals. As a fact, all the embryonic peculiarities that distinguish the mammals from other animals are found also in man ; even the ovum with its distinctive membrane (zona pelhtcida, Fig. 14) shows the same typical structure in all mammals (apart from the older oviparous monotremes). It has long since been deduced from the structure of the developed man that his natural place in the animal kingdom is among the mammals. Linne (1735) placed him in this class with the apes, in one and the same order (primates ), in his Systema natures. This position is fully confirmed by comparative embryology. We ' Cf. Sir \V. Turner: "Some general observations on tin- placenta, with especial reference to the theory of evolution, "Journal of Aunt, and Physiol. 11S771: and " On the placentation of the apes, with a comparison with that of tin- human female," /'////".v. Trans., 1878, vcL 169. see that man entirely resembles the higher mammals, and most of all the apes, in embryonic development as well as in anatomic structure. And if we seek to understand this ontogenetic agreement, in the light of the biogenetic law, we find that it proves clearly and necessarily the descent of man from a series of other mammals, and proximately from the primates. The common origin of man and the other mammals from a single ancient stem-form can no longer be questioned ; nor can the immediate blood-relationship of man and the ape. The essential agreement in the whole bodily form and inner structure is still visible in the embryo of man and the other mammals at the late stage of development at which the mammal-body can be recognised as such. (Cf. Plates VIII. -XIII., second row.) But at a somewhat earlier stage, in which the limbs, gill-arches, sense-organs, etc., are already outlined, we cannot yet recognise the mammal embryos as such, or distinguish them from those of birds and reptiles (Plates VIII. -XIII., top row). When we consider still earlier stages of development, we are unable to discover any essential difference in bodily structure between the embryos of these higher vertebrates and those of the lower, the amphibia and fishes. If, in fine, we go back to the construction of the body out of the four germinal layers, we are astonished to perceive that these four layers are the same in all vertebrates, and everywhere take a similar part in the building-up of the fundamental organs of the body. If we inquire as to the origin of these four secondary layers, we learn that they always arise in the same way from the two primary layers ; and the latter have the same significance in all the metazoa (i.e., all animals except the unicellulars). Finally, we see that the cells which make up the primary germinal layers owe their origin in every case to the repeated cleavage of a single simple cell, the stem-cell or fecundated ovum. It is impossible to lay too much stress on this remarkable agreement in the chief embryonic features in man and the other animals. We shall make use of it later on for our first rudiments of the principal parts o\ the body, especially the oldest organ, the alimentary canal, are the same everywhere ; they have always the same extremely simple form. All the peculiarities that distinguish the various groups of animals from each other only appear gradually in the course of embryonic development ; and the closer the relation of the various groups, the later they are found. We may formulate this phenomenon in a definite law, which may in a sense be regarded as an appendix to our biogenetic law. This is the law of the ontogenetic connection of related animal forms. It runs: The closer the relation of two fully-developed animals in respect of their whole bodily structure, and the nearer they are connected in the classification of the animal kingdom, the longer does their embryonic form retain its identity, and the longer it is impossible (or only possible on the ground of subordinate features) to distinguish between their embryos. This law applies to all animals whose embryonic development is, in the main, an hereditary summary of their ancestral history, or in which the original form of development has been faithfully preserved by heredity. When, on the other hand, it has been altered by cenogenesis, or disturbance of development, we find a limitation of the law, which increases in proportion to the introduction of new features by adaptation (cf. Chapter I., pp. 8-10). Thus the apparent exceptions to the law can always be traced to cenogenesis. When we apply to man this law of the ontogenetic connection of related forms, and run rapidly over the earliest stages of human development with an eye to it, we notice first of all the morphological identity of the ovum in man and the other mammals at the very beginning (Figs. 1, 14). The human ovum possesses all the distinctive features of the ovum of the viviparous mammals, especially the characteristic formation of its membrane (zona pellucida), which clearly distinguishes it from the ovum of all other animals. When the human foetus has attained the age of fourteen days, it formsa globular vesicle (or " embryonic vesicle ") of about four groove millimetres in diameter. A thicker part of its border forms a simple sole-shaped embryonic shield two millimetres long (Fig. 199). On its dorsal side we find in the middle line the straight medullary furrow, bordered by the two parallel dorsal or medullary swellings (in J. Behind, it passes by the neurenteric canal into the primitive gut or primitive groove. From this the invagination of the two ccelom-pouches proceeds in the same way as in the other mammals the human embryo has doubled its length ; it is now about five millimetres long, and, when seen from the side, shows the characteristic bend of the back, the swelling of the head-end, the first outline of the three higher sense-organs, and the rudiments of the gill-clefts, which pierce the sides of the neck (Fig. 191, III.; Plate XIII., Fig. MI). The allantois has grown out of the gut behind. The embryo is already entirely enclosed in the amnion, and is only connected in the middle of the belly by the vitelline duct with the embryonic vesicle, limbs at this stage, no trace o( arms or legs. The head-end has been strongly differentiated from the tail-end ; and the first outlines of the cerebral vesicles in front, and the heart below, under the fore-arm, are already more or less clearly seen. There is as vet no real face. Moreover, we seek in vain at this stage a special character that may distinguish the Fig. i. ii. Human embryos from t'.ie second to the fifteenth week, natural size, seen from the left, the curved back turned towards the right. (Mostlj from Ecker.) II. of fourteen days. III. of three weeks. IV. of Four weeks. V. of five weeks. VI. of six weeks. VII. of seven weeks. VIII. 01 eight weeks. XII. of twelve weeks. XV. of fifteen weeks. A week later (after the fourth week, on the twenty-eighth to thirtieth day of development) the human embryo has reached a length of four to five lines, or about a centimetre (Fig. i()i, IV. ; Plate XIII., Fig. Mil). We can now clearly distinguish the head with its various parts ; inside it long (taken from the womb of a suicide eight hours after death). (From Rabl.) a nasal pits, ,: eve, u lower jaw, z arch of bone of tongue, k.. and kt third and fourth gill-arch, h heart, s primitive segments, vg fore-limb (arm), hg hind-limb (leg), between the two the ventral pedicle. head the gill-arches, which divide the gill-clefts; at the sides o( the head the rudiments of the eyes, a couple of pits in the outer skin, with a pair o( corresponding simple vesicles growing out of the lateral wall of the fore-brain (Figs. 192, [93 a). Far behind the eyes, over the last gill-arches, we see the vesicular rudiment of the auscultory organ. The rudimentary limbs are now clearly outlined — four simple buds of the shape oi round plates, a pair of fore ( Vg) and a pair of hind legs f/lffj, the former a little larger than the latter. The large head bends over the trunk, almost at a right angle. The latter is still connected in the middle of its ventral side with the embryonic vesicle ; but the embryo has still further severed itself from it, so that it already hangs out as the yelk-sac. The hind part of the body is also very much curved, so that the pointed tail-end is directed towards the head. The head and face-part are sunk entirely on the still open breast. The bend soon increases so much that the tail almost touches the forehead (Fig. 191, V. ; Fig. 193). We may then distinguish three or four special curves on the round dorsal surface — namely, a skull-curve in the region of the second cerebral vesicle, a neck-curve at the beginning of the spinal cord, and a tail-curve at the fore-end. This pronounced curve is only shared by man and the higher classes of vertebrates (the amniotes) ; it is much slighter, or uot found at all, in the lower vertebrates. At this age (four weeks) man has a considerable tail, twice as long as his legs. A vertical longitudinal section through the middle plane of this tail (Fig. 194) shows that the hinder end of the spinal marrow extends to the point of the tail, as also does the underlying chorda ( cli J, the terminal continuation of the vertebral column. Of the latter, the rudiments of the seven coccygeal vertebra' are visible — thirty-two indicates the third and thirtysix the seventh of these. Under the vertebral column we see the hindmost ends of the two large blood-vessels of the tail, the principal artery (aorta caudalis or arteria sacra/is media, AoJ,and the principal vein (vena caudalis or sacral is media ). Underneath is the opening of the anus (an) and the urogenital sinus (S.ug). From this anatomic structure of the human tail it is perfectly clear that it is the rudiment of an ape-tail, the last hereditary relic of a long hairy tail, which has been handed down from our tertiary primate ancestors to the present day. vein, mi anus, S. ug semis urogenitalis. Surgeon-General Bernhard Ornstein, of Greece, these tailed men are not uncommon ; it is not impossible that they gave rise to the ancient fables of the satyrs. A great number of such cases are given by Max Bartels in his essay on " Tailed Men" (1884, in the Archiv jiir Anthropologic, Band XV.), and critically examined. These atavistic human tails are often mobile ; sometimes they contain only muscles and fat, sometimes also rudiments o( caudal vertebrae. They aitain a length of jo 25 cm. and more. Granville Harrison has very carefully studied one oi these eases o\ "pig-tail," which he removed by operation from a six months' old child in 1901. The tail moved briskly when the child cried or was excited, and was drawn up when at rest (Fig". u>5 A-C). (especially in south-eastern Asia and the archipelago), so that we might speak of a special race or "species" of tailed men (homo Cauda tus). Battels has " no doubt that these tailed men will be discovered in the advance of our geographical and ethnographical knowledge o( the lands in question " {A rchvof&r A nthropologiey Band XV., p. 129). for the most part cut off from the embryonic vesicle. But the mouth-cavity is not yet separated from the nasal cavity, and the face not yet shaped. The heart shows all its four sections ; it is very large, and almost fills the whole of the pectoral cavity (Fig. 196 ov). Human em- aorta-arches, c, <"', c" vena cava, ae lungs (y pulmonary artery ), e stomach, m primitive kidneys (./left vitelline vein, s cystic vein, a right vitelline artery, >i umbilical artery, u umbilical vein), X vitelline duct, i rectum, S tail, □ fore-leg, 9' hind-leg. The liver is removed. (From Cosh:) lungs. The primitive kidneys (m ) are very large ; they fill the greater part of the abdominal cavity, and extend from the liver ( f) to the pelvic gut. Thus at the end of the first month all the chief organs are already outlined. But there are at this stage no features bv which the human embryo materially differs from that oi the dog, the hare, the ox, or the horse — in a word, oi any other higher mammal. All these embryos have the same, or at least a very similar, form ; they can at the most be distinguished from the human embryo by the total size of the body or some other insignificant difference in si/e. Thus, for instance, in man the head is larger in proportion to the trunk than in the ox. The tail is rather longer in the dog than in man. These are all negligible differences. On the other hand, the whole internal organisation and the form and arrangement of the various organs are essentially the same in the human embryo of four weeks as in the embryos of the other mammals at corresponding stages. It is otherwise in the second month of human development. Fig. 1 l> 1 represents a human embryo of six weeks (VI.), one of seven weeks (VII.), and one of eight weeks (VI 1 1.) at natural size. The differences which mark oi'\ the human embryo from that of the dog and the lower mammals now begin to be more pronounced. We can see important difference;, at the sixth, and still more at the eighth, week, especially in the formation of the head (Plate XIII., Fig. Mill, etc.). The size of the various sections of the brain is greater in man, and the tail is shorter. Other differences between man and the lower mammals are found in the relative si/e of the internal organs. But even at this stage the human embryo differs very little from that of the nearest related mammals, the apes, especially the anthropomorphic apes. The features by means of which we distinguish between them are not clear until later on. Even at a much more advanced stage of development, when we can distinguish the human foetus from that o( the ungulates at a glance, it still closely resembles that of the higher apes. At last we get the distinctive features, and we can distinguish the human embryo confidently at the first glance from that of all other mammals during the last four months of foetal life — from the sixtli to the ninth month of pregnancy. Then we begin to find also the differences between the various races of men, especially in regard to the formation of the skull and the face. (Cf. Chapter XXIII.) The striking resemblance that persists so long between the embryo of man and of the higher apes disappears much earlier in the lower apes. It naturally remains longest in the large anthropomorphic apes (gorilla, chimpanzee, orang, and gibbon). The physiognomic similarity of these animals, which we find so great in their earlier years, lessens with the increase of age. On the other hand, it remains throughout life in the remarkable long-nosed ape of Borneo (nasalis lai~vatus, Plate XXV.). Its finely-shaped nose would be regarded with envy by many a man who has too little of that organ. ■ If we compare the face of the long-nosed ape with that of abnormally ape-like human beings (such as the famous Miss Julia Pastrana, Fig. 198), it will be admitted to represent a higher stage of development. There are still people among us who look especially to the face for the "image of God in man." The long-nosed ape would have more claim to this than some of the stumpynosed human individuals one meets. we shall consider presently; it surrounds the foetus and its appendages as a broad, completely-closed sac ; the space between the two, tilled with clear watery fluid, is the scroccelom, or interamniotic cavity ("extra-embryonic bodycavity"). But the smooth surface of the sac is quickly covered with numbers o\ tiny tufts, which are reallv hollow out-growths like the fingers of a glove (Figs. 199, 204, 217 (//:). They ramify and push into the correspondingdepressions that are formed by the tubular glands of the mucous membrane o( the maternal womb. Thus, the ovum secures its permanent seat (Figs. 199-207). In human ova of eight to twelve days this external membrane, the chorion, is already covered with small tufts or villi, and forms a ball or spheroid of six to eight millimetres in diameter (Figs. 199-201). As a large quantity of fluid gathers inside it, the chorion expands more and more, so that the embryo only occupies a small part of the space within the vesicle. The villi of the chorion grow larger and more numerous. They branch out more and more. At first the villi cover the whole surface, but they afterwards disappear from the greater part of it ; they then develop with proportionately greater vigour at a spot where the placenta is formed from the allantois. When we open the chorion of a human embrvo of three weeks, we find on the ventral side of the foetus a large round sac, filled with fluid. This is the yelk-sac, or "umbilical vesicle," the origin of which we have considered previously. The larger the embrvo becomes the smaller we find the yelk-sac. Afterwards we find the remainder of it in the shape of a small pear-shaped vesicle, fastened to a long thin stalk (or pedicle), and hanging from the open belly of the foetus (Fig. 207). This pedicle is the vitelline duct, and is separated from the body at the closing of the navel. The wall of the umbilical vesicle consists, you will remember, of an inner plate, the gut-gland layer and an outer plate, the gut-fibre layer. It is therefore made up of the same constituents as the gut-wall itself, and really forms a direct continuation of it. In birdsand reptiles, in which the yelk-sac is much larger, it contains a considerable quantity of nutritive material, albuminous and fatty substances. Fig. 199.— Human OVUm of twelve to thirteen days (?). (From Allen Thomson.) 1. Not opened, natural size. 2. Opened and magnified. Within the outer chorion the tiny curved foetus lies on the large embryonic vesicle, to the left above. Fig. 201. — Human foetUS of ten days, taken from the preceding ovum, magnified ten times, a yelk-sac, b neck (the medullary groove already closed), c head (with open medullary groove), d hind part (with open medullary groove), e a shred of the amnion. Fig. 202.— Human OVUm of twenty to twenty-two days. (From Allen Thomson.) Natural size, opened. The chorion forms a spacious vesicle, to the inner wall of which the small fetus (to the right above) is attached by a short umbilical cord. Fig. 203.— Human foetUS of twenty to twenty-two days, taken from the preceding ovum, magnified, a amnion, b yelk-sac, c lower-jaw process of the first gill-arch, d upper-jaw process of same, e second gill-arch (two smaller ones behind). Three gill-clefts are clearly seen, /'rudimentary fore-leg, P" auditory vesicle, /; eye, i heart. These pass by the vitelline duct into the visceral cavity, and serve as food, as in the oviparous monotremes. In the other (viviparous) mammals the yelk-sac is much less important stage. Fig. 204.— Human embryo of sixteen to eighteen days. (From Coste. ) Magnified. The embryo is surrounded by the amnion ( » ), lies Free with this in tin- opened embryonic vesicle. The belly is drawn up by the large yelk-sac ( (I ), and fastened to the inner wall of the embryonic membrane by the short and thick pedicle (b). Hence the normal convex curve of the back (Fig. 20.^) is here changed into an abnormal concave surface. // heart, hi parietal mesoderm. The spots on the outer «.ill ol the serolemma are the roots of the branching chorion-villi, which are free at the border. Behind the yelk-sac a second appendage, of much greater importance, is formed at an early stage at the belly oi the mammal embryo. This is the allantois or" primitive u ni nary sac," an important embryonic organ, only found in the three higher classes of vertebrates. In all the amniotes the allantois quickly appears at the hinder end of the alimentary canal, growing out of the cavity of the pelvic gut (Fig. 208, ;-, //, Fig. 209 ALC '). Fig. 207. -Human embryo with its membranes, six weeks old. Tinouter- envelope of the whole ovum is ilu- chorion, thickly covered with its branching villi, a product of the serous membrane. The embryo is enclosed in the delicate amnion-sac. The yelk-sac is reduced to a small pear-shaped umbilical vesicle; its thin pedicle, the long vitelline duet, is enclosed in the umbilical cord. In the latter, behind the vitelline duet, is the much shorter pedicle of the allantois, the inner lamina of which (the gut-eland layer) forms a large vesicle in most of the mammals, while the outer lamina is attached to the inner wall of the outer embryonic coat, and forms the placenta there. (Half diaerrammatii Fig. jos.— Median longitudinal section of the embryo ofa chick (fifth day of incubation}, seen from the right (head to the right, tail to the left). Dorsal body (episoma) dark, with convex surface, d gut, 0 mouth, a anus, A lamina of the wall is formed of the thickened gut-fibre layer. The little vesicle gets bigger and bigger, and grows into a large sac, filled with fluid, in the wall of which large bloodvessels are formed. It soon reaches the inner wall of the foetal cavity, and spreads along the inner surface of the chorion (Fig. 209 ALC). In many mammals the allantois is so large that at last it surrounds the whole embryo and the other appendages as a wide membrane, and spreads over the whole of the inner surface of the prochorion. When we open (fcetal membranes and appendages). (From Turner.) E, J/, H, outer, middle, and inner germ layer of the embryonic shield, which is figured in median longitudinal section, seen from the left, am amnion, AC amniotic cavity, UV yelk-sac or umbilical vesicle, ALC allantois, al periccelom or serocoelom (interamniotic cavity), ss serolemma (or serous membrane), pc prochorion (with villi). an ovum of this character, we encounter first a large cavity filled with fluid ; this is the amniotic cavity. Only when this membrane is removed do we reach the amniotic vesicle which encloses the embryo proper. The further development of the allantois varies considerably in the three sub-classes of the mammals. The two lower sub-classes, monotremes and marsupials, retain the simpler structure of their ancestors, the reptiles. The wall of the allantois and the enveloping serolemma remains smooth and without villi, as in the birds. But in the third subclass of the mammals the serolemma forms, by invagination at its outer surface, a number of hollow tufts or villi, from which it takes the name of the chorion or mallochorion. The gut-fibre layer o( the allantois, richly supplied with branches of the umbilical vessel, presses into these serous villi of the primary chorion, and forms the "secondary chorion." lis embryonic blood-vessels are closely correlated to the contiguous maternal blood-vessels of the environing uterus, Fig. 210.— Embryo of a dog, from the right. ,; first, /> second, <• third, d fourth cerebral vesicle, e eye,fi auditory vesicle, ,j,r// first gill-arch (g lower jaw, // upper jaw), i second gill-arch, klm heart { I- right auricle, / right and m left ventricle), >i origin of aorta, « heart-pouch, /> liver, </ nut, r vitelline duet, s yelk sae (torn away), / allantois (broken off), u amnion, ;■ tore-ley, x hind-leg. ( From Bischoff. ) embrvo which we call the placenta. The pedicle of the allantois, which connects the embryo with the placenta and conducts the strong umbilical vessels from the former to the latter, is covered by the amnion, and, with this amniotic sheath and the pedicle of the yelk-sac, forms what is called the umbilical cord (Fig. 212 al). As the large and blood-filled vascular network of the fcetal allantois attaches itself closelv to the mucous lining of the maternal womb, and the partition between the blood-vessels of mother and child becomes much thinner, we get that remarkable nutritive apparatus of the foetal body which is characteristic of the placentalia (or choriata). We shall return afterwards to the closer consideration of this (cf. Chapter XXIII.). many modifications, and these are in part of great phylogenetic Fig. 21 i.— Dog-embryo, twenty-five days old, from the ventral side, opened (as Figs. 196 and 197). Pectoral and abdominal walls are removed. a nose-pits, b eyes, c lower jaw (first gill-arch), d second gill-arch, efgh heart (c right, /'lett auricle ; .if right, /; left ventricle), /aorta (origin), kk liver (in the middle between the folds the umbilical vein cut through), / stomach, m gut, n yelk-sac, o primitive kidneys, /> allantois, q fore-leg, r hind-leg. The curved embryo lias been straightened out. (From Bisrhoff.) importance and useful in classification. There is only one of these that need be specially mentioned — the important fact established by Selenka in 1890 that the distinctive human placentation is confined to the anthropoids. In this most advanced group of the mammals the allantois is very small, soon loses its cavity, and then, in common with the amnion, undergoes certain peculiar changes. The umbilical cord developes in this case from what is called the "ventral pedicle." Until very recently this was regarded as a structure peculiar to man. We now know from Selenka that the muchdiscussed ventral pedicle is merely the pedicle of the allantois, combined with the pedicle o\ the amnion and the rudimentary pedicle oi the yelk-sac. It has just the same structure in the orang and gibbon (Figs. 213-216), and very probable in the chimpanzee and gorilla, as in man ; it is, therefore, not a disproof, but a striking fresh proof, o( the blood-relationship of man and the anthropoid apes. cause the placenta developes from the allantois only in the placentals, or the higher mammals and man, and not in the lower mammals (marsupials and monotremes) ; thirdly, because the remarkable peculiarities of human placentation are only found outside man in the anthropoid apes, not in the other placentals. We find only in the anthropoid apes — the gibbon and orang of Asia and the chimpanzee and gorilla of Africa the peculiar and elaborate formation of the placenta that characterises man (Fig. 217). In this case there is at an early Fie.. 212. Diagrammatic frontal section of the pregnant human womb. ( From Longet. 1 The embryo hang? by the umbilical cord, which encloses the pedicle of the allantois ( al ' ). nb umbilical vessel, am amnion, ch chorion, ds decidua serotina, </;• decidua vera, dr decidua reflexa, > villi of the placenta, c cervix uteri, u uterus. concolorj. Fig". 213 embryo of seventeen mm. from head to buttocks, magnified four times ; seen from the left. Fig-. 214 the same, seen from the front. Fig-. 215 embryo of one hundred mm. from head to buttocks, three-fourths natural size, in the same position as found in uterus, with which it is still connected by the umbilical cord. Only the dorsal half of the dissected uterus is shown, and the placenta is attached to the central part of this. stage an intimate blending of the chorion of the embryo and the part o( the mucous lining o( the womb to which it attaches. The villi o( the chorion with the blood-vessels they contain grows so completely into the tissue of the uterus, which is rich in blood, that it becomes impossible to separate them, and they form together a sort of cake. This comes away as the "after-birth " at parturition ; at the same time the part o( the mucous lining of the uterus that has united inseparably with the chorion is torn away ; hence it is Fig. ji6.— Male embryo of the Siamang-gibbon (hyhbates siamanga) of Sumatra, two-thirds natural size: to the left the dissected uterus, of which only the dorsal half is given. The embryo has been taken out, and the limbs folded together; it is still connected by the umbilical cord with the centre of the circular placenta, which is attached to the inside of the womb. Both this embryo and the preceding (Fig. 215) take the head-position in the womb, and ibis is normal in man also. called the decidua (" falling-away membrane"), and also the " sieve-membrane," because it is perforated like a sieve. We find a decidua of this kind in most of the higher placentals ; but it is only in man and the anthropoid apes that it divides into three parts — the outer, inner, and placental decidua. The external or true decidua (Fig. 212 tin. Fig. 218^) is the part o\ the mucous lining of the womb that clothes the inner surface o\ the uterine cavity wherever it is not connected with the placenta. The placental or spongy decidua ( placcntalis or serotina, Fig. 212 ds, Fig. 218 d ) is really the placenta itself, or the maternal part of it (placenta uterina ) — namely, that part of the mucous lining of the womb which unites intimately with the chorion-villi of the foetal placenta. The internal or false decidua (interna or reflexa, Fig. 212 dr, Fig. 218 f) is that part of the mucous lining of the womb which encloses the remaining: surface of the ovum, the smooth chorion (chorion Iceve), in the shape of a special thin membrane. The origin of these three different deciduous membranes, in regard to which quite erroneous views (still retained in their names) formerly prevailed, is now quite clear; the external decidua vera is the specially modified and subsequently detachable superficial stratum of the original mucous lining of the womb. The placental decidua serotina is that part of the preceding which is completely transformed by the ingrowth o( the chorion-villi, and is used for constructing the placenta. The inner decidua reflexa is formed by the rise of a circular fold of the mucous lining (at the border of the decidua vera and serotina), which grows over the foetus (like the amnion) to the end. Fig. 218.— Human foetus, twelve weeks old, with its membranes, natural size. The umbilical cord goes from its navel to tin- placenta, b amnion, ^chorion, d placenta] d' relics or \illi on smooth chorion] /' internal or reflex deciduat g external or true decidua. (From B. Schultze. ) The peculiar anatomic features that characterise the human foetal membranes are found in just the same way in the higher apes. The lower apes and the other discoplacentals show more or less considerable variations, and, in general, simpler features. This applies especially to the delicate structure of the placenta itself, the blending of the chorion-villi with the decidua serotina. The mature human placenta is a circular (less frequently oval) disk of a soft, spongy texture, six to eight inches in diameter, aboui cue inch thick, and one to one and a half pounds in weight. Its convex outer surface (uniting with the uterus) is very uneven and tufted. Its concave inner surface (facing the uterine cavity) is quite smooth, and covered by the amnion. As a rule, the umbilical cord (funiculus umbilicalis ) starts from about the middle of the placenta; we have considered the origin of this from the ventral pedicle. This also is covered or sheathed by the amnion, which passes directly into the abdominal skin at the navel end of the cord (Fig. 218). The mature umbilical cord is a cylindrical string, twisted spirally Fig. 219.— Mature human foetus (at the end ot pregnancy, in its natural position, taken out of the uterine cavity). On the inner surface of the latter (to the left) is the placenta, which is connected by the umbilical cord with the child's navel. (From Bernhard Schultze.) on its axis, generally about twenty inches long and half an inch thick. It consists of a gelatinous connective tissue (the " Whartonian jelly "), in which we find the remainder of the vitelline vessels and the large umbilical vessels — the two umbilical arteries which conduct the blood of the embryo to the placenta and the strong umbilical vein that conveys the blood from the latter to the heart. The countless fine branchlets of this foetal umbilical vessel enter the ramified chorion-villi of the foetal placenta, and finally join in a peculiar way with these to form the wide blood-filled cavities that expand in the uterine placenta and contain the maternal blood. The very complicated and difficult anatomic relations that develop here between the foetal and maternal placenta are found in this form only in man and the anthropoid ape; they differ more or less considerably in all the other deciduates. The umbilical cord is also proportionately longer in man and the apes than in the other mammals. Bladder Fig. j.'o. Median section of the lower half of the trunk of a woman in advanced pregnancy. The head of the child is already in the pelvis in, ili.- normal head-position. The foetal vesicle (the size of an apple) is siill whole in (In- vagina : the foetal water lias not yel escaped. 1 From Braune.) Until recently it was thought that the human embryo was distinguished by its peculiar construction of a solid allantois and a special ventral pedicle, and that the umbilical cord developed from this in a different way from in the other mammals. The opponents of the unwelcome " ape-theory " laid great stress on this, and thought they had at last discovered an important indication that separated man from all the other placentals. But the remarkable discoveries published by the distinguished zoologist Selenka in 1890 proved that man shares these peculiarities of placentation with the anthropoid apes, though they are not found in the other apes. Thus the very feature which was advanced by our critics as a disproof became a most important piece of evidence in favour of our pithecoid origin. The new facts that Selenka discovered during his investigation of this question in India are so important, and yield such far-reaching conclusions, that I will give the results in his own words : — Some embryonic organs are developed earlier and some later in the apes and man than in the other mammals. Among the anticipated structures are: ( 1) the innumerable chorion-villi, (2) the coelom-sacs, by the expansion of which the yelk-sac is early removed and the amnion closed, and (3) the pedicle of the allantois. It is true that it quickly separates from the wall of the embryonic vesicle, but its vascular network only developes later on. As it has completely lost its earlier function of respiratory and nutritive organ, it must be regarded as a rudimentary organ. It sends no vessels into the chorion, all the bloodvessels of which are exclusively allantoic. (2) The rise of the allantoic cavity also is delayed, and (3) the differentiation of the germinative area. As special structures we may designate: (1) the looser texture of the somatopleura, which lines the chorion ; (2) the persistence of the pedicle of the allantois ; (3) the expansion of the amnion and its blending with the chorion ; (4) the formation of two placenta; side by side, one of which may remain rudimentary; (5) the degeneration of the yelk-sac into a rudimentary organ ; and (6) the attachment of the non-placental part of the foetal membrane — whether it be the chorion laeve or the decidua reflexa — to the surrounding wall of the uterus. A third embryonic appendage, which we have already mentioned — the amnion or "water-membrane" — is also, like the allantois, one of the characteristic features of the three higher classes of vertebrates. We have introduced the amnion when dealing with the severance of the embryo from the embryonic vesicle (p. 308). We found that its walls rise about the embryonic body in the form of a circular fold. In front this fold rises to some height in what is called the hood or sheath of the head (Fig. 222 ks); behind also it curves over considerably as the hood or sheath of the tail fss); to the right and left the fold is at first lower, and is known as the side-hood or sheath (Fig. 226). All these " hoods " or " sheaths " are merely portions of a continuous circular fold longitudinal section goes through the sagittal or middle plane of the body, which cuts it into right and left halves 1 in li.y. 225 the foetus is seen from the left. In Fig. 221 the prochorion I ' </ ). dotted with villi (d'J, encloses the embryonic vesicle, the wall oi which consists of the two primary germinal layers. Between the outer (a) and inner- ( i ) germinal layer the middle layer ( m) has developed in the region of the germinative area. In Fig. 222 the embryo ( ,■ ) begins to separate from the embryonic vesicle fds), while the wall of the amniotic fold rises round it (in front as head-sheath, is , behind as tail-sheath, ss). In Fig. 221, the edges of the amniotic fold ( ttm ) meet over the back of the embryo, and thus form the amniotic cavity (ah); the embryo < e J separating still more from the embryonic vesicle fils), the alimentary canal (do) is formed, the allantois (al) growing out of its hinder end. In Fig. 224 the allantois <"<;/> is larger, the yelk-sac (ds) smaller. In that runs round the embryo. It grows higher and higher, rises up like a rampart, and at last curves like a grotto over the body of the embryo. The edges of the circular fold touch and join (Fig. 227). Thus in the end the embryo is enclosed in a membranous sac, which is filled with the amniotic fluid (Figs. 224, 225 ah). When the sac is completely closed, the inner plate of the fold, which forms the real wall of the amniotic sac, separates altogether from the outer. The latter attaches itself internally to the prochorion, replaces it, and becomes itself the permanent outer envelope of the embryo, described by Baer as the " serous membrane." This serolemma consists, like the thin wall of the amnion-sac, of two layers — the neural and the parietal germ-layers. The latter is in this case very thin and delicate, but can easily be recognised as a direct continuation of the skin-fibre layer. Naturally, in harmony with the folding process, the parietal middle layer is turned inwards in the serolemma and outwards in the amnion. The space between it and the allantois is the periccelom or the interamniotic cavity (the extra-embryonic body-cavity, Fig. 209 al). The phylogenetic cause of this ontogenetic formation of the amnion is to be sought on mechanical lines in the fact that the body of the embryo has gradually sunk into the underlying yelk-sac, thus leaving a circular fold of membrane around it. The growth of the latter into a completely closed sac, filled with fluid, is explained on the theory of selection by the great service which so admirable a protective structure offers to the delicate embryo. Of the three vesicular appendages of the amniote embryo which we have now described the amnion has no bloodvessels at any moment of its existence. But the other two Fig-. 225 the embryo already shows the gill-clefts and the rudiments of the two pairs of legs ; the chorion has branched villi. In all five figures : e embryo, a outer germinal layer, m middle germinal layer, i inner germinal layer, am amnion (is head sheath, ss tail sheath), ah amniotic cavity, as amniotic sheath of the umbilical cord, kh embryonic vesicle, i/s yelk-sac (umbilical vesicle), dgvitelline duct, df gut-fibre layer, dd gut-gland layer, al allantois, vl=hh place of heart, d ovolemma or prochorian, d' villi of same, sh serous membrane (serolemma), sz villi of same, ch chorion, chs villi of same, st terminal vein, / periccelom or seroccelom (the space between the amnion and chorion, filled with fluid). (From Kullikcr.) Cf. Plate VII., Figs. 14 and 15. epithelial plates, but may arise anywhere in holes between the epithelial products of the germ-layers, and were marked off by Hertwig under the title of intermediate layer or mesenchyma. However, according to some observers, the inner vascular epithelium originates from the entoderm. The heart and the blood-vessels and the vascular system generally are by no means among the oldest parts of the animal organism. Aristotle believed that the heart was one which a section of our earliest animal ancestors belonged, have neither blood nor heart. The vermalia were developed at a comparatively late date from these bloodless ccelenteria, and the higher vermalia in which a vascular system of the simplest form developes (frontonia ) later still from the non-vascular lower vermalia (rotatoria); from the higher vermalia are descended the much younger vertebrates. The first blood-vessels of the mammal embryo have been considered by us previously in the transverse sections on Figs. 148-151 (p. 314). They are, firstly, the two primitive embryo of a chick in the region of the shoulder (of the fifth day of incubation). The section passes through the rudimentary foreleg (or wing, e). The amniotic folds are joined over the back of the embryo. (From Remak.) Cf. Figs. 225, 226, and 227; also Plate VII., Fig. 14. arteries or aortas, which lie in the narrow longitudinal clefts between the provcrtebne, the lateral plates, and the gut-gland layer (Figs. 141 t/o, 14800) ; and, secondly, the two principal or cardinal veins, which appear a little later, farther out than the former, above the primitive renal ducts (Figs. 140 157 cur). The heart arises in just the same way and in connection with these first vessels, in the lower wall of the foregut, at the throat, where the heart remains throughout life in the fish. The heart of the vertebrate is originally only a local enlargement of the median visceral vessel, which runs on the lower wall of the gut, and which we have called the principal vein in our study of the primitive vertebrate (Figs. 101, 10^ 7'). The simple, spindle-shaped heart, that we assume to have been here at the limit of the head and trunk, is found at the same spot, immediately behind the gill-gut, in the embryos of the acrania and the cyclostoma (Plate But the two halves soon degenerate and unite, in the ventral middle line of the wall of the fore-gut, to form a single simple tube. The double structure is a later cenogenetic phenomenon, mechanically determined by the flat expansion of the embryonic shield on the large yelk-vesicle. The simple, spindle-shaped structure of the heart, which separates from the ventral wall of the head-gut, consists of the two germinal layers of the gut-wall, a small fold of the gut-gland layer being taken into the tube. From this is formed the endocard, the epithelial inner cellular lining of the heart. Its thick muscular wall, the myocard, is formed by the cells of the gut-fibre layer or visceral middle layer. From this also come the red blood-cells, and the first traces of the vessels that are connected with the heart. These also are vertebrate lies at first in the ventral wall of the fore-gut, or in the ventral (or cardiac) mesentery, by which it is connected for a time with the wall of the body. But the heart soon severs itself from the place of ts origin, and lies freely in a cavity — the cardiac cavity (Fig. 230 c). For a short time it is still connected with the former by the thin plate of the mesocardium (hg). Afterwards it lies quite free in the cardiac cavity, and is only directly connected with the gut-wall by the vessels which issue from it (Fig. 230). Section Of the head of a mammal embryo. /; horny plate, m medullary tube (cerebral vesicle), tnr wall of same, / cutisplate, s rudimentary skull, c/i chorda, /• gillarches, nip muscular plate, c cardiac cavity, foremost part of the body-cavity (cceloma), d alimentary canal, dd gut-gland layer, df visceral muscular plate, hg mesocardium, /iw wall of heart, hi ventricle of heart, ab aorta-arch, a section of aorta-stem. The fore-end of the spindle-shaped tube, winch soon bends into an S-shape (Fig. 232), divides into a right and left branch. These tubes are bent upwards arch-wise, and represent the first arches of the aorta. They rise in the wall of the fore-gut, which they enclose in a sense, and then unite above, in the upper wall of the fore gut-cavity, to form a large single artery, that runs backward immediately under the Fig. 231. Vitelline vessels in the germinative area of a chickembryo, at the close of the third day of incubation. (From Balfour.') The 1 germinative area is seen from the ventral side : the arteries are dark, tin- wins light. // In-art, .l.l aorta-arches, Ao aorta, ROf.A right omphalomesenteric artery, & '/'. sinus terminalis, L.DfumX R.OfTighX and left omphalomesenteric veins, 5. V. sinus venosus, ZXC ductus Cuvieri, S.CaK and I'.Cn fore and hind cardinal veins. chorda, and is called the aorta (Fig. 231 Ao). The first pair of aorta-arches rise on the inner wall of the first pair oi gillarches, and so lie between the first gill-arch ( k ) and the foregut (d), just as we find them throughout life in the fishes. The single aorta, which results from the upper conjunction of these two first vascular arches, divides again immediately into two parallel branches, which run backwards on either side of the chorda. These are the primitive aortas which we have already mentioned ; they are also called the posterior vertebral arteries. These two arteries now give off at each side, behind, at right angles, four or five branches, and these pass from the embryonic body to the germinative area ; they are called omphalo-mesenteric or vitelline arteries. They dog, from the ventral side, magnified about ten times. In front under the forehead we can see the first pair of g*ill-arches ; under- litory divides behind into the two vitelline veins, which expand in the germinative area (which is torn off all round). On the floor of the open belly lie, between the protovertebrse, the primitive aortas, from which five pairs of vitelline arteries are t;iven off. (From Bhchoff. ) mesenteric, veins. Thus, the first embryonic circulation (Figs. 231-234) is arranged in the following simple way in the three higher classes of vertebrates. The simple tubular heart (Fig. 234 d) divides, both in front and behind, into two vessels. The hind it to the embryonic body. The anterior vessels are the efferent branchial arteries, which pass round the fore part of the gut in the shape of the rising aortic-arches ; they unite to form the aorta. The two branches that are formed by the splitting of the main artery — the primitive aortas — give o\( vitelline arteries to right and left, and these pass from the Fig. j^;,. -Embryonic shield and germinative area of a hare, in which wo see the first outline of the blood-vessels, seen from the ventral side. magnified about ton times. The hind end of the simple heart ( n j divides into two strong vitelline veins, and those form a vascular network in the dark area (which looks light on the blaek ground). At the bead-end we can see the fore brain with the two optic vesleles ( b. h ). The darker middle ot the embryo is the wide-open visceral cavity. On each side of the chorda wo see ten protovertebrse. (From Bishoff.) body of the embryo to the germinative area. Here, and in the periphery of the umbilical vesicle, we distinguish two layers of vessels, the surface-layer of arteries and the lower layerof veins. The two are connected. At first this vascular system only extends over the periphery of the germinative area to its border. Here, at the edge of the dark vascular area, all the branches unite in a large terminal vein (Fig. 2,^4 a). This vein disappears later on, when the formation of vessels proceeds further in the course of development, and then the vitelline vessels cover the whole of the yelk-sac. These vessels naturally atrophy with the degeneration of the umbilical vesicle ; their importance is restricted to the first period of the life of the embryo. the first vascular system is fully formed, seen from the ventral side, magnified about five times. The posterior end of the S-shaped heart (d) divides into two strong vitelline veins, each of which gives off a fore (b ) and hind (c) branch. The ends of these unite in the circular terminal vein (a). In the germinative area we see the coarser (deeper-lying) venous net and the finer (more superficial) arterial net. The vitelline arteries ( f ) open into the two primitive aortas ( e ). The dark area, which surrounds the head like an aureole, corresponds to the depression of the head-hood. (From Bischoff.) developed in the wall of the urinary sac or the allantois, as before, from the gut-fibre laver. These vessels grow larger and larger, and are very closely connected with the vessels that develop in the body of the embryo itself. Thus, the secondary, allantoic circulation gradually takes the place of the original vitelline circulation. When the allantois has attached itself to the inner wall of the chorion and been converted into the placenta, its blood-vessels alone effect the nourishment of the embryo. They are called umbilical \esseN, and are originally double — a pair of umbilical arteries and a pair oi umbilical veins. The two umbilical veins (Fig. iq6 //), which convey blood from the placenta to the heart, open at first into the united vitelline veins. The latter then disappear, and the right umbilical vein goes with them, so that henceforth a single large vein, the left umbilical vein, conducts all the blood from the placenta to the heart of the embryo. The two arteries of the allantois, or the umbilical arteries (Figs. 196 /i, 197 «), are merely the ultimate terminations of the primitive aortas, which are stongly developed afterwards. This umbilical circulation retains its importance until the nine months of embryonic life are over, and the human embryo enters into the world as an independent individual. The umbilical cord (Fig. 212 al), in which these large blood-vessels pass from the embryo to the placenta, comes away, together with the latter, in the after-birth, and with pulmonarv respiration begins an entirely new form of circulation, which is confined to the body of the infant. There is a great phylogenetic significance in the perfect agreement which we find between man and the anthropoid apes in these important features of embryonic circulation, and the special construction of the placenta and the umbilical cord. We must infer from it a close blood-relationship of man and the anthropomorphic apes, a common descent of them from one and the same extinct group of lower apes. Huxley's " pithecometra-principle " applies to these ontogenetic features as much as to any other morphological relations : " The differences in construction of any part of the body are less between man and the anthropoid apes than between the latter and the lower apes." This important Huxleian law, the chief consequence of which is " the descent of man from the ape," has lately been confirmed in an interesting and unexpected way from the side of the experimental physiology of the blood. The experiments of Hans Friedenthal at Berlin have shown that human blood, mixed with the blood of lower apes, has a poisonous blood is mixed with that of the anthropoid ape. As we know from many other experiments that the mixture of two different kinds of blood is only possible without injury in the case of two closely related animals of the same family, we have another proof o\ the close blood-relationship, in the literal sense of the word, of man and the anthropoid ape. The existing anthropoid apes are only a small remnant of a large family of eastern apes (or catarrhtnce), from which man was evolved about the end of the tertiary period. They fall into two geographical groups — the Asiatic and the African anthropoids. In each group we can distinguish two genera. The oldest of these four genera is the gibbon ( hylobates, Fig. 235); there are from eight to twelve species of it in the East Indies. I made observations of four of them during my voyage in the East Indies (1901), and had a specimen of the ash-grey gibbon (hylobates leuciscus ) living for several months in the garden of my house in Java. I have described the interesting habits of this ape (regarded by the Malays as the wild descendant of men who had lost their way) in my Malayischen Reisebriefen (chap. xi.). Psychologically, he showed a good deal of resemblance to the children of my Malay hosts, with whom he played and formed a very close friendship. The second, larger and stronger, genus o( Asiatic anthropoid ape is the orang (satyrus); he is now found only in the islands o( Borneo and Sumatra. Selenka, who lias lately published a very thorough Study of the Development and Cranial Structure of Hie . Anthropoid Apes (1899), distinguishes ten races of the orang, which may, however, also be regarded as " local varieties or species." They tall into two sub-genera or genera : one group, dissatyrus (orang-bentang, Fig. 237), is distinguished for the strength of its limbs, and the formation of very peculiar and salient cheek-pads in the elderly male; these are wanting in the other group, the ordinary orang-outang (eusatyrus, Figs. 236, 238). Several species have lately been distinguished in the two genera of the black African anthropoid apes (chimpanzee and gorilla). In the genus anthropithecus (or anthropopithecus, Female. This fresh species, described by Frank Beddard in 1897 as troglodytes ralvus, differs considerably from the ordinary^. niger(Fig. 240) in the structure of the head, the colouring, and the absence of hair in parts. formerly troglodytes) the bald-headed chimpanzee, A. calvus (Fig. 230), and the gorilla-like .1. mafuca (Fig. -241) differ very strikingly from the ordinary antkropithecus niger (Fig. 240), not only in the size and proportion of many parts of the body, but also in the peculiar shape of the head, especially the ears and lips, and in the hair and colour. The controversy that still continues as to whether these different forms of chimpanzee and orang are " merely local varieties " or " true species " is an idle one ; as in all such disputes of classifiers there is an utter absence of clear ideas as to what a species really is. interior of the Cameroons, which seems to differ from the ordinary species (gorilla gina, Fig. 242), not only by its unusual size and strength, but also by a special formation of the skull. This giant gorilla (gorilla gigas, Figs. 243, 244) is two metres and seven centimetres [six feet, ten inches] long; the span of its great arms is 280 centimetres [nine feet]; its powerful chest is twice as broad as that of a strong man. The whole structure of this huge anthropoid ape is not merely very similar to that of man, but it is substantially the same. " The same 200 bones, arranged in the same way, form our internal skeleton ; the same 300 muscles effect our movements ; the same hair covers our skin ; the same groups of ganglionic cells compose the ingenious mechanism of our brain ; the same four-chambered heart is the central pump of their growth, due to adaptation to different habits of life and unequal use o( the various organs. This of itself proves morphologically the descent of man from the ape. We will return to the point in the twenty-third Chapter. But I wanted to point already to this important solution of "the question of questions," because that agreement in the formation of the embryonic membranes and in foetal circulation which I have described affords a particularly weighty proof of it. It is the more instructive as even cenogenetic structures may in certain circumstances have a high phylogenetic value. In conjunction with the other tacts, it affords a striking confirmation of our biogenetic law. Fig. J-h. Giant-gorilla (gorilla gigasj, held by three negroes, kilK-il and photographed by H. Paschen in the interior of the Caraeroons, al Yaunde. (From the UmlauflF Museum ;ii Hamburg, bought for jo, 000 marks by the Rothschild Museum .u Tring.) Total length of the body, from vertex to middle : metres [six feel eight inches] \ the span of the outstretched arms, from one middle-linger to the other, 2.S metres [six feet nine inches]. SYNOPSIS OF THE EMBRYONIC PLATES (LAMELLAE EMBRYONALES) OF THE VERTEBRATES AND THEIR CONNECTION WITH THE CHIEF ORGANS AND TISSUES Hum. in embryos in the foetal membranes. The six figures of these Plates are copied from the fine steel engravings illustrating The Development of Man and the Chick hi the Egg, which Professor Erdl (Munich) published in 1845. All six figures represent human embryos in their natural size, enveloped in tlu'ir membranes. In the first four figures from the second to the sixth week ol development) the mallochorion is cut away, and we see the tiny embryo enclosed in the amnion. The small umbilical vesicle (or rudimentary yelksac) hangs by a thin stalk out ol' the belly of the embryo, and lies in the n or seroccelom (the extra-embryonic body-cavity). (Cf. Plate XIV". and p. 365. 1 Plate xv.. Fig. 5. A human embryo of twelve weeks, within the foetal membranes, natural size (Erdl, Plate XI., Fig. z). The embryo is completely enclosed in the amniotic sac, filled with water, as in a bath. The umbilical cord, which passes from the navel of the embryo to the chorion, is sheathed with a continuation of the amnion, which makes folds at its points oi juncture. Above, the thickly clustered and branched chorion-villi form the placenta. The lower part of the chorion (cut away ami lying in delicate folds) is smooth and tuftless. Underneath it the uterine decidua, also cut away and spread out, hangs in coarser folds. Head and limbs are already far advanced. Plate XVI. A human embryo of five months, natural size (Erdl, Plate XIV.). The embryo is enclosed in the delicate, transparent amnion. which is evil open in front, so that the face and limbs stand out. The back is curved, the limbs drawn up. so that the embryo takes up as little space as possible in the ovum. The eyes are closed. From the navel the thick umbilical cord passes, in serpentine folds, over the right shoulder to the back, and trout there to the spong) placenta (to the right below). The thin outermost membrane, lying in many folds, is the external foetal membrane, the chorion.	155,271	common-pile/pre_1929_books_filtered	evolutionofman01haec	public_library	public_library_1929_dolma-0010.json.gz:3472	https://archive.org/download/evolutionofman01haec/evolutionofman01haec_djvu.txt
f7SpxixJ9XOiW4dt	11: Homogeneous Tax Rates	11: Homogeneous Tax Rates After completing this chapter, you should be able to: (1) construct effective tax rates on defending and challenging investments; (2) describe how effective tax rates depend on investment types; and (3) find effective tax rates on defending and challenging investments by calculating tax adjust coefficients. To achieve your learning goals, you should complete the following objectives: - Learn how to compute a defender’s after-tax IRR by finding its tax adjustment coefficient. - Learn how capital gains alter a defending investment’s tax adjustment coefficient. - Learn how to compute the tax adjustment coefficient for a single period. - Learn how to compare the average effective tax rate for an investment. - Learn how to find the tax adjustment coefficient for loans and investments with increasing (decreasing) cash flow. - Learn how taxes and tax adjustment coefficients influence investment rankings. Introduction According to Benjamin Franklin, taxes are one of the two constants in life (the other one is death). Taxes need to be included in present value (PV) models because only what the firm earns and keeps after paying taxes really matters. Therefore, proper construction of PV models requires that taxes be consistently applied to defending and challenging investments. A single-equation PV model compares two investments: a challenger, described by time-dated cash flow, and a defender, usually described by its internal rate of return (IRR) of its time-dated cash flow. Homogeneous tax rates require that the same units are used when describing the cash flow of the challenger as the cash flow used when finding the IRR of the defender. And in particular, homogeneous tax rates require that when the cash flow of the challenger are adjusted for taxes, the IRR of the defender must also be adjusted for taxes. This chapter shows how to find homogeneous tax rates in PV models. It is popular to adjust a defender’s before-tax IRR to an after-tax IRR by multiplying it by (1 – T ), where T is the average tax rate applied to the investment. This chapter points out that this method for adjusting the defender’s IRR for taxes is only appropriate in a few special cases. Finally, this chapter shows how to find appropriate tax rates for adjusting the defender’s IRR for taxes in a variety of tax environments. After-tax PV Models for Defenders and Challengers The goal is to find a defender’s after-tax IRR. The first step is to find the defender’s before-tax IRR. Recall that the defender’s before-tax IRR is that rate of return such that the NPV of the defender’s before-tax net cash flow is zero. The defender’s after-tax IRR discounts the defender’s after-tax cash flow so that its NPV remains equal to zero. There is an easy test to determine if taxes have been properly introduced into a PV model. First consider the defender’s cash flow stream and its IRR. Then introduce taxes into the defender’s cash flow stream and its IRR. If taxes have been properly introduced, then the NPV of the defender’s after-tax cash flow stream discounted by its after-tax IRR is still zero. To illustrate, consider a defending investment that earns constant net cash flow of R dollars per period in perpetuity. The maximum bid (minimum sell) price V 0 for this defending investment whose before-tax IRR is r . We describe this investment in Equation \ref{11.1}. (11.1) where r = R / V 0 is the before-tax IRR. Now suppose that we describe the defender’s cash flow and the IRR for this same investment on an after-tax basis. We do so by introducing the constant marginal income tax rate T into the model: (11.2) Income R and the before-tax IRR of the defender are both adjusted for taxes by multiplying by (1 – T ). We can be sure that r (1 – T ) is the after-tax IRR, since V 0 is the same in the before and after-tax models. However, we need to be aware that only in the special case of constant infinite income can we multiply r by (1 – T ) to obtain the after-tax IRR. A General Approach for Finding the Defender’s After-tax IRR A general approach for finding the defender’s after-tax IRR follows. Consider a defender that has a market-determined value of V 0 and earns a before-tax cash flow stream of R 1 , R 2 , …, and whose defender’s before-tax IRR is r . A before-tax PV model for this defender can be written as: (11.3) Now we express the PV model for the defender one period later as: (11.4) Note that the bracketed expression in Equation \ref{11.3} equals the right-hand side of Equation \ref{11.4}. This equality allows us to substitute V1 for the bracketed expression in Equation \ref{11.3}. After making the substitution in Equation \ref{11.3} we solve for capital gains equal to: (11.5) Using the expression in Equation \ref{11.5} we can solve for the defender’s before-tax IRR equal to: (11.6) We now want to find the after-tax IRR for the defender described in Equation \ref{11.6}. To do so, the IRR and the cash flow for the defender must be adjusted for taxes in such a way that V 0 in Equation \ref{11.3} is not changed (and the defender’s NPV is still zero). The defender’s cash flow is adjusted for taxes by multiplying them by (1 – T ). The defender’s before-tax IRR is adjusted for taxes by multiplying it by where , a tax adjustment coefficient, adjusts r to its after-tax equivalent such that V 0 is the same whether calculated on a before-tax or after-tax basis. Besides these tax adjustments, let T j equal other taxes applied to the defender’s cash flow that may include property taxes in the case of land, depreciation tax credits in the case of depreciable investments, and capital gains taxes when appropriate for assets earning capital gains. What all these taxes have in common is their functional dependence on the previous period’s asset value. The after-tax PV model corresponding to Equation \ref{11.3} that leaves V 0 unchanged can be written as: (11.7) Similarly, V 1 can be expressed as: (11.8) Replacing the bracketed expression in Equation \ref{11.7} with V 1 , we find the after-tax IRR for the defender as: (11.9) Finally, substituting for r in Equation \ref{11.9} from the right-hand side of Equation \ref{11.6} and solving for , we obtain: (11.10) The value for in Equation \ref{11.10} adjusts the defender’s before-tax IRR to obtain homogeneity of measures between the defender’s after-tax IRR and the defender’s after-tax cash flow in Equation \ref{11.7}. When homogeneity of measures is maintained, the defender’s NPV is still zero whether calculated on a before-tax or after-tax basis. We now find some specific after-tax IRRs for various types of defenders. Case 11.1. and . In this case, the defender earns neither capital gains nor suffers capital losses, in which case T j = 0 . This case is illustrated by an infinite constant cash flow series, described in equations 11.1 and 11.2. Because the cash flow is constant, capital gains are zero. Furthermore, the defender’s return in each period is equal to its cash receipts, which is fully taxed at income tax rate T . Therefore, the entire before-tax rate of return must be adjusted by (1 – T ). In Equation \ref{11.10}, substituting zero for capital gains and depreciation or capital gains tax results in: (11.11) Case 11.2. 0" title="Rendered by QuickLaTeX.com" height="18" width="103" style="vertical-align: -4px;"> and . In this case the investment earns capital gains that are not taxed, which lowers the defender’s effective tax rate. Thus, and . The greater the capital gains, the lower the effective tax rate in period t. We illustrate this type of model next. Consider a defending investment whose before-tax cash flow grows geometrically at rate g . Then before-tax cash flow in period t , R t , equals: R 0 (1 + g ) t , and we write the investment’s IRR model as: (11.12) One period later, we can write: (11.13) and capital gains equal: (11.14) Then, substituting the right-hand side of Equation \ref{11.12} for V 0 in Equation \ref{11.14}, we obtain: (11.15) Now we are ready to find the tax-adjustment coefficient in this model. Substituting into Equation \ref{11.10} for capital gains and first period cash flow, we obtain: (11.16) Suppose that we naively introduced taxes into the growth model described in Equation \ref{11.12} and obtained: (11.17) In this case, an increase in T increases V 0 : (11.18) 0. \end{equation*} " title="Rendered by QuickLaTeX.com"> Since increasing T increases V 0 , we know that r (1 – T ) cannot equal the after-tax IRR for the defending investment. If, for example, r = 8%, g = 3%, then (11.19) Furthermore, for an investor in the 35% tax bracket whose cash flow is increasing at 3%, the effective tax rate would be . Case 11.3. and . In this case the investment suffers capital losses for which no tax savings are allowed, which increases the defender’s effective tax rate. Thus, 1" title="Rendered by QuickLaTeX.com" height="13" width="40" style="vertical-align: -1px;"> and (1 - T)" title="Rendered by QuickLaTeX.com" height="18" width="145" style="vertical-align: -4px;">. The greater the capital losses, the higher is the effective tax rate in period t . We illustrate this type of model next. Consider a defending investment whose before-tax cash flow declines geometrically at rate d > 0. Then before-tax cash flow in period t , R t , equals: , and we write the investment’s maximum bid price as: (11.20) One period later, we can write: (11.21) and capital losses equal: (11.22) Then, substituting the right-hand side of Equation \ref{11.20} for V 0 in Equation \ref{11.22} we obtain: (11.23) Now we are ready to find the tax-adjustment coefficient in this model. Substituting into Equation \ref{11.10} for capital losses and first period cash flow, we obtain: (11.24) If for example, r = 8%, d = 3%, then, (11.25) Furthermore, for an investor in the 35% tax bracket, the effective tax rate on cash flow described by a geometric growth pattern would be The conclusion of Case 11.3 is that suffering losses on investments which are not used to shield income from taxes increases the investor’s effective tax rate. Case 11.4. 0 " title="Rendered by QuickLaTeX.com" height="18" width="103" style="vertical-align: -4px;"> and In this model, the defending investment earns capital gains but pays property tax on its previous period’s value times the property tax rate T p . However, property taxes are tax deductible, so we can write the after-tax IRR model for the defending land investment as: (11.26) We can sum the IRR model above by recognizing that it consists of two geometric sums. However, after summing, V 0 appears on both sides of the equation. Therefore, we solve for V 0 using Equation \ref{11.26} and obtain: (11.27) Capital gains and V 0 in this model are the same as in Case 11.2, which allows us to write: (11.28) Consider the effect of property taxes compared to the geometric model without property taxes. In Case 11.2, we assumed that r = 8% and g = 3%, so that . We continue with the assumption that the decision maker is in the 35% tax bracket and add the assumption that the property tax rate is 2%. We now substitute into Equation \ref{11.28} and find: (11.29) Case 11.5. 0" title="Rendered by QuickLaTeX.com" height="18" width="103" style="vertical-align: -4px;"> and A most fortuitous tax environment is an investment that appreciates but is considered to depreciate at rate d for tax purposes. In this case the investor is not required to pay taxes on the capital gains and is allowed a tax credit for depreciation that occurs only on the books. An example of such a model is the following: (11.30) Because the before-tax model is the geometric growth model, we can write: (11.31) To illustrate, suppose that d = 5%. Then, using numbers from our previous example, we substitute into Equation \ref{11.31} and find: (11.32) In other words, the tax rate for the investment is effectively zero. Tax Adjustment Coefficients in Finite Models So far we have obtained tax adjustment coefficient models for infinite time examples. As a result, the tax adjustment coefficients have been the same for each period. This approach has been convenient for exposition purposes. However, this result is not generally applicable. In practice, the tax adjustment coefficients vary by time period. We demonstrate using a finite time horizon model, a loan model in which the interest paid is tax deductible. In many applications, the defender is a loan. When a loan is the defender, we immediately want to know if the interest paid is tax deductible. To keep our analysis simple, assume a constant-payment loan made for n periods at an interest rate of i percent. In which case, loan amount L 0 at interest rate i with annuity payments A can be written as: (11.33) And the firm’s before-tax IRR is i . The loan balance after one period can be written as: (11.34) Furthermore, capital loss for loans can be expressed as: (11.35) The after-tax IRR model can be expressed as: (11.36) With Equation \ref{11.36} in a familiar form, we can write as: (11.37) In words, the effective after-tax IRR for a loan whose interest is tax-deductible is (1 – T ). Ranking Investments and Taxes In this section, we acknowledge that the effective tax rates vary by the different types of investments being considered. Furthermore, if the effective tax rate for defenders and challengers differ, then before and after-tax investment rankings may be changed. To make this point, consider the following example. Assume the defender’s before-tax IRR is 8%, the income tax rate is 35%, the rate of growth in net cash flow is 3%, and the last year’s before-tax net cash flow was $100. The maximum bid price for this investment with geometric growing income is: (11.38) If the minimum sell price is $3,000, then the NPV for the investment is a negative $940 and the challenger is rejected. Now suppose we introduce taxes into the model and recalculate the investment’s NPV. To simplify we assume an infinite life for the investment and assume for the defender and find: (11.39) Now the challenger’s NPV is positive. Introducing taxes into the NPV model has reversed the ranking: the challenger is now preferred to the defender. These results should alert financial managers to the importance of after-tax rankings. Summary and Conclusions Taxes are important when valuing and ranking investments because what really matters is the amount of your earnings you get to keep after paying taxes. It’s not the before-tax IRR that matters but the after-tax IRR that counts because that’s the rate you really earned on your defending investment. In this chapter, we have introduced a method for finding a defender’s after-tax IRR. The method required that when a defender’s cash flow adjusted for taxes and was discounted by its after-tax IRR its change in NPV was zero. Then we used the equality to find the after-tax discount rate IRR. The implied tax rate in the after-tax IRR was compared to the firm’s average marginal income tax-rate. While the usual practice is to multiply the defender’s before-tax IRR by (1 – T ) to obtain the defender’s after-tax IRR, this chapter demonstrated that this cannot be generally relied on to obtain the defender’s properly adjusted after-tax IRR. Indeed, we demonstrated that capital gains that are not taxed can lower the effective tax rate. Capital losses that do not create tax shields can increase the effective tax rate. Property tax paid on land and other real property increases the effective tax rate paid. Allowing investors to write off an investment’s depreciation lowers the effective tax rate. Finally, this chapter has employed simplifying assumptions, such as large values for n and average depreciation and growth rates, to find effective after-tax discount rates that have nice, closed-form solutions. Usually, this is not the case. It is often more difficult to find effective after-tax discount rates, and often these are not closed-form solutions. Questions - Describe the appropriate test for determining whether or not taxes have been properly introduced into the defender’s IRR. - When finding after-tax IRRs for defenders, we solve for and claim that is the defender’s effective tax rate. Interpret the meaning of . - Under what condition is the defender’s effective tax rate equal to its income tax rate T or that ? - Assume that a defending investment’s price is V 0 , that d is the defender’s book value depreciation rate, that R is the constant stream of income earned by the defender, that T is the income tax rate, and that r is the defender’s before-tax IRR. Also assume that the defender is allowed to write off book value depreciation even though its income stream is constant. We write such a model as: (Q11.1) In this model, the depreciation is constant for 100/d periods beyond which the discounted cash flow is small enough to be ignored. The before-tax IRR model can be written as: (Q11.2) Solve for in the after-tax IRR model by substituting for V 0 the right hand side of the second model R / r . Next, solve for a numerical value for assuming that d = 3% and r = 8%. - Suppose that you have found the NPV for a challenger. What impact will an increase in the defender’s effective tax rate have on the challenger’s IRR? Please explain your answers. - Calculate the effective tax rate for a depreciating challenger where d is the depreciation rate, T is the income tax rate, r is the defender’s before-tax IRR, and V 0 is the price of defender. The IRR model is written below. (Hint: find by setting the right hand side of the equation below to the equivalent model without taxes ( T = 0) and solve for . (Q11.3) - Discuss the following. Suppose that cash flow was constant ( R t = R 0 ), yet tax laws allowed the owner of the durable to claim depreciation at rate d . Without solving for , can you deduce whether it would be equal to, less than, or greater than one? Defend your answer. - Assume you are investing in land and that you borrow money to finance its purchase. Also assume that you pay property taxes on the land. In other words, land is the challenger and the loan is the defender. Which investment has the higher effective tax rate under three scenarios: g = 0, g > 0, and g < 0? What do you need to know about the property tax rate T p to answer this question? - In this chapter, five different investment tax scenarios were described. Please provide an example of each type of investment and how the tax scenario might change its rankings compared to before-tax rankings.	4,088	common-pile/libretexts_filtered	https://biz.libretexts.org/Bookshelves/Finance/Book%3A_Financial_Management_for_Small_Businesses__Financial_Statements_and_Present_Value_Models_(Robinson_et_al)/11%3A_Homogeneous_Tax_Rates	libretexts	libretexts-0000.json.gz:3534	https://biz.libretexts.org/Bookshelves/Finance/Book%3A_Financial_Management_for_Small_Businesses__Financial_Statements_and_Present_Value_Models_(Robinson_et_al)/11%3A_Homogeneous_Tax_Rates
kfYKbpXIo1Q0FCpe	A Practical Guide to Introductory Geology	Summary The topics covered in this chapter can be summarized as follows: \| Section \| Summary \| \|---\|---\| \| 5.1 Weathering \| Rocks weather when they are exposed to surface conditions, which in most case are quite different from those at which they formed. The main processes of mechanical weathering include exfoliation, freeze-thaw, salt crystallization, and the effects of plant growth. Chemical weathering takes place when minerals within rocks are not stable in their existing environment. Some of the important chemical weathering processes are hydrolysis of silicate minerals to form clay minerals, oxidation of iron in silicate and other minerals to form iron oxide minerals, and dissolution of calcite. \| \| 5.2 The Products of Weathering and Erosion \| The main products of weathering and erosion are grains of quartz (because quartz is resistant to chemical weathering), clay minerals, iron oxide minerals, rock fragments, and a wide range of ions in solution. Without weathering, there would not be sediment available to eventually form sedimentary rocks! \| \| 5.3 Clastic Sedimentary Rocks \| Sedimentary clasts are classified based on their size, and variations in clast size and shape have important implications for transportation and deposition. Clastic sedimentary rocks are classified based on their grain size and composition. Clast size, sorting, composition, and shape are important features that allow us to differentiate clastic rocks and understand the processes that took place during their deposition. \| \| 5.4 Chemical Sedimentary Rocks \| Chemical sedimentary rocks form from ions that were transported in solution, and then converted into minerals by biological and/or chemical processes. The most common chemical rock, limestone, typically forms in shallow tropical environments, where biological activity is a very important factor. Names of limestones can be modified with textural terms like crystalline, oolitic, or fossiliferous. Chert is a deep-ocean sedimentary rocks. Evaporites (rock salt and rock gypsum) form where the water of lakes and inland seas becomes supersaturated due to evaporation. Coal forms in swamps from decaying plant remains. \| \| 5.5 Depositional Environments and Sedimentary Basins \| There is a wide range of depositional environments, both on land (glaciers, lakes, rivers, etc.) and in the ocean (deltas, reefs, shelves, and the deep-ocean floor). In order to be preserved, sediments must accumulate in long-lasting sedimentary basins, most of which form through plate tectonic processes. \| \| Lab 5 Exercises \| The best way to learn rock identification is to practice by examining the samples in your Rock Kit 1 and 2. The first step when examining a sedimentary rock is to identify the texture. Clastic sedimentary rocks have clastic textures, and are classified based on grain size, and for sandstones, also by composition. Chemical sedimentary rocks are often monomineralic and are classified based on composition. Chemical sedimentary rocks can have a range of textures (crystalline, clastic, bioclastic, fossiliferous, oolitic, and amorphous). Knowing the diagnostic properties of the main minerals that form chemical sedimentary rocks will help you correctly identify the rock. Just as with mineral samples, different samples of the same rock may not always look exactly the same (e.g., tan versus blue-grey crystalline limestone), but they can always be identified by closely examining the mineral composition and texture. \|	687	common-pile/pressbooks_filtered	https://pressbooks.openeducationalberta.ca/practicalgeology/chapter/summary-lab-5/	pressbooks	pressbooks-0000.json.gz:58281	https://pressbooks.openeducationalberta.ca/practicalgeology/chapter/summary-lab-5/
X7joynHcLnyRDKYd	CBU Academic Calendar 2024-2025	CBU’s Charter of Academic Citizenship Academic Performance Review Office of the Registrar: Updated: September 7, 2021 \| Policy Name \| Academic Integrity Policy \| \| Policy Number \| AC-02 September 2021 \| \| Origin \| Academic Committee \| \| Authority \| Senate \| \| Date of Original Approval \| 2021-09 \| \| Senate Approval Dates \| 2021-09-22 \| \| Effective from \| 2021-09-22 \| \| Review Date \| 2026–06-30 \| \| Responsibility for Review \| Academic Committee \| \| Responsibility for Implementation \| Registrar, Faculty and Deans \| CBU’s Charter of Academic Citizenship outlines five values which underpin academic integrity. These values apply to all areas of work at CBU, from how we conduct ourselves in the classroom to how we lead in our work and community. Originality Ensure that your work is rooted in your own intellectual efforts. A central purpose of the academic enterprise is to extend our own abilities and broaden our perspectives. No one’s work can be said to be wholly unique or original; however, learning and development requires that individuals create work that originates from their own thoughts and efforts. In this way we do not simply reproduce the work of others; instead we create new understandings, reconceive existing concepts, and challenge long-accepted ideas. These efforts towards discovery lead to the growth and refinement of the collective knowledge of humanity. Integrity Honestly represent your own work and respect the ideas, knowledge, and work of others. All legitimate academic work represents honestly and scrupulously, to the best of the scholar’s ability, the results of their study and creativity. Even the most novel scholarship borrows from, is inspired by, and reacts to the work of others. Thus, a core principle of academic life is to fully acknowledge the work of others when it has guided and informed one’s own. Fairness Expect to be evaluated impartially. Everyone deserves to be treated equitably, with the expectation that the standards applied to their work and their progress are reasonably consistent across the institution. Collegiality Treat everyone with respect and dignity. We skeptically and boldly challenge preconceptions and conventional thinking while treating all members of the community with respect. And while university work challenges everyone to do and be their best, the success of one does not preclude the success of another. All can excel. Responsibility Do your part to maintain high standards. All members of the university community take it upon themselves, to the best of their abilities, to work towards maintaining the highest possible standards of academic citizenship as defined by this charter. Academic Integrity Policy 1. Policy purpose The objective of this policy is to promote academic integrity and the values associated with it at Cape Breton University. This document establishes a process to address student conduct that breaches the values of academic integrity. The policy outlines the roles of faculty, staff, students, and others in upholding the values of academic integrity and participating in the process to address student misconduct. 2. Policy scope The policy addresses all forms of academic activity undertaken by students as part of their courses and programs. 3. Related policies and procedures Charter of Academic Citizenship (expanded version) “Appeals of Academic Decisions” “Exam Policy” “Code of Conduct for Non-Academic Infractions” “Confidentiality and Privacy of Student Records” 3.1 Privacy of Student Records All student information that is collected, assessed, shared, and/or reported as part of Cape Breton University’s academic integrity policy is subject to the requirements of its “Confidentiality and Privacy of Student Records” policy. 4. Promoting a culture of academic integrity It is the responsibility of all members of the Cape Breton University community to understand and uphold the highest standards of academic integrity. We demonstrate academic integrity by conducting our work with careful attention to the ethics of our courses, programs, disciplines, and higher education as a whole. The university’s “Charter of Academic Citizenship” explains these ethical commitments and the associated values. The policy also identifies the roles and responsibilities of all members of the Cape Breton University community in the area of academic integrity and the processes, penalties, and rights in place for students who breach academic integrity. 5. Responsibilities 5.1 University The University is responsible for: • promoting academic integrity as a foundational value through policy, administration, and resources; • ensuring that the “Academic Integrity” policy is communicated clearly and is easily accessible; • supporting the creation of educational resources to assist faculty, staff, and students; • collecting data on student academic integrity violations for reporting, disciplinary, educational, and policy purposes; • providing a process through which students may appeal decisions related to academic integrity. 5.2 Students Students are responsible for: • reading, understanding, and acting in accordance with the “Academic Integrity” policy; • reviewing course materials and seeking direction from appropriate faculty and staff to ensure an understanding of the expectations for academic integrity; • engaging in learning opportunities dedicated to academic integrity within and/or outside of classes; • submitting work created in line with the highest standards of academic integrity; • appealing decisions related to academic integrity matters through the proper channels. 5.3 Faculty members Faculty members are responsible for: • educating themselves on the “Academic Integrity” policy and following the policy consistently and equitably; • educating students on accepted practices for using knowledge and sources, and the reasons for those practices; • clearly communicating expectations for the ethical completion of all course assignments, tests, and examinations to students; • making ethical use of any tools for the discovery of academic misconduct; • determining the appropriate response to breaches of academic integrity in consultation, where appropriate, with colleagues, department chairs, and/or Deans. 5.4 Department Chairs Department Chairs are responsible for: • educating themselves on the “Academic Integrity” policy and following the policy consistently and equitably; • providing collegial guidance for faculty in their department on matters related to academic integrity and the seriousness of academic integrity breaches; • assisting students with navigating the “Academic Integrity” policy, when appropriate. 5.5 Deans Deans are responsible for: • educating themselves on the “Academic Integrity” policy and following the policy consistently and equitably; • consulting with faculty members and department chairs on academic integrity breaches; • determining the level and penalty for breaches consistent with section 6; • communicating with the Registrar’s Office and students about academic integrity breaches. 5.6 Appeals Committee of Senate The Appeals Committee of Senate is responsible for: • receiving student letters of appeal, gathering any required evidence, and reaching final decisions about the validity of findings of and/or penalties assigned for academic integrity breaches. Academic Integrity Breaches Cape Breton University recognizes three main types of academic integrity breaches: assignment misconduct, exam misconduct, and other unethical behaviours. Each type of academic integrity breach is defined and explained below. The university retains the right to evaluate other forms of academic integrity breaches not specifically mentioned in this policy and assess appropriate consequences. 6.1 Assignment misconduct Students breach academic integrity when they seek to deceive readers about the truthful origins or nature of their work. Assignment misconduct at Cape Breton University is itself divided into two further categories: 6.1.1 Plagiarism Students plagiarize when they represent the work of others as their own, including words, ideas, information, data, computer code, images, and all other intellectual or creative material. In specific terms, students plagiarize when they submit work that: • appears to be original work when it is, in whole, or in part, drawn from other sources without full and clear acknowledgement; • is copied from other students; • was purchased from, or generated by, a third party or service; • has been previously submitted and graded, in whole or in part, in another course. 6.1.2 Fabrication and Falsification It is a violation of academic integrity to invent data, sources, quotations, or other material with the aim of presenting that material as genuine research or experimental results. Fabrication is not a violation in assignments where invention is specifically called for, as in the creation of art works, hypothetical scenarios and the like. Data of any kind, including quotations, may not be altered so as to be misleading in its use as evidence and results. 6.2 Exam Misconduct Students breach academic integrity when they unfairly represent their knowledge and ability as greater than it is. For the purposes of this policy, exam refers to any examination, test, quiz, or evaluation other than formal written assignments. Whether or not a take-home exam is a written assignment or an exam will be determined by the course instructor and communicated to students. Students commit exam misconduct when they: • look at the work of another student in an effort to reproduce that student’s answer; • ask for, or provide, answers to another student, and similar behaviour, during an exam, test, or quiz; • make use of unapproved notes, references, communications, digital resources, or any other prohibited means of securing answers; • obtain an unauthorized copy of an exam, text, or quiz in advance for the purpose of preparing answers ahead of time; • facilitate the exam misconduct of another student. 6.3 Other Unethical Behaviour CBU recognizes the existence of, and potential for, a range of other unethical behaviour. Other unethical behaviour is itself divided further into two categories. The university retains the right to evaluate other unethical behaviours not specifically mentioned here and assess appropriate consequences. If appropriate, some offenses may also be considered under Cape Breton University’s “Code of Conduct for Non-Academic Infractions.” 6.3.1 Offenses against other students Students breach academic integrity when they intentionally impede the ability of other students to conduct their academic work. Students may not deface, destroy or otherwise compromise the academic products of other students. Students may not unduly interfere with other students’ ability to access course materials, resources, or equipment or access other students’ course work without the knowledge or consent of the student. 6.3.2 Offenses Against the University Students breach academic integrity when they intentionally compromise the valid and legitimate functions of academic supports and services. Students may not fabricate credentials, nor may they make unauthorized alterations to academic documents or records. 7. Seriousness of Academic Integrity Breaches While all instances of academic misconduct undermine academic integrity, CBU recognizes that some transgressions may vary in level of seriousness and that a pattern of misconduct is more serious than a single transgression. The level of seriousness of a breach of academic integrity is determined by evidence of intentionality and pre-meditation. Breaches of academic integrity are therefore categorized into three levels. Assessments of exam misconduct must be conducted in a manner that is consistent with the university’s “Exam Policy” Level of Breaches 7.1 Level 1 Level 1 breaches of academic integrity result from negligence serious enough to create the impression of deception or misrepresentation. Breaches at this level: • include assignment misconduct and exam misconduct; • are addressed by the course instructor in consultation with faculty colleagues and/or department chairs, where appropriate; • are not reported to the Dean; • shall result in a grade penalty and/or additional work proportionate to the breach committed, but not a “0” on the assignment, exam, or in the course; • must be resolved so that the student is provided with additional instruction on integrity matters. 7.2 Level 2 Level 2 breaches show an evident intent to mislead but are limited in scope and premeditation. Breaches at this level: • include assignment misconduct, exam misconduct, and other unethical behaviours; • are addressed by the course instructor in consultation with faculty colleagues, department chairs, and/or Dean, where appropriate; • must be reported to the Dean for inclusion in the student’s academic record; • will result in a significant grade penalty proportionate to the breach to a maximum of “0” on the assignment or exam but not in the course, and a formal letter from the Dean; • must be resolved so that student is provided with additional instruction on integrity matters. 7.3 Level 3 Level 3 breaches demonstrate a flagrant and premeditated transgression of expressed rules and procedures related to academic integrity. Breaches at this level: • include assignment misconduct, exam misconduct, and other unethical behaviours; • are addressed by the course instructor in consultation with faculty colleagues, department chairs, and/or Dean, where appropriate; • must be reported to the Dean for inclusion in the student’s academic record; • will result in a grade penalty of “0” on the assignment or exam, to a maximum of “0” in the course, and a formal letter from the Dean. 7.4 Discontinuation Any student found to breach academic integrity on three separate occasions at Level 2 and/or Level 3 of seriousness will be discontinued from the university for a period of 12 months. The student will not be permitted to register in any CBU courses, for credit, for 12 months as of the date of discontinuance, nor will CBU accept transfer credits from other institutions if they have been earned during that period. The notation for the discontinuation will appear on the transcript for the duration of the discontinuation. 8. Exceptions Notwithstanding these guidelines, the Dean may exercise, in rare cases and on a one-time basis, discretion in cases where the first Level 2 or Level 3 transgression occurred during the student’s first year of study at CBU. In the interest of fairness and consistency only, the Dean may, after consultation with the department chair, modify a penalty assigned to a student as part of a Level 2 and Level 3 breach of academic integrity. Furthermore, the Dean may resolve an extraordinary and flagrant breach of academic integrity by setting aside the requirement for three breaches and discontinue a student immediately. This action must be approved by the Vice-President Academic and Provost. Any actions taken by the Dean under this article must be documented for inclusion in the students’ confidential academic file. 9. Appeals Consistent with the university’s “Appeals of Academic Decisions” policy, students have the right to appeal decisions made under sections 6, 7, and 8 of the “Academic Integrity” policy. 10. Record Keeping and Reporting Academic integrity breaches at Level 2 and Level 3 of seriousness will be reported by the Dean to the Registrar’s Office for inclusion in the student’s confidential academic record. The Registrar’s Office will provide the Vice-President Academic and Provost with a summary of academic integrity breaches on an annual basis.	3,092	common-pile/pressbooks_filtered	https://caul-cbua.pressbooks.pub/cbuacademiccal2425/chapter/ethical-behaviour-in-academic-matters/	pressbooks	pressbooks-0000.json.gz:75827	https://caul-cbua.pressbooks.pub/cbuacademiccal2425/chapter/ethical-behaviour-in-academic-matters/
QUUTktLeF8weFhb-	9.7G: Temperate Bacteriophages - Lambda and P1	9.7G: Temperate Bacteriophages - Lambda and P1 - Evaluate the differences between the temperate phages, P1, and lambda In virology, temperate refers to the ability of some bacteriophages (notable coliphage λ) to display a lysogenic life cycle. Many (but not all) temperate phages can integrate their genomes into their host bacterium’s chromosome, together becoming a lysogen as the phage genome becomes a prophage. A temperate phage is also able to undergo a productive, typically-lytic life cycle, where the prophage is expressed, replicates the phage genome, and produces phage progeny, which then leave the bacterium. With phage the term virulent is often used as an antonym to temperate , but more strictly a virulent phage is one that has lost its ability to display lysogeny through mutation, rather than a phage lineage with no genetic potential to ever display lysogeny (which more properly would be described as an obligately lytic phage). P1 is a temperate bacteriophage (phage) that infects Escherichia coli and some other bacteria. When undergoing a lysogenic cycle, the phage genome exists as a plasmid in the bacterium, unlike other phages (e.g., the lambda phage) that integrate into the host DNA. P1 has an icosahedral “head” containing the DNA, attached to a contractile tail with six tail fibers. The virion is similar in structure to the T4 phage, but simpler. It has an icosahedral head containing the genome attached at one vertex to the tail. The tail has a tube surrounded by a contractile sheath, and ends in a base plate with six tail fibers. The tail fibers are involved in attaching to the host and providing specificity. At around 93Kbp in length, the genome of the P1 phage is moderately large compared to the genomes of others, like T4 (169Kbp), lambda (48Kbp), and Ff (6.4Kbp). In the viral particle it is in the form of a linear double-stranded DNA molecule. Once inserted into the host, it circularizes and replicates as a plasmid. Temperate phage, such as P1, have the ability to exist within the bacterial cell they infect in two different ways. In lysogeny, P1 can exist within a bacterial cell as a circular DNA, in that it exists by replicating as if it were a plasmid and does not cause cell death. Alternatively, in its lytic phase, P1 can promote cell lysis during growth, resulting in host cell death. During lysogeny, new phage particles are not produced. In contrast, during lytic growth many new phage particles are assembled and released from the cell. By alternating between these two modes of infection, P1 can survive during extreme nutritional conditions that may be imposed upon the bacterial host in which it exists. A unique feature of phage P1 is that during lysogeny its genome is not incorporated into the bacterial chromosome, as is commonly observed during lysogeny of other bacteriophage. Instead, P1 exists independently within the bacterial cell, much like a plasmid would. P1 replicates as a 90 kilobase (kb) plasmid in the lysogenic state and is partitioned equally into two new daughter cells during normal cell division. Enterobacteria phage λ (lambda phage, coliphage λ) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli . This virus is temperate and may reside within the genome of its host through lysogeny. Lambda phage consists of a virus particle including a head (also known as a capsid), a tail, and tail fibers. The head contains the phage’s double-stranded circular DNA genome. The phage particle recognizes and binds to its host, E. coli , causing DNA in the head of the phage to be ejected through the tail into the cytoplasm of the bacterial cell. Usually, a “lytic cycle” ensues, where the lambda DNA is replicated many times and the genes for head, tail, and lysis proteins are expressed. This leads to assembly of multiple new phage particles within the cell and subsequent cell lysis, releasing the cell contents, including virions that have been assembled, into the environment. However, under certain conditions the phage DNA may integrate itself into the host cell chromosome in the lysogenic pathway. In this state, the λ DNA is called a prophage and stays resident within the host’s genome without apparent harm to the host. The host can be termed a lysogen when a prophage is present. The virus particle consists of a head and a tail that can have tail fibers. The head contains 48,490 base pairs of double-stranded, linear DNA, with 12-base single-stranded segments at both 5′ ends. These two single-stranded segments are the “sticky ends” of what is called the cos site. The cos site circularizes the DNA in the host cytoplasm. In its circular form, the phage genome therefore is 48,502 base pairs in length. The prophage exists as a linear section of DNA inserted into the host chromosome. Key Points - Many temperate phages can integrate their genomes into their host bacterium ‘s chromosome, together becoming a lysogen as the phage genome becomes a prophage. A temperate phage is also able to undergo a productive, typically-lytic life cycle. - P1 is a temperate bacteriophage (phage) that infects Escherichia coli and some other bacteria. A unique feature of phage P1 is that during lysogeny its genome is not incorporated into the bacterial chromosome, as is commonly observed during lysogeny of other bacteriophage. - Enterobacteria phage λ ( lambda phage, coliphage λ) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli. - With the infection of a bacteria by phage, a lytic cycle usually ensues where the lambda DNA is replicated many times and the genes for head, tail, and lysis proteins are expressed. Under certain conditions the phage DNA may integrate itself into the host cell chromosome in the lysogenic pathway. Key Terms - lytic life cycle : One of the two cycles of viral reproduction (the other being the lysogenic cycle). The lytic cycle is typically considered the main method of viral replication and it results in the destruction of the infected cell. - temperate bacteriophage : Phages able to undergo lysogeny.	1,310	common-pile/libretexts_filtered	https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Boundless)/09%3A_Viruses/9.07%3A_Viral_Diversity/9.7G%3A_Temperate_Bacteriophages_-_Lambda_and_P1	libretexts	libretexts-0000.json.gz:32372	https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Boundless)/09%3A_Viruses/9.07%3A_Viral_Diversity/9.7G%3A_Temperate_Bacteriophages_-_Lambda_and_P1
614QpY57rgzllYuR	The rough road by William J. Locke.	Tha intiiiuta hai anamptad to obtain tha bait original copy anilabia (or filming. Faaturas of tfiii copy which may ba bibliographically uniqua, which may altar any of tha imagai in tha raproduction. or which may lignificantly changa tha uiual mathod of filming, ara chacfcad balow. II se peut qua certaines pages blanches ejouties tors d'une restauration apparaissent dans la taxte. mail, lorsque cela itait possible, ces pages n'ont pas ati filmees. L'Institut a microfilm^ la meilleur exemplaire qu'il lui a M possible de » procurer. Les ditails de cet axamplaire qui sont peut-ftre uniques du point de vua biblioraphkiue. qui pauvent modifier una image reproduite. ou qui peuvent exiger una modification dans la mithode normale de f ihnage sont indiquis ci-dessous. aibllotMqua natlonala du Canada Tha Imaga* appaaring hara ara tha baat quality poailbia considaring tha condition and lagiblllty of tha original copy and in kaaping with tha filming contract spacificatlon. Original copiaa in printad papsr covara ara filmad beginning with tha front covar and anding on the last paga with a printed or illustrated impression, or the back covar when appropriate. All other original copies are filmad beginning on the first paga with a prin;ad or Illustrated Impres sion, and ending on the last page with a print. I or illustrated impression. The last recorded frame on each microfiche shall contain tha symbol —^- (meaning "CONTINUED"), or the symbol V (meaning "END"), whichever applies. Maps, plates, chartt, etc.. may be filmed at different reduction ratios. Those too large to be entirely included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as many frames as lequirad. The following diagrams illustrate the method: Lea images suivantes ont ttt reproduites avac la plus grand soin, compts tenu de la condition at da la nettet de I'exemplaira fiim«, et en conformity avac lea conditions du contrat da filmage. Lea examplairas orlginaux dont la couverture en pepler est imprimte sont fiimto en commenfant par la premier plat et en terminant soit par la dernitre page qui comporte une empreinte d'Impreaaion ou d'llluatratlan, soit par Is aacond plat, aalon la eas. Toua lea autras exemplalras orlginaux sont filmis an common$ant par la pramiire page qui comporte une empreinte li'lmprassion ou d'illustration at an terminant par la darnitre paga qui comporte una telle empreinte. Un dea symbolsa suivants apparaitra sur la derniire Image de cheque microfiche, selon le cas: Is aymboia --signlfie "A SUIVRE", le symbols V signifie "FIN' Les cartas, planches, tableaux, etc., peuvent ttre fiimto t des taux de riduction diffirenta. Lorsque le document eet trop grand pour ttra reprodult en un seul cliche, il est film t partir de I'angle supirieur gauche, de gauche i droite, et de haut en bas, an pranant la nombre d'Images ntoessaira. Les diagrammas suivanu illuatrant la mithoda. CHAPTER I T"^^f\v ^^ story of Doggie Trevor. It tells of his doings and of a girl in England and a fj.» • t^ ° ^/^^®- Cl^efly it is coiTcemedSdth WL Do^^. t' '"^f him to win tCT^Te Hp ;„f ^^^ Trevor did not get the Victoria Cross He got no cross of distinction whatever. He ^d not even attam the sorrowful glory of a Iittl"wWte cr(«s above his grave in the W^tem Front. DogSe was no hero of romance, ancient or modem Xt ot Doggie years before the War was ever thouirht ^e a""^ ^P ^^ ^ ''?'^^* "P from b^h^ like a toy Pom. The ahnost freak o£FsprinK of elderly parents he had the rough world agL^t cut a tooth. His mother was old enough to be his stin t and the bram, such as it is, of an earwig She wrappd Doggie -his real naine Ws S Mannadufe-in cotton-wool and keoT him S until he was ahnost a grown man. Doirrie had never a chance. She ' nought him up l^f a tov IZJ^'i ^' ^^ 7«"^ -«°« - ^d Xn she di3^ Doggie being comfortably oflf, continued thel^: temal tradition and kept on bringing hirnselfun hkeatcyPom. He di/not knowThlt db^to da seu at the edge of the world gazing in timorous far more justice it Z^^ steL^?^™^: W'^h men the world km^aLihi^^ a ^° °f '» '^ast the Doirm^ nf t^T w °°™ne and cares less. Yet meadows sloping riverwerd Hpr^k ^ "® W centuries, wCf thl^^ .J J *• P^^"®?® o^ the the cath^al toS oPoSk "" "5%' ^^ « chnnneys defile^^ Ifr TS^ i ^^•'^^ t^Br^A"^' \'^ ^f^ »' « business to fi^^^ trom Bradshaw, how to get to Durdlehnrv^nnli havmg found t get the,^. ^ for^?£^a^' sentindfed^'r /^"''"^I'r'.^'^^S; silent, sentinelled by unmemonaJ ehns that jruard ^e dignified Gotkic dwellings of the catheTaddiJS! ten^ was Jam^ Mannaduke Trevor b^m.^k father a man of private fortune, was Cmon 0I Durdlebury. For many years he hved in th2 mo^t cpmmo^ous, canonical Luse in the cC^'tThL a new Uean, Dr. Conover, was appointed to Durdlebury, and restless innovator that he^ und^pmied,the North Tranent and split up' Son m^H^^^H T'' T^ * "«"« «°d comfortable maiden lady of ample means, the only and orphan daughter of a late Bishop of Durdlebury Yw& THE ROUGH ROAD had there been such a marrying and grviag in mamage m the Cathedral circlef Chiltfien were born m Decanal, Rectorial, and Canonical homes. tmt a son to the Manningtrees, whom they named Oliver. Then a daugl er to the Conovers. Then a son, named James Marmaduke, after the late Bishop Jessup, was bom to the Trevors. The profane say that Canon Trevor, a profomid patristic thrologian and an enthusiastic palaeontolbgist, oouldn t maie head or tail of it aU,^d, unabll t<; decide whether James Marmaduke should be attributed to the Tertullian or the Neolithic period, ra^ired m an agony of dubiety. At any rate the pobr man died, lie widow, of necessity, moved from the Close, m order to make way for the new Canon and betook herself with her babe to Denby tiau, the comfortable house on the outskirts of the town in which she had dwelt before her marriage. Marmaduke was coddled from his birtL The %.^'iwr'°-l"^^' energetic man, protested. Sar^ Mannmgtree protested. But when lie Dean's eldwt-born died of diphtheria, Mrs. Trevor, in her for^-^?n f"™ ^^ ^^^^ ^ " judgement on Sophia for crmunal carelessness; and when young OEver Mamimgtree gre-^ up to be an intoleraSf yoZ Turk and savage, she looked on Mannadukef and! ^f^u-^"""" ^^\ ^^ ^^ °°t as other boys were wing men Ohver went to school in the town nft^Z ^ u''^^^?^ '"^^ ^ ""d and pmich^ other boys heads, Marmaduke remained at home under the educational charge of a governess. Oliver, lean and lanky and swift-eyed, swaggered through the sUeets unattended from the first day they sent him to a neighbouring kindergarten. As the months and yeare of his childish life passed, he grew more and more mdependent and vagabond. He swore blood brotherhood with a butcher-boy and, unknown to his pious parents, became the leader of a ferocious gang of pu'ates. Marmaduke, on the other hand was never allowed to cross the road without femimne escort. Oliver had the profoundest contempt for Mannaduke. Being two years older, he Ucked him whenever he had a chance. Marmaduke loathed hun. Marmaduke shrank into Miss Gunter the governess's skirts whenever he saw him. Mrs Trevor therefore regarded Oliver as the youthful mcarnation of Beelzebub, and quarreUed bitterly with her sister-in-law. One day Oliver, with three or four of his piratical triends, met Mannaduke and Miss Gunter and a httle toy temer in the High Street. The toy temer was attached by a lead to Miss Gunter on the one side, Mannaduke by a hand on the other. Oliver straddled rudely across the path. "Hallo! Look at the two httle doggies I" he cned. He snapped his fingers at the te-rier. "Come along, Tmyl" The terrier yapped. Oliver grinned and turned to Marmaduke. '^Come alonjt! Fido dear little doggie." your mother, declared Miss Gunter, indignantly. But Oliver and his pirates laughed with the truculence befittmg their vocation, and bowing with u-omcal politeness, let their victim depart to the parody of a popular song: "Good-bye, Doggie, we shall miss you." Frrai that day onwards Marmaduke was known as Doggie" throughout all Durdlebury, save to nis mother and Miss Gunter. The Dean himself origm of the name. _ To preserve him from persecution Mrs. Trevor jealously guarded him from association with other boys. He neither learned nor played any boyish games. In defiance of the doctor, whom she regarded as a member of the brutal anU-Marmaduke League, Mrs. Trevor proclaimed Marmaduke's delicacy of constitution.'; He must not go out into the ram l^t he should get damp, nor into the hot sunshme lest he should perspu-e. She kept him 'ike a precious plant in a carefully warmed conservatory Doggie, used to it firran bhth, looked on it as Ms natural envu'onment. Under feminine guidance and tuiUon he embroidered and painted screens and played the piano and the mandolin, and read Miss Charlotte Yonge and learned history from the late Mrs. Markman. Without doubt his life was a happy one. AU that he asked for was sequestration from Oliver and his associates. Now and then the cousins were forced to meet — at occasional children's parties, for instance. A httle daughter, Peggy, had been bom in the Deanery, replacing the lost first-bom, and festivals, to whidi came the extreme youth of Durdlebury, were given m her honour. She liked Marmaduke, who was live yeara her senior, because he was gentle and clean and wore such beautiful clothes and brushed his hau- somcely; whereas she detested OUver, who even at an afternoon party, looked as if he had just oome out of a rabbit-hole. Besides, Marmaduke danced beautifully; OUver couldn't and wouldn't disdammg such effeminate sports. His great joy was to put out a sly leg and send Doggie and his partner sprawling. Once the Dean caught him at It and caUed him a horrid little beast, and threatened him with neck and crop expulsion if he ever did OUver ^ot him alone, an hour later, in a passage, having lam in ambush for him, and, after a few busy moments, contemplated a bruised and bleeding Doggie blubbering in a comer. It was all very well for the Rev. Vernon Manningtree, when discussing this incident with the Dean, to dismiss Doggie with a contemptuous shrug and call him a Uttle worm without any spirit. The unfortimate Doggie remained a human soul with a human destiny before him. As to his lack of spirit. 'Tm afraid he's a young devil," said the Rector SidZof"am^'^™"^ pnde. "But he hTte ^^as Mannaduke," replied the Dean. Bosh I said Mr. Mannuigtree. When Oliver went to Rugby happier davs than ejrer dawned for Marmadle^ 1^?,^ S o2 the hohdays to fear. But as time went on X W^^K^^^TP^^J.^'^^'- the public 8cho^"bS! JtlaiV^^^ ? existence; so that even the holidays lost their gloomy menace and became like the noraial halcyontide. Meanwhile Doggie mew {V- When he reached the age of fourteenTe D^^ by strenuous endeavour, rescued him from Se unavMbng tmUon of Miss Gunter. But ™ hS ^te'S^l M«J™^<l,f^«.-«> sensitive andC cate- school would kiU him. It would undo aU the results of her unceasing care. It would make hjm coarse and vulgar like other horrid b^s. ^e pe Master of h« old coUege at Cambridge sent hm an exceUent youth who had just taken Ws degree -a second class in the Classical Tripos- an aU-round athlete and a genUeman. The first thing he did was to take Marmaduke on the Uav river that flowed through the Durdlebury meado^ thereby endan«erm,r h& life, wofully bfisteriM h^ hands, and n^RiingTmn ache all over his poorlitUe body After a quarter of an hour's inUrView with She wpi^'^'n t'^'^ "",* >" " ^°"^ candidates. »ne went o London and uilerviewed them all A woman, even of the most limited inteUigence in- geto it. i^.n. Trevor got Phineas McPhail, M.A. Glasgow, B.A. Oxford (TLird Class MathemaU^ Greats), read.'..^ for Holy Oi-iers. ™«">«"«''«»1 6e> my Oxford degree. Vou would have no objecwhn»i° my continuing my theological studies wMe 1 undertake the education of your son?" Phmeas McPhail pleased Mrs. Trevor. He had what she called a rugged, honest Scotch face, with a very big nose ;n the middle of it. and little <frev aroM, he would declare impressively that his sacred duty was the makingof Mcrmadute bto a sS ••o*, • ^Chnstian. 'hiat duty accomSirfJdhf would begin to think of himself JllnrT~ acoountSlhhn the most devSTL ^SiJS Uwt woman ever had. He saw eye to^e w^S fh^ln^T ??}?/'" 'iyste'n^^caUon mI Phail had started hfe with many eager curiositi^ under the unpulse of which he had a^ss^^r^M erable knowledge of a suprficial kind wWd^ IE Z^ "^t ""fV"^^ «°d blandest ofS TwS had she the shghtest suspicion of evil com^ Tn such a pitch o? cmining in the observ^^f tl» propnetfes had he arrived, that thf ^^ se^JaSf knew not of Ws doings. It was only later^X^ ■^ ^^r""* death -when a surveyor was cm!a lound to be half filled with thousands of whiskv bottJ^ secreUy thrown in by Phineas McPhaS ^ Ihe Dean and Mr. Manninjrtree althn.mj. ,v n«.ant of McPhail's habits~K cSSr fc & S tw" parasite on their fo^ste^in! law. And they were nght. But Mrs. Trevor turned a deaf ear to their slanders. They were unworthy to be called Christian men, let alone ministers of the Gospel. Were it not for the sacred associations of her father and her husband, she would never enter the Cathedral again. Mr. McPhail was exactly the kind of tutor that Marmaduke needed. Mr. McPhail did not encourage hini to play rough games, or take long walks, or row on Uie river, because he appreciated his constitutional delicacy. He was the only man in the world during her imhappy widowhood who understood Marmaduke. He was a treasure beyond price. , , . When Doggie was sixteen, fate, fortune, chance, or whatever you like to call it, did him a good turn. It made his mother ill and sent him away with her to foreign health resorts. Doggie and McPhail travelled luxuriously, lived in luxurious hotels, and visited Ja luxurious ease various picture galleries and monuments of historic or aesthetic mterest. The bov, utistically inclined and guided by the ;jle yet weD-informed Phineas, profited greatly. Phineps sought profit to ihem both m other ways. "Mrs. Trevor," said he, "don't you think it a sinful shame for Marmaduke to waste his time over Latin and Mathematics, and such things as he can leam at home, instead of taking advantage of his residence in a foreign country to perfect himself in the idiomatic and conversational use of the language?" Mrs. Trevor, as usual, agreed So thenceforward, whenever they were abroad, v lich was for three or four months of each year, Phineas revelled in sheer idleness, nicotine, and the skilful consumption of alcohol, while highly paid professors taught Marmaduke, and incidentally himself, French and Italian. "I think it may be argued," said Phineas, "that the really beautiful life is dehght in continued sacrifice. Besides, my dear boy, I am not quite so sure as I was when I was young, that by confining oneself within the narrow Umits of a sacerdotal profession, one can retain all one's wider sympathies both with human infirmity ard the gladder things of existence." If Phineas had maintainf i the wily caution which he had exercised for the past seven years, all might have been well. But there came a time when unneedfully he declared once more that he would never desert Marmaduke, and declaring it hiccoughed so horribly and stared so glassily, that Doggie fem-ed he might be ill. He had just lurched into Doggie's own peacock-blue and ivory sittingroom when he was mournfully playing the piano. "You're right, laddie," Phineas agreed, his legs giving way alarmingly so that he collapsed on a brocade-covered couch. "It's a touch of the sim, which I would give you to understand," he continued with a self-preservatory flash, for it was an overcast day in June, "is often magnified in power when it is behind a cloud. A wee drop of whisky is what I require for a complete recovery." Doggie ran into the dining-room and returned with a decanter of whisky, glass and siphon — an adjunct to the sideboard since Mrs. Trevor's death. He lost grip of hunself. He became the scarlet lite. The Dean came to the .oscue of a grateful nephew A s^dft attack of delirium KeS crowned and ended Phineas McPhail's Durdfeb^ Ihe Dean, a comfortable, florid man in the parlv sixties, took up his parable and expounded itfor three-quarters of an hour. If ever youn™ hea^d that which was earnestly meant for lis welf^e Doggie heard it from his Very Reverend S's "And now, my dear boy," said the Dean by way of peroration "you cannot but understand tLut IS your bounden duty to apply yourself to some serious purpose in life.^' " ^"^^ TIffiNCEFORWARD Doggie, like the late Mr. Matthew Arnold's Mow millions, lived alone. He did not complain. There was httle to complain about. He owned a pleasant old house set in fifteen acres of grounds. He had an mcome of three thousand pounds a year. Old Peddle, the butler, and his wife, the housekeeper, saved him from domestic cares. Rising late and retiring early, Uke the good King of Yvetot, he cheated the hours that might have proved weary. His meals, his toilet, his music, his wall-papers, his drawmg and embroidering— specimens of the last he ejchibited with great success at various shows held by Arts and Crafts Guilds and such hke high and artistic fellowships — his sweet peas, his chrysanthemums, his postage stamps, his dilettante readir? and his mild social engagements, filled most satisfyingly the hours not clauned by slumber. Now and then appointments with his taUor summoned him to London. He stayed at the same mildewed old family hotel m the neighbourhood of Bond Street at which his mother and his grandfather the Bishop, had stayed for uncountable years. There he would lunch and dine stodgily in musty state. In the evenings he would go to the plays discussed in the less giddy of Durdlebury ecclesiastical circles. The play over, it never occurred to hhn to do otherwise than drive decorously back to Sturrock's Hotel. Suppers at the Carlton or the Savoy were outside his sphere of thought or opportunity. His only acquaintance in Tvondon were vague elderly female friends of his mother, asm of their divers places of otship T^e days m London thus passed drearily, an/ DowFe wm always glad to get home again. ^* oitt^t?* ^ ^, ^^ '"^""e' bom?' ^Dogrie cu! out the notice, framed it, and stuck it un^n fw. peacock-and-ivory sitting-^oom »* "P m his mente hT'S.wT' ^"^iS*'^'- «^'^ accompUshlaS-homeTf"Sghte%o?„^'^' escort foung bury would l^hlvJ-tr^^i^Dogirwith'i^adaughters. With women, old ani voml 1^^;^ S,S "h^co t? T-^^t-l-tJusI^rwith^com! ^T^'o P ''"^^ ''V^ ^^ exact shade of silk e^lSrS""^? sofa cushion, and had ^* J «mng taste in the selection of weddine nrp«>nt<. Young men other than budding eccEticdS' AlUiough of no mean or revengeful nature, he was hummi enough to feel a httle malicious satislaction when it was proved to Durdleburv that V/r A^^.^"'® ^ ^« "^e^- His Aunt Sarah, Mrs. Manmngtree, had died midway in the Phineas McPhail penod; Mr. Manningtree a year or so later had accepted a Uving in the North of Eneland and died when Doggie was about four-and-twenty. Meanwhde Ohver, who had been withdrawn youne from Rugby, where he had been a thorn in the side ol the authorities, and had been pinned like a cockchafer to a desk in a family counting-house m Lothbury E. C, had broken loose, quirrelled with his father, gone off with paternal malediction and a maternal heritage of a thousand pounds to Calitorma, and was lost to the family ken. When a man does not write to his family, what explanation can there be save that he is ashamed to do so? Ohver was ashamed of himself. He had taken to desperate courses. He was an outlaw. He had gone to the devU. His name was rarely mentioned m Durdlebury — to Marmaduke Trevor's very p-eat and cathke satisfaction. Only to the Dean's ripe and kindly wisdom was his name not utterly anathema. ' "My d^," said he once to his wife, who was deplormg her nephew's character and fate, — "I have hopes of Ohver even yet. A man must have something of the devil in him if he wants to drive the devil out. "My dear Sophia," said he with a twinkle in his mJd blue eyes that had puzzled her from the day when he first put a decorous arm around her waist. My dear Sophia, if you knew what a dinL'-dong scrap of fiends went on inside me before I could Drmg myself to vow to be a virtuous milk-and-water DMty. Then Pegfy Conover, liitherto under the echpse of boarding-schools, finishing sinnd Si X'^'ArC^h ^' T ?^ 'went":;i?hb Ws SSfvei^^reeS^^ ^^e^yprit^X amusingly. He provetf himself to beTSS^ t^v too. He was at W beck aU day lone He r«n nn T\rfu' hefetched and carried. fcS;ealisedTC fully that she owned him. He haunt^ KTane^' One evemng after dinner the Dean said ^' -^e bean laughed. " WeU, I'm not going to do it for you. My chief desire is to re^arise the Eft "'"n-, } «an't have you two running about together aU day and every day. If you likl Let us jom the ladies," said the Dean, in the drawmg-room the Dean exchanged glances with his wife. She saw that he had donlasK^ been bidden. Marmaduke was not an ideal husband tor a brisk, pleasure-loving, modem young wman But where was another husband to come from? Peggy had banned the Church. Marmaduke was wealthy, sound in health, and free from vice It was obvious to maternal eyes 'hat he was in love with Peggy. According to the Dean, if he wasn't, he oughtn t to be forever at her heels. The vouak woman herself seemed to take considerable pleasure All right," she returned cahnly. "Let it h « It^ ^T"-^ Meanwhile we canZ engaged IfU please the dear old birds. I know nil tifrVokim the town have been mewing S^^t m. No^the^ can mew about somebody else." " al ^v rJt^i"^ ^ ^. ''"^y- '""""t's one thing, Jewell^™''' ^ "^ "^^ y«" ^-yon' ta«te S He moved nearer to her. "I suppose -ou know a l^g ttT"' '' •"^° «"^""^ ^-^ ^« -^^ He kissed her somewhat shyly on the lips. She whispered: "I do think I care for vm, nU Amg." M^aduke replied senteXS yf '• YoJ have made me a very happy man." Then thev^t down side by side on the^^fa, and for eS PeggVs mockmg audacity, they could find nothW^i^ T articular to say to each other. ^^^ " lound them poring over the cards in a state of "^ We Ve '^;^ % ''^kf "P' ^'^•^l^d nSded^ . neve fixed it up, Mummy; but we're not going to be married for a year." Doggie went home t»iat evening in a tepid riow. It contented him. He thought hLself the lucK of mortals. A voung man with more passion or magma, on migk have deplored the laTof i^ mance m the Ltrothal. tfe might have d^ on the part of the maiden eith^ more shS^ ready to shrivel, as at a toudi of frost, in the cool around her. But Doggie was not such a young man. Such passrons as heredity had endowed him with had been drugged by training No tdS of mmortal love had ever fir^ his bfood (^f somewhere abroad, the unprinci; led McPhail f3 tan readme Manon Lescaut~he had bought a cheap copy Tiaphazard, -and taking the Std)le volume out of fcs hands, asked him Ihat he Sih? ._-Ay, laddie," replied McPhail, greatly relieved. Thi HnT?^ ^T ?'"'■'=«' ^ the roSt of ^e matto SL« w'' ""/ no^ada^s we put them into tihP Z,;k f «.'°«V^'=«?e the author for Uving m wi^ £Sf "^iftlV"' ^"""^ P«^«=tlv contented wiui lumself with Peggy Conover, with his Unde ??.1 ^"^' of whom KrtWto he had been iusJn i?,hr^'fK'^.,?^7^P«P««- with wTfeather-g^ w th Gohath, his almost microscopic Belgitmg?iffra' 7^^Z\°^ NUe-green silk uSderwefrThfl had Tn^^ntK ?y n'" ^'^ ^^ "«w chauffeur Briggins - (parentheticaUy ,t may be remarked that a sev^ hour excursion m this vehicle, youth in the bade uons;— with the starry heavens above, with the weU-ordered earth beneath them, and with dl T^t^ ^"lgf on the earth, indudLg Gemans Turks, Infidels and Heretics -aU savf one^md gat. as he learned from a letter dehver^ by ^e pledged himself to go up to London the next day to buy an engagement ring. So, after all, the mamcurist's defection did not matter. All was again well with the world. Then he went to bed and slept the sleep of the just and perfect man living the just and perfect life in a iuat and perfect universe. THE shadow cast by the great apse of the Cathedral slanted over the end of the Deanery garden, leaving the house in the blaze of the afternoon sun, and divided the old red-brick wall into a vivid contrast of tones. The peace of centuries brooded over the place. No outside convulsions could ever cause a flutter of her cahn wings. As it was thirty years ago, when the Dean £u«t came to Durdlebury, as it was three hundred, sbc hundred years ago, so it was now; and so it would be hundreds of years hence as long as that majestic pile housing the Spirit of God should last. Thus thought, thus, in some such words, proclauned the Dean, sitting in the shade, with his hands clasped behind his head. Tea was over Mrs. Conover. thin and faded, still sat by the little table, wondermg whether she might now blow out Uie lamp beneath the silver kettle. The game had abeady started on the court some Uttle distance oiT — the players being Dorothy, Peggy, and a couple of athletic, flannel-clad parsons! Marmaduke Trevor reposed on a chair under the lee of Lady Bruce. He looked very cool aud spick and span in a grey cashmere suit, grey shirt, socks and tie, and grey swede shoes. He was discoursing to his neighbour on Palestrina. ..-'j^iTT^®'" ^°^ y°" have stuck it for so kne " smd the latter. He had been a soldier in hh youih and Ml explorer, and had shot big game. lou were energedc enough when you irf ^ "amf here, said Sir Ar.'ubald. %e all thoufcL vrTa despercte feUow who was goins to rX, 1<1 fV! Ca&edrai, turn the Close intraus^i^Xuint' and generally play the deuce." uweiungs. As the years went on I found I couldn't. The grey changelessness of things got hold of me incorporated me into them.^ \4en I dfe-for I hope I shan't have to resign through doddering fj,™ L^!" ""t^ '^^'" ^'^ Sir Archibald, "but ^ey ought to have caught you before tWs petrifaction set m, and made you a bishop " ^ .'.'^ter you had become petrified." Perhaps so. It is not a place where ambitions nan attam a riotous growth." amouions -'s^r.5^ Tj, ^^^■^% "^^ ^ crusading times Lor ,SZi Chevemx, for mstance. who was the l^r. , perhaps, of your very manor, and an amazing of yoX He^n?H"lf ^'yPT^g «l>e anJ)itions ui youinf He could have had his b shonric- but he knew that the choice lay betweenTi^' Zl whlWalw^Js a; t^'^^l u«™- "!•« The old butler Vo>^'i^ ^°"ld have service of the Deanei^ as t^ T.h!^ f ?^ ,? he had been page and fcStm«n t!. n ^^^^ itself -he cessor, -remo^ th^ ?«?tl° ^- ^onover's predea tra^ of gkW«nH ^^-t^mp and brought out Anyone looking over the garden wall would have beheld a scene typical of the heart of England — a scene of peace, ease, and perfectly ordered comfort. The two well-built young men, one a minor canon, the other a curate, lounging in their flannels, clever-faced, honest-eyed, could have been bred nowhere but in English pubUc schools and at Oxford or Cambridge. The two elderly ladies were of the fine flower of Provincial England; the two old men, so different outwardly, one burly, florid, excpiisitely ecclesiastical, the other thin, nervous, soldierly, each was an expression of high Enghsh tradition. The two young girls, unerringly correct and dainty for all their modern abandonment of attitude, pretty, flushed of cheek, frank of glance, were two of a hundred thousand flowers of girlhood ttiat could have been picked that afternoon in lazy EngUsh gardens. And Marmaduke's impeccable grey costume struck a harmonizing English note of Bond Street and the Burlington Arcade. The scent of the roses massed in delicate splendour against the waU, and breathing now that the cool shade had fallen on them, crept through the still air to the flying buttresses and the window mullions and traceries and the pinnacles of the great English cathedral. And in the midst of the shaven lawn gleamed the old cut-glass jug on its silver tray. Someone did look over the wall and survey the scene: a man, apparently supporting himself with tense, straightened arms on the coping; a man with a lean, bronzed, clean-shaven face, wearing an old soft felt hat at a swaggering angle; a man with a smile on his face and a humorous twinkle in his eyes. By chance he had leisure to survey the scene for some time unobserved. At last he shouted : "Hello! Have none of you ever moved for the last ten years?" young men scrambled to their feet. The Dean rose and glared at the intruder, who sprang over the wall, recklessly broke through the rose-bushes and advanced with outstretched hand to meet him. "HeUo, Uncle Edward!" "Right first time," said the young man, gripping hun by the hand. "You're not looking a day oMer. And Aunt Sophia — "he strode up to Mrs. Conover and kissed her. "Do you know," he went on, holding her at arms' length and looking round at the astonished compcmy, "the last time I saw you all you were doing just the sari<^? "You haven't changed a bit. And you — good Lord! Is this Peggy?" He put his hand on the Dean's shoulder and pointed at the girl. "You're the only thing that's grown. I used to gallop with you on my shoulders all round the lawn. I ^uppose you remember? How do you do?" And without waiting for an answer he kissed her soundly. It was all done with whirlwind suddenness. The tempestuous young man had scattered everyone's wits. All stared at him. Releasing Peggy, "My holy Aunt!" he cried. "There's another of 'em. It's Doggie! You were in the old picture, and I'm blessed if you weren't wearing the same bear-tiful grey suit. How do, Doggie?" He stepped back, smiling at them all, a handsome devd-may-care fellow, tall, tough, and supple, hii nands in the pockets of a sun-stained, doublebreasted bluejacket. He jerked a hand. "In the road. My man's sitting on it. Oh, don't worry about him," he cried Mrdv to the protesting Dean. "He's weU trained. Doggie. "You must really let one of the servants see about your thmgs, Ohver," said Mrs. Conover movmg towards the porch. "What wiU people say?'' He strode after her and kissed her. "Oh vou dear old Durdelbury Aunt! Now I know I'm m England agam. I haven't heard those words for years! tiiem with the news that Sir Archibald's car had been brought round. As soon as he recognized Ohver he started back, mouth agape. "u^^J-i^'r^ ^^.^ "«^^' Burford," laughed Oliver. How did I get here? I dropped from the moon." He shook hands with BuiTord, of whose hfe he bad been the plague during his childhood, proclaimed bun as hardy and unchanging as a gartrovle and mstructed him where to find man and luggaKe! The Bnic^ and the two clerical tennis pllyers departed. Marmaduke was for taking his leave too. All his old loathing of Oliver had suddenly returned. His cousin stood for everything he detested, — swagger, arrogance, self-assurance. He bated the shabby rakishness of his attire, the selfassertive aqmhne beak of a nose which he bad inherited from his father, the Rector. He dreaded his aggressive mascuUnity. He had come back witn the same msulting speech on his hps. His finger-nails were dreadful. Marmaduke draired as fittle M possible of his odious company. But his Aunt Sophia cried out, "You'll surely dine with us to-mght, Marmaduke, to celebrate Oliver's return? And Oliver chuned in, "Do. And don't worry about changing I can't. I've no evening togs. My old ones fell to bits when I was trying to put them on, on board the steamer, and I had to chuck em overboard. They turned up a shark who went tor em. So dont you worry. Doggie, old chap. You look as pretty as paint as you are. Doesn't he, Peggy?" "Of course he'll stay to dinner," said Peggy she looked at Oliver as who should say " him at your peril. He belongs to me." So Doggie had to yield. Mrs. Conovcr went into the house to arrange for Oliver's co nfort and the others strolled round the garden. , "WeU my boy," said the Dean, "so you're back m the old country." " u^ ™oney I want, not work," said Oliver. Ahl" said the Dean, in a tone so thoughtful as just to suggest a lack of sympathy. Oliver looked over his shoulder — the Dean and hunself were preceding Marmaduke and Peggy on the trim gravel path. " Do you care to lend me a tew thousands, DoggieP" 'There's family affection for you. Uncle Edward I 1 ve come half way round the earth to see him and — say, will you lend me a fiver?" mto laughter. "I believe you good people think I've come back broKe to the world. The black sheep returned like a wolf to the fold. Only Peggy drew a correct inference from the valet — wait tiU you see him I vut^^/^^' K""^ ^^^" ge"i°g on- He laid a light hand on the Dean's shoulder. "While all you folks m Durdlebury, especially my dear Doggie, lor the last ten years have been durdling, I've been doing. I've not come ail this way to tap lelations for fivfr-pound notes. I'm swaggering into the K ^"°»" lor Capital —with a great big C." Marmaduke twirled his little moustache. "You've taken to company promoting," he remarked acidly. TT I #j®' J * damn — I beg your pardon, Uncle Edward — we poor Pacific Islanders lisp in damns for want of deans to hold us up — and a joUy good company too. We — that's I and another man — that's all the company as yet — two's conipany, you know — own a trading-fleet." "You own ships I" cried Peggy. "Rather. Own 'em, sail 'em, navigate 'em, stoke em, clean out the boilers, sit on the safety valves when we want to make speed, do every old thing — " ' "And what do you trade in?" asked the Dean. ^^ Copra, beche de mer, mother of pearl — " "Mother of pearl! How awfully romantici" cned Peggy. "We've got a fishery. At any rate, the conc^ion. To work it properly we require capital. That 8 why I'm here — to turn the concern into a limited company." The old Dean shot a swift glance at his nephew; then took his arm and walked on, and looked at the vast mass of the Cathedral and at the quiet English garden in its evening shadow. "Copra, Wc/ie rfe mer, mother of pearl, Huaheine," he murmured. "And these strange foreign things are the commonplaces of your lifel" He pointed to a curious object slouching across the lawn; a short, hirsute man wearing a sailo^ ilu7; ^ ^"""J^* a stump of a blackened pipe. ?nH t^f head was bare; L had very long ^ and great powerful hands protruded at the end of long smewy wrists from inadequate sleeves. A f^. Vir^"^^ eyes shone out of his dark, shaggy i^'^^ ^»^'^^ Dinmonfs. His nose was l^fe and red. He rolled as he walked. Such a sigll had never been seen before in the Deanery gardln. sea-fashion — tiiey were about thirty yards anart -and shouted. "Here, you I WhalthTeteffi blazes are you doing here?" eternal He marched off across the lawn; and, could thev cTJ"^^ '• }5\fri«°dly talk that he had S Chipmunk would have made the Saint and the Divmes, and even the Crusader, Sir Guy de Ch^veiS who^ were buned m the Cathedral, turn in S oowii to think. In its way it was a very beautiful Se^Tt^Th'P^t""' ^'^ Poportio^ed faS peacock-blue. Through he P..rt„:,?J J^'fly drawn across an alcove could be guess^ t^ H^™ monstrosity of a grand piano^ 0^ t^j closed cabinet was devoted to s collection of wall-papers. Another, open, to .. coUect/on of httle dogs ,n china, porcelain, faience,- thousands ol them; he got them throu<'h Honl^-. <v " ., the world. He had the finest collection S'inc" hand over to his personal use some o^tl^apaAZnt possibly the present drawing-room, which recdved So ,t h'^^^^l ■«'«':« °^ the afternoon sun wS should he do? Live in the sordidness of discoloured wall-paper for another year, or go throueh the anf lety of artistic effort and manufacturerVs/ipily and delay, to say nothing of the exnense nn'^^v t?^ nT -K ^hole tJung scrapped befo^e^ tC 'wSnl mS" HthadT^^'^"'^'^^ clilemmas%r3: anSerfe^^lJ^ta^^SoTaTtr^^^^^^^ ^^ ^'^ how the schooner had E'caugh" iS some tStlv Tnnd. and the masts had been torn out and t^e rudder carried away, and how it had struck a re7f ^l^^J^^r^'^llfl? ^\^ - the hearts f J Yu X r '^^^ till he woke up on a beach and found that the unspeakable Chipmmik had sw^ with hm for a week — or whatever the time was — untd they got to land If hulking, brainless dolts hke Ohver, thought Doggie, like to fool around in schooners and typhoons, they must take the conse^ences. There was nothing to brag about. The higher man was the intellectual, the aesthetic, the artistic being. What did Oliver know of Lydiar^ T^f ^ ^"^ «^^* decoration or Aztec clay dogs? Nothing. He couldn't even keep his socki from sloppmg about over his shoes, ^d there was Peggy aU oyer the fellow, although before dinnar^e had sai-i she couldn't bear thi sight of ^A ?^?Pu i^'^.Frturbed. On bidding him good-mght she had kissed him in the mostpSrfunctory manner - merely the cousinly peck of a dozen J^u^^°~I^^- ^^? ^^^'^ °° thought to the fact that he was dnvmg horie m an open car without an overcoat. He had felt distinctly chilly on Ws arrivd and had t^en a dose of ammoniat^ quinine. Was Pegp s indifference a sign that she had ceased ^^A i ^\,^'^^- But. suppose, as he sincerely and devoutly hoped, it wasn't? Dilemma on dilemma Added to all this, GoUath, the Ld^. htoLlf^te ^'^°?' '«7«'g.Proi'ably overeaten iiimself, had comphcated pains inside, and the callous vet. could or would not come round till the evenmg. In the meantime Goliath mi(?ht die He was at this point of his reflections When, to door ""' * familiar voice outside the delightedly rounlTh7l.,v/ ^°^^® ^ok him men^tsTid S AZ^^^' «^"^ding their Oliver, alS.ougrieL^'^C "f ^^'^'^ ^« light and colouTanH t^o 'h ^ .™« s«°8e of to like hin Sn ttie t^n^t«=^n''^ J"" beginning the collSon Wtle1oir±^°JI' ^^^^^e ^'^'^ '.'My holy Air*hf'<S r"^^- • de.d:'%lZe ™J'Sy°"''^?"^^afunny selfasafu^fdevfl'SsrS fP^'T^^^ of hWI can undei^tend BuTXt thP^f ""? ^^ """?'« of these danm Uttle dogTr ' '''"'^ '' ^^ P"^ : ffit^xt l,7HT;r°°«?'^ trembled lest hi Sins^'vT^ ^^^'"^° J'^'^e over the ivory iTXre tin ™^° ^^^ * feUow a chanc^ the blazes are you «,ing to do with yourS?" If you've nothing better to do than living here snug like a flea on a dog's back, until you get married, you'd better come." "Oh, yes, it would," said Oliver. "It would make you healthy, wealthy, — if you took a fancy to put some money into the pearl fishery, — and wise. I'd show you the world, make a man of you, for Peggy's sake, and teach you how men talk to one another in a gale of wind. "No, sir," said Peddle, "but none of them can get on with their work. He has drunk two quart jugs of beer and wants a third." "It's his great parlour-trick. You just try to do it. Peddle — eg)ecially after two quarts of beer. He's showing his gratitude, poor chap, just like the juggler of Notre Dame in the story. And I'm sure everybody's enjoying themselves?" «M^ni-' ^T'-^^'i ^J.V ' «" yo" wliat. Peddle," said Ohver brightly. "You lure him out into the stable yard with a great hunk of pie — he adores ^-'^iiT-""^ teU him to sit Uiere and eat it till I come. 1 ell him I said so. .'.' Jj ^ ^''a* "^ ^ done, sir," said Peddle. 1 dont mean to be inhospitable," said Doggie after lie butler had gone, "Lt whV do you tike tins extraordmary person about with you?" I wanted him to see Durdlebury and Durdlebury to see him. Do it good," replied Oliver. J.NOW, what about my proposition? Out there of course you U be my guest. Put yourself in charge ol Uupmunk and me for eight months, and vouTl never regret it. What Chipmunk doesn't know about shiM Mid drmk and hard Uvmg isn't knowledge. We U let you down easy — treat you kindly — word of honour. ' Doggie, being a man of intelligence, realised that UUver 8 offer arose from a genuine desire to do him some kmd of service. But if a friendly bull out of ^ .uhiras ot Its affection invited you to accompany him to the meadow and eat grass, what could you do but courteously decline the invitation? This is what Doggie did. He^as a simple-natured, impulsive man. Peggy's spirited attack had caused him to realize that he had treated Doggie with unprovoked rudeness; but then Doggie was such a Uttle worm. Suddenly the great scheme for Doggie's regeneration had entered bis head, and generously he had rushed to begin to put it mto execution. The pair were his blood relations, after aU. He saw his way to domg them a good turn. Peggy, with aU her go, — exemplified by the maimer in which she had gone for him, — was worth the trouble he proposal to take with Doggie. It really was a handsome offer. Most fellows would have jumped at the prospect of being shown round the islands with an old hand who knew the whole thing backwards, from companypromoting to beach-combing. He had not expected such a point-blank, bland refusal. It made him angry. "I'm really most obliged to you, Oliver," said Doggie, finally. "But ofir ideals are so entirely different. You're primitive, you know. You seem to find your happiness in defying the elements, whereas I find mme in adopting the resources of civilisation to circumvent them.' He smiled, pleased with his Uttle epigram. "Which means," said OUver, "that you're afraid to roughen your hands and spoil your compledon." "If you like to put it that way —symbolically." "Symbofically be hangedl" cried Oliver, losing his temper. "You're an effeminate little rotter and I'm through with you. He marched to the door, his j^een silk dressing-gown flM)>nf round his legs, and threw it wide open. "This IS my house. I'm sorry to have to ask you to g3t out of it." "Good day to you," said Doggie; and when the door was shut he went and threw himself, shaken, on the couch, hating Oliver and all his works more than ever. Go about barefoot and swab decks I It was Bedlam madness. Besides being dangerous Itwasmtolerable. Dogrie stayed away from the Deanery all that day. On the morrow he heard, to his reUef, that Uliyer had returned to London with the unedifyiue Chipmunk. He took Peggy for a drive m the Holb-Royce, and told her of Oliver's high-handed methods. She sympathised. She said, however: Us somethmg you can do for me. In the meanwhile you and I can put our heads together and design a topping scheme of decoration. It's not too early to start in right now, for it'll take mon'hs ana months to get the house just as we want it." Happiness once more settled on Doggie Trevor. For the next two or three days he and Peggy tackled ^e serious problem of the reorganization of Denby Hall. Peggy had the large ideas of a limited though acute bram stimulated by social ambitions. When she became mistress of Denby Hall, she intended to reverse the mvisible boundary that included it m Durdlebury and excluded it from the County. It was to be County — of the fine, inner Arcanum of county — and oidy Durdlebury by the grace of No "durdling," as Oliver called it, for lier. Denby Hall was going to be the very latest thing of September, 1915, when she prop<wed, the honeymoon concluded, to take smart and startling possession. Lots of Mrs. Trevor's rotten old stuffy furniture would have to go. Marmaduke would have to revolutionise his habits. As she would have all kinds of jolly people down to stay, additions must be made to the house. Withm a week after her engagement she had devisied all the improvements. Marmaduke's room, with a great bay thrown out, would be the drawing-room. The present drawing-room, nucleus of a new wing, would be a dancing-room, with parquet flooring; when not used for tangos and the fashionable negroid dances, it would be called the morning-room; beyond that there would be a bilUard-room. Above this first floor there could easily be built a series of guest chambers. As for Marmaduke's library, or study, or den, any old room would do. "There were a couple of bedrooms overlooking the stableyard^ which, thrown into one, would do beautifully. With feminine tact she dangled these splendours before Doggie's infatuated eyes, instinctivdy choosing the opportunity of his gratitude for soothing treatment. Doggie telegraphed for Sir Owen Julius, R. A., surveyor to the Cathedral, the only architect of his acquaintance. The great man sent his partner, plain John Fox, who undertook to prepare a design. Mr. Fox came down to Durdlebury on the 28th of July. There had been a lot of siUy talk in the newspapers about Austria and Serbia to which Doggie had given little heed. There was always trouble in the Balkan States. Recently they had gone to war. It had left Doggie quite cold. They were all "Men-y Widow," irresponsible people. They dressed in queer uniforms and picturesque costumes, and thought themselves tremendously important, and were always squabbUng amoni themselves and would go on doing it till the day^ Doom. Now there was more fuss. He had read m the Morning Post that Sir Edward Grw had proposed a Conference of the Great Powers. Only sensible thmg to do, thought Doggie. He dismissed the trivial matter from his mind. On the morning of the 29th he learned that Austria had dedared war on Serbia. StiU, what did it matter? Doggie had held aloof from politics. He regarded them as somewhat vulgar. Conservative bv caste, he had once, when the opportunity was ahnost forced on him, voted for the Conservative candidate of the constituency. European poUtics on the grand scale did not arouse his interest at all. lingland, save as the wise Mentor, had nothing to do with them. StiU, if Russia fought, Franw would have to join her aUy. It was not till he went to the Deanery that he began to contemplate the possibhty of a general European war. For the next day or two he read his newspapers very careOn Saturday, the 1st of August, Oliver suddenly reappeared, proposing to stay over the Bani Holiday. He brought news and rumours of war from the great city. He had found money very tight. Capital with a big C unpossible to obtain. Everyone told him to come back when the present European cloud had blown over. In the opinion of the judicious it would not blow over. There was going to be war and England could not stay out of it. The Sonday mormng papers confirmed all he said. Germany had declared war on Russia. France was involved. Would Great Britain come in, or for ever lose her honour? Cathedral. Burford brought out the tea-tray and Mrs. Conover poured out tea. Sir Archibald and Lady Bruce and their daughter Dorothy were there and Doggie, impeccable in dark purple. Nothing clouded tBe centuries-old serenity of the place. Yet they asked the question that was asked on every And if she came in, as come she must, what would be_ tbe result? All had premonitions of strange shifting of destinies. As it was yesterday so it was to-day in that gracious shrine of unmutability. But everyone knew in his heart that as it was to-day so would it not be to-morrow. Tne very word "war" seemed as out of place as the suggestion of Hell in Paradise. Yet the throb of the War Drum came over the broad land of France and over the sea and half over England, and its echo fell upon the Deanery garden, flung by the flying buttresses and piers and towers of the grey Cathedral. On the morning of Wednesday, the 5th of August, it thimdered all over the Close. The ultimatum to Germany as to Belgium had expired the night before. We were at war. THE firet thing that brought the seriousness of the war home to Doggie was a letter from John ''ox. John Fox, a Major in a Territorial Regiment, was mobilised. He regretted that he could not give his personal attention to the proposed alterations at Denby Hall. Should the plans be proceeded with in Ws absence from the office, or would Mr. Trevor care to wait till the end of the war, which, from the nature of things, could not last very long? Doggie trotted off to Peggy. She was greatly annoyed. "What awful rot! she cried. "Fox, a Major of ArtiUeryl I'd just as soon trust you with a gun. Why doesn't he stick to his architecture?" Peggy, womanlike, forgot that they had approadied him in the first place. "He'd never begin to understand what we want. Fox hinted as much. Now, Fox is modem and up-to-date and sympathetic. If I can't have Fox, I won't have Sir Owen. Why, he's older than Dad I He's decrepit. Can't we get (mother architect?" She flashed a glance at him. She had woven no yoimg girl's romantic illusions around Marmaduke. .Should necessity have arisen, she could have furniahed you with a merciless analysis of his character. But in that analysis she would have frankly included the old. 5uie?ftt^l'^a "^.r ""« - «"d soldiery. The Dm. ^li^'"'' 1[^ unaccustomed oflScers^ndlln^h^^^^^JJ^ Colonel «"d men holdinir the Kin^v ^as luU of eager young looked with^atur«i ^tJ^T^'^' S? ^'^°m PegTy , confided to S^tW-r^°"- P''?^^ bitter^ brawn." It n^Jer enf/ij u^^^l *!f >lamour ol^ early days th^Si 'tE? b^J^^f^^J £t^ fc of die nation would be nS«l ^ k j™'"'^'^ organized Anny and fe^cSpoS ^f^i^^ constituted men whose duty it was to fight; just as we had our well organised NaUonal Church, also composed of peculiarly constituted men, whose duly It was to preach. He regarded himself as remote from one as from the other. One day, walking with Pegjry and Marmaduke in the garden, he said: "I wisfi I could get hold of that confounded fellow, Chipmunk!" Partlv through deference to the good Dean's dehcately hinted distaste for that upsetter of decorous households, Mid partly to allow his follower to attend to his own domestic affairs, he had left Chipmunk m London. Fifteen years ago Chipmunk had parted from a wife somewhere in the neigWurhoorfof the East India Docks. Both being ilfiterate, neither had since communicated with the other. As he had left her earning good money in a factory, his hfteen years separation had been relieved from anxiety as to her material welfare. A prudent. aJthough a beer-lovmg man, he had amassed considerable savmgs, and it was the dual motive of shanng these with his wife and of protecting his patoon from the ever-lurking perils of London, that had brought him across the seas. When Oliver had set hun free m town, he was going in quest of his wite. But as he had forgotten the name of the stree. near the East India Docks where his wife lived, and the name of the factory in which she worked, the successful issue of the quest, in Oliver's opinion, seemed problematical. The simple Chipmunk, however, was quite sanguine. He would run mto her all nght. As soon as he had found her he would let the Captak know. Up to the present he had not conununicated with the Captain. He could give the Captain no definite address, so the This was in the stable-yard, after Chipmunk had shaken some of the dust out of his hair and clothes and had eaten and drunk voraciously. He was now ' sittmg on an upturned bucket and smoking his clay pipe with an au- of solid content. Oliver, lean and supple, his hands in his pockets, looked humorously down upon him. '\|A thing on four legs that kicks like hell." Wotever for? I am't never ridden no 'osses." loure gomg to learn, you unmilitary-lookinir Mldfei^^" scab- You've got to be a ruddy Wac^^ed to enter into the itl'T.! Ca^Sp^°" '^^'^ ^* Dutchman at Samoa. trucSt'S™^"''- He '^e'^bered the hulking, dunno ovr to ride a "oss. I'm a sailoiman, I am. and sailormen don't shave their faces and ride osses. That's why I arsked yer what yer thought ofthis erewar." pipe into his trousers pocket, Chipmunk rolled away A few hours later Oliver, entering his room to dress for dinner, found him standing in the light of the wmdow laboriously fitting studs into a shirt. The devoted fellow having gone to report to his master, had found Burford engaged in his accustomed task of laying out his master's evening clothes -Ohver during his stay in London had provided hunself with these necessaries. A jealous snarl had sent Burford flying. So intent was he on his work, that he did not hear Oliver entjr. Ohver stood and watched him. Chipmunk was swearing wholesomely under his breath. Oliver saw him take up the tail of the shirt, spit on it and begin to rub something. n„Fil° ^^ ^ "? ^."^V' ^'^ ^«"8>ed and laughed, Md the more he looked at Chipmunk the more he T^ fj:. ^'l Chipmunk stood stohd, holding Uie shirt of the awful, wet, thumb-marked front. But It was not at the shut that OUver laughed For Chipmunk, having gone to the barber's was clean-shaven, and revealed himself as one of the ™oft comically ugly of the sous of men. Never mmd,' said OUver, after a while, "you've made the sacrifice for your country." [\|And wot if I get the face-ache?" Id get something that looked hke a face before I'd talk of it," gr&med Oliver. Burford uttered an unheard sigh of reUef Weregoing to enUst in King Edward's Horse. They re our knd. Overseas men. Lots of 'em what you dear good people would caU bad eggs. There you make the mistake. Perhaps they mayn't ilje fresh enough raw for a dainty palate — but for cooking, good hard cooking, by Gosh I nothmg can touch They argued it out in their gentle, old-fashioned way. The Dean quoted examples of sons of Family who had served as privates in the South African war. "Come and join us, James Marmaduke," said OUver across the table. "Chipmunk and me. Three 'sworn brothers to France. Doggie smiled easily. "I'm afraid I can't imdertake to swear a fraternal a£fection for Chipmunk. He and I would have neither habits nor ideals in common." The Dean being ch ed away on business unmediately after dinner, the young men were left alone in the dining-room when the ladies had departed. Oliver poured himself out a glass of port and filled his pipe — an inelegant proceeding of which Doggie disapproved. A pipe alone was barbaric, a pipe with old port was criminal. He held his peace, however. ^_ "James Marmaduke," said Oliver, after a while, "what are you going to do?" Much as Marmaduke disliked the name of "Doggie," he wmced under the irony of the new appellation. Oliver smoked and sipped his port. "I don't WMit to hurt your feelings any more,''^said he gravely, though sometimes I'd like to scrag you— I suppose because you're so different from me. It was so when we were childem together. Now I've CTown very fond of Peggy. Put on the right track, she might turn mto a very fine woman." said Marmaduke. "I do. She is sticking to you very loyally." Ohver was a bit of an ideahst. "The time may come when she'll be up the devU's own tree. She'U develop a patriotic conscience. If she sticks to you while you do nothing, she'U be miserable. If she chucks you, as she probably wiU, she'U be no happier. It s all up to you, James Doggie Marmaduke, old son. You'll have to gird up your loms and take sword and buckler and march away hke the rest. I don't want Peggy to be unhappy. I WMt her to marry a man. lliat's why I pVoposed to take you out with me to Huaheine and try to make you one. But that's over. Now here's the real chance. Better take it sooner than later, lou 11 have to be a soldier. Doggie." "For goodness' sake, don't do thati It makes cold shivers run down my backl " _ Oliver looked at him oddly, put the extinct pipe m his dinner-jacket pocket and rose. "A flaw in the dainty and divine ordering of things makes you shiver now, old Doggie. What wtU you do when you see a feUow digging out another feUow s mtestines with the point of a bayonet? A bigger flaw there somehow I " DURING the next few months there happened terrible and marvellous things which are all set down m the myriad chronicles of the tune; which shook the world and brought the untoown phenomenon of change mto the Close of Di^dlebury. Folks of strange habit and speech watted It m. and gazmg at the Gothic splendour of the place, saw through the mist of autumn and the mist of tears not Durdlebury but Louvam More than one of those grey houses flanking the Cathedral and shanng with it the contmuity of Its venerable hfe, was a house of moummg: not tor loss m the mevitable and not iinkiidly way of human destmy as understood and accepted with long disciphned resignation — but for loss sudden, awful devastating; Tor the gallant lad who had left It but a few weeks before, with a smile on his lips and a new and dancmg Ught of manhood m hS ^es, now with those eyes unclosed and glazed stanng at the pitfless Flanders sky. Not one of Uiose houses but was Unked with a battlefield. Bwond the memory of man the reader of the Litany rxu o°^ °® accustomed invocation on behalf ^the Soverei^ and the Royal Family, the Bishops Priests and Deacons, the Lords oif^ the Council and aU prisoners and captives, and the congregation had lumped them all together m their reswnses with an undifferentiating convention of fervour. What had prisoners and captives, anv more than the l^rds of the Council, to do witfi theu- lives, theu- hearts, their personal emotions? But now — Durdlebsffy men were known to be prisoners in German hands, and after "aU prisoners and captives" there was a long and pregnant sUence, in which was leu the reverberaUon of war against pier and vaulted arch and gromed roof of the cathedral, which was broken too, now and then, by the stifled sob of a woman, before the choir came in with the response 80 new and significant in its appeal — "We beseech thee to hear us, 0 Lord I" And in every home the knitting-needles of women dicked as they did throughout the length and breadth of the land. And the young men left shop and trade and counting house. And younn parsons fretted and some obtamed the Bishop's permission to become Aimy chaplains, and others, snapping their fingers (figuratively) under the Bi^ops nose, threw their cassocks to the netUea and put on the fuU (though in modem times not very splendiferous) panoply of war. And in course of tune the Bneade of Artillery roUed away and new troops toot their place: and Marmaduke Trevor Esquire, of Denby HaU, was called upon to billet a couple of officers and twenty men. Doggie was both patriotic and polite. Having E fra^ent of the British Army in his house, hi did his best to make them comfortable. By Januaiy he had no doubt that the Empire was in peril that It was every man's duty to do his bit. He welcomed the newcomers witib open arms, havimr unconsciously abandoned his attitude of sup«> onty over mere brawn. Doggie saw the necessity of brawn. The more the better. It was every patnotic Enghshman s duty to encourage brawn. iLu- ^^n, '^.^ ^^'^ allowed him, he would have ted his biUeted men every two hours on prime beefsteaks and Burgundy. He threw himself heart and soul mto the reorganisation of his household, oac^rs and men found thernselvcs in clover. The "Imp<MsibleI" Dogpe would reply, filling up the speakers gla^. ^Don't I know what we owe to you fellows? In what other way can a helpless, dehcate crock hke myself show his gratitude and "* ?^e sort of httle way serve his country?" When the sympathetic and wine-filled euest would ask what was the nature of his malady, he would tap his chest vaguely and reply • Here canbe noted a distmct stage in Dogirie's development. He realised the brutaUty of fact. When great German guns were yawning openmouthed at you, It was no use saying "Take the JQMty, homd things away. I don't like them." Ihey wouldnt go unless you took other big guns md fared at them. And more guns were required than could be manned by the peculiarly constituted fellows who made up the artiUery of the original Briti^ Army. New feUows not at aU warlike, peacetiil citizens who had never killed a cat in anger were being driven by patriotism and by conscience to man them. Against Blood and Iron now supreme, the superior, aesthetic, and artistic being was of no avail. You might lament the fall m relative values of coUections of wall-papers and little grieved against PiiSde'^^rfo^ £'Jin7J£y,S?: Mde this tremendous national lS of ^o^?h" w«, "''''* .'P'^tioned his physiM^Mcit^""!; was as real a fact as the (5ennan inuuT Ha w JJ about pitying himself and seeWpfT" "'°* f JJ^rf ?2. u P"^^- The reg&ent moved awav Although she was kind and as mildhr affectionats as ever, he had noticed of late a curiSus^,^" S her manner Convereation did nT 30^^!^ ThCTe seemed to be something at the bark ThL fr.S'"^^ ^*«^f %«° o ^"se that she sooke truly Mof= people of his acquaintance wWh« was by, seemed to be thus XZl The lack of cfln'I t?""'! ''"'^^ ^°"«'** 't ^as obvious. You can t be such an innocent babe as to supDose Deonl« don't talk about you. Thev don't S^t^^^ because they don't Uke to L Zll ^e?^ sISJ jrou wh,te feaUier* i^tead. But^?; tai^to m^ Why isn't Mannaduke in khaki?^ ^v is^^t' Dogpe fighting?' 'I wonder how you S^ Xw him to slack about like thati' - I'vl hadTDret^v rou«h toe fighting your batUes. Xou fancy you've a weak heart. Perhaps "This is very painful," he said, going to the wmdow and stanng out "Very ^d. You are of the same opimon as the young women who sent me that abominable thing." He swung round horrified. "Do you think I'm r!. uning so as to get out of serving in the armyi-~. ii>i.''°'^'°'^y- Unconsciously I thiA you are. What does your doctor say?" Dogpe was taken aback. He had no doctor. Snif not considted one for years, havmg no cause for medicd advice. The old family phyScian ^1«» had attended his mother in her la?™^ ^n^ 2 /'^"I^ ^'■^«°7 P«^<er8 for him as a chUd, had retired from Durdlebury long ago. TWe WM only one person living famfliar wili his con»^!. T;.f°* ^^^ was himself. He made coX Suture. '^"«"'8 fact. Peggy made a htUe "That provM it. I don't believe you have anvt^ wrong with you. The nerves Business made ll^In\ V"^i''"^^'' ^^?- It's horrid! and fw'all/' '"" ^ ««* t»™"«h ^ith it onc^ iwgam. irtt Dr. Murdock to overhaul von thoroughly with a view to the army H he pa^ you. take a commission. Doggie took it. Tt ^f Jj-b'eaiing and contortional p^onnan^ m tus bath-room, if possible a skilf X ^^^ ^eer m a gymnasium - but his words ffuonlhe D^l'sSlT' ""^^^'^^ whenhe h^d ^dS! S hLfe.^"ih,^^. "^^ Dogrie'iiS'hJ saw Heartily Ahl I U soon set t£at right for you. IJl get you something — an india^iibhpp cont vc ice to practise with fof half an W ^a^ n^°«? '^rT'P « '^^"d Uke a goriUa's." ^ But Doggie crept out of bed and put on a violet dressmg-gowTu that clashed horribly with 4^S pyjamas and wandered hke a man in a nMtiS^ to his breakfast. But he could not m H^ swaUowed a cap of coffee and sought rrfL^ fe «"^«>«m- He was frighten^. KoK faghtened, caurfit in a net from which there wS no escape, not Sie tiniest br jak of a mesh. He h^ «»yen his word -and in justice to Doerie he rt ^d that he held his word'sac^-heX^ SveS n^^A u '^^^ ^^° passed— more thii pa? ed. hI woS >^«,«>i°: He would have t«^figM tie would have to hve in a muddy trench sleen in nrSL^ I ''?'^* ^ ^ °®««'' ^ith aD kinds of strange and vulgar men under him, men like Chi^u^k for instance, whom he would nev^r understand. He realised t£at he \TZ^ taUy afrmd of Bnggms, his late chauffeur. He had heard that men at the front lived on some sohd horror called bully-beef dug out of tim ^ some bmud horror called cocoa also drunk out of tins; aiat men kept on their clothes, even their «?^lf'fhLT^ ^} * ,™^: \^« 'at« ra° over them ^^^^^•"^ ^ ^^\ ^* ^"^^ hitherto associated m lis mmd with the most revolting type of tramp, out there made no distinction d^ p^i^ns. I^A^^^^t ^^ «>m™on lot of the lowest Yommy and the finest gentleman. ' Aiid then the iighting. The terror of nh!^ r^' t'^A"^ ^ «^«y «°d being ^ ^ject of revolt and hoiTor to aU Beholders for the rest of hfe. Death. Feverishly he ruffled bis comely hair. Death He was sVprised S S contemplation of it did not freeze tie blood in Ws vems. Yes. He put it clearly before him. He had given his wor<f to Peggy that he would go and e^ himself to Death. Death. What ®^d h mean? He had been brought up in orthodox Oiurch of England ChristiamV. fe flaccid S had never questioned the truth of its dogmas. He behevai. ma general sort of way, that gSod people went to Heaven and bad people went to^HeU as conscience was clear. H^ bad never done any had done nothing in his life to merit eternal bliss in Pwadise, yet, on the other hand, he had committed no action which would justify a kindly and just Creator m consiming him to ihe eternal flames 01 Hell. Sonaehow the thought of Death did not woriy hun. It faded from ha mind, being far less terrible than hfe under prospective conditions. Discomfort, hunger, thirst, cold, fatigue, pafn, above all the terror of his fellows — these werVthe soulrackmg anticipations of this new life into which it was a matter of honour for iJm to plunge. And to an essential gentleman like Doggie amstter of honour was a matter of hfe. And so, dressed in tus pmk pyjamas and violet dressLng-gown, amid the peacock blue and ivory hangings of his boudoir room, and stared at by the countless unsympathetic eyes of his httle china dogs. Doggie Trevor passed through his first Gethsemane. His decision was greeted with joy at the Deanery. Feggy threw her arms round his neck and gave hmi the very first real kiss he had ever received. It revived him considerably. His Aunt Sophia also embraced him. The Dean shook him wwmly by the hand, and talked eloquent patriotism. Dojtjrie akfady felt a hero. He left the house m a gfow but the dnve home in the two-seater was cold, and the pitch dark night presaged other nights of mercilessness m the future; and when Doggie sat alone by Ins fire, sipping the hot milk which Peddle presented hun on a silver tray, the doubts and fears 01 the mommg racked him again. An ignoble possibility occurred to him. IVlurdoch might be wrong. Murdoch might be prejudiced by local go^ip. Would It not be better to go up to London and obtain the opinion of a first-class man to whom he was unknown? There was also another altemaUve. I'hght. He might go to America, and do he 8tole^^Cba^'°„i; r,?^" adventurel thought of hat a^K,^t Sl''"n ^'^°"* alcohol mark it wem ran ^^It ?? traducers of the letter in theb^JZ^V? ^^ ^'7^ «°d posted entrance gates ^^^ ^"''^ ^^^^ beyoMl his Now and tl^ ^£^ ^Z unneccMary exertion, prescribed wX.&hTT'P^^'^u^ "^ ^8 was discoun^by^?Je daS.nl ■''•J='"T«°y N^w W 'T? ^ !i ?"^«' battalion^-the Wew Army. Dates and mstructions were riven The unpr^ of the Royal Arms at the head Ke ^^'- :^^ '^ grotesque, perky lion and uidcom conveyed to Doggie a sense oi^the grip of wme ZIS ^^'; -^^ type-written w^^ l^CdJ mattered. The impress fascinated him. There Wt^Vw""?? away from it. ThoseZ^ pS n ♦K w'* ^ "* ^^^ ='"tch- They headed a Sftt ^^ ^t? ^^ ^^^^' husband and X to look after his mterests. On his last night at home he went wistfully through the fZu3ace S^ ^^:"^S-^oom sacred to L motherTmemo^' the dmmg-room so solid in its half-century of^mfort^his own peacock and ivory, room Tint^Ty hmself, so expressive of his every taste, ever^ mood, every emotion. Those str^e, old-3 musical instnmients-he could ^y S™aU wiUi the l«uch or breath of a master Ld aXveT The oW Italian theorbo. He took it up How DMuties of hfe — things which asserted a ranee of spmtual truths, none the less real and coSto^ because vice and crime and ugliness and nSs^?^ and war co-emted in ghastly ffct Z oTer fe^te of the planet Earth, "fiie sweetness he^ee^rS was as essenUal to the world's spiritual life as th« sweet etenents of foodstuffs to^its phys'aTl^ To the getting together of aU these articW beautv he had devoted tfie years of his youT ^^Z another pomt of view - was he not the guardkn bv inhentance-m other words, by Divine ProviK -of this beautiful English home, the trusted of p^ ,^«rt. of the sacred traditions of i^e^f EngMi hfe that had made England the^nly S toy the only country, he thought, that could mU And he was gomg to leave it all. All tJiaf it whTj l^f^ ^ "§^y «"d ^ ofUfe For what? For horror and lllthiness and uglin^ for everything against which his beautiful S^k and ivory room protested. Doggie's lastni^T at Denby Hall was a troubled one^ ^^ lJXl> o § , "°? ^^M accompanied him to M ff^^ ^l^ "^^ ^ at fiS^tuffy litUe hotd off Bond Street, while Doggie got Ws Idt? ^«\|her. They bought everythinfL ^erTw^f ^ shop that any salesmii a^ured iSi wis Msential for active service. Swonfe^ Te^lvlre field-glasses, pocket-knivea (for Gargantuan Ste?' compass^, mcM-tins, cooking-batteriL SSl bags, waterproofs, boots imiuSierable, toilet^S spnes, drinling cups, thennos flasks field X bonery cases periscopes, tinted glL^Giev^ waBteoats colera belts, portable mSe S ^-plugs. tm-openera cork-screws. notebooL.^I cils, lummous watches, electric torches £^ housewives, patent seat walking-sS - eve^' Amg that the man of comSL bstincti hJd devised for the prosecution of the war ITie amount of warlike equipment with which Doggie with the aid of his Auiit'sophialnd Peg^ encumbered the narrow little passag^ of Stmr^Fs Hotel must have weighed about a ton ""^'' hoit '^»?^^'^ umfonns, several suits, came TI^L, ■ ^^ devoted enormous care to their fit Attired m one he looked beautiful. Pe«f«v dwrL n dinner at the Carlton. She and DogrifKrHe? mother could get wme stuffy old rfation to spfnd the evening with her at Sturrock's. She wE Doggie all to herself, so as to realist the drram^ many disgi^ting and humiliating Cnths. An" ^ she swept through the pahn court and up the broad stairs and wounS through the crowded tables of^e r^taurant with the khakiclad Doggie by her side »»f ^\^T'^. '^'^ "P'^t^l- Here wL Lr LlS; nn^!^^^^^ T^ ^^^ °^ ^« 1»art of champagne. Doggie drank the rest. On getting into b^Te wondered why this rniprecelent^ ^antity of wine had not affected his sobriety. Its^oiSv effect had been to stifle thought. He went to hid «r„J sS ^""^l' ^Z P^^^'« PartinrkL\a?£ such as would conduce to any young man's feUdtr The next mormng Aunt Sophia and Peetrv skw ^ off to his dep6t, with his ton of lugg^^ ^l^ leaned out of the carriage window and exchknffVd w^tv. ,K 5 Then Be settled down in his comer Trl i!- ^T'"? ^'''- B"^ he could not c^™^ trate his attenUon on the morning news TWs strange costume in which he warSothed seen^d luA^^T^.'"^' °° i«"««^the natty^dr^ta wtuch he had been proud to prink the night before but a rugh mare, N^essus-like investiture, siSS some abonunable, burning doom. «g""ymg THOSE were proud days for Peggy. She went about Durcflebury with her S in the ^ and her step was as martial as thoueh she the other girls of the town with a defiant we U A'^^u^'^'^'^ui^^^' •« thoughlX^s^nd" of the abominable feather! In TkSpaky's draSei^ ^tebhs^ent she raked the pis attXe TS with a searching glance. At the v-.thedral service mous exploit to be coward y and brutal What SatTed' eS °' ^^ ^^'^"^^ andTereSS What h»w tr^'f y°"°« men out of the army? What had they known of Mannaduke? As soon as the Jlusion of his life had been dispelled he^d hardily bred young man was a gay adventwe wm W^f ^u?".^ "f consideraBle dfficX Sh^ fel/"' ^If ^ ^^^« so that she could paradi hun be'or.3 fbe town, in the event of there S a the pleasant young clergy had gone. Many of the girls had gone too; Dorothy Bruce to be a probationer in a V. A. D. hospital. If Durdlebury were not such a rotten, out^f-the-world place, the mfinnary would be fuU of wounded soldier^ and she could do her turn at nursing. As thinss were, she could only knit socks for Tommies and a wlk khaki tie for her own boy. But when everybody was doing then- bit, these occupations were not enough to prevent her feeling a Bttle slacker, lie would have to do the patriotic work for both of them, teU her all about himself, and let her share everything with him in imagination. She also expressed her affection for him in shy and slangy Dogpe wrote regularly. His letters were as shy and conveyed less information. The work was nwxl, the houre long, his accommodation Spartan. They were in huts on Salisbury Plain. Sometimes He confessed himself too tired to write more than a few hnes. He had a bad cold in the head. He was better. They had inoculated him against typhoid and had allowed him two or three slack days. The first time he had unaccountably faintedbut he had seen some of the men do the same, and the doctor had assured him that it had nothing to do with cowardice. He had gone for a routemarch and had returned a dusty lump of fatigue. But aftCT haymg shaken the dust out of his moustache — Doggie had a playful turn of phrase now and fu^T^L^i^ 9"«^ "f s'lan^ «aff. he had felt refreshed. Tlien it rained hard and they were aU but washed out of the huts. It was a very strange life — one which he never dreamed could have existed. "Fancy me," he wrote, "glad to sleep on a drenched bed!" There was the riding school Why hadn't he learned to ride as a boy? He had been told that the horse was a noble animal ■nd the friend of man. He waa afraid he would U^usiona shattered. The ho«e was the most iotoW? S^geant-Miuor in the riding school. Pe^ was S?1jSir^f "" ^°' his'fhilosopWc e^LZ^ m narcWups. It was real courage. His lptt«ra contained sSplestatement^ of f^Tut not a worf of complaint On the other hand they were S you"" mlS^be l^^''' y°" ^°"' 1^^^' know vonvf ^ b- '"^"^. " P''e"y thin time. But C leJv?^ 7 splendidly, and when you l^t Then there came a time when his letters otpw mZT'^ t°'t^': . At last they ceaMt'" §^e7 After a week's waiting she sent m anxious tefcaS' THhe answer came back. "Quite well. WmS soon. She waited. He did not write. One evenmg .an umtamped envelope addressed to X hi J fcduke^tn:^^^ ^^ '^•'"^^^ ^ ^«t of in ilfo « f' ^^^ ^'^ '^ as gently as he could m that final mterview. He put his hand ka fatheriy way on Doggie's shoiSder andXde iU were mercUess times. In matters of life and death we coiJd not afford weak links in the chain. Soldiers in high command, with great reputations, had al- I^l^''"i'^-''PP^- ^x1 ^^e^'" ^^ there was hLKt^ '^^^'^- He had always conducted himself hke a genUeman and a man of honour, but he had not the quahties necessary for the comniandin^ of men. He must send in his resignation. n».„ir" '^'J^ "J?, ''• "■" asl'ed Doggie in a choking voice. "I am disgraced foreveT^ ,. ^^^"'pne' .'eflf ted for a moment. P"" « his pack ot fW If: K ^ r^, Y^l^^y he Toy Pom V fault that he had faded. But the Gre^t Hunt could have no use for Toy Poms. At last he took a sheet ot regimental notepaper and wrote: "Deah Trevor. SJh "^ H^ "■^ admiralhn for the plucky tmy in rfi^" ^^'^"^n to (yoercome you/ physical disabilities, and I am only loo sorry tKal the^ should have compelled the resignation of your commission and your severance from the rMirneni. Doggie took a room at the Savoy Hotel, and sat there most of the day, the pulp of a man. He hid gone to the Savoy, not daring to show his face at the famihar Sturrock's. At the Savoy he was but a nuinber unknown, unquestioned. He wore civil- camp — for one can't house a ton of kit in a hut — he had given to his batman. His one desu-e now was to escape from the eyes of his fellow men. He telt that he bore upon hun the stigma of his disgrace, obvious to any casual glance. He was the man who had been turned out of the army as a hopeless incompetent. Even worse than he slacker — for the slacker might have latent th quaUties ttiat he lacked. Even at the best and bnghtest, be could only be mistaken for a slacker, once more the hkely recipient of white feathers from any damsel patnoticaUy indiscreet. The colonel's letter brought hun httle consolation. It is true that he carried It about with him in his pocket-book; but the gibing eyes of observers had not the X-ray power to read it there. And he could not pin it on his hat. Besides, he knew that the kindly Colonel had stretched a point of veracity. No longer could he take refuge in his cherished dehcacy of constitution. It would be a he. Peggy, in her softest and most pitying mood never guessed the nature of Doggie's ordeal. Those letters so brave, sometunes so playful, had been wntten with shaky hand, misty eyes, throbbing head, despau'ing heart. Looking back, it seemed to hun one blurred dream of pain. His brother officers were no worse than those in any other Kitchener regunent. Indeed, the Colonel was unmensely proud of them and sang their praises to any fellow dugout who would Usten to him at the Naval and Military Club. But how were a crowd of young men tramed in the rough and tumble of public schools, universities, and sport, and now throbbing under the stress of the new deadly game, to understand poor Doggie Trevor? "Surely I don't have to sleep in there?" he asked the subaltern who was taking him round on the day of his arrival in camp, and showed him his sc^ualid httle cubby-hole of a hut with its dirty boards, its cheap table and chair, its narrow, sleepdispelling little bedstead. Doggie looked about him helplessly while the comforter smiled grimly. Already his disconsolate attitude towards the dingy hutments of the camp and the layer of thick mud on his beautiful new boots had diverted his companion. Doggie had. The subaltern reported a new kind of animal to the mess. The mess saw to it that Doggie should be crammed with information — but information wholly inc-irrect and misleading, which added to his many "Acuities. When his ton of kit arrived he held u^ unwiUing reception in the hut and found himself obliged to explain to gravely curious men the use for which the various articles were designed. Thw, I suppose, is a new type of Ms-mask?" rVo. It was a patent cooker. Doggie politely ^owed how it worked. He also demonstrated that a sleepmg-bag was not a kit sack of a size unauthorised by the regulations, and that a huge steel-pomted walking-stick had nothing to do with agriculture. He was very weary of his visiters by the time they had gone. The next day the Adjutant advised tan to scrap the lot. So sorrowfully he sent back most of his purchases to London. Then the Imp of Mischance brought as a visitor to the mess a sub from another regiment who belonged to Doggie's part of the country. Why — I'm blowed, if it i-n't Doggie Trevorl" he exclaimed carelessly. "How d'ye do, Doggie?" So thenceforward he was known in the regiment by the hated name. TTiere were rags, in which, as he was often the victun, he was forced to join. His fastidiousness loathed the coarse personal contact of arms and legs and bodies. His undeveloped strength could not cope with the muscle of his young brother barbarians. Aching with the day's fatigue, he would plead, to no avail, to be left alone. Compared with these feared and detested scraps, he considered, in after tunes, battles to be agreeable recreations. Had he been otherwise competent, he might have won through the teasing and the ragging of the mess. INo one dishked him. He was pleasant mannered, good-natured and appeared to bear no malice. True his ignorance not only of the ways of the army but of the ways of their old hearty world, was colossal, his mode of expression rather that of a precise old Church dipiitary than of a sub in a reg;:nent of Fusiliers, his habits, including a nervous shnnking from untidiness and dirt, those of a dear old maid; but the mess thought, honestly, thet he could be knocked into their own social shape, and m the process of knocking carried out their own traditions. Th.y might have succeeded if Doggie had discovered any reserve source of pride from which to draw. But Doggie was hopeless at his work. The mechanism of a rifle filled him with dismay. He could not help shutting his eyes before he pulled the trigger. Inured aU his life to lethargic action, he found the smart, crisp movements of drill ahnost impossible to attain. The Ridmg School was a terror and a torture. Every second he deemed himself in imminent peril of death. Said the Sergeant-Major : Again, what notion could poor Doggie have of command? He had never raised his mild tenor voice to damn anybody in his hfe. At first the tone m which the officers ordered the men about shocked him. So rough, so unmannerly, so unkind. He could not understand the cheery lack of resentment with which the men obeyed. He could not get into the way of miUtary directness, could never check the polite "Do you mind" that came instinctively to his hps. Now if you ask a private soldier whether he nunds doing a thing instead of t«Uing him to do it, his brain begins to get confused. What else save show in divers and ingenious ways that they mocked at his authority? Doggie had the nervous dread of the men that he had anticipated. During his training on parade words of And Doggie tried. Doggie tried very hard. He was mortifiwl by his own stupidity. Little points ot drill and duty that the others of his own standing seemed to pick up at once, almost by instinct, he could only grasp after long and tedious toil. No one reahied that his brain was stupefied by the awful and unaccustomed physical fatigue. And then came the inevitable end. So Doggie crept into the Savoy Hotel and hid hmise^ there, wishing he were dead. It was some hme before he could wire the terrible letter to i'eggy. He did so on the day when he saw that ms resignation was gazetted. He wrote after many anguished attempts: it "A '^f "' "'■'"" ^/"'■^ "^«' the dreadful thina that has happened, because I simply couldn't. I have resigned my commission. Not of my own free will, for, believe me, I would have gone through anythina for your sake, to say nothing of the country and my own self-respect. To put it brutally, I ^have been mmwn out for sheer incompetence. "I neither hope, nor expect, nor want you to continue your engagement to a disgraced man. I release you from every obligation your pity and generosity may think binding. I want you to forget me arid ™5r5',." Ti"- V",'! ""^'^ <> the work of this new world. What I shall do I don't know. I have scarcely yet been able .o think. Possibly I shall go abroad. At any rate J slmnt return to Durdlebury. If women terdme white feathers before I joined, what would Ihey tend me now? It will always 6e my consolation to know thai you once gave me your love, in spite of the pain of realising that I hate forfeited it iy mv unworthiness. "Please tell Uncle Edward (hoi I feel keenly his position, for he was responsible for getting me the commission through General Gadsby. Give my love to my Aunt if she will have it. "We are all desperately disappointed. Perhaps we hurried on things too quickly, and tried you too high all at once. I ought to have known. Oh my poor, dear^ boy, you must have had a dreadful time. Why didnt you tell me? The news in the gazette came upon me like a thunderbolt. I didn't know what to think. I'm afraid I thought the worst, the very worst — that you had got tired of it and resigned of your own accord. How was one to know? Your letter was almost a relief. "In offering to release me from my engagement you are acting like the honourable gentleman you are. Of wurse I can understand your feelings. But I should be a little beast to accept right away like that. If there are any feathers about, I should deserve to have them stuck on to me with tar. Don't think of going abroad or doing anything foolish, dear, like that, till you have seen me — that is to say us, for Dad is bringing Mother and me up to town by the first train to-morrow. Dad feels sure that everything is not lost. He'll dig out General Gadsby and fix up something for you. In the meantime get us rooms at the Savoy, though Mother is worried as to whether it's a respectable place for Deans to stay at. But I know you wouldn't like Doggie engaged the rooms, but he did not meet the train. He did not even stay in the hotel to meet them. He could not meet them. He could not meet the pity in their eyes. He read in Peggy's note a desire to pet and soothe him and call him "Poor little Doggie," and he writhed. He could not even take up an heroic attitude and say to P^gy: "When I have retrieved the past and can bring you an unsuUied reputation, I wfll return and claun you. Till then fareweU. ' There was no retrieving the past. Other men might fail at first and then make good; but he was not like them. His was the fall of Humpty Dumpty. Final irretrievable. ' He packed up his things in a fright and, leaving no address at the Savoy, drove to the Russell Hotel m Bloomsbury. But he wrote Peggy a letter "to await arrival. ' If time had permitted he would have sent a telegram, stating that he was off for lobobk or Tierra del Fuego, and thereby prevented their useless journey; but they had aheady started when he received Peggy's message. Nothing could be done, he wrote, m effect, to her, nothing m the way of redemption. He would not put her father to the risk of any other such humihation. He had learned by the most bitter experience that the men who counted now in the world 8 respect and in woman's love were men of a type to which, with all the goodwiU in the world he could not make himself belong — he did not say to which he wished he could belong with all the agony and yearning of his soul. Peggy must forget him. The only thing he could do was to act up to her generous estimate of him as an honour- able gentleman. As such it was his duty to withdraw for ever from her life. His exact words however, were: "You know how I have always hated slang, how it has jarred upon me, often to your amusement, when you have used it. But 1 have learned m the past months how expressive It may be. Through slang I've learned what I am 1 am a bom rotter.' A girl like you can't possibly love and marry a rotter. So the rotter, having a hngermg sense of decency, makes his bow and exits — God knows where. . Peggy, red-eyed, adrift, rudderless on a frightenmg sea, caUed her father into her bedroom at the bavoy and showed him the letter. He drew out and adjusted his round tortoise-shell rimmed readm^ rfasses, and read it. 'That's a miraculously new Doggie," said he. PMgy clutched the edges of his coat. I ve never heard you call him that before." It has never been worth while," said the Dean. AT the Savoy, during the first stupefaction of his misery, Doggie I id not noticetl particularly the prevalence of khaki. At the Russell it dwelt insistent, like the mud on Salisbury Plain. Men that might have l)een the twin brethren of his late brother officers were everywhere, free, careless, efficient. The sight of them added the gnaw of envy to his heart-ache. Even in his bedroom he could hear the jingle of their spurs and their cheery voices as they clanked along the corridor. On tJie third day after his migration he took a bold step and moved into lodgmgs in Woburn Place. Here at least he could find quiet, untroubled by heartrending sights and sounds. He spent most of his time in dull reading and dispirited walking. For he could walk now — so much had his training done for him — and walk for many miles without fatigue. For all the enjoyment he got out of it, he might as well have marched round a prison yard. Indeed there were some who tramped the prison yards with keener zest. They were buoyei up with the hope of freedom, they could k tk forward to the ever-approaching day when they should be thrown once more into the glad whirl of fife. But the miraculously new Doggie had no hope. He felt for ever imprisoned in his shame. His failure preyed on his mind. He dallied with thoughts of suicide. Why hadn't he saved at any rate, his service revolver? Then he remembered the ugly habit-s of the umnana'»eable thing — how it always kicked its muzzle up in the air. Would he have been able even to shoot himself with it? And he smiled in self-derision Drowning was not so difficult. Any fool could throw himself into the water With a view to the inspection of a suitable spot, b ggie wandered idly, in the dusk of one eve. iiig, .o Waterloo Bridge, and turning his back to the ceaseless traffic, leaned his elbows on the parapet and stared in front of ^m. A few lights already gleamed from Somerset House and the more dimly seen buildings of the Temple. The dome of St. Paul's loomed a dark shadow on a mist. The river stretched below very peaceful, very inviting. The parapet would be easy to climb. He did not know whether he could dive in the approved manner, hands joined over head. He had never learned to swim, let alone dive. At any rate he could fall off. In that art uie Riding School had proved him a past-master. But the spot had its disadvantages. It was too public. Perhaps other bridges might afford more Erivacy. He would inspect them all. It would e something to do. There was no hurr>-. As he was not wanted m this world, so he had no assurance of being welcome in the next. He had a morbid vision of avatar after avatar being kicked from sphere to sphere. At this point of his reflections he became aware of a presence by his side. He turned his head and found a soldier, an ordinary private, very close to him, also leaning on the parapet. Doggie started away, on the point of flight, dreadmg the possible insolence of one of the mer, jf his late regiment. But the voice of the speaker rang in his ears with a strange familiarity, and the great fleshy nose, the high cheekbones and the little grey eyes in the weather-bea'en face suggested Phineas, gaunt and bony, took his arm. "Would It not just be possible," he said, in his old half-pedantic, half-ironic intonation, "to find a locality less exposed to the roar of traffic and the rude jostling of pedestrians and the inclemency of the elements, in which we can enjoy the amenities of a little refined conversation?" It was like a breath from the past. Doggie smiled. " Which way are you going? "Your way, my dear Marmaduke, was ever mine, until I was 8wej)t, I thought for ever, out of your path by a torrential spate of whisky." He laughed, as though it had been a playful freak of destiny. Doggie laughed too. But for the words he had addressed to hotel and lodginghouse folk, he had sj^oken to no one for over a fortnight. The instinctive craving for companionship made Phineas suddenly welcome. "Man," said he, "when I first saw you I thought you had changed into a disillusioned misanthropist. But I'm wrong. You haven't changed a bit." A few minutes later they reached Woburn Place. Doggie showed him into the sittiiig-room on the drawing-room floor. The table was set for Doggie's dinner. Phineas looked round him in surprise. The heterogeneous and tasteless furniture, the dreadful mid- Victorian prints on the walls — one was the "Return of the Guards from the Crimea," representing the landing from the troopship, repellent in its smug unreality, the coarse glass pnd well-used plate on the table, the crumpled nar i in a ring (for Marmaduke, who in his moth- i house had never been taught to dream that a napiun could possibly be used for two consecutive meals!) the general air of slipshod Philistinism, — afl came as a shock to Phineas, who had expected to find in Marraaduke's "rooms" a replica of the fastidious prettmess of the peacock and ivory room at Denby Hall. "No?" said Phineas, with an air of concern. "Man, I'm awful sorry. I know what the coming down feels like. And I, finding it not abhorrent to a sophisticated and well-trained conscience, and thinking you could well afford it, extracted a thousand pounds from your fortune. My dear lad, if Phineas McPhail could return the money — " Doggie broke in with a laugh. "Pray don't distress yourself, Phineas. It's not a question of money. I've as much as ever I had. The last thing in the world I've had to think of has been money." "Then what in the holy names of Thunder and Beauty," cried Phineas, throwing out one hand to an ancient saddle-bag sofa whose ends were covered by flimsy rags, and the other to the decayed ormolu clock on the mantelpiece, "what in the name of common sense are you doing in this awful, inelegant lodging-house? " "I don't knew," replied Doggie. "It's a fact," he continued after a pause. "The scheme of decoration is revolting to every aesthetic sense which I've spent my life in cultivating. Its futile pretentiousness is the rasping irritation of every hour. Yet here I am. Quite comfortable. And here I propose to stay." "That's a long story," said Doggie, looking at his watch. "In the meantime I had better give some orders about dinner. And you would like to wash." McPhail to follow. "I think you'll find everything you want," said he Phmeas McPhail, left alone to his ablutions agam looked round, and he had more reason than ever to ask what it was all about. Marmaduke's bedroom at Denby Hall had been a dream of satin i wood and duU blue silk. The furniture and hangings on his sixteenth birthday. He remembered how he had been bored to death by that stupendous ass ol an old woman — for so he had characterised her — durmg the process of selection and mstallation Ihe present room, although far more luxurious J than any that Phineas McPhail had slept m for " Laddie, I've got it. It's a woman." But Dog^e laughed and shook his head, and, teaving McPhail, took his turn in the bedroom. For the first time since his return to civil life he ceased for a few moments to brood over his troubles. McPhail s mystification amused him. McPhail's personality and address, viewed in the Ught of the past, were full of interest. Obviously he was a man who lived unashamed on low levels. Doggie wondered how he could have regarded him for years with a respect ahnost amounting to veneration. In a cunous unformulated way Doggie felt that he had authority over this man so much older than hunseh, who had once been his master. It tickled mto some kind of life his deadened self-esteem. llcTc, at last, was a man with whom he could con- mI'pwi^* "fu""* altogether incorrect," said McPhail when they sat down to dinner, "i^ nointmg out the sweet uses of adversity. If it had not been for the adversity of a wee bit operatbn? I shoidd not now be on sick furlough. A^ if I had not been on furlough I shouldn't Tiave the pleasure ot this agreeable reconciliation. Here's to vou laddie, and to our lasting friendship." He simipd f» tklT .• Z""?^* ""?' c<-what the plague w the Latin for vintages? But 'twiU serve.^ lie drank agam and smacled his lips. "It wiU even serve very satisfactorily. Good wine at a^rfect £iSZ wrt- ^^^ PhineasT-vicissitudes^e recital of which would wring your heart laddie and md.e angels weep if tffeir lachrS gS cuhnmated four months ago in an attack of fervid and penniless patriotism. No one seemed to want me except my country. She clamoured for me on every hoardmg and every omnibus. "Your mother caught me young, laddie. To a man ot thuty-four, a graduate of ancient and honourabte umversities and a whilom candidate tor Holy Orders, it is a Ufe that would seem to have no attraction whatever. The hours are absurd, the work distasteful and the mode of living repulsive. But strange to say, it fully contentlme. liie secret of happiness hes in the supple adaptabihty to conditions. \Mien I found that it was necessary to perform ridiculous antics with my legs and arms, I entered into the comicality of the Idea and performed them with an indulgent zest wJiich soon won me the precious encomiums of my superiors in rank. When I found that the language of the canteen was not that of the pulpit or the drawu.g-room, I quickly acquired the new vocabulary and won the pleasant esteem of mv equals. But at "I'll give you an illustration — and if you're the man I consider you to be, you'll take a humorous view of my frankness. At present I adapt myselt to a rough atmosphere of coarseness and lustmess ir which nothing coarse or lusty I could do would produce the slightest ripple of a convulsion: but I have my store of a cultivated mind fount of Castaly to drink from whenever I so pW Sni;K'''f '^'^' ^''^'^ ^ l»«d the honour ote responsible for your education, I adapted mvsdf tea hothouse atmosphere in -.hich RespectXuty and the concomitant virtues of SupinenesTond Stoth were cultivated like rare orchids, but^n mv bedroom I kept a secret fount which had its ^uTce in some good Scots distillery " since this spell of oriental ease at &v hS £ developed his philosophy, iUustrath^H^ by h,S dents more or less reputable in his latfr careJr At tew'^'^PleS .WT ""f rP'^«« DogS'^Lr ^ »ili' • "'^i""". ?'aret set his tongue waccine in .-abelaisian reminiscence. After pJis cSi^ks R«i ^i ^"1?^ If y" ^°^ ^"^ to cook them. Borrowed salt and pepper and a litUe stolen butter worked wondera. But they were irritating to f. ff"^^^- He lay on the floor, said he and yelled for fatted calf; but there was no soft-h^ad^ parent to supply it. Phineas McPhaU must be a slave again and work for his living. Then came private coaching, free lance journalism, hunting for secretaryships: the commonplace story humorously told of the wastrel's decline; then a gorgeous efflorescence in light green and gold as the man outside a picture palace in C^erwellwid lasUy, the penniless patriot throwing himself mto the arms of his desirous country. "Pray don't," said McPhafl. "If you had I was gomg to ask you to be kind enough not to 'let jom excel ent landlord, whom I recognize ^ a buUer of the old school, produce it. Butlers of ttie old school are apt, Uke Peddle, to bring in a maddemng tray of decanters, syphons and glasses. You may not beheve me, but I Wen't touched a Tn ^rl t ^.?"* ?^ ^^^ '°'=""^ «f adaptabihty. In order to attain happiness in the army, the first step IS to avoid differences of opinion with the civil and mihtary pohce and non-commissioned officers, and such hke sycophantic myrmidons of authority. Being a man of academic education, it is with difficulty that I agree with them when I'm sober. If 1 were drunk, my bonnie laddie—" he waved a I j?^?^, '^^ »e beU and jrave the ordpr TJ.» landlord brought in bottle and & °''- ^" «ff«n "'"• "y 4^" Marmaduke," said McPhail after an appreciative sip, "now thatThave toW of mvMlf — lh« tfii I ve reached the bed-rock ZaZ Ld^t^'^'^h °i himiiUation and disSr* uT^ " ^ ^ yo" fa«Jt- Instead of training me to be a man you pandered to mfpoor moX?! guest A^^;/^°'''• ^-7°" ^^X' youVe my guest. And as to your uniform, 6od knows I honour every man who wears it." ^ Brwirh'''"Kr'"\™^ a^relictioToTduS But you a have been observmg that in the recent exposition of my philosophy f have not laboS h^T °i-,'^"y "^ disproportionate exaggeS!^ shSl^ "V^ ?T'"'- "'^ fingers ^Lre sik aha^. It's a sign of Koii^^r" ^u Phineas. "No man is altogether bad. In spite ot everything I've always entertamed a warm affection for you, laddie Zd when otT IZ^'^J' bogies jomid about the lome Doggie, always responsive to human kindness was touched. lie felt a note of sincei^^l^ mSi^s tone. Perhaps he had judged him ha^y o^r! teu?' ?W-'" ^^'«°"«tion which ^cPhaSl naa set up — that m every man there must be some flavmg remnant of goodness. ™.pi uf™ * ''"PPy- Pluneas." he said. "I was as mserable an outcast as could be found in Jn^oS^ and when a feUow's down and out. you mu^r for' Uont I know. laddie? Don't I know?" snH F^hineas sympathetically. He reached forThe ci^^^ box- Do you nund if I take another? PerhaM mJ^ti;;^^^'•'™'^' ^^^^^^s in memory of S right 'h^eSdlf'^ °? '^^ ^^' PhiS wal to be able th^ iT ^J^"" ™'^ "^ ^'^ possessions tSr«l ^ Mnlf^ later dajrs, to pour oithT tortured soul mto sympathetic ears. But shame had kept him. stJl kept him, would always S £n K -T ^i ^J"^ ^^°^ !>« loved. Yes ptt had said the diabolicaUy right thing He^dd uot be ashamed to speak to Phineas And there witn surprise. How easy for him, in resoonse to bitter accusation, to cast'the blame on his mother? He hmiself had given the opening. How easy for hmi to ppmt to his predec^rf short tenS^e of office and plead the alternative of carry W out Mrs. Trevor's theory of education or ofi-^Lta his position m favour of same sycophant ev^S W^rving? But he had kept silent . dS stopped short and looked at Phineas ^ithl^ dunAly questioning and quivering H™ ^^ extracte^^fr^^ n^'- ^ f^^i^'^^^ ^""'^^ "JP^t^on tK,th™;t f°°«^'' ^ ^^^'■^ ^as to tei, from Bridge. "^^ ^ ^^^^ """^^^ ™ Waterloo "And now," cried he, at last, a dismally tramV figure, his young face distorted and reTKSs sleek hau- ruffled from the back into unsiehUv perpendicularities (an invariable sign of SaS PWneas waved an interrupting hand. "You've 8«t to go back, laddie. You've got to whiSdl the moral courage m you and go Lack to DuVdlebury. The Dean, with his influence, and theK you have shown me from your Colonel can easiW get you some honourable employmei in eith^ Service not so exacting as the one which you ha^ recently found yourself unable to perform " Have you never contemplated such a possibility?" ^ tiood God, no I said Doggie. "I have enlisted. And I am" a man of ancient bneage as honourable, so as not to enter into^! nffrtf^fT^Tr^'-^" y?H"- And I am a Master of Arts of the two Umversities of Glasgow and Cambridge. Yet I fail to find anything dishonou^X m my present estate as 33702 Private Phineas McPhail in the British Army." -mneas him widl ^™^ °°'' ^ *^" ^" "® ^'^ ■ ''Enlist?" he repeated. "As a Tommy?" Even as a Tommy." said Phineas. He glanced at the armolu clock. "It is past one. -fhTr^ spectable widow woman near the Elephant and Castle who has let me a bedroom, wiU be worn bv anxie.y as to my non-return. Marmaduke, my dear, dear laddie, I must leave you. If vou wifl be lunchmg here twelve hours hence, notfing will give me pater pleasure than to join vou. Laddie sw 'tb d" ' ^°" ''"'* manage a fri^ sole and a He opened the door. Phineas shook hands, tried sole and a sweetbread at one-thirty?" Of course, with pleasure," said Doggie. Phineas fumbled m his pockets. Doggie drew from his patent notecase a sheaf of P"« Pound and Ten Shilling treasury not^ and handedthem over to McPhaU'l vultu^clute^ Good-night, laddie!" AFTER e bath and a change and breakfast ?f^l^r!!' «"t for one of L soUt^ waS' have kent wSfS:.'"'^'' "^f^' ^I '''«^t ^S far worse on Salisbury Plain a„d thl ;r.„ ^ uf ' revfillA ha,i .ri>„„™„j iT-' r'nin, ana Uie inexorable reveiue Jiad dragged him out into the raw drearffnl monung heedless of his headach. J^d'yeaS had^bS.'' xSla! ^^' "^^ P'^^ of hHeS prpTexities of the future than bVal^se^ rZ,^ ;°:ifndi'gdoom FortoPhineiMX?s-'K not? he had been able to give no answer uL could give no answer now, is he mSd wSh So Doggie sketched the outhne of the immortal story of the Boy Who Will Never Grow Old, and the Irishman Ustened with deep interest. "Indeed," said he after a tmie, "it is good to come back to the true things after the things out there." He waved his one arm in the vague direction of the War. They turned away and Doggie found himself sittmg on a bench by the man's side. ^^ "It's not me that can tell you that," said he, and ray wife and children in Galway." He was. A Reservist called back to the colours after some > ears of retirement from the army. He had served m India and South Africa, a hardbitten old soldier, proud of the traditions of the old Regiment. There were scarcely any of them left — and that was all that was left of him. He smiled cheerily. Doggie condoled with him on the loss of his arm. Doggie agreed that he had fought for the greater freedom of humanity and gave him a cigarette, and they went on talking. The Irishman had been m the retreat from Mons, the first battle of Ypres, and he had lost his arm in no battle at all; just a stray shell over the road as they were marchine back to bdlets. They discussed trie war, the eS of hln^"^^!? ^t'll/antfd to know why the reahties ol blood and mud and destruction were not the true things. Gradually he found that the Irish- ZfvJ^Tv!- *'^ ?^ T things were the spiritual, undying things; that the grhn realities woiid pass away; that from these dead realities would arise the noble ideals of the future which would be svin! bohsed in song and marble, that all he had enddred and sacrificed was but a part of the Great Sacrifice we were maWng for the Freedom of the World Being a man roughly educated on a Galway fami ^f .^^- "^^^^V. ••«??""'' h« ^''^ F^«t difficulty m co^rdmating his ideas, but he Ead a curious power of vision that enabled him to pierce to the nis untrained sense of beauty. They parted with expressions of mutual esteem. Doggie struck across tlie gardens with a view to retimung home by Kensington High Street PiccadjUy and Shaftesbury Avenn- He strwle alone with Ms thoughts fdled with the Irish soldier Here Ti^.hl U^k' ""^'"^ \' ^^ «"d I'^t^ content that It should be so who had reckoned all the horrors through which he had passed as externals unworthy ot the consideration of his unconquerable soula man simple, unassumuig, expansive only through his Celtic temperament, which allowed him to talk easily to a stranger before whom his English or Scotch comrade would have been dumb and gaping as an oyster, obviously brave, sincere and loyal. Perhaps something even higher. Perhaps in essence, the very highest. The Poet Warrior. Ihe term struck Doggie's braia with a thud, Uke the explosive fusion of two elements. ing on it, might he not escape? Was he not of too fine a porcelain to mingle with the coarse and common pottery of the ranksP Was it necessary to go into the thick of the coarse clay vessels, just to be shattered? It was easy for Phineas to proclaim that he had foimd no derogation to his dign'''Y as a man of birth and a University graduate i identifying himself with his fellow privates. Phineas had systematically brutalised himself into fitness for the position. He had armed himself in brass — aes triplex. He smiled at his o^vn wit. But he, James Marmaduke Trevor, who had lived his life as a clean gentleman, was in a category apart. Now, he found that his talk with the Irishman had been an antidote to the poison. He felt ashamed. Did he dare set himseu up to be finer clay than that commion soldier? Spiritually, was he even of clay as fine? In a Great Judgment of Souls which of the twain would be among the Elect? The ultra-refined Mr. Marmaduke Trevor of Denby Hall, or the ignorant Poet Warrior of Ballinasloe? "Not Doggie Trevor," he said between his teeth. And he went home in a chastened spirit. sweetbread. "Laddie,"_ said he, "the man that can provide such viands is a Thing of Beauty which, as the poet says, is a Joy for ever. The light in his window is a beacon to the hungry Tommy dragging himself through the viscous wilderness of regulation stew." "I would not take too seriously words sooken in tiie heat of nudnight revelry, even thoSiTe revd was conducted on the gent^elest princ^L Have •j^?°™^'^® ''"^ piece of advice to eive von " 8«d McPhail. "Sii^k the name of jCadS^'e which would only stimulate the ignorantribK vL^^^/'r- «°d «dopt the name of Jame^wS your godfather and godmother, with miracubus foresigk, considering tieir limitations hi S^mS, of coramon sense, have given you " .. \|P^ .^ « good idea," said Doggie. ^,o-^ It would tend to the obUteration of cl-sa prejudices rf you gave up smoking Turkish cigarett^ at ten shilhngs a hundred and ^ivedia yZlZ toon as an amateur of 'Woodbines ' " ^ tntJTi.^.^; ^^ '''™^ o'g^ra is 'S constituted that It can stand the sweepings of the ell phante' house n the Zoologic/ G^-dens TrT Tim tune it's only Woodbines.^' ^' A few days later the Dean received a letter bearing the pencilled address of a camp on the South Coast, and written by 35792 p'^ James M. Trevor, A Company, 2/10 th Wessex Rangers. It ran: "/ hope you won't think it heartless of me to have left you so long without news of me; but until lately I had t}ie same reasons for remaining in seclusion as when I last wrote. Even now I'm not asking for sympathy or reconsideration of my failure or desire in any way to take advantage of the generosity of you all. "I have enlisted in the 10th Wessex. Phineas McPhail, whom I met in London and whose character for good or evil I can belter gauge now than formerly, IS a private in the same battalion. I don't pretend to enjoy the life any more than I could enjov living in a kraal of savages in Central Africa. But that is a matter of no account. I don't propose to return to Durdlebury till the end of the war. I left it as an officer and I'm ru>l coming back as a private soldier. I enclose a cheque for £500. Perhaps Aunt Sophia will be so kind as to use the money — it ought to last some time— for the general upkeep, wages, etc., of Denby Hall. I feel sure she will not refuse me this favour. Give Peggy my love, and tell her I hope she will accept the two-sealer as a parting gift. It will make me happier to know that she is driving it. " / am keeping on as a pied a terre in London the Bloomsbiiry rooms in which I have been living, and I ve written to Peddle to see about making them more comfortable. Please ask anybody who might care to write to address me as 'James M.' and not as 'Marmaduke.' " fJt^KIT''^^i?iH'^ ^'^""^ and shot out her hand for the lett, , which she read eagerly and then pS over to her mother Mrs. Conover began to e^T for hiin!"^ ^' ^°y' '^ ^ ^« ^"'^ than ever cop^?^ni!^'she^d'^^^^^""y- "You're very r«7'^ must knit him some socks," observed Mrs S^ ^^'- ' I h^a^jhose supplied to the kmyTe very .ough and ready." ' fif^ }j !^? f^^ "^ °°e »"^ twopence a day; and I should think he would have the sense to prov^e himself witb adequate underclothing. Also iude! ing from the account of your shopping or^^S don, he has akeady laid in a stoct tfiat woi?d k^t out several Antarctic winters." The Dean tapped his egg gently. "We can cut out slanderous tongues," said he. l.ttli";';!^^ ^^^" "'"''^ calumniating cackle in the Mtle town; nay more: cackle is of geese; there had been venom of the snaWest kind, fhe Deanerv father and mother and daughter, each in thel; several ways, had suffered greatly It is hard to stand up against poisoned ridicule The reasons which guided Marmaduke in the reugnation of his conunission are the concern of nobody. The fact remains that Mr. Marmadioke Irevor resigned his conunission in order to — " "I have a great respect for the Jesuits, my dear," said the Dean, holding out an impressive egg-spoon. Ihe fact remains, in the eyes of the world, as I remarked, that Mr. Marmaduke Trevor of Denby Hall, a man of fortune and high position in the county, resigned his commission in order, for reasons best known to himself, to serve his country more effectively m the humbler ranks of tlie army, and — my dear, this egg is far too full for war time — " with a hazardous plunge of his spoon he had made a yeUow yelky horror of the egg-shell — "and I'm going to proclaim the fact far and wide and — mdeed — rub it in." In the failure of Marmaduke to retain his commission the family honour had not been concerned. Ihe boy had done his best. They blamed not him but the disastrous training that had unfitted him for the commmid of men. They reproached themselves tor theu' haste in throwing him headlong into the fiercest element of the national strueHe towards efficiency. They could have found an easier school, m which he could have learned to do his share creditably in the national work. Many JiP'^^^i?'^" °\ ^'^"" acquaintance, far more capable tnen Marmaduke, were wearing the unifonn of a less strenuous branch of the service. It had been a blunder, a failure, but without loss of honour But when slanderous tongues attacked poor Doeeie for runmng away with a vfilp from little hardship; When a story or two of Doggie's care in the regi- "^t'Si.J:' Durdlebury, highly flavoured in transit and more and mofe poisoned as it went from mouth to mouth; when V legend was soTead abroad that he had holted from SahsW C and was run to earth in a I'urkish bath to^ndr and was only saved from court-martial bvfS mfluence. then the family honour of the ConS was wounded to its proud EngLh depths Zd Jey could say noti^. Th^hJd on& Dogri?^ so, and listened with werbrTbcredSv Tn S'd^?'- ^''^'^r i ^' °°" «°d whSjgoiJg S.ejleSelS ' """"' "''' "''''' ^-• Ihe retort lacked originaUty and conviction, lou cant send it back to him becausp v™, don t know where he is. And whTdiS MTcon- As a result of the quarrel, however, she resumed the weanng of the ring, which she flaunted defiantly with left hand deliberately ungloved. Hitherto she had not been certain of the continuance of the engagement. Marmaduke''' repudiation was definite enough; but it had been dictated by his spnsitive honour. It lay with her to agree or decfine. bhe had passed through wearisome days of doubt. A physically souna fighting man sent about his busmess as being unfit for war does not appear a romantic figure in a girl's eyes. She was bitterly disappomted with Doggie for the sudden withering of her hopes. Had he fulfilled them she could have loved hun whole-heartedly after the simple way of women; for her sex, exhilarated by the barbaiic convulsion of the land, clamoured for something heroic, something, at least, intensely mascuUne, m which she could find feminine exultation. She also felt resentment a I his flight from the Savoy, bis silence and practical disappearance. Although not blaming him unjustly, she failed to realise the spiritual piteousness of this plight. If the war has done any thing in this country, it has saved the young women of the gentler classes, at any rate, from the abyss of sordid and cynical material- ism. Hesitating to announce the rupture of the engagement, she aUowed it to remain in a state of suspended amraaUon and as a symbolic act, ceased to wear the ring. Then Doggie's letter brought comfort and gladness to the Deanery. It rea.ssured them as to his ■ .-r i* sealed the wounded family honour. It justjfied Peggy in playing the game. S>he took the letter round to Dr. Mmdoch's and thrust It into the hand of an astonished Nancy with whom, since the quarrel, she had not been on speaking terms. fnwfT-f "i-r k""* ''f ^^^ ^P •i"« ^hen I've ^Ij^ '«V ^ ^f^^ ^"^^t'^ '" the 10th Wessex.' fc.ee? She withdrew the letter. "Now, what could a man, let alone an honourable gentleman, /To several others, on a triumphant ro-.ad of visits, did she show the vindicating sentence. Anv soft young fool, she asserted, with the directness and not unattractive truculence of her generation can get a commission and muddle through, but it took a man to enlist as a private soldier. man no longer under a cloud. "/( will all come riaht, dear old Oiing," the wrote h iJoggie. It $ a cinch, as the Americant tay. You u oon get used to it — especially if you can realise what It means to me. 'Saving face' has been an awful business. Now U's all over. Of course I'll accept the two-seater. I ve had lessons in driving since you wen^ ««wy-/ W thoughts of ^oing out to France fnii "//^'j??'-^' IS all rot. The engagement stands and all Durdlebury knows ./..." and so on. and so on. She set herself out, honestly. loyaUy. to be the kindest girl in the world to Doggie. Mrs Lonover happened to come into the drawing-room just as she was hcWng the stamp. She thumped it on the envelope with her pahn and. looking round from the wntmg desk against the waU. bowed Her mother a flushed and smiUng face. Doggie kept the letter unopened in his tunic pocket until he could find soUtude in which to read It. Alter mormng parade he wandered to the deserted trench at the end of the camp, where the stuffed sacks, representing (ierman defenders, were Hung lor bayonet practise. It was a noon of grev mist through which the alignments of huts and tents were barely vivible. Instinctively avoiding the wet earth of the parados, he went round, and. tired alter tlie recent spell of physical drill, sat down on the eijuaLy wet sandbam of the model paraoel a patheUc. lonelv little khaki figure, isolitedTo; the moment by the kindly mist from an unoomorehending world. ^ He read Peggy's letter several times. He recognised her goodness, her loyalty. The gratrfSl tears even came to his eyes, and he brushed them away hurriedly rith a swift look round. But his r u-.ju"^ ?°"® ® ''»'«'■• A. long-faded memory ot childhood came back to him in regained colour Some quarrel with Poggy. He remembered also rebuking her priggishly for uninteUigible languace and mincing away. He read the letter again in the hght of this flash of memory. The only difference between it and the childish speech lay in the fact that instead of a declaration of contrasts, she now uttered a declaration of simihtudes. They were both sports." There she was wiong boggie shook his head. In her sense of the word he was not a sport. ' A sport takes chances, plays the game with a smile on his lips. There was no smile on his. He loathed the game with a sickening, shiveriiig loathing. He was engaged in it because a conglomeration of uresistible forces had driven mm into the mSlie. It never occurred to Doegie that he was under orders of his own soul. This siniple yet stupendous fact never occurred to Peggy He sat on the wet sandbags and thought and thought. Though he reproached himself for base ingratitude, the letter did not satisfy him. It left his heart cold. What he sought in it he did not know. It was something he could not find, som&. thing that was not there. The sea mist thickened arouiid him. Peggy seemed very far away. He was still engaged to her — for it would be mon- slroiM to persist in his withdrawal. He must accept the situation which she decreed. He owed that to her loyalty. But how lo continue the correspondence? It was hard enough to write from Salisbury Plain, from here it was well nijth impossiblr. THE regiments of the new armies have gathered into their rank nnd file a mixetl crowd transcending the dreams of Democracy. At one end of the social scale are men of refined minds and gentle nurture, at the other creatures from the slums, with slum minds and morals, and between them the whole social gamut is run. Experience seems to show that neither of the extreme elements tends, in the one case to elevate, or, in the other, t« debase the battalion. Leading the common life, shoiing the common hardships, striving towards common ideals, they inevitably, irresistibly tend to merge themselves in the average. The highest in the scale sink, the lowest rise. The process, so far as the change of soul state is concerned, is inQnitely more to he ainelioration of tbo 1 ■•v,.„st than to the degradation of the highest. 'Ihe one, also, is more real, the other more apparent. In the one case, it is merely the shuffling off of manners, of habits, of prejudices and the assuming of others horribly distasteful or humorously accepted according to temperament; in the other case, it is an enforced education. And all the congeries of human atoms "lat make up the battalion, learn new and precious lessons and acquire new virtues — patience, obedience, courage, endurance. . . . But from the point of view of a decorous tea-party in a cathedral town, the tone — or the standard of manners, or whatever you woidd like by way of definition of that vague and comforting word — the tone of the average is deplorably low. Tlie hooligan may be kicked for excessive foulness; but the rider of the high horse is brutally dragged down into the mire. The curious part of it aU t that, the gutter element being ehmmated altogether, the corporate standard 01 Uie remainmg majority is lower than the standard of each individual. By developing a philosophical disquisition on some such hnes did Phmeas McPhail seA to initiate Doggie mto the weird mysteries of the new social We, Doggie heard with his ears but thought in terms of Durdlebury tea-parties. Nowhere in the mass could he hnd the spiritual oullcck of hh Irish llr k*?- V^'"""- The individuals that may have m disgust. He could not reconcile it with the nobler attributes of the users. It was in vain for Phmeas to plead that he must .accept the lingua franca of the British Army like all other thin/^s I appertammg thereto. Doggie's stomach revolted agaonst most of the other things. The disregard (from his point of view) of personal cleanUness universal m the ranks, filled him with dismay. tven on Sahsburv Plain he had managed to get a little hot water for his morning tub. Hre savo in the officers' quarters, curiously remote inaccessible paradise!— there was not such a thing as a tub m the place, let alone hot water to fill it The men never dreamed of such a thing as a tub. As a matter of fact, they were scrupulously clean according to the lights of the British Tommy; but the hghts were not those of Marmaduke Trevor lie had learned the supreme wisdom of keeping lips closed on such matters and did not complain but all his fastidiousness rebelled. He hated the slmce of head and shoulders with water from a bucket m the raw open air. His hands swell.,' bhstered, and cracJ-.ed; and his nails, once so be,u- grune. Now and then he veut iaio thi town and had a hrt bath; but very fe • of the .11?, s ever seemed to Junk of such a thm,„ The ha it of the British Anny of gomg to bea ii: iu ^lay shirt and underclothes was pecuharly repeUent. Yet Doggie knew that to vary from the sacred ways of his fefiow men was to bring disaster on his head. Some of the men slept under canvas still. But Doggie, fortunately as he reckoned (for he had begun to appreciate fine shades in misery) was put with a dozen others in a ramshackle hut of wBch the woodwork had warped and let in the breezes above below, and all round the sides. Doeeie though dismaUy cold, welcomed the air for obviSus reasons. They were fortunate, too, in having straw paillasses — recently provided when it was discovered that sleeping on badly boarded floors with herce draughts blowing upwards along human spines was strangely fatal to human bodies — but Dcggie found his bed very hard lying. And it smelt sour and sicUy. For nights, in spite of fatigue, jT j"°* ^^^P- ^'^ ^^^^ 8a°K and talked and bandied jests and sarcasms of esoteric meaning, ^me of the recruits from factories or farms satirist their otticers for peculiarities common to their social caste, and gave grotesque imitations of their mode of speech. Doggie wondered but held his peace. The deadly stupidity and weariness of it aUI And when the talk stopped and they settled to sleep, the snorings and mutterings and coughings began and kept poor Doggie awake most of the nigh t. I be uremediable, intimate propinquity with coarse humamty oppressed him. He would have given worlds to go out, even into the pouring rain, and walk about the camp or sleep under a hedge, so long as he could be alone. And he would think longingly of his satin-wood bedroom, with its luxurious bed and lavender-scented sheets, and of lus beloved peacock and ivory room and its pictures and exquisite furniture and the great fire roarine up the chunney, and devise intricate tortures for the Kaiser who had dragged him down to this squalour. offended his dehcate senses. Nor could he watch wi th equanmuty an honest soul pick his teeth with his httle finger. But Doggie knew that acquiescence was the way of happiness and protest the way of At first he made few acquaintances beyond those with whom he was intimately associated. It seemed more politic to obey his in. .incts and remain unobtrusive in company and drift away inoffensively when the chance occurred. One of the men with whom he talked occasionally was a red-headed httie cockney by the name of Shendish. For some reason or other — perhaps because his name conveyed a perfectly wrong suggestion of the Hebraic — he was always called "Mo^' Shendish. Don t yer wish yer was back, mate.»" he asked one day havmg waited to speak tiU Doggie had addressed and stamped a letter which he was writins at the end of the canteen table. •ij?^^' f^®^* ,'°"'^- ^° *>« family castle, where glided footmen anas sausage and mash about on rays and quarts of beer all day long. I do." Mo Shendisli grinned. He showed little yellow teeth beneath a little red moustache, c/ ^^«,'^ got one," said he. "It's in Mare Street, ilackney. I wish I was there now." I was making my thirty bob a week regular. I was m the fish business, I was. And now I'm serving my ruddy country at one and twopence a daif. Not the same as sitting in a snug oriis all day with a pen in your lilywhite 'and, and going 'ome to your igh tea in a top 'at. What made you join "Same 'ere," said Mo; "only I couldn't put it into such '"ancy language. First my pals went out one after the other. Then the gels began to look saucy ; t me, ai!d at last one particular bit of skut what I'd been walkmg out with, took to promenadmg with a blighter in khaki. It'd have been silly of me to go and knock his 'ead off, so I enlisted. And It s all right now." ness of mvention. "I've got her photograph," Shendish confided in a whisper mid kid his hand on his tunic pocket. Ihen he looked round at the half-filled canteen to see that he was unobserved. "You won't give me away if I show it yer, will yer? " e -= '"c Doggie swore secrecy. The photograph of Aireie an angular, square-browed damsel, who look^^as Uiough she could gmde the most recalcitrant of fishmongers into the paths of duty, was produced and thrust mto Doggie's hand. He ins^cted it ri? ?«^tf. appreciation, while his red-headed friend regarded hun with fatuous anxiety. Fair hair and blue eyes," said Shendish. f.Z^fi ^^ question, half idle yet unconsciously tactM, was one of those human things which cost fTien?for%"' '"'''^ ^ '°"''^- '' ^ave Doggie a "Mo," said he, a day or two later, "you're such a feSuIger^' ^ ^'^ ^°" "^ sic/abon^'aSle "Gawd knows," smiled Mo, unabashed. "I suppose It's friendly like." He wrinkled hh brow m iJiought for an mstant. "That's where I think you re making a mistake, old pal, if you don't mind J^L^ i'^'T^- ^ ^°^ ^^«t y^ "e, but the others don t. You're not friendly enough. See whatlmean^ Supposin' you say as\ou wfdd inl city rcstoo-ang when you're 'aving yer lunch. ct !i ^If .'""'"J^ P^ ™« •»« salt?' -well, that's stand-offish -they say 'Come off iti' But if you look about and say, 'Where's the b. . y salt?' hat^u™^ ^" """^^ understand. They chuck cuft^^ ^°«g'«' "It's very — I mean b. . .y — diffi- So he tried to be friendly; and if he met with no great positive success, he at least escaped animosity In his spare time he mooned about by himself, shv disgusted, and miserable. Once, when a fToup of men were kicking a football about, the baU rolled his way. Instead of kicking it back to the expectant players, he picked it up and advanced to the nearest man and handed it to him poUtely. He turned away without waiting for a reply. At drills things were easier than on Salisbury Flam his actions being veiled in the obscurity of sijuad or platoon or company. Many others besides iumseU were cursed by sergeants and rated by subalterns and drastically entreated by captains. He had the consolation of community m suffering As a trembhng officer he had been the only one the only one marked and labelled as a freak part the only one stuck in the eternal pillory. Here were fools and incapables even w .j dull and infective than he. A ploughboy feUow-recruit from JJorsetshire, Pugsley by name, did not know right from left, and having mastered the art of fomung lours, could not get into his brain the reveree process ol tormmg front. He wept under the lash of the corporals tongue, and to Dog<ne these t«ars were healing dews of Heaven's disSlation. By degrees he learned the many arts of war as taught to the pnvate soldier in England. He could r^^ frS shutting his eyes when he pressed tlie triwer S his rifle, but to the end of iL career his shootinJ was en-atic. He could perform with Ihe weaSf the other tncks of precision. Uneucun^er^i^e could march with the best. The torZ^^ the heavy pack nearly killed him; but m time as Ws muscles developed, he was able to slog atong Zdll the burden. He even learned to dii That w^ the worst and most back-breaking art of all would get together and walk into the Me Sde toZk ^t'^"^ "l''^'^^ ^'«^°°' «"^ there wStle to look at save the deserted shops and the squafl! fretted pier and the maidens of the place, who usuX were m company with lads in kiaU. Sometimes glance of shy invitation, for Doggie in his short hSelf^'Sl.r'/^* "• »^«d>'^n\|^feUow, carjtog hunself weU and wearmg his uniform with instinctive grace. But the dai^sel ogled in vaL " W-hf r"^ "^'^asion Phineas burst into a gufl^aw. vVhy don t you talk to the poor body? She's a respectable girl enough. Whereas the haAn? " l^p square-pushing'?" said Dogsiu contemntuoudy, usmg the soldiers' slang for walki^7ab^P^ vilh a young woman. "No, thank you." * '"'""'^ And why not? I'm not counseUing you, laddie Then he said: "A thing I can't understand is this mania for pickmg up girls — just to walk about the streets with them. It's so inane. It's a disease." "Did you evei consider," said Phineas, "how in a station less exalted than that which you used to adorn, the young of opposite sexes manage to meet, select and marry? "Confound Dm-dlebury!" said Doggie. Phineas checked him with one hand and waved the other towards a hostelry on the other side of the street. "If you will give me the money in advance, so as to evade the ungenerous spirit of the no-treating law, you can stand me a quart of ale at the Crown and Sceptre and join me in drinkmg to its confusion." So they entered the saloon bar of the public house, and Doggie drank a glass of beer while Phineas swallowed a couple of pints. Two or n ^1.?'^^'' S'^'diers were there, in whose artless talk McPhad joined lustUy. Doggie, unobtrusive at the end of the bar, maintained a desultory and uncomfortable conversation with the barmaid, who was of the florid and hearty type, about the weather, borne days later, McPhail again made allusion to Durdlebury. Doggie again confounded it. I don t want to hear of it or think of it," he exclaimed, m his nervous way, "urtil this filthy horror is over. They want me to get leave and go down Md stay. They're making my life miserable with kmdness. I wish they'd let me alone. They StItL" " Me?h d^H,^' ^ bookstaffat'CVK ^^ !l "■ 1 • ?" huddled up near him, their heads on their kit bags, slept anS snored. DoS^ataoS On^thTF Pf" ^'^ '^"'^ ^^ h«t^«J ofTe Sf On the East coa.t much the same hfe as 01^6 South, save that the wind, as if Hun-sent foimd Its way more savagely to the skin. ' ^'^ n^'^\ V^^ J"®"' .«^«y «n Jeave. The gladiZJ'i: "^'^ ^^ welcomed their return showwl Doggie how great a part they played in his new K-.u^° " i^l °'" ° 'ey vroulcTdepart God knew whither and he would be left in dreadful to^lbej Though him l^e tw. men, the sentimental cXfy S^°Zk ??"* 'i'7f''^^ ^'"''"^te of Gla^ow ^l .X"°",^^^.' '^«' ^«««me friends. He swnt with them all his leisure time. ^ MrPhrnT f -1^ f^y tragi-comedies of life occurred. McPhaU got drunk m the crowded bar of a UtUe pubhc house in the village. It was the last j^ssMe drmk together of the draft and their pal^ T^e draft was to entrain before daybreak on the moirow MnP^-i ™h: suig^g. shouting khaki throng. McPhail, who had borrowed ten pouHds from Doggii wT /u.TJ'i!? ^^P"?" "•« hardships of the front, estabhshed bmself cfose by the bar^d was cbmkmg whisky. He was also distributing sT reptitious sucpences and shiUings into eager hands ri t '"''n'^ convert them into alcohol for eager tbroate. Dcwgie, anxious, stood by his side. The mounted to his unaccustomed brain. He beeM to hector, and, mu,.er of picturesque speech, he coinpeUed an adnuring audiW. Boggie did not reahse the extent of his drunkenness untU, vamitS himself as a Scot and therefore the salt of tie aZf he pick^ a quarrel with a stolid Hampshire giait who professed to have no use for Phineas's feUowcountrymen. The men closed. Suddenly someone shouted from the doorway on the bar counter and demanded another whisky He was about U> lift the glass to his lip^ when Domie teiTined as to wbit might happen, knoclied the gfas^ out of his hand. " „,.^i}^fa\^«s very drunk. Little blinking Marmaduke Doggie Trevor. Little Doggie Trevor whom I trained up from infancy in the wav he sliouldn t go — ' forgive him. He doesn't like being caUed Doeeie rii u i-''?"°T:"° Pred'lex'n to be called an ms. 1 11 be thinking I m going just to strangle him." He struck out his bony claws towards the shrinking Doggie; but stout arms closed round him and a horny hand was ciamped over his mouth, and thev got hun through the bar and the back parlour into the ywd, where they pumped water on his head. And when the A. P- M. and his satellites passed by, the qmet of The Whip m Hand was the holy peace of a nunnery. '' ^'^'-'^ Doggie and Mo Shendish and a few other staunch souls got McPhail back to quarters without much trouble On parting, the delinquent, semi-sobered, shook Doggie by the hand and smiled with an ai^ ot great affection. when you knocked the glass out of my hand I thought you were in danger of losing your good manners m the army. Well have many a pow-wow together when you loin me out there." The matter would have drifted out of Doggie's mind as one of no importance, had not the detested appellation by which Phineas hailed liim struck the miaginalion of his conu'ades. It filled a long-felt want, no nickname for Private J. M. Trevor having yet been invented. Doggie Trevor he was and Doggie Trevor he remained for the rest of his period of service. He resigned himself to the inevitable. The stiu^ had gone out of the name through his comrades ignorance of its origin. But he loathed it as much as ever; it sounded in his ears an everlasting reproach. In spite of the ill turn done in drunkenness, Doggie missed McPhail. He missed Mo Shendish, his more constant companion, even more. Their place was in some degree taken, or rather usurped. Tor it was without Doggie's volition, by "Tafiy" Jones, once clerk to a firm of outside bookmakers. As Doggie had never seen a race-course, had never made a bet, and was entirely ignorant of the names even of famous Derby winners, Taffy regarded him as an astonishing freak worth the attention of a student of human nature. He began to cultivate Doggie's virgin mind by aid of reminiscence, and of such racmg news as was to be found in the Sportsman. He was a garrulous person and Doggie a good listener. To please him Doggie backed horses, through the old firm, for small sums. The fact of his being a man of large independent means both he and Phineas (to his credit) had kept a close secret, his clerkly origm divined and promulgated by Mo Shendish being unquestioningly accepted, so the hets proposed by Taffy were of a modest nature. Once he brought off a forty to one chance. Taffy rushed to hup with the news, dancing with excitement. Doggie's stoical indilFerence to the wbS^S of twenty pounds, a year's army pay gavH^ cause for great wonder. As Dog^e XW^ smSS equanimity when he lost, Taffy \|ut hi^ dlwHs" ^ZXT^- ""^ '^^^ 'to^admire'^Sr t^ This friendship with Taffy is worth special record for It was mdirectly the cause of a little revoS m Doggies regimental life. Taffy was an earnest hough indifferent performer on tL l^imy Se It was his constant companion, the soTace of iS leisure momenU and one of the minor tortu^es^ Dc^gie's existence. His version of the WarS,2 was peculiarly excruciating. '»un,eiuai»e raw by the false notes and maddenintr intervals ^If ^rtK T ""i^, ^^"•1 «°d began ?o ^lay W S ;„t w^"^' ^J^i^king morbidl/from L/ fom of notoriety, he had shown no si^ of mST comi)li8hment. But to-day the musiciaS^SiJ^ w^rro'L^-'VTT"- n^^" '^^ BtoppKe^ W ^ i^- ..-^'^ .?,"' doggie went on. Thev kept him whisthng till the hut was crowded ^ 1 henceforward he was penny-whistler bv exceUence to the battalion.^ He whistled hL^ff into qmte a useful popularity aaaaeu YY said the Dean. ' ' "I think you're ju8t splendid," said Peifjrv. They were sitting in Doggie's rooms in Wobuni Mace. Doggie having been given his three days' leave before going to France. Once again Durdlebury had come to Doggie and not Doggie to Durdlebury. Aunt Sophia, however, somewhat ailing, had stayed at home. " Doggie stood awkwardly before them, conscious of swollen hands and broken naUs, shapeless ammumtion boots and il -fitting slacks, morbidly conscious, too, ot his original failure. "You're about ten inches more round the chest than you were, said the Dean admiringly. And the picture of health," cried Peggy. For aiiyone who has a sound coiistituUon," answered Doggie, " it is quite a healthy life." "What none of us can -juite understand, my dear feUow, said the Dean, "is your shying at Durdlebury. As we have written you, everybody's singing your praises. Not a soul but would have riven you a heart' welcome." "Besides Peggy chimed in, "you needn't have made an exh-hition of yourself in the io« if vou didnt want to. The poor Peddles are woefuUy disappomted. ' hZ.,,fitTu '™™. tfe Peddles, Uiere^s your own beautaf,^ house waiUng for vou. It seems^so i^y l^pS^" ' "^^"^ o/ moping in these C? of Sw "' f h^n^ ^^ ^ ^^ «»° at point ol view, the Dean admitted. "A solution of «.ntmmty IS never quite without its dangers Fv°n Ohver confessed as much." "^"b, even 1 didn t think Marmaduke would be interested " said Peggy quicUy. "He and OhVer have n^;r been what you might caU bosom friends." deal of fightmg, and had one or two narrow esclpes. Was he keen to get back?" asked Doggie. ^ ™Jrl T,,^"?^^^- "' instanced his c£se in mv remits on the dangm of the solution of continSt^^ The Dean, urbanely indulgent, joined his fingertips together and smiled. '""Peggy is right," said be, although I don't wholly approve of her modem lack of reticence in metaphor. Oliver is coming out true gold from the fire. He's a capital feUow, And he spoke of you, my dear Marmaduke, in the kuidest way in the world. He has a tremendous admiration for your pluck." Presently tlie Dean, good, tactful man, discovered that he must go out and have a presci^ption made up at a chemist's. That arch-Hun enemy the ^^ "I quite imderstand, dear old thing," she said. "I know the resignation and the rest of it hurt you awfully. It hurt me. But it's no use grousing over spilt milk. There are thousands of gentlemen in the ranks. Besides —you'll work your way up and they'll offeryou another commission in no time." ^^ "You're very good and sweet, dear," said Doggie, to have such faith in me. But I've had a year — " "A yearl" cried Peggy. "Good Lord! so it is." bne counted on her fingers. "Not quite. But eleven months. It's eleven months smce I've seen you. Do you reaUse that? The war has put a stop to time. It is just one endless day." Peggy intemipted with a laugh. "You must be a wonder. Dad's always preaching about seS^ knowledge. TeU me all about it." UiP^^^I ^^^ ^ ^f^^' « ^^ same time passinit cried^ over 't m a familiar gesture. Then P^ him r."^ McPhail, careful godfather, who had taken s^hS I T""J " ^^ regimental barber and pr^ scnbed a transformation from the sleek long tair bn«hed back over the head to a conventional military crop with a rudiment of a side parting. On hair'iif «f™«'" Doggie repUed, "for a Tommy's hau- to be cut as short as possible. The Germtms are sheared like convicts." ^^ vrermans wl'/^re"^'"'* ^® ? commission," said he, "if the War Office went mad and sank on its knees Mid b^? Its head m the dust before me." .! J? heaven's name, why not?" on Its head. Everything's upside down It ih^ no sort of use for M^WukeTevOT of D^nbv hSi No more use than for Goliath. By tS wafK the poor htUe beast getting on?" ^' ^ for the glory of old England. "Good luck," cried Peggy from the window, bhe blew hmi a kiss. The taxi drove off and Doggie went back into the house with leaden feet. The raeetmg, which he had morbidly dreaded, had brought bun no comfort. It had not removed the mvisible barrier between Peggy and himself. But Peggy seemed so unconscious of it that he began to wonder whether it only existed in his (hseased unagmation. Though by his silences and reser he had given her cause for resentment and reproai her attitude was nothing less than angehc. He sat down moodily in an armchair, his hands deep m his trousers pockets and his legs stretched out. The fault lay in himself, he argued. What was the matter with him? He seemed to have lost all human feeling, Uke the man with the stone heart in the old legend. Otherwise why had he felt no prick of jealousy at Peggy's admiring comprehension of Ohver? Of course he loved her. Of course he wanted to mairy her when this nightmare was over. That went without saying. But why couldn't he look to the glowing future? A poet had called a lovers mistress "the lode-star ca his one de-sirp." Tlat to hun Peggy ought to be. Lode-star. One desire. The words confused him. He had no iX star. His one desire was to be left alone. Without petSLcUor ""^"^ ^""" ^""^ P«^^ ^^^^^ Doggie was no psychologist. He had never ac^ired the habit oftumingVnself inside ou? and gloatmg over the horrid spectacle. All his life he S^r,i» tK T^^^ ^^^ "^^^ «™P'e motives and a t^£ R°y^^ ^""^^^ ^^ «t^dard tc measure tnem. But now his soul was knocked into a Si^'^^ "' complexity, and his poor little standards were no manner of use. He sSV himself as m a glass darkly mystified by imknown change. He rose, sighed, shook hunsefr. I give it up," said he, and went to bed. Tf^L ^•■«°'=%<='««? s^ept and gamishea for war. a France, f-ave for the ubVuitous English soldiery of silent towns and empty villages ^and S2d roads; a France of smiling fiel,fc -^ so^wM faces of women and drawn, patient faces of old men -and even then, the women and old men were Zt.'f^ ^^^^^' ^" "^^y ^«'« «t work onX land, sohtary figures on the landscape, with vast spaces between them. In the quiet toVliships eT iltJlft •^'^,^'.?'="<^^ conflicted with thehsense of being m friendly provincial France, and gave the mipression of fore^ delation. Fot beS that long gnm Ime ofetemal thunder, away over there m the distance, which was caUed the Fron? s rest signs and placards in yet another alien toZe also outraged tie serene genius of French urC we. Yet our signs were a symbol <rf a mightv Empire s broUierhood and the dimmed eyes that beheld the Place de la Fontaine tranrformS Sto Holbom Circus" and the Grande Rue into "Piccadilly, smiled, and the owners with eager courtesy dmscted the stray Tommy to "Regent Street'' which they had known all their life as the Rue Feudlemaimil — a word which Tommy could not remember, still less pronounce. It was as much as Tommy could do to get hold of an approximation to the name of the town. And besides these renamings, other inscriptions flamed about the streets; aJph^etical hieroglyphs in which the mystic letters H. Q. most often appeared; "This way to the X. M. C. A. hut ; in many humble windows the startling announcement, "Washing done here." Bntish motor lorries and ambulances crowding Uie htUe Place and aligned along the avenues, iiritish faces, British voices, everywhere. The blue uniform and blue hehnet of a French soldier seemed as inconmious though as welcome as in London. And the straight, endless roads, so French with then- mfimte border of poplars, their patient little stones marking every hundred metres until the tenth rose into the proud kilometre stone proclaimmg the distance to the next stately town, rang too with the sound of British voices, and the tramp of Briti^ feet and the clatter of British transport, and the screech and whirr of cars, revealing as they passed the flash of red and gold of the British staff. Yet the finely cultivated land remained to show that It was France; and the little whitewashed ^^ages; the cur6 in shovel hat and rusty cassock; the children in blue or black blouses, who stared as Uie British troops went by; the patient, elderly Temtonals in their old pre-war uniforms, guarding unttoeatened culverts or repairing the roads; the helpful signs set up in happier days by the Tourmg Club of France. He had loathed the East Coast camp^ When he iMided at Boulogne in the darii and pouring ram, and hunched his pack with the others who wOTt off smgmg to the rest camp, he regretted East be OTowIed, stimibling over the raib of the quay. liim ^°" ^'^ ^°"°^ """'" ^^ *** ™^ °®^ But Doggie did not trouble to repb', his neighbour bemg only a private like himself. ' Then the draft joined its unit. In his youth iJoggie had often wondered at the meaning of the lamihM- mscnption on every goods-van in France: 40 Homines. 8 Chevaux.^' Now he ceased to wonder. He was one of the forty men. ... At the rail-head he began to march and at last joined the remnant of his battalion. They had been through hard fighting and were now in biUets. ^°t J ^"^^ ^®™' ^® ^^ °<* realised the drain there had been on the reserves at home. Very many familiar faces of officers were missing. New men had taken their place. And very many of hw old comrades had gone, some to Bhghty, some West of that Island of Desire; and those who remained had the eyes of children who had passed through the Valley of the Shadow of Death. McPhail and Mo Shendish had passed through unscathed. In the reconstruction of the regiment chance willed that the three of them found themselves m the same platoon of A Company. Doggie ahnost embraced them when they met. ■aying, laddie, I'U not deny that I've derived conndwable interest and amusement from a bombardment. Yet it has its sad aspect." He paused for a moment or two. "Man." he continued, what an awful waste of money I " m'«°°1V^?^. ^"' °'1 Mac is jawing about," said Mo Shendish, "but you can take it from me he 8 a holy terror with the bayonet. One moment „f "^"T!?' ^'***?'" ^^?^^ Phineas, the picture l^^^i^"^ T?t^y- ^'J «» lias our ironP — 1 would have said steel-inviscerated, but He wouldn t understand it — comrade by my side." Mo Shendish, hehneled, browned, dned, toughened, a very different Mo from the pallid fewet whom Aggie had driven into the ranks of war Hunched hunself up, his hands clasping his knees. ' «™.\i '.V™™** ^8"^ '• ^^'^^ you're 80 excited you don t know where you are," said he, "but I don t hke thmking of it afterwards. " As a matter of fact he had only once got home with the bayonet, and the memory was very unpleasant. But you ve lust thought of it," said Phineas. all/eilL.''" "^' "^^ ^" "'^"* -^"It's astonishing," Phineas remarked sententiously, how many people not only refuse to catch pleasure as it flies, but spurn it when it sits up Md bM8 at them. Laddie," he turned to Uoggie, the more one waUows in Hedonism, the more one reabses its uiiplumbed depths." A httle girl of ten, neatly pig-taUed but piteously "Approach, my little one,'' Phineas cried in French words but with the accent of Sauchiehall ^••,.. " ^ ^ave you a franc, what would you do with It? ' " Lend me a franc, laddie," said McPhail. and when Doggie had slipped the coin into his pahn, he addTMsed the child m uninteUigible grandiloquence and sent her on her way mystified but rejoicing! Cm bonsdr6lesd' Anglais! "Ah, laddie," cned Phineas, stretching himself out comfortably by the lintel of the door. "You've got to learn to savour the exquisite pleasure of a genmnely kindly act." PERHAPS one of the greatest influences which transformed Doggie into a fairly efficient though undistinguished infantry-man was a morbid social terror of his officers. It saved him t^T^fT/it «T'"'^'?' "°^ fr°™ "nany « heart to heart talk wherem the zealous lieutenant gets to know his men. He lived in dread lest military delmquence or civil accompUshment should be the means of revea'vig the dis^ace which bit Uke an acid mto his soul. His undVisable air of superior breedmg could not fail to attract notice, bften his officers asked him what he was in civil- life. His reply "A clerk, sir," had to satisfy them. He had developed a cunous self-protective facultv of S H^'^n'^ "P ^^ ''•^««^«8 «t the approach hL ^u- ?°f^ * ^T^ subaltern had Elected mm as his batman; but Doggie's agonised "'^ ^^^ be awfully good of you, % if yfu didn't" mmd not^ thinking of it," and the appeal in his eyes estabhshed Uie freemasonry of caste ^d saved hi^frpm dreaded inUmato relations. pfi; "hi! '•!^"l'^ '^"«'« that forlSd^hL Platoon. It braced hun to the performance^ hideous tasks; it restrained him fcm ™si3^ of sui^nor intellectual power or artis?™ caSt? m world upheaval had thrown him from Cpe^: not the average young Englishman of comfortable pMiUon who Ead toyed with aesthetic supeS! ties as an mnusement, but a poor little by-product «' <''?'«tered life who had bien^ brought up from Fnn^H ^''"'''^; ?°^ *«y^ «°; f°" days ofi? l-our days on of mwery inconceivable. Four days on, during which the oflrcers watched the mea with the unwavermg vigilance of kindly cats. Dam sight more than I ami" laughed the subaltern and with a cheery nod in acknowledgment of DMgje s salute, splashed down the muddy trench, but Doggie was chilled to the bone, and he had no feehng m his feet which were under six mches of water, and his woollen gloves, being wet "through, were useless, and prevented his numbed handi from feehng the sandbags with which he and threst of the platoon were repairing the parapet; for the C-ermans had just consecrated an hour's general bate to the vicmity of the trench, and its exquisite symmetry, the pride of the platoon commlnder had been disturbed. There had also been a feW ghastly casualties. A shell had fallen and burst SwM^^I'^vflS ^^,f ^f ^J"^ °^ the trench. In a stui>efied wly he found hunself minglmg with others who wer« engaged in cleanng up the horror. A murmur reached him tiiat it was Taffy Jones who had then been dismembered ... The bombardment over, he had taken his place with the rest in the reparation of the parapet; and as he happened to £e at ??if°^ 5 u '""i- ^^ °®<=^'" »«d spoken to him. If he had been suffenng tortures unknown to Attila and unimagmed by his successors, he would have answered just the same. nf Tti"S^^ somewhat hysterically, for the fate of Taffy had unstruiut him for thp tim^ Dkcontemplated the l^iTdSj, n^oTditl'^?^ Its planks half swimming on filthvldH ifj • from "tS'^B.r °^ P"f"^' ditch^lhaVZtS irom Uie Belgian coast to Switzerland, the clavcovered, shapeless figures of men, th^ir Mows alm^^^^distmguishable even by' featur^Xm „l^l ^^ ^««' 'ome upon me lately," said Phineas that patnotism is an amazing virtue " ^'^^a' Doggie drew a foot ou. of the mud so as to find a le^ precarious purchase higher up the do^ "th^^Fr^t?^™"'^ imagination," said Phineas, tiMi a Free Kn-k precentor in Kirkcudbright." But 18 It patnotism?" Doggie nersiat^l "it I thought it was. I should beTfppie^ Ke had orders to go over the top and attack and Fco^d fi ofr^^/"' «^«''' «°d lo«e myself just i^Se lend for itself. And so had poor Taffjr Jones. And I have a bonHy Scottish thiret, the poignancy of which both of you have been happily spared. I will leave you, feddie to seek in slumber a surcease from martyrdom." After one of the spells in the trenches, the worst he had expenenced, A Company was marched j-jto new billets some nules below the lines, in the once prosperous village of Fr^lus. They had slouched a^ong dead tired, drooping under their packs, sodden with mud and sleeplessness, silent, with not a note of a song among them -but at the entrance to the village, qmckened by a word or two of exhortation Irom officers and sergeants, they pulled themselves together andmarch^ m, heads up, forward, in fault1^ step. The G. 0. was jealous of the honour of vJfio^f^" A^^ assumed that his predecessors m the village had been a "rotten lot," and was determined to show the mhabitants of Fr^lus what a crack Jinghsh regunent was really Uke. Fr61us was an unimportant, uidieard of village; but the opinion of a thousand Freluses made up France's oninion of^e Bnti^ Army. Doggie, although haft stupefied with fatigue, responded to the senthnent, hke the rest. He was conscious of making part of a gaUant show It was only when theyhSt&d stood easy that he lost count of things. The wide mam street of the village swam characterless before his eyes He followed, not directions, but directed men, with a sheephke mstmct, and found hunself stumbhng through an archway down a narrow path. He had a dim consciousness of lurching sideways and coirfuse(Uy apologismg to a woman who supported him back to equilibrium. Then the nert thing he saw was a bam fuU of fresh straw, and when somebody pomted to a vacant strip, he feU down, with many others, and went to sleep. ; indicating the name and pursuiV^of the teifant^ with here and there, too, long, whitewashed^L' encl,^in. a daii^ or a timber y WreSll'S nlt^^^^ ^^ ^^^ ,™«'^' ^d the village gradu^v PIOUS onermgs. At open doors the Lritish soldipro h^le'w' ri"^ ^^ ^"^ interiot bJSnd tnem tne torms of the women of the house hlii« aproned, moved to and fro. The early^TemS was warm, a westerly breeze deadened the sound of the distant bombardment to an unheeded drone, and a holy peace settled over the place. Doggie, clean, refreshed, comfortably drowsy, having explored the village, retmned to his billet, and looking at it from the opposite side of the way, for the first time reaUsed its nature. The lane into which he had stumbled the night before ran under an archway supporting some kind of overhead chamber, and separated the dwelling house from a a warehouse wall on which vast letters proclaimed the fact that Veuve Moiia et Fils carried on therein ^e busmess of hay and com dealers. Hence, Doggie reflected, the fresh, deep straw on which he and his fortunate comrades had wallowed. The double gate under the archway was held back bjr uon stancheons. The two-storied house looked fajrly large and comfortable. The front door stood wide open, giving the view of a neat, stiff Uttle hall or hvmg-room. An article of furniture caught his idle eye. He crossed the road in order to have a nearer view. It was a huge, pohshed mahogany cask standmg about four feet high, bound with shimng brass bands, such as he remembered having seen once in Brittany. He advanced still closer, and suddenly the slim- dark girl appeared and stood m the doorway and looked frankly and somewhat rebukmgly into his inquisitive eyes. Doggie flushed as one caught in an unmannerly act. A crying fault of the British Army is that it prescribes for the rank and file no form of polite recognition of the existence of civilians. It is contrary to Army Ordei to salute or to take off theu- caps. They can only jprk their heads and grin, a gauche proceeding which e laces them at a disadvantage with the fair sex. »oggie, therefore, sketched a vague salutation halfway between a salute and a bow, and began a profuse apology. Mademoiselle must pardon his An amused light came into her sombre eves and a smile flickered round her lips. Dogrie noted in stantly how pale she was, anfhow ^?, fdSt litUe Ma/s oui, maw ouif" she cried. ^'They are all chanmng. lis spnt doux comme des moutoL BvTt Sfat^." '^'''''° "^ delicacy -somewhat exajsaid Do/^ °^ ^°"' MademoiseUe. to forgive me." ci,®L^ ^^ ™'f °f P'''^^^ intercourse, either Dogrie should have made his bow and exit, or the mdl^ exercising her prerogative, should have givThS the opportunity of graceful withdrawal. But tS remamed where they were, the girl framed bv the iT""!?',^" "^^ ^>« fi8"« in khalHnd hch^! teZfti^^Hp'^' "P ^" ^^' ^-- ^« ^-'" Mademoiselle moved aside and Doggie entCTed takmg off his helmet and holding it mider his arm like an opera-hat. There was nothing much to see m the httle vestibule-parlour: a stiff, tasseUed cnair or two, a great old linen press, taking up most of one side of a wall, a cheap table covered with a chenille tablecloth, and the resplendent old cask, about which he hngered. He mentioned Brittany Her tranc face lighted up again. Monsieur was right. Her aunt, Madame Morin, was Breton, and had brought the cask with her as part of her dowry, together with the press and other furmture. Doggie aUuded to the vastly lettered mscnption, "Veuve Morm et Fils." Madame Morin was, m a sense, his hostess? And the son? Alas, Monsieur!" mvahd. She has been in bed for the last three "Then what becomes of the busmess?" It IS I Monsieur, who am the business. And I know nothmg about it." She sighed. Then with her blue apron — otherwise she was dressed in unreheved black --she rubbed an imaginary speck Irom the brass banding of the cask. "Tim I suppose you know, was for the best brandy. Monsieur. ' ■""" They were at the door. He looked out and drew back. A luiot of men were gathered by the gate of the yard. Apparently she had seen them too. for a flush rose to her pale cheeks. MademoiseUe," said Doggie, "I should like to creep back to the bam and sleep. If I pass my comrades they'll want to detain me." She led him through a room and a passage to the kitchen. They shared a pleasurable sense of adventure and secrecy. At the kitchen door she paused and spoke to an old woman chopping up vegetables. Toinette, let Monsieur pass." To Doggie she said: Au revoir, Monsieur' and disappearwl. ITie old woman looked at him at first with disfavour. She did not hold with Tommies needlessly tramping over the clean flags of her kitchen. But IJoggies pohte apology for disturbing her, and a youthful ^ace of manner — he stiUteld his tin- "France— a/i.' la pauvre Francel" She sighed, drew a wisp of what had been a comet of snufif from her pocket, opened it, dipped in a tentative finger and thumb and, finding it empty, gazed at it with disappointment, sighed again, and with the methodical hopelessness of age folded it up into the neatest of Dttle squares and thrust it back in her podtet Then she went on with her vegetables. Doggie took his leave and emerged mto the yard. He dozed pleasantly on the straw of the bam, but It was not the dead sleep of the night. Bits of his recent little adventure fitted into the semi-conscious intervals. He heard the girl's voice saying so gently: "Pauvre gargon!" and it was very comforting. He was finally aroused by Phineas and Mo ShendMh, who, having slept like tired dogs some distance off down the barn, now desired his company for a stroll round the village. Doggie good-naturedly assented. As they passed the house door he cast a quick glance. It was open, >M'.t the slim figure in black with the blue apron was not visible within. The shining cask, however, seemed to smile a friendly greeting. .. " W you believed the London papers," said Phineas, youd thin.' that the war-wom soldier coming from the trenches is met behind the lines with lu»mous Turkish baths, comfortable warm canteens, amd Picture Palaces and theatrical entertainments. Can you perceive here any of those amenities of modem warfare? " «j».I?'l ™?.n° ?,®. P'^' « Brighton,'" sang Mo Shendish. "But I'd sooner have Mwrit ot Ymmouth any day Brighton's too toffish V whelS. My I and cocUesI T wonder whether we shaS ^er eat 'em again." A far-away, dreamt S crept mto ins eyes. ' anpeared there had been an altercation over right L^°"^A^^-^ ^^y^^'^^t vendor in which7to ^?Yn^/±^K'°"' ^-^ h"^ «"°« off triumphant mv^? T^ u^ ^'T'r^.. being in the fishVade myself, I could spot the winners. Oi^^^TTf "* «>T?'"'i ^ « confidence of tbe i^^nlS^^^^^"' ^M^^ that the landlady being m m bed and the place run by a young girl, the ho^ had been purposely missed. Doggie drlw a brealhof T^ey stroUed on and came to a forlorn little Debit ae I abac, showing in its small window some clav pipes and a few flyblown picture postcards. Now Uoggie. m spite of his training in adversity, had never resij^ed himself to "Woodbines" and other such brands supplied to the British Army, and Egyptian and Turkish beinsr beyond his social pale ^l- ^l^??*** ^"o'^'ng French Regie tobacco, of jhich he laid m a stock whenever he had the chance, ho now he entered the shop, leaving Phineas and Mo outeide. As they looked on French cigarettes wiUi sturdy British contempt, they were not interested in Doggie s purchases. A wan girl of thirteen rose from behind the counter. Vous desirez. Monsieur?" Doggie stated his desire. The girl was calculating the pnce of the packets before wrapping them up^ when his eyes feU upon a neat little pfle of cornets m f/r ''%".u^^ ^^''\ '^^^y '^'^^'^"y suggested to him one of the great luminous ideas of £& Ufe It was only afterwards tbat he realised its effulgence, l-or the moment he was merely concerned widi the needs of a poor old woman who had sighed lamentably over an empty paper of comfort. Do you sell snuff? f».^i.¥ '^5'^''* * ^?" package, enough to set the whole village sneezing to the end of the war and peering round the tiny shop and espying in the recess^ of a glass case a Uttle oWwood bol, orm^^ ™frl <^°^^°? ^i^^n^^ ^'^ forget-me-nots, purchased that also. He had just paid when iik companions put their heads in 'the dwrwly £ i~>t ff '' i.*"?^ ?^ ^« regiment whom I have to look after and feed with pap," said Doggie "and bemg hun^y, he is b^ging^ou not to de^Tn 'me/^'' esSish'S hS.0^ ''^ ''^ "«'^ ^"-' -<• ^It was late that evening before Doggie could find an opportumty of slippTnp, unobserved, through the open door into the house Wtchen dimly illuminated by an oil lamp. Ihen he became aware of the adjacent forms and stenng eyes of Phmeas and Mo, who for the first time m their mihtary career beheld him on easy terms with a strwige and prepossessing young woman. After a seconds thought "he came to a diplomatic decision. MademoiseUe, • said he in his best Durdlebury ^T^: r ™"J '• ^T 1° P^«^"t "^y two comrades, . M^oilSS.^^ '"'^°°' """"^'^ ^^P^«^- somelw'^t^^'? ^T^ * ^^^^ ^P^"^ ^°^' and then somewhat mahciously addressing McPhail, as the biMer and the elder of the two. - «« uie "It is a nickname of the regiment. Doggie." lUe flushed and embarrassed subject of the discusMon saw her lips move silently to the word. },i^»t,T^^ "i"°-. ^""^ ^ ^'-^ai'ge thing about rZf^f r^ ^" •* ^«« « "■'tter of her Bps and rarely of her eyes, which always maintained the hauntmg sadness of their tragic depths. .Monsieur Trevor,'' she repeated, imitatively. hhe repeated that also, whereat Mo jmnned fatuously showing his litUe yellow teeth C?h his scrubby red moustache. )eneath You've got it right fust time. Miss." ITom her two steps height of vantace she lookr 1 down on the three upti^ed Britislf fo^s - - ^ J her eyes v.ent cahnly from one to the other . bhe tmned to Doggie. "One would sav Monsieur^ that you were the Three Musietee^^' '•Man, I know it," replied Phineas. « WtT^ be blowedl " cried Mo Shendiah. "She's abitoforiMht.8hei8. What I caU class. D(^'? nevi^ di'SnSl^/f.v'"' "^ "^^'^ .^^ S^^^^di^b nntn Kw J u- .?y °®^«'" dawned on Doerie unt^l he found himself at it that evening. ^ fTS^Bon5 W"^'' "^r"^ insti^eSoH Tm 7l,» • ^' "^.^ P^^ym, with his sensitive slull, the airs they loved. BTe had just fiSed at ^"' .^L^'^"-^- -•l fe'iferciTrun^ and received his meed of applause when ^Jn^! came out of the Wtchen, tw^^eaTzinc (^S'S W It 18 my aunt who has awakened." , "l?i t <">«« fas aheady at the door. " I will go up, Ma amseUe Jeanne. Do not derange yourself" themselves alone together. "If you don't continue your sewing, Mademoiselle, said Doggie, "I shall think that I am disturbuig you, and must bid you good-night." "Vous ties bien aimable. Mademoiselle Jeanne," said Doggie, sitting down on a straight backed chair by the oil-cloth covered kitchen table which was between them. It hid her from his view. He moved it somewhat to her left. It threw shadows over her features, accentuating their "PPf?'^ sadness. He watched her and thought ot McPhail's words about the ghosts. He noted too, as the needle went in and out of the fabnc, that her hands, though roughened by coarse work, were finely made, with long fingers and dehcate wrists. He broke a silence that grew embarrassmg. "But yes, I have seen too much of it not to know. 1 see m the eyes. Your two comrades to-day — they aie good fellows — but they have not suffered, lou are different." SJ°^ ^° °? M°^« ^ ^eir world. Your Tommies are wonderful in their kindness and cMTalrv untd^n^t them I.had never seen an EngfihS^ wn.,u iT -^ imiecile ideas — I thSught thev would be wiUiout manners -«„ pea Stonfe I found I could walk among them, idthoutfe^ as if I were a princess. It is trie." ' ""'""""t 1^. as E tk ^^""^ ??X woman's knowledge -- and I know there is a difrerence between you and^the others. You have a delicacy o&3ffiL^ You were not bom to be a soldier." ^" relented. "You know very well what I mean," she said rebukingly. 'And you don't deserve that I should tell It to you. It was my intention to say that you have sacrificed many things to make yourself a simple soldier." Under the speU of her dark eyes Doggie said, as he had said to Phineas after; the going West of Taffy Jones, "I think. Mademoiselle Jeanne, it was rather to fight for my soul." She resumed her sewing. "That's what I meant long ago, she remarked with the iiKi draw of the needle. "No one could fight for his soul without Cmg throueb suffering.'^ She went on sewing. "Pe, shrmking from a reply that might have sounded fatuous, remained silent; but he realised a wonderful faculty of comprehension in Jeanne. 'An English poet has said 'Knowledge comes, but wisdom lingers " — Doggie had rather a fight to express the meaning exactly in French — "You dont gather wisdom in convents." we tned to go by train. Pas moyen. We took to ^e road, with many others. V^could no °^et^ On?v«"TJ'!i"':^ postponed our flight tiUtoo kte fh^L ^"l/^""^, ^^^ necess^ies and prec^i^ uungs. And we walked until we nearlv Ai^^t fest we got lost and found ourselvrb a Me wld fh^T ' ^" I 'aughed, to cheer my parents for have U. ». . „i tl":^ ^'°^ hSXh I did not know and shall never know what they said. But my father protested in anger, and stood in front of the horse making gestures. And then me oflicer took out his revolver and shot him through the heai- and he feU dead. And the murderer turned hid »">rse's head round and he laughed. He laudbed, Ai , "jur." one continued in the same even voice: "My mother became mad. She was a peasant, a Bretonne, where the blood is fierce, and she screamed and chmg to the bridle of the horse. And he rode her down and the horse trampled on her. Then he pointed at me, who was supporting the body of my latiier, and three men dismounted. But suddenly be heard something, gave an order and the men mounted again, and they all rode away laughing and jeenng, and the last man, in bad French, shouted at me a foul insult. And I was there, Monsieur 1 revor, with my father dead and my mother stunned and bruised and bleeding." He said with tense face: ".^c.^"^^ ™® strength to kill every German I see! She nodded slowly. " No German is a hiunan bemg. If I were God, I would exterminate the accursed race Uke wolves." . /^"'^ Dieu I almost forget. I was overwhehned with grief Mid horror. Some hoiu« afterwards a small body of English infantry came — many of them had blwdstamed bandages. An officer, who spoke a httle French, questioned me. I told him what had happened. He spoke with another officer, and because I recognised the word Uhlans, I knew they youreelf toTpKfsSetv" A ^^^ ""^h^"- «°d three bottles &IZ StfiLr ^^'' ^^'^ «'« ""^y rally I gave it all f„^?i^ "^Pl"''''''™- Natuoallll a^;^L^^roWS/nI^ -^^^ ^°°^- He tributed th^, wMe I was tl^H^'^'"'''^ ""^ 'l^ But I noticed thatThe twr^ffi^"4°«. "^ ™°ther. men. . . . Then tJiPv H,.i„ r..T ^gush gentle6a£oj\|n.«e,, {T ^f fer '"^^ ^'Tf ' ' ^'"^ * finished . . the Hflr.<,«r ^ • • • It was soon soldie,^ U>ika^i'ZdZV,T^: 'J ^^ «»"« my mother lyi^^n to/^ « 'r?'f " '^' ith and I walkedN^fh^L^'^ l?"^ ''"'^ possessions, was blotZl out'tiS TatZ? ^w7^t °^ ""^ '^^ Route Nationale aeain «mf^; Ya ^°'. ™ « the Retreat. Cd ki Te ^Vh? T«'^ «gain. >^ith the ing, there wL a hdt f Ipf T """'^ ^^' '"a^^hw^ cold, Monsieit^^/aTrti^ "i^he'wt d^ad'"^ ^e conS ^^•='^^- ^^' a^'lernfoits handcart. It was the market square of a little TVij "'®?®'* many— old men and women and children, refugees like me. I rose and found a papCT — a leaf torn from a notebook — fixed to the handcart. It was from the officer, bidding me farewell. That is how I &st met the English, Monsieur Trevor. They had earned me, I suppose, on the handcart, all night they who were broken with weariness. I owe them my life and my reason." she repued simply. She went on with her sewing. Doggie wondered how her hand could be so steady. There was a long silence. What words, save vain imprecations on the accursed race, were adequate? Presently her glance rested for a second or two on his sensitive face. Doggie took out his pink packet and lit a cigarette. You are very understanding. Mademoiselle Jeanne. !••• it does a selfish man like me good to be saddened hy a story like yours. I have not had much opportumty in my life of feeUng for another's suffering. .\nd smce the wo r — I am abruli." widower, with his tar^^'J^^^J'^^^ "^one. a children. We thought we w^ «^„ "f. ',°** "» came that the G^aiw JI^ i " '^"' "«» We had time to a7 Art,ZT '^^"l^ advancing. P^re Grigou! wh7-lov^SL'«'^rm?«''r«^' obstinate. To a Frendmnrrf'i.^ -^ ^^ "°^'« was his flesh and hi^ bh^dTe wo„ W^ ^T^^ « leave it. And my S hnVUhl ^ ^^ '?t^«'" than and mother on hlTdi^^lf/toldpLf^'y '«««' take me away, but I staverf wt.h k- , ^"«°^ ^ Grigou who forced 4 ?^,^r ^«t V Tf^ ^^^^ days. There was a well in f^w ^ hat lasted two P^re Grigou ti«l .m ™ J ""^ ^"™' «nd one night jewelry ^rm^fethlKreL^',,™}: """^A thinp we had, in a paff ^f 3'' ^ ?« P'^^o^s itw?th a W strSi^H^tl ,J^^'TJ™of and sank Germans coiSd nXLdTt f^ ^"5 ^ !>« the insisted. One day iT^i In/m ^"^'^'^^ ^«t he out of the little c^i^^Tere v^ ha^\' '^'If^.V went order to reconnoitre ftI,T 1 . ''*'> hiding, in might be S away and mv"^^, «»e GenS^ not listen to me, Zk h^l,"^ S"'^' T'''' ^"'Jd a shot -and then^ot^Yn.^'^^^'y ^ ^^"^^ it meant. And s^ p\|!; r^"" ^ »"««s what I reflected that soon the Boches would be here also. And we went on. We got to a high road — and once more I was among troops and refugees. I met some kind folks in a carriage, a Monsieur and Madame Tarride, and they took me in. And so I got to Paris, where I had the hospitality of a friend of the Convent, who was married. "He insisted on going back to bury my uncle. Nothing could move him. He had not parted from him all his hfe. They were foster-brothers. Where he is now, who knows?" She paused, looked again at her ghosts, and continued: "That is all. Monsieur Trevor. The Germans passed through here and repassed on their retreat, and, as soon as it was safe, I came to help my aunt, who was souffrante, and had lost her son. Also because I could not live on charity on my friend, for, voyez-vous, I was without a sou — all my money having been hidden in the well bv PSre Grigou.''^ ' Her cheek flushed. "I am not the raaly Frenchwoman who has passed through such things and kept herself proud. But the struggle has been very hard." do " criXhp'^r ' -^"^ IP E°^««h as well as I ao, cried the admirm^ ,vIo. "Yuss VVhpn hie ton comes, up and down' in the streeTby the gate '' He saw her puzzled look. "Roo. Port!'' ^fd he .Some time later, he disturbed Phineas, by whose side he slept, from his initial preparation for slumber. ... ,^®'= . I^ there any book I could learn this bunking lingo fromP " Itwasno^'userSgatineifW" "^ « "^"^'^t«»nditions. TbsoSly^^Zf^ ^^"^^^ irremediable of his position wa^iw°^'^?'« the acceptance pride. It w^ Se tW^kpnt^^t '''?'^«« °f his smileonhish-pswMehiLr^L ^^ H"''' ^-onical mg with straiL. ^e fi^t ?^? T'^ ^"^t breakhe was physically s^ck _ r,„t^ H "^Z "^^^^ ^^ it better Uianmost keenW^ ™ ^^^' ¥ ^^ stood whose function it was to Zw ^^^ ^'^ ^is captam -but from aheene!^ol^°,'^'^°=«'°"' fece hideous noise. Xstench^l^/T'T «»^''t the the earth, ^e ^ght of ' «-i^ ^^ ^ ""^^^^"^ "^ bombardiient wTovi TfW i°t"- ^^^ the would have sat do^ . 1i ^ •''^' heen alone, he grown accuatomedrthrfoS oSf. '^'.^^ The sounder his phvsical !v,m?^ .u trenches, his delicately train^H »! 'Condition, the more did when fierce "LScra^^' T^h i '^''^ ""Jy that he couldthrw C^f ^""^ ^''^ ««°ses, sleep, that he co^d Iw^^ ^^^ anywhere and foocf or drink ^erJf^f i^/^'"? '" the way of Yet, what had once bin^'^K^"^^^ '''^^y- • • • decent, nerve-rZL™^i-°.^™,« torture, the inhad now beco^P^eo^a^n ^?,^'^«^'« hfe. much . --panionshipXe^SSeniVTntr^CLl^ with Phineas and Mo, that he found an anodyne, but in the consciousness of being magnetically affected by the crowd of his feUows. They offered him protection agamst himself. Whatever pangs of self-pity he felt, whatever wan httle pleadings tor the bit of fine porcelain compelled to a rourfi usage which vessels of coarser clay could disregard came Ungeringly into his mmd, he dared not expres^ them to a hvmg soul around. On the contrary he set himself assiduously to cultivate the earthenware habit of spirit; not to feel, not to think, only to endure. To a humorously incredulous Jeanne he proclaimed hunself abruli. Finally, the ceaseless grind of the military machme left him little time to think. But in the soUtary sleepless hours of sentry duty there was nothing to do but think; notning wher^ with to while away the time but an orgy of introspection. First came the ahnost paralysmg sense of responsibiUty. He must keep, not only awake, but alert to the shghtest sound, the slightest movement. Lives of men depended on hki vigilance. If he did, he wouW challenge mice and shoot at cloud-shadows and bring the deuce of a commotion about his ears. And this Doggie, who did not lack ordinary intelligence, reaUsed. So he strove to think of otlier thmgs. And the other Uungs all focussed down upon his Doggie self -vnd he never knew what to make of his Doggie sell at all. For he would curse the things that he once loved as being the cause of his inexpiable sname, and at the same time yearn for them with an agony of longing. And he would force himself to think of Peggy and her unswervkg loyalty. Of her weekly pircel of dainty food which had arrived that mbrmng Of bis 4,d wax.der^\Ti tlS^'ofe^^^^^ numiLatiom and its mppHq orvj ^ " . ^"" '^s welcomed en«ny flL«^rf^l'\yf«™^K8. He It was supremely silly of him to march with super-martiafity of tread up the pavement; but tnen It 18 often the way of young men to do supremely silly things. The next day was fuss and bustle, from the private soldier s point of view. They were marclunjf DacJj to the trenches that night, and a crack company must take over with flawless equipment and in flawless bodily health. In the afternoon Doggie had a breathmg speU of leisure. He waUied boldly mto the kitchen. ' gladr ' '^" ^« Quar^Master says. tioSftaJrml^S?" ^^'^ -« ^-er que. ac\|ueryinhisXceXS^^h'"dhma. Me/ting Doggie emb^ldeied seS^^f^ °t" ^'«' a^d by her side, and they kok^^ ?» the comer, flagged courtyard irTwhich f?l "^"^ ""^^ *»« ««le shirtsleeves, Lme ii^2s wp?/°.' ''°?" ^ g'^y gnong the little pil^ aU^.r^ 'T^« «^"t Here and there a man woc^ ^^™^°'« and packs, little mirror suppo^"!,"' f ^"^1 by the aifof a laughter were IK? tie m.^.f'^rr- "^^<« and httfe group were fSdiL „L^ ®* afternoon air. A of crLbF, had s3J'f:T '^^ch. at the sight colombier fe the fr^lr^'^^^"* ^om U.e ^U voice. "The war, mon ami," she replied, turning her face towards him, "the haunting tragedy of the war. I don t know how to express what I mean. If all those brave fellows there w nt about with serious faces, I should not be affected. Mais, voyez-vous kur gaiele fail pew." Their laughter frightened her. Doggie, vith his c[mck responsiveness, understood. She had put mto a phrase the haunting tragedy of the war. Tne eternal laughter of youth quenched in a gurgle of the throat. She looked at him cahnly and critically. "Yes. Now I see. Until now I should have given yoii more. But the war ages people. Isn't it true? " I suppose so," said Doggie. Then he had i bnUiant idea. "But when the war is over, we'll remain the same age for ever and ever." "I'm sure of it. We'll still both be in our twenties. Let us suppose the war puts ten years of experience and suffermg, and what not, on to our lives. We'll only then be in our thirties — and nothing possibly can happen to make us grow any older. At seventy we shall still be thirty." thereVdheeHrJa^^d^' «7Sli^y; '' gone among an Enslish ^^Z ^^ '?"''' J^ave an old matron? Do vo" tiT?^ ~ "" ?^n«- like 6ien efe,ee c^uld have teIkSlV'"'1-^'''/"''V«»« done, the past twrdayl?"^,^^^ "fe«« ' ^ave tion IS the war " Aosura. ihe explana- and unthinkingly perched hir^^/i '," ^^««. table on theZrn^'lrJ^^J^lZ^^ ^''^''^ legged way. Doggie gasi^Lin^^l if t' "" " ''"^ age feU from her Bkp n T ^1 her assumed cfaimed itself in her att;tnHf™i"u ^""'^ J»«>of her figure "wL w' "'•^/^" «"?/?'« J^es with aTteadfast ^ul th«t\ /k ^^'^ ^' ■» «W utterable firSfbun Jri L^^'r^'^". ^^'^ ^ ^felt mighty protecSve ^ ^^P'^^" ^^^«t>'e- He ..An understanding? All right," said he above social laws. I am nJ r , themselves my finger-tips, and I r^rTnce LX'lf^"^'''- '^ and prejudices in which [«?» TT ^ °i* maxuns tions are different Tt ;= • T?->™- 2ut condi- girls of his acquamtance, who would have taken this chance companionship as a matter of course, that his face lost the smile and became grave, and he met her sad eyes. and stood on indignant feet. "Jeannel How could you — ?" he cried. She leaned back, her open pakns on the table. The rare light came into her eyes. Now he had in his pocket a letter from Peggy, received that morning, beginning "My dearest Marmaduke. Peggy seemed far away and the name still further. He was deliberating whether he should say " Appelez-moi James" or "Appelezmoi Jaeques,' and inclining to the latter as being more^icturesque and intimate, when she went on: "A la guerre comme a la auern- If «„.. •• that, you belong to the regCm" Xnll ^' ?« you ,t M a fine regiment •• * ''^"'- ^^ ^ promise .';^ bien, Monsieur Doe-ine~" BenjSX^'chS „rt''''u^^ ^'^ ^^ h« little fortune woTjd ^« t ?l^ ^^^l" ^" "" ^er whom Jeare h "d'tv"^, ^,^^' «''°'^«1 Gaspard But the Farm of La Folette? no farm left. It was a thing that Doggie most perfectly understood: a patch of hideous wilderness, of poisoned, shell-scarred, ditch-defiled, barren, loathsome earth. And her other relations? Only an uncle, her father's youngest brother, a cuil in Douai in enemy occupation. She had not heard of him since the flight from Cambrai. \|But what is going to become of you?" "So long as one keeps a brave heart what does it matter? I am strong. I have a good enough education. I can earn my living. Oh, don't make any mistake. I have no pity for myself. Those who waste efforts in pitying themselves are not of the stuff to make France victorious." said he. Jeanne slid from the table and welcomed the newcomers in her calm, dignified way. Once more Doggie found hunseljf regarding her as his senior in age and wisdom and conduct of Ufe. The pathetic girhshness which she had revealed to him had gone. The age-investing ghosts had returned. I only wish to explain to yon that whll^'r P"'"^need have no fear for DoS I wTn ^^^« y?" with my body from ^IipII?^ a ^^ .Protect him him safe h«ck iTJ \ "?^ Promise to bring ShenZ." ° y°"- ^d «> wiU Monsieuf even voice: Jeanne said in her ^;i hope all the Three Musketeers wiU come back Mo extended a grimy hand "W«ii j .^ She sK^ S" ^r^^ I -"'t be Sg '^"''■''^'' Without waiting for a reply, he scribbled what was necessary on a sheet torn from a notebook and gave it to her. Their hands met. Doggie clattered into the yard. ' Been doin' a fine bit o' coartin', Doggie," said Private Appleyard from Taunton, who was sitting on a bcx near by and writing a letter on his knees. and Mo. "Laddie," sedd the former, "although I meant it at the time as a testimony of my affection, I've been thinking that what I said to the young leddy may not have been over tactful." "You're a pair of idiots," said Doggie, sitting down between them, and taking out his pink packet of Caporal. "Have a cigarette?" tobakker?" Jeanne's denunciation of selfpity had struck deep. Compared with her calanr .les, half of which would have been the stock-in-trade of a Greek dramatist wherewith to wring tears from mankind for a couple of thousand years, what were night, instead of a drizzle, he woiild have welcomed a waterspout. Something that really mattered. . . . Let the Heavens or the Hun rain molten lead. Something that would put him on an equahty with Jeaime ... Jeanne, with her dark, haunting eyes and mobile lips, and the slim, young figure and her splendid courage. A girl apart from the girls he had known, apart from the women he had known, the women whom he had imagined — and he had not imagined many — his traming had atrophied such imaginings of youth. Jeanne. Again her namp conjured up visions of the Great Jeanne of Domremy. If only he could have seen her once again I At the north end of the village the road took a sharp twist, skirting a bit of rismg ground. TTiere was just a glimmer of a wamiM; light which streamed athwart the turning ribbon of laden ants. And as Doggie wheeled through the dim ray, he beard a voice that rang out clear. He looked up swiftly. Caught the shadow of a shadow. But it was enough. It was Jeanne. She had kept her promise. The men responded incoherently, waving their hands, and Doggie's shout of "Merci!" was lost. But though he knew, with a wonderful throbbing knowledge, that Jeanne's cry was meant for him alone, he was thrilled by his comrades' instant response to Jeanne's voice. Not a man but he knew that it was Jeanne. But no matter. The company paid homage to Jeanne. INthe village of Fr^lus life went on as before. The same men, though a different regiment, failed its streets and its houses; for by what swns could the inhabitants distinguish one horde M English infantrymen from another? Once a Highland battalion had been billeted on them, and for the firot day or so they derived some excitement from the novelty of the costume; the tustonc Franco-Scottish tradition still lingered and they welcomed the old allies of France with special kmdliness; but they found that the habits and customs of the men in kilts were identical, in their French eyes, with those of the men in trousers. It IS true the Scotch had bagpipes. The village turned out to fasten to them ui whole-eyed and whole-eared wonder. And the memory of the skirling music remamed uidelible Otherwise there was little difference. And when « Midland regiment succeeded a fcouth Coast regiment, where was the difiference at all? They might be the same men. Jeanne, standing by the kitchen door, watching the famuiar scene in the courtyard, could scarcely beUeve there had been a change. Now and again, she caught herself wondering why she could not pick out any one of her Three Musketeers. There were two or three soldiers, as usual, helpuig Toinette with her crocks at the well, '^here she was, herself, moving among them, as courteously treated as though she were a princess. Perhaps these men, whom she heard had come from manufacturing centres, were a trifle rougher in ;heir manners than her late guests; but the intention of civility and rude cMvalipr was no less sincere. They came and asked for odcfs and ends very poUtely. todl intentS purposes they were the ^e ^t of men M.y ^ not Doggie among them? It seemed very sK^ After a while she made some sort of an amS tence with a sergeant who had a few worTof X^h ^d appeared anxious to improve his knowledge of the language He explained that he had bJn a iZ^'', '" ^"* corresponded to the French fcofe* Normaks. He came from Birmingham, which hi E\'- ^ "«'l''«t»nd was globed 'LUle She wo«h,-n^ r^ ea^est very^'self-centred in his worahip of efficiency. As he had striven for hirdMS of boys SO now was he striving for his pktoon^ men In a dogmatic way he expoZlS "S^^er Ideals severely practical. In their l^w casud cSn versations he mterested her. The Enrfish f^™ £h ^* "^"^^Z l«y «f »>«- as^iaS wWi he" lat^lv'°°^"^h"^''','^P^'^«tion. bT^^ lately — in the most recent past — her sex hpr national aloofness, and her ignorance of EnS had restrained her from famili^- talk wil^f fiS Army. But now she keenly desired to JmdeSSS tlus strange, imperturbable, kindly race Sh^^t many questions to the Sergeant -always at the kitchen door in full view of the courtS for Se never thought of admitting him into th^W hfL^f .answers even when he managed to make himself mte hgible puzzled her exceedingly One of h^ remarks led her to ask for what™Is fi^^ Ti^IZ^ ^ apparently fixed idea of the efficacy of the men under his control. What was the spiritual idea at the back of him? "By British eflSciency. By proving to him that we are superior to him in every way. We'll teach him that it doesn't pay to be a wolf." Jeanne shook her head. "No, Monsieur, wolf he 18 and wolf he will remain. A wolf with venomous teeth. The civilised world must see that the teeth are always drawn." "'',™ °?J ^^'^K ° ^^ ^ brother till the war is over, said the Sergeant stohdN. "At present I am devoting all my faculties to killing as many of him as I can." She left him and tried to puzzle out his philosophy. For the ordinary French philosophy of the war is very simple. They have no high-falutin', altruistic Ideas of unproving the Boche. They don't care a tmkers curse what happens to the unholy brood ^yond the Rhine, so long as they are beaten, humilated. subjected: so long as there is no chance of ««^^^''-i <^«fl°^«"ng again with their brutahty the rtv! .f "^-^^ ^'T'^ ^he French mind cannot conceive the Idea of this beautiful brotherhood; but something bordenng on spiritual defilement. . INo; Jeanne could not accept the theory that we were wagmg war for the ultimate chastemng and beatification of Germany. She preferred Doggie's reason for fighting. For his soul. There was wmeUung which she could grip. And having gripped It, It was somethmg around which her imagination could weave a web of noble fancy. After aS, when she came to thmk of it, every one of the allies must be faghtmg for his soul For his soul's sake had not her father died? Although she knew no word of German, It was obvious that the Uhlan officer had murdered hun because he had refused to betray his country. And her uncle. To fight for his soul, had he not gone out with this heroic but futile C^ ri,^i?- ^^ pragmatical sergeant? w^Sr^i^«i^ hun from his schoohwm to the She missed Dome. He ought to be there, as she nad otten seen him unobserved, talking with his fnends or gomg about his mihtary duties, or playing toe flageolet with the magical touch of the mSsician bhe knew far more of Doggie than he was aware of. ■ ij- ^^ ** night she prayed for the UtUe English soldier who was facmg Death. She had much time to think of him during the hours when she sat by the bedside of Aunt Morin who talked mcessantiy of Francois-Marie who was kUled on the Argonne, and Gaspard who, as a krritonal was no doubt defending Madagascar trom mvasion. And it was pleasant to thmk of him because he was a new distraction from tragical memones. He seemed to lay the ghosts. ... He was different from all the Enghshmen she had met. The young officers who had helped her in her flight, had venr much the same charm of breeding, very much the same intonation of voice: instinctively ^e knew him to be of the same social caste: but th^, and the officers whom she saw about the street and m the courtyard, when duty called them there, had the mihtary air of command. And this her httle Enghsh soldier had not. Of course he was only a private, and privates are trained to obedience, bhe knew that perfectly well. But why was he not commandm^ instead of obeying? lliere was a reason for it. She had seen it in his eyes. She wished she had made him talk more about himself. Perhaps she had been unsympathetic and selfish. He assumed, she reflected, a certain cr&nerie with his fellows — and cranerie is "swagger" bereft of vulgantj — we have no word to connote its conception m a French mind — and she admired it; but her swift mtuition pierced the assumption, bhe divined a world of hesitancies behind the Musketeer swing of the shoulders. He was so gentle, so sensiUve, so quick to imderstand. And yet so proud. And yet again so unconfessedly dependent. Her woman s protective instinct responded to a mute appeal. "But, Ma'amselle Jeanne, you are wet through, you are perished with cold. What folly have you been committing?" Toinette scolded when she returned after wishing Doggie the last "bonne chance. ^ "The folly of putting my Frenchwoman's heart ymon amr de Franaaise) into the hands of a brave httle soldier to fight with him in the trenches." thf^'inT^ifki'''?' ■"'^f to bed anf administered the mfaUible infusion of lime-leave, and Jelwne was never the worse for her adventure. But theI!fki •"/ ^t T"?^'^' 8 little why she had miderS of sy^^path?:" " ''^' ''^'^ ">«* •' P^«* « "»^« An evening or two afterwards, Jeanne was sewmg in the kitchen when Tomette, sittmg m the ai.* chair by the extinct fire, fished out of Her pocket tho litUe ohve-wood box with the pansies and foriretS.t"^j •." ^-l'"' ""'^ took a fong pinch of snuff, hhe did It with somewhat of an an- which caused Jeanne to smile. «tu«5u that. If anythmg happened to the petit MoruimF, ip 4^1d S^'-^' ^'"^ '° «° "* P""'^ ^ ^^^ "Nothing will happen to him," said Jeanne. Ihepld woman sighed and re-engulfed the snufffiox. Who knows? From one mmute to another who knows whether the litUe ones who are dear to us are ahve or dead?" ''Since he resembles my petiot." He will come back," said Jeanne. I hope so," said the old woman mournfully In spit of manifold duties, Jeanne found the days curiously long She slept badly. The tramp of the ^ntr>' below her window over the archway brought her no sense of comfort, as it had done for momhs before the coming of Doggie. All the lew did it produce the queer litJe thrill of happiness which was ben when, looking down through the shutter stats, she had identified in the darkness, on a change of Kuard, the little EngUsh soldier to whom she had spoken so mtimntely. And when he had challenged the Rounds, she had recognised his voice. ... If she had obeyed an imbecile and unmaidenly impulse L ^?"'«' liave drawn open the shutter and revealed herself. But apart from maidenly shrinkings, familiarity with war had made her realise the sacred duties of a sentry, and she had remained in discreet seclusion, awake until his spell was over. But now the rhvthmical beat of the heavy boots kept her frona sleeping, and would have irritated her nerves mtolerably had not her sound common-sense told her that the stout fellow wh, wore them was protecting her from the Hun, together with a milhon or so of his fellow-countrymen. .•'«L'**' '^ ^ to-morrow I" she said to Toinette. What 18 It to-morrow?" asked the old woman. The return of our regiment," r<^plied Jeanne. That is good. We have a regiment now," said 1 omette, iromcally. The Midland company marched away — as so many had marched away before; bu,' Jeanne did not go to the httle embankment at the turn of the road to wish anyone good luck. She stood at the house door, as she had always done, to watch them pass m the darkness; for there is alwpvs something m the sight of men going into battle which gives you a lump m the throat. For Jeanne it had ahnost grown into a religious practice. The Sergeant bad told her that the newcomers would arrive at dawn. She slept a little; awoke with a start as day began ti^ break; dressed swiftly. and wen», downstairs to wair. And then her ear caught the rumble and the tramp of the approachmg battahon. PresenUy transport rolled by. and squads of men, haggard in the grey light, bending double under their packs, staggered along to their bilieU. And then came a rusty crew, among whom she recogniEed McPhail's tall, gaunt figure. She stood by the gateway, bareheaded, in her black dress and blue apron, defying the sharp morning air, and watched them pass through. She saw Mo Shendish, his eyes on the heels of the man in front. She recognised nearly all. But the man she looked for was not there. He could not have passed without her seeing him; but as soon as the gateway was clear, she ran into the courtyard and fled across it to cut off the men. There was no Doggie. Blank disappointment was succeedsd by sudden terror. Phineas saw her coming. He stumbled up to her, dropped his pack at her fest, and spread out b >'h his hands. She lost sight of the horde of wean-, ciaycovered men aroimd her. She cried: "But you most know, you I" cried Jeanne, with R new fear m her eyes which Phineas could not bear to meet, " You promised to bring him back." "It was not my fault," said Phineas. "He was out on patrol last ni^ht — no, the night before, this is morning — repainng barbed wire. I was not with him. «I?™ Suddenly a Gennan rifle-shot gave the &; ^u enemy threw up star-shells and the front trenches on each side opened fire. The wirinir party of course lavflat on the ground. One of theS was wounded. When it was aU over, -it didn™ -ast long, - our men got back bringing the wounded insuim Iter vt ^' P.^^' r P^T^'°° « P °"S h^t. ■ '^^ed an round where tie repairs had been going on. But we could not find him '^ aurU/r Y y""' \^« ^^- "Fo^^he 'moment. s^T ^. u°^ ™"f * ^% ""o™ «"t with fatigue." She left hun and walked through the straggling men, who made respectful way for Ler. All C the nature of this interview. They hked Doggie because he was good-natured and plucky, and nl^r complamed and would play the whist^ on m^ch as long as breath enough remained in his body As his micle the Dean, had said, breed told. ^ In a iTr,' ''f J''"'l^'il? ^^y ^^^y recognised the fact They laughed at his singular inefficiency in the multitudmous arts of the handy man, proficiencv in which IS expected from the moderA CivatT'^bi? reprimand which his absurd efforts in the arts aforesaid would have brought upon him. And ^ that Dogpe was gone, they deplored his loss. But 80 many Vd gone. So many^ad been dlpbr^ Human nature .s only capable' of a certain ZoS of deplonng whJe retainmg its sanity. The men let the pale French girl, who was Doggie Trev^r^ fnend, pass by m respectful silence -^d that fo? them was their final tribute to Doggie Trevor Jeanne pa^ed into the kitchen. II n'est pas la?" ■ ^^'" ^^ Jeanne. "He is wounded," It was mijpossible to explain to Toinette. Badly?" an?Lo!f^h^^ """^^ '^" "P ^"^ ^^^ hot water, ^i? J^^-.u™Fy' "^^^^ nerve-racked men were served with the mommg meal. And Jeanne f.Tl"? ^^ courtyard in front of the kitchen dTr and helped with the fiUing of the tea-kettles n« though no httle Enghsh soldier c^ed "DSie^ had ever existed in the regiment kitlJpn^* ^^i ^^^^ °^ '"^'gJ't fell upon the lutchen side of the courtyard, and in it Jean^ stood Jlurnmated. It touched^ the shades of gold in hS dark brown hair, and ht up her pale fact and great mismding eyes. But her U^s smil^ valiant^ sauS t r f'"^.' ^^?A' ^'^ Mo Shendish. re^a%?wiront&?^"" '° ^°" '""^ ^^'■^ -"Man," replied Phineas, "all I know is that she has added him to her collection of gholts Ks not an over braw company for a lassie to live with." And then, soon afterwards, the trench-broken men stumbled into the bam to sleep, and all was quiet again, and Jeanne went about her daily tasks with the famihar hand of death once more closing icily around her heart. Jeanne opened a window, r \ 1^ ^°'™ complained of currents of air. LA Jeanne want to kill her? So Jeanne closed the wmdow. The internal malady from which Aunt Morm suffered, and from which it was unhkely that she would recover, caused her considerable pam from tune to tune; and on these occasions she grew fractious and hard to bear with. The retu-ed septuagenanan village doctor who had taken the modest practise of his son, now far away with the army, advised mi operation. But Aunt Morin with her peasant s prejudice, decUned flatly. She fcaew what happened in those hospitals where they cut people up just for the pleasilre of lookL- at their msides. She was not gomg to let a lot of Oht^f ^T .tl^T'^lves with her old carcase. Uh, mm! When it pleased the hon Dieu to take her she was ready: the bon Dieu required no assist tance from ces rwssj^urs. And even if she had consented how to take her to Paris, and once there, how to get the operation perfonned, with aU the hospitals tuU and all the surgeons at the front? The old doctor shrugged his shouldera and kept hfe in her as best he might. f ^tt^^^i' ^ ^^ '^^^^ '■°°'"' ^^^ toW a long story ot the doctors neglect. The medicine he gave her was water and nothing else - water with no& Aunt Morin complained of being robbed on all sides. The doctor, Toinette, Jeanne, the English soldiers — the last the worst of all. Besides not paying suflSciently for what they had, they were so wasteful in the things they took for nothing. If they begged for a few faggots to make a fire, they walked away with the whole wood-stack. She knew them. But all soldiers were the same. They thought that, in time of war, civilians had no rights. One of these days she would get up and come downstairs and see for herself the robbery that was going on. The windows were tightly sealed. The sunlight hurting Aunt Morin's eyes, the outside shutters were half closed. The room felt Uke a stuffy, overheated, over-crowded sepulchre. An enormous oak press, part of her Breton dowry, took up most of the side of one wall. This, together wiUi a great handsome bahul, a couple of tables, a stiff armdiair, were all too big for the moderately-sized apartment. Coloured prints of sacred subjects, tilted at violent angles, seemed eager to occupy as much air space as possible. And m the middle of the floor sprawled the vast oaken bed, with its heavy green brocade curtains falling tentwise from a great tarnished gilt crown in the ceiling. Jeaime s< id nothing. What was the good? She shifted the invalid's hot pillow and gave her a drink of tisane, moving about the over-furnished, airless room in her calm and efiScient way. Her face showed no sign of trouble, but an iron band clamped her forehead above her burning eyes. She could perform her nurse's duties, but it was beyond her power to concentrate her mind on the sick woman's unending litany of grievances. Far away beyond that darkened room, beyond that fretful voice, she saw vividly a hot waste, hideous with holes and rusted wire and shapes of horror; and in the middle of it lay huddled up a little khaki-clad figure with the sun blazing fiercely in h^ unblinking eyes. And his very body was beyond the reach of man, even of the most hon-hearted. But what, she thought, was indeed the good of youth, in these terrible days of war? Her own was but a panorama of death. . . . And now one more figure, this time one of youth, too, had joined it. Toinette came in. "Ma'amselle Jeanne, there are two F-nglish officers downstairs who wish to speak to you." "What do they want?" Jeanne asked wearily. "They do not say. They just ask for Ma'amselle Boissiere." "They never leave one in peace, ces gem-lh" grumbled Aunt Morin. "If they want more concessions in price, do not let them frighten you. Go to Monsieur le Maire to have it arranged with justice. _ Remember, Jeanne." She went downstairs, conscious of gripping herself in order to discuss with the officers whatever business of billeting was in hand. For she had dealt with aU such matters since her arrival in Frdlus. She reached the front door and saw a dustr^u^ with a mihtary chauffeur at the wheel, and two officers standing on the pavement at fhe foot of the steps. One she recogmsed as the commander of the company to which her biUeted men belonged. The other was a stranger, a heutenant, with a different badge on his cap. They were taUdng and laughing together, like oil friends newly met, whkh rlirti, ^ myriad coincidences of the war, was reaUy the case. On the appearance of Jeanne, they drew themselves up and saluted politely. ^ mj'ljt^^''"'' ™^ indiscretion. Mademoiselle - it is mihtojr service, and I am an Intelligence Officer but Wypu teU him about your privlte dTa^s?" «Ju^ Intelligence officer made a note or two and smiled pleasantly -but Jeanne could have struck him for daring to smile. "You had every re" for^tbplung him a man of honour=" ' «nf;t T"\ °"H,n^^°V^' uncomprehendmg, sat silent. He held it out to Jeanne. Mademoiselle, do you recognise this?" bhe looked at it dully for a moment; then suddenly sprang to her feet and clenched her hands and stared open-niouthed. She nodded. She could not speak. Her bram swam. They had come to her about Doggie who was dead, and they showed her "If this is your property. Mademoiselle." said hmithers, laying the packet on the cheniUe covered table, you have to thank your friend Trevor for restormg it to you. "But how the deuce was I to know?" Smithers muttered, with an injured air. "My instructions were to find out the truth of a cock-and-bull story — for toats what it seemed to come to. And a jrirl loughby. ^^ But who told her the fellow was dead? " Why, his pals. I thought so myself. When a man s missing, where's ore to suppose him to be — havmg supper at the Savoy?" "Not very seriously, MademoiseUe." Smithers castmg an mdignant glance at his superior officer's complacent smile, reassumed mastery of the situation. A Boche sniper got him in the leg. It wiU put him out of service for a month or two. But there is no danger." She leaned, for a while, against the cask, her hands behmd her, lookmg away from the two men. And tlie two yomig men stood, somewhat em- bMrassed, looking away from her and from each otfter. At last she said, with an obvious striving lor the even note in her voice: "I ask your pardon, Messieurs, but sometimes sudden happmess is more overwhehning than misfortune. I am now quite at your service." I uJ u ' *' " wonder," murmured Willoughby, who was fair, unmarried and impressionable. Smithers, dark and lean — in civi' life he had been concerned with the wine trade in Bordeaux — proceeded to carry out his instructions. P«rf'ec%. Monsieur," said Jeanne. {n fKo Sli' ^°^^'^- I' as a young girl, was not m the full confidence of my parents. But I remember niy uncle saying there were about twenty thousand francs m notes, some gold, I know not How much some jewellery of my mother's — oh, a big handful I — rings — one a hoop of emeralds and diamonds — a brooch with a black pearl belonpng to my great grandmother — " . "J^ ^ enough. Mademoiselle," saiu Smithere, jotting down notes. "Anything else besides money and jewellery? •' stifflyy^ °* ° °"^^ ™^ '^P"^' ^^■" '»^* Smithere, So the schedule was produced and the notes were solemnly counted twenty-one thousand five W dred francs, and the gold four hundred fran^. aTd the jewels were laentSied. and the bonds, of v^Wch Jeanne luiew nothing, were checked by a list in her father s handwriting, and Jeanne signed a paper wiS Smithers's fountain pen, and Willoughby witne^ S hSSge.^'^ ^"^ ^^^ entered fntJ^I^ bew!lHl^""A^°r" must pardon me, but I am quite bewildered. As far as I can understand. Monsieur Trevor rescued the packet from the well at irY3e" ^«™°^ La Folette. and got wounded in doing s^"' .. P »,''"' ^' ^'d Smithers. the topography right with a map. Trevor waf f^ V ^.°S«v.'?°^"^^ «"'* «« he's a man of^uTao. the farm marked by name, and the ruined weU away over to the left in No Man's Land. I re- ^^^^I^"" -^ ^^^^ ^^ '" 'La Folettol' in a startled voice and when I asked him what was the matter, he said ' Nothing, sir. '" Smithers translated and continued: "You see MademoiBcUe this is ^hat happened as far as I a^' concerned. I am attached to the Lancashire Fusi- li^lL f^J'a'tal'on » in the trenches about three miles further up the Une than our friends. WeU n™, .1, *"''" yesterday morning, a man roUed ^nTfJ^" ^«'«P«' ">to o"r trench, and promptly hT^- A f ^^^ ^^? wounded in the leg and was half dead from loss of blood. Under his tuiuc was tks package. We identified him and his regiment and fixed Turn up and took him to the dFessingl station. But thmgs looked very suspicious. Here was a man who did not belong to us with a little fortune in loot on his person. As soon as he was Hp^«M f h '^?^??^i; ^^ ^- 0. took him in hand. He told the C. 0. about you and your story He regarded the nearness of the weU as somethinj: to do with Destiny, and resolved to get you back your property -if it was still there. The opportimity ^^"^.t ""w" .u^^ •'^'TK .P^ty was^^'alarmeZ He crept out to the rums by the weU, fished out the packet and a smper got him. He managed to get fSJ^wu^^uu^'^'^^y/ ^^"S*^ Smithers. "Captain Willoughby wifl see to that. But reflect MademoiseUe. His military duty was to remain with his comrades, not to go and risk his life to get your property Anyhow, it is clear tnat he was not out for loot. . Of course they sent me here as In Ihgence Officer, to get corroboration ti L j"^•..A^^ P®"^^ '<«■ a "moment. Then he added. "Mademoiselle, I must congratulate you on the reBtoration of your fortune and the poMewion of a very brave friend." For the first time the red spot« bumed on Jeanne's The officers saluted and went their ways. Jeanne took up her packet and mounted to her Uttle room m a dream. Then she sat down on her bed, the unopened packet by her side, and strove to reahse It all. But the only articulate thought came to her m the words which she repeated over and over agam: "IlafaUcela pour moil II a fait cela pour moil" He had done that for her. It was incredible. faatMtic, thriJJingly true, like the fairy-tales of her cMdhopd. The little, sensitive Enghsh soldier whom his comrades protected. whoma«' heiseL •{ a fMnmme wav longed to protect, had don( this for her. In a shy, almost reverent way, she opened out the waterproof covering, as though to reassure herself of the reahty of thm«. For the first tune smce she left Lambrai a smile came into her eyes, sick room. "Eh 6ien? And the two officers," queried Aunt Morm after Toinette had gone. " They have stayed a long tune. What did they want?" Jeanne was young. She had eaten the bread of dependence which Aunt Morin, by reason of racial mstmct and the stress of sorrow and infirmity had contnved to render very bitter. She could not repress an exultant note m her voice. Doggie too accounted for something, i.jr murh. ' she stretched out a thin hand. "I 2 /wf'te Jeann« cherie. you are rich now." . 1 don t know exactly." replied Jeanne with a Kit-^"^'^ ""' =«"^°°- ' have en^ghfo^ ^'How did it all happn?" iwgpe. But now the thing was too sacred. Aunt ^Z-:^^'^ que8Uon..quesUon maddenSy. u^l the rainbow of her fairy-tale was unwovpn Thl inH;lo'.T'"?.«'^™'^.'^"' "ww'wn.'" cried Jeanne mdi«iantly. What do you think I am made^" .Ml ^breathed Aunt Morin, comforted. fJ^T^- ^°^^-r -^^t ^"^^ had a very comfortably mvested fortune left, for the late Monsieur Morrn, com, hay and seed merchant, had been a very astute person. It would make Uttle difference maiS^ ti^T "' "" ^ ™°°^' ^^ ^^^ ''Everyone must do what he can," said Jeanne. PerfecUy said Aunt Morin. "You are a young gu-1 who weU understands things. And now -It IS not good for young people to stay in a sick room -one needs the fresfi air. Va k distraire, mapetik. I am qmt« comfortable." wiSfA^'l'''"!''*.^"" ^F- The wonder of it bewildered her the pnde of it thriUed her. But he was wounded. fW smothered her iov. Thev made'^f.l^'nf ^^' ""^ ^'^''- ^"^ ^^l^iers alwayl ^„J;-li ^ °^ T"?"®.- I ^^ their way in t4 horrdjle war, m the mtimate midst of which she had .Z ft ^V " * '"^'^ ^^^ no* dead, he was ahve, and thereby accounted lucky. In then- gay oS tm\|sm they had given him a month or two of X sence from the regmient. But even in a m A or two -where would the regiment be? Far far jy from Frfilus. Would she ever see Doggie "Oh, many friends. You see, Mademoiselle," said Phineas, with a view to setting her mind at rest, "Doggie's an important person in his part of the country. He was brought up in luxury. I know because I lived with him as his tutor for seven years. His father and mother are dead and he could go on living in luxury now, if he liked." "He has a fine house of his own in the country, with many servants and automobiles and — wait — " he made a swift arithmetical calculation, "and an income of eighty thousand francs a year." frown. Phineas McPhail was enjoying himself, basking in the sunshine of Doggie s wealth. Also, when conversation in French resolved itself into the statement of simple facts, he could get along famously. So the temptation of the glib phrase outran his discretion. stony Cbhn. Phineas suddenly became aware of pitfalls, and summoned his craft and astuteness and knowledge of affairs. He smiled, as he thought, encouragingly. "Not always. Monsieur," said Jeanne, who had watched the gathering of the sagacities with her deep eyes. "In any case—" she rose and held out her hand — "our friend will be well looked after m England." But Plmieas had knocked all tlie drerjns out of Jeanne. The Bntish happy-golucky ways of marriage are not those of tte French bourgeoisie, and Jeanne had no notion of British happy-go-luckv ways. Phineas. had knocked the drelii^out o^ Jeanne by kicking Doggie out of her sphere. And there was a girl in England in Doggie's sphere whom he was to marry. She knew It. A man does not gather his sagacities in order to answer crookedly a direct chafienge, unless there is some necessity. o^auc Well. She would never see Doggie again. He would pass out of her Ufe. His destiny ciUed him If he suryi red the slaughter of the war, to the shadowy girl in ii.DgIand. Yet he had done thai for her. t or no other woman could he ever in this life do that apin. It was past love. Her brain boggled at an elusive spmtuaf idea. She was very young, flung clea^y tramed from the convent mto the wa?l terrihc tragedy, wherein maiden romantic fancies were scorched m the tender bud. Only her honest traditions of marriage remained. Of love she knew noting. She leaped beyond it. seeking, seekmg. She would never see him again. There she met the Absolute. But he had done Ihal for ber — that which she knew not why, but she knew —he would do for no other woman. The Splendour o! It would be her everlasting possession She undressed that night, proud, dry-eyed, heroical, and went to bed, and listened to the rhythmic tramp of the sentry across the gateway below her window, and suddenly a lump rose in her throat and she tell to crymg miserably. Ihe nurse moved on. Doggie drew the cool clean sheet aromid his shoulde^, andVave L^tf up to the luxury of bed — real bed TkIJ^ by a dehcious odour which after a while he reco^ msed as the scent of the sea. Where W^ he 3 no notion. He had absorbed so much o7to™'s philosophy as rot to care. He had airived Sa convoy the night before, after mudi toavd iT^! bulances by land and sea. If he had been a wdkmg case te might have taken more ktereTt in touched the bone, and in spite of l.mg carri^most tenderly about like a baby, he had iX^S pain, and longed for nothing and thoughfof noE bV /f™T"* 'esting-place. Now, appareX^ he had found one, and, looking about h^ he feTt' pecuharly content. He seem^ to havT^in no cleaner, whiter brighter place in the worid^ th^ this airy ward swept by the sea-brwzM Hp counted seven beds besidi his o>^ oTf taWe rumrnig down the ward stond a vase of slcetnS and a bowl of roses. He thought there w^ S She stared at him for a moment, adjusting things in her mind; for his name and style were 35792 Private Trevor, J. M., but his voice and phrase were those of her own social class. Then she smiled and told him. The comer of fairyland was a private auxiUary hospiteJ in a Lancashire seaside town. " Lancashire," said Doggie, knitting his brow in a puzzled way, "but why have they sent me to Lancashire? I belong to a West country regiment, and all my friends tu-e in the South." "What's he grousing about. Sister?" suddenly asked the occupant of the next bed. "He's the sort of chap that doesn't know when he's in luck and when he isn't. I'm in the Duke of Cornwall's Light Infantry, I am, and when I was hit before, they sent me to a miUtary hospital in Inverness. That'd teach you, my lad. This for me every time. You ought to have something to grouse at.'' himself on his elbow. The nurse intervened; explained that no one could be said to grmnble at a hospital when he called it Fairyland. Trevor's question was that of one in search of information. He did not realise that in assigning men to the various hospitals in the United Kingdom, the authorities could not possibly take into account an individual man's local association. n.'.l^^ ^^n "° "?J^' t« ^«" me an idjit." said the Duke of Cornw^s Light Infantryman He was an aggressive red-visaged man witi Tistly bkck ^^jf^'^ «t4tbly. black moustache. ^' ^ yout'ii."^'^^ ^'^^°' -^ «P«'°& f°-a£^ And into the nurse's eyes crept the queer smile of the woman learned in the ways of chilS-eiL "Where did you get it?" asked Penworthy. m=^°^^K ^a^^the information, and, in 4 turn made the polite comiter enquiry. PenTortWs bit of shrapnel, which had broken a rib or Chad been acqmred just north of Albert. When he left Me? The Duke of ComwaU's Light Infantryman shook his head. "I take things af I fi^fi and I finds this quite good enough?^ ' WhJe his leg was being dressed he reflected that, a couple of years ago, if anyone had inflicted a twentieth part of such torture on him he would have yelled the house down. He remembered, with an mward grin, the anguished precautions on which he had msisted whenever he sat down in the expensive London dentist's chair. So Doggie nodded and smiled and curled up as best he could, and slept the heavy sleep of the tired young ammal. It was only when he awoke, physically rested and comparatively free from pain, that nis mmd, hitherto confused, began to work clearly to straighten out the three days' tangle. — Y^' just three days. A fact ahnost impossible to realise! lui now It had seemed an eternity. He lay with his arms crossed under his head and stared at the blue sky. It seemed a soft, comforting, linghshsky. The ward was silent. Only two beds were occupied, one by a man asleep, the other by a man reading a novel. His other roommates, includmg bis neighbour Penworthy, were so far convaiMcent as to be up and away, presumably by the life-givmg SOT, whose rhythmic murmur he could ??"• ,/°^ Y^^ fi^t time since he awoke to find tmnself bandaged up in a strange dugout and surrounded by strange faces, did the chaos of his ideas resolve itself mto anything hke definite memories, let many of them were still vague. _ He had been out there, with the wiring partv, m the dark. He had been glad, he remembered, to escape from the prison of the trench into the open air. He was h.nng some difficulty with a r^alcitrant b.t of wire tiat refused to come sSht ^d jabbed him diabolically in unexpected pl3 when a shot ran^- oat and German ifares went S and everybody lay ilat on the ground, wWirbdletS spat about them. As he lay%n hk stomach a ^ the weU and his nose and his heels were in a bee-lme. The reahsation of the fact was the in! ception of a fascmatmg idea. He remembered that qmte clearly. Of course his discovery, two days before of the spot where Jeanne's fortune lay hidden fr h{« senior subaltern, with map and periscow' had called hnn into consultation, had setKem beatmg and his unagmaUon working. But not till that moment of stark opportunity had he dreamed fn tLT^f adventure wKch he .idertook. T^re^ m front of him at the very farthest five hundred yards away, m bee-line with nose and heels - that was the pecuLar and particular arresting fact -lav sky and wondered how he did it. And yet «L^rJf?^ • • •'?i?™^y J? ^^ '"^ed well seemed the sunplest thmg m the world. The thought of Jeanne's dehght shone uppermost in his mind. . Oh! he was forgettmg the star, which hung low beneath a ^opy of cloud the extreme point of theSZ feet, nose and well bee-line. He made for it, now and then walking low, now and then crawling. He did not mind Las clothes and hands being torn by the unseen refuse of No Man's Land. His chief sensation was one of utter loneliness, mingled w" h exultance at frt;€!doin. He did not remember feeling afraid: which was odd, because when the starshells had gone up and the German trenches had opened fire on the wiring party, his blood had turned to water and his heart had sunk into his boots, and he had been deucedly frightened. Heaven mu"t have guided him straight to the well. He had known all along that he merely would have to stick his hand down to find the rope . . . and he felt no surprise when the rope actually came in contact with nis groping fingers; no surprise when he pulled and pu! d emd fished up the packet. It had all been pre-ordained. That w{ts the funny part of the busmess which Doggie now could not unlcrstand. He repressed his desire to sing, but he leaped about and started to run. Then the star in which he trusted must have betrayed him. It must have shed upon him a ray just strong enough to make him a visible object; for, suddenly, ping! something hit him violently on the leg and bowleid him over like a rabbit into a providential shellhole. And there he lay quaking for a long time, while the lunacy of his adventure coarsely and unsentimentally revealed itself. As to the rest, he was in a state of befogged memory. Only one incident in that endless, cruel crawl home remained as landmark in his mind. He had paused to take breath, almost ready to give up the mipossible flight — it seemed as though he were dragging behind him a ton of red-hot iron — when he became conscious of a stench violent in his nostrils. He put out a hand. It encountered a horrible, once numan, face, and his fingers touched a round, recognisable cap. , . . Then all was fog and dark again until he recovered consciousness in the strange dug-out. The memory caused a flicker round his Ups. It wasn't everybody who could crawl on his belly for nearly a quarter of a mile with a bullet through his leg, and come up smihng at the end of it. A castiron constitution! If he had only known it fifteen, even ten years ago, what a different life he might have led I The great disgrace would never have come upon him. And Jeanne? What of Jeanne? After he had told his story, they had given him to understand that an oflBcer would be sent to Fr^lus to corroborate It, and, if he found it true, that Jeanne would enter into possession of her packet. And that was all he knew; for they had bundled him out of the front trenches as quickly as possible; and once out he had become a case, a stretcher case, and although he had been treated as a case, with abnost superhuman tenderness, not a soul regarded hun as a human being with a persoaahty or a history — not even with a mihtary history. And this same military history had vaguely worried him all the time, and now that he could think clearly, worried him with a very definite worry. In leaving his firing party he had been guilty of a crime. Every misdemeanour in the army is termed a crune — from murder to appearing buttonless on parade. Was it desertion? If so, he might be shot. He had not thought of that when he started on his quest. It had seemed so simple to account for half an hour's absence by saying that he had lost his way in the dark. But now, that plausible excuse was invahd. . . . matter what they did to him. Sticking him up against a waU and shooting him was a remotfl possibihty; he was m the British and not the Genr— Anny. Field punishmenU of unpleasant kii.ua were only inflicted on people convicted of unpleasant dehnquencies. If he were a sergeant or a corporal he doubtless would be broken. But such is the fortunate position of a private, that he cannot be d^aded to an inferior rank. Well he could sUck it. It didn't matter. What reaUy mattered was Jeanne. Was slie in undisputed possession of her packet.' When it was a qu^tion of practical warfare, Doggie had blind faith in his T^^^TT^'S'"' Perhapb even more childlike than u ? ?" leuow-pnvates, for officers were the men who had come through the ordeal in which he had so lamentably failed; but when it came to administrative affairs, he was more critical. He had suffered during his miUtary career from more than one subaltern on whose arid consciousness the brainwave never beat. He had never met even a field omcer before whom, in the reahn of inteUect, he had stood in awe. If any one of those dimly envisaged and still more dimly remembered officers of the Lancashu-e Fusihers had ordered him to stand on his head on top of the parapet, he would have obeyed in cheerful coi^dence; but he was not at aU certain that, m the effort to deliver the packet to Jeanne, they would not make an unholy mess of things. He saw stacks of dirty, yellowish bits of paper, with A. F. No something or the other, floating between r§lu8 and the Lancashire Battalion H. Q. and the Brigade H. Q. and the Divisional H. Q., and so on though the majesty of G. H. Q. to the awful War Ottce itself. In pessumstic mood he thought that with her ienuTlCbfwiLKd*'?^"^^^^ he rememLered the wean, thL 1^ /", '^^°- ^< steamer, which ffi Sed £l?il''(r'r«y.^d tramp of feet thaf nX 1^. .u" "® ^^ rhythmic serfnity wL Ws^l7w'aTruS Krof "'P''' Plex taiigle. It was aU very weU to tW^^nf i °"" Jeanne, whom it was unlikely that F^ of Jeamie, allow him to see aaain Tl ■ >"'<' e^er ended dm-ing hiTlifeffi. ^^^ X^PP^^^'^g the war Peggy, his fuCe S™ho taH i?''t .«^.P«?«y " through good and Srepute^' yi Ipl^ T^'^ - not the faintest shadow of doubfdSut if 'n'*^ kept on frowning at the blue skv Rhit ^°«'° very desirable countrv but in if t^" ^"«^'y ^as a to think. And enS^;<5«fuy°""« 'compelled nuisance The Slstlv tr^nT^ K^f «? '"f^™! points, after dlffle voriL ''"I "^f^. ««^ to think of anvthino. fJ^« I ^ °*** ,'^'«J "Pon better for yo^S ^Vou iulr^/"" '^°^^'' ^' and drank vour tea «nH •• V^ l^"^ bully-beef killed am o^two, a^dlaSr Jr^'-''«"«^ .«"d Now that he ^e t? bok a? h Tn" ''"'■" '^^"• spective. it wasn't at aU a bad hfe W^t' J^ been worried to death n.K^ ^' r^^° had he were his friends- th^\^J^^ "^^ ""''"^ ^d there pavement oi M?ewf^H"°,« ^^' ^« ^•JW spiritual tread rZ^ on ?dd ' flf '^^^' ,^"' ^^««« by the Seer otP^^rZ-'f^efrLVlV^t^ mmiature Hercules whn!' 5? ' ' • ^- the two Roches by the neck and knocked their heads together tiU they died, and who, musically incUned would sit at his, Doggie's, feet while he played on his penny whistle aU the sentimental tunes he had ever heard of; Sergeant Rallmghall, a tower of a man, a champion amateur heavy-weight boxer with a voice compared with which a megaphone sounded hke a maiden s prayer, and a Rardolphian nose and an eagle eye and the heart of a broody hen, who had not only given hun boxing lessons, but had puUed hun through difficult places innumerable and scores of others. He wondered what thev were domg. He also was foohsh enough to wonder whether they missed him, forgetting for the moment tnat It a regnnent took seriously to "missing" their comrades sent to Kmgdom Come or Rhghty, thev wo^d be more like weepmg willows than destroyera M the same, he knew that he would always live m the hearts of two or three of them, and the knowledge brought him considerable comfort. It was stranffe to reahse how the tentacles of his being stretched out gropingly towards these (from S« old Durdjebury pomt of view) impossible friends, tney had grafted themselves on to his Ufe. Or was that a correct way of putting it? Had they not, rather, all grafted themselves on to a common stock of hfe, so that the one common sap ran throuch all their veins? " It took him a long time to get this idea formulated, faxed and accepted. Rut Doggie was not one to boggle at the truth, as he saw it. And this was tne truth. He, James Marmaduke Trevor of Denby Hall, was a Tommy of the Tommies. He had lived the Tommy Ufe intensely. He was living It now. And the extraordinary part of it -vas that he didn t want to be anything else but a Tommy, from the social or gregarious point of view his Ufe But H^^''"" ^"g"^'" ^^ ««id half aloud, hefgi trprSSeS'' ^ ^^though "he was Office Ration R2T„r1 •?'?"^ ^^^ War strength of st^lcabh^ vJ? Z'"'^^ '°™1 « the containing a form of Will on the right band flap, and on the left the direcUons for the making of the will, concluding with the world-famous typical signature of Thomas Atkins. Then, duty accomplished, he reconciled himself to the comer of Fauyland in which he had awoke that mommg. Things must take their course, and while the^ were taking it, why worry? So long as they didnt commit the outrage of giving him buUy-^f for dumer, the present coohiess and comtoit siunced for his happiness. Morin, of^L ^J'® independent of Aunt Jeanne's loyd^tii„'n'fhftt'°°.i^ spite of opinion. Now roM Wl^ °M ^"* « P«>r she liked, andl much th^Wt T^^ ^^ whenwr would the^L^r^ frS^"^l°^f^«°°e- Jeanne from dre^ UtUe Fr^C ^^ "^^althy /ick room. Jourdain spoke prose, mns k savoir. Without knowing it, he would have gone to the ends of the earth for Jeanne, have clubbed over the head any fellow savage who should seek to rob him of Jeanne. It did not occur to him that savage mstinct had ah-eady sent him into the jaws of Death solely m order to estabUsh his primitive man's ownership of Jeanne. When he came to reflect, in his Doggie-ish way, on the motives of his exploit, he was somewhat baffled. Jeanne, with her tragic face, and her tragic history, and her steadfast soul shining out of her eyes, was the most wonderful woman he had ever jiet. She personified the heroic womanhood of France. The foul invader had robbed her of her family and her patrimony. The dead were dead and could not be restored; but the material wealth, God — who else? -^ had given him this miraculous chance to recover; and he had recovered it. National pride helped to confuse issues. He, an EngUshman, had saved this heroic daughter of France from poverty. . . . If only he could have won back to his own trench, and, later, when the company returned to Frfilus, he could have handed her the packet and seen thlight come into those wonderful eyes! Anyhow she had received it. She sent him u thousand thanks. How did she look, what did she say when she cut the string and undid the seals and found her Uttle fortune? Translate Jeanne into a princess, the dirty waterproof package into a golden casket, himself into a knight disguised as a Squire of low degree, and what more could you want for a first class fairytale.' The idea struck Doggie at the moment of hj;hts out," and he laughed aloud. address was £ a bold femint^ifT'"'^- '^'^ ^^ could it I^CjeSieP^A'i^- ' "'^hom lous leap, and he C the " veSfo^ra^ h"'^''"; 2«\ertom open envelope of pj^'s^^ ^t ^fl' first two words the learseem^^ K. •** ^® "The military auihoriiies have remitted into my pot$es»ion the package which you to heroically retcued from the well of the farm of La Folette. It contain all that my father wot able to save of his fortune, and on consultation with Mattre Pipineau here, it appears that I have sufficient to live modestlj for the rest of my life. For the marvellous devotion of you. Monsieur, an English gentleman, to the poor interest of an obscure young French girl, I can never he sufficiently grateful. There will never he a prayer of mine, until I die, in which you will not he mentioned. To me it will he always a symbolic act of your chivalrous England in tht aid of my heloved France. That you have been wounded in this noble and selfless enterprise, is to me a subject both of pride and terrifying dismay. I am moved to the depths of my being. But I have been assured, and your telegram confirms the assurance, thai your wound is not dangerous. If you had been killea while rendering me this wonderful service, or incapacitoted so that you could no tonger strike a blow for your country and mine, I should never have forgiven myhelf. I should have fell that I had robbed France of a heroic defender. I pray God that you may soon recover, ana in fighting once more against our common enemy, you may wm the ghry thai no English soldier can deserve more than you. Forgive me if I express badly the emotions which overwnebn me. It is impossible that we shall meet again. One of the few English novels I have tried to read k coups de dictionnaire, was ' Ships that Pass in the Night.' In spite of the great thing that you have done for me, it is inevitoble that we should be such passing vessels. It is life. If, as I shall ceaselessly pray, you survive this terrible war, you will follow your destiny^ as an Englishman of high positwn ana I that which God marks out for me. What rubbish are you lalking about my social position? My father was an English parson (pasteur anglais), and yours a French lawyer. If I have a little money of my own, so have you. And we are not ships, and we have not passed in the night. And that we should not meet again is not Life. It is absurdity. Peggv was there. She had arrived from Durdlebury all alone, the night before, and was putting up at an hotel. "Till three o^clock, then. With love from To write the answer he had to strip from the pad the page on which he had begun the letter to Jeanne. He wrote: "Dearest Peggy." Then the pencil point's impress through the thm paper stared at him. Ahnost every word was decipherable. Recklessly he tore the pad in half and on a virgin page scribbled his message to Peggy. The nurse departed with it. He took up the flimsy sheet containiug his interrupted letter to Jeanne and glanced at it in dismay. For the first time it struck on the table Krb^"^L^.° P"* ^« handful it on the floor.^ m^Ch^}^ T."^^ ''°PP«d of the hard-workS 3 ^' """""^ ^« J"* 'ath from her pcS^S m^th^r 'r^. t^?« Let him^t out ^^' f«!^ •^i''''^?''y^Penea? struckupadavorwff^ judicially. Tfily had him. as X mighThrve iw ^J ^^« l^ told sad and romS sto^' t /Jr^n ^'^' "«' • • • She ffi a?S^„S Sy fi^ ^P^=Twas one of the few nrivntT c^iJ^ u because he her language^ Uwmhut ^^^"^^ it ^."^^ ^P^^k teU hmTof^L suS^ilket It wa\ ^' ,°^'' treasure, would, of absolute certainty, have done exactly what he. Doggie, had done. Supposing Mo Shendiah had been the privileged person. Instead of himself. What, by way of thanlrs, could Jeanne have wntten? A letter practically identical. PracUcaUy. A very comfortable sort of word: but Doggies culUvated mind disliked it. It was a slovenly word, a make-shift for the hard broom of clean thought. This infernal "practicaUy" beijBed the whole question. Jeanne would not have wntunentalised to Mo Shendish about ships passing m lie night. No, she wouldn't, in spite of all hu eflorts to persuade himself that she would. Well perhaps dear old Mo was a rough, uneducated sort 01 chap. He could not have established with Jeanne such dehcate relations of friendship as exist between social equals. Obviously the finer shades 01 her letter would have varied according to the personahty of the recipient. Jeanne and^himself owing to the abnormal conditions of war, had suddenly became very intimate friends. The war as she unagmed, must part them for ever. She bade him a toucWnff and dignified farewell, and that was the end of the matter. It had all been an idylhc epiKKle: begmning, middle and end; neatly rounded off; a thing done, and done with — except as a strange romantic memory. It was aU over. t^r^^u^ ^ remained in the Army, a condition lor which, as a pnvate soldier, he was not responsible, how could he see Jeanne again? By the time he re-joiMd the regunent would be many miles awav from FreliM. hs, in her clear, steady way. she redised. Her letter must be final. tJi^doS?^ ^''- Was not Peggy coming at Again Doggie thought, somewhat wistfully, of the ..P«»«ry stood for a moment at ih^ a the ward; then, perceivW h; J! u ^'^'', ^canmng with defiant rf a Z^ L^^?"'^'''^ ''"^o comrade, anl men in b^„,^f Wu^-unifonned a^a chai, and^SJiia^'^ t^^^S seeks to cover ahynei '^l^hin T ^^ ""i^ ^^at gone fut andcan'i^Vel and n«^ '°""- • ^°^«''8 paraons- shows in S^ distort O.h"^"^ ^ "^^ them wodd have come to^ " " 0^«"^'«' one of Peggy drew a little breaUi of astonishment and " "? on her chair. His surprising statement ■eemed to have broken up the atmosphere of restramt. Conscientious Doggie knitted his brows. A fervent Yes • would proclaim him a modem Paladin eager to slay Huns. Now, as a patriotic Englishman, he loved Huns to be slain, but as the suirivor of James Marmaduke Trevor, dUettante expert on the theorbo and the viol da gamba and owner of the peacock and ivory room in Denby Hall, to say nothing of the collector of little china d&gs, he could not honestly declare that he enjoyed the various processes of slayirg them. "I can't explain, ' he replied after a while. " When 1 was out, I thought I hated every minute of it. Now I look back, ffind I've had quite a good time. 1 ve not once really been sick or sorry. For instance, ive often thought myself beastly miserable with wet and mud and east wind — but I've never had even a cold in the head. I never knew how good It was U. feel fit. And there are other thmm. When I left Durdlebury, I hadn't a man friend in the world. Now I have a lot of wonderful pala who wodd go through HeU for one another — and. lor me. "You mean gentlemen in the ranks?" Not a bit of it. Or yes. All are gentlemen in tne ranks. All sorts and conditions of men. The man whom I honour and love more than anyone else, comes from a fish-shop in Hackney. That's the fascmating part of it. Do underatand me, ^??^' i.''* continued, after a short silence dnrin. whK^ she regarded him ahnost uncoi^Sfih? I don t say Im yearning to sleep in a iSlhy dSl" or to waUow m the ground under sheU-fi^ o" mv: thing of that sort. That's beastly. TWe's ^v one other word for it, which bemii with TL = ^ letter, and the.superior Und ot^y^^^^dll^^ It m ladies' soriety. ... But wtile I'm Sg L^ they^r^l^^^Lf ^^' other feUows are'Zi"-!: o7.?^h» °^ chaps -real, true, clean men- Zt k iL^r "*? '" »^J ^ essenUalT-Sf the PMt 18 leather and prunella -and I want to be back among them apn. Why should iTL clove? S^iS^^ ^S^ '^-^ - « '0 °^ i' eomS '•How horridl" cried Peggy with a little shiver. Of course It's homd. But they've got to stick H, haven t theyP And then there^s an^er t£ Out there one hasn't any worries " ^^' kiiS^FwoS^r ""' ^" ""• "^«--^ What te^offel.'"^" ""^'''"' °^ indiscretion. He int'lfct"" '^'^t- ^^fy ""^ ^'th a sort of trained he felt conscious of something lacking in W bTue UMmihng perfunctoriness of the nurse; m art ^ ♦''k^ not of tenderness. As she bkw oTt ^e match, which she did with an odd air oFdeuLra! tion, her face wore the same expression of hardness It had done on that memorable day when she had refused him her sympathy over the white feather mcident. Peggy reflected. Yes. There v/as some truth in that. But she thought it rather hard lines on the wounded to be sent back as soon as they were patched up. Most of them hated the prospect. That was why she couldn't imderstand DoKjrie's desire. ° "Aiiyhow, it's jolly noble of you, dear old thing," she declared with rather a spasmodic change of manner, "and I'm very proud or you." "For God's sake, don t go imagining me a hero," cned Doggie in alarm; "for I'm not. The only reason I don't run away is because I can't. It would be far more dangerous than standing still. It would mean an officer's bullet through my head at once." question had come at last. "I just got sniped when I was out, at night, with a wmng party," he said hurriedly. "But thats no description at all," she objected 'I'm afraid it's all I can give," Doggie replied. Ihen, bv way of salve to a sensitive conscience, he added: There was nothing brave or heroic about It, at all —just a silly accident. It was as safe as tymg up hollyhocks in a garden. She would «ifT!f- ? j^^ relations with one of the world's great cynics in liis advice to a youmf man: "If you care for happine^ n^" sp^ to a woman about another wom^ " Uoggie felt uncomfortable as he looked infr. Peggy's clear blue eyes; not conscienciXfcken S the reahsauon of himself as a scoundrelly Don Juan -^at never entered his ingenuous mind; but he hated his enforced departure from veracity ThI one virtue that had dragged the toy Pom succe^! fuUy along the Rough Road of the soldier's Itfe^ his uncompromismg attitude to Truth. It \^ him a sharp struggle with his soul to reply to Peggy - "' f ^K«T ' M? °°'', ~> * ^«y- I don't know." J„«t .1* ^1"" f-"'^ ^°^ t>ere, after the war just as though nothing had happened." ' t«it^ 1 * "i,' ?^^ '^^Jied. "Dad's always taUuM learnedly about aocifQ reconstruction, whai ever that means. But if people have got money and position and aU that sort of thing, who's S to take It away from them? You don't suS we re all going to turn socialists and pool the wS of the country and everybody's going to live in a gard^-city and wear sandals and eat nuts? " Of course not," said Doggie. Uoggie ht another cigarette, cliiefly in order to gam tmie for thought; but ai odd Ltinrmad^ bun secure the matchbox before he picked out the mcontrovertjble. Unfess there happened some wn^iJ-''?'^^?°t.'°^°''^» « °«^Jy democratised world m ghastly chaos which, after ai, was a remote possibihty, the ertemals of gentle life would undergo very shght modification, f et there was someS fundamentally wrong in Peggy's conception of ^t-war existence. Something wrong in ^ntiak. INow, a critical attitude towards Peggy, whose KwT T. ?'~^ °^ ^«' «P'«^<J^d Wy. «eem^ natetm. But there was something wrong, all the e^e. bomethmg wrong in Peggy herself that put her mto opposition. In one aspect, she was the 11^,^ ^^J r^J'F «=" a^d dried littie social ambitions, and hpr depute projects of attainment; but m another she was not. The pre-war Peggy bad swiftiy turned into the patriotic English girl who had hounded him into die aimy. He foimd ^nself face to face with an amorphous, characterless sort of Peggy whom he did not know. It was paplexmg, baffling. Before he could foimulate an idea, she went on: Dogrie shook his head. "No one can go through It, redly go Uirough it, and come back the same ^ lou don t msinuate that Ohver hasn't reallv gone through it?" ' M. C. s about hke Iron Crosses. In order to Bet it Ohver must have looked into the jaws of leU. Ibey all do. But no man is the same afterwards. Ohver has what the French call panacAc—" ^^ What's panache ?" ai,r^''"i''"? *?^ through your hat, Mannaduke," sne exclaimed with some irritation. "Oliver's a straight, clean, English soldier." the whole of civilisatirm ;= ikT- ^ •-• ' ,^® ^o^d. Christmas pudff^T^p\^V^«. «'"?' »P like a the trend of TLn^ thSt ^^"^ ^ ''^^^e get to learn it ioZr o^dL R„t • ^ J^°; ^^ superior wisdom, I w1^ A" ""X S/°'^ there won t be a hit nf „v.„^ ° V. ^"ter the war be a duke Mid a c<Zl^ "^' '^^^- ^ ^"^^ will mam a dukp h.,f kT^ ^x^' ^''^ ^'il'e may reoHh^b Hp"ii fi -Tk" ^, ""''^ « little tin gcS dem^^fc Tj^'^ ^l^ the position i a Sx •^"* ^^° »»« t^o there'U be any old sort FraMi^?'^"" '«a™ aU this horrible, rank socialism in "Perhaps, but it seems so obvious." Its only because you've been living among She cried out indignantly. "Indeed we're not. Tlie newspapers come to Durdlebury, don't they? And everybodyTdoing somethmg. Wehave the war aU arouid us Wevf Cottage Hospital. Nancy Murdoch is a V A D and scrubs floora. Cissy James is driving a Y.M C a' motor car m Calais. Jane Brown-Gore is nureing mSdonAa. We read all their letter. Peraonauf I can t do much because mother has crocked up and I ve got to run the Deanery. But I'm slaving from mommB to night. Only 4t week I got upi concert for ^,e wounded. Alone I did it-anTi? takes some doing m Durdlebury, now that you're Z^uZ^ the M^sic^l.AssociatU has perished ™f mamtion. Old Dr. Fhnt's no earthly ^, since Tom, the eldest son, you remember, w^ killed in Mesopotamia. So I did it all. and t wasTgreS £? .r;.. ^ .whenever I can get a chance, I gb round the hospital and talk and .lad to the men aS TOte their letters, and hear of everything. tone: 3 on^^'Don'? v^^ t°^/^ ? '^'>'^^ to have thk pifflW aJiS^hi^nS-"*"'' "'^^^^ this long way tose^y^?^'" ^^'"' ^ ^« «>'°e «« 'Yes ; I'D come this time." said Doggie. So he promised, and the talk drifted nn to casual ta... Slie ga ve iinn the mild chronicle of th^ Sv described plays which she had ^ on^^ And m the meanwhile," she remarked "fr« ♦« get these morbid ideas out of you^^SSad ^ hJr ""^ '"^ P-ting/she ^'rd'ahook gloomy Penworthv^ J ** ^^^^ «P'dJy- The true. dS wSd r??.^''^"u°" ''^d not come wooden Iw- but rn on" '!^?, '^u* at ease on a last word of the epS had^nt^ W'^ '* »>« to Pe^gy forbade iffirlhou^hfW- ^^^^'V must henceforward S of Pp!^ °' A^^- "e faithfuhiess as hard aThp 1 i5^^r>"°'' ''er sturdy thought, the S remotTdS P^" ^" "»'« ^^ course the pubLcitv of th» • « ?^»«y ^eem. Of it with a ceK SnsfraS Tn^L'!! ^'^ ^^^^ approach to senti^mZv ' ,'^°''^^ "» of it any not even kissed Tbey had ^r^T^^l' P^^^ h«d arguing from differem SK^"" ""i^^ time been near to quaireUi^ h 1 ^^''- ^^^ had him to criticise fierT^et how I.^.^'k ""t^geous of mere fact of strivS; to 6x1.^1,^ "^ ^^ ''^'P '? The Indeed they were fi,r 1 ^f"^ "^f ' ^ ''"ticism. soulofDogJf/theTari^„^^"t- ^ntp the sensitive The soul If pS7 had S '"• '^^T^ ^^^ Passed, her, in her she& cto 7^„ JtoucheS. To ghastly accident like « r«fi„ ^»» ?nd, ,t was a the traffic on y^ertlol^Zl 'trV'^"^ her own dam who took part in it. it was a brave adventure: for Uie comnJon soldier a 8ad but^ taouc necessity. If circumstances hadX^^ ^ FwJ^X. 1 \f>^oa tenmnus. or motor driver in JTance, her homon would have broadened H.^ ^e contact with realities mto whiTher dUett^S make the deep unpression. In her heart, aslar m b-^use It mterfenxl with her own definitely markS out scheme of existence. The war over^e Wo^ regard .t politely as a tJiing that had never IZ and would forthwith set to work uf«n hw aS said interrupted plan. And towards a compreK dTJ ^,!SP^il^^'^'^»y he Pe-^lexed Tnd of "Our unsophisticated friend. Mo, and mvself anmitingthisqter together, and he bikme hSuZ ^ying that he hopeslt finds you as if leav^us^LseS m a muck of Just and perspiration. WheVemwi mw I must not tell, for (in the opinion ofTe C^rZ) yoiujoald reveal it to the Very ie^rend^ C bJ^% Durdlebury who would naturally telegraph i^ iZ &r w ^ ^"T- . '««' a^DivSw^is M far ijZSl- ^y"'' M i y"' <^«w. «'«' there is fcfooA- figMing ahead of us. And though the hearts of Mo and me go out to you, laddie, Zi Ziwhw^ miss you sore, yet Mo sa/s he's Uist^ri^ gj^y^^ position and yow wor^l^^ ' ' ■^'. n"' Pritale you hod_ left ler eZd^ if^ , '■/';•:?': ""« my native ScoUM caution m\ , v'/. . / '^ human nature gained inthi Z ■ '^ ^ :«H V the blazes teas the Frem-h t,.T^u' h ^ ^^^ has a pern^iouieffZl^nJS ?^'°'»-«»o'^' The war limes ^nsZdlS£rZ,T * "^T^ ~ ^ 'ome- ««nr why I havi inTitJyou. ^B^^l KZ "^^ understand. It is the onlviJ^i hZt t l "'"* ^" Doggie's friends aTfoHvLVtl. "/ H"'^ «"' anring the attack on the wiring party. ,«k / "H,?-??^> ''^^' «»«'« «« «e tte Scott wha hae wi' Wallop bled, and are going toZr^ bf or to victory. Possibly both. BatlwiuZ^n st^fast to my philosophy , and if I amc^rl^t Unsaid sanguinoUnt coach, I will do my besltoTi„ "Mo, to whom I have read the last paragraph savs ^•ifT'i.'^ '^^ ^ddication aff^^b^' WM which incontrovertible propos&nZJmrM^ love, I now conclude this epistle. "' " m^^!^^ ^^? imbecflesl" Doggie cried aloud. Why the iinpnntable unprintaSlness coulda't Phineas mmd his omi business? Why had hSn his Billy accident of fortune awav in thia^h.l^;!? two friends werTT thp.V ,2^ '^^- ^»t'» of his with his woSd" J^e'^ttV""^: ^ '-« steel-true to him. It W^^Ut V^^ c ."".^ were to foment thH^p^L^ i^J^^^^ ^^^ %alty and hiinself: ™^Sr JTf^^ ^^t^^en j4me Frelus, the two idSfa ^!!h L*"?™- '"^'^ °«w at with the smirki^ SSt,i«^'"^«<^^«"y schoolgirls. So Dn^^ f "™^ of a pair of After^ what did ifmat/err' ^^ ^^-»- sui?<rfte[!Sft"f ^;^duecou,«e. A HereceiSs^Jere th^L'^.f .«»«.hpspital blue. and his railway S.^.^tW^''^^"'°"«h. it for many months. He laughed. "Haven't got any, thank God I If you knew what it was to hunch a horrible canvas sausage of kit about, you'd appreciate feeling free." , ''It's a mercy you've got Peddle," said Peggy. He has been at the Deanery fixing things up for you for the last two days." ''Who s going to start the car?" she asked. Oh, Lordl" he cried, and bolted out and turned the crank. "I'm awfully sorry," he added, when, the engme runnmg, he resumed his place. "I had forgotten all about these pretty things. Out there a car is a sacred chariot set apart for gods in brass hats, and the ordinary Tommy looks on them with awe and reverence." ' OUver's here, with his man Chipmimk," she remarked, her eyes on the road. • 3,',^'^^®'''* 0° leave again? How has he managed staying with us. He laughed at the queer little social problem that seemed to be worrying her. "I think you'll find blood is thicker than military etiquette. After all, Ohver's my first cousin. If he cant get on with me. They swept through.the familiar old-world streets, which, now that the early frenzy of mobilisinif lemtonals and training of new Annies was ovct had r^umed more or less their pre-war appearance! The deepy meadows by the river, once ground mto black slush by guns and ammunition waggons and horses, were now green again and idle, and the troops once billeted on the citizens had marched Heaven knows whither — many to Heaven itself — or whatever Paradise is reserved for the greathearted Enghshfiehting man who has given Ks life lor Hjigland. Only here and there a stray soldier on leave, or one of the convalescents from the cotUge hospital, struck an incongruous note of war. Ihey drew up at the door of the Deanery under the shadow of the grey cathedral. "T^ank God that is out of reach of the Boche " said Doggie, regarding it with a new sense of its beau^ and spu-itual significance. "To thmk of it like Rheims or Arras— I've seen Arras — seen a ^ell burst among the still standing ruins. Oh f^eggy — " he gripped her arm —"you dear people haven t the remotest conception of what it afl is — what France has suffered. Imagme this mass of wonder all one horrible stone pie, without a trace of vFhat it once had been." "I suppose we're jolly lucky," she replied. The door was opened by the old bufler, who had been on the alert for the arrival. round to the yard. So Doggie, with a smile and a word of greetinir, entered ^e Deanery. His uncle appeared in^e baU Uorid, whitehau-ed, benevolent, and extended Dotn hands to the home-come warrior. S 1°^^".^ K^ y'"- ^^ ' «'"''' have sparSX time. I should have run up north, but Fve not a minute to caU my own. ^e're doing oiili^e of He put his hand affectionately on Doeirie's arm ^«'.r;i:^ the drawing-room'^door. p3ed hto m and stood, m his kind, courtly way, until t^ {:°«T^^^J^'^•"'H ^^«' cake-stfnd St hf had returned to some forgotten former in^ation Tie dehcate duna cup in his hand seemed tooXu tJ^^fi^"^"^^ «f "f«' »nd he feared iTst he should break it with rough handling. OldhaWt however, prevailed, and no one notic^ bki^ot o i„it" ,*, ''^ ''^'* °o^' said Oliver. asked Doggie Rather. We broke through all riX Th^n machine guns which we had overlooked Jnt ,!?! Jeback Luckily they were s^ St' a and 5^nAP"^™V T° ^ 't bad moulded Dogrie^ And Doggie, who had learned many of the l3n» in hmnan psychology which the A^ny teS bc.om of their awn family, but that he would have U. ited much the same any Tommy into whose compamonship he had been casually thrown. T^ Tommy would have said "Sir" very scrupulously, whidi on DogKie's part would have teen ^ idiotic tew t Ji % r^^ ^«^^ 8«t °n famously fewethw. bc.ad by the freemasonry of fighting men who had cuK tie same foe for die saie reasons by hw men, t id his heart went out to him. Ive brought Clupmunk over," said Oliver. hL I T^°^' the freakP The poor devil hZn't inlf •t'"U.^'"r {?u" «^"Pl« "fyears. Didn't want It. ^y should he go and waste money in a ajunb^ where he didn't know a human Ltag? But thB tune I've fcced it up for him, and his leafe v^nTirlT"''"!'"^, T^^- "« '•as been my serhp°H ^ ^f "«•• J/ ^^^ ^^ ^^ a^ay from me, i f^ ^^^^' °^ '^'^^^^^ '"' C- O- He's policy. ^^ °^ soldier?" the Dean asked "All nght, Peddle," he lauehed "If ;tv iwP^gy-s decree, I'U change. rTgotaU I w^t "^ Are you sure you can manage. sirT^ Peddle "That's 80," said Dog^e. "And it's martyrdom compared with what it is in the trenches. There we always have a Mtgor-General to lace up our boots, and a Field-Maruial's always hovering round to light our cigarettes." Pwldle, who had never known him to jest, or his father before him, went out in a muddled frame of mind, leaving Doggie to struggle into his drees trousers as best he might. djt my waistcoat down the bacL pL Cd fedd^2 wiU have an apopleptic fit when he^ it iv! qwn a bit aince^thL elegan? ™«SVr made'4' yifaut wuffrirpow Hre beau," said Peirirv the front, they want to see their womenfolk looking pretty and dainty. That's what they've come over for. It's part of the cure. 'A treat for tired eyes.' I'll rub it into Dad hard." Oliver laughed. "Where the dinner kit I bought when I came home is now, God only can tell." He turned to Peggy. "I did change, you know." "TTiat's the pull of being a beastly Major," said Doggie. "They have heaps of suits. On the march, there are motor lorries full of them. It's the scandal of the army. The wretched Tommy has but one suit to his name. That's why, sir, I've taken the liberty of appearing before you in outgrown mufti." ■Then the Dean and Mrs. Conover entered, and soon they went in to dinner. It was for Doggie the most pleasant of meals. He had the superbly healthy man's whole-hearted or whole-stomached appreciation of unaccustomed good foodjand drink: so much so, that when the Dean, after agonies of thwarted mastication, said gently to his wtfe: "My dear, don't you think you might speak a word in season to Peck" — Peck being the butcher — "and, forbid him, under the Defence of the Reahn Act, if you like, to deliver to us in the evening as lamb that which was in the morning a lusty sheep?" he stared at the good old man as though he were ViteUius in person. Tough? It was Uke milkfatted baby. He was already devouring, like Oliver, his second helping. Then the Dean, pledging him and Oliver in champagne, apologised: "I'm sorry, my dear boys, the 1904 has run out and there's nla„^ T' , .?™<»t intoxicatins' atmosDhere of peace and gentle living. The fuU, lovZ Sme ahuung from the eye of the kind old DeZ hL 3e likStuL^T^ «PP'«=»t«l Oliver's comradeUKe attitude. It was a recognition of him as a mM ^d a_soldier. In the cou«e of dimier taSk K S^ntT" f"^!.^ ^-^ """"J' sh^k hin to the depths of his sensitive nature. The man who despises the petty feelings and frailt^^ of Cildnd IS doomed to remain^ful ipiorancTof th^t^h w of beauty and pathos in tSe lives of his feUow- But to Doggie «ie supreme joy of the evening was the knowledge that he had made good in thee^erS Ohver Ohver wore on his tunic the white mauve and white nbbon of the Mihtary Cross. Hono^ where honour was due. But he. Doggie, had been JnlT^^R^ made me squirm at the idea of scooping out Boches' msides with bayonets " ^ And you've learned not to squirm, so we're Oliver looked at him squarely. thI7l^Hf^""^ i T"]'' ^"^ y°» °°^ If I said that I did. He laughed, stretched himself on his chair, thrustmg both fiands into his trouser pc^kefe! only real fnends I've ever made in my life are Tommies. I ve found real things as a Tommy, and 1 m not gomg to start aU over again to find them m another capacity." Ohver objected. ■j"^u' ^^' { ^ouJd- I^on't run away with the Idea that I ve been turned by a miracle into a brawny hero. I am t anything of the sort. To have to lead men mto action would be a holy terror. The old dread of seeking new paths stiU acts, you see. I'm the same Doggie that wouldn't go out to Huaheine with you. Only now I'm a private and I'm used to It. 1 love It, and I'm not going to change to the end ot toe whole gory business. Of course Peggy doesnthkeit, he added after a sip of wine. "But I can t help that. It's a matter of temperament and conscience — m a way, a matter of honour." Ohver. iiri-'^^T^ ^ explain. It's somehow this way. When 1 came to my senses after being chucked for incompetence — ihat was the woi-sl hell I ever went through m my life — and I enlisted, I swore that I would stick to it a Tommy without anybody's sympathy, least of all that of the folks here. And then I swore I'd make good to myself as a Tommy I was jiMt beginning to feel happier when that mfemal Boche smper knocked me out for a time, ho Peggy or no Peggy, I'm going through with it. 1 suppose I m telhng you all this because I should like you to know." He pasMd his hand, in the famiUar gesture, from back to front of his short-cropped hair. Oliver Milled at the reminiscence of the old disturbed Uofirgie; but Le said very gravely: Do?gLr^ee^"SerreA Wood to rush to held him. The tVue ^S to^ ^°^ ^ impufeive confession of Jel^r'' Th. 1?"""^°° r"^ be a of Fj^lus swam before SlyT'u^ J^' ^'^''^ his chair again with a laS ^^ '"' hea,?^telk:'"rrmat£"^f7^ rJ^^' h««rt-tomyself. It's^d Tu^i^T' ^ ^ I said it words. Anyhow vo?,VptK ^"^\"s«l the same has hit on t^r^r^'L^ fj^"" ^^^^^^o mg one's soul is a Wt W^w^.?°^?^- ^^daboutthesizeofit." '"e'»-f«l"tm -but that's I wish I were a young man," said the Dean, moymg from the door, and with his courtly gesture mvitmg them to sit, "and could take part in these strange hardships. This question of night attire for mstance, has never struck me before. The whole tW is of amazing interest. Ah! what it is to be old! If I were young, I should be with you, cloth or no cloth, in the trenches. I hope both of you know that I vehemently dissent from the bishops who prohibit the younger clergy from taking their place in the fighting line. If G6d'8 archangels imd angels themselves took up the sword agamst the Powers of Darkness, surely a stalwart younu curate of the Church of England would find his vocation m warring with rifle and bayonet against the proclaimed enemies of God and mankind?" The Dean sighed. The Dean sighed. Five-and-thirty years ago, when he had set aU Durdlebury by the ears, he m«ht have preached glorious heresy and heroic schism; but now at seventy the immutability of the great grey fabnc had become part of his being. .'.'Sf } ,^^" °''' f;'"?'" ^aJ! Oliver. ..One of the best," said Dopgie. its rather patietic," said OUver. "In his heart he would hke to play the devU with the Bishops and kick every able-bodied parson into the trenchw — and there are thousands of them that don't need any kicking and, on the contrary, have been kicked back; but he has become half petrified in the atmosphere of this place. It's lovely to come to as a sort of funk-hole of peace — but my holy Aunt! "Oh I "said Ohver, and he grinned. "Anyway. 1 was only goma; to remark that if I thought I was gomg to spend the rest of my Ufa here, I'd paint the town vennilhon for a week and then cut my throat." "It has," said Ohver. "But I never expectci to hear Huaheme called Durdlebury by you, Doge • Oh, Lord! I must have another dnnk. Where's your glass? Say when?" TTiey parted for the night the best of friends. Dogpe, m spite of the silk pyjamas and the soft bed and the blazmg fire in his room — he stripped back the hght excluding curtains forgetful of defence of the Realm Acts, and opened all the wmdows wide, to the horror of Peddle in the mommg — slept hke an unperturbed dormouse. When understand? Im a private soldier. I've ^t to wear uniform all the time, and I'll h«vp tl .^ • ^ ^nf i,y ^d «.iiJ you 'geUt for me " " "^"^ '^ Peddle fled. The picture that he left nn nn„„n-«'<. ^ was that of the faithful st^wd &Sf'^« upbfted hands, retu-ing from the room in m^nf H?« great scenes of Hogarth's "Rake'sTo^t^ '•'^'i^e sunihtude made him laugh -for oZrio' always had a savmg sense of humour -but hf was ve^ angry with l^eddle, while he stamp^lrS Ib^ room m his silk pyjamas. He dipped Jus shavuig brush into the hot water. Thei^ threw It anyhow, across the room. Instead of shavmg he wodd be floating over the idea of cutUng that oTd fool Peddlers throat, and therefore woulS slash his own face to biU. in ^ff' I'o^e^ej-^^ere not done at lightnmg speed w » ^Ti'y of Durdlebury. The &st st^ps^ ?l«n ° ^^ ^''" ^ ^""^ the uniform to the S^t^K"' soon Peddle reappeared carrying ';ThMe too, sir?" he asked exhibiting the latter i«agnedly, and casting a sad glance atthe neat pair ?«^"?- ^'f e?^tely polished and beautif{iSy treed which he harfput out for his master's wear. Hi^^™^ ^^ old man, dressed, and went downstair,. The Dean had breakfasted at seven. Pesgy and OhvCT were not yet down for the nine o dock meal. Doggie strolled about the garden and sauntered round to the stable-yard. There he encountered Chipmunk in his shirt-sleeves, sitting on a packmg case and poUshing Oliver's leggings! hLl^'^v. ^y* «'r^-«haven mug and scoX beneath his bushy eyebrows at the newcomer. Mommg, ^matel' said Doggie pleasantly. Morrjng, said Chipmunk, resuming his work. had never before Wnt^^t^^ Ik ?^ "™y- »" tame gentleman pri^ate^lT^lI!'^K^'"« « '«" to heU on that acK VS^fiT ^'" S^naigned oneof hisraresudSi'^ ^ '"^' '«^«° l>y veS^arSjtotn'^'^^r-^'^ l-^^d been suc^eded.^ SmuS wenff '^'"' ^^J^""'' have bombed. It wrh? S^" ^nlf "' ''"•' ^'^ nish that did it n^J^ j ^' unscientific fi8J?^n graid -sujy '^^'^^ ^ P««trate in moments SrstS^dSedT.^^.'^r^'^' ^^ich tary discipline. ad^Sl L^^t f ^■'^' °>^strode hurfiedi; away ^^ '*' '• OJi'-^^r Chipmmik looked uncertainly into Doggie's eyes for what Doggie felt to be a very long time. The man opposite to him was his master's cousin. When he had last seen him, he had no title to be called a man at aU. His vocabulary volcanically rich, but otherwise limited, had not been able to express him in adequate terms of contempt and derision. Now behold him masquerading as a private. Wounded. But any fool could get wounded. Behold him further coming down from the social heights whereon his master dwelt, to take a rise out of him, Chipmunk. In selfndefence he had taken the obvious course. He had told him to go to hell. Then the important things had happened. Not the effeminate gentleman but someone very much like the common Tommy of his acquaintance, had responded. And he had further responded with the familiar vigour but unwonted science of the rank and file. He had also stood at attention and saluted and obeyed like any common Tommy, when the Major appeared. The last fact appealed to him, perhaps, as much as the one more mvested in violence. Oliver in convulsive laughter. "Oh, my holy Aunt I you'll be the death of me, Doggie. 'Yes, sirl'" He mimicked him. "The perfect Tommy. After doing in old Chipmunk. Chipmunk with the strength of a gorilla and the courage of a lion. I just happened round to see him said Ohver. Long ago, when I used to crab you, she gave it to me in the neck; and now when I trjr^ to boost you, you seem to get it." "I'm rfrad I've got on Peggy's nerves," said Doggie. You see, we've only met once before dur>n§,the last two years, and I suppose I've changed." There^ no doubt about that, old son," said Ohver. "But all the same, Peggy has stood by you Uke a brick, hasn't she?" up his hair. "Why the devil of it?" Ohver asked quickly. Oh, I don't know," rephed Doggie. "As you have once or twice observed, it's a funny old war." He rose, went to the door. "Where are you off to?" asked Oliver. •'I'm going to Denby HaU to take a look round." Like me to come with you? We can borrow the two-seater." Doggie advanced a pace. "You're an awfully good sort, Ohver," he said, touched, "but would you mird — I feel rather a beast — " tiful house was bkomU^h^ spacious, beauhand, as it were Zd Tt^ u u^L'"^^ ^ ^a^e a men and sTi^L^^ i'''"'^ ^ ^^^ ^ith serving he?ef W^m lyA^l't^'- ^-« his being the oriental rugs ZS«t^fr ^^'^^ of it all =^ oak staircase iS'di^ to thl i?^* ?° ^^« °«hle o^ haU furnitCrwSJ n'„t^ sohd historical bered, he would havrfdtUkp« ^''"^^'^ ^^™^'°aU his Ufe to barns L!i; . ® ,™,™ accustomed fetid hol^ £ fcoi wJl1f1,''^«fr^« «"d some illrgua/df^Xr 'hT ^^/^nder^ into room, fhe faitff l^jif^ ^°?5^ the drawing to give him a tn,e SS^^%ir^l\ ITuI behind a cuS^ Hp , ''^^ ^<^^^° '« an alcove on the teuS^ack" of r. K"^t '^^ ""^ '^'^t Chippendale^^ on 1p 1^°^' "^ ^'^^ '=J»«ed collection of SpaJL on^JI^ containing his o- the curtains ^^^^.^^'^f^^^oocH paper which, beguminif to farf,. f»„ now looked mewiamf m!.» • i ^° ^^^ ago. abominable r^^ h oZh^^^T " ^«« «« musk or pastillS or j^^ck^ ^ «?f^? of done so, fSr once he W S' " ?H«ht have sort, and did not renew thi^^v.""™'^* «f the a SHi^'hravSS^l^S.'^^- Vhich for tumea, it impress^^iTirf- ^"* ^^erever he the miserable gS of^L^ ■ "''"sciousness as enormitfes of hum^m kventiof W"' ^ ^^^^^ strous dogs of China nnH if!. Ks^ tn A '''""? r(«'''« had he W.-d his heL-r^J th ^^ ^^^ ^°?«- He had feits. Tb add to hi?^ir?''"P^"^ "'"ote'd^e it, SesXd abo^S'^i, f ^alo^e . it, becile Russian nrinro kIt^ i -^v" e senu-imonce rankS^iKs'Sto^y'^^,, '=^^''=^'' had serious and abso?bq ptS of Wslfe'^^" " '^ fif . u the cabinet stoutly resistins' worked hideous damage on the gilt stool. But Doggie went on bashing till the cabinet sank in ruins and the Uttle does, headier, tad-less, rent in twain, strewed the floor, Ihen Doggie stamped on them with his heavy mumUon boots untU dogs and glass were reduced to powder and the Aubusson carpet cut to pieces Damn the whole infernal place!" cried Dogeie and he heaved a mandohn tied up with disgusSnit peacock-blue nbbons at the boo'icase, and fled irom the room. He stood for a while m the hall shaken with his anger; then mounted the staircase and went into his own bedroom, with the satinwood furniture and Nattier blue hangings. He would have liked to throw bombs mto the nest of efl'eminacy. But his mother had arranged It, so in a way it was immune from his iconoclastic rage. He went down to the dining rwm, helped himself to a whisky and soda from the sideboard, and sat down in the armchau- amidst the scattered newspapers, and held his head in his hands and thought. The house was hateful; all its associations were hatefid If he hved there until he was ninety, ttie abhoned ghost of the pre-war Uttle Doggie Trevor would always haunt every nook and cr^y of the place, moutumg the quarter of a century's diame that had cuhninated in the Great Disgrace At last he brought his hand down with a bane on ihe ann of the chau-. He would never hve m tins House of Dishonour again. Never. He would sell It. He would seU it, as it stood, lock, stock and barrel, with everything in it. He would wipe out at one stroke the whole of his unedifying hL had ever heard him laugh like that Af.'o u^® he was even surprised at £elf ^^^^ « ^^^^ He was perfectly ready to marrv Pp^itv u was ahnost a pre^rdain^ thing.^ 3e 5 the engagement was unthinkable. He^^o^dp,^ atmg loyalty bound him by every fibre ofm^I^" Sould knor"i- ^"* i' "^« e^^tiaJ Lf P^^a&ouid know whom and what she was marrv^V^ The Doggie trailing in her wake no Tonge^^St^' well U'LLS^'P??'^ ^ 1«"«^ ^« nfw CgS Trevor immediately. He would start at once DMgie went out and sat on the front doorstep and anoked cigarettes tiU he came. ^ Mr. Spooner," said he, as soon as the elderlv auctioneer descended from his little car, "I'm coine ^A^'' ''¥' «f the Denby HaU estate. Cd with the exception of a few odds and ends, family w1 '^^ IZ ^'^' ''^''> ^'" ?•'='' «"t. «11 the conSo A%u°,}^' f"™t«ire, pictures, sheets, towels and kitchen clutter. I've only got si:^ days leave, and I want aU the worries, as far as I wa concerned, settled and done with before I jro &» youU have to buck up. Mr. Spooner. If you and assemble his business wits MT%r^^ J'" T^ ,°" y^"' histnictions, Mr. Trevor, he said at last. "You can safelv leave the matter in our hands. But, ZthouA It is agamst my business mterests, pray let me nntJlZ, f !? '^-T ¥ '° ^™^ <l««»al people tmtil my father died and my mother took it over. 1 m sorry I can t get sentimental about it, as if to ZTriTT^^'i ^^' ^'- Spoo^^r- I want of it" P ' "^'^"^ ^^^ the sight only assmne Sit he h«f ^"^ ^°«- ' ^ to the destruction of pirkF™/""!!""'?' has got bitten by the fev™^^ ^'' ^" ^»« sugaX'^lfe ''whri "™«^ '^ down." employed more tod^™"' t^ ^Trch^'V^.' X shouldn t wondpr if =».<. T °peecn. And gir^ aren't onXlUlttrX'rnkS: "^" pretJ^ tS.e^yXTatti£^i ^^^^^^ of a mistaken," rep'lied Mr ISr' "^' "" ^''^ """^ be a blow to^e dd mt CT""'° ^o"''* of blows; and, afte? Si one ^Sd IT n ''•'^''* one's hfe to suit the sentikiente rf old f^lv^Sff give them every facilitv. Also tea, or beer, or whisky, or whatever they want. About what's going to happen to you and Mrs. Peddle, don't worry a bit. I'll look after that. You've been joUy good fnends of mine all my life, and I'll see that everything's as right as rain. He turned, before the amazed old butler could reply, and marched away. Peddle gaped at his retreating figure. If those were the ways which Mr. Marmaduke had learned in the Army, the lower sank the Army in Peddle's estimation. To sell Denby Hall over his head! Why. the place and aU about it was his! So deeply are squatters' rights implanted in the human instinct. Doggie marched along the famiUar high road strangely exhilarated. What was to be his future he neither knew nor cared. At any rate, it would not he m Durdlebury. He had cut out Durdlebury for ever from his scheme of existence. If he got through the war, he and Peggy would go out somewhere into the great world where there was mans work to do. Parliament! Peggy had suggested it as a sort of country-gentleman's hobby that would keep him amused during the autumn and summer London seasons — so might prospective bride have talked to prospective husband fifty years ago. ParUamentI God help him and God help Peggy if ever he got into ParUament. He would speak the most unpopular truths about the race of poUticians if ever he got into Parliament. Peggy would wish that neither of them had ever been bom. He held the trenches' views on politicians. No fear. No muddy politics as an elegant amusement for him. He laughed as b« had laughed in the dming room at Denby «freat world would be Sfore Ll^"^ T ^he me some sort of an idea of ^h,"- ^"* ^i^e do." she would w"th .IrfL^"' y<?" Propose to And there Doggirwas'^S ^u^^t^l '^"dghost of a pTo^ZZT \Uh ?!. ^""^ ""' the the war. uSiT^BrUi^ ^ ■l'^'^ J'^ ^^^ « would bring it ti a peStPnH "•"'^ genius that would be unimarinwl n«r!>w ".''•• "l ^^ich there that it would be conSeot^ L P^ conviction welfare of those men Xm ^"fr, '''^^ ^^e know and love- Se mpn ^ I ''^' ^^^'^ to little pleasurr* writing? ^''^Z?. "'''^^ was task, tLgCfesoTth^Lr,},''^"?"'"^'* '«^rious art a sealld^k- 0,1 Z t interpreted through foul metapSoi^the men W r '^^"^ «P««* wL whose cnide iM^^LHr' ^.^™-d«™-semi-edacated, can be of divme glory in man. And when they came home and the high eoda sounded the false trumpet of peace? ,. %'« .0!>'<1 be men^s work in England for aU the Doggies m England to do. Again, L' P^gy could understand this, all would be weU. If she missed the point altogether, and tauntiMly advi^ Wm to go and joi? his friend Mr. Ramsay Macdonald at onw-then-he Kretad L'ttt -"' °' "^ '''"'' ^^ ^'^ "Everything will be in the soup," said he. lliese reflections brought him to the Deanery. ^n^ ^ ^'Hu^«l™ ¥ K"«K«' smol^ng a pipe, and entered the house by the French window of the dining room. Where should he find Peir<rv? ^1 Ak ^"^^ ^^ ^ ^^^ b« immediate i£terv^ew. Obviously the drawing room was the first place of search He opened the drawing room door, Eighsh Deanery, and strode in. RoiinH 1hi?Tif ""? ?• I"^^^' ^ protected from sound, that the pair had no time to start apart before he was there, with his amazed eyes^ upon them. Peggy s hands were on Oliver's shoulders, tears were streanung down he/ face, as her w^ . i'if"'^ back from him, and Oliver's ann was around her. Her back was to the door. T' k"' ^"^^ Peggy twisted a rag of a handkerchief and wavered " InH % ^'f^ i?^-, You^^e been wonderful." And although it didn't look like it, I was trvinff to play the game when you came in. I Teally waf And so was he." She rose and threw X hrdl kerchief away from her. "I'm not going to S out of the engagement by the side door you've S rvouTe ^W • '"' r.^^P'^ '^-S. It Itaid u you Ijke. If the savaX^ .tl a 'T '" "^ modern with another feUow^he^.pfv "^t ^"^ "^ tomahawks until h^' has^™H^ with clubs and ing known MF tn ^f 1? "^°le msult. Hav- a couple of years of her life over him that hp had never loved her? Instead of repNiiK T, he? question, he walked about the room WworrS 'ITien Doggie suddenly laughed out loud and took her by the shoulders in I grasp rouS thS she had ever dreamed to lie m the strpnXtjTT^ nature of Mannaduke Trevor, ^d kisS Te? the heartiest honestest kiss she had ever had from man, and rushed out of the room for pence by the West door of the cathedral, tongues could scarcely have wagged faster. But Doggie worried his head about gossip not one jot. He w£is in joyous mood, and ordered a Gargantuan feast for Chipmunk and bottles of the strongest old Burgundy, such as he thought would get a grip on Chipmunk's whiskyfied throat; and under the genial influence of food and drink, Chipmunk told nim tales of far lands and strange adventures; and when they emerged much later into the quiet streets, it was the great good fortune of Chipmimk's Ufe that there was not the ghost of an Assistant Provost Marshal in Durdlebury. "Doggie, old man," said OUver afterwards, "my wonder and reverence for you increases hour by hour. You are the only man in the whole wide world who has ever made Chipmvmk drunk." a splendid chap. El cetera, et cetera, el cetera." He had lost a dreaded bride; but he had found a dear and devoted friend. Nay, more: he had found two devoted friends. When he drew up his account with humanity, he found himself passing rich in love. His furlough expired, he reported at his depot and was put on light duty. He went about it the cheeriest soul aBve, and laughed at the memory of his former miseries as a recuit. This camp life in England, after the mud and blood of France He was not sorry that the exigences of service prevented him from being present at the wedding of Oliver and Pecgy. For it was the most sudden of phenomena, like the fight of two rams, as Shakespeare hath it. In war-time people marry in haste; and often, dear God, they have not the leisure to repent. Since the beginning of the war there are many, many women twice widowed. . . . But thai is by the way. Doggie was grateful to an unpateful military system. If he had attended — m the capacity of best man, so please you — so violent and unreasoning had Oliver's affection become, Durdlebury would have gaped and whispered behind its hand and made thmgs uncomfortable for everybody. Doggie from the security of his regiment wished them joy by letter and telegram, and sent them the wedding presents aforesaid. Then, for a season, there were three happy people, at least, in this war-wildemess of suffering. The newljr wedded pair went off fc- a honeymoon whose promise of indefinite length is eventually cut short by an unromantic War , iTice. Oliver re- was folTman"Kenf n'" ^-i?^-^' -ho hand in ben^ dSisS of ,?.'^- "" ^^^^ « a great mercy™ ™he'£,t«LT™^°-. ^^^'^ man she lovel'ii of- weU ' ''"' Mr^^^ ?« The Dean gasped. His wife's smile playinif iromcaUy among her wrinkles was rather beautifd. Peggy 8 word, Edward, not mine. The modem vocabulary. It means — " good deal to find out. For pog«ne had told Peggy nothing more about the gu'l m France. Jeanne was his own precious secret. That it was shared by Phineas and Mo didn t matter. To disc-jss her with Peggy, besides being urelevant, m the circumstances, w<(t quite another affair. Indeed, when he had avowed the gu'l in France, it was not so much a confession as a gaUant desire to help Peggy out of her predicament. For, after all, what was Jeanne but a beloved war-wraith that had passed through his life and disappeared? Oewa, IS not the least extraordmary phenomenon Now that Doggie had gamed his freedom, Jeanne ceased to be a wraith. She became once again a wonderful thmg of flesh and blood towards whom all his young, fresh instinct yearned tremendously. One day It struck his ingenuous mind that, if Jeanne were willing, there could be no possible reason why he should not marry her. Who was to say him nay? Convention? He had put all the convenUons of his life under the auctioneer's hammer. AU he had to do wm ^Z.^ V^'' °^ beauty, his wooing in eSf^L°"--^T°«a°dl>eg/„ in the world for aTellLZ^ ^'™P''* adventSre man -if only tIaT v„^ ^'^ ^attached young private solSofacti^ve'^r '«'' ''°* ^^ « 1^ ht'^eftSl j:-H,>^« PJ-^ his hand over to Frelus again?^' NS^Ll'LTnd or,^' ^' «'' any rate, which might hTvl u ^® "• at was nothing for it hn7 a ^^". '°<- There by letter, lo he Lote tT'^P^T ?^ '"t^acy loyalty to Peg^Xd mJlTT ^^ '""«' ^bicfe right had he to expect T^pnn/t^^" T"'' ^^at wonder of hereelfXr a W i° ^i^" ^ «" be Being what he waf -^ ^e n^' •n"^"^'«^ After a few yards she glanced over her shoulder to see whether he was following. But Doeme remained by the raiUngs and presenUy went off to a picture palace by himself and thought wistfully And Jeanne? WeU, Jeanne was no longer at t'relus; tor there came a morning when Aunt Morm was found dead in her bed. The old doctor came and spread out his thin hands and said "Eh bien and "Que voulez-vom?" and "It w8« bound to happen soonei or later," and murmured learned and vestibuJe in heaVv uVvt.^^ ""^ entrance possible Aunt Morb^was laid t^^ ? ?^'J «« «« cemetery adjoining th^ churl '^'r"" ^« "'^e back to'the Lu^vS tS?: tV** ^^^^ e°t world. And becaul^ therTtH ^"^ '° ]•« ^'^o theplacethebaietedsoinTpr^ ^.^° « ^'eath in yarf very quietly «''^«'swent about the court- Since Phineas and Mo nnH n«„ • . had gone away, she had dewfed w^fh' ' "'^^°* sionate zeal, all the t;m« pti irij'"" " "^^ passick woman U, the coStf of ?hp^ spare from the restrained by the SS^hT 1„ ™^°- No longer Aunt Morin/but wiKU' The?'r;n™«^ \ — and money restorerf Z, k u "'^^ *» sp^nd dear and heroic^i£.,t' >,^th«e '»«''« unexpected treats orrich^.j! "'"i' «!,\« the™ and suborned old women ^ f ? darned for them spired with the Tov^ M^ior t« P J"'-. ^''^ ««>more habitable- 3 th^-" T ° ^^C,^^?" ° g^nary not to issue a 'ret^ t a cTtiiJ!^"'' ^^'^ ^«^ ceived all her suff^P,t;^L ^?™e » expense, re- siasm. ToiSte "SgTood 'cte'?o"^"' «°^every British sc^ld^wh^,?^ ^^ to mipress upon the fact that iT^L ■ ^P"^ understand fcr dividu^y he wasSrT?" personally and i,: the fame^f jJaZe K^t^L'^/t^ ^"«^««. sector of the From bS whicHav f'S""^^ r« currently spread the Xrt f ?! ^ ''fS'^- Con- 5»o, on the day of the funeral of Aunt Morin. the whole of the billet sent in a wreath to the house, and the whole of the billet attended the service m the htUe church, and they marched back and drew up by the front door -a guard ol honour ejrtending a httle distance down the road. The other men billeted in the village hung around, together with the remnant of the inhabitants, old men women and children; but kept quite clear of the guarded path through which Jeanne was to pass. One or two officers looked on curiously, r .k^^^u^^ "',^'' background. It was none of their busing. If the men, in their free time, chose to put themselves on parade, without arms ™ course, so much the better for the army. Then Jeanne and the old Curfi, in his timescaired shovel-hat and his rusty soutane, foUowed by lomette, turned round the corner of Jit • ne and emerged into the main street. A s. rceiit gave a word of command. The guard stool at attention. Jeanne and her companions proceeded up the street, unaware of the unusual, until thev entered between the first two files. Then for the lu^t tune the tears welled into Jeanne's eyes. She could only stretch out her hands und cry romewhat wildly to the bronzed statues on each side of her, ^Merci, mes amis, merci, merci," and flee into the The next day Maitre Pepineau, the notary summoned her to his cabinet. Maitre Pepineau was verv old His partner had gone oflF to the war. One of the necessiUes of the present situation, he would say, "is that I should go on living m spite of myself; for if I died the wTiole of thi atfmrs of Frflus would be in the soup." Now. a turtaight nack, Maitre Pepineau and four neigh- boura — the four witnesses required Lv Frenrh aw when there U only one no^yTdraw u7£, instrument puUic- had visited Aunt Mori? iS Jeanne knew that she had made a fresh wiS ' Mon enfant, said the old man. unfoldinir the document Sn a previous will your Aunt h^ left you a httle heritage out of the half of her fortune wind, she was free to dispose of by the c^e 'R having come mto possession of your own money she has revoked tfiaT^U. and feft everJtCg^ gaLT'^ "^'""« "'• ^""P"^ MorinTnMfd^ '•It is only just and right," said Jeanne. mJ^ p"iv°'"''°5. P"' of the matter." said Maltre P^pmeau. "is that Madame Morin has appointed official trustees to carry onThe «,£?! untJ Monsieur Gaspard Morin caA make L ^ arrangements. The result is that you have Z hem standi as a resident in the hou.^ I St^ this out to her Bui you know, in 8rite^"S good quahUes. she was obstinate It i«^ ''So we must separate, Toinette?" Alas, yes, MademoiseUe — unless MademoiseUe would come with me to Paimpol." leiii m love with. "MademoiseUe," said Toinette later, "do you think you wiU meet the Uttle English soldier. Monsieur Trevor, in Paris?" CI, mou fatahsm m her tone. So Jeanne waited for a dav or two until the regiment matched away, and tiien, with heavy hem set out for Paris. She wrote, indeed, to thine^' and weeks aftemards Phineas, who was in the thick ot the ^mme fightmg, wrote to Doggie telling him Pans address. And in the meantime the house of Gaspard Morin was shuttered and locked and sealedT and the bureaucratically minded old Postmaster of Fr^lus who had received no instructions from Jeanne to torward her correspondence, handed Doggie's letters and telegrams to the aged postman, a superannuated herdsman, -ho stuck them into the letter box of the deserted house, and went away conscious ot duty perfectly accomplished. „3^°'.^-lf ' ?°P^' £ ^^^ f"'" active service, went out with a draft to France, and joined Phinea^ and Mo, ahnost the only survivors of the cheery femibar crowd that he had loved, and the grimnei We re aU going to die of rheumatic fever " ^ast^EdrU"^^'"^ ^ ^ -'<^- -^o^vrSS IW.I^ hand beneath his clothing and THE fighting went on, and to Doggie the inhabitants of the outside world became ahnost A . as phantasmagorical as Phineas's providential Aunt in Galashiels. Immediate existence held him. In an historic battle, Mo Shendish fell with a machine bullet through his heart. Doggie, staggering with the rest of the company to the attack over the muddy, sheU-tom ground, saw him go down, a few yards away. It was not tiU later that he knew be bad gc«ie West with many other great souls. w°M'^.^^ Phineas mourned for him as a brother. Without him, France was a muddier and a bloodier plMe, and ^e outside world more unreal than ever. Iben to Doggie came a heart-broken letter from the Dean. Oliver had gone the same road as Mo. Peggy was frantic with grief. Vividly Doggie saw the peaceful deanery, on which all the calaimty .. «,r^ 7^, ^^^ crashed with sudden violence. Why I should thank God we parted as friends, don t qmte know," said Doggie, 'but I do " I suppose laddie," said l>hineas, "it's good to leel that smihng eyes and hearty hands wfll greet us when we too pass over the Border. My God, man, he added reflectively, after a pause, "have "I supMse It does to us while we're here," said Doggie. We ve seen such a lot of it. But to those who haven t — my poor Peggy -it's the end ol her umverse. reserve, and so continued Zing the tu^tl "" winter months. And the morP f h! '1 ^^'^?^ crept by. and the mo^ remote ^erZdL^^' g'^Xf,. Doggie hungeredTofthrSft ofTer' was declared, when they wodd have Ze to S to Rwir '°«ttf^-r^«Pt«i° WUloughb? had S to Rhghty with a leg so mauled that never wS he command again a companv in the fillS « geant BaUinghall, who haltelght Doggfe'to^" on tiie invention of a boxing dove which would enahle hun to carry on his pugilistic career. "So m future times " said he, "if any of yo.u- friend^ among the nobihty and gentry want lessons in the ? n f. ^,V ^°^ ^"""S®* y°"r old friend Ballinghall. Whereat — mcidentally — Doggie wondered. INever, for a fracUon of a second, during their common mihtary associaUon, had Ballinghall given Jmn to understand that he regarded hun otherwise than as a mere Tommv, without any pretensions to gentihty. There had been times when Ballinghall had cursed him — perhaps justifiably and perhaps lovingly — as though he had been the scum of the earth. Doggie would no more have dared address him in terms of famiUarity than he would have dared slap the Brigadier-General on the back. And now the honest warrior -ouffht Doggies patronage. Of the original crowd in hJigland \fho had transformed Doggie's military existence by makmg him penny-whistler to the Company, only Phmeas and himself were left rhere were ou.ers, of coiuse, good and gallant leUows, with whom he became bound in the rough mtunacy of the Army; but the first friends, those under whose protecting kmdUness his manhood iMd developed, were the dearest. And their ghosts remamed dear. was more fighting. One day, after a successful raid. Doggie tumbled back with the rest of the men mto the trench and lookmg about, missed Phineas. "I've got it dean S^p'n^™ rj^""- ^"^ ""^ 1»« °«t ^^ last m^ Hrpni nf '^^ Company, as he had joined it, h,^ dreds of years ago \n England? It was only thin that he reahsed fully the merits of the wastrel Phmeas McPhail Not once or twice, but TS sand tmies had the man's vigUant affection, veiled N^'".nT'^.^'^^'"' ^^^ ^ from delp^ Not once, but a thousand thnes had the gaunt toeless Scotchman saved him from physicllTx: haustion. At every turn of his career since his helpful, devoted. There he had been alwavs mdy and willing to be curbed. To cShi^Zd been l^e great comfort of Doggie's Ufe. Whom could he curee now? Not a ISul-no one ^ any rate, agamst whom he could launch an ankth- IZ Z^.J^'^i^^e^^ ^ '• Than «««« vainly and superficially, far better not to curse at alL He missed Phmeas beyond all his conception of ^e blankness of bereavement. Like himsSf, PhL^ had found salvation in the army. Doggie reah^ how he had striven in his own qieer wayto rX^ the ^HLUainy of his tutorship. No ^ImL^S ^"L^? T^^ 8«°le, more unselfish. ^ " Time was when I could not have addressed you wilhout incurring your not unjustifiable disapproval. aut 1 take the liberty of doing so now, trusting to your generous acquiescence in the proposition thai the war has purged many offences. If this has not happened, to some extent, in my case, I do not see now it has been possible for me to have regained and retained the trust and friendship of so sensitive and honourable a gentleman as Mr. Marmaduke Trevor. tying severely wounded, it is not with an intention to TH L"^•^T'i^•'j^ "^yf'V personalty -although I It not deny Oiat the sight of a kind and familiar face would not be a boon to a lonely and friendless man — but with a deep desire to advance Mr. Trevor's happiness. Lest you may imagine I am committing an unpardonable impertinence, and thereby totalh misunderstand me, I may say that this happiness can only be achieved by the aid of powerful friends both m London and Paris. r j j <^ — tbnking ... Poor old Doggie But how m the name of all that was meant by the word Lflve she could ever have contemplated — as she had contemplated, with an obstinate, virgmal loyalty — marriage with Doggie, she could not understand. She undressed, brought the straight-backed chair close to the fire, and, in her daL y nightgown, part ot her trousseau, sat elbow on knee, face in thin tJutching hands, slippered feet on fender, thinking' thi^ung once 8,7nin. Thinking now of the gatS of Paradise th-^t li^d opened to her for a few brief weeks. Of the terrifying meaningiessness of bfe, now that her God of Very God, in human form had been swept, on an instant, off the earth into the Unknown. Yet was life meaningless after all? There must be some significance, some inner truth veiled in mystery, behind even the casually accepted and never probed religion to which she had been bom and m which she had found poor refuge. For, like manv of her thoughtless, unquestioning class, she had looked at Christ through stained-glass windows, and now the windows were darken^. . . . For the first time in her life her soul groped intensely towards eternal verities. The fire burned low and she shivered. She became again the bit of human flotsam cruelly buffeted by the waves She dragged from a reluctant Phineas the historof his wound, and obtained confimiaUon of hib statement from a nurse who happened to pass up the ga<igway of the pleasant ward and Ungered by the tedside. McPhail was doing splendidly (» course, a man with a hole tlu-ough his body must be expected to go back to the regime of babyhood. So long as he behaved himself like a weU-conducled baby all would be weU. Peggy drew the nu«e a few yards away. o ^'""V^^J^^T^ •."' ^^ ''^"^t friend out there, a bov whom he oves dearly and has been through the whole thmg with him m t!.e same company -it's odd, but he was Ins private tutor years ago — both f ^nfJlf "Vi"" '^'Vr ~ '■" ^"'='' ^'™ »«^« J"«t to talk ^ w^f H ^^«P ^^^ somewhat incoherent — , WeU — I ve lust heard that the boy has been seriously wounded. Shall I teU him?" r,i^ f"^'- "I™, grateful to you, Mrs. Manmnstree, for concermng yourself about my entu-ely unimportant carcass. Now, as Virgil savs paullo majora canemus.'" " ^ ' '•You have me there, Mr. McPhail," said Pe^jry • .uV^fj""^ f somewhat greater things. That 18 the bald translation. Let us talk ofBoirtrie if so be It 18 agreeable to you." Dog^e. I m bMinning to have my doubto. I also uMgined that I was very careful of my psraonal betongings; but facte have convicted me of CTuninal He continued the story of Jeanne; how she had learned through him of Doggie's wealth and posiUpn and early upbrinmng; of the memor^le dinner party with poor Mo; of Doggie's sensitive mterpretation o, fier French bourgeoise attitude; and finaUy of the loss of the letter containing her address m Paris. After he^d finished, Pewry sat for a long while tiunking. -This romance in Doggie's life had moved her «e she thought she could never be moved since the death of Ohver. Her thoughte winged themselves back to an afternoon, remote ahnost as her socked Mid sashed childhood, when Doggie, immacuktely attu-ed m grey and pearl hSnonies. had declared, with his httle efiFemmate drawl, that tennis made one so terribly hot. The scene in the Deanery garden flashed before her. It was succeeded by a scene in the Deanery drawing room, when to herself mdignant he had pleaded Ms delicacy of constitution. And the same Doggie, besides bravmg death a thousand times in the ordinarv execution of his soldier's duties, had performed this queer deed of heroism for a girl, ^en his return to Durdlebmy — , ,','^'™ afraid," she said suddenly, "I was dreadfully unkmd to hm when he came home the last time. 1 didn t understand. Did he tell you?" "Maybe." said Phineas. "It's an ill „», i, . blows nobody jfood aiTl'™^ "'.^^T ^t this one. ButCwe^telkwT complaining of henaion of Dogjie" ^^ "^ ^""^ miscompre- bk^JrtW 7^8 to see a Uttle bit -a litUe tot further — I can't express myself— " ^k-®T ^' "• Manningtree," said Phineas n..-7lfc„?f\°^^°i ¥^- Mannmgtree,that I commit myself to a definite statement. But. to mv o^ knowledge, these two are breakiig thS^ tef^' each other. Couldn't youfiS her before the poor laddie is killed?" Hew;asdive. Only severely wounded. He would be commg home soon, carried, according to convoy TlnH '^"i?*'^ ^J^P'^ dmnping-«-Sund^Te K^ jTf'T- , V'^y « coid bring this «^^,f? ^ It' ^^^ ye™^' to make ilparation for the past, to act accordbg to the new knowledge that love and sorrow had broughlhw THE Dean of an English cathedral is a personage. He has power. He can stand with folded arms at its door and forbid entrance to anyone, save perhaps the King in person. He can tell not only the Bishop of the Diocese, but the very Archbishop of the Province, to run away and play. Having power, and using it benignly and graciously, he can exert its subtler form known as miluence. In the course of his distinguished career he is bound to make many queer friends in high places. they ask for. When Peggy returned to Durdlebury and i Doggie's case before her father, and with unust fwvour roused him from his first stupefaction at the idea of her mad project, he said mildly: "Let me understand clearly what you want to do. You war.t to go to Paris by yourself, discover a girl called Jeanne Boissiere, concerning whose address you know nothing but two words — Port Royal — of course there is a Boulevard Port Royal somewhere south of the Luxembourg Gardens — and re-establish communication between her and ■ gSS/' ^^-^'-S^'^y iplay Fairy ;; If you like to put it that way," said Peggy • ?^ ??" ^te certain you would be actimr ''•ffly? From Mannaduke's point of view — " Dont call him Marmaduke— " She bent forWMd and touched his knee caressingly — "Mannaduke could never have risked his life for a woman It was Dojtgie who did it. She thinks of him as JJoggie. Everyone thinks of him now and loves 5™, as Do-gie. It was OUver's name for him. don t you aeeP And he has stuck it out, and made It a sort of title of honour and affection — and it was as Doggie that Oliver learned to love him, and m his last letter to OUver he signed himself ' Your aevoted Doggie.'" Whether he wrote to Field Marshals and Ambassadors or to lesser luminaries Peeiry did not kflow The Dean observed an oli-wofS^punctmo about such matters. At the first reply or two to his letters he frowned; at the secon/ or two h^ anJed m the way any elderly gentleman may 151 when he finds hunself recognised by high-andmi^^htmesses as a person of importance. So it came to pass that while Doeeie with a shattered shoulder and a touched iTllJ wat being transported fix>m a base hospital iTprance to a h(»pital m England, Peggy, Uied with dl ^fi°LP^P'^,«°' recommendations, and a very fixed, personal sanctified idea, was crossing tne Lbannel on her way to Paris and Jeanne. ,r-.^^'-^f ^' '* '^^.°° ^'J* «o«se chase, but a very sum)le matter. An urbane, elderly person at the tfritish. Embassy performed cemhTiT phonic gymnastics. At the end: Merci, merci. Adieu!" morrow mormng. ==J^L°?'^^^..''^f^' °°^ notes- and confidently M J^ ^% ^/ ^^ ry^^ "^"^ the addreL 7f MademoiseUe Jeanne Boissiere within twelve hours. telegraphic telephonic, and municipal systems of France work m perfect order- to Ly noE of that of the police. Fr^lus. I think, is the S of the place she started from?" " At seven o'clock in the evening, after her lonelv dmner in the great hotel, the^hij offidd 3 a«a™; She met him in the loun\|e. Madame," said he. "I have the nleasurp t/. ,•„ forai you that MademoiseUe Jeanne bSI?^ iSe of Frelus, is hving in Paris at 743'^ BoSd Port Royal, and spends aU her days at the succ^e 5 the French fted Cross in the Rue VaugirarcT^ ''I am infinitely grateful to you," said Peggy, tocbl "^ « ^ <fe q»oi, Madame. I perfom the tasks assigned to me. and am only toThaZr i^ this case, to have been successful " ^^^' \anSTL^^'^-^'^"A^^^'^^' ^^'^ desperately « T, ,1, l^' ^^ pathetically eager to talk to a human being, even in her risty VIvey ^ool French, "haven't you wondered why I^e W so aiuious to find this young lady?" laugH at the things which happen durine the war we should be so bewildered ^^at w^shSulda't be ahle to carry on our work. Madame." saM he handing her his card, "if you should haveZthe; pi^^lT!^ ^'' "^^ °°« ^""derful fortnigK M^ ^^H** ever known, they had chosen tWs dignified and not mcxpensivc hostehy. To her girhsh mmd. it had breathed the last w?rd of%lS tHrough the wonders of the enchanted city. Her brief dreams had ecHpsed her girUsh memories. XNow the dreams had become blurred. She strove to bnnp them back till her soul ached, tiU she broke dowB mto miserable weeping. She was alone in a strange, unedifymg town; in a strange, vast, commonplace hotel. The cold, moonUt Place de la VendSme, with its memorable column, just opposite her bedroom window, meant nothing to bar She had the desolating sense that nothing in the world would ever matter to her again — nothing M far as she, Peggy Manningtree, was concerned! tier life was over. Altruism alone gave sanction to continued existence. Hence her present adventure. Pans might have been Burslem for all the mterest it affoided. a matter of conscience. But she tmrnA tw Vu e K°^ •^'^«"^ hospital" wS: teigS wUh Enghsh girb; and she could not ewn sw^k^ ^age So guided by the Paril frieff wS whom she lodged, she made her way to Se Rue Vaugirard. where, in the packing-room, she fomS hard^and unemoUonal employment YrtXw^k had to be done: and it wa^ done for FrSce wwS fcetw^lrr^' '° ^'' ^^ England^^ = b^^eZAlJ^' "''^ "rH««' be-medaUed i^Mo^ ^th III' «PP«"«* to her in the packing room, with the announcement that a ^une never met one in her life. It tolk a seS or Two JJoggie. Then came convict on. In blue overflH anJcap, she foDowed the concierge to the a^t^.^^ her heart beatmg. At the 4ht of X vZS; "a^? '?"^ of Monsieur Trevor—" Ah, Madame -" Jeanne pointed to the mournmg — you do not come to tefi me he is dead? " Pe-ysnuled. "No. I hope not." AH I Jeanne sighed m relief, "I thought—" She led the way to the bench. They sat down together, and for a feminine second or two took stock of each other. Jeanne's first rebellious instinct said "I was right." In her furs and perfect millinery and perfect shoes and perfect black silk stockings that appeared below the short skirt, Peggy, blue-eyed, fine-featured, the fine product of many generations of scholarly English gentlefolk, seemed to incarnate her vague conjectures of the sodal atmosphere in which Doggie had his being. Her peasant blood impelled her to suspicion, to a half-grudging admiration, to self-protective jealousy. The Englishwoman's ease of manner, in spite of her helter-skelter French, oppressed her tnth an angry sense of inferiority. She was also conscious of the blue overall and close-fitting cap. Yet the Englishwoman's smile was kind and she had lost her husband. . . . And Peggy, looking at this girl with the dark, tragic eyes and re&ied, pale face and graceful gestures, in the funny instinctive British way tned to place her socialW. Was she a ladyf It mi "3 such a difference. This was the girl for whom jL>oggie had performed his deed of knight-errantry; die girl whom she proposed to take back to Doggie. For the moment, discounting the uniform which might have hidden a midinette or a duchess, she had nothing but the face and the gesturen and the beautifully modulated voice to ^j"P?°'j"^ between the accent of the midinette and Uie duchess — both being equaUy channinir to qk' ?°!^ ear -Peggy could not discrSte. bhe had, however, beautiful, capable hands and took care of her finjrer-nails. Jeanne broke the tiny spell of embarrassed silence I am at your disposal, Madame." Peggy plunged at once into facts. It majr seem strange, my coming to you; but ine tact is that my cousin, Monsieur Trevor is severely wounded ..." Her French failed her — to carry off a very delicate situation one must have command of liminiaKe -she could only blurt out -"///an/ comprendie. Mademoiselle. Uafailbeaucouppourvous." She met Jeanne's dark eyes. Jeanne said: "Oui, Madame, tous avez raison. II a beaucouD fait pour moi." ^ „ Peggy flushed at the unconscious correction — beaucoup fait," for "fait beaucoup." "He has done not only mu<±, but everything for me, Madame," Jeanne continued. "And you who have come from England expressly to tell me that he is wounded, what do you wish me to do? " S^nJ^ f ^" ^ x?**" . ^«;«^ "t the lack of response from Fr6Iu8, and, after all. Fr^lus had a properly constituted post office in working oitler! ^th^rt'-f^ ^'^^^^ ^ forwarTlettere. pU But '"°™ ^™^ prepared to reproach the fom thai ™gi, have dated iom 1870 vheiE p.d»go m and out. group. uM^ of the bSZ of lie organisatmi, here and there a bl«°^Sl jouag heatenm and a blue^verdlS pkS" Jeanne said; "Madame, I am profoundly moved by what you have told me. If I show Uttle emotion. It 18 because I have suffered greatly fiom the war. One lewm self-restraint, Madame, or one goes mad. But as you have spoken to me ia your noble Enghsh frankness — I have only to confess that 1 love Doggie with all my heart, with all my soul — " with her two clenched hands she smote her breast — and Peggy noted it was the first gesture that she had made. I feel the infinite need, Madame — you will understand me, — to care for him, to protectnim — Jeaime I^t forward and grasped the protestmit r^ru^^^.^''^: «"< fiere was a wonderfid light behmd her eyes and a curious vibration in her voice. "It is only les petits h&ros tout faiU — the Uttle ready-made heroes — ready-made by the bon Dieu — who have no need of a woman's protection. But It IS a different thing with the great heroes who have made themselves without the aid of a bon JJieu, from htUe dogs of no account (des petit* chiens denen du tou/) to what Dog-gie is at the moment. Ihe woman then takes her place. She fixes thmss for ever. She alone can understand." Peggy gasped as at a new Revelation. The terms m which this French girl expressed herself were far beyond the bounds of her philosophy. Ihe varyme aspects in which Doggie had presentwl hunself to her m the past few months, had been bewilderm^. Now she saw him, in a fresh light, though as m a glass darkly, as reflected by Jeanne, faitT^J^ ?■ ^^t ^ '^™^; fro'" ^ant of laitL m his destiny. Madame. Once he told me he had come to France to fight for his soul It i^ necessary that he should^be vicSrioT It & nwiessary that the woman who loves him should maAC him victorious. ^^ ououia she'^sSd^?, il!!'^'r^?f«?«' MademoiseUe," Me said sudply. 'I couldn't have done that" She paused. 'VeU?" she resumed. "Will^u nowcomewithmetoondon?" ^ nf n.Tr''^"j They told him that the Dean of Durdlebuo had caUed; had brought flowers Md fhut and had left a card "From your W Peggy, andmyself." But Uniay he felt SiSy strong, in spite of the unrelenting pain, and the nurse had said: "I shouldn't wonder if you had Hflii^iS'!i.^^ afternoon." Peggy, of course. ±le followed the hands of his wrist watch until thev marked ttie visiting hour. And sure enough, a mmute afterwards, amid the stream of men and women — chiefly women — of all grades and kinds, he caught aght of Peggy's face smiling beneath her widow s hat. aie unpumed the violets and thrust them towards " \|f\|°™ »o™e. I've brought 'em for you." My God!" said Doggie, burymg his nose in the huge bimch. I never knew violets could smeU take this. He laid them down with a sigh. " How's everybody?" ^ "Oh, that's an right," she said bravely. "I know you care, dear Doggie. That's enomrh. I ve just eot to stick it like the lest." She withdrew her band after a litUe squeeze, "Bless you Don t womr about me. I'm contemptibly healthy. - "Nr^?'^^^™^''^' Uncle Edward?" Dean'^^tSe'emp^^^^^ ^^ ""'^ «— d the 1'™°^ 1?'^ Pl'inea''? Has he come throueh? thinking of Phmeas. Of his last wonfs m he dS rS^Son of^h'^^^^.P^-^" «=hemes for reorganisation of the social system, Phineas haH ms place.. No furUier need for de^ oW pLSs He looked round contentedly, and saw Pemrv and a companion coming down the ward toeetifiw And It was not PhineaT'lt was a prrrblaX Aitoir c« wwtinw. but not of w. Love «id myrto, «rf love wun-llHae «e the thwui, the wm god t«wlX7w J ^J^-.TT'""' » tti,. hi. bert .to,nn«^^ mYv^ V\|M.bond." nough it h« w„ for it, b«kgromd. "iST^ PUjnet" » . rtoo- of home; it h« if ^t^gTHiiet LlS vUI^e wh«, d^U the mother, „d f.th«^the ^^ll^ he«t. o, ,w who a« out "„„ewhe«." W i. ZTI^ g~t devobon, «id quiet courage «,d myteor. And^ T S^of'f jT '"' '^ ■»« 1^ "o-ntO' thrill, you with U» wltl '!fCT"," " "" "°°»""'« """biMtio. of the mod<fii «wl the mid W«Un th.t f«a.„,.. th, ™d.r of -Th. B«i PUort/ a ^XiS^ ■fab. ., Mr. Locke'., „ EngUod ,„bbe,-H™d u>d beU-be™, ooTt^SSi ■nebn. inlereetin., even heroic or lo«bJe, !!«,« out oiZZT^,^^toil .„ch „ the. of hU 'Bebved V;^d.° Id Z^ ."TSTjSf d-^ h.m „ he unfold, thi. .u.r, through the p.„'„d pJTXS^S^ Mo.«lyth..ta»>.l helpl,» perdytio though hi. feeding cWeter U wl w« co«.p«,d«at who. betw«n hi. UA.. enliven, uid »me! lime, comphcu, l« d«™ung home life ol „ rfd CmbX In^. Th.m«.Ulp^l<^<rf.u^d«m..e.whoCS •^•J^enee. tandacape architecture, stained gla«, pottaS «»dthenumeTOu,oU»hMrficrafta.etc. The Inte^lS faSSEfeT""^ a. pUoe a. the leuimg art^SS in the Ei^hd, language ever amce it» first iMuek Mardi^Sl!	72,574	common-pile/pre_1929_books_filtered	cihm_74891	public_library	public_library_1929_dolma-0008.json.gz:3438	https://archive.org/download/cihm_74891/cihm_74891_djvu.txt
rIcYoLJF4EvDXWvN	Technical training handbook of the Browning automatic rifle model of 1918 (air cooled) / prepared at The Infantry School of Arms, Fort Sill, Oklahoma.	WASHINGTON, September 7, 1918. The following confidential pamphlet, entitled "Technical Training Handbook of the Browning Automatic Rifle, Model of 1918" (technical training series, prepared at the Infantry School of Arms, Fort Sill, Oklahoma), is published for the information and guidance of all concerned. INTRODUCTION The purpose of this Handbook is to give methods of instruction to be used in teaching mechanism of the Browning automatic rifle, model of 1918, and to give an elementary drill of the rifle team and squad in so far as pertains to the handling and operation of the gun in firing. The method of instruction is that used in the automatic arms section of the Infantry School of Arms, Fort Sill, Oklahoma, and the drill is an adaptation to the Browning of the drill for the Chauchat rifle, as prescribed in the "Manual of the Automatic Rifle," War Department, April, 1918. It is contemplated that this book shall be used in conjunction with "Ordnance Pamphlet No. 1934," therefore, the construction, mechanism and care of the weapon is not dealt with in full herein. The information on these subjects pertains to methods of instruction, with some additional notes not contained in "Ordnance Pamphlet No. 1934." 1. For purposes of instruction the class will be divided into groups of three to four men (hereinafter referred to as teams). Each team will be assigned to a particular rifle and will work on that rifle throughout the remainder of the course. An assistant instructor (a sergeant or corporal hereinafter referred to as sergeant-instructor), will be assigned to not more than two of these teams and will supervise the same men throughout so as to maintain uniformity of instruction. There will be at least two commissioned instructors for each sixty men undergoing instruction. The purpose of such division is to fix the number of men assigned to one rifle so as to obtain maximum efficiency of instruction. More than four men working on one rifle and less than three will not give the best results. A sergeant-instructor cannot efficiently give detailed supervision to more than two teams, nor a commissioned instructor to more than fifty or sixty men. These remarks refer to the thorough instruction of a class in mechanism. 2. In the company the organization will be as follows: The automatic riflemen of the company will be combined in one class under two commissioned instructors. Each sergeant will supervise his own section (as asistant instructor) and each corporal will act as sergeant-instructor for his own squad. had a thorough course of instruction prior to their men. 3. A classroom will be provided with a blackboard, seats for entire class and one rifle table per team, sufficiently large to permit entire team to group around it while working on the rifle. DETAILED METHOD OF INSTRUCTION. 5. No discussion of functioning should be permitted prior to the completion of stripping and assembling. Nomenclature will be taught during the instruction in stripping and assembling and reviewed throughout remainder of course. Explanation-demonstration. — The instructor will make a detailed explanation of the subject to be taught, illustrating or demonstrating his explanation as he goes along. This explanation-demonstration will be made to the class as a whole instead of being made by team or squad. This insures uniform instruction for the entire class in the beginning of each subject. instructor. Introduction will be omitted. — The other members of the team will stand by with handbooks and notebooks and check up any errors of the man reciting. The sergeant-instructor will supervise this work, correct errors, assist backward men and give detailed instruction in general. As men deem themselves qualified they will report to .their sergeant-instructor for examination. He will require a perfect recitation before reporting a man as qualified to the senior instructor. tant points. 6. Care must be taken to see that the sergeant-instructor does not hinder progress by trying to impress the men with how much he knows instead of instructing them. Whenever a sergeant-instructor demonstrates to one of his men the proper way to do a certain thing, he will always require the man actually to imitate him. There is sometimes a tendency for new sergeants to be continually demonstrating, thereby preventing their men from getting a chance at the rifle or the work in hand. This will be avoided. Once a week in camp or garrison and daily in the field. (5) The magazine will receive the same care as the rifle. Every effort will be made to prevent bending or denting the magazines, being especially careful of the lips and magazinecatch-notch. mitted. 8. The rifle is so constructed as to be taken apart and put together easily. Most parts are designed with a view to prevent wrong assembling. Where difficulty arises in stripping and assembling easily it is due to error on the part of the rifle. The practice of stripping and assembling against time serves no useful purpose and results in burring and damaging parts. Gradual skill develops as men become more familiar with the gun and lost motion is eliminated. Men should be taught in stripping to lay out parts in obvious sequence of assembling and should so thoroughly learn the gun that taking it apart and putting it together is a matter of second nature. Lubrication is necessary to the operation of the rifle. Dirt and extraneous matter will prevent it from functioning and do it damage. Instruction in care and preservation should be so thorough that cleaning and oiling become a matter of habit. Unless strict supervision is exercised, inexperienced men and sometimes experienced men, will file or otherwise alter parts which do not need it. This results in damage to the rifle and usually fails to remedy trouble. Filing and altering of parts is sometimes necessary, but should never be done except by an expert, under direction of an officer competent to supervise the work. The use of rifles for instruction in mechanism is hard on them. This fact should be borne in mind and, in the company, after the completion of the first course in mechanism, only a limited number of rifles should be so used. GENERAL REMARKS. 9. Mechanism will be taught in the order given in lessons below. It may be necessary to devote several periods to a particular lesson. This will depend on the degree of intelligence of the class and the length of the period allotted. A ten-minute intermission at the end of each hour should be given if periods are longer than two hours. Each lesson will be mastered by the majority of the class prior to proceeding to the next. When subject in hand allows, the preceding lesson should be reviewed with the current one. For instance, nomenclature will be reviewed indefinitely by requiring every man to properly name each part he uses or mentions. 10. It is contemplated that "Ordnance Pamphlet No. 1934" (handbook of the Browning machine rifle, model of 1918) be used in conjuction with this course. The notes following various lessons are intended to give the instructor supplemental information. He will get additional data from independent research. His instruction, however, must not be at variance with "Ordnance Pamphlet No. 1934" and this handbook. NOMENCLATURE, STRIPPING AND ASSEMBLING. 12. Introduction. — The instructor will give a brief talk, introducing the rifle, wherein he will cover its type, caliber, characteristics and name such other points of general interest as he deems advisable. each part as he removes it. He will call attention to all cams, lugs, slots, profiles and springs, but does not at this time describe their function (bearing in mind the prohibition against discussing the functioning of the rifle prior to the completion of nomenclature, stripping and assembling). The instructor will assemble the piece acording to the same procedure. 14. After this explanation-demonstration, the teams being assembled at their rifles, the instructor will describe, step by step, how to strip and assemble the rifle, naming and describing parts as before. He will require one man at each rifle to imitate him as he finishes describing each step, the remaining members of the team observing. Every man in the class will repeat names as called out by instructor. The instructor will not allow any man to get ahead of his explanation in this stripping and assembling. Assistants will keep backward men up with the explanation (instructor must take care not to proceed too rapidly). 15. Imitation. — When this step-by-step explanation-imitation has been completed once the remaining members of the team will strip and assemble the piece, naming and describing each part as it is removed and cleaning and oiling during assembly. The other members of the team will stand by with handbooks and correct errors of nomenclature. Sergeantinstructors will supervise and assist students and will see that mistakes are corrected as they are made. They will examine men whom they believe to be qualified and report to the senior instructor those who make a perfect recitation. Ammunition. 19. It is chambered for caliber .30, U. S. ammunition, model of 1906. The magazine holds 20 rounds (there are special magazines which hold 40 rounds). Cooling System. 20. It has no special cooling system nor device, the barrel merely being exposed to the air and the hand of the firer being protected on the under side of the barrel by a large wooden forearm. Since the barrel soon becomes very hot, care must be taken to avoid touching it during firing or for five or ten minutes thereafter. NOTE. — This rifle has been fired, while marching, 148 shots per minute, semi-automatic, at the infantry school of arms and 110 shots per minute, semi-automatic, from the shoulder, prone. The rates of fire, however, which appeared to give the best results were from 80 to 100 rounds per minute, semi-automatic marching fire and 50 to 60 shots per minute, semi-automatic aimed fire. The piece must be cocked in order that the gas cylinder tube may clear the gas piston and the gas cylinder bracket, female. After the gas cylinder tube has been removed it is necessary to release the tension of the recoil spring. A natural tendency of the beginner is to snap the piece or to remove the trigger guard before letting slide forward. This will result in damage and a special point must be made of easing the slide forward immediately after removing the gas cylinder tube. 24. In stripping and assembling mechanism it will be noted that, unless tension in springs is released, the work will be more difficult, therefore, in the various steps of the operations herein described, care is taken to avoid working against tension of springs. 25. The recoil spring guide may be removed by placing right thumb on roughened surface of its head and turning it until the ends are clear of its retaining shoulders or it may be removed in a similar manner by using the index finger of the left hand and the middle finger of the right hand. This latter method is better, both in stripping and assembling, for men who have not powerful hands. the raised shoulders on the operating handle ribs. (2) Grasping slide with the left hand and pushing on the rear end with the right hand until the plunger pin just rides up on the rear end of the flat surface of the raised shoulders on the operating handle ribs. Another method is to pull the operating handle to the rear, as described above, insert the point of the recoil spring guide in the hole on the operating handle with the right hand, pressing against the hammer pin and pull the slide forward with the left hand. The recoil spring guide will push hammer pin through its hole in the receiver as the hammer pin registers with latter. Care must be taken that all forward movement of slide comes through pulling slide with the left hand, the right hand being used only to press the hammer pin out. 27. In removing the slide take care to avoid striking gas piston or rings against gas cylinder tube bracket (female) and also to see that the link is swung back so that the slide will clear it. 28. The bolt guide must be forced out enough to allow the bolt and bolt lock to be lifted out of the receiver. If the bolt guide spring is strong the rim of a cartridge may be inserted between the outside of the receiver and the exterior portion of the bolt guide, thus giving a lever with which to hold the bolt guide out. Notes oh Assembling. 31. Before inserting slide, see that link is thrown clear back so that slide will clear. Slide is inserted so that the sear notch is visible when looking into the receiver from the trigger side. ing in the receiver. 32. To insert the hammer pin, move slide forward and line up hammer pin holes in link, hammer, slide and receiver, by inserting recoil spring guide through slot in side of receiver. The hammer pin is not pushed clear through until the operating handle has been moved all the way home. 33. Be careful to put the operating handle on with the handle end forward. If it is assembled, with the reverse end forward, an expert mechanic will be required to remove it. After the operating handle has been pushed home the hammer pin is then fully seated and the slide pulled forward. 34. In assembling the trigger guard to the piece see that no pins are projecting from its sides. Seat slot, in its rear end, on flange in rear end of opening in receiver, then press back and down on forward end of trigger guard until it hinges into place. See that holes are properly registered before inserting trigger guard retaining pin. 35. Cock the piece by pushing the gas piston to the rear. Take care to register gas cylinder tube and piston on assembling same and avoid burring gas cylinder tube brackets, male and female. STRIPPING AND ASSEMBLING BLINDFOLDED. 36. Teams at gun tables. — Each man in turn, blindfolded, strips and assembles the gun. The sergeant-instructor watches him to prevent wrong assembly or forcing of parts. He may be given assistance in event he cannot proceed otherwise. If he calls for any part, by its right name, same will be handed him. The other members of the team not blindfolded will have various parts put in their hands while same are behind back and will name parts by feel. Extraneous pieces of metal may be introduced in this latter exercise. (1) Sear spring (insert handle of trigger guard retaining pin under sear spring, above connector stop, pry up, pressing against sear spring with thumb and pulling to the rear). (4) Sear pin (release the pressure on sear pin by standing trigger mechanism vertically on flat forward end, levering sear carrier forward with recoil spring guide inserted just in rear of counter-recoil spring. Then push the sear pin out with the point of a cartridge). Pressure on tail of sear causes sear pin to bind between sear carrier and sear. lever spring. (7) Change lever spring (change lever spring is removed by prying bent over rear end out of its seat with rounded end of sear spring and moving change lever from front to rear. When it is clear of the change lever it is pushed the rest of the way out by pressing with the thumb against the sear stop). Notes on Assembling Trigger Mechanism, 40. The following points are worthy of note: It is easier to seat the magazine catch spring if the ejector is moved down until it is flush with the magazine catch spring before attempting to compress the latter. 41. In assembling change lever spring first insert the ears in slots in trigger guard and push spring forward a slight distance, then insert the rounded end of sear spring between the rear end of the trigger guard and the change lever spring. By prying up with the sear spring and, at the same time, pressing against sear stop with thumb and ratcheting change lever from rear to front the change lever spring is easily seated. Sear carrier and counter-recoil spring are assembled to trigger mechanism by inserting counterrecoil spring guide in its seat, then using the recoil spring guide as a lever in sear pin hole, prying the sear carrier forward until its rear end is held by the ears on the change lever spring. The sear is now inserted and the recoil spring guide forced through so as to register the holes in the sear, sear carrier and trigger guard for the sear pin, which is forced in by pressing it against a block of wood, thus- forcing the recoil spring guide out. 42. In assembling the connector note that its toe points to the rear and that its head is in rear of the connector stop (rear is the direction away from the ejector toward the sear). 43. Be especially careful to see that the outside prongs of the sear spring rest on their seats on the sear and that the middle prong rides freely in the slot formed by the walls of the sear carrier. If this middle prong rests on one of these walls, instead of riding freely between them, the trigger mechanism will not function when the barrel is inclined below the horizontal. 46. The men must be taught that the magazines require the same care and preservation as the rifle. They must not be allowed to become dirty. Dented magazines will cause malfunctions. The greatest possible care should be taken to prevent any damage whatever being done to the lips of the magazine or to the notch for the magazine catch. 48. Assemble in reverse order, viz.: Follower, spring and base. Note that bent-over end of follower and eye of spring work against inside of rear (notched) end of magazine. SPARE PARTS. 49. The nomenclature of the spare parts kit will be taught according to the principles hereinbefore enunciated. This instruction will include the proper method of packing the spare parts kit. It will also include instruction in the contents of the gun box. Breakages and losses must be reported immediately. Noncommissioned instructors will check their own spare parts at the beginning and end of the instruction and will render a report showing deficiencies. parts box. Where any rifles are kept in reserve care should be taken to see that they are in the same condition of readiness for action as those to be used in the firing line. They should not be utilized as a source for obtaining spare parts. FUNCTIONING. 51. Introduction. — The instructor will give a brief lecture, explaining the difference between recoil operated and gas operated guns, that most automatic weapons have some sort of a cooling system and the reasons thereof (it will be noted that there is no special device for cooling the Browning automatic rifle but that the barrel is exposed as much as possible to the air). He will further explain that all automatic weapons must have mechanical means for performing the following functions: Extraction, ejection, feeding, locking breech while there is high pressure in the bore and priming the cartridge. He will define and illustrate any mechanical terms which he uses. For instance "to cam" is to change the direction of motion of a part by means of a cam. Instructor may illustrate this by showing how the bolt supports act on the bolt lock during the operation of locking. 52. The operations of extraction, ejection, etc., are performed by various cams, lugs and springs and the energy necessary to perform this work and overcome friction in the rifle is derived from the explosion of the powder in the chamber. He will explain that these operations have a certain sequence in the various guns and that some of them are concurrent, that in the Browning the men will be expected to learn and understand thoroughly the various operations separately and then to visualize them as they are actually happening in the rifle during firing. In other words, that the soldier must be able to "see" the relative position of all the parts, at any time, of the operation of the rifle. 53. Explanation-demonstration. — This explanation-demonstration will be illustrated with an assembled rifle, parts of rifles and drawings, in the following order: 56. It is not desired to have the student memorize the distances given below. He must have, however, an approximate idea of these distances; for instance, he should understand that the backward travel of the bolt has been very little when the bolt lock is drawn completely down but, on the other hand, that the slide has moved a considerable distance. 57. The functioning of the Browning automatic rifle is divided into two phases, based on the natural operation of the mechanism when a shot is fired. These two phases are the backward and the forward action. In making this division we assume, as a starting or reference point, the priming of a cartridge in the chamber. Action of Gas. 58. A cartridge having been primed, the bullet, under the pressure of the expanding powder gases, travels through the barrel and when it reaches a point 6 inches from the muzzle it passes a port in the bottom of the barrel. The barrel pressure, which at this instant is still very high, seeks this first natural vent. Registered with the barrel port are other similar ports in the gas cylinder tube bracket, gas cylinder tube and gas cylinder. The port in the gas cylinder is the smallest and serves to throttle the barrel pressure. The ports in the gas cylinder lead radially into a well about ,12 of an inch in diameter in the head of the gas cylinder. The throttled barrel pressure is conducted through this well to the gas piston plug. This pressure acts on the piston a very short time, namely, the time it takes the bullet to travel the 6 inch distance from the barrel port to the muzzle. Its effect is that of a sudden severe blow on the piston plug. Under the influence of this blow the gas piston is driven to the rear and carries with it the slide to which it is assembled. When the piston has travelled about .58 of an inch backward the bearing rings on its head, also the gas piston plug, pass out of the cylinder. The gas expands around the piston head and into the gas cylinder tube and is exhausted through six port holes in the tube just in rear of the gas cylinder tube bracket. The gas is prevented, in a large measure, from travelling back through the gas cylinder tube by two rings on the piston, .62 of an inch apart and 1.25 inches from the piston head. These rings also serve as bearings to hold the front end of the piston in the center of the gas cylinder tube after the piston head has passed out of the gas cylinder. The Slide. 59. Having traced out the action of the gas we will now go back and take up the action of the mechanism as it moves to the rear. The first and immediate result of the backward movement of the slide is the beginning of the compression of the recoil spring, thereby storing energy for the forward motion. Unlocking. 60. The hammer pin is slightly in advance of the link pin, about .19 of an inch. The center rib of the hammer is against the head of the firing pin. When the slide begins its motion to the rear it imparts no motion whatever to the bolt and bolt lock. The slide moves back .19 of an inch and its only effect during this travel is to carry the hammer from the firing pin and the hammer pin directly under the link pin. At this point the unlocking begins, the link revolves forward about the hammer pin drawing the bolt lock down and to the rear. The motion of the lock and bolt, which is zero at the instant the hammer pin passes under the link pin, accelerates from this point until the slide has travelled 1.19 inches, at which point the lock is drawn completely down out of the locking recess and away from the locking shoulder of the receiver. It is now supported in front on the bolt supports -and the front upper shoulder of the link has revolved forward and is against the locking shoulder of the bolt lock. These two influences prevent the bolt lock revolving down below the line of backward travel of the bolt. Withdrawal of Firing Pin. 61. As the bolt lock revolves down from its locked position a cam surface in a slot in the rear bottom side of the bolt lock comes in contact with a similar cam surface on the firing pin lug and cams the firing pin from the primer. Extraction. 62. The backward motion of the bolt begins when the bolt lock has been drawn down so that the circular cam surface on its under side is operating on the rear shoulders of the bolt supports. This produces a strong lever action which slowly loosens the cartridge case if stuck in the chamber. The backward travel of the bolt has been slight, only .17 of an inch when the firing pin is withdrawn, its travel is .35 of an inch when the bolt lock is drawn completely down. From this point the bolt moves to the rear, drawn by the bolt lock and link, with the same speed as the slide and carries with it the empty cartridge case, which is held firmly in its seat on the face of the bolt by the extractor. The extractor is on the upper righthand side of the bolt next to the ejection opening in the receiver. A slot cut in the left side of the bolt lock near the back end passes over the bolt guide, which supports the bolt lock and bolt when they are in the cocked position. 63. When the slide reaches a point .22 of an inch from the end of its travel, the base of the cartridge case strikes the ejector, which is on the left side of the feed rib of the bolt and opposite the extractor. This action causes the cartridge case to be pivoted with considerable force about the extractor as a pivot and through the ejection opening, in the receiver. The front end of the cartridge case passes first out of the receiver and is pivoted backward so that it strikes the receiver at a point about 1 inch in rear of the ejection opening. It rebounds from the receiver toward the right front. Termination of First Phase. 64. The backward motion is terminated by the rear end of slide striking the buffer at the back end of the receiver. The slide moves forward .10 of an inch, after striking the buffer, under the action of the recoil spring, but if the sear nose is not depressed it engages the sear notch on the slide and the piece is cocked for the next shot. NOTE. — It was seen that the motion of the bolt and lock and link mechanism began slowly at first and did not attain the speed of the slide until the slide had travelled 1.2 inches backward. This is a very important and good characteristic of the rifle because it relieves the mechanism of the excess strain which it would have if those parts were started suddenly at the instant the gas impinges on the piston. Another very important result of this characteristic of the design is the delaying of the opening of the chamber an instant of time to allow the high barrel pressure to decrease. Action of Recoil Spring. 65. The sear nose is depressed, disengaging the sear and the slide moves forward under the action of the recoil spring. The link pin is slightly below a line joining the bolt lock pin and the hammer pin, therefore, as the slide starts forward, the joint at the link pin has a tendency to buckle downward. It is prevented from doing this by the tail of the feed rib of the bolt, which extends backward under the bolt lock, also principally by the upper front shoulder of the link being in contact with the locking surface of the bolt lock. Since the joint cannot buckle, the entire mechanism moves forward with the "slide. When it has travelled .27 of an inch the front end of the feed rib impinges on the base of the cartridge which the magazine spring and lips are holding up in its path. Feeding. 66. The cartridge is carried forward about .27 of an inch, when the nose of the bullet strikes the bullet ramp or guide on the breech of barrel and is deflected upward towards the chamber. This action also guides the front end of the cartridge from under the magazine lips. The base of the cartridge approaches the center of the magazine, where the lips are cut away and the opening enlarged, and at this point is forced out of the magazine by the magazine spring. The base of the cartridge slides across the face of the bolt and under the extractor. . Should the cartridge fail to slide under the extractor the extractor will snap over its head when the bolt is in the forward position. When the cartridge is released by the magazine the nose of the bullet is so far in the chamber that it is guided by the chamber •from this point on. 67. When the slide is 1.19 inches from its forward position the circular cam surface on the under side of the bolt lock begins to ride over the rear shoulders of the bolt supports and the rear end of the bolt lock is cammed upward. The link pin passes up above a line joining the bolt lock pin and hammer pin. fne joint at the link pin now has a tendency to buckle upward and the bolt lock, being opposite the locking recess in the receiver, is free to and does, pivot upward about the bolt lock pin. The link revolves upward about the hammer pin, forcing the bolt lock up and a rounded surface on the bolt lock, just above the locking face, slides over the locking shoulder in the receiver, giving the lock a lever action which forces the bolt home to its final position. The two locking surfaces on the bolt lock and the receiver register as the hammer pin passes under the link pin. Priming the Cartridge. 68. The lug on the firing pin is buried in the slot in rear of the bolt lock at all times except when the bolt lock is against the locking shoulder of the receiver, therefore the firing pin is locked away from the primer during all the backward and forward motion of the bolt. When the hammer pin passes under the link pin the firing pin has just been released by the bolt lock. The slide and hammer move forward about .11 of an inch further and the center rib of the hammer strikes the head of the firing pin, driving it forward and priming the cartridge. 69. The front end of the slide strikes a shoulder at the rear end of the gas cylinder tube, which terminates the forward motion. The forward motion is not terminated by the hammer on the firing pin. This can be seen by examining the head of the firing pin when the gas cylinder tube is assembled to the receiver and the bolt mechanism is in the inch clearance from its extreme forward position. NOTE. — The locking shoulder of the receiver is inclined forward. Its surface is normal or perpendicular to a line joining it and the bolt lock pin, therefore the shock of the explosion of the cartridge is squarely against it. Attention is also called to the fact that the speed of the bolt mechanism is slowed down gradually from the instant the joint at the link pin is broken upward, until the hammer pin passes under the link pin, when its speed is zero. Action of the Buffer. 70. The buffer system consists of a tube in which are placed successively, from front to rear, the buffer head, a brass friction cup with concave interior and split to allow it to spring. A steel cone to fit into the cup; four of these cups and cones are placed one after the other or in series. Next is the buffer spring and finally the buffer nut, which is screwed into the end of the tube and forms a seat for the spring. 71. The buffer head is struck by the rear end of the slide, this forces the cups over the cones and causes them to expand tightly against the tube and consequently produces considerable friction as the cups move back and compress the buffer spring. Thus the rearward motion of the slide is eased up gradually and there is practically no rebound. The spring causes the buffer head and friction cups and cones to return to their original positions. 76. The trigger mechanism has three settings: (1) Automatic (A). When so set the sear is held depressed as long as the trigger is pulled and the piece will continue firing until the magazine is emptied. (2) Semi-automatic (F). When so set the sear is depressed, thereby disengaging the sear and sear notch when the trigger is pulled, but the mechanism is so constructed that the sear rises and engages in the sear notch when the slide comes back again and the sear and sear notch will not disengage until the trigger is fully released and then pulled. With this setting the piece fires one shot, ejects the empty cartridge and cocks itself for each pull and release of the trigger. from the sear notch by pulling the trigger. 77. The action of the trigger mechanism is taken up in phases and should be followed through on the mechanism itself as the explanation proceeds. Have the trigger guard stripped completely. Study the shape of the change lever and note the following: of the slot. 78. To assemble the change lever and spring to the trigger guard. — Note that the toe of the change lever spring is seated in one of the longitudinal slots on the change lever and that as the lever is turned from one position to another it seats in the other slots. The only function of the spring and the longitudinal slots is to hold the change lever in the position in which it is placed. 79. To assemble the trigger and pin to the guard. — Turn the change lever to rear or safe position. Note that in this position the slot is turned slightly upward and that the full surface of the bar is on the bottom. Pull the trigger. Note that the rear top end of the trigger is slotted longitudinally and that the metal on each side of the slot forms two shoulders that come up against the bottom of the change lever bar. 80. Push the change lever over to the vertical position, which is the automatic setting. Pull the trigger just as before and note that the slot in the change lever is turned to the front and that the two shoulders of the trigger, which before engaged the full surface of the change lever bar, now are free to pass up into the slot of the change lever, also that the little tongue of metal on the bottom of the change lever slot passes through the longitudinal slot in the end of the trigger. 81. Push change lever forward or to single-shot position. Note that now the slot is turned partially down and that when the trigger is pulled the front end of the trigger passes up into the change lever slot, also that the little tongue of metal in the bottom of the change lever slot is now turned back and does not pass through the slot in the end of the trigger as it did in the automatic position. 82. Observe the shape of the connector. Its lower end is shaped like a boot with a toe and heel. It has a flat surface that slopes down and toward the front from the head (sear spring ramp). In rear of the head the profile extends straight downward for about .12 of an inch, then slopes slightly to the rear for .12 of an inch (sear carrier ramp). This last slope is used in a cam action to be explained later. Note the narrow flat top surface of connector. Its function is to raise forward end of sear until cammed out from under latter. 83. Place the connector on the connector pin and change lever on the safe position, pull the trigger and note that the connector is not raised for the obvious reason that trigger itself cannot be raised because the change lever bar is in its way. Turn change lever to automatic position, pull the trigger and note that the head of the connector is raised and held in a vertical position and cannot be tipped forward. The tongue on the change lever engages the toe of the connector as the trigger is pulled and holds the connector upright. 84. Turn the change lever to single shot position, pull the trigger and note that the tongue on the change lever does not now engage the toe of the connector and that the head of the connector can now be tipped forward. the connector stop, also that just in rear of the connector stop and on the under side of the sear carrier is an inclined surface sloping upward in the metal which joins the two sides of the sear carrier. This surface has a cam action with the above mentioned cam surface on the connector. 86. Completely assemble the trigger mechanism. Note that the center leaf of the sear spring presses on the front sloping surface of the connector and tends to press the head of the connector backward. Put change lever on safe and pull trigger. Note the head of connector is not raised above the sear carrier for reasons given previously. Therefore, the sear nose is not depressed and hence the safe position. Change over to the automatic position and pull the trigger, the head of the connector is raised and held in the vertical position, thus depressing the sear nose and holding it in this position, which obviously gives automatic fire as long as there are cartridges in the magazine. 87. The tongue on change lever tends to hold connector vertically and the ramp on sear carrier tends to cam connector forward. The forces on connector exerted by these two parts are opposed, hence trigger mechanism is locked when trigger has been pulled enough to release slide. 88. Put change lever on single shot setting, pull trigger slowly. Note that at first the head of the connector rises and thereby depresses the sear nose which allows the slide to go forward and fire a shot. Continuing the squeeze of the trigger, the previously mentioned cam surface on the connector comes in contact with the cam surface of the sear carrier and the head of the connector is cammed forward against the pressure of the center leaf of the sear spring. The connector disengages the front arm of the sear and the two outside leaves of the sear spring depress it and the sear nose is thereby raised up in the path of the slide and engages the sear notch when the slide moves back, thus allowing only one shot to be fired. When the trigger squeeze is released the center leaf of the sear spring presses the head of the connector downward and forward under the front arm of the sear so that when the trigger is pulled again the action is repeated and single shot is fired. 89. In the semi-automatic position the connector stop prevents the head of the connector being tipped so far forward that the sear spring cannot push it back in place when the trigger is released. The only function of the change lever in the semi-automatic position is the limiting of the upward travel of the trigger when its upper rear shoulders strike the top of the slot in the change lever, which in this position is turned down. 90. Introduction. — The instructor will give definition of immediate action (the automatic and instinctive application of a probable remedy for a stoppage, based on the position of the hammer pin, as determined by pulling back operating handle). 91. Demonstration-explanation. — The instructor will demonstrate the four positions of the hammer pin and how to determine its position by pulling back the operating handle until it strikes the hammer pin. 92. Each member of team is required to learn how to determine the position of the hammer pin by setting the slide in the four positions (recoil spring removed and piston held) and then by placing thumb in rear of trigger guard and fingers on operating handle, squeezing operating handle back until it strikes the hammer pin. Students will then be required to state in which position mechanism was stopped. PLATE I. NOTE. — The operating handle is shown in the rearmost phase in each position. In the first position the movement of the operating handle is zero. Stoppages for the various positions may allow the operating handle to strike the hammer pin anywhere within limits shown by brackets and vertical lines above. Explanatory Notes. 94. The following table will be utilized in teaching immediate action, both in classroom and on the range. In class work stoppages will be set up, not in the student's sight and when he inspects the gun he will find the hammer pin and the rifle in such condition as would result if that stoppage occurred during actual firing. On the range these stoppages will be induced so as to occur during firing. 95. Column 1 describes the four positions of the operating handle (when drawn back until it strikes the hammer pin •where same is fixed by stoppage). Plates show rearward position of operating handle for each of the four positions. These positions, which afford a ready indication of the correct immediate action to be performed, must be recognized clearly before instruction proceeds. When this has been accomplished the soldier will be required to learn what these four positions indicate. 96. Column 2 gives a detailed description of the immediate action to be performed by the firer as soon as he has determined the position of the hammer pin by drawing back the operating handle until it strikes the hammer pin. It will be noted that in all four of the positions the first stage of the immediate action is to pull back the operating handle and examine what conies out of the chamber. 97. Column 3 deals with the probable causes of these stoppages. It is of the utmost importance that the instructor does not proceed to this stage until he is assured that every immediate action can be correctly and immediately performed without the slightest hesitation. 98. A thorough knowledge of the causes of temporary stoppages will not only afford a practical knowledge of the working of the rifle, but will also be an aid in the discovery of the cause of any unusual break-down which may occur. 99. It is not wholly necessary to teach the gunners and carriers the method of "setting-up" stoppages but all instructors and assistant instructors should thoroughly understand this phase. (2) Prolonged, which are due to failure of some part that cannot, as a rule, be remedied by the team under fire or without skilled assistance. These necessarily put the gun Out of action for a more or less prolonged period. during firing. Student will fire. When stoppage occurs he will call first position, third position or whatever position he thinks it may be. If he calls the correct position the sergeant-instructor will command immediate action, whereupon the student executes the necessary immediate action. 102. When the student has been thoroughly grounded in immediate action the various stoppages will be set up and he will be required to perform the necessary immediate action in each case without naming it and without command, as soon as the stoppage occurs. This in order to acquire speed and accuracy. (5) Breakages (due to wrong assembly, oversize or undersize parts, burrs, incorrect heat treatment, overheating of parts incident to firing, etc.). (7) Magazine troubles (due to bent or dented magazines, worn magazine catch notch, extraneous matter as blown primer between lips of magazine and top cartridge). 10. Ruptured cartridges (due to excessive head space). Headspace is the distance between the face of the bolt and the head of a standard steel test cartridge. If this distance is excessive, then when the cartridge case is forced against the walls of the chamber by the high pressure, incident to explosion of charge, the head of the cartridge is driven to the rear since it is not properly supported by Jhe bolt. This results in rupture about ^ inch from the base of the cartridge. In effect the action is the same as if the chamber gripped the cartridge case and the head of the cartridge for about Y-2 inch were free to move; since the chamber pressure is 50,000 pounds per square inch, it can be seen why the case is ruptured. If the chamber is dirty and there is any excessive headspace, ruptured cartridges are sure because the case is "gripped" with more friction. By cleaning the cham- her thoroughly and oiling the cartridges this stoppage will be corrected until the headspace becomes very excessive (the case is never pulled apart by extractor). First Position. 104. Failure to feed. — Obstruction (usually a blown primer), between lips of magazine and top cartridge, causes failure of presentation of a cartridge to feed rib and the bolt goes home on an empty chamber. Same result occurs when the magazine catch notch becomes so worn as to permit the magazine to drop down slightly and also when magazine catch breaks. 105. Misfire. — Faulty primer or charge will cause a misfire as will also a broken or short firing pin. Frequently the beginner will mistake a misfire due to an obstruction between the face of the bolt and the breech for one due to a broken firing pin. He should remember that the latter is a first position stoppage and the former a second position stoppage. A misfire due to a broken firing pin will not show any indentation on the primer. The second position stoppage almost invariably shows a slight indentation. 106. Failure to extract. — A stoppage in the first position with an empty case in the chamber is due to insufficient gas. Insufficient gas in turn may be due to the gas ports not being properly registered or being partially clogged, or to excessive friction because of lack of oil and dirty chamber. When there is sufficient gas to properly function the rifle, but the chamber is very dirty, the bolt will be driven back with such force that the extractor will cut through the rim of the cartridge and a third position stoppage will result, because the feed rib goes back and gets a new cartridge and jams it against the head of the one which was left in the chamber. Second Position. 107. Failure to fire. — Cause, obstruction lodging between face of bolt and the breech, thus holding firing pin away from primer. Primer will be slightly dented. This stoppage is typical. When the piece stops in the second position always look for an obstruction either on the face of the bolt or in breech recess where bolt and receiver join. Most frequent obstruction is the blown primer. Often it is difficult to see. Frequently it drops off as the bolt is drawn back. If the stoppage recurs you may be sure that an obstruction is in the rifle between the face of the bolt and the breech or between bolt lock and receiver top-plate. 108. Mechanism wedged fast in second position or beginning of third position. — This is a rare stoppage. Slide cannot be moved forward or back. This stoppage happens when any obstruction gets between one of the bolt supports and the bolt lock during the beginning of the first phase. As the slide is driven to the rear by the force of the explosion the bolt lock is wedged by the obstruction. This stoppage has been caused by blown primers and by a piece of metal broken off from the rear slotted end of the firing pin channel wall. To reduce it, (a) remove trigger mechanism, gas cylinder and recoil spring; (b) tap on. rear end of slide with piece of wood or a pewter hammer until bolt lock locks. Remove obstruction. Do not hammer with steel or iron. 109. Cartridge jam. — Due (a) to deformed cartridge; (b) to loaded cartridge being held out of chamber by empty case which was not extracted; (c) to failure to eject properly, empty case remaining in the ejection opening. Such failure to properly eject is caused by insufficient gas or by failure of extractor to hold cartridge in such position that it will be properly struck by the ejector. Weak extractor spring or burred shoulder of extractor or extraneous matter in seat of shoulder of extractor are the causes of the failure of the extractor to properly hold cartridges for the ejector. This same stoppage will occur when there is insufficient gas to drive the bolt baclt with enough force so that the ejector may be struck with sufficient force by the cartridge to cause ejection. 110. One fourth position stoppage, developed so far, has been in the case of blown primers wedging themselves between the point of the ejector and the face of the bolt, thereby holding the bolt and mechanism back in the fourth position. 111. Another fourth position stoppage is where the piece is cocked and the trigger mechanism will not release the sear when set at (A) or (F). This is due to a broken sear spring, a broken or lost connector, an improper assembling of the sear spring, or to any cause which has the effect of moving the middle prong of the sear spring too far to the front, with respect to the connector, so that the connector is not cammed under tail of sear. the vital necessity for cleaning and caring for the weapon. 113. Explanation-demonstration. — He will explain and demonstrate the care and preservation of the bore, as set forth in the Small Arms Firing Manual (care must be taken not to allow any of these solutions to remain in the rifle, particularly in the gas system). The test given below on points to be observed before, during and after firing, will be explained and demonstrated by the instructor and imitated by the students; the latter will be required to memorize same. They will be questioned as in previous lessons. 120. All members of the rifle squad should be strong, husky men on account of the very heavy equipment of the automatic rifleman. They should be intelligent men and expert shots, otherwise full advantage will not be taken of the great power of this weapon. Who Receives It. 121. All members or tne automatic rifle section should receive such instruction that any one of them will be able to act as gunner and to keep the piece in action should the others be disabled. (10) Such technique and theory of fire as applies to the automatic rifle. This includes auxiliary aiming, use of night firing box, etc. (prescribed elsewhere). From the Shoulder. 123. When fired from the shoulder the position with the Browning automatic rifle, prone, sitting, kneeling and standing, is a modification of that used with the service magazine rifle. 124. When firing with automatic setting (exceptional) the soldier will lean into the piece as he would lean into a strong wind. The effect of the recoil is that of a strong, steady push against the firer. Adjustment of Sling for Marching Fire. 125. The gunner having previously adjusted the sling, as to length, grasps same at the middle with his left hand and allows the rifle to hang by the sling with the barrel down, raises rifle with left hand and slips sling over the head and on to the left shoulder, at the same time passing right hand through the sling and grasping receiver at ejection opening. He then turns rifle counter-clockwise and with the right hand passes rear end of sling to rear and under butt so that it extends from rear sling swivel, along right side of stock, behind the back and over the left shoulder, thence to front sling swivel. (See Plate II). 127. For close order the sling should be of such length as to allow the rifle to be carried behind the right shoulder, with the sling passing over the right shoulder only. For ex- 129. The following position is prescribed for firing while marching. The sling adjusted as described above (paragraph 125), left hand grasps forearm, thumb extended along forearm, sling pulled taut. Right hand just in front of comb of stock with fore-finger in trigger guard. The rifle being firmly supported by the butt support and the sling, directed with the left hand and fired with the right. 130. The above described position should always be used in marching fire when the gunner is provided with a butt support. It has been found, when the butt support is lost or not available, that the gun may be fired while marching by placing the butt of the rifle in the pit of the stomach and supporting the rifle with the sling in a similar manner to that described above. The firer should bend over well at the waist and bend his knees slightly while firing. 131. Firing with the butt of the rifle in the pit of the stomach is an uncomfortable position for some men. The rifle may be fired by adjusting the sling as before, except that it is shortened so as to support the forward end of the rifle when the butt is held under the arm pit. The butt is raised well up under the arm pit and the stock clamped with the right arm. The rifle is pushed forward against the sling until the latter gives it a steady support. 132. Any position but that prescribed in paragraph 129 (from the hip, using butt support), is to be regarded as exceptional and should not be used except when the gunner has no butt support. 133. After the soldier has been thoroughly instructed in the position, while at the halt, he will simulate fire while marching (commands and signals for firing, those prescribed in I. D. R., except as noted hereafter). The gunner advances, firing as either foot strikes the ground and between steps. He keeps his eyes on the target and corrects elevation by observation ©f impact. Scope of Training. 134. The rifle team should be so trained as to get maximum efficiency out of the efforts of the individual members. This requires co-ordination of all their activities. The training should include the following: of the gunner and ammunition carriers. (2) Maneuvering through the various formations of close order drill suitable for use with the automatic rifle team and the thorough training of the gunner and carriers in their duties in each of the several formations. (4) Service of the piece by two members of the team and by one man alone. Exchange of magazines by first and second carriers and loading of magazines while in position. Formation of the Team. 135. For drill, the team is formed in single rank. The team acting alone maneuvers on the gunner as the base. Post of the first carrier is by the gunner's side and on his right. When the team is deployed, the first carrier (loader), .at any command or signal for firing, places his left hand on the gunner's shoulder for the purpose of preserving alignment and interval and transmitting signals. The second carrier (scout) posts himself on a flank five paces to the right or left of the gunner. 136. In action the scout should be on the most exposed flank as a rule. For the purpose of drill-, scouts of front rank teams post themselves on the right of the gunner and scouts of rear rank teams on the left of the gunner. (5) To change empty magazines for full ones. This exchange is made by bandolier or a belt with the scout, corporal and sergeant successively. To Load. 140. Command. — 1. MAGAZINE. At this command the gunner inclines the barrel to the left and releases the magazine catch. He then cocks the piece. The loader habitually marches, when deployed, with a loaded magazine in his right hand, base in palm of hand, thumb pointing in same direction as cartridges. At the command MAGAZINE, he withdraws empty with left hand and, holding it with last two fingers in the palm of the hand, grasps trigger mechanism between thumb and first two fin gers, fingers on left hand side (see Plate IV). Thumb and fingers extend slight distance in front of trigger mechanism so as to assist in guiding the magazine. He inserts and pushes home the loaded magazine with right hand. He then returns empty magazine to pocket and draws out a loaded one which he carries as described above. zines being used throughout. Command. — 1. Magazine, 2. FIRE. At (1) the piece is loaded as prescribed above. At (2) the gunner aims and fires. These commands are repeated as long as the instructor desires. i-J-3. At the first command the team assumes the prone firing position, as already explained, and the gunner sets the sights. At the second command the gunner lays on the target. At the fourth command the gunner begins firing semiautomatically, at rate prescribed, unless a different class of fire has been indicated. During the firing the team performs the duties explained above. At the command cease firing> the rifle is set at safe. Sight leaf is laid down. In other respects the team maintains the prone position. Pieces are held loaded and locked in a position of readiness for an instant resumption of firing. 3. CEASE FIRING. At (1) the gunner brings his piece to the marching fire position and cocks it. The loader places his hand on the gunner's right shoulder. At (2) the team takes up the march (if at the halt) and commences firing, semi-automatic fire. shell hole the gunner and loader clean the piece. Command. — 1, Clean 2, RIFLE. At (2) gunner throws out the cleaning kit and starts stripping the rifle. The first carrier opens kit, strips, cleans and reassembles the gas cylinder tube, gas cylinder, etc. The gunner continues stripping the piece and cleans the barrel (loader should have finished cleaning the gas cylinder assembly by the time the gunner finishes the bore). Loader then cleans the bolt, bolt lock and hammer and starts on the piston and slide. The gunner thoroughly cleans receiver and reassembles bolt mechanism and slide. While the gunner completes assembling the piece the first carrier oils trigger mechanism and packs up cleaning kit. Posts. 147. The squad is formed in close order as prescribed in Infantry Drill Regulations, with a team in each rank. The front rank team is known as team A and the one in the rear rank as team B. MARCH. At (1) the corporal places himself in front of his squad, if not already there. At (2) team A, moving at a run, deploys abreast of and on the right of the corporal, with five-pace interval between skirmishers. Team B, moving at a run, de- paces interval between skirmishers. This deployment places the corporal between his teams, a scout on both flanks and each loader on the right of his gunner. It must be remembered that the posts of the corporal and scout are fixed only for purposes of drill. The squad leader gives the signal ADVANCE BY RUSHES, as prescribed in the I. D. R. and, in addition, holds up one finger if the advance is to be made one man at a time and three fingers spread if it is to be by team. If the advance is by team, the whole team rushes forward at once, maintaining their normal intervals. If the rush is by one man, the scout is the first to go forward. He advances to the position he wishes to occupy, taking advantage of all cover afforded by the terrain or by intervening shell holes. In general, this advance should not be more than fifty yards. With his intrenching tool he prepares a position for the gun and then signals to the gunner "ready." The gunner then advances in the same manner and opens fire as soon as his gun is in position, the scout serving the rifle until the loader arrives. The loader, after picking up all magazines, advances. If the advance is made from a trench or a shell hole each man should leave from a different point, as a sniper might train his sights upon any fixed point of departure, shooting each member as he appears, successively. At (2) the A team gunner opens fire. Just before his. magazine is exhausted the A team loader signals COMMENCE FIRING to the B team; the rifles thus alternate fire. THE SECTION. 156. The section executes the movements and firings as explained for the team and squad. The section leader normally takes post in rear of the center of his section but he may go wherever his presence is needed. 157. Except in marching fire the section will seldom act as a unit, but rather as two squads whose action will be supervised by the sergeant of the section. The duties of the sergeant will thus usually be those pertaining to fire direction rather than fire control. The sergeant, under the orders of the platoon leader, will be responsible for the training of the section. The section leader moves forward through the center of the section. The squad to the right of the section leader marches to the left and follows him in file; the squad to the left marches in like manner to the right. Each section leader then conducts the march of his section in double column of files. The section leader moves forward through the center of the section; the squad to the right of the section leader marches to the left and follows him in file; the squad to the left marches to the right and follows the right squad in file.	15,453	common-pile/pre_1929_books_filtered	technicaltrainin00infarich	public_library	public_library_1929_dolma-0020.json.gz:4420	https://archive.org/download/technicaltrainin00infarich/technicaltrainin00infarich_djvu.txt
vWt7KbKxGVq_Z9Xh	1.9: Our Transformed Selves	1.9: Our Transformed Selves - - Last updated - Save as PDF 10 Managing our publics like pros In the world of mutual influence in which technologies and humans exist, are our selves changing? It would certainly appear so in an online search. Identity construction online is sophisticated and constant; not just a full-time job but an activity occupying all hours of our lives. The need to manage our identities is a new phenomenon – right? Well, mostly. One culture that has been dealing with context collapse as an essential part of their work and lives is celebrity culture. And an increasingly popular strategy for pleasing multiple audiences in various contexts is to post like a celebrity. Enter the phenomenon of microcelebrity , a way of presenting yourself like a celebrity: setting up your profile and “brand” online, gaining followers, and revealing things about yourself in strategic and controlled ways. The goal of microcelebrity is to make your brand – the marketing of yourself – valuable. The entire system around microcelebrity is called “the attention economy,” because with so much information out there vying for people’s attention, anything people choose to look at is perceived as more valuable, including ourselves. Microcelebrity leads social media users like you and I to apply marketing perspectives to our own identities. Microcelebrity is big business . It can make ordinary people famous, as when Youtubers can become household names with lucrative marketing contracts. But more often, microcelebrity helps ordinary users participate in social media culture while managing their contexts with polish. We understand increasingly that our social media presences are like art exhibits of ourselves, and we spend extra time in curating them. Solo Media: Posting for Yourself Student Content, Fall 2020 An interactive H5P element has been excluded from this version of the text. You can view it online here: https://opentextbooks.library.arizona.edu/hrsmwinter2022/?p=111#h5p-51 Social media has become a major part of everyone’s daily life within the last 10 years. Being 20 years old, I grew up without smartphones being invented yet until I was probably 11 or 12 years old. Even then, it was limited in the number of apps that were at your personal disposal during this time. I remember the first-ever social media site that I ever belonged to was Facebook and I rarely used the app, simply just to say I had a profile on the site. The next social media app that I was exposed to was Instagram, and Instagram really changed how social media sites worked in the future. It’s crazy how much the app has changed over the years, not just the format, but how people interact with the app as well as becoming Instagram models or even social media influencers. Social media was never really an important part of my life until I got to high school and then just because everyone else cared how they were portrayed on social media, then all of a sudden I had to care. I would post on my personal Snapchat story of the things that I was doing during the day to try and seem cool or popular. It could have been peer pressure or was I finally being dragged into the world of social media? It wasn’t until I got to college that people do not care about the little things anymore. I started to develop this mindset and just realized that people do not care what you do during your day unless it personally impacts them. I also noticed that so many people want to become a social media influencer because they believe that they live their best lives. Little do most people realize is that social media is all based on what you want people to see unless you become famous and have people consistently watching over your back all the time. Most of the time social media influencers post pictures that show the good things in life, not the hardships. In college social media is still very prevalent. From what I have witnessed it is more so used in Greek Life, than people not associated with Greek Life. For example, what I have noticed around Sorority girl’s Instagram pages is a similar theme to their own personal profile. Even with Fraternity guys, they each have their own personal theme to their page. Is this intentional or is it simply just the culture of being in Greek Life and having an Instagram account? I think it has something to do with that, many people don’t want to be different, they don’t want to stand out. There is nothing wrong with that, but why would you not want to be different? Being different is amazing because it brings out another side of the people that people are not used to seeing and people are generally curious. I recently started taking up photography during quarantine and I have had a blast doing it because I found myself too really love it and share my perspective of the world with others on Instagram. I started posting on my main Instagram page and the love that I received was something that I was not expecting. I was expecting to get hate or just nothing at all, but people who truly care about you are going to show support no matter what you do. This is when it finally hit me that it doesn’t matter how many likes I get on pictures because at the end of the day I have shared what I think is truly beautiful and hopefully I can make somebody’s day better. Self-respect is a huge part of being able to finally let go of everyone’s opinion. It’s not about how much praise or recognition you get from others it is about how you feel about what you uploaded. About the Author I am an African American male who is a sophomore at the University of Arizona. I am an avid photographer and it is one of my passions / hobbies!! Media theorist Alice Marwick has written about a paradox in microcelebrity: As ordinary people are acting more famous, famous people are acting more ordinary. Kim Kardashian presents a selfie of herself and Kanye West in a bathroom; Michelle Obama and Ryan Seacrest mug goofily for a selfie. Graeme Turner called this leveling of the everyday toward celebrity culture and vice versa "the demotic turn" in celebrity culture . “Celebrity culture is increasingly populated by unexceptional people who have become famous and by stars who have been made ordinary,” according to author Joshua Gamson . Social media has accelerated the demotic turn in celebrity. Many people quote Andy Warhol’s comment in the past that each person, no matter how ordinary, would have 15 minutes of fame. Today, technologically connected societies offer a lifetime of potential discovery by audiences. High-profile celebrities perform the masses for the masses. And you all are superstars, to at least a small public. How to be different on social media Student Content, Fall 2020 Social media has and will continue to evolve and with that it will continue have a serious impact on not only my life but the lives of billions in this world. In my life I have decided to strive to have a different presence on social media, being constant in not necessarily posting or using this social media in terms of the “norm” by posting for desired attention or to prove how great my said life is. However, I post things that I care about and you can see in my media that there is a consistency in the media. With that I think what separates myself in a personal aspect of social media is that I have a unique story and perspective. I have something very much worth sharing. I would call this desired media. I have defined desired media as a source of media or media itself that wants the consumer wanting more and leaves them walking away feeling good. I believe personally most of my media is desired media in terms of it makes the consumer feel good, and especially those who know me well can relate with some of the media in their own lives as well, which can help contribute to that desired media. In terms of being different on social media, many many people are trying to be “different” in order to receive fame and accolade for this, however, that is not what being different entails. I would say being different on social media means having a purposeful message and using it with a purpose. For example, using media to promote something you really care about. So in my instance I am an advocate for Phoenix Children’s Hospital and their Cancer and Blood Disorder branch. With that I help promote their fundraisers and then get their message out to those who may not be aware of what their goals are and the impact you can have. Speaking on impact, this can make someone feel good about using their media to better themselves and have an impact on the community. In terms of the culture of social media, it is constantly changing and will continue to change. As we all see the rise of and fall of some social media for example, the ascension of TikTok and even the different cultures on that application in general. You have people and kids that are striving for fame and that is their only goal. Then you have the group that uses it just as something for fun, and that just uses it as a different use and change of pace from other medias. Culture is important when it comes to anything, a workplace culture is what builds that places character and is essential to each workplace. The same goes for social media applications and the use of them. In a world that is constantly finding ways to scrutinize individuals for their success, especially on social media, the culture of social media is something that if the culture is on the right track, so will social media for the most part, and it goes both ways. Overall, in terms of my social media I have learned that having a purpose in using, using it because you genuinely care, and work towards building a good culture are what separates myself in social media and can for you as well. About the Author I am a student at the University of Arizona and I am studying broadcast journalism and sports management. Conclusion Why is it important to know ourselves in order to understand social media? I called this book Humans are Social Media because the development of social media culture, including norms and technological affordances, is wrapped up in you, and me, and other humans. And we are also wrapped up in that culture; as we shape it, it shapes us. I’ve tried to show the ways the partnership between social media technologies and human culture play out in this book. We began with the reverberations of this partnership on identity. We examined our society’s communication practices informing early social media technologies. We looked at how human-created algorithms bounce against human behaviors, reinforcing them but also sometimes being rejected by them. We learned about the ways humans have learned to use social technologies to seek what we want through online activism, branding, and lying. And we looked at the ways our bodies and needs for love play out in the digital landscape, performing new relationships and spectacular selves. I hope this book has helped you to understand how important your role is as a human in a technological revolution. And I hope that you will share what you’ve learned. Core Concepts microcelebrity a way of presenting yourself like a celebrity: setting up your profile and “brand” online, gaining followers, and revealing things about yourself in strategic and controlled ways "the demotic turn" in celebrity culture Graeme Turner’s term for the leveling of the everyday toward celebrity culture and vice versa (Understanding Celebrity, 2004) Core Questions An interactive H5P element has been excluded from this version of the text. You can view it online here: https://opentextbooks.library.arizona.edu/hrsmwinter2022/?p=111#h5p-52 Question for Qualitative Thought: Consider the branding practices on social media of yourself or a non-celebrity acquaintance you know. Compare these practices to an actual brand. Are the practices similar? How does it feel to brand oneself – what is emphasized, and what is left out? Related Content Why losing Kobe Bryant felt like losing a relative or friend (by Edward R. Hirt from The Conversation) Edward R. Hirt , Indiana University On the afternoon of Jan. 26, I was at the Indiana men’s basketball game when a chorus of cellphones in the crowd pinged, alerting them to the news of Kobe Bryant’s death . I was astonished at how quickly fans’ attention switched from the game to utter shock and disbelief at the news of Bryant’s passing. Soon, it seemed like the entire nation was in mourning. Sure, we might expect the basketball world to grieve the passing of one of its all-time greats. But grief came from all corners. The Grammy Awards featured poignant tributes to Bryant. President Donald Trump and former President Barack Obama offered their condolences. People who had never met Bryant told reporters they felt like they had just lost a family member . How can so many be so deeply affected by the death of someone they’ve never even met? Why might some people see Kobe Bryant as a family member? As a social psychologist , I’m not surprised by these reactions. I see three main reasons, grounded in psychology, that explain why Bryant’s death had such a profound effect on so many people. 1. Feelings formed from afar Psychologists Shira Gabriel and Melanie Green have written about how many of us form what are called “ parasocial bonds ” with other people. These tend to be one-way relationships with people whom we’ve never met or interacted with, but nonetheless feel intimately connected to. Although ideas about parasocial bonds were first developed in the 1950s, they’ve garnered a lot of attention over the past couple of decades. For example, loyal fans of Oprah Winfrey and Ellen DeGeneres watch their shows almost every day, with the hosts actively trying to build a warm rapport with their viewers and their audience developing intense feelings of attachment . But interest in parasocial relationships has exploded in the age of social media. People who follow celebrities on Twitter and Instagram get access to their relationships, emotions, opinions, triumphs and travails. Even though it’s a one-way relationship – what are the chances a celebrity actually responds to a fan’s message on social media? – fans can feel a profound level of intimacy with the famous people they follow . Kobe Bryant, with over 15 million followers on Twitter and nearly 20 million followers on Instagram, clearly had a massive following. 2. The ‘what if’ factor Still, there was something about Bryant’s death that seemed particularly tragic. There’s no way to measure whether the outpouring of public grief surpassed that of recent celebrity deaths like Michael Jackson, Prince or Robin Williams. But it’s certainly possible that the unique circumstances surrounding Kobe Bryant’s death evoked stronger emotions. Bryant died in a helicopter during extremely foggy conditions. This can lead to a lot of “what ifs,” otherwise known as “ counterfactual thoughts .” Work by psychologists Daniel Kahneman and Amos Tversky has shown that when we can easily come up with ways to undo an outcome – say, “if it had been a clear day, Kobe would still be alive” – it can intensify the anger, sadness or frustration about a negative event. It makes the death seem that much more random – and make us feel like it never should have happened in the first place. Furthermore, Bryant’s 13-year-old daughter, Gianna , died in the accident, along with seven others. This broadens Bryant’s identity beyond the basketball court, reminding people of his role as a father of four daughters – three of whom will now have to live without their sister and father. 3. It’s about us, not him I’d also add that our grief over Kobe’s death may actually be less about him – and more about us. According to “ terror management theory ,” reminders of our own mortality evoke an existential terror. In response, we search for ways to give our lives meaning and seek comfort and reassurance by connecting with loved ones. I found it striking that following the news of Bryant’s death, his former teammate Shaquille O’Neal said that he had called up several estranged friends in order to make amends. Bryant’s death was a stark reminder that life’s too short to hold onto petty grudges. Similarly, after the loss of loved ones, we’ll often hear people suggest hugging those we love tightly, or living every day to the fullest. Many had felt like they had gotten to know Bryant after watching him play basketball on TV for 20 years. His death was random and tragic, reminding us that we, too, will someday die – and making us wonder what we’ll have to show for our lives. Edward R. Hirt , Professor of Psychological and Brain Sciences, Indiana University This article is republished from The Conversation under a Creative Commons license. Read the original article . Thanks for reading Humans Are Social Media. We’d love to hear from you! One or more interactive elements has been excluded from this version of the text. You can view them online here: https://opentextbooks.library.arizona.edu/hrsmwinter2022/?p=111 Media Attributions - GI1_image_5fced83481088 © Anonymous adapted by Emily Gammons is licensed under a CC BY (Attribution) license - First_Lady_Michelle_Obama_and_Ryan_Seacrest_selfie_Jan_2014 © The White House is licensed under a Public Domain license - SC_image-5fceba50d37a5 © Anonymous adapted by Emily Gammons is licensed under a CC BY (Attribution) license	3,854	common-pile/libretexts_filtered	https://socialsci.libretexts.org/Bookshelves/Communication/Journalism_and_Mass_Communication/Humans_R_Social_Media_(2022)/01%3A_Chapters/1.09%3A_Our_Transformed_Selves	libretexts	libretexts-0000.json.gz:25095	https://socialsci.libretexts.org/Bookshelves/Communication/Journalism_and_Mass_Communication/Humans_R_Social_Media_(2022)/01%3A_Chapters/1.09%3A_Our_Transformed_Selves
HZ5rnFEH8wwlthkh	Introduction to Sociology Lumen/OpenStax	Assignment: Race and Ethnicity This assignment can be found in Google Docs: Introduction to Sociology Assignment: Race and Ethnicity To make your own copy to edit: - If you want a Google Doc: in the file menu of the open document, click “Make a copy.” This will give you your own Google Doc to work from. - If you want a PDF or Word file: in the file menu of the open document, click “Download” and select the file type you would like to have (note: depending on the file type you select, the formatting could get jumbled). <a style="margin-left: 16px;" href="https://docs.google.com/document/d/1vy-T6DtTF-BbMfpVEI7VP_R7w2A4anzYZLXR8Pk4Fu4" target="_blank"	133	common-pile/pressbooks_filtered	https://pressbooks.nscc.ca/lumensociology2/chapter/assignment-race-and-ethnicity/	pressbooks	pressbooks-0000.json.gz:65903	https://pressbooks.nscc.ca/lumensociology2/chapter/assignment-race-and-ethnicity/
WnqdqjI5NWRdZ3eI	13: Trigonometric Functions	13: Trigonometric Functions The trigonometric functions are functions of an angle. and relate the angles of a triangle to the lengths of its sides. They are important in the study of triangles and modeling periodic phenomena, among many other applications. - - 13.0: Prelude to Trigonometric Functions - A function that repeats its values in regular intervals is known as a periodic function. The graphs of such functions show a general shape reflective of a pattern that keeps repeating. This means the graph of the function has the same output at exactly the same place in every cycle. And this translates to all the cycles of the function having exactly the same length. - - 13.1: Angles - An angle is formed from the union of two rays, by keeping the initial side fixed and rotating the terminal side. The amount of rotation determines the measure of the angle. An angle is in standard position if its vertex is at the origin and its initial side lies along the positive x-axis. A positive angle is measured counterclockwise from the initial side and a negative angle is measured clockwise. - - 13.2: Unit Circle - Sine and Cosine Functions - In this section, we will examine this type of revolving motion around a circle. To do so, we need to define the type of circle first, and then place that circle on a coordinate system. Then we can discuss circular motion in terms of the coordinate pairs. - - 13.3: The Other Trigonometric Functions - Trigonometric functions allow us to specify the shapes and proportions of objects independent of exact dimensions. We have already defined the sine and cosine functions of an angle. Though sine and cosine are the trigonometric functions most often used, there are four others. Together they make up the set of six trigonometric functions. In this section, we will investigate the remaining functions. - - 13.4: Right Triangle Trigonometry - We have previously defined the sine and cosine of an angle in terms of the coordinates of a point on the unit circle intersected by the terminal side of the angle. In this section, we will see another way to define trigonometric functions using properties of right triangles. - - 13.R: Trigonometric Functions (Review) - We have previously defined the sine and cosine of an angle in terms of the coordinates of a point on the unit circle intersected by the terminal side of the angle. In this section, we will see another way to define trigonometric functions using properties of right triangles.	553	common-pile/libretexts_filtered	https://math.libretexts.org/Bookshelves/Precalculus/Precalculus_1e_(OpenStax)/13%3A_Trigonometric_Functions	libretexts	libretexts-0000.json.gz:15973	https://math.libretexts.org/Bookshelves/Precalculus/Precalculus_1e_(OpenStax)/13%3A_Trigonometric_Functions
EYUkrqIIUcW8TJpz	Generative AI and Workforce Education: A Faculty Guide	Aviation Maintenance Tech Resources Aviation Maintenance Technology - AI Promises Big Benefits to An Aviation Industry Experiencing Massive Change (2024) - An Empirical Study of the Code Generation of Safety-Critical Software Using LLM (2024) - An interactive conversation with a chatbot: Does ChatGPT know standard phraseology in aviation English? (2023) - Examining the Potential of Generative Language Models for Aviation Safety Analysis: Case Study and Insights Using the Aviation Safety Reporting System (ASRS) (2023) - Generative AI has air cargo potential but should be approached with caution (2024)	114	common-pile/pressbooks_filtered	https://openwa.pressbooks.pub/genaiworkforce/chapter/aviation-maintenance-tech-resources/	pressbooks	pressbooks-0000.json.gz:3289	https://openwa.pressbooks.pub/genaiworkforce/chapter/aviation-maintenance-tech-resources/
0jWBJVoBYTIzA1ZT	Introduction to Web Accessibility	Why Learn About Web Accessibility Types of Disabilities and Associated Barriers Contents To understand where accessibility issues can arise, it is helpful to have a basic understanding of a range of disabilities and their related barriers found in digital content. Not all people with disabilities encounter barriers in digital content, and those with different types of disabilities encounter different types of barriers. For instance, if a person is in a wheelchair, they may encounter no barriers at all in digital content. A person who is blind will experience different barriers than a person with limited vision. Many of the barriers that people with disabilities encounter on the Web are often barriers found in electronic documents and multimedia. Different types of disabilities and some of their commonly associated barriers are described here. Watch the following video to see how students with disabilities experience the Internet. Video: Experiences of Students with Disabilities by Jared Smith In this video, David Berman talks about types of disabilities and their associated barriers. Video: Web Accessibility Matters: Difficulties and Technologies: Avoiding Tradeoffs by davidbermancom People Who Are Blind People who are blind tend to face the most barriers in digital content, given the visual nature of much digital content. They will often use a screen reader to access their computer or device, and they may use a refreshable Braille display to convert text to Braille. Common barriers for this group include: - Visual content that has no text alternative - Functional elements that cannot be controlled with a keyboard - Overly complex or excessive amounts of content - Inability to navigate efficiently within a page of content - Content that is not structured (i.e., missing proper headings) - Inconsistent navigation - Time limits (insufficient time to complete tasks) - Unexpected actions (e.g., redirect when an element receives focus) - Multimedia without audio description For a quick look at how a person who is blind might use a screen reader like JAWS to navigate the Web, watch the following video. Video: Accessing the web using screen reading software by rscnescotland People with Low Vision People with low vision are often able to see digital content if it is magnified. They may use a screen magnification program to increase the size and contrast of the content to make it more visible. They are less likely to use a screen reader than a person who is blind, though in some cases they will. People with low vision may rely on the magnification or text customization features in their web browser or word processor, or they may install other magnification or text reading software. Common barriers for this group include: - Content sized with non-resizable absolute measures - Inconsistent navigation - Images of text that degrade or pixelate when magnified - Low contrast (inability to distinguish text from background) - Time limits (insufficient time to complete tasks) - Unexpected actions (e.g., redirect when an element receives focus) See the following video for a description of some of the common barriers for people with low vision. Video: Creating an accessible web (AD) by the Centre for Inclusive Design People Who Are Deaf or Hard of Hearing Most people who are deaf tend to face barriers when audio content is presented without text-based alternatives, and they encounter relatively few barriers in digital content otherwise. Those who are deaf and blind will face many more barriers, including those described for people who are blind. For those who communicate with American Sign Language (ASL) or other sign languages, like Langue des signes québécoise (LSQ), the written language of a website may produce barriers similar to those faced when reading in a second language. Common barriers for this group include: - Audio without a transcript - Multimedia without captions or transcript - Lack of ASL interpretation (for ASL/Deaf community) People with Mobility-Related Disabilities Mobility-related disabilities are quite varied. As mentioned earlier, one could be limited to a wheelchair for getting around and face no significant barriers in digital content. Those who have limited use of their hands or who have fine motor impairments that limit their ability to target and click elements in digital content with a mouse pointer may not use a mouse at all. Instead, they might rely on a keyboard or their voice to control movement (i.e., speech recognition) through digital content, along with switches to control mouse clicks. Common barriers for this group include: - Clickable areas that are too small - Functional elements that cannot be controlled with a keyboard - Time limits (insufficient time to complete tasks) People with Some Types of Learning or Cognitive Disabilities Learning and cognitive-related disabilities can be as varied as mobility-related disabilities, perhaps more so. These disabilities can range from a mild reading-related disability to very severe cognitive impairments that may result in limited use of language and difficulty processing complex information. For most of the disabilities in this range, there are some common barriers and others that only affect those with more severe cognitive disabilities. Common barriers for this group include: - Use of overly complex/advanced language - Inconsistent navigation - Overly complex or excessive amounts of content - Time limits (insufficient time to complete tasks) - Unstructured content (no visible headings, sections, topics, etc.) - Unexpected actions (e.g., redirect when an element receives focus) More specific disability-related issues include: - Reading: Text justification (inconsistent spacing between words) - Reading: Images of text (not readable with a text reader) - Visual: Visual content with no text description - Math: Images of math equations (not readable with a math reader) Everyone While we generally think of barriers in terms of access for people with disabilities, there are some barriers that impact all types of users, though these are often thought of in terms of usability. Usability and accessibility go hand-in-hand. Adding accessibility features improves usability for others. Many people, including those who do not consider themselves to have a specific disability (such as those over the age of 50) may find themselves experiencing typical age-related loss of sight, hearing, or cognitive ability. Those with varying levels of colour blindness may also fall into this group. Some of these usability issues include: - Link text that does not describe the destination or function of the link - Overly complex content - Inconsistent navigation - Low contrast - Unstructured content Suggested Reading: To learn more about disabilities and associated barriers, read How People with Disabilities Use the Web.	1,393	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/iwacc/chapter/types-of-disabilities-and-associated-barriers/	pressbooks	pressbooks-0000.json.gz:24472	https://pressbooks.library.torontomu.ca/iwacc/chapter/types-of-disabilities-and-associated-barriers/
AJTyTnCPvMN4wZ2l	3.3: Attitudes Towards Aging	3.3: Attitudes Towards Aging Ideas about the elderly are often based upon stereotypes and depictions of older adults in the media. Older people are often shown to be helpless, forgetful, slow, have dementia, to be incontinent (unable to hold their bladder), unable to live on their own, and to be unable to engage in physical inactivity. In actuality, research shows that the majority of older people are active and very involved in life activities. In the media, elderly people are often referred to as “cute” with younger people calling them “honey”, “dear” and “sweetheart.” These terms are often condescending and should never be used to refer to an elderly patient. Home Health Aides/Personal Care Aides should always address their patient with their last name and title, such as Mr. or Mrs., unless they request otherwise. Speak with elderly patients with respect and allow them to make their own decisions and choices as much as possible. Do not treat them like a child. Just because they may be dependent on others for their care as a child is does not mean they are children. It just means they need a little extra help. Magazine and television advertisements focus on youth and often equate it with beauty. Numerous products advertising their use will result in a more youthful appearance or help a person live longer is nearly an obsession in many cultures (US Department of Health and Human Services, National Institutes of Health on Aging, 2011). This leaves the impression that young=beautiful and good, while old=ugly and bad. These stereotypes result in what is called ageism. Racism as we discussed in Module Two is discrimination based on someone ‘ s race . Ageism is discrimination against someone based on their age . Ageism is harmful to older people and can result in depression, anger, loss of employment, loss of housing, and loss of emotional support. 1. This term means discrimination against someone based on their age. a). Ageism b). Racism c). Sexism 2. This term means discrimination based on someone’s gender. a). Ageism b). Racism c). Sexism 3. Calling elderly people names such as “honey”, “sweetie”, and “dear”, “cutie” can be condescending and shows a lack of respect for the person. True or False . ________ - Answer - 1. A 2. C 3. True Feedback: 1. Discrimination based on age is called ageism and is harmful to people. 2. Discrimination based on a person’s gender (male or female) is known as sexism. This is harmful to people. 3. Using words such as “honey” or “dear” to refer to an older person rather than their given or preferred name demonstrates a lack of respect. Health care workers should never do this.[/hidden-answer] Myths of Aging According to Mauk (2008), by the year 2030, about 20% (71 million people) of the U.S. population will be over the age of 65. As many of the patients with whom the Home Health Aide/Personal Care Aide will be working will be elderly, it is important to learn about the aging process and to avoid engaging in ageism . Check your stereotypes about the aging process! This activity has been adapted from the Oregon Department of Human Services’ Myths and Stereotypes of Aging booklet, which can be found at: http :// www . oregon . gov / dhs / apd – dd – training / EQC % 20 Training % 20 Documents / Myths % 20 and % 20 Stereotypes % 20 of %20 Aging . pdf True or False ? 1. The elderly are all alike. True or False . _________ 2. Most elderly people are senile or have dementia. True or False . _________ 3. The elderly have no worries once they retire as they can enjoy their life. True or False . _________ 4. True or False . _________ 5. Most elderly people are “set in their ways” and will not change. True or False . _________ 6. Elderly people are unproductive and uncreative. True or False . _________ 7. The elderly have a difficult time learning and are less intelligent than younger people. True or False . _________ 8. Elderly people are grouchy and hard to get along with. True or False . _________ 9. Most older people fall from time to time. True or False . _________ 10. Most elderly people are incontinent (unable to control their bowels or bladder). True or False . _________ - Answer - All of these statements are false Feedback: 1. As we age, we actually become more different. This is due to our unique life experiences. As is any other age group, the elderly are a diverse group. 2. Dementia is not a normal part of aging. Signs of confusion and changes in mental status in older adults should be looked into immediately. They can be a sign of a urinary tract infection, dehydration, stroke, or medication interaction or side effect. Most elderly people do not have dementia. This is a common stereotype presented in the media. 3. Many elderly people have many worries as they age. They may face poverty, loss of social stature, loss of social connections, health problems, and loss of independence. 4. Sexual desire and relationships do not decrease with age. The media and society often believe that older people should not have sex. This could result in feelings of guilt on the elderly person’s part, which could result in the elderly person not having sexual relations as they might wish. Physical problems could also result in the inability to have sexual relations in the way the elderly person used to, but research shows that the majority of elderly people still desire and continue to have sexual relations. 5. While older people may be slower to change their opinion than younger people, the majority of elderly people are open to change. In fact, they face many changes due to changes in physical health, social connections, death of loved ones, and illnesses. 6. many elderly people continue to be productive members of society. Even though many elderly people have retired, some continue to work in order to meet financial obligations or to continue to remain active. Outside of work, elderly people may volunteer within their community, be involved with their families, and serve as caretaker for grandchildren while their children are at work. 7. All age groups learn at a different rate and in different ways. In fact, older people have intelligence from life experiences that younger generations do not. They can offer valued wisdom based on their own life experiences to others around them. Research shows that while we do lose brain cells, we continue to gain new ones and to build new connections within our brain. The best way to build new brain cells is to remain active and continue learning throughout the lifespan. 8. This is another stereotype often seen in the media. People who tend to be grouchy and have a hard time getting along with others when they were younger will likely continue to do so when they are older. Happiness has nothing to do with aging, and in fact, the later years can be some of the happiest times of people’s lives. They may have more freedoms than they did when they were younger and be more confident and secure in themselves than when they were younger. 9. Although fall risk does increase with age, most elderly people do not fall. If a patient falls, the cause of the fall should be investigated. The fall could be due to an infection, medication side effect, or household hazard. 10. Bladder or bowel incontinence can affect people at any age. While the risk of incontinence does increase as people age because of loss of muscle tone, people of any age can suffer from incontinence. It is a stereotype that all elderly people are incontinent. New onset of incontinence should be investigated right away as it could be a sign of a urinary tract infection, medication side effects or electrolyte imbalances.	1,729	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Allied_Health/Foundations_for_Assisting_in_Home_Care_(McLain_O'Hara-Leslie_and_Wade)/03%3A_Working_with_the_Elderly/3.03%3A_Attitudes_Towards_Aging	libretexts	libretexts-0000.json.gz:11986	https://med.libretexts.org/Bookshelves/Allied_Health/Foundations_for_Assisting_in_Home_Care_(McLain_O'Hara-Leslie_and_Wade)/03%3A_Working_with_the_Elderly/3.03%3A_Attitudes_Towards_Aging
YNtAMitwBdE79zwQ	Physical Geology Laboratory	29 Folds Elizabeth Johnson Anatomy of a Fold A fold is a geologic structure that is formed by layers or beds of rock being bent or folded. The plane that marks the center of the fold is called the axial plane. The line which marks where the axial plane intersects the surface of Earth is called the hinge line. The areas on either side of the curved hinge zone stick out like arms or legs, and are appropriately called limbs. Types of Folds There are three main types of folds: anticlines, synclines, and monoclines. Anticline An anticline is a fold that is convex: it curves like a rainbow. “A” is for “anticline,” and the capital letter “A” represents the shape of the fold. 3D interactive model of Figure 22: http://app.visiblegeology.com/model.html#ahFzfnZpc2libGUtZ2VvbG9neXIPCxIFTW9kZWwYic3JmAEM Syncline A syncline is a fold that is concave: it forms a “U” shape. “S” is the first letter of “syncline,” and a syncline looks like a Smile. 3D interactive model of Figure 23: http://app.visiblegeology.com/model.html#ahFzfnZpc2libGUtZ2VvbG9neXIPCxIFTW9kZWwYmZvKmAEM Monocline A monocline is a special type of fold in which both limbs are parallel but offset to each other. The limbs are horizontal, or nearly so. https://en.wikipedia.org/wiki/Monocline#/media/File:Monocline01.svg By Kilom691 – Own work, CC BY-SA 3.0, Link Questions Question 10. What type of fold is this? Click on this link -> https://skfb.ly/WU6y - Anticline - Syncline - Monocline 3D interactive model of Figure 24: http://app.visiblegeology.com/model.html#ahFzfnZpc2libGUtZ2VvbG9neXIPCxIFTW9kZWwYm5vKmAEM Question 11. Which type of fold is shown in Figure 24? - Anticline - Syncline - Monocline Question 12. What is the azimuth of the fold axis in Figure 24? - 0 degrees - 71 degrees - 161 degrees - 341 degrees 3D interactive model of Figure 25: http://app.visiblegeology.com/model.html#ahFzfnZpc2libGUtZ2VvbG9neXIPCxIFTW9kZWwYqb2smQEM Question 13. Which strike and dip symbol is correct in Figure 25? - A - B - C - D References https://en.wikipedia.org/wiki/Monocline#/media/File:Monocline01.svg	391	common-pile/pressbooks_filtered	https://viva.pressbooks.pub/physicalgeologylab/chapter/folds/	pressbooks	pressbooks-0000.json.gz:11728	https://viva.pressbooks.pub/physicalgeologylab/chapter/folds/
7geXCEdxIauDbTcz	Pressbooks @ UO	7 View, Compare, and Restore Revisions Every time you save your chapter, Pressbooks stores a copy of that revision. By clicking ‘Browse’ next to the revision count in the Status & Visibility menu you can view past revisions. You can see who made each revision, when it was saved, and compare or restore old versions. For example: Open Educational Resources (OER) are free and openly licensed course materials, such as free textbooks, that can help ensure that all of your students, regardless of their financial situation have free access to your course materials on the first day of class. OER fit under the larger umbrella of textbook affordability, with the goal of providing a variety of solutions for faculty to minimize the cost of course materials for students, while also maintaining the quality of educational materials and respecting academic freedom. OER include traditional textbooks, lesson plans, videos quizzes and more.	195	common-pile/pressbooks_filtered	https://opentext.uoregon.edu/pressbooksatuo/chapter/view-compare-and-restore-revisions/	pressbooks	pressbooks-0000.json.gz:8495	https://opentext.uoregon.edu/pressbooksatuo/chapter/view-compare-and-restore-revisions/
gjir4sf74o7fy5-i	Farm Engines and How to Run Them: The Young Engineer's Guide	Produced by Chris Curnow, Jennifer Linklater and the Online [Illustration: TRACTION ENGINE.] FARM ENGINES AND HOW TO RUN THEM _THE YOUNG ENGINEER’S GUIDE_ A SIMPLE, PRACTICAL HAND BOOK, FOR EXPERTS AS WELL AS FOR AMATEURS, FULLY DESCRIBING EVERY PART OF AN ENGINE AND BOILER, GIVING FULL DIRECTIONS FOR THE SAFE AND ECONOMICAL MANAGEMENT OF BOTH; ALSO SEVERAL HUNDRED QUESTIONS AND ANSWERS OFTEN GIVEN IN EXAMINATIONS FOR AN ENGINEER’S LICENSE, AND CHAPTERS ON FARM ENGINE ECONOMY, WITH SPECIAL ATTENTION TO TRACTION AND GASOLINE FARM ENGINES, AND A CHAPTER ON _The Science of Successful Threshing_ BY JAMES H. STEPHENSON _And Other Expert Engineers_ WITH NUMEROUS ILLUSTRATIONS SHOWING THE DIFFERENT PARTS OF A BOILER AND ENGINE, AND NEARLY EVERY MAKE OF TRACTION ENGINE, WITH A BRIEF DESCRIPTION OF THE DISTINCTIVE POINTS IN EACH MAKE. CHICAGO FREDERICK J. DRAKE & CO. PUBLISHERS COPYRIGHT, 1903 BY FREDERICK J. DRAKE & CO. CHICAGO, ILL., U.S.A. PREFACE This book makes no pretensions to originality. It has taken the best from every source. The author believes the matter has been arranged in a more simple and effective manner, and that more information has been crowded into these pages than will be found within the pages of any similar book. The professional engineer, in writing a book for young engineers, is likely to forget that the novice is unfamiliar with many terms which are like daily bread to him. The present writers have tried to avoid that pitfall, and to define each term as it naturally needs definition. Moreover, the description of parts and the definitions of terms have preceded any suggestions on operation, the authors believing that the young engineer should become thoroughly familiar with his engine and its manner of working, before he is told what is best to do and not to do. If he is forced on too fast he is likely to get mixed. The test questions at the end of Chapter III. will show how perfectly the preceding pages have been mastered, and the student is not ready to go on till he can answer all these questions readily. The system of questions and answers has its uses and its limitations. The authors have tried to use that system where it would do most good, and employ the straight narrative discussion method where questions could not help and would only interrupt the progress of thought. Little technical matter has been introduced, and that only for practical purposes. The authors have had traction engines in mind for the most part, but the directions will apply equally well to any kind of steam engine. The thanks of the publishers are due to the various traction engine and threshing machine manufacturers for cuts and information, and especially to the _Threshermen’s Review_ for ideas contained in its “Farm Engine Economy,” to the J. I. Case Threshing Machine Co. for the use of copyrighted matter in their “The Science of Successful Threshing,” and to the manager of the Columbus Machine Co. for valuable personal information furnished the authors on gasoline engines and how to run them. The proof has been read and corrected by Mr. T. R. Butman, known in Chicago for 25 years as one of the leading experts on engines and boilers, especially boilers. THE YOUNG ENGINEERS’ GUIDE CHAPTER I. BUYING AN ENGINE. There are a great many makes of good engines on the market to-day, and the competition is so keen that no engine maker can afford to turn out a very poor engine. This is especially true of traction engines. The different styles and types all have their advantages, and are good in their way. For all that, one good engine may be valueless for you, and there are many ways in which you may make a great mistake in purchasing an engine. The following points will help you to choose wisely: 1. Consider what you want an engine for. If it is a stationary engine, consider the work to be done, the space it is to occupy, and what conveniences will save your time. Remember, TIME IS MONEY, and that means that SPACE IS ALSO MONEY. Choose the kind of engine that will be most convenient for the position in which you wish to place it and the purpose or purposes for which you wish to use it. If buying a traction engine, consider also the roads and an engine’s pulling qualities. 2. If you are buying a traction engine for threshing, the first thing to consider is FUEL. Which will be cheapest for you, wood, coal or straw? Is economy of fuel much of an object with you--one that will justify you in greater care and more scientific study of your engine? Other things being equal, the direct flue, firebox, locomotive boiler and simple engine will be the best, since they are the easiest to operate. They are not the most economical under favorable conditions, but a return flue boiler and a compound engine will cost you far more than the possible saving of fuel unless you manage them in a scientific way. Indeed, if not rightly managed they will waste more fuel than the direct flue locomotive boiler and the simple engine. 3. Do not try to economize on the size of your boiler, and at the same time never get too large an engine. If a 6-horse power boiler will just do your work, an 8-horse power will do it better and more economically, because you won’t be overworking it all the time. Engines should seldom be crowded. At the same time you never know when you may want a higher capacity than you have, or how much you may lose by not having it. Of course you don’t want an engine and boiler that are too big, but you should always allow a fair margin above your anticipated requirements. 4. Do not try to economize on appliances. You should have a good pump, a good injector, a good heater, an extra steam gauge, an extra fusible plug ready to put in, a flue expander and a beader. You should also certainly have a good force pump and hose to clean the boiler, and the best oil and grease you can get. Never believe the man who tells you that something not quite the best is just as good. You will find it the most expensive thing you ever tried--if you have wit enough to find out how expensive it is. 5. If you want my personal advice on the proper engine to select for various purposes, I should say by all means get a gasoline engine for small powers about the farm, such as pumping, etc. It is the quickest to start, by far the most economical to operate, and the simplest to manage. The day of the small steam engine is past and will never return, and ten gasoline engines of this kind are sold for every steam engine put out. If you want a traction engine for threshing, etc., stick to steam. Gasoline engines are not very good hill climbers because the application of power is not steady enough; they are not very good to get out of mud holes with for the same reason, and as yet they are not perfected for such purposes. You might use a portable gasoline engine, however, though the application of power is not as steady as with steam and the flywheels are heavy. In choosing a traction steam engine, the direct flue locomotive boiler and simple engine, though theoretically not so economical as the return flue boiler and compound engine, will in many cases prove so practically because they are so much simpler and there is not the chance to go wrong with them that there is with the others. If for any reason you want a very quick steamer, buy an upright. If economy of fuel is very important and you are prepared to make the necessary effort to secure it, a return flue boiler will be a good investment, and a really good compound engine may be. Where a large plant is to be operated and a high power constant and steady energy is demanded, stick to steam, since the gasoline engines of the larger size have not proved so successful, and are certainly by no means so steady; and in such a case the exhaust steam can be used for heating and for various other purposes that will work the greatest economy. For such a plant choose a horizontal tubular boiler, set in masonry, and a compound engine (the latter if you have a scientific engineer). In general, in the traction engine, look to the convenience of arrangement of the throttle, reverse lever, steering wheel, friction clutch, independent pump and injector, all of which should be within easy reach of the footboard, as such an arrangement will save annoyance and often damage when quick action is required. The boiler should be well set; the firebox large, with large grate surface if a locomotive type of boiler is used, and the number of flues should be sufficient to allow good combustion without forced draft. A return flue boiler should have a large main flue, material of the required 5-16-inch thickness, a mud drum, and four to six hand-holes suitably situated for cleaning the boiler. There should be a rather high average boiler pressure, as high pressure is more economical than low. For a simple engine, 80 pounds and for a compound 125 pounds should be minimum. A stationary engine should have a solid foundation built by a mason who understands the business, and should be in a light, dry room--never in a dark cellar or a damp place. Every farm traction engine should have a friction clutch. CHAPTER II. BOILERS. The first boilers were made as a single cylinder of wrought iron set in brick work, with provision for a fire under one end. This was used for many years, but it produced steam very slowly and with great waste of fuel. The first improvement to be made in this was a fire flue running the whole length of the interior of the boiler, with the fire in one end of the flue. This fire flue was entirely surrounded by water. Then a boiler was made with two flues that came together at the smoke-box end. First one flue was fired and then the other, alternately, the clear heat of one burning the smoke of the other when it came into the common passage. The next step was to introduce conical tubes by which the water could circulate through the main fire flue (Galloway boiler). [Illustration: FIG. 1. ORR & SEMBOWER’S STANDARD HORIZONTAL BOILER, WITH FULL-ARCH FRONT SETTING.] The object of all these improvements was to get larger heating surface. To make steam rapidly and economically, the heating surface must be as large as possible. [Illustration: FIG. 2. GAAR, SCOTT & CO.’S LOCOMOTIVE BOILER.] But there is a limit in that the boiler must not be cumbersome, it must carry enough water, and have sufficient space for steam. The stationary boiler now most commonly used is cylindrical, the fire is built in a brick furnace under the sheet and returns through fire tubes running the length of the boiler. (Fig. 1.) LOCOMOTIVE FIRE TUBE TYPE OF BOILER. The earliest of the modern steam boilers to come into use was the locomotive fire tube type, with a special firebox. By reference to the illustration (Fig. 2) you will see that the boiler cylinder is perforated with a number of tubes from 2 to 4 inches in diameter running from the large firebox on the left, through the boiler cylinder filled with water, to the smoke-box on the right, above which the smokestack rises. [Illustration: FIG. 3. THE HUBER FIRE BOX.] It will be noticed that the walls of the firebox are double, and that the water circulates freely all about the firebox as well as all about the fire tubes. The inner walls of the firebox are held firmly in position by stay bolts, as will be seen in Fig. 3, which also shows the position of the grate. [Illustration: FIG. 4. HUBER RETURN FLUE BOILER.] RETURN FLUE TYPE OF BOILER. The return flue type of boiler consists of a large central fire flue running through the boiler cylinder to the smoke box at the front end, which is entirely closed. The smoke passes back through a number of small tubes, and the smokestack is directly over the fire at the rear of the boiler, though there is no communication between the fire at the rear of the boiler and it except through the main flue to the front and back through the small return flues. Fig. 4 illustrates this type of boiler, though it shows but one return flue. The actual number may be seen by the sectional view in Fig. 5. [Illustration: FIG. 5. SECTION VIEW OF HUBER RETURN FLUE BOILER.] The fire is built in one end of the main flue, and is entirely surrounded by water, as will be seen in the illustration. The long passage for the flame and heated gases enables the water to absorb a maximum amount of the heat of combustion. There is also an element of safety in this boiler in that the small flues will be exposed first should the water become low, and less damage will be done than if the large crown sheet of the firebox boiler is exposed, and this large crown sheet is the first thing to be exposed in that type of boiler. WATER TUBE TYPE OF BOILER. The special difference between the fire tube boiler and the water tube boiler is that in the former the fire passes through the tubes, while in the latter the water is in the tubes and the fire passes around them. [Illustration: FIG. 6. FREEMAN VERTICAL BOILER.] In this type of boiler there is an upper cylinder (or more than one) filled with water; a series of small tubes running at an angle from the front or fire door end of the upper cylinder to a point below and back of the grates, where they meet in another cylinder or pipe, which is connected with the other end of the upper cylinder. The portions of the tubes directly over the fire will be hottest, and the water here will become heated and rise to the front end of the upper cylinder, while to fill the space left, colder water is drawn in from the back pipe, from the rear end of the upper cylinder, down to the lower ends of the water tubes, to pass along up through them to the front end again. This type of boiler gives great heating surface, and since the tubes are small they will have ample strength with much thinner walls. Great freedom of circulation is important in this type of boiler, there being no contracted cells in the passage. This is not adapted for a portable engine. UPRIGHT OR VERTICAL TYPE OF BOILER. In the upright type of boiler the boiler cylinder is placed on end, the fire is built at the lower end, which is a firebox surrounded by a water jacket, and the smoke and gases of combustion rise straight up through vertical fire flues. The amount of water carried is relatively small, and the steam space is also small, while the heating surface is relatively large if the boiler is sufficiently tall. You can get up steam in this type of boiler quicker than in any other, and in case of the stationary engine, the space occupied is a minimum. The majority of small stationary engines have this type of boiler, and there is a traction engine with upright boiler which has been widely used, but it is open to the objection that the upper or steam ends of the tubes easily get overheated and so become leaky. There is also often trouble from mud and scale deposits in the water leg, the bottom area of which is very small. DEFINITION OF TERMS USED IN CONNECTION WITH BOILERS. _Shell_--The main cylindrical steel sheets which form the principal part of the boiler. _Boiler-heads_--The ends of the boiler cylinder. _Tube Sheets_--The sheets in which the fire tubes are inserted at each end of the boiler. _Fire-box_--A nearly square space at one end of a boiler, in which the fire is placed. Properly it is surrounded on all sides by a double wall, the space between the two shells of these walls being filled with water. All flat surfaces are securely fastened by stay bolts and crown bars, but cylindrical surfaces are self-bracing. _Water-leg_--The space at sides of fire-box and below it in which water passes. _Crown-sheet_--The sheet of steel at the top of the firebox, just under the water in the boiler. This crown sheet is exposed to severe heat, but so long as it is covered with water, the water will conduct the heat away, and the metal can never become any hotter than the water in the boiler. If, however, it is not covered with water, but only by steam, it quickly becomes overheated, since the steam does not conduct the heat away as the water does. It may become so hot it will soften and sag, but the great danger is that the thin layer of water near this overheated crown sheet will be suddenly turned into a great volume of steam and cause an explosion. If some of the pressure is taken off, this overheated water may suddenly burst into steam and cause an explosion, as the safety valve blows off, for example (since the safety valve relieves some of the pressure). _Smoke-box_--The space at the end of the boiler opposite to that of the fire, in which the smoke may accumulate before passing up the stack in the locomotive type, or through the small flues in the return type of boiler. _Steam-dome_--A drum or projection at the top of the boiler cylinder, forming the highest point which the steam can reach. The steam is taken from the boiler through piping leading from the top of this dome, since at this point it is least likely to be mixed with water, either through foaming or shaking up of the boiler. Even under normal conditions the steam at the top of the dome is drier than anywhere else. _Mud-drum_--A cylindrical-shaped receptacle at the bottom of the boiler similar to the steam-dome at the top, but not so deep. Impurities in the water accumulate here, and it is of great value on a return flue boiler. In a locomotive boiler the mud accumulates in the water leg, below the firebox. _Man-holes_--Are large openings into the interior of a boiler, through which a man may pass to clean out the inside. _Hand-holes_--Are smaller holes at various points in the boiler into which the nozzle of a hose may be introduced for cleaning out the interior. All these openings must be securely covered with steam-tight plates, called man-hole and hand-hole plates. _A boiler jacket_--A non-conducting covering of wood, plaster, hair, rags, felt, paper, asbestos or the like, which prevents the boiler shell from cooling too rapidly through radiation of heat from the steel. These materials are usually held in place against the boiler by sheet iron. An intervening air-space between the jacket and the boiler shell will add to the efficiency of the jacket. _A steam-jacket_--A space around an engine cylinder or the like which may be filled with live steam so as to keep the interior from cooling rapidly. _Ash-pit_--The space directly under the grates, where the ashes accumulate. _Dead-plates_--Solid sheets of steel on which the fire lies the same as on the grates, but with no openings through to the ash-pit. Dead-plates are sometimes used to prevent cold air passing through the fire into the flues, and are common on straw-burning boilers. They should seldom if ever be used on coal or wood firing boilers. _Grate Surface_--The whole space occupied by the grate-bars, usually measured in square feet. _Forced Draft_--A draft produced by any means other than the natural tendency of the heated gases of combustion to rise. For example, a draft caused by letting steam escape into the stack. _Heating Surface_--The entire surface of the boiler exposed to the heat of the fire, or the area of steel or iron sheeting or tubing, on one side of which is water and on the other heated air or gases. _Steam-space_--The cubical contents of the space which may be occupied by steam above the water. _Water-space_--The cubical contents of the space occupied by water below the steam. _Diaphragm-plate_--A perforated plate used in the domes of locomotive boilers to prevent water dashing into the steam supply pipe. A dry-pipe is a pipe with small perforations, used for taking steam from the steam-space, instead of from a dome with diaphragm-plate. THE ATTACHMENTS OF A BOILER.[1] Before proceeding to a consideration of the care and management of a boiler, let us briefly indicate the chief working attachments of a boiler. Unless the nature and uses of these attachments are fully understood, it will be impossible to handle the boiler in a thoroughly safe and scientific fashion, though some engineers do handle boilers without knowing all about these attachments. Their ignorance in many cases costs them their lives and the lives of others. Footnote 1: Unless otherwise indicated, cuts of fittings show those manufactured by the Lunkenheimer Co., Cincinnati, Ohio. The first duty of the engineer is to see that the boiler is filled with water. This he usually does by looking at the glass water-gauge. THE WATER GAUGE AND COCKS. [Illustration: TWO-ROD WATER GAUGE.] There is a cock at each end of the glass tube. When these cocks are open the water will pass through the lower into the glass tube, while steam comes through the other. The level of the water in the gauge will then be the same as the level of the water in the boiler, and the water should never fall out of sight below the lower end of the glass, nor rise above the upper end. Below the lower gauge cock there is another cock used for draining the gauge and blowing it off when there is a pressure of steam on. By occasionally opening this cock, allowing the heated water or steam to blow through it, the engineer may always be sure that the passages into the water gauge are not stopped up by any means. By closing the upper cock and opening the lower, the passage into the lower may be cleared by blowing off the drain cock; by closing the lower gauge cock and opening the upper the passage from the steam space may be cleared and tested in the same way when the drain cock is opened. If the glass breaks, both upper and lower gauge cocks should be closed instantly. [Illustration: GAUGE OR TRY COCK.] In addition to the glass water gauge, there are the try-cocks for ascertaining the level of the water in the boiler. There should be two to four of these. They open directly out of the boiler sheet, and by opening them in turn it is possible to tell approximately where the water stands. There should be one cock near the level of the crown sheet, or slightly above it, another about the level of the lower gauge cock, another about the middle of the gauge, another about the level of the upper gauge, and still another, perhaps, a little higher. But one above and one below the water line will be sufficient. If water stands above the level of the cock, it will blow off white mist when opened; if the cock opens from steam-space, it will blow off blue steam when opened. The try-cocks should be opened from time to time in order to be sure the water stands at the proper level in the boiler, for various things may interfere with the working of the glass gauge. Try-cocks are often called gauge cocks. [Illustration: TRY COCK.] THE STEAM GAUGE. The steam gauge is a delicate instrument arranged so as to indicate by a pointer the pounds of pressure which the steam is exerting within the boiler. It is extremely important, and a defect in it may cause much damage. [Illustration: PRESSURE GAUGE.] The steam gauge was invented in 1849 by Eugene Bourdon, of France. He discovered that a flat tube bent in a simple curve, held fast at one end, would expand and contract if made of proper spring material, through the pressure of the water within the tube. The free end operates a clock-work that moves the pointer. It is important that the steam gauge be attached to the boiler by a siphon, or with a knot in the tube, so that the steam may operate on water contained in the tube, and the water cannot become displaced by steam, since steam might interfere with the correct working of the gauge by expanding the gauge tube through its excessive heat. Steam gauges frequently get out of order, and should be tested occasionally. This may conveniently be done by attaching them to a boiler which has a correct gauge already on it. If both register alike, it is probable that both are accurate. [Illustration: STEAM GAUGE SIPHON.] [Illustration: FRONT CYLINDER COCK.] There are also self-testing steam gauges. With all pressure off, the pointer will return to 0. Then a series of weights are arranged which may be hung on the gauge and cause the pointer to indicate corresponding numbers. The chief source of variation is in the loosening of the indicator needle. This shows itself usually when the pressure is off and the pointer does not return exactly to zero. SAFETY VALVE. The safety valve is a valve held in place by a weighted lever[2] or by a spiral spring (on traction engines) or some similar device, and is adjustable by a screw or the like so that it can be set to blow off at a given pressure of steam, usually the rated pressure of the boiler, which on traction engines is from 110 to 130 pounds. The valve is supplied with a handle by which it can be opened, and it should be opened occasionally to make sure it is working all right. When it blows off the steam gauge should be noted to see that it agrees with the pressure for which the safety valve was set. If they do not agree, something is wrong; either the safety valve does not work freely, or the steam gauge does not register accurately. Footnote 2: This kind of safety valve is now being entirely discarded as much more dangerous than the spring or pop valve. [Illustration: SECTIONAL VIEW OF KUNKLE POP VALVE.] [Illustration: SAFETY VALVE.] The cut shows the Kunkle safety valve. To set it, unscrew the jam nut and apply the key to the pressure screw. For more pressure, screw down; for less, unscrew. After having the desired pressure, screw the jam nut down tight on the pressure screw. To regulate the opening and closing of the valve, take the pointed end of a file and apply it to the teeth of the regulator. If valve closes with too much boiler pressure, move the regulator to the left. If with too little, move the regulator to the right. This can be done when the valve is at the point of blowing off. [Illustration: PHANTOM VIEW OF MARSH INDEPENDENT STEAM PUMP.] Other types of valves are managed in a similar way, and exact directions will always be furnished by the manufacturers. FILLING THE BOILER WITH WATER. There are three ways in which a boiler is commonly filled with water. First, before starting a boiler it must be filled with water by hand, or with a hand force-pump. There is usually a filler plug, which must be taken out, and a funnel can be attached in its place. Open one of the gauge cocks to let out the air as the water goes in. When the boiler has a sufficient amount of water, as may be seen by the glass water gauge, replace the filler plug. After steam is up the boiler should be supplied with water by a pump or injector. THE BOILER PUMP. There are two kinds of pumps commonly used on traction engines, the Independent pump, and the Cross-head pump. The Independent pump is virtually an independent engine with pump attached. There are two cylinders, one receiving steam and conveying force to the piston; the other a water cylinder, in which a plunger works, drawing the water into itself by suction and forcing it out through the connection pipe into the boiler by force of steam pressure in the steam cylinder. [Illustration: STRAIGHT GLOBE VALVE.] [Illustration: ANGLE GLOBE VALVE.] It is to be noted that all suction pumps receive their water by reason of the pressure of the atmosphere on the surface of the water in the supply tank or well. This atmospheric pressure is about 15 pounds to the square inch, and is sufficient to support a column of water 28 to 33 feet high, 33 feet being the height of a column of water which the atmosphere will support theoretically at about sea level. At greater altitudes the pressure of the atmosphere decreases. Pumps do not work very well when drawing water from a depth over 20 or 22 feet. Water can be forced to almost any height by pressure of steam on the plunger, and it is taken from deep wells by deep well pumps, which suck the water 20 to 25 feet, and force it the rest of the way by pressure on a plunger. The amount of water pumped is regulated by a cock or globe valve in the suction pipe. A Cross-head boiler pump is a pump attached to the cross-head of an engine. The force of the engine piston is transmitted to the plunger of the pump. The pump portion works exactly the same, whether of the independent or cross-head kind. The cut represents an independent pump that uses the exhaust steam to heat the water as it is pumped (Marsh pump). [Illustration: VALVE WITH INTERNAL SCREW.] Every boiler feed-pump must have at least two check valves. A check valve is a small swinging gate valve (usually) contained in a pipe, and so arranged that when water is flowing in one direction the valve will automatically open to let the water pass, while if water should be forced in the other direction, the valve will automatically close tight and prevent the water from passing. [Illustration: SECTIONAL VIEW OF SWING CHECK VALVE.] There is one check valve in the supply pipe which conducts the water from the tank or well to the pump cylinder. When the plunger is drawn back or raised, a vacuum is created in the pump cylinder and the outside atmospheric pressure forces water through the supply pipe into the cylinder, and the check valve opens to let it pass. When the plunger returns, the check valve closes, and the water is forced into the feed-pipe to the boiler. [Illustration: SECTIONAL VIEW OF CASE HEATER.] There are usually two check valves between the pump cylinder and the boiler, both swinging away from the pump or toward the boiler. In order that the water may flow steadily into the boiler there is an air chamber, which may be partly filled with water at each stroke of the plunger. As the water comes in, the air must be compressed, and as it expands it forces the water through the feed pipe into the boiler in a steady stream. There is one check valve between the pump cylinder and the air chamber, to prevent the water from coming back into the cylinder, and another between the air chamber and the boiler, to prevent the steam pressure forcing itself or the water from the boiler or water heater back into the air chamber. [Illustration: SECTIONAL VIEW OF PENBERTHY INJECTOR.] [Illustration: U. S. AUTOMATIC INJECTOR. (American Injector Co.)] All three of these check valves must work easily and fit tight if the pump is to be serviceable. They usually close with rubber facings which in time will get worn, and dirt is liable to work into the hinge and otherwise prevent tight and easy closing. They can always be opened for inspection, and new ones can be put in when the old are too much worn. Only cold water can be pumped successfully, as steam from hot water will expand, and so prevent a vacuum being formed. Thus no suction will take place to draw the water from the supply source. There should always be a globe valve or cock in the feed pipe near the boiler to make it possible to cut out the check valves when the boiler is under pressure. _It is never to be closed except_ when required for this purpose. Before passing into the boiler the water from the pump goes through the _heater_. This is a small cylinder, with a coil of pipe inside. The feed pipe from the pump is connected with one end of this inner coil of pipe, while the other end of the coil leads into the boiler itself. The exhaust steam from the engine cylinder is admitted into the cylinder and passes around the coil of pipe, afterwards coming out of the smoke stack to help increase the draft. As the feed water passes through this heater it becomes heated nearly to boiling before it enters the boiler, and has no tendency to cool the boiler off. Heating the feed water results in an economy of about 10 per cent. [Illustration: AUTOMATIC INJECTOR.] _The Injector_ is another means of forcing water from a supply tank or well into the boiler, and at the same time heating it, by use of steam from the boiler. It is a necessity when a cross-head pump is used, since such a pump will not work when the engine is shut down. It is useful in any case to heat the water before it goes into the boiler when the engine is not working and there is no exhaust steam for the heater. There are various types of injectors, but they all work on practically the same principle. The steam from the boiler is led through a tapering nozzle to a small chamber into which there is an opening from a water supply pipe. This steam nozzle throws out its spray with great force and creates a partial vacuum in the chamber, causing the water to flow in. As the pressure of the steam has been reduced when it passes into the injector, it cannot, of course, force its way back into the boiler at first, and finds an outlet at the overflow. When the water comes in, however, the steam jet strikes the water and is condensed by it. At the same time it carries the water and the condensed steam along toward the boiler with such force that the back pressure of the boiler is overcome and a stream of heated water is passed into it. In order that the injector may work, its parts must be nicely adjusted, and with varying steam pressures it takes some ingenuity to get it started. Usually the full steam pressure is turned on and the cock admitting the water supply is opened a varying amount according to the pressure. First the valve between the check valve and the boiler should be opened, so that the feed water may enter freely; then open wide the valve next the steam dome, and any other valve between the steam supply pipe and the injector; lastly open the water supply valve. If water appears at the overflow, close the supply valve and open it again, giving it just the proper amount of turn. The injector is regulated by the amount of water admitted. [Illustration: PLAIN WHISTLE.] In setting up an injector of any type, the following rules should be observed: All connecting pipes as straight and short as possible. The internal diameter of all connecting pipes should be the same or greater than the diameter of the hole in the corresponding part of the injector. When there is dirt or particles of wood or other material in the source of water supply, the end of the water supply pipe should be provided with a strainer. Indeed, invariably a strainer should be used. The holes in this strainer must be as small as the smallest opening in the delivery tube, and the total area of the openings in the strainer must be much greater than the area of the water supply (cross-section). The steam should be taken from the highest part of the dome, to avoid carrying any water from the boiler over with it. Wet steam cuts and grooves the steam nozzle. The steam should not be taken from the pipe leading to the engine unless the pipe is quite large. Before using new injectors, after they are fitted to the boiler it is advisable to disconnect them and clean them out well by letting steam blow through them or forcing water through. This will prevent lead or loose scale getting into the injector when in use. Set the injector as low as possible, as it works best with smallest possible lift. _Ejectors and jet pumps_ are used for lifting and forcing water by steam pressure, and are employed in filling tanks, etc. BLAST AND BLOW-OFF DEVICES. In traction engines there is small pipe with a valve, leading into the smoke stack from the boiler. When the valve is opened, the steam allowed to blow off into the smoke stack will create a vacuum and so increase the draft. Blast or blow pipes are used only in starting the fire, and are of little value before the steam pressure reaches 15 pounds or so. The exhaust nozzle from the engine cylinder also leads into the smoke stack, and when the engine is running the exhaust steam is sufficient to keep up the draft without using the blower. _Blow-off cocks_ are used for blowing sediment out of the bottom of a boiler, or blowing scum off the top of the water to prevent foaming. A boiler should never be blown out at high pressure, as there is great danger of injuring it. Better let the boiler cool off somewhat before blowing off. SPARK ARRESTER. Traction engines are supplied as a usual thing with spark arresters if they burn wood or straw. Coal sparks are heavy and have little life, and with some engines no spark arrester is needed. But there is great danger of setting a fire if an engine is run with wood or straw without the spark arrester. [Illustration: DIAMOND SPARK ARRESTER.] Spark arresters are of different types. The most usual form is a large screen dome placed over the top of the stack. This screen must be kept well cleaned by brushing, or the draft of the engine will be impaired by it. In another form of spark arrester, the smoke is made to pass through water, which effectually kills every possible spark. The _Diamond Spark Arrester_ does not interfere with the draft and is so constructed that all sparks are carried by a counter current through a tube into a pail where water is kept. The inverted cone, as shown in cut, is made of steel wire cloth, which permits smoke and gas to escape, but no sparks. There is no possible chance to set fire to anything by sparks. It is adapted to any steam engine that exhausts into the smoke stack. CHAPTER III. THE SIMPLE ENGINE. The engine is the part of a power plant which converts steam pressure into power in such form that it can do work. Properly speaking, the engine has nothing to do with generating steam. That is done exclusively in the boiler, which has already been described. [Illustration: VIEW OF SIMPLE CYLINDER. (J. I. Case Threshing Machine Co.)] The steam engine was invented by James Watt, in England, between 1765 and 1790, and he understood all the essential parts of the engine as now built. It was improved, however, by Seguin, Ericsson, Stephenson, Fulton, and many others. Let us first consider: THE STEAM CYLINDER, ITS PARTS AND CONNECTIONS. The cylinder proper is constructed of a single piece of cast iron bored out smooth. The _cylinder heads_ are the flat discs or caps bolted to the ends of the cylinder itself. Sometimes one cylinder head is cast in the same piece with the engine frame. The _piston_ is a circular disc working back and forth in the cylinder. It is usually a hollow casting, and to make it fit the cylinder steam tight, it is supplied on its circumference with _piston rings_. These are made of slightly larger diameter than the piston, and serve as springs against the sides of the cylinder. The _follower plate_ and bolts cover the piston rings on the piston head and hold them in place. [Illustration: CONNECTING ROD AND CROSS-HEAD. (J. I. Case Threshing Machine Co.)] The _piston rod_ is of wrought iron or steel, and is fitted firmly and rigidly into the piston at one end. It runs from the piston through one head of the cylinder, passing through a steam-tight “stuffing box.” One end of the piston rod is attached to the cross-head. The _cross-head_ works between _guides_, and has _shoes_ above and below. It is practically a joint, necessary in converting straight back and forth motion into rotary. The cross-head itself works straight back and forth, just as the piston does, which is fastened firmly to one end. At the other end is attached the _connecting rod_, which works on a bearing in the cross-head, called the _wrist pin_, or cross-head pin. The _connecting rod_ is wrought iron or steel, working at one end on the bearing known as the wrist pin, and on the other on a bearing called the _crank pin_. The _crank_ is a short lever which transmits the power from the connecting rod to the _crank shaft_. It may also be a disc, called the _crank disc_. [Illustration: CROSS-HEAD. (J. I. Case Threshing Machine Co.)] Let us now return to the steam cylinder itself. The steam leaves the boiler through a pipe leading from the top of the steam dome, and is let on or cut off by the _throttle_ valve, which is usually opened and closed by some sort of lever handle. It passes on to the _Steam-chest_, usually a part of the same casting as the cylinder. It has a cover called the _steam-chest cover_, which is securely bolted in place. The _steam valve_, usually spoken of simply as the _valve_, serves to admit the steam alternately to each end of the cylinder in such a manner that it works the piston back and forth. There are many kinds of valves, the simplest (shown in the diagram) being the D-valve. It slides back and forth on the bottom of the steam-chest, which is called the _valve seat_, and alternately opens and closes the two _steam ports_, which are long, narrow passages through which the steam enters the cylinder, first through one port to one end, then through the other port to the other end. The exhaust steam also passes out at these same ports. The _exhaust chamber_ in the type of engine now under consideration is an opening on the lower side of the valve, and is always open into the _exhaust port_, which connects with the exhaust pipe, which finally discharges itself through the _exhaust nozzle_ into the smoke stack of a locomotive or traction engine, or in other types of engines, into the _condenser_. The valve is worked by the _valve stem_, which works through the valve stem _stuffing-box_. Of course the piston does not work quite the full length of the cylinder, else it would pound against the cylinder heads. The _clearance_ is the distance between the cylinder head at either end and the piston when the piston has reached the limit of its stroke in that direction. In most engines the valve is so set that it opens a trifle just before the piston reaches the limit of its movement in either direction, thus letting some steam in before the piston is ready to move back. This opening, which usually amounts to 1-32 to 3-16 of an inch, is called the _lead_. The steam thus let in before the piston reaches the limit of its stroke forms _cushion_, and helps the piston to reverse its motion without any jar, in an easy and silent manner. Of course the cushion must be as slight as possible and serve its purpose, else it will tend to stop the engine, and result in loss of energy. Some engines have no lead. _Setting a valve_ is adjusting it on its seat so that the lead will be equal at both ends and sufficient for the needs of the engine. By shortening the movement of the valve back and forth, the lead can be increased or diminished. This is usually effected by changing the eccentric or valve gear. The _lap_ of a slide valve is the distance it extends over the edges of the ports when it is at the middle of its travel. Lap on the steam side is called outside lap; lap on the exhaust side is called inside lap. The object of lap is to secure the benefit of working steam expansively. Having lap, the valve closes one steam port before the other is opened, and before the piston has reached the end of its stroke; also of course before the exhaust is opened. Thus for a short time the steam that has been let into the cylinder to drive the piston is shut up with neither inlet nor outlet, and it drives the piston by its own expansive force. When it passes out at the exhaust it has a considerably reduced pressure, and less of its force is wasted. Let us now consider the VALVE GEAR. The mechanism by which the valve is opened and closed is somewhat complicated, as various things are accomplished by it besides simply opening and closing the valve. If an engine has a _reverse lever_, it works through the valve gear; and the _governor_ which regulates the speed of the engine may also operate through the valve gear. It is therefore very important. The simplest valve gear depends for its action on a fixed eccentric. An _eccentric_ consists of a central disc called the _sheave_, keyed to the main shaft at a point to one side of its true center, and a grooved ring or _strap_ surrounding it and sliding loosely around it. The strap is usually made of brass or some anti-friction metal. It is in two parts, which are bolted together so that they can be tightened up as the strap wears. The _eccentric rod_ is either bolted to the strap or forms a single piece with it, and this rod transmits its motion to the valve. It will be seen, therefore, that the eccentric is nothing more than a sort of disc crank, which, however, does not need to be attached to the end of a shaft in the manner of an ordinary crank. The distance between the center of the eccentric sheave and the center of the shaft is called the _throw_ of the eccentric or the _eccentricity_. The eccentric usually conveys its force through a connecting rod to the valve stem, which moves the valve. The first modification of the simple eccentric valve gear is THE REVERSING GEAR. It is very desirable to control the movement of the steam valve, so that if desired the engine may be run in the opposite direction; or the steam force may be brought to bear to stop the engine quickly; or the travel of the valve regulated so that it will let into the cylinder only as much steam as is needed to run the engine when the load is light and the steam pressure in the boiler high. There is a great variety of reversing gears; but we will consider one of the commonest and simplest first. [Illustration: HUBER SINGLE ECCENTRIC REVERSE.] If the eccentric sheave could be slipped around on the shaft to a position opposite to that in which it was keyed to shaft in its ordinary motion, the motion of the valve would be reversed, and it would let steam in front of the advancing end of the piston, which would check its movement, and start it in the opposite direction. The _link gear_, invented by Stephenson, accomplishes this in a natural and easy manner. There are two eccentrics placed just opposite to each other on the crank shaft, their connecting rods terminating in what is called a _link_, through which motion is communicated to the valve stem. The link is a curved slide, one eccentric being connected to one end, the other eccentric to the other end, and the _link-block_, through which motion is conveyed to the valve, slides freely from one end to the other. Lower the link so that the block is opposite the end of the first rod, and the valve will be moved by the corresponding eccentric; raise the link, so that the block is opposite the end of the other rod, and the valve will be moved by the other eccentric. In the middle there would be a dead center, and if the block stopped here, the valve would not move at all. At any intermediate point, the travel of the valve would be correspondingly shortened. [Illustration: VALVE AND LINK REVERSE.] Such is the theoretical effect of a perfect link; but the dead center is not absolute, and the motion of the link is varied by the point at which the rod is attached which lifts and lowers it, and also by the length of this rod. In full gear the block is not allowed to come quite to the end of the link, and this surplus distance is called the _clearance_. The _radius_ of a link is the distance from the center of the driving shaft to the center of the link, and the curve of the link is that of a circle with that radius. The length of the radius may vary considerably, but the point of suspension is important. If a link is suspended by its center, it will certainly cut off steam sooner in the front stroke than in the back. Usually it is suspended from that point which is most used in running the engine. [Illustration: THE WOOLF REVERSE VALVE GEAR.] The _Woolf reversing gear_ employs but one eccentric, to the strap of which is cast an arm having a block pivoted at its end. This block slides in a pivoted guide, the angle of which is controlled by the reverse lever. To the eccentric arm is attached the eccentric rod, which transmits the motion to the valve rod through a rocker arm on simple engines and through a slide, as shown in cut, on compound engines. _The Meyer valve gear_ does not actually reverse an engine, but controls the admission of steam by means of an additional valve riding on the back of the main valve and controlling the cut-off. The main valve is like an ordinary D-valve, except that the steam is not admitted around the ends, but through ports running through the valve, these ports being partially opened or closed by the motion of the riding valve, which is controlled by a separate eccentric. If this riding valve is connected with a governor, it will regulate the speed of an engine; and by the addition of a link the gear may be made reversible. The chief objection to it is the excessive friction of the valves on their seats. GOVERNORS. A governor is a mechanism by which the supply of steam to the cylinder is regulated by revolving balls, or the like, which runs faster or slower as the speed of the engine increases or diminishes. Thus the speed of an engine is regulated to varying loads and conditions. [Illustration: SECTIONAL VIEW SHOWING VALVE OF WATERS GOVERNOR.] The simplest type of governor, and the one commonly used on traction engines, is that which is only a modification of the one invented by Watt. Two balls revolve around a spindle in such a way as to rise when the speed of the engine is high, and fall when it is low, and in rising and falling they open and close a valve similar to the throttle valve. The amount that the governor valve is opened or closed by the rise and fall of the governor balls is usually regulated by a thumb screw at the top or side, or by what is called a handle nut, which is usually held firm by a check nut directly over it, which should be screwed firm against the handle nut. Motion is conveyed to the governor balls by a belt and a band wheel working on a mechanism of metred cogs. There is considerable friction about a governor of this type and much energy is wasted in keeping it going. The valve stem or spindle passes through a steam-tight stuffing box, where it is liable to stick if the packing is too tight; and if this stuffing box leaks steam, there will be immediate loss of power. [Illustration: PICKERING HORIZONTAL GOVERNOR.] Such a governor as has just been described is called a throttle valve governor. On high grade engines the difficulties inherent in this type of governor are overcome by making the governor control, not a valve in the steam supply pipe, but the admission of steam to the steam cylinder through the steam valve and its gear. Such engines are described as having an “automatic cut-off.” Sometimes the governor is attached to the link, sometimes to a separate valve, as in the Meyer gear already described. Usually the governor is attached to the fly-wheel, and consequently governors of this type are called fly-wheel governors. An automatic cut-off governor is from 15 per cent to 20 per cent more effective than a throttle valve governor. CRANK, SHAFT AND JOURNALS. We have already seen how the piston conveys its power through the piston rod, the cross-head, and the connecting rod, to the crank pin and crank, and hence to the shaft. _The key, gib, and strap_ are the effective means by which the connecting rod is attached, first to the wrist pin in the cross-head, and secondly to the crank pin on the crank. The _strap_ is usually made of two or three pieces of wrought iron or steel bolted together so as to hold the _brasses_, which are in two parts and loosely surround the pin. The brasses do not quite meet, and as they wear may be tightened up. This is effected by the _gib_, back of which is the _key_, which is commonly a wedge which may be driven in, or a screw, which presses on the back of the gib, which in turn forces together the brasses; and thus the length of the piston gear is kept uniform in spite of the wear, becoming neither shorter nor longer. When the brasses are so worn that they have been forced together, they must be taken out and filed equally on all four of the meeting ends, and shims, or thin pieces of sheet iron or the like placed back of them to equalize the wear, and prevent the piston gear from being shortened or otherwise altered. [Illustration: CONNECTING ROD AND BOXES. (A. W. Stevens Co.)] The _crank_ is a simple lever attached to the shaft by which the shaft is rotated. There are two types of crank in common use, the side crank, which works by what is virtually a bend in the shaft. There is also what is called the disc crank, a variation of the side crank, in which the power is applied to the circumference of a disc instead of to the end of a lever arm. The _boss_ of a crank is that part which surrounds the shaft and butts against the main bearing, and is usually about twice the diameter of the crank shaft journal. The _web_ of the crank is the portion between the shaft and the pin. To secure noiseless running, the crank pin should be turned with great exactness, and should be set exactly parallel with the direction of the shaft. When the pressure on the pin or any bearing is over 800 pounds per square inch, oil is no longer able to lubricate it properly. Hence the bearing surface should always be large enough to prevent a greater pressure than 800 pounds to the square inch. To secure the proper proportions the crank pin should have a diameter of one-fourth the bore of the cylinder, and its length should be one-third that of the cylinder. The _shaft_ is made of wrought iron or steel, and must not only be able to withstand the twisting motion of the crank, but the bending force of the engine stroke. To prevent bending, the shaft should have a bearing as near the crank as possible. The _journals_ are those portions of the shaft which work in bearings. The main bearings are also called _pedestals_, _pillow blocks_, and _journal boxes_. They usually consist of boxes made of brass or some other anti-friction material carried in iron pedestals. The pillow blocks are usually adjustable. THE FLY-WHEEL. This is a heavy wheel attached to the shaft. Its object is to regulate the variable action of the piston, and to make the motion uniform even when the load is variable. By its inertia it stores energy, which would keep the engine running for some time after the piston ceased to apply any force or power. LUBRICATORS. All bearings must be steadily and effectively lubricated, in order to remove friction as far as possible, or the working power of the engine will be greatly reduced. Besides, without complete and effective lubrication, the bearings will “cut,” or wear in irregular grooves, etc., quickly ruining the engine. Bearings are lubricated through automatic lubricator cups, which hold oil or grease and discharge it uniformly upon the bearing through a suitable hole. [Illustration: THE “DETROIT” ZERO DOUBLE CONNECTION LUBRICATOR. DESCRIPTION. C 1--Body or Oil Reservoir. C 3--Filler Plug. C 4--Water Valve. C 5--Plug for inserting Sight-Feed Glass. C 6--Sight-Feed Drain Stem. C 7--Regulating Valve. C 8--Drain Valve. C 9--Steam Valve. C10--Union Nut. C11--Tail Piece. H--Sight-Feed Glass.] A sight feed ordinary cup permits the drops of oil to be seen as they pass downward through a glass tube, and also the engineer may see how much oil there is in the cup. Such a cup is suitable for all parts of an engine except the crank pin, cross-head, and, of course, the cylinder. The crank pin oiler is an oil cup so arranged as to force oil into the bearing only when the engine is working, and more rapidly as the engine works more rapidly. In one form, which uses liquid oil, the oil stands below a disc, from which is the opening through the shank to the bearing. As the engine speeds up, the centrifugal force tends to force the oil to the top of the cup and so on to the bearing, and the higher the speed the greater the amount of oil thrown into the crank pin. Hard oil or grease has of late been coming into extensive use. It is placed in a compression cup, at the top of which a disc is pressed down by a spring, and also by some kind of a screw. From time to time the screw is tightened up by hand, and the spring automatically forces down the grease. [Illustration: GLASS OIL CUP.] [Illustration: SECTIONAL VIEW IDEAL GREASE CUP.] _The Cylinder Lubricator_ is constructed on a different principle, and uses an entirely different kind of oil, called “cylinder oil.” A sight-feed automatic oiler is so arranged that the oil passes through water drop by drop, so that each drop can be seen behind glass before it passes into the steam pipe leading from the boiler to the cylinder. The oil mingles with the steam and passes into the steam chest, and thence into the cylinder, lubricating the valve and piston. The discharge of the oil may not only be watched, but regulated, and some judgment is necessary to make sure that enough oil is passing into the cylinder to prevent it from cutting. The oil is forced into the steam by the weight of the column of water, since the steam pressure is the same at both ends. There is a small cock by which this water of condensation may be drained off when the engine is shut down in cold weather. Oilers are also injured by straining from heating caused by the steam acting on cold oil when all the cocks are closed. There is a relief cock to prevent this strain, and it should be slightly opened, except when oiler is being filled. [Illustration: ACORN OIL PUMP.] There are a number of different types of oilers, with their cocks arranged in different ways; but the manufacturer always gives diagrams and instructions fully explaining the working of the oiler. Oil pumps serving the same purpose are now often used. DIFFERENTIAL GEAR. The gearing by which the traction wheels of a traction engine are made to drive the engine is an important item. Of course, it is desirable to apply the power of the engine to both traction wheels; yet if both hind wheels were geared stiff, the engine could not turn from a straight line, since in turning one wheel must move faster than the other. The differential or compensating gear is a device to leave both wheels free to move one ahead of the other if occasion requires. The principle is much the same as in case of a rachet on a geared wheel, if power were applied to the ratchet to make the wheel turn; if for any reason the wheel had a tendency of its own to turn faster than the ratchet forced it, it would be free to do so. When corners are turned the power is applied to one wheel only, and the other wheel is permitted to move faster or slower than the wheel to which the gearing applies the power. There are several forms of differential gears, differing largely as to combination of spur or bevel cogs. One of the best known uses four little beveled pinions, which are placed in the main driving wheel as shown in the cut. Beveled cogs work into these on either side of the main wheel. If one traction wheel moves faster than the other these pinions move around and adjust the gears on either side. [Illustration: THE HUBER SPUR COMPENSATING GEAR.] [Illustration: AULTMAN & TAYLOR BEVEL COMPENSATING GEAR.] [Illustration: DIFFERENTIAL GEAR, SHOWING CUSHION SPRINGS AND BEVEL PINION.] FRICTION CLUTCH. The power of an engine is usually applied to the traction wheel by a friction clutch working on the inside of the fly-wheel. (See plan of Frick Engine.) The traction wheels are the two large, broad-rimmed hind wheels, and are provided with projections to give them a firm footing on the road. Traction engines are also provided with mud shoes and wheel cleaning devices for mud and snow. [Illustration: THE FRICK COMPANY TRACTION ENGINE. Plan view of “Eclipse” Traction Engine, showing arrangement of Patent Reverse Gear and Friction Clutch for Driving Pinion.] THE FUSIBLE PLUG. The fusible plug is a simple screw plug, the center of which is bored out and subsequently filled with some other metal that will melt at a lower temperature than steel or iron. This plug is placed in the crown sheet of a locomotive boiler as a precaution for safety. Should the crown sheet become free of water when the fire is very hot, the soft metal in the fusible plug would melt and run out, and the overheated steam would escape into the firebox, putting out the fire and giving the boiler relief so that an explosion would be avoided. In some states a fusible plug is required by law, and one is found in nearly every boiler which has a crown sheet. Return flue boilers and others which do not have crown sheets (as for example the vertical) do not have fusible plugs. To be of value a fusible plug should be renewed or changed once a month. STUFFING BOXES. Any arrangement to make a steam-tight joint about a moving rod, such as a piston rod or steam valve rod, would be called a stuffing box. Usually the stuffing box gives free play to a piston rod or valve rod, without allowing any steam to escape. A stuffing box is also used on a pump piston sometimes, or a compressed air piston. In all these cases it consists of an annular space around the moving rod which can be partly filled by some pliable elastic material such as hemp, cotton, rubber, or the like; and this filling is held in place and made tighter or looser by what is called a gland, which is forced into the partly filled box by screwing up a cap on the outside of the cylinder. Stuffing boxes must be repacked occasionally, since the packing material will get hard and dead, and will either leak steam or cut the rod. CYLINDER COCKS. These cocks are for the purpose of drawing the water formed by condensation of steam out of the cylinder. They should be opened whenever the engine is stopped or started, and should be left open when the engine is shut down, especially in cold weather to prevent freezing of water and consequent damage. Attention to these cocks is very important. These are small cocks arranged about the pump and at other places for the purpose of testing the inside action. By them it is possible to see if the pump is working properly, etc. STEAM INDICATOR. The steam indicator is an instrument that can be attached to either end of a steam cylinder, and will indicate the character of the steam pressure during the entire stroke of the piston. It shows clearly whether the lead is right, how much cushion there is, etc. It is very important in studying the economical use and distribution of steam, expansive force of steam, etc. LIST OF ATTACHMENTS FOR TRACTION ENGINE AND BOILER. The following list of brasses, etc., which are packed with the Case traction engine will be useful for reference in connection with any similar traction engine and boiler. The young engineer should rapidly run over every new engine and locate each of these parts, which will be differently placed on different engines: 1 Steam Gauge with siphon. 1 Safety Valve. 1 Large Lubricator. 1 Small Lubricator for Pump. 1 Glass Water Gauge complete with glass and rods. 2 Gauge Cocks. 1 Whistle. 1 Injector Complete. 1 Globe Valve for Blow-off. 1 Compression Grease Cup for Cross Head. 1 Grease Cup for Crank Pin. 1 Oiler for Reverse Block. 1 Glass Oiler for Guides. 1 Small Oiler for Eccentric Rod. 1 Cylinder Cock (1 is left in place.) 2 Stop Cocks to drain Heater. 1 Stop Cock for Hose Coupling on Pump. 1 Bibb Nose Cock for Pump. 1 Pet Cock for Throttle. 2 Pet Cocks for Steam Cylinder of Pump. 1 Pet Cock for Water Cylinder of Pump. 1 Pet Cock for Feed Pipe from Pump. 1 Pet Cock for Feed Pipe from Injector. 1 Governor Belt. 1 Flue Cleaner. 15 ft. 1 in. Suction Hose. 5 ft. Sprinkling Hose. 1 Strainer for Suction Hose. 1 Strainer for Funnel. 4 ft. 6 in. of in. Hose for Injector. 5 ft. 6 in. of in. Hose for Pump. 2 Nipples ¾×2½ in. for Hose. 2 ¾ in. Hose Clamps. 2 ½ in. Hose Strainers. TEST QUESTIONS ON BOILER AND ENGINE Q. How is the modern stationary fire-flue boiler arranged? Q. How does the locomotive type of boiler differ? Q. What is a return flue boiler? Q. What is a water-tube boiler and how does it differ from a fire-flue tubular boiler? Q. What is a vertical boiler and what are its advantages? Q. What is the shell? Q. What are the boiler heads? Q. What are the tube sheets? Q. What is the firebox? Q. What is the water leg? Q. What is the crown-sheet? Q. Where is the smoke-box located? Q. What is the steam dome intended for? Q. What is the mud-drum for? Q. What are man-holes and hand-holes for? Q. What is a boiler jacket? Q. What is a steam jacket? Q. Where is the ash-pit? Q. What are dead-plates? Q. How is grate surface measured? Q. What is forced draft? Q. How is heating surface measured? Q. What is steam space? Q. What is water space? Q. What is a diaphragm plate? Q. What is the first duty of an engineer in taking charge of a new boiler? Q. What are the water gauge and try cocks for, and how are they placed? Q. What is the steam gauge and how may it be tested? Q. What is a safety valve? Should it be touched by the engineer? How may he test it with the steam gauge? Q. How is a boiler first filled with water? Q. How is it filled when under pressure? Q. What is an independent pump? What is a crosshead pump? Q. What is a check valve, and what is its use, and where located? Q. What is a heater and how does it work? Q. What is an injector, and what is the principle of its operation? Q. Where are the blow-off cocks located? How should they be used? Q. In what cases should spark arrester be used? Q. Who invented the steam engine, and when? Q. What are the essential parts of a steam engine? Q. What is the cylinder, and how is it used? Q. What is the piston, and how does it work? The piston-rings? Q. What is the piston rod and how must it be fastened? Q. What is the crosshead, and how does it move? What are guides or ways? Shoes? Q. What is the connecting rod? Wrist pin? Crank pin? Q. What is the crank? Crank shaft? Q. Where is the throttle valve located, and what does opening and closing it do? Q. What is the steam chest for, and where is it placed? Q. What is a steam valve? Valve seats? Ports? Q. What is the exhaust? Exhaust chamber? Exhaust port? Exhaust nozzle? What is a condenser? Q. How is the valve worked, and what duties does it perform, and how? Q. What is clearance? Q. What is lead? Q. What is cushion? Q. How would you set a valve? What is lap? Q. How is a steam valve moved back and forth in its seat? Q. How may an engine be reversed? Q. What is a governor, and how does it work? Q. What is an eccentric? Eccentric sheave? Strap? Rod? Q. What is the throw of an eccentric? Q. How does the link reversing gear work? Q. How does the Woolf reverse gear work? Q. How does the Meyer valve gear work? Will it reverse an engine? Q. What are the chief difficulties in the working of a governor? Q. What are key, gib, and strap? Brasses? Q. What is the boss of a crank? Web? Q. How may noiseless running of a crank be secured? Q. What are journals? Pedestals? Pillow blocks? Journal boxes? Q. What is the object in having a fly wheel? Q. What different kinds of lubricators are there? Where may hard oil or grease be used? Is the oil used for lubricating the cylinder the same as that used for rest of the engine? Q. How does a cylinder lubricator work? Q. What is differential gear, and what is it for? Q. What is the use of a fusible plug, and how is it arranged? Q. What are stuffing-boxes, and how are they constructed? Q. What are cylinder cocks, and what are they used for? Q. What are pet cocks? Q. What is a steam indicator? CHAPTER IV. HOW TO MANAGE A TRACTION ENGINE BOILER. We will suppose that the young engineer fully understands all parts of the boiler and engine, as explained in the preceding chapters. It is well to run over the questions several times, to make sure that every point has been fully covered and is well understood. We will suppose that you have an engine in good running order. If you have a new engine and it starts off nice and easy (the lone engine without load) with twenty pounds steam pressure in the boiler, you may make up your mind that you have a good engine to handle and one that will give but little trouble. But if it requires fifty or sixty pounds to start it, you want to keep your eyes open, for something is tight. But don’t begin taking the engine to pieces, for you might get more pieces than you know what to do with. Oil every bearing fully, and then start your engine and let it run for a while. Then notice whether you find anything getting warm. If you do, stop and loosen up a very little and start again. If the heating still continues, loosen again as before. But remember, loosen but little at a time, for a box or journal will heat from being too loose as quickly as from being too tight, and if you have found a warm box, don’t let that box take all your attention, but keep your eye on the other bearings. In the case of a new engine, the cylinder rings may be a little tight, and so more steam pressure will be required to start the engine; but this is no fault, for in a day or two they will be working all right if kept well oiled. In starting a new engine trouble sometimes comes from the presence of a coal cinder in some of the boxes, which has worked in during shipment. Before starting a new engine, the boxes and oil holes should therefore be thoroughly cleaned out. For this purpose the engineer should always have some cotton waste or an oiled rag ready for constant use. A new engine should be run slowly and carefully until it is found to be in perfect running order. If you are beginning on an old engine in good running order, the above instructions will not be needed; but it is well to take note of them. Now if your engine is all right, you may run the pressure up to the point of blowing off, which is 100 to 130 pounds, at which most safety valves are set at the factory. It is not uncommon for a new pop to stick, and as the steam runs up it is well to try it by pulling the relief lever. If on letting it go it stops the escaping steam at once, it is all right. If, however, the steam continues to escape the valve sticks in the chamber. Usually a slight tap with a wrench or hammer will stop it at once; but don’t get excited if the steam continues to escape. As long as you have plenty of water in the boiler, and know that you have it, you are all right. STARTING UP A BOILER. Almost the only danger from explosion of a boiler is from not having sufficient water in the boiler. The boiler is filled in the first place, as has already been explained, by hand through a funnel at the filler plug, or by a force pump. The water should stand an inch and a half in the glass of the water gauge before the fire is started. It should be heated up slowly so as not to strain the boiler or connections. When the steam pressure as shown by the steam gauge is ten or fifteen pounds, the blower may be used to increase the draft. If you let the water get above the top of the glass, you are liable to knock out a cylinder head; and if you let the water get below the bottom of the glass, you are likely to explode your boiler. The glass gauge is not to be depended upon, however, for a number of things may happen to interfere with its working. Some one may inadvertently turn off the gauge cocks, and though the water stands at the proper height in the glass, the water in the boiler will be very different. A properly made boiler is supplied with two to four try-cocks, one below the proper water line, and one above it. If there are more than two they will be distributed at suitable points between. When the boiler is under pressure, turn on the lower try-cock and you should get water. You will know it because it will appear as white mist. Then try the upper try-cock, and you will get steam, which will appear blue. NEVER FAIL TO USE THE TRY-COCKS FREQUENTLY. This is necessary not only because you never know when the glass is deceiving you; but if you fail to use them they will get stopped up with lime or mud, and when you need to use them they will not work. In order also to keep the water gauge in proper condition, it should be frequently blown out in the following manner: Shut off the top gauge cock and open the drain cock at the bottom of the gauge. This allows the water and steam to blow through the lower cock of the water gauge, and you know that it is open. Any lime or mud that has begun to accumulate will also be carried off. After allowing the steam to escape a few seconds, shut off the lower gauge cock, and open the upper one, and allow it to blow off about the same time. Then shut the drain cock and open both gauge cocks, when you will see the water seek its level, and you can feel assured that it is reliable and in good working condition. This little operation you should perform every day you run your engine. If you do you will not _think_ you have sufficient water in the boiler, but will _know_. The engineer who always _knows_ he has water in the boiler will not be likely to have an explosion. Especially should you never start your fire in the morning simply because you see water in the gauge. You should _know_ that there is water in the boiler. Now if your pump and boiler are in good working condition, and you leave the globe valve in the supply pipe to the pump open, with the hose in the tank, you will probably come to your engine in the morning and find the boiler nearly full of water, and you will think some one has been tampering with the engine. The truth is, however, that as the steam condensed, a vacuum was formed, and the water flowed in on account of atmospheric pressure, just as it flows into a suction pump when the plunger rises and creates a vacuum in the pump. Check valves are arranged to prevent anything passing out of the boiler, but there is nothing to prevent water passing in. The only other cause of an explosion, beside poor material in the manufacture of the boiler, is too high steam pressure, due to a defective safety valve or imperfect steam gauge. The steam gauge is likely to get out of order in a number of ways, and so is the safety valve. To make sure that both are all right, the one should frequently be tested by the other. The lever of the safety valve should frequently be tried from time to time, to make sure the valve opens and closes easily, and whenever the safety valve blows off, the steam gauge should be noted to see if it indicates the pressure at which the safety has been set. WHEN YOUR ENGINE IS ALL RIGHT, LET IT ALONE. Some engineers are always loosening a nut here, tightening up a box there, adjusting this, altering that. When an engine is all right they keep at it till it is all wrong. As a result they are in trouble most of the time. When an engine is running all right, LET IT ALONE. Don’t think you are not earning your salary because you are merely sitting still and looking on. If you must be at work, keep at it with an oily rag, cleaning and polishing up. That is the way to find out if anything is really the matter. As the practised hand of the skilled engineer goes over an engine, his ears wide open for any peculiarity of sound, anything that is not as it should be will make itself decidedly apparent. On the other hand, an engineer who does not keep his engine clean and bright by constantly passing his hand over it with an oily rag, is certain to overlook something, which perhaps in the end will cost the owner a good many dollars to put right. Says an old engineer[3] we know, “When I see an engineer watching his engine closely while running, I am most certain to see another commendable feature in a good engineer, and that is, when he stops his engine he will pick up a greasy rag and go over his engine carefully, wiping every working part, watching or looking carefully at every point that he touches. If a nut is working loose, he finds it; if a bearing is hot, he finds it; if any part of his engine has been cutting, he finds it. He picks up a greasy rag instead of a wrench, for the engineer that understands his business and attends to it never picks up a wrench unless he has something to do with it.” Footnote 3: J. H. Maggard, author of “Rough and Tumble Engineering,” to whom we are indebted for a number of valuable suggestions in this chapter. This same engineer goes on with some more most excellent advice. Says he: “Now, if your engine runs irregularly, that is, if it runs up to a higher speed than you want, and then runs down, you are likely to say at once, ‘Oh, I know what the trouble is, it is the governor.’ Well, suppose it is. What are you going to do about it? Are you going to shut down at once and go to tinkering with it? No, don’t do that. Stay close to the throttle valve and watch the governor closely. Keep your eye on the governor stem, and when the engine starts off on one of its speed tilts, you will see the stem go down through the stuffing box and then stop and stick in one place until the engine slows down below its regular speed, and it then lets loose and goes up quickly and your engine lopes off again. You have now located the trouble. It is in the stuffing box around the little brass rod or governor stem. The packing has become dry and by loosening it up and applying oil you may remedy the trouble until such time as you can repack it with fresh packing. Candle wick is as good for this purpose as anything you can use. “But if the governor does not act as I have described, and the stem seems to be perfectly free and easy in the box, and the governor still acts queerly, starting off and running fast for a few seconds and then suddenly concluding to take it easy and away goes the engine again, see if the governor belt is all right, and if it is it would be well for you to stop and see if a wheel is not loose. It might be either the little belt wheel or one of the little cog wheels. If you find these are all right, examine the spool on the crank shaft from which the governor is run, and you will probably find it loose. If the engine has been run for any length of time, you will always find the trouble in one of these places; but if it is a new one, the governor valve might work a little tight in the valve chamber, and you may have to take it out and use a little emery paper to take off the rough projections on the valve. Never use a file on this valve if you can get emery paper, and I should advise you always to have some of it with you. It will often come handy.” This is good advice in regard to any trouble you may have with an engine. Watch the affected part closely; think the matter over carefully, and see if you cannot locate the difficulty before you even stop your engine. If you find the trouble and know that you have found it, you will soon be able to correct the defect, and no time will be lost. At the same time you will not ruin your engine by trying all sorts of remedies at random in the thought that you may ultimately hit the right thing. The chances are that before you do hit the right point, you will have put half a dozen other matters wrong, and it will take half a day to get the matter right again. As there are many different types of governors in use, it would be impossible to give exact directions for regulating that would apply to them all; but the following suggestions applying to the Waters governor (one widely used on threshing engines) will give a general idea of the method for all: There are two little brass nuts on the top of the stem of the governor, one a thumb nut and the other a loose jam nut. To increase the speed, loosen the jam nut and then turn the thumb nut back slowly, watching the motion of the engine all the time. When the required speed has been obtained, then tighten up as snug as you can with your fingers (not using a wrench). To decrease the speed, loosen the jam nut as before, running it up a few turns, and then turn down the thumb nut till the speed meets your requirements, when the thumb nut is made fast as before. In any case, be very careful not to press down on the stem when turning the thumb nut, as this will make the engine run a little slower than will be the case when your hand has been removed. If your engine does not start with an open throttle, look to see if the governor stem has not been screwed down tight. This is usually the case with a new engine, which has been screwed down for safety in transportation. WATER FOR THE BOILER. There is nothing that needs such constant watching and is likely to cause so much trouble if it is not cared for, as the supply of water. Hard well water will coat the inside of the boiler with lime and soon reduce its steaming power in a serious degree, to say nothing of stopping up pipes, cocks, etc. At the same time, rain water that is perfectly pure (theoretically) will be found to have a little acid or alkali in it that will eat through the iron or steel and do equal damage. However, an engineer must use what water he can. He cannot have it made to order for him, but he must take it from well, from brook, or cistern, or roadside ditch, as circumstances may require. The problem for the engineer is not to get the best water, but to make the best use of whatever water he can get, always, of course, choosing the best and purest when there is such a thing as choosing. In the first place, all supply pipes in water that is muddy or likely to have sticks, leaves, or the like in it, should be furnished with strainers. If sticks or leaves get into the valve, the expense in time and worry to get them out will be ten times the cost of a strainer. If the water is rain water, and the boiler is a new one, it would be well to put in a little lime to give the iron a slight coating that will protect it from any acid or alkali corrosion. If the water is hard, some compound or sal ammonia should be used. No specific directions can be given, since water is made hard by having different substances dissolved in it, and the right compound or chemical is that which is adapted to the particular substance you are to counteract. An old engineer says his advice is to use no compound at all, but to put a hatful of potatoes in the boiler every morning. Occasionally using rain water for a day or two previous to cleaning is one of the best things in the world to remove and throw down all scale. It beats compounds at every point. It is nature’s remedy for the bad effects of hard water. The important thing, however, is to clean the boiler thoroughly and often. In no case should the lime be allowed to bake on the iron. If it gets thick, the iron or steel is sure to burn, and the lime to bake so hard it will be almost impossible to get it off. But if the boiler is cleaned often, such a thing will not happen. Mud or sediment can be blown off by opening the valve from the mud drum or the firebox at the bottom of the boiler when the pressure is not over 15 or 20 pounds; and at this pressure much of the lime distributed about the boiler may be blown off. But this is not enough. The inside of the boiler should be scraped and thoroughly washed out with a hose and force-pump just as often as the condition of the water requires it. In cleaning the boiler, always be careful to scrape all the lime off the top of the fusible plug. THE PUMP. In order to manage the pump successfully, the young engineer must understand thoroughly its construction as already described. It is also necessary to understand something of the theory of atmospheric pressure, lifting power, and forcing power. First see that the cocks or globe valves (whichever are used) are open both between the boiler and the pump and between the pump and the water supply. The globe valve next the boiler should _never_ be closed, except when examining the boiler check valve. Then open the little pet cock between the two upper horizontal check valves. Be sure that the check valves are in good order, so that water can pass only in one direction. A clear, sharp click of the check valves is certain evidence that the pump is working well. If you cannot hear the click, take a stick or pencil between your teeth at one end, put the other end on the valve, stuff your fingers in your ears, and you will hear the movement of the valve as plainly as if it were a sledge-hammer. The small drain cock between the horizontal check valves is used to drain hot water out of the pump in starting, for a pump will never work well with hot water in it; and to drain off all water in closing down in cold weather, to prevent damage from freezing. It also assists in testing the working of the pump. In starting up it may be left open. If water flows from the drain cock, we know the pump is working all right, and then close the drain cock. If you are at any time in doubt as to whether water is going into the boiler properly, you may open this drain cock and see if cold water flows freely. If it does, everything is working as it should. If hot water appears, you may know something is wrong. Also, to test the pump, place your hand on the two check valves, and if they are cold, the pump is all right; if they are hot, something is wrong, since the heat must come from the boiler, and no hot water or steam should ever be allowed to pass from the boiler back to the pump. A stop cock next the boiler is decidedly preferable to a globe valve, since you can tell if it is open by simply looking at it; whereas you must put your hand on a globe valve and turn it. Trouble often arises through inadvertently closing the valve or cock next the boiler, in which case, of course, no water can pass into the boiler, and the pump is likely to be ruined, since the water must get out somewhere. Some part of the pump would be sure to burst if worked against a closed boiler cock or valve. Should the pump suddenly cease to work or stop, first see if you have any water in the tank. If there is water, stoppage may be due to air in the pump chamber, which can get in only through the stuffing-box. If this is true, tighten up the pump plunger stuffing-box nut a little. If now the pump starts off well, you have found the difficulty; but at the first opportunity you ought to repack the stuffing-box. If the stuffing-box is all right, examine the supply suction hose. See that nothing is clogging the strainer, and ascertain whether the water is sucked in or not. If it is sucked in and then is forced out again (which you can ascertain by holding your hand lightly over the suction pipe), you may know something is the matter with the first check valve. Probably a stick or stone has gotten into it and prevents it from shutting down. If there is no suction, examine the second check valve. If there is something under it that prevents its closing, the water will flow back into the pump chamber again as soon as the plunger is drawn back. You can always tell whether the trouble is in the second check or in the hot water check valve by opening the little drain cock. If hot water flows from it, you may know that the hot water check valve is out of order; if only cold water flows, you may be pretty sure the hot water check is all right. If there is any reason to suspect the hot water check valve, close the stop cock or valve next the boiler before you touch the check in any way. To tamper with the hot water check while the steam pressure is upon it would be highly dangerous, for you are liable to get badly burned with escaping steam or hot water. At the same time, be very sure the stop cock or valve next the boiler is open again before you start the pump. Another reason for check valves refusing to work besides having something under them, is that the valve may stick in the valve chamber because of a rough place in the chamber, or a little projection on the valve. Light tapping with a wrench may remedy the matter. If that does not work, try the following plan suggested by an old engineer[4]: “Take the valve out, bore a hole in a board about one-half inch deep, and large enough to permit the valve to be turned. Drop a little emery dust in this hole. If you haven’t any emery dust, scrape some grit from a whetstone. If you have no whetstone, put some fine sand or gritty soil in the hole, put the valve on top of it, put your brace on the valve and turn it vigorously for a few minutes, and you will remove all roughness.” Footnote 4: J. H. Maggard. Sometimes the burr on the valve comes from long use; but the above treatment will make it as good as new. INJECTORS. All injectors are greatly affected by conditions, such as the lift, the steam pressure, the temperature of the water, etc. An injector will not use hot water well, if at all. As the lift is greater, the steam pressure required to start is greater, and at the same time the highest steam pressure under which the injector will work at all is greatly decreased. The same applies to the lifting of warm water: the higher the temperature, the greater the steam pressure required to start, and the less the steam pressure which can be used as a maximum. It is important for the sake of economy to use the right sized injector. Before buying a new injector, find out first how much water you need for your boiler, and then buy an injector of about the capacity required, though of course an injector must always have a maximum capacity in excess of what will be required. If the feed water is cold, a good injector ought to start with 25 pounds steam pressure and work up to 150 pounds for a 2-foot lift. If the lift is eight feet, it will start at 30 pounds and work up to 130. If the water is heated to 100 degrees Fahrenheit it will start for a 2-foot lift with 26 pounds and work up to 120 pounds, or for an 8-foot lift, it will start with 33 pounds and work up to 100. These figures apply to the single tube injector. The double tube injector should work from 14 pounds to 250, and from 15 to 210 under same conditions as above. The double tube injector is not commonly used on farm engines, however. Care should be taken that the injector is not so near the boiler as to become heated, else it will not work. If it gets too hot, it must be cooled by pouring cold water on the outside, first having covered it with a cloth to hold the water. If the injector is cool, and the steam pressure and lift are all right, and still the injector does not work, you may be sure there is some obstruction somewhere. Shut off the steam from the boiler, and run a fine wire down through the cone valve or cylinder valve, after having removed the cap or plug nut. Starting an injector always requires some skill, and injectors differ. Some start by manipulating the steam valve; some require that the steam be turned on first, and then the water turned on in just the right amount, usually with a quick short twist of the supply valve. Often some patience is required to get just the right turn on it so that it will start. Of course you must be sure that all joints are air-tight, else the injector will not work under any conditions. Never use an injector where a pump can be used, as the injector is much more wasteful of steam. It is for an emergency or to throw water in a boiler when engine is not running. No lubricator is needed on an injector. THE HEATER. The construction of the heater has already been explained. It has two check valves, one on the side of the pump and one on the side of the boiler, both opening toward the boiler. The exhaust steam is usually at a temperature of 215 to 220 degrees when it enters the heater chamber, and heats the water nearly or quite to boiling point as it passes through. The injector heats the water almost as hot. The heater requires little attention, and the check valves seldom get out of order. The pump is to be used when the engine is running, and the injector when the engine is closed down. The pump is the more economical; but when the engine is not working the exhaust steam is not sufficient to heat the water in the heater; and pumping cold water into the boiler will quickly bring down the pressure and injure the boiler. ECONOMICAL FIRING. The management of the fire is one of the most important things in running a steam engine. On it depend two things of the greatest consequence--success in getting up steam quickly and keeping it at a steady pressure under all conditions; and economy in the use of fuel. An engineer who understands firing in the most economical way will probably save his wages to his employer over the engineer who is indifferent or unscientific about it. Therefore the young engineer should give the subject great attention. First, let us consider firing with coal. All expert engineers advise a “thin” fire. This means that you should have a thin bed of coals, say about four inches thick, all over the grate. There should be no holes or dead places in this, for if there are any, cold air will short-circuit into the fire flues and cool off the boiler. The best way of firing is to spread the coal on with a small hand shovel, a very little at a time, scattering it well over the fire. Another way, recommended by some, is to have a small pile of fresh fuel at the front of the grate, pushing it back over the grate when it is well lighted. To manage this well will require some practice and skill, and for a beginner, we recommend scattering small shovelsful all over the fire. All lump coal should be broken to a uniform size. No piece larger than a man’s fist should be put in a firebox. Seldom use the poker above the fire, for nothing has such a tendency to put out a coal fire as stirring it with a poker above. And when there is a good glow all over the grate below, the poker is not needed below. When the grate becomes covered with dead ashes, they should be cautiously but fully removed, and clinkers must be lifted out with the poker from above, care being exercised to cover up the holes with live coals. Hard coal if used should be dampened before being put on the fire. When the fire is burning a little too briskly, close the draft but do not tamper with the fire itself. Should it become important on a sudden emergency to check the fire at any time quickly, never dash water upon it, but rather throw plenty of fresh fuel upon it. Fresh fuel always lowers the heat at first. If all drafts are closed tight, it will lower the heat considerably for quite a time. In checking a fire, it must be remembered that very sudden cooling will almost surely crack the boiler. If there is danger of an explosion it may be necessary to draw the fire out entirely; but under no circumstances should cold water be thrown on. After drawing the fire close all doors and dampers. FIRING WITH WOOD. Always keep the fire door shut as much as possible, as cold air thus admitted will check the fire and ruin the boiler. Firing with wood is in many ways the exact reverse of firing with coal. The firebox should be filled full of wood at all times. The wood should be thrown in in every direction, in pieces of moderate size, and as it burns away, fresh pieces should be put in at the front so that they will get lighted and ready to burn before being pushed back near the boiler. It often helps a wood fire, too, to stir it with a poker. Wood makes much less ash than coal, and what little accumulates in the grate will not do much harm. Sometimes green wood will not burn because it gets too much cold air. In that case the sticks should be packed as close together as possible, still leaving a place for the air to pass. Also a wood fire, especially one with green wood, should be kept up to a high temperature all the time; for if it is allowed to drop down the wood will suddenly cease to burn at all. FIRING WITH STRAW. In firing with straw it is important to keep the shute full of straw all the time so that no cold air can get in on top of the fire. Don’t push the straw in too fast, either, but keep it moving at a uniform rate, with small forkfulls. Now and then it is well to turn the fork over and run it down into the fire to keep the fire level. Ashes may be allowed to fill up in rear of ash box, but fifteen inches should be kept clear in front to provide draft. The brick arch may be watched from the side opening in the firebox, and should show a continuous stream of white flame coming over it. If too much straw is forced in, that will check the flame. The flame should never be checked. If damp straw gets against the ends of the flues, it should be scraped off with the poker from side door. Clean the tubes well once a day. The draft must always be kept strong enough to produce a white heat, and if this cannot be done otherwise, a smaller nozzle may be used on the exhaust pipe; but this should be avoided when possible, since it causes back pressure on the engine. Never let the front end of the boiler stand on low ground. Engine should be level, or front end high, if it has a firebox locomotive boiler; if a return flue boiler, be careful to keep it always level. In burning straw take particular notice that the spark screen in stack does not get filled up. THE ASH PIT. In burning coal it is exceedingly important that the ashes be kept cleaned out, as the hot cinders falling down on the heap of ashes almost as high as the grate will overheat the grate in a very short time and warp it all out of shape, so ruining it. With wood and straw, on the contrary, an accumulation of ashes will often help and will seldom do any harm, because no very hot cinders can drop down below the grates, and the hottest part of the fire is some distance above the grates. STARTING A FIRE. You must make up your mind that it will take half an hour to an hour or so to get up steam in any boiler that is perfectly cold. The metal expands and shrinks a great deal with the heat and cold, and a sudden application of heat would ruin a boiler in a short time. Hence it is necessary for reasons of engine economy to make changes of temperature, either cooling off or heating up, gradually. First see that there is water in the boiler. Start a brisk fire with pine kindlings, gradually putting on coal or wood, as the case may be, and spreading the fire over the grate so that all parts will be covered with glowing coals. When you have 15 or 20 pounds of steam, start the blower. As has already been described, the blower is a pipe with a nozzle leading from the steam space of the boiler to the smoke stack, and fitted with a globe valve. The force of the steam drives the air out of the stack, causing a vacuum, which is immediately filled by the hot gases from the firebox coming through the boiler tubes. Little is to be gained by using the blower with less than 15 pounds of steam, as the blower has so little strength below that, that it draws off about as much steam as is made and nothing is gained. The blower is seldom needed when the engine is working, as the exhaust steam should be sufficient to keep the fire going briskly. If it is not, you should conclude that something is the matter. There are times, however, when the blower is required even when the engine is going. For example, if you are working with very light load and small use of steam, the exhaust may be insufficient to keep up the fire; and this will be especially true if the fuel is very poor. In such a case, turn on the blower very slightly. But remember that you are wasting steam if you can get along without the blower. Examine the nozzle of the blower now and then to see that it does not become limed up, or turned so as to direct the steam to one side of the stack, where its force would be wasted. Beware, also, of creating too much draft; for too much draft will use up fuel and make little steam. SMOKE. Coal smoke is nothing more or less than unburned carbon. The more smoke you get, the less will be the heat from a given amount of fuel. Great clouds of black smoke from an engine all the time are a very bad sign in an engineer. They show that he does not know how to fire. He has not followed the directions already given, to have a thin, hot fire, with few ashes under his grate. Instead, he throws on great shovelsful of coal at a time, and has the coal up to the firebox door. His fuel is always making smoke, which soon clogs up the smoke flues and lessens the amount of steam he is getting. If he had kept his fire very “thin,” but very hot, throwing on a small hand shovel of coal at a time, seldom poking his fire except to lift out clinkers or clean away dead ashes under the grate, and keeping his ashpit free from ashes, there would be only a little puff of black smoke when the fresh coal went on, and then the smoke would quickly disappear, while the fire flues would burn clean and not get clogged up with soot. It is important, however, to keep the small fire flues especially well cleaned out with a good flue cleaner; for all accumulation of soot prevents the heat from passing through the steel, and so reduces the heating capacity of the boiler. Cleaning the tubes with a steam blower is never advisable, as it forms a paste on the tube that greatly impairs its commodity. SPARKS. With coal there is little danger of fires caused by sparks from the engine. What sparks there are are heavy and dead, and will even fall on a pile of straw without setting it on fire. On a very windy day, however, when you are running your engine very hard, especially if it is of the direct locomotive boiler type, you want to be careful even with coal. With wood it is very different; and likewise with straw. Wood and straw sparks are always dangerous, and an engine should never be run for threshing with wood or straw without using a spark-arrester. It sometimes happens that when coal is used it will give out, and you will be asked to finish your job with wood. In such a case, it is the duty of an engineer to state fully and frankly the danger of firing with wood without a spark arrester, and he should go on only when ordered to do so by the proprietor, after he has been fully warned. In that case all responsibility is shifted from the engineer to the owner. THE FUSIBLE PLUG. The careful engineer will never have occasion to do anything to the fusible plug except to clean the scale off from the top of it on the inside of the boiler once a week, and put in a fresh plug once a month. It is put in merely as a precaution to provide for carelessness. The engineer who allows the fusible plug to melt out is by that very fact marked as a careless man, and ought to find it so much the harder to get a job. As has already been explained, the fusible plug is a plug filled in the middle with some metal that will melt at a comparatively low temperature. So long as it is covered with water, no amount of heat will melt it, since the water conducts the heat away from the metal and never allows it to rise above a certain temperature. When the plug is no longer covered with water, however,--in short, when the water has fallen below the danger line in the boiler--the metal in the plug will fuse, or melt, and make an opening through which the steam will blow into the firebox and put out the fire. However, if the top of the fusible plug has been allowed to become thickly coated with scale, this safety precaution may not work and the boiler may explode. In any case the fusible plug is not to be depended on. At the same time a good engineer will take every precaution, and one of these is to keep the top of the plug well cleaned. Also he will have an extra plug all ready and filled with composition metal, to put in should the plug in the boiler melt out. Then he will refill the old plug as soon as possible. This may be done by putting a little moist clay in one end to prevent the hot metal from running through, and then pouring into the other end of the plug as much melted metal as it will hold. When cold, tamp down solidly. LEAKY FLUES. One common cause of leaky flues is leaving the fire door open so that currents of cold air will rush in on the heated flues and cause them, or some other parts of the boiler, to contract too suddenly. The best boiler made may be ruined in time by allowing cold currents of air to strike the heated interior. Once or twice will not do it; but continually leaving the fire door open will certainly work mischief in the end. Of course, if flues in a new boiler leak, it is the fault of the boiler maker. The tubes were not large enough to fill the holes in the tube sheets properly. But if a boiler runs for a season or so and then the flues begin to leak, the chances are that it is due to the carelessness of the engineer. It may be he has been making his fires too hot; it may be leaving the firebox door open; it may be running the boiler at too high pressure; it may be blowing out the boiler when it is too hot; or blowing out the boiler when there is still some fire in the firebox; it may be due to lime encrusted on the inside of the tube sheets, causing them to overheat. Flues may also be made to leak by pumping cold water into the boiler when the water inside is too low; or pouring cold water into a hot boiler will do it. Some engineers blow out their boilers to clean them, and then being in a hurry to get to work, refill them while the metal is hot. The flues cannot stand this, since they are thinner than the shell of the boiler and cool much more quickly; hence they will contract much faster than the rest of the boiler and something has to come loose. Once a flue starts to leaking, it is not likely to stop till it has been repaired; and one leaky flue will make others leak. Now what shall you do with a leaky flue? To repair a leaky flue you should have a flue expander and a calking tool, with a light hammer. If you are small enough you will creep in at the firebox door with a candle in your hand. First, clean off the ends of the flues and flue sheet with some cotton waste. Then force the expander into the leaky flue, bringing the shoulder well up against the end of the flue. Then drive in the tapering pin. Be very careful not to drive it in too far, for if you expand the flue too much, you will strain the flue sheet and cause other flues to leak. You must use your judgment and proceed cautiously. It is better to make two or three trials than to spoil your boiler by bad work. The roller expander is preferable to the Prosser in the hands of a novice. The tube should be expanded only enough to stop the leak. Farther expanding will only do injury. When you think the flue has been expanded enough, hit the pin a side blow to loosen it. Then turn the expander a quarter round, and drive in the pin again. Loosen up and continue till you have turned the expander entirely around. Finally remove the expander, and use the calking tool to bead the end. It is best, however, to expand all leaky flues before doing any beading. The beading is done by placing the guide or gauge inside the flue, and then pounding the ends of the flue down against the flue sheet by light blows. Be very careful not to bruise the flue sheet or flues, and use no heavy blows, nor even a heavy hammer. Go slowly and carefully around the end of each flue; and if you have done your work thoroughly and carefully the flues will be all right. But you should test your boiler before steaming up, to make sure that all the leaks are stopped, especially if there have been bad ones. There are various ways to testing a boiler. If waterworks are handy, connect the boiler with a hydrant and after filling the boiler, let it receive the hydrant pressure. Then examine the calked flues carefully, and if you see any seeping of water, use your beader lightly till the water stops. In case no waterworks with good pressure are at hand, you can use a hydraulic pump or a good force pump. The amount of pressure required in testing a boiler should be that at which the safety valve is set to blow off, say 110 to 130 lbs. This will be sufficient. If you are in the field with no hydrant or force pump handy, you may test your boiler in this way: Take off the safety valve and fill the boiler full of water through the safety valve opening. Then screw the safety back in its place. You should be sure that every bit of space in the boiler is filled entirely full of water, with all openings tightly closed. Then get back in the boiler and have a bundle of straw burned under the firebox, or under the waist of the boiler, so that at some point the water will be slightly heated. This will cause pressure. If your safety valve is in perfect order, you will know as soon as water begins to escape at the safety valve whether your flues are calked tight enough or not. The water is heated only a few degrees, and the pressure is cold water pressure. In very cold weather this method cannot be used, however, as water has no expansive force within five degrees of freezing. The above methods are not intended for testing the safety of a boiler, but only for testing for leaky flues. If you wish to have your boiler tested, it is better to get an expert to do it. CHAPTER V. HOW TO MANAGE A TRACTION ENGINE. A traction engine is usually the simplest kind of an engine made. If it were not, it would require a highly expert engineer to run it, and this would be too costly for a farmer or thresherman contractor. Therefore the builders of traction engines make them of the fewest possible parts, and in the most durable and simple style. Still, even the simplest engine requires a certain amount of brains to manage it properly, especially if you are to get the maximum of work out of it at the lowest cost. If the engine is in perfect order, about all you have to do is to see that all bearings are properly lubricated, and that the automatic oiler is in good working condition. But as soon as an engine has been used for a certain time, there will be wear, which will appear first in the journals, boxes and valve, and it is the first duty of a good engineer to adjust these. To adjust them accurately requires skill; and it is the possession of that skill that goes to make a real engineer. Your first attention will probably be required for the cross-head and crank boxes or brasses. The crank box and pin will probably wear first; but both the cross-head and crank boxes are so nearly alike that what is said of one will apply to the other. You will find the wrist box in two parts. In a new engine these parts do not quite meet. There is perhaps an eighth of an inch waste space between them. They are brought up to the box in most farm engines by a wedge-shaped key. This should be driven down a little at a time as the boxes wear, so as to keep them snug up to the pin, though not too tight. You continue to drive in the key and tighten up the boxes as they wear until the two halves come tight together. Then you can no longer accomplish anything in this way. When the brasses have worn so that they can be forced no closer together, they must be taken off and the ends of them filed where they come together. File off a sixteenth of an inch from each end. Do it with care, and be sure you get the ends perfectly even. When you have done this you will have another eighth of an inch to allow for wear. Now, by reflection you will see that as the wrist box wears, and the wedge-shaped key is driven in, the pitman (or piston arm) is lengthened to the amount that the half of the box farthest from the piston has worn away. When the brasses meet, this will amount to one-sixteenth of an inch. Now if you file the ends off and the boxes wear so as to come together once more, the pitman will have been shortened one-eighth of an inch; and pretty soon the clearance of the piston in the cylinder will have been offset, and the engine will begin to pound. In any case, the clearance at one end of the cylinder will be one-sixteenth or one-eighth of an inch less, and in the other end one-sixteenth or one-eighth of an inch more. When this is the case you will find that the engine is not working well. To correct this, when you file the brasses either of the cross-head box or the crank box you must put in some filling back of the brass farthest from the piston, sufficient to equalize the wear that has taken place, that is, one-sixteenth of an inch each time you have to file off a sixteenth of an inch. This filling may be some flat pieces of tin or sheet copper, commonly called shims, and the process is called shimming. As to the front half of the box, no shims are required, since the tapering key brings that box up to its proper place. Great care must be exercised when driving in the tapering key or wedge to tighten up the boxes, not to drive it in too hard. Many engineers think this is a sure remedy for “knocking” in an engine, and every time they hear a knock they drive in the crank box key. Often the knock is from some other source, such as from a loose fly wheel, or the like. Your ear is likely to deceive you; for a knock from any part of an engine is likely to sound as if it came from the crank box. If you insist on driving in the key too hard and too often, you will ruin your engine. In tightening up a key, first loosen the set screw that holds the key; then drive down the key till you think it is tight; then drive it back again, and this time force it down with your fist as far as you can. By using your fist in this way after you have once driven the pin in tight and loosened it again you may be pretty certain you are not going to get it so tight it will cause the box to heat. WHAT CAUSES AN ENGINE TO KNOCK. The most common sign that something is loose about an engine is “knocking,” as it is called. If any box wears a little loose, or any wheel or the like gets a trifle loose, the engine will begin to knock. When an engine begins to knock or run hard, it is the duty of the engineer to locate the knock definitely. He must not guess at it. When he has studied the problem out carefully, and knows where the knock is, then he may proceed to remedy it. Never adjust more than one part at a time. As we have said, a knock is usually due to looseness somewhere. The journals of the main shaft may be loose and cause knocking. They are held in place by set bolts and jam nuts, and are tightened by simply screwing up the nuts. But a small turn of a nut may make the box so tight it will begin to heat at once. Great care should be taken in tightening up such a box to be sure not to get it too tight. Once a box begins to cut, it should be taken out and thoroughly cleaned. Knocking may be due to a loose eccentric yoke. There is packing between the two halves of the yoke, and to tighten up you must take out a thin layer of this packing. But be careful not to take out too much, or the eccentric will stick and begin to slip. Another cause of knocking is the piston rod loose in the cross-head. If the piston rod is keyed to the cross-head it is less liable to get loose than if it were fastened by a nut; but if the key continues to get loose, it will be best to replace it with a new one. Unless the piston rod is kept tight in the cross-head, there is liability of a bad crack. A small strain will bring the piston out of the cross-head entirely, when the chances are you will knock out one or both cylinder-heads. If a nut is used, there will be the same danger if it comes off. It should therefore be carefully watched. The best way is to train the ear to catch any usual sound, when loosening of the key or nut will be detected at once. Another source of knocking is looseness of the cross-head in the guides. Provision is usually made for taking up the wear; but if there is not, you can take off the guides and file them or have them planed off. You should take care to see that they are kept even, so that they will wear smooth with the crosshead shoes. If the fly-wheel is in the least loose it will also cause knocking, and it will puzzle you not a little to locate it. It may appear to be tight; but if the key is the least bit too narrow for the groove in the shaft, it will cause an engine to bump horribly, very much as too much “lead” will. LEAD. We have already explained what “lead” is. It is opening of the port at either end of the steam cylinder allowed by the valve when the engine is on a dead centre. To find out what the lead is, the cover of the steam chest must be taken off, and the engine placed at each dead centre in succession. If the lead is greater at one end than it is at the other, the valve must be adjusted to equalize it. As a rule the engine is adjusted with a suitable amount of lead if it is equalized. The correct amount of lead varies with the engine and with the port opening. If the port opening is long and narrow, the lead should obviously be less than if the port is short and wide. If the lead is insufficient, there will not be enough steam let into the cylinder for cushion, and the engine will knock. If there is too much lead the speed of the engine will be lessened, and it will not do the work it ought. To adjust the lead _de novo_ is by no means an easy task. HOW TO SET A SIMPLE VALVE. In order to set a valve the engine must be brought to a dead centre. This cannot be done accurately by the eye. An old engineer[5] gives the following directions for finding the dead centre accurately. Says he: “First provide yourself with a ‘tram.’ This is a rod of one-fourth inch iron about eighteen inches long, with two inches at one end bent over to a sharp angle. Sharpen both ends to a point. Fasten a block of hard wood somewhere near the face of the fly-wheel, so that when the straight end of your tram is placed at a definite point in the block, the hooked end will reach the crown of the fly-wheel. The block must be held firmly in its place, and the tram must always touch it at exactly the same point. Footnote 5: J. H. Maggard. “You are now ready to set about finding the dead centre. In doing this, remember to turn the fly-wheel always in the same direction. “Bring the engine over till it nearly reaches one of the dead centres, but not quite. Make a distinct mark across the cross-head and guides. Also go around to the flywheel, and placing the straight end of the tram at the selected point on the block of wood, make a mark across the crown or centre of face of the fly-wheel. Now turn your engine past the centre, and on to a point at which the mark on the cross head will once more exactly correspond with the line on the guides, making a single straight line. Once more place the tram as before and make another mark across the crown of the fly-wheel. By use of dividers, find the exact centre between the two marks made on the fly-wheel, and mark this point distinctly with a centre punch. Now bring the fly-wheel to the point where the tram, set with its straight end at the required point on the block of wood, will touch this point with the hooked end, and you will have one of the dead centres. “Turn the engine over and proceed in the same way to find the other dead centre.” Now, setting the engine on one of the dead centres, remove the cover of the steam chest and proceed to set your valve. Assuming that the engine maker gave the valve the proper amount of lead in the first place, you can proceed on the theory that it is merely necessary to equalize the lead at both ends. Assume some convenient lead, as one-sixteenth of an inch, and set the valve to that. Then turn the engine over and see if the lead at the other end is the same. If it is the same, you have set the valve correctly. If it is less at the other end, you may conclude that the lead at both ends should be less than one-sixteenth of an inch, and must proceed to equalize it. This you can do by fitting into the open space a little wedge of wood, changing the valve a little until the wedge goes in to just the same distance at each end. Then you may know that the lead at one end is the same as at the other end. You can mark the wedge for forcing it against the metal, or mark it against the seat of the valve with a pencil. The valve is set by loosening the set screws that hold the eccentric on the shaft. When these are loosened up the valve may be moved freely. When it is correctly set the screws should be tightened, and the relative position of the eccentric on the shaft may be permanently marked by setting a cold chisel so that it will cut into the shaft and the eccentric at the same time and giving it a smart blow with the hammer, so as to make a mark on both the eccentric and the shaft. Should your eccentric slip at any time in the future, you can set your valve by simply bringing the mark on the eccentric so that it will correspond with the mark on the shaft. Many engines have such a mark made when built, to facilitate setting a valve should the eccentric become loose. These directions apply only to setting the valve of a single eccentric engine. HOW TO SET A VALVE ON A DOUBLE ECCENTRIC ENGINE. In setting a valve on a reversible or double eccentric engine, the link may cause confusion, and you may be trying to set the valve to run one way when the engine is set to run the other. The valve on such an engine is exactly the same as on a single eccentric engine. Set the reverse lever for the engine to go forward. Then set the valve exactly as with a single eccentric engine. When you have done so, tighten the eccentric screws so that they will hold temporarily, and set the reverse lever for the engine to go backward. Then put the engine on dead centres and see if the valve is all right at both ends. If it is, you may assume that it is correctly set, and tighten eccentric screws, marking both eccentrics as before. As we have said, most engines are marked in the factory, so that it is not a difficult matter to set the valves, it being necessary only to bring the eccentric around so that the mark on it will correspond with the mark on the shaft. You can easily tell whether the lead is the same at both ends by listening to the exhaust. If it is longer at one end than the other, the valve is not properly set. SLIPPING OF THE ECCENTRIC OR VALVE. If the eccentric slips the least bit it may cause the engine to stop, or to act very queerly. Therefore the marks on the shaft and on the eccentric should be watched closely, and of course all grease and dirt should be kept wiped off, so that they can be seen easily. Then the jam nuts should be tightened up a little from time to time. If the engine seems to act strangely, and yet the eccentrics are all right, look at the valve in the steam chest. If the valve stem has worked loose from the valve, trouble will be caused. It may be held in place by a nut, and the nut may work off; or the valve may be held by a clamp and pin, and the pin may work loose. Either will cause loss of motion, and perhaps a sudden stopping of the engine. USE OF THE CYLINDER STEAM COCKS. It is a comparatively simple matter to test a steam cylinder by use of the cylinder cocks. To do this, open both cocks, place the engine on the forward center, and turn on a little steam. If the steam blows out at the forward cock, we may judge that our lead is all right. Now turn the engine to the back center and let on the steam. It should blow out the same at the back cock. A little training of the ear will show whether the escape of steam is the same at both ends. Then reverse the engine, set it on each center successfully, and notice whether the steam blows out from one cock at a time and in the same degree of force. If the steam blows out of both cocks at the same time, or out of one cock on one center, but not out of the other cock on its corresponding center, we may know something is wrong. The valve does not work properly. We will first look at the eccentrics and see that they are all right. If they are, we must open the steam chest, first turning off all steam. Probably we shall find that the valve is loose on the valve rod, if our trouble was that the steam blew out of the cock but did not out of the other when the engine was on the opposite center. If our trouble was that steam blew out of both cocks at the same time, we may conclude either that the cylinder rings leak or else the valve has cut its seat. It will be a little difficult to tell which at first sight. In any case it is a bad thing, for it means loss of power and waste of steam and fuel. To tell just where the trouble is you must take off the cylinder head, after setting the engine on the forward center. Let in a little steam from the throttle. If it blows through around the rings, the trouble is with them; but if it blows through the valve port, the trouble is with the valve and valve seat. If the rings leak you must get a new set if they are of the self-adjusting type. But if they are of the spring or adjusting type you can set them out yourself; but few engines now use the latter kind of rings, so a new pair will probably be required. If the trouble is in the valve and valve seat, you should take the valve out and have the seat planed down, and the valve fitted to the seat. This should always be done by a skilled mechanic fully equipped for such work, as a novice is almost sure to make bad work of it. The valve seat and valve must be scraped down by the use of a flat piece of very hard steel, an eighth of an inch thick and about 3 by 4 inches in size. The scraping edge must be absolutely straight. It will be a slow and tedious process, and a little too much scraping on one side or the other will prevent a perfect fit. Both valve and valve seat must be scraped equally. Novices sometimes try to reseat a valve by the use of emery. This is very dangerous and is sure to ruin the valve, as it works into the pores of the iron and causes cutting. LUBRICATION. A knowledge of the difference between good oil and poor oil, and of how to use oil and grease, is a prime essential for an engineer. First let us give a little attention to the theory of lubrication. The oil or grease should form a lining between the journal and its pin or shaft. It is in the nature of a slight and frictionless cushion at all points where the two pieces of metal meet. Now if oil is to keep its place between the bearing and the shaft or pin it must stick tight to both pieces of metal, and the tighter the better. If the oil is light the forces at work on the bearings will force the oil away and bring the metals together. As soon as they come together they begin to wear on each other, and sometimes the wear is very rapid. This is called “cutting.” If a little sand or grit gets into the bearing, that will help the cutting wonderfully, and more especially if there is no grease there. For instance, gasoline and kerosene are oils, but they are so light they will not stick to a journal, and so are valueless for lubricating. Good lubricating oil will cost a little more than cheap oil which has been mixed with worthless oils to increase its bulk without increasing its cost. The higher priced oil will really cost less in the end, because there is a larger percentage of it which will do service. A good engineer will have it in his contract that he is to be furnished with good oil. Now an engine requires two different kinds of oil, one for the bearings, such as the crank, pin, the cross-head and journals, and quite a different kind for lubricating the steam cylinder. It is extremely important that the steam cylinder should be well lubricated; and this cannot be done direct. The oil must be carried into the valve and cylinder with steam. The heat of the steam, moreover, ranging from about 320 degrees Fahr. for 90 lbs. pressure to 350 degrees for 125 lbs. of pressure, will quickly destroy the efficacy of a poor oil, and a good cylinder oil must be one that will stick to the cylinder and valve seat under this high temperature. It must have staying qualities. The link reverse is one of the best for its purpose; but it requires a good quality of oil on the valve for it to work well. If the valve gets a little dry, or the poor oil used does not serve its purpose properly, the link will begin to jump and pound. This is a reason why makers are substituting other kinds of reverse gear in many ways not as good, but not open to this objection. If a link reverse begins to pound when you are using good oil, and the oiler is working properly, you may be sure something is the matter with the valve or the gear. A good engineer will train his ear so that he will detect by simply listening at the cylinder whether everything is working exactly as it ought. For example, the exhaust at each end of the cylinder, which you can hear distinctly, should be the same and equal. If the exhaust at one end is less than it is at the other, you may know that one end of the cylinder is doing more work than the other. And also any little looseness or lack of oil will signify itself by the peculiar sound it will cause. While the cylinder requires cylinder oil, the crank, cross-head and journals require engine oil, or hard grease. The use of hard grease is rapidly increasing, and it is highly to be recommended. With a good automatic spring grease cup hard grease will be far less likely to let the bearings heat than common oil will. At the same time it will be much easier to keep an engine clean if hard grease is used. An old engineer[6] gives the following directions for fitting a grease cup on a box not previously arranged for one: “Remove the journal, take a gouge and cut a clean groove across the box, starting at one corner, about one-eighth of an inch from the point of the box, and cut diagonally across, coming out at the opposite corner on the other end of the box. Then start at the opposite corner and run through as before, crossing the first groove in the center of the box. Groove both halves of the box the same, being careful not to cut out at either end, as this will allow the grease to escape from the box and cause unnecessary waste. The shimming or packing in the box should be cut so as to touch the journal at both ends of the box, but not in the center or between these two points. So when the top box is brought down tight this will form another reservoir for the grease. If the box is not tapped directly in the center for the cup, it will be necessary to cut another groove from where it is tapped into the grooves already made. A box prepared in this way and carefully polished inside, will require little attention if you use good grease.” Footnote 6: J. H. Maggard. A HOT BOX. When a box heats in the least degree, it is a sign that for lack of oil or for some other reason the metals are wearing together. The first thing to do, of course, is to see that the box is supplied with plenty of good oil or grease. If this does not cause the box to cool off, take it apart and clean it thoroughly. Then coat the journal with white lead mixed with good oil. Great care should be exercised to keep all dirt or grit out of your can of lead and away from the bearing. Replace the oil or grease cup, and the box will soon cool down. THE FRICTION CLUTCH. Nearly all traction engines are now provided with the friction clutch for engaging the engine with the propelling gear. The clutch is usually provided with wooden shoes, which are adjustable as they wear; and the clutch is thrown on by a lever, conveniently placed. [Illustration: A. W. STEVENS CO. FRICTION CLUTCH.] Before running an engine, you must make sure that the clutch shoes are properly adjusted. Great care must be taken to be sure that both shoes will come in contact with the friction wheel at the same instant; for if one shoe touches the wheel before the other the clutch will probably slip. The shoes should be so set as to make it a trifle difficult to draw the lever clear back. To regulate the shoes on the Rumely engine, for example, first throw the friction in. The nut on the top of the toggle connecting the sleeve of the friction with the shoe must then be loosened, and the nut below the shoe tightened up, forcing the shoe toward the wheel. Both shoes should be carefully adjusted so that they will engage the band wheel equally and at exactly the same time. To use the friction clutch, first start the engine, throwing the throttle gradually wide open. When the engine is running at its usual speed, slowly bring up the clutch until the gearing is fully engaged, letting the engine start slowly and smoothly, without any jar. Traction engines having the friction clutch are also provided with a pin for securing a rigid connection, to be used in cases of necessity, as when the clutch gets broken or something about it gives out, or you have difficulty in making it hold when climbing hills. This pin is a simple round or square pin that can be placed through a hole in one of the spokes of the band wheel until it comes into a similar opening in the friction wheel. When the pin is taken out, so as to disconnect the wheels, it must be entirely removed, not left sticking in the hole, as it is liable to catch in some other part of the machinery. [Illustration: AULTMAN & TAYLOR FRICTION CLUTCH.] MISCELLANEOUS SUGGESTIONS. Be careful not to open the throttle valve too quickly, or you may throw off the driving belt. You may also stir up the water and cause it to pass over with the steam, starting what is called “priming.” Always open your cylinder cocks when you stop, to make sure all water has been drained out of the cylinder; and see that they are open when you start, of course closing them as soon as the steam is let in. When you pull out the ashes always have a pail of water ready, for you may start a fire that will do no end of damage. If the water in your boiler gets low and you are waiting for the tank to come up, don’t think you “can keep on a little longer,” but stop your engine at once. It is better to lose a little time than run the risk of an explosion that will ruin your reputation as an engineer and cause your employer a heavy expense. Never start the pump when the water in the boiler is low. Be sure the exhaust nozzle does not get limed up, and be sure the pipe where the water enters the boiler from the heater is not limed up, or you may split a heater pipe or knock out a check valve. Never leave your engine in cold weather without draining off all the water; and always cover up your engine when you leave it. Never disconnect the engine with a leaky throttle. Keep the steam pressure steady, not varying more than 10 to 15 lbs. If called on to run an old boiler, have it thoroughly tested before you touch it. Always close your damper before pulling through a stack yard. Examine every bridge before you pull on to it. Do not stop going down a steep grade. CHAPTER VI. HANDLING A TRACTION ENGINE ON THE ROAD. It is something of a trick to handle a traction engine on the road. The novice is almost certain to run it into a ditch the first thing, or get stuck on a hill, or in a sand patch or a mudhole. Some attention must therefore be paid to handling a traction engine on the road. In the first place, never pull the throttle open with a jerk, nor put down the reverse lever with a snap. Handle your engine deliberately and thoughtfully, knowing beforehand just what you wish to do and how you will do it. A traction engine is much like an ox; try to goad it on too fast and it will stop and turn around on you. It does its best work when moving slowly and steadily, and seldom is anything gained by rushing. The first thing for an engineer to learn is to handle his throttle. When an engine is doing work the throttle should be wide open; but on the road, or in turning, backing, etc., the engineer’s hand must be on the throttle all the time and he must exercise a nice judgment as to just how much steam the engine will need to do a certain amount of work. This the novice will find out best by opening the throttle slowly, taking all the time he needs, and never allowing any one to hurry him. As an engineer learns the throttle, he gradually comes to have confidence in it. As it were, he feels the pulse of the animal and never makes a mistake. Such an engineer always has power to spare, and never wastes any power. He finds that a little is often much better than too much. The next thing to learn is the steering wheel. It has tricks of its own, which one must learn by practice. Most young engineers turn the wheel altogether too much. If you let your engine run slowly you will have time to turn the wheel slowly, and accomplish just what you want to do. If you hurry you will probably have to do your work all over again, and so lose much more time in the end than if you didn’t hurry. Always keep your eyes on the front wheels of the engine, and do not turn around to see how your load is coming on. Your load will take care of itself if you manage the front wheels all right, for they determine where you are to go. In making a hard turn, especially, go slow. Then you will run no chance of losing control of your engine, and you can see that neither you nor your load gets into a ditch. GETTING INTO A HOLE. You are sure sooner or later to get into a hole in the road, for a traction engine is so heavy it is sure to find any soft spot in the road there may be. As to getting out of a hole, observe in the first place that you must use your best judgment. First, never let the drive wheels turn round without doing any work. The more they spin round without helping you, the worse it will be for you. Your first thought must be to give the drive wheels something they can climb on, something they can stick to. A heavy chain is perhaps the very best thing you can put under them. But usually on the road you have no chain handy. In that case, you must do what you can. Old hay or straw will help you; and so will old rails or any old timber. Spend your time trying to give your wheels something to hold to, rather than trying to pull out. When the wheels are all right, the engine will go on its way without any trouble whatever. And do not half do your work of fixing the wheels before you try to start. See that both wheels are secure before you put on a pound of steam. Make sure of this the first time you try, and you will save time in the end. If you fix one wheel and don’t fix the other, you will probably spoil the first wheel by starting before the other is ready. Should you be where your engine will not turn, then you are stuck indeed. You must lighten your load or dig a way out. BAD BRIDGES. A traction engine is so heavy that the greatest care must be exercised in crossing bridges. If a bridge floor is worn, if you see rotten planks in it, or liability of holes, don’t pull on to that bridge without taking precautions. The best precaution is to carry with you a couple of planks sixteen feet long, three inches thick in the middle, tapering to two inches at the ends; also a couple of planks eight feet long and two inches thick, the latter for culverts and to help out on long bridges. Before pulling on to a bad looking bridge, lay down your planks, one for each pair of wheels of the engine to run on. Be exceedingly careful not to let the engine drop off the edge of these planks on the way over, or pass over the ends on to the floor of the bridge. If one pair of planks is too short, use your second pair. Another precaution which it is wise to take is to carry fifty feet of good, stout hemp rope, and when you come to a shaky bridge, attach your separator to the engine by this rope at full length, so that the engine will have crossed the bridge before the weight of the separator comes upon it. Cross a bad bridge very slowly. Nothing will be gained by hurrying. There should especially be no sudden jerks or starts. SAND PATCHES. A sandy road is an exceedingly hard road to pull a load over. In the first place, don’t hurry over sand. If you do you are liable to break the footing of the wheels, and then you are gone. In the second place, keep your engine as steady and straight as possible, so that both wheels will always have an equal and even bearing. They are less liable to slip if you do. It is useless to try to “wiggle” over a sand patch. Slow, steady, and even is the rule. If your wheels slip in sand, a bundle of straw or hay, especially old hay, will be about the best thing to give them a footing. HILLS. In climbing hills take the same advice we have given you all along: Go slow. Nothing is gained by rushing at a hill with a steam engine. Such an engine works best when its force is applied steadily and evenly, a little at a time. If you have a friction clutch, as you probably will have, you should be sure it is in good working order before you attempt to climb hills. It should be adjusted to a nicety, as we have already explained. When you come to a bad hill it would probably be well to put in the tight gear pin; or use it altogether in a hilly country. When the friction clutch first came into use, salesmen and others used to make the following recommendation (a recommendation which we will say right here is bad). They said, when you come to an obstacle in the road that you can’t very well get your engine over, throw off your friction clutch from the road wheels, let your engine get under good headway running free, and then suddenly put on the friction clutch and jerk yourself over the obstacle. Now this is no doubt one way to get over an obstacle; but no good engineer would take his chances of spoiling his engine by doing any such thing with it. Some part of it would be badly strained by such a procedure; and if this were done regularly all through a season, an engine would be worth very little at the end of the season. CHAPTER VII. POINTS FOR THE YOUNG ENGINEER. QUESTIONS AND ANSWERS. THE BOILER. Q. How should water be fed to a boiler? A. In a steady stream, by use of a pump or injector working continuously and supplying just the amount of water required. By this means the water in the boiler is maintained at a uniform level, and produces steam most evenly and perfectly. Q. Why should pure water be used in a boiler? A. Because impure water, or hard water, forms scales on the boiler flues and plates, and these scales act as non-conductors of heat. Thus the heat of the furnace is not able to pass easily through the boiler flues and plates to the water, and your boiler becomes what is called “a hard steamer.” Q. What must be done to prevent the formation of scale? A. First, use some compound that will either prevent scale from forming, or will precipitate the scale forming substance as a soft powder that can easily be washed off. Sal soda dissolved in the feed water is recommended, but great care should be exercised in the use of sal soda not to use too much at a time, as it may cause a boiler to foam. Besides using a compound, clean your boiler often and regularly with a hand hose and a force pump, and soak it out as often as possible by using rain water for a day or two, especially before cleaning. Rain water will soften and bring down the hard scale far better than any compound. Q. How often should you clean your boiler? A. As often as it needs it, which will depend upon the work you do and the condition of the water. Once a week is usually often enough if the boiler is blown down a little every day. If your water is fairly good, once a month will be often enough. A boiler should be blown off about one gauge at a time two or three times a day with the blow-off if the water is muddy. Q. How long should the surface blow-off be left open? A. Only for a few seconds, and seldom longer than a minute. The surface blow-off carries off the scum that forms on the water, and other impurities that rise with the scum. Q. How do you clean a boiler by blowing off? A. When the pressure has been allowed to run down open the blow-off valve at the bottom of the boiler and let the water blow out less than a minute, till the water drops out of sight in the water gauges, or about two and one-half inches. Blowing off more is only a waste of heat and fuel. Q. What harm will be done by blowing off a boiler under a high pressure of steam? A. The heat in the boiler while there is such a pressure will be so great that it will bake the scale on the inside of the boiler, and it will be very difficult to remove it afterward. After a boiler has been blown off the scale should be for the most part soft, so that it can be washed out by a hose and force pump. Q. Why should a hot boiler never be filled with cold water? A. Because the cold water will cause the boiler to contract more in some places than in others, and so suddenly that the whole will be badly strained. Leaky flues are made in this way, and the life of a boiler greatly shortened. As a rule a boiler should be filled only when the metal and the water put into it are about at the same temperature. Q. After a boiler has been cleaned, how should the manhole and manhole plates be replaced? A. They are held in position by a bolt passing through a yoke that straddles the hole; but to be steam and water tight they must have packing all around the junction of the plate with the boiler. The best packing is sheet rubber cut in the form of a ring just the right size for the bearing surface. Hemp or cotton packing are also used, but they should be free from all lumps and soaked in oil. Do not use any more than is absolutely needed. Be careful, also, to see that the bearings of the plate and boiler are clean and smooth, with all the old packing scraped off. Candle wick saturated with red lead is next best to rubber as packing. Q. What are the chief duties of an engineer in care of a boiler? A. First, to watch all gauges, fittings, and working parts, to see that they are in order; try the gauge cocks to make sure the water is at the right height; try the safety valve from time to time to be sure it is working; see that there are no leaks, that there is no rusting or wearing of parts, or to replace parts when they do begin to show wear; to examine the check valve frequently to make sure no water can escape through it from the boiler; take precautions against scale and stoppage of pipes by scale; and keep the fire going uniformly, cleanly, and in an economical fashion. Q. What should you do if the glass water gauge breaks? A. Turn off the gauge cocks above and below, the lower one first so that the hot water will not burn you. You may put in a new glass and turn on gauge cocks at once. Turn on the lower or water cock first, then the upper or steam cock. You may go on without the glass gauge, however, using the gauge cocks or try cocks every few minutes to make sure the water is at the right height, neither too high nor too low. Q. Why is it necessary to use the gauge cocks when the glass gauge is all right? A. First, because you cannot otherwise be sure that the glass gauge is all right; and, secondly, because if you do not use them frequently they are likely to become scaled up so that you cannot use them in case of accident to the glass gauge. Q. If a gauge cock gets leaky, what should be done? A. Nothing until the boiler has cooled down. Then if the leak is in the seat, take it out and grind and refit it; if the leak is where the cock is screwed into the boiler, tighten it up another turn and see if that remedies the difficulty. If it does not you will probably have to get a new gauge cock. Q. Why not screw up a gauge cock while there is a pressure of steam on? A. The cock might blow out and cause serious injury to yourself or some one else. Make it a rule never to fool with any boiler fittings while there is a pressure of steam on the boiler. It is exceedingly dangerous. Sometimes a gauge cock gets broken off accidentally while the boiler is in use. If such an accident happens, bank the fire by closing the draft and covering the fire with fresh fuel or ashes. Stop the engine and let the water blow out of the hole till only steam appears; then try to plug the opening with a long whitewood or poplar, or even a pine stick (six or eight feet long), one end of which you have whittled down to about the size of the hole. When the steam has been stopped the stick may be cut off close to the boiler and the plug driven in tight. If necessary you may continue to use the boiler in this condition until a new cock can be put in. Q. What should you do when a gauge cock is stopped up? A. Let the steam pressure go down, and then take off the front part and run a small wire into the passage, working the wire back and forth until all scale and sediment has been removed. Q. What should you do when the steam gauge gets out of order. A. If the steam gauge does not work correctly, or you suspect it does not, you may test it by running the steam up until it blows off at the safety valve. If the steam gauge does not indicate the pressure at which the safety valve is set to pop off, and you have reason to suppose the safety valve is all right, you may conclude that there is something the matter with the steam gauge. In that case either put in a new one, or, if you have no extra steam gauge on hand, shut down your boiler and engine till you can get your steam gauge repaired. Sometimes this can be done simply by adjusting the pointer, which may have got loose, and you can test it by attaching it to another boiler which has a steam gauge that is all right and by which you can check up yours. It is VERY DANGEROUS to run your boiler without a steam gauge, depending on the safety valve. Never allow the slightest variation in correctness of the steam gauge without repairing it at once. It will nearly always be cheaper in these days to put in a new gauge rather than try to repair the old one. Q. What should you do if the pump fails to work? A. Use the injector. Q. What should you do if there is no injector? A. Stop the engine at once and bank the fire with damp ashes, especially noting that the water does not fall below the bottom of the glass gauge. Then examine the pump. First see if the plunger leaks air; if it is all right, examine the check valves, using the little drain cock as previously explained to test the upper ones, for the valves may have become worn and will leak; third, if the check valves are all right, examine the supply pipe, looking at the strainer, observing whether suction takes place when the pump is worked, etc. There may be a leak in the suction hose somewhere during its course where air can get in, or it may become weak and collapse under the force of the atmosphere, or the lining of the suction pipe may have become torn or loose. The slightest leak in the suction pipe will spoil the working of the pump. Old tubing should never be used, as it is sure to give trouble. Finally, examine the delivery pipe. Close the cock or valve next the boiler, and examine the boiler check valve; notice whether the pipe is getting limed up. If necessary, disconnect the pipe and clean it out with a stiff wire. If everything is all right up to this point, you must let the boiler cool off, blow out the water, disconnect the pipe between the check and the boiler, and thoroughly clean the delivery pipe into the boiler. Stoppage of the delivery pipe is due to deposits of lime from the heating of the water in the heater. Stoppage from this source will be gradual, and you will find less and less water going into your boiler from your pump until none flows at all. From this you may guess the trouble. Q. How may the communication with the water gauge always be kept free from lime? A. By blowing it off through the drain cock at the bottom. First close the upper cock and blow off for a few seconds, the water passing through the lower cock; then close the lower cock and open the upper one, allowing the steam to blow through this and the drain cock for a few seconds. If you do this every day or oftener you will have no trouble. Q. Should the water get low for any reason, what should be done? A. Close all dampers tight so as to prevent all draft, and bank the fire with fresh fuel or with ashes (damp ashes are the best if danger is great). Then let the boiler cool down before putting in fresh water. Banking the fire is better than drawing or dumping it, as either of these make the heat greater for a moment or two, and that additional heat might cause an explosion. Dashing cold water upon the fire is also very dangerous and in every way unwise. Again, do not open the safety valve, for that also, by relieving some of the pressure on the superheated water, might cause it to burst suddenly into steam and so cause an explosion. Q. Under such circumstances, would you stop the engine? A. No; for a sudden checking of the outflow of steam might bring about an explosion. Do nothing but check the heat as quickly and effectively as you can by banking or covering the fires. Q. Why not turn on the feed water? A. Because the crown sheet of the boiler has become overheated, and any cold water coming upon it would cause an explosion. If the pump or injector are running, of course you may let them run, and the boiler will gradually refill as the heat decreases. Under such circumstances low water is due to overheating the boiler. Q. Would not the fusible plug avert any disaster from low water? A. It might, and it might not. The top of it is liable to get coated with lime so that the device is worthless. You should act at all times precisely as if there were no fusible plug. If it ever does avert an explosion you may be thankful, but averting explosions by taking such means as we have suggested will be far better for an engineer’s reputation. Q. Would not the safety valve be a safeguard against explosion? A. No; only under certain conditions. It prevents too high a pressure for accumulating in the boiler when there is plenty of water; but when the water gets low the safety valve may only hasten the explosion by relieving some of the pressure and allowing superheated water to burst suddenly into steam, thus vastly expanding instantly. Q. Should water be allowed to stand in the boiler when it is not in use? A. It is better to draw it off and clean the boiler, to prevent rusting, formation of scale, hardening of sediment, etc., if boiler is to be left for any great length of time. Q. What should you do if a grate bar breaks or falls out? A. You should always have a spare grate bar on hand to put in its place; but if you have none you may fill the space by wedging in a stick of hard wood cut the right shape to fill the opening. Cover this wood with ashes before poking the fire over it, and it will last for several hours before it burns out. You will find it exceedingly difficult to keep up the fire with a big hole in the grate that will let cold air into the furnace and allow coal to drop down. In case the grate is of the rocker type the opening may be filled by shaping a piece of flat iron, which can be set in without interfering with the rocking of the grate; or the opening may be filled with wood as before if the wood is covered well with ashes. Of course the use of wood will prevent the grate from rocking and the poker must be used to clean. Q. Why should an engineer never start a boiler with a hot fire, and never let his fire get hotter than is needed to keep up steam? A. Both will cause the sheets to warp and the flues to become leaky, because under high heat some parts of the boiler will expand more rapidly than others. For a similar reason, any sudden application of cold to a boiler, either cold water or cold air through the firebox door, will cause quicker contraction of certain parts than other parts, and this will ruin a boiler. Q. How should you supply a boiler with water? A. In a regular stream continually. Only by making the water pass regularly and gradually through the heater will you get the full effect of the heat from the exhaust steam. If a great deal of water is pumped into the boiler at one time, the exhaust steam will not be sufficient to heat it as it ought. Then if you have a full boiler and shut off the water supply, the exhaust steam in the heater is wasted, for it can do no work at all. Besides, it hurts the boiler to allow the temperature to change, as it will inevitably do if water is supplied irregularly. WHATEVER YOU DO, NEVER ATTEMPT TO TIGHTEN A SCREW OR CALK A BOILER UNDER STEAM PRESSURE. IF ANYTHING IS LOOSE IT IS LIABLE TO BLOW OUT IN YOUR FACE WITH DISASTROUS CONSEQUENCES. Q. If boiler flues become leaky, can an ordinary person tighten them? A. Yes, if the work is done carefully. See full explanation previously given, p. 17. Great care should be taken not to expand the flues too much, for by so doing you are likely to loosen other flues and cause more leaks than you had in the first place. Small leaks inside a boiler are not particularly dangerous, but they should be remedied at the earliest possible moment, since they reduce the power of the boiler and put out the fire. Besides, they look bad for the engineer. Q. How should flues be cleaned? A. Some use a steam blower; but a better way is to scrape off the metal with one of the many patent scrapers, which just fill the flue, and when attached to a rod and worked back and forth a few times the whole length of the flue do admirable service. Q. What harm will dirty flues do? A. Two difficulties arise from dirty flues. If they become reduced in size the fire will not burn well. Then, the same amount of heat will do far less work because it is so much harder for it to get through the layer of soot and ashes, which are non-conductors. Q. What would you do if the throttle broke? A. Use reverse lever. CHAPTER VIII. POINTS FOR THE YOUNG ENGINEER.--(CONT.) QUESTIONS AND ANSWERS. THE ENGINE. Q. What is the first thing to do with a new engine? A. With some cotton waste or a soft rag saturated with benzine or turpentine clean off all the bright work; then clean every bearing, box and oil hole, using a force pump with air current first, if you have a pump, and then wiping the inside out clean with an oily rag, using a wire if necessary to make the work thorough. If you do not clean the working parts of the engine thus before setting it up, grit will get into the bearings and cause them to cut. Parts that have been put together need not be taken apart; but you should clean everything you can get at, especially the oil holes and other places that may receive dirt during transportation. After the oil holes have been well cleaned, the oil cups may be wiped off and put in place, screwing them in with a wrench. Q. What kind of oil should you use? A. Cylinder oil only for the cylinder; lard oil for the bearings, and hard grease if your engine is provided with hard grease cup for the cross-head and crank. The only good substitute for cylinder oil is pure beef suet tried out. Merchantable tallow should never be used, as it contains acid. Q. Can fittings be screwed on by hand only? A. No; all fittings should be screwed up tight with a wrench. Q. When all fittings are in place, what must be done before the engine can be started? A. See that the grates in the firebox are in place and all right; then fill the boiler with clean water until it shows an inch to an inch and a half in the water gauge. Start your fire, and let it burn slowly until there is a pressure in the boiler of 10 or 15 lbs. Then you can turn on the blower to get up draft. In the meantime fill all the oil cups with oil; put grease on the gears; open and close all cocks to see that they work all right; turn your engine over a few times to see that it works all right; let a little steam into the cylinder with both cylinder cocks open--just enough to show at the cocks without moving the engine--and slowly turn the engine over, stopping it on the dead centers to see if the steam comes from only one of the cylinder cocks at a time, and that the proper one; reverse the engine and make the same test. Also see that the cylinder oiler is in place and ready for operation. See that the pump is all right and in place, with the valve in the feedpipe open and also the valve in the supply pipe. By going over the engine in this way you will notice whether everything is tight and in working order, and whether you have failed to notice any part which you do not understand. If there is any part or fitting you do not understand, know all about it before you go ahead. Having started your fire with dry wood, add fuel gradually, a little at a time, until you have a fire covering every part of the grate. Regulate the fire by the damper alone, never opening the firebox door even if the fire gets too hot. Q. In what way should the engine be started? A. When you have from 25 to 40 lbs. of pressure open the throttle valve a little, allowing the cylinder cocks to be open also. Some steam will condense at first in the cold cylinder, and this water must be allowed to drain off. See that the crank is not on a dead center, and put on just enough steam to start the engine. As soon as it gets warmed up, and only dry steam appears at the cocks, close the cylinder cocks, open the throttle gradually till it is wide open, and wait for the engine to work up to its full speed. Q. How is the speed of the engine regulated? A. By the governor, which is operated by a belt running to the main shaft. The governor is a delicate apparatus, and should be watched closely. It should move up and down freely on the stem, which should not leak steam. If it doesn’t work steadily, you should stop the engine and adjust it, after watching it for a minute or two to see just where the difficulty lies. Q. Are you likely to have any hot boxes? A. There should be none if the bearings are all clean and well supplied with oil. However, in starting a new engine you should stop now and then and examine every bearing by laying your hand upon it. Remember the eccentric, the link pin, the cross-head, the crank pin. If there is any heat, loosen the boxes up a trifle, but only a very little at a time. If you notice any knocking or pounding, you have loosened too much, and should tighten again. Q. What must you do in regard to water supply? A. After the engine is started and you know it is all right, fill the tank on the engine and start the injector. It may take some patience to get the injector started, and you should carefully follow the directions previously given and those which apply especially to the type of injector used. Especially be sure that the cocks admitting the water through the feed pipe and into the boiler are open. Q. Why are both a pump and an injector required on an engine? A. The pump is most economical, because it permits the heat in the exhaust steam to be used to heat the feed water, while the injector heats the water by live steam. There should also be an injector, however, for use when the engine is not working, in order that the water in the boiler may be kept up with heated water. If a cross-head pump is used, of course, it will not operate when the engine is not running; and in case of an independent pump the heater will not heat the water when the engine is not running because there is little or no exhaust steam available. There is an independent pump (the Marsh pump) which heats the water before it goes into the boiler, and this may be used when the engine is shut down instead of the injector. Q. What is the next thing to test? A. The reversing mechanism. Throw the reverse lever back, and see if the engine will run equally well in the opposite direction. Repeat this a few times to make sure that the reverse is in good order. Q. How is a traction engine set going upon the road? A. Most traction engines now have the friction clutch. When the engine is going at full speed, take hold of the clutch lever and slowly bring the clutch against the band wheel. It will slip a little at first, gradually engaging the gears and moving the outfit. Hold the clutch lever in one hand, while with the other you operate the steering wheel. By keeping your hand on the clutch lever you may stop forward motion instantly if anything goes wrong. When the engine is once upon the road, the clutch lever may set in the notch provided for it, and the engine will go at full speed. You can then give your entire attention to steering. Q. What should you do if the engine has no friction clutch? A. Stop the engine, placing the reversing lever in the center notch. Then slide the spur pinion into the gear and open the throttle valve wide. You are now ready to control the engine by the reversing lever. Throw the lever forward a little, bringing it back, and so continue until you have got the engine started gradually. When well under way throw the reverse lever into the last notch, and give your attention to steering. Q. How should you steer a traction engine? A. In all cases the same man should handle the throttle and steer the engine. Skill in steering comes by practice, and about the only rule that can be given is to go slow, and under no circumstances jerk your engine about. Good steering depends a great deal on natural ability to judge distances by the eye and power by the feel. A good engineer must have a good eye, a good ear, and a good touch (if we may so speak). If either is wanting, success will be uncertain. Q. How should an engine be handled on the road? A. There will be no special difficulty in handling an engine on a straight, level piece of road, especially if the road is hard and without holes. But when you come to your first hill your troubles will begin. Before ascending a hill, see that the water in the boiler does not stand more than two inches in the glass gauge. If there is too much water, as it is thrown to one end of the engine by the grade it is liable to get into the steam cylinder. If you have too much water, blow off a little from the bottom blow-off cock. In descending a hill never stop your engine for a moment, since your crown sheet will be uncovered by reason of the water being thrown forward, and any cessation in the jolting of the engine which keeps the water flowing over the crown sheet will cause the fusible plug to blow out, making delay and expense. Make it a point never to stop your engine except on the level. Before descending a hill, shut off the steam at the throttle, and control the engine by the friction brake; or if there is no brake, do not quite close the throttle, but set the reverse lever in the center notch, or back far enough to control the speed. It is seldom necessary to use steam in going down hill, however, and if the throttle is closed even with no friction brake, the reverse may be used in such a way as to form an air brake in the cylinder. Get down to the bottom of a hill as quickly as you can. Before descending a hill it would be well to close your dampers and keep the firebox door closed tight all the time. Cover the fire with fresh fuel so as to keep the heat down. The pump or injector must be kept at work, however, since as you have let the water down low, you must not let it fall any lower or you are likely to have trouble. In ascending a hill, do just the reverse, namely: Keep your fire brisk and hot, with steam pressure ascending; and throw the reverse lever in the last notch, giving the engine all the steam you can, else you may get stuck. If you stop you are likely to overheat forward end of fire tubes. You are less liable to get stuck if you go slowly than if you go fast. Regulate speed by friction clutch. CHAPTER IX. POINTS FOR THE YOUNG ENGINEER.--(CONT.) MISCELLANEOUS. Q. What is Foaming? A. The word is used to describe the rising of water in large bubbles or foam. You will detect it by noticing that the water in the glass gauge rises and falls, or is foamy. It is due to sediment in the boiler, or grease and other impurities in the feed supply. Shaking up the boiler will start foaming sometimes; at other times it will start without apparent cause. In such cases it is due to the steam trying to get through a thick crust on the surface of the water. Q. How may you prevent foaming? A. It may be checked for a moment by turning off the throttle, so giving the water a chance to settle. It is generally prevented by frequently using the surface blow-off to clear away the scum. Of course the water must be kept as pure as possible, and especially should alkali water be avoided. Q. What is priming? A. Priming is not the same as foaming, though it is often caused by foaming. Priming is the carrying of water into the steam cylinder with the steam. It is caused by various things beside foaming, for it may be found when the boiler is quite clean. A sudden and very hot fire may start priming. Priming sometimes follows lowering of the steam pressure. Often it is due to lack of capacity in the boiler, especially lack of steam space, or lack of good circulation. Q. How can you detect priming? A. By the clicking sound it makes in the steam cylinder. The water in the gauge will also go up and down violently. There will also be a shower of water from the exhaust. Q. What is the proper remedy for priming? A. If it is due to lack of capacity in the boiler nothing can be done but get a new boiler. In other cases it may be remedied by carrying less water in the boiler when that can be done safely, by taking steam from a different point in the steam dome, or if there is no dome by using a long dry pipe with perforation at the end. A larger steam pipe may help it; or it may be remedied by taking out the top row of flues. Leaky cylinder rings or a leaky valve may also have something to do with it. In all cases these should be made steam tight. If the exhaust nozzle is choked up with grease or sediment, clean it out. A traction engine with small steam ports would prime quickly under forced speed. Q. How would you bank your fires? A. Push the fire as far to the back of the firebox as possible and cover it over with very fine coal or with dry ashes. As large a portion as possible of the grate should be left open, so that the air may pass over the fire. Close the damper tight. By banking your fires at night you keep the boiler warm and can get up steam more quickly in the morning. Q. When water is left in the boiler with banked fire in cold weather, what precautions ought to be taken? A. The cocks in the glass water gauge should be closed and the drain cock at the bottom opened, for fear the water in the exposed gauge should freeze. Likewise all drain cocks in steam cylinder and pump should be opened. Q. How should a traction engine be prepared for laying up during the winter? A. First, the outside of the boiler and engine should be thoroughly cleaned, seeing that all gummy oil or grease is removed. Then give the outside of the boiler and smokestack a coat of asphalt paint, or a coat of lampblack and linseed oil, or at any rate a doping of grease. The outside of the boiler should be cleaned while it is hot, so that grease, etc., may be easily removed while soft. After the outside has been attended to, blow out the water at low pressure and thoroughly clean the inside in the usual way, taking out the handhole and manhole plates, and scraping off all scale and sediment. After the boiler has been cleaned on the inside, fill it nearly full of water, and pour upon the top a bucket of black oil. Then let the water out through the blow-off at the bottom. As the water goes down it will have a coating of oil down the sides of the boiler. All the brass fittings should be removed, including gauge cocks, check valves, safety valve, etc. Disconnect all pipes that may contain water, to be sure none remains in any of them. Open all stuffing boxes and take out packing, for the packing will cause the parts they surround to rust. Finally, clean out the inside of the firebox and the fire flues, and give the ash-pan a good coat of paint all over, inside as well as out. The inside of the cylinder should be well greased, which can be done by removing the cylinder head. See that the top of the smoke stack is covered to keep out the weather. All brass fittings should be carefully packed and put away in a dry place. A little attention to the engine when you put it up will save twice as much time when you take it out next season, and besides save many dollars of value in the life of the engine. Q. How should belting be cared for? A. First, keep belts free from dust and dirt. Never overload belts. Do not let oil or grease drip upon them. Never put any sticky or pasty grease on a belt. Never allow any animal oil or grease to touch a rubber belt, since it will destroy the life of the rubber. The grain or hair side should run next the pulley, as it holds better and is not so likely to slip. Rubber belts will be greatly improved if they are covered with a mixture of black lead and litharge, equal parts, mixed with boiled oil, and just enough japan to dry them quickly. This mixture will do to put on places that peel. Q. What is the proper way to lace a belt? A. First, square the ends with a proper square, cutting them off to a nicety. Begin to lace in the middle, and do not cross the laces on the pulley side. On that side the lacings should run straight with the length of the belt. The holes in the belt should be punched if possible with an oval punch, the long diameter coinciding with the length of the belt. Make two rows of holes in each end of the belt, so that the holes in each row will alternate with those in preceding row, making a zigzag. Four holes will be required for a three-inch belt in each end, two holes in each row; in a six-inch belt, place seven holes in each end, four in the row nearest the end. To find the length of a belt when the exact length cannot be measured conveniently, measure a straight line from the center of one pulley to the center of the other. Add together half the diameter of each pulley, and multiply that by 3¼ (3.1416). The result added to twice the distance between the centers will give the total length of the belt. A belt will work best if it is allowed to sag just a trifle. The seam side of a rubber belt should be placed outward, or away from the pulley. If such a belt slips, coat the inside with boiled linseed oil or soap. Cotton belting may be preserved by painting the pulley side while running with common paint, afterward applying soft oil or grease. If a belt slips apply a little oil or soap to the pulley side. Q. How does the capacity of belts vary? A. In proportion to width and also to the speed. Double the width and you double the capacity; also, within a certain limit, double the speed and you double the capacity. A belt should not be run over 5,000 feet per minute. One four-inch belt will have the same capacity as two two-inch belts. Q. How are piston rods and valve rods packed so that the steam cannot escape around them? A. By packing placed in stuffing-boxes. The stuffing is of some material that has a certain amount of elasticity, such as lamp wick, hemp, soap stone, etc., and certain patent preparations. The packing is held in place by a gland, as it is called, which acts to tighten the packing as the cap of the stuffing-box is screwed up. Q. How would you repack a stuffing-box? A. First remove the cap and the gland, and with a proper tool take out all the old packing. Do not use any rough instrument like a file, which is liable to scratch the rod, for any injury to the smooth surface of the rod will make it leak steam or work hard. If patent packing is used, cut off a sufficient number of lengths to make the required rings. They should be exactly the right length to go around inside the stuffing-box. If too long, they cannot be screwed up tight, as the ends will press together and cause irregularities. If too short, the ends will not meet and will leak steam. Cut the ends diagonally so that they will make a lap joint instead of a square one. When the stuffing-box has been filled, place the gland in position and screw up tight. Afterwards loosen the nuts a trifle, as the steam will cause the packing to expand, usually. The stuffing-box should be just as loose as it can be and not allow leakage of steam. If steam leaks, screw up the box a little tighter. If it still leaks, do not screw up as tight as you possibly can, but repack the box. If the stuffing-box is too tight, either for the piston rod or valve steam, it will cause the engine to work hard, and may groove the rods and spoil them. If hemp packing is used, pull the fibres out straight and free, getting rid of all knots and lumps. Twist together a few of the fibres, making three cords, and braid these three cords together and soak them with oil or grease, wind around the rod till stuffing-box is sufficiently full, replace the gland, and screw up as before. Stuffing-box for water piston of pump may be packed as described above, but little oil or grease will be needed. Never pack the stuffing-box too tight, or you may flute the rod and spoil it. Always keep the packing in a clean place, well covered up, never allowing any dust to get into it, for the dust or grit is liable to cut the rod. CHAPTER X. ECONOMY IN RUNNING A FARM ENGINE. It is something to be able to run a farm engine and keep out of trouble. It is even a great deal if everything runs smoothly day in and day out, if the engine looks clean, and you can always develop the amount of power you need. You must be able to do this before you can give the fine points of engineering much consideration. When you come to the point where you are always able to keep out of trouble, you are probably ready to learn how you can make your engine do more work on less fuel than it does at present. In that direction the best of us have an infinite amount to learn. It is a fact that in an ordinary farm engine only about 4 per cent of the coal energy is actually saved and used for work; the rest is lost, partly in the boiler, more largely in the engine. So we see what a splendid chance there is to save. If we are asked where all the lost energy goes to, we might reply in a general sort of way, a good deal goes up the smokestack in smoke or unused fuel; some is radiated from the boiler in the form of heat and is lost without producing any effect on the steam within the boiler; some is lost in the cooling of the steam as it passes to the steam cylinder; some is lost in the cooling of the cylinder itself after each stroke; some is lost through the pressure on the back of the steam valve, causing a friction that requires a good deal of energy in the engine to overcome; some is lost in friction in the bearings, stuffing-boxes, etc. At each of these points economy may be practiced if the engineer knows how to do it. We offer a few suggestions. THEORY OF STEAM POWER. As economy is a scientific question, we cannot study it intelligently without knowing something of the theory of heat, steam and the transmission of power. There will be nothing technical in the following pages; and as soon as the theory is explained in simple language, any intelligent person will know for himself just what he ought to do in any given case. First, let us define or describe heat according to the scientific theory. Scientists suppose that all matter is made up of small particles called molecules, so small that they have never been seen. Each molecule is made up of still smaller particles called atoms. There is nothing smaller than an atom, and there are only about sixty-five different kinds of atoms, which are called elements; or rather, any substance made up of only one kind of atom is called an element. Thus iron is an element, and so is zinc, hydrogen, oxygen, etc. But a substance like water is not an element, but a compound, since its molecules are made up of an atom of oxygen united with two atoms of hydrogen. Wood is made up of many different kinds of atoms united in various ways. Air is not a compound, but a mixture of oxygen, nitrogen and a few other substances in small quantities. The reason why air is a mixture and not a compound is an interesting one, and brings us to our next point. In order to form a compound, two different kinds of atoms must have an attraction for each other. There is no attraction between oxygen and nitrogen; but there is great attraction between oxygen and carbon, and when they get a chance they rush together like long separated lovers. Anthracite coal is almost pure carbon. So is charcoal. Soft coal consists of carbon with which various other things are united, one of them being hydrogen. This is interesting and important, because it accounts for a curious thing in firing up boilers with soft coal. We have already said that water is oxygen united with hydrogen. When soft coal burns, not only does the carbon unite with oxygen, but the hydrogen unites with oxygen and forms water, or steam. While the boilers are cold they will condense the water or steam in the smoke, just as a cold plate in a steamy room will condense water from the steamy air, so sweating. Now the scientists suppose that two or three atoms stick together by reason of their attraction for each other and form molecules. These molecules in turn stick together and form liquids and solids. The tighter they stick, the harder the substance. At the same time, these molecules are more or less loose, and are constantly moving back and forth. In a solid like iron they move very little; but a current of electricity through iron makes the molecules move in a peculiar way. In a liquid like water, the molecules cling together very loosely, and may easily be pulled apart. In any gas, like air or steam, the molecules are entirely disconnected, and are constantly trying to get farther apart. Heat, says the scientist, is nothing more or less than the movement of the molecules back and forth. Heat up a piece of iron in a hot furnace, and the molecules keep getting further and further apart, and the iron gets softer and softer, till it becomes a liquid. If we take some liquid like water and heat it, the molecules get farther and farther apart, till the water boils, as we say, or turns into steam. As steam the molecules have broken apart entirely, and are beating back and forth so rapidly that they have a tendency to push each other farther and farther apart. This pushing tendency is the cause of steam pressure. It also explains why steam has an expansive power. Heat, then, is the movement of the molecules back and forth. There are three fixed ranges in which they move; the small range makes a solid; the next range makes a liquid; the third range makes a gas, such as steam. These three states of matter as affected by heat are very sharp and definite. The point at which a solid turns to a liquid is called the melting point. The melting point of ice is 32° Fahr. The point at which it turns to a gas is called the boiling point. With water that is 212° Fahr. The general tendency of heat is to push apart, or expand; and when the heat is taken away the substances contract. Let us consider our steam boiler. We saw that some different kinds of atoms have a strong tendency to rush together; for example, oxygen and carbon. The air is full of oxygen, and coal and wood are full of carbon. When they are raised to a certain temperature, and the molecules get loose enough so that they can tear themselves away from whatever they are attached to, they rush together with terrible force, which sets all surrounding molecules to vibrating faster than ever. This means that heat is given out. Another important thing is that when a solid changes to a liquid, or a liquid to a gas, it must take up a certain amount of heat to keep the molecules always just so far apart. That heat is said to become latent, for it will not show in a thermometer, it will not cause anything to expand, nor will it do any work. It merely serves to hold the molecules just so far apart. HOW ENERGY IS LOST. We may now see some of the ways in which energy is lost. First, the air which goes into the firebox consists of nitrogen as well as oxygen. That nitrogen is only in the way, and takes heat from the fire, which it carries out at the smokestack. Again, if the air cannot get through the bed of coals easily enough, or there is not enough of it so that every atom of carbon, etc., will find the right number of atoms of oxygen, some of the atoms of carbon will be torn off and united with oxygen, and the other atoms of carbon, left without any oxygen to unite with, will go floating out at the smokestack as black smoke. Also, the carbon and the oxygen cannot unite except at a certain temperature, and when fresh fuel is thrown on the fire it is cold, and a good many atoms of carbon after being loosened up, get cooled off again before they have a chance to find an atom of oxygen, and so they, too, go floating off and are lost. If the smoke could be heated up, and there were enough oxygen mixed with it, the loose carbon would still burn and produce heat, and there would be an economy of fuel. This has given rise to smoke consumers, and arranging two boilers, so that when one is being fired the heat from the other will catch the loose carbon before it gets away and burn it up. So we have these points: 1. Enough oxygen or air must get into a furnace so that every atom of carbon will have its atom of oxygen. This means that you must have a good draft and that the air must have a chance to get through the coal or other fuel. 2. The fuel must be kept hot enough all the time so that the carbon and oxygen can unite. Throwing on too much cold fuel at one time will lower the heat beyond the economical point and cause loss in thick smoke. 3. If the smoke can pass over a hot bed of coals, or through a hot chamber, the carbon in it may still be burned. This suggests putting fuel at the front of the firebox, a little at a time, so that its smoke will have to pass over a hot bed of coals and the waste carbon will be burned. When the fresh fuel gets heated up, it may be pushed farther back. From a practical point of view these points mean, No dead plates in a furnace to keep the air from going through coal or wood; a thin fire so the air can get through easily; place the fresh fuel where its smoke will have a chance to be burned; and do not cool off the furnace by putting on much fresh fuel at a time. (Later we will give more hints on firing.) HOW HEAT IS DISTRIBUTED. We have described heat as the movement of molecules back and forth at a high rate of speed. If these heated molecules beat against a solid like iron, its molecules are set in motion, one knocks the next, and so on, just as you push one man in a crowd, he pushes the next, and so on till the push comes out on the other side. So heat passes through iron and appears on the other side. This is called “conduction.” All space is supposed to be filled with a substance in which heat, light, etc., may be transmitted, called the ether. When the molecules of a sheet of iron are heated, or set vibrating, they transmit the vibration through the air, or ether. This is called “radiation.” Heat is “conducted” through solid and liquid substances, and “radiated” through gases. Now some substances conduct heat readily, and some do so with the greatest difficulty. Iron is a good conductor; carbon, or soot on the flues of a boiler, and lime or scale on the inside of a boiler, are very poor conductors. So the heat will go through the iron and steel to the water in a boiler quickly and easily, and a large per cent of the heat of the furnace will get to the water in a boiler. When a boiler is old and is clogged with soot and coated with lime, the heat cannot get through easily, and goes off in the smokestack. The air coming out of the smokestack will be much hotter; and that extra heat is lost. Iron is a good radiator, too. So if the outer shell of a boiler is exposed to the air, a great deal of heat will run off into space and be lost. Here, then, is where you need a non-conductor, as it is called, such as lime, wood, or the like. Economy says, cover the outside of a boiler shell with a non-conductor. This may be brickwork in a set boiler; in a traction boiler it means a jacket of wood, plaster, hair, or the like. The steam pipe, if it passes through outer air, should be covered with felt; and the steam cylinder ought to have its jacket, too. At the same time all soot and all scale should be scrupulously cleaned away. PROPERTIES OF STEAM. As we have already seen, steam is a gas. It is slightly blue in color, just as the water in the ocean is blue, or the air in the sky. We must distinguish between steam and vapor. Vapor is small particles of water hanging in the air. They seem to stick to the molecules composing the air, or hang there in minute drops. Water hanging in the air is, of course, water still. Its molecules do not have the movement that the molecules of a true gas do, such as steam is. Steam, moreover, has absorbed latent heat, and has expansive force; but vapor has no latent heat, and no expansive force. So vapor is dead and lifeless, while steam is live and full of energy to do work. When vapor gets mixed with steam it is only in the way; it is a sort of dead weight that must be carried; and the steam power is diminished by having vapor mixed with it. Now all steam as it bubbles up through water in boiling takes up with it a certain amount of vapor. Such steam is called “wet” steam. When the vapor is no longer in it, the steam is called “dry” steam. It is dry steam that does the best work, and that every engineer wants to get. While water will be taken up to great heights in the air and form clouds, in steam it will not rise very much, and at a certain height above the level of the water in a boiler the steam will be much drier than near the surface. For this reason steam domes have been devised, so that the steam may be taken out at a point as high as possible above the water in the boiler, and so be as dry as possible. Also “dry tubes” have been devised, which let the steam pass through many small holes that serve to keep back the water to a certain extent. However, there will be more or less moisture in all steam until it has been superheated, as it is called. This may be done by passing it through the hot part of the furnace, where the added heat will turn all the moisture in the steam into steam, and we shall have perfectly dry steam. The moment, however, that steam goes through a cold pipe, or one cooled by radiation, or goes into a cold cylinder, or a cylinder cooled by radiation, some of the steam will turn to water, or condense, as it is called. So we have the same trouble again. Much moisture passing into the cylinder with the steam is called “priming.” In that case the dead weight of water has become so great as to kill a great part of the steam power. HOW TO USE THE EXPANSIVE POWER OF STEAM. We have said that the molecules in steam are always trying to get farther and farther apart. If they are free in the air, they will soon scatter; but if they are confined in a boiler or cylinder they merely push out in every direction, forming “pressure.” When steam is let into the cylinder it has the whole accumulated pressure in the boiler behind it, and of course that exerts a strong push on the piston. Shut off the boiler pressure and the steam in the cylinder will still have its own natural tendency to expand. As the space in the cylinder grows larger with the movement of the piston from end to end, the expansive power of the steam becomes less and less, of course. However, every little helps, and the push this lessened expansive force exerts on the piston is so much energy saved. If the full boiler pressure is kept on the piston the whole length of the stroke, and then the exhaust port is immediately opened, all this expansive energy of the steam is lost. It escapes through the exhaust nozzle into the smokestack and is gone. Possibly it cannot get out quickly enough, and causes back pressure on the cylinder when the piston begins its return stroke, so reducing the power of the engine. To save this the skilled engineer “notches up” his reverse lever, as they say. The reverse lever controls the valve travel. When the lever is in the last notch the valve has its full travel. When the lever is in the center notch the valve has no travel at all, and no steam can get into the cylinder; on the other side the lever allows the valve to travel gradually more and more in the opposite direction, so reversing the engine. As the change from one direction to the other direction is, of course, gradual, the valve movement is shortened by degrees, and lets steam into the cylinder for a correspondingly less time. At its full travel it perhaps lets steam into the cylinder for three-quarters of its stroke. For the last quarter the work is done by the expansive power of the steam. Set the lever in the half notch, and the travel of the valve is so altered that steam can get into the cylinder only during half the stroke of the piston, the work during the rest of the stroke being done by the expansive force of the steam. Set the lever in the notch next to the middle notch, or the quarter notch, and steam will get into the cylinder only during a quarter of the stroke of the piston, the work being done during three-quarters of the stroke by the expansive force of the steam. Obviously the more the steam is expanded the less work it can do. But when it escapes at the exhaust there will be very little pressure to be carried away and lost. Therefore when the load on his engine is light the economical engineer will “notch up” his engine with the reverse lever, and will use up correspondingly less steam and save correspondingly more fuel. When the load is unusually heavy, however, he will have to use the full power of the pressure in the boiler, and the waste cannot be helped. THE COMPOUND ENGINE. The compound engine is an arrangement of steam cylinders to save the expansive power of steam at all times by letting the steam from one cylinder where it is at high pressure into another after it exhausts from the first, in this second cylinder doing more work purely by the expansive power of the steam. The illustration shows a sectional view of a compound engine having two cylinders, one high pressure and one low. The low pressure cylinder is much larger than the high pressure. There is a single plate between them called the center head, and the same piston rod is fitted with two pistons, one for each cylinder. The steam chest does not receive steam from the boiler, but from the exhaust of the high pressure cylinder. The steam from the boiler goes into a chamber in the double valve, from which it passes to the ports of the high pressure cylinder. At the return stroke the exhaust steam escapes into the steam chest, and from there it passes into the low pressure cylinder. There may be one valve riding on the back of another; but the simplest form of compound engine is built with a single double valve, which opens and closes the ports for both cylinders at one movement. [Illustration: WOOLF TANDEM CYLINDER.] Theoretically the compound engine should effect a genuine economy. In practice there are many things to operate against this. Of course if the steam pressure is low to start with, the amount of pressure lost in the exhaust will be small. But if it is very high, the saving in the low pressure cylinder will be relatively large. If the work can be done just as well with a low pressure, it would be a practical waste to keep the pressure abnormally high in order to make the most of the compound engine. An engine must be a certain size before the saving of a compound cylinder will be appreciable. In these days nearly all very large engines are compound, while small engines are simple. Another consideration to be taken into account is that a compound is more complicated and so harder to manage; and when any unfavorable condition causes loss it causes proportionately more loss on a compound than on a simple engine. For these and other reasons compound engines have been used less for traction purposes than simple engines have. It is probable that a skilled and thoroughly competent engineer, who would manage his engine in a scientific manner, would get more out of a compound than out of a simple; and this would be especially true in regions where fuel is high. If fuel is cheap and the engineer unskilled, a compound engine would be a poor economizer. FRICTION. We have seen that the molecules of water have a tendency to stick in the steam as vapor or moisture. All molecules that are brought into close contact have more or less tendency to stick together, and this is called friction. The steam as it passes along the steam pipe is checked to a certain extent by the friction on the sides of the pipe. Friction causes heat, and it means that the heat caused has been taken from some source of energy. The friction of the steam diminishes the energy of the steam. So, too, the fly wheel moving against the air suffers friction with the air, besides having to drive particles of air out of its path. All the moving parts of an engine where one metal moves on another suffer friction, since where the metals are pressed very tightly together they have more tendency to stick than when not pressed so tightly. When iron is pressed too tightly, as under the blows of a hammer in a soft state, it actually welds together solidly. There is a great deal of friction in the steam cylinder, since the packing rings must press hard against the walls of the cylinder to prevent the steam from getting through. There is a great deal of friction between the D valve and its seat, because of the high steam pressure on the back of the valve. There is friction in the stuffing boxes both of the valve and the piston. There is friction at all the bearings. There are various ways in which friction may be reduced. The most obvious is to adjust all parts so nicely that they will bind as little as possible. The stuffing-boxes will be no tighter than is necessary to prevent leaking of steam; and so with the piston rings. Journal boxes will be tight enough to prevent pounding, but no tighter. To obtain just the right adjustment requires great patience and the keen powers of observation and judgment. The makers of engines try to reduce friction as much as possible by using anti-friction metals in the boxes. Iron and steel have to be used in shafts, gears, etc., because of the strength that they possess; but there are some metals that stick to each other and to iron and steel much less than iron or steel stick to each other when pressed close together. These metals are more or less soft; but they may be used in boxes and journal bearings. They are called anti-friction metals. The hardest for practical purposes is brass, and brass is used where there is much wear. Where there is less wear various alloys of copper, tin, zinc, etc., may be used in the boxes. One of these is babbit metal, which is often used in the main journal box. All these anti-friction metals wear out rapidly, and they must be put in so that they can be adjusted or renewed easily. But the great anti-friction agent is oil. Oil is peculiar in that while the molecules seem to stick tightly together and to a metal like iron or steel, they roll around upon each other with the utmost ease. An ideal lubricator is one that sticks so tight to the journal that it forms a sort of cushion all around it, and prevents any of its molecules coming into contact with the molecules of the metal box. All the friction then takes place between the different molecules of oil, and this friction is a minimum. The same principle has been applied to mechanics in the ball bearing. A number of little balls roll around between the journal and its box, preventing the two metals from coming into contact with each other; while the balls, being spheres, touch each other only at a single point, and the total space at which sticking can occur is reduced to a minimum. As is well known, there is great difference in oils. Some evaporate, like gasoline and kerosene, and so disappear quickly. Others do not stick tightly to the journal, so are easily forced out of place, and the metals are allowed to come together. What is wanted, then, is a heavy, sticky oil that will not get hard, but will always form a good cushion between bearings. Steam cylinders cannot be oiled directly, but the oil must be carried to the steam chest and cylinder in the steam. A good cylinder oil must be able to stand a high temperature. While it is diffused easily in the steam, it must stick tightly to the walls of the steam cylinder and to the valve seat, and keep them lubricated. Once it is stuck to the metal, the heat of the steam should not evaporate it and carry it away. Again, a cylinder oil should not have any acid in it which would have a tendency to corrode the metal. Nearly all animal fats do have some such acid. So tallow and the like should not be placed where they can corrode iron or steel. Lard and suet alone are suitable for use on an engine. When it comes to lubricating traction gears, other problems appear. A heavy grease will stick to the gears and prevent them from cutting; but it will stick equally to all sand and grit that may come along, and that, working between the cogs, may cut them badly. So some engineers recommend the use on gears of an oil that does not gather so much dirt. The friction of the valve on its seat due to the pressure of the steam on its back has given rise to many inventions for counteracting it. The most obvious of these is what is called “the balanced valve.” In the compound engine, where the steam pressure is obtained upon both sides of the valve, it rides much more lightly on its seat--so lightly, indeed, that when steam pressure is low, as in going down hill or operating under a light load, plunger pistons must be used to keep the valve down tight on its seat. The poppet valves were devised to obviate the undue friction of the D valve; but the same loss of energy is to a certain extent transferred, and the practical saving is not always equal to the theoretical. On large stationary engines rotary valves and other forms, such as are used on the Corliss engine, have come into common use; but they are too complicated for a farm engine, which must be as simple as possible, with least possible liability of getting out of order. CHAPTER XI. ECONOMY IN RUNNING A FARM ENGINE.--(CONT.) PRACTICAL POINTS. The first practical point in the direction of farm engine economy is to note that the best work can be done only when every part of the engine and boiler are in due proportion. If the power is in excess of the work to be done there is loss; if the grate surface is too large cold air gets through the fuel and prevents complete combustion, and if the grate surface is too small, not enough air gets in; if the steaming power of the boiler is too large, heat is radiated away that otherwise could be saved, for every foot of exposed area in the boiler is a source of loss; if the steaming power of the boiler is too low for the work to be done, it requires extra fuel to force the boiler to do its work, and any forcing means comparatively large loss or waste. It will be seen that not only must the engine and boiler be built with the proper proportions, but they must be bought with a nice sense of proportion to the work expected of them. This requires excellent judgment and some experience in measuring work in horsepowers. GRATE SURFACE AND FUEL. The grate surface in a firebox should be not less than two-thirds of a square foot per horsepower, for average size traction engines. If the horsepower of an engine is small, proportionately more grate surface will be needed; if it is large, the grate surface may be proportionately much smaller. An engine boiler 7×8×200 rev., with 100 lbs. pressure, should have a grate surface not less than six square feet, and seven would be better. In a traction engine there is always a tendency to make the grate surface as small as possible, so that the engine will not be cumbersome. Another reason why the grate surface should be sufficiently large is that forced draft is a bad thing, since it has a tendency to carry the products of combustion and hot gases through the smokestack and out into space before they have time to complete combustion and especially before the heat of the gases has time to be absorbed by the boiler surface. A large grate surface, then, with a moderate draft, is the most economical. The draft depends on other things, however. If a great deal of fine fuel is thrown on a fire, the air must be forced through, because it cannot get through in the natural way. This results in waste. So a fire should be as open as possible. Coal should be “thin” on the grates; wood should be thrown in so that there will be plenty of air spaces; straw should be fed in just so that it will burn up completely as it goes in. Moderate size coal is better than small or fine. Dust in coal checks the draft. A good engineer will choose his fuel and handle his fire so that he can get along with as little forced draft as possible. In a straw burning engine a good circulation of air can be obtained, if the draft door is just below the straw funnel, by extending the funnel into the furnace six inches or so. This keeps the straw from clogging up the place where the air enters and enables it to get at the fuel so much more freely that the combustion is much more complete. We have already suggested that in firing with coal, the fresh fuel be deposited in front, so that the smoke will have to pass over live coals and so the combustion will be more complete. Then when the coal is well lighted it can be poked back over the other portions of the grate. This method has another advantage, in that the first heating is usually sufficient to separate the pure coal from the mineral substances which form clinkers, and most of the clinkers will be deposited at that one point in the grate. Here they can easily be lifted out, and will not seriously interfere with the burning of the coal as they would if scattered all over the grate. Clinkers in front can easily be taken out by hooking the poker over them toward the back of the firebox and pulling them up and to the front. They often come out as one big mass which can be easily lifted out. The best time to clean the grate is when there is a good brisk fire. Then it will not cause steam to go down. Stirring a fire does little good. For one thing, it breaks up the clinkers and allows them to run down on the grate bars when they stick and finally warp the bars. If the fire is not stirred the clinkers can be lifted out in large masses. Stirring a fire also creates a tendency to choke up or coke, and interferes with the even and regular combustion of the coal at all points. The highest heat that can be produced is a yellow heat. When there is a good yellow heat, forced draft will only carry off the heat and cause waste. It will not cause still more rapid combustion. When the heat is merely red, increased draft will raise the temperature. Combustion is not complete until the flame shows yellow. However, if the draft is slight and time is given, red heat will be nearly as effective, but it will not carry the heated gases over so large a part of the heating surface of the boiler. With a very large grate surface, red heat will do very well. Certainly it will be better than a forced draft, or an effort at heating beyond the yellow point. BOILER HEATING SURFACE. The heat of the furnace does its work only as the heated gases touch the boiler surface. The iron conducts the heat through to the water, which is raised to the boiling point and turned into steam. Now the amount of heat that the boiler will take up is directly in proportion to the amount of exposed surface and to the time of exposure. If the boiler heating surface is small, and the draft is forced so that the gases pass through rapidly, they do not have a chance to communicate much heat. Also if the heating surface is too large, so that it cannot all be utilized, the part not used becomes a radiating surface, and the efficiency of the boiler is impaired. Practice has shown that the amount of heating surface practically required by a boiler is 12 to 15 square feet per horsepower. In reckoning heating surface, all area which the heated gases touch is calculated. Another point in regard to heating surface in the production of steam is this, that only such surface as is exposed to a heat equal to turning the water into steam is effective. If there is a pressure of 150 lbs. the temperature at which the water would turn to steam would be 357 degrees, and any gases whose temperature was below 357 degrees would have no effect on the heating surface except to prevent radiation. Thus in a return flue boiler the heated gases become cooled often to such an extent before they pass out at the smokestack that they do not help the generation of steam. Yet a heat just below 357 degrees would turn water into steam under 149 lbs. pressure. Though it has work in it, the heat is lost. Another practical point as to economy in large heating surface is that it costs money to make, and is cumbersome to move about. It may cost more to move a traction engine with large boiler from place to place than the saving in fuel would amount to. So the kind of roads and the cost of fuel must be taken into account and nicely balanced. However, it may be said that a boiler with certain outside dimensions that will generate 20 horsepower will be more economical than one of the same size that will generate only 10 horsepower. In selecting an engine, the higher the horsepower for the given dimensions, the more economical of both fuel and water. The value of heating surface also depends on the material through which the heat must penetrate, and the rapidity with which the heat will pass. We have already pointed out that soot and lime scale permit heat to pass but slowly and if they are allowed to accumulate will greatly reduce the steaming power of a boiler for a given consumption of fuel. Another point is that the thinner the iron or steel, the better will the heat get through even that. So it follows that flues, being thinner, are better conductors than the sides of the firebox. Long flues are better than short ones in that the long ones allow less soot, etc., to accumulate than the short ones do, and afford more time for the boiler to absorb the heat of the gases. Again, we have stated that heating surface is valuable only as it is exposed to the gases at a sufficiently high temperature. Some boilers have a tendency to draw the hot gases most rapidly through the upper flues, while the lower flues do not get their proportion of the heat. This results in a loss, for the heat to give its full benefit should be equally distributed. To prevent the heat being drawn too rapidly through upper flues, a baffle plate may be placed in the smoke box just above the upper flues, thus preventing them from getting so much of the draft. Again, if the exhaust nozzle is too low down, the draft through the lower flues may be greater than through the upper. This is remedied by putting a piece of pipe on the exhaust to raise it higher in the smokestack. EXPANSION AND CONDENSATION. We have already pointed out that economy results if we hook up the reverse lever so that the expansive force of the steam has an opportunity to work during half or three-quarters of the stroke. One difficulty arising from this method is that the walls of the cylinder cool more rapidly when not under the full boiler pressure. Condensation in the cylinder is a practical difficulty which should be met and overcome as far as possible. High speed gives some advantage. A judicious use of cushion helps condensation somewhat also, because when any gas like steam or air is compressed, it gives off heat, and this heat in the cushion will keep up the temperature of the cylinder. This cannot be carried very far, however, for the back pressure of cushion will reduce the energy of the engine movement. LEAD AND CLEARANCE. Too much clearance will detract from the power of an engine, as there is just so much more waste space to be filled with hot steam. Too little clearance will cause pounding. Likewise there will be loss of power in an engine if the lead is too great or too little. The proper amount of lead differs with conditions. A high speed engine requires more than a low speed, and if an engine is adjusted for a certain speed, it should be kept uniformly at that speed, as variation causes loss. The more clearance an engine has the more lead it needs. Also the quicker the valve motion, the less lead required. Sometimes when a large engine is pulling only a light load and there is no chance to shorten the cut-off, a turn of the eccentric disk for a trifle more lead will effect some economy. Cut-off should be as sharp as possible. A slow cut-off in reducing pressure before cut-off is complete, causes a loss of power in the engine. THE EXHAUST. If the exhaust from the cylinder does not begin before the piston begins its return stroke, there will be back pressure due to the slowness with which the valve opens. The exhaust should be earlier in proportion to the slowness of the valve motion, and also, in proportion to the speed of the engine, since the higher the speed the less time there is for the steam to get out. It follows that an engine whose exhaust is arranged for a low speed cannot be run at a high speed without causing loss from back pressure. In using steam expansively the relative proportion between the back pressure and the force of the steam is of course greater. So in using steam expansively the back pressure must be at a minimum, and this is especially true in the compound engine. So many things affect this, that it becomes one of the reasons why it is hard to use a compound engine with as great economy as theory would indicate. Another thing, the smallness of the exhaust nozzle in the smokestack affects the back pressure. The smaller the nozzle, the greater the draft a given amount of steam will create; but the more back pressure there will be, due to the inability of the exhaust steam to get out easily. So the exhaust nozzle should be as large as circumstances will permit. It is a favorite trick with engineers testing the pulling power of their engines to remove the exhaust nozzle entirely for a few minutes when the fire is up. The back pressure saved will at once show in the pulling power of the engine, and every one will be surprised. Of course the fire couldn’t be kept going long without the nozzle on. We have already pointed out that a natural draft is better than a forced one. Here is another reason for it. LEAKS. Leaks always cause a waste of power. They may usually be seen when about the boiler; but leaks in the piston and valve will often go unnoticed. It is to be observed that if a valve does not travel a short distance beyond the end of its seat, it will wear the part it does travel on, while the remaining part will not wear and will become a shoulder. Such a shoulder will nearly always cause a leak in the valve, and besides will add the friction, and otherwise destroy the economy of the engine. Likewise the piston will wear part of the cylinder and leave a shoulder at either end if it does not pass entirely beyond the steam-tight portion of the inside of the cylinder. That it may always do this and yet leave sufficient clearance, the counterbore has been devised. All good engines are bored larger at each end so that the piston will pass beyond the steam-tight portion a trifle at the end of each stroke. Of course it must not pass far enough to allow any steam to get through. Self-setting piston rings are now generally used. They are kept in place by their own tension. There will always be a little leakage at the lap. The best lap is probably a broken joint rather than a diagonal one. Moreover, as the rings wear they will have a tendency to get loose unless they are thickest at a point just opposite to the lap, since this is the point at which it is necessary to make up for the tension lost by the lapping. CHAPTER XII. DIFFERENT TYPES OF ENGINES. STATIONARY. So far we have described and referred exclusively to the usual form of the farm traction engine, which is nearly always the simplest kind of an engine, except in one particular, namely, the reverse which gives a variable cut-off. Stationary engines, however, are worked under such conditions that various changes in the arrangement may be made which gives economy in operating, or other desirable qualities. We will now briefly describe some of the different kinds of stationary engines. [Illustration: D. JUNE & CO.’S STATIONARY FOUR-VALVE ENGINE.] THROTTLING AND AUTOMATIC CUT-OFF TYPES. Engines may be divided into two classes, namely, throttling and automatic cut-off engines. The throttling engine regulates the speed of the engine by cutting off the supply of steam from the boiler, either by the hand of the engineer on the throttle or by a governor working a special throttling governor valve. Railroad locomotives are throttling engines, and moreover they have no governor, the speed being regulated by the engineer at the throttle valve. Traction engines are usually throttling engines provided with a governor. An automatic cut-off engine regulates its speed by a governor connected with the valve, and does it by shortening the time during which steam can enter the cylinder. This is a great advantage, in that the expansive power of steam is given a chance to work, while in the throttling engine steam is merely cut off. The subject has been fully discussed under “Economy in Running a Farm Engine.” An automatic cut-off engine is much the most economical. While on traction engines the governor is usually of the ball variety, on stationary engines improved forms of governors are also placed in the fly wheel, and work in various ways, according to the requirements of the valve gear. THE CORLISS ENGINE. The Corliss engine is a type now well known and made by many different manufacturers. It is considered one of the most economical stationary engines made, but cannot be used for traction purposes. It may be compound, and may be used with a condenser. It cannot be used as a high speed engine, since the valves will not work rapidly enough. The peculiarity of a Corliss engine is the arrangement of the valves. It has four valves instead of one, and they are of the semi-rotary type. They consist of a small, long cylinder which rocks back and forth, so as to close and open the port, which is rather wide and short compared to other types. There is a valve at each end of the cylinder opening usually into the clearance space, to admit steam; and two more valves below the cylinder for the exhaust. These exhaust valves allow any water of condensation to run out of the cylinder. Moreover, as the steam when it leaves the cylinder is much colder than when it enters, the exhaust always cools the steam ports, and when the same ports are used for exhaust and admission the fresh steam has to pass through ports that have been cooled and cause condensation. In the Corliss engine the exhaust does not have an opportunity to cool the live steam ports and the condensation is reduced. This works considerable economy. Also the Corliss valves have little friction from steam pressure on their own backs, since the moment they are lifted from their seats they work freely. The valves are controlled by a governor so as to make the automatic cut-off engine. The Corliss type of frame for engine is often used on traction engines and means the use of convex shoes on cross-head and concave ways or guides. In locomotive type, cross-head slides in four square angle guides. THE HIGH SPEED ENGINE. A high speed engine means one in which the speed of the piston back and forth is high, rather than the speed of rotation, there being sometimes a difference. High speed engines came into use because of the need of such to run dynamos for electric lighting. Without a high speed engine an intermediate gear would have to be used, so as to increase the speed of the operating shaft. In the high speed engine this is done away with. As an engine’s power varies directly as its speed as well as its cylinder capacity or size, an engine commonly used for ten horsepower would become a twenty horsepower engine if the speed could be doubled. So high speed engines are very small and compact, and require less metal to build them. Therefore they should be much cheaper per horsepower. A high speed engine differs from a low speed in no essential particular, except the adjustment of parts. A high steam pressure must be used; a long, narrow valve port is used, so that the full steam pressure may be let on quickly at the beginning of the stroke when the piston is reversing its motion and needs power to get started quickly on its return; the slide valve must be used, since the semi-rotary Corliss would be too wide and short for a quick opening. Some high speed engines are built which use four valves, as does the Corliss. The friction of the slide valve is usually “balanced” in some way, either by “pressure plates” above the valve, which prevent the steam from getting at the top and pressing the valve down, or by letting the steam under the valve, making it slide on narrow strips, since the pressure above would then be reduced in proportion with the smallness of the bearing surface below, and if the bearing surface were very small the pressure above would be correspondingly small, perhaps only enough to keep the valve in place. Some automatic cut-off gear is almost always used. A high speed engine may attain 900 revolutions per minute, 600 being common. In many ways it is economical. CONDENSING AND NON-CONDENSING. In the traction engine the exhaust is used in the smokestack to help the draft, since the smokestack must necessarily be short. A stationary engine is usually provided with a boiler set in brickwork, and a furnace with a high chimney, which creates all the draft needed. In other words, the heated gases wasted in a traction engine are utilized to make the draft. It then becomes desirable to save the power in the exhaust steam in some way. Some of this can be used to heat the feed water, but only a fraction of it. Now when the exhaust steam issues into the air it must overcome the pressure of the atmosphere, nearly 15 lbs. to the square inch, which is a large item to begin with. This can be saved by letting the steam exhaust into a condenser, where a spray of cold water or the like suddenly condenses the steam so that a vacuum is created. There is then no back pressure on the exhaust steam, theoretically. Practically a perfect vacuum cannot be created, and there is a back pressure of 2 or 3 lbs. per square inch. By the use of a condenser a back pressure of about 12 lbs. is taken off the head of the piston on its return stroke, a matter of considerable economy. But an immense amount of water is required to run a condenser, namely, 20 times as much for a given saving of power as is required in a boiler to make that power. So condensers are used only where water is cheap. COMPOUND AND CROSS-COMPOUND. We have already explained the economy effected by the compound engine, in which a large low pressure cylinder is operated by the exhaust from a small high pressure cylinder. In the cut used for illustration the low pressure cylinder is in direct line with the high pressure cylinder, and one piston rod connects both pistons. This arrangement is called the “tandem.” Sometimes the low pressure cylinder is placed by the side of the high pressure, or at a distance from it, and operates another piston and connecting rod. By using a steam chest to store the exhaust steam and varying the cut-off of the two cylinders, the crank of the low pressure may be at an angle of 90 degrees with the crank of the high pressure, and there can be no dead center. [Illustration: THE WOOLF COMPOUND.] When a very high pressure of steam is used the exhaust from the low pressure cylinder may be used to operate a third cylinder; and the exhaust from that to operate a fourth. Engines so arranged are termed triple and quadruple expansion engines, or multiple expansion. The practical saving of a compound engine when its value can be utilized to the full is 10 per cent to 20 per cent. Small engines are seldom compounded, large engines nearly always. CHAPTER XIII. GAS AND GASOLINE ENGINES. The gas and gasoline engines (they are exactly the same except that one generates the gas it needs from gasoline, while the other takes common illuminating gas, the use of gas or gasoline being interchangeable on the same engine by readjustment of some of the parts) are operated on a principle entirely different from steam. While they are arranged very much as a steam engine, the power is given by an explosion of gas mixed with air in the cylinder. Instead of being a steady pressure like that furnished by steam, it is a sudden pressure given to one end of the piston usually once in four strokes or two revolutions, one stroke being required to draw the gasoline in, the second to compress it, the third to receive the effect of the explosion (this is the only power stroke), the fourth to push out the burned gases preparatory to admitting a new charge. The fact that force is given the cylinder at such wide intervals makes it necessary to have an extra heavy flywheel to keep the engine steady, and the double cylinder engine which can give a stroke at least every revolution is still better and is indispensable when the flywheel cannot be above a certain weight. For small horsepowers, such as are required for pumping, feed grinding, churning, etc., the gas engine is so much more convenient and so very much cheaper in operation than the small steam engine that it is safe to say that within a very few years the gas engine will have completely displaced the small steam engine. In fact, the discovery of the gas engine permits the same economies for the small engine that the progress in steam engineering has made possible for the large steam engine. As yet the gas engine has made little or no progress against the large steam plant, with its Corliss engine, its triple expansion, its condenser, and all the other appliances which are not practicable with the small engine. COMPARISON OF STEAM AND GAS ENGINES. The following points prepared by an experienced farm engine manufacturer will show clearly the advantages of the gas engine over the steam engine for general use about a farm: In the first place, the farmer uses power, as a rule, at short intervals, and also uses small power. Should he install a steam engine and wish power for an hour or two, it would be necessary for him to start a fire under the boiler and get up steam before he could start the engine. This would take at least an hour. At the end of the run he would have a good fire and good steam pressure, but no use for it, and would have to let the fire die out and the pressure run down. This involves a great waste of water, time and fuel. With a gasoline engine he is always ready and can start to work within a few minutes after he makes up his mind to do so, and he does not have to anticipate his wants in the power line for half a day. Aside from this, in some states, notably Ohio, the law compels any person operating an engine above ten horsepower to carry a steam engineer’s license. This does not apply to a gasoline engine. Again, the gasoline engine is as portable as a traction engine, and can be applied to all the uses of a traction engine and to general farm use all the rest of the year. At little expense it can be fitted up to hoist hay, to pump water, to husk and shell corn, to saw wood, and even by recent inventions to plowing. It is as good about a farm as an extra man and a team of horses. A gasoline engine can be run on a pint of gasoline per hour for each horsepower, and as soon as the work is done there is no more consumption of fuel and the engine can be left without fear, except for draining off the water in the water jacket in cold weather. A steam engine for farm use would require at least four pounds of coal per horsepower per hour, and in the majority of cases it would be twice that, taking into consideration the amount of fuel necessary to start the fire and that left unburned after the farmer is through with his power. If you know the cost of crude gasoline at your point and the cost of coal, you can easily figure the exact economy of a gasoline engine for your use. To the economy of fuel question may be added the labor or cost of pumping or hauling water. The only point wherein a farmer might find it advantageous to have a steam plant would be where he is running a dairy and wished steam and hot water for cleansing his creamery machinery. This can be largely overcome by using the water from the jackets which can be kept at a temperature of about 175 degrees, and if a higher temperature is needed he can heat it with the exhaust from the engine. The time will certainly come soon when no farmer will consider himself up to date until he has a gasoline engine. Some persons unaccustomed to gasoline may wonder if a gasoline engine is as safe as a steam engine. The fact is, they are very much safer, and do not require a skilled engineer to run them. The gasoline tank is usually placed outside the building, where the danger from an explosion is reduced to a minimum. The only danger that may be encountered is in starting the engine, filling the supply tank when a burner near at hand is in flame, etc. Once a gasoline engine is started and is supplied with gasoline, it may be left entirely alone without care for hours at a time without danger and without adjustment. With a steam engine there is always danger, unless a highly skilled man is watching the engine every moment. If the water gets a little low he is liable to have an explosion; if it gets a little too high he may knock out a cylinder head in his engine; the fire must be fed every few minutes; the grates cleaned. There is always something to be done about a steam engine. So here is another point of great saving in a gasoline engine, namely, the saving of one man’s time. The man who runs the gasoline engine may give nearly all his time to other work, such as feeding a corn-sheller, a fodder chopper, or the like. Kerosene may also be used in the same way with a special type of gas engine. The amounts of fuel required of the different kinds possible in a gas engine are compared as follows by Roper: Illuminating gas, 17 to 20 cubic feet per horsepower per hour. Pittsburg natural gas, as low as 11 cubic feet. 74° gasoline, known as stove gasoline, one-tenth of a gallon. Refined petroleum, one-tenth of a gallon. If a gas producing plant using coal supplies the gas, one pound of coal per horsepower per hour is sufficient on a large engine. DESCRIPTION OF THE GAS OR GASOLINE ENGINE. The gas engine consists of a cylinder and piston, piston rod, cross-head, connecting rod, crank and flywheel, very similar to those used in the steam engine. There is a gas valve, an exhaust valve, and in connection with the gas valve a self-acting air valve. The gas valve and the exhaust valve are operated by lever arm or cam worked from the main shaft, arranged by spiral gear or the like so that it gets one movement for each two revolutions of the main shaft. Such an engine is called “four cycle” (meaning one power stroke to each four strokes of the piston), and works as follows: As the piston moves forward the air and fuel valves are simultaneously opened and closed, starting to open just as the piston starts forward and closing just as the piston completes its forward stroke. Gas and air are simultaneously sucked into the cylinder, by this movement. As the cylinder returns it compresses the charge taken in during the forward stroke until it again reaches back center. The mixture in the Otto engine is compressed to about 70 pounds per square inch. Ignition then takes place, causing the mixture to explode and giving the force from which the power is derived. As the crank again reaches its forward center the piston uncovers a port which allows the greater part of the burnt gases to escape. As the piston comes back, the exhaust valve is opened, enabling the piston to sweep out the remainder of the burnt gases. By the time the crank is on the back center the exhaust valve is closed and the engine is ready to take another charge, having completed two revolutions or four strokes. The side shaft which performs the functions of opening and closing the valves, getting its motion in the Columbus engine by a pair of spiral gears, makes but one revolution to two of the crank shaft. [Illustration: FAIRBANKS, MORSE & CO.’S GASOLINE ENGINE. A is engine cylinder. H is gasoline supply tank located outside of building and under ground. I is air-suction pipe. E is gasoline pump. O is suction pipe from gasoline tank. N is pipe from pump E leading to reservoir P. Q is igniter tube. R is chimney surrounding tube. T is tank supplying Bunsen burner for heating tube.] Gas engines are governed in various ways. One method is to attach a ball governor similar to the Waters on the steam engine. When the speed is too high, the balls go out, and a valve is closed or partly closed, cutting off the fuel supply. Since the engine takes in fuel only once in four strokes, the governing cannot be so close as on the steam engine, since longer time must elapse before the governor can act. Another type of governor operates by opening the exhaust port and holding it open. The piston then merely draws in air through the exhaust port, but no gas. This is called the “hit or miss” governing type. One power stroke is missed completely. The heat caused by the explosion within the cylinder is very great, some say as high as 3,000 degrees. Such a heat would soon destroy the oil used to lubricate the cylinder and make the piston cut, as well as destroying the piston packing. To keep this heat down the cylinder is provided with a water jacket, and a current of water is kept circulating around it to cool it off. When gas is used, the gas is passed through a rubber bag, which helps to make the supply even. It is admitted to the engine by a valve similar to the throttle valve on an engine. Gasoline is turned on by a similar valve, or throttle. It does not have to be gasefied, but is sucked into the cylinder in the form of a spray. As soon as the engine is started, the high heat of the cylinder caused by the constant explosions readily turns the gasoline to gas as it enters. The supply tank of gasoline is placed outside the building, or at a distance, and stands at a point below the feed. A small pump pumps it up to a small box or feed tank, which has an overflow pipe to conduct any superfluous gasoline back to the supply tank. In the gasoline box or feed tank a conical-shaped basin is filled with gasoline to a certain height, which can be regulated. Whatever this conical basin contains is sucked into the cylinder with the air. By regulating the amount in the basin the supply of gasoline in the cylinder can be regulated to the amount required for any given amount of work. In the Columbus engine this regulation is accomplished by screwing the overflow regulator up or down. There are two methods of igniting the charge in the cylinder in order to explode it. One is by what is called a gasoline or gas torch. A hollow pin or pipe is fixed in the top of the cylinder. The upper part of this pin or pipe runs up into a gasoline or gas lamp of the Bunsen type where it is heated red hot. When the gas and air in the cylinder are compressed by the back stroke of the piston, some of the mixture is forced up into this pipe or tube until it comes in contact with the heated portion and is exploded, together with the rest of the charge in the cylinder. Of course this tube becomes filled with burnt gases which must be compressed before the explosive mixture can reach the heated portion, and no explosion is theoretically possible until the piston causes compression to the full capacity of the cylinder. The length of the tube must therefore be nicely regulated to the requirements of the particular engine used. The other method is by an electric spark from a battery. Two electrodes of platinum or some similar substance are placed in the compression end of the cylinder. The spark might be caused by bringing the electrodes sufficiently near together at just the right moment, but the more practical and usual way is to break the current, closing it sharply by means of a lever worked by the gearing at just the moment the piston is ready to return after compressing the charge. The electric spark is by long odds the most desirable method of ignition, being safer and easier to take care of, but it requires some knowledge of electricity and electric connection to keep it always in working order. OPERATION OF GAS AND GASOLINE ENGINES. To all intents and purposes the operation of a gas or gasoline engine is the same as that of a steam engine with the care of the boiler eliminated. The care of the engine itself is practically the same, though the bearings are relatively larger in a gasoline or gas engine and do not require adjustment so often. Some manufacturers will tell you that a gas engine requires no attention at all. Any one who went on that theory would soon ruin his engine. To keep a gasoline engine in working order so as to get the best service from it and make it last as long as possible, you should give it the best of care. An engine of this kind needs just as much oiling and cleaning as a steam engine. All bearings must be lubricated and kept free from dirt, great care must be taken that the piston and cylinder are well lubricated. In addition, the engineer must see that the valves all work perfectly tight, and when they leak in any way they must be taken out and cleaned. Usually the valve seats are cast separate from the cylinder, so that they can be removed and ground when they have worn. Also the water jacket must be kept in order so that the cylinder cannot become too hot. STARTING A GASOLINE ENGINE. It is something of a trick to get a gasoline or gas engine started--especially a gasoline engine--and some skill must be developed in this or there will be trouble. This arises from the fact that when an engine has not been running the cylinder is cold and does not readily gasefy the gasoline. At best only a part of a charge of gasoline can be gasefied, and if the cylinder is very cold indeed the charge will not explode at all till the cylinder is warmed up. When preparing to start an engine, first see that the nuts or studs holding cylinder head to cylinder are tight, as the heating and cooling of the cylinder are liable to loosen them. Then oil all bearings with a hand oil can, and carefully wipe off all outside grease. When all is ready, work the gasoline pump to get the air out of the feed pipes and fill the reservoir. First, the engine must be turned so that the piston is as far back as it will go, and to prevent air being pressed back the exhaust must be held open, or a cock in priming cup on top of cylinder opened. If gasoline priming is needed, the gasoline must be poured into the priming cup after closing the cock into the cylinder, for it would do no good to merely let the gasoline run down into the cylinder in a cold stream: it must be sprayed in. If the exhaust has been held open, and the priming charge of gasoline is to be drawn in through the regular supply pipe and valve, the exhaust should be closed and the throttle turned on to a point indicated by the manufacturer of the engine. We suppose that the igniter is ready to work. If the hot tube is used, the tube should be hot; if the electric igniter is used, the igniter bar should be in position to be snapped so as to close the circuit and cause a spark when the charge has been compressed. If all is ready, open the cock from which the supply of gasoline is to be obtained, and at the same time turn the engine over so as to draw the charge into the cylinder. If a priming cock has been opened, that must be closed by hand as soon as the cylinder is filled and the piston ready to return for compression. If the regular feed is used, the automatic valve will close of itself. Bring the flywheel over to back center so that piston will compress the charge. With the flywheel in the hand, bring the piston back sharply two or three times, compressing the charge. This repeated compression causes a little heat to be liberated, which warms up the cylinder inside. If the cylinder is very cold this compression may be repeated until the cylinder is sufficiently warm to ignite. When performing this preparatory compression the piston may be brought nearly up to the dead center but not quite. At last bring it over the dead center, and just as it passes over, snap the electric ignition bar. If an explosion follows the engine will be started. If the hot tube is used, the flywheel may be brought around sharply each time so that the piston will pass the dead center, as an explosion will follow complete compression. If the explosion does not follow, the flywheel may be turned back again and brought up sharply past the dead center. Each successive compression will warm up the cylinder a little till at last an explosion will take place and the engine will be started. More gasoline will be needed to start in cold weather than in warm, and the starting supply should be regulated accordingly. Moreover, when the engine gets to going, the cylinder will warm up, more of the gasoline will vaporize, and a smaller supply will be needed. Then the throttle can be turned so as to reduce the supply. After the engine is started, the water jacket should be set in operation, and you should see that the cylinder lubrication is taking place as it ought. As the above method of starting the engine will not always work well, especially in cold weather, what are called “self-starters” are used. They are variously arranged on different engines, but are constructed on the same general principle. This is, first, to pump air and gasoline into the cylinder instead of drawing it in by suction. Sometimes the gasoline is forced in by an air compression tank. The engine is turned just past the back center, care having been taken to make sure that the stroke is the regular explosion stroke. This may be told by looking at the valve cam or shaft. If an electric igniter is used, it is set ready to snap by hand. If the tube igniter is used, a detonator is arranged in the cylinder, to be charged by the head of a snapping parlor match which can be exploded by hand. Holding the flywheel with one hand with piston just past back center, fill the compressed end of the cylinder by working the pump or turning on the air in compression tank till you feel a strong pressure on the piston through the flywheel. Then snap igniter or detonator and the engine is off. If throttle valve has not been opened, it may now be immediately opened. The skill comes in managing the flywheel with one hand, or one hand and a foot, and the igniter, etc., with the other hand. Care must be exercised not to get caught when the flywheel starts off. The foot must never be put through the arm of the wheel, the wheel merely being held when necessary by the ball of the big toe, so that if the flywheel should start suddenly it would merely slip off the toe without carrying the foot around or unbalancing the engineer. Until one gets used to it, it is better to have some one else manage the flywheel, while you look after the gasoline supply, igniter, etc. When used to it, one man can easily start any gasoline engine up to 15 horsepower. WHAT TO DO WITH A GASOLINE ENGINE WHEN IT DOESN’T WORK. Questions and Answers. Q. If the engine suddenly stops, what would you do? A. First, see that the gasoline feed is all right, plenty of gasoline in the tank, feed pipe filled, gasoline pump working, and then if valves are all in working order. Perhaps there may be dirt in the feed reservoir, or the pipe leading from it may be stopped up. If everything is right so far, examine the valves to see that they work freely and do not get stuck from lack of good oil, or from use of poor oil. Raise them a few times to see if they work freely. Carefully observe if the air valve is not tight in sleeve of gas valve. Q. What would be the cause of the piston’s sticking in the cylinder? A. Either it was not properly lubricated, or it got too hot, the heat causing it to expand. Q. Are boxes on a gasoline engine likely to get hot? A. Yes, though not so likely as on a steam engine. They must be watched with the same care as they would be on a steam engine. If the engine stops, turn it by hand a few times to see that it works freely without sticking anywhere. Q. Is the electric sparking device likely to get out of order? A. Yes. You can always test it by loosening one wire at the cylinder and touching it to the other to see that a spark passes between them. If there is no spark, there is trouble with the battery. Q. How should the batteries be connected up? A. A wire should pass from carbon of No. 1 to copper of No. 2; from carbon of No. 2 to copper of No. 3, etc., always from copper to carbon, never from carbon to carbon or copper to copper. Wire from last carbon to spark coil and from coil to switch, and from switch to one of the connections on the engine. Wire from copper of No. 1 to the other connection on the engine. In wiring, always scrape the ends of the wire clean and bright where the connection is to be made with any other metal. Q. What precautions can be taken to keep batteries in order? A. The connections between the cells can be changed every few days, No. 1 being connected with No. 3, No. 3 with No. 5, etc., alternating them, but always making a single line of connection from one connection on cylinder to first copper, from the carbon of that cell to copper of next cell, and so on till the circuit to the cylinder is completed. When the engine is not in operation, always throw out the switch, to prevent possible short circuiting. If battery is feeble at first, fasten wires together for half an hour at engine till current gets well started. Q. Is there likely to be trouble with the igniter inside cylinder? A. There may be. You will probably find a plug that can be taken out so as to provide a peep hole. Never put your eye near this hole, for some gasoline may escape and when spark is made it will explode and put out your eye. Always keep the eye a foot away from the hole. Practice looking at the spark when you know it is all right and no gasoline is near, in order that you may get the right position at which to see the spark in case of trouble. In any case, always take pains to force out any possible gas before snapping igniter to see if the spark works all right. Q. If there is no spark, what should be done? A. Clean the platinum points. This may be done by throwing out switch and cutting a piece of pine one-eighth of an inch thick and one-half inch wide, and rubbing it between the points. It may be necessary to push cam out a trifle to compensate for wear. Q. How can you look into peep hole without endangering eyesight? A. By use of a mirror. Q. If the hot tube fails to work, what may be done? A. Conditions of atmosphere, pressure, etc., vary so much that the length of the tube cannot always be determined. If a tube of the usual length fails to work, try one a little longer or shorter, but not varying over 1½ inches. Q. When gas is used, what may interfere with gas supply? A. Water in the gas pipes. This is always true of gas pipes not properly drained, especially in cold weather when condensation may take place. If water accumulates, tubes must be taken apart and blown out, and if necessary a drain cock can be put in at the lowest point. Q. What trouble is likely to be had with the valves? A. In time the seats will wear, and must be taken out and ground with flour or emery. Q. Should the cylinder of a gasoline engine be kept as cool as it can be kept with running water? A. No. It should be as hot as the hand can be borne upon it, or about 100 degrees. If it is kept cooler than this the gasoline will not gasefy well. If a tank is used, the circulation in the tank will justify the temperature properly. The water may be kept at 175 degrees of temperature, and used for hot water heating. The exhaust gases are also hot and may be used for heating by carrying in pipes coiled in a hot water heater. Q. Are water joints likely to leak? A. Yes. The great heating given the cylinder is liable to loosen the water joints. They are best packed with asbestos soaked in oil, sheets 1-16 inch thick. Old packing should always be thoroughly cleaned off when new packing is put in. Q. How may the bearings be readjusted when worn? A. Usually there are liners to adjust bearing. In crank box adjust as in steam engine by tightening the key. Q. If you hear a loud explosion in the exhaust pipe after the regular explosion, should you be alarmed? A. No. All gas or gasoline engines give them at times and they are harmless. If the gas or gasoline fed to the engine is not sufficient to make an explosive mixture, the engine will perhaps miss the explosion, and live gas will go into the exhaust pipe. After two or three of these have accumulated an explosion may take place and the burned gases coming out of the port as hot flames will explode the live gas previously exhausted. Any missing of the regular explosion by the engine, through trouble with battery, or the like, will cause the same condition. Q. When you get exhaust pipe explosions, what should you do? A. Turn on the fuel till the exhaust is smoky. Then you know you have fuel enough and more than enough. If the explosions still continue, conclude that the igniter spark is too weak, or does not take place. Q. What precaution must be taken in cold weather? A. The water must be carefully drained out of jacket. Q. Will common steam engine cylinder oil do for a gasoline engine? A. No. The heat is so great that only a special high grade mineral oil will do. Any oil containing animal fat will be worse than useless. Q. How can you tell if right amount of gas or gasoline is being fed to engine to give highest power? A. Turn on as much as possible without producing smoke. A smokeless mixture is better than one which causes smoke. Q. If you have reason to suppose gas may be in the cylinder, should you try to start cylinder? A. No. Empty the gas all out by turning the engine over a few times by hand, holding exhaust open if necessary. Q. How long will a battery run without recharging? A. The time varies. Usually not over three or four months. Q. Is it objectionable to connect an electric bell with an engine battery? A. Certainly. Never do it. Q. If your engine doesn’t run, how many things are likely to be the trouble? A. Not more than four--compression, spark, gas supply, valves. CHAPTER XIV. HOW TO RUN A THRESHING MACHINE. A threshing machine, though large, is a comparatively simple machine, consisting of a cylinder with teeth working into other teeth which are usually concaved (this primary part really separates the grain from the husk), and rotary fan and sieves to separate grain from chaff, and some sort of stacker to carry off the straw. The common stacker merely carries off the straw by some endless arrangement of slats working in a long box; while the so-called “wind stacker” is a pneumatic device for blowing the straw through a large pipe. It has the advantage of keeping the straw under more perfect control than the common stacker. The separation of the grain from the straw is variously effected by different manufacturers, there being three general types, called apron, vibrating, and agitating. The following list of parts packed inside the J. I. Case separator (of the agitative type) when it is shipped will be useful for reference in connection with any type of separator: 2 Hopper arms, Right and Left, 1 Hopper bottom, 1 Hopper rod with thumb nut, 2 Feed tables, 2 Feed table legs, 2 Band cutter stands and bolts, 1 Large crank shaft, 1 Grain auger with 1223 T. pulley and 1154 T., Box, 1 Tailings auger, 1 Elevator spout, 1 Elevator shake arm, complete, 1 Set fish-backs, for straw-rack, 1 Elevator pulley, 529 T., 1 Beater pulley, 6-inch 1254 T., or 4-inch 1255 T., 1 Elevator drive pulley 1673 T., 1 Crank pulley to drive grain auger 1605 T., 1 Cylinder pulley to drive crank 4-inch 973 T., or 6-inch 1085 T., 1 Cylinder pulley to drive fan 1347 T., 1348 T., or 1633 T., 1 Fan pulley, 1244 T., or 1231 T., 1 Belt tightener, complete, with pulley, 1 Belt reel, 5016 T., or 1642 T., with crank and bolt, 4 Shoe sieves, 4 Shoe rods, with nuts and washers, 1 Conveyor extension, 1 Sheet iron tail board, 2 Tail board castings 1654 T., and 1655 T. In addition to these are the parts of the stacker. As each manufacturer furnishes all needed directions for putting the parts together, we will suppose the separator is in working condition. A new machine should be set up and run for a couple of hours before attempting to thresh any grain. The oil boxes should be carefully cleaned, and all dirt, cinders, and paint removed from the oil holes. The grease cups on cylinder, beater and crank boxes should be screwed down after being filled with hard oil, moderately thin oil being used for other parts of the machine. Before putting on the belts, turn the machine by hand a few times to see that no parts are loose. Look into the machine on straw rack and conveyor. First connect up belt with engine and run the cylinder only for a time. Screw down the grease cup lugs when necessary, and see that no boxes heat. Take off the tightener pulley, clean out oil chambers and thoroughly oil the spindle. Then oil each separate bearing in turn, seeing that oil hole is clean, and that pulley or journal works freely. The successive belts may then be put on one at a time, until the stacker belt is put on after its pulleys have been oiled. Especially note which belts are to run crossed--usually the main belt and the stacker belt. You can tell by noting which way the machinery must run to keep the straw moving in the proper direction. Oiling on the first run of a machine is especially important, as the bearings are a trifle rough and more liable to heat than after machine has been used for some time. It is well to oil a shaft while it runs, since the motion helps the oil to work in over the whole surface. The sieves, concaves, check board and blinds must be adjusted to the kind of grain to be threshed. When they have been so adjusted the machine is ready to thresh. SETTING SEPARATOR. It is important that the machine be kept perfectly steady, and that it be level from side to side, though its being a little higher or lower at one end or the other may not matter much. If the level sidewise is not perfect the grain will have a tendency to work over to one side. A spirit level should be used. [Illustration: SECTIONAL VIEW OF THE AGITATOR SEPARATOR.] One or more of the wheels should be set in holes, according to the unevenness of the ground, and the rear wheels should be well blocked. Get the holes ready, judging as well as possible what will give a true level and a convenient position. Haul the machine into position and see that it is all right before uncoupling the engine. If holes need redigging to secure proper level, machine may be pulled out and backed in again by the engine. When machine is high in front it can easily be leveled when engine or team have been removed, by cramping the front wheels and digging in front of one and behind the other, then pulling the tongue around square. Block the right hind wheel to prevent the belt drawing machine forward. Always carry a suitable block to have one handy. In starting out of holes or on soft ground, cramp the front axle around, and it will require only half the power to start that would be required by a straight pull. In setting the machine, if the position can be chosen, choose one in which the straw will move in the general direction of the wind, but a little quartering, so that dust and smoke from engine will be carried away from the men and the straw stack. In this position there is less danger from fire when wood is used. THE CYLINDER. The cylinder is arranged with several rows of teeth working into stationary teeth in what is called the concave. It is important that all these teeth be kept tight, and that the cylinder should not work from side to side. The teeth are liable to get loose in a new machine, and should be tightened up frequently. A little brine on each nut will cause it to rust slightly and help to hold it in place. If the cylinder slips endwise even a sixteenth of an inch, the teeth will be so much nearer the concaves on one side and so much farther away from them on the other side. Where they are close, they will crack the grain; where they are wide apart they will let the straw go through without threshing or taking out the grain. So it is important that the cylinder and its teeth run true and steady. If the teeth get bent in any way, they must be straightened. The speed of the cylinder is important, since its pulley gives motion to the other parts of the machine, and this movement must be up to a certain point to do the work well. A usual speed for the cylinder pulley is 1,075 revolutions per minute, up to 1,150. There is always an arrangement for adjusting the cylinder endwise, so that teeth will come in the middle. This should be adjusted carefully when necessary. The end play to avoid heating may be about 1-64 of an inch. It may be remembered that the cylinder teeth carry the straw to the concaves, and the concaves do the threshing. THE CONCAVES. The concaves are to be adjusted to suit the kind of grain threshed. When desiring to adjust concaves, lift them up a few times and drop so as to jar out dust. Wedging a block of wood between cylinder teeth and concaves will in some types of separator serve to bring up concaves when cylinder is slowly turned by hand. There are from two to six rows of teeth in the concave, and usually the number of rows is adjustable or variable. Two rows will thresh oats, where six are required for flax and timothy. Four rows are commonly used for wheat and barley. The arrangement of rows of teeth and blanks is important. When four rows are used, one is commonly placed well back, one front, blank in the middle. When straw is dry and brittle, cylinder can be given “draw” by placing blank in front. Always use as few teeth and leave them as low as possible to thresh clean, since with more teeth than necessary set higher than required the straw will be cut up and a great deal of chopped straw will get into the sieves, all of which also requires additional power. Sometimes the teeth can be taken out of one row, so that one, three, or five rows may be used. For especially difficult grain like Turkey wheat, a concave with corrugated teeth may be used, in sets of three rows each up to nine rows. The corrugated teeth are used for alfalfa in localities where much is raised. THE BEATER AND CHECK BOARD. After the cylinder has loosened the grain from the husk and straw, it must still be separated. Some threshers have a grate under the cylinder and behind it. In any case the beater causes the heavy grain to work toward the bottom, and the check board keeps the grain from being carried to rear on top of the straw, where it would not have a chance to become separated. If the grain is very heavy or damp, there may be a tendency for the straw to stick to the cylinder and be carried around too far. In such a case the beater should be adjusted to give more space, and the check board raised to allow the straw to pass to the rear freely. STRAW RACK. The straw rack and conveyor carry the straw and grain to the rear with a vibratory movement, causing the grain to be shaken out. To do good work the straw rack must move with a sufficient number of vibrations per minute, say 230. A speed indicator on the crank shaft will show the number of vibrations best. Great care must be taken with this part of the thresher, or a great deal of grain will be carried into the straw. The less the straw is cut up, the better this portion of the machine works; so the smallest practicable number of teeth in the concave should be used. The crank boxes and pitmans should be adjusted so that there is no pounding. If the rear vibrating arms drop too low they get below the dead center and are liable to break, at any rate causing severe pounding and hard running. To prevent this, the crank boxes can be moved forward by putting leather between them and the posts, or should be otherwise adjusted. The trouble being due to the pitmans having worn short, the pitmans may be lengthened in some way by putting pieces of leather over the end or the like, or new pitmans may be introduced. THE FAN. The chief difficulty likely to arise with the fan is blowing over grain. To prevent this blinds are usually arranged, which may be adjusted while the machine is running so as to prevent the grain from being blown over. At the same time it is important to clean the grain, so the adjustment should not go to one extreme or the other. In windy weather the blinds should be closed more on one side than on the other. The speed of the fan must be adjusted to the requirements of the locality. As much blast should be used as the grain will stand, and heavy feeding requires more wind than light feeding, since the chaff checks the blast to a certain extent. Care should be taken that the wind board over the grain auger does not get bent, and it should be adjusted so that the strongest part of the blast will come about the middle of the sieve. SIEVES. There is usually one conveyor sieve, which causes the grain to move along, and shoe sieves, which are required to clean the grain thoroughly. Different kinds of sieves are provided for different kinds of grain, and the proper selection and adjustment of these sieves as to mesh, etc., is of the utmost importance. Much depends on the way the sieves are set, and on the rate at which the thresher is fed, or the amount of work it is really doing. The best guide is close observation and experience, both your own and that of other threshermen. CONVEYOR EXTENSION. This carries the coarse chaff from the conveyor sieve to the stacker. The conveyor sieve should be coarse enough to let all the good grain through, as whatever is carried on to the extension must be returned with the tailings to the cylinder. This means so much waste work. The conveyor extension is removable, and should always be tight before machine is started. See that it is. When necessary, the grain may be run over a screen, which differs from a sieve in that the mesh is small and intended to let dust and small chaff through while the grain does not pass. The refuse from the screen is dropped onto the ground. All screens have a tendency to become clogged, and in this condition obstruct the grain and wind. It is desirable not to use them except when necessary, and if used they should be frequently cleaned. TAILINGS ELEVATOR. The tailings are carried back to the cylinder by an elevator usually worked with a chain. This chain should be kept tight enough not to unhook, yet not so tight as to bind. To put the chain into the elevator, tie a weight on a rope and drop it down the lower part of the elevator. The chain may be fastened to the rope and a man at the top can then pull the chain up, while another feeds it in at the bottom. When chain has been drawn up to the top, the rope should be dropped down upper portion of elevator and used at bottom to pull chain down after it has been adjusted over the sprocket. Some one at the bottom should continue to feed the chain in as it is pulled down, so that it will go into the elevator straight. When the chain has been pulled through it may be hooked and adjusted to lower sprocket, and tightened up by screws at top. Turn the chain around once by hand to make sure there are no kinks in it. The tailings should be small, containing no light chaff and little full-size grain. They are a good indication of how the sieves are working. If much good grain is coming through, see if it gets over the conveyor sieve by way of the extension to the tailings auger, or over the shoe sieve. If the sieves are not right, they may be adjusted in various ways, according to the directions of the manufacturer. Grain returned in the tailings is liable to get cracked in the cylinder, and much chaff in the tailings chokes the cylinder. For every reason, the tailings should be kept as low as possible. SELF-FEEDER. The self-feeder is arranged to cut the bands of the sheaves and feed the grain to the cylinder automatically. It has a governor to prevent crowding in too much grain, and usually a change of pulleys for slow or fast feeding, as circumstances may require. In starting a new governor the friction pulley and inside of the band should have paint scraped off, and a little oil should be put on face of friction wheel. The carrier should not start till the machine attains full threshing motion, and to prevent this a few sheaves should be laid upon it. The knife arms should be raised or lowered to adjust them to the size of the sheaves and condition of the grain for cutting bands. The cranks and carrier shaft boxes should be oiled regularly, but the friction bands should not be oiled after it once becomes smooth. THE WIND STACKER. The wind stacker is arranged to swing by a hand-wheel or the like, and also automatically. Great care should be taken not to use the hand moving apparatus when the stacker is set for automatic moving, as a break is liable to follow. There is a clutch to stop the stacker, however. At times it will be more convenient to leave off the belt that causes the automatic movement. By the use of various pulleys the speed of the stacker may be altered, and it should be run no faster than is necessary to do the work required, which will depend on the character of the straw. Any extra speed used will add to the cost of running the engine and is a loss in economy. In moving machine with wind stacker in place, care should be taken to see that it rests in its support before machine moves. The canvas curtain under the decking, used to turn the straw into the hopper, may need a piece of wood fastened to its lower edge to keep it more stiff when stiff rye straw is passing. The bearings of the fan and jack shafts should be kept well lubricated with hard oil, and the bevel gears should be kept well greased with axle grease applied with a stick. Other bearings and worm gear of automatic device should be oiled with soft oil. The attached stacker is simple in operation, and if it is desired not to use the automatic swinging device but swing by hand, the automatic gear may be thrown out. An independent stacker is managed in much the same way. ATTACHMENTS. A weigher, bagger, and a high loader are usually used with a separator. Their operation is simple, and depends upon the particular type or make. BELTING. The care of the belting is one of the most important things about the management of a threshing machine, and success or failure will depend largely on the condition in which the belts are kept. Of course the hair side should be run next the band wheel. Once there was disagreement among engineers on this point, but it has been conclusively proven that belts wear longer this way and get better friction, for the simple reason that the flesh side is more flexible than the hair side, and when on the outside better accommodates itself to the shape of the pulley. If the hair side is outermost, it will be stretched more or less in going around the pulley and in time will crack. Rubber belts must be run with the seam on the outside. When leather belts become hard they should be softened with neatsfoot oil. A flexible belt is said to transmit considerably more power than a hard one. Pulleys must be kept in line or the belt will slip off. When pulleys are in line the belt has a tendency to work to the tightest point. Hence pulleys are usually made larger in the middle, which is called “crowning.” Belts on a separator should be looked over every day, and when any lacing is worn, it should be renewed at once. This will prevent breaks during working, with loss of time. Some threshermen carry an extra set of belts to be ready in case anything does break, and they assert that they save money by so doing. Lacing is not stronger in proportion as it is heavy. If it is heavy and clumsy it gets strained in going round the pulley, and soon gives out. The ideal way to lace a belt is to make it as nearly like the rest of the belt as possible, so that it will go over the pulleys without a jar. The ends of the belt should be cut off square with a try square, and a small punch used for making holes. Holes should be equally spaced, and outside ones not so near the edge as to tear out. The rule is a hole to every inch of the belt, and in a leather belt they may be as close as a quarter of an inch to the ends without tearing out. Other things being equal, the nearer the ends the holes are the better, as belt will then pass over pulley more easily. The chief danger of tearing is between the holes. A stacker web belt may be laced by turning the ends up and lacing them together flat at right angles to rest of belt. Rubber or cotton belting that does not run over idler or tightener pulleys so that both sides must be smooth may be laced in this way. This lacing lasts two or three times as long with such belts as any other, for the reason that the string is not exposed to wear and there is no straining in passing round pulleys. The ordinary method of lacing a leather belt is to make the laces straight on the pulley side, all running in the same direction as the movement of the belt, and crossing them on the outside diagonally in both directions. When belts run on pulleys on both sides, as they do on the belt driving beater and crank, and also on wind stacker, a hinge lacing may be made by crossing the lacing around the end of the belt to the next adjacent hole opposite, the lacing showing the same on both sides. This allows the belt to bend equally well either way. The best way to fasten a lacing is to punch a hole where the next row of lace holes would come when the belt is cut off, and after passing the lace through this hole, bring the end around and force it through again, cutting the end off short after it has passed through. This hole must be small enough to hold the lace securely, and care should be taken that it is in position to be used as a lace-hole the next time a series of holes is required. New belts stretch a good deal, and the ends of the lacing should not be cut off short till the stretch is taken out of the belts. Belting that has got wet will shrink and lacing must be let out before belt is put on again. Tight belts have been known to break the end of a shaft off, and always cause unnecessary friction. Cotton or Gandy belting should not be punched for lacing, but holes made with a pointed awl, since punching cuts some of the threads and weakens belt. HOW TO BECOME A GOOD FEEDER. The art of becoming a good feeder will not be learned in a day. The bundles should be tipped well up against the cylinder cap, and flat bundles turned on edge, so that cylinder will take them from the top. It is not hard to spread a bundle, and in fast threshing a bundle may be fed on each side, each bundle being kept pretty well to its own side, while the cylinder is kept full the entire width. A good feeder will keep the straw carrier evenly covered with straw, and will watch the stacker, tailings and grain elevator and know the moment anything goes wrong. WASTE. No threshing machine will save every kernel of the grain, but the best results can be attained only by care and judgment in operating. It is easy to exaggerate the loss of grain, for if a very small stream of grain is seen going into the straw it will seem enormous, though it will not amount to a bushel a day. There are practically a million kernels of wheat in a bushel, or 600 handfuls, and even if a handful is wasted every minute, it would not be enough to counterbalance the saving in finishing a job quickly. Of course, waste must be watched, however, and checked if too great. First determine whether the grain is carried over in the straw or the waste is at the shoe sieve. If the waste is in the conveyor sieve, catch a handful of the chaff, and if grain is found, see whether the sieve is the proper mesh. Too high a speed will cause the grain to be carried over. If too many teeth are used in the concave, the conveyor sieve will be forced to carry more chaff than it can handle. The blast may be too strong and carry over grain, so adjust the blinds that the blast will be no stronger than is necessary to clean the wheat well and keep sieves free. If grain is still carried over, the conveyor sieve may be adjusted for more open work, but care should be taken not to overwork the shoe sieve. Be careful that the wind board is not bent so that some grain will go into the fan and be thrown out of the machine altogether. If the grain is not separated from the straw thoroughly, it may be due to “slugging” the cylinder (result of poor feeding), causing a variable motion. It may also be because speed of crank is not high enough. Check board should be adjusted as low as possible to prevent grain being carried on top of straw. See that cylinder and concave teeth are properly adjusted so as not to cut up straw, while at the same time threshing out all the grain. Sometimes heads not threshed out by the cylinder will be threshed out by the fan of the wind stacker, and the fault will be placed on the separating portions instead of on the imperfect cylinder. Grain passes through the cylinder at the rate of about a mile a minute. The beater reduces this to 1,500 feet per minute. After passing the check board the straw moves about 36 feet per minute. At these three different speeds the straw passes the 17 feet length of the machine in about 25 seconds. The problem is to stop the grain while the straw is allowed to pass out. Evidently there must be a small percentage of loss, and there is always a limit as to what it will pay to try to save. Each man must judge for himself. BALANCING A CYLINDER. A cylinder should be so balanced that it will come to rest at any point. In a rough way a cylinder may be balanced by placing the journals on two carpenter’s squares laid on saw-horses. Gently roll the cylinder back and forth and every time it stops, make a chalk mark on the uppermost bar. If the same bar comes up three times in succession it probably is light, and a wedge should be driven under center band at chalk mark. Continue experimenting until cylinder will come to rest at any point. COVERING PULLEYS. This is easily done, but care must be taken that the leathers are tight or they will soon come off. To cover a cylinder pulley, take off what remains of the old cover, pull out the nails, and renew the wedges if necessary. Select a good piece of leather a little wider than face of pulley and about four inches longer than enough to go around. Soak it in water for about an hour. Cut one end square and nail it to the wedges, using nails just long enough to clinch. Put a clamp made of two pieces of wood and two bolts on the leather, block the cylinder to keep it from turning, and by means of two short levers pry over the clamp to stretch the leather. Nail to the next wedges, move the clamp and nail to each in turn, finally nailing to the first one again before cutting off. Trim the edges even with the rim of the pulley. The same method may be used with riveted covers. CARE OF A SEPARATOR. A good separator ought to last ten years, and many have been in use twice that time. After the season is over the machine ought to be thoroughly cleaned and stored in a dry place. Dirt on a machine holds moisture and will ruin a separator during a winter if it is left on. It also causes the wood to rot and sieves and iron work to rust. Once in two years at least a separator ought to have a good coat of first-class coach varnish. Before varnishing, clean off all grease and oil with benzine and see that paint is bright. At the beginning of the season give the machine a thorough overhauling, putting new teeth in cylinder if any are imperfect, and new slats in stacker web or straw rack if they are needed. Worn boxes should be taken up or rebabbitted, and conveyor and shoe eccentrics replaced if worn out. Tighten nuts, replace lost bolts, leaving the nut always turned square with the piece it rests on. Every separator ought to be covered with a canvas during the season. It will pay. The right and left sides of a threshing machine are reckoned from the position of the feeder as he stands facing the machine. In case of fire, the quickest way is to let the engine pull the machine out by the belt. Take blocks away from wheels, place a man at end of tongue to steer, and back engine slowly. If necessary, men should help the wheels to start out of holes or soft places. Watch the forks of the pitchers to see that none are loose on the handles, especially if a self-feeder is used. A pitchfork in a separator is a bad thing. CHAPTER XV. QUESTIONS ASKED ENGINEERS WHEN APPLYING FOR A LICENSE.[7] Footnote 7: Furnished by courtesy of a friend of Aultman & Taylor Co. Q. If you were called on to take charge of a plant, what would be your first duty? A. To ascertain the exact condition of the boiler and all its attachments (safety valve, steam gauge, pump, injector), and engine. Q. How often would you blow off and clean your boilers if you had ordinary water to use? A. Once a month. Q. What steam pressure will be allowed on a boiler 50 inches diameter ⅜ inch thick, 60,000 T. S. 1-6 of tensile strength factor of safety? A. One-sixth of tensile strength of plate multiplied by thickness of plate, divided by one-half of the diameter of boiler, gives safe working pressure. Q. How much heating surface is allowed per horse power by builders of boilers? A. Twelve to fifteen feet for tubular and flue boilers. Q. How do you estimate the strength of a boiler? A. By its diameter and thickness of metal. Q. Which is the better, single or double riveting? A. Double riveting is from sixteen to twenty per cent stronger than single. Q. How much grate surface do boiler makers allow per horse power? A. About two-thirds of a square foot. Q. Of what use is a mud drum on a boiler, if any? A. For collecting all the sediment of the boiler. Q. How often should it be blown out? A. Three or four times a day. Q. Of what use is a steam dome on a boiler? A. For storage of dry steam. Q. What is the object of a safety valve on a boiler? A. To relieve pressure. Q. What is your duty with reference to it? A. To raise it twice a day and see that it is in good order. Q. What is the use of check valve on a boiler? A. To prevent water from returning back into pump or injector which feeds the boiler. Q. Do you think a man-hole in the shell on top of a boiler weakens it any? A. Yes, to a certain extent. Q. What effect has cold water on hot boiler plates? A. It will fracture them. Q. Where should the gauge cock be located? A. The lowest gauge cock ought to be placed about an inch and a half above the top row of flues. Q. How would you have your blow-off located? A. In the bottom of mud-drum or boiler. Q. How would you have your check valve arranged? A. With a stop cock between check and boiler. Q. How many valves are there in a common plunger force pump? A. Two or more--a receiving and a discharge valve. Q. How are they located? A. One on the suction side, the other on the discharge. Q. How do you find the proper size of safety valves for boilers? A. Three square feet of grate surface is allowed for one inch area of spring loaded valves; or two square feet of grate surface to one inch area of common lever valves. Q. Give the reasons why pumps do not work sometimes? A. Leak in suction, leak around the plunger, leaky check valve, or valves out of order, or lift too long. Q. How often ought boilers to be thoroughly examined and tested? A. Twice a year. Q. How would you test them? A. With hammer and with hydrostatic test, using warm water. Q. Describe the single acting plunger pump; how it gets and discharges its water? A. The plunger displaces the air in the water pipe, causing a vacuum which is filled by the atmosphere forcing the water therein; the receiving valve closes and the plunger forces the water out through the discharge valve. Q. What is the most economical boiler-feeder? A. The (Trix) Exhaust Injector.[8] Footnote 8: So says one expert. Others may think otherwise. Q. What economy is there in the Exhaust Injector? A. From 15 to 25 per cent saving in fuel. Q. Where is the best place to enter the boiler with the feed water? A. Below the water level, but so that the cold water can not strike hot plates. If injector is used this is not so material as feed water is always hot. Q. What are the principal causes of priming in boilers? A. To high water, not steam room enough, misconstruction, engine too large for boiler. Q. How do you keep boilers clean or remove scale therefrom? A. The best “scale solvent” and “feed water purifier” is an honest, intelligent engineer who will regularly open up his boilers and clean them thoroughly, soaking boilers in rain water now and then. Q. If you found a thin plate, what would you do? A. Put a patch on it. Q. Would you put it on the inside or outside? A. Inside. Q. Why so? A. Because the action that has weakened the plate will then set on the patch, and when this is worn it can be repeated. Q. If you found several thin places, what would you do? A. Patch each and reduce the pressure. Q. If you found a blistered plate? A. Put a patch on the fire side. Q. If you found a plate on the bottom buckled? A. Put a stay through the center of buckle. Q. If you found several of the plates buckled? A. Stay each and reduce the pressure. Q. What is to be done with a cracked plate? A. Drill a hole at each end of crack, caulk the crack and put a patch over it. Q. How do you change the water in the boiler when the steam is up? A. By putting on more feed and opening the surface blow cock. Q. If the safety valve was stuck how would you relieve the pressure on the boiler if the steam was up and could not make its escape? A. Work the steam off with engine after covering fires heavy with coal or ashes, and when the boiler is sufficiently cool put safety valve in working order. Q. If water in boiler is suffered to get too low, what may be the result? A. Burn top of combustion chamber and tubes, perhaps cause an explosion. Q. If water is allowed to get too high, what result? A. Cause priming, perhaps cause breaking of cylinder covers or heads. Q. What are the principal causes of foaming in boilers? A. Dirty and impure water. Q. How can foaming be stopped? A. Close throttle and keep closed long enough to show true level of water. If that level is sufficiently high, feeding and blowing off will usually suffice to correct the evil. Q. What would you do if you should find your water gone from sight very suddenly? A. Draw the fires and cool off as quickly as possible. Never open or close any outlets of steam when your water is out of sight. Q. What precautions should you take to blow down a part of the water in your boiler while running with a good fire? A. Never leave the blow-off valve, and watch the water level. Q. How much water would you blow off at once while running? A. Never blow off more than one gauge of water at a time while running. Q. What general views have you in regard to boiler explosions--what is the greatest cause? A. Ignorance and neglect are the greatest causes of boiler explosions. Q. What precaution should the engineer take when necessary to stop with heavy fires? A. Close dampers, put on injector or pump and if a bleeder is attached, use it. Q. Where is the proper water level in boilers? A. A safe water level is about two and a half inches over top row of flues. Q. What is an engineer’s first duty on entering the boiler room? A. To ascertain the true water level. Q. When should a boiler be blown out? A. After it is cooled off, never while hot. Q. When laying up a boiler what should be done? A. Clean thoroughly inside and out; remove all oxidation and paint places with red lead; examine all stays and braces to see if any are loose or badly worn. Q. What is the last thing to do at night before leaving plant? A. Look around for greasy waste, hot coals, matches, or anything which could fire the building. Q. What would you do if you had a plant in good working order? A. Keep it so, and let well enough alone. Q. Of what use is the indicator? A. The indicator is used to determine the indicated power developed by an engine, to serve as a guide in setting valves and showing the action of the steam in the cylinder. Q. How would you increase the power of an engine? A. To increase the power of an engine, increase the speed; or get higher pressure of steam, use less expansion. Q. How do you find the horsepower of an engine? A. Multiply the speed of piston in feet per minute by the total effective pressure upon the piston in pounds and divide the product by 33,000. Q. Which has the most friction, a perfectly fitted, or an imperfectly fitted valve or bearing? A. An imperfect one. Q. How hot can you get water under atmospheric pressure with exhaust steam? A. 212 degrees. Q. Does pressure have any influence on the boiling point? A. Yes. Q. Which do you think is the best economy, to run with your throttle wide open or partly shut? A. Always have the throttle wide open on a governor engine. Q. At what temperature has iron the greatest tensile strength? A. About 600 degrees. Q. In what position on the shaft does the eccentric stand in relation to the crank? A. The throw of the eccentric should always be in advance of the crank pin. Q. About how many pounds of water are required to yield one horsepower with our best engines? A. From 25 to 30. Q. What is meant by atmospheric pressure? A. The weight of the atmosphere. Q. What is the weight of atmosphere at sea level? A. 14.7 pounds. Q. What is the coal consumption per hour per indicated horsepower? A. Varies from one and a half to seven pounds. Q. What is the consumption of coal per hour on a square foot of grate surface? A. From 10 to 12 pounds. Q. What is the water consumption in pounds per hour per indicated horsepower? A. From 25 to 60 pounds. Q. How many pounds of water can be evaporated with one pound of best soft coal? A. From 7 to 10 pounds. Q. How much steam will one cubic inch of water evaporate under atmospheric pressure? A. One cubic foot of steam (approximately). Q. What is the weight of a cubic foot of fresh water? A. Sixty-two and a half pounds. Q. What is the weight of a cubic foot of iron? A. 486.6 pounds. Q. What is the weight of a square foot of one-half inch boiler plate? A. 20 pounds. Q. How much wood equals one ton of soft coal for steam purposes? A. About 4,000 pounds of wood. Q. How long have you run engines? Q. Have you ever done your own firing? Q. What is the source of all power in the steam engine? A. The heat stored up in the coal. Q. How is the heat liberated from the coal? A. By burning it; that is, by combustion. Q. Of what does coal consist? A. Carbon, hydrogen, nitrogen, sulphur, oxygen and ash. Q. What are the relative proportions of these that enter into coal? A. There are different proportions in different specimens of coal, but the following shows the average per cent: Carbon, 80; hydrogen, 5; nitrogen, 1; sulphur, 2; oxygen, 7; ash, 5. Q. What must be mixed with coal before it will burn? A. Atmospheric air. Q. What is air composed of? A. It is composed of nitrogen and oxygen in the proportion of 77 of nitrogen to 23 of oxygen. Q. What parts of the air mix with what parts of the coal? A. The oxygen of the air mixes with the carbon and hydrogen of the coal. Q. How much air must mix with the coal? A. 150 cubic feet of air for every pound of coal. Q. How many pounds of air are required to burn one pound of carbon? A. Twelve. Q. How many pounds of air are required to burn one pound of hydrogen? A. Thirty-six. Q. Is hydrogen hotter than carbon? A. Yes, four and one-half times hotter. Q. What part of the coal gives out the most heat? A. The hydrogen does part for part, but as there is so much more of carbon than hydrogen in the coal we get the greatest amount of heat from carbon. Q. In how many different ways is heat transmitted? A. Three; by radiation, by conduction and by convection. Q. If the fire consisted of glowing fuel, show how the heat enters the water and forms steam? A. The heat from the glowing fuel passes by radiation through the air space above the fuel to the furnace crown. There it passes through the iron of the crown by conduction. There it warms the water resting on the crown, which then rises and parts with its heat to the colder water by conduction till the whole mass of water is heated. Then the heated water rises to the surface and parts with its steam, so a constant circulation of water is maintained by convection. Q. What does water consist of? A. Oxygen and hydrogen. Q. In what proportion? A. Eight of oxygen to one of hydrogen by weight. Q. What are the different kinds of heat? A. Latent heat, sensible heat and sometimes total heat. Q. What is meant by latent heat? A. Heat that does not affect the thermometer and which expands itself in changing the nature of a body, such as turning ice into water or water into steam. Q. Under what circumstances do bodies get latent heat? A. When they are passing from a solid state to a liquid or from a liquid to a gaseous state. Q. How can latent heat be recovered? A. By bringing the body back from a state of gas to a liquid or from that of a liquid to that of a solid. Q. What is meant by a thermal unit? A. The heat necessary to raise one pound of water at 39 degrees Fn. 1 degree Fahrenheit. Q. If the power is in coal, why should we use steam? A. Because steam has some properties which make it an invaluable agent for applying the energy of the heat to the engine. Q. What is steam? A. It is an invisible elastic gas generated from water by the application of heat. Q. What are its properties which make it so valuable to us? A. 1.--The ease with which we can condense it. 2.--Its great expansive power. 3.--The small space it occupies when condensed. Q. Why do you condense the steam? A. To form a vacuum and so destroy the back pressure that would otherwise be on the piston and thus get more useful work out of the steam. Q. What is vacuum? A. A space void of all pressure. Q. How do you maintain a vacuum? A. By the steam used being constantly condensed by the cold water or cold tubes, and the air pump as constantly clearing the condenser out. Q. Why does condensing the used steam form a vacuum? A. Because a cubic foot of steam, at atmospheric pressure, shrinks into about a cubic inch of water. Q. What do you understand by the term horse power? A. A horse power is equivalent to raising 33,000 pounds one foot per minute, or 550 pounds raised one foot per second. Q. How do you calculate the horse power of tubular or flue boilers? A. For tubular boilers, multiply the square of the diameter by length, and divide by four. For flue boilers, multiply the diameter by the length and divide by four; or, multiply area of grate surface in square feet by 1½. Q. What do you understand by lead on an engine’s valve? A. Lead on a valve is the admission of steam into the cylinder before the piston completes its stroke. Q. What is the clearance of an engine as the term is applied at the present time? A. Clearance is the space between the cylinder head and the piston head with the ports included. Q. What are considered the greatest improvements on the stationary engine in the last forty years? A. The governor, the Corliss valve gear and the triple compound expansion. Q. What is meant by triple expansion engine? A. A triple expansion engine has three cylinders using the steam expansively in each one. Q. What is a condenser as applied to an engine? A. The condenser is a part of the low pressure engine and is a receptacle into which the exhaust enters and is there condensed. Q. What are the principles which distinguish a high pressure from a low pressure engine? A. Where no condenser is used and the exhaust steam is open to the atmosphere. Q. About how much gain is there by using the condenser? A. 17 to 25 per cent where cost of water is not figured. Q. What do you understand by the use of steam expansively? A. Where steam admitted at a certain pressure is cut off and allowed to expand to a lower pressure. Q. How many inches of vacuum give the best results in a condensing engine? A. Usually considered 25. Q. What is meant by a horizontal tandem engine? A. One cylinder being behind the other with two pistons on same rod. Q. What is a Corliss valve gear? A. (_Describe the half moon or crab claw gear, or oval arm gear with dash pots._) Q. From what cause do belts have the power to drive shafting? A. By friction or cohesion. Q. What do you understand by lap? A. Outside lap is that portion of valve which extends beyond the ports when valve is placed on the center of travel, and inside lap is that portion of valve which projects over the ports on the inside or towards the middle of valve. Q. What is the use of lap? A. To give the engine compression. Q. Where is the dead center of an engine? A. The point where the crank and the piston rod are in the same right line. Q. What is the tensile strength of American boiler iron? A. 40,000 to 60,000 pounds per square inch. Q. What is very high tensile strength in boiler iron apt to go with? A. Lack of homogeneousness and lack of toughness. Q. What is the advantage of toughness in boiler plate? A. It stands irregular strains and sudden shocks better. Q. What are the principal defects found in boiler iron? A. Imperfect welding, brittleness, low ductility. Q. What are the advantages of steel as a material for boiler plates? A. Homogeneity, tensile strength, malleability, ductility and freedom from laminations and blisters. Q. What are the disadvantages of steel as a material for boiler plates? A. It requires greater skill in working than iron, and has, as bad qualities, brittleness, low ductility and flaws induced by the pressure of gas bubbles in the ingot. Q. When would you oil an engine? A. Before starting it and as often while running as necessary. Q. How do you find proper size of any stay bolts for a well made boiler? A. First, multiply the given steam pressure per square inch by the square of the distance between centers of stay bolts, and divide the product by 6,000, and call the answer “the quotient.” Second, divide “the quotient” by .7854, and extract the square root of the last quotient; the answer will give the required diameter of stay bolts at the bottom of thread. Q. In what position would you place an engine, to take up any slack motion of the reciprocating parts? A. Place engine in the position where the least wear takes place on the journals. That is, in taking up the wear of the crank-pin brasses, place the engine on either dead center, as, when running, there is but little wear upon the crank-pin at these points. If taking up the cross-head pin brasses--without disconnecting and swinging the rod--place the engine at half stroke, which is the extreme point of swing of the rod, there being the least wear on the brasses and cross-head pin in this position. Q. What benefits are derived by using flywheels on steam engines? A. The energy developed in the cylinder while the steam is doing its work is stored up in the flywheel, and given out by it while there is no work being done in the cylinder--that is, when the engine is passing the dead centers. This tends to keep the speed of the engine shaft steady. Q. Name several kinds of reducing motions, as used in indicator practice? A. The pantograph, the pendulum, the brumbo pulley, the reducing wheel. Q. How can an engineer tell from an indicator diagram whether the piston or valves are leaking? A. Leaky steam valves will cause the expansion curve to become convex; that is, it will not follow hyperbolic expansion, and will also show increased back pressure. But if the exhaust valves leak also, one may offset the other, and the indicator diagram would show no leak. A leaky piston can be detected by a rapid falling in the pressure on the expansion curve immediately after the point of cut-off. It will also show increased back pressure. A falling in pressure in the upper portion of the compression curve shows a leak in the exhaust valve. Q. What would be the best method of treating a badly scaled boiler, that was to be cleaned by a liberal use of compound? A. First open the boiler up and note where the loose scale, if any, has lodged. Wash out thoroughly and put in the required amount of compound. While the boiler is in service, open the blow-off valve for a few seconds, two or three times a day, to be assured that it does not become stopped up with scale. After running the boiler for a week, shut it down, and, when the pressure is down and the boiler cooled off, run the water out and take off the hand-hole plates. Note what effect the compound has had on the scale, and where the disengaged scale has lodged. Wash out thoroughly and use judgment as to whether it is advisable to use a less or greater quantity of compound, or to add a small quantity daily. Continue the washing out at short intervals, as many boilers have been burned by large quantities of scale dropping on the crown sheets and not being removed. Q. If a condenser was attached to a side-valve engine, that had been set to run non-condensing, what changes, if any, would be necessary? A. More lap would have to be added to the valve to cut off the steam at an earlier point of the stroke; if not, the initial pressure into the cylinder would be throttled down and the economy, to be gained from running condensing, lessened. Q. If you are carrying a vacuum equal to 27½ inches of mercury, what should the temperature of the water in the hot well be? A. 108 degrees Fahrenheit. Q. Define specific gravity. A. The specific gravity of a substance is the number which expresses the relation between the weights of equal volume of that substance, and distilled water of 60 degrees Fahrenheit. Q. Find the specific gravity of a body whose volume is 12 cubic inches, and which floats in water with 7 cubic inches immersed. A. When a body floats in water, it displaces a quantity of water equal to the weight of the floating body. Thus, if a body of 12 cubic inches in volume floats with 7 cubic inches immersed, 7 cubic inches of water must be equal in weight to 12 cubic inches of the substance and one cubic inch of water to twelve-sevenths cubic inches of the substance. As specific gravity equals weight of one volume of substance divided by weight of equal volume of water, then specific gravity of the substance in this case equals 1 divided by twelve-sevenths. USEFUL INFORMATION. To find circumference of a circle, multiply diameter by 3.1416. To find diameter of a circle, multiply circumference by .31831. To find area of a circle multiply square of diameter by .7854. To find area of a triangle, multiply base by one-half the perpendicular height. To find surface of a ball, multiply square of diameter by 3.1416. To find solidity of a sphere, multiply cube of diameter by .5236. To find side of an equal square, multiply diameter by .8862. To find cubic inches in a ball multiply cube of diameter by .5236. Doubling the diameter of a pipe increases its capacity four times. A gallon of water (U. S. standard) weighs 8 1-3 pounds and contains 231 cubic inches. A cubic foot of water contains 7½ gallons, 1728 cubic inches, and weighs 62½ pounds. To find the pressure in pounds per square inch of a column of water multiply the height of the column in feet by .434. Steam rising from water at its boiling point (212 degrees) has a pressure equal to the atmosphere (14.7 pounds to the square inch). A standard horse power: The evaporation of 30 lbs. of water per hour from a feed water temperature of 100 degrees F. into steam at 70 lbs. gauge pressure. To find capacity of tanks any size; given dimensions of a cylinder in inches, to find its capacity in U. S. gallons: Square the diameter, multiply by the length and by .0034. To ascertain heating surface in tubular boilers, multiply two-thirds of the circumference of boiler by length of boiler in inches and add to it the area of all the tubes. One-sixth of tensile strength of plate multiplied by thickness of plate and divided by one-half the diameter of boiler gives safe working pressure for tubular boilers. For marine boilers add 20 per cent for drilled holes. To find the horsepower of an engine, the following four factors must be considered: Mean effective or average pressure on the cylinder, length of stroke, diameter of cylinder, and number of revolutions per minute. Find the area of the piston in square inches by multiplying the diameter by 3.1416 and multiply the result by the steam pressure in pounds per square inch; multiply this product by twice the product of the length of the stroke in feet and the number of revolutions per minute; divide the result by 33,000, and the result will be the horsepower of the engine. (Theoretically a horsepower is a power that will raise 33,000 pounds one foot in one minute.) The power of fuel is measured theoretically from the following basis: If a pound weight fall 780 feet in a vacuum, it will generate heat enough to raise the temperature of one pound of water one degree. Conversely, power that will raise one pound of water one degree in temperature will raise a one pound weight 780 feet. The heat force required to turn a pound of water at 32 degrees into steam would lift a ton weight 400 feet high, or develop two-fifths of one horsepower for an hour. The best farm engine practically uses 35 pounds of water per horsepower per hour, showing that one pound of water would develop only one-thirty-fifth of a horsepower in an hour, or 7 1-7 per cent of the heat force liberated. The rest of the heat force is lost in various ways, as explained in the body of this book. The following[9] will assist in determining the amount of power supplied to an engine: Footnote 9: J. H. Maggard in “Rough and Tumble Engineering.” “For instance, a 1-inch belt of the standard grade with the proper tension, neither too tight or too loose, running at a maximum speed of 800 feet a minute will transmit one horsepower, running 1,600 feet two horsepower and 2,400 feet three horsepower. A 2-inch belt at the same speed, twice the power. “Now if you know the circumference of your flywheel, the number of revolutions your engine is making and the width of belt, you can figure very nearly the amount of power you can supply without slipping your belt. For instance, we will say your flywheel is 40 inches in diameter or 10.5 feet nearly in circumference and your engine was running 225 revolutions a minute, your belt would be traveling 225×10.5 feet = 2362.5 feet, or very nearly 2,400 feet, and if one inch of belt would transmit three horsepower running this speed, a 6-inch belt would transmit eighteen horsepower, a 7-inch belt twenty-one horsepower, an 8-inch belt twenty-four horsepower, and so on. With the above as a basis for figuring you can satisfy yourself as to the power you are furnishing. To get the best results a belt wants to sag slightly, as it hugs the pulley closer, and will last much longer.” KEYING PULLEYS.[10] A key must be of equal width its whole length and accurately fit the seats on shaft and in pulley. The thickness should vary enough to make the taper correspond with that of the seat in the pulley. The keys should be driven in tight enough to be safe against working loose. The hubs of most of the pulleys on the machine run against the boxes, and in keying these on, about 1-32 of an inch end play to the shaft should be allowed, because there is danger of the pulley rubbing so hard against the end of the box as to cause it to heat. A key that is too thin but otherwise fits all right can be made tight by putting a strip of tin between the key and the bottom of the seat in the pulley. _Drawing Keys._ If a part of the key stands outside of the hub, catch it with a pair of horseshoe pinchers and pry with them against the hub, at the same time hitting the hub with a hammer so as to drive pulley on. A key can sometimes be drawn by catching the end of it with a claw hammer and driving on the hub of pulley. If pulley is against box and key cut off flush with hub, take the shaft out and use a drift from the inside, or if seat is not long enough to make this possible, drive the pulley on until the key loosens. BABBITTING BOXES.[10] To babbitt any kind of a box, first chip out all of the old babbitt and clean the shaft and box thoroughly with benzine. This is necessary or gas will be formed from the grease when the hot metal is poured in and leave “blow holes.” In babbitting a _solid box_ cover the shaft with paper, draw it smooth and tight, and fasten the lapped ends with mucilage. If this is not done the shrinkage of the metal in cooling will make it fast on the shaft, so that it can’t be moved. If this happened it would be necessary to put the shaft and box together in the fire and melt the babbitt out or else break the box to get it off. Paper around the shaft will prevent this and if taken out when the babbitt has cooled the shaft will be found to be just tight enough to run well. Footnote 10: Courtesy J. I. Case Threshing Machine Co., from “Science of Successful Threshing.” Before pouring the box, block up the shaft until it is in line and in center of the box and put stiff putty around the shaft and against the ends of the box to keep the babbitt from running out. Be sure to leave air-holes at each end at the top, making a little funnel of putty around each. Also make a larger funnel around the pouring hole, or, if there is none, enlarge one of the air-holes at the end and pour in that. The metal should be heated until it is just hot enough to run freely and the fire should not be too far away. When ready to pour the box, don’t hesitate or stop, but pour continuously and rapidly until the metal appears at the air holes. The oil hole may be stopped with a wooden plug and if this plug extends through far enough to touch the shaft, it will leave a hole through the babbitt so that it will not be necessary to drill one. _A split box_ is babbitted in the same manner except that strips of cardboard or sheet-iron are placed between the two halves of the box and against the shaft to divide the babbitt. To let the babbitt run from the upper half to the lower, cut four or six V-shaped notches, a quarter of an inch deep, in the edges of the sheet-iron or cardboard that come against the shaft. Cover the shaft with paper and put cardboard liners between the box to allow for adjustment as it wears. Bolt the cap on securely before pouring. When the babbitt has cooled, break the box apart by driving a cold chisel between the two halves. Trim off the sharp edges of the babbitt and with a round-nose chisel cut oil grooves from the oil hole towards the ends of the box and on the slack side of the box or the one opposite to the direction in which the belt pulls. The ladle should hold six or eight pounds of metal. If much larger it is awkward to handle and if too small it will not keep the metal hot long enough to pour a good box. The cylinder boxes on the separator take from two to three pounds of metal each. If no putty is at hand, clay mixed to the proper consistency may be used. Use the best babbitt you can get for the cylinder boxes. If not sure of the quality, use ordinary zinc. It is not expensive and is generally satisfactory. MISCELLANEOUS. Lime may be taken out of an injector by soaking it over night in a mixture of one part of muriatic acid and ten parts soft water. If a larger proportion of acid is used it is likely to spoil the injector. A good blacking for boilers and smokestacks is asphaltum dissolved in turpentine. To polish brass, dissolve 5 cents’ worth of oxalic acid in a pint of water and use to clean the brass. When tarnish has been removed, dry and polish with chalk or whiting. It is said that iron or steel will not rust if it is placed for a few minutes in a warm solution of washing soda. Grease on the bottom of a boiler will stick there and prevent the water from conducting away the heat. When steel is thus covered with grease it will soon melt in a hot fire, causing a boiler to burst if the steel is poor, or warping it out of shape if the steel is good. Sulphate of lime in water, causing scale, may be counteracted and scale removed by using coal oil and sal soda. When water contains carbonate of lime, molasses will remove the scale. CODE OF WHISTLE SIGNALS. One short sound means to stop. Two short sounds means the engine is about to begin work. Three medium short sounds mean that the machine will soon need grain and grain haulers should hurry. One rather long sound followed by three short ones means the water is low and water hauler should hurry. A succession of short, quick whistles means distress or fire. WEIGHT PER BUSHEL OF GRAIN. The following table gives the number of pounds per bushel required by law or custom in the sale of grain in the several states: ====================+==+==+==+==+==+==+==+==+==+==+== \| \| \| \| \| \| \| \| \| S\| \| \| \| \| \| \| \| \| \| \| h\| \| \| \| \| \| \| \| \| \| \| e\| \| \| \| \| B\| \| \| \| \| \| l\| \| \| \| \| u\| \| \| \| \| \| l\| \| \| \| \| c\| \| \| \| \| \| e\| T\| \| B\| \| k\| C\| \| M\| \| \| d\| i\| \| a\| B\| w\| l\| \| i\| \| \| \| m\| W \| r\| e\| h\| o\| F\| l\| O\| \| C\| o\| h \| l\| a\| e\| v\| l\| l\| a\| R\| o\| t\| e \| e\| n\| a\| e\| a\| e\| t\| y\| r\| h\| a \| y\| s\| t\| r\| x\| t\| s\| e\| n\| y\| t \| .\| .\| .\| .\| .\| .\| .\| .\| .\| .\| . --------------------+--+--+--+--+--+--+--+--+--+--+-- Arkansas \|48\|60\|52\|60\|..\|..\|..\|56\|56\|45\|60 California \|50\|..\|40\|..\|..\|..\|32\|54\|52\|..\|60 Connecticut \|..\|..\|45\|..\|..\|..\|32\|56\|56\|..\|56 District of Columbia\|47\|62\|48\|60\|..\|..\|32\|56\|56\|45\|60 Georgia \|40\|..\|..\|60\|..\|..\|35\|56\|56\|45\|60 Illinois \|48\|60\|52\|60\|56\|45\|32\|56\|56\|..\|60 Indiana \|48\|60\|50\|60\|..\|..\|32\|56\|56\|45\|60 Iowa \|48\|60\|52\|60\|56\|48\|32\|56\|56\|45\|60 Kansas \|50\|60\|50\|..\|..\|..\|32\|56\|56\|45\|60 Kentucky \|48\|60\|52\|60\|56\|..\|32\|56\|56\|45\|60 Louisiana \|32\|..\|..\|..\|..\|..\|32\|..\|56\|..\|60 Maine \|48\|64\|48\|..\|..\|..\|30\|..\|56\|..\|60 Manitoba \|48\|..\|48\|60\|56\|34\|..\|56\|56\|..\|60 Maryland \|48\|64\|48\|..\|..\|..\|32\|56\|56\|45\|60 Massachusetts \|48\|48\|..\|..\|..\|..\|32\|56\|56\|..\|60 Michigan \|48\|..\|48\|60\|56\|..\|32\|56\|56\|45\|60 Minnesota \|48\|60\|42\|60\|..\|48\|32\|56\|56\|..\|60 Missouri \|48\|60\|52\|60\|56\|50\|32\|56\|56\|45\|60 Nebraska \|48\|60\|52\|60\|..\|..\|34\|56\|56\|45\|60 New York \|48\|62\|48\|60\|..\|..\|32\|56\|58\|44\|60 New Jersey \|48\|..\|50\|64\|..\|..\|30\|56\|56\|..\|60 New Hampshire \|..\|60\|..\|..\|..\|..\|30\|56\|56\|..\|60 North Carolina \|48\|..\|50\|64\|..\|..\|30\|56\|54\|..\|60 North Dakota \|48\|..\|42\|60\|56\|..\|32\|56\|56\|..\|60 Ohio \|48\|60\|50\|60\|..\|..\|32\|50\|56\|45\|60 Oklahoma \|48\|..\|42\|60\|56\|..\|32\|56\|56\|..\|60 Oregon \|46\|..\|42\|60\|..\|..\|36\|56\|56\|..\|60 Pennsylvania \|47\|..\|48\|62\|..\|..\|30\|56\|56\|..\|60 South Dakota \|48\|..\|52\|60\|56\|50\|32\|56\|56\|..\|60 South Carolina \|48\|60\|56\|60\|..\|..\|33\|56\|56\|..\|60 Vermont \|48\|64\|48\|..\|60\|..\|32\|56\|56\|42\|60 Virginia \|48\|60\|48\|64\|..\|..\|32\|56\|56\|45\|60 West Virginia \|48\|60\|52\|60\|..\|..\|32\|56\|56\|45\|60 Wisconsin \|48\|..\|48\|60\|..\|..\|32\|56\|56\|..\|60 --------------------+--+--+--+--+--+--+--+--+--+--+-- CHAPTER XVI. DIFFERENT MAKES OF TRACTION ENGINES. J. I. CASE TRACTION ENGINES. These engines are among the simplest and at the same time most substantial and durable traction engines on the market. They are built of the best materials throughout, and are one of the easiest engines for a novice to run. They are of the side crank type, with spring mounting. The engine is supported by a bracket bolted to the side of the boiler, and a pillow block bearing at the firebox end bolted to the side plate of the boiler. The valve is the improved Woolf, a single simple valve being used, worked by a single eccentric. The eccentric strap has an extended arm pivoted in a wooden block sliding in a guide. The direction of this guide can be so changed by the reverse lever as to vary the cut-off and easily reverse the engine when desired. The engine is built either with a simple cylinder or with a tandem compound cylinder. In the operation of the differential gear, the power is first transmitted to spur gear, containing cushion springs, from thence by the springs to a center ring and four bevel pinions which bear equally upon both bevel gears. The whole differential consequently will move together as but one wheel when engine is moving straight forward or backward; but when turning a corner the four pinions revolve in the bevel gears just in proportion to the sharpness of the curve. There is a friction clutch working on the inside of the flywheel by means of two friction shoes that can be adjusted as they wear. There is a feed water heater with three tubes in a watertight cylinder into which the exhaust steam is admitted. The three tubes have smaller pipes inside so that the feed water in passing through forms a thin cylindrical ring. [Illustration: J. I. CASE TRACTION ENGINE.] The traction wheels are driven from the rims. The front wheels have a square band on the center of the rim, to prevent slipping sidewise. The smokestack is cast iron in one piece. The firebox will burn wood, coal or straw, a fire brick arch being used for straw, making this fuel give a uniform heat. The boiler is of the simple locomotive type, with water leg around the firebox and numerous fire flues connecting the firebox with the smokestack in front. There is safety plug in crown sheet and the usual fittings. The water tank is under the platform. The steering wheel and band wheel are on right side of engine. An independent Marsh pump and injector are used. The Marsh pump is arranged to heat the feed water when exhaust heater cannot be used. The governor is the Waters, the safety valve the Kunkle. THE FRICK CO.’S TRACTION ENGINE. The most noticeable feature of this engine is that it has a frame mounted on the traction wheels entirely independent of the boiler, thus relieving the boiler of all strain. This is an undeniable advantage, since usually the strain on the boiler is great enough without forcing the boiler to carry the engine and gears. [Illustration: THE FRICK CO.’S TRACTION ENGINE.] The gearing to the traction wheels is simple and direct, and a patent elastic spring or cushion connection is used which avoids sudden strain and possible breakage of gears. Steel traction wheels and riveted spokes. Differential gear in main axle, with locking device when both traction wheels are required to pull out of a hole. The reverse gear is single eccentric, the eccentric turning on the shaft. It is well adapted to using steam expansively. The crown sheet is so arranged as not to be left bare of water in going up or down hills. Working parts are covered dust proof. Engine has self-oiling features and sight feed lubricator. Friction clutch in flywheel. Safety brake on main axle. Engineer’s platform mounted on springs and every part of engine requiring attention can be reached conveniently from platform. Crank is center type. Cross-head pump is used. Usual fittings. [Illustration: GAAR, SCOTT & CO.’S TRACTION ENGINE.] These engines are built with boiler of locomotive type for burning wood and coal, and of return flue type for burning straw. They are also built of three general types, “Corliss-pattern” frame, “Standard” and “Compound.” The engine is side crank, mounted on brackets attached to the sides of the boiler. The bedplate, cylinder and guides are bored at one operation and cannot get out of alignment. Cylinder has wide ports and free exhaust, and piston has self-setting rings. The genuine link reverse gear is used, as on locomotives, and it undoubtedly has many advantages over any other, including an easily adjustable variable cut-off by correct setting of reverse lever. The differential gear is heavy and effective. A patent steering attachment, with spiral roll, holds chains taut and gives positive motion. Friction clutch is mounted on engine shaft and connects with the hub of the pinion on this shaft. Rigid pinion is also provided. Cross-head pump and injector are used, and Pickering governor with improved spring speeder, permitting quick and easy change of speed; also Sawyer’s lever for testing safety. Steam passes direct from dome to cylinder, without loss from cooling or condensing. The steel water tank can be filled by a jet pump operated by steam. D. JUNE & CO.’S TRACTION ENGINE. This is one of the very few traction engines built with upright boiler, but it has been on the market many years and has been widely used with great success as a general road locomotive. The engine is mounted on the water tank. The weight of the boiler comes on the hind wheels, and makes this type of engine superior for pulling. It is claimed that it has no equal on the market as a puller. The upright type of boiler has the advantage that the crown sheet is never exposed and it is claimed flues will last longer than in horizontal type. It works equally well whether it stands level or not, an advantage that no other type has. This type gets up steam more quickly than any other--it is said, from cold water, in twenty minutes. The steam is superheated in a way to economize fuel and water. By being mounted on the tank, the engine does not get hot as it would if mounted on the boiler, and the corresponding straining of parts is avoided. A patent water spark arrester is used which is an absolute protection. [Illustration: D. JUNE & CO.’S TRACTION ENGINE.] The engine is geared to the traction by a chain, which can easily be repaired as the links wear. The friction clutch works inside flywheel. Engine has a new reversible eccentric, and differential gear, with usual fittings. NICHOLS & SHEPARD TRACTION ENGINE. The builders of this engine lay special stress upon the care with which the boiler and similar parts are constructed. The important seams are double riveted, and the flue sheet is half inch steel, drilled instead of punched for the flues, and fitted with seamless steel flues, all of the best steel. [Illustration: NICHOLS & SHEPARD TRACTION ENGINE.] The boiler is the direct flue locomotive type. The crown sheet slopes backward to allow it to be covered with water in descending hills. Boiler has round-bottom firebox. Axle passes around below the boiler, and springs are provided. The engine is mounted on a long heater, which is attached to the side of the boiler. The locomotive link reverse is used, with a plain slide valve. Cross-head pump and injector are used, and improved pop safety valve. Cylinder is jacketed, and cross-head guides are rigid with cylinder, so that perfect alignment is always secured. Engines are built to burn coal or wood. A straw burner is provided with firebrick arch. Compound engines are also built. THE HUBER TRACTION ENGINE. The Huber boiler is of the return flue type, and the gates are in the large central tube. This does away with the low-hanging firebox, and enables the engine to cross streams and straddle stumps as the low firebox type cannot do. The cylindrical shape of the boiler also adds considerably to its strength. The water tank is carried in front, and swings around so as to open the smoke box, so that repairs may be made on the fire tubes at this end easily in the open air. With water front return flue boilers the workman has to crawl through entire length of central flue. As there is no firebox, the boiler is mounted above the axle, not by bolting a plate to the side of the firebox. The boiler is made fast to the axle, which is mounted on wheels with spring cushion gear, the springs being placed in the wheel itself, between the two bearings of the wheel or the hub on trunnions, which form the spindle for the hub. The wheel revolves on the trunnion instead of on the axle, and there is no wear on the axle. The traction gear has a spring connection so that in starting a load there is little danger of breakage. The compensating gear is all spur. The intermediate gear has a ten-inch bearing, with an eccentric in the center for adjusting the gear above and below. There is a spring draw bar and elastic steering device. An improved friction clutch works on inside of flywheel. Engine has a special governor adapted to varying work over rough roads, etc. [Illustration: THE HUBER TRACTION ENGINE.] A single eccentric reverse gear is used, with arm and wood slide block (Woolf); and there is a variable exhaust, by which a strong draft may be quickly created by shutting off one of two exhaust nozzles. When both exhausts are open, back pressure is almost entirely relieved. The steam is carried in a pipe down through the middle of the central flue, so that superheating is secured, which it is claimed makes a saving of over 8 per cent in fuel and water. The stack is double walled with air space between the walls. A special straw-burning engine is constructed with a firebox extension in front, and straw passes over the end of a grate in such a way as to get perfect combustion. This make of engine is peculiarly adapted to burning straw successfully. A. W. STEVENS’ TRACTION ENGINE. This engine has locomotive pattern boiler, with sloping crown sheet, and especially high offset over firebox, doubling steam space that will give dry steam at all times. A large size steam pipe passes from dome in rear through boiler to engine in front, superheating steam and avoiding condensation from exposure. Grate is a rocking one, easily cleaned and requiring little attention, and firedoor is of a pattern that remains air-tight and need seldom be opened. The engine is mounted upon the boiler, arranged for rear gear traction attachment. Engine frame, cylinder, guides, etc., are cast in one solid piece. [Illustration: A. W. STEVENS’ TRACTION ENGINE.] It has a special patented single eccentric reverse, and Pickering horizontal governor. There is a friction clutch, Marsh steam pump, and injector. Other fittings are complete, and engine is well made throughout. AULTMAN-TAYLOR TRACTION ENGINE. The Aultman-Taylor Traction Engine is an exceptionally well made engine of the simplest type, and has been on the market over 25 years. There are two general types, the wood and coal burners with locomotive boilers, and return flue boiler style for burning straw. A compound engine is also made with the Woolf single valve gear. [Illustration: AULTMAN-TAYLOR TRACTION ENGINE.] A special feature of this engine is that the rear axle comes behind the firebox instead of between the firebox and the front wheels. This distributes the weight of the engine more evenly. The makers do not believe in springs for the rear axle, since they have a tendency to wear the gear convex or round, and really accomplish much less than they are supposed to. Another special point is the bevel traction gear. The engine is mounted on the boiler well toward the front, and the flywheel is near the stack (in the locomotive type). By bevel gears and a long shaft the power is conducted to the differential gear in connection with the rear wheels. The makers claim that lost motion can be taken up in a bevel gear much better than in a spur gear. Besides, the spur gear is noisy and not nearly so durable. Much less friction is claimed for this type of gear. The governor is the Pickering; cross-head pump is used, with U. S. injector; heater, and other fittings complete. A band friction clutch is used, said to be very durable. Diamond special spark arrester is used except in straw burners. The platform and front bolster are provided with springs. The makers especially recommend their compound engine, claiming a gain of about 25 per cent. The use of automatic band cutters and feeders, automatic weighers and baggers, and pneumatic stackers with threshing machine outfits make additional demands on an engine that is best met by the compound type. With large outfits, making large demands, the compound engine gives the required power without undue weight. AVERY TRACTION ENGINE. The Avery is an engine with a return flue boiler and full water front, and also is arranged with a firebox besides. There is no doubt that it effects the greatest economy of fuel possible, and is adaptable equally for wood, coal, or straw. The boiler is so built that a man may readily crawl through the large central flue and get at the front ends of the return tubes to repair them. [Illustration: AVERY TRACTION ENGINE.] The side gear is used with a crank disc instead of arm. The reverse is the Grime, a single eccentric with device for shifting for reverse. The friction clutch has unusually long shoes, working inside the flywheel, with ample clearance when lever is off. A specialty is made of extra wide traction wheels for soft country. The traction gear is of the spur variety. There is also a double speed device offered as an extra. The water tank is carried in front, and lubricator, steering wheel (on same side as band wheel for convenience in lining up with separator), reverse lever, friction clutch, etc., are all right at the hand of the engineer. The traction gear is of the spur variety, adjusted to be evenly distributed to both traction wheels through the compensating gear, and to get the best possible pull in case of need. For pulling qualities and economy of fuel, this engine is especially recommended. BUFFALO PITTS TRACTION ENGINE. The Buffalo Pitts Engine is built either single cylinder or double cylinder. The boiler is of the direct flue locomotive type, with full water bottom firebox. The straw burners are provided with a firebrick arch in the firebox. Boilers are fully jacketed. [Illustration: BUFFALO PITTS TRACTION ENGINE.] The single and double cylinder engines differ only in this one particular, the double cylinder having the advantage of never being on a dead center and starting with perfect smoothness and gently, seldom throwing off belt. The frame has bored guides, in same piece with cylinder, effecting perfect alignment. The compensating gear is of the bevel type, half shrouded and so close together that sand and grit are kept out. Three pinions are used, which it is claimed prevent rocking caused by two or four pinions. Cross-head has shoes unusually long and wide. The engine frame is of the box pattern, and is also used as a heater, feed water for either injector or steam pump passing through it. Valve is of the plain locomotive slide type. The friction clutch has hinged arms working into flywheel with but slight beveling on flywheel inner surface, and being susceptible of easy release. It is a specially patented device. The Woolf single eccentric reverse gear is used. Engine is fully provided with all modern fittings and appliances in addition to those mentioned. It was the only traction engine exhibited at Pan-American Exposition which won gold medal or highest award. It claims extra high grade of workmanship and durability. THE REEVES TRACTION ENGINES. These engines are made in two styles, simple double cylinder and cross compound. The double cylinder and cross compound style have been very successfully adapted to traction engine purposes with certain advantages that no other style of traction engine has. With two cylinders and two pistons placed side by side, with crank pins at right angles on the shaft, there can be no dead centers, at which an engine will be completely stuck. Then sudden starting is liable to throw off the main belt. With a double cylinder engine the starting is always gradual and easy, and never fails. The same is equally true of the cross compound, which has the advantage of using the steam expansively in the low pressure cylinder. In case of need the live steam may be introduced into the low pressure cylinder, enormously increasing the pulling power of the engine for an emergency, though the capacity of the boiler does not permit long use of both cylinders in this way. [Illustration: THE REEVES TRACTION ENGINE.] The engine is placed on top of the firebox portion of the boiler, and the weight is nicely balanced so that it comes on both sides alike. The gearing is attached to the axle and countershaft which extend across the engine. The compensating gear is strong and well covered from dirt. The gearing is the gear type, axle turning with the drivers. There is an independent pump; also injector, and all attachments. The band wheel being on the steering wheel or right side of the engine, makes it easy to line up to a threshing machine. Engine frame is of the Corliss pattern; boiler of locomotive type, and extra strongly built. THE RUMELY TRACTION ENGINE. The most striking peculiarity is that the engine is mounted on the boiler differently from most side crank traction engines, the cylinder being forward and the shaft at the rear. This brings the gearing nearer the traction wheels and reduces its weight and complication. [Illustration: THE RUMELY TRACTION ENGINE.] The boiler is of the round bottom firebox type, with dome in front and an ash pan in lower part of firebox, and is unusually well built and firmly riveted. The traction wheels are usually high, and the flywheel is between one wheel and the boiler. The engine frame is of the girder pattern, with overhanging cylinder attached to one end. The boiler is of the direct flue locomotive type, fitted for straw, wood, or coal. Beam axle of the engine is behind the firebox, and is a single solid steel shaft. Front axle is elliptical, and so stronger than any other type. A double cylinder engine is now being built as well as the single cylinder. The governor regulates the double cylinder engine more closely than single cylinder types, and in the Rumely is very close to the cut-off where a special simple reverse is used with the double cylinder engine. Engine is supplied with cross-head pump and injector, Arnold shifting eccentric reverse gear, friction clutch, and large cylindrical water tank on the side. It also has the usual engine and boiler fittings. PORT HURON TRACTION ENGINE. The Port Huron traction engine is of the direct flue locomotive type, built either simple or compound, and of medium weight and excellent proportions for general purpose use. The compound engine (tandem Woolf cylinders) is especially recommended and pushed as more economical than the simple cylinder engine. As live steam can be admitted to the low pressure cylinder, so turning the compound into a simple cylinder engine with two cylinders, enormous power can be obtained at a moment’s notice to help out at a difficult point. [Illustration: PORT HURON TRACTION ENGINE.] Two injectors are furnished with this engine, and the use of the injector is recommended, contrary to the general belief that a pump is more economical. The company contends that the long exhaust pipe causes more back pressure on the cylinder than would be represented by the saving of heat in the heater. However, a cross-head pump and special condensing heater will be furnished if desired. On the simple engine a piston valve is used, the seat of the valve completely surrounding it and the ports being circular openings, the result, it is claimed, being a balanced valve. The valve reverse gear is of the Woolf pattern, the engine frame of the girder type, Waters governor, with special patent speed changer, specially balanced crank disc, patent straw burner arrangement for straw burning engines, special patent spark extinguisher, special patent gear lock, and special patents on front axle, drive wheel and loco cab. The usual fittings are supplied. MINNEAPOLIS TRACTION ENGINE. The Minneapolis traction engine is built both simple and compound. All sizes and styles have the return flue boiler, for wood, coal or straw. Both axles extend entirely and straight under the boiler, giving complete support without strain. The cylinder, steam chest and guides form one piece, and are mounted above a heater, secured firmly to the boiler; valve single simple D pattern. Special throttle of the butterfly pattern, large crank pin turned by special device after it is driven in, so insuring perfect adjustment; special patent exhaust nozzle made adjustable and so as always to throw steam in center of stack; friction clutch with three adjustable shoes. Boiler is supplied with a superheater pipe. Woolf valve and reverse gear. Special heavy brass boxes and stuffing-boxes. Sight feed lubricator and needle feed oiler; Gardner spring governor. Complete with usual fittings. This is a simply constructed but very well made engine. [Illustration: MINNEAPOLIS TRACTION ENGINE.] INDEX. PAGE A Ash pit, 70 Attachments for traction engine, 52 Automatic cut-off engines, 137 B Babbitt boxes, how to, 189 Blast devices, 30 Blow-off devices, 30 Boiler and engine, test questions, 52 Boiler, attachments, 20 Boiler, heating surface of, 132 Boiler, how to manage, 56 Boiler, locomotive, 13 Boiler, questions, and answers, 95 Boiler, return flue, 15 Boiler, starting a, 57 Boiler, vertical, 17 Boiler, water for, 62 Boilers, 11 Boilers, how to fill with water, 24 Boilers, terms connected with, 17 Boss, 43 Box, a hot, 87 Boxes, how to babbitt, 189 Bridges, how to cross safely, 93 Buying an engine, 7 C Clearance, 35 Clearance and lead, 134 Compound and cross-compound engines, 141 Compound engines, 124 Condensation and expansion, 134 Condenser, 35 Condensing engines, 140 Connecting rod, 34 Corliss engines, 138 Crank, 34, 41, 42 Cross-head, 33 Cushion, 35 Cylinder cocks, 50 Cylinder cocks, how to use, 83 Cylinder head, 33 Cylinder lubricators, 45 D Differential gear, 46 Double eccentric, how to set valve, 82 E Eccentric, 36 Eccentric rod, 36 Eccentric, slipping of, 83 Economy in running farm engine, 116, 130 Engine and boiler, test questions, 52 Engine, compound, 124 Engines, different types of, 137 Engine, how to manage, 77 Engine, simple, 32 Exhaust chamber, 35 Exhaust, the, 135 Exhaust nozzle, 35 Expansion and condensation, 134 Expansive power of steam, how to use, 122 F Farm, engine, economy in running, 116, 130 Fire, starting, 70 Firing, economical, 67 Firing with coal, 68 Firing with straw, 69 Firing with wood, 69 Fly-wheel, 44 Friction, 126 Friction clutch, 47, 88 Fuel and grate surface, 130 Fusible plug, 48, 72 G Gas and gasoline engines, 143 Gas engines compared with steam, 144 Gasoline engines, description of, 146 Gasoline engines, how to operate, 150 Gasoline engines, what to do when they don’t work, 153 Gauge, water, 20 Gauge, steam, 22 Governors, 40 Grain, weight per bushel, 192 Grate surface, 130 H Heater, 67 Heating surface of a boiler, 132 High speed engines, 139 Hills, how to pass with engine, 94 Hole, how to get out of, 92 Hot box, a, 87 How energy is lost, 119 How heat is distributed, 120 Indicator, steam, 50 Injectors, 28-66 J Journals, 41, 44 K Key, gib, and strap, 42 Knock, what makes an engine, 79 L Lap of a valve, 35 Lead, 35, 80 Lead and clearance, 134 Leaks, 136 Leaky flues, 73 License, questions asked applicants for, 173 Link gear, 37 Lubrication, 85 Lubricators, 44 M Meyer valve gear, 40 N Non-condensing engines, 140 P Pillow blocks, 44 Piston, 33 Ports, 34 Practical points of economy, 130 Pulleys, how to key, 189 Pumps, boiler, 25, 63 Q Questions and answers, 95, 173, 104 Questions and answers, the boiler, 95 Questions and answers, the engine, 104 Questions, test, on engine and boiler, 52 R Reversing gear, 37 Road, how to handle traction engine on the, 91 S Safety valves, 23 Sand patches, how to get over with engine, 93 Setting a valve, 35, 81 Shaft, 41 Smoke, 71 Spark arresters, 31 Sparks, 72 Stationary engines, 137 Steam-chest, 34 Steam cylinder, 33 Steam, how to use expansive power of, 122 Steam, properties of, 121 Steam valve, 34 Stuffing box, 35, 50 T Threshing machines, how to run, 158 Attachments, 167 Balancing a cylinder, 170 Belting, 167 Concaves, 162 Conveyor extension, 164 Covering pulleys, 171 Cylinder, 161 Fan, 163 How to feed, 169 Self-feeder, 165 Separator, how to set, 160 Separator, care of, 171 Sieves, 164 Straw rack, 163 Tailings elevator, 165 Waste, 169 Wind stacker, 166 Theory of steam power, 116 Throttling engines, 137 Throttle, 34 Throw of an eccentric, 36 Traction engines, different makes, 193 Traction, engine, how, to handle on the road, 91 Traction, engine, how, to manage, 77 V Valve gear, 36 Valve, how to set simple, 81 Valve seat, 34 Valve, setting, 35 Valve stem, 35 Valve, steam, 34 W Whistle signals, code of, 191 Woolf reversing gear, 39 Y Young engineers, points for, 95, 104, 110 “ANNOUNCEMENT” =A NEW WORK= =UP-TO-DATE=, WILL BE PUBLISHED March 15th, 1903. A book every carpenter and builder, machinist, mechanic and apprentice will want. The life work of that well-known writer, Mr. Fred T. Hodgson. “PRACTICAL USES OF THE STEEL SQUARE” A Modern Treatise by Fred T. Hodgson. An exhaustive work including a brief history of the Square; a description of many of the Squares that are now, and have been in the market, including some very ingenious devices for laying out Bevels for Rafters, Braces and other inclined work; also chapters on the Square as a calculating machine, showing how to measure Solids, Surfaces and Distances--very useful to builders and estimators. Chapters on roofing and how to form them by the aid of the Square; Octagon, Hexagon, Hip and other Roofs are shown and explained, and the manner of getting the rafters and jacks given; Chapters on heavy timber framing, showing how the Square is used for laying out Mortises, Tenons, Shoulders, Inclined Work, Angle Corners and similar work. The work abounds with hundreds of fine illustrations and explanatory diagrams, which will prove a perfect mine of instruction for the mechanic, young or old. Two large volumes, bound in fine cloth, printed on a superior quality of paper from new large type. Each copy bears the Union Label, being made entirely by Union labor. PRICE, 2 Vols, in a Box, Cloth Binding $2.00 PRICE, 2 Vols, in a Box, Half-morocco Leather Binding 3.00 =PUBLISHERS’ NOTE=--We wish to state this work is entirely new and must not be mistaken for Mr. Hodgson’s former works on the “Steel Square,” which were published some twenty years ago. Be sure and ask for “Practical Uses of the Steel Square,” by Fred T. Hodgson, which bears the imprint of Send for descriptive circulars. =FREDERICK J. DRAKE & CO., Publishers= of Hodgson’s “Modern Carpentry,” “Common-Sense Handrailing,” etc. _Common-Sense Handrailings and How to Build Them_ By FRED T. HODGSON _ILLUSTRATED_ This new volume contains three distinct treatises on the subject, each of which is complete in itself. The system of forming the lines for obtaining the various curves, wreaths, ramps and face moulds for handrails are the simplest in use and those employed by the most successful handrailers. Mr. Hodgson has placed this unusually intricate subject before his readers in a very plain and easily understood manner, and any workman having a fair knowledge of “lines” and who can construct an ordinary straight stairway can readily grasp the whole system of “handrailing” after a small study of this work. The building of stairs and properly making and placing over them a graceful handrail and suitable balusters and newel posts is one of the greatest achievements of the joiner’s art and skill, yet it is an art that is the least understood of any of the constructive processes the carpenter or joiner is called upon to accomplish. In but very few of the plans made by an architect are the stairs properly laid down or divided off; indeed, most of the stairs as laid out and planned by the architect, are impossible ones owing to the fact that the circumstances that govern the formation of the rail, are either not understood, or not noticed by the designer, and the expert handrailer often finds it difficult to conform the stairs and rail to the plan. Generally, however, he gets so close to it that the character or the design is seldom changed. The stairs are the great feature of a building as they are the first object that meets the visitor and claims his attention, and it is essential, therefore, that the stair and its adjuncts should have a neat and graceful appearance, and this can only be accomplished by having the rail properly made and set up. This little book gives such instructions in the art of handrailing as will enable the young workman to build a rail so that it will assume a handsome appearance when set in place. There are eleven distinct styles of stairs shown, but the same principle that governs the making of the simplest rail, governs the construction of the most difficult, so, once having mastered the simple problems in this system, progress in the art will become easy, and a little study and practice will enable the workman to construct a rail for the most tortuous stairway. The book is copiously illustrated with nearly one hundred working diagrams together with full descriptive text. _12mo CLOTH, PRICE, $1.00_ FREDERICK J. DRAKE 6 CO., Publishers 211-213 East Madison St., CHICAGO Modern Carpentry A PRACTICAL MANUAL FOR CARPENTERS AND WOOD WORKERS GENERALLY By Fred T. Hodgson, Architect, Editor of the National Builder, Practical Carpentry, Steel Square and Its Uses, etc., etc. A new, complete guide, containing =hundreds of quick methods= for performing work in =carpentry, joining and general wood-work=. Like all of Mr. Hodgson’s works, it is written in a simple, every-day style, and does not bewilder the working-man with long mathematical formulas or abstract theories. The illustrations, of which there are many, are explanatory, so that any one who can read plain English will be able to understand them easily and to follow the work in hand without difficulty. The book contains methods of =laying roofs=, =rafters=, =stairs=, =floors=, =hoppers=, =bevels=, =joining mouldings=, =mitering=, =coping=, =plain hand-railing=, =circular work=, =splayed work=, and many other things the carpenter wants to know to help him in his every day vocation. It is the =most complete= and =very latest= work published, being =thorough=, =practical= and =reliable=. One which no carpenter can afford to be without. The work is printed from new, large type plates on a superior quality of cream wove paper, durably bound in English cloth. Price $1.00 FREDERICK J. DRAKE & CO. 211-213 E. Madison St., Chicago. Scientific Horse, Mule _and_ Ox Shoeing By J. G. Holmstrom, Author of Modern Blacksmithing =A standard treatise=, adapted to the demand of =Veterinarians=, =Farriers= and the =Amateur Horseshoer=. Illustrated. The book is concisely written; no long articles over the experiments of others, but gives the best methods known up to date. Although there are principles laid down in the book that will stand so long as the horse is a horse, the author does not lay any claim to infalibility or perfection; he has simply laid a foundation upon which the ironer of horses’ feet may build and develop a perfect structure. Among some of the valuable contents are:-- Anatomy of the Foot. The Shoe and How to Make it. Right and Wrong Filling. How to Nail the Shoe. How to Fit and Recalk Old Shoes. Interfering. Preparing the Foot for Shoeing. Shoeing a Trotter. Mule Shoeing. Ox Shoeing. Diseases of the Horse. Hot and Cold Fitting. How to Shoe Vicious Horses. Kneesprung. Stringhalt. Contraction. Sand Cracks, etc., etc. Many of the fine illustrations used are reproduced by permission from books issued by the U. S. Department of Agriculture. Large 12mo, Cloth, with Special Cover Design, =$1.00= Sold by Booksellers generally, or sent postpaid upon receipt of price. FREDERICK J. DRAKE & CO., Publisher. 211-213 East Madison St., CHICAGO ALL TECHNICAL TERMS AVOIDED Practical Telephone Hand Book and Guide to Telephonic Exchange HOW TO CONSTRUCT AND MAINTAIN TELEPHONE LINES By T. S. BALDWIN, M. A. Illustrated. Containing chapters on “The Use of the Telephone, Series and Bridging phones, Line Construction, Materials to be used, Locating and Correction of Faults in Instruments and Lines.” This is the best book ever published on Farm Telephones and has been the sensation of the past year in telephone circles. It is the only book ever issued which treats the subject exhaustively and comprehensively. It is of inestimable value to promoters of rural party lines because it contains all of the arguments that are necessary to show the advantages of rural party lines. It also tells how such lines should be constructed and cared for. The great growth of the telephone industry during the past few years, and in response to the demand for a comprehensive book, giving a clear, terse idea of the different principles governing the construction, installation, care and management of the various telephones and their appliances, the Practical Telephone Hand Book has been compiled. It is written in a most clear and careful style and aims to give a complete review of the subject of telephony. No expense has been spared in gathering valuable information, and it has been the aim of the author to make this treatise the most complete elementary book ever written on this subject for all persons interested in this great achievement of modern science. The text is profusely illustrated by cuts of commercial apparatus and carefully prepared diagrams of circuits. No diagram is given without a full explanation. The apparatus and methods used in making all the tests required in commercial telephone work, including the exchange, are fully treated. 12 Mo. Cloth, fully illustrated, price =$1.25= BOOKKEEPING SELF-TAUGHT _By PHILLIP C. GOODWIN_ Few, if any of the technical works, which purport to be self-instructing have justified the claims made for them, and invariably the student either becomes discouraged and abandons his purpose and aim, or he is compelled to enlist the offices of a professional teacher, which in the great majority of instances is impracticable when considered in relation to the demands upon time and the condition of life to which the great busy public is subjected. Mr. Goodwin’s treatise on Bookkeeping is an entirely new departure from all former methods of self-instruction and one which can be studied systematically and alone by the student with quick and permanent results, or taken up in leisure moments with an absolute certainty of acquiring the science in a very short time and with little effort. The book is both a marvel of skill and simplicity. Every feature and every detail leading to the climax of scientific perfection are so thoroughly complete in this logical procedure and the analysis so thorough and deftly made that the self-teaching student is led by almost imperceptible, but sure and certain steps to the basic principles of the science, which the author in a most comprehensive and lucid style lays bare to intelligence of, even the most mediocre order. The work is the most masterly exposition of the scientific principles of Bookkeeping and their practical application which has ever appeared in the English language, and it should be in the hands of every school boy or girl, every clerk, farmer, teacher and business or professional man; for a knowledge of Bookkeeping, even though it may not be followed as a profession, is a necessity felt by every person in business life and a recognized prime factor of business success. In addition to a very simple yet elaborate explanation in detail of the systems of both single and double entry Bookkeeping, beginning with the initial transactions and leading the student along to the culminating exhibit of the balance sheet, the work contains a glossary of all the commercial terms employed in the business world, together with accounts in illustration, exercises for practice and one set of books completely written up. 12mo Cloth. Price $1.00. Sent postpaid to any address upon receipt of price. Frederick J. Drake & Co., Publishers 211-213 EAST MADISON ST., CHICAGO Transcriber’s Notes. Italic text is denoted by _underscores_ and bold text by =equals signs=. Variant spelling, punctuation, and inconsistent hyphenation have been preserved as printed; simple typographical errors have been corrected. The following list notes the changes made or shows the changed text below the original text. Page 21: They open directly ut They open directly out Page 52: (1 is left in place.) [added closing parenthesis] Page 52: 15 ft. lin. Suction Hose 15 ft. 1 in. Suction Hose Page 55: used for rest of engine? used for rest of the engine? Page 59: imperfect team gauge imperfect steam gauge Page 59: tightning up a box there tightening up a box there Page 96: Blown off more is only a waste of heat Blowing off more is only a waste of heat Page 117: long separated overs long separated lovers Page 130: should have a great surface should have a grate surface Advertisements: Special Cover Design, $1.00 [added decimal point] Advertisements: Few, if any of of the technical works Few, if any of the technical works	78,068	common-pile/project_gutenberg_filtered	43867	project gutenberg	project_gutenberg-dolma-0007.json.gz:1275	https://www.gutenberg.org/files/43867/43867-0.txt
G9YqSqvdfrogKoLJ	US History II	57 Video: Gilded Age Politics This video teaches you about the Gilded Age and its politics. What, you may ask, is the Gilded Age? The term comes from a book by Mark Twain and Charles Dudley Warner titled, “The Gilded Age.” You may see a pattern emerging here. It started in the 1870s and continued on until the turn of the 20th century. The era is called Gilded because of the massive inequality that existed in the United States. Gilded Age politics were marked by a number of phenomenons, most of them having to do with corruption. On the local and state level, political machines wielded enormous power. This video gets into details about the most famous political machine, Tammany Hall. Tammany Hall ran New York City for a long, long time, notably under Boss Tweed. Graft, kickbacks, and voter fraud were rampant, but not just at the local level. Ulysses S. Grant ran one of the most scandalous presidential administrations in U.S. history, and you will hear about two of the best-known scandals, the Credit Mobilier scandal and the Whiskey Ring. There were a few attempts at reform during this time, notably the Civil Service Act of 1883 and the Sherman Anti-trust act of 1890. This video will also get into the Grange Movement of the western farmers, and the Populist Party that arose from that movement. The Populists, who threw in their lot with William Jennings Bryan, never managed to get it together and win a presidency, and they faded after 1896.	330	common-pile/pressbooks_filtered	https://library.achievingthedream.org/pimaushistory2/chapter/video-gilded-age-politics/	pressbooks	pressbooks-0000.json.gz:57426	https://library.achievingthedream.org/pimaushistory2/chapter/video-gilded-age-politics/

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